Cellulose Ester Film Stability Wet Heat Calcium Acid Ratio
Solution Overview
Problem
Cellulose esters used in film and fiber production face challenges in achieving high releasability from supports, heat resistance under wet conditions, and maintaining optical characteristics, with existing techniques often compromising between these properties.
Innovation Solution
A cellulose ester with a specific calcium to sulfuric acid molar ratio, within the range of 0.5 to 1.5, is developed, which enhances releasability, heat resistance, and optical characteristics by adjusting the degree of substitution at various positions and incorporating calcium as a stabilizer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a cellulose ester film is produced by casting with low residual solvent to improve releasability from metal support, then releasability is improved, but heat resistance under wet condition deteriorates
Solution Approach 1:
The patent changes the chemical composition parameters of the cellulose ester by controlling the degree of substitution at 2-, 3-, and 6-positions and the molar ratio of calcium to sulfuric acid. This allows optimization of both releasability and heat resistance under wet condition simultaneously, resolving the contradiction between ease of operation and reliability
Solution Approach 2:
The patent creates a composite cellulose ester structure incorporating calcium ions along with specific substitution patterns. This composite approach enhances the material's overall performance, providing both good releasability from metal supports and improved heat resistance under wet conditions
2Reliability
If the degree of substitution at 2- and 3-positions is increased to improve heat resistance, then heat resistance is improved, but releasability from metal support deteriorates
Solution Approach 1:
The patent optimizes the degree of substitution at 2-, 3-, and 6-positions together with the calcium to sulfuric acid molar ratio. By adjusting these parameters in combination rather than independently, the patent achieves both high heat resistance and good releasability, resolving the contradiction between reliability and ease of operation
3Reliability
If calcium content is increased to improve heat resistance under wet condition, then heat resistance is improved, but optical characteristics deteriorate
Solution Approach 1:
The patent precisely controls the molar ratio of calcium to sulfuric acid within a specific range (0.5 to 1.5) while also optimizing the degree of substitution at different positions. This multi-parameter optimization ensures both improved heat resistance under wet condition and maintained optical characteristics, resolving the contradiction between reliability and manufacturing precision
Data Source
AI summary
The present invention provides a cellulose ester in which heat resistance under wet condition is compatible with both releasability and spinnability even when the amount of the residual solvent is small in a casting process. The cellulose ester fulfills the following formula:0.5<(B)/(A)<1.5wherein (A) and (B) represent the total amount (in terms of molar amount) of residual sulfuric acid in 1 gram of the cellulose ester and the total amount (in terms of molar amount) of calcium contained in 1 gram of the cellulose ester, respectively.