【Technical Field】
[1] [Cross-Reference to Related Application]
[2] This application claims priority to Korean Patent
Application No. 10-2021-0009294, filed on January 22, 2021
10 in the Korean Intellectual Property Office, the disclosure
of which is incorporated herein by reference.
[3]
[4] The present invention relates to a thermoplastic
resin composition, a method of preparing the same, and a
15 molded article including the same. More particularly, the
present invention relates to a thermoplastic resin
composition that has mechanical properties, such as impact
strength, tensile strength, and flexural strength, and
surface hardness equal or superior to those of a
20 conventional ASA-based resin composition, has excellent
2
transparency and colorability, is capable of preventing
occurrence of whitening during bending due to excellent nonwhitening
properties, and thus, has excellent surface
appearance; a method of preparing the thermoplastic resin
composition, and 5 a molded article including the
thermoplastic resin composition.
【Background Art】
[5] Acrylate-styrene-acrylonitrile copolymers
10 (hereinafter referred to as "ASA resins") have weather
resistance, aging resistance, chemical resistance, rigidity,
impact resistance, and processability, and have been used in
various fields such as automobiles, miscellaneous goods, and
construction materials.
15 [6] In addition, as the importance of aesthetics
increases in the market, research is being conducted to
realize a luxurious appearance and excellent colorability
and weather resistance by finishing the surface of a
substrate, such as an acrylonitrile-butadiene-styrene resin,
20 a polyvinyl chloride resin, a polyehyleneterephthalate resin,
3
or an iron plate, with an ASA resin.
[7] However, due to the characteristics of ASA resins,
when finishing treatment is performed at room temperature,
whitening may occur on the surface of a product depending on
the shape of the product 5 in a processing process such as
cutting, bending, and molding. Due to whitening, the
original color of the product disappears, and aesthetics is
impaired. This phenomenon is caused by voids due to cracks
generated inside an ASA resin. To solve this problem, a
10 method of softening a resin by increasing a rubber content
has been tried. Since the mechanical properties of a
softened ASA resin are different from those of a
conventional ASA resin, the use of the softened ASA resin is
limited.
15 [8] Therefore, there is a need to develop a
thermoplastic resin composition having excellent
transparency, colorability, and non-whitening properties
while having mechanical properties and surface hardness
similar to those of conventional ASA-based resin
20 compositions.
4
[9]
[10] [Related Art Documents]
[11] [Patent Documents]
[12] Japanese Patent No. 1995-033470
5
【Disclosure】
【Technical Problem】
[13] Therefore, the present invention has been made in
view of the above problems, and it is one object of the
10 present invention to provide a thermoplastic resin
composition that has mechanical properties, such as impact
strength, tensile strength, and flexural strength, and
surface hardness equal or superior to those of a
conventional ASA-based resin composition, has excellent
15 transparency and colorability, is capable of preventing
occurrence of whitening during bending due to excellent nonwhitening
properties, and thus, has excellent surface
appearance.
[14] It is another object of the present invention to
20 provide a method of preparing the thermoplastic resin
5
composition.
[15] It is yet another object of the present invention to
provide a molded article manufactured using the
thermoplastic resin composition.
5 [16]
[17] The above and other objects can be accomplished by
the present invention described below.
【Technical Solution】
10 [18] In accordance with one aspect of the present
invention, provided is a thermoplastic resin composition
including 25 to 75 % by weight of an alkyl acrylate-aromatic
vinyl compound-vinyl cyanide compound graft copolymer (A)
containing alkyl acrylate rubber having an average particle
15 diameter of 50 to 120 nm; and 25 to 75 % by weight of a
(meth)acrylic acid alkyl ester compound-aromatic vinyl
compound-vinyl cyanide compound non-graft copolymer (B),
wherein the thermoplastic resin composition has an alkyl
acrylate coverage value (X) of 67 % or more as calculated by
20 Equation 1 below:
6
[19] [Equation 1]
[20] X = {(G-Y)/Y} × 100,
[21] wherein G represents a gel content (wt%) based on a
total weight of the thermoplastic resin composition, and Y
represents a content (5 wt%) of an alkyl acrylate in the gel
based on a total weight of the thermoplastic resin
composition.
[22]
[23] In addition, the present invention may provide a
10 thermoplastic resin composition including 25 to 75 % by
weight of an alkyl acrylate-aromatic vinyl compound-vinyl
cyanide compound graft copolymer (A) containing alkyl
acrylate rubber having an average particle diameter of 50 to
120 nm; and 25 to 75 % by weight of a (meth)acrylic acid
15 alkyl ester compound-aromatic vinyl compound-vinyl cyanide
compound non-graft copolymer (B), wherein the non-graft
copolymer (B) includes 60 to 85 % by weight of a
(meth)acrylic acid alkyl ester compound, 5 to 30 % by weight
of an aromatic vinyl compound, and 1 to 25 % by weight of a
20 vinyl cyanide compound.
7
[24]
[25] In addition, the present invention may provide a
thermoplastic resin composition including 25 to 75 % by
weight of an alkyl acrylate-aromatic vinyl compound-vinyl
cyanide compound graft 5 copolymer (A) containing alkyl
acrylate rubber having an average particle diameter of 50 to
120 nm; and 25 to 75 % by weight of a (meth)acrylic acid
alkyl ester compound-aromatic vinyl compound-vinyl cyanide
compound non-graft copolymer (B), wherein the thermoplastic
10 resin composition has a total light transmittance (Tt) of
74 % or more as measured using an injection specimen having
a thickness of 3T according to ASTM D-1003.
[26]
[27] In accordance with another aspect of the present
15 invention, provided is a method of preparing a thermoplastic
resin composition, the method including kneading and
extruding, at 200 to 300 °C and 100 to 500 rpm, 25 to 75 %
by weight of an alkyl acrylate-aromatic vinyl compound-vinyl
cyanide compound graft copolymer (A) containing alkyl
20 acrylate rubber having an average particle diameter of 50 to
8
120 nm and 25 to 75 % by weight of a (meth)acrylic acid
alkyl ester compound-aromatic vinyl compound-vinyl cyanide
compound non-graft copolymer (B), wherein the thermoplastic
resin composition has an alkyl acrylate coverage value (X)
of 67 % or more as 5 calculated by Equation 1 below:
[28] [Equation 1]
[29] X = {(G-Y)/Y} × 100,
[30] wherein G represents a gel content (wt%) based on a
total weight of the thermoplastic resin composition, and Y
10 represents a content (wt%) of an alkyl acrylate in the gel
based on a total weight of the thermoplastic resin
composition.
[31]
[32] In addition, the present invention may provide a
15 method of preparing a thermoplastic resin composition, the
method including kneading and extruding, at 200 to 300 °C
and 100 to 500 rpm, 25 to 75 % by weight of an alkyl
acrylate-aromatic vinyl compound-vinyl cyanide compound
graft copolymer (A) containing alkyl acrylate rubber having
20 an average particle diameter of 50 to 120 nm and 25 to 75 %
9
by weight of a (meth)acrylic acid alkyl ester compoundaromatic
vinyl compound-vinyl cyanide compound non-graft
copolymer (B), wherein the non-graft copolymer (B) includes
60 to 85 % by weight of a (meth)acrylic acid alkyl ester
compound, 5 to 30 % by weight 5 of an aromatic vinyl compound,
and 1 to 25 % by weight of a vinyl cyanide compound.
[33]
[34] In addition, the present invention may provide a
method of preparing a thermoplastic resin composition, the
10 method including kneading and extruding, at 200 to 300 °C
and 100 to 500 rpm, 25 to 75 % by weight of an alkyl
acrylate-aromatic vinyl compound-vinyl cyanide compound
graft copolymer (A) containing alkyl acrylate rubber having
an average particle diameter of 50 to 120 nm and 25 to 75 %
15 by weight of a (meth)acrylic acid alkyl ester compoundaromatic
vinyl compound-vinyl cyanide compound non-graft
copolymer (B), wherein the thermoplastic resin composition
has a total light transmittance (Tt) of 74 % or more as
measured using an injection specimen having a thickness of
20 3T according to ASTM D-1003.
10
[35]
[36] In accordance with yet another aspect of the present
invention, provided is a molded article including the
thermoplastic resin composition.
5
【Advantageous effects】
[37] According to the present invention, the present
invention has an effect of providing a thermoplastic resin
composition that has mechanical properties, such as impact
10 strength, tensile strength, and flexural strength, and
surface hardness equal or superior to those of a
conventional ASA-based resin composition, has excellent
transparency and colorability, is capable of preventing
occurrence of whitening during bending due to excellent non15
whitening properties, and thus, has excellent surface
appearance; a method of preparing the thermoplastic resin
composition; and a molded article including the
thermoplastic resin composition. In particular, the
thermoplastic resin composition of the present invention can
20 be used in the manufacture of finishing materials,
11
decorative sheets, and the like requiring a luxurious
appearance.
【Description of Drawings】
[38] FIG. 1 includes images 5 taken after ball droppinginduced
impact is applied to T-die extrusion films
manufactured in Example 3 and Comparative Examples 1 and 6.
【Best mode】
10 [39] Hereinafter, a thermoplastic resin composition, a
method of preparing the same, and a molded article including
the same according to the present invention will be
described in detail.
[40] The present inventors confirmed that, when an alkyl
15 acrylate-aromatic vinyl compound-vinyl cyanide compound
graft copolymer containing rubber having a predetermined
average particle diameter and a (meth)acrylic acid alkyl
ester compound-aromatic vinyl compound-vinyl cyanide
compound non-graft copolymer were mixed in a predetermined
20 composition ratio, and an alkyl acrylate coverage value was
12
adjusted within a predetermined range, compared to a
conventional ASA-based resin composition, mechanical
properties, surface hardness, transparency, and colorability
were improved, and occurrence of whitening during bending
was prevented due to excellent 5 non-whitening properties.
Based on these results, the present inventors conducted
further studies to complete the present invention.
[41]
[42] The thermoplastic resin composition of the present
10 invention includes 25 to 75 % by weight of an alkyl
acrylate-aromatic vinyl compound-vinyl cyanide compound
graft copolymer (A) containing alkyl acrylate rubber having
an average particle diameter of 50 to 120 nm; and 25 to 75 %
by weight of a (meth)acrylic acid alkyl ester compound15
aromatic vinyl compound-vinyl cyanide compound non-graft
copolymer (B), wherein the thermoplastic resin composition
has an alkyl acrylate coverage value (X) of 67 % or more as
calculated by Equation 1 below:
[43] [Equation 1]
20 [44] X = {(G-Y)/Y} × 100
13
[45] In Equation 1, G represents a gel content (wt%)
based on a total weight of the thermoplastic resin
composition, and Y represents the content (wt%) of an alkyl
acrylate in the gel based on a total weight of the
5 thermoplastic resin composition.
[46] In this case, the thermoplastic resin composition
may have mechanical properties, such as impact strength,
tensile strength, and flexural strength, and surface
hardness equal or superior to those of a conventional ASA10
based resin, may have excellent transparency and
colorability, may prevent occurrence of whitening during
bending due to excellent non-whitening properties, and thus,
may have excellent surface appearance.
[47]
15 [48] Hereinafter, each component constituting the
thermoplastic resin composition of the present invention
will be described in detail.
[49]
[50] (A) Alkyl acrylate-aromatic vinyl compound-vinyl
20 cyanide compound graft copolymer
14
[51] For example, the graft copolymer (A) may contain
alkyl acrylate rubber having an average particle diameter of
50 to 120 nm, preferably 60 to 120 nm, still more preferably
80 to 110 nm. Within this range, a finally prepared
thermoplastic resin composition 5 may have excellent impact
strength, light resistance, and gloss.
[52] In this description, the average particle diameter
may be measured by dynamic light scattering, and
specifically, may be measured as an intensity value using a
10 particle size analyzer (product name: Nicomp 380,
manufacturer: PSS) in a Gaussian mode. As a specific
measurement example, a sample may be prepared by diluting
0.1 g of latex (total solids content: 35 to 50 wt%) 1,000 to
5,000-fold with distilled water, and average particle
15 diameter may be measured using flow cells in an autodilution
manner and in a mode of dynamic light
scattering/intensity 300 kHz/intensity-weight Gaussian
analysis. At this time, temperature may be set to 23 °C,
measurement wavelength may be set to 632.8 nm, and channel
20 width may be set to 10 μsec.
15
[53]
[54] For example, based on a total weight of the
components (A) and (B), the graft copolymer (A) may be
included in an amount of 25 to 75 % by weight, preferably 30
to 70 % by weight, more 5 preferably 30 to 60 % by weight,
still more preferably 30 to 55 % by weight. Within this
range, mechanical properties, such as impact strength,
tensile strength, and flexural strength, gloss, surface
hardness, and processability may be excellent.
10 [55] For example, the graft copolymer (A) may include 20
to 60 % by weight of alkyl acrylate rubber (a-1) and 40 to
80 % by weight of an aromatic vinyl compound-vinyl cyanide
compound copolymer (a-2), preferably 30 to 50 % by weight of
alkyl acrylate rubber (a-1) and 50 to 70 % by weight of an
15 aromatic vinyl compound-vinyl cyanide compound copolymer (a-
2), more preferably 40 to 50 % by weight of alkyl acrylate
rubber (a-1) and 50 to 60 % by weight of an aromatic vinyl
compound-vinyl cyanide compound copolymer (a-2). Within
this range, mechanical properties, gloss, and surface
20 hardness may be excellent.
16
[56] In this description, a polymer including a certain
compound means a polymer prepared by polymerizing the
compound, and a unit in the polymer is derived from the
compound.
5 [57]
[58] For example, the alkyl acrylate rubber (a-1) may
further include an aromatic vinyl compound. In this case,
chemical resistance and impact resistance may be excellent.
For example, based on 100 % by weight in total of the
10 acrylate rubber, the alkyl acrylate rubber (a-1) may include
the aromatic vinyl compound in an amount of 0.1 to 25 % by
weight, preferably 2 to 23 % by weight, more preferably 5 to
20 % by weight, still more preferably 5 to 16 % by weight,
still more preferably 10 to 16 % by weight. Within this
15 range, mechanical properties, gloss, and surface hardness
may be excellent without deterioration of physical
properties.
[59] For example, the copolymer (a-2) may further include
an alkyl acrylate. In this case, physical property balance
20 between impact resistance, weather resistance,
17
processability, and non-whitening properties may be
excellent.
[60] For example, based on 100 % by weight in total of
the copolymer (a-2), the copolymer (a-2) may include 55 to
85 % by weight of an aromatic 5 vinyl compound, 10 to 30 % by
weight of a vinyl cyanide compound, and 0.1 to 20 % by
weight of an alkyl acrylate, preferably 60 to 80 % by weight
of an aromatic vinyl compound, 13 to 26 % by weight of a
vinyl cyanide compound, and 3 to 20 % by weight of an alkyl
10 acrylate, more preferably 65 to 78 % by weight of an
aromatic vinyl compound, 15 to 22 % by weight of a vinyl
cyanide compound, and 5 to 20 % by weight of an alkyl
acrylate. Within this range, impact resistance and weather
resistance may be excellent.
15 [61]
[62] For example, the graft copolymer (A) may be prepared
by emulsion polymerization. In this case, gloss and surface
hardness may be excellent.
[63] For example, the alkyl acrylate may be an alkyl
20 acrylate containing an alkyl group having 1 to 15 carbon
18
atoms, preferably includes one or more selected from the
group consisting of methyl acrylate, ethyl acrylate, propyl
acrylate, butyl acrylate, 2-ethylbutyl acrylate, octyl
acrylate, 2-ethylhexyl acrylate, hexyl acrylate, heptyl
acrylate, n-pentyl acrylate, 5 and lauryl acrylate. More
preferably, the alkyl acrylate is an alkyl acrylate having 2
to 8 carbon atoms, still more preferably butyl acrylate,
ethylhexyl acrylate, or a mixture thereof, still more
preferably butyl acrylate.
10 [64] For example, the aromatic vinyl compound may include
one or more selected from the group consisting of styrene,
α-methyl styrene, ο-methyl styrene, p-methyl styrene, mmethyl
styrene, ethyl styrene, isobutyl styrene, t-butyl
styrene, o-bromostyrene, p-bromostyrene, m-bromostyrene, ο-
15 chlorostyrene, p-chlorostyrene, m-chlorostyrene,
vinyltoluene, vinylxylene, fluorostyrene, and
vinylnaphthalene, preferably one or more selected from the
group consisting of styrene and α-methyl styrene, more
preferably styrene. In this case, processability may be
20 excellent due to proper fluidity, and mechanical properties
19
such as impact resistance may be excellent.
[65] For example, the vinyl cyanide compound may include
one or more selected from the group consisting of
acrylonitrile, methacrylonitrile, ethylacrylonitrile, and
isopropylacrylonitrile, 5 preferably acrylonitrile.
[66] Emulsion polymerization commonly practiced in the
art to which the present invention pertains may be used in
the present invention without particular limitation.
[67]
10 [68] For example, the graft copolymer (A) may have a
grafting degree of 55 to 150 %, preferably 60 to 130 %, more
preferably 65 to 100 %, still more preferably 65 to 80 % as
calculated by Equation 3 below. Within this range, gloss,
colorability, and transparency may be excellent, and due to
15 excellent non-whitening properties, occurrence of whitening
during bending may be prevented.
[69] [Equation 3]
[70] Grafting degree (%) = [Weight (g) of grafted
monomers/Rubber weight (g)] × 100.

【Claim 1】
A thermoplastic resin composition, comprising:
25 to 75 % by weight 5 of an alkyl acrylate-aromatic
vinyl compound-vinyl cyanide compound graft copolymer (A)
containing alkyl acrylate rubber having an average particle
diameter of 50 to 120 nm; and
25 to 75 % by weight of a (meth)acrylic acid alkyl
10 ester compound-aromatic vinyl compound-vinyl cyanide
compound non-graft copolymer (B),
wherein the thermoplastic resin composition has an
alkyl acrylate coverage value (X) of 67 % or more as
calculated by Equation 1 below:
15 [Equation 1]
X = {(G-Y)/Y} × 100,
wherein G represents a gel content (wt%) based on a
total weight of the thermoplastic resin composition, and Y
represents a content (wt%) of an alkyl acrylate in the gel
69
based on a total weight of the thermoplastic resin
composition.
【Claim 2】
The thermoplastic resin composition 5 according to claim
1, wherein the non-graft copolymer (B) comprises 60 to 85 %
by weight of a (meth)acrylic acid alkyl ester compound, 5 to
30 % by weight of an aromatic vinyl compound, and 1 to 25 %
by weight of a vinyl cyanide compound.
10
【Claim 3】
The thermoplastic resin composition according to claim
1, wherein the non-graft copolymer (B) has a weight average
molecular weight of 30,000 to 150,000 g/mol.
15
【Claim 4】
The thermoplastic resin composition according to claim
1, wherein the graft copolymer (A) comprises 20 to 60 % by
weight of alkyl acrylate rubber (a-1) and 40 to 80 % by
70
weight of an aromatic vinyl compound-vinyl cyanide compound
copolymer (a-2).
【Claim 5】
The thermoplastic resin composition 5 according to claim
1, wherein the graft copolymer (A) has a grafting degree of
55 % or more as calculated by Equation 3 below:
[Equation 3]
Grafting degree (%) = [Weight (g) of grafted
10 monomers/Rubber weight (g)] × 100,
wherein the weight (g) of grafted monomers is obtained
by subtracting the rubber weight (g) from a weight of
insoluble matter (gel) obtained by dissolving a graft
copolymer in acetone and performing centrifugation, and the
15 rubber weight (g) is a weight (g) of rubber components
theoretically added to graft copolymer powder.
【Claim 6】
The thermoplastic resin composition according to claim
20 1, wherein the thermoplastic resin composition has a total
71
light transmittance (Tt) of 74 % or more as measured using
an injection specimen having a thickness of 3T according to
ASTM D-1003.
5 【Claim 7】
The thermoplastic resin composition according to claim
1, wherein the thermoplastic resin composition has a haze of
10 % or less as measured using an injection specimen having
a thickness of 3T according to ASTM D-1003.
10
【Claim 8】
The thermoplastic resin composition according to claim
1, wherein, when a 1 kg weight is vertically dropped onto an
extruded film having dimensions of 0.15 mm × 10 cm × 10 cm
15 in thickness, width, and length from a height of 25 cm using
a Gardner impact tester, haze values before and after impact
are measured for a portion of the film hit by the weight
according to ASTM D1003, and a difference in the haze values
is calculated, the thermoplastic resin composition has a
20 haze difference (△Haze) of 6.7 or less.
72
【Claim 9】
The thermoplastic resin composition according to claim
1, wherein, when a sheet having a thickness of 0.15 mm is
manufactured using a T-5 die extruder, the sheet is cut to a
length of 100 cm, thickness is measured at 10 or more
locations in an area except for an area within 2 to 3 cm
from both ends of the sheet, and thickness deviation is
calculated based on a difference between maximum and minimum
10 thicknesses, the thermoplastic resin composition has a
thickness deviation of 0.07 mm or less.
【Claim 10】
The thermoplastic resin composition according to claim
15 1, wherein the thermoplastic resin composition comprises one
or more selected from the group consisting of a heat
stabilizer, a light stabilizer, a dye, a pigment, a
colorant, a lubricant, a release agent, an antistatic agent,
an antibacterial agent, a processing aid, a metal
20 deactivator, a flame retardant, a smoke suppressant, an
73
anti-drip agent, an anti-friction agent, and an anti-wear
agent.
【Claim 11】
A method of 5 preparing a thermoplastic resin
composition, comprising kneading and extruding, at 200 to
300 °C and 100 to 500 rpm, 25 to 75 % by weight of an alkyl
acrylate-aromatic vinyl compound-vinyl cyanide compound
graft copolymer (A) containing alkyl acrylate rubber having
10 an average particle diameter of 50 to 120 nm and 25 to 75 %
by weight of a (meth)acrylic acid alkyl ester compoundaromatic
vinyl compound-vinyl cyanide compound non-graft
copolymer (B),
wherein the thermoplastic resin composition has an
15 alkyl acrylate coverage value (X) of 67 % or more as
calculated by Equation 1 below:
[Equation 1]
X = {(G-Y)/Y} × 100,
wherein G represents a gel content (wt%) based on a
20 total weight of the thermoplastic resin composition, and Y
74
represents a content (wt%) of an alkyl acrylate in the gel
based on a total weight of the thermoplastic resin
composition.
5 【Claim 12】
A molded article, comprising the thermoplastic resin
composition according to any one of claims 1 to 10.
【Claim 13】
10 The molded article according to claim 12, wherein the
molded article is an injection-molded article, a
calendering-molded article, or an extrusion-molded article.