JPH07206912A - Complex crosslinked polymer particle and its production - Google Patents

Abstract

PURPOSE:To obtain the subject polymer particles capable of improving strength and heat resistance of the resin and having good blocking preventing properties, smoothness and dispersibility by polymerizing a polymerizable monomer containing a crosslinkable monomer in a specific amount in the presence of crosslinked polymer particles. CONSTITUTION:(B) 0.01-900 pts.wt. of a mixture of a polymerizable monomer (e.g. styrene) containing >=10wt.% of a crosslinkable monomer (e.g. divinylbenzene) is polymerized in the presence of (A) 100 pts.wt. of polymer particles obtained by polymerizing a polymerizable monomer having <10wt.% of a crosslinkable monomer (e.g. ethylene glycol dimethacrylate) content in a deionized water of a surfactant (e.g. sodium dodecylbenzene sulfonate) at 80 deg.C for 3hr to provide the objective polymer particles. In the particles, the surface of polymer particles (A) is partially or fully coated with the polymer (B) obtained by polymerizing the polymerizable monomer and a weight ratio of the components A/B is 100/0.01-900 pts.wt. and the average particle diameter is 0.01-10mum.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crosslinked polymer particle which improves the mechanical properties and heat resistance of a resin and is excellent in antiblocking property, slipperiness and dispersibility of a resin film, and a method for producing the same.

[0002]

2. Description of the Related Art Polymer particles having a particle size in the range of 0.1 to 10 .mu.m are used as a resin mechanical property improving agent, a resin film anti-blocking agent, a film slippery agent, a spacer, standard particles, and an antigen-antibody reaction test. It is useful and used as particles, running stability stabilizer for thermal paper, toner additive, cosmetic additive, rheology control agent, low-shrinking agent and the like. The crosslinked polymer particles in this range can be usually produced by a suspension polymerization method. Further, it can be produced by an emulsion polymerization method (JP-A-1-315454).
However, when these particles are mixed with resin, the mechanical properties are improved, but the impact resistance is reduced, and during resin molding, the particles spill out, and the stain in the mold is remarkable, and the resin film When the film was added to the film, particles were spilled from the resin film during film stretching, and the particles were scattered on the resin film to cause dusting, resulting in deterioration of quality. These are phenomena that occur due to lack of elasticity of particles, affinity with resin, and dispersibility in resin.
In order to improve the elasticity of the particles, a method of adding a rubber-like polymer has been used, but this does not give a sufficient improving effect, and if used in a large amount, the mechanical properties of the resin deteriorate and heat resistance There was a problem of decrease of. Therefore, there has been a demand for crosslinked polymer particles that solve these problems.

[0003]

SUMMARY OF THE INVENTION The present invention has been made against the background of the conventional technical problems, and improves the mechanical properties and heat resistance of resins with little deterioration in impact resistance and quality due to dusting. It is intended to provide crosslinked polymer particles which are excellent in antiblocking property, slipperiness and dispersibility.

[0004]

The present invention will be described in detail below. In the present invention, the surface of polymer particles (A) is partially or entirely coated with a polymer (B) obtained by polymerizing a polymerizable monomer having a crosslinkable monomer content of 10% by weight or more, and The weight ratio of (A) / (B) is 100 / 0.01 to 900 parts by weight, and the average particle diameter is 0.0.
In the presence of 100 parts by weight of composite crosslinked polymer particles characterized by having a size of 1 to 10 μm and polymer particles (A) obtained by polymerizing less than 10% by weight of a polymerizable monomer. The present invention provides a method for producing composite crosslinked polymer particles, which comprises polymerizing 0.01 to 900 parts by weight of a polymerizable monomer in an amount of 10% by weight or more.

In the present invention, the polymer particles (A)
Is a suspension polymerization or dispersion of a polymerizable monomer having a content of the crosslinkable monomer having two or more groups having a polymerizable double bond in the molecule (hereinafter, simply referred to as "crosslinkable monomer") is less than 10% by weight. Polymerization, emulsion polymerization, preferably particles obtained by polymerization by an emulsion polymerization method, and also existing polystyrene latex, polybutadiene latex, styrene-butadiene copolymer latex, acrylic ester latex, acrylic ester copolymer latex. , Or any other known latex can be substituted.

The content of the crosslinkable monomer in the polymerizable monomer used in the polymer (B) is 10% by weight or more, preferably 25% by weight or more, more preferably 30% by weight or more. If the content of the crosslinkable monomer is less than 10% by weight, the antiblocking property is poor.

The amount of the polymer (B) laminated partially or entirely on the surface of the polymer particles (A) is 0.01 to 900 parts by weight, preferably 0.1 part by weight per 100 parts by weight of (A).
It is 1 to 400 parts by weight, more preferably 0.5 to 200 parts by weight. If the amount of (B) is less than 0.01 parts by weight, the affinity and adhesion with the resin will be poor. On the other hand, if it exceeds 900 parts by weight, the impact resistance decreases. 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,
It is at least one selected from reactive functional groups 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. As a preferred functional group, a carboxyl group,
A hydroxyl group, an amino group, and an 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 50 ° C. or higher, particularly 100 ° C. or higher.
As the crosslinkable monomer used in the polymer particles (A) and the polymer (B), there are two crosslinkable monomers such as a non-conjugated vinyl compound typified by divinylbenzene or a polyvalent acrylate compound typified by trimethylenepropanetrimethacrylate. The following compounds having the above-mentioned copolymerizable double bond may be mentioned, and these may be 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-hexanelen glycol 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, acrylon tolyl methyl methacrylate, butyl acrylate, monomers having functional groups.

A preferred combination of the polymerizable monomers constituting the polymer particles (A) is a non-conjugated vinyl compound,
Examples thereof include a combination of a crosslinkable monomer such as a polyvalent methacrylate compound and an aromatic monovinyl compound, an acrylic acid ester monomer, a methacrylic acid ester monomer or the like polymerizable monomer and a monomer having a functional group, and particularly, a non-conjugated vinyl compound. Preferred is the combination of a vinyl aromatic compound with a di- or monocarboxylic acid. 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 with a polymerizable monomer can be mentioned, and a combination of a non-conjugated vinyl compound and an aromatic monovinyl compound 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 is polymerized by a polymerization method such as emulsion polymerization, suspension polymerization and dispersion polymerization, preferably an emulsion polymerization method, to obtain polymer particles (A). Regarding the average particle diameter of the polymer particles (A) at this time,
It is not particularly limited, so that the target average particle size of the finally obtained composite crosslinked polymer particles can be obtained,
The average particle diameter of the (A) is appropriately determined. The average particle size of the 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 polymer particles (A), 0.01 to 9 polymerizable monomers containing 10% by weight or more of the crosslinking monomer.
By polymerizing 00 parts by weight by emulsion polymerization, suspension polymerization, dispersion polymerization, preferably emulsion polymerization, the polymer (B) is obtained.
Is partially or entirely laminated on the surface of (A). In the present invention, partially coating the surface of the polymer particles with the polymer (B) means that the surface area of the polymer particles is less than 100%, preferably 0.00001% or more.
It shows that less than 00% is coated with the polymer (B).

The preferred method of adding the polymerizable monomer in the polymerization for obtaining the above-mentioned polymer (B) is a method of continuously or intermittently adding a part or the whole amount. 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. Examples thereof include conversion to an amino group, or conversion to a sulfone group by treatment with sodium hydrogen sulfite or sulfuric acid.

The polymerization initiator used in the above polymerization is not particularly limited as long as it can be used in ordinary emulsion polymerization, dispersion polymerization and suspension polymerization, but potassium persulfate, sodium persulfate, ammonium persulfate, etc. The persulfate-based initiator, azo-based initiator and 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 polymerization, a suspension protector or a surfactant may not be used in some cases, but a suspension protector 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, polyoxyethylene alkyl propenyl phenyl ether. Examples thereof include anionic surfactants such as sulfates and formalin condensates 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 dispersion liquid of the composite crosslinked polymer particles obtained by the above method is used for various purposes, the dispersion liquid is used in the form of the dispersion liquid, and is added in the form of the dispersion liquid. And then used in the method of removing the dispersion medium. For example, the composite crosslinked polymer particles are recovered from the dispersion and used in the form of the composite crosslinked polymer particles.

[0023]

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.

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 microscope photograph (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 with a methyl methacrylate resin by a generally known ruder and then performing injection molding. The resin plate was observed with a transmission electron microscope to make a visual judgment.

[0026]

[Evaluation of physical properties of resin composition] General-purpose polystyrene ("Dialex HF-77" manufactured by Mitsubishi Monsanto Co., Ltd.) and Examples and Comparative Examples were used. The composite crosslinked polymer particles and the polymer particles were mixed in a tumbler in a composition ratio shown in Table 1, and then a twin-screw extruder (Ikegai PC, "Ikegai PC"
H45II '') was melt-mixed and pelletized. Molding temperature 300 ℃, mold temperature 80 ℃ using this pellet
Various test pieces were obtained by injection molding under the conditions of. Each physical property value measured as follows using this test piece is shown in Table 1. Izod impact strength: Measured with a notch according to ASTM D256. Heat distortion temperature: measured at 264 psi according to ASTM D648. Tensile strength: Tensile speed 50mm according to ASTM D638
It was measured in minutes. Bending strength: Bending strength of 15 mm according to ASTM D790
It was measured in minutes.

[0027]

[Table 1]

Example 1 62 parts of styrene, 10 parts of methyl methacrylate, 20 parts of n-butyl acrylate, 5 parts of acrylic acid, 3 parts of ethylene glycol dimethacrylate, 40 parts of deionized water,
Dodecylbenzene sulfonic acid 1.5 parts, polyvinyl alcohol 0.5 part, ion-exchanged water 1000 parts, α-α'-
1 part of azoisobutyronitrile was charged into a reaction vessel and homogenized with a homomixer at 13,000 rpm for 80 minutes. Next, while blowing nitrogen gas, the mixture was heated to 80 ° C. and stirred for 3 hours to carry out suspension polymerization to obtain polymer particles (A). Then, as a second step, 1 part of potassium persulfate is charged into the reaction vessel, and 50 parts of divinylbenzene, 50 parts of styrene, 5 parts of sodium dodecylbenzenesulfonate, and 1000 parts of ion-exchanged water are mixed to prepare an emulsion for 3 hours. Was continuously added over the course of polymerization to produce composite crosslinked polymer particles a. As divinylbenzene, a commercially available product having a purity of 81 ° C., a residual 18% of ethylvinylbenzene, and a residual 1% of impurities was used. When the average particle diameter of the obtained composite crosslinked polymer particles a (hereinafter, this divinylbenzene was used) was measured, it was 1.9 μm for the polymer particles (A) and 2.1 μm after the completion of the polymerization. The resulting crosslinked polymer particles were dried and kneaded into a methylmethacrylate resin, and the dispersibility of the particles was observed. As a result, the particles were well dispersed. The characteristics of the resin composition are shown in Table 1. The mechanical properties and heat resistance were sufficient, and the impact resistance did not decrease. In addition, blending crosslinked polymer particles with polypropylene resin,
The blocking resistance of the film was good.

Example 2 10 parts of polystyrene particles having a weight average molecular weight of 15,000 and an average particle diameter of 0.25 μm, sodium dodecylbenzenesulfonate 0.5 part, and methacrylic acid 2
Parts, 3 parts of divinylbenzene, 45 parts of styrene, 50 parts of n-butyl acrylate, 1 part of sodium persulfate and 700 parts of ion-exchanged water are charged into a reaction vessel and polymerized by stirring at 80 ° C. for 1 hour while stirring while blowing nitrogen gas. Particles (A) were obtained. Then continue to divinylbenzene 65
Part, 35 parts of styrene, and 0.5 part of sodium persulfate were added, and the mixture was further polymerized at 80 ° C. for 3 hours to complete the polymerization to produce composite crosslinked polymer particles b. Divinylbenzene is a commercial product with a purity of 56% and the remaining 38%.
Was ethyl vinylbenzene, and the remaining 6% was an impurity. The average particle size of the obtained composite crosslinked polymer particles b was measured, and it was found that the polymer particles (A) had a particle size of 0.5 μm
And was 0.6 μm after completion of the polymerization. The resulting crosslinked polymer particles were dried and then kneaded into a methylmethacrylate resin, and the dispersibility of the particles was observed. As a result, the particles were dispersed therein. The characteristics of the resin composition are shown in Table 1.
The mechanical properties and heat resistance were sufficient, and the impact resistance did not decrease. Moreover, when the cross-linked polymer particles were blended with a polypropylene resin and the blocking resistance of the film was observed, it was good.

Example 3 The same procedure as in Example 2 was carried out except that divinylbenzene 65 parts and styrene 35 parts were used instead of divinylbenzene 3 parts and styrene 3 parts in the same manner as in Example 2, and composite crosslinked polymer particles c were obtained. Obtained. The average particle size of c was 0.51 μm. The resulting crosslinked polymer particles c were dried and then kneaded into a methylmethacrylate resin, and the dispersibility of the particles was observed. As a result, the particles were well dispersed. Further, when the crosslinked polymer particles c were blended with a polypropylene resin and the blocking resistance of the film was observed, it was good.

Comparative Example 1 The polymer particles (A) in Example 2 were obtained, and were obtained as polymer particles d. The average particle size of (A) is 0.5 μm
Met. After drying the resulting polymer particles d and kneading in a methyl methacrylate resin and observing the dispersibility of the particles, the particles were aggregated and the dispersibility was poor. The characteristics of the resin composition are shown in Table 1. The mechanical properties were not sufficient and the heat resistance and impact resistance decreased. Also, the blocking resistance was not sufficient.

[0032]

EFFECT OF THE INVENTION It can be used and has extremely high industrial value. The composite crosslinked polymer particles of the present invention have improved mechanical properties and heat resistance, and are excellent in antiblocking property, slipperiness and dispersibility of the resin film. Therefore, it is extremely useful as a modifier for various applications.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Nobuyuki Ito 2-11-24 Tsukiji, Chuo-ku, Tokyo Japan Synthetic Rubber Co., Ltd.

Claims (2)

[Claims] 1. The surface of polymer particles (A) is partially or entirely coated with a polymer (B) obtained by polymerizing a polymerizable monomer having a crosslinkable monomer content of 10% by weight or more, And the weight ratio of (A) / (B) is 100/0.
01 to 900 parts by weight, average particle size 0.01 to 10 μm
The composite crosslinked polymer particles are characterized by: 2. The content of the crosslinkable monomer is 10% by weight in the presence of 100 parts by weight of the polymer particles (A) obtained by polymerizing the polymerizable monomer in which the crosslinking monomer is less than 10% by weight.
A method for producing composite crosslinked polymer particles, which comprises polymerizing 0.01 to 900 parts by weight of the polymerizable monomer.