JP4584772B2 - Grass protection sheet - Google Patents

Description

  The present invention relates to a herbicidal sheet that suppresses the propagation of weeds and the like.

  Conventionally, the aesthetics of buildings, structures, etc. are maintained using various weeding and weed control methods. As herbicidal means, herbicide is sprayed, but it has a temporary effect, and some herbicides are harmful.

  In addition, as a herbicidal means, a method of laying gravel or the like, or laying a sheet having a high light shielding property such as a vinyl sheet or a rubberized fabric sheet is performed. However, in the method of laying gravel, etc., gravel needs to be thickly laid to provide uniform light shielding, and weed seeds invade from the gaps in the gravel, and weeds grow from the gaps. There is. A vinyl sheet or rubberized woven sheet has no problem as in the case of gravel, but has a problem that water due to rain or the like accumulates on the sheet surface because the sheet is not water-permeable and water-proof.

On the other hand, Patent Document 1 proposes to use a spunbonded nonwoven fabric for the herbicidal sheet. However, although the spunbonded nonwoven fabric does not have the problem that water accumulates on the sheet surface as described above, the water permeability is excessive and the ground is likely to loosen due to heavy rain, and landslides are likely to occur. In addition, the spunbond nonwoven fabric is thin, and the weeding sheet using the spunbond nonwoven fabric has poor cushioning properties, and it is difficult for a person to walk on the sheet and it is torn.
Japanese Examined Patent Publication No. 4-52727

  The present invention has been made in view of the above background art, and its purpose is to prevent water from entering the ground excessively and causing landslides, and to provide excellent cushioning when a person walks on the ground. To provide a grass sheet.

  As a result of repeated studies to solve the above problems, the present inventors melted the film between the light shielding layer and the mat layer of the short fiber nonwoven fabric, and formed small holes in the film by the short fibers on the surface of the nonwoven fabric. It was found that a sheet that exhibits an appropriate water permeability that does not become excessive and has an excellent cushioning effect due to the short fiber nonwoven fabric can be obtained by combining them while being bonded.

Thus, both are a sheet in which a light shielding layer and a mat layer made of a nonwoven fabric are bonded to each other by melting a film between the layers, and the light shielding degree of the nonwoven fabric constituting the light shielding layer is 80%. The non-woven fabric constituting the mat layer is a non-woven fabric made of short fibers, the film is a film made of an olefin polymer having a melting point of 95 ° C. or less , and the film has a thickness of 55 to 90 μm. Thus, there is provided a weedproof sheet having holes formed as described above, and having a water permeability of 1 × 10 ⁻² cm / s or less.

  In the herbicidal sheet of the present invention, the light shielding layer and the mat layer are joined by melting the film interposed therebetween, and appropriate holes are formed in the film due to the short fibers on the nonwoven fabric surface constituting the mat layer. Therefore, water does not enter the ground excessively and landslides are unlikely to occur. Moreover, since the said herbicidal sheet | seat consists of a nonwoven fabric which a light shielding layer has a high light-shielding degree, even if a film is easy to be weather-resistant deteriorated, this deterioration is prevented and it can be used for a long term. Furthermore, since the weedproof sheet of the present invention is excellent at the time of cushioning, it has an advantage that it is easy to walk and work on it.

  The herbicidal sheet of the present invention is a sheet in which a light shielding layer and a mat layer made of nonwoven fabric are joined to each other by melting a film between the layers.

  The nonwoven fabric forming the light shielding layer and the nonwoven fabric forming the mat layer may be the same or different. The fibers used in these nonwoven fabrics are preferably thermoplastic synthetic fibers such as polyamide fibers, polyolefin fibers, and polyester fibers. Among them, polyester fibers, particularly polyethylene terephthalate fibers are more preferable from the viewpoint of weather resistance and mechanical properties.

  In the present invention, the nonwoven fabric used for the light shielding layer may be a nonwoven fabric made of long fibers or a nonwoven fabric made of short fibers, but the nonwoven fabric constituting the mat layer needs to be a nonwoven fabric made of short fibers. This will be described in detail later. In addition, as a fineness of said nonwoven fabric, all are preferable 3.0-22.0 dtex.

In the present invention, the light shielding degree of the nonwoven fabric constituting the light shielding layer is 80% or more, the nonwoven fabric constituting the mat layer is a nonwoven fabric made of short fibers, the film has holes, and the water permeability of the sheet Is 1 × 10 ⁻² cm / s or less. Thereby, it is possible to provide a weedproof sheet that does not cause landslide, has good cushioning properties when a person walks, and is not torn. Hereinafter, each requirement will be described.

  Also, many films that are between the light-shielding layer and the matte layer and that fuse both layers are prone to weathering deterioration, and this problem can be solved by setting the light-shielding degree of the nonwoven fabric constituting the light-shielding layer to 80% or more. Long-term use is possible. In addition, the herbicidal effect is also improved by ensuring the light shielding degree.

Furthermore, the mat layer must be a non-woven fabric made of short fibers. When the light-shielding layer and the mat layer are melted and bonded to each other, the short fibers on the non-woven fabric surface penetrate the film and have small holes. And the appropriate water permeability that is the object of the present invention can be realized.

  The fiber length of the fibers constituting the nonwoven fabric is preferably in the range of 30 to 1500 mm, and the fineness of the fibers can be in the range described above. The nonwoven fabric is preferably a nonwoven fabric formed by mixing fibers having different fiber lengths or finenesses, and the water permeability (water permeability coefficient) can be adjusted by the mixing ratio of these fibers. If it is going to raise water permeability from this viewpoint, it is preferable that the nonwoven fabric which comprises the light shielding layer mentioned above is also a nonwoven fabric which consists of a short fiber.

  Further, since the mat layer is a non-woven fabric made of short fibers, it has excellent cushioning properties and has an effect that it is easy for a person to walk on the sheet or to work on the sheet. In particular, when the mat layer is a nonwoven fabric in which short fibers are entangled by a needle punch, the effect of the cushioning property is more remarkable.

From the viewpoint of ease of walking and work, it is desirable that the thickness of the mat layer is 5 mm or more and less than 30 mm, and the basis weight is 500 g / m ² or more and less than 3000 g / m ² . When the thickness is 30 mm or more, the workability tends to be poor when the sheet is laid, whereas when the thickness is less than 5 mm, the cushioning property tends to be low.

  The film used in the present invention preferably has a melting point of 95 ° C. or lower, and more preferably can withstand substantially a heat-sealing treatment at 120 ° C. As such a film, an olefin polymer is preferable, and polyethylene is particularly preferable. The thickness of the film is preferably 55 to 90 μm from the viewpoint of permeability. That is, by setting the thickness of such a film, when the film is melted, the fibers on the surface of the nonwoven fabric constituting the mat layer penetrate the film to form appropriate holes, and the weedproof sheet having a water permeability coefficient described below. Easy to do.

In the present invention, the water permeability coefficient of the weedproof sheet needs to be 1 × 10 ⁻² cm / s or less. If the permeability coefficient exceeds 1 × 10 ⁻² cm / s, not only will the water penetrate into the ground on rainy days, the ground will loosen, the walking and workability will deteriorate, but in extreme cases, landslides will occur. Is likely to occur. On the other hand, if the water permeability is too low, water tends to accumulate on the surface of the herbicidal sheet, and therefore, the water permeability is preferably 1 × 10 ⁻⁴ cm / s or more.

  The weedproof sheet of the present invention described above can be produced by the following method. That is, it can be produced by laminating a film on the non-woven fabric constituting the mat layer, and further laminating the non-woven fabric constituting the light-shielding layer on the non-woven fabric, and then passing it through a calender roll and melting the film. . In this case, when the film is the olefin polymer described above, it is preferable that the calender roll temperature is in the range of 130 to 150 ° C. and the calender setting clearance is in the range of 1.0 to 25 mm. This makes it possible to use the short fibers on the surface of the non-woven fabric to form appropriate pores having the above-mentioned water permeability coefficient in the film and at the same time firmly bond the light shielding layer and the mat layer.

Hereinafter, the present invention will be described more specifically with reference to examples. In addition, each characteristic in an Example was evaluated with the following measuring method.
(1) Unit area mass (weight)
It measured according to the method prescribed | regulated to JISL-1908.
(2) Thickness It was measured according to the method specified in JIS L-1908.
(3) Tensile strength It measured according to the method prescribed | regulated to JISL-1908.
(4) Tensile elongation rate It measured according to the method prescribed | regulated to JISL-1908.
(5) Water permeability coefficient It measured according to the method prescribed | regulated to JISL-3204.
(6) Light shielding ratio It measured according to the method prescribed | regulated to JIS L-1096 A method.
(7) Sunshine weather resistance test It measured according to the method prescribed | regulated to JISB7751 method.

[Example 1]
A web obtained by opening a polyester short fiber having a fineness of 9 dtex and a fiber length of 100 mm through a carding process is entangled under a condition of 221 points / cm ² by a needle punch, and the basis weight is 360 g / m ² . A light shielding layer having a light shielding property of 99 was prepared.

Further, 60% by weight of polyester short fibers having a fineness of 6.6 dtex and a fiber length of 51 mm, 10% by weight of polyester short fibers having a fineness of 9.0 dtex and a fiber length of 64 mm, a fineness of 11.0 dtex, and fiber length The web obtained by blending 30% by weight of polyester short fiber having a length of 64 mm with a blender and opening in the carding process is subjected to a entanglement treatment under the condition of 200 points / cm ^{2 with} a needle punch, and the thickness is 6 mm. A mat layer having a basis weight of 660 g / m ² was prepared.

  Next, an olefin-based film (“Kurabetta A-1510” manufactured by Kurashiki Boseki Co., Ltd., 75 μm) is laminated on the mat layer prepared above, and the light-shielding layer is further laminated using a heating calendar roll. The clearance of the calender roll was 3 mm, the calender temperature was 140 ° C., and the olefin-based film was melted to join the light shielding layer and the mat layer to obtain a herbicidal sheet. The results are shown in Table 1.

In addition, five people who chose arbitrarily walked on the obtained herbicidal sheet, and it was evaluated that the cushioning property was extremely high. In addition, this weedproof sheet was laid directly on the ground, and the water permeation situation in rainy weather was confirmed. As shown in the water permeability coefficient of Table 1, water permeated appropriately and the ground did not loosen. Furthermore, the same result was obtained with the weedproof sheet after the weather resistance test.
Moreover, the said weedproof sheet had sufficient mechanical characteristics, and the problem that the weedproof sheet was torn even when used for a long time did not occur.

[Comparative Example 1]
The light-shielding layer and the matte layer were not thermally fused using an olefin film, but these layers were laminated and bonded by needle punching under the condition of 100 points / cm ² as in Example 1. Similarly, a herbicidal sheet was obtained. The results are shown in Table 1.

  The cushioning property was evaluated in the same manner as in Example 1, but the cushioning property was similar to that in Example 1. Moreover, although the water permeation | transmission condition at the time of rain was confirmed similarly to Example 1, water penetration was large as the water permeability coefficient of Table 1 showed, and the looseness of the ground was confirmed. Furthermore, the same results were obtained for the weedproof sheet after the weather resistance test.

[Comparative Example 2]
A herbicidal sheet was obtained in the same manner as in Example 1 except that a polyester long-fiber nonwoven fabric having a light shielding degree of 60% (BT-0605W manufactured by Unicel Corp., basis weight 30 g / m ² ) was used as the light shielding layer. The results are shown in Table 1.

  The cushioning property was evaluated in the same manner as in Example 1, but the cushioning property was slightly worse than that in Example 1. Moreover, although the water permeation | transmission condition at the time of rain was confirmed like Example 1, water permeate | transmitted moderately as the water permeability coefficient of Table 1 showed, and the ground did not loosen. However, the herbicidal sheet after the weathering test showed deterioration of the film, and as shown by the water permeability coefficient in Table 1, water penetration also increased, confirming the looseness of the ground.

  In the herbicidal sheet of the present invention, the light shielding layer and the mat layer are joined by melting a film interposed therebetween, and appropriate holes are formed in the film due to the short fibers on the surface of the nonwoven fabric constituting the mat layer. Therefore, water does not enter the ground excessively and landslides are unlikely to occur. Moreover, since the said herbicidal sheet | seat consists of a nonwoven fabric which has a high light-shielding degree in a light shielding layer, even if a film is easy to be weather-resistant, this deterioration is prevented and long-term use is possible. Furthermore, since the weedproof sheet of the present invention is excellent at the time of cushioning, it has a merit that it is easy to walk and work on it. For this reason, the herbicidal sheet of the present invention can be widely used as a sheet to be laid around places such as roads, rivers, tracks, etc., where the aesthetics around buildings and structures are maintained. The utility value is extremely high.

Claims (3)

Both are a sheet in which a light shielding layer and a mat layer made of a nonwoven fabric are bonded to each other by melting a film between the layers, and the light shielding degree of the nonwoven fabric constituting the light shielding layer is 80% or more. Yes, the non-woven fabric constituting the mat layer is a non-woven fabric composed of short fibers, the film is a film composed of an olefin polymer having a melting point of 95 ° C. or less and a thickness of 55 to 90 μm, and the film is penetrated by short fibers A herbicidal sheet having formed holes and having a water permeability of 1 × 10 ⁻² cm / s or less. The thickness of the mat layer is less than 30mm above 5 mm, and a weight of less than 500 g / ^{m 2} or more 3000 g / ^{m 2,} weed sheet according to claim 1.   The weedproof sheet according to claim 1 or 2, wherein the nonwoven fabric constituting the mat layer is a nonwoven fabric in which short fibers are entangled with a needle punch.