JPS62263271A - Adhesive composition - Google Patents

Abstract

PURPOSE:An adhesive composition suitable for bonding between metal and hydrogenated NBR, obtained by dissolving a hydrogenated NBR blend and a novolak phenolic resin blend in a ketone or aromatic hydrocarbon solvent. CONSTITUTION:(A) A hydrogenated NBR blend blended with a crosslinking agent and other compounding agents and (B) a novolak phenolic resin blend mixed with a curing agent are dissolved in (C) a solvent consisting of a ketone, aromatic hydrocarbon or a mixture thereof to give an adhesive composition. The blending ratio is preferably 50-150pts.wt. novolak phenolic resin based on 100pts.wt. hydrogenated NBR and the concentration of the blend of the components A and B in the solvent C is preferably 5-15wt%.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to adhesive compositions. More specifically, the present invention relates to an adhesive composition used for bonding metal and hydrogenated NBR.

[Conventional technology]

Hydrogenated NBR generally has an acrylonitrile content of 30 to
It is obtained by hydrogenating the double bond of butadiene in acrylonitrile-butadiene copolymer rubber of 50% by weight, and exhibits chemical stability at a hydrogenation rate of about 80% or more, especially in terms of heat resistance and chemical resistance. It also has the property of having high rubber strength.

Regarding heat resistance, the higher the hydrogenation rate, the better the heat resistance, and therefore it is preferable to use one with a hydrogenation rate of 100%, but from the viewpoint of the required degree of heat resistance, cost, etc. Hydrogenated NBR with a low hydrogenation rate (hydrogenation rate of about 90 to 100%) is also often used practically.

Taking advantage of these favorable properties of hydrogenated NBR.

By adhering this to metal, it can be used for various oil seals, packings, valves, gasket materials, etc., but conventionally it has been used for hydrogenated NBR, especially for hydrogenated NBR compounds with high peroxide content. No suitable adhesive existed.

For example, in conventional adhesives made of phenolic resin alone, air enters during molding of hydrogenated NOH, and this causes a decrease in adhesive strength.

In addition, chlorinated rubber adhesives have low heat resistance, which means that the preferable heat resistance of hydrogenated NBR cannot be effectively exhibited.

[Problem that the invention seeks to solve]

The present inventors conducted various studies in search of an adhesive that would ensure sufficient adhesion without substantially reducing the preferable heat resistance of hydrogenated NBR when adhering hydrogenated NBR to metal. As a result, it has now been discovered that an adhesive composition in which hydrogenated NBR is mixed with a novolac type phenolic resin and the two are co-crosslinked satisfies these requirements.

[Means for solving problems]

Therefore, the present invention relates to an adhesive composition for adhering metal and hydrogenated NBR, and the adhesive composition comprises a hydrogenated NBR metal alloy containing a crosslinking agent and other compounding agents, and a novolac type phenol containing a curing agent. The resin composition is dissolved in a solvent consisting of a ketone, an aromatic hydrocarbon, or a mixture thereof.

As the hydrogenated NBR, those mentioned above are used. A crosslinking agent and other additives are included in this formulation. Crosslinking agents are generally organic peroxides, such as dicumyl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane.

2,5-dimethyl-2,5-di(tert-butylperoxy)hexyne-3,1,3-bis(tert-butylperoxyisopropyl)benzene etc. are hydrogenated NBR100
It is used in a proportion of about 0.1-15 parts by weight per part by weight.

As other compounding agents, various commonly used compounding agents are used, but fillers such as carbon black, white carbon, talc, clay, wollastonite, and celite are preferably compounded, and in addition, zinc white, plastic Agents, anti-aging agents, crosslinking accelerators, etc. are also blended as appropriate.

Further, the novolac type phenol resin used in combination with hydrogenated NBR is represented by the following general formula.

In this way, novolak-type phenolic resin is obtained as a pine resin-like substance that is soluble in organic solvents such as alcohols and ketones by reacting phenol or alkyl-substituted phenol with formaldehyde under an acid catalyst.
By adding a curing agent such as an amine compound or a phosphorus compound to this and heating it, an insoluble and infusible phenol resin is formed. In the present invention, a fast-curing resin is preferably used, has a high ortho bond, and has a free phenol content of 3%.
Those having a melting point of about 90 to 120°C are generally used.

An amine compound or a phosphorus compound is generally used as a curing agent for novolac type phenolic resin.

As the amine compound, those represented by the following general formula are used.

(a) HIN(CJl,,NH)mc%H,%NH
.

m: o or a positive integer up to about 25 n: positive integer (b) 112N-R, -NH.

(C) Heterocyclic amine compound Hexamethylenetetramine etc. (d) Ammonium salt Tetrabutylammonium bromide, Tetrabutylammonium bromide.

Tetrapropylammonium chloride, etc. Also, as the phosphorus compound, for example, phosphines such as triphenylphosphine, phosphonium salts such as benzyltriphenylphosphonium chloride, etc. are used.

Among these curing agents, hexamethylenetetramine is preferably used, and its blending ratio is approximately 10 to 15 parts by weight per 100 parts by weight of the novolac type phenolic resin.

Novolak type phenolic resin is hydrogenated NBR10
Used in a ratio of about 10 to 200 parts by weight per 0 parts by weight,
Approximately 50 to 15 in terms of workability, fluidity, adhesion, etc.
It is used in a proportion of 0 parts by weight.

Hydrogenated NBR and novolak-type epoxy resin are mixed together with other compounding agents on a roll or the like, and then mixed in a solvent consisting of ketone, aromatic hydrocarbon, or a mixture thereof, in an amount of about 5 to 15% by weight as a compound. An adhesive composition is formed by dissolving the adhesive at a concentration of . Methyl ethyl ketone and the like are used as the ketone, and toluene, benzene and the like are used as the aromatic hydrocarbons, but from the viewpoint of sprayability, they are preferably used as a mixture in which both account for about 30 to 70% by weight.

When adhering using the adhesive solution prepared in this way, the metal is first coated with a phenolic resin solution as a primer. The metal used is mild steel, stainless steel, aluminum, aluminum die-cast, brass, zinc, etc., and a phenolic resin, which was conventionally used for adhesion with hydrogenated NBR, is applied with a primer solution. .

The adhesive solution is then applied, and after solvent drying for about 5-30 minutes, it is brought into contact simultaneously with hydrogenated NBR, also commonly used in the form of a formulation, using a vulcanization mold, at a temperature of about 140-180 °C. By heating under pressure for about 3 to 30 minutes, the metal and the hydrogenated NBR are vulcanized and bonded.

(Effect of the invention) The adhesive composition according to the present invention has a metal, hydrogenated NBR,
It can be applied to bonding acrylic rubber, fluororubber, etc., but since its main component is hydrogenated NBR, it is generally used for bonding hydrogenated NBR and metals in consideration of heat resistance.

In the case of hydrogenated NBH, a peroxide crosslinking method is usually used, and this reduces adhesion strength due to air intrusion, which is often seen when hydrogenated NBR compounds with a high organic peroxide content are vulcanized. This phenomenon is no longer observed because hydrogenated NBR is used for both the adhesive composition and the adherend, and these and the novolac type phenol resin co-crosslink and adhere to each other.

Moreover, while sufficient adhesion is ensured between the metal and the hydrogenated NBR, the preferable heat resistance of the hydrogenated NBR is not substantially impaired, so it is suitable for various uses such as those mentioned above. It can be used effectively.

〔Example〕

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

Example hydrogenation ■R (Nippon Zeon product Zetpol 1020)
100 parts SRF carbon black
40 zinc white
10 stearic acid
1 Anti-aging agent [poly(2,2,4-trimethylene-1,
2-dihydroquinoline)] 1. Crosslinking agent (dicumyl peroxide) 8. Curing agent (hexamethylenetetramine) 1.5 Novolak type phenolic resin 75 or more of the above ingredients were kneaded using an open roll.

10 parts by weight of the obtained blend and 90 parts by weight of an equal weight mixture of methyl ethyl ketone and toluene were stirred using an agitator stirrer to prepare an adhesive composition.

A phenolic resin primer (Anchor Chemical Co. product Typly BN) was applied to a mild steel plate whose surface had been roughened by degreasing with a solvent and shot blasting.
After drying at 0° C. for 10 minutes, the above adhesive composition was applied on top of this primer layer and left at room temperature for 1 hour to evaporate the solvent.

Next, using a bonded rubber compound in which no novolac type phenol resin and its curing agent were mixed in the above compound, and the amount of crosslinking agent was reduced by half, JIS K-63018, 3 was used.
According to the 90° peel test method (autograph, speed 200 m/min), the vulcanization adhesion to the adhesive-coated mild steel plate was
The test was carried out under the conditions of 80° C., 60 kg/ffl, and 4 minutes.

Example 2 In Example 1, in preparing the adhesive composition.

The amount of novolac type phenol resin blended was changed to 125 parts by weight.

Comparative Example 1 In Example 1, instead of the adhesive composition, a commercially available phenolic adhesive was applied and baked at 100° C. for 30 minutes.

Comparative Example 2 In Example 1, a commercially available chlorinated rubber adhesive was used instead of the adhesive composition.

The results of the peel test for the adhesives obtained in each of the above Examples and Comparative Examples are shown in Table 1 below.

Table 1 Example 1 - 赳朕KA story cb1 Monthly publication Example 1
6.5 100 Example 2 6.7
100 Comparative Example 1 3.2
70 Comparative Example 2 6.3 1
00 Regarding the electrocutes of Example 1 and Comparative Example 2, 1
Heat treatment was performed in an atmosphere at 50° C. for a predetermined period of time, and a similar peel test was conducted on the heat treated product. The results obtained are shown in Table 2 below.

Table 2

Claims (1)

[Claims] 1. A hydrogenated NBR compound containing a crosslinking agent and other compounding agents and a novolak type phenolic resin compound containing a curing agent are dissolved in a solvent consisting of a ketone, an aromatic hydrocarbon, or a mixture thereof. Dissolved metal and hydrogenated NB
Adhesive composition for bonding with R. 2. The adhesive composition according to claim 1, wherein about 10 to 200 parts by weight of a novolac type phenolic resin is used in the form of a blend per 100 parts by weight of hydrogenated NBR.