JPH068369A - Polybutylene terephthalate coated metal plate - Google Patents

Abstract

PURPOSE:To enhance the processability, scratch resistance and antistaining properties of a coated metal plate by constituting the plastic film laminated to a metal plate of modified polybutylene terephthalate. CONSTITUTION:The plastic film laminated on a metal plate is constituted of at least one kind of a compd. selected from telephthalic acid, 1,4-butane diol, dicarboxylic acid other than terephthalic acid, diol other than 1,4-butane diol and hydroxycarboxylic acid and modified polybutylene terephthalate. The plastic film is bonded to the metal plate under pressure by an adhesive to be laminated thereto. The film coated steel plate thus obtained is enhanced in finish properties, scratch resistance, antistaining properties or the like.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a polybutylene terephthalate coated metal sheet.

[0002]

2. Description of the Related Art Conventionally, a metal plate is generally coated for the purpose of imparting anticorrosion properties and cosmetic properties. However, the paints used in these paintings generally contain a large amount of organic solvents and thus generate a large amount of organic solvents during painting and baking, which is problematic from the viewpoint of environmental pollution and safety.

As a coated metal plate that does not use these paints, a laminated steel plate in which a plastic film is bonded to a steel plate via an adhesive is known. A polyethylene terephthalate film is generally used as the plastic film used in the steel sheet, but it may have cracks when subjected to advanced processing, probably because of its large crystallinity.
There was a drawback that it caused peeling. Further, it is possible to use a polybutylene terephthalate film in addition to the polyethylene terephthalate film, but this has a drawback that it is inferior in processability, transparency and slipperiness.

[0004]

As a result of various studies to solve the above problems, the present invention is excellent in workability and transparency by laminating a specific polybutylene terephthalate film on a metal plate. It has been found that a coated metal plate can be provided, and the present invention has been completed.

The modified polybutylene terephthalate film used in the present invention has terephthalic acid, 1,
At least one compound selected from dicarboxylic acids other than 4-dibutanediol and terephthalic acid, diols other than 1,4-butanediol, and hydroxycarboxylic acids (hereinafter, these compounds may be abbreviated as "modifying compounds"). .).

Examples of the modified compound include isophthalic acid, (anhydrous) phthalic acid, tetrahydro (anhydrous) phthalic acid, hexahydro (anhydrous) phthalic acid, 4-methylhexahydro (anhydrous) phthalic acid and (anhydrous) hymic acid. Dicarboxylic acids other than terephthalic acid, such as cyclic dicarboxylic acids, (anhydrous) maleic acid, (anhydrous) succinic acid, itaconic acid, sebacic acid, azelaic acid and other non-terephthalic acids; (poly) ethylene glycol, (poly)
Acyclic diols such as propylene glycol, pentanediol, neopentyl glycol, 1,6-hexanediol, 1,4-cyclohexyl glycol, 1,4
Diols other than 1,4-butanediol, such as cyclohexanedimethanol, hydrogenated bisphenol A, bisphenol A, bisphenol B, bisphenol F, hydrogenated or cyclic diols such as adducts of bisphenol and alkylene oxides; glycolic acid, oxy Examples thereof include hydroxycarboxylic acids such as propionic acid and hydroxybenzoic acid.

The composition ratio of the above modified compound in the modified polybutylene terephthalate is about 1 to 35 mol%, preferably about 5 to 25 mol%.

The modified polybutylene terephthalate has a molecular weight of about 5,000 to 1,000,000, preferably about 1,000 to 500,000.

If necessary, a thermoplastic resin may be mixed with the modified polybutylene terephthalate. Examples of the thermoplastic resin include a styrene polymer, an olefin polymer, a polyurethane resin, a polyamide resin, and a polyester resin. Of these, polyester resins are preferable. As the polyester resin, for example, the modified polybutylene terephthalate modified with the modifying compound in the range of about 5 to 75 mol%, preferably about 10 to 50 mol% is preferable.

The mixing ratio of the thermoplastic resin to the modified polybutylene terephthalate 1 is about 4 to 0.05 weight ratio, preferably about 2 to 0.1 weight ratio.

The film used in the present invention may contain a colorant, a filler, a metal powder, and other various additives in addition to the above resin components. The film thickness of the film is not particularly limited and can be appropriately selected depending on the purpose.
Usually, it is preferably about 20 to 100 μm.

The modified polybutylene terephthalate film is surface-treated (for example, corona discharge, flame, etc.),
Primers, printing etc. can be applied.

Further, a clear coat can be formed on the outer surface of the modified polybutylene terephthalate film. The clear coat is preferably a curable clear coat, more preferably an active energy ray curable clear coat. As the active energy ray-curable clear coat, a conventionally known one can be applied. Since the active energy ray-curable clear coat can be cured in a short time without heating, the modified polybutylene terephthalate does not have a risk of being deteriorated or deformed, and a clear coat excellent in finishability can be formed. There is an advantage that performances such as resistance and stain resistance (difficulty stain resistance and contaminant removability) are improved. The clear coat is usually about 1 to 20 μm,
It is preferably 5 to 10 μm.

If necessary, an anchor coat (for example, a two-component urethane clear coat), printing (for example, polyvinyl chloride screen printing) or the like can be applied to the inner surface (direction of the metal plate) of the modified polybutylene terephthalate film. .

As a method for laminating the modified polybutylene terephthalate film on a metal plate, a conventionally known laminating method can be used. Specifically, an adhesive (metal plate / heat lamination adhesive, film / heat seal adhesive) is applied to the surface of the metal plate and / or film so that the metal plate and the film are in contact with each other via the adhesive. It can be done by pressing with a roller.

Examples of the adhesive include uncured adhesives such as vinyl acetate, acrylic, ethylene-vinyl acetate, vinyl chloride-vinyl acetate, polyamide, polyurethane, synthetic rubber and natural rubber. Curing adhesives such as urea-based, melamine-based, epoxy-based, phenol-based, acrylic-based, polyester-based and urethane-based adhesives can be mentioned. The curing of the curable adhesive can be performed, for example, at room temperature or by heating, active energy rays, or the like. The film thickness of the adhesive is about 2 to 10
Good range is μm.

Examples of the metal plate include sheet-shaped and coil-shaped steel plates, copper foils and aluminum plates, or those obtained by subjecting these metal plates to surface treatment. Further, it is possible to apply a primer, print, etc. to the metal plate. The metal plate preferably has a thickness of about 0.2 to 0.5 mm.

[0018]

【Example】

Examples 1 to 3 The plastic films of types A, B and C were used. As a metal plate, a molten zinc-plated steel plate (thickness: 0.
35 mm) was coated with a thermal laminating adhesive (polyester-polyisocyanate type) at 40 mg / dm ² (solid content), and then dried at 80 ° C. for 60 seconds.

Example 4 Type A was used as the plastic film. As a metal plate, a primer (thermosetting polyester-based primer, white) is applied to a hot-dip galvanized steel plate (the same as above) to a dry film thickness of 8 to 10 μm, and a thermal laminating adhesive (same as above) is applied. Was applied and dried in the same manner as above.

Example 5 An anchor coat (two-component urethane clear) was applied to the inner surface of the plastic film A type so as to have a dry film thickness of 5 μm. The same metal plate as in Example 4 was used.

Example 6 The plastic film used in Example 5 was printed on the surface of the anchor coat of the plastic film (polyvinyl chloride ink, screen printing method). The same metal plate as in Example 5 was used.

Example 7 As a plastic film, a heat-sealing adhesive (epoxy type) was applied on the printed surface of the plastic film used in Example 6 so that the dry film thickness was 30 mg / dm ² , and then 8
What was heated at 0 ° C. for 60 seconds was used. As the metal plate, a molten zinc-plated steel plate (same as above) to which a primer (same as above) was applied and dried to a dry film thickness of 8 to 10 μm was used.

Example 8 As a plastic film, a clear coat (ultraviolet curable paint) of about 10 μm was applied to the outer surface of type A, and then a clear coat was formed by irradiating with ultraviolet rays, and then the plastic film surface opposite to the clear coat was formed. An anchor coat, a printing layer, and a heat-seal adhesive layer were formed on the (inner surface) in the same manner as in Example 7. The same metal plate as in Example 7 was used.

Comparative Example 1 In Example 4, an unmodified polybutylene terephthalate film (Duranex 500FP, trade name, manufactured by Polyplastics Co., Ltd.) was used instead of the plastic film type A.
The same thing as Example 4 was used except having used.

Comparative Example 2 The same material as in Example 4 was used except that a polyethylene terephthalate film was used instead of the plastic film type A in Example 4. The performance test results of the examples and comparative examples are summarized in Table 1.

[0026]

[Table 1]

(* 1) Plastic film type A: terephthalic acid / isophthalic acid = 87.5 / 1
Modified polybutylene terephthalate-based copolymer of 50 mol% of dicarboxylic acid and 50 mol% of 1,4-butanediol in a ratio of 2.5 (molar ratio). B: Modified polybutylene terephthalate-based copolymer of 50 mol% terephthalic acid and 50 mol% diol consisting of 1,4-butanediol / 2,2-bis (4-hydroxyethoxyphenyl) propane = 90/10 (molar ratio) Polymer. C: A-modified polybutylene terephthalate-based copolymer / nylon 12 (manufactured by Daicel Huls, Daiamide,
Trade name) = 75/25 (wt%) mixture. D: Polybutylene terephthalate copolymer. E: Polyethylene terephthalate copolymer. The film thickness of each of A to E was 30 μm.

(* 2) Laminating conditions (I): 180 ° C. 3.5 kg / cm ² (II): Metal plate 100 ° C. preheated, 180 ° C. 3.5 kg / cm ²

(* 3) Performance test Erichsen: JIS K-5400 The state of the plastic film at the extruded distance was examined. The evaluation criteria are as follows. ⊚ is good, ○ is slightly cracked, Δ is cracked, × is cracked or peeled.

Transparency: Visually examined. The evaluation criteria are as follows. ○: transparent, ×: slightly less transparent

Scratch resistance: A commercially available cleanser, about 0.5 g of which was moistened with water, was placed on a test paint plate and rubbed under the following conditions using a Gakushin-type friction fastness tester. The test was conducted. Load: 500 g Friction frequency: 20 times Temperature: 20 ± 2 ° C. Friction surface: Cover with two flannel cloths. The evaluation criteria are as follows. ⊚ shows almost no decrease in gloss as compared to the initial one, ○ indicates slightly decrease in gloss as compared to the initial one, and × indicates significantly less gloss than the initial one.

Contamination resistance: After writing lines and letters with three color oil markers of black, blue, and red, erase with a whiteboard eraser, repeat this 10,000 times at the same place, and finally with an eraser The appearance after wiping was evaluated by the following method. ◎ indicates that the marker (mud, oil, carbon powder) does not remain, ○ indicates that the marker (mud, oil, carbon powder) remains slightly, and △ indicates the marker (mud, oil, carbon powder) remains, × markedly remains after the marker (mud, oil, carbon powder))

[0033]

Industrial Applicability The coated metal sheet of the present invention is particularly excellent in workability and scratch resistance.

Claims (1)

[Claims] 1. A coated metal plate obtained by laminating a plastic film on a metal plate, wherein the plastic film is terephthalic acid, 1,4-butanediol, a dicarboxylic acid other than terephthalic acid, and a diol other than 1,4-butanediol. And a modified polybutylene terephthalate-coated metal plate comprising at least one compound selected from hydroxycarboxylic acids.