Glycol Compositions with Tocopherol Blends for Antioxidant Stability

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Solution Overview

Problem

Glycol compositions containing tocopherols as antioxidants can experience a reduction in total tocopherol content when exposed to 316 stainless steel under decreasing temperature conditions, leading to increased formaldehyde levels and potential failure in certifications.

Innovation Solution

A glycol composition utilizing a tocopherol blend where D-alpha tocopherol is less than 50 wt % of the combined tocopherols, which reduces antioxidant fade and maintains higher tocopherol levels even under temperature changes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a tocopherol blend with high D-alpha tocopherol content (≥50 wt%) is used in glycol composition, then initial antioxidant effectiveness is improved, but tocopherol depletion under decreasing temperature conditions increases leading to higher formaldehyde levels

Engineering Contradiction:
Improveantioxidant effectivenessVSAvoidtocopherol depletion
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The patent changes the compositional parameters of the tocopherol blend by reducing D-alpha tocopherol content to less than 50 wt% and increasing other tocopherol isomers (D-beta, D-gamma, D-delta). This parameter change resolves the contradiction by providing a blend that maintains antioxidant effectiveness while exhibiting reduced depletion under decreasing temperature conditions, thereby preventing formaldehyde formation.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses a composite tocopherol blend comprising multiple tocopherol isomers (D-alpha, D-beta, D-gamma, and/or D-delta tocopherols) in specific proportions. This composite approach leverages the synergistic effects of different isomers to achieve both initial antioxidant effectiveness and stability during temperature fluctuations, resolving the contradiction between effectiveness and depletion resistance.

Inventive Principle:
Principle #40Composite materials

2Object-generated harmful factors

If tocopherols are used as antioxidants in glycol to prevent degradation, then formaldehyde formation is reduced, but tocopherol content decreases under decreasing temperature conditions leading to certification failure

Engineering Contradiction:
Improveformaldehyde formationVSAvoidtocopherol content stability
Core Design Contradiction:
Object-generated harmful factorsVSStability of the object's composition

Solution Approach 1:

The patent modifies the tocopherol composition parameters by adjusting the ratios of different tocopherol isomers, specifically limiting D-alpha tocopherol to less than 50 wt%. This parameter optimization ensures that the blend maintains stable total tocopherol content during temperature cycles while continuing to effectively prevent formaldehyde formation throughout the glycol storage life.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies preliminary action by selecting a tocopherol blend composition before exposure to temperature conditions that is specifically designed to resist depletion. The pre-optimized blend composition (with D-alpha tocopherol <50 wt%) anticipates and prevents the depletion problem that would occur with traditional high D-alpha formulations, ensuring certification compliance is maintained throughout storage.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If D-alpha tocopherol is the primary component (≥50 wt%) of the tocopherol blend, then antioxidant activity is enhanced, but antioxidant fade increases under temperature stress

Engineering Contradiction:
Improveantioxidant activityVSAvoidantioxidant fade resistance
Core Design Contradiction:
ReliabilityVSDuration of action of moving object

Solution Approach 1:

The patent optimizes the compositional parameters of the tocopherol blend by reducing D-alpha tocopherol content below 50 wt% and balancing other isomers. This parameter adjustment resolves the contradiction by maintaining sufficient antioxidant activity while dramatically improving resistance to antioxidant fade under temperature stress, thereby extending the duration of protective action.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs a composite tocopherol blend with multiple isomers (D-alpha, D-beta, D-gamma, and/or D-delta) in optimized proportions. This composite structure provides both immediate antioxidant activity and long-term fade resistance, as the different isomers complement each other's strengths and weaknesses under varying temperature conditions.

Inventive Principle:
Principle #40Composite materials

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 use of a tocopherol blend with less than 50 wt % D-alpha tocopherol in glycol compositions effectively minimizes tocopherol depletion, thereby reducing formaldehyde formation and maintaining compliance with certification standards.

Implementation Method 1

Tocopherols exhibit an antioxidative activity via hydrogen donation to a free radical and subsequent formation of a complex between the radical and the tocopherol radical.

Methodology Applied
Scientific EffectHydrogen donation: Redox Reactions

Implementation Method 2

Tocopherols exhibit an antioxidative activity via hydrogen donation to a free radical

Methodology Applied
Scientific EffectAntioxidative activity: Oxidation

Data Source

PatentUS20250090668A1Glycol compositions including tocopherols
Publication Date: 2025.03.20 DOW GLOBAL TECHNOLOGIES LLC

AI summary

A glycol composition comprises a glycol and a tocopherol blend comprising D-alpha tocopherol and one or more of D-beta tocopherol, D-gamma tocopherol and D-delta tocopherol, wherein the D-alpha tocopherol is less than 50 wt % of the combined D-alpha tocopherol, D-beta tocopherol, D-gamma tocopherol and D-delta tocopherol.