摘要:
Laminates for the production of relief plates for flexographic printing, by imagewise exposure and washing out with a developer solution have, on a base optionally provided with an elastomeric layer, a photo-crosslinkable layer containing a photoinitiator and consisting of a polyurethane elastomer which has been prepared in a special manner from an aliphatic saturated polyesterglycol, an aliphatic diisocyanate, but-1-ene-3,4-diol and, if desired, another diol and which has a Shore A hardness of 30 to 90.degree. in the photo-crosslinked state, the elastomer being optionally mixed with a photo-crosslinked monomer.
摘要:
A process for the manufacture of thin layers based on polyurethane elastomers. A liquid reaction mixture essentially consisting of (A) polyesters, polyethers, polyester urethanes or polyether urethanes, all of which contain at least two hydroxyl groups in the molecule, and diisocyanates or (B) prepolymers obtained from the hydroxyl-containing compounds mentioned under (A) above with an excess of diisocyanates, said prepolymers containing at least two isocyanate groups in the molecule, and at least one of the compounds mentioned under (A) above which are capable of reacting with isocyanates, to which reaction mixture a minor quantity of substantially compatible monomers having at least two photocrosslinkable C--C multiple bonds and optionally a photopolymerization initiator have been added, is applied to a substrate to form a coating thereon, which coating is then gelled by irradiation and finally thermocured. The process of the invention is particularly suitable for the continuous manufacture of uniformly thin layers of soft polyurethane elastomer showing narrow tolerance limits.
摘要:
A process for the production of plastic foams, preferably rigid foams containing urethane groups or urethane and isocyanurate groups, by reactinga) an organic and/or modified organic polyisocyanate withb) at least one relatively high-molecular-weight compound containing at least two reactive hydrogen atoms, and, if desired,c) a low-molecular-weight chain extender and/or cross-linking agent,in the presence ofd) a blowing agent,e) a catalyst and, if desired,f) assistants and/or additives,in which the blowing agent (d) used is at least one vinylfluoroalkane of the formula CH.sub.2 .dbd.CH--C.sub.n F.sub.2n+1 in which n is an integer from 1 to 6, (di), or a mixture of at least one such vinylfluoroalkane (di) and at least one further physical and/or chemical blowing agent (dii) which is different from (di), blowing agent-containing emulsions which contain at least one vinylfluoroalkane and at least one starting component (a), (b), (c) or (b) and (c) and said plastic foams containing at least one vinylfluoroalkane as insulating gas.
摘要翻译:通过使a)有机和/或改性的有机多异氰酸酯与b)至少一种相对高分子量的化合物(其包含至少两种以上的化合物)反应,生产塑料泡沫,优选含有氨基甲酸酯基或氨基甲酸酯和异氰脲酸酯基团的刚性泡沫的方法 反应性氢原子,如果需要,c)低分子量增链剂和/或交联剂,在d)发泡剂存在下,e)催化剂,如果需要,f)助剂和 其中使用的发泡剂(d)是至少一种式CH 2 = CH-C n F 2n + 1的乙烯基氟烷烃,其中n是1至6的整数,(di),或至少一种 这种乙烯基氟烷烃(二)和至少一种不同于(二)的物理和/或化学发泡剂(dii),含有至少一种乙烯基氟烷烃和至少一种起始组分(a)的发泡剂的乳液,( b),(c)或(b)和(c)和所述含有至少一种乙烯基芴的塑料泡沫 oralkalk作为绝缘气体。
摘要:
A process for the preparation of cellular plastics, preferably hard structural polyurethane foams, by the polyisocyanate polyaddition process involves reactinga) an organic and/or modified organic polyisocyanate withb) at least one high-molecular-weight compound containing at least two reactive hydrogen atoms and, if desired,c) a low-molecular-weight chain extender and/or cross-linking agent,in the presence ofd) a blowing agent from the group comprising tertiary alcohols (di), preferably tertiary butanol, or a mixture of at least one tertiary alcohol (di) and water (dii),e) a catalyst and, if desired,f) assistants and/or additives.
摘要:
Novel esters containing bonded fluorocarbon and oxypropylenealkylether groups and of the formula ##STR1## where Rf is straight-chain or branched, partially fluorinated or perfluorinated alkyl of 2 to 10 carbon atoms, partially fluorinated or perfluorinated cycloalkyl of 4 to 8 carbon atoms,perfluorophenyl orperfluoroalkylphenyl where the perfluoroalkyl radical is of 1 to 6 carbon atoms,R is straight-chain or branched alkyl of 1 to 4 carbon atoms andn is an integer from 2 to 70,blowing agent-containing emulsions which have a long shelf life and contain at least one partially fluorinated or perfluorinated (cyclo)aliphatic hydrocarbon of 3 to 8 carbon atoms and/or sulfur hexafluoride, at least one unmodified or modified organic polyisocyanate or a relatively high molecular weight reactive hydrogen compound and at least one of the abovementioned carboxylic or carbamic esters, and the use of these emulsions for the preparation of cellular plastics by the polyisocyanate polyaddition method.
摘要:
Emulsifier-free aqueous polyurethane dispersions are prepared by reacting (a) dihydroxy compounds, (b) diisocyanates and (c) chain extenders to give a prepolymer having terminal isocyanate groups, then reacting the prepolymer with (d) salts of aliphatic aminocarboxylic or -sulfonic acids or amino-containing or hydroxyl-containing tertiary ammonium salts, dispersing the resulting polyurethane in water and, if required, removing the organic solvent by distillation. In the process, an organic condensation resin which is dissolved in a solvent is admixed before the polyurethane obtained is dispersed in water.
摘要:
Compositions polymerizable by ultraviolet irradiation which contain photopolymerizable monomers possessing at least one polymerizable carbon-carbon multiple bond and monoketals of the formula ##STR1## as photoinitiators. The compositions have a particularly long shelf life and show very little yellowing after curing by irradiation.
摘要:
A process for producing moldings containing ester and urethane groups and having a cellular core and a compacted surface zone, preferably shoe soles, comprises reactinga) isocyanate semiprepolymers containing ester groups and having an isocyanate content of from 10 to 26% by weight, which in turn are prepared by reactingai) 4,4'-MDI or mixtures of 4,4'-MDI and modified or unmodified MDI isomers,withaii) difunctional to trifunctional polyester polyols having molecular weights of from 600 to 3000 andaiii) at least one branched-chain dihydroxy compound containing at least one bonded ester unit as bridge and having a molecular weight of up to 500,withb) at least one relatively high molecular weight polyhydroxyl compound and, if desired,c) low molecular weight chain extenders and/or crosslinkers in the presence ofd) blowing agents,e) catalystsand, if desired,f) additives in a closed mold with compaction. The isocyanate semiprepolymers containing ester groups which can be used in this process are liquid at room temperature.
摘要:
A process for the production of plastic foams, preferably rigid foams containing urethane groups or urethane and isocyanurate groups, by reactinga) an organic and/or modified organic polyisocyanate withb) at least one relatively high-molecular-weight compound containing at least two reactive hydrogen atoms, and, if desired,c) a low-molecular-weight chain extender and/or cross-linking agent,in the presence ofd) a blowing agent,e) a catalyst and, if desired,f) assistants and/or additives,in which the blowing agent (d) used is at least one vinylfluoroalkane of the formula CH.sub.2 .dbd.CH--C.sub.n F.sub.2n+1 in which n is an integer from 1 to 6, (di), or a mixture of at least one such vinylfluoroalkane (di) and at least one further physical and/or chemical blowing agent (dii) which is different from (di), blowing agent-containing emulsions which contain at least one vinylfluoroalkane and at least one starting component (a), (b), (c) or (b) and (c) and said plastic foams containing at least one vinylfluoroalkane as insulating gas.
摘要:
A process for the production of plastic foams, preferably rigid foams containing urethane groups or urethane and isocyanurate groups, by reactinga) an organic and/or modified organic polyisocyanate withb) at least one relatively high-molecular-weight compound containing at least two reactive hydrogen atoms, and, if desired,c) a low-molecular-weight chain extender and/or crosslinking agent,in the presence ofd) a blowing agent,e) a catalyst and, if desired,f) assistants and/or additives,in which the blowing agent (d) used is at least one vinylfluoroalkane of the formula CH.sub.2 .dbd.CH--C.sub.n F.sub.2n+1 in which n is an integer from 1 to 6, (di), or a mixture of at least one such vinylfluoroalkane (di) and at least one further physical and/or chemical blowing agent (dii) which is different from (di), blowing agent-containing emulsions which contain at least one vinylfluoroalkane and at least one starting component (a), (b), (c) or (b) and (c) and said plastic foams containing at least one vinylfluoroalkane as insulating gas.
摘要翻译:通过使a)有机和/或改性的有机多异氰酸酯与b)至少一种相对高分子量的化合物(其包含至少两种以上的化合物)反应,生产塑料泡沫,优选含有氨基甲酸酯基或氨基甲酸酯和异氰脲酸酯基团的刚性泡沫的方法 反应性氢原子,如果需要,c)低分子量增链剂和/或交联剂,在d)发泡剂存在下,e)催化剂,如果需要,f)助剂和/或 其中使用的发泡剂(d)是至少一种式CH 2 = CH-C n F 2n + 1的乙烯基氟烷烃,其中n是1至6的整数,(di)或至少一种这样的乙烯基氟烷烃的混合物 (二)和至少一种不同于(二)的物理和/或化学发泡剂(dii),含有至少一种乙烯基氟烷烃和至少一种起始组分(a)的发泡剂的乳液,(b) ,(c)或(b)和(c)和所述含有至少一种乙烯基纤维的塑料泡沫 罗烷作为绝缘气体。