JPS6264814A - Production of copolymer - Google Patents

Abstract

PURPOSE:To produce a homogeneous aqueous emulsified copolymer dispersion excellent in stability, by radical-copolymerizing a macromonomer with a vinyl compound and/or a conjugated diene compound under specified conditions. CONSTITUTION:A stable aqueous emulsified dispersion of a graft copolymer is obtained by copolymerizing a macromonomer (A), e.g., a compound of formula I, II or III [wherein X is a styrene derivative unit, a (meth)acrylic acid derivative unit or the like, R is H or a 1-8 C alkyl and n is 10-10,000] previously emulsified in water with a vinyl compound and/or a conjugated diene compound (B) [e.g., styrene derivative or (meth)acrylic acid derivative] or an aqueous emulsified dispersion of compound B with the aid of a radical initiator. By selecting a polymerization process, a conversion or a monomer, it is also possible to obtain an aqueous emulsified dispersion of a partially crosslinked graft copolymer. This copolymer can be used as a paint modifier; dispersibility modifier for polymers, fillers, pigments, etc.; pressure-sensitive adhesive; antithrombotic medical material; etc.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for producing a copolymer, and more specifically, the present invention relates to a method for producing a copolymer, and more specifically, a method for producing a copolymer by radically copolymerizing a macromonomer with a vinyl compound and/or a conjugated diene compound under specific conditions. The present invention relates to a method for producing a uniform aqueous emulsion dispersion made of a copolymer and having excellent dispersion stability by polymerization.

[Conventional technology]

Conventionally, many methods have been proposed for producing a graft copolymer by copolymerizing a macromonomer and a vinyl compound or a conjugated diene compound. For example, A radically polymerizable functional group is introduced at the end of the polymer to form a macromonomer, and then the macromonomer thus obtained and a second monomer are radically copolymerized to form a graft copolymer. There is a manufacturing method (Japanese Unexamined Patent Publication No. 144086/1986, Japanese Patent Publication No. 4535/1983)
(See Publication No. 8 and Japanese Patent Publication No. 10996/1983).

Another method is to carry out radical polymerization with styrene, methyl methacrylate, etc. using thioglycolic acid as a chain transfer agent, and then react the resulting carboxyl group at the end of the polymer with, for example, glycidyl methacrylate.
A method has been proposed for producing a graft copolymer by synthesizing a macromonomer having a methacrylic group at the end of the polymer, and then radical copolymerizing the obtained macromonomer and a second monomer (especially Kosho 41-1
1224, JP-A-58-164656).

In the method for producing the graft copolymer obtained in (1) or (2), a solution polymerization method is generally adopted in which radical copolymerization is carried out in a solvent in which both the macromonomer and the second monomer are uniformly dissolved. In addition, a method is also known in which a copolymer is obtained by dissolving a macromonomer in a second monomer or the like and then performing suspension polymerization using a dispersant in the presence of a radical initiator.

[Problem that the invention seeks to solve]

However, with these copolymer production methods, a solution of the graft copolymer (solution polymerization method) or a bead-shaped graft copolymer with a large particle size (suspension polymerization method) can be obtained, but a graft copolymer with a small particle size can be obtained. It is not possible to obtain an aqueous emulsified dispersion.

On the other hand, aqueous emulsified dispersions with fine particle diameters are generally known as latex, and are used in impact modifiers such as ABS resins, paints, binders, paper processing materials, adhesives for automobile tires, fiber processing agents, construction materials, etc. It is an industrially very useful polymer that is used in waterproofing agents, waxes, and various industrial parts.

In order to obtain an aqueous emulsified dispersion in this way, the graft copolymer previously produced by the conventional technique as described above is converted into an aqueous emulsified dispersion by first dissolving the graft copolymer in a solvent and then adding It is possible to emulsify by adding an emulsifier (such as soap) and applying ultrasound or high shear force to form an aqueous emulsified dispersion.

However, the aqueous emulsified dispersion obtained in this way requires an emulsifying dispersion process, which increases the production cost, and the stability of the aqueous emulsified dispersion is poor.Furthermore, the partially crosslinked graft copolymer is It has drawbacks such as being unable to do so.

The present invention was made against the background of the above-mentioned conventional technical problems, and it is possible to efficiently graft copolymerize a macromonomer with a vinyl compound and/or a conjugated diene compound, and to create a copolymer that is homogeneous and has excellent dispersion stability. The object is to provide an aqueous emulsified dispersion.

[Means for solving problems]

That is, the present invention uses a macromonomer (A) that has been previously aqueous emulsified.
and a vinyl compound and/or a conjugated diene compound (B
) or an aqueous emulsified dispersion of the compound (B) using a radical initiator.

In the present invention, the weight average molecular weight of the macromonomer (A) is preferably i,ooo to 1.000,000, more preferably 3,000 to 50,000, and 1,0
If it is less than 00, the properties of the macromonomer will not be reflected in the properties of the graft copolymer when it is made into a graft copolymer, whereas if it is more than 1,000,000, the vinyl compound and/or conjugated diene compound (B) will be copolymerized. It is difficult to reflect the nature of

In addition, the macromonomer (A) has a radically polymerizable acrylic ester group, styryl group, vinyl acetyl group, aryl group, vinyl ketone group, maleic anhydride group, fumaric acid ester group, vinylalkylsilyl group, It has a terminal polymerizable functional group such as a propenyl group.

Specific examples of such macromonomers (A) include the following.

(X)llOC(!, -〇H2, (Here, R represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. The same applies hereinafter) (X), lCb H4CH= CHz, (X)l
l CH2COCH=CH2, (X) , lCHz
CH= CH2, (X) -CCH= CH2, (X), -CH2-C--COORCH-COOR
.

R CH=CH2 (X), -CH2-C H2 Here, X is a styrene derivative unit such as styrene, α-methylstyrene, p-methylstyrene, p-tert-butylstyrene; methyl methacrylate, butyl methacrylate, butyl (Meth)acrylic acid derivatives such as acrylate, ethyl acrylate, 2-ethylhexyl acrylate, polyfluoroacrylate, methacrylic acid, and acrylic acid; nitrile compound units such as acrylonitrile, α, α′-dicyanoethylene, and cyanoethyl acrylate; Olefin compound units such as vinyl acetate, vinyl chloride, ethylene fluoride, and isobutylene; ether compound units such as ethylene oxide and propylene oxide; and one or more conjugated diene compound units such as butadiene, isoprene, piperylene, and chloroprene. It is composed of 1,000 units, and n is 10.
~to, 000, preferably an integer from 30 to 500.

The macromonomer (A) can be obtained by, for example: (i) polymerizing at least one anionically polymerizable monomer in the presence of an anionic polymerization initiator to form a monofunctional sping polymer; React with a terminator containing a copolymerizable terminal group (Japanese Patent Publication No. 51-45358)
No. 1, Japanese Patent Publication No. 54-10996, etc.), or ■ ethylenically unsaturated monomers in the presence of an initiator and a chain transfer agent each containing only one identical functional group that is reactive in the condensation reaction. to form an addition polymer containing only one functional group and no unsaturated groups introduced, and then converting the terminal functional group in the polymer into an unsaturated group that is reactive in the addition polymerization. The unsaturated group is bonded to the terminal position of the polymer by a condensation reaction with a compound containing
It can be easily manufactured by a known method such as Japanese Patent No. 164,656).

In the present invention, it is necessary to previously aqueous emulsify the macromonomer (A) prior to graft copolymerization.

Macromonomer (A) is not substantially different from ordinary polymers except that a terminal polymerizable functional group is bonded to the terminal group, so unless the main chain has a hydrophilic repeating structural unit, it is generally It is insoluble in water. Therefore, even if the macromonomer (A) is aqueous emulsified, the macromonomer (A) in the micelles produced will not dissolve in water and transfer to the micelles of the compound (B). Since (B) is a monomer, it relatively easily dissolves or diffuses into the aqueous phase and reaches the micelles of macromonomer (A).

The present invention provides such a macromonomer (A) and a compound (B)
This method was developed based on the solubility behavior of macromonomer (A) in an aqueous medium, and it is essential to aqueous emulsify the macromonomer (A) before copolymerization.

When copolymerizing the macromonomer (A) and the compound (B), even if the macromonomer (A) and the compound (B) are simultaneously aqueous emulsified, the emulsification efficiency of the macromonomer (A) is poor, resulting in fine, uniform particles. It is difficult to obtain a copolymer aqueous emulsion dispersion, and if the macromonomer (A) is subjected to graft copolymerization without aqueous emulsification, it will essentially result in suspension polymerization, making it difficult to obtain an aqueous emulsion dispersion. Can not.

Prior to graft copolymerization, by aqueous emulsifying the macromonomer (A) in advance, the macromonomer (A), which is insoluble or extremely sparingly soluble in water, forms fine micelles, into which the compound (B) or the aqueous emulsion is added. When the dispersion is added, the compound (B), which is highly concentrated, is dissolved or diffused in water (along with the radical initiator) and reaches the micelles of the macromonomer (A), where graft copolymerization begins. It is inferred that

Therefore, in the present invention, unless the macromonomer (A) is aqueous emulsified in advance, the object of the present invention cannot be achieved.

Here, the emulsifier for pre-aqueous emulsification of the macromonomer (A) to prepare an aqueous emulsified dispersion is not particularly limited as long as emulsification and dispersion is possible, and those commonly used as emulsifiers can be used. It will be done.

Specific examples of these emulsifiers include sodium dodecylhenzenesulfonate, sodium lauryl sulfate,
Examples include anionic emulsifiers such as sodium dialkyl sulfosuccinate, formalin condensate of naphthalene sulfonic acid, and polyoxyethylene nonylphenyl ether, polyethylene glycol monostearate,
It is also possible to use a nonionic surfactant such as sorbitan monostearate.

When such a macromonomer (A) is aqueous emulsified, the macromonomer (A) is usually added per 100 parts by weight of water.
is used in an amount of 0.1 to 50 parts by weight, preferably 1 to 20 parts by weight, and the emulsifier is used in an amount of 1 to 10 parts by weight, preferably 1 to 5 parts by weight.

In addition, the preparation of an aqueous emulsified dispersion of the macromonomer (A) is usually carried out by dissolving the macromonomer (A) in a solvent, adding the emulsifier, and then using a homomixer, a Manton Galarin homogenizer, or a super This is done by applying high shear forces such as sound waves.

Next, as the vinyl compound (B) used in the present invention, for example, styrene derivatives such as styrene, α-methylstyrene, p-methylstyrene, p-tert-butylstyrene; methyl methacrylate, butyl methacrylate, butyl acrylate, (Meth)acrylic acid derivatives such as ethyl acrylate, 2-ethylhexyl acrylate, polyfluoroacrylate, methacrylic acid, and acrylic acid; acrylonitrile, α,α′-dicyanoethylene,
Examples include nitrile compounds such as cyanoethyl acrylate; olefin compounds such as vinyl acetate, vinyl chloride, fluorinated ethylene, isobutylene, acrylamide, and 4-vinylpyridine; and conjugated diene compounds (
Examples of B) include butadiene, isoprene, piperylene, chloroprene, and the like.

These compounds (B) can be used alone or in combination of two or more.

In the present invention, as mentioned above, the macromonomer (A)
It is essential to aqueous emulsify prior to copolymerization, and compound (B) may or may not be aqueous emulsified in advance during copolymerization.

In the case of aqueous emulsification, it can be carried out in the same manner as the aqueous emulsification of the macromonomer (A), and usually water
1 to 50 parts by weight of compound (B), preferably 5 to 30 parts by weight, and 0.1 to 10 parts by weight, preferably 1 to 5 parts by weight of emulsifier are used per 0 parts by weight.

When copolymerizing the macromonomer (A) and the compound (B), the proportions of both can be determined at any rate depending on the purpose of use of the resulting copolymer;
Generally, the amount of compound (B) is preferably 1 to 5,000 parts by weight, and more preferably about 10 to 1,000 parts by weight of Z per 100 parts by weight of macromonomer (A).

The radical initiator used in copolymerization is not particularly limited as long as it is a compound suitable for conditions such as polymerization temperature, and examples thereof include benzoyl peroxide, di-tert-butyl peroxide, dicumyl peroxide, and tert-butyl peroxide.
Peroxides such as butylcumyl peroxide, potassium persulfate, ammonium persulfate, and azo compounds such as azobisisobutyronitrile, azobiscyclohexane, carbonitrile, etc. can be used.

In addition, it is also possible to use a redox initiator that combines a peroxide and a reducing substance, and radical copolymerization using light or heat is also possible.

The amount of the radical initiator used in this case is 0.1 to 50 mmol, preferably 1 to 10 mmol, per 1 mole of compound (B).

Further, the radical copolymerization temperature is the same as that of normal emulsion radical copolymerization, and is 5 to 100°C, preferably 5 to 70°C.
It is.

Furthermore, the amount of water used in radical copolymerization is not particularly limited as long as the aqueous emulsion dispersion during and after polymerization is stable, and usually, the amount of water used for the macromonomer (A) and the compound (B) is stable.
It is used in an amount of about 100 to 10,000 parts by weight, preferably about 150 to 1,000 parts by weight per 100 parts by weight in total.

The copolymer obtained by the present invention forms micelles with an extremely fine particle size, and is a homogeneous aqueous emulsion dispersion with good dispersion stability. property improvers, paints, binders, paper processing materials, adhesives for automobile tires, fiber processing agents,
It can be used as a waterproofing agent for construction, as a wax, and for various other industrial purposes.

[Effect]

The present invention essentially uses a macromonomer (A) that is sparingly soluble in water.
is first aqueous emulsified to form extremely fine micelles, and by adding compound (B) to this and copolymerizing, compound (B) is graft-polymerized on the micelles, resulting in uniform and dispersion stability. An aqueous emulsified dispersion of a graft copolymer with good properties is obtained.

〔Example〕

EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to Examples.

Example 1 Production of macromonomer (A) 1.27% of benzene in a stainless steel reactor according to Reference Example 8 of Japanese Patent Publication No. 5145358. was charged, the temperature inside the reactor was heated to 40°C, and then 5 ec
- A total of 19.5 mff of hexane solution containing 1.0 mol/l of butyllithium was added, and a total of 3 mff of purified styrene was added.
00g was gradually added and the temperature was maintained at 50°C for polymerization. After styrene polymerization, 1.2 g of ethylene oxide was added for capping treatment, and then 3.0 ml of methacrylic acid chloride was added to obtain a styrene macromonomer with methacrylate added to the terminal.

The weight average molecular weight of this styrene macromonomer is 9.4
00, weight average molecular weight/number average molecular weight -1,04, and the proportion of terminal methacrylate functional groups was 86%.

Aqueous emulsification of macromonomer Preparation of powder 375 g of distilled water was placed in a 500 ml beaker, and 15 g of sodium lauryl sulfate was dissolved therein. Furthermore, 58.
Add 14.5 g of the styrene macromonomer dissolved in 1 g of toluene with slow stirring, then place an ultrasonic oscillator in a beaker and irradiate it with ultrasonic waves for about 30 minutes to form an aqueous emulsified dispersion of the styrene macromonomer. Obtained. The particle size of this aqueous emulsified dispersion of styrene macromonomer was measured using a nanosizer (manufactured by Cole Co., Ltd., Model N4, hereinafter referred to as 0.24 μm) and found to be 0.24 μm.

Copolymerization 300 m 7! 31.8 g of the above styrene macromonomer aqueous emulsified dispersion (containing 1.0 g of styrene macromonomer), 1.0 g of butyl acrylate, and 0.05 g of benzoyl peroxide were added to a pressure-resistant bottle, and the polymerization temperature was set at 70°C in a rotary polymerization tank. When polymerized for 1 hour, a uniform dispersion with excellent dispersion stability was obtained.

After the polymerization was completed, the solid content in the emulsified dispersion was measured.
The weight was 6.59 weight, and the polymerization conversion rate of butyl acrylate was 13%. When the particle size of the emulsified dispersion of this copolymer was measured using a nanosizer, it was found to be 0.25 μm.
Met.

A part of the produced emulsified dispersion was collected and 1% by weight of 2,6
-tert-butylhydroxytoluene (BHT)
) in a vacuum dryer kept at a temperature of 50°C (vacuum pressure: 1 gmHg or less) for 24 hours.
Dry for an hour.

After drying, it was dissolved in tetrahydrofuran, and the molecular weight was measured by gel permeation chromatography (GPC). Note that the detector used at this time is the refractive index method (R
Measurements were made using two methods: one based on the UV absorption method (UB method) and the other based on the ultraviolet absorption method (UB method).

This GPC chart is shown in FIG.

In FIG. 1, the horizontal axis shows the count number, and the vertical axis shows the change in refractive index in the case of the RI method, and the change in absorbance (UV absorbance) in the case of the UV method. That is, the solid line in FIG. 1 shows the concentration change by the R1 method, and the broken line shows the UV
The graph shows the concentration change according to the method (ultraviolet wavelength 1254 mμ).

The R1 method corresponds to changes in the concentration of the total force, and the UV method corresponds to the absorption of polystyrene.

As is clear from FIG. 1, the produced copolymer can be obtained by RI method,
Both UV methods show similar behavior, indicating that polystyrene is also present on the polymer side.
This fact suggests that the styrene macromonomer and butyl acrylate are copolymerized.

This is true for the second to fourth examples corresponding to Examples 2 to 4, which will be described later.
The same applies to the figures.

The weight average molecular weight of the graft copolymer obtained in this example was 93,000, and the ratio of weight average molecular weight/number average molecular weight was -4.4.

Example 2 Example 1 except that the butyl acrylate i of Example 1 was increased to 2 g and the amount of benzoyl peroxide was increased to 0.1 g.
Polymerization and post-treatment were carried out in the same manner as above. The solid content of the obtained emulsified dispersion was 11.1% by weight, the conversion rate of butyl acrylate was 87%, the weight average molecular weight of the graft copolymer was 199.000, and the weight average molecular weight / number average molecular weight It was -3.0. A GPC chart of this copolymer is shown in FIG.

As a result of measuring the emulsified dispersion of this copolymer using a nanosizer, the particle size was found to be 0.31 μm.

Example 3 Example 1 except that the amount of butyl acrylate in Example 1 was increased to 4 g and the amount of benzoyl peroxide was increased to 0.2 g.
Polymerization and post-treatment were carried out in the same manner as above. The solid content of the obtained emulsified dispersion was 13.7% by weight, the conversion rate of butyl acrylate was 73%, the weight average molecular weight of the graft copolymer was 324.000, and the weight average molecular weight / number average molecular weight =3.4. A GPC chart of this copolymer is shown in FIG.

As a result of measuring the emulsified dispersion of this copolymer using a nanosizer, the particle size was found to be 0.35 μm.

Example 4 Polymerization and post-treatment were performed in the same manner as in Example 1 except that the amount of butyl acrylate in Example 1 was increased to 20 g and the amount of benzoyl peroxide was increased to 0.2 g. The solid content of the obtained emulsified dispersion was 23.5% by weight, the conversion rate of butyl acrylate was 51%, the weight average molecular weight of the graft copolymer was 1.050,000, and the weight average molecular weight/
The number average molecular weight was -5.6.

A GPC chart of this copolymer is shown in FIG.

As a result of measuring the emulsified dispersion of this copolymer using a nanosizer, the particle size was found to be 0.45 μm.

The emulsified dispersions of copolymers obtained in Examples 1 to 4 above were all stable, and when filtered through polyester velvet, only a very small amount of coagulated material was observed.

Example 5 Journal), Earthworks, 255-260 (19B
A macromonomer was prepared according to 2)).

That is, 100 g of styrene, 7.5 g of iodoacetic acid, and 0.7 g of azobisisobutyronitrile were mixed into 300 mIt.
After replacing with nitrogen, the ampoule is melt-sealed.
Polymerization was carried out at 60°C for 10 hours.

Next, the polymer was coagulated with methanol, dissolved in toluene, and coagulated again with methanol.

When the obtained coagulated product was vacuum dried at 60°C overnight,
29.6 g of polymer was obtained.

Terminal carboxypolystyrene 1 obtained in this way
0 g was dissolved in 150 g of xylene, 0.5 g of glycidyl methacrylate, 5 Q mg of lauryl dimethylamine and 50 mg of hydroquinone were added, and 300 mg of
Pour into a mj2 ampoule, replace with nitrogen, melt seal, 14
The reaction was carried out at 0°C for 6 hours. After the reaction, the polymer was coagulated with methanol, dissolved again in toluene, and coagulated with methanol.

When the coagulated product was vacuum dried at 60°C overnight, the result was 10.3
g of styrene macromonomer was obtained.

This polymer is a styrene macromonomer with a glycidyl methacrylic group bonded to the terminal, and its polymerization average molecular weight is 11,000, weight average molecular weight/number average molecular weight -2,
It was 1.

Preparation of aqueous emulsified dispersion of macromonomer 150 g of distilled water was placed in a 300 ml beaker, and 6 g of sodium lauryl sulfate was dissolved therein. Furthermore, 30 g of a 20% by weight toluene solution of the styrene macromonomer was added to this while slowly stirring, and then an ultrasonic oscillator was placed in the beaker and ultrasonic waves were irradiated for about 20 minutes to aqueous emulsification of the styrene macromonomer. A dispersion was obtained. The particle diameter of this styrene macromonomer emulsified dispersion was measured using a nanosizer and was found to be 0.23 μm.

Copolymerization 300m7! 12.4 g of the above styrene macromonomer aqueous emulsified dispersion (styrene macromonomer 0
．． (containing 4g), and then 10.1g of 1% by weight sodium lauryl sulfate aqueous solution and butyl acrylate/acrylic acid/benzoyl peroxide (weight ratio) = 100/2
A mixed solution of 1/1 log was added and polymerized for 3 hours at a polymerization temperature of 80° C. in a rotary polymerization tank, and a uniform dispersion with excellent dispersion stability was obtained.

After the polymerization was completed, the solid content in the emulsified dispersion was measured.
It was 32.9% by weight, and the polymerization conversion rate of butyl acrylate was 98%. A part of the produced emulsified dispersion was collected, coagulated with ethanol containing 1% by weight of 2,6-tert-butylhydroxytoluene (BHT), and then vacuum-dried at a temperature of 50"C. machine (vacuum pressure; 1
mm) 1 g or less) for 24 hours.

After drying, an attempt was made to dissolve the copolymer in tetrahydrofuran, but it did not dissolve, so the molecular weight could not be measured, indicating that the resulting copolymer was crosslinked. When the emulsified dispersion of this copolymer was measured using a nanosizer in the same manner as above,
The particle size was 0.47 μm.

This shows that if the method of the present invention is followed, a stable aqueous emulsion dispersion can be obtained even in a crosslinked copolymer.

Comparative Example 1 30 QmI! A solution of 1 g of the styrene macromonomer obtained in Example 5 dissolved in 4 g of toluene and an aqueous solution of 1.25 g of sodium laurate dissolved in 50 g of water were added to a pressure-resistant bottle and stirred with a magnetic cooler. 1, a suspension of the styrene macromonomer was produced.

To this, 25 g of a mixed solution of butyl acrylate/acrylic acid/benzoyl peroxide (weight ratio) -100/2/1 was added, and copolymerization was carried out in a rotating polymerization tank at 80°C for 3 hours.

A large amount of coagulated material was generated in the pressure bottle after polymerization, and a stable emulsified dispersion could not be obtained. This coagulum was about 65% by weight of the copolymer and the conversion of butyl acrylate was about 90%.

This shows that if the macromonomer (A) is directly copolymerized with the compound (B) without aqueous emulsification in advance, an aqueous emulsion dispersion of a graft copolymer with excellent stability cannot be obtained.

Comparative example 2 500m7! 300 g of distilled water was placed in a beaker, and 10 g of sodium lauryl sulfate was dissolved therein. Next, a solution of 50 g of the 20% toluene solution of the styrene macromonomer obtained in Example 1, 40 g of butyl acrylate, and 2 g of benzoyl peroxide was slowly added with stirring. An aqueous emulsified dispersion of styrene macromonomer-butyl acrylate was obtained by irradiating ultrasonic waves for 30 minutes.

Next, 50 ml of the aqueous emulsified dispersion was placed in a 300 ml pressure bottle.
g was added thereto, and polymerization was carried out in the same manner as in Example 1. After the polymerization was completed, the solid content in the emulsified dispersion was measured and found to be 9.2% by weight, and the polymerization conversion rate of butyl acrylate was 65%.

Further, the product was post-treated in the same manner as in Example 1, and the molecular weight was measured. The weight average molecular weight was 256,000, and the weight average molecular weight/number average molecular weight was -3.6. Furthermore, when the emulsified dispersion of this copolymer was measured using an electron microscope, it was found that the particle size was large, 2 to 3 μm.

〔Effect of the invention〕

According to the method for producing a copolymer of the present invention, a stable aqueous emulsion dispersion of a graft copolymer can be obtained.

Furthermore, in the present invention, it is also possible to obtain an aqueous emulsion dispersion of a partially crosslinked graft copolymer by selecting the polymerization recipe, conversion rate, and monomer during copolymerization.

Aqueous emulsified dispersions of these graft copolymers can be used as paint modifiers; dispersibility improvers for polymers, fillers, pigments, metal powders, etc.; pressure-sensitive adhesives; polymerization dispersants; antithrombotic medical materials;
Can be used in resin modifiers; adhesives; waxes, etc.

[Brief explanation of drawings]

Figures 1 to 4 show the GP of the copolymer obtained by the present invention.
This is a C chart. Patent Applicant Japan Synthetic Rubber Co., Ltd. Agent Patent Attorney Shige Takashi Shirai

Claims (1)

[Claims] (1) A radical initiator is used to copolymerize a macromonomer (A) that has been previously aqueous emulsified with a vinyl compound and/or a conjugated diene compound (B), or an aqueous emulsified dispersion of the compound (B). A method for producing a featured copolymer.