JPH1148418A - Oriented tape yarn and foundation cloth - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an oriented tape yarn for improving reliability, by improving heat resistant creep characteristics and heat resistant adhesive properties such as peel strength. SOLUTION: An oriented tape yarn 1 comprises a three-layer structure of an intermediate layer 2 and outer layers 3, 4 of both sides of the layer 2. As the layer 2, mixed resin of polypropylene and polyethylene polymerized by metallocene catalyst or resin obtained by further mixing high-density polyethylene with the mixed resin is used. As the layers 3, 4, resin obtained by mixing high-density polyethylene and polyethylene polymerized by metallocene catalyst or resin obtained by further mixing polypropylene with the mixed resin is used. The foundation cloth is obtained by laminating laminated films made of thermal adhesive resin on both side surfaces of woven fabric woven by the oriented tape yarn 1. Heat resistant creep characteristics of the polypropylene can be obtained. And, particularly, heat resistant adhesive strength can be improved by the polyethylene polymerized by the catalyst.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stretched tape yarn and a base fabric particularly suitable for use in a flexible container for transporting and storing powders and granules such as resin pellets, liquids and the like.

[0002]

2. Description of the Related Art Conventionally, a flexible container has been used to store powder and granular materials such as resin pellets for transportation and storage. As an example, made of polyester,
Alternatively, a container body is formed by heat fusion using a substrate made of nylon or a woven cloth coated with rubber or polyvinyl chloride, and a suspension belt is provided at approximately four equally spaced positions on the outer surface of the body of the container body. There is known a configuration in which a suspension belt holding member made of the same base material as described above and sewn is heat-sealed in the vertical direction.

[0003] As another example of a conventional flexible container, a container body is formed by sewing using a base fabric in which a laminate film made of polyolefin is laminated on both sides of a woven fabric made of a drawn tape yarn of polyolefin,
A configuration is known in which a suspension belt is sewn in a vertical direction at approximately four equally-spaced positions on the outer surface of a body portion of the container body.

By the way, flexible containers used for transporting and storing powders such as resin pellets are required to be waterproof. And, of the above-mentioned conventional examples, the former flexible container can achieve waterproofness. However, since the overall weight is large and the contents are difficult to fold when empty, labor such as carrying, folding, storing powders and the like, and cleaning the inside is required. In addition, the base material is a composite material of polyester, nylon and rubber, or polyvinyl chloride, which is difficult to separate and cannot be recycled, which is not only uneconomical but also harmful when incinerated. There was a problem such as generation of an unnecessary gas.

On the other hand, in the latter flexible container,
Although the above-mentioned problem of the former can be solved, it is constituted by sewing, and since waterproofness cannot be obtained, a cylindrical inner bag made of a polyolefin film is used in combination. However, when such an inner bag is used, storage in a flexible container,
There is a problem that the replacement work is troublesome.

[0006] Further, in the case where high-temperature resin pellets are filled in a high-temperature state, for example, the container body is required to have heat-resistant creep characteristics. Polypropylene may be used to satisfy this heat-resistant creep property, but polypropylene is inferior in weather resistance, heat sealability and the like. Therefore, in order to satisfy waterproofness, heat-resistant creep properties, weather resistance, etc., as described in the patent publication of Japanese Patent No. 2532111, weather resistance is provided on both sides of an intermediate layer made of polypropylene having excellent heat-resistant creep properties. Uses a three-layer stretch tape yarn with an outer layer of superior high-density polyethylene laminated or consists of a blend of polypropylene and linear low-density polyethylene, as described in the patent publication No. 2501670. On both sides of the middle layer, high-density polyethylene with a lower melting point than polypropylene,
A woven fabric is woven using a three-layer stretch tape yarn in which an outer layer made of linear low-density polyethylene is laminated, and low-density polyethylene, linear low-density polyethylene, and ethylene-vinyl acetate are coated on both sides of the woven fabric. There has been proposed a flexible container formed by laminating laminated films made of a polymer (EVA) or the like, and forming the laminated films of the base fabric by thermal fusion (thermal adhesion, fusion).

[0007]

The peel strength between base fabrics in such a flexible container is as follows.
Mainly, the strength of the base fabric itself, the adhesive strength between the laminate film of one base fabric and the laminate film of the other base fabric, the breaking strength of the laminate film itself, the adhesive strength between the laminate film of each base fabric and the woven fabric, When a stretched tape yarn having a layer structure is used, it is determined by the adhesive strength between the layers and the like. When the above-described stretched tape yarn having a three-layer structure is used, heat-resistant creep characteristics can be obtained by using polypropylene. However, in the former configuration using a stretched tape yarn having a three-layer structure, the above-mentioned Patent No. 25
As described in Japanese Patent Publication No. 01670, delamination tends to occur between an intermediate layer made of polypropylene and an outer layer made of high-density polyethylene, resulting in poor adhesive strength. When weaving a woven fabric with a loom as a warp and a weft using such a drawn tape yarn, delamination of the drawn tape yarn used as a warp occurs, and the peeled layer enters adjacent lead holes and straddles the lead holes. In addition, two drawn tape yarns are inserted into one lead hole after cutting, and the other lead hole has no warp, which causes not only poor weaving but also operation of the loom to stop the loom each time. The rate drops. As described above, not only is the drawn tape yarn easily delaminated, but also the adhesive strength between the woven fabric and the laminated film, between the laminated films, and between the laminated film and the woven fabric is not sufficient.

In the latter structure using a three-layer stretched tape yarn, polypropylene is mixed with a linear low-density polyethylene to form a three-layer stretch tape yarn between layers, a woven fabric and a laminate film, and a laminate film. The strength of each bond between them can be improved considerably, but still not sufficiently. Thus, in the configuration using the three-layer stretched tape yarn of any of the above-described conventional examples, particularly, both the heat-resistant creep characteristics and the heat-resistant adhesive strength of T-type peel strength including delamination are satisfied,
Sufficient reliability cannot be obtained.

[0009] Flexible containers containing powders and the like are stacked in a warehouse, a hold, or the like. At this time, the contents are compressed to reduce the volume and to wrinkle. At this time, a complex composite load such as tensile peeling or T-shaped peeling is applied to the heat-sealed portion of the container body and the heat-sealed portion of the container body and the suspension belt holding member. When the adhesive strength, particularly the T-peel strength including the adhesive strength between the layers of the stretched tape yarn, is poor as described above, the container body breaks or the heat-fused portion between the container body and the suspension belt holding member. When the container body is suspended, the container body may be detached from the suspension belt and fall down.

The present invention solves the conventional problems as described above, and can improve the heat-resistant creep characteristics and the heat-resistant adhesive strength such as delamination and T-peel strength. Accordingly, it is an object of the present invention to provide a stretched tape yarn and a base fabric capable of improving reliability.

[0011]

In order to solve the above-mentioned problems, a stretched tape yarn of the present invention comprises a high-density polyethylene and a metallocene on both sides of an intermediate layer comprising a mixed resin of polypropylene and polyethylene polymerized with a metallocene catalyst. An outer layer made of a mixed resin with polyethylene polymerized by a catalyst is laminated.

According to another aspect of the present invention, there is provided a stretched tape yarn comprising a high-density polyethylene on both sides of an intermediate layer composed of a mixed resin of polypropylene, polyethylene polymerized with a metallocene catalyst, and a high-density polyethylene.
An outer layer made of a mixed resin with polyethylene polymerized with a metallocene catalyst is laminated.

In order to solve the above problems, another stretched tape yarn of the present invention is obtained by polymerizing a high-density polyethylene and a metallocene catalyst on both sides of an intermediate layer made of a mixed resin of polypropylene and polyethylene polymerized with a metallocene catalyst. Outer layer made of mixed resin of polyethylene and polypropylene

According to another aspect of the present invention, there is provided a stretched tape yarn comprising a high-density polyethylene on both sides of an intermediate layer comprising a mixed resin of polypropylene, polyethylene polymerized with a metallocene catalyst, and a high-density polyethylene. An outer layer made of a mixed resin of polyethylene and polypropylene polymerized with a metallocene catalyst is laminated.

[0015] In order to solve the above problems, a base fabric of the present invention is obtained by laminating a laminate film made of a heat-adhesive resin on at least one outer surface of a woven fabric woven by each of the above-described drawn tape yarns. . .

The laminated film made of the heat-adhesive resin is made of polyethylene polymerized with a metallocene catalyst or a mixed resin of polyethylene polymerized with a metallocene catalyst and low-density polyethylene or linear low-density polyethylene. Although it can be formed, it has a lower melting point (e.g., DSC) than polypropylene used for drawn tape yarns, especially for heat resistance.
It is preferable to use a polyolefin having a melting point peak temperature of 110 ° C. or higher according to the method.

According to the present invention configured as described above,
The heat-resistant creep property can be improved by the polypropylene used for the intermediate layer of the stretched tape yarn. Also,
Polyethylene polymerized with a metallocene catalyst is uniform in the nature of the active site of the metallocene catalyst, has a narrow molecular weight distribution, and has a low molecular weight due to the uniform distribution of the α-olefin comonomer and narrow composition distribution. There are few low-density components, thin lamellas, and many tie molecules connecting the lamellas. Therefore, they are excellent in transparency, impact strength, tear strength, heat seal strength and the like.
By using the polyethylene polymerized with the metallocene catalyst for a stretched tape yarn or a laminated film, the heat-resistant adhesive strength such as delamination and T-peel strength can be improved.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a partially enlarged perspective view showing a stretched tape yarn according to one embodiment of the present invention,
FIG. 2 is a partially cutaway enlarged plan view showing a base fabric according to an embodiment of the present invention, FIG. 3 is a cross-sectional view taken along line AA of FIG. 2, and FIGS. FIG. 4 is a front view of a state in which a top storage port and a bottom discharge port are opened, and FIG. 5 is a state in which a storage body is closed and a chrysanthemum seat is partially closed. , FIG. 6 is a bottom view with the outlet closed, FIG. 7 is a horizontal cross-sectional view, FIG. 8 is a vertical cross-sectional view, and FIG. 9 is a heat-sealed end of a base fabric constituting a container body. It is a partially expanded sectional view of a state.

First, the drawn tape yarn will be described. As shown in FIG.
Has outer layers 3 and 4 laminated on both sides of the intermediate layer 2. The intermediate layer 2 is made of a mixed resin of polypropylene, polyethylene polymerized with a metallocene catalyst, and high-density polyethylene, and the outer layers 3, 4 are made of a mixed resin of high-density polyethylene and polyethylene polymerized with a metallocene catalyst, They are laminated in a three-layer structure by melt extrusion molding to obtain heat-resistant adhesive strength, heat-resistant creep characteristics and strength.

Next, the base fabric will be described. As shown in FIGS. 2 and 3, one or both outer surfaces of a woven fabric 5 woven with a three-layer stretched tape yarn 1 as a warp and a weft (see FIG. 2). In the illustrated example, both outer surfaces) are made of a mixed resin of polyethylene polymerized with a metallocene catalyst and low-density polyethylene, and are laminated films 6 and 7 in a molten state.
Are pressed and laminated by fusion to form the base fabric 8.

In the above embodiment, the intermediate layer 2 of the stretched tape yarn 1 having a three-layer structure is made of a resin obtained by mixing polypropylene, polyethylene polymerized with a metallocene catalyst, and high-density polyethylene. As another embodiment of the invention, a resin obtained by mixing polypropylene for the intermediate layer 2 and polyethylene polymerized with a metallocene catalyst can be used, and the outer layers 3 and 4 can be made of high-density polyethylene and In addition to a resin mixed with polyethylene polymerized with a metallocene catalyst, a resin mixed with a small amount of polypropylene can be used. As in the above embodiments, a mixed resin of polyethylene polymerized with a metallocene catalyst and low-density polyethylene can be used for the laminate films 6 and 7. As the polypropylene, it is preferable to use a random copolymer, a homopolymer, or a mixture thereof.

In each of the above embodiments, the laminate films 6, 7 on the outer surface of the woven fabric 5 in the base fabric 8 are formed of a mixed resin of polyethylene polymerized with a metallocene catalyst and low-density polyethylene. As still another embodiment of the invention, each of the laminated films 6 and 7 is formed only of polyethylene polymerized with a metallocene catalyst, or formed of a mixed resin of polyethylene polymerized with a metallocene catalyst and linear low-density polyethylene. However, in order to obtain heat resistance, the drawn tape yarn 1 having a melting point peak temperature of at least about 110 ° C.
It is preferable to use a polyolefin having a lower melting point than the polypropylene used in the above.

In the stretched tape yarn 1 having a three-layer structure, a mixture of polypropylene, polyethylene polymerized with a metallocene catalyst, and high-density polyethylene is used for the intermediate layer 2 so that the heat-resistant creep characteristic of polypropylene is improved. In addition to the strength and weather resistance of high-density polyethylene, heat-sealing strength can be improved by polyethylene polymerized with a metallocene catalyst (high-density polyethylene does not have to be used). And the outer layers 3 and 4 are delaminated, and as a result, the adhesive strength between the woven fabric 5 and the outer laminate films 6 and 7 is inferior. Mixed with polyethylene or mixed with high density polyethylene and polypropylene By it is, strength, weather resistance,
The heat sealing strength can be improved, and when polypropylene is mixed, the heat creep resistance can also be improved.

The intermediate layer 2 is made of 25% polypropylene so that the above-mentioned properties can be exhibited.
% To 90% by weight, 10% to 40% by weight of metallocene-catalyzed polyethylene, 0% to 35% by weight of high-density polyethylene, and most preferably 35% by weight of polypropylene. % To 75% by weight, 15% to 35% by weight of polyethylene polymerized with a metallocene catalyst, and 10% by weight of high density polyethylene.
It is preferable to select in the range of 30% by weight. Each outer layer 3,
In No. 4, 30% by weight to 90% by weight of high-density polyethylene
1% by weight of polyethylene polymerized with a metallocene catalyst
0% to 70% by weight, optimally 40% to 85% by weight of high density polyethylene,
15% by weight of polyethylene polymerized with metallocene catalyst
It is preferable to select in the range of ６０60% by weight. When using polypropylene for the outer layers 3 and 4,
This polypropylene is not intended to have a heat creep property as its main purpose, and can be used to make the melting point of the intermediate layer 2 close to that of the intermediate layer 2 and to improve the compatibility between the intermediate layer 2 and the outer layers 3 and 4. % To about 15% by weight, and high-density polyethylene and polyethylene polymerized with a metallocene catalyst may be reduced in response to this increase. The ratio of the thickness of the intermediate layer 2 to the thickness of the outer layer 3 is as follows:
In order to obtain the mechanical strength and the above properties as a stretched tape yarn, 50 to 80% by weight of the intermediate layer 2 is used.
The outer layers 3, 4 can be selected in the range of 10 to 25% by weight, optimally about 70% by weight of the intermediate layer 2 and each outer layer 3, 4%.
Is preferably used at about 15% by weight.

In the outer laminated films 6 and 7, the heat sealability of the low-density polyethylene can be further improved by mixing the polyethylene polymerized with the metallocene catalyst with the low-density polyethylene. I have. In the laminated films 6 and 7, the polyethylene polymerized with the metallocene catalyst can be selected in the range of 30% to 100% by weight, and the low-density polyethylene can be selected in the range of 0% to 70% by weight. It is preferable to select 40% by weight to 95% by weight of polyethylene polymerized with a metallocene catalyst and 5% to 60% by weight of low density polyethylene. These laminated films 6 and 7 may be mixed with linear low-density polyethylene instead of low-density polyethylene. By mixing the polyethylene polymerized with the metallocene catalyst with a low-density polyethylene, a linear low-density polyethylene, or the like, the viscosity can be reduced and the film can be easily formed, and therefore, the production efficiency can be reduced. It is possible to improve the waterproof property by easily embedding (penetrating) in the gap between the warp and the weft of the stretched tape yarn 1 of the woven fabric 5 and improve the adhesiveness (bonding property). When only the above is considered, the objective can be sufficiently achieved only by polyethylene polymerized with the metallocene catalyst.

As shown in FIGS. 4 to 8, a flexible container body 11 is composed of a body 12, a top 13, a bottom 14, a storage port 15, and a discharge port 16, and the body 12 has a cylindrical shape. Is formed. The storage port 15 and the discharge port 16 each include an inner cylindrical body 17 and an outer chrysanthemum seat 18.
5 is connected to the opening at the center of the top 13, the outlet 17 is connected to the opening at the center of the bottom 14, and each chrysanthemum seat 18 is an extension of the top 13 and the bottom 14. Each cylindrical body 17 is set so as to protrude from each chrysanthemum seat 18. A closing cord 20 is provided on an outer part of each cylindrical body 17.
Is attached by sewing or the like. Each Kikuza 18
A loop-shaped string 21 is formed at the leading edge of the string, and a closing string 22 is inserted through each string 21, and each closing string 22 is inserted into the fastener 23 in a parallel state outside the string 21. .

The suspension belt 24 disposed at the center of the outer surface of each side surface of the body 12 has an intermediate portion disposed on the inner side surface of the suspension belt holding member 25, and the upper and lower portions thereof are connected to the upper portion of the suspension belt holding member 25. It projects outwardly from holes 26 and 27 formed in the lower part, and the upper part is sewn to the suspension belt holding member 25 with a sewing thread 28. Suspension belt holding member 25
The long side edges of both sides are vertically fixed to the outer surface at a plurality of positions (equally divided positions at approximately 90 degrees in the illustrated example) on each side surface of the body 12, whereby the suspension belt 24 is attached to the body 12.
Mounted vertically on the outer surface of Each suspension belt 24 has a loop portion 29 formed at the tip, a lower side extending to the lower surface of the bottom portion 14, a loop portion 30 formed at the tip of the extension portion, a rope 31 inserted through each loop portion 30, and tension. In this state, both ends are tied, and the bottom portion 14 is reinforced.

In order to use the flexible container (flexible container) 32 having the above configuration, the cylinder 17 of the discharge port 16 is closed with the closing cord 20 and folded into the chrysanthemum seat 18, and then the fastener is tightened. Kikuza 1
8 is closed (see FIG. 6). Next, the cylindrical body 17 of the storage port 15
Then, a desired article such as a granular material is stored in the container body 11. After the storage, the cylindrical body 17 of the storage opening 15 is closed by the closing cord 20 and folded inside the chrysanthemum seat 18, and then the closing string 22 is pulled out from the fastener 23 to close the chrysanthemum seat 18 (see FIG. 5). Then, a hanging rope linked to the loop-shaped portion 29 of the hanging belt 24 is engaged with a hook or the like of a crane to hang the flexible container 32, load it on a truck, ship, or the like, or store it in a warehouse, an outdoor storage site, or the like. store. At this time, the bottom portion 14 of the body portion 12 is reinforced by the rope 31 and is prevented from bulging outward.

In order to discharge the articles, the flexible container 32 is suspended from a hook of a crane or the like by using the loop-shaped portion 29 of the suspension belt 24. Then, by loosening the closing cord 22 of the outlet 16 and opening the chrysanthemum seat 18, the cylinder 17 projects downward from the chrysanthemum seat 18 due to the weight of the article. Accordingly, by releasing the closing cord 20, the cylindrical body 17 is opened as shown in FIG. 4, and the article can be discharged.

It should be noted that the storage port 15 and the discharge port 16 can have a configuration other than the above-described embodiment.
An opening / closing opening may be provided only on the top portion 13 so as to be used for both storage and discharge of articles.

Container body 11 and suspension belt holding member 2
5 is constituted by the base fabric 8 shown in FIGS. As an example, a rectangular base fabric 8 for constituting the body 12 is curved in a cylindrical shape, and as shown in FIG. The cylindrical body 12 is formed by being overlapped with the laminated film 6 to be subjected to heat fusion (heat bonding, welding) at the overlapped portion. The peripheral portion of the circular base fabric 8 for forming the top portion 13 is bent, and the bent portion is formed by the laminate film 6 located inside the upper edge portion of the body portion 12 and the laminate film 7 located outside the upper edge portion of the body portion 12. The top portion 13 is formed by stacking in the same manner as described above, and performing heat fusion (thermal bonding, welding) at the overlap portion. The peripheral portion of the circular base fabric 8 for forming the bottom portion 14 is bent, and the bent portion is formed by the laminate film 6 located inside the lower edge portion of the body portion 12 and the laminate film 7 located outside the lower edge portion of the body portion 12. The bottom portion 14 is formed by stacking in the same manner as described above, and performing heat fusion (thermal bonding, welding) at the overlap portion.

Although not shown, the base fabric for forming the cylindrical body 17 of the storage opening 15 is, for example, metallocene on both sides of a woven fabric woven by a single-layer stretched tape yarn made of high-density polyethylene. A laminate film made of a mixed resin of polyethylene polymerized with a catalyst and low-density polyethylene is laminated and formed thinly, and this rectangular base fabric is curved into a cylindrical shape, and both end edges in the vertical direction are located outside. The laminated film and the laminated film located on the inner side are overlapped, and are formed into a cylindrical shape by heat-sealing (thermal bonding, welding) at the overlapped portion.
The lower edge of the cylindrical body 17 is bent outward, and the cylindrical body 1
7 is inserted into the opening at the center of the top portion 13 inside the chrysanthemum seat 18, and the bent portion is overlapped on the inside of the periphery of the opening and sewn with a sewing thread 33 to form the storage opening 15. A thin rectangular base cloth similar to the above for forming the cylindrical body 17 of the discharge port 16 is curved into a cylindrical shape, and a laminated film in which both ends in the vertical direction are located on the outside and a laminated film located on the inside. Are formed into a cylindrical shape by heat fusion (thermal bonding, welding) at the overlapped portion. The upper edge of the cylindrical body 17 is bent outward, the cylindrical body 17 is inserted into the opening at the center of the bottom 14 inside the chrysanthemum seat 18, and the bent portion is overlapped on the inner side of the peripheral edge of the opening to form a sewing thread. The cylindrical body 17 of the discharge port 16 is formed by sewing with 34. A waterproof cover 35 made of a ring-shaped base fabric 8 is superimposed on the lower surface of the bottom portion 14 at the outer peripheral portion of the discharge port 16 so as to cover the sewing portion with the sewing thread 34. Welding).

The holes 26 and 27 of the suspension belt holding member 25 made of a rectangular base cloth 8 are made of synthetic fiber woven cloth or the like,
A hanging belt 24 having excellent strength is inserted, and both are sewn with sewing threads 28. In this state, in the same manner as described above, both side edges in the vertical direction of the suspension belt holding member 25 are located on the inner side at almost equally divided positions of the body 12 at approximately 90 degrees, and the laminated film located on the outer side. 7, and are heat-sealed (heat-bonded, welded) at this overlapped portion. The suspension belt holding member 25 can be easily and quickly attached by performing heat fusion before forming the container body 11. Any one of the suspension belt holding members 25 is disposed so as to straddle the heat-sealed (heat-bonded, welded) portion of the body 12 and the body 1
2 can be thermally fused (thermally bonded, welded).

By forming the container body 11 with the base fabric 8 using the woven fabric 5 made of the drawn tape yarn 1 containing polypropylene, heat creep resistance can be obtained, and the container can be heat-sealed. By configuring the main body 11, waterproofness can be obtained, and it is suitable for filling a resin pellet or the like having a high temperature of about 60 ° C. in a high temperature state and maintaining the waterproof state.

[0035]

Embodiments of the present invention will be described below. (Example) In the intermediate layer 2 of the drawn tape yarn 1,
Polypropylene (As physical properties according to a test method based on JIS, the MFR is about 2.3 g / 10 min, and the density is about 0.
91 g / cm ³ , a Piccat softening point of about 108 ° C., a melting point of about 165 ° C.) and a metallocene-catalyzed polyethylene (MF as a physical property by a test method based on JIS)
R is about 2.5g / 10min, density is about 0.926g /
cm ³ , Piccat softening point of about 113 ° C., melting point of about 121
C) and high-density polyethylene (MFR of about 0.35 g / 10 mi as physical properties by a test method based on ASTM).
n, a density of about 0.958 g / cm ³ , a Piccat softening point of about 124 ° C., and a melting point of about 132 ° C.). And
Polypropylene, polyethylene polymerized with a metallocene catalyst, and high-density polyethylene were 45% by weight and 30% by weight, respectively.
And 25% by weight. In each of the outer layers 3 and 4 of the stretched tape yarn 1, the high-density polyethylene (MFR is about 1.0 g / 10 min and the density is 0.961 g / c as physical properties according to a test method based on JIS)
m ³ , Piccat softening point of about 128 ° C., melting point of about 135
° C) and polyethylene polymerized with a metallocene catalyst having the same physical properties as described above. Then, high-density polyethylene and polyethylene polymerized with a metallocene catalyst are mixed at a ratio of 80% by weight and 20% by weight, respectively. The intermediate layer 2 and each of the outer layers 3 and 4 are 70% by weight and 15% by weight.
It is selected to be a percentage by weight.

Each layer is co-extruded to form the intermediate layer 2 of about 0.085 mm and the outer layers 3 and 4 of about 0.018 mm each.
mm, a film having a thickness of about 0.12 mm in total was formed.
This film is slit into a width of about 14.0 mm, heated to 100 ° C. to 140 ° C. on the surface of a hot roll, stretched about 6.5 times, and the intermediate layer 2 is about 0.036 mm, and both outer layers 3 and 4 are stretched.
Was formed to a thickness of about 0.0075 mm, a total thickness of about 0.051 mm, and a width of about 5.30 mm, and then annealed and wound around a bobbin. The stretched tape yarn 1 having a three-layer structure obtained in this manner is applied to a beam of a diameter adjuster for 59 seconds.
Eight were wound up. The physical properties of the drawn tape yarn 1 were a fineness of about 238 TEX, a tensile strength of about 13.0 kg, and an elongation of about 16.8%. The drawn tape yarn 1 was woven as a warp and a weft through a weaving machine through a weaving machine so that the warp and the weft became 15 / inch, respectively, to obtain a woven fabric 5 having a woven width of 187 cm. The thickness of the woven fabric 5 was about 0.32 mm in terms of weight per square meter.

Polyethylene polymerized with a metallocene catalyst (as physical properties according to a test method based on JIS, MFR is about 4.0 g / 10 min, density is about 0.918 g / cm
³ 、 Picut softening point is about 104 ℃, melting point is about 116 ℃)
90% by weight and 10% by weight of low-density polyethylene (as physical properties according to ASTM-based test methods, MFR of about 9.0 g / 10 min, density of about 0.917 g / cm ³ , and melting point of about 107 ° C.), respectively. And the resin temperature immediately below the die lip in the laminating machine is about 270 on both outer sides of the woven fabric 5 fed from the feeding table.
Laminated films 3 and 4 having a thickness of about 0.07 mm
These were pressed with a pressure rubber roll and a cooling roll, and the thickness was about 0.7 as measured by a thickness gauge.
3mm, about 0.46mm in weight conversion per square meter
Was obtained. Regarding the physical properties of the base fabric 8, the longitudinal tensile strength and elongation were 254 kg and 14.8%, respectively, and the lateral tensile strength and elongation were 241 kg and 15.4%, respectively.

In order to form the container body 11 and the suspension belt holding member 25 thus obtained, two base cloths 8 were welded to the laminated films 7 and 6 on the outer surface by hot air welding manufactured by Quinlite Electronics Seiko. Machine LHA-208R-X
(Heater capacity: 3 kW) and heat-sealed with hot air. In this case, the temperature of the blown hot air was set at 370 ° C., and the heat sealing speed was set at 5 m / min. The tensile peel strength (shear peel strength) when applying a force to pull the base fabrics 8 in opposite directions in the extending direction is 236 kg /.
5 cm, T when applying force in the direction in which both base fabrics 8 are peeled off
The mold peel strength was 16.8 kg / 5 cm. The two base fabrics 8 were blown at the same temperature by the same welding machine as above.
It was heat-sealed to a length of 3.5 cm with hot air at 0 ° C. Then, both base fabrics 8 cut to a width of 5 cm and a length of 50 cm were pulled at a tensile speed of 30 cm / min in an atmosphere of seven stages at 20 ° C. to 80 ° C. using an instrument type autograph tester manufactured by Shimadzu Corporation. The test results of the T-peel strength when a force was applied in the peeling direction were as shown in Table 1 (in Table 1, the T-peel strength at 20 ° C. was 100% and the T-peel strength was 100%). The percentage of T-peel strength is shown in parentheses.)

[0039]

[Table 1]

In the embodiment, the container body 11,
Since the hanging belt holding member 25 is made of the same base cloth 8, the test results in Table 1 are common to the heat-sealed portion between the container bodies 11 and the heat-sealed portion between the container body 11 and the hanging belt holding member 25. It is.

The base fabric 8 is 3 cm wide and 150 cm long.
, Suspended in a constant temperature bath so as to have a length of 100 cm, the load was changed in three stages between 40 kg and 60 kg, and the temperature (ambient temperature) in the bath was set to 50 ° C. to 70 ° C.
Table 2 shows the results of measuring the load holding time until the base fabric 8 was broken at different stages.

[0042]

[Table 2]

The two base fabrics 8 were blown out at about 370 ° C. by the same hot air welding machine as described above, and were heat-sealed to a length of about 3.5 cm with hot air at a temperature. And width 3
cm, cut into length 150cm, load 30kg-50
Change between three stages between kg and ambient temperature from 50 ° C to 70 ° C
Table 3 shows the results of measuring the load holding time up to the breakage of the heat-sealed portion between the base fabrics 8 in three stages.

[0044]

[Table 3]

(Comparative Example) Polypropylene having the same properties as the above example and linear low-density polyethylene (as a physical property according to a test method based on JIS, having an MFR of about 2.1 g /
10 minutes, a density of about 0.920 g / cm ³ , a Piccat softening point of about 100 ° C., and a melting point of about 124 ° C.), and high-density polyethylene having the same physical properties as those used for the outer layer of the drawn tape yarn of the above example. Then, the polypropylene and the linear low-density polyethylene used for the intermediate layer in the stretched tape yarn having a three-layer structure are each 67% by weight,
33% by weight, high-density polyethylene and linear low-density polyethylene used for the outer layer are mixed at a ratio of 80% by weight and 20% by weight, respectively, and the intermediate layer and the outer layer are co-extruded to form an intermediate layer. Was about 0.079 mm, and both outer layers were about 0.025 mm, respectively, to form a film having a total thickness of about 0.13 mm. The film is slit to a width of about 14.3 mm, heated to 100 ° C. to 140 ° C. on the surface of a hot roll, stretched about 7 times, and the intermediate layer is about 0.031 mm, and both outer layers are about 0.01 mm each. After forming into a thickness of about 0.051 mm and a width of about 5.4 mm, annealing was performed, and the film was wound around a bobbin. 598 of the thus obtained three-layer stretched tape yarns were wound around a beam of a diameter adjuster. The physical properties of this stretched tape yarn are a fineness of about 242 TEX, a tensile strength of about 11.9 kg, and an elongation of about 1
It was 7.6%. Then, the drawn tape yarn was used as a warp and a weft and woven through a weaving machine through a weaving machine so that the warp and the weft became 15 / inch each to obtain a woven fabric having a weave width of 187 cm. The thickness of the woven fabric was about 0.33 mm in terms of weight per square meter.

Linear low-density polyethylene (as measured by an ASTM-based test method, has an MFR of about 11.0 g
/ 10 min, a density of about 0.916 g / cm ³ , a Picat softening point of about 93 ° C., and a melting point of about 108 ° C. according to a test method based on the DSC method). The resin temperature under the die lip in the laminating machine is about 290 ° C and the thickness is about 0.07m
m to form a laminated film having a thickness of about 0.75 mm as measured by a thickness gauge and about 0.47 mm in terms of weight per square meter. Got the cloth. The physical properties of this base fabric are as follows.
6%, each with a tensile strength and elongation of 246 kg
And 16.4%.

The base fabric for forming the container body and the suspension belt holding member obtained in this manner is cut into predetermined dimensions, heat-sealed in the same manner as in the above embodiment, and both base fabrics are mutually extended in the extending direction. The tensile peel strength when applying a pulling force in the opposite direction is 240 kg / 5 cm, and the T-peel strength when applying a force in the direction in which both base fabrics are peeled is 12.9 kg / 5 cm.
Met. In addition, under the same conditions as those in the above-described embodiment, the temperature was 20 ° C to 8 ° C.
Table 1 shows the results of testing the T-peel strength in an atmosphere of 0 ° C.

In the comparative example, the container body,
By configuring the hanging belt holding member with the same base cloth,
The test results in Table 1 are common to the heat-sealed portion of the container body and the heat-sealed portion of the container body and the suspension belt holding member.

Tables 4 and 5 show the results of measuring the load holding time of the base cloth of the comparative example and the heat-sealed portion between the base cloths under the same conditions as in the above example.

[0050]

[Table 4]

[0051]

[Table 5]

Among the above tests, in the tensile peel strength test, one of the base fabrics was broken at the end of the joint and the joint was peeled. Also, only the intermediate layer of the stretched tape yarn came off in a comb shape, and delamination between the outer layer and the intermediate layer of the stretched tape yarn occurred. Among these, in the case of breaking with a relatively weak force, it is considered that the cause is thermal deterioration of the base fabric itself due to the hot air temperature being too high. In the test of the T-peel strength, as a first example, when the laminated film remains on both sides of each woven fabric and peeled between layers of the laminated films, as a second example, the laminated film was broken. In a case where the woven fabric is left in the woven fabric, although it is random but is divided by 1/2, as a third example, a part of the surface of the woven fabric is further peeled off from the state of the second example, and the laminate film is formed. In some cases, material destruction occurred. First
In the example of the above, it is considered that the reason is that the laminated films did not sufficiently adhere to each other, and that the heat quantity was not sufficiently applied to the Piccat softening point and the melting point of the laminated film. In the second example, the woven fabric and the laminate film are not sufficiently bonded, and the woven fabric and the laminate film are sufficiently bonded, but the heat seal strength of the laminate film is limited. This is considered to be due to the fact that the laminate film resin was broken beyond the above. In the third example, the reason is that the heat at the time of laminating the laminate film is too high to cause thermal degradation to the woven fabric, or that the outer layer and the intermediate layer of the stretched tape yarn are peeled off. it is conceivable that.

As described above, it can be seen that the peel strength between the base cloths is improved by bonding at the optimum processing temperature according to the properties (performance) of the resin. From the results of the comparative test, the base fabric 8 according to the example of the present invention has the same tensile peel strength as that of the comparative example.
The mold peel strength, especially the T-peel strength at high ambient temperature, is excellent, and the load holding time at each load of the base fabric and the heat-sealed portion of the base fabric according to the examples is larger than that of the comparative example. It became clear that it was excellent in heat-resistant creep characteristics. To form a flexible container which is required to be waterproof and is used under high-temperature conditions, such as filling the contents in a high-temperature state, by heat-sealing the base cloth, the base cloths constituting the container body, the container The strength as a flexible container is improved by improving the tensile peel strength, T-peel strength, and heat-resistant creep properties of the base fabric constituting the main body and the base fabric constituting the hanging belt holding member, thereby obtaining reliability. However, the base fabric 8 according to the embodiment of the present invention has superior tensile peel strength, T-peel strength, and heat-resistant creep property as compared with those of the comparative example.
A waterproof container having sufficient strength can be obtained.

In the above embodiment, a mixed resin of polypropylene, polyethylene polymerized with a metallocene catalyst and high-density polyethylene was used as the intermediate layer 2 of the three-layer stretched tape yarn 1. The melting point of the mixed resin of the high-density polyethylene used as the outer layers 3 and 4 and the polyethylene polymerized with the metallocene catalyst is made as close as possible, and the same resin is used for the intermediate layer 2 and the outer layers 3 and 4 to make the mixture compatible. And the adhesiveness is improved to prevent delamination. However, almost the same effect can be obtained only by polyethylene polymerized with a metallocene catalyst. It does not have to be used. Also, polypropylene may be mixed into the outer layers 3 and 4 to help improve the adhesiveness to the intermediate layer 2 and the heat creep resistance. Further, the laminate films 6 and 7 on the outer surface side of the base fabric 8 used for the flexible container 32 of the present invention include:
If necessary, a pigment, a weather stabilizer, and other additives such as calcium carbonate may be added. Further, the suspension belt holding member 25 may be provided with a laminate film only on the side of the heat-fused surface with the body 12. Further, the base fabric 8 of the above embodiment is woven with a woven fabric having the same properties or a base fabric, or a stretched tape yarn made of high-density polyethylene and polyethylene polymerized with a metallocene catalyst, etc., and has excellent weather resistance. A woven fabric having different properties, such as a cloth or a base cloth obtained by laminating a laminate film thereon, or a combination of a base cloth and a plurality of layers can be used.

[0055]

As described above, according to the present invention, the heat-resistant creep property can be improved by the polypropylene used for the drawn tape yarn. Further, by using polyethylene polymerized with a metallocene catalyst, the polyethylene polymerized with this metallocene catalyst is uniform in the nature of the active site of the metallocene catalyst, has a narrow molecular weight distribution, and has α-olefin as a comonomer. It has a low molecular weight and few low density components due to the uniformity and narrow composition distribution, and the lamella is thin and there are many tie molecules connecting the lamellas. Therefore, transparency, impact strength, heat seal strength, etc. Is excellent. By using the polyethylene polymerized with the metallocene catalyst for a stretched tape yarn or a laminated film, the heat-resistant adhesive strength such as delamination and T-peel strength can be improved. Therefore, even under high-temperature use conditions, bag breakage and the like can be prevented, and reliability can be improved.

[Brief description of the drawings]

FIG. 1 is a partially enlarged perspective view showing a stretched tape yarn having a three-layer structure according to an embodiment of the present invention.

FIG. 2 is an enlarged plan view of a partly cutaway showing a base fabric according to an embodiment of the present invention.

FIG. 3 is a sectional view taken along line AA of FIG. 2;

FIG. 4 is a front view showing an example of a flexible container manufactured from a base fabric according to an embodiment of the present invention, with a top storage port and a bottom discharge port opened.

FIG. 5 is a plan view of the flexible container, showing a state in which the cylindrical body of the storage port is closed and the chrysanthemum seat is closed partway.

FIG. 6 is a bottom view of the flexible container, showing a state in which an outlet is closed.

FIG. 7 is a horizontal sectional view showing the flexible container.

FIG. 8 is a longitudinal sectional view showing the flexible container.

FIG. 9 is a partial cross-sectional view showing a state in which the ends of the base fabric shown in FIGS. 2 and 3 constituting the container main body in the flexible container are thermally fused to each other.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Stretched tape yarn 2 Intermediate layer 3 Outer layer 4 Outer layer 5 Woven cloth 6 Laminated film 7 Laminated film 8 Base cloth 11 Container main body 12 Body part 13 Top part 14 Bottom part 24 Hanging belt 25 Hanging belt holding member 32 Flexible container

Claims (6)

[Claims] 1. A stretch tape in which an outer layer made of a mixed resin of high-density polyethylene and polyethylene polymerized with a metallocene catalyst is laminated on both sides of an intermediate layer made of a mixed resin of polypropylene and polyethylene polymerized with a metallocene catalyst. Yarn. 2. An outer layer made of a mixed resin of high-density polyethylene and polyethylene polymerized with a metallocene catalyst is laminated on both sides of an intermediate layer made of a mixed resin of polypropylene, polyethylene polymerized with a metallocene catalyst, and high-density polyethylene. Stretched tape yarn. 3. An outer layer made of a mixed resin of high-density polyethylene, polyethylene and polypropylene polymerized with a metallocene catalyst is laminated on both sides of an intermediate layer made of a mixed resin of polypropylene and polyethylene polymerized with a metallocene catalyst. Stretched tape yarn. 4. An outer layer made of a mixed resin of high-density polyethylene, polyethylene and polypropylene polymerized with a metallocene catalyst, on both sides of an intermediate layer made of a mixed resin of polypropylene, polyethylene polymerized with a metallocene catalyst, and high-density polyethylene. Stretched tape yarn laminated with 5. A base fabric comprising a woven fabric woven by the stretched tape yarn according to any one of claims 1 to 4 and a laminated film made of a heat-adhesive resin laminated on at least one outer surface of the woven fabric. 6. The laminated film is formed of polyethylene polymerized with a metallocene catalyst, or a mixed resin of polyethylene polymerized with a metallocene catalyst and low-density polyethylene or linear low-density polyethylene. Base cloth.