Acid-Modified Polyester Undercoat Paint for Trivalent Chromium Adhesion

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Trivalent chromium-plated surfaces exhibit poor adhesiveness and physical properties such as water resistance, weather resistance, and chipping resistance when coated with typical undercoat paint compositions designed for hexavalent chromium-plated surfaces.

Innovation Solution

An undercoat paint composition comprising an acid-modified polyester-based resin, a pigment, and a solvent is used, where the acid-modified polyester-based resin increases the specific surface area of the trivalent chromium-plated surface, enhancing adhesiveness and the physical properties of the coating film.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a typical undercoat paint composition for hexavalent chromium-plated surfaces is applied to trivalent chromium-plated surfaces, then the coating process is simple and familiar, but the adhesiveness and physical properties of the coating film are poor

Engineering Contradiction:
Improvecoating process simplicityVSAvoidadhesiveness and physical properties
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent modifies the chemical composition parameters of the undercoat paint by incorporating specific resin systems (polyester resin with carboxyl group, polyisocyanate compound) and additives (phosphoric acid, silane coupling agent) to optimize performance on trivalent chromium surfaces. This changes the paint formulation parameters to achieve both good adhesiveness and ease of application

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses a composite resin system combining polyester resin, polyisocyanate compound, and auxiliary agents (phosphoric acid, silane coupling agent) to create a multi-functional undercoat paint that simultaneously provides adhesion, corrosion resistance, and surface compatibility with trivalent chromium plating

Inventive Principle:
Principle #40Composite materials

2Reliability

If the specific surface area of the plated surface is increased through acid-modified polyester-based resin, then the adhesiveness and physical properties of the coating film are enhanced, but the complexity of the paint composition increases

Engineering Contradiction:
Improveadhesiveness and physical propertiesVSAvoidpaint composition complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines multiple functional components into a unified paint composition: the acid-modified polyester-based resin serves both as the main binder and as the agent that increases surface area through controlled corrosion; phosphoric acid and silane coupling agent are integrated to provide both adhesion promotion and corrosion resistance in a single formulation

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The acid-modified polyester-based resin performs multiple functions simultaneously: it acts as the primary binder, modifies the surface to increase specific surface area, provides corrosion resistance, and enhances adhesiveness. This multi-functionality reduces the need for separate additives and simplifies the overall composition

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 undercoat paint composition forms a coating film with excellent adhesiveness, water resistance, weather resistance, compatibility with high-pressure car washing, and chipping resistance when applied to trivalent chromium-plated surfaces, effectively addressing the limitations of existing compositions.

Implementation Method 1

an acid-modified polyester-based resin in the undercoat paint composition corrodes the plated surface, thereby increasing the specific surface area of the plated surface

Methodology Applied
Scientific EffectCorrosion: Crevice Corrosion

Implementation Method 2

due to the increase in the specific surface area, the adhesiveness between a manufactured coating film and the plated surface is increased

Methodology Applied
Scientific EffectAdhesion: Adhesive

Data Source

PatentUS12297370B2Undercoat paint composition
Publication Date: 2025.05.13 KCC CORP

AI summary

The present invention relates to an undercoat paint composition comprising an acid-modified polyester resin, a pigment, and a solvent.