JP2619599B2 - One-part self-crosslinking chloroprene adhesive - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a one-part self-crosslinking chloroprene adhesive, more specifically, a chloroprene rubber as a base component, to which chlorinated polypropylene is added, and to which aminoalkylalkoxysilane is condensed to form a self-crosslinking adhesive. Accordingly, the present invention relates to a one-pack chloroprene-based adhesive capable of exhibiting excellent adhesive strength and heat resistance, in particular, strength under high temperature load and heat creep resistance, even to a polypropylene adhered material.

[0002]

2. Description of the Related Art Among various rubber-based adhesives, chloroprene-based adhesives based on chloroprene rubber have been applied to a wide range of applications. As such an adhesive, chloroprene rubber and a tackifier resin, a one-pack type obtained by dissolving a vulcanizing agent or a vulcanization accelerator as necessary, in a suitable organic solvent, are known, but heat resistance, especially The strength at high temperature (80 to 130 ° C.) load and the heat creep resistance are weak. Therefore, a two-pack type combining an isocyanate-based curing agent is being adopted. The present inventors have conducted intensive studies to provide a one-pack type chloroprene-based adhesive exhibiting excellent adhesive strength and heat resistance equivalent to or better than the two-pack type, and as a result, condensed aminoalkylalkoxysilane A one-pack type chloroprene-based adhesive comprising a chloroprene rubber and a petroleum resin-based and an organic solvent as a tackifying resin has been developed, and a patent application is pending (see JP-A-1-301776).

[0003] In this adhesive, chloroprene rubber is reactively modified with an aminoalkylalkoxysilane during its compounding and preparation, and the aminoalkylalkoxysilane causes a cross-linking reaction by moisture. However, when applied to a polypropylene coating material with poor polarity, it was recognized that the initial adhesive strength, normal adhesive strength, and heat aging resistance were inferior to those of other coating materials. . On the other hand, chlorinated propylene has been conventionally known as a material having excellent adhesiveness to polypropylene, but has poor compatibility with other materials, and it has been impossible to stably compound it as an adhesive. For the purpose of solving this problem, chlorinated polyolefins having improved compatibility by copolymerizing different monomers have been developed, but at the expense of adhesive strength.

[0004]

Means for Solving the Problems Accordingly, the present inventors have:
In the above-mentioned adhesive compounding, it has been found that when chloroprene rubber and chlorinated polypropylene are reactively modified with aminoalkylalkoxy, compatibility is improved, and it is possible to develop an adhesive which is stable and has good adhesiveness to polyolefins. It was completed.

That is, the present invention relates to a one-pack type chloroprene adhesive comprising a chloroprene rubber condensed with an aminoalkylalkoxysilane, a chlorinated polypropylene condensed with an aminoalkylalkoxysilane, a petroleum resin and an organic solvent as a tackifying resin. A chlorinated polypropylene obtained by condensing aminoalkylalkoxysilane with 100 parts of chloroprene rubber (parts by weight, hereinafter the same) of chloroprene rubber obtained by condensing aminoalkylalkoxysilane.
The present invention provides a one-part self-crosslinking chloroprene-based adhesive characterized by using a part.

The present invention is characterized in that chlorinated polypropylene is added to chloroprene rubber as described above, and the proportion is 2 to 100 parts, preferably 5 to 100 parts, of chlorinated polypropylene per 100 parts of chloroprene rubber. 50
Department. If the amount of the chlorinated polypropylene is less than 2 parts, the desired polyolefin adhesiveness cannot be obtained, and if it exceeds 100 parts, the initial adhesiveness and heat resistance decrease.

The aminoalkylalkoxysilane (hereinafter abbreviated as aminosilane) in the present invention includes, for example, aminomethyltriethoxysilane, N- (β-aminoethyl) aminomethyltrimethoxysilane, aminomethyldiethoxysilane, N- ( (β-aminoethyl) methyltributoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropylmethyldiethoxysilane, γ-
Aminoisobutyltrimethoxysilane, N- (β-aminoethyl) -γ-aminopropyltrimethoxysilane,
N- (β-aminoethyl) -γ-aminopropylmethyldimethoxysilane, N- (β-aminoethyl) -γ-amino-β-methylpropyltrimethoxysilane and the like can be mentioned. Usually, the amount of the aminosilane used may be selected in the range of 2 to 20 parts with respect to 100 parts of the total amount of the chloroprene rubber and the chlorinated polypropylene.

The petroleum resin used as the tackifier resin in the present invention includes, for example, aromatic hydrocarbons, aliphatic hydrocarbons and alicyclic hydrocarbons. The amount of the tackifying resin used is usually 10 to 10 with respect to 100 parts of chloroprene rubber.
What is necessary is just to select in the range of 0 parts.

Examples of the organic solvent in the present invention include aromatic solvents such as toluene and xylene, acetone, ME
Examples include ketones such as K and MIBK, alicyclics such as cyclohexane, aliphatics such as hexane and pentane, esters such as ethyl acetate and butyl acetate, and chlorinated hydrocarbons such as trichloroethylene.

The one-part self-crosslinking chloroprene adhesive according to the present invention is obtained by dissolving the above-mentioned chloroprene rubber and chlorinated polypropylene in an organic solvent, adding aminosilane to each, and condensing under predetermined conditions. Thereafter, both condensation products are mixed, and the mixture is mixed with a petroleum resin-based tackifying resin to produce the product. Note that chloroprene rubber and chlorinated polypropylene may be dissolved in an organic solvent and aminosilane may be condensed at once. Also,
If necessary, a suitable amount of a filler, a dehydrating agent, a plasticizer, an antioxidant, or the like may be blended with such an adhesive as a stabilizer during rubber kneading, such as magnesium or zinc white. If methanol or the like is added, storage stability is improved.
The adhesive may be prepared by dissolving according to a usual roll kneading method or a direct dissolving method, and then reacting and condensing aminosilane under predetermined conditions.

[0011]

The adhesive of the present invention having the above constitution exhibits excellent initial adhesive strength, normal adhesive strength and heat resistant adhesive strength even when applied to a polypropylene adhered material (sheet, film, foam). can do. As described above, when the present invention is applied to a polypropylene-coated material, its usefulness is remarkably exhibited, but other coating materials, for example, other polyolefin-coated materials (polyethylene, polypropylene and diene monomer and Of glass fiber, wood flour, waste paper, etc., metal, woven fabric, fiber material, wood, leather, other plastic materials (sheet, film, foam) etc. It goes without saying that the present invention can be applied to lamination.

[0012]

Next, the present invention will be described more specifically with reference to examples and comparative examples. Examples 1 to 3 and Comparative Example 1 In each component having the number of parts shown in Table 1 below, first knead chloroprene rubber and magnesia with a mixing roll, dissolve in toluene, mix chlorinated polypropylene, add aminosilane, The reaction is carried out at 80 ° C. for 4 hours, then, after cooling, a petroleum resin is added and mixed with stirring to obtain a one-part adhesive.

Comparative Example 2 For each component having the number of parts shown in Table 1 below, chloroprene rubber and magnesia were first kneaded with a mixing roll, and then dissolved together with chlorinated polypropylene and petroleum resin in toluene to obtain a main ingredient. At the time of use, a two-pack type is prepared by adding triphenylmethane triisocyanate (manufactured by Sumitomo Bayer Urethane Co., Ltd., Desmodur R) as a curing agent to the main agent (main agent 100 / hardener 5).

Performance Tests The following items were tested for the one-pack or two-pack adhesives of Examples 1 to 3 and Comparative Examples 1 and 2, and the results are also shown in Table 1. (1) Storage stability After storage at 40 ° C. for 24 hours, the presence or absence of separation and gelation is visually evaluated. ○ indicates neither separation nor gelation, and × indicates both separation and gelation. (2) Adhesive polypropylene base material (Mitsui Petrochemical Industries, Ltd., IP-
461), each adhesive was applied by air spray at 150 g / cm ² , dried at 80 ° C. for 2 minutes, and then heated to 120 ° C. with polyolefin foam skin material (Toray Co., Ltd., Toray Peff) at 1.0 kg / cm ^2. A test piece is prepared by pressing at a pressure of cm ² for 30 seconds. Initial peel strength 10 minutes after laminating (pressing) (kg /
25 mm), the normal peel strength (kg / 25 mm) after curing for 24 hours at 20 ° C. and 65% RH, and the peel strength (kg / 25 mm) after heat aging (70 ° C. × 100 hours), respectively. Then, a load of 50 g / 25 mm is applied to one end of the skin material side in an atmosphere of 70 ° C., and the peel length (heat-resistant creep) after 24 hours is measured. In Table 1, AF indicates interface destruction from the polypropylene base material, MB indicates destruction of the skin material, and drop indicates peeling of 50 mm or more.

[0015]

[Table 1]

Note) Neoprene WHV manufactured by Showa Dupont Chemical Co., Ltd., γ-aminopropyltriethoxysilane, NUC Silicone A-1100 manufactured by Nippon Unicar Co., Ltd., Sanyo Kokusaku Pulp Co., Ltd.
0% toluene solution)) Toyo Kasei Kogyo Co., Ltd., Hard Len 15L (30% toluene solution)) Nippon Petrochemical Co., Ltd., Nisseki Neopolymer 120

Claims (1)

(57) [Claims] 1. A one-pack chloroprene adhesive comprising a chloroprene rubber condensed with an aminoalkylalkoxysilane, a chlorinated polypropylene condensed with an aminoalkylalkoxysilane, a petroleum resin as a tackifying resin and an organic solvent. And 2 to 100 parts by weight of chlorinated polypropylene obtained by condensing aminoalkylalkoxysilane with 100 parts by weight of chloroprene rubber obtained by condensing aminoalkylalkoxysilane. Liquid self-crosslinking chloroprene adhesive.