KR101950708B1 - Thermoplastic Resin Composition and Molded Article Thereof - Google Patents

Abstract

More particularly, the present invention relates to a styrene-acrylonitrile (SAN) resin having a low molecular weight added to an acrylonitrile-butadiene-styrene (ABS) resin having heat resistance enhanced by adding a heat- ) Resin into a thermoplastic resin composition having improved fluidity while maintaining heat resistance, and a molded article obtained by molding the thermoplastic resin composition. According to the resin composition of the present invention, it is possible to obtain a thermoplastic resin composition and a molded article having improved heat resistance and reduced impact resistance without improving the fluidity of the heat resistant ABS resin.

Description

TECHNICAL FIELD [0001] The present invention relates to a thermoplastic resin composition,

The present invention relates to a styrenic thermoplastic resin composition having improved fluidity, and more particularly, to a styrenic thermoplastic resin composition having improved heat resistance by adding a heat-resistant resin to an acrylonitrile-butadiene-styrene (ABS) resin having a low molecular weight styrene- acrylonitrile ) Resin into a thermoplastic resin composition having improved fluidity while maintaining heat resistance, and a molded article obtained by molding the thermoplastic resin composition.

The styrenic thermoplastic resin is a resin synthesized by using styrene as a main raw material and copolymerizing with homopolymer or monomer to obtain advantages of the properties of each monomer. Examples of the styrene resin include General Purpose Polystyrene (GPPS) resin for polymerizing styrene alone and Expendable Polystyrene resin for foaming. High impact polystyrene (HIPS), which is a copolymer of styrene and butadiene rubber, ) Resin, styrene (styrene) and acrylonitrile (acrylonitrile) grafted on butadiene rubber.

In addition to this, ASA resin obtained by copolymerizing styrene and acrylonitrile based on acrylic rubber, styrene and methyl methacrylate (MMA: Methyl methacrylate) based on polybutadiene, Metha Acrylate (MBS) impact modifier, and acrylic impact modifier, which is a copolymer of methyl methacrylate (MMA) and acrylic acid monomer (Acrylate Monomer) based on acrylic rubber. Styrene has good processability, butadiene has impact resistance, and acrylonitrile has strength and chemical resistance.

The styrenic thermoplastic resin composition has been widely used for various purposes, and the ABS resin typified by a rubber-reinforced styrenic resin is excellent in mechanical properties and molding processability, and is widely used in electric and electronic parts, office equipment, and automobile parts . In particular, the ABS resin used for automotive parts uses heat-resistant ABS resin because the inside temperature of the vehicle rises due to the heat generated from the engine of the automobile and the heat caused by exposure to sunlight in the outdoors.

As a general method of imparting heat resistance to the ABS resin, a method of adding an α-methylstyrene (AMS) or maleimide monomer having excellent heat resistance in the ABS polymerization process and a method of adding the monomer having excellent heat resistance And then mixing the heat-resistant copolymer with the ABS resin. However, such heat-resistant ABS resin has a lower fluidity than general ABS resin, which not only limits the injection molding of a large-sized component or a complicated structure, but also causes quality and deformation problems of the appearance of the molded article.

In order to solve the problem of fluidity of such a heat-resistant ABS resin, a method of improving the fluidity by using a phosphoric acid ester compound is known. However, in a resin composition using a phosphoric acid ester compound, heat resistance is greatly lowered, So that a so-called " juicing " phenomenon of depositing on the surface of the molding remains.

Korean Patent Publication No. 2003-0005981 " Heat-resistant thermoplastic resin composition having excellent appearance quality "

An object of the present invention is to improve the lowered fluidity of heat-resistant ABS resin to which α-methylstyrene (AMS) or maleimide heat-resistant resin is applied as a matrix.

Another object of the present invention is to provide a heat-resistant ABS resin which is improved in fluidity, but does not deteriorate in heat resistance or satisfies a satisfactory range.

It is another object of the present invention to provide a heat-resistant ABS resin which is improved in flowability, has no or substantially no deterioration in impact resistance, and does not cause any additional problems of articles after molding.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art,

Heat resistant acrylonitrile-butadiene-styrene (ABS) resin; And a styrene-acrylonitrile (SAN) resin having a weight average molecular weight (Mw) of 10,000 to 70,000,

The heat-resistant acrylonitrile-butadiene-styrene (ABS) resin is obtained by copolymerizing a copolymer obtained by grafting acrylonitrile and styrene to a butadiene rubber polymer, a copolymer of α-methylstyrene (AMS) thermosetting resin and phenylmaleimide N-phenyl maleimide (PMI) thermosetting resin,

The heat-resistant acrylonitrile-butadiene-styrene (ABS) resin is a styrene-acrylonitrile (SAN) resin having a weight average molecular weight (Mw) in the range of 100,000 to 180,000, and the heat resistant acrylonitrile-butadiene- And 10 to 20% by weight,

The styrene-acrylonitrile (SAN) resin having a weight average molecular weight (Mw) of 10,000 to 70,000 is contained in an amount of 0.5 to 8 parts by weight per 100 parts by weight of the heat resistant acrylonitrile-butadiene-styrene (ABS) The present invention also provides a thermoplastic resin composition having improved flowability.

The present invention also provides a molded article obtained by molding the thermoplastic resin composition.

According to the thermoplastic resin composition of the present invention, it is possible to improve the fluidity without lowering heat resistance and impact strength. That is, it is possible to obtain a thermoplastic resin composition and a molded article to which the thermoplastic resin composition is applied, which solves the problems of the molding process due to the low fluidity which was a solution to conventional heat-resistant ABS, the problem of lowering of physical properties due to decomposition of resin due to excessive frictional heat, Do.

Hereinafter, the present invention will be described in more detail with reference to Examples. It is to be understood that the scope of the present invention is not limited by these examples in accordance with the gist of the present invention, and it is to be understood by those skilled in the art that the present invention is not limited thereto It will be obvious.

The present invention relates to a styrenic thermoplastic resin composition having improved fluidity, and more particularly, to a styrenic thermoplastic resin composition having improved heat resistance by adding a heat-resistant resin to an acrylonitrile-butadiene-styrene (ABS) resin having a low molecular weight styrene- acrylonitrile ) Resin to improve heat resistance and fluidity, and a molded article obtained by molding the thermoplastic resin composition. In the specification of the present invention, "acrylonitrile-butadiene-styrene (ABS) resin reinforced with heat resistance" and "heat resistant acrylonitrile-butadiene-styrene (ABS) Refers to a copolymer in which a part of the graft copolymer is substituted with a heat resistant monomer or a resin in which a heat resistant copolymer or a heat resistant resin is added to an acrylonitrile-butadiene-styrene (ABS) graft copolymer.

Hereinafter, the thermoplastic resin composition of the present invention will be described in detail.

Thermoplastic resin composition

1. Graft Copolymer

The graft copolymer of the present invention is a copolymer obtained by grafting an aromatic vinyl compound and a vinyl cyanide compound onto a rubbery polymer.

The rubbery polymer is not limited in its constitution, but may be a diene rubber such as polybutadiene, polystyrene-butadiene, polyacrylonitrile-butadiene, etc., and hydrogen added to the diene rubber Acrylic rubber such as a saturated rubber, a C1-C8 alkyl acrylate (Alkylacrylate), a polybutylacrylate, and an ethylhexylacrylate, an isoprene rubber, a chloroprene rubber, an ethylene-propylene Ethylene-propylene-ethylene (EPDM) rubber, and ethylene-propylene-diene (EPDM) rubber. Of these, polybutadiene among diene rubbers, Apply rubber. The content of the rubbery polymer is not limited in the present invention, but is preferably 30 to 75% by weight based on the total weight of the graft copolymer resin. When such a rubbery polymer is used, not only the graft ratio is high but also the impact strength and chemical resistance of the final molded product are excellent.

The aromatic vinyl compound grafted to the rubber polymer is not limited in its kind but may be selected from the group consisting of styrene, alpha-methylstyrene, beta-methylstyrene, p-methylstyrene, ethyl And is selected from the group consisting of styrene, ethylstyrene, hydroxystyrene, vinylxylene, monochlorostyrene, dichlorostyrene, dibromostyrene, and vinylnaphthalene. One or more of them may be used, and styrene is preferably used. The content of the aromatic vinyl compound is not limited in the present invention, but is suitably 20 to 65% by weight based on the total weight of the graft copolymer resin, and it is possible to efficiently increase the graft ratio with the rubbery polymer in the above range.

The composition of the vinyl cyanide grafted onto the rubbery polymer is not limited in its constitution. However, the vinylidene cyanide compound grafted to the rubbery polymer is not limited in its structure, but may be a saturated nitrile- , And acrylonitrile (acrylonitrile) is preferably used. The content of the vinyl cyanide compound is not limited in the present invention, but is preferably 5 to 30% by weight based on the total weight of the graft copolymer resin, and it is possible to efficiently increase the graft ratio with the rubber polymer in the above range.

Most preferably acrylonitrile-butadiene-styrene (ABS) grafted with acrylonitrile and styrene to a butadiene rubber polymer exhibiting excellent physical properties such as impact resistance and heat resistance. Copolymer ") may be used. The ABS resin used in one embodiment of the present invention is a styrene-acrylonitrile (SAN) grafted on butadiene rubber as shown in the following formula (1). However, the term 'ABS resin' is not necessarily limited to acrylonitrile-butadiene-styrene copolymer resin, but may be a resin composed of a copolymer of a vinyl cyanide compound-rubber polymer-aromatic vinyl compound It is also possible to extend the interpretation to

(1)

2. Heat-resistant reinforcement matrix (AMS / PMI heat-resistant resin)

As a general method of imparting heat resistance to the ABS resin, a method of adding an α-methylstyrene or maleimide monomer having excellent heat resistance in an ABS polymerization process and a method of adding a heat- There is a method of mixing the copolymer with an ABS resin. The copolymer having excellent heat resistance is usually prepared by copolymerizing an α-methylstyrene or maleimide monomer with a vinyl cyan compound such as acrylonitrile and / or an aromatic vinyl compound monomer such as styrene ≪ / RTI >

There has been proposed a method of producing a heat-resistant ABS resin by kneading a heat-resistant copolymer in the graft ABS resin. The method of producing such a heat-resistant ABS resin is a method of manufacturing a heat-resistant ABS resin by replacing part or the whole amount of styrene used for producing a heat-resistant copolymer for kneading with alpha-methylstyrene having excellent heat resistance (U.S. Patent Nos. 3,010,936 and 4,659,790) and a maleimide compound to prepare a heat resistant ABS resin (JP-A-58-206657, No. 63-162708, No. 63-235350 And U.S. Patent No. 4,757,109), a method of kneading with a polycarbonate resin, and a method of filling an inorganic material.

The heat-resistant copolymer of the present invention is prepared by copolymerizing an aromatic vinyl compound with a polymer monomer having heat resistance at a certain temperature range, or additionally, by copolymerizing a vinyl cyanide compound. Examples of the heat-resistant polymeric monomer include alpha-methylstyrene, N-phenyl maleimide, N-phenyl maleic acid and styrene maleic anhydride. At least one selected from the group consisting of The heat-resistant resin of the present invention additionally includes a copolymer based on a copolymer containing alpha-methylstyrene, including N-phenyl maleimide.

I) alpha-methylstyrene (hereinafter referred to as 'AMS') polymer

As the heat-resistant copolymer of the present invention, the AMS-based polymer is a copolymer of AMS and acrylonitrile (AN) or a copolymer of AMS, acrylonitrile (AN) and styrene, 50 to 80 parts by weight of a monomer, 20 to 50 parts by weight of acrylonitrile (AN) and 0 to 10 parts by weight of styrene at a predetermined ratio. When the content of the AMS monomer is less than 50 parts by weight, there may be a problem that the heat resistance is lowered and discolored to yellow when heated. When the content of the AMS monomer exceeds 80 parts by weight, AMS is continuously added to the resulting heat- There may be a problem that the combined structure ([AMS] - [AMS] - [AMS]: pyrolysis structure) is rapidly generated and easily decomposed into heat. If the content of acrylonitrile (AN) is less than 20 parts by weight, conversion and molecular weight may be deteriorated. If the amount of acrylonitrile (AN) is more than 50 parts by weight, acrylonitrile (AN) And the gel polymer is very weak to heat and may act as a foreign matter of red or black color upon heating, thereby damaging the appearance of the product. If the content of styrene is more than 10 parts by weight, the heat resistance may be lowered.

(2)

The present invention preferably comprises 15 to 40% by weight of an ABS graft copolymer, 20 to 85% by weight of an AMS-based heat resistant resin, and 0 to 65% by weight of a general SAN resin. When the content of the AMS-based polymer is less than 20% by weight, sufficient heat resistance can not be obtained. When the content of the AMS-based polymer is more than 85% by weight, there is a problem in that the impact strength is decreased due to the relative shortage of the grafted ABS polymer.

Ii) N-phenyl maleimide (PMI) polymer

As the heat-resistant resin of the present invention, the PMI-based polymer may be a copolymer of an N- (substituted) maleimide, a vinyl-based monomer and an unsaturated dicarboxylic acid. The PMI-based polymer generally refers to a ternary copolymer of N-phenylmaleimide-styrene-maleic anhydride as shown in the following formula (3): 45 to 55% by weight of PMI, 40 to 55% by weight of styrene To 50% by weight of maleic anhydride and 1 to 10% by weight of maleic anhydride, and most preferably 50% by weight of PMI, 45% by weight of styrene and 5% by weight of maleic anhydride, This is not a limitation.

(3)

The PMI-based polymer of the present invention can be used alone or in combination with an AMS-based polymer in an ABS resin. The PMI-based polymer may be used in an amount of 15 to 40% by weight of an ABS graft copolymer, 5 to 40% by weight of a PMI- Or 15 to 40% by weight of an ABS graft copolymer, 20 to 80% by weight of an AMS-based heat-resistant resin, 5 to 40% by weight of a PMI-based heat resistant resin and 0 to 60% by weight of a general SAN resin Do. In the above range, excellent heat resistance and impact resistance are exhibited.

3. General Matrix (SAN resin)

Typically, the matrix of the ABS resin is a copolymer of an aromatic vinyl compound and a vinyl cyanide compound.

The cyanide vinyl compound and the aromatic vinyl compound have been described above in the 'graft copolymer', and thus will not be described. The matrix copolymer of the present invention is a styrene-acrylonitrile (hereinafter referred to as 'SAN') copolymerized with styrene and acrylonitrile as an aromatic vinyl compound represented by the following chemical formula 4 ) Is applied. In this specification, the term "SAN resin" is not necessarily limited to styrene-acrylonitrile (SAN) copolymer resin, and may be a copolymer of vinyl cyanide-aromatic vinyl compound Explain that it is also possible to perform an extended analysis with a constructed resin.

(4)

The present invention uses a heat-resistant ABS resin which is applied to a matrix by applying an AMS-based and / or PMI-based heat-resistant resin to the ABS resin as a matrix or further including a general SAN resin having a weight average molecular weight (Mw) of 100,000 to 180,000 do.

4. Liquidity reinforcement matrix (low molecular weight SAN resin)

The flowability reinforcing matrix of the present invention is a copolymer of an aromatic vinyl compound and a vinyl cyanide compound having a low molecular weight.

Usually, the SAN copolymer as the matrix of the ABS copolymer has a weight average molecular weight (Mw) of 100,000 to 250,000 as described above. However, in order to impart heat resistance to the ABS resin, the AMS- and / or PMI-based heat- The thermoplastic resin produced by the application has excellent mechanical strength and heat resistance, but the fluidity is lowered, thereby causing a problem in productivity. Accordingly, the present invention aims to compensate for the decreased fluidity of the heat-resistant ABS resin by adding a certain amount of SAN resin having a weight average molecular weight (Mw) of 10,000 to 70,000.

Hereinafter, a possible production method for producing the thermoplastic resin of the present invention will be described.

Manufacturing method

Known methods for producing the copolymer resin include emulsion polymerization, suspension polymerization, solution polymerization, bulk polymerization, suspension polymerization and bulk polymerization, and emulsion polymerization and bulk polymerization.

As is well known from the above methods, emulsion polymerization and suspension polymerization are advantageous in that the reaction temperature is relatively easy to release due to the relatively easy release of reaction heat, and thus the polymer is less deformed due to heat. On the other hand, emulsifier, viscosity enhancer or coagulant And the added materials are not removed at the final stage, so that they remain as impurities in the final product, thereby deteriorating various physical properties. Further, after completion of the polymerization, additional processes such as dehydration, coagulation or drying to remove water as a reaction medium must be performed, and the removed water must be subjected to a wastewater treatment process. Therefore, it is economically more costly This process has the disadvantage of being a process.

On the other hand, it is difficult to control the reaction heat or the viscosity of the reaction solution by solution polymerization or bulk polymerization. However, since there is no additive used separately for the polymerization, residual impurities in the final product are so small that the physical properties are excellent, And unreacted monomers are recovered and used again. Therefore, unlike emulsion polymerization or suspension polymerization, production cost is very low.

In the present invention, it is not limited to any one of the above production methods, but it is common to produce by emulsion polymerization or bulk polymerization at the production site. In addition, the ABS base resin used in the examples of the present invention was prepared by emulsion polymerization, the AMS base heat resisting resin and PMI base heat resisting resin were produced by bulk polymerization, and the low molecular weight SAN resin was manufactured by suspension polymerization.

Hereinafter, the present invention will be described in detail with reference to examples.

Example

1. Preparation and preparation of composition

A. ABS graft copolymer

DP270 (manufactured by LG Chemical Co., Ltd.) manufactured by emulsion polymerization was used. The butadiene content of the resin was 60% and the volume average rubber particle size was 0.3 탆.

B. Heat resistant reinforcement SAN matrix

B-1. AMS-based heat-resistant copolymer

100 UH (manufactured by LL Chemical Co., Ltd.), which was prepared by bulk polymerization of alpha-methylstyrene (AMS) and acrylonitrile (AN), was used.

B-2. PMI-based heat-resistant copolymer

MS-NB (manufactured by Denka) composed of N-phenyl maleimide (PMI), styrene and maleic anhydride was used.

C. Generic SAN

92HR (manufactured by LG Chemical Co., Ltd.) manufactured by mass polymerization was used. The resin had an acrylonitrile (AN) content of 27% and a weight average molecular weight (Mw) of 130,000.

D. Liquidity reinforcement SAN resin

D-1. Low molecular weight SAN copolymer

EMI-100 (manufactured by SUNNY FC) manufactured by suspension polymerization was used, and the weight average molecular weight (Mw) was 45,000.

D-2. Low molecular weight SAN copolymer

EMI-200 (manufactured by SUNNY FC) manufactured by suspension polymerization was used, and the weight average molecular weight (Mw) was 60,000.

In Examples 1 to 7 and Comparative Examples 1 to 4, AMS heat-resistant resin (B-1) and PMI heat-resistant resin (B-2) were used alone or mixed with ABS graft copolymer (A) (D-1, D-2) were added to 100 parts by weight of a heat-resistant ABS resin optionally containing a low molecular weight SAN resin (C) In Table 1, A, B-1, B-2, C, D-1 and D-2 are the prepared thermoplastic resins.

<Table 1>

&Lt; Example 1 >

(A) 25 parts by weight of ABS graft copolymer (DP270, manufactured by LG Chem), (B-1) 60 parts by weight of AMS heat-resistant resin (100 UH, manufacturer: LG Chemical) 3 parts by weight of (D-2) low molecular weight SAN resin (EMI-200, manufacturer: Sunny FC) was added to 100 parts by weight of a heat-resistant ABS resin composed of (C) a general SAN resin (92HR, .

&Lt; Example 2 >

(A) 25 parts by weight of an ABS graft copolymer (DP270, manufacturer: LG Chemical) and 75 parts by weight of (B-1) AMS heat-resistant resin (100 UH, manufacturer: LG Chemical) 3 parts by weight of a low-molecular-weight SAN resin (EMI-100, manufacturer: Sunny FC) (D-1) was added to 100 parts by weight of heat-

&Lt; Example 3 >

(A) 25 parts by weight of an ABS graft copolymer (DP270, manufacturer: LG Chemical) and 75 parts by weight of (B-1) AMS heat-resistant resin (100 UH, manufacturer: LG Chemical) (EMI-100, manufacturer: Sunny FC) in an amount of 7 parts by weight based on 100 parts by weight of the heat-resistant ABS resin constituted by the component (D-1).

<Example 4>

(A) 25 parts by weight of an ABS graft copolymer (DP270, manufacturer: LG Chemical) and 75 parts by weight of (B-1) AMS heat-resistant resin (100 UH, manufacturer: LG Chemical) 3 parts by weight of (D-2) low molecular weight SAN resin (EMI-200, manufacturer: Sunny FC) was added to 100 parts by weight of the heat resistant ABS resin constituted by

&Lt; Example 5 >

(A) 25 parts by weight of an ABS graft copolymer (DP270, manufacturer: LG Chemical) and 75 parts by weight of (B-1) AMS heat-resistant resin (100 UH, manufacturer: LG Chemical) 7 parts by weight of (D-2) low-molecular-weight SAN resin (EMI-200, manufacturer: Sunny FC) was added to 100 parts by weight of the heat-

&Lt; Example 6 >

30 parts by weight of an ABS graft copolymer (DP270, manufactured by LG Chem), (B-1) 50 parts by weight of an AMS heat-resistant resin (100 UH, manufacturer: LG Chemical) (EMI-200, manufactured by Sunny FC, Inc.) was added to 100 parts by weight of heat-resistant ABS resin composed of (B-2) PMI heat-resistant resin (MS-NB manufactured by Denka) ).

&Lt; Example 7 >

30 parts by weight of an ABS graft copolymer (DP270, manufactured by LG Chem), (B-2) PMI heat-resistant resin (MS-NB, manufacturer: Denka) 35 Molecular sieve resin (EMI-200, manufacturer: Sunny FC) 3 (100 parts by weight) was added to 100 parts by weight of a heat-resistant ABS resin composed of (C) a general SAN resin (92HR manufactured by LG Chemical Co., By weight.

&Lt; Comparative Example 1 &

(A) 25 parts by weight of ABS graft copolymer (DP270, manufactured by LG Chem), (B-1) 60 parts by weight of AMS heat-resistant resin (100 UH, manufacturer: LG Chemical) And (C) 15 parts by weight of a general SAN resin (92HR, manufactured by LG Chem).

&Lt; Comparative Example 2 &

(A) 25 parts by weight of an ABS graft copolymer (DP270, manufacturer: LG Chemical) and 75 parts by weight of (B-1) AMS heat-resistant resin (100 UH, manufacturer: LG Chemical) .

&Lt; Comparative Example 3 &

30 parts by weight of an ABS graft copolymer (DP270, manufactured by LG Chem), (B-1) 50 parts by weight of an AMS heat-resistant resin (100 UH, manufacturer: LG Chemical) And 20 parts by weight of (B-2) PMI heat-resistant resin (MS-NB, manufacturer: Denka).

&Lt; Comparative Example 4 &

30 parts by weight of an ABS graft copolymer (DP270, manufactured by LG Chem), (B-2) PMI heat-resistant resin (MS-NB, manufacturer: Denka) 35 And (C) 35 parts by weight of a general SAN resin (92HR, manufacturer: LG Chemical).

2. Measurement of physical properties

Table 2 below shows the compositions of Examples 1 to 7 and Comparative Examples 1 to 4 by kneading in a twin-screw extruder at 240 DEG C, ), Impact strength (kgfcm / cm) and heat distortion temperature (HDT, 占 폚).

<Table 2>

The physical property evaluation conditions of the present invention are as follows.

(1) flowability: in accordance with ASTM D1238 was measured under the conditions of ^{220 ℃, 10 kgf / cm 2} .

(2) Impact strength: A 3.2 mm thick sample having a notch formed according to ASTM D256 was measured using an Izod impact strength meter (TINIUS OLSEN).

(3) Heat distortion temperature (HDT): The heat distortion temperature of a specimen having a thickness of 6.35 mm was measured at a rate of 18.6 kgf / cm ^{2 according} to ASTM D648 at a heating rate of 120 ° C / hr.

According to the above Tables 1 and 2, the fluidity of Comparative Examples 1 to 4 in which the fluidity of Examples 1 to 7 in which (D) the fluidity-reinforced low molecular weight SAN resin was added was increased by about 20 to 40% appear. On the other hand, it can be seen that the heat distortion temperature (HDT) for evaluating the heat resistance is hardly changed when Examples 1 to 7 and Comparative Examples 1 to 4 are compared. In addition, the values of the impact strength of Examples 1 to 7 were somewhat lower than those of Comparative Examples 1 to 4, but the degree of impact strength was not sufficient to affect macroscopic properties.

As a result of evaluating the results of the above physical properties comparison between Examples 2 and 3, it was found that (C) the amount of the fluidity-enhancing SAN resin was increased from 3 parts by weight to 7 parts by weight and the fluidity was 9.6 g / 10 min at 8.5 g / 10 min. While the HDT for evaluating the heat resistance showed a negligible decline from 102 ° C to 101 ° C, and the results are similar even when Examples 4 and 5 are compared. Therefore, the introduction of the low molecular weight SAN resin of the present invention showed an effect of improving the fluidity while keeping the heat resistance at a level hardly degraded.

Generally, when the weight average molecular weight (Mw) of the SAN resin is 100,000 or less, a large amount of low-molecular substances are contained in the resin and there is a problem of lowering the heat resistance. Therefore, the SAN resin of 100,000 or less is not used in the heat resistant ABS resin. However, in the present invention, a SAN resin having a weight average molecular weight (Mw) of 10,000 to 70,000 as a fluidity reinforcing matrix is added to a heat resistant ABS resin to which AMS and / or PMI resin is applied as a heat resistant reinforcing matrix at a predetermined composition ratio to prepare a thermoplastic resin composition As a result of the preparation, the fluidity was improved within a range where heat resistance was not a problem. In addition, it was predicted that the impact resistance could be reduced due to the low molecular weight resin, but it was confirmed that the test results were not deteriorated to the level of great concern.

The thermoplastic resin composition of the present invention is prepared by adding a SAN resin having a weight average molecular weight (Mw) in the range of 10,000 to 70,000 to a range of 0.5 to 10 parts by weight based on the total weight of the heat-resistant ABS resin to improve fluidity without deteriorating heat resistance and impact strength, Time workability and productivity can be expected to be improved.

Claims (4)

Heat resistant acrylonitrile-butadiene-styrene (ABS) resin; And
And a styrene-acrylonitrile (SAN) resin having a weight average molecular weight (Mw) of 10,000 to 70,000,
The heat-resistant acrylonitrile-butadiene-styrene (ABS) resin is obtained by copolymerizing a copolymer obtained by grafting acrylonitrile and styrene to a butadiene rubber polymer, a copolymer of α-methylstyrene (AMS) thermosetting resin and phenylmaleimide N-phenyl maleimide (PMI) thermosetting resin,
The heat-resistant acrylonitrile-butadiene-styrene (ABS) resin is a styrene-acrylonitrile (SAN) resin having a weight average molecular weight (Mw) in the range of 100,000 to 180,000, and the heat resistant acrylonitrile-butadiene- And 10 to 20% by weight,
The styrene-acrylonitrile (SAN) resin having a weight average molecular weight (Mw) of 10,000 to 70,000 is contained in an amount of 0.5 to 8 parts by weight per 100 parts by weight of the heat resistant acrylonitrile-butadiene-styrene (ABS) The thermoplastic resin composition according to claim 1,
The method according to claim 1,
The heat-resistant acrylonitrile-butadiene-styrene (ABS)
a) 15 to 40% by weight of an acrylonitrile-butadiene-styrene (ABS) graft copolymer;
b-1) 20 to 75% by weight of an alpha methyl styrene (AMS) type heat resistant resin; And
c) 10 to 20% by weight of a styrene-acrylonitrile (SAN) resin having a weight average molecular weight (Mw) of 100,000 to 180,000;
The thermoplastic resin composition according to claim 1,
The method according to claim 1,
The heat-resistant acrylonitrile-butadiene-styrene (ABS)
a) 15 to 40% by weight of an acrylonitrile-butadiene-styrene (ABS) graft copolymer;
b-1) 25 to 75% by weight of an alpha methyl styrene (AMS) type heat resistant resin;
b-2) 10 to 40% by weight of a thermoplastic resin based on phenylmaleimide (PMI); And
c) 10 to 20% by weight of a styrene-acrylonitrile (SAN) resin having a weight average molecular weight (Mw) of 100,000 to 180,000;
The thermoplastic resin composition according to claim 1,
A molded article obtained by molding the thermoplastic resin composition of claim 1.