초록 ▼

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 a

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°C from 0 to about 80 percent by weight of a second anaerobic resin having a viscosity greater than about 1000 cps at 25°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 in2 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/in2 and a 180°peel greater than 2 lbs. An external primer may be provided to accelerate cure.

대표청구항 ▼

An anaerobic pressure sensitive adhesive stock comprising: a. a first release coating on a self-supporting release liner; b. a transferable and curable pressure sensitive adhesive layer having one surface in contact with said first release coating, said pressure sensitive adhesive layer comprising:

An anaerobic pressure sensitive adhesive stock comprising: a. a first release coating on a self-supporting release liner; b. a transferable and curable pressure sensitive adhesive layer having one surface in contact with said first release coating, said pressure sensitive adhesive layer comprising: i. from about 9 to about 95 percent by weight of the layer of a thermoplastic resin system containing at least one thermoplastic polymer selected from the group consisting of vinyl homopolymers, vinyl copolymers, polyurethanes, polyesters, polyamides, acrylic polymers, natural elastomers, and synthetic elastomers; ii. from about 4 to about 40 percent by weight of the layer of a first anaerobic resin system, containing at least one curable anaerobic resin having a viscosity from about 5 to about 1000 cps at 25°C. and a vinyl equivalent number from about 80 to about 2000 and from 0 to about 80 percent by weight of the layer of a second anaerobic resin system containing at least one of a curable anaerobic resin having a viscosity greater than 1000 cps at 25°C., at least one anaerobic resin in the first and second anaerobic resin system containing at least two polymerizable acrylic ester groups, each individually having the formula: [Figure] wherein R2 is a radical selected from the group consisting of hydrogen, halogen and a lower alkyl containing from 1 to about 4 carbon atoms, the said anaerobic resins being present in an amount of from about 4 to about 90 percent by weight of the layer; iii. from about 0.1 to about 10 percent by weight of the layer of a peroxy initiator to initiate cure of the contained anaerobic resins upon the substantial exclusion of oxygen; and iv. from 0 to about 10 percent by weight of the layer of an organonitrogen compound as a latent accelerator in the cure of the contained anaerobic resins, and said pressure sensitive adhesive layer providing a static shear strength of at least 10 minutes at a 250 gram load per 0.25 square inch, a 180°peel value of at least about 2 pounds; a Polyken tack of at least about 700 gram and a loop tack of at least about 1.5 lbs. per in2 prior to cure of said anaerobic resin system; and c. a second release coating on a self-supporting releaSe liner in contact with the opposed surface of said transferable pressure sensitive adhesive layer, the bond of the first release coating to the transferable pressure sensitive adhesive layer being less than the cohesive strength of said pressure sensitive adhesive layer and exceeding the bond of said second release coating for said pressure sensitive adhesive layer to permit the pressure sensitive adhesive layer to be preferentially separated from said second release coating for application and bonding to a substrate prior to separation of the pressure sensitive adhesive layer from said first release coating without cohesive failure of said pressure sensitive adhesive layer.