Bismuth Vanadate Pigment Stabilization in Thermoplastics

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Solution Overview

Problem

Bismuth vanadate pigments in thermoplastic molding compositions, particularly polyamide compositions, suffer from thermal degradation issues when boric acid is not used for stabilization, and alternative stabilization methods are needed to maintain color stability during processing and storage.

Innovation Solution

A bismuth vanadate pigment composition is stabilized by dispersing it in a copolymer of ethylene with (meth)acrylic acid, C1-12 alkyl (meth)acrylates, or maleic anhydride, which provides thermal stability and improved color retention in thermoplastic polymers during processing and storage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If boric acid is used to stabilize bismuth vanadate pigment in thermoplastic molding compositions, then thermal stability is improved, but the use of boric acid is discouraged due to environmental and health concerns

Engineering Contradiction:
Improvethermal stabilityVSAvoidboric acid content
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The invention extracts and removes boric acid from the stabilization system while maintaining thermal stability through alternative means. The patent specifically addresses the problem of replacing boric acid with a bismuth vanadate masterbatch that achieves stability without this harmful substance.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces an intermediary stabilization mechanism using a coating comprising an anti-oxidant on the bismuth oxy halide pigment, which mediates between the pigment and thermal degradation conditions, preventing direct thermal damage without requiring boric acid.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If bismuth vanadate pigment is used without boric acid stabilization, then environmental safety is improved, but thermal degradation occurs rapidly

Engineering Contradiction:
Improveboric acid contentVSAvoidthermal stability
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

An anti-oxidant coating is applied to the bismuth oxy halide pigment to serve as an intermediary protective layer that prevents thermal degradation without requiring boric acid. This coating mediates the interaction between the pigment and harsh thermal processing conditions.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the stabilization mechanism from chemical (boric acid) to physical/chemical coating (anti-oxidant layer), altering how the pigment is protected during thermal processing while eliminating the harmful substance.

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If bismuth vanadate pigment is dispersed in polyethylene masterbatch, then processing is simplified, but thermal degradation is not prevented

Engineering Contradiction:
Improvemasterbatch preparationVSAvoidthermal stability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The anti-oxidant coating acts as an intermediary protective barrier on the pigment particles within the polyethylene masterbatch, enabling simplified processing while preventing thermal degradation that would otherwise occur in standard polyethylene systems.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 bismuth vanadate pigment composition maintains stability and color integrity in thermoplastic polymers, preventing thermal degradation and ensuring consistent performance in injection molding and other processing methods.

Implementation Method 1

bismuth vanadate pigment dispersed in a copolymer of ethylene with at least one comonomer, selected from the group consisting of (meth)acrylic acid, C 1-12 -alkyl (meth)acrylates and maleic anhydride

Methodology Applied
Scientific EffectDispersion: Dispersion (of waves)

Implementation Method 2

the resulting pigment composition is stable against thermal degradation upon storage, upon inclusion in thermoplastic polymers and upon processing of the thermoplastic polymer

Methodology Applied
Scientific EffectThermal stability:

Data Source

PatentEP3953415B1Yellow pigment composition
Publication Date: 2023.03.22 BASF SE

AI summary

Pigment composition, comprising bismuth vanadate pigment dispersed in a copolymer of ethylene with at least one comonomer, selected from the group consisting of (meth)acrylic acid, C1-12-alkyl (meth)acrylates and maleic anhydride.