Azo dye compound, ink containing the same, and recording method and instrument using the ink

An ink comprising a recording agent and a liquid medium for dissolving or dispersing the recording agent therein, wherein the recording agent comprises a monoazo dye compound having a structural unit represented by the following formula in its molecule:

• --X--Y--(R.sub.1)(R.sub.2)(R.sub.3).sub.k [I]
• wherein Y is a 6-membered ring containing 2 or 3 nitrogen atoms, X is a linking group for bonding a main body of the dye molecule to Y, R.sub.1 is the first amino acid residue, R.sub.2 is an atomic group selected from the following group A, R.sub.3 is another atomic group selected from the following group BB, and k is a number of 0 or 1:
• Group A:
• H, OH, NH.sub.2, CN, .dbd.O and the second amino acid residue;
• Group BB:
• H, OH, NH.sub.2, CN and .dbd.O,
• the first and second amino acid residues being identical with or different from each other.

A disazo dye compound represented by the following general formula:

• ##STR46## wherein Y is a 6-membered ring containing 2 or 3 nitrogen atoms, X is a linking group for bonding a main body of the dye molecule to Y, R.sub.6 is --N(H).sub.m (CH.sub.2 CH.sub.2 OH).sub.2-m, in which m is a number of 0 or 1, R.sub.7 is an atomic group selected from the following group FF, R.sub.8 is another atomic group selected from the following group G, M is Na, K or ammonium, and i, j and k are individually a number of 0 or 1:
• Group FF:
• H, OH, NH.sub.2, CN, .dbd.O and --N(H).sub.n (CH.sub.2 CH.sub.2 OH).sub.2-n, in which n is a number of 0 or 1;
• Group G:
• H, OH, NH.sub.2, CN and .dbd.O.

An ink comprising a recording agent and a liquid medium for dissolving or dispersing the recording agent therein, wherein the recording agent comprises a disazo dye represented by the following general formula:

• ##STR49## wherein Y is a 6-membered ring containing 2 or 3 nitrogen atoms, X is a linking group for bonding a main body of the dye molecule to Y, R.sub.6 is --N(H).sub.m (CH.sub.2 CH.sub.2 OH).sub.2-m, in which m is a number of 0 or 1, R.sub.7 is an atomic group selected from the following group FF, R.sub.8 is another atomic group selected from the following group G, M is Na, K or ammonium, and i, j and k are individually a number of 0 or 1:
• Group FF:
• H, OH, NH.sub.2, CN, .dbd.O and --N(H).sub.n (CH.sub.2 CH.sub.2 OH).sub.2-n, in which n is a number of 0 or 1;
• Group G:
• H, OH, NH.sub.2, CN and .dbd.O.

A trisazo dye compound represented by the following general formula:

• ##STR52## wherein Q.sub.1 is a p-phenylene group or 1,4-naphthylene group, each of which is unsubstituted or substituted by a group selected from the group consisting of SO.sub.3 M, COOM, CH.sub.3, OCH.sub.3, NHCONH.sub.2 and NHCOCH.sub.3, Q.sub.2 is a p-phenylene group unsubstituted or substituted by a group selected from the group consisting of COOM, CH.sub.3, OCH.sub.3, NHCONH.sub.2 and NHCOCH.sub.3, Y is a 6-membered ring containing 2 or 3 nitrogen atoms, X is a linking group for bonding a main body of the dye molecule to Y, R.sub.9 is --N(H).sub.m (CH.sub.2 CH.sub.2 OH).sub.2-m, in which m is a number of 0 or 1, R.sub.10 is an atomic group selected from the following group J, R.sub.11 is another atomic group selected from the following group KK, M is Na, K or ammonium, and k and l are individually a number of 0 or 1:
• Group J:
• H, OH, NH.sub.2, CN, .dbd.O and --N(H).sub.n (CH.sub.2 CH.sub.2 OH).sub.2-n, in which n is a number of 0 or 1;
• Group KK:
• H, OH, NH.sub.2, CN and .dbd.O.

An ink comprising a recording agent and a liquid medium for dissolving or dispersing the recording agent therein, wherein the recording agent comprises a trisazo dye represented by the following general formula:

• ##STR55## wherein Q.sub.1 is a p-phenylene group or 1,4-naphthylene group, each of which is unsubstituted or substituted by a group selected from the group consisting of SO.sub.3 M, COOM, CH.sub.3, OCH.sub.3, NHCONH.sub.2 and NHCOCH.sub.3, Q.sub.2 is a p-phenylene group unsubstituted or substituted by a group selected from the group consisting of COOM, CH.sub.3, OCH.sub.3, NHCONH.sub.2 and NHCOCH.sub.3, Y is a 6-membered ring containing 2 or 3 nitrogen atoms, X is a linking group for bonding a main body of the dye molecule to Y, R.sub.9 is --N(H).sub.m (CH.sub.2 CH.sub.2 OH).sub.2-m, in which m is a number of 0 or 1, R.sub.10 is an atomic group selected from the following group J, R.sub.11 is another atomic group selected from the following group KK, M is Na, K or ammonium, and k and l are individually a number of 0 or 1:
• Group J:
• H, OH, NH.sub.2, CN, .dbd.O and --N(H).sub.n (CH.sub.2 CH.sub.2 OH).sub.2-n, in which n is a number of 0 or 1;
• Group KK:
• H, OH, NH.sub.2, CN and .dbd.O.