JPH10272178A - Prosthesis made of polyurethane for human body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to simple wipe off any stain attached with solvent, by reacting polyester polyol comprising a mixture of succinic acid and glycol with the number of functional groups set at a specified value with fatty isocianate and curing if to form a polyurethane prosthesis for human body. SOLUTION: Polyester polyol comprising a mixture of succinic acid, glycol with two functional groups and glycol with three functional groups is cured by a reaction with fatty isocianate to form a urethane prosthesis of human body. Now, the mixing ratio of the polyester polyol to the fatty isocianate is determined to be 0.7-1.2 by a functional group molar ratio of NCO/OH and a thremosensitive catalyst is previously added to the polyester polyl. Moreover, the catalyst herein used is an octyl acid salt of 1,8-diaza-bicyclo (5, 4, 0) undecene-7. This enable obtaining of the prosthesis for human body having a human skin touch whiteout soiling, wearing and discoloring for a long time of period.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a human body prosthesis used as a substitute for fingers, hands, ears, feet, and nose lost due to an accident, illness, or the like, that is, a human body prosthesis.

[0002]

2. Description of the Related Art When an operator loses his / her hand or finger due to an accident or illness,
Due to the bad impression from the exterior, the prosthesis has an appearance that accurately reproduces the skin color and the wrinkles on the skin surface that are difficult to distinguish from the hands, fingers, etc. of healthy people, and is used for such prostheses The material used is mainly polyvinyl chloride or a polyvinyl chloride-silicone rubber composite.

[0003]

In the case of vinyl chloride or silicone resin used in conventional artificial hands, artificial legs, artificial ears, etc., if dirt, especially magic ink, etc. adheres, ink can be wiped with a solvent such as alcohol. There was a problem that traces remained and could not be completely removed. In addition, there is a problem that a fingertip or the like is worn in a short period of time, and even if it is realistically formed, a fingerprint or the like disappears due to abrasion and cannot be used for a long time. In view of the above, the present invention provides a prosthetic hand, a prosthesis, and a prosthesis which can be easily wiped off with a solvent even when dirt adheres, and have a feeling of human skin without wear and discoloration for a long period of time.

[0004]

The traces of stains, especially paints and inks such as magic ink, remain when they adhere to the prosthetic hand, causing the material constituting the prosthetic hand to swell microscopically.
This is because components such as ink enter between molecules. In other words, in order to completely wipe these off, it is necessary to dramatically improve the solvent resistance of the substrate. Further, the hardness is required to be 50 or less according to JIS-A because a texture with a feeling of human skin is required. In the present invention, polyurethane was selected from the viewpoint of wear characteristics. However, a polyester-based polyurethane elastomer obtained by using a general-purpose polyester polyol composed of adipic acid and glycol generally has excellent abrasion resistance as known, but does not have sufficient solvent resistance.

[0005] Therefore, attention was first paid to the polyol component, and succinic acid having fewer carbon atoms than the conventionally used adipic acid was used as the acid component constituting the polyol. In addition, ordinary polyurethane elastomers need to be prepolymerized by reacting a polyol and an isocyanate in advance, and then adding a low molecular weight elastomer such as 1,4-butanediol or trimethylolpropane as a crosslinking agent component. However, in this method, it is very difficult to produce a low-hardness product having a JIS-A of 50 or less, and using a polyol containing succinic acid as a component. When a prepolymer is synthesized, the viscosity of the prepolymer is significantly increased, and it is difficult to mix a crosslinking agent component and inject the mixture into a mold. . Therefore, in the present invention, means for mixing the polyol component and the isocyanate component at once is used in order to prevent the viscosity from increasing by prepolymerization. In this case, when the number of functional groups of the polyol is bifunctional used in a normal prepolymer method, the obtained polyurethane molded product becomes a linear polymer, and has a low hardness, which is soft forever even when heated. There was no "green strength" and demolding was difficult.

Therefore, in the present invention, the releasability is improved by forming a mixture of the bifunctional and trifunctional glycol components constituting the polyol and giving the polyol a certain degree of branching (crosslinking point). The molar ratio of the OH group in the polyol to the NCO group in the isocyanate (functional ratio of NCO / OH) is 0.7 to 1.2 as the mixing ratio of the polyol and the isocyanate.
I tried to be. That is, when the ratio is less than 0.7, the reactivity becomes poor and the uncrosslinked portion increases in the network chain of the obtained urethane molded product, resulting in poor solvent resistance.
On the other hand, when the ratio exceeds 1.2, the elongation becomes small and the feeling of human skin disappears. When the ratio becomes 1.5 or more, the demolding after molding is remarkably reduced. Further, the prosthesis or the like requires that the molded product has a thickness of about 0.5 m to 1.5 mm and is hollow. Therefore, as a molding method, a method of pouring a liquid into a mold, curing only the surface of the mold and hardening the inside without hardening the inside, immediately removing the excess liquid, dipping the mold into the liquid and curing only the vicinity of the surface It is necessary to take a method such as a method of turning over the formed product, or a method of spraying a mold.

In the above-mentioned methods, it is necessary that only the vicinity of the mold surface has a rapid curing property and the inside thereof does not cure. Therefore, in the present invention, a temperature-sensitive catalyst is added to the polyol in advance. After holding the mold at or above the activation temperature of the catalyst used, apply liquid to the mold and solidify only the surface that is in contact with the mold. Did not proceed. The temperature-sensitive catalyst used in the present invention is a diazabicycloamine salt, and specifically,
1,8-diaza-bicyclo- (5,4,0) undecene-7 (DBU) or 1,
5-diazabicyclo- (4,3,0) -nonene-5 (DBN) octylate, toluenesulfonate, oleate, formate, phenol salts, etc. Salts are preferably used. Further, the reason that the isocyanate used in the present invention is limited to the aliphatic isocyanate is that the hardness can be reduced, there is no yellowing seen in the aromatic isocyanate, and it is possible to completely wipe off the dirt, and This is because, since the solvent resistance of the molded product is improved, the type of solvent used for wiping can be widely selected, and thus the molded product can be used for a long period without stain, abrasion, and discoloration. Examples of such aliphatic isocyanates include hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), 2,2,4-trimethylhexamethylene diisocyanate (TMDI), and dicyclohexylmethane. Diisocyanate (H ₁₂ MDI) or a modified form thereof (for example, dimer, trimer, isocyanurate, urea, prepolymer).

[0008]

【Example】

Example 1 A polyol composed of succinic acid and difunctional and trifunctional glycol ("OHN 165" manufactured by Nippon Polyurethane Industry Co., Ltd .; hydroxylation = 60 KOHmg / g) was previously decompressed, dehydrated and dehydrated at 70 ° C. for 12 hours. Foam treated. As a catalyst having a temperature sensitivity to 100 parts of this polyol, 0.4 part of 1,8-diazabicyclo- (5,4,0) -undecene-7 octylate (“U-CAT102” manufactured by San-Apro Co.) 0.5 part of the coloring agent was mixed. Isophorone diisocyanate (“Desmodur I” manufactured by Sumitomo Bayer Urethane Co., Ltd .; NCO = 37.6%) is used as an aliphatic isocyanate in this mixed polyol.
Add 8.4 parts to 100.9 parts of the above mixed polyol so that O / OH = 0.8, and add 2 to 2 so as not to bite the air.
The mixture was mixed for 3 minutes and poured into a prosthetic hand-shaped mold preheated to 150 ° C. After pouring, the mold was turned upside down for about 1 minute, and the excess liquid was discarded. After that, the mold was slowly rotated and crosslinked at a temperature of 150 ° C. for 10 minutes. After cooling, about 1mm
The thick hollow molded product was taken out and post-crosslinked at 80 ° C. for 12 hours to obtain a prosthetic hand.

[0009]

[Example 2] Mixed polyol so that NCO / OH = 1.0
Example 1 was repeated except that 11.9 parts of isocyanate was added to 100.9 parts.

[0010]

[Example 3] Mixed polyol so that NCO / OH = 1.2
Example 1 was repeated except that 14.3 parts of an aliphatic isocyanate was added to 100.9 parts.

[0011]

Example 4 The procedure was performed except that 14.6 parts of an isocyanurate of HDI (“Sumidur N3500” manufactured by Sumitomo Bayer Urethane Co., Ltd .; NCO = 21.6%) was used as an aliphatic isocyanate so that NCO / OH = 0.7. Same as Example 1.

[0012]

Comparative Example 1 The procedure of Example 1 was repeated except that 7.2 parts of aliphatic isocyanate was used so that NCO / OH was 0.6.
In Comparative Example 1, the liquid remaining on the mold surface did not cure even after 1 hour, was sticky, and could not be removed from the mold.

[0013]

Comparative Example 2 The procedure of Example 1 was repeated except that 15.5 parts of an aliphatic isocyanate was used so that NCO / OH was 1.3. When the mold was released, the elongation was small and it was easy to shake. The molded product had a high hardness and a small extension, and lacked the feel of human skin.

[0014]

Comparative Example 3 The procedure of Example 1 was repeated except that 11.1 parts of an aromatic 4,4′-diphenylmethane diisocyanate (“J602” manufactured by Sumitomo Bayer Urethane Co., Ltd., NCO = 28.4%) was used as the isocyanate. The molded article had a high hardness, and when left outdoors for one month in addition to giving a feeling of human skin, the molded article became brownish.

[0015]

Comparative Example 4 Adipic acid as a polyol, bifunctional and trifunctional
Example 1 was repeated except that a functional blend glycol (“Nipporan 4032” manufactured by Nippon Polyurethane Co., Ltd .; hydroxyl value = 60 KOHmg / g) was used. Table 1 summarizes the evaluation results.

[0016]

[Table 1]

[0017]

According to the present invention, it is possible to provide a prosthetic hand, a prosthesis, a prosthesis, etc., which have a feeling of human skin that does not become dirty, worn or discolored for a long period of time. The product has a remarkable effect that a stain such as magic ink can be easily wiped off.

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Toshiyuki Takao 447-1 Fukuda, Fukusaki-cho, Kanzaki-gun, Hyogo Prefecture Fukushin Electric Machine Co., Ltd.

Claims (4)

[Claims] A polyurethane human prosthesis formed by reacting and curing a polyester polyol composed of a mixture of succinic acid, a glycol having two functional groups and a glycol having three functional groups and an aliphatic isocyanate. 2. The polyester polyol and the aliphatic isocyanate are mixed in a molar ratio of NCO / OH of from 0.7 to 1.2.
The prosthesis for human body according to claim 1, wherein 3. The polyester polyol according to claim 1, wherein a temperature-sensitive catalyst is added in advance.
Or the prosthesis for human body according to 2 4. A catalyst comprising 1,8-diaza-bicyclo- (5,4,
0) The prosthesis for human body according to any one of claims 1 to 3, wherein an octylate of undecene-7 is used.