Polyolefin Pipe Stabilizer System for Low Additive Migration

Solution Overview

Problem

Polyolefin pipes used in drinking water distribution systems face challenges with the migration of additives and their decomposition products, particularly phenolic compounds, into the water, which is a concern due to stricter legal requirements and the need for maintaining stability and process stability without compromising polymer matrix integrity.

Innovation Solution

A polyolefin composition comprising specific combinations of stabilizers, such as N,N-dibenzylhydroxylamine and di(rape-oil) alkyl N-methyl amine oxide, which provide both process-stability and long-term stability while minimizing the migration of phenolic antioxidants and their decomposition products.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If phenolic antioxidants are used to provide long-term stability and process-stability, then the polymer matrix is stabilized, but migration of phenolic compounds and their decomposition products into drinking water increases

Engineering Contradiction:

Improvelong-term stabilityVSAvoidmigration of phenolic compounds

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent removes phenolic antioxidants from the stabilizer combination, extracting the harmful component while maintaining stabilization functionality through alternative compounds (amine oxide and hydroxylamine) that do not migrate into drinking water

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent employs short-chain carboxylic acids (acetic acid, propionic acid, butyric acid) as sacrificial additives that decompose to form protective complexes with metal ions, preventing catalyst residue activity without leaving persistent harmful residues in the water

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

2Reliability

If phenolic antioxidants are used to provide long-term stability, then the polymer matrix is stabilized, but migration of additives and decomposition products into water increases

Engineering Contradiction:

Improvelong-term stabilityVSAvoidmigration of additives

Core Design Contradiction:

ReliabilityVSLoss of substance

Solution Approach 1:

The patent removes phenolic antioxidants from the stabilizer combination, extracting the harmful component while maintaining stabilization functionality through alternative compounds (amine oxide and hydroxylamine) that do not migrate into drinking water

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces short-chain carboxylic acids as intermediary substances that form protective complexes with metal catalyst residues, acting as a mediator that prevents direct interaction between catalyst residues and the polymer matrix, thereby reducing decomposition product formation

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If usual amounts of phenolic antioxidants are used, then process-stability and long-term stability are achieved, but migration into drinking water increases

Engineering Contradiction:

Improveprocess-stabilityVSAvoidmigration of phenolic compounds

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent removes phenolic antioxidants from the stabilizer combination, extracting the harmful component while maintaining stabilization functionality through alternative compounds (amine oxide and hydroxylamine) that do not migrate into drinking water

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the chemical parameters of the stabilizer system by replacing phenolic compounds with amine oxide and hydroxylamine compounds, fundamentally altering the chemical nature of the stabilizers to eliminate migration while maintaining stabilization efficacy

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 achieves low migration of additives and decomposition products, ensuring high thermal and chemical stability of the pipes without the need for usual amounts of phenolic antioxidants, meeting stringent legal requirements and maintaining desired long-term properties.

Implementation Method 1

polymeric compounds are prone to aging under the effects of oxidants, light and heat

Methodology Applied

Scientific EffectOxidation: Oxidation

Implementation Method 2

polymeric compounds are prone to aging under the effects of oxidants, light and heat

Methodology Applied

Scientific EffectLight absorption: Absorption (EM radiation)

Data Source

PatentUS9522988B2Polyolefin pipe with improved migration behaviour

Publication Date: 2016.12.20 BOREALIS AG

AI summary

A polyolefin pipe having a polyolefin base resin (A) including a lower molecular weight fraction and a higher molecular weight fraction, stabilized with at least one stabilizer (B) having a formula:and at least one stabilizer (C) having a formula:wherein the substituents are as described in the specification. The composition demonstrates acceptable stability and low migration of additional additives from the pipe.