Antimicrobial composite material

A composite material comprising:

• a) activated and ground sodium hexametaphosphate frit particles obtainable by means of a thermal activation method comprising the steps of:
• i) heating a sodium hexametaphosphate salt until it melts such that a molten sodium hexametaphosphate salt is obtained;
• ii) abruptly cooling the molten sodium hexametaphosphate salt obtained in step (i) in a dry medium to obtain activated sodium hexametaphosphate frit particles;
• and
• iii) grinding the activated sodium hexametaphosphate frit particles obtained in step (ii) to obtain activated and ground sodium hexametaphosphate frit particles;
• and
• b) a polymer matrix;
• wherein said activated and ground sodium hexametaphosphate frit particles are embedded in said polymer matrix.

Activated and ground sodium hexametaphosphate frit particles obtainable by means of a thermal activation method comprising the steps of:

• i) heating a sodium hexametaphosphate salt until it melts such that a molten sodium hexametaphosphate salt is obtained;
• ii) abruptly cooling the molten sodium hexametaphosphate salt obtained in step (i) in a dry medium to obtain activated sodium hexametaphosphate frit particles;
• and
• iii) grinding the activated sodium hexametaphosphate frit particles obtained in step (ii) to obtain activated and ground sodium hexametaphosphate frit particles.