JPS6033663B2 - Rubber hose for gasoline circulation pipe connection - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rubber hose for connecting a gasoline circulation pipe, which is used for connecting a metal pipe to a metal pipe connection mainly in the engine room of an automobile.

As shown in FIG. 1, a rubber hose 4 conventionally used for this purpose consists of an inner tube rubber layer 1 having gasoline resistance, a reinforcing layer 2 made of fibers, and an outer tube rubber layer 3 having weather resistance.
It is constructed from a combination of layered materials, and as shown in FIG. 2, it is bent at the connection part, with both ends attached to the outer periphery of the metal pipe 5, and fixed with a fastening band 6. Ta. However, in recent years, the automobile industry has developed significantly.
In particular, due to the increase in pressure and temperature of fuel due to measures against vehicle exhaust,
Inside the engine room, the temperature is above 100 q at the top and -40 q at the bottom.
Automotive fuel system hoses have various types of hoses compared to conventional ones, such as the fact that the temperature changes over a very wide range, from less than Various performances under severe load conditions are required, and conventional rubber hoses having an inner tube rubber layer 1 made of a general-purpose polymer having gasoline resistance can no longer be used.

Against this background, fluororubber (hereinafter abbreviated as FKM) is a material that satisfies the above performance.
KM has poor heat resistance, sour gasoline resistance, etc.

However, FKM has inferior cold resistance and is very expensive compared to shrimp chlorohydrin rubber (hereinafter abbreviated as CHC) used as a hose material, so in practice it is not placed inside the outer tube rubber layer. CH
Development studies have been carried out on a rubber hose consisting of an outer layer made of a compound such as C and an inner layer made of a compound FKM. However, in addition to the above constraints, FKM
The practical applicability of FKM is limited because FKM does not have good adhesion to other rubber materials such as CHC by normal means, and peeling occurs during use, making it difficult to function properly as a hose. There was a problem that it stopped being effective.

The present invention was invented based on the above circumstances, and provides a rubber hose for connecting a gasoline circulation pipe in which a compound of FKM and a compound of CHC are firmly adhered without intervening an intermediate layer. However, the gist is that the inner tube rubber located inside the outer tube rubber layer is made of an outer layer made of a compound of CHC and an FK.
1,8-diazabicyclo[5,4,0]undecene-7 salt of carboxylic acid represented by the following general formula (hereinafter referred to as carboxylic acid DBU salt) This is due to the fact that it has a composition that combines the following:

[R: alkyl group, phenyl group, naphthyl group, etc.] Below,
Further, the present invention will be explained in detail. In the present invention, CHC
And/or the carboxylic acid DBU salt represented by the above general formula to be incorporated into FKM includes naphthoic acid, 2-hydroxynaphthoic acid, sorbic acid, 2-ethylhexylic acid, gallic acid, and p-hydride.

DBU salts of carboxylic acids such as xy-benzoic acid and cinnamic acid are used, especially DBU salts of naphthoic acid and sorbic acid.
I prefer BU salt. The compounding amount is CHC or FKMIO■
0.1 to 5 parts by weight, preferably 0.5 to 5 parts by weight
3 weight is good. If the amount is too small, there will be no effect on adhesion, and if the amount is too large, the interlayer adhesion under normal conditions will be good, but the gasoline resistance will decrease. Also, from the viewpoint of processability, dispersibility, etc., carboxylic acid DBU salt is
It is better to mix it with HC, and the effect on adhesion is also more preferable.

Although the mechanism of action of carboxylic acid DBU salt is not clear,
It is thought that this promotes co-crosslinking at the interface between CHC and FKM.

In the present invention, in order to further strengthen the adhesion between the inner layer (FKM compound) and the outer layer (CHC compound) of the inner tube rubber layer, silica is added to the CHC compound constituting the outer layer. It is also possible to contain a filler.

As the silica-based filler, acidic silica such as Nip Seal VN-3 (trade name; manufactured by Nippon Silica ■) and basic silica such as Carbrex 1120 (trade name; manufactured by Shionogi & Co., Ltd.) are used, but basic silica It is preferable to use CHCIO in an amount of 5 to 8 parts by weight based on the weight of CHCIO.

Examples of the FKM used in the present invention include a vinylidene fluoride-propylene hexafluoride copolymer, a vinylidene fluoride-propylene hexafluoride-ethylene tetrafluoride terpolymer, and the like.

CHC used in the present invention includes epichlorohydrin-ethylene oxide copolymer, epichlorohydrin polymer, and the like.

In the present invention, FKM may contain other known auxiliary materials depending on the purpose, such as crosslinking agents (peroxide compounds, polyol compounds, amine compounds, etc.), crosslinking accelerators, stabilizers, colorants, plasticizers, reinforcing agents, etc. (carbon black, etc.) etc. may be blended.

Also, known crosslinking agents, crosslinking accelerators, stabilizers, plasticizers, fillers (carbon black, etc.), etc. can be similarly blended into the CHC.

FIG. 3 shows one example of application of the present invention, where la is an inner layer made of a compound of FKM, lb is an outer layer made of a compound of CHC, and the inner rubber layer is two layers of la and lb. Consists of a heavy structure.

2 indicates a reinforcing layer similar to the conventional one, and 3 indicates an outer tube rubber layer.

An example of the method for manufacturing the rubber hose of the present invention is to simultaneously extrude two layers of the CHC compound kneaded using a cooling roll and an FKM compound obtained in the same manner using an extruder, or to extrude two layers simultaneously using an extruder. After extruding the outer layer (CHC compound) onto the inner layer (FKM compound layer) using an extruder, a fiber reinforcing layer is formed thereon, and then the outer tube rubber layer is extruded using an extruder and integrated. It is bonded with sulfur. Vulcanization conditions include temperature 145~170oo, time 30~9
■hin is commonly used.

As explained above, the present invention has solved the problem of adhesion between the FKM compound layer and the CHC compound layer, and the fact that the practical application range of FKM can be expanded by this is a great practical benefit. be.

The present invention will be explained in detail in the following examples, in which a carboxylic acid DBU salt is blended into a CHC mixture.

The formulation for forming the FKM formulation used in the following examples is as shown in Table 1 below.

Table 1 [FKM compounding recipe 1] (Parts by weight) *1; Trade name, manufactured by DuPont. The compounding recipe for forming the CHC compound layer is as shown in Table 2 below.

The test piece was made by stacking the FKM compound layer and CHC compound layer each rolled into 2 willow sheets and stacking them together.
It was vulcanized at oo×45 min and the following test was conducted.

Table 3 shows the test results. '1} Adhesion under normal conditions...
...according to JISK 6301 '2} Ganrin bond adhesion... After soaking regular gasoline at room temperature for 72 hours, according to JISK 6301.

Table 1 2 [CHC formulation] (parts by weight) *1: Product name: Hydrin 200 manufactured by Goodrich Table 1 3
<Adhesion test results> Furthermore, the above-mentioned FKM compound and CHC compound were co-extruded as the inner layer and outer layer of the inner tube rubber layer, respectively, and a reinforcing layer made of braided polyester fiber was applied around the outer periphery,
A rubber hose was manufactured by applying an outer tube rubber layer made of a shrimp chlorohydrin rubber compound.

The vulcanization conditions were leaded vulcanization of 16 mm x 6 mm.
The thickness of each layer is 0.5 side for the inner layer, 0.7 side for the outer layer, and 1.2 side for the outer tube rubber layer. The following performance tests were conducted on the rubber hose obtained as described above. Table 4 shows the test results. The numbers of the comparative examples and examples in Table 4 are shown in Table 3 above. The numbers correspond to those of Comparative Examples and Examples. Horsesaw Gasoline Circulation Test One day of lauroyl peroxide and one day of regular gasoline
Create a model sour gasoline dissolved in
A cycling test with 00xloo feeding time was performed.

(Gasoline was replaced every 16 hours) Thereafter, the adhesive force between the inner layer and outer layer of the inner tube rubber layer of the hose was measured. Table 14
Hose performance test results*; Material failure (rubber breakage)

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a subordinate hose, FIG. 2 is a vertical cross-sectional view showing how the hose is used, and FIG. 3 is a cross-sectional view of an embodiment of the hose of the present invention. 1... Inner tube rubber layer, la... Inner layer,
lb...outer layer, 2...reinforcement layer, 3...outer tube rubber layer, 4...rubber hose. Figure 1 Figure 2 Figure 3

Claims (1)

[Scope of Claims] 1. The inner tube rubber layer located inside the outer tube rubber layer is composed of an outer layer made of a compound of epichlorohydrin rubber and an inner layer made of a compound of fluorine rubber, and and/or fluororubber, 1,8-diazabicyclo[5
・4.0] A rubber hose for connecting a gasoline circulation pipe, characterized in that it is composed of a mixture of undecene-7 salt. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [R: alkyl group, phenyl group, naphthyl group, etc.] 2. A rubber hose for connecting a gasoline circulation pipe according to claim 1, which is made by blending epichlorohydrin rubber with a silica filler. . 3. The rubber hose for connecting a gasoline circulation pipe according to claim 2, wherein the silica filler is a basic silica filler. 4 Carboxylic acid 1,8-diazabicyclo[5.4.0
The rubber hose for connecting a gasoline circulation pipe according to claims 1 to 3, wherein 0.1 to 5 parts by weight of undecene-7 salt is blended with respect to 100 parts by weight of epichlorohydrin rubber or fluorine rubber. 5 Carboxylic acid 1,8-diazabicyclo [5,4,0
The rubber hose for connecting a gasoline circulation pipe according to claims 1 to 4, wherein the carboxylic acid of the undecene-7 salt is either naphthoic acid or sorbic acid.