Patent GB-728545-A (GB)
Title: Improvements in or relating to marking structure and method of making the same
Inventor: BREWSTER ERNEST BILLINGS
IPC: G09F3/02
Filed: 1953-03-11
Abstract: 728,545. Labels manifolding units. ADHESIVE TAPES, Ltd. March 11, 1953, No. 6661/53. Classes 16 and 73. [Also in Group XVI] A label comprises a marking structure having a layer of transparent flexible material permanently secured in fixed relation to an underlying pressure-sensitive marking layer in position to be affected by pressure of writing strokes applied to the upper surface of the transparent layer, the marking layer normally obscuring any layer beneath it and being changed by the pressure of writing strokes to make an underlying layer visible through the marking layer along the lines of the pressure strokes. As shown in Fig. 2 the marking structure is made in a roll of flexible tape to be cut off as required and is made in two units which are then combined to form a single structure. The top unit comprises a transparent sheet 21 coated with a release coating 23 which permits easy release of the sheet 21 from the pressure sensitive adhesive 37 on the bottom of the tape when unrolled and a pressure sensitive marking layer 27 of crystalline waxy material, and the base unit comprises a base sheet 31, e.g. of paper, of a dark colour coated on top with a release coating 33 and underneath with a primer layer 35 for the adhesive layer 37. Both units are made up into rolls separately and are then unrolled to combine them together under pressure by means of adhesive strips 39 applied to the marginal edges of the base strip 31 over the release coating 33, the combined units being made into rolls or cut to short lengths and piled successively to make a pad. Many examples are given of suitable materials for the sheets 21 and 31. If the material selected for the sheet 31 is not of contrasting colour with the layer 27, the necessary colour contrast may be produced by a coloured coating on the top surface of the sheet 31 or on the bottom surface of the layer 27 or by using colouring in the release layer 33, in the bottom adhesive layer 37 or in the adhesive 39 where it extends beneath the layer 27. The adhesive 39 may be "hot melt" adhesive, or heat sealing material or if the sheets 21 and 31 are of similar composition affected by a solvent, they may be solvent sealed. The adhesive layer 39 and/or the layer 27 may extend over the full width of the tape. In a modification shown in Fig. 6 the base sheet 31 is omitted and the structure comprises a release coating 23d, a transparent sheet 21d, a primer 35d or an adhesive coating 37d which projects beyond the marking layer 27d of waxy material, so that the tape may be applied to a box or sheet of paper which is itself of dark colour contrasting with that of the layer 27d. Additionally a layer 41 may be provided which may be merely a protective sheet for the layer 27d, or may be a colour contrasting layer or coating. In a further modification the arrangement shown in Fig. 6 forms a top unit which is combined with the bottom unit shown in Fig. 2. In those forms of the structure made from two units the marking layer of waxy material may be placed on the upper face of the lower unit before securing the units together. Fig. 8 shows marking tapes 83 temporarily secured to a carrier sheet 81 for use with a typewriter, the tapes being subsequently stripped off the carrier sheet and affixed to the articles desired to be marked. In addition a "book" of small carrier sheets with marking tapes thereon of similar form to a "book" of paper matches may be formed. U.S.A. Specification 1,783,442 is referred to.