Method of recovering impregnating agent compositions

Abstract

The present invention relates to processes for recovering impregnating compositions, the impregnated metal part being brought into contact with a salt-containing cleaning composition which comprises at least 0.7% by weight of at least one salt. In addition, the present invention describes processes for impregnating metal parts, which have at least one step for recovering impregnating compositions.

1 . A process for recovering impregnating compositions, wherein an impregnated metal part is brought into contact with a salt-containing cleaning composition which comprises at least 0.7% by weight of at least one salt. 
     
     
         2 . The process according to  claim 1 , wherein the salt is an inorganic salt. 
     
     
         3 . The process according to  claim 1 , wherein the salt is a phosphate. 
     
     
         4 . The process according to  claim 1 , wherein the cleaning composition is circulated. 
     
     
         5 . The process according to  claim 1 , wherein the cleaning composition comprises 4 to 20% by weight of salt. 
     
     
         6 . The process according to  claim 1 , wherein the impregnating composition comprises (meth)acrylates. 
     
     
         7 . The process according to  claim 6 , wherein the impregnating composition comprises 5% by weight to 95% by weight of hydroxyalkyl (meth)acrylates. 
     
     
         8 . The process according to  claim 6 , wherein the impregnating composition comprises 5% by weight to 75% by weight of crosslinking (meth)acrylates. 
     
     
         9 . The process according to  claim 6 , wherein the impregnating composition comprises 5% by weight to 60% by weight of comonomers. 
     
     
         10 . The process according to  claim 1 , wherein the impregnating composition comprises at least one initiator. 
     
     
         11 . The process according to  claim 10 , wherein the impregnating composition comprises from 0.01 to 10% by weight of initiator. 
     
     
         12 . The process according to  claim 1 , wherein the impregnating composition comprises at least one emulsifier. 
     
     
         13 . The process according to  claim 1 , wherein the solubility of the impregnating composition in the salt-containing cleaning composition is not more than 6% by weight. 
     
     
         14 . The process according to  claim 7 , wherein the solubility of hydroxypropyl methacrylate in the salt-containing cleaning composition is not more than 4% by weight. 
     
     
         15 . The process according to  claim 1 , wherein the density of the impregnating composition is in the range from 0.9 g/l to 1.2 g/l. 
     
     
         16 . The process according to  claim 1 , wherein the density difference between the impregnating composition and cleaning composition is at least 0.05 g/l. 
     
     
         17 . A process for impregnating metal parts, comprising at least one step for recovering impregnating compositions according to the process of  claim 1 . 
     
     
         18 . The process according to  claim 17 , wherein the metal part is first impregnated with an impregnating composition, the impregnated metal part is then brought into contact with a salt-containing cleaning composition, the metal part is then cleaned with water and the impregnating composition present in the metal part is hardened. 
     
     
         19 . The process according to  claim 17 , wherein the impregnating composition is brought into contact with the metal part at a pressure in the range from 0.1 mbar to 100 mbar. 
     
     
         20 . The process according to  claim 17 , wherein the metal part is exposed to a vacuum before the impregnation. 
     
     
         21 . The process according to  claim 17 , wherein excess impregnating composition is removed by centrifuging after the impregnation of the metal part. 
     
     
         22 . The process according to  claim 18 , wherein the impregnating composition present in the metal part is hardened at a temperature in the range from 60 to 120° C. 
     
     
         23 . The process according to  claim 18 , wherein the impregnating composition present in the metal part is hardened at a temperature in the range from 5 to 50° C.