Inhibition of pulp and paper yellowing using hydroxylamines and other coadditives

A composition having reduced loss of brightness and enhanced resistance to yellowing which comprises

• (a) a chemical paper which may still contain traces of lignin, and
• (b) an amount which is effective to reduce loss of brightness and enhance resistance to yellowing of an N,N-dialkylhydroxylamine, an ester, amide or thio substituted N,N-dialkylhydroxylamine or N,N-dibenzylhydroxylamine of formula I, II or III
• R1R2N—OH (I)
• (T1SCH2)(T2SCH2)N—OH (II)
• (E1COCH2CH2)(E2COCH2CH2)N—OH (III)
• where
• R1 and R2 are independently alkyl of 1 to 18 carbon atoms, alkyl of 1 to 18 carbon atoms substituted by a hydroxyl group;
• or benzyl;
• T1 and T2 are independently alkyl of 1 to 4 carbon atoms, phenyl, 3,5-di-tert-butyl-4-hydroxy-phenyl, benzyl or —CH2COOH;
• E1 and E2 are independently —OE3, —NHE3 or —NE3E4 where E3 and E4 are independently hydrogen, alkyl of 1 to 4 carbon atoms or said alkyl substituted by one hydroxyl group;
• or
• of an acid salt of formula IA, IIA or IIIA
• (R1R2NH—OH)h+(X−)j (IA)
• [(T1SCH2)(T2SCH2)NH—OH]h+(X31 )j (IIA)
• [(E1COCH2CH2)(E2COCH2CH2)NH—OH]h+(X−)j (IIIA)
• where
• R1, R2, T1, T2, E1 and E2 are as defined above,
• X is an inorganic or organic anion, and
• the total charge of cations h is equal to the total charge of anions j.