Moisture curing polyurethane hot-melt adhesive

US5965662A · kind A · utility

Assignee

• Henkel Kommanditgesellschaft auf Aktien · DE

Inventors

• Michael Krebs · Hilden, DE
• Roland Heider · Hilden, DE
• Klaus Schillings · Langenselbold, DE
• Michael A. P. Gansow · Wetzikon, CH

Key dates

• Filing date: Nov 10, 1997
• Grant date: Oct 12, 1999
• Expiry date: Nov 10, 2017

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08L2666/26
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

The hotmelt adhesive according to the invention contains PA0 A) at least one polyurethane prepolymer of PA1 a) at least one polyisocyanate, more particularly toluene diisocyanate and/or MDI, PA1 b) at least one polyalkylene glycol in a concentration of more than 10% by weight, based on the hotmelt adhesive as a whole, more particularly polypropylene glycol, PA1 c) at least one polyester glycol, preferably at least two polyester glycols with different glass transition temperatures and PA1 d) at least one chain extender and PA0 B) optionally additives, such as PA1 e) a resin, more particularly a hydrocarbon resin, and PA1 f) a stabilizer, more particularly toluene sulfonyl isocyanate. The hotmelt adhesive preferably has a melt viscosity of 4 to 100 Pa.cndot.s at 170.degree. C. The PU prepolymer has only one Tg in the DSC curve. The hotmelt adhesive is distinguished by high creep resistance and high early and ultimate strengths. Accordingly, it is mainly used in the shoe industry, more particular, in application machines designed for application in the shoe production line which does not contain any steam-operated preliminary crosslinking stage or a drying tunnel. The hotmelt adhesive…