High-Concentration Aqueous Biocide Stability via pH and Ion Control
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Solution Overview
Problem
Existing aqueous biocide compositions containing 1,2-benzisothiazolin-3-one (BIT) are not sufficiently stable, especially at higher concentrations and cold temperatures, and often require the use of volatile organic compound (VOC) containing solvents or glycol-based solvents, which are not cost-effective or environmentally friendly.
Innovation Solution
An aqueous biocide composition with a higher content of 1,2-benzisothiazolin-3-one (9 wt. % to 20 wt. %) is developed, characterized by a pH value of 9.5 to 11.9 and a molar fraction of sodium ions between 15 to 45 mol %, using sodium and potassium hydroxide as alkalizing agents, and containing more than 60 wt. % water, thereby avoiding VOC-containing solvents and glycol-based solvents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If aqueous BIT solutions are prepared at higher concentrations to improve stability and eliminate solvents, then environmental friendliness and cost-effectiveness are improved, but storage stability deteriorates due to solid separation
Solution Approach 1:
The patent changes the chemical parameters of the aqueous BIT solution by precisely controlling the pH value (9.5-11.9) and the molar ratio of sodium to potassium ions (15-45 mol%). This parameter optimization prevents solid separation and maintains storage stability even at high BIT concentrations (9-20 wt%), thereby resolving the contradiction between concentration and stability.
2Stability of the object's composition
If glycol-based solvents are added to improve stability at cold temperatures, then low-temperature stability is improved, but environmental friendliness and cost-effectiveness deteriorate
Solution Approach 1:
The patent extracts and eliminates glycol-based solvents from the formulation entirely. Instead of adding harmful solvents to achieve low-temperature stability, the invention achieves the same stability through optimized aqueous solution parameters (pH 9.5-11.9 and controlled ion composition), thereby removing the harmful substance while maintaining the desired performance.
Solution Approach 2:
The patent replaces expensive and environmentally harmful glycol-based solvents with a cost-effective, environmentally friendly aqueous solution system. The disposable water-based formulation with controlled pH and ion composition provides the necessary stability without the drawbacks of persistent organic solvents.
3Object-affected harmful factors
If conventional aqueous BIT solutions are used to avoid solvents, then environmental friendliness is improved, but stability at higher concentrations and cold temperatures deteriorates
Solution Approach 1:
The patent optimizes the chemical parameters of the aqueous solution by controlling pH (9.5-11.9) and ion composition (sodium to potassium molar ratio of 15-45%). These parameter changes enable the aqueous solution to maintain stability at higher BIT concentrations (9-20 wt%) without requiring organic solvents, thus resolving the contradiction between solvent avoidance and concentration stability.
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 improved stability, ease of dosing, and enhanced viscosity, with minimal solid separation during extended storage, even at lower temperatures, making it suitable for various water-based products.
Implementation Method 1
a dissolved alkalizing agent, containing 0.95 to 1.05 mol sodium and potassium hydroxide, each based on one mol of the 1,2-benzisothiazolin-3-one contained as component (a)
Implementation Method 2
a dissolved alkalizing agent, containing 0.95 to 1.05 mol sodium and potassium hydroxide
Implementation Method 3
has a pH value in the range of pH 9.5 to pH 11.9
Data Source
AI summary
The invention relates to an aqueous biocide composition, containing the following components: (a) 9 wt. % to 20 wt. % 1,2-benzisothiazolin-3-one, (b) a dissolved alkalizing agent, containing 0.95 to 1.05 mol sodium and potassium hydroxide, each based on one mol of the 1,2-benzisothiazolin-3-one present as component (a), and (c) more than 60 wt. % water. The biocide composition is characterized in that the composition: (i) has a pH value in the range of pH 9.5 to pH 11.9, and (ii) the molar fraction of sodium ions, based on the sodium and potassium ions present in the composition, is in the range of 15 to 45 mol %. The invention furthermore relates to the use of these biocide compositions for preserving water-based products of all kinds, such as cleaning and household products, plastic dispersions, paints, plasters, adhesives, sealing compounds, paper coating compounds, textile softening and sizing agents, detergent base materials, surfactants, polishing agents, spinning baths, cooling lubricants, leather treatment agents, and silicone and bitumen emulsions.