Process for preparing a thixotropic agent and its use
AssigneeBYK-Chemie GmbH
InventorsKarlheinz Haubennestel, Ulrich Orth
Life of this patent
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Abstract
The invention relates to a process for preparing a solution that is active as a thixotropic agent and contains urea urethanes, in which monohydroxyl compounds are reacted with an excess of toluene diisocyanate, the unreacted portion of the toluene diisocyanate is removed from the reaction mixture and the monosiocyanate adduct obtained is further reacted with diarines in the presence of a lithium salt to form urea urethanes. The invention also relates to the use of the solution for imparting thixotropic properties to coating compounds.
Claims10
A process for preparing a urea urethane thixotropic agent comprising reacting a urethane-isocyanate having the formula:
- with a diamine having the formula:
- H2N—R″—NH2,
- or
- where R is n-C4-22alkyl, isoC4-22alkyl, C6-12cycloalkyl, C7-12aralkyl, CmH2m+1(O—CnH2n)x— or CmH2m+1(OC(═O)—CvH2v)x—;
- R″ is —CYH2y;
- and
- R′″ is CH3— or H,
- wherein y is from 2 to 12;
- m is from 1 to 22;
- n is from 2 to 4;
- x is from 1 to 15;
- and v is 4 or 5, in the presence of a lithium salt;
- provided that the urethane-isocyanate has had unreacted diisocyanate removed prior to reaction with the diamine.
Dependencies are inferred from the claim text.