Phosphate-Free Surface Treatment Film for Coating Adhesion

Solution Overview

Problem

Existing chemical conversion treatments using zinc phosphate for metal substrates face challenges with high reactivity leading to difficult wastewater treatment, significant environmental load, and insufficient corrosion resistance and adhesion to coating films.

Innovation Solution

A surface treatment agent comprising zirconium, titanium, or hafnium, alkyldiallylamine polymer, and optionally fluorine, with specific concentration ranges, forms a surface treatment film that enhances corrosion resistance and adhesion to coating films, using a pH-controlled process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If zinc phosphate chemical conversion treatment is used, then corrosion resistance and coating adhesion are improved, but wastewater treatment becomes difficult and environmental load increases

Engineering Contradiction:

Improvecorrosion resistanceVSAvoidenvironmental load

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the chemical composition parameters by replacing zinc phosphate with a specific combination of zirconium/titanium/hafnium compounds and alkyldiallylamine polymer, fundamentally altering the treatment chemistry to eliminate harmful phosphates while maintaining functional performance

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent employs a composite treatment system combining inorganic metal compounds (zirconium/titanium/hafnium) with organic polymer compounds (alkyldiallylamine polymer), creating a synergistic effect that achieves both corrosion resistance and environmental compatibility

Inventive Principle:

Principle #40Composite materials

2Reliability

If zinc phosphate chemical conversion treatment is used, then corrosion resistance is improved, but sludge is generated and wastewater treatment becomes difficult

Engineering Contradiction:

Improvecorrosion resistanceVSAvoidsludge generation

Core Design Contradiction:

ReliabilityVSLoss of substance

Solution Approach 1:

The patent changes the chemical composition parameters by replacing zinc phosphate with a specific combination of zirconium/titanium/hafnium compounds and alkyldiallylamine polymer, fundamentally altering the treatment chemistry to eliminate harmful phosphates while maintaining functional performance

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent converts the previously harmful phosphorous-containing treatment into a beneficial phosphate-free treatment that achieves equivalent or superior performance without generating sludge, turning an environmental liability into a sustainability advantage

Inventive Principle:

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

3Strength

If conventional chemical conversion treatment is used, then coating adhesion is improved, but adhesion to coating film is insufficient

Engineering Contradiction:

Improvecoating adhesionVSAvoidadhesion to coating film

Core Design Contradiction:

StrengthVSReliability

Solution Approach 1:

The patent employs a composite treatment system combining inorganic metal compounds (zirconium/titanium/hafnium) with organic polymer compounds (alkyldiallylamine polymer), creating a synergistic effect that achieves both corrosion resistance and environmental compatibility

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The patent modifies the surface treatment composition by incorporating alkyldiallylamine polymer with specific molecular weight and structure, changing the chemical parameters to enhance interfacial adhesion between the surface treatment film and subsequent coating films

Inventive Principle:

Principle #35Parameter changes

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 surface treatment agent improves adhesion to coating films and corrosion resistance, reducing environmental impact by minimizing sludge generation and enhancing the durability of metal substrates.

Implementation Method 1

surface treatment (chemical conversion treatment) using zinc phosphate

Methodology Applied

Scientific EffectChemical conversion treatment: Chemical Bonding

Implementation Method 2

an alkyldiallylamine polymer (C) includes at least one of a segment having a heterocyclic structure represented by the following formula (1a) or a segment having a heterocyclic structure represented by the following formula (1b)

Methodology Applied

Scientific EffectChemical bonding: Chemical Bonding

Data Source

PatentUS20260055530A1Surface treatment agent, surface-treated metal, and surface treatment method

Publication Date: 2026.02.26 NIPPON PAINT SURF CHEM CO LTD

AI summary

The surface treatment agent is designed to improve adhesion to a coating film. This agent contains at least one metal component (A) selected from the group consisting of zirconium, titanium, and hafnium, as well as an alkyldiallylamine polymer (C). The metal component (A) has a content ranging from 10 ppm to 10,000 ppm by mass, in terms of metal element, relative to the total mass of the surface treatment agent. Furthermore, the alkyldiallylamine polymer (C) includes a segment with a heterocyclic structure represented by formula (1a) or (1b).