JP2705148B2 - Resin composition for paint - Google Patents

Description

The present invention relates to a novel and useful coating resin composition. More specifically, a particular film-forming polymer,
It can be used as a water-based paint or a coating agent in various fields such as for building exterior and the like, for paper and fiber processing, etc., with a particulate polymer having a hollow or porous inside as an essential component. The present invention relates to a resin composition for a paint.

[Conventional technology]

As a paint composition for architectural exterior, with waterproofing,
A high gloss type or matte type resin composition is common, respectively.

However, recently, in these fields, there is a strong demand for a composition having so-called moisture permeability.
That is, the conventional coating composition generally does not have such moisture permeability, and when this type of coating is applied to a building, the water vapor generated in the room is inevitably generated on the wall. If the water condenses inside and forms dew condensation, it will stay in the wall, which may reduce the heat insulation of the structure. However, it causes decay or reduces the strength of the building base material, and further causes various problems such as generation of mold and moss.

In addition, even if the coating composition has excellent waterproofing properties, when dew condensation occurs in the wall, the water tends to escape to the outside, causing blisters and peeling,
This is another big problem. Especially in cold regions, the problem is even more serious as frost damage.

Therefore, there is a strong demand for the development of a coating composition that allows water vapor to permeate but does not allow water droplets to permeate.

Of course, as a resin composition having such characteristics, a type containing a silicone resin has already been introduced, but it is still not perfect, and after all, what can be satisfied after all At present, there is no such thing.

[Problems to be solved by the invention]

Therefore, the present inventors have considered that there are various problems in the prior art as described above, and can transmit water vapor,
As a result of intensive studies in search of a resin composition for paint that does not allow water in the form of water droplets to pass, satisfactory performance can be obtained by the presence of a special particulate polymer as detailed below. The inventors have completed the present invention.

[Means for solving the problem]

That is, the present invention comprises, as an essential component, a film-forming aqueous emulsion (I) and a polymer having an alkoxysilyl group in the polymer, which is combined with water-dispersible colloidal silica via the alkoxysilyl group. Resin composition for coatings, comprising a polymer emulsion (II) and a fine particle polymer (III) having a hollow or porous structure, and if necessary, further containing pigments (IV) It is intended to provide.

Here, the above-mentioned film-forming aqueous emulsion (I) can be used without any particular limitation as long as it is generally used as a so-called aqueous binder in aqueous paints and the like.

Preferably, the coating resin composition of the present invention is often used after being dried at room temperature. Even when the film-forming aqueous binder (I) has a minimum film-forming temperature of 40 ° C. or less, Use is appropriate.

As a specific method for preparing the aqueous binder (I), various types of polymerizable unsaturated bond-containing monomers (hereinafter abbreviated as vinyl monomers) as described below can be obtained. The emulsion polymerization may be appropriately selected in accordance with the use of the resin composition for a coating material of the present invention, and may be carried out by an ordinary method using various emulsifiers and polymerization initiators as described below.

That is, typical vinyl monomers include the following.

(Meth) acrylic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid or citraconic acid or an acid anhydride group-containing vinyl monomer such as maleic anhydride or itaconic anhydride and an addition reaction with glycols. Various carboxyl group-containing vinyl monomers such as unsaturated bond-containing hydroxyalkyl ester monocarboxylic acids, such as the acid anhydride groups listed above, including α, β-ethylenically unsaturated mono- or dicarboxylic acids. Α, β-ethylenically unsaturated carboxylic acids such as vinyl monomers; 2-hydroxyethyl (meth) acrylate;
2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth)
Polycarboxylic acids such as maleic acid and fumaric acid, including hydroxyalkyl esters of (meth) acrylic acid such as acrylate, 3-chloro-2-hydroxypropyl (meth) acrylate or polyethylene glycol mono (meth) acrylate Various hydroxyl-containing vinyl monomers represented by unsaturated group-containing polyhydroxyalkyl esters such as di-hydroxyalkyl esters or hydroxyalkyl vinyl ethers such as hydroxyethyl vinyl ether; (meth) acrylamide, N Carboxylic acid amide group-containing vinyl monomers represented by, for example, N-dimethyl (meth) acrylamide, N-alkoxymethylated (meth) acrylamide, diacetone acrylamide or N-methylol (meth) acrylamide; p-styrenesulfonamide, N-methyl-p-styrenesulfonamide or N,
Sulfonamide group-containing vinyl monomers represented by N-dimethyl-p-styrenesulfonamide and the like; N, N-dimethylaminoethyl (meth) acrylate or N, N-
N, N such as diethylaminoethyl (meth) acrylate
-Dialkylaminoalkyl (meth) acrylates and other polycarboxylic acid anhydride group-containing vinyl monomers as described above, and an active hydrogen atom and a tertiary compound capable of reacting with the acid anhydride group-containing vinyl monomer. Tertiary amino group-containing vinyl monomers represented by adducts with compounds having an amino group; cyano group-containing vinyl monomers represented by (meth) acrylonitrile; So-called α, β such as hydroxyalkyl (meth) acrylates and dihydroxyalkyl esters of polycarboxylic acids.
-Vinyl monomers containing a phosphoric ester bond obtained by a condensation reaction between a hydroxyalkyl ester of an ethylenically unsaturated carboxylic acid and a phosphoric ester; sulfone represented by 2-acrylamido-2-methylpropanesulfonic acid and the like. acid group-containing vinyl monomers; methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) such as acrylate or cyclohexyl (meth) acrylate, C ₁ -C ₁₈ becomes straight (Meth) acrylic acid alkyl esters having a chain, branched or cyclic alkyl group; styrene or various derivatives thereof such as styrene, α-methylstyrene, p-tert-butylstyrene or vinyltoluene; Contains (substituted) aromatic nuclei such as acrylate Aromatic vinyl monomers represented by (meth) acrylates; maleic acid,
With unsaturated dicarboxylic acids such as fumaric acid or itaconic acid
Diesters of C ₁ -C ₄ comprising monohydric alcohol; vinyl acetate, (vinyl esters Netherlands Shell Co. branched fatty acids) benzoic acid vinyl or "VeoVa" various vinyl esters represented by the like; " VISCOAT 8F, 8FM, 3F
Or 3FM "(fluorinated (meth) acrylates manufactured by Osaka Organic Chemical Co., Ltd.), perfluorocyclohexyl (meth) acrylate, di-perfluorocyclohexyl fumarate, or N-isopropyl perfluorooctanesulfonamidoethyl (meth) ) (Per) fluoroalkyl group-containing vinyl esters represented by acrylates; various olefins represented by vinyl chloride, vinylidene chloride, vinylidene fluoride, chlorotrifluoroethylene, ethylene, propylene or butadiene; ethylene glycol Represented by di (meth) acrylate, propylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, divinylbenzene, trivinylbenzene or diallyl phthalate , Monomers containing two or more polymerizable unsaturated bond in the molecule; vinyl triethoxysilane,
γ- (meth) acryloyloxypropyltrimethoxysilane, γ- (meth) acryloyloxypropylmethyldimethoxysilane, γ- (meth) acryloyloxypropyltriethoxysilane or γ- (meth) acryloyloxypropylmethyldiethoxysilane Typical examples thereof include a hydrolyzable silyl group-containing vinyl monomer.

Next, the above-mentioned polymer emulsion (II) refers to a specific functional group (reactive polar group) called an alkoxysilyl group.
And an emulsion of a polymer which is bonded to water-dispersible colloidal silica through such an alkoxysilyl group, and specifically, as described above. 100.0 parts by weight of two or more kinds of various polymerizable unsaturated bond-containing monomers (hereinafter abbreviated as vinyl monomers) was added to 2.0% of colloidal silica.
To 400.0 parts by weight, preferably 5 to 400 parts by weight (in terms of solid content) of water obtained by emulsion polymerization in an aqueous system in the presence of an anionic surfactant and / or a nonionic surfactant. It is a dispersible polymer composition.

The term `` colloidal silica '' as used herein refers to a dispersion in water having SiO ₂ as a basic unit, particularly one having a particle diameter of 10 to 30 nanometers. The acid may be on the acidic side or the basic side, and can be appropriately selected according to various conditions at the time of emulsion polymerization.

Among them, first, as the acidic colloidal silica, “Snowtex O” (manufactured by Nissan Chemical Industry Co., Ltd.) and the like are representative. Next, as the basic colloidal silica, “Snowtex” is used. 20,30,40, C
Or N "(the same product).

In preparing the polymer emulsion (II), the use of an alkoxysilyl group-containing vinyl monomer as described above as one of the vinyl monomers improves the compatibility between the organic polymer and the inorganic polymer. From the viewpoint of obtaining a more stable water-dispersible polymer composition, it is preferable in terms of the durability of the final coating film.

In addition, as other vinyl monomers copolymerizable with the alkoxysilyl group-containing vinyl monomer, various vinyl monomers described above are used.

Using the above various materials, for example, JP-A-59-71316
The polymer emulsion (II) can be obtained by emulsion polymerization according to the method disclosed in Japanese Patent Application Laid-Open Publication No. H11-209,878.

In this case, it is needless to say that emulsifiers and polymerization initiators as described later are used.

Next, the hollow fine particle polymer or the fine particle polymer (III) having a porous structure is obtained by emulsion polymerization of a vinyl monomer having a specific composition. This refers to a particulate polymer in which the inside of the particle is hollow or porous. For example, Japanese Patent Application Laid-Open No. 61-62510 or Japanese Patent Application No. 62-169739 filed by the same applicant.
It may be prepared according to a method as disclosed in the specification.

That is, the method disclosed in JP-A-61-62510 is roughly as follows. Copolymer emulsion (C) obtained by emulsion polymerization of polymerizable vinyl monomer (A) and, if necessary, polyfunctional crosslinkable monomer (B) 0.1
-90 parts by weight (in terms of solid content) as seed particles, and 99.9-10 parts by weight of a polymerizable vinyl monomer (D) having a difference in solubility parameter of 0.1 or more with the polymer (C); By subjecting the polyfunctional crosslinkable monomer (E) to emulsion polymerization by adding 0 to 50 parts by weight, a desired fine particle polymer having a hollow or porous structure can be obtained. Examples of the monomer used here include various vinyl monomers as described above, and a monomer that satisfies the above-described conditions may be used.

Of the monomers used herein, preferably, both (A) and (D) are both α, β-ethylenically unsaturated carboxylic acids or their hydrochloric acid, and the total amount of the respective monomers. Is preferably contained within a range of less than 5% by weight. As a preparation method, an emulsion polymerization method as described below can be applied to a predetermined amount of a monomer selected from each monomer group as described above in the presence of an emulsifier, a polymerization initiator and water.

Examples of the emulsifier used at that time include substances having a so-called surfactant, such as an anionic surfactant, a nonionic surfactant, a cationic surfactant, a reactive emulsifier, and an acrylic oligomer. But
Among these, the use of a nonionic surfactant and an anionic surfactant is desirable because the formation of aggregates during polymerization is small and, in addition, a stable emulsion can be obtained.

Typical examples of such nonionic surfactants include polyoxyethylene alkylphenol ether, polyoxyethylene alkyl ether, polyoxyethylene higher fatty acid ester, and ethylene oxide-propylene oxide block copolymer. Representative examples of the ionic surfactant include alkali metal salts of alkyl benzene sulfonic acid, alkali metal salts of alkyl sulfate and alkali metal salts of polyoxyethylene alkyl phenol sulfate.

Further, it goes without saying that a water-soluble oligomer composed of a polycarboxylic acid or a polysulfonate can be used instead of or in combination with the above-mentioned anionic surfactant.

Furthermore, a water-soluble polymer substance such as polyvinyl alcohol or hydroxyethyl cellulose can be used as a protective colloid.

The amount of the emulsifiers and the like listed above is suitably about 0.1 to 10% by weight based on the total amount of the monomers.

Next, the polymerization initiator is not particularly limited as long as it is generally used for emulsion polymerization, and among them, a particularly typical one is a water-soluble initiator such as hydrogen peroxide. Inorganic peroxides; persulfates such as ammonium persulfate or potassium persulfate; organic peroxides such as cumene hydroperoxide or benzoyl peroxide; or azobisisobutyronitrile, azobisisovaleronitrile or azobiscyano. An azo compound such as folic acid may be used, and these may be used alone or in combination of two or more. An appropriate amount of such a polymerization initiator is about 0.1 to 2% by weight based on the total amount of the monomers. It is needless to say that a method known as a so-called redox polymerization method using a combination of such a polymerization initiator with a metal ion and a reducing agent may be used.

Then, in the presence of water, preferably ion-exchanged water, or, if necessary, in the presence of this and an emulsifier, the vinyl monomers as they are, or in an emulsified state, by batch or divided addition, Alternatively, it is continuously dropped into a reaction vessel, and 0 to 10 in the presence of a polymerization initiator as described above.
The polymerization may be performed at a temperature of 0 ° C, preferably 30 to 90 ° C.

At this time, the ratio of the total monomer amount to water is set so that the final solid content of the fine particle polymer (III) falls within the range of 1 to 60% by weight, preferably 15 to 55% by weight. Should.

In performing emulsion polymerization, a so-called seed polymerization method may be used in which emulsion particles are previously present in an aqueous phase and polymerized in order to grow and control the particle diameter. In other words, the use of the seed particle emulsion in preparing the above-described copolymer emulsion (C) consisting of the “seed particles” does not matter at all.

Subsequently, only the vinyl monomers are additionally polymerized in the presence of the emulsion (C). In other words, vinyl monomers in the post-process (post-process) are so-called deposited and polymerized on the surface of the previously synthesized emulsion particles.

In order to obtain the target fine particle polymer (II) in this step, (C)
(D) in the presence of 0.1 to 50 parts by weight based on the solid content of the components
And 50 to 99.9 parts by weight of the monomer mixture constituting the component (E) may be polymerized.

In the polymerization of the components (D) and (E),
Since it is contrary to the gist of the present invention that so-called single particles composed of only the components (D) and (E) are produced in large amounts on a weight basis, additional use of emulsifiers should be avoided as much as possible. Yes, and if necessary, the amount of emulsifier should be kept below 5% by weight, preferably below 2% by weight of the total amount of components (D) and (E).

When the use amount exceeds 5% by weight, a large amount of emulsion particles containing only the components (D) and (E) are produced as by-products. For example, when the particle size molecule (particle size) is measured,
Since an emulsion having two peaks (a so-called bi-modal emulsion) is formed,
Not preferred.

The composition of the vinyl monomers in the thus obtained non-film-forming emulsion particles in which the inside of the particles is hollow or porous may be set so that the glass transition point is 50 ° C. or higher.

The method disclosed in the above-mentioned Japanese Patent Application No. 62-169739 as another method is as follows.

That is, in preparing the aqueous emulsion,
An emulsion containing at least one vinyl monomer is emulsion-polymerized in the presence of an organic titanate compound to obtain a titanium atom-containing emulsion [hereinafter referred to as emulsion (F)]. , And then only vinyl monomers may be additionally polymerized in the presence of the emulsion (F). [Hereinafter, this is referred to as additional polymerization (G). ]
On the surface of the particles of the emulsion (F) containing the previously synthesized organotitanium compound, vinyl monomers in a later step (later step) are deposited and polymerized. By adopting such a production method, the titanium atom or the titanium atom bonded to the organic compound is securely fixed in the emulsion particles finally obtained, and the polymer in the later step is bonded to the titanium atom or the titanium compound bonded to the organic compound. A fine particle polymer emulsion having a hollow or porous structure is obtained, which is completely bonded to the emulsion containing the previously polymerized titanium atoms through the atoms, so that the post-polymerization is completely covered.

The organic titanate compound which is an essential component generally has a structure as described below.

Tetraisopropyl titanate, tetrabutyl titanate, tetrastearyl titanate, 2-ethylhexyl titanate, isopropyltricumylphenyl titanate or isopropyl tri (N-aminoethyl-aminoethyl) titanate, and tetraisopropyl titanate which is a condensate of such various titanates Organic titanium esters represented by polymers or tetrabutyl titanate polymers; isopropyl tristearoyl titanate, isopropyl trioctanoyl titanate, isopropyl di (meth) acryl isosteroyl titanate, diisostearoyl ethylene titanate or dicumyl phenyloxy acetate titanate Organic titanium acylates such as isopropyl tris (dioctyl pyrophosphate) ) Titanate and organic amine salts, isopropyl tri (dioctyl phosphate)
Titanate and organic amine salts thereof, bis (dioctyl pyrophosphate) oxyacetate titanate and organic amine salts thereof or organic titanium-phosphates represented by bis (dioctyl pyrophosphate) ethylene titanate and organic amine salts thereof; isopropyl tridodecyl Organic titanium-sulfonic acid esters represented by benzenesulfonyl titanate; titanium acetylacetonate, titanium lactate, tetraisopropylbis (dioctylphosphite) titanate, tetraoctylbis (ditridecylphosphite) titanate, tetra (2, Organic titanium chelates such as 2-diallyloxymethyl-1-butyl) bis (ditridecyl) phosphite titanate are exemplified. As used herein, the term "organic amine salt" refers to an active acidic hydroxy group derived from the phosphate present in the above-mentioned organic titanium-phosphates, for example, monoethylamine, diethylamine, triethylamine, butylamine, monoethanolamine, diethanolamine, triethanolamine. A substance neutralized with an organic amine such as an amine or morpholine is referred to. The organic amines are preferably those which are volatile at room temperature. Neutralization is carried out such that the molar ratio of the acidic hydroxy group and the organic amine is equal to or more than an equivalent (the organic amine may be in excess).
What is necessary is just to mix at room temperature or cooling. In carrying out the present invention, among these, preferably, use is made of organic titanium-phosphate esters. The amount of the organic titanate compound used is in the range of 0.01 to 30% by weight, preferably 0.05 to 25% by weight, based on the total weight of the organic titanate compound and the vinyl monomers used. It is.

In order to obtain a hollow fine particle polymer or a fine particle polymer (II) having a porous structure according to the present method, as a first step, first, in the presence of various organic titanate compounds as described above, as described above, At least one of various vinyl monomers may be emulsion-polymerized, or a mixture of an organic titanate compound and a vinyl monomer may be emulsion-polymerized at the same time. is there.

In this case, the amount of the vinyl monomer used is 70 to 9% based on the total weight of the organic titanate and the monomer.
A suitable range is 9.99% by weight, preferably 75 to 99.5% by weight.

As the preparation method, respectively, the required amount of the organic titanate compound and the vinyl monomer as described above, an emulsifier,
It is appropriate to use an emulsion polymerization method as described below, which is carried out in the presence of a polymerization initiator and water.

That is, the amount of emulsifiers used is 0.1 to 10 with respect to the total weight of the organic titanate compound and the vinyl monomers.
% By weight, and the amount of the polymerization initiator to be used is about 0.1 to 2% by weight based on the total weight as described above,
As the water, it is desirable to use ion-exchanged water, but in the presence of such ion-exchanged water, if necessary, in the presence of an emulsifier, an organic titanate compound and a vinyl monomer, separately, as is, or In an emulsified state, collectively, by divided addition, or continuously added dropwise to a reaction vessel, or mixed with an organic titanate compound and a vinyl monomer, as is, or in an emulsified state , All at once, or by divided addition, or continuously added dropwise to the reaction vessel, and then in the presence of various polymerization initiators as described above, 0 to 100 ° C, preferably 30 to 90 ° C. What is necessary is just to polymerize at a certain temperature.

The ratio between the total monomer amount and water is determined by the fine particle polymer (II).
Should be set to fall within the range of 0.1 to 60% by weight, preferably 15 to 55% by weight.

In addition, preferably, in carrying out the emulsion polymerization, in order to grow and control the particles, a “seed polymerization method” of preliminarily polymerizing the emulsion particles in the aqueous phase may be used. In some cases, the emulsion polymerization (F) is completed by the emulsion polymerization.

Then, in the presence of the emulsion (F) thus obtained, only the vinyl monomers are additionally polymerized.
The additional polymerization (G), which is the second step, is followed. In order to obtain the target fine particle polymer (II) in this step, 0.1 to 50 parts by weight of the component (F) based on the solid content, This (G)
What is necessary is just to polymerize 50-99.9 weight part of the monomer mixture which comprises a component.

The amount of the additional emulsifiers used in the polymerization of the component (G) is as described above.

The composition of the vinyl monomers in the emulsion particles constituting the emulsion of the fine particle polymer (III) thus obtained may be set so that the glass transition point is 50 ° C. or higher.

In addition, a hollow fine particle polymer or a fine particle polymer having a porous structure obtained according to each method (III)
Can be powdered by a known and commonly used method.

That is, for example, spray drying at a temperature of 100 to 250 ° C, tray or vat drying at a temperature of 50 to 70 ° C,
Alternatively, it can be carried out by fluidized bed drying or the like.

The non-film-forming microparticle polymer obtained here (II
The particle size of the powder of I), that is, the resin powder, is generally different from the “primary particle”, which is a fine particle having the particle size at the time of preparing the fine particle polymer emulsion, with the “secondary particle”, which is an aggregate of the primary particle. Although it is the particle diameter of the resin powder itself, this resin powder can be redispersed in water using a dispersant such as an emulsifier or a protective colloid, if necessary.

Therefore, in preparing the coating resin composition of the present invention, the particulate polymer (III) may be used not only in the form of an emulsion but also in the form of a dry powder.

The ratio of the film-forming aqueous emulsion (I) to the polymer emulsion (II) is 5 to 95 parts by weight of the component (I), based on the solid content.
A suitable range is 95 to 5 parts by weight, preferably 5 to 70 parts by weight of component (I) and 95 to 30 parts by weight of component (II).

The amount of the fine particle polymer (III) is as follows:
An appropriate amount is 0.1 to 30 parts by weight based on 100 parts by weight of the total solid content of these components (I) and (II).

Furthermore, if only typical pigments (IV) described above are mentioned, heavy calcium carbonate, light calcium carbonate, magnesium carbonate, precipitated barium sulfate,
Including mica or titanium oxide, cold water powder, rice powder, kaolin, clay, calcined clay, talc, silica sand, silica coal,
Inorganic pigments or fillers such as ultrafine silica, white carbon, asbestos, pulp powder, dolomite powder, zinc white or carbon black; or organic pigments such as phthalocyanine, azo or quinacridone, or dispersed pigments thereof. .

The amount of the pigments (IV) to be blended is in the range of 0 to 60%, preferably 5 to 30%, and more preferably 7 to 20% in PVC (pigment volume concentration).

Film-forming aqueous emulsions (I) listed above
And the polymer emulsion (II) as an essential component of the film-forming component (film-forming component), while the fine-particle polymer (III) is an essential component of the non-film-forming component, and if necessary, a pigment. The resin composition for a coating material of the present invention can be obtained by blending each of the compounds (IV).
The composition of the present invention comprising the above components may further contain various additive components as described below.

That is, "Chisso Sizer CS-12" (product of Chisso Corporation), butyl carbitol acetate, butyl cellosolve, carbitol, hexylene glycol, cellosolve, dibutyl glycol phthalate, dibutyl phthalate, benzyl alcohol, diisopropyl succinate, "pical (Pycal) 94 ”(product of Astras Chemical Company, USA) or“ Dariad (Daly
ad) A film-forming aid such as "A" (a product of Dow Chemical Company, USA); methanol, ethanol, propanol, ethyl acetate, butyl acetate, acetone, methyl ethyl ketone, methyl isobutyl ketone, toluene, xylene, hexane, heptane or cellosolve. Solvents such as acetate; phthalates such as dioctyl phthalate;
Aliphatic dibasic acid esters such as isodecyl succinate or dioctyl adipate, phosphoric acid esters such as tricresyl phosphate, glycol esters such as diethylene glycol benzoate, epoxy plasticizers such as epoxidized soybean oil, or chlorinated paraffin Plasticizers, such as phenols; emulsifiers, such as anionic or nonionic surfactants as described above; salts of phosphoric acid derivatives such as pyrophosphoric acid, tripolyphosphoric acid or hexametaphosphoric acid, and polycarboxylic acids Various dispersants such as salts of naphthalenesulfonic acid; various drying regulators such as mineral spirit or terpen oil;
Freezing or melting stability imparting agents such as ethylene glycol, propylene glycol or glycerin; various defoaming agents such as silicone or acrylic oligomers or various preservatives; Is appropriately determined according to the conditions.

The resin composition for a paint of the present invention thus obtained can be used as a general or industrial water-based paint such as for architectural exterior or woodwork, or as a coating agent for paper or textile processing, but is not limited thereto. Not something.

〔The invention's effect〕

The coating resin composition of the present invention has a special polymer emulsion (II) that is bonded to water-dispersible colloidal silica via an alkoxysilyl group in the polymer, and has a hollow or porous structure. Special fine particle polymer (II
Through synergistic action with I) and with the film-forming aqueous emulsion (I), it has an unprecedented excellent moisture permeability and also excellent durability and weather resistance. Have

〔Example〕

Next, the present invention will be described more specifically with reference examples, examples and comparative examples.
Unless otherwise noted, all are on a weight basis.

Reference Example 1 [Preparation Example of Polymer Emulsion (II)] Vinyl monomers 2-ethylhexyl acrylate 43 parts Methyl methacrylate 53〃 Acrylic acid 2〃 γ-methacryloyloxypropyltrimethoxysilane 2〃 Surfactants Laurylsulfonic acid Sodium 3 parts Colloidal silicas "Snowtex 30" (solid content = 30%) 150 parts Ion exchange water 160 parts Polymerization initiators Ammonium persulfate 0.5 parts Sodium bisulfite 0.2〃 Interface as shown above in a four-necked flask The activators, colloidal silicas, and ion-exchanged water were charged, the temperature was raised to 60 ° C. with a nitrogen stream, and then the polymerization initiators as described above were added. A mixture of such vinyl monomers was added dropwise over 3 hours. The temperature during the dropping reaction was controlled at 60 to 70 ° C.

After completion of the dropwise addition, the temperature was maintained within the same temperature range for 2 hours, the reaction was continued under stirring, and then cooled. Thereafter, the pH was adjusted to 8 to 9 with 14% aqueous ammonia, and the solid content was reduced to 35%. Thus, a stable, colloidal silica-containing emulsion was obtained. Hereinafter, this is abbreviated as emulsion (II-1).

Reference Example 2 [Preparation Example of Fine Particle Polymer (III)] This example was prepared according to the method disclosed in JP-A-61-62510.

In a reaction vessel equipped with a stirrer, a reflux condenser, a dropping funnel, a thermometer, and a nitrogen inlet tube, 100 parts of ion-exchanged water and "Emulgen 120" (a nonionic surfactant manufactured by Kao Corporation) were added. And 2 parts of “HITENOL N-08” (an anionic surfactant manufactured by the same company) and charged at an internal temperature of 80 parts.
The temperature was raised to 0 ° C to dissolve.

Next, 0.2 part of potassium persulfate, 10 parts of tert-butyl acrylate, 20 parts of styrene, 20 parts of methyl methacrylate and 3 parts of ethylene glycol dimethacrylate were added dropwise over 2 hours and reacted at the same temperature. Let
The reaction was continued at the same temperature for 1 hour to obtain an emulsion intermediate.

Thereafter, in the presence of the whole amount of this emulsion intermediate, at the same temperature, a mixture of 35 parts of styrene, 10 parts of n-butyl acrylate and 2 parts of ethylene glycol dimethacrylate and 0.2 part of potassium persulfate was added. The reaction was carried out by dropping over 2 hours, and the temperature was further maintained at the same temperature for 1 hour, followed by cooling.

Next, the pH was adjusted to 8.4 with 25% aqueous ammonia to obtain a fine particle polymer emulsion. It has a solids content of 51.0% and a "Coulter counter (Coulte
r Counter) N-4 ”, the average particle size (hereinafter the same) was 0.4 μm. Hereinafter, this is abbreviated as emulsion (III-1).

Reference Example 3 (same as above) This example was prepared according to the method disclosed in Japanese Patent Application No. 62-169739.

580 parts of ion-exchanged water was charged into the same reaction vessel as in Reference Example 2, and the temperature was raised to 85 ° C.

Separately, 2 parts of bis (dioctylpyrophosphate) oxyacetate titanate, 186 parts of methyl methacrylate, 10 parts of methacrylic acid and 5 parts of sodium dodecylbenzenesulfonate dissolved in 100 parts of ion-exchanged water A monomer mixture consisting of two parts of ethylene glycol dimethacrylate (the glass transition point of the copolymer obtained from the monomer mixture was 110 ° C.) was added to emulsify.

A mixture of the emulsified product, 2 parts of ammonium persulfate and 120 parts of ion-exchanged water was dropped into the same reaction vessel over 2 hours to cause a polymerization reaction, and after completion of the dropping, the mixture was kept at the same temperature for 1 hour. To complete the reaction. Here, cooling was performed to obtain an emulsion intermediate, which had a solid content of 2
The emulsion was 0.5%, had a pH of 1.5, and had an average particle size of 0.30 microns.

Next, 274.9 parts of ion-exchanged water and 195.1 parts of an emulsion intermediate were charged into the same reaction vessel and heated to 85 ° C.

Separately, a solution obtained by dissolving 7 parts of dodecylbenzenesulfonic acid in 90 parts of ion-exchanged water is added to a monomer mixture composed of 385 parts of styrene and 2 parts of divinylbenzene (a copolymer obtained from the monomer mixture). The glass transition point of the coalescence is 11
5 ° C. ) Was added to emulsify.

A mixture of the emulsion, 3.6 parts of ammonium persulfate and 80 parts of ion-exchanged water was dropped into the same vessel over 2 hours to carry out a polymerization reaction, and after completion of the dropping, the mixture was kept at the same temperature for 1 hour. Upon cooling, an emulsion was obtained which was deposited and polymerized on emulsion particles containing organic titanium. This was an emulsion having a solids content of 40.3%, a pH of 2.5 and an average particle size of 0.62 microns. Hereinafter, this is abbreviated as emulsion (III-2).

Examples 1 to 3 and Comparative Examples 1 to 3 As a film-forming aqueous emulsion (I), “Boncoat EC-818” (a product of Dainippon Ink and Chemicals, Ltd .; nonvolatile content = 50%) was used. The various emulsions obtained in Examples 1 to 3 were also used and mixed at the compounding ratios shown in Table 1, and further, as a thickener,
VL "(product of Badische Japan K.K.)," QR-
708 "(a product of Rohm and Haas Company, USA) and methylcellulose in an amount of 3% based on the above mixture, and stirred and mixed until the viscosity becomes uniform. Each was made into a paint.

Next, each of the paints was separately separated into JIS Z-0
While preparing a test piece for measuring moisture permeability according to the method of 208, apply it to a slate plate with a thickness of 3 mm, leave it at room temperature for one week and let it dry to test for water resistance and weather resistance. Pieces were made.

When the performance of the coating film was compared and examined for each test piece, the results as shown in the table were obtained.However, the coating resin composition of the present invention did not impair moisture permeability and water resistance at all, and showed weather resistance. It is known to provide a cured coating having improved properties.

Notes on Table 1 1) 70% aqueous titanium oxide dispersion 2) Pigment concentration is calculated according to the following formula for calculating PVC (pigment volume concentration), and the density of the solid content of each emulsion Are all "1" and the density of titanium oxide is "4.2".

3) Conforms to the method of JIS Z-0208 4) The test piece is immersed in ion-exchanged water at room temperature for one week, and the state of the coating film surface is visually determined and indicated according to the following criteria.

…: No abnormality at all △: Slight blisters, blisters, etc. are generated ×: Swelling, blisters, etc. are generated over the entire surface 5) Test specimen is placed on "Sunshine Weatherometer"
The state of the surface of the coating film after 250 hours was visually judged and displayed according to the following criteria.

…: There is no abnormality at all. ×: Peeling or gloss occurs.

Claims (4)

(57) [Claims] 1. A film-forming aqueous emulsion (I) and a polymer emulsion having an alkoxysilyl group in the polymer and bonded to water-dispersible colloidal silica via the alkoxysilyl group. A coating resin comprising, as essential components, (II) and a hollow particulate polymer or a particulate polymer having a porous structure (III), and, if necessary, a pigment (IV). Composition. 2. An emulsion (II) of a polymer having an alkoxysilyl group in the polymer and bonded to the water-dispersible colloidal silica via the alkoxysilyl group, contains an alkoxysilyl group-containing emulsion. 100.0 of polymerizable unsaturated bond-containing monomers containing vinyl monomer as an essential component
The resin composition for a paint according to claim 1, which is obtained by emulsion polymerization of parts by weight and 2.0 to 400.0 parts by weight of colloidal silica in terms of solid content. 3. The method according to claim 1, wherein the hollow fine particle polymer or the fine particle polymer having a porous structure (III) comprises a vinyl monomer (A) and, if necessary, a polyfunctional crosslinkable monomer (B). Of a copolymer emulsion (C) obtained by emulsion polymerization of
0.1 to 90 parts by weight (in terms of solid content) are used as seed particles, and 99.9 to 1 of vinyl monomers (D) having a solubility parameter difference of 0.1 or more from the copolymer emulsion (C).
The coating resin composition according to claim 1, which is obtained by adding 0 parts by weight and 0 to 50 parts by weight of the polyfunctional crosslinkable monomer (E) and subjecting to emulsion polymerization. 4. The above-mentioned hollow fine particle polymer or fine particle polymer having a porous structure (III) is obtained by emulsion-polymerizing at least one vinyl monomer in the presence of an organic titanate compound. The resin composition for a paint according to claim 1, which is obtained by performing additional polymerization (G) of only vinyl monomers in the presence of the obtained emulsion (F) containing a titanium atom.