JPH061815A - Production of graft copolymer - Google Patents

Abstract

PURPOSE:To obtain the title copolymer giving a molding having an excellent balance among physical properties, etc., by mixing specific rubber latexes, enlarging the rubber particles in the mixed latex, and emulsion-polymerizing a given monomer mixture in the presence of the resulting latex. CONSTITUTION:20-95 pts.wt., on solid basis, rubber latex obtained by emulsion- polymerizing a mixture of at least 50wt.% conjugated diene monomer and up to 50wt.% ethylenic monomer copolymerizable therewith is mixed with 5-80 pts.wt., on solid basis, rubber latex obtained by emulsion-polymerizing a mixture of 70-100wt.% acrylic ester of a 2-12C monohydric alcohol, 0-27wt.% vinyl monomer copolymerizable therewith, and 0-3wt.% polyfunctional vinyl monomer. The rubber particles in the mixed latex are enlarged to a given average particle diameter. 90-30 pts.wt. mixture consisting mainly of 10-50 (exclusive of 50)wt.% vinyl cyanide monomer and 50-90 (exclusive of 50)wt.% aromatic vinyl monomer is then emulsion-polymerized in the presence of 10-70 pts.wt. the resulting latex on solid basis.

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION

[0002]

[0001]

[0003]

FIELD OF THE INVENTION The present invention relates to a method for producing a graft copolymer. More specifically, the present invention is a method in which a conjugated diene rubber latex and an acrylic ester rubber latex produced by emulsion polymerization are mixed, the particle size is enlarged, and then a small proportion of a vinyl cyanide monomer and a high proportion of an aromatic monomer are used. The present invention relates to a method for producing a graft copolymer by which a monomer mixture having a vinyl monomer is graft-reacted to obtain a molded article having an excellent balance of physical properties and excellent chemical resistance.

[0004]

[0002]

[0005]

2. Description of the Related Art Graft copolymerization is well known as one of methods for obtaining an impact resistant resin. For example, a composition in which rubber elastic particles are dispersed in a matrix composed of a styrene-acrylonitrile copolymer or the like. The rubber-modified resin having the above has excellent impact resistance and is easy to mold, and thus is widely used as a material for electric appliances, automobiles and other parts, casings and the like. In this case, as a rubber elastic body,
Conjugated diene-based polymers such as polybutadiene, polyisoprene, and styrene-butadiene copolymer (SBR) have been widely adopted.

[0006]

Such a graft copolymer resin, for example,
An ABS resin, which is typically a copolymer of acrylonitrile, butadiene, and styrene (specifically, for example, emulsion polymerization of acrylonitrile and styrene in polybutadiene latex), contains acrylonitrile as a matrix component. Therefore, it has excellent chemical resistance, but in recent years, with further expansion of its applications and applications, further improvement in chemical resistance has been demanded.

For this reason, so-called high nitrile resins having an increased acrylonitrile content in the matrix have been developed (for example, Japanese Patent Publication No. 46-2500).
No. 5, JP-A-47-5594, etc.).

[0008]

[0004]

[0009]

However, with an increase in the content of acrylonitrile, the molding conditions of the high nitrile resin are limited, and the productivity is deteriorated.
The yellowness has become stronger, causing problems such as coloring.

[Summary of Invention]

[0011]

[0005]

[0012]

DISCLOSURE OF THE INVENTION The present invention is intended to solve the above-mentioned problems, and a graft copolymer resin composition satisfying a specific condition is produced by a specific production method, that is, an emulsion polymerization. A rubber latex and an acrylic ester rubber latex are mixed, the particle size is enlarged, and then a monomer mixture consisting of a small proportion of vinyl cyanide monomer and a high proportion of aromatic vinyl monomer is emulsion polymerized. , By trying to achieve this end.

[0013]

<Summary> That is, the method for producing a graft copolymer according to the present invention is characterized by comprising the following steps (I), (II) and (III).

Step (I): Obtain the following mixture of latex of component (A) and latex of component (B) (however, the weight of both rubbers is 100 parts by weight in total).
Mixed rubber latex preparation step, (A) Conjugated diene rubber latex obtained by emulsion polymerization of a mixture of 50% by weight or more of a conjugated diene monomer and 50% by weight or less of an ethylenically unsaturated monomer copolymerizable therewith 20 as solid content conversion
95 parts by weight, (B) 70 to 100% by weight of an ester compound of a monohydric alcohol having 2 to 12 carbon atoms and acrylic acid,
0 to 50 vinyl monomers copolymerizable with the acrylic ester
5 to 80 parts by weight of an acrylic acid ester-based rubber latex obtained by emulsion polymerization of a monomer mixture of 27% by weight and a polyfunctional vinyl monomer of 0 to 3% by weight, as a solid content, Step (II): Adjusting the average particle diameter of the mixed rubber latex so as to be 0.15 to 0.65 μm, a particle size enlargement step, step (III): 10 to 70 weight in terms of solid content of the mixed rubber latex having the expanded particle diameter. Monomer mixture 9 consisting mainly of 10 to less than 50% by weight of vinyl cyanide monomer and 90 to more than 50% by weight of aromatic vinyl monomer in the presence of parts.
Polymerization step of emulsion polymerizing 0 to 30 parts by weight (however, the total weight of the mixed rubber latex solid content and the monomer mixture is 100 parts by weight).

[0015]

<Effect> The graft copolymer resin composition obtained by the method for producing a graft copolymer resin according to the present invention has good chemical resistance. In addition, the impact resistance and fluidity are also good, and the balance of physical properties is excellent.

[0016]

[Detailed Description of the Invention] The method for producing the graft copolymer according to the present invention comprises steps (I) to (III).
Here, "consisting of" means that, in addition to consisting of only the listed steps, an auxiliary step, for example, a latex concentration adjusting step, may be included within a range not impairing the gist of the present invention. To do.

The "graft copolymer" to be produced by the method of the present invention is a polymer obtained by polymerizing a monomer to give "branches" in the presence of a polymer which can serve as a trunk. An ideal graft copolymer consisting only of a trunk polymer and a branch polymer grafted with the trunk polymer, and a non-graft copolymer consisting of a trunk polymer and a branching polymer not grafted with the trunk polymer, Including polymers of any composition in between.

[0018]

<Step (I)> Step (I) is a step of preparing a mixture of two kinds of rubber latex.

(1) Conjugated diene rubber latex In the present invention, the conjugated diene rubber is obtained by polymerizing 50% by weight or more of a conjugated diene monomer and 50% by weight or less of a comonomer by an emulsion polymerization method. It is a synthetic rubber latex.

Examples of the conjugated diene monomer which should give the conjugated diene rubber include 1,3-butadiene, isoprene and chloroprene. From the viewpoint of easy availability and polymerizability, 1,3-butadiene and isoprene are preferable. These may be used alone or in combination.

[0021]

Examples of the comonomer include unsaturated nitriles, unsaturated carboxylic acid esters, aromatic vinyls, vinyl pyridines and the like. These may be used alone or in combination within a group or between groups. Specific examples include (a) unsaturated nitriles such as acrylonitrile, methacrylonitrile, α-chloroacrylonitrile, and preferably acrylonitrile, methacrylonitrile, acrylonitrile, and (b) unsaturated carboxylic acid esters such as acryl. Acid or lower alkyl ester of methacrylic acid such as methyl, ethyl, propyl and butyl, preferably methyl acrylate, ethyl acrylate,
Methyl methacrylate, ethyl methacrylate, (c) aromatic vinyl, such as styrene and / or side chain-substituted styrene (substituent is lower alkyl, halogen atom, etc.) or unsubstituted styrene, such as styrene, α-methylstyrene, vinyl Toluenes, vinylxylenes and the like, preferably styrene, (di) vinyliripyridine, for example, 4-vinylpyridine are mentioned.

Preferred as the conjugated diene rubber in the present invention are polybutadiene, polyisoprene, polychloroprene, poly (butadiene-styrene) and poly (butadiene-acrylonitrile).

The rubber content in the latex is 10 to 60.
It is about% by weight.

[0024]

(2) Acrylate ester-based rubber latex In the present invention, the acrylate ester-based rubber means 70 to 100% by weight of an ester compound of a monohydric alcohol having 2 to 12 carbon atoms and acrylic acid, and the acrylate ester. A latex obtained by emulsion-polymerizing a monomer mixture of 0 to 27% by weight of a copolymerizable vinyl monomer and 0 to 3% by weight of a polyfunctional vinyl monomer. This acrylic ester rubber is a synthetic rubber latex obtained by an emulsion polymerization method.

As the acrylic ester used for producing the acrylic ester rubber, an ester of acrylic acid and a monohydric alcohol having 2 to 12 carbon atoms, preferably 4 to 8 carbon atoms is suitable. Specifically, butyl acrylate, 2-ethylhexyl acrylate and the like are preferable. When the carbon number is out of the above range, sufficient rubber elasticity cannot be obtained, which is not preferable. These esters may be used alone or in combination of two or more.

[0026]

The vinyl monomer copolymerizable with acrylic acid esters is preferably one having a function of improving and improving the properties of the acrylic rubber obtained by copolymerization as a reinforcing rubber and the graft polymerization reactivity. Specifically, those described above as the comonomer of the conjugated diene rubber, for example, acrylonitrile, methacrylonitrile, styrene, α-methylstyrene, p-vinyltoluene and other vinyltoluenes, alkyl methacrylate, 2-chloroethyl vinyl ether, Monochlorovinyl acetate, methyl acrylate, methoxyethyl acrylate and the like can be mentioned.

The polyfunctional vinyl monomer having a plurality of ethylenically unsaturated bonds, divinylbenzene, ethylene glycol dimethacrylate, diallylmaleate, triallyl cyanurate, triallyl isocyanurate, diallyl phthalate, Examples include trimethylolpropane triacrylate and allyl methacrylate.

[0028]

By using these polyfunctional vinyl monomers, intermolecular crosslinking of the acrylic ester copolymer,
Grafting with the matrix is facilitated, and the impact resistance of the composition involved in this reaction is improved.

In the present invention, the acrylic ester rubber is preferably 70 to 99.9, for example, a mixture of butyl acrylate, acrylonitrile and allyl methacrylate.
It is a copolymer obtained by emulsion polymerization in the range of 2: 0 to 27: 0.08 to 3 (weight ratio, that is, weight%).

The rubber content in the latex is 10 to 60.
It is about% by weight.

[0031]

(3) Mixing of latex The step (I) is a step of mixing the above-mentioned two kinds of rubber latexes to obtain a mixed rubber latex.

The mixture of both latices can be carried out by a conventional method.

The rubber amount of the mixed rubber latex is 20 to 95 parts by weight of the conjugated diene rubber, preferably 20 to 80 parts by weight, 80 to 5 parts by weight of the acrylate ester rubber, preferably 80 to 20 parts by weight (however, The total amount of both is 100
Parts by weight). The amount of conjugated diene rubber is 20
If it is less than 1 part by weight, "branch" in the subsequent graft copolymerization step
When the grafting of the polymer is insufficient and the physical properties of the resulting composition tend to deteriorate, on the other hand, when the amount of the acrylate rubber is less than 5 parts by weight, the meaning of using it is diminished. The chemical resistance of the graft copolymer is reduced.

The rubber content in the mixed rubber latex is also 1
The amount is 0 to 60% by weight, preferably 20 to 50% by weight.

[0035]

<Step (II)> Step (II) is the step (I)
This is a step of enlarging the particle size of the rubber particles of the mixed rubber latex obtained in.

It should be noted that this step is a step of "adjusting" the average particle diameter of the rubber to a specific value, and one or both of the rubber latexes in step (I) already have a particle diameter in this specific range. If so, the particle size enlargement operation is virtually unnecessary. Even if this process is called a "particle size enlargement process", the operational requirement is not to be "particle size enlargement" but to be "adjustment" of the particle size. However, even in that case, it is preferable to perform the particle size enlargement operation so as to obtain the particles in which the conjugated diene rubber and the acrylate rubber are mixed.

[0037]

In the present invention, it is necessary to perform a particle size enlargement operation on the latex of the mixture of both rubbers (the meaning of "necessary" is as described above). Enlargement of the particle size of rubber latex means that particles with a small particle size agglomerate into particles with an apparently large particle size, rather than individual particles having a large particle size. Therefore, if such enlarged particles are composed of agglomerates of the unit particles of both rubbers, it is easier to realize more homogeneity than the produced graft copolymer. That is, by mixing a conjugated diene rubber and an acrylic ester rubber to increase the particle size, the respective rubbers are mixed uniformly, and a graft copolymer having a better chemical resistance and a better physical property balance is obtained. Obtainable.

[0038]

In the method of the present invention, the mixture of the conjugated diene rubber and the acrylic ester rubber is used to have a particle size of 0.15 to 0.65 μm, preferably 0.20 to 0.
The particle size is enlarged to 50 μm. When the rubber particle size is, for example, a small particle size of less than 0.15 μm, the moldability (fluidity) when molding the final product, that is, the molding property (flowability), and the more important impact resistance, decrease However, this causes deterioration of the rubber addition efficiency. On the other hand, if the rubber particle size is, for example, a large particle size exceeding 0.65 μm, the emulsion is depolymerized, which causes destabilization of the latex and causes problems such as an increase in the amount of scale during the polymerization, which is not preferable. .

[0039]

The particle size enlargement is carried out by a known method, for example, a method in which the latex is once frozen and then redissolved, a method in which a mineral acid, an organic acid or the like is added to the latex to temporarily lower the latex pH, A method of applying shearing force to latex (Japanese Patent Laid-Open No. 54-133588, Japanese Patent Laid-Open No. 59-20).
No. 2211). In particular, the method of adding phosphoric acid or acetic anhydride to the latex is preferable because the particle size can be easily adjusted.

[0040]

The particle size needs to fall within the above range, but the rubber particle size distribution does not need to be so-called monomodal in which the particle size distribution curve has a single peak, but a plurality of peaks, for example, two. It may be bimodal with two mountains. In the case of bimodal particle size distribution, the weight average rubber particle size of both latexes is 0.15 to 0.6.
It may be in the range of 5 μm.

The average particle diameter of the rubber particles in the latex is the weight average particle diameter obtained by measuring the light scattering of the diluted latex aqueous solution with laser light.

[0042]

<Step (III)> In the step (III), in the latex of the rubber with enlarged particle size obtained as described above,
This is a polymerization step in which the monomers to which the "branched" polymer is to be added, namely the monomer mixture mainly consisting of vinyl cyanide monomer and aromatic vinyl monomer, are emulsion polymerized.

[0043]

(A) Monomer mixture Specific examples of the vinyl cyanide monomer in the present invention include acrylonitrile, methacrylonitrile, α-chloroacrylonitrile and the like. These may be one kind or a mixture of two or more kinds.

The proportion of vinyl cyanide monomer in the monomer mixture must be 10 to less than 50% by weight. If it is less than 10% by weight, the desired physical properties such as chemical resistance cannot be imparted to the graft copolymer, which is not preferable. Particularly preferably, it is 20 to 45% by weight or more. On the other hand, if it is less than 50% by weight, properties of the graft copolymer such as moldability and coloring property upon heating are deteriorated, which is not preferable.

[0045]

Specific examples of the aromatic vinyl monomer in the present invention include α-alkyl (preferably lower) such as styrene and α-methylstyrene, and nucleus-substituted alkyl (preferably lower) such as styrene and p-methylstyrene. Examples thereof include styrene, halogenated styrene, vinylnaphthalene and the like.
These may be one kind or a mixture of two or more kinds.

On the other hand, the ratio of the aromatic vinyl monomer in the monomer mixture should be 90 to 50% by weight. When this ratio is out of the above range, the properties of the resulting graft copolymer are deteriorated in properties such as desired chemical resistance, gas barrier property, molding processability, and coloring property upon heating, which is not preferable.

[0047]

The monomer mixture in step (III) consists mainly of the specified amounts of the two essential monomers mentioned above, so that this monomer mixture is in addition to the above two components copolymerizable with these two components. It means that a vinyl monomer, preferably a monomer which gives a resinous polymer, may be contained in a small amount, for example, up to 10% by weight of the total amount of the two essential monomers. Examples of such a third monomer include methacrylic acid lower alkyl ester.

In step (III), the monomers are called "monomer mixture", but this means that at least two kinds of monomers are used in combination. Even if it means that the monomer is always introduced into the graft copolymerization step in the form of a mixture, the amount ratio of both monomers when introducing into the graft copolymerization step is always fixed to a constant value within the above range. It doesn't mean that.

[0049]

(B) Emulsion Polymerization / Graft Copolymerization In the emulsion polymerization, the ratio of the “stem” polymer to the “branch” polymer monomer is 10 to 70 parts by weight, preferably 20 to 60 parts by weight.
Parts by weight, the latter 90 to 30 parts by weight, preferably 80 to 4
0 parts by weight (the total of both is 100 parts by weight).

When the ratio of the conjugated diene rubber and the acrylic ester rubber mixture is less than 10 parts by weight, the impact resistance of the resulting graft copolymer is lowered and a molded product having the desired physical properties is obtained. However, it is not preferable for use as an impact resistance-imparting agent because the effect is reduced.
If it exceeds 70 parts by weight, the graft ratio of the resulting graft copolymer becomes small, and the dispersibility of the rubber particles and the rubber efficiency, that is, the impact resistance and the like decrease, which is not preferable.

The emulsion polymerization operation itself is the same as the conventional method.

[0052]

In the preferred method of the present invention, the monomers are separately or mixed at a temperature of about 0 to 100 ° C. in a state where oxygen is removed, and if necessary, components other than the monomer such as an emulsifier, Dispersing agents, polymerization initiators, molecular weight regulators or chain transfer agents, pH regulators, etc. are fed to the polymerization system as they are or in an emulsified state, either temporarily or batchwise or continuously, for polymerization. That is. Polymerization initiators (or catalysts) that can be used include persulfuric acid, peracetic acid, perphthalic acid and other peracid catalysts, potassium persulfate and other peracid catalysts, hydrogen peroxide, benzoyl peroxide, chlorobenzoyl peroxide. , Naphthyl peroxide, acetyl peroxide, benzoylacetyl peroxide, lauryl peroxide, di-t-peroxide
There are peroxide catalysts such as butyl, dicumyl peroxide, t-butyl peroxide and sodium peroxide, alkyl hydroperoxides such as t-butyl hydroperoxide, and azo catalysts such as azobisbutyronitrile. Or a mixture of two or more kinds can be used. These can also be used as a redox catalyst in combination with a reducing agent.

[0053]

Examples of emulsifiers that can be used in the present invention include fatty acid salts, alkyl sulfate ester salts, alkyl benzene sulfonates, alkyl naphthalene sulfonates, alkyl sulfosuccinates, alkyl diphenyl ether disulfonates, alkyl phosphates and the like. .

The chain transfer agent which can be used in the present invention is not particularly limited, and examples thereof include n-octyl mercaptan and n.
-Dodecyl mercaptan, t-dodecyl mercaptan,
Etc. or terpinolene, α-methylstyrene linear dimer, etc. are used.

The polymerization product is obtained in the form of a latex, and the polymer is coagulated by a conventionally known method, for example, an agglomeration method using an electrolyte or a solvent, a freezing method, etc., and further washed with water and dried to obtain the polymer. After that, the molding material can be obtained by appropriately combining the steps of mixing, kneading, devolatilizing, pelletizing and the like.

It is also possible to add plasticizers, stabilizers, lubricants, dyes and pigments, fillers and the like during the polymerization or after the polymerization, if necessary.

[0057]

<Use of Graft Copolymer> The graft copolymer produced by the present invention is useful as a resin material excellent in impact resistance and the like as described above.
It is also useful as an impact resistance-imparting agent for a hard resin miscible with it. A typical example of a hard resin in the latter case is a resin formed from the monomer mixture used in step (III). A typical example of the mixture / blend of both is that of the rubber content achieved in step (III).

[0058]

[0028]

[0059]

EXAMPLES The following examples and comparative examples are intended to explain the present invention more specifically, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded.

In each of the following examples and comparative examples, the physical properties of the impact-resistant styrene resin were measured by the following methods.

(1) Izod impact strength Measured according to JIS K7110.

(2) Melt flow rate: Measured in accordance with JIS K7210 under the conditions of 220 ° C. and 10 kg, and indicated by the number of g flowing out for 10 minutes.

(3) Average Particle Size of Latex The average particle size of the latex was measured by "Nanosizer" manufactured by Coulter Co., USA.

(4) Chemical resistance The final compound was compression molded into a strip of 35 mm × 230 mm × 2 mm, and a test piece was bent into a bending form (a bending strain jig similar to a 1/4 elliptical jig (maximum strain value 1 0.0%)). Methanol was applied at a temperature of 23 ° C., and the presence or absence of crazes or cracks at a predetermined position of the bending foam after 17 hours was visually determined to calculate the critical strain value.

When the critical strain value is 0.6% or more, the chemical resistance is judged to be good.

[0066]

Example 1 (1) Production of Conjugated Diene Rubber (A) 2400 g of deionized water (hereinafter simply referred to as water) was added to a 5 LSUS autoclave, and higher fatty acid soap (sodium fatty acid having 18 carbon atoms as a main component). (Salt) 64.0 g and sodium hydroxide 1.2 g were charged, and the temperature was raised to 68 ° C. after purging with nitrogen. After charging 321 g of a monomer mixture consisting of 1440 g of 1,3-butadiene (BD), 160 g of styrene (St) and 4.8 g of t-dodecyl mercaptan, 2.16 g of potassium persulfate was added. An exotherm occurred within a few minutes, confirming the initiation of polymerization. One hour after the addition of potassium persulfate, continuous charging of 1284 g of the monomer mixture was started, and was completed at the time of 6 hours. After the addition of the monomer mixture was completed, the temperature was raised to 80 ° C. and the polymerization was further proceeded for 1 hour. Solid content concentration (rubber content in latex) 3
The average particle size was 9.5% and the average particle size was 0.08 μm.

[0067]

(2) Production of acrylic ester rubber (B) 2420 g of water and a higher fatty acid soap (sodium salt of fatty acid containing 18 carbon atoms as a main component) in a 5 L glass flask 3
2 g and 16 g of sodium hydrogen carbonate were charged, and the temperature was raised to 75 ° C. under a nitrogen stream. After adding 2.16 g of potassium persulfate, 5 minutes later, butyl acrylate (BA) 1
64 g of a monomer mixture consisting of 520 g, acrylonitrile (AN) 80 g, and methacrylic acid allyl ester (AMA) 8 g was charged. Fever occurs in a few minutes,
The initiation of polymerization was confirmed. Twenty minutes after the initial charging of the monomer mixture, continuous addition of the remaining monomer mixture was started, and the addition was completed at 3 hours and 20 minutes. At the time of 2 hours and 30 minutes, 0.24 g of potassium persulfate was added. After the addition of the monomer mixture was completed, the temperature was raised to 80 ° C., and the polymerization was further advanced at the same temperature for 1 hour. Solid content concentration (rubber content in latex)
The average particle size was 39.0% and the average particle size was 0.075 μm.

[0068]

(3) Enlargement of particle size of conjugated diene rubber / acrylic ester rubber mixture In a 5 L glass flask equipped with a stirrer, a reflux condenser, a thermometer, and an auxiliary agent addition device, the latex of the above (1) is added. 82
Charge 2.8 g (solid content 325 g), the latex of the above (2) 833.3 g (solid content 325 g), naphthalenesulfonic acid formalin condensate 0.33 g, and water 201 g,
The internal temperature was raised to 55 ° C. with stirring.

Subsequently, 7.8 g of acetic anhydride was added to 130 g of water and stirred with a homogenizer for 30 seconds, which was added to this flask at the same temperature.

Two minutes after the addition, 3.3 g of a naphthalenesulfonic acid condensate and 5.07 g of potassium hydroxide were added to 6 parts of water.
What was dissolved in 7.3 g was added to complete the particle size enlargement. Solid content concentration (rubber content in latex) 32.
The average particle size was 1% and the average particle size was 0.30 μm.

[0071]

(4) Production of graft copolymer 2025 g (solid content 650) of the latex of (3) above
g), 840 g of water, a stirring device, a reflux condenser, a thermometer,
Charge into a 5 L glass flask equipped with an auxiliary additive device,
The internal temperature was raised to 80 ° C. with stirring under a nitrogen stream.

Subsequently, an aqueous solution of potassium persulfate (I) (containing 1.56 g of potassium persulfate) was added to the flask.
100 g of acrylonitrile (AN) at the same temperature
The graft reaction was started by starting the continuous addition of a monomer mixture in which 195 g, 455 g of styrene, and 7.2 g of n-dodecyl mercaptan were mixed. 2 hours after the reaction 45
Until the end of the minute, the monomer mixture was added to the polymerization system at a constant addition rate.

From the start of the reaction, from 40 minutes to 2 hours and 45 minutes, 230 g of an aqueous solution of potassium persulfate (II) (containing 3.64 g of potassium persulfate) was added at a constant addition rate. , Continuously added to the polymerization system.

Two hours and 45 minutes after the start of the reaction,
After the addition of the monomer mixture was completed,
The reaction was continued for 5 minutes to complete the graft reaction.

The solid content concentration of the obtained latex was 35.
% By weight.

[0076]

After adding 15 g of the antioxidant, the obtained graft polymer latex was added to an aqueous magnesium sulfate solution heated to 95 ° C. with stirring to coagulate it. The coagulated product was washed with water and dried to obtain a white powdery rubber-containing resin composition.

The resin composition thus obtained was used to prepare a styrene-acrylonitrile copolymer (AN / St weight ratio 30/70, melt flow rate 25 g / 10 min (220 ° C., 10 kg )) And the content of the rubbery polymer in the entire composition to be 20% by weight by using an extruder, and after pelletizing, each test piece is prepared by injection molding to obtain each physical property. Was evaluated by the following method. The results are as shown in Table 1.

[0078]

Example 2 (1) Production of conjugated diene rubber (A) Same as described in Example 1 (1).

(2) Production of acrylic ester rubber (B).

Same as described in Example 1 (2).

(3) Particle Size Enlargement of Conjugated Diene Rubber / Acrylate Ester Rubber Mixture Same as described in Example 1 (3).

(4) Preparation of Graft Copolymer The procedure of Example (4) was the same as that of Example 1 (4), except that the composition of the monomer mixture was changed as follows. And

Monomer mixture Acrylonitrile 292.5 g Styrene 357.5 g n-Dodecyl mercaptan 5.2 g The latex obtained had a solid content of 34% by weight. The results of measuring the physical properties of the graft copolymer are shown in Table 1.

[0084]

Example 3 (1) Production of conjugated diene rubber (A) Same as described in Example 1 (1).

(2) Production of acrylic ester rubber (B).

Same as described in Example 1 (2).

(3) Particle Size Enlargement of Conjugated Diene Rubber / Acrylate Ester Rubber Mixture In the example described in Example 1 (3), the conjugated diene rubber (A) and the acrylate ester rubber (B) were mixed. The procedure was the same as in Example (3) except that the amounts were changed as shown below.

Conjugated diene rubber (A) 1234.2 g (solid content 487.5 g) Acrylic ester rubber (B) 416.7 g (solid content 162.5 g) The average particle size was 0.22 μm.

(4) Preparation of Graft Copolymer Same as described in Example 1 (4).

The results of measuring the physical properties of the graft copolymer are shown in Table 1.

[0091]

Example 4 (1) Production of Conjugated Diene Rubber (A) Same as described in Example 1 (1).

(2) Production of acrylic ester rubber (B).

Same as described in Example 1 (2).

(3) Particle Size Enlargement of Conjugated Diene Rubber / Acrylate Ester Rubber Mixture In the example described in Example 1 (3), the conjugated diene rubber (A) and the acrylate ester rubber (B) were mixed. The procedure was the same as in Example (3) except that the amounts were changed as shown below.

Conjugated diene rubber (A) 411.4 g (solid content 487.5 g) Acrylate ester rubber (B) 1250.0 g (solid content 487.5 g) The average particle size was 0.35 μm.

(4) Preparation of Graft Copolymer Same as described in Example 1 (4).

The results of measuring the physical properties of the graft copolymer are shown in Table 1.

[0098]

Example 5 (1) Production of Conjugated Diene Rubber (A) Same as described in Example 1 (1).

(2) Production of acrylic ester rubber (B).

Same as described in Example 1 (2).

(3) Particle Size Enlargement of Conjugated Diene Rubber / Acrylate Ester Rubber Mixture Same as described in Example 1 (3).

(4) Production of Graft Copolymer 2025 g (solid content 650) of the latex of (3) above is prepared.
g), 260 g of water, a stirring device, a reflux condenser, a thermometer,
Charge into a 5 L glass flask equipped with an auxiliary additive device,
The internal temperature was raised to 70 ° C. while stirring under a nitrogen stream.

[0103]

While increasing the temperature, 6.5 g of sodium pyrophosphate dissolved in 590 g of water, 3.3 g of dextrose and 0.065 g of ferrous sulfate are added. When the temperature reached 70 ° C., 0.49 g of cumene hydroperoxide, 4.9 g of rosin acid soap, 1.3 g of potassium hydroxide, and 104 g of water were added to this flask. After 15 minutes, continuous addition of a monomer mixture obtained by mixing 195 g of acrylonitrile, 455 g of styrene and 7.2 g of n-dodecyl mercaptan was started to start the graft reaction. The monomer mixture was added to the polymerization system at a constant addition rate from immediately after the reaction until after 2 hours and 45 minutes.

Further, from the start of the reaction, 40 minutes to 2 hours and 45 minutes later, 2.28 g of cumene hydroperoxide, 11.4 g of rosin acid soap and 256 g of water were added. After the addition was completed, the reaction was further continued for 15 minutes and cooled to complete the reaction.

[0105]

After adding 15 g of the antioxidant, the obtained graft polymer latex was added to an aqueous magnesium sulfate solution heated at 95 ° C. with stirring to coagulate. The coagulated product was washed with water and dried to obtain a white powdery rubber-containing resin composition.

The resin composition thus obtained was mixed with a styrene-acrylonitrile copolymer (AN / St weight ratio 30/70, melt flow rate 20 g / 10 minutes (22
0 ° C., 10 Kg)) and the content of the rubbery polymer in the entire composition to be 20% by weight by using an extruder, and after pelletizing, each test piece was prepared by injection molding. Then, each physical property was evaluated. The results are as shown in Table 1.

[0107]

Example 6 (1) Production of Conjugated Diene Rubber (A) Same as described in Example 1 (1).

(2) Production of acrylic acid ester rubber (B).

Same as described in Example 1 (2).

(3) Particle Size Enlargement of Conjugated Diene Rubber / Acrylate Ester Rubber Mixture In the example described in Example 1 (3), the same example except that 5.2 g of phosphoric acid was used instead of acetic anhydride. The procedure was the same as in (3).

(4) Preparation of Graft Copolymer Same as described in Example 1 (4).

[0112]

Example 7 (1) Production of Conjugated Diene Rubber (A) Same as described in Example 1 (1).

(2) Production of acrylic ester rubber (B).

Same as described in Example 1 (2).

(3) Particle Size Enlargement of Conjugated Diene Rubber / Acrylate Ester Rubber Mixture In the example described in Example 1 (3), the average particle size was 0.5.
The procedure was the same as in Example (3), except that the amount of acetic anhydride was changed so as to be 0 μm.

(4) Preparation of Graft Copolymer Same as described in Example 1 (4).

[0117]

Comparative Example 1 (1) Production of Conjugated Diene Rubber (A) Same as described in Example 1 (1).

(2) Production of acrylic ester rubber (B).

Same as described in Example 1 (2).

(3) Particle Size Enlargement of Conjugated Diene Rubber / Acrylate Ester Rubber Mixture In the example described in Example 1 (3), the conjugated diene rubber (A) and the acrylate ester rubber (B) were mixed. The procedure was the same as in Example (3) except that the amounts were changed as shown below.

Conjugated diene rubber (A) 1645.6 g (solid content 650.5 g) Acrylic ester rubber (B) 0.0 g (solid content 0.0 g) The average particle size was 0.20 μm.

(4) Preparation of Graft Copolymer Same as described in Example 1 (4).

The results of measuring the physical properties of the graft copolymer are shown in Table 1.

[0124]

Comparative Example 2 (1) Production of Conjugated Diene Rubber (A) Same as described in Example 1 (1).

(2) Production of acrylic acid ester rubber (B).

Same as described in Example 1 (2).

(3) Particle Size Enlargement of Conjugated Diene Rubber / Acrylate Ester Rubber Mixture In the example described in Example 1 (3), the conjugated diene rubber (A) and the acrylate ester rubber (B) were mixed. The procedure was the same as in Example (3) except that the amounts were changed as shown below.

Conjugated diene rubber (A) 0.0 g (solid content 0.0 g) Acrylate ester rubber (B) 1666.7 g (solid content 650.0 g) The average particle size was 0.38 μm.

(4) Preparation of Graft Copolymer Same as described in Example 1 (4).

The results of measuring the physical properties of the graft copolymer are shown in Table 1.

[0131]

Comparative Example 3 (1) Production of Conjugated Diene Rubber (A) Same as described in Example 1 (1).

(2) Production of acrylic acid ester rubber (B).

Same as described in Example 1 (2).

(3) Particle Size Enlargement of Conjugated Diene Rubber / Acrylate Ester Rubber Mixture Same as described in Example 1 (3).

(4) Preparation of Graft Copolymer The same procedure as in Example (4) except that the composition of the monomer mixture in the example described in Example 1 (4) was changed as follows. And

Monomer mixture Acrylonitrile 390 g Styrene 260 g n-Dodecyl mercaptan 19.5 g The latex obtained had a solid content of 34% by weight. The results of measuring the physical properties of the graft copolymer are shown in Table 1.

[0137]

Comparative Example 4 (1) Production of Conjugated Diene Rubber (A) Same as described in Example 1 (1).

(2) Production of acrylic ester rubber (B).

Same as described in Example 1 (2).

(3) Particle Size Enlargement of Conjugated Diene Rubber / Acrylate Ester Rubber Mixture Same as described in Example 1 (3).

(4) Preparation of Graft Copolymer The procedure of Example (4) was the same as that of Example 1 (4) except that the composition of the monomer mixture was changed as follows. did.

Monomer mixture Acrylonitrile 32.5 g Styrene 617.5 g n-Dodecyl mercaptan 3.3 g The latex obtained had a solids content of 34% by weight. The results of measuring the physical properties of the graft copolymer are shown in Table 1.

[0143]

Comparative Example 5 (1) Production of Conjugated Diene Rubber (A) Same as described in Example 1 (1).

(2) Production of acrylic ester rubber (B).

Same as described in Example 1 (2).

(3) Particle Size Enlargement of Conjugated Diene Rubber / Acrylate Ester Rubber Mixture In the example described in Example 1 (3), the average particle size was 0.6.
The procedure was the same as in Example (3) except that the amount of acetic anhydride was changed so as to be 5 μm.

(4) Preparation of Graft Copolymer Same as described in Example 1 (4).

[0148]

Comparative Example 6 (1) Production of Conjugated Diene Rubber (A) Same as described in Example 1 (1).

(2) Production of acrylic acid ester rubber (B).

Same as described in Example 1 (2).

(3) Particle Size Enlargement of Conjugated Diene Rubber / Acrylate Ester Rubber Mixture In the example described in Example 1 (3), the average particle size was 0.1.
The procedure was the same as in Example (3), except that the amount of acetic anhydride was changed so as to be 0 μm.

(4) Preparation of Graft Copolymer Same as described in Example 1 (4).

[0153]

[0048]

[Table 1]

[0154]

As shown in Table 1, the graft copolymer resin composition which does not satisfy the conditions specified in the present invention has any physical properties, particularly chemical resistance and / or impact resistance and / or impact resistance of molded articles. The resin fluidity is unsatisfactory, in other words, the graft copolymer resin composition according to the present invention is particularly excellent in the chemical resistance and / or impact resistance of the molded article and / or the fluidity of the resin. It is clear that they have excellent physical property balance.

[0155]

[0050]

[0156]

The graft copolymer resin composition obtained by the method for producing a graft copolymer resin according to the present invention has good chemical resistance, impact resistance and fluidity, and has an excellent balance of physical properties. It has been described in the section of [Summary].

Claims (1)

[Claims] 1. A process for producing a graft copolymer, which comprises the following steps (I), (II) and (III). Step (I): A mixed rubber latex preparation step for obtaining a mixture of the latex of the following component (A) and the latex of the component (B) (however, the total weight of both rubbers is 100 parts by weight): (A) A conjugated diene rubber latex obtained by emulsion-polymerizing a mixture of 50% by weight or more of a conjugated diene monomer and 50% by weight or less of an ethylenically unsaturated monomer copolymerizable therewith is 20 as a solid content. To 95 parts by weight, (B) 70 to 100% by weight of an ester compound of a monohydric alcohol having 2 to 12 carbon atoms and acrylic acid, 0 to 27% by weight of a vinyl monomer copolymerizable with the acrylic ester,
And 5 to 80 parts by weight of an acrylic acid ester-based rubber latex obtained by emulsion polymerization of a monomer mixture of 0 to 3% by weight of a polyfunctional vinyl monomer as a solid content. Step (II): the above mixed rubber latex The particle size increasing step of adjusting the average particle size of 0.15 to 0.65 μm, and the step (III): in the presence of 10 to 70 parts by weight in terms of the solid content of the mixed rubber latex having the particle size expanded And a monomer mixture 9 mainly consisting of 10 to less than 50% by weight of vinyl cyanide monomer and 90 to more than 50% by weight of aromatic vinyl monomer.
Polymerization step of emulsion polymerizing 0 to 30 parts by weight (however, the total weight of the mixed rubber latex solid content and the monomer mixture is 100 parts by weight).