Synergistic Catalyst for Radiation Curable Coatings

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current radiation curable coatings are inflexible, prone to high shrinkage, and inadequate in terms of adhesion and formability, particularly in rigid and flexible packaging applications, due to low reactivity of aliphatic epoxide groups and thermal polymerization issues with strong acid catalysts.

Innovation Solution

The use of a synergistic catalyst combination involving a phosphoric acid compound and a triflic acid catalyst to enhance the reaction rate and conversion of epoxidized vegetable oils with hydroxyl functional (meth)acrylates, forming (meth)acrylate functional polyether polyols, which improves adhesion and flexibility in radiation curable coating compositions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If strong acid catalysts are used to catalyze the reaction of epoxidized vegetable oils with hydroxyl functional compounds, then the reaction rate increases, but thermal polymerization occurs at high temperature

Engineering Contradiction:
Improvereaction rateVSAvoidthermal polymerization
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The patent changes the chemical parameters of the catalyst system by introducing a synergistic combination of phosphoric acid compound and triflic acid catalyst. This combination allows the reaction to proceed at high conversion (99.9% epoxide conversion) while using reduced acid catalyst concentrations, thereby suppressing thermal polymerization that occurs with strong acid catalysts alone at high temperatures.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The phosphoric acid compound acts as an intermediary that enhances the effectiveness of the triflic acid catalyst. The epoxy phosphate intermediate formed during the reaction helps adhere the cured coating to the substrate and significantly enhances the catalyst's effectiveness, allowing lower catalyst concentrations to achieve high reaction rates without causing harmful thermal polymerization.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Manufacturing precision

If high conversion of epoxide groups is achieved, then coating performance improves, but acid catalyst concentration must be increased which causes thermal polymerization

Engineering Contradiction:
Improveepoxide group conversionVSAvoidthermal polymerization
Core Design Contradiction:
Manufacturing precisionVSObject-generated harmful factors

Solution Approach 1:

The patent achieves high epoxide group conversion (99.9%) by changing the catalyst system parameters to a synergistic combination of phosphoric acid compound and triflic acid catalyst. This allows complete conversion without increasing acid catalyst concentration, thereby avoiding thermal polymerization that would otherwise occur.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The phosphoric acid compound and its reaction product (epoxy phosphate) serve as intermediaries that enable high conversion rates without requiring high acid catalyst concentrations. The epoxy phosphate specifically helps adhere the cured coating to the substrate while the phosphoric acid compound enhances catalyst effectiveness, allowing 99.9% conversion without thermal polymerization.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Stability of the object's composition

If aliphatic epoxide groups are used in radiation curable coatings, then flexibility is improved, but reactivity is reduced making high conversion difficult

Engineering Contradiction:
ImproveflexibilityVSAvoidreaction rate
Core Design Contradiction:
Stability of the object's compositionVSProductivity

Solution Approach 1:

The patent changes the catalytic parameters by introducing a synergistic catalyst combination that specifically enhances the reactivity of aliphatic epoxide groups. The phosphoric acid compound and triflic acid catalyst together enable high reaction rates and complete conversion (99.9%) of the less reactive aliphatic epoxide groups, maintaining flexibility while achieving high conversion.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The phosphoric acid compound acts as an intermediary that specifically activates the reaction between aliphatic epoxide groups and hydroxyl functional compounds. The epoxy phosphate intermediate formed enhances both the reaction rate and the final coating's adhesion to substrate, enabling high conversion of flexible aliphatic epoxide groups.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Reliability

If acid catalyst concentration is reduced to prevent thermal polymerization, then thermal stability improves, but reaction rate and conversion decrease

Engineering Contradiction:
Improvethermal stabilityVSAvoidreaction rate
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent changes the catalyst system parameters from a single strong acid catalyst to a synergistic combination of phosphoric acid compound and triflic acid catalyst. This combination achieves high reaction rates and complete conversion (99.9% epoxide conversion) while using reduced acid catalyst concentrations, thereby maintaining thermal stability and preventing thermal polymerization.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The phosphoric acid compound serves as an intermediary that amplifies the catalytic activity of the triflic acid catalyst. The epoxy phosphate intermediate formed during the reaction significantly enhances catalyst effectiveness, allowing the system to achieve high reaction rates at lower catalyst concentrations, thus maintaining thermal stability while preserving productivity.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 approach increases epoxide group conversion from 90% to 99.9% at reduced acid catalyst concentrations, enhancing adhesion and flexibility, and reducing thermal polymerization risks, thereby improving the performance of radiation curable coatings for packaging applications.

Implementation Method 1

reacting an epoxidized vegetable oil with a phosphoric acid compound to form an epoxy phosphate, and then reacting the epoxy phosphate with a hydroxyl functional (meth)acrylate in the presence of an acid catalyst to form the (meth)acrylate functional polyether polyol

Methodology Applied
Scientific EffectCatalysis: Catalysis

Implementation Method 2

The phosphate functionality of the epoxy phosphate helps adhere the radiation cured coating composition to the substrate

Methodology Applied
Scientific EffectAdhesion: Adhesive

Implementation Method 3

Many currently available radiation curable coatings, such as those cured with ultra-violet ('UV') radiation or electron beam ('EB') radiation

Methodology Applied
Scientific EffectPhotopolymerization: Photopolymerisation

Data Source

PatentEP2970707B1Synergistic catalyst combination for the preparation of radiation curable oligomers
Publication Date: 2017.05.03 AKZO NOBEL COATINGS INT BV

AI summary

Radiation curable coating compositions are disclosed. In some embodiments, the coating compositions are used to coat substrates such as packaging materials and the like for the storage of food and beverages. The coating compositions may have a (meth)acrylate functional polyether polyol prepared by reacting an epoxidized vegetable oil in the presence of a phosphoric acid compound to form an epoxy phosphate, and reacting the epoxy phosphate with a hydroxyl functional (meth)acrylatein the presence of an acid catalyst to form the(meth)acrylate functional polyether polyol.