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US 6,653,395 B1Granted
Orthoester-based polymer as well as preparation and use thereof
AssigneeAkzo Nobel N.V.
InventorsKarin Bergstrom, Per-Erik Hellberg
Life of this patent
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Abstract
The present invention relates to new orthoester-based block polymers having a good antifoaming effect in liquid aqueous systems. The compounds are easily biologically degradable and, compared with traditional block polymers, have a comparatively high cloud point, which makes them readily compatible with other compounds and facilitates the formulation of homogeneous compositions. The new polymers are characterized in that they contain a block of at least 4 alkyleneoxy groups having 3 and/or 4 carbon atoms.
Claims8
An orthoester-based polymer having the general formula
- wherein R1 is hydrogen or a hydrocarbon group having 1-4 carbon atoms;
- R2 is a group (A)nY, where each A is an ethyleneoxy group or a higher alkyleneoxy group having 3-4 carbon atoms, and each Y is hydrogen or an alkyl group having 1-4 carbon atoms, provided that when Y is hydrogen, n is a number from 1 to 100, R3 and R4 are groups of the formula (A)nY, where A, n and Y have the above meaning, or a di- or polycondensate of the polymer via free hydroxyl groups in R2, R3 or R4, the total sum of all n being 8-2, 500, and that at least one of the groups R2, R3 and R4 contains at least one block of at least 4 alkyleneoxy groups having 3 and/or 4 carbon atoms.
Dependencies are inferred from the claim text.