JP2002046750A - Resin mesh-like structure and bag member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin mesh-like structure which has a sufficient flexibility and weather resistance while suppressing the increase of costs, and is excellent in mechanical strength. SOLUTION: This net 1 comprises a plurality of lateral strands 11 and a plurality of vertical strands 12. In this case, the plurality of lateral strands 11 are arranged with specified intervals. The plurality of vertical strands 12 extend in the direction orthogonal to the strands 11, and are arranged with specified intervals. Both members are combined at entangling sections (crossing sections) 13. Such a net 1 is a nonwoven net integrally formed without knitting in respective strands, and manufactured by an extrusion process or the like. Therefore, net making is not required, and the increase of costs can be suppressed. Also, respective strands 11 and 12 are made of a PVDF based resin, and durability can be increased while providing a sufficient strength. Thus, deterioration with age can be suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyvinylidene fluoride resin non-woven net and a bag member, and more particularly, to a resin net structure having a strand made of polyvinylidene fluoride resin, and the net structure having a bag. The present invention relates to a bag member formed in a shape.

[0002]

2. Description of the Related Art In a rail laying part of a railway or the like, a retaining structure for protecting a slope formed by embankment is required to prevent the outflow of sediment for a long period of time and efficiently remove only moisture during rainfall. It is required to discharge to the outside of the embankment.
Conventionally, as a measure for this, for example, (1) earth retaining material in which a cobblestone or crushed stone is filled in a metal bag member formed by meshing wires or the like called “gabion” or “futon basket”, (2)
An earth retaining material in which a filling material is filled in a bag member made of a net formed by twisting natural fibers or synthetic fibers has been used. In the bag member of (2), hemp or the like is used as a natural fiber, and nylon, polypropylene, polyester, or the like is used as a synthetic fiber.

Another method is disclosed in (3)
Japanese Patent No. -50508 discloses a method of growing plants on the sandbag surface when stacking sandbags using a bag member made of a synthetic resin net to form a soil retention.
(4) Civil engineering materials technology / technical examination certification report No. 0913
No. 1 describes a bag member using a black dyed yarn as a polyester fiber.

[0004]

However, according to the study of the present inventors, the bag member and the like used for the above-mentioned conventional earth retaining material have the following problems. That is, in the earth retaining material using the wire of (1), the wire is inferior in flexibility to follow the embankment because of inferior flexibility, and also has poor stability because a gap is generated when stacked. In addition, wire tends to rust or corrode, so that it is difficult to protect the slope for a long period of time. In addition, the bag member made of a net formed by knitting a synthetic yarn of (2) is excellent in flexibility, and the earth retaining material using the bag member has good followability to embankment and is easy to stack. However, the bag member made of such a material has a problem that it is difficult to protect the slope for a long period of time because it is deteriorated by ultraviolet rays when exposed to direct sunlight.
In particular, unstretched ones have insufficient strength and abrasion resistance, and thus tend to break easily, resulting in poor retention of the contents, that is, the filling material.

Further, the method (3) is intended to block direct sunlight to prevent deterioration of the bag member.
In the embankment of railways, it is not preferable that plants and plants grow thick from the viewpoint of ensuring safety of operation and preventing wildfire. Further, the bag member using the black dyed yarn of (4) is intended to improve the weather resistance of the bag member, but the ultraviolet light deterioration gradually progresses from the surface layer of the fiber, and the bag material also changes over time. Inevitably, the strength of the steel is reduced.

By the way, in order to improve the strength and the like while taking advantage of the bag member made of a synthetic resin having excellent flexibility, a woven mesh using a resin fiber having a higher strength and durability as a twisted yarn material. Can be considered. Examples of such a resin include polyvinylidene fluoride (hereinafter, referred to as “PVDF”) resin, and a bag member using the same is expected to have high durability for a long period of time. However, the PVDF-based resin is a relatively expensive resin among synthetic resins, and when knitting the resin fiber to form a net, the process becomes very complicated and the cost is extremely increased. There is a tendency. For this reason, the woven mesh made of the PVDF-based resin is in a situation where it is practically difficult to use.

Accordingly, the present invention has been made in view of such circumstances, and a resin net having sufficient flexibility and weather resistance and excellent mechanical strength while suppressing an increase in cost. An object is to provide a structure and a bag member.

[0008]

In order to achieve the above object, a resin net-like structure according to the present invention intersects a first strand at a predetermined angle with respect to the first strand, and A non-woven mesh having a first strand and a second strand connected to the first strand at a portion where the first strand is entangled with the first strand.
It is characterized by comprising VDF.

Since such a resin net-like structure is a non-woven net, it is not necessary to make a net like a woven net using resin fibers as a twisted yarn material, and the manufacturing process can be simplified. As a manufacturing method in this case, a combination with a known extrusion step and a stretching step that can be performed subsequently thereto can be used. In addition, since the first and second strands contain PVDF, it is possible to realize a reticulated structure having extremely excellent durability (weather resistance, environmental resistance, etc.) as compared with a conventional one using synthetic fibers, and has a sufficient effect. Strength is developed.

The resin network structure of the present invention preferably has a basis weight of 25 to 600 g / m ² , more preferably 6 g / m ² .
0 to 500 g / m ² , particularly preferably 100 to 400 g
/ M ² and a strand density of preferably 20 to 4
00 m / m ² , more preferably 30 to 200 m / m ² , particularly preferably 40 to 100 m / m ² ,
Alternatively, the second strand is preferably represented by the following formula (1); 2 ≦ Ai / Bi ≦ 50 (1), and more preferably represented by the following formula (3); 2 ≦ Ai / Bi ≦ 30 (3) It is preferable to provide them so as to satisfy the following relationship.

Here, in the formula, A indicates the area (cross-sectional area) of the entangled portion in the cross section along the extending direction of the corresponding strand, and B indicates the cross section perpendicular to the extending direction in the most detailed portion of the strand. An area (cross-sectional area) is indicated, and i is a suffix for distinguishing and indicating the first or second strand. The “strand density” in the present invention indicates the total linear length of all strands per 1 m ^{2 of} the network structure.

Alternatively, the first and / or second strand is preferably the following formula (2); 1 ≦ T / Di ≦ 5 (2), more preferably the following formula (4); 1.2 ≦ T / Di ≦ 3.5 (4) It is also preferable that the components are provided so as to satisfy the relationship represented by the following expression. Here, in the formula, T indicates the thickness of the entangled portion, D indicates the average diameter of the finest detail of the corresponding strand, and i indicates the first or second strand in the same manner as described above. It is a subscript to indicate.

In this case, the resin network structure surely exhibits excellent flexibility and sufficient mechanical strength. Further, in the case where the resin net-like structure is made into a bag shape and the inside filling material such as crushed stone is accommodated inside, it is easy to prevent the inside filling material from falling out or jumping out. Further, when the stretching is performed during the production of the resin network structure as described above, the yield point load at the entangled portion of both strands can be made larger than the contraction force of each stretched strand. This allows so-called webbing (Webb
ing; also referred to as “stringing” or “burrowing”) can be sufficiently suppressed.

More preferably, the first and second strands are made of a copolymer containing vinylidene fluoride in a proportion of 70 to 99 mol% and a monomer copolymerizable with vinylidene fluoride in a proportion of 1 to 30 mol%. Thereby, it was confirmed that the tensile elongation was significantly increased as compared with the related art while maintaining the excellent strength as the network structure. Therefore, breakage is less likely to occur when the net-like structure is made into a bag shape and a filling material such as crushed stone is stored.

The bag member according to the present invention is characterized in that the resin net structure of the present invention is formed in a bag shape. That is, the first strand is a bag that is made of a PVDF-based resin and uses a predetermined shape with respect to the first strand, which effectively utilizes the characteristics of the resin network structure of the present invention. And a non-woven net having a second strand made of a PVDF-based resin bonded to the first strand at an interlaced portion with the first strand at an angle.

[0016]

Embodiments of the present invention will be described below with reference to the accompanying drawings. Note that the same components are denoted by the same reference numerals, and redundant description will be omitted. Also, up and down, left and right,
Vertical and horizontal positional relationships are based on the positional relationships in the drawings unless otherwise specified.

FIG. 1 is a perspective view showing a preferred embodiment of a resin network structure according to the present invention, and FIG. 2 is a plan view thereof. The net 1 (resin net-like structure) includes a plurality of horizontal strands 1 extending in the X direction in the drawing and arranged at predetermined intervals.
1 (first strand) and a plurality of vertical strands 12 (second strands) extending in the Y direction in the figure and arranged at predetermined intervals. The horizontal strand 11 and the vertical strand 12 are substantially perpendicular to each other,
3 (intersection). That is, the net 1 is a non-woven net integrally formed without knitting each strand. In the following, when the horizontal strands 11 and the vertical strands 12 are collectively referred to, they are referred to as “strands 11 and 12” for convenience.

<PVDF resin> The strands 11 and 12 constituting the net 1 are made of PVDF resin. Examples of the PVDF-based resin include a homopolymer of vinylidene fluoride, that is, PVDF, a copolymer with another monomer copolymerizable with vinylidene fluoride, or a mixture thereof.

Examples of other monomers copolymerizable with vinylidene fluoride include ethylene tetrafluoride, propylene hexafluoride, ethylene trifluoride, ethylene trifluoride chloride, and vinyl fluoride. Alternatively, two or more kinds can be used as a mixture. Where each strand 1
In the case where 1,12 is formed from the above-described copolymer, practically sufficient weather resistance and mechanical strength can be obtained by containing 70 mol% or more of vinylidene fluoride. In addition, thereby, there is an advantage that the flexibility of each of the strands 11 and 12 and thus the net 1 can be improved, and the tensile elongation can be increased as compared with a conventional net made of a resin material.

More preferably, each strand 11, 12
Is a copolymer containing vinylidene fluoride in a proportion of 70 to 99 mol%, more preferably 85 to 95 mol%, and a monomer copolymerizable with vinylidene fluoride in a proportion of 1 to 30 mol%, more preferably 5 to 15 mol%. It is preferred that it be. When the content of the copolymerizable monomer is less than 1 mol%, it tends to be difficult to sufficiently exhibit properties as a copolymer, particularly, excellent flexibility.
On the other hand, when the content ratio of the copolymerizable monomer exceeds 30%, weather resistance or mechanical strength may be reduced.

<Manufacturing Method> The method of manufacturing the nonwoven net 1 is not particularly limited. For example, the net 1 can be manufactured by an extrusion step or a production method including an extrusion step and a stretching step. As the extrusion method in the extrusion process,
Conventionally known methods can be used, and specific examples include the method described in US Pat. No. 3,384,692. Although different from this, the extrusion method disclosed in JP-B-34-4185 can also be applied.

The net formed by performing this extrusion step may be used as the net 1. However, from the viewpoint of increasing the strength, the obtained extruded product (in this case, the raw material as a precursor of the net 1) is used. It is desirable to stretch in a stretching step. As a stretching method in this case, a known method can be applied, for example, Japanese Patent Publication No. 52-314.
No. 59, can be used. Alternatively, the stretching method described in JP-B-34-4185 may be used. Here, the stretching ratio is preferably approximately 3 to 5 times in both the vertical and horizontal directions. If the stretching ratio is less than 3 times, stretching unevenness may occur. On the other hand, if the stretching ratio exceeds 5 times, the strand may be broken.

<Net Shape> The net 1 is not limited to a specific shape, but is preferably configured to satisfy the following conditions. That is, the net 1 preferably has a basis weight of 25 to 600 g / m ² , more preferably 60 to 500 g / m ² , and particularly preferably 100 to 500 g / m ² .
It is 400 g / m ² . When the basis weight is less than 25 g / m ² , the mechanical strength of the net is insufficient. On the other hand, if the basis weight exceeds 600 g / m ² , sufficient flexibility may not be obtained.

The net 1 preferably has a strand density of 20 to 400 m / m ² (when the opening of the net 1 is square, the mesh size corresponds to 100 to 5 mm square), more preferably 30 to 200 m / m ^2. / M ² , particularly preferably 40 to 100 m / m ² . When the strand density is less than 20 m / m ² , when the net 1 is stored in a bag-like shape and a middle packing material such as crushed stone is stored, the middle packing material may come off. On the other hand, if the strand density exceeds 400 m / m ² , sufficient flexibility may not be obtained.

Further, the net 1 has an intersection angle θ between the horizontal strand 11 and the vertical strand 12, that is, the horizontal strand 1
1 (the X direction shown in FIG. 1) and the vertical strand 12
(The Y direction shown in FIG. 1) is desirably substantially a right angle. In this case, the net 1 has a square (rectangular) opening 15. This is a preferable mode because a decrease in the mechanical strength of the net 1 can be suppressed. At this time, it is preferable that the ratio La / Lb of the length La of the long side and the length Lb of the short side of the opening 15 be 1 to 3. If the value of this ratio is out of the above range, net 1
Tend to be unbalanced in flexibility and strength in the vertical and horizontal directions (balance is lost).

FIG. 3A is a cross-sectional view (partially omitted) of the horizontal strand 11 constituting the net 1 in the extending direction (X direction), and FIG. Figure 11 shows a cross-sectional view of detail 11a). FIG. 4A is a cross-sectional view (partially omitted) in the extending direction (Y direction) of the vertical strand 12 constituting the net 1.
B is the thinnest portion of the vertical strand 12 (the finest 12
FIG. As shown in FIGS. 3A and 4A, the interlaced portion 13 of both strands 11 and 12 indicates a region surrounded by inflection portions 13 a and 13 b where the curvature of the surface of the net 1 changes rapidly.

In the net 1, the strands 11, 1
2 preferably satisfies the relationship represented by the following formula (1); 2 ≦ Ai / Bi ≦ 50 (1), and more preferably the following formula (3); 2 ≦ Ai / Bi ≦ 30 (3) It is provided as follows. The suffix i in the expression is for distinguishing and indicating the strands 11 and 12, and the horizontal strand 11 corresponds to i = 1 and the vertical strand 12 corresponds to i = 2 (the same applies hereinafter). here,
A1 and A2 indicate the areas (see illustration) in the cross section along the extending direction (axis) of the strands 11 and 12, respectively.
B1 and B2 indicate the cross-sectional areas (see illustration) of the strands 11 and 12 at the finest details 11a and 12a, respectively.

Alternatively, in the net 1 of the present invention, the strands 11 and 12 are preferably represented by the following formula (2); 1 ≦ T / Di ≦ 5 (2), more preferably the following formula (4): 1.2 ≦ T / Di ≦ 3.5 (4) It is also preferable that they are provided so as to satisfy the relationship represented by the following expression. Here, T indicates the thickness of the entangled portion 13, and D1, D
2 indicates the average diameter of the smallest detail of each of the strands 11 and 12, and i is a suffix for distinguishing and indicating the first or second strand.

Here, the average diameters D1 and D2 are given by the following equations (5) and (6): D1 = (h1 + w1) / 2 (5), D2 = (h2 + w2) / 2 (6) It can be obtained from the relationship shown. Where h1, h
2 is the finest detail in strands 11 and 12, respectively.
1a and 12a indicate the thickness, w1 and w2 indicate the widths of the finest details 11a and 12a, respectively (see FIG. 2).

Ai / Bi in the above formula (1), or
When T / Di in the above formula (2) is less than the respective lower limit values, when the net 1 is manufactured by the extrusion process and the stretching process, the yield points of the strands 11 and 12 in the entangled portion 13 are stretched. It is difficult to make it larger than the contraction force. In this case, webbing may occur in the entangled portion 13 at the time of stretching, and the strength of the obtained net 1 may be significantly reduced or may not be practically used as a product.

On the other hand, Ai / Bi,
Alternatively, when T / Di in the above formula (2) exceeds the respective upper limit values, there is a tendency that no improvement in strength corresponding to the increase in the amount of resin in the entangled portion 13 is observed. In other words, the effect is saturated, and the resin is unnecessarily used in a large amount. In addition, the shape of the entangled portion 13 is increased, and the flatness of the net 1 is significantly reduced. Thereby, the handleability of the net 1 may be deteriorated.

According to the net 1 configured as described above,
Since the net 1 is a non-woven net that can be effectively formed by a manufacturing method such as an extrusion step or an extrusion step and a stretching step,
There is no need to form a net like a woven net using a resin fiber as a twist yarn material. In other words, the conventional yarn making process and the net making process are substantially concentrated at least in the extrusion process. Therefore, the net 1 is PVDF, which is a relatively expensive resin among synthetic resins.
Although the system resin is used, the manufacturing process can be simplified as compared with a conventional net (net-like structure) manufactured by net making, so that an increase in cost can be suppressed.

The strand 1 constituting the net 1
Since 1 and 12 are made of PVDF-based resin containing polyvinylidene fluoride, their properties such as durability, corrosion resistance, UV resistance, and scratch resistance are higher than those of conventional ones using synthetic fibers such as nylon, polypropylene and polyester. Can be significantly improved. Therefore, the net 1 with little change over time can be obtained even in a severe use environment. Therefore, long-term durability such as a bag member used for protection of a slope by filling a soil material, which is exposed to the sun or rainwater outdoors, particularly a boulder or crushed stone as a filling material, is used. This is extremely suitable as a material for a desired member.

The strand 1 constituting the net 1
When the basis weight of 1, 12 is 25 to 600 g / m ² and the strand density is 20 to 400 m / m ² , the mechanical strength as a net can be sufficiently ensured and excellent Flexibility can be reliably exhibited. Furthermore, in this case, when the net 1 is formed into a bag shape and the inside filling material is accommodated therein, it is possible to prevent the inside filling material from escaping or jumping out. Therefore, the holding property of the filling material can be improved.

Further, if the strands 11 and 12 constituting the net 1 have a shape satisfying the relationship represented by the above-described formula (1) or (2), a stretching step is required for manufacturing the net 1. When applied, the yield point load at the entangled portion 13 of the strands 11 and 12 can be made larger than the contraction force of the stretched strands 11 and 12. Thereby, the occurrence of webbing in the entangled portion 13 is suppressed. Therefore, the strength of the net 1 can be sufficiently prevented from decreasing.

Furthermore, when the strands 11 and 12 are formed from a copolymer containing vinylidene fluoride in a proportion of 70 to 99 mol% and a monomer copolymerizable with vinylidene fluoride in a proportion of 1 to 30 mol%, the net 1 The tensile elongation can be improved while maintaining excellent strength. Therefore, breakage when the net 1 is stored in a bag shape and the filling material is accommodated can be more sufficiently suppressed. In addition, if the stretching ratio at the time of performing the stretching step at the time of manufacturing the net 1 is approximately 3 to 5 times, the occurrence of stretching unevenness can be effectively prevented, and the breakage of the strands 11 and 12 can be suppressed. Therefore, net 1
In this case, it is possible to sufficiently prevent a decrease in the yield and the strength of the product in the production of the product.

FIG. 5 is a perspective view schematically showing a preferred embodiment of the bag-like member according to the present invention. Civil bag material 8
The (bag member) is the net 1 shown in FIG. 1 formed in a bag shape. More specifically, the civil engineering bag material 8 is formed in a bag shape in which the net 1 having a predetermined shape is folded at the folded portion 81 and the side ends 83 are joined by the sewing thread 85. Further, an annular mouth string passing portion 87 formed by using a sewing thread 85 is provided at the open end, and a mouth strap 89 is inserted inside the mouth portion. The open end is a bag opening 8a, from which a filling material such as crushed stone is filled.

In the civil engineering bag material 8 having such a structure, after the middle filling material is stored, the mouth cord 89 is tightened and sealed, for example, to protect the slope formed by embankment. Can be easily obtained.

Since the civil engineering bag material 8 is formed by using the net 1 according to the present invention, the durability, corrosion resistance, ultraviolet light resistance and scratch resistance are improved. Therefore, when the civil engineering bag material 8 is used as the earth retaining material, it is not necessary to protect the upper part with plants or the like as in the conventional case. Moreover, since it has sufficient abrasion resistance, breakage due to contact with or abrasion with the filling material (contents) is extremely unlikely to occur. Accordingly, the civil engineering bag material 8 can form an earth retaining material that is extremely excellent in holding the contents. In addition, the ability to follow the embankment is improved as compared with the earth retaining material using a conventional wire or the like, and the gap when stacked is small, so that the stability is excellent.

Furthermore, since the civil engineering bag material 8 has sufficient mechanical strength and weather resistance, the protection of the embankment slope where the material is installed is enhanced, and the outflow of earth and sand can be prevented more sufficiently than before. Can be deterred for a long time. As a result, there is an advantage that the frequency of renovation of the earth retaining and the like can be reduced, and the cost for the earth retaining work and the like can be significantly reduced. Furthermore, sealing (mouth closing) after the filling of the filling material is achieved by the mouth cord 89, which simplifies the process.

In each of the embodiments described above, each of the strands 11 and 12 is either the first strand or the second strand.
Strands are acceptable. Further, the opening shape of the net 1 is not limited to a square, but may be another rectangular shape such as a rhombus shape, a trapezoidal shape, or may have a curved portion. Further, various additives may be mixed with the PVDF-based resin. Further, the color of the net 1 is not limited. For example, PVDF may be used as an additive.
When a predetermined amount of carbon is added to the system resin, a black net 1 is obtained. Furthermore, the side end portion 83 of the civil engineering bag material 8
Instead of sewing with a sewing thread 85, a bag may be made by heat fusion. Further, a zipper or the like may be used in place of the mouth string 89 to seal.

Further, as another application example of the net 1, for example, there is a protection net attached to an intake piping port in a seaside plant or the like that takes in seawater or brackish water as cooling water. A large amount of marine organisms such as jellyfish may flow into such an intake pipe, which may trip the intake system. Since the net 1 of the present invention is excellent in durability, it is suitable for such a protective net. The present invention is also applicable to fishing nets used in fisheries such as fixed nets and marine cages. For example, marine organisms such as bivalves tend to attach to such fishing nets, so that the fishing nets need to be replaced frequently. Shellfish and the like tend not to adhere to a member containing a metal component, and the net 1 of the present invention is resinous, so that a metal such as copper is easily kneaded. Therefore,
If the net 1 containing a metal component is used for a fishing net, adhesion of shellfish can be suppressed. In addition, since the net 1 has high durability, there is an advantage that the frequency of replacing the fishing net can be significantly reduced.

[0043]

EXAMPLES Hereinafter, specific examples according to the present invention will be described, but the present invention is not limited to these examples.

Example 1 A vinylidene fluoride homopolymer (manufactured by Kureha Chemical Industry Co., Ltd .; KF) as a PVDF resin
(Polymer # 1000) was supplied to a single-screw extruder having a diameter of 50 mm, and the temperature of the extruder was set to 240 ° C. to melt the vinylidene fluoride homopolymer. The temperature is 240
A strand (vertical strand) in the extrusion direction (hereinafter, referred to as “MD”) and a direction perpendicular to the MD (hereinafter, referred to as “TD”) from the circular die for forming a net held at 0 ° C.
Of two strands (horizontal strands) were continuously extruded as a tubular mesh melt having rectangular openings formed at right angles.

The extruded reticulated melt is immediately cooled and solidified by a cold water shower, and then cut open in parallel with the MD.
mm and a basis weight of 1850 g / m ² was obtained. Next, the raw nonwoven fabric is stretched 4 times along the MD using a roll-type longitudinal stretching machine adjusted to a roll surface temperature of 165 ° C.
T using a tenter clip type horizontal stretching machine adjusted to
It was stretched four times along D to obtain a net which was a nonwoven net having the same shape as the net 1 shown in FIG.

Example 2 88 mol% of vinylidene fluoride and 12 parts of propylene hexafluoride were used as PVDF resin.
A nonwoven fabric web was extruded in the same manner as in Example 1 except that a copolymer (KF Polymer # 2300, manufactured by Kureha Chemical Industry Co., Ltd.) contained at a ratio of mol% was used. This raw cloth nonwoven net is stretched 4 times along the MD using a roll-type vertical stretching machine adjusted to a roll surface temperature of 140 ° C, and then a tenter clip type horizontal stretching machine adjusted to an ambient temperature of 140 ° C. And stretched 4 times along the TD using
A net which is a non-woven net having the same shape as the net 1 shown in FIG. 1 was obtained.

<Example 3> The basis weight of the nonwoven fabric web was 268.
Except that it was 0 g / m ² , a non-woven net having the same shape as the net 1 shown in FIG. 1 was obtained in the same manner as in Example 2.

<Comparative Examples 1 to 4> The following various nets were prepared as nets of the comparative example. (Comparative Example 1): Commercial product of polypropylene net (manufactured by Conwed, product name unknown, stretched) (Comparative Example 2): Commercial product of polyethylene net (product of Takiron Co., product name: TRICALNET N-) (Comparative Example 3): Commercial product of polyethylene net (manufactured by Takiron, product name: Trical net (model number unknown), undrawn), (Comparative Example 4): Commercial product of polyester filament (Toyobo multifilament, PET (1000d
/ 96F; made of 96 filaments, total 1000 denier), with stretching).

<Shape Measurement Results> The shape parameters of each net obtained in Examples 1 to 3 and each net of Comparative Examples 1 to 3 were measured. Table 1 shows the results.

[0050]

[Table 1]

For the vertical strands and horizontal strands constituting the nets of Examples 2 and 3, the smallest cross-sectional area Bi and the cross-sectional area Ai of the entangled part, and the smallest average diameter Di and the thickness of the entangled part T was measured. These measurements and / (Ai / Bi) and /
Table 2 summarizes the values of the ratio (T / Di).

[0052]

[Table 2]

<Physical property measurement test> Japanese Industrial Standard JIS L
According to the test method specified in 1043 (1978), the nets of Examples 1 to 3 and Comparative Examples 1 to 3
The tensile strength, hooking strength and tensile elongation as a net were measured. Tables 3 to 5 show these actually measured values. In addition, regarding the tensile strength and the hooking strength, the measured value was calculated as [weight per unit area / density].
The values normalized by are also shown.

[0054]

[Table 3]

[0055]

[Table 4]

[0056]

[Table 5]

From the results shown in Tables 3 and 4, it was confirmed that the nets of the examples had tensile strengths and hooking strengths equal to or higher than the conventional nets (comparative examples). Also,
The value obtained by standardizing the tensile strength and the hooking strength by [weight per unit area / density] is considered to be a kind of index that corrects the difference in the amount (weight) of the resin used. From the results of the standard values, it was recognized that the mechanical strength of the net of the example was significantly higher than that of the nets of Comparative Examples 2 and 3, which were non-woven nets.

Further, from the results shown in Table 5, it was found that the nets of the examples exhibited a tensile elongation equivalent to or higher than the conventional one. In particular, the nets of Examples 2 and 3 exhibited extremely high tensile elongation, confirming the superiority of the net of the present invention composed of strands made of PVDF copolymer. This is presumed to be due to the fact that the crystallinity of the PVDF copolymer was moderately reduced, and the ratio of the crystal part was reduced as compared with the homopolymer, so that the PVDF copolymer was easily stretched. In addition, it is considered that the tensile elongation of the resin net is unlikely to largely change even if the basis weight is different due to its characteristics. However, the operation is not limited to these.

<Weather Resistance Test 1> The nets of Example 2 and Comparative Examples 1 and 4 were subjected to a weather resistance test under the following ultraviolet (UV) irradiation and tensile test conditions. [Test equipment]: Iwasaki Electric Co., Ltd., Eye Super UV
Tester SUV-W11 [UV irradiation conditions] · UV irradiation intensity: 83mW / cm ² · UV irradiation Humidity: 60 RH%, black panel temperature: 63 ° C. [Tensile Test conditions] · sample length: 100 mm - tensile rate: 100 mm / min -Measurement items: maximum point load, maximum point stress, maximum point elongation-Measurement time: before UV irradiation, after UV irradiation, 31, 93, 1
55,310,465,620 (hr) elapsed

Using the obtained measured values, the following formulas (7) and (8): Tensile strength maintenance ratio 1 = F _i / F ₀ × 100 (7) Tensile strength maintenance ratio 2 = σ _i / σ ₀ × 100 (8) The tensile strength maintenance ratio at each irradiation time when the tensile strength before UV irradiation was set to 100% was calculated in accordance with the relationship represented by the following expression. Wherein, F _i represents the maximum point load at the time i after UV irradiation, F ₀ represents the maximum point load before UV irradiation. Σ _i indicates the maximum point stress at time i after the UV irradiation, and σ ₀ indicates the maximum point stress before the UV irradiation.

Further, according to the following equation (9); elongation retention rate = η _i / η ₀ × 100 (9), the elongation maintenance at each irradiation time when the elongation before UV irradiation is set to 100%. The rate was calculated. Where η
_i represents the maximum point elongation at time i after UV irradiation, and η ₀
Indicates the maximum point elongation before UV irradiation. Table 6 summarizes the calculation results of the tensile strength maintenance ratio 1, the tensile strength maintenance ratio 2, and the elongation maintenance ratio.

From the experience of the weather resistance test in various researches and the like by the present applicant, the 31 (hr) UV irradiation in the “weather resistance test 1” is, for example, the annual average in Arizona, USA It is assumed to be equivalent to a one-year exposure test under typical climatic conditions. Similarly, UV of 620 (hr)
Irradiation is assumed to be equivalent to the same 20 year exposure test.

[0063]

[Table 6]

As shown in Table 6, the net of Example 2 showed little change in the tensile strength maintenance rate and elongation maintenance rate (that is, all of the maximum point load, stress and elongation). On the other hand, the net of the comparative example rapidly deteriorated so that the tensile strength maintenance rate and the elongation maintenance rate both fell below 10% of the initial value at the latest at the time of UV irradiation of 31 (hr). Thereafter, it was found that the deterioration gradually progressed. From these, it was confirmed that the net of the present invention was extremely excellent in weather resistance.

Example 4 The net obtained in Example 1 was sewn to produce a civil engineering bag (width 400 mm, length 500 mm) having the same configuration as the civil engineering bag 8 shown in FIG.

Example 5 The net obtained in Example 2 was sewn to produce a civil engineering bag (width 400 mm, length 500 mm) having the same configuration as the civil engineering bag 8 shown in FIG.

<Weather Resistance Test 2> A weather resistance test was performed under the same conditions as in the weather resistance test 1 with the crushed stones filled in the civil engineering bag materials manufactured in Examples 4 and 5, and the maximum point load was No significant deterioration was observed in both the maximum point stress and the maximum point elongation.

[0068]

As described above, according to the resin network structure of the present invention, since the resin network structure is a non-woven network having a strand made of PVDF resin, an increase in cost can be suppressed. As well as being able to exhibit sufficient flexibility and weather resistance, the mechanical strength can be sufficiently improved.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a preferred embodiment of a resin network structure according to the present invention.

FIG. 2 is a plan view showing a preferred embodiment of a resin network structure according to the present invention.

FIG. 3A is a cross-sectional view in the extending direction (X direction) of a horizontal strand constituting the net shown in FIG. 1, and FIG. 3B is a cross-sectional view of the most detailed horizontal strand.

4A is a cross-sectional view in the extending direction (Y direction) of a vertical strand constituting the net shown in FIG. 1, and FIG. 4B is a cross-sectional view of the most detailed vertical strand.

FIG. 5 is a perspective view schematically showing a preferred embodiment of a bag-like member according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Net (resin net-like structure), 8 ... Civil engineering bag material (bag-like member), 11 ... Horizontal strand (1st strand), 1
1a, 12a: the smallest detail, 12: vertical strand (second strand), 13: confounding portion.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (Reference) // B29K 27:12 B29K 27:12 B29L 28:00 B29L 28:00 (72) Inventor Bunya Mizuno Ibaraki 18-13 Kamitamari, Tamari-mura, Niigata-gun, Kureha Resin Processing Technology Center, Kureha Chemical Industry Co., Ltd. Within the center (72) Inventor Takashi Abe 18-13 Kamitamari, Tamari-mura, Niigata-gun, Ibaraki Pref. HE01 4F210 AA16 AG15 QA02 QA03 QC06 QG04 QG08 QG18

Claims (6)

[Claims] 1. A first strand intersecting with the first strand at a predetermined angle and being connected to the first strand at an interlaced portion with the first strand. And a strand, wherein the first and second strands contain polyvinylidene fluoride. 2. The resin network structure has a basis weight of 25 to 600 g / m ² , a strand density of 20 to 400 m / m ² , and the first and / or second strand has the following formula: (1); 2 ≦ Ai / Bi ≦ 50 (1), A: area of the entangled portion in a cross section along the extending direction of the strand, B: cross section perpendicular to the extending direction in the finest part of the strand 2. The resin network structure according to claim 1, wherein the resin net-like structure is provided so as to satisfy a relationship represented by: i: a subscript indicating the first or second strand. 3. The weight per unit area is 25 to 600 g / m ² , the strand density is 20 to 400 m / m ² , and the first and / or second strand is represented by the following formula (2): 1 ≦ T / Di ≦ 5 (2), T: thickness of the entangled portion, D: average diameter of the smallest detail of the strand, i: suffix indicating the first or second strand, satisfying the following relationship: The resin network structure according to claim 1, which is provided as follows. 4. The first and second strands comprise 70 to 99 mol% of vinylidene fluoride and 1 to 30 mol of a monomer copolymerizable with vinylidene fluoride.
The resin network structure according to any one of claims 1 to 3, wherein the resin network structure is made of a copolymer containing at least one of the following. 5. A first strand having a bag shape and made of polyvinylidene fluoride-based resin, and a first strand intersecting with the first strand at a predetermined angle and being in contact with the first strand. A bag member comprising a non-woven net having a second strand made of polyvinylidene fluoride resin bonded to the first strand at an interlaced portion of the bag. 6. A bag member, wherein the resin net-like structure according to claim 1 is formed in a bag shape.