JPH11335509A - Water borne composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water borne compsn. with an excellent storing stability and coating hardness, and furnishing the coating further with an excellent water resistance, water repellency, stain resistance, flexibility and adhesion to a substrate. SOLUTION: This compsn. is prepd. by dissolving or dispersing, into an aq. dispersion of a polymer, a silicone copolymer comprising, as monomeric units, an alkoxysilyl group-containing radically polymerizable monomer, a carboxyl group-containing radically polymerizable monomer, a silicone macromonomer having one or two vinyl polymerizable groups at one or both of molecular terminals, and optionally a radically polymerizable monomer copolymerizable with any of the above monomers wherein by a part or the whole of the carboxyl group in the copolymer is neutralized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an aqueous dispersion of a polymer, particularly a crosslinkable alkoxysilyl group and / or
Also, the present invention relates to an aqueous composition capable of improving water resistance, water repellency, drying property, mold release property, stain resistance and the like in an aqueous dispersion of a (meth) acrylic silicone copolymer having a silanol group. Since the coating film formed from the composition of the present invention has a silicone-rich coating film surface, it is excellent in water resistance, water repellency, drying property, stain resistance and the like, and paints, coating agents, binders for fibers and nonwoven fabrics, and the like. It can be used in a wide range of applications such as rust inhibitors and can be awarded in these technical fields.

[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 an alkoxysilyl group is also required. Various studies have been made on aqueous emulsions. However, a curable copolymer having an alkoxysilyl group has a property that the alkoxysilyl group crosslinks while hydrolyzing, and thus it is not easy to obtain a stable aqueous emulsion.

[0003]

The present inventors have solved the above-mentioned problem by providing a monomer containing an oil-soluble initiator as an aqueous emulsion, and supplying the aqueous emulsion to heated water.
It has been found that a curable copolymer obtained by using so-called microsuspension polymerization has excellent stability and crosslinkability (Japanese Patent Laid-Open No. 149840/1995). However, the coating film formed from the curable copolymer has excellent physical properties such as high hardness due to the action of an alkoxysilyl group having room temperature crosslinkability, but the coating film has water resistance, water repellency, and water resistance. In some cases, stainability, flexibility, and adhesion to a substrate were insufficient. The present inventors have been keen to find an aqueous composition which is excellent in storage stability and hardness of a coating film, and in which the coating film has excellent water resistance, water repellency, stain resistance, flexibility and adhesion to a substrate. The study was conducted.

[0004]

Means for Solving the Problems As a result of various studies, the present inventors have found that in order to solve the above-mentioned problems, an aqueous dispersion of a polymer is added to a specific water-soluble polymer prepared from a silicone macromonomer. Alternatively, they have found that a composition containing a water-dispersible copolymer can solve the above-mentioned problems, and have completed the present invention. Hereinafter, the present invention will be described in detail. In the present specification, an acrylic polymer or a methacrylic polymer is referred to as a (meth) acrylic polymer, and an acrylic silicon copolymer or a methacrylic silicon copolymer is referred to as a (meth) acrylic silicon copolymer. , Acrylate or methacrylate is referred to as (meth) acrylate, and acrylic acid or methacrylic acid is referred to as (meth) acrylic acid.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Aqueous Dispersion of Polymer A variety of aqueous dispersions of a polymer which is the component (A) of the present invention can be used. Examples thereof include a polymer, a fluorine-based polymer, a vinyl acetate-based polymer and an epoxy-based polymer, and a (meth) acryl-based polymer which is a polymer of a (meth) acrylate ester is preferable.

As the (meth) acrylic acid ester,
Methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate and (meth) acryl Alkyl (meth) acrylates such as stearyl acrylate, hydroxyalkyl (meth) acrylates such as 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate, perfluoroalkyl (meth) acrylate, glycidyl (Meth) acrylate, polyalkylene glycol mono (meth) acrylate, polycaprolactone mono (meth) acrylate, and (meth)
N, N-diethylaminoethyl acrylate and the like can be mentioned.

Among these (meth) acrylates, the alkyl (meth) acrylate having an alkyl group having 1 to 8 carbon atoms and the alkyl group having 2 to 3 carbon atoms are preferable in that the obtained polymer has excellent coating film properties. Having an alkylene group of (meth)
Hydroxyalkyl acrylate is preferred.

Among the aqueous dispersions of the (meth) acrylic polymer, more preferred are (meth) acrylic acid esters, alkoxysilyl group-containing radical polymerizable monomers and, if necessary, copolymers with these monomers. (Meth) obtained by polymerizing a polymerizable radical polymerizable monomer in an aqueous medium
It is an aqueous dispersion of an acrylic silicone copolymer. According to the (meth) acrylic silicon copolymer, the alkoxysilyl group provides the coating film with crosslinkability and excellent physical properties such as high hardness.

As the alkoxysilyl group-containing radical polymerizable monomer (hereinafter referred to as a silyl monomer) constituting the (meth) acrylic silicon copolymer, a compound represented by the following formula (1) is exemplified.

[0010]

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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. In R ¹ , the aryl group includes a phenyl group, and the aralkyl group includes a benzyl group. R ¹ is preferably an alkyl group having 1 to 10 carbon atoms. 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 is F, Cl, Br or the like.
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 silyl monomer include vinyltrimethoxysilane, vinylmethyldimethoxysilane,
γ-methacryloxypropyltrimethoxysilane, γ-
Methacryloxypropylmethyldimethoxysilane, vinyltriethoxysilane, vinylmethyldiethoxysilane, γ-methacryloxypropyltriethoxysilane,
γ-methacryloxypropylmethyldiethoxysilane,
Vinyl tripropoxy silane, vinyl methyl dipropoxy silane, γ-methacryloxy propyl tripropoxy silane, γ-methacryloxy propyl methyl dipropoxy silane and the like can be mentioned. The monomers may be used in combination of two or more.

The (meth) acrylic silicone copolymer may be obtained by copolymerizing another monomer copolymerizable with the above-mentioned monomer, if necessary. Other monomers include (meth) acrylic acid, itaconic acid, maleic acid, vinyl acetate, vinyl propionate, styrene and α-methylstyrene. These monomers can be used alone, but generally, a plurality of components are selected so as to balance the properties of the coating film. Among them, styrene and (meth) are excellent in copolymerizability and physical properties of the coating film.
Acrylic acid.

In the (meth) acrylic silicone copolymer, the preferred content of the (meth) acrylic acid ester is 50 to 90% by weight based on the total amount of the monomers, and the preferred content of the silyl monomer is Content ratio is 0.1-3
0% by weight, more preferably 2 to 20% by weight, and the preferable content ratio of other monomers is 0 to 30% by weight.
It is. The content ratio of (meth) acrylate is 50
If the content is out of the range of 90 to 90% by weight, the weather resistance, strength, heat resistance and the like of the coating film may be reduced. If the content of the silyl monomer is less than 0.1% by weight, the crosslinkability of the composition may be low, and if it exceeds 30% by weight, the coating film may become brittle and the adhesion may be reduced.

The aqueous dispersion of the (meth) acrylic silicone copolymer may be obtained by radical polymerization of the above-mentioned monomer by various methods such as emulsion polymerization, dispersion polymerization and suspension polymerization. Good. The particle diameter of the aqueous dispersion of the (meth) acrylic silicone copolymer is 0.02 to 1.0 μm.
m is preferred. Among these polymerization methods, those obtained by microsuspension polymerization, which is a kind of suspension polymerization, are preferable in that the obtained copolymer has a uniform monomer composition.

In the microsuspension polymerization, an oil-soluble radical polymerization initiator is dissolved in a monomer mixture, and the mixture is dispersed in an aqueous medium using a dispersing device having high shear energy to produce an aqueous emulsion. Then, the aqueous emulsion is added to a heated aqueous medium to polymerize the monomer. This method is characterized in that a dispersion having a particle size (submicron level) equivalent to that of a normal emulsion polymerization product can be easily obtained irrespective of suspension polymerization. It is called microsuspension polymerization or microsuspension polymerization.

As the oil-soluble radical polymerization initiator, a peroxide or azo initiator used in ordinary radical polymerization may be used. For example, when using a microsuspension polymerization method, which is a preferable polymerization method, an oil-soluble radical initiator having a solubility in water at 20 ° C. of 10% by weight or less and dissolving in a monomer mixture at a reaction temperature is used. . Specifically, 2,2′-azobisisobutyronitrile,
2'-azobis-2,4-dimethylvaleronitrile, 1
Azo-based initiators such as -azobis-1-cyclohexanecarbonitrile and dimethyl-2,2'-azobisisobutyrate, lauroyl peroxide, benzoyl peroxide, dicumyl peroxide, cyclohexanone peroxide di-n-propyl peroxide Organic peroxides such as oxydicarbonate and t-butyl peroxypivalate are preferably used. The preferred amount of the radical initiator is 0.05 to 5% by weight, more preferably 0.1 to 3% by weight.
% By weight. If the amount is less than 0.05% by weight, the odor becomes a problem because the monomer remains, and if it exceeds 5% by weight, the polymerization rate is too high and it is difficult to control heat generation.

In the production of the aqueous dispersion of the (meth) acrylic silicone copolymer, various surfactants such as anionic, nonionic and cationic surfactants commonly used in ordinary emulsion polymerization can be used. It is preferable to use a surfactant having a radical polymerizable group (hereinafter, referred to as a polymerizable surfactant) because a high degree of water resistance and weather resistance can be imparted to a cured coating film of the composition. A typical example of the polymerizable surfactant is a compound having a radical polymerizable unsaturated double bond and a hydrophilic portion in the molecule, and is preferably a polyoxyalkylene group represented by the following general formula (2). Anionic or cationic surfactants containing an ionic dissociating group are included.

[0019]

## STR2 ## Z- (AO) n-Y (2)

(In the formula, Z represents an organic group having a radical polymerizable double bond, AO represents an oxyalkylene group, n represents an integer of 2 or more, and Y represents an ion dissociable group.)

Preferred Z in the general formula (2) is
An organic group in which a hydrophobic group such as an aromatic hydrocarbon group, an alkyl-substituted aromatic hydrocarbon group, a higher alkyl group or an alicyclic hydrocarbon group is combined with a radical polymerizable double bond.
As the radical polymerizable double bond in Z, (meth)
Allyl, propenyl or butenyl are preferred.

The preferred ionicity of the polymerizable surfactant in the present invention is an anion.
A salt which can be bonded to the group (AO) n by an anionic group and in which a cation is ionically bonded to the anionic group is preferred. Specific examples of the preferred _Y, -SO 3 _Na, -S
O ₃ NH ₄ , -COONa, -COONH ₄ , -PO ₃
Na ₂ and —PO ₃ (NH ₄ ) _{2 and the} like, and more preferably —SO ₃ Na or —SO ₃ NH ₄ . N in the group (AO) n is an integer of 2 or more. When n is 1, the alkoxysilyl group in the silyl monomer becomes unstable and easily decomposed. Preferred n is 300 or less, and more preferably 5 to 50. When n is less than 5, the stability of the alkoxysilyl group in the silyl-based monomer may be insufficient, whereas when n exceeds 300, the physical properties of the coating film formed from the curable emulsion obtained. May tend to decrease. The unit A in the group (AO) n, that is, the alkylene group, is preferably an ethylene group or a propylene group.

Specific examples of the polymerizable surfactant represented by the formula (2) include, for example, compounds represented by the following formulas (3) to (5). In equations (3) and (4),
As R ³ and R ⁴ , a linear or branched alkyl group having 6 to 18 carbon atoms is preferable. In the formula (5), R ⁵ is a hydrogen atom or a methyl group, and R ⁶ has 8 carbon atoms.
~ 24 alkyl groups are preferred. Equations (3) to (5)
In the above, A ¹ , A ² and A ^{3 each} represent an alkylene group, and in any of the compounds, n is an integer of 2 or more. In the formulas (3) to (5), Y ¹ , Y ² and Y
Reference numeral ³ denotes an ion dissociable group, and specific examples thereof include the same as those for Y.

[0024]

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[0025]

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[0026]

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Preferred examples of these polymerizable surfactants are commercially available. For example, Aqualon (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) represented by the following formula (6) and Adecaria represented by the formula (7) Leap [made by Asahi Denka Kogyo KK] and the like. Aqualon HS05, HS10 and HS20 have the degree of condensation of polyoxyethylene groups n of 5, 10 and 20 in the formula (6), respectively, and the adecali lip SE-10N has the formula (7) Is a compound wherein n is 10.

[0028]

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The compound of the formula (6) is represented by the formula (3)
R ³ is an example of a nonyl group, A is an ethylene group, and Y is an example of SO ₃ NH ₄ .

[0030]

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The compound of the formula (7) is represented by the formula (4)
R ⁴ is a nonyl group, A is an ethylene group, and Y is an example of SO ₃ NH ₄ .

The preferred amount of the surfactant used is 0.2 to 2
0% by weight, more preferably 0.2 to 10% by weight. If the amount is less than 0.2% by weight, the dispersion stability during polymerization may decrease, and if it exceeds 20% by weight, the water resistance of the cured coating film may decrease.

A typical production process for producing a (meth) acrylic silicon copolymer by microsuspension polymerization will be described below. First, a monomer mixture is emulsified and dispersed in an aqueous medium to prepare a pre-emulsion having an average particle size of 0.02 to 10 μm. Usually, a mixture of a monomer component and an oil-soluble initiator is emulsified and dispersed in water in which a surfactant is dissolved in advance. The method of emulsification and dispersion is not particularly limited, but when a normal rotary homomixer is used, it is desirable to increase the output and apply high shear. If a fine emulsion cannot be obtained with a rotary homomixer alone, the mixture is treated with a rotary homomixer and then granulated using a high-pressure emulsifier / disperser (homogenizer) or a disperser having a high shear energy such as a turbine mixer. A method of reducing the diameter is recommended. The pre-emulsion polymerization operation obtained by this operation is carried out by a method of continuously or intermittently supplying the pre-emulsion into an aqueous medium heated under stirring. For the purpose of improving the emulsion stability during polymerization, the surfactant used for preparing the pre-emulsion may be charged in an aqueous medium.

For the purpose of preventing the hydrolysis of the alkoxysilyl group during the polymerization, a known pH buffer may be added.
When the pH during polymerization is kept at 7 to 10 using a pH buffer such as sodium bicarbonate, the decomposition of alkoxysilyl groups is prevented, and an aqueous dispersion of a (meth) acrylic silicon copolymer containing alkoxysilyl groups is obtained. . On the other hand, when the polymerization is carried out without using a pH buffer, the alkoxysilyl group is hydrolyzed and converted into a silanol group to form an aqueous dispersion of a silanol group-containing (meth) acrylic silicon copolymer.

◎ Silicone Copolymer The water-soluble or water-dispersible silicone copolymer of the component (B) in the present invention comprises an alkoxysilyl group-containing radical polymerizable monomer, a carboxyl group-containing radical polymerizable monomer, A silicone macromonomer having a vinyl polymerizable group at one end or both ends and a copolymer having a radical polymerizable monomer copolymerizable with these monomers as a constituent monomer unit, and a carboxyl group of the It is a copolymer partially or wholly neutralized.

As specific examples of the alkoxysilyl group-containing radical polymerizable monomer, those similar to the silyl monomers already described in the section of the aqueous dispersion of the polymer can be used.

Examples of the carboxyl group-containing radical polymerizable monomer include (meth) acrylic acid, itaconic acid, maleic acid, maleic anhydride and fumaric acid, and (meth) acrylic acid is preferred.

As the silicone macromonomer having a vinyl polymerizable group at one or both terminals, those having a number average molecular weight of 1,000 to 50,000 are preferred. When the number average molecular weight is less than 1,000, properties such as water resistance derived from silicone are hardly exhibited. When the number average molecular weight exceeds 50,000, reactivity decreases, and the resulting water-soluble or water-dispersible polymer solution Unreacted silicone may remain. As the silicone skeleton structure of the silicone macromonomer, polydialkylsiloxane is preferable, and polydimethylsiloxane is particularly preferable. As the terminal vinyl polymerizable group, a (meth) acryloyl group and a styryl group are preferable,
(Meth) acryloyl groups are particularly preferred. The silicone macromonomer is produced by a conventionally known method utilizing anionic polymerization (eg, JP-A-59-78236) or a method utilizing a condensation reaction (eg, JP-A-58-167606). What is necessary is just to be obtained.

Radical polymerizable monomers copolymerizable with these monomers (hereinafter referred to as other monomers) include alkyl (meth) acrylate, 2-hydroxyalkyl (meth) acrylate, and (meth) acrylic acid. (Meth) acrylates such as perfluoroalkyl acid, glycidyl (meth) acrylate, polyalkylene glycol mono (meth) acrylate, polycaprolactone mono (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, and acetic acid Examples thereof include vinyl, vinyl propionate, styrene and α-methylstyrene.
Alkyl (meth) acrylate, 2- (meth) acrylate
Examples of the hydroxyalkyl include the same as those described above in the section of the aqueous dispersion of the polymer. Other monomers can be used alone, but generally, a plurality of components are selected so as to balance the physical properties of the coating film.

Among the other monomers, alkyl (meth) acrylate having an alkyl group having 1 to 8 carbon atoms, styrene, and styrene having 2 to 3 carbon atoms are preferable because of their excellent copolymerizability and physical properties of the coating film. Hydroxyalkyl (meth) acrylates having an alkylene group and polyalkylene glycol mono (meth) acrylate are preferred. It is preferable to use (meth) acrylic acid ester in at least 50 parts based on 100 parts of the total weight of the monomer component, since the coating properties such as weather resistance, strength and heat resistance of the coating film can be maintained at a high level. .

In the silicone copolymer, the content ratio of the alkoxysilyl group-containing radical polymerizable monomer unit is as follows:
The amount is preferably 2 to 40% by weight based on the total amount of the monomers.
If this proportion is less than 2% by weight, the crosslinkability of the composition may decrease, and if it exceeds 40% by weight, the coating may become brittle and the adhesion may decrease. The content ratio of the carboxyl group-containing radical polymerizable monomer unit is preferably 2 to 30% by weight based on the total amount of the monomers. If this proportion is less than 2% by weight, the polymer will have insufficient solubility in water to obtain a uniform dispersion, while if it exceeds 30% by weight, the water resistance of the coating film will be reduced. The content ratio of the silicone macromonomer unit is preferably 2 to 50% by weight based on the total amount of the monomers. If the proportion is less than 2% by weight, characteristics such as water resistance and stain resistance due to silicone cannot be imparted to the coating film. Easier to do. The content ratio of the other monomer units is preferably from 0 to 60% by weight based on the total amount of the monomers.

As a method for producing the silicone copolymer of the present invention, a method in which the above-mentioned monomer is subjected to solution polymerization using an organic solvent and the resulting monomer is neutralized is preferable. Examples of the organic solvent include alcohols such as methanol, ethanol, isopropanol and butanol, ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone, acetates such as ethyl acetate, propyl acetate and butyl acetate, and aromatic carbons such as toluene and xylene. Hydrogen and aliphatic hydrocarbons such as hexane and cyclohexane. Of these, alcohols, ketones and acetates having a boiling point of 100 ° C. or lower are preferred, and specific examples include ethanol, isopropanol, acetone, methyl ethyl ketone and ethyl acetate.

The solution polymerization may be performed according to a known method, and is carried out in the presence of a radical initiator such as an azo compound or an organic peroxide.
A method in which the reaction is performed at a temperature of 40 to 150 ° C. can be employed.
If necessary, an appropriate amount of a chain transfer agent such as n-dodecyl mercaptan, mercaptoacetic acid, mercaptoethanol, thiomalic acid and mercaptopropionic acid may be used.

The number average molecular weight of the copolymer before neutralization is 1,0
00 to 50,000, preferably 2,000 to 30,0
00 is more preferred. If the number average molecular weight of the copolymer before neutralization is less than 1,000, the durability of the coating film is insufficient, while if it exceeds 50,000, the solution viscosity tends to be excessively high. The number average molecular weight in the present invention is a molecular weight in terms of polystyrene determined by gel permeation chromatography.

The basic substance used for neutralization includes ammonia, organic amine compounds such as monomethanolamine, dimethylamine, diethylamine, triethylamine, triethanolamine, diethylethanolamine and dimethylethanolamine, and lithium hydroxide and hydroxide. And alkali metal hydroxides such as sodium and potassium hydroxide. The amount of the basic substance used is 20 to 100 mol% based on the amount of carboxyl groups in the copolymer before neutralization.
Is preferable, and 40 to 80 mol% is more preferable. If it is less than 20 mol%, the solubility in water is insufficient, and it tends to aggregate during neutralization. In order to enhance the storage stability of the copolymer, the pH after neutralization is 6 to 8
It is preferable to set

As a specific neutralization operation, a method of adding an aqueous solution of a basic substance to an organic solvent solution of the copolymer obtained by the above polymerization and neutralizing the solution is simple. The resulting aqueous solution or aqueous dispersion of the carboxylate-containing copolymer has a suitable solid content concentration of 5 to 40% by weight by removing the organic solvent under reduced pressure or adding water as necessary. The water solubility or dispersibility of the polymer is obtained. As an organic solvent,
When a water-soluble organic solvent such as alcohol is used, it is not always necessary to remove the organic solvent. Further, as the silicone copolymer, a water-soluble polymer is preferable.

Aqueous Composition The aqueous composition of the present invention is obtained by dissolving or dispersing a silicone copolymer in an aqueous dispersion of the polymer (A). As the ratio of the polymer and the silicone copolymer, the polymer may be 70 to 99 parts by weight and the silicone copolymer may be 30 to 1 part by weight based on the total amount of the polymer and the silicone copolymer. Preferably, more preferably, the polymer is 80 to 98 parts by weight and the silicone copolymer is 20 to 2 parts by weight. If the proportion of the polymer is less than 70 parts by weight, the coating film hardness and weather resistance may decrease,
On the other hand, if it exceeds 99 parts by weight, it may be difficult to exhibit characteristics such as water resistance due to the silicone copolymer. or,
As the content ratio of the polymer and the silicone copolymer in the composition, as a total amount of the polymer and the silicone copolymer,
It is preferably 20 to 70% by weight in the composition.

The method for producing the composition of the present invention includes:
The polymer of the component (A) and the silicone copolymer may be mixed in the presence of an aqueous medium. The method of mixing the two components is not particularly limited, and may be mixed by a usual method such as stirring or shaking. Among these, it is possible to mix the aqueous dispersion of the polymer and the aqueous solution or the aqueous dispersion of the silicone copolymer,
Simple and preferred. At the time of mixing, an aqueous solution or aqueous dispersion of the silicone copolymer may be added during the production of the aqueous dispersion of the polymer (such as during the preparation of a pre-emulsion),
The aqueous dispersion of the polymer and the aqueous solution or aqueous dispersion of the silicone copolymer may be mixed. In order to enhance the storage stability after mixing, the pH can be adjusted by adding a buffer.

A film is obtained by applying the composition of the present invention to a base material and volatilizing water at room temperature or under heating. With the fusion and continuation of the polymer of the component (A), which is the main component,
When (A) is a (meth) acrylic silicone copolymer, it is further crosslinked and cured by a self-condensation reaction of an alkoxysilyl group or a silanol group in the copolymer. At this time, the silicone copolymer improves the uniformity of the coating by filling gaps incompletely fused, and a silicone component having a low surface energy covers the coating surface and functions due to silicone such as water resistance. Is expressed. or,
When the component (A) is a (meth) acrylic silicone copolymer, its alkoxysilyl group or silanol group undergoes self-crosslinking, or a crosslinking reaction with the silicone copolymer proceeds, resulting in interfacial adhesion and durability. Is imparted.

When the component (A) is a (meth) acrylic silicone copolymer, the crosslinking reaction proceeds rapidly even at room temperature.
In order to further promote crosslinking, as a curing catalyst, for example, an organic titanate compound such as isopropyl triisostearoyl titanate and isopropyl tri (dioctyl pyrophosphate) titanate, an organic tin compound such as tin dioctylate, dibutyl tin dilaurate and dibutyl tin malate, Further, an organic acid catalyst such as paratoluenesulfonic acid may be used.

◎ Other components Various additives commonly used for applications such as paints, coating agents and binders for fibers and non-woven fabrics, such as clay, talc, calcium carbonate, titanium white and colloid, are added to the aqueous composition of the present invention. Fillers such as silica, pigments, dyes, film-forming aids, plasticizers, various surfactants used for wetting, dispersion, defoaming, etc., antistatic agents, thickeners, thixotropic agents, antifreeze agents, Various crosslinking agents, anti-fog agents, lubricants,
Appropriate amounts of metal powder, antioxidants, ultraviolet inhibitors, antibacterial agents, antifungal agents, tackifiers, rust inhibitors and the like can be added as necessary.

Use The composition of the present invention is suitable as a coating material or a binder, and applicable substrates include glass, slate, metal, wood and plastic. More specifically, the uses of coating materials are civil engineering / architectural paints, acid rain paints, antifouling paints, anti-graffiti paints, lubricating coating agents, mold release agents, water repellents for inorganic building materials, electricity Examples include a moisture-proof coating agent for electronic components and a back coating agent for magnetic tape. Other uses include sealing agents,
Examples include fiber treatment agents, binders for fibers and nonwoven fabrics, binders for inks, and adhesives.

[0053]

The present invention will be described more specifically below with reference to examples and comparative examples. In each example, “parts” means parts by weight, and “%” means weight%. The surfactant “AQUALON HS10” (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) used in the examples is a compound represented by the above formula (6) wherein n is 10.

Production Example 1 (Production of Aqueous Dispersion of Acrylic Silicone Copolymer) A monomer, an emulsifier, a polymerization initiator, a pH buffer and water were mixed in the amounts shown in Table 1 and mixed with a homomixer. A pre-emulsion (monomer emulsion) was prepared by emulsification and dispersion treatment. The particle size of the monomer mixture was approximately 0.2 μm.

[0055]

[Table 1]

A flask equipped with a stirrer, a thermometer, and a cooler was charged with 70 parts of deionized water as an aqueous medium, the liquid temperature was raised to 85 ° C., and the above pre-emulsion was stirred for 3 hours. It was dropped. 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. The average particle size of the obtained resin dispersion is 0.18 μm.
The pH was 8.4 and the solids content was 44%. The ethanol content in the emulsion liquid is 0.01%,
The hydrolysis rate was 2% or less.

Production Example 2 (Production of water-soluble silicone copolymer) In a glass flask having a stirrer, a reflux condenser, a temperature system, and a nitrogen blowing tube, 20 parts of γ-methacryloxypropyltriethoxysilane, acrylic acid 10 Part, commercially available silicone macromonomer [AK-32 manufactured by Toagosei Co., Ltd.
A macromonomer having a methacryloyl group as a terminal group and a dimethylsiloxane segment, 20 parts of a number average molecular weight of 20,000], polyethylene glycol monomethacrylate [NK ester M manufactured by Shin-Nakamura Chemical Co., Ltd.]
-90G] 10 parts, cyclohexyl methacrylate 20
, 20 parts of n-butyl acrylate, 1.0 part of mercaptopropionic acid and 130 parts of isopropanol, and the temperature was raised to 75 ° C. A solution prepared by dissolving 1.5 parts of 2,2'-azobis- (2-methylbutyronitrile) [ABN-E manufactured by Nippon Hydrajin Kogyo Co., Ltd.] in 20 parts of isopropanol is supplied to the flask over 3 hours. After completion of the dropwise addition, the temperature was maintained at 75 ° C. for 30 minutes. After that ABN-E
The reaction was maintained at reflux by the addition of 0.5 part. The mixture was refluxed for 4 hours to complete the polymerization. The number average molecular weight of the obtained copolymer before neutralization was 7,200, and the weight average molecular weight was 35,000. A mixture of 7.0 parts of 25% aqueous ammonia and 350 parts of distilled water was added to the above-described copolymer solution before neutralization and mixed, and the pressure in the flask was reduced to remove about 200 parts of a mixture of isopanol and water. Thus, a translucent uniform solution of the silicone copolymer was obtained. The solution had a pH of 6.7 and a solids content of 25%.

Examples 1-2 and Comparative Example An aqueous dispersion of the acrylic silicone copolymer produced in Production Example 1, an aqueous solution of the silicone copolymer produced in Production Example 2, and tripropylene glycol-n-butyl ether TPNB) in the proportions shown in Table 2,
An aqueous composition was prepared. The obtained composition was coated on an aluminum-treated aluminum plate using a bar coater to a film thickness of about 10
A micron coating was made. The coated plate was heated at 130 ° C. for 20 minutes and allowed to cool, and the cured coating film obtained was evaluated as follows. Table 2 shows the results.

Pencil hardness: JIS K5400
It measured according to 4.2.・ Adhesion: The cured coating film was roughened (10 × 10 = 100
Eyes), and peeled off with a cellophane tape for evaluation.
The number of eyes with the remaining coating film is shown in the table. -Flexibility: Evaluated using a mandrel having a diameter of 10 mm according to JIS K5400 8.1. -Boiling resistance: After immersing the coated plate in boiling water for 1 hour, it was judged from the change in gloss of the cured coating film, and evaluated in the following three grades. ：: no change Δ: slight whitening ×: whitening ・ Contact angle with water: The contact angle between the cured coating film and water was measured with a goniometer. -Magic stain resistance: Written on the coated surface with three colors of magic ink, immediately after and 24 hours later, wiped off with a tissue paper, and the remaining color was evaluated according to the following three grades. ：: no trace remains △: slight trace remains ×: almost trace remains

[0060]

[Table 2] * The number of composition means part.

[0061]

According to the aqueous composition of the present invention, the coating film has water resistance,
It is excellent in water repellency, stain resistance, flexibility and adhesion to a substrate, and particularly when the component (A) is an aqueous dispersion of a (meth) acrylic silicone copolymer, the hardness of the coating film is further increased. Also excellent. Therefore, the composition of the present invention can be applied to a wide range of uses such as paints, coating agents, and binders for fibers and nonwoven fabrics, and has great industrial value.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Takehisa Yamamura 1 Toagosei Co., Ltd., Nagoya Research Institute, 1 Minami-ku, Minato-ku, Nagoya City, Aichi Prefecture

Claims (4)

[Claims] 1. An aqueous dispersion of (A) a polymer, (B) an alkoxysilyl group-containing radical polymerizable monomer, a carboxyl group-containing radical polymerizable monomer, and vinyl polymerizable at one or both terminals. A silicone macromonomer having a group and, if necessary, a radical polymerizable monomer copolymerizable with the monomer as a constituent monomer unit, wherein one of the carboxyl groups of the copolymer is An aqueous composition in which a part or all of a neutralized silicone copolymer is dissolved or dispersed. 2. Component (A) is an aqueous dispersion of (meth) acrylic acid ester, an alkoxysilyl group-containing radical polymerizable monomer and, if necessary, a radical polymerizable monomer copolymerizable with these monomers. The aqueous composition according to claim 1, which is an aqueous dispersion of a (meth) acrylic silicone copolymer obtained by microsuspension polymerization in a medium. (3) The component (B) contains 2 to 40% by weight of an alkoxysilyl group-containing radical polymerizable monomer unit.
The content ratio of the carboxyl group-containing radical polymerizable monomer unit is 2 to 30% by weight, the content ratio of the silicone macromonomer unit having a vinyl polymerizable group at one end or both ends is 2 to 50% by weight, and copolymerizable. 3. The aqueous composition according to claim 1, which is a silicone copolymer having a radical polymerizable monomer unit content of 0 to 60% by weight. 4. The polymer of component (A) is 70 to 99 parts by weight, based on the total amount of the polymer of component (A) and the silicone copolymer of component (B), The aqueous composition according to any one of claims 1 to 3, wherein the amount of the silicone copolymer is 30 to 1 part by weight.