SPECIFICATION
POLYAMIDE RESIN COMPOSITION AND MOLDED ARTICLE COMPRISING
THE SAME
5
Field of the Invention
[0001] The present invention relates to a polyamide resin composition having
excellent mechanical properties or electrical insulating properties as well as excellent
thermal conduction properties and a molded article comprising the same.
10
Background Art
[0002] When graphite is incorporated into a thermoplastic resin, the thermal
conduction properties of the resin are improved according to the amount of the
graphite incorporated. In the thermoplastic resin having incorporated thereinto an
15 increased amount of graphite which is not melted in melt-kneading, the proportion of
the thermoplastic resin which is melted in melt-kneading is reduced, and therefore it is
difficult to maintain the high productivity of the thermoplastic resin in the meltkneading
using a single-screw or twin-screw extruder. Patent document 1 discloses
that kneading is performed in a state such that the head portion of an extruder is
20 opened. However, this patent document has no disclosure of a cooling apparatus,
such as a water bath, for efficiently removing heat from the resultant pellets in a flake
form, and there is a fear that the pellets stick together, and such kneading is not
preferred fiom the viewpoint of the molding processability.
[0003] The thermoplastic resin having graphite solely incorporated thereinto
25 exhibits unsatisfactory physical properties, such as a strength. Patent document 2
has a description showing that, by incorporating into a thermoplastic resin specific
amounts of graphite and carbon fibers having a thermal conductivity of 100 WimK or
more, the resin is improved in flexural strength and thermal conduction properties.
However, there is no disclosure of PAN carbon fibers generally used, which have a
30 thermal conductivity of about 10 W/mK and which are obtained by carbonizing
polyacrylonitrile fibers.
[0004] Polyamide resins, such as polyamide 6 and polyamide 66, have excellent
properties and can be easily melt-molded, and therefore are widely used as generalpurpose
engineering plastics. Reference documents 3 and 4 disclose that, by
35 incorporating magnesium oxide into the polyamide resin, the resin is improved in
thema! ccnduction properties,
[0005] On the other hand, as the increase in density and the miniaturization of an
electronic device progress, the amount of the polyamide resin used per part for
electronic device is reduced, and hence the effect of the properties of the polyamide
resin used on the performance of the part for electronic device is becoming large. In
5 accordance with this, there are increasing demands of the improvement of the
properties of the polyamide resin. Especially, there are increasing demands of
prevention of the lowering of electrical insulating properties of the polyamide resin,
which strongly affects the performance of the part for electronic device, under hightemperature
and high-humidity conditions (after a high-temperature and high-
10 humidity treatment), which are presumed to be, for example, under conditions in the
summer in Japan.
[0006] When magnesium oxide is incorporated into a thermoplastic resin, the
thermal conduction properties of the resin are improved according to the amount of
the magnesium oxide incorporated. In the thermoplastic resin having incorporated
15 thereinto an increased amount of magnesium oxide which is not melted in meltkneading,
the proportion of the thermoplastic resin which is melted in melt-kneading
is reduced, and therefore it is difficult to maintain the high productivity of the
thermoplastic resin in the melt-kneading using a single-screw or twin-screw extruder.
As a method of stably filling a resin with an increased amount of a conductive filler,
20 patent document 1 discloses that kneading is performed in a state such that the head
portion of an extruder is opened. However, there is no disclosure of a method of
stably filling a resin with an increased amount of a conductive filler without opening
the head portion of the extruder.
[0007] Further, patent document 5 discloses a method for improving the
25 moldability, appearance, and thermal conduction properties by incorporating
magnesium oxide having a specific particle size in a specific amount. However, in
the resultant molded article, the thermal conductivity varies depending on the location
of measurement, and there is no disclosure that a molded article exhibiting a uniform
thermal conductivity irrespective of location of measurement is stably obtained.
3 0
Prior Art References
Patent documents
[0008]
Patent document 1 : Japanese Unexamined Patent Publication No. Hei 8- 1663
35 Patent document 2: Japanese Unexamined Patent Publication No. 2003-4908 1
Patant document 3 : Japanese Unexamined Patent Publication No. Hei 1-21 3356
i Patent document 4: Japanese Unexamined Patent Publication No. Hei 3-79666
Patent document 5: Japanese Unexamined Patent Publication No. Hei 3-8 13 66
Disclosure of the Invention
5 Problems to be Solved by the Invention
[0009] An object of the present invention is to provide a polyamide resin
composition having excellent mechanical properties or electrical insulating properties
as well as excellent thermal conduction properties and a molded article comprising the
same.
10 Another object of the present invention is to provide a polyamide resin
composition which is advantageous not only in that the composition can achieve both
high thenpal conduction properties and high mechanical properties without using
carbon fibers having a thermal conductivity of 100 W/mK or more, but also in that the
polyamide resin composition with excellent productivity.
15 [0010] Still another object of the present invention is to provide a polyamide resin
composition which is prevented fiom lowering in electrical insulating properties after
a high-temperature and high-humidity treatment, and which exhibits excellent thermal
conduction properties.
A further task of the present invention is to provide a polyamide resin
20 composition advantageous in that there can be obtained a molded article which can be
stably produced by a general kneader without opening the head portion of the extruder
(kneader), and which exhibits uniform thermal conduction properties.
Means to Solve the Problems
[0011] The above-mentioned problems are solved by the present invention shown
below.
1. A polyamide resin composition comprising a polyamide resin (A) and a
property imparting component, the composition being:
(1) a polyamide resin composition which comprises, relative to 100 parts by
volume of the polyamide resin (A), as the property imparting component, 50 to less
than 100 parts by volume of flake graphite (B), 5 to 40 parts by volume of carbon
fibers (C), and 0.1 to 5 parts by volume of a polyhydric alcohol @);
(2) a polyamide resin composition which comprises the polyamide resin (A)
which is a polyamide resin (Al) comprising dicarboxylic acid units (x) and diarnine
units (y) as constitutional units, and the property imparting component which is at
least one member selected h m the group consisting of a metal oxide (B!), a nitrogen . .
compound (B2), and a silicon compound (B3), wherein the dicarboxylic acid units (x)
of the polyamide resin (Al) are oxalic acid in an amount of 70 mol% or more, based
on the total dicarboxylic acid units of the polyamide resin (Al); or
(3) a polyamide resin composition which comprises the polyamide resin (A)
5 and metal oxide particles (BB) as the property imparting component, wherein the
metal oxide particles @B) contain those having a particle size of 70 pm or more in an
amount of 10 to 50% by mass and those having a particle size of 20 p or less in an
amount of 1 to 50% by mass, based on the total mass of the metal oxide particles,
wherein the metal oxide particles (BB) are contained in an amount of 70 to 85% by
10 mass, based on the mass of the polyamide resin composition.
2. The polyamide resin composition according to item 1 above, which
comprises, relative to 100 parts by volume of the polyamide resin (A), 50 to less than
100 parts by volume of the flake graphite (B), 5 to less than 40 parts by volume of the
carbon fibers (C), and 0.1 to 5 parts by volume of the polyhydric alcohol @);
15 3. The polyamide resin composition according to item 2 above, wherein the
polyhydric alcohol @) is a polyhydric alcohol having a melting temperature of 150 to
280°C;
4. The polyamide resin composition according to item 2 or 3 above, which
is obtainable by melt-kneading;
20 5. The polyamide resin composition according to item 1 above, which
comprises the polyamide resin (Al) comprising dicarboxylic acid units (x) and
diamine units (y) as constitutional units, and at least one member selected from the
group consisting of a metal oxide @I), a nitrogen compound (B2), and a silicon
compound (B3), wherein the dicarboxylic acid units (x) of the polyamide resin (Al)
25 are oxalic acid in an amount of 70 mol% or more, based on the total dicarboxylic acid
units of the polyamide resin (Al);
6. The polyamide resin composition according to item 5 above, wherein the
metal oxide (Bl) is magnesium oxide;
7. The polyamide resin composition according to item 5 or 6 above, which
30 is for use in an electrical insulating part; and
8. The polyamide resin composition according to item 1 above, which
comprises the polyamide resin (A) and the metal oxide particles (BB), wherein the
metal oxide particles (BB) contain those having a particle size of 70 pm or more in an
amount of 10 to 50% by mass and those having a particle size of 20 pm or less in an
35 amount of 1 to 50% by mass, based on the total mass of the metal oxide particles,
- wherein themetal oxide partides (BB) are contained in-an amount of 70 to 85% by . --
mass, based on the mass of the polyarnide resin composition;
9. The polyamide resin composition according to item 8 above, which
m e r comprises the polyhydric aIcohol (D) in an amount of 0.1 to 5% by mass,
based on the mass of the polyamide resin composition;
5 10. The polyamide resin composition according to item 8 or 9 above,
wherein the metal oxide particles (BB) are magnesium oxide;
11. A molded article comprising the polyamide resin composition according
to any one of items 1 to 10 above.
10 Effect of the Invention
[0012] By the present inventions 1 to 11, there can be provided a polyamide resin
composition which is advantageous in that a molded article having excellent
mechanical properties or electrical insulating properties as well as excellent thermal
conduction properties can be obtained.
15 [0013] By the present inventions 2 to 4 and 1 1, further, there can be provided a
polyamide resin composition which is advantageous in that a molded article having
both excellent thermal conduction properties and excellent mechanical properties can
be obtained without using carbon fibers having a thermal conductivity of 100 W/mK
or more, and there can be provided a method which can stably pelletize the polyamide
20 resin composition by a general twin-screw extruder.
[0014] By the present inventions 5 to 7 and 11, further, there can be provided a
polyamide resin composition which is advantageous in that a molded article having
excellent electrical insulating properties even after a high-temperature and highhumidity
treatment and having both excellent thermal conduction properties and
25 excellent mechanical properties can be obtained. The polyamide resin composition
has especially excellent electrical insulating properties after a high-temperature and
high-humidity treatment, and therefore can be preferably used as an electrical
insulating material in an electrical insulating part.
[0015] By the present inventions 8 to 11, further, there can be provided a
30 polyamide resin composition which is advantageous in that there can be obtained a
molded article which can be stably produced by a general kneader without opening the
head portion of the kneader, and which exhibits uniform thermal conduction
properties.
35 BRJEF DESCRIPTION OF THE DRAWING
[0015] . . - - - - -. -- .. ' .. .
pig. 11 Fig. 1 is a view showing locations of measurement of thermal conductivity for
evaluating the thermal conduction properties.
BEST MODE FOR CARRYING OUT 'ITE INVENTION
[0017] The present invention is directed to a polyamide resin composition
comprising polyamide resin (A) and a property imparting component, wherein the
composition is:
(1) a polyamide resin composition which comprises, relative to 100 parts by
volume of polyamide resin (A), as the property imparting component, 50 to less than
100 parts by volume of flake graphite (B), 5 to 40 parts by volume of carbon fibers
(C), and 0.1 to 5 parts by volume of polyhydric alcohol @);
(2) a polyamide resin composition which comprises polyamide resin (A)
which is polyamide resin (Al) comprising dicarboxylic acid units (x) and diamine
units (y) as constitutional units, and the property imparting component which is at
least one member selected from the group consisting of metal oxide (Bl), nitrogen
compound (B2), and silicon compound (B3), wherein dicarboxylic acid units (x) of
polyamide resin (Al) are oxalic acid in im amount of 70 mol% or more, based on the
total mole of the dicarboxylic acid units of polyamide resin (Al); or
(3) a polyamide resin composition which comprises polyamide resin (A) and
metal oxide particles (BB) as the property imparting component, wherein metal oxide
particles (BB) contain those having a particle size of 70 pm or more in an amount of
10 to 50% by mass and those having a particle size of 20 pm or less in an amount of 1
to 50% by mass, based on the total mass of the metal oxide particles, wherein metal
oxide particles (BB) are contained in an amount of 70 to 85% by mass, based on the
mass of the polyamide resin composition.
[OO 181 [Polyamide resin composition A]
The present invention can be polyamide resin composition A which
comprises, relative to 100 parts by volume of polyamide resin (A), 50 to less than 100
parts by volume of flake graphite (B), 5 to 40 parts by volume of carbon fibers (C),
and 0.1 to 5 parts by volume of polyhydric alcohol (D).
The part(s) by volume used in the present invention is determined as follows.
Volumes of polyam..de resin (A), flake graphite (B), carbon fibers (C), and polyhydric
alcohol @) are individually determined from the respective masses and the respective
specific gravities under atmospheric pressure (1 atrn.) at 25OC, and, relative to 100
parts by volume of polyamide resin (A), part(s) by volume of each of flake graphite
(B), carbon bbers'(C), and polyl'nydric alcohol (D) is determined.
[OO 191 [Polyamide resin (A)]
With respect to polyamide resin (A) used in polyamide resin composition A
of the present invention, there is no particular limitation as long as it is a polyamide
resin obtained by polymerization or copolymerization by a known method, such as
5 melt polymerization, solution polymerization, or solid-phase polymerization.
Examples of polyamide resins (A) include polycaprolactam (polyamide 6),
polyundecanelactam (polyamide 1 I), polydodecanelactam (polyamide 12),
polyethyleneadipamide (polyamide 26), polytetramethyleneadipamide (polyamide 46),
polyhexamethyleneadipamide (polyarnide 66), polyhexamethyleneazelamide
10 (polyarnide 69), polyhexamethylenesebacamide (polyamide 6 1 O),
polyhexamethyleneundecamide (polyamide 6 1 I), polyhexamethylenedodecamide
(polyarnide 6 12), polyhexamethyleneterephthalamide (polyamide 6T),
polyhexamethyleneisophthalamide (polyamide 611,
polyhexarnethylenehexahydroterephthalamide (polyamide 6T(H)),
15 polynonamethyleneadipamide (polyamide 96), polynonamethyleneazelamide
(polyamide 99), polynonamethylenesebacamide (polyamide 9 1 O),
polynonamethylenedodecarnide (polyamide 912), polynonamethyleneterephthalamide
(polyamide 9T), polytrimethylhexamethyleneterephthalamide (polyamide TMHT),
polynonamethylenehexahydroterephthalamide (polyamide 9W-m
20 polynonamethylenenaphthalamide (polyamide 9N), polydecamethyleneadipamide
(polyamide 106), polydecamethyleneazelamide (polyamide 109),
polydecamethylenedecamide (polyamide 10 1 O), polydecamethylenedodecamide
(polyamide 10 12), polydecamethyleneterephthalamide (polyarnide 1 OT),
polydecamethylenehexahydroterephthalamide (polyamide 1 0TQ-W
25 polydecamethylenenaphthalamide (polyamide 1 ON), polydodecamethyleneadipamide
(polyamide 126), polydodecamethyleneazelamide (polyamide 129),
pol ydodecamethylenesebacarnide (polyamide 121 0),
polydodecamethylenedodecamide (polyamide 1212),
polydodecamethyleneterephthalamide (polyamide 12T),
30 polydodecamethylenehexahydroterephthalamide (polyamide 12T(H)),
polydodecamethylenenaphthalamide (polyamide 12N), polymetaxylyleneadipamide
(polyamide MXDG), polymetaxylylenesuberamide (polyamide MXD8),
polymetaxylyleneazelamide (polyamide MXD9), polymetaxylylenesebacamide
(polyamide MXD 1 O), polymetaxylylenedodecamide (polyamide MXD 12),
35 polymetaxylyleneterephthalamide (polyamide MXDT),
polymetaxylyleneiso~hthalamide (polpamida . ' MXDI), -. .
polymetaxylylenenaphthalamide (polyamide ~ N ) Y polybis(4-
aminocyclohexyl)methanedodecamide (polyamide PACM12), polybis(4-
aminocyclohexyl)methaneterephthalamide (polyamide PACMT), polybis(4-
aminocyclohexyl)methaneisophthalamide (polyamide PACMI), polybis(3-methyl-4-
aminocyclohexyl)methanedodecamide (pol yamide dimethylPACM12),
polyisophoroneadipamide (polyamide IPD6), polyisophoroneterephthalamide
(polyamide IPDT), and polyamide copolymers using a raw material monomer for the
above resins. These can be used individually or in combination. Of these,
preferred are polyamide 6, polyamide 12, polyamide 66, polyamide 6/66 copolymer
(which indicates a copolymer of polyamide 6 and polyamide 66; hereinafter, a
copolymer is indicated according to the same manner), polyamide 6/69 copolymer,
polyamide 616 1 0 copolymer, polyamide 616 1 1 copolymer, polyamide 616 12
copolymer, polyamide 6/12 copolymer, polyamide 6/66/12 copolymer, polyamide
6IIPD6 copolymer, and polyamide MXD6, more preferred are polyamide 6,
polyamide 12, polyamide 66, polyamide 6/66 copolymer, polyamide 6/12 copolymer,
polyamide 6IIPD6 copolymer, and polyamide 6/66/12 copolymer, and further
preferred are polyamide 6, polyamide 66, and polyamide 6/66 copolymer, and, from
the viewpoint of achieving excellent molding processability, polyamide 6 is especially
preferred.
[OO2O] With respect to the type of the terminal group, the concentration, and the
molecular weight distribution of polyamide resin (A) in the present invention, there is
no particular limitation, and, for controlling the molecular weight and stabilizing the
melted resin during the molding, as a molecular weight modifier, a monocarboxylic
acid, such as acetic acid or stearic acid, a diamine, such as metaxylylenediamine or
isophoronediamine, a monoamine, and a dicarboxylic acid can be used individually or
in appropriate combination.
[0021] Polyamide resin (A) can be produced by means of an apparatus for
producing polyamide, e.g., a batch reactor, a single-reactor or multi-reactor
continuous reaction apparatus, a tubular continuous reaction apparatus, or a kneading
reaction extruder, such as a single-screw extruder or a twin-screw extruder.
Examples of polymerization methods include melt polymerization, solution
polymerization, and solid-phase polymerization. These polymerization methods can
be conducted by repeating operations under atmospheric pressure, under a reduced
pressure, and under a pressure, and can be used individually or in appropriate
combination.
[OO22] * -The relative viscosity of polyarnide resin (A), as measured in acc~rdance
with JIS K-6920 under conditions such that the concentration of the polyamide in 96%
by mass sulfivic acid is 1% by mass and the temperature is 25"C, is preferably 1.0 to
6.0, especially preferably 1.5 to 5.0, more preferably 1.7 to 4.5. When the relative
viscosity of the polyamide resin is less than the above-mentioned value, the resultant
5 molded article may be reduced in mechanical properties. On the other hand, when
the relative viscosity of the polyamide resin exceeds the above-mentioned value, the
viscosity of the melted composition may be increased, making it difficult to mold the
composition into a molded article. Further, fiom the viewpoint of achieving
excellent productivity of the polyamide resin composition of the present invention and
10 excellent moldability of the molded article, the relative viscosity of polyarnide resin
(A) is further preferably 2.0 to 3.0.
[0023 J With respect to the water extraction of polyamide resin (A) as measured in
accordance with the method described in JIS IS-6920 for measuring a low molecularweight
substance content, there is no particular limitation, but there is a possibility
15 that gas and others generated during the molding cause environmental problems, or
adhere to the production facilities to lower the productivity or adhere to product
pellets to cause the appearance to be poor, and therefore the water extraction of
polyamide resin (A) is preferably 5% by mass or less.
100241 The form of particles of polyamide resin (A) is preferably a powdery form
20 having an average particle size of 1 mm or less fiom the viewpoint of uniformly
mixing flake graphite (B) and other additives. With respect to the method for
obtaining a powdery form, there is no particular limitation, but, fiom the viewpoint of
achieving excellent productivity of the powder, freeze-grinding is preferred.
[0025] In polyamide resin (A) in the present invention, various additives and
25 modifiers generally incorporated to a resin can be added in such an amount that the
properties of the resultant molded article are not sacrificed. For example, a heat
stabilizer, an ultraviolet light absorber, a light stabilizer, an antioxidant, an antistatic
agent, a lubricant, an anti-blocking agent, a filler, a tackifier, a sealing property
improving agent, an anti-fogging agent, a crystal nucleating agent, a release agent, a
30 plasticizer, a crosslinking agent, a foaming agent, a coloring agent (e.g., a pigment or
a dye), and the like can be added. With respect to the method for adding the above
additive, there is no particular limitation, and various types of methods conventionally
known can be employed. For example, the additive can be added by a dry blending
method, or by a melt kneading method, together with another component incorporated
35 if necessary. Melt-kneading can be made using a kneader, such as a single-screw
- extruder, a fivin.screw extruder,-a kneader, or a Banbury mixer: -- - .- - ,
Polyamide resin composition A of the present invention contains flake
graphite (B), carbon fibers (C), and polyhydric alcohol (D).
[0026][Flake graphite (B)]
Flake graphite (B) used in polyamide resin composition A of the present
invention is obtained by refining natural graphite and processing the resultant graphite
having an increased purity into a flake form. With respect to the average particle
size of the flake graphite, there is no particular limitation, but the average particle size
is generally 1 to 100 ym, preferably 5 to 80 pm. When the average particle size of
the flake graphite is less than 1 pm, the flake graphite has an increased bulk specific
gravity, that is, the volume of air per unit volume is increased, and therefore the
weight of the graphite which can be introduced to a hopper during the melt-kneading
is reduced, and thus the number of the operations of introducing the graphite to the
hopper is inevitably increased, and this is not preferred from the viewpoint of
production efficiency. On the other hand, when the average particle size of the flake
graphite is 100 pm or more, mechanical strength, such as an impact strength, tends to
lower.
With respect to the aspect ratio (average particle sizdaverage thickness) of
flake graphite (B) used in polyamide resin composition A of the present invention,
there is no particular limitation, but, from the viewpoint of achieving excellent
mechanical properties including impact strength and excellent thermal conduction
properties, the aspect ratio is advantageously 30 to 300 on average, preferably 30 to
200 on average, more preferably 30 to 150 on average.
From the viewpoint of achieving excellent productivity and excellent
thermal conduction properties as well as excellent mechanical properties, the amount
of flake graphite (B) incorporated into polyamide resin composition A of the present
invention is, relative to 100 parts by volume of polyamide resin (A), preferably 50 to
less than 100 parts by volume, more preferably 60 to 97 parts by volume, further
preferably 70 to 93 parts by volume, especially preferably more than 80 to 91 parts by
volume.
[0027] [Carbon fibers (C)]
Carbon fibers (C) used in polyamide resin composition A of the present
invention are PAN carbon fibers obtainable by carbonizing polyacrylonitrile fibers.
[0028] With respect to the fiber length of carbon fibers (C), short fibers may be
used according to the use, and continuous fibers having a fiber length as large as 1,000
mm may be used, and, fkom the viewpoint of achieving excellent productivity
including feeding properties to a twin-screw extrudes, the fiber length of the carbon -. -
fibers before kneaded is preferably 0.1 to 20 mm, more preferably 1 to 15 mrn.
[0029] With respect to the fiber diameter of carbon fibers (C), there is no particular
limitation. The carbon fibers having a smaller fiber diameter are likely to exhibit a
strength in the resin composition or molded article, but the carbon fibers having too
small a fiber diameter may be fibrillated, for example, when being fed to a kneader,
lowering the production efficiency in the kneading. From the viewpoint of achieving
excellent productivity in a kneader and excellent mechanical properties including
strength, the fiber diameter is preferably 5 to 15 p. A masterbatch preliminarily
having carbon fibers contained in a resin at a high content or granulated carbon fibers
are unlikely to cause the carbon fibers to be fibrillated during the production of the
polyamide resin composition of the present invention, and therefore are preferred
when using carbon rnicrofibers.
[0030] From the viewpoint of achieving excellent productivity and excellent
thermal conduction properties as well as excellent mechanical properties, the amount
of carbon fibers (C) incorporated into polyarnide resin composition A of the present
invention is, relative to 100 parts by volume of polyamide resin (A), preferably 5 to
less than 40 parts by volume, more preferably 6 to 30 parts by volume, further
preferably 8 to 20 parts by volume.
[003 l][Polyhydric alcohol (D)]
With respect to the polyhydric alcohol used in polyamide resin composition
A of the present invention, there is no particular limitation, but a polyhydric alcohol
having a melting temperature of 150 to 280°C is preferred. The melting temperature
means a temperature at an endothermic peak (melting point) as measured by
differential scanning calorimetry (DSC) used for measuring a melting point and a
fieezing point of a resin. Examples of polyhydric alcohols having a melting
temperature of 150 to 280°C include pentaerythritol, dipentaerythritol, and
trimethylolethane, and these can be used in combination. From the viewpoint of
achieving excellent kneading properties and excellent rnoldability, pentaerythritol
andlor dipentaerythritol is preferred.
[0032] Further, fiom the viewpoint of achieving excellent kneading properties and
excellent moldability, the amount of polyhydric alcohol @) incorporated into
polyamide resin composition A of the present invention is, relative to 100 parts by
volume of the polyamide resin, preferably 0.1 to 5 parts by volume, more preferably
0.5 to 3 parts by volume.
COO331 In polyamide resin composition A, fiom the viewpoint of achieving
excellent proc!uctivity and exceltent~thermacl onduction propcdes as-well as excellent
mechanical properties, the amount of flake graphite (B) is, relative to 100 parts by
volume of polyamide resin (A), preferably 50 to less than 100 parts by volume, more
preferably 97 parts by volume or less, further preferably 70 to 93 parts by volume,
especially preferably more than 80 to 91 parts by volume. From the viewpoint of
achieving excellent productivity and excellent thermal conduction properties as well
as excellent mechanical properties, the amount of carbon fibers (C) is, relative to 100
parts by volume of polyamide resin (A), preferably 5 to less than 40 parts by volume,
more preferably 6 to 30 parts by volume, more preferably 8 to 20 parts by volume.
From the viewpoint of achieving excellent kneading properties and excellent
moldability, the amount of polyhydric alcohol @) is, relative to 100 parts by volume
of polyamide resin (A), preferably 0.1 to 5 parts by volume, more preferably 0.5 to 3
parts by volume.
[0034] With respect to the method for producing polyamide resin composition A of
the present invention, there is no particular limitation as long as the composition is
produced by melt-kneading, and various types of methods conventionally known can
be employed. For example, the polyamide resin composition can be produced using
a kneader, such as a single-screw extruder, a twin-screw extruder, a kneader, or a
Banbury mixer. Especially, the polyamide resin composition of the present
invention can be preferably produced using a single-screw extruder or a twin-screw
extruder.
[0035] As a method for molding polyamide resin composition A of the present
invention into a molded article, a molding method, such as injection, extrusion, or
pressing, can be employed. The polyamide resin composition can be processed by
the above molding method into, e.g., a molded article or a sheet.
The molded product using polyamide resin composition A of the present
invention can be used in various types of molded articles, sheets and fibers in which a
molded product of a polyamide resin composition has conventionally been used, and a
wide variety of applications, such as automobile members, computers and associated
devices, optical device members, electric and electronic devices, information and
communication devices, precision devices, civil engineering and construction products,
medical products, and household products. The molded product using polyamide
resin composition A is especially useful in applications, such as automobiles and
electric and electronic devices.
[0036j[l?olyamide resin composition B]
The present invention can be polyamide resin composition B which
comprises palyamide resin CAI) comprising dicsuboxyk--acid units (x) and diamine . - -.
units (y) as constitutional units, and at least one member selected from the group
consisting of metal oxide @I), nitrogen compound @2), and silicon compound @3),
wherein dicarboxylic acid units (x) of polyamide resin (Al) are oxalic acid in an
amount of 70 mol% or more, based on the total mole of dicarboxylic acid units of
polyamide resin (Al).
[0037][Polyamide resin (Al)]
In polyamide resin (Al) in polyamide resin composition B of the present
invention, dicarboxylic acid units (x) are oxalic acid in an amount of 70 mol% or
more, preferably 80 mol% or more, more preferably 90 mol% or more, further
preferably 98 to 100 mol%, based on the total mole of the dicarboxylic acid units.
[0038] With respect to the oxalic acid source of dicarboxylic acid units (x), an
oxalic diester is used, and, with respect to the oxalic diester, there is no particular
limitation as long as it has reactivity with an amino group, and examples include
oxalic diesters of an aliphatic monohydric alcohol, such as dimethyl oxalate, diethyl
oxalate, di-n-(or i-)propyl oxalate, and di-n-(, i-, or t-)butyl oxalate; oxalic diesters of
an alicyclic alcohol, such as dicyclohexyl oxalate; and oxalic diesters of an aromatic
alcohol, such as diphenyl oxalate.
[0039] Among the above-mentioned oxalic diesters, preferred are oxalic diesters of
an aliphatic monohydric alcohol having more than 3 carbon atoms, oxalic diesters of
an alicyclic alcohol, and oxalic diesters of an aromatic alcohol, and, of these, more
preferred are dibutyl oxalate and diphenyl oxalate.
[0040] Polyamide resin (Al) can contain other dicarboxylic acid units (x), lactam
units, and aminocarboxylic acid units as long as dicarboxylic acid units (x) comprise
oxalic acid in an amount of 70 mol% or more, based on the total mole of the
dicarboxylic acid units.
[0041] Examples of other dicarboxylic acid units include aliphatic dicarboxylic
acids, such as malonic acid, dimethyl malonate, succinic acid, glutaric acid, adipic
acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedicarboxylic acid,
dodecanedicarboxylic acid, tridecanedicarboxylic acid, tetradecanedicarboxylic acid,
pentadecanedicarboxylic acid, hexadecanedicarboxylic acid, octadecanedicarboxylic
acid, and eicosanedicarboxylic acid; alicyclic dicarboxylic acids, such as 1,3-/1,4-
cyclohexanedicarboxylic acid, dicyclohexanemethane-4,4'-dicarboxylic acid, and
norbornanedicarboxylic acid; and aromatic dicarboxylic acids, such as isophthalic
acid, terephthalic acid, and 1,4-/2,6-/2,7-naphthalenedicarboxylica cid. These can be
used individually or in combination.
Examples. -of-- laetam units include caprokctm; -.-~ enantholactam, :
undecanelactam, dodecanelactam, and a-pyrrolidone. These can be used
individually or in combination.
Examples of aminocarboxylic acid units include aminocaproic acid and
aminododecanoic acid.
[0042] In polyamide resin composition B of the present invention, examples of
diarnine units (y) of polyamide resin (Al) include aliphatic diamines, such as 1,2-
ethylenediamine, 1,3-trimethylenediamine, 1,4-tetramethylenediamine, 1,spentamethylenediamine,
1,6-hexamethylenediamine (1,6-hexmediamine), 1,7-
heptamethylenediamine, 1,8-octamethylenediamine, 1,9-nonamethylenediamine, 2-
methyl- I ,8-octanediamine, 1 , 1 0-decamethylenediamine, 1,llundecamethylenediamine,
1,12-dodecamethylenediamine, 1,13-
tridecamethylenediamine, 1,14-tetradecamethylenediamine, 1,15-
pentadecamethylenediamine, 1,16-hexadecarnethylenediamine, 1,17-
heptadecamethylenediarnine, I, 1 8-octadecamethylenediamine, 1,19-
nonadecamethylenediamine, 1,20-eicosamethylenediamine, 2-13-methyl-1 ,5-
pentanediamine, 2-methyl- l,8-octanediamine, 2,2,4-/2,4,4-
trimethylhexamethylenediamine, and 5-methyl-l ,9-nonanediamine;a licyclic diamines,
such as 1,3-11,4-cyclohexanediamine, 1,3-11,4-cyclohexanedimethylamine, bis(4-
aminocyclohexyl)methane, bis(4-aminocyclohexyl)propane, bis(3-methyl-4-
aminocyclohexyl)methane, bis(3-methyl-4-aminocyclohexyl)propane, 5-amino-2,2,4-
trimethyl- 1 -cyclopentanemethylamine, 5-amino- 1,3,3 -
trimethylcyclohexanemethylamine (isophoronediamine), bis(aminopropyl)piperazine,
bis(aminoethyl)piperazine, norbornanedimethylamine, and
tricyclodecanedimethylamine; and aromatic diamines, such as p-phenylenediamine,
m-phenylenediamine, m-xylylenediamine, p-xylylenediamine, 4,4'-diaminodiphenyl
sulfone, and 4,4'-diaminodiphenyl ether. Of these, preferred are 1,6-
hexamethylenediamine (1,6-hexmediamine), 1,9-nonamethylenediamine, %-methyl-
1,8-octanediamine, 1 ,1 0-decamethylenediamine, 1,ll -undecamethylenediamine, 1,12-
dodecamethylenediamine, m-xylylenediamine, and p-xylylenediamine, more preferred
are 1,6-hexamethylenediamine (1,6-hexanediamine), 1,9-nonamethylenediamine, 2-
methyl-1,8-octanediarnine, and m-xylylenediamine, and further preferred are 1,9-
nonamethylenediarnine and 2-methyl-l,8-octanediamine. These can be used
individually or in combination.
[0043] When 1,9-nonamethyienediamine and 2-methyl- l,8-octanediamine are
mixed, molar ratio of the 1,9-nonamethylenediaminet o 2-methyl-l,8-octanediamineis
1:99 to 99:1,p referably S:95 fd 955;-riiorep referably Si95 to 40:60 or 60:$0=t6 955, -:-
particularly 5:95 to 30:70 or 70:30 to 90:lO. By copolymerizing 1,9-
nonamethylenediamine and 2-methyl-1,8-octanediamine in the above-mentioned
specific amounts, there can be obtained polyamide resin (Al) advantageous not only
in that it has a broad width of the temperature at which the resin can be molded, but
also in that it exhibits excellent melt moldability as well as excellent chemical
resistance and excellent resistance to hydrolysis.
[0044] In polyamide resin composition B of the present invention, specific
examples of polyamide resins (Al) include polyamide 62, polyamide 82, polyamide
92, polyamide 102, polyamide 122, polyamide 62/92 copolymer, polyamide 62/102
copolymer, polyamide 62/122 copolymer, polyamide 92/102 copolymer, and
polyamide 921122 copolymer. These can be used individually or in combination.
From the viewpoint of achieving excellent resistance to hydrolysis and excellent
molding processability, . preferred are polyamide 92, polyamide 122, and polyamide
62/92 copolymer, and polyamide 92 is more preferred.
[0045] Polyamide resin (Al) in polyamide resin composition B of the present
invention is a polymer comprising a salt of oxalic acid which is a dicarboxylic acid,
and a diamine as polymerization units, and therefore is generally called polyamide.
A salt of oxalic acid and a diamine is referred to as oxamide, and hence a polymer
comprising an oxamide as polymerization units is referred to also as polyoxamide.
[0046] Polyamide resin (Al) used in polyamide resin composition B of the present
invention can be produced using an arbitrary method known as a method for
producing polyamide, for example, a solution polymerization method, an interfacial
polymerization method, a melt polymerization method, or a solid-phase
polymerization method. Specifically, the polyamide resin can be obtained by
reacting a diamine and an oxalic diester with each other in a batchwise manner or in a
continuous manner, and the operations for the production are preferably conducted in
the order of (i) the former polymerization step and (ii) the latter polymerization step
shown below.
[0047] In the former polymerization step (i), after or while purging a reactor with
nitrogen, dicarboxylic acid units (x) and diamine units (y) are mixed with each other.
A solvent capable of dissolving therein both dicarboxylic acid units (x) and diamine
units (y) may be used in mixing them. With respect to the solvent capable of
dissolving therein both diamine units (y) and an oxalic diester as dicarboxylic acid
units (x), there is no particular limitation, but, for example, toluene, xylene,
trichlorobenzene, phenol, or trifluoroethanol can be used, and toluene can be
especially prefsrably used. -For example, a toluene solution. baving a .diamine
dissolved is heated to 50°C and then, an oxalic diester is added to the solution. In
this instance, the ratio of the charged oxalic diester to the charged diamine is 0.8 to
1.5, preferably 0.91 to 1.1, further preferably 0.99 to 1.01, in terms of the oxalic
diesterldiamine ratio (molar ratio).
[0048] The elevation of the temperature in the reactor into which the materials are
charged as mentioned above is started under atmospheric pressure while stirring
and/or introducing a jet of bubbles using nitrogen, so that the temperature in the
reactor and the pressure in the reactor preferably finally become 100 to 270°C and
atmospheric pressure, respectively, in this step.
[0049] In the latter polycondensation step (ii), for further increasing the molecular
weight of the polymerization product formed in the previous step, the temperature of
the polymerization product formed in the previous step is gradually elevated in the
reactor under atmospheric pressure. In the temperature elevation process, the
temperature is elevated from the final temperature in the former polycondensation step
finally to a temperature in the range of 220 to 300°C, preferably 230 to 280°C, further
preferably 240 to 270°C. The reaction is preferably conducted for 1 to 8 hours, .
preferably 2 to 6 hours, including the temperature elevation time. Further, in the the
latter polymerization step, if necessary, the polymerization can be conducted under a
reduced pressure.
[0050] In the production of polyamide resin (Al), as a catalyst, phosphoric acid,
phosphorous acid, hypophosphorous acid, or a salt or ester thereof can be used.
Specific examples of catalysts include metal salts, such as potassium, sodium,
magnesium, vanadium, calcium, zinc, cobalt, manganese, tin, tungsten, germanium,
titanium, and antimony salts, ammonium salts, ethyl esters, isopropyl esters, butyl
esters, hexyl esters, isodecyl esters, octadecyl esters, decyl esters, stearyl esters, and
phenyl esters.
[0051] With respect to the relative viscosity of polyamide resin (Al) in polyamide
resin composition B of the present invention, there is no particular limitation, but,
fiom the viewpoint of achieving excellent molding processability and excellent impact
properties, the relative viscosity of a solution having a polyamide resin concentration
of 1.0 g/dl using 96% by mass sulfuric acid as a solvent as measured at 25OC is
preferably 1.8 to 6.0, more preferably 2.0 to 5.5, further preferably 2.5 to 4.5.
[0052] In polyamide resin composition B of the present invention, with respect to
the melting temperature of polyamide resin (Al), there is no particular limitation, but
the melting temperature is preferably 150 to 350°C, and, fiom the viewpoint of
achieving excellent mdlding processability, the melting teqerafure of polyamide:)
resin (Al) is more preferably 200 to 300°C.
[0053] With respect to the form of particles of polyamide resin (Al), there is no
particular limitation, but, from the viewpoint of uniformly mixing metal oxide (Bl), a
powdery form having an average particle size of 1 mm or less is preferred. With
respect to the method for obtaining a powdery form, there is no particular limitation,
but, from the viewpoint of achieving excellent productivity of the powder, fieezegrinding
is preferred.
In polyamide resin (Al) in polyamide resin composition B of the present
invention, another polyamide resin can also be used in such an amount that the
properties of the resultant molded article are not sacrificed.
[0054] Examples of other polyamide resins include polycaprolactam (polyamide 6),
polyundecanelactam (polyamide 1 l), polydodecanelactam (polyamide 12),
polyethyleneadipamide (polyamide 26), polytetramethyleneadipamide (polyamide 46),
polyhexamethyleneadipamide (polyamide 66), polyhexamethyleneazelamide
(polyamide 69), polyhexamethylenesebacamide (polyamide 610),
polyhexamethyleneundecamide (polyamide 61 l), polyhexamethylenedodecamide
(polyamide 612), polyhexamethyleneterephthalamide (polyamide 6T),
polyhexamethyleneisophthalamide (polyamide 611,
polyhexarnethylenehexahydroterephthalarnide (polyamide 6T(H)),
polynonamethyleneadipamide (polyamide 96), polynonamethyleneazelamide
(polyamide 99), polynonamethylenesebacamide (polyamide 910),
pol ynonamethylenedodecamide (polyamide 9 12), polynonamethyleneterephthalamide
(polyamide 9T), polytrimethylhexamethyleneterephthalamide (polyamide TMHT),
polynonamethylenehexahydroterephthalamide (pol yamide 9T(H)),
polynonamethylenenaphthalamide (polyarnide 9N), polydecamethyleneadipamide
(polyamide 106), polydecamethyleneazelamide (polyamide 1091,
polydecamethylenedecarnide (polyamide 1 0 1 O), polydecarnethylenedodecamide
(polyamide 10 12), polydecamethyleneterephthalamide (polyamide 1 OT),
polydecamethylenehexahydroterephthalamide (polyamide 1 OT(H)),
polydecamethylenenaphthalamide (polyamide 1 ON), polydodecamethyleneadipamide
(polyamide 126), polydodecamethyleneazelamide (polyamide 129),
polydodecamethylenesebacamide (polyamide 1210),
polydodecamethylenedodecamide (polyamide 1212),
polydodecamethyleneterephthalamide (polyamide 12T),
polydodecamethylenehexahydroterephthalamide (pol yamide 12T(H)),
polydodecamethylenemphtha1amide (polyamide. 12N), polyrnetaxylyleneadipamide
(polyamide MXD6), polymetaxylylenesuberamide (polyamide MXD8),
polymetaxyIyleneazelamide (polyamide MXDg), polymetaxylylenesebacamide
(polyamide MXD 1 O), polymetaxyl ylenedodecamide (polyamide MXD 1 2),
polymetaxylyleneterephthalarnide (polyamide MXDT),
polymetaxylyleneisophthalamide (polyamide MxDI),
polymetaxylylenenaphthalamide (polyamide ~ N > Y polybis(4-
aminocyclohexyl)methanedodecamide (polyarnide PACMlZ), polybis(4-
aminocyclohexyl)methaneterephthalamide (polyamide PACMT), polybis(4-
aminocyclohexyl)methaneisophthalamide (polyamide PACMI), poiybis(3-methyl4
aminocyclohexyl)methanedodecamide (polyamide dimethylPACM 12),
polyisophoroneadipamide (polyamide IPD6), polyisophoroneterephthalamide
(polyamide IPDT), and polyarnide copolymers thereof. These can be used
individually or in combination. Of these, preferred are polyamide 6, polyamide 12,
polyamide 66, polyamide 6/66 copolymer (which indicates a copolymer of polyamide
6 and polyamide 66; hereinafter, a copolymer is indicated according to the same
method), polyamide 6/12 copolymer, and polyamide 6/66/12 copolymer, and more
preferred are polyamide 6, polyamide 66, polyamide 6/66 copolymer, and polyamide
6/12 copolymer.
100551 In polyamide resin (Al) in polyamide resin composition B of the present
invention, various additives and modifiers generally incorporated to a resin can be
added in such an amount that the properties of the resultant molded article are not
sacrificed. For example, a heat stabilizer, an ultraviolet light absorber, a light
stabilizer, an antioxidant, an antistatic agent, a lubricant, an anti-blocking agent, a
filler, a tackifier, a sealing property improving agent, an anti-fogging agent, a crystal
nucleating agent, a release agent, a plasticizer, a crosslinking agent, a foaming agent, a
coloring agent (e.g., a pigment or a dye), and the like can be added during ox after the
polymerization of the resin.
[0056][At least one member selected from the group consisting of metal oxide (Bl),
nitrogen compound @2), and silicon compound (B3)]
With respect to the average particIe size of the at least one member selected
from the group consisting of metal oxide (Bl), nitrogen compound (B2), and silicon
compound (B3) used in polyamide resin composition B of the present invention, there
is no particular limitation, but, from the viewpoint of achieving excellent physical
properties including impact resistance, the average particle size is especially
preferably 0.1 to 200 pm, more preferably 1 to 150 pm, fkther preferably 5 to 100
pm. With. respect to the fom-vf the particles, there i s no particular: limitation; but;
from the viewpoint of achieving excellent productivity and excellent moldability,
preferred is a particulate form, particularly a round particulate form having a small
specific surface area.
[0057] With respect to the specific surface area of the at least one member selected
fiom the group consisting of metal oxide (Bl), nitrogen compound (B2), and silicon
compound (B3), there is no particular limitation, but the specific surface area is
preferably 5 m2/g or less, more preferably 1 m21g or less.
[0058] With respect to the purity of the at least one member selected from the
group consisting of metal oxide (Bl), nitrogen compound (B2), and silicon compound
(B3), there is no particular limitation, but, from the viewpoint of obtaining excellent
electrical insulating properties and excellent thermal conduction properties, the purity
is preferably 70% by mass or more, more preferably 80% by mass or more, further
preferably 90% by mass or more, especially preferably 95% by mass or more.
[0059] With respect to the apparent specific gravity of the at least one member
selected from the group consisting of metal oxide (Bl), nitrogen compound (B2), and
silicon compound @3), there is no particular limitation, but, fiom the viewpoint of
achieving excellent handling properties in the production (prevention of scattering),
the apparent specific gravity is preferably 0.1 g/cm3 or more.
[0060] With respect to the surface treatment for the at least one member selected
fiom the group consisting of metal oxide (Bl), nitrogen compound (B2), and silicon
compound (B3), there is no particular limitation, and examples include a silane
coupling agent and organopolysiloxane.
[0061] Examples of metal oxides 1) include aluminum oxide, magnesium oxide,
beryllium oxide, and titanium oxide, and, fiom the viewpoint of obtaining excellent
electrical insulating properties and excellent thermal conduction properties, preferred
are aluminum oxide and magnesium oxide, and magnesium oxide is more preferred.
[0062] Examples of nitrogen compounds (B2) include boron nitride and aluminum
nitride, and boron nitride is preferred.
[0063] As an example of silicon compound (B3), there can be mentioned calcium
silicate whiskers.
One type or two types or more can be used.
[0064] In polyamide resin composition B of the present invention, with respect to
the at least one member selected fiom the group consisting of metal oxide (Bl),
nitrogen compound (B2), and silicon compound (B3), preferred is metal oxide (Bl)
fiom the viewpoint of the availability of the raw material.
I00651 Poljwnide resin composit'isn B of the present fiivention eoinprises; relative
to 100 parts by mass of polyamide resin (Al), preferably 25 to 900 parts by mass,
more preferably 33 to 600 parts by mass, further preferably 42 to 300 parts by mass,
especially preferably 100 to 250 parts by mass of at least one member selected fiom
the group consisting of metal oxide (Bl), nitrogen compound (B2), and silicon
5 compound (B3).
[0066] In polyamide resin composition By a thermoplastic polymer other than the
polyamide, an elastomer, a filler, or reinforcing fibers can be added like the abovementioned
polyamide resin (Al) in such an amount that the desired effects are not
sacrificed.
10 [0067] In polyarnide resin composition B, if necessary, a stabilizer, such as a
copper compound, a coloring agent, an ultraviolet light absorber, a light stabilizer, an
antioxidant, an antistatic agent, a flame retardant, a crystallization promoter, glass
fibers, a plasticizer, a lubricant, or the like can be further added.
[0068] With respect to the method for producing polyamide resin composition B of
15 the present invention, there is no particular limitation, but, generally, there can be
mentioned the following method.
to0691 First, polyamide resin (Al), at least one member selected from the group
consisting of metal oxide (Bl), nitrogen compound (B2), and silicon compound (B3),
and an additive mentioned above as an arbitrary component are provided.
20 [0070] Then, polyamide resin (Al), at least one member selected fiom the group
consisting of metal oxide (Bl), nitrogen compound (B2), and silicon compound (B3),
and an additive as an arbitrary component are mixed with one another using, e.g., a
cylinder mixer. The resultant mixture is melt-kneaded by means of a known extruder,
such as a twin-screw extruder, a single-screw extruder, a multi-screw extruder, a
25 Banbury mixer, a roll mixer, or a kneader, to produce a polyamide resin composition.
[0071] Examples of methods for molding polyamide resin composition B of the
present invention into a molded article include injection molding, extmsion, blow
molding, press molding, roll molding, foam molding, vacuum or pressure forming,
and stretch forming. Of these, preferred are methods by melt processing, such as
30 injection molding, extrusion, blow molding, press molding, roll molding, and foam
molding. Polyamide resin composition B of the present invention can be processed
by the above molding method into, e.g., a molded article, a film, a sheet, ox fibers.
[0072] The molded product using polyamide resin composition B of the present
invention can be used in various types of molded articles in which a molded product
35 of a polyamide resin composition has conventionally been used, and a wide variety of
applications, s y h as sheets, films, pipes, tubes, monofdaments, fibers, automobiles,
computers and associated devices, optical devices, information and communication
devices, electric and electronic device parts for precision devices, civil engineering
and construction products, medical products, and household products. The molded
product using polyamide resin composition B is especially usefbl in applications of
electric and electronic device parts, which require not only the inherent properties of
the polyamide resin but also electrical insulating properties and thermal conduction
properties.
[0073][Polyamide resin composition C]
The present invention can be polyarnide resin composition C which
comprises polyamide resin (A) and metal oxide particles (BB) as the property
imparting component, wherein metal oxide particles (BB) contain those having a
particle size of 70 pn or more in an amount of 10 to 50% by mass and those having a
particle size of 20 pm or less in an amount of 1 to 50% by mass, based on the total
mass of the metal oxide particles, wherein metal oxide particles (BB) are contained in
an amount of 70 to 85% by mass, based on the mass of the polyarnide resin
composition.
[0074] Polyarnide resin (A) in polyamide resin composition C of the present
invention can be produced in the same manner as in polyamide resin (A) described
above in connection with polyamide resin composition A, and the same materials can
be used and the same additives can be added.
[0075] The amount of polyamide resin (A) incorporated into polyamide resin
composition C of the present invention is preferably 15 to 30% by mass, based on the
mass of polyamide resin composition C. When the amount of polyamide resin (A) is
less than 15% by mass, the resultant composition has a reduced resin component and
hence becomes brittle, making it difficult to pelletize the strand. Further, the amount
of the melted component (resin component) in the composition being kneaded is
reduced to lower the fluidity, so that the kneading properties become poor. On the
other hand, when the amount of polyarnide resin (A) is more than 30% by mass, the
amount of metal oxide particles (BB) incorporated is reduced, so that satisfactory
thermal conduction properties cannot be exhibited. From the viewpoint of achieving
excellent kneading properties and excellent thermal conduction properties, the amount
of polyamide resin (A) incorporated into polyamide resin composition C is preferably
14.9 to 29.9% by mass, more preferably 20 to 25% by mass.
[0076][Metal oxide particles (BB)]
Examples of metal oxide particles (BB) used in polyamide resin
composition C-'of the present -invention include p ~ o ~ oef sa iuminum-.o xide,
magnesium oxide, beryllium oxide, and titanium oxide, and, fiom the viewpoint of
obtaining excellent electrical insulating properties and excellent thermal conduction
properties, aluminum oxide andlor magnesium oxide is preferred, and magnesium
oxide is more preferred.
[0077] In polyamide resin composition C of the present invention, metal oxide
particles (BB), which are processed into a powdery form, are used, and, with respect
to the average particle size of metal oxide particles (BB), there is no particular
limitation, but, when the average particle size is less than 0.5 pm, the increased
surface area may cause the particles to absorb too large an amount of moisture in air,
and, when the average particle size is more than 300 pm, the mechanical strength
including impact strength is likely to Iower, and magnesium oxide may be exposed
through the surface of the molded article, causing the surface properties to become
poor. Therefore, the average particle size of metal oxide particles (BB) is preferably
0.5 to 300 pm, more preferably 12 to 73 p, further preferably 30 to 60 pm.
[0078] In polyamide resin composition C of the present invention, metal oxide
particles (BB) contain those having a particle size of 70 pm or more in an amount of
10 to 50% by mass, preferably in an amount of 10 to 30% by mass from the viewpoint
of achieving excellent physical properties including impact resistance, and contain
those having a particle size of 20 p or less in an amount of 1 to 50% by mass, fiom
the viewpoint of achieving excellent stability of raw material transfer including
feeding of raw materials during the kneading, more preferably in an amount of 15 to
45% by mass, based on the total mass of the metal oxide particles. Further, from the
viewpoint of achieving excellent physical properties including impact resistance and
excellent kneading properties, the metal oxide particles preferably contain metal oxide
particles having a particle size of more than 20 to less than 70 p in an amount of 40
to 70% by mass, more preferably 40 to 52% by mass.
[0079] Further, in polyamide resin composition C of the present invention, fiom the
viewpoint of achieving excellent thermal conduction properties, metal oxide particles
(BB) preferably have a purity of 80% by mass or more, more preferably 90% by mass
or more, further preferably 95% by mass or more.
The amount of metal oxide particles (BB) incorporated into polyamide resin
composition C of the present invention is 70 to 85% by mass, based on the mass of
polyamide resin composition C. When the amount of metal oxide particles (BB) is
less than 70% by mass, the amount of the resin in the composition is increased, so that
satisfactory thermal conduction properties cannot be exhibited. When the amount of
metal oxide paticles (BB) is more-than 85%'by mass, the resultant strand has a
reduced resin amount and hence becomes brittle, making it difficult to pelletize the
strand during the kneading. From the viewpoint of achieving excellent thermal
conduction properties and excellent kneading properties, the amount of metal oxide
particles (BB) is preferably 70 to 85% by mass, more preferably 75 to 85% by mass.
5 [0080] It is preferred that polyamide resin composition C of the present invention
further comprises the above-mentioned polyhydric alcohol @). In polyamide resin
composition C of the present invention, polyhydric alcohol (D) is preferably a
polyhydric alcohol having a melting temperature of 150 to 280°C, and examples of
such polyhydric alcohols include pentaerythritol, dipentaerythritol, and
10 trimethylolethane, and these can be used in combination. From the viewpoint of
achieving excellent kneading properties and excellent moldability, pentaerythritol
andlor dipentaerythritol is preferred.
[0081] Further, the amount of polyhydric alcohol (D) incorporated into polyamide
resin composition C of the present invention is preferably 0.1 to 5% by mass fiom the
15 viewpoint of achieving excellent kneading properties and excellent moldability.
From the viewpoint of surely obtaining fluidity of the composition and suppressing
the generation of gas during the molding, the amount of polyhydric alcohol (D) is
more preferably 0.5 to 3% by mass.
[0082] With respect to the method for producing polyamide resin composition C of
20 the present invention, like the method for producing polyamide resin composition A,
there is no particular limitation as long as the composition is produced by meltkneading,
and various types of methods conventionally known can be employed.
[0083] In polyamide resin composition C of the present invention, various additives
and modifiers generally incorporated to a resin composition can be added in such an
25 amount that the properties of the resultant molded article are not sacrificed. For
example, a heat stabilizer, an ultraviolet light absorber, a light stabilizer, an
antioxidant, an antistatic agent, a lubricant, an anti-blocking agent, a filler, an antifogging
agent, a crystaI nucleating agent, a release agent, a plasticizer, a crosslinking
agent, a foaming agent, a coloring agent (e.g., a pigment or a dye), and the like can be
30 added. With respect to the method for adding the above additive, there is no
particular limitation, and, in addition to the above-mentioned methods for producing
the composition, various types of methods conventionally known can be employed.
For example, there can be mentioned a dry blending method.
[0084] A method for molding the obtained polyamide resin composition C into a
35 molded article is the same method as described above in connection with polyamide
resin composition A. . .., . .
[0085] A thermal conductivity of the molded article obtained from polyamide resin
composition C of the present invention is measured in accordance with JIS R-2616,
and a difference between the maximum and minimum of the thermal conductivity, i.e.,
a thermal conductivity difference within the molded article is preferably 0.5 W1m.K
or less.
The molded product using polyamide resin composition C of the present
invention is used in the same applications as described above in connection with
polyarnide resin composition A.
Examples
[0086] Hereinbelow, the present invention will be described in more detail with
reference to the following Examples, which should not be construed as limiting the
scope of the present invention.
[0087]
Various evaluation methods and the raw materials used are shown below.
(Raw materials used)
[0088] polyamide resin (A)]
Polyamide resin (A-1): Polyamide 6 (PI01 IF, manufactured by Ube
Industries, Ltd.,.powder having an average particle size of 1 mm or less, which has
passed through a 12-mesh screen; relative viscosity: 2.22; water extraction: 0.3% by
mass; specific gravity: 1.14)
Polyamide resin (A-2): Polyarnide 6 (P1022, manufactured by Ube
Industries, Ltd., powder having an average particle size of 1 mm or less, which has
passed through a 12-mesh screen; relative viscosity: 3.36; water extraction: 0.2% by
mass; specific gravity: I. 14)
[0089]plake graphite (B)]
Graphite (B-I): Flake graphite (SP-10, manufactured by Nippon Graphite
Industries, Ltd.; average particle size: 20 jm; bulk specific gravity: 0.2 glcc; fixed
carbon content: 99% by mass; specific gravity: 2.23)
Graphite (B-2): Spherical graphite &B-BG, manufactured by Nippon
Graphite Industries, Ltd.; average particle size: 30 pm; bulk specific gravity: 0.6 glcc;
fixed carbon content: 99% by mass; specific gravity: 2.23)
[0090][Carbon fibers (C)]
Carbon fibers ((2-1): PAN carbon fibers (TR06NEB3E, manufactured by
Mitsubishi Rayon Co., Ltd.; fiber diameter: 7 prn; cut fibertlength: 10 mm; specific
gravity: 1.8)
[0091][Polyhydric alcohol @)I
Polyhydric alcohol @-1): Pentaerythritol (manufactured by The Nippon
Synthetic Chemical Industry Co., Ltd.; melting temperature: 260°C; specific gravity:
1.4)
[0092](Evaluation methods)
(1) Kneading properties
In producing a polyamide resin composition using TEX44, which is a corotation
twin-screw extruder, manufactured by The Japan Steel Works, Ltd., and
which has a diameter of 44 mm@ and an LID of 35, under kneading conditions such
that the preset temperature was 290°C, the screw speed was 200 rpm, and the
discharge rate was 20 kglhr, kneading properties were evaluated in accordance with
the following criteria 0 and x.
x: The strand discharged fiom the kneader is brittle, and the strand is cut, so
that the pelletization cannot be continuously performed for one hour or more.
Alternatively, the load in kneading is as large as more than 150 A which is the upper
limit of the allowable current load of the kneader.
0: The pelletization can be continuously performed for one hour or more,
and further the load in kneading is not more than 150 A.
(2) Thermal conduction properties
Thermal conduction properties were measured in accordance with JIS R-
261 6 (non-steady hot wire probe method).
The thermal conduction properties were evaluated in accordance with the
following criteria @, 0, A, and x.
x: Less than 4 W1m.K
A: 4 To less than 7 W/m.K
0: 7 To less than 10 W1m.K
0: 10 W1m.K or more
(3) Tensile strength
A tensile strength was measured in accordance with ASTM D-638.
The tensile strength was evaluated in accordance with the following criteria
0 and x. -.- .- .., . h e . ,
0: The tensile strength is 50 MPa or more.
x: The tensile strength is less than 50 MPa.
[0093] Example 1
5 Materials, which had the weights calculated from their respective specific
gravities so that, relative to 100 parts by volume of polyamide resin (A-l)(polyamide
6 PI01 IF, manufactured by Ube Industries, Ltd.), the amount of graphite (B-l)(flake
graphite SP-10, manufactured by Nippon Graphite Industries, Ltd.) was 90 parts by
volume, the amount of carbon fibers (C-l)(PAN carbon fibers TR06NEB3E,
10 manufactured by Mitsubishi Rayon Co., Ltd.) was 10 parts by volume, and the amount
of polyhydric alcohol (D-l)(pentaerythritol, manufactured by The Nippon Synthetic
Chemical Industry Co., Ltd.) was 1 part by volume, were charged into a cylinder
mixer and mixed with one another. The resultant mixture was introduced into a
kneader TEX44, manufactured by The Japan Steel Works, Ltd., and melt-kneaded at a
15 preset temperature of 290°C, a screw speed of 200 rpm, and a discharge rate of 20
kglhr, and extruded into a strand form, and cooled in a water bath, and then pellets of
a polyamide resin composition were obtained using a pelletizer. The kneading
properties were evaluated when producing the polyamide resin composition. The
obtained pellets of polyamide resin composition were subjected to injection molding
20 under conditions such that the cylinder temperature was 290°C, the mold temperature
was 80°C, and the cooling time was 20 seconds to prepare a 150 mm x 150 mm x 3
mm test specimen for measurement of a thermal conductivity and an ASTM No. 1
dumbbell specimen having a thickness of 3.2 mm for measurement of a tensile
strength. Using the prepared specimens, thermal conduction properties and tensile
25 strength were evaluated. The results are shown in Table 1.
[0094] Example 2
Pellets of a polyamide resin composition were produced in substantially the
same manner as in Example 1 except that the amount of graphite (B-l)(flake graphite
SP-10, manufactured by Nippon Graphite Industries, Ltd.) was changed to 80 parts by
30 volume, and they were evaluated. The results are shown in Table 1.
[0095] Example 3
Pellets of a polyamide resin composition were produced in substantially the
same manner as in Example 1 except that the amount of graphite (B-l)(flake graphite
SP-10, manufactured by Nippon Graphite Industries, Ltd.) was changed to 80 parts by
35 volume, and that the amount of carbon fibers (C-l)(PAN carbon fibers TR06NEB3EY
manufactured by 'Mitsubishi Rayon Co., Ltd.j wag changed to-24 parts by volume, h d
they were evaluated. The results are shown in Table 1.
[0096j Example 4
Pellets of a polyamide resin composition were produced in substantially the
same manner as in Example 1 except that polyamide resin (A-l)(polyamide 6 PI 01 IF,
manufactured by Ube Industries, Ltd.) was changed to polyamide resin (A-2):
polyamide 6 (P1022, manufactured by Ube Industries, Ltd.), and they were evaluated.
The results are shown in Table 1.
[0097] Comparative Example 1
Pellets of a polyamide resin composition were produced in substantially the
same manner as in Example 1 except that, relative to 100 parts by volume of
polyamide resin (A- l)(polyamide 6 P 10 1 IF, manufactured by Ube Industries, Ltd.),
the amount of graphite (B-l)(flake graphite SP-10, manufactured by Nippon Graphite
Industries, Ltd.) was changed to 100 parts by volume and the amount of carbon fibers
(C-l)(PAN carbon fibers TR06NEB3E, manufactured by Mitsubishi Rayon Co., Ltd.)
was zero and they were mixed together using a cylinder mixer, and they were
evaluated. The results are shown in Table 1.
[0098] Comparative Example 2
Pellets of a polyamide resin composition were produced in substantially the
same manner as in Comparative Example 1 except that the amount of graphite (Bl)(
flake graphite SP-10, manufactured by Nippon Graphite Industries, Ltd.) was
changed to 80 parts by volume, and they were evaluated. The results are shown in
Table 1.
[0099] Comparative Example 3
Pellets of a polyamide resin composition were produced in substantially the
same manner as in Comparative Example 1 except that graphite (B-l)(flake graphite
SP-10, manufactured by Mppo; Graphite Industries, Ltd.) was changed to graphite
(B-2)(spherical graphite LB-BG, manufactured by Nippon Graphite Industries, Ltd.),
and they were evaluated. The results are shown in Table 1.
101 001 Comparative Example 4
Pellets of a polyamide resin composition were produced in substantially the
same manner as in Comparative Example 1 except that 80 parts by volume of graphite
(B-l)(flake graphite SP-10, manufactured by Nippon Graphite Industries, Ltd.) was
changed to 100 parts by volume of carbon fibers (C-l)(PAN carbon fibers
TR06NEB3E, manufactured by Mitsubishi Rayon Co., Ltd.), and they were evaluated.
The results are shown in Table 1.
[0101] Comparative Example 5 . .
- 28 -
Pellets of a polyamide resin composition were produced in substantially the
same manner as in Example 1 except that polyhydric alcohol (D-l)(pentaerythritol,
manufactured by The Nippon Synthetic Chemical Industry Co., Ltd.) was not mixed,
and they were evaluated. The results are shown in Table 1.
5 [O 1 021 comp&ative Example 6
Pellets of a polyamide resin composition were produced in substantially the
same manner as in Example 1 except that the amount of graphite (B-l)(flake graphite
SP-10, manufactured by Nippon Graphite Industries, Ltd.) was changed to 60 parts by
volume, and that the amount of carbon fibers (C-l)(PAN carbon fibers TROGNEB3E,
10 manufactured by Mitsubishi Rayon Co., Ltd.) was changed to 40 parts by volume, and
they were evaluated. The results are shown in Table 1.
[O 1 031 Comparative Example 7
Pellets of a polyamide resin composition were produced in substantially the
same manner as in Example 1 except that the amount of carbon fibers (B-l)(flake
15 graphite SP-10, manufactured by Nippon Graphite Industries, Ltd.) was changed to 46
parts by volume, and the amount of carbon fibers (Gl)(PAN carbon fibers
TR06NEB3EY manufactured by Mitsubishi Rayon Co., Ltd.) was changed to 8 parts
by volume, and they were evaluated. The results are shown in Table 1.
[O 1 041 Comparative Example 8
20 Pellets of a polyamide resin composition were produced in substantially the
same manner as in Comparative Example 1 except that the amount of carbon fibers
(B-l)(PAN carbon fibers TR06NEB3E, manufactured by Mitsubishi Rayon Co., Ltd.)
was changed to 54 parts by volume, and they were evaluated. The results are shown
in Table I.
25 [0105] [Table 11
[0106]
(Evaluation methods)
(1) Relative viscosity
A relative viscosity was measured at 25OC using an Ostwald viscometer
with respect to a solution using 96% by mass sulfuric acid as a solvent and having a
polyamide resin concentration of 1.0 gldl.
(2) Melting temperature (Tm)
A melting temperature (Tm) was measured using PYFUS Diamond DSC,
manufactured by PerkinElmer Co., Ltd., in a nitrogen gas atmosphere. The
endothermic peak ternperature obtained in the measurement was taken as a melting
ternperature.
(3) Electrical insulating properties
Electrical insulating properties were measured in accordance with ASTM D-
(4) Thermal conduction properties
Thermal conduction properties were measured in accordance with JIS R-
261 6 (non-steady hot wire probe method).
(5) Tensile strength
A tensile strength was measured in accordance with ASTM D-638.
[0107) (Raw materials used)
[Polyamide resin (A I )I
5 Polyamide resin (A1 -1): Polyamide 92
28.18 kg (139.3 mol) of dibutyl oxalate was charged into a pressure vessel
having an internal volume of 150 litters and having a stirrer, a thermometer, a torque
meter, a pressure gauge, a raw material inlet directly connected to a diaphragm pump,
10 a nitrogen gas feed inlet, a vent port, a pressure regulator, and a polymer withdrawal
outlet, and futher the inside of the pressure vessel was pressurized with nitrogen gas
having a purity of 99.9999% to 0.5 MPa, and then nitrogen gas was released until the
pressure became atmospheric pressure, and this operation was repeated 5 times to
purge the vessel with nitrogen, and then the temperature in the system was increased
15 under a pressure while stirring. The temperature of dibutyl oxalate was increased to
100°C over about 30 minutes, and then a mixture of 18.74 kg (1 18.4 mol) of 1,9-
nonamethylenediamine and 3.3 1 kg (20.9 mol) of 2-methyl-1,s-octanedimine (1,9-
nonamethylenediamine:2-methyl-1,8-octanedimhe molar ratio is 85: 15) was fed to
the reaction vessel at a flow rate of 1.49 litter/minute using the diaphragm pump over
20 about 17 minutes and the temperature was increased simultaneously with the feeding.
Immediately after the feeding, the internal pressure of the pressure vessel was
increased to 0.35 MPa due to butanol formed by a condensation polymerization
reaction, and the temperature of the condensation polymerization product was
increased to about 170°C. Then, the temperature was increased to 235OC over one
25 hour. During the temperature increase, the internal pressure was adjusted to 0.5 MPa
while withdrawing the formed butanol from the vent port. Immediately after the
temperature of the condensation polymerization product reached 235"C, butanol was
withdrawn from the vent port over about 20 minutes so that the internal pressure
became 0.11 MPa (atmospheric pressure). At a point in time when the internal
30 pressure became atmospheric pressure, the temperature increase was started while
flowing nitrogen gas at 1.5 litterfminute, and the temperature of the condensation
polymerization product was increased to 260°C over about one hour, and a reaction
was conducted at 260°C for 4.5 hours. Then, stirring was stopped and the inside of
the system was pressurized with nitrogen to 1 MPa and allowed to stand for about 10
35 minutes, and then vented until the internal pressure became 0.5 MPa, and the resultant
condensation palymerization product was withdrawn in a strand form from the
withdrawal outlet at the lower portion of the pressure vessel. The polymerization
product in a strand form was immediately cooled with water, and the cooled resin in a
strand form was pelletized by means of a pelletizer, obtaining polyamide resin (All)(
polyamide 92) in which the amount of the oxalic acid units is 100 mol%, based on
the total mole of the dicarboxylic acid units. The obtained pellets were frozen with
liquid nitrogen, and ground using a pin mill, and then a powder having an average
particle size of 1 mm or less, which had passed through a 16-mesh screen, was
obtained. The obtained polyamide resin (Al-1) had a relative viscosity of 2.76 and a
melting temperature of 230°C.
Polyamide resin (A- 1): Powdery polyamide 6 (PI01 1 F, manufactured by
Ube Industries, Ltd.; relative viscosity: 2.22)
[0108] [At least one member selected from the group consisting of metal oxide
(Bl), nitrogen compound (B2), and silicon compound (B3)]
Metal oxide (Ell)
Metal oxide 1 1 ) : Particulate magnesium oxide (RFJO-SC,
manufactured by Ube Material Industries, Ltd.; average particle size: 63 pm; purity:
98% by weight; apparent specific gravity: 1.5 &m3; specific surface area: 0.1 dg)
[O 1 091 Example 5
100 Paxts by mass of polyamide resin (Al-l)(polyamide 92) and 213 parts
by mass of metal oxide (Bl-l)(magnesium oxide, manufactured by Ube Material
Industries, Ltd.) were mixed with each other by means of a cylinder mixer. The
resultant mixture was melt-kneaded at a preset temperature of 280°C using a twinscrew
extruder having a cylinder diameter of 44 mm and an LID of 35, and extruded
into a strand form, and cooled in a water bath, and then pellets of a polyamide resin
composition were obtained using a pelletizer. The obtained polyamide resin
composition was subjected to injection molding under conditions such that the
cylinder temperature was 290°C, the mold temperature was 80°C, and the cooling
time was 20 seconds to prepare a 150 rnm x 150 mm x 3 rnrn test specimen for
measurement of a thermal conductivity and a volume resistivity and an ASTM No. 1
dumbbell specimen having a thickness of 3.2 mm for measurement of a tensile
strength. The obtained specimens were subjected to treatment in a thermostatic
chamber under conditions at a temperature of 85°C and at a relative humidity of
85%W for 72 hours, and a thermal conductivity, a volume resistivity, and a tensile
strength were measured with respect to the above-treated specimens and the untreated
specimens. Tlie results of the evaluation are shown in Table 2.-
[O 1 101 Example 6
Substantially the same procedure as in Example 5 was conducted except that
the amount of metal oxide (Bl-l)(magnesium oxide, manufactured by Ube Material
Industries, Ltd.) was changed to 133 parts by mass. The results of the evaluation are
5 shown in Table 2.
[O 1 1 11 Comparative Example 9
Substantially the same procedure as in Example 5 was conducted except that
polyamide resin (Al-l)(polyamide 92) was changed to polyamide resin (Al)@
olyamide 6, manufactured by Ube Industries, Ltd.). The results of the evaluation
10 are shown in Table 2.
[O 1 121 Comparative Example 1 0
Substantially the same procedure as in Example 6 was conducted except that
polyamide resin (Al-l)(polyamide 92) was changed to polyamide resin (Al)(
polyamide 6, manufactured by Ube Industries, Ltd.). The results of the evaluation
1 5 are shown in Table 2.
[O 1 13 j [Table 21
[0114] In Examples 5 and 6, which correspond to polyamide resin composition B
of the present invention, as can be clearly seen from Table 2, the lowering of the
20 volume resistivity indicating electrical insulating properties and the tensile strength
indicating mechanical strength due to the high-temperature and high-humidity
treatment is suppressed, and the polyamide resin composition can exhibit excellent
electrical insulating properties and thermal conduction 'properties as well as
Polyamide resin (Al)
Parts by mass
At least one member selected from
the group consisting of metal oxide
(Bl), nitrogen compound (B2), and
silicon compound (B3)
Metal oxide (l3 1)
Parts by mass
Example 5
(Al-1)
100
(B1-1)
213
1.17
1.15
6. 1 X 1 0 ' 9 . 4
5. 0 X 10"
70
6 6
Thermal conductivity
[W/mKl
Volume resistivity
[ ia cm]
Tensile strength
[MF'al
Before treatment
After treatment
Before treatment
Aftertreatment
Before treatment
After treatment
Example 6
(Al-1)
100
(Bl-I)
133
0.85
0.88
X 10"
3. 0 X 10"
72
68
Com~arative
Example 9
(A-1)
100
( B l - 1 )
213
1. 23
1.27
4. 5 X 10"
1.2 X 10"
65
31
Com~mtive
Example 10
(A-1)
100
( B l - 1 )
133
0.89
0.97
1. 2 X 10"
7. 2X 10''
67
31
mechanical strength even under high-temperature and high-humidity conditions, and
exhibits especially excellent electrical insulating properties after a high-temperature
and high-humidity treatment, and hence can be preferably used as an electrical
insulating material in an electrical insulating part.
[0115]
(Raw materials used)
[Polyamide resin (A)]
Polyamide resin (A-1): Polyamide 6 (PI01 IF, manufactured by Ube
Industries, Ltd., powder having an average particle size of 1 mm or less, which has
passed through a 12-mesh screen; relative viscosity: 2.22; water extraction: 0.3% by
mass; specific gravity: 1.14)
[O 1 163 [Metal oxide particles (BB)]
Magnesium oxide (BB-I): Magnesium oxide (RF-70C-SC, manufactured
by Ube Material Industries, Ltci.; average particle size: 7 p; purity: 99%)
Magnesium oxide (BB-2): Magnesium oxide (RF-50-SC, manufactured by.
Ube Material Industries, Ltd.; average particle size: 53 pm; purity: 98%)
Magnesium oxide @B-3): Magnesium oxide (RF-1 OC-SC, manufactured
by Ube Material Industries, Ltd.; average particle size: 72 p; purity: 99%)
[0117] [Polyhydric alcohol (D)]
Pentaerythritol (D-l)(manufactured by The Nippon Synthetic Chemical
Industry Co., Ltd.; melting temperature: 260°C; specific gravity: 1.4)
(Evaluation methods)
(1) Kneading properties
Kneading properties were tested and evaluated in the same manner as in
polyamide resin composition A.
(2) Thermal conduction properties
Thermal conduction properties were measured in accordance with JIS R-
261 6 (non-steady hot wire probe method).
A test piece of 150 mm x 150 mm x 3 mrnt was used, and measurement was
made with respect to three locations. The location of measurement near the gate
shown in Fig. 1 was indicated by character A, and the middle portion was indicated by
character B, and the end portion was indicated by character C.
= . The thermal conductivity difference was obtained -as.a difference between . .
the maximum and minimum of the thermal conductivities measured in the three
locations.
[O 1 1 81 Example 7
Polyamide resin (A-1) PI01 IF, manufactured by Ube Industries, Ltd., in an
amount of 23.2% by mass, magnesium oxide (BB-I) RF-70C-SC, manufactured by
Ube Material Industries, Ltd., in an amount of 7.6% by mass, magnesium oxide (BB-
2) RF-50-SC, manufactured by Ube Material Industries, Ltd., in an amount of 37.9%
by mass, magnesium oxide (BB-3) RF-1OC-SC, manufactured by Ube Material
Industries, Ltd., in an amount of 30.3% by mass, and pentaerythritol @-I) in an
amount of 1 .O% by mass were mixed together.
With respect to the particle size of magnesium oxide, particle size
distributions of magnesium oxide (BB-I), magnesium oxide (BB-2), and magnesium
oxide (BB-3) were measured by a laser diffraction scattering method in accordance
with JIS R 1629, and, from the results of the particle size distributions, the amounts of
the magnesium oxide having a particle size of 20 pm or less and the magnesium oxide
having a particle size of 70 p or more, based on the total mass of the magnesium
oxide, were determined.
The magnesium oxide incorporated had an average particle size of 37 pm,
and the amount of the magnesium oxide having a particle size of 70 pm or more was
15% by mass and the amount of the magnesium oxide having a particle size of 20 pn
or less was 41% by mass. (The amount of the magnesium oxide having a particle
size 2 times or more the average particle size was 11% by mass, and the amount of the
magnesium oxide having a particle size half or less of the average particle size was
4 1 % by mass.)
These were charged into a cylinder mixer and mixed with one another, and
the resultant mixture was introduced into a kneader T.EX44, manufactured by The
Japan Steel Works, Ltd., and melt-kneaded at a preset temperature of 290°C, a screw
speed of 200 rpm, and a discharge rate of 20 Kg/hr, and kneading properties were
evaluated during the melt-kneading. The obtained pellets of polyamide resin
composition were subjected to injection molding under conditions such that the
cylinder temperature was 290°C, the mold temperature was 80°C, and the cooling
time was 20 seconds to prepare a 150 rnm x 150 mm x 3 mm test specimen for
measurement of a thermal conductivity. Using the prepared specimen, thermal
conduction properties were evaluated with respect to measurement locations A, B, and
C. The results are shown in Table 3.
[O 1 191 Example 8 _., _
Pellets of a polyamide resin composition were produced in substantially the
same manner as in Example 7 except that the amount of magnesium oxide @B-1) RF-
70C-SC, manufactured by Ube Material Industries, Ltd., was changed to 30.3% by
mass, that the amount of magnesium oxide (BB-2) RF-50-SC, manufactured by Ube
Material Industries, Ltd., was 37.9% by mass, and that the amount of magnesium
oxide (BB-3) RF-1OC-SC, manufactured by Ube Material Industries, Ltd., was
changed to 7.6% by mass, and they were evaluated. The results are shown in Table 3.
The magnesium oxide incorporated has an average particle size of 52 pm,
and the amount of the magnesium oxide having a particle size of 70 pm or more is
30% by mass and the amount of the magnesium oxide having a particle size of 20 pm
or less is 21% by mass, based on the total mass of the magnesium oxide incorporated.
(The amount of the magnesium oxide having a particle size 2 times or more the
average particle size is 15% by mass, and the amount of the magnesium oxide having
a particle size half or less of the average particle size is 24% by mass.)
[O 1201 Example 9
Pellets of a polyamide resin composition were produced in substantially the
same manner as in Example 7 except that the amount of magnesium oxide @B-1) RF-
70C-SC, manufactured by Ube Material Industries, Ltd., was changed to 15.2% by
mass, that the amount of magnesium oxide (BB-2) RF-50-SC, manufactured by Ube
Material Industries, Ltd., was changed to 45.5% by mass, and that the amount of
magnesium oxide (BB-3) RF-1OC-SC, manufactured by Ube Material Industries, Ltd.,
was changed to 15.2% by mass, and they were evaluated. The results are shown in
Table 3.
The magnesium oxide incorporated has an average particle size of 48 pm,
and the amount of the magnesium oxide having a particle size of 70 pm or more is
22% by mass and the amount of the magnesium oxide having a particle size of 20 pn
or less is 25% by mass, based on the total mass of the magnesium oxide mixed. (The
amount of the magnesium oxide having a particle size 2 times or more the average
particle size is 10% by mass, and the amount of the magnesium oxide having a
particle size half or less of the average particle size is 26% by mass.)
[O 1211 Comparative Example 1 1
Pellets of a polyamide resin composition were produced in substantially the
same manner as in Example 7 except that polyamide resin (A-1) PlOlIF,
manufactured by Ube Industries, Ltd., in an amount of 23.2%, magnesium oxide (BB-
2) W-50-SC, manufactured by Ube Material Industries, Ltd., in an amount of 75.9%
by mass, and pedfiierythritol (D-1) in m amount of 9 .O% by m8ss were mixed together,
and they were evaluated. The results are shown in Table 3.
The magnesium oxide mixed has an average particle size of 52 pm, and the
amount of the magnesium oxide having a particle size of 70 pm or more is 20% by
mass and the amount of the magnesium oxide having a particle size of 20 pm or less is
0.0% by mass, based on the total mass of the magnesium oxide mixed. (The amount
of the magnesium oxide having a particle size 2 times or more the average particle
size is 2% by mass, and the amount of the magnesium oxide having a particle size half
or less of the average particle size is 1% by mass.)
[0 1221 Comparative Example 12
Pellets of a polyamide resin composition were produced in substantially the
same manner as in Example 7 except that polyamide resin (A-1) PI01 IF,
manufactured by Ube Industries, Ltd., in an amount of 23.2%, magnesium oxide (BB-
2) RF-50-SC, manufactured by Ube Material Industries, Ltd., in an amount of 30.3%
by mass, magnesium oxide (BB-3) RF-1OC-SC, manufactured by Ube Material
Industries, Ltd., in an amount of 45.5% by mass, and pentaerythritol (D-1) in an
amount of 1 .O% by mass were mixed together, and they were evaluated. The results
are shown in Table 3.
The magnesium oxide mixed has an average particle size of 1 1 pm, and the
amount of the magnesium oxide having a particle size of 70 pn or more is 8% by
mass and the amount of the magnesium oxide having a particle size of 20 p or less is
56% by mass, based on the total mass of the magnesium oxide mixed. (The amount
of the magnesium oxide having a particle size 2 times or more the average particle
size is 42% by mass, and the amount of the magnesium oxide having a particle size
half or less of the average particle size is 25% by mass.)
[O 1231 Comparative Example 13
Pellets of a polyamide resin composition were produced in substantially the
same manner as in Example 7 except that the amount of polyamide resin (A-1)
PlOllF, manufactured by Ube Industries, Ltd., was changed to 24.2%, that the
amount of magnesium oxide (BB-1) RF-70-SC, manufactured by Ube Material
Industries, Ltd., was changed to 30.3% by mass, that the amount of magnesium oxide
(BB-2) RF-50-SC, manufactured by Ube Material Industries, Ltd., was 37.9% by mass,
and that the amount of magnesium oxide (BB-3) W-1OC-SC, manufactured by Ube
Material Industries, Ltd., was changed to 7.6% by mass, and they were evaluated.
The results are shown in Table 3.
The magnesium oxide mixed has an average particle size of 52 pm, and the
amount of the magnesium oxide having-a particle size of 70 .pmar more is 30.0% by
mass and the amount of the magnesium oxide having a particle size of 20 pm or less is
21.0% by mass, based on the total mass of the magnesium oxide mixed. (The
amount of the magnesium oxide having a particle size 2 times or more the average
particle'size is 15% by mass, and the amount of the magnesium oxide having a
5 particle size half or less of the average particle size is 24% by mass.)
[O 1241 Comparative Example 14
Substantially the same procedure for production as in Example 7 was
conducted except that the amount of magnesium oxide (BB-1) RF-70-SC,
manufactured by Ube Material Industries, Ltd., was changed to 75.9% by mass, and
10 that the amounts of magnesium oxide (BB-2) RF-50-SC, manufactured by Ube
Material Industries, Ltd., and magnesium oxide (BB-3) RF-1OC-SC, manufactured by
Ube Material Industries, Ltd., were changed to 0% by mass. However, the mixture
could not be kneaded under good conditions, making it impossible to obtain pellets of
a polyamide resin composition.
15 The magnesium oxide mixed has an average particle size of 74 pm, and the
amount of the magnesium oxide having a particle size of 70 pm or more is 52.0% by
mass and the amount of the magnesium oxide having a particle size of 20 pm or less is
30.0% by mass, based on the total mass of the magnesium oxide mixed. (The
amount of the magnesium oxide having a particle size 2 times or more the average
20 particle size is 16% by mass, and the amount of the magnesium oxide having a
particle size half or less of the average particle size is 37% by mass.)
[0125 ] [Table 33
INDUSTRIAL APPLICABILITY
[0126] In the present invention, there can be provided a polyarnide resin
composition which is advantageous in that a molded article having excellent
5 mechanical properties or electrical insulating properties and excellent thennal
conduction properties can be obtained. Therefore, the molded article can be used in
various types of molded articles in which a molded product of a polyamide resin
composition has conventionally been used, and a wide variety of applications, such as
sheets, films, pipes, tubes, monofilaments, fibers, automobiles, computers and
10 associated devices, optical devices, information and communication devices, electric
and electronic device parts for precision devices, civil engineering and construction
products, medical products, and household products. The molded article is
especially usefbl in applications of electric and electronic device parts, which require
not only the inherent properties of the polyamide resin but also thermal conduction
I 5 properties.

CLAIMS
1. A polyamide resin composition comprising a polyamide resin (A) and a
property imparting component, the composition being:
5 (1) a polyamide resin composition which comprises, relative to 100 parts by
volume of the polyamide resin (A), as the property imparting component, 50 to less
than 100 parts by volume of flake graphite (B), 5 to 40 parts by volume of carbon
fibers (C), and 0.1 to 5 parts by volume of a polyhydric alcohol @);
(2) a polyamide resin composition which comprises the polyamide resin (A)
10 which is a polyamide resin (Al) comprising dicarboxylic acid units (x) and diamine
units (y) as constitutional units, and the property imparting component which is at
least one member selected fiom the group consisting of a metal oxide (Bl), a nitrogen
compound (B2), ahd a silicon compound (B3), wherein the dicarboxylic acid units (x)
of the polyamide resin (Al) are oxalic acid in an amount of 70 mol% or more, based
15 on the total dicarboxylic acid units of the polyamide resin (Al); or
(3) a polyamide resin composition which comprises the polyamide resin (A)
and metal oxide particles (BB) as the property imparting component, wherein the
metal oxide particles (BB) contain those having a particle size of 70 pm or more in an
mount of 10 to 50% by mass and those having a particle size of 20 pm or less in an
20 amount of 1 to 50% by mass, based on the total mass of the metal oxide particles,
wherein the metal oxide particles (BB) are contained in an amount of 70 to 85% by
mass, based on the mass of the polyamide resin composition.
2. The polyamide resin composition according to claim 1, which comprises,
25 relative to 100 parts by volume of the polyamide resin (A), 50 to less than 100 parts
by volume of the flake graphite (B), 5 to 40 parts by volume of the carbon fibers (C),
and 0.1 to 5 parts by volume of the polyhydric alcohol (D).
3. The polyamide resin composition according to claim 2, wherein the
30 polyhydric alcohol @) is a polyhydric alcohol having a melting temperature of 150 to
280°C.
4. The polyamide resin composition according to claim 2 or 3, which is
obtainable by melt-kneading.
35
5. The polyamide resin composition according to claim 1, which comprises the
polyarnide resin (Al) comprising dicarbosylic acid units (s) and diamine units (y) as
constitutional units, and at least one member selected from the group consisting of a
metal oxide (Bl), a nitrogen compound (B2), and a silicon compound (B3), wherein
the dicarboxylic acid units (s) of the polyamide resin (Al) are osalic acid in an
5 amount of 70 mol% or more, based on the total dicarbosylic acid units of the
polyarnide resin (Al).
6. The polyarnide resin composition according to claim 5. wherein the metal
oside (Bl) is magnesium oxide.
10
7. The polyarnide resin composition according to claim 5 or 6, which is for use
in an electrical insulating part.
8. The polyamide resin composition according to claim 1, which comprises the
15 polyamide resin (A) and the metal oside particles (BB), wherein the metal oside
particles (BB) contain those having a particle size of 70 pm or more in an amount of
10 to 50% by mass and those having a particle size of 20 pm or less in an amount of 1
to 50% by mass, based on the total mass of the metal oside particles, wherein the
metal oside particles (BB) are contained in an amount of 70 to 85% by mass, based on
20 the mass of the polyamide resin composition.
9. The polyamide resin composition according to claim 8, which further
comprises the polyhydric alcohol (D) in an amount of 0.1 to 5% by mass, based on the
mass of the polyamide resin composition.
2 5
10. The polyamide resin composition according to claim 8 or 9. wherein the
metal oxide particIes (BB) are magnesium oside.
11. A molded article comprising the polyamide resin composition according to
30 anyoneofclaims1to10.
Dated this llthd ay of April 2013
Of Anand anb Annnd Advocates
Agent for the Applicant