GB702206A - Improvements in or relating to the production of dialdehydes and derivatives thereof - Google Patents

Abstract

Dialdehydes or their derivatives, prepared by reacting a cyclic acetal of the type formed by condensation of an olefinic aldehyde with a compound having at least two hydroxyl groups attached to different carbon atoms of an aliphatic carbon chain with CO and H2 under Oxo synthetic conditions (see Group IV (b)), are used as plasticizers, intermediates for polymer production, and for after-treatment of plastics, in the form of extruded and moulded products and fibres made from natural polymers such as proteins and cellulose. Thus, fibres of proteins such as casein, peanut or soya bean globulins are treated with succindialdehyde instead of formaldehyde. Succindialdehyde with an alkylene or arylene diamine gives an unsaturated linear polymer yielding a polymeric mine on hydrogenation.ALSO:Dialdehydes or derivatives thereof are produced by reacting a cyclic acetal, of the type formed by condensation of an olefinic aldehyde with a compound having at least two hydroxyl groups attached to different carbon atoms of an aliphatic carbon chain, with CO and H2 under Oxo synthesis conditions. Preferred cyclic acetals are those formed by condensation of the olefinic aldehyde with diols having the hydroxyl groups attached to adjacent carbons or carbons separated by one carbon atom. The diols may contain substituted or unsubstituted cycloaliphatic or aryl radicals. The olefinic aldehyde may be aliphatic, preferably of 3-7 carbon atoms, e.g. acrolein, methacrolein, crotonaldehyde, and ethylpropylacrolein, or cyclic, e.g. tetrahydrobenzaldehyde. The diol employed may be a 1, 2 or 1, 3 glycol, e.g. ethylene glycol, pinacol, and 1, 3-butylene glycol. The Oxo reaction may be effected at 120-200 DEG C. and 50-300 ats. or more with a cobalt catalyst, preferably a carbonyl or carbonyl hydride in liquid or p gaseous phase, as described in Specifications 702,191, 702,192, 702,195, 702,196, 702,197, 702,201, 702,203, 702,204, 702,221 and 702,222. Solvents may be present; and solid cobalt may be present in starting up or deposited by carbonyl decomposition. Unreacted aldehyde may be separated from the product by distillation and recycled, and the mono-acetal of the dialdehyde recovered. This may be hydrolysed with mineral acid to yield the dialdehyde. The dialdehydes or their diacetals are of use as plasticizers or intermediates. Succindialdehyde obtained from the acetal of acrolein reacts with diamines to give linear polymers which on hydrogenation give linear polymeric imines. Protein products such as fibres of casein, peanut or soya bean globulins may also be treated with succindialdehyde to increase their water resistance. Examples describe the production of acetals of acrolein and 2, 3 or 1, 3-butylene glycol or glycerol, of ethylpropylacrolein and 1, 3-butylene glycol, crotonaldehyde and 1, 3-butylene glycol, and D 3-tetrahydrobenzaldehyde and 1, 3-butylene glycol or ethylene glycol, and the reaction of these acetals with water gas, in batch or continuous operation, at temperatures from 136 to 161 DEG C., pressures from 2,500 to 3,000 p.s.i., with Co2(CO)8 as catalyst dissolved in the feed.