Clear polyphenylene ether/block copolymer composition

Abstract

A clear polyphenylene ether composition having improved impact strength comprising said polyphenylene ether and a block copolymer having a resinous block and a rubbery block wherein the resinous block is relatively high molecular weight and is derived from either styrene or butadiene with a resinous content of the block copolymer being within the range of 45 to 58 weight percent.

What is claimed is: 
     
       1. A clear composition comprising: a polyphenylene ether; and   a hydrogenated AB block copolymer having a terminal resinous block derived from styrene or a-methylstyrene and a rubbery block derived from a 4-8 carbon atom conjugated alkadiene, said resinous block having a molecular weight within the range of 23,000-100,000, the total resinous component content of said block copolymer being within the range of 45-58 weight percent;   wherein the total molecular weight of said block copolymer is within the range of 40,000-225,000, said block copolymer being present in an amount within the range of 2-30 weight percent based on the weight of said polyphenylene ether and said block copolymer;   wherein said block copolymer is hydrogenated to the extent that unsaturation is said rubbery block is reduced to less than 10% of the original unsaturation; and   wherein no more than 10% of the original aromatic unsaturation of said resinous block is removed.   
     
     
       2. A composition according to claim 1 wherein said conjugated alkadiene is selected from the group consisting of isoprene and butadiene and said block copolymer is present in an amount within the range of 5-25 weight percent. 
     
     
       3. A composition according to claim 1 wherein said resinous block has a molecular weight within the range of 40,000-80,000, said total molecular weight of said block copolymer is within the range of 60,000-160,000, and wherein said block copolymer is present in an amount within the range of 10-25 weight percent based on the weight of said polyphenylene ether and said block copolymer. 
     
     
       4. A composition according to claim 1 wherein said polyphenylene ether is poly(2,6-dimethyl-1,4-phenylene)ether. 
     
     
       5. A composition according to claim 1 comprising in addition a stabilizer. 
     
     
       6. A composition according to claim 5 wherein said stabilizer is tetrakis (methylene(3,5-di-t-butyl-4-hydroxyhydrocinnamate)) methane. 
     
     
       7. A clear composition comprising: a polyphenylene ether;   a hydrogenated AB block copolymer having a terminal resinous block derived from styrene or a-methylstyrene and a rubbery block derived from a 4-8 carbon atom conjugated alkadiene, said resinous block having a molecular weight within the range of 23,000-100,000, the total resinous component content of said block copolymer being within the range of 45-58 weight percent wherein the total molecular weight of said block copolymer is within the range of 40,000-225,000, said block copolymer being present in an amount within the range of 2-30 weight percent based on the weight of said polyphenylene ether and said block copolymer; and   a stabilizer.   
     
     
       8. A composition comprising: a polyphenylene ether of the formula ##STR2## wherein Q, Q', Q" and Q'", are independently selected from the group consisting of hydrogen, hydrocarbon radicals, halohydrocarbon radicals having at least two carbon atoms between the halogen atom and the phenol nucleus, hydrocarbonoxy radicals and halohydrocarbonoxy radicals having at least two carbon atoms between the halogen atoms and the phenol nucleus, and Q', Q" and Q'" in addition may be halogen with the proviso that if Q', Q" or Q'" are halogen Q and Q' are preferably free of tertiary carbon atoms; and n represents the total number of monomer residues and is an integer of at least 50;   a block copolymer having the general configuration of AB wherein A is a polymerized styrene block and B is an ethylene/propylene block derived from hydrogenation of polymerized isoprene; and   a stabilizer;   wherein said polymerized styrene block has a molecular weight within the range of 23,000-100,000 and constitutes 45-58 weight percent of said block copolymer, wherein said block copolymer has a molecular weight within the range of 40,000-225,000 and wherein said block copolymer is present in said composition in an amount within the range of 2-30 weight percent based on the weight of said polyphenylene ether and said block copolymer.   
     
     
       9. A composition according to claim 8 comprising an addition of stabilizer. 
     
     
       10. A composition according to claim 9 wherein said stabilizer is tetrakis-(methylene(3,5-di-t-butyl-4-hydroxyhydrocinnamate)) methane. 
     
     
       11. A composition according to claim 10 wherein said hydrogenated polymerized isoprene contains less than 10% of the original unsaturation in the unhydrogenated polymerized isoprene and wherein greater than 90% of the polymerized styrene aromatic unsaturation remains. 
     
     
       12. A composition according to claim 10 wherein said polymerized styrene block has a molecular weight within the range of 40,000-80,000, said molecular weight of said block copolymer is within the range of 60,000-160,000 and wherein said block copolymer is present in an amount within the range of 10-25 weight percent based on the weight of said polyphenylene ether and said block copolymer and wherein said polyphenylene ether is poly(2,6-dimethyl-1,4-phenylene)ether. 
     
     
       13. A composition according to claim 12 wherein said ethylene/propylene block has a molecular weight of less than 150,000. 
     
     
       14. A composition according to claim 8 comprising in addition an amount of polystyrene sufficient to improve processability but less than 10 weight percent. 
     
     
       15. A composition according to claim 8 comprising in addition 2 to 5 weight percent polystyrene based on total weight of said composition.