JPS6053528A - Vacuum vessels of synthetic resin and parts therefor - Google Patents

Abstract

PURPOSE:The titled vacuum vessel that is composed of a synthetic resin of polybutylene terephthalate (PBT), thus being corrosion-free, even when a corrosive gas enters into the exhausting system, achieving electrically complete insulation between the vessel and the earth, further being light in weight, easily disposable after use, and inexpensive. CONSTITUTION:The objective vacuum vessel is produced, preferably by reinforcing a synthetic resin of PBT, preferably with excellent vacuum properties, having He permeability of less than 5X10<-10>cc(NTP)cm<2>.sec.Atm, releasing gas of less than 5X10<-7>Torr.l/sec.cm<2>, resistant to usual organic solvents, free from solvent cracks, with a useful component, e.g., mineral fibers. The resultant vessel is preferably coated with a netal nitride at the surface exposed to the vacuum as well as the surface of the boundary part between the air and the vacuum.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a synthetic resin vacuum container, interior parts of the same-walled container, and parts for intervening vacuum equipment.
In particular, what physical characteristics are required for vacuum containers, interior parts of vacuum containers, and vacuum equipment parts? The present invention relates to a vacuum container molded or welded using a plate as a basic unit and the above-mentioned parts, and another object of the present invention is to provide a vacuum container having higher vacuum characteristics. In the case where a metal nitride film is formed on the surface of the synthetic resin gold base material.

゛Recently, with the increasing demand for robust and lightweight vacuum containers and parts to be assembled in a vacuum, Demands for the system: (2) Although the vacuum characteristics are not subject to very severe conditions, since the process involves processing corrosive liquids, etc. in a wide temperature range under reduced pressure, it is necessary to completely encapsulate such a processing environment. The current situation is that the demand for vacuum vessels, vacuum parts, and vacuum exhaust systems that can withstand long-term operation is increasing.

The inventors have spent a lot of time searching for materials other than metals that would meet the above requirements, but polybutylene terephthalate (PBT) based synthetic resins are currently only reasonably satisfactory. The results showed that the vacuum properties could be further improved if improvements were made.

A complete comparison of the physical properties of PBT-based synthetic resin with, for example, structural steel commonly used in vacuum systems is as follows: In the present invention, the upper limits of the amount of released gas and the permeability to He are set as described above. The reason for this limitation is that the amount of released gas and H
Transparency to e? This is because it is necessary to have it.

When the PBT of the present invention is used for vacuum containers and their parts, it is preferably reinforced with useful ingredients depending on the required mechanical properties, such as containing a small amount of mineral fiber or carbon fiber, for example, about 3 oz. Reinforced PBT is preferred.

Vacuum containers or parts made of PBT-based synthetic resin can be fully used by evacuating immediately after wiping the surface with acetone, chlorocene, etc., but more advanced vacuum characteristics are required. In some cases, it is necessary to deposit a metal nitride coating on the parts exposed to the vacuum atmosphere and on the interface between the atmosphere and the vacuum.

Known reactive vapor deposition is preferable as this coating means. In the case of a large-capacity vacuum container, an evaporation source may be installed in the container, and metal nitrides may be generated while introducing a reaction gas and adhered to the inner wall of the container. I can do it.

Also, if PBT is used for parts where corrosive gases continuously flow into, for example, the rotary bong,
It is extremely useful because it does not corrode like conventional stainless steel.

Furthermore, since members with complex shapes are made of synthetic resin, they can be easily formed by injection molding or the like, and standard parts can be produced particularly at low cost.

The present invention has the above configuration, and the main effects of the present invention are listed as follows.

(/) Even if etching gas enters the exhaust system, there is no need to worry about corrosion as long as this synthetic resin is used in the air contact parts.

(,2) Since the container can be completely electrically insulated from the ground side, plasma discharge can be stably sustained, for example.

(3) It is lightweight and extremely easy to handle.

(Hiroshi) Standard parts are particularly inexpensive because components with complex shapes can be processed and formed into one piece.

(j) Disposal after use, such as crushing and reducing volume by low-temperature heating, is easier and cheaper than with whole assembly materials.

Claims (3)

[Claims] (1) Vacuum containers, container interior parts, and parts for vacuum equipment, all of which are characterized by being composed of polybutylene terephthalate-based synthetic resin. (2) Polybutylene terephthalate is a resin with excellent vacuum properties and the following physical properties: Helium gas permeation (lj-4!x10-"dc (NT
P) crl・sec・It-released gas amount lj X/
The vacuum vessel according to claim 1, which is constructed of a member that has a 0' Torrs of 7% sec/cttr, is resistant to general organic solvents, and has properties that do not cause vent cracks. Container interior parts and vacuum equipment parts. (3) Claim 1, wherein the polybutylene terephthalate-based synthetic resin is reinforced with useful ingredients.
Vacuum containers, internal parts of the containers, and parts for vacuum equipment as described in Section 3. (The surfaces exposed to the vacuum atmosphere and the surfaces at the boundary between the atmosphere and vacuum of vacuum containers made of lyphobutylene terephthalate synthetic resin, interior parts of the containers, and parts for vacuum equipment are coated with metal nitride. All features: X-wall container;
Container interior parts and vacuum equipment parts.