JPH04202376A - Zro2-cao-based coating composition - Google Patents

Abstract

PURPOSE:To obtain the subject composition storable over a long period as a coating material for metal, plastics, wood, etc., and giving a coating film having excellent stability by compounding a zirconium tetraalkoxide, a calcium compound, a beta-diketone and an organic solvent at specific ratios. CONSTITUTION:The objective composition is produced by compounding (A) a compound of formula Zr(OR<1>)4 (R<1> is 1-5C aliphatic hydrocarbon group), (B) a calcium compound such as calcium chloride and calcium bromide, (C) a beta- diketone (preferably acetylacetone, etc.) and (D) an organic solvent (preferably ethanol, etc.) at molar ratios B/A of 0.01-2.5, C/A of 0.5-6 and D/(A+B) of 0.05-500.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention can be stored for a long time, can be easily coated,
The present invention relates to a ZrO=-CaO coating composition that provides a coating film with excellent stability.

(Conventional technology) Conventionally, coatings have been used to form coatings on materials such as metal, plastic, wood, paper, cement, and graphite in order to improve their corrosion resistance, heat resistance, abrasion resistance, insulation, etc. A typical coating method includes, for example, coating with an organic paint using a silicone resin as a binder. However, the coating film obtained from the above-mentioned organic paint has poor heat resistance, and
It cannot withstand long-term use in an atmosphere of 00°C or higher.

On the other hand, it has been proposed to coat materials with a heat-resistant ceramic thin film, and currently this method is mainly applied to metal materials.

Examples of the above-mentioned coating methods include vapor deposition, sputtering, CVD, thermal spraying, etc. However, each of the above-mentioned coating methods has major restrictions on the material, size, shape, etc., and the coating operation is complicated. It had the disadvantage of being

In order to solve the above-mentioned drawbacks, zircon-based compositions that can be easily coated on materials having various sizes and shapes have been proposed.
This publication describes a composition formed by mixing a zirconium compound represented by the general formula Zr (DCsH, ), ethyl silicate, and isopropyl alcohol, and Frame No. 1e3-19ot75 describes a composition comprising a zirconium compound represented by the general formula Zr (DCsH, ), Compositions consisting of a salt, a silicon alkoxide or a derivative thereof, water and an organic solvent are described. However, the above-mentioned composition had the disadvantage that it had poor long-term storage stability, and the coating film obtained by coating it on the material was prone to cracking and peeling.

(Problems to be Solved by the Invention) The present invention was made in view of the above-mentioned drawbacks, and its purpose is to provide a long-storable ZrO2- An object of the present invention is to provide a Cao-based coating composition.

(Means for Solving the Problems) Zirconium tetraanosicoxide (a) used in the present invention is a compound represented by the general formula Zr (OR')4, where R' is aliphatic carbonization. The number of carbon atoms should be 1 to 5.
limited to.

As the zirconium tetraalkoxide (a),
For example, zirconium tetramethoxide, zirconium tetraethoxide, zirconium tetra-n-propoxide, zirconium tetra-1so-propoxide, zirconium tetra-n-butoxide, zirconium tetra-5ec-butoxide, zirconium tetra-ter
Examples include t-butoxide, and zirconium tetra-n-butoxide and zirconium tetra-ispropoxide are particularly preferred.

These may be used alone or in combination of two or more.

The calcium compound (b) used in the present invention is a compound selected from the group consisting of calcium chloride, calcium bromide, and calcium iodide. Examples include water salt, calcium chloride dihydrate, calcium chloride tetrahydrate, calcium chloride hexahydrate, anhydrous calcium bromide, calcium bromide hexahydrate, anhydrous calcium iodide, calcium iodide anhydrous salt, etc., especially anhydrous Calcium chloride and anhydrous calcium bromide are preferred.These may be used alone or in combination of two or more.

1. Even if the amount of the calcium compound fb) added to the zirconium tetraalkoxide (a) is small,
Even if the amount increases, cracks are likely to occur in the resulting coating film, so the molar ratio of calcium compound (b)/zirconium tetraalkoxide (a) is 0.01 to 2.5, preferably 0.1 to 2. .0.

Examples of the β-diketone (c) used in the present invention include acetylacetone, benzoylacetone, dibenzoylmethane, dipivaloylmethane, 3-methylpentane-2,4-dione, trifluoroacetylacetone, benzoyltrifluoro Examples include acetone, with acetylacetone and benzoylacetone being particularly preferred. These may be used alone or in combination of two or more.

When the amount of β-diketone (c1 added to zirconium tetraalkoxide (a) decreases), ZrO2-
The stability of the CaO-based coating composition decreases, resulting in poor long-term storage stability, and if the amount increases, cracks are likely to occur in the resulting coating film. ) is 0.5 to 6
limited to.

The organic solvent (d) used in the present invention is the zirconium tetraalkoxide (a) and the calcium compound (
It is not particularly limited as long as it is compatible with b), and examples include alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol, and butyl alcohol, ketones such as acetone and methyl ethyl ketone, and tetrahydrofuran. , especially ethanol and isopropyl alcohol. These may be used alone or in combination of two or more.

When the amount of the organic solvent (d) added is small, ZrO2
-The stability of the CaO-based coating composition decreases, resulting in poor long-term storage stability, and when the amount increases, pinholes are likely to occur in the resulting coating film. (b
)] (molar ratio) is 0.05 to 500, preferably 0.2 to 300.

Any method may be adopted as the method for producing the ZrO2-CaO-based coating composition of the present invention, but after mixing the zirconium tetraalkoxide (a), the β-diketone (c) and the organic solvent (d), the calcium Compound(
Preferably, b) is added.

The composition of the ZrOz-CaQ-based coating composition of the present invention is as described above, but in order to further improve the stability (cracking resistance, peeling resistance, etc.) of the resulting coating film, Ca
ZrO3 powder may be added.

As the average particle size of the CaZrO3 powder becomes smaller, Zr
It becomes difficult to disperse into the OzCaO-based coating composition, and if it becomes large, cracks are likely to occur in the resulting coating film, so it is preferably 0.01 to 100 μm, and 0.02 μm.
~10 μm is particularly preferred.

When the amount of the above-mentioned CaZ r○3 powder added to the Zr○z-CaO-based coating composition is small, the degree of improvement in stability of the resulting coating film becomes low;
Since the stability of the 02-CaO-based coating composition decreases and its long-term storage property deteriorates, all ZrO2CaO-based oxides (oxides formed from zirconium tetraalkoxide (a) and calcium compounds (b) and Carr
It is preferably 1 to 60% by weight based on the total amount of ys powder. Incidentally, it is preferable that the CaZrO+ powder is added after mixing the constituent materials of the ZrO2-CaO-based coating composition.

The ZrO2CaO-based coating composition of the present invention is applied or impregnated onto the material and dried to form a ZrOx-
A Ca 2 O-based oxide film is formed.

The above-mentioned coating method is not particularly limited, and examples include coating methods using a brush, spray coating, dip coating, spin cord, roll coating, and the like.

The above-mentioned impregnation method is not particularly limited, and includes, for example, a method of impregnation by dipping under normal pressure, a method of impregnating by dipping under reduced pressure, etc., and impregnation by dipping under reduced pressure is preferred.

The drying method is not particularly limited, and may be air-dried at room temperature or heat-dried. Moreover, after drying, high-temperature heat treatment may be performed as necessary.

(Example) The present invention will be explained in detail below.

The evaluation method for each physical property of the ZrO2CaO-based coating composition shown in the results is as follows.

(1) Initial adhesion In the obtained ZrO2-CaO coating composition,
A slide glass (manufactured by Matsunami Co., Ltd.) that had been ultrasonically cleaned in acetone was immersed, pulled up at a speed of 300 II + m/min, and then dried under the following conditions to form a ZrO2-CaO-based oxide coating layer to form an evaluation sample. Prepared and JIS D 020
A cross-cut tape peeling test was conducted according to 2, and 100
The ratio of peeled squares to the squares of each ZrO2-CaO-based oxide coating layer (peeling rate) was measured and evaluated.

(Drying conditions) Initial drying: 25°C, 24 hours Final drying at 2500°C (temperature raised from 25°C to 50°C/hr)
, 2 hours (2) Pencil hardness Using the obtained ZrOz-CaO-based coating composition, an evaluation sample was prepared in the same manner as in the above evaluation of initial adhesion, and measured according to JIS K 5400.

(3) Boiling water resistance (cracking resistance and adhesion durability) Using the obtained ZrO2CaO-based coating composition,
An evaluation sample prepared in the same manner as in the above evaluation of initial adhesion was immersed in boiling water for 8 hours, and then its surface condition was subjected to a sensory test to evaluate crack resistance according to the following criteria.

(Judgment Criteria) 02 No cracks on the surface evaluated.

(4) Acid resistance (cracking resistance and adhesion durability) Using the obtained ZrO2-CaO-based coating composition, an evaluation sample prepared in the same manner as in the above initial adhesion evaluation was placed in 20 wt% hydrochloric acid. After being immersed in water for 75 hours, the surface condition was subjected to a sensory test and the crack resistance was evaluated according to the following criteria.

(Judgment criteria) 02 No cracks on the surface ×: Cracks on the surface After performing the above sensory test, a cross-cut tape peeling test was performed in the same manner as the above initial adhesion evaluation, and the adhesion durability was evaluated by the peeling rate. evaluated.

(5) Long-term shelf life The sealed container containing the obtained ZrOz-CaO-based coating composition was left in an atmosphere of 50°C and 65% RH for 3 months, and then the initial adhesion was evaluated in the same manner as above. A cross-cut tape peeling test was conducted, and long-term storage stability was evaluated according to the following criteria.

(Judgment criteria) ○: Peeling rate is 20% or less ×: Peeling rate is over 20% Examples 1 to 12 Predetermined amounts of zirconium tetraalkoxide, β-diketone, and isopropyl alcohol shown in Table 1 were placed in a separable flask. for 15 hours at room temperature, stirring speed 8.
A stabilized alcoholic solution of zirconium tetraalkoxide was obtained by stirring at 0.00 rpm.

A predetermined amount of the calcium compound shown in Table 1 was added to the obtained alcohol solution, and the mixture was stirred at room temperature for 24 hours at a stirring speed of 80.
A ZrO2-CaO based coating composition was obtained by stirring at 0 rpm.

Using the obtained ZrO2CaO coating composition, various physical properties were measured based on the measurement method described above, and the results are shown in Table 1.

Example 13.14 As shown in Table 1, ZrO2-CaO was prepared in the same manner as in Example 1 except that the amount of isopropyl alcohol added was changed.
A coating composition was obtained.

The obtained ZrO2-CaO-based coating composition was coated with a first
A predetermined amount of CaZrOs powder (average particle size 1 μm) shown in the table was used.
) and stirred at room temperature for 1 hour at a stirring speed of 11000 rpm to obtain a ZrO, -CaO based coating composition containing CaZrO* powder.

Using the obtained ZrOz-CaO-based coating composition containing CaZrOs powder, various physical properties were measured based on the measurement method described above, and the results are shown in Table 1.

(The following is a blank space) Comparative Examples 1 to 8 As shown in Table 2, ZrOz-CaO-based coating compositions were obtained in the same manner as in Example 1, except that the amounts of the constituent materials in the composition were changed.

Using the obtained ZrO2CaO-based coating composition, various physical properties were measured based on the measurement method described above, and the results are shown in Table 2.

Comparative Example 9 As shown in Table 2, a ZrOz-CaO based coating composition containing CaZ r03 powder was obtained in the same manner as in Example 13 except that the amount of CaZrOs powder added was changed.

The obtained ZrO-CaO containing C a Z r Os powder
Based on the above measurement method using a system coating composition,
Each physical property was measured and the results are shown in Table 2.

(Blank below) (Effects of the Invention) The composition of the ZrOa-CaO-based coating composition of the present invention is as described above, and since it consists of specific amounts of zirconium tetraalkoxide, calcium compound, β-diketone, and organic solvent, A coating film that can be stored for a long period of time and has excellent corrosion resistance, heat resistance, abrasion resistance, insulation, etc. can be easily formed on various materials such as metal, plastic, wood, paper, cement, and graphite.

Claims (1)

[Claims] 1. (a) General formula Zr(OR^1)_4 (wherein R^1
(b) a calcium compound selected from the group consisting of calcium chloride, calcium bromide and calcium iodide (c) β-diketone and (d) a ZrO_2-CaO-based coating composition containing an organic solvent, wherein the molar ratio of each component in the composition is (b)/(a
)=0.01-2.5, (c)/(a)=0.5-6 and (d)/((a)+(b))=0.05-500, ZrO_2-CaO based coating Composition.