Patent GB-820005-A (GB)
Title: Improvements in polyurethane elastomers and method of making the same
IPC: C08G18/67
Filed: 1957-04-25
Abstract: A method of making a synthetic elastomer comprises heating at a temperature of from 20 DEG  to 200 DEG  C. a mixture comprising (a) a material selected from polyesters, polyethers, polyesterethers and polyesteramides, (b) an organic diisocyanate, and (c) a substance possessing only one group reactive with diisocyanate and possessing additionally nonbenzenoid unsaturation and having the formula HXZ, where X is selected from O, NH, NQ and S (Q being an organic group inert towards isocyanate) and Z is an organic grouping containing not more than 20 carbon atoms which is inert towards isocyanate and contains nonbenzenoid unsaturation, the mol. ratio of said ingredients being (a) 1.0; (c) 0.03 to 1.0 and (b) 1.0 to 1.25 equivalents for each equivalent of isocyanate-reactive groups in the other ingredients.  The reaction mixture may also contain 0.03 to 3.5 mols. per mol. of (a) of a urea linkage former selected from the group consisting of diamines, water, aminoalcohols and aminophenols, or the reaction product of (a), (b) and (c) may be heated with the urea linkage former.  The unsaturated compound may contain as the group reactive with isocyanate, for example OH, NH, NH2, SH, COOH or CONH2 groups.  Such compounds contain also at least one ethylenic or acetylenic bond.  Examples are allyl alcohol, methallyl alcohol, methylvinyl carbinol, p-allyl benzyl alcohol, citronellol, 2-propyn-1-ol, geraniol, b -allyloxyethyl alcohol, methallyl - d  - hydroxy - pentanoate, ethylene glycol monocrotonate, 2-butene-1,4-diol monoacetate, o- or p-allyl phenol, allyl amine, diallyl amine, methallyl amine, N-methyl allylamine, methallyl mercaptan, methacrylic acid, monomethallyl succinate, ethyl maleate. The products may advantageously be cured or vulcanised by the method of Specification 820,004.  The vulcanizable mix may include carbon black or other fillers such as asbestos, blanc fixe, clay, iron oxide, lithopone, mica, silicious materials, titanium dioxide, whiting or flock.  As catalysts for the reaction of the diisocyanate and polyester there may be used cobalt naphthenate or diethylcyclohexyl amine.  Preferred polyester starting materials have hydroxyl number 22 to 225 and molecular weight 500 to 5000. Polyethylene-propylen adipate, polyethylene adipate-phthalate and polyneopentyl sebacate are mentioned.  As agents capable of forming urea linkages in the products there are mentioned aromatic and aliphatic diamines, aliphatic and aromatic aminohydroxy compounds, diamides, water. Glycols, mercapto-alcohols, di-acids, hydroxy-acids, trihydroxy compounds and tri-acidic compounds may also be present in the reaction mixture.  In examples: (1) a prepolymer from the reaction of polyethylenepropylene-adipate, diphenylmethane diisocyanate and methylvinyl carbinol is reacted with p,p1-diaminodiphenylmethane and cured with cumyl peroxide as curing agent; (2) in similar processes the monofunctional agent is variously methylvinyl carbinol, allylamine and 2-propyn-1-ol and diphenylmethane, hexamethylene, 2,4-toluene and p-phenylene diisocyanates are employed; (3) geraniol and methallyl alcohol respectively are the monofunctional organic compounds; (4) a process similar to that of (1) is varied by using no urea-linkage forming compound and also, respectively, b -aminoethanol, water, and p-aminophenol; (5) carbon black is used as compounding agent in a process similar to (2); (6) polytriethylene glycol adipate, polyethylene adipate phthalate and polytetramethylene glycol, respectively, are used as initial reactants; (7) the polyester used also contains unsaturation in the chain being polyethylene - propylene - 2 - butene - 1,4 - diol adipate; (8) a reaction product of methallyl alcohol and diphenyl methane diisocyanate is heated with ethylene propylene adipate and p,p1-diamino diphenyl methane and the polymer obtained is cured with dicumyl peroxide.  The products may be used in the manufacture of tyres, belts, textile processing, aprons, tubing, sheeting or laminated fabrics.