JPS63280777A - Coating composition and production thereof - Google Patents

Abstract

PURPOSE:To obtain the titled composition, having excellent preservation stability, adhesive properties, etc., and capable of thick coating and wet-on-wet coating, by containing a specific zirconium compound, beta-diketones, beta-diketo esters, organosilane and water. CONSTITUTION:The aimed coating composition obtained by adding (B) 0.8-3mol. beta-diketones or beta-diketo esters expressed by formula II (R<1> is 1-5C alkyl; R<2> is 1-5C alkyl or 1-5C alkoxy) to (A) 1mol. zirconium compound expressed by the formula Zr(OH)4 or formula I (R is 2-5C alkyl), then adding 0.8-3mol. water, subsequently adding (C) 3-80mol. organosilane expressed by formula III (R<3> is 1-8C organic group; R<4> is 1-5C alkyl or 1-5C acyl) and further adding water in a molar amount of 1-3 times based on the component (C) thereto.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a coating composition and a method for producing the same.

(Conventional technology) In recent years, it has become possible to thicken the film and recoat it, and it has improved adhesion, water resistance, corrosion resistance, insulation resistance, abrasion resistance, heat resistance, moisture resistance, weather resistance, heat resistance, and organic chemical resistance. There is a need for a coating composition that has excellent acid resistance, alkali resistance, etc., and can form a coating film with high hardness.

As a coating composition that partially satisfies these requirements, an acidic aqueous composition containing colloidal silica in a partial clamp of silanol (Japanese Patent Publication No. 52-39691) has been proposed.
A composition in which a silicon compound having 1 to 4 alkoxy groups is blended with zirconium alkoxide (Japanese Patent Application Laid-Open No. 100943/1983) has been proposed.

[Problem that the invention seeks to solve]

However, the coating composition described in Japanese Patent Publication No. 52-39691 is generally inferior in alkali resistance, storage stability, and adhesion, and pinholes occur in thin films with a thickness of about 20 μm, making it difficult to formulate. It takes a long time to mature before it can be used again, has narrow coating conditions, is difficult to work with, has poor wettability with plastics, and is difficult to recoat. .

Furthermore, the coating composition described in JP-A No. 57-100943 does not achieve a thick film, has poor storage stability, tends to form precipitates, and does not provide a uniform coating composition. The problem is that it is difficult to prepare the product.

The present invention has been made against the background of the above-mentioned conventional technical problems, and the composition has good storage stability, can be made into a thick film and can be coated in multiple layers, and has good adhesion, corrosion resistance, insulation resistance, and resistance. A coating composition that can form a hard coating film with excellent abrasion resistance, heat resistance, moisture resistance, weather resistance, flame resistance, water resistance, organic chemical resistance, acid resistance, etc., and especially alkali resistance. The purpose is to provide a method for producing the same.

Means for Solving Problem C] That is, the present invention provides (a) general formula Z r (OR) a or Zr (OR
) a ・Rot ((In the formula, R represents an alkyl group having 2 to 5 carbon atoms) 1-5 alkyl group, R2 has 1 carbon number
~5 alkyl group or C1-5 alkoxy group) (hereinafter simply referred to as "β-diketones or β-ketoesters") 0.8 ~3 mol, (c) general formula R3S
i (OR')z (wherein R represents an organic group having 1 to 8 carbon atoms, R4 represents an alkyl group having 1 to 5 carbon atoms or an acyl group having 1 to 5 carbon atoms) 3
~80 mol, and (dl water (0,8+x)"" (3
+3X) moles (where X indicates the number of moles of the organosilane (c) used).

First, the composition of the present invention will be explained in detail in terms of its composition.

(a) Zirconium compound general formula Zr(OR)n or Zr(OR)4 ・R
The zirconium compound represented by OH is hydrolyzed by reaction with water to form a partial hydrolyzate, and the hydrolyzate is polycondensed to form a partial clamp. It has the effect of promoting condensation and also has the effect of improving the hardness and alkali resistance of the resulting coating film.

R in such a zirconium compound is an alkyl group having 2 to 5 carbon atoms, specifically an ethyl group, an n-propyl group, an i-
Propyl group, n-butyl group, 5ec-7”thyl M, t-
These include a 7'tyl group, an n-pentyl group, an i-pentyl group, and the like.

Specific examples of these zirconium compounds include zirconium tetraethoxide, zirconium tetra-n-propoxide, zirconium tetra-1-propoxide,
Zirconium tetra-n-butoxide, zirconium tetra-5ec-butoxide, zirconium tetra-t-
butoxide, zirconium tetra-n-bentoxide,
Examples include zirconium tetra-1-bentoxide.

Among these (al components), zirconium tetocy n-butoxide is particularly preferred.

Further, component (a) can be used alone or in combination of two or more.

(blβ-diketones or β-ketoesters β-diketones or β-ketoesters represented by the general formula R' C0CHz C0R2 form a complex with (a) a zirconium compound, and are capable of hydrolysis and polymerization of the zirconium compound. It is thought that it acts to suppress condensation and prevent the formation of precipitates.

In this general formula, R1 is an alkyl group having 1 to 5 carbon atoms, such as a methyl group, ethyl group, n-propyl group, 1-propyl group, n-butyl group, 5ec-butyl group, t-butyl group,
n-pentyl group, etc., and R2 is not only the same alkyl group having 1 to 5 carbon atoms as described above, but also an alkoxy group having 1 to 5 carbon atoms, preferably an alkoxy group having 1 to 4 carbon atoms, such as a methoxy group, an ethoxy group. group, n-propoxy group, i-propoxy group, n-butoxy group, 5ec-butoxy group, -butoxy group, etc.

Specific examples of the β-diketones or β-ketoesters include acetylacetone, methyl acetoacetate, ethyl acetoacetate, n-propyl acetoacetate, 1-propyl acetoacetate, n-butyl acetoacetate, and n-butyl acetoacetate. 5ec-butyl, t-butyl acetoacetate, 2.4-
Hexane-dione, 2.4-heptane-dione, 3.5
Examples include -hebutane-dione, 2,4-octane-dione, 2°4-nonane-dione, and 5-methyl-hexane-dione.

Among these components (b), ethyl acetoacetate and acetylacetone are particularly preferred.

Component (b) can be used alone or in combination of two or more.

The amount of such tb+ component is 0 per mole of component (a).
．． It is used in a proportion of 8 to 3 mol, preferably 1 to 2 mol, particularly preferably 1 to 1.5 mol; if it is less than 0.8 mol, the hydrolysis of component (a) may be too rapid and precipitation may occur. On the other hand, if the amount exceeds 3 moles, the rate of hydrolysis of component (a) becomes slow, resulting in poor film-forming properties and further deterioration in alkali resistance, both of which are unfavorable.

(c) Organosilane Organosilane has the general formula R3S i (OR')
It is represented by s and undergoes hydrolysis and polycondensation in the presence of water to produce organopolysiloxane.

R3 in the organosilane is an organic group having 1 to 8 carbon atoms, such as an alkyl group such as a methyl group, an ethyl group, an n-propyl group, an i-propyl group, and a γ-chloropropyl group, a vinyl group, Examples include 3.3.3-trifluoropropyl group, γ-glycidoxypropyl group, T-methacryloxypropyl TE, r-mercaptopropyl group, phenyl group, and 3.4-epoxycyclohexylethyl group.

In addition, R4 in the organosilane is not only an alkyl group having 1 to 5 carbon atoms as described above, but also an acyl group having 1 to 5 carbon atoms,
Preferred are acyl groups having 1 to 4 carbon atoms, such as methyl, ethyl, n-propyl, i-propyl, n
-butyl group, 5ec-butyl group, t-butyl group, acetyl group, etc.

Specific examples of these organosilanes include methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, and i-propyltrimethoxysilane. , i-propyltriethoxysilane, T-chloropropyltrimethoxysilane, T-chloropropyltriethoxysilane, aryltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 3,3.3-trifluoropropyltrimethoxy Silane, 3,3゜3-trifluoropropyltriethoxysilane, T-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, T-methacryloxypropyltrimethoxysilane, T-methacryloxypropyl Triethoxysilane, T-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxydisilane, 3,4-epoxycyclohexylethyltrimethoxysilane, 3,4-epoxycyclohexylethyltriethoxy Examples include silane, preferably methyltrimethoxysilane, methyltriethoxysilane, and phenyltrimethoxysilane.

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

(cI acid component, 3 to 80% per mole of component (a) above
mol, preferably 5 to 50 mol, particularly preferably 10 to 50 mol
It is used in a proportion of 40 mol, and if it is less than 3 mol, it may form a gel and the cured coating film will be prone to cracking, while if it exceeds 80 mol, the alkali resistance of the resulting cured coating will decrease, so it is preferable. do not have.

(d+Water) Water is for causing hydrolysis and polycondensation of component (a) to increase the molecular weight.

As such water, general tap water, distilled water, ion exchange water, etc. can be used. In particular, when the composition is to be highly purified, distilled water or ion-exchanged water is preferable, and ion-exchanged water with an electrical conductivity of 2 μS/cm or less is particularly preferable.

In addition, water is mixed with a hydrophilic organic solvent to prevent rapid hydrolysis and polycondensation of the (al) component, and mixed into a mixed solution of the (a) component and (bl component) as a solution containing 30% by weight or less of water. It is preferable to do so.

The amount of component (d) used is (c) per mole of component (a).
When the usage amount of one component is X moles, (0,8+x) ~
(3+3x) moles, preferably (1+1.2x) to (2
+2x) mole, and if it is less than (0,8+x) mole, hydrolysis and polycondensation will be insufficient, and the alkali resistance of the coating film obtained will decrease;
If the amount exceeds +3 x) moles, the reaction may proceed rapidly and gelation may occur, which is not preferable.

When water is added, the temperature of the reaction mixture increases due to the heat of reaction.
This promotes the hydrolysis and polycondensation of component 10). Usually, natural heat generation and heat radiation occur due to this reaction at room temperature, but in order to promote polycondensation and further increase the molecular weight, the reaction system may be heated to 50 to 80°C. Further, in order to suppress hydrolysis and polycondensation, the reaction system may be cooled to about 30 to 50°C, or a hydrophilic organic solvent may be further added to the reaction system.

Moreover, as the hydrophilic organic solvent (e) used as necessary, alcohols or low-boiling hydrophilic organic solvents having a boiling point of 120° C. or lower are suitable.

Examples of such alcohols include monohydric alcohols and alcohol derivatives.

Examples of these alcohols include methanol, ethanol, n-propyl alcohol, i-propyl alcohol, n-butyl alcohol, i-butyl alcohol, 5eC-butyl alcohol, t-butyl alcohol,
Examples include n-pentyl alcohol, ethylene glycol monobutyl ether, and acetic acid ethylene glycol monoethyl ether.

Examples of the low-boiling hydrophilic organic solvent having a boiling point of 120° C. or lower include acetone, methyl ethyl ketone, and tetrahydrofuran.

Among these hydrophilic organic solvents, preferred are 5-propyl alcohol, 5ec-butyl alcohol, n-propyl alcohol, n-butyl alcohol, acetic acid ethylene glycol monoethyl ether, and methyl ethyl ketone, particularly preferred are i-propyl alcohol, Methyl ethyl ketone and acetic acid ethylene glycol monoethyl ether. These hydrophilic organic solvents can be used alone or in combination of two or more.

In the present invention, in order to increase the hardness of the resulting coating composition while maintaining its transparency, (e) a metal oxide colloid dispersed in a hydrophilic organic solvent may be added.

As this component (e), colloidal silica dispersed in a hydrophilic organic solvent is suitable.

Colloidal silica dispersed in this hydrophilic organic solvent is
It is used not only to increase the hardness of the resulting coating film, but also to increase the solids content of the composition obtained by the present invention, and the thickness of the resulting coating film can be controlled by the amount of this component. can.

Colloidal silica using a hydrophilic organic solvent as a dispersion medium is a dispersion of high-purity silicic anhydride dispersed in the hydrophilic organic solvent, and usually has an average particle size of 5 to 30 mμ, preferably 10 to 30 mμ. 20 mμ, solid concentration 10-40% by weight
It is of a certain degree.

As such colloidal silica dispersed in a hydrophilic organic solvent, commercially available products include, for example, methanol silica sol and isopropatol silica sol manufactured by Nigaga Chemical Industry Co., Ltd., and Oscar manufactured by Catalysts and Chemicals Industry Co., Ltd.

The ratio of φ in the composition of component (e) is preferably 5 to 200 parts by weight, particularly preferably 10 to 100 parts by weight in terms of solid content, based on 100 parts by weight of solid content of the composition of the present invention. If it is less than 5 parts by weight, the improvement in hardness is insufficient, while if it exceeds 200 parts by weight, cracks are likely to occur when formed into a coating film.

In the present invention, it is also possible to separately add various acids to the resulting composition in order to accelerate the curing of the coating film after coating.

Such acids include, for example, inorganic acids such as nitric acid, hydrochloric acid, or acetic acid, formic acid, propionic acid, maleic acid, chloroacetic acid, citric acid, benzoic acid, dimethylmalonic acid, glutaric acid, glycolic acid, malonic acid, toluenesulfonic acid. , oxalic acid and other organic acids, with acetic acid being particularly preferred.

Furthermore, the composition of the present invention contains various surfactants, silane coupling agents, alkali metal salts such as naphthenic acid, octylic acid, nitrous acid, sulfurous acid, aluminic acid, carbonic acid, paints, inorganic pigments, organic pigments, etc. It is also possible to add additives.

Note that adding an organic polymer to the composition of the present invention improves weather resistance,
Heat resistance etc. deteriorate, which is not preferable.

The composition of the present invention containing the components (al to Fdl) as described above preferably has (a) (a) general formula Z r (OR) 4 or Zr
(OR) 4 ・ROH (in the formula, R represents an alkyl group having 2 to 5 carbon atoms), (b) general formula R'COCH2COR" (in the formula, R
1 represents an alkyl group having 1 to 5 carbon atoms, RZ represents an alkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 5 carbon atoms)
β-diketones or β-ketoesters [0
, 8 to 3 moles of (b) (d) water 0.8
~3 mol is added, then (c) (c) general formula R' Si
(OR')3 (In the formula, R3 is an organic group having 1 to 8 carbon atoms, and R4 is an alkyl group having 1 to 5 carbon atoms or an acyl group having 1 to 5 carbon atoms.)
~80 mol was added, and (d) water was added to 1
It can be produced by adding ~3 times the mole.

Here, in step (a), the above (a) component and (b) component are mixed to prepare a mixed solution. In this case, after mixing the (al component and (bl component), (If the time from mixing the al component and the component (b) to the addition of the component (d) in the step (b) described below is less than 15 minutes, when water is added, Precipitation may occur.

Next, in step (b), water is added to the liquid mixture obtained in step (a) to perform hydrolysis and polycondensation.

Use it here? The ratio of the d+ component is as described above (a+ component 1
It is used at a ratio of 0.8 to 3 mol, preferably 1 to 2 mol, with less than 0.8 mol resulting in insufficient hydrolysis and polycondensation of component (a), while more than 3 mol The hydrolysis and polycondensation of component (a) proceed too much.

In addition, in step (b), it is preferable to stir at room temperature for 15 minutes or more after adding the component (d).

If this stirring time is less than 15 minutes, a gel may be formed in step (d) described later.

Next, in the step (c), the reaction product in the step (b) is mixed with the (c1 component) and further reacted.
It is preferable to stir for at least 1 minute.

If this stirring time is less than 15 minutes, a gel may be formed in step (d) described later.

Next, in step (d), component (d) is further added to cause hydrolysis and polycondensation of component (a) and component (c), particularly component (c1).

The ratio of component (d) used here is 1 to 3 times the mole of component (c), preferably 1.2 to 2 times the mole, and if it is less than 1 time mole, hydrolysis and polycondensation may occur. If the amount is insufficient, the alkali resistance of the resulting coating film will decrease, while if the amount exceeds 3 times the mole, the reaction will proceed rapidly and gelation may occur.

In addition, in the method for producing the composition of the present invention, the above (e)
When blending the components, they may be simply added to the composition obtained by the present invention, but since this may reduce the alkali resistance, component (e) is added after the step (c), Preferably, the mixture is mixed at room temperature for 15 minutes or more.

The composition obtained by the present invention is used as a coating after adjusting the solid content concentration to about 10 to 40% by weight using the hydrophilic organic solvent as required.

The composition thus prepared can be applied by brush, spray,
Forms a coating film approximately 1 to 15 μm thick in one coat on substrates such as stainless steel, aluminum, cement, glass, plastic, concrete, paper, organic coatings, and inorganic coatings using coating methods such as dipping. It is possible,
Immediately or after natural drying, for example at 80 to 300°C.
It is cured by heating at a moderate temperature for about 10 to 60 minutes. Furthermore, it is also possible to overcoat the coating film.

〔Example〕

EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to Examples, but it is not limited to the following Examples. In the examples, parts and percentages are based on weight unless otherwise specified.

Moreover, various measurement methods in Examples are as follows.

The storage stability of the coating composition was determined by observing the state of the composition after it was left at room temperature for 3 months.

The appearance of the coating film was observed visually and using a stereomicroscope (100x magnification).

The hardness was based on the pencil hardness according to JIS K5400.

Adhesion was determined by a cellophane tape peel test after a 1-tsurukaku base test according to JIS K5400.

Heat resistance was determined by holding the sample at 400°C for 100 hours in an electric furnace, allowing it to cool naturally, and observing the state of the coating film.

For acid resistance ■, drop 1 ml of hydrochloric acid with a concentration of 5% onto the paint film.
After standing in a petri dish with a lid for one day, it was washed with water and the state of the coating film was observed.

For acid resistance (1), sulfuric acid with a concentration of 5% was dropped onto the coating film in an area of 1 m 1, and after being allowed to stand for one day in a petri dish with a lid, the coating was washed with water and the condition of the coating film was observed.

Alkali resistance (2) was determined by dropping 1 mJ of a 1% sodium hydroxide aqueous solution onto the coating film, leaving it in a petri dish with a lid for one day, washing with water, and observing the condition of the coating film.

For alkali resistance (1), 1 ml of an aqueous solution of sodium hydroxide having a concentration of 10% was dropped onto the coating film, and after being allowed to stand for one day in a petri dish with a lid, the coating film was washed with water and the condition of the coating film was observed.

Water resistance was determined by placing tap water in a petri dish with a lid, soaking the coated substrate in the water for 60 days, and then observing the state of the coating film.

To determine the organic chemical resistance, toluene was placed in a Petri dish, and the coated substrate was immersed therein at room temperature f for 60 days, and then the state of the coating film was observed.

Moisture resistance was determined by maintaining the coating at a temperature of 50° C. and a humidity of 95% for 100 consecutive days, then taking it out and observing the state of the coating film.

Weather resistance was determined by conducting an irradiation test for 4,000 hours using a weather meter according to JIS K5400, and observing the state of the coating film.

Examples 1 to 8 and Comparative Examples 1 to 7 In order to examine the effects of the present invention, compositions A to H (Examples 1 to 8) were prepared using the compositions and manufacturing methods shown in Table 1.

In addition, in order to compare the effects of the present invention, compositions I to 0 (
Comparative Examples 1 to 7) were prepared in the same manner as compositions A to H according to the compositions and manufacturing methods shown in Table 1.

The results are also shown in Table 1.

Test Examples 1 to 10 and Comparative Test Examples 1 to 2 Next, the ingredients shown in Table 2 were further added to the composition obtained as described above to prepare a composition.
0x2 aluminum plate (JIS H400
0, A2024), spray the composition on each,
It was dried by heating at 50° C. for 30 minutes. Using the thus obtained test pieces, various tests were conducted and the results are shown in Table 2.

However, in the test example using methanol silica sol, the silica sol was added after step (c) in producing the composition and mixed by stirring at room temperature for 30 minutes.

〔Effect of the invention〕

The coating composition obtained by the present invention has good storage stability, can be formed into a thick film and can be coated in multiple layers,
Adhesion, corrosion resistance, insulation resistance, abrasion resistance, heat resistance, moisture resistance, weather resistance, flame resistance, water resistance, organic chemical resistance, acid resistance, etc. can be significantly improved, especially alkali resistance. A coating composition capable of forming a coating film with extremely high hardness and a method for producing the same can be provided.

Claims (2)

[Claims] (1) (a) General formula Zr(OR)_4 or Zr(OR
)_4・ROH (in the formula, R represents an alkyl group having 2 to 5 carbon atoms) per mol of zirconium compound,
(b) General formula R^1COCH_2COR^2 (wherein, R
^1 is an alkyl group having 1 to 5 carbon atoms, and R^2 is an alkyl group having 1 to 5 carbon atoms.
5 alkyl group or alkoxy group having 1 to 5 carbon atoms) 0.8 to 3 mol of β-diketones or β-ketoesters, (c) General formula R^3Si(OR^4)_3 (In the formula, R^
3 represents an organic group having 1 to 8 carbon atoms, R^4 represents an alkyl group having 1 to 5 carbon atoms or an acyl group having 1 to 5 carbon atoms, and 3 to 80 mol of an organosilane, and (d) Water (0
．． 8+x) to (3+3x) moles (where x is the above (c
) A coating composition characterized by mixing organosilane (indicates the number of moles used). (2) (a) (a) General formula Zr(OR)_4 or Zr
(b) General formula R^1COCH_2COR^2 (in the formula, R
^1 is an alkyl group having 1 to 5 carbon atoms, and R^2 is an alkyl group having 1 to 5 carbon atoms.
5 alkyl group or alkoxy group having 1 to 5 carbon atoms) to which 0.8 to 3 moles of β-diketones or β-ketoesters are added, and (b) (d) 0 of water is added.
．． Add 8 to 3 mol, then (c) (c) general formula R^3
Si(OR^4)_3 (wherein R^3 is an organic group having 1 to 8 carbon atoms, R^4 is an alkyl group having 1 to 5 carbon atoms or an acyl group having 1 to 5 carbon atoms) Add 3 to 80 mol of organosilane, and further add (d) water to the organosilane (c) in an amount of 1
A method for producing a coating composition, which comprises adding up to 3 times the mole amount.