JPH0570739A - Heat-resistant coating material - Google Patents

Abstract

PURPOSE:To provide the title material which forms a coating film excellent in heat resistance and adhesion to a fluororesin. CONSTITUTION:A polymetallocarbosilane, a silicone resin, an inorg. filler, and a sol. zirconium compd. are dispersed or dissolved in a mixed solvent consisting of an arom. hydrocarbon solvent and an amine solvent to give the title compsn., which is applied to a metallic or nonmetallic substrate by brushing, etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat resistant coating composition which forms a coating film having excellent heat resistance and excellent adhesion to a fluororesin.

[0002]

PRIOR ART AND PROBLEMS THEREOF JP-A-62-54768
The publication describes that a polymetallocarbosilane, a silicone resin and an inorganic filler are dispersed or dissolved in an organic solvent to form a heat resistant coating, and that this heat resistant coating forms a coating film having excellent heat resistance. ing. JP-A-2-2826
In JP-A No. 26-26, a ceramic layer in which polytitanocarbosilane, which is a main component, is ceramicized is provided on a base material such as a cooking surface of a high-temperature cooker or a wall surface of a heating chamber, and the ceramic layer is further formed on the ceramic layer. A coating provided with a layer containing fluororesin powder is disclosed. Japanese Patent Laid-Open No. 62-54768
When a fluororesin layer is formed on a coating film formed from the heat-resistant paint described in Japanese Patent Laid-Open Publication No. 2003-242200, when the temperature change from room temperature to 300 to 500 ° C. is repeatedly applied as in a high temperature cooker, the above coating is applied. The fluororesin layer formed on the film comes to be peeled off. The applicant of the present invention is polymetallocarbosilane,
Japanese Patent Application No. 2-2076, which is a heat-resistant paint having excellent heat resistance and chemical resistance, in which a silicone resin, an inorganic filler, and a soluble zirconium compound are dispersed or dissolved in an organic solvent.
No. 82 proposed. Although various solvents are described as the organic solvent in this specification, there is no description about the amine solvent, and there is no description about the combined use of the aromatic hydrocarbon solvent and the amine solvent.

[0003]

[Technical Means for Solving the Problems] The present invention provides a heat-resistant paint capable of forming a coating film having excellent heat resistance and excellent adhesion to a fluororesin layer. According to the present invention, there is provided a heat-resistant paint in which polymetallocarbosilane, silicone resin, inorganic filler, and soluble zirconium compound are dispersed or dissolved in a mixed solvent of an aromatic hydrocarbon solvent and an amine solvent. To be done.

The polymetallocarbosilane in the present invention is a known organosilicon polymer, for example, Japanese Patent Publication No. 61-4.
No. 9335, No. 62-60414, No. 63-
It can be prepared according to the methods described in 37139 and 63-49691. The descriptions of these publications are referred to as part of the present specification. A typical production method of polymetallocarbosilane has a number average molecular weight of 200 to 10
No. 00 polycarbosilane is reacted with titanium or zirconium alkoxide. By this reaction, polycarbosilane has a number average molecular weight of 700 to 100 in which a part of silicon atoms in the skeleton is bonded with titanium atoms or zirconium atoms through oxygen atoms.
000 crosslinked polymer polymetallocarbosilanes are obtained.

Specific examples of the silicone resin in the present invention include pure silicone resins such as dimethylpolysiloxane, methylphenylpolysiloxane and diphenylpolysiloxane, and conversion of pure silicone resin into alkyd resin, polyester resin, acrylic resin, epoxy resin and the like. The modified silicone reacted with the resin for use is exemplified. The mixing ratio of the silicone resin is polymetallocarbosilane 100.
10 to 900 parts by weight, especially 50 to 500 parts by weight
It is preferably part by weight. If the blending ratio of the silicone resin is too small, the flexibility of the baked coating film is lowered, and if the proportion is too high, the heat resistance and corrosion resistance of the baked coating film are lowered.

At least one selected from oxides, borides, phosphates, silicates, suicides, borides, nitrides and carbides is used as the inorganic filler in the present invention. Examples thereof are magnesium, calcium, barium, titanium, zirconium, chromium, manganese, iron, cobalt, nickel, copper, zinc, boron, aluminum, silicon oxides, carbides, nitrides, silicides, borides, lithium. , Sodium, potassium, magnesium, calcium or zinc borate, phosphate and silicate. The blending ratio of the inorganic filler is
10 to 9 per 100 parts by weight of polymetallocarbosilane
It is preferably 00 parts by weight, especially 50 to 500 parts by weight. By blending the inorganic filler, the adhesion of the baked coating film to the substrate is improved, but if the blending ratio is too high, the flexibility of the coating film is reduced.

As the soluble zirconium compound in the present invention, an organic solvent or water-soluble zirconium compound is used. Examples of zirconium compounds soluble in organic solvents include zirconium alkoxides such as tetraethoxyzirconium, tetrobutoxyzirconium, ethyltriethoxyzirconium and dimethyldimethoxyzirconium; chelating agents such as acetylacetone, dialkylglyoximes, oxines and dithizone. And a zirconium chelate compound; a zirconium fatty acid salt such as zirconium octoate and zirconium stearate. Examples of water-soluble zirconium compounds include zirconium acetate, hydroxyzirconium, zirconium carbonate and the like. In the heat resistant coating composition of the present invention, an organic solvent is used as a medium, and therefore, of the soluble zirconium compounds, the zirconium compound soluble in the organic solvent is preferable. When using a water-soluble zirconium compound, it is preferable to mix it with other coating components as a solution in which a small amount of water is dissolved.

The compounding ratio of the soluble zirconium compound is 0.1 per 100 parts by weight of polymetallocarbosilane.
It is preferably from 50 to 50 parts by weight, particularly preferably from 0.5 to 10 parts by weight. If the blending ratio of the zirconium compound is too small, the adhesion to the fluororesin will be reduced, and if the blending ratio of the zirconium compound is too large, the heat resistance of the polymetallocarbosilane will be impaired.

In the present invention, a mixed solvent of an aromatic hydrocarbon solvent and an amine solvent is used as the organic solvent. Specific examples of the aromatic hydrocarbon solvent include benzene,
Examples include toluene, xylene, and halides thereof. As the amine solvent, for example, the compounds described in "Solvent Handbook" issued by Sangyo Tosho Co., Ltd. can be used, and specific examples thereof include isopropylamine,
Examples thereof include dibutylamine, triamylamine, cyclohexylamine, diethanolamine and triethanolamine. Aromatic hydrocarbon solvent is 2 to 1 of amine solvent
It is preferable to use 0 times by weight. By using the amine solvent in combination with the aromatic hydrocarbon solvent, the adhesion of the coating film formed from the heat-resistant paint of the present invention to the fluororesin is improved. The proportion of the mixed solvent used is generally 20 to 500 parts by weight per 100 parts by weight of the film-forming component,
It can also be changed depending on the type and proportion of the coating film forming component.

The heat-resistant coating material of the present invention is applied to a non-metal base material such as a metal base material, an electric wire or ceramics, and a refractory brick by a means known per se such as brush coating, roll coater, spraying or dipping. It is dried and baked. The coating amount of the heat resistant coating is preferably ²⁰ to 100 g / m ² . If the coating amount is excessively small, pinholes are likely to occur in the coating film, and the corrosion resistance will decrease. On the other hand, if the coating amount is excessively large, cracks are likely to occur in the coating film when the coating film is exposed to high temperature or cold heat cycles. The baking temperature is preferably 150 ° C or higher, and particularly preferably 200 to 400 ° C. If the baking temperature is excessively low, the polymetallocarbosilane, which is one of the paint components, will not be sufficiently cured, and the strength of the coating film will decrease and the impact resistance will decrease.
If the baking temperature is excessively high, the coating efficiency will decrease as described above. If the object to be coated is placed in a use environment of 150 ° C. or higher after coating with the paint, the baking process can be omitted.

[0010]

EXAMPLES Examples and comparative examples are shown below. Unless otherwise specified below, “%” and “part” refer to “% by weight” and “part by weight”, respectively. The adhesion between the coating film formed from the heat-resistant paint of the present invention and the fluororesin was measured as follows. JIS K5400 (6.1
5) According to the edge test described in the above, make 11 cuts in 2 mm increments in the vertical and horizontal directions on the coating film with a cutter knife, carefully attach cellophane tape to this part, and peel off suddenly 10 times. Repeatedly, the adhesiveness was judged from the peeled state of the coating film after the test. The evaluation result is 10 × 10 = 10
It is shown by some peeling in 0 eyes. That is, a / 100 means that a pieces were peeled off within 100 eyes.

Example 1 100 parts of a 50% xylene solution of polytitanocarbosilane (manufactured by Ube Industries, Ltd., Tyrannocoat ^R varnish type),
100 parts of 50% xylene solution of methylphenyl polysiloxane (TSR-116 manufactured by Toshiba Silicone Co., Ltd.), 100 parts of silicon carbide powder, tetrabutoxyzirconium 2
A heat resistant coating was prepared by mixing 0 parts, 5 parts of xylene, and 10 parts of trimethanolamine with a mixer. Separately from this, a stainless steel plate (SUS 316L) having a thickness of 0.6 mm as a substrate was degreased with acetone and then air-dried. Approximately 3 by spray gun with heat resistant paint
Paint to a thickness of 0 μm, and in an air oven at 300 ° C for 25
After baking for minutes, it was gradually cooled. Then, on this coating film, a polytetrafluoroethylene topcoat enamel paint (manufactured by Daikin Industries, Ltd., Polyflon enamel)
EK-5109BK) is spray-coated to a film thickness of 20 to 30 μm and dried at 150 ° C. for 10 minutes,
Baking at 380 ° C. for 20 minutes. The coating film thus obtained had an adhesiveness of 0/100, and no cracks or cracks were observed in the cuts in the eyes.

Example 2 Example 1 was repeated except that 20 parts of zirconium octate was used instead of tetrabutoxy zirconium. The adhesiveness of the coating film was 2 to 3/100, and no breaks or cracks were observed at the corners.

Example 3 Instead of triethanolamine, triamylamine 10
Example 1 was repeated except that all parts were used. The adhesiveness of the coating film was 0/100, and no breaks or cracks were observed at the corners.

COMPARATIVE EXAMPLE 1 Only xylene was used without adding triethanolamine.
Example 1 was repeated except that 5 parts were used. The adhesion of the coating film was 50 to 60/100, and more than half of the eyes were peeled off.

Claims (1)

[Claims] 1. A polymetallocarbosilane, a silicone resin, an inorganic filler, and a soluble zirconium compound,
A heat resistant paint dispersed or dissolved in a mixed solvent of an aromatic hydrocarbon solvent and an amine solvent.