Process for preparing adhesive using planetary extruder

An adhesive composition made according to a process comprising:

• introducing a natural rubber, a synthetic rubber, or blends thereof into a planetary roller extruder, the natural rubber, the synthetic rubber, or the blend thereof having an initial molecular weight;
• masticating the natural rubber, the synthetic rubber, or the blends thereof in the planetary roller extruder such that the initial molecular weight thereof is reduced by about 50% to about 80%;
• adding a combination of an ionizing radiation crosslinker and a heat-activatable chemical crosslinker to the natural rubber, the synthetic rubber, or the blends thereof;
• continuously producing a homogeneous adhesive composition while maintaining the temperature of the adhesive composition between about 25° C. and 100° C.;
• applying the homogeneous adhesive composition to a web-form material;
• and
• activating the ionizing radiation crosslinker to crosslink the adhesive composition;
• wherein the heat-activatable chemical crosslinker remains generally unactivated such that it is a residual latent curing agent available for later activation.

A process for preparing an adhesive comprising the steps of:

• introducing primary raw materials comprising a non-thermoplastic elastomer into a feeding section of a planetary roller extruder;
• conveying the primary raw materials from the feeding section to a compounding section of the planetary roller extruder;
• mixing the primary raw materials in the compounding section;
• providing a first means of crosslinking by adding a heat-activatable crosslinker to the compounding section;
• providing a second means of crosslinking by adding an ionizing radiation crosslinker to the compounding section;
• continuously producing a homogeneous adhesive composition while maintaining the temperature of the adhesive composition between about 25° C. and 100° C.;
• applying the homogeneous adhesive composition to a web-form material;
• and
• g) exposing the web-form material with the applied composition to ionizing radiation thereby crosslinking the adhesive composition with the ionizing radiation crosslinker;
• wherein the non-thermoplastic elastomer is masticated during mixing in the compounding section such that its Mw is reduced by about 50% to about 80% and the heat-activatable chemical crosslinker remains generally unactivated such that it is a residual latent curing agent available for later activation.