KR20150067714A - Composition of styrene resin - Google Patents

Abstract

The present invention relates to a styrene-based resin composition and a styrene-based resin molded product. The styrene-based resin composition has excellent impact resistance, heat resistance, and chemical resistance (environmental stress resistance and crack resistance) and includes 20 wt% or smaller of a copolymer including N-phenyl maleimide or a copolymer including α-methyl styrene. According to an embodiment of the present invention, the styrene-based resin produced from the styrene-based resin composition has excellent impact resistance, heat resistance, and chemical resistance (environmental stress resistance and crack resistance). Therefore, the styrene-based resin composition and the styrene-based resin molded product can be widely applied to various industrial fields needing the same.

Description

[0001] Composition of styrene resin [0002]

The present invention relates to a styrene type resin composition comprising 20% by weight or less of a copolymer containing N-phenylmaleimide or a copolymer of? -Methylstyrene, which has excellent impact resistance, heat resistance and chemical resistance (environmental stress cracking resistance) And a molded article of a styrene-based resin produced from the resin.

Generally, styrene resins are excellent in moldability, rigidity and electrical characteristics, and are widely used in a variety of industrial fields including office automation equipment such as computers, printers, copying machines, household electrical appliances such as televisions and audios, electric and electronic parts, automobile parts, . Particularly, heat-resistant styrene resins which are resistant to external high temperatures by increasing the heat resistance are used for special applications such as housings for home appliances and automobile interior materials.

On the other hand, the resin used as a food container or a refrigerator interior material is required to have chemical resistance (environmental stress cracking property), but the styrene resin has a low chemical resistance (environmental stress cracking resistance) have. Accordingly, studies for developing a styrenic resin having excellent chemical resistance (environmental stress cracking resistance) while maintaining the characteristics of a conventional styrenic resin have been actively conducted.

However, styrene resins excellent in impact resistance, excellent in impact resistance and heat resistance have been developed through many studies, but styrene resins having satisfactory resistance to impact and heat resistance and satisfactory chemical resistance are insufficient.

Therefore, in order to further improve the usability of the styrenic resin, it is necessary to develop a styrenic resin having improved chemical resistance while maintaining the characteristics of the conventional styrenic resin, that is, a styrenic resin having excellent impact resistance, heat resistance and chemical resistance .

Under the above circumstances, the inventors of the present invention have been studying a styrenic resin having excellent impact resistance and heat resistance, and at the same time having excellent chemical resistance (environmental stress cracking resistance), and it has been found that a copolymer containing N-phenylmaleimide or? Styrene-based resin composition containing a styrene-containing copolymer in an amount of 20% by weight or less has excellent impact resistance and heat resistance and has high chemical resistance, thereby completing the present invention.

KR 2010-0090705 A

An object of the present invention is to provide a styrene-based resin containing 20% by weight or less of an N-phenylmaleimide-containing copolymer or an? -Methylstyrene-containing copolymer having excellent impact resistance, heat resistance and chemical resistance (environmental stress cracking resistance) To provide a composition.

Another object of the present invention is to provide a styrene-based resin molded article produced from the above styrene-based resin composition.

In order to solve the above problems, the present invention provides a thermoplastic resin composition comprising: a) 60 to 80% by weight of a styrenic copolymer having a weight average molecular weight (Mw) of 80,000 to 150,000; b) from 15% to 30% by weight of an acrylonitrile-butadiene-styrene (ABS) graft copolymer of core-shell structure; And c) 5 to 20% by weight of a heat-resistant copolymer having a weight average molecular weight (Mw) of less than 100,000 to less than 200,000.

The present invention also provides a molded article of a styrene type resin produced from the above styrene type resin composition.

The styrenic resin prepared from the styrene resin composition containing 5 to 20% by weight of the heat-resistant copolymer according to the present invention has excellent impact resistance and heat resistance, and has high chemical resistance (environmental stress cracking property) .

Therefore, the styrene resin composition and the styrene resin molded article according to the present invention can be widely applied to various industrial fields requiring them.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate exemplary embodiments of the invention and, together with the description of the invention, It should not be construed as limited.
1 is a TEM (transmission electron microscope) measurement result of an acrylonitrile-butadiene-styrene graft copolymer having a core-shell structure according to an embodiment of the present invention. (B) a bimodal acrylonitrile-butadiene-styrene graft copolymer having a core-shell structure. The term " bimodal acrylonitrile-butadiene-styrene graft copolymer "

Hereinafter, the present invention will be described in detail in order to facilitate understanding of the present invention.

The terms and words used in the present specification and claims should not be construed in an ordinary or dictionary sense and the inventor can properly define the concept of the term to describe its invention in the best possible way It should be construed as meaning and concept consistent with the technical idea of the present invention.

The present invention provides a styrenic resin composition comprising a heat-resistant copolymer and having chemical resistance while maintaining excellent impact resistance and heat resistance.

Generally, styrenic resins have excellent impact resistance and are used in various fields. Among them, heat-resistant styrenic resins, which can withstand high temperatures even outside, can be applied to special applications such as interior materials for automobiles and housings for home appliances . However, the above-mentioned styrene-based resin is excellent in impact resistance, impact resistance and heat resistance, but has a problem that chemical resistance is greatly lowered. Therefore, in order to further improve the usability of the styrene-based resin, it is necessary to develop a styrene-based resin having improved chemical resistance while maintaining the characteristics of the existing styrene-based resin.

Accordingly, the present invention relates to a thermoplastic resin composition comprising a styrenic copolymer having a core-shell structure of Unimodal acrylonitrile-butadiene-styrene (ABS) graft copolymer and a heat-resistant copolymer to improve chemical resistance And provides the improved styrene resin composition.

The styrene resin composition according to one embodiment of the present invention comprises: a) 60 to 80% by weight of a styrenic copolymer having a weight average molecular weight (Mw) of 80,000 to 150,000; b) from 15% to 30% by weight of an acrylonitrile-butadiene-styrene (ABS) graft copolymer of core-shell structure; And c) from 5 to 20% by weight of a heat-resistant copolymer having a weight average molecular weight (Mw) of less than 100,000 to less than 200,000.

Hereinafter, the present invention will be described in more detail.

a) a styrenic copolymer

The styrenic copolymer according to one embodiment of the present invention is a graft copolymer of an aromatic vinyl compound and a vinyl cyan compound, and may be a copolymer of? -Methylstyrene and an acrylonitrile copolymer (AMS-AN),? -Methylstyrene, Nitrile and styrene copolymers (AMS-AN-SM).

Specifically, when the styrenic copolymer is? -Methylstyrene and an acrylonitrile copolymer (AMS-AN), the copolymer (AMS-AN) contains 60% by weight to 80% by weight of? And 20% to 40% by weight of ronitryl. When the styrenic copolymer is? -Methylstyrene, acrylonitrile and styrene copolymer (AMS-AN-SM), the copolymer (AMS-AN-SM) contains 55 wt% to 75 wt% 15 to 35% by weight of acrylonitrile, and 1 to 15% by weight of styrene.

As described above, the styrenic copolymer may have a weight average molecular weight (Mw) of 80,000 to 150,000, and may be 100,000 to 130,000.

The styrenic copolymer may have a glass transition temperature of 122 캜 to 126 캜.

The styrenic copolymer according to the present invention may be contained in the styrenic resin composition in an amount of 60% by weight to 80% by weight, specifically 65% by weight to 75% by weight, as described above. If the styrenic copolymer is contained in an amount of less than 60% by weight, the flowability of the styrene-based resin composition is lowered and the moldability of the molded article may be reduced. The impact strength and heat resistance of a molded article produced from the styrene-based resin composition may deteriorate.

On the other hand, the styrenic copolymer is not particularly limited and may be used in the manufacture or use of a commercially available substance.

When the styrenic copolymer is prepared and used, it is not particularly limited and it can be produced by a commonly known production method in the art. For example, it can be produced by bulk polymerization of alpha -methylstyrene and acrylonitrile or alpha -methylstyrene, acrylonitrile and styrene, or by emulsion polymerization. Specifically, it can be produced by bulk polymerization.

The bulk polymerization is not particularly limited and can be carried out by a conventional method known in the art. For example, a polymer is prepared by mixing α-methylstyrene and acrylonitrile or a-methylstyrene, acrylonitrile, and styrene with a reaction medium and heating them at a temperature of 80 ° C. to 160 ° C., And removing the reaction medium.

The reaction medium may be a conventional organic solvent, for example, an aromatic compound such as ethylbenzene, benzene, toluene, and xylene, and methyl ethyl ketone, acetone, n-hexane, chloroform, cyclohexane, It is not.

In addition to the above-described materials, the bulk polymerization may further include additives such as polymerization initiators and molecular weight regulators.

The polymerization initiator is not particularly limited. Examples of the polymerization initiator include water-soluble persulfate-based polymerization initiators such as potassium persulfate, sodium persulfate or ammonium persulfate, hydrogen peroxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, A redox-based polymerization initiator having a peroxide such as an oxide, a pyramentane hydroperoxide or the like as a single component, or the like can be added singly or in combination.

The molecular weight regulator may be a conventional material such as mercaptans, but may be n-butyl mercaptan, n-octylmercaptan, n-dodecylmercaptan, t-dodecylmercaptan, May be mercaptans.

b) an acrylonitrile-butadiene-styrene (ABS) graft copolymer of core-shell structure

The acrylonitrile-butadiene-styrene (ABS) graft copolymer of the core-shell structure according to an embodiment of the present invention comprises a diene-based polymer core and a shell containing an aromatic vinyl compound and a vinyl cyanide May be grafted.

Specifically, the acrylonitrile-butadiene-styrene (ABS) graft copolymer of the core-shell structure comprises 50 to 80% by weight of a diene-based polymer core and an aromatic vinyl compound and a vinyl cyan compound on the core 20% to 50% by weight of the shell may be grafted. At this time, the aromatic vinyl compound and the vinyl cyan compound contained in the shell may have a weight ratio of 17: 3 to 11: 7.

The acrylonitrile-butadiene-styrene graft copolymer of the core-shell structure may have an average particle diameter of 300 nm to 400 nm, and may have a monomolecular characteristic. In this case, the term " unimodal characteristic " means that the distribution of particles in the acrylonitrile-butadiene-styrene graft copolymer of the core-shell structure exhibits a unimodal distribution characteristic.

The diene-based polymer core may be derived from a conjugated diene-based monomer, and specifically may be one prepared by emulsion-polymerizing the conjugated diene-based monomer. The diene polymer core may have an average particle diameter of 250 nm to 350 nm.

The conjugated diene-based monomer may be one or more selected from the group consisting of 1,3-butadiene, isoprene, chloroprene, and pyrene, and specifically may be 1,3-butadiene.

The aromatic vinyl compound may be at least one member selected from the group consisting of styrene,? -Methylstyrene,? -Ethylstyrene, p-ethylstyrene, vinyltoluene and derivatives thereof, and specifically styrene.

The vinyl cyan compound may be one or more selected from the group consisting of acrylonitrile, methacrylonitrile, ethacrylonitrile, and derivatives thereof, and specifically may be acrylonitrile.

The acrylonitrile-butadiene-styrene graft copolymer of the core-shell structure according to the present invention may be contained in the styrene resin composition in an amount of 15 to 30% by weight as described above. If the acrylonitrile-butadiene-styrene graft copolymer of the core-shell structure is included in the above range, the flowability of the styrene-based resin composition is excellent and the moldability in the production of a molded article using the acrylonitrile- , The impact strength of the produced molded article can be improved.

On the other hand, the acrylonitrile-butadiene-styrene graft copolymer of the core-shell structure is not particularly limited, and may be prepared by using a conventionally known method in the art, or a commercially available material may be used.

For example, when the acrylonitrile-butadiene-styrene graft copolymer of the core-shell structure is prepared and used, the acrylonitrile-butadiene-styrene graft copolymer of the core- And then graft-copolymerizing a shell containing an aromatic vinyl compound and a vinyl cyanide compound on the prepared diene-based polymer core.

The diene polymer core is not particularly limited and can be produced by a method commonly known in the art. For example, an additive such as ion-exchanged water, an emulsifier, a polymerization initiator, an electrolyte and a molecular weight adjuster is added to the conjugated diene monomer Or may be one prepared by emulsion polymerization.

The emulsion polymerization is not particularly limited and can be carried out by a conventional method known in the art. For example, additives such as ion-exchanged water, an emulsifier and a polymerization initiator are added to a conjugated diene monomer in a batch and reacted Or the reaction may be carried out by continuously feeding the components at the polymerization time.

Specifically, a mixture of 70 parts by weight to 120 parts by weight of ion exchange water, 0.2 parts by weight to 2.5 parts by weight of an emulsifier, 0.1 parts by weight to 1.5 parts by weight of a polymerization initiator, and 0.5 parts by weight of an electrolyte, based on 100 parts by weight of the conjugated diene monomer and the conjugated diene monomer, And 2 parts by weight of a polymerization initiator and 0.1 parts by weight to 1 part by weight of a molecular weight modifier are fed into a polymerization reactor at a temperature ranging from 50 ° C to 90 ° C. At this time, the conjugated diene-based monomer may be added in a batch with other constituent materials or additives and reacted, or the monomer may be added or continuously injected several times during the polymerization reaction.

The conjugated diene-based monomer may be as described above or may be included.

The polymerization initiator and the molecular weight modifier may be as described above or may be included.

Examples of the emulsifier include, but are not limited to, a combination of one or more selected from the group consisting of alkylaryl sulfonates, alkaline methyl alkyl sulfates, sulfonated alkyl esters, fatty acid soaps, and rosin acid alkali salts .

Examples of the electrolyte include, but are not limited to, potassium chloride, sodium chloride, potassium bicarbonate, potassium carbonate, potassium hydrogen sulfite, sodium hydrogen sulfite, sodium pyrophosphate, sodium pyrophosphate, tripotassium phosphate, trisodium phosphate, Potassium, and disodium hydrogenphosphate.

The shell containing the aromatic vinyl compound and the vinyl cyan compound is obtained by adding an aromatic vinyl compound, an additive such as a vinyl cyan compound, an emulsifier, a polymerization initiator, a molecular weight modifier and the like to the prepared diene-based polymer core and graft- Can be formed on the core.

The aromatic vinyl compound and the vinyl cyan compound may be as described above or included.

The additives such as the emulsifier, the polymerization initiator, and the molecular weight modifier may be as described above or may be included.

c) Heat resistant copolymer

The heat-resistant copolymer according to an embodiment of the present invention is obtained by copolymerizing a compound having a heat-resistant property with an aromatic vinyl compound and a vinyl cyan compound in a predetermined temperature range. The heat-resistant copolymer has a weight average molecular weight (Mw) To less than 200,000, and may have a glass transition temperature of 130 ° C to 150 ° C.

Specifically, the heat-resistant copolymer may be an N-phenylmaleimide-containing copolymer, an a-methylstyrene-containing copolymer, or a combination thereof, wherein the N-phenylmaleimide and? -Methylstyrene are heat- .

When the heat-resistant copolymer is a N-phenylmaleimide-containing copolymer, the heat-resistant copolymer may have a weight average molecular weight (Mw) of 100,000 to 130,000 and a glass transition temperature of 140 to 150 ° C.

Specifically, when the heat-resistant copolymer is an N-phenylmaleimide-containing copolymer, the heat-resistant copolymer preferably contains 30 to 50 parts by weight of N-phenylmaleimide per 100 parts by weight of the entire N-phenylmaleimide- part; 20 to 50 parts by weight of an aromatic vinyl compound and 5 to 20 parts by weight of a vinyl cyan compound. Herein, the above-mentioned bulk polymer may mean a copolymer obtained through bulk polymerization.

When the heat-resistant copolymer is an? -Methylstyrene-containing copolymer, the heat-resistant copolymer may have a weight average molecular weight (Mw) of 130,000 to 160,000 and a glass transition temperature of 130 to 140 ° C. Specifically, when the heat-resistant copolymer is an? -Methylstyrene-containing copolymer, the heat-resistant copolymer preferably contains 60 parts by weight to 80 parts by weight of? -Methylstyrene relative to 100 parts by weight of the entire? -Methylstyrene-containing copolymer. And 20 to 40 parts by weight of a vinyl cyanide compound. Here, the emulsion polymer may be a copolymer obtained through emulsion polymerization.

At this time, the? -Methylstyrene-containing copolymer may further comprise 1 to 10 parts by weight of an aromatic vinyl compound per 100 parts by weight of the entire? -Methylstyrene-containing copolymer.

The aromatic vinyl compound and the vinyl cyanide compound contained in the heat-resistant copolymer (N-phenylmaleimide-containing copolymer or? -Methylstyrene-containing copolymer) may be the same or as mentioned above.

The heat-resistant copolymer according to an embodiment of the present invention may include any copolymer obtained by copolymerizing a compound having a heat-resistant property with an aromatic vinyl compound and a vinyl cyan compound as described above. Specifically, N-phenylmaleimide-α -Methylstyrene-acrylonitrile copolymer (PMI-AMS-AN), N-phenylmaleimide-styrene-acrylonitrile copolymer (PMI-SAN) ) And an? -Methylstyrene-acrylonitrile-styrene copolymer (AMS-AN-SM).

The heat-resistant copolymer according to the present invention may be contained in the styrene resin composition in an amount of 5 to 20% by weight as described above. If the heat-resistant copolymer is contained in the styrene-based resin composition within the above range, heat resistance and impact strength of the molded article produced from the styrene-based resin composition can be improved.

On the other hand, the heat-resistant copolymer is not particularly limited and may be prepared by using a commonly known production method in the art, or a commercially available substance may be purchased and used.

When the above heat-resistant copolymer is prepared and used, it is not particularly limited, but it can be produced through bulk polymerization or emulsion polymerization depending on the compound having heat resistance properties to be used.

Specifically, when the heat-resistant copolymer is a N-phenylmaleimide-containing copolymer, the heat-resistant copolymer can be produced through bulk polymerization.

The bulk polymerization is not particularly limited and can be carried out by a conventional method known in the art, for example, by mixing N-phenylmaleimide with an aromatic vinyl compound and a vinyl cyanide, and a reaction medium, The reaction is carried out by heating at a temperature of 80 to 160 ° C to produce a polymerized product, and then the unreacted material and the reaction medium are removed.

The reaction medium may be as described above or may be included, and the mass polymerization may further include an additive such as a polymerization initiator and a molecular weight modifier, in addition to the above-described materials. The polymerization initiator and the molecular weight modifier May be as described above, or may be included.

When the heat-resistant copolymer is an? -Methylstyrene-containing copolymer, the heat-resistant copolymer can be produced through emulsion polymerization.

The emulsion polymerization is not particularly limited and may be prepared by a method commonly known in the art, as described above. Examples of the emulsion polymerization include a-methylstyrene, a vinyl cyan compound or a-methylstyrene, a vinyl cyan compound and an aromatic vinyl compound An additive such as an ion exchanged water, an emulsifier, a polymerization initiator, an electrolyte, and a molecular weight regulator is added to the reaction mixture at a temperature in the range of 50 to 90 占 폚, And the reaction can be carried out while being added.

Further, additives such as ion-exchanged water, an emulsifier, a polymerization initiator, an electrolyte and a molecular weight regulator are added to the monomer mixture in a batch and reacted at a temperature in the range of 50 ° C to 90 ° C to prepare a polymer. Then, a styrene monomer is added Followed by addition and reaction.

The additives such as the emulsifier, the polymerization initiator, the electrolyte, and the molecular weight regulator may be the same as or as described above.

The present invention also provides a molded article of a styrene type resin produced from the above styrene type resin composition.

The styrene resin molded article according to an embodiment of the present invention has an ESCR of 20 to 30 J / m in impact strength and 28 to 38% in tensile elongation according to ASTM D1693, And the chemical resistance measured in the test is 85 seconds to 160 seconds.

In the present invention, the impact strength means an ability of the molded article to resist breakage when an impact load is applied to the molded article of the styrene-based resin. The impact energy is applied to the molded article to measure the required energy until the molded article breaks And the measured value is divided by the sectional area of the molded article to obtain an impact strength value. Specifically, the impact strength may be measured according to ASTM D256.

In the present invention, the tensile elongation means the tensile capability of the molded article of the styrene-based resin, and can be obtained by calculating the ratio of the initial length to the length at the time of fracture after pulling the molded article until it is broken. Specifically, it may be measured in accordance with ASTM D638.

In the present invention, environmental stress cracking resistance (ESCR) is one of the measures for confirming the durability of the above-mentioned styrene-based resin molded product, which shows resistance to cracking of the molded product due to environmental factors externally applied. And the degree of the environmental stress cracking resistance can be confirmed by measuring the time taken for cracks to occur. Specifically, it may be measured in accordance with ASTM D1693.

The styrene-based resin molded article according to the present invention can exhibit excellent properties in terms of impact strength, tensile elongation, and environmental stress cracking property as described above, and can be easily applied to various industries requiring a styrenic resin have.

Hereinafter, the present invention will be described in more detail with reference to the following examples and experimental examples. However, the following examples and experimental examples are provided for illustrating the present invention, and the scope of the present invention is not limited thereto.

Example  One

65% by weight of an? -Methylstyrene-acrylonitrile copolymer (massive polymer, LG Chem) having a weight average molecular weight of 100,000 and a glass transition temperature of 122 ° C and an acrylonitrile-butadiene- 10% by weight of an α-methylstyrene-acrylonitrile copolymer (AMS-AN, LG Chem) having a weight average molecular weight of 150,000 and a glass transition temperature of 136 ° C was mixed with 25% by weight of a styrene copolymer (LG Chem) And a pellet shaped styrene resin molded article was produced at 240 캜 by using a twin screw extruder.

Example  2

acrylonitrile-styrene copolymer (AMS-AN-SM, LG Chem) having a weight average molecular weight of 150,000 and a glass transition temperature of 135 占 폚 in place of? -methylstyrene-acrylonitrile copolymer (AMS- Pellet-shaped styrene-based resin molded article was produced in the same manner as in Example 1, except that 10 wt%

Example  3

A-methylstyrene-acrylonitrile copolymer (PMI-AMS-AN) having a weight average molecular weight of 100,000 and a glass transition temperature of 140 占 폚 was used instead of? -methylstyrene-styrene-acrylonitrile copolymer -AN, manufactured by LG Chemical Co., Ltd.) was added in an amount of 10% by weight based on the weight of the styrene-based resin.

Example  4

N-phenylmaleimide-styrene-acrylonitrile copolymer (PMI-SAN, manufactured by LG Chem Co., Ltd.) having a weight average molecular weight of 100,000 and a glass transition temperature of 141 占 폚 was used instead of? -methylstyrene-styrene-acrylonitrile copolymer ) Was added to the above-mentioned mixture, a pellet-shaped styrene resin molded article was produced in the same manner as in Example 1 above.

Example  5

A styrene-acrylonitrile copolymer (AMS-AN) was prepared by using 70 wt% of an α-methylstyrene-acrylonitrile copolymer (mass polymer, LG Chem) having a weight average molecular weight of 100,000 and a glass transition temperature of 122 ° C., LG Chem) was added in an amount of 5% by weight based on the total weight of the styrene-based resin composition.

Example  6

Methylstyrene-acrylonitrile copolymer (bulk polymer, LG Chem) having a weight-average molecular weight of 100,000 and a glass transition temperature of 122 占 폚 was used as a monomer component in an amount of 70% by weight and N-phenylmaleimide- (PMI-AMS-AN, manufactured by LG Chemical Co., Ltd.) was added in an amount of 5% by weight, a pellet-shaped styrene resin molded article was produced.

Comparative Example  One

75% by weight of an? -Methylstyrene-acrylonitrile copolymer (massive polymer, LG Chem) having a weight average molecular weight of 100,000 and a glass transition temperature of 122 ° C and a core-shell structure of Unimodal acrylonitrile-butadiene- Styrene copolymer (LG Chem) were mixed to prepare a styrene resin composition, and a pellet-shaped styrene resin molded article was produced at 240 캜 by using a twin-screw extruder.

Comparative Example  2

72% by weight of an α-methylstyrene-acrylonitrile copolymer (mass polymer, LG Chem) having a weight average molecular weight of 100,000 and a glass transition temperature of 122 ° C. and a core-shell structure of Unimodal acrylonitrile-butadiene- 3% by weight of an α-methylstyrene-acrylonitrile copolymer (AMS-AN, LG Chem) having a weight average molecular weight of 150,000 and a glass transition temperature of 136 ° C was mixed with 25% by weight of a styrene copolymer (LG Chem) And a pellet shaped styrene resin molded article was produced at 240 캜 by using a twin screw extruder.

Comparative Example  3

50% by weight of an? -Methylstyrene-acrylonitrile copolymer (massive polymer, LG Chem) having a weight average molecular weight of 100,000 and a glass transition temperature of 122 ° C and a core-shell structure of unmodal acrylonitrile-butadiene- 25% by weight of an? -Methylstyrene-acrylonitrile copolymer (AMS-AN, LG Chem) having a weight average molecular weight of 150,000 and a glass transition temperature of 136 占 폚 was mixed with 25% by weight of a styrene copolymer (LG Chem) And a pellet shaped styrene resin molded article was produced at 240 캜 by using a twin screw extruder.

Comparative Example  4

50% by weight of an? -Methylstyrene-acrylonitrile copolymer (massive polymer, LG Chem) having a weight average molecular weight of 100,000 and a glass transition temperature of 122 ° C and a core-shell structure of unmodal acrylonitrile-butadiene- 25 weight% of styrene copolymer (LG Chem), 25 weight% of N-phenylmaleimide-? -Methylstyrene-acrylonitrile copolymer (PMI-AMS-AN, LG Chem) having a weight average molecular weight of 100,000 and a glass transition temperature of 140 占 폚 % Were mixed to prepare a styrene resin composition, which was then molded into a pellet-shaped styrene resin molded article at 290 ° C using a twin-screw extruder.

Comparative Example  5

65 weight% of an? -Methylstyrene-acrylonitrile copolymer (mass polymer, LG Chem) having a weight average molecular weight of 100,000 and a glass transition temperature of 122 占 폚, a bimodal acrylonitrile-butadiene having a core- -Methylstyrene-acrylonitrile copolymer (AMS-AN) having a weight average molecular weight of 150,000 and a glass transition temperature of 136 占 폚, 25% by weight of a styrene copolymer (average particle size 250 nm and average particle size 350 nm mixed structure, Manufactured by LG Chemical Co., Ltd.) were mixed to prepare a styrene resin composition, which was then molded into a pelletized styrene resin molded article at 240 캜 by using a twin screw extruder.

Comparative Example  6

65 weight% of an? -Methylstyrene-acrylonitrile copolymer (mass polymer, LG Chem) having a weight average molecular weight of 100,000 and a glass transition temperature of 122 占 폚, a bimodal acrylonitrile-butadiene having a core- -Methylstyrene-acrylonitrile-styrene copolymer (AMS-5) having a weight average molecular weight of 150,000 and a glass transition temperature of 135 占 폚, 25% by weight of a styrene copolymer (average particle diameter 250 nm and average particle size 350 nm mixed structure, AN-SM, and LG Chemical Co., Ltd.) were mixed to prepare a styrene resin composition, which was then molded into a pelletized styrene resin molded article at 240 캜 using a twin screw extruder.

Comparative Example  7

65 weight% of an? -Methylstyrene-acrylonitrile copolymer (mass polymer, LG Chem) having a weight average molecular weight of 100,000 and a glass transition temperature of 122 占 폚, and a core-shell structure of unmodal acrylonitrile-butadiene- Methylstyrene-acrylonitrile copolymer (AMS-AN, LG Chem) having a weight average molecular weight of 90,000 and a glass transition temperature of 136 占 폚, 25 weight% of a styrene copolymer (300 nm diene polymer core, % Were mixed to prepare a styrene resin composition, and a pellet-shaped styrene resin molded article was produced at 240 캜 by using a twin-screw extruder.

Comparative Example  8

65 wt% of an α-methylstyrene-acrylonitrile copolymer (mass polymer, LG Chem) having a weight average molecular weight of 100,000 and a glass transition temperature of 122 ° C, a core-shell structured unimodal acrylonitrile-butadiene- Methyl styrene-acrylonitrile copolymer (AMS-AN, LG Chem.) Having a weight average molecular weight of 200,000 and a glass transition temperature of 136 占 폚 was mixed with 25 weight% of a styrene- And a pellet-shaped styrene resin molded article was produced at 240 캜 by using a twin-screw extruder.

Experimental Example

In order to compare and analyze the characteristics of each of the styrene resin molded articles manufactured in Examples 1 to 6 and Comparative Examples 1 to 8, specimens corresponding to each test method were manufactured and the impact strength, tensile strength, tensile elongation, ), Heat resistance and chemical resistance were measured by the following methods. The results are shown in Table 1 below.

(1) Impact strength

Each of the styrene resin molded articles prepared in Examples 1 to 6 and Comparative Examples 1 to 8 was injected at 300 占 폚 to prepare 1/4 inch specimens. The impact strength of each specimen was measured in accordance with ASTM D256.

(2) Melt index

Each of the styrene-based resin molded articles prepared in Examples 1 to 6 and Comparative Examples 1 to 8 was injection-molded at 300 ° C to prepare 1/4 "specimens. Each of the specimens was heated at a temperature of 220 ° C according to ASTM D1238 The weight (g) of the resin melted for 10 minutes under a load of 10 kg was measured.

(3) Heat resistance

The heat resistance was measured by analysis of heat distortion temperature (HDT) and Vicat softening temperature.

The heat distortion temperature (HDT) was obtained by injecting each of the styrene-based resin molded articles prepared in Examples 1 to 6 and Comparative Examples 1 to 8 at 300 ° C to prepare 1/4 "specimens. Each of the specimens was subjected to ASTM D648 The softening temperature of the Vicott was measured by applying heat to each specimen and measuring the temperature at which the needle penetrated the specimen 1 mm.

(4) Tensile strength (TS) and tensile elongation (TE)

Each of the styrene-based resin molded articles prepared in Examples 1 to 6 and Comparative Examples 1 to 8 was injection-molded at 300 ° C to prepare respective specimens. The specimens were tested for tensile strength and tensile strength at a rate of 5 cm / min according to ASTM D638 Tensile elongation was measured.

(5) Chemical resistance

Each of the styrene resin molded articles manufactured in Examples 1 to 6 and Comparative Examples 1 to 8 was injection-molded to prepare respective specimens, and the specimens were prepared in accordance with ASTM D1693. After a 1.5% strain was applied in a low-temperature chamber maintained at 20 ° C, the sample was allowed to stand for 30 minutes, and thinner (O37u) was applied to measure the time at which the crack occurred.

division Impact strength
(J / m) Melt Index The tensile strength
(MPa) Tensile elongation
(%) Heat resistance Chemical resistance
(ESCR, sec)
HDT (° C) Vicat (° C) Example 1 21 8 578 34 99 111 123 Example 2 22 9 580 35 99 111 122 Example 3 20 7 563 30 100 113 150 Example 4 20 7 570 29 100 113 156 Example 5 25 10 559 37 98 110 101 Example 6 23 9 562 33 99 111 120 Comparative Example 1 25 11 550 38 97 108 50 Comparative Example 2 25 10 552 36 97 109 66 Comparative Example 3 16 4 600 15 101 116 245 Comparative Example 4 13 3 590 15 102 118 320 Comparative Example 5 16 12 578 25 99 111 117 Comparative Example 6 15 14 580 25 99 111 124 Comparative Example 7 12 12 518 36 96 107 65 Comparative Example 8 8 2 620 15 101 115 250

As shown in Table 1, the styrene resin molded articles of Examples 1 to 6 produced from the styrene resin composition according to the present invention had an impact strength, It has been confirmed that both excellent properties such as melt index (flowability), tensile strength, tensile elongation, heat resistance and chemical resistance are exhibited.

Specifically, as compared with the styrene-based resin molded article of Comparative Example 1 produced from the styrene-based resin composition containing no heat-resistant copolymer according to the present invention, the styrene-based resin composition containing the heat- (About 2.5 times) while exhibiting an impact strength, a melt index (flowability), a tensile strength, a tensile elongation and a heat resistance property of the same or somewhat superior level as the styrene resin molded articles of Examples 1 to 6 . This is because the heat-resistant copolymer according to the present invention is mixed with other components constituting the styrene-based resin composition, so that the conventional styrene-based resin has excellent chemical resistance without deteriorating the impact strength, tensile strength, tensile elongation, Can be significantly improved.

The styrene resin molded article of Comparative Example 2, which was produced using 3% by weight of the heat-resistant copolymer according to the present invention, but the amount of the heat-resistant copolymer used was lower than the minimum content of the present invention, The impact strength, tensile strength, tensile elongation, heat resistance and fluidity were somewhat lowered or similar to those of the styrene-based resin molded article of Example 6, but the chemical resistance of Comparative Example 1 in which the heat resistant copolymer was not used And exhibited characteristics similar to those of the styrene-based resin molded article.

On the contrary, in the case of the molded articles of the styrene-based resin compositions of Comparative Examples 3 and 4, in which the above-mentioned heat-resistant copolymer was used in an amount of more than 25% by weight, the styrene type resins of Examples 1 to 6 The molded article showed better values than the resin molded article, but at the same time, the impact strength, the melt index and the tensile elongation were remarkably decreased. This is because the proportion of the other components is reduced due to the addition of the excessive heat-resistant copolymer, and the balance between the respective constituents is disturbed. In particular, the heat-resistant copolymer shows an unstable state due to the high molecular weight and high heat resistance property . Therefore, in order to maintain excellent physical properties in a well-balanced manner, the range of the content of the heat-resistant copolymer in the present invention may be appropriate.

On the other hand, a comparison made from a styrenic resin composition containing a bimodal acrylonitrile-butadiene-styrene graft copolymer in place of the core-shell structured terminated acrylonitrile-butadiene-styrene graft copolymer according to the present invention In the case of the styrene-based resin molded articles of Examples 5 and 6, the tensile strength, the tensile elongation, the melt index (fluidity), the heat resistance, and the chemical resistance were similar to those of the styrene-based resin molded articles of Examples 1 to 6 The styrene resin molded article of Comparative Example 5 had a level of about 76% (compared to the styrene type resin molded article of Example 1), and the styrene type resin molded article of Comparative Example 6 had a level of about 68% 2 compared to the styrene-based resin molded article).

1 is a schematic cross-sectional view of a bimodal acrylonitrile-butadiene-styrene graft copolymer (FIG. 1A) of a core-shell structure and a bimodal acrylonitrile-butadiene-styrene graft copolymer 1 shows a TEM (transmission electron microscopic) measurement result of the thermosetting resin (FIG. 1B). Referring to FIG. 1, the core-shell structured terminated acrylonitrile-butadiene-styrene graft copolymer according to the present invention In the case of the bimodal acrylonitrile-butadiene-styrene graft copolymer (Fig. 1b) of the core-shell structure, particles having a relatively small size and a significantly larger size Particles showed aggregation phenomenon.

The results (Table 1 and FIG. 1) show that the distribution characteristics of the particles in the acrylonitrile-butadiene-styrene graft copolymer of the core-shell structure can affect impact strength characteristics, Acrylonitrile-butadiene-styrene graft copolymer of a core-shell structure having a Moon property can be an important factor for achieving the desired effect of the present invention.

The styrene-based resin composition of Comparative Example 7 prepared from the styrene-based resin composition containing the heat-resistant copolymer having the heat-resistant copolymer according to the present invention but having a weight average molecular weight of 90,000, which is lower than the minimum value of the weight- The resin molded article had a comparatively low chemical resistance as well as tensile strength, impact strength and heat resistance characteristics, and on the contrary, a comparison made from a styrenic resin composition containing a heat resistant copolymer having a weight average molecular weight of 200,000 higher than the maximum value of the weight average molecular weight In the case of the styrene-based resin molded article of Example 8, impact strength, melt index (flowability) and tensile elongation properties were significantly lowered. This is considered to be caused by the fact that kneading can not be performed smoothly during processing due to an excessively high molecular weight. Thus, in order to achieve the desired effect, the range of the weight average molecular weight in the heat-resistant copolymer may be an important factor.

Therefore, the molded article of the styrene-based resin produced from the styrene-based resin composition according to the present invention has the effect of significantly improving the chemical resistance while retaining the excellent impact strength, tensile strength and heat resistance characteristic inherent to the styrene-based resin molded article.

Claims (24)

a) 60 to 80% by weight of a styrenic copolymer having a weight average molecular weight (Mw) of 80,000 to 150,000;
b) from 15% to 30% by weight of an acrylonitrile-butadiene-styrene (ABS) graft copolymer of core-shell structure; And
c) 5 to 20% by weight of a heat-resistant copolymer having a weight average molecular weight (Mw) of less than 100,000 to less than 200,000.
The method according to claim 1,
The styrene-based copolymer is an α-methylstyrene-acrylonitrile copolymer (AMS-AN) comprising 60% by weight to 80% by weight of α-methylstyrene and 20% by weight to 40% by weight of acrylonitrile Wherein the styrene-based resin composition is a styrene-based resin.
The method according to claim 1,
Wherein the styrene-based copolymer is a copolymer of? -Methylstyrene-acrylonitrile containing 55% by weight to 75% by weight of? -Methylstyrene, 15% by weight to 35% by weight of acrylonitrile and 1% by weight to 15% -Styrene copolymer (AMS-AN-SM).
The method according to claim 1,
Wherein the styrene-based copolymer (a) has a glass transition temperature of 122 캜 to 126 캜.
The method according to claim 1,
(B) an acrylonitrile-butadiene-styrene (ABS) graft copolymer having a core-shell structure comprises 50 to 80% by weight of a diene-type polymer core and an aromatic vinyl compound grafted onto the core and a vinyl cyanide From 20% to 50% by weight of the shell comprising;
Wherein the shell contains the aromatic vinyl compound and the vinyl cyan compound in a weight ratio of 17: 3 to 11: 7.
The method of claim 5,
Wherein the diene-based polymer core is derived from a conjugated diene-based monomer.
The method of claim 6,
Wherein the conjugated diene monomer is at least one selected from the group consisting of 1,3-butadiene, isoprene, chloroprene, and pyrene.
The method of claim 5,
Wherein the diene-based polymer core has an average particle diameter of 250 nm to 350 nm.
The method according to claim 1,
Wherein the c) thermostable copolymer has a glass transition temperature of 130 ° C to 150 ° C.
The method according to claim 1,
Wherein the c) heat-resistant copolymer is a copolymer containing N-phenylmaleimide, an copolymer of? -Methylstyrene, or a combination thereof.
The method of claim 10,
Wherein the N-phenylmaleimide-containing copolymer has a weight average molecular weight (Mw) of 100,000 to 150,000.
The method of claim 10,
Wherein the N-phenylmaleimide-containing copolymer has a glass transition temperature of 140 ° C to 150 ° C.
The method of claim 10,
The N-phenylmaleimide-containing copolymer was prepared by mixing 100 parts by weight of the total N-phenylmaleimide-containing copolymer,
30 parts by weight to 50 parts by weight of N-phenylmaleimide;
20 to 50 parts by weight of an aromatic vinyl compound; And
And a vinyl cyanide compound in an amount of 5 parts by weight to 20 parts by weight.
The method of claim 10,
Wherein the? -Methylstyrene-containing copolymer has a weight average molecular weight (Mw) of 130,000 to 160,000.
The method of claim 10,
Wherein the? -Methylstyrene-containing copolymer has a glass transition temperature of 130 ° C to 140 ° C.
The method of claim 10,
The? -Methylstyrene-containing copolymer preferably contains, relative to 100 parts by weight of the entire? -Methylstyrene-containing copolymer,
60 parts by weight to 80 parts by weight of? -methylstyrene; And
Wherein the styrene-based resin composition is an emulsion polymer comprising 20 to 40 parts by weight of a vinyl cyan compound.
18. The method of claim 16,
Wherein the? -Methylstyrene-containing copolymer further comprises 1 to 10 parts by weight of an aromatic vinyl compound per 100 parts by weight of the entire? -Methylstyrene-containing copolymer.
The aromatic vinyl compound according to any one of claims 5, 13 and 17, wherein the aromatic vinyl compound is at least one member selected from the group consisting of styrene,? -Methylstyrene,? -Ethylstyrene and p- Based resin composition.
19. The method of claim 18,
Wherein the aromatic vinyl compound is styrene,? -Methylstyrene or a combination thereof.
The styrene-based resin composition according to any one of claims 5, 13, and 16, wherein the vinyl cyan compound is at least one selected from the group consisting of acrylonitrile, methacrylonitrile, and ethacrylonitrile .
The method of claim 20,
Wherein the vinyl cyan compound is acrylonitrile.
The method according to claim 1,
The c) thermostable copolymer may be selected from the group consisting of N-phenylmaleimide-a-methylstyrene-acrylonitrile copolymer (PMI-AMS-AN), N-phenylmaleimide- styrene- acrylonitrile copolymer (PMI- styrene-acrylonitrile-styrene copolymer (AMS-AN-SM) which is at least one selected from the group consisting of α-methylstyrene-acrylonitrile copolymer (AMS- Resin composition.
A styrene resin molded article produced from the styrene resin composition of claim 1.
24. The method of claim 23,
Wherein said styrene resin molded article has an impact resistance of 20 J / m to 30 J / m, a tensile elongation of 28% to 38%, and a chemical resistance measured by an environmental stress cracking (ESCR) test according to ASTM D1693 of 85 Sec to 160 sec. ≪ / RTI >

Images