KR20030056478A - Thermoplastic Resin Composition having Advanced Chemical Resistance and Impact Strength and Process for Preparing the Same - Google Patents

Abstract

PURPOSE: A thermoplastic resin composition having improved chemical resistance, gloss and impact resistance is provided. A process for preparing the resin composition is also provided. CONSTITUTION: The process for preparing the thermoplastic resin composition comprises the steps of: (1) carrying out a graft copolymerization of an rubbery polymer latex having a gel content of 75 to 95 wt% and an average particle diameter of 0.10 to 0.20 micrometers and an aromatic vinyl-unsaturated nitrile based graft monomer mixture to obtain a first graft copolymer; (2) carrying out a graft copolymerization of the first graft copolymer with a rubbery polymer latex having a gel content of 65 to 85 wt% and an average particle diameter of 0.25 to 0.35 micrometers and an aromatic vinyl-unsaturated nitrile based graft monomer mixture to obtain a second graft copolymer; and (3) carrying out a graft copolymerization of the second graft copolymer with a rubbery polymer latex having a gel content of 50 to 70 wt% and an average particle diameter of 0.45 to 0.65 micrometers and an aromatic vinyl-unsaturated nitrile based graft monomer mixture to obtain a third graft copolymer, wherein the aromatic vinyl-unsaturated nitrile based graft monomer mixture comprises 55 to 70 wt% of styrene and 45 to 30 wt% of acrylonitrile.

Description

Thermoplastic Resin Composition having Advanced Chemical Resistance and Impact Strength and Process for Preparing the Same}

Field of invention

The present invention relates to a thermoplastic resin composition excellent in impact resistance, and particularly excellent in chemical resistance, and a method for producing the same. More specifically, the present invention provides excellent impact resistance, chemical resistance and glossiness by grafting and polymerizing three butadiene-based rubbery polymers having different average particle diameters and gel contents in three steps with an aromatic vinyl-unsaturated nitrile-based graft monomer mixture. The present invention relates to a thermoplastic resin composition and a method for producing the same.

Background of the Invention

ABS resin is manufactured by graft copolymerization of styrene and acrylonitrile monomer to butadiene-based rubber polymer, and has excellent impact resistance and processability, and excellent mechanical strength and heat deformation temperature, so it is widely used in electric, electronic products, automobile parts, and office equipment. Is being used. When ABS resin is used in a product which can come into contact with detergents or other chemicals such as materials for washing machines and refrigerators, not only high impact strength but also excellent chemical resistance are required.

In the case of ABS resin, it is a material that maintains excellent balance of physical properties, but it is difficult to satisfy satisfactory impact strength and chemical resistance at the same time with general production methods.

Patent Publication No. 90-11850 applies a method of improving the impact resistance of ABS resin to increase the rubber particle diameter or lower the gel content of the rubbery polymer, but it is difficult to control the physical properties of the graft copolymer as well as the impact resistance. There is a problem that the balance of physical properties such as glossiness and glossiness is still lowered. In addition, when the resin is manufactured using a rubbery polymer having a general average particle size, general physical property balance is maintained, but neither high impact strength nor high gloss are satisfactory.

In addition, Japanese Patent Laid-Open No. 59-202211 discloses a method of graft polymerization of two kinds of rubbery polymer latexes having different particle diameters. No. 59-202211 discloses a method for graft polymerization of a rubbery polymer having a particle size of 0.1 to 0.4 mu m and a rubbery polymer latex having a particle size of 0.4 to 1.0 mu m by an emulsion polymerization method. However, because the resin composition thus prepared has a larger surface area per volume of the small-size rubbery polymer than that of the large particle size, the graft reaction is likely to occur on the particles of the small-size rubbery polymer, while the graft reaction does not sufficiently occur on the particles of the large-size rubbery polymer. In addition, since the compatibility between the large-diameter rubbery polymer and the matrix is insufficient, the impact resistance is not excellent.

Patent Publication No. 91-15609 compensates for these problems by using two kinds of rubbery polymers having different particle diameters, but the surface area varies according to the size of the rubber particle size, and the graft copolymer contains a large amount of ungrafted rubber component. Glossiness as well as the impact resistance is not satisfactory.

The present inventors have developed and applied for a method of manufacturing a copolymer using three butadiene-based rubbery polymers having different average particle diameters and different physical properties in order to improve impact resistance (Patent Application No. 2000-29610). .

On the other hand, the present inventors have come to develop a thermoplastic resin composition and a method for manufacturing the same, which have improved physical and chemical properties as well as chemical resistance among the physical properties of the copolymer having improved impact resistance.

An object of the present invention is to provide a thermoplastic resin composition excellent in chemical resistance by graft polymerization in three stages using three rubbery polymers having different rubber particle sizes and gel contents, respectively.

Another object of the present invention is to provide a thermoplastic resin composition excellent in impact strength and a method of manufacturing the same.

Still another object of the present invention is to provide a thermoplastic resin composition satisfying the above-described physical properties and a manufacturing method thereof.

The above and other objects of the invention can be achieved by the present invention described below.

Hereinafter, the content of the present invention will be described in detail.

The thermoplastic resin composition having improved chemical and impact resistance according to the present invention has a rubbery polymer latex and an aromatic vinyl-unsaturated nitrile-based graft monomer having a gel content of 75 to 95% by weight and an average particle diameter of 0.10 to 0.20 µm in one reactor. Graft copolymerization of the mixture to prepare a first graft copolymer; Secondary graft air by graft copolymerization of a rubbery polymer latex having an average particle diameter of 0.25 to 0.35 μm and an aromatic vinyl-unsaturated nitrile-based graft monomer mixture in the primary graft copolymer. A second step of preparing the coalescing; And tertiary graft by graft copolymerization of a mixture of rubbery polymer latex having an average particle diameter of 0.45 to 0.65 占 퐉 and an aromatic vinyl-unsaturated nitrile-based graft monomer in the secondary graft copolymer. It is prepared by the third step of preparing a copolymer.

As a result of the stepwise reaction as described above, a uniform graft reaction proceeds to rubbery polymers having different average particle diameters, and at the same time, a proper graft ratio can be maintained for each particle size. In addition, by using an acrylonitrile monomer having excellent chemical resistance as the graft monomer, a thermoplastic resin composition having excellent chemical resistance as well as balance of physical properties such as glossiness and impact resistance can be produced. It will be described below in detail.

Preparation of Graft Copolymer

(1) First step: preparation of the first graft copolymer (first graft reaction)

In the rubbery polymer latex of the present invention, three types of rubber latexes having an average particle diameter of 0.10 to 0.20 µm, 0.25 to 0.35 µm and 0.45 to 0.65 µm are used. In the first step, a small particle rubber latex having a small particle size is first present. A part of the total graft monomer mixture is added to graft to an appropriate conversion rate by an emulsion polymerization method to prepare a primary graft latex.

One or two or more monomer mixtures selected from aromatic vinyl monomers and unsaturated nitrile monomers which are graft monomers in the presence of 10 to 20 parts by weight of a butadiene-based rubbery polymer latex having a gel content of 75 to 95% by weight and an average particle diameter of 0.10 to 0.20 µm. 5-15 parts by weight of the emulsifier, polymerization initiator, molecular weight regulator, and ion-exchanged water are added and stirred, and the redox composition is added at 50-65 ° C., and the graph is first added in the range of 55-80 ° C. Most monomers are polymerized to produce a primary graft copolymer having a conversion rate of 80% or more, which is called a primary graft reaction.

(2) Second Step: Preparation of Secondary Graft Copolymer (Secondary Graft Reaction)

In the second step, a secondary graft latex is prepared by injecting a rubber latex having a particle diameter of 0.25 to 0.35 μm into the primary graft latex, and then adding a part of the graft monomer mixture to a suitable conversion rate. do.

In the presence of the primary graft copolymer, 10 to 25 parts by weight of butadiene-based rubbery polymer latex having a gel content of 65 to 85% by weight and an average particle diameter of 0.25 to 0.35 µm was added, and the remaining graft monomer mixture was 10 to 20 parts by weight. And a second graft monomer is polymerized by adding a molecular weight regulator and a polymerization initiator, and a second graft copolymer having a conversion rate of 90% or more is prepared. This is called a secondary graft reaction.

(3) Third Step: Preparation of Tertiary Graft Copolymer (Third Graft Reaction)

In the third step, the graft reaction is completed by injecting a rubbery latex having a large particle diameter of 0.45 to 0.65 μm into the secondary graft latex and adding a residual amount of the graft monomer continuously or separately.

In the presence of the secondary graft copolymer, 5 to 20 parts by weight of a butadiene-based rubbery polymer latex having a gel content of 50 to 70% by weight and an average particle diameter of 0.45 to 0.65 µm was added thereto, and the remaining graft monomer mixture, a molecular weight modifier, and polymerization were carried out. The remaining amount of the initiator is continuously or dividedly added over 2 to 5 hours, in which the reaction temperature is appropriately in the range of 55 to 80 ° C., and the tertiary graft air having a final polymerization conversion of 95 to 98% and a solid content of 38 to 44% by weight. Prepare coalescing.

By combining the reaction step by step as described above it is possible to maintain a uniform graft rate for each particle size at the same time the uniform graft reaction proceeds to the rubbery polymer having a different average particle diameter. In addition, by using an unsaturated nitrile monomer having excellent chemical resistance as a graft monomer, a thermoplastic resin composition having excellent chemical resistance as well as balance of physical properties such as glossiness and impact resistance can be prepared.

Rubbery polymer latex

The rubbery polymer that can be used in the one-step reaction for preparing the primary graft latex as the rubbery polymer latex that can be used in the present invention is a copolymer containing 80% by weight or more of polybutadiene.

Specific examples of the rubbery polymer latex may include aromatic vinyl compound copolymers such as butadiene-styrene, vinyl cyanide compound copolymers such as butadiene-acrylonitrile, and latexes such as butadiene-acrylic acid copolymers. In order to maintain the properties of the low polybutadiene rubbery polymer having a low glass transition temperature is preferred.

These gel contents vary depending on the size of the particle diameter, and the small particle size is preferably 75 to 95% by weight, the medium particle size is 65 to 85% by weight, and the large particle size is preferably in the range of 50 to 70% by weight. If the gel content is lower than the above range, the amount of polymerization is increased in the rubber particles, and the shape of the rubber is likely to change, which may increase the amount of coagulum generated during polymerization, and the glossiness of the final product is lowered. I can't. On the other hand, when it is higher than the above range, the efficiency of the rubber is lowered and the impact resistance is lowered.

The rubber latex used in the production of the primary graft copolymer used in the present invention preferably has a gel content of 75 to 95% by weight and an average particle diameter of 0.10 to 0.20 µm. When the gel content is less than 75% by weight, it is difficult to maintain an appropriate graft ratio during graft copolymerization. When the gel content is higher than 95% by weight, the gloss is improved, but the impact strength is lowered, which is not preferable.

In addition, the average particle diameter is a very important condition in the present invention, when the glossiness is improved, but the glossiness is improved, but it causes the deterioration of physical properties such as impact resistance and fluidity. I can't. As for the average particle diameter of the rubbery polymer latex used for manufacture of the said secondary graft copolymer, about 0.25-0.35 micrometer is preferable. When smaller than 0.25 micrometer, impact resistance falls, and when larger than 0.35 micrometer, it becomes a cause of the fall of glossiness. In addition, the average particle diameter of the rubbery polymer latex used in the preparation of the tertiary graft copolymer is preferably about 0.45 to 0.65 µm. When smaller than the above range, the impact resistance is lowered, and when larger, the reaction stability of the latex is lowered, the amount of coagulated matter is increased, and the gloss is lowered.

The amount of the total rubbery polymer latex used in the primary, secondary and tertiary graft copolymers is preferably 40 to 60 parts by weight (based on solids) based on 100 parts by weight of the total amount of the rubbery polymer latex and graft monomer used. . It is preferable to use 10-20 weight part of double-small-size rubbery polymer latex, 10-25 weight part of medium-size rubbery polymer latex, and 5-20 weight part of large-diameter rubbery polymer latex. If the total amount of the rubbery polymer is used less than the above range, the impact resistance of the resin is lowered, which is not preferable, and when a large amount is used, it is difficult not only to sufficiently increase the graft rate of the graft polymer but also to recover the fine powder during solidification and drying. The physical properties and appearance of the resin are lowered.

Graft Monomer Mixture

In the present invention, as the monomer to be graft copolymerized with the rubbery polymer latex, a mixture of an unsaturated nitrile monomer and a styrene monomer having excellent chemical resistance may be used. As said unsaturated nitrile monomer, an acrylonitrile monomer is preferable.

The graft monomer used in the present invention is a mixture of 55 to 70% by weight of styrene and 45 to 30% by weight of acrylonitrile, but preferably from 60 to 40 parts by weight based on 100 parts by weight of the total rubber polymer latex and graft monomer used. Do.

Of these, 5 to 15 parts by weight of the graft monomer mixture is preferable in the preparation of the primary graft copolymer in the presence of the small particle rubber latex, and 10 to 1 of the graft monomer mixture in the presence of the medium particle rubber latex in the preparation of the secondary graft copolymer. 20 parts by weight is continuously added, and in order to prepare a tertiary graft copolymer, it is preferable to copolymerize the entire remaining amount of the graft monomer mixture.

The step 1, 2 and 3 after the graft reaction may further comprise the step of adding and reacting the graft monomer, the addition amount of the added graft monomer is 75 to 35% by weight.

Among the graft monomers used in the 1, 2 and 3 graft reactions, the monomers used to prepare the first graft copolymer may partially polymerize rubber latex having a small particle diameter to partially polymerize inside the rubber particles. However, in most cases, the graft monomers are uniformly polymerized on the particle surface, thereby increasing the graft ratio to the rubber having a small particle diameter.

In addition, most of the graft monomer mixture which is injected simultaneously with the rubber having a large particle size of the tertiary reaction is polymerized by swelling the inside of the rubber having a large particle diameter, thereby forming a graft structure that is advantageous for impact strength, and is continuously injected. The monomer can obtain the desired physical properties by allowing the graft reaction to proceed uniformly around the rubber having a large and small particle diameter to maintain an equilibrium state between the inside and the outside of the rubber particles.

However, if the input ratio of the monomer mixture is out of the above range, the composition and amount balance of the monomer grafted inside and outside the rubber is not appropriate, which may damage the appearance of the resin surface, thereby obtaining the physical properties of the present invention. Difficult to do

The present invention will be further illustrated by the following examples, which are only specific examples of the present invention and are not intended to limit or limit the protection scope of the present invention.

Example

(a) Preparation of small particle rubbery polymer

100 parts by weight of 1,3-butadiene, 150 parts by weight of ion-exchanged water, 4.8 parts by weight of potassium rosinate, tertiary dodecylmer in a 10 L reactor equipped with a stirrer, a heating device, a cooling device, a condenser, and a monomer continuous input device by weight. 0.48 weight part of captans were put inside a reactor, stirring was performed for 40 minutes, maintaining reactor temperature at 45 degreeC, and the reactor temperature was heated up to 60 degreeC. When the reactor temperature reached 60 ℃ 0.30 parts by weight of potassium persulfate was added to initiate the reaction. When the reaction temperature was 70 ℃ after the start of the reaction was maintained at 70 ℃ using a cooling circulation device and the monomer was polymerized to cool the polymerization conversion is 95% or more to terminate the reaction to prepare a rubbery polymer latex. At this time, the gel content was 88% and the average particle diameter was 0.12 mu m.

(b) Preparation of Medium Grain Rubbery Polymer

Except for adding 140 parts by weight of ion-exchanged water, 3.5 parts by weight of potassium rosinate, and 0.35 parts by weight of terdodosilylcapcaptan in the first monomer mixture to be introduced, the same procedure as in the preparation of the small particle rubbery polymer was carried out. At this time, the gel content was 80% and the average particle diameter was 0.32 탆.

(c) Preparation of Large Size Rubbery Polymers

Except for the addition of 120 parts by weight of ion-exchanged water, 3.0 parts by weight of potassium rosinate, and 0.30 parts by weight of terdodosilylcapcaptan in the monomer mixture to be added first, the same method as for preparing the small-diameter rubbery polymer was prepared. At this time, the gel content was 60% and the average particle diameter was 0.52 μm.

(d) Preparation of Rubbery Polymers

Except that 0.70 parts by weight of tertiary dodecyl mercaptan in the first monomer mixture to be introduced was prepared in the same manner as the production method of the small particle size rubbery polymer. At this time, the gel content was 70% and the average particle diameter was 0.15 탆.

(e) Preparation of Rubbery Polymers

It was prepared in the same manner as in the above-described method for preparing a small particle rubbery polymer, except that 0.28 parts by weight of tercydodecyl mercaptan was added to the first monomer mixture. At this time, the gel content was 97% and the average particle diameter was 0.11 μm.

(f) Preparation of Rubbery Polymer

It was prepared in the same manner as in the above-described method for preparing a medium-sized rubbery polymer except that 0.70 parts by weight of tertiarydecyl mercaptan was added to the first monomer mixture. At this time, the gel content was 60% and the average particle diameter was 0.33 µm.

(g) Preparation of Rubbery Polymers

It was prepared in the same manner as in the above-described method for preparing a medium-sized rubbery polymer except that 0.10 parts by weight of tertiarydecyl mercaptan was added to the first monomer mixture. At this time, the gel content was 92% and the average particle diameter was 0.30 μm.

(h) Preparation of rubbery polymer

It was prepared in the same manner as in the above-mentioned method for preparing a large-diameter rubbery polymer except that 0.60 parts by weight of tertiarydecyl mercaptan was added in the first monomer mixture to be added. At this time, the gel content was 35% and the average particle diameter was 0.62 µm.

(i) Preparation of Rubbery Polymers

Except for 0.10 parts by weight of tertiary dodecyl mercaptan in the first monomer mixture was prepared in the same manner as in the manufacturing method of the large-diameter rubbery polymer. At this time, the gel content was 85% and the average particle diameter was 0.50 µm.

Example 1

15.0 parts by weight of the small particle rubbery polymer latex (a) prepared above, 3.5 parts by weight of acrylonitrile, 5.3 parts by weight of styrene, in a 10L reactor equipped with a stirrer, a heating device, a cooling device, a condenser, a continuous input device of monomers and a polymerization initiator. Part, 0.01 parts by weight of tertiary decyl mercaptan, 0.10 parts by weight of cumene hydroperoxide, 140 parts by weight of ion-exchanged water, 1.0 part by weight of potassium rosinate and 0.35 part by weight of dextrose in a reactor and then stirred at 60 ° C. After the temperature was raised, when the mixture temperature reached 60 ° C, 0.2 parts by weight of sodium parophosphate and 0.006 parts by weight of ferrous sulfate were added with additional stirring for 10 minutes to initiate the reaction. After the reaction was initiated, the reaction temperature was adjusted to 70 ° C. over 30 minutes, the reaction was continued for 10 minutes when reaching 70 ° C., and the reaction was terminated when the polymerization conversion rate reached 90% or more to prepare a first graft latex.

20.0 parts by weight of a medium particle size polybutadiene rubber latex (b) having an average particle diameter of 0.32 μm and a gel content of 80% by weight in the presence of the primary graft latex, 6.0 parts by weight of styrene, 4.1 parts by weight of acrylonitrile, While 0.2 parts by weight of tertiarydecyl mercaptan was added at a time, the temperature in the reactor was brought to 60 ° C., stirred for 20 minutes, and then 0.10 parts by weight of cumene hydroperoxide was added to carry out the second graft reaction.

10.0 parts by weight of a large particle size polybutadiene rubber latex (c) having an average particle diameter of 0.52 µm and a gel content of 60% by weight in the presence of the secondary graft latex, 6.2 parts by weight of styrene, 2.4 parts by weight of acrylonitrile, While tertiary dodecyl mercaptan 0.15 parts by weight was added at a time to make the temperature in the reactor to 60 ℃ and stirred for 20 minutes, 0.08 parts by weight of cumene hydroperoxide was added to the tertiary graft reaction. When the polymerization temperature reached 70 ℃, it was continued for 10 minutes, and then 16.8 parts by weight of styrene, 11.2 parts by weight of acrylonitrile, 0.13 parts by weight of terdodosilylcapcaptan were placed in a stirred container, stirred for 10 minutes, and continuously added for 3 hours. 0.25 parts by weight of cumene hydroperoxide was continuously added over 3 hours to proceed with the third graft reaction.

When the addition of monomer and polymerization initiator is completed, the reaction is continued for 40 minutes and then cooled. When the internal temperature of the reactor reaches 60 ° C, 0.30 parts by weight of 2,6-dibutyl 4-methylphenol is added as an antioxidant, followed by further stirring for 20 minutes. The reaction was terminated. At this time, the reaction temperature was gradually progressed to the graft reaction at 70 ℃, the total rubber polymer content was 45 parts by weight based on the solid content, the conversion rate after the end of the polymerization was 98%, the solid content of the latex obtained was 41.0%.

The graft copolymer latex was filtered through a 200 mesh wire mesh and the coagulum which failed to pass through the mesh was measured after drying at 100 ° C. for 6 hours to calculate a coagulum for solids, which was 0.15%. The latex passed through the mesh was coagulated with a 1% aqueous solution of sulfuric acid, dehydrated and dried to recover a white powder having a water content of 0.5% or less, followed by 35 parts by weight of powder, a weight average molecular weight of 118000, and an acrylonitrile content of 40 parts by weight. 65 parts by weight of the SAN resin was mixed with a stabilizer and a lubricant, and then extruded or injection molded to prepare a test piece for measuring physical properties.

Example 2

When preparing the first graft latex, 20.0 parts by weight of the small-size rubbery polymer (a) prepared above was used, and when preparing the second graft latex, 15.0 parts by weight of the medium-diameter rubber latex (b), and the third graft latex was substituted. It was prepared in the same manner as in Example 1 except that 10.0 parts by weight of the rubber latex (c) was used. The conversion rate after the completion of polymerization at this time was 96.5%, and the solid content of the obtained latex was 41.2%.

Example 3

In preparing the first graft latex, 6.6 parts by weight of styrene and 4.4 parts by weight of acrylonitrile are used, and in the preparation of the second graft latex, 3.3 parts by weight of styrene and 2.2 parts by weight of acrylonitrile are added together with the polybutadiene rubber latex and tertiary graft. The same procedure as in Example 1 was performed except that 23.1 parts by weight of styrene and 15.4 parts by weight of acrylonitrile were used together in the monomer mixture continuously injected with the large-diameter rubber latex when preparing the tratex. At this time, the conversion rate after the completion of the polymerization was 96.5% and the solid content of the obtained latex was 41.2%.

Comparative Example 1

In preparing the graft latex, 15.0 parts by weight of the small-size rubbery polymer latex (a), 20.0 parts by weight of the rubbery polymer latex (b) and 10.0 parts by weight of the rubbery polymer latex (c) were mixed and added in a batch, and total 55 weight of the copolymer monomer The weight of the styrene monomer was prepared in the same manner as in Example 1 except that the 70% by weight acrylonitrile monomer was applied in a mixing ratio of 30% by weight. At this time, the polymerization conversion rate after the completion of the polymerization was 98.5%, and the solid content of the obtained latex was 41.3%.

Comparative Example 2

The graft latex was prepared in the same manner as in Comparative Example 1 except that 45 parts by weight of the small-diameter rubbery polymer latex (a) prepared above was used to prepare the graft latex. At this time, the polymerization conversion rate after the completion of the polymerization was 98.2% and the solid content of the obtained latex was 40.8%.

Comparative Example 3

A graft latex was prepared in the same manner as in Comparative Example 1 except that 45 parts by weight of the medium-sized rubbery polymer latex prepared by the above (b) was used to prepare the graft latex. At this time, the polymerization conversion rate after the completion of the polymerization was 97.2% and the solid content of the obtained latex was 40.9%.

Comparative Example 4

The graft latex was prepared in the same manner as in Comparative Example 1, except that 45 parts by weight of the large-diameter rubbery polymer latex (c) prepared above was used to prepare the graft latex. At this time, the polymerization conversion rate after the completion of the polymerization was 96.2%, and the solid content of the obtained latex was 41.0%.

Comparative Example 5

When preparing the first graft latex, 20.0 parts by weight of the small particle size rubbery latex (a) prepared above was used. The same procedure as in Comparative Example 1 was conducted except that the graft polymer was prepared by the step reaction. At this time, the polymerization conversion rate after the completion of the polymerization was 98.2% and the solid content of the obtained latex was 40.8%.

Comparative Example 6

In the preparation of graft latex, 25.0 parts by weight of the medium-size rubbery latex (b) prepared above was used, and in the preparation of the second graft latex, two-step reaction was performed using 20.0 parts by weight of the large-diameter rubbery latex (c) prepared above. Except that the graft polymer was prepared in the same manner as in Comparative Example 1. At this time, the polymerization conversion rate after the completion of the polymerization was 97.5% and the solid content of the obtained latex was 40.9%.

Comparative Example 7

In preparing the first graft latex, 15.0 parts by weight of the rubbery latex (d) prepared above was used, and in the preparation of the second graft latex, 20.0 parts by weight of the rubbery latex (f) prepared above was used, and the third graft was used. The preparation was performed in the same manner as in Comparative Example 1 except that 10.0 parts by weight of the rubbery polymer latex (h) was used. At this time, the polymerization conversion rate after the completion of the polymerization was 97.5% and the solid content of the obtained latex was 40.9%.

Comparative Example 8

In preparing the first graft latex, 25.0 parts by weight of the rubbery polymer latex (d) prepared above was used, and in the preparation of the second graft latex, 20.0 parts by weight of the large-diameter rubbery polymer latex (c) prepared above was used. It was prepared in the same manner as in Comparative Example 1 except that the graft polymer was prepared. At this time, the polymerization conversion rate after the completion of the polymerization was 98.5% and the solid content of the obtained latex was 41.5%.

The latex was coagulated with a 1% aqueous sulfuric acid solution and recovered through a dehydration drying process to obtain a white powder having a water content of 0.5% or less, followed by 35 parts by weight of powder, 118,000 weight average molecular weight, and 40 parts by weight of acrylonitrile. The parts by weight were mixed with a stabilizer and a lubricant, followed by extrusion and injection molding to prepare specimens for physical property measurement. The physical properties of the obtained specimens were measured and the results are shown in Table 1.

Example Comparative example One 2 3 One 2 3 4 5 6 7 8 Graft Rate (wt%) 72 68 75 68 84 76 68 78 62 64 74 Coagulum (wt%) 0.08 0.11 0.12 0.24 0.10 0.19 0.51 0.25 0.43 0.37 0.17 Notched Izod Impact Strength (1/4 ") (kgcm / cm) 35.6 32.9 29.4 26.4 11.5 19.1 26.4 24.7 29.9 28.5 25.2 Glossiness 98 98 99 86 99 98 78 96 82 94 85 Flow index (g / 10min) 1.9 1.7 2.1 1.4 0.9 1.6 1.2 1.3 0.9 1.2 15 Specimen Surface State ○ ○ ○ △ △ ○ × × △ △ ○ Chemical resistance 0.5 0.75 0.4 0.3 0.4 0.3 0.2 0.2 0.3 0.4 0.3

1) Impact strength: Izod impact strength (1/4 "notch) was measured according to ASTM D256, 23 ℃.

2) Glossiness was measured according to ASTM D523.

3) Flow index was measured at 200 ℃, 5 kg load in accordance with ASTM D1238.

4) The surface state of the specimen was visually observed with a specimen of 1000 × 70 × 3 mm (○: good, △: normal, ×: poor).

5) Chemical resistance: 3 ml of solvent was weighed on a pipette and applied on a specimen with a thickness of 1.82 mm and a width of 12.79 mm for about 5 minutes, and then a semi-cylindrical jig (strain%) having a different radius of curvature for 1 hour. Was 0.2, 0.3, 0.4, 0.5, and 0.75, respectively, and measured by a coating method for evaluating chemical resistance depending on whether cracking occurred. At this time, the chemical used for chemical resistance evaluation is HCFC-141b, the larger the value indicates that the excellent chemical resistance.

The present invention uses three kinds of rubbery polymers having different rubber particle sizes and gel contents, respectively, and graft polymerization in an appropriate ratio with an unsaturated nitrile-styrene-based graft monomer mixture in three stages, whereby chemical resistance, glossiness and impact resistance are achieved. Has the effect of the invention to provide a significantly improved thermoplastic resin composition.

Simple modifications and variations of the present invention can be easily made by those skilled in the art, and all such modifications or changes can be seen to be included in the scope of the present invention.

Claims (4)

A graft copolymer is prepared by graft copolymerization of a rubbery polymer latex having an average particle diameter of 0.10 to 0.20 µm and an aromatic vinyl-unsaturated nitrile-based graft monomer mixture in a reactor to prepare a primary graft copolymer. Stage 1; Secondary graft air by graft copolymerization of a rubbery polymer latex having an average particle diameter of 0.25 to 0.35 μm and an aromatic vinyl-unsaturated nitrile-based graft monomer mixture in the primary graft copolymer. A second step of preparing the coalescing; And The third graft copolymer is made by graft copolymerization of a mixture of rubbery polymer latex having an average particle diameter of 0.45 to 0.65 µm and an aromatic vinyl-unsaturated nitrile-based graft monomer mixture in the secondary graft copolymer. Preparing a coalesce in a third step; Wherein the aromatic vinyl-unsaturated nitrile-based graft monomer mixture is made of 55 to 70% by weight of styrene and 45 to 30% by weight of acrylonitrile. The content of the rubbery polymer latex used in the first, second and third steps is 40 to 60 parts by weight based on 100 parts by weight of the total mixture of rubbery polymer latex and graft monomer used, wherein 10 to 20 parts by weight is used in the first step, 10 to 25 parts by weight is used in the second step, 5 to 20 parts by weight is used in the third step, and the content of the graft monomer is used in the entirety of the used rubbery polymer latex and graft monomer. 60 to 40 parts by weight based on 100 parts by weight, of which 5 to 15 parts by weight is used in the first step, 10 to 20 parts by weight is used in the second step, and the remaining monomers are used in the third step. Method for producing a thermoplastic resin composition. The method of claim 1, further comprising the step of reacting by further adding 35 to 75% by weight of the graft monomer after the third step. The method of claim 1, wherein the first step is added by stirring the butadiene-based rubbery polymer latex, graft monomer mixture, emulsifier, polymerization initiator, molecular weight control agent and ion-exchanged water by dividing, and then oxidized at 50 ~ 65 ℃ By adding a reducing agent composition, most of the graft monomers introduced in the range of 55 to 80 ° C. are mostly polymerized, and the conversion rate is 80% or more, and the second step is butadiene-based rubbery polymer latex and graft in the presence of the primary graft copolymer. The graft monomer is added to the secondary monomer mixture, the molecular weight modifier and the polymerization initiator, and most of the graft monomers are polymerized, so that the conversion rate is 90% or more, and the third step includes butadiene-based rubbery polymer latex in the presence of the secondary graft copolymer, Reaction temperature by continuously introducing the graft monomer mixture, the molecular weight regulator and the remainder of the polymerization initiator over 2 to 5 hours Figure 55 is a polymerization method in the range of 55 to 80 ℃, the final polymerization conversion is 95 to 98%, the solid content is 38 to 44% by weight of the production method of the thermoplastic resin composition.