EP 1241296 A2 20020918 - Process for stabilizing brightness of lignin-containing fibrous material, a composition for stabilizing the brightness thereof and thus stabilized fibrous material
Title (en)
Process for stabilizing brightness of lignin-containing fibrous material, a composition for stabilizing the brightness thereof and thus stabilized fibrous material
Title (de)
Verfahren zur Weissgradstabilisierung ligninhaltiger Faserstoffmaterialien, Stabilisatorzusammensetzung und damit stabilisierter Faserstoffmaterialien
Title (fr)
Procédé pour la stabilisation du degré de blancheur de matières fibreuses contenant de la lignine, composition pour stabiliser son degré de blancheur et matières fibreuses ainsi stabilsées
Publication
Application
Priority
DE 10112101 A 20010314
Abstract (en)
(Cyclo)aliphatic thiols with other hydrophilic groups, unsaturated thiols, and thiols or di- and poly-sulfides with hetero-atoms are used to prevent light-induced yellowing in lignin-containing fibre materials. Thioglycerol, dithiothreitol mercaptoacetic acid and 2- or 3-mercaptopropionic acid are not included. A method for stabilizing the degree of whiteness of lignin-containing fibre materials (LFM) against light-induced yellowing by the use of thio compounds (I) as stabilizers, in which (I) comprise: (i) thiols with aliphatic or cycloaliphatic thiol group(s) and other hydrophilic group(s) selected from -OH, -NH2, -NHR<1>, -NR<1>R<2>, -COOH, -SO3H, -PO3H2 or salts of these acids and bases; (ii) thiols with (cyclo)aliphatic thiol group(s) and C=C double bond(s); (iii) thiols with thiol group(s) attached to a hetero atom; and (iv) di- or poly-sulfides with hetero atom(s) attached to the di- or poly-sulfide groups. R<1>, R<2> = 1-4C alkyl, 2-4C hydroxyalkyl (e.g. hydroxyethyl or dihydroxypropyl), 2-4C alkanoyl or hydroxyalkanoyl. Independent claims are also included for: (1) lignin-containing LFM with a stabilized degree of whiteness, especially paper and cardboard from mechanically-produced (thermo-mechanically or chemo-thermo-mechanically) wood pulp or high-yield pulp, containing (I) in the fibre material itself or in a layer formed by impregnation, sizing or coating; (2) compositions containing (I) in an aqueous, organic or aqueous-organic liquid or paste-like medium which can be applied by spraying or coating; and (3) UV absorbers for stabilizing the degree of whiteness of LFM, comprising compounds of formula HO-Ar-CH=C(R<3>)-CO-R<4>. R<3> = H, 1-12C alkanoyl (especially acetyl, propionyl or n-butanoyl) or 1-12C alkoxycarbonyl (especially -COOCH3 or -COOC2H5); R<4> = 1-12C alkyl, especially methyl, ethyl, n-propyl, iso-propyl or n-butyl; Ar = phenylene or naphthylene, with OH in the ortho or para position to the C=C group and optionally substituted with alkyl (preferably methyl, ethyl, n- or iso-propyl, n-, sec.- or tert.-butyl), alkoxy (preferably methoxy or ethoxy), phenyl, p-(o-)-hydroxy-phenyl, benzoyl, -COOH or -SO3H
Abstract (de)
Ligninhaltige Faserstoffmaterialien, insbesondere Papier und Karton, werden zwecks Minderung der lichtinduzierten Vergilbung mit Weißgradstabilisatoren ausgerüstet. Erfindungsgemäß werden (i) Thiole mit mindestens einer zusätzlichen hydrophilen Gruppe aus der Reihe OH, NH2, NHR<1>, NR<1>R<2>, COOH, SO3H und PO3H2 sowie Aminosäure-/Peptidstruktur (ii) Thiole mit einer CC-Doppelbindung (iii) oder heteroaromatische Thiole und (iv), heteroaromatische Disulfide oder Polysulfide als Weißgradstabilisator eingesetzt. Vorteilhaft werden zusätzlich HALS-Lichtstabilisatoren und/oder UV-Stabilisatoren eingesetzt. Die Stabilität wird durch einen TiO2-haltigen Strich auf dem Faserstoffmaterial weiter erhöht. Gegenstand der Erfindung sind ferner Stabilsatorzusammensetzungen und erfindungsgemäß stabilisierte Faserstoffmaterialien, enthaltend einen Weißgradstabilisator der Gruppe (i) bis (iv).
IPC 1-7
IPC 8 full level
D21H 21/14 (2006.01)
CPC (source: EP US)
D21H 21/143 (2013.01 - EP US)
Designated contracting state (EPC)
AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR
DOCDB simple family (publication)
EP 1241296 A2 20020918; EP 1241296 A3 20021016; AU 2611702 A 20020919; AU 779547 B2 20050127; CA 2376543 A1 20020914; DE 10112101 A1 20020919; NO 20021248 D0 20020313; NO 20021248 L 20020916; NZ 517679 A 20040227; US 2002174491 A1 20021128
DOCDB simple family (application)
EP 02003529 A 20020215; AU 2611702 A 20020314; CA 2376543 A 20020312; DE 10112101 A 20010314; NO 20021248 A 20020313; NZ 51767902 A 20020307; US 9397002 A 20020311