Polishing Slurry with Accelerant and Buffer for Zirconia

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Solution Overview

Problem

Conventional abrasive slurries used in material removal operations, such as polishing, often face limitations in achieving optimal material removal rates and surface finish, particularly when dealing with inorganic materials like zirconia, due to the lack of effective accelerants and buffers that enhance chemical interactions and control dissociation processes.

Innovation Solution

A composition comprising a liquid carrier, silica abrasive particulate, an accelerant (like fluoride) with a solubility of 0.002 M to 1.0 M, and a buffer (such as KBF4) with solubility less than 10 g/L, which dissociates to form ionic species facilitating improved material removal and surface finish during polishing processes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional abrasive slurries are used without accelerants and buffers, then the composition is simpler and easier to manufacture, but the material removal rate and surface finish are suboptimal

Engineering Contradiction:
Improvematerial removal rateVSAvoidcomposition complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent applies parameter changes by introducing specific chemical components (accelerants and buffers) with controlled concentrations and solubility characteristics. The accelerant concentration is optimized at 0.002 M to 1.0 M, and the buffer solubility is controlled at less than 10 g/L, creating controlled chemical environments that significantly enhance material removal rates while maintaining manageable composition complexity

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs composite material principles by combining silica abrasive particulate with accelerants and buffers in a liquid carrier to create a multi-component slurry system. This composite composition leverages the synergistic effects of different materials - the abrasive for mechanical removal, the accelerant for enhanced chemical interaction, and the buffer for controlled dissociation - achieving superior polishing performance

Inventive Principle:
Principle #40Composite materials

2Productivity

If accelerants with high solubility are used, then chemical interaction is enhanced, but controlled dissociation becomes difficult and material removal may be uncontrollable

Engineering Contradiction:
Improvematerial removal rateVSAvoiddissociation control
Core Design Contradiction:
ProductivityVSStability of the object's composition

Solution Approach 1:

The patent applies parameter changes by carefully selecting accelerant concentrations within the range of 0.002 M to 1.0 M and using buffers with solubility less than 10 g/L. These parameter optimizations enable enhanced chemical interaction while maintaining controlled dissociation, resolving the contradiction between reactivity and compositional stability

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces a buffer as an intermediary substance that mediates between the accelerant and the substrate. The buffer controls the dissociation process and maintains stable chemical environments, allowing the accelerant to enhance material removal rates without causing uncontrollable reactions

Inventive Principle:
Principle #24Intermediary (Mediator)

3Stability of the object's composition

If buffers with low solubility are used, then dissociation is controlled, but the effectiveness of chemical interaction may be reduced

Engineering Contradiction:
Improvedissociation controlVSAvoidmaterial removal rate
Core Design Contradiction:
Stability of the object's compositionVSProductivity

Solution Approach 1:

The patent optimizes the buffer solubility parameter to be less than 10 g/L, which provides sufficient dissociation control while maintaining adequate chemical interaction effectiveness. This parameter optimization resolves the contradiction between composition stability and productivity

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 composition significantly enhances the material removal rate and surface finish of zirconia, as demonstrated by a 43% increase in material removal rate and a reduced surface roughness of 9.9 Å, compared to compositions without the accelerant and buffer, indicating improved chemical interaction and controlled dissociation.

Implementation Method 1

an accelerant contained in the carrier, the accelerant comprising an anion present in a concentration of 0.002 M to 1.0 M

Methodology Applied
Scientific EffectDissociation:

Implementation Method 2

chemically and mechanically interacting with the substrate film being planarized

Methodology Applied
Scientific EffectChemical interaction:

Implementation Method 3

a buffer contained in the carrier, wherein the buffer has a solubility of less than 10 g/L according to ASTM standard E1148

Methodology Applied
Scientific EffectSolubility control:

Implementation Method 4

an abrasive particulate contained in the carrier, wherein the abrasive particulate comprises silica

Methodology Applied
Scientific EffectAbrasion: Abrasion

Implementation Method 5

The relative movement of the slurry to the substrate assists with the planarization (polishing) process

Methodology Applied
Scientific EffectWear: Wear

Data Source

PatentEP3700990B1Composition for conducting material removal operations and method for forming same
Publication Date: 2023.03.29 SAINT GOBAIN CERAMICS & PLASTICS INC
  • EP3700990B1 patent drawingFigure 1

AI summary

A composition including a carrier comprising a liquid, an abrasive particulate contained in the carrier, an accelerant contained in the carrier, the accelerant including at least one free anion selected from the group of iodide (I -), bromide (Br- ), fluoride (F-), sulfate (S04 2-), sulfide (S2-), sulfite (S03 2-), chloride (C1-), silicate (Si04 4-), phosphate (P04 3-), nitrate (N03 - ), carbonate (C03 2-), perchlorate (C104 -), or any combination thereof, and a buffer contained in a saturated concentration in the carrier, the buffer including a compound selected from MaFx, NbFx, MaNbFx, MaIx, NbIx, MaNbIx, MaBrx, NbBrx, MaNbBrx, Ma(S04)x, Nb(S04)x, MaNb(S04)x, MaSx, NbSx, MaNbSx, Ma(Si04)x, Nb(Si04)x, MaNb(Si04)x, Ma(P04)x, Nb(P04)x, MaNb(P04)x, Ma(N03)x, Nb(N03)x, MaNb(N03)x, Ma(C03)x, Nb(C03)x, MaNb(C03)x, or any combination, wherein M represents a metal element or metal compound; N represents a non- metal element; and a, b, and x is 1-6.