US2006169431A1PendingUtilityA1

Enhanced efficacy of fungicides in paper and paperboard

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Individually held — no corporate assignee on recordPriority: Jan 5, 2005Filed: Jan 5, 2006Published: Aug 3, 2006
Est. expiryJan 5, 2025(expired)· nominal 20-yr term from priority
Inventors:Thomas Westley MarksGary MeloniJudy G. Lazonby
D21H 17/55D21H 17/56D21H 17/36D21H 17/44D21H 27/20D21H 17/375D21H 21/36D21H 17/29D21H 23/04D21H 17/37
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Claims

Abstract

The invention is a method for making a fungal-resistant sheet of paper or paperboard for use in building materials. The method comprises adding a hydrophobic fungicide with a solubility in water of less that 0.3 g/L at 25° C. to a paper slurry during manufacture of the paper or paperboard, and processing the paper slurry in a paper machine to create a sheet. Addition of a second process additive, especially a cationic fixative, synergistically improves the efficacy of the hydrophobic fungicide. A preferred fungicide is diiodomethyl-p-tolylsulfone.

Claims

exact text as granted — not AI-modified
1 . A method for making a fungal-resistant paper sheet for use in building materials comprising adding a hydrophobic fungicide with a solubility in water of less than 0.3 g/L at 25° C. and a cationic fixative to a paper slurry during manufacture of the paper or paperboard, and processing the paper slurry in a paper machine to create a sheet.  
   
   
       2 . The method of  claim 1  wherein the hydrophobic fungicide is selected from the group consisting of diiodomethyl-p-tolylsulfone (DIMTS), zinc pyrithione, thiabendazole, 3-iodo-2-propynyl butylcarbamate, dichloro-octyliosothiazolinone, o-phenylphenol, bromonitrostyrene, and 2-(thiocyanomethylthio) benzothiazole.  
   
   
       3 . The method of  claim 1  wherein the hydrophobic fungicide is diiodomethyl-p-tolylsulfone.  
   
   
       4 . The method of making fungal-resistant paper sheet according to  claim 1 , further comprising processing the sheet into pressed paper.  
   
   
       5 . The method of making fungal-resistant paper sheet according to  claim 1 , further comprising processing the sheet into multi-ply paperboard.  
   
   
       6 . The method of making fungal-resistant paper sheet according to  claim 1  wherein the hydrophobic fungicide is added by wet end application to the pulp slurry before the cationic fixative is added to the pulp slurry.  
   
   
       7 . The method of making fungal-resistant paper sheet according to  claim 1  wherein the hydrophobic fungicide is added by wet end application to the pulp slurry after the cationic fixative is added to the pulp slurry.  
   
   
       8 . The method of making fungal-resistant paper sheet according to  claim 1  the hydrophobic fungicide is added by wet end application to the pulp slurry at the same time that the cationic fixative is added to the pulp slurry.  
   
   
       9 . The method of  claim 7  where the hydrophobic fungicide and the cationic fixative are mixed together to form a pre-mix and the pre-mix is added by wet end application to the pulp slurry.  
   
   
       10 . The method of making a fungal-resistant paper sheet according to  claim 1  to  3 , wherein the cationic fixative is selected from cationic homopolymers and copolymers of polyacrylamides, polyamines, polyDADMACs, polyguanidines, polyethyleneimines, cellulosic ethers, starches, aluminum-based coagulants, iron-based coagulants, modified clays, modified talcs, microparticle silica systems, and combinations thereof.  
   
   
       11 . The method of making fungal-resistant paper sheet according to  claim 1  to  3 , wherein the cationic fixative is a polyamine.  
   
   
       12 . The method of making fungal-resistant paper sheet according to  claim 1  to  3 , wherein the weight ratio of cationic fixative to fungicide is from 1:35 to 15:1.  
   
   
       13 . The method of making fungal-resistant paper sheet according to  claim 1  to  3 , wherein the weight ratio of cationic fixative to fungicide is from 1:35 to 2.5:1.  
   
   
       14 . The method of making fungal-resistant paper sheet according to  claim 1  to  3 , further comprising treating the sheet to provide moisture resistance and/or strength enhancement.  
   
   
       15 . The method of making a fungal resistant paper sheet of  claim 1  to  3 , further comprising adding a second antifungal material either to the paper slurry or to the finished sheet, by coating as neat product, or a formulation.  
   
   
       16 . A fungal-resistant sheet of paper or paperboard made according to the method of  claim 1  to  3 , where the hydrophobic fungicide is present in an amount equal to at least 0.02 pounds per ton of dry fiber present in the sheet.  
   
   
       17 . A fungal-resistant sheet of paper or paperboard made according to the method of  claim 3 , where the diiodomethyl-p-tolylsulfone is present in an amount between about 2.0 and 10.0 pounds per ton of dry fiber present in the sheet.  
   
   
       18 . A fungal-resistant sheet of paper or paperboard made according to the method of  claim 3 , where the diiodomethyl-p-tolylsulfone is present in an amount between about 2.0 and 3.2 pounds per ton of dry fiber present in the sheet.  
   
   
       19 . A fungal-resistant sheet made by the method of  claim 1  to  3 , wherein both the cationic fixative and fungicide do not substantially change the mechanical properties or quality of the paper.  
   
   
       20 . A fungal-resistant sheet made by the method of  claim 1  to  3  that tests as at least “moderately fungus resistant” according to TAPPI method T-487 for paper and paperboard after 2 weeks of testing.  
   
   
       21 . A fungal-resistant sheet made by the method of  claim 1  to  3  that tests as “fungus resistant” according to TAPPI method T-487 for paper and paperboard after 3 weeks of testing.  
   
   
       22 . A fungal-resistant sheet made by the method of  claim 1  that has 30% or less fungal growth after 7 days of testing under the conditions of ASTM method G-21.  
   
   
       23 . A fungal-resistant sheet made by the method of  claim 1  that has 30% or less fungal growth after 4 weeks of testing under the conditions of ASTM method G-21.  
   
   
       24 . A fungal-resistant sheet made by the method of  claim 1  that receives a rating of 7 to 10 in ASTM D 3273.  
   
   
       25 . A fungal-resistant sheet made by the method of  claim 1  to  3  further comprising an antifungal surface treatment.  
   
   
       26 . A finished gypsum board comprising a fungal-resistant sheet made by the method of  claim 1  to  3  wherein the gypsum board passes ASTM D3273 with a rating of 7 to 10 inclusive.

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