JP3428237B2 - 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 particularly, to vulcanization adhesive aqueous used in the prime <br/> suitable for vulcanization bonding between the metal and fluorine rubber.

[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 peroxide-crosslinked fluororubber. Further, in the adhesively bonded product, a phenomenon of deterioration in adhesiveness with time is observed under a high temperature condition in which a seal member such as an oil seal or packing is used.

[0004]

An object of the present invention is to provide an aqueous adhesive composition containing an amino group-containing silane compound, which has good adhesiveness of fluororubber to a metal and can be adhered even under high temperature conditions. An object of the present invention is to provide a water-based adhesive composition that does not deteriorate its properties.

[0005]

The object of the present invention is as follows.
Achieved by an aqueous vulcanizing adhesive containing [gamma] -methacryloxypropyltrialkoxysilane, amino group-containing trihydroxysilane and lower saturated carboxylic acid or inorganic acid.

As the γ-methacryloxypropyltrialkoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane and the like are preferably used.

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.

As the lower saturated carboxylic acid, formic acid, acetic acid, propionic acid and the like are used, and as the inorganic acid, hydrochloric acid, nitric acid, phosphoric acid and the like are used.

Each of the above components contains 100 to 900 parts by weight, preferably about 300 to 500 parts by weight, of amino group-containing trihydroxysilane per 100 parts by weight of γ-methacryloxypropyltrialkoxysilane, and a lower saturated carboxylic acid. The acid or inorganic acid is used in a proportion of about 30 to 400 parts by weight, preferably about 100 to 200 parts by weight, respectively. Lower saturated carboxylic acid or inorganic acid, it is desirable to adjust the pH of the aqueous vulcanizing adhesive to 4 to 7 from the viewpoint of improving the adhesiveness and stability, but there is also a balance with the amount of amino group-containing trihydroxysilane. Generally, it is used in a ratio within 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. (Formulation 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 product # 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]

The γ-amino group-containing trialkoxysilane-based water-based vulcanizing adhesive that has been conventionally used has good adhesiveness with the polyol-vulcanized fluororubber, but is a peroxide-vulcanized fluororubber. Is poor in adhesiveness, and when applied to a vulcanized molded product used under high temperature conditions, a decrease in adhesiveness with time cannot be avoided, but using the aqueous vulcanized adhesive of the present invention This makes it possible to obtain a fluororubber-metal bonding material that does not deteriorate in adhesiveness over time even under high temperature use conditions, regardless of whether it is polyol vulcanization or peroxide vulcanization. Further, when the pH of this aqueous vulcanized adhesive is adjusted to a range of 4 to 7 with a lower saturated carboxylic acid or an inorganic 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] From Examples 1 to 3 each of the following components (parts by weight), an aqueous vulcanizable adhesive was prepared, ingredients actual -1 actual -2 actual -3 .gamma.-methacryloxypropyl triethoxysilane 0.2 0.3 0.2 .gamma. Aminopropyltrihydroxysilane 40% aqueous solution 2.0 1.8 2.0 Acetic acid 0.3 0.3 Phosphoric acid 0.4 Ion-exchanged water 97.5 97.6 97.4 pH 5.0 4.8 4.5 The prepared water-based vulcanizing adhesive was applied on a zinc phosphate-coated mild steel sheet, It was 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 (rubber residual ratio). Also, after the bonded product was left in an oven at 200 ° C. for each time, the peeling force and the residual rubber area ratio were 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 0.8 γ-aminopropyltrihydroxysilane 2.5 ( 40% aqueous solution ) γ-methacryloxypropyltriethoxysilane 1.0 1.0 0.2 Methacrylic acid 0.4 Acetic acid 0.1 3.4 0.3 Ion-exchanged water 98.6 99.0 98.9 94.1 98.7 pH 5.8 4.5 3.7 5.0 5.0 From the application of the sulfur adhesive on the mild steel plate to the measurement of the peeling force and the rubber residual area ratio, the same procedure as in Examples 1 to 3 was performed.

The measurement results of each of the above Examples and Comparative Examples are shown in Tables 1 and 2 below.

[0019]                                 Table 1           Standing time Formulation example I  Formulation II  An example   (hrs)   Peel force (N / mm) Rubber residual rate (%)  Peel force (N / mm) Rubber residual rate (%) Example 1 0 5.4 100 6.0 100              70 5.4 〃 6.0 〃             140 5.3 〃 6.0 〃             240 5.3 〃 5.9 〃             500 5.3 〃 5.9 〃 Example 2 0 5.3 〃 6.0 〃              70 5.3 〃 5.9 〃             140 5.3 〃 5.9 〃             240 5.2 〃 5.9 〃             500 5.1 〃 5.9 〃 Example 3 0 5.4 〃 5.9 〃              70 5.4 〃 5.9 〃             140 5.4 〃 5.8 〃             240 5.4 〃 5.8 〃             500 5.4 〃 5.8 〃

Table 2 Leaving time Formulation example I Formulation example II Example (hrs) Peeling force (N / mm) Rubber residual rate (%) Peeling force (N / mm) Rubber residual rate (%) Comparative example 1 0 5.3 100 5.1 30 70 5.0 100 1.6 0 140 4.4 70 240 4.0 60 500 3.0 30 Comparative example 2 0 1.2 0 4.0 10 70 1.1 0 Comparative example 3 0 1.8 0 5.4 40 70 2.0 20 140 1.5 0 Comparative example 4 0 5.2 100 4.1 20 70 5.0 90 1.3 0 140 4.7 90 240 4.6 80 500 4.4 70 Comparative example 5 0 2.4 20 5.8 100 70 1.2 0 5.8 100 140 5.4 80 240 5.3 70 500 5.2 70

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) C09J 183/06 C09J 183/07 C09J 183/08

Claims (2)

(57) [Claims] 1. A metal comprising γ-methacryloxypropyltrialkoxysilane, an amino group-containing trihydroxysilane and a lower saturated carboxylic acid or an inorganic acid.
A water-based vulcanizing adhesive used for vulcanizing and adhering to and fluororubber . 2. Using the water-based vulcanizing adhesive according to claim 1.
Vulcanized and bonded fluororubber-metal bonding material.