Biodegradable material for injection molding and articles obtained therewith

Abstract

A biodegradable material containing starch, a polyvinyl alcohol-co-vinyl acetate copolymer and plasticizer is provided. The material is injection moldable to produce articles such as those for entertaining animals.

1 . Biodegradable material characterized in that it comprises:
 starch, present in an amount between 20 and 90% by weight with respect to the total weight;   a polyvinyl alcohol-co-vinyl acetate copolymer present in an amount between 5 and 50% by weight with respect to the total;   at least one plasticizer, present in an amount between 5 and 45% with respect to the total; wherein said polyvinyl alcohol-co-vinyl acetate copolymer has a degree of hydrolysis of >95%.   
     
     
         2 . Biodegradable material as claimed in  claim 1 , characterized in that said degree of hydrolysis is >97%. 
     
     
         3 . Biodegradable material as claimed in  claim 1 , characterized in that said degree of hydrolysis is >99%. 
     
     
         4 . Biodegradable material as claimed in  claim 1 , characterized in that said starch is present in an amount between 25 and 80% by weight. 
     
     
         5 . Biodegradable material as claimed in  claim 1 , characterized in that said starch is present in an amount between 30 and 70% by weight. 
     
     
         6 . Biodegradable material as claimed in  claim 1 , characterized in that said polyvinyl alcohol-co-vinyl acetate copolymer is present in an amount between 10 and 40% by weight with respect to the total weight. 
     
     
         7 . Biodegradable material as claimed in  claim 1 , characterized in that said polyvinyl alcohol-co-vinyl acetate copolymer is present in an amount between 15 and 35% by weight with respect to the total weight. 
     
     
         8 . Biodegradable material as claimed in  claim 1 , characterized in that said plasticizer is present in an amount between 10 and 43% by weight with respect to the total weight. 
     
     
         9 . Biodegradable material as claimed in  claim 1 , characterized in that said plasticizer is present in an amount between 15 and 40% by weight with respect to the total weight. 
     
     
         10 . Biodegradable material as claimed in  claim 1 , characterized in that said starch is corn starch. 
     
     
         11 . Biodegradable material as claimed in  claim 1 , characterized in that said plasticizer is selected from the group consisting of glycerol and water. 
     
     
         12 . Biodegradable material as claimed in  claim 11 , characterized in that said plasticizer is the water present in the starch. 
     
     
         13 . Biodegradable material as claimed in  claim 1 , characterized in that said plasticizer is solid at ambient temperature. 
     
     
         14 . Biodegradable material as claimed in  claim 13 , characterized in that said plasticizer is selected from the group consisting of sorbitol and pentaerythritol. 
     
     
         15 . Biodegradable material as claimed  claim 1 , characterized in that it has a viscosity in molten state, measured at T=180° C. and γ ap =103 s −1 , <1200 Pa·s. 
     
     
         16 . Biodegradable material as claimed  claim 1 , characterized in that it has a viscosity in molten state, measured at T=180° C. and γ ap =103 s −1 , <800 Pa·s. 
     
     
         17 . Biodegradable material as claimed  claim 1 , characterized in that it has a viscosity in molten state, measured at T=180° C. and γ ap =103 s −1 , <600 Pa·s. 
     
     
         18 . Biodegradable material as claimed in  claim 1 , characterized in that it has a crystallization temperature >105° C. 
     
     
         19 . Biodegradable material as claimed in  claim 1 , characterized in that it has a crystallization temperature >110° C. 
     
     
         20 . Biodegradable material as claimed in  claim 1 , characterized by further comprising a substance selected from the group consisting of colorings, flavorings, food supplements and fibers. 
     
     
         21 . Biodegradable material as claimed in  claim 1 , characterized by further comprising a substance selected from the group consisting of process additives. 
     
     
         22 . Biodegradable material as claimed in  claim 21 , characterized in that said process additives comprise fluidifying and slip agents, preferably chosen in the group constituted by calcium stearate and zinc stearate. 
     
     
         23 . Biodegradable material as claimed in  claim 21 , characterized in that said process additives are present in an amount from 0.1 to 5% by weight with respect to the total weight of the composition. 
     
     
         24 . Biodegradable material as claimed in  claim 21 , characterized in that said process additives are present in an amount between 0.5 and 3% by weight with respect to the total weight of the composition. 
     
     
         25 . Article to entertain animals obtained from biodegradable material as claimed in  claim 1 . 
     
     
         26 . Article to entertain animals as claimed in  claim 25 , characterized in that it has a digestibility >80% in terms of loss of weight, in a gastric and intestinal environment. 
     
     
         27 . Article to entertain animals as claimed in  claim 25 , characterized in that it has a digestibility >85% in terms of loss of weight, in a gastric and intestinal environment. 
     
     
         28 . Article to entertain animals as claimed in  claim 25 , characterized in that said article is preferably in the form of a bone. 
     
     
         29 . Films, thermoformed and foamed, obtained from the biodegradable material as claimed in  claim 1 . 
     
     
         30 . Biodegradable material as claimed in  claim 1 , utilizable for lacquer coating and layers of multilayers with other plastic materials, of cellulose or aluminum.