Halogen-Free Flame Retardant Polypropylene for Laser Marking

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Solution Overview

Problem

Current flame retardant polypropylene compositions for electrical applications often contain halogens, which are subject to restrictions, and lack suitable compatibility with laser marking processes, especially in terms of mechanical strength and environmental friendliness.

Innovation Solution

A halogen-free or low-halogen flame retardant polypropylene composition comprising a polypropylene polymer, a nitrogen-containing flame retardant, carbon black, and optionally glass fibers, optimized for laser marking and improved mechanical strength.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If halogen-containing flame retardants are used to achieve flame retardancy, then flame retardant performance is improved, but environmental friendliness deteriorates due to REACH restrictions on PFAS and halogen compounds

Engineering Contradiction:
Improveflame retardant performanceVSAvoidenvironmental friendliness
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the chemical composition parameters by completely replacing halogen-containing flame retardants with halogen-free alternatives (specifically phosphorus-nitrogen synergistic flame retardants). This parameter change achieves both flame retardancy (UL 94 V-0 rating) and environmental compliance (free from restricted PFAS and halogen compounds under REACH regulations).

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs a composite flame retardant system combining phosphorus-containing compounds (such as phosphoric acid, phosphorous acid, or their esters) with nitrogen-containing compounds (such as melamine, cyanuric acid, or biguanide). This composite approach creates synergistic effects that achieve superior flame retardant performance without relying on restricted halogenated materials.

Inventive Principle:
Principle #40Composite materials

2Reliability

If conventional flame retardant polypropylene compositions are used, then flame retardancy is achieved, but compatibility with laser marking processes deteriorates due to poor mechanical strength and ink peeling issues

Engineering Contradiction:
Improveflame retardancyVSAvoidlaser marking compatibility
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent optimizes the formulation parameters by controlling the specific combination of phosphorus and nitrogen flame retardant ratios, adding carbon black as a laser absorption enhancer (0.1-5.0 wt%), and adjusting polypropylene polymer characteristics. These parameter changes enable effective laser marking with improved contrast and adhesion while maintaining flame retardant performance.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces carbon black as an intermediary substance that facilitates laser marking on the flame retardant polypropylene surface. Carbon black serves as a mediator that absorbs laser energy and transfers it to the underlying polymer matrix, enabling effective marking without compromising the flame retardant properties or causing ink peeling.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If high amounts of flame retardants are added to achieve flame retardancy, then flame retardant performance is improved, but mechanical strength deteriorates

Engineering Contradiction:
Improveflame retardant performanceVSAvoidmechanical strength
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent uses a composite phosphorus-nitrogen flame retardant system where the synergistic interaction between phosphorus-containing and nitrogen-containing compounds allows achieving UL 94 V-0 flame retardancy with lower total flame retardant loading compared to single-system approaches. This composite strategy reduces the burden on mechanical properties while maintaining superior flame safety.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent optimizes the concentration parameters of individual flame retardant components, specifically controlling the ratio and amounts of phosphorus-containing compounds (0.5-5.0 wt%) and nitrogen-containing compounds (0.5-5.0 wt%). This precise parameter control achieves effective flame retardancy with minimized impact on mechanical strength by avoiding excessive total additive loading.

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 is environmentally friendly, suitable for laser marking, enhances mechanical strength, and reduces CO2 footprint, weight, and costs while avoiding fluoropolymers.

Implementation Method 1

Laser marking methods are processes that use laser light to place marks, bar codes or data matrix codes on the surface of metal, ceramic, macromolecular organic materials or the like

Methodology Applied
Scientific EffectLight absorption: Absorption (EM radiation)

Data Source

PatentEP4491663A1Flame retardant polypropylene composition having laser-marking capability
Publication Date: 2025.01.15 BOREALIS GMBH
  • EP4491663A1 patent drawingFigure 1~2
  • EP4491663A1 patent drawingFigure 3
  • EP4491663A1 patent drawing

AI summary

The present invention concerns a flame retardant polypropylene composition comprising a polypropylene polymer, a nitrogen-containing flame retardant carbon black and optionally glass fibers and an article comprising the flame retardant polypropylene composition.