Loctite Corporation

Avery Products Corporation

Avery International Corporation

Martin Hauser

Bernard Miles Malofsky

Gustav A Schmidt

Maurice Douek

There is provided a curable anaerobic pressure sensitive adhesive composition, a mixture of a curable anaerobic system and a high molecular weight polymer system. The mixture which may include a tackifier and other functional additives constitutes a pressure sensitive adhesive and exhibits elastomeric properties. There is also provided in the composition an initiator systemnecessary to permit curing of the anaerobic pressure sensitive composition upon activation by the exclusion of oxygen. One or more accelerators for cure may also be provided. In one embodiment a component of the catalyst system may be either absent and provided later or latently present in microspheres which upon rupture will enhance the curing operation.

Anaerobic pressure sensitive adhesive composition

There is provided a curable anaerobic pressure sensitive adhesive composition, a mixture of a curable anaerobic system and a high molecular weight polymer system. The mixture which may include a tackifier and other functional additives constitutes a pressure sensitive adhesive and exhibits elastomeric properties. There is also provided in the composition an initiator system necessary to permit curing of the anaerobic pressure sensitive composition upon activation by the exclusion of oxygen. One or more accelerators for cure may also be provided. In one embodiment a component of the catalyst system may be either absent and provided later or latently present in microspheres which upon rupture will enhance the curing operation.

There are provided curable anaerobic pressure sensitive adhesive stocks in the form of sheets and tapes in which the adhesive is contained between two differential release surfaces. This construction permits total pressure sensitive adhesive transfer to a substrate which is to be firmly secured to another substrate upon the exclusion of oxygen and initiation of cure of the anaerobic resin. The compositions are those, based on the total weight of the composition, containing from about 4 to about 40 percent by weight of a first anaerobic resin having a viscosity up to about 1000 cps at 25.degree. C from 0 to about 80 percent by weight of a second anaerobic resin having a viscosity greater than about 1000 cps at 25.degree. C, from about 9 to 95 percent by weight of a thermoplastic resin system, from 0 to about 10 percent of a latent accelerator and about 0.1 to about 10 percent of a hydroperoxide catalyst, the composition having static shear at 0.25 in.sup.2 at a load of 250 gram greater than 10 minutes, a Polyken tack of greater than 700 grams, a loop tack greater than 1.5 lbs/in.sup.2 and a 180.degree. peel greater than 2 lbs. An external primer may be provided to accelerate cure.

Anaerobic pressure sensitive adhesive stocks

There are provided curable anaerobic pressure sensitive adhesive stocks in the form of sheets and tapes in which the adhesive is contained between two differential release surfaces. This construction permits total pressure sensitive adhesive transfer to a substrate which is to be firmly secured to another substrate upon the exclusion of oxygen and initiation of cure of the anaerobic resin. The adhesive layer provided may be homogeneous or heterogeneous, and there may be contained within the adhesive layer a support layer. The release liner employed is preferably impervious to migration of contained compounds which serve as the accelerators for cure of the curable anaerobic resin.

This invention concerns anaerobic compositions which contain acrylate ester monomers, peroxy polymerization initiators, a substituted thiourea, and an acidic substance and which exhibit improved ability to cure through relatively large gaps.

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West Hartford, CT, United States of America

Martin Hauser