JPH04309579A - Zro2-sio2-cao coating composition - Google Patents

Abstract

PURPOSE:To prepare a coating compsn. which can be stored for a long time and can easily form a coating film excellent in resistance to heat, abrasion, water, and chemicals on various substrates such as metal, plastic, wood, paper, cement, and graphite. CONSTITUTION:The title compsn. comprises 1mol of a zirconium tetraalkoxide, 0.01-9mol of a tetraalkoxysilane, 0.01-9mol of a calcium compd. selected from the group consisting of calcium chloride, calcium bromide, and calcium iodide, 0.5-6mol of a diamine compd. selected from the group consisting of ethylenediamine and derivs. thereof or 0.5-6mol of a pyridine compd. selected from the group consisting of pyridyl alcohol, derivs. thereof, and bipyridine, and an org. solvent in a molar ratio to the sum of the zirconium tetraalkoxide and the tetraalkoxysilane of 0.05-500.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to ZrO2-SiO2-
The present invention relates to a CaO-based coating composition.

0002

[Prior art] Conventionally, metal, plastic, wood, paper,
On materials such as cement and graphite, its heat resistance, abrasion resistance,
In order to improve water resistance, chemical resistance, etc., coatings are used to form coatings. Typical coating methods include, for example, organic coatings using silicone resin as a binder. An example is coating with paint. However, the coating film obtained from the above organic paint is
It 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]

SUMMARY OF THE INVENTION 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, has excellent stability, and can be stored for a long period of time. An object of the present invention is to provide a ZrO2-SiO2-CaO based coating composition.

[0006]

[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, since the stability of the SiO2-CaO 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.

The tetraalkoxysilane (b) used in the present invention is a compound represented by the general formula Si(OR2)4, in which R2 represents an alkyl group, and as the number of carbon atoms increases, ZrO2- The number of carbon atoms is limited to 1 to 5, since the stability of the SiO2-CaO coating composition decreases and its long-term storage stability deteriorates.

Examples of the above-mentioned tetraalkoxysilane (b) include tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, and tetra-is
o-propoxysilane, tetra-n-butoxysilane,
Tetra-sec-butoxysilane, Tetra-tert-
Examples include butoxysilane, with tetraethoxysilane and tetramethoxysilane being particularly preferred. these are,
They may be used alone or in combination of two or more.

[0010] If the amount of the tetraalkoxysilane (b) added to the zirconium tetraalkoxide (a) is too small, the stability of the ZrO2-SiO2-CaO coating composition will decrease, resulting in poor long-term storage. If this happens, cracks are likely to occur in the resulting coating film, so the molar ratio of tetraalkoxysilane (b)/zirconium tetraalkoxide (a) is limited to 0.01 to 9, preferably 0.1 to 6.

Calcium compound (c
) is a compound selected from the group consisting of calcium chloride, calcium bromide and calcium iodide, and examples of the calcium compound (c) 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.

[0012] Even if the amount of the calcium compound (c) 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 01 to 9, preferably 0.1 to 4.0.

The diamine compound used in the present invention is one or more compounds selected from the group consisting of ethylenediamine and ethylenediamine derivatives. Examples of the ethylenediamine derivatives include N-methylethylenediamine, N-ethylethylenediamine, N,N'-dimethylethylenediamine, N,N'-diethylethylenediamine, and N-ethyl-N'-hydroxyethylethylenediamine.

[0014] If the amount of the diamine compound (d) added to the zirconium tetraalkoxide (a) is small, the stability of the ZrO2-SiO2-CaO coating composition will be reduced and the long-term storage stability will be poor; The diamine compound (d)/zirconium tetraalkoxide (a) (molar ratio) is limited to 0.5 to 6 because cracks are likely to occur in the resulting coating film.

The organic solvent (e) used in the present invention is:
It is not particularly limited as long as it is compatible with the zirconium tetraalkoxide (a) and the tetraalkoxysilane (b) and shows solubility in the calcium compound (c). For example, methyl alcohol, ethyl alcohol, etc. Examples include alcohols such as alcohol, isopropyl alcohol, and butyl alcohol, 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.

[0016] If the amount of the organic solvent (e) added is too small, the stability of the ZrO2-SiO2-CaO coating composition will be reduced, resulting in poor long-term storage stability, while if it is too large, pinholes will appear in the resulting coating film. organic solvent (d) / [zirconium tetraalkoxide (
a) + tetraalkoxysilane (b) ] (molar ratio)
is 0. 05 to 500, preferably 0.05 to 500, preferably 0. 2~
It is 300.

The method for producing the ZrO2-SiO2-CaO-based coating composition of the present invention is not particularly limited. After mixing, the remaining constituent materials are added and mixed.
The latter method is preferred; for example, after mixing zirconium tetraalkoxide (a), diamine compound (d) and organic solvent (e) as specific constituent materials, tetraalkoxysilane (b) and calcium compound (c) are added. The method will be adopted. Next, present invention 2
The following describes the ZrO2-SiO2-CaO based coating composition.

In the composition of the second invention, one or more pyridine compounds (d) selected from the group consisting of pyridyl alcohol, pyridyl alcohol derivatives and bipyridine are used in place of the diamine compound (d). It will be done.

The above pyridyl alcohol derivatives include:
For example, pyridyl alcohol, 2-pyridyl carbino
alcohol, α-(2-pyridyl)ethyl alcohol, β-(2-pyridyl)ethyl alcohol,
-pyridyl)ethyl alcohol, etc., and examples of bipyridine include 2,2'-bipyridine, 2,3'-
-bipyridine, 2,4'-bipyridine, 3,3'-bipyridine, 3,4'-bipyridine, 4,4'-bipyridine and the like.

[0020] If the amount of the pyridine compound (d) added to the zirconium tetraalkoxide (a) is too small, the stability of the ZrO2-SiO2-CaO coating composition will be reduced and the long-term storage stability will be poor; Since cracks are likely to occur in the resulting coating film, the pyridine compound (d)/zirconium tetraalkoxide (a) (molar ratio) is limited to 0.5 to 6.

ZrO2-SiO of the present invention and present invention 2
The composition of the 2-CaO-based coating composition is as described above, but it promotes the hydrolysis of all alkoxides (zirconium tetraalkoxide (a) and tetraalkoxysilane (b)) and facilitates the formation of a coating film. Water, acids, alkalis, etc. may be added for this purpose.

[0022] In order to further improve the stability (crack resistance, peeling resistance, etc.) of the resulting coating film, Zr, Si
, Ca, etc. oxide powder (e.g. ZrO2, SiO2
, CaO, CaZrO3, ZrSiO4, Ca3
Powder such as Si2ZrO9) may be added.

[0023] The average particle size of the above-mentioned oxide powder should be set to 0, because if it becomes small, it becomes difficult to disperse it into the ZrO2-SiO2-CaO coating composition, and if it becomes large, cracks are likely to occur in the resulting coating film. ．． 01~100μm
is preferable, and 0. Particularly preferred is 02 to 10 μm.

ZrO2-SiO2-C of the above oxide powder
If the amount added to the aO-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-SiO2-CaO-based coating composition will be reduced. Therefore, all ZrO2-SiO2-CaO-based oxides (zirconium tetraalkoxide (a), tetraalkoxysilane (
1 to 60% by weight of the total amount of the oxide formed from b) and the calcium compound (c) and the above-mentioned oxide powder). Note that the addition of the oxide powder is based on the ZrO
Preferably, this is done after mixing the constituent materials of the 2-SiO2-CaO based coating composition.

[0025] The ZrO2-SiO2-CaO based coating composition of the present invention is applied or impregnated onto the above material,
After drying, a ZrO2-SiO2-CaO-based oxide film is formed. The above-mentioned coating method is not particularly limited, and examples thereof include coating methods such as brush coating, spray coating, dip coating, spin coating, and roll coating.

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

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

[0028]

[Examples] Examples of the present invention will be described below. The evaluation method for each physical property of the ZrO2-SiO2-CaO coating composition shown in the results is as follows.

(1) Initial adhesion A slide glass (
Matsunami Co., Ltd.) was immersed in the ZrO2-SiO2-
An evaluation sample was prepared by forming a CaO-based oxide coating layer, and J
A cross-cut tape peeling test was conducted according to IS D 0202, and the ratio of the remaining squares to the squares of 100 ZrO2-SiO2-CaO-based oxide coating layers (adhesion 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-SiO2-CaO based coating composition, evaluation samples were prepared in the same manner as in the above evaluation of initial adhesion, and measured according to JISK 5400. did.

(3) Boiling Water Resistance (Crack Resistance and Adhesion Durability) Using the obtained ZrO2-SiO2-CaO based coating composition, a film was prepared in the same manner as in the above evaluation of initial adhesion. After the evaluation sample was immersed in boiling water for 8 hours, the state of its surface was subjected to a sensory test and the crack resistance was evaluated 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 initial adhesion evaluation, and adhesion was determined. The adhesion durability was evaluated based on the ratio.

(4) Acid resistance (crack resistance and adhesion durability) Evaluation made using the obtained ZrO2-SiO2-CaO coating composition in the same manner as in the above initial adhesion evaluation. After the sample was immersed in 20 wt % hydrochloric acid for 75 hours, the state of the surface thereof was subjected to a sensory test and the crack resistance was evaluated 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 initial adhesion evaluation, and the adhesion was confirmed. The adhesion durability was evaluated based on the ratio.

(5) Long-term storage property After the sealed container containing the obtained ZrO2-SiO2-CaO coating composition was left in an atmosphere of 50° C. and 65% RH for 3 months, the above initial adhesion was confirmed. An evaluation sample was prepared in the same manner as in the evaluation, a cross-cut tape peeling test was conducted, and long-term storage stability was evaluated according to the following criteria.

(Judgment criteria) ○: Adhesion rate exceeds 80% ×: Adhesion rate is 80% or less

(Examples 1 to 13) Predetermined amounts of zirconium tetraalkoxide, diamine compound, and ethyl alcohol shown in Table 1 were supplied to a separable flask, and stabilized by stirring at room temperature for 15 hours at a stirring speed of 800 rpm. An alcoholic solution of zirconium tetraalkoxide was obtained.

To the resulting alcohol solution was added the prescribed amount of tetraalkoxysilane shown in Table 1, and the mixture was stirred at room temperature for 5 hours at a stirring speed of 800 rpm. of calcium compound and stirred at room temperature for 24 hours at a stirring speed of 800 rpm to form ZrO2.
A -SiO2-CaO based coating composition was obtained.

Using the obtained ZrO2-SiO2-CaO based coating composition, various physical properties were measured based on the measurement method described above, and the results are shown in Table 1.

(Example 14) In Example 1, except that 1 molar equivalent of an aqueous hydrochloric acid solution (concentration: 3 mol/l) was added.
A ZrO2-SiO2-CaO based coating composition was obtained in the same manner as in Example 1. Obtained ZrO2-SiO2
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 15) As shown in Table 1, a ZrO2-SiO2-CaO based coating composition was obtained in the same manner as in Example 1 except that the amount of ethyl alcohol added was changed.

[0043] The obtained ZrO2-SiO2-CaO-based coating composition was coated with all ZrO2-SiO2-CaO-based oxides (oxides formed from zirconium tetraalkoxide, tetraalkoxysilane and calcium compounds, and Ca3Si2ZrO9 powder). total amount)
Ca3Si2ZrO9 powder (average particle size 1 μm) was added in an amount equivalent to 40% by weight of the mixture, and the mixture was stirred at room temperature for 1 hour at a stirring speed of 1000 rpm to form Ca3Si2ZrO9.
A powder-containing ZrO2-SiO2-CaO coating composition was obtained.

Using the obtained ZrO2-SiO2-CaO coating composition containing Ca3Si2ZrO9 powder, various physical properties were measured based on the above measurement method, and the results are shown in Table 1.

[0045]

[Table 1]

(Comparative Examples 1 to 6) ZrO2-Si was prepared in the same manner as in Example 1 using the predetermined amounts of zirconium tetraalkoxide, diamine compound, ethyl alcohol, tetraalkoxysilane and calcium compound shown in Table 2.
An O2-CaO based coating composition was obtained. Obtained Z
Using the rO2-SiO2-CaO-based coating composition, each physical property was measured based on the measurement method described above, and the results are shown in Table 2.
It was shown to.

[0047]

[Table 2]

(Examples 16-24, Comparative Examples 7-9) Table 3
The predetermined amounts of zirconium tetraalkoxide, pyridine compound, and ethyl alcohol shown in were supplied to a separable flask, and stirred at 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 tetraalkoxysilane shown in Table 3 was added to the obtained alcohol solution, and the mixture was stirred at room temperature for 5 hours at a stirring speed of 800 rpm. of calcium compound and stirred at room temperature for 24 hours at a stirring speed of 800 rpm to form ZrO2.
A -SiO2-CaO based coating composition was obtained.

Using the obtained ZrO2-SiO2-CaO based coating composition, various physical properties were measured based on the measurement method described above, and the results are shown in Table 3.

[0051]

[Table 3]

[0052]

Effects of the Invention The composition of the ZrO2-SiO2-CaO-based coating composition of the present invention is as described above, and includes zirconium tetraalkoxide, tetraalkoxysilane, and calcium compound stabilized with a specific diamine compound or pyridine compound. Contains a specific amount of organic solvent and can be stored for a long time, and can be applied to various materials such as metal, plastic, wood, paper, cement, and graphite with heat resistance, abrasion resistance, water resistance, and resistance. A coating film with excellent chemical properties can be easily formed.

Claims (2)

[Claims] Claim 1: (a) Zirconium tetraalkoxide represented by the general formula Zr(OR1)4 (wherein R1 represents an alkyl group having 1 to 5 carbon atoms), (b) Si(OR2)4 (formula In the middle, R2 has 1 carbon number
-5 alkyl group), (c) a calcium compound selected from the group consisting of calcium chloride, calcium bromide and calcium iodide, (d) selected from the group consisting of ethylenediamine and ethylenediamine derivatives. diamine compound, (e
) consists of an organic solvent, and the molar ratio of each of the above components is (b) / (a)
=0. 01-9, (c) / (a) =0. 01~
9, (d) / (a) =0. 5-6 and ((e)
/(a)+(b))=0. 05 to 500. 2. ZrO2-SiO2-Ca according to claim 1
In the O-based coating composition, a diamine compound (d
) in place of pyridyl alcohol, pyridyl alcohol
ZrO2-Si characterized by using a pyridine compound selected from the group consisting of pyridine, derivatives and bipyridine.
O2-CaO based coating composition.