JPH0536901Y2 - - 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 part of the tatami floor made of foamed resin instead of straw to reduce weight and prevent corrosion due to moisture. An example of this type of tatami is the ``tatami floor'' shown in Japanese Utility Model Publication No. 136031/1983, and its structure consists of, from the bottom, synthetic resin sheets, komo, old mats, foamed plastic boards,
It is made by laminating fiber boards, cushion sheets, and synthetic resin sheets such as polypropylene in this order.

However, the structure described above has a large number of constituent members, which makes the structure complicated, and the top surface of the tatami floor, that is, the back surface of the tatami mat, has a synthetic resin sheet such as polypropylene, which makes the tatami The surface layer becomes hard, leading to a decrease in shock absorption ability. Therefore, when the above-mentioned tatami mats are used, for example, in a judo hall, they have the disadvantage that they give a painful feeling to the competitors, making it impossible to compete safely.

In addition to the above, tatami mats with improved shock absorption capacity have been proposed with consideration for use in judo halls.
There is one disclosed in Publication No. 155858. Its structure consists of a stress dispersion layer made of polyolefin-based low foam, etc., and a rubber-based, urethane foam, or polyethylene on a lower synthetic resin foam made of polyolefin-based urethane foam or polyethylene-polystyrene copolymer foam. The upper synthetic resin foam and the covering material are laminated in this order.

However, in such a structure, the structure of the tatami as a whole is too soft due to the presence of a stress dispersion layer made of polyolefin-based low foam between the lower synthetic resin foam and the upper synthetic resin foam. Moreover, not only is it not possible to obtain sufficient strength, but also the above-mentioned polyolefin-based low-foamed material is soft, so it has the disadvantage that a sufficient stress dispersion effect cannot be obtained. In other words, tatami as a flooring material,
Generally, it is formed to a roughly fixed thickness, but the thickness of the lower synthetic resin foam that is the core material is limited by the presence of a stress dispersion layer made of low foam, etc. Can't get strength.

Further, the stress dispersion layer made of a polyolefin-based low-foamed material or the like is itself 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. I can't let it happen,
It is extremely inappropriate for use in a judo hall.

Therefore, as a tatami mat for judo halls that solves these problems, Japanese Utility Model Application No. 61-87829 proposes a core made of a polymer foam made of polyethylene foam beads or a polyethylene-polystyrene copolymer foam. A structure is disclosed in which a plywood board and a polyethylene foam layer for stress dispersion are provided on the upper surface of the core material, and a soft foam member layer with excellent elasticity is provided on the lower surface of the core material.

On the other hand, Utility Model Application Publication No. 49-13504 discloses that polyethylene, polypropylene, or a combination thereof is used as a stress dispersion layer between a core material made of a synthetic resin material such as polyethylene or polystyrene, and a buffer material above the core material. By providing a plastic molded body made of a polymer or a mixture thereof mixed with an inorganic filler, and also providing a plastic molded body made of the same material as the stress dispersion layer on the lower surface of the core material. , a tatami mat with a structure that supplements the strength of the core material is disclosed.

In addition, Japanese Patent Publication No. 54-4180 discloses a tatami with a structure in which the core material is made of compressed hard urethane foam with some of the bubbles destroyed, a lining is provided on the bottom side of the core material, and a tatami face is provided on the top side. has been done.

[The problem that the idea aims to solve]

However, in the structure disclosed in the above-mentioned Japanese Utility Model Publication No. 61-87829, only a soft polyethylene foam layer is provided between the hard plywood board serving as the stress dispersion layer and the tatami surface. It has the disadvantage that the player feels intense pain when passively playing.

One possible way to alleviate the pain felt by athletes is to make the soft polyethylene foam layer thicker, but this would make the tatami too soft,
This poses a danger as your legs may get lost. On the other hand, another way to alleviate the pain felt by athletes is to make the plywood that serves as the stress dispersion layer thinner, but in this case, the strength of the plywood cannot be maintained, the stress dispersion ability decreases, and the core This means that the impact force absorption effect of the material will be halved. Also,
In addition, since this structure uses a plywood board as the stress dispersion layer, it has hygroscopicity, which is disadvantageous for tatami mats, and it also has the problem of being weak against impact and easily cracking.

Furthermore, in the structure disclosed in Japanese Utility Model Application Publication No. 49-13504, a hard plastic molded body is used as the stress dispersion layer, which solves the problems of hygroscopicity and strength caused by using the plywood board mentioned above. be done. However, in this case as well, as with the above, only a soft cushioning material is provided on the plastic forming plate, so it has the disadvantage that the player feels intense pain when performing passive moves. . Furthermore, since this structure uses a synthetic resin material such as polyethylene or polystyrene as the core material, it is extremely unsuitable as a tatami mat for judo halls because of its low impact absorption and compression resistance.

In addition, the structure disclosed in Japanese Patent Publication No. 54-4180 has only the above-mentioned urethane foam layer as a layer for absorbing shock, so if dynamic loads are repeatedly applied, Another problem is that it is difficult to restore the tatami to its original state and cannot provide the compression resistance necessary for judo tatami.

Furthermore, in each of the above tatami mats,
All of the tatami mats other than those disclosed in No. 136031 do not use straw for the core material, so they do not have the weight and feel of tatami mats.

Therefore, the present invention has been designed to provide the weight and feel of tatami mats, as well as the impact resistance, shock absorption, and compression resistance necessary for judo hall tatami mats, as well as to significantly alleviate the pain experienced by athletes. The purpose is to provide tatami for public use.

[Means to solve the problem]

In order to solve the above problems, the tatami mat for judo halls of the present invention has a backing sheet on the lower surface of the straw layer that serves as the core material, and a polypropylene plate, a combination of polyethylene and styrene on the upper surface of the straw layer. It is formed by laminating a hard foamed resin layer made of a polymer, a soft foamed resin layer made of crosslinked polyethylene, and a tatami surface in this order, and the hard foamed resin layer is formed by foam-molding expandable polyethylene-styrene copolymer particles. , this polyethylene-styrene copolymer foam is compressed in the thickness direction by a roll or the like within a range of 30% to 70%, preferably within a range of 40% to 60% to partially destroy the cells. It is characterized by being

[Effect]

With the above configuration, the impact applied to the tatami surface is
Part of the stress is absorbed by a soft foam resin layer made of cross-linked polyethylene with high resilience and a hard foam resin layer made of a copolymer of polyethylene and styrene with high shock absorption.
It is well distributed throughout the straw layer by the rigid polypropylene plates. By being absorbed by this straw layer, it is reliably attenuated.

As mentioned above, in this judo tatami, a hard foam resin layer with high shock absorption capacity is provided between the hard polypropylene plate on the core material and the soft foam resin layer provided on the back side of the tatami mat. Therefore, there is no need to make the soft foam resin layer too thick to make the tatami mat too soft, or make the polypropylene board thinner, which reduces the stress dispersion ability and reduces the shock absorption ability of the core material. For example, it is possible to significantly alleviate the pain experienced by competitors during judo.

Furthermore, since the hard foam resin layer also has stress dispersion ability, the stress dispersion ability is further improved, and stress absorption by the straw layer can be made more reliable.

In addition, the above-mentioned hard foam resin layer made of a copolymer of polyethylene and styrene has high shock absorption ability, moderate hardness and tenacity, is resistant to cracking or chipping, and is weather resistant and durable over time. There is also less shrinkage due to In addition, the soft foamed resin layer made of crosslinked polyethylene has appropriate flexibility and high restoring force, making it difficult for the surface of the tatami mat to deform.

Furthermore, since straw is used as the core material,
It has the weight and feel of tatami mats.

〔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 backing sheet 2 is provided on the lower surface of the straw layer 1.
A polypropylene plate 3, a hard foam resin layer 4 made of a copolymer of polyethylene and styrene, a soft foam resin layer 5 made of crosslinked polyethylene, and a tatami surface 6 are laminated in this order on the upper surface of the tatami mat.

The straw layer 1 is made of conventionally used straw, and even when a large impact force is applied to the surface of the tatami mat, it prevents the surrounding tatami mats from shifting or rising due to the impact force spreading. The weight is given to the entire tatami to prevent this, and in this example, it has a thickness of about 40 mm.

The back sheet 2 is made of a needle-punched fiber sheet or the like, and is provided to protect the straw layer 1 from moisture and to prevent damage to the straw layer 1 due to tightening of the sewing thread.

The polypropylene board 3 has a thickness of about 3 mm in this embodiment, and provides appropriate hardness and strength to the tatami mat. This polypropylene plate 3 itself has hardness and tenacity, is resistant to cracking or chipping even when subjected to impact, is weather resistant, and has the characteristics of being less likely to shrink over time. Furthermore, by using the hard polypropylene board 3 and disposing it on the straw layer 1 as described above, it has the function of sufficiently dispersing the impact received from the tatami surface over the entire straw layer 1. It turns out.

In this embodiment, the hard foam resin layer 4 is in the form of a plate with a thickness of 12 mm, and its lower surface is coated with adhesive in order to simplify the assembly work. This hard foam resin layer 4 has polyethylene particles dispersed in suspension,
A styrene monomer containing a polymerization catalyst is added to this, and the foamed polyethylene-styrene copolymer particles obtained by impregnating this with an easily volatile foaming agent are foam-molded. The material is compressed by a roll or the like to a thickness within a range of 30% to 70%, in this example to 50%, and some of the bubbles are destroyed.

The reason why the hard foam resin layer 4 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, resulting in gaps between the tatami mats, making it suitable for use as tatami mats for judo halls. is extremely dangerous to use. In addition, problems such as buckling may 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 4 having the above-mentioned composition structure was used.

In this embodiment, the soft foamed resin layer 5 has a plate shape with a thickness of 6 mm, and adhesive processing is applied to both sides. Although the soft foamed resin layer 5 shrinks over time, it does not pose a problem considering the overall thickness of the tatami mat because it is set to be 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 surface 6 is made of polypropylene material or woven straw grass.

Further, the straw layer 1, the polypropylene plate 3, and the back sheet 2 are sewn by a sewing machine 7...
It is integrated in. This sewing processing section 7...
They are distributed evenly in five locations across the width of the tatami and parallel to the length of the tatami. As described above, the back sheet 2, the straw layer 1, and the polypropylene plate 3 are sewn together, the hard foam resin layer 4 is pasted on the polypropylene plate 3, and the hard foam resin layer 4 and the soft foam resin layer 5 and the tatami surface 6 are adhered by a soft foamed resin layer 5 which is adhesive-treated on both sides, so that each member is integrated, thereby constructing a tatami mat for a judo hall. Further, the tatami side part and the tatami bottom part of the tatami face 6 are adhered with natural rubber, synthetic rubber, synthetic resin, or hot melt type adhesive.

In the above configuration, when an impact is applied to the tatami mat for the judo hall from the tatami facing side 6, this impact force is partially absorbed by the soft foam resin layer 5, and further absorbed by the hard foam resin layer 4. and is transmitted to the polypropylene plate 3. In particular, the hard foamed resin layer 4 made of a copolymer of polyethylene and styrene has a high impact absorption ability, so that the applied impact force is accurately attenuated. Furthermore, since this hard foam resin layer 4 is provided on the hard polypropylene board 3, it can significantly alleviate the pain felt by the athlete due to contact with the hard polypropylene board 3 during, for example, passive play in judo. be able to. Further, since the hard foamed resin layer 4 has a suitable hardness, it has stress dispersion ability and ensures stress absorption by the straw layer 1 as the core material. Furthermore, since the hard foam resin layer 4 has appropriate hardness and stickiness, even when a large impact is applied,
It does not easily crack or chip, is weather resistant, and shrinks little over time. On the other hand, the soft foamed resin layer 5 made of crosslinked polyethylene has appropriate flexibility and high restoring force, making it difficult for the surface of the tatami mat to be deformed.

Furthermore, between the straw layer 1 and the hard foam resin layer 4,
Since the hard polypropylene plate 3 is interposed, the impact applied through the hard foamed resin layer 4 is once received by the polypropylene plate 3, and the stress is dispersed over the entire straw layer 1. Therefore, the impact force applied to the tatami surface is accurately attenuated. Further, the polypropylene board 3 imparts appropriate hardness and strength to the entire tatami mat, and is set to have 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 mat for judo hall, a polypropylene plate 3 is interposed between the straw layer 1 and the hard foam resin layer 4, and the straw layer 1, the polypropylene board 3, the hard foam resin layer 4, and the soft foam resin layer 5 are made up of the straw layer 1, the polypropylene board 3, the hard foam resin layer 4, and the soft foam resin layer 5. By forming a laminate, together with the hardness of the straw layer 1, hard foamed resin layer 4, etc., appropriate hardness is imparted to the entire tatami mat. In addition, the thicker the straw layer 1 that forms the core material, the stronger the tatami.
Tatami mats used as flooring materials must be formed to a substantially constant thickness. Therefore, by providing the thin polypropylene plate 3 with high strength as described above,
By suppressing the thickness of the straw layer 1 to 40 mm as in this embodiment, sufficient strength can be obtained for the tatami as a whole, and the thickness can be maintained at a predetermined value.

In addition, the soft foam resin layer 5 may be partially replaced with straw.
and a hard foam resin layer 4, it has the weight and feel of a tatami mat while being lightweight overall. In addition, the back sheet 2, straw layer 1, and polypropylene plate 3 are sewn together, and the hard foam resin layer 4, soft foam resin layer 5, and tatami facing 6 are attached to this laminate, which prevents misalignment and wrinkles. ,
The surface of the tatami mat is less likely to bulge, 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 straw layer serving as the core material, and on the upper surface of the straw layer, a hard sheet made of a polypropylene plate and a copolymer of polyethylene and styrene is provided. It is formed by laminating a foamed resin layer, a soft foamed resin layer made of crosslinked polyethylene, and a tatami surface in this order, and the hard foamed resin layer is formed by foam-molding expandable polyethylene-styrene copolymer particles,
The styrene copolymer foam is rolled to a thickness within the range of 30% to 70%, preferably 40% to 60%.
This structure is formed by compressing within a range of 1.5% and partially destroying the bubbles.

This has the effect of providing the original weight and feel of tatami mats, as well as the impact resistance, shock absorption and compression resistance necessary for judo hall tatami mats, and in particular can significantly alleviate the pain felt by competitors. .

[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 sheet, 3 is a polypropylene plate, 4 is a hard foam resin layer, 5 is a soft foam resin layer,
6 is the tatami mat.

Claims (1)

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