JP2001151980A - Gel composition - Google Patents

Abstract

(57) [Problem] It is an object of the present invention to provide a gel composition exhibiting appropriate retardation elasticity and having good adaptability to the body. A gel composition comprising a high molecular weight triblock styrene elastomer having a number average molecular weight of 130,000 or more, a low molecular weight triblock styrene elastomer having a number average molecular weight of 100,000 or less, and a softener is provided. provide. In the gel composition, the high molecular weight triblock styrenic elastomer absorbs and retains a large amount of a softening agent to secure flexibility, and the low molecular weight triblock styrenic elastomer provides delayed elasticity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a gel composition exhibiting delayed elasticity.

[0002]

2. Description of the Related Art Conventionally, a polyurethane foam has been mainly used as a cushion for a bed or a chair. However, the polyurethane foam has a behavior close to a completely elastic body and is not easily adapted to a body, and is used as a cushion for a bed. There is a problem in that when used, bedsores are likely to occur, and when used as a cushion for a chair, the feeling of use deteriorates. Therefore, it has been proposed to impregnate the polyurethane foam with an adhesive, or to make the polyurethane foam material itself sticky to impart adhesion.

[0003]

However, impregnating a polyurethane foam with an adhesive is very troublesome,
And it is difficult to adjust the delay elasticity, and if the polyurethane foam material itself is sticky, special materials are required for materials such as polyvalent isone anat and polyol, and the material becomes expensive, and There is a problem that the delay elasticity cannot be freely adjusted.

[0004]

According to the present invention, as a means for solving the above-mentioned conventional problems, a number average molecular weight of 130,0 is used.
The present invention provides a gel composition comprising a high molecular weight triblock styrene elastomer having a molecular weight of at least 00, a low molecular weight triblock styrene elastomer having a number average molecular weight of 100,000 or less, and a softener. is there. It is desirable that an antioxidant be further added to the composition, and that the antioxidant be a pentaerythritol type phosphite.

[0005]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in detail below.
The styrene elastomer used in the present invention includes, for example, styrene-isoprene rubber (SIR), styrene-ethylene copolymer, poly (α-methylstyrene) -polybutadiene-poly (α-methylstyrene) copolymer (α-Me
(SB-α-MeS), poly (α-methylstyrene) -polyisoprene-poly (α-methylstyrene), butadiene-styrene copolymer (BS), styrene-chloroprene copolymer (SCR), styrene-butadiene -Styrene copolymer (SBS), styrene-isoprene-styrene copolymer (SIS), styrene-hydrogenated polyolefin-styrene copolymer (SEBS), styrene-ethylene-propylene-styrene copolymer (SEPS), butadiene Styrene block copolymer, styrene-rubber intermediate block-styrene copolymer, epoxy-containing styrene-butadiene-styrene copolymer, maleic acid-modified styrene-hydrogenated polyolefin-styrene copolymer (SEBS), and the like. Styrene-based elastomer is amorphous styrene at both ends It is a triblock having a lock.

In the present invention, the triblock elastomer is used in combination with a high molecular weight having a number average molecular weight of 130,000 or more and a low molecular weight having a number average molecular weight of 100,000 or less. The weight ratio with the elastomer is 30:70 to 80:20,
Desirably, the ratio is 35:65 to 65:35.

In the present invention, a softening agent is further added. As the softening agent, for example, an aromatic type, a naphthene type,
Mineral oils such as paraffin, castor oil, cottonseed oil, linseed oil, rapeseed oil, soybean oil, palm oil, coconut oil, peanut oil, wood wax, pine oil, olive oil, and other vegetable oils, dibutyl phthalate, dioctyl phthalate, tricresyl A plasticizer such as phosphate is used. The amount of the softener is usually 3 to 100 parts by weight of the elastomer mixture.
It is about 00 to 2000 parts by weight.

Other than the above composition, the present invention further comprises calcium carbonate, magnesium carbonate, barium sulfate, calcium sulfate, calcium sulfite, calcium phosphate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, magnesium oxide, titanium oxide, iron oxide, Zinc oxide, alumina, silica, diatomaceous earth, dolomite, gypsum, talc, clay, asbestos, mica, glass fiber, calcium silicate, bentonite, white carbon, carbon black, iron powder, aluminum powder, stone powder, blast furnace slag, fry Ash, cement, inorganic fillers such as zirconia powder,
Natural fibers such as cotton, hemp, wool, etc., organic synthetic fibers such as polyamide fiber, polyester fiber, acrylic fiber, viscose fiber, acetate fiber, vinyl chloride fiber, vinylidene chloride fiber, asbestos fiber, glass fiber, carbon fiber, ceramic fiber , Metal fibers, inorganic fibers such as whiskers, organic fillers such as linter, linen, sisal, wood flour, rosin derivatives, petroleum resins or hydrogenated petroleum resins, tackifiers such as cumarone resins, lubricants such as paraffin wax, etc. A third component may be added.

The composition of the present invention contains the above softener in an amount of usually 130
The mixture is heated to a temperature of about 220 ° C., charged with the above elastomer mixture, and stirred for about 1 hour to produce. In such a process, the softener is oxidatively decomposed to generate odorous low-boiling components. Therefore, in the present invention, it is desirable to add an antioxidant in order to prevent oxidation of the softener during the production of the composition. As the antioxidant, an aromatic amine derivative, a phenol derivative or the like is used, and a preferable antioxidant is pentaerythritol type phosphite. The antioxidant is usually added in an amount of 1 to 8 parts by weight based on 100 parts by weight of the elastomer mixture.

[0010]

The high molecular weight triblock type styrene elastomer absorbs and retains a large amount of a softening agent to secure the flexibility of the composition. However, since the retardation elasticity is not remarkably exhibited only with a high molecular weight compound, a low molecular weight compound is added to impart the retardation elasticity. The retardation elasticity can be freely adjusted by a mixing ratio of a high molecular weight compound and a low molecular weight compound. The addition of an antioxidant can prevent the generation of odor components due to the decomposition of the softener by heating, so that a composition having almost no odor can be obtained.

Example 1 Number average molecular weight 180,000
50 parts by weight of high molecular weight triblock SEBS, low molecular weight triblock SEBS having a number average molecular weight of 50,000
50 parts by weight, and 5 parts by weight of pentaerythritol-type phosphite as an antioxidant are added to 1000 parts by weight of a paraffin-based process oil heated to 160 ° C., stirred for 1 hour to swell, and then cooled to remove most of the odor. A poor gel-like composition was obtained. A sample having a thickness of 50 mm was prepared from the gel composition, and a load was applied to the sample so that the sample was compressed and deformed by 50%. In this state, the sample was fixed for 1 minute. With the restored thickness being x, the deformation recovery speed V was determined from the following equation. V (%) = {(2 × −50 mm) / 50 mm} × 100 As a result, V = 76%.

Comparative Example 1 In Example 1, only 100 parts by weight of a high molecular weight triblock type SEBS was used.
Omit the low molecular weight SEBS and antioxidants. The obtained gel composition had an odor, and when the gel composition was measured for deformation recovery rate, V = 92%,
It was recognized that deformation recovery was faster than that of Example 1.

Example 2 Number average molecular weight 260,000
40 parts by weight of high molecular weight triblock type SEPS and low molecular weight triblock type SEBS having a number average molecular weight of 50,000
Naphthenic mineral oil 100 obtained by heating 60 parts by weight and further 5 parts by weight of pentaerythritol type phosphite to 160 ° C.
The mixture was poured into 0 parts by weight, stirred for 1 hour to swell, and then cooled to obtain a gel composition having almost no odor. The same test as in Example 1 was performed on the composition, and the deformation recovery rate was measured. As a result, V = 36%.

Comparative Example 2 In Example 2, only 100 parts by weight of a high molecular weight triblock SEPS was used,
Omit the low molecular weight SEBS. Although the obtained gel composition had almost no odor, the deformation recovery speed V was 74%, and it was confirmed that the deformation recovery speed was faster than that of Example 2.

[0015]

Industrial Applicability The gel composition of the present invention exhibits an appropriate retardation elasticity and has good adaptability to the body, so that it is useful for cushions such as beds and chairs.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tomoko Onozuka 74 Aron Kasei Co., Ltd., 1-Funami-cho, Minato-ku, Nagoya City, Aichi F-term (reference) FD026 FD077 FD170 GC00

Claims (3)

[Claims] 1. A high molecular weight triblock styrene elastomer having a number average molecular weight of 130,000 or more, a low molecular weight triblock styrene elastomer having a number average molecular weight of 100,000 or less, and a softening agent. Gel composition 2. A gel composition characterized by further adding an antioxidant to the composition according to claim 1. 3. The gel composition according to claim 2, wherein the antioxidant is a pentaerythritol type phosphite.