JPH0263735A - Preparation of composite panel - Google Patents

Abstract

PURPOSE:To obtain a composite panel excellent in adhesiveness by applying a polyolefin layer modified with unsaturated carboxylic acid or a derivative thereof to the surface of a metal sheet as an adhesive layer and further applying the resin layer of the same kind as a thermoplastic resin sheet becoming a core material to said layer. CONSTITUTION:The low density polyethylene continuously extruded from an extruder 1 is passed through three rolls to form a polyethylene sheet which is, in turn, supplied to heating press-bonding rollers 2, 2'. An adhesive layer 9(a) composed of low density polyethylene modified, for example, through the grafting of 500ppm of maleic anhydride is applied to an aluminum sheet 10 and the low density polyethylene 9(b) of the same kind as the sheet 6 of a core material is used. The aluminum sheets 7, 7' to which the adhesive layers are applied are heated by preheaters 5, 5' and supplied to the heating press- bonding rollers to obtain a composite panel.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for manufacturing a composite plate consisting of a thermoplastic resin sheet and a metal sheet, and more specifically, to a method for bonding a thermoplastic resin sheet and a metal sheet. It concerns an improvement in the method.

[Conventional technology]

Composite boards made by laminating metal foils such as aluminum on thermoplastic resin sheets are widely used for architecture, furniture, and decoration. In order to improve the adhesion between the resin layer and the metal sheet of these composite plates, there is a method of mixing an adhesive component into the resin layer (Japanese Unexamined Patent Publication No. 5/1989, 7g9). , a method of laminating under pressure with an adhesive layer containing a modified polyolefin interposed therebetween (Japanese Patent Publication No. Shoj; 1f-G (Oe?/No. 1), etc. are known.

[Problem that the invention seeks to solve]

The method of mixing an adhesive component into the resin layer has a problem in that the adhesive component is not fully utilized effectively.

In addition, if an adhesive layer is used, if the adhesive layer is applied on the metal sheets in advance during continuous operation and stored wound up on a roll, the metal sheets may adhere to each other depending on the properties of the adhesive layer or the storage temperature. There is a chance that I will. Therefore, the usual method is to separately prepare the resin that will serve as the adhesive layer as a pre-formed thin film, and then laminate this adhesive layer to the metal sheet just before the metal sort is laminated with the resin layer that will serve as the core material. It is.

[Means for solving problems]

The present invention relates to a method of bonding a metal sotra thermoplastic resin sheet with good adhesiveness without the complicated steps described above. That is, the present invention provides a method for continuously manufacturing a composite plate in which metal sorts are laminated on both sides of a thermoplastic resin sheet, in which a polyolefin layer modified with an unsaturated carboxylic acid or a derivative thereof is used as an adhesive layer on the surface of the metal sheet. The present invention relates to a method for manufacturing a composite board, which comprises using a two-layer composite board having a thermoplastic resin sheet serving as a core material and a resin layer of the same type applied thereon.

Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 shows an example of a side view of the entire process of continuously manufacturing a composite plate according to the present invention, and FIG. 2 shows an example of an enlarged view of a metal sorting cross section.

The numbers in the figure are as follows.

/ Extruder 2, -' Heat pressure bonding roll 3.3' Uncoiler Hiro yl take-up roll 5, S' preheater 6 Thermoplastic resin sheet 7.7' Metal sheet with adhesive layer g Composite plate adhesive layer 70 A metal sheet (7) with a metal sheet adhesive layer applied thereto, with the adhesive layer sides of 7' facing each other and a thermoplastic resin sorting interposed between them, whichever is used to feed the metal sheet to the heat-pressing roll mill, 2'. There is no particular restriction, and examples of examples of materials that can be used include polyethylene, polypropylene, polybutene, polyvinyl chloride, polystyrene, polyamide, polycarbonate, etc. From the viewpoint of extrusion moldability, polyethylene, polypropylene,
It is preferable to use a polyolefin synthetic resin such as polybutene.

The material is supplied to the compression process in either a molten state or a solid state, although this is closely related to the conditions that are appropriately selected depending on the desired thickness of the laminate.

As the metal sheet /θ, a sheet of aluminum, steel, iron, copper, tin, nickel, or an alloy thereof is used. The thickness of the metal sheet ≠ should be 7.5 an or less, and usually a metal sheet of o, o5 to 0.5 is used.

The adhesive layer consists of two layers, q(a), 9), as shown in Figure 1. Layer in contact with metal sheet IQ? For (a), a polyolefin modified with an unsaturated carboxylic acid or a derivative thereof is used. Specifically, unsaturated carboxylic acids include acrylic acid, methacrylic acid, fumaric acid, maleic acid,
Itaconic acid, citraconic acid, etc. In addition, unsaturated carboxylic acid derivatives include acid anhydrides, esters, amides,
Imides, metal salts, etc., such as maleic anhydride, citraconic anhydride, itaconic anhydride, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, glycidyl acrylate, and methacrylate. Grindyl acid, maleic acid monoethyl ester, maleic acid diethyl ester, fumaric acid monomethyl ester, fumaric acid dimethyl ester, itaconic acid monomethyl ester, memeconic acid diethyl ester, acrylamide, methacrylamide, maleic acid monoamide, maleic acid diamide, maleic acid N
-Monoethylamide, maleic acid-NIN-diethylamide, maleic acid-N-motuptilamide, maleic acid-N,N-dibutylamide, fumaric acid monoamide, fumaric acid diamide, fumaric acid-N-monoethylamide, fumare-N , N-diethylamide, fumaric acid-N-motuptylamide, fumaric acid-N,N-dibutylamide,
Examples include maleimide, N-butylmaleimide, N-phenylmaleimide, sodium acrylate, sodium methacrylate, potassium acrylate, potassium methacrylate, and the like. Among these, it is most preferred to use maleic anhydride.

Various known methods can be used to graft the monomer onto the polyolefin. For example, it is carried out by heating the polyolefin and the grafting monomer at high temperature in the presence or absence of a solvent with or without the addition of a radical initiator. Other vinyl monomers such as styrene may be present during the reaction. The amount of the graft monomer grafted onto the polyolefin (hereinafter referred to as graft ratio) is preferably adjusted to be in the range of 10-' to 3% by weight.

The polyolefin may be partially or completely grafted, but from an industrial production point of view, a modified polyolefin with a grafting rate of 10-2 to 6% by weight is produced in advance, and then It is preferable to mix the modified polyolefin with the unmodified polyolefin because the concentration of the graft monomer in the composition can be adjusted appropriately.

Will it be outside the adhesive layer? As (b), the same type of resin as the thermoplastic resin sheet b serving as the core material described above can be used.

In addition, the thermoplastic resin sheet used as the core material is a recycled product,
It is possible to use recycled products in whole or in part, but what about the outer adhesive layer mentioned above? As for (b), a virgin product is usually used so that film thickness can be easily controlled. Also, in cases where the core material is made of high-density polyethylene and the outer adhesive layer is made of low-density polyethylene, the same type of resin according to the present invention may be used.
It is included in

The thickness of the adhesive layer is usually 5 to 1 in total for q(a) and y(b).
The thickness is preferably about 00 μm.

If it is too thin, it will be difficult to apply it uniformly to the metal sheet, leading to a decrease in adhesive strength.

On the other hand, if it is too thick, there will be no particular problem in terms of adhesive strength, but the surface smoothness of the resulting composite plate will deteriorate. Therefore, it is advantageous for the adhesive layer to be as thin as possible in order to maintain sufficient adhesive strength, so it is preferably selected from a range of 0 to 40 μm. Also, is it economically advantageous to make 9G of the two layers thinner? i Preferably 9(a) is 7-3
08m, 9 et al.) are selected from the range of 5-ioom.

In order to apply the two-layer adhesive layer to the metal sort, it is preferable to use the conventional method of laminating them separately or simultaneously.

In order to bond the thermoplastic resin sheet 6 to the metal sheet (7.7') provided with two adhesive layers, at least an adhesive layer is required when the thermoplastic resin sheet is supplied to the pressure roll in a solid state. A portion of the glass, say 9, is heated to an additional temperature above its melting temperature in the preheater, 3'. Usually /2
The temperature is about 0 to 300°C. On the other hand, when the thermoplastic resin sheet is supplied to the pressure roll in a molten state, the adhesive layer wound around the metal sheet does not necessarily need to be molten.

Preheated adhesive layer? (a),? The metal sheets 7, 7' on which (b) is laminated are supplied together with the thermoplastic resin sheet 6 between hot pressure bonding rollers λ1, 2' to perform lamination.

The temperature of the hot pressure roller depends on the type of thermoplastic resin used as the core material and the preheater5. Although it depends on the operating conditions of S', it is usually 100-2!0°C1, preferably 720-20°C.
Selected from the range of 0°C. The heat-pressing roller may be a driven roller or a free roller without driving force.

On the other hand, when the thermoplastic resin sheet is supplied in a molten state, if there is a large difference in temperature between the resin extruded from the extruder and the metal sheet, wrinkles are likely to occur in the metal sort during lamination. It is necessary to heat the metal sheet to prevent wrinkles from forming. Therefore, the heated pressure roller is.

The metal sheet heated to ~200°C is also igo~, 2.2G
Preferably it is preheated to °C.

The metal sheet (7.7') is pulled out from the uncoilers 3, 3' by take-up rollers u, g' under constant tension. The tension at which the metal sheet 7, 7' is bent can be arbitrarily changed by adjusting the driving force of the take-up roll <<, tI', the driving force of the heat-pressing roller -1, the braking force of the uncoilers 3 and 3', etc. is normally controlled to a constant value in the range of 0.2 to 10 kQ/-.

The composite plate sent out from the heat-pressing roller is corrected in planar shape by passing through a cooling roll or staggered rollers as necessary.

〔Effect of the invention〕

According to the present invention, in the process of continuously manufacturing composite plates, there is no need to separately prepare the metal sheet and the adhesive layer.
A metal sheet with an adhesive layer is wound around a pair of uncoilers, and a composite plate can be continuously manufactured using this as a raw material.

Moreover, the adhesion between the metal sort and the synthetic resin sheet is also excellent.

〔Example〕

Next, the present invention will be explained in more detail with reference to examples, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded.

Example/In the apparatus shown in FIG. 1, the resin temperature from the extruder/
Low-density polyethylene continuously extruded at 0°C is passed through three rolls (not shown) to a thickness of 10,100 mm in width.
A polyethylene sheet was obtained. Thereafter, it was allowed to cool naturally to form a solid sheet, which was then supplied to heated pressure rollers 2, 2'.

On the other hand, an aluminum sheet wrapped with an adhesive layer and having a cross section shown in FIG. 2 was fed from uncoilers 3 and 3'. As the aluminum sheet lθ, a surface-smoothed one having a thickness θ, /as and a width of 1000 mm was used. In addition, maleic anhydride is used as the adhesive layer q (a).
Low-density polyethylene (thickness: 10 μm) modified by ppm crafting and low-density polyethylene (thickness: 10 μm) of the same type as the core sheet 6 was used as 7(b). This adhesive layered aluminum sheet) 7.7' is attached to the preheater S.
, 5' to bring the adhesive layer side to a melted state of /(10℃,
The metal side was heated to 733°C and fed to a heated pressure bonding roller.

The driving force of the take-up roll p4' and the braking force of the uncoilers 3, 3' were controlled, and no driving force was applied to the hot pressure bonding roller, and the gap therebetween was maintained at about a huff. As a result, a tension of 2 kg/- was applied to the sialuminium sheet.

The obtained composite plate had a thickness of 0.05 mm, had a good surface smoothness, and had an adhesive strength of t, rkq/inch. , and was supplied in a molten state to a heat-pressing roller roller 2'. The temperature of the hot press roller was set to 10°C.

On the other hand, an aluminum sheet coated with an adhesive layer and having the entire cross section shown in FIG. 2 was supplied from uncoilers 3 and 3'. Aluminum sheet toshite is 0.19m thick and 1 wide.
000 wm was used.

Also, the adhesive layer? As (a), maleic anhydride is about /
000 ppm grafted and modified low density polyethylene (thickness 5 μm)%? As (b), the same type of low-density polyethylene as the core sheet 6 (thickness: 758 m) was used. The aluminum sheets 7 and 7' provided with the adhesive layer were heated to a core temperature of 0° C. in a preheater 5' to melt the adhesive layer and supplied to the hot press roller 2'. The gap between the heating rollers was maintained at approximately 2.9 mm to form a bank of molten resin.

[Brief explanation of the drawing]

FIG. 1 is a conceptual side view showing an example of the apparatus used in the method of the present invention, and FIG. 2 shows a metal sheet 7 with two adhesive layers. A cross-sectional view of ')' is shown.

Claims (1)

[Claims] (1) In a method for continuously manufacturing a composite plate in which metal sheets are laminated on both sides of a thermoplastic resin sheet, a polyolefin layer modified with an unsaturated carboxylic acid or a derivative thereof is applied as an adhesive layer on the surface of the gold layer sheet. A method for manufacturing a composite board characterized by using a two-layer composite board having a thermoplastic resin sheet serving as a core material and a resin layer of the same type applied thereon.