Polyester Resins for High-Efficiency Injection Molding

Abstract

The present invention relates to titanium-catalyzed polyethylene terephthalate resins that are capable of being formed into articles (e.g., carbonated soft drink and water bottle preforms) at reduced injection-molding cycle times. In particular, the titanium-catalyzed polyethylene terephthalate resins of the present invention can be formed into carbonated soft drink bottle preforms at reduced injection-molding cycle times to yield high-clarity, carbonated soft drink bottles that possess satisfactory resistance to stress cracking and thermal creep.

Description

CROSS-REFERENCE TO PRIORITY APPLICATIONS[0001]This application is a continuation-in-part of commonly assigned International Patent Application No. PCT / US2006 / 061187 for Polyester Resins for High-Efficiency Injection Molding, filed Nov. 22, 2006, (and published May 31, 2007, as Publication No. WO 2007 / 062384), which is hereby incorporated by reference in its entirety and which itself claims the benefit of the following commonly assigned provisional patent applications, each of which is hereby incorporated by reference in its entirety: U.S. Provisional Patent Application Ser. No. 60 / 738,867, for Melt-Phase Polycondensation of Titanium-Catalyzed PET Resins, filed Nov. 22, 2005; U.S. Provisional Patent Application Ser. No. 60 / 739,796, for Polyester Resins for High-Strength Articles, filed Nov. 23, 2005; U.S. Provisional Patent Application Ser. No. 60 / 739,498, for Polyester Resins for High-Efficiency Injection Molding, filed Nov. 23, 2005; and U.S. Provisional Patent Application Ser. No....

AI Technical Summary

Benefits of technology

[0011]Accordingly, it is an object of the present invention to provide polyester resin that is capable of being efficiently formed into low-haze, high-clarity articles.

[0012]It is a further object of the present invention to provide a polyethylene terephthalate resin that can be efficiently formed into high-clarity polyester preforms and bottles.

[0013]It is a further object of the present invention to provide a polyethylene terephthalate resin that can be efficiently formed into high-strength, high-clarity polyester bottles suitable for carbonated soft drinks.

Problems solved by technology

Unfortunately, at normal production rates, most polyester resins cannot be efficiently formed into preforms and bottles that are suitable for hot-fill applications.

Most high-clarity polyester bottles do not possess the necessary dimensional stability to be hot-filled with product at temperatures between about 180° F. and 205° F., especially between about 195° F. and 205° F. In particular, at such elevated temperature conventional polyester bottles exhibit unacceptable shrinkage and haze.

In addition, polyester bottles that package carbonated beverages have been known to suffer stress cracking, which leads to catastrophic failure, or exhibit thermal instability (e.g., thermal creep), which can result in packaging deformations such as (e.g., fill-line drop, base rocking, and label distortion).

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