JPS63251463A - Aqueous composition of resin containing polysiloxane - Google Patents

Abstract

PURPOSE:To obtain the title compsn. which can be crosslinked and cured at low temp. is excellent in film forming properties, water repellency, chemical resistance, etc. and gives a coating film having excellent weatherability, by blending a specific resin contg. polysiloxane with water. CONSTITUTION:70-99.999mol.% of a compd. (a) of formula I (wherein R1 is a 1-8C aliph. hydrocarbon group or phenyl; C2, C3 and C4 are each a 1-4C aliph. hydrocarbon group or H) (e.g., methyltrimethoxysilane) and 30-0.001mol.% of a compd. (b) of formula II (wherein R5 is H or CH3; R6, R7 and R8 are each OH, a 1-4C alkoxyl or a 1-8C aliph. hydrocarbon group and at least one of R6-R8 is always a group other than a 1-8C aliph. hydrocarbon group; n is 1-6) (e.g., gamma-methacryloyloxypropyltrimethoxysilane) are heated in a solvent to carry out condensation through dehydration to obtain a polysiloxane-contg. resin (A) which contains a polysiloxane macromonomer having at least two hydroxyl groups and/or alkoxyl groups per molecule and can be dissolved or dispersed in water. The component A is blended with water (B).

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention provides polysiloxane that can be cross-linked and cured at low temperatures without impairing its characteristics (for example, low surface tension, excellent water repellency, antifouling properties, etc.). , relates to an aqueous composition of a polysiloxane-containing resin having good stability in water.

PRIOR ART Many studies have been made to water-solubilize or water-disperse polysiloxane-containing resins, but they have various problems in practical vehicles, and improvements are desired. That is, for example, when a polysiloxane having RR RR as its main chain is reacted with a compound having a wood-philic functional group (hydroxyl group, ether group, etc.) such as ethylene glycol, the surface tension increases and the above-mentioned properties of the polysiloxane increase. This is not desirable because the characteristics are lost.

(2) A resin obtained by copolymerizing a polydialkylsiloxane having a polymerizable unsaturated bond with a polymerizable unsaturated monomer having an acid or a base does not have a crosslinking-reactive functional group such as a silanol group, The resin alone cannot be crosslinked. In addition, if this is copolymerized with a monomer having a hydroxyl group and crosslinked with melamine resin, etc., it must be heated and cured at a high temperature (approximately 140°C or higher), and the glass transition temperature of the cured coating film is low. This is undesirable because dirt and dust tend to adhere to it.

(3) Copolymerization of γ-(meth)acryloxyalkyltrialkoxysilane and the like with acid- or base-containing polymerizable unsaturated monomers exhibits the above characteristics of unit weight siloxanes. O.Q Problems to be Solved by the Invention The present invention aims to eliminate all of the deficiencies in (1) to (3) above.

Means for Solving the Problems The present inventor has proposed a polymerization method comprising a polysiloxane macromonomer having two or more hydroxyl groups and/or alkoxyl groups per molecule and a hydrophilic functional group. It has been discovered that a copolymer with a sexually unsaturated monomer is stably dissolved or dispersed in water and has excellent crosslinking and curing reactivity, leading to the present invention.

That is, the present invention has the following features: (1) General formula % Formula % () (wherein R1 is an aliphatic hydrocarbon group having 1 to 8 carbon atoms or a phenyl group, and R2, R3 and R4 are % to 4 carbon atoms)
represents an aliphatic hydrocarbon group or a hydrogen atom. ) Compound (A) represented by 70 to 99.999 mol% and the general formula (wherein, R5 is a hydrogen atom or a methyl group, R6, R
7 and R8 represent a hydroxyl group, an alkoxyl group having 1 to 4 carbon atoms, or an aliphatic hydrocarbon group having 1 to 8 carbon atoms. however,
Excluding the case where R6, R7 and R8 are all aliphatic hydrocarbon groups having 1 to 8 carbon atoms. n represents an integer of 1 to 6. ) is reacted with 30-0.001 mol % of compound (B) represented by
or) a polysiloxane-containing resin containing a polysiloxane macromonomer having two or more alkoxyl groups and having a number average molecular weight of about 400 to about 100,000, and which is made soluble or dispersible in water; and (11)
The present invention relates to an aqueous composition of a polysiloxane-containing resin containing water as a main component.

In the above general formulas CI) and (iI), the number of carbon atoms is 1 to 4
Examples of the aliphatic hydrocarbon group include linear or branched ones such as methyl group, ethyl group, propyl group, butyl group, etc.; In addition to the above-mentioned groups, examples thereof include linear or branched groups such as pentyl, hexyl, heptyl, and octyl groups. Examples of the alkoxyl group having 1 to 4 carbon atoms include straight-chain or branched methoxy, nidoxy, propoxy, and butoxy groups.

The polysiloxane macromonomer used in component (1) of the present invention has a main skeleton composed of siloxane bonds, and St of this main skeleton has an aliphatic hydrocarbon group, a phenyl group, a hydroxyl group,
The above compound (A) has an alkoxyl group, a polymerizable unsaturated bond, etc. bonded directly or indirectly.
and compound (B).

First, compound (A) is a compound represented by the general formula (i), and in the general formula, R1 is particularly preferably a methyl group or a phenyl group. R2, R3 and R4 may be all the same or may be partially or entirely different. Especially preferred as R2, R3 and R4 are methyl group, ethyl group, propyl group, butyl group and hydroxyl group. Preferred specific examples of compound (A) include methyltrimethoxysilane, phenyltrimethoxydisilane,
Examples include butyltrimethoxysilane, methyltriethoxysilane, methyltributoxysilane, phenyltrisilanol, methyltrisilanol, and the like. Among these, methyltrimethoxysilane, phenyltrimethoxysilane, phenyltrisilanol and the like are particularly preferably used.

Next, compound (B) is a compound represented by the above general formula (iI), and based on the general formula, R6, R
, and R8 may all be the same or partially or completely different. However, all of them must not be aliphatic hydrocarbon groups having 1 to 8 carbon atoms. R6, R7 and R8 are particularly preferably a methoxy group, an ethoxy group, or a hydroxyl group, and n is particularly preferably in the range of 2 to 4. Preferred specific examples of compound (B) include γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-acryloxypropyltrimethoxysilane, γ-methacryloxybutyltriethoxysilane, γ-
Examples include acryloxypropyltrisilanol.

Among these, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-acryloxypropyltrisilanol, and the like are particularly preferred.

The polysiloxane macromonomer is the above compound (A)
It is obtained by mixing and reacting the compound (B) with the compound (B). The mixing ratio of the rain shoe compound is 70 to 99.999 mol% of compound (A) based on the total amount of the rain shoe compound.
, preferably 90 to 99.9 mol%, more preferably,
The content of compound (B) is 30 to 0.001 mol%, preferably 10 to 0.1 mol%, more preferably 5 to 1 mol%. When the amount of compound (A) is less than 70 mol%, it becomes difficult to polymerize in a linear manner and tends to gel easily, whereas when it is more than 99.999 mol%, polymerization mainly occurs through condensation. This is not preferable because it reduces water resistance, chemical resistance, weather resistance, etc.

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

When compound (A) and compound (E) both have a hydroxyl group bonded to St, they can react even without a solvent, but the dehydration condensation reaction can be carried out using an organic solvent that can dissolve the rain shoe compound as a solvent under heating and stirring. is preferable. As the organic solvent, various solvents such as hydrocarbon, ester, ketone, alcohol, and ether can be used.

When compound (A) and/or compound (B) have an alkoxyl group bonded to St, it is preferable to hydrolyze them prior to condensation, and the hydrolysis is usually carried out 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, but it is preferably 0.1 mole or more per mole of alkoxyl group. When the amount is less than 0.1 mol, the reaction of the recompound may be reduced. The most preferred method is to use water as a solvent in large excess. Further, as the catalyst in this case, an acid catalyst or an alkali catalyst can be used, and specifically, hydrochloric acid, sulfuric acid, phosphoric acid, formic acid, acetic acid, propionic acid, acrylic acid, methacrylic acid, etc. can be used as the acid catalyst. Sodium hydroxide, triethylamine, ammonia, etc. can be used as an alkali catalyst. The amount of the catalyst added is about 0.0001 to 5% by weight, preferably 0.01 to 5% by weight, based on the total amount of the compound (A) and compound (B).
A range of 0.1% by weight is suitable.

The reaction temperature for the above reaction is usually about 20 to 180°C, preferably 50 to 120°C. Moreover, it is appropriate that the reaction time is usually about 1 to 40 hours.

In this reaction system, water-soluble organic solvents and those of alcohol type, ester type, ether type, ketone type, etc. can be preferably used, since they are effective in homogenizing the reaction system when heavy production is performed. The polymerization inhibitor is effective for preventing the unsaturated bonds contained in compound CB) from polymerizing during the reaction with compound (A), and specifically, hydroquinone, /\hydroquinone monomethyl ether, etc. Can be used.

In addition, in the production of polysiloxane-based macromonomers, there is no problem in adding tetraalkoxysilane, dialkyldialkoxysilane, etc. to the reaction system of compound (A) and compound (B). 20
They can be used in combination in mol% or less.

The main skeleton of the polysiloxane macromonomer (7) obtained by the reaction of compound (A) and compound (B) is composed of siloxane bonds, and the structure of the main skeleton is as follows:
Mainly long chain (i 1near), ladder (1add
er) type and a mixture thereof. These structures depend on the mixing ratio of compound (A) and compound (B),
It can be arbitrarily selected depending on the amount of water, acid catalyst, etc. added. A structure in which any one of R1, R2-R4, etc. of the general formulas CI) and (iI) is bonded to the Si of the siloxane bond, and the hydroxyl group and/or the number of carbon atoms is 1 to 1. The macromonomer has two or more functional groups such as alkoxyl groups (R2 to R4 and R6-Ra above) per molecule of the macromonomer.

Further, the polysiloxane macromonomer preferably has an average of 0.2 to 1.9 polymerizable unsaturated bonds per molecule, more preferably 0.6 to 1.4, It is most preferable to have 0.9 to 1.2 pieces. If there are too few polymerizable unsaturated bonds, the copolymerization reaction product of the macromonomer and vinyl monomer tends to become cloudy,
On the other hand, if there are too many polymerizable unsaturated bonds, there is a risk of gelation during the copolymerization reaction, which is not preferable.

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

(2) Various polysiloxane macromonomers are obtained by reacting under the same conditions while changing the proportions of compound (A) and compound (B) as appropriate.

(2) For each macromonomer obtained, various vinyl copolymers are synthesized by changing the proportion of non-functional vinyl monomer used.

■ The molecular weight distribution of the obtained vinyl copolymer was measured by gel permeation chromatography (G.

P, C,).

■ Even when the proportion of macromonomer and non-functional vinyl monomer used is changed, the peak molecular weight (molecular weight with the highest content) of the obtained copolymer is almost the same, and the distribution curve becomes a monopeak, resulting in a low molecular weight components (macromonomers that do not have unsaturated bond components) and high molecular weight components (
If no distribution of copolymers of macromonomers having two or more unsaturated bonds is observed, it can be said that the macromonomers used have an average of one polymerizable unsaturated bond per molecule.

■For other macromonomers, compound (A)
The number of moles used for compound (B) is [A], and the number of moles used for compound (B) is [
B], and the number of moles of compound (A) used to obtain a macromonomer having an average number of polymerizable unsaturated bonds is [Az].

When the number of moles of compound (B) is [B11], [B] /
[A] The average number of polymerizable unsaturated bonds in the macromonomer is determined by [B□]/[Al1.

For example, if a macromonomer with one polymerizable unsaturated bond is obtained in the case of compound (B)/compound (A) -1/20 (molar ratio), then compound (B)/compound (A) = 0 ．．
In the case of 9/20, a macromonomer having an average of 0.9 polymerizable unsaturated bonds is obtained.

The number average molecular weight of the polysiloxane system is usually about 400 to 100,000, preferably about 1,000.
The viscosity of a 50% by weight isobutyl acetate solution at 20° C. is preferably in the range of about 0.5 to 500 centipoise.

The polysiloxane-containing resin which is component [i) of the present invention is:
This is a copolymer containing the above-mentioned polysiloxane macromonomer and made water-soluble or water-dispersible.

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

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

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

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

First, in the above 1), examples of the carboxyl group-containing vinyl monomer include (meth)acrylic acid, crotonic acid, itaconbutyric acid, fumaric acid, maleic acid, and anhydrides thereof. The carboxyl group-containing vinyl monomer is
0.1 to 3 mol%, especially 0.3 to 3 mol% based on the total amount of the macromonomer and carboxyl group-containing vinyl monomer
Preferably, it is used in a proportion of 1.5 mol%. Also,
The number average molecular weight of the copolymer is about 3,000 to 200,000.
range is suitable. Examples of the carboxyl group neutralizer include trimethylamine, triethylamine, N
, N-dimethylethanolamine, ammonia, pyridine, N,N-diethylethanolamine, N,N-dibutylethanolamine, N-(β'-aminoethyl)ethanolamine, N-methylethanolamine, N-methyljetanol Examples include amine, morpholine, N-methylmorpholine, N-ethylmorpholine, cetylmorpholine, piperazine, and the like.

(meth)acrylamide, N-diethylaminoethyl (
meth)acrylamide, N-dimethylaminopropyl (
Examples include meth)acrylamide, N-dimethylaminoethyl (meth)acrylate, Nt-butylaminoethyl (meth)acrylate, and acrylamide.

These base-containing vinyl monomers have a content of 0.1 to
It is preferably used in a proportion of 3 mol %, especially 0.3 to 1.5 mol %.

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

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

The number average molecular weight of the copolymer consisting of a macromonomer and an epoxy group-containing vinyl monomer is 3,000 to 200,000.
is suitable.

Examples of the amines to be reacted with the epoxy groups in the copolymer include the above-mentioned amines, and examples of the neutralizing agent include the above-mentioned acids.

In 1) to 3) above, the copolymerization reaction of the siloxane-based macromonomer and various vinyl monomers can be carried out in the same manner as the usual synthesis method for acrylic resins or vinyl resins. Dissolved or dispersed in an organic solvent, in the presence of a radical polymerization initiator,
Copolymerization can be carried out by heating while stirring at a temperature of about 180°C. Further, in this copolymerization reaction, other vinyl monomers than those mentioned above may be copolymerized as necessary. Other vinyl monomers include, for example, esters of acrylic acid or methacrylic acid with monohydric alcohols (1 to 22 carbon atoms), hydroxyalkyl (2 to 10 carbon atoms) acrylates or methacrylates, acrylonitrile, methacrylatetril, vinyl Examples include toluene and styrene.

Furthermore, water-soluble organic solvents used in the copolymerization reaction include chlorinated hydrocarbons such as ethylene chlorohydrin and propylene chlorohydrin, valerolactone, ethylene glycol monomethyl ether acetate, diethylene glycol monomethyl ether acetate, and diethylene glycol monoethyl ether acetate. , esters such as methoxytriglycol acetate, methyl lactate, ethyl lactate, dioxolane, dioxane, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, diethylene glycol monoethyl ether, diethylene glycol diethyl ether,
Ethers such as diethylene glycol monobutyl ether and ethoxy triglycol, methanol, ethanol, allyl alcohol, n-, 1so-propanol,
Alcohols such as t-butanol, ethylene glycol, propylene glycol, butylene glycol, hexanediol, heptanediol, dipropylene glycol, triethylene glycol, tripropylene glycol, ketones such as acetone, acetonylacetone, diacetone alcohol, etc. Organic solvents that have almost infinite solubility in water include n-propatool, 1so-propatool, diacetone alcohol, ethylene glycol monobutyl ether, ethylene glycol monoethyl ether, acetic acid ethylene glycol monoethyl ether, etc. It is particularly preferable to use

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

The aqueous composition of the present invention is obtained as described above (
1) It can be easily obtained by adding water to a solution or dispersion of the component polysiloxane-containing resin in a water-soluble organic solvent. It is okay to mix them together.

Furthermore, after adding water, it is also possible to remove the organic solvent by distillation under reduced pressure.

The aqueous composition of the present invention is useful as a paint, a surfactant, a surface treatment agent, and the like. In addition, since the polysiloxane-containing resin which is the component [i) of the aqueous composition has a polysiloxane structure moiety according to the component (i) in the side chain, a functional group (hydroxyl group or alkoxyl group) per unit molecular weight can be obtained.
The amount is such that it does not deteriorate the storage stability of the aqueous composition, so there is no thickening or gelling, and it has the necessary amount of functional groups for crosslinking and curing, and is suitable for water solubilization or water dispersion. The functional group acts as a catalyst and has excellent curing properties at low temperatures. Furthermore, since the content of the polysiloxane structural portion can be increased, characteristics such as low surface tension, water repellency, antifouling properties, and adhesion to inorganic materials can be exhibited.

Therefore, when the aqueous composition of the present invention is used as a coating material, electrodeposition coating (cationic, anionic), spray coating, electrostatic coating, and dip coating are possible, and it also has the following effects.

1) Even when used alone, it has sufficient crosslinking properties and is excellent in film forming properties.

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

3) Creates a coating film with good weather resistance.

4) Excellent heat resistance.

5) Excellent stain resistance.

Example Examples of the present invention are shown below.

Example 1 Deionized water 1134g 60% hydrochloric acid 2g hydroquinone
1g of these mixtures were reacted at 80'O for 15 hours.

The obtained polysiloxane macromonomer had a number average molecular weight of 2,000, and had on average one vinyl group (polymerizable unsaturated bond) and four free hydroxyl groups per molecule.

300g of this macromonomer and 100g of styrene, 100g of acrylic acid, 500g of n-butyl acrylate, and 500g of azoisobutyronitrile.
A mixture of 20 g (polymerization catalyst) was added dropwise to 800 g of cellosolve at 120° C. to obtain a transparent copolymer. The number average molecular weight is approximately 20
It was 000.

Add 124g of dimethylaminoethanol to this, and add 3g of water.
000g to obtain a milky white water dispersion.

Even after storage at 50°C for 1 month, no changes such as gelation or decrease in film-forming properties were observed in this product.

The obtained composition was prepared into a dry coating film, which was applied to a glass plate to a film thickness of 10 p-, and dried at room temperature for 24 hours. The gel fraction of the coating film was 7%, and it had excellent adhesion, water repellency, stain resistance, weather resistance, and smoothness.

Example 2 Phenyltrisilanol 7800g (50mo
l) Toluene 4500g The mixture was reacted at 117°C for 3 hours and dehydrated. The number average molecular weight of the obtained polysiloxane macro-thonomer was 7.
000, with an average of 1 vinyl group per molecule and 5 to 10
It had 1 free hydroxyl group. This macromonomer i
A mixture of 00 g of N-dimethylamine ethylacrylamide, 100 g of methyl methacrylate, 600 g of 2-ethylhexyl methacrylate, and 10 g of azoisobutyronitrile was added dropwise into 800 g of butyl cellosolve at 120°C and polymerized to obtain a copolymer.

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

Even after storage at 50°C for one month, no changes such as gelation or decrease in film-forming properties were observed in this product.

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

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

After reacting 80 g of triethylamine with this product at 80° C. for 4 hours, 42 g of acetic acid and 4,000 g of water were added and dispersed in water to obtain an aqueous dispersion.

Even after storage at 50°C for one month, this product showed good stability without showing any changes such as gelation or decrease in film-forming properties.

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

Claims (1)

[Claims] (i) General formula▲There are mathematical formulas, chemical formulas, tables, etc.▼・・・・・・(I
) (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) 70-99.999 mol%
and general formula▲There are mathematical formulas, chemical formulas, tables, etc.▼・・・・・・(II) (In the formula, R_5 is a hydrogen atom or a methyl group, R_6
, R_7 and R_8 represent 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 aliphatic hydrocarbon groups having 1 to 8 carbon atoms is excluded. n represents an integer of 1 to 6. ) is reacted with 30 to 0.001 mol % of compound (B) represented by
or) a polysiloxane-containing resin containing a polysiloxane macromonomer having two or more alkoxyl groups and a number average molecular weight of about 400 to about 100,000, and which is made soluble or dispersible in water; and (ii) water. An aqueous composition of a polysiloxane-containing resin comprising as a main component.