JP5101184B2 - Cushion material - Google Patents

Description

  The present invention relates to a cushion material in which a cushioning member and a supporting member applied to a cushion material, a cushion, a cushion material for a wheelchair, and a cushion material for preventing pressure ulcer related thereto are combined for use in an automobile seat or chair.

  With the arrival of an aging society, walking is becoming difficult and the number of people who need a wheelchair is increasing. In such a case, it is compelled to sit for a long time, and in some cases, pressure ulcers develop in the buttocks. Therefore, in order to avoid the pain caused by pressure ulcers and to live a comfortable life, cushion materials such as chairs and cushions are required not only to have cushioning performance but also to have high quality with the times. As an external factor for the occurrence of pressure ulcer, it can be said that not only body pressure (compressive stress) applied when sitting, but also a displacement force combined with a shearing force in the lateral direction is important. For example, for a person who has a poor sitting posture or who cannot change his / her position himself, the above-described displacement force works while sitting for a long time.

  Examples of the cushion material used for the above-mentioned applications include air cushion materials, cushion materials made of urethane foam, and cushion materials made of gel-like materials, in addition to natural materials such as cotton. The air cushion material has high load dispersion performance (hereinafter sometimes referred to as “stress relaxation”), but has a problem of low body posture retention performance. Moreover, although the cushion material which consists of urethane foam has a certain level of stress relaxation property, the absorption capability of the slip force attracting attention as one of the causes of pressure ulcer generation is low. In particular, the ability to absorb lateral force, which is a major factor in generating a displacement force, is low. On the other hand, as a cushioning material having a body pressure dispersion performance and a dispersion performance of a displacement force generated from a lateral force, from a low resilience urethane foam having a gel structure which is a kind of a flexible polyurethane foam. A cushioning material has been developed. Since the gel has both liquid and solid physical properties, it is easily deformed and has a high ability to absorb a displacement force generated by stress in all directions including the lateral direction.

  As such a foam, for example, a soft polyurethane foam obtained from an active hydrogen component polyether polyol and an organic polyisocyanate, and a foamed structure of urethane gel has been proposed (Patent Document 1, Patent Document). 2). This gel contains a polyol component separately blended as a plasticizer and a liquid component as an unreacted component of an active hydrogen component polyether polyol blended to form a urethane skeleton.

However, the cushion material made of the low-resilience urethane foam has a uniform hardness, so that it is difficult to maintain the posture when seated and tends to be unstable. In particular, a person who is paralyzed with some of the functions of the body, such as inferiority of the lower body, easily loses the sitting posture and places a burden on the body. Therefore, in order to use the cushion material for a long time, it is required that the seating posture is not easily collapsed and is comfortable while maintaining the load dispersibility and the shift force dispersibility described above.
JP 2006-51067 A JP 2006-188629 A

  In view of the above problems, the present invention provides a comfortable cushioning material that maintains a certain performance with respect to the load dispersion performance and the absorption performance of the shifting force, which is attracting attention as one of the causes of pressure sores, while preventing the sitting posture from collapsing. The task is to do.

  As a result of intensive studies on the cushion material, the present inventors have found that the cushion has at least a two-layer structure including a support member having a shape retention property located in the lower portion and a buffer member having stress relaxation properties located in the upper portion. The present invention was completed by finding that the above-mentioned problems can be solved by devising the shape of each member.

That is, this invention consists of the following.
1. A cushioning material having at least a two-layer structure comprising a supporting member located at the lower part and having a shape-retaining property, and a cushioning member located at the upper part and having a stress relaxation property. with coccyx and sitting bone by the deformation of the cushioning member is formed with a recess so as not to contact with the support member, the peripheral wall portion for supporting the hip muscle portions excluding the sacrum and ischial around the recess from the left and right rear is formed Furthermore, two grooves for supporting the left and right thighs are formed , and a protruding part is provided in a lower part between the two grooves , and the upper part of the support member is provided with a cushion material. A cushioning material, wherein the cushioning member is closely laminated so as to flatten the upper surface.
2 . 2. The cushion material according to 1 above, wherein a bottom portion of a recess formed in the support member passes therethrough.
3 . 2. The cushion material according to 1 above, wherein the support member is formed from a plastic foam.
4 . 2. The cushioning material according to 1, wherein the cushioning member is formed of one or more selected from fibers, sponges, soft plastics, plastic foams, and soft rubbers.
5 . 5. The cushion material according to 4 , wherein the buffer member is formed from a low-resilience polyurethane foam.
6 . 2. The cushion material according to 1 above, wherein a displacement force of the upper surface of the cushion material is 10 to 65N.
7 . ^2. The cushion material according to 1, wherein the cushion member has a compression modulus value in the range of 0.1 to 3.5 N / cm ² .

  The cushioning material of the present invention is a cushioning material having at least a two-layer structure comprising a supporting member located at the lower part and having a shape retaining property and a cushioning member located at the upper part and having stress relaxation properties. The member is different in hardness, and is formed by laminating at least two types of members having different hardness. As a result, when seated, the buttocks and thighs come into contact with the upper surface of the cushion material, the protruding part of the bone existing in the body seat is submerged in the buffer member, and the body part close to smooth is supported by the support member This structure supports the thigh and buttocks muscles, protects the areas where there is a high risk of pressure ulcers such as the sciatic bone, coccyx, and sacrum, makes it easy to maintain posture, makes it comfortable, and causes pressure ulcers Long use is possible. In addition, the cushion material of the present invention can provide a thin and light cushion material while maintaining a load distribution performance equivalent to that obtained by using a conventional gel foam or the like as a cushion.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. In the drawings, the same reference numerals indicate the same or corresponding parts. However, these drawings are examples showing the contents of the present invention symbolically, and the present invention is not limited to these.

FIG. 1 is a side view of one aspect of the cushion material of the present invention. In FIG. 1, a indicates the height of the peripheral wall of the grooves (4) and (4 ′), b indicates the height of the protrusion (3), and c indicates the peripheral wall height around the recess (1).
As shown in FIG. 1, the cushion material of the present invention has at least two layers comprising a support member (A) having a shape-retaining property located at the lower portion and a buffer member (B) having a stress relaxation property located at the upper portion. A cushion material having a structure, and one of the harder members having the effect of maintaining the sitting posture is used as the support member (A), and the soft member has the effect of relieving the compressive stress and the displacement force in order to prevent the occurrence of pressure ulcer. One member is a buffer member (B). Here, the support member (A) is located on the lower surface of the cushioning member (B) that contacts the body as a cushioning material, and supports the thigh, the buttocks muscle part, etc. via the cushioning member (B). It can be said that it is a member. On the other hand, it is preferable that the buffer member (B) is a member that can sufficiently exhibit its original function as a cushion while being supported by the support member (A).

  FIG. 2 is a perspective view showing a basic shape of a support member as a constituent member of one aspect of the cushion material of the present invention. In FIG. 2, d is the lateral width of the support member (A), e is the depth of the support member (A), f is the width of the grooves (4) and (4 ′), and g is the groove (4) and (4 ′). , H is the width of the recess (1), and i is the height of the peripheral wall on the back of the recess (1).

  In the support member (A), a recess (1) is formed so as to avoid contact of the coccyx and the sciatica with the support member, and the buttocks muscle part excluding the sacrum and the sciatus is formed around the recess from the left and right back surfaces. A peripheral wall portion (2) for supporting is formed, and two grooves (4) (4 ′) for supporting the left and right thighs when seated on the cushion material are formed. The cushioning material of the present invention is characterized in that a buffer member (B) is laminated on the upper part of a support member (A) as shown in FIG. 2 as shown in FIG.

  In the cushion material of the present invention, as shown in FIG. 1 and FIG. 2, the lower part of the support member between the concave groove (4) and the groove (4 ′) formed in the support member (A). A protrusion (3) may be provided on the.

  The basic shape of the support member in the cushion material of the present invention is that the thigh can be supported from the left and right and the back when seated as shown in FIG. Since the shape (body shape) from the buttocks to the thigh when sitting is different for each individual, if the shape of the support member is not strictly adapted to each individual, sufficient load distribution performance and comfort can be obtained. It's hard to say. Therefore, the cushion material of the present invention can be applied to a wide variety of body shapes by laminating a buffer member (B) made of a material softer than the support member on the support member (A). .

Here, the buffer member (B) is characterized by being softer than the support member (A). Specifically, the hardness of the cushioning member having a function as a cushion (B) is, 0.1~3.5N / cm ² as a compression modulus value, which will be described later, preferably 0.15~2.0N / cm ² It is. When the hardness of the buffer member (B) is less than 0.1 N / cm ² , it is too soft and the buttock sinks too much when seated, and the bone present in the buttock mounts the bottom of the support member and the cushioning material. It tends to come into contact with the seat surface of the chair, making it difficult to exert sufficient effects to prevent the occurrence of pressure ulcers. On the other hand, when the hardness exceeds 3.5 N / cm ² , it tends to be difficult to obtain compressive stress relaxation property and shear stress relaxation property for preventing the occurrence of pressure sores because it becomes too hard. The support member (A) is not particularly limited as long as the support member (A) is harder than the support member (A) and can hold the buffer member (B) on the upper part.

  In addition, the hardness of the said buffer member in this invention is performed according to the measuring method as described in JISK6401 "soft polyurethane for load-bearing." Specifically, a universal testing machine “Autograph AGS-100” (manufactured by Shimadzu Corporation) is used as a measuring device, and a buffer member or a support member having a size of about 38 cm in length × about 38 cm in width × any thickness at room temperature From a top surface of the cushioning member of the composite cushioning material, a metal disk having a diameter of 200 mmφ is pressed at a compression speed of 10 mm / min to a depth of 25% of the entire thickness of the cushioning member or 20 mm, and left for 10 minutes as a time for stress relaxation. The compression modulus value thus obtained was defined as the hardness in the present invention.

The lower surface of the support member (A) constituting the cushion material of the present invention is in contact with a seat surface of a chair or a wheelchair. For example, when the seating surface of a wheelchair is comprised with the material which produces bending, such as cloth and synthetic leather, the shape of a support member (A) becomes easy to change with the bending of a seating surface. That is, when sitting on the cushion material of the present invention, the sitting position is such that the thigh is positioned in the groove (4) and the groove (4 ′) for supporting the thigh formed in the support member (A). Since it is held, if the seating surface of a wheelchair or the like is bent, a load is applied to the groove portion, and the cushion material is bent in a mountain shape, which may break the support member. Accordingly, in order to maintain the shape of the support member (A) even if the seating surface is bent, a protruding portion is provided at a lower portion between the groove (4) and the groove (4 ′) for supporting the thigh. It is preferable to provide (3). Further, as shown in FIG. 2, removing the support member located at the bottom of the formed in the support member recesses, by penetrating, bottoming caused coccyx or sitting bones when seated is in contact with the bottom of the recess The feeling can be eliminated, which is preferable.

3 to 5 are a front view (FIG. 3), a side view (FIG. 4), and a rear view (FIG. 5) of a support member used in one aspect of the cushion material of the present invention. FIG. 6 is a rear view of the support member when the cushion is used on a smooth surface in another aspect of the cushion of the present invention.
In these drawings, the supporting member (A) has the peripheral wall portion (2), the protruding portion (3), and the grooves (4) and (4 ′) formed at predetermined positions. While maintaining the shape and maintaining the sitting position, it is possible to prevent the body from shifting forward when sitting. In particular, by forming the protrusion (3) as shown in FIG. 6, the effect can be remarkably exhibited.

  In the present invention, the material constituting the support member (A) supports the buffer member (B) and is a material harder than the buffer member, preferably a slight deflection, but may be a material with as little deformation as possible. That's fine. Specific examples include soft plastics such as polyethylene and polypropylene, hard plastics such as polystyrene, foams of these plastics, hard rubber, and wood. Among these, it is preferable to use a plastic foam from the viewpoints of weight reduction and moldability, and specific examples include polyethylene foam, polystyrene foam, and polyethylene / polystyrene foam. In addition, the foaming form may be either independent foaming or continuous foaming, but in order to have mechanical strength and shape retention as a support member, the foaming form is preferred.

  In this invention, the material which comprises a buffer member (B) should just be a material which can generally be used for a cushioning material. Specific examples include fibers, sponges, soft plastics, foams of these plastics, and soft rubber. Of these, soft plastic foams, particularly polyurethane foams are preferred as those capable of relieving compressive stress and shear stress and preventing the occurrence of pressure ulcers, especially polyurethane foams generally called low resilience It is better to use the body. In addition, as the foaming form, either independent foaming or continuous foaming may be used. However, in order to exert more stress relaxation as a buffer member, the continuous foaming form (the cell wall of the independent foaming cell is torn into a continuous foaming state). (Including mixed systems such as).

  The polyurethane foam which is a preferable material constituting the above-described buffer member (B) belongs to a class of so-called thermoplastic elastomers obtained by polyaddition reaction of polyisocyanate and polyol. A foam made of polyether polyurethane or the like can be used. Specifically, a polyisocyanate prepolymer obtained by reacting a polyisocyanate such as diphenylmethane diisocyanate or tolylene diisocyanate and a polyol such as ethylene oxide or propylene oxide in an equimolar amount in terms of the number of functional groups is reacted by adding the polyol. Thus, a polyurethane composition having a three-dimensional structure (gel structure) is once produced. Next, by adding water, the unreacted isocyanate group remaining in the polyisocyanate prepolymer reacts with water to generate carbon dioxide and foam, and the isocyanate group changes to an amino group or the like by reaction with water. As a result, this reacts with other isocyanate residues to form urea bonds and the like, and the cross-linked structure proceeds to obtain a polyurethane foam having the target gel structure. At this time, by adding an excessive amount of polyol to the polyisocyanate, the unreacted polyol acts as a plasticizer in the polyurethane foam. In addition, you may mix | blend a low-reactive plasticizer and softener separately.

  In the polyurethane foam having the gel structure described above, the low-reactivity polyol added for the purpose of plasticizer and the unreacted product of the polyol added for forming the urethane structure are incorporated into the polyurethane system as a liquid component. It has a gel structure in the state. As a result, it has the ability to absorb the shear force generated by the lateral force in addition to the relaxation property against the compressive stress that is the original characteristic of the gel, and is an excellent load as a cushioning material made of polyurethane foam. Demonstrate dispersion performance. Moreover, since it is a foam, the weight of the entire cushioning material can be reduced.

  As the polyurethane foam that can be used for the buffer member in the present invention, specifically, those described in Patent Document 1 can be used. For example, the cushioning member in the present invention can be integrated with the support (A) of the present invention to form the cushion material of the present invention, and then enclosed in a bag or the like for use.

  The cushioning material of the present invention can maintain the sitting posture by the support member when seated, has the effect of relaxing the compressive stress by the buffer member, and the effect of relaxing both the shearing force in the lateral direction and the combined displacement force. Have. The displacement force in this case is adjusted to a range of 10 to 65N, preferably 25 to 55N on the upper surface of the cushion material. That is, if the displacement force is less than 10N, the seated person may be given a fluffy feeling when sitting, and it may be difficult to maintain a stable posture. If the displacement force exceeds 65N, When the body is moved in a state, a large force acts on the sitting heel part and tends to develop inflammation such as pressure ulcer.

  The displacement force in the present invention can be measured by the method described in Patent Document 1 (Japanese Patent Laid-Open No. 2006-51067).

  The present invention will be described more specifically with reference to the following examples. However, the present invention is not limited to these examples, and various applications are possible without departing from the technical idea of the present invention.

Example 1
A support member made of a polyethylene / polystyrene foam molded into the shape shown in FIG. 2 was prepared. As the buffer member, one having the following composition was prepared.
50 parts by weight of diphenylmethane diisocyanate and 50 parts by weight of a polyether polyol (polyoxyethyl polyoxypropylated glycol, ethylene oxide / propylene oxide: 75/25% by weight, OH value: 56, molecular weight: 3000) are reacted. Isocyanate prepolymer A (NCO group content: 15 mol%) was prepared.

Also, 5 parts by weight of tolylene diisocyanate and 95 parts by weight of polyol (polyoxyethyl polyoxypropylated glycol, ethylene oxide / propylene oxide: 70/30% by weight, OH number: 7.5, molecular weight: 15000) are reacted. Thus, polyisocyanate prepolymer B (NCO group content: 2 mol%) was produced.
21 parts by weight of the polyisocyanate prepolymer A and 14 parts by weight of the polyisocyanate prepolymer B prepared as described above, and a polyether polyol (polyoxyethyl polyoxypropylated glycol, ethylene oxide / propylene oxide: 50/50) 65 A polyurethane gel composition was prepared by reacting parts by weight, and then 3 parts by weight of water was added at room temperature, stirred, mixed and foamed to prepare a cushioning member made of a polyurethane foam having a gel structure. .

In addition, after the production of the buffer member, in order to be integrated with the support member to form the cushioning material of the present invention, the composition is poured into a mold and aged in a state of being laminated with the support member. A cushion material of the present invention having a thickness of 38 cm and a total thickness of 7 cm was produced. (Displacement force 30N, buffer member portion hardness 0.4N / cm ² )

(Comparative Example 1)
Using only the cushioning member made of the polyurethane foam produced in Example 1, a cushion material having a length of 38 cm, a width of 38 cm, and a thickness of 9 cm without a support member was produced. (Slip force 25N, buffer member hardness 0.3N / cm ² )

(Test example)
Of the following tests, for practicality, the cushion material produced in Example 1 and Comparative Example 1 was enclosed in an interior bag, and then placed in an exterior bag for testing.

  About the cushion material obtained in the said Example 1 and the comparative example 1, the measurement of the maximum contact pressure and the practical test were done. The maximum contact pressure indicates the maximum pressure in the surface contact pressure distribution. Since the maximum contact pressure increases as the surface contact pressure distribution becomes non-uniform, the maximum contact pressure tends to decrease as the load dispersibility is improved. Here, “load dispersibility” is a distribution of a load applied to the boundary between the cushion seat surface and the body when sitting on the cushion material, and is usually expressed in units of mmHg.

  In the present invention, the load dispersibility was measured by laying a seat in which a pressure sensor was incorporated on a cushion material and sitting on the seat. It is determined that the more uniform the surface contact pressure distribution is, the better the load distribution is.

  The practicality was confirmed by listening to the testimony of each subject regarding “slip”, “comfort”, and “stability”. The test subjects were wheelchair users aged 23 to 74 years, with 5 males and 3 females. The evaluation was score evaluation applying the “Pain Numerical Evaluation Scale”. As shown in Table 1, the score is divided into three groups of 0 to 2 points, 3 points, and 4 to 6 points, ranging from 0 to 6 points. “Neither” or “good”.

  The test results are shown in Table 2. The thickness of the cushion material of the present invention in Example 1 was 7 cm, and the load dispersibility was the same in both cases although it was 2 cm thinner than the thickness of 9 cm in Comparative Example 1. In the practical test, the body slippage did not occur in Example 1, whereas in Comparative Example 1, there were two slippers. Clearly, the cushion material of Example 1 was superior in terms of comfort and stability.

As described above in detail, it has been confirmed that the cushioning material by the combination of the support member and the cushioning member of the present invention is superior in maintaining the sitting posture as compared with the cushioning material produced by the cushioning member alone. Further, the comfort can be improved, and the device can be used for a long time.
The cushion material of the present invention can reduce the thickness of the cushion as compared with the case where the cushioning member is used alone, and can realize weight reduction depending on the material used for the support member. Further, even if such lightening is performed, the characteristics of the buffer member such as load dispersibility are not impaired.
Therefore, if the cushion material of this invention is used for a wheelchair or a chair, it can be used as a comfortable cushion material. Moreover, since load dispersibility improves, it can utilize effectively in the field of care.

It is a side view of one mode of the cushion of the present invention. It is a perspective view which shows the basic shape of the supporting member used for the one aspect | mode of the cushion of this invention. It is a front view of the support member used for one mode of the cushion of the present invention. It is a side view of the supporting member used for one mode of the cushion of the present invention. It is a rear view of the support member used for one mode of the cushion of the present invention. It is a rear view of the supporting member in the case of using a cushion with a smooth surface about the other aspect of the cushion of this invention.

Explanation of symbols

A Support member B Buffer member 1 Concave part 2, 2 'Peripheral wall part 3 Protruding part 4, 4' Groove a Groove peripheral wall height b Protrusion part height c Periphery peripheral wall height d Support member lateral width e Support member Depth f Groove width g Groove depth h Recess width i Recess wall depth

Claims (7)

A cushioning material having at least a two-layer structure comprising a supporting member located at the lower part and having a shape-retaining property, and a cushioning member located at the upper part and having a stress relaxation property. with coccyx and sitting bone by the deformation of the cushioning member is formed with a recess so as not to contact with the support member, the peripheral wall portion for supporting the hip muscle portions excluding the sacrum and ischial around the recess from the left and right rear is formed Furthermore, two grooves for supporting the left and right thighs are formed , and a protruding part is provided in a lower part between the two grooves , and the upper part of the support member is provided with a cushion material. A cushioning material, wherein the cushioning member is closely laminated so as to flatten the upper surface. The cushion material according to claim 1, wherein a bottom portion of the concave portion formed in the support member passes therethrough. The cushion material according to claim 1, wherein the support member is formed of a plastic foam. The cushioning material according to claim 1, wherein the cushioning member is formed of one or more selected from fibers, sponges, soft plastics, plastic foams, and soft rubbers. The cushion material according to claim 4 , wherein the cushioning member is formed of a low-resilience polyurethane foam. The cushion material according to claim 1, wherein a displacement force of the upper surface of the cushion material is 10 to 65N. Hardness of the buffer member portion, the cushion material according to claim 1 is a compression modulus values ranging 0.1~3.5N / cm ^2.

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