JP2000202961A - Flameproof laminated cloth and production thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide flameproof laminated cloth having the high peel strength of base cloth and a laminate layer excellent in heat sealability, flexibility and abrasion resistance, having proper slip properties and free from a pinhole. SOLUTION: A flameproof laminated cloth is constituted by laminating an intermediate layer 3 containing a soft propylene polymer of which the bending modulus measured by JISK 6758 is 800 MPa or less and a fire retardant and a surface layer 4 comprising a propylene/ethylene random copolymer on both surfaces of base cloth 2 knitted by using polypropylene multifilaments as warp and weft yarns. When the surface layer 4 comprising the propylene/ethylene random copolymer is to be laminated on the surface of the intermediate layer 3 after the layer 3 is laminated and cooled, the intermediate layer 3 is cooled by a cooling roll of which the surface temp. is 50 deg.C or higher.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flameproof laminate cloth which is suitably used for a curing sheet for construction and a sheet for wind pipes.

[0002]

2. Description of the Related Art Sheets made of thermoplastic resin, which is usually flammable, are used as curing sheets for safety prevention at building construction sites such as buildings and houses, and air duct sheets for blowing air at tunnel construction sites. It is frequently used, and there is a danger that it will burn due to welding sparks and the like. For this purpose, for example, flame retardant standards are specified in Appendix Table 1 of JIS A8952 “Building Work Sheets”, and various flame retardant treatments are usually performed to pass the standards. . 2. Description of the Related Art Conventionally, a sheet obtained by laminating a polyvinyl chloride film on a woven or knitted fabric using a multifilament yarn such as polyester or nylon has been generally used as a sheet for a flameproof construction or a sheet for a wind pipe. The advantage is that the woven and knitted fabric has sufficient strength, is flexible, and is provided with flame retardancy by a polyvinyl chloride layer. In addition to problems such as generation of toxic gas, and problems such as contamination and smell due to bleeding of the plasticizer, handling was difficult due to the heavy weight and the spreading work at high places. Further, polyvinyl chloride has a problem that it hardens at a low temperature and is difficult to handle, and also becomes brittle and its strength is reduced.

In order to solve such a problem, in recent years,
A flame-resistant laminate cloth in which a polypropylene layer is laminated on a woven or knitted fabric made of a polypropylene multifilament, which has excellent filament formability and does not generate toxic gas, has been tried. However, those obtained by laminating a polypropylene layer on a base cloth made of polypropylene multifilament as the weft of the woven or knitted fabric are inferior in flexibility due to the high flexural modulus of the polypropylene used for the polypropylene layer, and are used as curing sheets and air duct sheets. There is a disadvantage that the handleability is not good in the stretching work at the construction site.If a soft propylene polymer having a low flexural modulus is used for the laminate layer, the abrasion resistance and lubricity of the sheet surface are reduced, and blocking occurs. There was a problem that it was not preferable.

Also, a sheet laminated with a soft propylene polymer layer containing a flame retardant has poor heat sealing properties due to bleeding of the flame retardant during secondary processing such as edge processing and joining of sheets as a problem of the sheet surface. In addition, there is a problem that high peel strength cannot be obtained due to inferior adhesiveness between the base fabric made of polypropylene multifilament and the soft propylene polymer layer.
Therefore, in order to improve the adhesion between the base fabric and the soft propylene-based polymer layer and obtain a high peel strength, the soft propylene-based polymer layer is gradually cooled during lamination to form the soft propylene-based polymer layer on the base fabric. If the soft propylene polymer layer at the opening portion of the base fabric is to be entangled, there is a problem that cooling is delayed and pinholes are generated.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has a base fabric and a laminate layer having high peel strength, excellent heat sealability, flexibility, and abrasion resistance. It is an object of the present invention to provide a flame-resistant laminate cloth having no slip holes and having no pinholes and a method for producing the same.

[0006]

Means for Solving the Problems In order to solve the above problems technically, the present invention provides a JIS K67 on both sides of a woven or knitted fabric using a polypropylene multifilament as a weft.
An intermediate layer containing a soft propylene polymer having a flexural modulus of 800 MPa or less and a flame retardant, and a flame-resistant laminate cloth formed by laminating a surface layer made of a propylene-ethylene random copolymer. This is the gist of 1.

Further, the present invention provides a method for obtaining a flame-resistant laminate cloth of the present invention, wherein a bending elastic modulus measured by JIS K6758 by extrusion lamination on both surfaces of a woven or knitted fabric using a polypropylene multifilament as a weft is 8.
A method for producing a flameproof laminate cloth comprising laminating an intermediate layer containing a soft propylene-based polymer having a pressure of 00 MPa or less and a flame retardant, cooling, and then laminating a surface layer made of a propylene-ethylene random copolymer on the surface thereof. Is the second gist.

Further, the present invention provides a method for obtaining a flame-resistant laminated cloth according to the present invention, wherein JIS K675 is provided on both sides of a woven or knitted fabric using a multifilament made of polypropylene as a weft.
Extrusion lamination in which an intermediate layer containing a soft propylene polymer having a flexural modulus of 800 MPa or less and a flame retardant measured according to 8 and a flame retardant is laminated and cooled, and a surface layer made of a propylene-ethylene random copolymer is laminated on the surface thereof. A third aspect of the present invention is a method for producing a flame-resistant laminate cloth, wherein a surface temperature of a cooling roll for laminating the intermediate layer is set to 50 ° C. or higher.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The polypropylene used for the polypropylene multifilament of the present invention is preferably a polypropylene having high crystallinity and a high stretching effect. Specifically, propylene homopolymer, propylene-ethylene block Copolymer, propylene-ethylene random copolymer, and the like. Of these,
A polypropylene homopolymer having excellent moldability and high strength is preferable, and particularly, the isotactic pentad fraction is 0.1.
Highly crystalline polypropylene of 95 or more is preferred.
These polypropylenes may be used alone or in combination of two or more.

The method for producing the polypropylene multifilament is not particularly limited, and a known method for producing a multifilament is appropriately employed.
The total fineness of the multifilament is preferably 100 to 3000 denier (hereinafter referred to as d), and 300 to 1500 d
Is more preferred.

Next, a woven or knitted fabric is formed by weaving and knitting using the polypropylene multifilaments as warp yarns. The weaving and knitting structure is not particularly limited, and examples of the woven fabric include various woven fabrics such as plain weave, woven weave, leno weave, and the like. Include tricot, Miranese, and Russell versions.

JIS K6758 is provided on both sides of the woven or knitted fabric.
An intermediate layer containing a soft propylene polymer having a flexural modulus of 800 MPa or less, preferably 500 MPa or less, and a flame retardant, is laminated. Examples of the soft propylene-based polymer include a) a crystalline propylene-based polymer having an isotactic index of greater than 80;
0 parts by weight, b) 5 to 20 parts by weight of an ethylene-containing copolymer component insoluble in xylene at room temperature, and c) a copolymer component of ethylene and an α-olefin and optionally a small proportion of diene (the component is 40% by weight of ethylene). %, And soluble in xylene at room temperature).
50% to 90% by weight of the sum of the components (b) and (c)
% And the weight ratio of (b) / (c) is less than 0.4.

As the crystalline propylene-based polymer as the component (a), a propylene homopolymer or propylene and an α-olefin other than ethylene or propylene (particularly having 4 to 4 carbon atoms)
10 is preferable) and a propylene content of 85% by weight or more in monomer conversion. As the α-olefin constituting the copolymer of the component c), those having 4 to 10 carbon atoms as described above are preferable.

These propylene-based polymer compositions can be prepared by the multi-stage polymerization of ethylene, propylene and, if necessary, diene by the methods described in JP-A-6-25367 and JP-A-6-25439. It can be obtained by copolymerization.

Another form of the above soft propylene polymer is one obtained by random copolymerization of propylene and an α-olefin having 2 to 8 carbon atoms, particularly 20 to 35 mol% of propylene and ethylene 65 ~ 80 mol%
Or a copolymer of diene 0.1 to 0.1
An ethylene-propylene copolymer rubber which is an ethylene-propylene-diene copolymer containing 20 mol% is suitably used. Ethylene-propylene copolymer rubber is
It is a low crystalline or non-crystalline polymer having a density of 0.85-0.90 g / cm ³ .

The soft propylene-based polymer includes high-density polyethylene, linear low-density polyethylene, low-density polyethylene, ultra-low-density polyethylene, ethylene-vinyl acetate copolymer, ethylene-alkyl acrylate copolymer, and other polyethylene. A resin composition or a polyolefin resin such as polypropylene, a propylene-ethylene block copolymer, a propylene-ethylene random copolymer, or a polypropylene resin such as syndiotactic polypropylene may be blended and used as the resin composition. The amount is preferably 5 to 40% by weight, more preferably 10 to 30% by weight. If the amount of the polyolefin resin is more than 40% by weight, the flexibility is lowered, which is not preferable. If the amount is less than 10% by weight, processability is poor.

The above resin composition has an MFR of 1 to 30 g / 1.
0 min., Preferably in the range of 5 to 20 g / 10 min. If the MFR is less than 1 g / 10 min., The fluidity becomes poor, and if it exceeds 30 g / 10 min., The tensile strength and the like decrease, which is not desirable.

It is important that the resin composition has a flexural modulus measured by JIS K6758 of 800 MPa or less, particularly preferably 500 MPa or less.
When the flexural modulus is 800 MPa or more, the flexibility of the flameproof laminate cloth obtained is insufficient, and a sufficient improvement effect cannot be obtained.

As the flame retardant used in the present invention, a known flame retardant such as a halogen-based, phosphorus-based, or inorganic-based flame retardant is appropriately used. Flame retardants are preferred, and brominated flame retardants are particularly preferred.

Examples of the brominated flame retardant include aromatic brominated flame retardants such as tetrabromobisphenol A, decabromodiphenyl oxide, octabromodiphenyl oxide, bisdibromopropyl ether tetrabromobisphenol S, hexabromocyclododecane, and dibromoethyl. Examples thereof include alicyclic brominated flame retardants such as dibromocyclohexane, and liquid brominated flame retardants such as pentabromodiphenyl oxide and tetrabromodiphenyl oxide. These may be used alone or as a mixture of two or more.

The mixing ratio of the bromine-based flame retardant is 1 to 10% by weight, preferably 2 to 8% by weight, based on the soft propylene polymer or resin composition constituting the intermediate layer.
If the compounding ratio is less than 1% by weight, the flame retardancy becomes insufficient and
If it exceeds 0% by weight, the flame retardant effect is not further improved and it is not economical.

It is preferable to use antimony trioxide as a flame retardant aid in combination with the bromine flame retardant in view of improving the flame retarding effect. The mixing ratio of the brominated flame retardant to antimony trioxide is not particularly limited, but is 2: 1 to 3:
1 is preferred.

The propylene-ethylene random copolymer used for the surface layer of the laminate cloth of the present invention is a random copolymer of propylene and ethylene produced by a known method, and has an ethylene content of 1 to 10% by weight. , Preferably 4 to 7% by weight. It is also possible to mix other polyolefin resins other than the propylene-ethylene random copolymer without departing from the spirit of the present invention. The MFR of the propylene-ethylene random copolymer is preferably 1 to 30 g / 10 m
in., more preferably in the range of 5 to 20 g / 10 min.

In the present invention, a soft propylene polymer having a flexural modulus of 800 MPa or less as measured by JIS K6758 and a flame retardant are coated on both sides of a woven or knitted fabric using the polypropylene multifilament as a weft. The flameproof laminate cloth is formed by laminating the contained intermediate layer and the surface layer made of the propylene-ethylene random copolymer.

As a method of laminating the intermediate layer and the surface layer on both sides of the woven or knitted fabric, a known extrusion laminating method is used.
A multilayer extrusion lamination method in which the intermediate layer and the surface layer are simultaneously laminated may be used, but it is preferable to use a two-stage lamination method in which the intermediate layer is laminated and cooled, and then the surface layer is laminated.

In the above extrusion lamination method, the extrusion temperature of the soft propylene polymer used for the intermediate layer or the resin composition comprising the soft propylene polymer and another polyolefin resin is preferably less than 250 ° C., and preferably less than 230 ° C. More preferred. If the extrusion temperature exceeds 250 ° C., the roll release from the cooling roll deteriorates, which is not preferable.

In the extrusion laminating method, the surface temperature of the cooling roll for laminating the intermediate layer is preferably set to 50 ° C. or higher. When the surface temperature is lower than 50 ° C., the cooling rate increases, and there is no time for the molten resin to enter the gap between the base fabrics and generate an anchoring effect, and a sufficient peel strength between the base fabric and the laminate layer is obtained. Not so desirable. As a method of setting the surface of the cooling roll to 50 ° C. or higher, the temperature may be adjusted by the temperature of water passing through the cooling roll, or may be adjusted by providing a coating layer of silicon rubber or the like on the cooling roll.

The thickness of the intermediate layer provided by the extrusion lamination method is preferably 60 to 100 μm on one side. If the thickness of the intermediate layer is less than 60 μm, sufficient peel strength between the base fabric and the laminate layer cannot be obtained, and if it exceeds 100 μm, flexibility is lost, which is not preferable. The thickness of the surface layer provided by the extrusion lamination method is preferably 10 to 30 μm on one side. If the thickness of the surface layer is less than 10 μm, the wear resistance and lubricity cannot be obtained on the surface layer, and the effect of closing the pinholes generated in the intermediate layer cannot be sufficiently achieved.
Even if it exceeds μm, wear resistance and lubricity are not further improved, and it is not economical.

The basis weight of the flameproof laminate cloth of the present invention is preferably 100 to 500 g / m ² , and 150 to 3 g / m ^2.
50 g / m ² is more preferred.

The polyolefin resin used in the present invention includes an antioxidant, an ultraviolet absorber, a light stabilizer, a dispersant, a lubricant, an antistatic agent, a pigment, and an inorganic filler without departing from the spirit of the present invention. Ordinarily used additives such as a crosslinking agent, a foaming agent and a nucleating agent may be blended.

[0031]

EXAMPLES Example 1: Polypropylene (MFR = 20 g)
/ 10 min, density = 0.90 g / cm ³ , Tm = 15
Bis (2,2,6,6-) as a light stabilizer
A multifilament having a total fineness of 680 d / 120 f was formed using a composition containing 1% by weight of tetramethyl-4-piperidyl) sebacate. The polypropylene multifilament thus obtained was used as warp yarn to obtain a plain weave base fabric 2 having a driving density of 20 × 24 filaments / inch. The basis weight of the base fabric 2 was about 140 g / m ² . Further, a soft propylene-based resin for the intermediate layer was prepared as follows. That is, it was produced by a two-stage polymerization method of propylene and ethylene. The first stage product of the resulting polymer composition had an ethylene content of 3.0% by weight, a xylene solubles (S _A ) of 9.4% by weight,
The second stage product is a binary copolymer (b + c) (70% by weight of the total), and a xylene-soluble matter (S _F ) 63.
4% by weight, component b) 9.45% by weight, component c) 60.55
% By weight. The above soft propylene polymer (MFR
= 10 g / 10 min., Density = 0.89 g / cm ³ ,
The flexural modulus measured by JISK6758 is 130M
Pa) 75% by weight, low density polyethylene (MFR = 6 g)
/ 10 min., Density = 0.918 g / cm ³ ) 13% by weight, 9% by weight of a master batch containing a flame retardant, etc., bis (2,2,6,6-tetramethyl-4-piperidyl) as a light stabilizer
A resin composition for an intermediate layer containing 1% by weight of sebacate and 2% by weight of a white pigment was obtained. A master batch containing a flame retardant etc. is 15 wt% of bisdibromopropyl ether tetrabromobisphenol S as a brominated flame retardant with respect to 60 wt% of a propylene-ethylene random copolymer.
It contains 15% by weight of decabromodiphenyl oxide and 10% by weight of antimony trioxide. In addition, a propylene-ethylene random copolymer (MFR = 18.0)
g / 10 min., ethylene content = 6.0% by weight, JI
Flexural modulus measured by SK6758 is 850MP
a) A resin composition for the surface layer was prepared by blending 98% by weight and 2% by weight of a white pigment. Next, the intermediate layer 3 having a thickness of 80 μm is laminated on both surfaces of the base fabric 2 previously formed by extrusion lamination using the resin composition for the intermediate layer, and after cooling,
The resin composition for the surface layer was laminated with the surface layer 4 to a thickness of 15 μm by an extrusion lamination method to form a flameproof laminate cloth 1 having a basis weight of 310 g / m ² . The surface temperature of the cooling roll for laminating the intermediate layer 3 was 60 ° C. The obtained flameproof laminate cloth 1 had a stiffness measured by JISL1096 (cantilever method) of 80 mm, had foldable flexibility, good handleability, and good heat sealability. The peel strength between the base fabric 2 and the mid layer 3 was 3000 g / 15 mm. Furthermore, the maximum tensile point load is 128 kgf / 3 cm in the vertical direction, 122 kgf / 3 cm in the horizontal direction, and the maximum elongation is 18.0 in the vertical direction.
% And 20.0% in the horizontal direction. This value is based on JISA8
It passes the 952 building construction curing sheet 2 standard. In the flame retardancy test, the number of times of flame contact was 5 times,
It has passed the 091 flameproof standard.

Example 2 The procedure of Example 1 was repeated except that the resin composition for the intermediate layer was prepared as follows. That is, a propylene-ethylene random copolymer (MFR =
20 parts by weight of 18.0 g / 10 min., Ethylene content = 6.0% by weight, Tm = 128.4 ° C.) and ethylene-propylene copolymer rubber (Mooney viscosity (ML _{1 + 4} , 1
00 ° C) = 90, propylene content = 27% by weight) 80
88 parts by weight of a mixture with a weight part (the flexural modulus measured by JIS K6758 is 340 MPa), 9% by weight of a master batch containing a flame retardant and the like used in Example 1, and bis (2,2,6,6-) as a light stabilizer. A resin composition containing 1% by weight of tetramethyl-4-piperidyl) sebacate and 2% by weight of a white pigment was obtained. Obtained flameproof laminate cloth 1
Has a stiffness measurement value of 88 mm, has foldable flexibility, has good handleability, and has good heat sealability. The peel strength between the base cloth 2 and the intermediate layer 3 is 26.
It was 00 g / 15 mm. Furthermore, the maximum tensile point load is 124 kgf / 3 cm in the vertical direction and 116 kgf in the horizontal direction.
/ 3 cm, maximum elongation is 18.6% in the vertical direction and 20.5 in the horizontal direction
4%. This value satisfies the JIS A8952 Curing Sheet for Building Work Class 2 Standard. In the flame retardancy test, the number of times of flame contact was 5 and passed the flame resistance standard of JISL1091.

Comparative Example 1: As a resin composition for the intermediate layer,
Propylene-ethylene random copolymer (MFR = 1
8.0 g / 10 min., Ethylene content = 6.0% by weight, flexural modulus measured according to JIS K6758 of 85
0 MPa) 88% by weight, 9% by weight of the master batch containing the flame retardant used in Example 1, and bis (2,2,2) as a light stabilizer.
Flameproof laminate cloth 1 in the same manner as in Example 1 except that a resin composition containing 1% by weight of 6,6-tetramethyl-4-piperidyl) sebacate and 2% by weight of white pigment was used.
I got The flame-resistant laminate cloth 1 obtained had a measured value of bending resistance of 140 mm and lacked flexibility.

Comparative Example 2 A flameproof laminate cloth 1 was obtained in the same manner as in Example 1 except that the surface temperature of the cooling roll on which the intermediate layer 3 was laminated was set to 20 ° C. The peel strength between the base fabric 2 and the intermediate layer 3 of the obtained flameproof laminate cloth 1 was 550 g / 15 mm, which was not preferable because peeling easily occurred.

Comparative Example 3 A flameproof laminated cloth 1 was obtained in the same manner as in Example 1 except that the intermediate layer 3 and the surface layer 4 were subjected to the multilayer extrusion lamination method. The obtained flameproof laminate cloth 1 was not preferable because many pinholes were generated.

[0036]

As described above, the present invention provides an intermediate layer containing a specific soft propylene polymer and a flame retardant on both sides of a woven or knitted fabric using a polypropylene multifilament as a weft. A flame-resistant laminate cloth obtained by laminating a surface layer made of a propylene-ethylene random copolymer, which is lightweight, high-strength, and has excellent heat-sealing properties, flexibility, and abrasion resistance. Has slip properties. In addition, when laminating a laminate layer by extrusion lamination, while slowly cooling the intermediate layer to enter the gap of the base fabric to produce an anchoring effect and improve the peel strength between the base fabric and the laminate layer By performing lamination twice, a flameproof laminate cloth without pinholes was obtained. The flameproof laminate cloth of the present invention has better cold resistance and antifouling property than the conventionally used vinyl chloride resin coated type.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a flameproof laminate cloth according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Flameproof laminate cloth 2 Base cloth 3 Intermediate layer 4 Surface layer

 ──────────────────────────────────────────────────の Continuing on the front page F term (reference) 4F100 AH05H AK07A AK07B AK07C AK64D AK64E AL03D AL03E BA05 BA06 BA10D BA10E BA13 CA08B CA08C CA13 DG04A DG07A JDJ12J DG13 J05J13K13 YY00B YY00C

Claims (3)

[Claims] An intermediate layer containing a soft propylene-based polymer having a flexural modulus of 800 MPa or less and a flame retardant measured by JIS K6758, on both surfaces of a woven or knitted fabric using a polypropylene multifilament as a weft, A flameproof laminate cloth obtained by laminating a surface layer made of a propylene-ethylene random copolymer. 2. A flexural modulus of 800 measured on both sides of a woven or knitted fabric using a polypropylene multifilament as a weft by extrusion lamination according to JIS K6758.
A method for producing a flame-resistant laminate cloth in which an intermediate layer containing a soft propylene polymer having a pressure of not more than MPa and a flame retardant is laminated and cooled, and then a surface layer composed of a propylene-ethylene random copolymer is laminated on the surface thereof. . 3. An intermediate layer containing a soft propylene polymer having a flexural modulus of 800 MPa or less as measured by JIS K6758 and a flame retardant is laminated on both sides of a woven or knitted fabric using a polypropylene multifilament as a weft. After cooling, a surface layer made of a propylene-ethylene random copolymer is laminated on the surface thereof by an extrusion laminating method.
A method for producing a flame-resistant laminate cloth, which is set at a temperature of at least ℃.