Cellulose Ester Compositions with Polymeric Plasticizer

Solution Overview

Problem

Cellulose ester compositions typically have low heat deflection temperatures and are prone to plasticizer exudation due to high levels of monomeric plasticizer, limiting their applications and causing processing issues.

Innovation Solution

Incorporating polybutylene succinate family polymers into cellulose acetate propionate compositions reduces the need for monomeric plasticizer, maintaining high glass transition temperatures and toughness while preventing exudation, and enhancing mechanical properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If high levels of monomeric plasticizer are added to cellulose ester compositions, then the compositions become melt processable and exhibit sufficient toughness, but the heat deflection temperature decreases and plasticizer exudation occurs

Engineering Contradiction:

Improvemelt processabilityVSAvoidheat deflection temperature

Core Design Contradiction:

Ease of manufactureVSTemperature

Solution Approach 1:

The patent changes the molecular weight parameter of the plasticizer from monomeric to polymeric scale, specifically using polymeric aliphatic polyester (PAP) with controlled molecular weight and polydispersity index. This parameter change allows the plasticizer to provide sufficient toughness and melt processability while maintaining heat deflection temperatures above 90°C and preventing exudation, as the polymeric structure prevents phase separation and migration that occurs with monomeric plasticizers.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite material system combining cellulose ester with polymeric aliphatic polyester (PAP) and potentially other polymers or additives. This composite approach allows the PAP to function as a plasticizer while its polymeric nature provides thermal stability and eliminates exudation issues. The composite structure enables simultaneous achievement of melt processability, toughness, and thermal stability that cannot be obtained with conventional monomeric plasticizers alone.

Inventive Principle:

Principle #40Composite materials

2Ease of manufacture

If high levels of monomeric plasticizer are added to cellulose ester compositions, then the compositions become melt processable and exhibit sufficient toughness, but plasticizer exudation occurs during processing and use

Engineering Contradiction:

Improvemelt processabilityVSAvoidresistance to plasticizer exudation

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent changes the molecular weight parameter of the plasticizer from monomeric to polymeric scale, specifically using polymeric aliphatic polyester (PAP) with controlled molecular weight and polydispersity index. This parameter change allows the plasticizer to provide sufficient toughness and melt processability while maintaining heat deflection temperatures above 90°C and preventing exudation, as the polymeric structure prevents phase separation and migration that occurs with monomeric plasticizers.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite material system combining cellulose ester with polymeric aliphatic polyester (PAP) and potentially other polymers or additives. This composite approach allows the PAP to function as a plasticizer while its polymeric nature provides thermal stability and eliminates exudation issues. The composite structure enables simultaneous achievement of melt processability, toughness, and thermal stability that cannot be obtained with conventional monomeric plasticizers alone.

Inventive Principle:

Principle #40Composite materials

3Reliability

If the amount of monomeric plasticizer is reduced to eliminate exudation, then plasticizer exudation is prevented, but the toughness of the composition decreases

Engineering Contradiction:

Improveresistance to plasticizer exudationVSAvoidtoughness

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

The patent changes the molecular weight parameter of the plasticizer from monomeric to polymeric scale, specifically using polymeric aliphatic polyester (PAP) with controlled molecular weight and polydispersity index. This parameter change allows the plasticizer to provide sufficient toughness and melt processability while maintaining heat deflection temperatures above 90°C and preventing exudation, as the polymeric structure prevents phase separation and migration that occurs with monomeric plasticizers.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite material system combining cellulose ester with polymeric aliphatic polyester (PAP) and potentially other polymers or additives. This composite approach allows the PAP to function as a plasticizer while its polymeric nature provides thermal stability and eliminates exudation issues. The composite structure enables simultaneous achievement of melt processability, toughness, and thermal stability that cannot be obtained with conventional monomeric plasticizers alone.

Inventive Principle:

Principle #40Composite materials

Data Source

PatentUS11873390B2Cellulose ester and polymeric aliphatic polyester compositions and articles

Publication Date: 2024.01.16 EASTMAN CHEM CO

AI summary

A cellulose ester composition is provided comprising at least one cellulose ester, at least one polymeric aliphatic polyester, at least one impact modifier, and at least one monomeric plasticizer. Processes for producing the cellulose ester compositions as well as articles made using these compositions, such as eyeglass or sunglass frames and/or lenses, are also provided.