JP2003213457A - Fuel tank made of resin coated metal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel tank made of a resin coated metal which is treated with a surface treating agent not containing chromium and has the corrosion resistance better than that by chromate treatment. <P>SOLUTION: The fuel tank made of the resin coated metal is a metallic fuel tank having a plating layer essentially consisting of aluminum and/or zinc, a surface treated layer formed on this plating layer and a resin film layer formed on the surface treated film on at least outside surface side of metal plate constituting the tank, in which the surface treated film is formed of a surface treating composition obtained by adding (B) at least one kind of the compound selected from a phosphoric acid compound, hydrofluoric acid, metal halide or its salt, silicon halide or its salt and an organic acid or its salt to (A) an aqueous solution containing titanium obtained by reacting at least one of the titanium compound selected from hydrolyzable titanium, a low condensation product of the hydrolyzable titanium, titanium hydroxide, and a low condensation product of the titanium hydroxide with a hydrogen peroxide water. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin-coated metal fuel tank having excellent corrosion resistance, which is used in automobiles and motorcycles.

[0002]

2. Description of the Related Art Fuel tanks used in automobiles and motorcycles are required to have high corrosion resistance against gasoline, and lead-tin alloy plated steel sheets have been used for many years. In recent years, as interest in environmental issues has increased, there has been a strong demand for fuel tanks that do not use lead, which is a harmful substance,
The development of lead-free plating such as zinc plating, zinc-tin alloy plating, zinc-nickel alloy plating, zinc-aluminum alloy plating, and aluminum plating has been advanced. However, in a fuel tank that requires a high degree of corrosion resistance, chromate treatment is usually performed on these platings to maintain the corrosion resistance, but the toxicity of chromium poses a problem. Chromate treatment involves problems such as volatilization of chromate fumes in the treatment process, a large amount of wastewater treatment equipment cost, and problems due to elution of chromic acid from the chemical conversion coating. Hexavalent chromium compounds are IAR
C (International Agency for Researchon Cancer Rev
Many public institutions, including iew), have designated it as a carcinogen for the human body and are extremely harmful substances.

In order to deal with the above problem, Japanese Patent Laid-Open No. 9-15
Japanese Patent No. 7863 discloses a resin chromate film for the purpose of suppressing elution of chromium, but it is difficult to completely stop elution of chromium. In addition, JP-A-2000-
Japanese Patent No. 297384 discloses that an aluminum-based plated steel sheet is treated with a composition liquid containing an organic phosphoric acid and a thiocarbonyl group in an aqueous resin. Although the corrosion resistance is improved by etching a strong alumina oxide film formed on the surface layer of the plating with organic phosphoric acid, the effect decreases if the aluminum content in the plating decreases. .

An object of the present invention is to provide a resin-coated metal fuel tank which is treated with a surface treatment agent containing no chromium and which has a corrosion resistance higher than that of chromate treatment.

[0005]

Means for Solving the Problems As a result of intensive studies to achieve the above object, the present inventors have found that aluminum and / or
Alternatively, a surface treatment film obtained from a surface treatment composition obtained by mixing a specific rust preventive compound in an aqueous liquid containing a specific titanium is formed on the outer surface side of a tank having a plating layer containing zinc as a main component, The inventors have found that a resin-coated metal fuel tank having a resin coating layer formed on the coating achieves the above object, and completed the present invention.

Thus, according to the present invention, a plating layer containing aluminum and / or zinc as a main component, a surface treatment layer formed on the plating layer, and the surface treatment film are provided on at least the outer surface side of the metal plate constituting the tank. A metal fuel tank having a resin film layer formed thereon, wherein the surface-treated film is (A) hydrolyzable titanium, hydrolyzable titanium low condensate,
An aqueous liquid containing titanium obtained by reacting at least one titanium compound selected from titanium hydroxide and titanium hydroxide low condensate with aqueous hydrogen peroxide, (B) phosphoric acid compound, hydrofluoric acid A metal halide or a salt thereof, a silicon halide or a salt thereof, and a surface treatment composition obtained by adding at least one compound selected from an organic acid or a salt thereof. The present invention provides a resin-coated metal fuel tank for

The present invention will be described in more detail below.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The resin-coated metal fuel tank of the present invention comprises a plating layer containing aluminum and / or zinc as a main component, at least on the outer surface side of a metal plate constituting the tank.
It has a surface treatment layer formed on the plating layer and a resin film layer formed on the surface treatment film.

The surface treatment composition used for forming the surface treatment film is at least one selected from (A) hydrolyzable titanium, hydrolyzable titanium low condensate, titanium hydroxide and titanium hydroxide low condensate. (B) phosphoric acid-based compound, hydrofluoric acid, metal hydrofluoric acid or a salt thereof, metal halide or a metal halide thereof, in an aqueous solution containing titanium obtained by reacting a titanium compound of one kind with hydrogen peroxide solution. A salt, and at least one compound selected from organic acids or salts thereof are added.

Aqueous Liquid (A) The aqueous liquid which is the component (A) of the present invention is at least one selected from hydrolyzable titanium, hydrolyzable titanium low condensate, titanium hydroxide and titanium hydroxide low condensate. Is an aqueous liquid containing titanium obtained by reacting the titanium compound of 1 with hydrogen peroxide water. As the aqueous liquid, any conventionally known one can be appropriately selected and used without particular limitation as long as it is the above-mentioned liquid. The above-mentioned hydrolyzable titanium is a titanium compound having a hydrolyzable group that is directly bonded to titanium, and produces titanium hydroxide by reacting with water such as water or steam. Further, in the hydrolyzable titanium, all of the groups bonded to titanium may be hydrolyzable groups, or a part thereof may be a hydrolyzed hydroxyl group.

The above-mentioned hydrolyzable group is not particularly limited as long as it forms titanium hydroxide by reacting with water as described above. For example, a lower alkoxyl group or a group which forms a salt with titanium. (For example, a halogen atom (chlorine etc.), a hydrogen atom, a sulfate ion etc.) is mentioned.

As the hydrolyzable titanium containing a lower alkoxyl group as the hydrolyzable group, a compound represented by the general formula Ti
(OR) ₄ (in the formula, R are the same or different and each represents an alkyl group having 1 to 5 carbon atoms) tetraalkoxy titanium is preferable. Examples of the alkyl group having 1 to 5 carbon atoms include methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, iso-butyl group, sec-butyl group, tert-butyl group and the like. Can be mentioned.

As the hydrolyzable titanium having a group capable of forming a salt with titanium as the hydrolyzable group, titanium chloride,
Typical examples include titanium sulfate. Also,
The hydrolyzable titanium low-condensate is a low-condensate of hydrolyzable titanium described above. In the low condensate, all of the groups bonded to titanium may be hydrolyzable groups, or a part of them may be hydrolyzed hydroxyl groups.

Titanium chloride, titanium sulfate, etc., which form a salt with titanium, can be used as a low condensation product of orthotitanic acid (titanium hydroxide gel) by reacting an aqueous solution of this with an alkaline solution such as ammonia or caustic soda. .

Regarding the degree of condensation in the above-mentioned hydrolyzable titanium low condensate or titanium hydroxide low condensate, compounds having a degree of condensation of 2 to 30 can be used, and those having a degree of condensation of 2 to 10 are particularly preferable. preferable.

As the aqueous liquid (A), any conventionally known aqueous liquid may be used without particular limitation, as long as it is an aqueous liquid containing titanium obtained by reacting the above-mentioned titanium compound with hydrogen peroxide solution. You can Specifically, the following can be mentioned.

A titanyl ion hydrogen peroxide complex or a titanic acid (peroxotitanium hydrate) aqueous solution obtained by adding a hydrogen peroxide solution to a gel or sol of hydrous titanium oxide. (See JP-A-63-35419 and JP-A-1-224220.) Titania obtained by synthesizing titanium hydroxide gel produced from an aqueous solution of titanium chloride or titanium sulfate and a basic solution with hydrogen peroxide solution. Liquid for film formation. (JP-A-9-
71418 and JP-A-10-67516) In addition, in the above-mentioned titania film forming liquid, titanium chloride or titanium sulfate aqueous solution having a group forming a salt with titanium is reacted with an alkaline solution such as ammonia or caustic soda. This precipitates a titanium hydroxide gel called orthotitanic acid. Then, the titanium hydroxide gel is separated by decantation using water, washed well with water, and hydrogen peroxide water is added to decompose and remove excess hydrogen peroxide, whereby a yellow transparent viscous liquid can be obtained.

The precipitated orthotitanic acid is in a gel state in which the orthotitanic acid has been polymerized by polymerization of OH and hydrogen bonds and cannot be used as it is as an aqueous solution containing titanium.
When hydrogen peroxide water is added to this gel, a part of OH becomes a peroxidized state and dissolves as peroxotitanate ion, or it becomes a kind of sol state in which the polymer chain is divided into low molecules, and excess peroxide is added. Hydrogen decomposes into water and oxygen,
It can be used as an aqueous liquid containing titanium for forming an inorganic film.

Since this sol contains only oxygen atoms and hydrogen atoms in addition to titanium atoms, only water and oxygen are generated when it is converted into titanium oxide by drying or firing. Therefore, it is necessary for the sol-gel method and thermal decomposition of sulfates. It is not necessary to remove various carbon components and halogen components, and it is possible to form a crystalline titanium oxide film having a relatively high density even at a lower temperature than before.

After hydrogen peroxide is added to an aqueous solution of an inorganic titanium compound such as titanium chloride or titanium sulfate to form a peroxotitanium hydrate, a basic substance is added to the resulting solution, and the resulting solution is allowed to stand or heated to give a peroxotitanium hydrate. A titanium oxide forming solution obtained by forming a precipitate of a titanium hydrate polymer, removing at least dissolved components other than water derived from a titanium-containing raw material solution, and then allowing hydrogen peroxide to act thereon. (See JP-A-2000-247638 and JP-A-2000-247639) It is preferable to use an aqueous liquid (A) used in the present invention, which is produced by adding a titanium compound to hydrogen peroxide water. . As the titanium compound, it is preferable to use hydrolyzable titanium having a group which is hydrolyzed to become a hydroxyl group represented by the above-mentioned general formula, or a hydrolyzable titanium low-condensate thereof.

The mixing ratio of hydrolyzable titanium and / or low condensate thereof (hereinafter, these are simply referred to as "hydrolyzable titanium a") and aqueous hydrogen peroxide is 10 parts by weight of hydrolyzable titanium a. To 0.1 to 10 in terms of hydrogen peroxide
It is preferably 0 part by weight, particularly preferably 1 to 20 parts by weight. If it is less than 0.1 part by weight in terms of hydrogen peroxide, chelate formation is not sufficient and cloudy precipitation occurs. On the other hand, if it exceeds 100 parts by weight, unreacted hydrogen peroxide is likely to remain, and dangerous active oxygen is released during storage, which is not preferable.

The concentration of hydrogen peroxide in the hydrogen peroxide solution is not particularly limited, but it is preferably within the range of 3 to 30 weight from the viewpoint of the ease of handling and the solid content of the produced liquid which is related to the coating workability.

The aqueous liquid (A) containing the hydrolyzable titanium a is obtained by reacting the hydrolyzable titanium a with aqueous hydrogen peroxide at a reaction temperature of 1 to 70 ° C. for 10 minutes to 20 hours. Can be manufactured by

The aqueous liquid (A) containing the hydrolyzable titanium a is obtained by reacting the hydrolyzable titanium a with aqueous hydrogen peroxide, whereby the hydrolyzable titanium is hydrolyzed with water to form a hydroxyl group-containing titanium compound. It is presumed that hydrogen peroxide is then coordinated with the hydroxyl group-containing titanium compound produced by hydrogen peroxide, and the hydrolysis reaction and the coordination with hydrogen peroxide occur at the same time. It produces a chelate solution that is extremely stable in the range and can withstand long-term storage. The titanium hydroxide gel used in the conventional manufacturing method is partially three-dimensionalized by the Ti-O-Ti bond,
This gel and the product obtained by reacting hydrogen peroxide water are essentially different in terms of composition and stability.

By subjecting the aqueous liquid (A) containing the hydrolyzable titanium a to a heat treatment or an autoclave treatment at 80 ° C. or higher, a titanium oxide dispersion liquid containing crystallized titanium oxide ultrafine particles is obtained. If the temperature is lower than 80 ° C., crystallization of titanium oxide does not proceed sufficiently. The titanium oxide dispersion liquid thus produced has a particle size of titanium oxide ultrafine particles of 1 or less.
It is 0 nm or less, preferably 1 nm to 6 nm.
The appearance of the dispersion is semitransparent. If the particle diameter is larger than 10 nm, the film-forming property is deteriorated (a crack occurs at 1 μm or more), which is not preferable. This dispersion can be used as well.

The aqueous liquid (A) containing the hydrolyzable titanium a is applied to a steel plate material and dried, or heat-treated at a low temperature to form a dense titanium oxide film having excellent adhesion by itself. it can.

The heat treatment temperature is, for example, preferably 200 ° C. or lower, particularly 150 ° C. or lower to form the titanium oxide film.

The aqueous liquid (A) containing the hydrolyzable titanium a forms an amorphous titanium oxide film containing some hydroxyl groups at the above temperature. Also, 8
The titanium oxide dispersion liquid that has been subjected to the heat treatment at 0 ° C. or higher can form a crystalline titanium oxide film by simply applying it, and is therefore useful as a coating material for a material that cannot be heat treated.

In the present invention, the aqueous liquid (A) is obtained by reacting the same hydrolyzable titanium and / or hydrolyzable titanium low condensate as described above with hydrogen peroxide in the presence of titanium oxide sol. It is preferable to use an aqueous liquid (A1) containing titanium as described above. Examples of the hydrolyzable titanium and / or the hydrolyzable titanium low-condensate (hydrolyzable titanium a) include a titanium monomer containing a group that is hydrolyzed to form a hydroxyl group represented by the above general formula and its hydrolyzable property. Preference is given to using titanium low condensates.

In the above titanium oxide sol, the amorphous titania and the anatase titania fine particles are water (if necessary,
For example, it may be a sol dispersed in an aqueous organic solvent such as alcohol-based or alcohol ether-based).

As the titanium oxide sol described above, conventionally known ones can be used. Examples of the titanium oxide sol include (1) those obtained by hydrolyzing a titanium-containing solution such as titanium sulfate or titanyl sulfate, (2)
Titanium oxide aggregates such as those obtained by hydrolyzing an organotitanium compound such as titanium alkoxide, and (3) those obtained by hydrolyzing or neutralizing a titanium halide solution such as titanium tetrachloride are dispersed in water. Amorphous titania sol or the titanium oxide agglomerates may be calcined to form anatase-type titanium fine particles, which are dispersed in water.

The firing of the amorphous titania is performed at a temperature of at least the crystallization temperature of anatase, for example, 400 ° C to 50 ° C.
By firing at a temperature of 0 ° C. or higher, amorphous titania can be converted to anatase titania. Examples of the aqueous sol of titanium oxide include TKS-201 (manufactured by Teika Co., Ltd., trade name, anatase type crystal form, average particle size 6 nm), TA-15 (manufactured by Nissan Kagaku Co., Ltd., trade name,
Anatase type crystal form), STS-11 (Ishihara Sangyo Co., Ltd.)
Company name, trade name, anatase type crystal form) and the like.

When used for reacting hydrolyzable titanium a with hydrogen peroxide solution, the weight ratio of the titanium oxide sol and titanium hydrogen peroxide reactant is 1/99 to 99 /.
1, preferably about 10/90 to 90/10.
If the weight ratio is less than 1/99, the effect of adding titanium oxide sol such as stability and photoreactivity cannot be seen, and if it exceeds 99/1, the film-forming property is deteriorated, which is not preferable.

The mixing ratio of the hydrolyzable titanium a and the hydrogen peroxide solution is in the range of 0.1 to 100 parts by weight, particularly 1 to 20 parts by weight in terms of hydrogen peroxide with respect to 10 parts by weight of the hydrolyzable titanium a. Is preferred. If it is less than 0.1 part by weight in terms of hydrogen peroxide, chelate formation is not sufficient and cloudy precipitation occurs. On the other hand, if it exceeds 100 parts by weight, unreacted hydrogen peroxide is likely to remain, and dangerous active oxygen is released during storage, which is not preferable.

The concentration of hydrogen peroxide in the hydrogen peroxide solution is not particularly limited, but it is preferably within the range of 3 to 30 weight from the viewpoint of easiness of handling and solid content of the produced liquid which is related to coating workability.

The aqueous liquid (A1) can be produced by reacting hydrolyzable titanium a with hydrogen peroxide in the presence of titanium oxide sol at a reaction temperature of 1 to 70 ° C. for 10 minutes to 20 hours. .

The aqueous liquid (A1) is prepared by reacting hydrolyzable titanium a with aqueous hydrogen peroxide to hydrolyze the hydrolyzable titanium a with water to form a hydroxyl group-containing titanium compound, and then hydrogen peroxide. It is presumed that is coordinated to the hydroxyl group-containing titanium compound produced, and this hydrolysis reaction and coordination by hydrogen peroxide occur at the same time. It produces a chelating solution that can withstand storage of water. The titanium hydroxide gel used in the conventional production method is partially three-dimensionalized by the Ti—O—Ti bond, and the composition obtained by reacting this gel with hydrogen peroxide water is essentially different in terms of composition and stability. Further, by using the titanium oxide sol, it is possible to prevent a partial condensation reaction from occurring during the synthesis to increase the viscosity. The reason is that the condensation reaction product is adsorbed on the surface of titanium oxide sol,
It is considered to prevent polymerization in a solution state.

Further, an aqueous liquid (A1) containing titanium is added to 80
When heat treatment or autoclave treatment is performed at a temperature of not less than 0 ° C., a titanium oxide dispersion liquid containing crystallized titanium oxide ultrafine particles is obtained. If the temperature is lower than 80 ° C., crystallization of titanium oxide does not proceed sufficiently. The titanium oxide dispersion liquid thus produced has a titanium oxide ultrafine particle diameter of 10 nm or less,
It is preferably in the range of 1 nm to 6 nm. The appearance of the dispersion is semitransparent. The particle size is 10 nm
If it is larger, the film-forming property is deteriorated (a crack occurs at 1 μm or more), which is not preferable. This dispersion can be used as well.

The aqueous solution (A1) containing titanium can be applied to a steel plate material and dried, or can be heat-treated at a low temperature to form a dense titanium oxide film having excellent adhesion by itself.

The heat treatment temperature is, for example, preferably 200 ° C. or lower, particularly 150 ° C. or lower to form the titanium oxide film.

The aqueous liquid (A1) containing titanium forms an anatase type titanium oxide film containing a small amount of hydroxyl groups at the above temperature.

Among the above-mentioned aqueous liquid (A) containing titanium, the above-mentioned aqueous liquid using hydrolyzable titanium a and the aqueous liquid (A1) have excellent properties such as storage stability and corrosion resistance. Preference is given to using.

Other pigments and sols can be added to and dispersed in the aqueous liquid (A) containing titanium, if necessary. Examples of the additive include commercially available titanium oxide sol, titanium oxide powder, mica, talc, silica, barita, clay and the like.

Compound (B) The compound (B) added to the aqueous liquid (A) is a phosphoric acid compound, hydrofluoric acid, metal hydrofluoric acid or a salt thereof,
It is at least one compound selected from metal halides or salts thereof, and organic acids or salts thereof.

Examples of the phosphoric acid compound include phosphoric acid, strong phosphoric acid, triphosphoric acid, hypophosphoric acid, hypophosphoric acid, trimetaphosphoric acid, diphosphoric acid, diphosphoric acid, pyrophosphoric acid, Pyrophosphoric acid, metaphosphoric acid, metaphosphoric acid, phosphoric acid (orthophosphoric acid), monophosphoric acids such as phosphoric acid derivatives and salts thereof, condensed polyphosphoric acids such as tripolyphosphoric acid, tetraphosphoric acid, hexaphosphoric acid and condensed phosphoric acid derivatives And salts thereof and the like. One or two of these compounds
It is possible to use a combination of two or more species. Examples of the alkaline compound forming the above-mentioned salt include organic or inorganic alkaline compounds such as lithium, sodium, potassium and ammonium.

Further, it is preferable to use a phosphoric acid compound that is soluble in water.

Examples of the phosphoric acid compound include phosphoric acid (orthophosphoric acid), sodium pyrophosphate, sodium tripolyphosphate, sodium tetraphosphate, metaphosphoric acid, ammonium metaphosphate, sodium hexametaphosphate, etc. It is preferable to use this because it exhibits excellent effects such as anticorrosion of the coating film.

Examples of metal halides include titanium halides and zirconium halides, and examples of halogens of metal halides and silicon halides include fluorine, chlorine and iodine.
As the halogen, it is particularly preferable to use fluorine because fluorine has excellent performances such as storage stability of the coating agent, corrosion resistance and moisture resistance of the coating film, and examples thereof include titanium hydrofluoric acid and zirconium hydrofluoric acid. , And hydrosilicofluoric acid are preferred.

Preferred examples of the metal halide salt include titanium fluoride salts and zirconium fluoride salts. As the silicon halide salt, silicofluoride salt and the like can be mentioned as preferable ones. Examples of the component that forms a salt include lithium, sodium, potassium and ammonium.

Examples of the organic acid include organic carboxylic acids such as acetic acid, oxalic acid, glycolic acid, lactic acid, malic acid, citric acid, tartaric acid and gluconic acid, organic sulfonic acid, organic sulfinic acid, phenol, Thiophenol,
Organic nitro compound, organic phosphoric acid, 1-hydroxyethane-1,1-diphosphonic acid, aminotrimethylenephosphonic acid, N, N-bis (2-phosphoethyl) hydroxyamine, N, N-bis (2-phosphomethyl) hydroxy Examples thereof include organic phosphoric acid such as a hydrolyzate of amine and 2-hydroxyethylphosphonic acid dimethyl ether.

The organic acid salt is a mixture of an organic acid and an alkali compound. Examples of the alkaline compound that forms the salt include organic or inorganic alkaline compounds such as lithium, sodium, potassium and ammonium.

Further, it is preferable to use a water-soluble organic acid.

Examples of the organic acid include hydroxycarboxylic acids such as glyco-lactic acid, lactic acid, malic acid, citric acid, tartaric acid and gluconic acid, and hydroxyl group-containing organic acids such as 1-hydroxyethane-1,1-diphosphonic acid. Since phosphoric acid exerts an excellent effect on the storage stability of the coating agent or the anticorrosion property of the coating film, it is preferable to use this.

These compounds (B) can be used alone or in combination of two or more, and the compounding ratio is such that the compound (B) is added to 100 parts by weight of the solid content of the aqueous liquid (A) containing titanium. Is preferably 1 to 400 parts by weight, particularly preferably 10 to 200 parts by weight from the viewpoint of the balance between corrosion resistance and other coating film performance.

The aqueous liquid (A) may contain an aqueous organic polymer compound, if necessary, in addition to the above components. Examples of the aqueous organic polymer compound include epoxy resin, phenol resin, acrylic resin, urethane resin, olefin-carboxylic acid resin, nylon resin, polyvinyl alcohol, polyethylene glycol, polyglycerin, carboxymethyl cellulose, Examples thereof include hydroxymethyl cellulose and hydroxyethyl cellulose.

If necessary, the aqueous liquid (A) may contain a basic neutralizing agent such as ammonia, an organic amine compound, an alkali metal hydroxide or an alkaline earth metal. Examples of the basic neutralizing agent include ammonia,
Ethanolamine, triethylamine, lithium hydroxide, sodium hydroxide, potassium hydroxide and the like are preferred.

If necessary, the aqueous liquid (A) contains, for example, a thickener, a titanium oxide sol, a surfactant, an antibacterial agent, a rust preventive (tannic acid, phytic acid, benzotriazole, etc.), a color pigment. (Titanium oxide powder, etc.), pigments such as anticorrosion pigment, and the like can be contained.

If necessary, the aqueous liquid (A) may be, for example, methanol, ethanol or isopropyl alcohol.
It can be used after diluting it with a hydrophilic solvent such as ethylene glycol, ethylene glycol or propylene glycol.

If necessary, an extender pigment such as conventionally known mica, talc, silica, finely divided silica, barita and clay can be added to the aqueous liquid (A). These extender pigments have the advantage that they can improve the adhesion to the undercoat or topcoat by the anchoring effect.

If desired, the aqueous liquid (A) may further contain a lubricating function imparting agent. In particular, when a manufacturing process of forming a plated steel sheet on which a surface-treated film is formed and assembling it into a tank and then applying a paint to it is necessary, it is necessary to prevent scratches due to pressing.

Specific examples of the lubricating function imparting agent include fluororesin fine powder (eg, tetrafluoroethylene resin, tetrafluoroethylene-hexafluoropropylene copolymer resin, tetrafluoroethylene-perfluoroalkyl). Fine powder of vinyl ether copolymer resin, tetrafluoroethylene-ethylene copolymer resin, trifluoroethylene chloride resin, vinylidene fluoride resin, etc.), polyolefin wax (eg polyethylene wax, polypropylene wax, etc.) in one particle Examples of the lubricant include a lubricant containing a mixture of polyolefin and a fluororesin, graphite, boron nitride, carbon fluoride, and the like.

The average particle size of the lubricating function-imparting agent is 0.3.
.About.5.0 .mu.m, more preferably 0.5 to 3.0 .mu.m. When the average particle size of the wax becomes smaller, the effect of improving the lubricity tends to decrease, and when the average particle size becomes too large, the number of protruding parts of the wax from the film increases and the wax peels off during continuous processing, There is a problem in that it easily adheres to the mold.

Further, in continuous high-speed machining accompanied by heat generation, the surface temperature rises due to frictional heat, so that the low melting point lubricant function imparting agent becomes liquid and is not fixed to the lubricating film and adheres and deposits on the die. It is not preferable because it damages the metal surface. For high-speed processing involving heat generation, it is suitable to use a polyolefin wax having a softening point of 100 ° C or higher, preferably 130 to 150 ° C, and the wax is evenly fixed to the film even at high temperatures and is effective without damaging the surface of the galvanized steel sheet. Can exert its lubricating function. Further, as the lubricating function-imparting agent, a combination of the above-mentioned polyolefin wax and fluororesin powder, or a fluororesin powder alone also exhibits excellent performance.

The addition amount of the lubricating function-imparting agent is suitably in the range of 2 to 50 parts by weight, preferably 8 to 30 parts by weight, based on 100 parts by weight of the solid content of the aqueous liquid (A). If the added amount is small, the effect of improving the lubricity is small, and if it is too large, the gloss value of the film decreases, the surface smoothness is lost as well as the transparency, and the film elongation and adhesive force sharply decrease. The film is easily peeled off, the lubricity function cannot be sufficiently exhibited, and the press workability is deteriorated. Further, when the topcoat paint is applied on this, the adhesion of the topcoat film is deteriorated.

Manufacturing Method of Resin Coated Metal Fuel Tank As a manufacturing method of the resin coated metal fuel tank of the present invention,
For example, after forming an untreated steel plate and assembling it into a tank,
A method of applying a surface treatment composition on it, drying it, and further forming a resin film layer on the surface treatment film, forming a steel plate on which the surface treatment film is formed, assembling it into a tank, and then forming a resin on it. There is a method of forming a coating layer, a method of assembling a flat steel sheet on which a surface treatment layer and a resin coating layer are formed into a tank, and the like, but not particularly limited, but considering the balance between manufacturing cost and corrosion resistance, The method is particularly preferred. The method (1) has a problem of welding and a problem of corrosion resistance on the end surface, but it is less expensive than other methods and is effective depending on the application.

Since the inner surface of the tank is in direct contact with the fuel, the same plating and surface treatment film as that of the outer surface is usually used, and most of them do not have a resin film layer thereon. In recent years, the resin film layer has been improved in terms of resin, and those having high corrosion resistance have been developed by adding metal powder (see, for example, JP 2000-319790A and JP 11-129387A), It does not matter if there is a resin film layer.

As the steel material used in the resin-coated metal fuel tank of the present invention, for example, a steel material having a plating layer containing aluminum and / or zinc as a main component is suitable. An aluminum-plated steel sheet, a galvanized steel sheet, an aluminum-
Examples thereof include zinc alloy plated steel sheet, zinc-tin plated steel sheet, zinc-nickel plated steel sheet and the like. The basis weight of the plating layer is preferably about 10 to 300 g / m ² .

A surface-treated film can be formed by applying the surface-treating composition containing the above-mentioned aqueous liquid (A) and compound (B) as essential components to the surface of the plated steel sheet and drying it. The surface treatment composition is a coating method known per se on a plated steel sheet, for example, roll coating, curtain flow coating, dip coating, shower coating,
It can be applied by spray painting or the like. It is preferable that the surface treatment composition is usually dried under the condition that the maximum temperature reached by the material is about 60 to 250 ° C. for about 2 seconds to about 30 minutes.

The surface-treated film formed as described above has a dry film thickness of usually 0.001 to 10 μm, especially 0.1.
The range of 3 μm is preferable. If it is less than 0.001 μm, the corrosion resistance and water resistance are inferior, whereas if it exceeds 10 μm, the coating is cracked and the corrosion resistance is inferior.

The resin film formed on the surface-treated film may be a single film or a film of two or more layers.
Examples of the resin used for the resin coating layer include acrylic resin-based, polyester resin-based, epoxy resin-based, phenol-based, vinyl chloride-based resins, etc., and may be combined with a crosslinking agent such as amino resin or phenol resin. Good.
In particular, it is preferable to apply an epoxy-based coating as an undercoat for applications where strict corrosion resistance is required, and a vinyl chloride-based coating as an undercoat for applications where chipping resistance is required.

The uppermost resin film also serves to improve the appearance of the fuel tank, and may be a colored coating film containing generally known inorganic pigments, organic pigments, bright pigments, etc. It is more preferably a coating film.

Further, when a resin-coated steel sheet having a resin coating layer is manufactured first and then formed into a tank shape, a conductive pigment is added to enhance the weldability of the resin coating layer.
Further, a lubricant may be contained in the resin film layer in order to improve press moldability.

[0073]

EXAMPLES The present invention will be described more specifically below with reference to examples and comparative examples. Hereinafter, "parts" and "%" mean "parts by weight" and "% by weight", respectively. The present invention is not limited to the examples below.

Production of Titanium Aqueous Liquid Production Example 1 Aqueous ammonia (1: 9) was added dropwise to a solution of 5 cc of 60% titanium tetrachloride solution in 500 cc of distilled water to precipitate titanium hydroxide. After washing with distilled water, hydrogen peroxide solution 30
% Solution was added and stirred to obtain 70 cc of a yellow translucent viscous titanium-based aqueous solution (1) containing titanium.

Production Example 2 A mixture of 10 parts of tetra-iso-propoxytitanium and 10 parts of iso-propanol was stirred in a mixture of 10 parts of 30% hydrogen peroxide solution and 100 parts of deionized water at 20 ° C. for 1 hour with stirring. Dropped. Thereafter, the mixture was aged at 25 ° C. for 2 hours to obtain a yellow transparent slightly viscous titanium-based aqueous solution (2).

Production Example 3 A titanium-based aqueous liquid (3) was obtained under the same production conditions by using tetra-n-butoxytitanium in place of tetra-iso-propoxytitanium in the production example of the titanium-based aqueous liquid (2).

Production Example 4 Titanium-based aqueous liquid (4) was produced under the same production conditions using tetra-iso-propoxytitanium trimer in place of tetra-iso-propoxytitanium in the production example of titanium-based aqueous liquid (2). Got

Production Example 5 In the production example of the titanium-based aqueous solution (2), 3 times amount of hydrogen peroxide solution was added dropwise at 50 ° C. over 1 hour, and the mixture was aged at 60 ° C. for 3 hours. Got

Production Example 6 The titanium-based aqueous solution (3) was heat-treated at 95 ° C. for 6 hours to obtain a white-yellow translucent titanium-based aqueous solution (6).

Production Example 7 A mixture of 10 parts of tetra-iso-propoxytitanium and 10 parts of iso-propanol was mixed with TKS-203 (Taika).
1 part in a mixture of 5 parts (solid content), 10 parts of 30% hydrogen peroxide water, and 100 parts of deionized water.
The mixture was added dropwise with stirring at 0 ° C. over 1 hour. Then 10
After aging for 24 hours at 0 ° C., a yellowish transparent slightly viscous titanium-based aqueous solution (7) was obtained.

Production of Topcoat Paint Production Example 8 Watersol BC3010 (manufactured by Dainippon Ink and Chemicals, Inc., alkyd resin aqueous solution, solid content 59%) 152.5
Parts (90 parts by solid content), carbon black 5 parts, calcium carbonate 75 parts, ethylene glycol monobutyl ether 15 parts, ethyl-3-ethoxypropionate 9.
5 parts, Cymel 303 (manufactured by Mitsui Cytec, methyl etherified melamine resin, solid content 100%) 10 parts, triethylamine 1.5 parts and deionized water were mixed and dispersed to prepare an aqueous paint.

Production of Surface Treatment Composition Production Example 9 2% Titanium-based aqueous liquid (1) 50 parts, 60% 1-hydroxyethane-1,1-diphosphonic acid 2 parts and deionized water 48 parts were blended on the surface. A treatment composition A was obtained.

Production Examples 10 to 18 In the same manner as in Production Example 9, each surface treatment composition was prepared according to the formulation shown in Table 1.

[0084]

[Table 1]

Production of Resin-Coated Metal Fuel Tanks Examples 1 to 10 and Comparative Examples 1 to 3 Metal fuel tanks made of various steel plates were treated with an alkaline degreasing agent (“Chemical Cleaner 56 manufactured by Nippon CB Chemical Company”).
1B ") was used to degrease the solution, followed by washing with water, and then spraying the above various surface treatment compositions onto a metal fuel tank for treatment. The temperature of the treatment liquid was 30 ° C., and the spraying time was 30 seconds. 130 after spraying
It was baked and dried at 10 ° C. for 10 minutes. The water-based paint obtained in Production Example 8 was sprayed on the treated film to give a dry film thickness of 2
It was coated so as to have a thickness of 5 μm, and baked and dried at 130 ° C. for 30 minutes.

The combinations of various steel plates and surface treatment compositions are shown in Table 2 below. The abbreviations of steel plates in Table 2 indicate the following contents. X: 1.0 mm thick aluminum plated steel sheet (manufactured by Nisshin Steel Co., Ltd., product name "Alster") Y: 1.0 mm thick turn sheet steel sheet (manufactured by Nippon Steel) Obtained resin coated metals The corrosion resistance of the fuel tank was evaluated according to the following test method. The results are shown in Table 2.

Test method Anticorrosion property: Five scratches having a length of 50 mm were put on the outer surface of each resin-coated metal fuel tank with a knife at 20 mm intervals so as to reach the base material, and a salt spray test was conducted for 500 hours in accordance with JIS Z-2371. Rust width on one side from knife scratches (mm)
It evaluated by the average value of.

[0088]

[Table 2]

[0089]

The resin-coated metal fuel tank of the present invention comprises a phosphoric acid compound, hydrofluoric acid,
At least one compound (B) selected from a metal halide or a salt thereof, and an organic acid or a salt thereof acts as an inhibitor of metal corrosion, while the constituent component of the titanium-containing aqueous liquid (A) is heated. As a result, an amorphous titanium oxide film is formed, so the oxygen permeability and water vapor permeability of the film can be reduced. As shown in Table 2 above, conventional turn sheet steel sheets and harmful chromic acid are used. The corrosion resistance is equal to or higher than that using the chromate-treated steel sheet described above, and it is particularly useful for a metal fuel tank for automobiles and the like that requires severe corrosion resistance.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C23C 22/07 C23C 22/34 22/34 22/53 22/53 22/56 22/56 B60K 15/02 A (72) Inventor Jun Akui 4-17-1, Higashiyawata, Hiratsuka City, Kanagawa Kansai Paint Co., Ltd. F-term (reference) 3D038 CA06 CB01 CC19 4D075 AE03 BB87X CA13 CA33 CA44 DA13 DA20 DB02 DB05 DB07 DC13 DC41 EA06 EA07 EB07 EB13 EB17 EB19 EB20 EB22 EB32 EB33 EB37 EB38 EB39 EC01 EC07 EC08 EC52 4F100 AA04C AA06C AA21C AB01A AB03 AB10B AB12C AB18B AB40C AH02C AK01C AK01D AK25C AK33C AK53C BA04 DA01 EH71B EJ64C GB32 JB02 JB05B JB20C JM01C JM02C 4K026 AA02 AA07 AA09 AA13 BB08 CA16 CA18 CA23 CA24 CA25 CA26 CA28 CA35 CA37 CA38 CA41 4K044 AA02 AB10 BA10 BA12 BA17 BA21 BB04 BC02 CA11 CA16 CA53

Claims (14)

[Claims] 1. A plating layer containing aluminum and / or zinc as a main component, a surface treatment layer formed on the plating layer, and a surface treatment film formed on at least the outer surface side of a metal plate constituting the tank. A metal fuel tank having a resin film layer formed by using the surface treatment film, wherein the surface-treated film is at least one selected from (A) hydrolyzable titanium, hydrolyzable titanium low condensate, titanium hydroxide and titanium hydroxide low condensate. (B) a phosphoric acid-based compound, hydrofluoric acid, a metal halide or a salt thereof, a silicon halide or a salt thereof, in an aqueous solution containing titanium obtained by reacting a titanium compound of one kind with hydrogen peroxide And a resin-coated metal fuel tank formed from a surface treatment composition obtained by adding at least one compound selected from organic acids or salts thereof. 2. The aqueous liquid (A) containing titanium obtained by reacting hydrolyzable titanium and / or a low hydrolyzable titanium condensate with hydrogen peroxide in the presence of a titanium oxide sol. The resin-coated metal fuel tank according to claim 1, which is (A1). 3. The resin-coated metal fuel tank according to claim 1, wherein the aqueous liquid (A) is produced by adding a titanium compound to hydrogen peroxide water. 4. The resin-coated metal fuel tank according to claim 1, wherein the hydrolyzable titanium is a titanium monomer containing a group that hydrolyzes to become a hydroxyl group. 5. The hydrolyzable titanium low-condensation product is a low-condensation product of a titanium monomer containing a group which is hydrolyzed to become a hydroxyl group. Resin-coated metal fuel tank of. 6. The resin-coated metal fuel tank according to claim 5, wherein the low condensate has a degree of condensation of 2 to 30. 7. The hydrolyzable titanium has the general formula Ti (O
R) ₄ (wherein R is the same or different and has 1 to 1 carbon atoms)
5 represents an alkyl group of 5), The resin-coated metal fuel tank according to any one of claims 1 to 6, wherein 8. The mixing ratio of the titanium compound and the hydrogen peroxide solution is 0.1 to 100 parts by weight of hydrogen peroxide to 10 parts by weight of the titanium compound.
The resin-coated metal fuel tank according to any one of items 1 to 7. 9. The phosphoric acid compound is at least one compound selected from phosphoric acid, metaphosphoric acid, condensed phosphoric acid, condensed metaphosphoric acid, phosphate, metaphosphate, condensed phosphate and condensed metaphosphate. The resin-coated metal fuel tank according to any one of claims 1 to 8. 10. The metal halide or a salt thereof is at least one compound selected from titanium halides, titanium halide salts, zirconium halides, and zirconium halide salts. The resin-coated metal fuel tank described. 11. The organic acid is at least one selected from hydroxycarboxylic acid and hydroxyl group-containing organic phosphorous acid.
The resin-coated metal fuel tank according to any one of claims 1 to 10, which is a hydroxy organic acid. 12. The resin-coated metal fuel tank according to claim 1, wherein the surface treatment composition further contains an aqueous organic polymer compound. 13. The aqueous organic polymer compound is at least one of an epoxy resin, a phenol resin, an acrylic resin, a urethane resin, a polyvinyl alcohol resin, a polyalkylene glycol resin, and an olefin-carboxylic acid resin. The resin-coated metal fuel tank according to claim 12, which is an aqueous organic polymer compound selected from the resins described in 1. 14. The resin-coated metal fuel tank according to any one of claims 1 to 13, wherein the surface treatment composition is an aqueous liquid having a pH of 1 to 7.