Pressure-sensitive adhesive tape product

Claim 2

The invention of claim 2 wherein the nucleating agent is fumed silica.

Claim 3

The invention of claim 2 wherein the backing functions as a temporary carrier, being removable from the adhesive layer after the exposed surface thereof has been applied to a substrate, thereby providing a highly conformable transfer adhesive.

Claim 4

The invention of claim 2 wherein each major surface of said backing is provided with similar adhesive layers, each being firmly adherently bonded to said backing.

Claim 5

In the manufacture of adhesive sheet material wherein a layer of normally tacky and pressure-sensitive adhesive is applied to a sheet backing, the improvement which comprises: including in said adhesive, uniformly distributed throughout, from 2 to 15 percent by weight of a blowing agent which decomposes to yield gas when subjected to heat and from 1 to 10 percent by weight of a finely divided nucleating-reinforcing agent around which bubbles of said gas can form; whereby said adhesive layer can be heated to increase its thickness by at least one-third by the formation of microscopic closed cells, thereby enabling the surface of said adhesive layer to conform to irregular surfaces.

Claim 6

The invention of claim 6 wherein the blowing agent is N,N''-dimethyl-N,N''-dinitrosoterephthalamide.

Claim 7

The invention of claim 7 wherein the nucleating-reinforcing agent is fumed silica.

Claim 8

A joint comprising in coMbination two juxtaposed incompletely parallel surfaces which have disposed therebetween, uniformly in contact therewith and firmly united said surfaces, an adhesive layer comprising a normally tacky and pressure-sensitive adhesive throughout which are distributed a multiplicity of spheroidal cells having an average diameter on the order of 30 to 300 microns and being present in an amount such as to constitute at least 25 percent of the volume of said layer, the walls of said cells being defined by said adhesive.

Claim 9

The joint of claim 9 wherein a sheet backing member is centrally disposed within the adhesive layer and firmly adherently bonded thereto.

Claim 10

A roll of tape formed from an elongate strip of normally tacky and pressure-sensitive adhesive sheet material wound convolutely upon itself about an annular core and readily unwindable therefrom, said roll being storable for several months on edge without substantial permanent deformation, said strip comprising in combination: a sheet backing having firmly adherently bonded to one major surface thereof a layer of normally tacky and pressure-sensitive adhesive, said adhesive layer; being smooth-surfaced and having substantially uniformly distributed throughout, so as to constitute from 40 to 70 percent of the volume of said layer, a multiplicity of autogenous spheroidal closed cells having an average diameter on the order of 60 to 120 microns, the walls of said cells being defined by said adhesive; having distributed throughout from 1 to 10 percent by weight of fumed silica particles, and being further characterized by compressibility and less than about 5 percent recovery in thickness when compressed to half its original thickness; whereby said tape displays excellent adhesion to even irregular substrates to which it is applied under very light pressure, outstanding adhesion when removed from substrates at high speeds, and superior impact resistance.

Claim 11

The tape of claim 11 wherein the backing comprises strong lineally aligned filaments.