JPWO2019203284A1 - Rubber composition for artificial limb sole and sole for artificial limb - Google Patents

Abstract

An object of the present invention is to provide a rubber composition for an artificial limb sole, which can improve anti-slip property and abrasion resistance when used for an artificial limb sole. In order to solve the above problems, the present invention has a rubber component containing 50% by mass or more of styrene-butadiene rubber and a nitrogen adsorption specific surface area (N2SA) of 50 to 90 parts by mass with respect to 100 parts by mass of the rubber component. It is characterized by containing carbon black, which is ~ 149 m2 / g.

Description

The present invention relates to a rubber composition for an artificial limb sole and a sole for an artificial limb.

In general, it is desired that the artificial limb can walk and run with peace of mind. Until now, soles for artificial limbs have rarely been specially developed, and those obtained by diverting a part of the soles of commercially available shoes or those obtained by cutting and pasting commercially available rubber sheets have been used.

Further, as one of the artificial limbs for competition, one provided with a leaf spring is known (see, for example, Patent Document 1), but when an artificial limb having a leaf spring is used, the grip of the leaf spring with the road surface is used. Since it has low property, it may slip especially when used in rainy weather, and improvement in anti-slip property has been desired.
As a technique for attaching a sole to an artificial limb for competition, for example, Patent Document 2 discloses a technique for attaching a rubber sole to cover a spike in an artificial limb for competition.
However, it has been desired to develop a technique for improving the grip force of the sole of the artificial limb, not a technique for improving the anti-slip property of the sole of the artificial limb. Further, once the artificial limb is worn, it is often used for a long period of time, and improvement in the wear resistance of the sole has been desired.

Japanese Unexamined Patent Publication No. 2017-35324 Japanese Unexamined Patent Publication No. 2016-150189

Therefore, an object of the present invention is a rubber composition for an artificial limb sole that can improve anti-slip property and abrasion resistance when used for an artificial limb sole, and an artificial limb sole having excellent anti-slip property and abrasion resistance. Is to provide.

As a result of studies to solve the above problems, the present inventors have made a specific amount of styrene-butadiene rubber contained in the rubber component as a component constituting the rubber composition, thereby gripping on a dry road surface and a wet road surface. By increasing the force and containing carbon black having a specific surface area of nitrogen adsorption, the wear resistance of the rubber composition can be increased, so that both anti-slip and wear resistance are at a high level. I found that they are compatible.

The gist of the present invention is as follows.
The rubber composition for a prosthesis sole of the present invention contains a rubber component containing 50% by mass or more of styrene-butadiene rubber and a nitrogen adsorption specific surface area (N ₂ SA) of 50 to 90 parts by mass with respect to 100 parts by mass of the rubber component. It is characterized by containing carbon black, which has a mass of 110 to 149 m ^{2 / g.}
By providing the above configuration, anti-slip property and wear resistance can be improved when used for the sole of an artificial limb.

Further, the rubber composition for a prosthesis sole of the present invention preferably further contains 5 to 40 parts by mass of a thermoplastic resin with respect to 100 parts by mass of the rubber component, and the thermoplastic resin is a petroleum resin or coal. More preferably, it is at least one selected from the group consisting of based resins, phenolic resins, rosin resins and terpene resins. This is because the anti-slip property when used for the sole of an artificial limb can be further enhanced.

Further, in the rubber composition for artificial limb sole of the present invention, it is preferable that the rubber component further contains natural rubber. This is because the wear resistance when used for the sole of an artificial limb can be further improved.

The sole for artificial limbs of the present invention is characterized in that the rubber composition for artificial limbs sole of the present invention is used.
By providing the above configuration, excellent anti-slip property and wear resistance can be realized.

Further, in the artificial limb sole of the present invention, the artificial limb sole is a contact extending from the toe to the curved portion side of a competition artificial limb having a leaf spring-shaped foot portion extending toward the toe side via a curved portion. It has a bottom surface that is mounted on the area and has a pattern consisting of multiple irregularities.
The bottom surface of the artificial limb sole has a boundary line extending in the width direction of the foot portion through the contact point between the bottom surface of the artificial limb sole and the road surface in a state where the wearer wearing the artificial limb is upright. The negative ratio on the curved portion side of the boundary line is preferably 35 to 80%, and the negative ratio on the toe side of the boundary line is preferably 55% or less. This is because both anti-slip property and wear resistance can be achieved at a higher level.

Further, in the artificial limb sole of the present invention, it is preferable that the artificial limb sole is directly or indirectly attached to the leaf spring. This is because the anti-slip property and wear resistance of the present invention can be exhibited more effectively.

According to the present invention, there is provided a rubber composition for an artificial limb sole capable of improving anti-slip property and abrasion resistance when used for an artificial limb sole, and an artificial limb sole having excellent anti-slip property and abrasion resistance. it can.

It is a side view of the artificial limbs for competition which the sole which concerns on one Embodiment of this invention is attached. It is a figure for phasing out the movement of the foot and the ground contact form when the artificial limb for competition is worn and the wearer goes straight. It is a figure for phasing out the movement of the foot and the ground contact form when the artificial limb for competition is worn and the wearer goes straight. It is a figure for phasing out the movement of the foot and the ground contact form when the artificial limb for competition is worn and the wearer goes straight. It is a figure for phasing out the movement of the foot and the ground contact form when the artificial limb for competition is worn and the wearer goes straight. (A) and (b) are views schematically showing the bottom surface of the sole according to the embodiment of the present invention. It is a figure which showed an example of the pattern of the sole bottom surface of the sole for artificial limbs which concerns on one Embodiment of this invention.

Hereinafter, the rubber composition for an artificial limb sole and the embodiment of the sole for an artificial limb of the present invention will be described in detail.

<Rubber composition for artificial limb sole>
The rubber composition for artificial limb sole of the present invention (hereinafter, may be simply referred to as “rubber composition”) contains 50% by mass or more of styrene-butadiene rubber and 50 parts by mass of the rubber component. Includes up to 90 parts by mass of carbon black with a nitrogen adsorption specific surface area (N ₂ SA) of 110 to 149 m ^{2 / g.}
By containing 50% by mass or more of styrene-butadiene rubber in the rubber component as a component constituting the rubber composition, the grip force on a dry road surface and a wet road surface can be improved, and N ₂ SA is 110 to 110 to By containing carbon black in the range of 149 m ² / g, wear resistance can be improved. As a result, when the rubber composition is used for the sole of an artificial limb, both anti-slip property and wear resistance should be improved. Is possible.

(Rubber component)
The rubber composition for artificial limb sole of the present invention contains a rubber component. The rubber component contains 50% by mass or more of styrene-butadiene rubber (SBR).
As described above, by containing 50% by mass or more of styrene-butadiene rubber, when the rubber composition is applied to the sole of the artificial limb, the flexibility of the rubber is improved and the grip of the sole can be enhanced, which is high. Anti-slip property can be realized. When the content of styrene-butadiene rubber in the rubber component is less than 50% by mass, the grip force becomes low, so that sufficient anti-slip properties cannot be obtained.
From the same viewpoint, the content of styrene-butadiene rubber in the rubber component is preferably 60% by mass or more. Further, from the viewpoint of maintaining a high level of grip force, the content of styrene-butadiene rubber in the rubber component is preferably 100% by mass or less.

As the styrene-butadiene rubber, either emulsion polymerization SBR or solution polymerization SBR can be used. Further, a commercially available product can also be used, and can be appropriately selected according to the required performance. Further, the styrene-butadiene rubber may be modified or unmodified.

Further, as the rubber component, in addition to the above-mentioned styrene-butadiene rubber, a rubber other than the styrene-butadiene rubber (hereinafter, referred to as “other rubber component”) can be included depending on the required performance.
The other rubber components are not particularly limited and can be appropriately selected depending on the intended purpose. For example, diene rubbers such as natural rubber (NR), butadiene rubber (BR) isoprene rubber (IR), styrene isoprene butadiene rubber (SIBR), chloroprene rubber (CR), acrylonitrile butadiene rubber (NBR), ethylene propylene diene rubber ( Examples thereof include non-diene rubbers such as EPDM), ethylene propylene rubber (EPM), and butyl rubber (IIR). The other rubber components may be modified or unmodified.

Further, the rubber component preferably further contains natural rubber among the other rubber components described above. This is because better wear resistance can be obtained.
Here, the content of natural rubber in the rubber component is not particularly limited, but from the viewpoint of obtaining more excellent wear resistance, it is preferably 10% by mass or more, preferably 15% by mass or more. Is more preferable. Further, the content of the natural rubber is preferably 50% by mass or less from the viewpoint of maintaining a high level of anti-slip property.

(Carbon black)
The rubber composition for artificial limb soles of the present invention further contains carbon black in addition to the rubber components described above.
Here, the nitrogen adsorption specific surface area (N ₂ SA) of the carbon black is 110 to 149 m ² / g.
By using carbon black with N ₂ SA of 110 to 149 m ² / g, it is possible to achieve both the reinforcing property of the rubber composition and appropriate flexibility, and obtain excellent wear resistance while maintaining anti-slip properties. be able to.
If the N ₂ SA exceeds 149 m ² / g, the hardness of the rubber after vulcanization increases, so that sufficient anti-slip properties cannot be obtained. If the N ₂ SA is less than 110 m ^{2 / g, the rubber becomes harder.} Since the reinforcing property of rubber is weakened, sufficient wear resistance cannot be obtained. From the same viewpoint, N ₂ SA of the carbon black is preferably 110~149m ² / g, more preferably 115~149m ² / g, in particular to be 125~149m ² / g preferable.
The nitrogen adsorption specific surface area can be measured by the single-point method in accordance with ISO4652-1. For example, after immersing degassed carbon black in liquid nitrogen, the surface of the carbon black is exposed at equilibrium. The amount of adsorbed nitrogen can be measured, and the nitrogen adsorption specific surface area (m ² / g) can be calculated from the measured value.

The type of carbon black is not particularly limited except that it has the above-mentioned N _{2 SA.} For example, any hard carbon produced by the oil furnace method can be used. The type of carbon black is not particularly limited, and for example, carbon black such as GPF, FEF, SRF, HAF, ISAF, IISAF, and SAF grade can be used.

As for the carbon black is preferably DBP (dibutyl phthalate) absorption amount is 80~160cm ³ / 100g, and more preferably 110~140cm ³ / 100g. This is because by using carbon black whose structure is within an appropriate range, it is possible to achieve both the reinforcing property and the anti-slip property of the rubber composition at a higher level.
The carbon black structure is the size of a structure (aggregate of carbon black particles) formed as a result of fusing and connecting spherical carbon black particles.
The amount of DBP absorbed by the carbon black is the amount of DBP (dibutyl phthalate) absorbed by 100 g of carbon black, and can be measured in accordance with JIS K 6217-4 (2008).

The content of the carbon black is 50 to 90 parts by mass with respect to 100 parts by mass of the rubber component. This is because excellent wear resistance can be obtained while maintaining anti-slip properties.
When the content of the carbon black is less than 50 parts by mass with respect to 100 parts by mass of the rubber component, sufficient wear resistance cannot be obtained, while the content of the carbon black is the rubber. If it exceeds 90 parts by mass with respect to 100 parts by mass of the component, sufficient anti-slip property cannot be obtained.
From the same viewpoint, the content of the carbon black is preferably 50 to 80 parts by mass with respect to 100 parts by mass of the rubber component.

(Thermoplastic resin)
The rubber composition for artificial limb soles of the present invention preferably further contains a thermoplastic resin in addition to the above-mentioned rubber component and carbon black.
Since the flexibility of the rubber can be increased by containing the thermoplastic resin, when the rubber composition for the artificial limb sole of the present invention is used for the sole of the artificial limb, the grip force is enhanced and more excellent anti-slip property is obtained. be able to.

Here, the thermoplastic resin is not particularly limited, and various natural resins and synthetic resins can be used. Further, when the rubber composition for a prosthesis sole of the present invention is used for a prosthesis sole, more excellent anti-slip properties can be obtained, and thus petroleum-based resin, coal-based resin, phenol-based resin, rosin-based resin and terpene. It is preferable to use at least one selected from the group consisting of based resins, and it is more preferable to use at least a phenolic resin.

In the synthetic resin, the petroleum-based resin is a decomposed oil distillate containing unsaturated hydrocarbons such as olefins and diolefins, which are by-produced together with basic petrochemical raw materials such as ethylene and propylene by, for example, thermal decomposition of naphtha in the petrochemical industry. Is a resin obtained by polymerizing the mixture as it is with a Friedelcraft type catalyst. Examples of the petroleum-based resin, a C ₅ fraction obtained by thermal cracking of naphtha (co) polymer obtained by aliphatic petroleum resin (hereinafter sometimes referred to as "C ₅ resins".), Naphtha Aromatic petroleum resin (hereinafter, may be referred to as _{"C 9-} based resin") obtained by (co) polymerization of the _{C 9} distillate obtained by thermal decomposition of _{the above, C 5} distillate and C ₉ distillate. obtain a partial copolymerizing copolymerized petroleum resin (hereinafter sometimes referred to as "C ₅ -C ₉ resins".), hydrogenated based or dicyclopentadiene-based such as alicyclic compound-based petroleum resin , Styrene, substituted styrene, or styrene-based resins such as copolymers of styrene and other monomers.

The _{C 5} fraction obtained by thermal cracking of naphtha, usually 1-pentene, 2-pentene, 2-methyl-1-butene, 2-methyl-2-butene, 3-methyl-1-olefin such as butene Diolefin hydrocarbons such as hydrocarbons, 2-methyl-1,3-butadiene, 1,2-pentadiene, 1,3-pentadiene and 3-methyl-1,2-butadiene are included. Further, aromatic petroleum resin obtained by C ₉ fraction (co) polymerization, vinyl toluene, a resin obtained by polymerizing an aromatic carbon atoms 9, indene major monomers, by thermal cracking of naphtha specific examples of the C ₉ fraction obtained, alpha-methyl styrene, beta-methyl styrene, .gamma.-methyl styrene homologs and indene such as styrene, indene analogs such as coumarone and the like. Product names include Petrodin manufactured by Mitsui Petrochemicals, Petrite manufactured by Mikuni Chemicals, Neopolymer manufactured by Nippon Petrochemicals, and Petcol manufactured by Toyo Soda.

Furthermore, in the present invention can be in terms of workability, it is suitably used modified petroleum resin modified petroleum resin comprising the C ₉ fraction. Examples of the modified petroleum resin, an unsaturated alicyclic compound modified with C ₉ petroleum resins, C ₉ petroleum resins modified with a compound having a hydroxyl group, C ₉ petroleum resins modified with an unsaturated carboxylic acid compound Can be mentioned.

Examples of the compound having a hydroxyl group include an alcohol compound and a phenol compound. Specific examples of the alcohol compound include alcohol compounds having a double bond such as allyl alcohol and 2-butene-1,4diol. As the phenol compound, alkylphenols such as phenol, cresol, xylenol, p-tert-butylphenol, p-octylphenol and p-nonylphenol can be used. These compounds having a hydroxyl group may be used alone or in combination of two or more. _{Further, the C 9-} based petroleum resin having a hydroxyl group is a method of thermally polymerizing a (meth) acrylic acid alkyl ester or the like together with a petroleum distillate to introduce an ester group into the petroleum resin and then reducing the ester group. It can be produced by a method of hydrating the double bond after the double bond remains or is introduced therein. The C ₉ petroleum resin having a hydroxyl group, can be used those obtained by the various methods as, Performance, viewed from the manufacturing aspect, it is preferred to use a phenol-modified petroleum resins. The phenol-modified petroleum resins, obtained by cationic polymerization of the C ₉ fraction in the presence of phenol, modified is easy and low cost. Examples of the phenol-modified _{C 9} petroleum resin, for example, Neo polymer -E-130 (manufactured by Nippon Petrochemicals).

Furthermore, the modified C ₉ petroleum resin with an unsaturated carboxylic acid compound is capable of modifying the C ₉ petroleum resin in an ethylenically unsaturated carboxylic acid. Typical examples of such ethylenically unsaturated carboxylic acids include (maleic anhydride) maleic acid, fumaric acid, itaconic acid, tetrahydro (anhydrous) phthalic acid, (meth) acrylic acid, citraconic acid and the like. Unsaturated carboxylic acid-modified C ₉ petroleum resin can be obtained by thermally polymerizing C ₉ petroleum resin and ethylenically unsaturated carboxylic acid. In the present invention, maleic acid-modified C ₉ petroleum resin is preferable. Examples of the unsaturated carboxylic acid-modified C ₉ petroleum resin, for example, Neo Polymer 160 (manufactured by Nippon Petrochemicals).

Further, it can be suitably used C ₅ fraction and C ₉ fraction copolymer resin obtained by thermal cracking of naphtha. Here, the C ₉ fraction is not particularly limited, but is preferably _{the C 9 fraction obtained by thermal decomposition of naphtha.} Specific examples thereof include TS30, TS30-DL, TS35, and TS35-DL of the Struktor series manufactured by SCHILL & SEILACHER.

In the synthetic resin, examples of the coal-based resin include Kumaron inden resin and the like.
Further, in the synthetic resin, examples of the phenol-based resin include an alkylphenol formaldehyde-based resin and a rosin-modified product thereof, an alkylphenol acetylene-based resin, a modified alkylphenol resin, a terpenephenol resin, and the like. Examples thereof include 1502 (manufactured by Hitachi Kasei Kogyo Co., Ltd.) and choresin (manufactured by BASF), which is a p-tert-butylphenol acetylene resin.
Among these synthetic resins, aromatic from the viewpoint of abrasion resistance of the compounded rubber composition, C ₅ fraction and C ₉ fraction copolymer resin, obtained by a C ₉ fraction (co) polymerizing Group petroleum resins, phenolic resins and Kumaron inden resins are preferred.

In the natural resin, examples of the rosin-based resin include gum rosin, tall oil rosin, wood rosin, hydrogenated rosin, disproportionated rosin, polymerized rosin, modified rosin glycerin, and pentaerythritol ester.

In the natural resin, examples of the terpene-based resin include α-pinene-based, β-pinene-based, and dipentene-based terpene resins, aromatic-modified terpene resins, terpene phenol resins, and hydrogenated terpene resins.
Among these natural resins, polymerized rosin, terpene phenol resin, and hydrogenated terpene resin are preferable from the viewpoint of abrasion resistance of the vulcanized rubber composition.

The content of the thermoplastic resin is not particularly limited, but when the rubber composition for the prosthesis sole of the present invention is used for the sole of the prosthesis, more excellent anti-slip property is obtained without lowering the abrasion resistance. From the point of view, it is preferably 5 to 40 parts by mass, more preferably 8 to 35 parts by mass, and particularly preferably 10 to 30 parts by mass with respect to 100 parts by mass of the rubber component.
By setting the content of the thermoplastic resin to 5 parts by mass or more with respect to 100 parts by mass of the rubber component, more excellent anti-slip property can be obtained, and 40 parts by mass or less with respect to 100 parts by mass of the rubber component. By doing so, it is possible to suppress a decrease in wear resistance.

(Other ingredients)
The rubber composition for artificial limb sole of the present invention may contain other components in addition to the above-mentioned rubber component, carbon black and thermoplastic resin to the extent that the effects of the present invention are not impaired.
Other components include, for example, fillers other than carbon black, anti-aging agents, cross-linking accelerators, cross-linking agents, cross-linking accelerators, oils, stearic acid, ozone deterioration inhibitors, surfactants and the like in the rubber industry. Usually used additives can be appropriately included.

Examples of the filler other than carbon black include silica and other inorganic fillers.

Examples of the silica include wet silica, colloidal silica, calcium silicate, aluminum silicate and the like.
Among the above, the silica is preferably wet silica, more preferably precipitated silica. This is because these silicas have high dispersibility and can further improve the low loss property and wear resistance of the rubber composition. Precipitated silica means that the reaction solution is allowed to react in a relatively high temperature, neutral to alkaline pH range at the initial stage of production to grow silica primary particles, and then controlled to the acidic side to aggregate the primary particles. It is the silica obtained as a result of making it.
Further, as the aluminum hydroxide, it is preferable to use Heidilite (registered trademark, manufactured by Showa Denko) or the like.

Examples of the inorganic filler include aluminum hydroxide, clay, alumina, talc, mica, kaolin, glass balloon, glass beads, calcium carbonate, magnesium carbonate, magnesium hydroxide, magnesium oxide, titanium oxide, and potassium titanate. , Barium sulfate and the like.

As the anti-aging agent, known ones can be used and are not particularly limited. For example, a phenol-based anti-aging agent, an imidazole-based anti-aging agent, an amine-based anti-aging agent, and the like can be mentioned. These anti-aging agents may be used alone or in combination of two or more.

As the cross-linking accelerator, known ones can be used and are not particularly limited. For example, thiazole-based vulcanization accelerators such as 2-mercaptobenzothiazole and dibenzothiazil disulfide; Sulfenamide-based vulcanization accelerator; guanidine-based vulcanization accelerator such as diphenylguanidine; tetramethylthium disulfide, tetraethyl thiuram disulfide, tetrabutyl thiuram disulfide, tetradodecyl thiuram disulfide, tetraoctyl thiuram disulfide, tetrabenzyl thiuram disulfide, disulfide. Thiuram-based vulcanization accelerators such as pentamethylene thiuram tetrasulfide; dithiocarbamate-based vulcanization accelerators such as zinc dimethyldithiocarbamate; zinc dialkyldithiophosphate and the like can be mentioned.

The cross-linking agent is also not particularly limited. For example, sulfur, bismaleimide compounds and the like can be mentioned.
Regarding the types of the bismaleimide compound, for example, N, N'-o-phenylene bismaleimide, N, N'-m-phenylene bismaleimide, N, N'-p-phenylene bismaleimide, N, N'-( Illustrate 4,4'-diphenylmethane) bismaleimide, 2,2-bis- [4- (4-maleimidephenoxy) phenyl] propane, bis (3-ethyl-5-methyl-4-maleimidephenyl) methane, and the like. Can be done. In the present invention, N, N'-m-phenylene bismaleimide, N, N'-(4,4'-diphenylmethane) bismaleimide and the like can be preferably used.

Examples of the cross-linking promoting aid include zinc oxide (ZnO) and fatty acids. The fatty acid may be saturated or unsaturated, linear or branched fatty acid, and the number of carbon atoms of the fatty acid is not particularly limited, but for example, a fatty acid having 1 to 30, preferably 15 to 30 carbon atoms. More specifically, cyclohexaneic acid (cyclohexanecarboxylic acid), naphthenic acid such as alkylcyclopentane having a side chain; hexanic acid, octanoic acid, decanoic acid (including branched carboxylic acid such as neodecanoic acid), dodecanoic acid, tetradecane Saturated fatty acids such as acids, hexadecanoic acid and octadecanoic acid (stearic acid); unsaturated fatty acids such as methacrylic acid, oleic acid, linoleic acid and linolenic acid; resin acids such as rosin, tall oil acid and avietic acid. These may be used alone or in combination of two or more. In the present invention, zinc oxide and stearic acid can be preferably used.

When silica is contained as the filler, it is preferable to further contain a silane coupling agent. This is because the effects of reinforcing property and low loss property of silica can be further improved. As the silane coupling agent, known ones can be appropriately used. The content of the preferable silane coupling agent varies depending on the type of the silane coupling agent and the like, but is preferably in the range of 2 to 25% by mass, preferably in the range of 2 to 20% by mass with respect to silica. It is more preferable, and it is particularly preferable that it is 5 to 18% by mass. If the content is less than 2% by mass, the effect as a coupling agent is not sufficiently exhibited, and if it exceeds 25% by mass, gelation of the rubber component may occur.

The oil is mainly used as a softener. In the present invention, the rubber composition for artificial limb sole of the present invention may be contained within a range that does not reduce the reinforcing property such as wear resistance.
Examples of the type of the oil include those conventionally known, and examples thereof include process oils such as aromatic oils, naphthenic oils and paraffin oils, vegetable oils such as coconut oils, and synthetic oils such as alkylbenzene oils.
The oil referred to here is an oil added as a softening agent, and does not include the oil contained in the oil spread SBR and the oil inevitably contained in the rubber composition.

In the rubber composition for artificial leg sole of the present invention, either non-oil-extended SBR or oil-extended SBR can be used as the SBR, but from the viewpoint of maintaining excellent wear resistance, the rubber composition The total amount of oil is preferably 40 parts by mass or less with respect to 100 parts by mass of the rubber component.
The method for adjusting the amount of oil in the entire rubber composition is not particularly limited, but for example, it is carried out by adjusting the amount of oil in the oil spread SBR or adjusting the amount of oil as the softening agent described above. Can be done.

<Sole for artificial limbs>
Next, the artificial limb sole of the present invention will be described.
The sole for artificial limbs of the present invention is characterized in that the rubber composition for artificial limbs sole of the present invention described above is used.
By using the rubber composition for artificial limb sole of the present invention, excellent anti-slip property and wear resistance can be realized.

Here, the artificial limb sole for the present invention can be applied to any artificial limb provided with the sole, but from the viewpoint of more effectively exhibiting the excellent anti-slip property and abrasion resistance of the present invention, it is for competition use. It is preferably attached directly or indirectly to a leaf spring (leaf spring-shaped artificial limb) such as an artificial limb.

FIG. 1 is a side view of a competition prosthesis 1 to which a prosthesis sole 5 according to an embodiment of the present invention is attached. The competition prosthesis 1 has a leaf spring-shaped foot portion 2, and a sole 5 is attached to a contact area on the tip end side of the foot portion 2.
Although not shown, the base end portion of the foot portion 2 is connected to the socket via an adapter, and can be worn by accommodating the stump of the wearer's foot in the socket. As the adapter and socket, those corresponding to the stump position of the foot, such as a thigh artificial limb and a lower leg artificial limb, are used. FIG. 1 shows a foot portion 2 and a prosthesis sole 5 in an upright state of a wearer wearing a competition prosthesis 1.

Hereinafter, in the present embodiment, in the height direction of the artificial limb for competition (height direction when the artificial limb is attached), the side where the foot portion 2 is connected to the adapter is referred to as the connection side, and the side where the foot portion 2 is in contact with the road surface S is the ground contact side. That is. Further, the toe T of the artificial limb 1 for competition refers to the point where the foot portion 2 extends from the connection side and ends. Further, the direction extending parallel to the road surface S from the toe T is called the anterior-posterior direction of the prosthesis. Further, the direction of the foot 2 over the width direction is referred to as the width direction W.

In the present embodiment, the foot portion 2 of the competition prosthesis 1 has a shape extending in a plate shape toward the toe T side via at least one curved portion, or one curved portion 3 in the illustrated example. In addition, as shown in FIG. 1, the foot portion 2 has a straight portion 2a, a curved portion 2b convex to the toe T side, and a curved portion 3 convex to the rear side in the anterior-posterior direction of the prosthesis, in this order from the connection side to the ground contact side. It is composed of a curved portion 2c that is concave on the grounding side and a grounding portion 4 that extends to the toe T side in an arc shape that is convex on the grounding side. However, the artificial limb 1 for competition may be a foot portion 2 having a shape other than that shown in FIG. 1 depending on the type of competition and the will of the athlete.
Further, although the material of the foot portion 2 is not limited, it is preferable to use carbon fiber reinforced plastic or the like from the viewpoint of strength and weight reduction.

The ground contact portion 4 of the foot portion has a contact area 4s extending from the toe T to the curved portion 3 side on the ground contact side, and the artificial limb sole 5 is attached to the contact area 4s. The contact area 4s refers to the entire area in contact with the road surface S when the wearer wearing the competition prosthesis 1 performs a straight running motion, and when the sole 5 is attached, the contact area 4s is the sole. It comes into contact with the road surface S via 5.
The artificial limb sole 5 is attached to the contact area 4s via an adhesive, but the attachment means is not limited to the adhesive, and may be attached using a fastener such as a belt. Further, when the artificial limb sole 5 is attached to the contact area 4s via the adhesive, the adhesive is applied so as to cover at least the contact area 4s, but from the viewpoint of ensuring the adhesiveness of the end portion. , It may protrude from the contact area 4s in the direction of the curved portion 2c.
Further, in the present embodiment, the sole 5 is mounted in direct contact with the contact area 4s, but a cushion material (not shown) may be interposed between the artificial limb sole 5 and the contact area 4s. Here, EVA or urethane resin can be preferably used as the material of the cushion material.

One embodiment of the artificial limb sole 5 of the present invention has a sole bottom surface 5s composed of a plurality of irregularities. Further, in the present embodiment, as shown in FIG. 1, the sole bottom surface 5s has a shape in which arcs X1 and X2 are continuous from the toe T side to the curved portion 3 side, and the contact area 4s of the foot portion 2. It has a shape according to the extending shape of. In the present embodiment, the arcs X1 and the arcs X2 in the contact area 4s of the foot 2 have different radii of curvature, but they may have the same radii of curvature, and they may be in contact with each other. The area 4s does not have to have an arc.

Further, the sole bottom surface of the artificial limb sole 5 of the present invention (hereinafter, may be referred to as "bottom surface of the artificial limb sole") 5s is the artificial limb in a state where the competition artificial limb 1 is worn and the wearer is upright. When the line extending in the width direction W of the foot portion 2 through the contact point C between the bottom surface 5s of the sole and the road surface S is defined as the boundary line CL (see FIGS. 3A and 3B), one of them. It has different performance on the side and the other side. Here, the contact point C between the bottom surface 5s of the artificial limb sole and the road surface S is a point where the wearer first comes into contact with the road surface S when the wearer reaches an upright position. The upright state of the wearer is a healthy foot in which the wearer does not wear an artificial limb when only one of them is an artificial limb, and when both are artificial limbs, the body is supported by one of the artificial limbs. It refers to the state in which the vehicle is lowered onto the road surface S and first comes into contact with the road surface S.
The contact point C between the bottom surface 5s of the artificial limb sole and the road surface S is determined by the shape of the artificial limb, the mounting mode, and the like. (For example, in the present embodiment, as shown in FIG. 1B, the position is located in a region extending in the width direction W from a point of 60% to 70% of the maximum length L1 in the anterior-posterior direction of the prosthesis starting from the toe T of the sole bottom surface 5s. That is, based on the knowledge about the ground contact form obtained by the experiment described later, the boundary line CL of the bottom surface 5s of the artificial limb sole is based on the point C which is the contact point with the road surface S in the upright state of the wearer. It becomes.

The above-mentioned experimental results of the ground contact form of the bottom surface 5s of the sole 5 of the artificial limb sole 5 of the present invention will be described below with reference to FIGS. 2A to 2D. Here, FIGS. 2A to 2D stepwise explain the operation of the foot portion 2 and the ground contact form of the sole bottom surface 5s when the wearer wearing the competition prosthesis 1 having the above configuration travels straight. It is a figure for doing. The upper part of each drawing is a side view of the foot portion 2 and the sole 5 of the competition prosthesis 1, and the lower part of each drawing is the prosthesis when the wearer wearing the competition prosthesis 1 performs a straight running motion. It shows the transition of the ground contact form of the bottom surface 5s of the sole.

Regarding the experimental results of the ground contact form, FIG. 2A shows a state in which the competition prosthesis 1 lifted by the wearer is lowered onto the road surface S and the entire weight is loaded on the competition prosthesis 1. As shown in the lower part of the drawing, the curved portion 3 side of the sole bottom surface 5s with respect to the point C is in contact with the ground.
Further, FIG. 2B is a diagram showing a state in which the wearer steps on the artificial limb 1 for competition with the entire weight loaded after FIG. 2A. From FIG. 2B, in the case of running a healthy person, the bottom surface of the sole of the shoe is generally stepped on in order from the heel side to the toe side of the sole. It can be seen that the bottom surface 5s of the artificial leg sole is in contact with the road surface S on the curved portion 3 side opposite to the toe T side from the point where it first touches the ground.
Further, FIG. 2C is a diagram showing a state in which, after FIG. 2B, the wearer swings the foot opposite to the side on which the competition prosthesis 1 is worn forward and starts the kicking motion of the competition prosthesis 1. From FIG. 2C, it can be seen that when the kicking motion is started, the competition prosthesis 1 is in contact with the road surface S on the toe T side of the bottom surface 5s of the prosthesis sole with respect to the point C.
Furthermore, FIG. 2D is a diagram showing a state immediately before takeoff in which the wearer kicks the competition prosthesis 1 away from the road surface S after FIG. 2C. From FIG. 2D, it can be seen that the ground is further grounded on the toe T side of FIG. 2C in order to kick out from the toe T on the bottom surface 5s of the artificial limb sole.

Then, based on the results shown in FIGS. 2A to 2D described above, in the artificial limb sole 5 according to the embodiment of the present invention, as shown in FIGS. 3A and 3B, the bottom surface 5s of the artificial limb sole 5s. The line extending in the width direction of the foot through the contact point C between the bottom surface 5s of the sole for the artificial limb and the road surface when the wearer wearing the artificial limb for competition is upright is defined as the boundary line CL. It was divided into a part side Q1 and a toe side Q2.
Further, in the artificial toe sole 5 according to the embodiment of the present invention, from the viewpoint of achieving both anti-slip property and abrasion resistance at a higher level, the negative ratio of the curved portion side Q1 with respect to the boundary line CL is 35 to 35 to It is preferable that the ratio is 80% and the negative ratio of the toe side Q2 to the boundary line CL is 55% or less (including 0%).

As shown in FIGS. 2A and 2B, the curved portion side Q1 of the bottom surface 5s of the artificial limb sole is stepped on with the wearer first landing and the total weight is loaded on the competition artificial limb 1. This is the area to do. Therefore, in order to maintain the balance of the entire body even when the wearer loads the entire weight on the competition prosthesis 1, it is important to sufficiently grip the road surface S and realize high anti-slip property.
On the other hand, the toe side Q2 of the bottom surface 5s of the artificial limb sole is an area for the wearer to swing the foot opposite to the side wearing the competition artificial limb 1 forward and kick the competition artificial limb 1. is there. The toe side Q2 is grounded in order toward the toe T, and the wearer pushes the road surface S on the bottom surface 5s of the sole and touches the ground so as to slide, so that the area is particularly prone to wear. Therefore, the toe side Q2 of the bottom surface 5s of the artificial limb sole needs to have higher wear resistance than the curved portion side Q1.
Therefore, the negative ratio (35 to 80%) of the curved portion side Q1 is larger than the negative ratio (55% or less) of the toe side Q2 with respect to the boundary line CL, so that the anti-slip property and the wear resistance are improved. Both can be improved.

Here, the negative ratio refers to the ratio of the area of the bottom surface 5s of the artificial limb sole having unevenness in the plan view to the portion concave with respect to the road surface S in the plan view. With the above configuration, high propulsive force can be exerted during traveling.

Further, regarding the bottom surface 5s of the artificial limb sole, as shown in FIG. 3B, the curved portion side Q1 and the toe side Q2 of the bottom surface 5s of the artificial limb sole are further divided into two in the front-back direction of the prosthesis. Is more preferable.
Specifically, of the curved portion side Q1 of the bottom surface 5s of the prosthesis sole, the negative rate of the portion Q1-1 on the toe T side of the center M1 of the maximum length L1 in the anterior-posterior direction of the prosthesis is 40 to 80%. The negative rate of the other part Q1-2 of the curved portion side Q1 is 35 to 60%, and the negative rate of the part Q2-1 located closer to the toe side of the toe side Q2 of the bottom surface 5s of the artificial leg sole is , 0 to 15%, and the negative rate of the portion Q2-2 located closer to the curved portion is particularly preferably 25 to 55%.

Regarding the curved portion side Q1 of the bottom surface 5s of the artificial limb sole, the portion Q1-1 on the toe T side of the center M1 of the maximum length L1 in the anterior-posterior direction of the artificial limb is the area where the wearer first lands. It is necessary to ensure slip prevention in order to balance the above. Therefore, the negative rate is higher and the drainage performance is higher than that of the other part Q1-2 of the curved portion side Q1 of the bottom surface 5s of the artificial limb sole, so that slip is prevented more reliably and more stable. It is possible to realize running. Further, on the curved portion side Q1 of the bottom surface 5s of the artificial limb sole, the portion Q1-2 on the curved portion side of the center M1 of the maximum length L1 in the anterior-posterior direction of the artificial limb is the portion that first touches the ground in the artificial limb 1. The ground contact portion has changed to the curved portion 3 side of Q1-1, that is, the side opposite to the traveling direction. In the part Q1-2 on the curved part side of the center M1 of the maximum length L1 in the anteroposterior direction of the prosthesis, the movement of the upper body that the wearer tries to move forward and the movement of the ground contact part are temporarily reversed. Therefore, a high propulsive force is required for the kicking operation in the latter half of the ground contact form. Therefore, first, it is important that the portion Q1-2 has a higher rigidity than the portion Q1-1. By providing the portion Q1-2 with a higher rigidity than the portion Q1-1, the stepping motion can be smoothly connected to the kicking motion, and a high propulsive force can be realized.
On the other hand, the toe side Q2 of the bottom surface 5s of the artificial limb sole corresponds to the arc X1 continuous from the toe T with a constant radius of curvature in FIG. Of the toe side Q2 of the bottom surface 5s of the artificial limb sole, the portion Q2-1 located closer to the toe side is finally grounded when the wearer wearing the competition artificial limb 1 performs a kicking motion. , Prone to more severe wear. Therefore, the portion Q2-1 located closer to the curved portion needs to have particularly high wear resistance. That is, on the toe side Q2 of the bottom surface 5s of the artificial limb sole, the portion Q2-1 has higher wear resistance than the remaining portion Q2-2, thereby protecting the sole 5 from severe wear and extending the service life. It can be effectively prolonged.

The specific means for changing the negative ratio described above is not particularly limited, and examples thereof include a method using a pattern composed of irregularities formed by a groove formed on the bottom surface 5s of the artificial limb sole. The case where the gatibu ratio is changed according to the pattern consisting of the unevenness of the bottom surface 5s of the sole will be described below. FIG. 4 is a diagram showing an example of a pattern of the bottom surface 5s of the artificial limb sole 5 of the present invention.

The bottom surface 5s of the artificial limb sole shown in FIG. 4 has a shape in which square corners are rounded in a plan view by forming a concave groove in the sole bottom surface 500s in Q10, and a plurality of land portions 15 are divided. Has been done. Further, in the ground contact region Q10, the land portions 16a and 16b are arranged on the curved portion 3 side of the land portion 15. The land portions 16a and 16b have a shape in which square corners are rounded in a plan view by forming a concave groove in the sole bottom surface 500s, and have a larger area in a plan view than the land portion 15. Further, the land portion 16b has a larger area in a plan view than the land portion 16a. Further, the land portion 17a and 17b having the same shape as the land portion 16a and the land portion 16b are also partitioned on the toe side portion Q2. Further, on the toe T side of the toe side portion Q2 with respect to the land portions 17a and 17b, a land portion 18a having a rectangular shape with rounded corners is formed in a plan view, and the toe T side with respect to the land portion 18a. In addition, the semi-land portion 18b is partitioned in such a manner that the depth of the groove gradually decreases toward the toe T side. Further, a plurality of straight grooves 19a and 19b inclined with respect to the width direction W are continuously arranged along the width direction W on the toe T side of the semi-land portion 18b. The straight groove 19a and the straight groove 19b are inclined in opposite directions with respect to the width direction W.
By having the above-mentioned pattern, in the bottom surface 5s of the artificial limb sole, the negative ratio of the curved portion side Q1 is larger than the negative ratio of the toe side Q2 with respect to the boundary line CL.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples.

<Samples 1-1-1-9>
Each sample of the rubber composition for artificial limb sole was prepared under the conditions shown in Table 1. The blending amount of each component is indicated by the amount (parts by mass) with respect to 100 parts by mass of the rubber component.

<Evaluation>
(1) Abrasion resistance Each sample of the rubber composition for artificial limb sole is vulcanized at 160 ° C. for 15 minutes, and then abraded at a slip ratio of 80% under room temperature conditions using a Ramborn type abrasion tester. The amount was measured and the reciprocal of it was calculated.
For evaluation, the standard rubber composition with the composition shown in Table 1 is used, and the index is displayed when the reciprocal of the amount of wear assumed for the standard rubber composition is 100. The larger the index value, the larger the amount of wear. It shows that it is less and has excellent wear resistance. The evaluation results are shown in Table 1.

(2) Wet grip (anti-slip)
After vulcanizing each sample of the rubber composition for the artificial sole at 160 ° C for 15 minutes, it is cut out to fit the measuring jig with a major axis of 40 mm and a minor axis of 20 mm, and fixed to the measuring jig on a wet iron plate road surface. The frictional force generated when pressing and reciprocating was measured with a load cell, and the dynamic friction coefficient was calculated. The temperature when the frictional force was measured was 15 ° C.
For evaluation, the standard rubber composition with the composition shown in Table 1 is used, and the index is displayed when the resistance value assumed for the standard rubber composition is 100. The larger the index value, the higher the wet grip property. , Shows excellent anti-slip properties. The evaluation results are shown in Table 1.

(3) Comprehensive evaluation The sum of the index values of (1) wear resistance and (2) wet grip property described above was used as the comprehensive evaluation index value and evaluated according to the following criteria. The evaluation results are shown in Table 1.
⊚: The index value is 105 or more for both wear resistance and wet grip.
◯: Both the wear resistance and the wet grip property are 100 or more, and the index value of either one is 105 or more.
Δ: The index value of either the wear resistance or the wet grip property is 105 or more, but the index value of the other is 100 or less.
X: The index value is 100 or less for both wear resistance and wet grip.

(4) Wet grip (evaluation from users)
The artificial limb sole prepared by using the rubber composition for artificial limbs of Sample 1-5 (example of the present invention) was attached to the artificial limbs according to a conventional method. After that, a prosthesis was attached, and a sensory evaluation was performed by walking on a wet iron plate road surface such as a manhole, a white line on a pedestrian crossing, and a stone pavement. For reference, a commercially available sole was attached to the artificial limb according to the information, and then the same sensory evaluation was performed.
Regarding the evaluation, those who did not feel anxiety about slipping on any road surface were given "A", those who felt a little anxiety about slipping on any road surface were given "B", and those who did not feel anxiety about slipping on any road surface were given a balance. Those who felt the risk of breaking were rated as "C". The evaluation results are shown in Table 2.

* 1: RSS # 3
* 2: Oil-extended styrene-butadiene rubber, JSR's "JSR0150"
* 3: Showa Cabot "Show Black N134", N ₂ SA ^{146m 2} / g
* 4: Showa Denko "Heidi Light H-43M"
* 5: Microcrystalline wax, "Ozo Ace 0280" manufactured by Nippon Seiro Co., Ltd.
* 6: Anti-aging agent contains N-phenyl-N'-(1,3-dimethylbutyl) -p-phenylenediamine ("Nocrack 6C" manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd.) * 7: Acceleration of hydrocarbons The agents are 1,3-diphenylguanidine ("Noxeller D" manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd.) and N-cyclohexyl-2-benzothiazolyl sulphenamide ("Noxeller CZ-G" manufactured by Ouchi Shinko Chemical Industry Co., Ltd.). And di-2-benzothiazolyl disulfide (“Noxeller DM-P” manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd.) * 10: Petroleum hydrocarbon process oil, manufactured by Idemitsu Kosan Co., Ltd., trade name “DAIANA PROCESS OIL NS” -28 "
* _11: C 5 -C ₉ resin, manufactured by Tosoh Corporation "Petro tack 90"
* 12: Rosin-based resin, "Haritak AQ-100B" manufactured by Harima Chemicals, Inc.
* 13: phenolic resin, BASF Co., Ltd. * 14: _{C 5} resin, manufactured by Nippon Zeon Co., Ltd. "Quinton A100"
* 15: Aromatic petroleum resin, "Nisseki Neopolymer 140" manufactured by Nisseki Neopolymer Co., Ltd.
* 16: Terpene phenol resin, "YS Polystar S145" manufactured by Yasuhara Chemical Co., Ltd.
* 17: Di-2-benzothiazolyl disulfide, "VP1405" manufactured by S & S Japan Co., Ltd.
* 18: Hicis butadiene rubber, "Nipol BR1220N" manufactured by Zeon Corporation

From the results in Table 1, it was found that the sample corresponding to the example of the present invention had a higher overall evaluation than the sample of the comparative example, and both wear resistance and anti-slip property were compatible at a higher level. In addition, from the results in Table 2, it was found that the artificial limb sole using the sample of the present invention gives the user an evaluation of excellent anti-slip properties.

According to the present invention, there is provided a rubber composition for an artificial limb sole capable of improving anti-slip property and abrasion resistance when used for an artificial limb sole, and an artificial limb sole having excellent anti-slip property and abrasion resistance. it can.

1: Artificial limbs for competition 2: Foot, 2a: Straight part, 2b, 2c: Curved part 3: Curved part 4: Grounding part, 4s: Contact area 5: Sole for artificial limbs, 5s, 500s: Bottom surface 15 of the sole for artificial limbs , 16a, 16b, 17a, 17b, 18a: land part, 18b: semi-land part 19a, 19b: straight groove X1, X2: arc Q1, Q1-1, Q1-2: curved part side part, Q2, Q2-1 , Q2-2: Toe side

Claims (7)

A rubber component containing 50% by mass or more of styrene-butadiene rubber and
_{Carbon black having a nitrogen adsorption specific surface area (N 2} SA) of 110 to 149 m ² / g, which is 50 to 90 parts by mass with respect to 100 parts by mass of the rubber component.
A rubber composition for artificial limb soles, which comprises. The rubber composition for artificial limb sole according to claim 1, further comprising 5 to 40 parts by mass of a thermoplastic resin with respect to 100 parts by mass of the rubber component. The prosthesis according to claim 2, wherein the thermoplastic resin is at least one selected from the group consisting of petroleum-based resins, coal-based resins, phenol-based resins, rosin-based resins, and terpene-based resins. Rubber composition for sole. The rubber composition for artificial limb sole according to any one of claims 1 to 3, wherein the rubber component further contains natural rubber. A sole for artificial limbs, which comprises using the rubber composition for artificial limb sole according to any one of claims 1 to 4. The sole for artificial limbs according to claim 5, wherein the sole for artificial limbs is directly or indirectly attached to a leaf spring. The artificial limb sole is attached to a contact area extending from the toe to the curved portion side of a competition artificial foot having a leaf spring-shaped foot portion extending to the toe side via a curved portion, and is composed of a plurality of irregularities. Has a patterned bottom surface
The bottom surface of the artificial limb sole has a boundary line extending in the width direction of the foot portion through the contact point between the bottom surface of the artificial limb sole and the road surface in a state where the wearer wearing the artificial limb for competition stands upright. The present invention is characterized in that the negative ratio on the curved portion side of the boundary line is 35 to 80%, and the negative ratio on the toe side of the boundary line is 55% or less. Item 5. The sole for artificial limbs according to item 5.

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