IMPROVEMENTS IN INK FORMULATIONS COMPRISING GALLIUM NAPHTHALOCYANINES

摘要

There is provided an aqueous formulation comprising an IR-absorbing naphthalocyanine dye of formula (II): or a salt form thereof, wherein: M is Ga(A<SUP>1</SUP>); A<SUP>1</SUP> is an axial ligand selected from -OH, halogen, -OR<SUP>3</SUP>, -OC(O)R<SUP>4</SUP> or -O(CH<SUB>2</SUB>CH<SUB>2</SUB>O)<SUB>e</SUB>R<SUP>6</SUP> wherein e is an integer from 2 to 10 and R<SUP>6</SUP> is H, C<SUB>1-8</SUB> alkyl or C(O)C<SUB>1-8</SUB> alkyl; R<SUP>1</SUP> and R<SUP>2</SUP> may be the same or different and are selected from hydrogen or C<SUB>1-2</SUB> alkoxy; R<SUP>3</SUP> is selected from C<SUB>1-2</SUB> alkyl, C<SUB>5-I2</SUB> aryl, C<SUB>5-12</SUB> arylalkyl or Si(R<SUP>x</SUP>)(R<SUP>y</SUP>)(R<SUP>z</SUP>); R<SUP>4</SUP> is selected from C<SUB>1-12</SUB> alkyl, C<SUB>5-12</SUB> aryl or C<SUB>5-12</SUB> arylalkyl; and R<SUP>x</SUP>, R<SUP>y</SUP> and R<SUP>z</SUP> may be the same or different and are selected from C<SUB>1-12</SUB> alkyl, C<SUB>5-12</SUB> aryl, C<SUB>5-12</SUB> arylalkyl, C<SUB>1-12</SUB> alkoxy, C<SUB>1-12</SUB> aryloxy or C<SUB>5-12</SUB> arylalkoxy. The formulation has a pH in the range of 3,5 to 7 and is particularly suitable for use as an IR- absorbing inkjet ink, providing compatibility with known CMYK, inks together with an optimally red-shifted ?<SUB>max</SUB>