Patent GB-1255016-A (GB)
Title: Heat-reflective fabrics
IPC: C09J7/02
Filed: 1968-10-04
Abstract: 1,255,016. Heat reflective laminate. MINNESOTA MINING & MFG. CO. 4 Oct., 1968 [6 Oct., 1967], No. 47246/68. Heading B5N. [Also in Division B2] A heat-reflective sheet material for adhesive application to fabric to adapt the fabric for incorporation in a durable, heat-reflective, supple garment comprises a self-supporting base sheet and a continuous layer of partially overlapping heat-reflective flakes disposed flat against and adhered to one surface of the base sheet, the base sheet including (1) a flakebinding layer comprising elastomeric material and (2) a fabric-adhesive layer comprising an initially thermosoftening and flowable material which penetrates the fabric during application of the sheet material. The sheet material may also include a removable cover sheet over the layer of heat reflective flakes. The base sheet may consist of a single layer of elastomeric material comprising a heat-curable elastomeric material only partially advanced so that it will soften when the sheet material is applied to fabric. As shown in Fig. 1 the sheet material includes a thin base sheet 11 that includes an elastomeric flake-binding layer 12 and a fabricadhesive layer 13. Highly heat-reflective flakes 14 such as flakes of aluminium are adhered over the outside surface of the flake-binding layer 12. The base sheet is carried on a removable carrier sheet 16 and the metal layer is covered by a removable cover sheet 17. The flake-binding layer 12 may be separated from the fabric-adhesive layer 13 by a barrier layer. The sheet material is made by coating the layer 13 on a release paper that serves as the carrier sheet 16, coating the layer 12 over the layer 13, cascading flakes 14 on the surface of the layer 12, brushing to remove the excess flakes and orient the remaining flakes, passing the thus prepared assembly through nip rolls that further orient the flakes and finally coating a releasable film over the layer 15 of flakes 14. The layers may finally be heated to dry or cure them. To apply the sheet material to the fabric, the carrier sheet 16. is first removed and the outside surface of the layer 13 laid against the fabric and then with a vacuum drawn underneath the fabric the sheet material and the fabric are heated to 250 to 300‹ F. The material of the flake-binding layer may be a cross-linked or heat-cured material which is substantially infusible and insoluble after application to the base fabric, e.g. an epoxy resin. The fabricadhesive layer material should be at least initially thermo-softenable and flowable, preferably thermoplastic. In an alternative method, the elastomeric layer is attached by directly coating on to the fabric, and reflective flakes are then cascaded on the wet, coated continuous layer, oriented and the fabric then heated to cure the flake-binding layer. In Example (1) a fabric-adhesive layer is coated from a solution containing vinyl chloride-vinyl acetate resin and aluminium pigment on to silicone-treated release paper, and a flake-binding layer then coated over the first-coated layer using a solution containing diglycidyl ether of bisphenol A, tris(2,4,6-dimethyl amino methyl) phenol catalyst, poly(tetramethyleneoxide)amine, N(5- amino ethyl-gamma-amino propyl-trimethoxy silane) coupling agent, methyl siloxane oil flow agent, aluminium flake. The same aluminium flake included in the flake-binding layer is then cascaded on to the tacky surface of the flakebinding layer, excess of flake brushed off and the remaining flakes oriented by hand brushing. The assembly is then placed in a 200‹ F. oven and dried. A cover sheet is then coated over the layer flakes from a solution containing cellulose acetate resin, diethyl phthalate. A length of the resulting sheet material is laminated to a flameproof cotton twill fabric using a vacuum and at a temperature of 325‹ F. The cellulose acetate cover sheet is then stripped away. In the other Examples: the fabric-adhesive layer comprises in (2) thermoplastic polyester resin formed from terephthalic acid, ethylene glycol and neopentyl glycol, tri(dichloropropyl) phosphate flame retardant, in (3) a thermoplastic polyurethane elastomer and O,O-diethyl-n, n-bis(2-hydroxy ethyl) amino methyl phosphate flame retardant; the flake-binding layer comprises in (2) chlorosulphonated polyethylene, antimony trioxide flame retardant, curing agents, accelerators, diglycydyl ether bisphenol A, aluminium pigment, in (3) as in (2) with the exception that the aluminium pigment is replaced by copper flakes; and the heat-reflective flakes are in (2) aluminium, (3) copper. In Example- (4) the sheet material includes a single-layer base sheet coated on silicone-treated release paper using a solution containing chlorosulphonated polyethylene, flame retardant, curing agent, accelerators, diglycydyl ether of bisphenol. A, and aluminium pigment and aluminium flake is cascaded on to the coated layer, oriented and the assembly dried and heated to partially cure the single layer before application of a cellulose acetate cover sheet. The resulting material is applied to fabric as described in (1). In Example (5) a fabric woven from nylon monofilaments is soaked in a solution in acetone of N-perfluorooctane sulphonamide of diethylenetriamine, the fabric dried and the flake-binding solution of (1) coated thereon. Aluminium flake is then cascaded on to the surface of the coating, oriented and the assembly cured for 30 minutes at 250‹ F.