Cured compositions containing fine magnetic particles and a process for preparing same and their use
OwnerJingjing Xu, Charles Molnar +5inventors
InventorsJingjing Xu, Charles Molnar, Shekhar Subramoney, Michael Crawford, John Gergely, Lu Zhang, Edwin Marston
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Abstract
The present invention is a dispersion composition comprising (1) a curable mixture of monomers, oligomers, or a combination thereof; and (2) superparamagnetic particles dispersed in the mixture of part (1) and a method for preparing such superparamagnetic particles. The composition of the present invention can be useful as a tool for detecting and/or deterring theft, counterfeiting, or the like in commercial transactions.
Claims29
A composition which is a dispersion comprising:
- (1) a curable mixture comprising (a) monomers, or (b) oligomers, or (c) a combination thereof, wherein the mixture can be cured or polymerized using a curing or polymerizing agent;
- (2) superparamagnetic particles dispersed in the mixture of part (1), wherein the superparamagnetic particles have a diameter of less than 1 micrometer;
- (3) at least one curing agent or polymerization agent selected from photoinitiators, radiation initiators, chemical initiators, thermally activated initiators optionally present in an amount of up to about 2 wt %;
- (4) one or more components, optionally present in any effective amount, selected from the group consisting of:
- (i) viscosity modifiers (up to about 40 wt %), (ii) other taggants, and/or (iii) solvents.
A film having dispersed therein, superparamagnetic particles having a particle size of less than about 1 micrometer.
An article comprising a film or a coating wherein the film or coating has dispersed therein superparamagnetic particles having a diameter of less than 1 micrometer.
A method of applying a film having superparamagnetic particles dispersed therein comprising the step of printing onto a substrate, a dispersion comprising:
- (1) a curable mixture comprising (a) monomers, or (b) oligomers, or (c) a combination thereof, wherein the mixture can be cured or polymerized using a curing or polymerizing agent;
- (2) superparamagnetic particles dispersed in the mixture of part (1), wherein the superparamagnetic particles have a diameter of less than 1 micrometer;
- (3) optionally at least one curing agent or polymerization agent selected from photoinitiators, radiation initiators, chemical initiators, thermally activated initiators, present in an amount of up to about 2 wt %;
- (4) one or more components, optionally present in any effective amount, selected from the group consisting of:
- (i) viscosity modifiers (up to about 40 wt %), (ii) other taggants, and/or (iii) solvents.
A method of preparing a substrate comprising a superparamagnetic film comprising the steps of:
- (1) applying a superparamagnetic dispersion to a substrate;
- and (2) curing the dispersion on the surface of the substrate to form the superparamagnetic film, wherein the film comprises superparamagnetic particles having a diameter of less than about 1 micrometer.
A method for preparing a substrate comprising a superparamagnetic film comprising the steps of:
- (1) curing a curable dispersion comprising (a) either of (i) a mixture of monomers, (ii) a mixture of oligomers, or (iii) a mixture of monomers and a mixture of oligomers, wherein the mixture is cured using a curing agent;
- (b) superparamagnetic particles dispersed in the mixture of part (a), wherein the superparamagnetic particles have a diameter of less than 1 micrometer;
- (c) optionally at least one curing agent or polymerization agent selected from photoinitiators, radiation initiators, chemical initiators, thermally activated initiators;
- and (d) optionally one or more viscosity modifiers, other taggants, and solvents;
- and (2) applying the film to the substrate.
Dependencies are inferred from the claim text.