JP2000127311A - Cloth sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cloth sheet, which is light in weight, has a high strength, is excellent in flexibility, and has a high frequency weldability. SOLUTION: This cloth sheet is produced by forming coating layers on both sides of a cloth woven or knitted of stretched polypropylene yarns. The coating layer consists of a layer made of a component A and a layer made of a component B. The component A is a pluralistic copolymer consisting of an ethylene and a radical polymerizable acid anhydride and a radical polymerizable comonomer except them under the condition that the percentage of an aicd anhydride group containing unit is 0.1-5 wt.% and the percentage of an ethylene unit and the unit except the acid anhydride group containing unit is 3-50 wt.%. The component B has a crystalline propylene-based polymer portion (a), an ethylene-containing copolymer portion (b), which is insoluble in a xylene under room temperature, and an ethylene-containing copolymer portion (c), which is soluble in the xylene under room temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cloth sheet, and more particularly, to a cloth sheet such as a cover for building material, a sheet such as a waterproof sheet, a tent, a packaging bag, a flexible container and the like.

[0002]

2. Description of the Related Art Hitherto, a large number of laminated sheets having a resin layer provided on one or both sides of a fiber cloth have been known as cloth sheets used for covers, sheets and the like. Sheets for these applications include high strength that can withstand the tensile force during sheet expansion and the gravitational force of the contents of the package, and the flexibility to handle objects well as covers and sheets, It is required that the contents to be covered or packaged be identified from the outside. As a sheet for such an application, a cross sheet in which a polyvinyl chloride film is laminated on a cloth made of nylon, polyester fiber, or the like is frequently used. These cross sheets are made of multi-filaments such as nylon and polyester fibers to maintain high strength and flexibility, and form a cross sheet by laminating polyvinyl chloride with excellent high frequency welding properties. In recent years, there has been a demand for the development of a cross sheet which can be used instead of bleeding of a plasticizer, generation of a toxic gas at the time of incineration, and poor workability due to its large specific gravity.

As an alternative to the above polyvinyl chloride, a cross sheet using an ethylene-vinyl acetate copolymer (EVA) or an ethylene-alkyl (meth) acrylate copolymer having high frequency welding properties has been proposed. ing.
However, ethylene-vinyl acetate copolymers have poor heat resistance, and ethylene-alkyl (meth) acrylate copolymers have the problem that the high-frequency welding property is remarkably inferior to polyvinyl chloride, and these copolymers have a problem. The union has a disadvantage that adhesiveness is inferior to different kinds of thermoplastic resins such as nylon, polyester, and polypropylene, and there is a problem that a thermoplastic resin cloth to be laminated is limited.

[0004]

SUMMARY OF THE INVENTION In view of the above circumstances, an object of the present invention is to provide a cross sheet that is lightweight, high in strength, excellent in flexibility, and excellent in high frequency welding.

[0005]

SUMMARY OF THE INVENTION The present invention is a cloth sheet having a coating layer formed on both sides of a woven or knitted fabric using a drawn yarn made of polypropylene, wherein the coating layer comprises the following component (A). There is provided a cross sheet comprising an ethylene multi-component copolymer layer and a propylene polymer composition as a component (B): (A) ethylene, a radical polymerizable acid anhydride and other radical polymerizable A multi-component copolymer comprising a comonomer, wherein the ratio of the acid anhydride group-containing unit is 0.1 to 5% by weight in terms of the weight of the monomer used, and the ratio of the units excluding the ethylene unit and the acid anhydride group-containing unit is (B) (a) a crystalline propylene-based polymer portion, (b) an ethylene-containing copolymer portion insoluble in xylene at room temperature, and (c) xylene at room temperature. Soluble d A propylene-based copolymer having a tylene-containing copolymer portion.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.

A woven or knitted fabric (hereinafter referred to as a woven or knitted fabric) using a drawn yarn made of polypropylene is used as a base fabric constituting the cross sheet of the present invention. The polypropylene used here is preferably a polypropylene having high crystallinity and a high stretching effect, and specific examples thereof include a propylene homopolymer, a propylene-ethylene block copolymer, and a propylene-ethylene random copolymer. Can be 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.

[0008] The fiber shape of the drawn yarn is not particularly limited, such as multifilament, monofilament, flat yarn and split yarn as long as high strength is obtained, deterioration during woven knitting is good, and woven knitting is good. And those manufactured by known manufacturing methods can be used. Of these, multifilaments having excellent adhesion to the coating layer and having flexibility are particularly preferably used.

[0009] The fineness of the drawn yarn is determined in consideration of the mechanical strength required for the woven or knitted fabric, and is not particularly limited. Is preferably 100-5000 total fineness
Denier (hereinafter referred to as d), more preferably 30
0 to 3000d. If the fineness is less than 100d, the mechanical strength of the yarn constituting the cross sheet is not sufficient,
On the other hand, when the fineness exceeds 5000d, not only the weaving efficiency is inferior, but also the flexibility as a woven knitted fabric is inferior, and further, the lamination with the coating layer is not formed tightly, and the peel strength and the welding strength, etc. The physical properties required for the cross sheet cannot be satisfied.

Next, a woven or knitted fabric is formed by weaving and knitting using the above-mentioned polypropylene multifilament. The weaving and knitting structure is not particularly limited, and examples of the weaving and knitting fabric include various weaving and knitting fabrics such as plain weave, woven weave, leno weave, and the like. Specific examples include tricot knitting, Miranese knitting, and Russell knitting.

The coating layer of the present invention comprises a component (A), a layer comprising an ethylene multi-component copolymer comprising ethylene, a radical polymerizable acid anhydride and other radical polymerizable comonomers, and a component (B). (A) a crystalline propylene-based polymer having an isotactic index greater than 80, (b) an ethylene-containing copolymer fraction insoluble in xylene at room temperature, and (c) ethylene and an α-olefin, Of a propylene-based polymer composition containing a proportion of a diene and copolymer fraction (the fraction contains less than 40% by weight of ethylene and is soluble in xylene at room temperature). .

The radically polymerizable acid anhydride in the component (A) has at least one radically polymerizable unsaturated bond and one or more acid anhydride groups in the molecule, and the acid anhydride group is formed in the molecule by polymerization. Means a compound that can be introduced into The acid anhydride group is preferably cyclic. Such compounds include:
For example, maleic anhydride, itaconic anhydride, citraconic anhydride and the like can be mentioned.

The ratio of the unit derived from the radically polymerizable acid anhydride, ie, the unit containing the acid anhydride group, in the ethylene multi-component copolymer is 0.1 to 5% by weight based on the weight of the monomer used.
, Preferably in the range of 0.5 to 4.5% by weight, more preferably in the range of 1.0 to 4.0% by weight. Here, the ratio of the acid anhydride group-containing unit is 0.1% by weight.
If the amount is less than the above, the adhesiveness to the thermoplastic resin cloth is insufficient, and the high frequency welding property is poor. If the amount exceeds 5% by weight, the economic efficiency and the formability are reduced, and commercial production becomes difficult. It has no practical meaning.

As the radical polymerizable comonomer other than ethylene and the radical polymerizable acid anhydride, there are various compounds such as a vinyl ester compound, a (meth) acrylate compound, an unsaturated oxide, and an unsaturated hydrocarbon other than ethylene. And the like.

Examples of the vinyl ester compound include vinyl acetate, vinyl propionate, vinyl benzoate and the like.

Examples of the (meth) acrylate compound include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, methyl fumarate, ethyl fumarate, and maleic acid. Methyl and ethyl maleate.

As the unsaturated acid compound, for example, (meth)
Examples include acrylic acid, fumaric acid, and maleic acid.

Examples of the unsaturated hydrocarbon compound include styrene, α-methylstyrene, norbornene, butadiene and the like.

Among these, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate and the like are particularly preferred compounds. These monomers may be used alone or in combination of two or more.

The proportion of units derived from the above radical polymerizable comonomer in the ethylene multi-component copolymer is in the range of 3 to 50% by weight, preferably in the range of 5 to 40% by weight. Especially for applications where high frequency welding is required,
Preferably it is in the range of 10 to 35% by weight. Here, when the ratio of the radical polymerizable comonomer is less than 3% by weight,
The crystalline melting point of the ethylene multi-component copolymer is not low enough,
The low-temperature adhesiveness cannot be sufficiently exhibited. Also, 5
If the content exceeds 0% by weight, the handling of the resin becomes difficult, and the heat resistance of the product decreases.

The component (A) has an MFR of 1 to 30 g / 1.
0 min. , Preferably 5 to 20 g / 10 min. It is better to select from the range. MFR is 1 g / 10 min.
If less than 30 g / 10 min. If it exceeds, the tensile strength and the like are lowered, which is not desirable.

In producing the ethylene multi-component copolymer, basically, ordinary low-density polyethylene production equipment and techniques can be used. Generally, a bulk polymerization method is used, and a pressure of 700 to 3000 atm.
It is produced by radical polymerization in a temperature range of 00 ° C. The preferred polymerization pressure is 1000 to 2500 atm, and the average temperature in the reactor is 150 to 270 ° C. If the pressure is 700 atm or less, the molecular weight of the polymer tends to be low, and the moldability and the resin properties of the composition tend to deteriorate. Pressures above 3000 atmospheres are virtually meaningless and only increase manufacturing costs. When the average polymerization temperature is 100 ° C. or lower, the polymerization reaction is not stable, and the conversion into a multi-component copolymer is reduced, which is economically problematic.
When the temperature exceeds 300 ° C., the molecular weight of the multi-component copolymer decreases, and at the same time, the risk of runaway reaction occurs.

It is desirable to use a vessel type reactor as an apparatus used for producing the ethylene multi-component copolymer. In particular, radical polymerizable acid anhydrides have poor polymerization stability, and therefore require a high degree of uniformity in the reactor. If necessary, a plurality of reactors can be connected in series or in parallel to carry out multistage polymerization. Further, by dividing the inside of the reactor into a plurality of zones, more precise temperature control can be performed. The production of the ethylene multi-component copolymer used in the present invention is carried out under the above reaction conditions in the presence of at least one free radical initiator. Examples of the free radical initiator include generally known diacyl peroxides, peroxycarbonates, peroxyesters, ketone peroxides, and other azo compounds. In the polymerization, various chain transfer agents can be used as a molecular weight regulator.

The above-mentioned ethylene multi-component copolymer can be blended with other polyolefin resins depending on the purpose of use. Specific examples of these polyolefin resins include high-density polyethylene, linear low-density polyethylene,
Polyethylene resins such as low-density polyethylene, ultra-low-density polyethylene, ethylene-vinyl acetate copolymer, ethylene-alkyl (meth) acrylate copolymer, polypropylene, propylene-ethylene copolymer, and soft propylene polymer Examples include polypropylene-based resins. The content of these polyolefin resins is 5% by weight.
It is preferably less than.

The component (B) of the present invention comprises (a) a crystalline propylene polymer portion having an isotactic index of greater than 80, (b) an ethylene-containing copolymer portion insoluble in xylene at room temperature, and (c) A) a propylene polymer having an ethylene-containing copolymer moiety soluble in xylene at room temperature, and particularly preferably (a) a crystalline propylene 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 fraction insoluble in xylene at room temperature, and (c) a copolymer fraction of ethylene and α-olefin and optionally a small proportion of diene (the The fraction contains less than 40% by weight of ethylene,
40-80 parts by weight (soluble in xylene at room temperature), and the weight percentage of the sum of the fraction (b) and the fraction (c) is 50%-
A propylene-based polymer (composition) having 90% and a weight ratio of (b) / (c) of less than 0.4 is used.

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

These propylene-based polymers (including compositions) are disclosed in JP-A-6-25367 and JP-A-6-25367.
It can be obtained by copolymerizing ethylene, propylene and, if necessary, diene by multistage polymerization according to a method described in, for example, Japanese Patent No. 25439. Therefore (B)
The components typically include so-called block copolymers.

The propylene polymer of the component (B) includes polypropylene, such as polypropylene, propylene-ethylene block copolymer, propylene-ethylene random copolymer, and syndiotactic polypropylene, without departing from the spirit of the present invention. A system resin can be blended. The blending amount of the polyolefin resin is preferably less than 5% by weight.

The MFR of the component (B) is 1 to 30 g / 1.
0 min. , Preferably 5 to 20 g / 10 min. It is better to select from the range. MFR is 1 g / 10 min.
If less than 30 g / 10 min. If it exceeds, the tensile strength and the like are lowered, which is not desirable.

In the present invention, a coating layer comprising the ethylene copolymer layer as the component (A) and the propylene-based polymer composition layer as the component (B) is formed on both sides of the woven or knitted fabric. Into a cross sheet. By forming this coating layer, a cross sheet having increased high-frequency weldability with increased mechanical strength of the sheet can be obtained. The coating layer may be coated on each side one step at a time, or may be coated alternately in multiple steps.

When the woven / knitted fabric layer is a layer (C), (C)
Specific configurations of the layers (A) and (B) with respect to the layers are as follows:
(A) / (B) / (C) / (B) / (A), (B) /
(A) / (C) / (B) / (A), (B) / (A) /
(C) / (A) / (B), (B) / (A) / (C) /
(A) / (B) and other layers (A) on one side of the (C) layer, (B)
Two layers may be arranged in order, and (A)
/ (B) / (C) / (A), (B) / (A) / (C) /
(A), (A) / (B) / (C) / (B), (B) /
(A) / (C) / (B), etc., may be one layer on the other side with respect to two layers on one side, or one layer on each side, such as (A) / (C) / (B). Among them, a combination in which the layer (C) and the layer (B) are in contact is more preferable in that the adhesiveness to the layer (C) is more excellent.

The ratio of the component layer (A) and the component layer (B) is such that (A) / (B) is 30/70 to 70 on a weight basis.
/ 30 is preferable, and 40/60 to 60/40 is more preferable. When the proportion of the component layer (A) is less than 30% by weight, the high-frequency welding property is inferior, which is not preferable.
If it is less than 0% by weight, the flexibility becomes insufficient, which is not preferable.

In forming the coating layer, known techniques such as an extrusion laminating method, a calendering method, a coating method, and a dipping method are employed. When this coating layer is formed, the front and back layers are joined by the molten resin penetrating into the gaps of the woven or knitted fabric, or by the resin penetrating between the front and back of the gap generated at the intersection of the warp yarns. If the bridging effect is developed, the peel strength can be improved, which is effective. Also,
The thickness of the coating layer is not particularly limited,
Each of the component layers (A) and (B) preferably has a thickness of 25 to 50 μm, more preferably 30 to 45 μm. Generally, in consideration of the substrate strength and the heat welding property, the total thickness of each of the component layers (A) and (B) is preferably 50 to 100 μm per one side, and 6
0 to 90 μm is more preferable. Further, in the multilayer molding, a single-layer multi-stage extrusion laminate or a co-extrusion laminate may be used.

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. , A commonly used additive such as a crosslinking agent, a foaming agent, and a nucleating agent.

[0035]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below based on embodiments. (Example 1): polypropylene (MFR = 20 g / 10)
min. , Density = 0.90 g / cm ³ , Tm = 158.
(0 ° C.) to form a multifilament having a total fineness of 680 d / 120 f. The polypropylene multifilament thus obtained was used as a warp yarn, and the driving density was 20%.
A plain woven fabric of × 20 / inch was obtained. The basis weight of the woven fabric was about 120 g / m ² . Further, a resin for a coating layer was prepared as follows. That is, an ethylene-butyl acrylate-maleic anhydride terpolymer was used as the ethylene copolymer of the component (A). The copolymer was produced using a high-pressure low-density polyethylene plant facility, and the content of units derived from butyl acrylate was 7% by weight, and the content of units derived from maleic anhydride was 2.5% by weight. . MFR of this ethylene copolymer = 10 g / 10
min. And the density was 0.935 g / cm ³ . In addition, as a propylene-based polymer as the component (B), 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-soluble component (S _A ) of 9.4% by weight, and the second-stage product has a binary copolymer ( b + c) (a total 70% by weight of), xylene solubles (S _P) 63.4 wt%,
Fraction b) was 9.45% by weight and fraction c) was 60.55% by weight. MFR of this component (B) = 10 g / 10 mi
n. , Density = 0.89 g / cm ³ . Next, on both surfaces of the previously formed woven fabric (C), a layer (A) having a thickness of 40 μm was formed by extrusion lamination using the above coating resin.
(B) 30 μm layer, (A) / (B) / (C) / (B)
/ (A) to form a cross sheet. The obtained cross sheet was heat-welded using a high-frequency welder at an anode current value of 1.0 A. The T-peel strength is 1012 gf / 15 mm and the weld strength is 71 kg.
It had good weldability at f / 5 cm. Furthermore, JI
The bending resistance measured by SL1096 (cantilever method) was 56 mm, and it had foldable flexibility and good handleability. The maximum tensile load is 109 kg.
f / 3 cm, the maximum elongation was 29.4%.

(Example 2): The coating layer was made of (B) / (A) /
Example 1 except that the layers were laminated as in (C) / (A) / (B).
The same was done. The T-peel strength after heat-welding the obtained cloth sheet using a high-frequency welder is 1126 gf.
/ 15 mm, and the tensile strength at the welded portion was 78 kgf / 5 cm, indicating good weldability. In addition, the measured bristles are 60
mm, it was foldable and easy to handle. The maximum tensile load is 105 kgf /
3 cm and the maximum elongation was 28.7%.

(Comparative Example 1): Example 1 as a coating resin
Using the ethylene copolymer of the component (A)
The procedure was performed in the same manner as in Example 1 except that a coating layer of 0 μm was laminated as (A) / (C) / (A). The T-peel strength after heat-welding the obtained cross sheet using a high-frequency welder is 1080 gf / 15 mm, and the tensile strength at the welded portion is 100.
It had good weldability at kgf / 5 cm. further,
The measured bending resistance was 72 mm, and the flexibility and handleability were somewhat poor. The maximum tensile load is 108 kg.
f / 3 cm, the maximum elongation was 22.8%.

(Comparative Example 2): Example 1 as a coating resin
The procedure was performed in the same manner as in Example 1 except that the coating layer having a thickness of 70 μm was laminated as (B) / (C) / (B) using the propylene polymer of the component (B) used in (1). The obtained cross sheet had a measured bending resistance of 54 mm, had foldable flexibility, and was easy to handle, but was poor in high frequency welding with a high frequency welder. The maximum tensile point load was 110 kgf / 3 cm, and the maximum elongation was 30.2%.

(Comparative Example 3): Example 1 as a coating resin
Using the ethylene copolymer (A) component and the propylene-ethylene random copolymer (ethylene content = 6% by weight) used in the above, the thickness of the (A) layer is 40 μm, and the (E) layer is 30 μm. (A) / (E) / (C) / (E) / (A)
The procedure was performed in the same manner as in Example 1 except that the layers were stacked as described above. The T-peel strength after heat-welding the obtained cross sheet using a high-frequency welder was 915 gf / 15 mm, and the tensile strength at the welded portion was 57 kgf / 5 cm, and the weldability was good. However, the measured value of the bending resistance was 95 mm, and the flexibility was poor. The maximum tensile load is 110 kgf / 3 cm,
The maximum elongation was 28.2%.

[0040]

As described above, according to the present invention, a woven or knitted fabric made of a thermoplastic resin is provided with a coating layer made of a resin containing a specific ethylene copolymer on both surfaces thereof. It is possible to provide a cross sheet having strong layer adhesive strength, excellent mechanical properties, excellent flexibility, and high-frequency welding property, and covers such as building material covers,
It is suitably used for sheets such as waterproof sheets, tents, packaging bags, flexible containers and the like.

[Brief description of the drawings]

FIG. 1 is a cross sheet showing a first embodiment of the present invention, in which (a) is a schematic cross-sectional view and (b) is a plan view of a cloth used.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cloth sheet 2 Polypropylene multifilament 3 Cloth 4 Inner coating layer 5 Outer coating layer

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tatsuaki Kinan 763 Tsurushinda, Renjima-cho, Kurashiki-shi, Okayama Prefecture (72) Inventor Naoki Mihogawa 2-3-2 Night Light, Kawasaki-ku, Kawasaki-shi, Kanagawa Japan Polyolefin Co., Ltd. Kawasaki In the laboratory (72) Inventor Mahiro Ueno 2-3-2, Yakko, Kawasaki-ku, Kawasaki-city, Kanagawa Japan F-term in the Kawasaki Research Laboratory, Polyolefin Co., Ltd. F-reference (reference) BA06 BA10B BA15 DG12A DG13A EJ37A GB15 GB90 JK06 JK13 JK17 JL12 YY00B 4L033 AA05 AB04 AB05 AB06 AC02 AC11 AC15 CA12 CA18 CA69 CA70

Claims (1)

[Claims] 1. A cross sheet having a coating layer formed on both sides of a woven or knitted fabric using a drawn yarn made of polypropylene,
A cross-sheet wherein the coating layer comprises an ethylene multi-component copolymer layer as a component (A) and a propylene-based polymer composition as a component (B): (A) ethylene and a radical polymerizable acid A multi-component copolymer comprising an anhydride and a radical polymerizable comonomer other than these, wherein the ratio of an acid anhydride group-containing unit is 0.1 to 5% by weight in terms of the weight of a monomer used, and ethylene units and an acid anhydride are used. (B) (a) a crystalline propylene-based polymer portion and (b) an ethylene-containing copolymer insoluble in xylene at room temperature, wherein the proportion of units excluding the group-containing units is 3 to 50% by weight. A propylene-based copolymer having a portion and (c) an ethylene-containing copolymer portion soluble in xylene at room temperature.