JPS6114184B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a film-forming composition. More specifically, the present invention relates to a film-forming composition with excellent heat resistance and adhesion that is mainly composed of an alkyl (or allyl or aryl) silicate, an organic resin, and an enamel frit. Generally, the heat resistance of paints using organic resins is approximately 400
Inorganic paints are used in cases where they deteriorate significantly at temperatures above .degree. C., and are practically desirable to be used at temperatures below that temperature, but require heat resistance at temperatures above that temperature. However, even inorganic paints have the drawback of poor adhesion to the iron base when the paint moves from a high temperature of 800°C or higher to room temperature, resulting in peeling, cracking, etc. Therefore 800
There are no paints that can withstand temperatures higher than ℃. In order to develop a paint that can be used at room temperature and temperatures below 800°C, can withstand high temperatures above 800°C, and has excellent adhesion, the inventors developed enamel that has excellent adhesion to iron and an inorganic binder for inorganic paints. Focusing on the use of alkyl (or allyl or aryl) silicates and organic resins, which are used as silicates, as a result of extensive research, we were able to obtain this film-forming composition that can withstand not only room temperature but also temperatures of 800°C or higher. Traditionally, enamel finishing is achieved by adding clay, potassium chloride, sodium nitrite, water, etc. as mill additives to enamel frits, dispersing them, painting them on the object, and baking them at around 800℃. An enamel film with excellent adhesion can be obtained. However, although it forms a continuous film in the temperature range of 800℃ or less before baking, the hardness of the coating is very low, its adhesion to the substrate is poor, and it is naturally not water resistant and easily softens with water. It is in. Therefore, it cannot be used practically unless it is treated at around 800°C. Furthermore, since this enamel frit is a type of glass, almost no cosmetic effect can be obtained even if it is dispersed. Although enamel has the above-mentioned drawbacks in the temperature range below 800℃,
By using enamel frit in combination with alkyl (or allyl or aryl) silicate, it is possible to obtain an inorganic paint that can withstand high temperatures of 800℃ or higher, has excellent adhesion, and has no defects such as cracking or peeling. Even at temperatures below °C, the defects of enamel do not appear, a hard coating film with excellent adhesion is formed, and a paint with a cosmetic effect can be obtained. Furthermore, the present inventors have discovered that by using an organic resin, a coating film with excellent gloss can be obtained at room temperature, and it is also possible to apply thick coatings, leading to the completion of the present invention. That is, the present invention provides (A) alkyl (or allyl or aryl)
Silicates, (B) enamel frits and (C) vinyl butyral resins, acrylic resins, silicone resins,
An essential component is one or more organic resins selected from polybutadiene resin, epoxy resin, urethane resin, phenolic resin, and xylene resin, and
The blending ratio of (A), (B) and (C) is 10% of (B) in the dry coating film.
~85% by weight, (A) + (C) accounts for 90~15% by weight, and
If necessary, one or more selected from pigments, raw materials for enamel frits, additives, and hardening agents are added to a mixture in which the ratio of (A)/(C) is 0.5/99.5 to 97/3 by solid weight. The present invention relates to a film-forming composition. The film-forming composition of the present invention has excellent thick coating properties and can be applied to an iron substrate or the like by brushing, spraying, or the like, and forms a film by drying at room temperature. The coating film has excellent adhesion and is glossy.
It is hard and can withstand not only room temperature but also high temperatures of over 800℃. The organic resin used as the vehicle for this film-forming composition generally decomposes thermally at a temperature of 300°C to 450°C and does not remain in the film, but the gloss and thick coating properties of the film at room temperature are determined by the use of organic resin. It is based on The composition of the present invention forms a film mainly composed of alkyl (or allyl or aryl) silicate, enamel frit, and organic resin at a temperature of 300 to 450°C or lower, and then at a temperature higher than the temperature at which the organic resin decomposes. In this case, a film is formed with a color vehicle made of alkyl (or allyl or aryl) silicate, and when the temperature exceeds 800°C, it changes to an enamel film based on enamel frits and raw materials for enamel frits. The alkyl (or allyl or aryl) silicate used in the present invention has the general formula

[Formula] (R is an alkyl group having 1 to 8 carbon atoms, an allyl group, or an aryl group, n is 0 or 11
These are tetraalkyl (or tetraallyl) orthosilicates or polysilicates represented by the following integers. Specifically, for example, methyl orthosilicate, ethyl orthosilicate, n-propylorthosilicate, n-
There are butyl silicate, n-octyl orthosilicate, phenyl orthosilicate, benzyl orthosilicate, phenethyl orthosilicate, allyl orthosilicate, methacryl orthosilicate, etc. Furthermore, dehydration condensation of these orthosilicates Polysilicates thus produced are also used. Among these, ethyl silicate is suitable from the viewpoint of cost. In particular, a hydrolysis rate of 30% or more is desirable from the viewpoint of drying properties. The enamel frits used with this alkyl (or allyl or aryl) silicate are those used in the production of conventional enameling, and include refractory raw materials (silica, silica sand, feldspar, etc.), fusible raw materials ( Borax, boric acid, boron oxide, soda ash, chili saltpetre, potassium saltpetre, lithium carbonate, potassium carbonate, calcium carbonate, barium carbonate, magnesium carbonate, calcium hydroxide, lead tan, lead monoxide, zinc white, etc.), weak milky white Raw materials (fluorite, cryochate, sodium fluoride, aluminum fluoride, sodium silicate, etc.), strong opalescent raw materials (tin acid, antimony oxide, antimony metal,
Sodium antimonate, titanium oxide, zirconium oxide, zirconium silicate, arsenite, cerium oxide, etc.), coloring materials (sulfur flower, cobalt oxide, chromium oxide, nickel oxide, manganese dioxide, copper oxide, iron oxide, dichromic acid) These frits are made from raw materials for enamel frits, such as potassium, cadmium sulfate, metallic selenium, lead chromate, etc.) and adhesives (cobalt oxide, nickel oxide, manganese dioxide, etc.). For example, as a commercially available product, frit number F-
327, F-501, F-540, F-718, TA-37,
(manufactured by Kanto Enamel Glaze Co., Ltd.). In addition, as the organic resin used as a color vehicle, generally known examples include vinyl butyral resin,
Acrylic resin, silicone resin, polybutadiene,
Epoxy resins, utane resins, phenolic resins, xylene resins, nitrocellulose, cellulose acetate butyrate, vinyl chloride, silicone-modified resins, etc. can be used, but urethane resins and silicone resins are preferred from the viewpoint of coating film performance at room temperature. In addition to the above-mentioned components, pigments, raw materials for enamel frit, inorganic additives, hardening agents, etc. may be added to the film-forming composition of the present invention, if necessary. As 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, etc. can be used. can be used. Furthermore, red lead, basic zinc chromate, cyanamide, etc. can also be used for the purpose of rust prevention. In the present invention, a color vehicle consisting only of alkyl (or allyl or aryl) silicate and enamel frit after the organic resin is thermally decomposed can also be used.
It is possible to enamel the entire coating film at a temperature of 800°C or higher, but if inorganic pigments, inorganic additives, etc. are added, it becomes difficult to form an enamel film over the entire surface. Therefore, if it is desired to enamelize the entire surface of the coating, the above-mentioned raw materials for enamel frit may be used in combination. Also,
Common oxide glass raw materials such as thallium, thallium oxide, bismuth oxide, cadmium oxide, indium oxide, phosphorus pentoxide, vanadium pentoxide, germanium oxide, gallium oxide, thorium oxide, and yttrium oxide are added to the raw materials for enamel frit. It's okay. Further, as additives, clay, bentonite, Erosil, hydroxyethyl cellulose, etc. may be used in order to suppress sedimentation of pigments. Furthermore, asbestos, glass fiber, glass powder, and glass flakes can also be used in combination to prevent cracking of the paint film. In addition, in order to improve the adhesion between the enamel frit and the organic resin, silane coupling agents, such as Nippon Unicar Co., Ltd.'s A-
1100A-1120, A186, A-187, A-189, etc. can also be used. Furthermore, since alkyl (or allyl or aryl) silicate and organic resin are relatively difficult to be compatible with each other, the water resistance of the coating film may be poor. In order to improve this drawback, metal powders such as zinc powder, manganese, antimony, lead, iron powder, metal silicon powder, and other powders such as gold, platinum, and silver may also be added as hardening agents. The blending ratio of the alkyl (or allyl or aryl) silicate, enamel frit, and organic resin, which are the main components of the film-forming composition of the present invention, is such that the enamel frit content in the dry coating film is 10%.
~85% by weight, preferably 50-70% by weight. The remaining 90-15% by weight is occupied by alkyl (or allyl or aryl) silicate and organic resin, and the ratio of the former to the latter is 0.5:99.5-99.5 in terms of solid content.
The range is 97:3, preferably 12:88 to 75:25. If the enamel frit content is less than 10% by weight, it will be difficult to form an enamel film at high temperatures, and if it is more than 85% by weight, the film will have low hardness. Furthermore, if the alkyl (or allyl or aryl) silicate content is too large, cracking tends to occur and a glossy coating cannot be obtained. On the other hand, if the amount is too low, peeling may easily occur at high temperatures of 400°C or higher. In addition, the proportion of pigments, raw materials for enamel frits, additives, hardening agents, etc. can be contained up to 90% by weight as a solid content in the film-forming composition, but preferably 50% by weight or less. be. When this film-forming composition is dried at room temperature and used, it can be coated with urethane resin paint, epoxy resin paint, vinyl chloride resin paint, chloride rubber paint, alkyd resin paint, etc. as a top coat to give it more cosmetic properties. . The present invention will be explained in more detail below using Examples and Comparative Examples. Note that parts and % indicate parts by weight and % by weight unless otherwise specified. Example 1 Ethyl silicate (manufactured by Nippon Colcoat Chemical Co., Ltd.,
A mixture consisting of 100 parts of polymerization degree 4-6, 100 parts of SiO ₂ min (40%), 90 parts of isopropyl alcohol and 10 parts of 1N hydrochloric acid was maintained at room temperature for 24 hours for hydrolysis. The hydrolysis rate of the obtained ethyl silicate was 66%, and the nonvolatile content was 20%. The obtained hydrolyzate of ethyl silicate (hereinafter
(abbreviated as SV-1) 30 copies, enamel frit F
-339 (manufactured by Kanto Enamel Glaze Co., Ltd.) 40 copies and retan No.
60 parts of 4026 (35% polyurethane clear manufactured by Kansai Paint Co., Ltd.) was dispersed in a ball mill for 24 hours. A film-forming composition was prepared by adding 10 parts of Rethane No. 4000 curing agent (65% polyurethane curing agent manufactured by Kansai Paint Co., Ltd.) to the obtained composition. Example 2 30 parts of SV-1 used in Example 1, 130 parts of enamel frit TA-37 (manufactured by Kanto Horo Glaze Co., Ltd.) and 50 parts of Rethane No. 4026 (same as Example 1) were mixed in a ball mill for 24 hours. Dispersed. Rethane in the resulting composition
A film-forming composition was prepared by adding 10 parts of No. 4000 curing agent (same as in Example 1). Example 3 35 parts of SV-1 used in Example 1, 150 parts of enamel frit F-339 (same as Example 1), 10 parts of red iron, 30 parts of feldspar, 10 parts of chili saltpeter, and rethane.
No.4026 (50 parts as in Example 1) was milled in a ball mill for 24 minutes.
Spread out time. To the obtained composition, 10 parts of Rethane No. 4000 curing agent (same as in Example 1) was added to obtain a film-forming composition. Example 4 60 parts of SV-1 used in Example 1, 120 parts of enamel frit F-718 (Kanto Horo Glaze Co., Ltd.), and
40 parts of SH-840 (Toray Silicone Co., Ltd., silicone resin with non-volatile content of 50%) was dispersed in a ball mill for 24 hours to obtain a film-forming composition. Example 5 40 parts of SV-1 used in Example 1, 130 parts of enamel frit TA-37 (manufactured by Kanto Horo Glaze Co., Ltd.) and a 70% epoxy resin solution (Epicoat 1001, manufactured by Ciel Chemical Co., Ltd.: toluene/methyl isobutyl ketone/ 40 parts of Cellosolve (2/1/1 mixed solvent) was dispersed in a ball mill for 24 hours. To the obtained composition, 30 parts of Tomide 410N (hardening agent manufactured by Fuji Kasei Co., Ltd.: xylene/butanol = 7/3 solution) was added to prepare a film-forming composition. Example 6 30 copies of SV-1 and enamel frit TA-37
130 parts and 25% cellulose acetate butyrate
10 parts of a solution (CAB551-1/2 manufactured by Eastman Kodak Co.: methyl ethyl ketone/ethyl acetate/cellosolve acetate = 10/50/40 mixed solvent) was dispersed in a ball mill for 24 hours to obtain a film-forming composition. Comparative Example 1 Kansai Paint SD Zinc Primer ZENo.
1500N (using ethyl silicate-based zinc-rich paint) Comparative Example 2 A film-forming composition was prepared by dispersing 140 parts of SV-1 used in Example 1, 60 parts of enamel frit TA-37, and 10 parts of cellosolve in a ball mill for 24 hours. The paints obtained in the above Examples and Comparative Examples were applied to a sandblasted steel plate with a brush and dried at room temperature to make test pieces.The test results are shown in Table 1.Hardness Paint film After letting the paint sit in a room for one week, pencil hardness was measured.Water Resistance After drying at room temperature for one week, the paint was immersed in water for five days, then pulled out and the softening of the paint film was examined.Adhesion The paint film was After letting the paint film dry for 5 days, I made a cross cut with a knife and peeled it off with cellophane tape to see if it would stick to it.Heat resistance After putting it in an electric furnace at 400℃ and 800℃ for 6 hours, I left it at room temperature to see if it would crack. Gloss: 60° gloss was measured after drying at room temperature for one week.Thick coating property: Apply several coats with a brush until the film thickness after drying is approximately 200μ, and then apply the film at room temperature for 1 week. Check for cracks after drying for a week.

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Claims (1)

[Claims] 1 (A) alkyl (or allyl or aryl) silicate, (B) enamel frit and (C) vinyl butyral resin, acrylic resin, silicone resin, polybutadiene resin, epoxy resin, urethane resin, phenolic resin, and xylene resin as an essential component,
And the blending ratio of (A), (B) and (C) is (B) in the dry coating film.
occupies 10 to 85% by weight, (A) + (C) accounts for 90 to 15% by weight, and the ratio of (A)/(C) is 0.5/99.5 to 97/ in terms of solid content weight.
A composition for forming a film, which is obtained by adding, if necessary, one or more selected from pigments, raw materials for enamel frits, additives, and hardening agents to the mixture consisting of the following. 2 Alkyl (or allyl or aryl)
The film-forming composition according to claim 1, which is a silicate or an ethyl silicate. 3. The film-forming composition according to claim 1, wherein the organic resin is a urethane resin or a silicone resin.