Patent GB-461352-A (GB)
Title: Manufacture of condensation products and of lacquers and plastic masses therefrom
IPC: C08G12/22
Filed: 1935-07-11
Abstract: Oily to resinous condensation products are prepared by causing an aldehyde to act upon an ester of a carbamic acid and an alcohol containing more than two carbon atoms in the presence of a compound of acid reaction.  Aliphatic esters, e.g. the propyl, butyl, isobutyl, amyl, hexyl, heptyl, octyl, or isooctyl esters, hydroaromatic esters, e.g. cyclohexyl, methyl-cyclohexyl, and iso-bornyl, aralkyl, e.g. benzyl, aromatic, e.g. phenyl and cresyl, or esters of glycol mono-methyl or -ethyl ether or glycerine-acetaldehyde-acetal may be used.  The carbamic acid may be substituted at the nitrogen atom by alkyl or aryl radicals, e.g. methyl, ethyl, propyl, phenyl, or cresyl.  Formaldehyde or acetaldehyde or substances splitting off these aldehydes, e.g. their acetals, may be used.  Acids specified are hydrochloric, phosphoric, or boric, acid salts such as zinc chloride, potassium bisulphate, or acid sodium phosphate, or organic acids, e.g. lactic, oxalic, crotonic, trichloracetic, glycollic, or mono-ethyl oxalate.  The formic acid contained in commercial formaldehyde suffices, with prolonged heating.  Generally, a mixture of the carbamic ester with aqueous formaldehyde is heated to dissolve the carbamic ester, the acid is added, after the ensuing spontaneous reaction the mixture is heated, the product separated and washed, and, if desired, further heated under reduced pressure.  The products are soluble in alcohols, e.g. methyl, ethyl propyl, and butyl, aromatic hydrocarbons, e.g. benzene, toluene, and xylene and chlorinated hydrocarbons, and esters, e.g. methyl, ethyl, propyl, butyl, or benzyl acetate; those derived from higher aliphatic and aromatic esters dissolve in benzine and paraffin oil.  They may be used for lacquers, artificial leather, and plastics, e.g. together with nitrocellulose, cellulose esters or ethers, natural or synthetic resins such as colophony, copal, dammar, shellac, condensation products of colophony with maleic anhydride or phenol-formaldehyde resins, maleic acid-colophony-glycerin condensation products, cyclohexanol resins, glycerol-phthalate or glycerol-phthalate-fatty acid resins, phenol- or alkylphenol-aldehyde resins, novolaks or resols.  The oily products can replace the oil, e.g. castor oil, used in making artificial leather in conjunction with nitrocellulose &c.  In examples: (1) isobutyl carbamate is dissolved, by heating, in aqueous formaldehyde, and concentrated hydrochloric acid is added.  After the reaction, the mixture is refluxed, and after cooling the resin is separated, washed free from acid, and heated under reduced pressure; (2) a resin is prepared as in example (1) from cyclohexyl carbamate and formaldehyde with the aid of lactic acid; (3) a mixture of hexyl and heptyl urethanes is heated with aqueous formaldehyde, glycollic acid added when boiling, and the mixture boiled for 3 hours, the oily product is separated, washed, and heated under reduced pressure; (4) and (5) oily products are obtained as in example (3) from the carbamic ester of glycol mono-methyl ether, formaldehyde, and zinc chloride, and from the carbamic ester of glycerin-acetaldehyde acetal, formaldehyde, and mono-ethyl oxalate; (6) phenyl carbamate, aqueous formaldehyde, and hydrochloric acid are boiled under reflux to produce a resin which becomes insoluble on heating; (7) isobornyl carbamate and formaldehyde solution are heated while stirring and adding primary sodium orthophosphate, and the resulting resin heated; (8) and (9) an oil and a resin are made by adding hydrochloric acid to a heated mixture of 2-ethyl-n-hexanol and formaldehyde solution, and by adding potassium bisulphate to a heated mixture of benzyl urethane and formaldehyde solution, the mix being refluxed in both cases; (10) a condensation product from n-butyl urethane and formaldehyde prepared as in example (1) is mixed with a solvent naphtha solution of octylphenol aldehyde resin to produce a lacquer; (11) the product of example (1) is mixed with a solution of collodion cotton in butyl acetate, toluene, xylene, alcohol, and ethyl acetate, and pigmented with zinc oxide and titanium white to form a lacquer; (12) the product of example (3) is dissolved with nitrocellulose film scrap and tricresyl phosphate in alcohol and ethyl acetate and pigmented with carbon black; textile fabrics are coated with the paste to form artificial leather; (13) the product of example (4) is made with cellulose acetate and benzene-alcohol into a plastic material.  The Provisional Specification describes also the production of resins from carbamic esters of polyhydric alcohols, states that the oily or resinous products are useful as adhesives for uniting cellulose derivatives or polymeric materials to one another or to metal or glass, and describes the production of an oil from n-propyl carbamate, formaldehyde, and hydrochloric acid.  The oil is dissolved with collodion wool in alcohol and ethyl acetate, pigmented with zinc white and titanium white, and the paste spread on a woven fabric to provide an artificial leather, or may be used with cellulose acetate to form a plastic composition.  An oil may also be produced from isobutyl carbamate and aqueous formaldehyde with the aid of phosphoric acid, and used with collodion wool to produce a plastic composition.