Recycled PET Methacrylated Compounds for Coatings
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Solution Overview
Problem
Current methods for producing (meth)acrylated compounds from recycled PET result in low recycled content and inadequate pigment wetting and ink-water balance in energy curable coating compositions and inks.
Innovation Solution
A process involving the depolymerization of thermoplastic polyester with polyhydric alcohols and triglycerides, followed by reaction with fatty acids and (meth)acrylating compounds, to produce (meth)acrylated compounds with a higher PET content and improved pigment wetting and ink-water balance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If glycolysis of PET is used for depolymerization with high glycol/PET molar ratio (at least 2), then the depolymerization reaction proceeds efficiently, but the recycled PET content in the final product becomes low
Solution Approach 1:
The invention changes the key parameter of glycol/PET molar ratio from the conventional at least 2 to less than 2 (specifically 0.5-1.5), which fundamentally alters the reaction pathway and product distribution to achieve both efficient depolymerization and high recycled content retention
2Ease of manufacture
If conventional polyester acrylates are used in energy curable coating compositions, then the coating process is simple, but pigment wetting and ink-water balance are inadequate
Solution Approach 1:
The invention creates composite (meth)acrylated compounds that integrate recycled PET segments with fatty acid and triglyceride moieties, producing a multi-functional material that simultaneously provides good processability and superior pigment wetting and ink-water balance properties
Solution Approach 2:
The invention introduces specific functional groups (fatty acid chains and triglyceride structures) at localized positions within the polymer chain to enhance pigment wetting and ink-water balance, while maintaining the overall simplicity of the coating application process
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The process achieves (meth)acrylated compounds with a higher PET content and enhanced pigment wetting and ink-water balance, facilitating their incorporation into coating compositions and inks with improved performance.
Implementation Method 1
Reacting a thermoplastic polyester with (a1) at least one polyhydric alcohol... to obtain a depolymerization product A
Implementation Method 2
Reacting the depolymerization product A with (b1) at least one fatty acid and/or (b2) at least one polybasic carboxylic acid... to provide a polyester polyol B
Implementation Method 3
Reacting the polyester polyol B with at least one (meth)acrylating compound (c) to provide a methacrylated compound (I)
Data Source
AI summary
The present invention relates to a process for preparing a polyester (meth)acrylate resin (I), said process comprising the steps of: (a) Reacting a thermoplastic polyester with (a1) at least one polyhydric alcohol and, optionally, with (a2) at least one triglyceride, wherein the molar ratio of triglyceride to thermoplastic polyester is between 0 and 0.3, and the molar ratio of polyhydric alcohol to thermoplastic polyester is at most 1.9 to obtain a depolymerization product A that has a hydroxyl number within the range of from 200 to 800 mg KOH/g; (b) Reacting the depolymerization product A with (b1) at least one fatty acid and/or (b2) at least one polybasic carboxylic acid and, optionally, with (b3) at least one polyhydric alcohol to provide a polyester polyol B; (c) Reacting the polyester polyol B with (c) at least one (meth)acrylating compound to provide a (meth)acrylated compound (I), wherein the weight ratio of fatty acid (b1) to the depolymerization product A is between 0 and 0.6, wherein the weight ratio of polybasic carboxylic acid (b2) to the depolymerization product A is less than 0.3, wherein the weight ratio of (meth)acrylating compounds (c) to the depolymerization product A is between 0.1 and 0.8, and wherein the (meth)acrylated compound (I) that is obtained has a number average molecular weight (Mn) of between 500 and 5,000 Dalton. Typically PET is used as starting material. Typically compounds (I) of the invention have a PET content of at least 15 wt %, preferably at least 25 wt %. The present invention also relates to (meth)acrylated compounds (I) thus obtained and to coating compositions and inks based upon these materials. Materials of the invention allow the use of a high amount of PET waste. Inks and coatings prepared from these materials exhibit an excellent pigment wetting and/or ink-water balance.