JPS6152467A - Seal member for diaphragm and the like - Google Patents

Abstract

PURPOSE:To improve the medicine resistance and flexibility by applying perfluoro elastomer film at least onto the contact face with fluid on seal member body. CONSTITUTION:Perfluoro elastomer film 4 is applied at least onto the contact face with fluid 2 in said face 2 or the rear face 3 of seal member body 1. Consequently, the seal member body 1 can be protected from medicines through perfluoro elastomer film having excellent medicine resistance to achieve cost reduction because relatively inexpensive synthetic rubber can be employed as the material of seal member body 1. While since perfluoro elastomer has high resiliency, it can follow resilient deformation of seal member body thus to cause no peeling of film.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a sealing member such as a diaphragm mainly used in a chemical liquid transport pump.

(Prior art) Conventionally, synthetic rubber (for example, NR, NBR, SBR) has been used as a material for diaphragms, depending on usage conditions and applications.
, CR, etc.), synthetic rubber with reinforced fabric, fluororesin alone (e.g. PTFE, etc.), composites of both synthetic rubber and fluororesin, and composites of synthetic rubber with reinforced fabric and fluororesin. etc. are used. In particular, when using chemicals that general synthetic rubber cannot withstand or whose ingredients are unknown, or when using various chemicals alternately, the main body is made of synthetic rubber and a fluororesin material is used on the side that comes into contact with the chemical solution. However, those made of fluororesin alone are hard and lack flexibility, and those that use fluororesin only on the chemical contact side have a far lower elastic modulus, making it difficult for the body to elongate. However, there was a problem in that the elongation of the fluororesin material could not be followed, and the fluororesin material was damaged, making it impossible to withstand long-term use. Therefore, recently, a diaphragm made of perfluoroelastomer has been proposed. The product name of perfluoroelastomer is ``Callenz'' (Devon Co., Ltd.), and it combines the chemical resistance of a fluororesin (trade name: Teflon) with the elasticity of rubber. However, there are problems in that the use of perfluoroelastomer alone is expensive and that it is molded using gltIIi.

(Problems to be Solved by the Present Invention) The present invention has been made in view of the above points, and its purpose is to provide an inexpensive and durable product that is rich in chemical resistance and flexibility. The present invention provides a sealing member such as a diaphragm.

(Means and Embodiments for Solving Problems) The present invention will be described in detail below based on embodiments shown in the drawings.

FIG. 1 shows an embodiment in which a diaphragm is used as a seal part, and the tip of a drive shaft is inserted into the center of a membrane-like seal member body 1. Reference numeral 4 denotes a perfluoroelastomer film, which is bonded to the fluid contact surface 2 of the sealing member main body 1, which is in contact with a fluid such as a chemical solution.

FIG. 2 shows an embodiment in which a piston is used as a sealing member, and a film 4° is applied to the fluid contacting surface 2 and back surface 3 of the sealing member main body l. 4 is a cylinder, and 5 is a piston rond.

(Effects of the present invention) As described above, the present invention has a perfluoroelastomer film coated on at least the fluid contact surface or the back surface of the sealing member body. The seal member body can be protected from chemical liquids using a manufactured film, and therefore, relatively inexpensive synthetic rubber can be used as the material for the seal member body, reducing costs.Furthermore, since the perfluoroelastomer is used with the film facing down, the seal member body can be protected from chemicals. The difficulty of molding perfluoroelastomer does not pose a problem during the manufacturing stage of the member, and since perfluoroelastomer has high elasticity, it can follow the elastic deformation of the sealing member body, so the film It won't peel off,
Furthermore, since perfluoroelastomer has excellent heat resistance, it has the advantage that it can be used even with high-temperature fluids.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a first embodiment of the present invention, and FIG. 2 is a sectional view showing a second embodiment of the same.

Claims (1)

[Claims] (1) A sealing member such as a diaphragm, which has a perfluoroelastomer film adhered to at least the fluid contacting surface or back surface of the sealing member body.