JPH0242864B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a seal ring for sealing an opening/closing device, such as an oil seal for an opening/closing valve or a sliding O-ring for a butterfly valve.

Generally, in opening/closing devices such as manual butterfly valves, the opening/closing seal ring is used as an opening/closing seal ring built into the opening/closing device.When the opening/closing member presses against a fixed member and is closed, the opening/closing member is inserted between the two members and seals the gap, while the opening/closing member is fixed. The seal ring, which is used to release one of the two members together with the other when the member is released, has mechanical properties such as wear resistance and sealing properties (elastic properties), as well as
The surface of the seal ring has good non-adhesion and lubricity to facilitate release from the component.
There is a need to eliminate malfunctions of this type of switching device and improve its opening/closing performance. Synthetic rubber conventionally used as seal rings for this type of opening/closing has good durability, but its non-adhesive properties are poor, and the opening/closing member may stick to the fixed member due to the seal ring, causing the opening/closing operation to be impossible. Trouble was occurring.

In order to eliminate the drawbacks of the conventional examples, the present invention provides a sealing ring for a switchgear, which has sufficient non-adhesion and lubricity on its surface while maintaining sufficient sealing performance. By creating a new product with excellent characteristics, it is possible to eliminate defects in the opening/closing operation of a switchgear incorporating the same, and to improve its operating characteristics. Particularly for use in vacuum equipment, there is an advantage that no lubricant is required. That is, in the present invention, when the opening/closing member of the opening/closing device is in pressure contact with the fixed member, the opening/closing member is interposed between the two members to seal the gap, while when the opening/closing member is separated from the fixed member and the opening/closing member is opened, either one of the two members The opening/closing seal ring is designed to be separated from the other member at the same time, and is made by coating the surface of the synthetic rubber body with a fluororubber paint containing fluororubber, fluororesin, an aminosilane compound, and a liquid carrier and curing it. By incorporating the sealing ring having such a configuration into the opening/closing device, sufficient sealing properties can be obtained when the opening/closing device is closed, and sufficient sealing properties can be obtained when the opening/closing device is opened. Due to its excellent non-adhesive properties, the opening/closing operation can be performed smoothly and reliably, and the defects in the opening/closing operation of the conventional opening/closing operation have been completely eliminated.

Examples of the synthetic rubber used in the sealing ring according to the present invention include fluorocarbon rubber, chloroprene rubber, acrylic rubber, ethylene propylene diene polymethylene (EPDM), and nitrile butadiene rubber (NBR). Further, the fluororubber used in the present invention is a highly fluorinated elastic copolymer, and a particularly preferred fluororubber is usually 40 to 85 mol% of vinylidene fluoride and a copolymer thereof. Elastic copolymers with at least one other fluorine-containing ethylenically unsaturated monomer may be mentioned. In addition, for fluororubber containing iodine in the polymer chain, for example, 0.001 to 10% by weight, preferably 0.01 to 5% by weight, at the end of the polymer chain.
Elastic copolymer containing 40 to 85 mol % of vinylidene fluoride as described above and at least one other fluorine-containing ethylenically unsaturated monomer that can be copolymerized with the above-mentioned 40 to 85 mol % of vinylidene fluoride. It is a fluoro rubber whose main composition is coalescence (see JP-A-52-40543).
Other fluorine-containing ethylenically unsaturated monomers that can be copolymerized with vinylidene fluoride to give an elastic copolymer include hexafluoropropylene,
Representative examples include pentafluoropropylene, trifluoroethylene, trifluorochloroethylene, tetrafluoroethylene, vinyl fluoride, perfluoro (methyl vinyl ether), perfluoro (ethyl vinyl ether), perfluoro (propyl vinyl ether), etc. be done. Particularly desirable fluororubbers are vinylidene fluoride/hexafluoropropylene dielastic copolymers and vinylidene fluoride/tetrafluoroethylene/hexafluoropropylene terelastic copolymers. In addition, the fluororesins used in the present invention include polytetrafluoroethylene,
Tetrafluoroethylene and at least one other ethylenically unsaturated monomer copolymerizable with it (e.g. ethylene, olefins such as propylene, hexafluoropropylene, vinylidene fluoride, chlorotrifluoroethylene, vinyl fluoride) Examples include copolymers with halogenated olefins, perfluoroalkyl vinyl ethers, etc.), polychlorotrifluoroethylene, and polyvinylidene fluoride. Among these, preferred fluororesins are polytetrafluoroethylene, tetrafluoroethylene and hexaflupropylene, perfluoromethyl vinyl ether,
It is a copolymer with at least one of perfluoroethyl vinyl ether and perfluoropropyl vinyl ether (usually contained in an amount of 40 mol% or less based on tetrafluoroethylene). Furthermore, the aminosilane compound used in the present invention not only functions as a vulcanizing agent for fluorocarbon rubber, but also appears to greatly contribute to improving the adhesion to the base material, and can be safely used in liquid media. be. Typical compounds include γ-aminopropyltriethoxysilane (hereinafter referred to as A-1100), N-β
-Aminoethyl-γ-aminopropyltrimethoxysilane, N-(trimethoxysilylpropyl)
Ethylenediamine, N-β-aminoethyl-γ-
Examples include aminopropylmethyldimethoxysilane, γ-ureidopropyltriethoxysilane, β-aminoethyl-β-aminoethyl-γ-aminopropyltrimethoxysilane, and the like.

Furthermore, the liquid carrier used in the present invention is selected from organic solvents such as lower ketones, lower esters, and cyclic ethers, water, and mixtures of water and water-soluble organic liquids. Examples of water-soluble organic liquids include alcohols. can.

Furthermore, other inorganic fibrous substances contained in the fluororubber paint of the present invention include glass fiber,
Examples include carbon fiber, asbestos fiber, and potassium titanate fiber.

In addition, representative examples of amine compounds (hereinafter referred to as amine compounds) that may be optionally added to the fluororubber paint of the present invention include ethylamine, propylamine, butylamine, benzylamine, allylamine, n-amylamine, and ethanolamine. Monoamines such as ethylenediamine, trimethylenediamine, tetramethylenediamine, hexamethylenediamine, 3,9-bis(3-aminopropyl)-2,4,8,10-tetraoxaspiro[5,5]undecane (hereinafter referred to as V-
Examples include diamines such as 11), polyamines such as diethylenetriamine, triethylenetetramine, tetraethylenepentamine, and pentaethylenehexamine, and among these, amine compounds having two or more terminal amino groups are preferred.

To prepare the fluororubber paint of the present invention, usually
The pigment, acid acceptor, filler, etc. described above are blended into a mixture of fluororubber, fluororesin, and liquid carrier according to a conventional method (a surfactant may be further used if necessary). The aminosilane compound represented by the above general formula and, if necessary, an amine compound are added to the obtained dispersion (additives such as the pigment, acid acceptor, filler, etc. may be added as necessary), and the process is carried out by a conventional method. By mixing thoroughly, a uniform fluororubber paint can be obtained.

The ratio of fluoro rubber and fluoro resin is 95:5 by weight.
It is desirable that the ratio is ~35:65. If the ratio of fluororesin is less than the above lower limit, the desired improvement in non-adhesiveness and lubricity will not be achieved sufficiently; on the other hand, if it is greater than the above upper limit, the desired thickness will not be achieved. It is difficult to obtain a coating film, and cracks and pinholes are likely to occur in the coating film.

The amount of the aminosilane compound added is usually 1 to 30 parts by weight, preferably 1 part by weight per 100 parts by weight of fluororubber.
~20 parts by weight. When an amine compound is added as desired, it is blended so that the total sum of the aminosilane compound and the amine compound takes the above value. In this case, the molar ratio of the aminosilane compound to the amine compound is selected from the range of 1:99 to 90:10.

As the acid acceptor, those commonly used in the vulcanization of fluororubber can be similarly used, such as one or more divalent metal oxides or hydroxides. Specific examples include oxides or hydroxides of magnesium, calcium, zinc, lead, and the like. Further, as the filler, silica, clay, diatomaceous earth, talc, carbon, etc. are used.

The fluororubber paint according to the present invention is applied or impregnated onto a base material by a normal coating method (brushing, dipping, spraying, etc.) under a temperature condition of room temperature to 400°C, preferably 100 to 400°C. By curing for 10 minutes or more, the desired fluororubber coating can be obtained.

The film thickness of the fluororubber paint according to the present invention is 10~
It is preferable that the film thickness be between 100 microns.If the film thickness is less than 10 microns, there is a risk that the entire surface of the synthetic rubber body will be uneven and some areas will not be coated, while if the film thickness is 100 microns or more, the synthetic rubber The most preferable film thickness is 10 because there is a risk that the film of the fluoro rubber paint applied to the rubber body may crack or it may be difficult to form a uniform film.
~50 microns. The fluororubber coating film of the present invention thus obtained has the properties inherent to fluororubber, and at the same time has excellent adhesion to the synthetic rubber body and its own mechanical properties. Provides non-stick and lubricity.

Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings.

In the manual butterfly valve shown in Fig. 1,
1 has one side facing the inflow part 1a and the other side facing the outflow part 2b, and has a through hole 1d in the center, and the through hole 1d
2 is a valve that freely opens and closes a through hole 1d of the main body; 3 is a valve shaft fixed in the diametrical direction of the valve 2 and protrudes from the valve 2; Both ends are rotatably connected to the valve body 1. Reference numeral 4 denotes a handle provided on the valve shaft, and when the handle is rotated, the valve 2 rotating together with the valve shaft opens and closes the through hole 1d of the valve body 1. That is, when the valve rotates and its outer periphery comes into close contact with the valve seat 1c of the valve body, the valve closes the through hole 1d, while when the valve rotates outward and its outer periphery separates from the valve body 1, the valve closes the through hole. 1d is opened to communicate the inflow portion 1a and the outflow portion 1b on both sides. 5 is an annular groove provided on the inner surface of the valve 2; 6;
is an O-ring fitted into the concave groove 5, and the O-ring 6 rotates in the outward and outward directions together with the valve 2, so that when the valve 2 is in the closed position, the entire outer circumference of the O-ring 6 touches the valve of the valve body 1. While the O-ring 6 is in close contact with the seat 1c to seal between the valve 2 and the valve body 1 to perform a so-called sealing action, the O-ring 6 is released from the valve seat 1c of the valve body 1 when the valve 2 is in the open position. The O-ring 6 is constructed by coating and curing a fluoro-rubber paint containing fluoro-rubber, fluoro-resin, aminosilane compound, amine compound and liquid carrier in a film thickness of 30 microns on the surface of a ring-shaped synthetic rubber body. do. That is, the above-mentioned fluororubber paint was obtained by mixing the following liquids A and B in a ratio of 5 parts of liquid B to 100 parts (by weight) of liquid A.

A Liquid fluororubber (Note 1) aqueous dispersion (fluororubber content: 60% by weight, including nonionic HS-208) ...166 parts fluororesin (Note 2) aqueous dispersion (as fluororesin) FEP content 50% by weight, including Nonion HS-208) ...150 parts Magnesium oxide ...3 parts Medium thermal carbon ...20 parts Nonion HS-210 (manufactured by NOF Corporation) ...2 parts Water ...50 parts Note 1) Vinylidene fluoride/tetrafluoroethylene/hexafluoropropylene elastomeric copolymer (hereinafter simply referred to as fluororubber) Note 2) Tetrafluoroethylene/hexafluoropropylene copolymer (hereinafter referred to as FEP).

B Solution A-1100...40 parts V-11...20 parts Water...40 parts Fluorine rubber obtained by uniformly mixing Solutions A and B in this way and then refining them separately using a 200-mesh wire mesh. The paint was applied to the surface of the synthetic rubber body by spray painting: nozzle diameter 0.8 mm: spray pressure 3.0
kg/ ^cm2 . As a result, a smooth coating film with a thickness of approximately 30 microns was obtained without any abnormalities in the spray coating.

The O-ring 6 constructed as described above is assembled into the groove 5 of the valve 2 to complete a manual butterfly valve. As an indication of the stickiness of the O-ring 6 incorporated into the manual butterfly valve, the second
As shown in the figure, when the contact angle of the seal ring of the present invention with respect to water droplets was measured, it was 110° (Figure 2 A).
Therefore, the water contact angle of the conventional seal ring made only of fluorocarbon rubber is 76° (Figure 2 B), which is larger, and the non-adhesive property of the present invention is much better.
In other words, it can be seen that the sealing ring of the present invention does not easily stick to the valve seat, can easily move together with the valve, and can reliably open and close the valve. Therefore, with a simple structure, troubles such as opening/closing malfunction can be prevented.

[Brief explanation of drawings]

Figures 1A and 2B are a plan view and a sectional view of a manual butterfly valve equipped with a sealing ring as an embodiment of the present invention, and Figures 2A and 2B are the water contact angle of the sealing ring shown in Figure 1. FIG. 1... Valve body, 2... Valve, 3... Valve shaft, 4...
Handle, 5...concave groove, 6...O ring.

Claims (1)

[Scope of Claims] 1. When the opening/closing member of the opening/closing device is in pressure contact with the fixed member to close, the opening/closing member is interposed between the two members to seal the space between them, while when the opening/closing member is separated from the fixed member to open, either one of the members is A seal ring for a vacuum butterfly valve that is separated from the other member along with the other member, and a fluororubber paint comprising fluororubber, fluororesin, an aminosilane compound, and a liquid carrier, coated on the surface of a synthetic rubber body. Seal ring for opening/closing devices made by coating and curing. 2. The seal ring according to claim 1, wherein the weight ratio of the fluororubber and fluororesin is
A seal ring for sealing a switchgear, characterized by a ratio of 95:5 to 35:65. 3. A seal ring for a switchgear according to claim 1, characterized in that the fluororubber coating is coated with a film thickness of 10 to 100 microns. 4. The seal ring according to claim 1, wherein the opening/closing member is an opening/closing valve, the fixing member is a valve body, and the seal ring is an O-ring provided in a groove of the opening/closing valve. Seal ring for sealing switchgear. 5. The seal ring according to claim 1, characterized in that the fluororubber paint contains an aminosilane compound in an amount of 1 to 30 parts by weight per 100 parts by weight of fluororubber. Seal ring for sealing switchgear. 6. A seal ring for sealing a switchgear according to claim 1 or 3, wherein the fluororubber paint further contains an amine compound. 7. The seal ring according to claim 1 or 4, wherein the fluororubber paint contains an amine compound having at least two terminal amino groups. Seal ring for sealing the device. 8. A seal ring according to claim 4 or 5 for sealing a switchgear, characterized in that the molar ratio of the aminosilane compound to the amine compound is 1:99 to 90:10. Seal ring. 9. The seal ring according to claim 1, wherein the fluororubber paint contains an inorganic fibrous substance. 10 In the seal ring according to claim 7, the inorganic fibrous substance contained in the fluororubber paint is selected from the group consisting of glass fiber, carbon fiber, asbestos fiber, and potassium titanate fiber. A seal ring for sealing a switchgear, characterized in that: