KR20150037395A - Transparent Thermoplastic Resin Composition with Excellent Chemical Resistance - Google Patents

Abstract

The present invention relates to a thermoplastic resin composition whose transparency and chemical resistance can be improved dramatically by containing: (A) a basic resin consisting of (a1) graft copolymers obtained by grafting methacrylic acid alkyl-ester compounds, aromatic vinyl compounds, and vinyl cyanide compounds to conjugated diene rubber latex, (a2) aromatic vinyl-cyanide vinyl copolymers, and (a3) polyalkyl(meth)acrylate; and (B) acryl copolymers.

Description

BACKGROUND ART [0002] Transparent Thermoplastic Resin Composition with Excellent Chemical Resistance [

TECHNICAL FIELD The present invention relates to a thermoplastic resin composition, and more particularly, to a thermoplastic resin composition including a base resin containing a styrene resin and an acrylic copolymer, and having excellent transparency, impact strength and chemical resistance.

Acrylonitrile-butadiene-styrene (ABS) resin based on styrene is excellent in impact resistance and processability, has excellent mechanical strength, heat distortion temperature and gloss, and particularly excellent in transparency. Electronic products or housings. However, products using these resins have poor chemical resistance and require careful contact with organic solvents, specific detergents, strong alkalis, specific fatty acids, oils or greases.

U.S. Patent No. 4,482,695 (Patent Document 1) discloses a method of increasing basic chemical resistance by blocking direct contact of a chemical with a polyamide resin imparted with gas barrier properties, And is applied to a styrene resin to impart chemical resistance. However, the use of a styrenic resin, for example, a polyamide compound in an ABS resin can improve the chemical resistance, but the transparency is deteriorated due to the difference in refractive index between the polyamide component and the styrenic resin .

Therefore, there is a demand for a technique capable of improving the chemical resistance of the styrenic thermoplastic resin composition, without deteriorating the transparency, in terms of processability, impact resistance, rigidity and gloss.

U.S. Patent No. 4,482,695 (November 13, 1984)

It is an object of the present invention to provide a thermoplastic resin composition capable of improving chemical resistance while exhibiting excellent transparency, impact resistance and rigidity.

Another object of the present invention is to provide a molded article excellent in transparency and chemical resistance produced from the thermoplastic resin composition.

(A) a graft copolymer obtained by grafting a (meth) acrylic acid alkyl ester compound, an aromatic vinyl compound and a vinyl cyanide compound onto a conjugated diene rubber latex, (a2) ) A thermoplastic resin composition comprising an aromatic vinyl-cyanide vinyl-based copolymer and (a3) a basic resin composed of a polyalkyl (meth) acrylate and (B) an acrylic copolymer.

In the thermoplastic resin composition according to one embodiment of the present invention, the base resin (A) preferably contains 8 to 50 wt% of the graft copolymer (a1), 10 to 40 wt% of the aromatic vinyl-cyanide vinyl copolymer (a2) And 30 to 70% by weight of polyalkyl (meth) acrylate (a3).

In the thermoplastic resin composition according to one embodiment of the present invention, the acrylic copolymer (B) may be contained in an amount of 0.1 to 10 parts by weight based on 100 parts by weight of the base resin (A).

In the thermoplastic resin composition according to the embodiment of the present invention, the weight ratio of the aromatic vinyl-cyanide vinyl copolymer (a2) and the polyalkyl (meth) acrylate (a3) is from 1: 5: 5.

In the thermoplastic resin composition according to an embodiment of the present invention, the acrylic copolymer may include cyclohexyl methacrylate. In the thermoplastic resin composition according to an embodiment of the present invention, the content of the repeating unit of cyclohexyl methacrylate may be 50 to 90% by weight in the acrylic copolymer. The present invention can provide a molded article produced from the thermoplastic resin composition.

INDUSTRIAL APPLICABILITY The thermoplastic resin composition according to the present invention exhibits excellent transparency without deteriorating processability, impact resistance and mechanical properties, and also has high fluidity characteristics and is excellent in chemical resistance against a specific detergent, organic solvent, strong alkali, specific fatty acid, There is an excellent advantage.

Hereinafter, the thermoplastic resin composition having excellent transparency and chemical resistance of the present invention will be described in detail. The following embodiments are provided by way of example so that those skilled in the art can fully understand the spirit of the present invention. It will be apparent to those skilled in the art that, unless otherwise defined, technical terms and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs, And a description of the known function and configuration will be omitted.

Unless otherwise specified in the present specification, "?" Denotes a group in which a hydrogen atom is replaced by a halogen atom, a hydroxy group, a nitro group, a cyano group, an amino group, an azido group, an amidino group, a hydrazino group, a hydrazino group, a carbonyl group, A C1 to C20 alkyl group, a C2 to C20 alkenyl group, a C2 to C20 alkynyl group, a C1 to C20 alkoxy group, a C6 to C30 alkoxy group, a C1 to C20 alkoxy group, An aryl group, a C6 to C30 aryloxy group, a C3 to C30 cycloalkyl group, a C3 to C30 cycloalkenyl group, a C3 to C30 cycloalkynyl group, or a combination thereof.

&Quot; (meth) acrylate "means" acrylate "and" methacrylate ", unless otherwise specified in the present specification, Acrylate ester " and "methacrylic acid alkyl ester ", and the term" (meth) acrylic acid ester "may mean" acrylic acid ester "and" methacrylic acid ester ".

The inventors of the present invention have studied to develop a thermoplastic resin composition capable of drastically improving chemical resistance without deteriorating transparency. As a result, it has been found that (meth) acrylic acid alkyl ester compound, aromatic vinyl compound and vinyl (Meth) acrylate and a graft copolymer obtained by grafting a cyanide compound, an aromatic vinyl-cyanide vinyl copolymer and a polyalkyl (meth) acrylate, surprisingly exhibits a synergistic effect of transparency and chemical resistance And thus the present invention has been completed.

The thermoplastic resin composition of the present invention comprises (A) a graft copolymer (a1) obtained by grafting a (meth) acrylic acid alkyl ester compound, an aromatic vinyl compound and a vinyl cyanide compound onto a conjugated diene rubber latex, an aromatic vinyl-cyanide vinyl copolymer (a2) and a polyalkyl (meth) acrylate (a3) and (B) an acrylic copolymer.

(A) Base resin

(a1) graft copolymer

In the present invention, the graft copolymer may be prepared by grafting a (meth) acrylic acid alkyl ester compound, an aromatic vinyl compound and a vinyl cyanide compound to a conjugated diene rubber latex.

As the conjugated diene rubber latex, general butadiene rubber latex or styrene-butadiene copolymer latex can be used, but the present invention is not limited thereto. The conjugated diene rubber latex may have an average particle size of preferably 0.1 to 5.0 mu m. The conjugated diene rubber latex may be 5 to 70% by weight of the total weight of the graft copolymer.

The (meth) acrylic acid alkyl ester compound may be any one or two selected from the group consisting of methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, The above mixture may be used.

The aromatic vinyl compound may include but is not limited to one selected from styrene, C1 to C10 alkyl substituted styrene, halogen substituted styrene, vinyl toluene, vinyl naphthalene, and combinations thereof. The alkyl-substituted styrene may include, but is not limited to, one selected from? -Methylstyrene, o-ethylstyrene, m-ethylstyrene, p-ethylstyrene, and combinations thereof.

The vinyl cyanide compound may be acrylonitrile, methacrylonitrile or ethacrylonitrile, and it is preferable to use acrylonitrile.

The graft copolymer using the above component can be produced by any of the conventional methods such as emulsion polymerization, suspension polymerization, solution polymerization, and bulk polymerization. The polymerization initiator can be used in the presence of the above components Emulsion polymerization or bulk polymerization can be carried out.

In the present invention, the graft copolymer (a1) may be contained in an amount of 8 to 50% by weight based on the total weight of the base resin (A). If the content of the graft copolymer exceeds 50% by weight, the processing may be difficult.

(a2) an aromatic vinyl-cyanide vinyl copolymer

In the present invention, the aromatic vinyl-cyanide vinyl copolymer (a2) may be a copolymer of an aromatic vinyl compound and a vinyl cyanide compound.

The aromatic vinyl compound may be selected from the group consisting of styrene, C1-C10 alkyl-substituted styrene, halogen-substituted styrene, vinyltoluene, vinylnaphthalene, and combinations thereof. Specific examples of the alkyl-substituted styrene include? -Methylstyrene, p-methylstyrene, o-ethylstyrene, m-ethylstyrene, p-ethylstyrene, pt-butylstyrene and 2,4-dimethylstyrene.

As the vinyl cyanide compound, at least one selected from acrylonitrile, methacrylonitrile, ethacrylonitrile, and combinations thereof may be used.

Specific examples of the aromatic vinyl-cyanide vinyl copolymer (a2) include copolymers of styrene and acrylonitrile; copolymers of? -methylstyrene and acrylonitrile; Or copolymers of styrene,? -Methylstyrene and acrylonitrile, and preferably styrene-acrylonitrile copolymers.

In the present invention, the aromatic vinyl-cyanide vinyl copolymer (a2) may be contained in an amount of 10 to 40% by weight based on the total weight of the base resin (A). If the content of the aromatic vinyl-cyanide vinyl copolymer (a2) is out of the above range, it may be difficult to ensure transparency due to the difference in refractive index with polyalkyl (meth) acrylate.

(a3) polyalkyl (meth) acrylate

In the present invention, polyalkyl (meth) acrylate is resistant to hydrolysis while imparting impact resistance and gloss, and can improve miscibility and chemical resistance in combination with other components in the composition. The polyalkyl (meth) acrylate can be obtained by polymerizing a starting monomer containing an alkyl (meth) acrylate by a known polymerization method such as a suspension polymerization method, a bulk polymerization method and an emulsion polymerization method.

The alkyl (meth) acrylate which is a monomer of the polyalkyl (meth) acrylate resin (a3) has an alkyl group of C1 to C10 and includes, for example, methyl (meth) acrylate, ethyl (meth) (Meth) acrylate, glycidyl (meth) acrylate, and hydroxyethyl (meth) acrylate. The alkyl (meth) acrylate may be contained in an amount of 50% by weight or more, and preferably 80 to 99% by weight based on the total weight of the polyalkyl (meth) acrylate resin (a3).

The weight ratio (a2: a3) of the polyalkyl (meth) acrylate resin (a3) to the aromatic vinyl-cyanide vinyl copolymer (a2) is preferably 1: 9 to 5: 5. The impact resistance, mechanical properties and surface gloss characteristics of the molded article obtained within the above range are improved and intermolecular interaction with the above-mentioned graft copolymer (a1) and aromatic vinyl-cyanide vinyl copolymer (a2) And the transparency and the chemical resistance can be improved.

In the present invention, the polyalkyl (meth) acrylate resin (a3) is preferably contained in an amount of 30 to 70% by weight based on the total weight of the base resin (A). If the content of the polyalkyl (meth) acrylate resin (a3) is out of the above range, it is difficult to ensure transparency due to the difference in refractive index with the component (a2).

 (B) an acrylic copolymer

In the present invention, the acrylic copolymer includes at least one monomer selected from the group consisting of an alkyl (meth) acrylate and a mixture thereof, and at least one monomer selected from the group consisting of allyl glycidyl ether, glycidyl acrylate, glycidyl methacrylate, Or an unsaturated carboxylic acid selected from the group consisting of a glycidyl monomer and an unsaturated carboxylic acid.

The alkyl (meth) acrylate may have 1 to 10, preferably less than 4 carbon atoms in the alkyl group. Specific examples thereof include acrylic acid esters such as methyl acrylate, ethyl acrylate, butyl acrylate, methyl butyl acrylate, 4-methyl-2-pentyl acrylate, 2-ethylhexyl acrylate, isooctyl acrylate, cyclohexyl acrylate, Acrylates such as methyl methacrylate, methyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, isodecyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, 2-methylphenyl methacrylate, methoxyphenyl methacrylate , Ethoxy phenyl methacrylate, and naphthyl methacrylate.

The acrylic copolymer may preferably be cyclohexyl methacrylate as a repeating unit monomer. At this time, the content of cyclohexyl methacrylate may be 50 to 90% by weight, preferably 60 to 90% by weight.

In the present invention, when the acrylic copolymer is a repeating unit monomer and cyclohexyl methacrylate is contained in the content within the above range, it can be combined with other components to improve the fluidity without deteriorating the mechanical properties and exhibit a synergistic effect of transparency and chemical resistance Can be expressed.

Further, the acrylic copolymer may be prepared by radical polymerization of cyclohexyl methacrylate in the presence of a solvent and a polymerization initiator.

Examples of the solvent used in the preparation of the acrylic copolymer include methanol, tetrahydrofuran, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether acetate, methylcellosolve acetate, ethylcellosolve acetate, Ethers such as diethylene glycol monomethyl ether and diethylene glycol monoethyl ether, and combinations thereof.

Examples of the polymerization initiator include 2,2'-azobisisobutyronitrile, 2,2'-azobis (2,4-dimethylvaleronitrile), 2,2'-azobis (4-methoxy 2,4 -Dimethylvaleronitrile), and the like.

The acrylic copolymer may have a weight average molecular weight of preferably 2,000 to 10,000 g / mol, and more preferably 2.000 to 5,000 / mol.

In the present invention, the acrylic copolymer may be contained in an amount of 0.1 to 10 parts by weight based on 100 parts by weight of the base resin in order to exhibit a desired synergistic effect by combination with other components. If the amount is outside the range of 10 parts by weight, the heat resistance is remarkably reduced.

The thermoplastic resin composition of the present invention may contain additives such as a dye, a pigment, a flame retardant, a filler, a stabilizer, a lubricant, an antibacterial agent, a releasing agent, an antistatic agent and an antioxidant to further impart moldability and physical properties. These additives may be used alone or in combination of two or more, but are not necessarily limited thereto.

The present invention provides a molded article produced from the thermoplastic resin composition. These molded products are excellent in impact resistance, rigidity and transparency, and can be applied to a variety of materials such as electrical and electronic products and housings having excellent chemical resistance.

Hereinafter, the present invention will be described in more detail with reference to the following examples. However, the present invention is not limited to the following examples.

The specifications of each component used in the following examples and comparative examples are as follows.

(a1) Graft Copolymer:

Butadiene rubber latex was graft-polymerized with methyl methacrylate, acrylonitrile and styrene, and a rubber latex content of 55% by weight was used.

(a2) styrene-acrylonitrile copolymer:

SAN resin having an acrylonitrile content of 15% by weight, a styrene content of 85% by weight, and a weight average molecular weight of 120,000 was used.

(a3) Polymethyl methacrylate:

PMMA resin having a weight-average molecular weight of 110,000 g / mol consisting of methyl methacrylate was used.

(B) Acrylic copolymer:

A copolymer obtained by polymerizing 30% by weight of methyl methacrylate and 70% by weight of cyclohexyl methacrylate was used.

(Examples 1 to 3)

The thermoplastic resin compositions according to Examples 1 to 3 were prepared with the compositions shown in the following Table 1 and then subjected to extrusion processing to produce pelletized thermoplastic resins. At this time, a twin-screw extruder having an L / D of 29 and a diameter of 45 mm was used, and the barrel temperature was set at 230 ° C. The pellets were dried at 80 ° C. for 2 hours and then cooled to a cylinder temperature of 240 ° C. and a mold temperature of 60 ° C. using a 6 oz injection molding machine to obtain a test specimen and a test specimen of 9 cm × 5 cm × 0.2 cm .

(Comparative Example 1)

Except that 10 parts by weight of a polyamide resin (Sanyo, Pellestat-7530) was added to 100 parts by weight of the base resin instead of the acrylic copolymer.

(Comparative Example 2)

The procedure of Example 1 was repeated except that no acrylic copolymer was added.

(Comparative Example 3)

The procedure of Example 1 was repeated except that the content of the acrylic copolymer was changed to 0.01 part by weight.

(Comparative Example 4)

The procedure of Example 1 was repeated except that 15 parts by weight of the acrylic copolymer was used.

(Comparative Example 5)

The procedure of Example 1 was repeated except that the content of the styrene acrylonitrile compound and the polymethylmethacrylate resin in the base resin was changed to 60 wt% and 10 wt%, respectively.

(Property evaluation)

1) Haze value

ASTM D1003.

2) Chemical resistance

Tensile Strength Test Specimens were mounted on a 1.5% strain jig and wetted with NANOX detergent, 55% surfactant, and the changes of the specimens were measured as follows.

C: Crack occurrence time (min)

P: Break time (min)

Table 1.

As can be seen from the above Table 1, it can be seen that Examples 1 to 3 according to the present invention can remarkably increase the chemical resistance even though the transparency is remarkably high as compared with the Comparative Examples. On the other hand, in Comparative Example 1, 10 parts by weight of polyamide relative to 100 parts by weight of the base resin was used to increase the chemical resistance, but transparency dropped sharply. In Comparative Examples 2 and 3, transparency was improved, I could not see the effect. In Comparative Examples 4 and 5, it was confirmed that although the chemical resistance was improved, the transparency was lowered. .

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, Various modifications and variations are possible in light of the above teachings.

Accordingly, the spirit of the present invention should not be construed as being limited to the embodiments described, and all of the equivalents or equivalents of the claims, as well as the following claims, belong to the scope of the present invention .

Claims (7)

(A3) a graft copolymer obtained by grafting a (meth) acrylic acid alkyl ester compound, an aromatic vinyl compound, and a vinyl cyanide compound onto a conjugated diene rubber latex, (a2) an aromatic vinyl-cyanide vinyl copolymer, and (a3) A thermoplastic resin composition comprising a base resin composed of polyalkyl (meth) acrylate and (B) an acrylic copolymer.
The method according to claim 1,
The base resin (A) preferably contains 8 to 50% by weight of the graft copolymer (a1), 10 to 40% by weight of the aromatic vinyl-cyanide vinyl copolymer (a2) and 30 to 70% by weight of the polyalkyl (meth) acrylate By weight based on the total weight of the thermoplastic resin composition.
The method according to claim 1,
Wherein the acrylic copolymer (B) comprises 0.01 to 10 parts by weight based on 100 parts by weight of the base resin.
The method according to claim 1,
Wherein the base resin (A) has a weight mixing ratio of the aromatic vinyl-cyanide vinyl copolymer (a2) and the polyalkyl (meth) acrylate (a3) of 1: 9 to 5: 5.
The method according to claim 1,
Wherein the acrylic copolymer comprises cyclohexyl methacrylate.
The method according to claim 1,
Wherein the content of the cyclohexyl methacrylate monomer in the acrylic copolymer is 50 to 90% by weight.
A molded article produced from the composition of any one of claims 1 to 6.