Bio-based MEG Composition for Transparent PET Bottles

The patent changes the chemical composition parameters of MEG by incorporating specific C3-C12 1,2-diols (1,2-propanediol, 1,2-butanediol, 1,2-pentanediol) in controlled amounts (1-5000 ppm each). This compositional modification transforms the optical properties of the final PET product, achieving superior transparency while maintaining the condensation reaction process with terephthalic acid.

The patent creates a composite MEG composition by combining conventional MEG with minor amounts of specific diol components derived from bio-based sources. This composite approach allows the mixture to exhibit enhanced optical properties (transparency) while maintaining the fundamental chemical reactivity needed for PET synthesis, effectively merging the benefits of established processing with improved product properties.

The patent extracts and isolates specific diol components (C3-C12 1,2-diols) from bio-based feedstocks and incorporates them in precisely controlled concentrations (1-5000 ppm). This extraction approach allows the beneficial optical properties to be achieved while avoiding the need to completely redesign the production process, as the core condensation reaction with terephthalic acid remains unchanged.

The patent applies local quality modification by introducing specific diol components only in minor amounts (trace concentrations) rather than completely replacing MEG. This localized modification targets the specific property (transparency) that needs improvement while leaving the bulk composition and fundamental reaction pathway intact, thereby minimizing process complexity.