Cyclic Anhydride Crosslinkers for Formaldehyde-Free Packaging Coatings
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Solution Overview
Problem
Existing coatings often contain formaldehyde, which industries seek to reduce or eliminate due to health and environmental concerns, and there is a need for formaldehyde-free thermoset coatings that provide protective and decorative qualities.
Innovation Solution
A coating composition comprising a film-forming resin with active hydrogen atoms and a crosslinking material formed from a reaction mixture with ≥70% cyclic unsaturated acid anhydride and/or its diacid derivative, which reacts with alcohol, amine, thiol, or water to create a crosslinking material with an acid number of at least 100 mg KOH/g, eliminating the need for formaldehyde-based crosslinkers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If formaldehyde-based crosslinkers are used, then crosslinking effectiveness is achieved, but harmful formaldehyde is released causing health and environmental issues
Solution Approach 1:
The invention changes the chemical parameters of the crosslinking system by replacing formaldehyde-based crosslinkers with cyclic unsaturated acid anhydrides (≥70% by weight) that undergo polycondensation reactions. This parameter change eliminates formaldehyde release while maintaining crosslinking effectiveness through alternative reaction mechanisms involving alcohol, amine, thiol, or water functional groups.
Solution Approach 2:
The invention converts the harmful formaldehyde byproduct into a beneficial formaldehyde-free system by using cyclic unsaturated acid anhydrides as crosslinking materials. The polycondensation reaction of these anhydrides with functional groups (alcohol, amine, thiol, or water) produces crosslinked networks without generating harmful formaldehyde, thus transforming a harmful process into a benign one.
2Duration of action of stationary object
If conventional crosslinking materials are used, then coating durability is improved, but the coating contains harmful formaldehyde
Solution Approach 1:
The invention changes the chemical composition parameters of the crosslinking material from formaldehyde-based compounds to cyclic unsaturated acid anhydrides with ≥70% content. This parameter change enables the coating to achieve durable crosslinked networks through polycondensation reactions while eliminating formaldehyde content, thus improving both durability and safety.
Solution Approach 2:
The invention uses composite crosslinking materials formed by the reaction product of cyclic unsaturated acid anhydride with functional groups (alcohol, amine, thiol, or water). This composite approach creates crosslinked networks that provide long-term durability while being free of harmful formaldehyde, combining the benefits of durability with environmental safety.
3Object-generated harmful factors
If formaldehyde-free crosslinking materials are used, then health and environmental safety is improved, but crosslinking performance may be compromised
Solution Approach 1:
The invention changes the chemical parameters by using cyclic unsaturated acid anhydrides (≥70% by weight) with controlled molecular weight and functionality. These parameter changes enable the crosslinking material to achieve sufficient crosslinking density and network formation without formaldehyde, thereby maintaining crosslinking performance while ensuring formaldehyde-free composition.
Solution Approach 2:
The invention applies local quality by ensuring that the cyclic unsaturated acid anhydride component has specific functional group distributions and reactivity characteristics. This local quality control at the molecular level ensures that the crosslinking performance is maintained in the formaldehyde-free system through optimized reaction kinetics and crosslinking density.
4Reliability
If high acid number crosslinking material (≥100 mg KOH/g) is used, then acid resistance is improved, but formulation complexity increases
Solution Approach 1:
The invention changes the acid number parameter of the crosslinking material to ≥100 mg KOH/g by using cyclic unsaturated acid anhydrides with appropriate functionality. This parameter change provides the necessary acid resistance for packaging applications while the systematic approach to formulation (using ≥70% cyclic unsaturated acid anhydride with standard functional groups) keeps the complexity manageable through standardized reaction patterns.
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 solution provides a formaldehyde-free coating with effective crosslinking properties, ensuring suitable acid resistance and flexibility for packaging applications while maintaining decorative qualities.
Implementation Method 1
a crosslinking material comprising the reaction product of a reaction mixture comprising: (i) ≥70% by weight of a cyclic unsaturated acid anhydride and/or diacid derivative thereof by total solid weight of the monomers from which the crosslinking material is formed; (ii) optionally, an ethylenically unsaturated monomer; and (iii) optionally, an alcohol, amine, thiol and/or water, wherein at least a portion of the cyclic unsaturated acid anhydride and/or diacid derivative thereof is reacted with the alcohol, amine, thiol and/or water
Implementation Method 2
a crosslinking material operable to crosslink the functional group having an active hydrogen atom on the film-forming resin
Data Source
AI summary
A crosslinking material, the crosslinking material comprising the reaction product of a reaction mixture comprising: (ii) ≥70% by weight of a cyclic unsaturated acid anhydride and/or diacid derivative thereof by total solid weight of the monomers from which the crosslinking material is formed; (ii) optionally, an ethylenically unsaturated monomer; and (iii) optionally, an alcohol, amine, thiol and/or water, wherein at least a portion of the cyclic unsaturated acid anhydride and/or diacid derivative thereof is reacted with the alcohol, amine, thiol and/or water, when present; and wherein the crosslinking material has an acid number of at least 100 mg KOH/g.