Pressure-sensitive adhesives
AssigneeNeutron Products, Inc.
InventorsJeffrey D. Williams, Marvin L. Young, Syed S. Ahmad, Jackson A. Ransohoff
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Abstract
Acrylate-based pressure-sensitive adhesives are produced by a process in which a liquid, polymerizable monomer composition containing at least one acrylate monomer is placed in a closed reaction vessel, deaerated and the monomer(s) are polymerized by exposure to ionizing radiation such as gamma irradiation. The process allows for the direct production of low-solvent or solventless acrylate-based adhesives suitable for application by hot-melt techniques.
Claims20
A process for preparing a substrate for bonding which comprises applying to the substrate by hot-melt application a pressure-sensitive adhesive which is produced by the process which comprises:
- (a) introducing, to a sealable reaction vessel, a liquid, polymerizable monomer composition, comprising:
- (i) from 65 to 100 parts of at least one acrylate monomer of the formula:
- ##STR3## wherein R.sup.1 is hydrogen or methyl and R.sup.2 is a straight or branched chain alkyl having from 2 to 8 carbon atoms,
- (ii) from 0 to 35 parts of at least one ethylenically unsaturated comonomer per 100 parts of liquid polymerizable monomer composition;
- and
- (b) dearating the liquid polymerizable monomer composition before or after introducing it into the vessel;
- and
- (c) polymerizing the monomers in the containers by exposing them to ionizing radiation, at a dose rate greater than 1 kilorad per hour and less than 1 kilorad per second, said polymerization being carried out in the presence of less than 30% by weight of an organic solvent, based on the combined weight of the liquid, polymerizable monomer composition and solvent, so as to produce a viscoelastic polymer mass having a low level of residual monomer and oapable of hot-melt application.
Dependencies are inferred from the claim text.