JPH06255062A - Production of decorative metal plate - Google Patents

Abstract

PURPOSE:To produce a decorative metal plate not generating the break of a decorative sheet itself even when the decorative sheet and a metal plate are bonded under heating, free from a surface defect such as a crepy defect and excellent in sharpness. CONSTITUTION:A hard resin layer 4 is formed on a thermoplastic resin sheet 3 to produce a decorative sheet. In this decorative sheet, a pattern layer or a primer layer may be inserted between the thermoplastic resin sheet 3 and the hard resin layer 4. The decorative sheet is bonded to a metal plate l under heating by a hot-melt adhesive with an adhesive temp. of 110-150 deg.C to obtain a decorative metal plate excellent in bonding properties, close adhesiveness and sharpness.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a decorative metal plate in which a decorative sheet and a metal plate are attached.

[0002]

2. Description of the Related Art Conventionally, a decorative sheet formed by forming a hard resin layer for surface protection on a thermoplastic resin sheet with or without a design such as a pattern is coated with an adhesive. A decorative metal plate was manufactured by sticking it on a metal plate while heating with a heating roller or the like. Since such a decorative metal plate is generally used for electric appliances, furniture, etc., it is required to have excellent properties in terms of designability, image clarity, surface hardness, bending characteristics, and moldability.

[0003]

In the conventional method for producing a decorative metal plate, a decorative sheet is attached onto a metal plate coated with an adhesive while heating with a heating roller or the like. To increase the adhesion of the sheet to the metal plate,
Usually, the sticking was performed by heating and pressurizing with a heating roll having a heating temperature of 180 ° C. or higher. However, at such a high temperature, the decorative sheet is easily broken by heat, and the sticking often occurs due to breakage. There were times when the work became difficult or stopped. Even in the case where breakage does not occur, in the decorative metal plate manufactured in this manner, the decorative sheet is dusty due to the difference in thermal shrinkage rate and elongation rate between the hard resin layer and the thermoplastic resin sheet due to the high temperature. Therefore, there was a problem in designability.

On the other hand, in order to prevent such defects such as breakage of the decorative sheet and generation of dusting, it is necessary to adhere the decorative sheet and the metal plate at a heating temperature of 150 ° C. or lower in the above conventional method. Although it is possible to avoid the occurrence of these defects, adhesion at such a low temperature makes the adhesive force between the decorative sheet and the metal plate at ambient temperature, and the creep resistance weak, which is desirable for the obtained decorative metal plate. Could not give the adhesive strength of.

The desired initial adhesive force and final adhesive force between the decorative sheet and the metal plate in the decorative metal plate to which the decorative sheet is attached require the following initial adhesive force and final adhesive force. That is,
As the initial adhesive force, the decorative sheet and the metal plate cannot be easily peeled off by hand, and the adhesive force is such that the vicinity of the cut surface does not peel off and rise when the decorative sheet-attached metal plate is cut and processed, It is necessary that the peel strength is 50 g / cm width or more, more preferably 100 g / cm width or more, and that the adhesion force immediately after adhesion is the adhesion force required for handling and processing the metal plate.

The final adhesive strength is such that the adhesive does not undergo creep deformation even at the maximum environmental temperature of 100 ° C. (it is desirable that the adhesive crosslinks and polymerizes into a cured product), and the decorative metal plate. The decorative sheet does not peel off even if it is bent or drawn, and the peel strength is 10
00 g / cm width or more, more preferably 2000 g / c
It is required that the adhesive force is m or more.

Therefore, the present invention eliminates the above-mentioned drawbacks of the prior art, and even when the decorative sheet and the metal plate are heat-bonded to each other, there is no surface defect such as breakage of the decorative sheet itself or generation of dusting, and sharpness. It is an object of the present invention to provide a method for producing a decorative metal plate, which is excellent in adhesiveness and in which a decorative sheet and a metal plate are bonded together with a desired adhesive force.

[0008]

In order to solve the above-mentioned problems, the present invention provides a decorative sheet in which at least a hard resin layer is formed on a thermoplastic resin sheet, and has an adhesive temperature of 11
A method for producing a decorative metal plate, which comprises heating and adhering to a metal plate through a heat-sealing adhesive having a temperature of 0 ° C. to 150 ° C. for integration.

The layer structure of the decorative sheet, the layer structure of the decorative metal plate, the metal plate, the thermoplastic resin sheet, the hard resin layer, the primer layer and the adhesive layer in the present invention will be described in detail below. Layer structure of decorative sheet: The decorative sheet used in the present invention is
It essentially consists of a thermoplastic resin sheet and a hard resin layer formed on the surface thereof, and if necessary, a pattern layer may be formed on the front surface or the back surface of the thermoplastic resin sheet.
Further, a primer may be provided between the thermoplastic resin sheet and the hard resin layer to improve the adhesiveness of both layers.

Layer structure of decorative metal plate: Cross sections of structural examples of the decorative metal plate of the present invention are shown in FIGS. FIG. 1 shows a decorative sheet having a hard resin layer formed on a thermoplastic resin sheet,
An example of a decorative metal plate obtained by adhering to a metal plate with an adhesive is shown. This decorative metal plate is composed of a metal plate 1, an adhesive layer 2, a thermoplastic resin sheet 3, and a hard resin layer 4 in this order. It is configured.

FIG. 2 shows an example of a decorative metal plate obtained by adhering a decorative sheet having a pattern layer and a hard resin layer formed on a thermoplastic resin sheet to a metal plate with an adhesive. The adhesive layer 2, the thermoplastic resin sheet 3, the pattern layer 5, and the hard resin layer 4 are arranged in this order on top. FIG. 3 shows an example of a decorative metal plate obtained by adhering a decorative sheet having a hard resin layer formed on a thermoplastic resin sheet via a primer layer to a metal plate with an adhesive. The adhesive layer 2, the thermoplastic resin sheet 3, the primer layer 6, and the hard resin layer 4 are arranged in this order.

Metal plate: An existing metal plate such as a galvanized steel plate, a galvanized steel plate whose surface is treated with chromic acid, a stainless steel plate, an aluminum plate, a carbon steel plate, a copper plate or an iron plate is used. The thickness may be several tens of μ to several tens of cm. Thermoplastic resin sheet: As the thermoplastic resin sheet used in the present invention, a thermoplastic resin sheet having excellent molding characteristics is used. The material applicable to the thermoplastic resin sheet is preferably semi-hard to soft polyvinyl chloride containing 17 to 30 parts by weight of dioctyl phthalate as a plasticizer, and other examples include polyethylene, polypropylene, polystyrene and acrylonitrile-styrene copolymer. A polymer (abbreviated as AS), an acrylonitrile-butadiene-styrene copolymer (abbreviated as ABS), a polycarbonate, an acrylic acid ester or a methacrylic acid ester polymer, or the like can be used.

The thickness of the thermoplastic resin sheet may be tens of microns to tens of cm. In particular, a vinyl chloride sheet is suitable because it is highly versatile and inexpensive. Hard resin layer: The hard resin layer is formed on the thermoplastic resin sheet for the purpose of protecting the surface, imparting gloss and imparting surface smoothness. Resins for forming the hard resin layer include ionizing radiation curable resins such as unsaturated polyester, epoxy, polyurethane, and polyfunctional urethane modified acrylate, and thermosetting resins such as two-component curable resins and one-component curable resins. Is used. The coating amount of resin for forming the hard resin layer is several μ
A few mm is desirable. When the resin used is an ionizing radiation curable resin, ionizing radiation such as ultraviolet rays or electron beams is used to cure the coating film.

Primer layer: If necessary, a resin sheet having higher hardness, breaking strength and heat distortion temperature than the thermoplastic resin sheet may be laminated between the thermoplastic resin sheet and the hard resin layer. In particular, when the decorative base sheet is a vinyl chloride sheet, it is preferable to provide a sheet of biaxially stretched polyethylene terephthalate, polycarbonate or the like as the primer layer.

Adhesive layer: Examples of the adhesive that can be used in the present invention include modified urethane resin (acrylic polyol,
Prepolymers such as polyether polyol and epoxy polyol) and unsaturated polyester resins can be used.
More specifically, for example, (i) terephthalic acid as described in JP-B-53-36860,
(Ii) one or more compounds selected from the group consisting of isophthalic acid, adipic acid, azelaic acid, sebacic acid, P-oxybenzoic acid, naphthalene-2,6-dicarboxylic acid and diphenylsulfonedicarboxylic acid, and having a terminal Reduced viscosity η sp /c=0.15 to 0.40 d in which hydroxyl group is blocked by aromatic monocarboxylic acid or its derivative
A hot melt adhesive composed of a linear polyester resin or prepolymer containing 1 / g and a melting point of 140 to 200 ° C. of a crystalline copolyester as an active ingredient, and as disclosed in JP-B-51-30898. A urethane prepolymer having isocyanate groups at both ends of the molecule and an ethylene-vinyl acetate copolymer 2 to 25% by weight
And an abithienoic acid type rosin derivative and / or terpene-
A reactive hot melt type adhesive composed of a phenol copolymer resin can be used.

A cross-linking agent such as polyvalent isocyanate is added to these adhesives as needed. Examples of the cross-linking agent include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, hexamethylene diisocyanate, and 1,5-naphthylene diisocyanate for polyol prepolymers. Etc. are added.

These adhesives have a desired adhesive strength on a decorative metal plate at an adhesive treatment temperature of 110 ° C to 150 ° C. The coating amount may be several μ to several mm.

[0018]

EXAMPLES The hard resin layer coating used in this example is
It was prepared with the following composition (unit: parts by weight). Ink A (ionizing radiation curable resin) HMDI (hexamethylene diisocyanate) 10 IPDI (isophorone diisocyanate) 10 1,6-dihexanol 5 1,4-cyclohexanemethanol 5 polycaprolactone 5 2-ethylhexyl acrylate 5 1-hydroxycyclohexyl Phenylketone 1 Ink B (thermosetting resin) Fluorine-containing urethane modified resin (manufactured by Special Colorants Co., Ltd.) Main agent 100 Curing agent 7 Catalyst 4 A decorative sheet was prepared in the following manner.

On a colored polyvinyl chloride sheet (20 parts by weight of a plasticizer) having a thickness of 0.1 mm, a grain pattern is gravure-printed with a normal gravure ink, and then the ink A is coated with a gravure roll and dried. Irradiate with ultraviolet rays and make-up sheet A-
Got 1. Next, on a colored polyvinyl chloride sheet having a thickness of 0.15 mm (20 parts by weight of a plasticizer), a stone pattern is gravure-printed with a normal gravure ink, and then the ink A is coated with a gravure roll and dried. It was irradiated with ultraviolet rays to obtain a decorative sheet A-2.

Next, on a colored polyvinyl chloride sheet having a thickness of 0.1 mm (30 parts by weight of a plasticizer), a stone pattern is gravure-printed with a normal gravure ink, and then the ink B is coated with a gravure roll. After drying, it was cured at 40 ° C. for 3 days to obtain a decorative sheet B-1. Next, a grain pattern is gravure-printed on a 0.15-mm-thick colored polybityl chloride sheet (30 parts by weight of a plasticizer) with a normal gravure ink, and then ink B is applied by a gravure roll and dried 40 It was aged at ℃ for 3 days to obtain a decorative sheet B-2.

Example 1 On a zinc-plated steel sheet having a thickness of 0.6 mm, a urethane-modified adhesive having the following composition was applied in a thickness of 3 μm. That is, the urethane-modified adhesive is Takenate T
50 parts by weight of D917 (trade name), Polystar T # 11
5 (trade name) of 42.5 parts by weight and ethylene-vinyl acetate copolymer of 7.5 parts by weight were used.

Then, the galvanized steel sheet was brought to a temperature of 130 ° C., and the decorative sheet A-1 was attached by a laminating roll heated to 130 ° C. to obtain a decorative metal plate A-1. [Example 2] As in Example 1, the decorative sheet A-
2 was attached to obtain a decorative metal plate A-2.

Example 3 The decorative sheet B-1 was attached in the same manner as in Example 1 to obtain a decorative metal plate B-1. [Embodiment 4] In the same manner as in Embodiment 1, the decorative sheet B-
2 was adhered to obtain a decorative metal plate B-2.

[Comparative Examples 1 to 8] A zinc-plated steel sheet having a thickness of 6 mm was coated with 3 μm (coating thickness) of a two-component curing adhesive,
A metal plate and a decorative sheet were attached under the conditions shown in Table 1 below to prepare decorative metal plates of Comparative Examples 1 to 8.

[0025]

[Table 1]

The results of Examples 1 to 4 and Comparative Examples 1 to 8 are shown in Table 2 below.

[0027]

[Table 2]

According to Table 2, Examples 1 to 4 of the present invention are
It can be seen that the adhesiveness, adhesiveness, and image clarity are superior to those of Comparative Examples 1 to 8. In the comparative example, when the plate temperature and the roll temperature are high, the adhesion is good, but the image clarity is insufficient, and when the plate temperature and the roll temperature are low, the adhesion is poor, and the PVC thickness is 0. It can be seen that when the thickness is 1 mm, defects are likely to occur in the sticking property, the adhesive property and the sharpness.

[0029]

According to the manufacturing method of the present invention, the temperature of 110 ° C.
By using an adhesive that has the desired adhesive strength at 150 ° C, even if the decorative sheet and the metal plate are heat-bonded, there is no surface defect such as breakage of the decorative sheet itself or generation of dusting, sticking property, and adhesiveness It is possible to obtain a decorative metal plate having excellent sharpness.

[Brief description of drawings]

FIG. 1 shows an example of a decorative metal plate obtained by adhering a decorative sheet having a hard resin layer formed on a thermoplastic resin sheet to a metal plate with an adhesive.

FIG. 2 shows an example of a decorative metal plate obtained by bonding a decorative sheet having a pattern layer and a hard resin layer formed on a thermoplastic resin sheet to a metal plate with an adhesive.

FIG. 3 shows an example of a decorative metal plate obtained by adhering a decorative sheet having a primer layer and a hard resin layer formed on a thermoplastic resin sheet to a metal plate with an adhesive.

[Explanation of symbols]

 1 Metal Plate 2 Adhesive Layer 3 Thermoplastic Resin Sheet 4 Hard Resin Layer 5 Picture Layer 6 Primer Layer

Claims (3)

[Claims] 1. A decorative sheet in which at least a hard resin layer is formed on a thermoplastic resin sheet has an adhesion temperature of 110 ° C.
A method for producing a decorative metal plate, which comprises heating and adhering to a metal plate via a heat-sealing adhesive having a temperature of up to 150 ° C to integrate them. 2. The method for producing a decorative metal plate according to claim 1, wherein the decorative sheet is a thermoplastic resin sheet on which a pattern layer is formed and a hard resin layer is further formed. 3. The method for producing a decorative metal plate according to claim 1, wherein the decorative sheet is formed by forming a primer layer on a thermoplastic resin sheet and further forming a hard resin layer on the thermoplastic resin sheet.