JP2003294147A - Gas seal material and manufacturing method for it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas seal material and a manufacturing method for it which reduce gas permeability, especially carbon dioxide gas permeability. <P>SOLUTION: In this gas seal material, a polyamide film layer is arranged between a first rubber layer and a second rubber layer. This manufacturing method for the gas seal material includes a process of putting the polyamide film layer between the first rubber layer and the second rubber layer. After the surface of the polyamide film layer is treated with a resorcin folmalin latex solution, the polyamide film layer is put between the first rubber layer and the second rubber layer. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas sealing material and a manufacturing method thereof, and more particularly to a gas sealing material capable of reducing gas permeability, particularly carbon dioxide gas permeability, and a manufacturing method thereof.

[0002]

2. Description of the Related Art The refrigerant currently used as a refrigerant for compressors of air conditioners and refrigerators is Freon R-13.
4a (1,1,1,2-tetrafluoroethane) is the mainstream. However, its use is planned to be prohibited in the future due to the problems of ozone layer depletion and environmental destruction such as global warming.
Hydrocarbon-based gas and carbon dioxide are receiving attention as alternatives to this refrigerant, but since hydrocarbon-based gas has a high risk of explosion and combustion, carbon dioxide will be used as the next-generation refrigerant particularly in the future. It is considered to be one.

Currently, hydrogenated NBR, EPDM, etc. are used as materials for gas sealing materials, but these materials are not suitable as carbon dioxide sealing materials because of their high compatibility with carbon dioxide gas. is there.

In order to solve such a problem, there is a method of reducing the carbon dioxide gas permeability by mixing a material having low carbon dioxide gas permeability into hydrogenated NBR or EPDM. However, materials with low carbon dioxide permeability are generally hydrogenated NB.
There is a problem of poor compatibility with R or EPDM.

There is also a method of using a vinylidene fluoride resin, which is a material having low carbon dioxide gas permeability, as the sealing material. However, since the vinylidene fluoride resin is inferior in workability and flexibility as compared with the rubber material, there is a problem that the deformation followability is poor and the sealing medium leaks.

Further, Japanese Patent Application Laid-Open No. 2001-208201 discloses a technique using a packing made of polyamide resin. However, even in this technology, since the polyamide resin itself, which has a high elastic modulus, is used as the material, the deformation followability corresponding to the roughness of the inner surface of the gas flow path port is poor and the sealing property is not sufficient. The gas may leak through the gap between the inner surface of the gas flow path and the inner surface of the gas flow path.

[0007]

In view of the above circumstances, it is an object of the present invention to provide a gas sealant capable of reducing gas permeability, particularly carbon dioxide gas permeability, and a method for producing the same. .

[0008]

In order to achieve the above object, the present invention provides a gas sealing material in which a polyamide film layer is provided between a first rubber layer and a second rubber layer. Characterize.

In the gas sealing material of the present invention, the thickness of the polyamide film layer is 10 to 200 μm.
Is preferred.

The gas sealing material of the present invention is an O-ring having a circular or elliptical cross section, and a polyamide film layer is provided at a position deviating from the equatorial plane substantially parallel to the equatorial plane. Preferably.

The present invention also relates to a method for producing a gas sealing material, which includes a step of sandwiching a polyamide film layer between a first rubber layer and a second rubber layer.

Further, according to the present invention, the polyamide film layer is provided with a resorcinol formalin latex solution (RFL solution).
The present invention relates to a method for manufacturing a gas sealing material, which includes a step of sandwiching a polyamide film layer between a first rubber layer and a second rubber layer after surface treatment by.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below.

(Polyamide film layer) The material used as the main material of the polyamide film layer is, for example, nylon 6, nylon 66, nylon 610, nylon 11, nylon 12 or nylon 46.
Among them, nylon 6, nylon 66, nylon 61
It is preferable to use at least one material selected from the group consisting of 0, nylon 11 and nylon 12. Since these materials have high gas barrier properties, especially gas barrier properties against carbon dioxide gas, when these materials are installed in the rubber layer, gas permeability, particularly carbon dioxide gas permeability, can be further reduced. Furthermore, since these materials have excellent adhesiveness to the rubber material and can flexibly follow the deformation of the gas sealing material, the film layer does not peel off from the rubber material.

The thickness of the polyamide film layer is
It is preferably 10 to 200 μm, and 20 to 100
More preferably, it is μm. In this case, both gas permeability and manufacturing cost can be reduced.

When the gas sealing material of the present invention is an O-ring having a circular or elliptical cross section, a polyamide film layer is placed at a position deviating from the equatorial plane substantially parallel to the equatorial plane. Is preferably provided. Here, the "equatorial plane" is, for example, as shown in FIG. 1, a plane (AA ', where the centers a and b of a circle or an ellipse of an O-ring cross section are connected by a straight line, and cut along the extension line of the straight line. BB ')
And Further, “substantially” means that the inclination of the polyamide-based film layer with respect to the equatorial plane is ± 5 ° or less.

When the polyamide film layer is thus placed in the rubber layer, for example, as shown in FIG. 2, the contact layer 2 between the inner surface of the gas flow path port 4 and the equatorial plane is made of an elastic material. Since the polyamide-based film layer 3 can reduce the gas permeability, the sealing property between the gas sealing material 1 and the inner surface of the gas flow path port 4 is improved, so that the gas sealing material is improved. It becomes more difficult for gas to leak from the gap between the gas passage 1 and the gas passage port 4.

In this case, the distance d from the equatorial plane to the surface of the polyamide film layer 3 and the gas sealing material 1
The ratio d / D to D, which is half the thickness of, is 1/10.
˜2 / 3, preferably 1/10 to 1/3, more preferably 1/10 to 1/4. When the polyamide-based film layer 3 is installed in this way, the gas barrier property and the sealing property are well balanced, and the gas permeability can be further reduced.

(First Rubber Layer, Second Rubber Layer) For the first rubber layer and the second rubber layer, a rubber composition having the same composition or a different rubber composition can be used.

The main material of the rubber composition used in the first rubber layer and the second rubber layer is not particularly limited, and for example, acrylonitrile-butadiene rubber (NBR), which is generally used as a gas sealing material, Ethylene-propylene-diene terpolymer rubber (EPDM), fluororubber (FKM), styrene-butadiene rubber (SBR), silicone rubber (Q), epichlorohydrin rubber (CO)
1 or more types can be used.

The rubber composition may further contain additives. Examples of the additive include a cross-linking agent, a vulcanization accelerator, a vulcanization acceleration aid, a filler, a plasticizer, a softener, a lubricant or an antiaging agent. Examples of the cross-linking agent include benzoyl peroxide, dicumyl peroxide, di-t-butyl peroxide, t-butyl cumyl peroxide, methyl ethyl ketone peroxide, cumene hydroperoxide, 2,5-dimethyl-2,5-
There are organic peroxides such as di (t-butylperoxy) hexane and sulfur. Examples of the vulcanization accelerator include thiazole-based, sulfenamide-based, dithioate-based, thiuram-based, thiourea-based or guanidine-based vulcanization accelerators. Examples of the vulcanization acceleration aid include zinc white, stearic acid and the like.

Examples of the filler include carbon black, calcium carbonate, magnesium carbonate, clay, talc, alumina and calcium sulfate. Examples of the plasticizer include dimethyl phthalate, diethyl phthalate, di-2-ethylhexyl adipate, di-n-decyl adipate, tributyl phosphate and the like. Also,
Examples of the softening agent include petroleum-based softening agents such as process oil and liquid paraffin, and fatty oil-based softening agents such as castor oil and rapeseed oil. Examples of the lubricant include hydrocarbon-based, ester-based, fatty acid-based or fatty acid amide-based lubricants. Examples of the antioxidants include amine-based, phenol-based, imidazole-based, metal carbamic acid salts, waxes and the like.

(Manufacturing Method) The gas sealing material of the present invention is
It is manufactured by sandwiching a polyamide film layer between the first rubber layer and the second rubber layer. As a method of manufacturing the gas sealing material of the present invention, for example, there is a method of vulcanizing and molding a first rubber layer and a second rubber layer, and then sandwiching a polyamide film layer therebetween. For example, when producing an O-ring using the gas sealing material of the present invention, as shown in FIG.
By sandwiching the O-shaped polyamide film layer 13 between the second rubber layer 6 and these layers and adhering these layers, the gas sealing material 11 can be produced. Also,
As shown in FIG. 4, the first rubber layer 15 formed in a rectangular parallelepiped shape
And the second rubber layer 16 between the polyamide-based film layer 23
It is also possible to bond these layers with sandwiching between them and then punch them out into an O shape to produce the gas sealing material 21.

In addition to the above-mentioned manufacturing method, as a method for manufacturing the gas sealing material of the present invention, for example, after a polyamide film layer is sandwiched between an unvulcanized first rubber layer and a second rubber layer. There is also a method of vulcanization.

As a method of disposing the polyamide film layer at a position deviating from the equatorial plane substantially parallel to the equatorial plane, for example, after vulcanization molding by changing the thickness of the first rubber layer and the second rubber layer, There is a method of sandwiching a polyamide-based film layer between them, or a method of sandwiching a polyamide-based film layer between a first rubber layer and a second rubber layer having different thicknesses formed in a rectangular parallelepiped and then punching the same. .

The first rubber layer, the second rubber layer and the polyamide film layer are adhered to each other. As a bonding method, for example, a method of physically bonding by an anchor effect after providing irregularities on the surface of the polyamide-based film layer by etching or the like, a method of chemically bonding the rubber layer and the polyamide-based film layer, or the above There is a method of adhering the rubber layer and the polyamide film layer with an adhesive. here,
As the adhesive, for example, ester-based and ether-based adhesives are preferably used.

The polyamide film layer is preferably surface-treated with a resorcinol formalin latex solution (RFL solution). In this case, the adhesion between the polyamide film layer and the rubber layer becomes strong. As the surface treatment method, for example, the polyamide-based film layer is dipped in an RFL solution, and R on the polyamide-based film layer.
After applying the FL solution and the like, there is a method of drying and the like.

(Use) The gas sealing material of the present invention is molded into, for example, O type, U type, V type, X type, S type, L type, etc., and is used for O rings, gaskets, packings, metal pipe joints. It is used for pipes, hoses, tapes such as bellows or masking tapes for sealing, and sheets. Also,
These gas sealing materials of the present invention are, for example, air conditioners,
It is preferably used for a cooling system such as a car air conditioner and a refrigerator and a heating system such as a heat pump water heater.

[0029]

EXAMPLES The present invention will be described in more detail with reference to examples below, but the present invention is not limited thereto.

(1) Preparation of Samples Table 1 below shows the formulations of the samples of Examples 1 and 2 and Comparative Example 1. The samples of Examples 1 and 2 and Comparative Example 1 were prepared as follows. First, the rubber materials are weighed so as to have the composition shown in Table 1, and then these materials are mixed. Next, this mixture is master-kneaded with a Banbury mixer, and then finally kneaded with an open roll to form an unvulcanized rubber into an O-ring shape. Next, the unvulcanized rubber formed into the O-ring shape is divided into two. Finally, a nylon film having the specifications shown in Table 1 was surface-treated with an RFL solution, sandwiched between the two unvulcanized rubbers, and vulcanized at 170 ° C. for 20 minutes.
2 and the samples of Comparative Example 1 were prepared. The sample of Example 1 has a distance d from the equatorial plane to the nylon film surface.
And the ratio d / D, which is half the thickness of the sample, is 1 /
It was manufactured so as to be 4. The sample of Example 2 was manufactured so that the ratio d / D was 1/3.

(2) Gas Permeability Evaluation Method The gas permeability of the samples of Examples 1 and 2 and Comparative Example 1 was evaluated by the rubber cloth / plastic cloth test method-Part 10:
The gas permeability was measured according to K6404-10 (1999). The outline of the measurement will be described below. First, place a sample between two bahts of a measurement cell that is airtightly sealed, and expose one surface of the sample to carbon dioxide gas at a constant pressure, while at the same time introduce a carrier gas into the cell on the other surface at a constant rate. Contact the sink sample. Next, the concentration of carbon dioxide gas in the carrier gas is measured by an analyzer provided at the outlet of the cell, and the transmittance of carbon dioxide gas in the sample is measured from the result. The measurement results are shown in Table 1. Here, the measurement result of gas permeability is shown in Comparative Example 1
Is shown as a relative value when the gas permeability of 100 is set to 100, and the smaller the value is, the lower the permeability of carbon dioxide gas is.

[0032]

[Table 1]

(Note 1) NBR manufactured by Nippon Zeon Co., Ltd. (Note 2) ISAF N220. (Note 3) Cyclohexyl benzothiazyl sulfenamide manufactured by Ouchi Shinko Chemical Co., Ltd. (Note 4) Zinc dibenzyldithiocarbamate manufactured by Ouchi Shinko Chemical Co., Ltd. (Note 5) Nylon film manufactured by Toray Synthetic Film Co., Ltd.

(3) Evaluation Results As shown in Table 1, the samples of Examples 1 and 2 were able to reduce the gas permeability more than the sample of Comparative Example 1. Also,
The ratio d / D of the distance d from the equatorial plane to the nylon film surface and D, which is half the thickness of the gas sealing material, is 1
The sample of Example 1 having a ratio of / 4 tended to be able to further reduce the gas permeability more than the sample of Example 2 having a ratio d / D of 1/3.

The embodiments and examples disclosed this time are to be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description but by the claims, and is intended to include meanings equivalent to the claims and all modifications within the scope.

[0036]

As described above, according to the present invention, it is possible to provide a gas sealing material capable of reducing gas permeability, particularly carbon dioxide gas permeability, and a method for producing the same.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of an example of an O-ring that is an aspect of the gas sealing material of the present invention.

FIG. 2 is a schematic cross-sectional view showing the relationship between an example of the gas sealing material of the present invention and a gas passage opening.

FIG. 3 is a schematic enlarged view showing an example of a method for manufacturing a gas sealing material of the present invention.

FIG. 4 is a schematic conceptual view showing an example of a method for manufacturing a gas sealing material of the present invention.

[Explanation of symbols]

1,11,21 Gas sealant, 2 contacts, 3,13,2
3 Polyamide-based film, 4 gas flow port, 5,15
First rubber layer, 6,16 Second rubber layer.

Continued front page    F-term (reference) 3J040 BA02 EA15 FA05                 4F100 AK27 AK29 AK46B AK48                       AK73 AK75 AL01 AN00A                       AN00C AN02 AT00B BA03                       BA06 BA10A BA10C BA13                       DA11 EH012 EJ641 JA20B                       JD02 YY00B

Claims (5)

[Claims] 1. A sealing material for gas, wherein a polyamide film layer is provided between the first rubber layer and the second rubber layer. 2. The thickness of the polyamide film layer is 10 to 10.
The sealing material for gas according to claim 1, which has a thickness of 200 μm. 3. An O-ring having a circular or elliptical cross section, wherein a polyamide-based film layer is provided at a position deviating from the equatorial plane substantially parallel to the equatorial plane. The sealing material for gas according to 1 or 2. 4. A method of manufacturing a gas sealing material, comprising a step of sandwiching a polyamide film layer between a first rubber layer and a second rubber layer. 5. A gas seal, comprising a step of sandwiching the polyamide film layer between a first rubber layer and a second rubber layer after surface-treating the polyamide film layer with a resorcinol formalin latex solution. Method of manufacturing wood.