JPS5861372A - No-stickiness elastic valve - Google Patents

Abstract

PURPOSE:To obtain a valve having elasticity, sealing quality and security preventability, by applying and hardening fluorin rubber paint, contained with fluorin rubber, fluorin resin, aminosilanes and liquid state carrier, to a forcibly contacted surface. CONSTITUTION:Fluorin rubber and fluorin resin are arranged to 95:5-35:65 by weight ratio, and saed resin, having non-adhesiveness itself, is collected to the surface of a fluoring rubber film 3, then the film 3 is held with excellenct non- adhesiveness on its surface without causing the worsening of adhesiveness to the base material and mechanical quality. 1-30pts.wt. aminosilanes compound is added to 100pts.wt. fluorin rubber, and a function as a vulcanizing agent can be obtained, further adhesiveness to the base material can be improved. Water is preferable for the liquid state carrier from workability and the like. Furthermore, the film 3 is contained with aminocompound and inorganic fiber state material, and compression restoring quality of the film and functions as a vulcanizing agent can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a non-adhesive elastic valve, and more specifically to a non-adhesive elastic valve that prevents the valve and valve dust from sticking together due to special opening/closing conditions, and also exhibits good sealing properties due to its elasticity. The present invention relates to a non-adhesive elastic valve that can be widely applied to purposes requiring such properties.

For example, in an engine reed valve, the fuel on the intake side and the exhaust gas on the exhaust side are controlled by the reed valve, but if the valve is left inactive for a long time, the valve and valve dust can become stuck together, causing the valve to become unusable. unable to function properly. Therefore, there is a need for a valve dust tray that is free from such problems and has excellent non-adhesive properties.

In order to meet this requirement, a reed valve has been proposed in which a fluororesin layer is provided between the reed valve and the valve dust receiver (Japanese Utility Model Publication No. 54-45223). When a fluororesin layer is provided behind the reed valve on the reed valve side, it may cause trouble because it sticks to the rubber layer of the valve seat during crimping and operation in a high temperature and high humidity environment. However, it is still not perfect. On the other hand, when a fluororesin layer is provided on the rubber valve seat side, problems may occur due to poor adhesion between the rubber layer and fluororesin layer, or distortion between the two layers during use due to the difference in elastic modulus between rubber and fluororesin. Therefore, peeling between the rubber layer and the fluororesin layer is likely to occur.

As a result of repeated studies to eliminate the drawbacks of the conventional valves described above, the present inventors have found that by providing a coating film obtained from a specific fluororubber paint on the pressure contact surface of the valve, satisfactory elasticity can be maintained. Furthermore, the inventors have discovered that a non-adhesive elastic valve having sufficient sealing properties and anti-sticking properties on its surface can be obtained, and have completed the present invention.

In other words, the gist of the present invention is to provide a non-adhesive material characterized in that a coating film formed by applying and curing a fluororubber paint containing fluororubber, fluororesin, aminosilane and a liquid carrier is provided on a pressure contact surface. Exists in elastic valves.

In the valve of the present invention, the coating film is preferably provided on the valve dust receiver directly or via a rubber layer, and is provided only on the reed valve side. Furthermore, it is also preferable to provide the coating film of the present invention on the valve dust receiver and provide the fluororesin layer of the prior art on the reed valve side.

In addition to the above characteristics, the non-adhesive elastic valve of the present invention has excellent gasoline resistance and gasohol resistance when used, for example, in a reed 2 valve installed on the intake side of an engine, and furthermore, it does not stick. It functions normally, and when used in reed valves installed on the exhaust side, it has excellent heat resistance, NOx resistance, and ozone resistance, and also functions normally without sticking. Show effectiveness. Furthermore, the fluororubber paint used in the present invention has excellent adhesion to the valve body and does not easily peel off from the valve body.

In the present invention, the fluororubber coating film obtained by blending a specific amount of fluororesin can impart excellent non-adhesive properties to the surface without substantially affecting the adhesion to the substrate and mechanical properties. Because the fluororesin, which itself has non-adhesive properties, unexpectedly gathers on the surface of the fluororubber coating, the above-mentioned performance of the fluororesin is maintained without adversely affecting the adhesion to the substrate and the mechanical properties of the coating. It is thought that this is effectively exhibited on the surface of the fluororubber coating.

According to our research, when we measure the fluorine content on the surface of a 50 μm thick coating film cured at 300°C for 30 minutes and on the adhesive surface to the base material using fluorescent X-ray analysis, we find that the former is higher than the latter. It has been confirmed that the ratio of the former to the latter tends to increase as the curing temperature increases.

The fluororubber used in the present invention is a highly fluorinated elastic copolymer, and a particularly preferred fluorocomb is usually 40 to 85 mol % of vinylidene fluoride and at least one copolymerizable copolymer therewith. Mention may be made of elastomeric copolymers with one other fluorine-containing ethylenically unsaturated monomer.

In addition, fluororubber containing iodine in the polymer chain has, for example, 0.001 to 10% by weight, preferably 0.01 to 5% by weight of iodine bonded to the end of the polymer chain,
Fluororubber whose main composition is an elastic copolymer consisting of 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 vinylidene fluoride ( (Refer to Japanese Patent Application Laid-Open No. 52-40543)
It is. Other fluorine-containing ethylenically unsaturated monomers that can be copolymerized with vinylidene fluoride to give an elastic copolymer include hexafluoropropylene, pentafluoropropylene, trifluoroethylene, trifluorochloroethylene, and tetrafluoroethylene. Typical examples include ethylene vinyl fluoride, perfluoro(methyl vinyl ether), perfluoro(ethyl vinyl ether), and perfluoro(furobyl vinyl ether). Particularly desirable fluorine combs are vinylidene fluoride/hexafluoropropylene dielastic copolymers and vinylidene fluoride/tetra2fluoroethylene/hexafluoropropylene ternary elastic copolymers. In addition, the fluororesin used in the present invention includes polytetrafluoroethylene, tetrafluoroethylene, and at least one other ethylenically unsaturated monomer copolymerizable therewith (for example, olefins such as ethylene and propylene, hexafluoroethylene, etc.). Examples include copolymers with fluoropropylene, vinylidene fluoride, chlorotrifluoroethylene, halogenated olefins such as vinyl fluoride, perfluoroalkyl vinyl ethers, etc., polychlorotrifluoroethylene, polyvinylidene fluoride, and the like. Among these, preferred fluororesins are at least one of polytetrafluoroethylene, tetrafluoroethylene and hexafluoropropylene, perfluoromethyl vinyl ether, perfluoroethyl vinyl ether, and perfluorozolobyl vinyl ether (usually 40% of tetrafluoroethylene). It is a copolymer with (containing less than mol%). Furthermore, the aminosilane compound used in the present invention not only functions as a vulcanizing agent for fluororubber, but also greatly contributes to improving the adhesion to the substrate, and can be safely used in liquid media. Typical compounds include r-aminopropyltriethoxysilane (hereinafter referred to as A-1100), N-β-aminoethyl-r-aminopropyltrimethoxysilane, N-(
trimethoxysilylpropyl)ethylenediamine, N-
β-aminoethyl-r-aminopropylmethyldimethoxysilane, γ-ureidopropyltriethoxysilane,
Examples include β-aminoethyl-β-aminoethyl-r-aminopropyltrimethoxysilane.

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. Among these liquid carriers, water is most preferred from the viewpoint of coating workability and not damaging the rubber layer of the base material.

Furthermore, inorganic fibrous substances as other substances contained in the fluororubber coating of the present invention are used to improve the compression recovery properties of the fluororubber coating, and typical examples include glass fiber, carbon fiber, asbestos, etc. Fibers, potassium titanate fibers, etc. can be drilled. It is desirable that this inorganic fibrous substance has an average length of at least 1μ, preferably 1 to 100μ. ) is
It mainly functions as a vulcanizing agent for fluororubber, and together with the aminosilane compounds mentioned above, improves mechanical properties. Typical examples thereof include ethylamine, propylamine, butylamine, benzylamine, allylamine, Monoamines such as n-amylamine and ethanolamine, ethylenediamine, trimethylenediamine, tetramethylenediamine, hexamethylenediamine, 3,9-bis(3-aminopropyl)-2,
Examples include diamines such as 4,8,10-tetraoxaspiro[5,5]undecane (hereinafter referred to as V-11), polyamines such as diethylenetriamine, triethylenetetramine, tetraethylenepentamine, and pentaethylenehexamine. Among these, amine compounds having two or more terminal amino groups are preferred.

To prepare the fluororubber paint of the present invention, pigments, acid acceptors, fillers, etc. are usually added to a mixture of fluororubber, fluororesin, and liquid carrier according to a conventional method, and if necessary,
Additionally, a surfactant may be used. ), the Sendori Todoroki Ichiban Taiba aminosilane compound 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). ) A uniform fluororubber paint can be obtained by thoroughly mixing using a conventional method.

The ratio of fluororubber and fluororesin is 95:5 to 35 by weight.
:65 is desirable; if the proportion of fluororesin is less than the above lower limit, the desired improvement in non-adhesiveness and lubricity will not be sufficient; on the other hand, if it is greater than the above limit 1-11, the desired thickness will be The paint film is not smooth, and cracks and pinholes are likely to occur in the paint film.

The amount of aminosilane compound added is usually 100% of the fluororubber.
The amount is 1 to 30 parts by weight, preferably 1 to 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.), and is applied at a temperature ranging from room temperature to 400°C, preferably from 100 to 4.0°C.
By curing at a temperature of 0° C. for an appropriate time, the desired fluororubber coating can be obtained.

The film thickness of the fluororubber paint according to the present invention is preferably 10 to 300 μm when applied directly to the valve body, and 10 to 100 μm when applied through a rubber layer, and the film thickness is 10 μm. If the film thickness is less than 300 microns, the elasticity will be insufficient, and there is a risk that the entire surface of the valve body may become uneven and some areas may not be coated. The most preferable film thickness is 10 because there is a risk that the paint film will crack or that it will 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, has excellent adhesion to the valve body and its own mechanical properties, and has a non-adhesive surface. will be granted.

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

1, 2, and 3 show cross-sectional views of different aspects of an engine reed valve that is an embodiment of the present invention. In these reed valves, fuel or exhaust gas passing through the valve hole 4 is controlled by the operation of the reed valve 2. The valve body 1 and the reed valve 2 are made of metal and are fixed at one end with a pin 6.

The non-adhesive elastic valve seat according to the present invention is shown in FIGS. 1 and 2.
As shown in the figures, the following liquids A and B are applied to the surface of the valve body 1 either directly or via the rubber valve seat 5 for 100 parts (parts by weight) of liquid A to 5 parts of liquid B. The non-adhesive fluororubber coating film 3 is coated with a fluororubber coating according to the present invention obtained by blending the fluororubber coating in a ratio of 1.0% to 1.0% and then cured.

Liquid A, Note 1) Fluorine comb aqueous dispersion (fluororubber content 60% by weight, including nonionic H5-208)...166 parts Note 2) Fluorine resin aqueous dispersion (contains FEP as a fluororesin) Amount: 5 parts: 150 parts Magnesium oxide: 3 parts Medium thermal carbon: 20 parts Nonion H S-210 (manufactured by NOF Beni): 2 parts water
- Song - 50 parts 2l) Vinylidene fluoride/tetrafluoroethylene/hexafluoropropylene elastic copolymer (hereinafter simply referred to as fluororubber).

Note 2) Tetrafluoroethylene/hexafluoropropylene copolymer (hereinafter referred to as FEP).

B liquid A-1100...40 parts v-11...20 parts Water...
After uniformly mixing 40 parts of liquid A and liquid B, a fluororubber paint obtained by refining each door using a 200-mesh wire mesh was applied to the pressurized surface by spray painting (nozzle diameter: 1
．． As a result, there were no abnormalities in the spray coating, and a smooth coating film with a thickness of about 30 μm was obtained by curing at 300° C. for 15 minutes.

The following pressure contact test was conducted to examine the non-stick properties of each of the obtained bulbs.

That is, each valve was left in the closed state for one week under a load of 5ooy in an atmosphere of 60° C. and 90% relative humidity. Thereafter, when the load was removed, the IJ-Do valve opened easily.

For comparison, a pressure contact test was conducted under the same conditions as above for a reed valve similar to that shown in FIG. 2, except that the fluororubber coating film of the present invention was not provided. As a result, unlike the case of the above embodiment, the reed valve did not open easily. This indicates that the reed valve does not operate properly, causing trouble.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an engine reed valve in which the fluororubber coating film of the present invention is provided directly on the valve seat surface of the valve body;
Fig. 2 is a sectional view of an engine reed valve in which the fluororubber coating film of the present invention is applied to the surface of the reed valve via a rubber seat, and Fig. 3 is a sectional view of an engine reed valve in which the fluororubber coating film of the present invention is applied to the surface of the reed valve on the pressure contact side. FIG. 2 is a sectional view of an engine reed valve provided with a rubber coating. 1... Valve body, 2... Reed valve, 3... Paint film, 4... Valve hole, 5... Rubber Koa seat, 6... Pin. Patent applicant Daikin Industries, Ltd.

Claims (1)

[Claims] 1. A non-adhesive elastic valve characterized in that a coating film formed by applying and curing a fluororubber paint containing fluororubber, fluororesin, aminosilane and a liquid carrier is provided on the pressure contact surface. . 2. The weight ratio of the fluororubber and fluororesin is 95:5 or more
35:65 valve according to claim 1. 3. The valve according to claim 1, wherein the valve is a valve of an intake and exhaust system of an engine. 4. The valve according to claim 1, wherein the fluororubber paint contains an aminosilane compound in a proportion of 1 to 30 parts by weight based on 100 parts by weight of fluororubber. 5.1 The fluororubber paint further contains an amine compound.6 The fluororubber paint further contains an amine compound having at least two terminal amino groups. The valve according to claim 4, comprising: 7. The valve according to claim 5 or 6, wherein the molar ratio of the aminosilane compound to the amine compound is 1=99 to 90:10. 8. The valve according to claim 1, wherein the fluororubber paint contains an inorganic fibrous substance. 9. The inorganic fibrous substance contained in the above fluororubber paint is:
2. The bulb of claim 1, wherein the bulb is selected from the group consisting of glass fibers, carbon fibers, asbestos fibers and potassium titanate fibers. 10. The valve according to claim 1, wherein the liquid carrier contained in the fluororubber paint is water.