JPH04146128A - Resin laminate having curved face - Google Patents

Abstract

PURPOSE:To dispense with a welding process for the sake of providing a better appearance and improve corrosive resistance by processing a metal sheet in which at least one face is laminated with a fluorine-containing resin type film in the shape of a curved face. CONSTITUTION:A fluorine resin type film comprising a thermoplastic resin containing fluorine atoms in the molecular structural formula thereof is joined with at least one face of a metal sheet of iron or aluminum type or the like according to a method for melt adhesion under heating or the like. Next, the so obtained laminate comprising the metal and fluorine-containing resin type film is caused to have a curved face, for example by severing the laminate in a pre-determined shape and notching a side thereof to be curved in a properly pre-determined breadth and depth. Then, the notched laminate is curved, processed and molded into a core-box. Thereafter, the core-box is subjected to a curving process little by little and notch by notch until the final curved face is finished. The resin laminate having the so obtained curved face is free of damages in the film, exhibiting the properties of the fluorine plastic film and providing an excellent appearance.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a resin laminate having a novel curved surface. This invention relates to a resin laminate processed into a shape. Examples of specific uses include building corners, protruding corners, 3-degree corners, recesses, columns, etc., as well as housings for electrical parts, appliances, and general industrial equipment, desks, and lockers. Administrative functions such as

[Prior art]

Traditionally, fluorine film laminated metal sheets have been widely used in various construction materials, vehicle components, electrical products, household goods, etc. due to their excellent weather resistance, corrosion resistance, chemical resistance, stain resistance, designability, and workability. has been used. However, when used for healing purposes as described in the previous section, conventional processing methods such as simple bending and drawing cannot produce a curved panel with a flange as shown in Figure 1, or a curved panel with a flange as shown in Figure 2. When making panels with raised parts added, a process as shown in Figure 3 was necessary.

In other words, one flat plate is cut into parts as shown in Figure 3-(B), then folded as shown in Figure 3-(C), and then the flange part is cut as shown in Figure 3-(D). Finally, the rising part was welded as shown in Figure 3-(E).

In this method, first of all, a welding step is indispensable, which results in a large number of steps. Second, even when welding is performed not only in the case of double-sided fluorine film laminations, but also from the back side of the fluorine film laminated side as in this example, the laminated fluororesin films may melt or burn due to the heat during welding. Not only will this result in a poor appearance, but the characteristics of the fluororesin will also be lost. Thirdly, the cross section is shown in Figure 4, but since the cut end metal is directly exposed on the surface, it is not only not desirable from a design perspective, but also has functional problems such as corrosion, and repair is essential. However, for this repair, it is best to laminate films of the same quality, but it is impossible to apply only to the edges, and the best way is to apply fluororesin paint, which not only improves the appearance but also the surface of the film laminate. The properties did not match and caused various problems.

[Problems to be solved by the present invention]

The purpose of the present invention is to solve the above-mentioned problems that the prior art had, and to provide a fluororesin film laminated metal plate having a novel curved shape that was completely unknown in the past. be.

[Means for solving problems]

The present invention was made to solve the above-mentioned problems, and provides a novel resin laminate, which is characterized in that a metal plate with a fluorine-containing resin film laminated on at least one side is processed into a curved shape. This is what we provide. The configuration of the present invention will be explained in more detail below.

The "fluorine-containing resin" used in the present invention is not particularly regulated as long as it is a thermoplastic resin containing a fluorine atom in the molecular structure of the resin. Tetrafluoroethylene resins having 4 fluorine atoms in the formula, trifluoroethylene resins, difluoroethylene resins, -fluoroethylene resins, copolymers of these resins, and even mixtures Among these, tetrafluoroethylene resins and difluoroethylene resins are preferred, and tetrafluoroethylene resins are more preferred. Here, the tetrafluoroethylene resin specifically refers to, for example, tetrafluoroethylene resin (PTFE), tetrafluoroethylene/perfluoroalkoxyethylene copolymer (PFA),
), tetrafluoroethylene/hexafluoropropylene/perfluoroalkoxyethylene copolymer (EPE), and tetrafluoroethylene/ethylene copolymer (ETFE), etc.
Among them, PFASETFE is preferred, and PFA is particularly preferred. Further, the trifluoroethylene resin mentioned above specifically refers to, for example, trifluorochloride ethylene resin (PCTFE).
) and trifluorochloroethylene/ethylene copolymer (E
CTFE), among which PCTFE is preferred. Specifically, the difluoroethylene-based and -fluoroethylene-based resins include, for example, vinylidene fluoride resin (P
VDF) and vinyl fluoride resin (PVC).

In addition, it goes without saying that the fluorine-containing resin film used for one side of the present invention must be free from damage such as pinholes, and as long as it completely covers the metal plate serving as the substrate. Although the film thickness may be any value, it is generally 5 to 200μ, preferably 20 to 100μ.

These fluororesin films can be produced by conventional methods, such as hot melt extrusion, casting, etc., and if necessary, pigments, It is possible to add dyes for coloring, or add inorganic fillers such as glass powder, glass beads, glass fibers, aluminum oxide, talc, mica, silica, etc. to improve the strength. It is also possible to print desired designs.

Furthermore, the "metal plate" as used in the present invention is not particularly limited and can be any metal plate, but generally, for example, it is an iron-based, aluminum-based, copper-based metal plate, etc. Of these, iron-based and aluminum-based metal plates are preferred.

The iron-based metal plate may be any metal plate whose composition mainly contains iron, and specifically,
Examples include cold-rolled steel sheets, galvanized steel sheets, zinc alloy-plated steel sheets, aluminum-plated steel sheets, copper-plated steel sheets, stainless steel sheets, phosphate-treated steel sheets, and aluminum-zinc alloy-plated steel sheets. Among them, galvanized steel sheets, zinc alloy-plated steel sheets, etc. Preferred are steel plates, aluminum plated lead steel plates, aluminum-zinc alloy plated steel plates, and stainless steel plates.

Further, as the aluminum-based metal plate, any metal plate may be used as long as the metal plate mainly contains aluminum metal in its composition, but generally, for example,
It is an aluminum plate described in pages 13 to 22 of "Aluminum Handbook (2nd edition)" published by the Light Metals Association of Japan on September 30, 1997, and specifically, pure aluminum, (At
Cu) system, (AI-Mn) system, (AI-8i) system, (A
I-Mg) system, (AI-Mg-5i) system and (A
There are I-Zn-Mg) type plates, among which pure aluminum type, (AI-Mn) type and (AI-Mg) type plates are preferable.

Although the thickness of the metal plate in the present invention is not particularly limited, it is generally, for example, 01 to 10 m/m, preferably 0.2 to 5 m/+++.

Next, the fluorine-containing resin film that will be the first layer and the metal plate that will be the substrate must be joined, and the joining methods include using an adhesive and heat-sealing.
A method of heat fusion welding is preferred.

Films can be bonded by heat fusion welding using conventional methods, but generally include a pretreatment process, a heating process, film lamination, a pressurization process, a reheating process, and a cooling process. It can be obtained by the following steps.

The above steps will be explained below.

(1) Pretreatment Step This step is a step that is carried out as necessary to coat the metal plate and the fluorine-containing resin film more strongly.

■ Pre-treatment process of metal plates The purpose of pre-treatment of metal plates is to remove oily substances that adhere to the surface.
Cleaning and removing foreign substances, oxide films, etc., exposing bare metal to the surface by polishing, etc., surface plating,
Apply surface treatment such as acid treatment, and if necessary,
Add roughness to the surface, etc.

31 Surface cleaning There are no particular limitations, and cleaning methods conventionally used for specific metals may be used. For example, as a degreasing method,
Degrease and clean using organic solvents, alkaline aqueous solutions, surfactants, etc.

b. Surface polishing The base metal can be exposed on the surface by polishing the surface, for example, by mechanical or chemical polishing.

C.Surface Treatment If necessary, chemical conversion treatments such as plating treatment, coating treatment for installing a metal oxide film layer, and antirust treatment can be performed on the surface covered with the film. For example, specific examples of chemical conversion treatments for iron-based metals include phosphate treatment with zinc phosphate, calcium phosphate, etc., and chromate treatment with reactive chromate, coating type chromate, and the like.

68 Surface Roughening The surface can be roughened by a surface roughening method using physical means such as brushing, sandblasting, shot blasting, etc., or by a surface roughening method using a chemical or electrochemical etching method or a combination thereof.

■ Film pre-treatment process Removing oily matter, foreign matter, etc. adhering to the film surface, applying an oxide film etc. by corona discharge treatment, straw material treatment, etc., and using various surface treatment agents. For example, treatments such as coating aminosilane, vinylsilane, mercaptosilane, etc. can be performed.

(2) Heating process This is a process in which the pretreated metal plate is heat-treated in the air or in an atmosphere substantially free of oxygen. In the present invention, the latter is particularly preferable in the case of iron-based materials, and is also necessary. In this step, the film is also heat-treated at the same time.

■Heating atmosphere The above-mentioned “substantially oxygen-free atmosphere” means:
There is no particular restriction as long as the atmosphere can heat the metal plates and films that have undergone the pretreatment process while substantially maintaining their surface conditions, but specifically, the atmosphere may have an oxygen content of 1% or less preferable. To create this heating atmosphere, it can be filled with an inert gas or heated in a vacuum state. Any type of inert gas may be used, but generally nitrogen gas, argon gas, neon gas, helium gas, etc. are preferred, with nitrogen gas and argon gas being preferred, and nitrogen gas being particularly preferred.

In addition, the vacuum state is 5 Torr or less, preferably I
Torr or less, more preferably 0.1 Torr or less.

■Heating temperature The optimum heating temperature is determined depending on the type of fluororesin film and metal plate to be coated, but in general, the softening point temperature (mp) of the fluororesin film
Above, preferably (mp +30) 'C or higher, more preferably (mp +50) 'C or higher, and lower than the thermal decomposition temperature. Specifically, in the case of a fluorine-containing resin film, tetrafluoroethylene・For perfluoroalkoxyethylene copolymers, generally 280 to 400°C
, in the ethylene-tetrafluoroethylene copolymer,
Generally 260-370°C, for ethylene-chlorotrifluoroethylene copolymer, generally 220-350°C.
°C, and 250 to 300 °C for polyvinylidene fluoride.

■ Heating time Heating time varies depending on the heating method and is not something that should be specified in particular.It must be the time required for at least the surface of the metal plate to reach the heating temperature, and may be adjusted as appropriate depending on the type and thickness of the metal plate. It is determined.

(3) Lamination process This process is a process of covering a heated metal plate with a fluorine-containing resin film by lamination and pressing.

■ Lamination atmosphere The lamination atmosphere is not particularly restricted, but in the case of iron-based materials, it must be an atmosphere that is substantially free of oxygen, at least until the film is laminated and placed on the heated metal plate. It is desirable that the atmosphere be similar to that of the previous step (2).

■ A film laminated and placed on a press-heated metal plate, for example,
This is a process of continuously pressing with a book roll or the like to strongly coat the material. Here, the roll in contact with the film is preferably a roll that does not stick to the film, such as a rubber roll or a metal roll, and the pressing force is 5 to 30 kg/cm.
, preferably 10-20 kg/Cm'.

(4) Reheating process This process is a reheating process that is performed as necessary to further strengthen the fusion force between the metal plate and the film of the film-coated metal plate obtained in the previous process.

(2) Heating Atmosphere The heating atmosphere is not particularly limited, and may be in the air, but is preferably an atmosphere similar to that in the previous step (2).

■ Heating temperature The optimum heating temperature is determined as appropriate depending on the type of fluororesin film and metal plate to be coated, but generally it is higher than the softening point temperature (mp) of the fluororesin film, preferably (mp +20) °C or higher, more preferably (mp +30) °C or higher and lower than the thermal decomposition temperature. Specifically, in the case of a fluororesin film, tetrafluoroethylene/perfluoroalkoxyethylene For copolymers, generally 280 to 400°C, for ethylene-tetrafluoroethylene copolymers, generally 260 to 360°C, and for ethylene-chlorotrifluoroethylene copolymers, generally 220 to 350°C. °C and 200 to 250 °C for polyvinylidene fluoride.

■ Heating time The heating time does not have to be specified in particular; it must be at least the time it takes for the metal plate to reach a predetermined temperature and for the welding force to be sufficiently developed. The time is determined, but is generally between 1 and 20 minutes.

(5) Cooling Step This step is a step of cooling the reheated film-coated metal plate to room temperature, and can be cooled, for example, with an air cooling fan, water, or the like.

The film-coated metal plate of the present invention obtained through the above steps exhibits strong adhesive strength between the metal plate and the fluorine-containing resin film, and has excellent durability.

As the printing layer, it is preferable to provide the printing layer described in Japanese Patent Application No. 1-73899 and Japanese Patent Application No. 1-139155. For example, the printed layer in Japanese Patent Application No. 1-73899 is a fluororesin layer heat-sealed to the metal surface, and the uppermost layer is made of a fluororesin composition with a thixotropic index (TI value) of 2 to 8. The printing layer is formed by printing using the ink of
As the printed layer of No. 73899, a preferred embodiment is a printed layer formed by heat-sealing a fluororesin film having a printed layer on a metal surface with the printed layer inside.

In order to impart a curved shape to the laminate of metal and fluorine-containing resin film obtained through the above steps, conventional steps such as cutting, bending, pressing,
etc. can be used.

Next, a method for providing a curved surface will be explained using an example of creating the shape shown in FIG. 3.

A schematic diagram of the process is shown in Figure 5. The first step is Figure-5-(
Cut into the specified shape as shown in b). In the second step, as shown in Figure 5-(b), a notch with an appropriately determined width and depth is made on the side that will undergo bending deformation. In the third step, the notched laminate thus obtained is bent and formed into a box shape as shown in Figure 5-(c). In the fourth step, as shown in Fig. 5-(d), bending is performed in small increments of one notch using a press brake, and the final curved surface is finished.

As described above, the curved panel of the present invention can be obtained by combining bending and notching.

In this figure, the rising depth a1 flange width b1 notch width C1 notch interval d1 notch depth e are not particularly limited and may be determined as necessary. In general, a is 3 to 100 mm, b is not particularly limited, and the notch depth C may be any value as long as no wrinkles or cracks occur during bending, but generally (a + b) - c. It is preferable to set it so that it satisfies the range of 1 to 15 mm. The notch width and the notch spacings d and e are also sufficient as long as there are no wrinkles or cracks in the rising portion, and are generally preferably 1 to 10 mm, although they are not limited. Also, when bending with a press brake, it is desirable to use a mold with (panel dimension C) - (plate thickness x 2).
Furthermore, it is preferable that the amount of bending be done for one notch period at a time.

The curved panel obtained by nature is not limited to the one shown in Figure 5. For example, if you change the lengths of A and B in Figure 5, you can obtain a part of a cone instead of a cylinder, and It is obvious that scales with two shapes joined together can be easily made, and can be made into various shapes.

The thus obtained laminate having the curved surface of the present invention has no welded parts, or even if there are welded parts, they can be extremely small, so there is no damage to the film, and there is no edge, so the desired design can be maintained in terms of appearance, and the original design can be maintained. The characteristics of the fluororesin film are exhibited and exhibits extremely excellent performance.

The present invention will be explained in more detail below with reference to Examples, but it goes without saying that the present invention is not limited only to the Examples.

Example 1 First, an aluminum plate of A 3004P-H34 (thickness 2 mm) specified in JISH4000 was used as an aluminum base material, and the surface of the aluminum plate was sandblasted (using reduced iron powder 80 mesh, pneumatic pressure 3 kg/ cm”) to roughen the Ra (center line average roughness) to 1.8 μm, and then electrolytically etched the surface with a Ra of 35 μm in a 4% sodium chloride aqueous solution at a current density of 3.3 A/drrf. Formed.

This aluminum plate was heated to a temperature of 350°C, and a 50 μm thick ethylenetetrafluoroethylene copolymer film (melt flow index 3) was formed on the rough surface.
0 mm" (7 seconds)) to obtain a fluororesin laminated aluminum plate having the same shape as shown in FIG.

The above heat fusion bonding is performed by pressing the heated metal plate and the above film together using a silicon roll with a diameter of 10c+y at a pressure of 15cm.
The conditions were kg/cm.

The resin-laminated aluminum plate formed as described above was used to produce a processed laminate as shown in FIG.

1st process, AS8300mm, C400, a20mm
, cut to size b15m+n.

In the second step, three notches were made for c, d, and e so that they were 3 mm and 10 mm.

3rd process, press brake as shown in Figure-5-(c)
The shape was bent.

4th step, using a press brake, the amount of deformation shown in Figure 1 is 6
This was done in mm increments and the result was as shown in Figure-5-(d).

Example 2 A similar panel was made by changing the resin film laminate of Example 1 to the following.

One side of a 40μ transparent film of tetrafluoroethylene/ethylene copolymer was surface-treated using a corona discharge device (manufactured by Kasuga Denki) at a discharge power of 120W/rd-min. Surface activated to a wettability index of 42 dyne, and printed with the ink listed below with an aperture of 2.
Printing was carried out on the transparent film made of ethylene-tetrafluoroethylene copolymer using a 70-mesh Tetron screen. This printed material was heat-dried for 10 minutes in a hot air circulation dryer at 120° C. to obtain a printed film in which a printed layer of 10μ thick consisting of a thin film of the ink was formed in close contact with the fluororesin layer.

On the other hand, one side of a 1100 series aluminum rolled plate shown in J I 5-H-4000 with a thickness of about 2.0 mm was coated with an average unevenness depth of 10 to 15 microns (surface roughness) of 1.0 mm. After sandblasting to a concavo-convex pitch of 10 to 20 microns, surfaces other than the above-mentioned one side are masked with vinyl chloride resin, and the above-mentioned sandblasted surface is electrolytically etched. This electrolytic etching treatment was carried out using a 13% NaC aqueous solution at a temperature of 40°C, an electrolytic density of 4 amperes/dtrr, and a current flow rate of 35 coulombs/cm''.

After washing and drying the etched surface, the aluminum plate was preheated to 310°C, the transparent film was placed on the etched surface, and the film was pressed with a pressure of 20 kg/cl' [12], followed by heat treatment at 315°C for 10 minutes. A fluororesin layer was formed on the aluminum plate, and the resin-coated metal plate of the present invention was obtained, in which the printed layer was laminated on the back side of the fluororesin layer.

(Production method of ink) A copolymer of tetrafluoroethylene, cyclohexyl vinyl ether, ethyl vinyl ether, and hydroxybutyl vinyl ether was obtained by a conventional method. In this copolymer, the molar ratio of each component is 50: 18: 22: 10 (according to the magnetic resonance method), and the intrinsic viscosity of the copolymer at 30°C in tetrahydrofuran is 0.4 d.
It was l/g. 100 g of this copolymer was dissolved in 80 g of carpitol acetate and 20 g of toluene, and 50 g of titanium oxide and 6 g of colloidal silica were added thereto and thoroughly mixed using a three-roll mill to obtain an ink composition. The viscosity of this composition was 270 ps, and the TI value was 5.

Example 3 The resin film laminate of Example 1 was changed to the one shown below.

The surface of an Al100P-HI3 (aluminum) plate specified in JIS A4000 with a thickness of 2 mm was sanded with a diameter of 50 m using sandpaper with a roughness of No. 80.
Using a milling machine to which a circular metal plate of m is fixed, the rotation speed of the milling machine is 1100 rpm and the scribing speed is 100 cm.
The marking process was performed under the condition of /min. The scribing depth of the obtained linear scribing pattern was 1 μm.

After degreasing the surface of the scribed aluminum plate with a 1% caustic soda aqueous solution, the same thickness as in Example 1 was obtained.
μ ethylene-tetrafluoroethylene copolymer resin film (
A resin laminated metal was obtained by heat-sealing at a volumetric flow rate of about 20 mm (7 seconds).

The conditions for the heat fusion are as follows: The aluminum plate and the film, which have been preheated to 360°C, are pressed at a pressure of 100kg using a silicone roll with a diameter of 10cm, and then post-treated at 340°C for 10 minutes. This is what we do.

The performance of the panels obtained in the above examples was evaluated. The results are shown in Table-1.

Table 1 (Evaluation method) 1. Both surfaces of the film laminate with weather resistance were evaluated according to JISA 1415.
Using WS type Sunshine Carbon (manufactured by Suga Test Instruments) shown in 1977, an accelerated exposure test was conducted for 5 (100 hours), and its appearance was compared with the preserved test piece. It was marked as ○, and cases where there was a change were marked as ×.

2. Corrosion Resistance A CAST test specified in JIS H-8681 was conducted on both surfaces of the obtained film laminate. Evaluation was performed using visual rating numbers.

3. Stain resistance After the film-laminated metal plate obtained was left outdoors for 6 months, both surfaces were wiped with a cloth. Those that were completely wiped off were marked as ○.

4. Design Those in which the printed design and scratched pattern were clearly visible were rated as ○.

As can be seen from Table 1 above, although the curved resin laminate according to the present invention does not have welded parts, only a very small amount is required, so there is no damage to the film due to welding, and the characteristics of the fluororesin film are fully exhibited and the appearance is also improved. Because the end of the metal cut is not visible, it is beautiful and reduces the hassle of repairs. It turns out to be very good.

[Brief explanation of drawings]

FIGS. 1 and 2 are examples of shapes to be implemented in the present invention. FIG. 3 shows a process diagram of a conventional method for producing an article having the shape shown in the figure. FIG. 4 is a schematic diagram of the cut surface at a in FIG. 3 (E). 1. Fluororesin film 2, metal plate 3, welded metal. This is an illustration and creation process diagram, where ASBSC: curved surface panel dimensions, a: upright depth, b: flange width, C: notch width, d: notch interval, e: notch depth. Patent applicant: Nippon Carbide Industries Co., Ltd. Figure-2 (A) Figure-3 c) (C) Figure-4 (C) Figure-5 (B) (D)

Claims (1)

[Scope of Claims] 1. A resin laminate, characterized in that a metal plate whose at least one side is coated mainly with a fluorine-containing resin film has a curved surface. 2. The resin laminate according to claim 1, wherein the fluorine-containing resin film and the metal plate are laminated by a heat fusion method. 3. The novel resin laminate according to claim 1, wherein the fluororesin film has a printed layer. 4. The novel resin laminate according to claim 1, wherein the fluororesin is a tetrafluoride resin. 5. The novel resin laminate according to claim 4, wherein the tetrafluorinated resin is a tetrafluoroethylene/barfluoroalkoxyethylene copolymer (PFA). 6. The novel resin laminate according to claim 4, wherein the tetrafluoride resin is a tetrafluoroethylene/ethylene copolymer (ETFE). 7. The novel resin laminate according to claim 1, wherein the film has a thickness of 5 to 200 μm. 8. The novel resin laminate according to claim 1, wherein the metal of the metal plate is an aluminum metal plate. 9. The novel resin laminate according to claim 1, wherein the metal of the metal plate is an iron-based metal plate. 10. A novel resin laminate according to any one of claims 1, 8 and 9, wherein the metal plate has a thickness of 0.1 to 10 m/m.