Radiation-curable compositions of pigment violet 23 with improved removability from surfaces, method of making a radiation-curable composition and ink containing a radiation-curable composition

A method for producing a radiation-curable composition, which comprises the steps of:

• i) providing at least one Pigment Violet 23 containing at least one functional group of the formula (I):
• —X-E (I)
• where:
• X is a bridging group selected from phenylene or methylenephenylene;
• and
• E is a polar molecule radical which is bonded to the Pigment Violet 23 via the bridging group X;
• wherein E in the formula (I) is
• (Z)m(A)n
• where:
• Z is at least one polar functional group selected from at least one sulfonate radical, carboxylate radical or phosphonate radical;
• A is a short-chain apolar molecule radical or a countercation selected from at least one proton, alkali metal cation, alkaline earth metal cation or an ammonium ion;
• m is 1 or 2;
• and
• n is 1, 2, 3 or 4;
• and
• ii) dispersing the at least one Pigment Violet 23 in a nonaqueous dispersion medium, using at least one dispersant.

An ink for inkjet printing, containing:

• a radiation-curable composition, containing:
• a) at least one Pigment Violet 23, containing at least one functional group of formula (I)
• —X-E (I)
• where:
• X is a bridging group selected from phenylene or methylenephenylene;
• and
• E is a polar molecule radical which is bonded to the Pigment Violet 23 via the bridging group X;
• wherein E is
• (Z)m(A)n
• where:
• Z is at least one polar functional group selected from at least one sulfonate radical, carboxylate radical or phosphonate radical;
• A is a short-chain apolar molecule radical or a countercation selected from at least one proton, alkali metal cation, alkaline earth metal cation or an ammonium ion;
• m is 1 or 2;
• and
• n is 1, 2, 3 or 4;
• b) at least one dispersant;
• and
• C) a nonaqueous dispersion medium.