JP2792231B2 - Composition for metal surface treatment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Object of the Invention "Industrial Application Field" The present invention relates to a composition for metal surface treatment,
More specifically, when applied to a galvanized or zinc-based alloy-plated steel sheet that has been subjected to chemical conversion treatment, it has good coating adhesion, scratch resistance, and rust resistance over a long period of time, and is also effective as a coating base. The present invention relates to a composition for surface treatment which forms a natural film, and can be widely used in various industrial fields using metals such as a machine industry, an electric equipment industry, and an automobile industry.

[Prior Art] Conventionally, a large number of treating agents and paints have been used for the purpose of protecting the surface of a galvanized steel sheet or a zinc alloy-plated steel sheet from various corrosive environments. Among them, phosphate treatment or chromate treatment is common. However, it alone has only a primary rust-preventing role, and has a problem that rust is generated in a short time and rust occurs during the storage period until the overcoat, even if the overcoat is assumed.

In recent years, steel sheets having a resin coating formed on a zinc-based plated steel sheet which has been subjected to a chemical conversion treatment such as a chromate treatment or a phosphate treatment have been proposed and put into practical use for the purpose of improving rust prevention. This steel sheet has scratch resistance, fingerprint resistance during handling, adhesion during molding, crack resistance, and coating, adhesion, and durability such as rust resistance and water resistance during top coating. Etc. are required.

"Problem to be Solved by the Invention" The present inventors have previously proposed a metal rust preventive composition containing an organosilicon compound having an aminoalkyl group and an alkoxysilyl group, an epoxy resin and a thermoplastic resin as main components ( JP-A-60-238372).

The composition, when applied to a steel sheet, has excellent rust prevention properties, but has improved rust prevention properties in the processed parts such as bending and drawing, and adhesion durability during topcoat coating. Sex is required.

(B) Configuration of the Invention “Means for Solving the Problems” The present inventors have satisfactorily studied to find a metal rust preventive composition that satisfies the above-mentioned requirements and exhibits excellent rust prevention properties.
A composition obtained by dispersing and mixing silica particles in a composition comprising an organosilicon compound having an aminoalkyl group and an alkoxysilyl group, an epoxy resin and a polyvinyl butyral resin, satisfies the above-mentioned demands, and has excellent rust-preventive properties and an overcoating in a processed part. The present inventors have found that the composition can be a metal rust preventive composition exhibiting paint adhesion, and completed the present invention.

That is, the present invention relates to a metal surface treatment composition comprising an organosilicon compound having an aminoalkyl group and an alkoxysilyl group, an epoxy resin, a polyvinyl butyral resin, and silica particles dispersible in an organic solvent.

 Hereinafter, the components of the present invention will be described in detail.

O Organosilicon compound The organosilicon compound used in the present invention has both an aminoalkyl group and an alkoxysilyl group, and those described in the above-mentioned publications are similarly used, and are widely used as silane coupling agents. It also includes known ones.

For example, specific compounds include aminoalkyltrialkoxy having one aminoalkyl group and three alkoxysilyl groups such as aminomethyltriethoxysilane, γ-aminopropyltriethoxysilane, and γ-aminoisobutyltrimethoxysilane. Silane; N- (β-aminoethyl) aminomethyltrimethoxysilane, N- (β
-Aminoethyl) aminomethyltriethoxysilane, N
An N- (aminoalkyl) aminoalkyl group such as-(β-aminoethyl) aminopropyltrimethoxysilane and 3
N- (β-aminoalkyl) aminoalkyl trialkoxysilane having two alkoxysilyl groups; one aminoalkyl group and two alkoxysilyl groups such as aminomethylmethyldiethoxysilane and γ-aminopropylmethyldiethoxysilane N- (β-aminoalkyl) having an N- (aminoalkyl) aminoalkyl group such as N- (β-aminoethyl) aminopropylmethyldimethoxysilane and two alkoxysilyl groups ) Aminoalkylalkyldialkoxysilanes and the like, and those having two or more alkoxysilyl groups are particularly effective for improving rust prevention and are preferred for the present invention.

○ Epoxy resin As the epoxy resin used in the present invention, those described in the above publication are similarly used, and in the present invention, an epoxy resin having two or more hydroxyl groups in one molecule is preferable, and Those based on the bisphenol A used are preferred.

Commercial products of bisphenol A type epoxy resin include:
For example, Epicoat 1001, 1004, 1007, 1009 (all manufactured by Yuka Shell Epoxy Co., Ltd.) and the like can be mentioned. Further, a brominated epoxy resin in which part of the hydrogen atoms of the benzene ring of the bisphenol A type epoxy resin is substituted with bromine, for example,
Epicoat 1045 and Epicoat YL903 (all manufactured by Yuka Shell Epoxy Co., Ltd.) and the like.

Commercially available epoxy resins other than the bisphenol A type epoxy resin include dimer acid glycidyl ester type epoxy resins such as Epicoat 871 (manufactured by Yuka Shell Epoxy) and phenoxy resins such as PKHH
(Manufactured by Union Carbide Corporation).

In the present invention, an epoxy resin having two or more hydroxyl groups in one molecule, particularly a bisphenol A type epoxy resin, is preferred because the aminoalkyl group of the organosilicon compound and the oxirane ring of the epoxy resin react very easily. When the number of hydroxyl groups is less than two, the reaction rate is slow and it takes a long time to form a coating film, whereas when it has two or more hydroxyl groups, the hydroxyl group of the epoxy resin is
Presumably, this is because it greatly contributes to the reaction with the organosilicon compound, because a tough coating film is formed in a short time.

○ Polyvinyl butyral resin The polyvinyl butyral resin in the composition of the present invention refers to a polyvinyl alcohol obtained by saponifying polyvinyl acetate butyralized with butyl aldehyde, and is generally a copolymer of vinyl butyral, vinyl acetate and vinyl alcohol. Polymers having various properties depending on the composition, the degree of polymerization, and the like have been obtained. For details on the production method and properties of polyvinyl butyral resin, see the Encyclopedia of po
lymer science & technology vol.14 p.208-239 (Joh
n Willy & Sons).

Commercially available polyvinyl butyral resins include, for example, Eslec BL1, Eslec BL2, Eslec BMS,
Examples include Esrec BLS and Esrec BX1 (all manufactured by Sekisui Chemical Co., Ltd.), which are used in the present invention.

Polyvinyl butyral resin in the composition of the present invention,
The type is not limited, and it is considered that the hydroxyl group contained in the resin reacts with the organosilicon compound to contribute to the formation of a tough coating film.

○ Silica particles The silica particles used in the present invention are not particularly limited as long as they can be dispersed in an organic solvent, when the composition of the present invention is applied to a metal surface, in general, as an organic solvent solution. Although it is not something, from the aspect of organic solvent dispersibility,
Silica particles having a particle diameter of 0.01 to 1 μm or particles of silicon and a composite metal oxide or a composite hydroxide of zirconia, titanium, aluminum, boron or the like containing 50 mol% or more of silicon as a constituent metal component are preferred.

As such finely divided silica, first of all, finely divided silica as a commercial product, that is, fumed silica,
And hydrophobic silica (hydrophobic silica) obtained by treating fumed silica with silane or polysiloxane, and the details thereof are described in Encyclopedia of Chemical Technology (Secand Edit).
ion) Vol.18 p.61-72. Specific commercial products include, for example, Aerosil 200, Aerosil 300,
Aerosil R972 and Aerosil R810 (all manufactured by Nippon Aerosil Co., Ltd.).

Secondly, using a metal alkoxide or a metal coordination compound as a raw material, hydrolysis using a basic catalyst, a polycondensation reaction,
Examples thereof include silica particles obtained by a so-called sol-gel method (hereinafter, referred to as composite silica), and are preferable silica particles in view of reactivity with a resin, rust prevention of a processed portion, and the like.

The method for producing the composite silica obtained by the sol-gel method preferred for the present invention will be described in detail below.

A solution of one or more alkoxysilane compounds is added in the presence of a basic catalyst in an amount of 0.5 to 20 mol, more preferably 0.75 mol, per mol of the alkoxy group of the alkoxysilane compound.
0 to 200 ° C, more preferably 20 to 150 ° C with ~ 10 mol of water
This is a method in which hydrolysis and polycondensation are carried out at a temperature of ° C.

At a reaction temperature of 0 ° C. or lower, the progress of the reaction is extremely slow and impractical, and at a temperature of 200 ° C. or higher, the reaction cannot be controlled.
There is a risk of gelling or particles becoming unsuitable in size and shape for the present invention.

The alkoxysilane compound used at this time is a compound represented by the following general formula (1) or a partial condensate thereof.

^{_{(CH 3) nSi (OR 1}} ) 4- n (1) ( wherein R ¹ is an alkyl group, an aryl group, an alkenyl group or a hydrogen atom, n is an integer from 0-1.) The general The alkyl group, aryl group and alkenyl group as the substituent R ¹ in the formula (1) include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group,
i-butyl group, s-butyl group, t-butyl group and the like; phenyl group, tolyl group, mesityl group and the like; vinyl group, 1-propenyl group, allyl group and i-propenyl group.

Specifically, tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetra-i-propoxysilane, tetra-n-butoxysilane, tetra-i-butoxysilane, tetra-t-butoxysilane,
Methyltrimethoxysilane, methyltriethoxysilane, methyltri-n-propoxysilane, methyltri-
Examples thereof include i-propoxysilane, methyltri-n-butoxysilane, and methyltri-t-butoxysilane.

These partial condensates are those obtained by dehydrating and condensing the above-mentioned alkoxysilane monomer compound to form oligomers such as dimers and trimers. It is shown.

That is, as long as it has a reaction mechanism of generating a silanol group and an alcohol by a hydrolysis reaction from an alkoxy group in the silane compound, it can be used as an alkoxysilane compound as a raw material of the composite silica which is one of the constituent components of the present invention. It is.

As the basic catalyst used in the reaction, ammonia,
Amines such as ethylamine, diethylamine, triethylamine, etc .; inorganic bases such as sodium hydroxide and potassium hydroxide; anion exchange resins; solid bases such as lead hydroxyapatite, hydrotalcite, bismuth trioxide, and bismuth (V) hydroxide containing etc. Can be used, but a low-boiling amine,
Ammonia is particularly preferred.

The solvent is not particularly limited as long as it is compatible with water and alkoxysilanes. Examples of such a solvent include alcohols such as methanol, ethanol, propanol and butanol, ketones such as acetone and methyl ethyl ketone, and glycol monoethers such as ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol butyl ether and propylene glycol ethyl ether. However, it is preferable to use one or a mixture of two or more solvents selected from the group consisting of ketones and glycol monoethers that show good dissolving power for the epoxy resin and the polyvinyl butyral resin that are components of the present invention. .

The concentration of the alkoxysilane at the time of carrying out the reaction is 0.01 to 0.5 mol / in terms of oxide, preferably 0.03 to 0.3 mol /.
It is. When the concentration is lower than 0.01 mol /, the particle generation becomes very slow, and when the concentration is higher than 0.5 mol /, gelation may occur.

When producing a composite oxide or a composite hydroxide with zirconia, titanium, aluminum, boron or the like, a metal alkoxide or a metal coordination compound of such a metal coexists or a silica particle is produced when an alkoxysilane compound is hydrolyzed. It is obtained by adding and reacting later. that time,
By appropriately selecting the addition method and reaction conditions, various forms of composite oxides or composite hydroxides can be obtained.

The metal alkoxide or metal coordination compound that can be used at this time is not particularly limited as long as it has a property of being hydrolyzed under basic conditions, but a metal alkoxide represented by the following general formula (2): (3) or (4)
The metal coordination compound represented by is particularly preferred.

M (OR ² ) _m (2) (where M represents an m-valent metal atom, R ² represents an alkyl group, an aryl group, an alkenyl group or a hydrogen atom, and m represents an integer of 2 to 4) The metal M in the general formula (2) is a divalent to tetravalent metal, and examples thereof include titanium, zirconium, aluminum, and boron.

Substituent R ² is an alkyl group, an aryl group, an alkenyl group, a methyl group, an ethyl group, n- propyl group, i
-Propyl group, n-butyl group, i-butyl group, s-butyl group, t-butyl group, etc .; phenyl group, tolyl group, mesityl group, etc .; vinyl group, 1-propenyl group, allyl group, i-propenyl group And so on.

(Where M represents an n-valent (n is an integer of 2 to 4) metal atom, R ³ represents an alkoxy group, R ⁴ and R ⁵ represent an alkyl group, an aryl group, or an alkoxy group. , X is 0
And y is an integer of 2 to 4 and x + y is an integer of n. (Where M represents an n-valent (n is an integer of 2 to 4) metal atom, R ⁶ represents an alkoxy group, R ⁷ represents an alkyl group, an aryl group or a hydrogen atom, and x represents 0 And x + y is an integer of n.) The metal M of the metal coordination compound represented by the above formulas (3) and (4) is a divalent to tetravalent metal such as titanium, zirconium, Aluminum, boron, and the like can be given.
The substituents R ³ and R ⁶ are alkoxy groups such as a methoxy group, an ethoxy group, an n-propoxy group, and an i-propoxy group.

R ⁴ and R ⁵ are a methyl group, an ethyl group, an n-propyl group, i
Alkyl groups such as -propyl group, n-butyl group, i-butyl group and s-butyl group; aryl groups such as phenyl group, tolyl group and mesityl group; methoxy group, ethoxy group, n-propoxy group and i-propoxy group An alkoxy group such as a group or a hydrogen atom.

R ⁷ is an alkyl group such as a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-butyl group, an s-butyl group; an aryl group such as a phenyl group, a tolyl group, and a mesityl group Or a hydrogen atom.

Specifically, tetramethoxytitanium, tetraethoxytitanium, tetra-n-propoxytitanium, tetra-i-propoxytitanium, tetra-n-butoxytitanium, tetra-i-butoxytitanium, tetra-t-butoxytitanium,
Diacetyl acetate titanium propylate, titanium tetrakis (acetylacetonate), tetraethoxy zirconium, tetra-i-propoxy zirconium,
Tetra-n-propoxy zirconium, tetra-n-butoxy zirconium, tetra-i-butoxy zirconium, tetra-t-butoxy zirconium, zirconium bis (acetylacetonate), zirconium tetrakis (acetylacetonate), triethoxyaluminum, tri- n-propoxyaluminum, tri-i-propoxyaluminum, tri-t-butoxyaluminum, diethyl acetate aluminum diisopropylate, aluminum tris (ethyl acetoacetate),
Triethyl borate, boric acid and the like.

○ Solvent The composition of the present invention is generally applied in the form of a solution, and excellent effects are exhibited by dissolving it in a solvent. Examples of the solvent used include aromatic solvents such as toluene, xylene, ethylbenzene, and mesitylene; monoketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, dibutyl ketone, cyclohexanone, and isophorone; acetylacetone, methyl acetoacetate, and ethyl acetoacetate. 1,3-diketone solvents and β-ketocarboxylic acid ester solvents such as methyl alcohol, ethyl alcohol, isopropyl alcohol, isobutyl alcohol, n-butyl alcohol, 3-methoxybutyl alcohol, 3-methyl-3-methoxybutyl alcohol Alcohol solvents such as ethylene glycol methyl ether, ethylene glycol ethyl ether,
Glycol monoether solvents such as ethylene glycol butyl ether, diethylene glycol ethyl ether, propylene glycol methyl ether, propylene glycol ethyl ether, and propylene glycol butyl ether; ethyl acetate, butyl acetate, ethylene glycol methyl ether acetate, propylene glycol methyl ether acetate, propylene glycol ethyl Ether acetate, adipic acid dimethyl ester, 2
And ester solvents such as ethyl ethoxypropionate. Among these solvents, a mixed solvent of two or more selected from ketones, aromatics and glycol ethers having good dissolving power is preferable, and more preferably, the boiling point at normal pressure is 100 ° C. or more and 200 ° C. or more. Solvents at a temperature of at least ℃ have an appropriate volatilization rate and are preferred in terms of drying properties.

-Additives The composition of the present invention can contain appropriate additives for various purposes. As such additives, those widely used in the art can be mentioned, and the following can be mentioned.

Black pigments such as carbon black, acetylene black, ram black, bone black and black iron oxide; white pigments such as titanium oxide, zinc white and lead white; rust preventive pigments such as zinc dichromate and strontium dichromate; Extenders such as calcium, talc, clay, kaolin, alumina, and silicic anhydride; metal powders such as zinc powder and aluminum powder; and pigments such as molybdenum disulfide, ethylene tetrafluoride powder, and vinylidene fluoride powder.

In addition, various additives such as a viscosity modifier, a disintegrant, a leveling agent, a siloxane bond condensation catalyst, an antioxidant, and an ultraviolet absorber may be added. Such additives can be blended at an appropriate stage during production.

-Compounding ratio The compounding ratio of the organosilicon compound (hereinafter, referred to as component A), the epoxy resin (hereinafter, referred to as component B), and the polyvinyl butyral resin (hereinafter, referred to as component C) of the composition of the present invention is C /
B is preferably 90/10 to 40/60 by weight, and more preferably 85/15 to 50/50. If the ratio is out of this range, the adhesiveness of the resin to the base material is reduced, the adhesiveness at the time of processing is poor, and further, the film-forming property at the time of coating on the object to be coated is reduced.
Also, the mixing ratio of the component A is A / (B + C) in terms of weight ratio.
5/95 to 70/30 is preferred, and 10/90 to 60/40 is more preferred. When A / (B + C) is less than 5/95, the resulting coating has a low crosslink density, becomes brittle, or has a low hardness. When A / (B + C) exceeds 70/30, the film-forming properties are reduced, and it is difficult to obtain a dense film.

The ratio of the silica particles is 1/10 by weight based on the total amount of the organosilicon compound, the epoxy resin, and the butyral resin.
It is preferably 0 to 200/100, more preferably 5/10
It is 0 to 150/100. If the ratio is out of this range, the effect of compounding the pigment cannot be obtained, and the strength of the coating film is significantly reduced.

The concentration of the non-volatile components is preferably from 3 to 90% by weight, more preferably from 10 to 60% by weight. If the ratio is out of this range, the viscosity of the liquid at the time of coating is not appropriate, resulting in a problem in the coated film after coating.

○ Adjustment method The preparation method of the composition of the present invention is not particularly limited, for example, after dissolving an epoxy resin and a polyvinyl butyral resin in a solvent, blending an organosilicon compound, at room temperature or under heating After stirring, a method of adding silica particles and mixing them uniformly is preferable in terms of storage stability of the liquid.

○ Applicable base material The composition of the present invention can be widely applied to metal base materials, and includes iron and iron alloys, aluminum and aluminum alloys, copper and copper alloys, zinc plating and zinc alloy plating, nickel plating, chromium It is awarded for various plated substrates such as plating, cadmium plating, etc., especially zinc plating, nickel zinc plating, iron zinc plating, tin It exhibits excellent rust-preventive performance on zinc or zinc alloy plating such as zinc plating, and on steel plates or steel materials on which the plating surface has been subjected to chromate treatment and phosphate treatment.

-Application method The composition of the present invention in a solution form can be easily applied to a metal substrate, and as an application method, a known coating method such as spray coating, dip coating, roll coating, or brush coating can be applied. By removing the solvent at room temperature or under heating conditions after coating, a uniform coating film is formed and the object of the present invention can be achieved.

Preferably 0.1 to 100 g / m ² as a film thickness, more preferably 0.3 to 30 g / m ^2, particularly preferred are 0.5 to 10 g / m ^2, even especially in a thickness of 10 g / m ² or less It is a great feature of the composition of the present invention that it can significantly impart rust resistance.

Further, the metal treated with the composition of the present invention can be used as it is, but it is also possible to overcoat with various paints such as solvent-based, water-based, solvent-free, and powder-based paints.
Spray coating, roll coating, dip coating, electrostatic coating, electrodeposition coating, etc. can be used as the coating method, and drying by methods such as normal temperature curing, hot air heating, high frequency heating, far infrared heating, ultraviolet irradiation, electron beam irradiation, etc. Is cured. Examples of such coating include undercoating / overcoating of pre-coated steel sheet which is frequently used in the fields of building materials and home appliances, topcoating used in the field of home appliances and the like, electrodeposition coating / intermediate coating / topcoating in the field of automobiles and the like, civil engineering・ Steel pipes / paintings used in construction.

"Function" The composition of the present invention is achieved by mixing and dispersing silica particles in a composition comprising an organosilicon compound, an epoxy resin and a polyvinyl butyral resin,
It exhibits excellent coating performance when applied to metals, especially galvanized steel sheets and galvanized steel sheets subjected to chromate treatment and phosphate treatment.

The reason why the composition of the present invention exhibits excellent coating film performance is not clear, but is presumed as follows.

During hydrolysis under basic conditions, active SiOH remains on the surface of the precipitated composite silica, and the reaction between the SiOH groups and the OH groups in the resin occurs, creating a highly complex component with the resin component and the silica component. To form a dense film after coating.

This is because the composite silica precipitated during hydrolysis under basic conditions has a uniform particle size, is uniformly dispersed, and forms a uniformly dispersed coating film after coating.

A highly reactive metal component other than Si reacts with an OH group in the resin, or reacts or chemically bonds with a base metal or a chemical conversion treatment component, thereby exhibiting strong adhesion.

The active OH group of the composite silica reacts with the resin component of the top coat to form a strong bond.

 Hereinafter, a specific example will be described.

Examples and Comparative Examples Synthesis Example of Composite Silica Composite Silica A 80 parts of tetraethoxysilane and 100 parts of isopropanol were charged into a reaction vessel equipped with a dropping funnel, a thermometer, and a stirrer, and heated to 70 ° C. 0.5 parts ethylamine, 1 pure water
A mixture of 5.3 parts and 40 parts of isopropanol was gradually added dropwise, and the mixture was allowed to react at 70 ° C. for 3 hours.
Thus, a cloudy liquid in which silica fine particles of m were precipitated was obtained. Furthermore, this cloudy liquid was concentrated under reduced pressure, and the heating residue was adjusted to 10%. This heating residue, take 1g of cloudy liquid in an aluminum cup,
It was heated at 150 ° C. for 20 minutes and determined as the residual ratio.

Composite Silica B 60 parts of tetramethoxysilane and 110 parts of propylene glycol monoethyl ether were charged into a reaction vessel equipped with a dropping funnel, a thermometer, and a stirrer, and heated to 40 ° C., followed by 0.5 parts of ethylamine and 9.2 parts of pure water. A mixture of 30 parts of propylene glycol monomethyl ether was gradually added dropwise, and the mixture was allowed to react at 40 ° C. for 3 hours to obtain a fine cloudy liquid in which silica fine particles having an average particle size of 0.02 μm were deposited. Furthermore, this cloudy liquid was concentrated under reduced pressure, and the heating residue was adjusted to 10%.

Composite Silica C In a reaction vessel equipped with a dropping funnel, a thermometer, and a stirrer, 60 parts of tetraethoxysilane, 16.8 parts of zirconium tetrakis (acetylacetonate), 130 parts of methyl ethyl ketone
After heating the mixture to 70 ° C, ethylamine 0.3
Parts, 10.0 parts of pure water, and a mixed solution of 20 parts of methyl ethyl ketone was gradually added dropwise and allowed to react at 70 ° C. for 4 hours to obtain an average particle diameter of 0.1 part.
A slightly cloudy liquid having a composite silica of 05 μm precipitated was obtained. Furthermore, this cloudy liquid was concentrated under reduced pressure, and the heating residue was adjusted to 10%.

Composite silica D Partial condensate of tetraethoxysilane (Tama Chemical Industry Co., Ltd.) is placed in a reaction vessel equipped with a dropping funnel, a thermometer, and a stirrer.
And 40 parts of propylene glycol monomethyl ether) and 100 parts of propylene glycol monomethyl ether. The mixture was heated to 70 ° C., and then mixed with 0.3 part of ethylamine, 10.0 parts of pure water, and 25.0 parts of propylene glycol monomethyl ether. The mixture was gradually dropped and reacted at 70 ° C. for 3 hours to obtain a cloudy liquid on which silica fine particles were precipitated. Tetra-i is added to the obtained liquid.
-Propoxy titanium 2.8 parts was gradually dropped into a solution diluted with 10 parts of propylene glycol monomethyl ether,
For 2 hours to obtain a cloudy liquid in which composite silica having an average particle diameter of 0.1 μm was deposited. Furthermore, this cloudy liquid was concentrated under reduced pressure, and the heating residue was adjusted to 10%.

Example 1 In a flask equipped with a stirrer, 60 parts of Epicoat 1004 (manufactured by Yuka Shell Epoxy), 20 parts of Eslec SL1 (manufactured by Sekisui Chemical Co., Ltd.), 200 parts of composite silica A, and 330 parts of propylene glycol monomethyl ether After stirring for 3 hours, 20 parts of γ-aminopropyltriethoxysilane (molecular weight: 221) was added, and 1 part of dibutyltin dilaurate was further added as a catalyst, followed by mixing and dissolving. Obtained.

 This composition was subjected to the following tests.

○ Preparation of test plate First, galvanized electrolytic chromate treated plate (70 × 150 ×
0.475 mmt) by applying this solution with a bar coater to a film thickness of 1 g / m2.
² and heat-treated (maximum reaching plate temperature 20 ° C. × 60 seconds) to obtain a test plate.

 The characteristic measurement test was performed as follows.

○ Corrosion resistance test After cross-cutting the test plate, salt water spray test (JI
SZ-2317) for 240 hours. Table 1 summarizes the results. As a comparison, an uncoated product was also tested, but after 240 hours, red rust had occurred. The evaluation criteria were as follows.

○: No rust △: White rust 2mm or less ×: White rust 2mm or more In addition, Eriksen was applied to the test plate as a corrosion resistance test after processing.
After extruding 7 mm (JIS-K-5400), a salt spray test (JIS-Z-2371) was performed for 240 hours. Table 1 summarizes the results. The evaluation criteria were as follows.

○: No rusting and rusting △: White rust less than 10% of processed area ×: White rust of 10% or more of processed area ○ Adhesion test Adhesion test: primary adhesion and secondary adhesion Was tested. The primary adhesion test is performed on the coating surface of each test plate at intervals of 1 mm.
Carrying out a piece of gobang, applying and peeling an adhesive tape to this gobang, and the secondary adhesion test,
After the coating, each test plate was immersed in warm water (pure water) at 40 ° C for 240 hours and then taken out.
This was performed by peeling. Furthermore, the top coat adhesion
Each test plate was coated with Amilac # 805 White (manufactured by Kansai Paint Co., Ltd.) in a thickness of 40 μm and then similarly tested for primary adhesion and secondary adhesion. These results are summarized in Table 1.

：: No peeling Δ: Peeling 10% or less ×: Peeling 10% or more Examples 2 to 6 Composite silicas A to D were prepared in the same manner as in Example 1,
To obtain a homogeneous solution. Using these compositions, a corrosion resistance test and an adhesion test were performed in the same manner as in Example 1, and the results are summarized in Table 1.

Example 7 Composite silica A was mixed in the same manner as in Example 1 at the ratio shown in Table 1 to obtain a uniform solution. Using this composition part, a corrosion resistance test and an adhesion test were performed in the same manner as in Example 1, and the results are summarized in Table 1.

Example 8 In the same manner as in Example 1, Aerosil 200 (Nippon Aerosil Co., Ltd.) was mixed at the ratio shown in Table 1 to obtain a uniform solution. Using this composition, a corrosion resistance test and an adhesion test were performed in the same manner as in Example 1, and the results are summarized in Table 1.

Comparative Example 1 The same method as in Example 1 was used, but without mixing the composite silica, to obtain a uniform solution. Using this composition, a corrosion resistance test and an adhesion test were performed in the same manner as in Example 1, and the results are summarized in Table 1.

Comparative Example 2 Aluminum oxide C (Nippon Aerosil Co., Ltd.) was mixed in the same manner as in Example 1 at the ratio shown in Table 1 to obtain a uniform solution. Using this composition, a corrosion resistance test and an adhesion test were performed in the same manner as in Example 1, and the results are summarized in Table 1.

(C) Effects of the Invention The present invention is applicable to a metal substrate, particularly a galvanized steel sheet, and has good workability and rust prevention of a worked portion even at an extremely thin film thickness of 5 g / m ² or less. The film is transparent, has a strong resistance to fingerprint marks and scratches during various handling, and has excellent adhesion as a coating base when coated on it. It contributes widely to various industries as rust prevention treatment.

Continuing from the front page (72) Inventor Kenichi Ishizaki 1-1, Funamicho, Minato-ku, Nagoya-shi, Aichi Prefecture Toagosei Chemical Industry Co., Ltd. Nagoya Research Institute (72) Inventor Hidetake Inoue 1 Funamicho, Minato-ku, Nagoya-shi, Aichi Address No. 1 Tosagosei Chemical Industry Co., Ltd. Nagoya Research Institute Toshiko Nakata (58) Field surveyed (Int. Cl. ⁶ , DB name) C09D 5/00, 5/08 C09D 129/00-129/14 C09D 163/00-163/10

Claims (1)

(57) [Claims] 1. A metal surface treatment composition comprising an organosilicon compound having an aminoalkyl group and an alkoxysilyl group, an epoxy resin, a polyvinyl butyral resin, and silica particles dispersible in an organic solvent.