Polyester with high carboxyl end groups and methods for making
View Patent ↗The present invention relates to a polyester or copolyester composition containing a substituted cyclic anhydride, having a carboxyl end group of greater or equal to 25 mmol/kg. The present invention also concerns a method of making such a polyester or copolyester by late injection of the substituted cyclic anhydride at the end of polycondensation, or alternatively adding the substituted cyclic anhydride to the preform injection molding machine, prior to stretch blow molding a container.
1. A resin comprising: polyethylene terephthalate or a copolyester of polyethylene terephthalate and a dicarboxylic acid or its ester equivalent or a copolyester of polyethylene terephthalate and a diol, and substituted cyclic anhydride, said substituted cyclic anhydride being not more than 100 microequivalents per gram of said polyester or copolyester, said resin having a CEG content greater than about 25 microequivalents per gram, said substituted cyclic anhydride is selected form the class consisting of:
a) substituted succinic anhydrides
where R 1 , R 2 , R 3 , and R 4 can be hydrogen, alkyl, alkenyl or aryl groups, and at least one group is not hydrogen;
b) substituted maleic anhydride
where R 1 and R 2 can be hydrogen, alkyl, alkenyl or aryl groups, and at least one group is not hydrogen;
c) substituted glutaric anhydride
where R 1 , R 2 , R 3 , R 4 , R 5 and R 6 can be hydrogen, alkyl, alkenyl or aryl groups, and at least one group is not hydrogen;
d) diglycolic anhydride and substituted diglycolic anhydride
where R 1 , R 2 , R 3 and R 4 can be hydrogen, alkyl, alkenyl or aryl groups;
e) Substituted phthalic anhydride
where R 1 , R 2 , R 3 , and R 4 can be hydrogen, alkyl, alkenyl or aryl groups, and at least one group is not hydrogen;
f) diphenic anhydride and substituted diphenic anhydride
where R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 and R 8 can be hydrogen, alkyl, alkenyl or aryl groups.
2. The resin of claim 1 , wherein said substituted succinic anhydride is selected from the group of methyl succinic anhydride, 2,2-dimethyl succinic anhydride, phenyl succinic anhydride, octadecenyl succinic anhydride, hexadecenyl succinic anhydride, eicosodecenyl succinic anhydride, 2-methylene succinic anhydride, and mixtures of these.
3. The resin of claim 1 , wherein said substituted glutaric anhydride is selected from the group of 3-methyl glutaric anhydride, phenyl glutaric anhydride, diglycolic anhydride, 2-ethyl 3-methyl glutaric anhydride, 2,2-dimethyl glutaric anhydride, 3,3-tetrametheylene glutaric anhydride, and mixtures of these.
4. The resin of claim 1 , wherein said substituted phthalic anhydride is selected from the group of 4-methyl phthalic anhydride, 4-t-butyl phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, and mixtures of these.
5. The resin of claim 1 , wherein said substituted maleic anhydride is selected from the group of tetrahydrophthalic anhydride, dimethyl maleic anhydride, 1-cyclopentene-1,2-dicarboxylic anhydride or mixtures of these.
6. The resin of claim 1 , wherein said resin has an I.V. of greater than about 0.70.
7. The resin of claim 1 , wherein said CEG is less than about 80 microequivalents per gram.
8. A preform made from polyethylene terephthalate or a copolyester of polyethylene terephthalate and a dicarboxylic acid or its ester equivalent or a copolyester of polyethylene terephthalate and a diol, and substituted cyclic anhydride, said substituted cyclic anhydride being not more than 100 microequivalents per gram of said polyester or copolyester, said resin having a CEG content greater than about 25 microequivalents per gram, said substituted cyclic anhydride is selected form the class consisting of:
a. substituted succinic anhydrides
where R 1 , R 2 , R 3 , and R 4 can be hydrogen, alkyl, alkenyl or aryl groups, and at least one group is not hydrogen;
b. substituted maleic anhydride
where R 1 , R 2 can be hydrogen, alkyl, alkenyl or aryl groups, and at least one group is not hydrogen;
c. substituted glutaric anhydride
where R 1 , R 2 , R 3 , R 4 , R 5 and R 6 can be hydrogen, alkyl, alkenyl or aryl groups, and at least one group is not hydrogen;
d. diglycolic anhydride and substituted diglycolic anhydride
where R 1 , R 2 , R 3 , and R 4 can be hydrogen, alkyl, alkenyl or aryl groups;
e. Substituted phthalic anhydride
where R 1 , R 2 , R 3 , and R 4 can be hydrogen, alkyl, alkenyl or aryl groups, and at least one group is not hydrogen;
f. diphenic anhydride and substituted diphenic anhydride
where R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 and R 8 can be hydrogen, alkyl, alkenyl or aryl groups.
9. A bottle made from polyethylene terephthalate or a copolyester of polyethylene terephthalate and a dicarboxylic acid or its ester equivalent or a copolyester of polyethylene terephthalate and a diol, and substituted cyclic anhydride, said substituted cyclic anhydride being not more than 100 millimoles per kilogram of said polyester or copolyester, said resin having a CEG content greater than about 25 millimoles per kilogram, said substituted cyclic anhydride is selected form the class consisting of:
a. substituted succinic anhydrides
where R 1 , R 2 , R 3 , and R 4 can be hydrogen, alkyl, alkenyl or aryl groups, and at least one group is not hydrogen;
b. substituted maleic anhydride
where R 1 and R 2 can be hydrogen, alkyl, alkenyl or aryl groups, and at least one group is not hydrogen;
c. substituted glutaric anhydride
where R 1 , R 2 , R 3 , R 4 , R 5 and R 6 can be hydrogen, alkyl, alkenyl or aryl groups, and at least one group is not hydrogen;
d. diglycolic anhydride and substituted diglycolic anhydride
where R 1 , R 2 , R 3 , and R 4 can be hydrogen, alkyl, alkenyl or aryl groups;
e. Substituted phthalic anhydride
where R 1 , R 2 , R 3 , and R 4 can be hydrogen, alkyl, alkenyl or aryl groups, and at least one group is not hydrogen;
f. diphenic anhydride and substituted diphenic anhydride
where R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 and R 8 can be hydrogen, alkyl, alkenyl or aryl groups.
10. A method of making a resin, used to make a container having reduced caustic stress cracking, comprising: forming polyester or copolyester by esterification followed by polycondensation to make a polyethylene terephthalate or polyethylene terephthalate copolyester; adding at the end of said polycondensation not more than 100 millimoles per kilogram based on said polyester or copolyester of a substituted cyclic anhydride, said resin having a CEG content greater than about 25 millimoles per kilogram, wherein said resin has a I.V of greater than about 0.70, said substituted cyclic anhydride is selected form the class consisting of:
a. substituted succinic anhydrides
where R 1 , R 2 , R 3 , and R 4 can be hydrogen, alkyl, alkenyl or aryl groups, and at least one group is not hydrogen;
b. substituted maleic anhydride
where R 1 and R 2 can be hydrogen, alkyl, alkenyl or aryl groups, and at least one group is not hydrogen;
c. substituted glutaric anhydride
where R 1 , R 2 , R 3 , R 4 , R 5 and R 6 can be hydrogen, alkyl, alkenyl or aryl groups, and at least one group is not hydrogen;
d. diglycolic anhydride and substituted diglycolic anhydride
where R 1 , R 2 , R 3 , and R 4 can be hydrogen, alkyl, alkenyl or aryl groups;
e. Substituted phthalic anhydride
where R 1 , R 2 , R 3 , and R 4 can be hydrogen, alkyl, alkenyl or aryl groups, and at least one group is not hydrogen;
f. diphenic anhydride and substituted diphenic anhydride
where R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 and R 8 can be hydrogen, alkyl, alkenyl or aryl groups.
11. The method of claim 10 , wherein said substituted succinic anhydride is selected from the group of methyl succinic anhydride, 2,2-dimethyl succinic anhydride, phenyl succinic anhydride, octadecenyl succinic anhydride, hexadecenyl succinic anhydride, eicosodecenyl succinic anhydride, 2-methylene succinic anhydride, and mixtures of these.
12. The method of claim 10 , wherein said substituted glutaric anhydride is selected from the group of 3-methyl glutaric anhydride, phenyl glutaric anhydride, diglycolic anhydride, 2-ethyl 3-methyl glutaric anhydride, 2,2-dimethyl glutaric anhydride, 3,3-tetramethylene glutaric anhydride, and mixtures of these.
13. The method of claim 10 , wherein said substituted phthalic anhydride is selected from the group of 4-methyl phthalic anhydride, 4-t-butyl phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, and mixtures of these.
14. The method of claim 10 , wherein said substituted maleic anhydride is selected from the group of tetrahydrophthalic anhydride, dimethyl maleic anhydride, 1-cyclopentene-1,2-dicarboxylic anhydride or mixtures of these.
15. The method of claim 10 , wherein said substituted anhydride has a melt point of less than about 100° C.
16. The method of claim 10 , wherein said substituted anhydride has a melt point at about 25° C.
17. A container having reduced caustic stress cracking made from the resin produced according to claim 10 .