JPH03158236A - Laminate with flexibility - Google Patents

Abstract

PURPOSE:To enhance the flexibility of the laminate concerned by a structure wherein the laminate consists of thermoplastic rubbery elastic layer, which is made of hydrogenated block copolymer and adherent ethylene copolymer, and non-woven fabric, the fibers of which are arranged longitudinally in parallel or in zigzag direction. CONSTITUTION:The laminate concerned is mad of thermoplastic rubber layer consisting of 100 pts.wt. of hydrogenated block copolymer, which is obtained by hydrogenating polymeric block A mainly made of one kind or more of vinyl aromatic compound and polymeric block B mainly made of one kind or more of conjugated diene compound, and 10-150 pts.wt. of ethylene-based copolymer and non-woven fabric. The vinyl aromatic compound used can be selected from among styrene, alpha-methylstyrene, vinyltoluene and the like. The conjugated diene compound before hydrogenated is selected from among butadiene, isoprene, 1,3-pentadiene and the like. Further, the non-woven fabric is fibers such as polypropylene fiber, acrylic fiber, polyester fiber or the like arranged longitudinally in parallel or in zigzag direction. Thus, the laminate having flexibility, waterproofness, dust-proofness and the like is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a stretchable laminate comprising a thermoplastic rubber layer and a nonwoven fabric layer.

More specifically, it can be applied to clothing base materials, bandages, bandages, diaper covers, packaging materials, industrial materials, etc. It can be heat-sealed at low temperatures, and has excellent mechanical properties, low temperature resistance,
This invention relates to a laminate with excellent elasticity and the like.

(Prior art) Non-woven fabrics have traditionally been used as interlining for clothing, medical gauze, gowns, sheets, masks, top sheets for disposable diapers, diaper liners, cosmetic gauze, wet towels, filters, wire wrapping tape, Agricultural heat insulation, shading frost protection material,
Tunnel vegetable cultivation covering material, drain material, slope protection material, soft ground stabilizing material, roof ink material, primary backing material for tufted carpet, PVC flooring base fabric, leather base fabric, artificial leather, varnished material, floppy disk It is used in a wide range of applications, including liners for commercial use, various packaging materials, and printing substrates such as labels. However, the nonwoven fabrics used for these purposes are manufactured by creating a sheet-like fiber aggregate (web) and then joining the fibers in the web, so like knitted fabrics, there are many fixing points. can be,
It has very little elasticity, so its uses are limited. Therefore, stretchable nonwoven fabrics are also required, and various proposals have been made to date. For example, non-woven fabrics using elastic fibers made of polyurethane (Japanese Patent Publications No. 43-26592, JP-B No. 44-215085), non-woven fabrics using diene copolymer fibers with rubber elasticity (Japanese Patent Publication Nos. 48-185979),
), nonwoven fabric using polyester elastomer fiber (JP-A-57-82552), nonwoven fabric made by bonding a web made of crimped acrylic fibers with microporous polyurethane (
JP-A-53-139873), a non-woven fabric in which silicone fibers are self-attached at their intersections (JP-A-62-133)
No. 163), etc. have been proposed, but these use stretchable fibers such as polyurethane and diene combinations, crimped acrylic fibers, and silicone fibers instead of the non-stretchable fibers that constitute the nonwoven fabric. They are expensive and have different physical properties.

Nonwoven fabrics are made by joining together webs of thin fibers, so they have excellent breathability, but they have no waterproof, dustproof, gas barrier, or bacterial barrier properties, and their uses are limited.

[Problem to be Solved by the Invention J] The present invention aims to provide a new material with excellent performance by taking advantage of the low cost and excellent performance of nonwoven fabric and imparting excellent performance that nonwoven fabric alone does not have. Take it as a challenge. That is, the object is to provide a laminated film having stretchability, waterproofness, dustproofness, gas barrier properties, bacterial barrier properties, flexibility, heat sealability, and the like.

[Means for Solving the Problems J The present inventor attempted to produce a stretchable nonwoven fabric by laminating a web with irregular fiber directions with a rubber elastic film, but the rubber elastic film did not work. Although it is stretchable, when the web of nonwoven fabric is fixed, the fibers that make up the nonwoven fabric are fixed at multiple points.
There are fibers in both the vertical and horizontal directions, and they are fixed just like knitted fabrics, so they no longer exhibit elasticity.In order to solve this problem, we replaced the conventional nonwoven structure with a specific structure It was discovered that if a nonwoven fabric is entirely fixed with a rubber elastic membrane, stretchability can be achieved by using a rubber elastic membrane. When polybutadiene-based, silicone-based, styrene-butadiene-based, natural rubber-based materials, etc. are used, film forming properties are very poor, productivity is poor, and the rubber elastic film produced has poor weather resistance, color tone, odor, etc. In order to solve these problems, he tested various materials and came to the conclusion that the problem could be solved by using thermoplastic rubber made of a specific hydrogenated block copolymer and an ethylene copolymer. Completed the invention.

That is, the present invention provides: 1) (a) A block copolymer consisting of a polymer block A mainly composed of at least one kind of vinyl aromatic compound and a polymer block B mainly composed of at least one kind of conjugated diene compound. A stretchable laminate comprising a thermoplastic rubber layer comprising 100 parts by weight of a hydrogenated block copolymer and 10 to 150 parts by weight of an ethylene copolymer and (b) a layer comprising a nonwoven fabric.

2) The stretchable laminate described above, wherein the hydrogenated block copolymer is a styrene/ethylene/butylene/styrene block copolymer.

3) The stretchable laminate described above, wherein the fibers constituting the nonwoven fabric are arranged in parallel only in the longitudinal direction.

4) The stretchable laminate described above, wherein the fibers constituting the nonwoven fabric are arranged in a meandering manner only in the longitudinal direction.

5) The thermoplastic rubber layer (R) and the nonwoven fabric layer (T) are (R)/
(T) or (R)/ (T)/ (R) or (T)/
The above-mentioned stretchable laminate, characterized in that the laminate is laminated like (R)/(T).

6) The above-mentioned stretchable laminate, which is produced by a T-die chill roll cooling method.

In the present invention, the hydrogenated block copolymer used is
It is obtained by hydrogenating a block copolymer consisting of a polymer block A mainly composed of at least one vinyl aromatic compound and a polymer block B mainly composed of at least one conjugated diene compound. , for example, A-B, A
-B-A, B-A-B-A, (A-B+-rS i
It is a hydrogenated vinyl aromatic compound-conjugated diene compound block copolymer having a structure such as , (B-AB)TSi.

Desirably, the hydrogenated block copolymer has a vinyl aromatic compound content of about 60% by weight or less, preferably 45% by weight or less. If it exceeds 60% by weight, the hydrogenated block copolymer loses its elasticity, making it impossible to produce the stretchable laminate of the present invention.

In addition, in the hydrogenated block copolymer, if the vinyl aromatic compound content is 15% or less, the glass transition point (T
The number of small aggregates (domains) containing g) decreases, and there are no bonding points for the rubber phase, which is not desirable because rubber elasticity is not exhibited.

In the hydrogenated block copolymer, the conjugated diene compound is
It is 40 to 85% by weight, preferably 55 to 75% by weight. This is because rubber elasticity is not exhibited outside this range.

Furthermore, referring to the block structure, a polymer block A mainly composed of a vinyl aromatic compound is a vinyl aromatic compound polymer block or a vinyl aromatic compound polymer block containing 50% of the vinyl aromatic compound.
It has a structure of a copolymer block of a vinyl aromatic compound and a hydrogenated conjugated diene compound containing more than 70% by weight, preferably 70% by weight or more, and further,
The polymer block B mainly composed of a hydrogenated conjugated diene compound is a hydrogenated conjugated diene compound polymer block or a hydrogenated conjugated diene compound containing more than 50% by weight, preferably 70% by weight or more. It has a structure of a copolymer block of a hydrogenated conjugated diene compound and a vinyl aromatic compound.

In addition, polymer block A mainly composed of these vinyl aromatic compounds and polymer block B mainly composed of hydrogenated conjugated diene compounds are hydrogenated conjugated diene compounds in the molecular chains of the polymer blocks, respectively. or random distribution of vinyl aromatic compounds, Cheebird (monomer component increases or decreases along the molecular steel),
It may be partially block-shaped or composed of any combination thereof, with two or more polymer blocks each consisting mainly of the vinyl aromatic compound and two or more polymer blocks mainly consisting of the hydrogenated conjugated diene compound. In some cases, each polymer block may have the same structure (or may have different structures).

As the vinyl aromatic compound constituting the hydrogenated block copolymer, one or more types can be selected from, for example, styrene, α-methylstyrene, vinyltoluene, p-tert, -butylstyrene, etc. Among them, styrene is preferred.

In addition, examples of the conjugated diene compound before hydrogenation constituting the hydrogenated conjugated diene compound include butadiene,
One or more of isoprene, 1,3-pentadiene, 2,3-dimethyl, -1,3-butadiene, etc. are excluded, and among them, butadiene, isoprene, and combinations thereof are preferred.

The microstructure of a polymer block mainly composed of a conjugated diene compound before hydrogenation can be arbitrarily selected. For example, in a polybutadiene block, the 1,2-microstructure is 20 to 20%. 50%, preferably 25-45%.

Further, the number average molecular weight of the hydrogenated block copolymer used in the present invention having the above-described structure is 5. OOO~1. OO
O, OOO1 preferably 30. OOO~200, O
The range is OO. When it is less than 5.000, the film strength becomes weak, which is undesirable. If it is OO or more, film formation becomes impossible, which is not desirable.

The molecular structure of hydrogenated block copolymers is linear, branched,
It may be a radial layer or any combination thereof.

These block copolymers may be produced by any method as long as they have the structure described above.

For example, a vinyl aromatic compound-conjugated diene compound block copolymer is synthesized in an inert solvent using a lithium catalyst or the like by the method described in Japanese Patent Publication No. 40-23798, and then, for example, No. 8704, Special Publication Showa 4
No. 3-6636, Special Publication No. 45-20504, Special Publication No. 4
6-20814, the method described in Japanese Patent Publication No. 48-3555, particularly preferably the method described in JP-A-59-133203 and JP-A-60-79005,
It can be synthesized by hydrogenation in an inert solvent in the presence of a hydrogenation catalyst.

Commercially available products include Asahi Kasei's Toughtic and Shell Chemical.
Kraton G, etc. are available, and it is desirable to use these.

In the present invention, the ethylene copolymer refers to ethylene-
These include acrylic ester copolymers, ethylene-vinyl ester copolymers, metal ion-containing ethylene copolymers, and the like.

Ethylene-acrylic acid ester copolymer includes ethylene and methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, pentyl acrylate, hexyl acrylate, methyl methacrylate,
It is made by copolymerizing monomers selected from ethyl methacrylate, propyl methacrylate, butyl methacrylate, pentyl methacrylate, hexyl methacrylate, etc.

The ethylene-vinyl ester copolymer is produced by copolymerizing monomers selected from ethylene vinyl formate, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl benzoate, and the like.

Metal ion-containing ethylene copolymers are ethylene-methacrylic acid copolymers, ethylene-acrylic acid copolymers, ethylene-itaconic acid copolymers, etc., in which the hydrogen atoms of the carboxyl groups are replaced with zinc, sodium, potassium, calcium, or magnesium. , is an ethylene copolymer containing ionic bonds substituted with metal ions such as aluminum, and is commercially available under the part name Surlyn.

The ethylene copolymer used in the present invention is l Hl or 2
A mixture of more than one species may be used.

In addition, small amounts of high-pressure low-density polyethylene, linear low-density polyethylene, polypropylene, etc. may be mixed and used for neck-in, drawdown improvement, blocking improvement, and other purposes in extrusion lamination. .

The content of the comonomer contained in the ethylene copolymer of the present invention is in the range of 5 to 40% by weight, preferably 15 to 25% by weight.

If it is less than 5% by weight, the adhesion with the nonwoven fabric will be poor;
If it exceeds 0% by weight, extrusion lamination properties, blocking, heat resistance, etc. will deteriorate.

The melt index of the ethylene copolymer used in the present invention is 1 to 150 g/10 minutes, preferably 3 to 60 g/l.
6.0 minutes. If Ig/10 minutes is lower than that, extrusion lamination becomes difficult and adhesion becomes poor. If it is higher than 150 g/10 minutes, drawdown will occur and processing will become impossible.

The ethylene copolymer used in the present invention includes:
Ethylene-ethyl acrylate copolymers are particularly excellent in compatibility with hydrogenated block copolymers, processability in the T-die chill roll method, heat resistance, film-forming properties, adhesive properties, and the like.

In the present invention, a resin composition in which 10 to 150 parts by weight of an ethylene copolymer is added to 100 parts by weight of a hydrogenated block copolymer is used as the thermoplastic rubber 1. If the amount of the ethylene copolymer is less than 10 parts by weight, the film forming properties of the resin composition will deteriorate, which is undesirable. If it is more than 150 parts by weight, the film layer made from the resin composition will lack rubber elasticity. The purpose of the present invention cannot be achieved.

In the present invention, nonwoven fabrics include polypropylene fibers, acrylic fibers, polyester fibers, polyamide fibers, rayon fibers, acetate fibers, triacetate fibers, polyvinyl alcohol fibers, polyvinyl chloride fibers,
Polyurethane fibers or the like are arranged in parallel only in the vertical direction, or arranged in a meandering manner only in the vertical direction.

Only a nonwoven fabric with such fiber arrangement can exhibit elasticity when laminated with thermoplastic rubber.

In the present invention, a thermoplastic rubber layer (R) and a nonwoven fabric layer (T
) The structure of the laminated film is (R)/(T), (R)
/ (T) / (R) or (T) / (R) / (T), and can be selected as appropriate depending on the purpose of use.

Lamination methods include one-way extrusion lamination, in which a resin composition consisting of a hydrogenated block copolymer and an ethylene copolymer is melt-extruded onto a nonwoven fabric layer, and a method in which lamination is performed using an adhesive.・It is preferable to manufacture the film using the chill roll method, as it is particularly excellent in terms of film formation gloss, anti-blocking properties, and less uneven thickness.

The thickness of the thermoplastic rubber layer is 10 to 100 g, (11' or 20 to 50 LL).

If it is less than 10 μm, the mechanical strength will be insufficient, and the fluffiness and adhesiveness will be poor, which is not desirable.

If it exceeds 10oLL, the elasticity will be poor and undesirable.

The basis weight of the nonwoven fabric is 5~500g/m'', preferably 50~
It is 200g/m2.

If it is less than 5 g/m", the functions of the nonwoven fabric (tensile strength imparting, barrier properties, slip properties, feel, good quality) will not be expressed, and if it exceeds 500 g/m", flexibility and bending resilience will be impaired. , lightness, feel, etc. are lost, which is undesirable. The fineness of the fibers constituting the nonwoven fabric used is 0.1 to 100 deniers, preferably 1 to 30 deniers.

If it is less than 0.1 denier, the tensile strength is too low, and if it exceeds 100 denier, flexibility, lightness, feel, etc. are undesirable.

K plate 52 100 parts by weight of styrene-ethylene-butylene-styrene copolymer (Tuffic H-1052 manufactured by Fukkasei) and ethylene-ethyl acrylate copolymer with an EA content of 18% and MI = 6 (DPDJ- manufactured by Nippon Unicar) 6169) 50 parts by weight, antioxidant (I RGANOX manufactured by Ciba Geigy)
1010) 0, 1 part by weight and 0.3 parts by weight of lubricant (stearamide) at 160°C in a Banbury mixer.
The mixture was kneaded for 10 minutes using a granulator and turned into pellets using a granulator. on the other hand,
A nonwoven fabric in which the fibers were arranged in parallel only in the longitudinal direction, as shown in FIG. 1, was prepared using 5 denier nylon fibers with a basis weight of 60 g/m'.

Next, extrusion lamination was performed on the above nonwoven fabric using the above pellet under the following conditions.

651!111 diameter extruder, three-stige screeny lower die, 50C) nm width air gap LIOmm Processing speed 50m/min Laminate thickness 20um Resin temperature 280°C Next, cut the wound roll appropriately and evaluate the laminate. I did it.

The resin between and the fibers of the nonwoven fabric did not separate, but the fibers that made up the nonwoven fabric separated.

2 plates 1 The stress when elongated by 600% in the lateral direction is 240 kgf
/ cm” and recovered to its original shape when the tensile stress was released.

It cannot be stretched in the longitudinal direction and has no elasticity.

EXAMPLE 11 An experiment was carried out in exactly the same manner as in Example 1, except that instead of the nonwoven fabric shown in Section 1 of Example 1, a nonwoven fabric in which the fibers were meandered in the longitudinal direction as shown in FIG. 2 was used.

It was able to expand by 400% in the horizontal direction and 300% in the vertical direction.

When the tensile stress was released in both directions, it quickly returned to its original state.

Instead of the ethylene-ethyl acrylate copolymer of Example 1, an ethylene-vinyl acetate copolymer with a VA content of 18% and M I =-10 (NUC-319 manufactured by Nippon Unicar Co., Ltd.) was used.
An experiment similar to Example 1 was conducted except that 0) was used. The product had a slight acetic acid odor, but there was no problem in terms of performance.

Both adhesiveness and stretchability are almost the same as the results of Example 1, and are practical.

Support Wataru 1 Same as Example 1 except that ethylene-zinc methacrylate copolymer (manufactured by DuPont Mitsui Polychemicals, Himilan AM-6004) was used instead of the ethylene-ethyl acrylate copolymer of Example 1. We conducted an experiment.

Both adhesiveness and elasticity are almost the same as the results of Example 1, so it is practical.

1. Exactly the same experiment as in Example 1 was conducted except that the amount of ethylene-ethyl acrylate copolymer was changed to 10 parts by weight.

The drawdown properties were somewhat poor, but lamination was possible. The resulting laminate had a stress of 210 kgf/c+s'' when it was stretched by 600%, and when the tensile stress was released, it recovered to its original shape very quickly.

EXAMPLE 1 An experiment was carried out in exactly the same manner as in Example 1, except that the amount of ethylene-ethyl acrylate copolymer was changed to 150 parts by weight.

Although the extrusion coating properties were very good, the stress of the produced laminate when elongated by 300% was 320 kgf/
c+w'', and although it did not recover to its original shape immediately after the tensile stress was released, sufficient elasticity was observed.

Except that a non-hydrogenated styrene-butadiene-styrene copolymer (Califlex TRII○1 manufactured by Shell Chemical Co., Ltd.) was used instead of the styrene-ethylene-butylene-styrene copolymer in Example 1. , an experiment similar to Example 1 was conducted. Drawdown properties during lamination were poor and lamination was impossible.

This comparative example confirms that the hydrogenated copolymer is an essential component of the present invention.

In place of the ethylene-ethyl acrylate copolymer of Example 1, high-pressure low-density polyethylene (Nippon Unicar Co., Ltd. NU
C-8008, density 10.918, MI=5. The same experiment as in Example 1 was conducted except that the following was used. Although there were no problems with extrusion coating, the adhesion between the resin film and the nonwoven fabric was poor, and the laminate had poor elasticity, making it impractical.

This comparative example confirms that the ethylene copolymer is an essential component of the present invention.

An experiment similar to Example 1 was conducted except that the commonly used nonwoven fabric shown in FIG. 3 was used in place of the nonwoven fabric shown in FIG. 1 in Example 1. The resulting laminate is non-stretchable in both directions;
Not practical.

[Effects of the Invention] The present invention provides a laminate consisting of a thermoplastic rubber elastic layer made of a hydrogenated block copolymer and an adhesive ethylene copolymer, and a nonwoven fabric layer arranged in parallel or meandering in the longitudinal direction. Therefore, during manufacturing, an extrusion lamination method that can be produced quickly can be used, and the produced three-dimensional structure has excellent elasticity, waterproofness, abrasion resistance, gas barrier properties, heat sealability, flexibility, and mechanical properties. It is a new material that has strong physical strength and has never been seen before.

Suitable for use as clothing base materials, bandages, supporters, diaper covers, packaging materials, industrial materials, etc.

4. Mere Statement FIG. 1 is a schematic representation of a nonwoven fabric in which the fibers are arranged parallel to the longitudinal direction, which is used in the production of the laminate of the present invention.

FIG. 2 is a schematic diagram of a nonwoven fabric in which fibers meander in the longitudinal direction.

FIG. 3 is a schematic diagram of a commonly used nonwoven fabric with intertwined fibers.

Figure 1 Second Figure 3

Claims (1)

[Claims] 1) (a) A block copolymer consisting of a polymer block A mainly composed of at least one vinyl aromatic compound and a polymer block B mainly composed of at least one conjugated diene compound. A stretchable laminate comprising a thermoplastic rubber layer comprising 100 parts by weight of a hydrogenated block copolymer and 10 to 150 parts by weight of an ethylene copolymer and (b) a layer comprising a nonwoven fabric. 2) The stretchable laminate according to claim 1, wherein the hydrogenated block copolymer is a styrene/ethylene/butylene/styrene block copolymer. 3) The stretchable laminate according to claim 1, wherein the fibers constituting the nonwoven fabric are arranged in parallel only in the longitudinal direction. 4) The stretchable laminate according to claim 1, wherein the fibers constituting the nonwoven fabric are arranged in a meandering manner only in the longitudinal direction. 5) The thermoplastic rubber layer (R) and the nonwoven fabric layer (T) are (R)/
(T) or (R)/(T)/(R) or (T)/(R)
2. The stretchable laminate according to claim 1, wherein the laminate is laminated as shown in FIG. 6) The stretchable laminate according to claim 1, which is produced by a T-die chill roll cooling method.