Recycled Monomer Polyester Resin for Powder Coating Clarity

Solution Overview

Problem

Existing polyester resins using recycled bis-2-hydroxyethyl terephthalate monomers face issues with deteriorated color quality and transparency due to high content, leading to unsuitable properties for powder coatings.

Innovation Solution

A polyester resin is formulated by copolymerizing recycled bis-2-hydroxyethyl terephthalate with dicarboxylic acid and polyhydric alcohol, controlling the recycled monomer content between 1 to 50 parts by weight, to maintain uniform quality and properties suitable for powder coatings.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of repair

If high content of recycled bis-2-hydroxyethyl terephthalate is used in polyester resin, then recycling rate is improved, but color quality and transparency deteriorate

Engineering Contradiction:

Improverecycling rateVSAvoidcolor quality

Core Design Contradiction:

Ease of repairVSManufacturing precision

Solution Approach 1:

The patent applies parameter changes by precisely controlling the content of recycled monomer units in the polyester resin to be 1-50 parts by weight per 100 parts by weight of total polyester resin. This quantitative parameter control optimizes the balance between recycling rate and color quality, preventing excessive yellowing while maximizing waste plastic utilization.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite polyester resin system that combines recycled bis-2-hydroxyethyl terephthalate with virgin monomers and other polyester components. This composite approach allows the recycled portion (1-50 parts by weight) to contribute to sustainability while the overall composition maintains uniform color quality and transparency suitable for powder coatings.

Inventive Principle:

Principle #40Composite materials

2Ease of repair

If high content of recycled bis-2-hydroxyethyl terephthalate is used in polyester resin, then recycling rate is improved, but transparency deteriorates

Engineering Contradiction:

Improverecycling rateVSAvoidtransparency

Core Design Contradiction:

Ease of repairVSIllumination intensity

Solution Approach 1:

The patent applies parameter changes by precisely controlling the content of recycled monomer units in the polyester resin to be 1-50 parts by weight per 100 parts by weight of total polyester resin. This quantitative parameter control optimizes the balance between recycling rate and transparency, preventing excessive yellowing while maximizing waste plastic utilization.

Inventive Principle:

Principle #35Parameter changes

3Manufacturing precision

If recycled monomers are used to maintain uniform quality, then manufacturing consistency is improved, but recycling effectiveness is reduced

Engineering Contradiction:

Improvequality uniformityVSAvoidrecycling effectiveness

Core Design Contradiction:

Manufacturing precisionVSEase of repair

Solution Approach 1:

The patent applies parameter changes by precisely controlling the content of recycled monomer units in the polyester resin to be 1-50 parts by weight per 100 parts by weight of total polyester resin. This quantitative parameter control optimizes the balance between recycling rate and color quality, preventing excessive yellowing while maximizing waste plastic utilization.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite polyester resin system that combines recycled bis-2-hydroxyethyl terephthalate with virgin monomers and other polyester components. This composite approach allows the recycled portion (1-50 parts by weight) to contribute to sustainability while the overall composition maintains uniform color quality and transparency suitable for powder coatings.

Inventive Principle:

Principle #40Composite materials

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 resulting polyester resin maintains excellent mechanical strength, transparency, and impact resistance, making it suitable for powder coatings while utilizing recycled materials effectively.

Implementation Method 1

a polyester resin polymerized from 1) recycled bis-2-hydroxyethyl terephthalate, 2) acid comprising dicarboxylic acid or derivatives thereof, and 3) polyhydric alcohol different from the recycled bis-2-hydroxyetyl terephthalate, and having a structure in which a part derived from the bis-2-hydroxyethyl terephthalate, a part derived from the dicarboxylic acid or derivatives thereof, and a part derived from the polyhydric alcohol are repeated

Methodology Applied

Scientific EffectCopolymerization: Chemical Bonding

Data Source

PatentEP4603526A1Polyester resin containing recycled monomer and powder coating composition containing same

Publication Date: 2025.08.20 SK CHEMICALS CO LTD

AI summary

This invention relates to polyester resin comprising recycled monomers and a powder coating composition comprising the same.