| 摘要 |
<p>Bonded metal cans with excellent resistance to hot water are made from a metal sheet coated with a primer coating of an epoxy-phenolic coating compsn., the seam in the side wall being bonded with a linear polyamide adhesive. The primer coating compsn. used comprises 50-95 wt.% of an epoxy resin with a number av. mol. wt. of 800-5500, made by condensing an epihalohydrin with bisphenol A; and 5-50 wt.% of a resol-type phenol formaldehyde resin with a number av. mol. wt. of 200-1000, made by reacting a mixed phenol consisting of 65-98 wt.% of a phenol of formula (I) (where R is a bridging gp. or a direct bond), and 2-35 wt.% of a monohydric phenol, with an aldehyde in the presence of a basic catalyst. Process allows cans to be made from tin-free steels (TFS) such as chromed steel sheet, which are difficult to solder. Using metals sheets primed with an epoxy-phenolic resin primer compsn. as described, bonded cans can be made using polyamide hot melt adhesives which have excellent resistance to hot water and resistance to deterioration on storage in contact with canned foods, drinks, fruit juices, etc.</p> |
