JP2006045732A - Thermoplastic resin sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermoplastic resin sheet which has excellent heat retainability, collectability, and storability and is useful for mats, sunshades, house curtains and the like in an agricultural field. <P>SOLUTION: This thermoplastic resin sheet is characterized by comprising monoaxially oriented thermoplastic resin filaments, arranging the filaments through an adhesive material comprising a thermoplastic resin having a lower melting point than that of the filaments so that the filaments in one of weft direction and warp direction have a large fineness and the filaments in the other have a small fineness, and then thermally fusing the filaments. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a thermoplastic resin sheet suitable as an agricultural material such as a rug, sunshade, and in-house curtain, and more particularly to a thermoplastic resin sheet excellent in heat retention, excellent in convergence and storage.

  Sheets woven from uniaxially stretched thermoplastic resin are widely used as partitions for day coverings, house curtains, rugs, factories, etc. in the cultivation of vegetables, fruit crops, flower buds and the like.

  In the agricultural field, when used for sunshades, house curtains, etc., it is necessary to adjust the degree of covering by opening and closing frequently depending on the temperature of the field, the intensity of the sun, and the like. Also, when used as a partition, it is normally closed in a closed state, but it must be opened when the frequency of use is high.

  When opening a stretched sheet, the unfolded sheets are brought together and gathered together in one place. At this time, it is important that the gathered sheets have excellent convergence and are bundled compactly. It is. In the sheet having poor convergence, the attracted sheet becomes bulky and unnatural, and in the agricultural field, the bundled sheet creates a shadow, so that there is a problem that the intake of sunlight is deteriorated. Also, a large storage space is required for storage other than when in use.

  In addition, such a sheet is frequently subjected to mechanical stress for opening and closing, and also rubs, so that there is a problem that the warp yarn is likely to be misaligned and the sag is quick.

  On the other hand, as a sheet in the agricultural field, a film of a thermoplastic resin is often used, but because the inside humidity becomes too high, there is a problem that adversely affects crops, and as a countermeasure against high humidity to avoid this However, a woven fabric woven with a flat yarn made of thermoplastic resin is used, but there is a problem in that the warp and weft are misaligned and become unusable, and in some cases, cannot be used. For this reason, when using a flat yarn woven fabric of thermoplastic resin, a method of fixing the woven fabric by heat-sealing between the warp and weft is required as a measure for preventing misalignment.

  As a method for heat-sealing a uniaxially stretched flat yarn having a large heat shrinkage, a bonding layer made of a resin having a melting point lower than that of the base resin and having a high fusion property is generally formed on the surface of the base layer made of a crystalline resin having a large drawing effect. There is a method in which laminated heat-bondable flat yarns are woven using the warp, and after weaving, the woven fabric is heated and the warp yarns are heat-sealed.

  However, in order to provide light shielding and heat retaining properties for the curtains in the house, weaving yarn having a high fineness is used for at least one of the warp and weft. As a method for increasing the fineness, a wide flat yarn is prepared. This is converged in the width direction and rounded. That is, as shown in FIG. 5, the wide flat yarn A is converged in the width direction, and irregularly bent in the width direction to form a rounded shape. For this reason, when heat is applied to a woven fabric woven using a heat-fusible flat yarn, not only heat welding between warp and weft, but also the folded portion t of the converged flat yarn itself is fused and bonded. Therefore, the flat yarn becomes stiff and loses its flexibility, or it becomes difficult to roll because the adjacent warps or wefts are combined and solidified, and when used as a thermoplastic resin sheet, it becomes bulky when tucked up, It becomes difficult to put together compactly.

For these reasons, there has been a demand for the development of a sheet that has low durability and excellent durability even when the opening and closing frequency is high, and that maintains flexibility and has excellent convergence.
Patent No. 1796609 JP-A-11-266717

  The present invention provides a thermoplastic resin sheet excellent in heat retention and durability, excellent in convergence and storage, and suitable for rugs, sun covers, in-house curtains and the like in the agricultural field.

  The present invention has been made as a result of intensive studies to solve such problems, and specifically comprises a linear body of a uniaxially stretched thermoplastic resin, with one of the fineness of the history being increased and the other being In addition, a bonding material made of a thermoplastic resin having a melting point lower than that of the striated body is interposed between the striated bodies to form a cloth-like body, and then the striated body is thermally welded. A thermoplastic resin sheet is provided.

  Further, in the present invention, the warp yarns that are densely driven so that the filaments having a large fineness are in contact with the adjacent warp yarns and the filaments that have a small fineness are roughly driven at an interval between the adjacent weft yarns. The above thermoplastic resin sheet composed of wefts, the bonding material is formed in a tape shape in advance, and the tape material is interwoven between the filaments by weaving along the filaments. There are provided a thermoplastic resin sheet, the above-mentioned thermoplastic resin sheet in which the striated body of the background and the bonding material are made of polyolefin, and the above-mentioned thermoplastic resin sheet containing an ethylene-based polymer having a hindered amine in the side chain. Is.

  Since the thermoplastic resin sheet of the present invention uses a filament having a high fineness as a woven yarn, it has excellent heat retention, and since it has a waist, there is little sag of the sheet, and when used in the agricultural field, the efficiency of agricultural work is reduced. Can be raised.

  In addition, the thermoplastic resin sheet of the present invention can be easily tucked up, and the tucked sheet can be compactly converged, and a thermoplastic resin sheet that can be used for various purposes is obtained.

  As shown in FIG. 1, the thermoplastic resin sheet 1 of the present invention has linearly formed thermoplastic resin filaments A and B formed in a cloth shape. As the striated body, a striated body A having a high fineness and a striated body B having a small fineness are used. Usually, the striated body A having a high fineness is used as a warp and the striated body B having a low fineness is used as a weft. Made.

  As the filament A having a high fineness, a tape-like flat yarn, a split yarn obtained by opening a flat yarn with a large number of cuts in the longitudinal direction, or a multifilament in which a large number of thin filaments are bundled are used. . When flat yarns or split yarns are used, generally, wide yarns are formed and gathered in the width direction to converge and used.

  As the thermoplastic resin constituting the filament A having a high fineness, a resin having a large stretching effect, generally a crystalline resin is used. Specifically, high-density polyethylene, medium-density polyethylene, polypropylene, ethylene / α- Olefin polymers such as olefin polymers, ethylene / vinyl acetate copolymers, polyesters such as polyethylene terephthalate and polybutylene terephthalate, polyamides such as nylon 6 and nylon 66, vinylon, and the like can be used. Of these, polyolefins such as high-density polyethylene, medium-density polyethylene, and polypropylene are desirable from the viewpoint of processability and economy.

  When a multifilament is used as the striatum A, the thickness of the single fiber is preferably in the range of 0.05 to 50 dtex, and the thickness of the multifilament in which the single fibers are converged is preferably 10 to 5000 dtex. Is 100-3000 dtex. When a tape-like body such as a flat yarn is used as the linear body A, it is generally in the range of 75 to 5000 dtex and the yarn width of 2.0 to 50 mm, preferably 5.0 to 30 mm.

  Moreover, the filament A can be a composite filament obtained by laminating two or more thermoplastic resins depending on the purpose in addition to the thermoplastic resin single layer. However, when a composite filament is formed, the thermoplastic resin forming the surface can be avoided from using a resin having a low melting point that exhibits heat-fusibility in a heat treatment after forming a woven fabric, which will be described later.

  As the linear body B having a small fineness, a tape-shaped body, monofilament, or multifilament of a uniaxially stretched thermoplastic resin is used and woven, and then a joining material interposed between the linear bodies A and B 3 is joined to the filament A.

  The linear body B may be a single layer of crystalline resin as shown in FIG. 3 (a), and the base layer 5 is formed on one side of the base layer 5 as shown in FIG. 3 (b). A thermoplastic resin bonding layer 6 having a lower melting point than the thermoplastic resin can be laminated. Further, as shown in FIG. 3C, the bonding layer 6 can be laminated on both surfaces of the base layer 5. Further, as shown in FIGS. 3D and 3E, a seascore structure or a side-by-side structure may be employed.

  As the thermoplastic resin constituting the monolayer of the striatum B or the base layer 5 of the composite, a resin having a large stretching effect, generally a crystalline resin is used. Specifically, high-density polyethylene, medium density Polyolefins such as polyethylene, polypropylene, ethylene / propylene copolymers, ethylene / α-olefin polymers, ethylene / vinyl acetate copolymers, polyesters such as polyethylene terephthalate and polybutylene terephthalate, nylon 6, nylon 66, etc. Polyamide, vinylon, etc. can be used. Of these, polyolefins such as high-density polyethylene, medium-density polyethylene, and polypropylene are desirable from the viewpoint of processability and economy.

  The joining layer 6 facilitates joining between the striated body A and the striated body B, and has a lower melting point than the thermoplastic resin constituting the base layer 5 and excellent heat-fusibility. A thermoplastic resin is used. Specifically, high pressure method low density polyethylene, linear low density polyethylene, high density polyethylene, polypropylene, ethylene / propylene copolymer, ethylene / α-olefin polymer, ethylene / vinyl acetate copolymer and other olefins Olefin polymers such as polymers, polyesters such as polyethylene terephthalate and polybutylene terephthalate, polyamides such as nylon 6 and nylon 66 can be used, and the base layer in relation to the thermoplastic resin of the base layer of the linear bodies A and B A thermoplastic resin having a lower melting point, preferably 20 ° C. or higher and a lower melting point is selected. In particular, olefin polymers such as high-pressure method low-density polyethylene, high-density polyethylene, linear low-density polyethylene, and polypropylene are desirable, and linear low-density polyethylene polymerized using a metallocene catalyst is particularly preferable.

  As the linear body B with a small fineness, the thickness is preferably in the range of 10 to 2000 dtex, the yarn width is 0.5 to 10 mm, preferably 1.0 to 6 mm, and the thickness is 10 to 150 μm, preferably 20 to 20 μm. The range is 100 μm.

  An inorganic filler can be added to the thermoplastic resin forming the filament A or the filament B. As the type of inorganic filler, inorganic fillers known per se as thermoplastic resin additives can be used. For example, talc, clay, mica, calcium carbonate, barium sulfate, wollastonite, zeolite, hydrotalcite Aluminum hydroxide, magnesium hydroxide, calcium silicate, etc. can be used. By blending an inorganic filler, the texture, heat retention, or weaving can be improved. The blending amount of the inorganic filler is 1 to 40% by weight, preferably 3 to 30% by weight.

  Various additives can be added to the thermoplastic resin constituting the filament A having a high fineness or the filament B having a small fineness depending on the purpose.

  Specifically, antioxidants such as phenols, organic phosphites and phosnite, organic phosphorus and thioethers; hindered amines and other light stabilizers; benzophenone, benzotriazole and benzoate UV absorbers Nonionic, cationic and anionic antistatic agents; bisamide, wax, organometallic salt, etc. dispersant; amide, wax, organometallic salt, ester, etc. lubricant; bromine-containing organic Flame retardants such as organic, melamine, phosphoric acid, phosphoric acid ester, antimony trioxide, magnesium hydroxide, and red phosphorus; organic pigments; inorganic pigments; inorganic and organic antibacterial agents such as metal ions. In particular, when a polyolefin is used as the resin constituting the striatum A or the striatum B, it is desirable to blend an ethylene polymer having a hindered amine in the side chain.

  The above fillers or additives are appropriately combined and blended in any step of preparing the material composition. The blending of the additive may be prepared by mixing at a predetermined ratio using a kneading device such as a conventional known twin screw extruder, Banbury mixer, kneader, mixing roll, and melt-kneading the mixture. A so-called master batch having a high concentration may be prepared and used after being diluted.

  When the composite body in which the bonding layer 6 is formed is used as the linear body B, as a means for forming a laminated film as the molding material, a film to be the base layer 5 and a film to be the bonding layer 6 are formed in advance. A method of forming a multilayer using a dry laminating method or a heat laminating method, a method of coating a thermoplastic resin to be the bonding layer 6 on the surface of the film to be the base layer 5, a bonding layer to the film to be the base layer 5 previously formed 6 may be appropriately selected from known methods such as extrusion laminating or extrusion molding as a laminated film by multilayer coextrusion, but it is easy to mold and cost, and adhesion between each layer of the product. From the standpoint of the properties and light transmittance, a method of obtaining a laminated body of the base layer 5 and the bonding layer 6 in one step by a multilayer coextrusion method is desirable.

  As a method of stretching, the film to be the base layer 5 may be stretched in a uniaxial direction, and then a thermoplastic resin to be the bonding layer 6 may be laminated and slit into a tape shape, or bonded to the base layer 5. It can also be obtained by stretching in a uniaxial direction before or after slitting the laminated film on which the layer 6 is laminated.

  As a stretching method, stretching by a hot roll, stretching by a hot plate, a method of stretching by a roll in a hot air furnace, or the like can be performed. The draw ratio is 3 to 12 times, preferably about 5 to 10 times.

  As shown in FIG. 1, the obtained striated body A or striated body B is usually woven using a striated body A having a high fineness as a warp and a striated body B having a small fineness as a weft. The bonding material 3 is interposed between the filament A and the filament B. The joining material 3 joins the striated body A and the striated body B after the striated body A and the striated body B are woven, and the thermoplastic resin and the striated body constituting the striated body A and the striated body B are combined. When it is made of a body, a thermoplastic resin having a lower melting point than that of the thermoplastic resin constituting the base layer and excellent heat fusion is used.

  Specifically, high pressure method low density polyethylene, linear low density polyethylene, high density polyethylene, polypropylene, ethylene / propylene copolymer, ethylene / α-olefin polymer, ethylene / vinyl acetate copolymer and other olefins Olefin-based polymers such as polymers, polyesters such as polyethylene terephthalate and polybutylene terephthalate, polyamides such as nylon 6 and nylon 66, etc. can be used. In this connection, a thermoplastic resin having a lower melting point, preferably a lower melting point of 20 ° C. or higher is selected. In particular, olefin polymers such as high-pressure method low-density polyethylene, high-density polyethylene, linear low-density polyethylene, and polypropylene are desirable, and linear low-density polyethylene polymerized using a metallocene catalyst is particularly preferable.

  As a method of interposing the joining material 3 between the striated body A and the striated body B, the joining material is formed in a tape shape in advance and is attached to the striated body A or the striated body B at the time of weaving. Can be woven. By forming the bonding material 3 in an independent tape shape and weaving it, a sheet that can be easily converged in the length direction of the linear body B without losing the flexibility of the linear body is obtained. be able to.

  The tape-shaped bonding material 3 is usually woven along the filament A as shown in FIGS. However, depending on the purpose, it can also be woven over the filaments B. As shown in FIGS. 1 and 2, the bonding material 3 may be only on one side of the striate body, or may be attached to both sides.

  When the joining material 3 is formed in a tape shape and is interposed along the striatum during weaving, the thickness is 5 to 200 μm, preferably 10 to 50 μm, and the width is 0.5 to 10 mm, preferably Is a tape in the range of 1.0 to 6 mm. In this case, it is possible to obtain a composite in which a core material is used as the bonding material 3 and a resin excellent in heat-fusibility is laminated on both surfaces of the core material. As a method of using the bonding material 3 as a composite, a method similar to the method of obtaining the composite of the filaments B can be employed.

  As a method of weaving the joining material 3 along the filament A or the filament B, the tape-like joining material 3 and the filament A or the filament B are supplied to the loom independently. The joining material 3 can be joined to the filament B or the converged filament A depending on the purpose and supplied to the loom. You can also

  In this case, the striatum B to which the joining material 3 is joined has the same structure as the composite of the striatum B described above. Therefore, by setting the thickness of the bonding layer 6 of the filaments B to the same thickness as the bonding material 3 described above, that is, 5 μm or more, the bonding layer 6 can be used as the bonding material 3. Such a case is also included in the present invention.

  In addition, when the composite body which laminated | stacked the joining layer 6 is used as the linear body B, it is not necessary to add the joining material 3 anew, but use the tape-shaped joining material 3 according to a composite linear body. It is also a preferred embodiment. In particular, it is preferable to use a composite linear body having the bonding layer 6 as the linear body B with the tape-shaped bonding material 3 attached to the linear body A.

  The warp driving density is generally 3 to 30 / 25.4 mm, preferably 5 to 20 / 25.4 mm. It is desirable that the line A having a large fineness is dense, and it is desirable that the adjacent line A be in contact with the sheet. On the other hand, it is desirable that the filaments B having a small fineness are driven at intervals, and by driving at intervals, it becomes easy to tie them together.

Mass invention thermoplastic resin sheet 1, it is 20 to 300 g / m ² is desirable, inferior in durability and heat retention is less than 20 g / m ^2, to operate the sheet exceeds 300 g / m ² Therefore, an excessive load is applied to the wire for reducing the durability of the structure.

  The woven cloth-like body is heated to thermally weld the filaments A and B. For thermal welding, ultrasonic welding, high-frequency welding, or a hot stove can be used, but it is common to heat-weld with a hot roll.

  On both sides of the thermoplastic resin sheet 1 of the present invention, fraying can be prevented by folding back and weaving a filament B having a small fineness, which is a weft, and the end portion or the cut end portion is a tape. It can be fixed with an adhesive or a hot melt agent. It is also possible to prevent fraying by cutting the cut.

  The thermoplastic resin sheet 1 of the present invention is subjected to a treatment for making the surface hydrophilic as necessary. By the hydrophilization treatment, it is possible to prevent water droplets generated by condensation from falling on the crop. Hydrophilization treatment is a physicochemical treatment such as flame treatment, corona treatment or plasma treatment, or a method of adding a surfactant or the like into a thermoplastic resin to bleed out the resin surface, a hydrophilic resin, etc. Chemical treatment such as coating can be used. The hydrophilic treatment can be performed on the striated body before weaving, and can be performed on the sheet after weaving.

(Examples 1-3)
1. Molding of filament A A high-density polyethylene (density: 0.956 g / cm ³ , melting point: 132 ° C.) is formed into a film by an inflation method, the film is slit to a predetermined width, and then heated at a temperature of 100 ° C. It is uniaxially stretched 6.5 times in contact with the plate, further subjected to a 7% relaxation treatment in a hot air circulation oven at a temperature of 110 ° C., and the resulting flat yarn is opened with a rotating needle blade roll. A split yarn having a fineness of 1500 dt was produced.

2. Molding of striatum B Using high-density polyethylene (density: 0.956 g / cm ³ , melting point: 132 ° C.) 100% as a base layer, high-pressure low-density polyethylene (density: 0.922 g / cm ³ , melting point) : 113 ° C.) was laminated, and a two-layer three-layer film was formed by an inflation method.
After slitting the film to a predetermined width, the film is brought into contact with a hot plate at a temperature of 100 ° C., uniaxially stretched 6.5 times, and further subjected to a relaxation treatment of 5% in a hot air circulation oven at a temperature of 110 ° C. A flat yarn having a fineness of 700 dt and a width of 2 mm was formed. The ratio of surface layer: base layer: surface layer was 10:80:10.

3. Molding of bonding material 3 High-density polyethylene (density: 0.956 g / cm ³ , melting point: 132 ° C.) 100% was used as a base layer, and high-pressure low-density polyethylene (density: 0.922 g / cm ³ , melting point: 113 ° C.) was laminated, and a two-layer three-layer film was formed by an inflation method.
After slitting the film to a predetermined width, the film is brought into contact with a hot plate at a temperature of 100 ° C., uniaxially stretched 6.5 times, and further subjected to a relaxation treatment of 5% in a hot air circulation oven at a temperature of 110 ° C. The flat yarn shown in Table 1 was formed. The ratio of surface layer: base layer: surface layer was 10:80:10.

4). Weaving Using a slewer loom, the filament A and the bonding material 3 are arranged as warps, and a plain weaving fabric is formed using the filament B as a weft. The thermoplastic resin sheet shown in Table 1 was obtained by bringing them into contact with each other and thermally fusing the intersections of the warp and weft yarns.

(Comparative Example 1)
A sheet was produced in the same manner as in Example 1 except that the bonding material 3 was not used during weaving.

(Comparative Example 2)
1. Molding of the filament A A high-density polyethylene (density: 0.956 g / cm ³ , melting point: 132 ° C.) 100% was used as a base layer, and high-pressure method low-density polyethylene (density: 0.922 g / cm ³ , melting point) : 113 ° C.) was laminated, and a two-layer three-layer film was formed by an inflation method.
After slitting the film to a predetermined width, the film is brought into contact with a hot plate at a temperature of 100 ° C., uniaxially stretched 6.5 times, and further subjected to a relaxation treatment of 5% in a hot air circulation oven at a temperature of 110 ° C. The flat yarn of Table 1 was formed. The ratio of surface layer: base layer: surface layer was 10:80:10. The obtained two-type three-layer flat yarn was opened with a rotating needle blade roll to produce a split yarn having a fineness of 1500 dt.

2. Molding of striatum B A striatum B was obtained in the same manner as in Example 1.

3. Weaving Sheets were woven in the same manner as in Comparative Example 1.

[Evaluation methods]
1. Adhesive strength A woven cloth and a crochet are attached to the grip of a tensile tester, the intersection is hooked with a crochet, and the strength (cN) until the adhesion at the intersection is released is measured.
2. Flexibility According to JIS L1096 “General Textile Test Method” Flexibility A Method (45 ° Cantilever Method).

  The thermoplastic resin sheet 1 of the present invention can be used as a rug for harvesting sun-dried crops in the agricultural field. Also, as shown in FIG. When used as a house curtain, the attracted sheets are gathered into a compact bar shape, so there is no problem of drooping or blocking sunlight. Moreover, this invention thermoplastic resin sheet 1 can be used also as partitions, such as a factory.

A longitudinal sectional view showing an example of the thermoplastic resin sheet of the present invention Enlarged longitudinal sectional view showing the joining of the striatum Longitudinal section showing an example of drawn yarn The perspective view which shows the usage example of the thermoplastic resin sheet of this invention Longitudinal sectional view showing joining of striates by conventional method

Explanation of symbols

A. B. Striatum 1. 1. Thermoplastic resin sheet 2. Agricultural house Bonding material 5. Base layer 6. Bonding layer

Claims (5)

  Consists of uniaxially stretched thermoplastic resin filaments, with one of the finenesses of the history being large and the other being small, with the thermoplastic resin having a melting point lower than that of the filaments as the main component. A thermoplastic resin sheet obtained by interposing a bonding material into a cloth-like body and then thermally welding the filaments.   2. A warp in which a filament having a high fineness is densely driven so as to come into contact with an adjacent warp, and a weft in which a filament having a small fineness is roughly driven at an interval between adjacent wefts. The thermoplastic resin sheet described in 1.   The thermoplastic resin sheet according to claim 1 or 2, wherein the bonding material is formed in a tape shape in advance, and the tape-shaped body is interwoven between the linear bodies by weaving the linear body along the linear bodies. .   The thermoplastic resin sheet according to any one of claims 1 to 3, wherein the background striatum and the bonding material are made of polyolefin. The thermoplastic resin sheet according to claim 4, wherein the polyolefin contains an ethylene polymer having a hindered amine in the side chain.

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