KR20020038017A - Thermoplastic resin composition having advanced weatherproof property and impact strength and process for preparing the same - Google Patents

Abstract

PURPOSE: Provided is a thermoplastic resin composition having improved weather-resistance, impact-resistance, and gloss property, which is produced by using butadiene-acryl-based rubber polymers having different average particle sizes and properties. CONSTITUTION: The thermoplastic resin composition is produced by a process comprising the steps of: graft-copolymerizing a rubber polymer latex having the gel content of 60-80wt% and an average particle size of 0.10-0.15 micrometer and a graft monomer; graft-copolymerizing the first graft copolymer, a rubber polymer latex having the gel content of 50-70wt% and an average particle size of 0.25-0.30 micrometer and a graft monomer; graft-copolymerizing the second graft copolymer, a rubber polymer latex having the gel content of 40-50wt% and an average particle size of 0.50-0.65 micrometer and a graft monomer. The rubber polymer latex is a butadiene-acrylate copolymer, a butadiene-acrylate-styrene copolymer, or a butadiene-acrylate-acrylonitrile copolymer and the graft monomer is an aromatic vinyl monomer, an unsaturated nitrile monomer, or a mixture thereof.

Description

Thermoplastic resin composition having advanced weatherproof property and impact strength and process for preparing the same

Field of invention

The present invention relates to a thermoplastic resin composition excellent in weather resistance, and particularly excellent in impact resistance and glossiness, and a manufacturing method thereof. More specifically, the present invention relates to a thermoplastic resin composition having improved weather resistance, low temperature impact strength and glossiness by polymerizing three kinds of butadiene-acrylic rubber polymers having different average particle diameters and physical properties, in a stepwise manner and polymerizing them.

Background of the Invention

ABS resin obtained by graft copolymerization of styrene and acrylonitrile monomer on butadiene-based rubber polymer has excellent impact resistance and processability, and has excellent mechanical strength and heat deformation temperature, so it is widely used in electric, electronic products, automobile parts, and office equipment. . However, ABS resins contain chemically labile double bonds in the rubber components used, so the rubber components are easily aging by ultraviolet rays. In order to improve this problem, a method of adding a weather stabilizer during extrusion is used, but its effect is not large.

Meanwhile, various methods for improving the physical properties of ABS resins have been proposed. Patent Publication No. 91-15606 discloses a graft copolymer prepared using a rubbery polymer having a small particle diameter, but the glossiness of the prepared copolymer is improved, but the impact resistance is lowered. Patent Publication No. 90-11850 applies a method of improving the impact resistance to increase the rubber particle diameter or to reduce the gel content of the rubbery polymer, but it is difficult to control the properties of the graft copolymer as well as the impact resistance and glossiness. Balance of physical properties such as poor. 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. 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. In addition, in order to improve impact resistance and to improve the physical properties of the impact resistance and gloss by mixing acrylic rubber polymers having different average particle diameters, it is difficult to improve the satisfactory balance of physical properties.

Japanese Patent Laid-Open No. 59-202211 discloses a method of 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. Since the resin composition thus prepared has a surface area per volume of the small-size rubbery polymer larger 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. Insufficient compatibility between the large-diameter rubbery polymer and the matrix results in poor impact resistance.

Recently, various methods have been proposed to improve this problem. In particular, a method using chemically stable acrylic rubber instead of butadiene rubber and using a rubbery polymer mixed with butadiene and an acrylic polymerizable monomer is widely known. A resin obtained by graft copolymerization of styrene and acrylonitrile monomers to an acrylic rubber polymer (hereinafter referred to as "ASA resin") is used for interior and exterior parts such as automobiles and agricultural equipment with high exposure to sunlight, and for electrical and electronic products requiring special weather resistance. Widely used.

Since the ASA resin does not contain chemically labile double bonds, weather resistance is improved while impact resistance is reduced. As a method of improving the impact resistance, a method of increasing the rubber particle diameter or lowering the gel content of the rubbery polymer has been applied, but it is not only difficult to control the physical properties of the graft copolymer, but also deteriorate the balance of the impact resistance and gloss properties. have.

On the other hand, in the case of using a general polymerization method when mixing butadiene monomers and acrylic monomers, the formation of homopolymers between the acrylic monomers increases due to the difference in the reactivity ratio between the two components. Accordingly, the increase in the content of the acrylic monomer is limited, and the graft copolymer contains a large amount of rubber components that are not grafted, so that physical properties such as glossiness and impact resistance are significantly reduced.

The present inventors have applied for a patent application by developing a thermoplastic resin having excellent surface impact strength and excellent glossiness through even distribution and non-orientation using three kinds of rubbery polymers having different particle diameters (Patent Application 2000-29610). number).

Furthermore, the present inventors use a rubbery polymer containing an acrylic monomer to improve impact resistance and glossiness and greatly improve weather resistance, and also step by step at an appropriate ratio by varying the particle diameter of such butadiene-acrylic rubbery copolymer. It is early to develop the thermoplastic resin composition applied.

An object of the present invention is to provide a thermoplastic resin composition having excellent weather resistance and impact resistance by preparing a rubbery polymer by adding an acrylic monomer and a butadiene monomer in an appropriate ratio.

Another object of the present invention is to provide a thermoplastic resin composition having improved weather resistance, gloss and impact resistance by preparing a graft copolymer in which three rubber polymers having different rubber particle sizes are mixed.

Still another object of the present invention is to provide a thermoplastic resin composition capable of suppressing the generation of unplasticized particles on the resin surface generated by mixing by injecting rubbery polymers having different rubber particle sizes step by step.

Still another object of the present invention is to prepare a thermoplastic resin composition which can prevent a decrease in impact resistance and glossiness by preparing a rubbery polymer by continuously adding an acrylic monomer to a reactor in which a butadiene monomer is present.

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 weather resistance and impact resistance according to the present invention comprises the first graft copolymerization of a rubbery polymer latex having a gel content of 60 to 80% by weight and an average particle diameter of 0.10 to 0.15 µm in one reactor; Secondary reaction of the rubbery polymer latex having a gel content of 50 to 70 wt% and an average particle diameter of 0.25 to 0.30 mu m; And it is prepared by the third copolymerization of a rubbery polymer latex having a gel content of 40 to 50% by weight and an average particle diameter of 0.50 to 0.65 ㎛.

The important steps of the present invention are as follows: Three kinds of rubber latexes having an average particle diameter of 0.10 to 0.15 탆, 0.25 to 0.30 탆 and 0.50 to 0.65 탆 are used simultaneously, but the small particle size rubber is first small in the graft polymerization system. The first graft latex is prepared by presenting the latex and grafting a part of the entire graft monomer mixture to a suitable conversion rate by an emulsion polymerization method. In the presence of the primary graft latex, a rubber latex having a particle diameter of 0.25 to 0.30 µm is added thereto, and then a part of the graft monomer mixture is added to graf to a suitable conversion rate to prepare a secondary graft latex. Then, a rubbery latex having a large particle size of 0.50 to 0.65 µm is added thereto, and a third graft reaction is completed to complete the graft reaction by continuously or partially continuously adding the remaining amount of the graft monomer.

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. Therefore, a thermoplastic resin composition having excellent weather resistance and glossiness, greatly improving impact resistance, particularly low temperature impact strength, and having a proper balance of physical properties can be prepared.

Preparation of Rubbery Polymer Latex

As the rubbery polymer latex that can be used in the present invention, the rubbery polymer usable in the one-step reaction for preparing the first graft latex is a copolymer containing at least 60% by weight of butadiene monomer and at least 20% by weight of acrylate monomer. . Examples thereof include an aromatic vinyl compound copolymer such as butadiene-acrylate rubbery copolymer, butadiene-acrylate-styrene, or a vinyl cyanide compound copolymer such as butadiene-acrylate-acrylonitrile, preferably butadiene-acrylate rubbery air Coalescence is good.

Their gel content varies depending on the size of the particle size, preferably in the range of 60 to 80% by weight, 50 to 70% by weight and medium to 40 to 50% by weight of the small particle size. If the gel content is lower than the above range, the amount of polymerization in the rubber particles increases, so that the shape of the rubber is likely to change, which may increase the amount of coagulant generated during the polymerization, which is undesirable because the gloss in the final product is lowered. On the other hand, when the gel content is higher than the above range, the efficiency of the rubber is lowered and the impact resistance is lowered.

Preparation of Graft Copolymer

The production process of the graft copolymer in the presence of three rubbery polymer latexes satisfying the above properties is as follows:

(1) Preparation of Graft Copolymer-1 (Primary Graft Reaction)

One or two or more monomers selected from an aromatic vinyl monomer and an unsaturated nitrile monomer which are graft monomers in the presence of 10 to 45 parts by weight of a butadiene-acrylic rubbery polymer latex having a gel content of 60 to 80% by weight and an average particle diameter of 0.10 to 0.15 µm. 10-20 parts by weight of the mixture, an emulsifier, a polymerization initiator, a molecular weight regulator, and ion-exchanged water are added and stirred in a method of dividing, and then the redox composition is added at 50-65 ° C. to be first added in the range of 55-80 ° C. Most of the graft monomers are polymerized to prepare graft copolymer-1 having a conversion rate of 80% or more, which is called a first graft reaction.

(2) Preparation of Graft Copolymer-2 (Secondary Graft Reaction)

15 to 50 parts by weight of butadiene-acrylic rubber polymer latex having a gel content of 50 to 70% by weight and an average particle diameter of 0.25 to 0.30 μm in the presence of the graft copolymer-1, and a residual amount of the graft monomer mixture 10 to 25 Most of the graft monomers added to the secondary portion, the molecular weight regulator, and the polymerization initiator are polymerized to prepare graft copolymer-2 having a conversion rate of 90% or more, which is called a secondary graft reaction.

(3) Preparation of Graft Copolymer-3 (tertiary Graft Reaction)

In the presence of the graft copolymer-2, 5 to 35 parts by weight of a butadiene-acrylic rubber polymer latex having a gel content of 40 to 50% by weight and an average particle diameter of 0.50 to 0.65 μm, and a residual amount of the graft monomer mixture 5 to 20% The remaining portion of the portion, the molecular weight regulator and the polymerization initiator are continuously added over 2 to 5 hours. At this time, the reaction temperature is appropriately in the range of 55 to 80 ℃, the final polymerization conversion is 95 to 98%, the solid content is prepared 38 to 44% by weight graft copolymer-3.

The graft copolymer latex coagulated with isopropyl alcohol is dehydrated and dried to obtain a white powder. The graft copolymer latex is dissolved in acetone and centrifuged. The graft ratio is measured after washing, drying and basis weight. The calculation is as follows:

In order to meet the object of the present invention, the graft ratio of the graft copolymer should be 55 to 70%. When the graft ratio of the graft copolymer is lower than this, coagulation occurs, and it is difficult to obtain a white powder having a uniform particle size distribution during drying. Particularly, during extrusion and injection, pinholes and sand surfaces appear as unplasticized particles on the surface of the molded article. Lowers the commodity value of the final molding. In addition, when it is higher than the above range, the interfacial adhesive force is reduced during the mixing process with the matrix SAN resin (styrene-acrylonitrile copolymer resin), and the physical properties of impact strength, fluidity, and surface gloss are lowered.

The rubber latex used in the preparation of the graft copolymer-1 used in the present invention preferably has a gel content of 60 to 80% by weight, and an average particle diameter of 0.10 to 0.15 µm. When the gel content is less than the above range, it is difficult to maintain an appropriate graft ratio during graft copolymerization, and in particular, the graft monomers swell into the rubber particles, thereby lowering the polymerization stability, thereby forming a large amount of coagulant during polymerization, thereby decreasing gloss. It causes. On the other hand, if it is higher than the above range, the gloss is improved, but it is not preferable to lower the impact strength. In addition, the average particle diameter is a very important condition in the present invention, if the glossiness is improved but less than the above range is the cause of deterioration of physical properties such as impact resistance and fluidity, if larger than the above range is not preferable because the gloss is lowered.

As for the average particle diameter of the rubbery polymer latex used for manufacture of the said graft copolymer-2, about 0.25-0.30 micrometer is preferable. When smaller than the said range, impact resistance falls, and when large, it becomes a cause of fall of glossiness.

In addition, the average particle diameter of the rubbery polymer latex used in the preparation of the graft copolymer-3 is preferably about 0.50 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 preparation of the graft copolymer-1, 2 and 3 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. . The small particle size rubbery latex is 10 to 45% by weight, the medium sized rubbery polymer latex is 15 to 50% by weight, and the large particle size rubbery latex is 5 to 35% by weight (based on 100 parts by weight of the total rubbery polymer latex). desirable. If the total amount of the rubbery polymer is used in less than the above range, the impact resistance of the resin is lowered and the productivity is not preferable, and when a large amount is used, it is not only difficult to sufficiently increase the graft rate of the graft polymer, but also fine powder during solidification and drying. It is difficult to recover the resin, resulting in deterioration of the physical properties and appearance of the resin.

The graft monomer used in the present invention is a mixture of 65 to 80% by weight of styrene, 35 to 20% by weight of acrylonitrile, but preferably 60 to 40 parts by weight based on 100 parts by weight of the entirety of the rubbery polymer latex and graft monomer used. In particular, 10 to 20% by weight of the graft monomer mixture in the presence of the small particle rubber latex is preferable, and graft monomer in the preparation of the graft copolymer-2 in the presence of the medium particle rubber latex. 10 to 25% by weight of the mixture is continuously added, and it is preferable to copolymerize 5 to 20% by weight of the monomer mixture to prepare graft copolymer-3.

It is preferable to polymerize the remaining 75 to 35% by weight of the graft monomer after the 1, 2 and 3 step graft reaction. Among the graft monomers used in the 1, 2 and 3 graft reactions, the monomers used to prepare the graft copolymer-1 may be partially polymerized inside the rubber particles by dispersing some of the rubber latex having a small particle diameter therein. 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 size as much as possible. Swells the rubber inside to form a graft structure that is advantageous for impact strength, while the graft monomers that are added continuously are uniformly grafted around the rubber with large and small particle diameters, allowing the graft reaction to proceed inside and outside the rubber particles. By maintaining equilibrium with parts, the desired physical properties The can. 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 In addition, the reaction temperature should be controlled during the graft polymerization. If the polymerization temperature is lower than the above range during the 1, 2 and 3 step graft reaction, the polymerization rate will be slowed down, and the productivity will decrease. There is a problem that coagulum tends to occur during polymerization.

In addition, the type, amount and addition rate of the emulsifier, the molecular weight regulator and the polymerization initiator are also very important. That is, in the method of adding the molecular weight regulator and the polymerization initiator used in the three-step graft reaction, the continuous dosing method induces the graft reaction uniformly and uniforms the molecular weight and molecular weight distribution, and the dosing time is consumed by the graft polymerization. By optimizing the reaction rate of the monomer it is possible to suppress the formation of coagulum during the polymerization. More specifically described as follows.

As the emulsifier usable in the present invention, those used in a conventional emulsion polymerization method may be used, and examples thereof include fatty acid metals such as potassium stearate, sodium oleate, sodium laurate, potassium oleate, and the like; Alkali metasulfonates of allyl sulfonic acid such as sodium naphthalene sulfonate, sodium isopropyl naphthalene sulfonate and the like; And potassium rosinate. Among them, one or two or more mixed emulsifiers selected from potassium oleate, potassium stearate and potassium rosinate are preferable. The amount of these used is preferably 0.1 to 2.0 parts by weight, and when used in a smaller amount than the above range, a large amount of coagulum is generated in latex, which is not preferable. When used in excess, grafting is caused by excessive generation of grafted SAN (styrene-acrylonitrile copolymer). Difficulty in controlling physical properties such as graft ratio of the polymer may also cause glossiness deterioration in the appearance of the molded article during injection molding.

As the molecular weight modifier usable in the present invention, mercaptans having 8 to 18 carbon atoms, terpinolene, alpha methyl duplex, and the like are preferred, and tertiary dodecyl mercaptan is preferable. These amounts are preferably 0 to 0.15 parts by weight for the first graft reaction, 0.05 to 0.15 parts by weight for the molecular weight regulators added at a time during the second graft reaction, and for the molecular weight regulators to be added at the time during the third graft reaction. 0.05-0.20 weight part is good, and 0.05-0.15 weight part is preferable in the case of a continuous molecular weight modifier.

As the polymerization initiator, a polymerization initiator used in a conventional emulsion polymerization method may be used, and examples thereof include a fat-soluble initiator such as cumene hydroperoxide and benzoyl peroxide, and a water-soluble initiator such as ammonium persulfate and potassium persulfate. Preferably cumene hydroperoxide is preferable. These amounts are preferably 0.03 to 0.15 parts by weight in the first graft reaction, 0.05 to 0.10 parts by weight for the polymerization initiator added at a time during the second graft reaction, and 0.1 to 0.35 parts by weight for the polymerization initiator continuously added. The molecular weight modifier and polymerization initiator used in the tertiary graft reaction are continuously added over 2 to 4 hours together with the graft monomer mixture continuously added to induce uniform graft polymerization and molecular weight and molecular weight distribution. desirable.

The redox catalyst that can be used in the present invention may be a redox agent that is used for the conventional hydroperoxide-based redox emulsion polymerization, and examples thereof include metal salts such as ferrous sulfate, sodium parophosphate, ethylenediaminetetraacetic acid, and textulos. And redox catalysts. These amounts of use are preferably 0.001 to 0.35 parts by weight with respect to each redox agent.

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. All parts and percentages described herein are by weight unless otherwise indicated.

Example

Example 1

70 parts of 1,3-butadiene, 5 parts of butyl acrylate, 150 parts of ion-exchanged water, 4.5 parts of potassium rosinate, tertiary 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. 0.50 part of dodecyl mercaptan was placed in the reactor, stirred for 40 minutes while maintaining the reactor temperature at 45 ° C, and the reactor temperature was raised to 60 ° C. When the reactor temperature reached 60 ℃ 0.30 parts by weight of potassium persulfate was added to initiate the reaction. When the reaction temperature reached 70 ℃ after the start of the reaction, 25 parts by weight of butyl acrylate was continuously added for 10 hours while maintaining the temperature of 70 ℃ using a cooling circulation device, and the monomer was polymerized to cool down when the polymerization conversion rate was 95% or more. To prepare a rubbery polymer latex. At this time, the gel content of 75%, the average particle diameter is 0.15 ㎛.

Example 2

The same procedure as in Example 1 was carried out except that 140 parts of ion-exchanged water, 3.5 parts of potassium rosinate, and 0.40 parts of tertiary dodecyl mercaptan were added to the first monomer mixture. At this time, the gel content is 68%, the average particle diameter is 0.30㎛.

Example 3

The same procedure as in Example 1 was carried out except that 120 parts of ion-exchanged water, 3.0 parts of potassium rosinate, and 0.30 part of tertiary dodecyl mercaptan were added to the first monomer mixture. At this time, the gel content is 55%, the average particle diameter is 0.62㎛.

Comparative Example 1-2

The same procedure as in Example 1 was carried out except that 1,3-butadiene was 100 parts in the monomer to be introduced first. At this time, the gel content is 85%, the average particle diameter is 0.12㎛.

Comparative Example 2

The same procedure as in Example 1 was repeated except that 100 parts of butyl acrylate was added to the first monomer. At this time, the gel content is 75%, the average particle diameter is 0.11㎛.

Comparative Example 3

It carried out similarly to Example 2 except using 100 parts of 1, 3- butadiene among the monomers put in primary. At this time, the gel content is 72%, the average particle diameter is 0.33㎛.

Comparative Example 4

The same procedure as in Example 2 was carried out except that 100 parts of butyl acrylate were used as the first monomer. At this time, the gel content is 70%, the average particle diameter is 0.30㎛.

Comparative Example 5

It carried out similarly to Example 3 except using 100 parts of 1, 3- butadiene among the monomers put in primary. At this time, the gel content is 55%, the average particle diameter is 0.58㎛.

Comparative Example 6

The same procedure as in Example 3 was carried out except that 100 parts of butyl acrylate were used as the first monomer. At this time, the gel content is 52%, the average particle diameter is 0.57㎛.

Example 4

15.0 parts of small particle rubbery polymer latex prepared in Example 1, 2.3 parts of acrylonitrile, 6.5 parts 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 0.01 part of dodecyl mercaptan, 0.10 part of cumene hydroperoxide, 140 parts of ion-exchanged water, 1.0 part of potassium rosinate, and 0.35 part of dextrose were added to the reactor, and the temperature was raised to 60 ° C while stirring. When the mixture temperature reached 60 ° C, 0.2 parts of sodium parophosphate and 0.006 parts of ferrous sulfate were added while stirring for 10 minutes to start 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 of butadiene-acrylic rubber latex having an average particle diameter of 0.30 μm and a gel content of 68% by weight in the presence of the primary graft latex, 7.0 parts of styrene, 3.1 parts of acrylonitrile, tertiary dodecyl While 0.2 part of mercaptan was added at a time, the temperature in the reactor was brought to 60 ° C, stirred for 20 minutes, and 0.10 part of cumene hydroperoxide was added to carry out a second graft reaction. 10.0 parts of butadiene-acrylic rubber latex having an average particle diameter of 0.62 μm and a gel content of 55% by weight in the presence of the secondary graft latex, 6.2 parts of styrene, 2.4 parts of acrylonitrile, tertiary dodecyl While 0.15 part of mercaptan was thrown in at one time, the temperature in a reactor was set to 60 degreeC. After stirring for 20 minutes, 0.08 parts of cumene hydroperoxide was added thereto, followed by tertiary graft reaction. When the polymerization temperature reached 70 ° C., the mixture was continued for 10 minutes, followed by stirring of 20.1 parts of styrene, 7.9 parts of acrylonitrile, and 0.13 parts of tertiary dodecyl mercaptan. The mixture was stirred in a container for 10 minutes, and then continuously added for 3 hours, and 0.25 parts of cumene hydroperoxide was continuously added for 3 hours to proceed with the tertiary graft reaction. When the monomer and polymerization initiator are added, the reaction is continued for 40 minutes and then cooled. When the temperature inside the reactor reaches 60 ° C, 0.30 part of 2,6-dibutyl 4-methylphenol is added as an antioxidant, followed by further stirring for 20 minutes. At this time, the reaction temperature was gradually progressed to the graft reaction at 70 ℃, the total rubber polymer content was 45.0 parts by solid content, the conversion rate after the end of the polymerization was 98%, the solid content of the latex obtained was 40.8%.

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 solidified with 1% sulfuric acid aqueous solution, dehydrated and dried to recover white powder with a water content of 0.5% or less, and then 35.0 parts of powder and 65.0 parts of SAN resin having a weight average molecular weight of 125000 were mixed with a stabilizer and a lubricant. Next, extrusion injection molding was carried out to prepare a test piece for measuring the physical properties.

Comparative Example 7

In preparing the first graft latex, 15.0 parts of the rubbery polymer latex prepared in Comparative Example 1 was used, and in the preparation of the second graft latex, 20.0 parts of the rubbery polymer latex prepared in Comparative Example 3 were used. The same procedure as in Example 4 was repeated except that 10.0 parts of the rubbery polymer latex prepared in Comparative Example 5 was used. At this time, the polymerization conversion rate after the completion of the polymerization was 96.8%, and the solid content of the obtained latex was 40.8%.

Comparative Example 8

In preparing the first graft latex, 15.0 parts of the rubbery polymer latex prepared in Comparative Example 2 was used, and in the preparation of the second graft latex, 20.0 parts of the rubbery polymer latex prepared in Comparative Example 4 were used. It carried out in the same manner as in Example 4 except that 10.0 parts of the rubbery polymer latex prepared in Comparative Example 6 was used. At this time, the polymerization conversion rate after completion of the polymerization was 98.2%, and the solid content of the obtained latex was 41.3%.

Comparative Example 9

20.0 parts of the rubbery polymer latex prepared in Example 1 was used to prepare the first graft latex, and 25.0 parts of the rubbery polymer latex prepared in Example 2 was prepared to prepare the graft latex. It carried out similarly to Example 4 except having performed one. At this time, the polymerization conversion rate after completion of the polymerization was 98.8%, and the solid content of the obtained latex was 41.8%.

Comparative Example 10

25.0 parts of the rubbery polymer latex prepared in Example 2 was used to prepare the first graft latex, and 20.0 parts of the rubbery polymer latex prepared in Example 3 was prepared to prepare the graft latex. It carried out similarly to Example 4 except having performed one. 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 40.5%.

Comparative Example 11

25.0 parts of the rubbery polymer latex prepared in Example 1 was used to prepare the first graft latex, and 20.0 parts of the rubbery polymer latex prepared in Example 3 was prepared to prepare the graft latex. It carried out similarly to Example 4 except having performed one. 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 12

The graft latex was prepared in the same manner as in Example 4 except that 45 parts of the rubbery polymer latex prepared in Example 1 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 13

The graft latex was prepared in the same manner as in Example 4, except that 45 parts of the rubbery polymer latex prepared in Example 2 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 14

The graft latex was prepared in the same manner as in Example 4 except that 45 parts of the rubbery polymer latex prepared in Example 3 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%.

Example 5

30.0 parts of the rubber polymer prepared in Example 1 was prepared in preparing the first graft latex, and 15.0 parts of the rubber latex prepared in Example 2 was prepared in the preparation of the second graft latex. The same procedure as in Example 4 was conducted except that 10.0 parts of rubber latex was used. At this time, the conversion rate after the completion of the polymerization was 97.3%, and the solid content of the obtained latex was 40.8%.

Example 6

7.7 parts of styrene and 3.3 parts of acrylonitrile are used to prepare the first graft latex, 3.85 parts of styrene and 1.65 parts of acrylonitrile are added together with the rubber latex to prepare the second graft latex, and to prepare the third graft latex. The same procedure as in Example 4 was carried out except that 26.95 parts of styrene and 11.55 parts of acrylonitrile were used in the monomer mixture continuously added to the large-diameter rubber latex. At this time, the conversion rate after the completion of the polymerization was 97.3%, and the solid content of the obtained latex was 40.8%.

Example 7

9.7 parts of styrene and 4.3 parts of acrylonitrile are used to prepare the first graft latex, 3.85 parts of styrene and 1.65 parts of acrylonitrile are added together with the rubber latex to prepare the second graft latex, and to prepare the third graft latex. The same procedure as in Example 4 was carried out except that 24.95 parts of styrene and 10.55 parts of acrylonitrile were used together in the monomer mixture continuously added to the large-diameter rubber latex. At this time, the conversion rate after the completion of the polymerization was 97.1%, and the solid content of the obtained latex was 39.8%.

The physical properties of the resin composition prepared in Example 4-7 and Comparative Example 7-14 were measured, and the results are shown in Table 1. The prepared specimens were measured for Izod impact strength (1/4 "notch) and Izod impact strength (1/4" notch) after 600 hours of irradiation in accordance with ASTM D256 at 23 ° C and low temperature impact strength at -10 ° C. It was. Weatherability was observed using XENO TEST 150S from Germany HERAEUS. Glossiness was measured according to ASTM D523. Flow index was measured at 200 ℃, 5 kg load in accordance with ASTM D1238. . . . . The surface state was observed by visually observing a specimen of 300 × 70 × 3 mm (○: good, Δ: normal, ×: poor).

Example Comparative Example 4 5 6 7 7 8 9 10 11 12 13 14 Graft Rate (w%) 56 58 65 62 68 72 78 54 65 82 65 48 Coagulum (w%) 0.16 0.18 0.18 0.22 0.20 0.53 0.23 0.56 0.65 0.48 0.23 1.56 Impact strength kgfcm / cm 26.4 22.9 25.1 24.2 27.1 19.1 12.4 24.3 21.9 10.4 18.1 23.4 Impact strength after 600 hours of irradiation kgfcm / cm 25.5 21.6 24.5 24.5 22.1 18.9 12.5 23.4 20.7 10.1 17.8 20.7 Low temperature impact strength kgf · cm / cm, -10 ℃ 25.5 21.6 24.5 24.5 22.1 18.9 12.5 23.4 20.7 10.1 17.8 20.7 Glossiness ASTM D523 98 99 96 99 83 89 99 86 92 99 95 78 Flow index ASTM D1238g / 10min, 5Kg, 200 ℃ 2.1 1.8 2.0 1.7 0.9 1.5 1.2 1.0 1.2 0.8 1.8 0.9 Specimen Surface State ○ ○ ○ ○ △ ○ × × △ △ ○ ×

The present invention provides three types of butadiene-acrylic rubbery polymers having different rubber particle sizes and properties, and is mixed with acrylic monomers in an appropriate ratio stepwise to prepare a graft copolymer, thereby simultaneously producing unplasticized particles on the resin surface. The invention has the effect of providing a thermoplastic resin composition which can suppress the occurrence of these and improve weather resistance, gloss and especially impact resistance.

Simple modifications or changes of the present invention can be easily carried out 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 (6)

(1) primary graft copolymerization of a rubbery polymer latex having a gel content of 60 to 80% by weight and an average particle diameter of 0.10 to 0.15 mu m and a graft monomer in the reactor; (2) secondary graft copolymerization of the rubber polymer latex and graft monomer having a gel content of 50 to 70% by weight and an average particle diameter of 0.25 to 0.30 µm in the primary graft copolymer; And (3) tertiary graft copolymerization of the graft monomer with the rubbery polymer latex having a gel content of 40 to 50% by weight and an average particle diameter of 0.50 to 0.65 mu m in the secondary graft copolymer; A method for producing a thermoplastic resin composition having improved weather resistance and impact resistance, characterized by being prepared by the step. The method of claim 1, wherein the rubbery polymer latex is butadiene-acrylate copolymer, butadiene-acrylate-styrene copolymer or butadiene-acrylate-acrylonitrile copolymer, the graft monomer is an aromatic vinyl monomer, unsaturated nitrile A method for producing a thermoplastic resin composition, characterized in that the monomer or a mixture thereof. According to claim 1, wherein the content of the rubbery polymer used in the steps (1), (2) and (3) is 40 to 60 parts by weight based on 100 parts by weight of the total of the rubbery polymer latex and graft monomer used, Of these, 10 to 45% by weight is used in step (1), 15 to 50% by weight is used in step (2), 5 to 35% by weight is used in step (3), and the content of the graft monomer is used. 60 to 40 parts by weight, based on 100 parts by weight of the total rubber polymer latex and graft monomers, of which 10 to 20 parts by weight are used in step (1), 10 to 25 parts by weight in step (2), and (3) In the step 5 to 20 parts by weight of the thermoplastic resin composition, characterized in that used. The method according to claim 1, further comprising the step (4) of further adding and reacting the graft monomer after the step (3), wherein 60 to 40 parts by weight of the graft monomer to be used is 10 to 10 in step (1). 20 weight%, 10-25 weight% in (2), 5-20 weight% in (3), 75-35 weight% in (4), The manufacturing method of the thermoplastic resin composition characterized by the above-mentioned. The method of claim 1, wherein the step (1) is carried out by adding and adding an emulsifier, a polymerization initiator, a molecular weight modifier, and ion-exchanged water, and then adding a redox composition at 50 to 65 ° C to 55 to 80 ° C. Most of the first graft monomer is polymerized in the polymerization, the conversion is more than 80%, the step (2) is the conversion of the graft monomer is mostly polymerized by the addition of the molecular weight regulator and the polymerization initiator is more than 90% conversion. In step (3), the remainder of the molecular weight modifier and the polymerization initiator is continuously added over 2 to 5 hours, and the reaction temperature is appropriately in the range of 55 to 80 ° C., and the final polymerization conversion is 95 to 98% and the solid content is 38 to 44. A method for producing a thermoplastic resin composition, characterized in that to prepare a graft copolymer in weight%. A thermoplastic resin composition prepared by the method of any one of claims 1 to 5.