JPH0490337A - Laminate and production thereof - Google Patents

Abstract

PURPOSE:To prevent the penetration of water and the stuffiness in a glove when the glove is formed by laminating a water impermeable layer composed of a polyester elastomer and a microporous film layer composed of polyolefin. CONSTITUTION:A laminate is constituted by laminating a water impermeable layer having thickness of 2-40mum composed of a polyester elastomer whose moisture permeability is 1500g/m<2>.24h.25mum or more and a microporous film layer composed of polyolefin having the max. pore size of 10mum or less and a void ratio of 20-80% and formed by laminating the sheet of the aforementioned polyester elastomer and the sheet of polyolefin containing 30-80wt.% of a filler and stretching the laminated one. The glove prepared using this laminate generates no penetration of water or an org. solvent in the glove when water containing a surfactant or an org. solvent is handled and no stuffiness is generated in the glove.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a laminate that is moisture permeable, water impermeable, and has excellent mechanical strength, and a method for producing the same.

(Prior Art and Problems to be Solved by the Invention) As a moisture-permeable and water-impermeable sheet, a sheet prepared by blending an inorganic filler with a polyolefin and stretching the mixture is known.

This sheet has micropores caused by interfacial peeling between the polyolefin and the inorganic filler. Water vapor passes through these micropores, but water cannot pass through the micropores due to the water repellency of polyolefin. Therefore, the sheet exhibits moisture permeability and water impermeability. Therefore, when the above sheet is used to make gloves used for washing work,
This prevents water from entering and also prevents stuffiness inside the glove.

However, surfactants such as detergents are often used for laundry work, and in this case, water passes through micropores due to the action of the surfactant, causing a problem in that water infiltrates into the glove.

(Means for Solving the Problems) The present inventors have conducted repeated research to overcome the problem of water infiltration into the interior of gloves made from conventional microporous membranes made of polyolefin. The inventors have discovered that the above object can be achieved without impairing moisture permeability by laminating a layer of nonporous polyester elastomer on a microporous membrane made of polyolefin, and have proposed the present invention.

That is, the present invention has a moisture permeability of 1500g/rr1'+
A non-water permeable layer with a thickness of 2 to 40 μm made of polyester elastomer of 24 hr / 25 μm or more, and a layer of microporous membrane made of polyolefin with a maximum pore diameter of 10 μm or less and a porosity of 20 to 80% are laminated. It is a laminate made of

One layer of the laminate of the present invention has a moisture permeability of 1500 g/T.
T? - Made of polyester elastomer of 24 hr/25 μm or more. The above moisture permeability is a value measured for a polyester elastomer having a thickness of 25 μm at 40″C2 relative humidity of 90% according to JISZ 0208.

When gloves, etc. are made using the laminate of the present invention, the moisture permeability of the polyester elastomer is 1 to prevent stuffiness.
It is necessary that it is 500 g/in, 24 hr, and 25 μm or more. If a polyester elastomer with a moisture permeability lower than the above value is used, the thickness of the polyester elastomer layer must be reduced in order to obtain the required moisture permeability when formed into a laminate, which may cause breakage, etc. This is not preferable because it causes a decrease in practical strength.

The polyester elastomer in the present invention has a moisture permeability of 1500 g/rr? + 24 hr ・25 μm
Any known material can be used without any restriction as long as it is above. For example, known polyester elastomers described in JP-A-63-116850, JP-A-51-111290, and pages 476 to 495 of "Saturated Polyester Resin Handbook" can be employed. In the present invention, it is particularly preferable to use a polyester elastomer having a hard segment produced by an ester reaction between a dicarboxylic acid and a low molecular weight diol and a soft segment produced by an ester reaction between a dicarboxylic acid and a polyalkylene glycol. Furthermore, the proportion of the above soft segment is 50 to 90.
% by weight can be particularly preferably used. The dicarboxylic acid that is the raw material for the above polyester elastomer is
Aromatic cyclophonic acids such as terephthalic acid, phthalic acid, isophthalic acid, bisbenzoic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid; sebacic acid,
Aliphatic dicarboxylic acids such as adipic acid, geltaric acid, and 1,3-cyclohexanedicarphonic acid can be mentioned. Examples of low-content diols include ethylene glycol, propylene glycol, 1,4-butanediol,
Examples include pentamethylene glycol. In addition, as polyalkylene glycol, polyethylene glycol, polypropylene glycol, etc. are used,
The molecular weight is preferably in the range of 400 to 4,000.

Note that polyester elastomer is preferable because it has a melt flow index at 200''C in the range of 1 to 20 or because it can be easily molded.

The thickness of the layer made of the above polyester elastomer is
2-40μm to obtain good moisture permeability and mechanical strength
and preferably 3 to 30 μm. Furthermore, the layer made of the above-mentioned polyester elastomer is non-porous and exhibits water impermeability.

Next, the other layer of the laminate of the present invention is a microporous membrane layer made of polyolefin having a maximum pore diameter of 10 μm or less and a porosity of 20 to 80%. As the polyolefin, homopolymers or copolymers of α-olefins such as ethylene, propylene, -butene, 1-pentene, and mixtures thereof can be used without any restriction. Specifically, high-density polyethylene, low-density polyethylene, linear low-density polyethylene, polypropylene, ethylene-propylene copolymer, polybutene, etc. can be mentioned, and furthermore, ethylene and acrylic ester, methacrylic ester,
A copolymer with vinyl acetate or the like may also be employed, and in the present invention, linear low-density polyethylene is particularly preferably used because it forms a flexible and tough microporous membrane.

The microporous membrane made of the polyolefin described above has many fine pores with a maximum pore diameter of 10 μm or less, and has a porosity of 20 to 80%. The maximum pore diameter above is 10μm
A porous film exceeding 100% can be obtained by using a filler with a large particle size and increasing the stretching ratio in the manufacturing method described below. However, if this is done, there is a risk that the polyester elastomer layer will break due to the filler or stretching. It is undesirable because of In addition, if the porosity is smaller than the above range, moisture permeability will be insufficient, and if it is larger than the above range, film formation will be difficult and sufficient mechanical strength will not be obtained. unfavorable to

The microporous membrane made of the above-mentioned polyolefin is generally made of 3
000 to 8000 g/n (・24.hr).

In order to obtain sufficient mechanical strength and flexibility, the thickness of the layer of the microporous membrane made of the above-mentioned polyolefin is generally 5 to 5.
It is preferable to select from the range of 200 tlI11 and 10 to 100 μm.

In the laminate of the present invention, the layer made of polyester elastomer and the layer of microporous membrane made of polyolefin have sufficient bonding strength without using adhesives, heat fusion, or other means. Therefore, the pores of the microporous membrane made of polyolefin are not crushed by the adhesive or heat fusion, so that the properties of the microporous membrane can be fully exhibited. Of course, means such as an adhesive or heat fusion may be used depending on the purpose. As mentioned above, the reason why the layer made of polyester elastomer and the layer of microporous membrane made of polyolefin have sufficient bonding strength is probably due to the affinity between the surfaces of polyester elastomer and polyolefin. This is surprising considering that there are no polar groups on the surface.

The laminate of the present invention is preferably manufactured by the following method. That is, the moisture permeability is 1500g/rrf・24hr・25
This is a method in which a sheet of polyester elastomer with a diameter of .mu.m or more and a sheet of polyolefin containing 30 to 80% by weight of filler are laminated and then stretched. Although the thickness of the polyester elastomer sheet depends on the stretching ratio, it is generally preferably selected from a range of 5 to 60 μm in order to achieve the thickness of the polyester elastomer film of the laminate described above. On the other hand, the thickness of the polyolefin sheet is preferably selected from the range of 7 to 300 μm as described above. The filler contained in the polyolefin sheet may be either an inorganic filler or a synthetic resin filler.

As the inorganic filler, oxides, hydroxides, carbonates, or sulfates of one kind of metal selected from the group consisting of Group 1 [A, Group ■A, and Group 1VB of the periodic table] are suitable. used for. For example, metals in group mA of the periodic table include alkaline earth metals such as calcium, magnesium, and barium; metals in group 1 [[A] include metals such as boron and aluminum; As the group metal, metals such as titanium, zirconium, and hafnium are suitable. Oxides, hydroxides, carbonates, or sulfates of these metals can be used without particular limitation. In particular, more specific examples of inorganic fillers that are preferably used include calcium oxide,
Magnesium oxide, barium oxide, aluminum oxide,
Oxides such as boron oxide, titanium oxide, and zirconium oxide; Carbonates such as calcium carbonate, magnesium carbonate, and barium carbonate; Hydroxides such as magnesium hydroxide, calcium hydroxide, and aluminum hydroxide; Calcium sulfate, barium sulfate, and sulfuric acid These include sulfates of aluminum, etc.

Furthermore, synthetic resin fillers are also suitably used as the fillers used in the present invention. The above synthetic resin filler may be any known synthetic resin, including thermosetting resins and thermoplastic resins, as long as the softening temperature or decomposition temperature is higher than the molding temperature of polyolefin, preferably 10°C or higher. Available for use. If the softening temperature or decomposition temperature is lower than the polyolefin molding temperature, the synthetic resin filler will soften or decompose when forming the mixture of polyolefin and filler into a film, generating gas and making it porous. I can't. The molding temperature of polyolefin is usually 180~
It is adopted from the range of 230°C.

Specific examples of synthetic resin fillers that can be suitably used in the present invention include polyamides such as 6-nylon and 6.6-nylon; polytetrafluoroethylene, tetrafluoroethylene-hexafluoropropylene; Fluorine resins such as copolymers; poly-ramide; silicone resins; phenolic resins;
Benzoguanamine resin; or styrene, acrylic acid,
Copolymers of methacrylic acid, methyl acrylate, methyl methacrylate, etc. and crosslinking agents such as divinylbenzene are suitable.

The filler used in the present invention has an average particle size of 20 μm or less, preferably 0.01 to 5.0 μm, in order to keep the maximum pore size of the microporous membrane made of polyolefin within the above range.
Preferably, the range is m.

The blending ratio of the polyolefin and filler in the present invention is preferably selected so that the ratio of the filler to the total amount of the polyolefin and filler is 30 to 80% by weight, and more preferably 35 to 75% by weight.

The polyolefin sheet containing the above filler contains
Additives such as a polyester plasticizer, a terminal hydroxylated hydrocarbon oil, and an epoxidized oil may be added for the purpose of uniformly forming pores by the stretching described later.

In the present invention, a polyester elastomer indicated by -h and a polyolefin sheet containing 30 to 80% by weight of filler are laminated by a known method such as coextrusion or extrusion lamination, and then stretched. The polyester elastomer sheet is given good moisture permeability by stretching.
A sheet of polyolefin containing filler becomes a microporous membrane. In the case of inflation, the stretching method is either folding a cylindrical sheet and uniaxially stretching it between rolls, or biaxially stretching it using air inflation or a mandrel, or uniaxially stretching it as it is with a T-die. Furthermore, a method of biaxial stretching in a tenter or a method of simultaneous biaxial stretching is employed.

The stretching ratio is usually 1.2 times or more and 9 times or less in terms of area magnification at a temperature below the melting point of the polyolefin, preferably 10° C. lower than the melting point.

By adopting such a stretching ratio, sufficient moisture permeability can be imparted to the polyester elastomer sheet and the polyolefin sheet 1- without breaking them, and,
The bonding strength between these two layers can be made to a sufficient value.

The laminate of the present invention can be manufactured by the method described below.

The laminate of the present invention is composed of two layers, the polyester elastomer and the microporous membrane made of polyolefin, but in addition to this, a third layer is added to improve the strength of the laminate of the present invention or for other purposes. It may be laminated. The third layer may be a layer made of the above polyester elastomer,
Alternatively, it may be a layer of a microporous membrane made of polyolefin.
Furthermore, a layer made of other resin may be used. Specifically, the sheet has a three-layer structure in which a layer of a microporous membrane made of polyolefin is laminated on both sides of a layer made of polyester elastomer, or a layer made of polyester elastomer is laminated on both sides of a layer of microporous membrane made of polyolefin. Examples include laminated sheets with a three-layer structure.

(Effects) The laminate of the present invention generally has excellent moisture permeability of 2,000 to 6,000 g/po.24 hr, but exhibits water impermeability, and also has sufficient mechanical strength. Therefore, the gloves manufactured using the laminate of the present invention do not allow water or organic solvents to enter the gloves even when handling water or organic solvents containing surfactants, and the gloves do not swell inside the gloves. Nor.

In addition to the above-mentioned gloves, the laminate of the present invention is also applicable to desiccant packaging materials, medical sheets, medical gowns, surgical gowns, medicinal patch base materials, sanitary product bank sheets, clothing, windproof sheets, wall materials, and roofing materials. It can be used for materials etc.

(Examples) In order to explain the present invention more specifically, Examples and Comparative Examples are given and explained below, but the present invention is not limited to these Examples.

The properties of the laminates shown in Examples and Comparative Examples were measured by the following method.

1) Moisture permeability (g/rrr ・24 hr) JIS
20208 Moisture permeable cup method. Measured at 40°C and 90% relative humidity.

2) Air permeability [sec/100cc] JIS P811
Measured by 7.

3) Delamination strength (8/b) Measured between the eyebrows of the sample using a Tensilon at a speed of 200 mm/min.

4) Uniform whitening property The whitening unevenness of the microporous membrane layer was visually observed and evaluated according to the following criteria.

Good: Stretched uniformly and evenly: Some residual stretching was observed. Poor: Some residual stretching was observed. 5) Porosity It was calculated from the following formula by measuring the specific gravity of the layer of the microporous membrane that had been delaminated.

α0: Specific gravity of the sheet before stretching α; After stretching 6) Maximum pore diameter Determined using ethanol for the delaminated microporous membrane layer according to ASTM F316-70.

7) Leakage A sample was wrapped in a 1% aqueous solution of surfactant ABS, and tissue paper placed on the opposite side was observed for leakage. × indicates that liquid permeation is observed, O indicates that no liquid is observed.
It was displayed in

8) Tensile strength Measured in accordance with JIS P8113 (
(pulling speed: 200 mm/min) Example 1 and Comparative Examples 1 to 3 Pellets of the elastomers shown in Table 1 and the compositions shown in Table 2 B-1 were fed into a co-processor consisting of a 30 mmφ extruder, a 40 mmφ extruder, and a two-layer lower die. An unstretched sheet consisting of two layers was prepared by coextrusion using an extruder.

Then, the film was sequentially biaxially stretched by 2 times the length of Momi-Yokoo h at a temperature of 80° C. using an experimental biaxial stretching machine. Table 3 shows the results of the obtained laminate. These results show that polyester elastomers have higher glabellar peel strength than polyurethane elastomers and polyamide elastomers, and among polyester elastomers, the higher the moisture permeability, the higher the moisture permeability of the resulting laminate. Moisture permeability 1500g/24h
When using a polyester elastomer having r.
It has a moisture permeability of 24 hours or more. In addition, the maximum pore diameter of the single layer sheet obtained by stretching the pellets of the composition of B-1 under the same conditions as above was 1.4 μm, the porosity was 45%,
The moisture permeability was 5500g/nr・24hr,
Leakage was rated as x.

Table 2 Example 2.3 and Comparative Example 4.5 Polyester elastomer (Hytrel 4047, trade name Nitoshi, manufactured by DuPont ■) was used as the middle layer, and B-
Inflation molding was carried out using a 40 mmφ scale extruder using pellets of the composition No. 1 as inner and outer layers and a coextruder consisting of a three-layer circular die (150 mφ die diameter) while adjusting the discharge amount, respectively. The film was then uniaxially stretched between rolls at 40°C, and then biaxially stretched in a cylinder at 80°C. The thickness of each layer of the obtained laminate was measured using a microscope.

The results are shown in Table 4.

If the polyester elastomer layer is too thin, it will become breathable and leaky, probably due to partial rupture of the core layer. On the other hand, if it becomes too thick, the moisture permeability will decrease and the desired moisture permeability will not be achieved.

Examples 4 and 5 and Comparative Examples 6 and 7 The same polyester elastomer as in Example 2 was used as the middle layer,
After co-extruding three layers in the same manner as in Example 2 using pellets of fillers B-2 to B-5 shown in Table 2 and compositions with different filling amounts as the inner and outer layers, the respective stretching ratios were varied. Biaxial stretching was performed.

In Comparative Example 6, the porosity of the microporous membrane was low because the amount of filler was small, and as a result, it is thought that the moisture permeability was poor. Further, in Comparative Example 7, contrary to Comparative Example 6, sheet molding was impossible because the amount of filling was too large.

Examples 6 to 8 and Comparative Example 8 The same polyester elastomer as in Example 2 was used as the middle layer,
The pellets of the compositions shown in Table 2 (, -1 to 2, and D-1 were coextruded as inner and outer layers in the same manner as in Example 2, and the resulting unstretched sheet was subjected to an experimental biaxial stretching machine in Example 6. , 8 and Comparative Example 8 at 120°C, and Example 7 at 60'C.
Axially stretched. The results are shown in Table 4. In Comparative Example 8, the stretching ratio in the lateral direction was increased in order to give the porous membrane a high porosity, but the film broke, and a porous membrane with a porosity exceeding 80% could not be obtained.

Procedural amendment November 22, 1990

Claims (2)

[Claims] (1) Moisture permeability 1500g/m^2・24hr・25μ
Made of polyester elastomer with a thickness of 2 m or more
A laminate comprising a 40 μm water-impermeable layer and a microporous membrane layer made of polyolefin with a maximum pore diameter of 10 μm or less and a porosity of 20 to 80%. (2) Moisture permeability is 1500g/m^2・24hr・25μ
Production of a laminate according to claim (1), characterized in that a sheet of polyester elastomer having a diameter of 100 m or more and a sheet of polyolefin containing 30 to 80% by weight of filler are laminated and then stretched. Method.