JPH0230350B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a paint containing a silyl group-containing vinyl copolymer, and particularly relates to weather resistance, curing properties (drying properties, hardness, solvent resistance, etc.), adhesion, impact resistance, Erichsen properties, and storage properties. This invention relates to a moisture-curable coating material containing a silyl group-containing vinyl copolymer with excellent stability and pigment dispersibility. The present inventors discovered that a vinyl resin containing a silyl group having a hydrolyzable group at the terminal or side chain is
In addition to the excellent characteristics of vinyl resins such as high gloss, weather resistance, and discoloration resistance, the hydrolyzable silyl group improves adhesion to inorganic substances, and moisture, especially moisture in the atmosphere, can be used at room temperature. The company discovered that it can undergo a crosslinking reaction, forming a dense network structure, resulting in a resin with excellent solvent resistance, water resistance, heat resistance, high hardness, and weather resistance, and has previously filed a patent application. (Japanese Patent Publication No. 56-36395). As a result of further investigation, the present inventors found that (A) 50% by weight or less of aromatic vinyl monomer, (B) 20% by weight or less of vinyl monomer having a polar group, (C) Formula

5 to 35% by weight of a silane compound represented by the formula, (D) 20 to 95% by weight of an acrylic ester or methacrylic ester that does not have a polar group, (A), (B),
The linear random copolymer obtained by polymerizing components (C) and (D) as essential components has storage stability,
The inventors have discovered that this resin can be an excellent resin that is well-balanced in terms of pigment dispersibility and various physical properties after crosslinking and curing, leading to the present invention. In the present invention, when the aromatic vinyl monomer (A) component exceeds 50% by weight, the surface gloss of the cured resin improves, but the weather resistance decreases. In addition, when the monomer content is relatively small from 0% by weight, when the copolymer of the present invention is used as a metallic base paint, the viscosity of the resin solution increases and the compatibility with the metallic clear paint is good. It is valid. The reason why the vinyl monomer having a polar group as the component (B) of the present invention is set to 20% by weight or less indicates a range that does not reduce the storage stability of the resulting curable copolymer. That is, by including a vinyl monomer having a polar group, the pigment dispersibility of the resulting curable copolymer, the solvent resistance of the cured resin, and the adhesion to organic substances are surprisingly improved. %, storage stability and water resistance of the cured resin decrease. 5 to 35% by weight of the silane compound as component (C) of the present invention
The reason for this is that it shows a well-balanced range of storage stability, curing properties, and adhesion. That is, when the content of the silane compound is less than 5% by weight, the curability of the copolymer becomes slow and the solvent resistance of the resulting cured resin is completely poor.
Moreover, when the amount exceeds 35% by weight, the curability improves, but the storage stability decreases. Furthermore, as the amount of the silane compound increases, the internal stress of the cured resin increases, and the adhesiveness of the cured resin rapidly decreases. The reason why the acrylic ester or methacrylic ester of component (D) of the present invention is set at 20 to 95% by weight is as follows.
This is to improve the weather resistance and other physical properties of the cured resin. Acrylic esters and methacrylic esters improve the weather resistance of the resins contained as copolymerization components, and at the same time, by varying the acrylic esters and methacrylic esters, it is possible to control the Tg of the resulting copolymer. This makes it possible to adjust dryness, hardness, impact resistance, Erichsen properties, etc. The linear vinyl-type random copolymer containing a silyl group in the present invention comprises the above components (A), (B), (C),
Obtained by radical polymerization of (D). A linear copolymer here means that when a 5 g sample is heated in 100 c.c. of a refluxing solvent such as toluene for about 30 minutes, the sample will dissolve and not form a gel. . Component (A) includes styrene, α-methylstyrene, α-chlorostyrene, etc., with styrene being particularly preferred. (B) Components include acid amides such as acrylamide, methacrylamide, itaconic acid diamide, α-ethylacrylamide, crotonamide, fumaric acid diamide, maleic acid diamide, N-butoxymethylacrylamide, N-butoxymethylmethacrylamide; 2- Hydroxy vinyl ether, N-methylol acrylamide, 2
- Hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, Aronix 5700 (Toagosei Co., Ltd.)
Compounds containing hydroxyl groups such as acrylic acid, methacrylic acid, itaconic acid, fumaric acid, maleic anhydride; Epoxy compounds such as glycidyl acrylate and glycidyl methacrylate; Diethylaminoethyl acrylate, diethylaminoethyl methacrylate,
Amino compounds such as aminoethyl vinyl ether; etc., especially acrylamide, methacrylamide, N-methylolacrylamide,
2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, and 2-hydroxypropyl methacrylate are preferred. (C) As a component, the formula

[Formula] (wherein R ₁ is an alkyl group having 1 to 10 carbon atoms, an aryl group,
a monovalent hydrocarbon group selected from aralkyl groups,
_R2 is an organic residue having a polymerizable double bond, X is a hydrolyzable group, and n is an integer of 1, 2, or 3)
Hydrolyzable groups include halogen, alkoxy, acyloxy, ketoximate, amino, acid amide, aminooxy, mercapto,
Contains alkenyloxy groups, etc., specifically

[Table] etc. As the hydrolyzable group, an alkoxy group is preferable. Especially as component (C)

[Formula] is preferred. These silane compounds are synthesized by various methods, but for example, acetone, allyl acrylate, allyl methacrylate, diallyl phthalate, etc. and methyldimethoxysilane, methyldichlorosilane, trimethoxysilane, trichlorosilane, etc. are synthesized using a group transition metal catalyst. It can be produced by the following reaction. Examples of component (D) include acrylic esters such as n-butyl acrylate and methacrylic esters such as methyl methacrylate. The silyl group-containing curable copolymer of the present invention is synthesized by a conventional solution polymerization method. The molecular weight can be controlled by selecting an appropriate polymerization temperature and amount of radical initiator, and optionally using a chain transfer agent such as n-dodecyl mercaptan or t-dodecyl mercaptan. The polymerization temperature can be selected between 50 and 150°C. A solvent may or may not be used, but when used, it is preferable to use a non-reactive solvent such as ethers, hydrocarbons, and acetic esters. The silyl group-containing vinyl copolymer thus obtained can have hydrolyzable groups exchanged, for example, by the method disclosed in JP-A-54-91546. The molecular weight of the silyl group-containing vinyl copolymer in the present invention is not particularly limited, but it is determined based on the storage stability of the resin, high solidity when the resin is used as a paint, and the sticky feeling of a cured paint film. , the lower the molecular weight, the better, 1000-30000,
Preferably, the range is 3000 to 20000. When the silyl group-containing vinyl copolymer of the present invention is exposed to the atmosphere, it forms a network structure at room temperature and hardens. When curing, a curing accelerator may or may not be used depending on the curing conditions, but it is more effective to use a curing accelerator for curing at relatively low temperatures. be. Examples of curing accelerators include alkaline accelerators such as sodium hydroxide and potassium hydroxide; alkyl titanates; acidic compounds such as phosphoric acid, p-toluenesulfonic acid, and phthalic acid; aliphatic diamines such as ethylenediamine and hexanediamine, and diethylenetriamine. , aliphatic polyamines such as triethylenetetramine and tetraethylenepentamine, alicyclic amines such as piperidine and piperazine, aromatic amines such as metaphenylenediamine, ethanolamines, triethylamine, and as a curing agent for epoxy resins. _{Amine compounds such as various modified amines used ; _ _} n―C ₄ H ₉ ) ₂ Sn (OCOCH=CHCOOC ₄ H ₉ ―
n) ₂ , (n-C ₈ H ₁₇ ) ₂ Sn (OCOC ₁₁ H ₂₃ -n) ₂ , (n-C ₈ H ₁₇ ) ₂ Sn (OCOCH=CHCOOCH ₃ ) ₂ , (n-C ₈ H ₁₇ ) ₂ Sn (OCOCH=CHCOOC ₄ H ₉ -
n) ₂ , (n-C ₈ H ₁₇ ) ₂ Sn (OCOCH=CHCOOC ₈ H ₁₇ -
carboxylic acid-type organic tin compounds such as iso) ₂ and Sn(OCOC ₈ H ₁₇ -n) ₂ . (n-C ₄ H ₉ ) ₂ Sn (SCH ₂ COO), (n-C ₄ H ₉ ) ₂ Sn (SCH ₂ COOC ₈ H ₁₇ -iso) ₂ , (n-C ₄ H ₁₇ ) ₂ Sn (SCH ₂ COO), (n-C ₈ H ₁₇ ) ₂ Sn (SCH ₂ CH ₂ COO), (n-C ₈ H ₁₇ ) ₂ Sn
(SCH ₂ COOCH ₂ CH ₂ OCOH ₂ S), (n-
C ₈ H ₁₇ ) ₂ Sn
(SCH ₂ COOCH ₂ CH ₂ CH ₂ CH ₂ OCOH ₂ S), (n-C ₈ H ₁₇ ) ₂ Sn (SCH ₂ COOC ₈ H ₁₇ -iso) ₂ ,
(n-C ₈ H ₁₇ ) ₂ Sn (SCH ₂ COOC ₁₂ H ₂₅ -n) ₂ , Mercaptide-type organotin compounds such as.

【formula】

【formula】

Sulfide-type organotin compounds such as [Formula], organotin oxides such as (n-C ₄ H ₉ ) ₂ SnO, (n-C ₈ H ₁₇ ) ₂ SnO, and (n-C ₄ H ₉ )SnO, (n
-C ₈ H ₁₇ ) Reaction of organotin oxides such as SnO with ester compounds such as ethyl silicate, ethyl silicate 40, dimethyl maleate, diethyl maleate, dioctyl maleate, dimethyl phthalate, diethyl phthalate, and dioctyl phthalate. Organotin compounds such as products, etc. are used. The curing accelerator is a vinyl copolymer containing silyl groups.
0.01 to 10 parts by weight per 100 parts by weight, preferably 0.1
~8 parts by weight are used. The silyl group-containing vinyl copolymer of the present invention can be cured at room temperature or low temperature, and the cured product has excellent physical properties such as adhesion and weather resistance. It is useful as a paint, coating agent, primer, adhesive, etc. for the surfaces of aluminum plates, galvanized steel plates, roof tiles, slate plates, etc.) and organic materials (wood, paper, cellophane, plastic, organic paint films, etc.). In particular, since it can be cured at low temperatures, it is effective as a corrosion preventive coating for bridges, etc., as a top coat, as a paint for automobile repair, as a paint for organic surfaces, and the like. When used in such applications, it can be diluted with a solvent. The solvents used include aliphatic hydrocarbons, aromatic hydrocarbons, halogenated hydrocarbons, alcohols, ketones, esters, ethers, alcohol esters, which are used in general paints, coatings, etc. Ketone alcohols, ether alcohols, ketone ethers, ketone esters, and ester ethers can be used. Furthermore, when these solvents contain an alkyl alcohol or a hydrolyzable ester, storage stability can be improved. The alkyl alcohol is preferably an alcohol in which the alkyl has 1 to 10 carbon atoms, such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, sec-butyl alcohol, tert-butyl alcohol, n -Amyl alcohol, isoamyl alcohol, hexyl alcohol, octyl alcohol, cellosolve, etc. are used. Hydrolyzable esters include trialkyl orthoformates such as trimethyl orthoformate, triethyl orthoformate, tripropyl orthoformate, and tributyl orthoformate, and tetramethyl orthosilicate, tetraethyl orthosilicate, tetrapropyl orthosilicate, and tetrabutyl orthosilicate. Tetraalkyl orthosilicate, and methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, γ- Hydrolyzable organosilicon compounds such as methacryloxypropyltrimethoxysilane and γ-mercaptopropyltrimethoxysilane are used. Furthermore, when used in such applications, the silyl group-containing vinyl copolymer of the present invention can be made into a single component by adding a curing accelerator and, in some cases, a solvent, making it extremely easy to work with. It brings great benefits. The conditions for converting into one liquid are the silyl group-containing vinyl copolymer of the present invention, a curing accelerator, and
Depending on the case, this can be achieved by appropriately selecting a solvent. Currently, paints, coating agents, primers,
It can be blended with various resins used as adhesives, such as lacquer paints, acrylic lacquer paints, thermosetting acrylic paints, alkyd paints, melamine paints, epoxy paints, etc. in appropriate proportions. It can be used by mixing with the silyl group-containing vinyl copolymer of the present invention, such as ethyl silicate, to improve the physical properties such as adhesion and weather resistance of these paints and coating agents. It is also possible to improve physical properties such as surface hardness by adding suitable compounds. The silyl group-containing vinyl copolymer of the present invention can contain various fillers, pigments, and the like. Fillers and pigments include various silicas, calcium carbonate, titanium oxide, iron oxide, glass fiber,
Commonly used fillers and pigments can be used, such as aluminum powder, carbon black, and organic pigments such as phthalocyanine, azo, triphenylmethane, quinoline, and anthraquinone. In this way, not only the above-mentioned applications, but also aircraft,
It is also useful as a coating composition, a sealing composition, and a surface treatment agent for buildings, automobiles, glass, etc. Next, the present invention will be specifically explained using examples. Example A Examples 1 to 4 and Comparative Examples 1 to 4 were polymerized for 10 hours under the conditions of the monomer, initiator, chain transfer agent, solvent, and polymerization temperature shown in Table 1, and silyl groups with the molecular weights also shown in Table 1 were obtained. A containing vinyl copolymer solution was obtained. As for the composition, the Tg was kept roughly constant at about 50 to 60°C.

[Table] To the silyl group-containing vinyl copolymer solutions obtained in Examples 1 to 4 and Comparative Examples 1 to 4, 2 parts by weight of dibutyltin dilaurate was added per 100 parts by weight of the copolymer, and the mixture was diluted with xylene. Food cup (No. 4) diluted to 15 seconds and painted on a polished mild steel plate (rinsed with No. 320 Kenma paper and dried), and baked melamine alkyd for yellowing resistance measurements. After baking at 60°C for 30 minutes, the coating was left at room temperature for 7 days and the physical properties of the coating were measured. The results are shown in Table 2.

【table】

[Table] As shown in Table 1, when the amount of styrene in component (A) is large, yellowing becomes worse, and when the amount of γ-methacryloxypropyltrimethoxysilane in component (C) is small, curability (pencil hardness, resistance (gasoline resistance, temperature resistance) is poor,
Also, if the amount is too large, the adhesion will decrease. Furthermore, adhesion is improved by copolymerizing the monomer containing a polar group as component (B). Example B The resin solutions obtained in Example 1 and Comparative Examples 3 and 4 and titanium oxide were mixed in a ball mill at a ratio of 1:1 to the resin solid content to obtain white enamel. The obtained white enamel was diluted with xylene to a solid content concentration of 65% by weight, and was heated at 50℃ under sealed conditions to improve pigment dispersibility.
The storage stability was investigated. Further, to the solutions obtained in Example 4 and Comparative Example 4, 2 parts by weight of dibutyltin dilaurate per 100 parts by weight of the silyl group-containing vinyl copolymer and tetramethyl orthosilicate were added to 100 parts by weight of the copolymer. Add 10 parts by weight, solid content concentration 40
Dilute with xylene to % by weight and store at 50℃ under sealed condition.
The storage stability was investigated. The results are shown in Table 3.

[Table] As shown above, pigment dispersibility is improved by including a monomer having a polar group as component (B), and storage stability increases as the amount of γ-methacryloxypropyltrimethoxysilane as component (C) increases. decreases. It is also understood that the silyl group-containing vinyl copolymer of the present invention can be made into one liquid with a curing agent.

Claims (1)

[Claims] 1 (A) Aromatic vinyl monomer 50% by weight or less (B) Vinyl monomer having a polar group 20% by weight or less (C) Formula (In the formula, R ₁ is an alkyl group having 1 to 10 carbon atoms,
A silane represented by a monovalent hydrocarbon group selected from an aryl group and an aralkyl group, R ₂ is an organic residue having a polymerizable double bond, X is an alkoxy group, and n is an integer of 1, 2, or 3. Compound 5-35% by weight (D) Acrylic ester or methacrylic ester without polar group 20-95% by weight or more (A), (B), (C) and (D) components are polymerized as essential components. Moisture-curable paint containing a linear random copolymer obtained by. 2. The paint according to claim 1, wherein the aromatic vinyl monomer is styrene. 3. The paint according to claim 1, wherein the silane compound is γ-methacryloxypropyltrimethoxysilane. 4. The paint according to claim 1, wherein the vinyl monomer having a polar group is a compound having an acid amide group. 5. The paint according to claim 1, wherein the vinyl monomer having a polar group is a compound having a hydroxyl group.