Biodegradable coated substrates

Abstract

Coated substrates include a coating and a substrate is selected from the group consisting of paper, fabric, thread and yarn. The coating comprises a biodegradable polyhydroxyalkanoate copolymer, wherein the biodegradable polyhydroxyalkanoate copolymer comprises a first randomly repeating monomer unit having the structure: wherein R 1 is H or a C 1-2 alkyl, and n is 1 or 2; and a second randomly repeating monomer unit having the structure: wherein R 2 is a C 3-19 alkyl or a C 3-19 alkenyl; and wherein at least 50% of the randomly repeating monomer units have the structure of the first randomly repeating monomer unit.

What is claimed is:  
     
         1 . A coated substrate comprising a substrate and a coating comprising a biodegradable polyhydroxyalkanoate copolymer, wherein the biodegradable polyhydroxyalkanoate copolymer comprises a first randomly repeating monomer unit having the structure:  
       
         
           
           
               
               
           
         
       
       wherein 
 R 1  is H or a C 1-2  alkyl, and n is 1 or 2; and  
 a second randomly repeating monomer unit having the structure:  
                     
 wherein  
 R 2  is a C 3-19  alkyl or a C 3-19  alkenyl; and  
 wherein at least 50% of the randomly repeating monomer units have the structure of the first randomly repeating monomer unit, and wherein the substrate is selected from the group consisting of paper, fabric, thread and yarn.  
 
     
     
         2 . A coated substrate according to  claim 1 , wherein the biodegradable polyhydroxyalkanoate copolymer further comprises a third randomly repeating monomer unit having the structure:  
       
         
           
           
               
               
           
         
       
       wherein 
 R 3  is H, a C 1-19  alkyl or a C 1-19  alkenyl, and m is 1 or 2; and  
 wherein the third randomly repeating monomer unit is not the same as the first randomly repeating monomer unit or the second randomly repeating monomer unit.  
 
     
     
         3 . A coated substrate according to  claim 1 , wherein R 1  is a C 1-2  alkyl and n is 1.  
     
     
         4 . A coated substrate according to  claim 1 , wherein R 1  is H and n is 2.  
     
     
         5 . A coated substrate according to  claim 1 , wherein the coating is substantially free of plasticizers.  
     
     
         6 . A method of improving the resistance to grease of a subtrate, comprising the step of applying a coating to a substrate selected from the group consisting of paper, fabric, thread and yarn, wherein the coating comprises a biodegradable polyhydroxyalkanoate copolymer comprising two randomly repeating monomer units wherein the first randomly repeating monomer unit has the structure:  
       
         
           
           
               
               
           
         
       
       wherein 
 R 1  is H or a C 1-2  alkyl, and n is 1 or 2; and  
 the second randomly repeating monomer unit has the structure:  
                     
 wherein  
 R 2  is a C 3-19  alkyl or a C 3-19  alkenyl; and  
 wherein at least 50% of the randomly repeating monomer units have the structure of the first randomly repeating monomer unit.  
 
     
     
         7 . A method according to  claim 6 , wherein the biodegradable polyhydroxyalkanoate copolymer further comprises a third randomly repeating monomer unit having the structure:  
       
         
           
           
               
               
           
         
       
       wherein 
 R 3  is H, a C 1-19  alkyl or a C 1-19  alkenyl, and m is 1 or 2; and  
 wherein the third randomly repeating monomer unit is not the same as the first randomly repeating monomer unit or the second randomly repeating monomer unit.  
 
     
     
         8 . A method according to  claim 6 , wherein R 1  is a C 1-2  alkyl and n is 1.  
     
     
         9 . A method according to  claim 8 , wherein R 1  is a C 1  alkyl.  
     
     
         10 . A method according to  claim 6 , wherein R 1  is H and n is 2.  
     
     
         11 . A method of coating a substrate, comprising the step of applying a coating to the substrate, wherein the coating comprises a biodegradable polyhydroxyalkanoate copolymer comprising two randomly repeating monomer units wherein the first randomly repeating monomer unit has the structure:  
       
         
           
           
               
               
           
         
       
       wherein 
 R 1  is H or a C 1-2  alkyl, and n is 1 or 2; and  
 the second randomly repeating monomer unit has the structure:  
                     
 wherein  
 R 2  is a C 3-19  alkyl or a C 3-19  alkenyl; and  
 wherein at least 50% of the randomly repeating monomer units have the structure of the first randomly repeating monomer unit, and wherein the substrate is selected from the group consisting of paper and fabric.  
 
     
     
         12 . A method according to  claim 11 , wherein the step of applying the coating to the substrate comprises laminating the substrate with a film comprising the biodegradable polyhydroxyalkanoate copolymer.  
     
     
         13 . A method according to  claim 12 , wherein the film is a solution cast film.  
     
     
         14 . A method according to  claim 12 , wherein the film is a melt pressed film.  
     
     
         15 . A method according to  claim 11 , wherein the step of applying the coating to the substrate comprises: 
 (a) preparing a coating composition comprising polyhydroxyalkanoate copolymer;    (b) applying the coating composition to the substrate to obtain a coated substrate; and    (c) allowing the coated substrate to dry.    
     
     
         16 . A method according to  claim 15 , further comprising the step subjecting the substrate to pressure.  
     
     
         17 . A method according to  claim 15 , wherein the coating composition is a solution.  
     
     
         18 . A method according to  claim 15 , wherein the coating composition is a slurry.  
     
     
         19 . A method according to  claim 15 , wherein the coating composition is a suspension.  
     
     
         20 . A method according to  claim 11 , wherein the step of applying the coating to the substrate comprises extrusion coating the substrate.