POLYURETHANE ELASTOMERS CONTAINING ALLOPHANATE-MODIFIED ISOCYNATES Russian patent published in 2011 - IPC C08G18/10 C08G18/20 C08G18/48 C08G18/78 B29C45/00 

FIELD: chemistry.

SUBSTANCE: present invention relates to a method of producing a polyurethane elastomer, involving reaction of a reaction mixture via reaction injection moulding, where the reaction mixture contains: (A) a polyisocyanate component, (B) an isocyanate-reactive component, in the presence of (C) a catalyst composition and, if needed, (D) one or more ultraviolet stabilisers and, if needed, (E) one or more pigments, wherein the relative amount of (A) and (B) is such that the isocyanate index ranges from approximately 100 to approximately 120. Component (A) contains: (I) allophanate-modified polyisocyanate having content of NCO groups ranging from approximately 15 to approximately 35 wt %, and containing a reaction product: (1) (cyclo)aliphatic polyisocyanate having content of NCO groups ranging from approximately 25 to approximately 60 wt %, with (2) organic alcohol selected from a group comprising aliphatic alcohols containing 1-36 carbon atoms, cycloaliphatic alcohols containing 5-24 carbon atoms, and aromatic alcohols containing approximately 7-12 carbon atoms, in which the alcohol group is not bonded directly to the aromatic carbon atom; or (II) a prepolymer of allophanate-modified polyisocyanate, where the prepolymer has content of NCO groups from approximately 10 to approximately 35 wt %, and contains a reaction product: (1) allophanate-modified polyisocyanate having content of NCO groups from approximately 15 to approximately 35 wt %, which is a reaction product: (a) (cyclo)aliphatic polyisocyanate having content of NCO groups from approximately 25 to approximately 60 wt %, and (b) organic alcohol selected from a group comprising aliphatic alcohols containing 1-36 carbon atoms, cycloaliphatic alcohols containing 5-24 carbon atoms, and aromatic alcohols containing approximately 7-12 carbon atoms, in which the alcohol group is not bonded directly to the aromatic carbon atom; with (2) an isocyanate-reactive component having functionality from approximately 2 to approximately 6 and molecular weight from approximately 60 to approximately 4000. Component (B) contains: (1) from approximately 70 to approximately 90 wt % per 100 wt % (B) one or more polyetherpolyols with low saturation, having functionality from approximately 2 to approximately 8, molecular weight from approximately 2000 to approximately 8000 and containing a maximum of 0.01 meq/g unsaturation, (2) from approximately 10 to approximately 30 wt % per 100 wt % (B) one or more organic compounds having molecular weight from approximately 60 to approximately 150, having hydroxyl functionality of approximately 2 and not containing primary, secondary and/or tertiary amine groups, and (3) from approximately 0 to approximately 5 wt % per 100 wt % (B) one or more organic compounds having molecular weight from approximately 200 to approximately 500, having functionality from 3 to 4 and containing amine-initiated polyetherpolyol. The catalyst composition (C) contains: (1) one or more catalyst of formula: , where: m is a whole number from 3 to 8, and n is a whole number from 3 to 8, and (2) at least one tin-based catalyst. The invention also describes the polyurethane elastomer itself, containing the reaction product of the above-mentioned components.

EFFECT: improved hardening and simple catalysis without the need for a lead-based catalyst, as well as obtaining elastomers with better flexural modulus and better weather resistance.

18 cl, 2 ex, 2 tbl