| 摘要 |
FIELD: chemistry.SUBSTANCE: present invention relates to a polyurethane composition for producing holographic media. Said composition contains: A) a polyisocyanate component; B) an isocynate reactive component, which contains hydroxy functional multi-block copolymers B1) of the type Y(X-H)with i=1-10 and n= 2-8 and number-average molecular weight greater than 1000 g/mol, wherein segments Xare respectively built from alkylene oxide links of formula (I): -CH-CH(R)-O- formula (I), wherein R is hydrogen, an alkyl or aryl residue, which can be substituted or interrupted with a heteroatom (e.g. ether oxygen), Y is the base of the starter unit and the fraction of segments Xrelative the total amount of segments Xand Y is at least 50 wt %; C) compounds having a refraction index n?>1.55 and contain groups which react under the action of actinic radiation with ethylenically unsaturated compounds with polymerisation (radiation-cured groups) and do not contain NCO- groups themselves; D) radical stabilisers; E) photoinitiators; F) optionally catalysts; G) optionally auxiliary substances and additives. The invention also describes a method of producing media for recording visual holograms, media for recording visual holograms, use of such a medium and a method of recording holograms.EFFECT: obtaining a polyurethane composition which, without detriment to compatibility of the matrix polymer and the recorded monomer, provides a better contrast ratio and improved hologram brightness.12 cl, 2 dwg, 5 ex |
