Preservative-Free Pigment Paste with Trivalent Metal Compounds
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing aqueous-based coating compositions, particularly pigment pastes used in tinting systems, face challenges in being free of preservatives and biocides while maintaining resistance to alkaliphilic bacteria, yeasts, and molds, and ensuring a long open time without impairing color characteristics.
Innovation Solution
Incorporation of inorganic compounds of trivalent metals, such as aluminum compounds, with controlled solubility and particle size distribution into pigment pastes, creating a germ-resistant environment at alkaline pH without using biocides or preservatives.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If preservatives and biocides are added to aqueous pigment pastes to prevent microbial infestation, then microbial resistance is improved, but health and environmental protection deteriorates due to vapor pressure and decomposition
Solution Approach 1:
The patent removes preservatives and biocides from the aqueous pigment paste formulation entirely. Instead of adding harmful substances to prevent microbial growth, the invention extracts and eliminates these harmful components while maintaining microbial resistance through alternative means (alkaline pH and inorganic compounds).
Solution Approach 2:
The patent converts the harmful effect of microbial growth into a beneficial challenge by using alkaline pH and inorganic compounds to create an environment where microbes cannot survive. The alkaline conditions, which would normally be problematic, are transformed into a protective barrier against microbial infestation.
2Reliability
If pH value is set to 10 or higher to create germ-resistant environment, then microbial growth is suppressed, but alkaliphilic bacteria, yeasts and fungi can still grow and adapt
Solution Approach 1:
The patent combines multiple protective mechanisms into a composite defense system: alkaline pH (10 or higher) is combined with inorganic compounds (such as calcium aluminate sulfate) to create a synergistic effect. This composite approach addresses the limitation of pH alone by adding another layer of protection that inhibits alkaliphilic microorganisms.
Solution Approach 2:
The inorganic compounds act as intermediary substances that mediate between the alkaline pH environment and the microbial threat. These compounds provide an additional mechanism that interferes with microbial survival in alkaline conditions, preventing adaptation by alkaliphilic organisms.
3Ease of operation
If pigment pastes are stored openly for several weeks to allow mixing, then ease of operation is improved, but microbial infestation increases due to exposure to ambient air
Solution Approach 1:
The patent applies preliminary protective measures by formulating the pigment paste with alkaline pH and inorganic compounds before storage. This pre-established protective barrier prevents microbial infestation during the storage period, allowing the paste to be stored openly for several weeks without contamination.
Solution Approach 2:
The pigment paste is designed to be self-protecting through its inherent alkaline pH and inorganic compound content. The formulation provides its own microbial resistance without requiring external preservatives or biocides, enabling it to withstand exposure to ambient air during storage and mixing operations.
4Reliability
If inorganic compounds of trivalent metals are incorporated to provide germ resistance, then microbial resistance is improved, but manufacturing complexity increases due to controlled solubility and particle size requirements
Solution Approach 1:
The patent utilizes parameter changes in the inorganic compounds, specifically controlling solubility (less than 5 g/l at 20°C) and particle size distribution. By adjusting these parameters, the formulation achieves effective germ resistance while maintaining manufacturability. The controlled solubility ensures the compounds provide protective effects without excessive complexity in production.
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 solution provides stable, VOC-free pigment pastes that resist microbial infestation, maintain color brilliance, and extend open time, suitable for various binder systems without the need for preservatives or biocides.
Implementation Method 1
the inorganic compound of a trivalent metal with a solubility of less than 5 g/l at 20° C. in water... creates a germ-resistant environment at alkaline pH
Implementation Method 2
the pH value of the pigment paste is usually set to a value of 10 or higher, creating an environment in which many bacteria and yeasts as well as the majority of fungi cannot grow
Data Source
AI summary
An aqueous composition configured as a pigment paste for tinting systems, the composition comprising an inorganic compound of a trivalent metal with a solubility of less than 5 g/l at 20° C. in water.