U.S. patent application number 15/510646 was filed with the patent office on 2018-08-16 for thermoplastic resin composition and method of preparing the same.
The applicant listed for this patent is LG CHEM, LTD.. Invention is credited to Jeong Su CHOI, Seok Goo JANG, Ho Hoon KIM, Roo Da LEE, Won Seok LEE, Sang Hoo PARK, Hyung Seop SHIM, Keun Hoon YOO.
Application Number | 20180230301 15/510646 |
Document ID | / |
Family ID | 58188080 |
Filed Date | 2018-08-16 |
United States Patent
Application |
20180230301 |
Kind Code |
A1 |
CHOI; Jeong Su ; et
al. |
August 16, 2018 |
THERMOPLASTIC RESIN COMPOSITION AND METHOD OF PREPARING THE
SAME
Abstract
The present disclosure relates to a thermoplastic resin
composition and a method of preparing the same. In accordance with
the present disclosure, a thermoplastic resin composition having
superior property balance, such as processability, chemical
resistance, heat stability, and impact resistance, and excellent
transparency, and a method of preparing the same are provided.
Inventors: |
CHOI; Jeong Su; (Daejeon,
KR) ; YOO; Keun Hoon; (Daejeon, KR) ; LEE; Won
Seok; (Daejeon, KR) ; JANG; Seok Goo;
(Daejeon, KR) ; LEE; Roo Da; (Daejeon, KR)
; PARK; Sang Hoo; (Daejeon, KR) ; KIM; Ho
Hoon; (Daejeon, KR) ; SHIM; Hyung Seop;
(Daejeon, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
LG CHEM, LTD. |
Seoul |
|
KR |
|
|
Family ID: |
58188080 |
Appl. No.: |
15/510646 |
Filed: |
July 29, 2016 |
PCT Filed: |
July 29, 2016 |
PCT NO: |
PCT/KR2016/008350 |
371 Date: |
March 10, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C08F 220/14 20130101;
C08F 279/02 20130101; C08L 2205/03 20130101; C08L 2205/06 20130101;
C08L 2201/10 20130101; C08L 33/20 20130101; C08L 2205/025 20130101;
C08L 51/04 20130101; C08L 2201/08 20130101; C08F 279/02 20130101;
C08F 220/14 20130101; C08F 279/02 20130101; C08F 212/08 20130101;
C08F 279/02 20130101; C08F 220/44 20130101; C08L 51/04 20130101;
C08L 51/04 20130101; C08L 33/20 20130101; C08F 220/14 20130101;
C08F 212/08 20130101; C08F 220/44 20130101 |
International
Class: |
C08L 33/20 20060101
C08L033/20 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 31, 2015 |
KR |
10-2015-0123006 |
Claims
1. A thermoplastic resin composition, comprising: (A-1) a graft
copolymer formed by graft-copolymerizing (a-1) a conjugated diene
rubber latex having a weight average particle diameter of 500 .ANG.
to 2,000 .ANG. with (b-1) a methacrylic acid alkyl ester compound
or an acrylic acid alkyl ester compound, (c-1) an aromatic vinyl
compound, and (d-1) a vinyl cyan compound; (A-2) a graft copolymer
formed by graft-copolymerizing (a-2) a conjugated diene rubber
latex having a weight average particle diameter of 2,500 .ANG. to
5,000 .ANG. with (b-2) a methacrylic acid alkyl ester compound or
an acrylic acid alkyl ester compound, (c-2) an aromatic vinyl
compound, and (d-2) a vinyl cyan compound; and (B) a copolymer
formed by polymerizing i) a methacrylic acid alkyl ester compound
or an acrylic acid alkyl ester compound, ii) an aromatic vinyl
compound, and iii) a vinyl cyan compound, wherein the thermoplastic
resin composition satisfies Mathematical Equation 1 below:
0.75.ltoreq.X.sub.a-1/X.sub.a-2.ltoreq.4 [Mathematical Equation 1]
wherein X.sub.a-1 refers to a weight of (a-1) the conjugated diene
rubber latex (based on solid content) and X.sub.a-2 refers to a
weight of (a-2) the conjugated diene rubber latex (based on solid
content), wherein a refractive index difference between (A-1) the
graft copolymer and (A-2) the graft copolymer is 0.01 or less, and
a refractive index difference between (A-1) the graft copolymer or
(A-2) the graft copolymer and (B) the copolymer is 0.01 or
less.
2. The thermoplastic resin composition according to claim 1,
wherein the thermoplastic resin composition has a haze of 1.3 or
less and an impact strength of 10 kgcm/cm or more.
3. The thermoplastic resin composition according to claim 1,
wherein the thermoplastic resin composition comprises 10 to 60% by
weight of (A-1) the graft copolymer, 10 to 50% by weight of (A-2)
the graft copolymer, and 30 to 80% by weight of (B) the copolymer,
wherein (A-1)+(A-2)+(B)=100% by weight.
4. The thermoplastic resin composition according to claim 1,
wherein the thermoplastic resin composition comprises 5 to 30% by
weight of (a-1) the conjugated diene rubber latex.
5. The thermoplastic resin composition according to claim 1,
wherein the thermoplastic resin composition comprises 5 to 20% by
weight of (a-2) the conjugated diene rubber latex.
6. The thermoplastic resin composition according to claim 1,
wherein the thermoplastic resin composition comprises a methacrylic
acid alkyl ester compound and acrylic acid alkyl ester compound in
a total amount of 20 to 70% by weight.
7. The thermoplastic resin composition according to claim 1,
wherein the methacrylic acid alkyl ester compound is methyl
methacrylate.
8. The thermoplastic resin composition according to claim 1,
wherein the thermoplastic resin composition comprises 10 to 30% by
weight of an aromatic vinyl compound.
9. The thermoplastic resin composition according to claim 1,
wherein the aromatic vinyl compound is one or more selected from
the group consisting of styrene, .alpha.-methylstyrene, o-ethyl
styrene, p-ethyl styrene, and vinyltoluene.
10. The thermoplastic resin composition according to claim 1,
wherein the thermoplastic resin composition comprises 0 to 10% by
weight of a vinyl cyan compound.
11. The thermoplastic resin composition according to claim 1,
wherein the vinyl cyan compound is one or more selected from the
group consisting of acrylonitrile, methacrylonitrile, and
ethacrylonitrile.
12. The thermoplastic resin composition according to claim 1,
wherein (A-1) the graft copolymer is formed by polymerizing 20 to
70% by weight (based on solid content) of (a-1) the conjugated
diene rubber latex with 20 to 60% by weight of (b) a methacrylic
acid alkyl ester compound or acrylic acid alkyl ester compound, 7
to 30% by weight of (c) an aromatic vinyl compound, and 0 to 10% by
weight of (d) a vinyl cyan compound.
13. The thermoplastic resin composition according to claim 1,
wherein (A-2) the graft copolymer is formed by polymerizing 20 to
70% by weight (based on solid content) of (a-2) the conjugated
diene rubber latex with 20 to 60% by weight of (b) a methacrylic
acid alkyl ester compound or acrylic acid alkyl ester compound, 7
to 30% by weight of (c) an aromatic vinyl compound, and 0 to 10% by
weight of (d) a vinyl cyan compound.
14. The thermoplastic resin composition according to claim 1,
wherein (B) the copolymer is formed by polymerizing 30 to 75% by
weight of a methacrylic acid alkyl ester compound or acrylic acid
alkyl ester compound, 15 to 40% by weight of an aromatic vinyl
compound, and 0 to 20% by weight of a vinyl cyan compound.
15. The thermoplastic resin composition according to claim 1,
wherein a refractive index difference between the conjugated diene
rubber latex and a polymer grafted to the conjugated diene rubber
latex is 0.01 or less.
16. The thermoplastic resin composition according to claim 1,
wherein a refractive index difference between (A-1) the graft
copolymer or (A-2) the graft copolymer and (B) the copolymer is
0.01 or less.
17. The thermoplastic resin composition according to claim 1,
wherein the thermoplastic resin composition further comprises one
or more selected from the group consisting of a thermal stabilizer,
a UV stabilizer, and a lubricant and antioxidant.
18. A method of preparing a thermoplastic resin composition, the
method comprising a step of melt-kneading (A-1) a graft copolymer
formed by graft-copolymerizing (a-1) a conjugated diene rubber
latex having a weight average particle diameter of 500 .ANG. to
2,000 .ANG. with (b-1) a methacrylic acid alkyl ester compound or
an acrylic acid alkyl ester compound, (c-1) an aromatic vinyl
compound, and (d-1) a vinyl cyan compound; (A-2) a graft copolymer
formed by graft-copolymerizing (a-2) a conjugated diene rubber
latex having a weight average particle diameter of 2,500 .ANG. to
5,000 .ANG. with (b-2) a methacrylic acid alkyl ester compound or
an acrylic acid alkyl ester compound, (c-2) an aromatic vinyl
compound, and (d-2) a vinyl cyan compound; and (B) a copolymer
formed by bulk-polymerizing i) a methacrylic acid alkyl ester
compound or an acrylic acid alkyl ester compound, ii) an aromatic
vinyl compound, and iii) a vinyl cyan compound, wherein the
thermoplastic resin composition satisfies Mathematical Equation 1
below: 0.75.ltoreq.X.sub.a-1/X.sub.a-2.ltoreq.4 [Mathematical
Equation 1] wherein X.sub.a-1 refers to a weight of (a-1) the
conjugated diene rubber latex (based on solid content) and
X.sub.a-2 refers to a weight of (a-2) the conjugated diene rubber
latex (based on solid content), wherein a refractive index
difference between (A-1) the graft copolymer and (A-2) the graft
copolymer is 0.01 or less, and a refractive index difference
between (A-1) the graft copolymer or (A-2) the graft copolymer and
(B) the copolymer is 0.01 or less.
19. A molded article manufactured from the thermoplastic resin
composition according to claim 1.
20. The molded article according to claim 19, wherein the molded
article is a washing machine cover, a cleaner dust collector, a
toy, a game machine housing, a home appliance transparent window,
or an office equipment transparent window.
Description
CROSS-REFERENCE TO RELATED APPLICATION(S)
[0001] This application claims the priority benefit of Korean
Patent Application No. 10-2015-0123006, filed on Aug. 31, 2015 in
the Korean Intellectual Property Office, the disclosure of which is
incorporated herein by reference.
TECHNICAL FIELD
[0002] The present disclosure relates to a thermoplastic resin
composition having superior transparency and impact resistance and
a method of preparing the same, and more particularly to a
thermoplastic resin composition having superior property balance,
such as processability, chemical resistance, heat stability, and
impact resistance, and excellent transparency, a method of
preparing the same, and the like.
BACKGROUND ART
[0003] Recently, studies into impartation of high functionality,
such as high transparency, to materials used in product models, is
actively underway as the industry has advanced and the life has
become diverse.
[0004] For example, research into giving transparency to existing
materials, such as washing machine covers through which laundry is
shown, cleaner dust collectors by which how much dust is collected
can be checked, toys, game machine housings, and transparent
windows of home appliances, is intensively underway.
[0005] An acrylonitrile-butadiene-styrene copolymer (ABS) resin,
which has been widely used in these products, has excellent
properties such as excellent impact resistance, chemical
resistance, processability, and surface gloss. However, since this
resin is inherently opaque, application thereof to cases requiring
transparency is limited.
[0006] In general, a polycarbonate (PC) resin, a polymethyl
methacrylate (PMMA) resin, a polystyrene (PS) resin, a
polyacrylonitrile-styrene (SAN) resin, and the like are used as a
transparent resin.
[0007] However, while such a polycarbonate (PC) resin has superior
impact strength, transparency, and the like, processability thereof
is poor, thereby making it difficult to produce complicated
products. While a polymethyl methacrylate (PMMA) resin has superior
optical properties, but impact resistance and chemical resistance
thereof are very poor. In addition, a polystyrene (PS) resin, a
polyacrylonitrile-styrene (SAN) resin, and the like have very poor
impact resistance and chemical resistance.
[0008] U.S. Pat. No. 4,767,833, Japanese Patent Application
Publication No. 1999-147020, European Patent No. 703,252, and
Japanese Patent Application Publication No. 1996-199008 disclose a
method of introducing an acrylic acid alkyl ester or methacrylic
acid alkyl ester compound to an ABS resin having superior impact
resistance, chemical resistance, processability, and the like to
impart transparency. However, since the imparted transparency has a
limitation, application thereof to products, which have a haze of
greater than 2.0 and thus in which a PMMA resin, a PC resin, an SAN
resin, or the like is used, thick injection-molded products, or
products requiring high transparency is limited.
[0009] Therefore, there is an urgent need to develop a transparent
resin having further improved transparency to provide transparency
shown in products using a PC resin, an SAN resin, and the like and
improved properties such as improved impact strength.
DISCLOSURE
Technical Problem
[0010] 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 having superior
property balance, such as processability, chemical resistance, heat
stability, and impact resistance, and excellent transparency, a
method of preparing the same, and the like.
[0011] The above and other objects of the present disclosure can be
accomplished by the present invention described below.
Technical Solution
[0012] In accordance with an aspect of the present invention, the
above and other objects can be accomplished by the provision of a
thermoplastic resin composition, including: (A-1) a graft copolymer
formed by graft-copolymerizing (a-1) a conjugated diene rubber
latex having a weight average particle diameter of 500 .ANG. to
2,000 .ANG. with (b-1) a methacrylic acid alkyl ester compound or
an acrylic acid alkyl ester compound, (c-1) an aromatic vinyl
compound, and (d-1) a vinyl cyan compound; (A-2) a graft copolymer
formed by graft-copolymerizing (a-2) a conjugated diene rubber
latex having a weight average particle diameter of 2,500 .ANG. to
5,000 .ANG. with (b-2) a methacrylic acid alkyl ester compound or
an acrylic acid alkyl ester compound, (c-2) an aromatic vinyl
compound, and (d-2) a vinyl cyan compound; and (B) a copolymer
formed by polymerizing i) a methacrylic acid alkyl ester compound
or an acrylic acid alkyl ester compound, ii) an aromatic vinyl
compound, and iii) a vinyl cyan compound, wherein the thermoplastic
resin composition satisfies Mathematical Equation 1 below:
0.75.ltoreq.X.sub.a-1/X.sub.a-2.ltoreq.4 [Mathematical Equation
1]
[0013] wherein X.sub.a-1 refers to the weight of (a-1) the
conjugated diene rubber latex (based on solid content) and
X.sub.a-2 refers to the weight of (a-2) the conjugated diene rubber
latex (based on solid content), wherein a refractive index
difference between (A-1) the graft copolymer and (A-2) the graft
copolymer is 0.01 or less, and a refractive index difference
between (A-1) the graft copolymer or (A-2) the graft copolymer and
(B) the copolymer is 0.01 or less.
[0014] The thermoplastic resin composition has, for example, a haze
of 1.3 or less and an impact strength of 10 kgcm/cm or more.
[0015] The thermoplastic resin composition may include, for
example, 10 to 60% by weight of (A-1) the graft copolymer, 10 to
50% by weight of (A-2) the graft copolymer, and 30 to 80% by weight
of (B) the copolymer, wherein (A-1)+(A-2)+(B)=100% by weight.
[0016] The thermoplastic resin composition may include, for
example, 5 to 30% by weight (based on solid content) of (a-1) the
conjugated diene rubber latex.
[0017] The thermoplastic resin composition may include, for
example, 5 to 20% by weight (based on solid content) of (a-2) the
conjugated diene rubber latex.
[0018] The thermoplastic resin composition may include, for
example, a methacrylic acid alkyl ester compound and acrylic acid
alkyl ester compound in a total amount of 20 to 70% by weight.
[0019] The methacrylic acid alkyl ester compound may be, for
example, methyl methacrylate.
[0020] The thermoplastic resin composition may include, for
example, 10 to 30% by weight of an aromatic vinyl compound.
[0021] The aromatic vinyl compound may be, for example, one or more
selected from the group consisting of styrene,
.alpha.-methylstyrene, o-ethylstyrene, p-ethylstyrene, and
vinyltoluene.
[0022] The thermoplastic resin composition may include, for
example, 0 to 10% by weight of a vinyl cyan compound.
[0023] The vinyl cyan compound may be, for example, one or more
selected from the group consisting of acrylonitrile,
methacrylonitrile, and ethacrylonitrile.
[0024] (A-1) The graft copolymer may be a copolymer formed by, for
example, polymerizing 20 to 70% by weight (based on solid content)
of (a-1) the conjugated diene rubber latex with 20 to 60% by weight
of (b) a methacrylic acid alkyl ester compound or acrylic acid
alkyl ester compound, 7 to 30% by weight of (c) an aromatic vinyl
compound, and 0 to 10% by weight of (d) a vinyl cyan compound.
[0025] (A-2) The graft copolymer may be a copolymer formed by, for
example, polymerizing 20 to 70% by weight (based on solid content)
of (a-2) the conjugated diene rubber latex with 20 to 60% by weight
of (b) a methacrylic acid alkyl ester compound or acrylic acid
alkyl ester compound, 7 to 30% by weight of (c) an aromatic vinyl
compound, and 0 to 10% by weight of (d) a vinyl cyan compound.
[0026] (B) The copolymer may be a copolymer formed by, for example,
polymerizing 30 to 75% by weight of a methacrylic acid alkyl ester
compound or acrylic acid alkyl ester compound, 15 to 40% by weight
of an aromatic vinyl compound, and 0 to 20% by weight of a vinyl
cyan compound.
[0027] A refractive index difference between the conjugated diene
rubber latex and a polymer grafted to the conjugated diene rubber
latex may be, for example, 0.01 or less.
[0028] A refractive index difference between (a-1) the conjugated
diene rubber latex and (a-2) the conjugated diene rubber latex may
be, for example, 0.01 or less.
[0029] A refractive index difference between (A-1) the graft
copolymer or (A-2) the graft copolymer and (B) the copolymer may
be, for example, 0.01 or less.
[0030] The thermoplastic resin composition may further include, for
example, one or more selected from the group consisting of a
thermal stabilizer, a UV stabilizer, and a lubricant and
antioxidant.
[0031] In accordance with another aspect of the present invention,
there is provided a method of preparing a thermoplastic resin
composition, the method including a step of melt-kneading (A-1) a
graft copolymer formed by graft-copolymerizing (a-1) a conjugated
diene rubber latex having a weight average particle diameter of 500
.ANG. to 2,000 .ANG. with (b-1) a methacrylic acid alkyl ester
compound or an acrylic acid alkyl ester compound, (c-1) an aromatic
vinyl compound, and (d-1) a vinyl cyan compound; (A-2) a graft
copolymer formed by graft-copolymerizing (a-2) a conjugated diene
rubber latex having a weight average particle diameter of 2,500
.ANG. to 5,000 .ANG. with (b-2) a methacrylic acid alkyl ester
compound or an acrylic acid alkyl ester compound, (c-2) an aromatic
vinyl compound, and (d-2) a vinyl cyan compound; and (B) a
copolymer formed by bulk-polymerizing i) a methacrylic acid alkyl
ester compound or an acrylic acid alkyl ester compound, ii) an
aromatic vinyl compound, and iii) a vinyl cyan compound, wherein
the thermoplastic resin composition satisfies Mathematical Equation
1 below:
0.75.ltoreq.X.sub.a-1/X.sub.a-2.ltoreq.4 [Mathematical Equation
1]
[0032] wherein X.sub.a-1 refers to the weight of (a-1) the
conjugated diene rubber latex (based on solid content) and
X.sub.a-2 refers to the weight of (a-2) the conjugated diene rubber
latex (based on solid content), wherein a refractive index
difference between (A-1) the graft copolymer and (A-2) the graft
copolymer is 0.01 or less, and a refractive index difference
between (A-1) the graft copolymer or (A-2) the graft copolymer and
(B) the copolymer is 0.01 or less.
[0033] In accordance with yet another aspect of the present
invention, there is provided a molded article manufactured from the
thermoplastic resin composition.
[0034] The molded article may be, for example, a washing machine
cover, a cleaner dust collector, a toy, a game machine housing, a
home appliance transparent window, or an office equipment
transparent window.
Advantageous Effects
[0035] As apparent from the above description, the present
invention provides a thermoplastic resin composition having
superior property balance, such as processability, chemical
resistance, heat stability, and impact resistance, and excellent
transparency, a method of preparing the same, and the like.
BEST MODE
[0036] Hereinafter, the present disclosure is described in
detail.
[0037] The present inventors have made intensive studies on a
method of further improving transparency while maintaining impact
strength. As a result, the present inventors confirmed that, when a
graft copolymer formed by graft-copolymerizing a conjugated diene
rubber latex having a weight average particle diameter of 500 .ANG.
to 2,000 .ANG. with a methacrylic acid alkyl ester compound or an
acrylic acid alkyl ester compound, an aromatic vinyl compound, and
a vinyl cyan compound; and the graft copolymer formed by
graft-copolymerizing a conjugated diene rubber latex having a
weight average particle diameter of 2,500 .ANG. to 5,000 .ANG. with
a methacrylic acid alkyl ester compound or an acrylic acid alkyl
ester compound, an aromatic vinyl compound, and a vinyl cyan
compound are applied to a copolymer formed by bulk-polymerizing a
methacrylic acid alkyl ester compound or an acrylic acid alkyl
ester compound, an aromatic vinyl compound, and a vinyl cyan
compound are applied to have a specific refractive index difference
in a specific weight ratio, a thermoplastic resin composition
having superior impact resistance and excellent transparency, i.e.,
a haze of 1.3 or less, is produced, thus completing the present
invention.
[0038] The thermoplastic resin composition according to the present
disclosure is characterized by including (A-1) a graft copolymer
formed by graft-copolymerizing (a-1) a conjugated diene rubber
latex having a weight average particle diameter of 500 .ANG. to
2,000 .ANG. with (b-1) a methacrylic acid alkyl ester compound or
an acrylic acid alkyl ester compound, (c-1) an aromatic vinyl
compound, and (d-1) a vinyl cyan compound; (A-2) a graft copolymer
formed by graft-copolymerizing (a-2) a conjugated diene rubber
latex having a weight average particle diameter of 2,500 .ANG. to
5,000 .ANG. with (b-2) a methacrylic acid alkyl ester compound or
an acrylic acid alkyl ester compound, (c-2) an aromatic vinyl
compound, and (d-2) a vinyl cyan compound; and (B) a copolymer
formed by polymerizing i) a methacrylic acid alkyl ester compound
or an acrylic acid alkyl ester compound, ii) an aromatic vinyl
compound, and iii) a vinyl cyan compound, wherein the thermoplastic
resin composition satisfies Mathematical Equation 1 below:
0.75.ltoreq.X.sub.a-1/X.sub.a-2.ltoreq.4 [Mathematical Equation
1]
[0039] wherein X.sub.a-1 refers to the weight of (a-1) the
conjugated diene rubber latex (based on solid content) and
X.sub.a-2 refers to the weight of (a-2) the conjugated diene rubber
latex (based on solid content), wherein a refractive index
difference between (A-1) the graft copolymer and (A-2) the graft
copolymer is 0.01 or less, and a refractive index difference
between (A-1) the graft copolymer or (A-2) the graft copolymer and
(B) the copolymer is 0.01 or less.
[0040] In the present disclosure, the content of the rubber latex
is based on solid content of the rubber latex.
[0041] The thermoplastic resin composition may include, for
example, 10 to 60% by weight of (A-1) the graft copolymer, 10 to
50% by weight of (A-2) the graft copolymer, and 30 to 80% by weight
of (B) the copolymer, wherein (A-1)+(A-2)+(B)=100% by weight.
Within this range, superior impact strength and transparency are
provided.
[0042] In another embodiment, the thermoplastic resin composition
may include 20 to 50% by weight of (A-1) the graft copolymer, 10 to
30% by weight of (A-2) the graft copolymer, and 40 to 70% by weight
of (B) the copolymer. Within this range, superior impact strength
and transparency are provided.
[0043] In another embodiment, the thermoplastic resin composition
may include 25 to 45% by weight of (A-1) the graft copolymer, 10 to
25% by weight of (A-2) the graft copolymer, and 45 to 55% by weight
of (B) the copolymer. Within this range, superior impact strength
and transparency are provided.
[0044] When X.sub.a-1/X.sub.a-2 is less than 0.75, transparency is
decreased. On the other hand, when X.sub.a-1/X.sub.a-2 is greater
than 4, impact strength is decreased, and thus, the purpose of the
present disclosure is not satisfied.
[0045] In another embodiment, X.sub.a-1/X.sub.a-2 may be 1 to 3,
1.5 to 3, or 1.5 to 2.7. Within this range, superior transparency,
impact strength, and the like are provided.
[0046] The thermoplastic resin composition may include, for
example, 5 to 30% by weight of (a-1) the conjugated diene rubber
latex. When the content of (a-1) the conjugated diene rubber latex
is less than 5% by weight, impact strength is decreased, and thus,
the purpose of the present disclosure is not satisfied. On the
other hand, when the content of (a-1) the conjugated diene rubber
latex is greater than 30% by weight, transparency is decreased and
flow marks are formed on a surface, whereby transparency is
decreased.
[0047] In another embodiment, the thermoplastic resin composition
may include 10 to 25% by weight or 13 to 22% by weight of (a-1) the
conjugated diene rubber latex. Within this range, superior impact
strength and transparency are provided.
[0048] (a-1) The conjugated diene rubber latex may have, for
example, a weight average particle diameter of 1,000 .ANG. to 1,500
.ANG., or 1,100 .ANG. to 1,300 .ANG.. Within this range, superior
impact strength and transparency are provided.
[0049] The thermoplastic resin composition may include, for
example, 5 to 20% by weight of (a-2) the conjugated diene rubber
latex. When the content of (a-2) the conjugated diene rubber latex
is less than 5% by weight, impact strength is decreased, and thus,
the purpose of the present disclosure is not satisfied. When the
content of (a-2) the conjugated diene rubber latex is greater than
20% by weight, transparency is decreased, and thus, it is difficult
to accomplish a transparency (i.e., a haze of 1.3 or less) required
in the present disclosure.
[0050] In another embodiment, the thermoplastic resin composition
may include 5 to 15% by weight or 6 to 12% by weight of (a-2) the
conjugated diene rubber latex. Within this range, superior impact
strength and transparency are provided.
[0051] (a-2) The conjugated diene rubber latex may have, for
example, a weight average particle diameter of 2,500 .ANG. to 4,000
.ANG., or 2,800 .ANG. to 3,500 .ANG.. Within this range, superior
impact strength and transparency are provided.
[0052] The conjugated diene rubber is a conjugated diene compound
polymer having a structure wherein a double bond and a single bond
are alternately arranged.
[0053] The conjugated diene compound may be, for example, one or
more selected from the group consisting of butadiene, isoprene,
chloroprene, and piperylene.
[0054] The conjugated diene rubber may be, for example, one or more
selected from the group consisting of butadiene polymer,
butadiene-styrene copolymer (SBR), and butadiene-acrylonitrile
copolymer (NBR) and polymers derived therefrom. In particular, a
butadiene copolymer or a butadiene-styrene copolymer is preferred.
In this case, impact strength satisfying the purpose of the present
disclosure and superior transparency are provided.
[0055] The derived polymer refers to a polymer polymerized by an
additionally added denaturant, a polymer modified by a modifier, a
polymer, an unsaturated group of which is hydrogenated, or a
polymer, some groups of which are substituted with other
groups.
[0056] The thermoplastic resin composition may include, for
example, a methacrylic acid alkyl ester compound and acrylic acid
alkyl ester compound in a total amount of 20 to 70% by weight, 40
to 60% by weight, or 50 to 60% by weight. Within this range, the
thermoplastic resin composition has a refractive index matching
that of the conjugated diene rubber latex, whereby superior
transparency is provided.
[0057] The thermoplastic resin composition may include, for
example, 10 to 30% by weight, 15 to 25% by weight, or 15 to 20% by
weight of an aromatic vinyl compound. Within this range, the
thermoplastic resin composition has a refractive index matching
that of the conjugated diene rubber latex, whereby superior
transparency is provided.
[0058] The thermoplastic resin composition may include, for
example, 0 to 10% by weight, 1 to 8% by weight, or 3 to 6% by
weight of a vinyl cyan compound. Within this range, superior color
characteristics are provided (not yellowish), thereby satisfying
the purpose of the present disclosure.
[0059] (A-1) The graft copolymer may be a copolymer formed by, for
example, polymerizing 20 to 70% by weight (based on solid content)
of (a-1) the conjugated diene rubber latex with 20 to 60% by weight
of (b) a methacrylic acid alkyl ester compound or acrylic acid
alkyl ester compound, 7 to 30% by weight of (c) an aromatic vinyl
compound, and 0 to 10% by weight of (d) a vinyl cyan compound.
[0060] When the content of (a-1) the conjugated diene rubber latex
in (A-1) the graft copolymer is less than 20% by weight, impact
strength is decreased. On the other hand, when the content of (a-1)
the conjugated diene rubber latex in (A-1) the graft copolymer is
greater than 70% by weight, complete grafting does not occur during
polymerization, whereby mechanical properties are very poor and
transparency is decreased.
[0061] When the content of the vinyl cyan compound in (A-1) the
graft copolymer is greater than 10 parts by weight, the color of a
resin turns yellow, whereby consumers' desire for natural color is
not satisfied. In addition, a large amount of a solid (coagulum) is
generated during graft-polymerizing, whereby it is difficult to
produce a resin.
[0062] In another embodiment, (A-1) the graft copolymer may be a
copolymer formed by polymerizing (a-1) 40 to 60% by weight (based
on solid content) of the conjugated diene rubber latex with (b) 25
to 45% by weight of a methacrylic acid alkyl ester compound or
acrylic acid alkyl ester compound, (c) 10 to 20% by weight of an
aromatic vinyl compound, and (d) 1 to 5% by weight of a vinyl cyan
compound. Within this range, superior impact strength and
transparency are provided.
[0063] (A-2) The graft copolymer may be a copolymer formed by, for
example, polymerizing 20 to 70% by weight (based on solid content)
of (a-2) the conjugated diene rubber latex with 20 to 60% by weight
of (b) a methacrylic acid alkyl ester compound or acrylic acid
alkyl ester compound, 7 to 30% by weight of (c) an aromatic vinyl
compound, and 0 to 10% by weight of (d) a vinyl cyan compound.
[0064] When the content of (a-2) the conjugated diene rubber latex
in (A-2) the graft copolymer is less than 20 parts by weight,
impact strength is decreased. On the other hand, when the content
of (a-2) the conjugated diene rubber latex in (A-2) the graft
copolymer is greater than 70 parts by weight, complete grafting
does not occur during polymerization, whereby mechanical properties
are greatly deteriorated and transparency is decreased.
[0065] When the content of the vinyl cyan compound in (A-2) the
graft copolymer is greater than 10 parts by weight, the color of a
resin turns yellow, whereby consumers' desire for natural color is
not satisfied and a large amount of solid (coagulum) is generated
during grafting polymerization. Accordingly, it is difficult to
produce a resin.
[0066] (A-2) The graft copolymer may be, for example, a polymer
formed by polymerizing (a-2) 40 to 60% by weight (based on solid
content) of the conjugated diene rubber latex with (b) 25 to 45% by
weight of a methacrylic acid alkyl ester compound or acrylic acid
alkyl ester compound, (c) 10 to 20% by weight of an aromatic vinyl
compound, and (d) 1 to 5% by weight of a vinyl cyan compound.
Within this range, superior impact strength and transparency are
provided.
[0067] The transparency of each of (A-1) the graft copolymer and
(A-2) the graft copolymer of the present disclosure is determined
depending upon the refractive indexes of a rubber and grafted
polymer. Here, the refractive index of the grafted polymer is
adjusted depending upon a mixing ratio of monomers. To have
transparency, the refractive index of the conjugated diene rubber
latex should match refractive indexes of other ingredients.
Accordingly, a mixing ratio of monomers is very important. That is,
to have transparency, the refractive index of the conjugated diene
rubber, which is used as a seed for grafting, should be similar to
the refractive index of a total of gradients grafted thereto. A
refractive index difference between the refractive index of the
conjugated diene rubber latex and a total of grafted compounds is
preferably 0.01 or less. More preferably, the refractive index of
the conjugated diene rubber is the same as that of a total of
ingredients grafted thereto.
[0068] The refractive indexes of polymers of the monomers used in
the present disclosure are follows: butadiene: about 1.518, methyl
methacrylate: about 1.49, styrene: about 1.59, acrylonitrile: about
1.52, acrylic acid: about 1.527, and polyethyleneglycol
monomethacrylate: about 1.49 to 1.52.
[0069] In addition, the refractive index of a mixture of compounds
graft-polymerized to the conjugated diene rubber of the grafted
copolymer, i.e., a copolymer, may be calculated according to the
following equation:
RI=.SIGMA.Wti*RIi
[0070] Wti=Weight Fraction of Each Ingredient in Copolymer (%)
[0071] RIi=Refractive Index of Polymer of Each Ingredient of
Copolymer
[0072] The refractive indexes of (a-1) the conjugated diene rubber
latex and (a-2) the conjugated diene rubber latex are related to
the transparency of product. A refractive index difference between
(a-1) the conjugated diene rubber latex and (a-2) the conjugated
diene rubber latex is preferably 0.01 or less. More preferably, the
refractive index of (a-1) the conjugated diene rubber latex matches
that of (a-2) the refractive index.
[0073] (A-1) The grafted copolymer and (A-2) the grafted copolymer
are respectively prepared by emulsion polymerization. The
ingredients (monomers) for grafting may be added batchwise or a
portion or the entirety thereof may be continuously added, in the
presence of the conjugated diene rubber latex.
[0074] The continuous addition may be carried out, for example, by
a stream or dropwise for a determined time.
[0075] The emulsifier used in the emulsion polymerization may be,
for example, an alkyl aryl sulfonate, an alkali metal alkyl
sulfate, a sulfonated alkyl ester salt, an alkyl (alkenyl)
carboxylate, or an alkyl (alkenyl) succinate, or the like. These
compounds may be used alone or as a mixture of two or more
thereof.
[0076] The graft copolymer in an emulsified state after the
emulsion polymerization may be prepared, for example, into a powder
by coagulating the emulsified graft copolymer into a coagulant and
then dehydrating and drying the same.
[0077] (B) The copolymer may be a copolymer formed by, for example,
polymerizing 30 to 75% by weight of a methacrylic acid alkyl ester
compound or acrylic acid alkyl ester compound, 15 to 40% by weight
of an aromatic vinyl compound, and 0 to 20% by weight of a vinyl
cyan compound. When the content of the vinyl cyan compound is
greater than 20% by weight, color turns yellow.
[0078] In another embodiment, (B) the copolymer may be a copolymer
formed by polymerizing 60 to 75% by weight of a methacrylic acid
alkyl ester compound or an acrylic acid alkyl ester compound, 20 to
30% by weight of an aromatic vinyl compound, and 1 to 10% by weight
of a vinyl cyan compound. Within this range, superior impact
strength, color characteristics and transparency are provided.
[0079] A method of preparing (B) the copolymer is not specifically
limited, but suspension polymerization or bulk polymerization is
suitable. In particular, continuous bulk polymerization is the most
preferable method in terms of production cost.
[0080] A refractive index difference between (A-1) the graft
copolymer or (A-2) the graft copolymer and (B) the copolymer may
be, for example, 0.01 or less. Within this range, superior
transparency is provided, and thus, the purpose of the present
disclosure is satisfied.
[0081] The aromatic vinyl compound of the present disclosure may
be, for example, one or more selected from the group consisting of
styrene, .alpha.-methylstyrene, o-ethylstyrene, p-methylstyrene,
and vinyltoluene. Preferably, the aromatic vinyl compound is
styrene.
[0082] For example, the vinyl cyan compound of the present
disclosure is preferably one or more selected from the group
consisting of acrylonitrile, methacrylonitrile and
ethacrylonitrile.
[0083] The present disclosure of a methacrylic acid alkyl ester
compound or an acrylic acid alkyl ester compound may be, for
example, one or more selected from the group consisting of
(meth)acrylic acid methyl ester, (meth)acrylic acid ethyl ester,
(meth)acrylic acid propyl ester, (meth)acrylic acid 2-ethylhexyl
ester, (meth)acrylic acid decyl ester and (meth)acrylic acid lauryl
ester. Thereamong, methyl methacrylate, as (meth)acrylic acid
methyl ester, is most preferred.
[0084] The thermoplastic resin composition may have, for example, a
haze of 1.3 or less, or 1.2 or less and an impact strength of 10
kgcm/cm or more, or 11 kgcm/cm or more.
[0085] The thermoplastic resin composition may further include, for
example, one or more selected from the group consisting of a
thermal stabilizer, a UV stabilizer, a lubricant, and an
antioxidant in a range in which the properties thereof are not
affected.
[0086] The present disclosure provides a method of preparing a
thermoplastic resin composition, the method including a step of
melt-kneading (A-1) a graft copolymer formed by
graft-copolymerizing (a-1) a conjugated diene rubber latex having a
weight average particle diameter of 500 .ANG. to 2,000 .ANG. with
(b-1) a methacrylic acid alkyl ester compound or an acrylic acid
alkyl ester compound, (c-1) an aromatic vinyl compound, and (d-1) a
vinyl cyan compound; (A-2) a graft copolymer formed by
graft-copolymerizing (a-2) a conjugated diene rubber latex having a
weight average particle diameter of 2,500 .ANG. to 5,000 .ANG. with
(b-2) a methacrylic acid alkyl ester compound or an acrylic acid
alkyl ester compound, (c-2) an aromatic vinyl compound, and (d-2) a
vinyl cyan compound; and (B) a copolymer formed by
bulk-polymerizing i) a methacrylic acid alkyl ester compound or an
acrylic acid alkyl ester compound, ii) an aromatic vinyl compound,
and iii) a vinyl cyan compound, wherein the thermoplastic resin
composition satisfies Mathematical Equation 1 below:
0.75.ltoreq.X.sub.a-1/X.sub.a-2.ltoreq.4 [Mathematical Equation
1]
[0087] wherein X.sub.a-1 refers to the weight of (a-1) the
conjugated diene rubber latex (based on solid content) and
X.sub.a-2 refers to the weight of (a-2) the conjugated diene rubber
latex (based on solid content), wherein a refractive index
difference between (A-1) the graft copolymer and (A-2) the graft
copolymer is 0.01 or less, and a refractive index difference
between (A-1) the graft copolymer or (A-2) the graft copolymer and
(B) the copolymer is 0.01 or less.
[0088] The method of preparing the thermoplastic resin composition
may include, for example, I) a step of mixing (a-1) the conjugated
diene rubber latex having a weight average particle diameter of 500
.ANG. to 2,000 .ANG. with (b-1) the methacrylic acid alkyl ester
compound or the acrylic acid alkyl ester compound, (c-1) the
aromatic vinyl compound, and (d-1) the vinyl cyan compound and then
forming a grafted layer through copolymerization to prepare the
graft copolymer (A-1); II) a step of mixing (a-2) the conjugated
diene rubber latex having a weight average particle diameter of
2,500 .ANG. to 5,000 .ANG. with (b-2) the methacrylic acid alkyl
ester compound or the acrylic acid alkyl ester compound, (c-2) the
aromatic vinyl compound, and (d-2) the vinyl cyan compound and then
forming a grafted layer through copolymerization to prepare the
graft copolymer (A-2); III) a step of bulk polymerizing i) the
methacrylic acid alkyl ester compound or the acrylic acid alkyl
ester compound, ii) the aromatic vinyl compound, and iii) the vinyl
cyan compound to prepare the copolymer (B); and a step of mixing
and kneading IV) (A-1) the graft copolymer, (A-2) the graft
copolymer, and (B) the copolymer.
[0089] The thermoplastic resin composition may be kneaded, for
example, by means of a single screw extruder, a twin screw
extruder, a banbury mixer, or the like. Subsequently, the kneaded
thermoplastic resin composition is extruded and is uniformly
dispersed, followed by being soaked in a water bath and being cut.
As a result, a pellet-type transparent resin may be prepared.
[0090] In addition, the present disclosure provides molded article
manufacture from the thermoplastic resin composition.
[0091] The molded article may be, for example, a washing machine
cover, a cleaner dust collector, a toy, a game machine housing, a
home appliance transparent window, or an office equipment
transparent window.
[0092] Now, the present invention will be described in more detail
with reference to the following preferred examples. However, these
examples are provided for illustrative purposes only. Those skilled
in the art will appreciate that various modifications, additions
and substitutions are possible, without departing from the scope
and spirit of the invention. Therefore, it is obvious that the
modifications, additions and substitutions are within the scope of
the present invention.
Example
Preparation Example I-1-1: Method of Preparing Graft Copolymer
(A-1-1)
[0093] To 50 parts by weight (based on solid content) of a
polybutadiene rubber latex, which had a gel content of 90% and an
average particle diameter of 1200 .ANG., prepared by emulsion
polymerization, 100 parts by weight of an exchanged water, 1.0
parts by weight of a sodium oleate emulsifier, 35 parts by weight
of methyl methacrylate, 12 parts by weight of styrene, 3 parts by
weight of acrylonitrile, 0.5 parts by weight of tertiary dodecyl
mercaptan, 0.05 parts by weight of ehylenediamine tetraacetic acid,
0.1 parts by weight of sodium formaldehyde sulfoxylate, 0.001 parts
by weight of ferrous sulfide, 0.2 parts by weight of tertiary butyl
hydroperoxide were continuously added at 5.degree. C. over five
hours such that polymerization occurred. Subsequently, aging was
carried out at 80.degree. C. for one hour and then reaction was
terminated. Subsequently, an obtained latex was coagulated using 2
parts by weight of magnesium sulfate, as a coagulant, followed by
dehydration and drying. As a result, a powder-type graft copolymer
was obtained. The refractive index of the obtained graft copolymer
was 1.516.
Preparation Example I-1-2: Method of Preparing Grafted Copolymer
(A-1-2)
[0094] A graft copolymer was obtained in the same manner as in
Preparation Example I-1-1, except that 25 parts by weight (based on
solid content) of a polybutadiene rubber latex having a gel content
of 90% and an average particle diameter of 1200 .ANG. and 25 parts
by weight (based on solid content) of a polybutadiene rubber latex
having a gel content of 70% and an average particle diameter of
3000 .ANG. were used instead of the rubber latex used in
Preparation Example I-1-1. The refractive index of the obtained
graft copolymer was 1.516.
Preparation Example I-1-3: Method of Preparing Grafted Copolymer
(A-1-3)
[0095] A graft copolymer was obtained in the same manner as in
Preparation Example I-1-1, except that 60 parts by weight (based on
solid content) of a polybutadiene rubber latex having a gel content
of 90% and an average particle diameter of 1200 .ANG., 28 parts by
weight of methyl methacrylate, 10 parts by weight of styrene, 2
parts by weight of acrylonitrile, and 0.4 parts by weight of
tertiary dodecyl mercaptan were used. The refractive index of the
obtained graft copolymer was 1.516.
Preparation Example I-2-1: Method of Preparing Grafted Copolymer
(A-2-1)
[0096] A graft copolymer was obtained in the same manner as in
Preparation Example I-1-1, except that 50 parts by weight of
polybutadiene rubber latex having a gel content of 70% and an
average particle diameter of 3000 .ANG. were used instead of the
rubber latex used in Preparation Example I-1-1. The refractive
index of the obtained graft copolymer was 1.516.
Preparation Example I-2-2: Method of Preparing Grafted Copolymer
(A-2-2)
[0097] A graft copolymer was obtained in the same manner as in
Preparation Example I-2-1, except that methyl methacrylate, which
was used in Preparation Example I-2-1, was used in an amount of
29.8 parts by weight instead of 35 parts by weight and styrene,
which was used in Preparation Example I-2-1, was used in an amount
of 19.2 parts by weight instead of 12 parts by weight. The
refractive index of the obtained graft copolymer was 1.53.
Preparation Example II-1: Method of Preparing MSAN Resin (B-1)
[0098] 70.4 parts by weight of methyl methacrylate, 24.6 parts by
weight of styrene, and 5 parts by weight of acrylonitrile were
mixed with 30 parts by weight of toluene, as a solvent, and 0.15
parts by weight of di-t-dodecyl mercaptan, as a molecular weight
regulator. A resultant mixture was continuously added to a reactor
over three hours on average while maintaining a reaction
temperature at 148.degree. C. Subsequently, a resultant polymerized
solution was discharged from the reactor. The discharged
polymerized solution was heated in a preparatory heating bath, and
unreacted monomers were volatilized in a volatilization vessel.
Subsequently, while maintaining the temperature of a polymer at
210.degree. C., a copolymer (MSAN resin) was processed into a
pellet form by means of a polymer transfer pump extrusion machine.
The refractive index of the prepared MSAN resin was 1.516.
Preparation Example 11-2: Method of Preparing MMSAN Resin (B-2)
[0099] A graft copolymer was obtained in the same manner as in
Preparation Example II-1, except that 40 parts by weight of methyl
methacrylate and 50 parts by weight of styrene were used instead of
70.4 parts by weight of methyl methacrylate and 24.6 parts by
weight of styrene used in Preparation Example II-1. The refractive
index of the prepared MSAN resin was 1.542.
Examples 1 and 2 and Comparative Examples 1 to 4
[0100] Each of the grafted copolymers and the MSAN resins prepared
according to Preparation Examples I-1-1 to 11-2 was mixed as
summarized in Table 1 below, and 0.3 parts by weight of a lubricant
and 0.2 parts by weight of an antioxidant were added thereto. A
resultant mixture was prepared into a pellet-type thermoplastic
resin composition by means of a biaxial extrusion kneader in a
220.degree. C. cylinder. A prepared pellet was injection-molded,
whereby a specimen was prepared.
TABLE-US-00001 TABLE 1 Graft copolymer (A) MSAN (B) Classification
A-1-1 A-1-2 A-1-3 A-2-1 A-2-2 B-1 B-2 Example 1 30 20 50 Example 2
40 15 55 Example 3 27 13 60 Comparative 50 50 Example 1 Comparative
30 20 50 Example 2 Comparative 30 20 50 Example 3 Comparative 10 40
50 Example 4 Comparative 45 5 50 Example 5 Comparative 20 30
Example 6 Comparative 33 7 Example 7
Test Example
[0101] The properties of each of the thermoplastic resin
composition specimens prepared according to each of Examples 1 to 3
and Comparative Examples 1 to 7 were measured according to the
following methods. Results are summarized in Table 2 below. [0102]
Weight average particle diameter: The weight average particle size
of a rubber latex used in polymerization was measured by means of
Nicomp 380. [0103] Refractive index: To investigate the refractive
index of each copolymer, the copolymer was thinly spread to a
thickness of about 0.2 mm. Measurement was performed by means of an
Abbe refractometer at 25.degree. C. [0104] Transparency (haze
value): Measured according to ASTM1003. [0105] Impact strength
(Notched Izod Impact Strength): Notched Izod impact strength was
measured according to ASTM245 D256.
TABLE-US-00002 [0105] TABLE 2 Transparency Impact strength
Classification (haze) (kg cm/cm) Example 1 1.2 15.6 Example 2 1.0
11.5 Example 3 0.9 10.7 Comparative Example 1 2.6 18.7 Comparative
Example 2 42.9 16.3 Comparative Example 3 48.2 16.1 Comparative
Example 4 2.7 21.7 Comparative Example 5 0.9 5.2 Comparative
Example 6 1.6 22.3 Comparative Example 7 0.9 7.8
[0106] As shown in Table 1, it can be confirmed that all of the
thermoplastic resin compositions (Examples 1 to 3) of the present
disclosure have superior transparency and impact strength, and
thus, satisfy the purpose of the present disclosure.
[0107] However, in the case of Comparative Example 1, the rubber
latex ratio and the refractive index adjustment correspond to the
intention of the present disclosure, but desired transparency was
not obtained because the small-diameter and large-diameter rubbers
were simultaneously added during preparation of the graft copolymer
such that graft-polymerization occurred.
[0108] In addition, in the cases of Comparative Examples 2 and 3,
the refractive index of the rubber is different from that of the
graft copolymer, or the refractive index of the graft copolymer (A)
is different from that of the copolymerization resin (B), whereby a
haze rapidly increases and thus transparency is decreased.
[0109] Further, in the cases of Comparative Examples 4 and 6, the
X.sub.a-1/X.sub.a-2 value is less than 0.75 and thus impact
strength is very high. However, desired transparency is not
secured.
[0110] Finally, in the cases of Comparative Examples 5 and 7, the
X.sub.a-1/X.sub.a-2 value is greater than 4 and thus excellent
transparency is exhibited. However, desired impact strength is not
secured.
* * * * *