JP2002241505A - Method for producing coagulated latex - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method enabling enlarged polymer latex to be obtained without forming coagulum. SOLUTION: This method for enlarging polymer latex is characterized by comprising obtaining enlarged polymer latex in a short time by adding an emulsifier of specific chemical structure to a polymer latex of small-sized particles obtained by emulsion polymerization and subjecting the resultant polymer latex to agitation under specific conditions of an enlarging device and addition of an acid or base under specific conditions so as to form no byproduct coagulum and keep solid concentrations becoming no industrial problem.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for enlarging a polymer latex, and more particularly to a method for producing a polymer latex containing large-diameter particles stably in a short time without producing coagulum in a step of enlarging. It relates to a manufacturing method.

[0002]

2. Description of the Related Art Many resins obtained by emulsion polymerization using a rubber latex as a substrate are important as engineering plastics. Examples of such resins are ABS resin and polystyrene obtained by graft polymerization of styrene and acrylonitrile to polybutadiene. An ASA resin that graft-polymerizes styrene and acrylonitrile to butyl acrylate can be used.

[0003] In general, the properties of a polymer containing a grafted rubber particle as a component vary depending on the graft polymerization method, but the physical properties of the polymer also vary greatly by changing the particle size and distribution of rubber substrate particles. It is well known that it is necessary to use a rubber substrate having a particle size and distribution. For example, in the case of ABS resin, it is generally difficult to obtain good physical properties unless the particle diameter is at least 200 nm or more, and furthermore, 500 nm
It is preferable that these particles are contained at all.

[0004] However, the production of polymer particles having such a large particle size by emulsion polymerization requires a large reduction in the polymerization rate as easily derived from the general theory of emulsion polymerization. Disadvantageous. Various methods for enlarging a polymer latex having a small particle diameter have been known. For example, US Pat. No. 2,446,101
No. 2,494,002,
Although a method of adding ammonium chloride to latex is disclosed, in such a method of enlarging using water-soluble salts, a large amount must be added in order to increase the particle diameter enlarging effect because the effect is small. Must. Moreover, it is necessary to add a large amount of an emulsifier to re-stabilize the polymer latex after the enlargement. Furthermore, these low-molecular components added in large amounts in the enlargement step may cause problems in the stability in the subsequent step, and may remain in the final polymer and impair the quality of the product, which is not preferable.

[0005] US Patent No. 3,281,386,
Nos. 3,551,370 and 3,652,
No. 721 proposes a method of enlarging latex particles by inactivating the emulsifier's surface activity using acetic acid or acetic anhydride. However, in this method, the step of adding an acid to the latex is the most unstable, and the coagulated particles (agglomerated and enlarged until the particles become 10μ or more) at the interface where the added acid diffuses into the latex, and the emulsion is no longer in an emulsified state. Is a particle that cannot be returned (hereinafter “coagulum”)
In many cases, the concentration of the acid must be sufficiently low in order to prevent the formation. The use of such a low-concentration acid not only reduces the final latex concentration but also reduces the effect of enlarging the particle diameter itself, which is a disadvantageous method.

On the other hand, a method using a so-called polymer flocculant having a hydrophilic group and a hydrophobic group in one molecule is disclosed in US Pat. Nos. 3,049,500 and 3,056,758.
No. 3,330,795, No. 3,
No. 288,741 and JP-B-46-14539.
No. 1993. In these methods, the polymer flocculant is used as it is or partially modified, and used alone or in combination with a specific salt. However, the method using a polymer flocculant requires a long time for the enlargement step, the degree of particle size enlargement is small, and it is difficult to stop the enlargement, and even during storage of the enlarged latex. It has a major disadvantage that the particle size changes.

[0007] By the way, the methods currently used industrially include a method using a high-pressure homogenizer and a method in which a solvent having a good affinity for the polymer latex is added. In the former case, Only a part of the latex particles is enlarged and a latex having a uniform particle size cannot be obtained.In the latter case, it is necessary to distill off the solvent as a pre-stage of graft polymerization, and there is much room for improvement. . Further, for the purpose of enlargement, a method of adding various types of emulsifiers and enlarging with an acid is proposed in Japanese Patent Application Laid-Open No. 9-104715, but it is necessary to control the particle size to be uniform. Not only is it difficult, but the use of various types of emulsifiers complicates the measurement,
There is a drawback that the equipment becomes industrially complicated and it becomes difficult to control the particle diameter after enlargement.

Further, as a technique for reducing coagulum during enlargement, Japanese Unexamined Patent Publication Nos. 11-209405 and 11-222501 disclose acidic substances in latex in a tank from the bottom of an insert tube or a stirring tank. The method of supplying directly into the latex in the tank has been proposed.However, the supply pipe of the acidic substance by the latex is blocked, the coagulum is generated by the introduction pipe, and the acidic substance in the supply pipe is latex in the tank. Has the disadvantage that the latex concentration is reduced by substitution with a substance which does not adversely affect the latex.

[0009]

The present invention relates to a method for enlarging a polymer latex, and more particularly, to the addition of an emulsifier having a specific chemical structure in an enlarging step, the specific stirring conditions of an enlarging apparatus, and the identification of an acid or a base. The purpose of the present invention is to provide a method for enlarging a polymer latex having a particle diameter suitable for an ABS resin, which can be industrially produced in a short time without producing coagulum by the addition conditions of the coagulum and maintaining a solid content concentration that does not pose an industrial problem. And

[0010]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have added an emulsifier having two or more kinds of hydrophilic groups having different molecular structures in a molecule, and added an inorganic acid and It has been found that adding any one or a mixture of acids selected from organic acids under specific stirring and addition conditions to enlarge the polymer latex and then neutralize it with a base can meet the purpose, The present invention has been accomplished based on this finding.

That is, the present invention provides: An emulsifier having two or more types of hydrophilic groups having different molecular structures in a molecule is added to a small particle size polymer latex having a weight average particle size of 10 to 200 nm obtained by an emulsion polymerization method, and a solid content in a polymer latex solution of 100% by weight. To 1 part by weight, one or more acids are added to cause enlargement, then a base is added, and the weight average particle diameter is 200 to 5000 n.
m, and the solid content concentration of the polymer latex is 30 to 60.
In the method for producing an enlarged latex for obtaining a polymer latex solution by weight, in a device for obtaining an enlarged polymer latex, power given from a stirring blade of a stirring device per unit volume of the polymer latex solution represented by the following formula (A) (Hereinafter referred to as “Pv”) is 0.04 to 40
A method for producing an enlarged latex, which is in the range of W / m ³ .

Pv = Np × ρ × n ³ × d ⁵ / V (A) where Np: power number (−), which is a dimensionless number related to power required for stirring, ρ: liquid density (kg / m ³⁾ ) N: Number of rotation of stirring blade (s ^-1 ) d: Diameter of stirring blade (m) V: Amount of latex to be enlarged (m ³ ), and

2. In an apparatus for obtaining an enlarged polymer latex, when adding an acid to the polymer latex, or when adding an acid and adding a base,
(B) The impact energy (hereinafter referred to as “Pv ′”) of the additive per unit area of the latex surface represented by the formula (B) is in the range of 0.01 to 10000 W / m ^2.
2. The method for producing an enlarged latex according to item 1. ^{_{Pv '= (v 0 2/}} 2 + g × h) × v 1 / S (B) formula, where, v _0: initial velocity (m / s) of the additive g: gravitational acceleration (9.8m / s ²⁾ h: The distance from the addition port to the liquid surface (m) v ₁ : Addition speed of the additive (kg / s) S: It relates to the liquid surface area (m ² ) of the additive collision.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The method for enlarging a polymer latex of the present invention comprises adding an emulsifier having a specific chemical structure to a small particle size polymer latex obtained by an emulsion polymerization method having a particle size of 10 to 200 nm. By adding an acid or an acid and a base under the stirring and addition conditions of
In this method, the polymer latex having an average particle diameter of 200 nm to 5000 nm is enlarged.

The polymer latex having a small particle diameter of 10 to 200 nm used in the present invention is produced by a conventional emulsion polymerization. The surfactant used at this time is not particularly limited. It is represented by an emulsifier having a salt of an alkali metal,
Anionic surfactants such as potassium laurate, sodium oleate, mixed fatty acid potassium, potassium rosinate, sodium alkylbenzenesulfonate, and phenylethoxy sulfate are used.

Further, nonionic surfactants such as polyoxyethylene alkyl ether, polyoxyethylene alkyl allyl ether, sorbitan fatty acid ester and glycerin fatty acid ester can be used. In the present invention, the small particle size polymer latex refers to a polymer latex of 200 nm or less, which is generally called a small particle size. As the particle size of the small particle size polymer latex,
Although it is not particularly limited because it is selected from the viewpoint of the industrial advantage produced by emulsion polymerization for a short time and the particle diameter enlargement effect in the enlargement step, it is preferably 10 to 200 nm, more preferably 15 to 150 nm, and still more preferably. 30 ~
100 nm.

The components of the small particle size polymer latex include, for example, polybutadiene latex and polystyrene-latex.
Soft polymer latex such as butadiene copolymer latex, polyacrylonitrile-butadiene copolymer latex, polybutyl acrylate-butadiene copolymer latex, and polybutyl acrylate latex are preferable, and polystyrene latex and polyacrylonitrile-styrene copolymer latex Hard polymer latex such as can be used.

In the present invention, the emulsifier added before the enlargement means that the compound has a hydrophilic group and a hydrophobic group in the compound,
Among the compounds capable of lowering the liquid-liquid or solid-liquid interfacial tension, the hydrophilic group may be any combination of anionic, nonionic, and cationic, but has a different molecular structure.
It is a compound having more than one kind of hydrophilic group in the molecule. In the present invention, the nonionic hydrophilic group is a nonionic hydrophilic group, for example, a polyalkylene oxide group, an ester group, a ketone group, an alcohol group and the like. Preferably it is a polyalkylene oxide group. Examples of the emulsifier used in the present invention include the following.

Emulsifier Type I Glycidyl ether derivatives and glycidyl ester derivatives represented by the following formula (1)

Embedded image

In the formula, X is an optionally substituted alkyl group, alkenyl group, alkylaryl group, aralkylaryl group, acyl group, (meth) allyl group or (meth) allyl group.
Shows an acryloyl group. Y is hydrogen or —SO ₃ M
(M is hydrogen, an alkali metal, an alkaline earth metal, ammonium or hydroxyalkylammonium having 1 to 4 carbon atoms), or —CH ₂ C
OOM (M is hydrogen, alkali metal, alkaline earth metal,
Ammonium or a hydroxyalkylammonium having 1 to 4 carbon atoms) or a carboxylate represented by the formula (1 ′):

[0021]

Embedded image Or a phosphoric acid monoester represented by the formula (1 ″)

[0022]

Embedded image The sulfosuccinic acid monoester salt represented by is shown.

Z represents an alkyl group, an alkenyl group, an alkylaryl group, an aralkylaryl group or an acyl group which may have a substituent having 8 to 30 carbon atoms. A represents an alkylene group having 2 to 4 carbon atoms or a substituted alkylene group; m represents a positive number of 0 to 100; Specific examples of the formula (1) include the following formulas (2) to (9).

[0024]

Embedded image

[0025]

Embedded image

[0026]

Embedded image

[0027]

Embedded image

[0028]

Embedded image

[0029]

Embedded image

[0030]

Embedded image

[0031]

Embedded image

Emulsifier type II Glycidyl ether derivatives and glycidyl ester derivatives represented by the following formula (10)

Embedded image In the formula, X represents an optionally substituted alkyl group, alkenyl group, alkylaryl group, aralkylaryl group or acyl group, (meth) allyl group or (meth) acryloyl group.

Y is given by the formula (10 ')

Embedded image

And a phosphoric acid diester salt or a sulfosuccinic acid diester salt, respectively. Z represents an alkyl group, an alkenyl group, an alkylaryl group, an aralkylaryl group or an acyl group which may have a substituent having 8 to 30 carbon atoms. A represents an alkylene group having 2 to 4 carbon atoms or a substituted alkylene group; m and n each represent a positive number of 0 to 50;

As a specific example of the equation (10), the following equation (1)
1) is mentioned.

Embedded image

Emulsifier type III Ether derivatives and ester derivatives represented by the following formula (12)

Embedded image

In the formula, X represents an optionally substituted alkyl group, alkenyl group, alkylaryl group, aralkylaryl group or acyl group, (meth) allyl group or (meth) acryloyl group. Y is hydrogen or a methyl group, or -SO ₃ M (M is hydrogen, alkali metal, alkaline earth metal, ammonium or hydroxyalkyl ammonium having from 1 to 4 carbon atoms) sulfate represented by, or -CH, ₂ COOM (M is hydrogen, alkali metal, alkaline earth metal, ammonium, or 1 carbon atom
To 4 hydroxyalkylammonium), or a phosphoric acid monoester salt represented by the formula (1 ′). Z represents an alkyl group having 8 to 30 carbon atoms. A represents an alkylene group having 2 to 4 carbon atoms or a substituted alkylene group; m represents a positive number of 0 to 20; As specific examples of the expression (12), the following expressions (13) and (1)
4).

[0038]

Embedded image

[0039]

Embedded image

Emulsifier type IV Ether derivatives and ester derivatives represented by the following formula (15)

Embedded image In the formula, X represents an optionally substituted alkyl group, alkenyl group, alkylaryl group, aralkylaryl group or acyl group, (meth) allyl group or (meth) acryloyl group.

Y is expressed by the formula (15 ')

Embedded image The phosphoric diester salt represented by Z is carbon number 8
Represents up to 30 alkyl groups. A represents an alkylene group having 2 to 4 carbon atoms or a substituted alkylene group, and n and m each represent a positive number of 0 to 50.

Emulsifier type V Compound represented by the following formula (16)

Embedded image

In the formula, X is an optionally substituted alkyl group, alkenyl group, alkylaryl group, aralkylaryl group, or acyl group, (meth) allyl group, (meth) acryloyl group, or (α- Represents a methyl) vinyl group. Y is -SO ₃ M (M is hydrogen, alkali metal, alkaline earth metal, ammonium or hydroxyalkyl ammonium having from 1 to 4 carbon atoms) sulfate represented by or -CH ₂ COOM (M is hydrogen, Alkali metal, alkaline earth metal, ammonium or C1
To 4 hydroxyalkylammonium) or a phosphoric acid monoester salt represented by the formula (1 ′). R1 is an alkyl group having 6 to 18 carbon atoms, alkenyl group or aralkyl group, R ₂ is hydrogen,
Or an alkyl group, alkenyl group or aralkyl group having 6 to 18 carbon atoms, R ₃ is hydrogen, or a propenyl group,
A represents an alkylene group having 2 to 4 carbon atoms or a substituted alkylene group, and n represents a positive number of 1 to 200. Specific examples of the equation (16) include the following equations (17) to (22).

[0044]

Embedded image

[0045]

Embedded image

[0046]

Embedded image

[0047]

Embedded image

[0048]

Embedded image

[0049]

Embedded image

Emulsifier type VI Compound represented by the following formula (23)

Embedded image

In the formula, X is an optionally substituted alkyl group, alkenyl group, alkylaryl group, aralkylaryl group, acyl group, (meth) allyl group, (meth) acryloyl group, or (α-methyl ) Represents a vinyl group. R
₁ is an alkyl group, alkenyl group or aralkyl group having 6 to 18 carbon atoms, R ₂ is hydrogen, or an alkyl group, alkenyl group or aralkyl group having 6 to 18 carbon atoms, R ₃
Represents hydrogen or a propenyl group, A represents an alkylene group having 2 to 4 carbon atoms or a substituted alkylene group, and n represents a positive number of 1 to 200. Y represents a phosphoric diester salt represented by the formula (15 ′).

Emulsifier type VII Succinic acid derivative represented by the following formula (24)

Embedded image

In the formula, X represents an optionally substituted alkyl group, alkenyl group, alkylaryl group, aralkylaryl group, acyl group, (meth) allyl group or (meth) allyl group.
Shows an acryloyl group. B ₁ and B ₂ represent Y or Z shown below, and B ₁ and B ₂ are different. Y is M
Or -SO ₃ M (M is hydrogen, alkali metal, alkaline earth metal, ammonium, or hydroxyalkyl ammonium having from 1 to 4 carbon atoms). Z is a group having 8 or more carbon atoms.
And represents 30 alkyl groups or alkenyl groups. A is an alkylene group having 2 to 4 carbon atoms or an alkylene group having a substituent, and m and n are positive numbers of 0 to 50. Specific examples of the formula (24) include the following formulas (25) to (28).

[0054]

Embedded image

[0055]

Embedded image

[0056]

Embedded image

[0057]

Embedded image

Emulsifier type VIII A diol compound represented by the following formula (29)

Embedded image

In the formula, A is an alkylene group having 2 to 4 carbon atoms, R ₁ is a hydrocarbon group having 8 to 24 carbon atoms, R ₂ is hydrogen or a methyl group, and m and n are those of m + n. 0 to
Each is a number from 0 to 100 such that the value is between 100 and M is a hydrogen atom, an alkali metal, an alkaline earth metal, ammonium, or hydroxyalkylammonium having 1 to 4 carbon atoms.

As a specific example of the equation (29), the following equation (3)
0).

Embedded image

Emulsifier Type IX Compound represented by the following formula (31)

Embedded image In the formula, X represents hydrogen, a (meth) allyl group, a (meth) allyloxy group, a (meth) acryloyl group, a (meth) acryloyloxy group, or the following formula (31 ′).

[0062]

Embedded image

Y is hydrogen, or —SO ₃ M (M is hydrogen,
A sulfate salt represented by an alkali metal, an alkaline earth metal, ammonium, or hydroxyalkylammonium having 1 to 4 carbon atoms, or —CH ₂ COOM (M
Is hydrogen, an alkali metal, an alkaline earth metal, ammonium, or a hydroxyalkylammonium having 1 to 4 carbon atoms), a carboxylate represented by the formula (1 ′), or a phosphate monoester represented by the formula (1 ′): A sulfosuccinic acid monoester salt represented by (1 ″) is shown. Z represents an alkylene group which may have a substituent having 6 to 30 carbon atoms.
A represents an alkylene group having 2 to 4 carbon atoms or a substituted alkylene group; n and m each represent a positive number of 0 to 50; Specific examples of the formula (31) include the following formulas (32) to (34).

[0064]

Embedded image

[0065]

Embedded image

[0066]

Embedded image

Emulsifier type X Compound represented by the following formula (35)

Embedded image In the formula, R ₁ represents an alkyl group having 6 to 8 carbon atoms, an alkenyl group, or an alkylphenyl group. n is an integer of 3 to 20. m ₁ and m ₂ are each an integer of 1 or more, and m ₁ + m ₂ = 3. Specific examples of the equation (35) include the following equations (36) to (37).

[0068]

Embedded image

[0069]

Embedded image

Emulsifier type XI Compound represented by the following formula (38)

Embedded image In the formula, R ₂ represents CH ₃ or H. q is an integer of 1 to 10. r ₁ and r ₂ are each an integer of 1 or more, and r ₁ +
r ₂ = 3. Specific examples of the expression (38) include the following expressions (39) to (40).

[0071]

Embedded image

[0072]

Embedded image

The combination of hydrophilic groups is not particularly limited, but is preferably a combination of an anionic group and a nonionic group, and more preferably a combination of a sulfonic acid group and a polyalkylene oxide group. Further, the amount of the emulsifier to be added is 0.01 to 100 parts by weight of the solid content of the polymer latex solution.
To 1 part by weight, more preferably 0.05 to 0.1 part by weight.
5 parts by weight.

Further, the concentration of the aqueous solution of the emulsifier to be added must be dilute from the viewpoint of dispersibility in the latex. To maintain an industrially effective concentration of the latex, 0.1 to 50% by weight is required. Preferred, more preferably 1 to
40% by weight. If the addition amount of the emulsifier is too small, coagulum is generated in the step of adding the acid, and if it is too large, the effect of increasing the particle diameter tends to be small. The timing of adding the emulsifier may be at the time of polymerization of the polymer latex having a small particle diameter or after the polymerization. In the present invention, the enlarged polymer latex refers to a polymer latex having a weight average particle size of 200 to 5000 nm.

Acids added for enlargement include sulfuric acid, hydrochloric acid, sulfonic acid, phosphoric acid, oxalic acid, nitric acid, propionic acid, propionic anhydride, benzoic acid, benzoic anhydride, formic acid, citric acid, lactic acid, A mixture of one or more of acids such as maleic acid, maleic anhydride, itaconic acid, acetic acid, acetic anhydride and the like can be used. However, the concentration range is not particularly limited because it varies depending on the type of acid used, and the type and amount of an emulsifier having an acidic and good surface-active ability, but is limited as far as coagulum is not generated in the enlargement process. The acid concentration is preferably 1 to 30% by weight because the concentration is preferably high. More preferably, it is 5 to 20% by weight.

The amount of the acid to be added to the polymer latex having a small particle diameter is not particularly limited because it varies depending on the type and amount of the emulsifier used, but is preferably an amount that makes the pH of the polymer latex solution 6 or less. In the present invention, if the solid content concentration of the polymer latex is too high, coagulum tends to occur in the step of adding an acid, and if it is too low, the effect of enlarging the particle size tends to be small. However, the concentration range is not particularly limited because it varies depending on the type and concentration of the acid used, and the type and amount of the emulsifier having good acidity and good surface activity, but for industrial purposes such as productivity, It is preferably 30 to 60% by weight based on the weight of the entire polymer latex solution.

As the base used for stabilizing the polymer latex having an enlarged particle diameter, for example, sodium hydroxide,
Examples thereof include potassium hydroxide, ammonium hydroxide (aqueous ammonia), potassium carbonate, and sodium carbonate.
Preferred are sodium hydroxide and potassium hydroxide.
The addition amount is appropriate to neutralize the acid added in the enlargement step. When the concentration is too high, coagulum is formed in the addition step, and when the concentration is too dilute, the latex concentration decreases. Therefore, the concentration is 1 to 30% by weight, preferably 5 to 20% by weight.

The apparatus for enlarging the polymer latex in the present invention is not particularly limited. In the apparatus for enlarging the polymer latex, a stirring device is used per unit volume of the polymer latex solution represented by the following formula (A). If the power (Pv) given by the stirring blade is too small, the dispersion of the acid to be added becomes insufficient and a large amount of coagulum is generated. On the other hand, if it is too large, local dispersion and destruction of the polymer latex near the stirring blade occurs, and a large amount of coagulum is generated. Therefore, the Pv value is 0.04 to 40
It must be within the range of W / m ³ , preferably 0.05 to 25 W / m ³ , more preferably 0.07 to 25 W / m ^3.
It is within the range of 10 W / m ³ .

Further, when an acid is added to the polymer latex, or when an acid is added and a base is added, the collision energy (Pv ') of the additive per unit area on the latex surface represented by the formula (B) Is too small, the time for adding the acid is prolonged, the time for adding the acid to keep the polymer latex unstable is prolonged, and a large amount of coagulum is generated. On the other hand, if it is too large, local dispersion and destruction of the polymer latex in the vicinity of the addition occurs, and a large amount of coagulum is generated. Therefore, the Pv ′ value is 0.01 to 10000 W / m
² , more preferably in the range of 0.1 to 5000 W / m ² .

Pv = Np × ρ × n ³ × d ⁵ / V (A) where Np: power number (−), which is a dimensionless number related to power required for stirring, ρ: liquid density (kg / m ³⁾ N) Number of rotations of the stirring blade (s ^-1 ) d: Diameter of the stirring blade (m) V: Amount of latex to be enlarged (m ³ ) Here, Np is generally represented by a function of the Reynolds number. It is a function that changes depending on the shape and size of the tank and the blade and the nature of the liquid to be stirred.

[0081] ^{_{Pv '= (v 0 2/}} 2 + g × h) × v 1 / S (B) formula v _0: initial velocity of Additives (m / s) g: gravitational acceleration (9.8m / s ²⁾ h: Distance from addition port to liquid level (m) v ₁ : Addition rate of additive (kg / s) S: Additive collision liquid surface area (m ² ) When enlargement is performed outside the range of Pv, Pv ' Can produce large amounts of coagulum.

Next, the method of the present invention will be described in detail with reference to examples. In Examples and Comparative Examples, “parts” represents parts by weight, and the average particle size is a weight (volume) average particle size, and is a Microtrac Mode manufactured by Nikkiso Co., Ltd.
1: Determined by the dynamic light scattering method using 9340 UPA. The solid content concentration (% by weight) was measured by drying the polymer latex solution at 130 ° C. for 1 hour.
The amount of coagulum generated in the enlargement process is (weight of coagulum after drying) / (solid content of charged latex)
It was calculated as a coagulum ratio (wt%) from × 100.

The production of a polybutadiene latex having a weight average particle diameter of 80 nm was carried out as follows. 1,3 butadiene monomer 100 parts, deionized water 135 parts, potassium oleate 3.0 parts, sodium sulfate 0.3 parts, potassium persulfate 0.15 parts, tertiary decyl mercaptan 0.20 parts, and potassium hydroxide 0.18 parts were stored in a pressure-resistant container equipped with a stirrer, and the temperature was 60 ° C.
To initiate polymerization. After a polymerization time of 15 hours, a polybutadiene latex having a weight average particle diameter of 80 nm and a solid content of 40% by weight was obtained.

[0084]

Example 1 Weight average particle diameter 80n obtained by a conventional method
m, a polybutadiene latex having a solid content concentration of 40% by weight was stirred at a Pv value of 2 W / m ³ , and emulsifier (17) was added in an amount of 0.125 parts by weight per 100 parts of the solid content of the latex.
Minutes, and after 10 minutes, the Pv ′ value is 15000 W /
At m ² , 0.75 parts (converted to pure content) of 7.5 wt% acetic acid was added over 25 minutes. After continuing that state for 5 minutes,
0.75 parts (in terms of pure content) of 0.85 wt% potassium hydroxide was added over 10 minutes to obtain a stable latex. The resulting latex was filtered through a 100-mesh net and had a good coagulum ratio of 0.7% by weight. When this latex was analyzed, the weight average particle diameter was 310.
It was a highly concentrated latex having an average particle diameter of nm and a solid content of 37% by weight.

[0085]

Example 2 A sample was prepared in the same manner as in Example 1 except that the Pv ′ value was set to 7000 W / m ² . The coagulum ratio is 0.
It was as good as 3 wt%. When this latex was analyzed, it was a high-concentration enlarged latex having a weight average particle diameter of 310 nm and a solid concentration of 37% by weight.

[0086]

Example 3 A sample was prepared in the same manner as in Example 1 except that the Pv ′ value was set to 40 W / m ² . Coagulum rate is 0.1w
t% was good. When this latex was analyzed, it was a high-concentration enlarged latex having a weight average particle diameter of 310 nm and a solid concentration of 37% by weight.

[0087]

Example 4 The procedure of Example 3 was repeated except that 0.65 part of acetic acid and 0.65 part of potassium hydroxide were used. The coagulum ratio was as good as 0.07 wt%. When this latex was analyzed, it was a high-concentration enlarged latex having a weight average particle diameter of 250 nm and a solid content of 37% by weight.

[0088]

Example 5 The procedure of Example 3 was repeated except that 1.0 part of acetic acid and 1.0 part of potassium hydroxide were used. The coagulum ratio was as good as 0.3 wt%. When this latex was analyzed, the weight average particle diameter was 38.
It was a high-concentration enlarged latex having a thickness of 0 nm and a solid content of 37% by weight.

[0089]

Example 6 The procedure of Example 3 was repeated except that 1.5 parts of acetic acid and 1.5 parts of potassium hydroxide were used. The coagulum ratio was as good as 0.4 wt%. When this latex was analyzed, the weight average particle diameter was found to be 45%.
It was a high-concentration enlarged latex having a thickness of 0 nm and a solid content of 37% by weight.

[0090]

Example 7 The procedure of Example 3 was repeated except that emulsifier (3) was used. The coagulum ratio was as good as 0.3 wt%. When this latex was analyzed, it was a high-concentration enlarged latex having a weight average particle diameter of 310 nm and a solid concentration of 37% by weight.

[0091]

Example 8 Example 3 except that the emulsifier (34) was used.
Created in the same way as The coagulum ratio was as good as 0.4 wt%. When this latex was analyzed, it was a high-concentration enlarged latex having a weight average particle diameter of 308 nm and a solid concentration of 37% by weight.

[0092]

Example 9 A sample was prepared in the same manner as in Example 3 except that the Pv value was set to 30 W / m ³ . Coagulum ratio is 1.0wt
% Was good. When this latex was analyzed,
It was a highly concentrated latex having a weight average particle size of 310 nm and a solid content of 37% by weight.

[0093]

Example 10 A sample was prepared in the same manner as in Example 3 except that the Pv value was set to 15 W / m ³ . Coagulum ratio is 0.7w
t% was good. When this latex was analyzed, it was a high-concentration enlarged latex having a weight-average particle diameter of 312 nm and a solid concentration of 37% by weight.

[0094]

Comparative Example 1 A battery was prepared in the same manner as in Example 3 except that the Pv value was set to 50 w / m ³ . Coagulum rate is 10wt%
And many. When this latex was analyzed, it was an enlarged latex having a weight average particle diameter of 310 nm and a solid concentration of 34% by weight.

[0095]

Comparative Example 2 The same procedure as in Example 3 was carried out except that the Pv value was set to 0.03 w / m ³ . Coagulum rate is 20w
When this latex, which was as large as t%, was analyzed, it was an enlarged latex having a weight average particle diameter of 310 nm and a solid concentration of 30% by weight.

[0096]

Comparative Example 3 The same procedure as in Example 1 was carried out except that the Pv value was set to 50 w / m ³ . Coagulum ratio is 20wt%
And many. When this latex was analyzed, it was an enlarged latex having a weight average particle diameter of 310 nm and a solid content concentration of 30% by weight.

[0097]

Comparative Example 4 A battery was prepared in the same manner as in Example 1 except that the Pv value was set to 0.03 w / m ³ . Coagulum rate is 30w
t%. When this latex was analyzed, it was an enlarged latex having a weight average particle diameter of 320 nm and a solid concentration of 25% by weight.

[0098]

Comparative Example 5 The same procedure as in Example 3 was carried out except that the Pv value was set to 0.03 w / m ³ and the Pv ′ value was set to 0.001 W / m ² . The coagulum ratio was as high as 50 wt%. When this latex was analyzed, the weight average particle diameter was 32.
It was an enlarged latex having a thickness of 5 nm and a solid concentration of 18% by weight.

[0099]

According to the present invention, coagulum is produced by the addition of an emulsifier having a specific chemical structure in particular in the process of enlargement, the specific stirring conditions of the enlarger, and the specific conditions of addition of acid or base. In addition, it is possible to provide a method for enlarging a polymer capable of industrially producing a polymer latex having a particle diameter suitable for an ABS resin in a short time while maintaining a solid content concentration that does not cause an industrial problem.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08K 5/09 C08K 5/09 C08L 101/00 C08L 101/00 // (C08L 101/00 (C08L 101 / 00 71:02) 71:02) (72) Inventor Kensuke Inoue 3-13-1, Shioridori, Kurashiki-shi, Okayama F-term in Asahi Kasei Corporation 4F070 AA06 AA07 AA08 AA11 AA18 AA33 AB16 AC13 AC16 AC17 AC20 AC42 AC55 AC57 AC84 AE14 AE30 FA05 FB05 FB06 FC02 4J002 AC031 AC071 AC081 BC031 BC061 BG041 BN151 CH052 DD017 DE058 DE228 DF008 DF027 DG017 DG037 DH027 EF037 EF067 EF097 EH006 FD147 EW206 207

Claims (2)

[Claims] 1. A small particle size polymer latex having a weight average particle size of 10 to 200 nm obtained by an emulsion polymerization method is mixed with an emulsifier having two or more hydrophilic groups having different molecular structures in a molecule in a polymer latex solution. Solid content of 100
0.01 to 1 part by weight based on parts by weight, one or more acids are added to cause enlargement, then a base is added, the weight average particle diameter is 200 to 5000 nm, and the solid content concentration of the polymer latex is In a method for producing an enlarged latex for obtaining a polymer latex solution of 30 to 60% by weight,
In a device for obtaining an enlarged polymer latex, the power (hereinafter referred to as “Pv”) given from a stirring blade of a stirring device per unit volume of a polymer latex solution represented by the following formula (A) is 0.04 to 40 W / m. ^3. A method for producing an enlarged latex, which is within the range of ³ . Pv = Np × ρ × n ³ × d ⁵ / V (A) where Np: power number which is a dimensionless number related to power required for stirring (−) ρ: liquid density (kg / m ³ ) n: Number of rotation of stirring blade (s ^-1 ) d: diameter of stirring blade (m) V: amount of latex to be enlarged (m ³ ) 2. An apparatus for obtaining an enlarged polymer latex, wherein an acid is added to the polymer latex, or when an acid is added and a base is added.
(B) collision energy (referred to hereinafter as "Pv '") of the additive per unit area of the latex surface represented by formula is in the range of 0.01~10000W / m ^2, enlargement of claim 1 Production method of activated latex. ^{_{Pv '= (v 0 2/}} 2 + g × h) × v 1 / S (B) formula, where, v _0: initial velocity (m / s) of the additive g: gravitational acceleration (9.8m / s ²⁾ h: Distance from addition port to liquid level (m) v ₁ : Addition rate of additive (kg / s) S: Additive impact liquid surface area (m ² )