JPH1180491A - Aqueous curable composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a composition excellent in storage stability which gives a coating excellent in hardness, flexibility, water resistance and solvent resistance by dispersing an acrylic copolymer obtained by micro suspension polymerization of a radical-polymerizable monomer having an alkoxysilyl group and a copolymerizable radical-polymerizable monomer and a colloidal metal oxide in an aqueous medium. SOLUTION: An acrylic copolymer obtained by micro suspension polymerization of a radical-polymerizable monomer having an alkoxysilyl group (e.g. γ-methacryloxypropyl triethoxysilane) and a copolymerizable radicalpolymerizable monomer (e.g. n-butyl methacrylate) preferably using a radical-polymerizable surfactant of the formula: Z-(AO)n -Y and a colloidal metal oxide which is preferably colloidal silica are dispersed in an aqueous medium. In the formula, Z is a component unit having a radical-polymerizable double bond; AO is an oxyalkylene; n is 2 or more; and Y is an ion-dissociating group.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an aqueous solution comprising an acrylic copolymer having a crosslinkable alkoxysilyl group and / or silanol group in the molecular chain obtained by microsuspension polymerization and a colloidal metal oxide. Regarding the curable composition,
Since the composition is excellent in storage stability and crosslinkability after water evaporation, it can be used in a wide range of applications such as paints, coating agents, binders for fibers and nonwoven fabrics, pressure-sensitive adhesives, adhesives, and rust preventives. It can be awarded in the field.

[0002]

2. Description of the Related Art Conventionally, curable copolymers having a hydrolyzable silyl group represented by an alkoxysilyl group have been widely used for applications such as adhesives, sealing materials, paints and coating agents. However, in these application fields, in order to avoid harm to the human body and environmental pollution due to volatilization of the organic solvent, an aqueous material that does not use an organic solvent is required, and a curable copolymer having the hydrolyzable silyl group is required. The need for aqueous emulsions is increasing for polymers as well.

[0003]

A curable copolymer having a hydrolyzable silyl group must be obtained in the form of a stable aqueous emulsion because it originally has a property of crosslinking while hydrolyzing. Is not easy. For this reason, various attempts have been made to obtain an aqueous emulsion having excellent storage stability. For example, Japanese Unexamined Patent Publication (Kokai) No. 3-227312 discloses that, when an aqueous emulsion polymerization of a monomer having an alkyl (meth) acrylate and an alkoxysilyl group is carried out, the obtained monomer is intended to be stabilized. In addition, a method has been proposed in which a specific water-soluble monomer such as acrylamide, acrylic acid, or styrenesulfonic acid is used in an amount of about 0.1 to 5% by weight and copolymerized. Also, Japanese Patent Laid-Open No. 5-25
No. 354 proposes a method in which a monomer having a hydrolyzable silyl group is copolymerized with a monomer having an amine imide group in an alcohol solvent, water is added thereto to form an emulsion, and the alcohol is further evaporated. Have been. In addition, JP-A-59-152972 discloses, as a coating composition comprising an emulsion of a silane-based synthetic resin having excellent water resistance, an emulsion polymerization of vinylsilane and an acrylic monomer using a polymerizable emulsifier, There is disclosed a composition in which a specific amount of colloidal silica is blended with the obtained copolymer emulsion having a glass transition point of 70 ° C. or lower. However, the self-curable aqueous emulsion containing the conventional curable copolymer having a hydrolyzable silyl group as described above has insufficient storage stability, and even if it has excellent storage stability. The hardness, flexibility, water resistance and solvent resistance of the resulting coating film were insufficient, and an aqueous curable composition having satisfactory performance was not obtained. The present inventors have conducted intensive studies in order to find an aqueous curable dispersion having excellent storage stability and a resulting coating film having excellent hardness, flexibility, water resistance and solvent resistance.

[0004]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that an aqueous emulsion comprising a silyl group-containing polymer obtained by a specific polymerization method and a colloidal metal oxide is in an aqueous dispersion state. In addition to being stable, it has been found that a cross-linking reaction occurs promptly after film formation, resulting in an inorganic / organic composite having excellent performance, thereby completing the present invention. Hereinafter, the present invention will be described in detail.

Acrylic copolymer The acrylic copolymer used in the present invention is a radical polymerizable monomer having an alkoxysilyl group described in detail below.
It is obtained by micro-suspension polymerization of (a) and a radical polymerizable monomer (b) copolymerizable with the monomer (hereinafter referred to as an acrylic silicon copolymer). As the acrylic silicone copolymer, an acrylic copolymer having an alkoxysilyl group and / or a silanol group can be used. The acrylic silicone copolymer having a silanol group is used when the acrylic silicone copolymer having an alkoxysilyl group is produced or after the production thereof, and the alkoxysilyl group derived from the radically polymerizable monomer (a) having an alkoxysilyl group is used. Can be produced by hydrolysis of

A radical polymerizable monomer having an alkoxysilyl group (a) A radical polymerizable monomer having a hydrolyzable alkoxysilyl group (a) which is an essential constituent monomer of the acrylic silicone copolymer Monomer (a)] is a compound represented by the following formula (1).

[0007]

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Wherein R ¹ is a monovalent hydrocarbon group selected from alkyl, aryl and aralkyl groups having 1 to 10 carbon atoms, R ² is a radical polymerizable group, X is an alkoxy group or a halogen atom, a is an integer from 0 to 2. Si
When each of X and R ¹ bonded to is two or more, they may be the same or different groups. As the radical polymerizable group for R ² , an ethylenically unsaturated group is preferable, and a functional group having high radical polymerizability such as a (meth) acryloyl group, a styryl group, a vinyl ester group, and a vinyl ether group is more preferable. In X, the alkoxy group includes a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentanoxy group and a hexanoxy group, and the halogen atom includes F, Cl, Br and I. From the balance between reactivity and stability, X is preferably an alkoxy group having 4 or less carbon atoms.

Specific examples of the monomer (a) include vinyltrimethoxysilane, vinylmethyldimethoxysilane, γ-
Methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, vinyltriethoxysilane, vinylmethyldiethoxysilane, γ
-Methacryloxypropyltriethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, vinyltripropoxysilane, vinylmethyldipropoxysilane, γ-methacryloxypropyltripropoxysilane and γ-methacryloxypropylmethyldipropoxysilane. Can be The monomers may be used in combination of two or more.

A radical polymerizable monomer (b) copolymerizable with the monomer (a); a radical polymerizable monomer copolymerizable with the monomer (a) [hereinafter referred to as monomer (b) ] Include (meth) acrylates, vinyl acetate, vinyl propionate, styrene, α-methylstyrene and the like. Examples of the (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, and n- (meth) acrylate.
Butyl, cyclohexyl (meth) acrylate, (meth)
(Meth) such as 2-ethylhexyl acrylate, lauryl (meth) acrylate and stearyl (meth) acrylate
Alkyl acrylate, hydroxylalkyl (meth) acrylate such as 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate, perfluoroalkyl (meth) acrylate, glycidyl (meth) acrylate, and ( (Meth) acrylic acid N, N-
Diethylaminoethyl and the like. In the case of producing an acrylic silicon copolymer having a silanol group, other than the above, monomers having a carboxyl group such as (meth) acrylic acid, itaconic acid and maleic acid can also be used. On the other hand, when an acrylic silicone copolymer having an alkoxysilyl group and having almost no silanol group is produced, a monomer having the carboxyl group that promotes hydrolysis of the alkoxyl group is used. Desirably not. These monomers can be used alone, but it is usually preferable to select a plurality of components so as to balance the properties of the coating film.

As the monomer (b), an alkyl (meth) acrylate having an alkyl group having 1 to 8 carbon atoms, Styrene, hydroxyalkyl (meth) acrylate having a hydroxyalkyl group having 2 to 3 carbon atoms, and glycidyl (meth) acrylate are preferred. In the case of producing an acrylic silicone copolymer having a silanol group, (meth) acrylic acid is also preferable. In order to maintain the coating properties such as weather resistance, strength and heat resistance at a high level, (meth)
It is preferred to use at least 50 parts by weight of the acrylate.

Production Method The acrylic copolymer used in the present invention is obtained by subjecting monomer (a) and monomer (b) to microsuspension polymerization. Microsuspension polymerization is a method in which the monomer (a) and the monomer (b) are dispersed in fine particles in an aqueous medium, and the dispersion is heated with stirring to perform radical polymerization. ), Monomer (b), surfactant (c) and oil-soluble radical polymerization initiator
It is preferable to disperse the mixture comprising (d) in water in the form of fine particles, and then heat the dispersion with stirring to perform radical polymerization.

Surfactant (c) As the surfactant (c), various surfactants commonly used in ordinary emulsion polymerization, such as anionic, nonionic and cationic surfactants, can be used. It is preferable to use a surfactant having a radical polymerizable group, since the coating film of the resulting composition is excellent in water resistance and weather resistance. As the radical polymerizable surfactant, those containing a polyoxyalkylene group represented by the following general formula (2) and an ion dissociable group are preferable.

[0014]

Embedded image Z- (AO) n-Y (2)

(Wherein, Z is a structural unit having a radical polymerizable double bond copolymerizable with the above component (a), AO is an oxyalkylene group, n is an integer of 2 or more, and Y is an ion dissociable group. The preferred Z in the general formula (2) is a radical polymerizable double bond with a hydrophobic group such as an aromatic hydrocarbon group, an alkyl-substituted aromatic hydrocarbon group, a higher alkyl group or an alicyclic hydrocarbon group. A structural unit in which a bond is combined. Furthermore, Z
Is preferably a (meth) allyl group, a propenyl group or a butenyl group.

The preferred ionicity of the surfactant (c) is an anion. Therefore, Y can be bonded to the group (AO) n by an anionic group, and a cation is ionically bonded to the anionic group. Salts are preferred. Specific examples of the preferred _{Y, -SO 3 Na, -SO 3} NH 4, -COO
_{Na, -COONH 4, -PO 3 Na} 2 , and -PO
₃ (NH ₄ ) _{2 and the} like, more preferably —SO
₃ Na or -SO ₃ is NH _4. N in the group (AO) n is an integer of 2 or more. When n is 1, a monomer
The alkoxysilyl group in (a) becomes unstable and easily decomposed. Preferred n is 300 or less, more preferably 5 to 50. When n is less than 5, the stability of the alkoxysilyl group in the monomer (a) tends to be insufficient, while when n exceeds 300, a coating film formed from a curable emulsion obtained. May show a tendency for the physical properties to decrease. Also, the group (AO) n
In the above, the unit A, that is, the alkylene group is preferably an ethylene group or a propylene group.

Representative examples of the surfactant (c) include compounds represented by the following chemical formulas (3), (4) and (5). In each formula, Y is an ion-dissociable group, and preferred specific examples are as described above.

[0018]

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R ^{3 in} Chemical Formula ³ is preferably a linear or branched alkyl group having 6 to 18 carbon atoms.

[0020]

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R ^{3 in} Chemical Formula 4 is preferably a linear or branched alkyl group having 6 to 18 carbon atoms.

[0022]

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R ^{4 in} Chemical Formula 5 is a hydrogen atom or a methyl group, and R ⁵ is preferably an alkyl group having 8 to 24 carbon atoms.

Oil-soluble radical polymerization initiator (d) Various oil-soluble radical polymerization initiators (d) can be used as long as they are oil-soluble.
Is preferably 10% by weight or less in water, and preferably soluble in the monomer mixture at the reaction temperature. For example, 2,2'-azobisisobutyronitrile, 2,2'-azobis-2,4 dimethylvaleronitrile, 1-azobis-1-cyclohexanecarbonitrile and dimethyl-2,2'-azobisisobutyrate Organic peroxides such as azo initiators such as lauroyl peroxide, benzoyl peroxide, dicumyl peroxide, cyclohexanone peroxide di-n-propylperoxydicarbonate and t-butylperoxypivalate are preferably used. Can be The amount of these polymerization initiators is preferably from 0.1 to 10% by weight, more preferably from 0.1 to 10% by weight, based on the total amount of the monomers (a), (b) and the surfactant (c). It is set in the range of 2-3% by weight.

Microsuspension polymerization In microsuspension polymerization, a mixture comprising the above-mentioned monomer (a), monomer (b), surfactant (c) and oil-soluble radical polymerization initiator (d) is The dispersion is dispersed in water in the form of fine particles, and the dispersion is heated with stirring to perform radical polymerization.

According to the micro-suspension polymerization, a dispersion having a particle size (submicron level) comparable to that of a normal emulsion polymerization product can be obtained irrespective of the suspension polymerization. Since the polymerization is carried out in a state, the polymerization proceeds by the same mechanism as the suspension polymerization method except that the particle size is small. This polymerization is completely different from general emulsion polymerization in which polymer particles grow from an emulsifier micelle using a water-soluble initiator, and non-uniform composition due to a difference in solubility of each monomer in an aqueous phase. Does not happen. Accordingly, the monomer composition and the reactive group density of each polymer particle obtained are the same, and an aqueous dispersion of the polymer having excellent performance is obtained.

In order to carry out the microsuspension polymerization, first, a mixture comprising the monomer (a), the monomer (b) and the oil-soluble polymerization initiator (d) is mixed with a surfactant (c) using an aqueous medium. Disperse in. In the dispersion operation of this monomer or the like in an aqueous medium,
The surfactant (c) may be dissolved in an aqueous medium in advance. The ratio of the monomer dispersed in the aqueous medium is
The appropriate amount of the aqueous medium is about 20 to 150 parts by weight per 100 parts by weight of the total amount of (a) and the monomer (b).

In this case, when an acrylic silicone copolymer having an alkoxysilyl group is produced, a pH buffering agent may be added to stabilize the alkoxysilyl group in the monomer (a). preferable. The pH buffering agent may be dissolved in the aqueous medium in advance or added to the aqueous medium together with the monomer in the dispersion operation of the monomer or the like in the aqueous medium. As the pH buffering agent, a buffering agent suitable for maintaining the pH of the aqueous medium at 6 to 10 is preferable, and examples thereof include organic acids, inorganic acids, bases and salts thereof. Examples include sodium, sodium carbonate, ammonium carbonate, sodium borate, sodium phosphate, sodium sulfate, sodium acetate, ammonium acetate, mono-, di- or triethanolamine, aniline, sodium silicate and the like. Among them, sodium hydrogencarbonate is most preferable in terms of safety, low cost, and the like. Buffer alone or 2
More than one species can be used in combination. In general, the amount used is preferably from 0.01 to 5% by weight in the aqueous emulsion dispersion.

As a method of emulsifying and dispersing, sufficient emulsifying and dispersing can be carried out using a usual rotary homomixer. The emulsified dispersion composed of the monomer (a), the monomer (b), the surfactant (c) and the oil-soluble radical polymerization initiator (d) needs to be fine particles. The thickness is from 02 to 2 μm, and more preferably from 0.1 to 1.0 μm. By making the emulsion having such a particle size, the particle size of the emulsified dispersion obtained after the polymerization can be reduced, the composition of each of the obtained polymers becomes uniform, and the coating film becomes solvent-resistant and water-resistant. It will be excellent. In order to obtain such a particle size, after the treatment with a rotary homomixer, the particle size is reduced using a high-pressure type emulsifying disperser (homogenizer), a dispersing device having a high shear energy such as a turbine type mixer. Is desirable.

An emulsion comprising the monomer (a) and the monomer (b) obtained by the above operation (hereinafter referred to as "monomer emulsion") is heated with stirring to perform radical polymerization.
The polymerization operation is performed by a method of continuously or intermittently feeding the monomer emulsion into the aqueous medium being heated under stirring. As a method for supplying the monomer emulsion,
It is preferable to employ a means for gradually dropping from a dropping funnel. At this time, a preferable amount of the aqueous medium to be charged into the polymerization vessel is 10 to 10 per 100 parts by weight of the monomer emulsion.
The range is 0 parts by weight. The aqueous medium charged into the polymerization vessel is
It contains at least 80% by weight of water, and may contain water-compatible solvents and additives such as alcohol, if necessary. or,
For the purpose of improving the emulsion stability during the polymerization, the surfactant used for preparing the monomer emulsion may be charged in an aqueous medium. In this case, the amount of the surfactant used is preferably 20 parts by weight or less based on 100 parts by weight of the monomer mixture. If this amount exceeds 20 parts by weight, the water resistance of the coating film may decrease. The polymerization temperature varies depending on the polymerization initiator used, but is usually about 40 to 100 ° C, and preferably 70 to 90 ° C. In the case of producing an acrylic silicon copolymer having an alkoxysilyl group, the above-mentioned pH buffering agent can be further blended for the purpose of preventing hydrolysis of the alkoxysilyl group at the time of polymerization. In this case, the mixing ratio of the buffer is preferably such that the pH of the polymerization system becomes 7 to 10. The particle size of the obtained acrylic silicone copolymer is 0.02 to 2 μm
And more preferably 0.1 to 1.0 μm.

The preferred ratio of each component of the acrylic silicone copolymer used in the present invention is as follows. -Monomer (a) 0.1 to 30% by weight-Monomer (b) 99.9 to 70% by weight-Surfactant (c) 0.2 to 20% by weight-Oil-soluble radical polymerization initiator ( d) 0.05-5% by weight

More preferably, the ratio is as follows. Monomer (a) 1 to 20% by weight Monomer (b) 99 to 80% by weight Surfactant (c) 0.2 to 10% by weight Oil-soluble radical polymerization initiator (d) 1-3% by weight

If the proportion of the monomer (a) is less than 0.1% by weight, the curability of the composition may be reduced, while if it exceeds 30% by weight, the resulting coating film becomes brittle. Or the adhesion may decrease. Also, monomer
If the proportion of (b) is more than 99.9% by weight, the curability of the obtained coating film is reduced, while if it is less than 70% by weight, the coating film properties may be reduced. Further, when the proportion of the surfactant (c) is less than 0.2% by weight, the dispersibility at the time of polymerization is lowered and blocking tends to occur, and when it exceeds 20% by weight, the water resistance of the coating film is lowered. May drop. Further, if the amount of the oil-soluble radical initiator is less than 0.05% by weight, the polymerization reaction does not proceed sufficiently and the residual monomer increases, and the odor may become strong. Properties and weather resistance may be reduced.

◎ Colloidal metal oxide The colloidal metal oxide used in the present invention means a sol in which an oxide of a metal such as silicon, aluminum, titanium and zirconium is finely dispersed in water. Specific examples include sols such as silica, alumina, titania, and zirconia. Among them, silica sol (colloidal silica) is most commonly used, and is also preferably used in the present invention. On the particle surface of the colloidal silica, -SiOH groups and SiOH- ions are present, an electric double layer is formed by alkali ions, and the particles are stabilized in water by repulsion between the particles. The particle diameter of the primary particles is usually 2 to 100 nm.
In particular, those having a thickness of 5 to 50 nm are preferably used. The state of the dispersion may be either the acidic side or the basic side. Colloidal silica is usually commercially available as an aqueous dispersion, and includes, for example, Huderite AT (manufactured by Asahi Denka Kogyo), Snowtex (manufactured by Nissan Chemical), Ludox (manufactured by DuPont), Narcoag (manufactured by National Aluminate) and Cytron (monsanto) Chemical).

Aqueous curable composition The aqueous curable composition of the present invention can be produced by a conventional method such as mixing an acrylic silicon copolymer and a colloidal metal oxide. In this case, the method of mixing the two components is not particularly limited, and may be mixed by a usual method such as stirring or shaking. The mixing time is at the time of production of the acrylic silicone copolymer, preferably at the time of microsuspension polymerization,
The colloidal metal oxide can be added to the pre-emulsion or the aqueous medium, or after the production of the acrylic silicon copolymer, the colloidal metal oxide can be added to the copolymer and mixed. In the aqueous curable composition of the present invention, the ratio of the acrylic silicone copolymer and the colloidal metal oxide is preferably acrylic silicone copolymer / colloidal metal oxide = 20 to 95/80 to 5 (weight ratio). , More preferably 30-85 / 70-15.
If the ratio of the acrylic silicone copolymer is less than 20,
The cured resin may have insufficient impact resistance and adhesion to the substrate, and if it exceeds 95, crosslinkability may be reduced.
Further, in order to enhance the storage stability of the composition, the pH can be adjusted by adding a buffer. When the acrylic silicon copolymer has an alkoxysilyl group, p
It is preferable to adjust to a basic side of H8 to 10, and when the acrylic silicon copolymer has a silanol group, it may be an acidic side of pH 2 to 6 or an acidic side of pH 8 to 10.
It is preferable to adjust to any of the basic sides of the above.

A coating film can be obtained by applying the aqueous curable composition of the present invention and volatilizing water at room temperature or under heating. The coating film is crosslinked and cured by a condensation reaction between an alkoxysilyl group or a silanol group derived from the acrylic silicon copolymer and a silanol group on the surface of the colloidal metal oxide.
The crosslinking reaction proceeds rapidly even at room temperature, but if it is desired to further promote crosslinking, a curing catalyst may be added. As curing catalysts, for example, organic titanate compounds such as isopropyl triisostearoyl titanate and isopropyl tri (dioctyl pyrophosphate) titanate, organic tin compounds such as tin dioctylate, dibutyltin dilaurate and dibutyltin malate, and organic compounds such as paratoluenesulfonic acid Acid catalysts may be mentioned.

◎ Other Components The aqueous curable composition of the present invention may contain various additives commonly used in applications such as paints, coating agents, binders for fibers and nonwoven fabrics, adhesives and rust inhibitors, for example, Fillers such as clay, talc, calcium carbonate and titanium white,
Pigments, dyes, film-forming aids, plasticizers, various surfactants used for wetting, dispersion, defoaming, etc., antistatic agents, thickeners, thixotropy-imparting agents, antifreezing agents, various crosslinking agents, anti-fog Agents, lubricants, metal powders, antioxidants, ultraviolet inhibitors, antibacterial agents, antifungal agents, tackifiers, rust inhibitors, and the like can be added in appropriate amounts as needed. In the present invention, it is preferable to mix a film-forming aid used in a water-based paint. Examples of the film-forming auxiliary include cellosolve such as butyl cellosolve, carbitol, and glycol ether such as tripropylene glycol-n-butyl ether.

Use The composition of the present invention is suitable as a coating agent or a binder, and specifically, for example, a coating material for building materials, such as glass, slate, metal, wood or plastic, a coating for acid rain, It can be used as fouling paint, water repellent for inorganic building materials, moisture-proof coating agent for electrical and electronic parts, back coating agent for magnetic tape, sealing agent, fiber treatment agent, binder for fibers and non-woven fabric, binder for ink and adhesive. it can.

When used as a pressure-sensitive adhesive, it has excellent heat resistance, so that it does not creep or peel even when used at high temperatures, and has a feature of maintaining stable adhesive strength for a long time. Since it has excellent removability at high temperatures, it can be used as a masking tape or surface protection tape.

[0040]

The present invention will now be described more specifically with reference to examples and comparative examples. In addition, "parts" in each example means parts by weight. The surfactant “AQUALON HS10” (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) used in the production examples is a radical polymerizable emulsifier represented by the following chemical formula (6).

[0041]

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Production Example 1 (Production of Acrylic Silicone Copolymer Having Alkoxysilyl Group) (1) Preparation of Preemulsion Monomer (a), monomer (b) and emulsifier (c) shown in Table 1 , An initiator, a pH buffer and water are mixed in the amounts shown in Table 1,
Pre-emulsion (monomer emulsion) was prepared by emulsification and dispersion treatment with a homomixer. The particle size of the monomer mixture was about 0.2 μm.

[0043]

[Table 1]

(2) Polymerization Step A flask equipped with a stirrer, a thermometer, and a cooler was charged with 70 parts of deionized water and 2 parts of Aqualon HS10 as an aqueous medium, and the liquid temperature was raised to 85 ° C., followed by stirring. The above pre-emulsion was added dropwise over 3 hours. After completion of the dropwise addition, the temperature of the internal solution was raised to 90 ° C., and the temperature was further maintained for 1 hour to complete the polymerization. No liquid separation and blocking occurred during the polymerization, and the polymerization was carried out stably. In the emulsion of the obtained acrylic silicon copolymer, the average particle size of the copolymer was 0.2%.
At 2 μm, the pH was 9.1. The ethanol content in the emulsion was 0.04%, and the hydrolysis rate was 2%.
It was below.

Production Example 2 (Production of Acrylic Silicone Copolymer Having Silanol Group) A pre-emulsion was prepared in the same manner as in Production Example 1 except that the components shown in Table 2 were used.

[0046]

[Table 2]

Using the obtained pre-emulsion, an acrylic silicon copolymer was produced in the same manner as in Production Example 1. The particle size of the monomer mixture is approximately 0.2 μm.
m. In the emulsion of the obtained acrylic silicone copolymer, the average particle size of the copolymer particles was 0.1%.
At 7 μm, the pH was 2.5. The hydrolysis rate of the alkoxysilyl group was 99.2%, indicating that almost all of the alkoxysilyl group was converted to a silanol group.

Examples 1 to 4 Dispersions of the acrylic silicone copolymers of Production Examples 1 and 2, commercially available colloidal silica [Snowtex 30, Nissan Chemical Industries, Ltd., particle diameter 10 to 20 nm, pH 9.
5-10.5] and tripropylene glycol-n-butyl ether (hereinafter abbreviated as TPNB) at a mixing ratio (in terms of solid content) shown in Table 3 to produce an aqueous curable composition. Using the obtained composition, a coating film having a thickness of 16 μm was formed on a chromated aluminum plate using a bar coater. After the coated plate was cured at 23 ° C. and 40% RH for 2 weeks, the obtained coating film was evaluated as follows. Table 3 shows the results.

Pencil hardness: JIS K5400
It evaluated according to 4.2. -Flexibility: Evaluated using a mandrel having a diameter of 10 mm according to JIS K5400 8.1. ○, Δ, and × in the table indicate the following meanings. ；: No change, △: slight cracking, ×: whitening or peeling-Adhesion: Evaluated by cellophane tape peeling after cutting with lumps (10 × 10 = 100), Displayed inside. -Water resistance: Evaluated by observing the appearance after immersing the coated plate in boiling water for 1 hour. ○, Δ, and × in the table indicate the following meanings. ；: No change, Δ: slight whitening, ×: marked deterioration ・ Xylene resistance: One drop of xylene was placed on the coating film, and the change in the coating film after drying was evaluated. ○, △, × in the table
Indicates the following meaning. ；: No change, △: slight mark remains, ×: coating swells and peels

[0050]

[Table 3] * The number in the composition means the solid part.

Comparative Examples 1 and 2 An aqueous curable composition was produced in the same manner as in Example except that the components shown in Table 4 were used. The obtained composition was evaluated in the same manner as in the examples. Table 4 shows the results.

[0052]

[Table 4] * The number in the composition means the solid part.

[0053]

The aqueous curable composition of the present invention has excellent storage stability and excellent crosslinkability after water vaporization, so that the resulting coating film has excellent hardness, flexibility, water resistance and solvent resistance. Therefore, the composition of the present invention can be applied to a wide range of uses such as paints, coating agents, binders for fibers and nonwoven fabrics, pressure-sensitive adhesives, adhesives and rust inhibitors, and has great industrial value.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08L 33/04 C08L 33/04

Claims (3)

[Claims] An acrylic copolymer obtained by microsuspension polymerization of a radical polymerizable monomer (a) having an alkoxysilyl group and a radical polymerizable monomer (b) copolymerizable with the monomer. An aqueous curable composition obtained by dispersing a polymer and a colloidal metal oxide in an aqueous medium. 2. An acrylic copolymer represented by the general formula Z- (A
O) radical polymerizable surfactant represented by n-Y (c)
(Wherein, Z is a structural unit having a radical polymerizable double bond, AO is an oxyalkylene group, n is an integer of 2 or more, Y
The aqueous curable composition according to claim 1, wherein the aqueous curable composition is obtained by microsuspension polymerization using an ionic dissociable group. 3. The aqueous curable composition according to claim 1, wherein the colloidal metal oxide is colloidal silica.