Patent GB-945031-A (GB)
Title: Process for providing concrete surfaces with impermeable coatings that are resistantto the action of chemical substances and heat
IPC: B32B27/00
Filed: 1959-12-28
Abstract: Compositions for coating concrete comprise a phenol formaldehyde resin with an inert filling mixture of coke and synthetic graphite; a mixture of phenol formaldehyde resin, sand and a hardener; an epoxide resin having an epoxy equivalent of 195 dissolved in xylene, diethylene triamine, asbestos fibres and quartz sand; a mixture of a resin obtained by the condensation of furfuryl alcohol with sulphuric acid paratoluene sulphonic acid as hardener and coke; a mixture of an unsaturated polyester dissolved in styrene containing free hydroxyl groups as terminal groups and an unsaturated polyester dissolved in styrene whose free hydroxyl groups were modified with an excess of diisocyanates, benzoyl peroxide, dibutyl phthalate and powdered quartz.  Other suitable filling materials include barium sulphate and titanium dioxide.ALSO:A process for providing a concrete surface with an impermeable resinous coating that is resistant to the action of chemical substances and heat comprises providing the surface with (1) two or more layers of an adhesive resin, each layer except the last layer after having been applied being hardened thermally and/or catalytically by means of a catalyst that does not attack the concrete surface and then (2) an inert sharp-edged filling material which is applied to the last layer of adhesive resin before the latter has hardened and while it is still moist and sticky, the last layer of adhesive resin being hardened after the application of the filling material or after the application of the final layer; and then (3) a final layer which is thicker than the combined thickness of the adhesive resin layers which consists of an inert filler and a phenol formaldehyde resin and/or a furan resin and/or an unsaturated polyester resin modified with isocyanate and/or a liquid epoxy resin and which is hardened after its application, the hardening of the final layer being effected together with the last layer of adhesive resin if the latter has not yet been hardened; the adhesive resin being one that is capable of firmly adhering to concrete, i.e., whose adhesiveness on concrete is at least equal to the tensile strength of the concrete and which can be hardened by the action of heat and/or a catalyst which does not react with the components of the concrete; the resin being selected from the group consisting of (a) unsaturated polyester resins, (b) polyester resins modified with isocyanate, (c) commercial combinations of polyester and isocyanate, and (d) epoxy resins.  In examples the inner surfaces of concrete tubes are coated by brushing or spraying with solutions of resins and allowed to harden; further resin is then applied and quartz sand is strewn thereover; and then a final resin layer containing sand is applied. The mixture is uniformly distributed on the surface of the tube by rotating the tube until the resin has hardened.  Compositions which may be used include a phenol formaldehyde resin with an inert filling mixture of coke and synthetic graphite; a mixture of phenol formaldehyde resin, sand and a hardener; an epoxide resin having an epoxy equivalent of 195 dissolved in xylene, diethyleen triamine, asbestos fibres and quartz sand; a mixture of a resin obtained by the condensation of furfuryl alcohol with sulphuric acid, paratoluene sulphonic acid as hardener and coke; a mixture of an unsaturated polyester dissolved in styrene containing free hydroxyl groups as terminal groups and an unsaturated polyester dissolved in styrene whose free hydroxyl groups were modified with an excess of diisocyanates, benzoyl peroxide, dibutyl phthalate and powdered quartz.  Other suitable filling materials include barium sulphate and titanium dioxide.