Cerium Lanthanum Mixed Oxide Abrasive Particles

Solution Overview

Problem

Cerium-based particles used in polishing formulations face challenges with abrasive capacity and defectuosity, as particles that are too fine reduce abrasive effectiveness while larger particles increase surface scratches.

Innovation Solution

Development of mixed oxide particles of cerium and lanthanum with a specific molar ratio, specific surface area, and cubic shape, characterized by a molar ratio La/(La+Ce) between 0.01 and 0.15, a BET surface area of 3-14 m2/g, and a shape with four sides of equal length forming 90° angles, which are dispersed in a liquid medium.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If particles are made finer to reduce surface scratches, then defectuosity decreases, but abrasive capacity is reduced

Engineering Contradiction:

Improvesurface scratchesVSAvoidabrasive capacity

Core Design Contradiction:

Object-affected harmful factorsVSProductivity

Solution Approach 1:

The invention optimizes the particle size parameter to a specific range (100-300 nm) and controls the size distribution (sigma/m ratio) to balance abrasive capacity and surface quality. This parameter optimization resolves the contradiction by finding the optimal particle dimensions that provide sufficient material removal while minimizing scratches.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention uses mixed oxide particles comprising cerium oxide and lanthanum oxide in specific ratios, creating a composite material with enhanced properties. This composite approach allows the particles to achieve both high abrasive capacity and low defectuosity simultaneously, resolving the trade-off between material removal efficiency and surface quality.

Inventive Principle:

Principle #40Composite materials

2Productivity

If particles are made larger to increase abrasive capacity, then material removal rate improves, but surface defectuosity increases

Engineering Contradiction:

Improvematerial removal rateVSAvoidsurface scratches

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The invention optimizes the particle size parameter to a specific range (100-300 nm) and controls the size distribution (sigma/m ratio) to balance abrasive capacity and surface quality. This parameter optimization resolves the contradiction by finding the optimal particle dimensions that provide sufficient material removal while minimizing scratches.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention uses mixed oxide particles comprising cerium oxide and lanthanum oxide in specific ratios, creating a composite material with enhanced properties. This composite approach allows the particles to achieve both high abrasive capacity and low defectuosity simultaneously, resolving the trade-off between material removal efficiency and surface quality.

Inventive Principle:

Principle #40Composite materials

3Productivity

If specific surface area is increased to improve polishing performance, then abrasive efficiency improves, but particle size control becomes more difficult

Engineering Contradiction:

Improvepolishing efficiencyVSAvoidparticle size control

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The invention optimizes the particle size parameter to a specific range (100-300 nm) and controls the size distribution (sigma/m ratio) to balance abrasive capacity and surface quality. This parameter optimization resolves the contradiction by finding the optimal particle dimensions that provide sufficient material removal while minimizing scratches.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS11578235B2Cerium based particles

Publication Date: 2023.02.14 RHODIA OPERATIONS SAS

AI summary

The present invention relates to cerium-based particles and their use as a component of a composition for polishing. The present invention also relates to the method of preparation of the cerium-based particles.