JP2000220769A - Laminating cloth for air duct and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminating cloth for an air duct without a pinhole, superior in heat sealability, flexibility, and flame resistance, having moderate slipping property, and wherein a woven fabric and a laminated layer have a high peel strength and a tensile elongation after fracture is maintained at 20% or less. SOLUTION: The laminating cloth for an air duct is a laminated body composed by laminating an intermediate layer 3 including a flexible propylene based polymer having a flexural elastic modulus measured under JISK 6758 of 800 MPa or less and a flame retarder, and a surface layer 4 made of a propylene/ethylene random copolymer, on both surfaces of a woven fabric using a polypropylene multifilament for warp and weft, and has a tensile elongation after fracture of the laminated body of 20% or less.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminate for air tubes and a method for producing the same.

[0002]

2. Description of the Related Art Fresh air or cold / hot air is blown using a wind pipe for ventilation, cooling and heating during tunnel construction, work inside a mine tunnel, or cleaning work inside a manhole or tank. That is being done. In such a wind tube, when the base material is stretched at the time of blowing, air traps are generated at the portion, causing wind interference and reducing the amount of blown air. Therefore, the tensile elongation at break of the base material is 20% or less. Preferably, it is required to be 18% or less.

Conventionally, as such a sheet for a wind tube, a sheet obtained by laminating a polyvinyl chloride film on a woven fabric using multifilament yarn such as polyester or nylon is generally used. The advantage is that the woven fabric has sufficient strength, is flexible, and is provided with flame retardancy by a polyvinyl chloride layer. Poisonous gas is generated, the plasticizer bleeds, and there is a problem such as dirt and smell. Also, the weight is large and the handling property is not good. 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 obtained by laminating a polypropylene layer on a woven fabric made of polypropylene multifilament, which has excellent filament formability and does not generate toxic gas, has been used as a sheet for a wind tube. However, a sheet obtained by laminating a polypropylene layer on a base cloth made of polypropylene multifilaments as the weft of a woven fabric usually has a large tensile elongation at break of 20% or more,
It was not suitable as a sheet for wind tubes. In addition, the above-mentioned sheet is inferior in flexibility due to the high flexural modulus of the polypropylene used in the polypropylene layer, and has the inconvenience that it is not easy to handle as a sheet for a wind pipe in the work of stretching at a construction site, and the flexibility is improved. If a soft propylene polymer having a low flexural modulus is used for the laminate layer for this purpose, the abrasion resistance and lubricity of the sheet surface are reduced, and there is also a problem that blocking occurs undesirably.

[0005] Further, a sheet obtained by laminating a soft propylene-based polymer layer containing a flame retardant to impart flame retardancy to the surface of a woven fabric has two problems, such as edge processing and joining of sheets. In addition to problems such as poor heat sealability due to bleed of the flame retardant during the next processing,
There was a problem that high peel strength could not be obtained due to poor adhesion between the woven fabric composed of polypropylene multifilaments and the soft propylene polymer layer. Therefore, at the time of laminating the woven fabric and the soft propylene-based polymer layer, the soft propylene-based polymer layer is gradually cooled so that the soft propylene-based polymer layer digs into the base fabric to improve the adhesiveness and obtain high peel strength. In this case, there is also a problem that the cooling of the soft propylene-based polymer layer in the opening portion of the base fabric is delayed and pinholes are generated.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has a high peel strength between a woven fabric and a laminate layer, a tensile breaking elongation of 20% or less, and It is an object of the present invention to provide a pinhole-free laminar cloth for a wind tube having excellent heat sealability, flexibility, abrasion resistance, and flame retardancy and having an appropriate slip property, and a method for producing the same.

[0007]

Means for Solving the Problems In order to solve the above problems technically, the present invention provides a JIS K675 on both sides of a woven fabric using a multifilament made of polypropylene as a weft.
A laminate comprising a soft propylene-based polymer having a flexural modulus of 800 MPa or less and a flame retardant, and an intermediate layer containing a propylene-ethylene random copolymer. A first aspect of the present invention is a wind tube laminate cloth characterized in that the laminate has a tensile elongation at break of 20% or less.

Further, the present invention provides a woven fabric using multifilaments made of polypropylene for warp yarns on both sides of a JISK fabric.
Extrusion lamination in which an intermediate layer containing a soft propylene polymer having a flexural modulus of 800 MPa or less as measured according to 6758 and a flame retardant is laminated and cooled, and a surface layer composed of a propylene-ethylene random copolymer is laminated on the surface thereof. A second aspect of the present invention is a method for producing a laminar cloth for air tubes, wherein the 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 Hereinafter, the present invention will be described in detail.
The polypropylene used for the polypropylene multifilament of the present invention is preferably a polypropylene having high crystallinity and a high stretching effect, and specifically, propylene homopolymer, propylene-ethylene block copolymer, propylene-ethylene And random copolymers. Among these, a polypropylene homopolymer having excellent moldability and high strength is preferred, and a highly crystalline polypropylene having an isotactic pentad fraction of 0.95 or more is particularly 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, the woven fabric is formed by weaving the multifilament made of polypropylene as the warp yarn. The woven structure is not particularly limited, and examples of the woven fabric include various woven fabrics such as plain weave, woven weave, and leno weave.

On both surfaces of the woven 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, measured according to JIS K6758, is laminated. Examples of the soft propylene polymer include a) a crystalline propylene polymer having an isotactic index of greater than 80;
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 is 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,
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-based resin exceeds 40% by weight, the flexibility is lowered, and if it is less than 5% by weight, the processability is not sufficient, which is not preferable.

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.

The above resin composition preferably has a flexural modulus measured by JIS K6758 of 800 MPa or less, more preferably 500 MPa or less. When the flexural modulus is 800 MPa or more, the flexibility of the obtained laminate cloth 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, on the both sides of a woven fabric using the polypropylene multifilament as a weft,
The flexural modulus measured according to JIS K6758 is 80.
An intermediate layer containing a soft propylene polymer having a pressure of 0 MPa or less and a flame retardant, and a surface layer made of the propylene-ethylene random copolymer are laminated to form a laminate for air tubes. It is important that the tensile elongation at break of the wind tube laminate cloth is 20% or less, more preferably 18% or less.

As a method of laminating the intermediate layer and the surface layer on both sides of the woven fabric, a two-stage laminating method is used in which the intermediate layer is laminated, cooled, and then the surface layer is laminated.

In the above extrusion laminating 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 270 ° C., and preferably less than 250 ° C. More preferred. If the extrusion temperature exceeds 270 ° 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 Examples Polypropylene (MFR = 20 g / 10 min, density =
(0.90 g / cm ³ , Tm = 158.0 ° C.), a composition containing 1% by weight of bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate as a light stabilizer was used. A multifilament having a total fineness of 680d / 120f was formed. The polypropylene multifilament thus obtained was used as warp yarn to obtain a plain weave base fabric 2 having a driving density of 15 × 22 filaments / inch. The basis weight of the base cloth 2 is about 140 g /
It was 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 has an ethylene content of 3.0% by weight and a xylene solubles (S _A ) of 9.4% by weight, and the second stage product has a binary copolymer ( b + c) (70% by weight of the total), 63.4% by weight of xylene-soluble component (S _F ), component b)
9.45% by weight, component c) 60.55% by weight. The above soft propylene polymer (MFR = 10 g / 10 mi)
n., density = 0.89 g / cm ³ , the flexural modulus measured by JIS K6758 is 130 MPa) 75% by weight,
13% by weight of low density polyethylene (MFR = 6 g / 10 min., Density = 0.918 g / cm ³ ), 9% by weight of a master batch containing a flame retardant, etc., and bis (2,2,
There was obtained a resin composition for an intermediate layer containing 1% by weight of 6,6-tetramethyl-4-piperidyl) sebacate and 2% by weight of a white pigment. The masterbatch containing a flame retardant etc. is composed of 60% by weight of a propylene-ethylene random copolymer, 15% by weight of bisdibromopropyl ether tetrabromobisphenol S, 15% by weight of decabromodiphenyl oxide, and 10% by weight of antimony trioxide as brominated flame retardants. % By weight. In addition, a propylene-ethylene random copolymer (MFR = 18.0 g / 10 min.,
98% by weight of ethylene content = 6.0% by weight) and 2% by weight of a white pigment were blended to prepare a resin composition for a surface layer. Then, an extrusion temperature of 25 was applied to both surfaces of the base fabric 2 previously formed by extrusion lamination using the resin composition for the intermediate layer.
After laminating the intermediate layer 3 having a thickness of 70 μm at 0 ° C. and cooling, the resin composition for the surface layer was subjected to extrusion lamination to a thickness of 20 μm.
m, the surface layer 4 was laminated 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 55 ° C. The obtained flameproof laminate cloth 1 has a stiffness measured by JISL1096 (cantilever method) of 80 mm, has foldable flexibility, has good handleability, has good heat sealability, and has a pinhole. There was no. The peel strength between the base fabric 2 and the mid layer 3 was 3500 g / 15 mm.
Furthermore, the tensile breaking strength is 130 kgf / 5 cm in the longitudinal direction,
165kgf / 5cm in transverse direction, tensile elongation at break is 1 in longitudinal direction
6.0% and 17.0% in the horizontal direction. This value is based on JIS
It meets A8952 Building Curing Sheet Class 2 Standard. In the flame retardancy test, the number of times of flame contact was 5 times, according to JIS
It has passed the flameproof standard of L1091.

Comparative Example The extrusion temperature of the intermediate layer was 280 ° C. and the cooling roll temperature was 10
The procedure was performed in the same manner as in Example 1 except that the temperature was ° C. The obtained flameproof laminate cloth 1 has a stiffness measured by JISL1096 (cantilever method) of 84 mm, has foldable flexibility, has good handleability, has good heat sealability, and has a pinhole. There was no. However, the peel strength between the base fabric 2 and the intermediate layer 3 was significantly reduced to 860 g / 15 mm. Further, the tensile strength at break is 135 in the longitudinal direction.
kgf / 5 cm and 170 kgf / 5 cm in the transverse direction, but the tensile elongation at break was 24.0% in the longitudinal direction and 23.0% in the transverse direction.
It was not suitable as a laminating cloth for wind tubes.

[0033]

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 fabric using a polypropylene multifilament as a weft, A laminate formed by laminating a surface layer made of an ethylene random copolymer, wherein the laminate has a tensile elongation at break of 20% or less and is a laminate cloth for a wind tube, which is lightweight, strong, and heat-sealing. This is a laminar cloth for wind tubes having excellent flexibility, abrasion resistance and moderate 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

Continued on the front page F-term (reference) 3H111 AA02 BA17 BA25 BA34 CB06 CB29 CC02 DA10 DA11 DA15 DB11 DB15 4F100 AA29 AH05 AK06 AK07A AK07B AK07D AK64C AK64E AL03C AL03E AL05 BA05 BA06 BA10E CA05 CA11 CA04E18 CA18 CA11B04 CA11 JK06 JK07B JK07D JK08 JK13B JK13D JK17

Claims (2)

[Claims] 1. 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, on both sides of a woven fabric using a polypropylene multifilament as a weft. A laminate comprising a surface layer made of an ethylene random copolymer and having a tensile elongation at break of 20;
% Or less. 2. 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 fabric using a polypropylene multifilament as a weft. After cooling, an extrusion lamination method in which a surface layer made of a propylene-ethylene random copolymer is laminated on the surface,
A method for producing a laminated cloth for wind pipes, wherein the surface temperature of a cooling roll for laminating the intermediate layer is set to 50 ° C. or higher.