Non-bleeding indicator and dyes therefor

Claim 2

A non-bleeding pH indicator consisting essentially of an insoluble polymer carrier having free hydroxyl or NH groups or mixtures thereof, and bound to said carrier an organic azo dyestuff capable of changing color in response to a change in pH, said carrier having been reacted with a dyestuff of the formula Ar -- N = N -- Ar wherein Ar is aryl forming with the azo group said organic azo dyestuff, with the provision that at least one aryl group is substituted by at least one reactive group capable of forming a chemical bond with said carrier, and at least one aryl group is substituted by at least one other radical selected from the group consisting of --SO 3 H and --COOH, said reactive group being 2-(hydroxysulfonyloxy)-ethylsulfonyl, N-methyl-N-[2-(hydroxysulfonyloxy)-ethyl]-sulfonamido, monochlorotriazinyl, dichlorotriazinyl, mono-, di- and trichloropyrimidyl, dichloropyridazinyl, dichloroquinoxalinyl, dichlorophthalazinyl or 2-(hydroxy-sulfonyloxy)-ethylaminosulfonyl.

Claim 3

An indicator as defined by claim 1 wherein said reactive group is 2-hydroxysulfonyloxy-ethylsulfonyl or N-methyl-N-(2-hydroxysulfonyloxy-ethylsulfonyl)-amido.

Claim 4

An indicator as defined by claim 2 wherein said carrier is cellulose.

Claim 5

An indicator as defined by claim 1 wherein said organic azo dyestuff comprises a member selected from the group consisting of 4anilino-3'-(2-hydroxysulfonyloxy-ethylsulfonyl)-azobenzene-6'-carboxylic acid, 1-[2-chloro-5-(2-hydroxysulfonyloxy-ethylsulfonyl)-phenylazo]-2-naphthol-3,6-disulfonic acid, 4-methylamino-4'-[N-methyl-N-(2-hydroxysulfonyloxy-ethylsulfonyl)-amido]-azobenzene-5-sulfonic acid, 4-(N-benzyl-N-ethylamino)-3'-(2-hydroxysulfonyloxy-ethylsulfonyl)-azobenzene-6'-carboxylic acid 2-(2-sulfo-4,6-dinitrophenylazo)-6-[N-methyl-N-(2-hydroxysulfonyloxy-ethylsulfonyl)-amido]-1-naphthol-3-sulfonic acid, 2-(2,4-dinitrophenylazo)-6-[N-methyl-N-(2-hydroxysulfonyl-oxy-ethylsulfonyl)-amido]-1-naphthol-3-sulfonic acid, 2-[2-nitro-4-(2-hydroxysulfonyloxy-ethylsulfonyl)-phenylazo]-1-naphthol-3,6-disulfonic acid, 4-anilino-3'-(2-hydroxysulfonyloxy-ethylsulfonyl)-azobenzene-6'-sulfonic acid, 2-[2-nitro-4-(2-hydroxysulfonyloxy-ethylsulfonyl)-phenylazo]-1-naphthol-3-sulfonic acid, 2-(4-hydroxynaphthyl-1-azo)-4-(2-hydroxysulfonyloxy-ethylsulfonyl)-benzenesulfonic acid, 4-[N-methyl-N-(2-hydroxysulfonyloxy-ethylsulfonyl)-amido]-2'-dimethylamino-azobenzene-6'-sulfonic acid, 1.[2-nitro-4-(2-hydroxysulfonyloxy-ethylsulfonyl)-phenylazo]-2-naphthol-7-sulfonic acid, 1-[2-nitro-4-(2-hydroxysulfonyloxy-ethylsulfonyl)-phenylazo]-2-naphthol-6,8-disulfonic acid, 2-[2-hydroxy-6-(2-hydroxysulfonyloxy-ethylsulfonyl)-1-naphthylazo]-3,5-dinitrobenzene-sulfonic acid and 4-[N-methyl-N-(2-hydroxysulfonyloxy-ethylsulfonyl)-amido]-2'-dimethylamino-azobenzene-6'-carboxylic acid.

Claim 6

An indicator as defined by claim 1 wherein said indicator is in the form of a substantially inflexible shaped object.

Claim 7

An indicator as defined by claim 1 wherein said dyestuff is of the formula ##STR12## wherein the rings represent benzene or naphthalene rings; one of the residues R 1 to R 7 is a 2-(hydroxysulfonyloxy)ethylsulfonyl group or a N-methyl-N-[2-(hydroxysulfonyloxy)ethyl]-sulfonamido group; another residue is a COOH-- or SO 3 H-group; one of the residues R 1 to R 3 represents an amino group optionally substituted by one or two alkyl groups of 1-4 carbon atoms respectively and/or a phenyl or benzyl group, or represents an OH-group; and the remaining residues R 1 to R 7 represents H, OH, alkyl of 1-4 carbon atoms or alkoxy of 1-4 carbon atoms, Cl, Br, NO 2 or SO 3 H.

Claim 8

An indicator as defined by claim 1 wherein said dyestuff is of the formula ##STR13## wherein Ar 1 represents 1- or 2-naphthyl substituted by an OH-- group and one or two SO 3 H-groups.

Claim 9

An indicator as defined by claim 1 wherein said dyestuff is of the formula ##STR14## wherein Ar 1 represents 1- or 2-naphthyl substituted by an OH-- group and one or two SO 3 H-groups; X represents NO 2 , Cl or Br; and one of the Y groups represents--SO 2 --CH 2 CH 2 --O--SO 2 --OH and the other H.

Claim 10

An indicator as defined by claim 1 wherein said dyestuff is of the formula ##STR15## wherein Ar 1 represents 1- or 2-naphthyl substituted by an OH-- group and one or two SO 3 H-groups; and R 8 represents COOH or SO 3 H.

Claim 11

An indicator as defined by claim 1 wherein said dyestuff is of the formula ##STR16## wherein R 8 represents COOH or SO 3 H; R 9 represents methylamino, dimethylamino, ethylamino, diethylamino, anilino, N-methyl-N-benzylamino or N-ethyl-N-benzylamino; and R 10 represents H, CH 3 , COOH or SO 3 H.

Claim 12

An indicator as defined by claim 1 wherein said dyestuff is of the formula ##STR17## wherein R 8 represents COOH or SO 3 H; and R 11 represents methylamino, dimethylamino, ethylamino or diethylamino.

Claim 13

An indicator as defined by claim 1 wherein said dyestuff is of the formula ##STR18## wherein Ar 2 represents a naphthyl residue substituted in the 1- or 2-position by an OH-group, and in the 6-position by an HO--SO 2 --O--CH 2 CH 2 --SO 2 -- or HO--SO 2 O--CH 2 CH 2 --SO 2 --N(CH 3 )--, and optionally by an SO 3 H-group; R 12 is H or NO; and R 13 is H or SO 3 H; but wherein at least one SO 3 H-group must be contained.

Claim 14

An indicator as defined by claim 1 wherein said dyestuff is of the formula ##STR19## wherein R 8 represents COOH or SO 3 H; R 11 represents methylamino, dimethylamino, ethylamino or diethylamino, and R 14 represents H or OCH 3 , and one of the Z groups represents HO--SO 2 --O--CH 2 CH 2 --SO 2 --, and the other H or CH 3 .

Claim 15

An indicator as defined by claim 1 wherein said dyestuff is of the formula ##STR20## wherein Ar 1 represents 1- or 2-naphthyl substituted by an OH--group and one or two SO 3 H-groups.

Claim 16

An indicator as defined by claim 1, said dyestuff being selected from the group consisting of 4anilino-3'-(2-hydroxysulfonyloxy-ethylsulfonyl)-azobenzene-6'-carboxylic acid; 6-dimethylamino-3'-(2-hydroxysulfonyloxy-ethylsulfonyl)-azobenzene-2-carboxylic acid; 4-ethylamino-4'-(2-hydroxysulfonyloxy-ethylsulfonyl)-azobenzene-5-carboxylic acid; 6-dimethylamino-4'-(2-hydroxysulfonyloxy-ethylsulfonyl)-6'-methoxy-azobenzene-2-carboxylic acid; 6-dimethylamino-3'-methyl-4'-(2-hydroxysulfonyloxy-ethylsulfonyl)-6'-methoxy-azobenzene-2-carboxylic acid; 6-dimethylamino-3'-(2-hydroxysulfonyloxy-ethylsulfonyl)-azobenzene-2,6'-dicarboxylic acid; 2-sulfo-6-dimethylamino-3'-(2-hydroxysulfonyloxy-ethylsulfonyl)-azobenzene-6'-carboxylic acid; 4-ethylamino-3'-(2-hydroxysulfonyloxy-ethylsulfonyl)-azobenzene-5,6'-dicarboxylic acid; 4-methylamino-5-sulfo-3'-(2-hydroxysulfonyloxy-ethylsulfonyl)-azobenzene-6'-carboxylic acid; 4-methylamino-3'-(2-hydroxysulfonyloxy-ethylsulfonyl)-azobenzene-5,6'-dicarboxylic acid; 4-dimethylamino-3'-(2-hydroxysulfonyloxy-ethylsulfonyl)-azobenzene-6'-carboxylic acid; 4-methylamino-3'-(2-hydroxysulfonyloxy-ethylsulfonyl)-azobenzene-6'-carboxylic acid; 4-ethylamino-5-methyl-3'-(2-hydroxysulfonyloxy-ethylsulfonyl)-azobenzene-6'-carboxylic acid; 4-diethylamino-3'-(2-hydroxysulfonyloxy-ethylsulfonyl)-azobenzene-6'-carboxylic acid; 4-methylamino-4'-[N-methyl-N-(2-hydroxysulfonyloxy-ethylsulfonyl)-amido]-azobenzene-5-carboxylic acid; 4-(N-benzyl-N-ethylamino)-3'-(2-hydroxysulfonyloxy-ethylsulfonyl)-azobenzene-6'-carboxylic acid; and 4-[N-methyl-N-(2-hydroxysulfonyloxy-ethylsulfonyl)-amido]-2'-dimethylamino-azobenzene-6'-carboxylic acid.

Claim 17

An indicator as defined by claim 1, said dyestuff being selected from the group consisting of 4-ethylamino-3'-(2-hydroxysulfonyloxy-ethylsulfonyl)-azobenzene-5-sulfonic acid; 6-dimethylamino-4'-(2-hydroxysulfonyloxy-ethylsulfonyl)-azobenzene-2-sulfonic acid; 4-ethylamino-4'-(2-hydroxysulfonyloxy-ethylsulfonyl)-azobenzene-5-sulfonic acid; 4-methylamino-4'-(2-hydroxysulfonyloxy-ethylsulfonyl)-6'-methoxy-azobenzene-5-sulfonic acid; 2-[2-sulfo-5-(2-hydroxysulfonyloxy-ethylsulfonyl)-phenylazo]-1-naphthol-3,6-disulfonic acid; 2-[2-sulfo-5-(2-hydroxysulfonyloxy-ethylsulfonyl)-phenylazo]-1-naphthol-3-sulfonic acid; 1-[2-sulfo-5-(2-hydroxysulfonyloxy-ethylsulfonyl)-phenylazo]-2-naphthol-3,6-disulfonic acid; 1-[2-sulfo-5-(2-hydroxysulfonyloxy-ethylsulfonyl)-phenylazo]-2-naphthol-6-sulfonic acid; 6-dimethylamino-3'-(2-hydroxysulfonyloxy-ethylsulfonyl)-azobenzene-2,6'-disulfonic acid; 4-ethylamino-3'-(2-hydroxysulfonyloxy-ethylsulfonyl)-azobenzene-5,5'-disulfonic acid; 4-ethylamino-3'-methyl-4'-(2-hydroxysulfonyloxy-ethylsulfonyl)-6'-methoxy-azobenzene-5-sulfonic acid; 4-methylamino-3'-methyl-4'-(2-hydroxysulfonyloxy-ethylsulfonyl)-6'-methoxy-azobenzene-5-sulfonic acid; 4-ethylamino-4'-[N-methyl-N-(2-hydroxysulfonyloxy-ethylsulfonyl)-amido]-azobenzene-5-sulfonic acid; 4-methylamino-4'-[N-methyl-N-(2-hydroxysulfonyloxy-ethylsulfonyl)-amido]-azobenzene-5-sulfonic acid; 4-anilino-3'-(2-hydroxysulfonyloxy-ethylsulfonyl)-azobenzene-6'-sulfonic acid; 2-(4-hydroxynaphthyl-1-azo)-4-(2-hydroxysulfonyloxy-ethylsulfonyl)-benzenesulfonic acid; and 4-[N-methyl-N-(2-hydroxysulfonyloxy-ethylsulfonyl)-amido]2'-dimethylamino-azobenzene-6'-sulfonic acid.

Claim 18

An indicator as defined by claim 1, said dyestuff being selected from the group consisting of 1-[p-(2-hydroxysulfonyloxy-ethylsulfonyl)-phenylazo]-2-naphthol-6,8-disulfonic acid; 1-[2-bromo-4-(2-hydroxysulfonyloxy-ethylsulfonyl)-phenylazo]-2-naphthol-3,6-disulfonic acid; 1-[2-bromo-4-(2-hydroxysulfonyloxy-ethylsulfonyl)-phenylazo]-2-naphthol-6,8-disulfonic acid; 1-[2-bromo-4-(2-hydroxysulfonyloxy-ethylsulfonyl)-phenylazo]-2-naphthol-6-sulfonic acid; 1-[2-nitro-4-(2-hydroxysulfonyloxy-ethysulfonyl)-phenylazo]-2-naphthol-3,6-disulfonic acid; 2-[2-nitro-4-(2-hydroxysulfonyloxy-ethylsulfonyl)-phenylazo]-1-naphthol-4-sulfonic acid; 1-[2-nitro-4-(2-hydroxysulfonyloxy-ethylsulfonyl)-phenylazo]-2-naphthol-6-sulfonic acid; 1-[2-(2-hydroxysulfonyloxy-ethylsulfonyl)-phenylazo]-2-naphthol-3,6-disulfonic acid; 1-2,6-dibromo-4-(2-hydroxsulfonyloxy-ethylsulfonyl)-phenylazo]-2-naphthol-3,6-disulfonic acid; 1-[2-chloro-5-(2-hydroxysulfonyloxy-ethylsulfonyl)-phenylazo]-2-naphthol-3,6-disulfonic acid; 1-[2-chloro-5-(2-hydroxysulfonyloxy-ethylsulfonyl)-phenylazo]-2-naphthol-7sulfonic acid; 2-[2-hydroxy-3-nitro-5-(2-hydroxysulfonyloxy-ethylsulfonyl)phenylazo]-1-naphthol-3,8-disulfonic acid; 2-[2-hydroxy-3-nitro-5-(2-hydroxysulfonyloxy-ethylsulfonyl)-phenylazo]-1-naphthol-3-sulfonic acid; 1-[2-hydroxy-3-nitro-5-(2-hydroxysulfonyloxy-ethylsulfonyl)phenylazo]-2-naphthol-6-sulfonic acid; 2-(2-sulfo-4-nitrophenylazo)-6-(2-hydroxysulfonyloxy-ethylsulfonyl)-1-naphthol-3-sulfonic acid; 2-[2-hydroxy-6-(2-hydroxysulfonyloxy-ethylsulfonyl)-1-naphthylazo]-5-nitrobenzenesulfonic acid; 2-(2-sulfo-4,6-dinitrophenylazo)-6-[N-methyl-N-(2-hydroxysulfonyloxy-ethylsulfonyl)-amido]-1-naphthol-3-sulfonic acid; 2-(2,4-dinitrophenylazo)-6-[N-methyl-N-(2-hydroxysulfonyloxy-ethylsulfonyl)-amido]-1-naphthol-3-sulfonic acid; 2-[2-nitro-4-(2-hydroxysulfonyloxy-ethylsulfonyl)-phenylazo]-1-naphthol-3,6-disulfonic acid; 2-[2-nitro-4-(2-hydroxysulfonyloxy-ethylsulfonyl-phenylazo]-1-naphthol-3-sulfonic acid; 1-[2-nitro-4-(2-hydroxysulfonyloxy-ethylsulfonyl0-phenylazo]-2-naphthol-7sulfonic acid; 1-[2-nitro-4-(2-hydroxysulfonyloxy-ethylsulfonyl)-phenylazo]-2-naphthol-6,8-disulfonic acid; and 2-[2-hydroxy-6-(2-hydroxysulfonyloxy-ethylsulfonyl)-1-naphthylazo]-3,5-dinitrobenzenesulfonic acid.

Claim 19

An indicator as defined by claim 1 wherein said carrier is cellulose.

Claim 20

An indicator as defined by claim 1 wherein said carrier is in the form of a powder.

Claim 21

An indicator as defined by claim 19 wherein said powder is microcrystalline cellulose.

Claim 22

An indicator as defined by claim 1, said dyestuff being 1-[2-chloro-5-(2-hydroxysulfonyloxy-ethylsulfonyl)-phenylazo]-2-naphthol-3,6-disulfonic acid.

Claim 23

An indicator as defined by claim 1, said dyestuff being 2-(4-hydroxynaphthyl-1azo)-4-(2-hydroxysulfonyloxy-ethylsulfonyl)-benzenesulfonic acid.

Claim 24

An indicator as defined by claim 1, said dyestuff being 2-[2-nitro-4-(2-hydroxysulfonyloxy-ethylsulfonyl)-phenylazo]-1-naphthol-3,6-dixulfonic acid.

Claim 25

An indicator as defined by claim 1, said dyestuff being 1-[2-nitro-4-(2-hydroxysulfonyloxy-ethylsulfonyl)-phenylazo]-2-naphthol-7-sulfonic acid.

Claim 26

An indicator as defined by claim 1, said dyestuff being 4-anilino-3'-(2-hydroxysulfonyloxy-ethylsulfonyl)-azobenzene-6'-carboxylic acid.

Claim 27

An indicator as defined by claim 1, said dyestuff being 4-methylamino-4'-(N-methyl-N-[2-(hydroxysulfonyloxy)-ethyl]-sulfonamido)-azobenzene-5-sulfonic acid.

Claim 28

An indicator as defined by claim 1, said dyestuff being 4-(N-methyl-N-[2-(hydroxysulfonyloxy)-ethyl]-sulfonamido)-2'-dimethylamino-azobenzene-6'-sulfonic acid.

Claim 29

An indicator as defined by claim 1, said dyestuff being 2-(2,4-dinitrophenylazo)-6-(N-methyl-N-[2-(hydroxysulfonyloxy)-ethyl]-sulfonamido)-1-naphthol-3-sulfonic acid.

Claim 30

An indicator as defined by claim 1, said dyestuff being 1-[2-nitro-4-(2-hydroxysulfonyloxy-ethylsulfonyl)-phenylazo]-2-naphthol-6,8 -disulfonic acid.

Claim 31

An indicator as defined by claim 1, said dyestuff being 2-(2-sulfo-4,6-dinitro-phenylazo)-6-(N-methyl-N-[2-(hydroxysulfonyloxy)-ethyl]-sulfonamido)-1-naphthol-3-sulfonic acid.

Claim 32

An indicator as defined by claim 1, said dyestuff being 4-(N-methyl-N-[2-(hydroxysulfonyloxy)-ethyl]-sulfonamido)-2'-dimethylamino-azobenzene-6'-carboxylic acid.

Claim 33

An indicator as defined by claim 1, said dyestuff being 4-(N-benzyl-N-ethylamino)-3'-(2-hydroxysulfonyloxy-ethylsulfonyl)-azobenzene-6'-carboxylic acid.

Claim 34

An indicator as defined by claim 1, said dyestuff being 4-dimethylamino-3'-(2-hydroxysulfonyloxy-ethylsulfonyl)-azobenzene-6'-carboxylic acid.

Claim 35

An indicator as defined by claim 1, said dyestuff being 4-methylamino-3'-(2-hydroxysulfonyloxy-ethylsulfonyl)-azobenzene-6'-carboxylic acid.

Claim 36

An indicator as defined by claim 1, said dyestuff being 4-ethylamino-5-methyl-3'-(2-hydroxysulfonyloxy-ethylsulfonyl)-azobenzene-6'-carboxylic acid.

Claim 37

An indicator as defined by claim 1, said dyestuff being 4-diethylamino-3'-(2-hydroxysulfonyloxy-ethylsulfonyl)-azobenzene-6'-carboxylic acid.

Claim 38

An indicator as defined by claim 1, said carrier being in the form of a paper.

Claim 39

An indicator as defined by claim 37 wherein said paper is a cellulosic paper.

Claim 40

An indicator as defined by claim 38 said dyestuff being 1-[2-chloro-5-(2-hydroxysulfonyloxy-ethylsulfonyl)-phenylazo]-2-naphthol-3,6-disulfonic acid.

Claim 41

An indicator as defined by claim 38 said dyestuff being 2-(4-hydroxynaphthyl-1-azo)-4-(2-hydroxysulfonyloxy-ethylsulfonyl)-benzenesulfonic acid.

Claim 42

An indicator as defined by claim 38 said dyestuff being 2-[2-nitro-4-(2-hydroxysulfonyloxy-ethylsulfonyl)-phenylazo]-1-naphthol-3,6-disulfonic acid.

Claim 43

An indicator as defined by claim 38 said dyestuff being 1-[2-nitro-4-(2-hydroxysulfonyloxy-ethylsulfonyl)phenylazo]-2-naphthol-7-sulfonic acid.

Claim 44

An indicator as defined by claim 38 said dyestuff being 4-anilino-3'-(2-hydroxysulfonyloxy-ethylsulfonyl)-azobenzene-6'-carboxylic acid.

Claim 45

An indicator as defined by claim 38 said dyestuff being 4-methylamino-4'-(N-methyl-N-[2-(hydroxysulfonyl-oxy)-ethyl]-sulfonamido)-azobenzene-5-sulfonic acid.

Claim 46

An indicator as defined by claim 38 said dyestuff being 4-(N-methyl-N-[2-(hydroxysulfonyloxy)-ethyl]-sulfonamido)-2'-dimethylamino-azobenzene-6'-sulfonic acid.

Claim 47

An indicator as defined by claim 38 said dyestuff being 2-(2,4 -dinitrophenylazo)-6-(N-methyl-N-[2-(hydroxysulfonyloxy)-ethyl]-sulfonamido)-1-naphthol-3-sulfonic acid.

Claim 48

An indicator as defined by claim 38 said dyestuff being 1-[2-nitro-4-(2-hydroxysulfonyloxy-ethylsulfonyl)-phenylazo]-2-naphthol-6,8 disulfonic acid.

Claim 49

An indicator as defined by claim 38 said dyestuff being 2-(2-sulfo-4,6-dinitro-phenylazo)-6-(N-methyl-N-[2-(hydroxysulfonyloxy)-ethyl]-sulfonamido)-1-naphthol-3-sulfonic acid.

Claim 50

An indicator as defined by claim 38 said dyestuff being 4-(N-methyl-N-[2-(hydroxysulfonyloxy)-ethyl]-sulfonamido)-2'-dimethylamino-azobenzene-6'-carboxylic acid.

Claim 51

An indicator as defined by claim 38 said dyestuff being 4-(N-benzyl-N-ethylamino)-3'-(2-hydroxysulfonyloxy-ethylsulfonyl)-azobenzene-6'-carboxylic acid.

Claim 52

An indicator as defined by claim 38 said dyestuff being 4-dimethylamino-3'-(2-hydroxysulfonyloxy-ethylsulfonyl)-azobenzene-6'-carboxylic acid.

Claim 53

An indicator as defined by claim 38 said dyestuff being 4-methylamino-3'-(2-hydroxysulfonyloxy-ethylsulfonyl)-azobenzene-6'-carboxylic acid.

Claim 54

An indicator as defined by claim 38 said dyestuff being 4-ethylamino-5-methyl-3'-(2-hydroxysulfonyloxy-ethylsulfonyl)-azobenzene-6'-carboxylic acid.

Claim 55

An indicator as defined by claim 38 said dyestuff being 4-diethylamino-3'-(2-hydroxysulfonyloxy-ethylsulfonyl)-azobenzene-6'-carboxylic acid.