Process For Preservation Of Cellulosic Materials

Abstract

Process for conservation of a cellulosic material, comprising a treatment wherein said cellulosic material is contacted with a stabilising agent, and at least one of the cellulosic material or the stabilising agent is cooled before and/or during the treatment. A deacidification agent comprising magnesiumdipropoxycarbonate, propanol and an HFC selected from MFC-134a and EFC-227ea is particularly preferred as stabilising agent.

1 . Process for conservation of a cellulosic material, comprising a treatment wherein said cellulosic material is contacted with a stabilising agent, and at least one of the cellulosic material or the stabilising agent is cooled before and/or during the treatment.  
   
   
       2 . Process according to  claim 1 , wherein at least one of the cellulosic material or the stabilising agent is cooled to a temperature which is less than 20° C.  
   
   
       3 . Process according to  claim 2 , wherein the temperature is from −50° C. to 0° C.  
   
   
       4 . Process according to  claim 2 , wherein the treatment is carried out at a temperature which is less than 20° C.  
   
   
       5 . Process according to  claim 1 , wherein the cellulosic material and the stabilising agent have substantially the same temperature as they are being contacted.  
   
   
       6 . Process according to  claim 1 , wherein the stabilising agent comprises a fibre strengthener, sizing agent, antioxidant, biocide or deacidification agent or mixtures thereof.  
   
   
       7 . Process according  claim 6 , wherein the stabilising agent is a deacidification agent.  
   
   
       8 . Process according to  claim 7 , wherein the deacidification agent comprises a base which is a basic alkaline earth metal derivative.  
   
   
       9 . Process according to  claim 7 , wherein the deacidification agent comprises a solvent wherein said solvent is an alcohol, non-halogenated hydrocarbon solvent, halogenated hydrocarbon solvent, or ether.  
   
   
       10 . Process according to  claim 7 , wherein the deacidification agent comprises a hydrofluoroalkane.  
   
   
       11 . Process according to  claim 10 , wherein the deacidification agent is a composition comprising magnesium propylcarbonate, propanol and HFC-227ea.  
   
   
       12 . Process according to  claim 1 , wherein the treatment is carried out for a duration of from 1 to 50 hours.  
   
   
       13 . Process according to  claim 1 , wherein the cellulosic material is not dried before the treatment.  
   
   
       14 . Process according to  claim 1 , wherein the cellulosic material is dried before the treatment such that the drying results in a reduction of about 1% or 2% moisture content weight by weight.  
   
   
       15 . Process according to  claim 1 , which comprises 
 (a) cooling the stabilising agent; and    (b) contacting the cellulosic material and the stabilising agent cooled in step (a).    
   
   
       16 . Process according to  claim 1 , which comprises 
 (a) providing a treatment chamber equipped with a cooling device, which treatment chamber is cooled before the treatment;    (b) introducing cooled cellulosic material into the treatment chamber; and    (c) supplying the optionally cooled stabilising agent to said treatment chamber so as to contact the stabilising agent with the cellulosic material.    
   
   
       17 . Process according to  claim 1 , which comprises 
 (a) cooling the cellulosic material and optionally cooling the stabilising agent; and    (b) contacting the cellulosic material cooled in step (a) and the stabilising agent optionally cooled in step (a) in a treatment chamber.    
   
   
       18 . Process according to  claim 17 , whereby the treatment chamber is not cooled in step (b).  
   
   
       19 . Process according to  claim 17 , wherein both cellulosic material and stabilizing agent are cooled prior to contacting them in the treatment chamber.  
   
   
       20 . Process according to  claim 2  wherein the temperature is from −20° C. to −5° C.  
   
   
       21 . Process according to  claim 8  wherein the base comprises magnesium or calcium compounds or salts.  
   
   
       22 . Process according to  claim 9  wherein the deacidification agent comprises an alcohol solvent having 1 to 4 carbon atoms.  
   
   
       23 . Process according to  claim 10  wherein the deacidification agent comprises HFC-227ea or HFC-134a.  
   
   
       24 . Process according to  claim 10  wherein the deacidification agent is a composition comprising magnesium propylcarbonate, propanol and HFC-134a.  
   
   
       25 . Process according to  claim 15  which further comprises contacting the cellulosic material and the stabilising agent in a treatment chamber which has been cooled before introducing the cellulosic material.  
   
   
       26 . Process according to  claim 15  which further comprises separating excess quantities of stabilising agent or constituents of the stabilising agent from the cellulosic material.  
   
   
       27 . Process according to  claim 26  which further comprises recovering said separated excess quantities or constituents.  
   
   
       28 . Process according to  claim 16  which further comprises separating excess quantities of stabilising agent or constituents of the stabilising agent from the cellulosic material.  
   
   
       29 . Process according to  claim 28  which further comprises recovering said separated excess quantities or constituents.  
   
   
       30 . Process according to  claim 16  wherein the stabilising agent is cooled prior to being supplied to the treatment chamber.  
   
   
       31 . Process according to  claim 17  which further comprises separating excess quantities of stabilising agent or constituents of the stabilising agent from the cellulosic material.  
   
   
       32 . Process according to  claim 31  which further comprises recovering said separated excess quantities or constituents.