Cyanogen Halide Production via Excess Cyanide
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Solution Overview
Problem
Current methods for producing cyanate ester compounds face challenges in achieving high-purity and high-yield production due to issues with unreacted halogen and cyanide residues, leading to side reactions and insufficient thermal and flame retardant properties in the final products.
Innovation Solution
A method involving the controlled reaction of hydrogen cyanide or metal cyanide with a halogen molecule, where the molar ratio is optimized to suppress side reactions, and the reaction is terminated within a specific pH and temperature range to produce a cyanogen halide, which is then used to react with a hydroxy-substituted aromatic compound in the presence of a basic compound to form a cyanate ester compound.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the reaction is terminated to prevent unreacted hydrogen cyanide or chlorine from remaining, then safety is improved, but it is extremely difficult to control the reaction such that neither unreacted hydrogen cyanide nor unreacted chlorine remains
Solution Approach 1:
The invention changes the reaction parameters by using an aqueous solution system with controlled pH and temperature, and by using a specific molar ratio of metal cyanide to halogen (1:1.05 to 1:1.2), thereby achieving both safety and reaction control precision simultaneously
Solution Approach 2:
The invention introduces water as an intermediary solvent and uses the aqueous solution environment to mediate the reaction between metal cyanide and halogen, which helps control the reaction progress and prevent excessive accumulation of unreacted hazardous substances
2Manufacturing precision
If metal cyanide is used in equimolar ratio or less than halogen to produce cyanogen halide, then the composition of cyanogen halide-containing solution can be controlled, but unreacted halogen remains in the reaction system leading to side reactions
Solution Approach 1:
The invention uses a slight excess of metal cyanide (molar ratio 1:1.05 to 1:1.2 relative to halogen) to ensure complete consumption of halogen and prevent unreacted halogen from causing side reactions, while maintaining good composition control
3Object-generated harmful factors
If hydrogen cyanide or metal cyanide is used in excessive amount to ensure complete reaction of halogen, then unreacted halogen is minimized, but a large amount of unreacted hydrogen cyanide or metal cyanide remains in the reaction system
Solution Approach 1:
The invention optimizes the molar ratio parameter to a specific range (1:1.05 to 1:1.2) and controls reaction conditions (aqueous solution, pH, temperature) to achieve the minimum excess of metal cyanide needed for complete halogen consumption, thereby minimizing waste
4Productivity
If conventional methods are used to produce cyanate ester compound, then production can proceed, but high-purity and high-yield production is difficult to achieve due to unreacted halogen and cyanide residues
Solution Approach 1:
The invention performs preliminary action by completely consuming halogen through optimized molar ratio and reaction conditions before the cyanate ester compound formation step, thereby preventing side reactions and ensuring high purity and high yield in the final product
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
This approach enables the efficient production of high-purity cyanate ester compounds with improved thermal expansion, flame retardance, and moisture resistance, suitable for advanced polymer materials.
Implementation Method 1
contacting a halogen molecule with an aqueous solution containing hydrogen cyanide and/or a metal cyanide, so that the hydrogen cyanide and/or the metal cyanide is allowed to react with the halogen molecule in a reaction solution to obtain the cyanogen halide
Implementation Method 2
reacting the cyanogen halide with a hydroxy-substituted aromatic compound in the presence of a basic compound to form a cyanate ester compound
Data Source
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AI summary
Upon production of a cyanate ester compound, it is an object of the present invention to provide a method for efficiently producing a cyanogen halide with suppressed side effects, and a method for producing a high-purity cyanate ester compound at a high yield. A method for producing the cyanogen halide, which includes a cyanogen halide-producing step of contacting a halogen molecule with an aqueous solution containing hydrogen cyanide and/or a metal cyanide, so that the hydrogen cyanide and/or the metal cyanide is allowed to react with the halogen molecule in the reaction solution to obtain the cyanogen halide, wherein, in the cyanogen halide-producing step, more than 1 mole of the hydrogen cyanide or the metal cyanide is used based on 1 mole of the halogen molecule, and when an amount of substance of an unreacted hydrogen cyanide or an unreacted metal cyanide is defined as mole (A) and an amount of substance of the generated cyanogen halide is defined as mole (B), the reaction is terminated in a state in which (A) : (A) + (B) is between 0.00009 : 1 and 0.2 : 1.