FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
[See section 10, Rule 13]
POLYURETHANE RESIN COMPOSITION;
SANYU REC CO., LTD., A CORPORATION ORGANIZED AND EXISTING
UNDER THE LAWS OF JAPAN, WHOSE ADDRESS IS 5-1, DOU-CHO 3-CHOME,
TAKATSUKI-SHI, OSAKA 5698558, JAPAN
THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE
INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED.
2
Description
Technical Field
[0001]
The present invention relates to a polyurethane resin composition.
Background Art
[0002]
Recent advances in electronic circuit substrates and electronic components
have increased the stress on materials due to heating and cooling cycles, and there is a
need for a material having high heat resistance and capable of retaining heat
dissipation properties over a long term.
[0003]
Polyurethane resins, which are used for sealing these components, are
disadvantageous in that they lose flexibility due to long-term heating and cooling
cycles, and develop cracks. Thus, there is an urgent need for the development of a
material in which the temperature dependence of elastic modulus can be further
reduced, and the reduced temperature dependence of elastic modulus can be retained
over a long term.
[0004]
For example, Patent Literatures 1 to 3 disclose using a polybutadiene polyol
having a hydroxyl value of 20 to 120 mg KOH/g. These literatures, however, fail to
specifically disclose a polyurethane resin obtained using a polybutadiene polyol
having a hydroxyl value of 60 mg KOH/g or less, and teach that it is preferred to use a
polybutadiene polyol having a hydroxyl value of 100 mg KOH/g or more (for example,
Poly bd (registered trademark) R-15HT) as a polyol compound.
Citation List
Patent Literatures
[0005]
3
Patent Literature 1: JP 2016-020439 A
Patent Literature 2: JP 2015-131883 A
Patent Literature 3: JP 2015-089944 A
Summary of Invention
Technical Problem
[0006]
It is an object of the present invention to provide a polyurethane resin having
an appropriate hardness, and excellent in compatibility, workability, elongation,
elastic modulus (elastic modulus at 40C ((10Hz)), and volume resistivity, and
having an excellent heating and cooling cycle characteristic (change in elastic
modulus from 40 to 120C), by using a polybutadiene polyol having a hydroxyl
value of 60 mg KOH/g or less.
Solution to Problem
[0007]
The present inventors have conducted extensive research to solve the
aforementioned problem, and found that the problem can be solved by a polyurethane
resin composition in which a polyol compound includes a polybutadiene polyol
having a hydroxyl value of 60 mg KOH/g or less, and an inorganic filler is contained
in an amount of 50 to 85% by mass, and a plasticizer is contained in an amount of 1 to
30% by mass, based on 100% by mass of the polyurethane resin composition. The
present invention has been completed based on this finding.
[0008]
In summary, the present invention relates to a polyurethane resin composition,
a sealing material, an electrical or electronic component, and so on, as given below:
[0009]
Item 1.
A polyurethane resin composition comprising (A) a polyisocyanate compound,
4
(B) a polyol compound, (C) an inorganic filler, and (D) a plasticizer, wherein
the polyol compound (B) includes (b1) a polybutadiene polyol having a
hydroxyl value of 60 mg KOH/g or less, and
the inorganic filler (C) is contained in an amount of 50 to 85% by mass, and
the plasticizer (D) is contained in an amount of 1 to 30% by mass, based on 100% by
mass of the polyurethane resin composition.
Item 2.
The polyurethane resin composition according to item 1, wherein a change in
elastic modulus ([elastic modulus at 40C]  [elastic modulus at 120C]) is 40 MPa
or less.
Item 3.
The polyurethane resin composition according to item 1 or 2, wherein the
change in elastic modulus ([elastic modulus at 40C]  [elastic modulus at 120C]) is
30 MPa or less.
Item 4.
The polyurethane resin composition according to any one of items 1 to 3,
wherein the polyisocyanate compound (A) is an isocyanurate of an aliphatic
polyisocyanate compound, a cycloaliphatic polyisocyanate, and/or an aromatic
polyisocyanate.
Item 5.
The polyurethane resin composition according to any one of items 1 to 4,
wherein the polybutadiene polyol (b1) having a hydroxyl value of 60 mg KOH/g or
less is contained in an amount of 5 to 15% by mass, based on 100% by mass of the
polyurethane resin composition.
Item 6.
The polyurethane resin composition according to any one of items 1 to 5,
wherein the polyol compound (B) does not include castor oil or a castor oil-based
polyol.
Item 7.
5
The polyurethane resin composition according to any one of items 1 to 6,
wherein the plasticizer (D) does not include an ester compound represented by general
formula (1):
wherein R1 and R2 each independently represent a C6-12 alkyl group; X
represents a C3-8 alkylene group; and a and b each independently represent an integer
from 2 to 10, with the proviso that a sum of a and b is 4 to 20.
Item 8.
The polyurethane resin composition according to any one of items 1 to 7,
wherein the polybutadiene polyol (b1) has a number average molecular weight (Mn)
of 100 to 5000.
Item 9.
The polyurethane resin composition according to any one of items 1 to 8,
wherein the polybutadiene polyol (b1) has a viscosity (30C) of 0.01 to 100 Pas.
Item 10.
The polyurethane resin composition according to any one of items 1 to 9,
wherein the composition has a volume resistivity of 1  1012 cm or more.
Item 11.
The polyurethane resin composition according to any one of items 1 to 10,
wherein the composition has an elastic modulus at 40C (10 Hz) of 40 MPa or less.
Item 12.
The polyurethane resin composition according to any one of items 1 to 11,
further comprising (E) a crosslinking agent.
Item 13.
The polyurethane resin composition according to any one of items 1 to 11,
further comprising (E) a crosslinking agent (excluding castor oil).
6
Item 14.
The polyurethane resin composition according to item 12 or 13, wherein the
crosslinking agent (E) is (E1) an aromatic alcohol-based crosslinking agent and/or
(E2) an aliphatic alcohol-based crosslinking agent.
Item 15.
The polyurethane resin composition according to any one of items 12 to 14,
wherein the crosslinking agent (E) is the aromatic alcohol-based crosslinking agent
(E1).
Item 16.
The polyurethane resin composition according to any one of items 12 to 15,
wherein the crosslinking agent (E) is a crosslinking agent having a number average
molecular weight of 400 or less.
Item 17.
The polyurethane resin composition according to any one of items 1 to 16,
wherein the plasticizer (D) includes (d1) an adipic acid-based plasticizer and/or (d2) a
phthalic acid-based plasticizer.
Item 18.
The polyurethane resin composition according to any one of items 1 to 17,
wherein the plasticizer (D) is the adipic acid-based plasticizer (d1).
Item 19.
The polyurethane resin composition according to any one of items 1 to 18,
wherein the plasticizer (D) is contained in an amount of 10 to 29% by mass, based on
100% by mass of the polyurethane resin composition.
Item 20.
A polyurethane resin composition comprising (A) a polyisocyanate compound,
(B) a polyol compound, (C) an inorganic filler, and (D) a plasticizer, wherein
the polyisocyanate compound (A) is an isocyanurate of an aliphatic
polyisocyanate compound, a cycloaliphatic polyisocyanate, and/or an aromatic
polyisocyanate,
7
the polyol compound (B) includes (b1) a polybutadiene polyol having a
hydroxyl value of 60 mg KOH/g or less, and
the polyol compound (B) does not include castor oil or a castor oil-based
polyol,
the plasticizer (D) does not include an ester compound represented by general
formula (1):
wherein R1 and R2 each independently represent a C6-12 alkyl group; X
represents a C3-8 alkylene group; and a and b each independently represent an integer
from 2 to 10, with the proviso that a sum of a and b is 4 to 20,
the polybutadiene polyol (b1) having a hydroxyl value of 60 mg KOH/g or
less is contained in an amount of 5 to 15% by mass, the inorganic filler (C) is
contained in an amount of 50 to 85% by mass, and the plasticizer (D) is contained in
an amount of 1 to 30% by mass, based on 100% by mass of the polyurethane resin
composition, and
a change in elastic modulus ([elastic modulus at 40C]  [elastic modulus at
120C]) is 30 MPa or less.
Item 21.
The polyurethane resin composition according to any one of items 1 to 20,
which is used for sealing an electrical or electronic component.
Item 22.
A sealing material comprising the polyurethane resin composition according
to any one of items 1 to 21.
Item 23.
An electrical or electronic component resin-sealed with the sealing material
according to item 22.
8
Advantageous Effects of Invention
[0010]
The present invention can provide a polyurethane resin composition and a
sealing material having an appropriate hardness, and excellent in compatibility,
workability, elongation, elastic modulus (elastic modulus at 40C ((10Hz)), and
volume resistivity, and having an excellent heating and cooling cycle characteristic
(change in elastic modulus from 40 to 120C).
[0011]
Specifically, the polyurethane resin composition and the sealing material of
the present invention have reduced temperature dependence of elastic modulus (120 to
40C) as a heating and cooling cycle characteristic, exhibit excellent elongation
(flexibility), and have a less change in hardness, elongation (flexibility), and elastic
modulus due to thermal degradation (after heating) (100C).
[0012]
Thus, the polyurethane resin composition and the sealing material of the
present invention can be suitably used for insulation treatment of various electrical
and electronic components, for example.
[0013]
The electrical or electronic component of the present invention is resin-sealed
with the sealing material, and thus, exhibits high reliability.
Description of Embodiments
[0014]
A polyurethane resin composition, a sealing material, and an electrical or
electronic component of the present invention will be hereinafter described in detail.
As used herein, the term "comprise", "contain", or "include" is intended to include the
concept covering "comprise", "contain", or "include", and "substantially comprising"
and "consisting of".
9
[0015]
1. Polyurethane Resin Composition
The polyurethane resin composition of the present invention is a polyurethane
resin composition comprising (A) a polyisocyanate compound, (B) a polyol compound,
(C) an inorganic filler, and (D) a plasticizer, wherein
the polyol compound (B) includes (b1) a polybutadiene polyol having a
hydroxyl value of 60 mg KOH/g or less, and
the inorganic filler (C) is contained in an amount of 50 to 85% by mass, and
the plasticizer (D) is contained in an amount of 1 to 30% by mass, based on 100% by
mass of the polyurethane resin composition.
[0016]
In the polyurethane resin composition of the present invention, a change in
elastic modulus ([elastic modulus at 40C]  [elastic modulus at 120C]) is
preferably 40 MPa or less, more preferably 30 MPa or less, and particularly preferably
20 MPa or less.
[0017]
The volume resistivity of the polyurethane resin composition of the present
invention is preferably 1  1012 cm or more, and more preferably 1  1012 cm or
more.
[0018]
The elastic modulus at 40C (10 Hz) of the polyurethane resin composition
of the present invention is preferably 40 MPa or less, more preferably 30 MPa or less,
and particularly preferably 20 MPa or less.
[0019]
1-1. Polyisocyanate Compound (A)
The "polyisocyanate compound (A)" is not limited as long as it is a compound
having two or more isocyanate groups, and may be any of such various components
that are used or may be used in polyurethane resin compositions (particularly
polyurethane resin compositions for sealing electrical and electronic components).
10
[0020]
Examples of the polyisocyanate compound (A) include, but are not limited to:
polyisocyanate compounds, such as
(A1) an aliphatic polyisocyanate compound,
(A2) an alicyclic polyisocyanate compound, and
(A3) an aromatic polyisocyanate compound;
modified products (a) of the polyisocyanate compounds (for example,
(a-1) an isocyanurate,
(a-2) a carbodiimide,
(a-3) an adduct,
(a-4) a biuret, and
(a-5) an allophanate); and
multimers (b) of the polyisocyanate compounds.
[0021]
Examples of the aliphatic polyisocyanate compound (A1) include
tetramethylene diisocyanate, dodecamethylene diisocyanate, 1,6-hexamethylene
diisocyanate (HDI), 2,2,4-trimethyl hexamethylene diisocyanate, 2,4,4-trimethyl
hexamethylene diisocyanate, lysine diisocyanate, 2-methylpentane-1,5-diisocyanate,
and 3-methylpentane-1,5-diisocyanate. 1,6-Hexamethylene diisocyanate (HDI) is
preferred.
[0022]
The aliphatic polyisocyanate compound (A1) is preferably (A1a-1) an
isocyanurate of aliphatic polyisocyanate compound. For example, an isocyanurate
compound having terminal isocyanate groups derived from 1,6-hexamethylene
diisocyanate (hereinafter abbreviated as "HDI") is used as isocyanurate-modified
1,6-hexamethylene diisocyanate for use in the present invention. Specific examples
of such compounds include DURANATE (registered trademark) TPA-100, TKA-100,
TSA-100, TSS-100, TSE-100, and TLA-100 manufactured by Asahi Kasei
Corporation; DESMODUR (registered trademark) N3390 manufactured by Sumitomo
11
Bayer Urethane Co., Ltd.; CORONATE (registered trademark) EH manufactured by
Nippon Polyurethane Industry Co., Ltd.; TAKENATE D170N manufactured by Takeda
Pharmaceutical Co., Ltd.; and BURNOCK (registered trademark) DN980
manufactured by Dainippon Ink and Chemicals, Incorporated (DIC Corporation).
[0023]
Examples of the alicyclic polyisocyanate compound (A2) include isophorone
diisocyanate, hydrogenated xylylene diisocyanate, 4,4'-dicyclohexylmethane
diisocyanate (hydrogenated 4,4'-diphenylmethane diisocyanate; HMDI),
1,4-cyclohexane diisocyanate, methylcyclohexylene diisocyanate, and
1,3-bis(isocyanatemethyl)cyclohexane.
[0024]
A polyisocyanate obtained by hydrogenating 4,4'-diphenylmethane
diisocyanate (hereinafter abbreviated as MDI) is used as hydrogenated
4,4'-diphenylmethane diisocyanate for use in the present invention. Specific
examples of such polyisocyanates include WANNATE (registered trademark) HMDI
manufactured by Wanhua Chemical (Japan) Co., Ltd.
[0025]
Examples of the aromatic polyisocyanate compound (A3) include tolylene
diisocyanate, 2,2'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate,
4,4'-diphenylmethane diisocyanate (MDI), 4,4'-dibenzyl diisocyanate, 1,5-naphtylene
diisocyanate, xylylene diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene
diisocyanate, dialkyl diphenyl methane diisocyanate, tetraalkyl diphenyl methane
diisocyanate, and , , , -tetramethyl xylylene diisocyanate. 2'-Diphenylmethane
diisocyanate, 2,4'-diphenylmethane diisocyanate, and 4,4'-diphenylmethane
diisocyanate (MDI) are preferred.
[0026]
A polyisocyanate having a carbodiimide group derived from
4,4'-diphenylmethane diisocyanate (carbodiimide-modified MDI) is used as
4,4'-diphenylmethane diisocyanate (MDI) for use in the present invention. Specific
12
examples of such polyisocyanates include MILLIONATE (registered trademark) MTL
manufactured by Tosoh Corporation.
[0027]
The viscosity of the polyisocyanate compound (A) is not limited; it will vary
greatly depending on the type of the polyisocyanate compound, whether the
polyisocyanate compound is modified or not, and the like. For example, the
aromatic polyisocyanate compound, and a modified product and a multimer thereof
(preferably a carbodiimide and a multimer of the aromatic polyisocyanate compound)
have a viscosity at 25C of, for example, 5 to 200 mPas, preferably 10 to 150 mPas,
more preferably 15 to 100 mPas, and still more preferably 20 to 80 mPas. As an
alternative example, the aliphatic polyisocyanate compound, and a modified product
and a multimer thereof (preferably an isocyanurate of the aliphatic polyisocyanate
compound) have a viscosity at 25C of, for example, 100 to 3000 mPas, preferably
500 to 2500 mPas, more preferably 1000 to 2000 mPas, and still more preferably
1200 to 1700 mPas.
[0028]
While the NCO content in the polyisocyanate compound (A) is not limited, it
is, for example, 15 to 45%, more preferably 20 to 40%, and still more preferably 20 to
35%.
[0029]
The polyisocyanate compound (A) is preferably (Aa-1) an isocyanurate of
polyisocyanate compound (more preferably (A1a-1) an isocyanurate of aliphatic
polyisocyanate compound);
the alicyclic polyisocyanate compound (A2) (more preferably hydrogenated
4,4'-diphenylmethane diisocyanate); or
the aromatic polyisocyanate compound (A3) (a polyisocyanate having a
carbodiimide group derived from 4,4'-diphenylmethane diisocyanate
(carbodiimide-modified MDI)),
because this can further improve the heat resistance and hydrolysis resistance.
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[0030]
In particular, examples of commercial products of the preferred
polyisocyanate compound (A) include DURANATE (registered trademark) TPA-100
(manufactured by Asahi Kasei Chemicals Corporation), Lupranate (registered
trademark) M5S (manufactured by BASF INOAC Polyurethanes Ltd.), WANNATE
(registered trademark) HMDI (hydrogenated MDI manufactured by Wanhua Chemical
(Japan) Co., Ltd.), and MILLIONATE (registered trademark) MTL manufactured by
Tosoh Corporation.
[0031]
A single polyisocyanate compound (A) may be used alone, or any two or more
polyisocyanate compounds (A) may be used in combination.
[0032]
In particular, it is preferred to use two polyisocyanate compounds (A), more
preferred to use a mixture of the isocyanurate of polyisocyanate compound (Aa-1) and
the alicyclic polyisocyanate compound (A2), and even more preferred to use a mixture
of the isocyanurate of aliphatic polyisocyanate compound (A1a-1) and hydrogenated
4,4'-diphenylmethane diisocyanate (A2).
[0033]
The amount of the polyisocyanate compound (A) is not limited as long as it is
an amount that can be employed in polyurethane resin compositions (particularly
polyurethane resin compositions for sealing electrical and electronic components).
For example, the amount of the polyisocyanate compound (A) is usually 0.01 to 25%
by mass, preferably 0.1 to 20% by mass, more preferably 1 to 10% by mass, and
particularly preferably 1.5 to 6% by mass, based on 100% by mass of the polyurethane
resin composition.
[0034]
Moreover, the amount of the polyisocyanate compound (A) is, for example, 5
to 75 parts by mass, preferably 8 to 65 parts by mass, and more preferably 10 to 60
parts by mass, based on 100 parts by mass of the polyol compound (B).
14
[0035]
When two or more polyisocyanate compounds (A) are blended in the
polyurethane resin composition of the present invention, the total amount of the
polyisocyanate compounds (A) can be adjusted based on the above-described amount
of the polyisocyanate compound (A). For example, when the isocyanurate of
polyisocyanate compound (Aa-1) and the alicyclic polyisocyanate compound (A2) are
blended as polyisocyanate compounds (A), the amount of the isocyanurate of
polyisocyanate compound (Aa-1) is usually 1 to 400 parts by mass, preferably 10 to
380 parts by mass, and more preferably 100 to 350 parts by mass, based on 100 parts
by mass of the alicyclic polyisocyanate compound (A2).
[0036]
When the aromatic polyisocyanate compound (A3) is contained in the
polyurethane resin composition of the present invention, the amount of the aromatic
polyisocyanate compound (A3) is usually 0.01 to 25% by mass, preferably 1 to 10%
by mass, and more preferably 2 to 4% by mass, based on 100% by mass of the
polyurethane resin composition.
[0037]
The amounts of the polyisocyanate compound (A) and the below-described
polyol compound (B) are such that the NCO/OH ratio (INDEX), which is the ratio of
the total number of moles of isocyanate groups in the polyisocyanate compound to the
total number of moles of hydroxyl groups in the polyol compound, is 0.5 to 1.5,
preferably 0.7 to 1.3, and more preferably 0.8 to 1.1.
[0038]
When the isocyanurate of polyisocyanate compound (Aa) (preferably the
isocyanurate of aliphatic polyisocyanate compound (A1a-1)) is contained as a
polyisocyanate compound (A), the amount of the isocyanurate of polyisocyanate
compound is usually 1 to 80 parts by mass, preferably 10 to 80 parts by mass, more
preferably 30 to 80 parts by mass, and still more preferably 50 to 80 parts by mass,
based on 100 parts by mass of the polyisocyanate compound (A), because this can
15
further improve the heat resistance and hydrolysis resistance.
[0039]
In addition to the isocyanurate of polyisocyanate compound (Aa-1)
(preferably the isocyanurate of aliphatic polyisocyanate compound (A1a-1)), when
(Ab) a multimer of polyisocyanate compound (preferably (A3b) a multimer of
aromatic polyisocyanate compound) is also contained as a polyisocyanate compound
(A), or when the multimer of polyisocyanate compound (Ab) (preferably the multimer
of aromatic polyisocyanate compound (A3b)) and (Aa-2) a carbodiimide of
polyisocyanate compound (preferably (A3a-2) a carbodiimide of aromatic
polyisocyanate compound) are also contained as polyisocyanate compounds (A), the
amount of the multimer (Ab) and/or the carbodiimide (Aa-2) is, for example, 1 to
1000 parts by mass, preferably 5 to 800 parts by mass, more preferably 8 to 700 parts
by mass, and still more preferably 65 to 500 parts by mass, based on 100 parts by
mass of the polyisocyanate compound (Aa-1), because this can further improve the
electrical characteristics.
[0040]
1-2. Polyol Compound (B)
The polyol compound (B) for use in the present invention includes (b1) a
polybutadiene polyol having a hydroxyl value of 60 mg KOH/g or less (hereinafter
also referred to as "polybutadiene polyol (b1)"). The polyol compound (B) is a
compound different from the below-described crosslinking agent or plasticizer.
Specifically, the polyol compound (B) does not include the alcohol compounds
included in the crosslinking agent or plasticizer. A polyol compound that does not
include castor oil or a castor oil-based polyol may be selected as the polyol compound
(B).
[0041]
Examples of commercial products of the polybutadiene polyol (b1) having a
hydroxyl value of 60 mg KOH/g or less include the polybutadiene polyols [the
"NISSO-PBG series" (G-1000, G-2000, G-3000, and the like) manufactured by
16
Nippon Soda Co., Ltd.; and the "Poly Bd (registered trademark) series" (R-45M,
R-45HT, CS-15, CN-15, and the like) manufactured by ARCO (US)].
[0042]
The hydroxyl value of the polybutadiene polyol (b1) is preferably 1 to 58 mg
KOH/g, more preferably 5 to 55 mg KOH/g, and particularly preferably 10 to 50 mg
KOH/g.
[0043]
While the hydroxyl group content in the polybutadiene polyol (b1) is not
limited, it is usually 0.001 to 3 mol/kg, preferably 0.01 to 2 mol/kg, and more
preferably 0.1 to 1.2 mol/kg.
[0044]
The number average molecular weight (Mn) of the polybutadiene polyol (b1)
is usually 100 to 5000, preferably 1000 to 4000, and more preferably 1500 to 3500.
[0045]
The viscosity (at 30C) of the polybutadiene polyol (b1) is usually 0.01 to 100
Pas, preferably 0.1 to 100 Pas, and more preferably 1 to 10 Pas.
[0046]
The iodine value of the polybutadiene polyol (b1) is usually 1 to 1000 g/100 g,
preferably 10 to 600 Pas, and more preferably 100 to 500 Pas.
[0047]
A single polybutadiene polyol (b1) having a hydroxyl value of 60 mg KOH/g
or less may be used alone, or two or more polybutadiene polyols (b1) may be used as a
mixture.
[0048]
The polyol compound (B) for use in the present invention may also include
(b2) a polyol compound containing one or more hydroxyl groups (hereinafter referred
to as "polyol (b2)") other than the polybutadiene polyol having a hydroxyl value of 60
mg KOH/g or less.
[0049]
17
Examples of the polyol (b2) include dimer acid polyols; castor oil-based
polyols; polydiene polyols (such as polyisoprene polyols); polyether polyols;
polyester polyols; polycarbonate polyols; polycaprolactone polyols; acrylic polyols;
and hydrogenated products thereof (for example, hydrogenated polydiene polyols).
[0050]
The dimer acid polyols are not limited, and may be known dimer acid polyols.
[0051]
The castor oil-based polyols are not limited; examples include castor oil and
castor oil derivatives.
[0052]
Examples of the castor oil derivatives include castor oil fatty acids;
hydrogenated castor oils obtained by hydrogenation of castor oil or castor oil fatty
acids; transesterification products of castor oil with other oils and fats; reaction
products of castor oil with polyhydric alcohols; esterification products of castor oil
fatty acids with polyhydric alcohols; and compounds obtained by addition
polymerization of alkylene oxides with these castor oil derivatives. Among these
castor oil-based polyols, castor oil is preferably used.
[0053]
Examples of the hydrogenated castor oils include the hydrogenated castor oil
disclosed in, for example, JP 2-298574 A. The hydrogenated castor oils are obtained
by hydrogenation of the castor oil-based polyols.
[0054]
The number average molecular weight (Mn) of the castor oil-based polyols is
usually 100 to 4000, and preferably 300 to 2500.
[0055]
The average hydroxyl value of the castor oil-based polyols is preferably 20 to
250 mg KOH/g, and more preferably 50 to 120 mg KOH/g, as determined according to
JIS K1557-1.
[0056]
18
As used herein, the number average molecular weight (Mn) may be measured
by gel permeation chromatography (GPC) (relative to polystyrene). Specifically, the
number average molecular weight based on GPC may be calculated by conducting
measurement at a column temperature of 40C, using the Shodex GPC System-21
manufactured by Showa Denko K.K. as the measurement apparatus, the Shodex
LF-804/KF-803/KF-804 manufactured by Showa Denko K.K. as the columns, and
NMP as the mobile phase, and then using a standard polystyrene calibration curve.
[0057]
Examples of the polydiene polyols include, but are not limited to,
polyisoprene polyols ["Poly ip" manufactured by Idemitsu Kosan Co., Ltd].
[0058]
Examples of the hydrogenated polydiene polyols include, but are not limited
to, hydrogenated polybutadiene polyols [the "NISSO-PBGI series" (GI-1000, GI-2000,
GI-3000, and the like) manufactured by Nippon Soda Co., Ltd.] and hydrogenated
polyisoprene polyols ["EPOL" manufactured by Idemitsu Kosan Co, Ltd.].
[0059]
Examples of the polyether polyols include, but are not limited to, polyether
polyols obtained by addition polymerization of alkylene oxides, such as ethylene
oxide, propylene oxide, and butylene oxide, with initiators, such as water, low
molecular weight polyols (such as propylene glycol, ethylene glycol, glycerin,
trimethylolpropane, and pentaerythritol), bisphenols (such as bisphenol A), and
dihydroxybenzenes (such as catechol, resorcinol, and hydroquinone). Specific
examples include polyethylene glycol, polypropylene glycol, and polytetramethylene
glycol.
[0060]
The polyester polyols are not limited, and can be obtained by, for example,
esterification of polyol components with acid components.
[0061]
Examples of the polyol components include, but are not limited to, ethylene
19
glycol, diethylene glycol, 1,3-butanediol, 1,4-butanediol, neopentylglycol,
3-methyl-1,5-pentanediol, 2-butyl-2-ethyl-1,3-propanediol,
2,4-diethyl-1,5-pentanediol, 1,2-hexanediol, 1,6-hexanediol, 1,8-octanediol,
1,9-nonanediol, 2-methyl-1,8-octanediol, 1,8-decanediol, octadecanediol, glycerin,
trimethylolpropane, pentaerythritol, hexanetriol, and polypropylene glycol.
[0062]
Examples of the acid components include, but are not limited to, succinic acid,
methylsuccinic acid, adipic acid, pimelic acid, azelaic acid, sebacic acid,
1,12-dodecanedioic acid, 1,14-tetradecanedioic acid, dimer acid,
2-methyl-1,4-cyclohexanedicarboxylic acid, 2-ethyl-1,4-cyclohexanedicarboxylic acid,
terephthalic acid, isophthalic acid, phthalic acid, isophthalic acid, terephthalic acid,
1,4-naphthalene dicarboxylic acid, 4,4'-biphenyl dicarboxylic acid, and acid
anhydrides thereof.
[0063]
Examples of the polycarbonate polyols include, but are not limited to,
polycarbonate polyols obtained by polycondensation of the polyol components with
phosgene; polycarbonate polyols obtained by transesterification and condensation of
the polyol components with carbonic acid diesters, such as dimethyl carbonate, diethyl
carbonate, dipropyl carbonate carbonate, diisopropyl carbonate, dibuty carbonate,
ethyl butyl carbonate, ethylene carbonate, propylene carbonate, diphenyl carbonate,
and dibenzyl carbonate; copolymerized polycarbonate polyols obtained by using two
or more of the polyol components in combination; polycarbonate polyols obtained by
esterification of the various polycarbonate polyols with carboxyl group-containing
compounds; polycarbonate polyols obtained by etherification of the various
polycarbonate polyols with hydroxyl group-containing compounds; polycarbonate
polyols obtained by transesterification of the various polycarbonate polyols with ester
compounds; polycarbonate polyols obtained by transesterification of the various
polycarbonate polyols with hydroxyl group-containing compounds; polyester-based
polycarbonate polyols obtained by polycondensation of the various polycarbonate
20
polyols with dicarboxylic acid compounds; and copolymerized polyether-based
polycarbonate polyols obtained by copolymerization of the various polycarbonate
polyols with alkylene oxides.
[0064]
Examples of the polycaprolactone polyols include, but are not limited to,
caprolactone-based polyester diols obtained by ring-opening polymerization of cyclic
ester monomers, such as -caprolactone and -valerolactone.
[0065]
Examples of the acrylic polyols include copolymers obtained by
copolymerization of hydroxyl group-containing acrylates with copolymerizable vinyl
monomers capable of copolymerization with the hydroxyl group-containing acrylates.
[0066]
Examples of the hydroxyl group-containing acrylates include 2-hydroxyethyl
(meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate,
2,2-dihydroxymethylbutyl (meth)acrylate, polyhydroxyalkylmaleates, and
polyhydroxyalkylfumarates. 2-Hydroxyethyl (meth)acrylate and the like are
preferred.
[0067]
Examples of the copolymerizable vinyl monomers include (C1-12) alkyl
(meth)acrylates, such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl
(meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, isobutyl
(meth)acrylate, s-butyl (meth)acrylate, t-butyl (meth)acrylate, pentyl (meth)acrylate,
isopentyl (meth)acrylate, hexyl (meth)acrylate, isononyl (meth)acrylate, 2-ethylhexyl
(meth)acrylate, and cyclohexyl acrylate;
aromatic vinyls, such as styrene, vinyltoluene, and -methylstyrene;
vinyl cyanides, such as (meth)acrylonitrile;
vinyl monomers containing a carboxyl group, such as (meth)acrylic acid,
fumaric acid, maleic acid, and itaconic acid, or alkyl esters thereof;
alkane polyol poly(meth)acrylates, such as ethylene glycol di(meth)acrylate,
21
butylene glycol di(meth)acrylate, hexanediol di(meth)acrylate, oligoethylene glycol
di(meth)acrylate, trimethylolpropane di(meth)acrylate, and trimethylolpropane
tri(meth)acrylate; and
vinyl monomers containing an isocyanate group, such as
3-(2-isocyanate-2-propyl)--methylstyrene.
[0068]
The acrylic polyols can be obtained by copolymerization of the hydroxyl
group-containing acrylates with the copolymerizable vinyl monomers, in the presence
of an appropriate solvent and an appropriate polymerization initiator.
[0069]
Examples of the acrylic polyols also include silicone polyols and fluorine
polyols.
[0070]
Examples of the silicone polyols include an acrylic polyol obtained by
blending a silicone compound containing a vinyl group, such as -methacryloxypropyl
trimethoxysilane, as a copolymerizable vinyl monomer, in the copolymerization of the
acrylic polyols described above.
[0071]
Examples of the fluorine polyols include an acrylic polyol obtained by
blending a fluorine compound containing a vinyl group, such as tetrafluoroethylene or
chlorotrifluoroethylene, as a copolymerizable vinyl monomer, in the copolymerization
of the acrylic polyols described above.
[0072]
Vinyl monomer-modified polyols can be obtained by reacting the high
molecular weight polyols and the vinyl monomers described above.
[0073]
As the polyol compound (B) for use in the present invention, the
polybutadiene polyol (b1) having a hydroxyl value of 60 mg KOH/g or less may be
used alone, or a mixture of the polybutadiene polyol (b1) having a hydroxyl value of
22
60 mg KOH/g or less and the hydroxyl group-containing compound (b2) other than
the polybutadiene polyol having a hydroxyl value of 60 mg KOH/g or less may be
used. Two or more polybutadiene polyols having different molecular weights may be
used as the polybutadiene polyol (b1). A mixture of two or more hydroxyl
group-containing compounds (b2) other than the polybutadiene polyol may be used as
the hydroxyl group-containing compound (b2).
[0074]
By the inclusion of the polybutadiene polyol (b1) as a hydroxyl
group-containing compound in the polyurethane resin composition of the present
invention, the moisture resistance and the heating cycle characteristic of the
polyurethane resin composition can be improved.
[0075]
While the amount of the polybutadiene polyol (b1) for use in the present
invention is not limited, it is usually 0.01 to 25% by mass, preferably 1 to 20% by
mass, and more preferably 5 to 15% by mass, based on 100% by mass of the
polyurethane resin composition.
[0076]
1-3. Inorganic Filler(C)
The polyurethane resin composition of the present invention comprises (C) an
inorganic filler.
[0077]
Examples of the inorganic filler (C) for use in the present invention include,
but are not limited to, metal hydroxides, metal oxides, metal nitrides, and zeolite.
[0078]
Examples of the metal hydroxides include aluminum hydroxide and
magnesium hydroxide.
[0079]
Examples of the metal oxides include aluminum oxide (alumina), magnesium
oxide, silicon oxides (such as silica), and titanium oxide.
23
[0080]
Examples of the metal nitrides include boron nitride, aluminum nitride, and
silicon nitride.
[0081]
The zeolite is not limited, and may be any zeolite used in known polyurethane
resin compositions.
[0082]
In particular, the zeolite is preferably a crystalline hydrated aluminosilicate of
an alkali metal or an alkaline earth metal.
[0083]
Examples of crystalline forms of the zeolite include, but are not limited to,
forms A, X, and LSX. In particular, crystalline form A is preferred.
[0084]
Examples of the alkali metal or alkaline earth metal in the zeolite include, but
are not limited to, potassium, sodium, calcium, and lithium. In particular, potassium
is preferred.
[0085]
The inorganic filler is preferably a metal hydroxide or a metal oxide, more
preferably aluminum hydroxide or alumina, and particularly preferably aluminum
hydroxide.
[0086]
A single inorganic filler (C) may be used alone, or a mixture of two or more
inorganic fillers (C) may be used.
[0087]
The amount of the inorganic filler (C) is usually 50 to 85% by mass,
preferably 52 to 75% by mass, more preferably 54 to 70% by mass, and particularly
preferably 55 to 69% by mass, based on 100% by mass of the polyurethane resin
composition.
[0088]
24
The shape of the inorganic filler (C) may be either spherical or indefinite.
[0089]
1-4. Plasticizer (D)
The polyurethane resin composition of the present invention comprises (D) a
plasticizer.
[0090]
Examples of the plasticizer (D) for use in the present invention include, but
are not limited to, phthalic acid ester-based plasticizers, such as dioctyl phthalate,
diisononyl phthalate, and diundecyl phthalate; adipic acid ester-based plasticizers,
such as dioctyl adipate, diisononyl adipate, and diisodecyl adipate; castor oil
ester-based plasticizers, such as methyl acetyl ricinoleate, butyl acetyl ricinoleate,
acetylricinoleic triglyceride, and acetylpolyricinoleic triglyceride; trimellitic acid
ester-based plasticizers, such as trioctyl trimellitate and triisononyl trimellitate; and
pyromellitic acid ester-based plasticizers, such as tetraoctyl pyromellitate and
tetraisononyl pyromellitate.
[0091]
A plasticizer that does not include an ester compound represented by general
formula (1):
wherein R1 and R2 each independently represent a C6-12 alkyl group; X
represents a C3-8 alkylene group; and a and b each independently represent an integer
from 2 to 10, with the proviso that a sum of a and b is 4 to 20, can be selected as the
plasticizer (D).
[0092]
In particular, the plasticizer (D) is preferably a phthalic acid ester-based
plasticizer or an adipic acid ester-based plasticizer, and more preferably an
25
adipate-based plasticizer.
[0093]
The amount of the plasticizer (D) is usually 1 to 30% by mass, preferably 10
to 29% by mass, more preferably 12 to 28% by mass, and particularly preferably 15 to
26% by mass, based on 100% by mass of the polyurethane resin composition.
[0094]
A single plasticizer (D) may be used alone, or a mixture of two or more
plasticizers (D) may be used.
[0095]
1-5. Crosslinking Agent (Chain Extender) (E)
The polyurethane resin composition of the present invention may further
comprise (E) a crosslinking agent (synonym: chain extender).
[0096]
The crosslinking agent (E) is not limited, and examples include (E1) an
alcohol-based crosslinking agent and (E2) an amine-based crosslinking agent.
[0097]
Examples of the alcohol-based crosslinking agent (E1) include (E1-1) an
aromatic alcohol-based crosslinking agent, such as N,N-bis(2-hydroxypropyl)aniline,
hydroquinone-bis(-hydroxyethyl) ether, or resorcinol-bis(-hydroxyethyl) ether; and
(E1-2) an aliphatic alcohol-based crosslinking agent, such as ethylene glycol,
1,4-butanediol, octanediol, trimethylolpropane, or triisopropanolamine.
[0098]
Examples of the amine-based crosslinking agent (E2) include (E2-1) an
aromatic amine-based crosslinking agent, such as phenylenediamine, tolylenediamine,
diphenyldiamine, 4,4'-diaminodiphenylmethane,
3,3'-dichloro-4,4'-diaminodiphenylmethane, 1,2-bis(2-aminophenylthio)ethane, or
trimethylene glycol-p-aminobenzoate; and
(E2-2) an aliphatic amine-based crosslinking agent, such as ethylenediamine,
propylenediamine, hexamethylenediamine, or diethylenetriamine.
26
[0099]
In particular, the aromatic alcohol-based crosslinking agent (E1-1) and the
aliphatic alcohol-based crosslinking agent (E1-2) are preferred, and the aromatic
alcohol-based crosslinking agent (E1-1) is more preferred.
[0100]
The number average molecular weight of the crosslinking agent (E) is usually
1000 or less, preferably 500 or less, and more preferably 400 or less.
[0101]
When the polyurethane resin composition of the present invention comprises
the crosslinking agent (E), the amount of the crosslinking agent (E) is, for example,
usually 0.01 to 30% by mass, preferably 0.1 to 20% by mass, more preferably 0.3 to
10% by mass, and particularly preferably 0.5 to 5% by mass, based on 100% by mass
of the polyurethane resin composition, although not limited thereto.
[0102]
A single crosslinking agent (E) may be used alone, or a mixture of two or
more crosslinking agents (E) may be used.
[0103]
1-6. Defoaming Agent (F)
The polyurethane resin composition of the present invention may further
optionally contain (F) a defoaming agent.
[0104]
Examples of the defoaming agent for use in the present invention include, but
are not limited to, silicones (oil-type, compound-type, self-emulsifying-type,
emulsion-type, and the like) and alcohols.
[0105]
A preferred silicone-based defoaming agent is a modified silicone-based
defoaming agent (particularly a defoaming agent containing a polysiloxane as a
lipophilic group, and modified with a hydrophilic group).
[0106]
27
A single defoaming agent (F) may be used alone, or a mixture of two or more
defoaming agents (F) may be used.
[0107]
When the defoaming agent (F) is contained, the amount of the defoaming
agent (F) is preferably 0.001 to 10% by mass, and more preferably 0.005 to 5% by
mass, based on 100% by mass of the polyurethane resin composition, although not
limited thereto.
[0108]
1-7. Polymerization Catalyst (G)
The polyurethane resin composition of the present invention may further
optionally contain (G) a polymerization catalyst.
[0109]
The polymerization catalyst (G) may be a known polymerization catalyst, and
examples include metal catalysts, such as organotin catalysts, organolead catalysts,
and organobismuth catalysts; and amine catalysts.
[0110]
Examples of the organotin catalysts include dioctyltin dilaurate, dibutyltin
diacetate, dibutyltin dilaurate, and dioctyltin diacetate.
[0111]
Examples of the organolead catalysts include lead octylate, lead octenoate,
and lead naphthenate.
[0112]
Examples of the organobismuth catalysts include bismuth octylate and
bismuth neodecanoate.
[0113]
Examples of the amine catalysts include diethylenetriamine, triethylamine,
N,N-dimethylcyclohexylamine, N,N,N',N'-tetramethylethylenediamine,
N,N,N',N"N"-pentamethyldiethylenetriamine, trimethylenediamine,
dimethylaminoethanol, and bis(2-dimethylaminoethyl) ether. The catalyst may also
28
be an organometallic compound, a metal complex compound, or the like.
[0114]
When the polymerization catalyst (G) is contained, the amount of the
polymerization catalyst (G) is, for example, usually 0.00001 to 10% by mass,
preferably 0.0001 to 5% by mass, and more preferably 0.001 to 1 part by mass, based
on 100% by mass of the polyurethane resin composition, although not limited thereto.
[0115]
A single polymerization catalyst (G) may be used alone, or a mixture of two
or more polymerization catalysts (G) may be used.
[0116]
1-8. Other Components
The polyurethane resin composition of the present invention may further
optionally contain various additives, such as an antioxidant, a tackifier, a curing
accelerator, a colorant, a chain extender, a crosslinking agent, a filler, a pigment, a
bulking agent, a flame retardant, a urethanization catalyst, an ultraviolet absorber, a
dessicant, an antifungal agent, and a silane coupling agent.
[0117]
The amounts of these components may be appropriately selected according to
their purpose of use, from the range of amounts to be added similar to the range
usually employed, so as not to impair the desired characteristics of the polyurethane
resin composition.
[0118]
The polyurethane resin composition of the present invention need not contain
a blowing agent. Specifically, the polyurethane resin composition of the present
invention is intended for heat dissipation and the like by means of the inorganic filler,
whereas a urethane foam containing a blowing agent is intended for heat insulation
and the like; thus, they differ in their purpose.
[0119]
2. Method for Producing the Polyurethane Resin Composition
29
The method for producing the polyurethane resin composition of the present
invention is not limited; the polyurethane resin composition of the present invention
may be produced according to a known method used to produce a polyurethane resin
composition.
[0120]
Examples of such methods include a method including the steps of preparing a
composition (first component) containing the polyisocyanate compound (A) (step 1);
preparing a composition (second component) containing the polyol compound (B)
(step 2); and mixing the second component and the first component to give a
polyurethane resin composition (step 3).
[0121]
Other components may be contained in either the second component or the
first component, as long as the first component (formulation I) contains the
polyisocyanate compound (A), and the second component (formulation II) contains
the polyol compound (B).
[0122]
The first component (formulation I) may contain other components besides
the polyisocyanate compound (A).
[0123]
Likewise, the second component (formulation II) may contain other
components besides the polyol compound (B).
[0124]
For example, when the first component (formulation I) contains the polyol
compound besides the polyisocyanate compound (A), the first component
(formulation I) may be a urethane prepolymer having a terminal isocyanate (NCO)
group.
[0125]
Likewise, when the second component (formulation II) contains the
polyisocyanate compound (A) besides the polyol compound (B), the second
30
component (formulation II) may be a urethane prepolymer having a terminal hydroxyl
(OH) group.
[0126]
Specifically, the urethane prepolymer (X) is obtained by reacting components
including the polyisocyanate compound (A) and the polyol compound (B). The
urethane prepolymer (X) includes not only the urethane prepolymer obtained by
reacting components including the polyisocyanate compound (A) and the polyol
compound (B), but also a urethane prepolymer obtained by reacting the components
(A) and (B), the crosslinking agent (E), optional components, and the like, as well as a
urethane prepolymer further containing the other components described above.
[0127]
More specifically, the polyurethane resin composition of the present invention
may have, for example, a structure in which the first component contains the
polyisocyanate compound (A) and the plasticizer (D), and the second component
contains the polyol compound (B) and the inorganic filler (C);
a structure in which the first component contains the polyisocyanate
compound (A), and the second component contains the polyol compound (B), the
inorganic filler (C), and the plasticizer (D); or
a structure in which the first component contains the polyisocyanate
compound (A) and the plasticizer (D), and the second component contains the polyol
compound (B), the inorganic filler (C), and the plasticizer (D).
[0128]
Alternatively, the polyurethane resin composition of the present invention
may have, for example, a structure in which the first component contains the
polyisocyanate compound (A) and the inorganic filler (C), and the second component
contains the polyol compound (B);
a structure in which the first component contains the polyisocyanate
compound (A) and the plasticizer (D), and the second component contains the polyol
compound (B), the inorganic filler (C), the plasticizer (D), and the crosslinking agent
31
(E);
a structure in which the first component contains the polyisocyanate
compound (A) and the plasticizer (D), and the second component contains the polyol
compound (B), the inorganic filler (C), the plasticizer (D), the crosslinking agent (E),
and the defoaming agent (F); or
a structure in which the first component contains the polyisocyanate
compound (A) and the plasticizer (D), and the second component contains the polyol
compound (B), the inorganic filler (C), the plasticizer (D), the crosslinking agent (E),
the defoaming agent (F), and the polymerization catalyst (G).
[0129]
In the production of the polyurethane resin composition, the first component
(formulation I) is usually used in an amount of 1 to 1000 parts by mass, preferably 3
to 100 parts by mass, and more preferably 5 to 25 parts by mass, based on 100 parts by
mass of the second component (formulation II).
The first component is blended with other components, in order to reduce the
viscosity of the polyisocyanate compound, and adjust the ratio of the first component
to the second component (blend ratio). Thus, the first component may be used
without blending other components.
[0130]
In the polyurethane resin composition, a polyurethane resin may be formed by
partially or completely reacting the polyisocyanate compound (A) and the polyol
compound (B). That is, the polyurethane resin composition may be liquid before
being cured, or may be in a cured state. The polyurethane resin composition may be
cured, for example, in the following manner: The first component and the second
component are mixed to cause the polyisocyanate compound (A) and the polyol
compound (B) to react to form a polyurethane resin, and thus, the polyurethane resin
composition is cured with time. Alternatively, the polyurethane resin composition
may be cured by heating. In this case, the heating temperature is preferably about 40
to 120C, and the heating time is preferably about 0.5 to 24 hours.
32
[0131]
3. Uses
The present invention also provides a sealing material comprising the
polyurethane resin composition. The sealing material comprising the polyurethane
resin composition is excellent in heat dissipation properties, hydrolysis resistance, and
flame retardancy, and has a less decrease in flame retardancy even when used in a
high-temperature environment, and therefore, can be suitably used for, for example,
semiconductors and electrical and electronic components that generate heat.
[0132]
Examples of such electrical and electronic components include device control
boards, various sensors, and transformers, such as a transformer coil, a choke coil, and
a reactor coil. Such electrical and electronic components are also included as one
aspect of the present invention. The electrical and electronic components of the
present invention can be used for, for example, electric washing machines, toilet seats,
kettles, water purifiers, bathrooms, dish washers, power tools, automobiles, and
motorcycles.
Examples
[0133]
The polyurethane resin composition of the present invention will be
specifically described hereinafter, with reference to examples and comparative
examples; however, the examples are merely illustrative, and do not limit the present
invention.
[0134]
The raw materials used in the examples and comparative examples are given
below:
[0135]

a1: TPA-100
33
Trade name: DURANATE (registered trademark) TPA-100
(isocyanurate-modified HDI) manufactured by Asahi Kasei Chemicals Corporation
a2: HMDI
Trade name: WANNATE (registered trademark) HMDI (hydrogenated MDI)
manufactured by Wanhua Chemical (Japan) Co., Ltd.
a3: MTL
Trade name: MILLIONATE (registered trademark) MTL
(carbodiimide-modified MDI) manufactured by Tosoh Corporation
[0136]

b1: R-45HT
Trade name: Poly bd (registered trademark) R-45 HT manufactured by
Idemitsu Petrochemical Co., Ltd.; number average molecular weight: 2800, hydroxyl
value: 46.6 mg KOH/g (JIS K 1557), hydroxyl group content: 0.83 mol/kg (JIS K
1557), iodine value: 398 g/100 g (JIS K 0070), viscosity: 5 PaS/30C (JIS K 2283)
b2: (comparative polyol compound): R-15HT
Trade name: Poly bd (registered trademark) R-15 HT manufactured by
Idemitsu Petrochemical Co., Ltd.; number average molecular weight: 1200, hydroxyl
value: 102.7 mg KOH/g (JIS K 1557), hydroxyl group content: 1.83 mol/kg (JIS K
1557), iodine value: 420 g/100 g (JIS K 0070), viscosity: 1.5 PaS/30C (JIS K 2283)
[0137]

c1: H-32
Trade name: HIGILITE (registered trademark) H-32 (aluminum hydroxide)
manufactured by Showa Denko K.K.
[0138]

d1: diisodecyl adipate (DIDA)
Trade name: DIDANB manufactured by Taoka Chemical Co., Ltd.
34
d2: diundecyl phthalate (DUP)
Trade name: DUP manufactured by J-PLUS Co., Ltd.
[0139]

e1: trade name: OK Ohru 100 manufactured by Okahata Sangyo Co., Ltd.;
molecular weight: 212
e1: trade name: OCTANEDIOL manufactured by KH Neochem Co., Ltd.;
molecular weight: 145
[0140]

f1: SC-5570
Trade name: SC-5570 (silicone defoaming agent) manufactured by Dow
Corning Toray Co., Ltd.
[0141]

g1: U-810
Trade name: NEOSTANN U-810 (dioctyltin dilaurate) manufactured by Nitto
Kasei Co., Ltd.
[0142]
[Preparation of Polyurethane Resin Compositions]
(Examples 1 to 11 and Comparative Examples 1 to 6)
Various polyurethane resin compositions were each prepared by blending the
components to give each composition shown in Table 1, along with 0.01% by weight
of SC-5570 (silicone defoaming agent) as a defoaming agent, according to the
following procedure.
[0143]
The polyol compound (B), the inorganic filler (C), the plasticizer (D), the
crosslinking agent (E), the defoaming agent (F), and the polymerization catalyst (G)
shown in Table 1 were mixed using a planetary centrifugal mixer (THINKY MIXER
35
manufactured by THINKY CORPORATION) at 2000 rpm for 1 minute.
The polyisocyanate compound (A) shown in Table 1 was added to the mixed
components, and the mixture was mixed using a planetary centrifugal mixer (THINKY
MIXER manufactured by THINKY CORPORATION) at 2000 rpm for 1 minute. The
resulting mixture was defoamed to give each of the polyurethane resin compositions
of Examples 1 to 11 and Comparative Examples 1 to 6.
[0144]

Each of the polyurethane resin compositions was poured into a 130  130  3
mm mold, a mold with an inner diameter of 30 mm and a height of 10 mm, or a 10 
80  3 mm mold. The polyurethane resin composition was subsequently heated at
60C for 16 hours and then allowed to cure at room temperature for 1 day to give a
test piece A (130  130  3 mm), a test piece B (with a diameter of 30 mm and a
height of 10 mm), and a test piece C (10  80  3 mm).
[0145]
The test piece A was prepared into a test piece D of the dumbbell shape No. 3
shown in JIS K6251, and a tensile test was conducted on this test piece at a
measurement temperature of 25C and a tensile speed of 500 mm/min, according to
the method specified in section 3 of JIS K6251, to measure the elongation (flexibility).
The results are shown in Table 1.
[0146]
Additionally, the test piece A (130  130  3 mm), the test piece B (with a
diameter of 30 mm and a height of 10 mm), and/or the test piece C (10  80  3 mm)
were tested for hardness, compatibility, workability, heat resistance, elastic modulus
(DMA method: 10 Hz), and volume resistivity according to the test methods given
below. The results are shown in Table 1.
[0147]

The hardness (type A) of the test piece B (the cured product B; inner
36
diameter: 30 mm, height: 10 mm) at a temperature of 23C was measured with a
durometer (ASKER Type A Durometer for rubber manufactured by Kobunshi Keiki
Co., Ltd.), according to JIS K 6253.
[0148]

The liquid mixture of "the polyol compound, the crosslinking agent, the
plasticizer, the defoaming agent, the inorganic filler, and the polymerization catalyst"
was heated in a dryer at 60C for 1 week and then cooled to room temperature (23C).
The external appearance of the resulting mixture was examined. Compatibility
(external appearance) was evaluated according to the following evaluation criteria:
[0149]
A: There was no transparent layer (phase separation) on the top layer
(supernatant) of the liquid mixture.
C: There was a transparent layer (phase separation) on the top layer
(supernatant) of the liquid mixture.
[0150]

Flowability was examined by tilting a container containing the liquid mixture
of "the polyisocyanate, the polyol compound, the crosslinking agent, the plasticizer,
the defoaming agent, the inorganic filler, and the polymerization catalyst" to pour the
mixture into the 130  130  3 mm mold, the mold with an inner diameter of 30 mm
and a height of 10 mm, or the 10  80  3 mm mold, by allowing the mixture to fall
naturally. Workability (flowability) was evaluated according to the following
evaluation criteria:
[0151]
A: The liquid mixture flowed and spread completely to conform to the shape
of the mold.
C: The liquid mixture did not flow and spread to conform to the shape of the
mold.
37
[0152]

After the measurement of the initial hardness, the test piece B was heated in a
dryer at 100C for 500 hours and then cooled to room temperature (23C). The
hardness (final hardness) of the test piece was measured in the same manner as that
for the initial hardness. Using the initial hardness and the final hardness, a hardness
change rate was calculated based on the following equation:
[0153]
Equation: hardness change rate (%) = [(final hardness  initial hardness) /
initial hardness]  100
Based on the hardness change rate thus calculated, heat resistance was
evaluated according to the following evaluation criteria:
[0154]
A: A hardness change rate of less than 30%
B: A hardness change rate of 30% or more and less than 40%
C: A hardness change rate of 40% or more
[0155]

The elongation (flexibility) of the test piece D was evaluated according to JIS
K 6251, based on the following equation:
[0156]
Equation: elongation = {[(test length of the dumbbell at break)  (test length
of the dumbbell)] ÷ (test length of the dumbbell)}  100
A: An elongation of 100% or more
B: An elongation of 80% or more and less than 100
C: An elongation of less than 80%
[0157]

The elastic modulus (10 Hz) of the test piece C was measured using a
38
dynamic viscoelasticity measurement apparatus DMA (DMS 6100 manufactured by
SII Nano Technology Inc.). The elastic modulus was evaluated according to the
evaluation criteria given below.
An elastic modulus at 40C (10 Hz) of 40 MPa or less was evaluated as
acceptable.
[0158]
A change in the elastic modulus (MPa) of the test piece C was evaluated based
on the following equation:
Equation: change in elastic modulus (MPa) = ([elastic modulus (MPa) at
40C]  [elastic modulus (MPa) at 120C])
A change in elastic modulus from 40 to 120C of 40 MPa or less was
evaluated as acceptable.
A change in elastic modulus from 40 to 120C of 30 MPa or less was
evaluated as excellent.
[0159]

The volume resistivity of the test piece A was measured using a resistance
measurement apparatus (DSM-8104 manufactured by HIOKI E.E. CORPORATION).
Based on the measurement result, the electrical insulating properties were evaluated
according to the evaluation criteria given below. Table 1 shows the measurement
values of volume resistivity (cm) and the evaluation results. A volume resistivity
of 1  1012 cm or more was evaluated as acceptable.
[0160]
In the table, "-" means that there is no data because the polyurethane resin was
unable to be molded.
[0161]
39
[Table 1]
1 2 3 4 5 6 7 8 9 10 11 1 2 3 4 5 6
TPA-100 2.1 2.3 2.5 2.1 2.1 0.8 1.5 1.7 1.7 3.1 3.4
HMDI 0.8 0.8 2.5 0.6 0.6 0.8 1.5 0.5 0.5 0.9 1.0
MTL 2.4 2.4 2.6 2.5 3.6 3.9
R-15 HT (Comparative) 9.6 9.0 9.0 11.9 18.0
R-45 HT 9.1 9.7 8.8 9.6 9.6 13.2 13.2 13.4 13.2 13.3 12.0 18.5
H-32 64.7 64.0 65.7 63.3 63.4 64.9 64.3 64.3 63.4 64.3 58.0 63.7 66.2 66.2 60.2 77.0 77.0
DIDA (d1) 4.3 9.6 13.3 15.9 16.0 3.7 4.2 19.3 25.0 5.7
DUP (d2) 17.5 12.2 4.4 7.4 7.4 20.2 19.4 15.6 15.9 23.2 22.5 16.8 23.4
OK Ohru (E1) 1.4 1.3 2.7 0.5 0.6 0.6 0.6 0.7 0.4 0.6 0.5
OCTANEDIOL (E2) 0.4 0.7 0.6 0.6 0.4
U-830 0.1 0.1 0.1 0.1 0.1 0.1 0.01 0.02 0.02 0.02 0.1 0.1
100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100
0.84 0.93 0.99 0.88 0.91 0.96 0.99 0.99 0.93 1.02 1.00 0.89 0.77 0.77 0.95 0.95 0.75
A A A A A A A A A A A A A A A － －
A A A A A A A A A A A A A A A C C
48 48 50 50 45 24 32 32 32 32 35 46 48 44 42 － －
Volume Resistivity Ωcm 5E+12 6E+12 4E+12 4E+12 4E+13 1E+13 1E+14 1E+14 2E+14 1E+14 2E+13 4E+12 4E+12 5E+12 2E+12 － －
A A A A A B A A A A A C C C B － －
-40°C 21 17 19 18 14 38 38 32 27 19 8 81 57 33 46 － －
120°C 2 3 1 4 2 4 1 4 2 1 2 2 2 3 2 － －
Temperature Dependence A A A A A B B B B Ａ A C C B C － －
Hardness Change Rate A A A A A A B B B B B A A A B － －
Weight Change Rate 0.3% 0.8% 1.1% 1.1% 1.2% 0.1% or less 0.3% 0.6% 0.6% 1.0% 1.0% 0.1% or less 0.1% or less 0.5% 0.3% － －
Comparative Examples
Polyisocyanate Compound (A)
Total Amount of Polyurethane Resin Composition
Polyol Compound (B)
Inorganic Filler (C)
Plasticizer (D)
Crosslinking Agent (E)
Polymerization Catalyst (G)
NCO/OH Equivalents (index)
Hardness A
Elongation
Table 1 Examples
Heat Cycle
Characteristic
Elastic Modulus
(10 Hz)
Heat Resistance
Liquid Characteristics Compatibility
Workability
Physical Properties
of Cured Product
40
[0162]

The results of Examples 1 to 11 demonstrate that the polyurethane resin
compositions of the present invention have reduced temperature dependence of elastic
modulus (120 to 40C), exhibit excellent elongation (flexibility), 5 and have a less
change in hardness due to thermal degradation.
[0163]
Furthermore, the polyurethane resin compositions of the present invention
were found to be satisfactory in terms of all of excellent compatibility, workability,
10 hardness, and volume resistivity.
[0164]
In contrast, the compositions of Comparative Examples 1 to 6 were not found
to be satisfactory in terms of all of temperature dependence of elastic modulus,
elongation (flexibility), change in hardness due to thermal degradation, compatibility,
15 workability, hardness, and volume resistivity.
[0165]
The elongations and elastic moduli measured for the compositions of
Examples 1, 4, and 11 of Examples 1 to 11, after allowing them to stand at 100C for
700 hours, were compared with the data measured for the composition of Comparative
20 Example 4. The results are shown in Table 2.
[0166]
41
[Table 2]
Table 2 Examples Comparative
Example
1 4 11 4
Polyisocyanate Compound
(A)
TPA-100 2.1 2.1
HMDI 0.8 0.6
MTL 3.6 3.9
Polyol Compound (B)
R-15 HT
(Comparative) 11.9
R-45 HT 9.1 9.6 12.0
Inorganic Filler (C) H-32 64.7 63.3 58.0 60.2
Plasticizer (D) DIDA (d1) 4.3 15.9 25.0
DUP (d2) 17.5 7.4 23.4
Crosslinking Agent (E) OK Ohru (E1) 1.4 0.5 0.7 0.6
OCTANEDIOL (E2) 0.4 0.6
Polymerization Catalyst U-830 0.1 0.1 0.01
Total Amount of Polyurethane Resin Composition 100 100 100 100
Physical
Properties of
Cured Product
Hardness Change Rate A A B B
Elongation A A A C
Heat Cycle
Characteristic
Elastic
Modulus
(10 Hz)
40°C 29 24 15 170
120C 2 9 2 4
Temperature
Dependence A A A C
[0167]

The results of Examples 1, 4, and 11 demonstrate that the 5 polyurethane resin
compositions of the present invention, even after being allowed to stand at 100C for
700 hours, are superior to the composition of Comparative Example 4 in terms of
elastic modulus and elongation (flexibility), and have a less change in hardness due to
thermal degradation.
10
Industrial Applicability
42
[0168]
A polyurethane resin cured product obtained using the polyurethane resin
composition of the present invention is satisfactory in terms of all of heat resistance,
moisture resistance, and heat cycle characteristic, and thus, can be used in the fields of
electrical appliances, electronic components, 5 and the like.
43
We Claim:
[Claim 1]
A polyurethane resin composition comprising (A) a polyisocyanate compound,
(B) a polyol compound, (C) an inorganic filler, and (D) a plasticizer, 5 wherein
the polyol compound (B) includes (b1) a polybutadiene polyol having a
hydroxyl value of 60 mg KOH/g or less, and
the inorganic filler (C) is contained in an amount of 50 to 85% by mass, and
the plasticizer (D) is contained in an amount of 1 to 30% by mass, based on 100% by
10 mass of the polyurethane resin composition.
[Claim 2]
The polyurethane resin composition according to claim 1, wherein a change in
elastic modulus ([elastic modulus at 40C]  [elastic modulus at 120C]) is 40 MPa
15 or less.
[Claim 3]
The polyurethane resin composition according to claim 1 or 2, wherein the
change in elastic modulus ([elastic modulus at 40C]  [elastic modulus at 120C]) is
20 30 MPa or less.
[Claim 4]
The polyurethane resin composition according to any one of claims 1 to 3,
wherein the polyisocyanate compound (A) is an isocyanurate of an aliphatic
25 polyisocyanate compound, a cycloaliphatic polyisocyanate, and/or an aromatic
polyisocyanate.
[Claim 5]
The polyurethane resin composition according to any one of claims 1 to 4,
44
wherein the polybutadiene polyol (b1) having a hydroxyl value of 60 mg KOH/g or
less is contained in an amount of 5 to 15% by mass, based on 100% by mass of the
polyurethane resin composition.
5 [Claim 6]
The polyurethane resin composition according to any one of claims 1 to 5,
wherein the polyol compound (B) does not include castor oil or a castor oil-based
polyol.
10 [Claim 7]
The polyurethane resin composition according to any one of claims 1 to 6,
wherein the plasticizer (D) does not include an ester compound represented by general
formula (1):
15
wherein R1 and R2 each independently represent a C6-12 alkyl group; X
represents a C3-8 alkylene group; and a and b each independently represent an integer
from 2 to 10, with the proviso that a sum of a and b is 4 to 20.
20 [Claim 8]
The polyurethane resin composition according to any one of claims 1 to 7,
wherein the polybutadiene polyol (b1) has a number average molecular weight (Mn)
of 100 to 5000.
25 [Claim 9]
The polyurethane resin composition according to any one of claims 1 to 8,
wherein the polybutadiene polyol (b1) has a viscosity (30C) of 0.01 to 100 Pas.
45
[Claim 10]
The polyurethane resin composition according to any one of claims 1 to 9,
wherein the plasticizer (D) includes (d1) an adipic acid-based plasticizer and/or (d2) a
phthalic acid-5 based plasticizer.
[Claim 11]
The polyurethane resin composition according to any one of claims 1 to 10,
wherein the plasticizer (D) is contained in an amount of 10 to 29% by mass, based on
10 100% by mass of the polyurethane resin composition.
[Claim 12]
A polyurethane resin composition comprising (A) a polyisocyanate compound,
(B) a polyol compound, (C) an inorganic filler, and (D) a plasticizer, wherein
15 the polyisocyanate compound (A) is an isocyanurate of an aliphatic
polyisocyanate compound, a cycloaliphatic polyisocyanate, and/or an aromatic
polyisocyanate,
the polyol compound (B) includes (b1) a polybutadiene polyol having a
hydroxyl value of 60 mg KOH/g or less, and
20 the polyol compound (B) does not include castor oil or a castor oil-based
polyol,
the plasticizer (D) does not include an ester compound represented by general
formula (1):
25
wherein R1 and R2 each independently represent a C6-12 alkyl group; X
represents a C3-8 alkylene group; and a and b each independently represent an integer
46
from 2 to 10, with the proviso that a sum of a and b is 4 to 20,
the polybutadiene polyol (b1) having a hydroxyl value of 60 mg KOH/g or
less is contained in an amount of 5 to 15% by mass, the inorganic filler (C) is
contained in an amount of 50 to 85% by mass, and the plasticizer (D) is contained in
an amount of 1 to 30% by mass, based on 100% by mass of the 5 polyurethane resin
composition, and
a change in elastic modulus ([elastic modulus at 40C]  [elastic modulus at
120C]) is 30 MPa or less.
10 [Claim 13]
The polyurethane resin composition according to any one of claims 1 to 12,
which is used for sealing an electrical or electronic component.
[Claim 14]
15 A sealing material comprising the polyurethane resin composition according
to any one of claims 1 to 13.
[Claim 15]
An electrical or electronic component resin-sealed with the sealing material
20 according to claim 14.