Manufacturing method, and high-molecular quantitative allophanate and its prepolymer null general constitutional formula of high-molecular quantitative

摘要

Polymeric allophanate based on diphenylmethane diisocyanate is produced by reacting hydroxy (OH)-group containing compound(s) and diphenylmethane diisocyanate in the presence of allophanate catalyst at a temperature of 80-110[deg]C to form allophanate-modified diphenylmethane diisocyanate; and cooling the allophanate-modified diphenylmethane diisocyanate to a temperature of 20-70[deg]C for 1 hour to 30 days. Production of polymeric allophanate based on diphenylmethane diisocyanate having isocyanate (NCO) group (12-30 wt.%) comprises reacting hydroxy (OH)-group containing compound(s) and diphenylmethane diisocyanate in the presence of allophanate catalyst at a temperature of 80-110[deg]C to form allophanate-modified diphenylmethane diisocyanate; and cooling the allophanate-modified diphenylmethane diisocyanate to a temperature of 20-70[deg]C for 1 hour to 30 days to form a polymeric allophanate based on diphenylmethane diisocyanate. The OH-group containing compound(s) is from aliphatic alcohols, aromatic alcohols, and/or aliphatic diols. The diphenylmethane diisocyanate comprises (wt.%) 2,4'-diphenylmethane diisocyanate (0-60), 2,2'-diphenylmethane diisocyanate (less than 6), and the balance is 4,4'-diphenylmethane diisocyanate. An independent claim is also included for a polymeric allophanate based on diphenylmethane diisocyanate comprising allophanate-modified isocyanate based on diphenylmethane isocyanate (MDI) having NCO group content of 20-32%.