JPH07116361B2 - Aqueous composition of resin containing polysiloxane - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial Field of the Invention The present invention is capable of crosslinking and curing at low temperature without impairing the characteristics of polysiloxane (for example, low surface tension, excellent water repellency, antifouling property, etc.). , An aqueous composition of a polysiloxane-containing resin having good stability in water.

2. Description of the Related Art There have been many studies on water-solubilization or water-dispersion of polysiloxane-containing resins, but there are various problems in practical use, and improvement thereof is desired. That is, for example, It is not preferable to react polysiloxane having a main chain with a compound having a hydrophilic functional group (hydroxyl group, ether group, etc.) such as ethylene glycol because the surface tension becomes high and the above characteristics of polysiloxane are lost. .

(2) The resin obtained by copolymerizing a polymerizable unsaturated monomer having an acid or a base with a polydialkylsiloxane having a polymerizable unsaturated bond does not have a crosslinkable functional group such as a silanol group, The resin alone cannot crosslink. In addition, if a copolymer of monomers having hydroxyl groups is crosslinked with melamine resin, etc., it is necessary to heat-cure at a high temperature (about 140 ° C or higher), and the glass transition temperature of the cured coating is low. It is not preferable because dust and dirt are likely to adhere to.

(3) A product obtained by copolymerizing γ- (meth) acryloxyalkyltrialkoxysilane or the like with an acid- or base-containing polymerizable unsaturated monomer has a large amount of crosslinkable functional groups per unit weight, so that The stability is not sufficient, gelation may occur, and the film-forming property is poor. If the amount of the above compound is reduced to prevent this, the above characteristics of the polysiloxane will not be exhibited.

Problems to be Solved by the Invention The present invention aims to eliminate all the defects in the above (1) to (3).

Means for Solving the Problems The present inventor has made a polysiloxane macromonomer having two or more hydroxyl groups and / or alkoxyl groups per molecule and a polymerization having or having a hydrophilic functional group. The present inventors have found that a copolymer with a polyunsaturated monomer is stably dissolved or dispersed in water, and has excellent cross-linking curing reactivity, and the present invention has been completed.

That is, the present invention provides (i) the general formula (In the formula, R ₁ represents an aliphatic hydrocarbon group having 1 to 8 carbon atoms or a phenyl group, and R ₂ , R ₃ and R ₄ represent an aliphatic hydrocarbon group having 1 to ₄ carbon atoms or a hydrogen atom.) Compound (A) represented by the formula 70-99.999 mol% and the general formula (In the formula, R ₅ represents a hydrogen atom or a methyl group, and R ₆ , R ₇ and
R ₈ represents a hydroxyl group, an alkoxyl group having 1 to 4 carbon atoms or an aliphatic hydrocarbon group having 1 to 8 carbon atoms. However, the case where all of R ₆ , R ₇ and R ₈ are an aliphatic hydrocarbon group having 1 to 8 carbon atoms is excluded. n shows the integer of 1-6. ) The compound (B) represented by the formula (B) is reacted with 30 to 0.001 mol% and has at least two hydroxyl groups and / or alkoxyl groups per molecule, and the number average molecular weight is about 400 to about 100000. The present invention relates to a polysiloxane-containing resin containing a certain polysiloxane macromonomer and made soluble or dispersible in water, and (iii) an aqueous composition of a polysiloxane-containing resin containing water as a main component.

In the above general formulas (I) and (II), examples of the aliphatic hydrocarbon group having 1 to 4 carbon atoms include a methyl group, an ethyl group,
Examples thereof include straight-chain or branched ones such as propyl group and butyl group, and examples of the aliphatic hydrocarbon group having 1 to 8 carbon atoms include, in addition to the above groups, for example, pentyl group, hexyl group, heptyl group. Examples thereof include linear or branched groups such as groups and octyl groups. Examples of the alkoxyl group having 1 to 4 carbon atoms include methoxy group, ethoxy group,
Examples thereof include linear or branched propoxy groups and butoxy groups.

The polysiloxane macromonomer used in the component (i) of the present invention has a skeleton as a main skeleton, and Si of the main skeleton has an aliphatic hydrocarbon group, a phenyl group, a hydroxyl group, an alkoxyl group, and a polymerizable unsaturated bond. And the like are directly or indirectly bound to each other and can be obtained by reacting the compound (A) with the compound (B).

First, the compound (A) is a compound represented by the general formula (I), and based on the general formula, R ₁ is particularly preferably a methyl group or a phenyl group. R ₂ , R ₃ and R
All ₄ may be the same or partly or completely different. As R ₂ , R ₃ and R ₄ , a methyl group, an ethyl group, a propyl group, a butyl group and a hydroxyl group are particularly preferable. Preferred specific examples of the compound (A) include methyltrimethoxysilane, phenyltrimethoxysilane, butyltrimethoxysilane, methyltriethoxysilane, methyltributoxysilane, phenyltrisilanol and methyltrisilanol. Of these, methyltrimethoxysilane, phenyltrimethoxysilane, phenyltrisilanol and the like are particularly preferably used.

Next, the compound (B) is a compound represented by the general formula (II), and based on the general formula, R ₆ , R ₇ and R ₈
May all be the same or partly or entirely different.
However, all must not be an aliphatic hydrocarbon group having 1 to 8 carbon atoms. As R ₆ , R ₇ and R ₈ , especially a methoxy group,
Ethoxy group and hydroxyl group are preferred, and n is particularly preferably in the range of 2-4. Specific preferred examples of the compound (B) include:
γ-methacryloxypropyltrimethoxysilane, γ-
Methacryloxypropyltriethoxysilane, γ-acryloxypropyltrimethoxysilane, γ-methacryloxybutyltriethoxysilane, γ-acryloxypropyltrisilanol and the like can be mentioned. Of these, γ
-Methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-acryloxypropyltrisilanol and the like are particularly preferable.

The polysiloxane macromonomer is the above compound (A)
And compound (B) are mixed and reacted. The mixing ratio of both compounds is such that the compound (A) is 70 to 99.999 mol%, preferably 90 to 99.9 mol%, more preferably 95 to 99 mol%, based on the total amount of both compounds.
The content of the compound (B) is in the range of 30 to 0.001 mol%, preferably 10 to 0.1 mol%, more preferably 5 to 1 mol%. If the amount of the compound (A) is less than 70 mol%, it tends to be difficult to polymerize linearly and gelation tends to occur, while 99.999
When it is more than mol%, when it is used, it is polymerized mainly by condensation, so that water resistance, chemical resistance, weather resistance and the like are deteriorated, which is not preferable.

The reaction between the compound (A) and the compound (B) is carried out by dehydration condensation of the hydroxyl group of both compounds or the hydroxyl group formed by hydrolysis of the alkoxyl group. On this occasion,
Depending on the reaction conditions, not only dehydration condensation but also partial dealcoholization condensation occurs.

When both the compound (A) and the compound (B) have a hydroxyl group that binds to Si, they can react without being dissolved, but a dehydration condensation reaction is carried out under heating and stirring using an organic solvent capable of dissolving both compounds as a solvent. Is preferred. As the organic solvent, various hydrocarbon-based, ester-based, ketone-based, alcohol-based, and ether-based solvents can be used.

When the compound (A) and / or the compound (B) has an alkoxyl group bonded to Si, it is preferably hydrolyzed prior to the condensation, and usually hydrolyzed by heating and stirring in the presence of water and a catalyst. , Can be condensed. The amount of water used in this case is not particularly limited,
It is preferably 0.1 mol or more per mol of the alkoxyl group. If the amount is less than 0.1 mol, the reaction of both compounds may decrease. The most preferable method is to use water as a solvent in a large excess. Further, as the catalyst in this case, an acid catalyst or an alkali catalyst can be used, and specifically, as the acid catalyst, hydrochloric acid, sulfuric acid, phosphoric acid, formic acid, acetic acid, propionic acid, acrylic acid, methacrylic acid, or the like can be used. Sodium hydroxide, triethylamine, ammonia or the like can be used as an alkali catalyst. The amount of catalyst added is
Based on the total amount of the compound (A) and the compound (B), 0.
A range of about 0001 to 5% by weight, preferably 0.01 to 0.1% by weight is suitable.

A suitable reaction temperature for the above reaction is usually about 20 to 180 ° C, preferably 50 to 120 ° C. Also, the reaction time is
It is usually suitable to set the time to about 1 to 40 hours.

In this reaction system, a water-soluble organic solvent, a polymerization inhibitor, etc. may be added. The water-soluble organic solvent is effective for homogenizing the reaction system when a poorly water-soluble alcohol is produced by hydrolysis and condensation reaction, and for example, alcohol-based, ester-based, ether-based, and ketone-based ones are preferable. Can be used. The polymerization inhibitor is the compound (B)
It is effective for preventing the unsaturated bond contained in the compound from polymerizing during the reaction with the compound (A), and specifically, hydroquinone, hydroquinone monomethyl ether, etc. can be used.

Further, in the production of the polysiloxane macromonomer, in the reaction system of the compound (A) and the compound (B),
Furthermore, even if tetraalkoxysilane or dialkyldialkoxysilane is used in combination, there is no problem, and it is possible to use 20% of both compounds.
It can be used in combination at a mol% or less.

The main skeleton of the polysiloxane macromonomer obtained by the reaction of the compound (A) and the compound (B) is composed of a siloxane bond, and the structure of the main skeleton is mainly long-chain (linear) or ladder (ladder). And mixed systems thereof. These structures can be arbitrarily selected depending on the mixing ratio of the compound (A) and the compound (B), the blending amount of water, an acid catalyst and the like. And
To the Si of the siloxane bond, any one of R ₁ , R _{2 to} R _{4 in} the general formulas (I) and (II), A structure in which any one of R _{6 to} R ₈ is bonded, and a functional group such as a hydroxyl group and / or an alkoxyl group having 1 to 4 carbon atoms (the above R _{2 to} R ₄ and R _{6 to} R ₈ ) 2 or more per 1 molecule of the macromonomer.

The polysiloxane macromonomer preferably has 0.2 to 1.9 polymerizable unsaturated bonds on average per molecule, more preferably 0.6 to 1.4, and more preferably 0.0 to 1.4.
It is most preferable to have 9 to 1.2 pieces. If the amount of polymerizable unsaturated bonds is too small, the copolymerization reaction product of the macromonomer and vinyl monomer tends to become cloudy, while if the amount of polymerizable unsaturated bonds is too large, gelation may occur during the copolymerization reaction. It is not preferable.

Here, the number of unsaturated bonds in the macromonomer can be determined by the following method.

Various polysiloxane-based macromonomers are obtained by appropriately changing the ratios of the compound (A) and the compound (B) and reacting under the same conditions.

With respect to each of the obtained macromonomers, various proportions of the non-functional vinyl monomer are used to synthesize various vinyl copolymers.

The molecular weight distribution of the obtained vinyl copolymer is determined by gel permeation chromatography (GPC).

Even when the use ratio of the macromonomer and the non-functional vinyl monomer is changed, the peak molecular weight of the obtained copolymer (the molecular weight with the highest content rate) is almost the same, and the distribution curve becomes a monopeak, and the low molecular weight component If no distribution of (monomer having no unsaturated bond component) or high molecular weight component (copolymer of macromonomer having two or more unsaturated bonds) is observed, the macromonomer used is 1 It can be said that it has an average of one polymerizable unsaturated bond in the molecule.

For other macromonomers, the compound (A)
The number of moles of the compound (A) used is [A], the number of moles of the compound (B) used is [B], and the number of moles of the compound (A) used to obtain a macromonomer having an average of one polymerizable unsaturated bond is Let [A ₁ ] be the number of moles of compound (B) be [B ₁ ], Can determine the average number of polymerizable unsaturated bonds in the macromonomer.

For example, if a macromonomer having one polymerizable unsaturated bond is obtained in the case of compound (B) / compound (A) = 1/20 (molar ratio), compound (B) / compound (A) = 0.9 In the case of / 20, a macromonomer having an average of 0.9 polymerizable unsaturated bonds is obtained.

The number average molecular weight of the polysiloxane macromonomer is usually about 400 to 100,000, preferably about 1000 to 20,000, and the viscosity of a 50 wt% isobutyl acetate solution at 20 ° C. is usually about 0.5 to 500 centipoise. Is preferred.

The polysiloxane-containing resin that is the component (i) of the present invention is
It is a copolymer containing the above polysiloxane macromonomer and being water-soluble or water-dispersed.

Water-solubilization or water-dispersion is easily carried out by the method exemplified below.

1) The macromonomer is copolymerized with a carboxyl group-containing vinyl monomer, and the carboxyl group is neutralized.

2) The macromonomer is copolymerized with a vinyl monomer containing a base, and the base is neutralized.

3) The macromonomer is copolymerized with a vinyl monomer containing an epoxy group, and then the epoxy group is reacted with an amine and then neutralized.

First, in (1) above, examples of the vinyl monomer containing a carboxyl group include (meth) acrylic acid, crotonic acid, itaconic acid, fumaric acid, maleic acid, and their anhydrides. The carboxyl group-containing vinyl monomer is
It is preferably used in a ratio of 0.1 to 3 mol%, particularly 0.3 to 1.5 mol% based on the total amount of the macromonomer and the carboxyl group-containing vinyl monomer. Further, the number average molecular weight of the copolymer is suitably in the range of about 3000 to 200,000. Examples of the carboxyl group neutralizer include trimethylamine, triethylamine, N, N-dimethylethanolamine, ammonia, pyridine, N, N-diethylethanolamine, N, N-dibutylethanolamine,
Examples thereof include N- (β'-aminoethyl) ethanolamine, N-methylethanolamine, N-methyldiethanolamine, morpholine, N-methylmorpholine, N-ethylmorpholine, cetylmorpholine and piperazine.

In the above 2), as the vinyl monomer containing a base, for example, N-dimethylaminoethyl (meth) acrylamide, N-diethylaminoethyl (meth) acrylamide, N-dimethylaminopropyl (meth) acrylamide, N-dimethylaminoethyl. (Meth) acrylate, Nt-butylaminoethyl (meth) acrylate, acrylamide and the like can be mentioned. These base-containing vinyl monomers are used in an amount of 0.1 to 3 mol%, particularly 0.3 based on the total amount of the macromonomer and the base-containing vinyl monomer.
It is preferably used in a proportion of ˜1.5 mol%.

Further, the number average molecular weight of the copolymer is suitably in the range of about 3000 to 200,000. Examples of the neutralizing agent for the base include formic acid, acetic acid, propionic acid, butyric acid, isobutyric acid and the like.

Examples of the epoxy group-containing vinyl monomer in 3) above include glycidyl acrylate, glycidyl methacrylate, methyl glycidyl acrylate, methyl glycidyl methacrylate, 3,4-epoxycyclohexylmethyl acrylate, and 3,4-epoxycyclohexylmethyl methacrylate. . The epoxy group-containing vinyl monomer is 0.1 to 3 mol%, particularly 0.3 to 3 mol% based on the total amount of the macromonomer and the epoxy group-containing vinyl monomer.
1.5 mol% is preferred.

The number average molecular weight of the copolymer composed of the macromonomer and the epoxy group-containing vinyl monomer is preferably 3000 to 200,000.

The amine that can be reacted with the epoxy group in the copolymer can be the above amine, and the neutralizing agent can be the acid.

In the above 1) to 3), the copolymerization reaction of the siloxane-based macromonomer and various vinyl monomers can be carried out in the same manner as a usual synthetic method of acrylic resin or vinyl resin. Dissolve or disperse in an organic solvent, and in the presence of a radical polymerization initiator, 60 to 18
Copolymerization can be performed by heating at a temperature of about 0 ° C. with stirring. Further, in this copolymerization reaction, vinyl monomers other than those mentioned above may be copolymerized as necessary. Other vinyl monomers include, for example, acrylic acid or methacrylic acid and a monohydric alcohol (having 1 carbon atom).
To 22), hydroxyalkyl (C2-10) acrylates or methacrylates, acrylonitrile, methacrylonitrile, vinyltoluene, styrene and the like.

Further, as the water-soluble organic solvent used in the copolymerization reaction, chlorinated hydrocarbons such as ethylene chlorohydrin, propylene chlorohydrin, valerolactone, ethylene glycol monomethyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate , Ester type such as methoxytriglycol acetate, methyl lactate, ethyl lactate, dioxolane, dioxane, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol diethyl ether, diethylene glycol Monobutyl ether, ethoxytriglycol, etc. Ether, methanol, ethanol, allyl alcohol, n-, an iso-propanol,
alcohol-based compounds such as t-butanol, ethylene glycol, propylene glycol, butylene glycol, hexane diol, heptane diol, dipropylene glycol, triethylene glycol and tripropylene glycol, and ketone-based compounds such as acetone, acetonylacetone and diacetone alcohol. Organic solvents having almost infinite solubility in water are listed. Among them, n-propanol, iso-propanol, diacetone alcohol,
It is particularly preferable to use ethylene glycol monobutyl ether, ethylene glycol monoethyl ether, acetic acid ethylene glycol monoethyl ether, or the like.

Further, a small amount of these water-soluble organic solvents, specifically, 50 parts by weight or less per 100 parts by weight of the water-soluble organic solvent, may be used in combination with other water-insoluble organic solvents.

The aqueous composition of the present invention can be easily obtained by adding water to a solution or dispersion of a polysiloxane-containing resin of component (i) obtained as described above in a water-soluble organic solvent. It is also possible to add water after removing a part or all of the product by vacuum distillation.

It is also possible to remove the organic solvent by distillation under reduced pressure after mixing water.

The aqueous composition of the present invention is useful for paints, surfactants, surface treatment agents and the like. Further, in the polysiloxane-containing resin which is the component (i) of the aqueous composition, since the side chain has the polysiloxane structure portion of the component (I), a functional group (hydroxyl group or alkoxyl group) per unit molecular weight is obtained.
Since the amount is such that storage stability of the aqueous composition is not deteriorated, there is no thickening or gelation, and it has a functional group in an amount necessary for cross-linking and curing, so that it can be dissolved or dispersed in water. The functional group serves as a catalyst and has excellent curability at low temperatures. Furthermore, since the content of the polysiloxane structure portion can be increased, its characteristics such as low surface tension, water repellency, antifouling property, and adhesion to an inorganic material can be exhibited.

Therefore, when the aqueous composition of the present invention is used as a paint, electrodeposition coating (cation, anion), spray coating,
Electrostatic coating and dip coating are possible and have the following effects.

1) It has sufficient crosslinkability even by itself and is excellent in film forming property.

2) It has water repellency and is excellent in water resistance and chemical resistance.

3) The coating film has good weather resistance.

4) Excellent heat resistance.

5) Excellent stain resistance.

Examples Examples of the present invention will be shown below.

Example 1 Methyltrimethoxysilane 2720 g (20 mol) γ-methacryloxypropyl 256 g Trimethoxysilane (1 mol) Deionized water 1134 g 60% hydrochloric acid 2 g Hydroquinone 1 g These mixtures were reacted at 80 ° C. for 5 hours. The number average molecular weight of the obtained polysiloxane macromonomer is 2000,
On average, one molecule had one vinyl group (polymerizable unsaturated bond) and four free hydroxyl groups. A mixture of 300 g of this macromonomer, 100 g of styrene, 100 g of acrylic acid, 500 g of n-butyl acrylate, 20 g of azoisobutyronitrile (polymerization catalyst) was added dropwise to 800 g of cellosolve at 120 ° C. to perform polymerization.
A transparent copolymer was obtained. The number average molecular weight was about 20,000.

To this, 124 g of dimethylaminoethanol was added, and 3000 g of water was added.
It was diluted with to obtain a milky white aqueous dispersion.

This product did not show any change such as gelation and deterioration of film-forming property even after storage at 50 ° C. for 1 month.

The obtained composition was coated on a glass plate so as to have a film thickness of 10 μm based on the dry coating film, and dried at room temperature for 24 hours.
The gel fraction of the coating film was 77%, and the adhesion, water repellency, stain resistance, weather resistance and smoothness were excellent.

Example 2 Phenyltrisilanol 7800 g (50 mol) γ-acryloxypropyl 200 g Trisilanol (1 mol) toluene 4500 g These mixtures were reacted at 117 ° C. for 3 hours to dehydrate.
The number average molecular weight of the obtained polysiloxane-based macromonomer is 7,000, and one vinyl group and 5-10 per molecule on average.
It had individual free hydroxyl groups. 100g of this macromonomer
And N-dimethylaminoethyl acrylamide 100g methyl methacrylate 200g 2-ethylhexyl methacrylate 600g azoisobutyronitrile 10g mixture was added dropwise into butyl cellosolve 800g at 120 ° C.
Polymerization was performed to obtain a copolymer.

The number average molecular weight was about 40,000. After neutralizing with 34 g of formic acid, this was dispersed in 4200 g of water to obtain a milky white aqueous dispersion.

This product did not show any change such as gelation and deterioration of film-forming property even when stored at 50 ° C. for 1 month.

The coating film coated and cured in the same manner as in Example 1 had a gel fraction of 64% and was excellent in adhesion, water repellency, stain resistance, weather resistance, smoothness and the like.

Example 3 48 mol of phenyltrimethoxysilane and 2 mol of γ-methacryloxyethyltriethoxysilane were reacted in the same manner as in Example 1. The number average molecular weight of the obtained polysiloxane macromonomer was about 5,000, and on average, one molecule had one vinyl group and 5 to 10 free methoxy groups. The macromonomer (500 g) was polymerized in the same manner as in Example 1 with 100 g of glycidyl methacrylate, 100 g of styrene, 500 g of n-butyl acrylate and 20 g of azoisobutyronitrile. A copolymer was obtained. The number average molecular weight was about 60,000.

After 80 g of triethylamine was reacted at 80 ° C. for 4 hours, 42 g of acetic acid and 4000 g of water were added and dispersed in water to obtain an aqueous dispersion.

This product showed good stability even after storage at 50 ° C. for 1 month without showing any change such as gelation and deterioration of film-forming property.

The coating film coated and cured in the same manner as in Example 1 had a gel fraction of 66% and was excellent in adhesion, water repellency, stain resistance, weather resistance, smoothness and the like.

Claims (1)

[Claims] 1. (i) General formula (In the formula, R ₁ represents an aliphatic hydrocarbon group having 1 to 8 carbon atoms or a phenyl group, and R ₂ , R ₃ and R ₄ represent an aliphatic hydrocarbon group having 1 to ₄ carbon atoms or a hydrogen atom.) Compound (A) represented by the formula 70-99.999 mol% and the general formula (In the formula, R ₅ represents a hydrogen atom or a methyl group, and R ₆ , R ₇ and
R ₈ represents a hydroxyl group, an alkoxyl group having 1 to 4 carbon atoms or an aliphatic hydrocarbon group having 1 to 8 carbon atoms. However, the case where all of R ₆ , R ₇ and R ₈ are an aliphatic hydrocarbon group having 1 to 8 carbon atoms is excluded. n shows the integer of 1-6. The compound (B) represented by the formula (1) is reacted with 30 to 0.001 mol% of the compound (B), and there are two or more hydroxyl groups and / or alkoxyl groups per molecule, and the number average molecular weight is about 400 to about 100,000. A polysiloxane-containing resin containing a certain polysiloxane macromonomer and made soluble or dispersible in water, and (ii) an aqueous composition of a polysiloxane-containing resin containing water as a main component.