JPH03115479A - Coating composition - Google Patents

Abstract

PURPOSE:To obtain a coating composition capable of forming a film excellent in water resistance, crack resistance, adhesiveness, etc., on a base material by mixing a specified organosilane with a component selected from a specified silylated acrylic resin, an epoxy resin, etc. CONSTITUTION:A coating composition consisting of 10-90wt.% first component comprising an organosilane shown by the general formula R Si(OR<2>)4-m (wherein R<1> is a 1-8C organic group; R<2> is 1-5C alkyl or 1-4C acyl; m is 1 or 2) and/or its hydrolyzate, partial condensate and/or partial co-condensation product; and 90-10wt.% second component comprising at least two resins selected from a silylated acrylic resin having at least one silyl group of formula I (wherein R<3> and R<4> are each a hydrogen atom or a monovalent hydrocarbon group selected from alkyl and aryl; X is a group selected from halogen, alkoxy, and acyloxy and at least one of X is alkoxy; n is an integer of 0 to 2) in the molecule, an acrylic resin other than the above resin, and an epoxy resin having at least two epoxy groups in the molecule.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a coating composition, and more particularly, the present invention relates to a coating composition that has excellent water resistance, chemical resistance, crack resistance, and heat resistance, and has good adhesion to a substrate. The present invention relates to a coating composition for forming an excellent film.

[Prior art]

In order to prevent corrosion of the inner surface of metal water pipes such as ductile cast iron pipes and steel pipes, it is widely practiced to provide them with cement mortar lining.

In this method, a coating film of acrylic resin or vinyl chloride resin is usually applied to prevent the durability of the mortar lining from decreasing due to the elution of alkaline content from the cement mortar. ing.

However, even when such a coating film is applied, there are many defects such as pinholes in the coating film, so if the water flowing through the water pipe is acidic water with a pH of 7 or less, for example. If the water is corrosive or contains free carbonate, the alkaline content of the cement in the mortar lining will be leached out, causing the mortar lining to deteriorate over a long period of time, resulting in the The adhesion of the coating film on the mortar lining decreases, and physical changes such as changes in the direction of water flow, changes in flow velocity, or strength and weakness of the flow velocity can cause the coating film to peel off, which may eventually lead to corrosion of the inner surface of the water pipe. there were.

[Problem to be solved by the invention]

The present invention was made against the above-mentioned technical background, and provides water resistance, chemical resistance, and
A coating composition for forming a film with excellent crack resistance and heat resistance and excellent adhesion to a substrate, especially when applied to the mortar lining on the inner surface of a water pipe. The purpose of the present invention is to provide a coating composition that can impart water resistance, water resistance, and durability, and can effectively prevent corrosion on the inner surface of water pipes over a long period of time.

[Means to solve the problem]

The coating composition according to the present invention contains 10 to 90% by weight of the following first component and 90 to 10% by weight of the following second component.
It is characterized by containing.

First component general formula (r) RZ++ S l (OR2) 4-Ill (in the formula, R
1 represents an organic group having 1 to 8 carbon atoms, and R2 represents an organic group having 1 to 5 carbon atoms.
represents an alkyl group or an acyl group having 1 to 40 carbon atoms, m
is 1 or 2. ) and/or a hydrolyzate, partial condensate and/or partial co-condensate of the organosilane.

Second component: At least two types selected from the following (A>component, (B) component, and (C) component.

(A) Component (II) (Xs-->(R3>, Si CH-2 (wherein, R3 and R4 are each a hydrogen atom or a monovalent carbonized group selected from an alkyl group, an aryl group, and an aralkyl group) represents a hydrogen group; A silyl group-containing acrylic resin having at least one silyl group represented by the formula (an integer) in its molecule.

(B) Component: Acrylic resin other than the above component (A).

Component (C): An epoxy resin having at least two epoxy groups in one molecule.

The present invention will be explained in detail below.

The coating composition of the present invention includes the first coating composition described in detail below.
component and a second component.

First component: The first component is an organosilane represented by the general formula (I) (hereinafter referred to as "specific organosilane"), a hydrolyzate obtained by hydrolyzing the specific organosilane, and partially It consists of a partial condensate or a partial co-condensate obtained by condensation, or a mixture of two or more selected from all of these.

In the general formula (I) representing a specific organosilane, R1 is an organic group having 1 to 8 carbon atoms, such as an alkyl group such as a methyl group, an ethyl group, or a propyl group, a γ-taloloprobyl group, or a vinyl L3. .3-trifluoropropyl group, T-glycidoxypropyl group, γ-methacryloxypropyl group, γ-mercaptopropyl group, phenyl group, 3,4-epoxycyclohexylethyl group, etc.

Moreover, R2 is an alkyl group having 1 to 5 carbon atoms or a carbon number 1
-4 acyl group, such as methyl group, ethyl group, propyl group, butyl group, acetyl group, propionyl group, etc.

In the general formula (I), m is an integer of 1 or 2.

Specific examples of specific organosilanes include methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, propyltrimethoxysilane, propyltriethoxysilane, and γ-
Chloropropyltrimethoxysilane, γ-chloropropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 3,3.3-trifluoropropyltrimethoxysilane, 3.3.3-)lifluoropropyltriethoxysilane , T-glycidoxypropyltriethoxysilane, T-glycidoxypropyltrimethoxysilane, r-methacryloxypropyltrimethoxysilane, T-methacryloxypropyltriethoxysilane, T-mercaptopropyltrimethoxysilane,
T-mercaptopropyltriethoxysilane, phenyltrimethoxysilane, phenyltrinidoxinlan, 3
．． 4-Epoxycyclohexylethyltriethoxysilane, 3.4-epoxycyclohexylethyltriethoxysilane, dimethyldimethoxysilane, dimethyljethoxysilane, diethyldimethoxysilane, diethyljethoxysilane, diphenyldimethoxysilane, diphenyljethoxysilane, methyltriacetoxy Examples include silane and ethyltriacetoxysilane.

Among the above specific organosilanes, methyltrimethoxysilane or methyltriethoxysilane is preferred.

When using methyltrimethoxysilane and/or methyltriethoxysilane as the specific organosilane, T-glycidoxypropyltrimethoxysilane, T-glycidoxypropyltriethoxysilane, T-methacryloxy It is preferable to use propyltrimethoxysilane or T-methacryloxypropyltriethoxysilane in combination, and in particular, by using γ-glycidoxypropyltrimethoxysilane or γ-glycidoxypropyltriethoxysilane in combination,
The coating composition finally obtained can have excellent storage stability and film-forming properties.

The above-described specific organosilane liberates alcohol by hydrolyzing in an acidic aqueous medium, and produces the corresponding silanol as a hydrolyzate.

Moreover, by further partially condensing this, a partial condensate or a partial co-condensate having a molecular weight of about 1,000 to 50,000 can be obtained. These partial condensates and/or partial cocondensates can also be used as the first component in the present invention.

By containing this first component, the coating composition of the present invention forms a water-retentive film on the surface of the substrate to which it is applied. When the base is cement mortar, it penetrates into the mortar not only through the surface but also through the voids and forms a water-retentive film, and furthermore, the moisture and alkaline content in the mortar penetrate into the mortar. Condensation of the components progresses, and as a result, the film becomes even stronger and envelops the cement tissue, thereby providing an effect of preventing water-soluble substances from leaching out.

The proportion of this first component in the coating composition is 1
The content is 0 to 90% by weight, preferably 20 to 70% by weight. If this proportion is 10% by weight, it will be difficult for the coating composition to form a water-repellent film,
On the other hand, if this proportion exceeds 90% by weight, the film will be brittle even if its water repellency is sufficient, and as a result, the film will become brittle if, for example, corrosive water containing free carbonate comes into contact with it for a long time. Cracks will occur and sealing performance will be lost.

Second component: This second component consists of the following (Δ) component, (B) component and (
It is a component consisting of at least two types selected from component C).

(A>Component: This (A>Component) is made of a silyl group-containing acrylic resin having at least one silyl group represented by the general formula (I[) in the molecule.

In general formula (II), examples of the alkyl group of R3 and R4 include methyl group, ethyl group, propyl group, hexyl group, nonyl group, etc., and examples of the aryl group include phenyl group, xylyl group, tolyl group, naphthyl group, etc. Examples of the aralkyl group include benzyl group, phenethyl group, cumyl group, etc., examples of the halogen atom of X include chlorine atom, fluorine atom, iodine atom, bromine atom, etc., and examples of the alkoxy group include methoxy group, Examples of the acyloxy group include an acetyl group, a propionyl group, and the like; and examples of the thioalkoxy group include a methylmercapto group and an ethylmercapto group.

Such a silyl group-containing acrylic resin can be produced, for example, as follows. Namely, methyl acrylate, ethyl acrylate, butyl acrylate,
In the polymerization of (meth)acrylic monomers such as methyl methacrylate, ethyl methacrylate, butyl methacrylate, and 2-ethylhexyl acrylate, (meth)
An acrylic copolymer with carbon-carbon double bonds is obtained by radical copolymerization of allyl acrylate, etc., and a metal complex catalyst such as platinum is added to the carbon-carbon double bonds of this acrylic copolymer. A hydrosilane compound is reacted with a hydrosilane compound to cause hydrosilylation, thereby obtaining a target silyl group-containing acrylic resin having a molecular weight of i,ooo to 100,000, for example.

In the above, examples of the hydrosilane compound include methyldichlorohydrosilane, trichlorohydrosilane,
Halogenated hydrosilanes such as phenyldichlorohydrosilane; Alkoxyhydrosilanes such as methyljethoxyhydrosilane, methyldimethoxyhydrosilane, phenyldimethoxyhydrosilane, trimethoxyhydrosilane, triethoxyhydrosilane ■Methyldiacetoxyhydrosilane, phenyldiacetoxyhydrosilane,
Acyloxyhydrosilanes such as triacetoxyhydrosilane; methyldiaminoxyhydrosilane, triaminoxyhydrosilane, dimethylaminoxyhydrosilane,
Mention may be made of aminohydrosilanes such as triaminohydronerane.

Of course, this component (A) does not need to be produced by the above-mentioned method, and the production method is not particularly limited as long as it is the above-mentioned silyl group-containing acrylic resin.

Component (B): Component (B) consists of an acrylic resin other than the silyl-based acrylic resin of component (A).

Specific examples of the acrylic resin used as component (B) include methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, iminol acrylate, glycidyl acrylate, methyl methacrylate, ethyl methacrylate,
Examples include (co)polymers of (meth)acrylic monomers such as butyl methacrylate, 2-ethylhexyl methacrylate, iminol methacrylate, and glycidyl methacrylate alone or in combination of two or more types. This acrylic resin has a molecular weight of 10.000 to 200.
A value within the range of 000 is preferable.

Component (C): This component (C) consists of an epoxy resin having two or more epoxy groups in one molecule.

Such epoxy resins can be classified as follows.

■Bisphenol A-epichlorohydrin type Evoquin resin ■Novolac type Evoquin resin ■Heterocyclic epoxy resin 1) Hydantoin epoxy resin 11) Triglycidyl isocyanate epoxy resin P12-cy member-t, l-+2 These epoxy resins has a molecular weight of 100 to 10,
A value in the range of 000 is preferred.

At least two of the above components (A), (B), and (C) are used to form the second component. When using two or more of these components (A), (B) and (C), each component is usually used in an amount of 10% by weight or more of the second component. Thereby, the alkali sealing properties, resistance to free carbonated water, etc. of the composition of the present invention can be improved.

In particular, when a combination of components (A) and (B) or a combination of components (Δ) and (C) is used as the second component, appropriate flexibility can be imparted to the cured product of the composition of the present invention. can be granted.

The proportion of this second component in the coating composition is
The content is 10 to 90% by weight, preferably 30 to 70% by weight. If this proportion is less than 10% by weight, the film formed will be brittle and the film will crack if exposed to corrosive water containing free carbonate for a long period of time. It becomes difficult to obtain sex. On the other hand, if this proportion exceeds 90% by weight, the film will whiten and be likely to peel off if it is in contact with acidic water or corrosive water containing free carbonate for a long period of time.

The coating composition of the present invention contains the above-mentioned first component and second component as essential components, and usually also contains the following components.

Component (a): Water The water used as component (a) is used for curing the first component. The type of water may be arbitrary, and general tap water, distilled water, or ion-exchanged water can be used, and water contained in additive components such as metal oxide sol, which will be described later, can also be used.

The proportion of component (a) is 0 to 100 parts by weight, preferably 5 to 50 parts by weight, per 100 parts by weight of the first component. If this proportion exceeds 100 parts by weight, the resulting coating composition will have low stability.

Component (b): Acid This component (b) acid has the effect of accelerating the hydrolysis of organosilane in the resulting coating composition.

Specific examples of acids as component (b) include inorganic acids such as nitric acid and hydrochloric acid, as well as acetic acid, citric acid, benzoic acid, dimethylmalonic acid, glutaric acid, glycolic acid, malonic acid, toluenesulfonic acid, and sinuic acid. Organic acids such as Among these, nitric acid, hydrochloric acid or acetic acid are preferred.

The ratio of this component (b) is preferably 0.05 to 10 parts by weight based on 100 parts by weight of the first component, thereby controlling the pH of the coating composition to a range suitable for curing of 3.5 to 5.5. It is possible to adjust to.

The coating composition of the present invention usually further contains the following components.

Component (c): Organic solvent The organic solvent that is component (C) is the first component and the second component.
A solvent for diluting ingredients. This solvent is particularly effective for improving the permeability of the resulting coating composition into mortar, and also has the effect of regulating the curing reaction of the composition.

Component (c) includes aromatic solvents, esters,
Various solvents such as alcohols and ethers can be used, and aromatic solvents such as benzene, toluene,
Xylene, etc.; Matachalco-4L Examples, TLF methyl alcohol, ethyl alcohol, isobrobyl alcohol, n-butyl alcohol, ethylene glycol Luna (!
l' I like it L.

The proportion of this component (C) is usually 100 to 1.500 parts by weight per 100 parts by weight of the mixture of the first component and the second component.
Preferably it is 200 to 1.000 parts by weight.

The solid content concentration of the coating composition of the present invention is preferably 5 to 40% by weight, particularly 8 to 30% by weight. If the composition has a solid content of 5% by weight, the thickness of the coating film formed will be too small, resulting in poor sealing properties, and the drying time will be long due to the large amount of solvent. On the other hand, 70% by weight
When the coating composition exceeds
It tends to gel and has a high viscosity, and the formed coating film tends to have low adhesion to the substrate.

Component (d): Curing agent The curing agent, which is component (d), cures component (A) of the first and second components.

By blending this component (d), the coating film to be formed is cured, the coating film strength is increased, and strong sealing properties can be obtained.

Specific examples of component (d) include tin carboxylates such as tin octylate, organic tin carboxylates such as dibutyltin dilaurate, dioctyltin dilaurate, and dibutyltin dilaurate, organic tin oxides such as di-n-butyltin oxide, Organic titanate esters such as tetrabutyl titanate, metal alkoxides such as tetrabutoxyzirconium and their partial hydrolysates, partial chelates of metal alkoxides and their partial hydrolysates, amines, amine salts, quaternary ammonium salts, guanidine Examples include compounds. Among these, preferred are organic tin carboxylates, organic titanate esters, partial chelates and partial hydrolysates of metal alkoxides, and amines.

When a metal alkoxide or the like is used as component (d), it is preferable to adjust the hydrolysis rate of the metal alkoxide by adding ethyl acetoacetate or the like.

The proportion of this component (d) is 0.01 to 10 parts by weight, preferably 0.01 to 5 parts by weight, more preferably 0.05 to 2 parts by weight, based on 100 parts by weight of the mixture of the first component and the second component.
Parts by weight. If this proportion is less than 0.01 parts by weight, the degree of curing of the resulting coating composition will be low and the strength of the coating will be low, making it difficult to obtain a sufficiently high sealing property. If it exceeds 10 parts by weight, curing progresses too quickly, resulting in a pot life that is too short and difficult to handle.

In addition to the above-mentioned components, the coating composition of the present invention further includes a water-dispersed metal oxide sol, an alcohol-dispersed metal oxide sol, various surfactants, various pigments, various dyes, various fillers, thickeners, A pigment dispersant and other additive components can also be added and mixed.

In order to prepare the coating composition of the present invention, for example, a specific organosilane as a first component, water as a component (a), and an acid as a component (b) are mixed to form a specific organosilane as a first component. Hydrolysis and partial condensation of the silane is performed prior to mixing the second component. After that, component (C), an organic solvent, is mixed for the purpose of adjusting the viscosity of the resulting composition and for other purposes. This organic solvent may be mixed at the time of mixing the second component.

The above-mentioned specific organosilane as the first component, water as the component (a), and acid as the component (b) are mixed by stirring at usually 40 to 80°C, preferably 50 to 60°C for about 2 to 24 hours. It will be done. If the temperature during this mixing is less than 40°C, the hydrolysis and partial condensation of the organosilane will proceed. If the temperature exceeds 80°C, the hydrolysis and partial condensation of the specific organosilane will become too rapid. There is.

After cooling these mixtures to room temperature, the second component or the second component and the organic solvent of component (c) are added, usually 1 to 1
Mix for 2 hours. The coating composition of the present invention is then prepared by adding a curing agent as needed.

The coating composition of the present invention can be applied to cement, mortar and other inorganic ceramic substrates, stainless steel, aluminum, and other metals by application means such as brushing, spraying, rolling, dipping, and curtain roll.
It can also be applied to the surface of a substrate made of glass, plastic, etc., for example, on mortar, by coating it in an amount of 20 to 300 g/m 2 and drying it at room temperature to 300°C. In this drying, the curing of the component (A) blended as the first component and the second component is promoted, and a film having the desired good properties can be formed.

〔Example〕

Examples of the present invention will be described below, but the present invention is not limited thereto.

Note that in the following, "parts" indicate "parts by weight."

Example 1 100 parts of methyltriethoxysilane, 201 parts of water, and 0.2 parts of 0.1N hydrochloric acid were charged into a reactor equipped with a reflux condenser and a stirrer (first charge), and the mixture was heated at 60 tons. 6
After stirring for an hour, the mixture was cooled to room temperature. After that, silyl group-containing acrylic resin "Zemlac AP3701J (manufactured by Kanebuchi Chemical Co., Ltd., non-volatile content 60% by weight, Tg 52°C) 2
0 parts and acrylic resin “Dianal LR-162J”
(Mitsubishi Rayon Co., Ltd., non-volatile content: 35% by weight, glass transition point Tg: 52°C) 140 parts and 550 parts of toluene were added in the second step) and stirred for 1 hour to obtain a main ingredient.

To this main ingredient, 40 parts of a mixture of 50 parts of tetrabutoxyzirconium, 10 parts of ethyl acetoacetate, 2 parts of water, and 38 parts of isopropyl alcohol (hereinafter referred to as "curing agent ■") is added (tertiary preparation). , thereby preparing a coating composition.

Example 2 In the second preparation of Example 1, acrylic resin ``Dyanal LR-248J (manufactured by Mitsubishi Rayon Co., Ltd., non-volatile content 40% by weight, Tg 102°C) was used instead of acrylic resin ``Dyanal LR-162J''. A coating composition was prepared in the same manner as in Example 1 except for the following.

Example 3 A coating composition was prepared in the same manner as in Example 1, except that the proportions of each component were changed as shown in Table 1.

Example 4 In the third charging of Example 1, dioctyltin dilaure) rSNTIFJ (
90% of a mixture (hereinafter referred to as "hardening agent ■") of Sankyoki Synthetic Chemical Co., Ltd.) and toluene in a ratio of 1:9 by weight.
A coating composition was prepared in the same manner as in Example 1, except that

Example 5 In the second preparation of Example 1, the epoxy resin "Epicote 1o02J (manufactured by Yuka Shell Epoxy, non-volatile content 100% by weight, epoxy equivalent 630) was used instead of the silyl group-containing acrylic resin "Zemlac AP3701", In addition, acrylic resin “Dianal LR-162”
A coating composition was prepared in the same manner as in Example 1, except that the proportion of J was 110 parts and the proportion of toluene was 570 parts.

Comparative Examples 1 to 3 In each of these, the acrylic resin “Dianal L
R-162J, a silyl group-containing acrylic resin [Zemlac AP3701 J], and an epoxy resin "Epicoat 1001 J" were used alone as coating agents.

Comparative Example 4 In Example 1, toluene 2 was added without performing the secondary charging.
A coating composition was prepared in the same manner as in Example 1, except that only 40 parts of curing agent (1) was used and 20 parts of curing agent (2) was used.

Test Examples Each of the coating compositions obtained in Examples 1 to 5, the coating agents of Comparative Examples 1 to 3, and the coating composition of Comparative Example 4 was heated to 60°C and coated with an inner diameter of 10 cm.
The solution was applied with a brush to the inner surface of a 10 cm long mortar lined pipe for waterworks in an amount of 150 g/m2, and dried at room temperature for 4 days to obtain a sample tube. Then, each of the sample tubes obtained was examined for alkali sealing properties and free carbonated water resistance. The details and evaluation method of each measurement are as follows.

Put test water with a pH of 7.0 obtained from the tap into an alkaline sealing sample tube, seal both ends of the sample tube, let it stand for one day, then measure the pH of the water in the sample tube. It was evaluated according to the criteria of

◎: pH 7.0 to 8.0 ON pH 8.1 to 8.6 Δ: p) (8.7 to 9.0 x: pH 9.1 or higher Free carbonated water resistance Continuously pass free carbonated water into each sample tube. The state of the film was observed after one month had passed since the start of water flow, and the presence or absence of blistering, whitening, and cracking was determined according to the following criteria.

◎: No abnormality at all ○: Abnormality occurs in less than 1% of the seal coat area △: Abnormality occurs in 1 to 20% of the seal coat area ×: Abnormality occurs in 20% or more of the seal coat area The results are shown in Table 1.

As is clear from Table 1, the coating compositions according to Examples 1 to 5 had a lower
All have excellent alkali sealing properties and resistance to free carbonated water.

[Effect of Hathu]

The coating composition of the present invention can eliminate defects such as pinholes on the surface of substrates made of cement, mortar, other inorganic ceramic substrates, metals such as stainless steel and aluminum, and products such as glass and plastic. It is possible to form a film that has excellent water resistance, chemical resistance, crack resistance, and heat resistance, and has excellent adhesion to the substrate without causing any formation of water. In some cases, the mortar lining can be provided with excellent water-holding properties, water resistance, and durability, and corrosion of the inner surface of water pipes can be effectively prevented over a long period of time.

Claims (1)

[Scope of Claims] 1) A coating composition comprising 10 to 90% by weight of the following first component and 90 to 10% by weight of the following second component. First component: General formula (I) R^1_mSi(OR^2)_4_-_m (In the formula, R^1 represents an organic group having 1 to 8 carbon atoms, and R^2
represents an alkyl group having 1 to 5 carbon atoms or an acyl group having 1 to 4 carbon atoms, and m is 1 or 2. ) and/or a hydrolyzate, partial condensate and/or partial co-condensate of the organosilane. Second component: At least two components selected from the following components (A), (B) and (C). (A) Component: General formula (II) ▲ Numerical formulas, chemical formulas, tables, etc. represents a hydrocarbon group, X is a halogen atom, an alkoxy group, an acyloxy group, an aminoxy group, a phenoxy group,
At least one group selected from a thioalkoxy group and an amino group is an alkoxy group, and n is an integer of 0 to 2. ) A silyl group-containing acrylic resin having at least one silyl group represented by the following in its molecule. (B) Component: Acrylic resin other than the above (A) component. Component (C): An epoxy resin having at least two epoxy groups in one molecule.