JPS58187688A - Method of bonding hose mouth piece and fluorine rubber hose - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for joining a fluororubber hose to a hose cap, which is applied to fuel system and lubricating system hoses that particularly require high-pressure sealing performance.

Conventionally, for hoses that require high-pressure sealing properties, an insert fitting with an outer diameter larger than the inner diameter of the hose is inserted into the hose, and the outer fitting is caulked against the insert fitting from the outside to maintain constant compression at the end of the hose. This ensured sealing performance.

that time. For the purpose of improving insertion workability and preventing damage to the inner rubber of the hose. Surfactant. Insertion aids such as mineral oils are used for lubrication purposes. As a result, the insertion workability is good, and the insertion aid remains present at the interface between the insert fitting and the inner rubber of the hose. It may cause the rubber to deteriorate. In addition, it corrodes the insert metal fittings and has a negative impact on the equipment. There was a problem that the adhesion between the insert fitting and the hose was small and the sealing performance was poor, but this was done with the aim of improving the sealing performance. There are known methods such as providing a rubber elastic adhesion layer on the insert fitting, or providing an adhesive layer on the insert fitting and bonding the insert fitting and the hose.In either method, the insert fitting alone 69. This requires much greater insertion force than when inserting a hose, making it difficult for regular nurses to insert. Also, if you insert it forcibly, it will damage or tear off the inner rubber of the hose and the rubber elastic adhesion layer or adhesive layer on the insert fitting, which will have a negative effect on the sealing performance, so it is necessary to use an insertion aid as mentioned above. II. In a method of providing an adhesive layer on the metal insert, which is effective for the above-mentioned sealing property F.

In order to prevent the adhesive layer from being removed when inserting the metal insert, some measures have been taken, such as using a semi-vulcanized core, but this still causes the problems described above due to the use of insertion aids. This is particularly noticeable in the case of fluororubber hoses, which have poor adhesion to insert fittings.
The reality is that solving these problems has become a serious issue.

The present invention was invented in view of the above circumstances, and acts as a lubricant and surface cleaner when inserted, and after insertion, it migrates to the adhesive layer on the insert fitting and inside the hose, and also acts as a lubricant and surface cleaner. The object of the present invention is to find an insertion aid that does not cause any adverse effects such as deterioration or corrosion of the insert fittings, and does not inhibit the adhesion between the insert fittings and the hose. The main point is to provide a fluororubber hose that can be applied to hoses.

Apply an adhesive containing fluororubber to the outer circumferential surface of the insert fitting of the hose fitting, and let it dry.

After forming an adhesive layer by semi-vulcanizing.

A fluorine-containing lubricating oil that functions as an insertion aid and a surface cleaner, does not cause rubber deterioration or corrosion of the insert fittings, and does not inhibit the adhesion between the insert fittings and the hose is applied to the outer peripheral surface of the adhesive layer. Or, by applying the fluorine-containing thread lubricating oil to the semi-vulcanized adhesive layer applied to the outer circumferential surface of the insert fitting, the fluorine rubber hose can be It is easy to insert and insert the
Through subsequent vulcanization, the fluorine-containing lubricating oil migrates and penetrates into the fluororubber hose and adhesive layer, so it will not remain at this interface for any length of time, and will no longer interfere with adhesion, providing good sealing performance. It is.

1. The function as a surface cleaning agent is to clean and remove mold release agents etc. that adhere to the inner surface of the hose during manufacture.

This means that it also prevents adhesion inhibition.

The composition of the adhesive for forming the adhesive layer in the present invention is preferably one containing fluororubber, and the auxiliary materials to be mixed include a vulcanizing agent such as peroxide, an amine compound, a polyol compound, and water. There are vulcanization accelerators such as calcium oxide and magnesium oxide, and reinforcing agents such as car pump hooks are used if necessary.

That is, carbon black not only has a reinforcing effect in terms of the strength of the adhesive layer (strength against peeling off when the hose is inserted), but also has the property of adsorbing /II lubricating oil, so it is actually preferable to include it.

As the fluororubber applied to the adhesive, vinylidene fluoride-propylene hexafluoride [i combination, vinylidene fluoride-glopylene hexafluoride-ethylene tetrafluoride terpolymer, etc. are used.

Further, the adhesive is used in the form of a solution prepared with an arbitrary nonvolatile content concentration (preferably 10. to 30% by weight from the viewpoint of workability, etc.) with an organic solvent.

The organic solvent is not particularly limited as long as it is a solvent that dissolves fluororubber, but methyl ethyl ketone can be used.

Ketone thread solvents such as methyl isobutyl ketone, halogen-containing solvents such as trifluorochloroethylene, and mixed solvents thereof are used.

The fluorine-containing lubricating oil used in the present invention includes:
Any lubricating oil containing fluorine will suffice.

These fluorine-containing lubricating oils have excellent heat resistance, chemical resistance, and good oil properties.
C), and from the viewpoint of workability etc., it is practically preferable to have a viscosity of 5 to 500 centistokes and an average molecular weight of 500 to 1,000.

However, it is also possible to use a highly viscous product after diluting it with a diluent that does not inhibit adhesion.

In addition, if the thickness of the fitting layer is too thin, it may not conform well to the surface roughness of the insert fitting, or the unevenness of the inner surface of the hose, or it may tear and peel off when the hose is inserted. It is difficult to apply it thickly.

The thickness is preferably from 20 to 150μ, since problems such as insufficient drying of the solvent and other problems may occur, such as adverse effects on adhesion.

Furthermore, the reason why a fluororubber compound is included in the adhesive composition is that fluororubber cannot be co-vulcanized with other rubbers and cannot withstand fuel oils such as gasoline unless it is fluorine. The vulcanized state refers to a state in which the rubber composition is fluidized at room temperature and vulcanization is in progress. In a semi-vulcanized state, the adhesive layer is harder than in an unvulcanized state, and does not undergo immediate plastic deformation under pressure, so vulcanization can be completed after caulking the outer metal fitting of the two caps to the insert metal fitting. The outer metal fittings may be caulked after sulfurizing.

Note that adhesives containing fluororubber can also be applied to the inner peripheral surface of the fluororubber hose, and in this case, the fluorine-containing thread lubricant can be applied to the outer peripheral surface of the adhesive layer and the insert inserted. It can also be applied to any of the outer peripheral surfaces of the metal fittings.

Further, the outer circumferential surface of the metal insert is pretreated for adhesion, and a primer for metals is usually used.

Hereinafter, the present invention will be specifically explained with reference to Examples.

The adhesive on the outer circumference of the hose cap insert fitting (cylindrical body with an inner diameter of 61 m and an outer diameter of 8 mm) made of iron and plated with zinc and chrome on the surface was treated with di-nobu at room temperature and then dried. After that, heat treatment 1 at 160℃ x 30 minutes
to form a semi-vulcanized adhesive layer. Furthermore, lubricating oil was applied to the surface of the adhesive layer, and an insert metal was attached to a fluororubber hose (inner diameter 7 mm, outer diameter 13.6 m, between the inner layer made of a fluororubber compound and the outer layer made of an epichloro V hydrin compound). (consisting of vinylon glue d↓ reinforcing layer) (fitting length 1l-t2ffi'll, outer metal fitting (cylindrical body with inner diameter 14m and outer diameter 16m) on the outer periphery)
The diameter was reduced to 1896, the hose cap and the fluororubber hose were combined, and the hose cap and the fluororubber hose were bonded together by heat treatment for 15Q'CX ('iQ).

The evaluation methods and evaluation results (Table 1) for insertability and sealability when various lubricating oils are applied are shown below.

〔Evaluation methods〕

(1) Insertion property The force (insertion force; hours) required when inserting a fluororubber hose (length 8 es) into an insert fitting was measured using an autograph.

(2.Sealability) Close one end of the insert fitting that protrudes from the rubber hose, place the joint between the hose cap and the rubber hose in water, send nitrogen gas from the other end of the rubber hose, and check the gas pressure when air bubbles form in the water near the fitting. (Kg/-J) was measured to examine the sealing performance (airtightness) between the hose cap and the rubber hose.

Measurements were performed on two pits at the initial stage (before heat aging) and after heat aging (120°C x 288 hours).

The composition used for the inner layer of the fluororubber hose is as follows. Parts below refer to parts by weight.

Fluororubber 100 parts Carbon black 30 parts 0a (OH) 25 parts Mg0 3 parts Vulcanizing agent 2.5 parts Total 140.5 parts The adhesive for forming the adhesive layer is 1% by weight of the following composition.
methyl ethyl ketone solution.

Dilag treatment was performed several times so that the thickness of the adhesive layer was 60μ. Fluororubber* 100 parts *Product name: Vitonm Carbon Blank 20 parts Mg0 15 parts **Toad Product name: Di
aK total 137.7 parts Table-1 Performance evaluation results *2; Unit c st (centistokes), measurement temperature 25°C *3; Unit CP (centipoise), 721! I Constant temperature: 25° C.*4: During insertion, a considerable portion of the adhesive layer A was peeled off.

In the above Examples and Comparative Examples, the lubricating oil was
] Gold Inser I - The case where it was applied to the adhesive layer on the cargo fittings was shown. 1. Effects of the present invention The same applies when applied to both rubber hoses.

patent developer

Claims (1)

[Claims] Apply an adhesive containing fluororubber to the outer circumferential surface of the hose cap insert. Dry. After semi-vulcanizing to form an adhesive layer. A method for adhering a hose cap and a fluororubber hose, comprising applying fluorine-containing lubricating oil to either the outer peripheral surface of the adhesive layer or the inner peripheral surface of the fluororubber hose, inserting the fluororubber hose, and further vulcanizing.