JPH0625369A - Aqueous silicone-modified resin - Google Patents

Abstract

PURPOSE:To obtain the subject resin providing a coating film having high polysiloxane segment concentration on the surface and excellent water repellency, comprising a film-forming copolymer having a unit from a specific silicone compound and a unit from an ethylenic unsaturated monomer. CONSTITUTION:The objective resin comprises a film-forming copolymer having a unit from a silicone compound selected from compounds of formula I and formula II (X is 3-(meth)acryloxypropyl; Y is COOH, SO3H, etc.; R<1> is phenyl or 1-6C alkyl; (a) is 1.5-20; (b) is 0.5-3; (c) is 1-10) and a unit from an alpha, beta- ethylenic unsaturated monomer. The copolymer is preferably obtained by subjecting the alpha, beta-ethylenic unsaturated monomer to emulsion polymerization by using the neutralized silicone compound as a surfactant. The compound of formula I is obtained by hydrosilylating phenyl-methylhydrogenpolysiloxane with an organic functional group-containing alkene and modifying the reactional product with an acid anhydride.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an aqueous resin, and more particularly to an aqueous silicone modified resin.

[0002]

2. Description of the Related Art Silicone resin can form a coating film having good water repellency and weather resistance, but it is difficult to form a coating film having high mechanical strength by itself, and therefore, epoxy resin, polyester resin and It has been devised to use it for modification of acrylic resin and the like so as to exhibit the above-mentioned characteristics. In particular, the silicone-modified acrylic resin has both properties as an acrylic resin capable of forming a coating film having high mechanical strength and properties as a silicone resin capable of forming a coating film having good water repellency and weather resistance. , High availability.

From the viewpoint of preventing environmental pollution, the above silicone-modified acrylic resin is also required to be water-based. For example, JP-A-2-150475 discloses an aqueous silicone-modified acrylic resin composed of a polymer of an organopolysiloxane macromonomer and an α, β-ethylenically unsaturated monomer. This aqueous silicone-modified acrylic resin is synthesized by emulsion polymerization because the organopolysiloxane macromonomer has no hydrophilic functional group and is highly hydrophobic.

However, in emulsion polymerization, since a surfactant is used, the outer peripheral portion of the resin emulsion particles has high hydrophilicity. Therefore, the film made of the above-mentioned water-based silicone-modified acrylic resin cannot exhibit sufficient water repellency due to the segment because the polysiloxane segment concentration in the surface layer portion is low. An object of the present invention is to allow a coating film having good water repellency to be formed with respect to an aqueous silicone modified resin.

[0005]

The aqueous silicone resin of the present invention comprises a repeating unit of at least one silicone compound selected from the group of silicone compounds represented by the following average composition formulas (1) and (2). And α, β
A film-forming copolymer containing repeating units of ethylenically unsaturated monomers.

[0006]

[Chemical 2]

************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************ of the present invention, the silicone compounds used in the present invention are those represented by the following average composition formulas (1) and (2), respectively. These silicone compounds may be used alone or in combination of two or more.

[0008]

[Chemical 3]

In these silicone compounds, the group X
Is a 3-acryloxypropyl group or 3-methacryloyl
It is a xypropyl group. These silicone compounds are
Due to the unsaturated bond portion contained in the group X,
It can be copolymerized with the α, β-ethylenically unsaturated monomer.
In addition, in the silicon-compound, the group Y is -CO.
OH, -SO₃H and -NR² ₂Selected from the group consisting of
It is a monovalent substituent containing at least one group. This
Una group Y may be linear or branched.
Yes. Note that -NR ² ₂R contained in the group is an organic group containing hydrogen
It is a residue. This organic residue is not particularly limited
However, for example, methyl group, ethyl group, propyl group,
Isopropyl group, butyl group, sec-butyl group, t-butyl
It is an alkyl group such as a chill group. The group Y is included in it
-COOH, -SO₃H, -NR² ₂Depending on each group of
Or by neutralizing these groups, the resin of the present invention
Can be rendered water-based.

Two or more groups X and Y may be contained in one silicone compound. In the silicone compound, R is a phenyl group or an alkyl group having 1 to 6 carbon atoms. From an industrial viewpoint, R is preferably a methyl group or a phenyl group. Two or more types of R may be contained in one silicone compound. For example, a silicone compound having a dimethylsiloxane unit as a main unit and containing a diphenylsiloxane unit or a methylphenylsiloxane unit can be used as an α, β-
The reactivity and compatibility with the ethylenically unsaturated monomer are further improved.

In the silicone compound, a, b,
c is the following range, respectively.

[0012]

[Equation 1]

When a is less than 1, the water repellency of the silicone compound is not utilized. On the other hand, when it exceeds 20, the reactivity and compatibility with the α, β-ethylenically unsaturated monomer decrease. When b is less than 0.5, the copolymerization ratio of the silicone compound and the α, β-ethylenically unsaturated monomer decreases, and unreacted silicone compound is likely to remain,
The physical properties of the copolymer resin may deteriorate. On the other hand, when b exceeds 3, gelation of the system occurs during polymerization of the silicone compound and the α, β-ethylenically unsaturated monomer, and a copolymer resin cannot be obtained. If c is less than 1,
It becomes difficult to impart sufficient water content to the resin of the present invention.
On the other hand, when C exceeds 10, the viscosity of the compound increases and the reactivity and compatibility with the α, β-ethylenically unsaturated monomer decrease.

The silicone compound represented by each of the average composition formulas (1) and (2) may have repeating units arranged in a block form or a random form. Specific examples of the silicone compound used in the present invention include:
It is as follows. In the structural formulae, Me represents a methyl group and Ph represents a phenyl group. A silicone compound represented by the average composition formula (1).

[0015]

[Chemical 4]

A silicone compound represented by the average composition formula (2).

[0017]

[Chemical 5]

[0018]

[Chemical 6]

The silicone compound used in the present invention is
For example, it can be manufactured as follows. A silicone compound represented by the average composition formula (1). First, a silicone compound represented by the following average composition formula (3) is synthesized. .

[0020]

[Chemical 7]

This silicone compound can be synthesized by a hydrosilylation reaction of phenylmethyl hydrogen polysiloxane and an organic functional group-containing alkene. Here, phenylmethyl hydrogen polysiloxane is
For example, it can be synthesized by the following reaction (A).

[0022]

[Chemical 8]

The desired silicone compound can be synthesized from phenylmethyl hydrogen polysiloxane, for example, by the following reaction (B).

[0024]

[Chemical 9]

In the case of synthesizing the specific examples (a), (b) and (c) of the silicone compound represented by the above average composition formula (1), the following silicone compound is prepared according to the above-mentioned synthetic method. (A ') and (b') are synthesized.

[0026]

[Chemical 10]

When these silicone compounds (a ') and (b') are modified with an acid anhydride, an amine compound or a sulfonic acid compound, the desired silicone compounds (a), (b) and (c) are obtained. Is obtained. Specifically, it is as follows.

[0028]

[Chemical 11]

A silicone compound represented by the average composition formula (2). First, a silicone compound represented by the following average composition formula (4) is synthesized. In the formula, X, Z, R ¹ ,
a and b are the same as in the case of the average composition formula (3).

[0030]

[Chemical 12]

This silicone compound comprises, for example, tetramethyldisiloxane, 3-methacryloxypropylmethyldimethoxysilane, and water reacted with an acid catalyst, and octametylcyclotetrasiloxane and octaphenylcyclotetrasiloxane. It can be synthesized from an alkali equilibrium product by a trifluoromethanesulfonic acid equilibration reaction. This synthetic route is as in (C) below.

[0032]

[Chemical 13]

In the case of synthesizing the specific examples (e), (f) and (g) of the silicone compound represented by the above-mentioned average composition formula (2), the following silicone compound is prepared according to the above-mentioned synthetic method. (E ') and (f') are synthesized.

[0034]

[Chemical 14]

When these silicone compounds (e ') and (f') are modified with an acid anhydride, an amine compound or a sulfonic acid compound, the desired silicone compounds (e), (f) and (g) are obtained. Is obtained. Specifically, it is as follows.

[0036]

[Chemical 15]

The specific examples (d) and (h) of the silicone compound represented by the average compositional formula (2) are the same as those in the synthetic route (C) of the silicone compound represented by the average compositional formula (4). , And compound (II) can be synthesized by adding the following allyl compounds (i) and (ii), respectively.

[0038]

[Chemical 16]

Α, β-ethylenically unsaturated monomer The α, β-ethylenically unsaturated monomer used in the present invention includes acrylic monomers, styrene, α-methylstyrene, α-methylstyrene dimer, Examples thereof include itaconic acid, itaconic anhydride, maleic acid, maleic anhydride, vinyl acetate, allyl acetate, vinyltrimethoxysilane, vinyltriethoxysilane, vinylmethyldimethoxysilane and vinylmethyldiethoxysilane.

Among these, as the acrylic monomer,
Methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, n-butyl acrylate, n-butyl methacrylate, i-butyl acrylate, i-butyl methacrylate, t-butyl acrylate, t-methacrylate. Butyl, t-butyl methacrylate, acrylic acid 2
-Ethylhexyl, 2-ethylhexyl methacrylate,
Lauryl acrylate, lauryl methacrylate, phenyl acrylate, phenyl methacrylate, benzyl acrylate, bundyl methacrylate, cyclohexyl acrylate, cyclohexyl methacrylate, cyclohexenyl methyl acrylate, cyclohexenyl methyl methacrylate, 2-hydroxyethyl acrylate , Methacrylic acid 2
-Hydroxyethyl, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 4-hydroxybutyl acrylate, 4-hydroxybutyl methacrylate, 2-hydroxyethyl acrylate or 2-hydroxyethyl methacrylate and ε-caprolactone Adduct (for example, Placcel FM1 manufactured by Daicel Chemical Industries Ltd.), acrylic acid, methacrylic acid, 2-acrylamido-2-methylpropanesulfonic acid, acid phosphoxypropyl methacrylate, glycidyl acrylate, glycidyl methacrylate, acrylic Acid 3,4-epoxycyclohexyl or 3,4-epoxycyclohexyl methacrylate (for example, Cyclomer M-100 and Cyclomer A-200 manufactured by Daicel Chemical Industries, Ltd.), 3-trimethyl acrylate Xysilylpropyl, 3-trimethoxysilylpropyl methacrylate, 3-triethoxysilylpropyl acrylate, 3-triethoxysilylpropyl methacrylate, 3-dimethoxymethylsilylpropyl acrylate, 3-dimethoxymethylsilylpropyl methacrylate, acrylic Acid tributyltin, methacrylate tributyltin, acrylamide, methacrylamide, acryloyl isocyanate, methacryloyl isocyanate, acrylic acid 2-isocyanate, methacrylic acid 2
-Isocyanate etc. can be illustrated.

The α, β-ethylenically unsaturated monomers may be used alone or as a mixture of two or more kinds. Copolymer Resin The copolymer resin of the present invention comprises a repeating unit of the above silicone compound and a repeating unit of the above α, β-ethylenically unsaturated monomer. This copolymer resin is a graft polymer in which a branch polymer made of a silicone compound is bonded to a trunk polymer made of an α, β-ethylenically unsaturated monomer.

Such a copolymer resin can be obtained by a general polymerization method such as solution polymerization, suspension polymerization, bulk polymerization or emulsion polymerization of a silicone compound and an α, β-ethylenically unsaturated monomer. At this time, the mixing ratio of the silicone compound and the α, β-ethylenically unsaturated monomer is 1 to 80% by weight of the silicone compound (more preferably 1 to 3%).
0% by weight), 99, α, β-ethylenically unsaturated monomer
It is preferably set to 20% by weight (more preferably 99 to 70% by weight). Silicone compound is less than 1% by weight and α, β-ethylenically unsaturated monomer is 99% by weight
When it exceeds, the characteristics of the silicone compound are difficult to develop. On the other hand, when the silicone compound content exceeds 80% by weight and the α, β-ethylenically unsaturated monomer content is less than 20% by weight, the mechanical strength of the coating film decreases, which is not preferable.

The copolymer resin used in the present invention is
Repeating units other than those based on the above-mentioned silicone compound and α, β-ethylenically unsaturated monomer may be contained. The copolymer resin can be provided as an emulsion-type or water-soluble type resin by selecting the production method described below. And the molecular weight of this copolymer resin is
In the case of emulsion type, the weight average molecular weight is 10,000 to 200.
10,000, preferably 100,000 to 1,000,000, and the water-soluble type has a number average molecular weight of 1,000 to 100,000, preferably 2,000 to
It is 20,000. When the molecular weight is out of the above range, the copolymer resin cannot exhibit good film-forming properties. The molecular weight is GP for both emulsion type and water-soluble type.
It is a value calculated in terms of styrene by C (gel permeation chromatography) method. Method for producing copolymer resin: The resin of the present invention is a method of emulsion polymerizing an α, β-ethylenically unsaturated monomer using a neutralized silicone compound as a surfactant, the silicone compound and α,
It can be produced by two methods of copolymerizing with a β-ethylenically unsaturated monomer and then neutralizing.

As the neutralizing agent, when the silicone compound contains a COOH group and a SO ₃ H group, monomethylamine, dimethylamine, trimethylamine, ammonia,
Monoethanolamine, diethanolamine, dimethylethanolamine and the like are used. When the silicone compound contains an NR ² ₂ group, formic acid, acetic acid, propionic acid, lactic acid, sulfuric acid, phosphoric acid, nitric acid, hydrochloric acid or the like is used.

In the copolymerization reaction of the silicone compound and the α, β-ethylenic monomer, the unsaturated bond contained in the X group of the silicone compound during the polymerization reaction between the α, β-ethylenically unsaturated monomers. As a result, a branch polymer formed of a silicone compound is introduced into the trunk polymer formed of the α, β-ethylenically unsaturated monomer. Utilization of water-based silicone modified resin The water-based silicone modified resin of the present invention is used for various coating materials such as coating materials for paints, coating materials for electronics such as electrically insulating coating resins, coating materials for biomedical materials, molding materials, and medical materials. It is used as a film forming material.

At this time, various additives, solvents, pigments and the like may be added to the water-based silicone modified resin, if necessary. As the solvent, ethylene glycol monomethyl ether, ethylene glycol monobutyl ether,
2,2,4-trimethylpentadiol-1,3-monoisobutyrate, diethylene glycol mono-tert
-Butyl ether, ethylene glycol monoethyl ether acetate, ethylene glycol monoisobutyl ether acetate, toxol, benzyl alcohol, butyl carbitol acetate, hexylene glycol,
Solvents such as toluene, xylol, and turpentine are used. Further, a curing agent or a cross-linking curing accelerator can be added to the aqueous silicone modified resin. Examples of the curing agent include melamine formaldehyde resin and blocked isocyanate. In addition, examples of the cross-linking curing accelerator include p-toluene sulfonate and dodecylbenzene sulfonate.

Since the polysiloxane segment of the water-based silicone-modified resin of the present invention has hydrophilicity, a coating film having a high polysiloxane segment concentration in the surface layer and good water repellency can be formed.

[0048]

Example 1 In a reaction vessel equipped with a stirrer, a reflux condenser, a thermometer, a dropping funnel and a nitrogen gas introducing pipe, 350 parts by weight of water and 20 parts by weight of a silicone compound represented by the following structural formula (5) were added. And 2.2 parts by weight of dimethylethanolamine were charged and kept at 80 ° C. Then, in this reaction vessel, a mixed liquid of 40 parts by weight of methyl methacrylate and 40 parts by weight of 2-ethylhexyl methacrylate, and 0.5 parts by weight of 4,4′-azobis-4-cyanovaleric acid and dimethylethanolamine. A mixed solution of 0.4 parts by weight and 50 parts by weight of water was separately added dropwise at a constant rate over 2 hours.

When this was kept at 80 ° C. for 3 hours and then cooled, a water-dispersed silicone-grafted acrylic resin was obtained. The obtained resin had a particle diameter of 120 nm, a weight average molecular weight of 900,000 and a nonvolatile content concentration of 19.7 wt%.

[0050]

[Chemical 17]

Example 2 In a reaction vessel similar to that used in Example 1, 235 parts by weight of water, 20 parts by weight of a silicone compound represented by the following structural formula (6), and 2.2 parts by weight of dimethylethanolamine were used. Was charged and maintained at 80 ° C. Then, 100 parts by weight of butyl methacrylate and 0.5 parts by weight of 4,4′-azobis-4-cyanovaleric acid, 0.4 parts by weight of dimethylethanolamine and 50 parts by weight of water were mixed in this reaction vessel. The solution was added dropwise at a constant rate over 2 hours separately. This is 3 at 80 ℃
When the mixture was kept warm for a while and then cooled, a water-dispersed silicone-grafted acrylic resin was obtained. The obtained resin had a particle diameter of 60 nm, a weight average molecular weight of 1,000,000, and a nonvolatile content concentration of 34.6% by weight.

[0052]

[Chemical 18]

Example 3 A reaction vessel similar to that used in Example 1 was charged with 235 parts by weight of water, 20 parts by weight of a silicone compound represented by the following structural formula (7), and 2.3 parts by weight of lactic acid. , 80 ° C. Then, 100 parts by weight of butyl methacrylate, 0.5 parts by weight of 2,2′-azobis (2-amidinopropane) hydrochloride and 50 parts by weight of water were separately added at a constant rate over 2 hours. When this was kept at 80 ° C. for 3 hours and then cooled, a water-dispersed silicone graft acrylic resin was obtained. The resulting resin has a particle size of 70
nm, the molecular weight was 900,000 in terms of weight average molecular weight, and the nonvolatile content was 34.1% by weight.

[0054]

[Chemical 19]

Example 4 A reaction vessel similar to that used in Example 1 was charged with 350 parts by weight of water, 20 parts by weight of a silicone compound represented by the following structural formula (8), and 2.3 parts by weight of lactic acid. , 80 ° C. Then, a mixed liquid of 60 parts by weight of 2-ethylhexyl methacrylate and 20 parts by weight of t-butyl methacrylate, and 4,4′-azobis-4-cyanovaleric acid 0.5
Parts by weight and dimethylethanolamine 0.4 parts by weight and water 5
A mixed solution with 0 part by weight was separately added dropwise at a constant rate over 2 hours. When this was kept at 80 ° C. for 3 hours and then cooled, a water-dispersed silicone graft acrylic resin was obtained. The obtained resin had a particle size of 120 nm, a weight average molecular weight of 950,000 and a nonvolatile concentration of 19.3% by weight.

[0056]

[Chemical 20]

Example 5 A reaction vessel similar to that used in Example 1 was charged with 350 parts by weight of water, 20 parts by weight of a silicone compound represented by the following structural formula (9), and 2.3 parts by weight of lactic acid. , 80 ° C. Then, a mixed solution of 60 parts by weight of 2-ethylhexyl methacrylate and 20 parts by weight of t-butyl methacrylate, and 0.5 parts by weight of 2,2′-azobis (2-amidinopropane) hydrochloride and 50 parts by weight of water. 2 mixed solution
It was added dropwise at a constant velocity separately over time. When this was kept at 80 ° C. for 3 hours and then cooled, a water-dispersed silicone graft acrylic resin was obtained. The resulting resin has a particle size of 1
The average molecular weight was 20 nm, the weight average molecular weight was 1,000,000, and the nonvolatile content concentration was 19.3% by weight.

[0058]

[Chemical 21]

Example 6 In a reaction vessel similar to that used in Example 1, 350 parts by weight of water and silicone compound 20 of the following structural formula (10) were used.
Parts by weight and 2.3 parts by weight of lactic acid were charged and kept at 80 ° C. And a mixed solution of 60 parts by weight of 2-ethylhexyl methacrylate and 20 parts by weight of t-butyl methacrylate,
A mixed solution of 0.5 parts by weight of 2,2′-azobis (2-amidinopropane) hydrochloride and 50 parts by weight of water was added dropwise at a constant rate separately over 2 hours. When this was kept at 80 ° C. for 3 hours and then cooled, a water-dispersed silicone graft acrylic resin was obtained. The obtained resin had a particle size of 120 nm, a weight average molecular weight of 900,000 and a nonvolatile concentration of 19.3% by weight.

[0060]

[Chemical formula 22]

Example 7 In a reaction vessel similar to that used in Example 1, 50 parts by weight of ethoxypropanol was charged and kept at 105 ° C. And butyl methacrylate 70 parts by weight, methacrylic acid 1
0 parts by weight, silicone compound 2 of the following structural formula (11)
A mixed solution of 0 parts by weight and 1.0 parts by weight of t-butylperoxy-2-ethylhexanoate was added dropwise at a constant rate over 3 hours. Then, the reaction system is kept warm at 105 ° C. and the dropping is completed 3
After 0 minutes, a mixed solution of 5 parts by weight of ethoxypropanol and 0.5 parts by weight of t-butylperoxy-2-ethylhexanoate was further added dropwise over 30 minutes. This is 105 ℃
When ethoxypropanol was distilled off after keeping the temperature for 2 hours, a silicone-acryl graft resin solution was obtained. The obtained resin had a number average molecular weight of 9000 and a nonvolatile content concentration of 79.5% by weight.

[0062]

[Chemical formula 23]

To the resulting resin, 4.2 parts by weight of dimethylethanolamine and 300 parts by weight of water were added and dispersed in water to obtain a water-dispersed silicone-grafted acrylic resin having no turbidity. The nonvolatile content of this resin was 30% by weight. Comparative Example 1 400 parts by weight of water, 8 parts by weight of dodecylbenzenesulfonic acid, 80 parts by weight of butyl acrylate, 0.5 parts by weight of 4,4′-azobis-4-cyanovaleric acid, 0.4 parts by weight of dimethylethanolamine. And a dimethylsiloxane macromonomer having a molecular weight of about 1000 (Silaplane FM
-0711: 20 parts by weight of Chisso Co., Ltd.) was stirred by using a homomixer and emulsified and dispersed. 80 this dispersion
After keeping the temperature at 0 ° C. for 5 hours and then cooling, a water-dispersed silicone-grafted acrylic resin was obtained. The obtained resin has a particle size of 200 nm and a molecular weight of 90 by weight average molecular weight.
The nonvolatile concentration was 19.1% by weight. Comparative Example 2 In a reaction vessel similar to that used in Example 1, 350 parts by weight of water and 8 parts by weight of dodecylbenzenesulfonic acid were charged and kept at 80 ° C. Then, a mixed solution of 60 parts by weight of 2-ethylhexyl methacrylate and 20 parts by weight of t-butyl methacrylate, and 0.5 parts by weight of 2,2′-azobis (2-amidinopropane) hydrochloride and 50 parts by weight of water. The mixed solution of was added dropwise at a constant rate separately over 2 hours. When this was kept at 80 ° C. for 3 hours and then cooled, a water-dispersed acrylic resin was obtained. The resulting resin has a particle size of 60
nm, the molecular weight was 900,000 in terms of weight average molecular weight, and the nonvolatile concentration was 19.5% by weight. Water repellency test The water repellency of the coating films made of the resins obtained in Examples 1 to 7 and Comparative Examples 1 and 2 was examined.

In each of Examples 1 to 6 and Comparative Examples 1 and 2, each resin was applied to a thickness of 100 μm and the temperature was adjusted to 60 ° C.
And dried for 24 hours to form a coating film. In addition, in Example 7, a water-soluble melamine resin as a curing agent was added at a ratio of 1/4 of the resin solids to a thickness of 100 μm and baked at 140 ° C. for 30 minutes to obtain a coating film. It was Table 1 shows the results of measuring the contact angles of water droplets for each of the examples and the comparative examples. The larger the contact angle, the better the water repellency.

[0065]

[Table 1]

[0066]

EFFECTS OF THE INVENTION In the water-based silicone modified resin of the present invention, since the polysiloxane segment has hydrophilicity, a coating film having a high polysiloxane segment concentration in the surface layer and good water repellency can be formed.

Claims (1)

[Claims] 1. A repeating unit comprising at least one silicone compound selected from the group of silicone compounds represented by the following average composition formulas (1) and (2), respectively:
An aqueous silicone-modified resin comprising a film-forming copolymer containing a repeating unit of an α, β-ethylenically unsaturated monomer. [Chemical 1]