Wrinkle free pressure sensitive adhesive paper laminates - by laminating a face paper coated with water dispersed adhesive with a release paper and conditioning to equilibrate the moisture content

摘要

Pressure sensitive adhesive coated laminates with a release film over the adhesive are made by (a) providing a web of paper face stock; (b) providing a web of moisture sensitive or absorptive release paper coated with a release material; (c) coating either the web (a) or the previously coated side of web (b) with a water-dispersed pressure sensitive adhesive; (d) before drying, joining the webs (a) and (b) together with the wet adhesive between them; (e) passing the joined webs through a pressure nip to form a laminate; (f) drying the laminate to a relative humidity of 30-60% (Cambridge Moisture Indicator test) to allow for moisture equilibration between the webs; (g) winding the laminate onto a roll; and (h) conditioning the laminate for a sufficient time prior to further processing to allow for additional moisture equilibration between the webs. Compared with prior art processes for making pressure sensitive adhesive laminates from water-based adhesive dispersions, the present process gives adhesive layers with a smooth uniform surface and the laminate is flat and wrinkle free. The prod. is useful e.g. in the prodn. of self adhesive labels.