JPH04202481A - Composition for treating metal surface - Google Patents

Abstract

PURPOSE:To obtain the title compsn. with excellent anticorrosive properties at a processed part and top coat adhesiveness by compounding each specified org. Si compd. and silica particles, an epoxy resin and a polyvinyl butyral resin. CONSTITUTION:The title compsn. comprises an org. Si compd. with an aminoalkyl group and an alkoxysilyl group (e.g. gamma-aminopropyltriethoxysilane), org. solvent-dispersible silica particles (e.g. silica particles obtd. by the hydrolysis and polycondensation of tetraethoxysilane), an epoxy resin (e.g. Epikote(R) 1004 manufactured by Yuka-Shell Epoxy Co., Ltd.) and a polyvinyl butyral resin (e.g. Eslec(R) SL1 manufactured by Sekisui Chem. Co., Ltd.).

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Object of the invention "Field of industrial application" The present invention relates to a composition for treating metal surfaces. This relates to a surface treatment composition that has good paint film adhesion, scratch resistance, and rust prevention properties over a long period of time when applied to galvanized steel sheets, etc., and forms a film that is also effective as a paint base. It can be widely used in various industrial fields that use metals, such as industry, electrical equipment industry, and automobile industry.

"Prior Art" Many treatment agents and paints have been used for the purpose of protecting the surface of galvanized steel sheets or zinc alloy-plated steel sheets from various corrosive environments. Among these, phosphate treatment or chromate treatment are common. However, when used alone, it only serves as a primary rust preventive, and there are problems such as rust forming in a short period of time, and even when topcoating is required, rusting occurs during the storage period until topcoating.

In recent years, steel sheets in which a resin film is formed on a zinc-plated steel sheet that has been subjected to chemical conversion treatments such as chromate treatment and phosphate treatment have been proposed and put into practical use for the purpose of improving rust prevention. Such steel sheets have durability such as scratch resistance during handling, fingerprint resistance, adhesion and crack resistance during molding, paintability and adhesion during top coating, rust prevention, and water resistance. etc. are requested.

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

The composition has excellent rust prevention properties when applied to steel plates, or has improved rust prevention properties in processed parts such as bending and drawing, and adhesion durability during topcoating. Sex is required.

(B) Structure of the Invention ``Means for Solving the Problems'' The present inventors have made extensive studies to find a composition for metal rust prevention that satisfies the above requirements and exhibits excellent rust prevention properties. A composition in which silica particles are dispersed and mixed into a composition consisting of an organosilicon compound having an aminoalkyl group and an alkoxysilyl group, an epoxy resin, and a polyvinyl butyral resin, or a composition that satisfies the above requirements and has excellent rust prevention properties for processed areas and as a top coat. The present invention was completed by discovering that the composition can be made into a metal rust-preventing composition that exhibits paint adhesion.

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

The constituent elements of the present invention will be explained in detail below.

○Organosilicon compound The organosilicon compound used in the present invention has both an aminoalkyl group and an alkoxysilyl group, and is used as described in the above-mentioned publication, and is also widely used as a silane coupling agent. It also includes what is known.

For example, specific compounds include aminemethyltriethoxysilane, γ-aminopropyltriethoxysilane,
Aminoalkyltrialkoxysilanes having one aminoalkyl group and three alkoxysilyl groups such as γ-aminoisobutyltrimethoxysilane: N-(β-aminoethyl)aminomethyltrimethoxysilane, N-(β-
aminoethyl)aminomethyltriethoxysilane, N-
N-(β-aminoalkyl)aminoalkyltrialkoxysilane having an N-(aminoalkyl)aminoalkyl group and three alkoxysilyl groups such as (β-aminoethyl)aminopropyltrimethynesilane; aminomethylmethyljethoxy silane, aminoalkylalkyldialkoxysilane having one aminoalkyl group and two alkoxysilyl groups such as γ-aminopropylmethyljethoxysilane; N such as N-(β-aminoethyl)aminopropylmethyldimethoxysilane -(Aminoalkyl)N-(β-aminoalkyl)aminoalkylalkyldialkoxysilane having an aminoalkyl group and two alkoxysilyl groups, etc., and those having two or more alkoxysilyl groups or those with rust prevention properties It is particularly effective in improving the temperature and is preferable for the present invention.

○Epoxy resin As the epoxy resin used in the present invention, those described in the above-mentioned publication are similarly used, and in the present invention,
Epoxy resins having two or more hydroxyl groups in one molecule are preferred, and epoxy resins based on bisphenol A, which is commonly used, are particularly preferred.

Commercially available Hisphenol A epoxy resins include Epicort 1001, 1004.1007.10.
09 (all manufactured by Yuka Shell Epoxy ■), etc. Further, brominated epoxy resins in which some of the hydrogen atoms of the Hensen ring of hisphenol A type epoxy resin are substituted with bromine, such as Epicote 1045 and Epicote YL90.
3 (all made by Yuka Shell Epoxy ■), etc.

Commercially available epoxy resins other than hisphenol A type epoxy resins include dimer acid glycidyl ester type epoxy resins, such as Epicoat 871 (manufactured by Yuka Shell Epoxy ■), phenoxy resins, such as PKHH
(manufactured by Union Carbide Corporation), etc.

In the present invention, epoxy resins having two or more hydroxyl groups in one molecule, especially hisphenol A type epoxy resins, are preferred because the aminoalkyl group of the organosilicon compound and the oxirane ring of the epoxy resin react very easily, and one molecule of epoxy resins is preferred. If the number of hydroxyl groups in the epoxy resin is less than 2, the reaction rate is slow and it takes a long time to form a coating. It is thought that this is because it greatly contributes to the reaction, or because it forms a tough coating film in a short period of time.

○Polyvinyl butyral resin The polyvinyl butyral resin in the composition of the present invention is
Polyvinyl alcohol obtained by saponifying polyvinyl acetate is converted to butyral with butyraldehyde, and is generally a copolymer of vinyl butyral, vinyl acetate, and vinyl alcohol, with various physical properties depending on its composition, degree of polymerization, etc. is obtained. For the manufacturing method and properties of polyvinyl butyral resin, please refer to Encyclopedi.
a of poly-mer 5science &
technology vol, 14 p, 2
08-239 (John Witty & 5ons).

Commercially available polyvinyl butyral resins include, for example,
Examples include S-LEC BLI, S-LEC BL2, and Varnish BXI (manufactured by Tanemizu Chemical Industry Co., Ltd.), which are used in the present invention.

The polyvinyl butyral resin in the composition of the present invention is not limited in its type, but it is thought that the hydroxyl groups contained in the resin react with the organosilicon compound, contributing to the formation of a tough coating film.

O Silica particles When applying the composition of the present invention to a metal surface, the silica particles used in the present invention are particularly limited as long as they can be dispersed in an organic solvent because they are used as an organic solvent solution for boat fishing. However, from the viewpoint of organic solvent dispersibility, silica particles with a particle size of 0.01 to 1 μm or a composite of silicon containing 50 mol% or more of silicon as a constituent metal component, such as zirconia, titanium, aluminum, boron, etc. Particles of metal oxides or composite hydroxides are preferred.

As such fine powder silica, first of all, commercially available fine particulate silicic anhydride, that is, fumed silica, and hydrophobic silica (hydrophobic silica), which is obtained by treating fumed silica with silane or polysiloxane. I can name something called Encyc 1oped 1aof Chemical for details.
Technology(Second Edition)
n) Vol. 18p, 61-72. As a specific commercial product, for example, Aerosil 200
, Aerosil 300, Aerosil R972, Aerosil R810 (manufactured by Nippon Aerosil ■), and the like.

The second type includes silica particles (hereinafter referred to as composite silica) obtained from metal alkoxides or metal coordination compounds as raw materials by hydrolysis using a basic catalyst, polycondensation reaction, or the so-called sol-gel method. Silica particles are preferable from the viewpoints of reactivity, rust prevention properties of processed parts, etc.

A detailed explanation of the method for producing composite silica obtained by the sol-gel method preferred for the present invention is as follows.

A solution of one or more alkoxysilane compounds in the presence of a basic catalyst is 0.5 to 20 mol, more preferably 0.5 to 20 mol per mol of the alkoxy group of the alkoxysilane compound.
．． This method involves carrying out a hydrolysis and polycondensation reaction using 75 to 10 moles of water at a temperature of 0 to 200°C, preferably 20 to 150°C.

If the reaction temperature is below 0°C, the reaction progresses very slowly and is impractical, and if it is above 200°C, the reaction cannot be controlled, resulting in gelation or particles having a size or shape inappropriate for the present invention. There is a risk of becoming

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

(C H3)nS l(OR')4-n (
1) (However, in the formula, R1 represents an alkyl group, an aryl group, an alkenyl group, or a hydrogen atom, and n is an integer of 0 to l.) The alkyl group, aryl, which is the substituent R1 in the above general formula (1) Groups and alkenyl groups include methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i
-butyl group, S-butyl group, t-butyl group ring; phenyl group, tolyl group, mesityl group, etc.: vinyl group, l-propenyl group, allyl group, i-propenyl group, etc.

Specifically, tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetra-1-propoxysilane, tetra-n-butoxysilane, tetra-
1-butoxysilane, tetra-t-butoxysilane, methyltrimethoxysilane, methyltriethoxysilane,
Methyl tri-n-propoxysilane, methyl tri-n-propoxysilane, methyl tri-n-butoxysilane,
Examples include methyl tri-t-butoxysilane.

Furthermore, these partial condensates are those obtained by dehydration condensation of the above-mentioned alkoxylan monomer compounds to form oligomers such as dimers and trimers; examples include the following formulas: This is shown in .

Any alkoxysilane compound that has a reaction mechanism that produces silanol groups and alcohol through a hydrolysis reaction can be used as an alkoxysilane compound that is a raw material for composite silica, which is one of the constituent components of the present invention.

Basic catalysts used in the reaction include ammonia, amines such as ethylamine, diethylamine, and triethylamine, inorganic bases such as sodium hydroxide and potassium hydroxide, anion exchange resins, lead hydroxyapatite, hydrotalcite, and bismuth trioxide. , hydrated bismuth oxide (
Solid bases such as V) can be used; low-boiling amines and ammonia are particularly preferred.

Further, the solvent is not particularly limited as long as it is compatible with water and alkoxysilanes. Examples of such solvents include alcohols such as methanol, ethanol, propatool, 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. Use one or more mixed solvents selected from ketones and glycol monoethers that have good dissolving power for the epoxy resin and polyhinyl butyral resin that are the constituent elements of the present invention. That's preferable.

The concentration of alkoxysilane during the reaction is 0.01 to 0.5'''/l, preferably 0.5'''/l in terms of oxide.
03~0.3″″01/l. o,ot”.l/l
At lower concentrations particle formation is very slow, with 0.5
'''”/I! Higher concentrations may cause gelation.

When producing composite oxides or composite hydroxides with zirconia, titanium, aluminum, boron, etc., metal alkoxides of such metals or metal coordination compounds coexist or silica particles are used when hydrolyzing alkoxysilane compounds. It is obtained by carrying out an addition reaction after production. that time,
Various forms of composite oxides or composite hydroxides can be obtained by appropriately selecting the addition method and reaction conditions.

The metal alkoxide or metal coordination compound that can be used at this time is not particularly limited as long as it has the property of being hydrolyzed under basic conditions;
Metal alkoxides represented by 2) and metal coordination compounds represented by (3) or (4) are particularly preferred.

M(OR2). (2) (However, in the formula, M represents an m-valent metal atom, and R2 represents an alkyl group, an aryl group, an alkenyl group, or a hydrogen atom.
represents an integer of 2 to 4) The metal M in the above general formula (2) is a divalent to tetravalent metal, and examples thereof include titanium, zirconium, aluminum, and boron.

Examples of the alkyl group, aryl group, and alkenyl group that are substituents R2 include methyl group, 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 ring; vinyl group, 1-propenyl group, a1.・Le group,
i-propenyl group, etc.

11-(Hereinafter, blank)-11 (However, in the formula, M represents an n-valent metal atom (n is an integer of 2 to 4), R3 represents an alkoxy group, R4 and R5
represents an alkyl group, an aryl group, or an alkoxy group,
X is an integer of 0 to 2, y is an integer of 2 to 4, and x+y is an integer of n) (However, in the formula, M is an n-valence (n is 2 to 4)
R6 represents an alkoxy group, R7 represents an alkyl group, an aryl group, or a hydrogen atom, X represents an integer of O to 3, and x+y represents an integer of n. ) The metal M of the metal coordination compounds represented by formulas (3) and (4) above is a di- to tetravalent metal, such as titanium, zirconium, aluminum, boron, etc. Moreover, substituents R3 and R6 are methoxy group, ethoxy group, n-
It is an alkoxy group such as a propoxy group or an i-propoxy group.

R4 and R5 are methyl group, ethyl group, n-propyl group,
Alkyl groups such as i-propyl group, n-butyl group, 1-butyl group, S-butyl group; Aryl groups such as phenyl group, tolyl group, mesityl group: methoxy group, ethoxy group, n-propoxy group, i- It is an alkoxy group such as a propoxy group or a hydrogen atom.

R7 is an alkyl group such as a methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, S-butyl group; an aryl group such as a phenyl group, tolyl group, mesityl group; Or a hydrogen atom.

Specifically, tetramethoxytitanium, tetraethoxytitanium, tetra-n-propoxytitanium, tetra-1-propoxytitanium, tetra-n-butoxytitanium, tetra-
1-butoxytitanium, tetra-t-butoxytitanium, diacetylacetate titanium propylate, titanium tetrakis (acetylacetonate), tetraethquin zirconium, tetra-1-propoxyzirconium, tetra-n-propoxyzirconium, tetra-n-butoxy Zirconium, tetra-1-butoxyzirconium, tetra-t-butoxyzirconium, zirconium bis(acetylacetonate), zirconium tetrakis(acetylacetonate), triethoxyaluminum, tri-n-propoxyaluminum, trimy propoxyaluminum, tri-t- Examples include butoxyaluminum, aluminum diethyl acetate diisopropylate, aluminum tris(ethylacetoacetate), triethyl borate, and boric acid.

○Solvent The composition of the present invention is generally applied in the form of a solution.
Excellent effects can be achieved by dissolving it in a solvent. Examples of the solvent used include toluene,
Aromatic solvents such as xylene, ethylbenzene, mesitylene, etc., monoketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, dibutyl ketone, cyclohexanone, isophorone, etc. 1,3-diketone solvents such as niacetylacetone, methyl acetoacetate, ethyl acetoacetate, etc. and β-ketocarphonic acid ester solvents; alcohol solvents such as methyl alcohol, ethyl alcohol, isopropyl alcohol, isobutyl alcohol, n-butyl alcohol, 3-methoxybutyl alcohol, and 3-methyl-3-methoxybutyl alcohol; ethylene glycol; Glycol monoether solvents such as methyl ether, ethylene glycol ethyl ether, ethylene glycol butyl ether, diethylene glycol ethyl ether, propylene glycol methyl ether, propylene glycol ethyl ether, 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-
Examples include ester solvents such as ethyl ethoxypropionate. Among these solvents, a mixed solvent of two or more selected from ketone, aromatic, and glycol ether systems having good dissolving power is preferable, and more preferably one having a boiling point of 100°C or higher at normal pressure. Solvents at temperatures below 220°C have an appropriate volatilization rate and are preferred in terms of drying properties.

Additives Suitable additives can be added to the composition of the present invention for various purposes. Examples of such additives include those widely used in the field, including the following.

Black pigments such as carbon black, acetylene black, lamb black, bone black, and black iron oxide; White pigments such as titanium oxide, zinc white, and lead white.

Antirust pigments such as zinc dichromate and strontium dichromate; extender pigments such as calcium carbonate, talc, clay, kaolin, alumina, and silicic anhydride; metal powders such as zinc powder and aluminum powder; and molybdenum disulfide. , tetrafluoroethylene powder, vinylidene fluoride powder, and other pigments.

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

○Blending ratio Organosilicon compound of the composition of the present invention (hereinafter referred to as component A)
The blending ratio of , epoxy resin (hereinafter referred to as component B), and polyvinyl butyral resin (hereinafter referred to as component C) is C/B.
is preferably 90/10 to 40/60 in weight ratio, 85/
15 to 50150 or more preferably. If this ratio is exceeded, the adhesion of the resin to the base material will be reduced, the adhesion during processing will be poor, and furthermore, the film-forming property will be reduced when coating the object to be coated. In addition, the blending ratio of component A is A/
(B10C), the weight ratio is preferably 5/95 to 70/30, and more preferably 10/90 to 60/40. A/ (
When B+C) is less than 5/95, the resulting film has a low crosslinking density, becomes brittle, and has low hardness. Further, when the A/(B+C) ratio exceeds 0/30, the film forming property deteriorates and it is difficult to obtain a dense film.

In addition, the proportion of silica particles is 1/1 by weight with respect to the total amount of organosilicon compound, epoxy resin, and butyral resin.
It is preferably from 00 to 200/100, more preferably from 5/100 to 150/100. If the ratio is outside this range, the effect of blending the pigment may not be obtained or the strength of the coating film will be significantly reduced, which is not preferable.

Moreover, the concentration of nonvolatile matter is preferably 3 to 90% by weight, more preferably 10 to 60% by weight.

If this ratio is exceeded, the liquid viscosity during coating will not be appropriate, resulting in defects in the coating film after coating.

○ Preparation method The method for preparing the composition of the present invention is not particularly limited. For example, after dissolving the epoxy resin and polyvinyl butyral resin in a solvent, blending the organosilicon compound, and heating at room temperature or under heating. A method in which silica particles are added after stirring and mixed uniformly is preferable in terms of storage stability of the liquid.

○Applicable substrates The composition of the present invention can be widely applied to metal substrates, including iron and iron alloys, aluminum and aluminum alloys, copper and copper alloys, zinc plating and zinc alloy plating, nickel metal plating and It is used for substrates with various types of plating such as plating, chrome plating, cadmium plating, etc., especially zinc plating, nickel plating, zinc plating, iron plating, etc. applied by methods such as electroplating and hot-dip plating.・Excellent rust prevention performance for zinc plating, tin/zinc alloy plating, etc., and steel plates or steel materials whose surfaces have been subjected to chromate treatment or phosphate treatment.

○Application method The composition of the present invention in a solution form can be easily applied to a metal substrate, and can be applied by known coating methods such as spray coating, tip coating, roll coating, and brush coating. After coating, by removing the solvent at room temperature or under heated conditions, a uniform coating film can be formed and the object of the present invention can be achieved.

The film thickness is preferably 0.1 to 100 g/n-r, more preferably 0.3 to 30 g/rr? A particularly preferable range is 0.5 to 1Og/durability, and it is a major feature of the composition of the present invention that it can impart remarkable rust prevention even with a film thickness of 10 g#rf or less.

Furthermore, the metal treated with the composition of the present invention can be used as it is, or can be overcoated 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 a coating method, and drying can be done by methods such as room temperature curing, hot air heating, high frequency heating, far infrared heating, ultraviolet irradiation, and electron beam irradiation. hardened. Examples of such coatings include undercoating/top coating of pre-coated steel plates, which are used extensively in fields such as building materials and home appliances; top coatings, which are used in fields such as home appliances; and electrodeposition coatings/intermediate coatings, which are used in fields such as automobiles.
Examples include topcoating, steel pipes/painting used in civil engineering and construction, etc.

"Function" The composition of the present invention achieves this effect by blending and dispersing silica particles into a composition consisting of a silicon compound, an epoxy resin, and a polyvinyl butyral resin, and it is possible to achieve this effect by blending and dispersing silica particles into a composition consisting of a silicon compound, an epoxy resin, and a polyvinyl butyral resin. Demonstrates excellent coating performance when applied to treated and phosphate treated galvanized steel sheets.

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

■When hydrolyzed under basic conditions, active 5iOH remains on the surface of the composite silica that precipitates, and the 5iOH group and the OH in the resin
This is because a reaction occurs with the base, creating a highly composite component of the resin component and silica component, which forms a dense film after coating.

■Composite silica that precipitates during hydrolysis under basic conditions has a uniform particle size and is evenly dispersed to form a uniformly dispersed coating after coating.

■Develops strong adhesion by reacting with highly reactive metal components other than Si or with OH groups in the resin, or by reacting or chemically bonding with underlying metals or chemical conversion treatment components. .

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

Hereinafter, examples will be specifically described.

"Examples and Comparative Examples" Synthesis example of composite silica Composite warping force 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 stirring device, and the temperature was raised to 70°C. After that, ethylamine 0.5
15.3 parts of pure water and 40 parts of isopropanol were gradually added dropwise, and the mixture was allowed to react at 70°C for 3 hours to obtain a cloudy liquid in which fine silica particles with an average particle size of 0.1 μm were precipitated. Ta. Furthermore, this cloudy liquid was concentrated under reduced pressure, and the heating residue was adjusted to 10%. The heating residue was determined as the residual rate by placing 1 g of the cloudy liquid in an aluminum cup and heating it at 150°C for 20 minutes.

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 stirring device, and after raising the temperature to 40°C, 0.5 part of ethylamine and pure A mixed solution of 9.2 parts of water and 30 parts of propylene glycol monomethyl ether was gradually added dropwise, and the reaction was continued at 40°C for 3 hours to obtain a slightly cloudy liquid in which fine silica particles with an average particle size of 0.02 μm were precipitated. . Furthermore, this cloudy liquid was concentrated under reduced pressure, and the heating residue was adjusted to 10%.

Composite Silica C 60 parts of tetraethoxysilane, 16.8 parts of zirconium tetrakis (acetylacetonate), and 130 parts of methyl ethyl ketone were charged into a reaction vessel equipped with a dropping funnel, a thermometer, and a stirring device, and the temperature was raised to 70'C. After that, 0.3 parts of ethylamine, 10.0 parts of pure water, 2 parts of methyl ethyl ketone
0 parts of the mixed solution was gradually added dropwise and reacted as it was at 70°C for 4 hours to obtain a slightly cloudy liquid in which composite silica with an average particle size of 0.05 μm was precipitated. Furthermore, this cloudy liquid was concentrated under reduced pressure, and the heating residue was adjusted to 10%.

Composite Silica D: In a reaction vessel equipped with a dropping funnel, a thermometer, and a stirring device, 40 parts of a partial compound of tetraethoxysilane (manufactured by Tama Chemical Industry, trade name: "Ethylsilicate-40") and 100 parts of propylene glycol monomethyl ether. Prepare at 70°
After raising the temperature to C, add 0.3 parts of ethylamine and 100 parts of pure water.
0 parts, propylene glycol monomethyl ether 25.
0 parts of the mixed solution was gradually added dropwise to the mixture and allowed to react at 70°C for 3 hours to obtain a cloudy white liquid in which fine silica particles were precipitated. To the resulting solution, 2.8 parts of tetra-1-propoxytitanium was gradually added dropwise to a solution diluted with 10 parts of propylene glycol monomethyl ether, and the mixture was reacted at 70°C for 2 hours to form composite silica with an average particle size of 0.1 μm. A cloudy white liquid was obtained. Furthermore, this cloudy liquid was concentrated under reduced pressure, and the heating residue was reduced to 10%.
Adjusted to.

Example 1 In a flask equipped with a stirrer, 60 parts of Epicoat 1004 (manufactured by Yuka Shell Epoxy ■), 20 parts of S-LEC 5LI (manufactured by Tanemizu Kagaku ■), 200 parts of composite silica A, 330 parts of propylene glycol monomethyl ether, and xylene 4 were added.
After stirring for 3 hours, 20 parts of γ-aminopropyltriethoxysilane (molecular weight 221) was added,
Further, 1 part of dibutyltin dilaurate was added as a catalyst and mixed and dissolved to obtain a homogeneous solution.

This composition was subjected to the following tests.

○ Creation of test plate First, galvanized electrolytic chromate treated plate (70X150
This solution was coated with a bar coater to a film thickness of 1 g/rrf on a test plate (maximum plate temperature reached 200°C x 60 seconds) and heated to obtain a test plate.

The characteristic measurement test was conducted as follows.

○Corrosion resistance test After making a cross cut on the test plate, salt spray test (J
15-Z-2317) It was carried out for 240 hours.

The results are summarized in Table 1. For comparison, an uncoated product was also tested, but red rust had developed after 240 hours.

The evaluation criteria were as follows.

○ - No rust △ White rust 2mm or less
After extruding JIS-5400 mm,
A salt spray test (J 15-Z-2371) was conducted for 240 hours. The results are summarized in Table 1.

The evaluation criteria were as follows.

○: No rust △ ・White rust on less than 10% of the processed area ×: White rust on more than 10% of the processed area ○ Adhesion test The adhesion test is based on primary adhesion and secondary adhesion. was tested.

The primary adhesion test was performed using 100 l phase spacing on the coating surface of each test plate.
The secondary adhesion test was carried out by carving out individual gongs, applying adhesive tape to these gongs, and peeling them off.
After painting, each test plate was immersed in warm water (pure water) at 4°C for 240 hours, then taken out, and within 30 minutes, it was immersed in 1
This was carried out by cutting grids at mm intervals and applying and peeling adhesive tape to the grids. Furthermore, the adhesion of the top coat was determined using Amirac #80 manufactured by Kansai Paint ■ on each test plate.
After coating 40μ of No. 5 White, primary adhesion and secondary adhesion were similarly tested. These results are summarized in Table 1.

○, no flaking △: flaky 10% or less ×: flaky 10% or more Examples 2 to 6 Composite silica A-D was mixed in the proportions shown in Table 1 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 conducted 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 proportions shown in Table 1 in the same manner as in Example 1 to obtain a homogeneous solution. Using this composition, a corrosion resistance test and an adhesion test were conducted in the same manner as in Example 1, and the results are summarized in Table 1.

Example 8 Aerosil 200 (manufactured by Nippon Aerosil ■) was mixed in the proportions shown in Table 1 in the same manner as in Example 1 to obtain a homogeneous solution.

Using this composition, a corrosion resistance test and an adhesion test were conducted in the same manner as in Example 1, and the results are summarized in Table 1.

Comparative Example 1 A homogeneous solution was obtained by using the same method as in Example 1 or without adding composite silica. Using this composition, a corrosion resistance test and an adhesion test were conducted in the same manner as in Example 1, and the results are summarized in Table 1.

Comparative Example 2 Aluminum oxide C was prepared in the same manner as in Example 1.
(manufactured by Nippon Aerosil ■) were mixed in the proportions shown in Table 1 to obtain a homogeneous solution. Using this composition, a corrosion resistance test and an adhesion test were conducted in the same manner as in Example 1, and the results are summarized in Table 1.

111 (hereinafter referred to as margin) - m - Table 1 (c) Effect of the invention The present invention, when applied to a metal base material, particularly a galvanized steel sheet, has an extremely thin film thickness of 5 glrd or less. It also has good workability and excellent rust prevention properties on processed parts, and the film is transparent and has strong resistance to fingerprint marks and scratches during various handling, making it an excellent base for painting when painted over it. Because of its excellent adhesion, it is widely used in various industries as a rust preventive treatment after chemical conversion treatment of steel sheets.

Claims (1)

[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 organic solvent-dispersible silica particles.