JPH08183807A - Resin particle, preparation thereof, and use thereof - Google Patents

Abstract

PURPOSE: To obtain (meth)acrylic polymer particles high in heat stability, little in particle size dispersion, stable in surface properties and suitably usable as a blocking-proofing agent for a resin film, etc., by suppressing formation of fine by-product particles attributed to concurrent emulsion polymn., and separating and recovering the resulting resin particles from a suspension medium by a simple operation. CONSTITUTION: (A) a polymerizable monomer component mainly comprising a (meth)acrylic monomer is subjected to water-based suspension polymn. in the presence of (B) a substantially water-insoluble compd. difficultly soluble in the polymerizable monomer component (A) to obtain a suspension of spherical particles of 1 to 100μm in an average particle size, to which (C) water-insoluble fine particles are then added to effect mutual coagulation of the spherical particles, which is then separated from the suspension medium. The compd. (B) is one having at least 1 structural unit selected from the group consisting of -SH, -S-S-, -COOH, -NO2 , and -OH. The water-insoluble fine particles (C) are selected from among a variety of either org. or inorg. fine particles, and are especially those having a hydrophobicity index of at least 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to resin particles, a method for producing the same, and uses thereof. More specifically, the present invention relates to a technique for easily and stably providing (meth) acrylic resin particles having a narrow particle size distribution and containing no heavy metal by a suspension polymerization method. Further, the present invention is, for example, a problem such as generation of voids and deterioration of operability due to contamination of dies or nozzles when film-forming or molding is performed by blending suspension-polymerized resin particles in a resin matrix such as a polyolefin-based polymer. The present invention relates to resin particles capable of suppressing the occurrence of

[0002]

2. Description of the Related Art (Meth) acrylic resin particles, especially those having an average particle diameter of about 0.1 to 500 .mu.m, include, for example, anti-blocking agents for resin films, additives for toners for electrostatic image development, powders. It is expected to find applications in applications such as paints and water-dispersed paints, additives for decorative boards, additives for artificial marble, packings for cosmetics, and column packings for chromatography.

Conventionally, as a method for producing resin particles, there have been known methods such as mechanical pulverization, suspension polymerization and emulsion polymerization. Among them, the method by mechanical pulverization requires a large amount of energy for pulverization, and further requires a multi-stage classification treatment in order to obtain fine particles having a uniform particle size. Further, since the fine particles obtained by this method are of irregular shape, problems remain in fluidity, aggregation resistance and the like. Further, the method by emulsion polymerization can obtain fine particles having a uniform particle diameter, but the obtained fine particles have a particle diameter of 0.
Since it is about 1 μm, it cannot be directly used for the above-mentioned applications. On the other hand, the suspension polymerization method is one in which suspension particles of a monomer are prepared and polymerized by mechanical stirring, so that resin particles having a desired particle diameter can be obtained relatively easily, and a solvent is used. It has advantages such as no use and easy reaction control.

However, it is known that during suspension polymerization, fine particles are secondarily formed by emulsion polymerization in the aqueous phase. Therefore, the yield is lowered, the polymerization stability is lowered, and the emulsion-polymerized fine particles thus formed are often attached to the interface of the suspension-polymerized particles and are difficult to completely remove. This will result in deterioration of the physical properties of the particles. In particular, the resin particle size to be obtained by suspension polymerization is made finer, for example, 0.1 to 500 μm.
When the amount of the dispersion stabilizer is small, the amount of the dispersion stabilizer added to the aqueous phase in order to stabilize the suspended fine particles is larger than that in the general suspension polymerization. In the process, the amount of the polymerizable monomer dissolved in the aqueous phase increases, and such by-production of fine particles by emulsion polymerization poses a problem.

In the suspension polymerization method, it is known to add an inorganic water-soluble inhibitor to the system as a method for preventing emulsion polymerization which occurs concurrently in the aqueous phase. For example, in JP-A-55-82125, 0.01 to 0.01
It is also possible to add 10% by weight of a water-soluble inhibitor such as ammonium thiocyanate and cupric chloride.
No. 302 discloses addition of vanadium pentoxide and / or cupric chloride together with a dispersion stabilizer, and JP-A No. 62-205108 discloses that sodium nitrite, potassium nitrite, cupric chloride, etc. It is disclosed in JP-A-2-284905 that such a water-soluble inhibitor can be dissolved in water in an amount of 10 ppm or more based on the total amount of vinyl monomers, and a polymerization initiator comprising a water-soluble inhibitor such as nitrite and an organic peroxide. It is further known that suspension polymerization is carried out using
No. 237105 discloses that suspension polymerization is carried out in a continuous aqueous phase containing water, a water-miscible organic solvent and a water-soluble polymerization inhibitor such as sodium nitrite and hydroquinone.

Further, as disclosed in JP-A-61-255323, a technique of adding a water-soluble mercaptan compound in order to prevent concurrent emulsion polymerization in aqueous suspension polymerization is known. The water-soluble mercaptan compound includes 2-mercaptoethanol, thioglycolic acid, cysteine, glutathione, dimercaprol, 1,4-dithiothreitol, dimercaptosuccinic acid, and 2,3-dimercapto-1-propanesulfonic acid. Etc. are disclosed.

Further, in Japanese Patent Laid-Open No. 52-102391,

[0008]

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About 0.0005 to about 0.02 part by weight of a water-soluble inhibitor selected from borohydrides, alkali metal nitrites, alkaline earth metal nitrites or ammonium nitrite represented by 100 parts by weight of the monomer. Parts, it is disclosed that about 0.0001 to about 0.005 part by weight of an oil-soluble inhibitor consisting of oil-soluble and alcohol-soluble nigrosine is added.

Further, JP-A-5-61253 discloses that water-soluble nigrosine is added to carry out suspension polymerization.

Further, in Japanese Patent Application Laid-Open No. 5-93005, at least the dispersed phase composed of a polymerizable monomer and the continuous phase are held in independent tanks, respectively, and passed through independent paths,
Both are fed to the granulator once or twice or more at a controlled ratio to obtain a suspension having polymerizable droplets of the desired size, which is then introduced into the polymerization tank. In a suspension polymerization method in which the polymerization is completed to obtain a polymer, it is disclosed that a continuous layer contains a metal complex compound of a monoazo dye represented by the following general formula.

[0012]

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However, even if an inorganic water-soluble inhibitor is added during suspension polymerization of the (meth) acrylic monomer, its emulsion polymerization preventing effect is weak and it is necessary to add a large amount. Especially, the smaller the particle size of the fine particles to be obtained by suspension polymerization, the more remarkable this tendency.

When a water-soluble mercaptan compound is used to prevent concurrent emulsion polymerization, an offensive odor adheres to the resin particles or the waste water obtained due to the mercaptan compound, and this offensive odor is easy to wash. It could not be removed.

Further, the use of a borohydride as the water-soluble inhibitor makes it difficult to handle the compound itself, and requires strict control of suspension polymerization conditions and the like.

Further, even when suspension polymerization is carried out by adding water-soluble nigrosine, the effect of preventing emulsion polymerization is weak, and the amount of addition is large, so that there is a problem that the charging characteristics are likely to touch positively. It was

Further, when a metal complex compound of a monoazo dye is used, a heavy metal such as chromium will be contained in the polymerization system and further in the obtained resin particles, which is a problem from the viewpoint of environmental resistance and safety. there were.

Incidentally, the (meth) acrylic resin particles can be used for various purposes as described above. For example, when they are used as an antiblocking agent for resin films, they are added as desired properties. It has similar refractive index to that of the resin system and good heat resistance. Hereinafter, this point will be described in more detail.

The polyolefin film is used as a packaging material for packaging various articles including foods. When the films are laminated, the films adhere to each other, so-called blocking occurs, and the workability of packaging is remarkably improved. It has the drawback of lowering it. Conventionally, as a means for preventing blocking in a polyolefin film and improving slipperiness, a method of uniformly mixing fine particles of an inorganic material such as silica or talc into the film is generally carried out. In order to impart sufficient blocking resistance and slipperiness to the polyolefin film by using, it is necessary to mix a large amount of an inorganic substance, and when a polyolefin film mixed with an inorganic substance is stretched, a void is formed around the inorganic substance. Occurs,
There has been a problem that the transparency and mechanical strength of the film are deteriorated.

It has been proposed to use polyamide fine powder or condensed resin spheres having a triazine ring instead of the above-mentioned inorganic substances. The method of using fine polyamide powder is effective in preventing the decrease in transparency, but since a large amount of mixing is required, the strength of the obtained film decreases, and the cost also increases. Further, the method of using a spherical body of a condensation type resin having a triazine ring has a difference in refractive index between the polyolefin and the condensation type resin having a triazine ring, and there is a problem in preventing deterioration of transparency. The unreacted volatile matter such as formalin remaining in the mold resin has a drawback that the transparency or mechanical strength of the film is lowered because voids are formed during the stretching treatment. Further, when such resin particles are blended, if the heat resistance of the resin particles is not sufficient, the resin particles are decomposed during the melt kneading of the film resin, and odor is generated due to the decomposed components and the formation of voids occurs, and the environment Since there is a risk of contamination and deterioration of mechanical and optical properties, improvement of heat resistance has been desired.

From such a viewpoint, the present inventors first
In order to suppress emulsion polymerization that occurs concurrently when performing aqueous suspension polymerization of a polymerizable monomer containing a (meth) acrylic monomer as a main component, -SH, -SS-, -COOH, -NO
_A compound having at least one structural unit selected from the group consisting of ₂ and —OH, which is substantially insoluble in water and hardly soluble in the polymerizable monomer, is used in the aqueous suspension polymerization. It has been proposed to allow it to exist (Japanese Patent Laid-Open No. Hei 6)
-73106). The (meth) acrylic polymer resin particles obtained by carrying out suspension polymerization in the presence of such a compound have a narrow particle distribution and are extremely excellent in heat resistance stability as compared with conventional ones. Since it was a thing, for example,
It could be expected to be used as an antiblocking agent for resin films such as polyolefins.

When the (meth) acrylic polymer resin particles are used as an anti-blocking agent, the transparency and mechanical properties of the obtained film are higher than those when conventionally used inorganic or condensation type resin particles are used. The mechanical strength has been improved, and the occurrence of defects such as the occurrence of voids and reduced operability has been greatly reduced. However, there is still room for improvement in terms of generation of voids and operational stability.

[0023]

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide an improved resin particle, a method for producing the same, and various uses to which the resin particle is applied. Another object of the present invention is to provide resin particles having excellent physical properties obtained by suspension polymerization of a polymerizable monomer containing a (meth) acrylic monomer as a main component, and a method for producing the same. . Another object of the present invention is to provide suspension-polymerized resin particles in which the presence of by-product fine particles due to emulsion polymerization is small and a method for producing the same. Another object of the present invention is to provide (meth) acrylic resin particles having a narrow particle size distribution and containing no heavy metal simply and stably by a suspension polymerization method.
Further, the present invention is, for example, a problem such as generation of voids and deterioration of operability due to contamination of dies or nozzles when film-forming or molding is performed by blending suspension-polymerized resin particles in a resin matrix such as a polyolefin-based polymer. It is an object of the present invention to provide resin particles capable of suppressing the occurrence of

[0024]

[Means for Solving the Problems]
The polymerizable monomer (A) containing a (meth) acrylic monomer as a main component is converted into -SH, -SS-, -COOH, -NO.
A compound (B) having at least one structural unit selected from the group consisting of ₂ and —OH, which is substantially insoluble in water and hardly soluble in the polymerizable monomer (A). Obtained by carrying out aqueous suspension polymerization in the presence of 1 to 100 μm.
A method for producing resin particles, characterized in that water-insoluble fine particles (C) are added to a suspension of spherical particles having an average particle diameter of m, the spherical particles are aggregated and separated from a suspension medium. Achieved by

As the compound (B), especially -S
H, -S-S -, - COOH, be a structural unit selected from the group consisting of -NO ₂ and -OH are those having two or more is desired. Further, the addition amount of the compound (B) is
20 to 0.0001% by weight based on the polymerizable monomer (A)
Is desired.

The water-insoluble fine particles (C) preferably have a hydrophobicity index of 5 or more.

In the present invention, it is also preferable that an organic solvent which is a non-solvent is added to the resin of the resin particles when the resin particles are aggregated.

Further, the above-mentioned various objects are obtained by adding -S to the polymerizable monomer (A) containing a (meth) acrylic monomer as a main component.
H, —S—S—, —COOH, —NO ₂ and —OH having at least one structural unit selected from the group consisting of, and substantially insoluble in water and the polymerizable monomer ( Aqueous suspension polymerization is carried out in the presence of the compound (B) which is hardly soluble in A), and the water-insoluble fine particles (C) are added to the resulting suspension of spherical particles having an average particle size of 1 to 100 μm. It is also achieved by resin particles obtained by aggregating the spherical particles with each other and separating them from the suspension medium.

The resin particles have a contact angle with water of 60.
Or more and a wetting rate with water of 30 seconds or more, a contact angle with liquid paraffin of 15 ° or less and a wetting rate of liquid paraffin of 70 seconds or less, and 40 at 270 ° C. in air. It is desired that the decomposition rate of the organic component when kept for a minute is 60% by weight or less. The resin particles have an average particle diameter of 0.1 to 5
It is preferably 00 μm. The resin particles can have a refractive index of about 1.45 to 1.55.

The present invention also provides a polyolefin-based polymer composition obtained by blending the above resin particles with a polyolefin. The amount of resin particles blended with the polyolefin is 0.0
Amounts of about 01 to 40% by weight are suitable.

[0031]

The emulsion polymerization, which occurs concurrently with the aqueous suspension polymerization of the polymerizable monomer containing the (meth) acrylic monomer as the main component, occurs mainly at the interface of the suspended particles. When the compound (B) having a specific structural unit, which is substantially insoluble in water and hardly soluble in the polymerizable monomer is allowed to exist during the aqueous suspension polymerization, the aqueous suspension polymerization In the above, the compound (B) can be efficiently arranged at the interface of the suspended particles, whereby the emulsion polymerization occurring at the interface of the suspended particles can be effectively suppressed.

On the surface of the spherical particles obtained by this suspension polymerization, the compound (B) was added in a very small amount.
It is considered that there is a functional group due to the presence of this functional group, and when the spherical particles are blended with a resin such as polyolefin for film formation or molding, the occurrence of voids and die In addition, problems such as reduced operability due to nozzle contamination may occur.

However, after the suspension polymerization is completed,
Further, water-insoluble fine particles (C) are added to the suspension of the spherical particles.
When the resin particles are obtained by aggregating the spherical particles with each other and separating them from the suspension medium, not only the separation operation becomes simple, but surprisingly, the surface functional groups as described above are added. The occurrence of defects that may be caused was suppressed.

Hereinafter, the present invention will be described in detail based on embodiments.

The polymerizable monomer (A) used in the present invention contains a (meth) acrylic monomer as a main component, preferably 50 to 100% by weight of a (meth) acrylic monomer, more preferably Is contained in an amount of 60 to 100% by weight. When the blending ratio of the (meth) acrylic monomer in the polymerizable monomer (A) is extremely low, the emulsion polymerization inhibiting effect of the compound (B) described below cannot be expected so much. From this point, it is further desired that the SP (solubility parameter) value of the polymerizable monomer (A) is 9.0 or less.

Examples of (meth) acrylic monomers include acrylic acid, methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, dodecyl acrylate, stearyl acrylate, 2-ethylhexyl acrylate, and acrylic. Tetrahydrofurfuryl acid, methacrylic acid, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, etc. Can be mentioned,
Of course, it is not limited to these. It is also possible to use a combination of a plurality of these (meth) acrylic monomers.

Further, in order to obtain resin particles having a crosslinked structure between molecules, a (meth) acrylic monomer having a plurality of polymerizable double bond groups in the molecule is copolymerized with the above (meth) acrylic monomer. It is possible to As such a crosslinkable (meth) acrylic monomer,
Trimethylolpropane triacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, decaethylene glycol dimethacrylate, pentadecaethylene glycol dimethacrylate, pentacontahector ethylene glycol dimethacrylate, dimethacrylate Methacrylic acid 1,3
-(Meth) acrylic monomers such as butylene, allyl methacrylate, trimethylolpropane trimethacrylate, pentaerythritol tetramethacrylate, and diethylene glycol dimethacrylate phthalate are mentioned, and it is possible to use them in combination. . In addition, aromatic divinyl compounds such as divinylbenzene, divinylnaphthalene, and their derivatives, N, N-divinyl, etc. within a range that does not hinder the mixing ratio of the (meth) acrylic monomer in the polymerizable monomer (A). Crosslinking agents such as aniline, divinyl ether, divinyl sulfide, divinyl sulfonic acid, etc., and further polybutadiene, polyisoprene unsaturated polyester and JP-B-57-5.
6,507, JP-A-59-221,304, JP-A-59-221,305, JP-A-59-
It is also possible to use the reactive polymers described in JP-A-221,306, JP-A-59-221,307 and the like.

On the other hand, the other monomer that can be contained in the polymerizable monomer (A) used in the present invention may be any one that is copolymerizable with the above-mentioned (meth) acrylic monomer, For example, styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-methoxystyrene, p-tert-butylstyrene, p-phenylstyrene, o-chlorostyrene, m-chlorostyrene, Examples thereof include styrene-based monomers such as p-chlorostyrene, ethylene, propylene, butylene, vinyl chloride, vinyl acetate, acrylonitrile, acrylamide, methacrylamide, and N-vinylpyrrolidone.

In the method for producing resin particles of the present invention,
In the aqueous suspension polymerization of the polymerizable monomer (A) as described above, the compound (B) which is substantially insoluble in water and hardly soluble in the polymerizable monomer (A) is added. Add to suspension polymerization system.

As described above, the compound (B) used in the present invention is substantially insoluble in water and hardly soluble in the polymerizable monomer (A). In the above, the compound (B) is present at the interface of suspended particles due to the action of a dispersion stabilizer such as a surfactant, which will be described later, added to the suspension polymerization system, and the emulsification that occurs at the interface of suspended particles. Effectively suppress polymerization. When the solubility of the compound (B) in water is high, during the suspension polymerization, the compound (B) migrates to the continuous aqueous phase and emulsion polymerization cannot be prevented. Suspended particles (monomers) with high solubility in the monomer (A)
In particular, chain transfer is likely to occur, and the degree of polymerization of the resulting resin particles does not increase.

Further, the solubility of the compound (B) in water is preferably 0 to 1% by weight, more preferably 0 to 0.1% by weight under the conditions of 25 ° C. ± 5 ° C. and 760 Torr. On the other hand, the solubility in the polymerizable monomer (A) is 25 ° C ± 5 ° C, 760
Under the conditions of Torr, 0 to 50% by weight, more preferably 0.01 to 20% by weight, still more preferably 0.01.
It is preferably about 10 to 10% by weight.

Examples of the compound (B) satisfying the solubility in water and the polymerizable monomer (A) are, for example, -SH, -SS-, -COOH, -NO ₂ and -SH.
Those having at least one structural unit selected from the group consisting of OH are preferably used.

Specific examples of the compound having a -SH group include thiocresol, trimethylolpropane trithioglycolate, dithiohydroquinone, xylenedithiol and 2-mercaptonaphthalene.
Specific examples of the compound having an S- group include diallyl disulfide and dioctyl dithiodipropionate, and examples of the compound having a -COOH group include cinnamic acid, benzoic acid, chlorobenzoic acid, phthalic acid,
Examples of the compound having an —NO ₂ group include nitronaphthalene and nitroaniline, and examples of the compound having an OH group include aminocresol, aminonaphthol, m-cresol, oxyanthracene and oxy. Anthraquinone, oxanthrone,
3-oxy-9-anthrone, oxynaphthoquinone, dioxyanthracene, dioxyanthraquinone, 1,5
-Dioxynaphthalene, 1,8-dioxynaphthalene,
2,6-dioxynaphthalene, 3,5-dimethylphenol, naphthol and the like can be mentioned.

Further, as the compound (B) used in the present invention, --SH, --SS--, --COOH,-
Those having two or more kinds of structural units selected from the group consisting of NO ₂ and —OH are particularly preferable, and specific examples thereof include salicylic acid, thiosalicylic acid, dithiosalicylic acid, nitrobenzoic acid, dinitrobenzoic acid and nitrophenol. .

In the aqueous suspension polymerization according to the present invention, the amount of the compound (B) added depends on the kind of the compound (B) used and the composition of the polymerizable monomer (A). However, it is 2 with respect to the polymerizable monomer (A).
0 to 0.0001% by weight, more preferably 10 to 0.0
It is about 01% by weight, more preferably about 5 to 0.01% by weight. If the addition amount of the compound (B) is less than 0.0001% by weight, the inhibiting effect on emulsion polymerization is small and the generation of fine particles cannot be prevented. On the other hand, if the addition amount exceeds 20% by weight, the suspended particles (monomer) are Therefore, chain transfer is likely to occur, and the degree of polymerization of the resulting resin particles does not increase.

The method of adding such a compound (B) is not particularly limited, and the method of adding it to the polymerizable monomer (A), the method of adding it to the aqueous phase, and the method of dissolving it in a solvent such as methanol. Then, a method of dispersing in an aqueous phase can be used.

The method for producing resin particles according to the present invention is carried out in the presence of a compound (B) containing a polymerizable monomer (A) containing a (meth) acrylic monomer as a main component as described above. Aqueous suspension polymerization is performed. A suitable polymerization temperature is 10 to 90 ° C, preferably about 30 to 80 ° C. In this suspension polymerization, it is preferable to carry out the reaction after controlling the particle diameter of the suspension particles of the polymerizable monomer (A) or while controlling the particle diameter, but particularly the particle diameter was regulated. It is preferable to carry out the reaction later. The regulation of the particle size is carried out, for example, by using a suspension prepared by dispersing a predetermined component in an aqueous medium in T. K. Stir with a homomixer. Alternatively, it is carried out by passing it through a high-speed stirrer such as a line mixer (for example, Ebara Milder) once or several times.

In suspension polymerization, a dispersion stabilizer may be added to stabilize the suspended particles. As the dispersion stabilizer, polyvinyl alcohol, gelatin,
Water-soluble polymers such as tragacanth, starch, methyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, sodium polyacrylate, sodium polymethacrylate, anionic surfactants, cationic surfactants, zwitterionic surfactants, nonionic surfactants There are activators, etc.Also, alginate, zein, casein, barium sulfate, calcium sulfate, barium carbonate, magnesium carbonate, calcium phosphate, talc, clay, diatomaceous earth, bentonite, titanium hydroxide, thorium hydroxide, metal oxide powder, etc. Is used.

Examples of the anionic surfactant include fatty acid oils such as sodium oleate and potassium castor oil, alkyl sulfate salts such as sodium lauryl sulfate and ammonium lauryl sulfate, alkylbenzene sulfonates such as sodium dodecylbenzenesulfonate, and alkylnaphthalene. Examples thereof include sulfonate, alkane sulfonate, dialkyl sulfosuccinate, alkyl phosphate ester salt, naphthalene sulfonate formalin condensate, polyoxyethylene alkylphenyl ether sulfate ester salt, polyoxyethylene alkyl sulfate ester salt and the like. As the nonionic surfactant, polyoxyethylene alkyl ether, polyoxyethylene alkylphenyl ether,
Examples thereof include polyoxyethylene fatty acid ester, sorbitan fatty acid ester, polyoxysorbitan fatty acid ester, polyoxyethylene alkylamine, glycerin fatty acid ester, and oxyethylene-oxypropylene block polymer. Examples of the cationic surfactant include alkylamine salts such as laurylamine acetate and stearylamine acetate, and quaternary ammonium salts such as lauryltrimethylammonium chloride. Examples of the zwitterionic surfactant include lauryl dimethylamine oxide.

In these dispersion stabilizers, the resin particles obtained have a predetermined particle size, for example, 0.1 to 500 μm, preferably 0.5 to 100 μm, and more preferably 0.5.
The composition and the amount to be used should be appropriately adjusted so as to be 30 μm to 30 μm, and for example, 0.01 to 29% by weight, preferably 0.1% to the polymerizable monomer (A).
Used in an amount of 1-10% by weight.

As the polymerization initiator used for the polymerization, oil-soluble peroxide type or azo type initiators usually used in suspension polymerization can be used. To give an example, for example, benzoyl peroxide, lauroyl peroxide, octanoyl peroxide, benzoyl orthochloroperoxide, benzoyl orthomethoxyperoxide, methyl ethyl ketone peroxide,
Peroxide initiators such as diisopropyl peroxydicarbonate, cumene hydroperoxide, cyclohexanone peroxide, t-butyl hydroperoxide, diisopropylbenzene hydroperoxide, 2,2′-azobisisobutyronitrile, 2, 2 '
-Azobis (2,4-dimethylvaleronitrile), 2,
2'-azobis (2,3-dimethylbutyronitrile),
2,2'-azobis (2-memethylbutyronitrile),
2,2'-azobis (2,3,3-trimethylbutyronitrile), 2,2'-azobis (2-isopropylbutyronitrile), 1,1'-azobis (cyclohexane-)
1-carbonitrile), 2,2'-azobis (4-methoxy-2,4-dimethylvaleronitrile), 2- (carbamoylazo) isobutyronitrile, 4,4'-azobis (4-cyanovaleric acid), Examples include dimethyl-2,2'-azobisisobutyrate. The polymerization initiator is preferably used in an amount of 0.01 to 20% by weight, particularly 0.1 to 10% by weight, based on the polymerizable monomer (A).

Further, during suspension polymerization, colorants such as pigments and dyes, or other additives may be added or added to the polymerizable monomer (A) or the aqueous phase, if necessary. You can also

Examples of the pigment include lead white, red lead, yellow lead, carbon black, ultramarine blue, zinc oxide, cobalt oxide, titanium dioxide, iron oxide, silica, titanium yellow, titanium black, and other inorganic pigments, Navels yellow. , Naphthol yellow S, Hanser yellow 10G, Benzidine yellow G, Benzidine yellow GR, Quinoline yellow lake, Permanent yellow NCG, Tartrazine lake, and other yellow pigments, molybdenum orange, permanent orange RK, benzidine orange G, indanthrene brilliant orange. Orange pigments such as GK, permanent red 4R, resole red, pyrazolone, red 4
R, Watching Red Calcium Salt, Lake Red D, Brilliant Carmine 6B, Eomin Lake, Rhodamine Lake B, Azaline Lake, Brilliant Carmine B etc. Red Pigment, Fast Violet B, Methyl Violet Lake, Dioxane Violet etc. Purple Pigment, Alkaline Blue Lake, Victoria Blue Rake,
Phthalocyanine blue, metal-free phthalocyanine blue,
Phthalocyanine blue partial chloride, fast sky blue, blue pigments such as indance blue BC, green pigments such as pigment green B, malachite green lake, fanal yellow green G, etc., isoindolinone, quinacridone, perinone pigment, perylene Organic pigments such as pigments, insoluble azo pigments, soluble azo pigments and dye lakes are used.

Examples of the dye include nitroso dye, nitro dye, azo dye, stilbene azo dye, diphenylmethane dye, triphenylmethane dye, xanthene dye, acridine dye, quinoline dye, methine dye,
Polymethine dye, thiazole dye, indamine dye, indophenol dye, azine dye, oxazine dye, thiazine dye, sulfur dye and the like are used.

Other additives include plasticizers, polymerization stabilizers, optical brighteners, magnetic powders, ultraviolet absorbers, antistatic agents, flame retardants and the like.

The colorant and other additives may be surface-treated by various methods for the purpose of improving dispersibility in the polymerizable monomer. As the surface treatment method, a method of treating with a long-chain hydrocarbon such as stearic acid and oleic acid, a method of treating with a polymerizable monomer having a polar group such as acrylic acid and methacrylic acid, and a method such as trimethylolpropane How to treat with a dihydric alcohol,
A method of treating with amines such as triethanolamine,
A method of treating with various coupling agents, or an aziridine group, an oxazoline group, an N-hydroxyalkylamide group, an epoxy group, a thioepoxy group, an isocyanate group capable of reacting with a colorant or other additive and a functional group on the surface thereof, Examples include a method of reacting a polymer having a reactive group such as a vinyl group, a silicon-based hydrolyzable group, and an amino group at a temperature of 20 to 350 ° C. to graft the polymer on the surface of a colorant or other additive. be able to. In particular, for example, when carbon black is used as the colorant,
JP-A-63-270,767 and JP-A-63-26
The carbon black graft polymer described in No. 5,913 is suitable. Also, when a colorant other than carbon black is used, the surface-treated colorant obtained by the method described in JP-A-1-118,573 is suitable.

Further, in the suspension polymerization method of the present invention, the water-insoluble fine particles (C) are added to the suspension of spherical particles formed by polymerization, and the spherical particles are aggregated.

When the water-insoluble fine particles are used, the same stable agglomeration as in the case of using a known aggregating agent is obtained, and floc particles having a preferable size are obtained, and a stable filtration operation can be performed to suspend the resin particles. It can be separated more easily than in the medium. In addition, the obtained resin particles do not have the problem in performance as seen when using a known coagulant, and it is considered that the resin particles are caused by the functional group existing on the surface of the resin particles due to the compound (B). Problems can be improved.

The water-insoluble fine particles (C) used in the present invention maintain the agglomeration of the spherical particles in an optimum state, remarkably improve the subsequent crushability, and further improve the physical properties of the resin particles obtained by crushing. Is to express. Therefore, the particle size of the water-insoluble fine particles (C) must be smaller than that of the spherical particles obtained by suspension polymerization, and is preferably 1/2 or less of the particle size of the spherical particles.
Specifically, the particle size of the water-insoluble fine particles (C) is 0.00
The thickness is preferably 1 to 10 μm, more preferably 0.
005 to 5 μm. If the particle diameter of the water-insoluble fine particles (C) is smaller than 0.001 μm, the effect of addition of fine particles, that is, the aggregating property, or the disintegrating property when used as an antiblocking agent, may be adversely affected. is there. On the other hand, when the particle diameter of the water-insoluble fine particles (C) exceeds 10 μm, the effect of the addition of the water-insoluble fine particles (C) becomes small, and when used as an antiblocking agent, the physical properties of the film may deteriorate. The addition amount of the water-insoluble fine particles (C) can be set in a wide range depending on the type and particle diameter of the water-insoluble fine particles (C) used, but if the amount is too small, the effect of the addition of the water-insoluble fine particles (C) will be large. Since it is difficult to develop, and when it is used in an excessively large amount, adverse effects such as reduction in transparency of the film may be induced when used as an antiblocking agent. 0
The amount is preferably 1 to 100 parts by weight, more preferably 0.05 to 50 parts by weight, still more preferably 0.1 to 10 parts by weight.
Parts by weight.

As the water-insoluble fine particles (C) used as the aggregating agent, various organic fine particles and inorganic fine particles can be used.

Examples of the organic fine particles include crosslinked and non-crosslinked polymer fine particles, the above-mentioned organic pigments, fine particles of charge control agents, waxes and the like. As the crosslinked and non-crosslinked resin fine particles, for example, styrene resin fine particles, acrylic resin fine particles,
Methacrylic resin particles, polyethylene resin particles,
Polypropylene resin particles, silicone resin particles, polyester resin particles, polyurethane resin particles, polyamide resin particles, epoxy resin particles,
Examples thereof include polyvinyl butyral resin particles, rosin resin particles, terpene resin particles, phenol resin particles, melamine resin particles, and guanamine resin particles.

Examples of the charge control agent include nigrosine, monoazo dye, zinc, hexadecyl succinate,
Alkyl esters or alkylamides of naphthoic acid,
Examples thereof include fine particles of a substance called a charge control agent in the field of electrophotography, such as nitrohumic acid, N, N-tetramethyldiaminebenzophenone, N, N-tetramethylbenzidine, triazine, and metal salicylate complex.

Examples of the waxes include polymers having a cyclic method softening point of 80 to 180 ° C., high melting point paraffin wax having a melting point of 60 to 70 ° C., fatty acid esters, and partially saponified products thereof, higher fatty acids, fatty acid metals. And fine particles of higher alcohols and the like.

Examples of the inorganic fine particles include alumina, titanium dioxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, silica sand, clay, mica, wollastonite, diatomaceous earth, Various inorganic oxide pigments, chromium oxide, cerium oxide, red iron oxide, antimony trioxide, magnesium oxide,
Zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, fine silica powder, silicon carbide, silicon nitride,
Examples thereof include powder or particles of boron carbide, tungsten carbide, titanium carbide, carbon black and the like.

Further, among these water-insoluble fine particles, the hydrophobicity index (Mw: methanol wettability) is 5
The above-mentioned resin particles are more preferable because good moisture resistance can be obtained. Examples thereof include various hydrophobically treated inorganic oxides such as hydrophobic silica, hydrophobic titania and hydrophobic zirconia, and conductive carbon black such as Ketjen black, acetylene black and furnace black.

The term "hydrophobicity index" as used in the present invention means a numerical value obtained by the following procedure. Weigh 0.2g of sample into a 200ml beaker and add pure water 50
Add ml. Methanol is added below the liquid surface with magnetic stirring. The end point is the point where no sample is observed on the liquid surface. The hydrophobicity is calculated from the required amount of methanol by the following formula. Hydrophobicity index (%) = {x / (50 + x)} × 100 Note) x is the amount of methanol used (ml).

In carrying out the present invention, these water-insoluble fine particles (C) may be used alone or in combination of two or more kinds.

The aggregating treatment is carried out by adding the water-insoluble fine particles (C) as described above to a suspension of spherical particles, and stirring the mixture for a predetermined period of time while stirring the suspension to obtain a suspension spherical shape. In order to cause the particles to aggregate or precipitate, it is not necessary to perform a heat treatment after the addition of the fine particles. However, from the viewpoint of operation efficiency, it is possible to perform a heat treatment for heating the suspension to a temperature not lower than the T _{g of} the polymer forming the spherical particles, as long as it does not cause excessive fusion of the resin particles. Is.

In the present invention, when the spherical particles are aggregated, an organic solvent which is a non-solvent may be added to the resin of the spherical particles. The organic solvent which is a non-solvent for the spherical particles can induce aggregation during isolation, purification or fractionation of the polymer substance. Further, the combined use with the water-insoluble fine particles (C) as described above is preferable because it promotes the adhesion of the water-insoluble fine particles (C) on the surface of the spherical particles. Such non-solvents include hydrocarbons such as hexane, heptane, octane and petroleum ether, lower alcohols such as methanol and ethanol. The non-solvent for the spherical particles as used herein means a solvent that does not dissolve or disperse the resin of the spherical particles.

Further, in the aggregating treatment using the water-insoluble fine particles (C) as described above, the bulk density of the spherical particle agglomerates is 0.1 to 0.9 g / cm ³ , particularly 0.2 to 0.7.
It is more preferable that the aggregated state is in the range of g / cm ³ .
The shape and size of the spherical particle agglomerate are not limited, but in consideration of the next step of filtration, drying, crushing of particles, etc., 20 to 10,000 μm, more preferably 30 to 1, It is better to generate particles of 000 μm. If the size is less than 20 μm, a very large energy or a special device is required to extract the particles.
If it exceeds 0000 μm, more energy is required for crushing.

Solid-liquid separation of the resin particles and the suspension after the coagulation treatment is performed by suction filtration because the spherical particles in the suspension are aggregated into particles of an appropriate size as described above. It can be easily carried out by using various general solid-liquid separators such as pressure filtration and centrifugal filtration.

The spherical particle aggregates separated from the suspension are
Next, after passing through a drying step, the spherical particle agglomerates are conveyed to a crushing step of crushing the spherical particles into an average particle diameter of substantially spherical particles before aggregation. For crushing, a crusher conventionally used for industrially producing powders, particles and the like can be used without limitation. In the aggregate, since the spherical particles are only point-bonded or slightly face-bonded at the interface, the average of spherical particles before agglomeration can be easily obtained by a small energy with a grinder having a relatively simple mechanism. It can be crushed to a particle size.

The resin particles obtained by the method for producing resin particles of the present invention as described above are secondary to the interface between the suspended particles and the aqueous phase by the action of the compound (B) during suspension polymerization. Since the emulsion polymerization that occurs in 1) is suppressed, there is no generation of by-product fine particles due to the emulsion polymerization, and the average particle size is 0.1
.About.500 .mu.m, particularly 0.5 to 100 .mu.m, and more particularly 0.5 to 30 .mu.m, the particle size distribution becomes extremely narrow. Further, the resin particles obtained by the production method of the present invention have extremely high heat resistance, and typically, the decomposition rate of the organic component when kept in air at 270 ° C. for 40 minutes is 60% by weight or less, preferably Is 40% by weight or less, more preferably 30% by weight or less.

As for the decomposition rate of the organic component kept at a constant temperature described in the present specification, the temperature rise from room temperature to 200 ° C. is performed at a rate of about 40 ° C./min, and thereafter the temperature rise rate is gradually decreased. Therefore, the time required to reach 270 ° C. from room temperature was adjusted to 20 minutes, the time when 270 ° C. was reached was set as time 0, and the weight loss after 40 minutes was measured was measured. The sample amount was about 20 mg, and the measurement was performed under the condition that clean air was flowed at a rate of about 40 ml / min. Further, the organic component described here refers only to a polymer component derived from a polymerizable monomer, and the components such as an organic colorant which is optionally added to the resin particles are excluded and considered. .

Further, in the resin particles obtained by the production method of the present invention, the surface properties of the resin particles are stabilized by the action of the water-insoluble fine particles (C), and the contact angle with water is 60.
° or more, especially 80 ° or more and wetting rate to water is 3
0 seconds or more, especially 60 seconds or more, or a contact angle with liquid paraffin of 15 ° or less and a wetting rate with liquid paraffin of 70 seconds or less, for example, generation of voids when used as an antiblocking agent. , Problems such as reduced operability are suppressed.

Here, the contact angle and the wetting rate in the present invention mean the numerical values given by the following methods.

Contact angle Resin particles are press-molded at room temperature (25 ° C. ± 5 ° C.) to prepare a sample for measurement, which is measured with a contact angle meter. The value after 5 seconds from the contact of the sample with the liquid is the contact angle.

Wetting rate Wetting rate is the time from the contact of a droplet having a diameter of 1.5 mm to the absorption and disappearance of the sample by press molding resin particles at room temperature (25 ° C. ± 5 ° C.) to obtain a measurement sample. And

The resin particles or the suspension of resin particles obtained by the production method of the present invention has various excellent properties such as excellent heat resistance stability and extremely narrow particle size distribution as described above. It is preferably used in applications.

For example, the resin particles according to the present invention are suitable as an anti-blocking agent for film molded products, particularly as an anti-blocking agent for polyolefin films.

The polyolefin-based polymer composition according to the present invention is obtained by blending the above resin particles with polyolefin. This polyolefin-based polymer composition can be used as it is, or by blending the composition with polyolefin and molding it into a film to obtain a polyolefin-based polymer film.

When the above resin particles are arranged in polyolefin, the resin particles have a high heat resistance stability and a stable particle surface property as described above, so that the resin particles are formed at the time of melt kneading in film molding. There is no risk that the components that decompose will generate volatiles and generate voids, and there will be no deterioration in the optical and mechanical properties of the film.
Further, there is no risk of environmental pollution due to the odor of such volatile components, and there is no fear of deterioration of operability due to contamination of the die or nozzle.

Further, the resin particles according to the present invention have a refractive index of 1.45 to 1.55 in a mode in which a coloring agent or the like is not added.
It is in the range of 1.55, which is close to the refractive index of polyolefin. For this reason, when the resin particles according to the present invention as a blocking inhibitor are arranged in a polyolefin-based polymer, there is no fear of deterioration of transparency. Generally, when any additive is used to improve the heat resistance of the resin particles, the refractive index is likely to be out of the above range, but in the resin particles according to the present invention, such an additive is used. It has a preferable refractive index because it is not necessary. Incidentally, as the refractive index of the resin particles in the case of being blended with the polyolefin as an anti-blocking agent,
Furthermore, it is desirable that it is 1.47 to 1.53, and particularly 1.48 to 1.52.

In addition, the resin particles according to the present invention preferably have a crosslinked structure, and the hardness of the particles is
For example, it has a relatively low pencil hardness of 5H or less, preferably 4H or less, and exhibits good scratch resistance when incorporated into a polyolefin film.

The blending amount of the resin particles in the polyolefin-based polymer composition of the present invention is 0.001 to 40% by weight, preferably 0.005 to 3% by weight based on the polyolefin.
About 5% by weight is suitable. The amount of resin particles blended is 0.0
When the amount is less than 01% by weight, for example, blocking resistance and slipperiness when formed into a film is difficult to develop, and when the amount is more than 40% by weight, it is difficult to uniformly disperse and mix.

When used as such an anti-blocking agent, the average particle size of the resin particles of the present invention is
It is desirable that the thickness is 0.1 to 30 μm, preferably 0.3 to 25 μm, and more preferably 0.5 to 20 μm.
When the average particle diameter is smaller than 0.1 μm, the blocking resistance effect and the sliding property improving effect are not sufficiently exhibited, so that a large amount of addition is required and the mechanical strength of the film may be impaired. On the other hand, when the average particle diameter is larger than 30 μm, the particles are likely to fall off from the film, which may cause a decrease in mechanical strength.

As the polyolefin used in the polyolefin-based polymer composition of the present invention, ethylene,
Examples include α-olefin homopolymers such as propylene and butylene, random copolymers, block copolymers, and mixtures thereof. Of these, a polymer containing ethylene and / or propylene as a main component is preferably used. It is also possible to add various additives to the polyolefin-based polymer composition of the present invention within a range that does not adversely affect the effects of the resin particles. Examples of these additives include various stabilizers such as antioxidants and ultraviolet absorbers, flame retardants, antistatic agents, colorants and inorganic fillers. Further, conventionally used antiblocking agents such as silica, zeolite and polymethylsilsesquioxane may be used in combination.

To mix and disperse the resin particles according to the present invention in the polyolefin resin, for example, a conventionally known mixer such as a ribbon blender, a Banbury mixer, a super mixer or an extruder may be used. As a method of adjusting the content of the above, a method of producing a high-concentration masterbatch by the above method and diluting this masterbatch with a polyolefin resin to form a film is preferable because the resin particles are more uniformly dispersed.

The polyolefin-based polymer composition of the present invention is prepared by, for example, inflation processing, calender processing, T
A polyolefin-based polymer film can be formed by various conventionally known manufacturing methods such as die processing, and may be a single-layer film having a single composition or a laminated film obtained by laminating the same or different kinds of films. As a method for obtaining a laminated film, after forming each film, a method of laminating by dry lamination, a heat lamination method, a method of extruding and laminating a resin on a film formed in advance, and a method of simultaneously forming a laminated film by a multilayer coextrusion method Method etc. are mentioned.

The film obtained by these methods may be further stretched to obtain a stretched polyolefin film. Furthermore, if necessary, at least one surface of the polyolefin-based polymer film may be subjected to corona discharge treatment. The corona discharge treatment may improve the properties such as blocking resistance and slipperiness.

[0091]

EXAMPLES The present invention will now be described in more detail with reference to examples, but these examples do not limit the present invention in any way. Moreover, all "parts" described in the following examples represent parts by weight.

Example 1 In a flask equipped with a stirrer, an inert gas inlet tube, a reflux condenser and a thermometer, polyoxyethylene alkylsulfoammonium (Hitenol N-08, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 1 900 parts of deionized water in which 1 part was dissolved was charged. Methyl methacrylate 90 prepared in advance there
Parts, 10 parts of trimethylolpropane trimethacrylate,
A mixture containing 1 part of azoisobutyronitrile and 1 part of thiosalicylic acid was charged, and T. K. A homogenizer (manufactured by Tokushu Kika Kogyo Co., Ltd.) was stirred at 8000 rpm for 5 minutes to form a uniform suspension.

Next, blowing nitrogen gas at 75 ° C.
The suspension polymerization reaction was carried out by continuously heating the mixture to 5 ° C. and stirring at this temperature for 5 hours. As a result, a suspension of resin particles having an average particle diameter of 2.67 μm and a standard deviation of 1.2 μm was obtained. The emulsion polymer produced as a by-product in the suspension was 0.3%. A suspension of the resin particles kept at 75 ° C. had a hydrophobicity index of 50.5.
10 parts of a dispersion of hydrophobic Aerosil R972 (manufactured by Nippon Aerosil Co., Ltd.) in which 90 parts of which had been previously dispersed in 90 parts of methanol was added, and heating was further performed for 30 minutes so as to maintain 75 ° C. Inside, a floc-like material formed by agglomeration of particles. Then, when this suspension was filtered using a suction filter, the filterability was good and the water content was about 45% by weight. Further, it was dried at 80 ° C. for 8 hours using a vacuum dryer to obtain a block-shaped product. This block-like material was crushed using Palpelizer AP-4TH (Hosokawa Micron Co., Ltd.) to obtain resin particles (1).

Table 1 shows the results obtained by measuring the contact angle of the resin particles (1) with water and liquid paraffin, the wetting rate with water and liquid paraffin, and the decomposition rate of organic components. The contact angle with water and liquid paraffin, the wetting rate with water and liquid paraffin, and the decomposition rate of organic components were measured by the following methods.

Contact angle with water and liquid paraffin Resin particles were press-molded at room temperature (25 ° C. ± 5 ° C.) to prepare a sample for measurement, which was measured with a FACE contact angle meter CA-A type (Kyowa Interface Science Co., Ltd.). . The value after 5 seconds from the contact of the sample with the liquid was defined as the contact angle.

Wetting rate with water and liquid paraffin Resin particles are press-molded at room temperature (25 ° C. ± 5 ° C.) to prepare a sample for measurement, until a droplet with a diameter of 1.5 mm comes into contact and is absorbed by the sample and disappears. Was the wetting speed.

Decomposition rate of organic components Using a thermogravimetric measuring device DTG-40 (manufactured by Shimadzu Corporation),
The temperature is raised from room temperature to 200 ° C. at a rate of about 40 ° C./min. After that, the temperature rising rate is gradually reduced to adjust the time from room temperature to 270 ° C. to 20 minutes.
It was calculated by measuring the weight loss after holding for 40 minutes with the time point at which the temperature reached 0 as time 0. The amount of resin sample at this time was about 20 mg, and the measurement was performed under the condition that clean air was flowed at a rate of 40 ml / min.

Example 2 90 parts of deionized water in which 0.5 part of polyoxyethylene nonylphenyl ether (Nonipol 200, manufactured by Sanyo Chemical Industries, Ltd.) was dissolved in the same flask as used in Example 1.
I prepared 0 copies. 80 parts of methyl methacrylate and ethylene glycol dimethacrylate 2 prepared in advance
A mixture containing 0 parts, 1 part of azoisobutyronitrile and 1 part of 2,2′-dithiosalicylic acid was charged, and T.
K. 6 using a homogenizer (made by Tokushu Kika Kogyo Co., Ltd.)
The mixture was stirred at 000 rpm for 5 minutes to form a uniform suspension.

Next, blowing nitrogen gas at 75 ° C.
The suspension polymerization reaction was carried out by continuously heating the mixture to 5 ° C. and stirring at this temperature for 5 hours. As a result, a suspension of resin particles having an average particle diameter of 4.52 μm and a standard deviation of 1.8 μm was obtained. The emulsion polymer produced as a by-product in the suspension was 0.2%. To this suspension of resin particles was added 10 parts of a dispersion liquid in which 90 parts of hydrophobic Aerosil R809 (manufactured by Nippon Aerosil Co., Ltd.) having a hydrophobicity index of 64.5 was previously dispersed in 90 parts of methanol,
When the mixture was further stirred for 30 minutes, a floc-like substance formed by agglomeration of particles in the suspension was formed. Then, this suspension was filtered using a suction filter, and further dried at 80 ° C. for 8 hours using a vacuum dryer to obtain a block. This block-shaped product is palpelizer AP-4
The resin particles (2) were obtained by crushing with TH (Hosokawa Micron Corporation). The results of examining the properties of the resin particles (2) in the same manner as in Example 1 are shown in Table 1.

Example 3 In a flask similar to that used in Example 1, 0.5 parts of polyoxyethylene nonylphenyl ether (Nonipol 200, manufactured by Sanyo Kasei Co., Ltd.) was dissolved in deionized water 90.
I prepared 0 copies. 80 parts of methyl methacrylate, 20 parts of trimethylolpropane trimethacrylate, 1 part of azoisobutyronitrile and 3,4 which had been prepared in advance.
Charge a mixture containing 1 part of ′ -dinitrobenzoic acid,
T. K. A homogenizer (manufactured by Tokushu Kika Kogyo Co., Ltd.) was stirred at 4000 rpm for 3 minutes to form a uniform suspension.

Next, blowing nitrogen gas at 75 ° C.
The suspension polymerization reaction was carried out by continuously heating the mixture to 5 ° C. and stirring at this temperature for 5 hours. As a result, a suspension of resin particles having an average particle diameter of 12.2 μm and a standard deviation of 3.8 μm was obtained. The emulsion polymer produced as a by-product in the suspension was 0.9%. To this suspension of resin particles was added 10 parts of a dispersion liquid in which 90 parts of hydrophobic Aerosil R809 (manufactured by Nippon Aerosil Co., Ltd.) having a hydrophobicity index of 64.5 was previously dispersed in 90 parts of methanol,
When the mixture was further stirred for 30 minutes, a floc-like substance formed by agglomeration of particles in the suspension was formed. Then, this suspension was filtered using a suction filter, and further dried at 80 ° C. for 8 hours using a vacuum dryer to obtain a block. This block-shaped product is palpelizer AP-4
The resin particles (3) were obtained by crushing with TH (Hosokawa Micron Co., Ltd.). The results of examining the properties of the resin particles (3) in the same manner as in Example 1 are shown in Table 1.

Comparative Example 1 The same flask used in Example 1 was charged with 900 parts of deionized water in which 1 part of polyoxyethylene nonylphenyl ether (Nonipol 200, manufactured by Sanyo Kasei Co., Ltd.) was dissolved. A mixture prepared by mixing 90 parts of methyl methacrylate, 10 parts of trimethylolpropane trimethacrylate, 1 part of azoisobutyronitrile and 1 part of thiosalicylic acid, which had been prepared in advance, was charged therein, and T. K. 8000 rpm by a homogenizer (made by Tokushu Kika Kogyo Co., Ltd.)
And stirred for 5 minutes to form a uniform suspension.

Next, blowing nitrogen gas at 75 ° C.
The suspension polymerization reaction was carried out by heating the mixture to 5 ° C. and stirring at this temperature for 5 hours to obtain a suspension of resin particles having an average particle diameter of 2.72 μm and a standard deviation of 1.3 μm. The emulsion polymer produced as a by-product in the suspension was 0.3%. This suspension was spray dried with Parbis GB22 (manufactured by Yamato Scientific Co., Ltd.) at an inlet temperature of 150 ° C. and an outlet temperature of 80.
° C, dry air amount 0.5 m ³ / min, spray air pressure 1.0
Comparative resin particles (1) were obtained by drying under conditions of kg / cm ² . The properties of the obtained comparative resin particles (1) are shown in Example 1.
Table 1 shows the results of the same examination as above.

Comparative Example 2 90 parts of deionized water prepared by dissolving 0.5 parts of polyoxyethylene nonylphenyl ether (Nonipol 200, manufactured by Sanyo Kasei Co., Ltd.) in the same flask as used in Example 1.
I prepared 0 copies. 80 parts of methyl methacrylate and ethylene glycol dimethacrylate 2 prepared in advance
A mixture containing 0 parts, 1 part of azoisobutyronitrile and 1 part of 3,4-dinitrobenzoic acid was charged, and T.I. K.
400 using a homogenizer (made by Tokushu Kika Kogyo Co., Ltd.)
The mixture was stirred at 0 rpm for 3 minutes to form a uniform suspension.

Next, blowing nitrogen gas at 75 ° C.
As a result of carrying out suspension polymerization reaction by continuously heating the mixture to 5 ° C. and stirring at this temperature for 5 hours, a suspension of resin particles having an average particle diameter of 4.23 μm and a standard deviation of 1.6 μm was obtained. The emulsion polymer produced as a by-product in the suspension was 0.9%. To this suspension of resin particles kept at 75 ° C, 30 parts of a flocculant consisting of 4 parts of liquid sulfuric acid band and 96 parts of deionized water was added, and further heated for 30 minutes so as to maintain 75 ° C. However, a floc-like material formed by agglomeration of particles in the suspension was formed. Then, this suspension was filtered using a suction filter, and further dried at 80 ° C. for 8 hours using a vacuum dryer to obtain a block. This block-like material was crushed using Palpelizer AP-4TH (Hosokawa Micron Co., Ltd.) to obtain comparative resin particles (2). The results of examining the properties of the resin particles (2) in the same manner as in Example 1 are shown in Table 1.

Comparative Example 3 The same flask as used in Example 1 was charged with 900 parts of deionized water in which 0.5 part of polyvinyl alcohol (PVA-205, manufactured by Kuraray Co., Ltd.) was dissolved. A previously prepared mixture containing 80 parts of methyl methacrylate, 20 parts of trimethylolpropane trimethacrylate, 1 part of azoisobutyronitrile and 1 part of 3,4-dinitrobenzoic acid was charged therein, and T. K. A homogenizer (manufactured by Tokushu Kika Kogyo Co., Ltd.) was stirred at 4000 rpm for 3 minutes to form a uniform suspension.

Next, blowing nitrogen gas at 75 ° C.
As a result of carrying out suspension polymerization reaction by continuously heating and stirring for 5 hours at this temperature, a suspension of resin particles having an average particle diameter of 13.5 μm and a standard deviation of 3.8 μm was obtained. The emulsion polymer produced as a by-product in the suspension was 27%. To this suspension of resin particles kept at 75 ° C. was added 30 parts of a flocculant consisting of 4 parts of liquid sulfuric acid band and 96 parts of deionized water,
When heating was further performed for 30 minutes so as to maintain the temperature at 75 ° C., a floc-like material formed by agglomeration of particles in the suspension was formed. Then, this suspension was filtered using a suction filter, and further dried at 80 ° C. for 8 hours using a vacuum dryer to obtain a block. This block-like material was crushed using Palpelizer AP-4TH (Hosokawa Micron Co., Ltd.) to obtain comparative resin particles (3). The results of examining the properties of the resin particles (3) in the same manner as in Example 1 are shown in Table 1.

Example 4 Polypropylene (melt flow index (MI) 2
g / 10 minutes, heptane-soluble content 3%) 99 parts, and 1 part of the resin particles (1) obtained in Example 1 was blended and kneaded at 230 ° C. in a Banbury mixer to form a pelletized polyolefin polymer. A composition (1) was obtained. A film was prepared from the obtained polyolefin-based polymer composition (1) under the following conditions, and the growth rate of the heat-deteriorated product by-produced during the film preparation, the turbidity of the film, the dynamic friction coefficient, the blocking strength and the tensile elastic modulus were obtained. Was measured.

-Conditions for film production: The content of resin particles was diluted with the above polypropylene so as to be 0.1%, extruded into a sheet at 260 ° C in an extruder, and stretched in the longitudinal direction at 140 ° C and in the transverse direction. Stretching temperature 175
The stretched polypropylene film was stretched at a temperature of 5 ° C. at a ratio of 5 times length and 9 times width.

Turbidity According to JIS K 6714, turbidity was measured using a colorimetric color difference meter NDH-1001DP (turbidity meter) manufactured by Nippon Denshoku Industries Co., Ltd.

-Dynamic friction coefficient Two specimens having a width of 50 mm and a load of 200 g
One side of the film was slid at a friction speed of 35 mm / min, the resistance value (g) was measured, and the coefficient was calculated from the following formula. The resistance value was measured with a slip tester manufactured by Toyo Seiki. Dynamic friction coefficient = (Chart scale (g)) / (200g) · blocking strength (g / cm ²⁾ 40 ℃ under a load of 73 g / cm ² overlay film sample dimensions 120 mm × 120 mm, in an atmosphere of RH 90% The sample has a blocking area of 1 after standing for 24 hours.
It was cut out so as to have a size of ² cm ^2, and the shear peel strength (g) was measured by an autograph and determined from the following formula. Blocking strength = (shear peel strength (g)) / (12c
m ² ) -Tensile elastic modulus (kg / mm ² ) It was measured according to ASTM D-882.

Example 5 and Comparative Examples 4 and 5 Instead of the resin particles (1), the resin particles (2) obtained in Example 2 and the comparative resin particles (1) obtained in Comparative Example (1) were used.
The same procedure as in Example 3 was repeated using the comparative resin particles (2) obtained in Comparative Example (2) to obtain a polyolefin polymer composition (2) and a comparative polyolefin polymer composition (1), respectively. ) And a comparative polyolefin polymer composition (2) were obtained. The properties of each polyolefin-based polymer composition were measured in the same manner as in Example 3. Table 2 shows the results.

Example 6 and Comparative Example 6 Low density polyethylene (melt flow index (M
I) 2.0 g / 10 minutes, density 0.92 g / cm ³ ) 75
25 parts by weight of the resin particles (3) obtained in Example 3 and the comparative resin particles (3) obtained in Comparative Example 3 were blended into a part and kneaded at 220 ° C. in a Banbury mixer to form pellets. And a polyolefin-based polymer composition (3), respectively
A comparative polyolefin polymer composition (3) was obtained. Films of the obtained polyolefin-based polymer composition (3) and comparative polyolefin-based polymer composition (3) were produced under the conditions shown below, and a heat-degraded product produced as a by-product during the production of the film was produced as in Example 4. The growth rate, turbidity of the film, coefficient of dynamic friction, blocking strength and tensile modulus were measured.

-Conditions for film production: The resin particles were diluted with the above-mentioned low density polyethylene so that the content thereof was 0.5%, and extruded in a sheet form at 200 ° C with an extruder from a T-die to obtain a polyethylene film. .

[0115]

[Table 1]

[0116]

[Table 2]

[0117]

As described above, according to the present invention, the polymerizable monomer (A) containing a (meth) acrylic monomer as a main component is mixed with -SH, -SS-, -COOH, -CO. NO ₂
And the presence of a compound (B) having at least one structural unit selected from the group consisting of -OH, which is substantially insoluble in water and hardly soluble in the polymerizable monomer (A). Aqueous suspension polymerization is performed below to obtain 1-100 μm
The water-insoluble fine particles (C) are added to a suspension of spherical particles having an average particle diameter of 1, and the spherical particles are aggregated and separated from the suspension medium. It is possible to suppress emulsion polymerization as a by-product due to the polymerizable monomer (A) partially dissolved in the phase, and to improve polymerization stability, yield, and physical properties of the obtained particles, particularly heat stability, uniform particle size. Properties can be improved, and after the suspension polymerization is completed, the water-insoluble fine particles (C) are added to the suspension of the spherical particles so that the spherical particles are aggregated and separated from the suspension medium. Therefore, not only the separation operation becomes simple, but also the surface properties of the obtained resin particles can be modified.

When the resin particles of the present invention thus obtained are blended in a resin matrix such as a polyolefin polymer for film formation or molding, generation of voids, dies or nozzles. Occurrence of defects such as deterioration of operability due to the pollution of is suppressed, which is industrially advantageous.

Continuation of front page (72) Inventor Mori Etsukuni 4-1-1 Koraibashi, Chuo-ku, Osaka-shi, Osaka Nippon Shokubai Osaka head office

Claims (13)

[Claims] 1. A polymerizable monomer (A) containing a (meth) acrylic monomer as a main component is added to -SH, -SS-, -C.
A compound having at least one structural unit selected from the group consisting of OOH, —NO ₂ and —OH, which is substantially insoluble in water and hardly soluble in the polymerizable monomer (A). Aqueous suspension polymerization is carried out in the presence of (B), water-insoluble fine particles (C) are added to the obtained suspension of spherical particles having an average particle diameter of 1 to 100 μm, and the spherical particles are aggregated with each other. A method for producing resin particles, characterized in that the resin particles are separated from the suspension medium. 2. The compound (B) is --SH, --SS--,
The method for producing resin particles according to claim 1, which has two or more kinds of structural units selected from the group consisting of —COOH, —NO ₂ and —OH. 3. The method for producing resin particles according to claim 1, wherein the amount of the compound (B) added is 20 to 0.0001% by weight based on the polymerizable monomer (A). 4. The method for producing resin particles according to claim 1, wherein the water-insoluble fine particles (C) have a hydrophobicity index of 5 or more. 5. The spherical resin particles according to claim 1, wherein an organic solvent which is a non-solvent is added to the resin of the resin particles when the resin particles are aggregated. Manufacturing method. 6. Resin particles obtained by the manufacturing method according to claim 1. 7. The contact angle to water is 60 ° or more,
The resin particles according to claim 6, which have a wetting rate with water of 30 seconds or more. 8. The contact angle with liquid paraffin is 15 °.
And the wetting rate for liquid paraffin is 7 or less.
The resin particles according to claim 6 or 7, which are 0 seconds or less. 9. The resin particles according to any one of claims 6 to 8, wherein the decomposition rate of the organic component when kept at 270 ° C. in air for 40 minutes is 60% by weight or less. 10. The resin particle according to claim 6, which has an average particle diameter of 0.1 to 500 μm. 11. The resin particle according to claim 6, which has a refractive index of 1.45 to 1.55. 12. A polyolefin-based polymer composition obtained by blending the resin particles according to any one of claims 6 to 11 with a polyolefin. 13. The polyolefin-based polymer composition according to claim 12, wherein 0.001 to 40% by weight of resin particles is blended with the polyolefin.