polyurethane compositions with improved hydrolytic stability and good physical properties of resistance and methods for their preparation

摘要

1513915 Polyurethanes ATLANTIC RICHFIELD CO 3 July 1975 [10 July 1974] 28065/75 Heading C3R A urethane polymer having good hydrolytic stability is prepared by reacting at least one polyisocyanate with a polyhydroxyl component which comprises (a) at least one polyol selected from polyester polyols and esters of hydroxylated fatty acids and polyhydric alcohols, and (b) 5-40% wt. based on the total weight of reactants of at least one polyhydroxyl polymer of a 1,3-diene hydrocarbon of 4-12 carbon atoms which is unsubstituted or 2- and/or 3-substituted, said polymer having 1À8 to 3À0 predominantly primary, terminal, allylic hydroxyl groups per molecule and a number average molecular weight of 400 to 25,000, the relative amounts of polyisocyanate and total polyhydroxyl compounds being such as to provide an NCO to OH group ratio of 0À85 to 2À0 : 1. The polyisocyanate may have 2-6 NCO groups per molecule and is preferably an aromatic diisocyanate. Suitable dienes are 1, 3-butadiene, isoprene, chloroprene, 2-cyano- 1,3 - butadiene and 2,3 - dimethyl - 1,3 - butadiene. The hydroxylated 1,3-diene polymers may have viscosities of from 5-20,000 poises at 30‹ C. and may be a homo-polymer or a copolymer, e.g. of butadiene and another vinyl monomer, e.g. styrene. The polyester polyols generally have molecular weights of 550 to 4000 and OH numbers of 12 to 1100 and may be linear or branched. Suitable polyesters are derived from aliphatic or aromatic polycarboxylic acids with aliphatic or aromatic polyhydric alcohols. Component (a) may also be a polylactone or a diglyceride of OH-containing castor oil, tall oil, soya oil or linseed oil, ethylene glycol- or propylene glycolmonoricinoleate or mono - 12 - hydroxy - stearate, pentaerythritol tetraricinoleate, or the triglyceride of ricinoleic acid. The polyurethane reaction may be carried out by the one-shot or prepolymer methods in the presence or absence of an inert solvent and optionally in the presence of a catalyst. Optional additives include fillers, extenders, plasticizers, antioxidants and colorants. In the examples polyurethanes are prepared by the one-shot technique from (1) a hydroxylated polybutadiene of M.Wt. 2700, (2) diphenylmethane 4,41 diisocyanate or toluene diisocyanate, (3) either (a) trimethylolpropane, 1,4-butane diol and 2- poly(diethylene glycol adipate) diols of different molecular weights, or (b) 1,4-butane diol, a polycaprolactone triol and 2 polycaprolactone diols of different molecular weights, and (4) di(phenylmercuric) dodecenyl succinate as catalyst. The polyurethanes are cured by heating.