JPH029067B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention is a surface treatment using a composite resin as a main component, which is made by reacting an organic resin containing an alkoxy (or alkoxyalkoxy) silane group as an essential component in the resin skeleton with silica powder having a particle size of 500 mμ or less. The purpose is to apply this surface treatment composition particularly to metal surfaces to form a film having a high degree of corrosion resistance, paint base properties, abrasion resistance, stain resistance, flame retardancy, etc. The present invention relates to a method for surface treatment of metal. BACKGROUND ART Conventionally, paints containing organic resins such as alkyd resins, epoxy resins, and acrylic resins as film-forming elements have been used mainly for corrosion prevention and decoration of metals. This organic resin has the advantages of being transparent, flexible, easy to form a film, and having good covering properties. It also has drawbacks such as depletion and pollution caused by organic solvent volatilization. Recently, there has been a demand for the development of new coating materials that do not have these defects. As a material to compensate for these drawbacks, it is possible to use inexhaustible natural minerals and so-called inorganic polymers derived from them (e.g. silicates, colloidal silica, etc.); Although inorganic polymers have the advantage of forming hard films, being flame retardant, and non-polluting, they are significantly inferior to organic polymers in terms of continuous film formation, flexibility, impact strength, etc. Currently, it is not practical as a coating material because it requires baking at a high temperature of several hundred degrees when forming a film on the object to be coated. On the other hand, so-called surface treatment, a process in which metal materials are treated with a surface treatment solution such as chromate or phosphate prior to painting, is generally carried out in order to impart corrosion resistance and paint base properties. As the toxic pollution caused by these surface treatment liquids has become a social problem, improvements are desired. In order to solve various problems with the above-mentioned organic resins, inorganic polymers, and surface treatment liquids, the present inventors have combined the advantages of organic resins, such as excellent film-forming properties, coating properties, and flexibility, with the advantages of inorganic polymers. As a result of intensive research to create a completely new industrial material that has features such as excellent hardness, nonflammability, and corrosion resistance against metals, for example,
Water-dispersible colloidal silica, water-soluble or water-dispersible colloidal silica, as disclosed in Japanese Patent Publications No. 19120, No. 34406, No. 34783, and No. 34784. We have discovered that a so-called organic-colloidal silica composite composition consisting of a three-component system of a synthetic organic resin and an alkoxysilane compound satisfactorily meets the above social demands,
It has been put into practical use in many fields, primarily as a surface treatment system for metals. For example, when a metal is coated with the composition according to the invention, the resulting film is 5 to 10 times more corrosion resistant than a conventional organic resin film in a salt spray accelerated test at the same film thickness. It is also something that can be achieved. Furthermore, as a method to further improve rust prevention, a coated steel plate has been proposed in which a plated steel plate is subjected to known chromic acid treatment in advance, and then the above-mentioned composite composition invented by the applicant is coated on the surface. (For example, JP-A-57-
Publication No. 108292). However, although the film itself of the organic colloidal silica composite composition has practically satisfactory performance, it is difficult to apply the composition to a metal material as a base treatment agent (surface treatment agent). If a primer, intermediate coat, or top coat is then applied thereon, the water resistance and alkali resistance of the coated plate may be insufficient, and the adhesion of the applied coating may not be sufficient, or the composite composition coating may deteriorate. There have been cases in which problems such as lack of organic solvent resistance and dissolution in the paint after application, resulting in loss of the inherent performance of the composite film, have occurred. For example, the surface-treated steel sheet coated with the organic-colloidal silica composite composition proposed above is
Steel sheets coated on one side are used for automobile exterior panels, home appliances, etc., and steel sheets coated with organic-colloidal silica composite compositions themselves are known to exhibit excellent corrosion resistance, but these surface-treated steel sheets When applying a top coat to the surface, for example, degreasing with an alkaline cleaner to remove press oil adhering during press working, or when corrosion-resistant steel sheets for automobiles are exposed to an alkaline atmosphere during cationic electrodeposition coating. The film of the above-mentioned composite may swell or soften, resulting in deterioration of the film, which may significantly impair its adhesion to the subsequently applied coating. In addition, as a means to improve this problem, there is a method in which a crosslinking agent such as an amino resin or an epoxy resin is used in combination with the composite composition to make the formed film stronger, but even this is not sufficient. . Therefore, the present inventor investigated the cause of the above-described defects in the conventional organic-colloidal silica composite composition, particularly from the production reaction mechanism of the composite composition, and found that colloidal silica and alkoxysilane compounds are A strong covalent bond is formed by the siloxane bond that is easily formed by the dehydration condensation reaction between the silanol group (inorganic hydroxyl group) generated by hydrolysis of the compound and the silanol group on the surface of the colloidal silica particle. On the other hand, the bond between the organic resin and both components is a Juan der Walls force bond between the organic group contained in the silane compound and the organic resin, or a silanol group in the silane compound, a silanol group in colloidal silica, and a hydroxyl group in the organic resin. It was predicted that this is due to the fact that bonds weaker than the covalent bonds between the above two components, such as hydrogen bonds with carboxyl groups, amino groups, etc., are mainly formed. Based on this prediction, we have developed the latter, that is, a composite composition that forms a strong film that eliminates the above defects by forming a bond between the organic resin and the silica component that is close to a covalent bond. As a result of intensive research, we found that in each component of the composition of the organic-colloidal silica composite already proposed above, by cocondensation polymerization or graft polymerization of an alkoxysilane compound to the organic resin in advance. An organic resin containing an alkoxysilane group in its skeleton (hereinafter referred to as "silanized resin") is prepared, an alkoxysilane compound is covalently introduced into the organic resin skeleton, and then this silanized resin In the presence of water and an acid catalyst, the alkoxysilane group in the silanized resin is hydrolyzed to form a silanol group, and the silanol group and the silanol group on the surface of the silica particle are bonded to form an organic-silica. The present inventors have found that a covalent composite resin can be obtained, and that the composite resin can eliminate the various defects described above, leading to the completion of the present invention. Thus, according to the present invention, an organic resin (silanized resin) containing a di- or tri(alkoxy or alkoxyalkoxy)silane group in the organic resin skeleton and silica particles are mixed in the presence of water and an inorganic acid or an organic acid. An organic-inorganic composite resin (hereinafter referred to as "composite resin") composition formed by reacting at a temperature range of 10°C or higher and below the boiling point, or the composite resin combined with an amino resin and/or an epoxy resin. and a surface treatment method comprising applying a solution or dispersion of the composition to the surface of an object to be coated. The composite resin used in the present invention can be synthesized, for example, by the method described below. (A) A mixture consisting of water-dispersible silica, a water-soluble or water-dispersible silanized resin, water, and an inorganic or organic acid is reacted at a temperature range of 10°C or higher and lower than the boiling point. (B) A mixture consisting of organic solvent-dispersible silica, an organic solvent-soluble (or dispersible) silanized resin, an organic solvent, water, and an inorganic or organic acid is reacted at a temperature range of 10°C or higher and lower than the boiling point. The method for producing the composite resin will be explained below. (1) Silica particles The silica particles used in the present invention are preferably ultrafine amorphous silica particles with a primary particle size of 5 to 50 mμ and a secondary particle size of 500 mμ or less, and have silanol groups on the particle surface. They are classified into the following three types depending on the form of supply to the market, and any of them can be used in the present invention. (1) Fine silica powder: Generally referred to as dry silica, it has a primary particle size of 5 to 50 mμ and is produced by combustion of silicon tetrachloride. This fine silica powder is used in the form of either an aqueous dispersion or an organic solvent dispersion according to the above synthesis methods (A) and (B). Specifically, Degussa's product name
AEROSIL etc. can be used. (2) Water-dispersible silica: So-called colloidal silica, produced by desodiumization of water glass (ion exchange method, acid decomposition method, peptization method),
The primary particle size is 5 to 50 mμ, and this product is usually supplied as an aqueous dispersion, which can be used as it is in the synthesis method (A). The colloidal silica can be used in the form of an aqueous dispersion on either the acidic side or the basic side, and since the reaction with water-soluble or water-dispersible silanized resin is carried out in the acidic region, the acidic side colloidal silica, such as the product name Snowtex-O or Snowtex OL (Nissan Chemical Industries, Ltd.)
Non-stabilized silica (PH2 ~
4) is available. On the other hand, as colloidal silica on the basic side, there is silica (PH8.4-10) stabilized by the addition of trace amounts of alkali metal ions, aluminum ions, ammonium ions, or amines, and is available under the trade name Snotex.
20, Snowtex C, Snowtex N (manufactured by Nissan Chemical Industries, Ltd.), etc. (3) Organic solvent-dispersible silica used in the synthesis method (B) (hereinafter referred to as "organosilica sol")
For example, those dispersed in a lower aliphatic alcohol having 1 to 5 carbon atoms are described in US Pat. No. 2,285,449. That is, methanol or isopropanol dispersion media in which aqueous colloidal silica is substituted with an organic solvent have been practically provided, and either type can be used in the present invention. (2) Silanized resin This is used to produce a composite resin by reacting with the above-mentioned silica powder, and it has a di- or tri(alkoxy or alkoxyalkoxy) silane group (hereinafter referred to as "alkoxysilane") in the organic resin skeleton. (abbreviated as "group" for short). The silanized resin polymerizes an alkoxysilane compound having 2 to 3 alkoxysilane groups and at least one specific functional group described below in one molecule, or polymerizable unsaturated vinyl monomer. It can be obtained by copolymerizing with a polymer or reacting with an organic resin. (2)-1 Alkoxysilane compound A compound having 2 to 3 alkoxysilane groups and at least one specific functional group in one molecule, where the specific functional group is, for example, a vinyl group (CH ₂ =CH -), amino group (NH ₂ -), glycidoxy group

[Formula] and mercapto group (HS-), etc., and this compound is also called a so-called functional silane compound or a silane coupling agent, and is one selected from those represented by the following general formula or Two or more types can be used. General formula (R′) _3-o Si—(OR″) _o+1 [In the formula, R′ has the above-mentioned specific functional group, such as vinyl group, γ-aminopropyl group, γ-
(2-aminoethyl)aminopropyl group, γ-
Mercaptopropyl group, γ-glycidoxypropyl group, γ-methacryloxypropyl group,
R″ is an alkyl group having 1 to 8 carbon atoms, an alkyl alkoxy group, an allyl group, an aryl group, and an alkoxyl group thereof, n
is an integer of 1 to 2.] Examples of the alkoxysilane compounds represented by the general formula include divinyldiethoxysilane, divinyl-β-methoxyethoxysilane, di(γ-glycidpropyl)dimethoxysilane, and vinyltriethoxysilane. Silane, vinyltris-β-methoxyethoxysilane, γ-glycidoxypropyltrimethoxysilane, β(3,4epoxycyclohexyl)ethyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ
- Examples include mercaptopropyltrimethoxysilane. In the present invention, among the alkoxysilane compounds represented by the above general formula, those which can be particularly preferably used include γ-methacryloxypropyltrimethoxysilane, vinyltriethoxysilane, vinyltris(β-methoxyethoxy)silane, γ-
Glycidoxypropyltrimethoxysilane, γ-
Examples include aminopropyltrimethoxysilane. (2)-2 Vinyl monomer This is a monomer having at least one polymerizable unsaturated bond, which is reacted (copolymerized) with a compound having a vinyl group among the alkoxysilane compounds to form a silane. It is useful for producing synthetic resins. As the vinyl monomer, for example, those listed below can be used. Alkyl (1 to 22 carbon atoms) esters of acrylic acid: For example, methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, 2-ethylhexyl acrylate,
lauryl acrylate etc. Alkyl (1 to 22 carbon atoms) esters of methacrylic acid, such as methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, and the like. Hydroxyl group-containing vinyl monomers: for example, hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, etc. Carboxyl group-containing vinyl monomers: for example, acrylics, methacrylic acid, maleic anhydride, vinyl acetic acid, etc. Amino group-containing vinyl monomers: e.g. acrylamide, methacrylamide, acrylamine, N
- Isopropylacrylamide, N-n-butoxymethylacrylamide, etc. Glycidyl group-containing vinyl monomers: for example, glycidyl acrylate, glycidyl methacrylate, methylglycidyl acrylate, etc. Other vinyl monomers such as styrene, vinyltoluene, acrylonitrile, vinyl chloride,
Vinyl acetate, ethylene, propylene, vinyltoluene, divinyltoluene, vinylidene chloride, etc. In the present invention, one example of a method for producing a silanized resin is to polymerize only a vinyl group-containing alkoxysilane compound, but the purpose is to impart hardness, flexibility, crosslinkability, etc. to the silanized resin obtained thereby. It is preferable to copolymerize the various vinyl monomers described above. The proportion of vinyl monomer copolymerized is 30% by weight based on the total amount with the vinyl group-containing alkoxysilane compound.
Below, preferably 5 to 20% by weight is suitable. These polymerizations and copolymerizations are common solution polymerization,
It is carried out by emulsion polymerization, suspension polymerization, etc. The skeleton of the resulting resin (silanized resin) obtained by such polymerization or copolymerization reaction contains 2 atoms contained in the alkoxysilane compound having a vinyl group.
~3 alkoxysilane groups are bonded together. In addition, this polymer can be used as alkyd, epoxy,
Those modified with polybutadiene, polyurethane, phenolic resin, or amino resin can also be used. (2)-3 Organic resin This is a functional group that reacts with a specific functional group (for example, an amino group, a glycidoxy group, a mercapto group, etc.) that the alkoxysilane compound has, such as an epoxy group, a methylol group, -
One or more functional groups selected from NHCONHCH ₂ OH, carboxyl group, ester group, aldehyde group, carbonyl group, halogen element, amino group, hydroxyl group, unsaturated bond, isocyanate group, mercapto group, etc. as a side chain. and/or an organic resin in the main chain. Examples of organic resins having such functional groups include acrylic copolymers, alkoxy resins, epoxy resins, polybutadiene resins, monobasic acid (including fatty acids) or polybasic acid-modified polybutadiene,
Introducing methylolated phenolic resin, methylolated urea resin, methylolated melamine resin, polyurethane resin, vinyl chloride resin, vinylidene chloride resin, alkanolamine-modified polyurethane resin, polycarboxylic acid resin, aldehyde resin, unsaturated polyester resin, and unsaturated bond. acrylic resin,
Examples include alkyd resins, epoxy resins, polyvinyl acetals, synthetic drying oils, maleated oils, synthetic rubbers, mixtures of two or more of these, addition condensates, etc., and these can be water-solubilized (or water-dispersed). Water-soluble (or water-dispersible) resins can be used in the production of composite resins according to (A) above, and organic solvent-soluble resins can be used in the production of composite resins according to (B) above. Used in the production of body resin. Among the above-mentioned resins, those suitable for the present invention are resins that are soluble in organic solvents and contain hydroxyl groups in the molecule, and among them, acrylic copolymers, alkyd resins, epoxy resins,
Polyvinyl acetals are preferred. The above acrylic copolymer can be produced by a solution polymerization method, an emulsion polymerization method, a suspension polymerization method, etc. using the vinyl monomers exemplified in (2)-2 above, preferably in combination with a hydroxyl group-containing vinyl monomer. The acrylic copolymer is an acrylic copolymer synthesized by the above method, and may be an acrylic copolymer obtained by further modifying the copolymer with an alkyd resin, an epoxy resin, a polybutadiene, a polyurethane, a phenol resin, an amino resin, or the like. The blending ratio of the hydroxyl group-containing unsaturated vinyl monomer is
Although it can be changed arbitrarily depending on the amount of the alkoxysilane compound to be reacted with the resulting acrylic copolymer, it is usually required to be at least 5% by weight, and preferably within a range where no hydroxyl group remains in the final reaction product. Further, as the alkyd resin, a generally known alkyd resin obtained by reacting a polybasic acid and a polyhydric alcohol by a conventional synthesis method can be used. Examples include oil-modified alkyd resin, rosin-modified alkyd resin, phenolic resin-modified alkyd resin, styrenated alkyd resin, acrylic-modified alkyd resin, epoxy resin-modified alkyd resin, silicone resin-modified alkyd resin, oil-free alkyd resin (polyester resin), etc. . Examples of epoxy resins include conventionally known polyphenols, di- or polyglycidyl ethers of aliphatic polyhydric alcohols, dicarboxylic acid diglycidyl esters, epoxy compounds containing nitrogen-containing heterocycles, and water-soluble epoxies such as furfuryl glycidyl ether. Mention may be made of resins and conventional solvent-soluble epoxy resins. Preferred specific examples are polyglycidyl ethers of polyphenols having an average molecular weight of at least about 350, preferably about 350-3000 and an epoxy equivalent range of 150-3000, preferably 200-2000; Modified resins of epoxy resins, such as fatty acid-modified epoxy resins, polybasic acid-modified epoxy resins, acrylic resin-modified epoxy resins, alkyd resin-modified epoxy resins, polybutadiene resin-modified epoxy resins, phenolic resin-modified epoxy resins, amine- or polyamine-modified resins Epoxy resin, polyamide-urethane modified epoxy resin, etc. are used. In addition, polyvinyl acetals include polyvinyl formal, polyvinyl acetal, and polyvinyl butyral obtained by acetalizing a hydrolyzate of polyvinyl ester (polyvinyl acetate, polyvinyl propionate, etc.) with formaldehyde, acetaldehyde, butyraldehyde, etc. It is preferable to use a vinyl resin such as polyvinyl ester having a number average degree of polymerization of 250 to 1500. The degree of acetalization is preferably 55 to 88 mol%, and the hydroxyl group content is preferably 10 to 45 mol%. When producing a silanized resin made by reacting the above alkoxysilane compound and an organic resin to have an alkoxysilane group covalently bonded, for an alkoxysilane compound having an amino group (specific functional group), , for example, an epoxy group,
It is preferable to react an organic resin having a methylol group, -NHCONHCH ₂ OH, a carboxyl group, an aldehyde group, a carbonyl group, a halogen element, etc. Moreover, it is preferable to react an organic resin having, for example, an amino group, a hydroxyl group, a carboxyl group, etc. with the glycidoxy group-containing alkoxysilane compound. Further, it is preferable to react an alkoxysilane compound having a mercapto group with an organic resin having, for example, a polymerizable unsaturated bond, an isocyanate group, a mercapto group, or the like. Such a reaction is carried out as an addition or condensation reaction in the presence of an acid catalyst as described below. As described above, alkoxysilane compounds are bonded to themselves or to vinyl monomers or organic resins through polymerization reactions, addition reactions, condensation reactions, etc., and as a result, alkoxysilane groups are bonded together by covalent bonds. In this way, a silanized resin can be obtained in which the silanized resin is introduced into the resin skeleton. If desired, in order to water-solubilize or water-disperse these silanized resins, depending on the functional groups (hydroxyl group, carboxyl group, and amino group) introduced into the resin skeleton, in the case of acidic resins, an amine compound ( For example, aliphatic amines such as monoethylamine, alkanolamines such as diethanolamine, cyclic amines such as pyridine),
This can be achieved by neutralizing with aqueous ammonia or alkali metal hydroxide, or in the case of basic resins with fatty acids such as acetic acid or lactic acid or mineral acids such as phosphoric acid. Can be done. In the silanized resin used in the present invention, the composition ratio of the organic resin (including vinyl monomers other than the alkoxysilane compound) and the alkoxysilane compound is the weight percentage of the solid content, and the organic resin is
The content of the alkoxysilane compound is 70 to 99%, preferably 80 to 95%, and the content of the alkoxysilane compound is 30 to 1%, preferably 20 to 5%. If the content of the alkoxysilane compound is less than 1%, the crosslinking effect with the silica particles is insufficient. Further, even if it is added in an amount exceeding 30%, the crosslinking effect cannot be further increased. (3) Composite resin This is made by combining the above-mentioned silica powder and silanized resin at 10°C in the presence of water and an inorganic or organic acid.
The above can be obtained by reacting at a temperature range below the boiling point. The blending ratio of silica and silanized resin in the production of composite resin in the present invention is 5:95 to 75:25, preferably 20:80 to 60:40 in terms of solid content polymerization percentage. If the silica content is less than 5% by weight, the corrosion resistance of the formed film will decrease, and if the silica content exceeds 75%, the formed film will not have sufficient flexibility or continuous film properties, making it easy to crack and cause cohesive failure within the film. It is easy to obtain sufficient adhesion with the top coat. When producing the composite resin of the present invention, first, the alkoxy group in the alkoxysilane group of the silanized resin is hydrolyzed to form a silanol group (Si
-OH) is an essential condition. Such hydrolysis catalysts require water and an inorganic or organic acid. The effect of the proportion of water in the reaction system on the reaction rate is generally not particularly significant, but if it is not extremely small, for example 0.1
If the amount is less than % by weight, hydrolysis will be too slow and practical use will be poor. The inorganic acid or organic acid used as a hydrolysis catalyst is preferably a water-soluble acid having a dissociation constant value (PKa) of 7 or less. Specific examples include hydrochloric acid, sulfuric acid, nitric acid, chloric acid, phosphoric acid, orthophosphoric acid, formic acid, acetic acid, propionic acid, acrylic acid, lactic acid, oxalic acid, maleic acid, tartaric acid, citric acid, and gallic acid. . In addition, although the reaction is slow, basic catalysts (metal hydroxides, ammonia, amines)
can also be used. To produce a composite resin, first, depending on its form, the silanized resin is dissolved or dispersed in water or an organic solvent, and the solid content is 40% by weight or less, and the resulting mixture is charged into a reaction vessel, and the hydrolysis catalyst is added while stirring. Add the aqueous solution dropwise. Subsequently, a water-dispersed or organic solvent-dispersed silica component is added and thoroughly mixed. This mixed solution can be made into a composite resin by aging at room temperature, preferably at 10°C or higher; however, in order to obtain a strong film, the mixed solution should be aged at 50°C or higher at the boiling point (usually 105°C or higher). It is desirable to heat continuously at a temperature of about 110°C or lower, and specifically, by heating at a temperature of 50 to 90°C, sufficient bonding between the two components (silanized resin and silica) is achieved. As heating continues, the viscosity of the mixture gradually increases, but
Eventually, the temperature becomes almost constant and no change is observed, so at that point the heating can be stopped. It usually takes 0.5 to 5 hours to reach the end point. The surface treatment composition according to the present invention has the composite resin obtained as described above as a main component, but if necessary, it may further contain an amino resin and/or
Epoxy resin can be blended. This resin acts as a crosslinking agent and is crosslinked and cured by dehydration condensation reaction or addition reaction with the remaining functional groups in the composite resin, forming a stronger and denser film that has excellent water resistance, alkali resistance, and acid resistance. properties and solvent resistance. Examples of such amino resins include conventionally known urea-formaldehyde condensation products modified with monohydric alcohols such as methanol or butanol, monomeric and polymeric melamine resins, and benzoguanamine resins. In addition, the epoxy resin can be crosslinked through an addition reaction between the epoxy group in its molecule and the carboxyl group in the composite resin to form a stronger coating. Such epoxy resins have an average molecular weight of at least about 350, preferably about 350 to 3000, and an epoxy equivalent of 150 to 3000.
3000, preferably polyphenol glycidyl ethers in the range of 200 to 2000. The blending ratio of the above-mentioned amino resin and/or epoxy resin and composite resin is expressed as a weight percentage ratio.
The ratio is 40/60 to 5/95, preferably 30/70 to 10/90. If the amount of the amino resin and/or epoxy resin used exceeds the above range, it will be difficult to fully exhibit the inherent performance of the composite resin, and if it is less than the above range, the effect as a crosslinking agent will not be sufficient. In the present invention, in addition to the above-mentioned essential and desired components, the following substances may be used in combination as necessary to further improve curability.
It can provide anti-corrosion properties, film lubricity, electrical conductivity, etc. That is, chelate compounds of titanium, zirconium, aluminum, etc. as described in Japanese Patent Publication No. 55-41711, oxyacid salts and metal salts as described in Japanese Patent Publication No. 57-30867 and Japanese Patent Application Laid-open No. 55-62971, etc. By using these together, low temperature curing becomes possible. In addition, commonly known rust-preventing pigments (for example, zinc chromate, strontium chromate, calcium chromate, red lead, zinc oxide, lead cyanamide, calcium lead acid, basic lead sulfate, zinc phosphate, zinc molybdate, Improving corrosion resistance by adding potassium molybdate, barium metaborate, etc.) and rust inhibitors (phenolic carboxylic acids, organic phosphoric acids, phytic acid, urea derivatives, imidazole derivatives, nitrites, etc.) is possible. It is also possible to use molybdenum disulfide, polyethylene resin powder, fluororesin powder, etc. in combination to enhance the lubricity of the coating and improve the workability. Furthermore, a composition that forms an electrically conductive film can be prepared by mixing an electrically conductive substance, thereby imparting electrical weldability and electrophoretic coating properties. Examples of such conductive substances include zinc, aluminum, iron, cobalt, nickel, manganese, chromium, molybdenum, tungsten, copper,
Metal powders such as lead and tin and their alloy powders, conductive carbon, graphite powder, iron phosphide powder, aluminum-doped zinc oxide powder, tin oxide - titanium oxide, tin oxide - barium sulfate, nickel oxide -
Examples include semiconductor oxides such as alumina. Furthermore, a composition capable of forming a chromatic transparent film or a film having optical hiding properties can be prepared by dispersing chromatic pigments, extender pigments, dyes, etc. that are commonly used for decoration. When the resin acid value of the composite resin is 40 or more,
Alkaline components (e.g. ammonia, amines,
It is also possible to make it water-soluble or water-dispersible by neutralizing it with a metal hydroxide (metal hydroxide, etc.). Furthermore, if necessary, resins compatible with the composite resin among conventionally known organic solvent-based or water-based organic resins may be mixed and used in combination to improve various performances. The object to be coated with the composition of the present invention may be any ordinary metal (raw material or molded article), such as iron, aluminum, zinc, tin, copper, and alloys of these metals (alloys). Examples of metals include zinc, aluminum, chromium, silicon, cobalt, zirconium, tin, titanium, iron, lead, nickel, magnesium, manganese, molybdenum,
(composed of one or more types of phosphorus, etc.), multilayer metal plates (multilayers of two or more layers) of these metals, and general use for the purpose of providing metal rust prevention and coating base properties to these metals. Metals subjected to known metal surface treatments, such as iron phosphate, zinc phosphate, iron zinc phosphate, calcium phosphate, etc., chromic acid, chromium chromate, chromium phosphate,
Examples include surface-treated metals subjected to chromate treatment such as electrolytic chromate, anodization treatment, boehmite treatment, etc. The surface treatment composition obtained by the present invention forms a film that exhibits not only water resistance, moisture resistance, and alkali resistance, but also extremely corrosion resistance, especially when applied on a chromate-based surface treatment. do. When performing chromate-based surface treatment for the purpose of labor saving, rationalization, and low pollution, or for single-sided rust prevention treatment for automobile rust prevention steel plates, please refer to Japanese Patent Publication No. 45-38891. A waterless wash coating type chromate treatment as described in 2009 is suitable, and in the case of single-sided treatment, an electrolytic chromate method is also effective. The surface treatment composition according to the present invention contains one or more selected from the above-mentioned composite resins as a main component, and further contains an epoxy resin and/or an amino resin, a chelate compound, and an oxyacid salt as necessary. , metal salts, anti-rust pigments, anti-rust agents, resin powders,
Conductive substances, chromatic pigments, extender pigments, neutralizing agents, etc. can also be added. The surface treatment composition has a solid content concentration of 5
The surface treatment of the metal is carried out by preparing a solution of ~40% by weight, preferably 15~30% by weight, and coating the metal object by a conventionally known method. The coating thickness of the composition is not particularly limited, but it is usually preferably 1 to 30 microns based on the dry film thickness. As a coating method, for example, brush coating, spray coating, roll coating, electrodeposition coating, dip coating, etc. can be used, so it can be applied to a wide range of applications such as coil coating, complex shapes, outdoor structures, etc. The composition of the present invention may be cured by natural drying or heating at a temperature of room temperature to 300°C for about 2 seconds to 30 minutes, depending on the type and properties of the components constituting the organic resin used to produce the composite resin. It is carried out by. In addition, if an organic resin in which polymer unsaturated double bonds are introduced into the composite resin is used, it can be cured using an ordinary electron beam irradiation device (100 to 300 KeV, 30 ~100 mA) or an ultraviolet irradiation device (30 to 120 W/cm high pressure mercury lamp). The film of the surface treatment composition according to the present invention formed by coating in this manner has excellent properties in treating the base for painting. In other words, compared to conventionally known phosphate and chromate treated coatings, it has superior adhesion and corrosion resistance to the coating film applied to the treated coating surface.
Another major advantage is that it is non-polluting. Furthermore, compared to the surface treatment film using an organic colloidal silica composite proposed by the present inventor in the above-mentioned Japanese Patent Publication No. 53-5914, etc., the film according to the present invention has water resistance, alkali resistance, and a coating film painted on its surface. It has excellent adhesion and organic solvent resistance. The paint to be applied to the coating surface formed by surface treatment according to the present invention is not particularly limited, and any known solvent-based, water-based, non-solvent-based, powder-based paint, etc. can be applied, and it can be applied according to the purpose of coating. Therefore, both single-layer coating and multi-layer coating such as two or three layer coatings are possible. In addition, the painting method and baking of these paints are
All coating methods such as spray, dipping, roll, electrophoresis, and electrostatic coating are possible, and baking methods vary depending on the type of top coat, from room temperature curing to heat curing (possible up to approximately 350℃), infrared curing, ultraviolet curing, and electronic curing. Any method such as line curing is possible. Top coating systems include, for example, electrodeposition coating - intermediate coating - top coating system for automobiles, primer coating - top coat system for pre-coated metal, one-coat system for electrical appliances, steel products, etc., ships, etc. Heavy-duty anti-corrosion coating systems for bridges, pipes, etc., resin linings other than paint, resin laminate systems, etc. are also possible. In addition, since the composite resin contains a suitable amount of hydrophilic and hydrophobic groups in its molecules, it can be used not only for the metal materials mentioned above, but also for inorganic materials such as ceramics, concrete, asbestos, plastics, painted objects, wood, etc. It can be applied to paper, etc., and has a metal corrosion inhibiting function as a coating function of the composite.
High surface hardness provides wear and scratch resistance,
Heat resistance and flame retardant functions based on silica components, stain resistance functions based on silane compounds, etc. can be applied to the above-mentioned objects to be used for surface modification, decoration, etc. of the materials. Examples and comparative examples are shown below. These examples are intended to explain the invention in more detail and are not intended to limit the scope of the invention. Parts and percentages refer to parts and percentages by weight. 1 Example of synthesis of silanized resin 1 Synthesis of silanized-acrylic copolymer resin Equipped with thermometer, stirrer, cooler, and dropping funnel
Pour 100 parts of isopropyl alcohol into a 300ml four-neck flask, replace the air in the flask with nitrogen gas, adjust the temperature inside the flask to 85°C, and add 18 parts of styrene, 25 parts of methyl methacrylate, and 20 parts of n-butyl acrylate. parts, N-n-butoxymethylacrylamide 7 parts, 2-hydroxyethyl acrylate 10 parts, acrylic acid 10 parts, γ-methacryloxypropyltrimethoxysilane (Shin-Etsu Chemical Co., Ltd.)
A monomer mixture consisting of 10 parts of KBM 503 (manufactured by KBM Corporation, trade name: KBM503) and 3 parts of azobisisobutyronitrile was added dropwise from the dropping funnel over a period of about 2 hours. After the dropwise addition was completed, the temperature was kept at the same temperature for 1 hour, then 1 part of azobisdimethylvaleronitrile and 43 parts of isopropyl alcohol were added dropwise, and the reaction was continued at the same temperature for 4 hours, resulting in a polymerization rate of almost 100% and a solid content of approximately A colorless and transparent resin solution with a concentration of 41%, an acid value of about 64, and a hydroxyl value of about 45 was obtained. Examples 2 to 3 Synthesis of silanized-acrylic copolymer resin Synthesis of silanized-acrylic copolymer resin in the same manner as in Example 1 above based on the monomer formulations of Synthesis Examples 2 and 3 in Table 1 did. Example 4 Silanization - Synthesis of alkyd resin Put 100 parts of linseed oil, 70 parts of trimethylolpropane, and 0.07 parts of litharge into a flask, heat to 220°C in a nitrogen stream while stirring, and at this temperature.
After reacting for 30 minutes, it was cooled and when the temperature reached 70°C, 110 parts of phthalic anhydride and 13 parts of xylol were added.
Heat to 220°C with stirring, react under reflux of xylol, stop the reaction when the acid value drops to 15, and cool to 80°C, xylol 38
1 part, 32 parts of ethylene glycol monoethyl ether, solid content is approximately 70%, acid value is 15, hydroxyl value is approximately 48
An alkyd resin solution was obtained. Next, this alkyd resin solution was diluted with ethylene glycol monoethyl ether until the solid content was 40%, and 110 parts of this alkyd resin solution and γ-
Add 5 parts of glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., trade name "KBM403"), raise the temperature to 200°C in a nitrogen stream, and heat under reflux at this temperature for 2 hours to determine the solid content. A colorless and transparent resin solution of about 42% was obtained. Example 5 Silanization - Synthesis of epoxy resin 50 parts of bisphenol A type epoxy resin (manufactured by Ciel Chemical Co., Ltd., trade name, Epicoat 1004) having an epoxy equivalent of 950 is mixed with 25 parts of ethylene glycol monoethyl ether and butyl carbitol. Dissolve in 25 parts of a mixed solvent and add γ-aminopropyltrimethoxysilane (Shin-Etsu Chemical Co., Ltd.) to this solution while stirring.
(trade name: KB602). This mixture was heated to 200°C in a nitrogen stream, and at this temperature
After heating under reflux for an hour, ethylene glycol monoethyl ether was cooled down to 70°C.
A colorless and transparent resin solution with a solid content of about 40% was obtained. Example 6 Synthesis of acrylic copolymer resin Based on the monomer formulation of Synthesis Example 6 in Table 1, an acrylic copolymer resin solution was synthesized under the same reaction conditions as in Example 1 above. 2 Synthesis Example of Composite Resin Example of Synthesis of Composite Resin 1 108 parts of dimethylaminoethanol was mixed with 500 parts of the silanized acrylic copolymer resin solution obtained in Synthesis Example 1 of Silanized Resin, and water was added to sufficiently dissolve the mixture. By stirring, an aqueous acrylic copolymer resin dispersion having a solid content of 20% and a pH of about 10 was obtained. This aqueous dispersion
Charge 300 parts into a flask, and gradually add 20 g of a 40% orthophosphoric acid aqueous solution dropwise while thoroughly stirring under a nitrogen gas stream. Next, colloidal silica (manufactured by Nissan Chemical Industries, Ltd., trade name, "Snowdex")
200 parts of an aqueous dispersion of 20% solids of N. This mixture was heated to 85℃, and at the same temperature
React by holding under reflux for a period of time, solid content approximately 20%
A colorless and transparent water-dispersible composite resin liquid 1 was obtained. Synthesis Example 2 of Composite Resin 200 parts of the silanized acrylic copolymer resin solution obtained in Synthesis Example 1 of silanized resin was adjusted to 30% with ethylene glycol monoethyether, and 200 parts of the solution was charged into a flask and heated with nitrogen. While thoroughly stirring under a gas stream, 20 g of 40% orthophosphoric acid aqueous solution was gradually added dropwise. Subsequently, 200 parts of an isopropyl alcohol dispersion of organosilica sol (manufactured by Nippon Shokubai Kasei Co., Ltd.) with a solid content of 20% is gradually added dropwise. This mixture was heated to 85° C. and kept under reflux at the same temperature for 4 hours to react, thereby obtaining a colorless and transparent solvent-dispersible composite resin liquid 2 having a solid content of about 20%. Synthesis Examples 3 to 6 of Composite Resin In Synthesis Examples 1 and 2 of Composite Resin, the composition raw materials were used in the amounts and synthesis conditions listed in Table 2, and the other conditions were the same as in Synthesis Examples 1 and 2. The composite resin liquids 3 to 6 were synthesized. Synthesis Example 7 of Composite Resin Reactant 7 108 parts of dimethylaminoethanol was mixed with 500 parts of the acrylic copolymer resin solution obtained in Synthesis Example 6 of Silica Resin, and after adding water, the mixture was sufficiently stirred to form a solid. An aqueous acrylic copolymer resin dispersion with a pH of about 10 and a pH of about 10 was obtained. 300 parts of this aqueous dispersion was charged into a flask, and while stirring thoroughly at room temperature, 20% solid content of colloidal silica (manufactured by Nissan Chemical Industries, Ltd., trade name "Snowtex N") and 200 parts of an aqueous dispersion were added. was gradually added dropwise. After the dropwise addition was completed, 7 parts of γ-methacryloxypropyltrimethoxysilane (previously described) was added dropwise and mixed with stirring, then heated to 85°C and kept at the same temperature for 2 hours to react.
A milky white, water-dispersible composite reactant 7 was obtained. Synthesis Example of Composite Resin Reactant 8 The solid content of the acrylic copolymer resin solution obtained in Synthesis Example 6 was mixed with ethylene glycol monoethyl ether.
Pour 200 parts of the solution adjusted to 30% into a flask,
While thoroughly stirring under a nitrogen gas stream, add γ-methacryloxypropyltrimethoxysilane (described above) 7.
Drip a portion. Next, 40% orthophosphoric acid aqueous solution
Drop 20 parts. Furthermore, 200 parts of an isopropyl alcohol dispersion of organosilica sol (described above) with a solid content of 20% is added dropwise. This mixture was heated to 85° C. and reacted by keeping it at the same temperature under reflux for 4 hours to obtain a colorless and transparent solvent-dispersible composite resin reactant 8 having a solid content of about 20%. Example 1 Composite resin liquid 1 synthesized above was applied to an electrolytic galvanized steel sheet that had been degreased with a silicate-based alkaline cleaner (manufactured by Nippon CB Chemical Co., Ltd., trade name "CC561B") to a dry film thickness of 2 microns. The coating was applied and baked for 60 seconds in a hot air atmosphere where the steel plate temperature reached 180°C. Regarding this coated plate, salt spray test, salt spray-dry-wet cycle test,
A salt water immersion-drying-wetting cycle test and a coating film adhesion test were conducted, and as shown in Table 5, excellent performance was shown in both cases. Also,
Cationic electrodeposition paint (Kansai Paint Co., Ltd.) was applied to this coated plate.
manufactured by Electron 9210) with electrodeposition coating (voltage
DC200V 3 minutes, bath temperature 08~30℃, baking 175℃-
The above-mentioned salt spray test, cycle test, and paint film adhesion test were also performed on the coated plate (film thickness: 20 microns), which had been applied for 30 minutes, and all showed excellent performance as shown in Table 6. Example 2 In Example 1, methylated urea resin (Mitsui Toatsu Chemical Co., Ltd.) was added to 8 parts of the solid content of the composite resin liquid 1.
A coated plate was prepared and a performance test was carried out in exactly the same manner as in Example 1, except that the composition contained 2 parts of UFR65 (trade name: UFR65, manufactured by Co., Ltd.) as a solid content. The results are shown in Table-5 and Table-6. All showed excellent performance. Example 3 A chromate treatment agent (manufactured by Kansai Paint Co., Ltd., trade name "Cosmer 100", chromium chromate-based coating treatment agent) was applied to the electrogalvanized steel sheet used in Example 1 in an amount of 1 to 50 mg of chromium. A coated plate was prepared in the same manner as in Example ¹ above, using a chromate-treated metal plate that was coated so that the amount of chromate was applied to the coating and then baked for 30 seconds in an atmosphere where the metal temperature reached 150°C. When performance tests were conducted, all showed excellent performance. The results are shown in Table-5 and Table-6 below.
Shown below. Examples 4 to 18 Example 1 According to Examples 2 and 3, a composite resin, an amino resin, and an epoxy resin were blended as shown in Table 3, and a composition obtained was mixed with the coating shown in the same table. When a performance test was conducted on coated plates made by coating on coated objects, all showed excellent performance. The results are shown in Tables 5 and 6 below. In addition, Examples 6 and 12 were coated objects treated with zinc phosphate (Bonderite #3004, manufactured by Nippon Parkerizing Co., Ltd.) (chemical conversion treatment amount was 1 g/m ² ) and 10% chromic anhydride rinse treatment. Made of metal. Also, Example 9, Example 15, Example
The chromate treatment of No. 18 was carried out in accordance with Example 3. Examples 19-24 Molten zinc was prepared by degreasing a composition in which 2 parts of methylated melamine was added to 8 parts of the solid content of the composite resins 1 to 6 synthesized above using the cleaner described in Example 1. Apply the coating to a plated steel plate to a dry film thickness of 2 microns, and then heat the steel plate to 180℃.
reach ℃. Baking treatment was performed for 60 seconds in an atmosphere. An aminoalkyd paint (trade name "Amiratsuk", manufactured by Kansai Paint Co., Ltd.) is applied to this composite surface-treated board,
A coated plate with a total film thickness of 20 microns was prepared by heating at 120°C for 20 minutes. The corrosion resistance of this coated plate in a salt spray test showed significantly superior performance compared to the current zinc phosphate treated zinc steel plate. Table 7 shows the results.
It was shown to. Examples 25-30 The composite surface-treated plates prepared in Examples 19-24 were coated with an epoxy primer paint for pre-coated metal (product name: "KP Color 8470 Primer" manufactured by Kansai Paint Co., Ltd.) and heated at 210°C. Heated for 50 seconds to create a coated plate with a dry film thickness of 5 microns, and then
Polyester topcoat paint (product name: KP Color,
1470, Blue”, manufactured by Kansai Paint Co., Ltd.),
A coated plate with a total dry film thickness of 25 microns was prepared by heating at 220°C for 50 seconds. The corrosion resistance of this coated plate in a salt spray test was found to be significantly superior to that of current galvanized steel sheets treated with zinc phosphate and galvanized steel sheets treated with chromate. The results are shown in Table 8 below. Comparative Examples 1 to 3 Coated plates were prepared in the same manner as in Examples 1 to 3 except that the composite resin liquid 1 was replaced with that obtained in Synthesis Example 7 of the composite resin reactant. When compared with body resins, the composite resin of the present invention showed good results, especially in terms of corrosion resistance in a salt water immersion-dry-wet cycle test and coating film adhesion after a boiling water test in electrodeposition coating. . The results are shown in Table-5 and Table-6. Comparative Example 4 A coated plate was prepared in the same manner except that the composite resin liquid 3 in Example 5 was replaced with that obtained in Synthesis Example 8 of the composite resin reactant, and the performance was compared.
The results were similar to those of Comparative Examples 1 to 3. Display the results.
5. Shown in Table-6. Comparative Examples 5-7 Composite resins in Examples 2, 8, and 11 were replaced with silanized resins 1-3 obtained in silanized resin synthesis examples 1-3 to prepare compositions with amino resins or epoxy resins ( When a coated plate was similarly prepared and tested, it was found that the corrosion resistance was significantly inferior to that of the composite resin system. Results are shown in Table-5 and Table-6
Shown below. Comparative Examples 8 to 10 A composition was prepared by simply mixing the constituent materials of the composite resin in Examples 5, 14, and 17 at room temperature (no catalyst, no heating reaction), and a coated plate was prepared and tested in the same manner. Corrosion resistance was significantly inferior to that of body resin systems. The results are shown in Table-5 and Table-6. Example 5 corresponds to Comparative Example 10, Example 14 corresponds to Comparative Example 8, and Example 17 corresponds to Comparative Example 9, respectively. Comparative Examples 11 to 20 In Examples 19 to 30, 2 parts of methylated melamine (Cymel 303, mentioned above) was added to 8 parts of the solid content of the silanized resin, which is the base resin of these composite resins. When a coated plate was prepared and tested according to Examples 19 to 30, as shown in Tables 7 and 8, the top coat was significantly inferior in adhesion and corrosion resistance compared to the composite resin system. . Comparative Examples 11 and 16 use Silica Resin Synthesis Example 1, Comparative Examples 12 and 17 use Silica Resin Synthesis Example 2, Comparative Examples 13 and 18 use Silica Resin Synthesis Example 3, Comparative Examples 14 and 19 use Silica Resin Synthesis Example 4, and Comparative Example In Nos. 15 and 20, those of Silica Resin Synthesis Example 5 were used, respectively.

【table】

【table】

[Table] *4 Oscar manufactured by Nippon Shokubai Kasei Co., Ltd.
*5 Manufactured by Desk Co., Ltd. Aerosil 200

【table】

【table】

[Table] *8: Basic resin and additives are both solid content

【table】

【table】

【table】

【table】

[Table] *9 Using a sharp knife, make 11 orthogonal incisions on the coating surface at 1 mm intervals, reaching the base surface, and process to obtain 100 incisions. Thereafter, it was deformed by extrusion from the back side to a depth of 5 mm using an Erichsen extrusion tester. The center of the side part and the center of extrusion were made to coincide.
Next, a cellophane adhesive tape with a width of 20 mm is pressed tightly by hand onto the surface of the coating on the side marks, and then it is rapidly peeled off to determine the number of lines remaining without being removed. displayed. *10 According to JIS-Z-2371. A cross cut was made on the painted surface with a knife so as to reach the substrate, and the evaluation was based on the time it took for the peeling width of the single-sided paint film from that part to reach 2 mm. *11 A coated plate cross-cut in the same manner as *10 was subjected to a 5% NaCl, 35°C salt water spray test for 2 hours at -60°C.
One cycle consisted of 2 hours of drying and 4 hours of a wet test at 40°C and 100% RH, and the condition of the coated surface after 100 cycles and the peeling width of the cross-cut area were evaluated. Appearance of flat part/Peeling width of cross-cut part (mm) *12 *Coated plate cross-cut in the same manner as in 10, immersed in 5% NaCl in salt water at 40°C for 7.5 minutes - dried at 60°C
One cycle was a 15-minute moisture test at 40°C and 100% RH for 7.5 minutes, and the condition of the coated surface after 2000 cycles and the peeling width of the cross-cut area were evaluated. Appearance of flat part/Peeling width of cross cut part (mm) *13 According to JIS-Z-0228. Place the coated plate in a humidity test box at 50℃ and 100%RH.
After leaving it for 2000 hours, it was taken out and the condition of the painted surface was observed. *14 Welding current 8KA, pressure between electrodes 200Kg, electrode tip
JIS/CF type 4.5mmφ Welding was conducted under the conditions of energizing time of 10∞50/50Hz, and evaluation was performed based on the number of dots that ensured the tensile strength of the welded parts to be 400Kg or more. *15 The electrodeposited plate was immersed in 40°C warm water for 240 hours, then left at room temperature for 24 hours, and an adhesion test was conducted according to *9. *16 According to JIS-Z-2371, crosscuts were placed on the painted surface using a knife, and evaluation was made based on the condition of the painted surface and the peeling width of the crosscuts after a salt water spray test for a specified period of time. Appearance of flat part/Peeling width of cross cut part (mm).

Claims (1)

[Scope of Claims] 1. An organic resin containing a di- or tri(alkoxy or alkoxyalkoxy)silane group in the organic resin skeleton and silica particles are heated at a temperature of 50°C or above and below the boiling point in the presence of an inorganic or organic acid. A surface treatment composition characterized in that the main component is a composite resin reacted in a temperature range of . 2. The surface treatment composition according to claim 1, the main component of which is a composition obtained by adding an amino resin and/or an epoxy resin to the above composite resin. 3. An organic resin containing a di- or tri(alkoxy or alkoxyalkoxy)silane group in the organic resin skeleton and silica particles are reacted in the presence of an inorganic acid or an organic acid at a temperature range of 50°C or higher and lower than the boiling point. 1. A surface treatment method comprising applying a solution of a surface treatment composition containing a composite resin as a main component to the surface of an object to be coated. 4. Claim 3, wherein the surface treatment composition has as a main component a composition obtained by adding an amino resin and/or an epoxy resin to the above-mentioned composite resin.
The method described in section. 5. The method according to claim 3 or 4, wherein the object to be coated is selected from steel and steel alloys, aluminum and aluminum alloys, zinc and zinc alloys, and metals coated with these metals. . 6 Claims 3 to 5 in which the object to be coated is a surface-treated metal plate treated with phosphate or chromate.
The method described in any of the paragraphs. 7. Organic solvent-based,
The method according to claim 3, characterized in that one or more types of paint selected from water-based, solvent-free, and powder-based paints are applied.