| 摘要 |
The appearance of textile and like materials including skins and furs, whether dyed or not, is improved by treating them with a blue-fluorescent compound which is a substituted dihydrocollidine of the general formula <FORM:0722791/IV (c)/1> in which R1 and R2 are carbalkoxy, carbaralkoxy, or N-phenyl-(or substituted phenyl)-carbamido groups and R3 is a methyl, ethyl or aryl group. The compounds may be employed as aqueous dispersions or they may be sufficiently soluble in water, particularly hot water, to be used in aqueous solution. They may be used alone or in conjunction with the normal hydrosulphite or peroxide baths when used for bleaching. When applied to dyed materials they improve the brightness of the colour. In examples, (1), (2) and (3) bleached wool yarn and woollen piece goods are treated with the diethyl ester of dihydrocollidine dicarboxylic acid in the presence of formic acid; (4) wool is treated, during or after bleaching with a hydrosulphite and in the presence of formic acid, with a solution of the whitening agent above; (5) wool is treated as in (4) after bleaching in a hydrogen peroxide bleach; (6) wool is dyed in a pastel shade with Alizarine Brilliant Blue B and aftertreated with the whitening agent above or the whitening agent is added to the dyebath; (7) dressed lambskin is bleached with a hydrosulphite bleach and then treated with the whitening agent above; (8) bleached rabbit skins or fur are treated with the whitening agent in presence of formic acid; (9) wool is treated with the whitening agent in the presence of formic acid; (10 to (13) nylon and cellulose acetate are similarly treated with or without the formic acid; and (14) cotton is treated with the whitening agent in the presence of Glaubers salt.ALSO:2,4,6 - Trimethyl - 3,5 - di - N - phenyl - carbamido - 1,4 - dihydropyridine is prepared by heating together acetaldehyde ammonia and acetoacetanilide in alcohol. Similarly, 2,4,6 - trimethyl - 3,5 - di(p - methoxy - N - phenyl - carbamido) - 1,4 - dihydropyridine is prepared from acetaldehyde ammonia and p-methoxy-acetoacetanilide. 2,4,6 - Trimethyl - 1,4 - di - hydropyridine - 3,5 - dicarboxylic acid methyl ethyl ester is prepared by condensing methyl acetoacetate with acetaldehyde to give ethylidene-acetoacetic methyl ester CH3CO.C(:CHCH3)COOCH3, which is then condensed with b -aminocrotonic ester. The b -aminocrotonic ester is made by condensing ethyl acetoacetate with aqueous ammonia. |
