Alkaline Laundry Detergent Polyester Stability
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Solution Overview
Problem
Existing alkaline liquid laundry detergent compositions face challenges with the stability and solubility of polyesters in alkaline environments, particularly when triethanolamine is present, leading to reduced soil release performance and turbidity issues.
Innovation Solution
A composition comprising at least 1 wt% triethanolamine, 5 wt% non-soap surfactant, and 0.5 wt% of a specific polyester with a defined molecular structure, along with additional surfactants and polyalkoxylated polyethyleneimine, which is prepared through a two-step process involving transesterification and polycondensation, ensuring stability and solubility in alkaline conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If polyesters are used in alkaline liquid laundry detergent compositions containing triethanolamine, then soil release properties are improved, but stability is worsened due to alkaline hydrolysis catalyzed by triethanolamine
Solution Approach 1:
The patent modifies the chemical structure parameters of the polyester by incorporating specific cyclic carbonate units (formula I) with defined ratios of ethylene oxide and propylene oxide groups. This structural parameter change makes the polyester resistant to alkaline hydrolysis while preserving soil release properties. The cyclic carbonate structure with its specific molecular architecture prevents degradation by triethanolamine-catalyzed hydrolysis.
Solution Approach 2:
The invention creates a composite polyester structure combining different structural units: cyclic carbonate units (formula I), polycarbonate units (formula II), and polyester units (formula III). This composite structure integrates the hydrolysis resistance of cyclic carbonate units with the soil release functionality of the overall polyester architecture, achieving both stability and performance.
2Reliability
If polyesters are incorporated into alkaline heavy duty washing liquids, then soil release power is enhanced, but solubility is worsened leading to turbidity
Solution Approach 1:
The patent optimizes the molecular weight and structural composition parameters of the polyester to achieve solubility in alkaline media. The specific ratio of cyclic carbonate units (formula I) containing ethylene oxide and propylene oxide groups, combined with polycarbonate and polyester units, creates a molecular structure that maintains solubility while providing effective soil release power in heavy duty washing liquids.
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 composition achieves enhanced stability, solubility, and soil release properties, maintaining effective washing performance even after storage, with reduced foaming and improved handling characteristics.
Implementation Method 1
a two-step process involving transesterification and polycondensation
Implementation Method 2
a two-step process involving transesterification and polycondensation
Implementation Method 3
triethanolamine, which is useful to neutralise anionic surfactants for use in alkaline compositions
Implementation Method 4
triethanolamine also catalyses the alkaline hydrolysis of many polyesters otherwise suitable for use in detergents
Data Source
AI summary
An alkaline liquid laundry detergent composition comprising at least 1 wt% triethanolamine, at least 5 wt% non-soap surfactant and at least 0.5 wt% of a polyester according to the following formula (I) wherein R1 and R2 independently of one another are X-(OC2H4)n-(OC3H6)m wherein X is C1-4 alkyl, the -(OC2H4) groups and the -(OC3H6) groups are arranged blockwise and the block consisting of the -(OC3H6) groups is bound to a COO group or are HO-(C3H6), n is based on a molar average a number of from 12 to 120, preferably 40 to 50, m is based on a molar average a number of from 1 to 10, and a is based on a molar average a number of from 4 to 9. The inventive compositions comprise polyesters that have an advantageous stability in their alkaline environment and also possess advantageous soil release properties.