Tin Neodecanoate Catalyst for Polyurethane Foams

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Solution Overview

Problem

The use of traditional tin catalysts in polyurethane foam production raises toxicological concerns, particularly regarding the release of potentially hazardous substances like 2-ethylhexanoic acid, necessitating the development of safer alternatives that maintain effective catalytic performance with reduced tin content and emissions.

Innovation Solution

The use of a catalyst system containing the tin salt of neodecanoic acid, which allows for the production of polyurethane foams with increased closed-cell content and reduced tin requirements, offering improved catalytic activity and lower emissions compared to traditional systems like tin octoate or tin isononanoate.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional tin catalysts like tin octoate are used in polyurethane foam production, then catalytic activity is maintained, but toxicological concerns arise due to release of hazardous substances like 2-ethylhexanoic acid

Engineering Contradiction:
Improvecatalytic activityVSAvoidtoxicological concerns
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The invention changes the chemical parameter of the carboxylic acid ligand from traditional 2-ethylhexanoic acid to neodecanoic acid. This substitution maintains the catalytic functionality while eliminating the toxicological concerns associated with 2-ethylhexanoic acid emissions, directly resolving the contradiction between maintaining catalytic activity and reducing harmful factors.

Inventive Principle:
Principle #35Parameter changes

2Object-affected harmful factors

If catalyst systems with less toxic ligands are used to reduce emissions, then toxicological safety is improved, but application quantities must be increased due to low tin content and strong shielding of active tin

Engineering Contradiction:
Improveemissions reductionVSAvoidapplication quantity
Core Design Contradiction:
Object-affected harmful factorsVSQuantity of substance

Solution Approach 1:

The invention optimizes the ligand structure by using neodecanoic acid with a specific branching pattern (three methyl groups at positions 3, 5, and 5) that reduces steric shielding of the active tin center. This structural parameter change allows maintaining lower tin content and reduced emissions while avoiding the need to increase application quantities, thus resolving the contradiction between emissions reduction and application quantity.

Inventive Principle:
Principle #35Parameter changes

3Stability of the object's composition

If tin catalysts are used to produce closed-cell foams, then foam density and structural integrity are improved, but emissions of acid components increase

Engineering Contradiction:
Improveclosed-cell contentVSAvoidacid component emissions
Core Design Contradiction:
Stability of the object's compositionVSObject-generated harmful factors

Solution Approach 1:

The invention changes the acid component parameter from traditional carboxylic acids to neodecanoic acid, which has a branched structure with three methyl groups that reduce volatility and emissions. This parameter change enables the production of closed-cell foams with high structural integrity while simultaneously reducing acid component emissions, resolving the contradiction between foam stability and emissions reduction.

Inventive Principle:
Principle #35Parameter changes

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 tin neodecanoate catalyst system enables the production of polyurethane foams with enhanced closed-cell characteristics and reduced tin content, meeting stringent emission and toxicity standards while maintaining catalytic efficiency, particularly in the automotive and furniture industries.

Implementation Method 1

The tin octoate serves as a catalyst for the reaction of isocyanates with polyols (also called a gel catalyst) via a complex transition state

Methodology Applied
Scientific EffectCatalysis: Catalysis

Implementation Method 2

During the production of the foam, the tin octoate hydrolyzes and releases both the salt of 2-ethylhexanoic acid and the acid itself

Methodology Applied
Scientific EffectHydrolysis: Hydrolysis

Data Source

PatentEP2941317B1Use of tin salts of neodecanoic acid in the production of polyurethane foams
Publication Date: 2019.12.25 EVONIK OPERATIONS GMBH
  • EP2941317B1 patent drawingFigure 1
  • EP2941317B1 patent drawing

AI summary

The invention relates to a catalyst system that is suitable for catalyzing the production of polyurethane systems. The catalyst system is characterized by containing a tin salt of neodecanoic acid.