JPH0459321B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a method for producing polymer particles in which a filler-free polymer is formed on the surface layer of filler-containing polymer particles. [Prior Art] Polymer particles containing fillers can be used in electrophotography, paints, inks, ion exchange resins, resin molded products, carriers for biological substances, carriers for immobilized enzymes, carriers for immunoserological diagnostic agents, It is used in many fields such as carriers for pharmaceutical administration. Conventional filler-containing polymer particles are generally produced by mixing the filler with a pre-produced polymer, for example by mixing the filler with an organic solvent solution of the polymer. The methods used include spray drying after homogenization, dispersing a polymer solution in water containing a filler and then removing the water and solvent, and kneading the polymer and filler and then pulverizing them. However, these methods require equipment and energy to remove the solvent, and have problems such as the dispersion state of filler particles in the polymer is not uniform and the shape and particle size of the polymer particles are irregular. There were flaws. In order to solve these drawbacks, a method of producing polymer particles by suspension polymerization of monomers in the presence of a filler has also been used. however,
This method also has restrictions in terms of the type and amount of monomers, and the physical properties of the filler contained in the polymer particles are utilized; Applications that require the absence of fillers on the polymer particle surface because they may be exposed, e.g. carriers for adsorption or binding of biological substances such as proteins, enzymes, antigens, antibodies, bacteria, viruses, cells, etc. There were problems such as it being unsuitable when used as such. [Problems to be solved by the invention] Therefore, the problems to be solved by the present invention are as follows.
An object of the present invention is to provide a method for producing polymer particles having high strength, which contain a filler in a well-dispersed state inside the polymer, and which have substantially no filler on the surface. . [Means for Solving the Problems] According to the present invention, a vinyl-based compound comprising () 15-100% by weight of a polyfunctional vinyl-based compound and 85-0% by weight of a lipophilic vinyl-based compound other than the polyfunctional vinyl-based compound; Contains 100 parts by weight of the compound, or () dissolved water-soluble polymer, 15-100% by weight of the polyfunctional vinyl compound and 85-0% by weight of the total amount of the lipophilic vinyl compound and water-insoluble polymer. A filler with a particle size of 30 to 5000 that has been treated to impart lipophilic properties to 100 parts by weight of a vinyl compound consisting of
0.1 to 200 parts by weight were mixed and suspension polymerized in an aqueous phase to obtain filler-containing polymer (a) particles with an average particle size of 0.1 to 300 μm, and then (2) filler was added. In the presence of the contained polymer (A) particles, 5 to 5 parts by weight of the vinyl compound per 100 parts by weight of the polymer (A)
By subjecting 200 parts by weight to suspension polymerization or emulsion polymerization to form a filler-free vinyl compound polymer (b) on the surface layer of the polymer (a) particles, a polymer with an average particle size of 0.1 to 400 μm is produced. A method for producing polymer particles is provided, which is characterized in that coalesced particles are obtained. Next, the present invention will be explained in detail. The vinyl compounds and vinyl compounds used in the present invention are those conventionally used in the production of polymer particles by suspension polymerization or emulsion polymerization. First, among vinyl compounds, polyfunctional vinyl compounds are compounds that have been conventionally used to produce crosslinked polymers by suspension polymerization in an aqueous phase, such as divinylbenzene, vinyl methacrylate, or Ethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, trimethylolpropane,
Examples include compounds having two or more α,β-ethylenically unsaturated bonds in the molecule such as acrylic acid polyesters and methacrylic acid polyesters of polyols such as glycerin, diallyl phthalate, and allyl polyethers of the above polyols. The content of the polyfunctional vinyl compound in the vinyl compound is 15 to 100% by weight, preferably 20 to 100% by weight, more preferably 30 to 100% by weight.
Weight%. If the polyfunctional vinyl compound is less than 15% by weight, the strength of the obtained polymer (a) particles will be insufficient, and there is a risk that they will be destroyed when subjected to ultrasonic treatment, etc.
(b) The filler is localized in the particles, resulting in non-uniform color tone. Next, among vinyl compounds, lipophilic vinyl compounds that can be copolymerized with polyfunctional vinyl compounds include, for example, styrene, α-methylstyrene, ethylstyrene, vinyltoluene,
Aromatic vinyl compounds such as chlorostyrene, unsaturated carboxylic acid esters such as methyl acrylate and methyl methacrylate, unsaturated nitrile compounds such as acrylonitrile and methacrylonitrile, and halogenated materials such as vinyl chloride, vinylidene chloride, and vinyl bromide. Examples include α,β-ethylenically unsaturated compounds such as vinyl compounds. In addition, water-soluble vinyl compounds such as acrylic acid, methacrylic acid, itaconic acid, acrylamide, and methacrylamide may also be used to the extent that they do not inhibit the polymerization reaction, e.g.
10% by weight or less can be copolymerized, and conjugated dienes such as butadiene, isoprene, piperylene, etc. can also be copolymerized as long as the polymer (a) particles do not stick to each other or aggregate. Fillers contained in the polymer (a) particles include, for example, metals such as iron, cobalt, nickel, copper, and aluminum, and combinations of these metals with each other or with other lanthanum series elements such as lanthanum and gadolinium. Alloys with metals, metal oxides such as iron oxide, cobalt oxide, lead oxide, aluminum oxide, zinc oxide, silicon oxide, titanium oxide, magnesium carbonate, calcium carbonate, aluminum silicate,
Metal salts such as barium sulfate, lead carbonate, lead chromate, cobalt aluminate, mercurous chloride, metal sulfides such as zinc sulfide, cadmium sulfide, nickel metallized azo yellow, Retsudrake R, permanent red, 2B, 2G, Examples include pigments such as copper phthalocyanine blue and copper phthalocyanine green, and metal chelate compounds. The particle size of the filler must be smaller than the target filler-containing polymer (a) particles, and is 30 to 5000.
Selected from the range 〓. The surfaces of these fillers are often hydrophilic, and if left as is, the fillers will aggregate with each other in the vinyl compound, making it difficult to uniformly disperse them in the polymer (a) particles. In the present invention, the filler is treated to impart lipophilicity to the surface of the filler so that the filler is uniformly dispersed in the vinyl compound and the filler does not aggregate or precipitate even if left for a long time. is used. Any treatment method may be used to impart lipophilicity to the surface of the filler, but for example, the filler is treated in a medium containing a surfactant whose main component is a fatty acid, and then the filler has a pH of less than 7, preferably 5 or more. A method of washing with an acidic solution of less than 7% can be mentioned. In this case, examples of the surfactant mainly composed of fatty acids include rosin acid,
Alkali metal salts of unsaturated fatty acids such as dodecenoic acid, tetradecenoic acid, hexadecenoic acid, alkali metal salts of saturated fatty acids such as myristic acid, palmitic acid, stearic acid, alagic acid, alkaline earth metal salts of rosin acid, etc. Can be done. In addition, acidic solutions with a pH of less than 7 include lower alcohols such as methanol and ethanol, lower ketones such as acetone and methyl ethyl ketone, and mineral acids such as hydrochloric acid, sulfuric acid, nitric acid, and phosphoric acid.
Examples include pH-adjusted solutions. The temperature for processing fillers in a medium containing fatty acid-based surfactants is usually between 30 and 150 °C.
℃, preferably 70-110℃, and the processing time is
Usually 0.5 to 2 hours, preferably 0.5 to 1 hour. Further, the concentration of the surfactant containing fatty acids as a main component in the medium is not particularly limited, but is usually 0.2% by weight or more, preferably 1 to 1% by weight.
It is 20% by weight. Fillers treated by this method form a layer of fatty acids on the surface, and the hydrophilic groups of the fatty acids are adsorbed onto the surface of the filler, with the lipophilic groups facing outward, making the surface of the filler lipophilic. It is considered that this will be granted. Another treatment method for imparting lipophilicity to a filler is to bring into contact with the filler a compound that has a part with extremely high affinity for the filler and a lipophilic part in its molecule. A method of treating the filler such that the lipophilic portion is bound to the filler by adsorption or chemical bonding, and the lipophilic portion is aligned outward. Examples of such a compound include a silane coupling agent such _as a silane compound as _shown in the following formula (), where R is an alkyl group having 1 to 3 carbon atoms,
R' is an alkyl group with or without a substituent,
It is an alkenyl group or an allyl group, such as -(CH ₂ ) ₃ NH ₂ , -(CH ₂ ) ₃ SH, -(CH ₂ ) ₃ NH-
_C2H5 , -( _CH2 ) _3NH- ( _CH2 ) _2NH -CH _{= CH2} , -( _CH2 ) _3O -C(O)-C( _CH2 )= _CH2 ,

[Formula] - (CH ₂ ) ₃ Cl, n is 1, 2 or 3), titanium coupling agents such as alkoxy titanium compounds as shown in the following formula (), etc. can. (R″) _n TiR〓 _4-n () (R″ is an alkoxy group or a carboxy group with or without a substituent, for example, CH ₃ O
−, C ₂ H ₅ O−, C ₃ H ₇ O−, C ₄ H ₉ O−, CH ₂ CH
( _CH3 )O-,

【formula】

【formula】 etc., R〓 is an alkylcarboxy group, a substituted benzenesulfoxy group, a substituted phenoxy group, an unsaturated carboxy group, an alkyl phosphate group, an alkyl phosphite group,
_{For example, C17H35COO-, CH2=C(CH3)COO-, CH2=CHCOO-, (C18H17O ) 2P ( O ) O- ,}

【formula】

【formula】

[Formula] NH ₂ C ₂ H ₄ NHC ₂ H ₄ O −,

【formula】

[Formula] etc., where m is 1, 2 or 3. ) A method for combining a silane coupling agent or a titanium coupling agent with a filler is, for example, by combining the filler and the silane coupling agent or titanium coupling agent in an inorganic medium such as water or an inorganic medium such as alcohol, ether, ketone, ester, etc. Examples include a method of mixing in an organic medium, heating with stirring, separating the filler after heating by decantation, and removing the inorganic or organic medium by drying under reduced pressure. Alternatively, the silane coupling agent or titanium coupling agent can be bonded to the filler by directly mixing the filler and the silane coupling agent or titanium coupling agent without using an inorganic or organic medium and heating the mixture. It's okay. The heating temperature in these methods is usually 30 to 100°C, and the heating time is about 30 minutes to 2 hours. The amount of silane coupling agent or titanium coupling agent used for the filler is appropriately determined depending on the surface area of the filler, but is usually 1 to 50 parts by weight, preferably 2 to 30 parts by weight, per 100 parts by weight of the filler. Parts by weight. When an inorganic or organic medium is used, the concentration of the silane coupling agent or titanium coupling agent in the medium is not particularly limited;
A further method of imparting lipophilic properties to fillers is in a hydrophobic medium containing compounds with surfactant effects such as fatty acids, alkyl sulfates, alkylaryl sulfonic acids, etc. A method of imparting lipophilicity to the filler by further pulverizing the filler using a crushing device such as a ball mill, and a method of adding water to the filler fine powder produced by a wet method etc. in a hydrophobic medium containing the above-mentioned surfactant. A method in which the dispersion is added and mixed and emulsified, and then water is distilled off by heating to impart lipophilicity to the filler, or a wet method in which the hydrophobic medium containing the surfactant is heated in advance There is a method of imparting lipophilicity to the filler by adding and mixing an aqueous dispersion of fine filler powder produced by the above method and simultaneously distilling off the water. There are various methods for separating the lipophilic filler obtained by these methods from the hydrophobic medium, for example, ethanol, isopropanol, propanol, etc., which are miscible with the hydrophobic medium. The filler can be precipitated by mixing a lower alcohol with a hydrophobic compound containing a lipophilic filler, and the filler can be collected by filtration or decantation. Fillers treated to impart lipophilic properties by these methods are extremely easily and stably dispersed in vinyl compounds, and cause solid-liquid separation such as precipitation and aggregation due to gravity, magnetic force, centrifugal force, etc. It is difficult to do. When forming the polymer (a) particles, the filler is added in an amount of 0.1 to 200 parts by weight per 100 parts by weight of the vinyl compound.
Preferably, 5 to 120 parts by weight are mixed. The filler-containing polymer (a) particles can be produced by, for example, (1) adding a mixture of the above-mentioned vinyl compound and the above-mentioned filler treated to impart lipophilicity to an aqueous phase in the presence of a polymerization initiator and a suspension protectant. or (2) suspending a mixture of the above-mentioned vinyl compound in which a water-insoluble polymer is dissolved and the above-mentioned filler in an aqueous phase in the presence of a polymerization initiator and a suspension protectant. It can be obtained by a manufacturing method by polymerization. The polymerization initiator used in the method (1) or (2) above is selected from organic solvent-soluble polymerization initiators commonly used in the radical polymerization of the above-mentioned vinyl compounds. For example, acyloyl peroxides such as benzoyl peroxide and lauroyl peroxide, aralkyl hydrohaloxides such as cumene hydroperoxide and paramenthane hydroperoxide, alkyl peroxide esters such as t-butyl perbenzoate and i-propyl peracetate, dialkyl-oxides such as -t-butyl peroxide;
Examples include azobisacylotriles such as azobisisobutyronitrile and azobiscyclohexanecarbonitrile. These polymerization initiators are used generally in an amount of 0.1 to 5 parts by weight, preferably 0.5 to 3 parts by weight, per 100 parts by weight of the vinyl compound. In the method (1) or (2) above, a chain transfer agent can be used as necessary to adjust the molecular weight of the polymer. Examples of the chain transfer agent include linear or branched alkyl Examples include mercaptans, halogenated hydrocarbons, etc., and are usually
It is added in an amount of 5% by weight or less based on 100 parts by weight of the above vinyl compound. The suspension protectant used in the method (1) or (2) above is used to protect the suspended state of the vinyl compound in the aqueous phase. Examples of organic suspension protectants include hydrophilic synthetic polymers such as polyvinyl alcohol, polyvinylpyrrolidone, and polyethylene glycol, natural hydrophilic polymers such as gelatin and water-soluble starch, and hydrophilic semi-synthetic polymers such as carboxymethyl cellulose. Examples of inorganic suspending protectants include phosphates such as magnesium, barium or calcium, calcium carbonate, magnesium carbonate, zinc white, aluminum oxide, aluminum hydroxide, etc. can. Furthermore, these suspension protectants can be used in combination with nonionic, anionic, or cationic surfactants. These suspension protectants are usually used in an amount of 0.05 to 30 parts by weight per 100 parts by weight of the vinyl compound, and when used in combination with a surfactant, preferably 2 parts by weight or less per 100 parts by weight of the vinyl compound. use. The water-insoluble polymer used in the method (2) above is a polymer that is soluble in the above-mentioned vinyl compound and insoluble in water, and includes, for example, a polymer of the above-mentioned lipophilic vinyl compound. This water-insoluble polymer is dissolved in the vinyl compound at a concentration of preferably 5 to 60% by weight. When carrying out suspension polymerization of the vinyl compound in which the water-insoluble polymer is dissolved, the concentration of the polyfunctional vinyl compound in the vinyl compound in which the water-insoluble polymer is dissolved is
Must be at least 15% by weight. The suspension polymerization conditions in methods (1) and (2) above are not particularly limited, but for example, the vinyl compound or the vinyl compound in which the water-insoluble polymer is dissolved, the filler, and the polymerization initiator. and an organic phase consisting of a chain transfer agent used as necessary, and an aqueous phase consisting of water, a suspending protectant, and a surfactant used as necessary, are mixed by stirring at a temperature below the polymerization initiation temperature. A method may be mentioned in which, after suspending an organic phase in an aqueous phase as fine droplets with a uniform particle size, the temperature of the suspended system is raised while stirring to initiate polymerization of the vinyl compound. The diameter and particle size distribution of the filler-containing polymer (a) particles obtained by this method are determined by the stirring conditions before the start of polymerization, the type and amount of the suspending protectant and surfactant used as necessary. By appropriately combining these, it is possible to obtain filler-containing polymer (a) particles having a desired average particle diameter of 0.1 to 300 μm and a preferred particle size distribution. The amount of the aqueous phase to be used relative to the organic phase is not particularly limited, but is usually 100 parts by weight of the organic phase.
The amount is 100 to 2000 parts by weight, preferably 200 to 1000 parts by weight. The temperature at which the suspension system is heated to polymerize the vinyl compound can be determined as appropriate depending on the vinyl compound and the type and amount of the polymerization initiator used, but it is usually 30~150
℃, preferably 40 to 100℃. After polymerization, the filler-containing polymer (A) particles can be separated by centrifugation or other operations, and the separated polymer (A) particles can be treated with water, ethanol, acetone, etc. as necessary. Washed using The polymer particles that are the object of the present invention are produced by forming a filler-free polymer (b) on the surface layer of the filler-containing polymer (b) particles obtained as described above. be done. Examples of the vinyl compounds forming the filler-free polymer (b) include vinyl compounds forming the filler-containing polymer (b) particles (i.e., polyfunctional vinyl compounds and lipophilic vinyl compounds). ), but a polyfunctional vinyl compound is not essential, and a water-soluble vinyl compound can also be included as a comonomer. Furthermore, vinyl compounds can also be copolymerized with conjugated diene compounds. In addition, when copolymerizing a water-soluble vinyl compound, the copolymerization amount is such that the obtained copolymer does not become water-soluble, for example, 50% by weight or less, preferably 30% by weight or less.
% by weight or less. The ratio of the polymer (a) in the particles of the polymer (a) containing a filler to the polymer (b) that does not contain a filler is (a)/(b).
100/5 to 200 (weight ratio), preferably (a)/
(B) is 100/5 to 150 (weight ratio), particularly preferably (B)/
(b) is 100/20 to 100 (weight ratio). Polymer (a) 100
If the amount of polymer (b) is less than 5 parts by weight, the surface of the polymer (b) particles may not be completely covered by the polymer (b), and the polymer (b) particles Surfaces may be exposed. Also, if the amount of polymer (b) exceeds 200 parts by weight relative to 100 parts by weight of polymer (a), the polymer (b)
The shell layer becomes very thick and the physical properties of the filler inside cannot be fully utilized. The particle size of the polymer particles obtained by the present invention is 0.1 to 400 μm, preferably 0.1 to 300 μm. The suspension polymerization method and emulsion polymerization method for forming the polymer (b) are not particularly limited, but may be carried out, for example, as follows. (a) Suspension polymerization method Polymer (a) particles containing a filler are dispersed in an organic layer consisting of a vinyl compound, a polymerization initiator, and a chain transfer agent used as necessary, and then suspended. It is dispersed in an aqueous phase at a temperature below the polymerization initiation temperature in the presence of a protective agent. After obtaining droplets of the organic phase with the desired particle size by varying the concentration of the suspending protectant and stirring speed, the polymer is formed by increasing the temperature to initiate polymerization.
(a) Forming a polymer (b) on the surface layer of the particles. The polymerization initiator, chain transfer agent, suspending protectant, etc., polymerization conditions, etc. are the same as in the case of the filler-containing polymer (a) particles described above. (b) Emulsion polymerization method Polymer (a) particles containing a filler are dispersed in an aqueous phase containing a polymerization initiator, and a vinyl compound to be formed into a polymer (b) is charged all at once or continuously in an emulsified state. Polymerize. Polymerization initiators used in this case include peroxides such as persulfate, hydrogen peroxide, metal peroxide, acyloyl peroxide, aralkyl hydroperoxide, and the reaction of a peroxide with a reducing agent in the presence of an iron salt. Examples include radical-generating polymerization initiators commonly used in emulsion polymerization, such as so-called redox catalysts. Examples of the reducing agent include sodium sulfite, sodium thiosulfite, and sodium metabisulfite. Other polymerization aids commonly used in emulsion polymerization may also be used, such as molecular weight regulators such as t-dodecylmercaptan and carbon tetrachloride, and chelating agents such as sodium ethylenediaminetetraacetate. An emulsifier is not necessarily required, but when used, it is usually used in an amount of about 1 part by weight or less, preferably 0.1 part by weight or less, per 100 parts by weight of the vinyl compound. As emulsifiers, anionic surfactants such as sodium dodecylbenzenesulfonate and potassium oleate, and nonionic surfactants such as polyoxyethylene lauryl ether and polyoxyethylene nonyl phenyl ether can be used alone or in combination. can. The pH during polymerization is not particularly limited, but is usually in the range of 2 to 10. Further, the polymerization temperature is not particularly limited as long as it is within a range where ordinary emulsion polymerization can be carried out, but a range of 30 to 100°C is suitable. The polymer particles obtained by the present invention have a three-dimensional structure in which the filler-containing polymer (a) particles under the surface layer are crosslinked, so the particle strength is significantly increased, and it can be treated by various treatments, such as ultrasonic treatment. It has the characteristic that it hardly breaks down even when exposed to water. Further, the polymer particles obtained by the present invention can utilize the physical properties of the filler contained therein, and moreover, the particle surface is formed of a polymer containing no filler. The polymers that make up the surface of the polymer particles can be freely combined, whether they are nonpolar or polar with functional groups.
The surface performance of the polymer particles can be fully exhibited. For example, when fine particles of a high-density substance are used as a filler, polymer particles having a high apparent density and a surface consisting only of a polymer containing no filler can be obtained. The polymer particles can be easily separated from the surrounding liquid medium using gravity or centrifugal force, making them extremely useful as ion exchange resins, carriers for immunoreactive substances, carriers for enzymes, carriers for biological substances, etc. be. In addition, when a magnetic filler is used, polymer particles can be separated by magnetic force,
It becomes possible to move it in a liquid medium, within an organism or within a container. These polymer particles can be used not only for the same purposes as the above-mentioned high-density polymer particles but also as a carrier for pharmaceutical administration. As described above, according to the present invention, it is possible to utilize the physical properties of fillers, and in addition, the chemical properties of the polymer constituting the surface of the polymer particles can be changed depending on the desired purpose. is provided. These polymer particles have small dimensions, so they have a large surface area per unit volume;
It is considered to be particularly ideal as a carrier that utilizes the surface of the polymer. [Examples] Hereinafter, the present invention will be explained in more detail using Examples. Example 1 An average particle size of 100〓 prepared by wet method
400 ml of a 20% by weight aqueous solution of potassium oleate was added to water 1 containing 100 g of Fe ₃ O ₄ particles, and the mixture was stirred at 90° C. for 30 minutes. After cooling, adjust the mixture to pH 6 using dilute hydrochloric acid. _Fe3O4 particles aggregate, so filter _them and
2 times with 300 ml of warm water at ℃, 2 times with 300 ml of ethanol
It was washed twice and dried under reduced pressure. In a 24-necked flask equipped with a stirrer, reflux condenser, addition funnel, and thermometer, a 3% by weight aqueous solution of polyvinyl alcohol was added.
ml, separately 150 g of styrene, 150 g of divinylbenzene, 6 g of benzoyl peroxide, t-
3.0 g of dodecyl mercaptan and 60 g of Fe ₃ O ₄ particles, which had been rendered lipophilic by treatment with the potassium orenate obtained above, were preliminarily heated at 3000 rpm under ice-cooling.
The mixture was stirred to be uniformly mixed, and the mixture was dropped from a dropping funnel into a four-necked flask in which the aqueous polyvinyl alcohol solution was being stirred. After the dropwise addition was completed, stirring was continued for 30 minutes, and when the particle size of the organic phase reached 3.5 μm, the temperature was raised to 80° C. and polymerization was carried out for 5 hours. Thereafter, unreacted monomers were collected under reduced pressure, and the polymer particles were centrifuged and washed three times with 500 ml of warm water. As a result, 320 g of filler-containing polymer (a) particles were obtained. As a result of measuring this with a microscope, the average particle size was 3.5 μm.
It had a perfect spherical shape and a uniform color tone throughout. Furthermore, 400 ml of a 3% by weight aqueous solution of polyvinyl alcohol was added to a 4-necked flask equipped with a stirrer, a reflux condenser, a dropping funnel, and a thermometer. Separately, 80 g of styrene, 20 g of acrylonitrile, 2 g of benzoyl peroxide, t-dodecyl mercaptan
1.0 g and 100 g of the polymer (a) particles obtained above were mixed uniformly by stirring at 600 rpm under ice-cooling, and the mixture was stirred for 30 minutes at 3500 rpm under ice-cooling, until the particle size of the organic phase was reduced. When the thickness reached 7 μm, the temperature was raised to 85° C. and polymerization was carried out for 5 hours. Thereafter, unreacted monomers were collected under reduced pressure, and the polymer particles were centrifuged and washed three times with 500 ml of warm water. 185 g of polymer particles were produced. As a result of measuring with a microscope, the average particle size
It was 4.4 μm. ESCA (Elctron
The elements present on the surface of the produced polymer particles were investigated using spectroscopy for chemical analysis. The results showed that only the carbon derived from the polymer and the oxygen in the air adsorbed on the polymer surface were absorbed.
The presence of iron element was not recognized. The polymer particles were attracted by a magnet. Example 2 Polymer (a) particles containing filler obtained in Example 1
For 100g, 30g styrene, 10g methacrylic acid
g, 2 g of benzoyl peroxide, and 0.3 g of t-dodecyl mercaptan were mixed and polymerized in the same manner as in Example 1 to obtain polymer particles. Polymerization conversion rate is 80%
It was hot. The polymer particle surface was prepared in the same manner as in Example 1.
As a result of measurement using ESCA, the presence of carbon and oxygen was confirmed on the surface of the polymer particles, and no iron was observed. The polymer particles were attracted by a magnet and had an average particle diameter of 3.9 μm. Example 3 Water 1 containing 100 g of lead oxide particles with an average particle size of 200〓
is a silane coupling agent. A solution of 20 ml dissolved in 200 ml of ethanol was added dropwise at room temperature with stirring. The mixture was heated to reflux for 1 hour while stirring. After cooling, this mixed solution was added to ethanol 3 with stirring, and then the precipitate was filtered, washed twice with 300 ml of ethanol, and dried under reduced pressure. In place of 60 g of Fe ₃ O ₄ particles treated with potassium oleate to impart lipophilicity in Example 1, 60 g of lead oxide particles imparted to lipophilicity by treatment with the silane coupling agent obtained above were used. Suspension polymerization was carried out in the same manner as in Example 1, except that 325 g of filler-containing polymer (a) particles having an average particle diameter of 3.6 μm were obtained. Separately, 400 ml of a 2.5% by weight aqueous solution of polyvinyl alcohol was added to a 4-necked flask equipped with a stirrer, a reflux condenser, a dropping funnel, and a thermometer. Additionally, 100 g of styrene, 20 g of isoprene, 3.5 g of benzoyl peroxide, and 0.5 g of t-todecyl mercaptan.
g and 100 g of the polymer (a) particles obtained above were added;
The mixture was mixed and stirred at 3500 rpm for 30 minutes under ice cooling, and when the average particle size of the organic phase reached 7.0 μm, the temperature was raised to 85° C. and polymerized for 5 hours. Unreacted monomers were collected under reduced pressure, and the polymer particles were centrifuged at 500 °C.
Washed three times with ml of warm water. 205 g of polymer particles were produced. As a result of measurement using a microscope, the average particle diameter was 4.7 μm. ESCA as in Example 1
As a result of measurements using a polymer particle, the presence of carbon and oxygen was confirmed on the surface of the polymer particles, but no iron was observed. The density of the obtained polymer particles was measured using a conventional float-sink method. The density was 1.28 g/ml. Example 4 Polymer (a) particles containing filler obtained in Example 1
Disperse 100g in 350ml of water, then add methacrylic acid 5
g and 95 g of styrene were added, and the temperature was raised to 80° C. while stirring. Then add 0.5g of potassium persulfate and heat at 80℃ for 6 hours.
Polymer particles were obtained by polymerization for a period of time. Polymerization conversion rate is 95
It was %. The polymer particle surface was prepared in the same manner as in Example 1.
As a result of measurement using ESCA, the presence of carbon and oxygen was confirmed on the surface of the polymer particles, and no iron was observed. The obtained polymer particles were attracted by a magnet and had an average particle diameter of 4.5 μm. Reference Example 1 800 ml of a 3% by weight aqueous solution of polyvinyl alcohol was added to a 4-neck flask equipped with a stirrer, a reflux condenser, a dropping funnel, and a thermometer. Separately styrene
150g, divinylbenzene 150g, benzoyl peroxide 6g, t-dodecylmercaptan 3.0g
60 g of the Fe ₃ O ₄ particles (particles not imparted with lipophilic properties) used in Example 1 were uniformly mixed in advance using ultrasonic waves under ice cooling, and a mixed solution was added to the dropping funnel.
Polyvinyl alcohol was added dropwise to a 4-necked flask while being stirred. Continue stirring for 30 minutes after the addition is complete.
Then, the temperature was raised to 80°C and polymerization was carried out for 5 hours. After that, unreacted monomers are collected under reduced pressure, and the polymer is centrifuged.
Washed three times with 500 ml of warm water. At this time, 57 g of Fe ₃ O ₄ particles that were not incorporated into the polymer particles were recovered. [Effects of the Invention] According to the present invention, the particle strength is improved by forming a polymer that contains a filler in a well-dispersed state inside the polymer particles and does not contain a filler on the surface of the polymer particles. can provide large polymer particles.

Claims (1)

[Scope of Claims] 1 () 100 parts by weight of a vinyl compound consisting of 15 to 100% by weight of a polyfunctional vinyl compound and 85 to 0% by weight of a lipophilic vinyl compound other than the polyfunctional vinyl compound, or ( ) Contains dissolved water-insoluble polymer, polyfunctional vinyl compound 15~
100 parts by weight of a vinyl compound consisting of 100% by weight and a total amount of lipophilic vinyl compounds other than the polyfunctional vinyl compound and a water-insoluble polymer of 85 to 0% by weight were treated to impart lipophilicity. The particle size is
0.1 to 200 parts by weight of a filler with a particle size of 30 to 5000 Å is mixed and suspension polymerized in an aqueous phase to obtain an average particle diameter of 0.1 to 200 parts by weight.
Obtain 300 μm filler-containing polymer (a) particles,
2. In the presence of polymer (A) particles containing a filler, 5 to 200 parts of a vinyl compound is added to 100 parts by weight of polymer (A).
Part by weight is subjected to suspension polymerization or emulsion polymerization to obtain polymer (a).
By forming a polymer (b) of a vinyl compound that does not contain a filler on the surface layer of the particles, the average particle diameter can be
A method for producing polymer particles, characterized in that polymer particles having a size of 0.1 to 400 μm are obtained.