JPH0536900Y2 - - 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]

In conventional tatami mats, a portion of the tatami floor is made of foamed resin material instead of straw, retaining the original weight and feel of tatami mats, while reducing weight and preventing corrosion due to moisture. There is. As disclosed in Japanese Utility Model Application No. 61-136031, this type of tatami includes, from the bottom, a synthetic resin sheet, a rice straw layer, a cut straw layer, a foamed plastic board, a fiber board, It is known that a cushion sheet and a synthetic resin sheet such as polypropylene are sequentially laminated.

However, in the above-mentioned structure, since the uppermost surface of the tatami floor, that is, the back surface of the tatami mat, has a synthetic resin sheet such as polypropylene, the surface layer of the tatami becomes too hard, resulting in a decrease in shock absorption ability. Therefore,
When the above-mentioned tatami mats are used in a judo hall, they have the disadvantage that they give a painful feeling to the competitors, making it impossible to compete safely.

Furthermore, Japanese Utility Model Application Publication No. 56-155858 discloses a structure designed to improve shock absorbing power in consideration of use in judo halls. However, with this type of tatami, the structure of the tatami as a whole is too soft and Can't get enough strength. Furthermore, 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 is sufficiently dispersed throughout the lower synthetic resin foam. Therefore, it is extremely unsuitable for use in a judo hall.

Therefore, as a tatami mat for judo halls that solves the above-mentioned problems, Japanese Utility Model Application No. 61-87829 proposes a tatami mat between the core material made of polyethylene-polystyrene copolymer foam and the polyethylene foam layer above it. To,
A structure is disclosed 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.

On the other hand, as for the structure of other tatami mats,
The publication states that polyethylene, polypropylene, a copolymer thereof, or a mixture thereof is filled with an inorganic material as a stress dispersion layer between a core material made of a synthetic resin material such as polyethylene or polystyrene and a cushioning material above it. A plastic molded body made of a mixture of materials is provided, and a plastic molded body made of the same material as the stress dispersion layer is provided 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 lower side, and a tatami surface on the upper side. There is.

[The problem that the idea aims to solve]

However, for tatami mats for use in judo halls, while it is desirable to reduce the weight so that they can be easily carried, they also need to have a certain degree of stability based on their weight, so that they do not move easily or vibrate even when subjected to a large impact, although this is not as strong as the traditional straw tatami mats.
The structure disclosed in 87829 is lightweight, but it is difficult to prevent movement and vibration in the event of a large impact. In addition, the structure in this publication uses polyethylene-polystyrene copolymer foam as the core material, which provides relatively good shock absorption, but the shock absorption is still insufficient for today's judo hall tatami mats, where athletes are getting larger and larger, and higher shock absorption is required. Also, the plywood used as the stress dispersion layer has the problem of being weak against impact and easily cracked.

On the other hand, in the structure disclosed in Japanese 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 judo hall tatami 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.

Furthermore, although the structure disclosed in Japanese Patent Publication No. 54-4180 is lighter in weight,
As in the above case, it is difficult to obtain a function to prevent movement and vibration against large impacts. Furthermore, since the structure of this publication has only a urethane foam layer between the tatami surface and the lining, it is difficult to easily restore the original state when dynamic loads are repeatedly applied. This tatami mat has the problem of not being able to provide the compression resistance required for judo hall tatami mats.

Therefore, the present invention has the impact resistance, shock absorption, and compression resistance necessary for a tatami mat for a judo hall, as well as stability that does not easily move or vibrate even when subjected to a large impact, and a tatami mat. The purpose is to provide tatami mats for judo halls that have the original weight and feel and are lightweight.

[Means to solve the problem]

In order to solve the above problems, the tatami mat for judo halls of the present invention has a waterproof backing paper on the lower surface of the straw layer that serves as the core material, and a copolymer of polyethylene and styrene on the upper surface of the straw layer. It is formed by laminating in this order a lower hard foam resin layer made of a combination, an upper hard foam resin layer, a polypropylene plate, a soft foam resin layer made of cross-linked polyethylene, and a tatami surface, and the lower hard foam resin layer is made of foamed polyethylene. - Formed by foam molding styrene copolymer particles, compressing this polyethylene-styrene copolymer foam within a range of 30% to 70% in the thickness direction and partially destroying the cells, and having a hard The foamed resin layer is characterized in that it is formed by foam-molding expandable polyethylene-styrene copolymer particles.

[Effect]

With the above configuration, the impact applied to the tatami surface is
Part of the stress is absorbed by the soft foam resin layer made of cross-linked polyethylene with high resilience, and the stress is absorbed by the hard polypropylene plate, the upper hard foam resin layer, and the lower hard foam resin layer in turn. The upper hard foam resin layer is made of polyethylene-styrene copolymer foam and has high impact absorption properties, and the polyethylene-styrene copolymer foam is compressed in the thickness direction. It is formed by partially bursting the bubbles, and is sequentially absorbed by the lower hard foam resin layer, which has even higher impact absorption than the upper hard foam resin layer, and finally by the straw layer, ensuring attenuation. .

By using a layer of straw as the core material, this tatami mat for judo halls has the stability of not easily moving or vibrating even when subjected to a large impact, and has the weight and feel of a tatami mat. There is. In addition, by replacing part of the tatami floor with a straw layer to create a lightweight structure, a lower hard foam resin layer, an upper hard foam resin layer, a polypropylene plate, and a soft foam resin layer are placed on top of the straw layer that serves as the core material. Due to its laminated structure, the overall weight is reduced. Furthermore, with such a structure, the tatami mat has the impact resistance, shock absorption properties, and compression resistance necessary for a judo hall tatami, while having the above-mentioned functions.

That is, when attempting to obtain high shock absorption in a structure having a lightweight upper layer on the straw layer as described above, the upper layer has a high stress dispersion function for the straw layer and a limited Due to the thickness of the tatami mat, it is necessary to have a function that sufficiently compensates for the shock absorption that is lacking in the straw layer. Therefore, in this tatami mat for judo halls, a hard polypropylene plate is provided as a stress dispersion layer under the soft foam resin layer, but if this polypropylene plate is made thicker to enhance the stress dispersion function,
When performing Ukemi in Judo, the competitors experience a strong sense of pain. Therefore, below the polypropylene plate, the above-mentioned upper hard foamed resin layer is provided, which has high impact absorption properties and can also have a stress dispersion function. In addition, in order to ensure sufficient shock absorption in the upper layer above the straw layer, the above-mentioned structure, which has even higher shock absorption than the upper hard foam resin layer, is placed between the upper hard foam resin layer and the straw layer. Equipped with a lower hard foam resin layer. In this way, in the tatami mats for this judo hall,
By creating a two-layer structure between the polypropylene board and the straw layer with the above-mentioned upper hard foam resin layer and lower hard foam resin layer, high shock absorption properties can be obtained without causing strong pain to the athletes. It has become a thing. Further, the upper and lower hard foam resin layers made of polyethylene-styrene copolymer foam and the polypropylene plate, which constitute the upper layer on the straw layer, have high impact resistance and compression resistance.

Therefore, this judo hall tatami mat has the shock resistance, shock absorption and compression resistance required for a judo hall tatami mat, is stable enough not to move or vibrate easily even when subjected to a large shock, and has the weight and feel that is characteristic of tatami mats, all while being lightweight.

〔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 has a straw layer 1 as a core material.
A waterproof backing paper 2 is provided on the lower surface of the straw layer 1, and lower and upper hard foam resin layers 3, 4 made of a copolymer of polyethylene and styrene are provided on the upper surface of the straw layer 1.
It has a structure in which 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 straw layer 1 is made of conventionally used straw and has a thickness of about 40 mm in this embodiment. The backing paper 2 is provided to prevent moisture in the straw layer 1 and to prevent damage to the straw layer due to tightening of sewing threads.

The lower rigid foam resin layer 3 is made by dispersing polyethylene particles in suspension, adding a styrene monomer containing a polymerization catalyst to the polyethylene particles, polymerizing the monomer in the polyethylene particles, and impregnating this with an easily volatile foaming agent. The obtained expandable polyethylene-styrene copolymer particles are foam-molded, and the polyethylene-styrene copolymer foam is rolled 30 mm in the thickness direction using a roll or the like.
% to 70%, in this example, it is compressed to 50% and some of the bubbles are destroyed.

In addition, the upper hard foam resin layer 4 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 adding an easily volatile blowing agent to this. It is formed by foam-molding the impregnated expandable polyethylene-styrene copolymer particles.

Since the lower hard foamed resin layer 3 is harder and has greater cushioning properties than the upper hard foamed resin layer 4, an effective impact force attenuation function can be obtained.

The reason why the lower and upper hard foamed resin layers 3 and 4 have the above-mentioned composition structure is as follows. In other words, in the composition structure of polystyrene foam alone,
Although it is preferable as a core material for ordinary tatami mats because of its low degree of shrinkage, 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 the above-mentioned two materials and to combine the characteristics of each material, the lower and upper hard foamed resin layers 3 and 4 having the above-mentioned composition structure were used.
In addition, in this example, the hard foam resin layers 3, 4
Both form a plate shape with a thickness of 6 mm.

The polypropylene board 5 has a thickness of 3 mm in this embodiment, and provides 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 upper hard foam resin layer 4 as described above, the impact received from the tatami surface is sufficiently distributed over the entire upper hard foam resin layer 4. It will have the ability to disperse.

In this embodiment, the soft foam resin layer 6 has a plate shape with a thickness of 6 mm, and adhesive processing is applied to both sides to simplify the assembly work. 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 in the width direction and length direction of the tatami mat does not occur due to integration through sewing and adhesive processing, which will be described later.

The tatami mat 7 is made of polypropylene material or woven straw grass, and has a thickness of about 1 mm in this embodiment.

On the other hand, the lower and upper hard foam resin layers 3 and 4 and the polypropylene plate 5 are sewn by machine stitching, which is divided approximately equally into five locations in the width direction of the tatami mat and parallel to the longitudinal direction of the tatami mat. It is integrated in part 8. The backing paper 2, the straw layer 1, the lower and upper hard foamed resin layers 3 and 4, and the polypropylene plate 5 are integrated with a stitched part 9 near the end. As described above, the backing paper 2, the straw layer 1, the hard foam resin layers 3 and 4, and the polypropylene board 5 are sewn together, and the polypropylene board 5, the soft foam resin layer 6, and the tatami surface 7 are made of a soft material with double-sided adhesive processing. Each member is integrally formed by being adhered by the foamed resin layer 6, thereby constructing a tatami mat for a judo hall. Further, the tatami side part and the tatami bottom part of the tatami facing 7 are adhered with a natural rubber adhesive, a synthetic rubber adhesive, a synthetic resin adhesive, a hot melt type adhesive, or the like.

In the above configuration, the impact applied from the tatami facing 7 is partially absorbed by the soft foam resin layer 6.
Furthermore, the stress is made of a hard polypropylene plate 5, a polyethylene-styrene copolymer foam,
The upper hard foam resin layer 4 has high shock absorption properties, and is formed by compressing a polyethylene-styrene copolymer foam in the thickness direction and partially destroying the cells,
The lower hard foamed resin layer 3, which has higher impact absorption than the upper hard foamed resin layer 4, allows the particles to be properly dispersed throughout each lower layer in sequence. At this time, the above-mentioned stress is sequentially absorbed by the upper hard foamed resin layer 4 and the lower hard foamed resin layer 3, and finally by the straw layer 1 to be reliably attenuated.

By using the straw layer 1 as the core material, this tatami mat for judo halls has stability that does not easily move or vibrate even when subjected to a large impact, and has the weight and feel of a tatami mat. ing. In addition, by having a lightweight structure in which a part of the tatami floor is replaced with the straw layer 1, the lower hard foam resin layer 3, the upper hard foam resin layer 4, the polypropylene plate 5 and By having a structure in which the soft foam resin layers 6 are laminated, the overall weight is reduced.
Furthermore, with such a structure, the tatami mat has the impact resistance, shock absorption properties, and compression resistance necessary for a judo hall tatami, while having the above-mentioned functions.

That is, as described above, when trying to obtain high shock absorption in a structure having a lightweight upper layer on the straw layer 1, the upper layer has a high stress dispersion function for the straw layer 1, Due to the limited thickness of the tatami mat, it is necessary to have a function that fully compensates for the lack of shock absorption in the straw layer 1. Therefore, in this tatami mat for judo halls, a hard polypropylene plate 5 is provided as a stress dispersion layer under the soft foam resin layer 6, but if this polypropylene plate 5 is made thicker to enhance the stress dispersion function, the judo When performing Ukemi, the player will feel a strong sense of pain. Therefore, an upper hard foam resin layer 4 is provided under the polypropylene plate 5, which has high shock absorption properties and can also have a stress dispersion function.
has been established. In addition, in order to ensure sufficient shock absorption in the upper layer above the straw layer, a layer between the upper hard foam resin layer 4 and the straw layer 1 has a shock absorbency higher than that of the upper hard foam resin layer 4. A hard foamed resin layer 3 is provided below. In this way, in this tatami mat for judo halls, the space between the polypropylene board 5 and the straw layer 1 has a two-layer structure of the upper hard foam resin layer 4 and the lower hard foam resin layer 3, making it easier for athletes to It provides high shock absorption without causing any strong pain sensations.

In addition, the lower and upper hard foam resin layers 3 and 4 made of polyethylene-styrene copolymer foam, which constitute the upper layer on the straw layer 1, and the polypropylene plate 5 have high impact resistance and compression resistance. are doing. In particular, the lower and upper hard foam resin layers 3 and 4 have appropriate hardness and tenacity, so even when a large impact is applied, they are difficult to crack or chip, are weather resistant, and do not shrink over time. It does not lose its shape. In addition, the soft foamed resin layer 6 made of crosslinked polyethylene has appropriate flexibility and high restoring force, giving the surface of the tatami the feel of a tatami.

Therefore, this tatami for judo halls has the impact resistance, shock absorption and compression resistance required for tatami mats for judo halls, and is stable enough to not easily move or vibrate even when subjected to a large impact. It also has the weight and feel of tatami mats, while being lightweight.

Furthermore, by interposing a thin polypropylene plate 5 between the upper hard foam resin layer 4 and the soft foam resin layer 6, the tatami mat has appropriate hardness and strength as a whole, and has a suitable thickness. is set to 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 upper hard foam resin layer 4 and the soft foam resin layer 6, and the straw layer 1, the lower and upper hard foam resin layers 3, 4,
By constructing a laminate consisting of the polypropylene plate 5 and the soft foam resin layer 6, together with the hardness of the straw layer 1 and the lower and upper hard foam resin layers 3 and 4,
The entire tatami mat has a moderate hardness. Further, the thicker the straw layer 1 that forms the core material, the stronger the tatami can be, but the tatami used as the flooring material must be formed to have a substantially constant thickness. Therefore, by providing the thin polypropylene plate 5 with high strength as described above, the thickness of the straw layer 1 can be suppressed to 40 mm as in this embodiment, and sufficient strength can be obtained for the tatami as a whole, and the thickness can be maintained at a predetermined value. It can be maintained.

In addition, backing paper 2, straw layer 1, hard foam resin layer 3,
4. Since the polypropylene plate 5 and the soft foam resin layer 6 are sewn together and the tatami mat surface 7 is attached, misalignment, wrinkles, and bulges on the tatami surface are less likely to occur, and each member is less likely to be damaged. ing.

[Effect of idea]

As described above, the tatami mat of the present invention for judo halls has a waterproof backing paper on the bottom surface of the straw layer that serves as the core material, and
A lower hard foam resin layer made of a copolymer of polyethylene and styrene, an upper hard foam resin layer, a polypropylene plate, a soft foam resin layer made of crosslinked polyethylene, and a tatami surface are laminated in this order on the upper surface of the straw layer. The lower hard foam resin layer is formed by foam-molding expandable polyethylene-styrene copolymer particles, and compresses this polyethylene-styrene copolymer foam within a range of 30% to 70% in the thickness direction. The upper hard foamed resin layer is formed by foam-molding expandable polyethylene-styrene copolymer particles.

This provides the impact resistance, shock absorption, and compression resistance necessary for tatami mats for judo halls, as well as stability that does not easily move or vibrate even when subjected to a large impact, as well as the sense of weight inherent to tatami mats. It has the effect of providing a comfortable feel and being lightweight.

[Brief explanation of the drawing]

FIG. 1 is an explanatory longitudinal cross-sectional view showing one embodiment of the present invention. 1 is a straw layer, 2 is a backing paper, 3 and 4 are hard foam resin layers, 5 is a polypropylene board, 6 is a soft foam resin layer, and 7 is a tatami surface.

Claims (1)

[Scope of utility model registration request] A waterproof backing paper is provided on the lower surface of the straw layer serving as a core material, and a lower hard foam resin layer and an upper hard foam resin layer made of a copolymer of polyethylene and styrene are provided on the upper surface of the straw layer, a polypropylene plate, It is formed by laminating a soft foam resin layer made of cross-linked polyethylene and a tatami surface in this order, and the lower hard foam resin layer is formed by foam-molding expandable polyethylene-styrene copolymer particles. The foam is compressed within the range of 30% to 70% in the thickness direction to partially destroy the cells, and the upper hard foam resin layer is formed by foam molding the expandable polyethylene-styrene copolymer particles. Tatami mats for judo halls are characterized by being formed as follows.