Polyester Fiber Composition for Low-Temperature Carrier-Free Dyeing

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Solution Overview

Problem

Existing polyester fiber production methods require complex polymerization steps and high temperatures for dyeing, limiting spinnability, fiber thickness variation, and achieving light- and washfastness.

Innovation Solution

A process involving mixing terephthalate polyester with a polyester-containing additive, melting, and extruding through spinneret dies to produce fibers that can be dyed at temperatures below 130°C without carriers, using a disperse dye in an exhaust process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If complex copolymers are used to enable low-temperature dyeing, then dyeability at below 130°C is improved, but device complexity and manufacturing complexity increase

Engineering Contradiction:
Improvedyeing temperatureVSAvoidpolymerization process complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The patent extracts the dye-receptor function from the polymer backbone by incorporating a small amount (0.01-5 wt%) of specific comonomer units (carboxylic acid groups) into the polyester chain. These extracted functional groups serve as dedicated dye-binding sites while the bulk polyester structure remains simple and easy to manufacture.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the chemical composition parameters of the polyester by introducing specific comonomers with carboxylic acid groups (such as hydroxyisophthalic acid, hydroxynaphthalene-2,6-dicarboxylic acid) in controlled amounts. This parameter change enables low-temperature dyeing while maintaining simple polymerization processes using standard catalysts and conditions.

Inventive Principle:
Principle #35Parameter changes

2Ease of manufacture

If complex copolymers are used to achieve dyeability without carriers, then dyeing process simplicity is improved, but manufacturing precision and fiber quality control worsen

Engineering Contradiction:
Improvedyeing process easeVSAvoidfiber thickness control
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent applies local quality by concentrating the functional comonomer units (carboxylic acid groups) at specific locations within the polymer chain where they can effectively bind dyes, while keeping the majority of the polymer structure as simple, well-controlled polyester units. This localized functionalization achieves dyeability without compromising overall fiber manufacturing precision.

Inventive Principle:
Principle #3Local quality

3Ease of manufacture

If standard polyester fibers are used, then spinnability is maintained, but dyeing temperature requirements increase to 130°C or more

Engineering Contradiction:
ImprovespinnabilityVSAvoiddyeing temperature
Core Design Contradiction:
Ease of manufactureVSTemperature

Solution Approach 1:

The patent creates a composite polyester material combining the bulk polyester matrix (providing spinnability and mechanical properties) with embedded comonomer units containing carboxylic acid groups (providing low-temperature dyeability). This composite structure integrates both required functions: easy spinning and low-temperature dyeing without carriers.

Inventive Principle:
Principle #40Composite materials

4Reliability

If high dyeing temperatures are used, then dye penetration is achieved, but energy consumption increases

Engineering Contradiction:
Improvedye penetrationVSAvoiddyeing energy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent enables the polyester fiber to self-facilitate dye penetration at low temperatures through the inherent carboxylic acid groups in the comonomer units. These functional groups automatically provide dye-binding sites without requiring external carriers or high temperature energy input, making the dyeing process energy-efficient.

Inventive Principle:
Principle #25Self-service

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 process simplifies fiber production, reduces energy requirements, and achieves intensive, uniform dyeability with good rubfastness and washfastness, maintaining fiber suppleness and allowing for a wide color spectrum.

Implementation Method 1

The incorporated comonomer is also the receptor site for a cationic dye

Methodology Applied
Scientific EffectAbsorption: Absorption (physical)

Implementation Method 2

cationic dyes which bind to the comonomer

Methodology Applied
Scientific EffectChemical bonding: Chemical Bonding

Implementation Method 3

A melt is formed by heating and extruded through spinneret dies

Methodology Applied
Scientific EffectExtrusion: Extrusion

Implementation Method 4

A melt is formed by heating

Methodology Applied
Scientific EffectMelting: Melting

Data Source

PatentUS10202712B2Producing spinnable and dyeable polyester fibers
Publication Date: 2019.02.12 BASF SE

AI summary

The present invention relates to a process for producing dyed polyester fibers (C) from a terephthalate polyester (A), at least one polyester-containing additive (B) and optionally at least one component (G). The polyester-containing additive is obtainable by condensation of the monomers of an aliphatic 1,ω-diol, of an aliphatic 1,ω-dicarboxylic acid and of an aromatic 1,ω-dicarboxylic acid. Optionally, chain extenders (V) are also used in the production of the polyester-containing additive (B). For fiber production, the components (A), (B) and optionally (G) are mixed, melted in an extruder and extruded through spinneret dies. These polyester fibers (C) are preferably used in the production of dyed textile fabrics (F).