Neutral Polymer Color via Organic Dye Extraction
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Solution Overview
Problem
Current methods for producing polymers, particularly polyesters, face challenges in achieving neutral color tones due to yellowish discoloration from thermal and oxidative degradative reactions, and the use of cobalt compounds as colorants leads to catalytic issues and turbidity problems, especially in food packaging, where independent adjustment of color values and low metal content are essential.
Innovation Solution
A method involving the addition of blue and/or red organic dyes at specific stages of the polymer production process, allowing for independent adjustment of 'a' and 'b' color values in the Hunter L, a, b color space, with a total dye concentration of no more than 3 ppm, and using a mixture ratio of at least 50% blue dye by weight to achieve a neutral color tone, replacing cobalt compounds and reducing metal content.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If cobalt compounds are used as colorants to achieve neutral color tone, then color neutrality is improved, but metal content increases and catalytic issues occur
Solution Approach 1:
The patent extracts and removes cobalt compounds from the polymer production process, replacing them with organic dyes. This eliminates the metal content issue while maintaining color neutrality through carefully selected organic colorants that do not introduce harmful metals into the final polymer product.
Solution Approach 2:
The patent changes the chemical parameters by substituting inorganic cobalt compounds with organic dye molecules. This parameter change allows achieving the same color neutralization effect without the adverse catalytic and metal content issues associated with cobalt, thereby resolving the contradiction between color neutrality and metal content reduction.
2Manufacturing precision
If cobalt compounds are used as colorants, then color neutrality is improved, but turbidity problems occur
Solution Approach 1:
The patent removes cobalt compounds from the system and replaces them with organic dyes. This extraction eliminates the source of turbidity problems while preserving the color neutralization function, as organic dyes do not exhibit the same turbidity-inducing side effects as cobalt compounds.
3Manufacturing precision
If reaction temperature is lowered to minimize degradative reactions, then color quality is improved, but reaction velocity decreases
Solution Approach 1:
The patent changes the chemical environment by introducing organic dyes that can effectively neutralize yellow discoloration even at standard reaction temperatures. This parameter change in the chemical composition allows maintaining both high reaction velocity and good color quality, eliminating the need to compromise temperature for color improvement.
4Manufacturing precision
If blue dyes are added to shift yellow base tone, then visual color neutrality is improved, but independent adjustment of color values becomes difficult
Solution Approach 1:
The patent segments the color adjustment function into independent control of the a and b color values. By using organic dyes with specific spectral characteristics, the patent enables separate and independent adjustment of these color parameters, allowing precise control over both the red-green (a) and yellow-blue (b) dimensions without interference between them.
Solution Approach 2:
The patent changes the approach to color control by selecting organic dyes that allow independent manipulation of color space parameters. This enables precise, separate adjustment of a and b values, transforming the color adjustment process from a coupled system to an independently controllable one, thereby reducing complexity.
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 method allows for precise adjustment of color values, reducing turbidity and metal content, ensuring compliance with food regulations while minimizing costs, and maintaining a neutral color tone in polymers, particularly suitable for packaging materials.
Implementation Method 1
the addition of blue and/or red organic dyes... allowing for independent adjustment of 'a' and 'b' color values in the Hunter L, a, b color space
Data Source
AI summary
A method is disclosed for producing polymers with a neutral color tone, wherein a blue and red dye are added before entry into the last polyreaction stage, wherein adjustment of a neutral color tone of the polymer, using a total dye concentration in the polymer of no more than 3 ppm and a proportion of the blue dye in the resulting dye mixture of at least 50% by weight, occurs through independent adjustment of a and b color values in the Lab color space by determination of a and b color values of the polymer without addition of dyes, establishment of the total dye concentration depending on the b-value shift to be achieved, establishment of the required mixture ratio of the colors red and blue depending on the a-value shift to be achieved, and metering of the established content of dye mixture into the reaction mixture.