JP2003105046A - Aqueous dispersion - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aqueous dispersion which is excellent in storage stability and weather resistance and gives a film excellent in adhesive properties or adhesion to various substrates as well as excellent in water resistance and weather resistance. SOLUTION: The aqueous dispersion comprises a block copolymer comprising an aromatic vinyl polymer block A bonded via a sulfur atom to a polymer block B comprising 2-100 mole% of a vinyl monomer unit bearing at least one functional group selected from the group consisting of a carboxyl group, an acid anhydride group, a hydroxyl group, a sulfonic group, an amino group and an amide group and 98-0 mole% of a unit of another vinyl monomer copolymerizable with the vinyl monomer.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an aqueous dispersion. The aqueous dispersion of the present invention is excellent in storage stability, weather resistance and the like. Further, the aqueous dispersion of the present invention provides a film having excellent adhesiveness and adhesion to various substrates and excellent weather resistance and water resistance.

[0002]

2. Description of the Related Art Amphiphilic polymers having a hydrophobic portion and a hydrophilic portion are applied in a wide range of fields such as paints, inks, adhesives, pressure sensitive adhesives, textile processing, paper processing and various surface treatment agents. The sex is drawing attention. In particular, it has been desired to obtain such an amphiphilic polymer as an aqueous dispersion because of the recent increase in environmental awareness. As a method for producing an aqueous dispersion of an amphipathic polymer, conventionally, a monomer which forms a water-insoluble polymer in the presence of a water-soluble macromonomer is polymerized in water to form a graft polymer. A method, a method of introducing a functional group into a polymer side chain, and reacting with a polymer having a functional group capable of reacting with the functional group at a terminal to synthesize a graft polymer, and then dispersing in water, have been studied. It was
However, in the former case, the production of the macromonomer is expensive, and in the latter case, the grafting efficiency is not sufficiently increased because the macromolecular reaction is utilized, and a stable aqueous dispersion may not be obtained.

As a method of obtaining an aqueous dispersion having excellent dispersion stability, a hydrophilic polymer obtained by polymerizing a water-soluble vinyl monomer in the presence of a specific peroxide and a water-insoluble vinyl-based polymer. A method of block-copolymerizing a monomer in an aqueous medium has been proposed (Japanese Patent Publication No. 62-39162 and Japanese Examined Patent Publication 6).
2-39163, JP-B-62-39602 and JP-B-63-37145). However, according to this method, it is said that the peroxy bond in the hydrophilic polymer is cleaved and the block copolymerization proceeds, and it is difficult to sufficiently control the structure of the block copolymer produced. Therefore, the resulting aqueous dispersion has its own weather resistance, and also in terms of water resistance and weather resistance of a film obtained by drying the aqueous dispersion, adhesion and adhesion to various substrates, and the like. In many cases, the performance is not fully exhibited. Also, in emulsion polymerization, chain transfer to iodine compounds and A
There is known a method of preparing an aqueous dispersion of a styrene-butyl acrylate diblock copolymer, a styrene-ethyl acrylate-styrene triblock copolymer, etc. by using a method called TRP method (European Patent Application Publication). (See Japanese Patent No. 947527). This method is also applicable to the production of an aqueous dispersion of an amphipathic polymer, and is said to be able to control the structure of the resulting polymer, but it is difficult to control the interface in the initial monomer emulsification. It is necessary to use an activator. Therefore, the resulting aqueous dispersion, when used as a coating film, tends to cause bleed-out of the surfactant, reduction in water resistance due to the surfactant, reduction in strength, and adhesion to various substrates. In many cases, the adhesiveness and the like are not sufficient.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned prior art, and is an aqueous dispersion having excellent storage stability and weather resistance, and has excellent adhesiveness to various base materials. An object of the present invention is to provide an aqueous dispersion that gives a film having excellent adhesion and water resistance and weather resistance.

[0005]

According to the present invention, the above-mentioned problems are solved from an aromatic vinyl polymer block A and a carboxyl group, an acid anhydride group, a hydroxyl group, a sulfonic acid group, an amino group and an amide group. 2 to 100 mol% of a vinyl monomer unit having at least one functional group selected from the group consisting of and 98 to 0 mol of another vinyl monomer copolymerizable with the vinyl monomer. % Polymer block B
Is solved by providing an aqueous dispersion of a block copolymer in which is bound via a sulfur atom.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The structure of the block copolymer used in the present invention is such that when the aromatic vinyl polymer block A is represented by A and the polymer block B is represented by B,
Examples thereof include an AB type diblock structure and an ABA type triblock structure, but an AB type diblock structure is preferable.

The polymer block A is a polymer block mainly composed of aromatic vinyl monomer units. Examples of the aromatic vinyl-based monomer unit include styrene and α-
Methylstyrene, o-, m-, p-methylstyrene, t
-Butyl styrene, 2,4,6-trimethyl styrene,
Monofluorostyrene, difluorostyrene, monochlorostyrene, dichlorostyrene, methoxystyrene,
Structural units derived from aromatic vinyl-based monomers such as 1,3-vinylnaphthalene, vinylanthracene, indene and acetonaphthylene are mentioned, but structural units derived from styrene or α-methylstyrene are preferred. The polymer block A can contain 1 type (s) or 2 or more types of such a structural unit.

In the polymer block A, if necessary, structural units derived from a vinyl-based monomer copolymerizable with the above-mentioned aromatic vinyl-based monomer are added to all the structural units of the polymer block A. You may contain in the ratio of 0-50 mol% based on the total number of moles. The content of the vinyl monomer unit is
It is preferably in the range of 0 to 30 mol% based on the total number of moles of all structural units of the polymer block A, and 0 to 2
It is more preferably within the range of 0 mol%.

Examples of vinyl monomers copolymerizable with the above-mentioned aromatic vinyl monomers include (meth) acrylonitrile; methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, Examples thereof include (meth) acrylic acid esters such as dodecyl (meth) acrylate and 2-ethylhexyl (meth) acrylate, with methyl methacrylate and acrylonitrile being preferred. The vinyl-based monomer copolymerizable with the aromatic vinyl-based monomer may be one or two of these.
More than one species can be used.

The vinyl monomer copolymerizable with the aromatic vinyl monomer is a carboxyl group or acid anhydride group such as (meth) acrylic acid, (meth) acrylamide, N-vinyl-2-pyrrolidone. , A structural unit derived from a monomer having a hydroxyl group, a sulfonic acid group, an amino group or an amide group, the content of the structural unit in the polymer block A is It is necessary to be less than 2 mol% and preferably less than 1 mol% based on the total number of moles of structural units.

The polymer block B is a vinyl monomer having at least one functional group selected from the group consisting of a carboxyl group, an acid anhydride group, a hydroxyl group, a sulfonic acid group, an amino group and an amide group (hereinafter, 2 to 100 mol% of a unit of a functional group-containing monomer) and 98 to 0 mol% of a unit of another vinyl monomer copolymerizable with the functional group-containing monomer. It is a united block. The content of the functional group-containing monomer unit in the polymer block B is preferably in the range of 2 to 50 mol%, and 2
Is more preferably within the range of 45 mol%
It is more preferably within the range of 30 mol%.

Examples of the functional group-containing monomer include vinyl monomers having a carboxyl group such as acrylic acid, methacrylic acid, crotonic acid, cinnamic acid, itaconic acid and maleic acid; maleic anhydride and itacone anhydride. Vinyl monomers having acid anhydride groups such as acid, citraconic anhydride, butenyl succinic anhydride, and tetrahydrophthalic anhydride; 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, N-methylol acrylamide, N-methylol methacryl Vinyl-based monomers having a hydroxyl group such as amide and ethylene glycol acrylate; Vinyl-based monomers having a sulfonic acid group such as p-styrenesulfonic acid and its sodium salt, potassium salt; N, N-dimethylethyl acrylate, Substituted with N, N-dimethylethylmethacrylate, etc. A vinyl-based monomer having an amino group; a vinyl-based monomer having an amide group such as acrylamide and methacrylamide, and the like, but a vinyl-based monomer having a carboxyl group and a carboxylic acid anhydride group Vinyl-based monomers are preferable, and acrylic acid, methacrylic acid, and maleic anhydride are more preferable. As the functional group-containing monomer, one kind among these may be used, or two or more kinds may be used in combination.

Other vinyl monomers copolymerizable with the functional group-containing monomer include (meth) acrylonitrile; vinyl esters such as vinyl acetate and vinyl pivalate; methyl (meth) acrylate, ethyl (meth). Acrylate,
Examples thereof include (meth) acrylic acid esters such as butyl (meth) acrylate, dodecyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate, with methyl (meth) acrylate, ethyl (meth) acrylate, and vinyl acetate being preferred.

The number average molecular weight of the polymer block A is 1,
It is preferably in the range of 000 to 15,000,
More preferably, it is in the range of 2,500 to 12,000. The number average molecular weight of the polymer block B is
It is preferably in the range of 2,000 to 30,000, and more preferably in the range of 4,000 to 20,000. The number average molecular weight of the block copolymer is 3,
It is preferably in the range of 000 to 45,000,
More preferably, it is in the range of 6,500 to 30,000. The number average molecular weight referred to in the present specification is a value determined by a gel permeation chromatography (GPC) method based on a standard polystyrene calibration curve.

The ratio of the polymer block A to the polymer block B in the block copolymer is preferably in the range of former / latter = 1/3 to 3/1 by weight ratio, and 1 /
More preferably within the range of 2 to 2/1, and 1 /
More preferably, it is within the range of 1.5 to 1.5 / 1.

The method for producing the block copolymer is not particularly limited, but for example, a polymer having a mercapto group and having a structure corresponding to the polymer block A (hereinafter abbreviated as precursor A). Sometimes) and then forming the polymer block B on the mercapto group of the precursor. According to this method, the target block copolymer can be easily and efficiently produced. In addition, in the precursor A, the mercapto group is preferably present at the molecular end. The precursor A may have one or more mercapto groups. It is also possible to produce a block copolymer by a method of producing a polymer having a mercapto group and having a structure corresponding to the polymer block B, and then forming a polymer block A on the mercapto group of the polymer. It is possible.

The precursor A can be manufactured by various methods. For example, when radical-polymerizing a monomer that constitutes the polymer block A, thio-S-acetic acid, thio-
A method of adding S-benzoic acid, thio-S-propionic acid, thio-S-butyric acid or thio-S-valeric acid to introduce a thioester group at the polymer terminal by a chain transfer reaction, and then treating with an acid or an alkali When polymerizing the monomer constituting the polymer block A by the anionic polymerization method, it can be produced by a method of using ethylene sulfide or the like as a terminating agent. Then, the block copolymer can be produced by a method in which the precursor A is dissolved in an organic solvent such as toluene, and the monomer constituting the polymer block B is added to the solution to carry out radical polymerization. Radical polymerization of the monomers constituting the polymer block B can be carried out according to a conventional method.

In the aqueous dispersion of the present invention, a styrenic polymer may be added to 100 parts by weight of the above block copolymer. The blending amount of the styrene-based polymer is within the range of 1 to 200 parts by weight based on 100 parts by weight of the block copolymer, from the viewpoint of the balance between the storage stability of the aqueous dispersion and the strength of the film obtained from the aqueous dispersion. Is preferable, and more preferably within the range of 10 to 50 parts by weight.

Examples of the styrene-based polymer include polystyrene, syndiotactic polystyrene, styrene-maleic anhydride copolymer, styrene-methyl methacrylate copolymer, styrene-conjugated diene block copolymer or hydrogenation thereof. The thing etc. are mentioned.

The aqueous dispersion of the present invention can be produced by dispersing the above-mentioned block copolymer and the styrenic polymer optionally blended in an aqueous medium. Water is preferred as the aqueous medium, but a mixture of water and an organic solvent miscible with water can also be used. As the organic solvent miscible with water, for example, methanol, ethanol,
Alcohols such as 2-propanol, n-butanol, t-butanol; polyhydric alcohols such as ethylene glycol, diethylene glycol, tetraethylene glycol, polyethylene glycol; 3-methyl-3-methoxybutanol (MMB), 2-methoxyethanol (methyl Cellosolve), 2-ethoxyethanol (ethyl cellosolve), 2-butoxyethanol (butyl cellosolve), mono- or diethers derived from alkylene glycols such as diethylene glycol dimethyl ether, diethylene glycol diethyl ether; carboxylic acids such as acetic acid; ethers such as dioxane and tetrahydrofuran. Ketones such as acetone; Esters such as methyl acetate and ethyl acetate; Polar non-precipitates such as dimethylformamide and dimethylsulfoxide Such as tons of solvents.
The amount of the organic solvent miscible with water is usually 50 parts by weight or less with respect to 100 parts by weight of water.

The mixing ratio of the block copolymer and the aqueous medium in the aqueous dispersion of the present invention is such that the block copolymer is 5 to 5.
The amount is preferably within the range of 95 to 30 parts by weight with respect to 70 parts by weight of the aqueous medium.

When the polymer block B in the block copolymer contains a unit of a vinyl monomer having a carboxyl group, an acid anhydride group or a sulfonic acid group,
It is preferable to use an aqueous medium containing a basic substance from the viewpoint of dispersion stability of the obtained aqueous dispersion.

As the basic substance, ammonia; hydroxylamine, ammonium hydroxide, hydrazine, hydrazine hydrate, (di) methylamine, (di) ethylamine, (di) propylamine, (di) butylamine,
(Di) hexylamine, (di) octylamine, (di)
Ethanolamine, (di) propanolamine, N-methyldiethanolamine, triethylamine, N, N-
Amine compounds such as dimethylethanolamine, N, N-diethylethanolamine, 2-dimethylamino-2-methyl-1-propanol, 2-amino-2-methyl-1-propanol, cyclohexylamine and tetramethylammonium hydroxide; Metal oxides such as sodium oxide, potassium oxide, calcium oxide, strontium oxide, barium oxide; metal hydroxides such as barium hydroxide, sodium hydroxide, potassium hydroxide, calcium hydroxide, strontium hydroxide; sodium hydride Metal hydrides such as potassium hydride and calcium hydride; carbonates such as sodium carbonate, potassium carbonate, sodium hydrogencarbonate, potassium hydrogencarbonate and calcium hydrogencarbonate; acetates such as sodium acetate, potassium acetate and calcium acetate. To be Of these, the ease of availability,
From the viewpoint of stability of the resulting aqueous dispersion, ammonia,
(Di) methylamine, (di) ethylamine, (di) propylamine, (di) butylamine, N-methyldiethanolamine, triethylamine, N, N-dimethylethanolamine, N, N-diethylethanolamine, 2
-Dimethylamino-2-methyl-1-propanol, 2
-Amino-2-methyl-1-propanol, sodium hydroxide and potassium hydroxide are preferable, and ammonia, sodium hydroxide and potassium hydroxide are more preferable.

The amount of the basic substance used is preferably 0.05 equivalent or more with respect to the carboxyl group, the acid anhydride group or the sulfonic acid group in the polymer block B of the block copolymer. From the viewpoint of fineness, it is more preferably in the range of 0.2 to 5 equivalents, and further preferably in the range of 0.3 to 1.5 equivalents. In addition, 1 equivalent to 1 mol of a carboxyl group is 1 molar equivalent of a basic substance, and 1 equivalent to 1 mol of an acid anhydride group or a sulfonic acid group is 2 molar equivalents of a basic substance.

The dispersion of the block copolymer in the aqueous medium is
It is preferable to carry out at a temperature not lower than the glass transition point of the block copolymer from the viewpoint of obtaining finer and more uniform dispersed particles. In the case of producing an aqueous dispersion containing the above styrene-based polymer, of the block copolymer and the styrene-based polymer, the glass transition temperature is higher than the glass transition temperature of the polymer having a higher glass transition temperature. Dispersing in a medium is preferable because finer and more uniform dispersed particles can be obtained.

The dispersion of the block copolymer in the aqueous medium is
It is carried out by a known method. For example, it can be carried out by using a pressure resistant container equipped with a stirring means, and the stirring means is not particularly limited, but since a large shearing force can be generated, a turbine type stirrer, a colloid mill, a homomixer, a homogenizer is used. preferable. Also,
To disperse the block copolymer in the aqueous medium, use a non-movable line mixer such as a line mixer equipped with a movable stirrer or a "static mixer" (trade name, manufactured by Noritake Co., Ltd.). You may carry out.

In the aqueous dispersion of the present invention, if necessary,
A thickener, a defoaming agent, etc. can be added. Examples of the thickener include carboxymethyl cellulose, methyl cellulose, sodium polyphosphate, polyvinyl alcohol, sodium polyacrylate, casein, vinyl alcohol-methacrylic acid copolymer, starch, and water-soluble polymers such as proteins. it can.

Further, in order to improve the wettability of the material to be coated, a small amount of organic solvent may be added to the aqueous dispersion of the present invention. Further, the aqueous dispersion of the present invention contains, in addition to the above-mentioned compounds, various stabilizers such as antioxidants, weather resistance stabilizers, thermal decomposition inhibitors, and ultraviolet absorbers, if necessary; titanium oxide, organic pigments, etc. A coloring agent; a conductivity-imparting agent such as carbon black or ferrite; an organic or inorganic filler may be contained.

Examples of the antioxidant include 2,6-di-t-butyl-p-cresol and ot-butyl-p-.
Cresol, tetrakis- [methylene-3- (3,5-
Di-t-butyl-4-hydroxyphenyl) propionate] methane, β-naphthylamine, p-phenylenediamine and the like can be mentioned.

Examples of the ultraviolet absorber include 2,4-
Dihydroxybenzophenone, 2- (2'-dihydroxy-3 ', 5'-di-t-butylphenyl) -5-chlorobenzotriazole, 2- (2-hydroxy-3-t
-Butyl-5-methylphenyl) -5-chlorobenzotriazole, bis (2,2 ', 6,6')-tetramethyl-4-piperidine) sebacate and the like can be mentioned.

As the organic filler, for example, wood powder,
Pulp powder; polymer particles such as rayon, vinylon, polyamide, polyamideimide, polyimide, polytetrafluoroethylene, etc. may be mentioned. Examples of the inorganic fillers include silicates such as talc, clay, kaolin and mica; oxides such as silica, titanium oxide, iron oxide and zinc oxide; and hydroxides such as aluminum hydroxide and magnesium hydroxide. Examples thereof include carbonates such as calcium carbonate and magnesium carbonate; sulfates such as barium sulfate and calcium sulfate.

If necessary, a curing agent such as an epoxy compound, an aziridine compound, an oxazoline compound or a carbodiimide compound may be added to the aqueous dispersion of the present invention.

The average particle size of the dispersed substance in the aqueous dispersion of the present invention is storage stability, adhesion to various substrates,
From the viewpoint of adhesiveness, it is preferably in the range of 0.05 to 2 μm, and more preferably in the range of 0.05 to 1 μm.

Since the aqueous dispersion of the present invention has a small particle size of the dispersed substance, phase separation hardly occurs, and the storage stability is good. The aqueous dispersion of the present invention is particularly excellent in adhesiveness and adhesion to nonpolar substrates such as polystyrene, high-impact polystyrene, ABS resin, styrene-conjugated diene block copolymer or its hydrogenated product. In addition, since it has excellent adhesion to polar substrates, coating agents (primers for painting and adhesion,
It is useful as a paint, adhesive, surface modifier, etc.

The shape of the substrate to which the coating agent comprising the aqueous dispersion of the present invention is applied is not particularly limited, and various shaped articles such as films, sheets, fibers and non-woven fabrics can be exemplified. The method for molding the base material is not particularly limited, and any known molding method such as injection molding, compression molding, hollow molding, extrusion molding, rotational molding or the like may be used.

As a method for applying the aqueous dispersion of the present invention to the surface of a substrate, a known method is used, and examples thereof include spray coating and coating with a bar coater or an applicator. The aqueous dispersion can also be applied to the surface of the substrate by immersing the substrate in the aqueous dispersion. After application to the surface of the base material, it can be dried by a method such as natural drying or forced drying by heating to form a coating layer.

The aqueous dispersion of the present invention is a coating agent (waterproofing, releasing, heat-sealing, laminating for articles (molded articles, films, sheets, etc.) of various shapes made of paper, wood, metal, plastic, etc. It is also useful as an adhesive for dissimilar materials in processing, as a primer for inks, paints, etc.);

Further, the aqueous dispersion of the present invention is an aqueous paint,
It is also useful as a binder, pigment dispersant or modifier (gloss imparting, abrasion resistance imparting, water resistance imparting, etc.) in applications such as water-based inks, inkjet inks and copying toners. When the aqueous dispersion of the present invention is used in a paint or an ink, a pigment, a colorant such as a dye, water or a water-soluble solvent, and if necessary, an interface for improving ink fluidity and surface film modification. An activator, a wax, a moisturizer, a viscosity modifier, and other additives are appropriately mixed, and an ink by kneading using a usual ink such as a ball mill, an attritor, a sand mill, and a homogenizer, a paint manufacturing apparatus,
The composition may be suitable for use as a paint.
The composition thus obtained exhibits excellent adhesion to paper, metals, polar resins such as polyester, nylon and polyvinyl chloride, and nonpolar resins such as polystyrene and ABS. Further, this composition may be adjusted with water or the like so that the viscosity of the composition has an appropriate value depending on the purpose of use. In the above, as the coloring agent such as a fee and a dye,
Known ones can be used, for example, azo pigment, azo lake pigment, condensed azo pigment, anthraquinone, thioindigo,
Lakes and toners of oxazine, quinacridone, acid dyes or basic dyes; copper phthalocyanine and its derivatives, condensed polycyclic pigments and mixtures and modifications thereof; talc, clay, titanium oxide, calcium carbonate, carbon black, red iron oxide, antimony red. , Cadmium yellow, cobalt blue, navy blue, ultramarine and the like. The pigment or dye may have a hydrophobic surface, may be surface-treated with rosin or a surfactant, and may have various functional groups such as amino groups and carboxyl groups introduced. Hydrophilicity may be imparted. In addition, with respect to 100 parts by weight of the pigment and the dye, the aqueous dispersion of the present invention is usually 1 to 500 parts by weight in terms of solid content,
It is preferably used in the range of 5 to 200 parts by weight.

Particles to which a block copolymer or a salt thereof is attached by treating the surface of organic or inorganic particles with the aqueous dispersion of the present invention (hereinafter referred to as "composite particles"). Sometimes) is obtained. In the composite particles, the block copolymer or the salt thereof is attached to at least a part of the surface of the core particle. Here, the size of the above-mentioned composite particles and the particles serving as the core thereof can be appropriately selected depending on the application, but the major axis thereof is preferably within a range of 0.01 μm to 50 mm, and 0.05 to 100 μm. It is more preferably within the range. When the aqueous dispersion of the present invention contains a styrene-based polymer, the composite particles are particles in which a block copolymer or a composition thereof and a styrene-based polymer are attached to core particles.

The above treatment is carried out, for example, by adding the aqueous dispersion of the present invention to the core particles and stirring the mixture, or by mixing and stirring the core particles in water to form a suspension state, A method of adding the aqueous dispersion of the present invention with stirring to uniformly disperse it, during the production of core particles (for example, a step of pulverizing a raw material of core particles, and precipitating core particles from an aqueous solution). It can be carried out by a method of adding the aqueous dispersion of the present invention to the step). Further, after the above treatment, the composite particles can be obtained in a dried state by a method of precipitating the composite particles, filtering and drying the composite particles.

The mixing of the aqueous suspension of particles with the aqueous dispersion of the present invention can be carried out by various methods.
It is preferable to use a homomixer, a colloid mill, a ball mill, a sand mill, a homogenizer or the like that generates shearing force.

Examples of the organic particles serving as the core of the above composite particles include wood powder, pulp powder; azo pigment, azo lake pigment, condensed azo pigment, anthraquinone, thioindigo, oxazine, quinacridone, acidic dye or basic dye. Lakes and toners; copper phthalocyanine and its derivatives, condensed polycyclic pigments and mixtures and modifications thereof; polymer particles such as rayon, vinylon, polyamide, polyamide-imide, polyimide, polytetrafluoroethylene, etc. 1 or 2 out of
More than one species can be used. Among these, it is preferable to use organic particles having on their surface at least one functional group selected from a hydroxyl group, an amino group and a carboxyl group. When the composite particles are used as a filler for a polymer such as styrene resin, wood powder, pulp powder, rayon particles, and vinylon particles are more preferable from the viewpoint of the effect of improving mechanical properties.

Examples of the inorganic particles serving as the core of the above composite particles include silicates such as zeolite, talc, clay, kaolin and mica; silica, titanium oxide, iron oxide, zinc oxide, aluminum oxide, and oxides. Oxides such as zirconium; hydroxides such as aluminum hydroxide and magnesium hydroxide; carbonates such as calcium carbonate and magnesium carbonate; sulfates such as barium sulfate and calcium sulfate; carbon black, red iron oxide, antimony red, cadmium yellow, Colored pigments such as cobalt blue, navy blue, and ultramarine; glass powder, glass fiber and the like can be mentioned, and one or more of these can be used. In particular,
It is preferable to use inorganic particles having on the surface at least one functional group selected from a hydroxyl group, an amino group and a carboxyl group.

Examples of the shape of the above-mentioned organic or inorganic particles include needle-like, fibrous and powdery shapes.
When the composite particles are used as a filler for a polymer such as a styrene resin, needle-like or fibrous shapes are preferable from the viewpoint of the effect of improving mechanical properties.

The composite particles to which the block copolymer or its salt is adsorbed are excellent in dispersibility in water and particularly excellent in dispersibility in a styrene-based polymer. By blending the composite particles, various physical properties are excellent. A styrenic polymer composition is obtained.

[0046]

The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. In the following examples, the measurement of the average particle size of dispersed particles, the coatability test, and the carbon black dispersion stability test were conducted as follows.

(Measurement of average particle size) The average particle size was measured by a light scattering method using "ELS800" manufactured by Otsuka Electronics Co., Ltd. (Paintability test) Aqueous dispersion No. Injection molding plate (size: 10 cm × 10 cm × 2 m) of polystyrene [GP666 (trade name, manufactured by Asahi Kasei Corp.)] with a 16 bar coater.
m) or polyester (PET) film [thickness: 1
00 μm, applied to DIAFOIL S (trade name, manufactured by DIAFOIL Co., Ltd.), dried at 50 ° C. for 30 minutes, and then
Heat treatment was performed at 0 ° C. for 30 minutes. The thickness of the obtained coating film was about 8 μm. Then, the following items 1 to 3 were evaluated. 1. Adhesive cellophane tape (trade name, manufactured by Nichiban Co., Ltd.) was applied on the coating film, and then rapidly pulled in a direction of 90 degrees for peeling, and the presence or absence of peeling of the coating film was observed. (Evaluation criteria) ○: No peeling ×: Peeling 2. Transparency PET after applying aqueous dispersion, drying and heat treatment
Regarding the transparency of the film, the total light transmittance was measured using a reflection / transmittance meter [HR-100 (manufactured by Murakami Color Research Laboratory)]. 3. Water resistance One drop of water was dropped on the coating film with a dropper, and after 10 minutes, the water droplets were wiped off, and the appearance of the coating film was visually observed. (Evaluation criteria) ○: No change ×: Change such as cloudiness

(Dispersion stability of carbon black) Carbon black was added to a beaker [manufactured by Mitsubishi Chemical Corporation, "MA-
100 parts (trade name)] and 90 parts by weight of distilled water were added, and the mixture was stirred using a homomixer [manufactured by Tokushu Kika Kogyo Co., Ltd.]. The block copolymer aqueous dispersion was slowly added so that the weight of the solid content in the aqueous dispersion was 10% by weight of the carbon black, and then 3 at 5000 rpm.
Stirring was continued for 0 minutes. The dispersion liquid containing the carbon black obtained above has a carbon black content of 1
After diluting with water so that the weight% becomes 1, the height of the test tube is 1
It was put so as to be 3 cm and left for 1 week. The height of the sedimentation layer formed by sedimentation of carbon black was measured and used as an index of dispersion stability of carbon black in water.

Reference Example 1 [Production of polystyrene block / ethyl acrylate-acrylic acid copolymer block type diblock copolymer] (1) 750 parts by weight of styrene was charged into a reaction vessel, and the temperature was 90 ° C. in a nitrogen atmosphere. The temperature was raised to. Thio-S-acetic acid 0.3
Add 2 parts by weight, and after 30 minutes, radical polymerization initiator [V
-65 (trade name), manufactured by Wako Pure Chemical Industries, Ltd.] in toluene solution (concentration: 5% by weight) at a rate of 6 ml / hr, and further thio-S-acetic acid in toluene solution (concentration: 5% by weight). 9
Polymerization was initiated by continuous addition to the reaction vessel at a rate of ml / hr. The reaction was stopped when the polymerization rate (polymer conversion rate) reached 40%. By pouring the obtained solution into methanol and collecting the resulting precipitate, and drying under reduced pressure,
A polystyrene having a thio-S-acetic acid ester group at the end was obtained. (2) 200 parts by weight of polystyrene having a thio-S-acetic acid ester group at the terminal obtained in (1) above, 200 parts by weight of toluene, and 100 parts by weight of butanol were charged into a reaction vessel, and sodium hydroxide at 70 ° C was added. 1 ml of a methanol solution (concentration: 10% by weight) was added and reacted at the same temperature for 2 hours. The reaction was terminated by adding 0.25 g of acetic acid, the resulting solution was poured into methanol, and the resulting precipitate was collected and dried under reduced pressure to give polystyrene having a mercapto group at its end (hereinafter, abbreviated as polystyrene 1). ) Got. The polystyrene 1 had a number average molecular weight of 11,000 and a mercapto group content of 86 μmol / g.

(3) 100 parts by weight of the polystyrene 1 obtained above, 70 parts by weight of ethyl acrylate, 30 parts by weight of acrylic acid and 200 parts by weight of toluene were charged into a reaction vessel, and at 90 ° C. under a nitrogen atmosphere. A toluene solution (concentration: 0.1% by weight) of a radical polymerization initiator [V-70 (trade name), manufactured by Wako Pure Chemical Industries, Ltd.] is continuously added at a rate of 7 ml / hr to start polymerization. did. When the polymerization rate (polymer conversion rate) reached 95%, the reaction was stopped, and a polystyrene block (polymer block A) and an ethyl acrylate / acrylic acid copolymer block [ethyl acrylate: acrylic acid = 63: 37 (Molar ratio); A diblock copolymer composed of polymer block B] (hereinafter, abbreviated as block copolymer 1) was obtained. In the resulting block copolymer 1, the polymer block A had a number average molecular weight of 11,000 and the polymer block B had a number average molecular weight of 10,000.

Reference Example 2 [Production of polystyrene block / ethyl acrylate-acrylic acid copolymer block-type diblock copolymer] (1) In (1) of Reference Example 1, initial addition of thio-S-acetic acid Except that the amount was changed from 0.32 parts by weight to 0.58 parts by weight and the continuous addition rate of the thio-S-acetic acid in toluene solution (concentration: 5% by weight) was changed from 9 ml / hr to 4 ml / hr. The same operation as in (1) and (2) of Reference Example 1 was performed to obtain polystyrene having a mercapto group at the terminal (hereinafter, abbreviated as polystyrene 2). The polystyrene 2 had a number average molecular weight of 5,100 and a mercapto group content of 185 μmol / g.

(2) A polystyrene block (polymer) was prepared in the same manner as in (3) of Reference Example 1 except that the same weight of polystyrene 2 was used instead of polystyrene 1 in (3) of Reference Example 1. Block A) and a diblock copolymer composed of an ethyl acrylate / acrylic acid copolymer block [ethyl acrylate: acrylic acid = 63: 37 (molar ratio); polymer block B]. Copolymer 2 was obtained). In the resulting block copolymer 2, the polymer block A had a number average molecular weight of 5,100 and the polymer block B had a number average molecular weight of 4,800.

Reference Example 3 [Production of styrene-n-butyl methacrylate block / diethyl acrylate-block copolymer diblock copolymer] (1) 570 parts by weight of styrene, n-methacrylate 180 parts by weight of butyl was charged into a reaction vessel, and the reaction was performed under a nitrogen atmosphere at 90
The temperature was raised to ° C. Thio-S-acetic acid (0.74 parts by weight) was added, and after 30 minutes, a radical polymerization initiator initiator [V-65
(Trade name), manufactured by Wako Pure Chemical Industries, Ltd.] in toluene solution (concentration: 2% by weight) at a rate of 7 ml / hr and further thio-
A toluene solution of S-acetic acid (concentration: 10% by weight) was added to 9.3.
Polymerization was initiated by continuous addition to the reaction vessel at a rate of ml / hr. The reaction was stopped when the polymerization rate (polymer conversion rate) reached 50%. By pouring the obtained solution into methanol and collecting the resulting precipitate, and drying under reduced pressure,
A styrene-n-butyl methacrylate copolymer having a thio-S-acetic acid ester group at the terminal was obtained. Then reference example 1
The same operation as (2) above was performed to obtain a styrene-n-butyl methacrylate copolymer having a mercapto group at the terminal (hereinafter, abbreviated as styrene copolymer 1). The number average molecular weight of the styrene-based copolymer 1 was 4,900, and the content of the mercapto group was 194 μmol / g.

(2) The same operation as in (3) of Reference Example 1 was performed except that the polystyrene 1 was replaced by the same weight of the styrene-based copolymer 1 in (3) of Reference Example 1,
From styrene-n-butyl methacrylate copolymer block (polymer block A) and ethyl acrylate / acrylic acid copolymer block [ethyl acrylate: acrylic acid = 63: 37 (molar ratio); polymer block B] A constituted diblock copolymer (hereinafter, abbreviated as block copolymer 3) was obtained. The number average molecular weight of the polymer block A in the obtained block copolymer 3 was 4,90.
0, the number average molecular weight of the polymer block B was 4,800.

Reference Example 4 [Production of Polystyrene Block / Ethyl Acrylate-Acrylic Acid Copolymer Block Type Diblock Copolymer] 50 parts by weight of polystyrene 1 obtained in (2) of Reference Example 1, acrylic acid 90 parts by weight of ethyl, 10 parts by weight of acrylic acid and 200 parts by weight of toluene were charged into a reaction vessel,
At 0 ° C. under a nitrogen atmosphere, a radical polymerization initiator [V-70
(Trade name) manufactured by Wako Pure Chemical Industries, Ltd.] (concentration: 0.1% by weight) was continuously added at a rate of 7 ml / hr to start polymerization. Polymerization rate (polymer conversion rate) is 9
The reaction was stopped at the time of reaching 5%, and the polystyrene block (polymer block A) and the ethyl acrylate / acrylic acid copolymer block [ethyl acrylate: acrylic acid = 87: 13 (molar ratio); polymer block A diblock copolymer composed of B] (hereinafter, abbreviated as block copolymer 4) was obtained. The number average molecular weight of the polymer block A in the obtained block copolymer 4 was 11,
000, the number average molecular weight of the polymer block B is 20,000
It was 0.

Example 1 20 parts by weight of the block copolymer 1 obtained in Reference Example 1 and 80 parts by weight of xylene were placed in a reaction vessel equipped with a stirrer and dissolved at 100 ° C. Next, 167 parts by weight of an aqueous solution of sodium hydroxide having a concentration of 0.2% was added to the obtained solution.
With stirring, the mixture was continuously added over 1 hour to obtain a suspension.
Xylene was distilled off from the obtained suspension to obtain an aqueous dispersion having a solid content concentration of 20%. 100 parts by weight of this aqueous dispersion and 2 parts by weight of 28% aqueous ammonia were charged into a pressure reaction vessel and stirred at 120 ° C. for 1 hour. After stirring, the mixture was cooled to room temperature to obtain an aqueous dispersion having a solid content concentration of 20% by weight (hereinafter, abbreviated as aqueous dispersion 1). The average dispersed particle diameter in the obtained aqueous dispersion 1 was 340 nm.
Met. Aqueous Dispersion 1 was stable with no change in particle size even when allowed to stand for 1 week.

The aqueous dispersion 1 obtained above was subjected to a coatability test and a carbon black dispersion stability test by the methods described above. The results are shown in Table 1.

Example 2 The same operation as in Example 1 was carried out except that the same weight of the block copolymer 2 was used in place of the block copolymer 1 in Example 1, and the solid content concentration was 20. A wt% aqueous dispersion was obtained (hereinafter, abbreviated as aqueous dispersion 2). The average dispersed particle diameter in the obtained aqueous dispersion 2 is 1
It was 00 nm. Aqueous Dispersion Liquid 2 was stable with no change in particle size even when allowed to stand for 1 week. With respect to the aqueous dispersion liquid 2, a coating property test and a carbon black dispersion stability test were conducted by the methods described above. The results are shown in Table 1.

Example 3 The same operation as in Example 1 was carried out except that the same weight of the block copolymer 3 was used in place of the block copolymer 1 in Example 1, and the solid content concentration was 20. A wt% aqueous dispersion was obtained (hereinafter, abbreviated as aqueous dispersion 3). The average dispersion particle size in the obtained aqueous dispersion 3 was 8
It was 6 nm. Aqueous Dispersion Liquid 3 was stable with no change in particle size even when allowed to stand for 1 week. Regarding Aqueous Dispersion Liquid 3,
A paintability test and a carbon black dispersion stability test were conducted by the above-mentioned methods. The results are shown in Table 1.

Example 4 20 parts by weight of the block copolymer 4 obtained in Reference Example 4 and 80 parts by weight of xylene were placed in a reaction vessel equipped with a stirrer and dissolved at 100 ° C. Next, 150 parts by weight of an aqueous solution of potassium hydroxide having a concentration of 0.1% was continuously added to the obtained solution with stirring for 1 hour to obtain a suspension. Xylene was distilled off from the obtained suspension to obtain an aqueous dispersion having a solid content concentration of 20%. This aqueous dispersion 1
00 parts by weight and 0.9 parts by weight of 28% ammonia water were charged into a pressure reaction vessel and stirred at 120 ° C. for 1 hour. After stirring, the mixture was cooled to room temperature to obtain an aqueous dispersion having a solid content concentration of 20% by weight (hereinafter, abbreviated as aqueous dispersion 4).
The average dispersion particle size in the obtained aqueous dispersion 4 was 620 n.
It was m. Aqueous Dispersion Liquid 4 was stable with no change in particle size even when allowed to stand for 1 week. Aqueous Dispersion Liquid 4 was subjected to a paintability test and a carbon black dispersion stability test by the methods described above. The results are shown in Table 1.

Control Example (Dispersion Stability of Carbon Black) A beaker was charged with 10 parts by weight of carbon black [“MA-100” (trade name) manufactured by Mitsubishi Chemical Corporation) and 90 parts by weight of distilled water, and a homomixer was used. 5,0 using a product manufactured by Tokushu Kika Kogyo Co., Ltd.
The mixture was stirred at 00 rpm for 30 minutes. The obtained dispersion of carbon black was diluted with water so that the concentration of carbon black was 1% by weight, put in a test tube so that the height was 13 cm, and allowed to stand for 1 week. The height of the sedimented layer was measured.

[0062]

[Table 1]

From the results shown in Table 1, the aqueous dispersion of the present invention is
It can be seen that the adhesiveness and water resistance are excellent. Also,
It can be seen that the carbon black to which the salts of the block copolymers 1 to 4 are attached has excellent dispersion stability in water.

Example 5 As a pigment, 10 parts by weight of chromophthal red A2B [trade name, manufactured by Dainippon Ink and Chemicals, Inc.], aqueous dispersion 1
8 parts by weight and 82 parts by weight of water were mixed, put in a small ball mill and kneaded for 1 hour to prepare a red ink. The obtained ink was Normal OA with 16 bar coaters
When applied to paper and polyester (PET) film, no bleeding or repelling was observed.

[0065]

INDUSTRIAL APPLICABILITY According to the present invention, an aqueous dispersion having excellent storage stability and weather resistance, which is excellent in adhesiveness and adhesion to various substrates, as well as in water resistance and weather resistance, is formed. An aqueous dispersion is provided to give.

Front page continuation (51) Int.Cl. ⁷ Identification code FI theme code (reference) C09D 153/00 C09D 153/00 F term (reference) 4J002 BC02X BP03W DE026 GH01 HA06 4J026 HA05 HA06 HA38 HA39 HA48 HB08 HB10 HB11 HB12 HB38 HE01 HE02 4J038 CP061 CQ011 GA03 GA06 GA09 GA10 GA13 JB13 JC06 JC07 JC08 KA03 MA08 MA10 MA14 NA03 NA04 NA10 NA12 NA26 4J039 AD03 AD08 AD09 AD11 AD12 AD17 BC07 BC12 BC16 BC36 BE01 BE02 BE12 BE25 CA06 EA34 EA44 GA38 EA43 EA38 EA38 GA43

Claims (8)

[Claims] 1. A vinyl system having an aromatic vinyl polymer block A and at least one functional group selected from the group consisting of a carboxyl group, an acid anhydride group, a hydroxyl group, a sulfonic acid group, an amino group and an amide group. Monomer unit 2-10
A polymer block B composed of 0 mol% and a unit of 98 to 0 mol% of another vinyl monomer copolymerizable with the vinyl monomer is bonded through a sulfur atom. Aqueous dispersion. 2. The polymer block B is a carboxyl group,
Consists of 2 to 100 mol% of a vinyl monomer unit having an acid anhydride group or a sulfonic acid group and 98 to 0 mol% of another vinyl monomer unit copolymerizable with the vinyl monomer. The aqueous dispersion according to claim 1, which is a polymer block. 3. The block copolymer is dispersed in an aqueous medium containing 0.05 equivalent or more of a basic substance with respect to a carboxyl group, an acid anhydride group or a sulfonic acid group in the block copolymer. The aqueous dispersion according to claim 2. 4. The styrene-based polymer is contained in an amount of 1 to 200 parts by weight based on 100 parts by weight of the block copolymer.
The aqueous dispersion according to any one of 1 to 3. 5. A vinyl group having an aromatic vinyl polymer block A and at least one functional group selected from the group consisting of a carboxyl group, an acid anhydride group, a hydroxyl group, a sulfonic acid group, an amino group and an amide group. Monomer unit 2-10
A block copolymer in which a polymer block B consisting of 0 mol% and a unit of 98 to 0 mol% of another vinyl monomer copolymerizable with the vinyl monomer is bound via a sulfur atom, or Particles with the salt adsorbed. 6. A vinyl group having an aromatic vinyl polymer block A and at least one functional group selected from the group consisting of a carboxyl group, an acid anhydride group, a hydroxyl group, a sulfonic acid group, an amino group and an amide group. Monomer unit 2-10
A block copolymer in which a polymer block B consisting of 0 mol% and a unit of 98 to 0 mol% of another vinyl monomer copolymerizable with the vinyl monomer is bound via a sulfur atom, or Particles adsorbed with a polymer composition comprising 100 parts by weight of the salt and 1 to 200 parts by weight of a styrene polymer. 7. A coating agent comprising the aqueous dispersion according to any one of claims 1 to 4. 8. An ink or paint comprising the aqueous dispersion according to any one of claims 1 to 4.