Copper-Free Brake Pad Friction Material for Stop Noise Suppression

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Solution Overview

Problem

Conventional non-asbestos-organic (NAO) friction materials for disc brake pads face challenges in reducing copper content to prevent environmental contamination while also addressing just-before-stopping noise issues, which are not adequately resolved by existing solutions that either omit copper or restrict flexibility in composition.

Innovation Solution

Incorporating specific amounts and sizes of fluoropolymer particles and zirconium oxide into the friction material composition to prevent abrasive powder aggregation and subsequent noise generation, without using copper, by adding 0.5-5 weight % of fluoropolymer particles with 10-1000 μm diameter and 15-35 weight % of zirconium oxide with 1-8 μm diameter, which disperses fine powder uniformly and inhibits water absorption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If copper component is added to NAO friction material to meet performance requirements, then friction stability and wear resistance are improved, but environmental contamination increases due to copper discharge

Engineering Contradiction:
Improvefriction stabilityVSAvoidenvironmental contamination
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The invention extracts and removes the copper component from the friction material composition entirely, replacing it with alternative materials (zirconium oxide and fluoropolymer particles) that provide necessary friction and wear properties without causing environmental contamination through copper discharge

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention uses a composite material system combining zirconium oxide particles (1-8 μm) as inorganic friction modifier and fluoropolymer particles (10-1000 μm) as lubricant, creating a copper-free composition that maintains friction stability while preventing environmental harm

Inventive Principle:
Principle #40Composite materials

2Object-affected harmful factors

If copper component is reduced in NAO friction material to prevent environmental contamination, then environmental pollution decreases, but friction material performance deteriorates

Engineering Contradiction:
Improveenvironmental pollutionVSAvoidfriction material performance
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The invention changes the particle size parameters of the friction modifiers, using zirconium oxide particles with specific diameter (1-8 μm) and fluoropolymer particles with specific diameter (10-1000 μm), to optimize both environmental performance and friction material reliability without copper

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention employs a composite formulation combining multiple materials (zirconium oxide, fluoropolymer, binder, fiber base) in specific proportions to achieve the required friction performance while maintaining copper-free composition for environmental protection

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 solution effectively reduces copper discharge and prevents just-before-stopping noise, meeting regulatory copper content requirements while maintaining friction material performance.

Implementation Method 1

inhibits water absorption

Methodology Applied
Scientific EffectHydrophobe: Hydrophobe

Implementation Method 2

the fluoropolymer powder prevents the water within the pore of the friction material from being absorbed

Methodology Applied
Scientific EffectWaterproof effect: Hydrophobe

Data Source

PatentUS20230022799A1Friction material
Publication Date: 2023.01.26 NISSHINBO BRAKE INC

AI summary

In the friction material used for the disc brake pad, which is manufactured by forming a non-asbestos-organic (NAO) friction material composition, it is an object of this invention to provide the friction material that satisfies the laws and regulations with respect to the amount of the copper component contained therein and at the same time inhibits the generation of the just-before-stopping noise. In the friction material used for the disc brake pad, which is manufactured by forming a non-asbestos-organic (NAO) friction material composition that contains the binder, the fiber base, the inorganic friction modifier, the organic friction modifier, and the lubricant but does not contain the copper component, the friction material composition contains 0.5-5 weight %, relative to the entire amount of the friction material composition, of the fluoropolymer particle with the average particle diameter of 10-1000 μm as the lubricant and 15-35 weight %, relative to the entire amount of the friction material composition, of the zirconium oxide with the average particle diameter of 1-8 μm as the inorganic friction modifier.