JPH04229246A - Fresh fluorine containing resin film laminated metallic sheet - Google Patents

Abstract

PURPOSE:To obtain a fluorine resin film laminated metallic sheet which is rich in corrosion resistance and weather resistance, by laminating fluorine containing resin films on at least both sides of the metallic sheet. CONSTITUTION:Tetrafluoroethylene resin is preferable as fluorine resin. A film thickness of that layer is preferably 10-200mum, further preferably 20-100mum. As for a manufacture of the film, film making can be performed appropriately by, for example, a heat fusion extrusion method and casting method and a pigment or dye or glass powder can be compounded with the resin at need. Then a desired pattern can be printed also on the surface. Although whichever metallic sheets can be used as a metallic sheet, an iron or aluminum sheet is preferable. A sheet thickness of the metallic sheet is preferably 0.2-5m/m. Preferable forming method of a fluorine resin layer is a heat fusing laminating method.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a novel fluororesin-based film laminated metal plate, and more specifically, at least both sides thereof are laminated and coated with fluororesin-based films. This relates to a metal plate that has extremely excellent properties such as corrosion resistance.

[Conventional technology] Traditionally, walls of tunnels, underground passages, sewage, water, gas, and water pipes and other common ditches, underwater and offshore structures such as drilling facilities for underwater oil fields, quay walls of ports, pools, and water tanks , chemical containers, tanks Metal plates used for chemical factory building walls, wall replacement machines, expressway side walls, shutters, ducts, hoods, traffic signs, information boards, etc. Only one side of the plate has a function. Rather, both sides need to have various functions. For example, tunnels, underwater and offshore structures, and side walls of public ditches require extremely high corrosion resistance on both the inside and outside surfaces, while water tanks, swimming pools, underground passages, and highway side walls require corrosion resistance on one side.
Other surfaces are required to have good design and weather resistance; ducts, hoods, etc. are required to be stain resistant and corrosion resistant, and signs, etc., with letters, pictures, etc., are required to be weather resistant on both sides.

For this purpose, both sides of the plate are required to have functions according to their respective purposes, but until now there has been no metal plate that can meet these various and sophisticated requirements.

[Problems to be solved by the invention] The purpose of the present invention is to solve the above-mentioned problems of the prior art, and to provide novel corrosion resistance and weather resistance that were completely unknown in the past. The present invention provides a fluororesin film laminated metal plate with excellent stain resistance and design.

[Means for Solving the Problems] The present invention has been made to solve the above-mentioned problems, and provides a novel metal plate characterized in that a fluorine-containing resin film is laminated on at least both sides of the metal plate. This is what we provide.

The configuration of the present invention will be explained in more detail below.

The "fluorine-containing resin" as used in the present invention is not particularly regulated as long as it contains a fluorine atom in the molecular structure of the resin. Tetrafluoroethylene resins having four fluorine atoms, trifluoroethylene resins, difluoroethylene resins, monofluoroethylene resins, copolymers containing these resins as constituent units, and mixtures. Among them, tetrafluoroethylene resin and difluoroethylene resin are preferred, and tetrafluoroethylene resin is more preferred. Here, the tetrafluoroethylene resin specifically refers to, for example, tetrafluoroethylene resin (PTFE), tetrafluoroethylene/perfluoroalkoxyethylene copolymer (PFA), etc.
, tetrafluoroethylene/hexafluoropropylene/perfluoroalkoxyethylene copolymer (EPE), tetrafluoroethylene/ethylene copolymer (ETFE), tetrafluoroethylene/cyclohexyl vinyl ether/hydroxy vinyl ether copolymer etc., especially ETFE, PFA
is preferred. In addition, the above-mentioned trifluoroethylene resin specifically refers to, for example, trifluorochloride ethylene resin (PCT
FE) and trifluorochloroethylene/ethylene copolymer (
ECTFE), among which PCTFE is preferred. Specifically, the difluoroethylene-based and monofluoroethylene-based resins include, for example, vinylidene fluoride resin (P
VDF) and vinyl fluoride resin (PVC).

It goes without saying that the fluorine-containing resin film layers used on both sides of the present invention should be free from damage such as pinholes, but a desired printed layer can also be provided.

The thickness of the layer may be any thickness, but generally it is 5 to 5.
00μ, preferably 10 to 200μ, more preferably 2
It is 0 to 100μ.

These fluororesin films can be produced by conventional methods, such as hot melt extrusion, casting, etc., and if necessary, pigments, Dyes, glass powder, glass beads, inorganic fillers such as glass fibers, aluminum oxide, talc, mica, silica, etc. can be blended, and desired designs can also be printed on the surface.

Furthermore, the "metal plate" used in the present invention is not particularly limited, and any metal plate can be used, but generally, for example, iron-based, aluminum-based, copper-based, titanium-based, and nickel-based metal plates are used. Among these metal plates, iron-based and aluminum-based metal plates are preferable.

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. Steel plates, aluminum-plated lead steel plates, aluminum-zinc alloy plated steel plates and stainless steel plates are preferred.

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, 2015, and specifically, pure aluminum, (Al-
Cu) system, (Al-Mn) system, (Al-Si) system, (A
l-Mg) system, (Al-Mg-Si) system and (Al-Z
n-Mg) type plate.

Although the thickness of the metal plate in the present invention is not particularly limited, it is generally, for example, 0.1 to 10 m/m, preferably 0.2 to 5 m/m.

Next, a thermal fusion lamination method, which is a preferred method for forming the fluororesin layer, will be explained.

Films can be laminated by conventional methods to heat and fuse them, but generally include a pretreatment process, a heating process, film lamination, a pressure process, a reheating process, a cooling process, etc. It can be obtained by the process of 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 for metal plates The purpose of pre-treatment for 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.

a. Surface cleaning is not particularly limited, and conventional cleaning methods 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 bare metal can be exposed on the surface by surface polishing, such as mechanical and chemical polishing.

c. Surface Treatment If necessary, the surface covered with the film may be subjected to chemical conversion treatments such as plating treatment, coating treatment for installing a metal oxide film layer, and antirust treatment. 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.

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

■Film pre-treatment process: Removal of oily matter, foreign matter, etc. adhering to the film surface, addition of an oxide film, etc. through corona discharge treatment, chemical treatment, etc., and 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, and if necessary, the film is also heat treated at the same time.

■Heating atmosphere The “substantially oxygen-free atmosphere” mentioned above means:
There are no particular restrictions on the atmosphere as long as it can be heated while substantially maintaining the surface condition of the metal plates and films that have undergone the pretreatment process, but specifically, the atmosphere is such that the oxygen content is 1% or less. It has a certain atmosphere. 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 in general, nitrogen gas, argon gas, neon gas, helium gas, etc. are used, among which nitrogen gas,
Argon gas is preferred.

Also, a vacuum state is 5 Torr or less, preferably 1 Torr or less.
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
As mentioned above, it is desirable that the temperature is 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 fluororesin film, the temperature is For ethylene copolymers, generally 280-400℃, ethylene-
In tetrafluoroethylene copolymers, generally 26
0 to 370°C, generally 220 to 350°C for ethylene-chlorotrifluoroethylene copolymers, and 250 to 300°C for polyvinylidene fluoride.

■Heating time Heating time is not something that should be specified in particular; it needs to be the time required for at least the surface of the metal plate to reach the heating temperature, and may be determined as appropriate depending on the type and thickness of the metal plate. , generally 1 to 20 minutes, preferably 3 to 15 minutes
minutes, more preferably about 5 to 10 minutes.

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

(2) Lamination atmosphere The lamination atmosphere is preferably similar to the previous step (2).

■For example, two films are laminated and placed on a press-heated metal plate.
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 rubber roll or a metal roll that does not adhere to the film, and the pressing force is 5 to 30 kg/cm2, preferably 10 to 20 kg/cm2.

(4) Reheating process This step is a reheating step 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 step.

(2) Heating Atmosphere The heating atmosphere is not particularly limited, and may be in the atmosphere, 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 preferably at least the softening point temperature (mp) of the fluororesin film. (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 copolymer Generally, the temperature is 280 to 400°C, and for ethylene-tetrafluoroethylene copolymer, it is generally 260°C.
-360°C, generally 220-350°C for ethylene-chlorotrifluoroethylene copolymers, and 200-250°C for polyvinylidene fluoride.

■Heating time Heating time is not something that should be specified in particular; it must be at least enough time for the film to fully adhere to the metal plate, and is determined as appropriate depending on the type and thickness of the metal plate, but generally speaking It takes 1 to 20 minutes.

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

If non-uniform cooling is performed here, deformation will occur in the plate, so uniform cooling is desirable.

The film-laminated metal plate of the present invention obtained through the above process heats the metal plate and the fluorine-containing resin film to fuse and join them, so the metal plate and the fluorine-containing resin film have a strong fusion force. It is expected that the product will be able to be used for a long period of time.

The fluororesin-containing film-laminated metal plate obtained by the method described above has excellent corrosion resistance, chemical resistance, weather resistance, stain resistance, and wash resistance, and it also has excellent design properties because it can be colored and even have a printed layer. However, it is an excellent product and can be used for various purposes as mentioned above.

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 printing 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
A preferred embodiment of the printed layer in No. 73899 is a printed layer in which a fluororesin film having a printed layer is heat-sealed to a metal surface with the printed layer inside.

Hereinafter, the present invention will be explained in more detail with reference to examples, but it goes without saying that the present invention should not be limited only to the examples.

Example 1 First, an aluminum plate of A3004P-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) to reduce the average unevenness depth. After roughening to a pitch of 10 to 15 μm and a pitch of 10 to 20 μm, the current density was 3.3 A in a 3% sodium chloride aqueous solution.
After performing electrolytic etching under the condition of /dm2, the etched surface was washed with water and dried.

This aluminum plate was heated to a temperature of 350°C, and an ethylenetetrafluoroethylene copolymer film (Metroflow Index 3) with a thickness of 50 μm was formed on the rough surface.
0 mm3/sec) was heat-sealed to both sides to obtain a fluororesin laminated aluminum plate.

The above-mentioned heat fusion bonding was carried out by using a silicon roll with a diameter of 10 cm to bond the heated metal plate and the above-mentioned film together at a pressure of 20 k.
After pressure bonding under the condition of g/cm, it was further heated at 320° C. for 10 minutes.

Example 2 Instead of the film in Example 1, a white ethylenetetrafluoroethylene copolymer film (50μ) containing 8 parts by weight of titanium oxide on one side and a black film containing 2 parts by weight of carbon black on the other side was used. A double-sided film laminated metal plate was obtained in place of the ethylenetetrafluoroethylene copolymer film (50μ).

Example 3 The film on one side in Example 1 was replaced with the printed film shown below, and an example having a printed layer was thermally adhered to the treated aluminum surface to obtain a double-sided film laminated metal plate.

(Production method of printed film) One side of the transparent film used in Example 1 was treated with a discharge power of 120 W/m2 using a corona discharge device (manufactured by Kasuga Denki).
min. The surface of the film was surface-activated to a wetting index of 42 dyne, and the ethylene-tetrafluoroethylene copolymer was treated using the following ink and a Tetron screen with an opening of 270 mesh. Printing was performed on the above transparent film consisting of: 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 10 μm thick printed layer made of a thin film of the ink was formed in close contact with the fluororesin layer.

As the printing ink, a copolymer of tetrafluoroethylene, cyclohexyl vinyl ether, ethyl vinyl ether, and hydroxybutyl vinyl ether was obtained by a conventional method as described below. This copolymer has a molar ratio of each component of 50:22:10 (based on nuclear magnetic resonance method), and an intrinsic viscosity of the copolymer at 30°C in tetrahydrofuran of 0.4 dl/g. Met. 100 g of this copolymer, 80 g of carbitol acetate,
It was dissolved in 20 g of toluene, 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 is 270 ps. , the TI value was 5.

Example 4 S with thickness 0.8m/m specified in JIS G4304
One side of the US304 (stainless alloy) plate has a roughness of 200
Using a milling machine to which a circular metal plate with a diameter of 50 mm to which No. 1 sandpaper was attached was fixed, scribing was performed under conditions of a rotation speed of the milling machine of 100 rpm and a scribing speed of 10 cm/min. The scribing depth of the obtained linear scribing pattern was 1 μ.

Furthermore, a similar scribing pattern was made on the other side.

1% on both back sides of the SUA304 board that has been scribed above.
After degreasing with aqueous caustic soda solution, the same thickness as in Example 1 was obtained.
A film-laminated metal plate was obtained by heat-sealing a 0μ ethylene-tetrafluoroethylene copolymer resin film.

Example 5 Commercially available phosphate-treated electrical galvanized steel sheet (Nippon Steel:
Bonded steel plate EGC, thickness 0.6m/m) with an alkaline degreaser (Nippon Parkerizing Co., Ltd., Fine Cleaner 3)
Both surfaces were washed with water and dried at 60° C. for 3 minutes.

This steel plate was placed in a nitrogen-substituted heating furnace with an oxygen concentration of 0.1% and heat-treated at 350°C for 6 minutes. A 50 μm ethylenetetrafluoroethylene resin film was heat-sealed to both sides of the steel plate at a pressure of 7 kg/cm 2 . Further, this heat-sealed steel plate was reheated at 325° C. for 7 minutes in an oxygen atmosphere, and cooled by being left indoors to obtain an ethylenetetrafluoroethylene resin film laminated steel plate.

The performance of Examples 1 to 5 was evaluated and shown in Table 1 below.

(Evaluation method) 1. Both surfaces of the film laminate that has achieved weather resistance are tested according to JISA1415.
A 5000 hour accelerated exposure test was conducted using WS type Sunshine Carbon (manufactured by Suga Test Instruments) shown in No. 1977, and its appearance was compared with a preserved test piece. A case where the appearance was almost the same as that of the preserved test piece was marked as ○, and a case where there was a change was marked as ×.

2. Corrosion resistance The obtained film laminate was subjected to the CAST test specified in JIS H-8681 on both surfaces thereof. Evaluation was performed using visual rating numbers.

3. Chemical resistance Using the film laminates obtained in each example, a diameter of 5 cm and a depth of 2 cm
Prepare a container with a cylindrical diameter of m and put 3 cc of aqua regia inside.
The samples were left at ℃ and changes were observed with the naked eye. If there was no abnormality for 3 days, it was marked as ○.

Note that one container was made with both sides facing inwards.

5. Cut 100 squares on the workability test piece using the cross-cut method with a width of 1 mm, and draw it to 7 mm using a steel ball with a diameter of 20 mm using an Erichsen testing machine (ESM No. 1 manufactured by Tokyo Shikenki Seisakusho). . The test piece after drawing was subjected to a cellophane tape peeling test to determine the number of peeled pieces, and those with no peeling were rated as 0.

6. Design Items with clearly visible printed designs and markings were rated as 0.

As can be seen from Table 1 above, the double-sided fluorine-containing resin film laminated metal plate of the present invention not only has extremely excellent properties, but also can be designed to suit various uses. It is clear that it is incurable, applicable, and will contribute to a wide range of industries.

Claims (9)

[Claims] 1. A novel metal plate characterized in that a fluororesin film is laminated on at least both sides of the metal plate by a heat fusion method. 2. The novel metal plate according to claim 1, wherein the fluororesin is a tetrafluoride resin. 3. The novel metal plate according to claim 2, wherein the tetrafluorocarbon resin is an ethylene/tetrafluoroethylene copolymer. 4. The novel metal plate according to claim 1, wherein the fluororesin is a difluoride resin. 5. The novel metal plate according to claim 1, wherein the fluororesin film has a printed layer. Claim 6: The thickness of the fluororesin film is 5 to 500.
The novel metal plate according to claim 1, which is μ. 7. The novel metal plate according to claim 1, wherein the metal is an aluminum-based metal. 8. The novel decorative metal product according to claim 1, wherein the iron-based metal is an iron-based metal. 9. The novel metal plate according to claim 1, 6, or 7, wherein the metal is a plate having a thickness of 0.1 to 10 mm/mm. genus products.