Copper phthalocyanine compound and aqueous ink composition comprising the same

DETAILED DESCRIPTION OF THE INVENTION Specific examples of the alkoxypropylamino group of the formula: --NHCH.
sub.
2 CH.
sub.
2 CH.
sub.
2 OR.
sub.
1 (II) wherein R.
sub.
1 is the same as defined above contained in the copper phthalocyanine compound (I) are propoxypropylamino, butoxypropylamino, hexyloxypropylamino, 2-ethylhexyloxypropylamino, lauryloxypropylamino, stearyloxypropylamino and the like.
Specific examples of the amino group of the formula: --NR.
sub.
2 R.
sub.
3 (III) wherein R.
sub.
2 and R.
sub.
3 are the same as defined above are amino, ethanolamino and diethanolamino.
Specific examples of alkali metal represented by the residue X in the formula (I) are sodium, potassium and lithium.
When the group R.
sub.
1 has less than 3 carbon atoms, a copper phthalocyanine compound has a too large solubility in water and is inferior in affinity to the wetting agent.
Therefore, it causes clogging of the nozzle, and the water resistance of the recorded image is deteriorated.
When the group R.
sub.
1 has more than 18 carbon atoms, a copper phthalocyanine compound is inferior in affinity to the wetting agent and water so that a larger amount of the wetting agent is required to prepare the ink composition.
Yet, the image density is not increased, and almost all the properties such as storage stability and an anti-nozzle clogging property are not satisfactory.
In the compound of the formula (I), "a" should be 1 or 2 to increase affinity of the compound to the wetting agent and water resistance of the recorded image.
"b" may be 0 (zero) although the copper phthalocyanine compound (I) wherein "b" is 1 or 2 has better affinity to glycols and the like.
When "c" is 0 (zero), the compound (I) has poor affinity to water.
In order to compromise the affinity of the compound (I) to the wetting agent as well as water and water resistance of the recorded image, "a", "b" and "c" should satisfy the equation: 2.
ltoreq.
a+b+c.
ltoreq.
4.
The copper phthalocyanine compound (I) may be prepared, for example, by chlorosulfonating copper phthalocyanine with thionyl chloride at a temperature of 60