KR100621724B1 - Resin-coated metal sheet and manufacturing method thereof - Google Patents

Abstract

A resin coated sheet metal sheet having a resin coating obtained from an emulsion composition containing ethylene / unsaturated carboxylic acid copolymer as a main component, and the emulsion composition is a carboxyl group of ethylene / unsaturated carboxylic acid copolymer in addition to ethylene / unsaturated carboxylic acid copolymer as a main component. The amine having a boiling point of 100 ° C. or lower and the ethylene / unsaturated carboxylic acid copolymer having a boiling point of 0.2 to 0.8 moles per 1 mole and a monovalent metal compound corresponding to 0.02 to 0.4 moles per 1 mole of carboxyl group, The crosslinking agent having two or more functional groups capable of reacting with a group is composed of 1 to 20% by mass based on 100% by mass of solids of the emulsion composition, wherein the emulsion composition comprises amines and ammonia having a boiling point above 100 ° C. Does not include substantially.

This resin coated metal sheet according to the present invention is not only excellent in various properties such as paintability, lubricity, processability, earth resistance, etc., but also excellent in corrosion resistance even after alkali degreasing process, and also provides a resin coating having excellent tape peeling resistance. do.

Description

Resin-coated metal sheet and manufacturing method

(Technology)

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resinous sheet metal sheet having excellent corrosion resistance that can be suitably used for applications such as household electrical appliances and building materials.

(Background)

Background Art Conventionally, chromate treatment and phosphate treatment have been conventionally performed on surface-treated steel sheets, such as electroplated steel sheets and hot-dip galvanized steel sheets, as well as aluminum plates and stainless steel sheets, which are used for household electrical appliances and building materials. In addition to these, home appliances are widely used in various components such as acoustic devices, computer parts, and microwave floor plates. However, in recent years, the demands of the demand for these surface-treated steel sheets have been advanced day by day and various various film performances have been required.

For example, when the surface-treated steel sheet is used as it is, it is resistant to corrosion, earth- or grounding properties, anti-fingerprint properties that are difficult to see due to fingerprints, alkalis and solvents, and the like. Chemical resistance and stain resistance are required, and in the case of press processing and blank processing, lubricity, scratch resistance, deep drawing processing, mold wear resistance, punchability, blackening resistance of the processing contact surface, etc. Oil resistance to chemicals, press oils, quick-drying oils, and the like are demanded.

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In order to satisfy such requirements, for example, Japanese Patent Laid-Open No. 6-246229 discloses an organic composite coated plate having a resin film formed by neutralizing 60 to 80% of carboxyl groups in an ethylene-based ionomer with sodium ions on a chromate treatment layer. Is disclosed. In addition, Japanese Patent No. 2759620 discloses a resin coating sheet formed on a surface of a metal plate, wherein a film obtained from a composition containing a polyolefin resin copolymer emulsion and an organic compound having an aziridinyl group intermolecularly associated with ion clusters is formed. A metal plate is shown. This patent 2759620 describes that it is preferable to perform chromate treatment as a metal plate.

However, in recent years, the movement of chromium-free (non-chromated) for the preservation of the global environment has come to require higher corrosion resistance than ever before for the resin film.

As mentioned above, even in the resin film laminated | stacked on the chromium-free metal plate, since the corrosion resistance of the same grade as the resin film coated on the chromate-treated metal plate was calculated | required, this inventors etc. are consistently after filing of the said patent 2759620. The review has continued. The resin coating described in Patent No. 2759620 exhibits some excellent corrosion resistance even in the case of chromium-free. For example, after removing the lubricating oil applied during press molding by a degreasing step, the resin coating is deteriorated by alkali treatment to reduce corrosion resistance. There was. In addition, after the resin film is coated on the chromium-free metal plate, the adhesive tape is applied to the surface of the resin film, and the adhesive tape is peeled off to the resin film after leaving the adhesive tape for a long time, that is, the adhesion between the metal plate and the resin film is insufficient. There was a problem.

Accordingly, the object of the present invention is to presuppose excellent various properties such as paintability, lubricity, molding processability, earth resistance or earthing property in paintability, resin coating metal sheet, and corrosion resistance and stripping resistance after degreasing process. It is to provide a resinous sheet metal sheet having this excellent resin film.

As an example, the resin coated metal sheet of the present invention is composed of a metal sheet and a resin coating coated on the surface of the metal sheet, and the resin coating is basically obtained from an emulsion composition. In addition to the emulsion composition, a resin composition in which an additive such as silica and wax is added to an emulsion composition mainly composed of ethylene / unsaturated carboxylic acid copolymer may be used.

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In addition, the emulsion composition herein has an amine having a boiling point of 100 ° C. or lower corresponding to 0.2 to 0.8 mole relative to 1 mole of the carboxyl group of the ethylene / unsaturated carboxylic acid copolymer in addition to the ethylene / unsaturated carboxylic acid copolymer. (amine);

Monovalent metal compounds corresponding to 0.02 to 0.4 moles with respect to 1 mole of carboxyl groups of the ethylene / unsaturated carboxylic acid copolymer;

Moreover, it consists of a crosslinking agent which has 2 or more functional groups obtained by reaction with the carboxyl group contained in ethylene / unsaturated carbonic acid copolymer.

This crosslinking agent contains 1-20 mass% with respect to 100 mass% of solid content of an emulsion composition. Wherein the emulsion zone composition is characterized by substantially free of amines and ammonia above the boiling point of 100 ° C.

It is preferable that 10-40 mass% of unsaturated carboxylic acids are copolymerized, and, as for the said ethylene / unsaturated carbonic acid copolymer, it is most preferable to copolymerize 15-25 mass%. It is also preferable in the present invention that the amine having a boiling point of 100 ° C. or less is triethylamine.

The emulsion composition may contain 5-40 mass% of silica particles with an average particle diameter of 1-200 nm in 100 mass% of solid content, and it is also preferable that 0.5-20 mass% of spherical polyethylene wax is contained. As a result, various properties such as paintability, lubricity, processability, earth resistance, and the like can be provided. Furthermore, the resin film is excellent in corrosion resistance and tape peeling resistance after the degreasing step. On the other hand, the resin coated metal sheet of the present invention has good corrosion resistance even when no chromate film is formed.

As described above, the present invention is one of the characteristics of the present invention, and the ethylene / unsaturated carboxylic acid copolymer is neutralized and emulsified using an amine having a specific boiling point of 100 ° C. or less and a metal compound. This very small emulsion composition can be obtained. As a result, a resin coated metal sheet having a film excellent in coating properties, lubricity, workability, earth resistance, etc., and excellent in corrosion resistance and tape peeling resistance after the degreasing process can be obtained. The invention also provides for the preparation of emulsion compositions;

Coating of this emulsion zone composition on the metal plate;

And it is characterized by the invention that it provides the manufacturing method of the resinous sheet metal plate containing the heating and drying step of the resin metal plate coated with this emulsion zone composition.

(The best form to carry out invention)

The resin coated metal sheet of the present invention includes a resin film formed from a specific emulsion composition on at least one side of the metal plate. Although it does not specifically limit as a metal plate, For example, a zinc or zinc-type plated steel plate, an aluminum plate, an aluminium alloy plate, a titanium plate, etc. are mentioned. In addition, a known antirust treatment such as phosphate treatment and other substrate treatment may be performed on these metal plates, and a resin film may be formed thereon. In view of environmental problems, it is preferable not to perform chromate treatment.

The emulsion composition used in the present invention for the formation of a resin film is composed mainly of ethylene / unsaturated carboxylic acid copolymer (including neutralization state), and with respect to 1 mole of carboxyl groups of ethylene / unsaturated carboxylic acid copolymer. 1 equivalent to 0.02 to 0.4 mole (2 to 40 mole%) with respect to amine having a boiling point of 100 ° C. or less and 1 to 1 mole of ethylene / unsaturated carboxylic acid copolymer having an boiling point corresponding to 0.2 to 0.8 mole (20 to 80 mole%). A crosslinking agent containing two or more functional groups capable of reacting with a carboxyl group while containing a valent metal compound, contains 0.5 to 20% by mass relative to 100% by mass of the solid content of the emulsion composition. Here, amines and ammonia above the boiling point of 100 ° C. are substantially not included in the emulsion zone.

The ethylene / unsaturated carboxylic acid copolymer is a copolymer of ethylene and ethylenically unsaturated carboxylic acid. Examples of the unsaturated carboxylic acid include (meth) acrylic acid, chromic acid, isocrotonic acid, maleic acid, fumaric acid and itaconic acid. A copolymer can be obtained by superposing | polymerizing 1 or more types of these and ethylene with a well-known high temperature high pressure polymerization method. As the copolymer, a random copolymer is most preferred. However, a copolymer in which the block copolymer and the unsaturated carboxylic acid moiety are kraft-grafted may be used. Moreover, (meth) acrylic acid is suitable as unsaturated carboxylic acid. In addition, a part of ethylene may be replaced with an olefin monomer such as propylene or 1 butene, and may be used within the range not impairing the object of the present invention. Also good.

The copolymerization ratio of unsaturated carboxylic acid to ethylene is preferably 10 to 40 mass% of unsaturated carboxylic acid when the total monomer content is 100 mass%. If the unsaturated carboxylic acid is less than 10% by mass, the carboxyl group which is the starting point of the intermolecular association by the ion cluster or the crosslinking point with the crosslinking agent is small, so that the film strength effect is not exerted, and the tape peeling resistance and the corrosion resistance after the degreasing step are insufficient. It is not preferable because the emulsion stability of the emulsion composition worsens on the above. The lower limit of more preferable unsaturated carboxylic acid is 15 mass%. On the other hand, when unsaturated carboxylic acid exceeds 40 mass%, since corrosion resistance and water resistance of a resin film worsen, and corrosion resistance after a degreasing process also falls, it is unpreferable. More preferable upper limit is 25 mass%.

Since the ethylene / unsaturated carboxylic acid copolymer has a carboxyl group, it is possible to emulsify (water dispersion) by neutralizing with an organic base and a metal ion. In the present invention, an amine having a boiling point of 100 ° C. or lower is used as the organic base. Amines having a boiling point of more than 100 ° C. tend to remain on the steel sheet when the resin coating film is dried, and the water absorbency of the resin coating film increases, resulting in a decrease in corrosion resistance. Therefore, in the present invention, the emulsion composition used for film formation does not contain amines having a boiling point of more than 100 ° C. Moreover, since the addition effect of ammonia is not recognized, ammonia is not included. The boiling point applies to the boiling point under atmospheric pressure.

Specific examples of the amine having a boiling point of 100 ° C. or lower include triethylamine, N, N-dimethylbutylamine, N, N-dimethylarylamine, N-methylpyrrolidine, tetramethyldiaminomethane and trimethylamine. Tertiary amines such as; Secondary amines such as N-methylethylamine, diisopropylamine and diethylamine; Primary amines, such as propylamine, t-butylamine, sec-butylamine, isobutylamine, 1,2-dibutylpropylamine, and 3-pentylamine, etc. are mentioned, 1 type, or 2 or more types are mixed, Can be used. Among these, tertiary amines are preferred, and triethylamine is the best.

The amount of the amine having a boiling point of 100 ° C. or lower is in the range of 0.2 to 0.8 mol (20 to 80 mole%) based on 1 mol of the carboxyl group in the ethylene / unsaturated carboxylic acid copolymer. It is because corrosion resistance and tape peeling resistance are favorable in it being this range. If the amine having a boiling point of 100 ° C. or less is less than 0.2 mole, the particle size of the resin particles in the emulsion zone becomes large, and thus it is considered that the above effects are not exhibited. In addition, when an amine having a boiling point of 100 ° C. or lower in excess of 0.8 mole is used, the emulsion composition may thicken and gelize, which is not preferable. More preferably, the upper limit of the amount of the amine is 0.6 mol, more preferably 0.5 mol, and the lower limit of the amount of the amine is most preferably 0.3 mol.

In the present invention, the monovalent metal is used for temperature neutralization. Since it is effective for improving solvent resistance and film hardness, a monovalent metal compound is added to the emulsion zone composition. The monovalent metal compound preferably contains one or two or more metals selected from sodium, potassium, richium, and the like, and hydroxides, carbonates, or oxides of these metals are preferable. Among them, NaOH, KOH, LiOH and the like are preferred, and NaOH is preferred because it has the best performance. In addition, since the effect of the addition of a divalent or higher metal compound is not recognized, the emulsion composition used for forming a film in the present invention does not include a divalent or higher metal compound as a reaction partner of the ethylene / unsaturated carboxylic acid copolymer.

The amount of the monovalent metal compound is in the range of 0.02 to 0.4 mol (2 to 40 mole%) with respect to 1 mol of the carboxyl group in the ethylene / unsaturated carboxylic acid copolymer. When the amount of the metal compound is less than 0.02 mole, the emulsion stability is insufficient. However, when the amount of the metal compound exceeds 0.4 mole, the hygroscopicity (particularly with respect to the alkaline solution) of the resulting resin film increases, and the corrosion resistance after the degreasing step is deteriorated. The lower limit of the amount of the metal compound is more preferably 0.03 mol, still more preferably 0.1 mol, and the upper limit of the amount of the metal compound is more preferably 0.5 mol and most preferably 0.2 mol.

Preferred ranges of the respective amounts of the amine having a boiling point of 100 ° C. or lower and the monovalent metal compound are as described above, but they are all used to neutralize and emulsify the carboxyl groups in the ethylene / unsaturated carboxylic acid copolymer. Therefore, when these total amounts (neutralization amount) become too large, the viscosity of an emulsion zone will rise rapidly and will solidify. In addition, since an excessive alkali component causes corrosion resistance deterioration, it is not preferable. In addition, a lot of energy is required to volatilize the excess alkali component. However, if the amount of neutralization is too small, the emulsification becomes worse, too, which is also undesirable. Therefore, the total amount of the amine having a boiling point of 100 ° C. or lower and the monovalent metal compound is preferably in the range of 0.3 to 1.0 mole with respect to 1 mole of the carboxyl group in the ethylene / unsaturated carboxylic acid copolymer.

The emulsion composition used in the present invention is emulsified in combination with an amine having a boiling point of 100 ° C. or less and a monovalent metal ion, and the resin particles in the composition are in an aqueous medium in a state of extremely small fine particles (oil droplets) of 5 to 50 nm. It exists in a stable way. For this reason, it is estimated that the film-forming property of the resin film obtained, adhesiveness to a metal plate, and densification of a film are achieved and corrosion resistance and tape peeling resistance improve. As the aqueous medium, hydrophilic solvents such as alcohol and ether may be included in addition to water. On the other hand, the particle size of the resin particles in the emulsion zone can be measured by a laser diffraction method using, for example, a light scattering photometer (manufactured by Otsuka Electronics Co., Ltd.).

In the neutralization process of ethylene / unsaturated carboxylic acid copolymers with amines having a boiling point of 100 ° C. or lower and monovalent metal ions, that is, emulsification, amines having a boiling point of 100 ° C. or lower and monovalent metal compounds are added to the copolymer at about the same time or at a boiling point. It is preferable to add an amine of 100 degrees C or less first. This is because the post-addition of the amine having a boiling point of 100 ° C. or lower causes an insufficient effect of improving the corrosion resistance / tape resistance.

The ethylene / unsaturated carboxylic acid copolymer having a carboxyl group neutralized by an amine having a boiling point of 100 ° C. or less and a monovalent metal ion forms an intermolecular association by ion clustering (ionomerization), and has corrosion resistance / tape peeling resistance. Excellent resin film is formed. However, in order to form a stronger film, it is preferable to crosslink the polymer chains by chemical bonding using a reaction between functional groups. Therefore, the emulsion zone composition of this invention contains as an essential component the crosslinking agent which has 2 or more functional groups which can react with a carboxyl group. The amount shall be 1-20 mass% in 100 mass% of solid content in an emulsion zone composition. If it is less than 1 mass%, the crosslinking effect by chemical bonding becomes inadequate, and the improvement effect of corrosion resistance / tape resistance is hard to be exhibited. In addition, when the content exceeds 20% by mass, the crosslinking density of the resin film becomes excessively high, so that the hardness is increased, and thus it is not possible to follow the deformation during press working, so that cracks occur, and as a result, the corrosion resistance and paintability are reduced. Not good because More preferable crosslinking agent amount is 5-10 mass% in 100 mass% of solid content in an emulsion composition. On the other hand, as the ratio of the amount of the crosslinking agent to the ethylene / unsaturated carboxylic acid copolymer, it is preferable to appropriately change the amount of the crosslinking agent according to the amount of the carboxyl group in the copolymer, but it is usually 0.5 to 50 parts by mass (more preferred to 100 parts by mass of the copolymer). Preferably 5 to 20 parts by mass).

Although it does not specifically limit as a crosslinking agent which has two or more functional groups which can react with a carboxyl group in 1 molecule, A preferable containing example is sorbitol polyglycidyl ether, (poly) glycerol polyglycidyl ether ((poly)) glycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, trimethylolpropane polyglycidyl ether, neopentyl glycol diglycidyl ether, (poly) Polyglycidyl ethers, such as ethylene glycol diglycidyl ether, and glycidyl group-containing crosslinking agents, such as polyglycidyl amines, crosslinking agent);

4,4′-bis (ethyleneimine carbonylamino) diphenylmethane, N—N′-hexamethylene-1,6-bis (l-aziridine carboxamide), N, N′-diphenylmethane-4, Bifunctional aziridine compounds such as 4′-bis (1-aziridine carboxyamide) and toluene bisaziridine carboxyamide;

Tri-1 -aziridinyl phosphine oxide, tris [1-(2 -methyl) aziridinyl] phosphine oxide, trimethylolpropane tris, beta-aziridinyl pro Β-aziriridyl propionate, tris-2, 4, 6,-(1-aziridinyl) -1, 3, 5-triazine, and tetramethylpropane tetraaziridinyl propionate Aziridinyl group-containing crosslinking agents such as tri-or more functional aziridine compounds such as tetramethylpropane tetraaziridinyl propionate or derivatives thereof are suitable examples. One or more of these can be used. Among them, the aziridinyl group-containing crosslinking agent is preferable. Moreover, you may use together polyfunctional aziridine and monofunctional aziridine (ethyleneimine etc.).

In addition to the emulsion composition, the present invention may also manufacture a resin coating metal plate by coating a resin composition on which a resin composition is added as needed. For example, it can contain 5-40 mass% silica particle in conversion of solid content. It is effective in improving corrosion resistance, paintability, scratch resistance, and the like, and also effective in improving corrosion resistance and tape peeling resistance after degreasing. If the amount is less than 5% by mass, these effects are less likely to occur. If the content is more than 40% by mass, the silica particle ratio is excessively high, resulting in poor film forming properties, cracking of the resin film during the drying process, and deterioration in corrosion resistance. not. In addition, the silica particles act as an abrasive, increase the lubricity of the coating, lower the coefficient of friction, resulting in mold wear during processing and shorten the life of the mold. The lower limit of more preferable silica particle amount is 20 mass%, and an upper limit is 30 mass%.

In order to maximize the effect of the silica particles as described above, the average particle diameter of the silica particles is preferably in the range of 1 to 200 nm. The smaller the particle diameter of the silica particles, the better the corrosion resistance of the film. This is because the resin film can be made denser and the adhesion can be improved to further increase the corrosion resistance. From this point of view, the smaller the particle size of the silica particles, the better. However, if the particle size becomes extremely fine, the above effect is saturated, so the lower limit of the particle size is preferably 1 nm. On the other hand, when the diameter of the silica particles exceeds 200 nm, the surface of the resin film is roughened, so that a dense resin film cannot be formed. In addition, since the silica particles also act as an abrasive, it is not good to cause workability deterioration. In particular, in the case where the corrosion resistance after degreasing is important, the average particle diameter of the silica particles may be in the range of 4 to 20 nm.

Such silica particles are commonly known as colloidal silica, and in the present invention, for example, [XS], [SS], [40], [N], and [UP] of the "Snotex" series "Colloidal silica manufactured by Nippon Kagaku Church" ] Was applied.

In addition to the silica described above, the emulsion zone composition of the present invention may further contain wax in the range of 0.5 to 20% by mass in terms of solid content. The wax is effective in improving the lubricity and scratch resistance of the resin film obtained. In addition, it is preferably used because it improves deep drawing, punching resistance, mold wear resistance, blackening resistance of the sliding surface during processing, and imparts excellent workability.

When the amount of wax is less than 0.5% by mass in terms of solid content, the lubricity of the resulting resin film is insufficient, and the improvement of flaw resistance and the processability to be satisfied are not obtained. On the other hand, when it exceeds 20 mass%, the lubricity of the resin film obtained is sufficient, but the coating film adhesiveness (coating property) at the time of carrying out electrodeposition coating, powder coating, or post-coating by silk printing is inferior. Moreover, corrosion resistance and tape peeling resistance after degreasing also deteriorate. This is because the wax softens, liquefies, or blooms due to heating and temporal change in the post-coating process, so that the wax thickens at the interface between the resin film and the thick coating film and the interface between the metal plate and the resin film. It is because adhesiveness with a coating film and adhesiveness with a metal plate deteriorate. The upper limit of a more preferable wax is 10 mass%, and a more preferable upper limit is 5.0 mass%.

The wax is not particularly limited, and natural waxes, synthetic waxes or mixtures thereof can be used. Natural waxes include, for example, carnauba wax, rice wax, candelilla wax, montan type wax, and derivatives thereof, and mineral oil waxes. Microcrystalline wax, paraffin wax, and the like. In addition, derivatives given these carboxyl groups can also be used.

Synthetic waxes include polyethylene, polyethylene oxide, polypropylene, ethylene / propylene copolymer waxes, and oxidized waxes of copolymerized waxes of ethylene and other monomers. This system can be used by including various types of terpolymer type due to the change of copolymerization relative. Moreover, addition wax of maleic acid, fatty acid ester type, etc. are mentioned. In addition, waxes of fluorine type resins such as polytetrafluoroethylene, polyvinyl fluoride, polyvinylidene fluoride, and tetrafluoroethylene may also be used.

As a wax, it is preferable to select a thing with a softening point of 80-140 degreeC among the thing illustrated above. When the softening point is lower than 80 DEG C, the wax particles soften and liquefy as the mold temperature rises during press and punching. On the sliding surface of the resin coated steel sheet and the mold, the liquid depletion phenomena of the liquefied wax occurs, and the workability decreases, which is not good because the friction flaws and the mold burn are generated. In addition, blackened matter adheres to the sliding portion, which may significantly damage the appearance of the product. In addition, it was confirmed that the softening point was too low from the viewpoint of corrosion resistance and tape peeling resistance after the degreasing step.

On the other hand, when the softening point exceeded 140 ° C., the lubricity by wax was insufficient, and improvement in punchability, mold wear resistance, deep drawing property, and the like was not recognized, and the corrosion resistance after degreasing also tended to decrease slightly.

As wax, spherical polyethylene wax is most suitable, and in order to obtain the effect of spherical polyethylene wax to the maximum at this time, it is preferable that the particle diameter of a wax particle is 0.1-3 micrometers. If the particle diameter of the wax particles is smaller than 0.1 mu m, it is difficult to achieve remarkable improvement in lubricity, punchability, mold resistance and deep drawing. On the other hand, when the particle diameter of the wax particles exceeds 3 µm, it is difficult to uniformly disperse the finely divided emulsion zone composition, so that the adhesion of the resin film to the metal plate is lowered. More preferable spherical polyethylene wax has a particle diameter of 0.3 to 1.0 m.

As the above-mentioned spherical polyethylene wax, for example, "DAIJET E-17" (manufactured by Kuga Chemical Co., Ltd.) "KUE-1", "KUE-5", "KUE-8" (manufactured by Sanyo Seiko Church Co., Ltd.), `` W-100 '', `` W-200 '', `` W-300 '', `` W-400 '', `` W-500 '', `` W-640 '' of the `` Kemibaru '' series (made by Mitsui Chemicals) Commercially available products such as the W-700, the Chemipearl series (manufactured by Mitsui Chemicals, Inc.), and the Elephon E-20 (manufactured by Nika Chemical Corporation) can be used as appropriate.

The emulsion composition used in the present invention is composed of crosslinking agents such as ethylene / unsaturated carboxylic acid copolymers, amines having a boiling point of 100 ° C. or lower, monovalent metal compounds, and aziridine compounds, which are essential components, as described above. It is also possible to use a resin composition containing silica particles, wax and the like in the mullion composition. Here, it is preferable that the said ethylene / unsaturated carbonic acid copolymer adjusts the amount of an aziridine compound, silica particle, wax, etc. so that these resin components may be 50 mass% or more of solid content of an emulsion composition.

In the preparation of the emulsion composition, first, an ethylene / unsaturated carboxylic acid copolymer, which is an essential component, is added to a homogenizer device, for example, in an aqueous medium, and then heated to 70 to 250 ° C., if necessary, to an amine having a boiling point of 100 ° C. or less. And a monovalent metal compound are appropriately added in the form of an aqueous solution or the like (addition of an amine having a boiling point of 100 ° C. or lower first or an amine having a boiling point of 100 ° C. or lower and a monovalent metal compound at about the same time), followed by high shear. . Silica particles, waxes, crosslinking agents, and the like may be added at any stage. However, after the crosslinking agent is added, heat should not be applied so that the crosslinking reaction proceeds to gel.

In the emulsion composition, a diluent solvent, an anti-skinning agent, a leveling agent, an antifoaming agent, a penetrant, an emulsifier, a film forming aid, Colored pigments, thickeners, silane coupling agents, other resins, and the like may be suitably added.

In forming the resin film on the metal plate, the emulsion composition is applied to one or both surfaces of the surface of the metal plate by a known coating method, that is, a roll coater method, a spray method, a curtain flow coater method, or the like, followed by heat drying. do. The heat drying temperature is preferably performed at a temperature at which the crosslinking reaction between the crosslinking agent used and the carboxyl group proceeds.

In addition, when using spherical polyethylene wax as a lubricating agent, it is preferable to carry out drying in the range of 70-130 degreeC, since the spherical polyethylene wax becomes more workable in a later processing process.

The deposition amount (thickness) of the resin coating is preferably 0.2 to 2.5 g / m 2 after drying. If it is too thin, it is difficult to uniformly coat the metal plate, and it is difficult to obtain a coating property having a balanced purpose such as workability, corrosion resistance, and paintability. However, if the deposition amount exceeds 2.5 g / m 2, it is not preferable because the earth resistance, that is, the conductivity when used in a computer housing or the like decreases. In addition, since the amount of peeling of the resin film during press working increases, adhesion accumulation of the peeling film on the mold occurs, and it is not preferable in terms of manufacturing cost, because it causes problems in press molding. The lower limit of the better resin coating amount is 0.5 g / m 2, and the upper limit is 2.0 g / m 2.

By forming the resin film, the resinous sheet metal sheet of the present invention is obtained. The resin coated metal sheet may be used as it is after the processing step depending on the application, or may be electrodeposition coated / powder coated / silk printing (130 to 160 ° C. for about 20 to 30 minutes) under conventional conditions.

(Example)

Hereinafter, the present invention will be described in detail with reference to Examples. However, the following examples are not intended to limit the present invention, and all modifications within the scope not departing from the gist of the present invention are included in the present invention.

Test Methods

The test method used in the following example was as follows.

(1) Corrosion resistance after degreasing process

20 g / l of alkaline degreasing agent (CL-N 364S) prepared by Nippon Parkarizing Co., Ltd., prepared at 60 ° C, was immersed for 2 minutes, pulled up, washed with water, dried, and the salt spray test was conducted by TIS Z2371. The time until this 1% occurrence was measured. Evaluation criteria were (circle): 240 hours or more, (circle): 120-240 hours or less, (triangle | delta): less than 72-120 hours, and x: less than 72 hours.

(2) tape peeling resistance

Adhesive tape (filament tape No.9510 manufactured by Slieon Tech Co., Ltd .; rubber-based adhesive agent) was attached to the resin coated steel sheet, and stored at 40 ° C and 98% RH in a constant temperature and humidity device for 24 hours, and then peeled off according to JIS K 5400. And the residual area ratio of the film was measured. Evaluation criteria were as follows: ◎: film remaining rate 100%, ○: film remaining rate 90-99%, △: film remaining rate 89-70%, ×: film remaining rate 70% or less.

(3) Coefficient of dynamic friction

In order to evaluate the lubricity of the resin-coated steel sheet, the friction coefficient was calculated by using the sliding test apparatus to measure the sliding load when the pressing force was 5.4 MPa and the drawing speed was 300 mm / min.

Example 1 (Influence of Type and Amount of Organic Base and Metal Salt)

As the metal sheet material, an electrogalvanized steel sheet (Zn deposition amount of 20 g / m 2, plate thickness 0.8 mm) was used.

In order to prepare the emulsion composition, 626 parts by mass of water (hereinafter, simply referred to as "parts") and 160 parts of ethylene-acrylic acid copolymer (20% by mass of acrylic acid, melt intex (MI) 300) were added to the autoclave, Furthermore, the organic base and the metal compound of the quantity shown in Table 1 were added, and it stirred at 150 degreeC and 5 Pa atmosphere at high speed, and obtained the emulsion zone of ethylene / acrylic acid copolymer. Subsequently, 5 masses of 4, 4'-bis (ethyleneiminocarbonylamino) and diphenylmethane (chemite DZ-22E; Chemitite manufactured by Nippon Shokubai Co., Ltd.) as solids were added to the emulsion zone. % (Value when the solid content of an emulsion composition is 100 mass%: the same or less) was added.

In the case of not the emulsion composition step, that is, the external crosslinking agent which reacts upon heating and drying after applying the emulsion composition to the surface of the steel sheet may need to be polymerized by crosslinking the base resin in order to obtain a desired coating performance. Sometimes used. In this embodiment, 5 mass% of the glycidyl group-containing compound (Ebiclone CR5L: abbreviated as "CR5L", "Epiclon" is registered trademark: Dainippon Ink, Inc.) as an external crosslinking agent. 30 mass% of silica particles (Snowtex 40; manufactured by Nissan Chemical Industries, Ltd.) with a particle diameter and 10-20 nm of solid polyethylene wax with a solid content of 30 mass%, a softening point of 120 DEG C and an average particle diameter of 1 μm were mixed and stirred to obtain 5 mass% as a solid content. The mixture was formulated.

Each composition was coated on one side of the galvanized steel sheet with a bar coater, dried by heating at a plate temperature of 90 ° C. for 1 minute to obtain a resin coated steel sheet having a resin coating having an adhesion amount of 1.0 g / m 2. Each evaluation result is shown in Table 1.

Example 2 (Influence of Crosslinking Agent)

Each resin coated steel sheet was obtained in the same manner as in Example 1. However, the use amount of triethylamine was kept constant at 40%, the NaOH use amount was set at 15%, and the amount of the "chemite DZ-22E" (DZ-22E) was changed as shown in Table 2 except that In the same manner, a resin coated steel sheet was obtained and characterized. The results are shown in Table 2.

Example 3 (Influence of Silica Particles)

The amount of the crosslinking agent was changed in the same manner as in Example 1, except that the particle size and the concentration of the silica particles were changed as in Table 3. It was.

Example 4 (Influence of Wax)

The particle size and the addition concentration of the silica particles were the same as in Example 1, except that the particle diameter, the addition concentration, and the softening temperature of the spherical polyethylene wax were changed as shown in Table 4, and then the resin coated steel sheet was obtained and characterized. The results are shown in Table 4.

Although the present invention has been described in the above-described embodiments, it is possible for those skilled in the art to variously change these embodiments, but such intentional changes are within the scope of the present invention and claims. It's nothing more than a change.

As described above of the present invention, one of the present invention is a mixture of an amine having a specific boiling point of 100 ° C. or less and a metal compound and emulsified by neutralizing an ethylene / unsaturated carboxylic acid copolymer. It is possible to obtain a mullion composition, and thus, a resin coated metal sheet having a film having excellent coating properties, lubricity, processability, earth resistance, and corrosion resistance and tape peeling resistance after a degreasing process can be obtained, and the present invention. Silver is also prepared in the emulsion composition;

Coating of this emulsion zone composition on the metal plate;

And it is characterized in that it provides a practical and very effective method for producing a resinous sheet metal sheet excellent in the above-described corrosion resistance, tape peeling resistance and the like, including the heating and drying step of the resin metal plate coated with the emulsion composition.

Claims (9)

A metal sheet; In the resin coated metal sheet composed of a resin film obtained by coating with an emulsion composition on the surface of the metal sheet, The emulsion composition, Ethylene / unsaturated carbonic acid copolymer which makes a main component of this composition; An amine having an boiling point of 100 ° C. or less, corresponding to 0.2 to 0.8 mole per mole of carboxyl groups contained in the ethylene / unsaturated carboxylic acid copolymer; An amount of a monovalent metal compound corresponding to 0.02 to 0.4 moles per mole of carboxyl group contained in the ethylene / unsaturated carboxylic acid copolymer; It consists of a crosslinking agent which has 2 or more functional groups which can react with the carboxyl group contained in the ethylene / unsaturated carboxylic acid copolymer, and is added in an amount of 1 to 20% by mass based on 100% by mass of the solid content of the emulsion composition. Here, the emulsion zone composition is a resin-coated metal sheet (A resin-coated metal sheet), characterized in that substantially free of ammonia and amines having a boiling point of more than 100 ℃. The resin sheet metal sheet of claim 1, wherein the ethylene / unsaturated carboxylic acid copolymer is copolymerized with 10 to 40 mass% of unsaturated carboxylic acid. The resin sheet metal plate of claim 1, wherein the amine is triethylamine having a boiling point of 100 ° C. or lower. The resin-laminated sheet metal sheet according to claim 1, wherein 5 to 40 mass% of silica particles having an average particle diameter of 1 to 200 nm are contained in 100 mass% of the solid content of the emulsion composition. The resin-laminated sheet metal sheet according to claim 1, wherein 0.5 to 20 mass% of spherical polyethylene wax is contained in 100 mass% of solid content of the emulsion composition. The resinous metal sheet as claimed in claim 1, wherein no chromate film is formed on the metal plate. The resin coating metal plate of claim 1 Preparing an emulsion composition; Painting the emulsion composition on the metal plate; A method for manufacturing the resin-coated metal sheet, comprising a step of heating and drying the metal plate coated with the emulsion composition to be manufactured. 8. The method for producing a resinous sheet metal sheet according to claim 7, wherein the heating and drying step is performed at a temperature to enable a reaction between the carboxyl group and the crosslinking agent contained in the ethylene / unsaturated carboxylic acid copolymer. 8. The method according to claim 7, wherein the emulsion zone composition is coated in such a manner that the resin coating in the coating step is coated with an amount of 0.2 to 2.5 g / m 2 of the resin coating after the heating and drying step.