Structural polyurethane adhesive

Structural polyurethane adhesive

Keywords: Patent, Adhesives

Applicant: Lord Corporation, USAPatent number: US6,423,810Publication date: 23 July 2002Title: High strength, long-open time structural polyurethane adhesive and method of use thereof

This patent describes a two-part polyurethane structural adhesive having a long open time, and a method of bonding structural components.

The adhesive composition comprises an isocyanate or isocyanate prepolymer and a polyol mixture. The polyol mixture contains a polyol having secondary hydroxyl functionality by way of a long chain secondary polyol, forming at least 75 per cent of the weight of the mixture. The secondary polyols may be a polyether polyols, polyester polyols, polycaprolactone polyols, polycarbonates, acrylic polyols, polybutadiene polyols, polyalkylene triols, or a tetra-ols.

The adhesive exhibits at least 25 min of open time at 32°C and cures to high strength under ambient conditions. It can be used to adhere structural substrates such as reinforced plastics, metals, wood, and glass, as used in the construction, marine and automotive industries.