【Technical Field】
[1] [Cross-Reference to Related Application]
[2] This application claims priority to Korean Patent
Application No. 10-2020-0128801, filed on October 06, 2020 in
10 the Korean Intellectual Property Office, the disclosure of
which is incorporated herein by reference.
[3] The present invention relates to a thermoplastic
resin composition, a method of preparing the same, and a
molded article including the same. More particularly, the
15 present invention relates to a thermoplastic resin
composition prepared by adding, in a predetermined
composition ratio, a polycarbonate resin and a polyester
resin to a base resin including a vinyl cyanide compoundconjugated
diene rubber-aromatic vinyl compound graft
20 copolymer, an α-methyl styrene-vinyl cyanide compound2
aromatic vinyl compound copolymer, and an aromatic vinyl
compound-vinyl cyanide compound copolymer. Due to these
compositional features, the mechanical properties,
moldability, heat resistance, and chemical resistance of the
thermoplastic resin composition 5 may be significantly improved.
【Background Art】
[4] Acrylonitrile-butadiene-styrene resins (hereinafter
referred to as "ABS resins") based on conjugated diene rubber
10 have excellent processability, mechanical properties, and
appearance, and thus have been used in various fields, such
as parts of electrical and electronic products, automobiles,
small toys, furniture, and building materials. However, since
ABS resins lack heat resistance compared to engineering
15 plastics, use of the ABS resins in parts of
electric/electronic products or automotive interior materials
requiring heat resistance, high strength, and chemical
resistance is limited.
[5] Polycarbonate (hereinafter referred to as "PC resin")
20 and ABS resin alloy materials are widely used in various
3
applications such as automobiles and electrical/electronic
products due to excellent mechanical properties and low price
thereof. For automobile application, the alloy materials are
mainly used for automobile interior materials, such as center
fascia and door trim. However, 5 in the case of PC/ABS, since
PC/ABS has weak chemical resistance due to the amorphous
nature thereof, use thereof is limited. Environmental stress
cracking (ESC) caused by chemical products in automobile
interior materials is a chronic and serious quality problem.
10 In particular, cracks are often generated by chemicals that
are frequently used inside automobiles, and demand for
chemical-resistant materials that can prevent such problems
in advance is increasing.
[6] Therefore, there is a demand for the development of a
15 material that can be applied to automobile interior materials
by satisfying high heat resistance, chemical resistance,
rigidity and having proper moldability.
[7] [Related Art Documents]
[8] [Patent Documents]
20 [9] KR 10-0488857 B1
4
【Disclosure】
【Technical Problem】
[10] Therefore, the present invention has been made in
view of the above problems, and 5 it is one object of the
present invention to provide a thermoplastic resin
composition having excellent mechanical properties,
moldability, heat resistance, and chemical resistance.
[11] It is another object of the present invention to
10 provide a method of preparing the thermoplastic resin
composition and a molded article manufactured using the
thermoplastic resin composition.
[12] The above and other objects can be accomplished by
the present invention described below.
15
【Technical Solution】
[13] In accordance with one aspect of the present
invention, provided is a thermoplastic resin composition
including 20 to 40 % by weight of a vinyl cyanide compound20
conjugated diene rubber-aromatic vinyl compound graft
5
copolymer (A), 10 to 35 % by weight of an α-methyl styrenevinyl
cyanide compound-aromatic vinyl compound copolymer (B),
5 to 30 % by weight of an aromatic vinyl compound-vinyl
cyanide compound copolymer (C), 23 to 47 % by weight of a
polycarbonate resin (D), and 3 5 to 17 % by weight of a
polyester resin (E), wherein a weight of the copolymer (B) is
greater than or equal to a weight of the copolymer (C), and a
weight ratio of the polycarbonate resin (D) to the polyester
resin (E) is 2:1 to 6:1.
10 [14]
[15] In accordance with another aspect of the present
invention, provided is a method of preparing a thermoplastic
resin composition, the method including kneading and
extruding 20 to 40 % by weight of a vinyl cyanide compound15
conjugated diene rubber-aromatic vinyl compound graft
copolymer (A), 10 to 35 % by weight of an α-methyl styrenevinyl
cyanide compound-aromatic vinyl compound copolymer (B),
5 to 30 % by weight of an aromatic vinyl compound-vinyl
cyanide compound copolymer (C), 23 to 47 % by weight of a
20 polycarbonate resin (D), and 3 to 17 % by weight of a
6
polyester resin (E) at 200 to 280 °C, wherein a weight of the
copolymer (B) is greater than or equal to a weight of the
copolymer (C), and a weight ratio of the polycarbonate resin
(D) to the polyester resin (E) is 2:1 to 6:1.
5 [16]
[17] In accordance with yet another aspect of the present
invention, provided is a molded article including the
thermoplastic resin composition.
10 【Advantageous effects】
[18] According to the present invention, by adding, in a
specific ratio, a polycarbonate resin and a polyester resin
to a base resin including a vinyl cyanide compound-conjugated
diene rubber-aromatic vinyl compound graft copolymer
15 (hereinafter referred to as "ABS-based resin"), an α-methyl
styrene-vinyl cyanide compound copolymer (hereinafter
referred to as "heat-resistant SAN-based resin"), and a vinyl
cyanide compound-aromatic vinyl compound copolymer
(hereinafter referred to as "SAN-based resin") in a
20 predetermined weight ratio, the present invention
7
advantageously provides a thermoplastic resin composition
having excellent mechanical properties, moldability, heat
resistance, and chemical resistance; a method of preparing
the same; and a molded article manufactured using the same.
5
【Description of Drawings】
[19] FIG. 1 shows the chemical resistance test results of
Examples according to the present invention and Comparative
Examples.
10
【Best mode】
[20] 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
15 in detail.
[21] The present inventors confirmed that, when an ABSbased
resin was compounded with a heat-resistant SAN-based
resin and a general SAN-based resin to improve heat
resistance and moldability, and a polycarbonate resin and a
20 polyester resin were added thereto in a predetermined weight
8
ratio, in addition to mechanical properties and heat
resistance, chemical resistance was greatly improved. Based
on these results, the present inventors conducted further
studies to complete the present invention.
5 [22]
[23] The thermoplastic resin composition of the present
invention includes 20 to 40 % by weight of a vinyl cyanide
compound-conjugated diene rubber-aromatic vinyl compound
graft copolymer (A), 10 to 35 % by weight of an α-methyl
10 styrene-vinyl cyanide compound-aromatic vinyl compound
copolymer (B), 5 to 30 % by weight of an aromatic vinyl
compound-vinyl cyanide compound copolymer (C), 23 to 47 % by
weight of a polycarbonate resin (D), and 3 to 17 % by weight
of a polyester resin (E), wherein the weight of the copolymer
15 (B) is greater than or equal to the weight of the copolymer
(C), and the weight ratio of the polycarbonate resin (D) to
the polyester resin (E) is 2:1 to 6:1. In this case,
mechanical properties, moldability, heat resistance, and
chemical resistance may be excellent.
20 [24]
9
[25] In this description, the composition ratio of a
(co)polymer may mean the content of units constituting the
(co)polymer, or may mean the content of units input during
polymerization of the (co)polymer.
5 [26]
[27] Hereinafter, each component constituting the
thermoplastic resin composition of the present invention will
be described in detail.
[28]
10 [29] (A) Vinyl cyanide compound-conjugated diene rubberaromatic
vinyl compound graft copolymer
[30] Based on a total weight of the thermoplastic resin
composition, the vinyl cyanide compound-conjugated diene
rubber-aromatic vinyl compound graft copolymer (A)
15 (hereinafter referred to as “graft copolymer (A)”) is
included in an amount of 20 to 40 % by weight. In this case,
mechanical properties, moldability, and appearance may be
excellent. As a preferred example, based on 100 % by weight
in total of the thermoplastic resin composition, the graft
20 copolymer (A) may be included in an amount of 20 to 35 % by
10
weight, more preferably 20 to 30 % by weight. Within this
range, mechanical properties, moldability, appearance, and
physical property balance may be excellent.
[31]
[32] For example, the graft 5 copolymer (A) may include 50
to 80 % by weight of conjugated diene rubber comprising a
conjugated diene compound, 5 to 20 % by weight of a vinyl
cyanide compound, and 10 to 40 % by weight of an aromatic
vinyl compound. In this case, mechanical properties,
10 moldability, appearance, and physical property balance may be
excellent. As a preferred example, the graft copolymer (A)
includes 50 to 70 % by weight of conjugated diene rubber, 5
to 15 % by weight of a vinyl cyanide compound, and 20 to 40 %
by weight of an aromatic vinyl compound, more preferably 55
15 to 65 % by weight of conjugated diene rubber, 10 to 15 % by
weight of a vinyl cyanide compound, and 20 to 30 % by weight
of an aromatic vinyl compound. Within this range, impact
resistance and physical property balance may be excellent.
[33] For example, an average particle diameter of the
20 conjugated diene rubber included in the graft copolymer (A)
11
may be 2,000 to 5,000 Å, preferably 2,000 to 4,000 Å, more
preferably 2,500 to 3,500 Å. Within this range, impact
strength may be excellent without deterioration in other
physical properties.
[34] In this description, average 5 particle diameter of the
conjugated diene rubber may be measured by dynamic light
scattering, and specifically, may be measured as an intensity
value using a Nicomp 380 particle size analyzer (manufacturer:
PSS) in a Gaussian mode.
10 [35]
[36] For example, the graft copolymer (A) may have a
grafting degree of 20 to 70 %, preferably 20 to 55 %, more
preferably 20 to 45 %. Within this range, appropriate
compatibility and moldability may be secured, and balance
15 between compatibility, moldability, and other mechanical
properties may be excellent.
[37] In this description, to measure grafting degree,
graft (co)polymer latex is coagulated, washed, and dried to
obtain powder, and then 1 g of the obtained powder is added
20 to 30 ml of acetone, followed by stirring for 24 hours. Then,
12
the stirred solution is centrifuged at 14,000 rpm for 4 hours
using an ultracentrifuge to obtain insoluble matter, and the
insoluble matter is dried at 85 °C for 4 hours. Then, the
weight of the dried insoluble matter is measured, and
grafting degree is calculated 5 by substituting the measured
value into Equation 1 below.
[38] [Equation 1]
[39] Grafting degree (%) = [{Weight (g) of dried insoluble
matter - weight (g) of rubber added during graft
10 polymerization} / weight (g) of rubber added during graft
polymerization] × 100
[40] The drying may proceed until there is no further
change in weight.
[41]
15 [42] For example, the graft copolymer (A) may have a
weight average molecular weight of 500,000 to 1,000,000 g/mol,
preferably 650,000 to 900,000 g/mol. Within this range, due
to proper fluidity, excellent processability and impact
resistance may be secured.
20 [43] In this description, weight average molecular weight
13
may be measured at 40 °C using tetrahydrofuran (THF) as a
solvent using a gel permeation chromatograph (GPC) filled
with porous silica as a column packing material. In this case,
weight average molecular weight is obtained as a relative
value to a polystyrene 5 (PS) standard sample.
[44]
[45] For example, the graft copolymer (A) may be prepared
by a known polymerization method including emulsion
polymerization, suspension polymerization, bulk
10 polymerization, and the like, preferably emulsion
polymerization.
[46] For example, based on 100 parts by weight in total of
the conjugated diene rubber, the aromatic vinyl compound, and
the vinyl cyanide compound included in the graft copolymer,
15 the graft copolymer (A) may be prepared by adding,
continuously or batchwise, a monomer mixture including 5 to
20 parts by weight of the vinyl cyanide compound and 10 to 40
parts by weight of the aromatic vinyl compound to a mixed
solution containing 50 to 80 parts by weight (based on solids)
20 of conjugated diene rubber, 0.1 to 5 parts by weight of an
14
emulsifier, 0.1 to 3 parts by weight of a molecular weight
modifier, and 0.05 to 1 part by weight of an initiator and
then performing polymerization.
[47] As another example, based on 100 parts by weight in
total of the conjugated 5 diene rubber, the aromatic vinyl
compound, and the vinyl cyanide compound, the graft copolymer
(A) may be prepared by adding, at 65 to 75 °C for 2 to 4
hours, a mixed solution including 5 to 20 parts by weight of
the vinyl cyanide compound, 10 to 40 parts by weight of the
10 aromatic vinyl compound, 10 to 50 parts by weight of
deionized water, 0.09 to 1.5 parts by weight of an initiator,
0.1 to 2 parts by weight of an emulsifier, and 0.05 to 1.5
parts by weight of a molecular weight modifier, which has
been mixed in a separate mixing device, to 50 to 80 parts by
15 weight (based on solids) of conjugated diene rubber latex and
60 to 150 parts by weight of deionized water; adding 0.01 to
0.5 parts by weight of an initiator thereto; raising
temperature to 75 to 80 °C for 30 to 90 minutes; and
terminating graft polymerization at a polymerization
20 conversion rate of 93 to 99 % by weight. In this case, impact
15
resistance, mechanical strength, and moldability may be
excellent.
[48] In this description, based on 100 % of the total
weight of monomers input until polymerization is completed,
polymerization conversion rate 5 may be defined as % by weight
of the monomers converted into a polymer until measurement
time. A method of measuring polymerization conversion rate is
not particularly limited as long as the method follows this
definition. As a specific example, after drying 1.5 g of
10 prepared (co)polymer latex in a hot air dryer at 150 °C for
15 minutes, the weight of the dried latex is measured, and
total solids content (TSC) is calculated by Equation 2 below.
Then, polymerization conversion rate is calculated by
substituting the total solids content value into Equation 3
15 below. In Equation 3, the total weight of added monomers is
given as 100 parts by weight.
[49] [Equation 2]
[50] Total solids content (TSC; %) = (Weight after drying
/ Weight before drying) × 100
20 [51] [Equation 3]
16
[52] Polymerization conversion rate (%) = [Total solids
content (TSC) × (Total weight of added monomers, deionized
water, and subsidiary raw materials) / 100] - (Weight of
added subsidiary raw materials other than monomers and
5 deionized water)
[53] In Equation 3, subsidiary raw materials include an
initiator, an emulsifier, and a molecular weight modifier,
and include an electrolyte when the electrolyte is used.
[54]
10 [55] For example, the conjugated diene compound may
include one or more selected from the group consisting of
1,3-butadiene, 2,3-dimethyl-1,3-butadiene, 2-ethyl-1,3-
butadiene, 1,3-pentadiene, isoprene, chloroprene, and
pyrerylene.
15 [56] For example, the vinyl cyanide compound may include
one or more selected from the group consisting of
acrylonitrile, methacrylonitrile, ethylacrylonitrile, and
isopropylacrylonitrile, preferably acrylonitrile.
[57] For example, the aromatic vinyl compound may include
20 one or more selected from the group consisting of styrene, α-
17
methyl styrene, ο-methyl styrene, p-methyl styrene, m-methyl
styrene, ethyl styrene, isobutyl styrene, t-butyl styrene, ο-
bromostyrene, p-bromostyrene, m-bromostyrene, ο-chlorostyrene,
p-chlorostyrene, m-chlorostyrene, vinyltoluene, vinylxylene,
fluorostyrene, and vinylnaphthalene, 5 preferably one or more
selected from the group consisting of styrene and α-methyl
styrene, more preferably styrene. In this case, due to proper
fluidity, processability and mechanical properties, such as
impact resistance, may be excellent.
10 [58] In this description, the derivative is a compound
produced by substituting a hydrogen atom or an atomic group
of an original compound with another atom or atomic group,
for example, refers to a compound produced by substitution
with a halogen or an alkyl group.
15 [59]
[60] For example, the emulsifier may include one or more
selected from the group consisting of allyl aryl sulfonates,
alkali methyl alkyl sulfonates, sulfonated alkyl esters,
fatty acid soap, and rosin acid alkali salts. In this case,
20 polymerization stability may be excellent.
18
[61] For example, the molecular weight modifier may
include one or more selected from the group consisting of tdodecyl
mercaptan, n-dodecyl mercaptan, n-octyl mercaptan,
and carbon tetrachloride, preferably t-dodecyl mercaptan.
[62] For example, the initiator 5 may be a water-soluble
persulfuric acid polymerization initiator, a fat-soluble
polymerization initiator, or an oxidation-reduction catalyst
system. For example, the water-soluble persulfuric acid
polymerization initiator may include one or more selected
10 from the group consisting of potassium persulfate, sodium
persulfate, and ammonium persulfate, and the fat-soluble
polymerization initiator may include one or more selected
from the group consisting of cumene hydroperoxide,
diisopropyl benzene hydroperoxide, azobis iso butyronitrile,
15 t-butyl hydroperoxide, paramethane hydroperoxide, and
benzoylperoxide.
[63] For example, latex prepared by emulsion
polymerization may be coagulated using a coagulant such as
sulfuric acid, MgSO4, CaCl2, or Al2(SO4)3, and then the
20 coagulated latex may be aged, dehydrated, and dried to obtain
19
powdered latex.
[64] For example, when the graft copolymer (A) is prepared,
an oxidation-reduction catalyst may be further included. For
example, the oxidation-reduction catalyst may include one or
more selected from the 5 group consisting of sodium
formaldehyde sulfoxylate, sodium ethylenediamine tetraacetate,
ferrous sulfate, dextrose, sodium pyrrolate, and sodium
sulfite, without being limited thereto. Oxidation-reduction
catalysts commonly used when ABS-based graft copolymers are
10 prepared may be used in the present invention, without
particular limitation.
[65]
[66] Other additives such as electrolytes not specifically
mentioned in the present description may be appropriately
15 selected when necessary. The additives may be used within a
range commonly applied in the preparation of vinyl cyanide
compound-conjugated diene rubber-aromatic vinyl compound
graft copolymer latex, without particular limitation.
[67]
20 [68] In the method of preparing the graft copolymer, other
20
reaction conditions, such as reaction time, reaction
temperature, pressure, and time of input of reactants, other
than the above-mentioned conditions, may be appropriately
selected and used without particular limitation as long as
the other reaction conditions 5 are commonly used in the art to
which the present invention pertains.

【CLAIMS】
【Claim 1】
A thermoplastic resin composition, comprising:
20 to 40 % by weight 5 of a vinyl cyanide compoundconjugated
diene rubber-aromatic vinyl compound graft
copolymer (A);
10 to 35 % by weight of an α-methyl styrene-vinyl
cyanide compound-aromatic vinyl compound copolymer (B);
10 5 to 30 % by weight of an aromatic vinyl compound-vinyl
cyanide compound copolymer (C);
23 to 47 % by weight of a polycarbonate resin (D); and
3 to 17 % by weight of a polyester resin (E),
wherein a weight of the copolymer (B) is greater than
15 or equal to a weight of the copolymer (C), and a weight ratio
of the polycarbonate resin (D) to the polyester resin (E) is
2:1 to 6:1.
【Claim 2】
50
The thermoplastic resin composition according to claim
1, wherein, when a specimen having a size of 200 mm × 12.7 mm
× 3.2 mm is fixed to a curved jig having a strain of 1.1 %, 1
cc of thinner is applied thereto, and then time at which
cracks occur on a surface 5 of the specimen is measured, the
thermoplastic resin composition has a chemical resistance of
600 seconds or more.
【Claim 3】
10 The thermoplastic resin composition according to claim
1, wherein the graft copolymer (A) comprises 50 to 80 % by
weight of conjugated diene rubber, 5 to 20 % by weight of a
vinyl cyanide compound, and 10 to 40 % by weight of an
aromatic vinyl compound.
15
【Claim 4】
The thermoplastic resin composition according to claim
1, wherein the conjugated diene rubber has an average
particle diameter of 2,000 to 5,000 Å.
20
51
【Claim 5】
The thermoplastic resin composition according to claim
1, wherein the copolymer (B) comprises 50 to 80 % by weight
of α-methyl styrene, 10 to 30 % by weight of a vinyl cyanide
compound, and 5 to 25 5 % by weight of an aromatic vinyl
compound (except for α-methyl styrene).
【Claim 6】
The thermoplastic resin composition according to claim
10 1, wherein the copolymer (C) comprises 20 to 40 % by weight
of a vinyl cyanide compound and 60 to 80 % by weight of an
aromatic vinyl compound.
【Claim 7】
15 The thermoplastic resin composition according to claim
1, wherein the polycarbonate resin (D) comprises one or more
selected from the group consisting of a linear polycarbonate
resin, a branched polycarbonate resin, and a polyester
carbonate copolymer resin.
20
52
【Claim 8】
The thermoplastic resin composition according to claim
1, wherein the polycarbonate resin (D) has a melt index of 10
g/10 min or more as measured at 300 °C under a load of 1.2 kg
5 according to ASTM D1238.
【Claim 9】
The thermoplastic resin composition according to claim
1, wherein the resin (D) has a weight average molecular
10 weight of 15,000 to 40,000 g/mol.
【Claim 10】
The thermoplastic resin composition according to claim
1, wherein the polyester resin (E) comprises one or more
15 selected from the group consisting of polyethylene adipate
(PEA), polybutylene succinate (PBS), polyethylene
terephthalate (PET), polybutylene terephthalate (PBT),
polytrimethylene terephthalate (PTT), and polyethylene
naphthalate (PEN).
20
53
【Claim 11】
The thermoplastic resin composition according to claim
1, wherein the polyester resin (E) has an intrinsic viscosity
of 0.5 to 2 dl/g as measured at 20 °C using methylene
5 chloride as a solvent.
【Claim 12】
The thermoplastic resin composition according to claim
1, wherein the thermoplastic resin composition has a melt
10 index of 55.0 g/10 min or more as measure at 250 °C under a
load of 10 kg according to ASTM D1238.
【Claim 13】
A method of preparing a thermoplastic resin
15 composition, comprising a step of kneading and extruding 20
to 40 % by weight of a vinyl cyanide compound-conjugated
diene rubber-aromatic vinyl compound graft copolymer (A), 10
to 35 % by weight of an α-methyl styrene-vinyl cyanide
compound-aromatic vinyl compound copolymer (B), 5 to 30 % by
20 weight of an aromatic vinyl compound-vinyl cyanide compound
54
copolymer (C), 23 to 47 % by weight of a polycarbonate resin
(D), and 3 to 17 % by weight of a polyester resin (E) at 200
to 280 °C,
wherein a weight of the copolymer (B) is greater than
or equal to a weight of the copolymer 5 (C), and a weight ratio
of the polycarbonate resin (D) to the polyester resin (E) is
2:1 to 6:1.
【Claim 14】
10 A molded article, comprising the thermoplastic resin
composition according to any one of claims 1 to 12.