JP2596086B2 - Manufacturing method of composite board - Google Patents

Description

The present invention relates to a method for producing a composite plate having excellent surface smoothness,
More specifically, the present invention relates to a method for producing a composite plate in which an aluminum or iron sheet is laminated on both sides of a thermoplastic synthetic resin sheet.

[Conventional technology]

There are various known composite plates in which a metal sheet is laminated on a thermoplastic synthetic resin sheet. For example, US Pat. No. 3,660,207 discloses that a gap equal to or larger than the thickness of the laminate (the total of the metal layer, the adhesive layer, and the core layer) The material is supplied to a first roll having
A method is described in which the laminate exiting the rollers is passed through a number of zigzag rollers to complete the adhesion and to smooth the laminate.

A large number of staggered rollers need to be arranged in a straight line by adjusting the temperature and the gap between the rollers. A flat laminate cannot be obtained with only a pair of first rollers, and swelling and wrinkles remain. It is clearly stated that a flat laminate can only be obtained after completing a number of zigzag rollers (see in particular column 1, lines 52-56 and the drawing).

JP-A-53-88884 discloses a molten polyolefin sheet having a melting point of 280 ° C. or more and a metal sheet obtained by laminating an adhesive film having a specific composition to a pressure roll and bonding them together under pressure. Further, a method for producing a laminate through a number of cooling rolls arranged in parallel is shown. The purpose here is to obtain a laminate having excellent initial adhesiveness and durable adhesiveness, and the surface smoothness is not particularly described. It is presumed that the molten polyolefin sheet was cooled while passing through a number of cooling rolls arranged in parallel, and became a solid sheet while the sheet was smoothed.

In Japanese Patent Publication No. 61-44065, two metal sheets stretched with a constant tension are preheated, and the preheated metal sheet and the synthetic resin sheet in a molten state are supplied and bonded between heating and pressing rollers. A method of manufacturing a laminated body having excellent surface smoothness by passing between a plurality of rollers arranged in a staggered manner while cooling so that a predetermined bending deformation is imparted to the laminated body is shown. .

Here, the synthetic resin enters a solidified state from a molten state while the laminate passes between a plurality of rollers arranged in a staggered manner, and at this time, the laminate is subjected to a forced bending deformation, so that the tension is relaxed. It is said that wrinkles and waves generated on the surface of the metal sheet disappear as a result. It is described that the tension for expanding the metal sheet is usually controlled to a constant value of 0.2 to 1.5 kg / mm ² (see column 4, lines 21 to 26).

Further, when the resin sheet is supplied in a solid state, so-called longitudinal waves that occur in the direction of extension of the composite plate are small, but so-called transverse waves that occur at the end of the composite plate in a direction perpendicular to the extension direction have been a problem.

[Problems to be solved by the invention]

An object of the present invention is to provide an industrially advantageous method capable of producing a laminate having excellent surface smoothness only by laminating operation using a pair of heat-pressing rollers without performing post-processing correction by a plurality of staggered rollers or parallel rollers. To provide.

[Means for solving the problem]

Major feature of the present invention, in an aluminum sheet having been subjected to thermoplastic adhesive layer 2 kg / mm ² or more, the iron sheet 6 kg / mm ²
An object of the present invention is to instantly bond a metal sheet to a solid thermoplastic synthetic resin sheet without generating wrinkles, waves, or the like by applying the above-mentioned high tension to the heat-pressing roll.

 Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 shows an example of an overall process chart for continuously manufacturing a composite board according to the present invention. The numbers in the figure are as follows.

DESCRIPTION OF SYMBOLS 1 Three rolls 2,2 'Heat-compression roll 3,3' Uncoiler 4,4 'Take-up roll 5 Extruder 6,6' Preheater 10 Melted thermoplastic synthetic resin sheet 11 Solid thermoplastic synthetic resin sheet 12 , 12 'Aluminum or iron sheet 13 Composite plate The thermoplastic synthetic resin sheet is not particularly limited as long as it is used for ordinary extrusion molding. For example, polyethylene, polypropylene, polybutene, polyvinyl chloride, polystyrene, polyamide, polyethylene Terephthalate, polybutylene terephthalate, polycarbonate and the like are used. The thermoplastic synthetic resin sheet 10 extruded in a molten state from the extruder 5 is formed into a sheet having a predetermined thickness by the three rolls 1 having cooling means. The thickness of the sheet is appropriately selected depending on the thickness of the target composite board without any particular limitation, but is usually 1 to 10 mm. In order to produce a composite board having excellent surface smoothness, a solid heat is required. It is important to improve the surface smoothness and thickness accuracy of the plastic synthetic resin sheet 11 itself, and for that purpose, the extrusion speed, resin temperature, take-up speed, etc. are precisely controlled, and three rolls, a steel belt, or the like is used. Correction is preferred.

In bonding the thermoplastic synthetic resin sheet and the aluminum or iron sheet in the present invention, it is necessary to supply the synthetic resin sheet to the heat-pressing roll in a solid state, not in a molten state. When supplied in a molten state, the thickness cannot be controlled with a heating and pressing roll, and only a composite plate having poor surface smoothness can be obtained. The thermoplastic synthetic resin sheet 11 drawn from the three rolls 1 is cooled to room temperature to about 100 ° C. and supplied as a solid sheet to the heat press roller. In FIG. 1, the operation of the extruder 5 and the heating / compression bonding step are connected as a continuous step. In some cases, the solid sheet 11 drawn from the three rolls is once wound around a winding roll, and the extrusion step is performed. And the thermocompression bonding step can be divided. As a result, the process management (startup, troubleshooting, etc.) of both processes can be facilitated.

Metal sheets 12, 12 'made of aluminum or iron
Is drawn out from the uncoilers 3, 3 ', is preheated to a predetermined temperature by preheaters 6, 6', and is supplied to the heat-pressing rollers 2, 2 '.
The preheating temperature is sufficient to melt the thermoplastic adhesive layer applied to the metal sheet. For example, when the adhesive layer is a polyolefin resin, it is heated to about 120 to 150 ° C.

In the present invention, a thermoplastic adhesive layer is applied to a metal sheet and this is adhered to a solid thermoplastic resin sheet. Here, ethylene-acrylic acid copolymer is used as the thermoplastic resin used for the adhesive layer. Copolymers, ethylene-vinyl acetate copolymers, ethylene-glycidyl acrylate copolymers, ethylene-maleic anhydride copolymers, unsaturated carboxylic acids of polyethylene, or graft-modified products of anhydrides thereof.

The adhesive layer may be preliminarily laminated on a metal sheet, or as shown in FIG. 2, thin film 14, 14 'to be an adhesive layer formed in advance is prepared,
The adhesive layer may be simultaneously formed between the decoilers 3, 3 'and the preheaters 6, 6'.

The thickness of the adhesive layer is usually 5 to 100 μm, preferably 10 to 80
μm. If it is too thin, it is difficult to perform uniform application and causes a decrease in adhesive strength. On the other hand, if the thickness is too large, it is not economically preferable, and the surface smoothness of the obtained composite board deteriorates.

As the metal sheet, aluminum or iron foil is used, and any of these may include an alloy containing aluminum or iron as a main component, for example, aluminum, magnesium alloy, aluminum, silicon alloy, stainless steel, or the like.

The thickness of the sheet is usually in the range of 0.01 to 0.5 mm, and is used after subjecting to a surface treatment such as a degreasing treatment according to the purpose.

A major feature of the present invention is that a metal sheet (1 in FIG. 1) is supplied to a heat-press roller.
2,12 ') is to apply a large tension exceeding a specific value.

That is, 2 kg / mm ² or more for aluminum, 6 for iron
Apply tension of kg / mm ² or more. The tension is controlled by applying a large braking force to the decoilers 3, 3 'while taking up the take-up rolls 4, 4'.
This is performed by applying a larger driving force. The tension is selected from a range that is not less than a specific value and does not cause permanent elongation of the metal sheet.

By applying such a tension to the metal sheet, the metal sheet is stretched within the elastic limit, so that distortion and waviness mainly present at both ends of the sheet disappear, and the surface smoothness becomes extremely good. The present invention instantaneously adheres to the solid thermoplastic synthetic resin sheet when the metal sheet is in such a stretched state, and then directly has excellent surface smoothness without undergoing straightening with a zigzag roll or parallel roll. The main point is to manufacture a composite plate.

The thermocompression rollers 2, 2 'may be free rollers having no driving force or driving rollers having a driving force. When the drive rollers 2, 2 'are used, a greater tension can be applied to the metal sheet as a resultant force with the take-up rolls 4, 4'.

The gap between the rollers is kept smaller than the sum of the thickness of the two metal sheets provided with the thermoplastic adhesive layer and the thickness of the solid thermoplastic synthetic resin sheet, and these sheets are heat-pressed while applying a pressing force. It is necessary. Therefore, the roller gap is usually 50 to 2000 μm, preferably 100 to 1000 μm smaller than the sum of the thicknesses described above, and the pressing force is such that the composite plate is not deformed, that is, usually 1 to 100 kg / cm, preferably 5 to 50 kg / cm. Selected from the cm range.

The thermocompression rollers 2, 2 'are necessary not only for pressurization as described above but also for heating the metal sheets 12, 12' and maintaining the thermoplastic adhesive layer at a predetermined temperature in a molten state. is there.

The solid thermoplastic synthetic resin sheet comes into contact with the thermoplastic adhesive layer in the molten state while receiving a pressing force between the heat-pressing rollers, and the extremely thin surface portion instantaneously heats up to the molten state. .

As a result, the metal sheet is heat-welded on both sides of the solid thermoplastic synthetic resin sheet, and is subsequently pulled out under tension by a take-off roll while being naturally cooled to produce a composite plate.

Therefore, the temperature of the heating and pressing rollers 2, 2 'needs to be a temperature sufficient to keep the adhesive layer in a molten state, and depends on the preheating state by the preheaters 6, 6', but usually 1
The temperature is selected from the range of 00 to 200 ° C, preferably 120 to 150 ° C. The temperature is controlled to a predetermined temperature by supplying a heat medium to the inside of the heating and pressing roller.

〔Example〕

Next, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the following examples unless it exceeds the gist.

Example 1 The apparatus shown in FIG. 1 was used. Low-density polyethylene was continuously extruded from an extruder 5 at a resin temperature of 220 ° C. and passed through a mirror-finished three rolls 1 to obtain a polyethylene sheet having a thickness of 1.8 mm and a width of 1220 mm. The sheet was controlled to a high degree of thickness accuracy (± 0.02 mm) by three rolls, and then allowed to cool naturally and supplied as a solid sheet (40 ° C.) to a hot press roller.

On the other hand, an aluminum sheet provided with a thermoplastic resin adhesive layer was supplied from the decoilers 3, 3 '. Aluminum sheets 12, 12 'have a surface smoothness of 0.1mm thickness and width
The thing of 1220mm was used. The thermoplastic adhesive layer was modified by grafting 500 ppm of maleic anhydride onto an aluminum sheet. Low density polyethylene (thickness 10μm)
And unmodified low-density polyethylene (thickness 10μ)
Two adhesive layers subjected to m) were used.

The aluminum sheet was heated by the preheaters 6, 6 ', and the adhesive layer side was melted at 140.degree. C. and the metal side was set at 133.degree.

The driving force of the take-up rolls 4, 4 'and the control force of the decoilers 3, 3' were controlled, and the gap was maintained at about 1.7 mm without applying a driving force to the heating and pressing rollers 2, 2 '. Thus, a tension of 21.2 kg / mm ² was applied to the aluminum sheets 12 and 12 ′.

The obtained composite board is 2.0 mm thick, and its adhesive strength is
8.5 kg / inch, surface smoothness was extremely good, and no wrinkles or waves were observed by visual observation. FIG. 3 (broken line) shows a chart diagram in which a transverse wave at 5 mm from the end in the extending direction was measured for a part (1000 mm in length) of the obtained composite plate.

Comparative Example 1 In Example 1, the braking force applied to the decoilers 3, 3 'was reduced, and the tension of the aluminum sheet was reduced to 1.27 kg / mm ^2.
A composite plate was manufactured in the same manner as in Example 1 except that the above conditions were satisfied.
The adhesive strength of the obtained composite plate was equal to that of Example 1, but was poor in planar smoothness. FIG. 3 (solid line) is a chart showing the measurement of the transverse wave at the end in the same manner as in Example 1.
Shown in

Comparative Example 2 The operation was performed in the same manner as in Example 1 except that the extruder 5 was installed immediately before the heating and pressing rolls 2, 2 ', and the polyethylene sheet was supplied in a molten state at 220 ° C. In the obtained composite plate, four wrinkles (longitudinal waves) were recognized in the longitudinal direction (the same as the drawing direction of the production line, that is, the extending direction), and the surface smoothness was poor.

Example 2 In Example 1, a stainless sheet was used in place of the aluminum sheet, and 8 kg / mm ² was applied to the stainless sheet.
A composite plate was produced in the same manner except that a tension of 5 was applied. The resulting composite plate had an adhesive strength of 15 kg / inch, a very good surface smoothness, and no wrinkles or waves were observed by visual observation. FIG. 4 (broken line) shows a chart in which a transverse wave at 5 mm from the end was measured for a part of the composite plate obtained in the same manner as in Example 1.

Comparative Example 3 In Example 2, the tension of the stainless steel sheet was set to 4.8 kg / mm.
^A composite plate was manufactured in the same manner except that the sample was set to ² . The composite plate here was poor in planar smoothness. FIG. 4 (solid line) shows a chart showing the transverse waves at the ends.

〔The invention's effect〕

As described above, according to the method of the present invention, a composite plate having excellent surface smoothness can be directly obtained without performing a straightening operation.

[Brief description of the drawings]

FIG. 1 is a conceptual side view showing an example of an apparatus used in the method of the present invention, and FIG.
The case where the adhesive layer applied to 2,12 'is separately prepared is shown.
FIG. 3 is a composite plate obtained in Example 1 (dashed line) and Comparative Example 1 (solid line), and FIG. 4 is Example 2 (dashed line) and Comparative Example 3.
(Solid line) shows a transverse wave at the end in the extending direction of the composite plate obtained.

Claims (2)

(57) [Claims] 1. A method for continuously producing a composite plate in which an aluminum sheet is laminated on both sides of a thermoplastic synthetic resin sheet, wherein a solid sheet is used as the thermoplastic synthetic resin sheet, and an aluminum sheet is formed on the sheet surface. Using an aluminum sheet with a thermoplastic adhesive layer, the adhesive layer side of the aluminum sheet is opposed to the aluminum sheet, and the thermoplastic synthetic resin sheet is supplied to the thermocompression roller so that it intervenes between them. , I. Apply a tension of ² kg / mm2 or more to the aluminum sheet, and b. A method for producing a composite plate, comprising: maintaining the thermoplastic adhesive layer applied to an aluminum sheet surface in a molten state. 2. A method for continuously producing a composite board in which an iron sheet is laminated on both sides of a thermoplastic synthetic resin sheet, wherein a solid sheet is used as the thermoplastic synthetic resin sheet, and the iron sheet is provided on the sheet surface. Using an iron sheet with a thermoplastic adhesive layer, the adhesive layer side of the iron sheet faces each other, and it is supplied to the thermocompression roller so that the thermoplastic synthetic resin sheet is interposed between them. , I. Apply a tension of 6 kg / mm ² or more to the iron sheet, and b. A method for producing a composite board, comprising: maintaining the thermoplastic adhesive layer applied to an iron sheet surface in a molten state.