JP4407424B2 - Fluoro rubber-metal laminated gasket material - Google Patents

Description

  The present invention relates to a fluororubber-metal laminated gasket material. More specifically, the present invention relates to a fluororubber-metal laminated gasket material suitably used as an engine cylinder head gasket or the like.

  Stainless steel is mainly used as the metal material for cylinder head gasket materials for engines that require water resistance, LLC (long life coolant) resistance, and heat resistance. Even if it is applied and bonded to rubber, the liquid-resistant adhesion durability is poor, and when this rubber metal laminate is subjected to an immersion test in water, LLC or the like, adhesion peeling occurs.

As a countermeasure for this, the present applicant has previously proposed that a coating chromate treatment is performed on stainless steel as a pretreatment for applying a vulcanized adhesive to improve resistance to water, LLC, and the like. However, the coating-type chromate treatment is not preferable from the viewpoint of environmental measures because it contains Cr ⁶⁺ ions.
JP 2000-006307 A Japanese Patent Laid-Open No. 11-221875

  On the other hand, undercoats for various vulcanized adhesives based on phenolic resins are also commercially available, but do not exhibit sufficient adhesion and water resistance in bonding with stainless steel.

Therefore, the present applicant has further proposed various vulcanized adhesive compositions based on alkoxysilane as an adhesive between metal and rubber when producing a rubber-metal laminated gasket material. These vulcanized adhesive compositions are particularly suitable for bonding to metal surfaces that have been previously chemically or physically surface treated, but when applied to untreated metal surfaces, for example, coating chromate treatment. It is not possible to obtain the same adhesion as in the case of stainless steel subjected to.
JP 7-34054 A JP 7-216309 A JP-A-8-209102 Japanese Patent Laid-Open No. 9-3432 Japanese Patent Laid-Open No. 9-40916 JP-A-9-132758 Japanese Patent Laid-Open No. 10-7990 Japanese Patent Laid-Open No. 10-8021 Japanese Patent Application Laid-Open No. 11-1672 JP 2001-226642 A

Further, the present applicant sequentially laminated (A) a silane-based primer, (B) a novolac-type epoxy resin, a topcoat adhesive containing a phenol resin and a tertiary amine compound, and (C) a fluororubber on a metal plate. A rubber metal laminated gasket is proposed. The fluororubber metal laminated gasket constructed in this way shows excellent liquid resistance against heated water, ethylene glycol or its aqueous solution, alcohol, etc., but for various liquid resistance and heat resistance over a long period of time. There was still room for improvement.
JP 2004-76911 A

  Also, in the actual usage environment of gaskets, different metals are often in contact with the same liquid at the same time. In such a case, an electric potential is generated between the rubber-metal laminated gasket material and the different metals, facilitating adhesion peeling. However, a laminate of chromium-free stainless steel and fluororubber that does not cause adhesion peeling even under such an environment is desired. Further, when used as an engine cylinder head gasket, there is a high possibility of exposure to a high temperature environment, and heat resistant adhesiveness is also required at the same time.

  The object of the present invention is to form a rubber-metal laminated gasket material composed of a composite of a stainless steel plate and fluororubber. Water, LLC resistance, and heat resistance can be obtained without subjecting the metal to harmful coating-type chromate treatment. It is an object of the present invention to provide a fluororubber-metal laminated gasket material that does not cause adhesion peeling even in a water resistance test method and a heat resistance test method taking into account the actual use environment of an engine cylinder head gasket.

  An object of the present invention is to sequentially laminate a surface treatment agent layer containing an organometallic compound and silica, a silica-containing resin-based vulcanized adhesive layer, and a fluororubber layer, preferably an anti-adhesion layer, on a stainless steel plate. This is achieved by a fluororubber-metal laminated gasket material.

  The fluororubber-metal laminated gasket material according to the present invention has a laminated structure comprising a stainless steel plate, a surface treatment agent layer containing an organometallic compound and silica, a silica-containing resin-based vulcanized adhesive layer, and a fluororubber layer. Not only has excellent durability and resistance to water and LLC liquid, it also has excellent heat resistance. By laminating the fluororubber, the heat resistance is better than that of the nitrile rubber laminate, but the water resistance is deteriorated, so it is necessary to add silica to the vulcanized adhesive layer. The durability and resistance to water and LLC liquids are effective even when the gasket and the dissimilar metal are in contact with the same liquid, and there is no exfoliation due to the potential generated between the dissimilar metals. Shows adhesion.

  When using a composite of stainless steel and fluororubber in contact with an electrolyte such as water or LLC, if there is a corrosive metal such as aluminum or iron in the same liquid, We discovered a phenomenon in which an electric potential was generated in the metal and a corrosion reaction (anodic reaction) of these metals occurred, and at the same time a cathodic reaction occurred on the stainless steel surface of the composite, which caused adhesion peeling.

  As a prominent example of this phenomenon, when a fluororubber-stainless steel laminated gasket is used as the head gasket of an aluminum engine cylinder, it is compared with the one that was immersed in an electrolyte such as water or LLC solution under the same temperature conditions. Although it is confirmed that blistering and adhesion peeling occur in a short time, the gasket material according to the present invention causes adhesion peeling even when used in the electrolyte at the same time with different metals. It has the effect of not letting it go. At the same time, it has the heat resistance and LLC resistance necessary for an engine cylinder head gasket.

  As the stainless steel plate, SUS301, SUS301H, SUS304, SUS430, or the like is used. Since the plate thickness is used for gaskets, a thickness of about 0.1 to 2 mm is generally used. A surface treatment agent containing an organometallic compound and silica is first applied onto these stainless steel plates.

R：CH₃、C₂H₅、n-C₃H₇ 、i-C₃H₇、n-C₄H₉、i-C₄H₉、i-C₈H₁₇などの低
級アルキル基
R´：CH₃基またはOR
M₁：Ti、Zr、Sn
M₂：Al
n：0〜3の整数
m：0〜2の整数
で表される少くとも１個のアルコキシル基または少くとも１個のキレート環およびアルコキシル基を有する有機金属化合物、あるいは少くとも１個のキレート環を有する化合物と金属アルコキシドとの混合物が用いられる。有機金属化合物の中では、好ましくは有機チタン化合物が用いられ、有機金属化合物は１種または２種以上の混合物としても用いられる。 Examples of organometallic compounds include triisopropoxyaluminum, mono-sec-butoxydipropoxyaluminum, tri-sec-butoxyaluminum, tri (2-ethylhexyl) aluminum, diisopropoxyaluminum mono (methylacetoacetate), diisopropoxy Aluminum mono (ethyl acetoacetate), diisopropoxy aluminum mono (propyl acetoacetate), diisopropoxy aluminum mono (butyl acetoacetate), diisopropoxy aluminum mono (hexyl acetoacetate), di n-propoxy aluminum mono (methyl acetoacetate) Acetate), di-n-propoxy aluminum mono (ethyl acetoacetate), di-n-propoxy aluminum mono (propyl acetoacetate), di-n-propoxy aluminum mono (butyl acetoacetate) Cetate), di-n-propoxy aluminum mono (hexyl acetoacetate), dibutoxy aluminum mono (methyl acetoacetate), dibutoxy aluminum mono (ethyl acetoacetate), dibutoxy aluminum mono (propyl acetoacetate), dibutoxy aluminum mono ( Butyl acetoacetate), dibutoxy aluminum mono (hexyl acetoacetate), aluminum tris (ethyl acetoacetate), aluminum tris (propyl acetoacetate), aluminum tris (butyl acetoacetate), aluminum tris (hexyl acetoacetate), aluminum-mono Acetylacetonate-bis (ethylacetoacetate), aluminum tris (acetylacetonate), diisopropoxyaluminum mono (acetylacetonate) ), Etc., tetra i-propoxy titanium, tetra n-propoxy titanium, tetra n-butoxy titanium, tetra (2-ethylhexyl) titanate, diisopropoxy titanium bis (methyl acetoacetate), diisopropoxy titanium bis (ethyl aceto Acetate), diisopropoxy titanium bis (propyl acetoacetate), diisopropoxy titanium bis (butyl acetoacetate), diisopropoxy titanium bis (hexyl acetoacetate), di n-propoxy titanium bis (methyl acetoacetate), di n-propoxy titanium bis ( Ethyl acetoacetate), di-n-propoxy titanium bis (propyl acetoacetate), di-n-propoxy titanium bis (butyl acetoacetate), di-n-propoxy titanium bis (hexyl acetoacetate), di-n-butoxy titanium (Methyl acetoacetate), di-n-butoxytitanium bis (ethylacetoacetate), di-n-butoxytitanium bis (propylacetoacetate), di-n-butoxytitanium bis (butylacetoacetate), di-n-butoxytitanium bis (hexylacetoacetate) 1,3-propanedioxytitanium bis (ethylacetoacetate), diisopropoxytitanium bis (acetylacetonate), di-n-propoxytitanium bis (acetylacetonate), di-n-butoxytitanium bis (acetylacetonate), titanium tetraacetyl Organic titanium compounds such as acetonate, titanium tetraethyl acetoacetate, titanium tetrapropyl acetoacetate, titanium tetrabutyl acetoacetate, tetra i-propoxyzirconium, tetra n-propoxyzirconium, tetra n-butoxyzirconi Diisopropoxyzirconium bis (methylacetoacetate), diisopropoxyzirconium bis (ethylacetoacetate), diisopropoxyzirconium bis (propylacetoacetate), diisopropoxyzirconium bis (butylacetoacetate), diisopropoxyzirconium Bis (hexyl acetoacetate), di n-propoxyzirconium bis (methyl acetoacetate), di n-propoxyzirconium bis (ethyl acetoacetate), di n-propoxyzirconium bis (propyl acetoacetate), di n-propoxyzirconium bis ( Butyl acetoacetate), di-n-propoxyzirconium bis (hexyl acetoacetate), di-n-butoxyzirconium bis (methylacetoacetate), di-n-butoxyzirconium bis (ethylacetate) Cetate), di-n-butoxyzirconium bis (propylacetoacetate), di-n-butoxyzirconium bis (butylacetoacetate), di-n-butoxyzirconium bis (hexylacetoacetate), 1,3-propanedioxyzirconium bis (ethyl Acetoacetate), diisopropoxyzirconium bis (acetylacetonate), di-n-propoxyzirconium bis (acetylacetonate), di-n-butoxyzirconium bis (acetylacetonate), zirconium tetraacetylacetonate, zirconium tetraethylacetoacetate, Organic zirconium compounds such as zirconium tetrapropyl acetoacetate and zirconium tetrabutyl acetoacetate, tetra i-propoxy tin, tetra n-propoxy tin, tetra n-butoxy tin, diisopropoxy Bis (methylacetoacetate), diisopropoxytin bis (ethylacetoacetate), diisopropoxytin bis (propylacetoacetate), diisopropoxytin bis (butylacetoacetate), diisopropoxytin bis (hexylacetoacetate) Di n-propoxytin bis (methyl acetoacetate), Di n-propoxytin bis (ethyl acetoacetate), Di n-propoxytin bis (propyl acetoacetate), Di n-propoxytin bis (butyl acetoacetate), Di n-propoxy tin bis (hexyl acetoacetate), di n-butoxy tin bis (methyl acetoacetate), di n-butoxy tin bis (ethyl acetoacetate), di n-butoxy tin bis (propyl acetoacetate), di n- Butoxytin bis (butyl acetoacetate), di-n-butoxytin bis (hexyl acetoacetate) 1,3-propanedioxytin bis (ethylacetoacetate), diisopropoxytin bis (acetylacetonate), di-n-propoxytin bis (acetylacetonate), di-n-butoxytin bis (acetylacetonate) , Organic tin compounds such as tin tetraacetylacetonate, tin tetraethyl acetoacetate, tin tetrapropyl acetoacetate, tin tetrabutyl acetoacetate, dibutyltin dilaurate, dibutyltin dioctate, dioctyltin dilaurate, and the like. Two general formulas

_{R: CH 3, C 2 H} 5, nC 3 H 7, iC 3 H 7, nC 4 H 9, iC 4 H 9, low, such as iC ₈ H ₁₇
Secondary alkyl group
R´: CH ₃ group or OR
M ₁ : Ti, Zr, Sn
M ₂ : Al
n: Integer from 0 to 3
m: at least one alkoxyl group represented by an integer of 0 to 2 or an organometallic compound having at least one chelate ring and an alkoxyl group, or a compound having at least one chelate ring and a metal alkoxide; A mixture of Among the organometallic compounds, an organotitanium compound is preferably used, and the organometallic compound is also used as one kind or a mixture of two or more kinds.

Silica (silicon oxide) is a dispersion of dry or wet silica having an SiO ₂ content of 85% or more in an organic solvent or water, preferably high-purity anhydrous silica fine particles in an organic solvent or water. So-called colloidal silica dispersed in colloidal form is used. The colloidal silica has an average particle diameter of 1 to 50 nm, preferably 10 to 30 nm, and is dispersed in an organic solvent such as methanol, methyl ethyl ketone, or methyl isobutyl ketone. Methanol silica sol (Nissan Chemical Industries product: Dispersed in methanol at a solid concentration of 30% by weight), Snowtex MEK-ST (Company product: Dispersed in methyl ethyl ketone at a solid content of 30% by weight), Snowtex MIBK -ST (Company product; dispersed in methyl isobutyl ketone at a solid content of 30% by weight) is used.

  The organometallic compound and silica are used in a weight ratio of 70:30 to 40:60 in terms of solid content, particularly for gasket applications. Here, the solid content of the organometallic compound is an evaporation residue when this is evaporated to dryness at 135 ° C. for 1 hour, and is an index of the amount of the organometallic compound remaining on the substrate when actually surface-treated. Amount. Moreover, it prepares as an organic-solvent solution so that these solid content concentration may become about 0.01-5 weight%. When silica is used in a proportion higher than 60%, the heat resistance is lowered, and adhesion peeling occurs in a bending test after heating with high temperature air. On the other hand, when silica is used in a proportion of less than 30%, the liquid durability against water, LLC and the like deteriorates. Examples of the organic solvent include alcohols such as methanol, ethanol and isopropanol, ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone, polyhydric alcohols such as ethylene glycol monomethyl ether, monoethyl ether, monobutyl ether and monoethyl ether acetate, Its derivatives are used.

The surface treatment agent comprising the above components as essential components is 10 to 1000 mg / m ² , preferably 50 to 500 mg / m ² by immersion, spraying, brush printing, roll coating or the like on a stainless steel plate subjected to alkali degreasing treatment. It is applied with a m ² one-side weight (film amount), dried at room temperature or warm air, and then baked at 100 to 250 ° C. for 0.5 to 20 minutes.

A silica- containing resin-based vulcanized adhesive is applied on the surface treatment agent layer applied on the stainless steel plate and subjected to the drying treatment. As the silica- containing resin-based vulcanized adhesive, a vulcanized adhesive containing silica and a thermosetting resin, preferably a thermosetting phenol resin as an essential component is used. As the silica, those described above, preferably colloidal silica, are used, and as the thermosetting phenol resin, a resol type phenol resin or a phenol resin having a dihydrobenzoxazine ring is preferably used. Other thermosetting resins such as a novolac type phenol resin and an epoxy resin can be used in combination with the phenol resin.

  Resol-type phenol resins include 2 or 3 substitutable nuclei in the o-position and / or p-position with respect to phenolic hydroxyl groups such as phenol, p-cresol, m-cresol, and p-tert-butylphenol. The softening point obtained by subjecting phenols having a hydrogen atom or a mixture thereof and formaldehyde to a condensation reaction in the presence of an alkali catalyst such as sodium hydroxide, sodium carbonate, barium hydroxide, and ammonia is about 80 to 150 ° C. A resin having a softening point of 100 ° C. or higher produced from m-cresol, a p-cresol mixture and formaldehyde is preferably used.

In addition, as the thermosetting phenol resin having a dihydrobenzoxazine ring, any thermosetting phenol resin having a dihydrobenzoxazine ring and being cured by a ring-opening reaction of the dihydrobenzoxazine ring should be used. For example, a dihydro-2H-1,3-benzoxazine derivative is synthesized from a compound having a phenolic hydroxyl group, a primary amine and formaldehyde, as shown in the following formula.

  The compound having a phenolic hydroxyl group needs to have a hydrogen atom bonded to at least one o-position with respect to the phenolic hydroxyl group of the aromatic ring, and preferably a plurality of phenolic hydroxyl groups in the molecule. Existing multifunctional phenols are used. Specifically, phenols such as catechol, resorcinol and hydroquinone, dihydroxynaphthalenes such as 1,5-dihydroxynaphthalene and 2,6-dihydroxynaphthalene, bisphenols such as bisphenol A and bisphenol F, novolac type or resole type phenol Examples thereof include phenol resins such as resins, melamine phenol resins and alkylphenol resins.

  Examples of primary amines include aromatic amines such as aniline and toluidine, and aliphatic amines such as methylamine and ethylamine.

  Two moles or more of formaldehyde is used for each mole of the compound having a phenolic hydroxyl group and the primary amine, and the reaction temperature is about 70 to 130 ° C., preferably about 90 in the presence of an oxalic acid catalyst. After reacting at ~ 110 ° C for about 1/3 to 4 hours, remove the unreacted phenolic compounds, primary amines, formaldehyde, etc. under reduced pressure at 120 ° C or less, and heat with dihydrobenzoxazine ring A curable resin is obtained.

  By using fluororubber as the rubber laminated on the stainless steel plate, the heat resistance is better than that of the metal material laminated with nitrile rubber, but the water resistance is reduced. Since it does not hold, it is necessary to add silica to the top coat adhesive.

  From this point of view, about 10 to 100 parts by weight, preferably about 15 to 40 parts by weight of silica is added to 100 parts by weight of the thermosetting resin component. When the addition ratio of silica is smaller than this, the water resistance is lowered. On the other hand, when silica is added at a larger ratio, the initial adhesiveness is lowered.

  In addition, as the thermosetting resin used as this weight standard, it is 0 to 500 parts by weight, preferably about 50 to 200 parts by weight per 100 parts by weight of the thermosetting phenol resin, such as novolac type phenol resin, epoxy resin, etc. What added the other thermosetting resin, or what added fluororubber or fluororubber compound (as fluororubber component) in the ratio of 0-500 weight part, Preferably about 50-150 weight part is used. The addition of a novolac type phenol resin or an epoxy resin is effective for further improving the heat resistance. However, the addition at a ratio higher than this reduces the initial adhesiveness. Further, the addition of fluororubber (compound) is also effective for further improving the heat resistance, but the addition at a higher ratio leads to a decrease in water resistance.

These silica-containing resin-based vulcanized adhesives generally have an alcohol organic solvent such as methanol, ethanol, and isopropanol, or a ketone organic solvent such as acetone, methyl ethyl ketone, and methyl isobutyl ketone, either alone or as a mixed solvent. Prepared as an organic solvent solution of 0.1 to 10% by weight, applied with a surface weight per unit area (film amount) of 50 to 2000 mg / m ² by the same coating method as the surface treatment agent, and dried at room temperature or hot air Thereafter, baking is performed at 100 to 250 ° C. for 1 to 20 minutes.

  On the vulcanized adhesive layer thus formed, an unvulcanized fluororubber compound is formed on both sides so that a vulcanizate layer having a thickness of about 5 to 120 μm on one side is formed on both sides. It is applied as an organic solvent solution.

  As the fluororubber, both polyol vulcanizability and peroxide vulcanizability can be used. Examples of the unvulcanized fluororubber compound include the following blending examples.

  As the polyol vulcanizable fluoro rubber, generally vinylidene fluoride and other fluorine-containing olefins such as hexafluoropropene, pentafluoropropene, tetrafluoroethylene, trifluorochloroethylene, vinyl fluoride, perfluoro (methyl vinyl ether), etc. Examples of such a fluororubber include 2,2-bis (4-hydroxyphenyl) propane, 2,2-bis (4- Polyol is vulcanized with polyhydroxy aromatic compounds such as (hydroxyphenyl) perfluoropropane and hydroquinone.

  Examples of the peroxide vulcanizable fluororubber include fluororubbers having iodine and / or bromine in the molecule, and these fluororubbers are added by organic peroxides generally used for peroxide vulcanization. Sulfurized (crosslinked). In this case, it is preferable to use a polyfunctional unsaturated compound represented by triallyl isocyanurate together with the organic peroxide.

(Formulation example I)
Fluoro rubber (DuPont product Viton E45) 100 parts by weight Calcium metasilicate 40 部
MT carbon black 2 〃
Magnesium oxide (Kyowa Chemical Product Magnesia # 150) 6 〃
Calcium hydroxide 3 〃
Vulcanizing agent (DuPont product curative # 30) 2 〃
Vulcanization accelerator (the company's product curative # 20) 1〃
(Composition Example II)
Fluoro rubber (DuPont Viton E60C) 100 parts by weight Vulcanizing agent (DuPont Diac No. 3) 3 〃
Magnesium oxide (Kyowa Chemical Product Magnesia # 30) 10 〃
MT carbon black 30 〃
(Composition Example III)
Fluororubber (Daikin product Daiel G901) 100 parts by weight Calcium metasilicate 20 〃
MT carbon black 20 〃
Magnesium oxide (magnesia # 150) 6 〃
Calcium hydroxide 3 〃
Triallyl isocyanurate 1.8 〃
Organic peroxide (NIPPON OIL & PRODUCTS PERHEXA 25B) 0.8 〃

  The applied unvulcanized rubber layer is dried at a temperature of room temperature to about 100 ° C. for about 1 to 15 minutes, and alcohols such as methanol and ethanol used as an organic solvent, and ketones such as methyl ethyl ketone and methyl isobutyl ketone Or after volatilizing these mixed solvents etc., it vulcanizes by heating at about 150-230 degreeC for about 0.5-30 minutes, and pressurizing as needed and vulcanizing. For use as a gasket, the vulcanized fluoro rubber layer preferably has a hardness (durometer A) of 80 or more and a compression set (100 ° C., 22 hours) of 50% or less, especially limited by the content of the compound. Is not to be done. Moreover, when it is necessary to prevent adhesion, an anti-adhesive agent can be applied to the surface.

The anti-sticking agent can be used for the purpose of preventing sticking between rubbers or between rubber and metal, and any anti-sticking agent can be used as long as it can form a film on the vulcanized fluoro rubber layer. , Fluorine-based, graphite-based, amide, paraffin-based wax-based, polyolefin-based or polybutadiene-based materials, etc., preferably liquid 1,2-polybutadiene hydroxyl group-containing materials, 1,2-polybutadiene isocyanate group-containing materials And an anti-adhesive agent comprising an organic solvent dispersion of polyolefin resin.
Japanese Patent Laid-Open No. 7-165953

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

Examples 1-105
After alkali degreasing the surface of SUS301 steel plate (thickness 0.2 mm), surface treatment agent 1-21 consisting of the following ingredients was applied so that the coating amount (weight per side) was 120 mg / m ^2, and 1 at 200 ° C. Drying for a minute was performed.

Next, vulcanized adhesives A to E having the following compositions were applied, dried at room temperature, and then baked at 220 ° C. for 5 minutes.
(Vulcanized adhesive A)
Resole type phenolic resin 47% methyl ethyl ketone solution 100 parts by weight
(Gunei Chemical Product Resid Top PL2108)
Colloidal silica 30% methyl ethyl ketone solution 47 〃
(Nissan Chemical Product MEK-ST)
Methyl ethyl ketone 1075 〃

(Vulcanized adhesive B)
Thermosetting resin with dihydrobenzoxazine ring 100 〃
Resole-type phenolic resin 47% methyl ethyl ketone solution 600 〃
(Resitop PL2108)
Colloidal silica 30% methyl ethyl ketone solution (MEK-ST) 382 〃
Methyl ethyl ketone 8850 〃

(Vulcanized adhesive C)
Resole-type phenolic resin 47% methyl ethyl ketone solution 100 〃
(Resitop PL2108)
o-Cresol novolac epoxy resin 47 〃
(Japan Epoxy Resin Product Epicoat 180S)
Colloidal silica 30% methyl ethyl ketone solution (MEK-ST) 94 〃
Methyl ethyl ketone 2203 〃

(Vulcanized adhesive D)
Thermosetting resin with dihydrobenzoxazine ring 100 〃
o-Cresol novolac epoxy resin (Epicoat 180S) 100 〃
Colloidal silica 30% methyl ethyl ketone solution (MEK-ST) 200 〃
Methyl ethyl ketone 6000 〃

(Vulcanized adhesive E)
Thermosetting resin with dihydrobenzoxazine ring 100 〃
o-Cresol novolac epoxy resin (Epicoat 180S) 100 〃
Colloidal silica 30% methyl ethyl ketone solution (MEK-ST) 200 〃
Fluoro rubber compound of compounding example 100 100 〃
Methyl ethyl ketone 6700 〃

In addition, the thermosetting resin which has the dihydrobenzoxazine ring used here was synthesize | combined as follows.
Charge 500 g of phenol, 302.5 g of 37% formalin and 1 g of oxalic acid into a 5 L flask, react at reflux temperature for 6 hours, and then depressurize the inside to remove unreacted phenol and moisture, novolac type phenol resin Got. 300 g of this novolac type phenol resin was mixed with 263 g of aniline and stirred at 80 ° C. for 5 hours to obtain a uniform mixed solution. This mixed solution was dropped in a small amount over a period of 30 minutes into a 5 L flask charged with 286 g of formalin heated to 90 ° C., kept at the reflux temperature for 30 minutes after completion of the dropping, and then reduced in pressure at 100 ° C. for 2 hours. The condensed water was removed to obtain a thermosetting resin having a dihydrobenzoxazine ring.

Surface treatment agent coating On the vulcanized adhesive layer on the SUS301 steel plate, a 25% by weight mixed organic solvent solution (toluene: methyl ethyl ketone = weight ratio 9: 1) of fluororubber compound (formulation example I) was applied, and 60 ° C. , And dried for 15 minutes to form an unvulcanized rubber layer with a thickness of 20μm on one side, followed by pressure vulcanization for 2 minutes at 220 ° C, 60kgf / m ² (5.88MPa) I got the material.

Organometallic compounds used as surface treating agent components
(See the above general formula; including comparative examples):
Organometallic compound structure solids
Symbol M R R ′ n m (% by weight)
_{A Ti iC 3 H 7 - 0} - 40
B 〃 C ₄ H ₉ - 0 - 40
C 〃 C ₈ H ₁₇ - 0 - 40
D 〃 iC ₃ H ₇ OC ₂ H ₅ 2-42.10
E 〃 〃 CH ₃ 2-62.70
F Al 〃 OC ₂ H ₅ - ₂ 42
G 〃 C ₄ H ₉ - - 0 40
H Zr 〃-0-40
I 〃 〃 OC ₂ H ₅ 3-42
J 〃 〃 CH ₃ 2-63
K Ti-OC ₂ H ₅ 4-40
L 〃-CH ₃ 4-36.20
Note) Here, the solid content refers to the amount of evaporation residue when the organometallic compound is evaporated to dryness at 135 ° C for 1 hour. The solid content of the organometallic compound differs depending on the structure, but it is about 30% to 70% by weight (the organometallic compound component itself is almost in liquid form and solidifies by heating to cause a condensation reaction, and the portion that has not caused the condensation reaction evaporates. The remaining solid content accounts for about 30 to 70% of the organometallic compound component before heating, but the remaining solid content is determined by the balance between the condensation reaction rate and the evaporation rate. (Solid content varies depending on the type and structure of the metal compound)

Surface treatment agent composition (Nos. 22 to 27 are comparative examples):
Surface treatment Organometallic Silica sol, blending amount (parts by weight) Component ratio Solid content
Agent No. Compound Solvent Organometallic Silica Solvent Ratio (%) Ratio (%)
1 A IPA 100 90 6510 79:21 60:40
2 B 〃 〃 〃 〃 〃 〃
3 C 〃 〃 〃 〃 〃 〃
4 D 〃 〃 92 6778 〃 〃
5 〃 MeOH 〃 〃 〃 〃 〃
6 〃 IPA 〃 188 13657 〃 〃
A 105 〃
7 E MeOH 100 140 10330 42:58 〃
8 〃 IPA 〃 280 20413 75:25 〃
A 157 〃
9 F MeOH 100 80 6420 80:20 〃
10 G IPA 〃 〃 6220 〃 〃
11 H 〃 〃 90 6510 79:21 〃
12 I 〃 〃 〃 〃 〃 〃
13 J 〃 〃 〃 〃 〃 〃
14 A 〃 〃 30 4770 85:15 70:30
15 〃 〃 〃 178 9062 65:35 43:57
16 D MeOH 〃 32 5038 85:15 70:30
17 〃 〃 〃 188 9562 64:36 43:57
18 〃 IPA 〃 62 10042 85:15 70:30
A 106
19 D 〃 100 374 19051 65:35 43:57
A 105
20 K MeOH 100 92 6568 79:21 60:40
21 L 〃 〃 84 5956 80:20 59:41

22 A (IPA) 〃 − 3900 100: 0 100: 0
23 〃 IPA 〃 45 5205 88:12 75:25
24 〃 〃 〃 311 12919 52:48 30:70
25 D (MeOH) 〃 − 4110 88:12 100: 0
26 〃 MeOH 〃 46 5464 〃 75:25
27 〃 〃 〃 327 12873 52:48 30:70
Note 1) In the silica sol / solvent column, IPA indicates that isopropanol silica sol (Nissan Chemical Industries product) and isopropanol solvent were used, and MeOH was methanol silica sol (the company's product) and methanol solvent. (However,
(No. 22, 25 do not use silica, only the type of solvent is shown)
Note 2) The component ratio indicates the weight ratio between the organometallic compound and the silica solid content in the surface treatment agent. Note 3) The solid content ratio is the organometallic compound solid content and the silica content in the surface treatment agent. Indicates the weight ratio to the solid content

Comparative Examples 1-6
In Examples 1-21, those No. 22-27 were used as the surface treatment agent.

Comparative Example 7
In Examples 1 to 21, the following compound was used as the surface treatment agent 28.
100 parts by weight of diisopropoxy titanium bis (ethyl acetoacetate) γ-aminopropyltriethoxysilane 50 〃
Methanol 6350 〃

Comparative Example 8
In Examples 1 to 21, the following compound was used as the surface treatment agent 29.
100 parts by weight of diisopropoxy titanium bis (ethyl acetoacetate) γ-aminopropyltriethoxysilane 50 〃
Methanol silica sol 80 〃
Methanol 8670 〃

Comparative Example 9
In Examples 1 to 21, the following compound was used as the surface treatment agent 30.
Diisopoxytitanium bis (ethyl acetoacetate) 100 parts by weight Copolymeric oligomer 100 〃
Methanol silica sol 80 〃
Methanol 8120 〃

In addition, the copolymerization oligomer used here was synthesize | combined as follows.
A three-necked flask equipped with a stirrer, 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 reaches 4-5. Stir for minutes. While further stirring, 40 parts by weight of vinyltriethoxysilane was gradually added using a dropping funnel, and after completion of the addition, the mixture was heated to reflux at about 60 ° C. for 5 hours and cooled to room temperature to obtain a silane copolymer oligomer. .

Comparative Example 10
In Examples 1 to 21, the surface treatment agent 31 having the following composition was used.
Copolymer oligomer 100 parts by weight Methanol silica sol 80 部
Methanol 4720 〃

Comparative Example 11
In Examples 1 to 21, the following compound was used as the surface treatment agent 32.
100 parts by weight of the silane copolymer oligomer Methanol 2400

Comparative Examples 12-17
In Examples 85-105, the above-mentioned No. 22-27 were used as the surface treatment agent.

Comparative Example 18
In Examples 85 to 105, the surface treatment agent No. 28 was used.

Comparative Example 19
In Examples 85 to 105, the surface treatment agent No. 29 was used.

Comparative Example 20
In Examples 85 to 105, the surface treatment agent of No. 30 was used.

Comparative Example 21
In Examples 85 to 105, the surface treatment agent No. 31 was used.

Comparative Example 22
In Examples 85 to 105, the surface treatment agent No. 32 was used.

Comparative Examples 23-43
In Examples 1 to 21, vulcanized adhesive F was used as the vulcanized adhesive .
(Vulcanized adhesive F)
100 parts by weight of thermosetting resin having dihydrobenzoxazine ring
o-Cresol novolac epoxy resin (Epicoat 180S) 100 〃
Fluoro rubber compound 100 of formulation example I
Methyl ethyl ketone 5700 〃

The gasket materials obtained in the above Examples and Comparative Examples were subjected to a water resistance test, an LLC resistance test, and a heat resistance test.
Water resistance test: In a 1% by weight sodium bicarbonate aqueous solution at 95 ° C in a glass container for 70 hours, hold the rubber-metal laminated gasket material and aluminum plate with an inverted V-shaped clip with a clip etc. Dipping test is performed so that the vicinity of the top is located above the liquid level, and the rubber metal laminate at the contact part is scraped off and the stainless steel plate part is in direct contact with the aluminum plate. After the test, a gobang eye peel test (JIS K5600-5-6 coating adhesion test method = cross-cut method = compliant) was performed. This immersion test was an immersion test that considered the potential difference between different metals. Yes , and proposed by the present applicant (Japanese Patent Laid-Open No. 2005-49257)
LLC resistance test: A rubber-metal laminated gasket material is immersed in a 50% by weight LLC (Nippon Chemical Industrial Products JCC310) aqueous solution at 150 ° C for 100 hours, and then a Gobang eye peel test (JIS K5600-5-6 film adhesion) Test method = cross-cut method = compliant)
[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.
Heat resistance test for any degree of peeling that cannot be classified even in 5 classification 4 : After exposing rubber-metal laminated gasket material to air heating at 165 ° C for 100 hours, using a 4mm diameter mandrel (JIS K5600- 5-1)) and evaluated according to the following criteria: Rating 5: No cracking or peeling 〃 4: Small cracks on the end surface 〃 3: Overall small cracks 〃 2: Overall cracks 〃 1: Completely peeled

The results obtained are shown in the following table.
table
Surface vulcanization
Examples Treatment agent Adhesive water resistance test LLC resistance test Heat resistance test Example 1 1 A 0 0 4
〃 2 2 ０ 0 0 4
３ 3 3 ０ 0 0 4
〃 4 4 〃 0 0 4
〃 5 5 〃 0 0 4
６ 6 6 〃 0 0 4
７ 7 7 〃 1 0 4
〃 8 8 ０ 0 0 4
９ 9 9 〃 0 0 4
〃 10 10 ０ 0 0 4
〃 11 11 〃 1 0 4
〃 12 12 １ 1 1 4
〃 13 13 〃 2 1 4
〃 14 14 ０ 0 0 4
〃 15 15 ０ 0 0 4
〃 16 16 ０ 0 0 4
〃 17 17 〃 0 0 4
〃 18 18 ０ 0 0 4
〃 19 19 ０ 0 0 4
〃 20 20 〃 1 1 3
〃 21 21 〃 2 1 3
〃 22 1 B 0 0 5
〃 23 2 〃 0 0 5
〃 24 3 〃 0 0 5
〃 25 4 〃 0 0 5
〃 26 5 ０ 0 0 5
〃 27 6 〃 0 0 5
〃 28 7 〃 1 0 5
〃 29 8 ０ 0 0 5
〃 30 9 ０ 0 0 5
〃 31 10 〃 0 0 5
〃 32 11 〃 1 0 5
〃 33 12 〃 1 1 5
〃 34 13 〃 1 1 4
〃 35 14 ０ 0 0 5
〃 36 15 〃 0 0 5
〃 37 16 〃 0 0 5
〃 38 17 〃 0 0 5
〃 39 18 〃 0 0 5
〃 40 19 〃 0 0 5
〃 41 20 〃 1 1 4
〃 42 21 〃 2 1 4
〃 43 1 C 0 0 5
〃 44 2 〃 0 0 5
〃 45 3 〃 0 0 5
〃 46 4 ０ 0 0 5
〃 47 5 ０ 0 0 5
〃 48 6 〃 0 0 5
〃 49 7 〃 1 0 5
〃 50 8 〃 0 0 5
〃 51 9 ０ 0 0 5
〃 52 10 ０ 0 0 5
〃 53 11 〃 1 0 5
〃 54 12 〃 1 1 5
〃 55 13 〃 1 1 4
〃 56 14 〃 0 0 5
〃 57 15 ０ 0 0 5
〃 58 16 〃 0 0 5
〃 59 17 〃 0 0 5
〃 60 18 ０ 0 0 5
〃 61 19 〃 0 0 5
〃 62 20 〃 1 1 4
〃 63 21 〃 2 1 4
〃 64 1 D 0 0 5
〃 65 2 〃 0 0 5
〃 66 3 ０ 0 0 5
〃 67 4 〃 0 0 5
〃 68 5 〃 0 0 5
〃 69 6 ０ 0 0 5
〃 70 7 〃 1 0 5
〃 71 8 ０ 0 0 5
〃 72 9 〃 0 0 5
〃 73 10 〃 0 0 5
〃 74 11 〃 1 0 5
〃 75 12 １ 1 0 5
〃 76 13 〃 1 1 5
〃 77 14 〃 0 0 5
〃 78 15 〃 0 0 5
〃 79 16 〃 0 0 5
〃 80 17 〃 0 0 5
〃 81 18 ０ 0 0 5
〃 82 19 〃 0 0 5
〃 83 20 ０ 0 0 5
〃 84 21 〃 1 1 5
〃 85 1 E 0 0 5
〃 86 2 〃 0 0 5
〃 87 3 〃 0 0 5
〃 88 4 ０ 0 0 5
〃 89 5 ０ 0 0 5
〃 90 6 〃 0 0 5
〃 91 7 １ 1 0 5
〃 92 8 ０ 0 0 5
〃 93 9 ０ 0 0 5
〃 94 10 〃 0 0 5
〃 95 11 〃 1 0 5
〃 96 12 １ 1 0 5
〃 97 13 〃 2 1 5
〃 98 14 〃 0 0 5
〃 99 15 ０ 0 0 5
〃 100 16 〃 0 0 5
〃 101 17 〃 0 0 5
〃 102 18 〃 0 0 5
〃 103 19 〃 0 0 5
〃 104 20 〃 1 0 5
〃 105 21 〃 2 1 5
Comparative Example 1 22 A 5 5 4
〃 2 23 ４ 4 5 4
３ 3 24 〃 0 0 2
４ 4 25 〃 5 5 4
〃 5 26 〃 5 5 4
６ 6 27 ０ 0 0 1
７ 7 28 ５ 5 5 4
８ 8 29 ４ 4 3 3
９ 9 30 ３ 3 3 3
〃 10 31 ４ 4 4 5
〃 11 32 〃 5 5 5
〃 12 22 E 5 5 5
〃 13 23 〃 4 5 5
〃 14 24 〃 0 0 3
〃 15 25 〃 5 5 5
〃 16 26 〃 5 5 5
〃 17 27 〃 0 0 2
〃 18 28 〃 5 5 5
〃 19 29 ４ 4 3 5
〃 20 30 〃 3 3 5
〃 21 31 ４ 4 4 5
〃 22 32 〃 5 5 5
〃 23 1 F 5 4 5
〃 24 2 〃 5 4 5
〃 25 3 〃 5 4 5
〃 26 4 〃 5 4 5
〃 27 5 〃 5 4 5
〃 28 6 〃 5 4 5
〃 29 7 〃 5 4 5
〃 30 8 〃 5 4 5
〃 31 9 ５ 5 4 5
〃 32 10 〃 5 4 5
〃 33 11 ５ 5 4 5
〃 34 12 〃 5 5 5
〃 35 13 〃 5 5 5
〃 36 14 〃 5 4 5
〃 37 15 〃 5 4 5
〃 38 16 〃 5 4 5
〃 39 17 〃 5 4 5
〃 40 18 〃 5 4 5
〃 41 19 ５ 5 4 5
〃 42 20 〃 5 5 5
〃 43 21 〃 5 5 5

Comparative Examples 3, 6, 14, and 17 are inferior in terms of heat resistance evaluation (1 to 3), although there is no problem with water resistance.

Claims (13)

  A fluororubber-metal laminated gasket material obtained by sequentially laminating a surface treatment agent layer containing an organometallic compound and silica, a silica-containing resin-based vulcanized adhesive layer, and a fluororubber layer on a stainless steel plate.   2. The fluororubber-metal laminated gasket material according to claim 1, wherein the silica is colloidal silica.   The fluororubber-metal laminated gasket material according to claim 1 or 2, wherein the organometallic compound forming the surface treatment agent layer and silica are used in a weight ratio of 70:30 to 40:60 as a solid content ratio.   4. The fluororubber-metal laminated gasket material according to claim 1, wherein the organometallic compound is a compound having at least one alkoxyl group.   The fluororubber-metal laminated gasket material according to claim 1 or 3, wherein the organometallic compound is a compound containing at least one chelate ring and an alkoxyl group.   4. The fluororubber-metal laminated gasket material according to claim 1, wherein the organometallic compound is a mixture of a compound having at least one chelate ring and a metal alkoxide.   7. The fluororubber-metal laminated gasket material according to claim 1, wherein the organometallic compound is an organotitanium compound.   2. The fluororubber-metal laminated gasket material according to claim 1, wherein the silica-containing resin-based vulcanized adhesive is a vulcanized adhesive containing silica and a thermosetting resin as essential components.   9. The fluororubber-metal laminated gasket material according to claim 8, wherein the thermosetting resin is a resol type phenol resin. Fluororubber according to claim 8, wherein the thermosetting resin is a thermosetting phenolic resin having a dihydrobenzoxazine ring - metal laminate gasket material.   The fluorine according to claim 8, 9 or 10, wherein a silica-containing resin vulcanized adhesive to which silica is added at a ratio of 10 to 100 parts by weight per 100 parts by weight of a thermosetting resin containing a thermosetting phenol resin is used. Rubber-metal laminated gasket material.   The fluororubber-metal laminated gasket material according to claim 1, wherein an anti-adhesive agent layer is further laminated on the fluororubber layer. The fluororubber-metal laminated gasket material according to any one of claims 1 to 12, which is used as an engine cylinder head gasket.