Polyurethane cast elastomers based on durene diisocyanate
AssigneeBayer Aktiengesellschaft
InventorsPeter Heitkämper, Klaus Jost, Eduard Mayer, Thomas Münzmay, Joachim Wagner, Christian Wolfrum
Life of this patent
Estimating the term…
Abstract
The present invention relates to polyurethane cast elastomers which are prepared from higher molecular weight polyhydroxy compounds, durene diisocyanate and low molecular weight chain-lengthening and/or crosslinking agents. These elastomers are particularly useful for the production of moldings exposed to high mechanical stresses.
Claims6
A molded or cast article capable of withstanding high mechanical stress produced from a cellular polyurethane elastomer having a density within the range of from about 0.2 to about 1.1 g/cm3 which comprises a reaction product of:
- a) from about 85 to about 90 wt. %, based on the total weight of the reaction product, of at least one higher molecular weight polyhydroxyl compound having an average molecular weight of from 500 to 6,000 and a functionality of at least 2;
- b) from about 10 to about 25 wt. %, based on the total weight of the reaction product, of 2,3,5,6-tetramethyl-1,4-diisocyanatobenzene;
- and
- c) from about 0.2 to about 10 wt. %, based on the total weight of the reaction product, of at least one low molecular weight chain-lengthening and/or crosslinking agent having at least two hydroxyl groups and an average molecular weight of from 60 to 800,
- with the proviso that the at least one chain-lengthening and/or crosslinking agent may not be water.
A molded or cast article capable of withstanding high mechanical stress produced from a cellular polyurethane elastomer having a density within the range of from about 0.2 to about 1.1 g/cm3 which comprises the reaction product of:
- a) from about 65 to about 90 wt. %, based on the total weight of reaction product, of at least one higher molecular weight polyhydroxyl compound having an average molecular weight of from 500 to 6,000 and a functionality of at least 2;
- b) from about 10 to about 25 wt. %, based on the total weight of reaction product, of at least one 2,3,5,6-tetramethyl-1,4-diisocyanatobenzene;
- and
- c) from about 0.2 to about 10 wt. %, based on the total weight of reaction product, of water and/or at least one low molecular weight chain-lengthening and/or crosslinking agent having at least two hydroxyl groups and an average molecular weight of from 60 to 800;
- wherein the higher molecular weight polyhydroxyl compound a) is reacted with the diisocyanate b) in the presence of a chain-lengthening and/or crosslinking agent c) to produce an isocyanate-terminated prepolymer.
Dependencies are inferred from the claim text.