Sliding Member Coating Composition for Adhesion and Lubricity

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Sliding members with coating films face a trade-off between lubricity and adhesion, where increasing lubricity often leads to reduced adhesion, causing the coating film to peel off, especially under high load conditions, and existing solutions struggle to maintain both properties effectively over time.

Innovation Solution

A sliding member composition featuring a first coating film layer with a binder resin and resin beads, and a second coating film layer with a binder resin and solid lubricant, where the resin beads have a lower adhesion strength with the binder resin than with the substrate, preventing peeling by breaking inside the coating film and maintaining lubricity through the use of polytetrafluoroethylene and graphite as solid lubricants.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the ratio of solid lubricant in the coating film is increased to enhance lubricity, then the lubricity of the coating film is improved, but the adhesion between the coating film and the base reduces

Engineering Contradiction:
ImprovelubricityVSAvoidadhesion
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent applies local quality by creating a coating film with non-uniform solid lubricant concentration. The solid lubricant concentration is higher at the sliding surface (outer layer) to provide lubricity, and lower at the interface with the base (inner layer) to maintain adhesion. This gradient structure allows different regions of the coating film to have optimized properties for their specific functions.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent uses composite materials by combining binder resin with solid lubricants (such as PTFE, graphite, or molybdenum disulfide) to create a coating film that exhibits both adhesive and lubricating properties. The composite structure allows the binder resin to provide adhesion to the base while the solid lubricant particles provide lubricity at the sliding surface.

Inventive Principle:
Principle #40Composite materials

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 effectively prevents coating film peeling and maintains lubricating function over a long term by ensuring the coating film breaks within the resin beads rather than at the substrate interface, enhancing both adhesion and lubricity.

Implementation Method 1

a solid lubricant including at least one selected from the group consisting of polytetrafluoroethylene, graphite and molybdenum disulfide

Methodology Applied
Scientific EffectBoundary lubrication: Lubrication

Data Source

PatentEP3910047B1Sliding member
Publication Date: 2024.06.26 NOK KLUEBER CO LTD
  • EP3910047B1 patent drawingFigure 1~2
  • EP3910047B1 patent drawingFigure 3

AI summary

To provide a composition for a sliding member and a sliding member which can prevent a coating film from peeling off around an interface of the coating film and an object to be coated and which can maintain lubricating function over a long term. The composition for a sliding member contains a binder resin, a solid lubricant, and at least one type of resin beads selected from the group consisting of amino resin beads and urethane resin beads.