Patent GB-1169200-A (GB)
Title: Improvements in or relating to Pressure-Sensitive Adhesive Products
Inventor: MOLINE NORMAN LEE
IPC: C09J7/20
Filed: 1966-12-09
Abstract: 1,169,200. Pressure sensitive adhesive label. AVERY PRODUCTS CORP. 9 Dec., 1966 [20 Dec., 1965], No. 55151/66. Heading B5N. A pressure-sensitive adhesive product, e.g. a label, comprises a face layer 12, a layer of pressure-sensitive adhesive 13 adhered to one side of the face layer, the adhesive layer having dispersed and retained therein a large quantity of solvent for said adhesive, the amount of solvent being at least 10% by weight of the adhesive and solvent and being such that a surface to which the product is applied is wetted and such that the solvent evaporates on exposure to the atmosphere and yet insufficient to render the adhesive flowable laterally of the face layer, and a release liner 15 adhered to the side of the adhesive layer opposite from the face layer. The face layer 12 may include an anchor coating of a material which improves its bond to the adhesive 13, or may be impregnated with such material, and the liner 15 may include, as shown, a coating 16 which may render it readily releasable from the adhesive 13 and/or impervious to the solvent in the adhesive 13 or vapours thereof. The layer 12 may also be pervious or impervious. The layer 12 may be paper, woven or non-woven fabric, plastics film, or metal foil, or a laminate of any of these materials. The release liner 15 may be paper, fabric, plastics film, or a laminate of these materials. The adhesive may be an elastomer such as natural rubber, styrenebutadiene rubber, neoprene rubber, chlorosulfonated polyethylene, a polyester or polyether-urethane elastomer, butadiene-actylonitrile rubber, butyl rubber, an ethylene propylene co- or ter-polymer, stereoregulated isoprene or butadiene rubber, or combinations of these materials, or an acrylic polymer or copolymer or a vinyl ether polymer. The adhesive may include 10-80% by weight of solvent, preferably 20-50%, and preferably includes a high volatility solvent and a low volatility solvent. In one method of making the product the liner 15 is coated with the material 16 which is allowed to dry. The adhesive 13 including solvent(s) is flowed on to the coated liner and partially dried, i.e. the high volatility solvent is evaporated, the layer 12 is applied to the adhesive and then printed if desired before the layer 12 and adhesive 13 are die cut and the waste portion 18 stripped away to leave labels 10. In an alternative method the adhesive is first applied to the layer 12. In one particular embodiment the adhesive is a polyester resin, the high volatility solvent is acetone, or methyl ethyl ketone, or ethyl acetate, and the low volatility solvent is ethylene glycol monoethyl ether acetate, butyl carbitol, or diethylene glycol ethyl ether. In another example the release liner is silicone coated glassine paper, the adhesive is an acrylate ester copolymer dissolved in a mixture of methyl ethyl ketone, toluene, and methyl alcohol, and the face layer is a polished cotton and polyester film laminate. In a further example the adhesive is releasably adhered to the face layer 12 as well as to the liner 15 but more strongly adhered to the former. In use the liner 15 is stripped off and the exposed adhesive applied to a wood surface, the layer 12 is then removed and a metal surface contacted with the exposed adhesive surface.