JPS5836111B2 - Manufacturing method for inorganic fiber woven fabric with excellent heat and chemical resistance - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing an inorganic fiber woven fabric to which a tetrafluoroethylene resin thin plate is welded for use in joints of flue ducts and the like.

The calcined tetrafluoroethylene resin thin plate (hereinafter referred to as 4F thin plate) used in this invention is formed into a thin plate by a special molding method similar to metal powder metallurgy, and then further processed into a thin plate, so that no voids occur in the thin plate. (voids) cannot be avoided.

In order to fill these voids, a tetrafluoroethylene perfluoroalkyl vinyl ether copolymer resin or a tetrafluoroethylene hexafluoride ethylene propylene copolymer resin (hereinafter referred to as copolymer resin) was prepared in advance by extrusion molding into a 4F thin plate. This uses a film that is heat-sealed.

When a copolymer film is inserted between a 4F thin plate and an inorganic fiber woven fabric, overlapped, and bonded by heat and pressure, the copolymer resin film becomes fluid due to heating and becomes more fluid than the woven fabric. It begins to flow into the recess.

Therefore, the copolymer resin film is fused only to the part where the 4F thin plate and the inorganic fiber woven fabric are in contact, and at the same time, the
The copolymer resin film is separated from the F thin plate, making it impossible to fill the voids in the 4F thin plate with the copolymer resin film.

If the void filling ζ is insufficient, the product used for sealing gas bodies, etc. will not be able to fully achieve its intended purpose.

By the way, if the gas permeability coefficient is expressed as oxygen (02) Hl, then tetrafluoroethylene resin 1050, tetrafluoroethylene hexafluoropropylene copolymer resin composition is tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer resin. is 750
It can be seen that the copolymer film is clearly superior.

The unit of numerical value is cc/100in”/24
hrs/atr1l/mil.

Tetrafluoroethylene resin has excellent heat resistance and chemical resistance and is widely used in industrial fields, but it is difficult to process because of its strong chemical stability.

Adhesion can be mentioned as one of the problems in processing.

The surface of a tetrafluoroethylene resin molded article is extremely slippery, and it is difficult to adhere other substances to it.

Generally, in order to bond with an engineering adhesive, it is necessary to treat the surface of the tetrafluoroethylene resin with, for example, an ammonia solution of metallic sodium.

The present invention eliminates the complexity of pre-adhesion treatment work, and the manufacturing heating temperature required in the past is around 360°C, which is the melting point of so-called 4F thin plates, 327°C or higher. According to the method, it is possible to fuse the materials through the copolymer resin at a heating temperature of 315° C. or lower.

Since welding is carried out at a temperature below the melting point of the 4F thin plate, the purpose can be achieved without damaging or changing its physical performance.

The low heating temperature makes it easy to manage the heat during work, and furthermore, in this method, the heating time can be completed in a few minutes.

It can also be characterized by suppressing thermal deterioration of the base woven fabric.

The structure of the inorganic fiber woven fabric used for production by this method is not particularly limited, but if a crimped inorganic fiber woven fabric is used, the crimped portion of the inorganic fiber woven fabric and the copolymer resin film Since the contact points are fused, it is possible to integrate the inorganic fiber woven fabric and the 4F thin plate, which have significantly different coefficients of thermal expansion, without sacrificing their respective excellent performance, and it has elasticity, flexibility, and mechanical strength. This is what we offer.

An example of this invention will be shown.

Layer the tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer resin film on the 4F thin plate and heat it for about 35 minutes for several minutes.
The copolymer resin is laminated by heating and pressurizing at 0°C.

The surface of the copolymer resin laminated on the above 4F thin plate is overlapped with an inorganic fiber woven fabric, such as an asbestos woven fabric or a glass woven fabric.

In that state, sandwich it between the upper and lower heating plates to 305°C to 315°C.
Heat and pressurize for several minutes at a temperature of , then remove from the heating plate and leave to cool.

By heating and pressurizing, the contact area between the copolymer resin and the inorganic fiber woven fabric melts and becomes bonded.

The 4F thin plate with copolymer resin that does not come into contact with the inorganic fiber woven fabric is an inorganic fiber woven fabric with a thin tetrafluoroethylene resin plate bonded to it, which has elasticity, flexibility, and mechanical strength and has wrinkles on the surface due to plastic deformation. was gotten.

As shown in the drawing, by overlapping the 4F thin plate 1 and the copolymer resin 2 and applying heat and pressure, the molecules of the copolymer resin 2 enter between the 10 molecules of the 4F thin plate, and the two are fused together.

Next, the copolymer resin 2 is applied to the convex portions 4' of the warp threads 4 of the inorganic fiber woven fabric 3.
and is fused to the convex portion 5' of the weft yarn 5.

The copolymer resin 2 is supported by the 4F thin plate 1 and does not enter the gap 6 between the convex portion 4' and the weft 5.

Therefore, the 4F thin plates are placed in the woven fabric with a space between them, and wrinkles are generated on the surface due to the plastic deformation of the 4F thin plates.

The effects of the present invention are as follows.

(1) Pretreatment of the surface of the tetrafluoroethylene resin, such as treatment with an ammonia solution of metallic sodium, can be omitted.

(2) Since the 4F thin plate and the copolymer membrane are heated and pressurized at 327° C. or higher, they are fused together, filling the voids in the 4F thin plate and reducing gas permeability.

(3) Since the copolymer resin and the woven fabric are fused at a heating temperature of 305° C. to 315° C., thermal deterioration of the base woven fabric can be prevented and thermal temperature control can be easily performed.

(4) The copolymer resin adheres to the convex portions 4' and 5' of the warp and weft of the inorganic fiber woven fabric, but does not enter the void 6 between the convex portion 4' of the warp and the weft 5.

Therefore, the 4F thin plate is separated from the woven fabric by a space, and since the 4F thin plate is made of thermoplastic resin, wrinkles are formed on the surface by plastic deformation to improve elasticity and flexibility.

Furthermore, the inorganic fiber woven fabric bonded with the tetrafluoroethylene resin thin plate obtained by this invention is used for joints of smoke and air ducts, etc., and has excellent chemical resistance, heat resistance, gas permeability, elasticity,
Excellent effects such as flexibility are exhibited.

[Brief explanation of the drawing]

The drawing is an enlarged sectional view showing the state in which the copolymer resin adheres to the 4F thin plate and the inorganic fiber woven fabric when carrying out the present method.

Claims (1)

[Claims] 1 A copolymer resin film 2 of tetrafluoroethylene and perfluorinated alkyl vinyl ether or a copolymer resin film 2 of tetrafluoroethylene and hexafluoride propylene is superimposed on the burnt tetrafluoroethylene resin thin plate 1. Tetrafluoroethylene resin 1
At a temperature of 327° C. or higher, which is higher than the melting point of Stack them together.
The copolymer resin film 2 is fused only to the protrusions 4' of the warp 4 and the protrusions 5' of the weft 5 of the inorganic fiber woven fabric 3 by heating and pressurizing at 305°C to 315°C. A method for producing an inorganic fiber woven fabric having excellent heat and chemical resistance, characterized in that a void 6 is formed between the convex portion 4' of the weft yarn 5 and the convex portion 5' of the weft yarn 5.