Aqueous Acrylic-Urethane Composite Coating for Low-Temperature Curing
Solution Overview
Problem
Existing aqueous coating compositions exhibit insufficient abrasion resistance, chipping resistance, and glass adhesiveness when cured at low temperatures, which is a challenge in energy-efficient coating processes for automobiles.
Innovation Solution
An aqueous dispersion of acrylic urethane composite resin particles comprising a urethane resin portion and an acrylic resin portion, where the urethane resin is synthesized from a compound with a secondary amino group and alkoxysilyl group, and the acrylic resin portion contains a polymerizable unsaturated group without hydroxyl groups, is used to form a coating film with enhanced properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the heating temperature is lowered to reduce energy consumption, then energy efficiency is improved, but chipping resistance and glass adhesiveness become insufficient
Solution Approach 1:
The invention changes the chemical composition parameters of the coating material by incorporating specific compounds: (a1) containing both primary amino group and alkoxysilyl group, (a2) isocyanate group-containing urethane prepolymer, and (b) polymerizable unsaturated group-containing compound with limited hydroxyl groups. This compositional parameter change enables the coating to achieve high chipping resistance and glass adhesiveness at lower curing temperatures without requiring high heating energy
Solution Approach 2:
The invention creates a composite coating system combining multiple functional components: amino-silane compounds for adhesion, isocyanate-urethane prepolymers for crosslinking and mechanical strength, and unsaturated group-containing compounds for polymerization. This composite material approach synergistically achieves both low-temperature curability and high chipping resistance
2Use of energy by moving object
If the heating temperature is lowered to reduce energy consumption, then energy efficiency is improved, but glass adhesiveness becomes insufficient
Solution Approach 1:
The invention changes the chemical composition parameters by incorporating compound (a1) containing both primary amino group and alkoxysilyl group, which provides excellent glass adhesion through chemical bonding. The alkoxysilyl group forms strong covalent bonds with glass surfaces, while the amino group participates in crosslinking reactions, enabling high glass adhesiveness at low curing temperatures without requiring high energy input
Solution Approach 2:
The composite coating system combines amino-silane compounds specifically for glass adhesion, isocyanate-urethane prepolymers for crosslinking, and unsaturated group-containing compounds for polymerization. This multi-component composite approach ensures both low-temperature curability and high glass adhesiveness through synergistic chemical interactions
3Strength
If a coating composition with high reactivity is used to achieve high coating film performance at low temperature, then abrasion resistance is improved, but storage stability becomes insufficient
Solution Approach 1:
The invention applies preliminary action by using compound (a1) containing both primary amino group and alkoxysilyl group, which prepares the coating system for low-temperature crosslinking and adhesion formation in advance. The pre-configured functional groups enable the coating to react efficiently at low temperatures without requiring high reactivity that would compromise storage stability
Solution Approach 2:
The invention optimizes the chemical composition parameters by carefully selecting compounds with appropriate reactivity: (a1) amino-silane for adhesion, (a2) isocyanate-urethane prepolymer for controlled crosslinking, and (b) unsaturated group-containing compound for polymerization. This balanced compositional design achieves high abrasion resistance at low temperature while maintaining adequate storage stability
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 excellent storage stability, abrasion resistance, chipping resistance, and glass adhesiveness even at low curing temperatures, improving the performance of coating films in energy-efficient coating processes.
Implementation Method 1
a urethane resin portion (A) produced from constituent components including a compound (a1) having a secondary amino group and an alkoxysilyl group and an isocyanate group-containing urethane prepolymer (a2)
Implementation Method 2
an acrylic resin portion (B) produced from constituent components including a compound (b) having a polymerizable unsaturated group
Implementation Method 3
a compound (a1) having a secondary amino group and an alkoxysilyl group
Implementation Method 4
an alkoxysilyl group
Data Source
AI summary
The present invention is directed to providing an aqueous dispersion of acrylic urethane composite resin (AB) particles that, when used as a constituent component of an aqueous coating composition, provides the aqueous coating composition with excellent storage stability, the aqueous coating composition being capable of forming a coating film with excellent abrasion resistance, chipping resistance, and glass adhesiveness even when the aqueous coating composition is cured at a relatively low temperature. The aqueous dispersion of acrylic urethane composite resin (AB) particles including a urethane resin portion (A) produced from constituent components including a compound (a1) having a secondary amino group and an alkoxysilyl group and an isocyanate group-containing urethane prepolymer (a2), and an acrylic resin portion (B) produced from constituent components including a compound (b) having a polymerizable unsaturated group and having no hydroxyl group or one hydroxyl group.