Stabilized polyphenylene ether resin and process for the preparation of the same

Abstract

Disclosed is a stabilized polyphenylene ether resin which comprises a plurality of polyphenylene ether chains, which chains collectively contain terminal 6-chroman groups in an amount of at least 0.01 in terms of the number of the terminal 6-chroman groups per 100 polyphenylene ether units in the resin. This polyphenylene ether resin has excellent resistance to thermal oxidation. A composition comprising this stabilized polyphenylene ether resin and a polystyrene resin has not only high resistance to thermal oxidation but also excellent moldability.

We claim: 
     
       1. A polyphenylene ether resin comprising a plurality of polyphenylene ether chains, each comprising recurring polyphenylene ether units, said plurality of polyphenylene ether chains collectively containing terminal 6-chroman groups represented by the following formula (a): ##STR25## wherein R 1  through R 5  each independently represent a hydrogen atom, . .an.!. .Iadd.a C 1  -C 20  .Iaddend.alkyl group. ., a substituted alkyl group.!. .Iadd.which is unsubstituted or substituted with a halogen atom, a hydroxyl group, an amino group or a lower alkoxyl group.Iaddend., a halogen atom, . .an.!. .Iadd.a C 6  -C 20  .Iaddend.aryl group . .or a substituted aryl group,.!. .Iadd.which is unsubstituted or substituted with a lower alkyl group, a halogen atom, a hydroxyl group, an amino group or a lower alkoxyl group; .Iaddend.and R 6  . .and.!. .Iadd.through .Iaddend.R 9  each independently represent a hydrogen atom, . .an.!. .Iadd.a C 1  -C 20  .Iaddend.alkyl group. ., a substituted alkyl group.!. .Iadd.which is unsubstituted or substituted with a halogen atom, a hydroxyl group, an amino group or a lower alkoxyl group.Iaddend., . .and.!. .Iadd.a lower .Iaddend.alkenyl group, a . .substituted alkenyl groups.!. .Iadd.1-hydroxyl-3-propenyl group.Iaddend., . .an.!. .Iadd.a C 6  -C 20  .Iaddend.aryl group . .or, a substituted aryl group.!. .Iadd.which is unsubstituted or substituted with a lower alkyl group, a lower alkoxyl group, a halogen atom, a hydroxyl group, an amino group or an aminoalkyl group or a carboxylic acid ester group, .Iaddend.   with the proviso that R 6  . .,.!. .Iadd.and .Iaddend.R 7 , .Iadd.and .Iaddend.R 8  and R 9  are independently bonded to form a ring or not bonded to each other,   wherein the amount of . .the.!. said terminal 6-chroman groups is at least 0.01 in terms of the number of said terminal 6-chroman groups per 100 phenylene ether units in the resin, and the number average molecular weight of the resin is in the range of from 1,000 to 100,000.   
     
     
       2. The polyphenylene ether resin according to claim 1, wherein the number of said terminal 6-chroman groups (a) is at least 0.15 on the average per 100 phenylene ether units. 
     
     
       3. The polyphenylene ether resin according to claim 2, wherein the number of said terminal 6-chroman groups is at least 0.2 on the average per 100 phenylene ether units. 
     
     
       4. The polyphenylene ether resin according to claim 1, wherein each of two or three substitutents of substituents R 6  through R 9  is a hydrogen atom. 
     
     
       5. The polyphenylene ether resin according to claim 1, wherein each of two or three substituents of substituents R 6  through R 9  is a hydrogen atom and each remaining substituent is independently selected from . .an.!. .Iadd.a C 6  -C 20  .Iaddend.aryl group . .and, a substituted aryl group.!. .Iadd.which is unsubstituted or substituted with a lower alkyl group, a lower alkoxyl group, a halogen atom, a hydroxyl group, an amino group or an aminoalkyl group; and a carboxylic acid ester group.Iaddend.. 
     
     
       6. The polyphenylene ether resin according to claim 5, wherein each of three substituents of substituents R 6  through R 9  is a hydrogen atom and the remaining substituent is a phenyl group, an alkyl-substituted phenyl group . .or.!..Iadd., .Iaddend.a halogenphenyl group .Iadd.or a carboxylic acid ester group.Iaddend.. 
     
     
       7. The polyphenylene ether resin according to claim 1, wherein 90 to 100% of the phenylene ether units are phenylene ether units represented by the following formula: ##STR26## wherein R 1  represents a methyl group and R 2  through R 5  each represent a hydrogen atom. 
     
     
       8. A process for the preparation of a polyphenylene ether resin of claim 1, which comprises heating a phenylene ether polymer having terminal groups represented by the following formula (c): ##STR27## wherein R 1  through R 5  each independently represent a hydrogen atom, . .an.!. .Iadd.a C 1  -C 20  .Iaddend.alkyl group. ., a substituted alkyl group.!. .Iadd.which is unsubstituted or substituted with a halogen atom, a hydroxyl group, an amino group or a lower alkoxyl group.Iaddend., a halogen atom, . .an.!. .Iadd.a C 6  -C 20  .Iaddend.aryl group . .or a substituted aryl group,.!. .Iadd.which is unsubstituted or substituted with a lower alkyl group, a halogen atom, a hydroxyl group, an amino group or a lower alkoxyl group; .Iaddend.and R 10  and R 11  each independently represent a hydrogen atom, . .an.!. .Iadd.a C 1  -C 20  .Iaddend.alkyl group . .or a substituted alkyl group.!., .Iadd.a C 1  -C 20  hydroxyalkyl group, a C 2  -C 22  alkoxyalkyl group, a C 3  -C 22  acyloxyalkyl group, or a C 4  -C 20  polyalkylene ether group,.Iaddend. with the proviso that R 10  and R 11  do not simultaneously represent a hydrogen atom, and a . .command.!. .Iadd.compound .Iaddend.having a carbon-to-carbon double bond, which is represented by the following formula (d): ##STR28##  wherein R 6  through R 9  each independently represent a hydrogen atom, . .an.!. .Iadd.a C 1  -C 20  .Iaddend.alkyl group. ., a substituted alkyl group.!. .Iadd.which is unsubstituted or substituted with a halogen atom, a hydroxyl group, an amino group or a lower alkoxyl group.Iaddend., . .an.!. .Iadd.a lower .Iaddend.alkenyl group, a . .substituted alkenyl groups.!. .Iadd.1-hydroxyl-3-propenyl group.Iaddend., . .an.!. .Iadd.a C 6  -C 20  .Iaddend.aryl group . .or, a substituted aryl group.!. .Iadd.which is unsubstituted or substituted with a lower alkyl group, a lower alkoxyl group, a halogen atom, a hydroxyl group, an amino group or an aminoalkyl group or a carboxylic acid ester group, .Iaddend.at a temperature of not lower than the glass transition temperature of the phenylene ether polymer in the absence of a radical polymerization initiator.   
     
     
       9. A resin composition comprising 1 to 99% by weight of a polyphenylene ether resin of claim 1 and 1 to 99% by weight of a polystyrene resin. 
     
     
       10. A polyphenylene ether resin according to claim 1, which is a film. 
     
     
       11. A resin composition according to claim 9, which is a film. .Iadd. 
     
     
       12.  The polyphenylene ether resin according to claim 1, 5 or 6, wherein said carboxylic acid ester group defined for R 6  through R 9  is selected from the group consisting of methyl carboxylate, ethyl carboxylate, propyl carboxylate, n-butyl carboxylate, isobutyl carboxylate, tert-butyl carboxylate, 2-ethylhexyl carboxylate, octyl carboxylate, isodecyl carboxylate, lauryl carboxylate, lauryltridecyl carboxylate, tridecyl carboxylate, cetylstearyl carboxylate, stearyl carboxylate, cyclohexyl carboxylate and benzyl carboxylate groups..Iaddend..Iadd.13. The polyphenylene ether resin according to claim 1, 5 or 6, wherein said carboxylic acid ester group defined for R 6  through R 9  is a stearyl carboxylate group..Iaddend..Iadd.14. The process according to claim 8, wherein said carboxylic acid ester group defined for R 6  through R 9  is selected from the group consisting of methyl carboxylate, ethyl carboxylate, propyl carboxylate, n-butyl carboxylate, isobutyl carboxylate, tert-butyl carboxylate, 2-ethylhexyl carboxylate, octyl carboxylate, isodecyl carboxylate, lauryl carboxylate, lauryltridecyl carboxylate, tridecyl carboxylate, cetylstearyl carboxylate, stearyl carboxylate, cyclohexyl carboxylate and benzyl carboxylate groups..Iaddend..Iadd.15. The process according to claim 8, wherein said carboxylic acid ester group defined for R 6  through R 9  is a stearyl carboxylate group..Iaddend.