Title: PROCESSES FOR MOISTURE SCAVENGING IN PREPARING POLYURETHANE COATINGS AND COMPOSITIONS THEREFOR
Number/Link: US2017/0114247
Applicant/Assignee: Achiewell
Publication Date: 27-april-2017
“Gist”: Methoxysilicon compound with e-withdrawing group together with hydrophobic t-amine catalyst acts as moisture scavenger
Why it is interesting: Moisture in PU coating compositions can be a problem because it negatively affects both the properties of the composition (pot life and viscosity..) and of the final coating. Moisture scavengers like molecular sieves are well known but often have a negative impact as well. According to this invention, methoxyorganosilicon compounds with at least one electron withdrawing group attached to the silicon atom act as efficient moisture scavengers when used in combination with a hydrophobic tert-methylamine catalyst. Preferred organosilicon compounds have 3 methoxy substituents and one hydrocarbon-based e-withdrawing group, like e.g. fluoroethyltrimethoxysilane. A preferred catalyst is 1,3-bis[3-dimethylaminopropyl]urea (claimed). No examples are given.