JPS6121134B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for manufacturing a rubber hose having a thin synthetic resin layer on its inner surface. More specifically, the present invention provides an oil-resistant and weather-resistant rubber material layer with a polyvinyl chloride resin layer or a polyamide resin layer on the inner surface of a rubber hose made of a rubber material layer of resorcinol, formalin, and acrylonitrile butadiene rubber (hereinafter referred to as NBR).
The present invention relates to a method for producing a rubber hose, characterized in that the rubber hose is vulcanized and bonded using a solution prepared by dissolving the rubber hose in a ketone solvent having a high water content as an adhesive. The rubber platform according to the present invention is particularly suitable for use in automotive fuel hoses, lubricating oil hoses, and the like. In recent years, fuel circuit system hoses, especially automotive fuel hoses that are applied to fuel circuit systems equipped with electronic fuel injection devices, have become more expensive because the gasoline flowing inside them tends to deteriorate as the engine's high temperature and internal pressure increase. , sour gasoline resistance is required. In addition, in recent years, alcohol has been added to gasoline for fuel hoses based on the fuel situation, or alcohol-resistant fuel oil has already been put into practical use in countries such as Brazil and the United States. It is also required to have high durability and alcohol resistance. Furthermore, this type of rubber hose has come to be required to have various characteristics compared to the past, such as the requirement for improved gasoline permeation resistance due to regulations regarding air pollution and improved fuel ratios. On the other hand, since the oil temperature of lubricating oils such as engine oil and power steering oil is even higher than that of fuel oil, the rubber material of hoses is susceptible to oxidative deterioration, and the peroxy radicals generated are In consideration of the effects on rubber materials of additives such as extreme pressure agents in lubricating oil, etc., the rubber hose materials used are required to have various performances that can withstand these harsh conditions. Polyvinyl chloride resins such as polyvinyl chloride, polyvinyl chloride/vinyl acetate copolymers, and polyamide resins such as polyamide 11 and polyamide 12 have properties such as alcohol-added gasoline resistance, alcohol resistance, gasoline permeation resistance, and resistance. Since they are excellent in properties against degraded gasoline, they may be used as hose materials in the above-mentioned applications, but when using these materials, there are the following problems. In other words, these resin materials are
Although flexibility is ensured by the use of plasticizers,
There are various effects due to the extraction of plasticizer substances with gasoline, such as extraction shrinkage, heat shrinkage due to plasticizer volatilization, and increased rigidity.On the other hand, when no plasticizer is used, it is necessary to ensure flexibility as a hose. The problem with this is that the layer thickness must be reduced. On the other hand, these resins
Since there is a problem of poor heat resistance and weather resistance, a rubber layer with excellent heat resistance and weather resistance is provided on the outside of the thin layer of these polyvinyl chloride resins and polyamide resins to reinforce this. It is considered to do. In this way, when a weather-resistant and oil-resistant rubber layer is provided on the outside of a thin layer of polyvinyl chloride resin or polyamide resin, if the adhesion between the layers is weak, peeling between the resin layers may occur. , there is a risk of deterioration of durability. Various types of adhesives are used to improve the adhesiveness between resin layers, but when manufacturing such hoses, it is necessary to cover the outside with a rubber layer and then vulcanize it, and the adhesive is also used during vulcanization. Since a vulcanized adhesive type that adheres at the same time has a strong adhesive force and is preferable, resorcinol/formaldehyde/rubber latex based adhesives, or so-called R/F/L based adhesives, have traditionally been used as this vulcanized adhesive type adhesive. It's here. However, since this R・F・L adhesive is an aqueous solution type when applied on the resin layer,
In the end, sufficient adhesive strength could not be obtained due to poor wetting with the resin layer. The present inventors applied a solution of resorcinol, formalin, and NBR dissolved in a ketone solvent with a high water content as an adhesive to the outer surface of a thin-layer tube made of polyvinyl chloride resin or polyamide resin. This is coated with a partially vulcanized rubber material having oil resistance and weather resistance, and then the thin tube of the above resin and the rubber material layer are vulcanized and bonded to obtain a rubber hose as described above. It has been found that this material has various characteristics currently required. Therefore, the present invention provides a thin tube of polyvinyl chloride resin or polyamide resin on the inner surface of a rubber hose with a rubber material layer having oil resistance and weather resistance.
It is characterized by being vulcanized and bonded using a solution of resorcinol, formalin, and NBR dissolved in a ketone solvent with a high water content as an adhesive.
The present invention provides a rubber hose having a synthetic resin thin layer on the inner surface and a method for manufacturing the same. The present invention will be explained in detail below. The rubber hose obtained by the method of the present invention has an oil-resistant and weather-resistant rubber material layer, a polyvinyl chloride resin layer or a polyamide resin layer on the inner surface, and a special resorcinol, formalin, and NBR mixed solution as an adhesive. Examples of the rubber material layer include epichlorohydrin rubber, chloroprene rubber, hypalon rubber, NBC/PVC blend rubber, and NBR. The above-mentioned resorcinol, formalin, and
NBR mixed solution consists of resorcin and formalin.
This is a solution in which an organic solvent solution of NBR is dissolved in a ketone solvent with a high water content, but resorcin and formalin may be in the form of an initial condensate of resorcin and formaldehyde. In this adhesive, the mixing ratio of resorcinol and formaldehyde is preferably 1:1.5 to 1:15. Also, the mixing ratio of resorcinol/formaldehyde and NBR is 1:
1 to 1:10 is preferred. The solid weight ratio of resorcinol/formaldehyde and NBR is 1:4~
The molar ratio of resorcinol to formaldehyde is preferably in the range of 4:1 to 1:4. Examples of the above-mentioned ketone solvents with high water content include acetone, methyl ethyl ketone, and methyl isobutyl ketone. The above adhesive can usually be prepared using (1) resorcin/formaldehyde initial condensate (2) formalin (3) NBR solution; It may also be prepared using Examples of such cases include (1) 10 parts of resorcinol, (2) 3 parts of formalin (37%), (3) 0.1 part of caustic soda (5%), (4) 40 parts of water, and (5) 1100 parts of NBR15% MEK solution. One example is a MEK solution with a solid content of 10wt% after making an adhesive using it. One embodiment of the production of a rubber hose by the method of the present invention is a thin-layer tube made of a polyvinyl chloride resin such as polyvinyl chloride, a vinyl chloride/vinyl acetate copolymer, or a polyamide resin such as polyamide 11, polyamide 12, etc. Coat the outer surface with the above-mentioned resorcinol/formaldehyde/NBR mixed adhesive, for example, and after drying, apply unvulcanized rubber such as epichlorohydrin rubber, chloroprene rubber, hypalon rubber, etc.
A rubber compound composition such as NBR/PVC blend rubber or NBR is coated using an extruder or the like, and then vulcanized. Examples are listed below, as well as examples in which the interlayer adhesion of rubber hoses obtained by the method of the present invention was measured. Example 1 An adhesive composition as described below is spray applied to the outer surface of a thin-layer tube made of polyamide 11 (Rilsan BESN-O-TL) with an inner diameter of 6φ and an outer diameter of 7φ. (1) Resorcinol/formaldehyde initial condensate
45% acetone solution: (Adver RF: Hodogaya Chemical) resorcin/formaldehyde = 1/1
(mol/mol) (2) Formalin (37%) (3) NBR (JSRN220S manufactured by Japan Synthetic Rubber) 15% methyl ethyl ketone solution Using (1), (2), and (3) above, resorcinol formaldehyde/NBR = 1 /
A solution of 3 (wt/wt) resorcin/formaldehyde=1/2 (mol/mol) was prepared, and then this was made into a 10% methyl ethyl ketone solution. After drying the applied adhesive layer at room temperature for 5 minutes and heat-treating it at 100°C for 3 minutes, an epichlorohydrin rubber compounded composition (unvulcanized) having the formulation shown in Table 1 was applied thereon using an extruder to reduce the outer diameter. 11φ
It was coated so that Next, it was vulcanized in a steam vulcanizer with a steel pressure of 4.5 Kg/cm ² to produce a laminated hose. Table 1 Epichlorohydrin rubber (Zekron 3100: manufactured by Nippon Zeon Co., Ltd.) 100 parts MgO (acid acceptor) 3 CaCO ₃ (acid acceptor) 5 Carbon black 40 Plasticizer 10 Vulcanization aid 1 Vulcanizing agent 1 Example 2 In Example 1, in place of the epichlorohydrin rubber compounded composition shown in Table 1, the NBR/PVC blended rubber compounded composition (unvulcanized) shown in Table 2 below was used, and in the same manner as above, a laminated hose was made. Manufactured. Table 2 NBR/PVC blend rubber 100 parts Carbon black 100 Plasticizer 25 Vulcanization accelerator 5 Vulcanizing agent 0.5 Processing aid 1 Vulcanization accelerator (A) 1.5 Vulcanization accelerator (B) 1.5 Experimental example 1 Example The interlayer adhesion between the rubber material layer and the synthetic resin layer in each laminated hose obtained in 1 and 2 was determined.
Tested according to JISK 6301 test method. The results are shown in Table 3 along with comparative examples.

【table】

[Table] Example 3 The adhesive composition used in Example 1 was sprayed onto the outer surface of a thin-layer tube made of polyvinyl chloride (Nippon Zeon 103EP) with an inner diameter of 6φ and an outer diameter of 7φ, and the adhesive layer was After drying at room temperature for 5 minutes, heat-treat at 100°C for 3 minutes. In addition, in place of the NBR/PVC blend rubber in the formulation shown in Table 2 above, NBR
Except for using rubber, an NBR rubber compounded composition (pre-vulcanized) having the same formulation was coated with an extruder to an outer diameter of 10φ. Next, after blading spun polyester fiber onto it using a blading machine,
After coating and drying the RFL adhesive, an epichlorohydrin rubber compounded composition (unvulcanized) having the formulation shown in Table 1 was coated using an extruder so that the outer diameter was 14φ. Thereafter, it was vulcanized in a steam vulcanizer with a steam pressure of 4.5 Kg/cm ² to produce a laminated hose. Experimental Example 2 The interlayer adhesion between the rubber material layer and the synthetic resin layer in the laminated hose manufactured in Example 3 was tested using the JISK 6301 test method. The results are shown in Table 4 along with comparative examples.

Same as [Table]

Claims (1)

[Claims] 1. A solution of resorcinol, formalin, and NBR dissolved in a ketone solvent with a high water content is applied as an adhesive to the outer surface of a thin-layer tube made of polyvinyl chloride resin or polyamide resin, and then,
This is coated with an unvulcanized rubber material having oil resistance and weather resistance, and then a thin synthetic resin layer is applied to the inner surface by vulcanizing and adhering the thin resin tube and the rubber material layer. A method for manufacturing a rubber hose.