Cationic Electrodeposition Coating Anti-Cissing Film Smoothness

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Solution Overview

Problem

Cationic electrodeposition coating compositions face a trade-off between achieving good anti-cissing properties and maintaining a smooth, even coating film appearance, with existing solutions either compromising on smoothness or unevenness.

Innovation Solution

A cationic electrodeposition coating composition comprising a silicone compound with an SP value between 10.5 and 15.0, specifically polyether, polyester, or polyacrylic modified silicone compounds, in a controlled amount within the coating composition, which enhances both anti-cissing properties and coating film smoothness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a gelled fine particle polymer with intra-particle crosslinking is used to improve anti-cissing property, then anti-cissing property is improved, but coating film smoothness deteriorates

Engineering Contradiction:
Improveanti-cissing propertyVSAvoidcoating film smoothness
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The invention changes the chemical structure parameters of the polymer by introducing silane groups that undergo crosslinking reactions. This transforms the polymer structure to achieve both improved anti-cissing property and maintained coating film smoothness, resolving the contradiction between these two properties.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention creates a composite structure by combining the gelled fine particle polymer with silane crosslinking components. This composite approach allows the material to exhibit both the anti-cissing properties of the gelled structure and the smoothness provided by the crosslinked network, simultaneously achieving both desired properties.

Inventive Principle:
Principle #40Composite materials

2Reliability

If extender pigment is incorporated to improve anti-cissing property, then anti-cissing property is improved, but coating film appearance deteriorates

Engineering Contradiction:
Improveanti-cissing propertyVSAvoidcoating film appearance
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The invention extracts and removes the extender pigment component from the coating formulation, replacing it with the silane-crosslinked polymer system. This elimination of the harmful extender pigment while maintaining anti-cissing functionality through the crosslinked polymer structure resolves the contradiction between anti-cissing property and coating film appearance.

Inventive Principle:
Principle #2Taking out (Extraction)

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 composition achieves a balance between excellent anti-cissing properties and smooth, even coating film appearance, while maintaining stability in aqueous systems and reducing environmental impact by minimizing solvent use.

Implementation Method 1

a silicone compound (A) having an SP value of more than 10.5 and 15.0 or less

Methodology Applied
Scientific EffectSurface tension: Surface Tension

Implementation Method 2

the silicone compound (A) is contained in an amount of 0.01 parts by mass or more and 4.5 parts by mass or less per 100 parts by mass of the resin solid content of the film forming resin (B)

Methodology Applied
Scientific EffectWetting: Wetting

Implementation Method 3

forming an uncured electrodeposition coating film by immersing an article to be coated in the cationic electrodeposition coating composition and performing electrodeposition coating

Methodology Applied
Scientific EffectElectrodeposition: Electrodeposition

Implementation Method 4

heat-curing the uncured electrodeposition coating film to form a cured electrodeposition coating film on the article

Methodology Applied
Scientific EffectHeat curing: Heat Treatment

Data Source

PatentUS11945962B2Cationic electrodeposition coating composition and method for forming cured electrodeposition coating film
Publication Date: 2024.04.02 NIPPON PAINT AUTOMOTIVE COATINGS

AI summary

The present invention provides a cationic electrodeposition coating composition that has both good anti-cissing property and good coating film appearance. This is a cationic electrodeposition coating composition containing a silicone compound (A) having an SP value of more than 10.5 and 15.0 or less, and a film forming resin (B), wherein the silicone compound (A) is contained in an amount of 0.01 parts by mass or more and 4.5 parts by mass or less per 100 parts by mass of the resin solid content of the film forming resin (B). For example, the silicone compound (A) is at least one species selected from the group consisting of a polyether modified silicone compound (A-1), a polyester modified silicone compound (A-2), and a polyacrylic modified silicone compound (A-3).