Professional Polymer Technology
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Many materials can be laminated and bonded, such as pap […]
Many materials can be laminated and bonded, such as paper, polyester film, polyethylene film, metal foil and fabric, and paper or film, so this uses a laminating adhesive.
Recently, as a packaging method, the composite flexible package has been developed remarkably because of the packaging strength, the protection of goods, the operational adaptability at the time of packaging, the publicity effect due to packaging, and the large and cheap supply of the film to reduce the packaging cost. As a laminated adhesive for such a film and a sheet, from the viewpoint of excellent adhesive property and cold resistance and heat resistance, and in view of a wide range of applications such as various materials such as plastic and metal foil , And a two-component polyurethane-based adhesive comprising a main agent having an active hydrogen group and a curing agent having an isocyanate group is generally used.
As such a laminated adhesive, there is disclosed a pressure-sensitive adhesive composition for composite lamination comprising a polyether polyol, a polyester polyol, a polyether urethane polyol and a polyester type One or two or more kinds of polyhydric alcohols and a isocyanate group-containing silane coupling agent and a polyisocyanate curing agent. However, although it is required to shorten the curing time of the pressure-sensitive adhesive layer in the laminating step, the reactivity of the curing agent for the laminating adhesive with the main agent is rarely taken into account in the past. That is, the curing reaction of the adhesive after coating is very slow, and therefore, a so-called curing promoting process called aging is required.
Specifically, it is necessary to deposit the laminated film in a holding chamber of 35 to 60C for about 3 to 5 days to perform aging, thereby curing the adhesive. In this case, the degree of curing of the adhesive is changed depending on the aging conditions. Therefore, the adhesive strength of the laminated film is affected, and in the case of insufficient aging, the curing of the adhesive is poor.