摘要 |
Reactive thermoplastic welding aid, preferably in the form of film, based on known resin/polyurethane/EVA copolymer mixtures. The system also contains a reactive acrylate, polybutadiene resin, epoxy resin or other reactivatable or still reactive prepolymer, optionally together with heat-stable accelerators. These thermolytically-labile resin systems are unreactive at extrusion temperature, and the resin system and activation temperature are chosen so that crosslinking to the elastomer only occurs at 160 deg C or above for heat-cured compositions, or on exposure to UV light or electron beam radiation. Preferably the reactive acrylate contains an ester-PU system which undergoes thermal decomposition with the formation of reactive, crosslinking NCO groups. The polymer mixture may also contain a photosensitiser and a thermally stable peroxide, providing chemical activation when exposed to light with a wavelength of 200-600 nm or to electron beam radiation. This enables crosslinking with electron beam radiation in the range of 20-200 kKay at a throughput speed of 0.1-2.2 m/min. Further crosslinking may be obtained by a combination of heat and electron beam radiation.
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申请人 |
SIKA WERKE GMBH, 04129 LEIPZIG, DE |
发明人 |
KAPS, RAINER, DR., 04109 LEIPZIG, DE;MOECKEL, PETER, DR., 04469 LUETZSCHENA, DE;KOCH, KARLHEINZ, 06110 HALLE, DE;SCHNELLENBERGER, MICHAEL, DIPL.-CHEM., 04277 LEIPZIG, DE;SONNTAG, KAY, DIPL.-CHEM., 04329 LEIPZIG, DE |