Patent GB-1059139-A (GB)
Title: Improvements in or relating to adhesive sheet materials
IPC: C09J7/50
Filed: 1963-11-18
Abstract: An adhesive sheet material has a film backing that comprises a saturated polyester and a layer of adhesive on at least one surface of the backing characterized by an intervening primer layer of a homogeneous blend of 15 to 90 parts by weight of soluble halogenated vinyl polymer and correspondingly 85 to 10 parts by weight of soluble saturated polyester.  The film backing may be a biaxially oriented polyethylene terephthalate film.  The homegeneous blend may contain up to 60 per cent by weight of polymerized ethylene terephthalate. The adhesive may be pressure sensitive.  The homogeneous primer layer may consist essentially of 25 to 85% by weight of soluble halogenated vinyl polymer, e.g. a copolymer of vinyl chloride and vinylidene chloride, or vinyl chloride, vinyl acetate and vinyl alcohol, and 75 to 15% by weight of a soluble copolyester; the copolyester having an inherent viscosity (defined) of at least 0.3 and being made up of 1/3 to 2/3 by weight of ethylene terephthalate units and 2/3 to 1/3 by weight of ethylene isophthalate units arranged at random in the polymer chain, and the adhesive may be a polar normally tacky and pressure sensitive adhesive.  The film backing may be uniformly coated on one surface with a thin adherent homogeneous pigment-opacified polymer layer consisting essentially of 15 to 90% by weight of soluble halogenated vinyl polymer and 85 to 10% by weight of copolyester, e.g. a soluble ethylene terephthalate-ethylene isophthalate copolyester having an inherent viscosity of at least 0.3, and containing up to 60% by weight of polymerized ethylene isophthalate, a normally tacky and pressure sensitive acrylate adhesive is firmly adhered thereto, and a pigment-opacified printable coating composition comprising a second copolyester similar in composition to the first copolyester is adhered to the other surface of the film backing thereby to provide a decorative adhesive label which can be firmly adhered to a metallic surface.  The intervening opaque homogeneous primer layer may contain approximately equal parts by weight of finely divided titanium dioxide, soluble chlorinated vinyl polymer and soluble copolyester, the copolyester having an inherent viscosity of at least 0.3 and containing substantially equal numbers of ethylene terephthalate and ethylene isophthalate units, and the film backing having on its other side an opaque homogeneous top layer comprising finely divided titanium dioxide uniformly dispersed in a soluble ethylene terephthalate-ethylene isophthalate copolyester, and decorative markings applied thereto.  The adhesive sheet material may be transparent and pressure sensitive and has a non-adhesive surface that may be readily silk screen-printed with acrylic process pastes to provide a weather resistant translucent insignia, which sheet material can be adhered to, and comprising a biaxially oriented polyethylene terephthalate film backing having firmly bonded over each surface a transparent homogeneous layer containing approximately equal parts by weight of soluble chlorinated vinyl polymer and soluble copolyester, the copolyester containing substantially equal numbers of ethylene terephthalate and ethylene isophthalate units, the film backing having a clear normally tacky and pressure-sensitive adhesive firmly adhered to one of the layers, and the film backing having, at least at the surface opposite to the surface over which the adhesive is adhered, an ultraviolet light absorbent material.  The adhesive may contain copolymers of acrylic acid esters and acrylic acid, methacrylic acid, itaconic acid, acrylamide or methacrylamide, a phenol-formaldehyde modified acrylates or phenol-formaldehyde modified Buna-N (Trade Mark).  The coatings may be applied by knife coating or by transfer from a polyethylene or siloxane coated paper.