JPH10180958A - Manufacture of heat resistant continuous laminate sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing heat resistant continuous laminate sheet formed of heat resistant fiber cloth and heat resistant fluororesin film and having excellent uniformity. SOLUTION: A heat resistant fluororesin film is superposed on heat resistant fiber cloth adhered with 1 to 50wt.% of heat resistant fluororesin and having METSUKE (weight of cloth per square meter) of 50 to 2,000kg/m<2> , passed through a heating zone set to 320 to 360 deg.C for a retention time of 3min or more while bringing it into pressure contact between belts of a double belt press, and cooled while maintaining the pressure welding state. Or, a heat resistant fluororesin film having lower softening point than that of the film is inserted between the heat resistant fiber cloth without adhering with the heat resistant fluororesin and the heat resistant fluororesin film, and similarly treated to the above.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a heat-resistant continuous laminated sheet having excellent uniformity.

[0002]

2. Description of the Related Art A heat-resistant continuous laminated sheet functions as a composite material by laminating a heat-resistant resin film having characteristics such as gas sealing properties on a heat-resistant fiber cloth having excellent heat resistance and strength. It is suitable for a high-temperature joining member of an exhaust gas or flue gas system, an expansion joint member such as a corrosion-resistant duct system, a corrosion-resistant packing member, a lining member, a non-adhesive conveyance belt member, a membrane structure, and the like.

As the heat-resistant fiber cloth, for example, cloths such as glass fiber, carbon fiber, and aramid fiber are used.
Examples of the heat-resistant resin film include a polytetrafluoroethylene (PTFE) film which is a fluororesin, a polytetrafluoroethylene-perfluoroalkylvinyl ether copolymer (PFA) film, and a polytetrafluoroethylene-hexafluoropropylene copolymer ( FE
Although a P) film or the like is used, in general, a laminated sheet of a glass fiber fabric and a PTFE film is mainly used as the heat-resistant continuous laminated sheet.

However, polytetrafluoroethylene (P
Heat-resistant fluororesins such as TFE) generally have heat resistance, chemical resistance, electrical insulation, specific non-adhesion, non-adhesion,
It has performance such as low friction. Although having such excellent performance, there is a drawback in moldability, and even more, when trying to form a laminate with a glass fiber fabric, a long heating time can be applied due to its unique non-tacky, non-adhesive properties. There was only inefficient production means by the batch press method.

[0005] In order to produce a continuous laminated sheet by this batch press method, joining must be performed while intermittently moving the adhered material to form a continuous sheet. If no non-pressed portion is formed by this method, the pressed portion always overlaps, and only a product that is partially pressed twice is obtained, and there is a problem in uniformity. In addition, there was a concern about pinholes in the PTFE film layer due to double pressing. Furthermore, the sheet is stopped for each press, and the production method is low in productivity.

[0006]

SUMMARY OF THE INVENTION The present invention provides a method for producing a heat-resistant continuous laminated sheet which is excellent in uniformity and which can produce a heat-resistant continuous laminated sheet in a short time without fear of pinholes. It is intended for.

[0007]

SUMMARY OF THE INVENTION The present invention has been made to achieve such an object and has a heat-resistant fluororesin of 1 to 50% by weight attached thereto and a basis weight of 50 to 2000 g.
/ M ² heat-resistant fiber fabric and a heat-resistant fluorine-based resin film are superimposed on each other, and the heating zone set at 320 to 360 ° C.
A method for producing a heat-resistant continuous laminated sheet, characterized in that the heat-resistant fiber fabric and a heat-resistant fluororesin having a basis weight of 50 to 2,000 g / m ² are cooled by maintaining the press-contact state while allowing the sheet to pass for a residence time of at least one minute. While inserting a heat-resistant fluororesin film having a softening point lower than that of the film between the film and the film, the heating zone set at 320 to 360 ° C. is kept for 3 minutes or more while pressing and pressing between the belts of a double belt press machine. A heat-resistant continuous laminated sheet, wherein the sheet is cooled while maintaining a pressure contact state.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. As the heat-resistant fiber cloth used in the present invention, for example, cloth such as glass fiber, carbon fiber, and aramid fiber can be used. As the structure of the fabric, plain weave woven from yarn, satin weave, twill weave, crochet weave, leno weave, knitted fabric, etc., woven from roving, knitted roving cloth or knit, Non-woven fabrics such as short fiber mats such as chopped strand mats and surface mats and long fiber mats such as diamond mats and swirl mats can also be used.

The basis weight of the heat-resistant fiber fabric is 50 to
Those having a range of 2000 g / m ² can be used. If the basis weight is 50 g / m ² or less, the thickness of the heat-resistant fiber fabric is insufficient,
Good adhesion cannot be achieved. On the other hand, at 2000 g / m ² or more, since the heat-resistant fiber fabric itself has heat insulating performance,
Heat conduction is poor at the time of bonding to one or both sides with a heat-resistant fluorine-based resin film, and the desired adhesion performance cannot be obtained even if the heating temperature in the heating zone is high and the residence time is long.

As the heat-resistant fluororesin film used in the present invention, polytetrafluoroethylene (PTF) is used.
E) A film, a polytetrafluoroethylene-perfluoroalkylvinyl ether copolymer (PFA) film, a polytetrafluoroethylene-hexafluoropropylene copolymer (FEP) film and the like can be used. In particular, a heat-resistant fluorine-based resin film having a softening point of 250 ° C. or more can be suitably used. The thickness of the heat-resistant fluororesin film is desirably 0.1 mm or more, and the thickness that can be suitably used is 0.1 to 2 m.
m.

Next, the same heat-resistant fluororesin film as the heat-resistant fluororesin film to be used or a heat-resistant fluororesin particle having a softening point lower than 20 ° C. within 20 ° C. is added to the heat-resistant fiber cloth.
５０50% by weight. When a PTFE film is used as the heat-resistant fluororesin film, the heat-resistant fluororesin to be adhered is PTFE, PFA, or FEP resin.

As an attaching means, a dispersion or solution of a heat-resistant fluororesin is impregnated or surface-coated and dried. If the amount of adhesion is less than 1% by weight, a desired adhesive strength cannot be obtained. On the other hand, if the amount exceeds 50% by weight, it is in an excessively adhered state, and no improvement in adhesive strength is observed, which is not economical.

Instead of attaching the heat-resistant fluororesin particles to the heat-resistant fiber cloth in advance, a heat-resistant fluororesin film having a softening point lower than 20 ° C. than the heat-resistant fluororesin film to be used is used as an intermediate layer. Can be used. When a PTFE film is used as the heat-resistant fluororesin film, the heat-resistant fluororesin used as the intermediate layer is PTFE, PFA, or FEP resin.
Further, it is desirable that the film of the intermediate layer to be used has a thickness of 10 μm or more from the viewpoint of adhesive strength.

Next, a description will be given of a heat pressing process by a double belt press machine. The double belt press machine is composed of two endless belts running in the same direction on opposite sides, and has a material introduction section, a heating zone including a preheating zone, and a cooling zone according to the running direction. The material introduction portion can be formed, for example, by lengthening only the lower endless belts of the two endless belts arranged vertically. Heating zone, endless belt made of metal etc.,
It can be formed by heating this with a heater or the like. For heating the endless belt, a heating means such as heating the endless belt itself with a heater, indirect heating via a driving heat roll for moving the endless belt, or a combination of both can be adopted. . It is desirable that heating can be controlled by detecting the belt temperature. The cooling zone can be formed, for example, by cooling through an endless belt made of metal or the like through a belt supporting roll or the like cooled by passing water or the like.

A heat-resistant fiber cloth to which heat-resistant fluorine-based resin particles are adhered and a heat-resistant fluorine-based resin film are respectively fed out and introduced into a material introduction portion of a double belt press machine. After preheating and heating in a heating zone maintained at a constant temperature while pressing with pressure, cooling and fixing in a cooling zone while maintaining the pressure contact state, and continuously discharging the sheet discharged from the double belt press machine By winding, a heat-resistant continuous laminated sheet can be obtained.

Similarly, when a heat-resistant fiber cloth to which heat-resistant fluororesin particles are not adhered and a heat-resistant fluororesin film are laminated, the heat-resistant fiber cloth and the heat-resistant fluororesin film are interposed. While inserting a heat-resistant fluororesin film with a low softening point so as to become an intermediate layer, each is continuously fed out and introduced into a double belt press machine,
It can be heated and pressed.

The setting of the heating zone temperature and the residence time for joining the heat-resistant fiber cloth and the heat-resistant fluororesin film are performed based on the basis weight of the continuously supplied laminated material or the melting point and thickness of the heat-resistant film. Although it differs in detail depending on the single-area layer and double-sided lamination, after passing between the belts of the heating zone of the double belt press maintained at 320 ° C or more with a residence time of 3 minutes or more, cool and fix. Can be. When the heating zone temperature is lower than 320 ° C., the peel strength of the obtained laminated sheet cannot be ensured even if the residence time is lengthened. If the temperature exceeds 360 ° C., even if the residence time is shortened, pinholes may occur due to the flow of the heat-resistant fluororesin film, which is not preferable.

Next, the residence time will be described. When the residence time is less than 3 minutes, the heat supply to the continuously supplied laminated material cannot keep up, and as a result, the intended peel strength cannot be obtained. On the other hand, when the residence time exceeds 15 minutes, it may be necessary to produce a high-weight laminated sheet or a double-sided laminated sheet. However, when the residence time exceeds 15 minutes, the flow of the heat-resistant fluorine-based resin film generally occurs. There is a concern that pinholes may be caused by this and productivity may be reduced.

Between the belts of the double belt press machine, if necessary, a dial is provided so that the distance between the belts is not smaller than a desired distance so that damage to a heat-resistant fiber fabric such as a glass fiber fabric forming the laminated sheet is reduced. A desired clearance can be obtained by setting such as setting.

In this manner, a heat-resistant fluorine-based resin film is heat-pressed on one or both surfaces of the heat-resistant fiber cloth, and a uniform continuous laminated sheet having a peel strength of 0.5 kg / 25 mm or more can be obtained. Yes [Measuring method is JIS
Measured according to K-6854 (180 ° peeling). ].

According to the continuous laminated sheet of the present invention and the method for producing the same, the core material is made of a heat-resistant fiber fabric, the outer layer is made of a heat-resistant fluororesin film, and the intermediate adhesive layer is also made of a heat-resistant fluororesin film. A heat-resistant continuous laminated sheet made of a material having the same composition or a different composition and having excellent adhesive properties and having a favorable adhesive property with uniformity can be obtained. Extremely high productivity compared to the conventional batch press method,
A heat-resistant long continuous laminated sheet with excellent uniformity can be provided. Further, in the present invention, since the heating zone including the preheating zone and the cooling zone are continuously processed while being sandwiched between the two endless belts, the trouble caused by the heat shrinkage of the heat resistant film is eliminated.

[0022]

The present invention will be specifically described below with reference to examples. Examples 1 to 5 An aqueous dispersion of PTFE particles (about 60 wt% aqueous dispersion) was diluted to various concentrations, and the PTFE particle dispersion was applied to a 1 m wide twill-woven glass fiber fabric having a different basis weight as shown in Table 1 below. After impregnation, squeezed with a mangle and dried, glass fiber fabrics having different amounts of PTFE particles shown in Table 1 were obtained. The amount of adhesion was determined by [(W ₁ −W ₂ ) / W ₁ ] × 100. Here, W ₁ is the weight of the glass fiber woven fabric with PTFE particles attached thereto after drying at 115 ° C. for 1 hour, and W ₂ is the weight of the glass fiber woven fabric with PTFE particles attached after heating at 650 ° C. for 3 hours in an electric furnace to remove the PTFE particles. Weight.

Next, the above-mentioned glass fiber woven fabric having PTFE particles adhered thereto and a PT4 having a thickness of 1.04 m and various thicknesses shown in Table 1 were different.
The FE film and the heating zone were introduced into a double belt press machine having a heating zone length of 8 m, and a heat-resistant continuous laminated sheet was produced through a heating / cooling process at the temperature and residence time shown in Table 1. These had excellent peel strengths shown in Table 1.

Comparative Examples 1 to 4 As shown in Table 1, except that the conditions were changed.
A heat-resistant continuous laminated sheet was produced in the same manner as described above. Comparative Example 1
In Comparative Example 2, the peel strength was insufficient because the glass fiber fabric was thin (40 g / m ² ).
%), And the peel strength is insufficient. In Comparative Example 3, the heating temperature (300 ° C.) is low, and the peel strength cannot be ensured even if the heating time is extended. In Comparative Example 4, the residence time (2 minutes) in the heating zone was short, and even when the heating temperature was increased, the heat supply could not catch up, and as a result, the peel strength was insufficient.

[0025]

[Table 1]

Examples 6-8 Twill-woven glass fiber woven fabrics of 1 m width shown in Table 2 having different basis weights as shown in Table 2, outer layer PTFE films of 1.04 m width shown in Table 2 having different thicknesses shown in Table 2, and intermediate layers shown in Table 2 The PFA film of 1.1m width with different thickness is continuously fed out,
Production and evaluation were performed in the same manner as in Examples 1 to 5. These had excellent peel strengths shown in Table 2.

[0027]

[Table 2]

Examples 9 to 11 Heat-resistant continuous laminated sheets were produced in the same manner as in Examples 1 to 5, except that double-sided lamination was carried out using PTFE films having a thickness of 1.04 m and having different thicknesses as shown in Table 3. However, the peel strength was measured for each side in accordance with JIS K-6854 (180 ° peel), and the average value of both sides was obtained. These had excellent peel strengths shown in Table 3.

[0029]

[Table 3]

Examples 12 to 13 The two-sided lamination was performed using a PTFE film having a thickness of 1.04 m having a different thickness as shown in Table 4 and a PFA film having a thickness of 1.1 m having a different thickness as shown in Table 4 as an intermediate layer. Heat-resistant continuous laminated sheets were manufactured in the same manner as in Examples 6 to 8. The peel strength was indicated by an average value on both sides. These had excellent peel strengths shown in Table 4.

[0031]

[Table 4]

Examples 14 to 15 An aqueous dispersion of PTFE particles (about 60% by weight aqueous dispersion) was diluted to various concentrations, and PTFE was added to a 1 m wide twill-woven glass fiber fabric having a different basis weight as shown in Table 1 below. A heat-resistant continuous laminated sheet was produced in the same manner as in Examples 1 to 5, except that after being applied on one side, it was dried in a dryer and then wound up to obtain a glass fiber fabric coated with PTFE particles. These had excellent peel strengths shown in Table 5.

[0033]

[Table 5]

Examples 16 to 20 An aqueous dispersion of each of PTFE, PFA and FEP particles (about 60
Wt.% Aqueous dispersion) to various concentrations, impregnating the above resin dispersions into a 1 m-wide twill woven glass fiber fabric or a carbon fiber fabric having a basis weight of 1000 g / m ² , and then adhering resin after drying. Was squeezed with a mangle so as to be 15%, dried with a drier, and wound up to obtain various resin-adhered heat-resistant fabrics. The obtained woven fabric and a 0.3 mm PTFE film were layered in one area, and a heat-resistant continuous laminated sheet was produced in the same manner as in Examples 1 to 5, and evaluated.

[0035]

[Table 6]

Examples 21 to 22 An aqueous dispersion of the same resin particles as the heat-resistant film was impregnated into a 1 m-wide twill-woven glass fiber fabric having a basis weight of 1000 g / m ² , and the resin adhesion after drying was reduced to 15%. After squeezing with a mangle and drying with a drier, winding was performed to obtain various impregnated heat-resistant fabrics. The obtained woven fabric was layered in one area with various heat-resistant films of 0.3 mm, and heat-resistant continuous laminated sheets were produced in the same manner as in Examples 1 to 5, and evaluated.

[0037]

[Table 7]

Example 23 A 1 m-wide twill-woven glass fiber woven fabric having a basis weight of 500 g / m ² , an outer layer having a PFA film of 300 μm, and an intermediate layer having a softening point lower than that of the resin having an outer layer of 12.5 μm, An FEP film composed of a resin component having good compatibility was continuously fed out, and a heat-resistant continuous laminated sheet was manufactured and evaluated in the same manner as in Examples 1 to 5.

[0039]

[Table 8]

[0040]

As is clear from the above description, according to the present invention, it is possible to provide a method for producing a heat-resistant continuous laminated sheet composed of a heat-resistant fiber and a heat-resistant film and having excellent uniformity. It is.

────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁶ Identification code FI B29K 105: 06 B29L 9:00 (72) Inventor Yuji Kadokawa 2-12-9 Shiba-Daimon, Minato-ku, Tokyo Unitika Kagurasufibre Co., Ltd. Tokyo Branch Office (72) Inventor Hiroyasu Koizumi 45 Unit 2 Uji Kozakura, Uji City, Kyoto Prefecture Inside Unity Kaglass Fiber Co., Ltd. Kyoto Plant

Claims (2)

[Claims] 1. A heat-resistant fluororesin film on which a heat-resistant fluororesin of 1 to 50% by weight is adhered and which has a basis weight of 50 to 2,000 g / m ² is superimposed on a heat-resistant fluororesin film. 320 ~
A method for producing a heat-resistant continuous laminated sheet, characterized in that the sheet is passed through a heating zone set at 360 ° C. for a residence time of 3 minutes or more, and is cooled while maintaining a pressed state. ^2. A double belt, wherein a heat-resistant fluororesin film having a softening point lower than that of the heat-resistant fluororesin film is inserted between a heat-resistant fiber cloth having a basis weight of 50 to 2000 g / m ² and a heat-resistant fluororesin film. Manufacturing a heat-resistant continuous laminated sheet characterized by passing through a heating zone set at 320 to 360 ° C. for a residence time of 3 minutes or more while pressing and pressing between belts of a press machine, and cooling while maintaining a pressed state. Law.