Elastomer molding for endoscope

Abstract

The invention provides a flexible tube for an endoscope, which is excellent in elasticity (impact resilience), has suitable flexibility and also has chemical resistance. Disclosed is a flexible tube for an endoscope including a flexible-tube material covered thereon with a jacket, wherein the jacket contains two or more thermoplastic polyester elastomers crosslinked therein.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application is based upon and claims the benefit of priority from prior Japanese Patent Application No. 2008-026669, filed Feb. 6, 2008, the entire contents of which are incorporated herein by reference.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The present invention relates to an elastomer molding and in particular to an elastomer molding as a flexible tube for an endoscope.[0004]2. Description of the Related Art[0005]In an endoscope, a flexible elastomer molding is used as a jacket for flexible tube. Because an endoscope is repeatedly used and should be cleansed and sterilized every time it is used, the jacket for a flexible tube should be impermeable to body fluids, cleaning liquids, antiseptic solutions etc. The jacket for a flexible tube should have such suitable flexibility and elasticity as not to impair insertion into the body cavity.[0006]The conventional jacket for an endoscopic flexible tube has been f...

AI Technical Summary

Benefits of technology

[0010]An object of the present invention is to provide a flexible tube for an endoscope, which is excellent in elasticity (impact resilience), has suitable flexibility and also has chemical resistance.

[0011]For regulating flexibility and for improving chemical resistance, the inventors have melt-mixed a thermoplastic polyester elastomer (TPC) comprising PBN as a hard segment, with TPC comprising PBT. However, these two TPCs are not completely compatible with each other because of the difference in their segments. Accordingly, the resulting mixture showed significant deterioration in elasticity and could not be satisfactory in resistance to various chemical solutions, for use as a jacket of a flexible tube for an endoscope. Hence, the inventors made extensive study, and as a result, they found that crosslinking of two or more TPCs is effective, and the present invention was thereby completed.

[0016]TPC can be crosslinked by various methods. A method of comprising a carbodiimide compound is particularly effective because the compound can also functions as a hydrolysis-resistant agent. The carbodiimide used is less liable to exhibit blooming as the molecular weight increases, thus reducing its eluted amount. Accordingly, the carbodiimide compound can be preferably used when the elastomer molding is used for medical purposes. When the flexibility of the elastomer molding is to be further increased (softened), a plasticizer may be added. The elastomer molding according to the present invention has TPC molecules chemically bound to one another and is thus less liable to exhibit plasticizer bleeding than a simple mixture of non-crosslinked TPCs.

[0017]The thus constituted elastomer molding of the present invention and an endoscopic flexible tube using the same are excellent in elasticity (impact resilience) and have appropriate flexibility because two kinds of thermoplastic elastomers are crosslinked with each other. Accordingly, they have an excellent distinctive feature of excellent insertability to relieve the pain (burden) of a patient. The elastomer molding of the present invention and an endoscopic flexible tube using the same are not only resistant to various cleaning liquids, antiseptic solutions and low-temperature plasma sterilization but are also excellent in hydrolysis resistance. Therefore, they can be autoclaved (sterilization with steam under high pressure) which is useful in prevention of infection, and can maintain high insertability over a long period.

Problems solved by technology

However, these two TPCs are not completely compatible with each other because of the difference in their segments.

Accordingly, the resulting mixture showed significant deterioration in elasticity and could not be satisfactory in resistance to various chemical solutions, for use as a jacket of a flexible tube for an endoscope.

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