Protective coating

Abstract

A composition is provided consisting of an aqueous solution comprising at least one natural polysaccharide or a derivative thereof and at least one polymeric polyamino compound, the composition being capable of forming a film when applied onto a substrate. The invention also involves a method for temporary protection of a substrate surface from environmental influence using such composition.

1 . A composition consisting of an aqueous solution comprising at least one natural polysaccharide selected from the group consisting of plant gums, bacterial polysaccarides, and algae polysaccarides or a derivative thereof and at least one polymeric polyamino compound, said composition being capable of forming a film, via at least partial gel formation, when applied onto a substrate.  
   
   
       2 . A composition according to  claim 1 , capable of forming said film by evaporation of aqueous solvent.  
   
   
       3 . A composition according to  claim 1 , capable of forming said film via gel formation by cooling from an elevated temperature and then evaporation.  
   
   
       4 . A composition according to  claim 1 , wherein said polysaccharide has a β-1,4-glycan backbone.  
   
   
       5 . A composition according to  claim 1 , wherein said polysaccharide is a plant gum.  
   
   
       6 . A composition according to  claim 1 , wherein said polymeric polyamino compound is selected from the group consisting of proteins, polysaccharides and derivatives thereof containing amino functions, and aliphatic polymers containing amino functions.  
   
   
       7 . A composition according to  claim 6 , wherein said polyamino compound is a soluble cellulose or starch derivative containing amino functions.  
   
   
       8 . A composition according to  claim 6 , wherein said polyamino compound is chitosan or an aliphatic polymer containing amino functions.  
   
   
       9 . A composition according to  claim 1 , wherein said polyamino compound is a polyethylenimine.  
   
   
       10 . A composition according to  claim 2 , wherein said polysaccharide has a β-1,4-glycan backbone.  
   
   
       11 . A composition according to  claim 3 , wherein said polysaccharide has a β-1,4-glycan backbone.  
   
   
       12 . A composition according to  claim 1 , wherein the weight ratio between said polysaccharide and said polyamino compound is within the range about 5:1 to 1:5.  
   
   
       13 . A composition according to  claim 12 , wherein said range is from about 3:1 to 1:3.  
   
   
       14 . A composition according to  claim 1 , wherein said polysaccharide together with said polyamino compound are present in the aqueous solution in an amount of not more than about 10% by weight.  
   
   
       15 . A method for temporary protection of a substrate surface from environmental influence, comprising application onto said surface a composition according to  claim 1 , allowing evaporation of aqueous solvent from said composition as applied to form a protective film via at least partial gel formation on said surface, said film being removable by treatment with water.  
   
   
       16 . A method according to  claim 15 , wherein said film is removable by water having a temperature above room temperature.  
   
   
       17 . A method according to  claim 15 , wherein said film is removable by pressure washing with a stream of water.  
   
   
       18 . A method according to  claim 15  for the temporary protection of the exterior of a vehicle during handling and transportation.  
   
   
       19 . A method according to  claim 15  for the protection of an under-water structure to protect from under-water growth.  
   
   
       20 . A method according to  claim 15  for the protection of plant seedlings from microbial or insecticidal attack.  
   
   
       21 . A method according to  claim 15  for the protection of silverware from discoloration.  
   
   
       22 . A composition according to  claim 1 , further containing a buffering system.  
   
   
       23 . A composition according to  claim 1 , wherein the pH is within the range of from about 5 to about 9.  
   
   
       24 . A method according to  claim 17  for the temporary protection of the exterior of a vehicle during handling and transportation.  
   
   
       25 . A method according to  claim 16  for the protection of an under-water structure to protect from under-water growth.  
   
   
       26 . A method according to  claim 17  for the protection of an under-water structure to protect from under-water growth.  
   
   
       27 . A method according to  claim 16  for the protection of plant seedlings from microbial or insecticidal attack.  
   
   
       28 . A method according to  claim 17  for the protection of plant seedlings from microbial or insecticidal attack.  
   
   
       29 . A method according to  claim 16  for the protection of silverware from discoloration.  
   
   
       30 . A method according to  claim 17  for the protection of silverware from discoloration.