JPH1128788A - Rubber laminate and rubber hose comprising the same - Google Patents

Abstract

(57) Abstract: A rubber laminate in which a hydrogenated or partially hydrogenated unsaturated nitrile-conjugated diene copolymer rubber layer and an acrylic rubber layer are firmly vulcanized and bonded, and such a rubber laminate. The present invention provides a rubber hose having the following structure. A rubber compound layer in which a hydrogenated or partially hydrogenated unsaturated nitrile-conjugated diene copolymer rubber is mixed with a silica-based filler and an organic peroxide, and a cross-linking agent and an organic peroxide are added to an acrylic rubber. A rubber laminate having a configuration in which a rubber compound layer containing an oxide is vulcanized and bonded, and a rubber hose having the rubber laminate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rubber laminate in which a hydrogenated or partially hydrogenated unsaturated nitrile-conjugated diene copolymer rubber layer and an acrylic rubber layer are bonded by vulcanization, and particularly as a material for automobile oil hoses and the like. It relates to a suitable rubber laminate.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 1, a rubber hose used in a lubricating oil circulation circuit of an automobile has an oil-resistant inner pipe layer 1, a fiber reinforcing layer 2, and a weather-resistant outer pipe. As shown in FIG. 2, both ends are fitted to the outer periphery of the metal pipe 5 and fixedly attached with a fastening band 6 as shown in FIG.
In recent years, the thermal conditions in the automobile engine room have become more severe due to exhaust gas measures, front-wheel drive, etc., and as a result, acrylic rubber hoses for automotive lubricating oil hoses have replaced acrylic rubber ,
Rubbers excellent in heat resistance and oil resistance such as hydrogenated acrylonitrile-butadiene rubber (hereinafter abbreviated as hydrogenated NBR) and fluorine-based rubber have been used.

[0003] Severe thermal conditions in the engine and the engine room create an environment in which various lubricating oils such as engine oil, automatic transmission fluid (hereinafter ATF), and power steering fluid deteriorate, and the deteriorated oil further attacks rubber hoses. To deteriorate the rubber material. Accordingly, it is desired that lubricating oil hose materials used in the engine room be newly provided with deterioration oil resistance in addition to basic requirements such as oil resistance, heat resistance, and cold resistance.

As the acrylic rubber, a polymer containing an acrylate or methacrylate as a main component is used. In addition, ethylene and vinyl acetate are copolymerized with the acrylate in order to improve the resistance to deterioration oil. Acrylic rubber has been proposed (JP-B-59-144).
098, Tokuhei 9-2603258). However, in recent years, lubricating oils that greatly swell rubber are sometimes used, and acrylic rubber or ethylene-acrylic rubber may not balance heat resistance, oil resistance, cold resistance, and degraded oil resistance. Was.

[0005] Next, fluororubber is the most excellent in heat resistance, oil resistance, and deterioration oil resistance, but has a problem in that it is inferior in cold resistance and workability and is expensive as compared with other rubbers.

On the other hand, hydrogenated NBR has heat resistance, oil resistance,
It has a good balance between cold resistance and oil resistance to deterioration, and has a higher elongation than other oil-resistant rubbers. In particular, the peroxide vulcanizates exhibit excellent properties in heat resistance and deterioration oil resistance. However, since hydrogenated NBR is expensive, it is conceivable to use hydrogenated NBR for the inner layer of the inner tube and use other relatively inexpensive oil-resistant rubber for the outer layer of the inner tube. In that case, the inner tube inner layer and the inner tube outer layer need to be firmly bonded, and it is desirable that they are vulcanized and bonded to avoid complicated production.

[0007] In Japanese Patent Publication No. 6-86915, hydrogenated NBR and N
NBR has been proposed, but NBR is not always sufficient from the viewpoint of heat resistance. Therefore,
An adhesive formulation of hydrogenated NBR and acrylic rubber is desired, but no patents or documents relating to a method of bonding hydrogenated NBR to acrylic rubber are found at present.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide a rubber laminate in which a hydrogenated or partially hydrogenated unsaturated nitrile-conjugated diene copolymer rubber layer and an acrylic rubber layer are firmly vulcanized and bonded. And a rubber hose having such a rubber laminate.

[0009]

According to the present invention, the following three types of rubber laminate and three types of rubber hose are provided. 1) a hydrogenated or partially hydrogenated unsaturated nitrile-conjugated diene copolymer rubber (X) layer comprising the following compound A,
A rubber laminate having a configuration in which an acrylic rubber (Y) layer comprising the following compound B is vulcanized and bonded. A: A rubber compound obtained by mixing a hydrogenated or partially hydrogenated unsaturated nitrile-conjugated diene copolymer rubber (X) with a silica filler and an organic peroxide. B: A rubber compound in which a crosslinking agent is mixed with an acrylic rubber.

2) X represents 15 to 50% by weight of a unit portion derived from an unsaturated nitrile, and 0 represents a unit portion derived from a conjugated diene.
Of a unit portion obtained by hydrogenating a unit portion from an ethylenically unsaturated monomer other than unsaturated nitrile and / or a unit portion from a conjugated diene by 85 to 30% by weight. Rubber laminate.

3) The above-mentioned 1) or 2), wherein the silica-based filler B is added with 0 to 10 phr of a silica-based filler.
Rubber laminate.

4) A hydrogenated or partially hydrogenated unsaturated nitrile-conjugated diene copolymer rubber (X) layer composed of the following compound A and an acrylic rubber (Y) layer composed of the following compound B are vulcanized. Rubber hose with bonded configuration. A: A rubber compound obtained by mixing a hydrogenated or partially hydrogenated unsaturated nitrile-conjugated diene copolymer rubber (X) with a silica filler and an organic peroxide. B: A rubber compound in which a crosslinking agent is mixed with an acrylic rubber.

5) X is 15 to 50% by weight of a unit part derived from an unsaturated nitrile, and 0 represents a unit part derived from a conjugated diene.
Of a unit portion obtained by hydrogenating a unit portion from an ethylenically unsaturated monomer other than unsaturated nitrile and / or a unit portion from a conjugated diene by 85 to 30% by weight. 4) The rubber hose according to 4), wherein

6) The rubber hose according to 4) or 5), wherein the acrylic rubber compound B contains 0 to 10 phr of a silica filler.

Hereinafter, the present invention will be described in detail. First, the hydrogenated or partially hydrogenated unsaturated nitrile-conjugated diene copolymer rubber (X) will be described. The weight percentage of unsaturated nitrile is 15-50, but more preferably 25-45. If it is less than 15, oil resistance is poor, and if it exceeds 50, cold resistance is poor.

The weight percentage of the unit moiety from the conjugated diene is 20
Although it is the following, 5 or less are more preferable. If it exceeds 20, heat resistance and deterioration oil resistance are inferior.

Examples of the silica filler added for improving the adhesive strength with the acrylic rubber include wet silica, dry silica, diatomaceous earth, and quartz powder.
A wet silica is suitable, and an acidic wet silica is more preferable, and Nipsil NV3 manufactured by Nippon Silica Co., Ltd. is exemplified.

The addition amount of the silica filler is preferably 5 to 50 parts by weight based on 100 parts by weight of the raw rubber. Furthermore, from the balance of adhesiveness, processability and various physical properties, 20 to 20
40 parts by weight is optimal.

The organic peroxide to be added can be variously exemplified. For example, diacyl peroxide such as benzoyl peroxide, dicumyl peroxide, di-t-butyl peroxide, t-butyl peroxide acetate,
t-butyl peroxyisopropyl carbonate, t-
Monoperoxy compounds such as peroxyesters such as butylperoxybenzoate and 2,5-dimethyl-2,5-di- (t-butylperoxy) -hexyne-
3,2,5-dimethyl-2,5-di- (t-butylperoxy) -hexane, α, α′-bis (t-butylperoxy) -p-diisopropylbenzene, 2,5-dimethyl-2 And diperoxy compounds such as 5-di- (benzoylperoxy) -hexane. They are,
One type may be used alone, or two or more types may be used in combination.

The appropriate addition amount of the organic peroxide varies depending on the type of the peroxide, but is preferably 0.5 to 8 parts by weight when dicumyl peroxide is used alone. If the amount is less than 0.5 part by weight, the mechanical strength and the resistance to deterioration oil are not sufficient. If the amount is more than 8 parts by weight, scorch is easily caused and the adhesive strength is reduced.

In addition to silica fillers and organic peroxides, acid acceptors such as zinc oxide and magnesium oxide, antioxidants, carbon black, plasticizers, and co-crosslinking agents such as TAIC and TMPTMA can be added as appropriate. .

Next, the acrylic rubber will be described.
The acrylic rubber (Y) used in the present invention is not particularly limited. As the acrylic rubber, for example, acrylic acid alkyl ester, methacrylic acid alkyl ester, acrylic acid monovalent group-substituted alkyl ester, methacrylic acid monovalent group-substituted alkyl ester polymer, or based on the alkyl ester And an acrylic rubber copolymerized with a second component having an active group.

Examples of the alkyl acrylate and the alkyl methacrylate include ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, butyl acrylate, butyl methacrylate and the like. Specific examples of acrylic acid monovalent group-substituted alkyl ester and methacrylic acid monovalent group-substituted alkyl ester include methoxyethyl acrylate, methoxyethyl methacrylate, ethoxyethyl acrylate,
Examples thereof include ethoxyethyl methacrylate, butoxyethyl acrylate, and butoxyethyl methacrylate.

Examples of the second component having an active group include allyl glycidyl ether, glycidyl methacrylate, dicyclopentadiene, ethylidene norbornene, vinyl chloroacetate, allyl chloroacetate, vinyl acrylate, allyl methacrylate and the like. No. Further, in the acrylic rubber, ethylene, propylene, vinyl acetate, acrylic acid, acrylonitrile, styrene,
It is desirable to copolymerize one or more monomers such as 1,3-butadiene, isoprene, and chloroprene in an amount of about 40% by weight or less.

Examples of the crosslinking agent include imidazole compounds such as 2-methylimidazole, organic ammonium carboxylate such as ammonium benzoate, polyamines such as hexamethylenediamine carbamate, and organic peroxides. Further, a small amount of a silica filler may be added to the acrylic rubber side in order to improve the adhesive strength with the hydrogenated or partially hydrogenated unsaturated nitrile-conjugated diene copolymer rubber. However, the addition amount is preferably 10 parts by weight or less based on 100 parts by weight of the raw rubber. If the amount exceeds 10 parts by weight, the storage and processing stability of the acrylic rubber deteriorates.

In addition to the crosslinking agent and the silica-based filler, an antioxidant, carbon black, a plasticizer, a processing aid such as paraffin and the like can be appropriately added.

[0027]

Next, the present invention will be described in more detail by way of examples.

First, a test method and a test result when a test piece obtained by vulcanizing and bonding hydrogenated NBR and acrylic rubber are used will be described. Table 1 shows hydrogenated NBR and acrylic rubber
According to Table 3, kneading was carried out using a Banbury mixer and an open roll. The kneaded unvulcanized 2 mm-thick sheets are brought into contact with each other, first at 100 ° C. and at a surface pressure of 2 mm.
After pre-press molding at 0 kgf / cm ² for 5 minutes, the mixture was steam-vulcanized in a steam vulcanizer at 160 ° C./45 minutes.
Further, it was vulcanized with hot air in a gear oven at 150 ° C. for 8 hours. This is cut into 25 mm width, and JIS K 625
According to No. 6, a T-type peel test was performed. Table 1 shows the results.

The term "adhered state" in Table 1 is obtained by visually observing whether or not the hydrogenated NBR sheet and the acrylic rubber sheet are adhered in the peel test. On the peeled surface of the hydrogenated NBR sheet and acrylic rubber sheet, the entire surface is rubber broken when the rubber is broken, some rubber is broken and the other is partially peeled at the interface, and the entire surface is peeled at the interface. Is shown as interfacial peeling.

Next, the production method, performance evaluation method, and test results when a hose is produced according to the present invention will be described. FIG. 3 shows one application example of the present invention.
1a is an inner tube inner layer made of a compound of hydrogenated NBR rubber, 1
b indicates an inner tube outer layer made of an acrylic rubber compound,
The inner tube has a double structure of 1a and 1b. 2 indicates a fiber reinforcing layer, and 3 indicates an outer tube layer. As an example of the method for producing the rubber hose of the present invention, the hydrogenated NBR rubber compound kneaded by a Banbury mixer and an open roll and the acrylic rubber compound obtained in the same manner are formed into two layers by an extruder. After extruding the outer layer (acrylic rubber compound) on the inner layer (hydrogenated NBR rubber compound) by co-extrusion or two extruders, form a fiber reinforcement layer on it and then extrude the outer tube layer It is extruded and integrated by a machine and vulcanized and adhered. As vulcanization conditions, after vulcanizing in a steam can at 145 to 170 ° C / 30 to 90 minutes,
Further, post-vulcanization is generally performed at 145 to 170 ° C./2 to 12 hours in a hot air oven.

The hydrogenated NBR rubber compound and the acrylic rubber compound are simultaneously extruded as an inner layer and an outer layer of an inner tube, and a reinforcing layer made of braided aramid fibers is provided on the outer periphery thereof. An outer tube layer was applied to produce a rubber hose. Then, at 160 ° C / 45 in a steam can
After minute steam vulcanization, hot air vulcanization was performed in a hot air oven at 150 ° C. for 8 hours. The inner diameter of the hose is 7.5 mm, and the thickness of each layer is 0.5 mm for the inner layer of the inner tube and 1.5 m for the outer layer of the inner tube.
m, the outer tube layer is 1.5 mm.

The performance of the rubber hose obtained as described above was evaluated. First, the peel strength of the inner tube inner layer and the inner tube outer layer in the normal state of the rubber hose was measured according to JIS K6.
Measured according to 256. Further, a commercially available ATF was sealed in a hose having a length of 300 mm, the both ends were sealed, and aged in a gear oven at 150 ° C. for 200 hours. Thereafter, the peel strength was measured by the same method. Table 4 shows the test results. The numbers of Examples and Comparative Examples in Table 4 correspond to the numbers of Examples and Comparative Examples shown in Table 1 above.

[0033]

[Table 1]

[0034]

[Table 2]

[0035]

[Table 3]

[0036]

[Table 4]

[0037]

According to the present invention, a rubber laminate in which a hydrogenated or partially hydrogenated unsaturated nitrile-conjugated diene copolymer rubber typified by hydrogenated NBR and an acrylic rubber are firmly vulcanized and bonded, and A rubber hose having a simple rubber laminate is obtained.

Specific applications of the rubber hose according to the present invention include various types of lubricating oil hoses for automobiles (engine oil hoses, automatic transmission hoses, power steering hoses, etc.), as well as fuel hoses and air hoses.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a conventional hose.

FIG. 2 is a longitudinal sectional view showing a use state of a hose.

FIG. 3 is a cross-sectional view of one embodiment of the hose of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Inner tube layer 1a Inner tube inner layer 1b Inner tube outer layer 2 Fiber reinforcement layer 3 Outer tube layer 4 Rubber hose 5 Metal pipe 6 Fastening band

Claims (6)

[Claims] 1. A hydrogenated or partially hydrogenated unsaturated nitrile-conjugated diene copolymer rubber (X) layer comprising the following compound A and an acrylic rubber (Y) layer comprising the following compound B are vulcanized. A rubber laminate having a bonded configuration. A: A rubber compound obtained by mixing a hydrogenated or partially hydrogenated unsaturated nitrile-conjugated diene copolymer rubber (X) with a silica filler and an organic peroxide. B: A rubber compound in which a crosslinking agent is mixed with an acrylic rubber. 2. X is a unit moiety derived from an unsaturated nitrile of 1
5 to 50% by weight, and 0 to 2 of the unit part from the conjugated diene.
0% by weight, and 85 to 30% by weight of a unit part obtained by hydrogenating a unit part from an ethylenically unsaturated monomer other than unsaturated nitrile and / or a unit part from a conjugated diene. The rubber laminate according to claim 1, wherein: 3. The rubber laminate according to claim 1, wherein a silica filler is added to the acrylic rubber compound B in an amount of 0 to 10 phr. 4. A hydrogenated or partially hydrogenated unsaturated nitrile-conjugated diene copolymer rubber (X) layer comprising the following formulation A and an acrylic rubber (Y) layer comprising the following formulation B are vulcanized. Rubber hose with bonded configuration. A: A rubber compound obtained by mixing a hydrogenated or partially hydrogenated unsaturated nitrile-conjugated diene copolymer rubber (X) with a silica filler and an organic peroxide. B: A rubber compound in which a crosslinking agent is mixed with an acrylic rubber. 5. X is a unit moiety derived from an unsaturated nitrile.
5 to 50% by weight, and 0 to 2 of the unit part from the conjugated diene.
0% by weight, and 85 to 30% by weight of a unit part obtained by hydrogenating a unit part from an ethylenically unsaturated monomer other than unsaturated nitrile and / or a unit part from a conjugated diene. The rubber hose according to claim 4, wherein 6. The rubber hose according to claim 4, wherein 0 to 10 phr of a silica filler is added to the acrylic rubber compound B.