Patent GB-801400-A (GB)
Title: Method of coating surfaces such as hulls of boats and ships with cold-curing resin-containing sheets
Inventor: ROBERTSON JAMES IAN
IPC: B29C63/48
Filed: 1955-10-24
Abstract: 801,400. Omamenting. CAMPER & NICHOLSONS, Ltd. Oct. 22, 1956 [Oct. 24, 1955: Dec. 8, 1955], Nos. 30391/55 and 35304/55. Class 93 [Also in Groups VIII and XXXIII] Surfaces, .e.g. the inner and outer surfaces of the hulls of boats or ships, are covered by means of a deformable sheet, consisting of fibrous reinforcing material and a partly cured cold-curing synthetic resin composition, which is subjected to temporary inhibition of the curing process of the resin by refrigeration e.g. at -15‹ to -20‹C., and is subsequently applied to the surface to be covered, a cold-curing synthetic resin composition being interposed as adhesive between the partially cured sheet and the said surface, and the resin allowed to cure completely, at ambient temperature or under artificial heating. The cold-curing resin may be an unsaturated polyester resin (particularly for use on wood), or an epoxy resin (particularly for use on metals) and may contain known catalysts and accelerators. The reinforcing material may be glass fibre which may be used in sheet form. A number of the sheets may be stored together in the same refrigerator, but must be spaced apart, e.g. by means of metal plates. The deformable, partly cured sheet may be produced by applying a layer of uncured resin composition to a backing of material (e.g. regenerated cellulose) incompatible with (i.e. non-adherent to) the cured resin, impregnating a sheet of fibrous reinforcing material with the composition by placing or pressing said fibrous sheet upon said layer and allowing curing to proceed until the product is self-supporting. Artificial heat may be used if necessary. The backing material may be tensioned over a base of soft resilient material (e.g. sponge rubber) to produce a smooth surface for the application of the resin composition. The backing material may be retained as an external covering until after complete curing of the resin and then stripped off. When the process is employed to apply successive coatings comprising deformable sheets, each intermediate regenerated cellulose support must be removed and the surfaces so exposed lightly sanded to form a key before the next sheet is applied. The deformable sheet may be conveyed from its place of manufacture to its place of use in a heat-insulated container, and there placed in a second refrigerator. The sheet when taken from the refrigerator is stiff but soon becomes flexible. It may be tailored to fit surfaces of complex curvature and the sheets may butt or overlap, or gaps can be filled in with tailored strips and resin adhesive. When it is important that no fibres of the glass shall penetrate the surface of the resin and be apparent on the exterior of the cured sheet, i.e. that surface of the cured sheet originally in contact with the regenerated cellulose sheet, a thin layer of resin alone is first applied to the regenerated cellulose sheet and allowed to gel and then further resin and glass-fibre reinforcement applied in the usual way. In this case, the outer surface of the cured sheet consists of resin only. According to the first Provisional Specification, the reinforcement may be of asbestos or textile fibres, and the synthetic resin may be a phenolic resin or a furane resin. Unimpregnated sheets of glass matt or woven glass fibres may be impregnated with resin after application to the surface to be covered. Sheets impregnated before application may be uncured, and may be applied to the surface without prior refrigeration. Heat for curing the resin may be applied by means of electric lamps, infrared lamps, infra-red heat, steam or hot air. The sheets may be attached in position by means of pins or clips in place of or in addition to the adhesive layer. According to the second Provisional Specification, long lengths of impregnated material may be stored at low temperature by having the material folded backwards and forwards with a metal sheet between each fold, and storage may be at 0‹C.