Patent GB-1438617-A (GB)
Title: Process and apparatus for the production of decorative articles from vinyl resin plastisols and products thus obtained
IPC: D06N3/00
Filed: 1974-05-01
Abstract: 1438617 Decorative coatings on vinyl resins SOLVAY & CIE 1 May 1974 [2 May 1973] 19089/74 Heading B2E Decorative layers of vinyl resin material are produced by applying to a substantially uniform layer of expandable vinyl resin plastisol, lengths of non-expandable vinyl resin plastisol in a decorative pattern and then heating the decorated layer to 120 to 210C whereby the expandable layer is expanded and the lengths of plastisol and the layer are integrated with each other. The expandable layer consists of a paste obtained by swelling particles of vinyl chloride homopolymer or copolymer with e.g. vinyl acetate or an acrylic ester, in a plasticiser (e.g. dioctyl phthalate and/or butylbenzyl phthalate) to form a paste. The plastisol contains a thermally-activatable blowing agent such as azodicarbonamide, and may also include stabilisers, diluents, fillers, pigments or dyestuffs, flameproofing agents, accelerators and surfaceactive agents. The layer is preferably applied on a reinforcing support eg. woven or knitted fabric, non-woven textile, paper or synthetic paper, which may either be embedded in the face to be decorated or applied to the back surface of the plastisol layer. Alternatively the layer may be formed on a temporary carrier (e.g. siliconised release paper, pre-gelled, decorated according to the inventive process and then the composite article removed from the carrier. In alternative embodiments, (a) the lengths of non-expandable plastisol are applied onto a temporary carrier, pre-gelled and then covered with a layer of the expandable plastisol, the whole then being heated to effect integration and expansion, and the formed article then being stripped from the carrier; (b) the lengths of non-expandable plastisol are applied to a pre-expanded layer of the expandable plastisol and then the product is covered by a second uniform layer of the expandable plastisol, followed by the subject process of heating for expansion and integration, to give a layered decorative product in which the decorative lengths show a surface effect through the second layer of expanded plastisol. The lengths of non-expandable plastisol may be of the same or a different colour from the 'base layer. They may have several crosssectional profiles, e.g. square, triangular or semi-circular, and may be applied longitudinally in rectilinear parallel stripes or in sinusoidal pattern. The non-expandable plastisol should have a suitable viscosity to allow for plastic application but not so low as to cause spreading out or deformation of the profile. Suitable viscosity is 15 to 200 poises as 25C. The expandable plastisol is preferable pregelled before their application, e.g. by moderate surf ice heating. The expandable plastisol may comprise two or more layers of different exandable vinyl resin plastisol. The lengths of non-expandable plastisol are preferable applied from a plurality of extruding nozzles onto a moving band of the expandable layer, immediately upstream of means for delimiting the lengths, such as a toothed blade with gaps of a profile corresponding to the desired profile for the lengths. If the pattern of lengths is to be sinusoidal, this may be effected by imparting periodic transverse reciprocating movement to the gapped blade.