JPH1180280A - Preparation of rubber-like copolymer latex and thermoplastic resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a preparation method for a rubber-like copolymer latex which is anti-putrefaction and excellent in productivity and modifiability for its shock resistance. SOLUTION: A rubber-like copolymer latex is prepared by polymerizing 50-99 wt.% of a diene monomer and 1-50 wt.% of an aromatic vinyl monomer which is copolymerizable with the diene monomer using a polymerization initiator for which a formaldehyde sulfoxylate salt is used as a redox-initiator type of a secondary reducing agent at a polymerization temperature of less than 72 deg.C, adding 0.01-1.0 wt.% of a mercaptan compound when the conversion ratio of polymerization reaches 10-70% and continuing the polymerization.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a rubbery copolymer latex having excellent rot resistance and productivity and a thermoplastic resin having excellent impact resistance obtained by using the rubbery copolymer latex. About resin.

[0002]

2. Description of the Related Art Various types of thermoplastic resins having excellent impact resistance have been used, but in applications where molding processability and appearance are important, the balance is excellent. ABS resins are widely used as thermoplastic resins. However, in recent years, the required performance has become severe, and depending on the application, the impact resistance of an ABS resin is insufficient, and its improvement is required.

The ABS resin is a resin obtained by adding a rubber component to an AS resin (acrylonitrile-styrene copolymer) as an impact resistance improver. The ABS resin is a matrix resin and the rubber component is graft copolymerized with the AS component. Composed of a graft copolymer.

In order to improve the impact resistance of the ABS resin, there is a method of increasing the molecular weight of the AS copolymer as a matrix resin. However, in this method, the fluidity of the ABS resin, that is, the moldability is reduced. descend. Further, when the blending amount of the graft copolymer is increased, the impact resistance is improved, but the hardness or the elastic modulus is lowered, and the fluidity and the heat resistance are also lowered. In order to maintain a balance with other performances as described above, there is a limit in changing the type of the AS copolymer or changing the blending amount of the graft copolymer. Therefore, in order to improve the impact resistance, It is necessary to improve the performance of the graft copolymer as an impact resistance improver. In the polymer alloy resin composition, which is another wide area, it is important to improve the performance of the graft copolymer as an impact modifier.

[0005] Focusing on the graft copolymer component, A
The impact resistance of BS resin mainly depends on its constituent rubber components. It is well known that the particle size of the rubber component of the graft copolymer affects the impact resistance. For the Izod impact strength, the weight average particle size of the rubber component is about 0.25 to 0.30 μm. The maximum value of the Izod impact strength exists in the range. Rubber component of such particle size,
That is, if a rubber-like polymer is to be formed during polymerization in emulsion polymerization, an extremely long polymerization time is required, and the productivity is poor.

[0006] In order to solve this poor productivity, a relatively small rubbery polymer is emulsion-polymerized in a short time, and this is enlarged by some method to obtain a desired particle size.
-79366, JP-A-59-93701,
It is disclosed in JP-A-56-167704 and the like.
However, in such a method, in order to complete the polymerization in a short time when polymerizing the rubber-like polymer, if the polymerization is to be completed within 8 hours, for example, the polymerization at a relatively high temperature of about 50 ° C. or higher is required. In the final stage of the polymerization, the rubber-like polymer is liable to be excessively cross-linked, resulting in a problem that the impact resistance of the ABS resin is reduced.

In view of the balance between the polymerization temperature and the polymerization time for obtaining a rubber-like polymer having a small particle diameter by a short time emulsion polymerization, a redox initiator emulsion polymerization is desirable, and among them, a secondary reducing agent is preferred. As a redox initiator system using a sugar such as dextrose, the polymerization rate is high. However,
The rubber latex obtained by the sugar-containing redox initiator-based polymerization method is not limited to the rubber latex for ABS resin, and has a problem that it rots during storage during storage in production.

[0008]

DISCLOSURE OF THE INVENTION In view of the above-mentioned situation, the present inventors have developed a method for producing a rubbery polymer latex having excellent rot resistance and excellent impact resistance improving ability with good productivity. As a result of diligent studies, the present invention has been achieved.

That is, the present invention relates to a diene monomer
A monomer composed of 99 parts by weight and 1 to 50 parts by weight of an aromatic vinyl monomer copolymerizable therewith (total 100 parts by weight)
Is polymerized at a polymerization temperature of less than 72 ° C. using a polymerization initiator comprising a formaldehyde sulfoxylate salt as a redox initiator-based secondary reducing agent, and the polymerization conversion is 10%.
When it reaches ~ 70%, the mercaptan compound 0.01
To 1.0 part by weight and polymerizing the rubbery copolymer latex, and the rubbery copolymer latex obtained by the method as it is or the rubbery copolymer latex Thermoplastic consisting of a graft copolymer obtained by polymerizing a monomer mixture containing a vinyl cyanide-based monomer and an aromatic vinyl-based monomer as essential components in the presence of an enlarged particle size Resin.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, a monomer used for producing a rubbery copolymer latex is a monomer comprising a diene monomer and an aromatic vinyl monomer copolymerizable therewith. It is a mixture.

Examples of diene monomers include, for example, 1,
Aliphatic diene-based monomers such as 3-butadiene, isoprene, and chloroprene are listed.
The use of butadiene is preferred.

An aromatic vinyl monomer copolymerizable with a diene monomer is used for suppressing the crosslinking of the rubbery copolymer, increasing the polymerization rate and improving the productivity. Examples thereof include styrene, α-methylstyrene, vinyltoluenes such as p-methylstyrene, halogenated styrenes such as p-chlorostyrene, pt-butylstyrene, dimethylstyrene, vinylnaphthalenes and the like. , Preferably styrene.

The ratio of the diene monomer used for producing the rubbery copolymer latex to the copolymerizable aromatic vinyl monomer is 50 to 99 parts by weight of the diene monomer. To the copolymerizable aromatic vinyl monomers 1 to 5
0 parts by weight (100 parts by weight in total). If the amount of the diene monomer is less than 50 parts by weight, the impact resistance modifying ability of the rubbery copolymer is reduced, while if the amount of the aromatic vinyl monomer is less than 1 part by weight, The impact resistance modifying ability of the copolymer is reduced.

The rubbery copolymer latex of the present invention is produced by emulsion polymerization. In this case, as a method for adding a mixture of an aromatic vinyl monomer copolymerizable with a diene monomer, The method is not particularly limited, and examples include a method of adding the whole amount before the polymerization is started, a method of adding twice or more, and a method of adding a part or the whole amount continuously or intermittently.

The method of adding water used for the polymerization is not particularly limited, either.
A method of dividing into two or more times and charging before and during polymerization,
A method in which a part or the whole amount is continuously charged during the polymerization is exemplified.

In the production of the rubbery copolymer latex, rosinates such as disproportionated potassium rosinate, disproportionated sodium rosinate, potassium oleate, sodium oleate, potassium laurate, Sodium laurate, potassium stearate,
Fatty acid salts such as sodium stearate, sulfate salts of aliphatic alcohols such as sodium lauryl sulfate, sulfonates such as sodium dodecylbenzenesulfonate,
Examples include n-acyl amino acid salts such as sodium lauroyl sarcosinate, and phosphoric ester salts such as sodium oleyl phosphate. These emulsifiers can be used alone or in combination of two or more.

As the polymerization initiator used in the production of the rubbery copolymer latex, an organic hydroperoxide such as cumene hydroperoxide, diisopropylbenzene hydroperoxide or paramenthane hydroperoxide is used as a radical generator. As the agent, metal ions such as iron ion and copper ion, and as a stabilizer thereof, pyrophosphate or EDTA (ethylenediaminetetraacetic acid) salt, and as a secondary reducing agent, formaldehyde sulfoxylate salt is used. The amount of use is not particularly limited, but it is desirable to use an appropriate amount according to the purpose. Further, other radical generators can be used in combination depending on the purpose.

It is important that the formaldehyde sulfoxylate salt as the secondary reducing agent used in the production of the rubbery copolymer latex of the present invention is water-soluble. As a water-soluble compound industrialized, there is sodium salt dihydrate, and its use is preferred.

In the present invention, when a formaldehyde sulfoxylate salt is not used as the secondary reducing agent of the redox initiator, for example, dextrose is used, the obtained rubber-like copolymer latex tends to spoil, which is not preferable.
When potassium persulfate is used as the polymerization initiator, the obtained rubbery copolymer latex has a lower decay property than the formaldehyde sulfoxylate salt-based latex, though the decay progresses more slowly than the dextrose-based latex. In addition, since the polymerization rate at the time of latex polymerization is low, the production is poor, which is not preferable. Further, if the polymerization rate is increased by another method and the polymerization rate is made equal to that of the redox polymerization method, the impact resistance modifying ability of the rubbery copolymer obtained is reduced.

It is important that the polymerization temperature for obtaining the rubbery copolymer latex is less than 72 ° C. this is,
This is because the higher the polymerization temperature, the lower the impact resistance modifying ability of the obtained rubbery copolymer tends to be. Preferably it is lower than 68 ° C.

The rubbery copolymer latex of the present invention is produced by emulsion polymerization using the above-mentioned monomer, emulsifier and polymerization initiator.
It is important to add the mercaptan-based compound at the time of reaching 0%.

Specific examples of the mercaptan-based compound that can be added include, for example, n-octyl mercaptan, t-octyl mercaptan, n-dodecyl mercaptan, mercaptoethanol, mercaptopropionic acid, and preferably n-dodecyl acid. Mercaptan. The number of additions is not particularly limited. Further, this does not limit the use of a chain transfer agent such as mercaptan used at the start of polymerization for controlling the molecular weight, which is found in known emulsion polymerization methods.

The addition amount of the mercaptan compound is in the range of 0.01 to 1.0 part by weight based on 100 parts by weight of the monomer mixture. This is because if the added amount of the mercaptan-based compound is less than 0.01 part by weight or exceeds 1.0 part by weight, the obtained rubbery copolymer has a reduced impact resistance improving ability.

The addition of the mercaptan-based compound results in a polymerization conversion of the above monomer mixture of 10 to 70%, preferably 2 to 70%.
It is added at the point when it reaches 0 to 60%, but when the polymerization conversion rate at the time of addition is less than 10% or more than 70%, the impact resistance modifying ability of the obtained rubbery copolymer decreases. I do.

Next, the thermoplastic resin of the present invention comprises a graft copolymer obtained by polymerizing a monomer mixture in the presence of the rubbery copolymer latex obtained as described above. You.

The graft copolymer of the present invention can be produced by a known polymerization method. For example, emulsion polymerization, suspension polymerization, solution polymerization, bulk polymerization, or a combination of two or more of these can be used. Emulsion polymerization is most suitable because a rubbery copolymer is produced by emulsion polymerization. For example, a monomer mixture is added to the rubbery copolymer latex obtained by emulsion polymerization, and graft polymerization is performed by a known method.

The monomer mixture used for the graft polymerization contains a vinyl cyanide monomer and an aromatic vinyl monomer as essential components, and if necessary, an unsaturated carboxylic acid ester monomer. And a monomer mixture to which one or more monomers selected from the group consisting of unsaturated dicarboxylic anhydrides and unsaturated dicarboxylic imide compounds are added.

As the vinyl cyanide monomer used for the graft polymerization, acrylonitrile, methacrylonitrile, vinylidene cyanide and the like can be used, but acrylonitrile is preferred.

The amount of the vinyl cyanide monomer used is preferably 5 to 50% by weight, more preferably 5 to 30% by weight, in the monomer mixture to be graft-polymerized. If it is less than 5% by weight, the impact resistance of the resin is low, and
If the amount is more than 10% by weight, the fluidity of the obtained resin tends to decrease.

Examples of the aromatic vinyl monomer used for the graft polymerization include vinyl toluenes such as styrene, α-methylstyrene and p-methylstyrene, halogenated styrenes such as p-chlorostyrene, -T-butylstyrene, dimethylstyrene, vinylnaphthalenes and the like can be used, and styrene or α-methylstyrene is preferable as a raw material. These vinyl monomers may be used alone or in combination of two or more.

The amount of the aromatic vinyl monomer used is preferably 50 to 95% by weight, more preferably 70 to 95% by weight, in the monomer mixture to be grafted.
If it is less than 70% by weight, the fluidity of the resin is reduced,
If the content is more than 10% by weight, the impact resistance of the resin tends to decrease.

Examples of unsaturated carboxylic acid ester monomers that can be used for graft polymerization include, for example, methyl acrylate, ethyl acrylate, n-butyl acrylate,
Examples thereof include 2-ethylhexyl acrylate, n-hexyl acrylate, methyl methacrylate, and ethyl methacrylate.

The unsaturated dicarboxylic anhydride which can be used for the graft polymerization includes, for example, maleic anhydride, itaconic anhydride, citraconic anhydride and the like. Preferably, it is maleic anhydride.

Further, examples of the imide compound of unsaturated dicarboxylic acid include maleimide, N-methylmaleimide, N-butylmaleimide, N-phenylmaleimide,
N-cyclohexylmaleimide and the like can be mentioned. Preferred is N-phenylmaleimide.

The amount of these other copolymerizable monomers used is from 0 to 4 in the monomer mixture used for graft polymerization.
When the amount exceeds 40% by weight, the impact resistance of the resin tends to decrease.

In the present invention, if necessary, other monomers such as glycidyl methacrylate, methacrylic acid, acrylic acid, methacrylamide, 2-hydroxyethyl methacrylate and polyethylene glycol monomethacrylate are added in an amount of 40% by weight or less. Preferably, an amount of not more than 30% by weight can be used in the monomer mixture.

The particle size and distribution of rubber in the rubbery copolymer latex used to obtain the graft polymer are not particularly limited, and the obtained rubbery copolymer latex may be used as it is or may be different in particle size. A graft copolymer may be produced using two or more rubbery copolymer latexes in combination. In addition, it is also possible to enlarge and use the rubbery copolymer latex obtained in some way,
A graft copolymer may be produced by using two or more types of enlarged rubbery copolymer latexes having different weight average particle sizes.

Known methods can be used for the process of enlarging the particle size of the rubber-like copolymer. For example, a method of enlarging the rubber-like copolymer by shearing stress by stirring or the like, or a method of enlarging by adding an acid. A method, a method of adding an acid group-containing copolymer latex to increase the size, and the like can be used.

The particle size of the rubbery copolymer is preferably in the range of 0.1 to 3 μm, more preferably 0.2 to 0.4 μm, from the viewpoint of impact resistance.

The proportion of the monomer mixture to be grafted to the rubbery copolymer is preferably in the range of 20 to 90 parts by weight of the monomer mixture with respect to 10 to 80 parts by weight of the rubbery copolymer.
More preferably, the amount is 30 to 70 parts by weight (total 100 parts by weight) based on 30 to 70 parts by weight of the rubbery copolymer. When the amount of the rubber-like copolymer is less than 10 parts by weight, the impact resistance of the obtained resin is reduced, and when it exceeds 80 parts by weight, the graft ratio to the rubber-like copolymer is reduced. However, even if the amount of the rubbery polymer in the obtained resin is increased, the impact resistance and the gloss are reduced.

When graft-polymerizing the rubbery copolymer, the monomer mixture may be added all at once, or may be added in portions, continuously dropped, or individually dropped stepwise. The addition method is not particularly limited.

In the graft polymerization, known emulsifiers, dispersants, solvents, catalysts and initiators are usually used, and there are no particular restrictions on the type, amount or method of addition.

The graft copolymer obtained by graft polymerization by the emulsion polymerization method can be recovered as a powdery solid by a coagulation with an acid or a salt, which is a usual method for recovering a polymer from a latex, and a drying step.

The graft copolymer obtained by the present invention can be used alone as a thermoplastic resin, but may be used by blending another thermoplastic resin according to the purpose. Other thermoplastic resins that can be blended include, for example, polystyrene, styrene-acrylonitrile copolymer, styrene-methyl methacrylate copolymer, styrene-maleic anhydride copolymer, and acrylonitrile-styrene-maleimide compound ternary. Copolymer, methyl methacrylate-styrene-maleimide compound terpolymer, methyl methacrylate-acrylonitrile-styrene-maleimide compound quaternary copolymer, acrylonitrile-α-methylstyrene copolymer,
Polymethyl methacrylate, polyvinyl chloride, polycarbonate, polyesters such as polyethylene terephthalate and polybutylene terephthalate, polyamides and the like are included. One or two or more of the above thermoplastic resins can be blended.

The thermoplastic resin of the present invention may contain, if necessary, suitable stabilizers (eg, antioxidants, heat stabilizers, ultraviolet absorbers, etc.), plasticizers, flame retardants, antistatic agents, release agents. , A foaming agent, an antibacterial agent, and the like, and a reinforcing filler such as glass fiber, glass powder, carbon fiber, and inorganic filler.

If necessary, ABS resin, AAS (acrylonitrile-acryl-styrene) resin, AES
(Acrylonitrile-ethylene-styrene) resin, AS
S (acrylonitrile-silicone-styrene) resin,
A silicone modifier or the like can also be added.

Devices such as a Henschel mixer, a Banbury mixer, an extruder and a heating roll are used for the mixing, and useful molded articles can be obtained by various molding methods such as injection molding and extrusion molding.

The thermoplastic resin of the present invention can be used for structural and mechanical parts of OA equipment such as computers, printers and copiers, and structural and mechanical parts of AV equipment such as TVs, VCRs, stereo decks and video cameras. , Vehicle electrical components and structural / mechanical components of interior / exterior components,
It is used for structural parts and mechanical parts of lighting appliances, refrigerators, washing machines, electronic (oven) ranges, rice cookers, pots, vacuum cleaners, and structural parts and mechanical parts of home appliances such as air conditioner indoor / outdoor units.

[0049]

The present invention will be described below in detail with reference to examples. The following Examples and Comparative Examples are provided for more specific explanation, and are not limited to the following Examples. In the following Examples and Comparative Examples,% and parts are by weight unless otherwise specified. In the following Examples and Comparative Examples, various physical properties were measured by the following methods.

(1) Particle Size of Rubbery Polymer The weight average particle size was determined using a transmission electron microscope.

(2) Izod impact strength Measured according to ASTM D256.

(3) Melt flow rate According to JIS K7210, temperature 200 ° C., load 5 kg
And measured in terms of g of outflow per 10 minutes.

(4) Corrosion resistance Put 4 kg of rubbery polymer latex in a 5 liter container, leave it open and open, and collect a sample every week to visually check the number of breeding bacteria (the number of colonies). Counting and decay resistance were evaluated according to the following criteria. (Unit: number of bacteria (pieces) / volume of latex (ml)) ○: No number of bacteria, no decay ×: Number of bacteria of 10 ³ or more

(5) Surface gloss: Measured according to ASTM D523.

Example 1 (1) Production of Rubbery Polymer Latex (A-1) In a 10-liter stainless steel autoclave, 150 parts of deionized water (hereinafter simply referred to as water) and 1 part of potassium rosinate were added. , Potassium oleate 1 part, sodium formaldehyde sulfoxylate dihydrate 0.4 part, sodium sulfate 0.1 part, t-dodecyl mercaptan 0.3 part,
Diisopropylbenzene hydroperoxide 0.5
Parts, 1,3-butadiene 26.2 parts and styrene 1.
4 parts were charged and heated to 57 ° C. During the heating, 0.2 part of sodium pyrophosphate and 0.003 part of ferrous sulfate heptahydrate were added to initiate polymerization. At a polymerization temperature of 57 ° C, a monomer composed of 68.8 parts of 1,3-butadiene and 3.6 parts of styrene was continuously dropped. Next, when the polymerization conversion reached 40%, 0.3 part of n-dodecyl mercaptan was added, and the polymerization was further continued. Eight hours later, the remaining 1,3-butadiene is removed, and a rubbery copolymer latex having a solid content of 40.2%, a polymerization conversion of 97%, a weight average particle diameter of 0.07 μm and a pH of 10.0. (A-1) was obtained. Table 1 shows the evaluation results of the rot resistance of the obtained rubbery copolymer latex (A-1).

(2) Acid group-containing copolymer latex (B-
Preparation of 1) 200 parts of water, 2 parts of potassium oleate, 2.3 parts of sodium dioctyl sulfosuccinate and 0.3 part of sodium formaldehyde sulfoxylate dihydrate were charged into a 5 liter glass reactor, and heated to 60 ° C. The temperature was raised, and from that time, a mixture consisting of 86 parts of n-butyl acrylate, 14 parts of methacrylic acid and 0.5 part of cumene hydroperoxide was continuously dropped over 120 minutes. Further, after aging for 2 hours, the solid content was 33.0%, the polymerization conversion was 99%, and the weight average particle size was 0.08 μm.
Was obtained as the acid group-containing copolymer latex (B-1).

(3) Production of Enlarged Rubbery Copolymer Latex (C-1) In a 5 liter glass reactor, 248.8 parts of the above rubbery copolymer latex (A-1) (100% solids)
Parts), and 6.1 parts (2 parts as a solid content) of the above acid group-containing copolymer latex (B-1) was added under stirring, followed by stirring for 30 minutes to obtain a weight average particle diameter. An enlarged rubbery copolymer latex (C-1) having a solid content of 0.27 μm and a solid content of 39.2% was obtained.

(4) Production of Graft Copolymer (D-1) In a 5 liter glass reactor, 150 parts of water and 249.9 parts of the above-mentioned enlarged rubbery copolymer latex (C-1) (solid content) 100 parts), 0.6 parts dextrose,
0.1 part of sodium pyrophosphate and 0.01 part of ferrous sulfate heptahydrate were charged, and after replacing with nitrogen, the temperature was raised to 60 ° C.
A mixture of 30 parts of acrylonitrile, 70 parts of styrene, 1.2 parts of t-dodecylmercaptan and 0.3 part of cumene hydroperoxide was added dropwise over 200 minutes,
During that time, the internal temperature was controlled to be 65 ° C.

After the completion of the dropwise addition, 0.12 parts of cumene hydroperoxide was added, and the mixture was kept for 1 hour. After adding 1 part of an antioxidant (Antage W-400, manufactured by Kawaguchi Chemical Industry Co., Ltd.), the mixture was cooled. did. This graft copolymer latex (D-1) was coagulated with a 5% aqueous sulfuric acid solution, washed and dried to obtain a milky white powder of the graft copolymer (D-1).
The polymerization conversion was 97%.

Next, the graft copolymer (D-1)
40 parts and acrylonitrile (AN) -styrene (S
t) 60 parts of a copolymer (AN / ST weight ratio = 30/70, melt flow rate 3.6 g / 10 min, abbreviated as AS resin hereinafter) at 200 ° C using a twin-screw extruder. Then, after pelletizing, a test piece was prepared by injection molding and the physical properties were evaluated. Table 2 shows the obtained results.

Example 2 (1) Production of Rubbery Copolymer Latex (A-2) In a 10-liter stainless steel autoclave, water 15 was added.
0 parts, 1 part of potassium rosinate, 1 part of potassium oleate
Parts, sodium formaldehyde sulfoxylate dihydrate 0.4 part, sodium sulfate 0.1 part, t-dodecyl mercaptan 0.3 part, diisopropylbenzene hydroperoxide 0.5 part, 1,3-butadiene 90 parts and 10 parts of styrene was charged and the temperature was raised to 55 ° C. During the heating, 0.2 parts of sodium pyrophosphate and 0.003 parts of ferrous sulfate heptahydrate were added to initiate polymerization. When the polymerization conversion reached 60%, 0.2 part of n-dodecyl mercaptan was added, and the polymerization was further continued. Eight hours later, the remaining 1,3-butadiene is removed, and a rubbery copolymer latex having a solid content of 40.2%, a polymerization conversion of 97%, a weight average particle size of 0.07 μm and a pH of 10.2 (A
-2) was obtained.

(2) Production of Enlarged Rubbery Copolymer Latex (C-2) In a 5 liter glass reactor, 248.8 parts of the above rubbery copolymer latex (A-2) (solid content) 100
Parts) and sodium dodecylbenzenesulfonate 0.
3 parts were charged, and 40 parts of a 5% aqueous phosphoric acid solution was added dropwise over 3 minutes, and then a 10% aqueous sodium hydroxide solution 10
And a rubbery copolymer latex (C) having a solid content of 27.9% and a weight average particle diameter of 0.27 μm.
-2) was obtained.

(3) Production of Graft Copolymer (D-2) In the production of the graft copolymer (D-1) described in Example 1 (4), the rubbery copolymer latex (C
-1) is converted to the above-mentioned enlarged rubbery copolymer latex (C-
2) and the graft copolymer (D-) was prepared in the same manner as in Example 1 (4) except that the amount of water was adjusted in terms of solid content.
2) was obtained. The polymerization conversion was 97%.

Next, the graft copolymer (D-2)
Forty parts and 60 parts of the AS resin of Example 1 were blended using a twin-screw extruder in the same manner as in Example 1, pelletized, and a test piece was prepared by injection molding to evaluate physical properties. Table 2 shows the obtained results.

Example 3 (1) Production of Rubbery Copolymer Latex (A-3) Same as Example 1 (1) except that the polymerization temperature after completion of the dropwise addition of the monomer was changed to 67 ° C. To perform polymerization. After 6 hours, the remaining 1,3-butadiene was removed, and the solid content was 40.1.
%, Polymerization conversion rate is 97%, weight average particle diameter is 0.06μ
A rubbery copolymer latex (A-3) having m and pH of 10.0 was obtained.

(2) Production of enlarged rubber-like copolymer latex (C-3) Rubber used in production of enlarged rubber-like copolymer latex (C-1) described in Example 1 (3) Except that the rubbery copolymer latex (A-1) was changed to the above rubbery copolymer latex (A-3), the weight average particle diameter was 0.27 μm and the same as in Example 1 (3). An enlarged rubbery copolymer latex (C-3) having a solid content of 39.4% was obtained.

(3) Production of Graft Copolymer (D-3) In the production of the graft copolymer (D-1) described in Example 1 (4), the rubbery copolymer latex (C) used
Example 1 except that -1) was changed to the above-described enlarged rubbery copolymer (C-3) and the amount of water was adjusted in terms of solid content.
In the same manner as in (4), a graft copolymer (D-3) was obtained. The polymerization conversion was 97%.

Next, the graft copolymer (D-3)
Forty parts and 60 parts of the AS resin of Example 1 were blended using a twin-screw extruder in the same manner as in Example 1, pelletized, and a test piece was prepared by injection molding to evaluate physical properties. Table 2 shows the obtained results.

Comparative Example 1 (1) Production of Rubbery Polymer Latex (A-4) In a 10 liter stainless steel autoclave, water 15 was added.
0 parts, 1 part of potassium rosinate, 1 part of potassium oleate
Parts, sodium sulfate 0.3 parts, dextrose 0.4
Part, t-dodecyl mercaptan 0.3 part, diisopropylbenzene hydroperoxide 0.5 part and 1,
100 parts of 3-butadiene was charged and heated to 50 ° C. During the heating, 0.2 parts of sodium pyrophosphate and 0.003 parts of ferrous sulfate heptahydrate were added to initiate polymerization. When the polymerization conversion reached 60%, 0.2 part of n-dodecyl mercaptan was added, and the polymerization was further continued. After 8 hours, the remaining 1,3-butadiene is removed, and a rubbery polymer latex having a solid content of 40.2%, a polymerization conversion of 97%, a weight average particle diameter of 0.07 μm and a pH of 10.0 ( A-
4) was obtained. The obtained rubbery polymer latex (A-
For 4), the rot resistance was evaluated in the same manner as in Example 1. The results are shown in Table 1.

(2) Enlarged rubbery polymer latex (C
Production of -4) In the production of the enlarged rubber-like copolymer latex (C-1) described in Example 1 (3), the rubber-like copolymer latex (A-1) to be used is mixed with the above rubber-like weight. Except having changed to the coalesced latex (A-4), the weight average particle diameter was 0.27 μm and the solid content was 3 in the same manner as in Example 1 (3).
9.5% of an enlarged rubbery polymer latex (C-
4) was obtained.

(3) Production of Graft Copolymer (D-4) In the production of the graft copolymer (D-1) described in Example 1 (4), the enlarged rubbery copolymer latex ( The graft copolymer (D) was prepared in the same manner as in Example 1 (4) except that C-1) was changed to the above-mentioned enlarged rubber-like polymer latex (C-4) and the amount of water was adjusted in terms of solid content.
-4) was obtained. The polymerization conversion was 97%.

Next, the graft copolymer (D-4)
Forty parts and 60 parts of the AS resin of Example 1 were blended using a twin-screw extruder in the same manner as in Example 1, pelletized, and a test piece was prepared by injection molding to evaluate physical properties. Table 2 shows the obtained results.

Comparative Example 2 (1) Production of Rubbery Polymer Latex (A-5) The rubbery copolymer latex (A) described in Example 1 (1)
In the production of -1), the same polymerization as in Example 1 (1) was carried out except that the monomer used was only 100 parts of 1,3-butadiene, and the polymerization temperature was changed to 60 ° C. A rubbery polymer latex (A-5) having a content of 40.1%, a polymerization conversion of 97%, a weight average particle diameter of 0.07 μm and a pH of 10.0 was obtained.

(2) Enlarged rubbery polymer latex (C
Production of -5) In the production of the enlarged rubber-like copolymer latex (C-1) described in Example 1 (3), the rubber-like copolymer latex (A-1) used is mixed with the above-described enlarged rubber. Extruded in the same manner as in Example 1 (3) except that the polymerized polymer latex (A-5) was used, and the weight-average particle diameter was 0.27 μm and the solid content was 39.4%. A polymer latex (C-5) was obtained.

(3) Production of Graft Copolymer (D-5) In the production of the graft copolymer (D-1) described in Example 1 (4), an enlarged rubbery copolymer latex ( Example 1 except that C-1) was changed to the above-mentioned enlarged rubbery polymer (C-5) and the amount of water was adjusted in terms of solid content.
A graft copolymer (D-5) was obtained in the same manner as (4). The polymerization conversion was 97%.

Next, the graft copolymer (D-5)
Forty parts and 60 parts of the AS resin of Example 1 were blended using a twin-screw extruder in the same manner as in Example 1, pelletized, and a test piece was prepared by injection molding to evaluate physical properties. Table 2 shows the obtained results.

Comparative Example 3 (1) Production of Rubbery Copolymer Latex (A-6) The procedure of Example 3 (3) was repeated except that the polymerization temperature after the completion of the dropwise addition of the monomer was changed to 72 ° C. Polymerization was performed in the same manner. After 6 hours, the remaining 1,3-butadiene was removed, and the solid content was 40.1%.
A rubbery copolymer latex (A-6) having a polymerization conversion of 97%, a weight average particle diameter of 0.06 μm and a pH of 10.0 was obtained.

(2) Production of enlarged rubber-like copolymer latex (C-6) Rubber used in production of enlarged rubber-like copolymer latex (C-1) described in Example 1 (3) In the same manner as in Example 1 (3), except that the rubber-like copolymer latex (A-1) was changed to the rubber-like polymer latex (A-6), the weight average particle diameter was 0.27 μm and the solid was 3 minutes
An enlarged rubbery polymer latex (C-6) of 9.4% was obtained.

(3) Production of Graft Copolymer (D-6) In the production of the graft copolymer (D-1) described in Example 1 (4), the enlarged rubbery copolymer latex ( The graft copolymer was prepared in the same manner as in Example 1 (4), except that C-1) was changed to the above-mentioned enlarged rubbery copolymer latex (C-6) and the amount of water was adjusted in terms of solid content. (D-6) was obtained. The polymerization conversion was 97%.

Next, the graft copolymer (D-6)
Forty parts and 60 parts of the AS resin of Example 1 were blended using a twin-screw extruder in the same manner as in Example 1, pelletized, and a test piece was prepared by injection molding to evaluate physical properties. Table 2 shows the obtained results.

Comparative Example 4 (1) Production of Rubbery Copolymer Latex (A-7) The rubbery polymer latex (A-7) described in Example 1 (1)
In the production of 1), the polymerization was continued without using mercaptan when the polymerization conversion reached 40%, and 1,3-butadiene was removed after 7 hours.
A rubbery copolymer latex (A-7) having a solid content of 40.1%, a polymerization conversion of 97%, a weight average particle diameter of 0.07 μm and a pH of 10.0 was obtained in the same manner as in Obtained.

(2) Production of Enlarged Rubbery Copolymer Latex (C-7) Rubber used in production of enlarged rubbery copolymer latex (C-1) described in Example 1 (3) Except that the rubber-like copolymer latex (A-1) was changed to the above-mentioned rubber-like polymer latex (A-7), the weight average particle diameter was 0.27 μm and the solid was as in Example 1 (3). 3 minutes
An enlarged rubbery copolymer latex (C-7) of 9.4% was obtained.

(3) Production of Graft Copolymer (D-7) In the production of the graft copolymer (D-1) described in Example 1 (4), the enlarged rubbery copolymer latex ( The graft copolymer was prepared in the same manner as in Example 1 (4) except that C-1) was changed to the above-mentioned enlarged rubbery copolymer latex (C-7) and the amount of water was adjusted in terms of solid content. (D-7) was obtained. The polymerization conversion was 97%.

Next, the graft copolymer (D-5)
Forty parts and 60 parts of the AS resin of Example 1 were blended using a twin-screw extruder in the same manner as in Example 1, pelletized, and a test piece was prepared by injection molding to evaluate physical properties. Table 2 shows the obtained results.

Comparative Example 5 (1) Production of Rubbery Copolymer Latex (A-8) The rubbery copolymer latex (A) described in Example 1 (1)
In the production of -1), the same as Example 1 (1) except that the amount of n-dodecyl mercaptan added at the time when the polymerization conversion reached 40% was changed from 0.3 parts to 2.0 parts. , A solid content of 40.1% and a polymerization conversion of 97
%, A weight average particle diameter of 0.07 μm and a pH of 10.
Thus, a rubbery copolymer latex (A-8) was obtained.

(2) Production of enlarged rubber-like copolymer latex (C-8) Rubber used in production of enlarged rubber-like copolymer latex (C-1) described in Example 1 (3) In the same manner as in Example 1 (3), except that the rubber-like copolymer latex (A-1) was changed to the rubber-like polymer latex (A-8), the weight average particle diameter was 0.27 μm and the solid 3 minutes
An enlarged rubbery polymer latex (C-8) of 9.4% was obtained.

(3) Production of Graft Copolymer (D-8) In the production of the graft copolymer (D-1) described in Example 1 (4), the enlarged rubbery copolymer latex ( The graft copolymer was prepared in the same manner as in Example 1 (4) except that C-1) was changed to the above-mentioned enlarged rubbery copolymer latex (C-8) and the amount of water was adjusted in terms of solid content. (D-8) was obtained. The polymerization conversion was 97%.

Next, the graft copolymer (D-8)
Forty parts and 60 parts of the AS resin of Example 1 were blended using a twin-screw extruder in the same manner as in Example 1, pelletized, and a test piece was prepared by injection molding to evaluate physical properties. Table 2 shows the obtained results.

Comparative Example 6 (1) Preparation of Rubbery Polymer Latex (A-9) The rubbery copolymer latex (A) described in Example 2 (1)
In the production of -2), except that the intermediate addition of n-dodecyl mercaptan was changed before the polymerization was started,
The same polymerization as in Example 2 (1) was carried out, and the solid content was 40.1.
%, Polymerization conversion rate is 97%, weight average particle diameter is 0.07μ
A rubbery copolymer latex (A-9) having m and pH of 10.0 was obtained.

(2) Production of enlarged rubber-like copolymer latex (C-9) Rubber used in production of enlarged rubber-like copolymer latex (C-1) described in Example 1 (3) Except that the rubbery copolymer latex (A-1) was changed to the above rubbery copolymer latex (A-9), the weight average particle diameter was 0.27 μm and the same as in Example 1 (3). An enlarged rubbery copolymer latex (C-9) having a solid content of 39.4% was obtained.

(3) Production of Graft Copolymer (D-9) In the production of the graft copolymer (D-1) described in Example 1 (4), the enlarged rubbery copolymer latex ( The graft copolymer was prepared in the same manner as in Example 1 (4), except that C-1) was changed to the above-mentioned enlarged rubbery copolymer latex (C-9) and the amount of water was adjusted in terms of solid content. (D-9) was obtained. The polymerization conversion was 97%.

Next, the graft copolymer (D-9)
Forty parts and 60 parts of the AS resin of Example 1 were blended using a twin-screw extruder in the same manner as in Example 1, pelletized, and a test piece was prepared by injection molding to evaluate physical properties. Table 2 shows the obtained results.

Comparative Example 7 (1) Production of Rubbery Copolymer Latex (A-10) The rubbery copolymer latex (A) described in Example 2 (1)
In the production of -2), the polymerization conversion rate during the addition was 95%.
The polymerization was carried out in the same manner as in Example 2 (1) except that 0.2 parts of n-dodecyl mercaptan was added at the time point when the solid content was reached, the solid content was 40.1%, the polymerization conversion was 97%, and the weight average particles were A rubbery copolymer latex (A-10) having a diameter of 0.07 μm and a pH of 10.0 was obtained.

(2) Production of enlarged rubber-like copolymer latex (C-10) Rubber used in production of enlarged rubber-like copolymer latex (C-1) described in Example 1 (3) Except that the rubber-like copolymer latex (A-1) was changed to the above-mentioned rubber-like copolymer latex (A-10), the weight average particle diameter was 0.27 μm and the same as in Example 1 (3). An enlarged rubbery copolymer latex (C-10) having a solid content of 39.4% was obtained.

(3) Production of Graft Copolymer (D-10) In the production of the graft copolymer (D-1) described in Example 1 (4), the enlarged rubbery copolymer latex ( The graft copolymer was prepared in the same manner as in Example 1 (4) except that C-1) was changed to the above-mentioned enlarged rubbery copolymer latex (C-10) and the amount of water was adjusted in terms of solid content. (D-10) was obtained. The polymerization conversion was 97%.

Next, the graft copolymer (D-1)
0) 40 parts and 60 parts of the AS resin of Example 1
After blending and pelletizing using a twin-screw extruder in the same manner as described above, a test piece was prepared by injection molding to evaluate the physical properties. Table 2 shows the obtained results.

[0097]

[Table 1]

[0098]

[Table 2]

[Examples 4 to 15] The graft copolymer (D-1) obtained in Example 1, the AS copolymer used in Example 1, and a polycarbonate resin (Nova, manufactured by Mitsubishi Engineering-Plastics Corporation) Rex 7022PJ),
Polyester resin (polytetramethylene terephthalate having an intrinsic viscosity [η] of 1.05), glass fiber (ECSO3T-34, manufactured by NEC Corporation), carbon fiber (Pyrofil TR-06N, manufactured by Mitsubishi Rayon Co., Ltd.) and Talc (Microtalc MP, manufactured by Pfizer MSP)
10-52) were blended at the ratios shown in Table 3 and pelletized using a twin-screw extruder, and test pieces were prepared with an injection molding machine to evaluate physical properties. Table 3 shows the results.

[0100]

[Table 3]

[0101]

As is evident from the results shown in Examples 1 to 15 and Comparative Examples 1 to 7, the rubbery copolymer latex obtained by the present invention is excellent in rot resistance. A thermoplastic resin comprising a graft copolymer obtained by using a coalesced latex has excellent performance as an impact resistance modifier. Further, according to the method of the present invention, the polymerization time of the rubber-like copolymer latex can be shortened without lowering the impact resistance-improving ability, and the productivity can be improved.

Claims (2)

[Claims] 1. A redox initiator comprising a monomer (50 parts by weight in total) consisting of 50 to 99 parts by weight of a diene monomer and 1 to 50 parts by weight of an aromatic vinyl monomer copolymerizable therewith. A polymerization initiator using a formaldehyde sulfoxylate salt as the secondary reducing agent of the system is used to obtain a polymerization temperature of 72.
A method of producing a rubber-like copolymer latex, characterized in that the polymerization is carried out at a temperature lower than 0 ° C., and when the polymerization conversion reaches 10 to 70%, 0.01 to 1.0 part by weight of a mercaptan compound is added and polymerized. . 2. The rubbery copolymer latex obtained in claim 1 as it is, or the particle size of the rubbery copolymer latex is enlarged, and a vinyl cyanide monomer and an aromatic A thermoplastic resin comprising a graft copolymer obtained by polymerizing a monomer mixture containing a vinyl monomer as an essential component.