JPH04264176A - Zro2-cao-based coating composition - Google Patents

Abstract

PURPOSE:A ZrO2-CaO-based coating composition which can be applied readily, can be stored for a long period of time, and can form a stable coating film by compounding a specified zirconium tetraalkoxide, a specified calcium compound, a specified nitrogen compound and an organic solvent. CONSTITUTION:A coating composition which consists of zirconium tetraalkoxide represented by Zr(OR<1>)4 (wherein R<1> represents 1-5C alkyl); a calcium compound selected from calcium chloride, calcium bromide and calcium iodide; a nitrogen compound selected from an amine compound represented by formula I or II (wherein R<2> represents 1-5C alkyl; R<3> represents 1-5C alkyl or hydrogen; and R<4> represents 2-5C alkylene), an ethylenediamine derivative, a pyridyl alcohol derivative and piperidine; and an organic solvent. The molar ratio of the calcium compound to the zirconium tetraalkoxide, that of the nitrogen compound to the zirconium tetraalkoxide, and that of the organic solvent to the zirconium tetraalkoxide are 0.01 to 2.5, 0.5 to 6, and 0.05 to 500, respectively.

Description

Description: [0001] The present invention relates to a ZrO2-CaO based coating composition. [Prior Art] Conventionally, metals, plastics, wood, paper,
Coatings are used to form coatings on materials such as cement and graphite in order to improve their corrosion resistance, heat resistance, abrasion resistance, insulation, etc.
Examples of the coating method include 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 cannot withstand long-term use in an atmosphere of 200° C. or higher. On the other hand, it has been proposed to coat materials with a heat-resistant ceramic thin film, and this method is currently mainly applied to metal materials. Examples of the coating method include vapor deposition method, sputtering method, CVD method,
Examples include thermal spraying, but each of the above coating methods is
There are major restrictions on the material, size, shape, etc., and the coating operation is complicated. [0004] In order to solve the above-mentioned drawbacks, zircon-based compositions have been proposed that are not limited to materials and can be easily coated on materials having various sizes and shapes. Publication No. 61-250063 states that Z
A composition obtained by mixing a zirconium compound represented by r(OC4H9)4, ethyl silicate, and isopropyl alcohol is described, and JP-A-63-190175 discloses a composition formed by mixing a zirconium compound represented by r(OC4H9)4, ethyl silicate, and isopropyl alcohol. Compositions consisting of its derivatives, water, and organic solvents 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. [0005] The present invention has been made in view of the above-mentioned drawbacks, and its purpose is to provide a coating film that can be easily coated and has excellent stability over a long period of time. The object of the present invention is to provide a ZrO2-CaO coating composition that can be stored. Means for Solving the Problems The zirconium tetraalkoxide (a) used in the present invention has the general formula Zr (
It is a compound represented by OR1)4, in which R1
indicates an alkyl group, but as the number of carbon atoms increases, ZrO2-
The number of carbon atoms is limited to 1 to 5 because the stability of the CaO-based coating composition decreases and its long-term storage stability deteriorates. The above zirconium tetraalkoxide (a
), for example, zirconium tetramethoxide, zirconium tetraethoxide, zirconium tetra-n-propoxide, zirconium tetra-iso-propoxide, zirconium tetra-n-butoxide, zirconium tetra-sec-butoxide, zirconium tetra-tert -butoxide, etc., and zirconium tetra-n-butoxide and zirconium tetra-iso-propoxide are particularly preferred. These may be used alone or in combination of two or more. Calcium compound (b) used in the present invention
) is a compound selected from the group consisting of calcium chloride, calcium bromide and calcium iodide, and examples of the calcium compound (b) include anhydrous calcium chloride, calcium chloride monohydrate, calcium chloride dihydrate, Examples include calcium chloride tetrahydrate, calcium chloride hexahydrate, anhydrous calcium bromide, calcium bromide hexahydrate, anhydrous calcium iodide, calcium iodide hexahydrate, etc., especially anhydrous calcium chloride and anhydrous calcium bromide. preferable. These may be used alone or in combination of two or more. [0009] Even if the amount of the calcium compound (b) added to the zirconium tetraalkoxide (a) is small or large, cracks are likely to occur in the resulting coating film. Alkoxide (a) (molar ratio) is 0.
It is limited to 0.01 to 2.5, preferably 0.1 to 2.0. The nitrogen-containing compound (c) used in the present invention is
It is at least one compound selected from the group consisting of amine compounds, ethylenediamine derivatives, pyridyl alcohol derivatives, and bipyridine. The above amine compound has the following general formula (I)
Or a compound represented by (II). ##STR2## In the formula, R2 and R3 represent an alkyl group, but as the number of carbon atoms increases, the stability of the ZrO2-CaO-based coating composition decreases, resulting in poor long-term storage stability. Therefore, the number of carbon atoms is limited to 1 to 5. However, R3 may be hydrogen. In addition, in the formula, R4 represents an alkylene group, but ZrO
The number of carbon atoms is limited to 2 to 5 because the stability of the 2-CaO-based coating composition decreases and its long-term storage stability deteriorates. Examples of the compound represented by the above formula (I) include N-methylethanolamine, N-ethylethanolamine, N-methylpropanolamine, N-methylethanolamine, and N-methylpropanolamine.
Methylisopropanolamine, N-ethylpropanol
amine, N-ethylisopropanolamine, N,N
-dimethylethanolamine, N,N-diethylethanolamine, N,N-dibutylethanolamine, N,
Examples of the compound represented by formula (II) include N-dimethylpropanolamine, N,N-dimethylisopropanolamine, and N-methyl-N,N-diethanolamine. Ethyl-N,N-diethanolamine, N-methyl-N,N-diisopropanolamine, etc., especially N,N-dimethylethanolamine, N,N-diethylethanolamine, N-methyl-N
, N-diethanolamine and N-ethyl-N,N-
Diethanolamine is preferred. Examples of the ethylenediamine derivatives include ethylenediamine, N,N'-dimethylethylenediamine, N,N'-diethylethylenediamine, and N-
Examples include hydroxyethyl-N'-ethylethylenediamine. As the above pyridyl alcohol derivative,
For example, pyridyl alcohol, 2-pyridyl carbino
alcohol, α-(2-pyridyl)ethyl alcohol, β-(2-pyridyl)ethyl alcohol,
-pyridyl)ethyl alcohol and the like. [0015] Examples of the above bipyridine include 2,2
'-Bipyridine, 2,3'-bipyridine, 2,4'-bipyridine, 3,3'-bipyridine, 3,4'-bipyridine, 4,4'-bipyridine, etc., especially 2,2'
The amount of the nitrogen-containing compound (c), preferably bipyridine, added to the zirconium tetraalkoxide (a) is such that if the amount is too small, the stability of the ZrO2-CaO coating composition will be reduced and the long-term storage stability will be poor; Compound (c) / zirconium tetraalkoxide (a) is likely to cause cracks in the resulting coating film.
(molar ratio) is 0. Limited to 5-6. The organic solvent (d) used in the present invention is:
It is not particularly limited as long as it is compatible with the zirconium tetraalkoxide (a) and calcium compound (b), such as methyl alcohol, ethyl alcohol, isopropyl alcohol, butyl alcohol, etc. alcohols, ketones such as acetone and methyl ethyl ketone, and tetrahydrofuran, with ethanol and isopropyl alcohol being particularly preferred. These may be used alone or in combination of two or more. [0017] If the amount of the organic solvent (d) added is too small, the stability of the ZrO2-CaO coating composition will be reduced, resulting in poor long-term storage stability, and if it is too large, pinholes will form in the resulting coating film. organic solvent (d
)/[zirconium tetraalkoxide (a) + calcium compound (b)] (molar ratio) is 0. 05-50
0, preferably 0. It is 2-300. The method for producing the ZrO2-CaO coating composition of the present invention is not particularly limited, and includes, for example, a method of mixing the above-mentioned constituent materials all at once;
Examples include a method in which specific constituent materials are divided and mixed, and then the remaining constituent materials are added and mixed; however, the latter method is preferred; for example, zirconium tetraalkoxide (a), nitrogen as specific constituent materials, etc. Containing compound (c)
A method is adopted in which the calcium compound (b) is added after mixing the organic solvent and the organic solvent (d). The composition of the ZrO2-CaO coating composition of the present invention is as described above, but in order to further improve the stability (crack resistance, peeling resistance, etc.) of the resulting coating film, CaZrO3 powder is added. may be added. As the average particle size of the above CaZrO3 powder becomes smaller, ZrO
Dispersion into the 2-CaO-based coating composition becomes difficult, and if the size increases, cracks are likely to occur in the resulting coating film. 01 to 100 μm is preferable, and 0.01 to 100 μm is preferable.
Particularly preferred is 02 to 10 μm. [0020] ZrO2-Ca of the above CaZrO3 powder
If the amount added to the ZrO2-CaO-based coating composition is small, the degree of improvement in the stability of the resulting coating film will be low, and if it is too large, the stability of the ZrO2-CaO-based coating composition will be reduced and All ZrO2-C is
aO-based oxide (zirconium tetraalkoxide (a)
and the calcium compound (b) and the total amount of CaZrO3 powder) is preferably 1 to 60% by weight. Note that the addition of CaZrO3 powder
Preferably, this is done after mixing the constituent materials of the rO2-CaO-based coating composition. The ZrO2-CaO based coating composition of the present invention is applied or impregnated onto the above material and dried to form a ZrO2-CaO based oxide film. The above coating method is not particularly limited, and examples include brush coating, spray coating, dip coating, spin coating,
Application methods include 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. Further, after drying, high-temperature heat treatment may be performed as necessary. [Examples] Examples of the present invention will be described below. The evaluation method for each physical property of the ZrO2-CaO coating composition shown in the results is as follows. (1) Initial adhesion In the obtained ZrO2-CaO-based 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 mm/min, and then dried under the following conditions to form a ZrO2-CaO-based oxide coating layer to form an evaluation sample. A cross-cut tape peeling test was conducted in accordance with JIS D 0202, and the ratio of peeled squares to squares of 100 ZrO2-CaO-based oxide coating layers (peeling rate) was measured and evaluated. . (Drying conditions) Initial drying: 25°C, 24 hours Final drying: 500°C (temperature raised from 25°C at 50°C/hr)
, held for 2 hours (2) Pencil hardness Using the obtained ZrO2-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. did. (3) Boiling water resistance (crack resistance and adhesion durability)
Using the obtained ZrO2-CaO-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 the state of the surface was subjected to a sensory test. The crack resistance was evaluated using the following criteria. (Judgment criteria)

○: 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 in the above evaluation of initial adhesion, and the adhesion durability was evaluated based on the peeling rate. (4) Using the obtained ZrO2-CaO coating composition with acid resistance (crack resistance and adhesion durability),
An evaluation sample prepared in the same manner as in the above evaluation of initial adhesion was immersed in 20 wt % hydrochloric acid for 75 hours, and then the surface condition was sensory tested to evaluate crack resistance according to the following criteria. (Judgment criteria)

○: 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 in the above evaluation of initial adhesion, and the adhesion durability was evaluated based on the peeling rate. (5) Long-term storage The sealed container containing the obtained ZrO2-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. Evaluation samples were prepared in the same manner, subjected to a cross-cut tape peeling test, and long-term storage stability was evaluated according to the following criteria. (Judgment criteria) ○: Peeling rate is 20% or less ×:
Those with a peeling rate exceeding 20% (Examples 1 to 14) Predetermined amounts of zirconium tetraalkoxide, nitrogen-containing compound, and isopropyl alcohol (hereinafter referred to as IPA) shown in Table 1 were supplied to a separable flask, and the mixture was heated to room temperature. for 15 hours at a stirring speed of 800 rpm.
A stabilized alcoholic solution of zirconium tetraalkoxide was obtained by stirring. A predetermined amount of the calcium compound shown in Table 1 was added to the alcohol solution obtained, and the mixture was stirred at room temperature for 24 hours at a stirring speed of 800 rpm to obtain a ZrO2-CaO coating composition. The obtained ZrO2-Ca
Using the O-based coating composition, various physical properties were measured based on the measurement method described above, and the results are shown in Table 1. (Example 15) As shown in Table 1, a ZrO2-CaO based coating composition was obtained in the same manner as in Example 1 except that the amount of IPA added was changed. [0029] In the obtained ZrO2-CaO-based coating composition, 20% by weight of the total ZrO2-CaO-based oxide (total amount of oxide formed from zirconium tetraalkoxide and calcium compound and CaZrO3 powder) was added. A corresponding amount of CaZrO3 powder (average particle size 1μ
m) and stirred at room temperature for 1 hour at a stirring speed of 1000 rpm.
Stir with CaZrO3 powder containing ZrO2-CaO
A system coating composition was obtained. [0030] Obtained CaZrO3 powder-containing ZrO2
Using the -CaO-based coating composition, each physical property was measured based on the measurement method described above, and the results are shown in Table 1. (Example 16) A ZrO2-CaO based coat containing CaZrO3 powder was prepared in the same manner as in Example 15 except that the amount of CaZrO3 powder added was 40% by weight.
A tinging composition was obtained. [0031] Obtained CaZrO3 powder-containing ZrO2
Using the -CaO-based coating composition, each physical property was measured based on the measurement method described above, and the results are shown in Table 1. [Table 1] (Comparative Examples 1 to 8) Predetermined amounts of zirconium tetraalkoxide, nitrogen-containing compound, and IP shown in Table 2
A ZrO2-CaO based coating composition was obtained in the same manner as in Example 1 using A and a calcium compound. Using the obtained ZrO2-CaO-based coating composition,
Each physical property was measured based on the above measurement method, and the results are shown in Table 2. (Comparative Example 9) A ZrO2-CaO based coating composition containing CaZrO3 powder was obtained in the same manner as in Example 15, except that the amount of CaZrO3 powder added was 70% by weight. [0034] Obtained CaZrO3 powder-containing ZrO2
Using the -CaO-based coating composition, each physical property was measured based on the measurement method described above, and the results are shown in Table 2. [Table 2] (Examples 17 to 28) Predetermined amounts of zirconium tetraalkoxide shown in Table 3, nitrogen-containing compound,
A ZrO2-CaO based coating composition was obtained in the same manner as in Example 1 using IPA and a calcium compound. Using the obtained ZrO2-CaO-based coating composition, each physical property was measured based on the measurement method described above, and the results are shown in Table 3.
It was shown to. [Table 3] [Effects of the Invention] The composition of the ZrO2-CaO-based coating composition of the present invention is as described above, and contains a specific zirconium tetraalkoxide, a calcium compound, an organic solvent, and an amine. Because it contains a specific amount of at least one nitrogen-containing compound selected from the group consisting of chemical compounds, ethylenediamine derivatives, pyridyl alcohol derivatives, and bipyridine, it can be stored for a long time and can be stored in metals, plastics, wood, paper, and cement. Coating films with excellent corrosion resistance, heat resistance, abrasion resistance, and insulation properties can be easily formed on various materials such as graphite.

Claims (1)

[Claims] Claim 1: (a) a zirconium tetraalkoxide represented by the general formula Zr(OR1)4 (in the formula, R1 represents an alkyl group having 1 to 5 carbon atoms), (b) calcium chloride, calcium bromide, and a calcium compound selected from the group consisting of calcium iodide; (c) a nitrogen-containing compound selected from the group consisting of an amine compound represented by the following general formula (I) or (II), an ethylenediamine derivative, a pyridyl alcohol derivative, and bipyridine; Compound,
and [Formula 1] (wherein, R2 is an alkyl group having 1 to 5 carbon atoms, R3 is an alkyl group having 1 to 5 carbon atoms or hydrogen, and R4 is an alkyl group having 2 to 5 carbon atoms.
~5 alkylene group) (d) consists of an organic solvent, and the molar ratio of each of the above components is (b) / (a) = 0.
01-2. 5, (c) / (a) = 0. 5-6 and ((d)/(a)+(b))=0. 05-5
00. A ZrO2-CaO based coating composition.