JPH06299470A - Sheet for civil engineering - Google Patents

Abstract

PURPOSE:To obtain a sheet for civil engineering excellent in durability and hardly deteriorating the strength even under severe conditions such as high- temperature alkaline water. CONSTITUTION:The sheet for civil engineering is characterized as a mesh sheet knitted or woven from yarn, composed of core-sheath type conjugate continuous filament having a sheath component composed of at least one selected from a polyolefinic resin, a polyacrylic resin, a melamine resin, a urea resin, a fluorine-based resin and a polyamide-based resin and coated with a synthetic resin film.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a civil engineering sheet having outstanding alkali resistance, which is particularly suitable for a reinforced embankment method using concrete as a wall material.

[0002]

2. Description of the Related Art Conventionally, as a sheet-like reinforcing material (geotextile) used for a civil engineering sheet, particularly a reinforcing embankment method, a vinyl chloride resin is applied to a woven or knitted fabric made of polyvinyl alcohol fiber, for example, a weft-inserted Russell knitted fabric. The thing was adopted.

[0003]

However, such a polyvinyl alcohol fiber has a drawback that its strength is extremely reduced under high temperature water, and it has a large deterioration rate especially under high temperature alkaline water and is practical. It was something I couldn't say.

The present invention is intended to provide a civil engineering sheet which is not easily deteriorated in strength even under the severe condition of high temperature alkaline water and has excellent durability.

[0005]

The present invention proposes the following means in order to solve the above-mentioned problems. That is, the civil engineering sheet of the present invention has a core / sheath whose sheath component is composed of at least one selected from polyolefin resins, polyacrylic resins, melamine resins, urea resins, fluorine resins and polyamide resins. A mesh sheet woven and knitted with a yarn comprising a type composite long fiber, characterized in that the yarn is covered with a synthetic resin film.

[0006]

The present invention has excellent durability as a sheet-like reinforcing material for civil engineering sheets, particularly as a reinforcing embankment method using concrete as a wall material, even under the severe conditions of high temperature and strong alkaline water. As a result of diligent studies, we have conducted a thorough study to provide a civil engineering sheet with high strength, excellent dimensional stability, and excellent structure retention characteristics. As a result, we have used a core-sheath type composite fiber with a specific synthetic resin as a sheath component. It has been clarified that the above-mentioned problems can be solved by doing so.

That is, the present invention focuses on the fact that polyolefin resins, polyacrylic resins and polyamide resins are resins that have extremely high resistance to alkalis, and uses them as sheath components to make them alkaline. On the other hand, by protecting the core component, which is a relatively high strength component which is relatively weak, but has excellent dimensional stability, the above problems could be overcome successfully.

The core-sheath type composite continuous fiber referred to in the present invention is a polyacrylic resin obtained by crosslinking polyolefin resin such as polyethylene and polypropylene, polyacrylic acid, polymethacrylic acid, polyacrylic acid amide, etc. as a sheath component. The term "fiber" refers to a fiber obtained by coating a resin, a nylon 6, a nylon 66, a nylon 610 polyamide resin, a fluorine resin, a melamine resin, a urea resin, or the like, or a copolymer resin of these, and combining them.

Among these resins, a polyamide resin is preferably used in terms of alkali resistance, impact resistance, coating properties and strength retention. Among these polyamide resins, a polyamide having a relative sulfuric acid viscosity of 2.8 or more, particularly preferably in the range of 3.0 to 3.8 is preferable. As such a polyamide, nylon 6
6, more preferably a copolymer thereof, for example, a copolyamide of hexamethylene diammonium adipate and hexamethylene diammonium terephthalate. In particular, this copolyamide exhibits the property of maintaining extremely high interfacial peel resistance when polyester is used as the core component. Although the sheath component has been described above, the method for coating the sheath component may be either a melt extrusion method or a coating method.

The core component is a component that maintains and reinforces the strength and dimensional stability of the composite fiber, and the higher the strength, the more preferable.

Examples of the synthetic resin (fiber) used for the core component include polyester resin (fiber), vinylidene chloride resin (fiber), and further polyolefin fiber which is stretched to 8 times or more to have high strength. High-strength fibers such as acrylic fibers, polyvinyl alcohol fibers, and aramid fibers can be used. Among these, a polyester resin (fiber) is particularly preferably used from the viewpoint of dimensional stability and strength maintaining property.

Among such polyester resins (fibers), at least 85 mol% of repeating units are polyesters such as polyethylene terephthalate, polybutylene terephthalate and polyethylene 2,6 naphthalate, and the intrinsic viscosity of the polymer is 0.8 or more, It is more preferably 0.85 or more, and further has a density of 1.395 g /
Polyester with a size of cm ³ or more is preferable.

When the core-sheath composite type continuous fiber of the present invention is produced, for example, by a melt extrusion method, polyester and polyamide are respectively composite-spun by two extruder type spinning machines. The spinning speed is preferably 1500 m / min or more, and more preferably 2000 m / min or more. In particular, the polyester is preferably highly oriented having a birefringence of 20 × 10 ⁻³ or more, further 30 × 10 ⁻³ or more in the undrawn yarn stage. This unstretched yarn is preferably a continuous drawing method, preferably 180 ° C. or higher, more preferably 200 ° C. or higher, in two or more stages, and further in three or more stages of 1.4 to 3.5.
Stretch twice. Further, the core-sheath composite type continuous fiber of the present invention can be produced by coating the above-mentioned high-strength fiber by a coating method. That is, high strength fibers such as polyolefin fibers, acrylic fibers, polyvinyl alcohol fibers and aramid fibers which have been stretched 8 times or more to have high strength are used as polyolefin resins, polyacrylic resins, melamine resins, urea resins. At least one resin solution selected from a fluororesin and a polyamide resin is used, and this is applied or dipped to cover. This method is advantageous in that it is possible to add an impact cushioning material, an antiseptic agent or the like to the coating resin, or to form a foamed structure.

The composite ratio of the composite fibers is preferably such that 20 to 60% of the fiber weight is the sheath component. Considering the durability of the sheath component in the soil and the strong utilization factor of the core component, it is preferable to further cover in the range of 30 to 50%.

Typical cross-sectional structures of such core-sheath composite filaments are shown in FIGS. 2 is a concentric composite fiber, FIG.
Is a sea-island type composite fiber, and FIG. 4 is an example of a split type composite fiber,
Any of these core-sheath composite long fibers can be used in the present invention. In the figure, 3 is a sheath component, and 4 is a core component.

A plurality of such core-sheath type composite long fibers are bundled into a yarn. In this case, a plurality of fibers may be bundled and used without twisting, but in order to conveniently achieve the subsequent weaving and weaving characteristics, the twist coefficient K obtained by the following equation is preferably 100 to 100.
Those twisted in the range of 400, more preferably 250 to 350, are preferable.

K = T (D) ^1/2 where T is the number of twists between 10 cm and D is the total fineness of the yarn. The yarn is knitted and woven next. Tangled weave, imitation weave, 3 to 7 weft gauze fabrics are preferably used. As a knit, a warp knit, particularly a Russell knit, and particularly a weft-inserted Russell knit is preferable. Among them, the entangled weave, the three-piece woven weave, and the Russell knit are preferably used because of the ease of adjusting the film characteristics of the vinyl chloride resin and the mesh.

The mesh size of the knitted fabric is preferably adjusted to at least 0.5 cm, more preferably 1.5 to 3 cm.

The mesh sheet thus obtained is coated with a synthetic resin to be a civil engineering sheet. in this case,
The synthetic resin preferably contains a dark color pigment to shield it from ultraviolet rays. The hue of the pigment may be any dark color, but it is particularly preferable to contain carbon black.
The coating amount of the synthetic resin is about 100% or more of the weight of the yarn, more preferably 150 to 400%, especially 250 to
It is preferable to apply 350% from the viewpoint of coating properties and durability.

The synthetic resin is not limited as long as it has excellent shock buffering properties, and further has corrosion resistance and alkali resistance, but acrylic resins, vinyl chloride resins, and olefin resins are preferred. used. Among these, elastomers having excellent elasticity are preferable, and vinyl chloride resin is more preferably used.

When the synthetic resin is applied to the mesh sheet, it is preferably adjusted to a viscous liquid of at least 1000 cps, more preferably 2000 to 3000 cps. Of course, in the synthetic resin liquid, various additives such as stabilizers such as calcium stearate and barium stearate, preservatives, antioxidants, weather resistance improvers, water repellents, waterproofing agents, fillers, reinforcing materials, etc. Can be blended. The application method may be a commonly employed method such as a dipping method or a coating method.

The civil engineering sheet of the present invention thus obtained is
As shown in FIG. 1, the whole mesh sheet composed of yarns composed of the core-sheath composite long fibers 1 has a structure coated with a synthetic resin 2, particularly a vinyl chloride resin. The core component, which is a component for maintaining shape and maintaining strength, is doubly protected by the synthetic resin coating of the outer skin and the sheath component, and as a result, can withstand both strong alkali and high temperature.

[0023]

EXAMPLES The present invention will be described in more detail with reference to examples.

Example 1 The weight ratio of the polyester core component having an intrinsic viscosity of 0.85 to the polyamide sheath component having a sulfuric acid relative viscosity of 3.2 in the warp was 50:50, the single yarn fineness was 4.2 denier, and the total fineness. Is 6
The twist coefficient K of the core-sheath type composite filament of 000 denier is 31
The total fineness of the core-sheath type composite filaments, which is the same as the warp for the weft, is 3000 denier and the twist coefficient K is used.
Using the sweet twisted yarn of 301, 3 weft yarns are aligned and the warp yarn 2
A mesh-shaped woven fabric with a size of 1.5 cm in both the length and the width was created by this entangled weave, and the coating amount of a specially blended vinyl chloride resin in which carbon black was added to the woven fabric at 1.5% by weight ratio A civil engineering sheet was prepared by coating the fiber weight to 285%.

This civil engineering sheet was cut into a length of 40 cm and a width of 1 cm, and horizontally cut into a length of 40 cm and a width of 1 cm.
After the alkali resistance test of immersion for 5 days, the tensile strength and elongation were measured under the conditions of a test length of 30 cm and a pulling speed of 1.5 cm / min, and the results in Table 1 were obtained. As a result, the sheet for civil engineering was very excellent in alkali resistance, with a tenacity retention of 98.0% in length and 98.2% in width.

Example 2 For both warp and weft, the weight ratio of the polyester core component having an intrinsic viscosity of 0.85 to the polyamide sheath component having a sulfuric acid relative viscosity of 3.2 was 60:40, and the single yarn fineness was 4.2 denier. Using a sweet-twisted yarn with a twisting coefficient K of 301 for a core-sheath type composite continuous fiber having a total fineness of 3000 denier, a mesh-like woven fabric with a 1.0 cm mesh in both lengthwise and widthwise directions made of a three-piece woven fabric is created and used as the woven fabric. Carbon black is 1.5% of vinyl chloride resin weight ratio
%, A specially blended vinyl chloride resin was coated so that the applied amount was 170% of the fiber weight, and a civil engineering sheet was prepared.

This civil engineering sheet was cut into a length of 40 cm and a width of 1 cm, and in the horizontal direction, a length of 40 cm and a width of 1 cm, and treated in high temperature water at 85 ° C. for 30 minutes, and then tested. The tensile strength and elongation were measured under the conditions of a length of 30 cm and a pulling speed of 1.5 cm / min, and the results shown in Table 1 were obtained. As a result, the strength retention rate is vertical 9
The sheet was a civil engineering sheet having excellent high temperature and water resistance of 5.4% and width 94.8%.

Example 3 In the warp, the weight ratio of the polyester core component having an intrinsic viscosity of 0.85 to the polyamide sheath component having a sulfuric acid relative viscosity of 3.2 is 85:15, the single yarn fineness is 4.2 denier, and the total fineness is Is 6
The twist coefficient K of the core-sheath type composite filament of 000 denier is 31
The total fineness of the core-sheath type composite filaments, which is the same as the warp for the weft, is 3000 denier and the twist coefficient K is used.
Using the sweet twisted yarn of 301, 3 weft yarns are aligned and the warp yarn 2
A mesh-shaped woven fabric with a size of 1.5 cm in both the length and the width was created by this entangled weave, and the coating amount of a specially blended vinyl chloride resin in which carbon black was added to the woven fabric at 1.5% by weight ratio A civil engineering sheet was prepared by coating the fiber weight to 285%.

This civil engineering sheet was subjected to the same alkali resistance test as in Example 1 and then the tensile strength and elongation were measured in the same manner as in Example 1 to obtain the results shown in Table 1. As a result, the strength retention rate is vertical 6
The sheet was a civil engineering sheet having a poor alkali resistance of 8.5% and 70.0% in width.

Example 4 In the warp, the weight ratio of the polyester core component having an intrinsic viscosity of 0.85 to the polyamide sheath component having a sulfuric acid relative viscosity of 3.2 is 35:65, the single yarn fineness is 4.2 denier, and the total fineness is Is 6
The twist coefficient K of the core-sheath type composite filament of 000 denier is 31
The total fineness of the core-sheath type composite filaments, which is the same as the warp for the weft, is 3000 denier and the twist coefficient K is used.
Using the sweet twisted yarn of 301, 3 weft yarns are aligned and the warp yarn 2
A mesh-like woven fabric with a size of 1.5 cm in both length and width was created using this entangled weave, and the coating amount of a specially blended vinyl chloride resin in which carbon black was added to the fabric at 1.5% by weight ratio A civil engineering sheet was prepared by coating the fiber weight to 285%.

This civil engineering sheet was subjected to the same alkali resistance test as in Example 1, and then the tensile strength and elongation were measured by the same method as in Example 1. Further, the civil engineering sheets of Example 4, Example 1 and Example 3 were cut into a length of 50 cm and a width of 1 cm in the longitudinal direction, a gripping interval of 30 cm and a cutting strength of 60 in an atmosphere of 25 ° C.
The elongation rate (hereinafter referred to as creep rate) after the creep test in which the load of 100% was applied for 1000 hours was measured, and the results in Table 1 were obtained. As a result, the strength retention is 98.7% in the vertical direction and 98.5 in the horizontal direction.
%, It was a civil engineering sheet with very good alkali resistance. However, the creep rate was higher than those in Examples 1 and 3, and the results were unfavorable as a civil engineering sheet.

Comparative Example 1 Using polyester fibers having an intrinsic viscosity of 0.87 and a single yarn fineness of 4.2 denier, the warp has a total fineness of 6000.
A denier, sweet twisted yarn having a twist coefficient K of 310, and a weft yarn made of a sweet twisted yarn having a total fineness of 3000 denier and a twist coefficient K of 301 were used. A vinyl resin was coated to produce a civil engineering sheet.

This civil engineering sheet was subjected to the same alkali resistance test as in Example 1 and then the tensile strength and elongation were measured under the same conditions as in Example 1 to obtain the results shown in Table 1. As a result, both the strength and the elongation were significantly reduced, and the alkali resistance of the polyester fiber was significantly affected, which was not preferable as a civil engineering sheet.

Comparative Example 2 A high-strength vinylon fiber having a total fineness of 3,000 denier was used to prepare a mesh fabric made of the same three-woven cloth as in Example 2, and a vinyl chloride resin was coated in the same manner as in Example 2. I made a sheet for civil engineering.

This civil engineering sheet was treated with high temperature water in the same manner as in Example 2, and the tensile strength and elongation were measured, and the results shown in Table 1 were obtained. As a result, the strength was lowered and the elongation was increased, which was not desirable as a civil engineering sheet.

[0036]

[Table 1]

[0037]

EFFECTS OF THE INVENTION According to the present invention, there is an advantage that it is possible to provide a civil engineering sheet which is not easily deteriorated in strength even under the severe condition of high temperature alkaline water and has excellent durability.

[Brief description of drawings]

FIG. 1 is a perspective view showing an example of a civil engineering sheet of the present invention.

FIG. 2 is a cross-sectional view showing an example of a core-sheath composite long fiber used in the civil engineering sheet of the present invention.

FIG. 3 is a cross-sectional view showing another example of the core-sheath composite type long fibers used in the civil engineering sheet of the present invention.

FIG. 4 is a cross-sectional view showing another example of the core-sheath composite type long fiber used in the civil engineering sheet of the present invention.

[Explanation of symbols]

 1: Core-sheath composite type long fiber 2: Synthetic resin coating 3: Sheath component 4: Core component

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI Technical display location E02B 3/12 7150-2D E04G 21/28 B 7228-2E

Claims (11)

[Claims] 1. A core-sheath type composite long fiber whose sheath component is composed of at least one selected from a polyolefin resin, a polyacrylic resin, a melamine resin, a urea resin, a fluorine resin and a polyamide resin. A sheet for civil engineering, comprising a mesh sheet woven and knitted with the following yarn, wherein the yarn is covered with a synthetic resin film. 2. The civil engineering sheet according to claim 1, wherein the sheath component is a polyamide having a relative sulfuric acid viscosity of 2.8 or more. 3. The civil engineering sheet according to claim 1, wherein the core component of the core-sheath type composite long fibers is polyester having an intrinsic viscosity of 0.8 or more. 4. The civil engineering sheet according to claim 1, wherein the core component of the core-sheath type composite long fibers is a high-strength fiber. 5. The civil engineering sheet according to claim 1, wherein the composite ratio of the sheath component to the core-sheath type composite long fibers is in the range of 20 to 60% by weight. 6. The yarn has a twist coefficient K calculated by the following equation of 1
The civil engineering sheet according to claim 1, which is a twisted yarn in the range of 00 to 400. K = T (D) ^1/2 where T: number of twists between 10 cm, D: total fineness of yarn 7. The civil engineering sheet according to claim 1, wherein the warp of the mesh fabric is a yarn having higher strength than the weft. 8. The civil engineering sheet according to claim 1, wherein the mesh fabric has a mesh size of at least 0.5 cm. 9. The civil engineering sheet according to claim 1, wherein the mesh sheet is a entangled weave, a three-piece weave, or a Russell knit. 10. The civil engineering sheet according to claim 1, wherein the synthetic resin coating film has a coating amount of at least 100% of the fiber weight. 11. The civil engineering sheet according to claim 1, wherein the synthetic resin is a vinyl chloride resin containing a dark pigment.