COMPOSITION OF MICROPARTICLES CONTAINING ORGANIC IR RADIATION ABSORBING PIGMENT Russian patent published in 2023 - IPC C09B67/02 C09B67/08 C09D5/32 C09D11/37 C09D11/103 D21H21/40 

FIELD: microparticles.

SUBSTANCE: group of inventions relates to a microparticle-based pigment composition of an organic IR-absorbing pigment, which is a polyunsaturated organic compound or an organometallic compound having a main absorption maximum in the range from 750 to 1,100 nm, where the microparticles of the pigment composition contain an organic IR-absorbing pigment in the form of solid particles surrounded by or included in an aminoplastic polymer, which is a polycondensation product of one or more amino compounds and one or more aldehydes, wherein the microparticle-based pigment composition is characterized by a particle size distribution by volume, as determined by static light scattering, having an average by volume D value (4.3) in the range from 1.0 to 15.0 μm, where the amount of aminoplastic polymer in the microparticle composition is from 15 to 50 wt.%, based on the total mass of aminoplastic polymer and organic IR-absorbing pigment and wherein the amount of the organic IR-absorbing pigment is from 50 to 85% by weight based on the total weight of the aminoplastic polymer and the organic IR-absorbing pigment, wherein the aminoplastic polymer is a melamine-formaldehyde resin, also refers to a method for producing a microparticle-based pigment composition which includes the following steps: i) providing an aqueous suspension of solid organic IR-absorbing pigment particles that also contain an amino-based precondensate of one or more amino compounds and one or more aldehydes; ii) carrying out the polycondensation of an aminoplast-based precondensate in an aqueous suspension of a solid organic IR-absorbing pigment in the presence of at least one surfactant, also relates to the use of a microparticle composition to obtain a printing ink composition for security printing, also relates to a printing ink composition containing a microparticle-based pigment composition and a binder also relates to a method of producing a security feature or a security document that includes applying a printing ink composition to a substrate through a printing process, and refers to a security document containing a substrate onto which the printing ink composition has been applied through printing process.

EFFECT: group of inventions provides microparticles having both good absorption in the lower infrared region (NIR) and provides good stability against degradation in printing inks, and also provides microparticles containing IR absorbing pigment that can be used in small quantities compared to pigments from the prior art and through which also good stability of the IR absorbing pigment contained therein is achieved.

17 cl, 1 dwg, 1 tbl, 13 ex