JPH0250836A - Bag material - Google Patents

Abstract

PURPOSE:To obtain a bag material having excellent resistance against the piercing caused by a sharp edge and the cutting-in of an edge tool by laminating a synthetic resin polymer film or sheet having an m.p. lower than that of a specific synthetic resin polymer stretched material to the crosswise laminate of said stretched material. CONSTITUTION:A synthetic resin polymer stretched material has tensile strength of 20g/denier or more, pref., 30g/denier or more and a cross-sectional area of 0.1mm<2> or more and a certain number of the stretched materials are laminated so as to cross each other at a right angle or at a predetermined angle to constitute a crosswise laminate (piercing-resistant layer). To both surfaces of the crosswise laminate of said synthetic resin polymer stretched material or to the single surface thereof, a synthetic resin polymer film or sheet having an m.p. lower by 5 deg.C or more than that of said synthetic resin polymer stretched material is applied and all of them are integrated using a heating pressure molding means. As the synthetic resin polymer, a polyethylene, an ethylene/vinyl acetate copolymer and an ethylene/ethyl acrylate copolymer can be designated. By using these materials, a bag material having good release resistance can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a bag material that has excellent resistance to penetration by sharp objects, cutting by knives, etc.

[Prior Art] There is a demand for materials for bags that have excellent resistance to penetration by sharp objects and resistance to cuts by blades. As one bag material that can meet these demands, a material made by laminating a synthetic resin polymer on a knitted fabric of wholly aromatic polyamide fibers has been proposed.

In other words, since fully aromatic polyamide fibers are materials with high tensile strength and elastic modulus, knitted fabrics made of fully aromatic polyamide fibers have a lower basis weight compared to ordinary aliphatic polyamide fiber knitted fabrics such as nylon 6 and nylon 66. It is expected that it will exhibit similar or better physical properties in terms of quantity, that is, resistance to penetration by sharp objects and resistance to cuts by knives.

However, this bag material made by laminating a synthetic resin polymer to a knitted fabric made of fully aromatic polyamide fibers does not exhibit the expected penetration resistance. It may easily penetrate the weave. Possible means to overcome these drawbacks include making the stitches or weaves of the knitted fabric smaller, or stacking the knitted fabric in multiple layers. However, even if these measures are adopted, the weight of the bag material increases, and the penetration resistance cannot be improved to the extent expected.

[Problems to be Solved by the Invention] The present invention has been made in view of these circumstances, and provides a bag material that exhibits excellent resistance to penetration by sharp objects and cuts by knives. The purpose is to

[Means for Solving the Problems] The bag material of the present invention that achieves the above object is a stretched synthetic resin polymer having a cross-sectional area of 0.1 mm2 or more and a tensile strength of 20 g/denier or more. The gist lies in that a synthetic resin polymer film or sheet having a melting point lower by at least 5° C. than the melting point of the stretched synthetic resin polymer is laminated on the cross-laminated product.

[Function] As a result of intensive studies to solve the above problems, the present inventors have developed a cross-laminated body of a stretched synthetic resin polymer having a tensile strength above a certain level and a large cross-sectional area as a penetration resistance layer. The present inventors have discovered that the material employed as a cut-resistant layer exhibits excellent resistance to cuts made by cutlery and penetration by sharp objects, leading to the completion of the present invention.

That is, the stretched synthetic resin polymer forming the penetration resistance layer of the bag material according to the present invention has a tensile strength of 1.20 g/denier or more, preferably 30 g/denier or more, and
It is a stretched product having a cross-sectional area of 0.1 mm 2 or more, and is laminated so as to cross each other at right angles or at a predetermined angle to form a cross laminate (penetration resistance layer). An example of such a stretched synthetic resin polymer is JP-A-61-10103.
The synthetic resin polymer drawn product (super-highly polymerized polyolefin drawn product such as ultra-highly polymerized polyethylene tape) disclosed in No. 2 can be mentioned, and when a polyethylene stretched product is used as the stretched product, it is advantageous in terms of weight reduction. Even better effects can be obtained.

If the tensile strength of the stretched synthetic resin polymer is less than 20 g/denier, cuts by a knife are likely to occur;
If the cross-sectional area of the stretched product is less than 0.1 mm 2 , when a sharp object is pierced, it often does not hit the stretched synthetic resin polymer, resulting in low penetration resistance.

Furthermore, the stretched product has a cross-sectional flattening ratio of 5 as defined below.
It is desired that the value is 0 or more, and thereby the penetration resistance and the cutting resistance can be further improved. The above-mentioned cross-sectional flattening ratio means a value calculated by a/b, where the major axis length in the cross section of the stretched synthetic resin polymer is a mm and the minor axis length is b mm.

In the present invention, a synthetic resin polymer film having a melting point 5° C. or more lower than the melting point of the stretched synthetic resin polymer is provided on both sides or one side of the cross-laminated body of the stretched synthetic resin polymer as described above. Alternatively, a sheet is attached and the two are integrated using means such as heating and pressure molding.

The reason why the melting point difference between the stretched synthetic resin polymer product and the synthetic resin polymer film or sheet is set to 5°C or more is to prevent thermal deterioration (and thus decrease in strength) of the stretched synthetic resin polymer product during heating and pressure molding. The purpose is to maintain wettability between the stretched synthetic resin polymer film or sheet and the synthetic resin polymer film or sheet.
This makes it possible to increase resistance to penetration by sharp objects and resistance to cutting by knives, and to create a bag in which the stretched synthetic resin polymer cross laminate and the synthetic resin polymer are difficult to separate when pierced by sharp objects. materials can be obtained. Conversely, if the difference in melting point between the stretched synthetic resin polymer film or sheet is less than 5°C, the temperature at which the strength of the stretched synthetic resin polymer film or sheet is less likely to decrease (i.e., the temperature at which the strength of the stretched synthetic resin polymer film or sheet Since heating and pressure molding must be carried out at a temperature (lower than the melting point of If a sharp object is pierced, peeling will occur easily. On the other hand, if the heating/pressing molding temperature is increased to a temperature at which the above-mentioned wettability becomes good, the strength decrease due to thermal deterioration of the stretched synthetic resin polymer increases, and the cut resistance with a knife deteriorates. Examples of the synthetic resin polymer for the film or sheet that satisfy the requirements of the present invention include polyethylene, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, ethylene-maleate ester copolymer, etc. By using these materials, bag materials with good peeling resistance can be obtained.

When the Shoraiko awning material is used for a shoulder bag or the like, it is desirable that the total thickness of the bag material obtained by heating and pressure molding is 0.1 to 3 mm. Thickness: 0.
If the thickness is less than 1 mm, it is not only difficult to increase the resistance to penetration and cutting by a knife, but also to form various patterns by embossing the surface of the bag, which results in limited designs. I don't get it. On the other hand, if the thickness exceeds 3 mm, the flexibility of the bag material decreases, resulting in a decrease in commercial value as a shoulder bag or the like.

In addition, when using the light bag material for travel trunks, etc., the thickness of the bag material after heating and pressure molding should be 2 to 10 m.
It is desirable to set it to m. If the thickness is less than 2 mm, the rigidity will be insufficient, while if the thickness exceeds 10 mm, the weight of the bag material will increase too much, resulting in a decrease in commercial value as a travel trunk or the like.

[Examples] Example 1 A bag material was constructed using a stretched polyethylene product and a polyethylene film having the following physical properties.

(Stretched polyethylene product) Tensile strength: 3og/denier (JIS L 10
13) Cross-sectional area = 613 denier≠0.1 mm2 (polyethylene film) Density: 0.92 g/cm3 (JIS K 678
0) Melting point = 102℃ (Measurement method: same as above) Thickness:
0.1 mm That is, on the polyethylene film, the polyethylene stretched products are arranged at 1 mm intervals to form a first resistance layer, and the polyethylene stretched products are arranged on the polyethylene film in a direction perpendicular to the arrangement direction of the first resistance layer. A second resistance layer was formed by arranging the resistors at intervals of in+m. Furthermore, after sequentially arranging a third resistance layer (in the same arrangement direction as the first resistance layer) and a fourth resistance layer (in the same arrangement direction as the second resistance layer) on the second resistance layer, A polyethylene film of the same quality as the above polyethylene film with a thickness of 0.3 mm was placed, and heated at 135°C with a weight of 10 kg/
A bag material was obtained by heating and pressurizing for 5 minutes under conditions of cm2.

SKS tungsten steel cutter (circular blade 45 mm manufactured by Olfa Co., Ltd.) on the crosshead of the Tensilon type testing machine
A push cut test was carried out on the bag material by attaching a crosshead and moving the crosshead at a speed of 50 mm/min. The average cutting stress when the test was conducted three times was 12 kg.

Next, a sharp object shown in FIG. 1 was attached to the crosshead of a Tensilon type testing machine, and the crosshead was moved at a speed of 500 mm/min to perform a penetration test on the bag material. The average penetration stress when the test was conducted three times was 17 kg.

Example 2 The following ethylene-vinyl acetate copolymer film and Example 1
A bag material was produced in the same manner as in Example 1 using the stretched polyethylene.

(Ethylene-vinyl acetate copolymer film) Density:
0.93g/cm3 (JIS K 6760) Melting point: 9
0℃ (Measurement method is the same as above) Thickness: 0.1
mm and 0.3 mm When the obtained bag material was subjected to a push cut test and a penetration test in the same manner as in Example 1, the average cutting stress was 11 kg and the average penetration stress was 15 kg.

Example 3 A bag material was manufactured in the same manner as in Example 1 using the following ethylene-maleate copolymer film and the stretched polyethylene product of Example 1.

(Ethylene-maleate ester copolymer film) Density: 0.95g/cm3 (JIS K 6760
) Melting point: 67°C (Measurement method is the same as above) Thickness: 0.1 mm and 0.3 mm When the obtained bag material was subjected to a push-cut test and a penetration test in the same manner as in Example 1, the average cutting stress was was 11 kg, and the average penetrating stress was 14 kg.

Example 4 A bag material was manufactured in the same manner as in Example 1 using the following polyethylene sheet and the stretched polyethylene product of Example 1.

(Polyethylene sheet) Density: 0.96g/cm” (JIS K 87
80) Melting point = 130℃ (Measurement method is the same as above)
Thickness: 1 mm and 3 mm When the obtained bag material was tested in the same manner as in Example 1, the average cutting stress was 23 kg and the average penetration pressure was 45 kg.

Comparative Example 1 Fully aromatic polyamide multifilament (Kevlar 49 multifilament manufactured by DuPont, total fineness 1211 denier, number of filaments 768 wood, tensile strength 16 g/denier) was used for the warp and weft, and both warp density and weft density were A plain weave of 17 wood/inch was woven. This was used as a resistance layer, and vinyl chloride sheets with a thickness of 0.3 mm were attached to both sides of the resistive layer, and a bag material was obtained by heating and pressurizing at 170° C. and 10 kg/cm 2 for 5 minutes.

When the bag material was subjected to the same test as in Example 1, the average cutting stress was 8 kg, and the average penetrating stress was 11 kg.
Met.

Comparative Example 2 A plain woven fabric with a warp density and a weft density of 22 wood/inch was woven using the following polyethylene multifilament for the warp and weft.

(Polyethylene multifilament) Total fineness: 1600 denier Number of filaments + 1560 tensile strength: 30 g/denier (JIS 678
0) Melting point, 145°C (Measurement method is the same as above) The obtained plain woven fabric was used as a resistance layer, and the polyethylene films described in Example 1 were attached to both sides of the resistive layer.
A bag material was obtained by heating and pressurizing for 5 minutes under the condition of 10 kg/c+n2. When the bag material was subjected to the same test as in Example 1, the average cutting stress was 10 kg.
, the average penetrating stress was 12 kg.

[Effects of the Invention] The present invention is configured as described above, and the effects summarized below can be obtained.

(1) The bag material of the present invention has a cross-laminated body made of a stretched synthetic resin polymer with high tensile strength and a large cross-sectional area as a resistance layer, so it has excellent resistance to penetration by sharp objects and cuts by knives. Demonstrates high resistance.

(2) Since we use a synthetic resin polymer film or sheet with a melting point 5°C or more lower than the melting point of the synthetic resin polymer stretched product, it has good wettability during heat and pressure molding, and can be used with sharp knives. Even when punctured, the cross laminate is unlikely to peel off from the film or sheet, and has excellent durability.

(3) Despite having the above-mentioned excellent mechanical properties, it is lightweight.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the shape of a sharp object used in the penetration resistance test.

Claims (1)

[Claims] The cross-sectional area is 0.1mm^2 or more and 20g
/denier or more, and a synthetic resin polymer film or sheet having a melting point lower than the melting point of the stretched synthetic resin polymer by at least 5°C or more than the melting point of the stretched synthetic resin polymer. A bag material characterized by: