JPS6026425B2 - thermoplastic resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention involves grafting a monomer mixture such as a vinyl aromatic monomer and a vinyl cyan monomer onto a rubbery polymer latex each having a specific different particle size distribution and degree of swelling. The present invention relates to a thermoplastic resin composition obtained by mixing two types of graft copolymers obtained by polymerization in a specific ratio.

More specifically, a monomer mixture such as a vinyl aromatic monomer and a vinyl cyan monomer is graft-polymerized to a rubbery polymer latex each having a specific different particle distribution and degree of swelling. By mixing two types of graft copolymers with a specific graft ratio within a specific range, the impact resistance (orientation) at room temperature and low temperature during thin wall molding, thermal stability during high temperature molding, and coating properties can be improved. The present invention provides a thermoplastic resin composition that has extremely good impact resistance retention at room temperature and low temperature. A mixture of a vinyl aromatic monomer such as styrene and a vinyl cyan monomer such as acrylonitrile in a rubbery polymer latex, or a mixture of these and a (meth)acrylic acid ester monomer such as methyl (meth)acrylate. It is known that a thermoplastic resin can be produced by graft copolymerizing the following in the presence of a radical polymerization initiator.

Resin manufactured by this method has excellent impact resistance, is easy to mold, and has many other excellent properties as a thermoplastic resin, and is used as a so-called ABS resin for housings of various electrical products. It is widely used in fields such as interior and exterior parts of automobiles and various miscellaneous goods.

However, in recent years, in the thermoplastic resin molding industry, there has been a strong demand for rationalization such as saving resources and reducing production costs. As a result, the molding temperature has increased to the limit, the residence time during molding has increased, the molding speed has increased, and secondary processing conditions such as painting have become increasingly strict. It is in. Therefore, in addition to the impact resistance and processability of the resin, it also improves thermal stability at high temperatures and molding residence time, improves impact resistance during thin-wall molding, and improves impact resistance after painting. It is also required to improve impact resistance under a wide range of environmental conditions (particularly in low-temperature environments). In determining the performance of ABS resin, the characteristics of the rubber polymer latex and the graft state when monomers are graft copolymerized to the rubber polymer latex are important factors. Many methods have already been proposed to improve the performance of resins.

For example, in Japanese Patent Publication No. 39-3991, the average particle diameter is 0.
．． A method is described in which a monomer polymer consisting of styrene in an amount of 5% by weight or more is graft-polymerized onto a rubbery polymer latex having two or more ridges and a gel content of 75% or more.

Furthermore, in Hakama Kosho No. 47-13779, one is a rubbery polymer latex with a gel content of 70% or more and a swelling degree of 30 or less, and the other is a rubbery polymer latex with a gel content of 50% or less and a swelling degree of 30 or less. By mixing with a rubbery polymer latex with a low gel content of 90 degrees or more, the gel content is 45 to 75%.
It is described that a rubbery polymer latex having a swelling degree of 25 to 90 is used. Furthermore, Hakama Kosho 46-12
No. 1943 describes a first graft copolymer using rubber with an average particle size of 0.8 to 2.0 and a first graft copolymer using a rubber with an average particle size of 0.01 to 2.0.
A multi-mix composition obtained by mixing a second graft copolymer using a 0.25 mt. The issue includes a highly cross-linked first graft copolymer, a relatively low-cross-linked second graft copolymer, and an English polymer consisting of a monovinylidene aromatic hydrocarbon and an unsaturated nitrile. Polyblends with matrices are described. The performance of thermoplastic resins obtained by these methods, especially impact resistance, etc., is improved to a level sufficient for normal uses.

However, in recent years, the performance of this type of thermoplastic resin has been required to meet high temperatures, thermal stability during mold retention, impact resistance during thin-wall molding, impact resistance after painting, and even under a wide range of environmental conditions (especially in low-temperature environments). When considering the impact resistance in (lower), it is difficult to say that these methods are fully satisfactory. The present inventors took into account the above points,
In addition to good impact resistance and molding processability, it has good thermal stability during high temperature residence (slight loss of gloss), impact resistance during thin wall molding, impact resistance after painting, and in a wide range of environments. As a result of intensive studies to improve the impact resistance under various conditions, we determined not only the particle size distribution and swelling concentration of the rubbery polymer latex used, but also the graft copolymerization form of the resinous component to the rubbery polymer latex. As a result of intensive studies based on this knowledge, the present invention has been arrived at.

That is, in the present invention, 70% or more of the harmful particles have a particle size of 150
0 to 4000A and a swelling degree of 30 or less, at least one vinyl aromatic monomer, at least one vinyl cyan monomer, and optionally (meth) At least one acrylic acid ester simple substance
A graft copolymer with a graft ratio of 40% or more obtained by graft polymerization of a monomeric polymer containing seeds, and 50% of [B' particles]
The above particles exist in the range of particle size 4000 to 25000A,
and a rubbery polymer latex having a swelling degree of 70 or more, at least one vinyl aromatic monomer, at least one vinyl cyan monomer, and optionally a (meth)acrylic acid ester monomer. It consists of a mixture of a single enrichment polymer containing at least one species and a graft copolymer having a graft ratio of 40% or more, and the weight ratio of the graft copolymer and the [B-graft copolymer] is 40: 60-90:10
The present invention relates to a thermoplastic resin composition within the range of . Next, the constituent elements of the present invention will be explained in detail.

What is particularly important in the present invention is that the graft polymers for the graft polymer and the graft polymer for the leg are synthesized separately, and the two are mixed in a specific ratio. In the graft polymer used in the present invention, when the particle size distribution of the rubbery polymer used is out of the range of the present invention, that is, 1500 to 40
If the weight fraction within the range of 0.00% is 70%, the impact resistance and the impact resistance after coating will decrease.

Furthermore, if the swelling degree of the rubbery polymer exceeds 30, the Rockwell hardness will decrease and the gloss during high temperature molding will be insufficient.

If the graft ratio is less than 40%, the gloss during high temperature molding and the impact resistance during thin molding (particularly low temperature compounding Wizotte impact strength) will decrease.

The grafting rate is preferably 50% or more. In the graft polymer curve used in the present invention, if the particle size distribution of the rubbery polymer used is outside the scope of the present invention, that is, 4
If the weight fraction within the range of 000 to 25000A is less than 50%, the impact resistance at room temperature and low temperature and the low temperature impact resistance after coating will decrease.

It is particularly preferable to use a rubbery polymer latex having an average particle size of 5000 to 8000A. When the Sanzono degree is 7 degrees, the effect of improving the impact resistance at room temperature and low temperature and the low temperature impact resistance after painting is insufficient.

Furthermore, if the grafting ratio is less than 40%, the gloss during high temperature molding and the low temperature orientation Izod impact strength will decrease.

Regarding the mixing ratio of the graft polymer Kaze and Tsukuda, the weight ratio of the Kaze graft polymer in the whole graft polymer is 40 to 40.
A range of 90% is preferable; if it is less than 40%, the gloss during high-temperature molding will be significantly reduced, and if it exceeds 90%, the impact resistance at room temperature and low temperature and the low-temperature impact resistance after painting will deteriorate. becomes insufficient. Examples of the rubbery polymer latex used in the present invention include polyptadiene and a latex containing butadiene containing 50% or more of butadiene and other copolymerizable monomers. Monomers that can be polymerized with ptadiene include styrene, Q-methylstyrene,
Examples include vinyl aromatic monomers such as vinyltoluene, pinylcyan monomers such as acrylonitrile and methacrylonitrile, and acrylic monobases such as methyl, ethyl, and propyl ester of acrylic acid and methacrylic acid.

When considering impact resistance at low temperatures, Ptadiene is
A butadiene copolymer containing 0% or more is preferred. 0 Vinyl aromatic monomers that can be used for graft polymerization in the present invention include styrene, alkyl-substituted styrenes such as Q-methylstyrene, vinyltoluene, and dimethylstyrene;
Nuclear halogen-substituted styrenes such as chlorstyrene, bromstyrene, dichlorostyrene, and dibromstyrene can be mentioned.

As the vinyl cyanide monomer, acrylonitrile, methacrylonitrile, etacrylonitrile, etc. can be used.

Furthermore, alkyl esters of acrylic acid and methacrylic acid, such as methyl, ethyl, propyl, butyl, can be used if necessary.

The monomer mixture used for graft polymerization includes 5% by weight or more of vinyl aromatic monomer and 1% by weight of vinyl cyan monomer.
It is preferable that the content is greater than or equal to .

Particularly preferred ranges are 40 to 9% by weight of styrene and 60 to 1% by weight of acrylonitrile. In the present invention, when a monomer is added to the rubbery polymer latex and a graft reaction is carried out by emulsion polymerization in the presence of a radical polymerization initiator, the proportion of the rubbery polymer and the monomer mixture used is A suitable amount is 85-4 parts by weight of the monomeric polymer relative to 15-6 parts by weight of the rubbery polymer. If the monomer mixture used is less than 4 parts, it will be difficult to recover the resin as a powder, while if it exceeds 85 parts, it will be difficult to obtain a stable polymerization system. During graft polymerization, methods for adding the monomer generally include a method in which the entire amount is added at the start of polymerization, a method in which the monomer is added in two or more portions, and a method in which a portion or the entire amount is added continuously. However, in order to particularly improve the characteristics of the resin obtained by the present invention,
A method in which the monomer mixture is added in two or more portions, and a method in which a part or the entire amount of the monomer mixture is added continuously are preferred.

The graft polymerization initiators used in the present invention include organic hydroperoxides such as cumene hydroperoxide, diisopropylbenzene hydroperoxide, and/or ramenthane hydroperoxide, sugar-containing pyrophosphoric acid formulations, and sulfonate. Oxidation-reduction initiators in combination with reducing agents, such as xylate formulations, persulfates such as potassium persulfate and ammonium persulfate, azobisisobutyronitrile, penzoyl peroxide, lauroyl peroxide, etc. It can be used arbitrarily as needed.

Particularly in the present invention, oxidation-reduction type initiators are preferred. As the molecular weight regulator, mercaptans such as normal octyl mercaptan, normal dodecyl mercaptan, tertiary dodecyl mercaptan, and mercaptoethanol, and hydrogen halides such as chloroform and carbon tetrachloride can be used. Examples of emulsifiers include rosinate salts such as potassium rosinate and sodium rosinate, alkali metal salts of fatty acids such as potassium oleate, sodium oleate, potassium laurate, sodium laurate, sodium stearate, and potassium stearate, and sodium lauryl sulfate. Sulfuric acid ester salts of aliphatic alcohols such as sulfate ester salts of aliphatic alcohols, and alkylaryl sulfonates such as sodium dodecylbenzenesulfonate can all be used, and are not particularly limited. The graft polymer obtained in this way and 'B'
A thermoplastic resin key composition, which is the object of the present invention, can be obtained by mixing in a predetermined ratio.

Furthermore, if necessary, a commercially available acrylonitrile-styrene copolymer (AS resin) and additives such as stabilizers and additives may be mixed and used. Next, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples unless the gist thereof is exceeded. In Examples and Comparative Examples, % and parts mean % by weight and parts by weight, respectively. The particle protrusion distribution of latex was measured by the creaming method using sodium alginate.

The swelling degree of the rubbery polymer was measured as follows.

The rubber mass combined latex is poured onto a glass slope and allowed to dry naturally to form a film with a thickness of 2 ribs, from which film discs with a diameter of 2 melons are punched out.

The sample was immersed in 100% toluene, left in a storage room for 48 hours, the weight of the sample after swelling was measured, and the degree of swelling was calculated according to the following formula. The weight of the sample after swelling.

The soluble portion of the graft copolymer was extracted in acetone at room temperature, the weight of the remaining acetone-free portion was measured, and this weight was compared with the weight of the rubbery polymer used to produce the graft copolymer. The difference was calculated using the following formula as the weight of the monomer chemically bonded to the rubbery polymer. Grafting rate (%) =
(Weight of acetone 4-poor portion) - (Weight of rubbery polymer) XI.

〇 (Weight of rubbery polymer) Examples 1 to 4, Comparative Example 1
-Production of 4-polybutadiene latex (a-1) Polybutadiene latex (a-1) was produced in the following manner.

Butadiene 10 cities distilled water 100 Potassium rosinate 2.0 Potassium hydroxide 0.15 normal text Mercaptan 0.2 Potassium persulfate 0.3 was charged into a pressure-resistant reactor, and polymerization was started at 45 qo.

Furthermore, the reaction temperature was increased according to the polymerization conversion rate, and finally the conversion rate reached 90% in 7 to 8 q hours. After the polymerization was completed, unreacted butadiene was removed by steam distillation to obtain polybutadiene latex (a-1). Latex (a
-1) The moisture level and particle distribution are as follows. Iso brightness
15 Particle distribution (A) 4400 or more 5.2% 3100-4400 3.5 2100-310063.5 1730-210018.5 1470-1730 7.3 1470 or less 1.4 Both swelling degree and particle size distribution of the present invention It's in the abstract.

Production of polybutadiene latex (b-1) Polybutadiene latex (b-1) was produced by the following method.

Ptagene 100 (parts) distilled water 100 Potassium rosinate 1.0 Potassium hydroxide 0.15 normal dodecyl Mercaptan 0.5 Potassium persulfate 0.2 was charged into a pressure-resistant reactor and polymerization was started at 45°C.

The reaction is continued for about 1 hour by increasing the number of ropes when the softness rate is 40 to 50%. Thereafter, the bonito powder number was returned to the original value, 1.0 part of potassium rosinate was added, and the reaction temperature was increased according to the conversion rate, and finally the conversion rate reached 65% in 7 q hours at 65°C. After the polymerization was completed, unreacted butadiene was removed by steam distillation to obtain polybutadiene latex (b-1). latex(
The swelling degree and particle distribution of b-1) are as follows.

Swelling degree 83 Particle distribution (A) 4400-25000 70.4% 4400 or less 29.6 Both the degree of swelling and particle size distribution are within the scope of the present invention.

Graft polymers were produced using the rubbery polymer latexes (a-1) and (b-1) in the following manner.

Production of graft polymer (A-1) Rubber polymer (a-1) (solid content) 2 parts Styrene 28 Acrylonitrile 12 Normal dodicyl mercaptan 0.25 Potassium rosinate 1.5 Potassium hydroxide
0.08 water
150 The above mixture was charged into a reactor equipped with a hatching machine, and after replacing the inside with nitrogen, the jacket was
While controlling the temperature, raise the internal temperature to 4-0, and add 1
To this part, 0.35 part of sodium pyrophosphate, 0.4 part of dextrose, 0.0 part of ferrous sulfate, and 0.15 part of cumene hydroperoxide were added and reacted.

Next, one hour after the start of the reaction, the following mixture was continuously added over two hours to obtain a graft polymer latex with a reaction rate of 96.5%.

Styrene 28 parts Acrylonitrile 12 Normal dodecyl mercaptan 0.25 Potassium rosinate 0.5 Potassium hydroxide
0.05 Kiyumene Hydro/Goo Oxide 0.1 Water
50 After adding 0.5 part of 2,6-di-tertiarybutyl para-cresol as an anti-aging agent to this graft polymer latex, it was coagulated, washed with water and dried to obtain a graft polymer powder.

The grafting rate of this graft polymer was 65%. Production of graft polymer (B-1) Rubber polymer (b-1) 2 Styrene 28 Acrylonitrile 12 Normal dodecyl mercaptan 0.25 Potassium rosinate
1.5 potassium hydroxide
0.08 water
200 The above mixture was charged into a reactor equipped with a cylindrical reactor, the inside was replaced with nitrogen, and the jacket was heated to 70
While controlling the temperature, raise the temperature of the inner salt to 4-0, and add 1
To 5 parts, 0.35 part of sodium pyrophosphate, 0.4 part of dextrose, 0.0 $ part of ferrous sulfate, and 0.15 part of cumene hydroperoxide were added and reacted.

Next, one hour after the start of the reaction, the following mixture was continuously added over a period of three hours to obtain a graft polymer latex with a reaction rate of 93.2%.

Styrene 2
8 Acrylonitrile 12 Normal dodecyl mercaptan 0.25 Potassium rosinate 0.5 Potassium hydroxide 0.05 Qumento hydro/gu oxide 50 Add 2,6 tertiarybutylparacresol as an anti-aging agent to this graft polymer latex 0.5 After adding part, solidify, wash with water,
A graft polymer powder was obtained by drying.

The grafting rate of this graft polymer was 47%. Graft polymers (A-1) and (B-) obtained by the above method
The mixing ratio of 1) was changed as shown in Table 1, and 1.0 part of ethylene bisstearylamide was added and mixed to a total of 100 parts of both graft polymers, and Examples 1 to 4 of the present invention and comparative example For 1 to 4, 200 using a 40 rib extruder
Table 1 shows the results of pelletizing the test piece using qo and then molding it into a test piece using the method shown below, and measuring the physical properties.

In the same table, the orientation impact resistance (orientation Izod impact strength) is 3
．． Using a 5 oz injection molding machine, the molding temperature was 220°C.
A plate of x80 x 2.4 legs was molded.

From this plate, 55 x 12.7 in the parallel direction (Q direction) and perpendicular direction (8 directions) to the resin flow during molding.
Cut a test piece of ×2.4 ribs, make a notch in the center of one of the long sides of this test piece, and
-256, the impact strength was measured under environmental temperature conditions of 2yo and -30°C. Glossiness was measured in accordance with ASTM D-253 using a 5-ounce injection molding machine, using test pieces prepared under conditions of 15 minutes of dwell at 200oo and 28000.

Using a molded product with a Rockwell hardness of 200 oo,
It was measured under an ambient temperature condition of 23° C. according to ASTM D-785. The impact resistance after painting was measured using a 1 oz injection molding machine, after molding a 1'8 inch thick, unnotched Izotz impact strength test piece with 23000, the paint (Acryline 6 Group: manufactured by Fujikura Kasei Co., Ltd.: Product ) and thinner (
After applying a 1:1 mixture of Acryline Thinner Type 1 (manufactured by Fujikura Kasei Co., Ltd., product name) to a uniform coating thickness of 30°C using a spray gun, the coating was applied at a temperature of -30°C according to ASTM D-256. Measured under ambient temperature conditions.

Table 1 (Mixing ratio of kraft polymers) Comparative Examples 5 to 7 Production of graft polymer (A-2) Rubber polymer (a-1) (solid content) 2 styrene 56 acrylonitrile 24 normal dodecyl mercuff.

Tan 0.4 Potassium rosinate
2.0 potassium hydroxide
0.15 water
250 The above mixture was charged into a reactor equipped with a bridging machine, and after purging the inside with nitrogen, the internal temperature was raised to 40 qo while controlling the jacket at 70 qo, and water was poured into the base. Sodium phosphate 0.35 parts, dextrose 0
．． 4 parts of ferrous sulfate, 0.0 part of ferrous sulfate, and 0.4 part of cumene hydroperoxide were added and reacted in one step, and the reaction rate after 2 hours was 93.2%. The grafting rate of the graft polymer powder obtained by coagulating and drying this graft polymer latex in the same manner as in Examples 1 to 4 was 35%.

This value is lower than the grafting rate of the present invention. Production of graft polymer (B-2) Rubber polymer (b-
1) (solid content) 2 Wreath styrene
56 Acrylonitrile
24 normal dodecyl mercaptan
0.450 Potassium Rosinate
3.5 potassium hydroxide
0.2 water
250 Charge the above mixture into a reactor equipped with a sandbox,
After purging the inside with nitrogen, the internal temperature was raised to 40°C while controlling the jacket at 70°C, and 0.35 parts of sodium pyrophosphate and 0.0 parts of dextrose were added to 1 part of water.
．． 4 parts, 0.0 part of ferrous sulfate and 0.4 part of cumene hydroperoxide were added and reacted in one step, and the reaction rate after 2 hours was 93%.

The grafting rate of the graft polymer powder obtained by coagulating and drying this graft polymer latex in the same manner as in Examples 1 to 4 was 29%.

This value is lower than the grafting rate of the present invention. The above graft polymer powders (A-2) and (8-2) and the graft polymers (A-1) and (
B-1) in the combinations shown in Table 2, 1.0 part of ethylene bisstearylamide was added to and mixed with a total of 10 bases of both graft polymers, and a 4-piece extruder was used. 200,000, and Example 3 of the present invention
The physical properties of Comparative Examples 5 to 7 were measured. The results are shown in Table-2. Table 2 (Effect of kraft rate) Comparative Examples 8 to 10 Production of polybutadiene latex (a-2) Polybutadiene latex (a-2) was produced by the following method.

In the production of polybutadiene latex (a-1) in Examples 1 to 4, the polybutadiene latex (a-1) was prepared with the exception of adding 3.5 parts of potassium rosinate and straining distilled water 18 times.
Polymerization was carried out in the same manner as in -1), and finally 65q0
, reached a 90% roll rate in 5 hours. After the polymerization is complete, the reacted ptagene is removed and a polyptadiene latex (a-
2) was obtained. The swelling degree and particle weight distribution of latex (a-2) are as follows.

Swelling degree 13 Particle distribution (A) 6600 or more - 4400~6600A 2.5% 3100~4400 4.8 2100~3100 5.7 1730~2100, 14.8 1470~1730 236 1470 or less 486 Latex (a- 2) has a particle size of 1500-4000A
Less than 70% of the particles are present in the sample, which does not meet the requirements specified in the present invention.

Production of polybutadiene latex (b-2) In the production of polybutadiene latex (b-1), 2. Polymerization was carried out in the same manner as for polybutadiene latex (b-1) except that the base portion and distilled water were changed to 150 parts, and the conversion rate was finally reached at 60° C. for 59 hours.

After the polymerization was completed, unreacted butadiene was removed to obtain voriptadiene latex (b-2). The swelling degree and particle size distribution of latex (b-2) are as follows.

Swelling concentration 73 Particle size distribution (A) 4400A or more 35.7%31
00~4400 7.03100 or less
57.3 Latex (b-2) has less than 50% of particles with a particle size of 4000A or more, and does not meet the requirements specified in the present invention.

Graft polymers were produced by the following method using polyptagene latexes (a-2) and (b-2) whose particle size distributions were outside the specifications of the present invention.

Production of graft polymer (A-3) Graft polymer (A-
In the production of 1), graft polymerization was carried out in the same manner as in the production of (A-1) except that rubbery polymer (a-2) was used instead of rubbery polymer (a-1). A graft polymer latex was obtained at 2%.

This graft polymer latex is used as an anti-aging agent.
After adding 0.5 part of 6-ditertiarybutyl para-cresol, the mixture was coagulated, washed with water, and dried to obtain a graft polymer powder. The grafting rate of this graft polymer was 67%. Production of graft polymer (B-3) Graft polymer (B-3)
In the production of -1), graft polymerization was carried out in the same manner as in the production of (B-1) except that rubbery polymer (b-2) was used instead of rubbery polymer (b-1), and the reaction rate was controlled. A graft polymer latex was obtained at 2%.

This graft polymer latex contains 2 as an anti-aging agent.
After adding 0.5 part of 6-ditertyabutyl para-cresol, the mixture was coagulated, washed with water, and dried to obtain a graft polymer powder.

The grafting rate of this graft polymer was 52%. The above graft polymer powders (A-3) and (B-3) and the graft polymers (A-1) and (
B-1) in the combinations shown in Table 3, and for a total of 10 parts of both graft polymers, 1 part of ethylene bisstearylamide was added. The eaves were added and mixed, and the mixture was made into pellets using an extruder at 20 mm, and the physical properties of Example 3 of the present invention and Comparative Examples 8 to 10 were measured.

The results are shown in Table-3. Table-3 Comparative Examples of Particle Size Distribution Effects 11 to 13 Polybutadiene Latex (Production of a-3) Polybutadiene latex (a-3) was produced in the following manner.

In the method for producing polybutadiene latex (a-1) of Examples 1 to 4, 0.
Polybutadiene latex (a-1
) Polymerization was carried out in the same manner as in the production method, and finally 70
℃, the rolling rate reached % after 7 hours. After the polymerization is complete, unreacted butadiene is removed and polybutadiene latex (a-
3) was obtained. The swelling degree and particle size distribution of latex (a-3) are as follows.

Swelling degree 50 Particle distribution (A) 6600A or more -4400~6
600A I. 3 3100-4400 4.2 2100-3100 21.7 1730-2100 35.4 1470-1730 23.7 1470 or less 137 In this latex (a-3), 70% or more of the particles have a particle size in the range of 1500 to 4000A. However, the degree of swelling is 5
Since it is 0, the requirements stipulated by the present invention are not met.

Production of polybutadiene latex (b-3) Polybutadiene latex (b-3) was produced in the following manner.

Polybutadiene latex (b-1) of Examples-1 to 4
In the production of polybutadiene latex (b-1), a polymerization rate of 62% was reached in the same manner as in the production of polybutadiene latex (b-1), except for newly adding 0.4 parts of divinylbenzene. After the polymerization, unreacted butadiene was removed and polybutadiene latex (b
-3) was obtained. The swelling degree and particle size distribution of (b-3) are as follows.

Iso moisture level 31 Particle light distribution (A) 4400 or more 59.8%44
00 or less 40.2 This latex (b-3) has 50% or more of particles with a particle weight of 4000 A or more, but the degree of swelling is 31, so it does not meet the requirements specified in the present invention.

Graft polymers were produced in the following manner using polybutadiene latexes (a-3) and (b-3) whose degree of wing expansion was outside the requirements stipulated by the present invention. Production of graft polymer (A-4) In the production of graft polymer (A-4), (A-3) was used instead of rubbery polymer (a-1).
Graft polymerization was carried out in the same manner as in 1) to obtain a graft polymer latex with a reaction rate of 96.5%.

This graft polymer latex contains 2 as an anti-aging agent.
, 6-di-tert-butylpara-cresol was added thereto, followed by coagulation, washing with water, and drying to obtain a graft polymer powder. The grafting rate of this graft polymer was mottled %. Production of graft polymer (B-4) Graft polymer (B-4)
In the production of -1), graft polymerization was carried out in the same manner as in the production of (B-1), except that (b-3) was used instead of the rubbery polymer (b-1), and the reaction rate was uneven. A graft polymer latex was obtained at 1%.

This graft polymer latex contains 2,
After adding 0.5 part of 6-ditertyabutyl para-cresol, the mixture was coagulated, washed with water, and dried to obtain a graft polymer powder.

The grafting rate of this graft polymer was 49%. The above graft polymer powders (A-4) and (B-4) and the graft polymers (A-1) and (
B-1) in the combination shown in Table 4, 10 parts of ethylene bisstearylamide was added and mixed to a total of 10 parts of both graft polymers, and the mixture was heated at 200 qo using a four-way extruder. The pellets were formed into pellets, and the physical properties of Example 5 of the present invention and Comparative Examples 11 to 13 were measured.

The results are shown in Table 4. Comparative Example 14 Production of Graft Polymer (AB-1) In the production of graft polymers (A-1) in Examples 1 to 4, rubbery polymer (AB-1) was substituted with two anchors. Combined (a-1) 14 parts and rubbery polymer (b-1) 6
Graft polymerization was carried out in the same manner as in Examples 1 to 4, except that the mixed rubbery polymer latex 2 of 1. A graft polymer latex was obtained at 5%.

This graft polymer latex was coagulated and dried in the same manner as in Examples 1 to 4, and the grafting ratio of the graft polymer powder obtained was spherical %.

0 Graft polymer (AB-1) obtained by the above method 100
1 part of ethylene bisstearylamide was added and mixed, and the mixture was pelletized at 200 pm using a four-arm extruder to prepare a test piece, and its physical properties were measured.

The results are shown in Table 4. Table-4 (Effect of degree of swelling)

Claims (1)

[Scope of Claims] 1. A thermoplastic resin composition consisting of a mixture of graft copolymers A and B shown below, in which the weight ratio of A and B is within the range of 40:60 to 90:10. (A) More than 70% of the particles have a particle size of 1500 to 4000 Å
rubbery polymer latex with a swelling degree of 30 or less, at least one vinyl aromatic monomer, at least one vinyl cyan monomer, and optionally a (meth)acrylic acid ester monomer. A graft copolymer having a graft ratio of 40% or more, which is obtained by graft polymerizing a monomer mixture containing at least one type of monomer. (B) 50% or more of the particles have a particle size of 4000 to 25000
At least one vinyl aromatic monomer, at least one vinyl cyan monomer, and optionally a (meth)acrylic acid ester monomer are added to a rubbery polymer latex having a swelling degree of 70 or more. A graft copolymer having a graft ratio of 40% or more, which is obtained by graft polymerizing a monomer mixture containing at least one type of monomer. 2. The thermoplastic resin according to claim 1, wherein the monomer mixture used in the graft copolymerization contains 50% by weight or more of a vinyl aromatic monomer and 10% by weight or more of a vinyl cyan monomer. Composition. 3 The ratio of the rubbery polymer and monomer mixture used is 85 to 60 parts by weight of the rubbery polymer to 85 to 60 parts by weight of the rubbery polymer.
The thermoplastic resin composition according to claim 1, comprising 40 parts by weight. 4. The thermoplastic resin composition according to claim 1, wherein the initiator used in the graft polymerization is an oxidation-reduction type initiator.