JPS632310B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention provides a metal surface treatment composition obtained by adding an amino resin and/or an epoxy resin to a composite resin consisting of an organic polymer containing a functional group selected from hydroxyl, carboxyl, and amino groups and a reactive silane compound. and apply this thing to the metal surface,
The present invention relates to a method for surface treatment of metals, which comprises forming a film that provides a high degree of corrosion resistance, weldability, electrodeposition coating properties, and coating base properties. In recent years, in the metal painting field, with the aim of saving labor and reducing manufacturing costs in the painting process, the conventional painting method, the so-called post-coat method for painting molded objects, has been replaced by a coated metal sheet, a so-called pre-coat sheet, in which the metal sheet is pre-coated with coils. There has been a shift towards using . This pre-coated board method eliminates on-site degreasing, chemical conversion treatment, and painting processes, making it possible to significantly reduce costs. In addition, with the aim of prolonging the life of steel materials and reducing overall costs by thinning paint films, products such as galvanized steel sheets, alloy galvanized steel sheets, aluminium-plated steel sheets, and alloy aluminium-plated steel sheets, which have even better corrosion resistance, are rapidly becoming available. It is beginning to appear. Furthermore, the rust prevention properties of these metal plates are further improved by coating them. For example, a composite resin proposed by the present applicant in which an organic polymer and colloidal silica are chemically bonded exhibits an excellent rust-preventing effect (see, for example, Japanese Patent Publication No. 54-34406), whereas conventional organic resin Compared to conventional coatings, the corrosion resistance is 5 to 10 times higher in the salt spray acceleration test at the same coating thickness. Furthermore, as a method to further improve rust prevention, a multilayer steel plate has been proposed in which the above-mentioned plated steel plate is subjected to a known chromic acid treatment and the above-mentioned composite resin, which is an invention of the present applicant, is coated (for example, Showa 57-108292
(see publication). However, since the organic polymer-colloidal silica composite resin invented by the applicant has a water-soluble organic resin and water-dispersible colloidal silica as its main components, the film formed from this composition has no affinity for water. The water resistance, humidity resistance, and alkali resistance of the film are not sufficient, and in environments with high humidity or alkaline atmosphere, the formed film absorbs moisture or swells, resulting in peeling of the top coat and decreased adhesion. This may cause problems. For example, surface-treated steel sheets coated with the above-mentioned organic polymer-colloidal silica composite are known to exhibit excellent anticorrosion properties, such as for automobile exterior panels and home appliances as single-sided coated steel sheets. However, in order to apply a top coat to these surface-treated steel sheets, for example, when exposed to an alkaline atmosphere during degreasing using an alkaline cleaner to remove press oil during press working, or during cationic electrodeposition coating for automobiles, Since the above-mentioned composite film swells or softens and the treated film changes in quality, the adhesion of the subsequently applied top coat may be significantly impaired. In addition, in steel sheets treated with single-sided multilayer treatment of chromate base treatment and water-based composite resin for the purpose of high corrosion resistance, hexavalent chromium may be eluted from the chromate layer during alkali cleaner treatment and contaminate the alkali cleaner. When such a phenomenon occurs, the surface of the bare steel sheet on the untreated side is passivated by hexavalent chromium, so in many cases, the subsequent zinc phosphate chemical conversion treatment of the bare steel sheet cannot be performed in accordance with the specified conditions. If this cannot be achieved, non-uniformity of the chemical conversion coating will occur, causing problems in subsequent processes. Therefore, the present inventors conducted intensive research to develop a metal surface treatment composition made of a composite resin free from the above-mentioned drawbacks, especially a hydrophobic composite resin. A composition comprising a combination of a hydrophobic composite resin formed by reacting an organic polymer containing at least one functional group with a silane compound and an amino resin and/or an epoxy resin as a crosslinking agent is as described above. The inventors have now completed the present invention by discovering that this composition has no drawbacks and exhibits especially remarkable corrosion resistance when applied to a phosphate-treated or chromate-treated surface-treated metal plate. Thus, according to the present invention, (A) an organic polymer containing at least one functional group selected from a hydroxyl group, a carboxyl group, and an amino group and a di-, tri-, or tetraalkoxy (or alkoxyalkoxy) silane compound; Composite resin 60 made by reacting in the presence of an inorganic or organic acid at a temperature of 50°C or higher and lower than the boiling point.
~95% by weight and (B) 5 to 40% by weight of an amino resin and/or epoxy resin, and the blending ratio of the silane compound and the organic polymer in (A) is such that the silane compound is A metal surface treatment composition in which the silane compound is 20 to 60% by weight and the organic polymer is 80 to 40% by weight in terms of solid content, expressed as the silica amount converted to the weight of SiO ₂ . A solution of 5 to 60% by weight (solid content) of the composition is applied to the surface of the metal object to form a dry film thickness.
A metal surface treatment method is provided, which is characterized in that the metal surface is coated to a thickness of 2 μm or less. The organic polymer used to form the composite resin (A) in the present invention includes hydroxyl groups (meaning alcoholic hydroxyl groups and silicon-bonded hydroxyl groups, so-called silanol groups), carboxyl groups, and amino groups in the molecule. Organic polymers containing at least one functional group selected from the following and soluble in organic solvents are suitable. For example, acrylic copolymers, alkyd resins, epoxy resins, fatty acid or polybasic acid-modified polybutadiene resins,
Methylol group introduced phenolic resin, alkanolamine modified polyurethane resin, polyamine resin,
Amino resins, polycarboxylic acid resins, polyvinyl acetals, and mixtures of two or more of these resins,
Examples include addition condensates. Among the above-mentioned resins, those suitable for the present invention are resins containing hydroxyl groups in the molecule, and among them, acrylic copolymers,
Alkyd resins, epoxy resins and polyvinyl acetals are preferred. The above-mentioned acrylic copolymer is an acrylic copolymer synthesized by a solution polymerization method, an emulsion polymerization method, a suspension polymerization method, etc. using a common unsaturated ethylenic monomer, and is a suitable one. is synthesized from a monomer composition containing an unsaturated vinyl monomer having a hydroxyl group as an essential component. This can be an acrylic copolymer modified with an alkyd resin, an epoxy resin, a polybutadiene, a polyurethane, a phenolic resin or 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 silane compound and crosslinking agent used to react with the obtained acrylic copolymer, it usually requires at least 5% by weight,
In addition, it is preferable to adjust the amount so that no hydroxyl group remains in the reaction product of (A) and (B). Examples of such hydroxyl group-containing unsaturated vinyl monomers include 2-hydroxyethyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate. In addition to the above-mentioned essential monomers, an unsaturated vinyl monomer can be appropriately blended for the purpose of imparting hardness, flexibility, and crosslinkability to the resin. Such monomers include, for example, methyl acrylate,
Ethyl acrylate, n-butyl acrylate,
Acrylic esters such as isobutyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate; methacrylic esters such as methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, glycidyl methacrylate; and others Ethylene, propylene, butadiene, isoprene, chloroprene, styrene, α-
Examples include methylstyrene, dimethylstyrene, divinyltoluene, vinyl acetate, vinyl propionate, vinyl ether, vinyl chloride, vinylidene chloride, acrylic acid, methacrylic acid, and maleic acid. Further, as the alkyd resin used for the same purpose, generally known alkyd resins obtained by ordinary synthesis methods 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. . Furthermore, as the epoxy resin, fatty acid modified epoxy resin, polybasic acid modified epoxy resin, acrylic resin modified epoxy resin, alkyd resin (or polyester) modified epoxy resin, polybutadiene resin modified epoxy resin, phenol resin modified epoxy resin, amine or Polyamide-modified epoxy resin, urethane-modified epoxy resin, etc. are used. The epoxy resin before modification in the above-mentioned modified epoxy resin includes conventionally known organic solvent-soluble epoxy resins, preferably the same type as the epoxy resin used as the crosslinking agent described later. 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%. In the present invention, a di-, tri-, or tetraalkoxy (or alkoxyalkoxy) silane compound (hereinafter simply referred to as a "silane compound") that is reacted with the organic polymer.
is a compound in which 2 to 4 alkoxy groups in the molecule are bonded to silicon atoms, and specific examples thereof include those having the following structure. () General formula (R ₁ is an alkyl group having 1 to 8 carbon atoms which may contain an alkoxy group, or an Allyl or Aryl group, n represents an integer of 0 or 11 or less) Silicates or polyalkyl (or allyl) silicates; specifically, for example, methyl orthosilicate, ethyl orthosilicate, n-propylorthosilicate, n-butyl orthosilicate, n-octylorthosilicate, phenyl orthosilicate, benzyl orthosilicate and phenethyl orthosilicate, allyl orthosilicate, methalyl orthosilicate, and polysilicates produced by dehydration condensation of these orthosilicates are also used. () General formula (R ₃ ) _3-o −Si−(OR ₂ ) _o+1 [R ₂ is an alkyl group having 1 to 8 carbon atoms which may contain an alkoxy group or an allyl (Ally or Aryl) group] Representation: R ₃ is carbon number 1-8
Alkyl group, Allyl group, Aryl group, vinyl group,
γ-chloropropyl group, γ-aminopropyl group, γ-(2-aminoethyl)aminopropyl group, γ-mercaptopropyl group, γ-glycidoxypropyl group, β-(3,4-epoxycyclohexyl)ethyl group , γ-methacryloxypropyl group; n represents an integer of 1 to 2]; specifically, for example, divinyldiethoxysilane, divinyl-diethoxysilane, -(β-methoxyethoxy)silane, di(γ-glycidoxypropyl)dimethoxysilane, methyltriethoxysilane, vinyltriethoxysilane, vinyltris-β-methoxyethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ -methacryloxypropyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-
Examples include mercaptopropyltrimethoxysilane. That is, if the alkoxy group in the silane compound has a reaction mechanism in which a silanol group and alcohol are produced through a hydrolysis reaction under specific conditions, it can be used as the silane compound of the present invention. The blending ratio of the silane compound and the organic polymer resin in the present invention is as follows:
When the amount of Si is expressed as the amount of silica converted to the weight of SiO ₂ , the solid content weight percentage ratio of silane compound/organic polymer resin is 5/95 to 75/25, preferably 20/80.
~60/40. If the silica content is less than 5% by weight, the desired corrosion resistance cannot be obtained, and the silica content is 75%.
If it exceeds this range, the flexibility and continuous film properties of the film formed will be insufficient and cracks will easily occur, as well as cohesive failure within the film will likely occur, making it impossible to obtain sufficient adhesion of the top coat. When producing the composite resin (A) in the present invention, it is essential to first hydrolyze a silane compound to a silane compound containing a silanol group. Water and an inorganic or organic acid are required as such hydrolysis catalysts. The influence of the proportion of water in the reaction system on the reaction rate is generally not particularly significant, but if it is extremely small, for example, if it is less than 0.1% by weight, hydrolysis will be too slow and it will be impractical; If it is present in an amount exceeding 100%, the organic polymer resin or silane compound may precipitate and a uniform composite resin may not be obtained. 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. Specifically, hydrochloric acid, sulfuric acid, nitric acid, chloric acid, phosphoric acid, formic acid, acetic acid, propionic acid, acrylic acid, lactic acid, oxalic acid, maleic acid, tartaric acid,
Examples include citric acid and gallic acid.
Furthermore, basic catalysts (metal hydroxides, ammonia, amines) can also be used, although the reaction is slow. In the method for synthesizing the composite resin (A) according to the present invention, first, an organic polymer is dissolved in a solvent mainly consisting of an alcohol solvent, and the solid content is 40% by weight or less, and the mixture is charged into a reaction vessel, and a silane compound is added while stirring. Drip. After that, water and an acid catalyst (usually used as an aqueous acid catalyst solution) are added dropwise. This mixed solution can be made into composite resin (A) by aging at room temperature, preferably above 10°C, but in order to obtain a strong coating, the mixed solution should be aged at above 50°C, below the boiling point. It is desirable to heat continuously at a temperature of 50 to 90°C, and specifically, by heating at a temperature of 50 to 90°C, sufficient bonding between both components is achieved. As the heating continues, the viscosity of the liquid mixture gradually increases, but eventually it becomes almost constant and no change is observed, so at that point, it is sufficient to mark the end point and stop the heating. It usually takes 0.5 to 5 hours to reach the end point. Although the reaction mechanism of the composite resin (A) has not yet been fully elucidated, it is presumed that the reaction mechanism is roughly as follows. Alkoxysilane compound
When an organic resin-acid catalyst-water-solvent mixture is heated, the alkoxy group of the alkoxysilane compound is hydrolyzed in the presence of water and an acid catalyst in the first step to form an active silanol group (Si-OH).
is generated. The silanol group of this hydrolyzed silane compound immediately forms a covalent bond or a hydrogen bond based on dehydration condensation with a hydroxyl group, carboxyl group, amino group, etc. in the organic resin to form a complex. If the hydrolysis of the alkoxysilane compound does not proceed in the first step, when a composition using this compound is formed into a film, it will not become transparent but will form an opaque, soft and brittle film, and the top coat will have poor adhesion. is insufficient, and many pinholes appear in the top coat. For this reason, it can be assumed that the composite resin (A) according to the present invention undergoes composite formation due to the formation of the covalent bond or hydrogen bond. On the other hand, in advance, an alkoxysilane compound is acid-catalyzed.
In some cases, a method is used in which the silane compound is hydrolyzed in the presence of water and then mixed with an organic resin, but in such a system, self-condensation between the silanol groups of the hydrolyzed silane compound proceeds to form a siloxane bond. Therefore, there is a shortage of silanol groups that form covalent bonds or hydrogen bonds with organic resins, making it impossible to form a composite resin. A metal surface treatment composition using a composite resin obtained in such a system cannot obtain the excellent metal corrosion protection and paint surface treatment properties described in the present invention. As is clear from the above results, in the present invention, priority is given to the self-condensation of active silanol groups generated by hydrolysis of alkoxysilane compounds, and silanol groups are combined with functional groups (especially hydroxyl groups) in organic resins. It is characterized by the way it reacts. Furthermore, the reason why the composite resin of the present invention exhibits superior water resistance compared to the above water-based composite resin proposed by the present inventors is that the silica component in the water-based composite resin is a water-dispersible colloidal resin. are silica particles,
Comparing this with the organic silica produced by hydrolysis of the silane compound in the solvent-based composite resin of the present invention, it is expected that the absolute amount of water adsorbed on the surface of the silica component in the former is significantly larger. . Desorption of this adsorbed water requires a temperature of 150° C. or higher, and it is thought that sufficient dehydration cannot be achieved by low-temperature curing and short-time treatment in the surface treatment step, which is the gist of the present invention. On the other hand, the solvent-based composite resin of the present invention has almost no adsorbed water and is more hydrophobic than the water-based composite resin, so it has excellent water resistance and alkali resistance. In the present invention, the composite resin (A) is composed of a composite resin alone or a composition of a mixture of two or more composite resins, which contains an amino resin and/or an epoxy resin (B) as an essential component. It is blended. This resin (B) acts as a crosslinking agent by dehydration condensation reaction or addition reaction with the remaining functional groups in the composite resin (A), forming a stronger and denser film, and improving water resistance and alkali resistance. , acid resistance, and solvent resistance. Such amino resins include conventionally known urea-formaldehyde condensation products modified with methanol or butanol, respectively;
Monomeric and polymeric melamine resins,
Examples include benzoguanamine resin. Also,
The epoxy resin can form a stronger coating through an addition reaction between the epoxy group in the molecule and the carboxyl group in the composite reactant. 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 furfuryl glycidyl ether, which are usually soluble in solvents. Mold epoxy resin can be used. Preferred specific examples of the above-mentioned epoxy resins include those having an average molecular weight of at least about 350, preferably about 350 to 3000.
and epoxy equivalent 150-3000, preferably 200-2000
Polyglycidyl ethers of polyphenols in the range of, for example, epoxy resins manufactured by Schiel Kagaku Co., Ltd.: Epikote 828 (bisphenol A type, average molecular weight approximately 380, epoxy equivalent approximately 190) Epikote 1001 (bisphenol A type) ,
Average molecular weight approximately 900, epoxy equivalent approximately 475) Epikote1002 (Bisphenol A type, average molecular weight approximately 1300, epoxy equivalent approximately 650) Epikote1004 (Bisphenol A type, average molecular weight approximately 1400, epoxy equivalent approximately 950) Epikote1007 (Bisphenol A type , average molecular weight of about 2900, and epoxy equivalent of about 1900). The blending ratio of the above-mentioned amino resin and/or epoxy resin (B) and composite resin (A) 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, the inherent performance of the composite resin cannot be exhibited, 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 components, the following substances may be used in combination as necessary to further impart hardening properties, anticorrosion properties, film lubricity, and electrical conductivity. That is, chelate compounds of titanium, zirconium, aluminum, etc. as described in Japanese Patent Publication No. 55-41711;
By using together oxyacid salts, metal salts, etc. as described in JP-62971, low-temperature curing becomes possible. In addition, commonly known rust-preventing pigments (for example, zinc chromate, strontium chromate, calcium chromate, red lead, lead zincide, lead cyanamide, calcium lead acid, basic lead sulfate, zinc phosphate, zinc molybdate, The composition improves 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.). It is possible to do so. 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. In addition, the biggest problem with so-called pre-coated steel sheets coated with ordinary organic resins or inorganic oxides is that electric welding or electrophoretic painting during the forming process is not practical enough. A treated board prepared by adjusting the composition according to the invention to a dry film thickness of 2 μm or less exhibits electrical weldability and electrophoretic paintability equivalent to untreated boards, but it also has electrical conductivity by mixing a conductive substance with the composition. It can also be made into a composition that forms a film, and can provide better electric weldability and electrophoretic paintability. Such substances include, for example, zinc, aluminum, iron, cobalt,
Metal powders such as nickel, manganese, chromium, molybdenum, tungsten, copper, lead, tin and their alloy powders, conductive carbon, graphite powder, iron phosphide powder, aluminum doped zinc oxide powder, tin oxide-titanium oxide, Examples include semiconductor oxides such as tin oxide-barium sulfate and nickel oxide-alumina. Furthermore, a composition capable of forming a chromatic transparent film or a film having optical opacities 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,
It is also possible to make it water-solubilized or water-dispersed by neutralizing it with an alkali (ammonia, amine, metal hydroxide, etc.). Furthermore, if necessary, the properties of the film can be adjusted by mixing a resin compatible with the composite resin among conventionally known solvent-based organic resins. 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,
(consisting 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 phosphate treatments such as iron phosphate, zinc phosphate, iron zinc phosphate, calcium phosphate, 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 metal surface treatment composition obtained by the present invention forms a film that exhibits outstanding corrosion resistance as well as water resistance, humidity resistance, and alkali resistance, especially when applied to a surface that has been subjected to a chromate-based surface treatment. 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-applying type chromate treatment agent such as that described in 2009 is suitable, and in the case of single-sided treatment, an electrolytic chromate method is also effective. Further, the metal plate surface-treated with the treatment agent of the present invention exhibits excellent performance in treating the base for painting. That is, it is characterized in that it provides top coat adhesion and corrosion resistance that are equivalent to or better than conventionally known phosphate and chromate treatments, and is also non-polluting. The paint used as the top coat can be any known solvent-based, water-based, non-solvent, or powder-based paint, and depending on the purpose of use, it can be applied in a single layer or in multiple layers such as two or three layers. Both are possible. In addition, coating methods include spray, dipping, roll, electrophoresis, and electrostatic coating, and baking methods include room temperature curing, heat curing (possible up to approximately 350°C), infrared curing, and infrared curing, depending on the type of top coat.
Any method such as ultraviolet curing or electron beam curing is possible. Top coating systems include, for example, electrodeposition coating - intermediate coating - top coating system for automobiles; primer coating for pre-coated metals.
Top coat systems; one-coat systems for electrical appliances and steel products; heavy-duty anti-corrosion coating systems for ships, bridges, pipes, etc.; resin linings and resin laminate systems other than paints; etc. are possible. The metal surface treatment composition of the present invention comprising the composite (A) and the amino resin and/or epoxy resin (B) has a solid content of 5 to 60% by weight, preferably 15 to 30% by weight.
The solution is prepared and applied to a metal object by a conventionally known method to treat the surface of the metal. Although the coating film thickness in this case is not particularly limited, it is usually preferable that the dry film thickness is 1 to 30 microns. As the coating method, for example, brush coating, spray coating, roll 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. To cure the composition of the present invention, the composite resin
Depending on the type and properties of the monomers constituting the organic polymer used to produce (A), it may be cured by natural drying or heating at a temperature of room temperature to 300°C for 2 seconds to 30 minutes, for example. . In addition, if an organic polymer with unsaturated double bonds is used, it can be cured using an ordinary electron beam irradiation device (100 to 300 KeV, 30 to 100 mA) or ultraviolet light by using an electron beam or ultraviolet curing method. It can also be cured using an irradiation device (30-120W/cm high-pressure mercury lamp). The composition of the present invention has a suitable composition of hydrophilic groups and hydrophobic groups in the molecule of the composite resin (A), which is a constituent component of the composition. , inorganic materials such as asbestos, plastics, painted objects,
It can be applied to wood, paper, etc., and the coating function of this composite resin is to inhibit metal corrosion, have high surface hardness to provide wear resistance and scratch resistance, and is produced by hydrolysis of silica components. It can provide heat resistance and flame retardant functions based on the silica component, and stain resistance functions based on the silane compound, and can be used for surface modification and decoration of 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. Examples of synthesis of organic polymers 1 Synthesis of acrylic copolymer resin Add isopropyl alcohol to a four-necked flask equipped with a thermometer, stirrer, cooler, and dropping funnel.
After adding 180 parts of ethyl acrylate and purging with nitrogen, adjust the temperature inside the flask to approximately 85°C, and add 140 parts of ethyl acrylate,
68 parts of methyl methacrylate, 15 parts of styrene, N-
15 parts of n-butoxymethylacrylamide, 38 parts of 2-hydroxyethyl acrylate, 24 parts of acrylic acid
1.5 parts of the monomer mixture are added dropwise over a period of about 2 hours together with a catalyst of 6 parts of 2,2'-azobis(2,4-dimethylvaleronitrile). After the addition, the reaction was continued for another 5 hours at the same temperature to obtain a colorless and transparent resin solution with a polymerization rate of approximately 100%, a solid content of approximately 63%, an acid value of approximately 67, and a hydroxyl equivalent of approximately 300. Example 2 Synthesis of silanol group-containing acrylic copolymer resin In Example 1, the monomer composition was 33.6 parts of styrene,
55.0 parts of n-butyl acrylate, 10 parts of hydroxyethyl acrylate, 8.4 parts of acrylic acid, 10 parts of γ-methacryloxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., trade name "KBM503"),
Synthesized in the same manner as Example 1, solid content approximately 60%, acid value approximately
A colorless and transparent resin solution of 64 was obtained. Example 3 Synthesis of oil-modified 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 and 32 parts of ethylene glycol monoethyl ether, the solid content is approximately 70%, the acid value is 15, and the hydroxyl equivalent is approximately
1200 alkyd resin solution was obtained. Example 4 Synthesis of fatty acid-modified epoxy resin 62 parts of bisphenol A type epoxy resin (trade name: Epicote 1004, manufactured by Ciel Chemical Co., Ltd.) having an epoxy equivalent of 950, 19 parts of linseed oil, 19 parts of tung oil, and 3 parts of xylene are added to a flask. 40 parts of ethylene glycol monoethyl ether. with a solid content of approximately 70% and an acid value of approximately 54.
A fatty acid-modified epoxy resin solution having a hydroxyl equivalent of about 520 was obtained. Synthesis Example of Composite Resin 1 In a 500 ml four-necked flask equipped with a thermometer, stirrer, condenser, Dane Stark trap, and dropping funnel, the solid content of the acrylic copolymer resin obtained in Organic Polymer Synthesis Example 1 was 30%. Add 200g of % cellosolve solution,
After purging with nitrogen, add ethyl polysilicate (manufactured by Nippon Colcoat Chemical Co., Ltd., trade name: ethyl silicate 40, degree of polymerization: 4) through the dropping funnel while stirring thoroughly.
~6.Drop 100g of SiO ( ₂ minutes 40%). Then 40
% orthophosphoric acid aqueous solution was gradually added dropwise, and then the mixture was heated to 90° C. and reacted under reflux for 4 hours to obtain a colorless and transparent composite resin 1. Synthesis Examples 2 to 5 of Composite Resin Composite resins 2 to 5 were synthesized according to Composite Resin Synthesis Example 1 using the formulations and conditions shown in Table 1. Synthesis example of water-based composite resin (corresponding to Comparative Examples 1 to 3) Acrylic copolymer resin solution obtained in Synthesis Example 1 500
By mixing 108 parts of dimethylaminoethanol per part of the mixture, adding water and stirring thoroughly, an aqueous acrylic copolymer resin dispersion having a solid content of 20% and a pH of about 10 was obtained. 375 g of this aqueous dispersion was placed in a flask, and 125 g of "Snowtex-N" (manufactured by Nissan Chemical Industries, Ltd., aqueous colloidal silica dispersion, SiO ₂ content 20%, PH 9-10) was added while stirring thoroughly at room temperature. was added dropwise over a period of about 10 minutes. After the dropwise addition, 1.5 g of γ-methacryloxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., trade name "KBM503", 1.5 g) was added dropwise and mixed with stirring, then heated to 85°C, and heated to 85°C for 2 hours at the same temperature. The mixture was allowed to react for a certain period of time to obtain a milky white, water-dispersible composite resin.

【table】

[Table] *3 Manufactured by Shin-Etsu Chemical Co., Ltd.: Silane coupling agent Example 1 The composite synthesized above was applied to an electrogalvanized steel sheet that had been degreased with a silicate-based alkaline cleaner (manufactured by Nippon CB Chemical Co., Ltd., product name CC561B). Methylated melamine resin (manufactured by Mitsui Toatsu Chemical Co., Ltd., trade name Cymel 303) is added to 8 parts of the solid content of body resin 1.
A 20% solids solution containing 2 parts of solids was applied to give a dry film thickness of 2 microns, 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 -
A dry-wet cycle test, a salt water immersion-dry-wet cycle test, a wet test, and a coating film adhesion test were conducted, and all showed excellent performance as shown in Table 4. In addition, this coated plate was electrodeposited with a cationic electrodeposition paint (manufactured by Kansai Paint Co., Ltd., Elekron 9210) (voltage DC 200V, energization for 3 minutes, bath temperature 08-30℃, baking 175℃ - 30 minutes) to a film thickness of 20 microns. The coated plates were also subjected to the above salt spray test, cycle test, and paint film adhesion test, and as shown in Table 5, all showed excellent performance. Example 2 A chromate treatment agent (manufactured by Kansai Paint Co., Ltd., trade name Cosmer 100, chromium chromate-based coating treatment agent) was applied to the electrolytic galvanized steel sheet used in Example 1 in an amount of 1 to 50 mg/m of chromium. ² , and then baked for 30 seconds in an atmosphere where the metal temperature reaches 150°C, a coated plate was prepared in the same manner as in Example 1 above, and a performance test was conducted. All of them showed excellent performance.
The results are shown in Tables 4 and 5 below. Examples 3 to 10 Metal surface treatment compositions and coated plates shown in Table 2 were prepared according to Examples 1 and 2 and performance tests were conducted, and all showed excellent performance.
The results are shown in Tables 4 and 5 below. In addition, the surface treatment in Example 6 was a treated plate that was treated with zinc phosphate (Bonderite #3004, manufactured by Nippon Parkerizing Co., Ltd.) (chemical conversion treatment amount was 1 dl/m ² ) and rinsed with 10% chromic anhydride. Using. The chromate treatment in Examples 4, 8 and 10 was conducted in accordance with Example 2.

[Table] Examples 11 to 15 A 20% solution of a composition in which 4 parts of methylated melamine resin (Cymel 303) was added to 16 parts of resin solid content of each of the composite resins 1 to 5 synthesized above,
It was applied to a hot-dip galvanized steel plate that had been degreased with the cleaner described in Example 1 to a dry film thickness of 2 microns, and then baked for 60 seconds in an atmosphere where the steel plate temperature reached 180°C. This surface-treated board was coated with amino alkyd paint (product name ``Amiratsuk'').
Kansai Paint Co., Ltd.) was applied and heated at 120°C for 20 minutes to create a coated plate with a total film thickness of 20 microns. 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. The results are shown in Table 6 below. Examples 16-20 An epoxy primer paint for pre-coated metal (product name "KP Color 8470 Primer" manufactured by Kansai Paint Co., Ltd.) was applied to the composite surface-treated plates prepared in Examples 11-15, and the mixture was 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 7 below. Comparative Examples 1 to 3 Surfaces were prepared in the same manner as in Examples 1 and 2, except that a water-based composite resin (obtained in the above-mentioned synthesis example of water-based composite resin) was used instead of composite resin 1. A treatment composition (listed in Table 3) and a coated plate were prepared, and compared with the coated plate of the present invention, the corrosion resistance in a salt water immersion-drying-wetting cycle test and the coating film adhesion after a boiling water test in electrodeposition coating were evaluated. The method of the present invention showed good results in terms of performance. The results are shown in Table-4 and Table-5. Comparative Example 4 A composition consisting of an organic polymer resin, which is the base resin of composite resin 1, and a melamine resin was prepared (Table 3).
When a coated plate was prepared and tested in the same manner as in Example 1, it was found that the corrosion resistance was significantly inferior to that in Example 1. The results are shown in Table-4 and Table-5. Comparative Example 5 A composition was prepared by simply mixing the constituent materials of the composite resin in Example 3 (no catalyst, no heating reaction), and a coated plate was prepared and tested in the same manner.
Compared to Example 3, the corrosion resistance was significantly inferior. The results are shown in Table-4 and Table-5. Comparative Examples 6 to 8 Similarly to Comparative Example 5, a coating plate was prepared according to each example and a reliability test was conducted on a simple mixed composition of the constituent materials of the composite resin corresponding to the following Examples-Comparative Examples. As a result, all of them were inferior to the corresponding examples in terms of corrosion resistance and electrodeposition coating adhesion. The results are shown in Table-4 and Table-5. Example 5 → Comparative Example 6, Example 7 → Comparative Example 7, Example 9 → Comparative Example 8, Comparative Examples 9 to 18 In Examples 11 to 20, compositions were prepared by simply mixing the constituent materials of the composite resin ( When coated plates were prepared and tested according to Examples 11 to 20 (no catalyst, no heating reaction), as shown in Tables 6 and 7, the adhesion and corrosion resistance of the topcoat film were superior to the corresponding examples. compared,
It was significantly inferior.

【table】

[Table] *6 Base resin and additives are both solid weight

【table】

【table】

【table】

【table】

【table】

【table】

Claims (1)

[Claims] 1. (A) An organic polymer containing at least one functional group selected from hydroxyl group, carboxyl group, and amino group and a di-, tri-, or tetraalkoxy (or alkoxyalkoxy) silane compound 60-95% by weight of a composite resin reacted in the presence of an acid or organic acid at a temperature of 50°C or higher and lower than the boiling point, and (B) 5-95% of an amino resin and/or epoxy resin.
40% by weight, and the blending ratio of the silane compound and the organic polymer in (A) is expressed as the amount of silica obtained by converting the amount of Si in the silane compound to the weight of SiO ₂ and, in terms of solid content, the silane compound is 20 to 60% by weight, and the organic polymer is 80 to 40% by weight.
% by weight of the metal surface treatment composition. 2 (A) An organic polymer containing at least one functional group selected from a hydroxyl group, a carboxyl group, and an amino group and a di-, tri-, or tetraalkoxy (or alkoxyalkoxy) silane compound in the presence of an inorganic or organic acid. 60 to 95% by weight of composite resin made by reacting at a temperature of 50℃ or higher and lower than the boiling point.
and (B) amino resin and/or epoxy resin 5-40
% by weight, and the blending ratio of the silane compound and the organic polymer in (A) is expressed as the amount of silica obtained by converting the amount of Si in the silane compound to the weight of _SiO2 . A 5-60% by weight (solids) solution of a composition containing 20-60% by weight of the silane compound and 80-40% by weight of the organic polymer is applied to the surface of the metal coating with a dry film thickness of 2 μm. A method for surface treatment of metal, characterized by coating the surface within the specified range. 3. The method for surface treatment of metals according to claim 2, wherein the metal objects to be coated are steel and alloy steel, aluminum and aluminum alloys, zinc and zinc alloys, and metals made of multiple layers of these metals. 4. The metal surface treatment method according to claims 2 and 3, wherein the metal object is a surface-treated metal plate treated with phosphate or chromate.