Greaseproof paper with lower content of fluorochemicals

Abstract

Methods for making and using aqueous dispersions for imparting grease/oil resistance to paper, paperboard and cellulose fiber products generally are provided. In particular, there are provided aqueous colloidal dispersions comprising nanoparticles of at least one colloidal clay and an aqueous fluorochemical, which can be applied to, on, or in paper, paperboard and cellulose fiber products. The paper and products that have been modified using these aqueous dispersions have good resistance to oil and grease penetration with lower overall amounts of aqueous fluorochemicals being required. Additional methods for imparting grease/oil resistance to paper, paperboard and cellulose fiber products generally are provided. In particular, there is provided a process for improving the oil and grease resistance of a cellulose fiber material, the process comprising: a) applying a pretreatment composition comprising a cationic polymer to a cellulose fiber material in a size press to form a pretreated cellulose substrate; b) drying the pretreated cellulose substrate; and c) applying a fluorochemical composition to the dry pretreated cellulose substrate to form an oil-repellent cellulose fiber material.

We claim: 
     
         1 . A process for improving the oil and grease resistance of a cellulose fiber material, the process comprising:
 forming an aqueous dispersion comprising at least one inorganic nanoparticle component and at least one fluorochemical; and   contacting a cellulose fiber material with the aqueous dispersion to form an oil-repellent cellulose fiber material.   
     
     
         2 . The process of  claim 1 , wherein the aqueous dispersion further comprises a cationic polymer selected from a polyamine, a poly-vinyl amine, a polyethylene imine (PEI), a polyamidoamine, a polyamidoamine epichlorohydrin (PAE), a polyacrylamide, a starch, a prepolymer derived from condensation of adipic acid and diethylenetriamine (DETA); and combinations thereof. 
     
     
         3 . The process of  claim 1 , wherein the aqueous dispersion further comprises a film-forming polymer selected from hemicellulose, carboxymethyl cellulose, methyl cellulose, hydroxyethyl cellulose, polyvinyl alcohol (PVOH), styrene-maleic anhydride (SMA), styrene acrylic acid (SAA), alginates, guar gum, pectin, starch, ethylated starches, cationic starches, oxidized starches, acetylated starches, cyanoethylated starches, and combinations thereof. 
     
     
         4 . The process of  claim 1 , wherein the inorganic nanoparticle component comprises silica, silica modified with at least one silane coupling agent, clay, or combinations thereof, and wherein:
 a) the at least one inorganic nanoparticle component comprises smectites, kaolins, illites, chlorites, attapulgites, sepiolites, montmorillonite, bentonite, pyrophyllite, hectorite, saponite, sauconite, nontronite, talc, beidellite, volchonskoite, vermiculite, kaolinite, dickite, halloysite, nacrite, antigorite, illite anauxite, indellite, chrysotile, bravaisite, suscovite, paragonite, biotite, corrensite, penninite, donbassite, sudoite, pennine, sepiolite, polygorskyte, clinochlore, chamosite, nimite, pennantite muscovite, phlogopite, phengite, synthetic hectorite, or any combination thereof; and   b) the silane coupling agent comprises a substituted trialkoxysilane, a cationic polymer, or combinations thereof.   
     
     
         5 . The process of  claim 1 , wherein the at least one fluorochemical is selected from anionic fluorochemicals, cationic fluorochemicals, amphoteric fluorochemicals, non-ionic fluorochemicals, polymeric fluorochemicals, hybrid fluorochemicals, fluorochemical allophanates, fluorochemical polyacrylates, fluorochemical urethanes, fluorochemical carbodiimides, fluorochemical quanidines, and combinations thereof. 
     
     
         6 . The process of  claim 1 , wherein
 a) the at least one inorganic nanoparticle component comprises synthetic hectorite and is present in an amount from about 0.01% to about 25% weight in the dispersion or from about 200 ppm to about 4000 ppm OWPF on the oil-repellent cellulose fiber material;   b) the at least one fluorochemical is present in the dispersion in an amount to provide from about 0.0001% to about 5% weight fluorine atoms in the dispersion or from about 25 ppm to about 1000 ppm OWPF on the oil-repellent cellulose fiber material; or   c) both conditions a) and b) exist.   
     
     
         7 . A paper or paperboard made according to the process of  claim 1 . 
     
     
         8 . A process for improving the oil and grease resistance of a cellulose fiber material, the process comprising:
 a) contacting a cellulose fiber material with a first aqueous dispersion comprising at least one inorganic nanoparticle component to form a nanoparticle-treated cellulose fiber material; and   b) contacting the nanoparticle-treated cellulose fiber material with a second aqueous dispersion comprising i) at least one fluorochemical or ii) at least one inorganic nanoparticle component and at least one fluorochemical, to form an oil-repellent cellulose fiber material.   
     
     
         9 . The process of  claim 8 , wherein the first aqueous dispersion, the second aqueous dispersion, or both further comprise:
 a) a cationic polymer selected from a polyamine, a poly-vinyl amine, a polyethylene imine (PEI), a polyamidoamine, a polyamidoamine epichlorohydrin (PAE), a polyacrylamide, a starch, a prepolymer derived from condensation of adipic acid and diethylenetriamine (DETA), and combinations thereof; or   b) a film-forming polymer selected from hemicellulose, carboxymethyl cellulose, methyl cellulose, hydroxyethyl cellulose, polyvinyl alcohol (PVOH), styrene-maleic anhydride (SMA), styrene acrylic acid (SAA), alginates, guar gum, pectin, starch, ethylated starches, cationic starches, oxidized starches, acetylated starches, cyanoethylated starches, and combinations thereof.   
     
     
         10 . The process of  claim 8 , wherein the inorganic nanoparticle component comprises silica, silica modified with at least one silane coupling agent, clay, or combinations thereof, and wherein:
 a) the at least one inorganic nanoparticle component comprises smectites, kaolins, illites, chlorites, attapulgites, sepiolites, montmorillonite, bentonite, pyrophyllite, hectorite, saponite, sauconite, nontronite, talc, beidellite, volchonskoite, vermiculite, kaolinite, dickite, halloysite, nacrite, antigorite, illite anauxite, indellite, chrysotile, bravaisite, suscovite, paragonite, biotite, corrensite, penninite, donbassite, sudoite, pennine, sepiolite, polygorskyte, clinochlore, chamosite, nimite, pennantite muscovite, phlogopite, phengite, synthetic hectorite, or any combination thereof; and   b) the silane coupling agent comprises a substituted trialkoxysilane, a cationic polymer, or combinations thereof.   
     
     
         11 . The process of  claim 8 , wherein the at least one fluorochemical is selected from anionic fluorochemicals, cationic fluorochemicals, amphoteric fluorochemicals, non-ionic fluorochemicals, polymeric fluorochemicals, hybrid fluorochemicals, fluorochemical allophanates, fluorochemical polyacrylates, fluorochemical urethanes, fluorochemical carbodiimides, fluorochemical quanidines, and combinations thereof. 
     
     
         12 . A paper or paperboard made according to the process of  claim 8 . 
     
     
         13 . A process for improving the oil and grease resistance of a cellulose fiber material, the process comprising:
 a) applying a pretreatment composition comprising a first cationic polymer, a film-forming polymer, or a combination thereof to a cellulose fiber material to form a pretreated cellulose substrate;   b) drying the pretreated cellulose substrate; and   c) applying a fluorochemical composition comprising: i) at least one fluorochemical; or ii) at least one inorganic nanoparticle component and at least one fluorochemical to the dry pretreated cellulose substrate to form an oil-repellent cellulose fiber material.   
     
     
         14 . The process of  claim 13 , wherein:
 a) the first cationic polymer is selected from a polyamine, a poly-vinyl amine, a polyethylene imine (PEI), a polyamidoamine, a polyamidoamine epichlorohydrin (PAE), a polyacrylamide, a starch, a prepolymer derived from condensation of adipic acid and diethylenetriamine (DETA), and combinations thereof;   b) the fluorochemical composition further comprises a second cationic polymer selected independently from a polyamine, a poly-vinyl amine, a polyethylene imine (PEI), a polyamidoamine, a polyamidoamine epichlorohydrin (PAE), a polyacrylamide, a starch, a prepolymer derived from condensation of adipic acid and diethylenetriamine (DETA), and combinations thereof; or   c) both conditions a) and b) are present.   
     
     
         15 . The process of  claim 13 , wherein the cationic polymer is prepared by reacting an epihalohydrin with a compound having the formula:
   Z—(X) y —C(O)—NH[(CH 2 ) m —NH] n —C(O)—(X) y —Z, wherein
   Z is a radical selected from an alkyl radical of the formula C s H (2s+1) , where s is an integer having a value of from 3 to 20 inclusive, and cycloalkyl radicals of the formula C t H (2t−1) , where t is an integer having a value of from 4 to 6 inclusive;   X is a radical selected from straight chain alkylene radicals of the formula (CH 2 ) p , where p is an integer having a value of from 2 to 14 inclusive, cycloaliphatic radicals, bridged cycloaliphatic radicals, —CH═CH—(CH 2 ) b —O—(CH 2 ) 2 —, —CH 2 —CH 2 —(CH 2 ) b —O—(CH 2 ) 2 —, —CH═CH—(CH 2 ) b —S—(CH 2 ) 2 —, —CH 2 —CH 2 —(CH 2 ) b —S—(CH 2 ) 2 — radicals, where b is zero or an integer of from 1 to 14 inclusive and —SO 2 —N(R)—(CH 2 ) q — radicals, where R is an alkyl radical containing from 1 to 6 carbon atoms and q is an integer of from 2 to 12 inclusive;   y is 0 or 1;   m is an integer of from 2 to 6 inclusive;   and n is an integer of from 2 to 100 inclusive.   
     
     
         16 . The process of  claim 13 , wherein the film-forming polymer is selected from hemicellulose, carboxymethyl cellulose, methyl cellulose, hydroxyethyl cellulose, polyvinyl alcohol (PVOH), styrene-maleic anhydride (SMA), styrene acrylic acid (SAA), alginates, guar gum, pectin, starch, ethylated starches, cationic starches, oxidized starches, acetylated starches, cyanoethylated starches, and combinations thereof. 
     
     
         17 . The process of  claim 13 , wherein the pretreatment composition further comprises an anionic polymer. 
     
     
         18 . The process of  claim 13 , wherein the anionic polymer is selected from a copolymer of styrene with fumaric acid, maleic acid, glutaconic acid, traumatic acid, muconic acid, and combinations thereof. 
     
     
         19 . The process of  claim 13 , wherein the fluorochemical composition comprises anionic fluorochemicals, cationic fluorochemicals, amphoteric fluorochemicals, non-ionic fluorochemicals, polymeric fluorochemicals, or hybrid fluorochemicals. 
     
     
         20 . The process of  claim 13 , wherein:
 a) the cationic polymer, the film-forming polymer, or the combination thereof is present in the pretreatment composition in an amount from about 0.01% to about 25% by weight in the aqueous dispersion;   b) the fluorochemical composition comprises at least one fluorochemical present in an aqueous medium in an amount from about 0.0001% to about 5% by weight; or   c) both conditions a) and b) are present.   
     
     
         21 . The process of  claim 13 , wherein pretreatment composition or the fluorochemical composition further comprises an inorganic nanoparticle component comprising: silica; silica modified with at least one silane coupling agent selected from a substituted trialkoxysilane, a cationic polymer, or combinations thereof; clay; or combinations thereof. 
     
     
         22 . A paper or paperboard made according to the process of  claim 13 .