JP2000001658A - Vulcanized adhesive composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition capable of adhering in a wide range of curing temperatures in a short time, exhibiting an excellent thermal aging resistance, and useful for adhering metals to rubbers, etc., by using the organic solvent solution of a novolak type phenolic resin, a resol type phenolic resin and a specific epoxy resin. SOLUTION: This vulcanized adhesive composition comprises an organic solvent solution obtained by dissolving (A) a novolak type phenolic resin as an adhesive component, (B) a resol type phenolic resin as a curing agent, and (C) a bisphenol A type epoxy resin (for example, the epoxy resin which is liquid at 25 deg.C and has an epoxy equivalent of 180-2,700 or the epoxy resin which is solid and has a softening point of <=150 deg.C and an epoxy equivalent of 180-2,700) in (D) an organic solvent such as a ketone or an alcohol in a solid content concentration of, for example, 5-20 wt.%. The composition preferably comprises 100 pts.wt. of the component A and 10-100 pts.wt. of the component B.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a vulcanized adhesive composition. More specifically, the present invention relates to a vulcanized adhesive composition which is effectively used for vulcanized adhesion between a metal and NBR or acrylic rubber.

[0002]

2. Description of the Related Art For vulcanization adhesion between metal and NBR or acrylic rubber, a novolak-type phenol resin derived from phenol or p-substituted phenol is used as a main component, and hexamethylenetetramine is added as a curing agent. Sulfuric adhesive compositions and the like are used. However, such a vulcanized adhesive composition has the following disadvantages.

(1) The gas of hexamethylenetetramine is generated and contaminates the inside of the baking furnace. (2) The cured film is colored. (3) The expiration date is short. Therefore, the present inventors have previously used a vulcanized adhesive composition containing a novolak-type phenol resin as an adhesive component, which is used for vulcanization bonding between metal and NBR or acrylic rubber, Assuming that hexamethylenetetramine is not used as a curing agent, a novolak-type phenol resin obtained from a mixture of m-cresol and p-cresol was used as an adhesive component, and vulcanization was performed by adding a resole-type phenol resin as a curing agent. An adhesive composition has been proposed (JP-A-10-12
No. 1020).

[0004] The vulcanized adhesive composition proposed here is about
Adhesion over a wide range of baking temperatures from 100 to 200 ° C is possible,
Moreover, although the baking at that time has the effect that a short time of about 3 to 5 minutes is sufficient, in terms of heat aging resistance when left in a high temperature atmosphere of about 100 ° C. or more for a long time, It turns out that it is not enough.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a vulcanized adhesive composition comprising a novolak-type phenol resin as an adhesive component and a resol-type phenol resin as a curing agent. An object of the present invention is to provide an improved aging property.

[0006]

SUMMARY OF THE INVENTION The object of the present invention is as follows.
This is achieved by a vulcanized adhesive composition comprising an organic solvent solution of a novolak type phenol resin, a resol type phenol resin and a bisphenol A type epoxy resin.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The novolak type phenol resin used as an adhesive component of the vulcanized adhesive composition according to the present invention is a novolak type phenol resin obtained from a mixture of m-cresol and p-cresol as described above. Not limited to, general phenols and formaldehyde about 0.1
It is obtained by reacting in the presence of an acidic catalyst such as hydrochloric acid and oxalic acid at a molar ratio of ~ 1.0, and examples of phenols include phenol, m-cresol,
p-cresol, a mixture of m-cresol and p-cresol, p-tert-butylphenol, p-phenylphenol,
Any one can be used as long as it has two or three substitutable nuclear hydrogen atoms at the o- and / or p-position to the phenolic hydroxyl group such as bisphenol A.

A resol type phenol resin used as a curing agent for such a novolak type phenol resin is characterized in that phenols and formaldehyde are used as a basic catalyst.
(Alkali metal, hydroxide of magnesium, etc.) can be obtained by reaction in the presence, as phenols at that time, for example, phenol, m-cresol, p-cresol, m-cresol and p-cresol Mixture of p-
O- and / or phenolic hydroxyl groups such as tertiary butylphenol, p-phenylphenol, bisphenol A, etc.
Alternatively, any compound having two or three substitutable nuclear hydrogen atoms at the p-position can be used.

The novolak type phenolic resin and the resol type phenolic resin as a curing agent thereof are the same as the former 100%.
The latter is used in a proportion of about 10 to 100 parts by weight, preferably about 20 to 40 parts by weight, based on parts by weight. When the proportion of the resol-type phenolic resin is less than this, the novolak-type phenolic resin is not sufficiently cured, while when used at a higher proportion, the compatibility with the rubber deteriorates.

In order to improve the heat aging resistance of the vulcanized adhesive composition of the present invention, a bisphenol A type epoxy resin is further added and used. Bisphenol
As an A-type epoxy resin, the epoxy equivalent is about 180-2700
A liquid or a softening point of about 15 at room temperature (25 ° C.).
Solids at 0 ° C. or lower are used in an amount of about 1 to 10 parts by weight in the case of a liquid resin and about 10 to 30 parts by weight in the case of a solid resin per 100 parts by weight of the total amount of the phenol resin. The higher the proportion of the bisphenol A type epoxy resin used, the higher the heat resistance, but when antifreeze resistance or the like is required, its properties tend to be reduced.

When a bisphenol A type epoxy resin is used, the reaction between the bisphenol A type epoxy resin and the phenol resin proceeds by heating to about 100 ° C. or higher even in the absence of a catalyst. Methylimidazole, 2-ethyl-4-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-phenylimidazole, 1-benzylimidazole, 1-benzyl-2-methylimidazole, 2,4-diamino-6 -[2-Methylimidazoline
-(1)]-Ethyl imidazole compound such as s-triazine is used as a curing catalyst at a ratio of about 4% by weight or less based on the bisphenol A type epoxy resin. Stability is reduced.

These phenolic resins and bisphenol A type epoxy resins are used in an organic solvent in which ketones such as acetone and methyl ethyl ketone, and alcohols such as methanol and ethanol are used in an amount of about 5 to 20% by weight.
Is prepared and used as an organic solvent solution in which the solid component concentration is dissolved.

[0013] Vulcanization bonding using a vulcanizing adhesive composition comprising such an organic solvent solution is performed by applying the composition on a metal such as mild steel, stainless steel, aluminum or aluminum die-cast, and air-drying at room temperature. About 100 ~ 2
Dry at 00 ° C. for about 5 to 10 minutes, bond an unvulcanized NBR compound or an acrylic rubber compound,
It is carried out by pressure vulcanization at 180 to 200 ° C.

As the unvulcanized NBR compound or acrylic rubber compound, for example, the following are used. (Formulation Example I) 100 parts by weight of active chlorine-containing acrylic rubber HAF carbon black 70 粉末 powdered silica 5 〃 microcrystalline wax 2 〃 (Ouchi Shinko Chemical Sannok) stearic acid 1 〃 4,4'-bis (2,2 '-Dimethylbenzyl) diphenylamine 2 0.3 Sulfur 0.3 ナ ト リ ウ ム Sodium stearate 3.5 〃 (Formulation Example II) 100 parts by weight of NBR (Nipol DN206, a product of Nippon Zeon Co., Ltd., middle and high nitrile) FEF carbon black 40 シ リ カ Silica powder 20 亜 鉛 Zinc oxide 5 〃 Stearic acid 1 ジ オ Dioctyl phthalate 5 〃 2,2,4-trimethyl-1,2-dihydroquinoline 1 ト リ Triallyl isocyanurate (70%) 0.8 〃 (Formulation Example III) NBR (Nipol 1001 from Nippon Zeon; high nitrile) 100 weight Part FEF carbon black 40 シ リ カ silica powder 20 亜 鉛 zinc oxide 5 ス テ stearic acid 1 〃 antioxidant (Sumitomo Chemical Antigen AS) 1 〃 C 0.8 加 Vulcanization accelerator (tetramethylthiuram disulfide) 2.5 〃 Vulcanization accelerator 2 〃 (N-cyclohexyl-2-benzothiazylsulfenamide) (Formulation Example IV) 100 parts by weight of epoxy group-containing acrylic rubber HAF carbon Black 10 粉末 Powdered silica 15 〃 Microcrystalline wax (Sannok) 2 〃 Stearic acid 1 防止 Antioxidant (Ouchi Shinko Chemical Nocrack White) 2 亜 鉛 Zinc dithiocarbamate 3 〃

[0015]

The vulcanized adhesive composition according to the present invention has a viscosity of about 10%.
Bonding is possible in a wide range of baking temperatures from 0 to 200 ° C, and the baking at that time is sufficiently short in about 3 to 5 minutes, while sufficiently maintaining the property, for example, about 100 ° C or more. Even when left for a long time in such a high-temperature atmosphere, there is almost no loss of adhesiveness.

[0016]

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

Example 1 100 parts by weight of novolak type phenol resin (Gunei Chemical product resin top PSF-2803) Resol type phenol resin 42 〃 (Company product resin top PL-2208, solid content 63%) Bisphenol A type epoxy resin 7 〃 ( Asahi Ciba Araldite AER260) Methyl ethyl ketone 1520 〃

Example 2 100 parts by weight of novolak type phenolic resin (Gunei Chemical product resin top PSF-2803) Resol type phenolic resin 53 〃 (Company product resin top PL-2208, solid content 63%) Solid bisphenol A type epoxy resin 33 〃 (Alardite AER6094 from Asahi Ciba) Methyl ethyl ketone 1894 〃

Example 3 100 parts by weight of novolak-type phenolic resin (Denippon Ink and Chemicals product phenolite KA-1053L, solid content 40%) Resole-type phenolic resin 20 20 (Fenolite 5900, solid content 60%) Solid bisphenol A type epoxy resin 9 〃 (Alardite AER6094 from Asahi Ciba) Methyl ethyl ketone 634 〃

The vulcanized adhesive compositions of Examples 1 to 3 comprising the above components were applied on mild steel sheets treated with zinc phosphate, allowed to stand at room temperature for 10 minutes and air-dried. ° C
A baking treatment was performed at a baking temperature of 10 minutes.

The unvulcanized rubber compound of Formulation Example I or II is bonded to these vulcanized adhesive-baked mild steel sheets,
Acrylic rubber was vulcanized at 180 ° C. for 4 minutes, and NBR was vulcanized at 200 ° C. for 3 minutes. About the obtained adhesive | bonded material, the adhesive strength and the rubber remaining area ratio were measured by the 90 degree peeling test. Such high temperature storage time
150 ° C for acrylic rubber with 0 hour data
In addition, NBR was left in a gear oven at 100 ° C., and the same measurement was performed for each leaving time.

Comparative Example 1 Commercially available hexamethylenetetramine-cured phenolic vulcanizing adhesive (Morton International product) Sixxon 715A (phenolic resin) 97 parts by weight Sixxon 715B (curing agent + pigment) 3 {methyl ethyl ketone 470}

Comparative Example 2 70 parts by weight of novolak type phenolic resin (Gunei Chemical product resin top PSF-2803) Resol type phenolic resin 48〃 (our company's product top PL-2208, solid content 63%) Methyl ethyl ketone 918〃

Using the vulcanized adhesive compositions of Comparative Examples 1 and 2, application on a mild steel plate, baking and measurement thereof were carried out in the same manner as in Examples 1 to 3.

The measurement results in the above Examples and Comparative Examples are shown in the following table. Table Vulcanization High-temperature storage formulation I Formulation II Adhesive time (hrs) Peeling force (KN / m) Remaining area ratio (%) Peeling force (KN / m) Remaining area ratio (%) Example 1 0 4.4 100 8.5 100 70 5.8 100 8.7 100 140 6.0 100 8.8 100 280 6.0 100 8.8 100 500 6.0 90 8.8 100 Example 2 0 4.4 100 8.5 100 70 5.8 100 8.6 100 140 6.1 100 8.8 100 280 6.0 100 8.8 100 500 6.0 100 8.8 100 Example 3 0 4.5 100 8.5 100 70 6.0 100 8.7 100 140 6.0 100 8.8 100 280 6.1 90 8.8 100 500 5.9 80 8.8 100 Comparative Example 1 0 4.4 100 8.5 100 70 5.5 60 8.7 100 140 4.0 20 7.6 90 280 2.2 0 5.9 60 500 2.0 0 8.8 20 Comparative Example 2 0 4.4 100 8.5 100 70 5.9 100 8.7 100 140 5.8 90 8.8 100 280 4.5 40 7.2 80 500 2.8 10 5.8 50

Claims (2)

[Claims] 1. A vulcanized adhesive composition comprising an organic solvent solution of a novolak type phenol resin, a resol type phenol resin and a bisphenol A type epoxy resin. 2. A vulcanized adhesive composition used for vulcanizing adhesion between a metal and NBR or acrylic rubber.