Antimicrobial cements and cementitious compositions
AssigneeSciessent LLC
InventorsJoseph J. Crudden, Joseph V. Lazzaro, Edward K. Welch, II
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Abstract
Efficient antimicrobial additives are provided comprising a wettable, cake-forming inorganic material having dispersed therein an inorganic or organometallic antimicrobial agent capable of releasing antimicrobial metal ions. These antimicrobial additives are especially effective for use in cements, mortars and cementitious compositions.
Claims36
An antimicrobial additive in the form of discrete particles of a wettable, caked inorganic material of from 20 to 5000 microns, said discrete particles consisting essentially of:
- a) gypsum, gypsum cement, calcium hydroxide, calcium carbonate, chalk clay, Portland cement, kalsomine, or calcite as the matrix phase material having incorporated or dispersed therein
- b) from about 1 to about 50 parts by weight, based on 100 parts by weight of (a), of at least one antimicrobial metal ion-containing inorganic or organometallic antimicrobial agent capable of releasing antimicrobial metal ions in the presence of water in an antimicrobially effective amount;
- and
- c) optionally, colorants, plasticizers, pigments, foaming suppressors, defoaming agents, antifoaming agents, surfactants, wetting agents, residual water, and combinations thereof;
- wherein the antimicrobial metal ion is at least one of silver, copper, zinc, tin, gold, mercury, lead, iron, cobalt, nickel, manganese, arsenic, antimony, bismuth, barium, cadmium, chromium and thallium and the antimicrobial agent is in the form of a salt, an organometallic compound, a water soluble glass containing a source of the antimicrobial metal ion(s), an ion-exchange antimicrobial agent comprising a ceramic carrier particle with ion-exchangeable antimicrobial metal ions, or combinations thereof;
- provided that when the antimicrobial agent is in the form of discrete particles dispersed in (a), the particle size of the antimicrobial agent is no more than one-tenth that of the particle size of the antimicrobial additive;
- wherein said antimicrobial additive particles are capable of maintaining, for the most part, their particle form while being incorporated into cements, mortars and cementitious or hybrid cementitious compositions.
A method of making an antimicrobial additive in the form of discrete particles of a wettable, caked inorganic material of from 20 microns up to one inch which particles are capable of maintaining, for the most part, their particle form while being incorporated into cements, mortars, and cementitious and hybrid cementitious compositions, said method comprising the steps of:
- i) forming a slurry of an inorganic wettable cake forming composition consisting essentially of (a) gypsum, gypsum cement, calcium hydroxide, calcium carbonate, chalk, clay, Portland cement, kalsomine, or calcite as the matrix forming material;
- (b) from about 1 to about 50 parts by weight, based on 100 parts by weight of (a), of at least one antimicrobial metal ion-containing inorganic or organometallic antimicrobial agent capable of releasing antimicrobial metal ions in the presence of water in an antimicrobially effective amount;
- and (c) optionally, colorants, plasticizers, pigments, foaming suppressors, antifoaming agents, defoaming agents, surfactants, wetting agents, residual water, or combinations thereof;
- wherein the antimicrobial metal ion is at least one of silver, copper, zinc, tin, gold, mercury, lead, iron, cobalt, nickel, manganese, arsenic, antimony, bismuth, barium, cadmium, chromium and thallium and the antimicrobial agent is in the form of a salt, an organometallic compound, a water soluble glass containing a source of the antimicrobial metal ion(s), an ion-exchange antimicrobial agent comprising a ceramic carrier particle with ion-exchangeable antimicrobial metal ions, or combinations thereof:
- provided that when the antimicrobial agent is not soluble in the slurry, its particle size in no more than one tenth that of the particles to be formed by the method;
- ii) allowing the composition to cure or harden to form a cake;
- iii) breaking, crushing and/or grinding the cake to form discrete particles thereof;
- and
- iv) either removing those particles exceeding a maximum particle size or isolating those particles of a set particle size or range of particle sizes, or both.
Dependencies are inferred from the claim text.