Extrusion process for pressure-sensitive adhesive sheets and tapes
Abstract
Abstract THE BLOCK COPOLYMER IS PARTICULATE, AND IS BLENDED WITH A TACKIFIER RESIN IN PARTICLE FORM PRIOR TO EXTRUSTION UNDER CONDITIONS WHICH ALLOW THE PARTICLE SIZE OF THE RESPECTIVE COMPONENTS TO BE CONTROLLED. THE PROCESS FOR PRODUCING NORMALLY TACKY AND PRESSURESENSITIVE ADHESIVE SHEETS AND TAPES BY EXTRUDING AN ADHESIVE BASED UPON PARTICULAR TYPE OF A-B-A BLOCK COPOLYMER WHEREIN THE ADHESIVE IS EXTRUDED AT A MODERATE TEMPERATURE AND AT A CONTROLLED VISCOSITY AND THEN HOT DRAWN TO REDUCE ITS THICKNESS SUBSTANTIALLY, I.E., AS MUCH AS 20 OR MORE TIMES PRIOR TO LAMINATING IT WITH A BACKING SHEET. IN THE BLOCK COPOLYMER, A IS A THERMOPLASTIC POLYMER BLOCK DERIVED FROM STYRENE AND B IS ANE ELASTOMERIC POLYMER BLOCK DERIVED FROM ISOPRENE. PREFERABLY
Inventors
- 👤 R Korpman
Bibliographic Details
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