Process for fixing pigments on fiber materials and sheetlike structures
AssigneeHoechst Aktiengesellschaft
InventorsGerhard Pfeiffer, Erhard Doschke
Life of this patent
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Abstract
Deposit buildup on pad rolls in pigment dyeings and the filling up of engravings and screens in pigment printing are frequent problems in practice which in certain circumstances cause appreciable expenses (cleaning costs, stoppages). More or less all the binder systems in aqueous dispersion which are at present customary in practice tend to build up deposits and/or fill up holes. It has now been found, according to the invention, that the stated disadvantages can be avoided by using for the above purpose water-soluble 2-component binder systems and otherwise producing pigment dyeings in conventional manner.
Claims8
In a process for fixing pigments on fiber materials and sheet-like structures by means of curable synthetic resins or synthetic resin precursors which are cured by cross-linking at elevated temperatures in the presence of an acid or a compound which acts as an acid under the reaction conditions to form a water-insoluble film in order to adhere to the applied pigment on the surface of the substrate, the improvement which comprises:
- applying to the substrate a padding liquor or print paste which, in addition to pigment, contains a pigment-binder system comprising:
- (I) the aqueous solution of an essentially non-cross-linked polyester resin obtained by polycondensation of aliphatic or aromatic dibasic or polybasic carboxylic acids with polyetherdiols to the semi-ester thereof and subsequent reaction with aliphatic or aromatic epoxy resins under continued esterification of the semi-ester up to an acid number of less than 5 to yield a polycondensate still having available free hydroxyl groups for cross-linking,
- (II) a fixing agent which comprises the aqueous solution of a non-plasticized phenol-, urea-, or melamine-aldehyde resin, and
- (III) as curing agent a compound which acts as an acid under the reaction conditions,
- and after padding or printing, fixing by dry heat.
Dependencies are inferred from the claim text.