Solvent-borne adhesive lamination

The market for polyurethane thermoplastic adhesives is small, but growing. TPU s are used to produce some solvent-borne adhesives and also are used in laminating textiles and films for labels and emblems. In addition, they are being considered as an alternative to solvent-borne adhesives in the shoe market. 

Water-borne adhesives are preferred because of restrictions on the use of solvents. Low viscosity prepolymers are emulsified in water, followed by chain extension with water-soluble glycols or diamines. As cross-linker PMDI can be used, which has a shelf life of 5 to 6 h in water. Water-borne polyurethane coatings are used for vacuum forming of PVC sheeting to ABS shells in automotive interior door panels, for the lamination of ABS/PVC film to treated polypropylene foam for use in automotive instmment panels, as metal primers for steering wheels, in flexible packaging lamination, as shoe sole adhesive, and as tie coats for polyurethane-coated fabrics. PMDI is also used as a binder for reconstituted wood products and as a foundry core binder. 

Solvent-borne CR adhesives allow almost any two substrates to stick together. The adhesives are extensively used in bonding high-pressure plastic laminates, automotive adhesives, adhesives for construction and shoe adhesives. 

High-pressure laminates. Solvent-borne CR adhesives are used for bonding foams to wood or fabric, and for bonding metal, fibreglass and plastics. 

Solvent-borne urethanes are still widely used to bond leather and athletic shoes. The OEM automotive market uses some solvent-bome urethanes together with chlorosulfonated polyethylene as a primer. Some urethane solvent-bome packaging adhesives are used for cap liners and for paper and foil lamination. Some textile laminating applications are still based on solvent-bome urethanes. 

The increasing amount of research in waterborne systems should some day overcome technological difficulties. Howeverr the change-over from some solvent-borne to waterborne systems has presented difficulties (107), for exampler poor coating quality, excessive foam, insufficient water resistance, and even some corrosion and clean-up problems. Despite the problems, some waterborne systems have already been adopted for the manufacture of PSA s, contact adhesives, laminating adhesives, and wood adhesives. However, few applications of the waterborne systems as structural adhesives, especially as aerospace structural adhesives have been found. 

Petaflex, Laminating adhesives, solvent-borne. National Starch and Chemical Co. 

One-component water-borne polyurethane systems can be derived from polyurethane dispersions or blocked polyisocyanates (refer to Section 3.2.1). Blocked isocyanates are added to the co-reactant resins providing one-component systems with excellent shelf life. This type of adhesives is principally used for non-porous materials and the bonding of unlike metals such as aluminium to steel, and stainless steel to mild steel. They are also usefiil in bonding some of the high pressure laminates such as those based on phenoUcs and melamine [39]. Systems based on water-borne blocked polyisocyanate crosslinkers and suitable waterborne polymers approach the performance levels previously obtained only by solvent-borne systems [16]. 

Uses Solvent for paints, inks, cleaners, epoxy laminates, agric., adhesives, floor polish, oil field, mining, and electronic chems. solvent, coupling agenb welling agent, soil penetrant in cleaners coalescent for architectural water-borne coatings HAPs-free Manuf/Distrib. Aldrich Ashland G.J. Chem. Spectmm Quality Prods. Trade Names Arcosolv DPMA Dowanol DPMA... 

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