Polyester-ether resin blends
The present application relates to novel polyester-ether compositions and their use as oxygen scavenging materials in polyester resins.
1. A composition for preparing an article, preform or container comprising:
a) 80-98.5 parts by weight of a base polyester;
b) 0.5-20 parts by weight of a copolyester-ether,
wherein the copolyester-ether comprises one or more polyester segments and one or more polyether segments, wherein the one or more polyether segments are present in an amount of about 5 to about 95 wt.-% of the copolyester-ether;
c) a transition metal-based oxidation catalyst; and
d) a monomeric, oligomeric or polymeric hindered amine light stabilizer (HALS) in an amount of 15-10,000 ppm, on basis of the weight of the stabilizer in the total composition, wherein the HALS is represented by the formula (I) or a mixture of compounds of formula (I),
wherein each R1 independently represents C1-C4 alkyl, R2 represents H, C1-C4 alkyl, OH, O—C1-C4 alkyl, or a further part of an oligomeric or polymeric HALS, and R3 represents a further part of a monomeric, oligomeric or polymeric HALS,
wherein addition of the HALS to the composition reduces degradation products without reducing oxygen barrier properties.
2. The composition of claim 1 , wherein the polyether segment is a linear or branched poly (C2-C6-alkylene glycol) segment.
3. The composition of claim 1 wherein the polyether segment has a number-average molecular weight of about 200 to about 5000 g/mol.
4. The composition of claim 1 , wherein the polyether segments are present in the copolyester-ether in an amount of about 15 to about 45 wt. %.
5. The composition of claim 1 , wherein the copolyester-ether comprises a polyethylene terephthalate (co)polyester segment.
6. The composition of claim 1 , wherein the HALS is a monomeric HALS having a molecular weight of 400 g/mol or above.
7. The composition of claim 1 , wherein the HALS is an oligomeric or polymeric HALS.
8. The composition of claim 7 , wherein the HALS is an oligomeric or polymeric HALS comprising one or more moieties of the formula (I),
wherein each R1 independently represents C1-C4 alkyl, R2 represents H or C1-C4 alkyl, and R3 represents a further part of the oligomeric or polymeric HALS.
9. The composition of claim 1 , wherein the HALS is present in an amount of about 20 to about 2500 ppm.
10. The composition of claim 1 , wherein transition metal-based oxidation catalyst is a cobalt compound.
11. The composition of claim 1 , wherein the transition metal-based oxidation catalyst is present in an amount of from about 15 to about 400 ppm based on the weight of the transition metal in the total composition.
12. The composition of claim 1 , wherein the weight ratio of the one or more polyether segments to the total amount of base polyester and polyester segments in the composition is from about 0.2 to about 10 wt. %.
13. A method of preparing the composition of claim 1 , comprising mixing the base polyester with:
a) 0.5-20 parts by weight of the copolyester-ether;
b) the transition metal-based oxidation catalyst; and
c) the HALS in an amount of 15-10,000 ppm, on basis of the weight of the stabilizer in the total composition.