Methods for preparing curable pigment inkjet ink sets

1. A curable pigment inkjet ink set comprising:

a cyan inkjet ink;

a yellow inkjet ink; and

a magenta inkjet ink; wherein

the yellow inkjet ink having ABS(Y) 500-530 <5 and ABS(Y) 400-500 >60 includes one or more yellow pigments;

the cyan inkjet ink includes one or more β-copper phthalocyanine pigments;

the magenta inkjet ink contains a mixed crystal such that a first quinacridone and a second quinacridone enter into a same crystal lattice in a ratio of the first quinacridone over the second quinacridone and such that ABS(M) 500-530 >20 and ABS(M) 500-600 >60;

ABS(Y) 500-530 represents an absorbance of the yellow inkjet ink between 500 and 530 nm in a normalized absorption spectrum of the yellow ink;

ABS(M) 500-530 represents an absorbance of the magenta inkjet ink between 500 and 530 nm in a normalized absorption spectrum of the magenta ink;

ABS(Y) 400-500 represents an absorbance of the yellow inkjet ink between 400 and 500 nm in a normalized absorption spectrum of the yellow ink;

ABS(M) 500-600 represents an absorbance of the magenta inkjet ink between 500 and 600 nm in a normalized absorption spectrum of the magenta ink;

ABS(X) wL1-WL2 represents a peak area between wavelengths WL 1 and WL 2 calculated by summation of the normalized absorbance values in the range WL 1 to WL 2 which are obtained by multiplying the absorbance values at each wavelength in the range from 380 nm to 850 nm by the reciprocal value of the maximum absorbance A max in the range of 380 nm to 850 nm using a spectrophotometer with an interval of 1 nm on the ink X diluted in ethyl acetate to a pigment concentration of 40 ppm;

the cyan, yellow, and magenta inkjet inks of the curable pigment inkjet ink set are curable by exposure to actinic radiation and/or electron beam curing; and

each of the cyan, yellow, and magenta inkjet inks includes at least a pigment, a dispersant, and a polymerizable compound.

2. The curable pigment inkjet ink set according to claim 1 , wherein the first quinacridone is C.I. Pigment Violet 19.

3. The curable pigment inkjet ink set according to claim 2 , wherein the second quinacridone is C.I. Pigment Red 202.

4. The curable pigment inkjet ink set according to claim 3 , wherein the yellow inkjet ink comprises C.I. Pigment Yellow 150.

5. The curable pigment inkjet ink set according to claim 2 , wherein the mixed crystal includes C.I. Pigment Violet 19 in an amount between 75% and 95% as measured by Probe-MS.

6. The curable pigment inkjet ink set according to claim 5 , wherein the mixed crystal includes C.I. Pigment Violet 19 in an amount between 80% and 90% as measured by Probe-MS.

7. The curable pigment inkjet ink set according claim 4 , further comprising C.I. Pigment Blue 15:4.

8. The curable pigment inkjet ink set according to claim 7 , wherein the magenta inkjet ink includes a dispersion synergist.

9. The curable pigment inkjet ink set according to claim 8 , further comprising a black inkjet ink.

10. The curable pigment inkjet ink set according to claim 9 , wherein the black inkjet ink includes a carbon black pigment and at least one non-black pigment having an absorbance maximum between 500 nm and 800 nm.

11. The curable pigment inkjet ink set according to claim 10 , wherein the at least one non-black pigment is a copper phthalocyanine pigment.

12. A method for preparing a curable pigment inkjet ink set as defined by claim 1 , comprising the step of:

preparing the magenta inkjet ink by milling the mixed crystal such that the first quinacridone and the second quinacridone enter into the same crystal lattice; wherein the first quinacridone is C.I. Pigment Violet 19.