Stable Bromourea Preparation via Segmented Chlorination

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Solution Overview

Problem

Existing methods for preparing bromourea solutions suffer from limited stability, especially at elevated temperatures, making them unsuitable for transportation and application in biocidal applications.

Innovation Solution

A method involving the reaction of a urea salt or adduct with an oxidizer like NaOCl, in a molar excess, to form a stable aqueous acidic bromourea composition, which can be further brominated by adding a bromide source, allowing for the creation of a biocidal solution with enhanced stability and efficacy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If direct bromination of concentrated urea solution with Br2 is used to prepare bromourea, then biocidal activity is achieved, but stability under elevated temperatures deteriorates

Engineering Contradiction:
Improvebiocidal activityVSAvoidstability at elevated temperatures
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The invention divides the bromination process into two separate stages: first preparing a stable chlorourea solution from urea and chlorine, then converting it to bromourea by adding sodium bromide. This segmentation allows the intermediate chlorourea to be stored and transported stably, and only converts to the active bromourea form when needed at the application site, resolving the contradiction between biocidal activity and thermal stability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention performs preliminary preparation of chlorourea solution in advance, which can be stored and transported stably. The conversion to bromourea is then activated preliminarily at the application site by adding sodium bromide, ensuring the biocidal agent is formed just before use to maintain both stability during transport and activity during application.

Inventive Principle:
Principle #10Preliminary action

2Ease of operation

If chlorourea solution is prepared and transported to treatment site, then transportation is enabled, but stability at higher temperatures deteriorates

Engineering Contradiction:
Improvetransportation capabilityVSAvoidstability at higher temperatures
Core Design Contradiction:
Ease of operationVSStability of the object's composition

Solution Approach 1:

The invention changes the chemical composition parameters by using a specific molar ratio of urea to chlorine (at least 2:1, preferably at least 5:1) to prepare the chlorourea solution. This parameter optimization ensures the solution has sufficient stability for transportation while maintaining the capability to convert to active bromourea at the application site by adding sodium bromide.

Inventive Principle:
Principle #35Parameter changes

3Stability of the object's composition

If bromourea solution is formed on-site by combining stable aqueous solutions, then stability during transportation is improved, but process complexity increases

Engineering Contradiction:
Improvestability during transportationVSAvoidprocess complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The invention uses chlorourea solution as an intermediary substance that can be stably prepared and transported. At the application site, sodium bromide is added as another intermediary to convert the stable chlorourea into the active bromourea form. This use of intermediaries allows the system to maintain stability during transportation while enabling simple on-site conversion through a single mixing step.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 method produces a stable bromourea solution that maintains its biocidal properties, effectively reducing bacterial biofilms and providing a safer, more efficient means of application by forming the solution on-site, avoiding the drawbacks of previous methods.

Implementation Method 1

reacting a salt or adduct of urea of the general structure A-U with an oxidizer which is NaOCl

Methodology Applied
Scientific EffectOxidation: Oxidation

Implementation Method 2

reacting said salt or adduct with NaOCl, thereby forming chlorourea, and adding to said chlorourea a solution comprising NaBr, thereby obtaining a composition comprising bromourea

Methodology Applied
Scientific EffectChemical reaction: Chemical Bonding

Data Source

PatentEP2619169B1Method for preparing bromourea
Publication Date: 2018.09.12 BROMINE COMPOUNDS

AI summary

The invention provides a process for manufacturing biocidal compositions containing bromourea derivatives, including the reaction of salts or adducts of the urea derivatives with an oxidizer.