GB1509108A - Covering for sports-ground surfaces - Google Patents

Abstract

1509108 Sports ground surfaces M CEINTREY 25 Nov 1976 [27 Nov 1975] 49146/76 Heading A6D [Also in Division C3] A resilient covering for sports surfaces e.g. athletic race tracks or gymnasiums or surfaces for tennis, volley - ball or basket - ball comprises a powder of resilient material having a particle size of 0.5 - 10mm and a binder said bonder being present in an amount of from 15-85% wt. with respect to the total weight of powder and binder, and having been obtained by mixing just before use (A) a prepolymer of a polyurethane having at least 2 terminal NCO groups, said terminal groups being blocked by a phenol with (B) a liquid polyamine. The preferred prepolymer (A) is linear and comprises chains of polyoxypropyilene or polyoxybutylene or copolymers thereof with polyoxyethylene having a M wt. of 1200 - 2500, terminated by a diisocyanate, preferably tolylene dusocyanate, blocked with a phenol e.g. phenol itself, a cresol or tert - butyl phenol. The powdered resilient material may be rubber powder, cork scrap or a polyurethane or a terpolymer elastomer, such as EPDM, in the form of a powder. The polyamine (B) may be an aliphatic diamine, e.g. trimethylhexamethylene diamine, a cycloaliphatic diamine, e.g. isophorone diamine, (4 - aminocyclohexyl) methyl - 4 - cyclohexylamine a heterocyclic amine e.g. aminoethylpiperazine, or an aromatic diaimine. The binder may contain as optional additives:- plasticizers e.g. anthracene oil, dioxtylphthalate or -adipate, and aromatic plasticizers from petroleum oil; organic solvents and colouring agents. A permeable covering is obtained when the binder is employed in an amount of 15-35% of the total weight of the powder and binder, and an impermeable covering is obtained when the binder is employed in an amount of 50- 85% on .the same basis. In the Examples permeable and impermeable resilient coverings are prepared from compositions comprising either EPDM rubber particles or rubber particles obtained by grinding old tyres, and a binder comprising a liquid prepolymer obtained by reacting tolylene diisocyanate with either poly (1, 4 - oxybutylene) glycol or polypropylene glycol, naphtha solvent, phenol, dibutyltindilaurate, red iron oxide, a siliceous filler, optionally dioctyl adipate, and either (4 - aminocyclohexyl) methyl - 4 - cyclo hexylamine or aminoethyl piperazine.