WO2000031167A1

WO2000031167A1 - Covering resin film for decorative metal plate and decorative metal plate having the same

Info

Publication number: WO2000031167A1
Application number: PCT/JP1999/006581
Authority: WO
Inventors: Hiroyuki Iwashita; Koji Taguma; Yoshiyuki Sugimoto
Original assignee: Toyo Kohan Co., Ltd.
Priority date: 1998-11-25
Filing date: 1999-11-25
Publication date: 2000-06-02
Also published as: JP3693920B2; TW495526B; AU1409600A

Abstract

A covering film for a decorative metal plate which comprises a polybutylene terephthalate resin having an intrinsic viscosity of 1.0 to 2.0 and has at least one surface finished with embossing; and a decorative metal plate comprising a metal plate and, laminated thereon, the covering film for a decorative metal plate. The covering film for a decorative metal plate has the same or better processabilities in embossing and in molding as compared to those of a conventional poly(vinyl chloride) resin and is excellent in resistance to the treatment with water for a long period of time.

Description

W 0/31167

1

Description Resin film for coating decorative metal plate and decorative metal plate coated with the resin film

IT technology field

The present invention relates to a resin film for coating a decorative metal plate made of polybutylene terephthalate resin having an uneven pattern formed on the surface by embossing or the like, and a decorative metal plate coated with the resin film.

1 0 Background technology

Decorative metal sheets made by coating a metal sheet with a thermoplastic resin with excellent moldability, design properties, chemical resistance, etc. are used for building materials, furniture, electrical and electronic equipment, audio equipment, office equipment, etc. It is widely used in parts and other applications requiring water resistance, such as unit baths. In these cases, the main purpose of coating the metal plate with a thermoplastic resin is to impart an anticorrosion effect to the metal plate of the material i, but at the same time, embossing is performed to give the decorative metal plate a high-grade appearance. Conventionally, processing has been performed to form an uneven pattern on the surface. The thermoplastic resin film to be embossed used for such a purpose includes polyvinyl chloride resin, polyolefin resin such as polyethylene and polypropylene, etc. from the viewpoint of easy processing and low cost. Films made of plastic acrylic resin, fluorine-containing fluorine resin, etc., and biaxially stretched films of polyester resin have been widely used.

However, although polyvinyl chloride resin is excellent in economics, embossability, moldability, etc., it contains a plasticizer such as dibutyl phthalate / dioctyl phthalate to facilitate the molding process. This causes the plasticizer to bleed on the surface and generates hydrogen chloride gas during combustion, which has a negative impact on the environment. Problems.

For this reason, polyvinyl chloride resin and the like without the addition of a plasticizer are being studied, but the resin without the addition of a plasticizer is hard and difficult to emboss. Polyolefin resins such as polyethylene and polypropylene are being studied as alternatives to polyvinyl chloride resin. These resins have good embossing properties, but are coated on a metal plate and molded. When processed, the processed part is whitened and the design is impaired.Therefore, a method of adding a rubber component to soften the resin may be considered, but a soft resin similar to polyvinyl chloride resin with a plasticizer added is also considered. Become.

Although thermoplastic acrylic resin and fluororesin each have characteristic characteristics, they are soft resins at the same level as plasticized polyvinyl chloride resin. In recent years, attention has been focused on biaxially stretched polyester films made of a resin containing polyethylene terephthalate as the main component of the laminating material, but it is difficult to obtain a deep and clear uneven pattern when embossing is applied. Is poor, and if the resin is aged for a long time in a high-temperature and high-humidity atmosphere, the film will deteriorate due to the progress of crystallization and hydrolysis of the resin. Application to film is difficult.

An object of the present invention is to provide a resin film for coating a decorative metal plate excellent in embossability, moldability, and water aging resistance equal to or higher than that of a conventional polyvinyl chloride resin with the object of solving the above problems. Provide a decorative metal plate coated with the resin film

> 0. Disclosure of the invention

The resin film for coating a decorative metal sheet of the present invention is characterized in that the polybutylene terephthalate resin has an intrinsic viscosity (IV value) of 1.0 to 2.0.

^ It is preferable that at least one surface of the polybutylene terephthalate resin film is embossed. It is desirable to have a printed layer on the surface opposite to the embossed surface of the polybutylene terephthalate resin film.

Further, the decorative metal sheet of the present invention is characterized in that the above-mentioned resin film for coating a decorative metal sheet is coated such that the outermost surface is an embossed surface.

BEST MODE FOR CARRYING OUT THE INVENTION

The inventors of the present invention have conducted intensive studies on the relationship between the properties of the resin film and the embossability, and as a result, when a film made of polybutylene terephthalate resin having an intrinsic viscosity in a certain range is used, the embossing is performed. It has been found that a deep and clear uneven pattern is obtained, and that when this resin film is coated on a metal plate, a decorative metal plate having excellent design properties can be obtained.

As a result, even when a resin-coated metal plate obtained by laminating a resin film on a metal plate is formed, the processed portion is whitened and the design is not impaired, and the embossment is comparable to that of the polyvinyl chloride resin. The processability was obtained, and the excellent properties of polybutylene terephthalate resin having excellent water aging resistance could be maintained as it is. Hereinafter, the contents of the present invention will be described.

(Used metal plate)

As the metal plate used for the decorative metal plate of the present invention, any metal plate such as a steel plate, an aluminum plate, an aluminum alloy plate, a copper plate, and a copper alloy plate can be used. As the steel sheet, a cold rolled ordinary steel sheet having a thickness of 0.10 to 1.2 mm is preferable. Above all, a cold rolled steel sheet of ordinary steel having a thickness of 0.10 to 0.50 mm is preferable. Among the cold-rolled steel sheets, low-carbon or ultra-low-carbon aluminum-killed steel sheets are preferably used. Non-ageing steels to which Nb, Ti, etc. are added, chromium-containing steel sheets containing 3 to 18% by weight of chromium, Stainless steel plates having various compositions can also be used. Surface-treated steel sheets obtained by performing surface treatment on the surface of these cold-rolled steel sheets can also be used. The surface treatment includes plating, chemical conversion treatment and painting treatment, and the plating includes, for example, zinc plating, Lead-aluminum alloy plating, zinc-cobalt-molybdenum plating, tin plating, nickel plating, chrome plating, nickel-phosphorous plating, nickel-zinc plating, nickel-cobalt plating, nickel-tin plating, aluminum plating The chemical conversion treatment may be a known treatment such as a chromate treatment or a phosphate treatment. The X-ray coating treatment may be carried out by applying various paints according to their properties and baking.

(Used resin film, etc.)

As the resin film for coating the decorative metal plate of the present invention, a polybutylene terephthalate resin film can be suitably used. From the viewpoint of embossability,

An unstretched film is preferable to a 10-stretched film. The intrinsic viscosity of the polybutylene terephthalate resin is preferably in the range of 1.0 to 2.0. The resin is dissolved in a 1: 1 mixed solution of phenol-Z-tetrachloroethane using a standard method, and then the specific viscosity is measured with a Ubbelohde viscometer in a constant temperature bath at 30 ° C. You can ask.

\\ When the intrinsic viscosity is less than 1.0, sufficient impact resistance (water resistance) cannot be obtained when coated on a metal plate and stored for a long time in a constant temperature and high humidity atmosphere. If it exceeds 2.0, the resin is heated and melted, extruded from the extruder and formed into a film, and becomes too high in viscosity to increase the torque of the extruder, making film formation difficult. A more preferable range of the intrinsic viscosity is from 1.2 to 1.5 from the viewpoints of resistance to water deterioration and film formation. C The thickness of the polybutylene terephthalate resin film is not particularly limited, but is preferably 20 to 300 / zm, and more preferably 70 to 200 im. A resin obtained by blending the above polybutylene terephthalate resin with a polyethylene terephthalate resin, a polycarbonate resin, an ionomer resin, or a resin obtained by blending two or more of these blended resins. Copolymers with other polyester resins, such as copolymers in which part of terephthalic acid is replaced with isophthalic acid / adipic acid, and / or It is also possible to use a film made of a resin consisting of a copolymer in which part of the polyester is replaced by ethylene dalicol or the like. Further, a composite resin film obtained by laminating two or more kinds of films composed of the above various resins can also be used.

Further, for coating a decorative metal plate of the present invention

! Γ Use evening rate resin film as a single layer

—A resin film may be used as a multilayer resin film in which at least one of an adhesive layer, a coloring layer, and a printing layer is laminated on a surface opposite to a surface to be embossed as described later. For those requiring a high degree of adhesion to a metal plate, a low-melting polyester resin film other than polybutylene terephthalate resin may be used as the adhesive layer.

For example, an adhesive layer made of a general adhesive such as polyester resin and urethane resin may be provided. As the coloring layer, a film made of the same polybutylene terephthalate resin as the above-mentioned polybutylene terephthalate resin or a composite resin film obtained by laminating a coloring film obtained by adding a pigment to another polyester resin film can be used. is there.

The iir polybutylene terephthalate resin film produces fine crystals, so that a hard and smooth surface is easily obtained and has excellent printability. For this reason, a composite resin film with a gravure, offset, screen printing, or other full-color printing layer or a partially-coloring printing layer on the surface opposite to the surface on which the embossing process described below is applied, is also used. It is possible.

_{> 0 In} addition, a surface protective layer may be provided on the surface of the polybutylene terephthalate resin film to be embossed as described below to provide lubricity and abrasion resistance to such an extent that unevenness due to embossing is not lost. No problem.

(Embossing method)

As the embossing method for the above polybutylene terephthalate resin film, a method in which a heat-melted resin is extruded from a T-die onto an embossed casting port to form a film having an embossed surface on one side. , Film straight A method of passing a film between chilled rolls, a method of heating a film and passing it between chilled rolls, a method of embossing with a vacuum suction through a rotating screen roll, and a film punching machine The embossing may be performed by any method, such as a hot needle process of passing through, or a method of compressing using a stamping roll. In addition, after laminating the above polybutylene terephthalate resin film on a metal plate, the metal plate heated to the temperature range of the melting point of the resin ± 1 o ° c is pressed and embossed using an engraving roll. May be.

As the embossed shape, various patterns such as random mat, square, diamond, deep drawing, and grain (referred to as SG grain) can be selected according to the needs of the product.

(Lamination method)

The polybutylene terephthalate resin film embossed as described above is laminated on a metal plate by using a known heat fusion method or the like. That is, the metal plate is heated to a temperature equal to or higher than the melting point of the polybutylene terephthalate resin,

1 ^ The non-embossed surface of the resin film is brought into contact with the metal plate, sandwiched between a pair of laminators, immediately immersed in water and quenched.

For those requiring a high degree of adhesion to the metal plate, as described above, an adhesive layer is provided on polybutylene terephthalate resin, or an adhesive layer is provided on the metal plate, and the adhesive layer is interposed. It is also possible to laminate a metal plate and a polybutylene terephthalate resin film.

(Judgment of quality of embossability)

The embossability of the polybutylene terephthalate resin film of the present invention is determined by the surface roughness of the embossed resin film. In the present invention, the surface of the resin film was visually observed, and the quality of the embossability was evaluated based on the following 3 ^ scale.

〇: good, △: slightly bad, X: bad The above evaluation criteria are as follows: The surface average roughness (Ra: tm) of the poly (vinyl chloride) resin film is measured in accordance with JISB 0601 using a SURF COM surface roughness meter manufactured by Tokyo Seimitsu Co., Ltd. Is 4 m when the embossability is acceptable, and if the average surface roughness is equal to or more than that of the surface of a 4 m polyvinyl chloride resin film, the appearance is better (〇). Those having an appearance that is slightly inferior to the surface of the resin film but have no practical problem were judged as poor (△), and those without embossing were judged as defective (X).

(Evaluation of workability)

Embossed by passing through a SG-shaped engraving roll with a surface roughness of Ra = 11 1 at a constant speed of 0 ° and embossing, a thickness of 0.10mm with a certain length and width The polybutylene terephthalate resin film is heated to a temperature equal to or higher than the melting point of the polybutylene terephthalate resin, and has the same length and width as the polybutylene terephthalate resin film. A test piece was brought into contact with a 50 mm zinc-plated steel sheet, sandwiched between a pair of rolls, and pressed. The impact workability of the test piece obtained in this way was measured using a Dupont impact tester specified in JISK 5400, with an outer diameter of the impact part of 0.5 inch, a weight of lkg, and a drop height of 50 cm. Tested under conditions. Evaluation was performed in three stages by visual observation as described below.

〇: No crack is observed in the resin film,

Δ: Fine cracks are observed in part of the resin film,

, ₀ X: The entire resin film is significantly cracked.

In the above scores, 〇 and △ have no problem in use. This test was performed on 10 test pieces.

(Evaluation of resistance to water deterioration)

Assuming a case where the polybutylene terephthalate resin film of the present invention is subjected to embossing for a long time in a state of constant temperature and humidity (for example, when used as an interior material of a unit bath), Water resistance degradation of resin film when exposed to water for a long time The properties were evaluated by the DuPont impact test method.

Embossed by passing through an SG engraving roll provided with irregularities of surface average roughness Ra = 11 xm at a constant speed and having a thickness of 0.10 mm with a fixed length and width A polybutylene terephthalate resin film is heated to a temperature equal to or higher than the melting point of the polybutylene terephthalate resin, and has a thickness of 0.50 mm and the same length and width as the polybutylene terephthalate resin film. The test piece was brought into contact with a steel plate, and both were sandwiched between a pair of rolls and pressed to form a test piece. The test piece obtained in this way was cut into a size of 6 OmmX 60 mm, immersed in ion-exchanged water maintained at a temperature of 38 ± 2 ° C for one month, dried at room temperature, and subjected to a DuPont impact test. The impact was applied using the machine IP under the conditions compliant with JISK 5400 (outer diameter of impact part 0.5 inch, weight 1 kg, drop height 5 O cm). The state of the resin film after applying the impact was visually observed and evaluated according to the following five levels.

5: No crack is observed in the resin film.

4: Fine cracks are observed in a part of the resin film.

\ 3: Fine cracks are observed throughout the embossed portion of the resin film.

2: A large crack is observed in the entire embossed portion of the resin film. 1: The entire resin film is significantly cracked.

In the above ratings, 5 and 4 have no problem in use. This test was performed on 10 test pieces.

0 (Example)

Hereinafter, the present invention will be described in more detail with reference to Examples. An unstretched film having a thickness of 0.10 mm was prepared from polybutylene terephthalate resin having an intrinsic viscosity shown in Table 1 using an extruder. When forming these resin films, the resin film was heated and melted, and the resin melted and heated on a casting roll engraved with SG eyes having irregularities with a surface average roughness of Ra = l 1 zm was melted. The resin film was extruded and embossed on one side of the resin film. Embossed for one piece of film The entire surface was subjected to colored printing by gravure printing on the surface opposite to the processed surface. As a comparative example, a polyethylene terephthalate resin having an intrinsic viscosity shown in Table 1 was extruded using an extruder to form a film in the same manner as the above polybutylene terephthalate resin, and embossed on one side. An unstretched film having a thickness of mm was prepared. The quality of the embossability of the resin film thus obtained was evaluated by visual observation. Table 2 shows the evaluation results.

Next, the embossed resin film was laminated on a metal plate in the following manner. A 0.5-mm-thick low-carbon aluminum-killed cold-rolled steel sheet was coated with zinc to a thickness of 0.02 mm. This zinc-plated steel sheet is heated to 240 ° C, and one side of the sheet is contacted with the non-embossed surface of a poly (if-butylene terephthalate) resin film. Immediately after this, it was immersed in water and quenched. In the case of a film that has been printed on one side, apply a urethane resin-based adhesive on the printed side, dry it, and then contact the adhesive-applied surface with the heated zinc-coated steel sheet, as described above. And laminated. Thus, a zinc-coated steel sheet coated with a polybutylene terephthalate resin film was obtained. The same zinc-plated steel plate as above

Heat to 280 ° C, contact one side of the non-embossed surface of polyethylene terephthalate resin film, sandwich the two with a pair of laminating rolls, press them together, and immediately put them in water Crushed and quenched. Thus, a zinc-coated steel sheet coated with a polyethylene terephthalate resin film was obtained.

> 0 The polybutylene terephthalate resin film-coated zinc-coated steel sheet and polyethylene terephthalate resin film-coated zinc-coated steel sheet obtained as described above were subjected to a DuPont impact test under conditions in accordance with JISK540. The processability of the resin film was evaluated using a machine. Table 2 shows the evaluation results.

In addition, from each resin film-coated zinc-coated steel sheet, 6 Omm X 6 Omm

> if Specimens were cut out, immersed in ion-exchanged water kept at a temperature of 38 ± 2 ° C for one month, dried at room temperature, and then duped under the conditions in accordance with JISK540. The workability of the resin film was evaluated using a Bonn impact tester. Table 1 below shows resin films of Examples of the present invention and Comparative Examples. The evaluation results are shown in Table 2 below.

(table 1 )

(Table 2)

Note) PBT *

PET * Table 2 shows the evaluation results.

Zinc-coated steel sheet covered with a film made of resin

Compared to zinc-coated steel sheet coated with a film made of a coating resin, it shows the same or better characteristics in embossability, additivity, and water deterioration resistance. In addition, the zinc-coated steel sheet coated with the printed film provides a beautiful three-dimensional effect due to the thickness of the embossed transparent film, in addition to the beautiful color tone of the printed layer, and is excellent in design. Industrial availability

In the present invention, the polybutylene terephthalate resin has an intrinsic viscosity (IV value) of 1.0 to 2.0.

(D 0, at least one surface of which is embossed, and a resin film for coating a decorative metal plate having a printed layer on the surface opposite to the embossed surface, and a decorative film coated with the polyethylene terephthalate resin film The decorative metal plate, which is a metal plate and coated with the polybutylene terephthalate resin film of the present invention, does not lose its design even when formed, and its design is not impaired.

\ f degree embossability, and the excellent characteristics of polybutylene terephthalate resin with excellent water aging resistance can be maintained as it is, and the resin film has excellent workability and water deterioration resistance. It is applicable to building materials that require water resistance, such as unit baths.

Claims

The scope of the claims

A resin film for coating a decorative metal sheet with an intrinsic viscosity (IV value) of 1.0 to 2.0.

The resin film for coating a decorative metal sheet according to claim 1, wherein at least one surface of the polybutylene terephthalate resin film is embossed. 3. The resin film for coating a decorative metal sheet according to claim 2, wherein a printed layer is provided on a surface of the polybutylene terephthalate resin film opposite to an embossed surface. 4. A decorative metal plate coated with the resin film for coating a decorative metal plate according to any one of claims 1 to 3 such that the outermost surface is an embossed surface.