JPS5819367A - Coating method - Google Patents

Abstract

PURPOSE:To form a coating film curing at normal temp. or low temp. with excellent resistance to weathering and adhesiveness, by adding a hardener-contg. thinner to a coating which contains a silyl group-contg. vinyl (co)polymer, just before its application. CONSTITUTION:A coating contg. a vinyl (co)polymer in which the main chain consists of a vinyl type polymer and a silyl group with at least one silicon group linked to a hydrolyzable group in one molecule[e.g. one of the formula (where X is a hydrolyzable group; R1 and R2 are H, 1-10C alkyl, aryl or aralkyl; n is 1, 2 or 3)]is contained at the terminal or in the side chain, is blended with a thinner contg. a hardener for the (co)polymer (e.g. tin octylate, phosphoric acid or KOH) just before application of the coating. The method produces a resin which cures at normal temp. or low temp., exhibits excellent weathering resistance and adhesiveness and is useful as paint and coating for metal plate, roof tile, wood and plastic surfaces.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a coating material containing a vinyl polymer or copolymer containing a hydrolyzable silyl group at the molecular end or side chain and whose main chain consists essentially of a vinyl type polymer. The present invention relates to a coating method in which a liquid pellet and a thinner (B) containing a hardening agent for the silyl group-containing vinyl type polymer or copolymer are mixed before coating. In particular, the present invention relates to an improved coating method that is as easy to work with as lacquer paints and can provide excellent cured coatings.

The present inventors have discovered that a vinyl-type polymer or copolymer having a hydrolyzable silyl group at the terminal or side chain has the characteristics of high gloss, weather resistance, and yellowing resistance that are characteristic of vinyl resins. The hydrolyzable silyl group improves adhesion to inorganic materials, and water, especially atmospheric water, crosslinks and hardens when heated at room temperature or relatively low temperature, forming a dense network structure, resulting in solvent and water resistance.・A patent application has been filed based on the discovery that the resin has excellent heat resistance, high hardness, and weather resistance (Japanese Patent Laid-Open Publication No. 54-36395).

The silyl group-containing vinyl type polymer or copolymer cures under moisture in the air or under heating conditions, even without a curing agent, to form a dense network structure, but curing is slow when heated at a relatively low temperature. . In order to speed up the curing rate, it is necessary to heat to a high temperature, and it is necessary to use a curing agent at room temperature or at a relatively low temperature.

Generally, when applying a paint that uses a hardening agent like this,
A method is used in which a main paint liquid containing resin or pigments is mixed with a curing agent, diluted with thinner to a viscosity that is easy to apply, and then painted. Generally, there are two types of paints that are used in this way.
It is called liquid paint. For example, the acrylic urethane paint currently most commonly used for automotive repair is a two-component paint. On the other hand, lacquer paints in which only the main paint liquid is diluted with thinner are generally referred to as I-liquid type paints.

Comparing the characteristics of one-component paint and two-component paint, the two-component paint is a non-polishing type that does not require a polishing process in the finishing process, has a high gloss, and has a good texture.
Although it is advantageous in terms of excellent solvent resistance and weather resistance, it is inferior to the one-component type in terms of workability and drying properties after application.

On the other hand, the one-component type requires a polishing process and is inferior to the two-component type in terms of physical properties of the coating, such as gloss, texture, solvent resistance, and weather resistance. For this reason, various attempts have been made to improve the workability and drying properties of two-component paints, which have excellent physical properties, to the same extent as those of the l-wave type. In order to improve drying properties, acrylic urethane paints containing nitrified cotton and cellulose compounds have been developed, and efforts have been made to improve the curing speed. In comparison, the gloss and texture of the painted surface are reduced. Possible methods for improving workability by converting a two-component paint into a single-component paint include mixing a hardening agent into the main paint liquid in advance, or mixing a hardening agent into paint thinner. However, with current two-component paints, the above method causes the main paint liquid to gel during storage, making it unusable as a paint. The latter method is used when the blending ratio of the paint main liquid and hardener-containing thinner changes, that is, for example, in the case of an acrylic urethane paint, the blending ratio of 10H groups in the base paint and -NGO groups in the hardener changes. As a result, the physical properties of the coating film change after painting, which is a disadvantage, and it has not been possible to convert it into one liquid to date.

By adding a curing agent to the silyl group-containing vinyl type polymer or copolymer of the present invention, as will be specifically shown in the examples below, the silyl group-containing vinyl type polymer or copolymer can be as good as or better than currently commercially available acrylic urethane paints. Creates a coating film with special characteristics,
The improved one-component coating method of the present invention using the polymer or copolymer has great advantages in terms of workability. As described above, the reason why the coating method of the present invention is different from known two-component paints and can be made into one component is because the main ingredient of the paint of the present invention has a hardening agent ratio compared to known two-component paints. This is because even a small amount is effective, and even if it varies over a wide range, it does not cause a practically large change in the physical properties of the cured coating film.

The resin used in the present invention has a main chain substantially composed of a vinyl polymer, and has at least one, preferably two or more, silicon groups bonded to a hydrolyzable group at the terminal or side chain in each molecule. of the silyl group (wherein,
I, an integer of 2.3). Hydrolyzable groups include halogen, alkoxy, acyloxy, ketoximate, amine, acid amide, aminooxy, mercapto, alkenyloxy groups, and the like.

The silyl group-containing vinyl type polymer or copolymer of the present invention can be produced by various methods, but the following method may be used: (1) Hydrosilylation reaction using a vinyl resin having a carbon-carbon double bond and hydrosilane. , and (2) copolymerization of a vinyl compound and a silyl compound having a polymerizable double bond are industrially effective methods. The method for producing the silyl group-containing vinyl type polymer or copolymer of the present invention will be explained in detail below.

■ The silyl group-containing vinyl type polymer or copolymer of the present invention can be easily produced by reacting a hydrosilane compound with a vinyl resin having a carbon-carbon double bond under the catalyst of a group (III) transition metal. . The hydrosilane compound used in the present invention has the following general formula.

(In the formula, (R,) is hydrogen or a monovalent hydrocarbon group selected from alkyl groups, aryl groups, and aralkyl groups having a carbon number of ! to 10, X is a hydrolyzable group, and n is an integer from 1 to 3. ) Specific examples of hydrosilane compounds included in this general formula include methyldichlorosilane, trichlorosilane,
Chyhalogenated silanes such as phenyldichlorosilane; alkoxysilanes such as methyljethoxysilane, methyldimethoxysilane, phenyldimethoxysilane, trimethoxysilane, triethoxysilane, methyldiacetoxysilane, phenyldiacetoxysilane, triacetoxysilane Acyloxysilanes such as methyldiaminoxysilane, triaminoxysilane, methyldiaminosilane, triaminosilane, bis(dimethylketoximate)methylsilane, bis(cyclohexylketoximate)methylsilane, methyldiisopropenooxysilane , various silanes such as triisopropenooxysilane.

The amount of the hydrosilane compound to be used can be any arbitrary amount relative to the carbon-carbon double bond contained in the vinyl resin, but it is preferably used in an amount of 0.5 to 2 times the mole. Although this does not preclude the use of a larger amount of silane, it will simply be recovered as unreacted hydrosilane.

Furthermore, in the present invention, halogenated silanes which are inexpensive basic raw materials and have high reactivity can be easily used as the hydrosilane compound. Silyl group-containing vinyl resins obtained using halogenated silanes harden rapidly at room temperature while emitting hydrogen chloride when exposed to the air. Since the halogenated silane has the problem of corroding substances and can only be practically used in limited applications, the silyl group-containing vinyl type polymer or copolymer obtained using the halogenated silane is further treated with other halogen functional groups. It is desirable to convert it into a hydrolyzable functional group. For example, it can be converted into an alkoxy, acyloxy, aminooxy, amino, acid amide, ketoximate, or mercapto group by the method shown in JP-A-54-91546.

The vinyl type polymer or copolymer used in method (1) of the present invention is not particularly limited, except for vinyl compounds containing hydroxyl groups, such as methyl acrylate, methyl methacrylate,
Acrylic acid, methacrylic acid esters such as ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate; acrylic acid, methacrylic acid,
Carboxylic acids such as itaconic acid and fumaric acid, acid anhydrides such as maleic anhydride, epoxy compounds such as glycidyl acrylate and glycidyl methacrylate, amine compounds such as diethylaminoethyl acrylate, diethylaminoethyl methacrylate, and aminoethyl vinyl ether, acrylamide, methacrylamide, itaconic acid diamide, α-ethylacrylamide, crotonamide,
Selected from amide compounds such as fumaric diamide, maleic diamide, N-butoxymethylacrylamide, N-butoxymethylmethacrylamide, acrylonitrile, iminol methacrylate, styrene, α-methylstyrene, vinyl chloride, vinyl acetate, vinyl propionate, etc. A resin containing a copolymer as a main component is suitable. When producing these vinyl compounds alone or as a copolymer, by radically copolymerizing a portion of allyl acrylate, allyl methacrylate, diallyl phthalate, etc., a carbon-carbon double layer for hydrosilylation reaction is created in the vinyl resin. It is possible to introduce the linkage at the end of the molecule or at the side chain. The amount of monomer necessary for this purpose can be arbitrarily determined depending on the number of silyl groups in the target resin. Furthermore, n-
The molecular weight can be adjusted by adding a chain transfer agent such as dodecyl mercaptan or [-dodecyl mercaptan. When polymerizing these vinyl compounds, 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.

In the present invention, a transition metal complex catalyst is required in the step of reacting a hydrosilane compound with a carbon-carbon double bond. As the transition metal complex catalyst, a complex compound of a Group I transition metal selected from platinum, rhodium, cobalt, palladium and nickel is effectively used. This hydrosilylation reaction is achieved at any temperature from 50 to 150°C, and the reaction time is about 1 to 10 hours.

(In the formula, (R7) is a monovalent hydrocarbon group selected from an alkyl group, an aryl group, and an aralkyl group having 1 to 10 carbon atoms,
R3 is an organic residue having a polymerizable double bond, X is a hydrolyzable group, and n is an integer of 1, 2.3. ) It is produced by radical polymerization of the silane compound shown in the following and various vinyl compounds.

Examples of the silane compound used in the present invention include CH=CH5i(QC)T8)3. CH2=CH5
iC18°CH2=CHC00(CH2)8 S i
(OCH3) B.

CH2=CHC00(CH2)3SiC13°CH=C
(CH)Coo(CH2)3Si(OCH3)3゜2 CH”C(CH)Coo(CH) S+C]g.

2 28 　　　0 111 　　0 111 etc.

These silane compounds are synthesized by various methods, but for example, acetylene, allyl acrylate, allyl methacrylate, diallyl phthalate and methyldimethoxysilane, methyldichlorosilane, trimethoxysilane, trichlorosilane are combined with a Group I transition metal or its It can be produced by reacting a compound in the presence of a catalyst.

As the vinyl compound used in the present invention, it is possible to use the compounds used in the synthesis of vinyl resin in the above method, but in addition to those described in method (2), 2-hydroxyethyl acrylate, 2-hydroxyethyl acrylate, 2- Hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-
Vinyl compounds containing hydroxyl groups such as hydroxypropyl methacrylate, 2-hydroxy vinyl ether, N-methylolacrylamide, Aronix 5700 (manufactured by Toagosei Co., Ltd.) are also possible.

Synthesis of these copolymers of vinyl compounds and silane compounds is carried out by ordinary solution polymerization methods.

A vinyl compound, a silane compound, a radical initiator, and a chain transfer agent such as n-dodecyl mercaptan or t-dodecyl mercaptan are added as necessary to obtain a silyl group-containing copolymer with an appropriate molecular weight at 50 to 150°C. React with. The molecular weight can also be controlled by changing the amount of catalyst and reaction temperature. 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 hydrolyzable groups of the silyl group-containing vinyl polymer or copolymer thus obtained can be converted, for example, by the method disclosed in JP-A-54-91546.

In this way, a silyl group-containing vinyl polymer whose main chain is substantially composed of a vinyl polymer and which has at least one silicon group bonded to a hydrolyzable group at the terminal or side chain in one molecule is produced. A polymer or copolymer is obtained.

The molecular weight of the silyl group-containing vinyl resin used in the present invention is not particularly limited, but from the viewpoint of physical properties and stability of the cured product, the molecular weight is 1000 to aoooo, particularly 2000 to +
A range of 0000 is preferred. Therefore, being able to paint with such a low molecular weight means that the amount of solvent used during spraying can be reduced, and as a so-called "high solid paint", it is socially expected to reduce the volatilization of solvent into the atmosphere and save resources. be.

In addition, the silyl group-containing vinyl resin contains ethylenically unsaturated organic monomers containing active hydrogen and acid anhydride groups such as carboxylic acid groups, hydroxyl groups, amine groups, and acid amide groups as exemplified above as copolymerization components. By including it, it is possible to further improve pot life and adhesion.

As the curing agent used in the present invention, it is possible to use compounds used as curing catalysts for general hydrolyzable silyl group-containing compounds, such as alkyl titanates; tin octylate, dibutyltin dilaurate, dioctyltin; Metal salts of carboxylic acids such as Shimatodo, lead octylate; Sulfide type and mercaptide type organotin compounds such as motuputyltin sulfide and dioctyltin mercaptide; Organotin oxides such as diptyl anchor oxide and dioctyltin oxide; Organotin oxide and ethyl silicate , ethyl silicate 40, dimethyl maleate, organic tin compounds by reaction with ester compounds such as dioctyl phthalate; acidic catalysts such as phosphoric acid, β-toluenesulfonic acid, phthalic acid; tetraethylenepentamine, triethylenediamine,
Amines such as N-β-aminoethyl-γ-aminopropyltrimethoxysilane; alkaline catalysts such as potassium hydroxide and sodium hydroxide; and the like alone or in mixtures are effective.

These curing agents are 0.001 parts by weight per 100 parts by weight of the resin.
- It is preferable to use it at 10 parts by weight.0 In the coating method of the present invention, when the main liquid of the paint is diluted with paint thinner CB) to a coating viscosity (about 15 seconds with a food cutter Ii4), the above ratio is obtained. It is necessary to dilute the main liquid and thinner appropriately with a solvent. The solvent used in this case may be a solvent that dissolves both the silyl group-containing vinyl resin and the curing agent, or a solvent that does not cause precipitation when mixed with other solvents even if it dissolves. , aliphatic hydrocarbons, aromatic hydrocarbons, halogenated hydrocarbons, alcohols, ketones, esters, ethers, alcohol esters, ketone alcohols, ether alcohols, used in coatings, etc. Ketone ethers, ketone esters, and ester ethers can be used. Further, when the main liquid of the paint containing a silyl group-containing vinyl resin contains an alkyl alcohol or a hydrolyzable ester, the viscosity of the paint can be suppressed and the stability can be improved.

As the alkyl alcohol, the number of carbon atoms in the alkyl is 1 to
10 alcohols are preferred, including methyl alcohol, ethyl alcohol, n-7' lobil alcohol, isopropyl alcohol, n-butyl alcohol, imbutyl alcohol, 5ec-butyl alcohol, tert-7'
Chyl alcohol, n-amyl alcohol, isoamyl alcohol, hexyl alcohol, octyl alcohol,
Cellosolve etc. are used.

Hydrolyzable esters include trialkyl orthoformates such as trimeflu orthoformate, triethyl orthoformate, tripropyl orthoformate, and tributyl orthoformate, and tetramethyl orthosilicate, tetraethyl orthosilicate, tetrapropyl orthosilicate, and tetrabutyl orthosilicate. A tetraalkyl orthosilicate is used.

The amount of solvent used in the paint main liquid and paint thinner (B) depends on the silyl group content, the molecular weight or composition of the vinyl resin,
If the ratio of the resin and the curing agent is different, the ratio of the resin and the curing agent is set so that when diluted with thinner until the coating viscosity is reached as described above, the ratio of the resin and the curing agent matches. For example, if a paint main liquid (5) with a solid content of 60% by weight can be coated with a solid content of 40% by weight, 50 parts by weight of B) is required for 100 parts by weight of (A). In this case, (B) is 100 parts by weight, or 25 parts by weight.
When it comes to parts by weight, the ratio of the silyl group-containing vinyl resin and the curing agent is 2 times, 1/2. Even when such a large change in ratio occurs, as seen in the examples, there is no practically problematic change in the physical properties of the coating film of the paint of the present invention, and it can be used as a one-component paint by the coating method of the present invention. It turns out that it is possible.

The paint used in the present invention cures at room temperature or low temperature and becomes a resin with excellent weather resistance and adhesion. ) and organic materials (wood, paper, cellophane, plastic, organic paint films, etc.) and are useful as paints and coatings for surfaces. In particular, since it can be cured at low temperatures, it is effective as anticorrosion paints for bridges, top coats, automobile repair paints, and paints for organic surfaces. Further, the top coat coated by the coating method of the present invention has excellent weather resistance, but it is also possible to add ultraviolet absorbers, antioxidants, etc. depending on the case. It is also possible to improve physical properties such as surface hardness and adhesion by adding a compound such as ethyl silicate or a silane coupling agent that can be co-condensed with the silyl group-containing vinyl polymer or copolymer of the present invention. It is.

It can also be blended with various resins currently used as paints and coatings, such as lacquer paints, acrylic lacquer paints, thermosetting acrylic paints, alkyd paints, melamine paints, and epoxy paints. These paints and coatings can be mixed with other substances in appropriate proportions to improve all their physical properties such as weather resistance and adhesion.

The paint used in the present invention can be applied by mixing various fillers, pigments, etc. into the main liquid paint (A). Various fillers and pigments can be used, such as various silicas, calcium carbonate, magnesium carbonate, glass fibers, various organic pigments, and inorganic pigments. In this way, it is useful not only for the above-mentioned uses, but also as a coating composition for aircraft, buildings, automobiles, glass, etc., a sealing composition, and a surface treatment agent for various inorganic and organic substances.

Next, the present invention will be specifically explained with reference to examples.

Example 1 In a 90F xylene solvent heated to 90°C, 30f styrene, 7f allyl methacrylate, 20f methyl methacrylate, 28f n-butyl methacrylate, 149. A solution of 2f of azobisisobutyronitrile dissolved in 4f of maleic anhydride and 1f of n-dodecyl mercaptan was added dropwise and reacted for 10 hours to obtain a molecular weight of +0000.
A vinyl polymer containing an allylic unsaturated group was obtained. In the infrared absorption spectrum of this product, an absorption due to a carbon-carbon double bond at 1648 m' and an acid anhydride absorption at 1780 (!l') were observed. Solvent was removed.

Obtained allylic unsaturated group-containing vinyl copolymer solution 1
6F trimethoxysilane 1. Of, chloroplatinic acid 0.0
A solution of 00FM dissolved in isopropanol was added and reacted under sealed conditions at 90° C. for 6 hours. In the infrared absorption spectrum of this product, the absorption at 1648 m-' disappeared, and a silyl group-containing vinyl type copolymer in which the carbon-carbon double bond of the allyl group was silylated was obtained.

Example 2 Heated to 120°C? Of butyl acetate, styrene 30f1 γ-methacryloxypropyltrimethoxysilane 15g, methyl methacrylate 29g1 methacrylic acid n
-Butyl 15f1 A solution of 6 g of azobisisobutyronitrile dissolved in butyl acrylate 18F was added dropwise and reacted for 10 hours, and the molecular weight was measured by GPC method. As a result, a silyl group-containing vinyl resin with a molecular weight of 6000 was obtained.

Example 3 Styrene 30 in 70f xylene heated to 90°C
g, γ-methacryloxyglobil trimethoxysilane 2
2g, methyl methacrylate 22y1 n-butyl methacrylate IfM, butyl acrylate 18f1 acrylamide 2f, n-butanol 10fs A solution of azobisin butyronitrile 2f dissolved in 6 g of n-dodecyl mercaptan was added dropwise and reacted for 10 hours to obtain a molecular weight of 4000. A silyl group-containing vinyl type copolymer was obtained.

White enamel was prepared by mixing the resin solution of Example 1.2 and the resin solution of Example 3 in a ball mill with the addition of titanium oxide in a ratio of 1:1 to the resin solid content. Furthermore, the hardening agent shown in Table 1 was added and mixed, diluted with xylene to a viscosity suitable for painting (15 seconds with Ford Kag 4), applied on a stained mild steel plate, and heated at 60°C for 40 minutes. The physical properties of the coating film were measured after several days. In addition, as a measure of the weather resistance of the white enamel, the gloss retention rate was measured using a sunshine weatherometer.

For comparison, the physical properties of a two-component acrylic urethane (Isamu Paint Co., Ltd. No-Imato Extra Base, 300IR) after the same treatment are shown.

×1. 5tann JF-9B: Manufactured by Sankyoki ■,
Mercaptide type organic tin compound *2. OTL Nidioctyltin dilaurate X3. DTL
Nidibutyltin difujilaurate X4 A-1120: manufactured by Nippon Unicar Co., Ltd. As with the silane coupling agent, there is no change in the physical properties of the coating film even if the amount of the curing agent changes to some extent, and it can be applied to the coating method of the present invention.

As an example of the painting method of the present invention, in the case of Example 2, Ford Cup l! ; 4 allows painting in about 15 seconds. In this case, the weight ratio of the main paint solution to the paint thinner is 2:1, but the examples show that the physical properties of the paint film do not change much even when used in a wide range of 1:1 to 4:1. .

Patent applicant Kanebuchi Chemical Industry Co., Ltd. Agent Patent Attorney Makoto Asano -

Claims (9)

[Claims] (1) From a vinyl-type polymer whose main chain is essentially a potash to a silyl-containing vinyl polymer or copolymer having at least one silicon group in each molecule bonded to a hydrolyzable group at the molecular end or side chain. A paint main liquid (4) containing a polymer and a thinner (B) containing a curing agent for a silyl group-containing vinyl polymer or copolymer are mixed before application. Painting method. (2) The silyl group of the silyl group-containing vinyl polymer or copolymer has the general formula (wherein, X represents a hydrolyzable group, (R1) and (R2
) represents hydrogen or an alkyl group having 1 to 10 carbon atoms, an aryl group, or an aralkyl group. n is an integer from 1 to 3. ) The coating method according to claim 1. (3) The coating method according to claim 1, wherein the paint main liquid (A) further contains alcohol and/or a hydrolyzable ester compound. (4) The coating method according to claim 1, wherein the silyl group-containing vinyl polymer or copolymer has a molecular weight of +000 to aooooo. (5) The coating method according to claim 1, wherein the silyl group-containing vinyl copolymer is a copolymer containing maleic anhydride and/or acrylamide as a copolymerization component. (6) The coating method according to claim 1, wherein the hydrolyzable group bonded to the silicon atom contained in the silyl group is an alkoxy group. (7) The coating method according to claim 1, wherein the curing agent is a carboxylic acid type organic tin compound. (8) The coating method according to claim 1, wherein the curing agent is a mercaptide-type organic tin compound having an Sn--S bond. (9) The coating method according to claim 1, wherein the curing agent is a sulfide type organic tin compound having a 5n-8 bond.