JPH09140960A - Cushion material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cushion material which has a good air permeability and prevents a person from becoming hot when he sits on it and which is soft and has an excellent stress dispersibility and is skin-friendly. SOLUTION: Polyurethane foam layers A, B are stacked on both faces of a woven or knitted fabric layer which is 5-40mm in thickness and has an air permeability of 20cc/cm/sec. or above and has a 25% compressive hardness of 5-40kg and these layers are coated with cloth to be formed into a cushion material of a surface hardness of 60 or below.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cushioning material which is hard to get stuffy when worn and has a soft touch and excellent stress dispersibility. More specifically, the present invention provides
For example, cushions for wheelchairs that are used for a long time and that are easily subject to large loads, cushions for pressure ulcer prevention, etc.
The present invention relates to a cushioning material that can be used in fields requiring air permeability, stress dispersibility, and the like.

[0002]

2. Description of the Related Art As a conventional cushion material, a cardboard-like cushion material having a flat surface (Japanese Patent Laid-Open No. 1-3219)
No. 48), a cushion material in which a flat backside ground structure and a mesh or a flat front side ground are connected by a connecting thread (Jikkou 3-4).
No. 2819), a cushion material thickened by using a woven fabric (Japanese Utility Model Publication No. 5-76388), and a cushion material formed by combining short fibers with a low melting point component (JP-A-5-76388). ), The three-dimensional structure cloth has a multi-woven structure, and the cushion material uses a highly shrinkable yarn as a warp (Japanese Patent Laid-Open No. 6-1.
No. 28837) and the like are known. However, when the conventional cushioning materials are worn for a long time, the stress is insufficiently dispersed in any of them, so that blood retention may occur and numbness may occur, and for bedridden people, it may progress and cause bedsores.

[0003] For example, a corrugated plate-like cushion material is not multi-layered, so that it is difficult to obtain thickness. For this reason, when worn, the amount of deformation is small and it is difficult to partially deform according to the shape of the body, especially when hitting a hard part such as a bone part of a human body or a part that travels, stress concentration occurs,
Since the cushioning material is crushed, the moving layer of air is reduced and it easily gets damp.

The cushion material in which the flat backside fabric is connected to the mesh or the flat front side fabric has a small thickness so that stress concentration occurs and the space for ventilation is small, so that the cushioning material tends to get stuffy. There is also a problem that it is difficult to sew a thick material because it increases the number of processes.

[0005] A thick cloth using a knitted fabric is apt to get damp because it is difficult to obtain a ventilation space connected in both the vertical and horizontal directions in terms of structure. Also, in order to make the fabric thick, it is necessary to reduce the mesh size, and the partial space formed for that is small, and even if it hits a hard part, it is difficult to partially deform and stress concentrates easily. There is also a problem.

Since the aggregate of short fibers has a low air permeability at the single yarn fineness and the density of the ordinary constitution, it tends to give a stuffy feeling when worn. Further, since it has a large number of connection points, when it partially supports an object, local deformation is unlikely to occur, and stress concentration occurs without stress dispersion, resulting in an influence such as blood flow obstruction.

The cushion material made of a three-dimensionally structured cloth having a multiple woven structure has excellent ventilation ability when worn and is unlikely to cause a stuffy feeling, but its thickness is technically limited and stress dispersibility is unsatisfactory. Is enough.

[0008]

SUMMARY OF THE INVENTION The object of the present invention is to solve the drawbacks such as stuffiness caused by wearing and stress concentration during wearing, which easily causes pain and obstruction of blood flow, and is excellent in breathability and stress dispersibility. Moreover, it is to provide a cushioning material having a soft surface hardness and being gentle on the skin.

[0009]

The above-mentioned object of the present invention is to have a thickness of 5 to 40 mm and an air permeability of 20 cc / cm ² / sec.
As described above, the cushion material has urethane foam layers A and B laminated on both sides of a woven or knitted layer having a 25% compression hardness of 5 to 40 kg and covered with a side material, and has a surface hardness of 6
It is achieved by a cushion material characterized by being 0 or less.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The cushioning material of the present invention comprises a woven / knitted layer laminated on both sides thereof with urethane foam layers A and B sandwiched therebetween and covered with a cloth (side fabric). The woven and knitted layer used here has a thickness of 5 to 40 mm,
It is preferably 20 to 35 mm. If this thickness is less than 5 mm, the cushioning property is lowered to become coarse and hard, and the air flow during wearing becomes poor, and stuffiness is apt to occur. On the other hand, when it exceeds 50 mm, there is a problem that the depression when worn becomes too large, and the productivity thereof is reduced, which is not practical. The air permeability of the woven and knitted layer is 20.
cc / cm ² / sec or more, preferably 50 to 300 c
It is necessary to set c / cm ² / sec. This air permeability is 2
When it is less than 0 cc / cm ² / sec, a moving layer of humidity cannot be secured when worn, and a high stuffy feeling occurs. If the air permeability becomes too large,
There is a case where the air flow becomes too good and not preferable depending on the application.

The 25% compression hardness of the woven or knitted layer is 5 to 50.
Kg, preferably 15 to 35 Kg. If it is less than 5 kg, it is too soft and a bottoming feeling is likely to occur, and durability (sag resistance) becomes insufficient. On the contrary, when it exceeds 50 kg, it is too hard and the stress dispersion becomes insufficient when worn,
It causes stress concentration.

As the woven / knitted layer having such characteristics,
For example, the three-dimensional multi-woven knitted fabric previously proposed by the present inventors (Japanese Patent Application No. 7-10033 and Japanese Patent Application Laid-Open No. 7-90757),
A three-dimensional Russell knitted fabric proposed in Japanese Utility Model Publication No. 1-136191 can be exemplified. Among them, the former three-dimensional multi-woven knitting structure is composed of a surface layer part and an intermediate layer part, and the intermediate layer part has one layer having a large number of communicating cavities parallel to one direction. Alternatively, it is preferable to use a woven / knitted layer formed by laminating two or more layers.

The three-dimensional multi-woven knitting structure is substantially composed of filament fibers, and for example, polyester fibers, polyamide fibers, aromatic polyamide fibers, etc. are used. Two or more kinds of these fibers can be used in combination, and in that case, it is preferable to use a polyester fiber and a nylon fiber in combination. The filament fiber may be either a monofilament or a multifilament, but the warp fiber constituting the woven structure is particularly preferably a nylon fiber having a good deformation recovery property.

The woven / knitted layer of the present invention has a three-dimensionally multi-woven or knitted structure substantially composed of filament fibers and three-dimensionally organized as described above, and thus has a very high porosity of 90% or more, It is preferably 93% or more, and it is possible to provide an extremely lightweight cushioning material as a whole.

Next, of the urethane foam layers laminated on both sides of the woven or knitted layer, the A layer on the side which comes into contact with the human body during use has a thickness of 5 to 10 mm and an air permeability of 20 cc / cm.
The surface hardness is preferably ² / sec or more and 80 or less. When the thickness is 5 mm or less, the cushioning material functions insufficiently as a surface softening layer, and it becomes difficult to obtain a cushioning material having a surface hardness of 60 or less. On the other hand, when it exceeds 10 mm, the human body is wrapped too much, which causes a feeling of stuffiness. Further, when the air permeability is less than 20 cc / cm ² / sec, it is not possible to secure the movement of humidity when worn, and a high stuffiness is produced.
Further, the surface hardness is preferably 80 or less, and when it exceeds this, the frictional resistance between the cushioning material and the skin becomes large, so that the problem of skin swelling occurs especially for sick people with weak skin. It will be easier.

The urethane foam layer B laminated on the other surface of the woven or knitted layer has a thickness of 15 to 40 mm, especially 20.
It is desirable to be in the range of -30 mm. This thickness is 1
If it is less than 5 mm, the stress dispersion is insufficient and stress concentration is likely to occur, and blood retention, which is an initial phenomenon of pressure ulcer, occurs. On the other hand, when the thickness exceeds 40 mm, the amount of depression is too large, and it becomes difficult to take a comfortable sleeping posture. The 25% compression hardness is 5-40 kg, especially 10-2.
It is preferably 0 kg. When it exceeds 40 Kg, it hardly functions as a stress dispersion layer and stress concentration occurs. On the contrary, when it is less than 5 Kg, it is too soft and a feeling of bottoming occurs.

If the air permeability of the cloth (side material) covering the laminate of the woven / knitted layer and the urethane foam layer is too small, the movement of humidity is hindered and a stuffy feeling is produced.
It is preferably 0 cc / cm ² / sec or more.

The surface hardness of the cushion material as a whole is 60.
It is important that the ratio is below, preferably 55 or below. If the surface hardness exceeds 60, the friction between the cushioning material and the skin becomes large, and the skin becomes liable to burn,
The object of the present invention cannot be achieved. The surface hardness referred to here is a value measured by a method described later using a spring hardness tester (F type) manufactured by Kobunshi Keiki Co., Ltd.

[0019]

EXAMPLES The present invention will be specifically described below with reference to examples. The compression hardness, air permeability, stress distribution, and surface hardness in the examples were measured by the following methods.

<Compression hardness> JISK-6401-5.
Using the compression plate described in 4.2, compression is performed at a speed of 50 mm / min until the load reaches 110 kg (350 g / cm ² ), and then the load is removed at the same speed. This method was repeated twice, and the compression hardness was determined from the compression length-stress curve drawn during the second measurement. 25% compression hardness = (sample thickness x 0.25) mm Load during compression [kg]

<Air Permeability> Using JISL-1079 (Fragile type air permeability tester), air is sucked so that the differential pressure becomes 1/2 inch, and the amount of air flowing per unit area and unit time at that time is measured. expressed.

<Stress Distribution> A tactile sensor GSCAN system (BIG-MAT) manufactured by Nitta Co., Ltd. was used to measure the vicinity of the sacrum in the supine posture. The size of the pressure sensor is 43 cm × 48 cm, and the distance resolution is 10
mm.

<Surface Hardness> The hardness was measured using a spring hardness tester (F type) manufactured by Kobunshi Keiki Co., Ltd. Diameter 2
A 5.2 mm cylindrical push needle is pressed against the sample by the force of the spring to deform it, and based on the "pushing depth" of the push needle when the resistance of the sample and the force of the spring are balanced. The hardness is measured, and the indentation depth (surface hardness) is represented by 0 to 100, and the spring loads of 0 and 100 are 55 g and 455 g, respectively.

Example 1 A urethane foam layer A having a thickness of 7 mm, an air permeability of 80 cc / cm ² / sec and a surface hardness of 56 was used, and 13 mol% of isophthalic acid was copolymerized as a woven or knit layer. Made of polyethylene terephthalate-based copolyester having an intrinsic viscosity of 0.8, a single yarn fiber has a denier of 4 denier, a total fineness of 1000 denier, a strength of 5.5 g / d, a boiling water shrinkage of 50%, and a thermal stress value of 0. High shrinkage yarn of 0.52 g / d and yarn thickness of 270μ
m polyethylene terephthalate monofilament as warp yarn, polyethylene terephthalate monofilament yarn also having a thickness of 270 μm as weft yarn, weaving machine using dobby multicolor multiple beam, then 150 ° C
Fabric heat-treated for 10 minutes (thickness 30 mm, air permeability 96 cc / cm ² / sec, surface hardness 68.3,
A 25% compression hardness of 21.5 Kg) was used. The urethane foam layer B has a thickness of 30 mm and an air permeability of 4
3 cc / cm ² / sec, surface hardness 66.4, 25%
A sheet having a compression hardness of 15 kg was used. As the side cloth, a woven fabric made of polyethylene terephthalate fiber having an air permeability of 50 cc / cm ² / sec was used. The obtained cushioning material was soft to the touch when worn, had less stuffiness during wearing, and was excellent in stress dispersibility. The characteristics of this cushion material are shown in Table 1.

[Example 2] As a woven / knitted layer, polyethylene terephthalate multifilament 25 was formed on the front side ground structure.
0 denier / 48 filaments, polyethylene terephthalate multifilament 500 denier / 96 filaments for the back side ground structure, diameter 0.16 as connecting yarn
A knitted layer (thickness: 30 mm, air permeability: 152 cc / cm ² / se) obtained by a Karlmeier 14G double Russell machine using a 5 mm nylon monofilament yarn.
c, surface hardness 70.8, 25% compression hardness 25.7K
g), and the same urethane foam layers A and B and side fabric as in Example 1 were used. As in Example 1, the obtained cushion material had little stuffiness during wearing, good stress dispersibility, and soft touch. The characteristics of this cushion material are shown in Table 1.

Comparative Example 1 A cushion material was obtained in the same manner as in Example 1 except that the same sheet as that used for the urethane foam layer B was used as the urethane foam A layer in Example 1. The obtained cushioning material had a good stress dispersibility, but the surface was hard, so that the friction with the skin was large and the cushioning material was hard to wear.

[0027]

[Table 1]

[0028]

EFFECTS OF THE INVENTION The cushioning material of the present invention has a urethane foam layer laminated on both sides of the woven or knitted layer so that the cushioning material has a soft touch when worn, excellent stress dispersion, and low stuffiness. Therefore, by making use of these characteristics, it becomes possible to apply to fields such as a cushion for wheelchairs, a cushion for pressure ulcer prevention, a vehicle seat, etc., which are used for a long period of time and where a large load is partially applied.

Claims (4)

[Claims] 1. A thickness of 5 to 40 mm and an air permeability of 20 cc
/ Cm ² / sec or more, 25% compression hardness 5 to 40 kg
Which is a cushion material in which urethane foam layers A and B are laminated on both sides of a woven or knitted layer which is
A cushion material having a surface hardness of 60 or less. 2. The urethane foam layer A has a thickness of 5 to 10.
mm, surface hardness 80 or less, air permeability 20 cc / cm ²
The cushioning material according to claim 1, which is not less than / sec. 3. The urethane foam layer B has a thickness of 15 to 4
The compression hardness of 0 mm and 25% is 5 to 40 kg.
Alternatively, the cushion material according to item 2. 4. The air permeability of the side ground is 20 cc / cm ² / se.
The cushioning material according to any one of claims 1 to 3, which is c or more.