JPH0611529B2 - Method for manufacturing flame-retardant heat-resistant sheet - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing a sheet material which is excellent in flame retardancy and heat resistance, and is also excellent in antifouling and weather resistance.

Conventional technology Conventionally, a fibrous base cloth made of polyester fiber (melting point 255 to 260 ° C), polyamide fiber (melting point 215 to 260 ° C), etc., and thermoplastic resin such as polyvinyl chloride (PVC) (heat resistant temperature 66 to 79 ℃), polyurethane (heat-resistant temperature 90 ~ 120
℃), acrylic resin (heat-resistant temperature 60-88 ℃), polyethylene (heat-resistant temperature 80-120 ℃), polypropylene (heat-resistant temperature)
120-160 ℃), polyamide (heat-resistant temperature 80-150 ℃) or polyester (heat-resistant temperature 120 ℃) is used as a sheet material. In this case, the melting point of the fibrous base cloth is relatively low, and even as a coating material to be coated on the fibrous base cloth, from the viewpoint that the fibrous base cloth must withstand the heat during the coating process, Low resins such as those mentioned above have been used. However, in recent years, these sheet materials are often used, for example, in firefighter clothes, heat-resistant clothing, building materials, etc., and in order to maintain safety from fires, burns, and other thermal disasters, they are non-combustible and difficult to burn. The demand for flame-retardant materials is increasing, and flame-retardant heat-resistant sheet materials are being developed. However, even in such a case, even if a fibrous base cloth is conventionally made of a heat-resistant material, the covering material for covering the fibrous base cloth is a conventional PVC, polyurethane, or ethylene-vinyl acetate copolymer. Most of them use (EVA), etc., and they have not yet reached sufficient heat resistance and flame retardancy.

Therefore, recently, a flame-retardant tent film material obtained by coating a base cloth with PTFE (polytetrafluoroethylene) has been developed and used. However, this is manufactured by dipping PTFE having a concentration of 60% and a viscosity of 20 centipoise as a dispersion and baking coating at a high temperature (about 400 ° C or even 350 ° C to 500 ° C). And
Since such immersion and high temperature firing are performed, the processing speed is about 30 cm.
/ Min, and if a sufficient coating thickness is formed at one time, sagging, mud-like cracks, foaming, etc. will occur on the coated surface, and there will be performance negative aspects such as cracking of the coating. Since the operation was repeated, there was a problem in processing. Further, since a high temperature is applied during the processing as described above, the flame-retardant sheet material has a negative effect on the strong side, and the adhesive force also causes an unfavorable result.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention The inventors of the present invention have studied how to eliminate these drawbacks, form a fluororesin film in advance, and apply the flame-retardant heat-resistant group through the adhesive layer. It was found that when it is attached to a cloth, these drawbacks are eliminated and it is extremely effective. As a result of further study, in order to maintain the adhesive strength (peel strength) and the strength, in particular, in order to reduce the deterioration of the base cloth due to high temperature processing heat and to maintain the strength, the melting point of the fluorine-based resin film is 280 ° C or less, Preferably, it is selected to be 250 ° C or lower, and the treatment temperature is at least 350 ° C, preferably 300 ° C or lower, and
Preferably, when melt-adhered at 270 ° C. or lower, the flame-retardant heat-resistant base fabric is not deteriorated in strength, the film is not deteriorated, and sufficient adhesive strength is imparted without diminishing the effect of the adhesive substance. They have found the present invention and completed the present invention.

Means for Solving the Problems According to the present invention, there is provided a method for producing a flame-retardant heat-resistant sheet having excellent weather resistance and antifouling property, which is a fluorine-based resin having a melting point of 280 ° C. or less. At least one surface of a flame-retardant heat-resistant base cloth made of an organic fiber cloth having a melting point or a thermal decomposition point of 300 ° C or higher is melt-bonded by melting the film on at least the sticking surface through an adhesive substance layer. The feature is that they are integrated with each other.

To further explain the present invention in detail, the flame-retardant heat-resistant base fabric used in the method of the present invention is composed of a flame-retardant heat-resistant fiber cloth, and such a cloth has a melting point or a thermal decomposition point of 300. A knitted woven fabric or non-woven fabric made of organic fibers having a temperature of ℃ or higher is used. Examples of useful polymers for such fibers include:
There are some as shown in the table below.

Of these, polymetaphenylene isophthalamide and polyparaphenylene terephthalamide are particularly common, and "HM-50" manufactured by Teijin Limited can be used as a para-aramid fiber other than the above.

Aromatic polyamides useful in such fibers also include at least 50 mol% of the following formulas (I) and (II): [In the above formula, Ar ₁ and Ar ₂ represent a divalent aromatic group, and these may be the same or different from each other]. It is preferable to have a main repeating unit. The above formula (I)
And (II), the divalent aromatic group represented by Ar ₁ and Ar ₂ is represented by the following formula: [In the above formulas, A is -O -, - S -, - SO -, - SO 2 -, - C
O -, - CH ₂ - or -C (CH _{3) 2} - to be selected from aromatic residue group preferably represented by the representative]. These aromatic residues may contain an inert substituent such as a halogen, an alkyl group or a nitro group.

Generally, as the aromatic polyamide, the following formula, Those having a repeating unit represented by as a main component are more preferable.

As the heat resistant fiber, in addition to the above, fluorine-based fibers and other fibers can be used as long as they have a melting point or a thermal decomposition point of 300 ° C or higher. In addition, fibers having a lower melting point or thermal decomposition point may be mixed in the base fabric in order to promote adhesion with the fluororesin film to be coated.

The fluorine-based resin film useful in the present invention is preferably a fluorine-containing resin having a heat-resistant temperature of 180 to 260 ° C. and a melting point of 160 to 280 ° C., which is flame-retardant and heat-resistant and has a film-forming property.
Specifically, FEP (tetrafluoroethylene-hexafluoropropylene copolymer For example, PCTFE (polychlorotrifluoroethylene) with an mp of 250 ℃ or less can be used. ) (Mp215 ℃), PVDF (polyvinylidene fluoride) ) (Mp165-180 ° C), PVF (polyvinyl fluoride) ) (Mp200-210 ° C), ECTFE (chlorotrifluoroethylene-ethylene copolymer ) (Mp 245 ° C) or the like is preferably used.

Although the weather resistance of these resins is extremely good, an ultraviolet absorber may be incorporated into these resins for the purpose of protecting the base cloth. Further, it goes without saying that a colorant or other performance-imparting agent may be added.

The coating film made of these resins may be microporous, or may have open or discontinuous cells.

In the present invention, a fluorine-based resin is formed into a film in advance, and at least one surface of this film is melted and adhered onto a base cloth. In this case, even if the base cloth is not heated, it can be stuck if at least one sticking surface of the film is sufficiently melted. However, in order to preferably melt and flow the molten resin between the fibers of the base cloth to strengthen the adhesion, it is preferable to heat the base cloth in advance and, if possible, to heat it to the melting temperature of the fluororesin film or higher. More preferable. The temperature is preferably 50 ° C. or higher, which is the melting point of the fluororesin, but it is not preferable that the temperature is set higher than necessary.

The fluororesin film is attached to the base cloth with an adhesive substance interposed in the middle for the purpose of improving adhesion and durability. The purpose of using this substance is to improve the adhesive force, and it is not necessary to intervene particularly thickly in order to improve the adhesive force. The adhesive substance is not used for forming a film, and therefore a substance known as an adhesive can be used. For example, amino group, imino group, ethyleneimine residue, acrylate containing alkylenediamine residue, acrylate containing aziridinyl group, aminoester-modified vinyl polymer, aromatic epoxy adhesive, amino nitrogen-containing methacrylate polymer, other You may use an adhesive together. Further, it is possible to arbitrarily select a resin having the same quality as the resin constituting the fiber base cloth such as polyamide-imide or polyimide, or an RFL-modified substance. When applying with an adhesive substance such as this, if the processing temperature is 350 ° C to 400 ° C or higher, the properties of these substances are lost and not only the effectiveness as an adhesive is lost, Since the strength of the base cloth may be lowered, it is particularly preferable to select a base cloth base material that can be melted at a temperature of 350 ° C. or lower, and thus a fluorine-based resin film that can be melted at a temperature of 250 ° C. or lower.

The adhesion of the fluororesin film of the present invention may be performed on one side, but it may be applied on both sides to compensate for the low weather resistance of the base fabric, etc. It becomes a mandatory condition.

It is preferable that the fluororesin film is adhered in a state in which a layer is formed instead of including the resin in the entire base cloth. Regarding the relationship between the fluorine-based resin film and the base cloth, the molten resin of the fluorine-based resin film is ingested and adhered to the surface of the base cloth, but it does not seem to penetrate into the entire base cloth. Are preferable in terms of hardness, flexibility, and ease of handling. However, it does not matter if the resin penetrates the entire base cloth. The thickness of the fluorine-based resin film adhered on the flame-retardant heat-resistant base cloth is 5 to 2000 μm, especially 10
It is preferably ˜1500 μm.

Effect of the Invention In the present invention, since the fluorine-based resin film having no defects is uniformly and evenly covered on the surface of the base fabric as described above, unlike the coating by the conventional impregnation sintering process,
It is possible to obtain a flame-retardant heat-resistant sheet which does not cause defects on the surface of the base cloth, effectively protects the base cloth from ultraviolet rays, and has extremely preferable antifouling properties and weather resistance.

Examples The present invention is configured and implemented as described above, and the present invention will be described in more detail below with reference to examples.

Example 1 Aromatic Polyamide (Kepler, DuPont) Fiber Fabric: Thickness 0.12mm Weight 60g / m ² Tensile strength (warp × latitude, kg / 3cm) 130 × 168 Tensile elongation (warp × latitude,%) 3.2 × 3.7 Using this base cloth, after scouring and drying, Heat-set at 350 ° C for 20 seconds, and leave it as it is (Sample I), or add acrylic adhesive (SC-462, Sony Chemical Co.) to Sample I.
Prepare a sample coated on one side in an amount of 30 g / m ² (Sample II), heat each of these samples to 280 ° C, and add PVDF.
(mp180 ° C.) One side of a film (thickness: 50 μm) was heated to 250 ° C. to melt, superpose, and pressure-bonded to prepare samples Ia and II-b, respectively. In addition, in Sample II, P.
A VDF film was prepared by simply adhering one side without melting the VDF film, and this was designated as sample II-c.

The water pressure resistance of the thus obtained composite was well above 1000 mm of water column, which was preferable, and it was sufficiently durable as a flame-retardant heat-resistant membrane material. The physical properties of these sheets were measured as follows.

As can be seen from the above table, it does not decrease much compared to strong machinery, but tends to increase due to the binding force of the adhesive. In peeling strength, since it is a filament woven fabric, the effect of the adhesive substance layer is clear, and the sample II-b for fusion bonding is used.
Was extremely high. Further, this composite sheet was flame-resistant and heat-resistant, had a smooth surface, and had very good weather resistance and antifouling property, and was extremely preferable as a film material for tents.

Example 2 Aromatic Polyamide (Conex, Teijin) Fiber Base Fabric: Thickness 0.23 mm Weight 90 g / m ² Tensile strength (warp × latitude, kg / 3 cm) 70 × 62 Tensile elongation (warp × latitude,%) Using 24 × 25, the same operation as in Example 1 was repeated, A PVDF film was used to attach the base fabric to both the front and back sides. As a result, similar to that of Example 1, it has sufficient waterproofness. The physical properties of these sheets were as follows.

As can be seen from the above table, the tenacity was almost the same as that of the raw machine, and the peeling strength was extremely high for the sample for melt-adhesion, particularly for the sample II'-b adhered with an adhesive. In addition, since the sample II'-b used the spun yarn woven fabric as the base fabric, it was extremely preferable as a material for work clothes having excellent drape, heat resistance and flame retardancy.

The sheet obtained by the method of the present invention may be formed into a tape shape, or may be a sheet cut into a tape shape. For example, this tape can be used by being coated or wound for applications requiring heat resistance and flame retardancy such as electric wires and cables.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-54-139689 (JP, A) JP-A-50-86577 (JP, A) JP-A-54-45386 (JP, A) Actual development Sho-58- 7648 (JP, U) Japanese Patent Sho 63-19337 (JP, B2)

Claims (4)

[Claims] 1. A flame-retardant heat-resistant base fabric made of an organic fiber cloth having a melting point or a thermal decomposition point of 300 ° C. or higher, which is obtained by melting at least the sticking surface of a fluorine-based resin film having a melting point of 280 ° C. or lower. A method for producing a flame-retardant heat-resistant sheet, characterized by comprising melt-bonding and integrating them on one surface via an adhesive substance layer. 2. The method according to claim 1, wherein the adhering surface of the flame-retardant heat-resistant base cloth is preheated. 3. The method according to claim 2, wherein the temperature to be preheated is the melting temperature of the fluorine-based resin film or higher. 4. The method according to any one of claims 1 to 3, wherein the fluororesin film is attached to both sides of the flame-retardant heat-resistant base cloth.