KR20240028518A - Resin fine particles and method for producing the same - Google Patents

Abstract

The object is to provide resin fine particles with excellent heat resistance and transparency, narrow particle size distribution, and small particle diameter. As a solution, a hydrolyzable silicon compound unit having a group that reacts with a hydrolyzable silyl group and a radically polymerizable unsaturated group, a monofunctional (meth)acrylic monomer unit, a polyfunctional (meth)acrylic monomer unit, and a thiol-based compound unit. Resin fine particles are provided.

Description

Resin fine particles and method for producing the same

The present invention relates to resin fine particles and a method for producing the same. In detail, (a) a hydrolyzable silicon compound unit having a hydrolyzable silyl group and a group that reacts with a radically polymerizable unsaturated group, (b) a monofunctional (meth)acrylic monomer unit, (c) a polyfunctional (meth)acrylic monomer unit. , and (d) resin fine particles containing a thiol-based compound unit, and a method for producing the resin fine particles.

Resin films have long been widely used as packaging materials. In recent years, its uses are further expanding, and the properties required for resin films are becoming more advanced, especially in optical member applications and electronic device applications. And, there is a demand to increase productivity while maintaining the high quality.

In many cases, the resin film is stored in roll shape. When stored in a roll shape, there is a risk that the resin films may adhere to each other at the overlapping portion, resulting in poor slipperiness and peelability. In response to this problem, it is known to add various fillers such as organic particles and inorganic particles to the resin film as an anti-sticking agent (anti-blocking agent). Representative fillers include silica for inorganic particles and (meth)acrylic resin fine particles for organic particles.

When inorganic particles are used as fillers, the advantages include high hardness and the ability to provide anti-sticking properties by adding a small amount. However, due to its material, there is a disadvantage in that a difference in refractive index occurs between it and the resin film, which becomes a factor that impairs transparency.

On the other hand, when organic particles are used as fillers, an advantage is that anti-sticking properties can be provided while maintaining transparency of the resin film. For this reason, various organic particles are being developed, and thus are also used in resin films that require high quality.

Patent Document 1 describes using organic polymer particles containing an antioxidant as an anti-blocking agent for films. Heat resistance can be improved by making the organic polymer particles contain an antioxidant.

Patent Document 2 describes silicone-based polymer particles in a core-shell shape that maintain high transparency and hardness.

Patent Document 3 describes swollen seed polymer particles using polysiloxane particles as seed particles.

Japanese Patent No. 5572383 Publication Japanese Patent Publication No. 2009-173694 Japanese Patent No. 5599674 Publication

When using organic particles, especially resin fine particles, as an anti-sticking agent (anti-blocking agent) for optical films, etc., it is known that narrow particle size distribution and smaller particle diameter are preferable because they have less influence on film haze. Additionally, when using resin fine particles as an anti-sticking agent (anti-blocking agent), there is a problem that resin residue is generated due to heat load applied during resin compounding, etc., and the yield during film production deteriorates. For this reason, it is necessary to use resin fine particles that are resistant to heat load and have excellent heat resistance.

The organic polymer particles described in Patent Document 1 contain an antioxidant. Antioxidants with a high antioxidant function often have bulky molecular structures, so they are difficult to apply to polymerization methods using water as a medium other than suspension polymerization. For this reason, it is difficult to obtain organic polymer particles that have sufficient properties in terms of particle size distribution and particle diameter and have more precise optical properties.

The polymer particles described in Patent Document 2 are expected to have optical properties compared to inorganic particles, but since they are composed of a silicone-based polymer, there is a risk that a difference in refractive index occurs within the film due to the silicone component and the haze increases. For this reason, it is difficult to produce polymer particles with high transparency.

The swollen seed polymer particles described in Patent Document 3 are produced by sol-gel seed polymerization using polysiloxane particles as seed particles, and better optical properties can be expected. On the other hand, the hurdles for required properties such as transparency are increasing for recent optical films, and the influence of polysiloxane seed particle portions on film haze cannot be ignored, making it difficult to produce highly transparent swollen seed polymer particles.

The problem that the present invention seeks to solve is to provide resin fine particles with excellent heat resistance and transparency, narrow particle size distribution, and small particle diameter.

As a result of careful study to solve the above problems, the inventors found (a) a hydrolyzable silicon compound unit having a reactive group copolymerizable with a vinyl monomer, (b) a monofunctional (meth)acrylic monomer unit, (c) a polyfunctional (meth) ) It was found that the above problem could be solved by resin fine particles containing an acrylic monomer unit and (d) a thiol-based compound unit, and the present invention was completed.

That is, the present invention provides the following resin fine particles and a method for producing the resin fine particles.

Item 1: (a) a hydrolyzable silicon compound unit having a group that reacts with a hydrolyzable silyl group and a radically polymerizable unsaturated group, (b) a monofunctional (meth)acrylic monomer unit, (c) a polyfunctional (meth)acrylic monomer unit, and (d) resin fine particles containing a thiol-based compound unit.

Item 2: The resin fine particles according to Item 1, wherein the content of silicon element in the resin fine particles as measured by fluorescence X-ray analysis is 0.03% by mass or more and 1% by mass or less.

Item 3: (e) The resin fine particles according to Item 1 or 2, further comprising a monofunctional vinyl monomer unit having an aromatic ring in the molecular structure.

Item 4: The resin fine particles according to any one of Items 1 to 3, wherein the (b) monofunctional (meth)acrylic monomer unit includes an alkyl (meth)acrylate unit having an alkyl group of 2 or more carbon atoms.

Item 5: The resin fine particles according to any one of Items 1 to 4, wherein the resin fine particles have a heat loss ratio of 2.5% or less when heat-treated at 280°C for 1 hour in a nitrogen atmosphere.

Item 6: The resin fine particles according to any one of Items 1 to 5, wherein the 3% thermal decomposition temperature in a nitrogen atmosphere is 350°C or higher.

Item 7: The resin fine particles according to any one of Items 1 to 6, wherein the volume average particle diameter is 0.05 μm or more and 3 μm or less.

Item 8: The resin fine particles according to any one of Items 1 to 7, wherein the coefficient of variation of the volume average particle diameter is 25% or less.

Clause 9: The following measurement ranges;

(measurement range)

Measurement range of particle diameter: 0.5㎛∼200㎛,

Measurement range of particle circularity: 0.97∼1.00

The resin fine particles according to any one of items 1 to 8, wherein the number of particles 5 μm or larger is 1 or less among 300,000 resin fine particles.

Item 10: (f) The resin fine particles according to any one of Items 1 to 9, further comprising a reactive surfactant unit.

Item 11: A resin fine particle assembly comprised by agglomerating a plurality of the resin fine particles according to any one of Items 1 to 10.

Item 12: The resin fine particles according to any one of Items 1 to 11, which are used as an anti-sticking agent for resin films.

Item 13: The resin fine particles according to Item 12, wherein the resin film is a resin film for optical use.

Item 14: A first step of creating seed particles by emulsion polymerization or soap-free polymerization of a monomer component containing a monofunctional (meth)acrylic monomer, and

A mixture containing a hydrolyzable silicon compound having a group that reacts with a hydrolyzable silyl group and a radically polymerizable unsaturated group, a monofunctional (meth)acrylic monomer, a polyfunctional (meth)acrylic monomer, and a thiol-based compound is absorbed into the seed particles. A method for producing resin fine particles, comprising a second step of polymerization.

Item 15: The method for producing resin fine particles according to Item 14, wherein the mixture used in the second step further contains a monofunctional vinyl monomer having an aromatic ring in the molecular structure.

Item 16: The method for producing resin fine particles according to Item 14 or 15, comprising a step of classifying the obtained resin fine particles through a filter with an absolute filtration accuracy of 5 μm or less.

Item 17: A method for producing resin fine particles, comprising granulating and drying the resin fine particles obtained by the method for producing resin fine particles according to any one of Items 14 to 16.

According to the present invention, it is possible to provide resin fine particles that are excellent in heat resistance and transparency, have a narrow particle size distribution, and have a small particle diameter. By using these resin fine particles as an anti-stick agent for resin films, especially as an anti-stick agent for resin films for optical applications, it becomes possible to stably produce highly transparent resin films for optical applications.

Hereinafter, the resin fine particles of the present invention and the method for producing the resin fine particles will be described in detail.

In this specification, (meth)acrylic monomer refers to an acrylic monomer or methacrylic monomer, and (meth)acrylate refers to acrylate or methacrylate.

[Resin fine particles]

The resin fine particles of the present invention are (a) a hydrolyzable silicon compound unit having a hydrolyzable silyl group and a group that reacts with a radically polymerizable unsaturated group, (b) a monofunctional (meth)acrylic monomer unit, (c) a polyfunctional (meth)acrylic monomer unit. It is a resin fine particle containing a monomer unit and (d) a thiol-based compound unit.

The resin fine particles of the present invention may further contain (e) a monofunctional vinyl monomer unit having an aromatic ring in the molecular structure and/or (f) a reactive surfactant unit.

＜(a) Unit＞

The unit (a) in the resin fine particles of the present invention is a unit derived from a hydrolyzable silicon compound having a group that reacts with a hydrolyzable silyl group and a radically polymerizable unsaturated group.

The hydrolyzable silyl group contained in the hydrolyzable silicon compound is one in which 1 to 3 hydrolyzable groups are bonded to a silicon atom. In the presence of moisture or a cross-linking agent, a condensation reaction occurs using a catalyst, etc., if necessary, to form a siloxane bond. It is a silicon-containing group that can be crosslinked.

The hydrolyzable group of the hydrolyzable silyl group is not particularly limited and includes, for example, hydrogen atom, halogen atom, hydroxyl group, alkoxy group, phenoxy group, aryloxy group, acyloxy group, ketoximate group, amino group, and amide group. , acid amide group, aminooxy group, iminoxy group, mercapto group, alkenyloxy group, oxime group, and the like. Among them, an alkoxysilyl group is preferable because the hydrolysis reaction is mild and it is easy to handle. Examples of the alkoxysilyl group include trialkoxysilyl groups such as trimethoxysilyl group, triethoxysilyl group, triisopropoxysilyl group, and triphenoxysilyl group; dialkoxysilyl groups such as propyldimethoxysilyl group, methyldimethoxysilyl group, and methyldiethoxysilyl group; And monoalkoxysilyl groups such as dimethylmethoxysilyl group and dimethylethoxysilyl group can be mentioned. Preferably, it is a trialkoxysilyl group, and more preferably, it is a trimethoxysilyl group and a triethoxysilyl group.

Groups other than the hydrolyzable group bonded to the silicon atom in the hydrolyzable silyl group are not particularly limited. For example, selected from the group consisting of alkyl groups with 20 or less carbon atoms such as methyl, ethyl, propyl, and isopropyl groups, alkenyl groups with 20 or less carbon atoms, aryl groups with 6 to 30 carbon atoms, and arylalkyl groups with 7 to 30 carbon atoms. One or more types may be mentioned.

The group that reacts with the radically polymerizable unsaturated group of the hydrolyzable silicon compound is not particularly limited as long as it is a group that reacts with radically polymerizable unsaturated groups such as (meth)acryloyl group, (meth)acrylamide group, vinyl group, and styryl group. No.

Groups that react with the radically polymerizable unsaturated group of the hydrolyzable silicon compound of the present invention include, for example, radically polymerizable unsaturated groups such as (meth)acryloyl group, (meth)acrylamide group, vinyl group, and styryl group, One or more types selected from the group consisting of mercapto group, hydroxyl group, amino group, etc. can be mentioned.

In the present invention, the hydrolyzable silicon compound having a group that reacts with a hydrolyzable silyl group and a radically polymerizable unsaturated group includes, for example, vinyltrimethoxysilane, vinyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltri One or more types selected from the group consisting of methoxysilane, 3-mercaptopropylmethyldimethoxysilane, and 3-mercaptopropyltrimethoxysilane can be mentioned. These may be used individually, or two or more types may be mixed and used.

＜(b) Unit＞

The unit (b) in the resin fine particles of the present invention is a unit derived from a monofunctional (meth)acrylic monomer.

The monofunctional (meth)acrylic monomer is not particularly limited as long as it is a compound having only one (meth)acryloyl group in the molecule. For example, methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, s- (meth)acrylate. Butyl, t-butyl (meth)acrylate, pentyl (meth)acrylate, isopentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, Isooctyl (meth)acrylate, nonyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate, (meth)acrylate ) Tridecyl acrylate, tetradecyl (meth)acrylate, pentadecyl (meth)acrylate, hexadecyl (meth)acrylate, heptadecyl (meth)acrylate, octadecyl (meth)acrylate, isostearyl (meth)acrylate, (meth)acrylate ) (meth)acrylic acid alkyl esters having 1 to 20 alkyl carbon atoms, such as nonadecyl acrylate and eicosyl (meth)acrylate; (meth)acrylic acid alicyclic esters having an alicyclic structure in the ester portion, such as cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, and dicyclopentanyl (meth)acrylate; One or more types selected from the group consisting of etc. can be mentioned. Preferably, methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, s- (meth)acrylate. Butyl, t-butyl (meth)acrylate, pentyl (meth)acrylate, isopentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, One or more alkyl (meth)acrylic acid esters having 1 to 10 alkyl carbon atoms, such as isooctyl (meth)acrylate, nonyl (meth)acrylate, isononyl (meth)acrylate, and decyl (meth)acrylate, are universal and preferred, For applications requiring heat resistance, alkyl groups having 2 or more carbon atoms such as butyl (meth)acrylate, alkyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, and dicyclofentanyl (meth)acrylate are used. Meth) alkyl esters of acrylic acid are particularly preferred. These monofunctional (meth)acrylic monomers may be used individually or in combination of two or more types.

＜(c) Unit＞

The (c) unit in the resin fine particles of the present invention is a unit derived from a polyfunctional (meth)acrylic monomer.

The polyfunctional (meth)acrylic monomer is not particularly limited as long as it is a compound having two or more radically polymerizable unsaturated groups such as a (meth)acryloyl group in the molecule. For example, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, decaethylene glycol di(meth)acrylate, pentadecaethylene glycol di(meth)acrylate ) Acrylate, pentaconta hetaethylene glycol di(meth)acrylate, 1,3-butylene di(meth)acrylate, allyl(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tetraacrylate and dipentaerythritol hexa(meth)acrylate. Among these, ethylene glycol di(meth)acrylate (especially ethylene glycol dimethacrylate) and allyl (meth)acrylate (allyl methacrylate) are preferable. These polyfunctional (meth)acrylic monomers may be used individually or in combination of two or more types.

＜(d) Unit＞

The unit (d) in the resin fine particles of the present invention is a unit derived from a thiol-based compound.

The thiol-based compound is not particularly limited as long as it is a compound having a thiol group in the molecule, and includes monofunctional thiol-based compounds and polyfunctional thiol-based compounds.

The thiol-based compound functions as a chain transfer agent and becomes a structural unit of polymer fine particles. The thiol-based compound is a growth polymer in a radical polymerization system in which a hydrolyzable silicon compound having a group that reacts with a hydrolyzable silyl group and a radically polymerizable unsaturated group, a monofunctional (meth)acrylic monomer, and a polyfunctional (meth)acrylic monomer are polymerized. By accepting radicals from the chain, the elongation of the polymer chain is stopped and new radicals are generated to initiate the growth reaction of other polymer chains. As a result, it becomes possible to keep the molecular weight of the resin fine particles constant, and it becomes possible to keep the particle size distribution constant.

The monofunctional thiol-based compound is not particularly limited as long as it is a compound having one thiol group in the molecule. For example, thiol compounds such as 1-butanethiol, 1-octanethiol, 1-decanethiol, 1-dodecanethiol, 1-hexadecanethiol, and tert-dodecanethiol; One or more types selected from the group consisting of acid compounds having a thiol group such as thioglycolic acid, 3-mercaptopropionic acid, mercaptosuccinic acid, or esters thereof, etc. can be mentioned. These monofunctional thiol-based compounds may be used individually, or two or more types may be mixed.

The polyfunctional thiol-based compound is not particularly limited as long as it is a compound having two or more thiol groups in the molecule. For example, 1,2-ethanedithiol, 1,3-propanedithiol, 1,4-butanedithiol, 1,6-hexanedithiol, 1,8-octanedithiol, 1,2-cyclohexane Dithiol, decanedithiol, ethylene glycol bisthioglycolate, ethylene glycol bisthiopropionate, ethylene glycol bisthioglycolate (EGTG), 1,4-butanediol bisthiopropionate (BDTP), trimethylolpropane tris. Thioglycolate (TMTG), trimethylolpropane trithiopropionate, pentaerythritol tetrakistioglycolate (PETG), pentaerythritol tetrakistiopropionate, dipentaerythritol hexathiopropionate, trimercaptopropionic acid (2-hydroxyethyl)isocyanurate, 1,4-dimethylmercaptobenzene, 2,4,6-trimercapto-s-triazine, 2-(N,N-dibutylamino)-4, One or more types selected from the group consisting of 6-dimercapto-s-triazine and the like can be mentioned. These polyfunctional thiol-based compounds may be used individually or in combination of two or more types.

Among these, ethylene glycol bisthioglycolate (EGTG), 1,4-butanediol bisthiopropionate (BDTP), trimethylolpropane tristioglycolate (TMTG), and pentaerythritol tetrakystioglycolate (PETG). At least one type selected from the group is preferred.

＜(e) Unit＞

The resin fine particles of the present invention may contain units (e) in addition to units (a) to (d).

(e) The unit is a unit derived from a monofunctional vinyl monomer having an aromatic ring in the molecular structure.

Monofunctional vinyl monomers having an aromatic ring in the molecular structure include an aromatic ring in the molecule and radically polymerizable unsaturated groups such as (meth)acryloyl group, (meth)acrylamide group, vinyl group, and styryl group. It is a monomer with one unit. For example, one or more types selected from the group consisting of monofunctional aromatic hydrocarbon monomers, polyfunctional aromatic hydrocarbon monomers, aromatic ring-containing (meth)acrylic acid ester monomers, etc. Monofunctional vinyl monomer units having an aromatic ring in their molecular structure may be used individually or in combination of two or more types.

Monofunctional aromatic hydrocarbon monomers include, for example, styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene (vinyltoluene), α-methylstyrene, m-ethylvinylbenzene, p-ethylvinylbenzene, One or more types selected from the group consisting of styrenesulfonates such as vinylbenzoic acid, styrenesulfonic acid, sodium styrenesulfonate, and ammonium styrenesulfonate, vinylnaphthalene, and allylbenzene. Among these, styrene, α-methylstyrene, and sodium styrenesulfonate are preferable. These monofunctional aromatic hydrocarbon monomers may be used individually or in combination of two or more types.

Examples of aromatic ring-containing (meth)acrylic acid ester monomers include benzyl (meth)acrylate, phenyl (meth)acrylate, phenoxyethyl (meth)acrylate, and 2-(meth)acryloyloxyethyl phthalic acid. One or more types selected from the group consisting of (meth)acrylic acid esters having an aromatic ring in the molecular structure, etc. can be mentioned. Meanwhile, in the present invention, (meth)acrylic acid ester monomers having an aromatic ring in the molecular structure, such as benzyl (meth)acrylate, are treated as “monofunctional vinyl monomers having an aromatic ring in the molecular structure.”

＜(f) Unit＞

The resin fine particles of the present invention may contain units (f) in addition to units (a) to (d).

(f) The unit is a unit derived from a reactive surfactant.

Examples of the reactive surfactant include at least one selected from the group consisting of anionic reactive surfactants and nonionic reactive surfactants. The anionic reactive surfactant may include at least one selected from the group consisting of anionic reactive surfactants listed in <Surfactant> in the "Method for Producing Resin Fine Particles" described later. The nonionic reactive surfactant may include at least one selected from the group consisting of nonionic reactive surfactants listed in <Surfactant> in the [Method for Producing Resin Fine Particles] described later.

＜Other units＞

The resin fine particles of the present invention may contain units other than units (a) to (f) (hereinafter referred to as “other units”).

Other units include, for example, fatty acid vinyl ester monomers, halogenated olefin monomers, vinyl cyanide monomers, unsaturated carboxylic acid monomers, unsaturated polycarboxylic acid ester monomers, unsaturated carboxylic acid amide monomers, and unsaturated carboxylic acid monomers. Examples include units derived from one or more monomers selected from the group consisting of boxylic acid amides, methylolide-based monomers, polyfunctional aromatic hydrocarbon-based monomers, and polyfunctional allyl-based monomers.

Examples of fatty acid vinyl ester monomers include vinyl acetate and vinyl propionate. These fatty acid vinyl ester monomers may be used individually or in combination of two or more types.

Examples of halogenated olefin monomers include vinyl chloride, vinylidene chloride, tetrafluoroethylene, and vinylidene fluoride. These halogenated olefin monomers may be used individually or in combination of two or more types.

Examples of vinyl cyanide monomers include (meth)acrylonitrile.

Unsaturated carboxylic acid-based monomers include unsaturated carboxylic acids, salts or anhydrides thereof, for example, (meth)acrylic acid, crotonic acid, maleic acid, fumaric acid, ammonium or metal salts thereof, maleic anhydride, etc. I can hear it. These unsaturated carboxylic acid monomers may be used individually or in combination of two or more types.

Unsaturated polycarboxylic acid ester monomers include unsaturated dicarboxylic acid monoesters, their salts, and unsaturated dicarboxylic acid diesters, for example, monobutyl maleic acid, ammonium and metal salts thereof, and maleic acid. Dimethyl, etc. can be mentioned. These unsaturated polycarboxylic acid ester monomers may be used individually or in combination of two or more types.

Examples of unsaturated carboxylic acid amide monomers include (meth)acrylamide and diacetone (meth)acrylamide. These unsaturated carboxylic acid amide monomers may be used individually or in combination of two or more types.

Unsaturated carboxylic acid amides methylolide monomers include, for example, N-methylol acrylamide, N-methylol methacrylamide, methylolated diacetone acrylamide, and these monomers and alcohols having 1 to 8 carbon atoms. ether compounds, etc. are mentioned. These unsaturated carboxylic acid amides methylolide monomers may be used individually or in combination of two or more types.

Polyfunctional aromatic hydrocarbon monomers include, for example, m- or p-divinylbenzene, 1,3-, 1,8-, 1,4-, 1,5-, 2,3-, 2,6- or 2,7-divinylnaphthalene, 4,4'-, 4,3'-, 2,2'- or 2,4-divinylbiphenyl, 1,2-, 1,3-, 1,4- and one or more types selected from the group consisting of diisopropenylbenzene, 1,2-divinyl-3,4-dimethylbenzene, and derivatives thereof. These polyfunctional aromatic hydrocarbon monomers may be used individually or in combination of two or more types.

Examples of polyfunctional allyl-based monomers include diallyl phthalate and triallyl cyanurate. These polyfunctional allyl-based monomers may be used individually or in combination of two or more types.

<Composition of resin fine particles>

The amount ratio of each unit constituting the resin fine particles can be appropriately determined depending on the use or required characteristics of the resin fine particles, and is not particularly limited.

(a) The hydrolyzable silicon compound unit having a group that reacts with a hydrolyzable silyl group and a radically polymerizable unsaturated group is, for example, 0.1% by mass or more when the total of the units (a) to (d) is 100% by mass. , Preferably it is 0.5 mass % or more, for example, 10 mass % or less, Preferably it is 5 mass % or less.

(b) The monofunctional (meth)acrylic monomer unit is, for example, 10 mass% or more, preferably 15 mass% or more, when the total of units (a) to (d) is 100 mass%, for example For example, it is 90 mass% or less, preferably 85 mass% or less.

(c) The polyfunctional (meth)acrylic monomer unit is, for example, 3% by mass or more, preferably 5% by mass or more, when the total of units (a) to (d) is 100% by mass, for example For example, it is 50 mass % or less, preferably 40 mass % or less.

(d) The thiol-based compound unit is, for example, 0.1 mass% or more, preferably 0.3 mass% or more, when the total of units (a) to (d) is 100 mass%, for example, 5 mass%. % or less, preferably 3 mass% or less.

(e) The monofunctional vinyl monomer unit having an aromatic ring in the molecular structure is 0% by mass or more, for example, 5% by mass or more, when the total of units (a) to (e) is 100% by mass. , for example, 70% by mass or less, preferably 60% by mass or less.

(f) The reactive surfactant unit is 0% by mass or more, for example, 0.1% by mass or more, preferably 0.3% by mass, when the total of units (a) to (d) and (f) is 100% by mass. or more, for example, 5 mass% or less, preferably 3 mass% or less.

<Content of silicon element in resin fine particles measured by fluorescence X-ray analysis>

The resin fine particles of the present invention preferably have a silicon element content of 0.03 mass% or more and 1 mass% or less, and more preferably 0.05 mass% or more and 0.50 mass% or less, as measured by fluorescence X-ray analysis. Resin fine particles exhibiting these characteristics have very excellent heat resistance and do not affect haze or the like when formed into a film.

The silicon element in the resin fine particles in the present invention is a hydrolyzable silicon compound unit having a group that reacts with a hydrolyzable silyl group and a radically polymerizable unsaturated group, a monofunctional (meth)acrylic monomer unit, and a polyfunctional ( refers to the silicon element in “resin containing a meth)acrylic monomer unit and a thiol-based compound unit.” As a method for measuring the content of silicon element in resin fine particles by fluorescence X-ray analysis, for example, the method described in the Examples described later can be used.

<Heating loss ratio during heat treatment at 280°C for 1 hour under nitrogen atmosphere>

The resin fine particles of the present invention preferably have a heat loss ratio of 2.5% or less when heat-treated at 280°C for 1 hour in a nitrogen atmosphere. Resin fine particles exhibiting these characteristics have very excellent heat resistance.

As a method of measuring the rate of heat loss during heat treatment at 280°C for 1 hour under a nitrogen atmosphere, for example, the method described in the Examples described later can be used.

＜3% thermal decomposition temperature under nitrogen atmosphere＞

The resin fine particles of the present invention preferably have a 3% thermal decomposition temperature of 350°C or higher in a nitrogen atmosphere.

The 3% thermal decomposition temperature in a nitrogen atmosphere means that when the resin fine particles are heated from around room temperature, the temperature at which the mass of the resin fine particles decreases by 3% is 350°C or higher. Resin fine particles exhibiting these characteristics have very excellent heat resistance.

As a method for measuring the 3% thermal decomposition temperature in a nitrogen atmosphere, for example, the method described in the Examples described later can be used.

＜Volume average particle diameter＞

The volume average particle diameter (volume average primary particle diameter) of the resin fine particles of the present invention is not particularly limited and can be set appropriately depending on the purpose or use. For example, it is 0.05 ㎛ or more, preferably 0.07 ㎛ or more, more preferably 0.1 ㎛ or more, for example, 3 ㎛ or less, preferably 2 ㎛ or less, more preferably 1.5 ㎛ or less.

As a method of measuring the volume average particle diameter, for example, it can be measured using a laser scattering/diffraction type particle size distribution measuring device manufactured by Beckman Coulter. As a specific method for measuring the volume average particle diameter, for example, the method described in the Examples described later can be used.

＜Coefficient of variation of volume average particle diameter＞

The coefficient of variation of the volume average particle diameter of the resin fine particles of the present invention is not particularly limited and can be set appropriately depending on the purpose or use. For example, it is 25% or less, preferably 20% or less, and more preferably 17% or less.

The coefficient of variation of the volume average particle diameter of the resin fine particles is a value obtained from the following equation (1), and represents the distribution width of the data.

Coefficient of variation (%) = standard deviation × 100 / volume average primary particle diameter (1)

Here, the volume average particle diameter (volume average primary particle diameter) of the resin fine particles and its standard deviation can be measured using, for example, a laser scattering/diffraction type particle size distribution measuring device manufactured by Beckman Coulter.

The coefficient of variation of the volume average particle diameter can be obtained, for example, by the method described in the Examples described later.

＜Number of particles larger than 5㎛ out of 300,000＞

As for the resin fine particles of the present invention, it is preferable that the number of particles larger than 5 μm is 1 or less out of 300,000 in the following measurement range.

(measurement range)

Measurement range of particle diameter: 0.5㎛∼200㎛

Measurement range of particle circularity: 0.97∼1.00

A method of reducing the number of particles larger than 5 μm to one or less among 300,000 resin fine particles includes, for example, a method of classifying the resin fine particles. Classification methods include, but are not particularly limited to, a method of classifying by centrifugal force such as a centrifugal separator or air flow classifier, or a method of classifying by passing through a mesh or filter with a desired graduation size and absolute filtration accuracy.

In particular, by passing the polymer fine particle slurry obtained through the polymerization reaction through a filter with the desired absolute filtration accuracy to wet classify the resin fine particles, the number of particles larger than 5 μm among 300,000 resin fine particles can be adjusted.

As a method of measuring the number of particles larger than 5 μm out of 300,000, for example, the method described in the Examples described later can be used.

＜Resin fine particle assembly＞

The resin fine particle assembly of the present invention is formed by agglomerating a plurality of resin fine particles.

The resin fine particle granules can be obtained from the resin fine particle slurry obtained in the polymerization process by means such as spray drying, freeze granulation and drying. In spray drying, for example, a spray dryer (spray dryer) in which the inlet temperature of the resin fine particle slurry is 80°C or more and 220°C or less and the outlet temperature of the resin fine particle granule is 50°C or more and 100°C or less can be used. The obtained granules may have better handling properties than the resin fine particles themselves.

The resin fine particle granules can be classified as needed to keep the particle diameter constant. Classification can be done by known means.

The volume average particle diameter of the resin fine particle granules is not particularly limited. For example, it can be 5 to 200 μm, preferably 10 to 100 μm.

The obtained resin fine particle granulated body may be pulverized into resin fine particles. Disintegration methods include, for example, a dry disintegration method using mechanical grinders such as blade mills, super rotors, hammer mills, and airflow type grinders such as nano grinding mills (jet mills), or wet disintegration using bead mills and ball mills. There are ways to do this. The pulverized and dispersed resin fine particles may have good dispersibility in solvents.

＜Uses of resin fine particles＞

The resin fine particles of the present invention have excellent heat resistance and transparency, have a narrow particle size distribution, and have a small particle diameter. The resin fine particles of the present invention can be used for various purposes by taking advantage of these characteristics. For example, it is used as an anti-sticking agent (anti-blocking agent) for resin molded products (resin films), a modifier for various resin molded products, optical members such as light diffusers, anti-glare and low-reflection, additives for paints, and spacers between microscopic parts of various electronic devices. , it can be used as a pore-forming agent for various battery members, as core particles of conductive fine particles responsible for electrical connection, etc.

For example, the resin fine particles themselves can be mixed into a resin as an anti-sticking agent (anti-blocking agent) for a resin film to form a resin composition, thereby forming a resin molded body such as a film. In particular, the resin fine particles of the present invention have excellent heat resistance and transparency, have a narrow particle size distribution, and have a small particle diameter, so that even if the addition amount is increased when producing a resin composition for film formation, the effect on the haze of the film, etc. is suppressed. can do. In addition, the generation of resin residue due to heat load applied during resin compounding is suppressed, so there is little risk of yield deterioration.

By using these resin fine particles as an anti-sticking agent for resin films, especially as an anti-sticking agent for resin films for optical purposes, highly transparent optical members, for example, optical films such as anti-glare films and light diffusion films, light diffusers, etc. Stable production becomes possible.

[Method for producing resin fine particles]

The method for producing resin fine particles of the present invention includes at least a hydrolyzable silicon compound having a group that reacts with a hydrolyzable silyl group and a radically polymerizable unsaturated group, a monofunctional (meth)acrylic monomer, a polyfunctional (meth)acrylic monomer, and a thiol-based compound. There is no particular limitation as long as the method is such that resin fine particles are formed through this reaction. For example, in addition to the above compounds, if necessary, a polymerization initiator, liquid medium, surfactant, etc. are used to perform suspension polymerization, seed polymerization, swelling seed polymerization, seed emulsion polymerization, emulsion polymerization, soap-free polymerization, and mini-emulsion polymerization. , known polymerization methods such as microemulsion polymerization, solution polymerization, and dispersion polymerization.

Among them, emulsion polymerization, soap-free polymerization, swelling seed polymerization, seed emulsion polymerization, or dispersion polymerization are preferable because the desired resin fine particles with a constant particle size distribution can be obtained.

When selecting swelling seed polymerization or seed emulsion polymerization, seed particles serving as nuclei are created before obtaining the target resin fine particles. These seed particles are generally created by emulsion polymerization or soap-free polymerization.

Seed particles can generally be obtained by polymerizing a monomer mixture containing one or more of the above-mentioned monofunctional (meth)acrylic monomers or monofunctional vinyl monomers having an aromatic ring in the molecular structure. At this time, it is preferable to add a monomer having a functional group capable of condensing with a hydrolyzable silicon compound unit to the monomer mixture.

The monomer having a functional group capable of condensing with the hydrolyzable silicon compound unit is not particularly limited, but includes vinyl monomers having an epoxy group in the molecular chain, vinyl monomers having a hydroxyl group in the molecular chain, and the above-mentioned vinyl monomers. and hydrolyzable silicon compound units having a reactive group capable of copolymerization.

Examples of the vinyl monomer having an epoxy group in the molecular chain include one selected from the group consisting of glycidyl methacrylate, allyl glycidyl ether, allyl glycidyl phthalate, allyl glycidyl hexahydrophthalate, etc. The above can be mentioned.

Examples of vinyl monomers having a hydroxyl group in the molecular chain include 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 2-hydroxylethyl acrylate, and 2-hydroxypropyl acrylate. , 2-hydroxybutyl methacrylate, 2-hydroxybutyl acrylate, 2-hydroxy-3-phenoxypropyl acrylate, glycerin monoallyl ether, neopentyl glycol monoallyl ether, о-allylphenol, glycerin mono. Methacrylate, polyethylene glycol monomethacrylate, polypropylene glycol monomethacrylate, polyethylene glycol propylene glycol monomethacrylate, polyethylene glycol tetramethylene glycol monomethacrylate, propylene glycol polybutylene glycol monomethacrylate, polyethylene One or more types selected from the group consisting of glycol monoacrylate, polypropylene glycol monoacrylate, etc. can be mentioned.

As a monomer having a functional group capable of condensation with these hydrolyzable silicon compound units, one type may be used individually, or two or more types may be used in mixture.

＜Polymerization initiator＞

As a polymerization initiator for producing the resin fine particles of the present invention, any known polymerization initiator can be used without particular limitation. In the case of emulsion polymerization or soap-free polymerization, it is preferable to use a thermally decomposable, water-soluble polymerization initiator, and in the case of seed polymerization or suspension polymerization, it is preferable to use a thermally decomposable, oil-soluble polymerization initiator.

As a polymerization initiator for producing the resin fine particles of the present invention, it is preferable to use a radical polymerization initiator, especially a thermal polymerization initiator.

Among radical polymerization initiators, water-soluble polymerization initiators are selected from the group consisting of persulfates (e.g., ammonium persulfate, potassium persulfate, sodium persulfate, etc.), hydrogen peroxide, organic peroxides, nitrile-azo compounds, etc. One or more types may be mentioned.

Among radical polymerization initiators, oil-soluble polymerization initiators include, for example, cumene hydroperoxide, di-tert-butyl peroxide, dicumyl peroxide, benzoyl peroxide, lauroyl peroxide, and dimethylbis(tert-butylperoxy)hexane. , dimethylbis(tert-butylperoxy)hexyne-3, bis(tert-butylperoxyisopropyl)benzene, bis(tert-butylperoxy)trimethylcyclohexane, butyl-bis(tert-butylperoxy)valerate. , organic peroxides such as tert-butyl 2-ethylhexane peroxyate, dibenzoyl peroxide, paramenthan hydroperoxide, and tert-butyl peroxybenzoate; 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(2-isopropylbutyronitrile), 2,2'- Azobis(2,3-dimethylbutyronitrile), 2,2'-Azobis(2,4-dimethylbutyronitrile), 2,2'-Azobis(2-methylcapronitrile), 2,2' -Azobis(2,3,3-trimethylbutyronitrile), 2,2'-azobis(2,4,4-trimethylvaleronitrile), 2,2'-azobis(2,4-dimethylvalerone) ronitrile), 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis(4-ethoxy-2,4-dimethylvaleronitrile), 2,2'-azobis(4-n-butoxy-2,4-dimethylvaleronitrile), 1,1'-azobis(cyclohexane-1-carbonitrile), 2-(carbamoylazo) One or more types selected from the group consisting of nitrile-azo compounds such as isobutyronitrile and 4,4'-azobis(4-cyanopentanoic acid).

In addition, the polymerization initiator of the persulfate and organic peroxide, sodium sulfoxylate formaldehyde, sodium hydrogen sulfite, ammonium bisulfite, sodium thiosulfate, ammonium thiosulfate, hydrogen peroxide, sodium hydroxymethanesulfinate, L-ascorbic acid and the like. A redox polymerization initiator combining a reducing agent such as salt, cuprous salt, or ferrous salt may be used.

Among these, 2,2'-azobisisobutyronitrile, 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis(2,4- dimethylvaleronitrile), 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 1,1'-azobis(cyclohexane-1-carbonitrile) , 4,4'-azobis(4-cyanopentanoic acid), cumene hydroperoxide, di-tert-butyl peroxide, dicumyl peroxide, benzoyl peroxide, and lauroyl peroxide. This is desirable.

These polymerization initiators may be used individually by 1 type, or may be used in mixture of 2 or more types.

The amount of polymerization initiator used can be appropriately determined depending on its type and is not particularly limited. For example, 0.1 parts by mass or more, preferably 0.3 parts by mass or more, for example, 5 parts by mass or less, preferably 3 parts by mass or less, relative to 100 parts by mass of all monomers used during polymerization. It is within range.

＜Surfactant＞

The surfactant that may be used in the method for producing resin fine particles of the present invention is not particularly limited, and any known surfactant can be used.

The type of surfactant is appropriately selected and the amount used is appropriately adjusted in consideration of the particle diameter of the obtained resin fine particles and the dispersion stability of the monomer during polymerization.

In the method for producing resin fine particles of the present invention, an anionic surfactant, for example, an anionic non-reactive surfactant or an anionic reactive surfactant can be used. These anionic surfactants may be used individually, or two or more types may be mixed.

Examples of anionic non-reactive surfactants include sodium oleate; Fatty acid soaps such as castor oil potassium soap; Alkyl sulfate ester salts such as sodium lauryl sulfate and ammonium lauryl sulfate; Alkylbenzenesulfonate salts such as sodium dodecylbenzenesulfonate; Alkylnaphthalenesulfonate; alkanesulfonate; dialkyl sulfosuccinate; Alkyl phosphate ester salt; Naphthalenesulfonic acid formalin condensate; Polyoxyethylene alkyl phenyl ether sulfate ester salt; polyoxyethylene sulfonated phenyl ether phosphoric acid; One or more types selected from the group consisting of polyoxyethylene alkyl sulfate ester salts, etc. can be mentioned.

Anionic reactive surfactants include, for example, JS-20 and RS-3000 of Eleminol (registered trademark) manufactured by Sanyo Kasei Corporation, and KH-10 and KH of Aqualon (registered trademark) manufactured by Daiichi Kogyo Seiyaku Corporation. -1025, KH-05, HS-10, HS-1025, BC-0515, BC-10, BC-1025, BC-20, BC-2020, AR-1025, AR-2025, manufactured by Nippon New Kazai. Tox (registered trademark) MS-60, S-120, S-180A, S-180, PD-104 of Latte Water (registered trademark) manufactured by Kao Corporation, and SR of Adecaria Soap (registered trademark) manufactured by ADEKA Corporation. One or more types selected from the group consisting of -1025, SE-10N, etc. can be mentioned. Among them, having an oxyalkylene chain in the molecular chain is preferable from the viewpoint of improving the dispersibility of the particles.

In the method for producing resin fine particles of the present invention, a nonionic surfactant, for example, a nonionic nonreactive surfactant or a nonionic reactive surfactant, can be used. These nonionic surfactants may be used individually, or two or more types may be mixed.

Nonionic non-reactive surfactants include, for example, polyoxyalkylene branched decyl ether, polyoxyethylene tridecyl ether, polyoxyalkylene alkyl ether, polyoxyalkylene tridecyl ether, polyoxyethylene isodecyl ether, Polyoxyalkylene lauryl ether, polyether polyol, polyoxyethylene styrenated phenyl ether, polyoxyethylene naphthyl ether, polyoxyethylene phenyl ether, polyoxyethylene polyoxypropylene glycol, polyoxyethylene lauryl ether, polyoxyethylene Oleyl cetyl ether, polyoxyethylene glyceryl isostearate, polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene fatty acid ester, sorbitan fatty acid ester, polyoxysorbitan fatty acid ester, polyoxyethylene alkylamine. , glycerol fatty acid ester, oxyethylene-oxypropylene block polymer, etc. can be mentioned.

Nonionic reactive surfactants include, for example, an alkyl ether type (commercially available products include, for example, ADEKA, Adecaria Soap ER-10, ER-20, ER-30, ER-40, etc.; KAOS) manufacturing, latte water PD-420, PD-430, PD-450, etc.); Alkylphenyl ether type or alkylphenyl ester type (commercially available products include, for example, Aquaron RN-10, RN-20, RN-30, RN-50, AN-10, AN-20, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) AN-30, AN-5065, etc.; Adecaria Soap NE-10, NE-20, NE-30, NE-40, etc. manufactured by ADEKA); One or more types selected from the group consisting of (meth)acrylate sulfate esters (commercially available products, for example, RMA-564, RMA-568, RMA-1114, manufactured by Nippon New Kazai Co., Ltd., etc.). Among them, having an oxyalkylene chain in the molecular chain is preferable from the viewpoint of dispersion stability of the particles.

In the method for producing resin fine particles of the present invention, a cationic surfactant or an amphoteric surfactant can be used. These cationic surfactants and amphoteric surfactants may be used individually or in combination of two or more types.

Cationic surfactants include, for example, alkylamine salts such as laurylamine acetate and stearylamine acetate; One or more types selected from the group consisting of quaternary ammonium salts such as lauryl trimethyl ammonium chloride, etc. can be mentioned.

Examples of the amphoteric surfactant include at least one selected from the group consisting of lauryldimethylamine oxide, laurylaminobetaine acetate, etc.

In the present invention, a reactive surfactant, in particular, one or more types selected from the group consisting of anionic reactive surfactants and nonionic reactive surfactants can be used, whereby the resin fine particles (f) reactive surfactant units will include.

The amount of surfactant used can be appropriately determined depending on its type and is not particularly limited. For example, 0.1 parts by mass or more, preferably 0.3 parts by mass or more, for example, 5 parts by mass or less, preferably 3 parts by mass or less, relative to 100 parts by mass of all monomers used during polymerization. It is within range.

＜Liquid medium＞

The liquid medium used in the method for producing resin fine particles of the present invention is not particularly limited. For example, any of water, organic solvents, and mixtures thereof can be used. In the present invention, an aqueous medium is preferable, and for example, water, lower alcohols with 5 or less carbon atoms such as methyl alcohol and ethyl alcohol, and mixtures of water and lower alcohols can be used.

<Preferred manufacturing method of resin fine particles>

In the method for producing resin fine particles of the present invention, in particular, in the first step, a monomer component containing a monofunctional (meth)acrylic monomer is emulsion polymerized or soap-free polymerized to create seed particles, and in the second step, a vinyl monomer is added. A monomer mixture containing a hydrolyzable silicon compound unit having a reactive group capable of copolymerization, a monofunctional (meth)acrylic monomer unit, a polyfunctional (meth)acrylic monomer unit, and a thiol-based compound unit is absorbed into the seed particles. It is preferable to include a polymerization method.

In the method for producing resin fine particles of the present invention, it is preferable to further include a monofunctional vinyl monomer unit having an aromatic ring in the molecular structure in the monomer mixture in the second step.

In the method for producing resin fine particles of the present invention, it is preferable to classify the resin fine particles through a filter with a desired absolute filtration accuracy, for example, an absolute filtration accuracy of 5 μm or less.

In addition, in the method for producing resin fine particles of the present invention, the resin fine particles may be granulated and dried to form a resin fine particle granulated body.

Example

Hereinafter, the present invention will be described in more detail through production examples, examples, and comparative examples. Meanwhile, the present invention is not limited to these. In each example, “part” represents “part by mass” and “%” represents “% by mass.”

[measurement method]

“Content of silicon element in resin fine particles measured by fluorescence Measurements of “particle diameter”, “coefficient of variation of volume average particle diameter”, and “number of particles 5 μm or larger in 300,000 resin fine particles” were performed as follows.

<Content of silicon element in resin fine particles measured by fluorescence X-ray>

The content of the silicon element in the resin fine particles was determined by measuring the peak height of the silicon element using fluorescence X-ray spectroscopy, and determining the element content of the silicon element using the order analysis method (FP bulk method). Specifically, the intensity of Si-Kα was measured using a fluorescence The content of elements was measured. First, a conductive carbon double-sided tape (manufactured by Nissin EM Company) was attached to a carbon sample stand (manufactured by Nissin EM Company). 20 mg of the sample (resin fine particles produced in each Example and Comparative Example) was weighed on the affixed conductive carbon double-sided tape, and the sample was adjusted so as not to spread beyond 10 mmϕ. After that, it was covered with a PP film (polypropylene film) and set in the 10 mm phi sample case attached to the device to serve as a measurement sample.

Next, the peak height of the silicon element was measured under the following conditions, and the element content of the silicon element was determined according to the order analysis method.

＜Device conditions＞

· Device: ZSX Primus IV

· X-ray sphere target: Rh

· Analysis method: Order analysis method (FP bulk method)

· Measurement diameter: 10mm

· Spin: Yes

· Atmosphere: Vacuum

· Sample type: Metal

· Balance ingredient: CHO

· Sample protective film correction: Yes (PP film)

· Smoothing: 11 points

· Flux composition, dilution rate, impurity removal: None

＜Qualitative element conditions＞

· Si-Kα

· District: Rh (30kV-100mA)

· 1st filter: OUT

· Attenuator: 1/1

· Slit: Std.

· Spectral crystal: Ge

· 2θ: 110.820deg (Measurement range: 107∼114deg)

· Detector: PC

· PHA L.L.: 150 U.L.: 300

· Step: 0.05deg

· Time: 0.4sec

<Heating loss ratio during heat treatment at 280°C for 1 hour under nitrogen atmosphere>

The “heating loss ratio during heat treatment at 280° C. for 1 hour in a nitrogen atmosphere” of the resin fine particles was measured using a differential thermal thermogravimetric simultaneous measurement device (TG/DTA6200, manufactured by SI Nanotechnology Co., Ltd.). The sample production method and measurement conditions are as follows.

(How to make samples)

The bottom of a platinum measuring container was filled with about 15 mg of resin fine particles (measurement sample) so that no gaps were formed, and a sample was produced.

(Measuring conditions)

The nitrogen gas flow rate was set at 230 mL/min, and alumina was used as the reference material. Raise the temperature from 40°C to 100°C at 10°C/min, hold at 100°C for 10 minutes, raise the temperature from 100°C to 280°C at 10°C/min, and hold at 280°C for 1 hour to obtain a TG/DTA curve. From the obtained TG/DTA curve, the heating loss ratio at the end of the measurement was determined using the analysis software included with the device, and this was set as the “heating loss ratio during heat treatment at 280°C for 1 hour under a nitrogen atmosphere.”

＜3% thermal decomposition temperature under nitrogen atmosphere＞

The “3% thermal decomposition temperature in a nitrogen atmosphere” of the resin fine particles was measured using a differential heat thermogravimetric simultaneous measuring device (TG/DTA6200, manufactured by SI Nanotechnology Co., Ltd.). The sample production method and measurement conditions are as follows.

(How to make samples)

The bottom of a platinum measuring container was filled with about 15 mg of resin fine particles (measurement sample) so that no gaps were formed, and a sample was produced.

(Measuring conditions)

The nitrogen gas flow rate was set at 230 mL/min, and alumina was used as the reference material. The temperature is raised from 300°C to 500°C at 10°C/min to obtain a TG/DTA curve. From the obtained TG/DTA curve, the temperature at which the mass of the sample decreased by 3% from the start of measurement was determined using the analysis software included with the device, and this was set as the “3% thermal decomposition temperature in a nitrogen atmosphere.”

＜Volume average particle diameter＞

0.1 g of resin fine particle aqueous dispersion (solid content 20%) and 20 mL of 2% by mass anionic surfactant solution were added to the test tube. After that, it was added and dispersed for 5 minutes using a test tube mixer ("Test Tube Mixer TRIO HM-1N" manufactured by Azone Corporation) and an ultrasonic cleaner ("ULTRASONIC CLEANER VS-150" manufactured by Azone Corporation) to obtain a dispersion. While irradiating the obtained dispersion with ultrasonic waves, the volume-based particle size distribution of the resin fine particles and its standard deviation were obtained using a laser diffraction scattering type particle size distribution measuring device (“LS230” manufactured by Beckman Coulter). The arithmetic mean of the volume-based particle size distribution was taken as the volume average particle diameter of the resin fine particles.

The measurement conditions of the laser diffraction scattering type particle size distribution measuring device are as follows.

Medium = water

Refractive index of medium = 1.333

Refractive index of solid = Refractive index of resin fine particles

PIDS relative concentration: 40 to 55%

The optical model at the time of measurement was adjusted to the refractive index of the produced resin fine particles. When one type of monomer was used in the production of resin fine particles, the refractive index of the homopolymer of that monomer was used as the refractive index of the resin fine particles. When multiple types of monomers were used in the production of resin fine particles, the average value obtained by weighting the refractive index of the homopolymer of each monomer by the amount of each monomer used was used as the refractive index of the resin fine particles.

＜Coefficient of variation of volume average particle diameter＞

The coefficient of variation (CV value) of the volume average particle diameter of the resin fine particles was calculated according to the following equation.

Coefficient of variation of the volume average particle diameter of resin fine particles = [(standard deviation of particle size distribution based on the volume of resin fine particles) / (volume average particle diameter of resin fine particles)] × 100

＜Number of particles 5㎛ or larger out of 300,000 resin particles＞

An aqueous surfactant solution was prepared by adding 0.01 part of surfactant (dodecylbenzenesulfonate) to 4.94 parts of ion-exchanged water. 0.06 parts of resin fine particles were added to the aqueous surfactant solution, and the mixture was added for 10 minutes using a disperser (ultrasonic cleaner (VS-150, manufactured by Belvo Clear)), and the resin fine particles were dispersed in the aqueous surfactant solution to obtain an aqueous dispersion of resin fine particles.

The obtained resin fine particle aqueous dispersion was subjected to a flow-type particle image analysis device (FPIA-3000S, manufactured by Sysmex; equipped with a standard objective lens (10x); using a particle sheath (PSE-900A, manufactured by Sysmex) as the sheath liquid). It was introduced and measured under the following measurement conditions.

Measurement mode: HPF measurement mode

Measurement range of particle diameter: 0.5∼200㎛

Measurement range of particle circularity: 0.2 to 1.0

Measured number of particles: 100,000

In the measurement, before starting the measurement, a suspension of the standard polymer particle group (e.g., 5200A (standard polystyrene particle group diluted with ion-exchanged water) manufactured by Thermo Fisher Scientific) is used and the flow type particle image analyzer is used. performed automatic focus adjustment.

The circularity is a value obtained by dividing the circumferential length calculated from the diameter of a perfect circle having the same projected area as the image obtained by capturing the resin fine particles by the peripheral length of the image captured by the resin fine particles.

From the particle diameters of the resin fine particles obtained by measurement, the number of resin fine particles having a volume average particle diameter of 5 μm or more was counted.

These operations were performed three times, and the sum of the number counts of resin fine particles having a volume average particle diameter of 5 μm or more was determined. This sum was taken as “the number of particles 5 μm or larger out of 300,000 resin fine particles.”

[Manufacturing example]

＜Manufacturing Example 1＞

In a polymerization reactor equipped with a stirring device, thermometer, and cooling mechanism, each component was mixed in a ratio of 270 parts of ion-exchanged water and 0.84 parts of sodium styrenesulfonate to prepare an aqueous phase.

In another container, the monomer mixture obtained by mixing the monomer components in a ratio of 114 parts of methyl methacrylate, 6 parts of 2-hydroxyethyl methacrylate, and 2.4 parts of 1-octanethiol was added to the water phase in the polymerizer. . After purging the polymerization reactor with nitrogen for 5 minutes, the temperature was raised to 80°C, and when 80°C was reached, a solution of 0.6 parts of potassium persulfate dissolved in 10 parts of ion-exchanged water was added. After that, the polymerization reactor was purged with nitrogen again for 5 minutes and then stirred at 80°C for 5 hours to cause an emulsion polymerization reaction. Next, a slurry containing seed particle A was produced by raising the temperature to 100°C, maintaining it for 3 hours, and then cooling. The volume average particle diameter of seed particle A was 176 nm.

＜Manufacture Example 2＞

As the monomer mixture, Preparation Example 1 and In the same manner, a slurry containing seed particle B was obtained. The volume average particle diameter of seed particle B was 177 nm.

＜Manufacture Example 3＞

A slurry containing seed particle C was obtained in the same manner as in Production Example 1, except that a monomer mixture obtained by mixing monomer components in a ratio of 120 parts of methyl methacrylate and 2.4 parts of 1-octanethiol was used as the monomer mixture. The volume average particle diameter of the seed particle C was 175 nm.

[Examples/Comparative Examples]

<Example 1>

In a polymerization vessel equipped with a stirring device, a thermometer, and a cooling mechanism, 280 parts of ion-exchanged water, 2.8 parts of a 20% solution of sodium dodecylbenzenesulfonate (Neogen S-20D, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), and polyoxyethylene styrene. Each component was mixed in a ratio of 0.7 parts of phenyl ether (Neugen EA-167, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) and 0.014 parts of sodium nitrite to prepare an aqueous phase.

In another container, 35.00 parts of butyl acrylate, 21.00 parts of styrene, 14.00 parts of ethylene glycol dimethacrylate, 0.35 parts of pentaerythritol tetrakistioglycolate, 1.33 parts of 3-methacryloxypropyltriethoxysilane, 2,2' - A monomer composition was prepared by mixing the monomer components in a ratio of 0.35 parts of azobisisobutyronitrile and 0.18 parts of benzoyl peroxide (pure content 74.2%) to form an oil phase.

The oil phase was added to the water phase in the polymerization reactor and stirred at 8000 rpm for 10 minutes using a TK homomixer (manufactured by Primix) to obtain a monomer mixture. To this monomer mixture, 33.3 parts of seed particles A produced in Production Example 1 were added and stirred for 3 hours to swell. Afterwards, nitrogen purge was performed for 5 minutes, the temperature was raised to 65°C, and polymerization was carried out by stirring at 65°C for 6 hours. After adding 0.021 part of sulfamic acid, the temperature was raised to 100°C, maintained for 3 hours, and then cooled to prepare a slurry containing resin fine particles.

The obtained resin fine particle-containing slurry was passed through a 500 mesh SUS net and then passed through a filter (KDGF-030, manufactured by Asahi Kasei Co., Ltd.) with an absolute filtration accuracy of 3 μm, thereby performing wet classification of the resin fine particle slurry. got it

The classified resin fine particle slurry was spray-dried using an atomizer take-up spray dryer (TRS-3WK, manufactured by Sakamoto Kijutsu Kenkyusho Co., Ltd.) under the following spray drying conditions to obtain resin fine particles.

(Spray drying conditions)

Feed rate of slurry containing resin fine particles: 25 mL/min

Atomizer rotation speed: 12000rpm

Air volume: 2m ³ /min

Inlet temperature (temperature of the inlet where the slurry containing sprayed resin particles is input): 150℃

Outlet temperature (powder outlet temperature where resin particles are discharged): 70℃

The obtained resin fine particles exhibited the following characteristics.

Content of silicon element in resin fine particles measured by fluorescence X-ray analysis: 0.17 mass%

Heating loss ratio when heat treated at 280°C for 1 hour under nitrogen atmosphere: 1.8%

3% pyrolysis temperature under nitrogen atmosphere: 356°C

Volume average particle diameter: 350 nm

Coefficient of variation of volume average particle diameter: 14.5%

Number of particles larger than 5㎛ out of 300,000 resin particles: 0

<Examples 2 to 5>

Resin fine particles were obtained in the same manner as in Example 1, except that the monomer composition shown in Table 1 was used as the monomer composition. The properties of the obtained resin fine particles are shown in Table 1.

<Example 6>

As a surfactant component, 2.8 parts of a 20% solution of sodium dodecylbenzenesulfonate (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Neogen S-20D), polyoxyethylene styrenated phenyl ether (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Neogen EA) -167) Resin fine particles were obtained in the same manner as in Example 4, except that instead of 0.7 parts, 5 parts Aqualon KH-1025 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., main ingredient 25%) was used. The properties of the obtained resin fine particles are shown in Table 1.

<Comparative Example 1>

A slurry containing resin fine particles was obtained in the same manner as in Example 1, except that a monomer composition of the composition shown in Table 1 was used as the monomer composition. The obtained slurry containing resin fine particles was passed through a 500 mesh SUS net, and then spray dried in the same manner as in Example 1 to obtain resin fine particles. The properties of the obtained resin fine particles are shown in Table 1.

<Comparative Examples 2 to 3>

Resin fine particles were obtained in the same manner as in Comparative Example 1, except that the monomer composition shown in Table 1 was used as the monomer composition. The properties of the obtained resin fine particles are shown in Table 1.

The description in the monomer composition column in the table is as follows.

BA: Butyl acrylate

St: Styrene

EGDMA: ethylene glycol dimethacrylate

PETG: pentaerythritol tetrakistioglycolate

MPTESi: 3-methacryloxypropyltriethoxysilane

MPTM Si: 3-methacryloxypropyltrimethoxysilane

KH-1025: Reactive surfactant (Aquaron KH-1025)

The present invention can be implemented in various other forms without departing from its spirit or main features. For this reason, the above-described embodiments are merely examples in all respects and should not be construed as limiting. The scope of the present invention is indicated by the claims, and is not restricted at all by the text of the specification. In addition, all modifications and changes falling within the equivalent scope of the claims are within the scope of the present invention.

Claims (17)

(a) a hydrolyzable silicon compound unit having a hydrolyzable silyl group and a group that reacts with a radically polymerizable unsaturated group, (b) a monofunctional (meth)acrylic monomer unit, (c) a polyfunctional (meth)acrylic monomer unit, and (d) ) Resin fine particles containing a thiol-based compound unit. According to claim 1,
Resin fine particles in which the content of silicon element in the resin fine particles is 0.03 mass% or more and 1 mass% or less as measured by fluorescence X-ray analysis. The method of claim 1 or 2,
(e) Resin fine particles further comprising a monofunctional vinyl monomer unit having an aromatic ring in the molecular structure. The method of claim 1 or 2,
Resin fine particles in which the (b) monofunctional (meth)acrylic monomer unit includes a (meth)acrylic acid alkyl ester unit having an alkyl group of 2 or more carbon atoms. The method of claim 1 or 2,
Resin fine particles having a heat loss ratio of 2.5% or less when heat treated at 280°C for 1 hour in a nitrogen atmosphere. The method of claim 1 or 2,
Resin fine particles having a 3% thermal decomposition temperature of 350°C or higher in a nitrogen atmosphere. The method of claim 1 or 2,
Resin fine particles having a volume average particle diameter of 0.05 μm or more and 3 μm or less. The method of claim 1 or 2,
Resin fine particles having a coefficient of variation of the volume average particle diameter of 25% or less. The method of claim 1 or 2,
The following measurement ranges;
(measurement range)
Measurement range of particle diameter: 0.5㎛∼200㎛,
Measurement range of particle circularity: 0.97∼1.00
Resin fine particles in which the number of particles 5 μm or larger is 1 or less among 300,000 resin fine particles. The method of claim 1 or 2,
(f) Resin microparticles further comprising a reactive surfactant unit. A resin fine particle assembly comprised by agglomerating a plurality of the resin fine particles of claim 1 or 2. The method of claim 1 or 2,
Resin fine particles used as an anti-sticking agent for resin films. According to claim 12,
Resin fine particles, wherein the resin film is a resin film for optical applications. A first step of creating seed particles by emulsion polymerization or soap-free polymerization of a monomer component containing a monofunctional (meth)acrylic monomer, and
A mixture containing a hydrolyzable silicon compound having a group that reacts with a hydrolyzable silyl group and a radically polymerizable unsaturated group, a monofunctional (meth)acrylic monomer, a polyfunctional (meth)acrylic monomer, and a thiol-based compound is absorbed into the seed particles. A method for producing resin fine particles, comprising a second step of polymerization. According to claim 14,
A method for producing resin fine particles, wherein the mixture used in the second step further contains a monofunctional vinyl monomer having an aromatic ring in its molecular structure. The method of claim 14 or 15,
A method for producing resin fine particles, comprising a step of classifying the obtained resin fine particles through a filter with an absolute filtration accuracy of 5 μm or less. A method for producing resin fine particles, comprising granulating and drying the resin fine particles obtained by the method for producing resin fine particles according to claim 14 or 15.