JPS62256873A - Film-forming composition - Google Patents

Abstract

PURPOSE:To obtain a film-forming compsn. having excellent heat resistance, adhesion and film-forming properties, consisting mainly of an organosilicon condensate having no terminal silanol group, frit and a specified metallic powder. CONSTITUTION:A compsn. consists mainly of an organosilicon condensate (A) having no terminal silanol group obtd. by hydrolyzing a mixture of an organosilicon compd. of formula I (wherein R is a 1-8C hydrocarbon group) and/or its lower condensate and an organosilicon compd. of formula II (wherein R' is a 1-2C hydrocarbon group) and/or its low condensate in the presence of an acid catalyst, adjusting the pH of the mixture to not lower than 7 by adding an alkaline material and condensing the products, frit (B) and at least one metallic powder (C) selected from the group consisting of zinc, manganese and lead powders. If desired, an inorg. pigment, starting materials for glass, inorg. additives, etc., may be added thereto.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention provides a composition that forms a film with good heat resistance, adhesion, and film-forming properties, which is mainly composed of an organosilicon condensate, a frit, and a metal powder. Regarding.

[Prior Art] Conventionally, it has been known to use organosilicon resins such as polydimethylsiloxane J3111)t (or polymethylphenylsiloxane resin) and alkyl silicate resins as vehicle components of film-forming compositions with excellent heat resistance. It is being

However, when the film formed from the polydimethylsiloxane resin or the like is exposed to high temperatures of 300'C or higher, organic groups such as methyl groups and phenyl groups in the resin are detached and volatilized. This has the disadvantage that the internal stress of the coating increases, the adhesion to the substrate is poor, and cracking and peeling occur. On the other hand, coatings formed from alkyl silicate resins have excellent heat resistance, but are poor in film forming properties, resulting in a thin film finish, and have the drawback of not being able to exhibit sufficient coating performance. Furthermore, in addition to the above-mentioned organosilicon resins, organosilicon resins having no terminal silanol groups are used as vehicle components,
Furthermore, although inorganic coating compositions for use in combination with metal powder have been proposed, they have problems with film-forming properties and have not been applied in cases where thick films are required.

[Problems to be Solved by the Invention] The present invention has been made for the purpose of providing a film-forming composition that forms a film with excellent film-forming properties and heat resistance.

[Means for Solving the Problem] As a result of repeated studies in order to obtain a film-forming composition that improves the conventional drawbacks, the present inventors added a frit component to the organosilicon resin that does not contain the terminal silanol group. The present invention was completed based on the discovery that the combined composition exhibits excellent film-forming properties and heat resistance.

That is, the present invention provides [A] an organosilicon compound represented by the following general formula (I) and/or a low condensate thereof, and R-0-5i -
0-R-・-・-(1) (In the formula, R represents a hydrocarbon group having carbon a1 to a8) An organosilicon compound represented by the following general formula (II) and/
or its low condensate R' R-0-S i -0-R... (TI)
(However, R' is a hydrocarbon group having 1 to 12 carbon atoms, and R is the same as above.) After hydrolyzing a mixture consisting of (R' is the same as above) in the presence of an ugly catalyst,
An organosilicon condensate having no terminal silanol group obtained by adding an alkaline substance to adjust the pH to 7 or higher and condensing the product, [B] frit, and [C] at least one metal selected from zinc, manganese, and lead. The present invention relates to a film-forming composition containing powder as a main component, and further containing inorganic pigments, glass raw materials, inorganic additives, etc., if necessary.

The organosilicon condensate used in the present invention is an organic compound having no terminal silanol group obtained by condensing a mixture of organosilicon compounds represented by the following general formula (1) and the following general formula (II) or a lower condensate thereof. It is a silicon high condensate.

R-0-S i -0-R-''・(E) (wherein, R
represents a hydrocarbon group having 1 to 8 carbon atoms) R/ R-0-S i -0-R (II) (wherein, R/ represents a hydrocarbon group having 1 to 1z carbon atoms) , R represents the same meaning as above) In the present specification, R in general formula (I) is the same or different hydrocarbon group having 1 to 8 carbon atoms.

Examples of the hydrocarbon group in this case include furkyl groups such as methyl, ethyl, propyl, and hexyl, heptalyl groups such as phenyl, tolyl, and xylyl, and cycloalkyl groups such as cyclohexyl, cyclobutyl, and cyclopentyl. A
Examples of physical compounds include tetramethoxysilane,
Examples include tetraethoxysilane, tetrapropioxysilane, tetrabutoxysilane, and tetraphenoxysilane. Moreover, the low condensate means an oligomer having a degree of polymerization of 10 or less.

Further, R in the organosilicon compound represented by the above general formula (TI) is the same as in the above general formula (I).

On the other hand, R' is a hydrocarbon group having 1 to 12 carbon atoms bonded to silicon through a carbon-silicon bond, and examples of the hydrocarbon group include alkyl groups such as methyl, ethyl, propyl, hexyl, and octyl, phenyl, tolyl, xylyl, These include aryl groups such as naphthyl, and cycloalkyl groups such as cyclohexyl, cyclobutyl, and cyclopentyl.

Specific compounds include methyltrimethoxysilane,
Examples include methyltriethoxysilane, phenyltrimethoxysilane, and phenyltriethoxysilane.

When condensing the mixture of the organosilicon compounds represented by the above general formulas (I) and (II) and/or their low condensates, first, the mixture of the compounds and/or low condensates is mixed with a water-soluble solvent such as an alcoholic solvent. , cellosolve-based solvents, cellosolve acetate-based solvents, glyme-based solvents, etc., and in the presence of mineral acids such as hydrochloric acid, sulfuric acid, and phosphoric acid, or molar acids such as formic acid and acetic acid, preferably at a pH of 6 or less, to Si. 0.2 to 2 per mole of bonded RO group
Add water at the ratio of mou and heat at 20 to 100°C for 30 minutes.
The mixture is reacted with stirring for about 10 minutes to 10 hours to carry out hydrolysis and condensation reactions.

Next, inorganic bases such as sodium hydroxide and potassium hydroxide, alkali metal or alkaline earth metal salts of weak acids such as boric acid and molybdic acid that are soluble in water-soluble solvents and exhibit basicity (e.g. sodium borate, molybdenum aliphatic amines such as monoethylamine, diethylamine, and triethylamine, and alkaline substances such as ammonia to raise the pH of the system to 7 or more, preferably 7.5 to 8.5, and to carry out the condensation reaction to 0. After completion of the zero reaction, which is allowed to proceed for 5 to 10 hours, remaining water is removed by distillation, azeotropy, etc. to easily obtain the desired organosilicon condensate.

When obtaining a high condensate using the general formulas (I) and (I), it is appropriate to blend the surrounding components in the following proportions based on weight.

General formula (1) compound: 5 to 95% by weight, preferably 20 to 80% by weight General formula (II) compound: 5 to 95% by weight, preferably 2
0 to 80% by weight The high condensate thus obtained is a three-dimensional condensate with a degree of condensation of at least 20 or more and a molecular weight of about 3.000 or more.

The frit used in the present invention is used in ordinary enameling, and is made of refractory raw materials (silica stone,
silica sand, feldspar, etc.), meltable raw materials (borax, boric acid, boron oxide, soda ash, chili saltpetre, potassium saltpeter, lithium carbonate, potassium carbonate, calcium carbonate, barium carbonate, magnesium carbonate, calcium hydroxide, lead tan, - lead oxide, zinc white, etc.), weak opalescent raw materials (fluorite, cryolite, sodium fluoride, aluminum fluoride, sodium silicofluoride, etc.), strong opalescent raw materials (tin oxide, antimony oxide,
Antimony metal, sodium antimonate, titanium oxide, zirconium oxide, zirconium silicate, arsenite, cerium oxide, etc.), coloring materials (sulfur flower, cobalt oxide, chromium oxide).

Selected from raw materials for enamel frit such as nickel oxide, manganese dioxide, copper oxide, hardened iron monopotassium dichromate, cadmium sulfate, metallic selenium, lead chromate, etc.), and adhesives (cobalt oxide, nickel oxide, manganese dioxide, etc.) It is a frit made by

For example, Ichisaka products have frit numbers F-327, F
-501, F-540, F, -718 (manufactured by Kanto Enamel Glaze Co., Ltd.), etc.

In addition to the above-mentioned Urou frit, glass frits such as ceramic frits, electrical frits, glass sealing frits, etc. can be used. Among these, those with a firing temperature of 750°C or less, preferably around soo'c are desirable.

Commercially available products include 1 such as ASF-1305 and ASF-1.
307, ASF-1301 (manufactured by Asahi Glass Co., Ltd., product name), 4305, LW-75, LW-77, 5T-02 (
The above products are manufactured by Nippon Enamel Glaze Co., Ltd.).

Organosilicon condensate [A], frit) [B] and zinc,
At least one metal powder selected from manganese and lead [C
The blending ratio of the three components is such that when the weight of the dry coating film is 100, the weight of the organosilicon condensate is 2 to 40% by weight, preferably 5 to 20% by weight. If the amount is less than 2 parts by weight, the hardness will not be high and the water resistance will be poor. Further, if it is more than 40% by weight, cracking tends to occur.The amount of frit can be added from 10 to 95% by weight, but preferably from 50 to 90% by weight.

If the amount is less than 10% by weight, it becomes difficult to form a glassy film, which causes peeling at high temperatures. In addition, the amount of at least one metal powder selected from zinc, manganese, and lead, which does not have hardness at 95% or more, can be added in an amount of 1 to 50% by weight, but 5 to 2% by weight.
0% by weight is preferred.

If it is less than 1%, water resistance and hardness are insufficient.

In addition to the above-mentioned components, inorganic pigments, raw materials for glass, inorganic additives, etc. may be added to the film-forming composition of the present invention, if necessary.

As inorganic pigments, for example, titanium white, red iron, alumina, red lead, yellow lead, carbon black, cyanine blue, zinc white, etc. can be used as coloring agents, and as extender pigments, talc, tancal, clay, mica, baryta, feldspar can be used. etc. can be used. Further, red lead, basic chromium-drowned zinc, cyanamide, etc. can also be used for rust prevention purposes.

As raw materials for glass, silica, feldspar, silica sand, alumina, aluminum hydroxide, kaolin, lebidolite, petalite, subodumene, boric anhydride, borax anhydride, colemanite, lasolite, borax, soda ash, chili saltpeter, potassium saltpetre, potassium carbonate, carbonic acid. Lithium, limestone, dolomite, magnesite, magnesium hydroxide, talc, quicklime, slaked lime, strontium carbonate, barium carbonate, barium sulfate, peroxide/helium, barium sulfate, barite, red lead, litharge, silicate , calcium phosphate, sodium phosphate, aluminum phosphate, titanium white, zinc white, zirconium oxide,
Beryl oxide, germanium oxide, tin oxide, cadmium oxide, thallium oxide, bismuth oxide, red iron oxide, arsenic oxide, antimony oxide, cobalt pentoxide, nickel, 5
nickel, iron powder, chromium oxide, potassium orthochromate, manganese dioxide, potassium permanganate, vanadium pentoxide,
Selenium, sodium selenite, barium selenite, cupric oxide, copper sulfate, iron sulfide, sodium sulfide, fluorite, sodium silicofluoride, cryolite, barium nitrate, barium peroxide, antimony oxide, sodium sulfate, Examples include barium sulfate and magnesium mirabilite carbonate. When such raw materials are used in combination, a glass film is easily formed at temperatures of 500°C or higher.

In addition, as inorganic additives, it is recommended to use clay, bentonite, Erosil, etc. to suppress the settling of pigments, and asbestos, etc. to prevent cracking of the paint film.
Glass fiber, glass powder, and glass flakes can also be used together.

[Function] Film-forming properties, #
It is thought to have excellent thermal properties.

[Examples] Hereinafter, the present invention will be explained in more detail with reference to Examples and Comparative Examples. Note that 1 part and % indicate parts by weight and % by weight.

Example of producing organosilicon condensate: In a reaction vessel, 62 g of tetraethoxysilane, 150 g of methyltrimethoxysilane, and 212 g of ethyl alcohol.
was added, and the contents were heated to 80° C. while stirring, and then 20 g of 0.2N hydrochloric acid was added and reacted at 80° C. for 10 hours. Next.

20 g of triethylamine was added to this reaction product and p
) Raise I to 7 or more and perform the linearization reaction at 80°C for 2 hours, then add 100g of benzene to reduce the non-volatile content to 40%.
(% by weight, the same applies hereafter).

The reaction product thus obtained was transparent and had a viscosity of 4.2 centiboise.

Example 1 Organosilicon condensate of production example 80.0 parts Glass frit 4305 80.0 (manufactured by Nippon Enamel Glaze Co., Ltd.) Zinc powder 5. .

Cellosolve 10.0 Alumina
4.0149.0 Example 2 Organosilicon condensate of production example 150.0 parts Glass frit 4305 45.0 (same as Example 1) Glass frit ASF-130545.0 (manufactured by Asahi Glass Co., Ltd.) Manganese 10.0 oxidation Molybdenum 2.0192.0 Example 3 Organosilicon condensate of production example 120.0 parts Glass frit LW-77100.0 (manufactured by Nippon Enamel Glaze Co., Ltd.) Manganese 15.0 Cobalt sulfuride 1.0 Red iron
5.0 feldspar
10.0 is a barrel stone 2
．． 0 Silica powder 5.0 Cellosolve 10.0218.0 After dispersing in a ball mill for 24 hours excluding metal powders and metal oxides from the above four types of formulations, add metal powders and metal oxides corresponding to the formulations. A composition of the present invention was obtained.

Comparative example I 66% ethyl silicate hydrolysis 50.0 Partially dissolved product 1 Glass frit 4305 80.0 (manufactured by Nippon Enamel Glaze Co., Ltd.) Zinc powder 5.0 Cellosolve
10.0 alumina
4.0149.0 Book 1 A mixture consisting of 100 parts of ethyl silicate (manufactured by Nippon Full Coat Chemical Co., Ltd., polymerization degree 4 to 6.5 i02 min 40%), 9 parts of isopropyl alcohol, and 10 parts of IN-hydrochloric acid was reacted at room temperature for 24 hours. Hydrolyzed.

The hydrolysis rate of the obtained ethyl silicate was 66%, and the nonvolatile content was 20%.

Comparative Example 2 50% polymethylphenyl poly 66.0 parts Siloxane Glass Frift 4305 80.0 (manufactured by Nippon Enamel Glaze Co., Ltd.) Zinc dust 5.0 Ceronlube 10.0 Alumina
4.0149.0 A paint was prepared by dispersing the above composition in the same manner as in the example.

Test pieces were prepared by applying the paints obtained in the above examples and comparative examples to sandblast M plates with a brush and drying them at room temperature. The test results are shown in Table 1.

[Test Items] Hardness The pencil hardness of the paint film was measured after drying it for one week.

Cracking limit film thickness Dry film thickness is 1O120, 50, 100,
A total of 200 liters of each was applied, and the coatings were dried at room temperature for 5 days to determine the thickness up to which cracking would not occur.

Water Resistance After drying at room temperature for one week, it was immersed in water for 30 days and then pulled out to examine the softening of the coating film.

After allowing the coating to dry at room temperature for 5 days, cross-cuts were made with a knife and adhesive tape, and the coating was peeled off with sellotape to see if it would adhere to it.

Heat Resistance After being placed in an electric furnace at 400°C and 600°C for 2 hours, it was left at room temperature and observed for cracking or peeling.

Heating Residue After the coating film was dry-exploded for 5 days, it was placed in an electric furnace at 400° C. for 24 hours, and the heating residue (%) at that time was determined.

[Effects of the present invention] The film obtained from the composition of the present invention exhibits excellent film-forming properties and heat resistance.

Claims (1)

[Claims] 1. [A] An organosilicon compound and/or a low condensate thereof represented by the following general formula (I) and ▲There are numerical formulas, chemical formulas, tables, etc.▼...(I) (wherein, (R represents a hydrocarbon group having 1 to 8 carbon atoms) Organosilicon compounds and/or low condensates thereof represented by the following general formula (II)▲There are mathematical formulas, chemical formulas, tables, etc.▼……(II) (However, R′ is a hydrocarbon group having 1 to 12 carbon atoms, R is the same as above) After hydrolyzing a mixture consisting of the following in the presence of an acid catalyst,
An organosilicon condensate having no terminal silanol group obtained by adding an alkaline substance to adjust the pH to 7 or higher and condensing the product, [B] frit, and [C] at least one metal selected from zinc, manganese, and lead. A film-forming composition containing powder as a main component and further containing inorganic pigments, glass raw materials, inorganic additives, etc.