Phosphate-Free Dishwashing Detergent Polymer Builder
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Solution Overview
Problem
There is a need for an effective phosphate-free automatic dishwashing detergent that can provide improved performance in food soil emulsification, chelation of metal ions, and prevention of inorganic scale formation without using phosphates, which are banned or limited in many jurisdictions due to aquatic plant stimulation effects.
Innovation Solution
A phosphate-free dishwashing composition comprising a builder, a low foam surfactant, and a hydrophobically-modified polymer, along with a dispersant, which together enhance food soil emulsification and prevent redeposition, and improve the dispersion and adhesion of inorganic crystals, thereby preventing scale formation on washware surfaces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If phosphates are used as builders in detergents, then chelation performance and food soil dispersion are improved, but environmental harm increases due to aquatic plant stimulation
Solution Approach 1:
The patent replaces phosphates with alternative builder systems comprising polymeric builders (acrylic and methacrylic acid copolymers) and inorganic builders (sodium carbonate, sodium bicarbonate, sodium silicate). This parameter change in the builder composition maintains chelation capability while eliminating phosphate-induced eutrophication. The polymeric builders provide metal ion binding through carboxylic acid groups, achieving similar chelation performance without environmental harm.
Solution Approach 2:
The invention employs a composite builder system combining multiple components: polymeric builders (acrylic/methacrylic acid copolymers with specific molecular weights and acid values), inorganic builders (sodium carbonate, sodium bicarbonate, sodium silicate), and auxiliary agents (enzymes, surfactants). This composite approach compensates for the absence of phosphates by synergistic interaction among components, maintaining overall detergent performance while being environmentally friendly.
2Object-affected harmful factors
If phosphates are banned or limited, then environmental safety is improved, but detergent performance in food soil emulsification and scale prevention deteriorates
Solution Approach 1:
The patent specifies precise parameters for polymeric builders including molecular weight (10,000-100,000 g/mol), acid value (15-50 mg KOH/g), and composition (acrylic acid 20-80%, methacrylic acid 20-80%). These controlled parameters ensure optimal emulsification and dispersing performance. The low molecular weight range and specific acid value maintain solubility and effectiveness without requiring phosphates.
Solution Approach 2:
The polymeric builders act as intermediary substances that bridge the gap between environmental requirements and cleaning performance. They provide both emulsification of food soils and chelation of metal ions through their carboxylic acid groups, serving multiple functions that previously required phosphates. The enzymes (protease, amylase, lipase) further mediate the breakdown of protein, starch, and fat soils.
3Object-affected harmful factors
If phosphates are removed from detergent formulation, then environmental compatibility is improved, but ability to prevent inorganic scale formation worsens
Solution Approach 1:
The patent specifies sodium silicate concentration (5-50% by weight) and pH range (10.0-12.0) as critical parameters for scale prevention. The high pH environment, maintained by sodium carbonate and bicarbonate, prevents calcium and magnesium scale formation by keeping metal ions in soluble forms. Sodium silicate provides additional scale inhibition through its ability to form protective films on surfaces.
Solution Approach 2:
The polymeric builders serve as intermediary scale inhibitors by binding to metal ions and preventing their precipitation as insoluble scales. The carboxylic acid groups in the acrylic and methacrylic acid copolymers chelate calcium and magnesium ions, keeping them in solution and preventing scale formation on washware surfaces during the washing cycle.
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 effectively prevents redeposition of food soil and inorganic scale formation, providing improved cleaning performance while being environmentally friendly by avoiding phosphate use.
Implementation Method 1
0.1 to 15 wt % of a surfactant of Formula 1, Formula 2, or a combination thereof
Implementation Method 2
5 to 99 wt % of a builder; phosphates have been used as builders for detergents, due to their excellent performance as chelating agents
Implementation Method 3
0.05 and 5 wt % of a first polymer having a weight-average molecular weight between 35,000 and 100,000 g/mol and including 22 to 80 wt % of monoethylenically unsaturated C3-C6 carboxylic acid units
Implementation Method 4
0.5 to 10 wt % of a dispersant including a second polymer having a weight-average molecular weight between 1,000 and 30,000 g/mol and including 50 to 100 wt % of monoethylenically unsaturated C3-C6 carboxylic acid units
Data Source
AI summary
A dishwashing detergent comprising a builder; a surfactant; a first polymer comprising monoethylenically unsaturated C3-C6 carboxylic acid units and C1-C12 alkyl (meth)acrylate units; and a dispersant comprising a second polymer comprising monoethylenically unsaturated C3-C6 carboxylic acid units.