JP2001198995A - Pad cushioning material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pad cushioning material having excellent body pressure dispersibility and a light weight. SOLUTION: A gel-like material 2 obtained by coating a front surface of a gel-like substance 4 having a constitution in which a liquid-like polymer blended with a filler made of at least one type of a hollow polymer and a foamed polymer, a plasticizer and a crosslinker are blended is crosslinked, with an elastomer film 5 and a low repulsion foamed material 3 are laminated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cushioning material used for a chair or mat, and more particularly to a pad cushioning material having a function of dispersing body pressure in various directions.

[0002]

2. Description of the Related Art Conventionally, soft foams such as urethane foam and rubber foam have been used to provide a body pressure dispersing function to cushion materials used for chairs and mats. However, cushion materials using these soft foams alone have been used. Absorbs body pressure only in one direction (pressing direction) and has a low effect of dispersing body pressure, so that the burden on the body of a person who sits for a long time, such as a wheelchair user, is inevitable. Was. Therefore, cushion materials with better body pressure dispersibility can be obtained by using a soft gel material, laminating urethanes with different repulsion rates and polymer types, and combining the gel material with a soft foam. was suggested.

[0003]

However, the cushioning material in which different kinds of urethanes are laminated is superior to the cushioning material of a kind of urethane alone in the pressing direction of body pressure, but due to the properties of urethane, There are problems with pressure dispersibility and temperature sensitivity in multiple directions, and it is not sufficiently satisfactory as a cushion material.

[0004] In addition, the use of a gel material containing water as a plasticizer for the cushioning material has a disadvantage that the water content changes during use. On the other hand, those using a gel-like substance using a non-aqueous liquid as a plasticizer have good flexibility but poor local stress dispersion, and are sufficient for the user to obtain a satisfactory sitting comfort. Because of the need for a large thickness, there is an inconvenience that the weight becomes large and it is not easy to carry. In addition, the gel-like substance using a non-aqueous liquid as a plasticizer has a problem in that, depending on the type, bleeding of the plasticizer onto the surface occurs, and the contact surface is soiled.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to provide a lightweight cushioning material having multidirectional stress dispersion and low resilience so as to reduce the burden on a user's body. With the goal.

[0006]

In order to achieve the above object, the present invention provides a gel-like polymer having both properties of a sol and a gel containing a plasticizer between molecular networks formed by a crosslinking reaction of a liquid polymer. By laminating a substance and a low repulsion foam material as a soft foam, extremely high flexibility, shock / vibration mitigation and stress dispersibility are imparted to the cushioning material, and
Filling the gel material with a polymer hollow body or a polymer foam can reduce the weight. Further, by sticking an elastomer film on the surface of the gel-like substance, it is possible to prevent the gel-like substance from sticking and to promote appropriate stress dispersion.

According to a second aspect of the present invention, a pad cushion material excellent in stress relaxation is provided by using a urethane foam having a rebound resilience of 10% or less as the low rebound foam material.

According to a third aspect of the present invention, as the gel-like substance, a filler made of at least one of a polymer hollow body and a polymer foam, and at least one plasticizer selected from diisodecyl phthalate or diundecyl phthalate are used. And a crosslinking agent having two or more functional groups selected from isocyanate groups, epoxy groups and amino groups at both ends, including at least both ends.
By using a material obtained by crosslinking a liquid polymer having a functional group selected from an OH group, an epoxy group, and an amino group, a pad cushion material having low bleeding properties can be provided.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of a pad / cushion material 1 of the present invention. The pad / cushion material 1 is made of a gel material 4 obtained by crosslinking a liquid polymer in which at least one kind of filler consisting of a polymer hollow body or a polymer foam, a plasticizer, and a crosslinking agent are blended. A gel material 2 covered with an elastomer film 5 and a low repulsion foam material 3 are laminated via an adhesive layer 6.

FIG. 1 shows an embodiment of the present invention. The lamination of the gel material 2 and the low repulsion foam material 3 can be a plurality of laminations, and is not limited to the repetition of this basic layer. Both the uppermost layer and the lowermost layer of the plurality of layers may be formed of the gel material 2 or the low repulsion foam material 3 on the contrary. Further, the laminated surface of the gel material 2 and the low repulsion foam material 3 may be fixed via an adhesive layer 6 such as a double-sided tape or an adhesive as in the embodiment, or may be heat-bonded.

[0011] The low rebound foam refers to a soft foam such as a rubber foam or urethane foam having a rebound resilience of about 20% or less, and a urethane foam having a rebound resilience of 10% or less in order to obtain better body pressure dispersibility. It is preferred that

The liquid polymer to be crosslinked in the present invention has a functional group selected from OH groups, COOH groups, epoxy groups and amino groups at least at the terminal or side chains, and has polybutadiene, polyisoprene, polyether in the main chain. It has a polyol and a polyester polyol. Specifically, a polyoxyalkylene polyol (SB manufactured by Sumitomo Bayer Urethane)
U-Polyol-0265), 1,4 polybutadiene (Idemitsu Petrochemical R-45HT, R-15HT, etc.),
Liquid polyisoprene rubber (KIRARE LIR-403,
410).

The crosslinking agent has two or more functional groups selected from isocyanate groups, epoxy groups, and amino groups, including both terminals. Those having an isocyanate group include 4,4'-diphenylmethane diisocyanate, toluene 2,4'-diisocyanate, hexamethylene didiisocyanate, triphenylmethane triisocyanate, and polyaryl polyisocyanate.

In addition, those having an epoxy group are 1,4
Butanediol diglycidyl ether, neopentyl glycol diglycidyl ether, trimethylolethane triglycidyl ether and the like. Those having an amino group include metaxylenediamine, diethylenetriamine, triethylenetetramine, and diaminophenylmethane. Further, there are acid anhydrides such as 3,3'-4,4'benzophenonetetracarboxylic dianhydride and M-fevirene-bismaleimide.

The amount of the crosslinking agent to be added is 0.4 to 0.8 equivalent to 1 equivalent of the liquid polymer. If it is less than 0.4 equivalent, the crosslinking is insufficient, and the crosslinked material easily flows out due to the tear of the outer skin material. On the other hand, if it exceeds 0.8 equivalents, the crosslinked material is sufficiently crosslinked and hardened, and the stress dispersibility under low stress is deteriorated.

The plasticizer may be a polar plasticizer having good compatibility with the above liquid polymer, and a phthalic acid plasticizer having low bleeding property is preferable. Specifically, it is at least one selected from diisodecyl phthalate (molecular weight: 447) or diundecyl phthalate (molecular weight: 475), and a phthalic acid-based plasticizer having a smaller molecular weight is more likely to bleed out. A phthalic acid-based plasticizer having a large molecular weight has poor compatibility with the gel material, and the gel and the plasticizer are easily separated.

If the plasticizer is added in an amount of 50 to 400 parts by weight or less than 50 parts by weight based on 100 parts by weight of the liquid polymer, the hardness of the gel material becomes so high that sufficient stress dispersibility cannot be obtained. However, when the stress is removed, the deformation recovery is slow. When the amount exceeds 400 parts by weight, the plasticizer cannot be retained in the gel material, and the gel and the plasticizer are easily separated, and the bleeding is more difficult than the outer material. It becomes easy to out.

The hollow polymer body as the filler is as follows:
Polyacrylonitrile, vinylidene chloride, a hollow body made of such copolymers and the like, specifically, these materials as a partition, low boiling point, a hollow body containing hydrocarbons, or to improve workability A material in which a rubber filler such as calcium carbonate or talc is adhered to the surface of the hollow body may be used. The polymer foam is a powder of polyethylene, polypropylene, polyurethane or the like having closed cells. At least one kind of filler for these polymer hollow bodies and polymer foams can be used. Specifically, two or more kinds of fillers having different particle diameters and materials can be used.

The particle diameter of the polymer hollow body or the polymer foam is 2 mm or less, preferably 0.5 mm or less. When the particle size exceeds 2 mm, the polymer hollow body or polymer foam is separated from the liquid polymer, plasticizer, etc., and does not become a homogeneous gel material, and also loses flexibility and has sufficient stress dispersion ability. And vibration,
Cannot exhibit impact relaxation. The volume fraction of the added amount of the polymer hollow body or the polymer foam is 10 to 80%. If the volume fraction is less than 10%, a sufficient weight-reducing effect cannot be obtained, while if it exceeds 80%, the hardness becomes too high, the elongation of the gel material becomes small, and the recovery from deformation also decreases. Therefore, sufficient vibration, shock relaxation and stress dispersibility cannot be exhibited.

Since the filler made of the above-mentioned hollow polymer or foamed polymer is very small in specific gravity and easily scattered, it is difficult to handle it. It may be used as a mixture.

As the catalyst, triethylamine, N,
N, N ′, N′-tetramethylethyldiamine, tetramethylguanidine, triethylenediamine, dimethylaminoethanol, bis (2-dimethylaminoethyl) ether, tris (dimethylaminomethyl) phenol,
Amines such as dimethylaminomethylphenol, or stannas octoate, dibutyltin diacetate, dibrilltin dilaurate, dibriltin carbubutide,
There are organotin compounds such as lead octoate.

The amount of the catalyst to be added is, for example, when the liquid polymer is subjected to a cross-linking reaction with a cross-linking agent having an isocyanate group, based on 100 parts by weight of the liquid polymer.
In the case where the liquid polymer is subjected to a crosslinking reaction with a crosslinking agent having an epoxy group, the catalyst is used in an amount of 10 to 30 parts by weight based on 100 parts by weight of the liquid polymer. Outside this range, crosslinking is insufficient and a gel material is not formed, and the crosslinking reaction is too fast, resulting in a large variation in gel hardness.

In the present invention, in addition to the above additives, for example, a hindered phenol-based antioxidant, for example, a benzophenone-based or benzotriazole-based ultraviolet absorber, for example, a surfactant such as sodium alkyl ester, or Pentachlorophenol, copper-8
-A fungicide such as hydroxyquinoline can be added alone or as a mixture.

As a method for producing the stress-dispersing gel-like substance, a plasticizer and a light stabilizer are added to the above liquid polymer, and then a crosslinking agent and a catalyst are added, followed by uniform mixing with a stirrer. Thereafter, a polymer hollow body, a polymer foam or a filler plasticizer mixture is further added and uniformly mixed, followed by sufficient dehydration. This is poured into a mold in which a skin material made of an elastomeric film is laid, and at 120-80 ° C., 1-120.
After heating and cross-linking for 10 minutes,
Aging time.

The outer shell material made of an elastomer film is used to coat at least the load surface to which stress is applied so as to further prevent oil bleed-out, and a highly stretchable polyester polyurethane film having a thickness of 30 to 200 μm is used. This is preferable because it prevents adhesion of the stress dispersing material and promotes appropriate stress dispersion.
In the case of a polyether polyurethane film, it swells due to the above oil, and causes significant bleed out of the oil on the surface of the skin material.

[0026]

Next, the present invention will be described in more detail with reference to specific examples. Examples and Comparative Examples A urethane film laminated releasably on paper was cut out by setting dimensions, and this was cut into a piece of 395 mm × 395 mm × 15 mm.
Set to a mold with dimensions of Next, of the materials shown in Table 1, the compounds except the polymer hollow body plasticizer mixture were charged into a stirrer and uniformly mixed. After dehydrating the mixture with a reduced pressure dryer at 1 torr or less for 60 minutes, a polymer hollow body plasticizer mixture was added, and the mixture was further mixed with a stirrer, poured into a mold, and heated at 80 ° C. for 60 minutes. After crosslinking, the mixture was aged at 40 ° C. for 24 hours to obtain a gel substance. Subsequently, after applying an adhesive to the back surface of the gel-like substance, the back surface was covered with an elastomer film to prepare a gel material. The gel material thus obtained and the low-repulsion urethane foam material having a size of 395 mm × 395 mm × 10 mm were further laminated with a double-sided adhesive tape to prepare a pad cushion material.

[0027]

[Table 1]

As a comparative example, the same dimensions (395 mm × 395 mm × 25 mm) as those of the laminate of the example were used.
2 samples of low repulsion urethane foam alone and gel material alone were prepared and compared with the examples.

As a method of measuring body pressure dispersion, the samples of Examples and Comparative Examples were placed on a canvas of a wheelchair, and a subject (body weight: about 60 kg) sat, immediately after sitting (within 15 seconds) and after 600 seconds. The pressure distribution (maximum pressure, average pressure) was measured by a three-dimensional body pressure measuring device FSA (VERG). Table 2 shows the results.

[0030]

[Table 2]

From these results, it can be seen that the lamination of the gel material and the low repulsion foam material is superior to the cushion material of the gel material alone or the low repulsion foam material alone in the impact relaxation and body pressure dispersibility. . In addition, there was no bleed-out of oil to the surface of the skin material, and the sensory evaluation of the user was high.

[0032]

As described above, according to the present invention, a gel material having both characteristics of a sol and a gel containing a plasticizer between molecular networks formed by a crosslinking reaction of a liquid polymer, and a low repulsion foam material By laminating a pad, the pad material has higher flexibility, shock / vibration mitigation, and stress dispersibility than the pad / cushion material of the gel material and low repulsion foam material, respectively.
A cushion material can be realized, and the gel material is filled with a polymer hollow body or a polymer foam to reduce the weight.

According to the second aspect of the invention, by using a urethane foam having a rebound resilience of 10% or less as the low rebound foam material, it is possible to obtain much lower rebound and stress dispersibility.

Further, in the third aspect, by specifying a plasticizer, a cross-linking agent, and a liquid polymer constituting the gel-like substance, low bleeding property can be imparted to the cushion material.

[Brief description of the drawings]

FIG. 1 is a sectional view of a pad cushion material of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pad cushion material 2 Gel material 3 Low repulsion foam material 4 Gel substance 5 Elastomer film 6 Adhesive layer

Continued on front page F-term (reference) 4F100 AH02A AH02H AH03A AH03H AK01A AK28 AK29 AK41 AK51D AK54 AL09B AL09C AT00B AT00C BA04 BA07 BA10B BA10D BA13 CA02A CA04A CA23A CB00 DD31B DD31C DJ01K01 J01J01J01 J01J01

Claims (3)

[Claims] 1. A gel material in which a gel material is coated with an envelope of an elastomer film and a low repulsion foam material are laminated, and the gel material is a polymer hollow body or a polymer foam. A pad / cushion material obtained by crosslinking a liquid polymer containing at least one filler, a plasticizer, and a crosslinking agent. 2. The low rebound foam material has a rebound resilience of 1
The pad / cushion material according to claim 1, wherein the urethane foam material is 0% or less. 3. The liquid polymer having a functional group selected from an OH group, a COOH group, an epoxy group, and an amino group at least at a terminal or a side chain thereof, wherein the gel-like substance is a polymer hollow body or a polymer foam. A filler consisting of at least one of
A blend of at least one plasticizer selected from diisodecyl phthalate or diundecyl phthalate, and a crosslinking agent having two or more functional groups selected from isocyanate groups, epoxy groups, and amino groups at both ends. 3. The pad / cushion material according to claim 1, wherein the pad / cushion material is obtained by crosslinking.