JPH0834091A - Production of metal/resin laminated sheet - Google Patents

Abstract

PURPOSE:To produce a laminated sheet enhanced in the bonding strength of a metal sheet and a polyolefinic resin sheet without using an adhesive resin used heretofore at the time of the bonding of both sheets. CONSTITUTION:In producing a metal/resin laminated sheet by bonding a polyolefinic resin sheet to a metal sheet, at first, the surface of the polyolefinic resin sheet is exposed to gas containing fluorine of which the partial pressure is 0.1-26% when the total pressure of gas is set to 100% to be modified and, subsequently, the metal sheet is bonded to the modified surface of the resin sheet under heating.

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 metal resin laminate, and more particularly to a method for producing a metal resin laminate in which a metal sheet is laminated on both sides or one side of a polyolefin resin sheet. Is.

[0002]

2. Description of the Related Art Conventionally, a laminated plate in which a metal sheet is laminated on both sides or one side of a polyolefin resin sheet is characterized by light weight, high strength, and easy workability. It is used as a material for interior materials, signboards, and furniture such as cabinets and boxes. However, the polyolefin-based resin, which is one of the materials for the laminated plate, does not have a polar group in its molecular structure, and therefore has a drawback that the adhesive force is weak when it is bonded to a metal sheet.

In order to improve this poor adhesion, (1)
A method of forming a multi-layered sheet of adhesive resin on the surface of a polyolefin resin sheet using a method such as coextrusion method, and then heating and adhering a metal coated with a primer, (2) Adhesion of a polyolefin resin sheet and a metal sheet In order to improve the properties, a method of using an adhesive resin grafted with an adhesive functional group such as an acid anhydride has been proposed. However, the method of (1) above requires a large amount of energy, not only has poor productivity, but also integrally molds other types of resins with different heat resistance and moldability, so when molding a resin with low heat resistance There was a problem that it was decomposed by the heat of, causing deterioration of physical properties. The method (2) has a problem that a trace amount of the adhesive functional group remains in the adhesive resin, and the residue has a bad influence on the adhesion durability between the resin and the metal, particularly the water resistance.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to use a polyolefin-based resin sheet and a metal sheet without using a substance which adversely affects the adhesion durability, which has been used in the past. It is an object of the present invention to provide a method for producing a laminate having improved adhesiveness.

[0005]

In order to solve the above-mentioned problems, in the invention described in claim 1 of the present invention, in producing a metal-resin laminated plate in which a polyolefin-based resin sheet is laminated on a metal sheet, first, The surface of the polyolefin resin sheet is exposed by exposing it to a gas containing fluorine having a partial pressure of 0.1 to 26% when the total gas pressure is 100% with the surface of the polyolefin resin sheet as a gas. The means for heating and adhering the sheet is taken.

The present invention will be described in detail below. In the present invention, the polyolefin resin refers to a polymer containing olefin, and includes homopolymers and copolymers.
Specifically, ethylene, propylene, butene-1,3-
Homopolymers of α-olefins represented by methylpentene-1, 4-methylpentene-1 and the like, or these α
-Copolymers of olefins, copolymers of α-olefins and monomers copolymerizable therewith, homopolymers of olefins other than α-olefins, or copolymers of these olefins , Copolymers of olefins and monomers copolymerizable therewith, and the like. These polyolefin resins may be used alone or as a mixture of two or more kinds of polymers.

As the ethylene-based polymer, a low-density homopolymer having a large number of long-chain branches produced by a high-pressure method, copolymers of ethylene and vinyl acetate, acrylic acid, methacrylic acid, acrylate, methacrylate and the like; High-density polyethylene produced by the low-pressure method, copolymers of ethylene and other olefinic monomers; and high-density polyethylene produced by the medium-pressure method, copolymers of ethylene and other olefinic monomers, And so on.

The propylene-based polymer includes polypropylenes having stereoregularity such as isotactic polypropylene and syndiotactic polypropylene, and non-crystalline polymers such as atactic polypropylene. Examples of olefin polymers higher than propylene include butene-1 polymers, which also include crystalline polymers with high stereoregularity to amorphous polymers. As a higher olefin polymer, poly 3-
Methylbutene-1, poly 4-methylpentene-1, etc. are mentioned.

Specific examples of the copolymers include copolymers of ethylene and propylene, copolymers of ethylene and butene-1, copolymers of ethylene and n-hexene-1, and propylene and butene. 1 and a copolymer of propylene and xene-1. The copolymers are
Either a random copolymer or a block copolymer may be used,
It may be a terpolymer. Further, the content of the copolymer in the range not significantly impairing the effect of the present invention, for example, 30% by weight
Below, preferably 15% by weight or less, unsaturated carboxylic acid, divinylbenzene, vinylsilane and the like may be contained.

The above-mentioned polyolefin resin may contain the following additional components as long as the effects of the present invention are not significantly impaired. As an additional ingredient,
Examples include elastomers, inorganic fillers, and other additives. Specific examples of the elastomers include olefin-based, styrene-based, and acrylic-based elastomers. Specific examples of the inorganic filler include natural silica such as quartz; synthetic silica produced by a wet method or a dry method; natural silicates such as kaolin, mica, talc, and asbestos; synthetic silicates such as calcium silicate and aluminum silicate; montmorillonite. Layered clay minerals such as; Metal hydroxides such as magnesium hydroxide and aluminum hydroxide; Metal oxides such as alumina and titania; Metal powders such as aluminum and bronze; Fibers such as glass fiber and carbon fiber; Carbon black and titanium Potassium acid, calcium sulfate,
Calcium carbonate, zinc oxide, silicon nitride, sapphire,
Examples include whiskers such as beryllia, boron carbide, and silicon carbide. Specific examples of other additives include a foaming agent, a colorant, a stabilizer, a dispersion aid, a molecular weight modifier, a cross-linking agent, a cross-linking aid, and a crystal nucleating agent.

In the method of the present invention, the above polyolefin resin must be formed into a sheet. The thickness of the sheet can be selected in the range of 0.05 to 6 mm, and the production method is not limited, and the T-die method,
It can be produced by an inflation method, a calendar method, or the like. The sheet may be stretched or unstretched. When the method of the present invention is used, the polyolefin resin sheet is adhered to a metal sheet. The type of metal of the metal sheet is not particularly limited, but when the finally obtained laminate is used for building materials, various plated steel sheets,
Aluminum, titanium, stainless steel (SU
S), copper and the like are preferable. The thickness of the metal sheet is 0.0
It can be selected in the range of 5 to 2 mm, and the production method can be based on a conventional method.

When manufacturing a laminated sheet by the method of the present invention, first, the above-mentioned polyolefin resin sheet is exposed to a gas containing fluorine for surface modification. By the surface modification by exposing to the gas, the adhesiveness between the polyolefin resin sheet and the metal sheet can be improved. The gas containing fluorine may be a mixed gas of fluorine and an inert gas. Examples of the inert gas that can be used by mixing with fluorine include gases of Group 8 elements of the Periodic Table of Elements such as helium, neon, and argon, and nitrogen. Oxygen can further coexist in the mixed gas of fluorine and an inert gas. The partial pressure of oxygen in this case is 100% of the total gas pressure.
In that case, the range can be selected up to 80%. The mixed gas of fluorine and the inert gas may be a mixed gas in which other gas including dry air is mixed as long as the effect of the present invention is not impaired.

According to the experiments conducted by the present inventors, the gas containing fluorine is a gas containing fluorine having a partial pressure of 0.1 to 26% when the total gas pressure of the gas containing fluorine is 100%. It was found that the object of the present invention was effectively achieved.
If the partial pressure of fluorine in the gas containing fluorine is less than 0.1%, it takes a long time to obtain the required adhesiveness improving effect, although it depends on the temperature condition of the modification treatment. If the partial pressure of fluorine exceeds 26%, the treated surface becomes water repellent and the adhesiveness deteriorates, either of which is not preferable. In the above range, the fluorine partial pressure is preferably 0.1 to 10%, more preferably 0.1 to 8%.

The time for exposing the polyolefin resin sheet to a gas containing fluorine depends on the partial pressure of fluorine contained in the gas, the temperature condition of the reforming treatment, etc., but is 0.01 to 6
You can choose in the range of 0 minutes. In less than 0.01 minutes,
It is difficult to achieve the desired effect of improving the adhesiveness in a stable manner, and if it exceeds 60 minutes, the treated surface becomes water repellent and the adhesiveness deteriorates. The preferable exposure time in the above range is 0.1 to 30 minutes, and more preferable is 0.
It is in the range of 5 to 20 minutes. The surface modification of the polyolefin resin sheet with a gas containing fluorine can be added to the sheet manufacturing step, but the step of performing only the surface modification without adding to the sheet manufacturing step may be independent.

When a laminate is produced by the method of the present invention, the surface of the polyolefin resin sheet is modified as described above, and then the polyolefin resin sheet surface and the metal sheet are heat-bonded. The adhesion of the metal sheet may be performed on only one side or both sides of the polyolefin resin sheet depending on the use of the final product. The heating temperature at this time is usually J for polyolefin resins.
It can be selected within a range in which the lower limit is the embrittlement temperature measured according to IS K7216 and the upper limit is the melting temperature of the resin. The upper limit is more preferably the softening point measured according to JIS K7206.

As a method for heat-bonding the surface of the polyolefin resin sheet and the metal sheet, a conventionally known method can be adopted without restriction. Specific examples of the heat-bonding method include a batch-type heat-bonding method using a heat press; a partial heat-bonding method such as a heat sealer and spot welding; a continuous heat-bonding method using a heating / pressurizing roll. . Before heat-bonding the surface of the polyolefin resin sheet and the metal sheet, (1) auxiliary surface treatment, and (2) modification treatment of the metal sheet surface for the purpose of improving the adhesiveness. It is preferable to carry out. The auxiliary surface treatment of (1) includes degreasing and cleaning treatment of the metal sheet surface, and the modification treatment of the metal sheet surface of (2) includes chromate surface treatment, primer coating treatment, plasma treatment, Examples include corona treatment and electrolytic treatment. These surface treatments can also be performed by combining a plurality of treatments.

According to the method of the present invention, a metal-resin laminated plate having a metal sheet laminated on one or both sides of a polyolefin resin sheet can be obtained. This metal-resin laminate is lightweight, yet exhibits excellent strength and excellent workability, so it can be used as a building exterior material, interior material, signboard material, cabinet, box furniture, etc. Can be used.

[0018]

Industrial Applicability The method of the present invention has the following excellent advantages, and its industrial utility value is extremely large. (1) In the method of the present invention, since other types of resins having different heat resistance and moldability are not used, the resin having low heat resistance is not decomposed by heat during molding, and the physical properties are not deteriorated. (2) In the method of the present invention, since there is no substance that adversely affects the adhesion durability, a product having excellent adhesion durability at the adhesive interface between the resin sheet surface and the metal sheet surface, and particularly excellent water resistance can be obtained.

Next, the present invention will be described in more detail based on examples, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded. In the following examples,% means% by weight. [Examples 1 to 5, Comparative Examples 1 to 5] (Production of Resin Sheet) The resin sheets used in Examples 1 to 5 and Comparative Examples 1 to 5 were produced by the following procedure. Pelletized polyethylene (F100, MFR = 0.4, manufactured by Mitsubishi Kasei Co., Ltd.) is supplied to an extruder (SX125, L / D = 32) manufactured by Ikegai, which is equipped with a 1850 mm wide T-die manufactured by Ikegai. Then, the mixture was kneaded at a cylinder temperature of 230 ° C. and continuously extruded into a sheet under the temperature condition of a T-die temperature of 230 ° C. The sheet extruded from the T-die was cooled by adjusting the thickness with a molding roll and further cooled to a softening point or lower with a cooling roll, and a sheet having a thickness of 4 mm was wound into a roll shape. The obtained sheet was cut into a size of 150 mm × 150 mm and used for a heat adhesion test.

(Treatment of Resin Sheet Surface with Gas) In Examples 1 to 5, the resin sheet surface was treated with gas by the following procedure. The above-mentioned heat-adhesion test sheet was placed in a container having a capacity of 2.5 liters, which was resistant to fluorine, and after being evacuated, fluorine (F ₂ ) and oxygen (O _2
2 ) and nitrogen (N ₂ ) were introduced into the mixed gas having the partial pressures shown in Table 1 to adjust the internal pressure to 760 torr. After allowing the temperature inside the container to stand at 23 ° C. for 5 minutes, the mixed gas was evacuated, nitrogen was introduced to adjust the internal pressure to 760 torr, and the resin sheet which had been surface-treated with gas was taken out. In Comparative Examples 1 to 5, the surface of the resin sheet was not treated with gas.

(Preparation of Metal Sheet) The metal sheets used in Examples 1 to 5 and Comparative Examples 1 to 5 were commonly applied to the following (1) to (3), but (4) was carried out. Example 5 and Comparative Example 5
Only applied to. (1) Preparation of metal sheet First, an aluminum sheet (Al 1
100 H18), copper plate (Cu), hot dip galvanized steel plate (Fe) and stainless steel sheet (SUS30)
3) was prepared. (2) Degreasing and washing with water Prepare an aqueous solution (room temperature) of 2% surfactant, 0.1% hydrofluoric acid and 0.6% sulfuric acid, immerse the above metal sheet in this aqueous solution for 1 minute, and degrease the surface of the metal sheet. After the treatment, the metal sheet was washed with tap water. (3) Chromate surface treatment The metal sheet which had been subjected to the above treatment was immersed in a 5% chromium chromate solution and pulled up, kept vertically in the air, and naturally dried. (4) Primer application Epoxy primer is applied to a metal sheet as a liquid film with a thickness of about 10 μm using a bar coater, and is applied in an oven for 2 minutes.
It was baked and dried at a temperature of 20 ° C. for 1 minute.

(Heat Adhesion) As a combination shown in Table 1, a metal sheet was overlaid on one side of a polyolefin resin sheet (in Example 5 and Comparative Example 5, the primer coated surface was brought into contact with the resin sheet). , The protective polytetrafluoroethylene sheet and the iron plate are placed on the top and bottom, and using a hot press, the heating surface temperature is 160 ° C., the press pressure is 100 k
The product was held at gf / cm ² (gauge pressure) and a clearance of 4 mm for 3 minutes, and then cooled to room temperature using a cooling press to obtain a product metal resin laminate.

(Evaluation of Adhesiveness) With respect to the obtained product, the peel strength at the adhesive interface between the resin sheet and the metal sheet was measured by JI.
It was measured according to SK6854. Tensilon (manufactured by Toyo Seiki Co., Ltd.) was used as the tester, the test piece was for 180 degree peeling, the width of the test piece was 25 mm, and the peeling speed was 100 mm / min. The measurement results are shown in Table 1 as a unit of kgf / 25 mm.

[0024]

[Table 1]

From Table 1, it can be seen that the metal resin laminate obtained by the method of the present invention is excellent in peel strength at the adhesive interface between the resin sheet and the metal sheet, while that of the laminate of Comparative Example is significantly large. Is clearly inferior to.

Claims (4)

[Claims] 1. When manufacturing a metal-resin laminated plate in which a polyolefin-based resin sheet is laminated on a metal sheet, first, 0.1-26% of the total amount of gas is 100% when the surface of the polyolefin-based resin sheet is used as a gas. A method for producing a metal-resin laminate, which comprises exposing to a gas containing fluorine at a high pressure for modification, and then heat-bonding the surface-modified resin sheet surface and a metal sheet. 2. The method for producing a metal-resin laminated plate according to claim 1, wherein the gas containing fluorine is a mixed gas of fluorine and an inert gas. 3. The gas containing fluorine is a mixed gas of fluorine, oxygen and an inert gas.
A method for producing the metal-resin laminated plate described. 4. The method for producing a metal-resin laminate according to claim 1, wherein the gas containing fluorine is a mixed gas of fluorine, oxygen, an inert gas and dry air.