KR20190071175A - Copolymer, method for preparing the same and thermoplastic resin composition comprising the same - Google Patents

Abstract

The present invention relates to: a copolymer which comprises, based on a total weight, 40 to 60 wt% of an aromatic vinyl-based monomer-derived unit, 25 to 40 wt% of a vinyl cyan-based monomer-derived unit, and 15 to 30 wt% of an alkyl (meth)acrylate-based monomer-derived unit, and has 96,000 to 110,000 g/mol of a weight average molecular weight; a method for manufacturing the same; and a thermoplastic resin composition comprising the same. The copolymer according to the present invention has excellent heat resistance and scratch resistance.

Description

TECHNICAL FIELD [0001] The present invention relates to a copolymer, a method for producing the same, and a thermoplastic resin composition containing the same. BACKGROUND ART [0002]

The present invention relates to a copolymer, a process for producing the same, and a thermoplastic resin composition containing the same, and more particularly, to a copolymer having excellent heat resistance and scratch resistance, a process for producing the same, and a thermoplastic resin composition containing the same.

In order to compensate the heat resistance of the acrylonitrile-butadiene-styrene copolymer (hereinafter referred to as 'ABS copolymer'), a thermoplastic resin composition comprising an ABS copolymer and a heat-resistant copolymer made of? -Methylstyrene and acrylonitrile A resin composition was used.

The? -Methylstyrene used in the production of the heat-resistant copolymer has a low depolymerization temperature, so emulsion polymerization is used which has a low polymerization temperature and is easy to control the reaction time.

However, the emulsion polymerization can produce a polymer having a large amount of additives, a long reaction time, a high coagulation temperature, an excellent processability, a nonuniform composition, and a large amount of impurities due to residual monomers in the produced copolymer There are disadvantages.

Although a method of producing a heat-resistant copolymer containing? -Methylstyrene by bulk polymerization has been proposed, it has a limited heat resistance, but is not excellent in scratch resistance and thus can not be used as an exterior material for automobiles and home appliances.

US 4,795,780B

An object of the present invention is to provide a copolymer having excellent heat resistance and scratch resistance, a method for producing the same, and a thermoplastic resin composition containing the same.

In order to solve the above problems, the present invention relates to a composition comprising 40 to 60% by weight of an aromatic vinyl-based monomer unit based on the total weight; 25 to 40% by weight of a vinyl cyan monomer-derived unit; And 15 to 30% by weight of an alkyl (meth) acrylate monomer-derived unit, and having a weight average molecular weight of 96,000 to 110,000 g / mol.

The present invention also provides a method for producing a polymer electrolyte membrane, comprising the steps of: preparing a reaction solution comprising an aromatic vinyl monomer, a vinyl cyan monomer, an alkyl (meth) acrylate monomer and a reaction solvent; And massively polymerizing the reaction solution at 100 to 120 ° C while continuously feeding the reaction solution to the reactor at a constant rate, wherein the aromatic vinyl monomer is used in an amount of 40 to 60 wt% based on the total weight of the monomers %; 25 to 40% by weight of the vinyl cyan monomer; And 15 to 30% by weight of the alkyl (meth) acrylate monomer, wherein the copolymer has a weight average molecular weight of 96,000 to 110,000 g / mol.

The present invention also relates to the aforementioned copolymer; And a graft copolymer comprising a conjugated diene polymer, an aromatic vinyl monomer unit, and a vinyl cyan monomer unit.

The copolymer according to the present invention is excellent in heat resistance and scratch resistance. Further, the thermoplastic resin composition containing the copolymer according to the present invention is excellent in heat resistance, scratch resistance and impact resistance.

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 as limited to ordinary or dictionary terms and the inventor may appropriately define the concept of the term in order to best describe its invention It should be construed as meaning and concept consistent with the technical idea of the present invention.

In the present invention, the weight average molecular weight can be measured relative to a standard polystyrene (PS) sample through gel permeation chromatography (waters breeze) using THF (tetrahydrofuran) as an eluent.

The average particle diameter of the graft copolymer in the present invention can be defined as a particle diameter corresponding to 50% or more of the volume accumulation amount in the particle diameter distribution curve of the particles.

In the present invention, the average particle size of the graft copolymer can be measured by laser diffraction particle size analysis.

In the present invention, the glass transition temperature can be measured using DSC (Differential Scanning Calorimeter) (TA Corporation, Discovery DSC 250).

1. Copolymer

The copolymer according to one embodiment of the present invention comprises, based on the total weight, 1) 40 to 60% by weight of an aromatic vinyl-based monomer-derived unit; 2) 25 to 40% by weight of a unit derived from a vinyl cyan monomer; And 3) 15 to 30% by weight of an alkyl (meth) acrylate monomer-derived unit, and 4) a weight average molecular weight of 96,000 to 110,000 g / mol.

Hereinafter, each component of the copolymer according to one embodiment of the present invention will be described in detail.

1) aromatic Vinyl-based  Monomer-derived unit

The aromatic vinyl-based monomer-derived units are contained in an amount of 40 to 60% by weight based on the total weight of the copolymer.

If the aromatic vinyl monomer-derived unit is contained in an amount of less than 40% by weight, the heat resistance of the copolymer is remarkably lowered, and if it exceeds 60% by weight, the scratch resistance of the thermoplastic resin composition containing the copolymer .

The aromatic vinyl-based monomer-derived unit is preferably contained in an amount of 45 to 55% by weight based on the total weight of the copolymer. When included in the above-mentioned range, a balance can be achieved between the heat resistance and the scratch resistance of the copolymer, and the impact resistance can be further improved.

The aromatic vinyl-based monomer-derived unit may be at least one derived unit selected from the group consisting of styrene,? -Methylstyrene,? -Ethylstyrene and p-methylstyrene, and the unit derived from? -Methylstyrene is preferably Do.

2) Vinyl Cyanide  Monomer-derived unit

The unit derived from the vinyl cyan monomer is contained in an amount of 20 to 45% by weight based on the total weight of the copolymer.

When the amount of the unit derived from the vinyl cyan monomer is less than 25% by weight, the reactivity is lowered and the polymerization conversion rate and the polymerization rate of the monomers are lowered. When the vinyl cyan monomer-derived unit is contained in an amount of more than 40% by weight, an insoluble gel containing a large amount of units derived from a vinyl cyan monomer is produced in the copolymer and thermal discoloration occurs.

The unit derived from the vinyl cyan monomer is preferably contained in an amount of 25 to 35% by weight based on the total weight of the copolymer. When the above-mentioned range is satisfied, the formation of insoluble gels originating from the vinyl cyan monomer-derived units and the thermal discoloration can be minimized, and the compatibility between the components of the copolymer can be further improved.

The unit derived from the vinyl cyan monomer may be at least one derived unit selected from the group consisting of acrylonitrile, methacrylonitrile, phenyl acrylonitrile and? -Chloroacrylonitrile, and the unit derived from acrylonitrile Unit is preferable.

3) Alkyl  ( Mat ) Acrylate series  Monomer

The alkyl (meth) acrylate monomer-derived units are contained in an amount of 15 to 30% by weight based on the total weight of the copolymer.

When the alkyl (meth) acrylate monomer-derived unit is contained in an amount of less than 15% by weight, the scratch resistance of the thermoplastic resin composition containing the copolymer is remarkably lowered. Also, when the alkyl (meth) acrylate monomer-derived units are contained in an amount of more than 30% by weight, heat resistance of the copolymer is remarkably lowered.

The unit derived from the alkyl (meth) acrylate monomer is preferably contained in an amount of 15 to 25% by weight based on the total weight of the copolymer. When included in the above-mentioned range, a balance can be achieved between heat resistance and scratch resistance, and the impact resistance can be further improved.

The unit derived from the alkyl (meth) acrylate monomer is at least one monomer selected from the group consisting of methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, decyl Acrylate, and lauryl (meth) acrylate, among which methyl methacrylate-derived units are preferable.

4) Weight average molecular weight

The copolymer according to an embodiment of the present invention has a weight average molecular weight of 96,000 to 110,000 g / mol.

When the weight average molecular weight of the copolymer is less than 96,000 g / mol, the mechanical properties such as impact resistance are deteriorated and the heat resistance is lowered. When the weight average molecular weight of the copolymer exceeds 110,000 g / mol, the flowability is deteriorated and the processability of the final resin is lowered.

The copolymer preferably has a weight average molecular weight of 97,000 to 105,000 g / mol, and more preferably 98,000 to 100,000 g / mol.

When the above-mentioned range is satisfied, mechanical properties such as scratch resistance and impact resistance and workability can be further improved.

The copolymer according to an embodiment of the present invention may have a glass transition temperature of 122 ° C or higher. When the temperature is higher than 122 ° C, the copolymer can impart excellent heat resistance to the thermoplastic resin composition.

2. Method for producing copolymer

The copolymer according to one embodiment of the present invention comprises: 1) preparing a reaction solution comprising an aromatic vinyl monomer, a vinyl cyan monomer, an alkyl (meth) acrylate monomer and a reaction solvent; And 2) bulk polymerization of the reaction solution at 100 to 120 ° C while continuously feeding the reaction solution to the reactor at a constant rate. In the process for producing a copolymer, the aromatic vinyl monomer 60% by weight; 25 to 40% by weight of the vinyl cyan monomer; And 15 to 30% by weight of the alkyl (meth) acrylate monomer, wherein the copolymer has a weight average molecular weight of 96,000 to 110,000 g / mol.

Hereinafter, each step of the method for producing a copolymer according to one embodiment of the present invention will be described in detail.

1) preparing a reaction solution

First, a reaction solution containing an aromatic vinyl monomer, a vinyl cyan monomer, an alkyl (meth) acrylate monomer and a reaction solvent is prepared.

40 to 60% by weight, based on the total weight of the monomers, of the aromatic vinyl monomer; 25 to 40% by weight of the vinyl cyan monomer; And 15 to 30% by weight of the alkyl (meth) acrylate-based monomer.

When the aromatic vinyl monomer is contained in an amount of less than 40% by weight, the heat resistance of the copolymer is significantly lowered, and when it exceeds 60% by weight, the scratch resistance of the thermoplastic resin composition containing the copolymer is remarkably lowered .

The aromatic vinyl-based monomer is preferably included in an amount of 45 to 55% by weight based on the total weight of the monomers.

The aromatic vinyl-based monomer may be at least one member selected from the group consisting of styrene,? -Methylstyrene,? -Ethylstyrene, and p-methylstyrene. Of these,? -Methylstyrene is preferable.

When the amount of the vinyl cyan monomer is less than 25% by weight, the reactivity is lowered, and the polymerization conversion rate and polymerization rate of the monomers are lowered. When the vinyl cyan monomer is contained in an amount of more than 40% by weight, an insoluble gel containing a large amount of units derived from a vinyl cyan monomer is produced in the copolymer, and heat discoloration occurs.

The vinyl cyan monomer is preferably contained in an amount of 25 to 35% by weight based on the total weight of the monomers.

The vinyl cyan monomer may be at least one member selected from the group consisting of acrylonitrile, methacrylonitrile, phenyl acrylonitrile and? -Chloroacrylonitrile, and acrylonitrile is particularly preferable.

If the alkyl (meth) acrylate monomer is contained in an amount of less than 15% by weight, the scratch resistance of the thermoplastic resin composition containing the copolymer remarkably decreases. When the alkyl (meth) acrylate monomer is contained in an amount of more than 30% by weight, the heat resistance of the copolymer is remarkably lowered.

The alkyl (meth) acrylate-based monomer is preferably contained in an amount of 15 to 25% by weight based on the total weight of the monomers.

The alkyl (meth) acrylate monomer may be at least one monomer selected from the group consisting of methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, decyl (Meth) acrylate, and among them, methyl methacrylate is preferable.

The reaction solvent may be an inert organic solvent and may be an alcohol; Ketones such as methyl ethyl ketone; Aromatic hydrocarbons such as petroleum ether, ethylbenzene and toluene; Or a halide such as carbon tetrachloride or chloroform. Of these, aromatic hydrocarbons are preferable.

The reaction solvent may be 15 parts by weight or less, 1 to 15 parts by weight or 5 to 13 parts by weight, preferably 5 to 13 parts by weight, based on 100 parts by weight of the total of the monomers. When the above-mentioned range is satisfied, the polymerization viscosity in the polymerization reaction system is appropriately maintained, and the polymerization can proceed stably.

The reaction solution may further contain an initiator.

The initiator may be selected from the group consisting of t-butylperoxy-2-ethylhexanoate, 1,1-bis (t-butylperoxy) cyclohexane, 1,1- (T-butylperoxy) -3,3,5-trimethylcyclohexane or 2,2-bis (t-butylperoxy) butane, and among these, t-Butyl peroxy-2-ethyl hexanoate is preferred.

The initiator may be 0.01 to 0.5 parts by weight, 0.05 to 0.4 parts by weight or 0.1 to 0.3 parts by weight, preferably 0.1 to 0.3 parts by weight, based on 100 parts by weight of the total of the monomers. When the above range is satisfied, the polymerization conversion ratio and the weight average molecular weight can be appropriately controlled.

2) Step of bulk polymerization

Then, the reaction solution is subjected to bulk polymerization at 100 to 120 DEG C while continuously feeding the reaction solution to the reactor at a constant rate.

If the bulk polymerization is carried out at less than 100 캜, the reaction time increases and the process efficiency decreases. If the bulk polymerization is carried out at a temperature higher than 120 DEG C, a large amount of oligomer is generated and the glass transition temperature is lowered, and a copolymer having a desired weight average molecular weight in the present invention can not be produced.

The massive polymerization may be continuous bulk polymerization. Specifically, it may be continuous bulk polymerization in which monomers to be polymerized are continuously charged at a constant rate by using a continuous reactor in which four or more stirring vessels are connected in series. When the continuous bulk polymerization is carried out by the above-mentioned method, there is an advantage that the polymerization conversion ratio is increased and the content of the residual monomer is decreased.

The method for producing a copolymer according to another embodiment of the present invention may further comprise the step of putting the polymerization product obtained by the bulk polymerization into a devolatilizing tank and volatilizing the unreacted monomers and the reaction solvent to separate the polymer.

The devolatilizer is equipped with a heat exchanger and is operated at a temperature of 220 to 260 ° C and a pressure of less than 25 torr, preferably at a temperature of 230 to 250 ° C and a pressure of less than 20 torr, more preferably at a temperature of 235 to 245 ° C The copolymer can be separated by volatilizing the unreacted monomers and the reaction solvent contained in the polymerization product while maintaining the vacuum at a pressure of less than 16 torr.

The copolymer prepared by the above process for producing a copolymer has a weight average molecular weight of 96,000 to 110,000 g / mol, preferably 97,000 to 105,000 g / mol, and more preferably 98,000 to 100,000 g / mol.

The reason for the numerical limitation is as described in the description of the copolymer.

3. Thermoplastic resin composition

The thermoplastic resin composition according to another embodiment of the present invention comprises: 1) a copolymer according to one embodiment of the present invention; And 2) a graft copolymer comprising a conjugated diene polymer, an aromatic vinyl monomer-derived unit, and a vinyl cyan monomer-derived unit.

1) Copolymer

The description of the copolymer according to one embodiment of the present invention is as follows. Copolymer ".

2) Graft  Copolymer

The graft copolymer includes a conjugated diene-based polymer, an aromatic vinyl-based monomer-derived unit, and a vinylcyanide monomer-derived unit.

The graft copolymer can impart excellent chemical resistance, mechanical properties and processability to the thermoplastic resin composition.

The conjugated diene polymer may include a conjugated diene polymer modified by graft polymerizing an aromatic vinyl monomer and a vinyl cyan monomer to a conjugated diene polymer produced by polymerization of a conjugated diene monomer.

The conjugated diene-based monomer may be at least one member selected from the group consisting of 1,3-butadiene, isoprene, chloroprene and piperylene, and 1,3-butadiene may be preferred.

The graft copolymer preferably contains two or more kinds of conjugated diene polymers having different average particle diameters, and preferably includes a small diameter conjugated diene polymer having a small average particle diameter and a large diameter conjugated diene polymer having a large average particle diameter .

The small diameter conjugated diene-based polymer may have an average particle diameter of 0.01 to 0.15 탆, 0.05 to 0.12 탆, or 0.08 to 0.1 탆, of which 0.8 to 0.1 탆 is preferable. When the above-described range is satisfied, surface gloss can be further improved.

The above-mentioned large diameter conjugated diene polymer may have an average particle diameter of 0.2 to 0.5 mu m, 0.25 to 0.4 mu m, or 0.3 to 0.35 mu m, preferably 0.3 to 0.35 mu m. When the above-mentioned range is satisfied, the mechanical properties of the graft copolymer can be further improved.

The conjugated diene polymer may be contained in an amount of 45 to 70% by weight, 50 to 65% by weight or 55 to 60% by weight based on the total weight of the graft copolymer, preferably 55 to 60% by weight Do. When the above-mentioned range is satisfied, the impact resistance and processability of the graft copolymer can be further improved.

The content of the conjugated diene polymer may mean the sum of the small diameter conjugated diene polymer and the large diameter conjugated diene polymer.

The aromatic vinyl-based monomer-derived unit may be at least one derived unit selected from the group consisting of styrene,? -Methylstyrene,? -Ethylstyrene, and p-methylstyrene, and styrene-derived units are preferred.

The aromatic vinyl-based monomer-derived unit may be contained in an amount of 15 to 40% by weight, 20 to 35% by weight or 25 to 30% by weight based on the total weight of the graft copolymer, and 25 to 30% . When the above range is satisfied, the chemical resistance, stiffness, impact resistance, workability and surface gloss of the thermoplastic resin composition can be further improved.

The unit derived from the vinyl cyan monomer may be at least one derived unit selected from the group consisting of acrylonitrile, methacrylonitrile, phenyl acrylonitrile and? -Chloroacrylonitrile, and the unit derived from acrylonitrile Unit is preferable.

The unit derived from the vinyl cyan monomer may be contained in an amount of 5 to 25% by weight, 7 to 20% by weight or 10 to 15% by weight based on the total weight of the graft copolymer, and 10 to 15% . When the above range is satisfied, the chemical resistance, stiffness, impact resistance, workability and surface gloss of the thermoplastic resin composition can be further improved.

The graft copolymer may have a graft rate of 20 to 50%, 25 to 45%, or 30 to 40%, preferably 30 to 40%. When the above-mentioned range is satisfied, it is possible to balance the thermal stability and the mechanical properties of the graft copolymer.

The weight average molecular weight of the shell of the graft copolymer may be 60,000 to 90,000 g / mol, 65,000 to 85,000 g / mol or 70,000 to 80,000 g / mol, and preferably 70,000 to 80,000 g / mol. When the above-mentioned range is satisfied, there is an advantage that mechanical properties and processability are better.

The graft copolymer may be prepared by polymerizing an aromatic vinyl monomer and a vinyl cyan monomer in the presence of a conjugated diene polymer by at least one method selected from the group consisting of emulsion polymerization, suspension polymerization and bulk polymerization, It is preferable to be produced by emulsion polymerization.

The thermoplastic resin composition may contain the copolymer and the graft copolymer in a weight ratio of 80:20 to 55:45, 75:25 to 60:40, or 70:30 to 65:35, and 70:30 To 65:35 by weight. When the above-mentioned range is satisfied, a molded article having excellent heat resistance, scratch resistance and impact resistance can be produced.

The molded article made of the thermoplastic resin composition may have a pencil hardness of not less than HB and a heat resistance according to ASTM D648 of 97 DEG C or more. When the above-mentioned range is satisfied, a molded article having excellent heat resistance and scratch resistance can be produced.

The pencil hardness can be determined by whether the pencil is fixed with a load of 0.5 Kg and an angle of 45 and then scratching the surface of the specimen with the pencil hardness to visually grasp it.

Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

≪ Preparation of Copolymer >

Example  1 to Example  4, Comparative Example  1 and Comparative Example  2

A reaction solution containing 90 parts by weight of a monomer mixture containing the components listed in Table 1, 10 parts by weight of toluene and 2 parts by weight of t-butylperoxy-2-ethylhexanoate as an initiator was fed at a constant rate for 24 hours at 110 DEG C And the polymerization was continued while being continuously fed into a reactor set at < RTI ID = 0.0 > After the polymerization was completed, the product was poured into a volatilizer set at 240 DEG C to remove unreacted monomers and reaction solvent, and a copolymer in the form of a pellet was obtained.

division alpha -methyl styrene
(weight%) Acrylonitrile
(weight%) Methyl methacrylate
(weight%) Example 1 55 30 15 Example 2 50 30 20 Example 3 45 30 25 Example 4 40 30 30 Comparative Example 1 60 30 10 Comparative Example 2 30 30 40

Comparative Example  3

100 UH (trade name, manufactured by LG Chem) containing an a-methylstyrene-derived unit and an acrylonitrile-derived unit was used as Comparative Example 3.

Comparative Example  4

Polymethyl methacrylate (trade name: EH910, manufacturer: LG MMA, MFI = 1.0) was used as Comparative Example 4.

≪ Production of Thermoplastic Resin Composition >

Example  5 - Example  8

30 parts by weight of an ABS copolymer (trade name: DP271, manufactured by LG Chemie) and 0.3 parts by weight of an antioxidant were charged into a twin-screw extruder (28Φ) set at 240 DEG C as a copolymer and graft copolymer shown in the following Table 2, To prepare a thermoplastic resin composition.

division Example 5
(Parts by weight) Example 6
(Parts by weight) Example 7
(Parts by weight) Example 8
(Parts by weight) Copolymer Example 1 70 - - - Example 2 - 70 - - Example 3 - - 70 - Example 4 - - - 70

Comparative Example  5 - Comparative Example  9

30 parts by weight of an ABS copolymer (trade name: DP271, manufactured by LG Chemie) as a copolymer and a graft copolymer shown in the following Table 3 were fed into a twin-screw extruder (28Φ) set at 240 ° C to prepare a thermoplastic resin composition in the form of a pellet .

division Comparative Example 5
(Parts by weight) Comparative Example 6
(Parts by weight) Comparative Example 7
(Parts by weight) Comparative Example 8
(Parts by weight) Comparative Example 9
(Parts by weight) Copolymer Comparative Example 1 70 - - - - Comparative Example 2 - 70 - - - Comparative Example 3 30 50 70 Comparative Example 4 40 20 -

Experimental Example  One

The physical properties of the copolymers obtained in Examples and Comparative Examples were measured by the following methods.

(1) Weight average molecular weight (g / mol): Measured relative to standard PS (standard polystyrene) samples through GPC (Gel Permeation Chromatography, waters breeze) using THF (tetrahydrofuran)

(2) Glass transition temperature (占 폚): Measured using DSC (Differential Scanning Calorimeter) (TA company, Discovery DSC 250).

division Weight average molecular weight (g / mol) Glass transition temperature (캜) Example 1 100,000 125.1 Example 2 98,000 124.5 Example 3 97,000 123.4 Example 4 96,000 122.3 Comparative Example 1 102,000 125.5 Comparative Example 2 83,000 115.6 Comparative Example 3 100,000 125.0 Comparative Example 4 130,000 -

Referring to Table 4, in the case of Examples 1 to 4 and Comparative Examples 1 and 2, as the content of methyl methacrylate increases, the weight average molecular weight decreases, and as the content of -methylstyrene increases, It was confirmed that the transition temperature was increased.

Experimental Example  2

The thermoplastic resin compositions obtained in Examples and Comparative Examples were injected to prepare specimens, and the properties were measured by the following methods.

(3) Izod impact strength (1/4 ", kg · cm / cm): Measured according to ASTM D256.

(4) Tensile strength (kgf / cm2): Measured according to ASTM D638.

(5) Heat resistance (HDT, ° C): Measured according to ASTM D648.

(6) Pencil hardness: The pencil was fixed with a load of 0.5 Kg and an angle of 45 [deg.], And then the surface of the test piece was scratched by pencil hardness to judge whether or not it was scratched with the naked eye.

division Izod impact strength
(Kg · cm / cm) The tensile strength
(Kgf / cm2) Heat resistance
(° C) Pencil hardness Example 5 16.3 541 99.5 HB Example 6 16.1 540 98.7 HB Example 7 15.8 538 98.0 HB-F Example 8 15.4 538 97.4 HB-F Comparative Example 5 16.4 545 99.8 B Comparative Example 6 13.2 531 92.7 F Comparative Example 7 11.0 496 86.8 HB Comparative Example 8 12.8 513 93.0 B Comparative Example 9 16.1 537 99.7 2B

Referring to Table 5, it was found that the impact strength, tensile strength, heat resistance and pencil hardness of the specimens of Examples 5 to 8 were all excellent. In particular, in Example 5, it was found that the impact strength and the tensile strength were remarkably excellent.

In Comparative Example 5 containing the copolymer of Comparative Example 1 containing a small amount of methyl methacrylate, the impact strength, tensile strength and heat resistance were excellent, but the pencil hardness was lowered.

In the case of Comparative Example 6 containing the copolymer of Comparative Example 2 containing an excess amount of methyl methacrylate, the pencil hardness was excellent, but the impact strength, tensile strength and heat resistance were all lowered.

The impact strength, the tensile strength, the heat resistance and the pencil hardness were all lowered in the case of Comparative Example 7 including Comparative Example 3 which is a heat resistant copolymer and Comparative Example 4 which is an scratch resistant copolymer,

In Comparative Example 9 including Comparative Example 3 which is a heat-resistant copolymer, the impact strength, the tensile strength and the heat resistance were excellent, but the pencil hardness was remarkably decreased.

Claims (9)

With respect to the total weight,
40 to 60% by weight of an aromatic vinyl-based monomer-derived unit;
25 to 40% by weight of a vinyl cyan monomer-derived unit; And
And 15 to 30% by weight of an alkyl (meth) acrylate-based monomer-derived unit,
A copolymer having a weight average molecular weight of 96,000 to 110,000 g / mol.
The method according to claim 1,
The copolymer
With respect to the total weight,
45 to 55% by weight of the aromatic vinyl-based monomer-derived unit;
25 to 35% by weight of the vinyl-based monomer-derived unit; And
And 15 to 25% by weight of the alkyl (meth) acrylate monomer-derived unit,
And a weight average molecular weight of 97,000 to 105,000 g / mol.
The method according to claim 1,
Wherein the copolymer has a glass transition temperature of 122 ° C or higher.
Preparing a reaction solution comprising an aromatic vinyl monomer, a vinyl cyan monomer, an alkyl (meth) acrylate monomer, and a reaction solvent; And
And a step of mass-polymerizing the reaction solution at 100 to 120 ° C. while continuously feeding the reaction solution to the reactor at a constant rate, the method comprising:
40 to 60% by weight, based on the total weight of the monomers, of the aromatic vinyl monomer; 25 to 40% by weight of the vinyl cyan monomer; And 15 to 30% by weight of the alkyl (meth) acrylate monomer,
Wherein the copolymer has a weight average molecular weight of 96,000 to 110,000 g / mol.
The method of claim 4,
With respect to the total weight of the monomers,
45 to 55% by weight of the aromatic vinyl-based monomer;
25 to 35% by weight of the vinyl cyan monomer; And
And 15 to 25% by weight of the alkyl (meth) acrylate monomer.
The method of claim 4,
Wherein the copolymer has a weight average molecular weight of 97,000 to 105,000 g / mol.
A copolymer according to any one of claims 1 to 3; And
A thermoplastic resin composition comprising a graft copolymer comprising a conjugated diene polymer, an aromatic vinyl monomer-derived unit and a vinyl cyan monomer-derived unit.
The method of claim 7,
Wherein the thermoplastic resin composition comprises the copolymer and the graft copolymer in a weight ratio of 80:20 to 55:45.
A thermoplastic resin composition produced by the thermoplastic resin composition according to claim 7 or 8,
The pencil hardness is at least HB,
A thermoplastic resin molded article according to ASTM D648 having a heat resistance of 97 deg.