JPH04102411A - Coated dish - Google Patents

Abstract

PURPOSE:To form a high-hardness coating film on a metallic dish while keeping heat resistance by coating a heat resistant paint consisting of the alkoxide of metal selected out of polymetallocarbosilane, titanium, zirconium, aluminum, or the like on a metallic dish and then by baking it. CONSTITUTION:The polymetallocarbosilane in this invention is an organic silicon polymer that itself is officially recongnized. As an embodiment of silicone resin, denaturated silicone that has been reacted with a denaturation resin such as epoxy resin is given. As inorganic fillers, at least one kind out of oxide, boride, or the like is used. As an embodiment of alkylalkoxysilane, methyltrimethoxysilane or the like can be given. As an embodiment of the alkoxide of metal selected out of titanium, zirconium, aluminum, or the like, tetraethoxytitanium or the like can be given. There is no special restriction in the raw material of the metallic dish on which the heat resistant paint of this invention is coated and baked, and also in the method for coating and baking.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a coated plate having a heat-resistant and highly hard heat-resistant coating formed on its surface.

(Prior art and its problems) Japanese Patent Application Laid-Open No. 62-54768 discloses a heat-resistant paint in which polymetallocarbosilane, silicone resin, and inorganic filler are dispersed or dissolved in an organic solvent. The heat-resistant paint described in the above-mentioned publication can be baked in air, and the coating film obtained therefrom has the advantage of not only excellent heat resistance but also good corrosion resistance and impact resistance.

On the other hand, the coating film obtained by curing the polymetallocarbosilane by heating the paint described in the above-mentioned publication at a temperature of 250 to 450°C, which is the temperature for general baking, has a pencil hardness of 2H to 3.
H, has a relatively low hardness, and has a problem that needs to be solved in that the coating film is easily scratched. Therefore, the paint film obtained by baking this paint on steak plates for applications requiring surface hardness, for example, is easily scratched by knives and forks (and the paint film is likely to peel off in a relatively short period of time).

(Technical means for explaining the problem) The present invention provides a coated plate in which a highly hard coating film is formed on a metal plate while maintaining the excellent heat resistance of a polymetallocarbosilane paint.

According to the present invention, a heat-resistant paint consisting of a polymetallocarbosilane, a silicone resin, an inorganic filler, an alkyl alkoxysilane, and an alkoxide of a metal selected from titanium, zirconium, and aluminum is painted and baked on a metal plate. A paint applicator is provided.

The polymetallocarbosilane used in the present invention is an organosilicon polymer known per se, 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 JP-A No. 37139 and JP-A No. 63-49691. The descriptions in these publications are incorporated herein by reference.

A typical method for producing polymetallocarbosilane is a method in which a polycarbosilane having a number average molecular weight of 200 to 1000 is reacted with a titanium or zirconium alkoxide. Through this reaction, polycarbosilane is a crosslinked polymer with a number average molecular weight of 700 to 100°000, in which some of the silicon atoms in its skeleton are bonded via oxygen atoms with titanium atoms or zirconium atoms. A metallocarbosilane is obtained.

An organic solvent solution of the above-mentioned polymetallocarbosilane is commercially available from Ube Industries Ltd. as Tyrannocoat [F] Fes Type.

Specific examples of the silicone resin in the present invention include dimethylpolysiloxane, methylphenylpolysiloxane,
Pure silicone resins such as diphenylpolysiloxane, pure silicone resins, alkyd resins, polyester resins,
Examples include modified silicones reacted with modifying resins such as acrylic resins and epoxy resins.

The blending ratio of the silicone resin is 10 to 900 parts by weight, particularly 50 to 900 parts by weight, per 100 parts by weight of polymetallocarbosilane.
Preferably, it is 500 parts by weight. If the blending ratio of silicone resin is too small, the flexibility of the coating film will decrease due to baking, and if the ratio is too high, the heat resistance and corrosion resistance of the coating film will decrease due to baking. .

As the inorganic filler in the present invention, at least one selected from oxides, borides, phosphates, silicates, silicides, borides, nitrides, and carbides is used. Examples include 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. Examples include borates, phosphates, and silicates.

The blending ratio of the inorganic filler is polymetallocarbosilane 10
0 parts by weight, 10 to 900 parts by weight, especially 50 to 50 parts by weight
By blending the inorganic filler, which is preferably 0 parts by weight, the adhesion of the coating film to the base material during baking will improve, but if the blending ratio becomes too high, the flexibility of the coating film will decrease. .

The alkylalkoxysilane in the present invention has the formula R' M Si (OR") 4-a (wherein R
1 and R2 each represent an alkyl group, n represents 1-3. ) are generally used. Specific examples thereof include methyltrimethoxysilane, ethyltrimethoxysilane, butyltriethoxysilane, methyltripropoxysilane, dimethyljethoxysilane, diethyldibutoxysilane, triethylethoxysilane, and trimethylbutoxysilane.

The blending ratio of alkyl alkoxysilane is 0.2 to 10 mol per 100 g of polymetallocarbosilane.
．． The amount is preferably 5 to 5 mol. If the blending ratio of alkyl alkoxysilane is too small, the hardness of the painted film will not be sufficient, and if the blending ratio is too large, the initial adhesion of the painted film to the substrate will decrease.

The metal alkoxide selected from titanium, zirconium and aluminum in the present invention has the formula R", M (OR') 4-s (wherein R3 and R4 each represent an alkyl group, and M is titanium or represents zirconium, m is 1 to 3), or a compound represented by the formula R', Al (O
A compound represented by R') s- (wherein Rs and R6 each represent an alkyl group, and p is 1 to 2) is used. Specific examples thereof include tetraethoxytitanium, tetrabutoxytitanium, tetramethoxyzirconium, tetraproboxyzirconium, tetrabutoxyzirconium, methyltributoxytitanium, dimethyljethoxytitanium, ethyltributoxyzirconium,
Examples include dimethyldibutoxyzirconium, trimethyltriethoxytitanium, triethoxyaluminum, tributoxyaluminum, and tripropoxyaluminum.

The mixing ratio of the above metal alkoxide is 0.1 to 5 mol, particularly 0.1 to 5 mol, particularly 0.1 to 5 mol, per 100 g of polymetallocarbosilane.
If the blending ratio of the metal alkoxide is preferably 25 to 2 mol, the hardness of the paint film will not be sufficient, and if the blending ratio is too high, the stability of the paint will be impaired, resulting in short-term Gells during storage.

The above coating components in the present invention are used after being dispersed or dissolved in an organic solvent. Any organic solvent can be used as long as it is capable of dissolving polymetallocarbosilane and silicone resin. Specific examples include toluene, xylene, n-butanol, isobutanol, butyl acetate, mineral spirit, solvent naphtha, ethyl cellosolve, and cellosolve acetate.

The proportion of the organic solvent to be used varies depending on the type and blending proportion of the film-forming components, and can be appropriately determined by those skilled in the art in accordance with the disclosure of the present invention.

There are no particular restrictions on the material of the metal plate on which the heat-resistant paint is baked in in the present invention, but cast iron and stainless steel are usually used.

There is no particular restriction on the size of the metal plate, and various sizes can be used depending on the purpose of use.

There is no particular restriction on the method of applying and baking the heat-resistant paint on a metal plate in the present invention, and the coating is applied by a method known per se such as brush coating, roll coating, spraying, or dipping, and then dried and baked. .

The coating amount of the heat-resistant paint is preferably 20 to 100 g/rrr; if the coating amount is too small, pinholes are likely to occur in the coating film, resulting in a decrease in corrosion resistance.

On the other hand, if the coating amount is excessively large, the coating film is likely to crack when exposed to high temperatures or cold/heat cycles.

The baking temperature is preferably 150°C or higher, especially 200°C or higher. If the baking temperature is too low, the polymetallocarbosilane, which is one of the paint components, will not harden sufficiently and the strength of the paint film will deteriorate. As the impact resistance decreases, so does the impact resistance.

(Example) ゛Examples and comparative examples are shown below. Unless otherwise mentioned in the examples, "%" and "part" respectively refer to "
"% by weight" and "parts by weight" are shown.

The pencil hardness of the formed coating film was measured according to JIS K 5400.

Further, the heat resistance of the coating film was evaluated as follows.

That is, the object to be painted is kept in an air oven at 1000°C for 200 hours, then taken out of the oven and slowly cooled in the air, then a one-inch cross cut is made in the coating film with a cutter knife, and this area is covered with adhesive cellophane. A tape was applied, and after the tape was rapidly removed, the presence or absence of peeling of the paint film was examined. Those in which no peeling of the coating film was observed were rated as "good" in heat resistance, and those in which peeling was observed at least in part were rated as "poor" in heat resistance.

Example 1 100 parts of a 50% xylene solution of polytitanocarbosilane (manufactured by Ube Industries, Ltd., Tyrannocoat 0 varnish type), 100 parts of a 50% xylene solution of methylphenylpolysiloxane (manufactured by Toshiba Silicone Corporation, TSR-116), carbonized 100 parts of silicon powder, 150 parts of methyltrimethoxysilane,
A heat-resistant paint was prepared by mixing 250 parts of tetrabutoxytitanium and 70 parts of xylene using a mixer.

Separately, a stainless steel plate (SUS 316L) with a thickness of 0.6++ on was degreased with acetone as a base material and then air-dried.

Approximately 30μ of the heat-resistant paint is applied to the base material using a spray gun.
It was coated to a uniform thickness, baked in an air oven at 300''C for 25 minutes, and then slowly cooled.

The pencil hardness of the formed coating film was 9H or higher.

Moreover, the heat resistance of this coating film was "good".

Example 2 Example 1 was repeated, except that 400 parts of tetrabutoxyzirconium was used instead of tetrabutoxytitanium.

The pencil hardness of the resulting coating film is 9H or higher, and the heat resistance is "
It was "Good".

Comparative Example 1 Example 1 except that tetrabutoxytitanium was not blended
repeated.

The pencil hardness of the resulting coating film was 2H, and the heat resistance was "good".
Met.

Example 3 Example 1 was repeated except that 200 parts of silicon nitride powder was used instead of silicon carbide powder.

The pencil hardness of the resulting coating film is 9H or higher, and the heat resistance is "
It was "Good".

Example 4 Example 1 was repeated except that 50 parts of zirconium oxide powder was used instead of silicon carbide powder.

The pencil hardness of the resulting coating film is 9H or higher, and the heat resistance is "
It was "Good".

Claims (1)

[Claims] A coated plate in which a heat-resistant paint consisting of a polymetallocarbosilane, a silicone resin, an inorganic filler, an alkyl alkoxysilane, and an alkoxide of a metal selected from titanium, zirconium, and aluminum is painted and baked on a metal plate.