JPH06344484A - Moisture permeable reinforced laminate - Google Patents

Abstract

PURPOSE:To provide the laminate holding water resistance, moisture permeability and air permeability, enhanced in mechanical strength and improved in secondary processability such as thermal fusion by laminating a foamed sheet composed of a thermoplastic resin and a thermoplastic resin sheet through a nonwoven fabric composed of a uniaxially oriented thermoplastic resin material. CONSTITUTION:A porous film composed of a thermoplastic resin such as high, medium and low density polyethylens or ethylene/propylene copolymer rubber and a random nonwoven fabric composed of high density polyethylene, polypropylene, polyester or polyamide are integrally laminated through a nonwoven fabric or fabric composed of a unidirectionally oriented thermoplastic resin material. The nonwoven fabric or fabric composed of the unidirectionally oriented thermoplastic resin material is pref. a multilayered film oriented by laminating a second layer of a thermoplastic resin having an m.p. lower than that of a first crystalline thermoplastic resin to at least the single surface of the layer of the first thermoplastic resin.

Description

Detailed Description of the Invention

[0001]

The present invention has water resistance and breathability,
The present invention relates to a moisture-permeable reinforced laminate excellent in mechanical strength and heat sealability.

[0002]

2. Description of the Related Art Conventionally, water-proof and breathable sheets have been used for disposable body warmers, desiccants, deodorants, oxygen scavengers, packaging bags, disposable diapers, clothing, agricultural and horticultural covering materials,
It is used in various fields such as building materials such as house wraps. These sheets are generally a laminated film of a porous film of a thermoplastic resin having air permeability and a perforated film, a uniaxially stretched tape or a uniaxially stretched film made of a thermoplastic film and a thermoplastic resin, which is split and woven. Well-known is a composite film laminated with a split woven reticulated non-woven fabric, a spun-bonded non-woven fabric using a thermoplastic resin, a melt blown non-woven fabric, a needle punched non-woven fabric, or a composite laminated non-woven fabric formed by laminating non-woven fabrics such as a wet process non-woven fabric. (For example, JP-A-56-163350 and JP-A-61-1).
71331, 63-286331, 64-90
No. 746).

However, these conventional laminated films and composite films both have a problem in secondary workability such that the seal portion is melted during heat-sealing and cannot be heat-sealed, and the composite laminated nonwoven fabric and the like. Has a drawback that it is inferior in mechanical strength, heat sealability and the like.

[0004]

DISCLOSURE OF THE INVENTION The present invention has been made as a result of extensive studies to solve the above-mentioned problems, and maintains water resistance, moisture permeability, air permeability, mechanical strength, and the like. It is an object of the present invention to provide a moisture-permeable reinforced laminate having excellent heat resistance and secondary processability such as heat sealability.

[0005]

Means for Solving the Problems The inventors of the present invention have made extensive studies in accordance with the above-mentioned object, and as a result, a porous film made of a thermoplastic resin and a random non-woven fabric were used as a nonwoven fabric or a woven fabric made of a uniaxially stretched tape of a thermoplastic resin. The present inventors have found that excellent performance can be achieved by laminating a cloth or a non-woven fabric or a woven fabric composed of a split-fiber uniaxially stretched body obtained by splitting a uniaxially stretched film, and arrived at the present invention.

That is, the first aspect of the present invention is characterized in that a porous film made of a thermoplastic resin and a random nonwoven fabric are laminated and integrated through a nonwoven fabric or a woven fabric made of a uniaxially stretched thermoplastic resin. It is a moisture-permeable strengthened laminated body.

According to a second aspect of the present invention, a non-woven fabric or a woven fabric composed of a uniaxially stretched thermoplastic resin has a melting point lower than that of the first thermoplastic resin on at least one surface of the crystalline first thermoplastic resin layer. It is formed from the multilayer film which laminated | stacked the layer of the 2nd thermoplastic resin which has this. The moisture-permeable reinforcement laminated body of Claim 1 characterized by the above-mentioned.

The present invention will be described in detail below.

The porous film made of a thermoplastic resin used in the present invention is a film obtained by stretching an inorganic fine particle blended with a thermoplastic resin incompatible polymer or a thermoplastic resin (Japanese Patent Laid-Open No. Sho 50). -16561, etc.), a film obtained by cooling a resin such as polyolefin under high shear to form a specific crystal structure, and stretching (Japanese Patent Publication No. 46-40119, etc.); And the film obtained by extraction (Japanese Patent Publication No. 58-321171 and Japanese Patent Publication No. 61-37436).
Gazette etc.) and the like.

The thickness of the porous film is 5 to 500 μm.
m, preferably 10 to 100 μm, the average pore size is 0.01 to 50 μm, preferably 0.05 to 5 μm, and the porosity is 30 to 90%.

The moisture permeability of the porous film having the above-mentioned thickness is usually 500 g / m ² · 24 hr or more, preferably 1000 g / m ² · 24 hr or more, air permeability (Gurley type)
5000 sec / 100 cc or less, preferably 3000
sec / 100cc or less, more preferably 2000se
It is c / 100 cc or less.

Specific product names of the porous film include Espoir, Duraguard, FP-2, NF sheet, Cellboa NW01, polyflon paper and the like.

As the thermoplastic resin forming the above-mentioned porous film, high, medium density polyethylene, low density polyethylene, linear low density polyethylene, ultra low density polyethylene, ethylene-propylene copolymer rubber, ethylene-propylene- Polyene resin such as diene copolymer rubber, ethylene-vinyl acetate copolymer, ethylene- (meth) acrylic acid copolymer, ethylene- (meth) acrylic acid ester copolymer, polyolefin resin such as polypropylene resin , Polyamide resin, polyester resin,
Examples thereof include polyvinyl chloride-based resin, polycarbonate-based resin, polyurethane and the like, and there is no particular limitation. However, from the viewpoint of being inexpensive and imparting functionality such as flexibility, suppleness, and texture, linear low-density polyethylene,
Ultra low density polyethylene, ethylene-propylene copolymer rubber, ethylene-propylene-diene copolymer rubber, ethylene-vinyl acetate copolymer, ethylene- (meth) acrylic acid copolymer, ethylene- (meth) acrylic acid ester A porous film obtained by stretching a composition obtained by blending a relatively soft polyethylene resin such as a copolymer with an inorganic filler is preferable.

The random nonwoven fabric used in the present invention includes synthetic fibers such as high-density polyethylene, polypropylene, polyester, polyamide, polyacryl, etc., multifilaments such as natural fibers such as cotton, wool and hemp, and staple fibers. Including those that have been accumulated. More preferably, it is a fibrous random nonwoven fabric using a high melting point first fiber and a low melting point second fiber.

Specifically, a random nonwoven fabric obtained by accumulating a mixture of a high melting point first fiber web and a low melting point second fiber web or an adhesive resin, a high melting point first fiber forming a core component. With a low melting point that forms the sheath component with the fibers of
Random non-woven fabric obtained by accumulating composite fibers composed of the above-mentioned fibers, random non-woven fabric obtained by accumulating side-by-side composite fibers composed of a high melting point first fiber and a low melting point second fiber, and a melt blown filament. 10 to 200 g / m ² , preferably 12 to 150 g / m ² , obtained by making a paper from a random nonwoven fabric obtained by accumulating, a high melting point synthetic pulp and / or fiber web and a low melting point synthetic pulp and / or fiber web. Random non-woven fabrics having a basis weight of ² are included.

Among the above random non-woven fabrics, non-woven fabrics obtained by mixing core type or parallel type composite fibers and rayon fibers are preferable. This rayon fiber includes rayon staples, filaments, etc., and rayon fiber and cotton,
It may be mixed with other fibers such as silk, wool, acetate, vinylon, nylon and polyester.

The amount of the above-mentioned fibers having adhesiveness is preferably in the range of 5 to 100 parts by weight with respect to 100 parts by weight of rayon fibers.

Examples of the high melting point first fibers include synthetic fibers such as high density polyethylene, polypropylene, polyester, polyamide and polyacryl, and natural fibers such as cotton, wool and hemp.

The low melting second fiber is generally one using a thermoplastic resin selected from thermoplastic resins having a lower melting point than the thermoplastic resin forming the high melting first fiber. Used for.

Specific examples of the core or side-by-side composite fibers described above include high density polyethylene (hereinafter sometimes abbreviated as HDPE) / low density polyethylene (hereinafter,
In some cases, abbreviated as LDPE, omitted below), HDPE
/ Ethylene-vinyl acetate copolymer (EVA), polypropylene (PP) / propylene-ethylene copolymer (PE
C), PP / HDPE, polyester (PE _S ) / copolyester (CPE _S ), PE _S / HDPE, PE
_S / PP, Polyamide (PA) / PP, PA / HDPE
There are various combinations such as "NB"
"F", "ES fiber", "UC fiber", "Elves", "Sunmore" and the like.

The non-woven fabric or woven fabric made of the uniaxially stretched thermoplastic resin of the present invention means a uniaxially stretched product obtained by stretching or rolling a crystalline thermoplastic resin, for example, a stretching tape, a flat yarn or a split fiber membrane. Etc. are woven or not woven so that the orientation axes cross each other, and are laminated in a weft direction. In particular, a multilayer stretched body formed by applying a layer of a second thermoplastic resin having a melting point lower than that of the first thermoplastic resin to at least one surface of the layer of the crystalline first thermoplastic resin is preferable. More specifically, a stretched tape formed by applying a layer of a second thermoplastic resin having a melting point lower than that of the first thermoplastic resin to at least one surface of the layer of the crystalline first thermoplastic resin, Process Laminated non-woven fabric or woven woven fabric,
Molten resin is formed into a film by extrusion molding, and after stretching, split fiber membrane with split network or split fiber membrane nonwoven fabric with warp and weft laminate of split fiber membrane, multi-layer stretched membrane penetrated by hot needle, punching, etc. Etc. Among these, stretched tape or non-woven fabric or woven fabric made of stretched tape,
A split fiber membrane having a network structure obtained by splitting a multilayer stretched film or a split fiber membrane nonwoven fabric obtained by laminating warp and weft fibers is preferable.

The above-mentioned stretched tape or a non-woven fabric or a woven woven fabric obtained by laminating warp-and-wefts of the stretched tape uses a first thermoplastic resin and a second thermoplastic resin having a melting point lower than that of the first thermoplastic resin. , Multi-layer inflation method,
At least 2 produced by extrusion molding such as multilayer T-die method
Before and / or after cutting a multi-layered film having more than one layer, it is uniaxially or biaxially oriented at a stretching ratio of 1.1 to 15 times, preferably 3 to 10 times in a longitudinal and / or transverse direction, and cut to produce a multilayer tape. The multi-layered tape is then woven or non-woven by weaving or weaving the multi-layered tape at right angles to the orientation axis or in an oblique direction, or by laminating and heat fixing.

The width of the stretched tape is generally 3 to 50 m.
m, preferably 5 to 30 mm.

The above orientation magnification (elongation magnification) is 1.1 to
It is 15 times, but it is desirable to orient in multiple stages in order to prevent uneven drawing. For example, in the first stage, the primary orientation is 1.1 to 8 times, preferably 5 to 7 times, and in the second stage and thereafter, the elongation ratio is 5 to 15 with respect to the initial dimension.
It is preferable to perform the secondary or tertiary orientation so that the orientation is doubled, preferably 6 to 10 times. When the stretching ratio of the above-mentioned multilayer stretched film is less than 1.1 times, the mechanical strength of the woven fabric or the nonwoven fabric is not sufficient. On the other hand, when the extension ratio exceeds 15 times, it is difficult to extend by a normal method, and a problem such as an expensive device is required.

As these multilayer stretched tapes, those having a three-layer structure in which the second thermoplastic resin layer is provided on both surfaces of the first thermoplastic resin layer may be used.

As the method of heat fixing, the method of continuously heat fixing the woven fabric or the laminated sheet while winding it on a heating cylinder drum is most preferable.

The split fiber membrane comprises a first thermoplastic resin,
A second thermoplastic resin having a melting point lower than that of the first thermoplastic resin is used, and a multilayer film having at least two layers is produced by extrusion molding such as a multilayer inflation method or a multilayer T-die method. Or put a slit on the side,
A split fiber membrane obtained by uniaxially or biaxially orienting at a stretching ratio of 1.1 to 15 times, preferably 3 to 10 times in the longitudinal or transverse direction,
If desired, it is expanded and heat set to manufacture. Further, the split fiber nonwoven fabric is a product obtained by laminating the split fiber membranes on a weft and a weft and fixing them by heat. Specific products of the split fiber non-woven fabric include "Nisseki Warif".

The orientation method may be either a rolling method or a stretching method, but in the stretching method, the pseudo-uniaxial stretching method is particularly preferable.

The rolling method referred to here is that a thermoplastic resin film is passed between two heating rolls having a smaller gap in its thickness, and this resin film is rolled at a temperature lower than its melting point (softening point). Then, a method of extending the length by an amount corresponding to the reduction of the thickness.

The quasi-uniaxial stretching method is a method in which a thermoplastic resin film is stretched by passing it between a low-speed roll and a high-speed roll (proximity roll) having a roll gap as small as possible, and suppressing shrinkage in the width direction as small as possible. Is.

The thickness ratio of the layer of the first thermoplastic resin to the layer of the second thermoplastic resin of the multilayer film is not particularly limited, but the second thermoplastic resin having a low melting point is used as the adhesive layer. In this case, the thickness is preferably 50% or less, and more preferably 40% or less of the total thickness of the multilayer film.

The thickness of the second thermoplastic resin layer is 5 μm.
If it is above, various physical properties such as adhesive strength at the time of heat fusion are satisfied, but it is preferably selected from the range of 10 to 100 μm.

As the crystalline first thermoplastic resin used in the present invention, high / medium density polyethylene, polypropylene, polybutene-1, poly-4-methylpentene-1,
Homopolymers of α-olefins such as polyhexene-1, polyolefins such as copolymers of α-olefins such as propylene-ethylene copolymer, polyamides, polyesters, polycarbonates, crystalline resins such as polyvinyl alcohol, and the like. .

The low melting second thermoplastic resin used in the present invention includes high-medium-low density polyethylene, linear low density polyethylene, ultra low density polyethylene, ethylene-vinyl acetate copolymer, ethylene-acrylic. Acid copolymers, ethylene-methacrylic acid copolymers, ethylene-ethyl acrylate copolymers and other ethylene-acrylic acid ester copolymers and ethylene-methacrylic acid ester copolymers, ethylene-maleic acid or its ester copolymers Examples thereof include a coalesced product; a propylene-based polymer such as polypropylene and a propylene-ethylene copolymer; a polyolefin formed by using an unsaturated carboxylic acid; a copolyester. For manufacturing reasons, the difference in melting point from the first thermoplastic resin is preferably at least 5 ° C or more, more preferably 10 to 50 ° C.

Specific resin constitutions of the multilayer stretched film include HDPE / LDPE, LDPE / HDPE / L.
DPE, LDPE / EVA, EVA / HDPE / EV
A, PP / PEC, PEC / PP / PEC, PE _S / C
Examples include PE _S and CPE _S / PE _S / CPE _S.

The present invention will be described below with reference to examples.

Example 1 [Manufacture of reticulated split fiber nonwoven fabric composed of multilayer stretched film] High density polyethylene (MFR 1.0 g / min, density 0.956 g / cm ³ , as first thermoplastic resin by a multilayer water cooling inflation method, Melting point 129 ° C .; trade name: Nisseki Staflen E710, Nippon Petrochemical Co., Ltd., is used as an inner layer, and low density polyethylene (MFR 3.0 g / min, density 0.924 is used as a second thermoplastic resin on both surfaces thereof.
g / cm ³ , melting point 109 ° C .; trade name: Nisseki Lexron F
30, made by Nippon Petrochemical Co., Ltd., with a thickness of 15μ
m (LDPE) / 100μm (HDPE) / 15μm
A multilayer film of (LDPE) is produced, and the multilayer film is stretched 8 times and then split into a weighed amount of 18 g / m.
² , a reticulated split fiber membrane having a three-layer structure with a width of 1 m was obtained. Next, this mesh-like split fiber membrane was laminated in a weft direction so that the orientation axes were orthogonal to each other to produce a split fiber nonwoven fabric (abbreviated as "Nisseki Wallif").

[Manufacture of Breathable Reinforcement Laminate] The above-mentioned Nisseki Warif is a porous film (trade name: Espoir, manufactured by Mitsubishi Kasei Co., Ltd.), 80% by weight of rayon fiber and ES fiber (polyester resin in core, sheath Polyethylene composite fiber) 20% by weight intervening between rayon non-woven fabrics, each of which is supplied at a line speed of 40 m / min, a heating temperature of about 120 ° C. and a pressure of 2.0 to 4.0 k.
Thermal fusion was performed at g / cm ² to obtain a moisture-permeable reinforced laminate.

Then, the reinforcing sheet was heat-sealed using a seal bar, and the heat sheet property was good.

Comparative Example 1 A laminate of the porous film used in Example 1 (trade name: Espoir, manufactured by Mitsubishi Kasei Co., Ltd.) and Nisseki Warif was prepared. When the laminate was subjected to a heat fusion process using a seal bar, the fusion zone was fused.

[0041]

INDUSTRIAL APPLICABILITY As described above, the moisture-permeable reinforced laminate of the present invention retains water resistance, moisture permeability and air permeability, is excellent in mechanical strength, and has secondary workability such as heat sealability. Since it has and is easily adhered by heat fusion, it is possible to inexpensively manufacture products such as clothing, and it is suitable for agricultural and horticultural use, civil engineering and construction, logistics materials, packaging materials, and the like.

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Claims (2)

[Claims] 1. A moisture-permeable reinforced laminate comprising a porous film made of a thermoplastic resin and a random nonwoven fabric which are laminated and integrated via a nonwoven fabric or a woven fabric made of a uniaxially stretched thermoplastic resin. 2. A non-woven fabric or a woven fabric comprising a uniaxially stretched body of a thermoplastic resin, wherein a second heat having a melting point lower than that of the first thermoplastic resin is formed on at least one surface of a layer of the crystalline first thermoplastic resin. The moisture-permeable reinforced laminate according to claim 1, which is formed of a multilayer film in which layers of a plastic resin are laminated.