Patent GB-787592-A (GB)
Title: Sheet structures, polymeric materials for use in the production thereof, and a process for producing said sheet structures
IPC: C08G18/12
Filed: 1955-02-23
Abstract: Insoluble, cross-linked foils and coatings are prepared from a composition comprising as one component a soluble branched isocyanate-modified polyhydroxy compound having not more than one branch for every 5000 units of molecular weight and a specific viscosity of between 0.03 and 0.5, and as another component a polyisocyanate or a compound which reacts as a polyisocyanate when heated, by reacting the two components, heating if necessary. The branched compound may be made by reacting a diisocyanate with a slightly branched polyester or polyether, or by reacting a linear polyester or polyether with a diisocyanate and a trifunctional compound which may be a trihydric alcohol or a triisocyanate.  The reaction may be catalysed by basic compounds or soluble metal compounds.  The composition may include solvents, fillers, dyes, plasticizers and other high polymers, e.g. cellulose derivatives. The inclusion of fatty acid salts such as the tin, zinc, titanium or zirconium salt of a C6 to C10 fatty acid in a composition for coatings prevents the free surface of the coated material from sticking to the coated surface.  The composition may be continuously mixed and dispersed, particularly when using highly reactive polyisocyanates.  In examples: (1) 4000 parts of a polyester from 10 mols. adipic acid, 8.8 mols. ethylene glycol and 1.9 mols. diethylene glycol of molecular weight 2340 are reacted with 22.9 parts trimethylol propane and 300 parts hexamethylene diisocyanate to give a polymer of specific viscosity 0.207.  100 parts of a 30 per cent solution of this polymer in ethyl acetate are mixed with 5 parts of a 75 per cent solution of a polyisocyanate from 1 mol. hexanetriol and 3 mols. tolylene diisocyanate and with 0.5 parts of an accelerator from 1 mol. N-methyl diethanolamine and 2 mols. phenyl isocyanate and the mixture applied to a glass support for 24 hours at room temperature to give an elastic insoluble film.  (2) Similar to (1) using an aliphatic polyisocyanate and ferric acetonyl acetonate as accelerator.  (3) Similar to (1) but using a mixture of different polyesters and using different polyisocyanates.  The composition was used to make foils and fabric coatings.  (4) Similar to (1) but using a different polyester and a different polyisocyanate in the final stage, the composition including china clay, titanium dioxide and iron oxide as fillers.  The composition was applied to a fabric to give a leather-like coating.  (5) 100 parts of a polyether of molecular weight 4000 from ethylene oxide and trimethylpropane and 500 parts of a polyether from ethylene oxide and ethylene glycol of molecular weight 2000 are reacted with 52.3 parts hexamethylene diisocyanate in the presence of acetyl chloride to give a polymer of specific viscosity 0.065.  100 parts of a 50 per cent solution of this polymer are mixed with 10 parts of a 75 per cent solution of a polyisocyanate from trimethylol propane and tolylene diisocyanate and used to impregnate a polyamide fabric, the coating being cured at 80-100 DEG  C. for 10 hours.  A repetition of the impregnation gives a completely waterproof product. Specification 745,960 is referred to.