公开(公告)号：DE2301175A1

公开(公告)日：1974-08-01

申请号：DE2301175

申请日：1973-01-11

Applicant: BASF AG

Inventor： RICHTER PETER DR ,  WIGGER AUGUST DR ,  ELZER ALBERT DR ,  VOLKERT OTTO DR

IPC: C08F283/00 ,  G03F7/00 ,  G03F7/035 ,  G03F7/11

Abstract: 1454191 Presensitized flexographic printing plates BASF AG 10 Jan 1974 [11 Jan 1973] 01168/74 Heading G2C A presensitized plate comprises a base, a non- photocrosslinkable elastomeric polymer intermediate layer 0À1-6 mm thick (i) having a Shore A hardness of 15-70 which is at least 20 below the Shore A hardness of the photocrosslinkable layer (below) in photocrosslinked state, (ii) being insoluble in the developer (below) and (iii) being bonded to the base, and a photocrosslinkable layer comprising a photoinitiator-containing photocrosslinkable material which comprises one or more polymers having in admixture therewith one or more photocrosslinkable monomers compatible with the polymer(s) and having one or more C-C multiple bonds 0À1-6 mm thick having the following features: (i) all or a major proportion by weight of its content of the polymer(s) consists of a polyurethane elastomer soluble in a developer and produced using one or more aliphatic polyisocyanates, (ii) the Shore A hardness of its material when photocrosslinked is 50-90 and (iii) it is bonded to the intermediate layer above. The photocrosslinkable layer may comprise 70-90 wt. per cent of the polymer(s) and 10-30 wt. per cent of the monomer(s), based on the weight of polymer(s) plus monomer(s). The base may be flexible or rigid, may or may not reflect actinic exposing radiation and may be steel, aluminium or polyester. The intermediate layer may comprise natural rubber, styrene-butadiene rubber, polybutadiene rubber, butadiene-acrylonitrile rubber, elastomeric ethylene-propylene copolymer, elastomeric propylene oxide polymer, silicone rubber, polysulphide rubber (see Example 4), elastomeric vinylidene fluoride - hexafluoropropylene copolymer, nitrile rubber (see Example 5) or polyurethane (see Examples 1-3) which may be derived from an aromatic diisocyanate e.g. toluylenediisocyanate. The photocrosslinkable layer may contain a dye e.g. Zapon Fast Black (see Example 4). After exposure and development the relief printing plate produced may be re-exposed for 10 minutes before it is dried for 20 minutes at 70‹C in a freshair dryer (see Examples 2, 4 and 5). Reference by way of disclaimer is made to 201/74.