Aqueous Polyurethane Primer Dispersion for Amorphous Resin Adhesion

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing primer layers formed using polyurethane resin dispersions do not adequately satisfy adhesion to amorphous resin substrates and lack sufficient warm water resistance, chemical resistance, and resistance to heat and humidity, with issues such as moisture penetration and solvent-induced collapse.

Innovation Solution

A primer-forming aqueous polyurethane dispersion containing specific components like an aromatic isocyanate, alkylene oxide adduct of bisphenol A, linear aliphatic polyol, diol compound with a carboxyl group, and polyol compound X, which form a polymer that enhances adhesion and resistance to warm water, chemicals, and heat.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If existing polyurethane resin dispersions are used to form primer layers, then the primer layers can be formed with basic coating properties, but the adhesion to amorphous resin substrates and resistance to warm water, chemicals, and heat are insufficient

Engineering Contradiction:

Improveadhesion to amorphous resin substrate and resistance to warm water, chemicals, and heatVSAvoidcomplexity of polyol compound composition

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent uses a composite polyol system combining five specific components: aromatic isocyanate, alkylene oxide adduct of bisphenol A, linear aliphatic polyol (3-5 carbon atoms), diol compound with carboxyl group, and polyol compound X (MW 500-3000). This composite approach creates synergistic effects where each component contributes specific properties: the aromatic isocyanate provides adhesion to amorphous resins, the alkylene oxide adduct provides flexibility and water resistance, the linear aliphatic polyol provides chemical resistance, the carboxyl-containing diol enhances bonding, and polyol X provides heat and humidity resistance. Together they form a primer layer with comprehensive performance.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The patent specifies precise parameter ranges for each component to optimize performance: polyol compound X with number-average molecular weight of 500-3000, linear aliphatic polyol with 3-5 carbon atoms, and specific molar ratios between components. These parameter controls ensure the primer layer achieves the desired balance of adhesion, water resistance, chemical resistance, and heat resistance without excessive complexity.

Inventive Principle:

Principle #35Parameter changes

2Ease of operation

If organic solvent-containing coating compositions are applied onto primer layers, then the coating can be applied effectively, but the organic solvent causes collapse of the primer layer

Engineering Contradiction:

Improvecoating applicabilityVSAvoidstructural integrity of primer layer

Core Design Contradiction:

Ease of operationVSStrength

Solution Approach 1:

The patent converts the potential harm of organic solvents into a benefit by designing a primer layer with exceptional solvent resistance. The specific polyol composition creates a crosslinked network structure that is insoluble and resistant to organic solvents, allowing subsequent coating applications without primer layer collapse. The carboxyl-containing diol and aromatic isocyanate form dense crosslinks that prevent solvent penetration and structural damage.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent performs preliminary action by forming a pre-treated primer layer with specific adhesive and solvent-resistant properties before applying the final coating. This primer layer acts as a stable foundation that has already been optimized for both adhesion to the substrate and resistance to subsequent organic solvent exposure, preventing collapse issues during later coating steps.

Inventive Principle:

Principle #10Preliminary action

3Strength

If primer layers are formed to improve adhesion and surface properties, then scratch resistance and mechanical strength are improved, but the primer layers lack sufficient resistance to moisture penetration and degradation under high humidity

Engineering Contradiction:

Improvescratch resistance and mechanical strengthVSAvoidresistance to moisture penetration and high humidity degradation

Core Design Contradiction:

StrengthVSReliability

Solution Approach 1:

The patent employs a composite polyol system where specific components address different degradation mechanisms: the alkylene oxide adduct of bisphenol A provides hydrophobicity and water resistance, the aromatic isocyanate creates dense crosslinking that blocks moisture penetration, and the polycarbonate polyol component provides dimensional stability under humidity. This composite structure maintains mechanical strength and scratch resistance while adding superior moisture and humidity resistance.

Inventive Principle:

Principle #40Composite materials

Data Source

PatentEP4685201A1Aqueous polyurethane dispersion for primer, primer layer, and layered product

Publication Date: 2026.01.28 DKS CO LTD

AI summary

Provided are a primer-forming aqueous polyurethane dispersion that can form a primer layer excellent in adhesion, warm water resistance, chemical resistance, and resistance to heat and humidity, a primer layer, and a laminate. The present invention is a primer-forming aqueous polyurethane dispersion used for forming a primer layer on an amorphous resin substrate, the primer-forming aqueous polyurethane dispersion containing a polymer of a composition including an aromatic isocyanate, an alkylene oxide adduct of bisphenol A, a linear aliphatic polyol having 3 to 5 carbon atoms, a diol compound having a carboxyl group, and a polyol compound X having a number-average molecular weight of 500 to 3000.