SU1040010A1 - Process for bleaching cellulose - Google Patents

Description

luloses with drbavk other-azoproizvodny lignin. The results show in all cases an increase in the yield, a grade: l of polymerization and a slight increase in whiteness. 5

Thus, the introduction of azo derivatives of lignin in the process of oxygen-base treatment of unbleached cellulose

provides selectivity of delignification in the process of oxygen-alkali treatment of various types of pulp with a decrease in residual lignin and, accordingly, an increase in whiteness, while simultaneously increasing the yield of cellulose due to the inhibition of cellulose depolymerization in an alkaline medium.

Table 1 1

93.01

L No.: Nin-azo-anthranilic acid, 1

0.91

5.6

1202

95 L6

lOifZ 9, "9 1089 94.79 982 9A, 29 1030

Bav9t, 87

1005

9.38 9i; 52 93, 93 L5

92.3

Lignin-azo-p-nitroaniline, 0.5

Lignin-azo- (X “-naphthylamine, O, J

Lignin-azo-p.-Nitroaniline, 1.0

table 2

93,

0.80 93.25 0.50 92.07 0.25 92.7 f 0.25

9t, l80, A7

at

Table 3

45.3

1.23 52.3 1.01 57.6 0.73 60.0 0.60

0.84

54,8

Table 4

54.5

0.90

57.1

0.70 0.83 55.0

63.2 0.47

eight

lOtOOlO Continued table.

Claims (2)

I 1. METHOD OF WHITENING CELLULO- Threat by oxygen-alkaline treatment of unbleached cellulose in the presence of an organic additive, which means that, in order to increase the yield of the target product and increase the selectivity of delignification, the ligno azo compound in the general formula is used as an organic additive -C- \ I -Οι -from- OH 'where B-C00H, I, B0 ₂ ' SI,, SO _Э Н, ОСН,, ΒΗ ₂ -θ-, ΒΗ ₂ 2. The method of claim 1 liter of t and h s with a rout I in that the azo compound _{of the} lignin used in an amount of 0.1-2.0% of the bone dry fiber.