【Technical Field】
[1] [Cross-Reference to Related Application]
[2] This application claims priority to Korean Patent
Application No. 10-2021-0009291, filed on January 22, 2021 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 that does not contain phthalate-based compounds,
which are environmental hormones harmful to the human body;
does not emit toxic gases in case of fire; has processability
equal or superior to that of a conventional PVC resin, which
20 is a material for calendering and T-die extrusion; has
2
excellent mechanical properties, such as impact strength,
tensile strength, and elongation, surface hardness, and heat
resistance; and is capable of preventing occurrence of
whitening during bending due to excellent non-whitening
5 properties, a method of preparing the thermoplastic resin
composition, and a molded article including the thermoplastic
resin composition.
【Background Art】
10 [4] Polyvinyl chloride (hereinafter referred to as "PVC")
resins and t-polymethylmethacrylate (hereinafter referred to
as "t-PMMA") resins are mainly used in the manufacture of
decorative sheets through T-die extrusion processing and
calendering.
15 [5] A PVC resin is a homopolymer of vinyl chloride and a
copolymer containing 50 % by weight or more of vinyl chloride,
and is one of five general-purpose thermoplastic resins
prepared by suspension polymerization or emulsion
polymerization. When preparing a polyvinyl chloride resin by
20 suspension polymerization, plasticizers, stabilizers, fillers,
3
pigments, and auxiliary materials with special functions are
added. The polyvinyl chloride resin prepared in this way is
used in the manufacture of various products such as films,
sheets, electric wires, and pipes through various processing
5 methods. However, since chlorine gas and hydrogen chloride
gas are generated during combustion of PVC resins, harmful
gases are generated in case of fire. In addition, phthalatebased compounds are used as plasticizers to impart flexibility
to PVC resins. The phthalate-based compounds are known as
10 environmental hormones that are harmful to the human body.
[6] In addition, a t-PMMA resin is a resin developed to
increase the low brittleness of a PMMA resin, and is prepared
by compounding a polymer obtained by polymerizing acrylic
rubber as a core and methyl methacrylate as a shell and a
15 polymethylmethacrylate resin. The t-PMMA resins have
excellent surface hardness and colorability, but the use
thereof is limited due to low impact strength at room
temperature and low temperature.
[7] To solve these problems, research on materials
20 capable of replacing PVC resins and t-PMMA resins is being
4
actively conducted. Thereamong, acrylonitrile-styreneacrylate resins (hereinafter referred to as "ASA resins")
have excellent weather resistance, light resistance,
colorability, chemical resistance, and impact resistance, and
5 thus, are used in various fields such as automobiles, building
materials, and miscellaneous goods. In particular, compared
to PVC resins, ASA resins have excellent processing stability
and do not contain heavy metal components, so ASA resins are
in the spotlight as eco-friendly materials.
10 [8] 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, a PVC resin,
15 or an iron plate, with an ASA resin. These finishing
materials are mainly manufactured in the form of films.
Depending on the shape of a substrate, the finishing material
is manufactured into a final product through a bending process
such as bending or folding. However, due to the
20 characteristics of a thermoplastic ASA resin, when the above-
5
described finishing treatment is applied at room temperature,
whitening occurs in folded portions, resulting in loss of
original color and deterioration of appearance and aesthetics.
[9] Therefore, there is a need to develop a thermoplastic
5 resin composition that is applicable to various processing
such as T-die extrusion processing and calender processing,
is eco-friendly, and does not cause whitening after bending
processing.
[10]
10 [11] [Related Art Documents]
[12] [Patent Documents]
[13] Japanese Patent No. 1995-033470
【Disclosure】
15 【Technical Problem】
[14] Therefore, the present invention has been made in
view of the above problems, and it is one object of the
present invention to provide a thermoplastic resin
composition that does not contain phthalate-based compounds,
20 which are environmental hormones harmful to the human body;
6
does not emit toxic gases in case of fire; has processability
equal or superior to that of a PVC resin during calendering
and T-die extrusion; has excellent mechanical properties,
such as impact strength, tensile strength, and elongation,
5 surface hardness, and heat resistance; and is capable of
preventing occurrence of whitening during bending due to
excellent non-whitening properties.
[15] It is another object of the present invention to
provide a method of preparing the thermoplastic resin
10 composition.
[16] It is yet another object of the present invention to
provide a molded article manufactured using the thermoplastic
resin composition.
[17]
15 [18] The above and other objects can be accomplished by
the present invention described below.
【Technical Solution】
[19] In accordance with one aspect of the present invention,
20 provided is a thermoplastic resin composition including 25 to
7
75 % by weight of an alkyl acrylate-aromatic vinyl compoundvinyl cyanide compound graft copolymer (A) containing alkyl
acrylate rubber having an average particle diameter of 50 to
120 nm; 18 to 47 % by weight of an aromatic vinyl compound5 vinyl cyanide compound copolymer (B) having a weight average
molecular weight of 70,000 to 150,000 g/mol; and 3 to 28 % by
weight of an aromatic vinyl compound-vinyl cyanide compound
copolymer (C) having a weight average molecular weight of
greater than 150,000 g/mol and less than or equal to 250,000
10 g/mol, wherein the thermoplastic resin composition has an
alkyl acrylate coverage value (X) of 67 % or more as
calculated by Equation 1 below:
[20] [Equation 1]
[21] X = {(G-Y)/Y} × 100,
15 [22] 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
based on a total weight of the thermoplastic resin composition.
[23]
20 [24] In addition, the present invention may provide a
8
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; 18 to
5 47 % by weight of an aromatic vinyl compound-vinyl cyanide
compound copolymer (B) having a weight average molecular
weight of 70,000 to 150,000 g/mol; and 3 to 28 % by weight of
an aromatic vinyl compound-vinyl cyanide compound copolymer
(C) having a weight average molecular weight of greater than
10 150,000 g/mol and less than or equal to 250,000 g/mol, wherein
the thermoplastic resin composition has a heat deflection
temperature of 71 °C or higher as measured under a load of
18.6 kgf according to ASTM D648.
[25]
15 [26] 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 copolymer (A) containing alkyl acrylate rubber
having an average particle diameter of 50 to 120 nm; 18 to
20 47 % by weight of an aromatic vinyl compound-vinyl cyanide
9
compound copolymer (B) having a weight average molecular
weight of 70,000 to 150,000 g/mol; and 3 to 28 % by weight of
an aromatic vinyl compound-vinyl cyanide compound copolymer
(C) having a weight average molecular weight of greater than
5 150,000 g/mol and less than or equal to 250,000 g/mol, wherein
the graft copolymer (A) includes 20 to 60 % by weight of an
alkyl acrylate and 40 to 80 % by weight of an aromatic vinyl
compound-vinyl cyanide compound copolymer.
[27]
10 [28] 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, at 200 to 300 °C and 100 to 500 rpm, 25 to 75 % by
weight of an alkyl acrylate-aromatic vinyl compound-vinyl
15 cyanide compound graft copolymer (A) containing alkyl
acrylate rubber having an average particle diameter of 50 to
120 nm, 18 to 47 % by weight of an aromatic vinyl compoundvinyl cyanide compound copolymer (B) having a weight average
molecular weight of 70,000 to 150,000 g/mol, and 3 to 28 % by
20 weight of an aromatic vinyl compound-vinyl cyanide compound
10
copolymer (C) having a weight average molecular weight of
greater than 150,000 g/mol and less than or equal to 250,000
g/mol, wherein the thermoplastic resin composition has an
alkyl acrylate coverage value (X) of 67 % or more as
5 calculated by Equation 1 below:
[29] [Equation 1]
[30] X = {(G-Y)/Y} × 100,
[31] 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.
[32]
[33] In addition, the present invention may provide a
method of preparing a thermoplastic resin composition, the
15 method including kneading and extruding, at 200 to 300 °C and
100 to 500 rpm, 25 to 75 % by weight of an alkyl acrylatearomatic vinyl compound-vinyl cyanide compound graft
copolymer (A) containing alkyl acrylate rubber having an
average particle diameter of 50 to 120 nm, 18 to 47 % by
20 weight of an aromatic vinyl compound-vinyl cyanide compound
11
copolymer (B) having a weight average molecular weight of
70,000 to 150,000 g/mol, and 3 to 28 % by weight of an aromatic
vinyl compound-vinyl cyanide compound copolymer (C) having a
weight average molecular weight of greater than 150,000 g/mol
5 and less than or equal to 250,000 g/mol, wherein the
thermoplastic resin composition has a heat deflection
temperature of 71 °C or higher as measured under a load of
18.6 kgf according to ASTM D648.
[34]
10 [35] In addition, the present invention may provide 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 acrylatearomatic vinyl compound-vinyl cyanide compound graft
15 copolymer (A) containing alkyl acrylate rubber having an
average particle diameter of 50 to 120 nm, 18 to 47 % by
weight of an aromatic vinyl compound-vinyl cyanide compound
copolymer (B) having a weight average molecular weight of
70,000 to 150,000 g/mol, and 3 to 28 % by weight of an aromatic
20 vinyl compound-vinyl cyanide compound copolymer (C) having a
12
weight average molecular weight of greater than 150,000 g/mol
and less than or equal to 250,000 g/mol, wherein the graft
copolymer (A) includes 20 to 60 % by weight of an alkyl
acrylate and 40 to 80 % by weight of an aromatic vinyl
5 compound-vinyl cyanide compound copolymer.
[36]
[37] In accordance with yet another aspect of the present
invention, provided is a molded article including the
thermoplastic resin composition.
10
【Advantageous effects】
[38] According to the present invention, the present
invention has an effect of providing a thermoplastic resin
composition that does not contain phthalate-based compounds,
15 which are environmental hormones harmful to the human body;
does not emit toxic gases in case of fire; has processability
equal or superior to that of a PVC resin, which is a material
for calendering and T-die extrusion; has excellent mechanical
properties, such as impact strength, tensile strength, and
20 elongation, surface hardness, and heat resistance; and is
13
capable of preventing occurrence of whitening during bending
due to excellent non-whitening properties, a method of
preparing the thermoplastic resin composition, and a molded
article including the thermoplastic resin composition.
5
【Description of Drawings】
[39] FIG.1 includes images taken after hitting, using a
Gardner impact tester, films manufactured in Example 2 (left
image) and Comparative Example 1 (right image) to check
10 whether whitening occurs.
【Best mode】
[40] Hereinafter, a thermoplastic resin composition, a
method of preparing the same, and a molded article including
15 the same according to the present invention will be described
in detail.
[41] The present inventors confirmed that, when an alkyl
acrylate-aromatic vinyl compound-vinyl cyanide compound graft
copolymer containing rubber having a predetermined average
20 particle diameter and two or more types of aromatic vinyl
14
compound-vinyl cyanide compound copolymers having different
weight average molecular weights were mixed in a predetermined
composition ratio, and the alkyl acrylate coverage value of
a thermoplastic resin composition was adjusted within a
5 predetermined range, the thermoplastic resin composition had
processability equal or superior to that of a PVC resin during
calendering and T-die extrusion, the mechanical properties,
surface hardness, and heat resistance of the thermoplastic
resin composition were improved, and the thermoplastic resin
10 composition had excellent non-whitening properties. Based on
these results, the present inventors conducted further
studies to complete the present invention.
[42]
[43] The thermoplastic resin composition of the present
15 invention will be described in detail as follows.
[44]
[45] The thermoplastic resin composition of the present
invention includes 25 to 75 % by weight of an alkyl acrylatearomatic vinyl compound-vinyl cyanide compound graft
20 copolymer (A) containing alkyl acrylate rubber having an
15
average particle diameter of 50 to 120 nm; 18 to 47 % by
weight of an aromatic vinyl compound-vinyl cyanide compound
copolymer (B) having a weight average molecular weight of
70,000 to 150,000 g/mol; and 3 to 28 % by weight of an aromatic
5 vinyl compound-vinyl cyanide compound copolymer (C) having a
weight average molecular weight of greater than 150,000 g/mol
and less than or equal to 250,000 g/mol, wherein the
thermoplastic resin composition has an alkyl acrylate
coverage value (X) of 67 % or more as calculated by Equation
10 1 below. In this case, the thermoplastic resin composition
has excellent processability during calendering and T-die
extrusion, has excellent mechanical properties, such as
impact strength, tensile strength, and elongation, surface
hardness, and heat resistance, and has excellent non15 whitening properties.
[46] [Equation 1]
[47] X = {(G-Y)/Y} × 100
[48] In Equation 1, G represents a gel content (wt%) based
on a total weight of the thermoplastic resin composition, and
20 Y represents the content (wt%) of an alkyl acrylate in the
16
gel based on a total weight of the thermoplastic resin
composition.
[49]
[50] Hereinafter, each component constituting the
5 thermoplastic resin composition of the present invention will
be described in detail.
[51]
[52] (A) Alkyl acrylate-aromatic vinyl compound-vinyl
cyanide compound graft copolymer
10 [53] 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 may have excellent impact strength and gloss.
15 [54] 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 particle size
analyzer (product name: Nicomp 380, manufacturer: PSS) in a
Gaussian mode. As a specific measurement example, a sample
20 may be prepared by diluting 0.1 g of latex (total solids
17
content: 35 to 50 wt%) 1,000 to 5,000-fold with distilled
water, and average particle diameter may be measured using
flow cells in an auto-dilution manner and in a mode of dynamic
light scattering/intensity 300 kHz/intensity-weight Gaussian
5 analysis. At this time, temperature may be set to 23 °C,
measurement wavelength may be set to 632.8 nm, and channel
width may be set to 10 μsec.
[55]
[56] For example, based on a total weight of the components
10 (A), (B), and (C), the graft copolymer (A) may be included in
an amount of 25 to 75 % by weight, preferably 30 to 70 % by
weight, more preferably 40 to 60 % by weight, still more
preferably 45 to 55 % by weight. Within this range, excellent
processability may be achieved during calendering and T-die
15 extrusion, and mechanical properties, such as impact strength,
tensile strength, and elongation, gloss, and surface hardness
may be excellent.
[57]
[58] For example, the graft copolymer (A) may include 20
20 to 60 % by weight of alkyl acrylate rubber (a-1) and 40 to
18
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
aromatic vinyl compound-vinyl cyanide compound copolymer (a5 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 hardness may
be excellent.
10 [59] 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.

【CLAIMS】
【Claim 1】
A thermoplastic resin composition, comprising:
5 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;
18 to 47 % by weight of an aromatic vinyl compound-vinyl
10 cyanide compound copolymer (B) having a weight average
molecular weight of 70,000 to 150,000 g/mol; and
3 to 28 % by weight of an aromatic vinyl compound-vinyl
cyanide compound copolymer (C) having a weight average
molecular weight of greater than 150,000 g/mol and less than
15 or equal to 250,000 g/mol,
wherein the thermoplastic resin composition has an
alkyl acrylate coverage value (X) of 67 % or more as
calculated by Equation 1 below:
[Equation 1]
20 X = {(G-Y)/Y} × 100,
74
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
based on a total weight of the thermoplastic resin
5 composition.
【Claim 2】
The thermoplastic resin composition according to claim
1, wherein the graft copolymer (A) comprises 20 to 60 % by
10 weight of alkyl acrylate rubber (a-1) and 40 to 80 % by weight
of an aromatic vinyl compound-vinyl cyanide compound
copolymer (a-2).
【Claim 3】
15 The thermoplastic resin composition according to claim
1, wherein the graft copolymer (A) has a grafting degree of
60 % or more as calculated by Equation 3 below:
[Equation 3]
Grafting degree (%) = [Weight (g) of grafted
20 monomers/Rubber weight (g)] × 100,
75
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
5 rubber weight (g) is a weight (g) of rubber components
theoretically added to graft copolymer powder.
【Claim 4】
The thermoplastic resin composition according to claim
10 1, wherein the aromatic vinyl compound-vinyl cyanide compound
copolymer (B) and the aromatic vinyl compound-vinyl cyanide
compound copolymer (C) each independently comprise 55 to 85 %
by weight of an aromatic vinyl compound and 15 to 45 % by
weight of a vinyl cyanide compound.
15
【Claim 5】
The thermoplastic resin composition according to claim
1, wherein the thermoplastic resin composition comprises one
or more selected from the group consisting of a heat
20 stabilizer, a light stabilizer, a dye, a pigment, a colorant,
76
a lubricant, a release agent, an antistatic agent, an
antibacterial agent, a processing aid, a metal deactivator,
a flame retardant, a smoke suppressant, an anti-drip agent,
an anti-friction agent, and an anti-wear agent.
5
【Claim 6】
The thermoplastic resin composition according to claim
1, wherein the thermoplastic resin composition has a melt
index (220 °C, 10 kg) of 1.8 to 21 g/10 min as measured
10 according to ASTM D1238.
【Claim 7】
The thermoplastic resin composition according to claim
1, wherein the thermoplastic resin composition has an Izod
15 impact strength (specimen thickness: 1/4", room temperature)
of 3 kgf·cm/cm or more as measured according to ASTM D256.
【Claim 8】
The thermoplastic resin composition according to claim
20 1, wherein, when a 1 kg weight is vertically dropped onto an
77
extruded film having dimensions of 0.15 mm × 10 cm × 10 cm 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
5 according to ASTM D1003, and a difference in the haze values
is calculated, the thermoplastic resin composition has a haze
difference (△Haze) of 5.5 or less.
【Claim 9】
10 The thermoplastic resin composition according to claim
1, wherein, when a sheet having a thickness of 0.15 mm is
manufactured using a T-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
15 both ends of the sheet, and thickness deviation is calculated
based on a difference between maximum and minimum thicknesses,
the thermoplastic resin composition has a thickness deviation
of 0.06 mm or less.
20 【Claim 10】
78
The thermoplastic resin composition according to claim
1, wherein, when a sheet having dimensions of 15 cm × 15 cm
in length and width is manufactured through calendering using
a roll mill machine, thickness is measured at 10 or more
5 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 thicknesses,
the thermoplastic resin composition has a thickness deviation
of 0.09 mm or less.
10
【Claim 11】
The thermoplastic resin composition according to claim
1, wherein the thermoplastic resin composition has a heat
deflection temperature of 71 °C or higher as measured under
15 a load of 18.6 kgf according to ASTM D648.
【Claim 12】
A method of preparing a thermoplastic resin
composition, comprising kneading and extruding, at 200 to
20 300 °C and 100 to 500 rpm, 25 to 75 % by weight of an alkyl
79
acrylate-aromatic vinyl compound-vinyl cyanide compound graft
copolymer (A) containing alkyl acrylate rubber having an
average particle diameter of 50 to 120 nm, 18 to 47 % by
weight of an aromatic vinyl compound-vinyl cyanide compound
5 copolymer (B) having a weight average molecular weight of
70,000 to 150,000 g/mol, and 3 to 28 % by weight of an aromatic
vinyl compound-vinyl cyanide compound copolymer (C) having a
weight average molecular weight of greater than 150,000 g/mol
and less than or equal to 250,000 g/mol,
10 wherein the thermoplastic resin composition has an
alkyl acrylate coverage value (X) of 67 % or more as
calculated by Equation 1 below:
[Equation 1]
X = {(G-Y)/Y} × 100,
15 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
based on a total weight of the thermoplastic resin
composition.
20
80
【Claim 13】
A molded article, comprising the thermoplastic resin
composition according to any one of claims 1 to 11.
5 【Claim 14】
The molded article according to claim 13, wherein the
molded article is an injection-molded article, a calenderingmolded article, or an extrusion-molded article.