JP2000191708A - Polymer particle, its production, coating agent composition, polymer composition, sheetlike/filmy formed material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain polymer particles having a sharp particle diameter distribution, to provide a method for producing the polymer particles and to obtain a coating agent composition and a formed product using the polymer particles. SOLUTION: The polymer particles have 1.42-1.59 refractive index, >=50 wt.% insolubility in toluene 0.3-30 μm weight-average particle diameter Dw and the ratio of Dw/Dn of the weight-average particle diameter to number- average particle diameter Dn of <=1.3 and <3 wt.% ratio of coarse polymer particles having >=10×Dw μm particle diameter. The polymer particles are obtained by absorbing an oil-soluble polymerization initiator in seed polymer particles having 0.05-10 μm weight-average particle diameter Dw and the ratio of Dw/Dn of <=1.2 in an aqueous medium, absorbing a prescribed monomer and polymerizing. The polymer particles are added to a binder or a thermoplastic resin and used to produce a sheetlike/filmy formed product having excellent transparency, blocking resistance, slipperiness, or the like, and film improving effect.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polymer particle and a method for producing the same, a coating composition, a polymer composition, and a molded product. Polymer particles having high solubility in water and a narrow particle size distribution, a method for easily and stably producing the polymer particles, a coating composition containing the polymer particles, and having excellent blocking resistance and optical properties, The present invention relates to a united composition and a molded product obtained by molding the composition.

[0002]

2. Description of the Related Art Resin films, laminated papers and photographic papers have a problem that a so-called blocking phenomenon is liable to occur when the films are laminated to each other, that is, in order to prevent the blocking phenomenon. Various particles have been used. As a characteristic of such particles,
A larger particle size is desirable because it can sufficiently exhibit blocking resistance, and a more uniform particle size distribution,
It is desirable because the amount of polymer particles added to sufficiently exhibit blocking resistance can be reduced, thereby maintaining the transparency of the film. Such particles include, for example, inorganic particles such as fine powder silica and fine powder talc, but the inorganic particles are poorly dispersed when mixed with the resin, and as a result, the aggregates increase the transparency of the resin film. There is a problem that the reduced or dropped fine particles damage the resin film and deteriorate the quality of the resin film. In addition, when a polyolefin film to which inorganic particles are added and mixed is stretched, voids are generated around the inorganic particles, so that the transparency of the film is reduced, and as a result, the commercial value as a packaging material is significantly impaired. There are also problems. Therefore, organic polymer particles are used as particles for preventing the blocking phenomenon in order to improve the above-mentioned disadvantages of the inorganic particles.

[0003] As a method for producing organic polymer particles, a method based on suspension polymerization or emulsion polymerization has been known in addition to a method based on mechanical pulverization. However, the mechanical pulverization and suspension polymerization methods can obtain relatively large polymer particles having a particle diameter of 1 to 100 μm, while mechanical pulverization mechanically divides the polymer, and suspension polymerization involves mechanically dividing the monomer. Has the property of broadening the particle size distribution. Therefore, in order to obtain a polymer particle having a uniform particle diameter, a multi-stage classification process is required, so that the number of steps is increased and the production is not easy, and the yield is low.

Further, polymer particles obtained by mechanical pulverization or suspension polymerization are used for the purpose of improving the above-mentioned disadvantages of the inorganic particles, however, because the adhesion between the particles and the resin film is not sufficient. In some cases, voids were generated during stretching of the film to reduce transparency, or when the particle size distribution was wide and the elasticity of the film was low, the anti-blocking effect was sometimes insufficient. On the other hand, JP-A-6-73106 proposes a technique in which polymer particles having a crosslinked structure obtained by a suspension polymerization method (hereinafter, simply referred to as “crosslinked polymer particles”) are used in place of inorganic fine particles. According to such a technique, an improvement effect to some extent is recognized as compared with the case where inorganic fine particles are added and mixed, but it is still not sufficient.

[0005] In the particles obtained by emulsion polymerization, monodispersed polymer particles having a sharp particle size distribution can be obtained relatively easily, but it is difficult to obtain polymer particles having a particle size exceeding 1 µm, and thus they are suitable for the above applications. It was difficult to obtain polymer particles which were poor. In order to improve such disadvantages, a seed polymerization method for producing polymer particles by successively absorbing and polymerizing monomers in the seed particles has been developed. As an example of the seed polymerization method, for example,
Japanese Patent No. 24369 discloses a method in which a swelling aid is used in combination with seed particles to increase the monomer absorption capacity, and to obtain particles having a particle size of several μm by seed polymerization. However, in such a seed polymerization method, there is a problem that the dispersed particles aggregate and fuse with each other during the polymerization, and coarse particles larger than the target particles are generated. In addition, in this method, fine particles much smaller than the target particles are also generated at the same time, and purification is required to separate these non-target particles, resulting in a decrease in yield and a decrease in polymerization stability. There is a problem.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has a specific refractive index, a high degree of insolubility in an organic solvent, a narrow particle size distribution, and a polymer having the same. It is an object of the present invention to provide a method for easily and stably producing particles. In addition, the present invention is to improve the dispersibility, the occurrence of voids when applying conventional inorganic particles or polymer particles obtained by suspension polymerization to a resin film, by suppressing the occurrence of voids, transparency, blocking resistance and slipperiness It is an object of the present invention to provide a coating composition and a polymer composition having excellent film-modifying effects, and a molded product obtained by molding these compositions.

[0007]

The polymer particles of the first invention have a refractive index of 1.42 to 1.59, an insolubility in toluene of 50% by weight or more, and a weight average particle diameter Dw of 0.1%. 3 to 30 μm, and a ratio Dw / to the number average particle diameter Dn.
Dn is 1.3 or less, and the ratio of coarse polymer particles having a particle size of 10 × Dw μm or more is less than 3% by weight. The refractive index of the polymer particles of the first invention is 1.
42 to 1.59, preferably 1.45 to 1.55. When the refractive index is less than 1.42 or more than 1.59, when added to the resin composition, the difference in refractive index from the resin composition increases, causing light scattering and causing the transparency of the resin composition to increase. Is undesirably reduced. The refractive index can be measured by a known method, for example, a method using a standard solution, an Abbe refractometer, or the like. The insolubility of the polymer particles of the first invention in toluene is 50% by weight or more, preferably 80% by weight or more. If the insolubility in toluene is less than 50% by weight, the heat resistance is inferior. Therefore, when mixed with the resin composition, it is partially dissolved in the resin composition, kneaded into the resin composition, or a large load is applied. In such a case, the polymer particles are deformed, and as a result, the blocking resistance is lowered, which is not preferable. The above-mentioned insolubility of toluene is measured by the method described in Examples.

Further, the weight average particle diameter Dw of the polymer particles of the first invention is 0.3 to 30 μm (preferably 0.4 to 30 μm).
20 μm, more preferably 1 to 10 μm), and the ratio Dw / Dn to the number average particle diameter Dn is 1.3 or less (preferably 1.2 or less, more preferably 1.1 or less). Is less than 3% by weight (preferably less than 2% by weight, more preferably less than 1%) of 10 × Dw μm or more. The weight average particle diameter Dw is 0.
If it is less than 3 μm, the effect of blocking resistance cannot be expected,
If it exceeds 30 μm, the transparency of the resin composition is undesirably reduced. When Dw / Dn exceeds 1.3,
It is not preferable because the uniformity of the particle size distribution is impaired and the effect of adding the polymer particles is deteriorated. Further, when the proportion of the coarse particles is 3% by weight or more, the film appearance is remarkably deteriorated when applied to a film. It is not preferable. The weight average particle diameter Dw can be determined by a known method such as a method using a light scattering method. The number average particle diameter Dn can be determined by measuring from a photograph taken with a transmission electron microscope. The coarse polymer particles can be determined by a known method such as a particle counter.

The polymer particles of the first invention may be of a crosslinked or non-crosslinked type, but are preferably made of a crosslinked polymer. That is, a polymer obtained by homopolymerization or copolymerization of only a non-crosslinkable monomer may be used. However, as in the second invention, a polymer obtained by polymerizing a non-crosslinkable monomer and a crosslinkable monomer is used. Is preferred. Such crosslinked polymer particles are preferable because they have excellent heat resistance.

[0010] The method for producing polymer particles of the fourth invention is as follows.
The weight average particle diameter Dw is 0.05 to 10 μm, and the ratio Dw to the number average particle diameter Dn is 100 parts by weight of the monomer component.
After at least a part of 0.1 to 10 parts by weight of an oil-soluble polymerization initiator is absorbed in 0.1 to 5 parts by weight of a seed polymer particle having a / Dn of 1.2 or less in an aqueous medium, a non-crosslinkable monomer is added. Polymer particles are produced by absorbing and polymerizing at least a part of a monomer component containing 10 to 95 parts by weight of a monomer and 5 to 90 parts by weight of a crosslinkable monomer.

The non-crosslinked type monomer or the crosslinked type monomer constituting the first invention and used in the fourth invention can use the following. The above “non-crosslinkable monomer”
As the (meth) acrylate monomer,
Aromatic monovinyl compound, vinyl cyanide compound,
Vinyl ester compounds, acrylamide compounds,
Examples include an ethylenically unsaturated carboxylic acid and an aliphatic conjugated diene monomer. Examples of the (meth) acrylate-based monomers include methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, and dodecyl (meth) acrylate. , Stearyl (meth) acrylate, (meth)
2-ethylhexyl acrylate, tetrahydrofurfuryl (meth) acrylate, n-octyl (meth) acrylate, dodecyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, glycidyl acrylate, (meth) ) N, N'-dimethylaminoethyl acrylate, methoxydiethylene glycol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, 2-hydroxyethyl (meth) acrylate, and the like. Examples of the aromatic monovinyl compound include styrene, ethylvinylbenzene, α-methylstyrene, fluorostyrene, vinylpyrine and the like. Examples of the vinyl cyanide compound include acrylonitrile and methacrylonitrile. Examples of the vinyl ester compound include vinyl acetate. Examples of the acrylamide-based monomer include acrylamide, methacrylamide, N, N-dialkylamide, and N, N-dimethylaminopropyl (meth) acrylamide. Examples of the ethylenically unsaturated carboxylic acid include itaconic acid, acrylic acid, methacrylic acid, fumaric acid, and maleic acid. Examples of the aliphatic conjugated diene-based monomer include butadiene, isoprene, 4-methyl-1-pentene, 2-chloro-1,3-
Butadiene, chloroprene and the like. The above monomers can be used alone or in combination of two or more. Among the above monomers, preferred monomers are those containing a (meth) acrylate compound as an essential component. In this case, the refractive index can be easily adjusted within the range of 1.45 to 1.55. The type and amount of the monomer are appropriately determined so that the desired refractive index of the polymer particles can be obtained.

The "crosslinkable monomer" includes two or more non-conjugated divinyl compounds typified by divinylbenzene, polyvalent acrylate compounds typified by trimethylolpropane trimethacrylate, and trimethylolpropane triacrylate. Preferably, a compound having two or three copolymerizable double bonds can be used.
These compounds can be used alone or in combination of two or more.

Examples of the polyvalent acrylate compound which can be used as the "crosslinkable monomer" include the following compounds. Diacrylate compound polyethylene glycol diacrylate, 1,3-butylene glycol diacrylate, 1,6-butylene glycol diacrylate, 1,6-hexane glycol diacrylate, neopentyl glycol diacrylate, polypropylene glycol diacrylate, 2,
2'-bis (4-acryloxypropyloxyphenyl)
Propane, 2,2'-bis (4-acryloxydiethoxyphenyl) propane, methylenebisacrylamide triacrylate compound trimethylolpropane triacrylate, trimethylolethane triacrylate, tetramethylolmethane triacrylate tetraacrylate compound tetramethylolmethane tetraacrylate , Pentaerythritol tetraacrylate, ditrimethylolpropane tetraacrylate dimethacrylate compound ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate,
1,4-butylene glycol dimethacrylate, 1,6
-Hexane glycol dimethacrylate, neopentyl glycol dimethacrylate, dipropylene glycol dimethacrylate, polypropylene glycol dimethacrylate, 2,2′-bis (4-methacryloxydiethoxyphenyl) propane trimethacrylate compound trimethylolpropane trimethacrylate, trimethylol Ethane trimethacrylate

Among the above compounds, it is preferable to use divinylbenzene, ethylene glycol dimethacrylate and trimethylolpropane trimethacrylate, and particularly preferable to use trimethylolpropane trimethacrylate.

In the production method according to the fourth aspect of the present invention, the “seed polymer particles” include oil-soluble polymerization from the viewpoint of promoting the polymerization reaction more efficiently by absorbing the monomers in the subsequent step. It preferably has the property of absorbing the initiator. Examples of such a polymer include a styrene polymer, a styrene copolymer such as a styrene-butadiene copolymer, and a (meth) acrylate-based polymer. In addition, it is also possible to use an aqueous dispersion of polymer particles in which the surface of polymer particles, crosslinked polymer particles, or inorganic particles having a composition having a low swelling property is coated with the polymer.
Further, the polymer particles obtained in the fourth invention can be used as seed polymer particles in the next step.
The seed polymer particles can be used in the form of a dispersion such as an aqueous latex, emulsion or suspension.

The particle size distribution of the seed polymer particles is as follows:
In order to make the particle size distribution of the finally obtained polymer particles monodisperse, the polymer particles should be monodisperse particle diameters, specifically, the ratio (Dw / D) of the weight average particle diameter Dw to the number average particle diameter Dn.
n) is preferably 1.2 or less (preferably 1.1 or less). The particle diameter of the seed polymer particles can be arbitrarily selected, but is preferably 10 to 70% (preferably 15 to 50%) of the particle diameter of the finally obtained polymer particles, and the weight average. The particle diameter Dw is 0.05 to 10 μm (preferably 0.1 to 5 μm). If it is less than 10%, the polymerizable monomer is less likely to be absorbed by the seed polymer particles, resulting in increased generation of new particles, which is not preferable. On the other hand, when it exceeds 70%, the ratio of the seed polymer particles is excessively increased, and as a result, the productivity of the polymer particles is unpreferably decreased.

[0017] The "oil-soluble polymerization initiator", solubility in water 8 ^- better to use a ^2% by weight, in a later step, more easily absorbed monomer, more efficient polymerization reaction It is preferable because it can be advanced. Examples of such an oil-soluble polymerization initiator include, for example, lauroyl peroxide, benzoyl peroxide, octanoyl peroxide, 3,5,5-trimethylhexanoyl peroxide, t-butylperoxy 2-ethylhexanoate, Organic peroxides such as -t-butylperoxy 2-ethylhexanoate and di-t-butyl peroxide;
Examples include azo compounds such as azobisisobutyronitrile and azobiscyclohexanecarbonitrile.
The oil-soluble polymerization initiator is soluble in water in liquid form 10 ^{- 2}
If less wt%, although it can be used, or a solid, or a water solubility of 10 ^- in the case of those of more than ² wt%, as a solvent, a water solubility of 10 ^{- 2} wt% It is preferable to use it by dissolving it in the following organic compounds. Such solubility in water is 10 ^- The ^2% or less by weight of the organic compound, the organic compound is preferably a molecular weight of 5000 or less liquid, such as hexane, heptane, octane, 1-chloro-dodecane, dioctyl adipate, methacrylic And stearyl acid.

In the present invention, at least a part of the oil-soluble initiator is used in an amount of 0.1 to 5 parts by weight (preferably 0.1 to 5 parts by weight) based on 100 parts by weight of the monomer component. 0.5 to 3 parts by weight).
The term “absorption” includes not only the case where the oil-soluble initiator completely penetrates into the seed polymer particles, but also the case where at least a part of the oil-soluble initiator is absorbed and the rest is attached to the surface of the seed polymer particles. . “At least a portion” specifically means 90% or more, preferably 95% of the oil-soluble initiator.
Above, more preferably 97% or more permeates into the seed polymer particles.

As a method for absorbing the oil-soluble initiator into the seed polymer particles, the above-mentioned oil-soluble initiator is mixed with an emulsifier having a critical micelle concentration of not more than the critical micelle concentration, and an aqueous medium is mixed with an ultrasonic fine dispersion homogenizer or an orifice. It is preferable to form droplets of submicron size or less with a passage-type high-pressure homogenizer or the like, and then mix the droplets with an aqueous dispersion of seed polymer particles. As the emulsifier used in the above method, known emulsifiers can be used, for example, anionic emulsifiers such as sodium dodecylbenzenesulfonate, sodium lauryl sulfate, sodium dialkylsulfosuccinate, and formalin condensate of naphthalenesulfonic acid; Examples include nonionic emulsifiers such as oxyethylene nonylphenol ether, polyethylene glycol monostearate, and sorbitan monostearate, and reactive emulsifiers. In addition to water, a water-soluble organic solvent can be used in combination with the aqueous medium. Examples of such an organic solvent include acetone, methanol, ethanol, propanol, tetrahydrofuran, and dimethylformaldehyde. In addition, in this homogenizer treatment step, it is usually preferable to perform cooling in order to avoid heat generation.

After the oil-soluble initiator is absorbed by the seed polymer particles, the monomers are absorbed and polymerization is carried out to produce the polymer particles of the first invention. Incidentally, this "absorption" is also the same as described above, not only when the monomer completely penetrates into the oil-soluble initiator and the seed polymer particles,
This includes the case where at least a part is absorbed and the rest is attached to the surface of the seed polymer particles. "At least some"
Specifically, it refers to a case where 90% or more, preferably 95% or more, and more preferably 97% or more of the monomer components penetrate into the seed polymer particles. As the monomer used in the fourth invention, a non-crosslinkable monomer is 10 to
95 parts by weight and a crosslinkable monomer are used in a proportion of 5 to 90 parts by weight. In addition, the same ratio is also preferable for the monomer constituting the polymer particles of the first invention. When the amount of the crosslinkable monomer is less than 5 parts by weight, the heat resistance of the produced polymer particles is reduced due to the low degree of crosslinking, and as a result, the resin particles are kneaded and molded, or a large load is applied. In such a case, the polymer particles are deformed and the blocking resistance is lowered, which is not preferable.

In the present invention, preferably, a hydroxyl group, a carboxyl group, an amino group, or the like is used for stabilizing the dispersion of particles formed by absorbing the non-crosslinkable monomer and the crosslinkable monomer into the seed polymer particles. Polymers containing at least one epoxy group can be used as suspension stabilizers. As the suspension stabilizer, for example, polyvinyl alcohol, carboxymethyl cellulose, polyacrylate,
Rosin resin, polyvinylpyrrolidone, poly (meth) acrylate polymer and the like are mentioned. this house,
Water-soluble ones (polyvinyl alcohol, carboxymethyl cellulose, polyacrylate, etc.) are preferred. This suspension stabilizer is usually used in an amount of 0.1 to 10 parts by weight based on 100 parts by weight of the polymerizable monomer. If the amount is less than 0.1 part by weight, the polymerization stability deteriorates, and if it is more than 10 parts by weight, there is a problem such as coloring when used as an additive. Further, an anionic surfactant, a nonionic surfactant or the like can be used as appropriate as a dispersion stabilizer.

In the production method of the fourth invention, the polymerization is preferably carried out at a temperature not higher than the decomposition temperature of the oil-soluble polymerization initiator, and is usually 40 to 90 ° C., preferably 50 to 80 ° C.
Performed at ° C.

[0023] The coating composition for coating a sheet or film according to the fifth invention comprises the polymer particles according to any of the first to third inventions and a binder having a film-forming property. Features. Examples of the “binder” include (meth) acrylate polymer, urethane polymer, PVA (polyvinyl alcohol), CMC
(Carbomethoxycellulose or a salt thereof) and the like. Among them, (meth) acrylate polymers or PVA are preferable. Thereby, the performance of the present invention can be further brought out. The coating composition can be used by applying it to a sheet or film such as a resin film, laminated paper, photographic paper and the like.
In this case, the "polymer particles" can be added in an amount of 0.01 to 50% by weight (preferably 0.1 to 10% by weight) based on the binder. When the amount added is 0.01
If it is less than 50% by weight, the anti-blocking property is hardly developed,
If the amount is more than the weight%, the adhesion of the polymer particles to the sheet-like material is reduced, so that the polymer particles are likely to fall off, which is not preferable. In addition, here, the thickness of the above-mentioned "sheet-like material" or "film-like material" is applied to a commonly used thickness, and generally, the former means a thicker one, and the latter means a thinner one. It includes everything from thin to thick, with a thickness of approximately 5 μm to 5 m
It means about m. The shape and size of the sheet or film to be applied are not particularly limited. The above significance is similarly applied to the following sixth to eighth inventions.

The polymer composition for a sheet or film according to the sixth invention is characterized by containing the polymer particles of any of the first to third inventions and a thermoplastic resin. . Examples of the “thermoplastic resin” include a polyolefin resin, a hydrogenated block copolymer, and a polyvinyl chloride resin. Among them, as in the seventh invention, polyolefin resins represented by polypropylene and polyethylene can be particularly preferably used for the above-mentioned "polymer particles". As this polyolefin resin,
For example, homopolymers of α-olefins such as ethylene, propylene, 1-butene, 1-pentene, 1-hexene, and 4-methyl-1-pentene, and a copolymer of two or more of these α-olefins were copolymerized. Copolymers of α-olefins, copolymers of α-olefins and copolymerizable monomers copolymerizable therewith (for example, vinyl acetate, maleic acid, etc.), or those composed of mixtures thereof, etc. Can be mentioned. Then, a composition in which a modifying elastomer such as a (hydrogenated) block copolymer is blended with the polyolefin-based resin is exemplified.

In the sixth and seventh aspects of the present invention, the above-mentioned “polymer particles” are usually added to the thermoplastic resin in an amount of 0.1 to 0.1%.
01 to 50% by weight, preferably 0.05 to 30% by weight,
More preferably, they can be used in a mixture of 0.1 to 20% by weight. When the content of the polymer particles is less than 0.01% by weight, the obtained polymer composition does not have sufficient blocking resistance. On the other hand, when the content exceeds 50% by weight, the obtained polymer composition Is unfavorable because the mechanical properties of

In order to produce the polymer compositions according to the sixth and seventh aspects of the present invention, the method for incorporating the polymer particles into a thermoplastic resin includes a method of forming an emulsion of polymer particles (hereinafter referred to as “polymer emulsion”). , Adding and mixing in the form of a polymer emulsion, and then removing the dispersion medium, or separating and recovering fine powdery polymer particles from the polymer emulsion and adding and mixing these fine powdery particles. Methods and the like can be mentioned.

The molded article of the eighth invention is characterized in that the polymer composition of the sixth or seventh invention is formed into a sheet or film. Such a molded article can be used as a resin film or a resin sheet.
For example, a polyolefin film using a polyolefin as a resin, the composition obtained by the above mixing method or a powder or pellet-like polyolefin, and after sufficiently mixing the polymer particles, by performing normal melt extrusion. Alternatively, it can be produced by uniaxially or biaxially stretching. Also, a polyolefin resin mixed with polymer particles and a polyolefin film containing no particles may be co-extruded to distribute a large number of particles on the film surface to produce a film. The shape and size of such a polyolefin molded article are not particularly limited, and the thickness thereof may be any as long as it can fit into the sheet-like or film-like brass shown above,
As described above, this thickness is approximately 5 μm to 5 mm. The thickness is preferably 6 μm to 1 mm,
More preferably, it can be about 8 to 100 μm. In order to secure transparency sufficiently, it is preferable that the difference between the refractive index of the polymer particles and the refractive index of the thermoplastic resin constituting the film or the like is as small as possible. This difference is 0.4
Or less, more preferably 0.2 or less. The low refractive index difference can be ensured by combining polymer particles containing a (meth) acrylate ester as a main monomer (for example, 60% or more) and a polyolefin such as polypropylene or polyethylene.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be specifically described with reference to examples and comparative examples. In the following, “parts” and “%” indicate “parts by weight” and “% by weight”, respectively. (1) Production of Polymer Particles [Example 1] As an initiator, 3,5,5-trimethylhexanoylperoxyside (trade name “Perloyl 35”)
5 "(manufactured by NOF Corporation) and 2 parts of sodium lauryl sulfate (trade name" Emal 10N ", manufactured by Kao Corporation)
After 0.1 part and 20 parts of water were stirred and emulsified, they were further made into fine particles with an ultrasonic homogenizer. This aqueous dispersion was combined with 1 part of monodisperse polystyrene particles (solid content: 10%) as seed polymer particles having a weight average particle diameter (Dw) of 0.4 μm and a Dw / Dn (number average particle diameter) of 1.0. Acetone 6
And stirred for 1 hour to absorb. Thereafter, 200 parts of a 2.5% aqueous solution of polyvinyl alcohol (trade name “Go-Senol GL-05”, manufactured by Nippon Synthetic Chemical Co., Ltd., degree of polymerization 2000, degree of saponification 87 to 89) as a suspension stabilizer, polymerizable 95 parts of methyl methacrylate and 5 parts of divinylbenzene were added as monomers and added at 40 ° C.
For 1 hour to allow the monomers to be absorbed by the seed particles. Next, the temperature was raised and polymerization was carried out at 70 ° C. for 5 hours. The polymerization conversion was 99%, and hardly any solidified product was generated.

Example 2 Monodispersed poly (methyl methacrylate) as seed polymer particles (weight average particle diameter;
0 μm, Dw / Dn; 1.0, solid content; 10%) 1 part,
90 parts of methyl methacrylate as a polymerizable monomer, 10 parts of trimethylolpropane trimethacrylate (trade name “Light Ester TMP”, manufactured by Kyoeisha Chemical Co., Ltd.), 2.5% aqueous solution of polyvinyl alcohol 1 as a suspension stabilizer
Polymer particles were obtained in the same manner as in Example 1 except that 20 parts and 80 parts of water were used instead.

Example 3 Monodispersed poly (methyl methacrylate) as a seed polymer particle (weight average particle diameter: 0.1%)
5 μm, Dw / Dn; 1.0, solid content; 10%) 1 part,
70 parts of methyl methacrylate, 30 parts of trimethylolpropane trimethacrylate as a polymerizable monomer, 2.5% aqueous solution of sodium carboxymethylcellulose sodium salt as a suspension stabilizer (trade name "Selogen F", manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) ) Polymer particles were obtained in the same manner as in Example 1 except that 40 parts and 160 parts of water were used.

Example 4 The polymer particles obtained in Example 1 as seed polymer particles (weight average particle diameter: 1.9 μm, Dw / Dn: 1.0, solid content: 10
%) 1 part, t-butyl peroxy- as an oil-soluble initiator
2 parts of 2-ethylhexanoate "Perbutyl O" (manufactured by NOF Corporation), styrene 60 as a polymerizable monomer
Parts, trimethylolpropane trimethacrylate 40
Polymer particles were obtained in the same manner as in Example 1 except that 120 parts of a 2.5% aqueous solution of polyvinylpyrrolidone (trade name “K30”, manufactured by BASF) and 80 parts of water were used as suspension stabilizers.

Example 5 Monodisperse polystyrene particles as seed polymer particles (weight average particle diameter: 0.16 μm)
m, Dw / Dn; 1.0, solid content 10%) 2 parts, methyl methacrylate 90 parts as a polymerizable monomer, trimethylolpropane trimethacrylate 10 parts, carboxyl group-containing polyacrylic acid as a suspension stabilizer Polymer particles were obtained in the same manner as in Example 1 except that 40 parts of a 2.5% aqueous solution of sodium salt (trade name “Alon T-25”, manufactured by Toagosei Co., Ltd.) and 160 parts of water were used.

[Comparative Example 1] 3,5,5-
Except for replacing 10 parts of trimethylhexanoyl peroxyside, 99 parts of methyl methacrylate as a polymerizable monomer, 1 part of divinylbenzene, and 600 parts of a 2.5% aqueous solution of polyvinyl alcohol as a suspension stabilizer, all examples were used. Polymer particles were obtained in the same manner as in Example 1.

Comparative Example 2 Without using seed polymer particles, 90 parts of methyl methacrylate as a polymerizable monomer, 10 parts of trimethylolpropane trimethacrylate, 2.5% aqueous solution of polyvinyl alcohol as a suspension stabilizer 4
Polymer particles were obtained in the same manner as in Example 1 except that the amount was changed to 00 parts.

Comparative Example 3 The seed polymer particles used in Example 3 were used, and 2 parts of sodium persulfate was used as an initiator.
80 parts of methyl methacrylate as a polymerizable monomer, 20 parts of trimethylolpropane trimethacrylate, 2.5% aqueous solution of polyvinyl alcohol as a suspension stabilizer 120
Polymer particles were obtained in the same manner as in Example 1 except that the parts were replaced with 80 parts of water.

(2) Performance evaluation of polymer particles Dw and Dn of the seed polymer particles used in Examples 1 to 5 and Comparative Examples 1 to 3 and obtained by Examples 1 to 5 and Comparative Examples 1 and 2. The refractive index, insolubility in toluene, weight average particle diameter, number average particle diameter, and coarse particle amount of each of the obtained polymer particles were measured by the following methods. Table 1 shows the results. Incidentally, in the section of the monomer in Table 1, "M
"MA" is methyl methacrylate, "ST" is styrene,
"DVB" indicates divinylbenzene, and "TMPMA" indicates trimethylolpropane trimethacrylate. Refractive index The dried polymer particles were added to a refractive index standard solution (manufactured by Cargille), and a standard solution (25 ° C.) at which the particles could not be seen under an optical microscope (100 times) was searched for and the refractive index was determined. Insolubility in toluene (%) 1 g of polymer particle powder was added to 100 g of toluene, stirred well at room temperature for one day, and the filtrate obtained by filtering the solution with No5 filter paper was used to determine the polymer dissolution concentration X (%) by a weight drying method. The insolubility was determined by the following equation. Insolubility (%) = 100-X Weight average particle diameter Dw (μm) It was determined by a laser light scattering / particle size distribution analyzer (“LS230” manufactured by Coulter, Inc.). Number average particle diameter Dn (μm) 200 or more particle diameters were measured from a photograph taken with a transmission electron microscope, and the average value was determined. Coarse particle amount Particle counter (Lion's “KL-11 / KS”
−60 ”).

[0037]

[Table 1]

(3) Production of Film Polyolefin films of Examples 6 to 8 and Comparative Examples 4 to 5 were produced by the following method using the polymer particles produced in the above Examples and Comparative Examples. [Examples 6 to 8] 100 parts of polypropylene (melt index: 2 g / 10 minutes), 0.03 part of calcium stearate, and 0.5 part of each of the polymer particles of Examples 1, 2 and 4 were mixed. The mixture was melt extruded and pelletized. This pellet-like mixture is formed into a sheet-like film by using an extruder.
By stretching 0 times, a stretched film having a thickness of 20 μm was produced. In addition, the refractive indexes of the polymer particles of Examples 1, 2, and 4 were 1.49, 1.49, and 1.53, respectively (see Table 1), and the refractive index of polypropylene was 1.49.
It is.

[Comparative Examples 4 and 5] Instead of the polymer particles,
Comparative Example 1 polymer particles and silica particles (Dw = 3 μm)
m, Dn = 2 μm, Dw / Dn = 1.5), and a stretched film having a thickness of 20 μm was produced in the same manner as in Example 6 except that 0.5 part of Dw / Dn = 1.5) was used.

(4) Evaluation of Film Performance Each of the polyolefin films shown in Examples 6 to 8 and Comparative Examples 4 to 5 was evaluated for transparency, blocking resistance and slipperiness by the following methods. . Table 2 shows the results. Transparency Haze (%) was measured according to ASTM D-1003. Blocking resistance Two pieces of film (80 x 120 mm) are 20 m at the upper end
shift by m (overlapping surface: 80 × 10
0 mm) at 50 ° C. while applying a load of 70 g / cm 2.
Was left in the atmosphere for 24 hours, and the shear peel strength (g / cm2) was measured using a tensile tester. Slipperiness The dynamic friction coefficient was measured according to ASTM D-1894.

[0041]

[Table 2]

(5) Effect of Example From the results shown in Table 1, in Examples 1 to 5, particles having a number average particle diameter and a weight average particle diameter of 0.6 to 8.8 μm were smaller than those of a normal emulsion polymerization method. It can be seen that particles having a large diameter are generated, and the generated particles are particles having a very sharp particle diameter distribution, in which the ratio of the weight average particle diameter to the number average particle diameter (Dw / Dn) is 1.0. . On the other hand, in Comparative Example 1 in which the amount of the initiator was as large as 10 parts, the solubility in toluene was as small as 45%. The ratio of the weight average particle diameter to the number average particle diameter (Dw /
Dn) shows a large value of 1.38, and the amount of coarse particles of 20 μm or more is generated as large as 3.5%, indicating that the particle size distribution is wider than those of Examples 1 to 5. .
Further, in Comparative Example 2 in which no seed particles were used, polymer particles having a relatively large particle diameter of 3.0 μm were formed. However, as in Comparative Example 1, the weight relative to the number average particle diameter was large. The ratio (Dw / Dn) of the average particle diameter is extremely large at 1.58, and the amount of the coarse particles of 30 μm or more is 5%.
, It can be seen that the particle size distribution is fairly wide and is unsuitable for use as an antiblocking agent. Furthermore, in Comparative Example 3 in which sodium persulfate was used as the initiator, it was found that the entire polymer particles gelled, and only those which could not exhibit blocking resistance even when added to the resin composition were formed.

On the other hand, from the results shown in Table 2, the films obtained in Examples 6 to 8 were excellent in transparency because they had a small haze as a whole, and were excellent in blocking resistance.
It is understood that the coefficient of kinetic friction is small and the sliding property is excellent. Further, since the difference between the refractive index of the polymer particles and the refractive index of the polypropylene constituting the film is small, it can be seen from this point that the film has excellent transparency. In Comparative Example 5 using inorganic particles conventionally used, Example 6 in which haze is small and transparency was excellent, but blocking resistance and slipperiness were organic polymer particles.
It can be seen that this is considerably inferior to that of ８8. Example 6 (Dw = 1.9 μm) in which the same organic polymer particles are used and the weight average particle diameters are almost the same.
In comparison with Comparative Example 4 (Dw = 1.8 μm), the blocking resistance and the dynamic friction coefficient of Comparative Example 4 are slightly worse than those of Example 6. Also, the ratio of the weight average particle diameter to the number average particle diameter (Dw / Dn), which is an index of the particle diameter distribution.
And the amount of coarse particles were determined in Example 6 (Dw / Dn = 1.0, coarse particle amount 0.1%) and Comparative Example 4 (Dw / Dn = 1.3).
8, the amount of coarse particles is 2%), and the particle size distribution is considerably broader in Comparative Example 4, indicating that Comparative Example 4 has a larger haze and impairs the transparency of the film. . In addition, Example 8 using a particle having a relatively large particle size of 8.8 μm has excellent blocking resistance and slipperiness, but shows poor haze. This indicates that there is a certain limit in the size of the particle diameter in order to balance the various requirements of the transparency, blocking resistance and slipperiness of the film.

In the present invention, the present invention is not limited to the specific embodiments described above, but may be variously modified within the scope of the present invention according to the purpose and application. That is,
The polymer particles of the present invention are not limited to the compositions and compounding ratios shown in Table 1, but may have various compositions and compounding ratios within the scope of the present invention.

[0045]

According to the first to fourth aspects of the present invention, the polymerizable monomer is absorbed after the oil-soluble polymerization initiator is absorbed by the seed polymer particles having a predetermined particle size and particle size distribution. Then, by performing polymerization in the presence of a suspension stabilizer, crosslinkable particles having a larger particle size than ordinary emulsion polymerization and having a sharper particle size distribution than seed polymerization or suspension polymerization can be obtained. According to the fifth to eighth aspects of the present invention, the polymer particles produced as described above are used as a coating composition by adding the polymer particles to a binder, or a polymer such as a polyolefin polymer is used. By blending in a plastic resin matrix and forming or forming a film, it is possible to obtain a high-quality molded product such as a resin film or a resin sheet having excellent blocking resistance, slipperiness and transparency.

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Claims (8)

[Claims] 1. A refractive index of 1.42 to 1.59, an insolubility in toluene of 50% by weight or more, a weight average particle diameter Dw of 0.3 to 30 μm, and a ratio to a number average particle diameter Dn. Dw / Dn is 1.3 or less and the particle size is 10 × Dwμ
Polymer particles having a proportion of coarse polymer particles of m or more less than 3% by weight. 2. The polymer particle according to claim 1, wherein the polymer particle is a polymer of a monomer component comprising a non-crosslinkable monomer and a crosslinkable monomer. 3. The polymer particles according to claim 2, wherein the non-crosslinkable monomer is a (meth) acrylate, or a (meth) acrylate and another monomer. 4. At least a part of 0.1 to 10 parts by weight of an oil-soluble polymerization initiator is added to 100 parts by weight of a monomer component, the weight average particle diameter Dw is 0.05 to 10 μm, and the number average particle diameter is 0.1 to 5 parts by weight of seed polymer particles having a ratio Dw / Dn of 1.2 or less to Dn / Dn are absorbed in an aqueous medium, and then 10 to 95 parts by weight of a non-crosslinkable monomer and a crosslinkable monomer Body 5
A polymer particle according to any one of claims 1 to 3, wherein the polymer particle is produced by absorbing and polymerizing at least a part of a monomer component consisting of 90 to 90 parts by weight. Production method. 5. A coating composition for coating a sheet or film, comprising the polymer particles according to claim 1 and a binder. 6. A polymer composition for a sheet or a film, comprising the polymer particle according to claim 1 and a thermoplastic resin. 7. The polymer composition for a sheet or film according to claim 6, wherein the thermoplastic resin is an olefin resin. 8. A sheet or film obtained by molding the polymer composition according to claim 6 or 7.