JPH0536902Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to tatami mats that have traditionally been used as flooring materials in Japan, and in particular to tatami mats suitable for judo halls.

[Conventional technology]

Some conventional tatami mats have a tatami floor made of foamed resin instead of straw to reduce weight and prevent corrosion due to moisture. As this kind of tatami, Jikko 56-
In No. 54276, foamed polystyrene and a noncombustible board or textiles and felt are arranged in this order on the lining, and strips of cardboard are arranged along both sides of the noncombustible member, and on the felt. A rectangular shape sewn with sewing thread so as to be crimped from the upper surface of a cord stretched across the front surface of the cord is disclosed.

Furthermore, in Utility Model Publication No. 57-15315, the core material is a hard styrene resin-extracted foam with numerous ventilation holes, and on the surface thereof, intervening thin plates such as felt boards and felt are provided in this order, while the core material is The above-mentioned members are attached to the back side of the machine by applying a hessyan woven fabric made of polypropylene synthetic fibers to a spread cotton body of plant fibers, or a needle felt formed by needle punching the above-mentioned hessyan woven fabric alone. Disclosed are those that are integrally glued or sewn.

Moreover, in Utility Model Publication No. 54-25854, a polystyrene resin foam is used as a core material, and a polyethylene resin foam sheet, a plywood board, and a polyethylene resin foam sheet are laminated in this order on the top surface of this core material, and the above-mentioned A structure in which a polyethylene resin foam sheet is laminated on the lower surface of a core material is disclosed.

However, since each of the above-mentioned structures uses expanded polystyrene as a core material, when used in a judo hall, the impact absorption ability and strength are insufficient, making them unsuitable for this type of use.

On the other hand, Japanese Utility Model Application Publication No. 155858/1983 proposes a structure with improved shock absorption ability, with consideration given to its use in judo halls. But in this one,
By having a stress dispersion layer made of a polyolefin-based low-foam material between the lower synthetic resin foam and the upper synthetic resin foam, the structure of the tatami as a whole is not too soft and yet has sufficient strength. In addition, since the stress dispersion layer itself is a soft material, it has the disadvantage that a sufficient stress dispersion effect cannot be obtained.

In other words, tatami mats used as flooring materials are generally formed to a roughly fixed thickness, but the thickness of the lower layer synthetic resin foam that is the core material is determined by the stress dispersion layer made of low foam material, etc. limited by its existence and unable to obtain sufficient strength. In addition, the stress dispersion layer made of polyolefin-based low foam etc. itself
It is relatively soft. Therefore, it is not possible to impart appropriate hardness and strength to tatami mats, and
When a strong impact is received from the tatami surface, the stress cannot be sufficiently dispersed throughout the lower synthetic resin foam, making it extremely unsuitable for use in judo halls.

Therefore, as a tatami mat for judo halls that solves the above-mentioned problems, Japanese Utility Model Application Publication No. 61-87829 proposes a tatami mat between the core material made of polyethylene-polystyrene copolymer foam and the polyethylene foam layer above it. discloses a structure in which a plywood board is provided as a stress dispersion layer, and a soft foam member layer with excellent elasticity is provided on the lower surface side of the core material.

In addition, Utility Model Application No. 61-100737 discloses that a rigid or semi-rigid foam made of polyurethane is used as a core material, and an upper fiberboard and a semi-rigid urethane chip molded board are laminated on the upper surface of this core material. A structure in which a lower fiberboard is laminated on the lower surface of the material is disclosed.

On the other hand, as for the structure of other tatami mats,
In this issue, a stress dispersion layer of polyethylene, polypropylene, a copolymer thereof, or a mixture thereof, and an inorganic filler is provided between a core material made of a synthetic resin material such as polyethylene or polystyrene and a cushioning material above it. Disclosed is a plastic molded body made of a mixture of the above-mentioned stress dispersion layer and a plastic molded body made of the same material as the stress distribution layer on the lower surface side of the core material.

In addition, Japanese Patent Publication No. 54-4180 discloses a core material made of compressed hard urethane foam with some of the bubbles destroyed, a lining on the bottom side, and a tatami surface on the top side. .

[The problem that the idea attempts to solve]

However, in the structure disclosed in the above-mentioned Japanese Utility Model Application Publication No. 61-87829, although the impact absorption properties are relatively good due to the use of polyethylene-polystyrene copolymer foam as the core material, the physique of the athlete is Considering today's tatami mats for judo halls, which are becoming larger and larger and require higher shock absorption properties, the above-mentioned core materials are still insufficient in shock absorption properties. Furthermore, the plywood used as the stress dispersion layer has a problem of being weak against impact and easily cracking.

Furthermore, the structure disclosed in Japanese Utility Model Application Publication No. 100737/1983 is a structure in which a rigid or semi-rigid foam made of polyurethane and a semi-rigid urethane chip molded plate are simply laminated with fiberboard interposed therebetween. Therefore, it is not possible to obtain sufficient shock absorption properties.

On the other hand, in the structure disclosed in Utility Model Application Publication No. 49-13504, the above-mentioned plastic molded bodies are provided on both upper and lower surfaces of a core material made of a synthetic resin material such as polyethylene or polystyrene, thereby increasing the overall strength. However, the shock absorption and compression resistance required for tatami mats for judo halls are low. For this reason, it is not possible to provide a function to accurately attenuate the impact applied during, for example, Ukemi in Judo, to reduce pain to the athlete and prevent injury.

In addition, the structure disclosed in Japanese Patent Publication No. 54-4180 has only a urethane foam layer between the tatami surface and the lining, so it can easily withstand repeated dynamic loads. The problem is that it becomes difficult to restore to its original state, and it cannot provide the compression resistance required for judo hall tatami mats.

Therefore, an object of the present invention is to provide a tatami mat for a judo hall that has the necessary impact resistance and compression resistance as a tatami mat for a judo hall, and also has particularly high shock absorbency.

[Means to solve the problem]

In order to solve the above-mentioned problems, the tatami mat for judo halls of the present invention is provided with a backing sheet on the lower surface of the hard foam resin layer made of a copolymer of polyethylene and styrene that forms the core material, and A pressure plate, a urethane chip layer, a polypropylene plate, a soft foam resin layer made of cross-linked polyethylene, and a tatami surface are laminated in this order on the upper surface of the layer, and the hard foam resin layer is made of foamable polyethylene-styrene copolymer. The combined particles are foam-molded, and the polyethylene
Styrene copolymer foam 30% to 70% in thickness direction
It is characterized in that it is formed by compressing it within a range of % and partially destroying the bubbles.

[Effect]

With the above configuration, the impact applied to the tatami surface is
A portion of the stress is absorbed by the soft foam resin layer provided on the back side of the tatami mat, and the stress is sufficiently dispersed throughout the urethane chip layer by the hard polypropylene plate, resulting in the urethane chip layer having a high impact absorption ability. further absorbed. Thereafter, the above-mentioned stress is dispersed throughout the hard foam resin layer by the pressure plate, absorbed by this layer, and reliably attenuated. At this time, the above-mentioned hard foam resin layer is formed by compressing a polyethylene-styrene copolymer foam with good shock absorption properties in the thickness direction and partially bursting the cells, and has even higher shock absorption properties. The above-mentioned stress is reliably attenuated in the hard foam resin layer. Further, the hard foamed resin layer serving as the core material has high impact resistance and compression resistance, and is less deformed due to aging, temperature changes, etc.

Therefore, this tatami mat for judo halls has the impact resistance and compression resistance necessary for tatami mats for judo halls, and
Particularly high shock absorption properties can be provided.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG.

The tatami mat for judo halls according to the present invention is provided with a back sheet 2 on the lower surface of a hard foam resin layer 1 made of a copolymer of polyethylene and styrene forming a core material, and
On the upper surface of the hard foam resin layer 1, a pressure plate 3, a urethane chip layer 4, a polypropylene plate 5, a soft foam resin layer 6 made of crosslinked polyethylene, and a tatami surface 7 are laminated in this order.

The above-mentioned back sheet 2 is made of a needle-punched fiber sheet, etc., and is used to prevent moisture on the underside of the tatami mat.
This is provided to prevent damage to the hard foam resin layer 1 due to being tightened by the sewing thread.

In this embodiment, the hard foam resin layer 1 has a plate shape with a thickness of 45 mm. This hard foam resin layer 1 is made by dispersing polyethylene particles in suspension, adding a styrene monomer containing a polymerization catalyst thereto, polymerizing the monomer in the polyethylene particles, and impregnating this with an easily volatile blowing agent. In this example, the foamable polyethylene-styrene copolymer particles obtained by the above process were foam-molded, and the polyethylene-styrene copolymer foam was rolled to a thickness within the range of 30% to 70% in the thickness direction. It is made by compressing it to 50% and partially destroying the bubbles.

The reason why the hard foam resin layer 1 has the above composition is as follows. That is, the composition structure of polystyrene foam alone is preferable as a core material for ordinary tatami mats because it has a low degree of shrinkage, but it is too hard for tatami mats for judo halls. In addition, with a composition structure made of foamed polyethylene alone, the air bubbles are destroyed during long-term use, causing the thickness to become thinner and deformed, as well as shrinking due to temperature changes, creating gaps between the tatami mats, making it unsuitable for use as tatami mats for judo halls. There is great danger in using this. In addition, problems such as buckling may also occur. Therefore, in order to eliminate the drawbacks of both of the above-mentioned materials and to combine the characteristics of each material, the hard foamed resin layer 1 having the above-mentioned composition structure was used.

The pressure plate 3 is made of plywood such as plywood and has a thickness of 2.8 mm in consideration of pressure resistance and sewing.
I'm using the one from This pressure plate 3 is effective in temporarily absorbing the impact applied through the urethane chip layer 4 and dispersing the stress throughout the hard foam resin layer 1 to increase the impact absorption capacity. Note that even when the pressure plate 3 is constructed of a plywood board or the like, the pressure plate 3 is located below the polypropylene plate 5, and the urethane chip layer 4 and the hard foam resin layer 1 are located below the polypropylene plate 5.
Since it is interposed between the two, hygroscopicity is suppressed as much as possible.

In this embodiment, the urethane chip layer 4 is formed by forming urethane chips into a plate shape with a thickness of 8 mm by pressure molding or the like.

In this embodiment, the polypropylene board 5 has a thickness of 3 mm, giving appropriate hardness and strength to the entire tatami mat. This polypropylene plate 5 itself has hardness and tenacity, and has the characteristics that it does not easily crack or chip even when subjected to impact, is weather resistant, and has little shrinkage over time. Furthermore, by using the hard polypropylene plate 5 and disposing it on the urethane chip layer 4 as described above, it is possible to sufficiently disperse the impact received from the tatami surface over the entire urethane chip layer 4. It will be equipped.

In this embodiment, the soft foam resin layer 6 is formed into a plate shape with a thickness of 6 mm. This soft foam resin layer 6
Although the tatami shrinks over time, it does not pose a problem considering the overall thickness of the tatami because it is set relatively thin. Note that shrinkage of the tatami in the width direction and length direction does not occur due to the sewing process and integration using adhesive, which will be described later. The tatami surface 7 is made of polypropylene material or woven straw grass.

On the other hand, the back sheet 2, the hard foam resin layer 1, the pressure plate 3, the urethane chip layer 4, and the polypropylene plate 5 are integrated by sewing parts 8. The sewing parts 8 are machine-stitched at five locations in the width direction of the tatami mat at approximately equal intervals and parallel to the longitudinal direction of the tatami mat. Further, the soft foam resin layer 6 and the tatami facing 7 are successively adhered onto the polypropylene plate 5 using a natural rubber adhesive, a synthetic rubber adhesive, a synthetic resin adhesive, a hot melt adhesive, or the like. The tatami facing 7 covers the end surface of the tatami floor made of the laminate except for the tatami facing 7, and is folded back and attached to the peripheral edge of the back surface of the back sheet 2.

In the above configuration, the impact applied to the tatami mat for the judo hall from the tatami face 7 side is partially absorbed by the soft foam resin layer 6. Further, the stress is dispersed over the entire urethane chip layer 4 by the hard polypropylene plate 5, and is further absorbed by the urethane chip layer 4, which has a high impact absorption ability. Thereafter, the above stress is dispersed throughout the hard foam resin layer 1 by the pressure plate 3 and absorbed by this layer.
At this time, the above-mentioned hard foam resin layer 1 is formed by compressing a polyethylene-styrene copolymer foam having good shock absorption properties in the thickness direction and partially bursting the cells, thereby achieving even higher shock absorption properties. Therefore, the above-mentioned stress is reliably attenuated in the hard foam resin layer 1.

In addition, the hard foamed resin layer 1 forming the core has appropriate hardness and toughness, so that it is unlikely to crack or break even when a large impact is applied.
Furthermore, it is weather resistant and shrinks little over time, so it does not lose its shape. Therefore, this tatami mat for judo halls has the necessary shock resistance and compression resistance for a tatami mat for judo halls, and is especially capable of absorbing shock.

On the other hand, the soft foamed resin layer 6 made of cross-linked polyethylene has appropriate flexibility and high restoring force, giving the surface of the tatami the feel of a tatami.

In addition, a soft foam resin layer 6 and a urethane chip layer 4
By interposing a thin polypropylene plate 5 between the tatami and the tatami, the tatami mat as a whole has appropriate hardness and strength together with the hardness of the hard foamed resin layer 1 and the like, and is limited to a suitable thickness.

In other words, tatami is not good if it is too hard or too soft. Especially when used in a judo hall, if it is too hard, it may cause excessive pain to the competitors and may not be able to absorb enough impact. and the safety of the athletes cannot be maintained. On the other hand, if it is too soft, your feet will dig into the tatami, making it difficult to use your feet and leading to injuries such as sprains. In this tatami for judo hall, a polypropylene plate 5 is interposed between the soft foam resin layer 6 and the urethane chip layer 4, and the hard foam resin layer 1, the pressure plate 3, the urethane chip layer 4, the polypropylene plate 5 and the soft By constructing a laminate consisting of the foamed resin layer 6, appropriate hardness is imparted to the tatami mat. Further, the thicker the hard foamed resin layer 1 that forms the core material, the stronger the tatami can be, but the tatami used as a flooring material must be formed to have a substantially constant thickness. Therefore, by providing the thin polypropylene plate 5 having high strength as described above, the hard foam resin layer 1
By suppressing the thickness to 45 mm as in this example, it is possible to obtain sufficient strength for the tatami as a whole and maintain the thickness at a predetermined value.

In addition, each of the components that make up the proposed judo hall tatami,
Since the hard foam resin layer 1 and the soft foam resin layer 6 are made of lightweight chemical products, it is lightweight and resistant to corrosion. Furthermore, a back sheet 2, a hard foam resin layer 1, a pressure plate 3, a urethane chip layer 4, and a polypropylene board 5 are sewn together, and a soft foam resin layer 6 and a tatami facing 7 are attached to this laminate to be integrated. Because of this structure, misalignment, wrinkles, bulges, etc. on the tatami surface are less likely to occur, and each member is less likely to be damaged.

[Effect of idea]

As described above, the tatami mat for judo halls of the present invention is provided with a backing sheet on the lower surface of the hard foam resin layer made of a copolymer of polyethylene and styrene forming the core material, and a back sheet on the upper surface of the hard foam resin layer. , a pressure plate, a urethane chip layer, a polypropylene plate, a soft foam resin layer made of cross-linked polyethylene, and a tatami surface are laminated in this order, and the hard foam resin layer is made of foamed polyethylene-styrene copolymer particles. It is formed by molding the polyethylene-styrene copolymer foam and compressing it within a range of 30% to 70% in the thickness direction to partially destroy the cells.

As a result, this tatami mat for judo halls has the effect of being able to have impact resistance and compression resistance necessary for a tatami mat for judo halls, as well as particularly hard shock absorbing properties.

[Brief explanation of the drawing]

FIG. 1 is an explanatory longitudinal cross-sectional view showing one embodiment of the present invention. 1 is a hard foam resin layer, 2 is a back sheet, 3 is a pressure plate, 4 is a urethane chip layer, 5 is a polypropylene plate, 6 is a soft foam resin layer, and 7 is a tatami surface.

Claims (1)

[Scope of utility model registration request] A backing sheet is provided on the lower surface of the hard foamed resin layer made of a copolymer of polyethylene and styrene that forms the core material, and a pressure plate, a urethane chip layer, a polypropylene plate, and a crosslinked polyethylene layer are provided on the upper surface of the hard foamed resin layer. The hard foam resin layer is formed by laminating a soft foam resin layer and a tatami surface in this order, and the hard foam resin layer is formed by foam-molding expandable polyethylene-styrene copolymer particles, and then forming a foam of this polyethylene-styrene copolymer. A tatami mat for a judo hall characterized by being formed by compressing it within a range of 30% to 70% in the thickness direction and partially destroying the air bubbles.