JPH04106172A - Coating composition - Google Patents

Abstract

PURPOSE:To obtain the title composition improved in film hardness, water resistance, stain resistance, etc., by mixing a specified binding reaction component and a skeleton composition consisting of a partial condensate of an organoalkoxysilane, a tetraalkyl silicate, and a vinyl resin. CONSTITUTION:100 pts.wt. (in terms of organoalkoxysilane) partial condensate of an organoalkoxysilane of formula I (wherein R is a 1-8C organic group; R<1> is 1-5C alkyl) is mixed with 1-30 pts.wt. tetraalkyl silicate of formula II (wherein R<2> is 1-4C alkyl) and 10-150 pts.wt. vinyl resin having in the polymer molecule at least one silyl group having an Si atom attached to a hydrolyzable group at the end or on the side chain to give a skeleton composition (A). 0.01-30 pts.wt. aluminum compound of formula III (wherein R<3> and R are each alkyl; R<5> is R<3> or alkoxy; n is 0 to 3) (partial hydrolyzate thereof) is mixed with 0.1-10 pts.wt. oligomer of a dimeric reactive siloxane comprising pentamethyldisiloxane having a functional group at one end and/or tetramethyldisiloxane having functional groups at both ends to give a binding reaction component (B). Component A is mixed with component B.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides high hardness, high gloss, A paint composition suitable for forming a thick, crack-free coating film with a high proportion of inorganic components that imparts stain resistance and has excellent water resistance, weather resistance, heat resistance, abrasion resistance, chemical resistance, etc. Regarding.

[Conventional technology]

The surface of industrial products such as building materials made of non-horizontal materials such as metals, ceramics, and ceramic moldings is coated with a composition consisting of a silicone compound and silicone-modified AC97L' resin to give a design effect. Efforts are being made to improve wear resistance, chemical resistance, corrosion resistance, weather resistance, etc.

A variety of baking-type alkoxide materials have been developed, including organic 7A with a silicone skeleton and silicone as the base material, but although they have excellent hardness, stain resistance, and adhesion, In reality, it is difficult to obtain a crack-free coating film with a thickness of 10 microns or more, and the alkali resistance is poor.

In addition, although two-component, room-temperature-curing acrylic-silicone paints based on silicone-modified acrylic resins and featuring high weather resistance are being widely used in the steel, architecture, and building materials fields, their moisture-curing properties lead to poor curing. The lack of hardness is noticeable, and unlike the good stain resistance during long-term outdoor exposure,
This results in problems such as scratches.

[Problem to be solved by the invention]

The present invention solves the above conventional problems, and its purpose is to coat the surfaces of metals, ceramics, glass, cement, ceramic moldings, plastics, wood, paper, fibers, etc. An object of the present invention is to provide a coating composition having the following properties.

■ A coating composition with high hardness, stain resistance, and high gloss that forms a coating film with excellent adhesion to the substrate; ■ A coating with excellent chemical resistance, boiling water resistance, and solvent resistance. A coating composition capable of forming a film; ■Does not require long-term curing treatment at high temperatures when forming a film;
A coating composition that does not cause cracks even when forming a relatively thick coating; ■ A coating that has excellent weather resistance and does not discolor, blister, or crack even when exposed outdoors for a long time. A paint composition that can be formed.

[Means to solve the problem]

The coating composition of the present invention has the following formula: (a) - Formula R51 (OR') - (where k is 1 carbon number
-8 organic group (R1 represents an alkyl group having 1 to 5 carbon atoms) 100 parts by weight of an S-component ta compound of an organoalkodisilane (R1 represents an alkyl group having 1 to 5 carbon atoms) in terms of organoalkoxysilane, and (b) - Formula 5i (OR' )= (in the formula, k" represents an alkyl group having 1 to 4 carbon atoms) and 1 to 30 parts by weight of a tetrasilicate, and (c) a hydrolyzable group bonded to the terminal or side chain. 10 to 150 parts by weight of a silyl group-containing vinyl resin having at least one silicon atom-containing silyl group in the polymer molecule are mixed to form a skeleton composition, and (d) - formula AA'(ORtsun(OR( R')=C)i
cOR, -n (wherein R is an organic group having 1 to B carbon atoms, R
1 and Ro are at least one member selected from the group of aluminum compounds represented by Ill'FILM, R'' is an alkyl group or an alkoxy group, and n is an integer of 0 to 3, and partial hydrolysates of the aluminum compounds. 0.0
1 to 30 parts by weight, and (e) an oligomer of a dimeric reactive siloxane having a functional group at one end of pentamethyldisiloxane and/or an oligomer of a dimeric reactive siloxane having a functional group at both ends of tetramethyldisiloxane. 0.1-1 of oligomer
0 parts by weight as a binding reaction component, thereby achieving the above object.

The partial compound [component (a)] of the organoalkodisilane used in the composition of the present invention has the general formula R51 (OR')
It is obtained by condensing an alkoxy group-containing silicon compound represented by , under hydrolysis conditions.

In the above formula, R is an organic group having 1 to 8 carbon atoms, and Ro is an alkyl group having 1 to 5 carbon atoms. If the number of carbon atoms in R and Ro is too large, the rate of hydrolysis described below will be extremely slow, and in some cases, hydrolysis will hardly proceed.

The above R includes alkyl groups such as methyl group, ethyl group, propyl group, butyl group; 7-aryl groups such as phenyl group, tolyl group and xylyl group; dichlorofurkyl group such as cyclohexyl group; other γ-chloroprobyl groups, Examples include a vinyl group, a dipropyl group in r-glycidide, a γ-methacryloyloxyglobyl group, a γ-mercabutobrovir group, a γ-7 minobrovir group, and a 3,4-epoxycyclohexyl group. Examples of R1 include methyl group, ethyl group, propyl group, butyl group, and acetyl group. Examples of such organoalkoxysilane include methyltrimethoxysilane, methyltriethoxysilane, methyltripropoxysilane, methyltributoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, propyltrimethoxysilane, propyltriethoxysilane, Phenyltrimethoxysilane, phenyltriethoxysilane, vinyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, r-glycidoxypropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, T-methacryloxy trimethoxysilane, γ-7 minobrobyl trimethoxysilane,
Examples include 3,4-epoxycyclohexylethyltrimethoxysilane. Preferably, methyltrimethoxysilane and/or methyltriethoxysilane are used.

These organoalkoxysilanes can be used alone or in combination of two or more.

The production reaction of the partial condensate obtained by condensing the above organoalkoxysilane under hydrolysis conditions can be carried out by a production method known per se, that is, by adding water to the above organoalkoxysilane and condensing it. can.

The tetraalkyl silicate [component (b)] represented by the general formula 5l(OR')4 used in the composition of the present invention improves the hardness of the cured coating film obtained by applying the composition, or Improves adhesion between paint film and base material. In particular, it works to improve water resistance.

In the above formula, R1 represents an alkyl group having 1 to 4 carbon atoms.

Such 7~+ lucilicates include tetramethyV
Silicate, tetraethyl silicate, tetra-n-propyl silicate, tetra-i-propyl silicate,
Examples include tetra-n-butyl silicate, tetra-1-butyl silicate, and tetra-5ee-butyl silicate.

The blending ratio of lucilicate in the above tetraalkaline is as follows: component (a)
) is 1 to 30 parts by weight, preferably 1 to 20 parts by weight, based on 100 parts by weight of organoalkoxysilane.

If it is less than 1 part by weight, the hardness and water resistance of the resulting coating film will be low, while if it exceeds 30 parts by weight, cracks will easily occur in the resulting coating film.

The silyl group-containing vinyl resin [component (C)] used in the composition of the present invention has at least one silyl group having a silicon atom condensed with a hydrolyzable group at the terminal or side chain in one polymer molecule. It is a vinyl resin containing one silyl group. For example, such a silyl group-containing vinyl resin,
■General formula % formula %) (Here, R@ is a halogen atom, an alkoxy group, an acyloxy group, an aminoxy group, or a phenoxy group.

Hydrolyzable groups such as thioalkoxy groups and amino groups, R“
is a hydrogen atom or an organic group having 1 to 8 carbon atoms, k" is a divalent hydrocarbon group, k" is a hydrogen atom or a monovalent hydrocarbon group, n
= an integer from 1 to 3) and an acryloxy-functional silane represented by the formula % (where R'° is a hydrogen atom or a substituted or unsubstituted aliphatic hydrocarbon residue and Represents a group selected from the group consisting of substituted zero-valent aliphatic hydrocarbon residues having at least one ether bond, RI' is a hydrogen atom or a lower alkyl group, and is an integer from n-1 to n-4. ) or by copolymerization of radically polymerizable acrylate monomers shown in
or ■-General formula % (Here, R1″ is a halogen atom, a hydrolyzable group such as an alkoxy group, an acyloxy group, an aminoxy group, a phenoxy group, a thioalkoxy group, an amino group, and R”° is a hydrogen atom or A hydrosilane compound represented by an organic group having 1 to 8 carbon atoms, n = an integer of 1 to 3) can be produced by reacting it with a vinyl polymer having a carbon-carbon double bond, and its production There are no particular limitations on the method.

Here, examples of the acryloxy-functional silane represented by the general formula (A) include γ-ethacryloxypropyltrimethoxysilane, γ-acryloxypropyltrimethoxysilane, γ-ethacryloxypropyltriethoxysilane, and Examples include γ-ethacryloxyprobyl triisobroboxysilane.

One or more types selected from the group consisting of these are used.

Examples of the radically polymerizable monomer represented by the general formula (b) include acrylic acid, methacrylic acid, methyl acrylate, ethyl acrylate, t-glyclate acrylate, 2-hydroxyethyl acrylate, and 2-hydroxyethyl acrylate. -Hydroxypropyl, ethane IJ 7L/methyl acid, ethyl methacrylate, n-butyl methacrylate, savetyl methacrylate, isobutyl methacrylate, glycidium methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, methacrylic acid Monoacrylate monomers such as dimethylaminoethyl, methoxydiethylene glycol acrylate, methoxydiethylene glycol methacrylate, methoxytetraethylene methacrylate and allyl methacrylate; ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, 1,3-butylene dalycol diacrylate and 1,3-butylene Diacrylate monomers such as glycol dimethacrylate;) triacrylate monomers such as limethylolpropane trimethacrylate, trimethylolethane trimethacrylate and tetramethylolmethane triacrylate; tetraacrylate monomers such as tetramethylolmethanetetraacrylate; and the like.

One or more selected from the group consisting of these are used.

A hydrolyzable silyl group-containing acrylic resin is obtained by mixing at least one of these acryloxy-functional silanes and at least one radically polymerizable monomer in a suitable solvent and copolymerizing the mixture using a radical polymerization initiator. be able to.

Examples of the radical polymerization initiator include benzoyl peroxide, dichloropenzoyl peroxide, di-t-
Perester compounds such as butyl peroxide, 2゜5-di(peroxybenzoate)hexyne-3,1,3-bis(t-butylperoxyisopropyl)benzene, t-butyl perbenzoate; azobisisobutyronitrile and methyl Examples include azo compounds such as azobutyrate; and organic peroxides.

As a hydrosilane compound represented by the general formula (/→),
For example, halogenated silane compounds such as methyldichlorosilane, ethyldichlorosilane, phenyldichlorosilane and trichlorosilane; methyldimethoxysilane, methyljethoxysilane, ethyldimethoxysilane, ethyldimethoxysilane, phenyldimethoxysilane, trichlorosilane; Alkoxysilane compounds such as methoxysilane and triethoxysilane; 7-siloxysilane compounds such as methyldiacetoxysilane, phenyldiacetoxysilane, and triacetoxysilane; 7-minosilane compounds such as methyldiaminoxysilane, doriaminoxysilane, and doryaminosilane can be mentioned. One or more selected from the group consisting of these are used.

Vinyl polymers having a carbon-carbon double bond are selected from acrylates represented by the general formula (b) that do not have a hydroxyl group, as well as styrene, α-methylstyrene, vinyl chloride, vinyl acetate, etc. Carbon obtained by copolymerizing one or more vinyl compounds with a conjugated diene compound such as butadiene, isoprene, chlorobrene, etc., and/or an acrylic acid derivative having a carbon-carbon double bond that does not participate in polymerization. - Vinyl polymers having carbon double bonds are preferred.

At least one of these hydrosilane compounds is carbon-
A hydrolyzable silyl group-containing vinyl resin (component (C)) can be obtained by adding it to a vinyl polymer having carbon double bonds.

Specific examples of the hydrolyzable silyl group-containing vinyl resin used in the present invention include Zemlac manufactured by Kanebuchi Chemical Industry ■;
Cylyl; manufactured by Toshiba Silicone ■, silicone acrylic varnish, etc.

The blending ratio of the above-mentioned silyl group-containing vinyl resin (component (C)) is as follows:
10 to 150 parts by weight, preferably 1 part by weight
The amount is 5 to 100 parts by weight.

If the silyl group-containing vinyl resin is less than 10 parts by weight,
The resulting coating film does not have sufficient chemical resistance, and cracks are likely to occur if the coating film is thick. On the other hand, if it exceeds 150 parts by weight, scratch resistance and heat resistance will be poor, and storage stability will also be lacking.

The general formula % formula % aluminum compound used in the composition of the present invention, the hydrolyzate of the aluminum compound (component (d)) is the organoalkoxysilane (
Component (a)), silyl group-containing vinyl resin (component (a)), silyl group-containing vinyl resin (component (a)
Acts as a reaction accelerator during the hydrolysis reaction of C)). Furthermore, it acts to form a crosslinking site between the organoalkoxysilane and the silyl group-containing vinyl group. Therefore, the A/minium compound may be blended during the hydrolysis reaction when mixing both of the above components, but from the viewpoint of storage stability, the above two components may be mixed in advance and blended separately before coating. Also good.

In the above formula, RS and R4 are alkyl groups, k" is a furkyl group or an alkoxy group, and n is an integer of O to 3. Examples of such a/minium compounds include tri-n-propoxyaluminum, tri-n-propoxyaluminum , tri-5ee-butoxyaluminum, tri-n
-butoxyaluminum, 5ee-butoxyaluminum isopropylate, tri-tert-butoxyaluminum, ethyl 7cetoacetate aluminum diisobrobylate, aluminum tris (ethyl acetoacetonate), aluminum tris (acetyl 7cetonate), aluminum monoacetylacetonate Examples include bis(ethyl acetonate) and a partial hydrolyzate of the aluminum compound. These aluminum compounds and partial hydrolysates of the aluminum compounds can be used alone or in combination of two or more.

Note that the above-mentioned partial hydrolyzate of the aluminum compound can be obtained by adding water to a hydrophilic organic solvent containing the Ay minilam compound in an amount that does not cause precipitation or gel.

The blending ratio of the aluminum compound and the partial hydrolyzate of the aluminum compound is 0.01 to 30 parts by weight based on 100 parts by weight of component (a) as organoalkoxysilane.
Parts by weight, preferably 0.1 to 20 parts by weight. 0.0
If it is less than 1 part by weight, the hardness and chemical resistance of the resulting corrugated film will be low, while if it exceeds 30 parts by weight, the storage stability of the composition will deteriorate over time. Moreover, cracks are likely to occur in the resulting corrugated film.

An oligomer of a dimeric reactive siloxane having a functional group at one end of pentamethyldisiloxane and/or an oligomer of a dimeric reactive siloxane having a functional group at both ends of tetramethyldisiloxane used in the composition of the present invention [Component (e)] is glycidyl group-functionalized 1-(
3-glycidoxyprobyl)-1,1,3,3,3-pentamethyldisiloxane, 1,3-bis(3-glycidoxyprobyl)-1,1,3,3-tetramethyldisiloxane Siloxane; amino group-functionalized 1-(3-7 minopropylene!L/
)-1,1,3,3゜3-pentamethyldisiloxane,
1,3-bis(3-aminopropyl)-1,1,3,3
-tetramethyldisiloxane; 1-(3-
hydroxypropyl)-1,1,3,3゜3-pentamethyldisiloxane; 1-mercaptomethyl-1,1,3゜3.3-pentamethyldisiloxane with mercaptan group function, 1-(3-mercaptopropyl) )-1,1
, 3,3,3-pentamethyldisiloxane, 1,3-bis(mercaptomethyl)-1,1,3,3-tetramethyldisiloxane, 1,3-bis(3-mercaptopropyl)-1,1 ,3,3-tetramethyldisiloxone; 1-chloromethyl-1,1,3,3,3- with chloro group function
Pentamethyldisiloxane, 1-(3-chloropropyl)-1゜1.3,3.3-pentamethyldisiloxane,
1.3-bis(chloromethyl)-1+”+3+3-tetramethyldisiloxane, 1.3-bis(3-chloropropyl)-1,1,3,3-tetramethylsiloxane; 3-methacroxypropyl)-
1,1,3°3.3-pentamethyldisiloxane, 1.
3-bis(3-methacryloxypropyl)-1,1゜3
．． Examples include oligomers such as 3-tetramethyldisiloxane, α,ω-bis(viny/L/)polydimethylsiloxane oligomers, and α,ω-bis(hydrodiene)polydimethylsiloxane oligomers.

The oligomer of the dimeric reactive siloxane having a functional group at one end of the pentamethyldisiloxane and/or the oligomer of the dimeric reactive siloxane having a functional group at both ends of the tetramethyldisiloxane are each of the above-mentioned components. It has the effect of binding promoter and buffering agent. The mixing ratio thereof is 0.1 to 10 parts by weight, preferably 1 to 5 parts by weight, based on 100 parts by weight of component (a) in terms of organoalkoxysilane.

If it is less than 0.1 parts by weight, the resulting coating film will have poor crack resistance, while if it exceeds 10 parts by weight, the hardness of the coating film will tend to decrease. The properties of the resulting coating film can be adjusted by adjusting the balance between the aluminum compound and the partial hydrolyzate of the aluminum compound.

The composition of the present invention may further contain various additives, pigments, and fillers as coating film-forming components that are applied by ordinary coating methods as necessary.

In addition, alcohol solvents, aromatic solvents, ketone solvents, ester solvents, polyhydric alcohol solvents, and the like can be contained singly or in combination as diluents for preparing and stabilizing compositions and adjusting concentrations in coating operations.

When preparing the composition of the present invention, (1) to (el
The components may be mixed at once, (at to (cl) components may be mixed together and then mixed with components (d) to (e), or the remainder may be mixed after partially mixing each component. However, the preparation method thereof is not particularly limited.

The coating composition of the present invention is applied onto various substrates by methods such as air spray, airless spray, flow coater, roll, etc., and is cured to form a desired coating film.

Target base materials include metals, ceramics, glass, cement, ceramic moldings, plastics, wood, paper, and fibers.

The coating film can be cured under relatively mild conditions at approximately 80 to 200°C for 5 to 60 minutes, and a relatively thick coating film can be formed without cracking or peeling during curing. It is possible.

[Effect]

The composition of the present invention comprises an organoalkoxysilane (component (
a)) and a polysiloxane derived from a tetraalkyl silicate (component (b)) and a silyl group-containing vinyl resin (component (C)) are combined with an aluminum compound (component (d)) and
Since it has a form that chemically bonds strongly with the reactive siloxane oligomer (component (C)) on the substrate during coating and curing, it does not impair adhesion to the substrate. Therefore, this coating film has properties that are significantly superior to those formed from a chemical copolymer of polysiloxane and a silyl group-containing vinyl resin.

As described above, by using the coating composition of the present invention, a coating film having gloss, high hardness, and excellent stain resistance, weather resistance, solvent resistance, chemical resistance, water resistance, etc. can be formed.

〔Example〕

The present invention will be explained below using examples. In the examples, all parts indicate parts by weight, and all percentages indicate weight %.

Example 1 (i) Preparation of coating composition A Pre-prepared methylmethoxysilane condensate 10
0 parts, 5 parts of tetramethyl silicate, silyl group-containing vinyl resin (Kanekazemurabuku, manufactured by Kanekazem Lab: Trialkoxysilyl group-containing acrylic polymer, solid content 50%)
After preparing 50 parts for mixing, 2 parts of aluminum tris(acetylacetate) and 5 parts of reactive siloxane oligomer were added and mixed homogeneously again to obtain coating composition A.

(b) Evaluation of coating composition Coating composition A obtained in section (8) is air-sprayed onto a cold rolled stainless steel plate (JIS G 4305 5US-CP) so that the dry coating film becomes 20 microns.

This was heated at 180° C. for 30 minutes, and the resulting cured coating film was evaluated on the following items.

The composition of the paint and the obtained results are shown in Tables 1 and 2, respectively, along with the evaluation results of the paint compositions obtained in Examples 2 to 3 and Comparative Examples 1 to 8, which will be described later.

[Coating film appearance] Evaluate the surface condition by visual observation.

[Field of roughness] Evaluated according to the roughness of JIS K 5400.

[Pencil hardness] Evaluation is based on JISK5400 pencil hardness.

[Gloss] Evaluated by JISK5400 60 degree specular reflectance.

[Stain resistance] Apply marker ink (black, blue, red) to the painted surface and observe the degree of removal by washing with methanol after 8 hours.

[Solvent resistance] Soak gauze in methanol and perform a continuous rubbing test on the painted surface 30 times, then observe the condition.

[Boiling water resistance] Observe the condition after immersing in boiling water at 98°C or higher for 8 hours.

[Acid resistance] Drop 1 d of 5% sulfuric acid aqueous solution onto the coated surface, leave it for 24 hours in a petri dish with a lid, wash with water, and observe the condition.

[Drop 1 d of alkali-resistant 35% aqueous sodium hydroxide solution onto the coated surface, let stand for 24 hours in a petri dish with a lid, wash with water, and observe the condition.

[Weather resistance] A 1000 hour irradiation test was carried out using a weatherometer according to JIS K5400, and the condition was observed.

Examples 2 to 3 Using the coating compositions shown in Table 1, the same procedure as in Example 1 was carried out to obtain coating compositions B-C. The composition and evaluation results of the obtained coating composition are shown in Tables 1 and 2, respectively.

Comparative Examples 1 to 8 The coating compositions shown in Table 1 were operated according to Example 1 to obtain coating compositions D-K. The composition and evaluation results of the obtained coating composition are shown in Tables 1 and 2, respectively.

〔Effect of the invention〕

According to the present invention, as shown in the above examples, a coating composition is provided that can easily form a coating film with excellent properties on the surface of a base material such as a metal or ceramic molded product. In particular, the coating film obtained using the coating composition of the present invention has high hardness, excellent stain resistance, gloss, and extremely excellent weather resistance, water resistance, chemical resistance, etc. It is. Maintains high gloss even under particularly corrosive conditions or when left outdoors.
It has excellent properties that cannot be obtained with conventional coating compositions, such as no discoloration or deterioration. Therefore, it is extremely useful as a coating for curtain walls that are exposed to sunlight, equipment that is used under conditions that are prone to corrosion, and building materials that require good design. .

Claims (1)

[Claims] 1. (a) General formula RSi(OR^1)_2 (wherein R is an organic group having 1 to 8 carbon atoms, and R^1 is an alkyl group having 1 to 5 carbon atoms) 100 parts by weight in terms of organoalkoxysilane of a partial condensate of organoalkoxysilane represented by, and (b) General formula Si(OR^2)_4 (wherein R^2 is an alkyl group having 1 to 4 carbon atoms) 1 to 30 parts by weight of a tetraalkyl silicate represented by (a) and (c) a silyl group containing at least one silyl group having a silicon atom bonded to a hydrolyzable group at the terminal or side chain in the polymer molecule. A skeleton composition obtained by mixing 10 to 150 parts by weight of a vinyl resin, and (d) General formula Al(OR^3)_n [OR(R^4)=
CHCOR＾5〕＿■＿−＿n(In the formula, R is a carbon number of 1 to
8 organic group, R^3 and R^4 are alkyl groups, R^5
is an alkyl group or an alkoxy group, n is an integer of 0 to 3), and at least one member selected from the group of partial hydrolysates of the aluminum compound, and ( e) 0.1 to 1 of a dimeric reactive siloxane oligomer having a functional group at one end of pentamethyldisiloxane and/or a dimeric reactive siloxane oligomer having a functional group at both ends of tetramethyldisiloxane
A coating composition comprising 0 parts by weight as a binding reaction component.