JP2006214119A - Artificial turf - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide safe and comfortable artificial turf which is akin to natural turf. <P>SOLUTION: This artificial turf 4 comprises a pile 1 and a pile base material 2 wherein the pile 1 is implanted. At least either of the pile 1 and the base material 2 contains a water-containing gel 1c which has a tensile break strength of 0.3 MPa or more, a breaking elongation of 20% or more, a compressive break stress of 5 MPa or more, a compressive-break uniaxial deformation of 50% or more and a moisture content of 30-100 wt%, and wherein a drying rate in the open environment at 10% or more relative humidity at 25°C is 50% or less of weight in wet base per hour. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention is laid on the ground for sports such as outdoor or indoor soccer, rugby, baseball, hockey, artificial ski resorts, physical education facilities such as schools, stadiums for mass games, etc., roofs and walls of buildings and houses, etc. The present invention relates to a safe and comfortable artificial turf that is close to natural turf as a laying material that replaces natural turf.

  Conventionally, various proposals have been made and put into practical use as materials and laying materials used for sports grounds and the like instead of natural turf. For example, an artificial turf that is close to natural turf with excellent shock absorption is proposed and put to practical use by filling a pile of nylon or polypropylene with fine sand and fine rubber chips. Or the device which provides the touch close | similar to natural grass similarly by providing the pile of nylon or polyethylene in multiple steps, or using the pad which is excellent in cushioning properties. However, due to the characteristics of the materials, there is a great risk of injury such as burns due to frictional heat when the athlete falls, and measures such as spraying water as appropriate are taken to prevent this, but the ball gets wet. In many cases, there is a risk that the athlete will slip or the athlete will slip.

In view of this, methods and materials have been proposed in which moisture is retained in the artificial turf to prevent burns during a fall. For example, a method using a porous membrane or porous hollow fiber containing a deliquescent substance inside (see Patent Document 1), a method using a hydrophilic pile thread made of natural or synthetic fibers (see Patent Document 2) , A method of spraying water-absorbing resin fine particles on artificial turf (see Patent Document 3), a method of including water in a vinyl chloride microcapsule (Patent Document 4), a tufted pile using a water-absorbing polymer as a primary base fabric (See Patent Document 5), a method using a hollow fiber containing a hydrophilic polymer as a pile thread (Patent Document 6), and the like are known. However, in these methods, if a hydrophilic polymer material is made to have sufficient moisture content, problems arise in its strength and feel, so that it still has mechanical properties and feel equivalent to those of natural turf. No laying thing has been obtained.
Japanese Patent No. 2837764 Japanese Unexamined Patent Publication No. 6-033412 Japanese Patent No. 3245974 Japanese Patent No. 3401651 Japanese Patent Laid-Open No. 7-324276 JP 2000-027113 A

  In order to solve the above problems, even if it has a sufficient moisture content, it has sufficient mechanical properties, has flexibility and freedom of frictional resistance on the surface, It has a high degree of processing freedom that enables the application of fibers, filaments, films, etc., which are usually used for manufacturing, and compounding, piling, etc. of blending, lamination, etc., by adding UV absorbers and coloring agents, etc. It is important to find a material that has a degree of freedom of modification, and more importantly, a cost that can be used in large quantities and a validity of the manufacturing method.

  More importantly, the properties of the material do not cause a sudden change in use, so even if it has a sufficient moisture content, the change is moderate or abrupt depending on the moisture content. It is desirable not to have a mutation point that causes a change in physical properties.

  Based on the recognition of the above-mentioned problems of the prior art and the problems to overcome it, the inventors of the present application have conducted research and research to find a suitable material, and as a result, have specifically identified the water-containing gel. However, even in a highly water-containing state, it has been found that there is a special water-containing gel that has mechanical strength such as surprising strength and elongation, and also has a large degree of freedom in variability of surface friction resistance (Jian Ping Gong et al., ADVANCED MATERIALS 2003.15, No. 14, 1155-1158 (2003), Japanese Patent Application Laid-Open No. 2002-212252).

  By forming an artificial turf that takes advantage of the characteristics of the above-mentioned unique hydrogel, the present invention can impart properties close to natural turf to the artificial turf, and solve the problems of the existing and known techniques described above. The artificial turf of the present invention comprises a pile and a pile base material on which the pile is planted, and at least one of the pile and the pile base material has a tensile breaking strength of 0. .3 MPa or more, elongation at break of 20% or more, compressive fracture stress of 5 MPa or more, uniaxial deformation of compression fracture of 50% or more, moisture content of 30% by weight or more and 100% by weight or less in an open environment at 25 ° C. and a relative humidity of 10% or more The water-containing gel has a drying rate of 50% or less of the water-containing weight per hour.

  The water-containing gel includes a crosslinked structure composed of an acrylamide or methacrylamide polymer of an organic acid of carboxylic acid, sulfonic acid and phosphoric acid containing an alkyl group having 2 to 10 carbon atoms, carboxylic acid, sulfonic acid, and It can be constituted by having a double cross-linked structure with a cross-linked structure made of acrylamide or methacrylamide-based polymer that does not contain any phosphoric acid.

  This water-containing gel has sufficient mechanical properties such as high breaking strength and breaking elongation in the state that it has sufficient moisture to prevent injury and burns due to friction such as overturning. As a material, it has necessary and important characteristics, and its use greatly improves the disadvantages and problems of the prior art.

  Furthermore, this hydrogel may be compounded with other non-hydrogel polymer materials, and in this way, the mechanical properties, feel and safety close to natural turf, which has been considered difficult to solve, are satisfied. Is useful.

  More specifically, in addition to adjusting the average composition, composition in the vicinity of the surface, and the degree of crosslinking, a pile formed by combining such a hydrogel with a non-hydrogel polymer material such as nylon or polyolefin at an appropriate ratio. By planting (piling) on the pile base material, it is possible to achieve the feel, elasticity, moisture content, drying rate, etc. that are close to natural turf. By replenishing the pile, it is possible to maintain a constant moisture content, feel and physical properties in the pile.

  There are no particular limitations on the method for combining the water-containing gel and the non-water-containing gel polymer material as described above in order to obtain physical properties and feel close to natural turf. Various methods such as mixing of water-containing gel polymers can be considered, but a pile of a film-like non-water-containing gel polymer coated on the water-containing gel so as to include the water-containing gel inside, or sandwiched between the water-containing gels A pile laminated with a film of non-hydrogel polymer material sandwiched between them is an effective means for realizing a state close to natural turf without exposing a hydrogel containing a large amount of water to the pile surface.

  In addition, the non-hydrated gel polymer material that covers the surface should be given a moderate moisture, or a continuous porous non-hydrated gel polymer material should be used to further enhance safety during the compounding. Is also useful.

  Further, a method of using a hydrogel as at least a part of a pile base material and implanting a pile composed of the above-mentioned composite material or non-hydrogel polymer material into the pile base material is also effective.

  In addition, in order to use the above artificial turf as an alternative to actual natural turf, it is necessary to add an ultraviolet absorber to prevent weathering deterioration when subjected to long-term outdoor exposure, or to green the same as natural turf. It is also useful to apply.

  As described above, according to the present invention, the artificial turf is reduced in the risk of injury due to the generation of frictional heat due to falling, has excellent durability, and can easily control the surface state close to natural turf. Obtainable.

  Although embodiment of this invention is shown below, it cannot be overemphasized that the range of this invention is not restrict | limited to these embodiment.

  As an embodiment of the present invention, first, a raw material for forming an initial cross-linked body containing several mole% of a cross-linking agent and a small amount of a polymerization initiator, for example, an aqueous solution of acrylamidomethyl sulfonic acid is thinly and uniformly formed on a glass substrate. After coating and completely replacing the whole in an inert gas atmosphere, oxygen in the aqueous solution is completely removed, and after the atmosphere is set to a relative humidity of 100%, ultraviolet rays are uniformly irradiated to synthesize the first crosslinked body.

  Then, in an inert atmosphere, the first cross-linked product is immersed in a raw material for forming a second cross-linked product containing a small amount of a cross-linking agent and a polymerization initiator, for example, an acrylamide aqueous solution, or the latter is sprayed on the former. Infiltrate and allow the system to reach an equilibrium state in an atmosphere of 100% relative humidity as described above, and then irradiate ultraviolet rays to synthesize a second crosslinked body, and synthesize a gel having a double crosslinked structure. .

  As a raw material for forming the first crosslinked body, an acrylamide or methacrylamide polymer of an organic acid of any one of carboxylic acid, sulfonic acid and phosphoric acid containing an alkyl group having 2 to 10 carbon atoms is desirable.

  Moreover, as a raw material which forms said 2nd crosslinked body, the acrylamide or methacrylamide polymer which does not contain any organic acids, such as carboxylic acid, a sulfonic acid, and phosphoric acid, is desirable.

  In order to bring the feel of the hydrogel used for the pile closer to natural turf, methods of bringing its own physical properties closer to natural turf and compounding with other polymer material molded products can be considered. The resulting hydrogel is combined with one or more non-hydrogel polymer materials selected from the group of non-hydrogel polymers consisting of polyamide, polyester, polyurethane, polyolefin, polyvinyl chloride, and vinyl alcohol. It is also possible and useful.

  For these composites, it is not always desirable that the hydrogel and the non-hydrogel polymer material are chemically bonded, considering that the dimensions change depending on the amount of water contained in the hydrogel. It is desirable that they are physically encased, or the former and the latter are sandwiched and laminated.

  These non-hydrated gel polymer materials adjust the surface friction coefficient, surface energy, thermal conductivity, etc. in order to bring the surface properties of the pile as close to natural grass as possible, and also include hydrogels inside or between them as required. From the above, it may have minute continuous holes so that moderate moisture oozes on the surface.

  The method of planting the pile on the pile base material is not particularly limited, and the method used for ordinary artificial turf and the method used for carpet is a hydrogel or a polymer material combined with it. It is appropriately selected depending on the characteristics of the turf or the use of the artificial turf.

  Further, as another embodiment, the hydrogel is used as at least a part of a pile base material such as an upper layer, and the above composite material or non-hydrogel polymer material is appropriately formed in a string shape, a thread shape, or a thin tape shape. When a strong surface stress is applied to the pile base material due to a fall of the athlete by the method of forming the pile and planting (piling) on the pile base material, moisture from the water-containing gel constituting the pile base material Leaching or exposing the water-containing gel, it is possible to increase safety and is useful.

  In addition, artificial turf is used outdoors or is exposed to the light of a fluorescent lamp indoors. It is possible and desirable.

  Furthermore, when actually using artificial turf, as an embodiment of the present invention, by providing a pile containing water-containing gel, a pile base material on which the pile is implanted, or a mechanism for supplying water from thereunder. It is also possible and useful to keep the water-containing gel as constant as possible.

  Needless to say, the physical properties of the surface of the hydrogel used in the artificial turf of the present invention, such as the friction coefficient, elastic modulus, and elongation, can also be achieved by controlling the structure of the crosslinked polymer constituting the hydrogel.

  Specific examples of the present invention are shown below, but it goes without saying that the scope of the present invention is not limited by these examples.

  A thickness of 0.3 mm deep and 3 mm wide grooves formed on a smooth and flat aluminum substrate in parallel with almost no gap, and subjected to double-sided hydrophilic treatment as a non-hydrogel polymer material on the aluminum substrate After a 0.1 mm polypropylene film was adhered and the aluminum substrate was coated, 4 mol% N, N′methylenebisacrylamide (MBAA: crosslinker) and 4 mol% were coated on the polypropylene film by the method of Jian Ping Gong et al. A 1M 2-acrylamido-2-methylpropanesulfonic acid (PAMPS) aqueous solution containing 0.1 mol% of 2-oxoglutaric acid (polymerization initiator) was cast and substantially reduced in pressure and nitrogen gas substitution. The first cross-linked product is synthesized by uniformly irradiating with ultraviolet rays at a relative humidity of 100%.

  Then, the first cross-linked product was immersed in a 2M acrylamide (AAm) aqueous solution containing 0.1 mol% MBAA and 0.1 mol% 2-oxoglutaric acid together with the aluminum substrate and the polypropylene film to reach equilibrium. After the caking, the excess AAm aqueous solution other than the aqueous solution impregnated in the gel is removed, and then the first crosslinked body is prepared on the polypropylene film and the first crosslinked body on the aluminum substrate immersed in the AAm aqueous solution. Similarly, a double cross-linked structure is synthesized by uniformly irradiating ultraviolet rays under an inert atmosphere / 100% relative humidity.

  The resulting gel having a double-crosslinked structure exhibits very excellent mechanical properties such as a tensile breaking strength of 10 Mpa, a breaking elongation of 60%, a compression breaking stress of 8 Mpa, and a compression breaking uniaxial deformation of 80%, and an equilibrium water content of 85 The drying rate in an open environment at 25 ° C. and a relative humidity of 40% was 20% of the moisture content per hour for the first time.

  The resulting gel having a double-crosslinked structure was coated with a polypropylene film having both the same thickness of 0.1 mm as described above in contact with a double-sided hydrophilized polypropylene film, and then formed into grooves for forming the aluminum substrate groove. Polypropylene films are melt-bonded to each other and cut at that part, and as shown in FIG. 1 (a), polypropylene film 1a (thickness 0.1 mm) / hydrated gel 1b (thickness 0.3 mm) / polypropylene film 1c A composite tape 1 having a three-layer structure (thickness 0.1 mm) and a width of 3 mm is obtained.

  As shown in FIG. 1B, a pile 1 made of the obtained composite tape 1 (indicated by the same reference numeral as the composite tape 1 for convenience of explanation) is placed on a urethane mat 2 as a pile base material for artificial turf. The piles are piled at 1 mm intervals (piling) so that the pile length is 1 cm, and the lower surface of the urethane mat 2 is joined to the bottom base material (base portion) 3 to form the artificial turf 4.

  The obtained artificial turf 3 of Example 1 was pressed with a 50 mm diameter hemispherical exothermic measurement probe made of 1 mm thick steel material embedded with a thermocouple, and the excess weight was changed from 50 kg to 200 kg. No change in temperature was observed even when sweeping was changed from 0.5 m to 2 m and the sweep speed was changed from 5 m / sec to 20 m / sec.

  In addition, even when the artificial grass 3 of Example 1 above was attached to a room runner and a 70 kg weight monitor wearing soccer shoes conducted a 20-minute running test, some piles 1 were severely cut or damaged. No damage was seen.

  Further, even when the tennis ball was rolled for 1 minute on the artificial turf 3 of Example 1 above, no remarkable change was observed in the appearance, feel and weight due to moisture.

  The composite tape 1 before planting had a weight loss of 2% after the first hour in an open environment at 25 ° C. and a relative humidity of 40%.

  Polypropylene films 1a and 1c sandwiching a hydrogel 1b having a double cross-linking structure prepared in the same manner as in Example 1 in a sandwich shape are spaced at 5 mm intervals instead of heat fusion at the crests on both sides of a 3 mm wide groove. After the point pressure bonding, the laminate of the hydrogel 1b between the polypropylene films 1a and 1c is cut into a tape having a width of 3 mm to form a composite tape 1, and after the composite tape 1 is implanted in the urethane mat 2, After one or both of the polypropylene films 1a and 1c of the composite tape 1 below the urethane mat 2 are cut in the tape major axis direction so that the water-containing gel 1b is easily supplied with water, the lower surface of the urethane mat 2 is supplied with water supply means. The artificial turf 6 is formed by joining the water supply base material 5 having good water permeability and joining the bottom surface of the water supply base material 5 to the bottom base material (base part) 3 to form a water-containing gel. b has a form such that it can maintain a constant moisture content.

  The artificial turf 6 of Example 2 was left in an open atmosphere at a temperature of 30 ° C. and a relative humidity of 30% for 5 hours, and the change in the weight of the composite tape 1 was examined. The change was within the measurement error.

  Although not described in Examples 1 and 2, in the artificial turf of the present invention, the hydrated gel is used as a whole of the pile base material or a part of the surface layer, and the hydrated gel and the non-hydrated gel polymer material. It is possible to plant composite tapes, or to embed a tape or fiber made of a non-hydrogel polymer material with the hydrogel as a whole or a part of the surface of the pile substrate. The shape is not limited to a thin tape shape, but various shapes such as a thread shape, a string shape, and a hollow fiber shape with various cross-sectional shapes, and a shape such as a porous shape on which moisture from an internal hydrous gel is easily leached on the surface It is also good.

  Further, depending on the purpose, it is also possible to use a pile of a hydrated gel alone or a mixed pile of the hydrated gel polymer pile.

  Furthermore, the characteristics of these artificial turf surfaces, such as friction resistance, elasticity, wettability, and durability, include the composition of the hydrogel, the crosslink density, the water content, the selection of the polymer material to be combined, and the pile to be planted. It can be easily and widely controlled by selecting various factors such as dimensions and density and state of planting, the type and structure of the pile substrate to plant the pile, water supply substrate, bottom substrate, UV absorber, etc. .

  The artificial turf of the present invention can be used as an artificial turf suitable for performing a wide range of sports such as soccer, rugby, tennis, hockey, baseball, skiing, both outdoors and indoors. It can be used for various physical and play facilities such as buildings, houses, public squares, and artificial grass, green spaces, and planting basement covering buildings to reduce the recent heat island phenomenon. Can also be used.

(A) is an expanded perspective view which shows the structure of the pile in one Example of the artificial turf of this invention, (b) is sectional drawing which shows the structure of the artificial turf of the said Example using the pile. It is sectional drawing which shows the structure of another Example of the artificial grass of this invention.

Explanation of symbols

1 Pile (composite tape)
2 Urethane mat (pile base material)
3 Bottom base material (basic part)
4 Artificial turf 5 of Example 1 Water supply base 6 Artificial turf pile insertion part of Example 2

Claims (6)

Comprising a pile and a pile substrate on which the pile is implanted,
At least one of the pile and the pile base material has a tensile breaking strength of 0.3 MPa or more, a breaking elongation of 20% or more, a compression breaking stress of 5 MPa or more, a compression breaking uniaxial deformation of 50% or more, and a moisture content of 30% to 100% by weight. An artificial turf comprising a hydrogel having a drying rate in an open environment of 25% relative humidity of 10% or more and 50% or less of the hydrous weight per hour. Comprising a pile and a pile substrate on which the pile is implanted,
At least one of the pile and the pile base material includes a hydrogel,
The hydrogel is a crosslinked structure composed of an acrylamide or methacrylamide polymer of an organic acid of carboxylic acid, sulfonic acid and phosphoric acid containing an alkyl group having 2 to 10 carbon atoms, carboxylic acid, sulfonic acid and An artificial turf having a double cross-linked structure with a cross-linked structure made of acrylamide or methacrylamide-based polymer that does not contain any phosphoric acid.   The hydrated gel is composited with at least one non-hydrated gel polymer material selected from the group of polymer materials consisting of polyamide, polyester, polyurethane, polyolefin, polyvinyl chloride and vinyl alcohol. The artificial turf according to claim 1 or 2.   The artificial turf according to claim 3, wherein the non-hydrated gel polymer material includes the hydrated gel enclosed therein or is laminated with the hydrated gel sandwiched therebetween.   The artificial turf according to any one of claims 1 to 4, further comprising an ultraviolet absorber.   The artificial turf according to any one of claims 1 to 5, further comprising water supply means under the pile base material.

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