JPH01234468A - Reactive micro-gel composition - Google Patents

Abstract

PURPOSE:To obtain the title composition useful for coating compounds, providing a coating film having excellent solvent resistance, blocking resistance, wear resistance, etc., by curing with ultraviolet rays, heat, etc., by blending a specific silane compound, etc., with silica gel in a specific ratio and subjecting to co- condensation through hydrolysis. CONSTITUTION:(A) An organic silane compound (e.g., vinyltrimethoxysilane) containing a polymerizable unsaturated double bond and an alkoxysilane group and, if necessary, (B) an alkoxysilane-containing organic compound (e.g., tetramethoxysilane) except the component A are blended with (C) silica gel in the ratio of 1-100 pts.wt. component A and 1-400 pts.wt. component C based on 100 pts.wt. components A and B and subjected to co-condensation through hydrolysis to give the aimed composition.

Description

Detailed Description of the Invention [Objective of the Invention] (Industrial Field of Application) The present invention provides properties that can be cured by radiation such as ultraviolet rays or electron beams or by heat, resulting in properties such as solvent resistance, blocking resistance, abrasion resistance, and base material. Adhesion to materials 1 Provides a film with excellent surface hardness. This invention relates to reactive microgel compositions useful as paints, adhesives, etc.

(Prior art) Recently, there have been many efforts to improve the physical properties of coating films such as durability, thermal stability, and impact resistance by forming a moderate three-dimensional network structure within the particles of ultrafine polymer latex. . Furthermore, recent research has shown that polymers with a three-dimensional structure are not a uniform non-directional structure, but a non-uniform network structure, like a stone wall, embedded in the contour structure of areas with high cross-linking density. It is believed that.

For example, lacquer films, alkyd resins, polyester resins, etc. all have microgels in them, and there are cross-bonds between these microgel particles or between microgel particles and the continuous phase, forming a three-dimensional network structure. .

It is believed that this has been achieved.

In this way, ultrafine reactive microgels are considered to be an ideal morphological element, and the characterization of microgel particles 1 The relationship between crosslinking density within and between particles and film-forming properties, and control of the degree of crosslinking are important. and
Reactive microgels are also of great utility when applied to paints and adhesives.

Many methods have been reported for synthesizing these reactive microgels, including emulsion polymerization or emulsion copolymerization of polyfunctional crosslinking monomers such as divinylbenzene. When these crosslinking monomers were used, not only could a three-dimensional network structure be introduced into the two particles, but also a portion of the double bonds could remain on the particle surface due to effects such as steric hindrance.

Reactive microgels with so-called pendant vinyl groups can be directly synthesized.

However, due to the presence of 9-reactive double bonds, the microparticles tend to aggregate with each other, and it is also very difficult to contain a large amount of double bonds in the microparticles. Also,
If an attempt was made to introduce a large amount of double bonds into microparticles, this method had the disadvantage that it could only be achieved by a method that significantly lowered the reactivity by utilizing effects such as steric hindrance. For this reason, microgels with many double bonds such as acrylic groups that have high 2-reactivity are introduced.

I hadn't gotten it yet.

(Problems to be Solved by the Invention) The present invention improves various drawbacks of the above-mentioned conventional reactive microgels and introduces many polymerizable unsaturated double bonds such as acrylic groups. It is cured by radiation and heat such as ultraviolet rays and electron beams, and has solvent resistance, blocking resistance, abrasion resistance,
The present invention provides a reactive microgel composition that provides a film with excellent adhesion to substrates and surface hardness.

[Structure of the invention]

(Means for Solving the Problems) The present invention provides: (a) an organic silane compound having a polymerizable unsaturated double bond and an alkoxysilane group;
b) An organic silane compound having an alkoxysilane group other than the above (a), and (c) silica sol, based on 100 parts by weight of (a) and (b) in terms of solid content, 1 to 100 parts by weight of (a). This is a reactive microgel composition obtained by mixing 1 to 400 parts by weight of 1 to 400 parts by weight of 1 part to 400 parts by weight, and hydrolyzing and cocondensing the mixture.

In the present invention, (a) the organic silane compound having a polymerizable unsaturated double bond and an alkoxysilane group,
Vinyltrimethoxysilane, Vinyltriethoxysilane, Vinyltripropoxysilane, Vinyltributoxysilane, Vinyltri(methoxyethoxy)silane, T-
Methacryloxyethyltrimethoxysilane, γ-methacryoxyethyltriethoxysilane, γ-acryloxyethyltrimethoxysilane, γ-acryloxyethyltriethoxysilane.

γ-methacryloxypropyltrimethoxysilane.

γ-methacryloxypropyltriethoxysilane.

γ-acryloxypropyltrimethoxysilane.

T-acryloxypropyltriethoxysilane.

There are dimethylvinylmethoxysilane, dimethylvinylethoxysilane, methylvinyldimethoxysilane, methylvinyljethoxysilane, etc. (b) Organosilane compounds having an alkoxysilane group other than the above (a) that are used as necessary include: An organic silane compound having 1 to 4 alkoxysilane groups other than the above (a),
Examples of such organic silane compounds include tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane, methyltrimethoxysilane, methyltriethoxysilane, and methyltripropoxysilane.

Methyltributoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltripropoxysilane, ethyltributoxysilane, propyltrimethoxysilane, propyltriethoxysilane, propyltripropoxysilane, propyltributoxysilane, dimethyldimethoxysilane, dimethyl Jetoxysilane, dimethyldipropoxysilane, dimethyldibutoxysilane, diethyldimethoxysilane, diethyljethoxysilane, diethyldipropoxysilane. Diethyldibutoxysilane, methylethyltrimethoxysilane, methylpropyljethoxysilane, diphenyldimethoxysilane,
In addition to diphenyljethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, etc., organic silane compounds 1 commonly used as silane coupling agents
For example, γ-mercaptopropyltrimethoxysilane, γ
Examples include -glycidoxypropyltrimethoxysilane, T-glycidoxypropylmethyldimethoxysilane, and buttomized alkoxysilanes such as fluoroalkylalkoxysilane.

(a) and (b) are the sum of (a) and (b) 100
(a) is used in an amount of 1 to 100 parts by weight, preferably 50 to 90 parts by weight.

When the amount of (a) is less than 1 part by weight, the density of monopolymerizable unsaturated double bonds becomes small, and the curability of the resulting composition, solvent resistance after curing, blocking resistance, and abrasion resistance 1 surface The resulting composition becomes inferior in hardness, curability, solvent resistance after curing, and blocking resistance.

Friction Resistance 9 From the surface hardness point of view, it is better to have a higher density of monopolymerizable unsaturated double bonds.The larger the proportion of (a) in the mixture of (a) and (b), the better. In addition, when (a) is less than 50 parts by weight per 100 parts by weight of the sum of (a) and (b), the substrate of the cured film, especially metal and glass.

Adhesion to inorganic substrates such as concrete tends to decrease slightly, and when it exceeds 90 parts by weight, the cured film tends to become brittle and has poor impact resistance.

In the present invention, as the silica sol (c), those commercially available as an aqueous dispersion or a dispersion in a hydrophilic organic solvent such as alcohol can be used as they are, and specific examples of such commercial products include Cataloid SN ( Product name: Catalysts & Chemicals Industry ■), Snowtex O.

Snowtex OL (both product names 2 Nissan Chemical Industries)
Acidic water-based silica sol, Cataloid S-20L, etc.
(Product name, Catalyst Chemical Industry ■), Snowtex 20
．． Alkaline water-based silica gels such as Snowtex C, Snowtex N (both product names manufactured by Nissan Chemical Industries, Ltd.), Ludox AM (product name, manufactured by DuPont), Oscar (product name, Catalyst Chemicals (+1'4) series, etc.) Hydrophilic organic solvent-based silica sol etc. (c) Silica sol is used in a proportion of 1 to 400 parts by weight, preferably 2 parts by weight, based on 100 parts by weight of the sum of (a) and (b), in terms of solid content.
-200 parts by weight are mixed into (a) and (b). If the amount of (c) is less than 1 part by weight, the adhesion of the cured film to the substrate, especially inorganic substrates, will be poor, and if it exceeds 400 parts by weight, the resulting composition will have poor film-forming properties. become.

The above (a), optionally (b), and (c) are mixed in the above ratio, and optionally water and/or
A hydrophilic organic solvent, a surfactant, and a hydrolytic condensation catalyst are added, and the mixture is allowed to stand at room temperature or heated to undergo hydrolytic cocondensation to obtain a reaction microgel composition.

When using an aqueous silica sol as (c), the hydrolysis co-condensation proceeds without using a hydrolysis condensation catalyst, but in order to promote the hydrolysis co-condensation it is preferable to use a hydrolysis condensation catalyst. As the hydrolysis condensation catalyst, when (c) is an acidic aqueous silica sol, the acid catalyst is
When (c) is an alkaline aqueous silica sol, an alkali catalyst is used.

Furthermore, when a hydrophilic organic solvent-based silica sol is used as (c), water and a hydrolysis condensation catalyst must be added. The hydrolysis condensation catalyst in this case may be an acid catalyst or an alkali catalyst. Such hydrolysis condensation catalysts include sulfuric acid and hydrochloric acid.

Examples include organic acids and organic amines such as p-toluenesulfonic acid, sodium acetate, potassium acetate, triethanolamine titanate, tin octenoate, lead octenoate, octenoic acid, dibutyltin octate, ammonia, and acetic acid. These hydrolysis condensation catalysts.

9 usually 2 for 100 parts by weight of the sum of (a) and (b)
．． It is used in a proportion of 0 parts by weight or less, preferably 0.5 to 1.0 parts by weight.

Anionic and/or nonionic surfactants can be used to improve the stability of the resulting reactive microgel composition. Examples of such anionic surfactants include higher fatty acid salts.

Alkyl sulfate, alkylbenzene sulfonate, alkylnaphthalene sulfonate, alkyl sulfosuccinate, alkyldiphenyl ether disulfonate, alkyl phosphate polyoxyethylene alkyl or alkylaryl sulfate.

There are naphthalene sulfonic acid formalin condensates, special polycarboxylic acid type polymeric surfactants, etc. Nonionic surfactants include polyoxyethylene alkyl ether, polyoxyethylene alkyl allyl ether, polyoxyethylene derivatives, oxyethylene oxypropylene propylene Examples include tsukupolymer, sorbitan aliphatic ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene sorbitol fatty acid ester, glycerin fatty acid ester, and polyoxyethylene fatty acid ester.

(c) When the silica sol is an alkaline aqueous silica sol, or when an alkali catalyst is used as the hydrolysis condensation catalyst, it is preferable to use these surfactants in order to increase the stability of the resulting reactive microgel composition. . Surfactants are added before hydrolytic cocondensation. These surfactants.

Usually 20 parts by weight per 100 parts by weight of (a) and (b)
It is used in a proportion of less than 0.5 to 5 parts by weight, preferably 0.5 to 5 parts by weight. If more than 20 parts by weight is used, water resistance will be significantly reduced.

Furthermore, water and/or a hydrophilic organic solvent can be added before the hydrolytic co-condensation in order to control the microgel particle size in the resulting reactive microgel composition. That is, the particle size of the microgel can be controlled by changing the ratio of water and hydrophilic organic solvent contained in the monoreactive microgel composition.

An example of such a hydrophilic organic solvent is methanol.

Ethanol, propatool, isopropyl alcohol,
butanol, 5ec-butyl alcohol, ter
Examples include t-butyl alcohol, diaseptane alcohol, acetone, dioxane, methyl cellosolve, ethyl cellosolve, butyl cellosolve, glycols, carpitols, and the like.

The resulting reactive microgel composition may be optionally supplemented with pigments and dyes to the extent that they do not impede its performance.

Inorganic filler, conductive fine powder, water, hydrophilic organic solvent.

A thermal polymerization inhibitor and the like can be added.

The reactive microgel composition obtained in this way has radiation curability and pyrolytic radical curability, so after removing water and a hydrophilic organic solvent as necessary, it is irradiated with radiation such as ultraviolet rays or electron beams. It can be cured by heating or by heating. When curing using ultraviolet rays as radiation, it is preferable to use a photopolymerization initiator and, if necessary, a photopolymerization accelerator in terms of curing efficiency.When curing by heating, it is preferable to use a photopolymerization initiator and, if necessary, a photopolymerization accelerator. Therefore, it is preferable to use a thermal polymerization initiator.

As these photopolymerization initiators, photopolymerization accelerators, or thermal polymerization initiators, conventionally known ones can be used.

Furthermore, a hydrolytic condensation catalyst can be further added to the reactive microgel composition thus obtained to carry out the condensation reaction of alkoxysilane.

(Example) The present invention will be explained below with reference to Examples. In the examples, 2 parts means parts by weight, and 1% means % by weight.

Production Examples 1 to 15 A mixture having the composition shown in Table 1 was thoroughly mixed and reacted at the reaction temperature shown in Table 1 for the time shown in Table 1 to obtain microgel composition A-
I got 0.

In Table 1, the symbols are as follows.

γ-MPTMS: γ-methacryloxypropyltrimethoxysilane γ-APTMS: γ-acryloxypropyltrimethoxysilane VTMS: Vinyltrimethoxysilane γ-GPTMS
: γ-Glycidoxypropyltrimethoxysilane TES : Tetraethoxysilane MTMS : Methyltrimethoxysilane Nortex 0: Solid content 20% Ludox AM: Solid content 30% Oscar 1432: Solid content 30% IPA: Isopropyl alcohol DBSNa: )' Sodium decylbenzenesulfonate POENPE: Polyoxyethylene nonylphenyl ether Examples 1 to 8 and Comparative Examples 1 to 3 Microgel composition A obtained in Production Examples 1, 3, 5.7 to 9 and 10 to 15, C, E, G~■ and ni~
0 on a glass plate to a dry film thickness of 10 μm, heat-dried at 80°C for 20 minutes, and then coated with 10M
The coating film was cured by irradiation with a rad electron beam. Table 2 shows the results of evaluating the solvent resistance, pencil hardness, and adhesion to a glass plate of each of the obtained cured coating films.

The evaluation method and evaluation results are as follows.

■Solvent resistance: Evaluation was made by rubbing with a cloth impregnated with methyl ethyl ketone and the number of times of back-and-forth rubbing until a change occurred in the coating film.

◎: 100 times or more, ○ near 0 times or more but less than 100 times.

△: 40 times or more and less than 70 times, X: 2 times or more and less than 40 times,
XX: 1 time. ◎ and ○ were considered to be passed.

■Pencil hardness = evaluated using "Mitsubishi Uni" (trade name, manufactured by Mitsubishi Pencil G Kiku). -: Not evaluated. Those with hardness of H8 or higher were accepted.

■Adhesion to glass plate: 2mm vertically and 2mm horizontally on the coating surface
The substrate was cut into 25 pieces, peeled off using cellophane adhesive tape, and evaluated based on the number of remaining pieces.

◎: 25 remaining pieces, ○: 23 to 24 remaining pieces, △: 10 to 22 remaining pieces, ×: 1 to 9 remaining pieces, XX: remaining number O
No, -2 rating. ■ and ○ were considered passed.

Examples 9 to 14 and Comparative Examples 4 to 6 Production Examples 1, 2, 4.6, 10. and microgel compositions A, B, D, and F obtained in 12-15.

2-hydroxy-2-methylpropiophenone, which is a photopolymerization initiator, was added to each of J and L~0 at a ratio of 1 part to 100 parts of the solid content of the microgel composition, and the mixture was placed on a glass plate. After applying the film to a dry film thickness of 10 μm and drying it at 80°C for 20 minutes, the output was 80 W/a.
The coating film was cured by irradiating ultraviolet rays for 30 minutes using a F15 cm meral halide lamp.

Table 3 shows the results of evaluating each of the obtained cured coating films in the same manner as in Example 1.

Examples 15-21 and Comparative Examples 7-9 Production Example 1. 3. 4. 7. 9. and 11-15
Microgel compositions A, C, D, and G obtained in .

0.5 parts of benzoyl peroxide, which is a thermal polymerization initiator, was added to 100 parts of the solid content of the microgel composition to each of ■, and ~0, and a dry film thickness was obtained on a glass plate. Apply to a thickness of 10 μm.

The coating film was cured by heating at 150° C. for 30 minutes. Table 4 shows the results of evaluating each of the obtained cured coating films in the same manner as in Example 1.

Table 2 Table 3 Table 4 [Effects of the Invention] According to the present invention, many polymerizable unsaturated double bonds such as acrylic groups were introduced. It is cured by radiation such as ultraviolet rays and electron beams and by heat, and has solvent resistance and blocking resistance.

It has now become possible to obtain a reactive microgel composition that provides a film with excellent abrasion resistance and adhesion to substrates 9 and surface hardness.

Claims (1)

[Claims] 1, (a) an organic silane compound having a polymerizable unsaturated double bond and an alkoxysilane group, optionally (b) an organic silane compound having an alkoxysilane group other than the above (a), and (c) silica sol , in terms of solid content (a)
and (b) 1 to 10 parts by weight of (a)
0 parts by weight, (c) is mixed in a ratio of 1 to 400 parts by weight,
A reactive microgel composition formed by hydrolytic co-condensation.