Composition for production of coatings comprising improved phosphors

A composition for the production of coatings having

• an antimicrobial property, the composition comprising:
• at least one film-forming polymer,
• optionally, at least one additive,
• optionally, at least one curing agent, and
• at least one up-conversion phosphor of the general formula (I)
• A1-x-y-zB*yB2SiO4:Ln1x,Ln2z, (I)
• wherein
• x=0.0001-0.0500;
• z=0.0000 or z=0.0001 to 0.3000 with the proviso that:
• y=x+z;
• A is selected from the group consisting of Mg, Ca, Sr, and Ba;
• B is selected from the group consisting of Li, Na, K, Rb, and Cs;
• B* is selected from the group consisting of Li, Na, and K;
• Ln1 is selected from the group consisting of praseodymium (Pr), erbium (Er), and neodymium (Nd);
• Ln2 is gadolinium (Gd);
• and
• wherein the at least one up-conversion phosphor has been prepared using at least one halogen-containing flux.