LOW VISCOSITY POLYURETHANE PREPOLYMER BASED ON 2,4'-MDI

• Main Authors: KRAUS HARALD DR, WINTERMANTEL MATTHIAS, MATNER MATHIAS, KOBELKA FRANK, MECKEL WALTER
• Format: Patent
• Language: English
• Published: 09.02.2006
• Subjects: ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; ADHESIVES; CHEMISTRY; COMPOSITIONS BASED THEREON; DYES; MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONSONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS; MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FORELSEWHERE; METALLURGY; MISCELLANEOUS APPLICATIONS OF MATERIALS; MISCELLANEOUS COMPOSITIONS; NATURAL RESINS; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ORGANIC MACROMOLECULAR COMPOUNDS; PAINTS; POLISHES; THEIR PREPARATION OR CHEMICAL WORKING-UP; USE OF MATERIALS AS ADHESIVES

PROBLEM TO BE SOLVED: To provide a 2,4'-MDI prepolymer having a low viscosity and a low monomer content, to provide a moisture-curable sealant based on the 2,4'-MDI prepolymer, to provide their production method, and to provide their uses. SOLUTION: This method for producing an MDI-based prepolymer not containing a carboxylate group and having a shear viscosity of <100,000 mPa s at 23°C comprises reacting (A) an MDI type isocyanate containing 2,4'-MDI in an amount of ≥95 wt.% with (B) a polyetherpolyol mixture of (b1) a polyetherpolyol having a number-average mol.wt. Mnof 2,000 to 20,000 and an average OH functional value of 3 to 8 with (b2), if necessary, a polyetherpolyol having an Mnof >2,000 g/mol, wherein the (b1) fraction of (B) is ≥20 wt.%, and the total functional value based on OH groups and Mnare >2 and 3,000 to 20,000 g/mol, respectively. COPYRIGHT: (C)2006,JPO&NCIPI