Rosin Ester Oxidative Stability and Color Control
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Solution Overview
Problem
Existing rosin esters often exhibit poor oxidative stability and are colored, making them unsuitable for certain applications, as they fail to meet the requirements for colorlessness and stability in high-temperature conditions.
Innovation Solution
The development of rosin esters comprising at least 70% by weight of esterified dehydroabietic acid and dihydroabietic acid, with a weight average molecular weight of at least 800 g/mol, and an oxidative-induction time of at least 75 minutes at 130°C when combined with 1000 ppm or less of an antioxidant, along with improved color stability, achieved through esterification and potential hydrogenation in the presence of activated carbon.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional rosin esters are used, then they provide basic adhesive and modifying properties, but they exhibit poor oxidative stability and are colored
Solution Approach 1:
The patent applies parameter changes by controlling the molecular weight (at least 800 g/mol), hydroxyl number (5.0 or less), and compositional ratios of esterified dehydroabietic and dihydroabietic acids (at least 70% by weight) to simultaneously achieve colorlessness (Gardner color 8.5 or less) and improved oxidative stability (oxidative-induction time of at least 75 minutes at 130°C)
Solution Approach 2:
The patent creates a composite rosin ester material with specific compositional requirements - at least 70% by weight consisting of esterified dehydroabietic acid and esterified dihydroabietic acid in specific ratios, combined with controlled molecular weight and hydroxyl number parameters to achieve both colorlessness and oxidative stability
2Adaptability or versatility
If rosin esters are used as tackifiers in hot-melt adhesives, then they provide tackifying properties, but they exhibit poor color stability at high temperatures
Solution Approach 1:
The patent uses parameter changes by optimizing molecular weight (at least 800 g/mol), hydroxyl number (5.0 or less), and the ratio of esterified dehydroabietic to esterified dihydroabietic acid to achieve both tackifying properties and color stability (less than 10% change in Gardner color when heated to 160°C for three hours)
3Reliability
If existing rosin esters are used, then they provide basic functional properties, but they require more than 1000 ppm antioxidant to achieve acceptable oxidative stability
Solution Approach 1:
The patent applies parameter changes by controlling molecular weight (at least 800 g/mol), hydroxyl number (5.0 or less), and compositional ratios (at least 70% esterified dehydroabietic and dihydroabietic acids) to achieve inherent oxidative stability (oxidative-induction time of at least 75 minutes at 130°C) with minimal antioxidant (1000 ppm or less)
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 resulting rosin esters demonstrate enhanced oxidative stability and colorlessness, with a neat Gardner color of 8.5 or less, and exhibit less than a 10% change in color when heated to 160°C for three hours, effectively addressing the limitations of existing rosin esters.
Implementation Method 1
The esterification reaction can comprise contacting the rosin with the alcohol in the presence of activated carbon
Implementation Method 2
In other embodiments, the rosin ester is a hydrogenated rosin ester (e.g., the rosin ester is subjected to hydrogenation following the esterification reaction)
Data Source
AI summary
Rosin esters are provided. The rosin esters can exhibit improved color (e.g., the rosin ester can have a neat Gardner color of 8.5 or less), improved oxidative stability (e.g., when 1000 ppm or less of an antioxidant is present in combination with the rosin ester, the rosin ester can exhibit an oxidative-induction time at 130°C of at least 75 minutes), improved color stability (e.g., the rosin ester can exhibit less than a 10% change in neat Gardner color when heated to a temperature of 160°C for a period of three hours), or combinations thereof. Also provided polymeric compositions comprising the rosin esters, as well as methods of making the rosin esters.