JP2003320635A - Method for manufacturing laminate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a novel laminating method which can solve problems observed in a conventional impregnating method and a laminating method using rolls such as, for example, mold releasability of rolls, damage of a film or a sheet to be laminated, adhesion of a foreign matter or the like. <P>SOLUTION: A method for manufacturing the laminate comprises the steps of superposing a laminating material on a base material; heating the laminating material from an outside, for example, by a hot blast or a radiant heat from the outside while holding between the base material and the laminating material in a pressure reduced state, and laminating the laminating material on the base material. <P>COPYRIGHT: (C)2004,JPO

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 laminate, and more particularly to an improved method for producing a laminate which comprises laminating a laminating material on a substrate by heating.

[0002]

2. Description of the Related Art As a method for laminating a fluororesin on a substrate, a method for heating a fluororesin film or sheet to press-bond it to one or both sides of the substrate, a method for coextruding a molten fluororesin with the substrate, and a fluorine There is a method in which a resin dispersion is applied to a base material (by dipping, spraying or the like) to impregnate the base material with a fluororesin. The substrate is mainly formed of an inorganic material, for example, glass fiber, carbon fiber,
Examples include cloths of inorganic fibers such as aramid fibers, knits, and wire nets using metal wires. Further, an organic material such as a cloth or knit of aramid fiber having excellent heat resistance can be used as the base material.

However, since the fluororesin has a higher specific gravity than other resins and is liable to generate static electricity, it is difficult to handle, and each of the above-mentioned laminating methods has problems. For example, in the impregnation method, it is necessary to appropriately select the viscosity of the dispersion, the fluororesin concentration in the dispersion, the kind of the surfactant used for dispersion, etc. in order to obtain a laminated body having a uniform thickness. Further, some surfactants have an odor, and it is necessary to take measures against the odor when the impregnated product is dried.

In the case of a method of laminating a film or sheet on a substrate by using a roll, particularly in double-sided laminating, releasability from the roll is the greatest problem. Also, since the melting point of the fluororesin is high, it is necessary to use a roll with good heat resistance, but due to the nature of the heat medium (silicone, naphthalene, etc.) currently used to optimize the temperature distribution of the roll, Has a heat resistance limit of about 400
It is said that the temperature is 0 ° C, which is insufficient to sufficiently melt and laminate the fluororesin. Further, when the molten fluororesin film or sheet is laminated on a substrate such as a wire net with a roll, the film thickness becomes thin on the metal wire, the uniformity of the laminated fluororesin film or sheet is impaired, and the film or The sheet is easy to tear. There is also a problem that foreign matter on the roll surface adheres to the surface of the laminate. Further, if the roll clearance is not uniform, or if the roll is distorted or bent, the thickness of the laminate becomes uneven.

In addition, in any of the above-mentioned conventional laminating methods, as the size of the laminated body becomes larger, the device becomes larger and the cost for installing the device becomes enormous.

[0006]

The problem to be solved by the present invention is to provide a novel laminating method which solves the problems found in the above-mentioned impregnation method and laminating method using a roll.

[0007]

According to the present invention, the above-mentioned problems are solved by heating a laminated material from the outside while superposing the laminated material on a substrate and keeping a reduced pressure between the substrate and the laminated material. ,
This is solved by a method for manufacturing a laminated body, which comprises laminating a laminating material on a base material.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION As the laminate material used in the present invention, any material can be used as long as it becomes flexible by heating and can be fused. For example, any polymer material can be used, from a general-purpose resin having a melting point of about 80 ° C. to a fluororesin having a melting point of 327 ° C. or more such as polytetrafluoroethylene (PTFE). Especially, as the fluororesin, P
TFE, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), ethylene-tetrafluoroethylene copolymer (ETFE), ethylene-
From transparent fluororesins to translucent or opaque fluororesins such as hexafluoropropylene copolymer (FEP) and polyvinylidene fluoride (PVDF) can be used in the method of the present invention.

When it is necessary to color the laminate, a color film may be used as the laminate material. Alternatively,
A transparent laminated material may be used, and the color film may be sandwiched between the base material and the laminated material. In this case, since the laminated material comes into close contact with the base material due to the reduced pressure, the position of the sandwiched color film does not shift, so that the pattern can be formed faithfully.

When a laminate having excellent abrasion resistance is required, an inorganic filler reinforcing agent such as glass fiber or carbon fiber can be added to the laminate material. In addition, when the foreign matter adhesion prevention property and the antistatic property on the surface of the laminate are required, a conductive additive such as carbon or graphite may be added to the laminate material.

As the base material, a base material used in conventional laminates and formed mainly of an inorganic material, for example,
Inorganic fiber cloth such as glass fiber, carbon fiber, and aramid fiber, knits, and wire mesh using metal wires can be used. When the base material is made of a magnetic material, the base material can generate heat by electromagnetic induction, and thus the laminate can be used as a planar heating element or a film heater. Alternatively, the substrate can be made of exothermic material.

In the laminating method of the present invention, since the space between the base material and the laminating material is depressurized, when the laminating material is heated to be softened, the laminating material is fused to the base material by the depressurization. . Therefore, in the laminating method of the present invention, it is preferable that the laminating materials are laminated without applying any external force (a force other than the force generated by decompression). However, in order to promote fusion, pressure may be applied from the outside by means such as a roll. The degree of depressurization and the heating temperature are determined by the melting point and thickness of the laminated material (film or the like), the number of laminated layers, and the like. For example, 25
In the case of laminating two μm-thick films, it is desirable to reduce the degree of reduced pressure or to set the heating temperature to a relatively low temperature near the melting point. On the other hand, 1000 μm
In the case of laminating two thick films, it is desirable to set the heating temperature to a temperature relatively higher than the melting point or to increase the decompression degree. It is desirable to adjust the heating rate, for example, the flow rate of hot air, depending on the thickness of the film. This is because if the material is heated above the melting point of the laminated material, the strength is extremely reduced, and a thin laminated material may be broken.

The laminated material may be of any shape and size as long as reduced pressure can be applied, but preferably, except where the reduced pressure is applied, the laminated material and the substrate are shielded from the outside. Is preferably provided. For example, two films or sheets of laminated material are superposed and the perimeter is sealed except at the portion where vacuum is applied. Alternatively, the base material may be arranged on the planar gas impermeable member, the laminated material may be arranged so as to cover the base material, and the periphery of the laminated material may be sealed in the gas impermeable member. For sealing, the periphery of a film or sheet of a laminated material may be heat-sealed, or an adhesive tape or the like may be attached to the periphery.

The heating may be performed in any manner, but preferably, the heating is started from the position farthest from the place where the reduced pressure is applied, and the heated place is moved toward the place where the reduced pressure is applied. The moving speed is not particularly limited, but is adjusted so that the laminated material is sufficiently fused to the base material.

The heating means is not particularly limited, but hot air is preferably used as the heat source. Radiant heat from other heating means such as a heater can also be used. In any case, it is preferable that the heating means is used so as not to come into direct contact with the laminated material. According to the method of the present invention, a laminate having a wide range of thickness can be manufactured, for example, the total thickness is 2
A laminated body having a thickness of about 5 μm to 20 mm can be manufactured.
With proper heating, thinner or thicker laminates can be produced.

The laminate produced by the method of the present invention can be used for various purposes. Typical uses are as follows. 1. Roofing materials for buildings, wall materials (for example, structural materials for membrane structures, garage roofs, etc.), snow melting roofs, greenhouse materials (roofs,
Walls, windows, etc.) 2. Roof tarpaulin 3. Indoor / outdoor separation shutter 4. Soundproof (sound insulation) wall 5. Fence, balcony 6. Antenna 7. Flue gas duct or duct 8. Corrosion resistant tank 9. Railway snow melting equipment (for melting points and signals) 10. Sheet heating element, film heater, floor, wall or ceiling heating panel 11. Throw heater 12. Explosion-proof film 13. Print board 14. Building vibration isolator (or device) 15. Car hood 16. Antifouling film

[0017]

EXAMPLES The present invention will now be specifically described with reference to examples, but the present invention is not limited to these examples.

Example 1 As a laminated material, modified PTFE manufactured by Daikin Industries, Ltd.
(M112) 100μm thick film (400mm width x 8
00 mm) was used. On the other hand, SUS304 wire mesh (8 mesh; wire diameter of about 0.54 mmφ) (350 mm square) was fired at 300 ° C. and used as a substrate.

First, a modified PTFE film was spread on a cleaned table so that there were no wrinkles, and SUS304 was placed on half of the modified PTFE film (a portion 400 mm in length from one end).
After placing the wire net, the remaining half of the PTFE film was folded back on it to form a temporary laminate having a three-layer structure. Next, a vacuum suction hole was left in a part of the temporary laminate to hermetically seal the entire circumference of the three-layer structure temporary laminate. Then, using a vacuum pump, the internal space of the film was depressurized to 760 mmHgG from the vacuum suction hole, and the air inside the sealed film was removed to form a precursor laminate having a three-layer structure.

Next, by using two hot air welders heated to 360 ° C., hot air is blown to both surfaces of the end portion (end portion far from the vacuum suction hole) of the precursor laminate while being sucked to modify PT.
The FE film was heated. At this time, the distance between the surface of the precursor laminate and the tip of the welder nozzle was maintained at about 5 to 7 mm. The modified PTFE film became transparent by heating. In that state, the nozzle of the hot-air welding machine was moved toward the vacuum suction hole to weld the entire precursor laminate. The modified PTFE film was in close contact with the wire mesh. After the welder nozzle passed over the film, the film was cooled to obtain a laminate in which the translucent modified PTFE film was laminated on both sides of the wire mesh. No residual bubbles were found inside the film.

Measurement of Peeling Strength of Laminated Body The obtained laminated body was cut into a width of 10 mm, and was then peeled off at a peeling rate of 100 mm / min using an autograph manufactured by Shimadzu Corporation.
A 0 ° peel test was performed. Peel strength is 0.3-0.7kg
It was f / cm. The film sometimes broke during peeling.

Example 2 As a laminated material, PTFE (M manufactured by Daikin Industries, Ltd.
12) 100 μm thick film (400 mm width × 800 m
m) 1 sheet and 50 of PFA manufactured by Daikin Industries, Ltd.
One μm thick film (350 mm square) was used. On the other hand, the same SUS304 wire mesh as used in Example 1 was used as a base material.

First, spread the modified PTFE film on a cleaned table, and then put SUS on the half of the modified PTFE film.
A 304 wire net was placed, and a PFA film was placed thereon, and the remaining half of the modified PTFE film was folded back on the PFA film to form a temporary laminate having a four-layer structure. Next, a vacuum suction hole was left in a part of the temporary laminate to hermetically seal the entire circumference of the four-layer structure temporary laminate. Then, using a vacuum pump, the internal space of the film was depressurized to 760 mmHgG from the vacuum suction hole to remove the air inside the sealed film to form a precursor laminate having a four-layer structure.

Then, as in Example 1, the precursor laminate is heated from one end of the precursor laminate toward the vacuum suction hole,
A laminate in which the wire netting and the film were welded was obtained. No residual bubbles were found inside the film.

Measurement of Peel Strength of Laminate The obtained laminate was subjected to the same procedure as in Example 1 to 18
A 0 ° peel test was performed. Peel strength is 1.3 to 1.46 kgf
It was / cm.

Example 3 As a laminate material, modified PTFE manufactured by Daikin Industries, Ltd.
(M112) 250 μm thick film (400 mm width x 8
00 mm) and one PFA 50 μm thick film (350 mm square) manufactured by Daikin Industries, Ltd. were used. On the other hand, the same SUS wire mesh as used in Example 1 was used as a substrate.

First, spread the modified PTFE film on a cleaned stand, and then apply PFA to half of the modified PTFE film.
The film was placed without wrinkles, and a SUS304 wire mesh was placed on the film, and the remaining half of the modified PTFE film was further folded back onto the film to form a temporary laminate having a four-layer structure.

Next, the entire circumference of the four-layer structure temporary laminate was hermetically sealed while leaving a vacuum suction hole in a part of the temporary laminate. Then, the internal space of the film was depressurized to 760 mmHgG from the vacuum suction hole using a vacuum pump to remove the air inside the sealed film to form a precursor laminate having a four-layer structure.

Then, in the same manner as in Example 1, the precursor laminate is heated from one end of the precursor laminate toward the vacuum suction hole,
A laminate in which the wire netting and the film were welded was obtained. No residual bubbles were found inside the film.

Measurement of Peel Strength of Laminate The obtained laminate was prepared in the same procedure as in Example 1
A 0 ° peel test was performed. Peel strength is 3.5-3.9kgf / c
It was m.

Example 4 As a laminate material, modified PTFE manufactured by Daikin Industries, Ltd.
(M112) 100μm thick film (400mm width x 8
00 mm) and two 50 μm thick films (350 mm square) of PFA manufactured by Daikin Industries, Ltd. were used. On the other hand, glass cloth (coarse) (350 mm square) was baked at 350 ° C. in air, and the glass cloth was impregnated with silicone, dried, and baked to be used as a substrate.

A modified PTFE film is spread on a cleaned table without wrinkles, one PFA film is placed on the half of the modified PTFE film, a 350 mm square glass cloth is then placed, and the remaining one PFA film is placed on the glass cloth. Layered. Then, the other half of the modified PTFE film is folded back and 5
It was a temporary laminate having a layered structure. Next, a vacuum suction hole was left in a part of the temporary laminate to hermetically seal the entire circumference of the five-layer structure temporary laminate. Subsequently, a vacuum pump was used to reduce the pressure inside the film from the suction hole to 760 mmHgG to remove air inside the sealed film to form a precursor laminate having a five-layer structure.

Then, as in Example 1, the precursor laminate is heated from one end of the precursor laminate toward the vacuum suction hole,
A laminate in which the wire netting and the film were welded was obtained. No residual bubbles were found inside the film.

Measurement of Peeling Strength of Laminated Body The obtained laminated body was subjected to the same procedure as in Example 1 to 18
A 0 ° peel test was performed. Peeling occurred at the substrate portion, and the peel strength was 0.6 to 0.8 kgf / cm.

Example 5 PFA film AF-0100 manufactured by Daikin Industries, Ltd.
A product (thickness 100 μm) cut into a width of 400 mm and a length of 80 cm was used as a laminated material. On the other hand, SUS304 wire mesh (8 mesh) (350 mm square) was used as a substrate.

A PFA film is spread on a cleaned table and half of it (40 cm) is covered with SUS304 wire mesh,
The other half of the film was folded back to form a temporary laminate having a three-layer structure. Next, leave a vacuum suction hole in a part of the temporary laminate 3
The entire circumference of the layer structure temporary laminate was hermetically sealed. Then, using a vacuum pump, the internal space of the film is moved from the vacuum suction hole to 7
The pressure was reduced to 60 mmHgG to form a precursor laminate having a three-layer structure.

A hot air welder (manufactured by Leister Co., Switzerland) was used to blow hot air at 360 to 370 ° C. to both sides of the end of the laminate, which was the furthest from the vacuum suction holes of the precursor laminate, to make the film completely transparent. The mixture was heated and melted until it was heated, and while maintaining this state, the hot air welding machine was moved toward the vacuum suction hole to fuse the entire precursor laminate.

When a peeling test was conducted in the same manner as in Example 1, the peeling strength was 0.8 to 1 kg / cm, but most of the film broke. That is, the film and the wire mesh were firmly bonded.

Example 6 PFA film AF-0500 manufactured by Daikin Industries, Ltd.
(Thickness 500 μm) cut into a width of 400 mm and a length of 80 cm is used as a laminated material, and SUS304 wire mesh (30
A laminate was produced in the same procedure as in Example 5 except that (mesh) (350 mm square) was used as the base material. The PFA film which became transparent by heating entered into the sucked wire mesh. The film surface had relatively few irregularities, and a good laminate was obtained. A 180 ° C peeling test was performed in the same procedure as in Example 1. Peel strength is 6.3-7.5kgf / cm
Met. Most of the test pieces broke.

Example 7 As a laminate material, modified PTFE manufactured by Daikin Industries, Ltd.
(M112) 0.5mm thick film (400mm width x 80
cm) and two PFA films AF-0100 (350 mm square) manufactured by Daikin Industries, Ltd. were used. on the other hand,
SUS304 punching metal plate (thickness 0.3 mm; 35
0mm square; about 39000 holes with a diameter of 0.5mmφ) 1
Sheets were used as substrates. Denatured P on a cleaned table
Spread out the TFE film, and lay one PFA film, punching metal plate and the other PFA film in this order on half of the modified PTFE film, then PTFE
The other half of the film was folded back to form a temporary laminate having a five-layer structure.

Next, the entire temporary laminate was hermetically sealed while leaving a vacuum suction hole in a part of the temporary laminate, and the internal space of the film was depressurized from the vacuum suction hole to 760 mmHgG using a vacuum pump. Then, using a hot air heater at 360 to 380 ° C., the film end portion on the opposite side of the vacuum suction hole was heated from both sides. By heating, the modified PTFE film became transparent. In addition, the melt viscosity of the film was lowered and the resin entered the 0.5φ hole of the punching metal. At the same time, the hot air heater was sequentially moved toward the vacuum suction hole to fire the entire corner of the temporary laminate to form a laminate using the punching metal plate as a base material.

The resin entered the holes of the punched metal plate, and the films on the front and back were bonded through the holes to obtain a single laminate having a five-layer structure. In this case, if the SUS plate is subjected to blast treatment or surface treatment using a primer or the like, the adhesiveness of the fluororesin (PTFE, PFA, etc.) to SUS is further improved.

Example 8 As a laminated material, a modified FEP film (NF-0500) manufactured by Daikin Industries, Ltd. and having a thickness of 500 μm (4
One piece (00 mm width x 80 cm) was used. On the other hand, one piece of glass cloth (thickness 0.3 mm) (350 mm square) was used as a substrate.

The FEP film was spread on a cleaned table, a glass cloth was placed on one half of the FEP film, and the other half of the PTFE film was folded back on it.
A three-layer temporary laminate was formed.

Next, the outer periphery of the temporary laminate was hermetically sealed while leaving a vacuum suction hole in a part of the temporary laminate, and the internal space of the film was depressurized to 760 mmHgG from the suction hole using a vacuum pump. Then, using a hot-air welding machine, heat both sides of the film end portion on the opposite side of the vacuum suction hole with hot air of 360 to 380 ° C., gradually checking the welding machine while confirming that the FEP film became transparent. Moving toward the suction hole, a laminate was formed. Peel strength is 7-8 kgf / cm,
The film broke in most of the test pieces.

Example 9 One aluminum plate (thickness 1.5 mm; 400 mm square), 300 ° C.
Glass cloth impregnated with silicone after heat treatment (35
1 x 0 mm square, PFA film made by Daikin Industries (thickness 5
0 μm; 5-7% stretched; 340 mm square) 1 sheet, and modified PTFE (M112; 5-7%) manufactured by Daikin Industries, Ltd.
One (stretched) 100 μm thick film (400 mm square) was prepared. First, clean the aluminum plate surface with acetone,
A glass cloth is placed on it, and a PFA film and a PTFE film are stacked on it to form a temporary laminated body of four layers,
The aluminum plate and PTFE were sealed with the vacuum suction hole left.

Using a vacuum pump, the space inside the temporary laminate was decompressed to 760 mmHgG from the vacuum suction hole to form a precursor laminate. While vacuum suction is further performed, heating is performed from both sides of the end farthest from the vacuum suction hole of the camouflage laminate with a hot air welding machine at 370 ° C., and the heated portion is moved toward the vacuum suction hole to heat-weld the fluororesin film. . Then, the aluminum plate was removed to obtain a laminate in which the PFA film and the PTFE film were laminated on one surface of the glass cloth. In addition,
It was confirmed that, when the unevenness of the base material is small at the time of stacking, the use of the stretched film can absorb the expansion generated at the time of heating, and the wrinkle occurrence rate of the stack is significantly reduced.

[0048]

EFFECT OF THE INVENTION According to the laminating method of the present invention, it is possible to laminate (laminate) a heating tool such as a heating roll without directly contacting the laminated material, for example, a fluororesin film or sheet. In addition, the laminate is less likely to be contaminated. It is possible to pressurize the laminate after heat lamination. Since the laminated material does not come into contact with the heating source and the pressure source, the problem of mold release does not occur. Since heating can be performed indirectly, a wide and long laminated product can be easily manufactured. Since pressure is not applied, the thickness variation of the laminate is very small. Since heating is performed at the melting point of the laminated film or higher, delicate temperature control is not required. When the base material is made of fibers, film breakage does not occur on the fiber portions. Since no roll is used, wrinkles due to center deviation do not occur. Since the base material does not come into contact with other articles before and after the lamination of the laminating material, misalignment of the wire mesh, the glass cloth, etc., which is the base material, does not occur. Since the layers are laminated while suctioning under reduced pressure, no bubbles remain inside the laminated body.

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 4F100 AB04 AK17 AK18 AL06 AR00B                       AT00A BA02 BA03 BA06                       DC16 EJ24 EJ42 EJ43 GB07                       GB16 GB31 GB51 JK06 JL02                       JL11

Claims (8)

[Claims] 1. A laminate characterized by stacking a laminate material on a base material, and heating the laminate material from the outside while maintaining a reduced pressure between the base material and the laminate material to laminate the laminate material on the base material. Body manufacturing method. 2. The method for producing a laminated body according to claim 1, wherein the laminated materials are laminated without applying an external force. 3. The method for producing a laminated body according to claim 1, wherein the space between the laminated material and the base material is shielded from the outside except where the reduced pressure is applied. 4. The method for producing a laminate according to claim 3, wherein the heating is started from a position farthest from the portion to which the reduced pressure is applied and is directed toward the portion to which the reduced pressure is applied. 5. The method for producing a laminate according to claim 1, wherein the laminate material is heated without bringing a heating tool into contact with the laminate material. 6. The method for producing a laminate according to claim 5, wherein heating is performed with hot air. 7. The method for producing a laminate according to claim 1, wherein the laminate material is a fluororesin. 8. The method for producing a laminate according to claim 1, wherein heating is performed at a temperature equal to or higher than the melting point of the laminate material.