JP2001206986A - Rubber composition for oxygen hose and oxygen hose using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rubber composition for oxygen hose always satisfying JIS K6333: 1999, a combustion test standard for oxygen hose and an oxygen hose using it. SOLUTION: This rubber composition for oxygen hose comprises acrylonitrile- butadiene rubber as a base material. The oxygen hose uses the rubber composition especially using it as an inner tube layer 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to JIS K633.
3: The present invention relates to a rubber composition for an oxygen hose that satisfies the oxygen hose combustion test standard of 1999, and an oxygen hose using the same. Such an oxygen hose is suitably used in the field of gas welding, cutting and related operations, particularly in the field of brazing and metallizing, and at least the above-mentioned JIS K633.
3: has an applicable range defined in 1999.

[0002]

2. Description of the Related Art In recent years, rubber hoses used for fuel systems and hydraulic systems of internal combustion engines have been required to have higher flame retardancy. For this reason, research and development of flame-retardant rubber hoses are underway. For example, when a rubber hose such as a fuel system is disposed in the engine room of an automobile through a high temperature part of the engine, a metal pipe, a metal plate, or the like is required. Is used to protect the rubber hose from high temperatures.

As a technique for solving the problems such as weight increase when a metal tube or a metal plate is used to protect a rubber hose as described above, 5-30 parts of expandable graphite is provided on a protector layer on the outer periphery of the hose. A vehicle hose using the compounded flame-retardant acrylic rubber composition has been proposed (Japanese Patent Publication No. 7-103948).

[0004] Further, diene rubber has a high spontaneous ignition temperature, but is usually used to prevent the ignition temperature of vulcanized rubber from decreasing due to the low spontaneous ignition temperature of a softening agent usually compounded in rubber. AS per 100 parts by weight of diene rubber
A flame-retardant rubber composition containing 10 to 150 parts of a softening agent having an ignition temperature of 410 ° C. or higher as measured according to TM D2155-63 has been proposed (JP-A-9-012780).

[0005]

However, the conventional JIS
Since K6333 did not have a standard ignition temperature,
JIS K633 specified for oxygen hoses this time
3: There is no technology that satisfies the combustion test standard of Annex A (normative) of 1999 (Do not ignite at 360-365 ° C for 2 minutes in a specific device). At present, there is nothing that can be cleared. This is because the test was conducted by focusing on the fact that the conventional evaluation of flame retardancy is difficult to burn in the presence of a flame.

Accordingly, an object of the present invention is to provide JIS K633.
3: An object of the present invention is to provide a rubber composition for an oxygen hose, which always satisfies the oxygen hose combustion test standard of 1999, and an oxygen hose using the same.

[0007]

The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, a rubber composition based on acrylonitrile-butadiene rubber has a plasticizer, a softener,
Furthermore, they have found that they can always satisfy the JIS K6333: 1999 oxygen hose combustion test standard regardless of the presence of carbon black or the like, and have completed the present invention.

That is, the rubber composition for an oxygen hose of the present invention is characterized by using acrylonitrile butadiene rubber as a base material.

Preferably, the acrylonitrile-butadiene rubber is at least 40 parts by weight based on 100 parts by weight of the rubber component. In order not to impair the physical properties of the vulcanized rubber, the composition preferably contains a softening agent and / or a plasticizer, and more preferably 5 parts by weight or more based on 100 parts by weight of the rubber component. Including.

The oxygen hose of the present invention is characterized by using the above rubber composition for an oxygen hose.

The oxygen hose of the present invention comprises an inner tube layer, at least one fiber reinforcing layer wound around the outer periphery of the inner tube layer, and an outer protective layer disposed around the outer periphery of the fiber reinforcing layer. When having the above, the rubber composition for oxygen hose is used for the inner tube layer.

[0012]

Embodiments of the present invention will be described below. The rubber composition for an oxygen hose of the present invention can be blended with one or two or more other rubbers as long as it is based on acrylonitrile butadiene rubber (NBR). In order to obtain the desired flame retardancy, the acrylonitrile-butadiene rubber is preferably used in an amount of 40 parts by weight or more based on 100 parts by weight of the rubber component. Other rubbers include natural rubber (NR), styrene butadiene rubber (SBR), ethylene propylene diene terpolymer rubber (EPDM),
Examples include acrylic rubber (ACM), butadiene rubber (BR), isoprene rubber (IR), chloroprene rubber (CR), and silicone rubber.

The rubber composition for an oxygen hose of the present invention contains a vulcanizing agent, a vulcanization accelerator, an auxiliary vulcanization accelerator, an antioxidant, an antioxidant, a plasticizer and a softener which are generally used in the rubber industry. , A filler and the like can be appropriately compounded. In particular, vulcanization properties,
In order to maintain good low-temperature properties and processability such as extrusion, a plasticizer and / or a softener are added to the rubber component 10 in total.
It is preferable to blend 5 parts by weight or more with respect to 0 parts by weight,
Even with such a blending, it is possible to satisfactorily satisfy the JIS K6333: 1999 combustion test standard for oxygen hoses. Further, even if carbon black is blended as a filler, this standard can be sufficiently satisfied.

Next, FIG. 1 shows a sectional view of a preferred embodiment of the oxygen hose of the present invention. This hose has a configuration in which a fiber reinforcement layer 3 is provided between an inner tube layer 1 and an outer surface protection layer 2. Here, the inner tube layer 1 is composed of a rubber composition based on NBR,
The outer protective layer 2 is made of EPT, CR or SB in consideration of weather resistance.
R, NR, or a blend system thereof, or a system in which a large amount of an antioxidant is blended can be used, and it is not always necessary to use NBR.

The fiber reinforcing layer 3 is made of, for example, vinylon, PE
T, nylon, polyethylene-2,6-naphthalate fiber (PEN fiber) or the like is knitted, for example, in a spiral shape (see FIG. 2) or a blade shape (see FIG. 3). Placed in The fibers and the knitting method used for the fiber reinforcing layer 3 are not limited, and can be appropriately selected according to the application.

[0016]

The present invention will be described below with reference to examples and comparative examples. Examples 1 and Comparative Examples 1 to 4 Various rubber compositions were prepared according to the compounding contents shown in Table 1 below, and vulcanized rubber test pieces were prepared. For the obtained test piece, annex A of JIS K6333: 1999 (normative)
The flame retardancy of the oxygen hose was evaluated according to the flame retardancy test method. Specifically, at a constant temperature of 360 ° C. to 365 ° C., 2
When placed in the apparatus for a minute, it was checked whether it would ignite. Further, the same evaluation was performed for the temperature ranges of 370 ° C. to 375 ° C. and 380 ° C. to 385 ° C. The results obtained are also shown in Table 1 below.

[0017]

[Table 1] 1) NR: RSS No. 3 2) SBR: SBR1500 manufactured by JSR Corporation 3) EPT: EP33 manufactured by JSR Corporation 4) CR: Showa Denko, Neoprene W manufactured by DuPont 5) NBR: NBR N230S manufactured by JSR Corporation 6) Dibenzothia Jildi sulfide

As can be seen from Table 1 above, SBR, EPT and NBR satisfy the above-mentioned standards as rubber polymers, and it can be seen that NBR has the highest ignition temperature. However, in the compounding system shown in Table 1 above, no plasticizer is compounded, so that the vulcanization properties are hard and the elongation is low. In addition, the low-temperature property is deteriorated, and the processability such as extrusion is also deteriorated. Therefore, it cannot be said that it is a physical property that can be used as a hose. Therefore, next, an evaluation was made of a practical compounding system containing a plasticizer.

Examples 2 to 5, Comparative Examples 5 and 6 Various rubber compositions were prepared in accordance with the practical contents of the plasticizer shown in Table 2 below, and vulcanized rubber test pieces were prepared. The obtained test specimens were evaluated for flame retardancy in accordance with the oxygen hose flame retardancy test method of Annex A (normative) of JIS K6333: 1999. Specifically, 360 ° C to 365 ° C
When placed in the apparatus at a constant temperature of 2 minutes, it was examined whether or not it would ignite. In addition, 370 ° C-375 ° C and 380 ° C
The same evaluation was performed for the temperature range of ３８385 ° C.
The obtained results are also shown in Table 2 below.

[0020]

[Table 2] 7) Dioctyl phthalate

As shown in Table 2 above, in the case where a plasticizer (DOP) was blended as a practical blend, NBR was 40%.
It can be seen that the above standard cannot be satisfied unless the amount is more than the weight part. Next, the flame retardancy when a known flame retardant was added to the SBR compounding system was evaluated.

Comparative Examples 7 to 11 Various rubber compositions were prepared in accordance with the SBR content of the flame retardant shown in Table 3 below, and vulcanized rubber test pieces were prepared. The obtained test specimens were evaluated for flame retardancy in accordance with the oxygen hose flame retardancy test method of Annex A (normative) of JIS K6333: 1999. Specifically, 360 ° C. to 365
When placed in the apparatus at a constant temperature of 2 ° C. for 2 minutes, it was examined whether or not ignition occurred. In addition, 370 ° C. to 375 ° C. and 380
The same evaluation was performed for a temperature range of from ℃ to 385 ° C. The obtained results are also shown in Table 3 below.

[0023]

[Table 3] 8) Tricresyl phosphate

As can be seen from Table 3 above, in the SBR compounding system, conventionally known flame retardants (aluminum hydroxide, chlorinated paraffin, antimony trioxide, TC
Even if P) was added, the ignition temperature of the JIS standard could not be satisfied. That is, it was found that the flame retardant had no effect of increasing the ignition temperature. Next, the flame retardancy of a carbon black non-blended system which is generally said to have high flame retardancy was evaluated.

Examples 6 and 7, Comparative Examples 12 and 13 Various rubber compositions were prepared in accordance with the contents shown in Table 4 below, and vulcanized rubber test pieces were prepared. For the obtained test piece, annex A of JIS K6333: 1999 (normative)
The flame retardancy of the oxygen hose was evaluated according to the flame retardancy test method. Specifically, at a constant temperature of 360 ° C. to 365 ° C., 2
When placed in the apparatus for a minute, it was examined whether it would ignite. Further, the same evaluation was performed for the temperature ranges of 370 ° C. to 375 ° C. and 380 ° C. to 385 ° C. Also, JIS
The normal physical properties were also evaluated according to K6301. The results obtained are also shown in Table 4 below.

[0026]

[Table 4]

From Table 4 above, it can be seen that the ignition temperature does not satisfy the above-mentioned standard even in the system not containing carbon black, which is generally said to have high flame retardancy, in the system containing SBR of Comparative Example 13. In addition, this carbon black non-compounded system has a lower tensile strength than the carbon black compounded system (Comparative Example 12). On the other hand, in the NBR blending systems of Examples 6 and 7 in which carbon black was blended, the ignition temperature was high without impairing the physical properties of the vulcanized rubber.

[0028]

As described above, the NB of the present invention is used.
A hose using a rubber composition for an oxygen hose based on R is a JIS K6333-1999 in the field of hoses used for gas welding, cutting and related operations.
The standard value of the tube rubber in the oxygen hose specified in the plate is sufficiently satisfied from a practical point of view, that is, from the viewpoint of not impairing vulcanization properties and the like.

[Brief description of the drawings]

FIG. 1 is a sectional view of an oxygen hose according to one embodiment of the present invention.

FIG. 2 is a front view of a partially cut-out portion of the oxygen hose according to one embodiment of the present invention.

FIG. 3 is a front view of a partially cut-out portion of an oxygen hose according to another embodiment of the present invention.

[Explanation of symbols]

 1 inner tube layer 2 outer surface protection layer 3 fiber reinforcement layer

Continued on the front page F-term (reference) 3H111 AA02 BA12 BA34 CB04 CC02 CC07 DA11 DB11 4F100 AK27A AK27J AK29A AK29J AK42 AK46 AK73 AL01A AN02A AS00D BA03 BA04 BA07 BA10A BA10C CA04A DA11 DG01B AC2 AC3 AC12 AC3 BB152 BG042 CP032 FD026

Claims (6)

[Claims] 1. A rubber composition for an oxygen hose, comprising an acrylonitrile-butadiene rubber as a base material. 2. The rubber composition for an oxygen hose according to claim 1, wherein the acrylonitrile-butadiene rubber is at least 40 parts by weight based on 100 parts by weight of a rubber component. 3. The rubber composition for an oxygen hose according to claim 1, further comprising a softener and / or a plasticizer. 4. The rubber composition for an oxygen hose according to claim 3, wherein the total amount of the softener and / or the plasticizer is 5 parts by weight or more based on 100 parts by weight of the rubber component. 5. An oxygen hose using the rubber composition for an oxygen hose according to any one of claims 1 to 4. 6. An oxygen hose having an inner tube layer, at least one fiber reinforcing layer wound around the outer periphery of the inner tube layer, and an outer protective layer disposed on the outer periphery of the fiber reinforcing layer. The oxygen hose according to claim 5, wherein the rubber composition for an oxygen hose according to any one of claims 1 to 4 is used for the inner tube layer.