JP3393452B2 - Composite crosslinked polymer particles and method for producing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite crosslinked polymer particle which is excellent in resin modification, resin film blocking prevention and slipperiness, and a method for producing the same.

[0002]

2. Description of the Related Art Crosslinked polymer particles having a particle size in the range of 0.1 to 10 .mu.m are antiblocking agents for resin films, lubricants for films, spacers, standard particles, antigen-antibody reaction test particles, and thermal paper runnability. It is useful and used as a stabilizer, an additive for toner, an additive for cosmetics, a rheology control agent, a low shrinkage agent and the like. The crosslinked polymer particles in this range can be usually produced by a suspension polymerization method. In addition, a special emulsion polymerization method (JP-A-1-31545)
4). However, when these particles are added to a resin or the like, the affinity with the resin is poor and the particles are aggregated and cannot be dispersed in the resin. Also,
When the crosslinked polymer particles are added to the resin film, when the laminated resin film is peeled off, the crosslinked polymer particles may be peeled off from the resin, and the particles may be scattered on the resin film and become powdery. is there. They are,
This is a phenomenon caused by the lack of affinity between the crosslinked polymer particles and the resin. Generally, if the affinity between the crosslinked polymer particles and the resin is increased, the performance such as the antiblocking effect does not appear. Therefore, there has been a demand for crosslinked polymer particles that have high affinity with the resin, high dispersibility of the particles in the resin, and good antiblocking properties.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional technical problems. The presence of a specific polymer on the surface of crosslinked polymer particles makes it possible to obtain an affinity with a resin, It is an object of the present invention to provide composite crosslinked polymer particles having excellent dispersibility of particles in a resin and blocking resistance, and a method for producing the same.

[0004]

Means for Solving the Problems According to the present invention, the surface of crosslinked polymer particles (A) obtained by polymerizing a polymerizable monomer having a content of the crosslinkable monomer of 27.5 % by weight or more is The polymer (B) obtained by polymerizing a polymerizable monomer having a content of less than 10% by weight is partially or entirely coated, and the weight ratio of (A) / (B) is 10
0 / 0.01 to 900 parts by weight, the average particle size is 0.01 to
In the presence of 100 parts by weight of the crosslinked polymer particles (A) obtained by polymerizing the composite crosslinked polymer particles characterized by having a size of 10 μm and the polymerizable monomer having a content of the crosslinkable monomer of 27.5 % by weight or more, The content of the cross-linkable monomer is less than 10% by weight and the polymerizable monomer is 0.01 to 90.
The present invention provides a method for producing composite crosslinked polymer particles, which comprises polymerizing 0 part by weight. Hereinafter, the present invention will be described in detail.

The composite crosslinked polymer particles of the present invention contain a crosslinkable monomer having two or more groups having a polymerizable double bond in the molecule (hereinafter, simply referred to as "crosslinkable monomer") in a content of 27.5. A polymer (B) obtained by polymerizing a polymerizable monomer having a content of the crosslinkable monomer of less than 10 % by weight on the surface of the crosslinked polymer particles (A) obtained by polymerizing the polymerizable monomer in an amount of at least wt%. Partially or entirely laminated, and the weight ratio of (A) / (B) is 100 / 0.01
˜900 parts by weight and an average particle size of 0.01 to 10 μm.

The content of the crosslinkable monomer in the polymerizable monomer used in the crosslinked polymer particles (A) is 27.5 % by weight.
% Or more. When the content of the crosslinkable monomer is less than 27.5 % by weight, the antiblocking property is poor.

The content of the crosslinkable monomer in the polymerizable monomer used in the polymer (B) is less than 10% by weight, preferably 8% by weight or less, more preferably 5% by weight or less. If the content of the crosslinkable monomer among the polymerizable monomers constituting the polymer (B) is 10% by weight or more, it cannot be dispersed in the resin.

The amount of the polymer (B) laminated partially or entirely on the surface of the crosslinked polymer particles (A) is 0.01 to 900 based on 100 parts by weight of the crosslinked polymer particles (A).
The amount is preferably 0.1 to 400 parts by weight, more preferably 0.5 to 200 parts by weight. When the amount of the polymer (B) is less than 0.01 part by weight, the affinity and adhesion with the resin are poor. On the other hand, when it exceeds 900 parts by weight, the blocking prevention property is poor. Further, the polymer (B) is a group having chemical reactivity or ionicity in the molecule and has a functional group (hereinafter, simply referred to as “functional group”) excluding a group containing a polymerizable double bond. In that case, the affinity and adhesion with the resin are further excellent.

Here, the functional group is a carboxyl group,
Examples thereof include functional groups having reactivity such as a hydroxyl group, an N-methylol group, a sulfone group, a maleic anhydride unit, an epoxy group, an amino group, an amide group and a nitrile group.
Preferred functional groups are carboxyl group, hydroxyl group, amino group and amide group.

The average particle size of the composite crosslinked polymer particles of the present invention is 0.01 to 10 μm, preferably 0.01 to 5 μm.
m, and more preferably 0.01 to 2 μm. If the average particle size is less than 0.1 μm, the blocking prevention performance is poor, while if it exceeds 10 μm, the affinity of the resin is poor. The average particle diameter here is measured by the following method.

The average particle size of the crosslinked polymer particles can be measured by
It was carried out by obtaining an average value of particle diameters (100 particles were directly measured by a transmission electron micrograph) (when the particles are not spherical, the long diameter and the short diameter were measured and the average value thereof was obtained).

The glass transition temperature of the above polymer (B) is preferably 200 ° C. or lower, particularly 150 ° C. or lower. The above crosslinked polymer particles (A) and polymerizability (B)
As the crosslinkable monomer used in, the following compound having two or more copolymerizable double bonds such as a non-conjugated vinyl compound typified by divinylbenzene or a polyvalent acrylate compound typified by trimethylene propane trimethacrylate. These are used alone or in combination of two or more.

Specific examples of the crosslinkable monomer include polyethylene glycol diacrylate, 1,3-butylene glycol diacrylate, 1,6-butylene glycol diacrylate, 1,6-hexanelenglycol diacrylate and neopentyl glycol diacrylate. ,
Polypropylene diacrylate, 2,2'-bis (4-
Acryloxyproproxyphenyl) propane, 2,
Diacrylate compounds such as 2'-bis (4-acryloxydiethoxyphenyl) propane, trimethylolpropane triacrylate, trimethylolethane triacrylate, triacrylate compounds such as tetramethylolmethane triacrylate, ditrimethylolpropane tetraacrylate, Tetramethylolmethane tetraacrylate, tetraacrylate compounds such as pentaerythritol tetraacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, polyethylene glycol methacrylate, 1,3-butylene glycol dimethacrylate, 1,4-butylene Glycol dimethacrylate, 1,6-hexane glycol dimethacrylate, Methane compounds such as opentyl glycol dimethacrylate, dipropylene glycol dimethacrylate, polypropylene glycol dimethacrylate, 2,2-bis (4-methacryloxydiethoxyphenyl) propane, trimethylolpropane trimethacrylate, trimethylolethane trimethacrylate, etc. Examples thereof include trimethacrylate compounds, methylenebisacrylamide and divinylbenzene.

Of the above, divinylbenzene, ethylene glycol dimethacrylate, or trimethylolpropane trimethacrylate is preferably used, and divinylbenzene is particularly preferable.

Among the polymerizable monomers other than the crosslinkable monomer, examples of the monomer having no functional group include the following compounds, which may be used alone or in combination of two or more.
Aromatic monovinyl compounds such as styrene, ethylvinylbenzene, α-methylstyrene, fluorostyrene, vinylpyrine, butyl acrylate, 2-ethylhexyl acrylate, β-methacryloyloxyethyl hydrogendiene phthalate, N, N′-dimethylaminoethyl acrylate, etc. Acrylic ester monomer, 2
-Methacrylic acid ester monomers such as ethylhexyl methacrylate, methoxydiethylene glycol methacrylate, methoxypolyethylene glycol methacrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, N, N'-dimethylaminoethyl methacrylate, silicon-modified monomers, macromonomers and the like. Further, conjugated double bond compounds such as butadiene and isoprene, vinyl ester compounds such as vinyl acetate, 4-methyl-1-pentene and other α-olefin compounds can be mentioned.

Among the polymerizable monomers other than the crosslinkable monomer, those having a functional group include mono- or dicarboxylic acid monomers such as acrylic acid, methacrylic acid, maleic acid and itaconic acid, and 2-acryloyloxyethyl-2-. Hydroxyethylphthalic acid, 2-hydroxy-3-phenoxypropyl acrylate, 2-hydroxyethyl methacrylate, N-methylol acrylamide, sodium styrenesulfonate, maleic anhydride,
Glycidyl acrylate, glycidyl methacrylate,
Examples thereof include amide compounds such as acrylamide, methacrylamide, and methylenebisamide; vinyl cyanide compounds such as acrylonitrile and methacrylonitrile. In the present invention, the monomer having a functional group is contained in the monomer constituting the polymer (B) in an amount of 0.05 to 20% by weight, and particularly 0.1 to 15% by weight. It is preferable because it is improved by the dispersibility, adhesion, and the like. Preferred polymerizable monomers are styrene, ethyl vinyl benzene, acrylonitrile, methyl methacrylate, butyl acrylate,
It is a monomer having a functional group.

As a preferable combination of the polymerizable monomers constituting the crosslinkable polymer particles (A), a crosslinkable monomer such as a non-conjugated vinyl compound and a polyvalent methacrylate compound and an aromatic monovinyl compound, an acrylic acid ester monomer and a methacrylic acid ester are used. Examples thereof include a combination with a polymerizable monomer such as a monomer, and a combination of a non-conjugated vinyl compound and an aromatic monovinyl compound is particularly preferable. Further, as a preferable combination of the polymerizable monomers constituting the polymer (B), a non-conjugated vinyl compound, a crosslinkable monomer such as a polyvalent methacrylate compound and an aromatic monovinyl compound, an acrylic acid ester monomer, a methacrylic acid ester monomer, etc. A combination of a polymerizable monomer and a monomer containing a functional group can be mentioned, and a combination of a non-conjugated vinyl compound, an aromatic monovinyl compound and a di- or monocarboxylic acid is particularly preferable.

Next, a preferred method for producing the composite crosslinked polymer particles of the present invention will be described. First, a polymerizable monomer having a crosslinkable monomer content of 27.5 % by weight or more is polymerized, preferably by an emulsion polymerization method to obtain crosslinked polymer particles (A). The average particle size of the crosslinked polymer particles (A) at this time is not particularly limited, and the crosslinkable polymer particles (so as to obtain the target average particle size of the finally obtained composite crosslinked polymer particles ( The average particle diameter of A) is appropriately determined. The average particle diameter of the crosslinked polymer particles (A) can be controlled by the amount of the emulsifier, stirring, and other known methods. In the presence of 100 parts by weight of the crosslinked polymer particles (A), the content of the crosslinkable monomer is less than 10% by weight, and preferably the content of the monomer having a functional group is 0.05 to 20% by weight. By polymerizing 0.01 to 900 parts by weight of a monomer, preferably by a polymerization method such as an emulsion polymerization method, the polymer (B) is appropriately laminated on the entire surface of the crosslinked polymer particles (A) or partially. In the present invention, partially coating the surface of the crosslinked polymer particles with the polymer (B) means that the surface area of the crosslinked polymer particles is less than 100%, preferably 0.00
It indicates that 001% or more and less than 100% is coated with the polymer (B).

The method of adding the polymerizable monomer in the polymerization for obtaining the above-mentioned polymer (B) is preferably a method of adding a part or the whole amount continuously or intermittently. Regarding the method of imparting a functional group to the above polymer (B) by chemical treatment, for example, after obtaining the polymer (B) having an epoxy group, it is treated with ammonia, methylamine or the like. An amino group can be added or a sulfone group can be added by treatment with sodium hydrogen sulfite or sulfuric acid.

The polymerization initiator used in the above-mentioned emulsion polymerization is not particularly limited as long as it can be used in ordinary emulsion polymerization or suspension polymerization, but it is not limited to a particular one such as potassium persulfate, sodium persulfate or ammonium persulfate. The sulfate-based initiator, azo-based initiator, hydrogen peroxide, organic peroxide and the like may be used alone or in combination with various reducing agents such as ascorbic acid.

In the above emulsion polymerization, a suspension protective agent or a surfactant is used in order to enhance the stability of the polymerization reaction system. Usual surfactants can be used, for example, dodecylbenzene sulfonate, dodecyl sulfate, lauryl sulfate, dialkyl sulfosuccinate, polyoxyethylene alkyl phenyl ether sulfate, polyoxyethyne aralkyl propenyl. Examples thereof include anionic surfactants such as phenyl ether sulfate and formalin condensate of naphthalenesulfonic acid. Here, examples of the salt include sodium and ammonium. Furthermore, it is also possible to use nonionic surfactants such as polyoxyethylene nonylphenyl ether, polyethylene glycol monostearate, polyoxyethylene alkylpropenyl phenyl ether, sorbitan monostearate.

Further, it is possible to use a generally known reactive emulsifier such as sodium naphthalenesulfonate alone or in combination with the above-mentioned surfactant. As a preferable suspension protector, water-soluble polymers such as polyvinyl alcohol, polyvinylpyrrolidone, carboxymethyl cellulose, sodium polyacrylate, and hydroxypropyl cellulose can be used. They are,
They may be used alone or in combination. A preferable combination is a combination of an anionic surfactant, a nonionic surfactant and a water-soluble polymer.

When the composite crosslinked polymer particles of the present invention are used for various purposes, they are used in the form of a polymer emulsion, used in the form of a polymer emulsion, and then used in a method of removing the dispersion medium. Recovering polymer particles from the emulsion,
Examples include use in the form of polymer particles.

[0024]

INDUSTRIAL APPLICABILITY Thus, the present invention can provide composite crosslinked polymer particles excellent in affinity with a resin, dispersibility of particles in a resin and blocking resistance.

[0025]

EXAMPLES Examples of the present invention will be described below, but the present invention is not limited thereto. In the following description, "part" means "part by weight" and "%" means "% by weight".

Measuring method of particle diameter The average particle diameter of the composite crosslinked polymer particles is measured by directly measuring 100 particles by a transmission electron micrograph (if the particles are not spherical, the major diameter and the minor diameter are measured). The measurement was carried out and the average value thereof was calculated.

Method of Observing Particle Dispersibility in Resin The dispersibility of the composite crosslinked polymer particles in the resin was determined by kneading the composite crosslinked polymer particles in a methyl methacrylate resin with a generally known ruder and then performing injection molding. The resin plate was observed with a transmission electron microscope to make a visual judgment.

Example 1 As a first step, divinylbenzene (commercial product, purity 55
%, The remaining 40% is ethyl vinyl benzene, the remaining 5%
Is diethylbenzene) 50 parts (pure divinylbenzene parts)
= Corresponding to 27.5 parts) , 50 parts of styrene, 5 parts of sodium dodecylbenzenesulfonate, 0.5 parts of polyvinyl alcohol, 1000 parts of ion-exchanged water, and 1 part of α, α′-azoisobutyronitrile in a reaction vessel. After the preparation, the mixture was homogenized by stirring with a homomixer at 12,000 rpm for 60 minutes. Then, while blowing nitrogen gas, heat to 80 ° C and
Suspension polymerization was carried out by continuing stirring for an hour. Then, subsequently, as a second step, 1 part of potassium persulfate was charged into a reaction vessel, and 70 parts of methyl methacrylate, 20 parts of n-butyl acrylate, 9 parts of methacrylic acid, 1 part of ethylene glycol methacrylate, 40 parts of ion-exchanged water, and dodecylbenzene. An emulsion prepared by mixing 0.5 part of sulfonic acid and 1 part of polyvinyl alcohol was continuously added over 3 hours to complete the polymerization, to produce composite crosslinked polymer particles a. The average particle size of the obtained composite crosslinked polymer particles a was measured and found to be 2.3 μm. When 1 part of the dried composite crosslinked polymer particles was kneaded with 100 parts of methyl methacrylate resin and the dispersibility of the particles was observed, the particles were dispersed with good affinity. In order to check the blocking resistance of the obtained composite crosslinked polymer particles, 0.5 part of the composite crosslinked polymer particles was mixed with 100 parts of polypropylene resin, and then formed into a film having a thickness of 20 μm. After the obtained films were laminated, they were left under a constant load at 50 ° C. for 48 hours. After that, when the film was peeled off, it peeled off easily and the blocking resistance was good.

Example 2 In the first step, 10 polystyrene particles having a weight average molecular weight of 15,000 and an average particle diameter of 0.25 μm were used.
Parts, 5 parts of sodium dodecylbenzenesulfonate, 65 parts of divinylbenzene, 35 parts of styrene, 1 part of sodium persulfate, and 700 parts of ion-exchanged water were charged into a reaction vessel and polymerized at 80 ° C. for 1 hour while stirring while blowing nitrogen gas.
Then, subsequently in the second step, 1 part of styrene, 1 part of methacrylic acid, 0.5 of 2-hydroxyethyl methacrylate.
Parts, and 0.5 parts of sodium persulfate are added, and the mixture is further polymerized at 80 ° C. for 3 hours to complete the polymerization, and thus crosslinked composite polymer particles
Was manufactured. After drying the obtained composite crosslinked polymer particles,
When the dispersibility of the particles kneaded with the methyl methacrylate resin was observed, the particles were found to be dispersed with good affinity. The resulting composite crosslinked polymer particles had good blocking resistance.

Example 3 In the second step of Example 2, 0.5 part of potassium persulfate was charged into a reaction vessel, and 100 parts of styrene, 50 parts of methyl methacrylate and 43 parts of n-butyl acrylate were used.
Parts, 7 parts of acrylic acid, 3 parts of ethylene glycol methacrylate, 40 parts of ion-exchanged water, 0.5 parts of dodecylbenzene sulfonic acid were continuously added for 3 hours to complete the polymerization, thereby completing the cross-linked polymer particles c. Was manufactured. The average particle size of the obtained composite crosslinked polymer particles c was measured and found to be 0.7 μm. The resulting composite polymer particles were dried and then kneaded in a methyl methacrylate resin, and the dispersibility of the particles was observed. As a result, the particles were dispersed with good affinity. Furthermore, composite crosslinked polymer particles c
When a cross section of the particles was observed by a transmission electron microscope by a commonly known method, it had a composite structure. The resulting composite crosslinked polymer particles had good blocking resistance.

Example 4 In the second step of Example 2, 0.5 part of potassium persulfate was charged into a reaction vessel, and 95 parts of styrene and 5 parts of glycidyl methacrylate were continuously added over 2 hours to complete the polymerization. . Then, the reaction temperature was cooled to 70 ° C., ammonia was added until pH 11 was reached, and then 2
The reaction was carried out for 4 hours to obtain composite crosslinked polymer particles d. After the obtained composite crosslinked polymer particles d were purified, the infrared absorption spectrum of the composite crosslinked polymer particles d was taken and the presence of amino groups could be confirmed. The average particle size of the obtained composite crosslinked polymer particles d was measured and found to be 0.6 μm. The resulting composite crosslinked polymer particles a were dried and then kneaded into a methyl methacrylate resin, and the dispersibility of the particles was observed. As a result, the particles were dispersed with good affinity. The resulting composite crosslinked polymer particles d had good blocking resistance.

[0032]

Comparative Example Crosslinked polymer particles e consisting only of the polymer (A) obtained by carrying out the first step in Example 2 were obtained. The average particle diameter of the obtained crosslinked polymer particles e was measured and found to be 0.58 μm. After drying the resulting crosslinked polymer particles, kneading into a methylmethacrylate resin and observing the dispersibility of the particles, the particles were highly agglomerated and the dispersibility was poor. The blocking resistance of the crosslinked polymer particles was not sufficient.

[0033]

The composite crosslinked polymer particles of the present invention are excellent in affinity with a resin, dispersibility in a resin and blocking resistance.

─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Nobuyuki Ito 2-11-24 Tsukiji, Chuo-ku, Tokyo Japan Synthetic Rubber Co., Ltd. (56) Reference JP-A-4-363313 (JP, A) JP-A 64-26617 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C08L 51/00-51/04 C08F 265/00-291/00 C08F 2/44

Claims (2)

(57) [Claims] 1. The surface of crosslinked polymer particles (A) obtained by polymerizing a polymerizable monomer having a crosslinkable monomer content of 27.5 % by weight or more has a crosslinkable monomer content of 10%.
The polymer (B) obtained by polymerizing less than wt% of a polymerizable monomer is partially or entirely coated, and the weight ratio of (A) / (B) is 100 / 0.01 to 900.
Part by weight, average particle diameter is 0.01 to 10 μm, composite crosslinked polymer particles. 2. The content of the crosslinkable monomer is 10 parts by weight in the presence of 100 parts by weight of the crosslinked polymer particles (A) obtained by polymerizing the polymerizable monomer having the content of the crosslinkable monomer of 27.5 % by weight or more. Less than 0.01% by weight of polymerizable monomer
A method for producing composite crosslinked polymer particles, characterized in that the polymerization is carried out at about 900 parts by weight.