Polyester Copolymer Dye Transfer Inhibition in Laundry

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Solution Overview

Problem

Traditional dye transfer inhibitors are ineffective in preventing the transfer of particulate dyes like indigo during laundry, especially in mixed fabric loads, and can cause stability issues with other laundry additives, leading to fading and uneven dye appearance in denim.

Innovation Solution

Incorporating a polyester copolymer at a level of 0.1% to 5% combined with a cellulase enzyme in detergent compositions to inhibit dye transfer and prevent fading, while maintaining the appearance of denim.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional DTI polymers (PVP, PVNO, PVP/PVI, PVP/PVNO) are used to inhibit direct dye transfer, then direct dye transfer is reduced, but they are ineffective against particulate dyes like indigo and cause stability issues with other laundry additives

Engineering Contradiction:

Improvedye transfer inhibition effectivenessVSAvoidcompatibility with different dye types and laundry additives

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent changes the chemical composition parameters of the polymer by using a copolymer with specific ratios of vinyl pyrrolidone (20-80 mol%) and vinyl acetate (20-80 mol%), molecular weight (10,000-1,000,000 g/mol), and hydrolysis degree (0-50%). This parameter optimization enables the polymer to effectively inhibit both direct dyes and particulate dyes like indigo while maintaining stability with laundry additives, resolving the contradiction between effectiveness and versatility.

Inventive Principle:

Principle #35Parameter changes

2Ease of manufacture

If cellulase enzyme is used to create worn look on denim, then aesthetic effect is achieved, but it causes unintended fading and compounds dye transfer in mixed color loads

Engineering Contradiction:

Improveaesthetic effect on denimVSAvoidunintended fading and dye transfer

Core Design Contradiction:

Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The patent applies preliminary anti-action by using the optimized polyester copolymer to pre-establish protection against dye transfer before the cellulase enzyme can cause harmful effects. The copolymer forms a protective barrier on the fabric that prevents dye release and redeposition, allowing controlled aesthetic effects while counteracting the harmful fading and dye transfer that would otherwise occur during washing.

Inventive Principle:

Principle #9Preliminary anti-action

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 combination effectively reduces dye transfer of particulate dyes like indigo, maintaining the color and appearance of denim garments across multiple wash cycles.

Implementation Method 1

Certain polymers, generally known as dye transfer inhibitor ('DTI') polymers, have traditionally been used in laundry compositions to address the dye transfer problem

Methodology Applied

Scientific EffectAdsorption: Adsorption

Implementation Method 2

Cellulase enzymes are known to release dye from unwashed denim to give denim an uneven dye appearance, or so-called 'worn' look on denim

Methodology Applied

Scientific EffectEnzymatic degradation: Enzyme

Implementation Method 3

indigo is a so-called Leuco dye that soluble in the reduced form for dyeing fabrics that oxidizes in air to convert to the insoluble, blue colored dye

Methodology Applied

Scientific EffectOxidation: Oxidation

Data Source

PatentUS20210095229A1Fabric care compositions that include a copolymer and related methods

Publication Date: 2021.04.01 PROCTER & GAMBLE CO

AI summary

Fabric care compositions that include a linear copolymer. Methods and uses relating to such compositions and/or graft copolymers.