Tin-Free Silane-Functional Polyurethane Coating for Room-Temperature Curing

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing polyurethane-based coatings require high temperatures for rapid curing and often contain toxicologically questionable tin compounds, limiting their application and safety.

Innovation Solution

A composition comprising an adduct of isocyanatosilanes to hydroxy-functional compounds, a tin-free catalyst, and an aminosilane, which can cure at temperatures between 0°C to 40°C, forming stable coatings without the use of tin.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If tin-containing catalysts are used to ensure rapid crosslinking at room temperature, then crosslinking rate is improved, but toxicological safety deteriorates

Engineering Contradiction:

Improvecrosslinking rateVSAvoidtoxicological safety

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent extracts and removes the harmful tin-containing catalyst from the system while maintaining the desired rapid crosslinking function through alternative catalytic components and formulation adjustments

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent employs alternative catalyst systems that are less toxic and can be used in controlled amounts, replacing the persistent toxicological burden of tin compounds

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

2Productivity

If high temperatures are used for rapid curing, then crosslinking rate is improved, but energy consumption and processing complexity worsen

Engineering Contradiction:

Improvecuring speedVSAvoidenergy consumption

Core Design Contradiction:

ProductivityVSUse of energy by stationary object

Solution Approach 1:

The patent changes the chemical parameters of the formulation (adding specific catalysts and co-catalysts) to enable rapid curing at lower temperatures, thereby reducing energy consumption while maintaining high productivity

Inventive Principle:

Principle #35Parameter changes

3Productivity

If tin-containing catalysts are used to achieve sufficient crosslinking rate, then crosslinking performance is improved, but environmental compliance and application scope worsen

Engineering Contradiction:

Improvecrosslinking rateVSAvoidapplication scope

Core Design Contradiction:

ProductivityVSAdaptability or versatility

Solution Approach 1:

The patent removes tin-containing catalysts from the formulation to enable application on sensitive substrates and in environments where toxicological concerns would limit use, while maintaining adequate crosslinking performance through alternative catalytic systems

Inventive Principle:

Principle #2Taking out (Extraction)

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 composition allows for rapid curing at room temperature, reducing VOC content, improving toxicological profiles, and providing stable, chemical-resistant coatings with high mechanical strength and weather resistance.

Implementation Method 1

B) a tin-free catalyst and C) an aminosilane

Methodology Applied

Scientific EffectCatalysis: Catalysis

Data Source

PatentEP3620480B1Tin-free catalysis of silane-functional polyurethane crosslinking

Publication Date: 2026.02.25 EVONIK OPERATIONS GMBH

AI summary

The present invention relates to a composition comprising at least A) an adduct of isocyanatosilanes to hydroxy-functional compounds, B) a tin-free catalyst, C) an aminosilane and a coating agent comprising at least the composition, and the use of the coating agent.