JP2001335721A - Colloidal fine particle, method for manufacturing the same and coating composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain colloidal fine particles having high dispersion stability and storage stability even when the concentration of the particles is high. SOLUTION: The colloidal particles are produced by raising the temperature of a dispersion of inorganic or organic particles and a nonionic surfactant to a temperature not lower than the cloud point of the surfactant to thereby deposit the surfactant on the surface of the inorganic or organic particles. The colloidal fine particles may be combined with various binders (comprising e.g. an acrylic resin emulsion, a urethane resin emulsion, and an epoxy based emulsion) to form a coating composition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to colloidal fine particles having excellent dispersion stability, a method for producing the same, and a coating composition containing the colloidal fine particles.

[0002]

2. Description of the Related Art Colloidal silica is excellent in hardness, mechanical strength, antistatic property, chemical resistance and weather resistance, and organic polymer is excellent in flexibility, adhesion, water resistance and the like. Organic / inorganic composite aqueous compositions are known.

For example, there is known an aqueous coating material containing as a main component a mixture of a vinyl acetate emulsion, an acrylic emulsion, an acrylic-styrene emulsion, colloidal silica, a water-curable binder and the like. However, these aqueous coating agents have a small bonding force between the organic polymer and the inorganic substance, and do not have sufficient long-term durability, film forming property, water resistance, and the like. Further, in the coating composition using a blend system of the colloidal silica and the organic polymer as a binder, when the amount of the colloidal silica is increased, the film-forming property is reduced, and the contamination by the colloidal silica and the film-forming property are increased. It is difficult to balance both levels.

In order to chemically bond colloidal silica as an inorganic substance and an organic polymer, JP-A-59-7131 is used.
No. 6, JP-A-63-37168 discloses an aqueous resin dispersion obtained by copolymerizing a silane-based monomer and colloidal silica. JP-A-9-1942
No. 08 proposes to produce an aqueous dispersion of core-shell composite particles by coupling colloidal silica and organoalkoxysilane and then polymerizing a vinyl monomer. However, when using a colloidal silica having an average particle size of 50 nm or less that exhibits good strength, appearance, and transparency as a coating film, it is difficult to obtain an aqueous dispersion having a solid content of 40% by weight or more, At a high solids content, the viscosity increases significantly and the film formability is poor. Further, in order to obtain stable core-shell composite particles, it is necessary to use many special silane compounds having a methacryloyl group, which is disadvantageous in cost. Furthermore, the total reaction time is 10 hours or more, and it is not possible to industrially produce aqueous dispersions and binders for paints.

As described above, according to the conventional method, particles such as colloidal silica and the organic polymer cannot be stably dispersed for a long period of time, and both the stain resistance and the film forming property are compatible at a high level. Have difficulty. Further, even in the method of chemically bonding the particles and the organic polymer, the properties of the coating film are greatly influenced by a large amount of the silane compound and the vinyl monomer, so that the use of the obtained dispersion is limited.

[0006]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide colloidal fine particles having a high particle concentration and excellent in dispersion stability and storage stability even when mixed with a binder, and a method for producing the same. It is in.

Another object of the present invention is to provide a coating composition which can maintain the stain resistance and weather resistance of a coating film at a high level over a long period of time, and is excellent in film forming property and storage stability. .

Still another object of the present invention is to provide a coating composition which can easily impart desired properties to a coating film.

[0009]

Means for Solving the Problems In order to solve the above-mentioned problems, the present inventors have made intensive studies and found that irreversibly depositing a nonionic surfactant on the surface of inorganic or organic particles at a temperature higher than the cloud point. As a result, it has been found that colloidal fine particles having high dispersion stability can be obtained, and the present invention has been completed.

That is, the colloidal fine particles of the present invention are:
Nonionic surfactants are aggregated or aggregated and deposited on the surface of the inorganic or organic particles. Such colloidal fine particles, by raising the temperature of the dispersion system containing inorganic or organic particles and nonionic surfactant above the cloud point of the nonionic surfactant, to aggregate or aggregate the nonionic surfactant, It can be produced by depositing on the particle surface. The inorganic or organic particles may be colloidal silica or the like. The nonionic surfactant may have a cloud point of about 0 to 80 ° C. Further, the vinyl polymer may be bonded to the surface of the inorganic or organic particles directly or via a nonionic surfactant in a proportion of less than 20 parts by weight based on 100 parts by weight of the inorganic or organic particles. The vinyl polymer can be formed from a (meth) acrylic monomer, an aromatic vinyl monomer, a vinyl ester monomer, or the like.

[0011] The present invention also discloses a coating composition comprising the above-mentioned colloidal fine particles and a binder.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The colloidal fine particles of the present invention are composed of inorganic or organic particles (hereinafter simply referred to as core particles) and a nonionic surfactant deposited on the surface of the core particles. In the present invention, fine particles are usually used as the core particles.

[Inorganic core particles] As the inorganic core particles, various functional particles such as extender (silica), inorganic pigment,
A conductor (eg, gold, silver, platinum, aluminum, or an alloy thereof), a magnetic body (eg, ferrite), or the like can be used. These functional particles may be colloidal (for example, colloidal silica).

The colloidal silica particles (colloidal silica) have an average particle size of 5 nm to 1 μm, preferably 1 nm.
Colloids (colloids) of silica fine particles of about 0 to 100 nm can be used. For colloidal silica, JP-A-53-112732, JP-B-57-9051, and JP-A-57-51653 can be referred to. .

The colloidal silica can be prepared and used by a sol-gel method, or a commercially available product can be used. When colloidal silica is prepared by a sol-gel method, Werner Stober et al; J. Colloid and Interface S
ci., 26, 62-69 (1968), Rickey D. Badley et al; Lang.
muir 6, 792-801 (1990), Journal of the Society of Color Materials, 61 [9] 488-493
(1988).

Commercially available colloidal silica is available from Nissan Chemical Co., Ltd. under the trade name Snowtex-XL (average particle size 40 to 6).
0 nm), Snowtex-YL (average particle size 50-80)
nm), Snowtex-ZL (average particle size 70-100)
nm), PST-2 (average particle diameter 21 nm), Snowtex 20 (average particle diameter 10 to 20 nm, SiO ₂ / Na ₂ O)
> 57), Snowtex 30 (average particle size 10-20 n)
m, SiO ₂ / Na ₂ O> 50), Snowtex C (average particle size 10-20 nm, SiO ₂ / Na ₂ O> 100),
Snowtex O (average particle size 10-20 nm, SiO ₂
/ Na ₂ O> 500), Snowtex 50 (average particle size 20-30 nm), etc., and Adelaite AT-40 (average particle size 10-2
0 nm, solid content 40% by weight), Adelite AT-50
(Average particle diameter: 20 to 30 nm, solid content: 50% by weight) etc. (Note that SiO ₂ / Na ₂ O indicates the content ratio by weight of silicon dioxide and sodium hydroxide (converted to Na ₂ O), and It is described in). When a commercial product is used, Adelite AT-40, AT-50, Snowtex 40, 50 and the like are preferable.

The colloidal silica is mainly composed of silicon dioxide, and may contain alumina, sodium aluminate and the like as minor components. Further, the colloidal silica may contain an inorganic base (such as sodium hydroxide, potassium hydroxide, lithium hydroxide, or ammonia) or an organic base (such as tetramethylammonium) as a stabilizer.

Examples of the inorganic pigments include white pigments (eg, zinc oxide, lithopone, titanium oxide, etc.) and yellow pigments (eg, chrome yellow, nickel titanium yellow, iron oxide yellow,
Red pigments (eg, iron oxide red, red lead oxide, molybdenum red, etc.), orange pigments (eg,
Molybdate orange), green pigments (eg, chrome green, chromium oxide, etc.), blue pigments (eg, dark blue, ultramarine, cobalt blue), purple pigments (eg, manganese violet, etc.), black pigments (eg, channel black, Carbon black such as furnace black, iron oxide black, etc.).

The extender includes, for example, silica, calcium carbonate, barium sulfate, aluminum hydroxide, aluminum silicate (eg, kaolin clay, calcined clay),
Mica, magnesium silicate (eg, talc), alumina, bentonite, magnesium oxide, and the like.

[Organic core particles] As the organic core particles, organic pigments, organic polymer particles (for example, silicone resin, polymethyl methacrylate resin, melamine resin, crosslinked styrene resin, etc.) can be used.

Examples of the organic pigment include azo pigments (for example, yellow pigments such as Hansa Yellow, Benzidine Yellow, Vulcan Fast Yellow, and Permanent Yellow; orange pigments such as pyrazolone orange, Vulcan Orange, and Permanent Orange; toluidine red, permanent red, and brilliant Fast scarlet, red pigments such as Vulcan Fast Red, Pyrazolone Red, Watch Young Red, Resource Red, Lake Red, Brilliant Carmine, Lake Bordeaux, etc., phthalocyanine pigments (eg, blue pigments such as phthalocyanine blue, fast sky blue, phthalocyanine) Green pigments such as green), lake pigments (eg, red pigments such as rhodamine lake, methyl violet lake, Victoria Pure) Blue pigments such as Rureki, green pigments such as final yellow green), and the like. In addition, organic pigments such as quinacridone-based, perylene-based, isoindolinone-based, dioxazine-based, and sulene-based pigments may be used.

These core particles may be used alone or in combination of two or more. In coating agents such as paints, colloidal silica and pigments (inorganic or organic pigments) are usually used as core particles.

The average particle diameter of the core particles is 5 μm or less (for example, 5 nm to 3 μm), preferably 10 nm to 3 μm.
μm, more preferably in the range of about 10 nm to 1.5 μm. When the core particles are colloidal silica, the average particle size is 5 nm to 1 μm (for example, 5 to 5 μm).
00 nm), preferably 10 to 100 nm (for example, 1
0 to 80 nm), and more preferably about 10 to 50 nm. In the case of carbon black, the average particle diameter is 10 to 300 nm, preferably 20 to 100 n.
m, more preferably about 30 to 80 nm.

Further, these core particles may be subjected to a surface treatment, if necessary.

[Nonionic surfactant] When the temperature of the dispersion containing the core particles and the nonionic surfactant is raised to a temperature higher than the cloud point, the nonionic surfactant is aggregated or aggregated and irreversibly deposited on the surface of the core particles. The colloidal fine particles generated
Even at temperatures below the cloud point, dispersion stability is greatly improved.

In the present invention, the cloud point of a nonionic surfactant is defined as the temperature at which a core particle is dispersed in a dispersion medium (for example, an aqueous medium such as water) in the presence of the nonionic surfactant. It means the temperature at which white turbidity occurs in the dispersion during the process. The cloud point can be measured under the condition of a dispersion system because it is affected by the concentration of the nonionic surfactant, the electrolyte, and the like. The cloud point of the nonionic surfactant is, for example, from 0 to 80.
° C, preferably 10 to 70 ° C (for example, 30 to 70 ° C).
° C), more preferably 20 to 60 ° C (for example, 40 to
60 ° C), usually at room temperature (about 15-30 ° C)
Higher than.

Examples of nonionic surfactants (dispersants or dispersion stabilizers) include proteins (gelatin, colloidal albumin, casein, lecithin, etc.), sugar derivatives (agar, starch derivatives, etc.), cellulose derivatives (hydroxymethylcellulose, etc.). ), Esters of polyhydric alcohols [ethylene glycol monofatty acid esters (for example,
Monoglycol ester of oleic acid, monoglycol ester of stearic acid, etc.), polyethylene glycol monofatty acid ester, propylene glycol monofatty acid ester, glycerin monofatty acid ester (for example,
Monoglyceride, stearic acid, etc.), glycerin difatty acid ester, sucrose fatty acid ester, sorbitan fatty acid ester (trade name span) etc.), synthetic hydrophilic polymer,
For example, polyvinyl alcohol, polyvinyl alcohol modified with a terminal long-chain alkyl group, vinyl polymer [at least one ethylenically unsaturated such as hydroxyalkyl (meth) acrylate, alkyl vinyl ether, vinyl acetate, (meth) acrylamide, diacetone acrylamide, etc. Or copolymer containing a monomer having a group as a constituent element], polyoxyalkylene (polyoxyethylene, polyoxypropylene) or a derivative thereof [polyoxyethylene alkyl ether, polyoxyethylene alkylaryl ether, the fatty acid ester] Alkylene oxide adducts (for example, polyoxyethylene glycerin fatty acid ester, polyoxyethylene sucrose fatty acid ester, polyoxyethylene sorbitan fatty acid ester (trade name Twi) ), Etc.)].
As the dispersant, a graft polymer, a block polymer or a macromer in which an anchor group and a dispersion stabilizing group are separated may be used. These nonionic surfactants can be used alone or in combination of two or more.

The nonionic surfactant may have a polymerizable unsaturated bond (for example, an ethylenically unsaturated group such as vinyl, isopropenyl and (meth) acryloyl).
When a nonionic surfactant having a polymerizable unsaturated bond is used, the nonionic surfactant deposited on the surface of the core particles can be polymerized with a vinyl monomer described below.

Preferred nonionic surfactants include surfactants having polyoxyethylene units, for example, polyoxyethylene alkyl ether [for example, polyoxyethylene lauryl ether (Emulgen 1 manufactured by Kao Corporation)
08, cloud point 40 ° C), polyoxyethylene stearyl ether (manufactured by Kao Corporation, Emulgen 409P, cloud point 55)
C), polyoxyethylene C _6-20 alkyl ether], polyoxyethylene alkyl phenyl ether [eg, polyoxyethylene octyl phenyl ether,
Polyoxyethylene lauryl phenyl ether, polyoxyethylene nonyl phenyl ether (manufactured by Kao Corporation,
Polyoxyethylene C _6-20 alkyl phenyl ether such as emulgen 909, cloud point 40 ° C.), polyoxyethylene sucrose C _12-20 fatty acid ester, polyoxyethylene sorbitan C _12-20 fatty acid ester, polyoxyalkylene block Copolymers [for example, polyoxyethylene-polyoxypropylene block copolymers (Pluronic L61, manufactured by Asahi Denka Kogyo Co., Ltd., cloud point 24 ° C., Pluronic L-64, cloud point 58 ° C.)], allyl groups, etc. Polyoxyethylene C _6-20 alkylphenyl ether having at least one ethylenically unsaturated group (polymerizable unsaturated group) [for example, 1-allyloxymethyl-2-nonylphenyloxyethanol ethylene oxide adduct (Asahi Denka Industrial Co., Ltd., Adecaria Soap NE-1
0, cloud point 40 ° C.).

The hydrophilic-lipophilic balance (HLB) of the nonionic surfactant can be selected in a wide range, for example, about 1 to 30, preferably about 3 to 25, and more preferably about 5 to 20.

The nonionic surfactant is used in an amount of 0.01 to 10 parts by weight (for example, 0.1 to 10 parts by weight), preferably 0.1 to 10 parts by weight, based on 100 parts by weight of core particles in terms of solid content.
It is about 1 to 5 parts by weight (for example, 0.5 to 3 parts by weight), and more preferably about 0.3 to 5 parts by weight.

The colloidal fine particles of the present invention have excellent dispersion stability even when the core particle concentration is high, and can greatly improve the dispersion stability and storage stability even at a temperature below the cloud point. Furthermore, the compound has high miscibility with a binder described below, and desired properties can be imparted to the coating film by selecting the binder according to the application.

When an acid is added to the dispersion containing the core particles and the nonionic surfactant, a reversible change in the sol-gel state occurs by adjusting the temperature of the dispersion or adding an alkali. For example, gelling occurs when an acid is added below the cloud point of a nonionic surfactant. Then, when the temperature of the dispersion system is raised to the cloud point or higher, a fluid liquid is generated and sol is formed. Further, when the temperature of the dispersion is cooled below the cloud point, it gels again. On the other hand, in a system containing either a core particle or a nonionic surfactant, the above-described reversible sol-gel change does not occur. By utilizing such a reversible change in the sol-gel state, the vinyl monomer can be polymerized in a sol state, and the storage stability can be enhanced depending on the gel state.

The acid may be an inorganic acid (eg, hydrochloric acid,
Phosphoric acid, etc.), and organic acids (for example, formic acid, acetic acid, oxalic acid, (meth) acrylic acid, etc.). Examples of the alkali include inorganic alkalis (eg, hydroxides of alkali metals such as sodium hydroxide and potassium hydroxide, alkali metal carbonates, alkali metal bicarbonates,
Ammonia, etc.) and organic alkalis (eg, alkylamines such as methylamine and ethylamine). When (meth) acrylic acid or the like is used as the acid, copolymerization with a vinyl monomer described below is possible, and the dispersion can be stabilized.

The acid is added in an amount of 0.1 to 10 parts by weight, preferably 0.3 to 10 parts by weight, per 100 parts by weight of the colloidal fine particles.
8 parts by weight, more preferably about 0.5 to 5 parts by weight. The amount of the alkali added is about 0.8 to 1.2 equivalents to the acid.

[Vinyl Polymer] In the present invention, the nonionic surfactant and the core particle dispersion are mixed at a temperature lower than the cloud point, and then the temperature is raised to a temperature higher than the cloud point to collect or mix the nonionic surfactant. By aggregating and depositing on the core particle surface,
A site for the polymerization of vinyl monomers can be provided. Therefore, in the presence of non-ionic surfactant deposited fine particles,
By polymerizing the vinyl monomer, the vinyl polymer may be bonded to the core particle surface directly or via a nonionic surfactant.

The vinyl polymer can be formed from a conventional polymerizable monomer, and may be a homopolymer or a copolymer. The monomer (vinyl monomer) forming the vinyl polymer includes a radical polymerizable monomer having at least one ethylenically unsaturated group, for example, a (meth) acrylic monomer, an aromatic vinyl-based monomer. Monomers and vinyl ester monomers. These monomers can be used alone or in combination of two or more.

As the vinyl monomer, for example, (meth)
Acrylic acid alkyl esters [methyl (meth) acrylate, ethyl (meth) acrylate, n- or i-propyl (meth) acrylate, 2-methyl-2-nitropropyl (meth) acrylate, n-, i-, s- Or t-butyl (meth) acrylate, n- or t-pentyl (meth) acrylate, 3-pentyl (meth) acrylate, 2,2-dimethylbutyl (meth) acrylate, n-hexyl (meth) acrylate, cetyl (meth) A) acrylate, n-octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, 4-methyl-2-propylpentyl (meth) acrylate, n
( _C1-20 alkyl esters of (meth) acrylic acid such as octadecyl (meth) acrylate), cycloalkyl (meth) acrylate [cyclohexyl (meth) acrylate, cyclopentyl (meth) acrylate and the like],
Aralkyl (meth) acrylate [benzyl (meth) acrylate, etc.], polycyclic (meth) acrylate [2-
Isobornyl (meth) acrylate, 2-norbornylmethyl (meth) acrylate, 5-norbornene-2-
Yl-methyl (meth) acrylate, 3-methyl-2-
Norbornylmethyl (meth) acrylate], hydroxyl group-containing (meth) acrylates [hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2,3-dihydroxypropylmethyl-butyl (meth) Methacrylate, etc.), alkoxy or phenoxy group-containing (meth) acrylates [2-methoxyethyl (meth) acrylate,
2-ethoxyethyl (meth) acrylate, 2-methoxymethoxyethyl (meth) acrylate, 3-methoxybutyl (meth) acrylate, ethyl carbitol (meth) acrylate, phenoxyethyl (meth) acrylate, etc.), epoxy group-containing (meth ) Acrylates [glycidyl (meth) acrylate, etc.], halogen-containing (meth) acrylates [2,2,2-trifluoroethyl (meth) acrylate, 2,2,2-
Trifluoroethylethyl (meth) acrylate, tetrafluoropropyl (meth) acrylate, hexafluoropropyl (meth) acrylate, octafluoropentyl (meth) acrylate, heptadecafluorodecyl (meth) acrylate, etc.], (meth) acrylamides [ For example, (meth) acrylamide, N-methyl (meth) acrylamide, Nn-butyl (meth) acrylamide, Ni-propyl (meth) acrylamide, Nt-butyl (meth) acrylamide, N, N-
Dimethyl (meth) acrylamide, 2- (meth) acrylamide-2-methylpropanesulfonic acid, (meth) acrylamidopropyltrimethylammonium chloride, diacetone (meth) acrylamide, (meth) acryloylmorpholine, N-methylol (meth) acrylamide, etc.] , Alkylaminoalkyl (meth) acrylates [dimethylaminoethyl (meth) acrylate etc.], vinyl cyanides [(meth) acrylonitrile etc.], vinyl esters (eg vinyl acetate etc.),
Aromatic vinyl compounds (for example, styrene, p-chlorostyrene, t-butylstyrene, α-methylstyrene, sodium styrenesulfonate, etc.), a carboxyl group-containing monomer or a salt thereof [(meth) acrylic acid, itaconic acid, Maleic acid, fumaric acid or a salt thereof], a sulfonic acid group-containing monomer or a salt thereof [vinyl sulfonic acid, sodium vinyl sulfonate, sodium allyl sulfonate,
Sodium methallyl sulfonate], unsaturated polycarboxylic acid derivatives (esters such as dimethyl maleate, dibutyl maleate and diethyl fumarate, N-substituted maleimides such as N-phenylmaleimide), N-vinyl polyvalent Carboxylic acid imides [such as N-vinyl succinimide], dienes (eg, butadiene, cyclopentadiene, isoprene), and heterocyclic vinyl monomers (N-vinyl pyrrolidone, N-vinyl oxazolidone, 1-vinyl imidazole, 4-vinyl Pyridine, etc.), N-vinylamides (N-vinylformamide, N-vinyl-N-
Methylformamide, N-vinylacetamide, N-vinyl-N-methylacetamide, etc.), halogen-containing vinyl monomers (vinyl chloride, viridene chloride, etc.), vinyl alkyl ethers (eg, methyl vinyl ether, etc.), olefins ( Ethylene, propylene, 1-butene, isobutene, etc.).
These vinyl monomers can be used alone or in combination of two or more.

Preferred vinyl monomers include (meth) acrylic monomers, aromatic vinyl monomers, vinyl ester monomers and the like. In particular, at least a (meth) acrylic monomer is often used.

The vinyl monomer may be used in combination with a polyfunctional vinyl monomer having two or more unsaturated groups. As the polyfunctional vinyl monomer, for example, divinylbenzene, 4,
4′-isopropylidene diphenylene (meth) acrylate, 1,3-butylene di (meth) acrylate,
1,4-cyclohexylene dimethylene (meth) acrylate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, tetramethylene di ( (Meth) acrylate, diisopropylidene glycol di (meth) acrylate, divinyloxymethane, ethylidene di (meth) acrylate, allyl (meth) acrylate, 1,6-di (meth) acrylamidohexane, N, N'-methylenebis (meth) Acrylamide,
N, N- (1,2-dihydroxy) ethylenebis (meth) acrylamide, 2,2-dimethyl-1,3-trimethylenedi (meth) acrylate, phenylethylenedi (meth) acrylate, 2,2,2-trichloroethylidene Di (meth) acrylate, pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, tetramethylolmethanetetra (meth) acrylate, 1,3,5-tri (meth) acryloylhexahydro-s-triazine, Screw (meta)
Acrylamide acetic acid, ethylidine tri (meth) methacrylate, propylidine tri (meth) acrylate, vinyl allyl oxyacetate and the like can be mentioned. These polyfunctional vinyl monomers can be used alone or in combination of two or more. Among these polyfunctional vinyl monomers, divinylbenzene and monomers having two or more (meth) acryloyl groups (such as ethylene glycol di (meth) acrylate) are generally used.

The polymerization temperature of the vinyl monomer is set to a temperature exceeding the cloud point of the nonionic surfactant, for example, 20%, in order to effectively deposit the nonionic surfactant on the core particle surface and polymerize the vinyl monomer. ~ 110 ° C, preferably 30-100
° C, more preferably 60-100 ° C, especially 70-90 ° C.
It is about ° C.

The vinyl monomer can be selected according to the properties required for the coating film (film forming property, glass transition temperature, etc.), and is usually -30 to 80 ° C., preferably −30 to 80 ° C. A vinyl polymer is formed at a temperature of 20 ° C to 50 ° C, particularly about 0 to 50 ° C. In addition, a vinyl monomer having a reactive group such as a hydroxyl group, a carboxyl group, an acid anhydride group, or a glycidyl group may be used to form a crosslinking system.

The ratio of the vinyl monomer (and thus the vinyl polymer) to the core particles is, for example, less than 20 parts by weight of the vinyl monomer per 100 parts by weight of the core particles (for example, more than 0 and less than 20). Preferably, it is about 2 to 18 parts by weight, more preferably about 3 to 15 parts by weight (for example, about 5 to 10 parts by weight).

The colloidal fine particles of the present invention can effectively modify the surface of the core particles with a small amount of a vinyl polymer, exhibit high dispersion stability, and greatly improve the affinity with a binder described later. Further, since the ratio of the vinyl monomer is small, desired functions and characteristics can be easily imparted to the coating film by combining with various binders.

[Colloidal Fine Particles] The average particle diameter of the colloidal fine particles composed of the core particles and the nonionic surfactant substantially corresponds to the average particle diameter of the core particles.
5 μm or less (eg, 5 nm to 3 μm), preferably 1 μm
0 nm to 3 μm, more preferably 10 nm to 1.5 μm
It can be selected from a range of about m. When the core particles are colloidal silica or carbon black, the average particle diameter of the core particles is substantially the same.

The average particle size of the colloidal fine particles to which the vinyl polymer is bonded directly or via a nonionic surfactant is, for example, 5 μm or less (for example, 6 nm to 3.6).
μm), preferably 10 nm to 3 μm (for example, 10 n
m to 2 μm), more preferably 10 nm to 1.5 μm
You can choose from a range of degrees.

The solid content concentration of the colloidal fine particles (colloidal particle dispersion) can be selected according to the use and the like, for example, 10 to 60% by weight, preferably 30 to 55% by weight,
In particular, it is about 40 to 55% by weight.

In the colloidal fine particles, core-shell composite particles having the core particles as a core and a vinyl polymer as a shell may be formed. Also, a mixture of core-shell particles and at least one kind of particles selected from vinyl polymer particles and core particles may be used.

[Production Method of Colloidal Fine Particles] The colloidal fine particles of the present invention are prepared by mixing core particles with a nonionic surfactant (No. 1).
Of a nonionic surfactant) can be prepared by adjusting the temperature of the dispersion to a cloud point or higher. In particular, after mixing the first nonionic surfactant and the core particles at a temperature lower than the cloud point, the temperature is raised to a temperature equal to or higher than the cloud point, and the first nonionic surfactant is aggregated or aggregated, and the surface of the core particle is It can be manufactured by depositing on Further, in a system in which the first nonionic surfactant is deposited on the core particle surface, by polymerizing the vinyl monomer, it is possible to obtain composite particles in which the vinyl polymer is effectively bonded to the core particle surface. .

In the above-mentioned dispersion system, the core particles become hydrophobic as the polymerization of the vinyl monomer progresses, and the dispersion stability may be reduced to cause agglomeration and gelation. Therefore, a second nonionic surfactant may be added to the reaction system in order to stabilize the dispersion of the hydrophobicized core particles. The second nonionic surfactant may be added at the beginning of mixing, and when the temperature is raised, at the beginning of polymerization,
Alternatively, it may be added after polymerization. Usually, it is preferable to add the second nonionic surfactant after the temperature reaches the cloud point of the first nonionic surfactant or higher.

The cloud point of the second nonionic surfactant is equal to the first nonionic surfactant.
In order to further disperse and stabilize the core particles on which the nonionic surfactant is deposited, the cloud point of the first nonionic surfactant is often exceeded. In particular, in order to stabilize the core particles in the course of the polymerization of the vinyl monomer, the cloud point of the second nonionic surfactant is preferably a temperature exceeding the polymerization temperature. The second nonionic surfactant is oriented on the surface of the hydrophobized core particles, stabilizes the core particles, and, together with the first nonionic surfactant, provides a polymerization site for vinyl monomers.

The amount of the second nonionic surfactant is preferably not more than the critical micelle concentration (CMC) in order to prevent micelles from forming and vinyl polymer single particles. In conversion, it is often 0.01 to 5 parts by weight, preferably 0.1 to 3 parts by weight, more preferably about 0.1 to 2 parts by weight, based on 100 parts by weight of the core particles.

An anionic surfactant generally used for emulsion polymerization may be used for dispersion stabilization. In order to effectively deposit the first nonionic surfactant on the core particle surface, it is preferable to add the anionic surfactant after depositing the first nonionic surfactant on the core particle surface. For example, the anionic surfactant may be added after the nonionic surfactant is uniformly deposited on the core particles or after the vinyl monomer has been polymerized. As described above, the core particles are usually negatively charged in the aqueous dispersion, and therefore it is expected that the adsorption efficiency with the anionic surfactant is low, but the anionic surfactant having a negative charge May form micelles independently with respect to negatively charged nuclear particles. Therefore, if an anionic surfactant is added at the beginning of mixing, a large number of polymer-only particles may be generated.

In the present invention, the vinyl monomer can be polymerized in the above-mentioned dispersion system. A preferred polymerization method is an emulsion polymerization method in which a vinyl monomer is polymerized in the dispersion system. In the emulsion polymerization method, a method in which a vinyl monomer is continuously or stepwise charged into a reaction system is preferable. When monomers are charged into a system in which core particles are dispersed in the presence of a nonionic surfactant, the possibility of forming core-shell composite particles may be reduced. This is presumably because the deposited nonionic surfactant was dissolved in the monomer oil droplets, and the amount of nonionic surfactant deposited on the core particle surface was reduced. After the stable particles are generated as a seed, the vinyl monomer may be charged at once. Also, when adding a monomer to the reaction system,
The composition of the monomers may be the same or may vary.

As the polymerization initiator, a peroxide (for example,
Hydrogen peroxide, etc., persulfates (eg, potassium persulfate, ammonium persulfate), aqueous azo compounds and redox polymerization initiators can be used.

In the polymerization, a chain transfer agent such as an organic peroxide, an organic azo compound, a halogenated hydrocarbon (such as carbon tetrachloride), and a mercaptan compound, which are soluble in a vinyl monomer, are used to adjust the molecular weight of the polymer. And thiols. The amount of the chain transfer agent used is, for example, 5% by weight or less based on the vinyl monomer.

If necessary, in order to enhance the dispersion stability of the core particles, a pH adjuster (eg, acid (sulfuric acid, hydrochloric acid, etc.), ammonia, amine, etc.) may be added to the colloidal fine particles after the polymerization process or after the completion of the reaction. May be added. The pH of the polymerization type or colloidal fine particles may be adjusted to, for example, about pH 7 to 9 (for example, 7.5 to 8.5).

In the present invention, the ratio of core-shell composite particles / vinyl polymer particles / inorganic or organic particles can be adjusted by adjusting the cloud point, critical micelle concentration (CMC) or the amount of nonionic surfactant used in combination. Can be arbitrarily controlled.

That is, in a system in which core particles are dispersed,
When the vinyl monomer is polymerized at a temperature equal to or higher than the cloud point of the nonionic surfactant, it is possible to obtain at least colloidal fine particles mainly composed of composite particles having a core-shell structure. Furthermore, when the vinyl monomer is polymerized at a concentration of the nonionic surfactant (CMC) lower than the critical micelle concentration (CMC), the nonionic surfactant can be effectively deposited on the core particles,
Composite particles having a core-shell structure can be obtained. On the other hand, when the concentration of the nonionic surfactant (b) is equal to or higher than the critical micelle concentration, micelles may be formed as a polymerization site for vinyl monomers, and vinyl polymer particles may be formed.

Further, the amount of the nonionic surfactant used is
When the amount is less than the saturated adsorption amount with respect to the core particles (1), ordinary inorganic or organic particles may be generated. When the amount is equal to or more than the saturated adsorption amount (2), at least the composite particles having a core-shell structure are mainly used. Aqueous dispersion can be obtained.

In the present specification, the critical micelle concentration (CMC) means a concentration at which micelles are formed in an aqueous phase when a nonionic surfactant is added in the presence of core particles. The critical micelle concentration varies depending on the content of the nuclear particles, the electrolyte concentration, and the like.From the relationship between the surfactant concentration and the surface tension, the concentration at which the surface tension becomes a minimum value is used as an index of the apparent critical micelle concentration. be able to. For example, when these components are present, the critical micelle concentration of the nonionic surfactant becomes larger than when no core particles or electrolyte are present. The saturated adsorption amount can be measured in advance by a conventional method. In the case of a core particle having an average particle size of 50 nm or less, the amount of the core particle is 0.1 to 100 parts by weight in terms of solid content.
It is often about 5 to 5 parts by weight (for example, 1 to 2 parts by weight). [Coating composition] The colloidal fine particles obtained by the above method have a high core particle concentration (for example,
50% by weight), and has excellent storage stability, dispersion stability, stain resistance, heat resistance and the like. Further, since the colloidal fine particles of the present invention are also excellent in miscibility with polymers and the like, even when combined with a binder, the coating composition has excellent film-forming properties and storage stability without deteriorating its properties. You can get things. The obtained coating composition can achieve both the characteristics of the core particles and the characteristics of the binder at a high level, and can easily impart desired characteristics by selecting the binder according to the application. Therefore, the coating composition of the present invention is useful as a film forming material (coating agent).

The binder is not particularly limited as long as it has a film-forming property, and may be a water-soluble polymer.
It may be a water-dispersible polymer.

Examples of the water-soluble polymer include cellulose derivatives (eg, cellulose ethers such as methylcellulose, ethylcellulose, hydroxyethylcellulose and carboxymethylcellulose), vinyl alcohol-based polymers (eg, polyvinyl alcohol, ethylene-vinyl alcohol copolymer), and the like. Polyalkylene oxide (polyethylene oxide, ethylene oxide-propylene oxide block copolymer, etc.), a polymer having a carboxyl group or a sulfonic acid group or a salt thereof [acrylic polymer (poly (meth) acrylic acid or a salt thereof, methacrylic acid) Methyl- (meth) acrylic acid copolymer, acrylic acid-polyvinyl alcohol copolymer, styrene-maleic anhydride copolymer, styrene- (meth) acrylic acid copolymer, police Ren sulfonic acid)], vinyl ether-based polymer (polyvinyl methyl ether, polyvinyl alkyl ethers, such as polyvinyl isobutyl ether, methyl vinyl ether - maleic anhydride copolymer), a nitrogen-containing polymer (e.g., polyethylene imine,
Polyacrylamide, polyvinylpyrrolidone, etc.). Examples of the salt include an ammonium salt, an amine salt (eg, an alkylamine such as triethylamine, an alkanolamine, and morpholine), and an alkali metal salt (eg, sodium).

Examples of the water-dispersible polymer include acrylic resin emulsion, vinyl acetate polymer emulsion (polyvinyl acetate, vinyl acetate-methyl acrylate copolymer, ethylene-vinyl acetate copolymer, etc.), styrene Polymers (eg, polystyrene, styrene-methyl (meth) acrylate copolymer, styrene- (meth) acrylate- (meth) acrylic acid copolymer), polyester resins, polyamide resins, polycarbonate resins , Thermoplastic resin such as thermoplastic polyurethane, polyurethane resin, epoxy resin (glycidyl ether type epoxy resin such as bisphenol epoxy resin), vinyl ester polymer (reaction product of epoxy resin and (meth) acrylic acid) ), Amino resin,
A thermosetting resin such as a silicone resin is exemplified.

Examples of the acrylic resin emulsion include homo- or copolymers of acrylic monomers. Examples of the acrylic monomer include (meth) acrylic acid; methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, and t (meth) acrylate. C- (meth) acrylates such as butyl, hexyl (meth) acrylate
_1-10 alkyl ester; C _3-12 cycloalkyl (meth) acrylate such as cyclohexyl (meth) acrylate; aryl (meth) acrylate such as phenyl (meth) acrylate; benzyl (meth) acrylate Aralkyl (meth) acrylate such as; 2
Hydroxy C such as -hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate
_2-6 alkyl (meth) acrylate); alkylamino-alkyl (meth) acrylates such as dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, and diethylaminopropyl (meth) acrylate; (meth) acrylamide, N-methyl (Meth) acrylamide such as (meth) acrylamide, methylol (meth) acrylamide and alkoxymethyl (meth) acrylamide or derivatives thereof; epoxy group-containing (meth) such as glycidyl (meth) acrylate
Acrylate; (meth) acrylonitrile and the like. The acrylic monomer may be used in combination with a copolymerizable monomer. Examples of the copolymerizable monomer include an aromatic vinyl monomer (for example, styrene, α-methylstyrene, pt-butylstyrene, and vinyl toluene); a fatty acid vinyl ester monomer (for example, vinyl acetate) , Vinyl propionate, etc.); unsaturated polycarboxylic acids (eg, maleic anhydride, maleic acid, fumaric acid,
Olefinic monomers (eg, ethylene, itaconic acid, etc.) or unsaturated polycarboxylic acid derivatives (eg, esters such as dimethyl maleate and diethyl fumarate, N-substituted maleimides such as N-phenylmaleimide); Propylene and the like).

These binders may be used alone or in combination of two or more. The binder is usually used in the form of an emulsion. Preferred examples of the binder include an epoxy resin emulsion, a urethane resin emulsion, and an acrylic resin emulsion.

The ratio of the colloidal fine particles to the total amount of the vinyl polymer and the binder is 50 to 5000 in terms of solid content, based on 100 parts by weight of the colloidal fine particles.
Parts by weight, preferably 80 to 3000 parts by weight, more preferably 90 to 1000 parts by weight (for example, 100 to 500 parts by weight).
Parts by weight).

In the coating composition of the present invention, various additives usually used, such as dispersants, wetting agents, thickeners, plasticizers, surface conditioners, defoamers, viscosity adjusters, flame retardants, Antistatic agents, water-soluble organic solvents and the like can be used. In addition, the coating composition may contain a pigment as needed. As the above-mentioned pigment, the above-mentioned inorganic or organic pigments (for example, coloring pigments such as titanium dioxide and phthalocyanine blue, extender pigments and the like, and aluminum powder and glittering agents such as mica flakes may be used. Good pigment concentration in coating composition (PWC)
Is usually 1 to 70% by weight, preferably 10 to 65% by weight, more preferably 20 to 60% by weight in terms of solid content.
It is about. If the solid content is less than 1% by weight, the concealing property decreases, and if it exceeds 70% by weight, the gloss of the coating film decreases,
Viscosity increases, and water resistance and mechanical strength tend to decrease.

The coating composition of the present invention may contain a crosslinking agent or a curing agent (for example, a melamine-based crosslinking agent,
(A polyisocyanate, an epoxy compound, etc.), a crosslinking or curing aid, and the like. When the coating composition of the present invention is applied to a substrate by a conventional method and dried or cured, a coating film having high durability can be formed.

[0070]

According to the present invention, since the nonionic surfactant is aggregated and deposited on the surface of the core particles, the dispersion stability and the storage stability are high even if the solid content is high. Further, the coating composition of the present invention has high film-forming properties and storage stability, and can form a coating film having excellent stain resistance and weather resistance over a long period of time. Furthermore, desired properties can be imparted to the coating film by selecting the binder according to the application.

[0071]

The present invention will be described below in more detail with reference to Examples, but the present invention is not limited to these Examples.

Synthesis Example 1 Colloidal silica (Adelite AT-50, manufactured by Asahi Denka Kogyo KK) was placed in a 1000 mL four-neck glass flask equipped with a stirrer, thermometer, dropping funnel and reflux condenser.
Solid content 50% by weight, average particle size 20-30nm) 200g
And a nonionic surfactant (Adekaria Soap NE-10, manufactured by Asahi Denka Kogyo Co., Ltd., cloud point 40 ° C.
After dropping 3.0 g of the solution with a solid content of 100% by weight while stirring, the temperature was raised to 60 to 70 ° C. Thereafter, the mixture was cooled to obtain stabilized colloidal fine particles (particle dispersion).

Comparative Synthesis Example 1 A 1000 mL glass four-necked flask equipped with a stirrer, a thermometer, a dropping funnel, and a reflux condenser was charged with colloidal silica (Adelite AT-50, manufactured by Asahi Denka Kogyo KK).
Solid content 50% by weight, average particle size 20-30nm) 200g
Nonionic surfactant (Kao Corporation)
EMULGEN 840S, solid content 70% by weight, cloud point 10
(0 ° C. or higher) 4.2 g was added dropwise with stirring to obtain colloidal fine particles.

Example 1 Acrylic emulsion (manufactured by Mizutani Paint Co., Ltd., G-
25, a solid content of 50% by weight) and 100 g of the colloidal fine particles (solid content of 50.5% by weight) of Synthesis Example 1 were mixed to obtain a coating composition.

Comparative Example 1 Acrylic emulsion (manufactured by Mizutani Paint Co., Ltd., G-
25, a solid content of 50% by weight) was mixed with 100 g of the colloidal fine particles (solid content of 50% by weight) of Comparative Synthesis Example 1 to obtain a coating composition.

Comparative Example 2 Acrylic emulsion (manufactured by Mizutani Paint Co., Ltd., G-
100 g of colloidal silica (Adelite AT-50, manufactured by Asahi Denka Kogyo KK, solid content of 50 wt%, average particle diameter of 20 to 30 nm) is mixed with 100 g of 25, solid content of 50 wt% to obtain a coating composition. Was.

The storage stability of the coating compositions of Example 1 and Comparative Examples 1 and 2 was evaluated according to the following criteria. While the storage stability of Example 1 was good, Comparative Example 1
In No. 2, the viscosity increased and the gel was formed. Table 1 shows the results.

[Storage stability]…: not thickened at all △: thickened ×: gelled (produces aggregates)

[0079]

[Table 1]

Synthesis Example 2 Colloidal silica (Adelite AT-50, manufactured by Asahi Denka Kogyo KK, solid content 50%) was placed in a 1000 mL four-neck glass flask equipped with a stirrer, a thermometer, a dropping funnel and a reflux condenser. Weight%, average particle size of 20 to 30 nm), 200 g of nonionic surfactant (made by Asahi Denka Kogyo Co., Ltd., Adekalia Soap NE-10, cloud point of 40 ° C.) under a nitrogen stream.
(Reactivity) 3.0 g was added dropwise with stirring, and then 70 g
The temperature was raised to ° C. 0.5 g of ammonium persulfate was added,
5 g of a vinyl monomer mixture of methyl methacrylate (MMA) / n-butyl acrylate (n-BA) = 50/50 (weight ratio) was dropped for 10 minutes, left to stand for 2 hours to polymerize,
Thereafter, the mixture was cooled to obtain stabilized colloidal fine particles.

Synthesis Example 3 Colloidal silica (manufactured by Nissan Chemical Industries, Inc., Snowtex 50, solid content 50% by weight) was placed in a 1000 mL four-neck glass flask equipped with a stirrer, thermometer, dropping funnel and reflux condenser. , An average particle size of 20 to 30 nm) and a first nonionic surfactant (made by Asahi Denka Kogyo KK, Adecaria Soap NE-10, cloud point 40) under a nitrogen stream.
° C, reactive), second nonionic surfactant (Kao Corporation)
EMULGEN 840S, solid content 70% by weight, cloud point 10
(0 ° C. or higher) were added with stirring in an amount of 6.0 g and 3.0 g, respectively, and then the temperature was raised to 70 ° C. Add 0.5 g of ammonium persulfate and add methyl methacrylate (MMA)
/ N-butyl acrylate (n-BA) / styrene (S
10 g of a vinyl monomer mixture (t) = 30/50/20 (weight ratio) was added dropwise for 10 minutes, left to polymerize for 2 hours, and then cooled to obtain stabilized colloidal fine particles.

Synthesis Examples 4 and 5 Using the components shown in Table 2, stabilized colloidal fine particles were obtained in the same manner as in Synthesis Example 2.

Synthesis Example 6 A 500 mL steel beaker was charged with 240 g of distilled water and 7.2 g of nonionic surfactant (Adekaria Soap NE-10, manufactured by Asahi Denka Kogyo KK, cloud point 40 ° C., reactivity). 0.48 g of an antifoaming agent (manufactured by San Nopco Co., Ltd., Nopco 8034, solid content 100% by weight) was added, and 1000 rpm
m while stirring with titanium dioxide (Ishihara Sangyo Co., Ltd., C
(R-90, average particle size 220-280 nm) While gradually adding 240 g, 30 minutes after adding all, for 15 minutes.
Stirring was performed at 00 rpm to obtain a white mill base.

406.4 g of this white mill base
Was placed in a 1000 mL four-necked flask equipped with a stirrer, a thermometer, a dropping funnel, and a reflux condenser, and heated to 70 ° C. under a nitrogen stream. 0.5 g of ammonium persulfate was added, 10 g of a vinyl monomer mixture of MMA / n-BA = 50/50 (weight ratio) was dropped for 10 minutes, left to polymerize for 2 hours, and then cooled to obtain a stabilized colloid. Fine particles were obtained.

Synthesis Example 7 In place of titanium oxide CR-90 in Synthesis Example 6, calcium carbonate (manufactured by Maruo Calcium Co., Ltd., Luminous, particle size: 70 to 90%) was used.
(90 nm) to obtain stabilized colloidal fine particles in the same manner as in Synthesis Example 6.

Synthesis Example 8 A 500 mL steel beaker was charged with 180 g of distilled water and 4.8 g of nonionic surfactant (Adekaria Soap NE-10, manufactured by Asahi Denka Kogyo KK, cloud point 40 ° C., reactivity), 3.0 g of wetting agent (manufactured by San Nopco Co., Ltd., Modicol L, nonionic surfactant, solid content 100% by weight), antifoaming agent (manufactured by San Nopco Co., Nopco 8034, solid content 1
Quinacridone red (manufactured by Dainichi Seika Kogyo Co., Ltd.) while stirring at 1000 rpm.
Chromofine Red 6820, average particle size 150-20
(0 nm) while gradually adding 120 g, and further adding 200 g of glass beads, followed by stirring at 3000 rpm for 20 minutes.

Of the dispersion (excluding glass beads) obtained above, 205.4 g was placed in a 1000 mL glass four-necked flask equipped with a stirrer, thermometer, dropping funnel, and reflux condenser. The temperature was raised to 70 ° C. in an air stream.
Add 0.5 g of ammonium persulfate and add MMA / n-B
A = 50/50 (weight ratio) vinyl monomer mixture 5.0
g was dropped in 10 minutes, and left to polymerize for 2 hours, and then cooled to obtain stabilized colloidal fine particles.

Table 2 shows the proportion of each component in Synthesis Examples 2 to 8.

[0089]

[Table 2]

Even when Synthesis Examples 6, 7 and 8 were allowed to stand for 10 days, there was no precipitate and no aggregation of the pigment occurred.

Comparative Synthesis Example 3 A 1000 mL glass four-necked flask equipped with a stirrer, a thermometer, a dropping funnel, and a reflux condenser was charged with colloidal silica (Adelite AT-50, manufactured by Asahi Denka Kogyo KK).
Solid content 50% by weight, average particle size 20-30nm) 200g
Nonionic surfactant (Kao Corporation)
EMULGEN 840S, solid content 70% by weight, cloud point 10
(0 ° C. or higher) 4.2 g was added dropwise while stirring, and then 70 g
The temperature was raised to ° C. 0.5 g of ammonium persulfate was added,
5 g of a vinyl monomer mixture of MMA / n-BA = 50/50 (weight ratio) was added dropwise over 10 minutes, left to polymerize for 2 hours, and then cooled to obtain colloidal fine particles.

Example 2 Acrylic emulsion (manufactured by Mizutani Paint Co., Ltd., G-
25, a solid content of 50% by weight) was mixed with 100 g of the colloidal fine particles of Synthesis Example 2 (a solid content of 52% by weight) to obtain a coating composition.

Example 3 In place of the colloidal fine particles of Synthesis Example 2, the colloidal fine particles of Synthesis Example 6 (solid content: 52% by weight) were used.
A coating composition was obtained in the same manner as in Example 2.

Example 4 In place of the colloidal fine particles of Synthesis Example 2, the colloidal fine particles of Synthesis Example 7 (solid content: 52% by weight) were used.
A coating composition was obtained in the same manner as in Example 2.

Example 5 In place of using the colloidal fine particles of Synthesis Example 8 (solid content: 42% by weight) instead of the colloidal fine particles of Synthesis Example 2,
A coating composition was obtained in the same manner as in Example 2.

Comparative Example 3 Acrylic emulsion (manufactured by Mizutani Paint Co., Ltd., G-
25, a solid content of 50% by weight) was mixed with 100 g of the colloidal fine particles (solid content of 51.5% by weight) of Comparative Synthesis Example 3 to obtain a coating composition.

Comparative Example 4 Acrylic emulsion (manufactured by Mizutani Paint Co., Ltd., G-
100 g of colloidal silica (Adelite AT-50, manufactured by Asahi Denka Kogyo Co., Ltd., solid content of 50% by weight, average particle diameter of 20 to 30 nm) is mixed with 100 g of 25, solid content of 50% by weight to obtain a coating composition. Was.

Comparative Example 5 Acrylic emulsion (manufactured by Mizutani Paint Co., Ltd., G-
25, a solid content of 50% by weight) was used as the coating composition.

The storage stability of the coating compositions of Examples 2 to 4 and Comparative Examples 3 to 5 was evaluated according to the above criteria, and the weather resistance was evaluated according to the following criteria. The results are shown in Table 3. [Weather resistance]…: extremely good with no change in the coating film ○: good with little change in the coating film レ ベ ル: small change in the coating film, no problem in practical use ▲: coating film The change is slightly small, and a level that causes a problem in practical use. ×: The change in the coating film is large, and the practicality is poor.

[0100]

[Table 3]

Comparative Synthesis Example 4 A 1000 mL glass four-necked flask equipped with a stirrer, thermometer, dropping funnel and reflux condenser was charged with colloidal silica (Adelite AT-50, manufactured by Asahi Denka Kogyo KK).
Solid content 50% by weight, average particle size 20-30nm) 200g
And the temperature was raised to 70 ° C. without adding a surfactant.
Add 0.5 g of ammonium persulfate and add MMA / n-B
A = 10 g of vinyl monomer mixture of 50/50 (weight ratio)
Was dropped for 10 minutes and left for 60 minutes. During this processing time, a large amount of suspended polymer was generated in the flask.

Comparative Synthesis Example 5 A 1000 mL glass four-necked flask equipped with a stirrer, a thermometer, a dropping funnel, and a reflux condenser was charged with 100 g of distilled water, a nonionic surfactant (Asahi Denka Co., Ltd.) without adding colloidal silica. Industrial Co., Ltd., Adecaria Soap NE-10,
(Cloud point 40 ° C, reactivity) 3.0 g was stirred and heated to 70 ° C. Add 0.5 g of ammonium persulfate and add MMA
10 g of a vinyl monomer mixture of / n-BA = 50/50 (weight ratio) was added dropwise for 10 minutes and left for 60 minutes. During this standing time, the polymer adhered to the flask wall surface, and polymer suspended matter was also generated.

Comparative Synthesis Example 6 A 1000 mL glass four-necked flask equipped with a stirrer, a thermometer, a dropping funnel, and a reflux condenser was charged with colloidal silica (Adelite AT-50, manufactured by Asahi Denka Kogyo KK).
Solid content 50% by weight, average particle size 20-30nm) 200g
And a surfactant (Emulgen 840, manufactured by Kao Corporation)
4.2 g of S, a solid content of 70% by weight and a cloud point of 100 ° C. or higher) were added with stirring under a nitrogen stream, and then the temperature was raised to 70 ° C. 0.5 g of ammonium persulfate was added and MMA /
10 g of a vinyl monomer mixture of n-BA = 50/50 (weight ratio) was added dropwise for 10 minutes and left for 60 minutes. afterwards,
2.1 g of the surfactant 840S was added, and 90 g of the above-mentioned vinyl monomer mixture was dropped at 70 ° C. over 4 hours. After completion of the dropwise addition, the mixture was further kept under stirring at 70 ° C. for 1 hour, and then adjusted to pH 8.5 with 25% by weight aqueous ammonia to obtain colloidal fine particles (dispersion). This dispersion had good film-forming properties.

Further, colloidal silica (Adelite AT-50, manufactured by Asahi Denka Kogyo KK), solid content of 50% by weight,
When 300 g of an average particle size (20 to 30 nm) was added and the reaction was carried out in the same manner, colloidal fine particles (dispersion) were obtained, but no film was formed.

Example 6 Colloidal silica (Adelite A, manufactured by Asahi Denka Kogyo KK)
T-50, solid content 50% by weight, average particle size 20-30n
m) 400 g was added, and a nonionic surfactant (Adekaria Soap NE-10, manufactured by Asahi Denka Kogyo KK, cloud point 40 ° C,
Reactivity) 6.0 g was added with stirring under a nitrogen stream,
The temperature was raised to 70 ° C. 0.5 g of ammonium persulfate was added, 10 g of a vinyl monomer mixture of MMA / n-BA = 50/50 (weight ratio) was added dropwise over 10 minutes, and the mixture was allowed to stand for 60 minutes. Then, a surfactant (Emulgen 8 manufactured by Kao Corporation)
40S, solid content 70% by weight, cloud point 100 ° C or higher) 2.1
g at a temperature of 70 ° C.
g was added dropwise over 4 hours. After completion of the addition, stirring was continued at 70 ° C. for 1 hour. Thereafter, the mixture was cooled and adjusted to pH 8.5 with 25% by weight aqueous ammonia to obtain stabilized colloidal fine particles. The colloidal fine particles had good film-forming properties.

[Addition of Acid] Colloidal silica (Adelite AT-50, manufactured by Asahi Denka Kogyo KK, solid content of 50%) was placed in a 1000 mL glass four-necked flask equipped with a stirrer, thermometer, dropping funnel and reflux condenser. % By weight, average particle size 20
Nonionic surfactant (made by Asahi Denka Kogyo Co., Ltd., Adecaria Soap NE)
3.0 g, cloud point 40 ° C., reactivity) was added with stirring, and then 1 g of acetic acid was added dropwise, resulting in gelation. When heat was applied to this gelled material and the temperature was raised, it became a fluid liquid at 60 ° C. or higher. Further, when the liquid was cooled, the viscosity gradually increased, and the liquid was gelled. When 25% by weight of aqueous ammonia was added to the gelled product, it returned to a liquid state. This state change could be repeated.

The temperature of the acid-added gel was increased to 70 ° C., ammonium persulfate was added, and MMA / n-BA =
5 g of a 50/50 (weight ratio) vinyl monomer mixture was added dropwise to obtain stabilized colloidal fine particles in the same manner as in Synthesis Example 2.

A nonionic activator (Asahi Denka Kogyo KK)
Gelling did not occur even when acetic acid was added to Adecaria Soap NE-10, cloud point 40 ° C, reactivity). In addition, colloidal silica (Adelite AT, manufactured by Asahi Denka Kogyo KK)
-50, solid content 50% by weight, average particle size 20 to 30 nm)
When acetic acid was added to the mixture, gelation occurred, but the addition of alkali did not result in a sol.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C09C 3/10 C09C 3/10 C09D 5/02 C09D 5/02 133/00 133/00 163/00 163 / 00 175/04 175/04 (72) Inventor Yoshiharu Kimura 1126-1, Takakaicho, Omihachiman City, Shiga Prefecture (72) Inventor Masatoshi Miyamoto 425-3, Isemachi, Moriyama City, Shiga Prefecture F-term (reference) 4G072 AA28 DD04 DD05 DD06 GG01 QQ06 TT01 UU07 4J026 AA16 AA45 AB01 AB44 AC00 AC31 BA05 BA27 DB04 FA04 GA01 4J037 AA02 AA08 AA10 AA11 AA15 AA17 AA18 AA19 AA22 AA24 AA27 AA30 CB10 CB30 CC15 CC12 CC12 CC13 CC12 CC13 CC12 CC13 4J038 BA021 CA022 CB002 CC002 CC021 CC022 CD002 CE021 CE051 CF002 CF021 CG001 CG002 CG142 CH032 CK002 CK031 CR002 DA111 DA162 DB001 DD001 DE001 DF011 DG001 DH001 DJ011 DL031 DL032 HA026 HA216 HA286 HA376 HA446 HA456 HA526 HA536 HA546 KA09 KA14 KA20 LA04 MA03 MA08 MA09 MA10 MA12 NA03 NA05 NA24 NA25 NA26

Claims (13)

[Claims] 1. Colloidal fine particles in which nonionic surfactants are aggregated or aggregated and deposited on the surface of inorganic or organic particles. 2. The colloidal fine particles according to claim 1, wherein the inorganic particles are colloidal silica. 3. The colloidal fine particles according to claim 1, wherein the nonionic surfactant has a cloud point of 0 to 80 ° C. 4. The colloidal fine particles according to claim 1, wherein the nonionic surfactant has at least one ethylenically unsaturated group. 5. The content of the nonionic surfactant is 0.04 based on 100 parts by weight of inorganic or organic particles in terms of solid content.
The colloidal fine particles according to claim 1, wherein the amount is 1 to 10 parts by weight. 6. A colloidal fine particle in which a vinyl polymer is bonded to the surface of an inorganic or organic particle directly or via a nonionic surfactant, wherein the ratio of the vinyl polymer to 100 parts by weight of the inorganic or organic particle is The colloidal fine particles according to claim 1, which is less than 20 parts by weight. 7. The method according to claim 6, wherein the vinyl polymer is at least one polymer selected from (meth) acrylic monomers, aromatic vinyl monomers and vinyl ester monomers. Colloidal fine particles. 8. The colloidal fine particles according to claim 1, wherein the average particle size of the inorganic or organic particles is 5 μm or less. 9. A method for producing colloidal fine particles in which the temperature of a dispersion containing inorganic or organic particles and a nonionic surfactant is raised to the cloud point of the nonionic surfactant or higher. 10. In a dispersion in which a nonionic surfactant is deposited on the surface of inorganic or organic particles, less than 20 parts by weight of a vinyl monomer is polymerized with respect to 100 parts by weight of the inorganic or organic particles. The method for producing the colloidal fine particles according to the above. 11. A coating composition comprising the colloidal fine particles according to claim 1 and a binder. 12. The coating composition according to claim 11, wherein the binder is at least one resin emulsion selected from an epoxy resin emulsion, a urethane resin emulsion and an acrylic resin emulsion. 13. The coating composition according to claim 11, wherein the total content of the vinyl polymer and the binder is 50 to 5,000 parts by weight based on 100 parts by weight of the colloidal fine particles in terms of solid content.