GB2068430A

GB2068430A - Stable Solutions of Optical Brighteners

Info

Publication number: GB2068430A
Application number: GB8103109A
Authority: GB
Original assignee: Sandoz Products Ltd
Current assignee: Novartis Pharmaceuticals UK Ltd
Priority date: 1980-02-05
Filing date: 1981-02-02
Publication date: 1981-08-12
Also published as: GB2068430B

Abstract

A stable aqueous solution comprising a) 5-25% by weight of an optical brightening agent of formula I <IMAGE> in which R1 to R9, X and A<6> are defined in the specification b) 5-70% by weight of an organic monobasic acid or a mixture of organic monobasic acids selected from formic, acetic, propionic, butyric, glycollic and lactic acids, c) 0-45% by weight citric acid d) 5-55% by weight water the total amount of organic acids present being at least 40% by weight of the total composition.

Description

SPECIFICATION Stable Solutions of Optical Brighteners This invention relates to stable aqueous solutions of certain benzimidazole optical brighteners.

The invention provides a stable aqueous solution comprising a) 5-25% by weight of an optical brightening agent of formula I

in which X is N or CR5, A# is an anion and 1) whenXisN: R1, R2 and R4 are hydrogen and Re and B7 are in the 3 and 4 position respectively R3 is C1-4alkoxy, unsubstituted or monosubstituted by phenyl or (C1-4alkoxy)carbonyl; one of R8 and R7 is hydrogen or methyl, the other being hydrogen; R5 is C1-4alkyl unsubstituted or monosubstituted by phenyl or (C1-4alkoxy)carbonyl, and R9 is C1-4alkyl, or 2) when X is CR5 where R5 is hydrogen, C1-4alkyl, phenyl or phenyl substituted by methyl and/or methoxy:: R1 is hydrogen, halogen, C1-4alkyl, C1-4alkoxy or together with R2 forms a fused benzene ring R2 is hydrogen, halogen, C1~4alkyl, C1-4alkoxy, -COOR, -CONRR or -SO2R', in which each R independently is H or C1-4alkyl and R' is -OH, C1-4alkyl, C1-4alkoxy, or-NRR; C1-4alkyl and R' is-OH, C1-4alkyl, C1-4alkoxy, or -NRR; or together with R1 or R3 forms a fused benzene ring R3 is hydrogen, halogen, C1-4alkyl, C1-4alkoxy or together with R2 or R4 forms a fused benzene ring R4 is hydrogen, halogen, C1-4alkyl, C1-4alkoxy or together with R3 forms a fused benzene ring R6 is hydrogen, halogen, C1-4alkyl, C1-4alkoxy, phenyl, (C1-4alkyl)sulphonyl or phenylsulphonyl R7 is hydrogen, halogen, C1-4alkyl or C1-4alkoxy Re is C1~4alkyl unsubstituted or substituted by phenyl;; C2~4hydroxyalkyl; cyanoethyl; phenyl unsubstituted or monosubstituted by halogen, C1~4alkyl or C1-4alkoxy; or C4~8cycloalkyl; and R9 is C1-4alkyl unsubstituted or substituted by phenyl, C2-4 hydroxyalkyl, (C1-4alkoxy) C2-4alkyl, -CH2CN, -CH2CONH2 or-CH2-COOR" where R" is C1~4alkyl, b) 5-70% by weight of an organic monobasic acid or a mixture of organic monobasic acids selected from formic, acetic, propionic, butyric, glycollic and lactic acids, c) 0-45% by weight citric acid d) 5-55% by weight water the total amount of organic acids present being at least 40% by weight, preferably 45-65% by weight of the total composition.

Preferred compounds of formula I in which X is N are those of formula I'

in which R3, is methoxy or (C1~2alkoxy)carbonylmethoxy Ao, Re and R, are as defined above, R8' is C1~2alkyl, unsubstituted or monosubstituted by phenyl or (C1-4alkoxy)carbonyl, and R9' is methyl or ethyl.

Particularly preferred is the compound of formula I' in which R3, is methoxy, R6=R7=H, and R8'=R9'=methyl, particularly the salt form in which Ae is a halide or CH3SO4# anion or mixtures thereof.

The term 'halogen' used herein means F, CI or Br, and 'halide' means Fe, Cl# or Br#, Preferred compounds of formula I in which X is CR5 are those of formula 11

in which F''í and R'2 are each hydrogen or together form a fused benzene ring R is hydrogen, methoxy or methyl R'5 is hydrogen or methyl R' is hydrogen, methyl, methoxy, chlorine or methylsulphonyl R'8 is methyl, phenyl or benzyl and R'g is methyl or benzyl.

Of the compounds of formula I' and í8, those offormula I' are preferred.

Component b) is preferably formic, acetic, glycollic or lactic acid, or mixtures thereof. Acetic acid, glycollic acid and mixtures thereof are particularly preferred.

Preferred compositions contain 7-20% by weight of component a) and either 1030% by weight of component b) and 25-40% by weight of component c), or 45-65% by weight of component b) and no component c).

The compositions of the invention may contain minor amounts of additional components, for example scented materials such as pine oil to mask any unpleasant odour from the organic acids.

The optical brighteners of formula I are known, and their preparation is described for example in German Offenlegungsschrift 2,733,439 and Swiss Patent 593,967.

The compositions of the invention may be prepared in conventional manner by stirring the components together, e.g. at room temperature, until a homogeneous solution results.

The resulting compositions are useful as aqueous concentrates which may be diluted as required to give an aqueous treatment bath for the optical brightening of textile fibres, particularly of polyacrylonitrile. The compositions are stable, that is, they do not deposit any solid material on storage for up to several months at temperatures between 0 C and 450C.

The following Examples, in which all parts and percentages are by weight, illustrate the invention: Example 1 150 Parts of the optical brightener of formula

were stirred at 200C with 250 parts of water and 600 parts of glacial acetic acid, to give a clear pale yellow solution, stable at OOC, ambient temperature and 45 C for at least six months.

Example 2 1 50 Parts of the optical brightener given in Example 1 were stirred at 200C with 314 parts water, 50 parts glacial acetic acid, 300 parts anhydrous citric acid and 18 parts of 70% wt. aqueous glycollic acid until a clcar pale yellow solution was obtained having the following composition (% by wt) a) optical brightener 15% b) monobasic acids 18% (acetic acid 5%, glycollic acid 13%) c) citric acid 30% d) water 37%.

The composition is stable at OOC, ambient temperature and 450C for at least 2 months, and has very little odour.

Example 3 1 50 Parts of the optical brightener of formula

where stirred at 20 C with 250 parts water, 100 parts glacial acetic acid, 300 parts anhydrous citric acid and 200 parts 70% glycollic acid, to give a clear pale yellow liquid stable at 0 C for at least 5 weeks and having the following composition: (% by wt.) a) optical brightener 15% b) monobasic acids 24% (acetic acid 10%, glycollic acid 14%) c) citric acid 30% d) water 31%.

Example 4 1 50 Parts of the optical brightener of formula

were stirred at 200C with 260 parts water, 300 parts citric acid and 300 parts 70% glycollic acid to give a pale yellow odourless solution, stable at 00for at least 5 weeks and having the composition a) optical brightener 15% b) glycollic acid 21% c) citric acid 30% d) water 34% Example 5 A solution the same as that of Example 3 was formulated except that the optical brightener of formula

was used instead of the optical brightener of Example 3. A pale yellw so7ution with very little odour and stable at 0 C for at least 5 weeks was obtained.

Example 6 A solution the same as that of Example 3 was formulated except that the optical brightener of formula

was used instead of the optical brightener of Example 3.

Example 7 A solution the same as that of Example 1 was formulated except that the optical brightener of formula

was used instead of the optical brightener of Example 1.

Claims

1. A stable aqueous solution comprising a) 5-25% by weight of an optical brightening agent of formula I

in which Xis N or CR5,Ae is an anion and 1)whenXisN: R1, R2 and R4 are hydrogen and R8 and R, are in the 3 and 4 position respectively R3 is C1-4alkoxy, unsubstituted or monosubstituted by phenyl or (C1-4alkoxy)carbonyl; one of R8 and R7 is hydrogen or methyl, the other being hydrogen; R8 is C1-4alkyl unsubstituted or monosubstituted by phenyl or (C1-4alkoxy)carbonyl, and R9 is C1-4alkyl, or 2) when X is CR5 where R5 is hydrogen, C1-4alkyl, phenyl or phenyl substituted by methyl and/or methoxy:: R1 is hydrogen, halogen, C1-4alkyl, C1-4alkoxy or together with R2 forms a fused benzene ring R2 is hydrogen, halogen, C1-4alkyl, C1-4alkoxy, -COOR, -CONRR or -SO2R', in which each R independently is H or C1-4alkyl and R' is-OH, C1-4alkyl, C1-4alkoxy, or-NRR; C1-4alkyl and R' is-OH, C1-4alkyl, C1-4alkoxy, or-NRR; or together with R1 or R3 forms a fused benzene ring R3 is hydrogen, halogen, C1-4alkyl, C1-4alkoxy or together with R2 or R4 forms a fused benzene ring R4 is hydrogen, halogen, C1-4alkyl, C1-4alkoxy or together with R3 forms a fused benzene ring R6 is hydrogen, halogen, C1-4alkyl, C1-4alkoxy, phenyl, (C1-4alkyl)sulphonyl or phenylsulphonyl R7 is hydrogen, halogen, C1-4alkyl, or C1-4alkoxy R8 is C1-4alkyl unsubstituted or substituted by phenyl;C2-4hydroxyalkyl; cyanoethyl; phenyl unsubstituted or monosubstituted by halogen, C1-4alkyl or C14alkoxy; or C4-8cycloalkyl; and R9 is C1-4alkyl unsubstituted or substituted by phenyl, C2-4hydroxyalkyl, (C1-4alkoxy) C2-4alkyl, -CH2CN, -CH20NH2 or -CH2-COOB" where R" is C1~4alkyl, b) 5-70% by weight of an organic monobasic acid or a mixture of organic monobasic acids selected from formic, ascetic, propionic, butyric, glycollic and lactic acids, c) 0-45% by weight citric acid d) 5-55% by weight water the total amount of organic acids present being at least 40% by weight of the total composition.

2. A solution as claimed in Claim 1 in which in component a) X is N.

3. A solution as claimed in Claim 2 in which component a) is an optical brightening agent of formula

in which R3 is methoxy or C1~2alkoxy carbonyl R8' is C12alkyI, unsubstituted or monosubstituted by phenyl or (C1-4alkoxy)carbonyl, R9 is methyl or ethyl, and R8, R, and Ao are defined in Claim 1.

4. A solution as claimed in Claim 3 in which in component a) R3 is methoxy, R6=R,=hydrogen and R8=Rg=methyl.

5. A solution as claimed in any one of the preceding claims in which Ao is halide or CH3SO4# anion.

6. A solution as claimed in any one of the preceding claims in which component b) is formic, acetic, glycollic or lactic acid or mixtures thereof.

7. A solution as claimed in Claim 6 in which component b) is acetic or glycollic acid, or mixtures thereof.

8. A solution as claimed in any one of the preceding claims in which the total amount of organic acids present is from 45-65% by weight of the total composition.

9. A solution as claimed in any one of the preceding claims in which the amount of component a) is 720%, the amount of component b) is 10-30% and component c) is 25 to 40%.

10. A solution as claimed in any one of Claims 1 to 8 in which the amount of component a) is 720%, the amount of component b) is 45 to 65% and the amount of component c) is zero.

11. A solution as claimed in any one of the preceding claims including scented materials.

12. A solution as claimed in Claim 10 including pine oil.

13, A solution substantially as herein described with reference to any one of Examples 1 to 7.