Treatment Composition Containing A Mold Inhibiting Agent and A Water Repellent Having Reduced Foaming Properties

Abstract

The present disclosure is generally directed to a mold inhibiting composition. The mold inhibiting composition can be used to treat various different substrates, including building material products, such as facing layers for wallboard. In general, any suitable paper product may be treated with the composition. The composition contains a mold inhibiting agent in combination with a defoamer. The mold inhibiting agent may comprise a pyrithione. The defoamer, on the other hand, may comprise an oil based defoamer containing metal oxide particles, such as silica particles. The mold inhibiting composition can be combined with a water repellent and applied to a substrate without excessive amounts of foam or froth being formed. The defoamer is selected so as to not interfere with the resulting water absorption properties of the product.

What is claimed: 
     
         1 . A building material product comprising:
 a core comprising gypsum, the core including a first face and a second and opposite face;   a first facing layer adhered to the first face and a second facing layer adhered to the second face of the core, each of the first and second facing layers comprising a paper layer;   a water repellent and mold inhibiting composition applied to at least one of the facing layers, the water repellent and mold inhibiting composition comprising:
 a water repellent agent; 
 a mold inhibiting agent; and 
 a defoamer, the defoamer comprising an oil carrier and a defoaming agent, the defoamer being present on the facing layer in an amount greater than about 5 grams per MSF. 
   
     
     
         2 . A building material product as defined in  claim 1 , wherein the defoamer is present on the facing layer in an amount of from about 10 grams per MSF to about 50 grams per MSF. 
     
     
         3 . A building material product as defined in  claim 1 , wherein the oil carrier comprises a hydrocarbon oil. 
     
     
         4 . A building material product as defined in  claim 1 , wherein the oil carrier comprises mineral oil, vegetable oil, or a white oil. 
     
     
         5 . A building material product as defined in  claim 1 , wherein the defoaming agent comprises hydrophobic silica particles. 
     
     
         6 . A building material product as defined in  claim 1 , wherein the water repellent and mold inhibiting composition further comprises a wax. 
     
     
         7 . A building material product as defined in  claim 6 , wherein the wax comprises a stearamide wax, a paraffin wax, an ester wax, or a fatty alcohol wax. 
     
     
         8 . A building material product as defined in  claim 1 , wherein the mold inhibiting agent comprises a pyrithione. 
     
     
         9 . A building material product as defined in  claim 8 , wherein the pyrithione comprises zinc pyrithione, the pyrithione being present in the building material product as particles, and wherein at least 90% of the zinc pyrithione particles have a particle size of less than 2 micron. 
     
     
         10 . A building material product as defined in  claim 1 , wherein the water repellent and mold inhibiting composition further contains zinc oxide particles. 
     
     
         11 . A building material product as defined in  claim 1 , wherein the mold inhibiting agent comprises sodium pyrithione 
     
     
         12 . A building material product as defined in  claim 1 , wherein the water repellent agent comprises a silicone copolymer. 
     
     
         13 . A building material product as defined in  claim 1 , wherein the mold inhibiting agent is also present within the core. 
     
     
         14 . A building material product as defined in  claim 1 , wherein both the first facing layer and the second facing layer have been treated with the water repellent and mold inhibiting composition. 
     
     
         15 . A building material product as defined in  claim 1 , wherein the mold inhibiting agent is present in the facing layer at a concentration of from about 50 ppm to about 10,000 ppm. 
     
     
         16 . A building material product as defined in  claim 1 , wherein the facing layer treated with the water repellent and mold inhibiting composition has a basis weight of from about 38 lbs per MSF to about 50 lbs per MSF. 
     
     
         17 . A mold resistant paper product comprising:
 a paper layer; and   a water repellent and mold inhibiting composition applied to the paper layer, the water repellent and mold inhibiting composition comprising;   a water repellent agent;   a mold inhibiting composition comprising a pyrithione; and   a defoamer, the defoamer comprising an oil carrier and a defoaming agent, the oil carrier comprising a mineral oil, a vegetable oil, or a white oil, the defoamer further comprising a defoaming agent, the defoaming agent comprising silica particles, the defoamer being present on the paper layer in an amount greater than about 5 grams per MSF, and wherein the paper product has a Cobb water absorption value of less than about 100 grams per m 2 .   
     
     
         18 . A paper product as defined in  claim 17 , wherein the water repellent and mold inhibiting composition further comprises a wax. 
     
     
         19 . A mold inhibiting composition for use in paper products comprising;
 a mold inhibiting agent and a defoamer, the defoamer comprising an oil carrier and a defoaming agent, the defoaming agent being present in the composition in an amount greater than about 0.1% by weight.   
     
     
         20 . A mold inhibiting composition as defined in  claim 19 , wherein the mold inhibiting agent comprises zinc pyrithione, the mold inhibiting composition further containing zinc oxide particles. 
     
     
         21 . A process for producing a paper with mold and moisture inhibiting properties comprising:
 forming a paper web from an aqueous suspension of pulp fibers;   applying to a side of the paper web a water repellent and mold-inhibiting composition, the water repellent and mold-inhibiting composition comprising:
 a water repellent dispersion containing a water repellent agent, the water repellent dispersion being present in the water repellent and mold inhibiting composition in an amount from about 3% to about 10% by weight; 
 a mold inhibiting composition comprising a mold inhibiting agent and a defoamer, the defoamer comprising an oil carrier and a defoaming agent, the mold inhibiting composition being present in the water repellent and mold inhibiting composition in an amount from about 7% to about 20% by weight, the defoamer being present in the water repellent and mold inhibiting agent in an amount of at least about 0.1% by weight; and 
 water; and 
 thereafter drying the paper web to form a paper product. 
   
     
     
         22 . A process as defined in  claim 21 , further comprising the step of laminating the paper product to a core comprising gypsum to form a dry wall product. 
     
     
         23 . A process as defined in  claim 21 , wherein the surface of the paper web treated with the water repellent and mold inhibiting composition has a Cobb water absorption value of less than about 100 grams per m 2 .