Impermeable molded articles of cellular polyurethane elastomers produced with organofunctional polysiloxane-derivatives and their use as spring elements
AssigneeBayer Aktiengesellschaft
InventorsPaul Henrichs, Peter Haas, Hans-Georg Hoppe, Wolfgang Grimm
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Abstract
This invention relates to an improved method of producing impermeable cellular polyurethane elastomers from polyisocyanates, relatively high molecular weight polyhydroxyl compounds and water as chain lengthening and blowing agent to which additional chain lengthening agents may be added and it is characterized by the use of certain silicone derivatives. The new method makes it possible for impermeable cellular molded articles to be produced without the necessity of forming a skin on the surface, of the kind known, for example, in integral skin foams.
Claims12
A method of producing an impermeable, fine cellular polyurethane elastomer having a density of from 0.3 to 0.8 g/cm.sup.3 comprising reacting
- (A) organic polyisocyanates,
- (B) polyhydroxyl compounds having a molecular weight of from 400 to 6000, and
- (C) water, the equivalent ratio of isocyanate groups to isocyanate reactive compounds in the formulation being within the range of from 0.95:1 to 1.15:1, characterized in that from 0.1 to 3% by weight of one or more organofunctional polysiloxanes corresponding to the general formula ##STR9## in which m represents an integer of from 1 to 500, the groups
- Z which may be the same or different represent C.sub.1 -to C.sub.5 -alkyl or C.sub.6 -to C.sub.15 -aryl or siloxyl groups and the groups
- X have the same meaning as Z, with the proviso that at least 1, but not more than 5 of the radicals X represent H--Y--R groups, in which
- Y represents --NR'--, --O-- ##STR10## or --S--, R represents a C.sub.1 -to C.sub.6 -alkylene group which may contain hetero atoms, and
- R' represents hydrogen, a C.sub.1 -to C.sub.6 -alkyl group or a C.sub.5 -to C.sub.9 -cycloalkyl group
- are added to the reaction mixture.
Dependencies are inferred from the claim text.