JPH07163941A - Resin-coated aluminum-plated steel sheet excellent in press formability and coating suitability after working and its production - Google Patents

Abstract

PURPOSE:To produce a resin-coated aluminum-plated steel sheet excellent in lubricity, capable of press formation with severe working and excellent in coating suitability, particularly electrodeposition coating suitability after working. CONSTITUTION:In the resin-coated aluminum-plated steel sheet excellent in press formability and coating suitability after working, the resin coating film consisting mainly of a resin incorporated with 1.0-20wt.% cross-linking epoxy resin into a urethane resin having active hydrogen such as carboxyl group and hydroxyl group in molecule and containing 0.5-20wt.% spherical polyethylene wax particles and 1-30wt.% (in terms of SiO2) linear colloidal silica is formed on the surface of the steel sheet by 0.2-3g/m<2> coating weight. Then, the spherical polyethylene wax particles are held in the coating film in spherical state.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin-coated aluminum-based plated steel sheet having excellent press formability and paintability after processing, which is used for automobiles, household electric appliances, building materials, etc., and a method for producing the same.

[0002]

2. Description of the Related Art Generally, when pressing a steel plate,
Press oil is applied to the surface of the steel sheet to improve its workability. However, if the press oil is applied to the surface of the steel sheet in this way, the press oil is scattered during the press working of the steel sheet, which deteriorates the working environment or causes a pollution problem. There is a problem such as needing.

Therefore, in order to obtain good press workability without using press oil, various methods have been conventionally proposed for subjecting a steel sheet to a surface treatment. For example, a method of forming a mill bond film or a wax film on the surface of a steel sheet, or using a resin emulsion or a resin aqueous solution containing an inorganic or organic solid lubricant as a coating agent, applying this to the surface of the steel sheet, and drying. Then, a method of forming a resin film is known. In particular, the latter method of forming a resin film on the surface of a steel sheet is widely used as a surface treatment method for products that undergo strong processing or where degreasing is omitted after processing, and for products that require painting. Has been.

As described above, as a method of forming a resin film on the surface of a steel sheet to obtain a resin-coated steel sheet, a conventional method is, for example,
As described in JP-A-63-162886, a method of using a coating agent prepared by blending a carboxylated polyolefin resin with an epoxy resin, or as described in JP-A-3-17189. In addition, a coating agent made by adding fluorine-based resin particles as a solid lubricant to urethane-modified polyolefin resin,
Further, a method of using a coating agent obtained by adding wax particles to the above is known.

As described above, according to the resin-coated steel sheet in which the fluorine-based resin particles are contained as the solid lubricant in the resin film, the surface of the fluorine-based resin particles is inactive, so that the resin forming the resin film is Has poor adhesion, the fluororesin particles in the film are wound around the roll during the production of the resin-coated steel sheet and adhere to the product, which deteriorates the appearance of the product and the coatability after processing. Further, according to the resin-coated steel sheet on which a resin film containing wax particles as a solid lubricant is formed, due to its low specific gravity and poor compatibility with the resin liquid, it is concentrated on the surface of the film to form a film. When dried at a temperature above the softening point of the wax, the wax particles soften and melt, and adhere unevenly to the surface of the film after the film is dried, so an effect as a lubricant is obtained, but after processing Paintability is significantly reduced.

Moreover, when further coating is required after forming the resin film on the steel sheet, particularly when powder coating or electrodeposition coating is performed, these solid lubricants cannot be used for the above reason. In particular, when the fluorine-based resin particles are used as the solid lubricant, the fluorine-based resin particles dispersed in the coating cannot be easily removed by degreasing, so that it is difficult to improve the coating property.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems in the conventional resin-coated steel sheet, in which a solid lubricant is contained in a coating agent containing a resin for forming a resin film. Spherical polyethylene wax particles are dispersed as an agent, and when such a coating agent is applied to the surface of an aluminum-plated steel sheet and dried, it is heated and dried at a temperature not higher than the softening point of the spherical polyethylene wax particles to form a resin film. By forming the, it has excellent lubricity and can perform press forming of strong processing,
The present invention has been accomplished by finding that a resin-coated aluminum-based plated steel sheet having excellent coatability after processing, particularly, electrodeposition coatability, can be obtained.

That is, the present invention provides a resin-coated aluminum-plated steel sheet which is excellent in lubricity, can be press-formed by strong working, and is excellent in coatability after processing, in particular, electrodeposition coatability, and such a resin coating. It is an object to provide a method for manufacturing an aluminum-plated steel sheet.

[0009]

A resin-coated aluminum-plated steel sheet having excellent press formability and coatability after processing according to the present invention is a urethane-based resin having active hydrogen such as carboxyl group or hydroxyl group in the molecule. Room temperature cross-linkable epoxy resin Mainly resin containing 1.0 to 20% by weight, spherical polyethylene wax particles 0.5 to 20% by weight
And a resin coating containing 1 to 30% by weight of chain-like colloidal silica as SiO ₂ is formed on the surface of the aluminum-based plated steel sheet with an adhesion amount of 0.2 to 3 g / m ² , and the spherical polyethylene wax particles are spherically coated. It is characterized by being held inside.

According to the present invention, such a resin-coated aluminum-plated steel sheet is a room temperature cross-linking type epoxy resin in solid content conversion to urethane resin having active hydrogen such as carboxyl group and hydroxyl group in the molecule. 1.0-20
An aluminum-plated steel sheet mainly composed of a resin containing 0.5% by weight of spherical polyethylene wax particles in terms of solid content and 0.5 to 20% by weight of linear colloidal silica as SiO _{2 in an amount} of 1 to 30% by weight. The surface of the spherical polyethylene wax particles are dried at a temperature equal to or lower than the melting point of the spherical polyethylene wax particles, and the spherical polyethylene wax particles are held in a spherical shape in the resin film, and the adhesion amount is 0.2 to 2.
It can be obtained by forming a resin film in the range of 3 g / m ² .

In the resin-coated aluminum-plated steel sheet according to the present invention, among the resin components forming the resin film, a urethane resin having active hydrogen in the molecule, for example, a carboxyl group or a hydroxyl group is used as a main component. The urethane resin is prepared as an aqueous resin such as an aqueous dispersion or an aqueous solution. In the present invention, although not limited in any way, an aqueous urethane resin containing water or water containing a small amount of a water-soluble organic solvent such as alcohol as a medium is preferably used.

The urethane resin having active hydrogen in the molecule is not particularly limited, but can be obtained by various methods as described below. For example, a urethane prepolymer having a terminal isocyanate group is reacted with a compound having a sulfonic acid group or a carboxyl group together with an amino group or a hydroxyl group, for example, an aqueous solution of an alkali or ammonium salt of diaminocarboxylic acid to simultaneously perform chain extension and emulsification. Or a polyhydroxyl compound, a compound having a quaternary ammonium group and a hydroxyl group in the molecule, or a compound having an epoxy group and a hydroxyl group in the molecule is reacted with polyisocyanate and mixed with water. A method etc. can be mentioned.

Polyethers which are polymerization products or copolymerization products of tetrahydrofuran, propylene oxide, ethylene oxide and the like, polyhydric alcohols such as ethylene glycol, propylene glycol, butanediol and hexanediol, and maleic acid and succinic acid. A polyhydroxyl compound represented by a polyester, a polyacetal, a polyesteramide, a polythioether or the like, which is obtained by a dehydration condensation reaction with a polycarboxylic acid such as adipic acid or phthalic acid, or a ring-opening polymerization reaction of a cyclic ester, 1 Aromatic aromatic polyisocyanates such as 5,5-naphthalene diisocyanate, 4,4-diphenylmethane diisocyanate, phenylene diisocyanate and toluene diisocyanate, or hexamethylene diisocyanate, dicyclohexylmethane diisocyanate , Polyisocyanates typified by aliphatic diisocyanates such as xylylene diisocyanate and the above polyhydric alcohols and chain extenders typified by low molecular weight diamines such as ethylenediamine, propylenediamine, diethylenetriamine, hexamethylenediamine and xylylenediamine. A method of reacting and with tetrahydrofuran, acetone, methyl ethyl ketone, ethyl acetate, toluene or the like in an inert organic solvent to obtain urethane, and adding water containing an appropriate amount of an emulsifier, and then distilling off the inert organic solvent. Can be mentioned.

Further, a urethane prepolymer having a terminal isocyanate group is reacted with a polyalkylene polyamine such as diethylene triamine to obtain a polyurethane urea polyamine, to which an aqueous solution of an acid is added, or the polyurethane urea polyamine is subjected to epichlorourea. After adding hydrin, a method of adding an aqueous solution of an acid thereto, or after reacting the above-mentioned polyurethaneurea polyamine, its alkyl isocyanate adduct or epihalohydrin adduct with a cyclic dicarboxylic acid anhydride, an aqueous solution of a basic substance. A method of mixing the above-mentioned polyurethane urea polyamine or its epihalohydrin adduct with sultonic acid, lactone acid,
React with sodium monohalogenate carboxylate,
Alternatively, a method of reacting (meth) acrylic acid ester, acrylonitrile, etc., followed by hydrolysis, and then mixing with water can be mentioned.

In addition to the above, a compound having a terminal amino group obtained by reacting a diamine with a urethane prepolymer having a terminal hydroxyl group or an isocyanate group obtained from a polyhydroxy compound and polyisocyanate is emulsified in water using an emulsifier. After this, a method of adding polyisocyanate to polymerize, etc. can be mentioned.

In the present invention, as the urethane resin having active hydrogen in the molecule, especially JIS K-72 is used.
Shore hardness of the film measured according to 15 is 30 to 7
Those having a pencil hardness of H or higher are preferably used.

In the production of the resin-coated steel sheet according to the present invention, the coating agent used is, as the resin component for forming the resin film, as described above, the urethane resin having active hydrogen in the molecule and the crosslinking agent thereof. Contains a room temperature crosslinkable epoxy resin. Thus, by using the urethane resin as the resin component in the coating agent for forming the resin film and the room temperature cross-linking type epoxy resin as the cross-linking agent, the desired film strength can be obtained and It is possible to obtain a resin-coated steel sheet that suppresses scratches and black discoloration due to the temperature rise of the mold in press molding and extreme pressure on the sliding surface, and that has excellent corrosion resistance, paintability, and paintability after processing. it can.

That is, according to the present invention, when the urethane resin has active hydrogen in the molecule, for example, a carboxyl group, the epoxy group of the epoxy resin reacts with the carboxyl group to form an ester group. To form crosslinks, thus making the film dense and tough, and improving press formability and corrosion resistance.

Other than epoxy resins, for example, melamine-based, isocyanate-based, and aziridine-based crosslinking agents are known as crosslinking agents for urethane-based resins having a carboxyl group in the molecule. However, the resulting resin-coated steel sheet is inferior in coatability. But,
According to the present invention, when an epoxy resin is used as a cross-linking agent for urethane resin having active hydrogen in the molecule, preferably a carboxyl group, the epoxy resin reacts with the carboxyl group of the urethane resin to form a hydroxyl group. It is considered that the active hydrogen in the hydroxyl group contributes to the adhesiveness, and excellent coating properties can be secured.

In the present invention, the room temperature cross-linking type epoxy resin has a high reactivity with active hydrogen such as a carboxyl group and a good compatibility with the urethane type resin, and further softens the spherical polyethylene wax particles. Crosslinking reaction occurs at a temperature lower than the point, and those having good liquid stability are preferably used. Examples of such epoxy resins include Denacol EX-313, EX-314, and EX-.
321, EX-421, EX-512, EX-521,
EX-147, EX-810, EX-614, (above,
Nagase Chemical Industry Co., Ltd.) Rica Bond EX-8S, AP
-355B (manufactured by Chuo Rika Kogyo Co., Ltd.) and the like.

Such a room temperature cross-linking type epoxy resin is
In the resin film, it is preferably contained in the range of 1.0 to 20% by weight. When the content of the room temperature crosslinkable epoxy resin in the resin film is less than 1.0% by weight, the urethane resin in the resin film is insufficiently crosslinked and the hardness of the obtained resin film is not improved. But,
When it is contained in an amount of more than 20% by weight, the obtained resin film is deteriorated in lubricity and, at the same time, scratches are likely to occur in press molding. Furthermore, the unreacted epoxy resin remains in the obtained resin film, and as a result, the resin-coated steel sheet obtained is deteriorated in corrosion resistance, particularly in corrosion resistance after processing. In particular, in the present invention, the room temperature cross-linking type epoxy resin is 1 to 1 in the resin film.
Most preferably, it is contained in the range of 0% by weight.

Furthermore, in the resin-coated aluminum-plated steel sheet according to the present invention, the resin film contains 0.5 to 20% by weight of spherical polyethylene wax particles and 1 to 30% by weight of chain colloidal silica as SiO ₂ . Such a resin film is formed on the surface of the steel sheet in the range of 0.2 to 5 g / m ² of adhesion, and according to the present invention, the spherical polyethylene wax particles retain their spherical shape. , Contained in the resin film.

In the resin-coated aluminum-based plated steel sheet according to the present invention, when the content of the spherical polyethylene wax particles in the resin film is less than 0.5% by weight, the resulting resin film has poor lubricity and press formability. On the other hand, if the improvement is still insufficient, and if it exceeds 20% by weight, there is no particular problem in terms of lubrication performance, but the adhesion between the resin film obtained and the aluminum-plated steel sheet is poor, and the film peels off during press working. As a result, the corrosion resistance after processing becomes poor. Further, with respect to coatability as well, the adhesion between the film and the paint is reduced. Particularly, in the present invention, the content of the spherical polyethylene wax particles in the resin film is 1 to 10% by weight.
It is preferably in the range of.

The softening point of the spherical polyethylene wax particles used in the present invention is preferably in the range of 100 to 140 ° C. When the softening point of the spherical polyethylene wax particles is lower than 100 ° C, the polyethylene wax particles are softened and liquefied due to the temperature rise of the mold during press working, causing a liquid cut state between the steel plate and the mold. , Workability deteriorates. On the other hand, when the softening point of the spherical polyethylene wax particles exceeds 140 ° C., the obtained resin film does not have good lubricating performance.

According to the present invention, when the required coating agent is applied to the surface of an aluminum-plated steel sheet and is dried, the temperature is lower than the melting point of the spherical polyethylene wax particles, and therefore higher than 100 ° C. The spherical polyethylene wax particles are heated and dried at a low temperature to form a resin film while maintaining the spherical polyethylene wax particles in the resin film in a spherical shape. Thus, the lubricity of the obtained resin film can be further enhanced.

Further, when degreasing is performed as a pretreatment for coating the product after press working, the spherical polyethylene wax particles are peeled off from the surface of the resin coating by the degreasing, and the diameter of the resin coating surface is reduced. 0.1-3 μm
Many pin poles occur. The pin pole exerts an anchoring effect that significantly improves the adhesion between the resin film and the paint during painting. In particular, this pin pole is often generated by degreasing using a solvent, and is more effective.
Preferred examples of the solvent used for degreasing include trichloroethylene, trichloroethane, acetone and the like. Even in alkaline degreasing, similar effects can be expected by controlling the pH and temperature of the degreasing liquid.

The effect of the generation of pin poles on the resin film described above is more effective when the electrodeposition coating is carried out after the press working. That is, the hydrogen gas generated at the interface between the steel plate and the coating material during electrodeposition coating efficiently escapes from this pin pole, so that the coating appearance is greatly improved.

In the present invention, in order to maximize the effect of such spherical polyethylene wax particles, it is preferable that the spherical polyethylene wax particles have a particle diameter in the range of 0.1 to 3 μm. When the particle size exceeds 3 μm, it becomes difficult to uniformly disperse it in the water-based urethane-based resin, and as a result, the adhesion of the obtained resin film to the steel sheet and the adhesion to the coating material deteriorate. On the other hand, when the particle size of the spherical polyethylene wax particles is smaller than 0.1 μm, the effect of improving the lubricity and corrosion resistance of the resin film cannot be obtained by adding the spherical polyethylene wax particles.

In the present invention, examples of the spherical polyethylene wax include Daijet E-17 (manufactured by Kyowa Kagaku Co., Ltd.), KUE-1, KUE-5, and KUE-.
8 (manufactured by Sanyo Kasei Co., Ltd.), Chemipearl W-100,
W-200, W-300, W-400, W-500, W
F-640, W-700 (Mitsui Petrochemical Industry Co., Ltd.
Commercially available products such as Elepon E-20 (Nippon Kagaku Co., Ltd.) and the like can be preferably used.

Further, in the colloidal silica used in the present invention, the silica particles are connected in a chain form, the length thereof is 40 to 300 nm, and the content in the resin film is in the range of 1 to 30% by weight. Since the shape of the colloidal silica is chain-like, the bonding property and film-forming property of the resin film are superior to those in the case of using spherical colloidal silica. It significantly improves the scratch resistance of the composite resin film during press working. Further, the adhesion to the paint is also superior to that when spherical colloidal silica is used. However, when the particle diameter of the chain colloidal silica used is 40 nm or less, there is no difference from the characteristics of the spherical colloidal silica,
On the other hand, when the length exceeds 300 nm, it induces gelation of the coating agent used for forming the resin film,
It becomes difficult to apply it to the surface of an aluminum-plated steel sheet.
Such chain colloidal silica used in the present invention is, for example, Snowtex UP (manufactured by Nissan Chemical Co., Ltd.).
A commercially available product can be obtained.

In the present invention, when the content of chain colloidal silica in the resin film is less than 1% by weight,
The obtained film has insufficient corrosion resistance and paintability, while
When it exceeds 30% by weight, silica acts as a lubricant, which increases the coefficient of friction of the film and reduces the lubricity, thereby deteriorating the corrosion resistance and paintability after processing. In particular, in the present invention, in order to maximize the effect of the chain colloidal silica used, the content in the resin film is preferably in the range of 5 to 25% by weight.

In the present invention, when the amount of such a resin film deposited on the aluminum-plated steel sheet is less than 0.2 g / m ² , the required lubrication effect and the corrosion resistance and paintability after processing are required in the heavy working. Can't get However, when the adhered amount exceeds 3 g / m ² , the peeling amount of the composite resin film increases during press working of the steel sheet, and for example, in press molding, the peeling film accumulates in the mold, which causes trouble in press molding. .

In the resin-coated aluminum-based plated steel sheet according to the present invention, the room temperature cross-linking epoxy resin is dispersed in the above-mentioned water-based urethane resin together with the dispersion of spherical polyethylene wax particles and the chain colloidal silica within the predetermined range. Then, a coating agent is prepared, applied on an aluminum-plated steel sheet, and dried at a temperature not higher than the softening point of the spherical polyethylene wax.

[0034]

As described above, according to the present invention, the urethane resin containing the room temperature crosslinking type epoxy resin is mainly used,
By applying a coating agent containing spherical polyethylene wax dispersion and chain colloidal silica to an aluminum-plated steel sheet and drying it below the softening point of the spherical polyethylene wax, it is possible to perform strong press forming without applying press oil. In addition, it is possible to form a resin film having excellent corrosion resistance and coatability after processing. The resin-coated aluminum-based plated steel sheet having such high lubricity, high corrosion resistance and coatability can be directly coated after press working, and by degreasing, electrodeposition coating becomes possible.

[0035]

The present invention will be described below with reference to examples.
The present invention is not limited to these examples. In the following, the active hydrogen contained in the urethane resin is a carboxyl group.

Example 1 Chromate-treated vapor-deposited aluminum-plated steel sheet (aluminum adhesion amount 20 g / m ² , chromium adhesion amount 20
mg / m ² ) was used as the material steel plate. Further, in the following, the amount of each component is the amount in terms of solid content after forming the resin film. 0.5-25% by weight of room temperature cross-linking epoxy resin was added to urethane resin (Super Flex manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) having a Shore D hardness of 51, and spherical polyethylene wax (particle diameter 1-2 μm). ,
10% by weight of particles having a softening point of 110 ° C. and 10% by weight of chain colloidal silica as SiO ₂ were added and dispersed in a resin to prepare a coating agent.

This coating agent was applied to the surface of the above steel sheet with a squeezing roll so that the dry adhesion amount was 1 g / m ² , dried at 80 ° C. to form a resin film, and resin-coated vapor-deposited aluminum according to the present invention was formed. A plated steel sheet was obtained. The resin-coated steel sheet thus obtained was subjected to a sliding test, a press test, a salt spray test and a coating test to examine the dynamic friction coefficient, mold galling resistance, corrosion resistance and coating adhesion.

For comparison, the same urethane resin as above was blended with 5% by weight of a melamine-based, isocyanate-based or aziridine-based cross-linking agent to prepare a coating agent. And, for them, sliding test,
A press test, a salt spray test and a coating test were conducted to examine the dynamic friction coefficient, mold galling resistance, corrosion resistance and coating adhesion.

The coefficient of kinetic friction was determined from the load by sliding at a pressure of 150 kg using a sliding tester. The mold galling resistance and blackening resistance were visually examined for mold galling and black discoloration on the sliding surface of the molded product after press molding using a single-shot press tester. Also, the corrosion resistance is JIS Z-2371.
The salt spray test was conducted according to the method described in 1. Regarding the coating film adhesion, after coating with an acrylic-based and melamine alkyd-based coating, the adhesion of the coating film was checked by cross-cutting and cross-cutting Erichsen. The results are shown in Table 1.

[0040]

[Table 1]

Example 2 5 wt% of a room temperature cross-linking epoxy resin was mixed with a urethane resin (Shore D Chemical Co., Ltd. Neotan) having a Shore D hardness of 67 for a resin film, and a spherical polyethylene wax (having a particle diameter of 1 to 1). 2 μm, softening point 100 ° C) Particles 10% by weight
And 10% by weight of chain colloidal silica as SiO ₂ were added and dispersed to prepare a coating agent.

For comparison, the particle size is 10 to 20 n.
m spherical spherical colloidal silica ₂As 10% by weight
In addition, it was dispersed to prepare a coating agent. This
Each coating agent prepared in this way is the same as above.
Dry adhesion amount of 1g / m on the surface of steel sheet²Squeeze so that
Apply on a roll and dry at 80 ° C to form a resin film
Then, a resin-coated vapor-deposited aluminum-plated steel sheet was obtained.
About this resin-coated steel sheet, as in Example 1,
I checked the performance. The results are shown in Table 2.

[0043]

[Table 2]

Example 3 As in Example 1, 5% by weight of a room temperature crosslinkable epoxy resin was added to a urethane resin having a Shore D hardness of 51 (Superflex manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.), and Then, 10% by weight of chain colloidal silica (as SiO ₂ ) and 10% by weight of spherical polyethylene wax (softening point 110 ° C.) particles having a particle diameter of 0.1 to 3 μm were added and dispersed to prepare a coating agent.

For comparison, 10% by weight of spherical polyethylene wax particles having a particle size smaller than 0.1 μm and 4 μm (softening point 110 ° C.) particles were added and dispersed to prepare a coating agent. Each coating agent thus prepared was applied to the surface of the same steel sheet as above by a squeeze roll so that the dry adhesion amount was 1 g / m ^2, and
A resin film was formed by drying at 0 ° C. to obtain a resin-coated vapor-deposited aluminum-plated steel sheet. The results are shown in Table 3.

[0046]

[Table 3]

Example 4 As in Example 1, 5% by weight of a room temperature crosslinkable epoxy resin was added to a urethane resin having a Shore D hardness of 51 (Superflex manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), and , Spherical polyethylene wax (particle diameter 1 to 2 μm, softening point 100 ° C.) particles 0 to 25% by weight and chain colloidal silica particles 0 to 35% by weight as SiO ₂ ,
A coating agent was prepared.

Each of the coating agents prepared in this manner was applied to the surface of the same steel sheet as described above in a dry adhesion amount of 1 g / m 2.
^It was applied with a squeezing roll so that it would be ² , dried at 80 ° C. to form a resin film, and a resin-coated vapor-deposited aluminum-plated steel sheet was obtained. The results are shown in Tables 4 and 5.

[0049]

[Table 4]

[0050]

[Table 5]

Example 5 As in Example 1, 5% by weight of a room temperature crosslinkable epoxy resin was added to a urethane resin having a Shore D hardness of 51 (Superflex manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), and A spherical polyethylene wax (particle diameter 1 to 2 μm, softening point 100 ° C.) particles 10% by weight and chain colloidal silica particles 10% by weight as SiO ₂ were dispersed to prepare a coating agent.

Each of the coating agents thus prepared was applied to the surface of the same steel sheet as described above in a dry adhesion amount of 0.2 to 3 g.
/ M ² was applied with a squeezing roll and dried at 80 ° C. to form a resin film to obtain a resin-coated vapor-deposited aluminum-plated steel sheet. The results are shown in Table 6.

[0053]

[Table 6]

Example 6 As in Example 1, 5% by weight of a room temperature crosslinkable epoxy resin was added to a urethane resin having a Shore D hardness of 51 (Superflex manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), and A spherical polyethylene wax (particle diameter 1 to 2 μm, softening point 100 ° C.) particles 10% by weight and chain colloidal silica particles 10% by weight as SiO ₂ were dispersed to prepare a coating agent.

The coating agent thus prepared was applied to the surface of the same steel sheet as described above by a squeezing roll so that the dry adhesion amount was 1 g / m ^2, and dried at 80 ° C. to form a resin film, A resin-coated vapor-deposited aluminum-plated steel sheet was obtained. The resin-coated vapor-deposited aluminum-plated steel sheet was subjected to vapor degreasing with trichloroethane and alkaline spray degreasing (liquid temperature) electrodeposition coating. The results are shown in Table 7.

[0056]

[Table 7]

The electrodeposition coating was carried out using an acrylic cation electrodeposition coating (Aqua No. 4800) manufactured by NOF CORPORATION. The coating conditions and the evaluation of coating properties after coating are shown below. Coating conditions Bath temperature 28 ° C Polar ratio (+/-) 1/4 to 1/6 Energizing time 2 minutes Energizing voltage 160 to 230V Coating film thickness 25 μm Washed with water Shower with water Washing conditions 180 ° C × 20 minutes Evaluation of coating film physical properties Cross-cut test: After painting, cut a cross-cut at 1 mm intervals on the steel plate,
A tape peel test was performed to investigate the peeling of the coating.

Erichsen test: After the coated steel sheet was extruded by 4.5 mm using an Erichsen tester, the state of crack generation in the coating film was investigated. DuPont impact test: DuPont impact tester (height 300
mm × weight 500 g × punch diameter ½ inch), an impact test was conducted to examine the crack generation state of the coating film and the coating film peeling by the tape peeling test.

Salt Spray Test (SST): A flat plate was cross-cut at 60 °, and the swelling width of the coating film after 240 hours of the salt spray test and the peeling of the coating film and the occurrence of red rust by the tape peeling test were investigated.

Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI Technical display location C09D 1/00 PCN 163/00 PJP PKD PKK 175/04 PHX (72) Inventor Kenji Miki Kanazawa-machi, Kakogawa-shi, Hyogo No. 1 Kamigawa Steel Works, Kakogawa Works

Claims (9)

[Claims] 1. Spherical polyethylene wax particles mainly composed of a urethane resin having active hydrogen in the molecule and a resin containing 1.0 to 20% by weight of a room temperature crosslinkable epoxy resin.
0.5 to 20% by weight and chain colloidal silica to SiO ₂
The amount of resin film containing 1 to 30% by weight is 0.2
A resin-coated aluminum-based plated steel sheet having excellent press formability and coatability after processing, which is formed on the surface of the steel sheet at 3 g / m ^{2 and} holds the spherical polyethylene wax particles in a spherical shape in the film. . 2. The particle size of spherical polyethylene wax particles is
The resin-coated aluminum-based plated steel sheet according to claim 1, which has a thickness of 0.1 to 3 μm. 3. The melting point of spherical polyethylene wax particles is 1.
It is in the range of 00 to 140 ° C.
The resin-coated aluminum-based plated steel sheet described. 4. The chain colloidal silica has a length of 40 to 40.
The resin-coated aluminum-based plated steel sheet according to claim 1, which is in a range of 300 nm. 5. The resin-coated aluminum-based plated steel sheet according to claim 1, wherein the spherical polyethylene wax particles are held in a spherical shape in the film. 6. A urethane resin having active hydrogen in the molecule
Room temperature cross-linkable epoxy resin 1.0 to 20
Mainly composed of resin containing wt%, calculated as solid content
0.5-20% by weight of spherical polyethylene wax particles and chains
Colloidal silica SiO ₂As 1 to 30% by weight
The coating agent that has the
Applying to the surface, melting point of the spherical polyethylene wax particles
Dry at the following temperature and then use the spherical polyethylene wack
While maintaining the spherical particles in the resin film, the amount of adhesion is 0.2-
3 g / m²It is special to form a resin film in the range of
Resin with excellent press moldability and paintability after processing
Manufacturing method of coated aluminum-based plated steel sheet. 7. The particle size of spherical polyethylene wax particles is
It is 0.1-3 micrometers, The manufacturing method of the resin coating aluminum-type plated steel plate of Claim 6 characterized by the above-mentioned. 8. The melting point of spherical polyethylene wax particles is 1.
7. The range of 00 to 140 ° C. 7.
A method for producing a resin-coated aluminum-plated steel sheet according to the description. 9. The chain colloidal silica has a length of 40 to 40.
The method for producing a resin-coated aluminum-based plated steel sheet according to claim 6, wherein the thickness is in the range of 300 nm.