JPH0670211B2 - Vulcanizing adhesive for NBR and metal - Google Patents

Description

TECHNICAL FIELD The present invention relates to a vulcanizing adhesive of NBR and a metal. More specifically, it relates to a vulcanization adhesive of NBR made of a phenol resin system and a metal.

[Conventional technology]

Conventionally, a phenol resin adhesive is used as a vulcanizing adhesive between NBR and a metal, but when a phenol resin vulcanizing adhesive is used, unless a proper baking treatment is performed, There was a drawback that the adhesive layer was softened and flowed by heat and pressure during vulcanization, and the adhesive purpose could not be achieved sufficiently.

[Problems to be solved by the invention]

If such softening and flow of the adhesive layer can be prevented, the excellent adhesiveness originally possessed by the phenol resin adhesive will be sufficiently exhibited. It has been found that adding at least one of a specific polymer substance and a granular inorganic substance to this is an effective solution in order to prevent softening and flow of the substance.

[Means for Solving Problems] and [Action] Therefore, the present invention relates to a vulcanizing adhesive of NBR and a metal, and the vulcanizing adhesive is used as a novolak-type phenol resin and a curing agent thereof. Hexamethylenetetramine,
(A) a polymer substance having a softening temperature of about 100 to 200 ° C., (b) a polymer substance having a viscosity (25 ° C.) of about 10 ³ poise or more, and (c) a granular inorganic substance having a particle size of about 1 to 100 μm. At least one is added.

The novolak type phenol resin is a soluble and fusible phenol-formaldehyde resin obtained by condensing 1 mol of phenol and less than 1 mol of formaldehyde using an acid as a catalyst, and its softening temperature is generally about 80 to 100
℃. Novolac molecule is a reactive group (methylol group)
Since it does not have, it does not cause condensation between molecules by simply heating and permanently maintains thermoplasticity, but when formaldehyde or hexamethylenetetramine is added as a methylene group source for curing and heating is performed. It becomes insoluble and infusible, but before such a state, the adhesive layer softens and flows due to heat and pressure during vulcanization adhesion, and forms the cause of peeling of the adhesive layer. Addition of at least one of the above components effectively eliminates the cause of such defects.

As the polymer substance having a softening temperature of about 100 to 200 ° C. of the component (a), for example, an epoxy resin, a polyurethane resin, a polyamine resin, an acrylamide resin, an amine-modified phenol resin or the like is used. Examples of the polymer substance having a viscosity of component (b) (25 ° C .; measured with a Koka type flow tester) of about 10 ³ poise or more include poly-2-chlorobutadiene, polymethyl methacrylate, potyethyl acrylate, polybutyl. Acrylate, polyvinyl butyral,
Polyvinyl chloride, acrylic resin, ethylene-vinyl acetate copolymer resin, etc. are used. Further, as the particulate inorganic substance having a particle diameter of the component (c) of about 1 to 100 μm, carbon black, silica, talc, calcium carbonate, magnesium oxide, zinc oxide, titanium oxide, lead oxide, diatomaceous earth and the like are used. . It should be noted that those belonging to both the above components (a) and (b) are also used, and for example, a polyamide resin or the like corresponds to this.

Each of these components is used in a proportion of about 5 to 50 parts by weight per 100 parts by weight of the novolak type phenol resin together with about 5 to 20 parts by weight of hexamethylenetetramine. Above (a)
In the case of the component (b), these are dissolved in a soluble solvent typified by a ketone, a ketone-alcohol mixed system, a ketone-hydrocarbon mixed system, etc. at a solid content concentration of about 3 to 20%, Further, in the case of the component (c), this is kneaded into a novolak-type phenol resin in advance with a hot roll, the kneaded compound is dissolved in the soluble solvent, and hexamethylenetetramine is further added as a curing agent to 100 weight of the novolak-type phenol resin. It is added at a rate of about 5 to 20 parts by weight per part.

For vulcanization adhesion, generally, after applying such a vulcanization adhesive to the metal material surface side, it is dried at room temperature to about 80 ° C for about 10 minutes to remove the solvent, and then the NBR material is adhered to it. It is done by the method.

〔The invention's effect〕

The vulcanized adhesive according to the present invention, when used for bonding NBR and a metal, can be used without baking treatment, and at that time, the softening and flow of the adhesive are not observed, and therefore the phenol is used. The adhesive performance originally possessed by the system adhesive is sufficiently exhibited.

Therefore, the vulcanizing adhesive of the present invention is applied to NBR made of mild steel plate.
It can be effectively used for manufacturing baked oil seals, valves, gaskets, packings and the like.

〔Example〕

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

Example 1 Epoxy resin dissolved in a mixed solvent of novolak type phenol resin (softening temperature 90 ° C.) 100 parts (weight, the same hereinafter), hexamethylene tetramine 10 parts and methyl ethyl ketone-methanol (1: 1) at a solid content concentration of 10%. An NBR molded product and a metal were bonded using an adhesive consisting of 20 parts of resin (epoxy equivalent of 3000 or more, softening temperature 150 ° C).

NBR molded product: NBR (Nippon DN201 manufactured by Zeon Corporation) 100 parts, FEF carbon black 50 parts, zinc oxide 5 parts, stearic acid 1 part, sulfur 0.8 parts, vulcanization accelerator (tetramethyl thiuram disulfide) 2 parts and Using 2.5 parts of the same (N-cyclohexyl-2-benzothiazyl sulfinamide), 165 ° C., 60
A test piece for JIS K-6301-8 item 90 ° peel test was prepared under the conditions of Kg / cm ² and 15 minutes.

Metal: Mild steel plate SPCC (25 × 60 × 1.6 mm) degreased with a solvent and treated with Shouttoplast Adhesion method: Brushing the above adhesive to a thickness of about 2 to 3 μm Example 2 In Example 1, the epoxy was used. Instead of the resin mixed solvent solution, a solution of poly-2-chlorobutadiene (viscosity 10 ⁴ poise) of the same solid content concentration in methyl ethyl ketone was used.

Example 3 In Example 2, instead of poly-2-chlorobutadiene, polyethyl acrylate (viscosity 10 ⁴ poise) was used.

Example 4 In Example 2, instead of the methyl ethyl ketone solution of poly-2-chlorobutadiene, a carbon black (particle size
10 μm) 10% methyl ethyl ketone 10% dispersion was used.

Comparative Example In Example 2, poly-2-chlorobutadiene was not used and only methyl ethyl ketone was used.

The peel strengths of the adhesives adhered in the above Examples and Comparative Examples were measured according to JIS K-6301, 90 ° peel test method. The results obtained are shown in the following table. In addition, the observation result of the peeling start point is also shown in this table.

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Claims (1)

[Claims] 1. A novolak type phenol resin and hexamethylenetetramine as a curing agent for the same, (a) a polymer substance having a softening temperature of about 100 to 200 ° C., and (b) a viscosity (25).
A vulcanizing adhesive of NBR and a metal, which is obtained by adding at least one of a polymer substance having a temperature of about 10 ³ poise or more and (c) a granular inorganic substance having a particle size of about 1 to 100 μm.