| 摘要 |
A non-corrosive water-based lamination adhesive for carrying metallic particles is provided. The lamination adhesive is combined with pigments, preferably metallic particles, to form a lamination ink for printing on plastic cards or overlays. The adhesive comprises about 1-60 % solids of alkali-soluble acrylic resins, about 0-95 % solids low Tg polyvinyl chloride copolymers, said low Tg copolymers having a Tg in a range of between about 0-49 DEG C, about 0-95 % solids high Tg polyvinyl chloride copolymers, said high Tg copolymers having a Tg in a range of between about 50-100 DEG C, and about 25-85 % by weight water. The adhesive is an aqueous emulsion having a plurality of phases, including an aqueous phase and a solid phase. The alkali-soluble acrylic resins are in solution in the aqueous phase and the high and low Tg copolymers are in the solid phase. At least about 30 % of the total solids of the adhesive are either high or low Tg polyvinyl chloride copolymers. Preferably, the lamination adhesive of the present invention further comprises an amount of an anion scavenger effective to sequester chloride anions released into the adhesive during aging thereof so that the color of the adhesive has substantial thermal stability. The scavenger preferably includes about 1-50 % solids of epoxy resins wherein the epoxy resins are in an epoxy phase of the emulsion. In a preferred embodiment, the adhesive is combined with about 1-50 % solids of metallic particles to form a lamination ink. |
