High Purity Itaconic Acid in Conjugated-Diene Copolymer Latex
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Solution Overview
Problem
The challenge is to produce a conjugated-diene-based copolymer latex using itaconic acid that maintains dispersion stability while allowing for easy control of particle size, as existing methods with itaconic acid often face difficulties in achieving target particle sizes, affecting operational stability during production.
Innovation Solution
The method involves using itaconic acid with no peak detected between 12 and 14 minutes in chromatogram measurements, indicating high purity, which is essential for producing a conjugated-diene-based copolymer latex with excellent water dispersibility and controlled particle size, achieved through emulsion-polymerizing specific monomer components and conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If itaconic acid is used to improve dispersion stability of conjugated-diene-based copolymer latex, then dispersion stability is improved, but particle size control becomes difficult
Solution Approach 1:
The patent applies parameter changes by precisely controlling the purity level of itaconic acid (specifying no peak between 12-14 minutes in chromatogram) and adjusting monomer component ratios (conjugated diene 10-80 mass%, ethylenically unsaturated carboxylic acid 2-15 mass%, other copolymerizable monomer 5-88 mass%). This resolves the contradiction by showing that with high purity itaconic acid, both dispersion stability and particle size control can be achieved simultaneously, whereas conventional lower purity itaconic acid causes particle size control difficulties.
2Productivity
If particle size is reduced to improve binder performance, then binder performance is improved, but operational stability during production deteriorates
Solution Approach 1:
The patent applies preliminary action by pre-purifying the itaconic acid monomer before polymerization to eliminate impurities that would cause operational instability. The chromatogram specification (no peak between 12-14 minutes) ensures that the monomer is prepared in advance with the required purity, preventing production issues during the actual polymerization process. This allows small particle sizes to be produced with both high binder performance and operational 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
This approach results in a conjugated-diene-based copolymer latex with enhanced operational stability and controlled particle size, improving binder performance and stability during production.
Implementation Method 1
emulsion-polymerizing specific monomer components and conditions
Implementation Method 2
copolymerization
Data Source
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Figure 2
AI summary
A method for producing a conjugated-diene-based copolymer latex comprises a step of emulsion-polymerizing monomer components including 10 to 80 mass% of an aliphatic conjugated-diene-based monomer, 0.5 to 15 mass% of an ethylenically unsaturated carboxylic acid monomer, and 5 to 89.5 mass% of another copolymerizable monomer, wherein the ethylenically unsaturated carboxylic acid monomer includes an itaconic acid having no peak detected at a detection time between 12 minutes and 14 minutes in a chromatogram measured under the following measurement conditions: <Measurement conditions> With use of a liquid chromatograph-corona charged particle detector, measurement is performed with a sample concentration of 1 mass%, pure water as a solvent, a column temperature of 40°C, a formic acid aqueous solution/acetonitrile as a mobile phase, and a liquid feed rate of 0.2 ml/min.