JP4254398B2 - Stainless steel-nitrile rubber composite - Google Patents

Description

  The present invention relates to a stainless steel-nitrile rubber composite. More specifically, the present invention relates to a stainless steel-nitrile rubber composite suitably used as a gasket material such as an engine cylinder head gasket.

  Stainless steel plates are used for rubber metal composites that require hydrophobicity. However, even if a conventional vulcanized adhesive is applied onto the stainless steel plate and the rubber is vulcanized and bonded, the liquid-resistant adhesion durability is maintained. Unfortunately, when the immersion test is carried out in the liquid, adhesion peeling occurs. As a countermeasure, chromate treatment is applied to the surface of stainless steel as a pretreatment before applying adhesive, and there is a method to improve resistance to water and LLC (long life coolant), but hexavalent Cr that adversely affects the human body and the environment is available. It is preferable not to use the contained chromate treating agent.

Under such circumstances, the present inventors have proposed various undercoat adhesives, topcoat adhesives, combinations thereof, and once-applied adhesives in the following patent application specifications and the like. These adhesives have been confirmed to be able to withstand fairly high temperatures and long-term conditions in tests where they are simply immersed in various liquids such as water and LLC. However, the rubber metal laminate is often used as a gasket material or the like, and in such an actual use environment, in many cases, different metals are simultaneously in contact with each other in the same liquid. In such a case, a potential is generated between the stainless steel plate forming the rubber metal laminate and the dissimilar metal in contact with the stainless steel plate, and a phenomenon in which adhesion peeling or blister generation is promoted is observed. Even in such an environment, there was no Cr-free rubber-metal composite that did not cause adhesion peeling or blistering.
Japanese Patent Laid-Open No. 11-221875 JP 2000-6308 A JP 2004-11576 A JP 2004-76699 A JP 2004-277435 A

  The object of the present invention is a stainless steel-nitrile rubber composite, which is used in places where electrolytes such as water and various aqueous solutions exist, or in which the stainless steel plate is used in contact with dissimilar metals. Another object is to provide a material that can significantly suppress the occurrence of adhesion peeling and blistering.

The object of the present invention is (1) a composite comprising a stainless steel plate not subjected to surface treatment or surface-treated with a hexavalent Cr-free surface treatment agent, an adhesive layer, and a vulcanized nitrile rubber layer. Stainless steel-nitrile rubber composite containing metal powder with lower ionization energy than hydrogen in at least one of the agent layer and vulcanized nitrile rubber layer or (2) No surface treatment or hexavalent Cr free A composite comprising a stainless steel plate, an adhesive layer, a vulcanized nitrile rubber layer, and an anti-adhesive agent layer surface-treated with a surface treatment agent, wherein a metal powder having a lower ionization energy than hydrogen is contained in the anti-adhesive agent layer. This is achieved by the included stainless steel-nitrile rubber composite. In the case of (1), an anti-tack agent layer can be further provided on the vulcanized nitrile rubber layer, and in the case of (2), at least one of the adhesive layer and the vulcanized nitrile rubber layer can be further provided. It is preferable to include a metal powder having a lower ionization energy than hydrogen in the layer.

  Cr treatment-free stainless steel-nitrile rubber composite (mainly SUS rubber metal laminated gasket) consisting of stainless steel plate, adhesive layer, vulcanized nitrile rubber layer (and anti-tack agent layer), adhesive layer, vulcanized At least one of the nitrile rubber layer and the anti-blocking agent layer was used in an electrolyte solution containing a mixture of corrosive metal members such as aluminum and iron by containing a metal powder having a lower ionization energy than hydrogen. Even in the case, the composite material has an effect of suppressing the peeling of the adhesive and the generation of blisters.

  In consideration of the mechanism by which such effects are manifested, a case where a corrosive metal such as aluminum or iron and a composite material (rubber metal composite) containing no metal powder with lower ionization energy than hydrogen are immersed in the electrolyte solution Since an electric potential is generated between the composite material and the corrosive metal, the corrosive metal causes an anodic reaction, and hydrogen gas is generated by the cathode reaction on the stainless steel surface of the composite material. It was obtained as a new finding that peeling and blistering occurred. In the present invention, by adding a metal powder having a lower ionization energy than hydrogen to the other part of the composite material instead of the stainless steel plate that undergoes the cathode reaction, can the potential generated between the composite and the dissimilar metal be suppressed? Because the metal powder with lower ionization energy than the blended hydrogen causes sacrificial corrosion and becomes the anode, the cathode reaction is unlikely to occur at the stainless steel plate interface, resulting in the suppression of hydrogen gas generation at the adhesive interface and adhesion. It is considered that peeling on the surface and generation of blisters are effectively prevented.

  As described above, the addition of the metal powder having a lower ionization energy than hydrogen is performed in at least one of the adhesive layer, the vulcanized rubber layer, and the anti-tacking agent layer. It is preferable to cause the cathode reaction on the surface of the vulcanized nitrile rubber layer or the anti-adhesive agent layer away from the agent layer, and for the convenience of the actual production process, the addition to the vulcanized nitrile rubber layer is the most preferable implementation. It can be said that it is a form.

  The rubber metal laminate of the present invention is also used in an environment where different metals are not coexisting, and where there are electrolytes such as water and various aqueous solutions. The stainless steel sheet is used in an untreated or surface-treated state, and as a surface treatment agent, particularly in the case of a copolymer oligomer of an amino group-containing alkoxysilane and a vinyl group-containing alkoxysilane, in water, various aqueous solutions, etc. In simple immersion, it is possible to obtain good peeling resistance without adding a metal powder that has a lower ionization energy than hydrogen, but in immersion tests that take into account the potential difference between different metals, Even if a surface-treated stainless steel plate is used, it is not effective for preventing peeling, and in this case also, addition of metal powder having a lower ionization energy than hydrogen to each layer is extremely effective.

As the stainless steel plate, SUS304, 430, 301, 301H, etc., and those having a thickness of about 0.05 to 1.0 mm are generally used for gasket applications. A stainless steel plate that has been degreased but not surface-treated is used, but preferably a surface-treated steel plate is used. As the surface treatment agent, trivalent Cr-based, organic resin, an organic-inorganic composite, a silane coupling agent based, Zr-based, the use of any as long as it is hexavalent Cr-free surface treating agent Ti system such as However, a copolymer oligomer of an amino group-containing alkoxysilane and a vinyl group-containing alkoxysilane is particularly preferably used.

  Examples of the amino group-containing alkoxysilane that is one component of the copolymer oligomer include γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, and N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane. N-β- (aminoethyl) -γ-aminopropyltriethoxysilane and the like are used. As the vinyl group-containing alkoxysilane which is another component, for example, vinyltrimethoxysilane, vinyltriethoxysilane or the like is used. In the oligomerization reaction, 25 to 400 parts by weight, preferably 50 to 150 parts by weight of vinyl group-containing alkoxysilane and 20 to 150 parts by weight of water for hydrolysis are used with respect to 100 parts by weight of amino group-containing alkoxysilane. .

  In the oligomerization reaction, these are charged into a reactor having a distillation apparatus and a stirrer, and stirred at about 60 ° C. for about 1 hour. Thereafter, an acid such as formic acid or acetic acid is added within 1 hour to about 1 to 2 moles per mole of amino group-containing alkoxysilane. The temperature at this time is kept at about 65 ° C. The mixture is further stirred for 1 to 5 hours to allow the reaction to proceed, and at the same time, the alcohol produced by hydrolysis is distilled under reduced pressure. Distillation is terminated when only distilled water is present, and then diluted and adjusted such that the silane concentration is 30 to 80% by weight, whereby the desired copolymer oligomer is obtained. This copolymer oligomer is an oligomer having a degree soluble in an alcohol-based organic solvent such as methanol or ethanol. Moreover, what is already marketed as a copolymerization oligomer can also be used as it is. These copolymer oligomers are used as a mixed solvent solution of these alcohol-based organic solvents, ketone-based organic solvents such as acetone and methyl ethyl ketone, or water and 20% by weight or less thereof.

  Preferably, a vulcanized adhesive for nitrile rubber, generally a phenol resin-based or nitrile rubber-containing phenol resin-based vulcanized adhesive, on a stainless steel plate surface-treated with one or both of these surface treatment agents. Is applied. The vulcanized adhesive is prepared as a solution of about 0.5 to 10% by weight of an alcoholic organic solvent such as methanol, ethanol or isopropanol, or a ketone organic solvent such as acetone or methylethylketone, which is dipped, sprayed or brushed. After applying by roll coating method and drying with room temperature or warm air, it is baked at about 100 to 250 ° C for about 1 to 20 minutes, and an adhesive layer having a film thickness of about 0.1 to 15 μm is formed on the stainless steel plate. Let it form.

  On the adhesive layer formed in this manner, a vulcanized nitrile rubber layer is formed by bringing a non-vulcanized nitrile rubber compound into contact with heat and vulcanizing. The unvulcanized nitrile rubber compound is preferably an organic peroxide crosslinking type, but other sulfur or sulfur donating compound vulcanizing agent types are also used. These unvulcanized rubber compounds are applied as an organic solvent solution so as to form a vulcanized nitrile rubber layer having a single-side vulcanizate layer thickness of about 5 to 120 μm, and about 1 to 15 at room temperature to about 100 ° C. After removing the solvent by drying for 5 minutes, it is heated and vulcanized at about 150 to 230 ° C. for about 0.5 to 30 minutes, and in some cases is heated under pressure.

An anti-tack agent layer is formed on the vulcanized nitrile rubber layer when its surface non-tackiness is required. The anti-tacking agent is used for the purpose of preventing sticking between rubbers or between rubber and metal, and any anti-tacking agent can be used as long as it can form a film on the vulcanized nitrile rubber layer. , Fluorine-based, graphite-based, amide, paraffin-based wax-based, polybutadiene-based, etc., preferably liquid 1,2-polybutadiene hydroxyl group-containing material, 1,2-polybutadiene isocyanate group-containing material and polyolefin-based resin An anti-sticking agent comprising an organic solvent dispersion is used.
Japanese Patent Laid-Open No. 7-165953

  At least one of these pressure-sensitive adhesive layer and vulcanized nitrile rubber layer (and anti-tacking agent layer) is used by adding a metal powder having an ionization energy lower than that of hydrogen. The metal powder having a lower ionization energy than hydrogen is a powder of Al, Mg, Zn, Fe or the like, preferably an Al powder having an average particle size of about 1 to 30 μm, preferably about 5 to 10 μm. Used. The metal powder having a lower ionization energy than hydrogen is preferably used in a paste form. Moreover, the metal powder having a lower ionization energy than hydrogen may be one that has been subjected to coupling agent surface treatment or resin coating treatment.

  When metal powder having a lower ionization energy than hydrogen (hereinafter simply referred to as metal powder) is added to the adhesive layer, it may be added directly to the vulcanized adhesive and dispersed with a homogenizer, dyno mill or the like. However, from the viewpoint of dispersibility, it is preferable to add the metal powder by adding an unvulcanized nitrile rubber compound solution to which the metal powder has been added to the vulcanized adhesive. The addition ratio cannot be generally determined by the concentration of the vulcanized adhesive, the solution concentration of the unvulcanized nitrile rubber compound, and the ratio of the metal powder added thereto. The amount is about 1 to 80 parts by weight, preferably about 5 to 30 parts by weight per 100 parts by weight of the nonvolatile content of the rubber compound, and these are prepared as an organic solvent dispersion using a homogenizer, dyno mill or the like.

  When metal powder is added to the vulcanized nitrile rubber layer, the metal powder is added at a rate of about 0.5 to 80 parts by weight, preferably about 2 to 20 parts by weight per 100 parts by weight of the unvulcanized nitrile rubber compound. Is done. Dispersion of the metal powder in the compound may be carried out using an open roll or the like, or may be carried out using a high-speed stirrer such as a homogenizer or a disperser such as a dyno mill as the organic solvent solution.

  When the metal powder is added to the anti-blocking agent layer, it is used by adding 0.1 to 30% by weight, preferably about 1 to 5% by weight in the anti-blocking agent solution. The metal powder-containing anti-adhesive agent layer is formed on the vulcanized nitrile rubber layer by applying a method such as roll coater, spraying or dipping so that the thickness of the surface layer to be formed is about 2 μm or more. And heating at about 150 to 250 ° C. for about 1 to 10 minutes.

  Such a metal powder-containing layer is formed in a composite comprising a stainless steel plate, an adhesive layer, a vulcanized nitrile rubber layer (and an anti-tacking agent layer), an adhesive layer, a vulcanized nitrile rubber layer, or both of them. Or a composite comprising a stainless steel plate, an adhesive layer, a vulcanized nitrile rubber layer and an anti-tacking agent layer, and at least one of the anti-tacking agent layer, the adhesive layer and the vulcanized nitrile rubber layer. With 2 or 3 layers.

  For stainless steel-nitrile rubber composites that have at least one metal powder-containing layer with a lower ionization energy than hydrogen, an immersion test that takes into account the potential difference between different metals is conducted to effectively prevent adhesion peeling and blistering. It can be used as a measure of sex. Such a potential difference immersion test between different metals is carried out by, for example, a rubber metal laminated plate and an aluminum plate for a predetermined time in 95 ° C. pure water and 95 ° C. 0.1 wt% sodium hydrogen carbonate aqueous solution in a glass container. So that the top is in contact with a clip so that the top is in contact with a reverse V shape, the top is positioned above the liquid level, and the rubber metal laminate at the contact part scrapes off the rubber part. The immersion test is performed so that the portion is in direct contact with the aluminum plate, and then the Gobang eye peel test is performed, and the effect can be reproduced experimentally. Therefore, it can be said that such a test method itself is an effective potential difference immersion test method between different kinds of metals.

  Next, the present invention will be described with reference to examples.

Examples 1-12, Comparative Examples 1-5
The vulcanized adhesive A was applied to both surfaces of the SUS301H steel plates A to D that had been subjected to alkali degreasing and surface treatment, dried at room temperature, and then baked at 190 ° C. for 5 minutes to form a vulcanized adhesive layer. . NBR solutions A to I were applied to this vulcanized adhesive layer and dried at 60 ° C. for 15 minutes to form an unvulcanized NBR layer with a thickness of 20 μm on one side, 180 ° C., 5.88 MPa (60 kgf / cm ² ) Pressure vulcanization was carried out under conditions of 10 minutes to produce a stainless steel-nitrile rubber composite (rubber metal laminate).

Surface-treated steel sheet A: Cr-free surface treatment agent (Nippon Parkerizing product Palcoat E300) was applied at 0.2 g / m ² on degreased SUS301H steel sheet and dried at 100 ° C for 10 minutes. B: Zr-based surface treatment agent (Nippon Parkerizing product Palcoat 3762) was applied to the degreased SUS301H steel plate at a coating amount of 0.2 g / m ² and dried at 100 ° C. for 10 minutes. Surface-treated steel plate C: Degreased A silane coupling agent-based surface treatment agent (load far yeast product AP-133) was applied to a SUS301H steel plate at a coating amount of 0.1 g / m ² and dried at 100 ° C. for 10 minutes. Surface-treated steel plate D: Stirrer, A three-necked flask equipped with a heating jacket and a dropping funnel is charged with 40 parts by weight of γ-aminopropyltriethoxysilane and 20 parts by weight of water, and the pH is adjusted by adding acetic acid until the pH is 4-5, and several minutes. After stirring, while further stirring, continue Gradually add 40 parts by weight of the run using a dropping funnel, and after completion of the dripping, heat to reflux at about 60 ° C for 5 hours.
The copolymer oligomer obtained by cooling to room temperature was applied on a degreased SUS301H steel sheet at a coating amount of 0.1 g / m ² and dried at 190 ° C. for 5 minutes.
NBR solution A: 100 parts (by weight, the same below) of nitrile rubber compound of the following formulation that has been previously kneaded is dissolved in 300 parts of a toluene-methyl ethyl ketone (9: 1) mixed solvent to obtain a solid concentration of 25% by weight. % Organic solvent solution
NBR (JSR product N235S) 100 parts
SRF carbon black 80 parts Calcium carbonate 80 parts Silica 20 parts Zinc flower 5 parts Anti-aging agent (Ouchi Emerging Chemicals product NOCRACK 224) 2 parts Triallyl isocyanurate 2 parts
1,3-bis (tert-butylperoxy) isopropylbenzene 2.5 parts Plasticizer (Bayer product buchanol OT) 5 parts
NBR solution B: 18 parts of aluminum paste (Showa aluminum powder product 210N; Al average particle size 9 μm, Al content 65% by weight) is kneaded into 100 parts of the nitrile rubber compound of the above formulation using an open roll and kneaded. The mixed dough is dissolved in the above mixed solvent to obtain an organic solvent solution having a solid content of 25% by weight.
NBR solution C: In NBR solution A used in the above weight, 18 parts of aluminum paste (210N) was added to 100 parts of the non-volatile content of the rubber compound and dispersed using a homogenizer.
NBR solution D: Dino mill was used instead of homogenizer in NBR solution C.
NBR solution E: In NBR solution C, the amount of aluminum paste was changed to 3 parts
NBR solution F: In NBR solution C, the amount of aluminum paste was changed to 30 parts
NBR solution G: Aluminum paste surface-treated with a coupling agent as an aluminum paste in NBR solution C (Toyo Aluminum product LZ; Al average particle size 9 μm,
Al content 65% by weight) was used
NBR solution H: In NBR solution C, 12 parts of resin-coated aluminum paste (the company's product FZ; Al average particle size 9 μm, Al content 65% by weight) was used as the aluminum paste.
NBR solution I: In NBR solution C, the same amount of resin-coated zinc powder (chemical product #F; Zn average particle size 3.8 μm) was used instead of aluminum paste. Vulcanized adhesive A: Additive for commercial nitrile rubber Prepared from 100 parts of sulfur adhesive (Metal Rock N-15, Toyo Chemical Laboratory product), 50 parts of NBR solution A and 700 parts of methyl ethyl ketone

The rubber metal laminate produced was subjected to a simple immersion test in pure water at 120 ° C and 0.1% by weight sodium hydrogen carbonate aqueous solution at 95 ° C for 100 hours, 300 hours, and 500 hours, respectively, followed by a gobang eye peel test (JIS K5600-5-6 coating adhesion test method = cross-cut method = compliant) was carried out.
[Classification of test results according to JIS K5600-5-6]
(Category) (Description)
Zero- cut edges are perfectly smooth and there is no peeling to any lattice eye
Small peeling of paint film at one- cut intersection
The cross-cut portion is clearly not affected by more than 5%
2 coatings are peeled along the edges of the cut and / or at the intersection
The cross-cut portion affected is clearly more than 5% but not a child of more than 15%
3 The coating is partially or completely peeled along the edges of the cut and / or various parts of the eye are partially or completely peeled off
The cross-cut portion is clearly affected by more than 15% but not more than 35%
4 The coating is partially or completely peeled along the edge of the cut, and / or some eyes are partially or completely peeled off
It is clearly not more than 35% that is affected at the crosscut.
Any of the degree of peeling that cannot be classified even with 5 classification 4

Furthermore, as a soaking test that takes into account the potential difference between different metals, the rubber metal laminate and aluminum were placed in 95 ° C. pure water and 95 ° C. 0.1% by weight sodium bicarbonate aqueous solution for a predetermined time, respectively, in a glass container. Hold the plate with a clip etc. so that the top is in an inverted V shape and make contact with the top, so that the vicinity of the top is positioned above the liquid level, and the rubber metal laminate at the contact part scrapes the rubber part, stainless steel After the immersion test was performed so that the steel plate portion was in direct contact with the aluminum plate, a gobang eye peel test was performed.

The obtained results are shown in the following Table 1 (Example 1) and Table 2 (Comparative Example). In the configuration of the rubber metal laminate, the steel sheet (SUS301H) that is described as a steel sheet in the column of the surface-treated steel sheet is a surface-treated steel sheet (SUS301H).
Table 1
Example
1 2 3 4 5 6 7 8 9 10 11 12
[Rubber metal laminate]
Surface-treated steel plate Steel plate ABCDCCCCCCCCC
NBR solution C C C C C C B D E F G H I
[Simple immersion test]
Pure water (120 ℃)
100 hours 0 0 0 0 0 0 0 0 0 0 0 0
300 hours 0 0 0 0 0 0 0 0 0 0 0 0
500 hours 0 0 0 0 0 0 0 0 0 0 0 0
NaHCO ₃ aqueous solution (95 ° C)
100 hours 0 0 0 0 0 0 0 0 0 0 0 0
300 hours 0 0 0 0 0 0 0 0 0 0 0 0
500 hours 1 0 0 0 0 0 0 0 0 0 0 0
[Potential difference immersion test]
Pure water (95 ℃)
70 hours 0 0 0 0 0 0 0 0 0 0 0 0
140 hours 2 1 1 0 0 0 0 1 0 0 0 1
300 hours 2 2 2 1 0 1 1 2 1 0 0 2
NaHCO ₃ aqueous solution (95 ° C)
70 hours 2 1 1 0 0 0 0 1 0 0 0 1
140 hours 4 2 2 1 0 0 1 2 1 0 0 2

Table 2
Comparative example
1 2 3 4 5
[Rubber metal laminate]
Surface-treated steel plate Steel plate A B C D
NBR solution A A A A A
[Simple immersion test]
Pure water (120 ℃)
100 hours 2 1 1 0 0
300 hours 3 2 1 1 0
500 hours 4 2 2 2 1
NaHCO ₃ aqueous solution (95 ° C)
100 hours 2 1 1 1 0
300 hours 3 2 2 2 0
500 hours 5 3 2 3 0
[Potential difference immersion test]
Pure water (95 ℃)
70 hours 4 3 2 2 2
140 hours 5 4 4 3 3
300 hours 5 5 5 4 4
NaHCO ₃ aqueous solution (95 ° C)
70 hours 5 4 5 4 3
140 hours 5 5 5 5 5

Examples 13-24, Comparative Examples 6-10
In Examples 1 to 12, rubber metal laminates were produced in the same manner using vulcanized adhesives B to G.
Vulcanized adhesive B: Prepared by adding 10 parts of aluminum paste (210N) and 118 parts of methyl ethyl keton to vulcanized adhesive A. Vulcanized adhesive C: 100 parts of novolac type phenolic resin (Gunei Chemical Product Resid Top PSF2803), Resol type phenol resin 49% by weight solution (Sumitomo Bakelite product Sumilite PR-50232) 136 parts, hexamethylenetetramine 10 parts, NBR solution A 303 parts, aluminum paste (210N) 58 parts and methyl ethyl ketone 5201 parts Adhesive D: Prepared by changing the amount of aluminum paste to 20 parts in vulcanized adhesive C and changing the amount of methyl ethyl ketone to 4735 parts. Vulcanized adhesive E: 116 parts of aluminum paste in vulcanized adhesive C In addition, it was prepared by changing the amount of methyl ethyl ketone to 5891 parts. Vulcanized adhesive F: In vulcanized adhesive C, an aluminum paste surface-treated with a coupling agent as an aluminum paste. Luminium paste (LZ) used in the same amount Vulcanized adhesive G: In vulcanized adhesive C, the same amount of resin-coated aluminum paste (FZ) was used as the aluminum paste.

The produced rubber metal laminate was similarly subjected to a simple immersion test and an immersion test in consideration of a potential difference between different metals. The obtained results are shown in the following Table 3 (Example) and Table 4 (Comparative Example).
Table 3
Example
13 14 15 16 17 18 19 20 21 22 23 24
[Rubber metal laminate]
Surface-treated steel plate Steel plate ABCDCCCCCCCCC
Vulcanized adhesive C C C C C C B D E F G B C
NBR solution A A A A A A A A A A A B B
[Simple immersion test]
Pure water (120 ℃)
100 hours 0 0 0 0 0 0 0 0 0 0 0 0
300 hours 0 0 0 0 0 0 0 0 0 0 0 0
500 hours 0 0 0 0 0 0 0 0 0 0 0 0
NaHCO ₃ aqueous solution (95 ° C)
100 hours 0 0 0 0 0 0 0 0 0 0 0 0
300 hours 0 0 0 0 0 0 0 0 0 0 0 0
500 hours 1 0 0 0 0 0 0 0 0 0 0 0
[Potential difference immersion test]
Pure water (95 ℃)
70 hours 0 0 0 0 0 0 0 0 0 0 0 0
140 hours 2 1 1 0 0 1 0 0 0 0 0 0
300 hours 3 2 2 1 0 2 2 1 1 0 0 0
NaHCO ₃ aqueous solution (95 ° C)
70 hours 1 1 1 0 0 0 0 0 0 0 0 0
140 hours 4 2 3 2 1 2 2 2 2 1 1 0

Table 4
Comparative example
6 7 8 9 10
[Rubber metal laminate]
Surface-treated steel plate Steel plate A B C D
Vulcanized adhesive A A A A A
NBR solution A A A A A
[Simple immersion test]
Pure water (120 ℃)
100 hours 2 1 1 0 0
300 hours 3 2 1 1 0
500 hours 4 2 2 2 1
NaHCO ₃ aqueous solution (95 ° C)
100 hours 2 1 1 1 0
300 hours 3 2 2 2 0
500 hours 5 3 2 3 0
[Potential difference immersion test]
Pure water (95 ℃)
70 hours 4 3 2 2 2
140 hours 5 4 4 3 3
300 hours 5 5 5 4 4
NaHCO ₃ aqueous solution (95 ° C)
70 hours 5 4 5 4 3
140 hours 5 5 5 5 5

Examples 25-34, Comparative Examples 11-15
In Examples 13 to 24, after vulcanizing under pressure using vulcanized adhesives A and B, the surface was further coated with anti-adhesive agents A to D and dried at 200 ° C. for 3 minutes to obtain a rubber laminated metal. A plate was made.

Anti-adhesive A: 100 parts of 1,2-polybutadiene hydroxyl group-containing product (Nisso Polybuta GQ1000, 45% by weight xylene solution), 1,2-polybutadiene isocyanate group-containing product (Nisso polybuta TP1001, 50% by weight butyl acetate) Solution) Prepared from 85 parts of polyolefin resin organic solvent dispersion (Mitsui Chemicals High Wax 320P) 112 parts, 75 parts of aluminum paste (210N) and 1430 parts of toluene Anti-adhesive B: In anti-adhesive A, the amount of aluminum paste Prepared by changing to 27 parts Anti-adhesive agent C: Prepared by changing the amount of aluminum paste to 138 parts in anti-adhesive agent A Anti-adhesive agent D: Aluminum paste in anti-adhesive agent A was not added

The obtained results are shown in the following Table 5 (Example) and Table 6 (Comparative Example).
Table 5
Example
25 26 27 28 29 30 31 32 33 34
[Rubber metal laminate]
Surface-treated steel plate Steel plate ABCDCCCCC
Vulcanized adhesive A A A A A B A B A A
NBR solution A A A A A A A B B A A
Anti-adhesive agent A A A A A A A A A B C
[Simple immersion test]
Pure water (120 ℃)
100 hours 0 0 0 0 0 0 0 0 0 0
300 hours 1 0 1 1 0 1 0 0 1 1
500 hours 2 1 1 1 0 1 0 0 1 1
NaHCO ₃ aqueous solution (95 ° C)
100 hours 0 0 0 0 0 0 0 0 0 0
300 hours 1 0 1 1 0 1 0 0 1 1
500 hours 2 2 2 2 0 1 0 0 2 2
[Potential difference immersion test]
Pure water (95 ℃)
70 hours 1 0 0 0 0 0 0 0 0 0
140 hours 2 1 1 0 0 0 0 0 0 0
300 hours 3 2 2 1 0 0 0 0 1 0
NaHCO ₃ aqueous solution (95 ° C)
70 hours 2 1 1 1 1 1 0 0 1 1
140 hours 4 2 3 2 1 1 0 0 2 1

Table 6
Comparative example
11 12 13 14 15
[Rubber metal laminate]
Surface-treated steel plate Steel plate A B C D
Vulcanized adhesive A A A A A
NBR solution A A A A A
Anti-adhesive agent D D D D D
[Simple immersion test]
Pure water (120 ℃)
100 hours 2 1 1 0 0
300 hours 3 2 1 1 0
500 hours 4 2 2 2 1
NaHCO ₃ aqueous solution (95 ° C)
100 hours 2 1 1 1 0
300 hours 3 2 2 2 0
500 hours 5 3 2 3 0
[Potential difference immersion test]
Pure water (95 ℃)
70 hours 4 3 2 2 2
140 hours 5 4 4 3 3
300 hours 5 5 5 4 4
NaHCO ₃ aqueous solution (95 ° C)
70 hours 5 4 5 4 3
140 hours 5 5 5 5 5

The stainless steel-nitrile rubber composite according to the present invention is effectively used as a gasket material and the like, and particularly when used as a gasket for a head of an aluminum engine cylinder, which is a dissimilar metal, adhesion that occurs in a short time under immersion conditions. Agent peeling and blistering can be effectively prevented. Other than this, it can be effectively used as a rubber metal composite for automobiles, industrial machines, electronics, electricity, etc. that require water resistance such as water pump seals.

Claims (10)

A composite comprising a stainless steel plate, an adhesive layer and a vulcanized nitrile rubber layer that is not surface-treated or surface-treated with a hexavalent Cr-free surface treatment agent, and has a small amount of adhesive layer and vulcanized nitrile rubber layer. A stainless steel-nitrile rubber composite in which a metal powder having a lower ionization energy than hydrogen is contained in one layer.   The stainless steel-nitrile rubber composite according to claim 1, wherein an anti-adhesive layer is further provided on the vulcanized nitrile rubber layer. A composite comprising a stainless steel plate, an adhesive layer, a vulcanized nitrile rubber layer, and an anti-blocking agent layer that is not surface-treated or surface-treated with a hexavalent Cr-free surface-treating agent. Stainless steel-nitrile rubber composite containing metal powder having lower ionization energy than hydrogen.   The stainless steel-nitrile rubber composite according to claim 3, wherein a metal powder having a lower ionization energy than hydrogen is contained in at least one of the pressure-sensitive adhesive layer and the vulcanized nitrile rubber layer. The stainless steel-nitrile rubber composite according to claim 1 or 3, wherein the metal powder having a lower ionization energy than hydrogen is a powder of Al, Mg, Zn or Fe . The stainless steel-nitrile rubber composite according to claim 1 or 3, wherein the surface treatment agent is a copolymer oligomer of an amino group-containing alkoxysilane and a vinyl group-containing alkoxysilane.   The stainless steel-nitrile rubber composite according to any one of claims 1 to 6, which is used in a place where an electrolyte such as water or various aqueous solutions exists in a use environment.   The stainless steel-nitrile rubber composite according to any one of claims 1 to 6, wherein the stainless steel plate is used in contact with a dissimilar metal in a use environment.   The stainless steel-nitrile rubber composite according to any one of claims 1 to 8, which is used as a gasket.   The stainless steel-nitrile rubber composite according to claim 9, which is used as an engine cylinder head gasket.