JP3513959B2 - Aqueous vulcanizing adhesive - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an aqueous vulcanizing adhesive. More specifically, it relates to a water-based vulcanizing adhesive that is preferably used for vulcanizing adhesion between a metal and fluororubber.

[0002]

2. Description of the Related Art Japanese Unexamined Patent Publication (Kokai) No. 5-86335 describes an aqueous adhesive composition containing an amino group-containing trialkoxysilane compound and an unsaturated carboxylic acid. It is said that it is preferably used for vulcanization adhesion to metals such as rubber, fluororubber and NBR.

However, this aqueous adhesive composition is
Not evenly applied on the metal surface, resulting in unevenness, and not only rusting after application, but this composition itself gels when left at room temperature for about 1 month, making it unusable It has drawbacks such as Further, regarding the most important adhesiveness, it is pointed out that the adhesiveness is not sufficient in the case of fluororubber.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide an aqueous adhesive composition containing an amino group-containing silane compound and an unsaturated carboxylic acid, which improves the adhesion of fluororubber to a metal. It is to provide things.

[0005]

The object of the present invention is as follows.
This is achieved by an aqueous vulcanizing adhesive containing (A) amino group-containing trihydroxysilane, (B) unsaturated carboxylic acid and (C) formic acid, acetic acid or propionic acid .

Examples of amino group-containing trihydroxysilanes include ω-aminoalkyltrihydroxysilane and N-β-
(Aminoethyl) -γ-aminopropyltrihydroxysilane, γ-ureidopropyltrihydroxysilane and the like are used, and γ-aminopropyltrihydroxysilane is preferably used.

The unsaturated carboxylic acids include methacrylic acid, acrylic acid, maleic acid, fumaric acid, itaconic acid,
Crotonic acid, vinylsulfonic acid, vinylphosphonic acid and the like are used, and methacrylic acid is preferably used.

[0008]

Each of the above components contains about 5 to 40 parts by weight of unsaturated carboxylic acid per 100 parts by weight of amino group-containing trihydroxysilane.
Parts by weight, preferably about 15 to 25 parts by weight, formic acid, vinegar
About 5 to 40 parts by weight of acid or propionic acid , preferably about 8
Used in a proportion of up to 15 parts by weight. If the proportion of unsaturated carboxylic acid is lower than this, the purpose of improving the adhesiveness cannot be achieved, while if it is used in a proportion higher than this, the acidic substance remains in the film and causes metal corrosion, and The stability of the composition itself also deteriorates. Formic acid, acetic acid
Or propionic acid , from the viewpoint of improving the adhesiveness, it is desirable to adjust the pH of the aqueous vulcanizing adhesive to 4 to 7, and there is a balance with the amount of unsaturated carboxylic acid, but it is generally used in the ratio in the above range. .

Each of these components is prepared as an aqueous composition such that the total amount of each of these components comprises about 0.5-5% by weight, preferably about 1-2% by weight. The preparation can be easily carried out by simply mixing the respective components in ion-exchanged water and stirring for a few minutes.

The vulcanization adhesion using the water-based vulcanizing adhesive thus prepared is preferably a metal plate which is surface-treated with the water-based vulcanizing adhesive, for example, a phosphate-coated mild steel plate or stainless steel. Steel plate, chromated stainless steel plate,
Apply by dipping or spraying on aluminum steel plate, aluminum sheet treated with Alodine, etc., and about 5-10 at about 100-150 ℃
After drying for about a minute, an unvulcanized fluororubber compound or the like is bonded thereto, and pressure vulcanization is performed under the vulcanizing conditions of the rubber used.

Examples of the unvulcanized fluororubber compound include the following compounding examples. (Compounding Example I) Fluorine rubber (DuPont product Viton E45) 100 parts by weight Calcium metasilicate 40 MT carbon black 2 Magnesium oxide (Kyowa Chemicals magnesia # 150) 6 Calcium hydroxide 3 Vulcanizing agent (DuPont product Curative # 30) 2 Vulcanization accelerator (Curative # 20) 1) (Compounding example II) Fluororubber (Daikin product Daier G901) 100 parts by weight Calcium metasilicate 20 MT Carbon black 20 Magnesium oxide (Kyowa Chemical product magnesia # 150) 6 Calcium hydroxide 3 Triallyl isocyanurate 1.8 Peroxide cross-linking agent (NOF Products Perhexa 25B) 0.8

[0013]

EFFECTS OF THE INVENTION In the conventionally used γ-amino group-containing trialkoxysilane-based water-based vulcanizing adhesive, by changing the γ-amino group-containing trialkoxysilane to a γ-amino group-containing trihydroxysilane, The vulcanization adhesion of rubber to metal can be greatly improved. In addition, the pH of this water-based vulcanizing adhesive is adjusted to formic acid, acetic acid or
When adjusted to a range of 4 to 7 with propionic acid , not only the adhesive property but also the storage stability can be improved.
Therefore, this water-based vulcanizing adhesive is preferably used when manufacturing oil seals, packings, gaskets, valves and the like.

[0014]

EXAMPLES The present invention will now be described with reference to examples.

[0015] Example 1 from the secondary of each ingredient (parts by weight), an aqueous vulcanizable adhesive was prepared, ingredients actual -1 actual -2 .gamma.-aminopropyl-trihydroxy silane 40% aqueous solution 2.5 1.5 methacrylic acid 0.2 0.1 Acetic acid 0.1 0.1 Ion-exchanged water 97.2 98.3 pH 5.0 5.2 The prepared water-based vulcanizing adhesive was applied on a zinc phosphate-coated mild steel sheet and dried at 120 ° C. for 5 minutes.

The vulcanized adhesive-coated mild steel sheet was bonded to the unvulcanized fluororubber compound of Formulation Example I or II described above, and pressure vulcanization was performed at 180 ° C. for 6 minutes. The area ratio was measured.

Comparative Examples 1 to 5 An aqueous vulcanizing adhesive was prepared from the following components (parts by weight), and the component ratio-1 ratio-2 ratio-3 ratio-4 ratio-5 γ-aminopropyltriethoxysilane. 1.0 1.0 γ-Aminopropyltrihydroxysilane 2.5 2.5 2.5 40% aqueous solution Methacrylic acid 0.4 0.2 0.4 Acetic acid 0.16 0.3 Ion-exchanged water 98.6 98.64 97.1 97.2 97.5 pH 5.8 5.0 5.0 5.0 10.7 On mild steel plate using this aqueous vulcanizing adhesive From the coating to the peeling force and the measurement of the rubber remaining area ratio were performed in the same manner as in Examples 1 and 2 .

The measurement results in each of the above Examples and Comparative Examples are shown in Table 1 below. Table 1 Compounding Example I Compounding Example II Example Peeling force (N / mm) Rubber remaining area ratio (%) Peeling force (N / mm) Rubber remaining area ratio (%) Example 1 5.4 100 6.0 100 〃 2 5.2 100 6.0 100 Comparative Example 1 5.2 80 5.1 30 〃 2 5.0 80 5.4 50 〃 3 5.2 90 5.8 80 〃 4 4.6 60 4.9 30 〃 5 3.3 20 4.0 20

Further, Examples 1 and 2 and Comparative Examples 1 and 2
After preparing the water-based vulcanizing adhesive prepared in
After leaving for 10 days, 20 days or 30 days, coating on a mild steel plate, drying and pressure vulcanization were performed, peeling force and rubber residual area ratio (rubber residual ratio) were measured, and stability was evaluated. .
The results obtained are shown in Table 2 below. Table 2 standing Formulation Example I Formulation Example II Example days peel strength (N / mm) Rubber Retention (%) Peeling strength (N / mm) Rubber Retention (%) Example 1 10 5.4 100 6.0 100 20 5.4 〃 6.0 〃 30 5.2 〃 5.8 〃 Example 2 10 5.2 〃 5.9 〃 20 5.1 〃 5.9 〃 30 5.1 〃 5.9 〃 Comparative Example 1 10 5.1 80 5.1 30 20 4.2 40 4.0 10 30 (Gelization) (Gelization) Comparative Example 2 10 5.0 80 5.3 50 20 4.6 60 3.3 20 30 3.1 20 2.0 10

Further, the rust preventive property of the coated surface under the conditions of 40 ° C. and 90% RH was evaluated by the rust generation area ratio (unit:%). The results obtained are shown in Table 3 below. Table 3 Leaving time 70hrs 140hrs 240hrs 500hrs Example 1 0 0 5 10 〃 2 0 0 0 5 Comparative Example 1 5 10 10 30 〃 2 5 10 10 20

─────────────────────────────────────────────────── --- Continuation of the front page (56) References JP-A-5-86335 (JP, A) JP-A-2-283780 (JP, A) JP-A-61-207477 (JP, A) JP-A-7- 34054 (JP, A) JP-B 37-2979 (JP, B1) (58) Fields investigated (Int.Cl. ⁷ , DB name) C09J 4/00-201/10

Claims (2)

(57) [Claims] 1. (A) Amino-group-containing trihydroxysilane, (B) unsaturated carboxylic acid and (C) formic acid, acetic acid or pr
A water-based vulcanizing adhesive containing ropionic acid . 2. The water-based vulcanizing adhesive according to claim 1, which is used for vulcanizing and adhering a metal and a fluororubber.