Reduced by product polyamine-epihalohydrin resins

Abstract

Processes for rendering a polyamine-epihalohydrin resin storage stable, including processes that prepare a storage stable resin and/or processes that treat resins. A composition containing a polyamine-epihalohydrin resin which includes CPD-forming species can be treated with at least one agent under conditions to at least one of inhibit, reduce and remove the CPD-forming species to obtain a reduced CPD-forming resin so that a composition containing the reduced CPD-forming polyamine-epihalohydrin resin when stored for 2 weeks at 50° C., and a pH of about 2.5 to 3.5 contains less than about 250 ppm dry basis of CPD. The invention is also directed to a gelation storage stable reduced CPD-forming resin so that a composition containing the reduced CPD-forming polyamine-epihalohydrin resin, when stored at pH 1 for 24 hours at 50° C. and measured at 24 hours, produces less than about 1000 ppm dry basis of CPD. A paper product containing the storage stable polyaminopolyamide-epihalohydrin resin, when corrected for adding at about a 1 wt % addition level of the polyaminopolyamide-epihalohydrin resin, contains less than about 250 ppb of CPD. Moreover, a resin can be prepared starting from a prepolymer having a low acid number or low concentration of acid end groups. The invention is also directed to papers containing the resins.

1 . A process for rendering a polyamine-epihalohydrin resin storage stable, comprising: treating a composition containing a polyamine-epihalohydrin resin which includes CPD forming species, wherein the resin comprises a resin formed in a polyaminopolyamide-epihalohydrin reaction having a molar ratio of epihalohydrin to secondary amine group of less than 1, with at least one basic agent, wherein the at least one basic agent raises the pH of the composition containing the polyamine-epihalohydrin resin to a pH of about 10 to 12, under conditions to at least one of inhibit, reduce and remove the CPD-forming species to obtain a gelation storage stable reduced CPD-forming resin so that a composition containing the reduced CPD-forming polyamine-epihalohydrin resin, when stored at pH 1 for 24 hours at 50° C. and measured at 24 hours, produces less than about 250 ppm dry basis of CPD.  
     
     
         2 . The process according to  claim 1 , wherein the resin comprises a resin formed in a polyaminopolyamide-epihalohydrin reaction having a molar ratio of epihalohydrin to secondary amine group of from about 0.8 to about 0.975.  
     
     
         3 . The process according to  claim 1 , wherein, prior to the treating a polyamine- epihalohydrin resin to obtain a reduced CPD-forming resin, the resin is contacted with at least one microorganism, or at least one enzyme isolated from the at least one microorganism, in an amount, and at a pH and temperature effective to dehalogenate residual quantities of organically bound halogen.  
     
     
         4 . The process according to  claim 1 , wherein, subsequent to the treating a polyamine- epihalohydrin resin to obtain a reduced CPD-forming resin, the reduced CPD-forming resin is contacted with at least one microorganism, or at least one enzyme isolated from the at least one microorganism, in an amount, and at a pH and temperature effective to dehalogenate residual quantities of organically bound halogen.  
     
     
         5 . The process according to  claim 1 , wherein, prior to the treating a polyamine- epihalohydrin resin to obtain a reduced CPD-forming resin, the resin is treated to reduce at least one of epihalohydrins, epihalohydrin hydrolysis by-products and organic halogen bound to the polymer backbone.  
     
     
         6 . The process according to  claim 1 , wherein, subsequent to the treating a polyamine- epihalohydrin resin to obtain a reduced CPD-forming resin, the resin is treated to reduce at least one of epihalohydrins, epihalohydrin hydrolysis by-products and organic halogen bound to the polymer backbone.  
     
     
         7 . The process according to  claim 1  wherein the time for treatment with the basic agent is up to about 4 hour.  
     
     
         8 . The process according to  claim 1  wherein the time for treatment with the basic agent is up to about 1 hour.  
     
     
         9 . The process according to  claim 1 , wherein the composition has a temperature of at least about 40° C.  
     
     
         10 . The process according to  claim 1 , wherein the composition has a temperature of about 20° C. to 80° C.  
     
     
         11 . The process according to  claim 1 , wherein the reduced CPD-forming resin is acid stabilized after base treatment.  
     
     
         12 . The process according to  claim 10 , wherein the reduced CPD-forming resin is acid stabilized in a pH range of from about 2.5 to 4.  
     
     
         13 . The process according to  claim 1 , wherein the composition containing the reduced CPD-forming polyamine-epihalohydrin resin, when stored at pH 1 for 24 hours at 50° C. and measured at 24 hours, produces less than about 50 ppm dry basis of CPD.  
     
     
         14 . A process for preparing a paper product, comprising: treating a composition containing a polyamine-epihalohydrin resin which includes CPD-forming species with at least one basic agent, under conditions to at least one of inhibit, reduce and remove the CPD-forming species to obtain a gelation storage stable reduced CPD-forming resin, and forming a paper product with the reduced CPD-forming polyamine-epihalohydrin resin, so that a paper product, when corrected for adding at about a 1 wt % addition level of the reduced CPD-forming resin, contains less than about 250 ppb of CPD.  
     
     
         15 . The process according to  claim 14 , wherein the paper product contains less than about 50 ppb of CPD.  
     
     
         16 . The process according to  claim 14 , wherein the polyamine-epihalohydrin resin comprises polyaminopolyamide-epichlorohydrin resin.  
     
     
         17 . A paper product treated with resin produced according to the process according to  claim 1  .  
     
     
         18 . An aqueous composition comprising the reduced CPD-forming resin produced by the process according to  claim 1 .  
     
     
         19 . The aqueous composition according to  claim 14 , wherein the CPD-forming resin comprises polyalkylene polyamine-epihalohydrin resin.