JP6014244B2 - Dispersion of crosslinked fine particles and method for producing the same - Google Patents

Description

  The present invention relates to a dispersion of crosslinked fine particles and a method for producing the same.

  Conventionally, (meth) acrylic crosslinked fine particles obtained by polymerizing a monomer composition containing a (meth) acrylic monomer and a crosslinkable monomer copolymerizable with the monomer composition. Cross-linked fine particle dispersions are known which are dispersed in a dispersion medium. As a method for producing the crosslinked fine particle dispersion, a method for obtaining a (meth) acrylic crosslinked fine particle dispersion by emulsion polymerization of the monomer composition and the crosslinkable monomer is known. (For example, refer to Patent Document 1).

  The crosslinked fine particle dispersion as described above is used for the purpose of improving physical properties such as light diffusibility, blocking resistance and slipperiness and imparting further properties to resin films and resin molded products. In addition, the crosslinked fine particles in the crosslinked fine particle dispersion are used as spacers between minute parts of electronic devices and as base particles of conductive fine particles responsible for electrical connection. The cross-linked fine particles used for such applications are required to have a smaller diameter as the resin film becomes thinner and electronic devices become smaller.

JP-A-1-182313

  By the way, in the case of producing a crosslinked fine particle dispersion by the conventional production method described above, a polymerizable monomer having a small amount of a hydrophilic functional group as a monomer composition in order to suppress aggregation of particles during the polymerization reaction. It is desirable to use ingredients. However, when a crosslinked fine particle dispersion is produced from a monomer composition essentially comprising a (meth) acrylic acid ester monomer component, a crosslinkable monomer component and a polymerizable monomer component having a hydrophilic functional group In some cases, the resulting dispersion may have poor dispersibility (storage stability). Specifically, when the obtained crosslinked fine particle dispersion was stored, the crosslinked fine particles aggregated and settled, resulting in poor storage stability. Such a problem of deterioration in dispersibility becomes particularly remarkable when the storage period is long or when the storage is performed at a high temperature. In addition, as the particle size of the crosslinked fine particles in the crosslinked fine particle dispersion becomes smaller, the particles in the dispersion tend to aggregate and the dispersibility tends to deteriorate.

  The present invention has been made in view of the above problems, and provides a crosslinked fine particle dispersion having excellent storage stability without aggregation of crosslinked fine particles even when stored at high temperatures for a long period of time. With the goal.

  The crosslinked fine particle dispersion of the present invention contains crosslinked fine particles, a surfactant and a basic substance, and the crosslinked fine particles have a (meth) acrylate monomer component, a crosslinkable monomer component and a hydrophilic functional group. It is formed from a monomer composition containing a polymerizable monomer component, and the content of the crosslinkable monomer component is 10 to 50 parts by mass with respect to 100 parts by mass of the monomer composition. The content of the polymerizable monomer component having a hydrophilic functional group is 0.1 to 20 parts by mass with respect to 100 parts by mass of the monomer composition.

  The content of the basic substance is preferably 20 to 500 mol with respect to 100 mol of the polymerizable monomer component having the hydrophilic functional group. The average particle diameter of the crosslinked fine particles is preferably in the range of 0.005 to 0.2 μm.

  The method for producing a crosslinked fine particle dispersion according to the present invention comprises a monomer composition comprising a (meth) acrylic acid ester monomer component, a crosslinkable monomer component, and a polymerizable monomer component having a hydrophilic functional group. It includes a polymerization step of emulsion-polymerizing a product in the presence of a surfactant and an addition step of adding a basic substance.

  Moreover, the crosslinked fine particle dispersion according to the present invention can be added to a resin emulsion and used as an aqueous paint, for example, and the aqueous paint according to the present invention contains the crosslinked fine particle dispersion of the present invention and a resin emulsion. .

The crosslinked fine particle dispersion of the present invention includes crosslinked fine particles obtained from a monomer composition containing a polymerizable monomer component having a hydrophilic functional group, and the polymerizable monomer component having the hydrophilic functional group contains Although it can suppress aggregation of particles during the polymerization reaction, it also contains a basic substance together with a surfactant, so even when stored at high temperatures for a long period of time, the crosslinked fine particles are stored without agglomeration. Excellent stability.
In addition, the crosslinked fine particle dispersion is once included in the dispersion depending on the application, for example, when used as an additive to various resins such as oil paints, inks, epoxy resins, acrylic resins, urethane resins, polyester resins, polystyrene resins, etc. In some cases, the crosslinked fine particles of the present invention are excellent in redispersibility in such a case.

1. Crosslinked fine particle dispersion The crosslinked fine particle dispersion of the present invention comprises crosslinked fine particles, a surfactant, and a basic substance.

1.1. Crosslinked fine particles The crosslinked fine particles constituting the crosslinked fine particle dispersion of the present invention essentially comprise a (meth) acrylate monomer component, a crosslinkable monomer component, and a polymerizable monomer component having a hydrophilic functional group. It is formed from a monomer composition. The crosslinked fine particles may be only one kind or two or more kinds.

  In the present invention, the polymerizable monomer having a hydrophilic functional group (hydrophilic functional group-containing polymerizable monomer) has one polymerizable double bond in one molecule and has a hydrophilic functional group. Means a monomer having The polymerizable monomer component having a hydrophilic functional group is composed of one or more of the hydrophilic functional group-containing polymerizable monomers.

  The hydrophilic functional group is not particularly limited, and examples thereof include a carboxylic acid group, a sulfonic acid group, a hydroxyl group, a phenol group, and an alkylene oxide group. Moreover, when a functional group is acidic, the salt is also mentioned as a hydrophilic functional group. Among these, a carboxylic acid group-containing polymerizable monomer, a sulfonic acid group-containing polymerizable monomer, a hydroxyl group-containing polymerizable monomer, and the like are preferable.

  Specific examples of the carboxylic acid group-containing polymerizable monomer include (meth) acrylic acid, crotonic acid, itaconic acid, fumaric acid, maleic acid, monomethyl fumarate, monoethyl fumarate, monomethyl malate, monoethyl malate And unsaturated carboxylic acids such as Examples of the derivatives include salts of unsaturated carboxylic acids. Among these, (meth) acrylic acid or a derivative thereof is particularly preferable.

  Specific examples of the sulfonic acid group-containing polymerizable monomer include vinyl sulfonic acid, styrene sulfonic acid, allyl sulfonic acid, allyl alkyl ether sulfonic acid, sulfoethyl (meth) acrylate, sulfopropyl (meth) acrylate, sulfobutyl (meth). An acrylate etc. are mentioned. In addition, a salt of a sulfonic acid group-containing polymerizable monomer is also one preferred form.

  Specific examples of the hydroxyl group-containing polymerizable monomer include hydroxymethyl (meth) acrylate, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, hydroxypentyl (meth) acrylate, and the like. Examples include hydroxyalkyl (meth) acrylate.

  Content of the said hydrophilic functional group containing polymerizable monomer component is 0.1-20 mass parts with respect to 100 mass parts of said monomer compositions. The lower limit is preferably 0.2 parts by mass or more, and more preferably 0.3 parts by mass or more. The upper limit is preferably 15 parts by mass or less, and more preferably 10 parts by mass or less. When the content of the hydrophilic functional group-containing polymerizable monomer is within the above range, aggregation of particles during the polymerization reaction during production of the crosslinked fine particles can be suppressed and stable polymerization can be performed.

  In the present invention, the crosslinkable monomer means a monomer having two or more polymerizable double bonds in one molecule. The crosslinkable monomer component is composed of one or more of the crosslinkable monomers.

  Specific examples of the crosslinkable monomer include divinylbenzene; ethylene glycol di (meth) acrylate, hexanediol di (meth) acrylate, pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, Examples include polyfunctional (meth) acrylates such as tetramethylolmethanetetra (meth) acrylate; diallyl phthalate, triallyl cyanurate, and the like. Of these, divinylbenzene is most preferred.

  Content of a crosslinkable monomer component is 10-50 mass parts with respect to 100 mass parts of said monomer compositions. The lower limit is preferably 15 parts by mass or more, and more preferably 20 parts by mass or more. When the content of the crosslinkable monomer component is less than 10 parts by mass with respect to 100 parts by mass of the monomer composition, the crosslinked fine particles having the average particle diameter and the particle size distribution to be obtained cannot be obtained. When the density becomes insufficient and the crosslinked fine particles are used, the crosslinked fine particles may be deformed during heating and drying. On the other hand, when the content of the crosslinkable monomer component is more than 50 parts by mass with respect to 100 parts by mass of the monomer composition, the polymerizability is deteriorated and the crosslinked fine particles are easily aggregated.

  In the present invention, the (meth) acrylic acid ester monomer means an acrylic acid ester or a methacrylic acid ester that does not correspond to the hydrophilic functional group-containing polymerizable monomer and the crosslinkable monomer. To do. The said (meth) acrylic acid ester monomer component consists of 1 type (s) or 2 or more types of this (meth) acrylic acid ester monomer.

  Examples of the (meth) acrylate monomer include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, and n- (meth) acrylate. Butyl, isobutyl (meth) acrylate, t-butyl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, 3-phenylpropyl (meth) acrylate, n-amyl (meth) acrylate , Alkyl such as isoamyl (meth) acrylate, octyl (meth) acrylate, 2-phenoxyethyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, decyl (meth) acrylate, lauryl (meth) acrylate A (meth) acrylic acid ester having 1 to 18 carbon atoms is preferred.

  In particular, from the viewpoint of easily obtaining crosslinked fine particles having a uniform particle diameter, it is preferable that at least methyl (meth) acrylate or ethyl (meth) acrylate is included as the (meth) acrylate monomer. Preferably at least methyl methacrylate is included.

  Although content in particular of a (meth) acrylic acid ester monomer component is not restrict | limited, It is preferable that it is 40-89.9 mass parts with respect to 100 mass parts of said monomer compositions. More preferably, it is 50-80 mass parts, More preferably, it is 60-70 mass parts.

The monomer composition contains the essential monomer components ((meth) acrylic acid ester monomer component, crosslinkable monomer component and hydrophilic functional group) as long as the effects of the present invention are not impaired. In addition to the polymerizable monomer component), other monomers may be included. Other monomers are not particularly limited, and examples thereof include styrenes such as styrene, α-methylstyrene, paramethylstyrene, isopropenylstyrene, chlorostyrene; acrylonitrile, methacrylonitrile, ethacrylonitrile, phenylacrylonitrile, and the like. Unsaturated nitriles; vinyl toluene; epoxy group-containing monomers such as allyl glycidyl ether; In addition, only 1 type may be sufficient as another monomer, and 2 or more types may be sufficient as it.
When the monomer composition contains the other monomer, the content is preferably 20 parts by mass or less, more preferably 10 parts by mass with respect to 100 parts by mass of the monomer composition. Part by mass, more preferably 5 parts by mass or less.
In the present specification, the description “with respect to 100 parts by mass of the monomer composition” refers to essential monomer components ((meth) acrylic acid ester monomer component, crosslinkable monomer component and hydrophilicity). When only the polymerizable monomer component having a functional functional group) is used, it means that the total mass of the essential monomer components is 100 parts by mass, together with the essential monomer components, the other single amount. When a body is also used, it means that the total mass including other monomers is 100 parts by mass.

  The crosslinked fine particles are formed by polymerizing the monomer composition. Since the formed microparticles are cross-linked, the cross-linked microparticle dispersion of the present invention has high heat resistance and can exhibit good storage stability even when stored at high temperatures.

  The average particle size of the crosslinked fine particles is preferably 0.005 to 0.2 μm. As a minimum, 0.01 micrometer or more is more preferable, More preferably, it is 0.04 micrometer or more, As an upper limit, 0.15 micrometer or less is more preferable, More preferably, it is 0.10 micrometer or less. In general, when the particle size is small, aggregation tends to occur during storage, and the crosslinked fine particle dispersion of the present invention can exert an excellent aggregation suppressing effect. Therefore, the particle size of the crosslinked fine particles is in a very small range as described above. It becomes possible to set. By setting the average particle diameter of the crosslinked fine particles within the above range, for example, when used as a slipping agent or an antiblocking agent for various thin layer films, the thin layer film can be made thinner. Moreover, when it uses as a base material particle | grain of a spacer or electroconductive fine particles, it can contribute to size reduction etc. of an electronic device. The average particle diameter of the crosslinked fine particles in the present invention means a volume average particle diameter measured by a dynamic light scattering method.

  The coefficient of variation (CV value) of the crosslinked fine particles is preferably 50% or less, more preferably 40% or less.

  The content of the crosslinked fine particles in the crosslinked fine particle dispersion may be appropriately set depending on the application and is not particularly limited. For example, it is preferably 5 to 30 parts by mass with respect to 100 parts by mass of the crosslinked fine particle dispersion. Preferably it is 5-20 mass parts. If the content of the crosslinked fine particles is less than 5 parts by mass with respect to 100 parts by mass of the crosslinked fine particle dispersion, it is not economical. On the other hand, when the content of the crosslinked fine particles is more than 30 parts by mass with respect to 100 parts by mass of the crosslinked fine particle dispersion, the crosslinked fine particles may not be stably produced.

1.2. Surfactant The surfactant constituting the crosslinked fine particle dispersion of the present invention is not particularly limited, and a known surfactant can be used, but an anionic surfactant is preferable. Thereby, a particle polymer having a small particle size and a narrow particle size distribution can be obtained. Examples of the anionic surfactant include sodium lauryl sulfonate and sodium dodecyl benzene sulfonate. Among these, sodium dodecyl benzene sulfonate is particularly preferable. In addition, only 1 type may be sufficient as surfactant, and 2 or more types may be sufficient as it.

  As content of surfactant in a crosslinked fine particle dispersion, 0.001-20 mass parts is preferable with respect to 100 mass parts of crosslinked fine particle dispersion, and 0.1-15 mass parts is more preferable. If the amount of the surfactant is too small, the dispersibility of the crosslinked fine particles tends to be low. On the other hand, if the amount is too large, the hygroscopicity of the crosslinked fine particles may increase or the crosslinked fine particle dispersion may easily foam. is there.

1.3. Basic substance As the basic substance constituting the crosslinked fine particle dispersion of the present invention, ammonia, monoethanolamine, diethanolamine, triethanolamine, methylamine, dimethylamine, ethylamine, diethylamine, trimethylamine, triethylamine, picoline, aniline, Amines such as pyridine, piperidine, morpholine, N-methylaniline, toluidine, N, N-dimethyl-p-toluidine; alkali metal hydroxides such as sodium hydroxide and potassium hydroxide; sodium methoxide, sodium ethoxide, Metal alkoxides such as sodium butoxide; and the like. Of these, weakly basic substances such as ammonia and monoethanolamine are preferred, and monoethanolamine is most preferred. By using these weakly basic substances, the addition shock at the time of addition of the basic substance is alleviated, and a crosslinked fine particle dispersion excellent in storage stability can be obtained.

  The content of the basic substance in the crosslinked fine particle dispersion is preferably 20 mol or more and 500 mol or less, more preferably 100 mol or less, with respect to 100 mol of the hydrophilic functional group-containing polymerizable monomer component constituting the crosslinked fine particle. It is 30 mol or more and 200 mol or less, More preferably, it is 90 mol or less, Especially preferably, it is 70 mol or less. If the content of the basic substance is too small, the effect of the present invention for improving the storage stability when stored for a long period of time at a high temperature may not be sufficiently obtained. The liquid may be colored. When the content of the basic substance is within the above range, the dispersibility of the crosslinked fine particles is increased, and the storage stability of the crosslinked fine particle dispersion is further improved.

1.4. Other Components The crosslinked fine particle dispersion of the present invention may further contain other compounds such as a solvent.
Although it does not specifically limit as a solvent, For example, alcohol; alcohol, such as water; methanol, ethanol, isopropanol, etc. are mentioned. Preferably, it contains water. When a solvent contains water, as content of water, 50-100 mass parts is preferable with respect to 100 mass parts of solvent, and 80-100 mass parts is more preferable. Only one type of solvent may be used, or two or more types of solvents may be used.
The content of the solvent is preferably 0 to 94 parts by mass, more preferably 5 parts by mass or more and 80 parts by mass or less, further preferably 10 parts by mass or more and 70 parts by mass or less with respect to 100 parts by mass of the crosslinked fine particle dispersion. It is.

1.5. Physical Properties The pH of the crosslinked fine particle dispersion of the present invention is preferably 5 to 14, more preferably 6 to 14, and still more preferably 6 to 12. When the pH of the dispersion is within the above range, the dispersibility of the crosslinked fine particles is increased, and the storage stability of the crosslinked fine particle dispersion is improved.

2. Method for Producing Crosslinked Fine Particle Dispersion The method for producing the crosslinked fine particle dispersion of the present invention comprises a (meth) acrylic acid ester monomer component, a crosslinkable monomer component, and a polymerizable monomer component having a hydrophilic functional group. It includes a polymerization step in which a monomer composition is emulsion-polymerized in the presence of a surfactant to prepare crosslinked fine particles, and an addition step in which a basic substance is added.

2.1. Polymerization step In the polymerization step, a polymerizable composition containing the monomer composition and a surfactant (emulsifier) together with a polymerization initiator is subjected to emulsion polymerization. A preferred embodiment of emulsion polymerization in the polymerization step is an emulsion polymerization step of emulsion polymerization of a polymerizable composition containing a polymerization initiator and a surfactant (emulsifier) together with the monomer composition, and further after the emulsion polymerization step. An aging step of aging the reaction solution obtained in the emulsion polymerization step with or without adding a surfactant. Emulsion polymerization is usually performed in an aqueous dispersion medium.

There is no restriction | limiting in particular as a polymerization initiator used for the said emulsion polymerization, Although a well-known polymerization initiator can be used, Preferably it is good to use a redox type polymerization initiator. For example, it is preferable to use a redox polymerization initiator that is a combination of hydrogen peroxide and at least one reducing agent selected from the group consisting of ascorbic acid, tartaric acid, and sorbic acid. Thereby, a particle polymer having a small particle size and a narrow particle size distribution can be obtained. When such a redox polymerization initiator is used, the polymerization initiator may be added by making each aqueous solution of hydrogen peroxide and reducing agent, and then adding each aqueous solution into the reaction vessel continuously or intermittently. Alternatively, the entire amount of the hydrogen peroxide solution may be added in advance to the reaction vessel, and an aqueous solution of a reducing agent may be continuously added.
The amount of the polymerization initiator used is not particularly limited, but is preferably 0 from the viewpoint of increasing the polymerization rate and reducing the remaining amount of unreacted monomer components with respect to 100 parts by mass of the monomer composition, for example. 0.05 parts by mass or more, more preferably 0.1 parts by mass or more, and preferably 5 parts by mass or less from the viewpoint of polymerization stability.

As the surfactant used in the emulsion polymerization step, it is preferable to use the surfactant constituting the crosslinked fine particle dispersion. Therefore, specifically, an anionic surfactant is preferably used, but a nonionic surfactant such as polyoxyethylene alkyl ether can also be used.
The amount of the surfactant used in the emulsion polymerization step is preferably 0.05 parts by mass or more and 10 parts by mass or less, and more preferably 5 parts by mass or less with respect to 100 parts by mass of the polymerizable monomer composition.

  As the aqueous dispersion medium used in the emulsion polymerization step, a solvent constituting the crosslinked fine particle dispersion can be preferably used, and water is particularly preferably used. The usage amount of the aqueous dispersion medium can be appropriately set so that the content of the crosslinked fine particles formed by polymerization becomes a desired ratio.

The emulsion polymerization may be performed by a known emulsion polymerization method. For example, a monomer dropping method, a pre-emulsion method, a batch charging polymerization method, or the like can be adopted. However, in order to obtain a crosslinked particle polymer having a narrow particle size distribution. It is preferable to employ a monomer dropping method.
In the emulsion polymerization, the monomer composition, the polymerization initiator, the surfactant charging method and the like are not particularly limited and may be appropriately set. Preferably, 5 mass of the total amount of the monomer composition is preferably set in advance. % After starting emulsion polymerization using a polymerization mixture composed of at least%, a part of a polymerization initiator and a surfactant, and then dropping the remaining monomer composition and polymerization initiator separately or mixed It is good to do.

  The polymerization temperature in the emulsion polymerization may be appropriately set according to the polymerization initiator to be used, but is preferably 30 to 90 ° C, for example. The polymerization time may be appropriately set according to the reaction rate determined from the charged amount of the monomer composition and the residual amount in the reaction solution, but is usually 1 to 12 hours, preferably about 2 to 8 hours. is there.

In the aging step, after the emulsion polymerization step, the unreacted monomer composition is reduced, or the dispersion liquid containing polymer particles (crosslinked fine particles) obtained by emulsion polymerization is stabilized. To be done. At this time, when a surfactant is added, aggregation of the crosslinked fine particles during aging is easily suppressed.
As the surfactant used in the aging step, it is preferable to use a surfactant constituting the crosslinked fine particle dispersion. Therefore, specifically, an anionic surfactant is preferably used, but a nonionic surfactant such as polyoxyethylene alkyl ether can also be used. It is particularly preferable to use the same surfactant as that used in the emulsion polymerization step as the surfactant used in the aging step.
The amount of the surfactant used in the aging step is preferably 0.05 parts by mass or more and 0.1 parts by mass or more with respect to 100 parts by mass of the polymerizable monomer composition used in the emulsion polymerization step. Further preferred. Moreover, 10 mass parts or less are preferable.

  The aging temperature in the aging step is preferably 50 to 90 ° C, more preferably 70 to 85 ° C. By setting the aging temperature within the above range, the amount of the unreacted monomer composition can be reduced while suppressing the aggregation of particles. The aging time may be appropriately set according to the reaction rate determined from the charged amount of the monomer composition and the remaining amount in the reaction solution, but is usually about 1 to 12 hours, preferably about 2 to 8 hours. .

2.2. Addition Step The reaction solution obtained in the polymerization step contains crosslinked fine particles produced by the polymerization reaction and a surfactant used as an emulsifier. Therefore, in the addition step, a basic substance is added to the reaction liquid or the reaction raw material mixture before becoming the reaction liquid. Thereby, the crosslinked fine particle dispersion of the present invention is obtained. The timing of the addition process, that is, the addition of the basic substance is not particularly limited, and may be performed, for example, on the reaction solution obtained after the polymerization process or before the polymerization process. It may be performed on at least one of the product, the surfactant and the polymerization initiator, or may be performed simultaneously with the polymerization step by adding it to the reaction system during the polymerization reaction. Preferably, after the polymerization step, a basic substance is added to the dispersion containing the crosslinked fine particles and the surfactant.

When adding the basic substance, it is preferable to add while stirring the side to be added, such as a dispersion containing crosslinked fine particles and a surfactant, in order to efficiently suppress the formation of aggregates. The basic substance may be added without diluting, but from the viewpoint of suppressing the formation of aggregates, a form in which the basic substance is diluted with a solvent and added as a basic substance solution is also preferable.
Although it does not specifically limit as addition temperature (temperature at the side of addition) in an addition process, 0-90 degreeC is preferable and 40-60 degreeC is more preferable.

3. Use of Crosslinked Fine Particle Dispersion The crosslinked fine particle dispersion of the present invention is composed of conductive fine particles, insulating materials such as insulating coating materials, charge control materials such as toner external additives, various film film modifying materials, etc. Available to: Other optical applications such as light diffusing plates (light diffusing sheets), light guide plates, plastic substrates for various displays, substrates for touch panels; antistatic coating agents for copiers or printers, charge holders, toner transfer members, fixing belts , Intermediate transfer belts, film resistors, conductive paste, battery materials such as lithium ion batteries (electrode materials, binders, etc.), antistatic resins, conductive adhesive layers for capacitors, conductive sliding members, circuit boards Substrate, heat-resistant semiconductive material, self-temperature controlled energization heating element, thermal head heating resistor, recording energization heating sheet, wire cable covering, planar heating element electromagnetic wave shielding sheet, flexible wiring sheet, electromagnetic wave absorption sheet Applications for electronic components such as heat-absorbing sheets and UV-absorbing sheets; Shielding applications such helix; surface treatment agent of the low-noise gears, sliding applications such friction material molded; even like, can be utilized crosslinked microparticle dispersion of the present invention. In addition, substrates for electronic devices (for example, optical conversion device substrates such as optical sensor substrates and optical switch substrates, printed wiring substrates, thermal head substrates, etc.), inkjet inks, water-dispersed paints, abrasives, The present invention can be applied to known uses in which crosslinked fine particles are conventionally used, such as additives for lubricating liquids.

  In particular, the crosslinked fine particle dispersion according to the present invention is preferably added to a resin emulsion and used as a water-based paint. Such a water-based paint contains the crosslinked fine particle dispersion of the present invention and a resin emulsion, and by including the crosslinked fine particle dispersion of the present invention, an increase in viscosity over time is suppressed even if a thickener is included, It has excellent paint stability. In addition, when the crosslinked fine particle dispersion of the present invention is contained, the effect that the water resistance of the coating film formed from the water-based paint is remarkably improved can be obtained.

  There is no restriction | limiting in particular as a resin emulsion, The well-known resin emulsion conventionally used for the paint use can be used. The resin emulsion can be obtained by polymerizing a monomer component having a polymerizable double bond in the presence of an emulsifier.

  The monomer component used in preparing the resin emulsion may be either a monofunctional monomer having one polymerizable double bond or a polyfunctional monomer having two or more polymerizable double bonds. It may be a mixture of both. In addition, each monofunctional monomer and polyfunctional monomer may be one kind or two or more kinds.

  Examples of the monofunctional monomer include (meth) acrylic acid, maleic acid, fumaric acid, crotonic acid, itaconic acid, citraconic acid, maleic anhydride, maleic acid monomethyl ester, maleic acid monobutyl ester, and itaconic acid monomethyl. Carboxyl group-containing monomers such as esters, itaconic acid monobutyl ester, vinyl benzoic acid;

  Methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, sec- Butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, tridecyl (meth) acrylate, cyclohexyl (meth) acrylate, n-lauryl (meth) acrylate, dodecyl (meth) acrylate, stearyl ( Alkyl (meth) acrylates such as (meth) acrylate and isobornyl (meth) acrylate;

  Hydroxyl-containing (meta) such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate ) Acrylate;

  4- (meth) acryloyloxy-2,2,6,6-tetramethylpiperidine, 4- (meth) acryloylamino-2,2,6,6-tetramethylpiperidine, 4- (meth) acryloyloxy-1, 2,2,6,6-pentamethylpiperidine, 4- (meth) acryloyl-1-methoxy-2,2,6,6-tetramethylpiperidine, 4-cyano-4- (meth) acryloyloxy-2,2 , 6,6-tetramethylpiperidine, 1- (meth) acryloyl-4- (meth) acryloylamino-2,2,6,6-tetramethylpiperidine, 4-crotonoylamino-2,2,6,6- Tetramethylpiperidine, 4- (meth) acryloylamino-1,2,2,6,6-pentamethylpiperidine, 4-cyano-4- (meth) acryloylamino- , 2,6,6-tetramethylpiperidine, 4-crotonoyloxy-2,2,6,6-tetramethylpiperidine, 1- (meth) acryloyl-4-cyano-4- (meth) acryloylamino-2, Piperidine group-containing monomers such as 2,6,6-tetramethylpiperidine, 1-crotonoyl-4-crotonoyloxy-2,2,6,6-tetramethylpiperidine;

Oxo group-containing monomers such as (di) ethylene glycol (methoxy) (meth) acrylate such as ethylene glycol (meth) acrylate, ethylene glycol methoxy (meth) acrylate, diethylene glycol (meth) acrylate, diethylene glycol methoxy (meth) acrylate;
Fluorine atom-containing monomers such as trifluoroethyl (meth) acrylate, tetrafluoropropyl (meth) acrylate and octafluoropentyl (meth) acrylate;

  (Meth) acrylamide, N-monomethyl (meth) acrylamide, N-monoethyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, Nn-propyl (meth) acrylamide, N-isopropyl (meth) acrylamide, methylenebis Acrylamide compounds such as (meth) acrylamide, N-methylol (meth) acrylamide, N-butoxymethyl (meth) acrylamide, dimethylaminoethyl (meth) acrylamide, N, N-dimethylaminopropyl acrylamide, diacetone acrylamide, dimethylaminoethyl Nitrogen atom-containing (meth) acrylate compounds such as (meth) acrylate and diethylaminoethyl (meth) acrylate, N-vinylpyrrolidone, and (meth) acrylonitrile Monomer;

Epoxy group-containing monomers such as glycidyl (meth) acrylate, α-methylglycidyl (meth) acrylate, glycidyl allyl ether;
Alkoxyalkyl (meth) acrylates such as methoxyethyl (meth) acrylate, methoxybutyl (meth) acrylate, ethoxybutyl (meth) acrylate, trimethylolpropane tripropoxy (meth) acrylate;

  Vinyltrimethoxysilane, vinyltriethoxysilane, vinyltri (methoxyethoxy) silane, γ- (meth) acryloyloxypropyltrimethoxysilane, 2-styrylethyltrimethoxysilane, vinyltrichlorosilane, γ- (meth) acryloyloxypropylhydroxy Silane-containing monomers such as silane and γ- (meth) acryloyloxypropylmethylhydroxysilane;

  Acrolein, humylstyrene, vinyl ethyl ketone, (meth) acryloxyalkylpropenal, acetonyl (meth) acrylate, diacetone (meth) acrylate, 2-hydroxypropyl (meth) acrylate acetyl acetate, butanediol-1,4-acrylate Carbonyl group-containing monomers such as acetyl acetate and 2- (acetoacetoxy) ethyl (meth) acrylate;

Aziridinyl group-containing monomers such as (meth) acryloylaziridine, (meth) acrylic acid 2-aziridinylethyl;
In addition to styrene, α-methylstyrene, p-methylstyrene, tert-methylstyrene, chlorostyrene, vinyltoluene, etc., these benzene rings have an alkyl group (methyl group, tert-butyl group, etc.), nitro group, nitrile group, Styrenic monomers such as monomers having functional groups such as alkoxyl groups, acyl groups, sulfone groups, hydroxyl groups, halogen atoms;
And aralkyl (meth) acrylates such as benzyl (meth) acrylate, phenylethyl (meth) acrylate, methylbenzyl (meth) acrylate, and naphthylmethyl (meth) acrylate;

  Examples of the polyfunctional monomer include ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, 1,3-butanediol di (meth) acrylate, and 1,4-butanediol di (meth) acrylate. 1,6-hexanediol di (meth) acrylate, ethylene oxide modified 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, propylene oxide modified neopentyl glycol di (meth) acrylate Di (meth) acrylates of polyhydric alcohols having 1 to 10 carbon atoms such as tripropylene glycol di (meth) acrylate;

  2 carbon atoms such as polyethylene glycol di (meth) acrylate having 2-50 addition moles of ethylene oxide, polypropylene glycol di (meth) acrylate having 2-50 addition moles of propylene oxide, tripropylene glycol di (meth) acrylate, etc. Alkyl di (meth) acrylates having an added mole number of -4 alkylene oxide groups of 2-50;

  Ethoxylated glycerin tri (meth) acrylate, propylene oxide modified glycerol tri (meth) acrylate, ethylene oxide modified trimethylolpropane tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol monohydroxytri (meth) acrylate, tri A tri (meth) acrylate of a polyhydric alcohol having 1 to 10 carbon atoms such as methylolpropane triethoxytri (meth) acrylate;

Tetra (meth) acrylates of polyhydric alcohols having 1 to 10 carbon atoms such as pentaerythritol tetra (meth) acrylate, dipentaerythritol tetra (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate;
Penta (meth) acrylates of polyhydric alcohols having 1 to 10 carbon atoms such as pentaerythritol penta (meth) acrylate and dipentaerythritol (monohydroxy) penta (meth) acrylate;

A hexa (meth) acrylate of a polyhydric alcohol having 1 to 10 carbon atoms such as pentaerythritol hexa (meth) acrylate;
Epoxy group-containing (meth) acrylates such as bisphenol A di (meth) acrylate, 2- (2′-vinyloxyethoxyethyl) (meth) acrylate, and epoxy (meth) acrylate;
And polyfunctional (meth) acrylates such as urethane (meth) acrylate;

  The emulsifier that can be used for the preparation of the resin emulsion is not particularly limited, and examples thereof include known anionic surfactants, cationic surfactants, nonionic surfactants, amphoteric surfactants, and polymer surfactants. In addition to these surfactants, reactive emulsifiers and the like can be used. The amount of the emulsifier used may be appropriately set, but from the viewpoint of improving the polymerization stability per 100 parts by mass of the total amount of the monomer components, preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, The amount is preferably 3 parts by mass or more, and preferably 10 parts by mass or less, more preferably 6 parts by mass or less, and still more preferably 5 parts by mass or less, from the viewpoint of obtaining an aqueous paint excellent in paint stability and water resistance.

  There is no restriction | limiting in particular as a polymerization initiator which can be used for preparation of a resin emulsion, For example, persulfates, such as potassium persulfate, ammonium persulfate, sodium persulfate; 2,2'-azobis (2-amidinopropane) Water-soluble azo compounds such as dihydrochloride and 4,4′-azobis (4-cyanopentanoic acid); thermal decomposition initiators such as hydrogen peroxide; hydrogen peroxide and ascorbic acid, t-butyl hydroperoxide and longalite In addition, redox polymerization initiators such as potassium persulfate and metal salts, ammonium persulfate and sodium hydrogen sulfite can be used. The amount of the polymerization initiator used may be set as appropriate. From the viewpoint of increasing the polymerization rate and reducing the remaining amount of the unreacted monomer component per 100 parts by mass of the total amount of monomer components, it is preferably 0.00. 05 parts by mass or more, more preferably 0.1 parts by mass or more, and from the viewpoint of polymerization stability, it is preferably 3 parts by mass or less, more preferably 1 part by mass or less.

  For the emulsion polymerization in preparing the resin emulsion, a chain transfer agent, a chelating agent, a dispersing agent and the like may be used as necessary. The conditions for emulsion polymerization may be appropriately set. For example, the polymerization temperature is preferably 60 to 95 ° C., and the polymerization time is preferably 2 to 9 hours. The addition method of the monomer component, the polymerization initiator and the like is not particularly limited, and a batch addition method, a continuous addition method, a multistage addition method, or the like can be applied. For example, emulsion particles can be formed into a plurality of layers by performing the emulsion polymerization reaction in a plurality of stages. The particle diameter of the emulsion particles is usually about 70 to 250 nm in terms of volume average particle diameter.

  In the water-based paint according to the present invention, the mixing ratio of the crosslinked fine particle dispersion of the present invention and the resin emulsion is 10 to 100 parts by mass of the resin emulsion with respect to 100 parts by mass of the crosslinked fine particle dispersion as a solid content ratio. preferable. If the amount of the crosslinked fine particle dispersion is too small, the viscosity tends to increase with time. Conversely, if the amount of the crosslinked fine particle dispersion is too large, the water resistance of the coating film formed by the water-based paint may be lowered. is there.

  In addition to the crosslinked fine particle dispersion and the resin emulsion, the water-based paint includes a thickener, a film forming aid, a foam suppressor, an ultraviolet absorber, an ultraviolet stabilizer, a filler, a leveling agent, and a dispersant as necessary. , Wetting agents, plasticizers, stabilizers, dyes, pigments, antioxidants and other known additives may be included in appropriate amounts. In particular, the thickener is preferably blended in the paint for the purpose of preventing sagging during coating and preventing sedimentation of the emulsion particles during storage.

  The thickener is not particularly limited, and various known thickeners can be used. For example, inorganic thickeners such as silicates such as water-soluble aluminum silicate, montmorillonite, organically modified montmorillonite, colloidal alumina; cellulose derivative thickeners such as carboxymethylcellulose, methylcellulose, and hydroxyethylcellulose; casein, casein acid Protein rheology control agents such as sodium and ammonium caseinate; Alginic acid thickeners such as sodium alginate; Polyvinyl thickeners such as polyvinyl alcohol, polyvinylpyrrolidone and polyvinyl-benzyl ether copolymers; Sodium polyacrylate, alkali Polyacrylic acid thickeners such as soluble (meth) acrylic acid- (meth) acrylic acid ester copolymers; Pluronic (registered trademark) polyether, polyether dial Polyether thickeners such as ether esters, polyether dialkyl ethers, polyether urethane associative group modified products, polyether epoxy modified products; partial esters of vinyl methyl ether-maleic anhydride copolymer, drying oil fatty acid allyl alcohol ester and And a maleic anhydride copolymer thickener such as a half ester of a reaction product with maleic anhydride; a thickening polysaccharide such as acetylene glycol, xanthan gum, xanthan gum and starch; In particular, cellulose derivative thickeners, alkali-soluble thickeners such as alkali-soluble (meth) acrylic acid- (meth) acrylic acid ester copolymers, and urethane-associated types such as polyether urethane-associated group modified products Thickeners are preferred because they are readily available commercially. Examples of commercially available products include hydroxyethyl cellulose “SP-800” and “SP-850” manufactured by Daicel Chemical Industries, Ltd. as cellulose derivative thickeners. ) “Acryset (registered trademark) WR-507” and “Acreset (registered trademark) WR-650” manufactured by Nippon Shokubai Co., Ltd., and urethane-associative thickeners such as “ADEKANOL” manufactured by ADEKA Corporation (Registered trademark) UH-420 "," Adecanol (registered trademark) UH-438 "," Adecanol (registered trademark) UH-450VF ", and the like.

  When the water-based paint concerning this invention contains a thickener, it is preferable that content of a thickener is 0.01-5 mass parts with respect to 100 mass parts of resin emulsion (solid content).

  This application claims the benefit of priority based on Japanese Patent Application No. 2013-69672 filed on Mar. 28, 2013. The entire contents of the specification of Japanese Patent Application No. 2013-69672 filed on March 28, 2013 are incorporated herein by reference.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto.
Various physical properties were measured and evaluated by the following methods.

(Measurement of average particle diameter and coefficient of variation (CV value) of crosslinked fine particles)
The obtained crosslinked fine particle dispersion was diluted with ion-exchanged water and measured with a light scattering particle size distribution analyzer (“NicompMODEL380” manufactured by Particle Sizing Systems) to obtain a volume average particle size (μm). The average particle size of the crosslinked fine particles was used. The standard deviation calculation was calculated based on the volume average particle diameter and particle diameter obtained by the above apparatus, and the coefficient of variation (CV value:%) was determined from the following equation.
Coefficient of variation (CV value:%) = 100 × (standard deviation / volume average particle diameter)

(Storage stability evaluation)
The pH of the crosslinked fine particle dispersion obtained with a pH sensor (“F-21” manufactured by Horiba, Ltd.) was measured.
Thereafter, a heating test is performed in which the obtained dispersion is allowed to stand at 85 ° C. for 3 days, and the ratio of the average particle diameter of the crosslinked fine particles in the dispersion before and after the heating test, specifically, (after the heating test Average particle diameter / average particle diameter before heating test) × 100 (%) was determined. The closer the average particle size ratio is to 100%, the better the storage stability.
Further, the degree of coloring of the dispersion after the heating test was visually observed and evaluated according to the following criteria.
Excellent: Not colored Good: Slightly colored Bad: Colored

(Evaluation of redispersibility in solvents)
The obtained crosslinked fine particle dispersion was pulverized by a spray drying method to obtain an aggregate of crosslinked fine particles, and 9 parts by mass of methanol was added to 1 part by mass of the obtained aggregate, followed by ultrasonic dispersion for 10 minutes. . The ratio of the average particle diameter of the crosslinked fine particles in the dispersion before and after redispersion, specifically, the value of (average particle diameter after redispersion / average particle diameter before redispersion) × 100 (%) was determined. Here, the “average particle size before redispersion” was the same value as the “average particle size before heating test” in the storage stability evaluation. Note that the closer this ratio is to 100%, the better the redispersibility in the solvent.

Example 1
840 parts by mass of deionized water and 4.3 parts by mass of sodium dodecylbenzenesulfonate (active ingredient 65% by mass; hereinafter referred to as “DBSNa”) are added to a stainless steel reaction kettle equipped with a stirrer, a thermometer and a cooler. The internal temperature was raised to 75 ° C. and kept at the same temperature.
On the other hand, in a reaction vessel different from the reaction kettle, 130 parts by mass of methyl methacrylate (hereinafter referred to as “MMA”), 60 parts by mass of divinylbenzene (81% by mass of active ingredient; hereinafter referred to as “DVB”) and acrylic acid ( 10 parts by mass (hereinafter referred to as “AA”) (0.139 parts by mol) were mixed to prepare 200 parts by mass of a monomer composition.

After replacing the inside of the reaction kettle with nitrogen gas, 20 parts by mass of the monomer composition (10% by mass of the total amount of the monomer composition), 50% hydrogen peroxide (hydrogen peroxide concentration 0.27% by mass) An initial polymerization reaction was carried out by adding 50 parts by mass of an L-ascorbic acid aqueous solution (concentration of L-ascorbic acid 0.40% by mass) in the reaction kettle.
Subsequently, the remainder of the monomer composition (90% by mass of the total amount of the monomer composition) 180 parts by mass, 450 parts by mass of hydrogen peroxide (hydrogen peroxide concentration 0.27% by mass), and L-ascorbic acid 450 parts by mass of an aqueous solution (L-ascorbic acid concentration 0.40% by mass) was uniformly added dropwise to the reaction kettle from each different inlet over 4 hours. Thereafter, the internal temperature was raised to 85 ° C. and kept at the same temperature for 2 hours for aging, and then 2.8 parts by mass (0.046 mol part) of monoethanolamine (hereinafter referred to as “MEA”) was added. . Thereafter, the reaction solution was cooled to obtain a crosslinked fine particle dispersion (1) in which crosslinked fine particles were dispersed. Table 1 shows the monomer composition, basic substance, and evaluation results of the obtained crosslinked fine particles.

Example 2
A crosslinked fine particle dispersion (2) in which crosslinked fine particles were dispersed was obtained in the same manner as in Example 1 except that the amount of MEA added was changed to 4.2 parts by mass (0.069 mol part). Table 1 shows the monomer composition, basic substance, and evaluation results of the obtained crosslinked fine particles.

Reference example 3
A crosslinked fine particle dispersion (3) in which crosslinked fine particles were dispersed was obtained in the same manner as in Example 1 except that the MEA addition amount was changed to 6.4 parts by mass (0.105 mol part). Table 1 shows the monomer composition, basic substance, and evaluation results of the obtained crosslinked fine particles.

Reference example 4
A crosslinked fine particle dispersion (4) in which crosslinked fine particles were dispersed was obtained in the same manner as in Example 1 except that the amount of MEA added was changed to 8.5 parts by mass (0.139 mol part). Table 1 shows the monomer composition, basic substance, and evaluation results of the obtained crosslinked fine particles.

Example 5
MMA 130 parts by weight, DVB 60 parts by weight, methacrylic acid (hereinafter referred to as “MAA”) 10 parts by weight (0.116 parts by mole), MEA added amount to 3.6 parts by weight (0.059 parts by weight) A crosslinked fine particle dispersion (5) in which crosslinked fine particles were dispersed was obtained in the same manner as in Example 1 except for the change. Table 1 shows the monomer composition, basic substance, and evaluation results of the obtained crosslinked fine particles.

Example 6
Example except that the basic substance added after the polymerization step was changed to 3.97 parts by mass of ammonia water (ammonia concentration 25% by mass) (active ingredient amount: 0.99 parts by mass (0.058 parts by mol)) In the same manner as in No. 1, a crosslinked fine particle dispersion (6) in which crosslinked fine particles were dispersed was obtained. Table 1 shows the monomer composition, basic substance, and evaluation results of the obtained crosslinked fine particles.

Example 7
MMA 130 parts by weight, DVB 60 parts by weight, MAA 10 parts by weight (0.116 moles), basic substance added after the polymerization step is ammonia water (ammonia concentration 25% by weight) 3.96 parts by weight (active ingredient amount) : A crosslinked fine particle dispersion (7) in which crosslinked fine particles were dispersed was obtained in the same manner as in Example 1 except that the content was changed to 0.99 parts by mass (0.058 mol parts). Table 1 shows the monomer composition, basic substance, and evaluation results of the obtained crosslinked fine particles.

Example 8
130 parts by mass of MMA, 60 parts by mass of DVB, 10 parts by mass of MAA (0.116 mol), and a basic substance added after the polymerization step is 8.66 parts by mass of triethanolamine (hereinafter referred to as “TEA”) (0 Except for the change to 0.058 mol part), a crosslinked fine particle dispersion (8) in which crosslinked fine particles were dispersed was obtained in the same manner as in Example 1. Table 1 shows the monomer composition, basic substance, and evaluation results of the obtained crosslinked fine particles.

Comparative Example 1
A crosslinked fine particle dispersion (9) in which crosslinked fine particles were dispersed was obtained in the same manner as in Example 1 except that MEA was not added. Table 1 shows the monomer composition, basic substance, and evaluation results of the obtained crosslinked fine particles.

Example 9
A crosslinked fine particle dispersion (10) in which crosslinked fine particles are dispersed is obtained in the same manner as in Example 1 except that the monomer is changed to 150 parts by mass of MMA, 40 parts by mass of DVB, and 10 parts by mass (0.139 mol part) of AA. It was. Table 1 shows the monomer composition, basic substance, and evaluation results of the obtained crosslinked fine particles.

Application examples (preparation and evaluation of paints)
Paints (A) to (D) were prepared using the resin composition for paints prepared by the following method and the crosslinked fine particle dispersion obtained in the above examples or comparative examples. Stability or coating water resistance was evaluated.

(Preparation method of resin composition for paint)
810 parts by mass of deionized water was charged into a flask equipped with a dropping funnel, a stirrer, a nitrogen gas inlet tube, a thermometer, and a reflux condenser. In a dropping funnel, 145 parts by mass of deionized water, 60 parts by mass of a 25% aqueous solution of an emulsifier ("Aqualon (registered trademark) HS-10" manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), 40 parts by mass of 2-ethylhexyl acrylate, 210 parts by mass of methyl methacrylate Part, 100 parts by mass of cyclohexyl methacrylate, 100 parts by mass of styrene, 10 parts by mass of methacrylic acid, and 40 parts by mass of ethylene glycol dimethacrylate, and 71 parts by mass (first stage) corresponding to 10% by mass And a polymerizable monomer component corresponding to 5% by mass of the total amount of the polymerizable monomer component in the second stage pre-emulsion) is added to the flask, and gently blown with nitrogen gas up to 80 ° C. After the temperature was raised, 14 parts by mass of a 3.5% by mass aqueous ammonium persulfate solution was added to conduct polymerization. Started it was. Next, the remaining part of the pre-emulsion in the first stage, 43 parts by mass of a 3.5% by mass ammonium persulfate aqueous solution, and 30 parts by mass of a 2.5% by mass sodium hydrogen sulfite aqueous solution were respectively added to the flask uniformly over 120 minutes. It was dripped in.

  After completion of dropping, the mixture is maintained at 80 ° C. for 60 minutes, and subsequently, 145 parts by mass of deionized water and 60 parts by mass of a 25% by mass aqueous solution of an emulsifier (“Aqualon (registered trademark) HS-10” manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 2-stage pre-emulsion consisting of 200 parts by weight of 2-ethylhexyl acrylate, 110 parts by weight of methyl methacrylate, 100 parts by weight of cyclohexyl methacrylate, 80 parts by weight of styrene and 10 parts by weight of acrylic acid, and 43 parts by weight of 3.5% by weight aqueous ammonium persulfate solution And 30 parts by mass of a 2.5% by mass aqueous sodium hydrogen sulfite solution were uniformly added dropwise over 120 minutes. After completion of the dropwise addition, the mixture was maintained at 80 ° C. for 120 minutes, and then the pH was adjusted to 8 by adding 25% by mass of aqueous ammonia to complete the polymerization. After cooling the obtained reaction liquid to room temperature, a resin emulsion is prepared by filtering through a 300 mesh (mesh based on JIS standard, hereinafter the same) wire mesh, and the obtained resin emulsion is used as a resin composition for paints. did. The non-volatile content in the coating resin composition was 43% by mass, and the volume average particle diameter of the emulsion particles was 150 nm.

(Preparation of paint A)
While dispersing 113.6 parts by mass of the resin composition for paints with a homodisper at a rotational speed of 1500 min ⁻¹ , 3.8 parts by mass of dipropylene glycol-n-butyl ether and 2.8 parts by mass of butyl cellosolve were used as film forming aids. And were added. Next, 50 parts by mass of the crosslinked fine particle dispersion (1) obtained in Example 1 and 0.3 part by mass of a foam suppressor (“SN deformer 777” manufactured by San Nopco Co., Ltd.) were added. Furthermore, a thickener (manufactured by ADEKA Co., Ltd.) is used so that the viscosity becomes 650 ± 100 mPa · s when measured at 25 ° C. using a B-type viscometer (“VISCOMETER TVB-10” manufactured by Toki Sangyo Co., Ltd.). After adding “Adecanol (registered trademark) UH-420”), the resulting mixture was stirred with a homodisper at a rotational speed of 1500 min ^{−1 for} 10 minutes to obtain paint A.

(Preparation of paint B)
A paint B was obtained in the same manner as in (Preparation of paint A) except that the crosslinked fine particle dispersion (9) obtained in Comparative Example 1 was used in place of the crosslinked fine particle dispersion (1).

(Preparation of paint C)
Paint C was prepared in the same manner as (Preparation of paint A), except that the type of thickener used was changed to a thickener ("Acryset (registered trademark) WR-507" manufactured by Nippon Shokubai Co., Ltd.). Obtained.

(Preparation of paint D)
Paint D was prepared in the same manner as (Preparation of paint B), except that the type of thickener used was changed to a thickener ("Acryset (registered trademark) WR-507" manufactured by Nippon Shokubai Co., Ltd.). Obtained.

(Stability evaluation over time)
About the coating material A and the coating material B, after measuring each initial viscosity, it stored at 50 degreeC for 3 days, and measured the viscosity after storage. The viscosity was measured at 25 ° C. using a B-type viscometer (“VISCOMETER TVB-10” manufactured by Toki Sangyo Co., Ltd.). The results are shown in Table 2. The smaller the change in viscosity before and after storage, the more stable the paint.

(Coating water resistance evaluation)
The coating plates C and D were applied to a glass plate using an applicator so that the film thickness was 45 μm, and then dried for 5 minutes with a hot air dryer at 100 ° C. to prepare test plates. The initial L value (L ₀ ) of the obtained test plate was measured using a color difference meter (“Spectroscopic color difference meter SE-2000” manufactured by Nippon Denshoku Industries Co., Ltd.). After immersing this test plate in water adjusted to 25 ° C. for 4 days, the test plate was pulled up from the water and wiped off with a paper towel (manufactured by Nippon Paper Crecia Co., Ltd.). The value (L ₁ ) was measured. Then, a change value of the L value was calculated based on the following formula: ΔL = (L ₁ ) − (L ₀ ). The results are shown in Table 3. A smaller value of ΔL indicates better water resistance.

  The crosslinked fine particle dispersion of the present invention can be used for conductive fine particle base particles, insulating materials such as insulating coating materials, fine particles such as charge control materials such as toner external additives, and various film film modifying materials. In particular, the crosslinked fine particle dispersion of the present invention is useful as an aqueous coating material.

Claims (3)

Including crosslinked fine particles, surfactant and basic substance,
The crosslinked fine particles are formed from a monomer composition containing a (meth) acrylic acid ester monomer component, a crosslinkable monomer component and a polymerizable monomer component having a hydrophilic functional group,
The content of the crosslinkable monomer component is 10 to 50 parts by mass with respect to 100 parts by mass of the monomer composition,
The content of the polymerizable monomer component having a hydrophilic functional group, Ri 0.1-20 parts by der respect to the monomer composition 100 parts by weight,
The basic substance is an amine;
The content of the basic substance, the hydrophilic functional groups 20 mol or more of the polymerizable monomer component 100 moles with, crosslinked microparticle dispersion which is characterized in der Rukoto 70 mol. The crosslinked fine particle dispersion according to claim 1 , wherein an average particle diameter of the crosslinked fine particles is in a range of 0.005 to 0.2 µm. Polymerization in which a monomer composition containing a (meth) acrylate monomer component, a crosslinkable monomer component and a polymerizable monomer component having a hydrophilic functional group is emulsion-polymerized in the presence of a surfactant. a step, the adding step of adding a basic substance seen including,
The amount of the crosslinkable monomer component is 10 to 50 parts by mass with respect to 100 parts by mass of the monomer composition, and the amount of the polymerizable monomer component having the hydrophilic functional group is 0.1 to 20 parts by mass with respect to 100 parts by mass of the mass composition,
The basic substance is an amine;
The method for producing a crosslinked fine particle dispersion , wherein the amount of the basic substance is 20 mol or more and 70 mol or less with respect to 100 mol of the polymerizable monomer component having the hydrophilic functional group .