Polycarbonate Resin Using Inositol Derivatives for UV Stability

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Solution Overview

Problem

Conventional polycarbonate resins deteriorate in hue, transparency, and mechanical strength when exposed to ultraviolet rays, and their light resistance is compromised due to the benzene ring structure in bisphenol compounds, while using aliphatic or alicyclic dihydroxy compounds as alternatives leads to trade-offs in heat resistance and biomass resource utilization.

Innovation Solution

A polycarbonate resin is developed using an inositol derivative with specific structural units, such as those represented by formulae (1) to (4), which enhance heat resistance, transparency, light resistance, and mechanical strength, and includes a high ratio of myo-inositol-derived structures, optimizing the molecular composition to maintain heat resistance and reduce water absorptivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a benzene ring structure (bisphenol compound) is used in polycarbonate resin, then mechanical strength and heat resistance are improved, but light resistance deteriorates due to ultraviolet absorption

Engineering Contradiction:
Improvemechanical strengthVSAvoidlight resistance
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The invention changes the chemical structure parameter by replacing the benzene ring structure with an alicyclic structure (cyclohexane ring). This structural parameter change eliminates ultraviolet absorption while maintaining mechanical strength and heat resistance, thereby resolving the contradiction between strength and light resistance

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention creates a copy of the benzene ring's functional properties (strength and heat resistance) using an alicyclic structure. The cyclohexane ring mimics the structural rigidity and thermal stability of aromatic rings without exhibiting their harmful ultraviolet absorption characteristics

Inventive Principle:
Principle #26Copying

2Reliability

If an aliphatic or alicyclic dihydroxy compound is used as a raw material monomer, then light resistance is improved, but heat resistance is sacrificed

Engineering Contradiction:
Improvelight resistanceVSAvoidheat resistance
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

The invention optimizes the parameter of the alicyclic structure by using specifically substituted cyclohexane rings with alkyl groups. This parameter optimization enhances the glass transition temperature and heat resistance while preserving the excellent light resistance inherent to alicyclic structures

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention creates a composite molecular structure combining alicyclic rings with alkyl substituents. This composite structure integrates the light resistance of alicyclic compounds with the heat resistance contributed by the alkyl groups and the carbonate linkage, resolving the contradiction between light resistance and heat resistance

Inventive Principle:
Principle #40Composite materials

3Temperature

If only isosorbide is used as a raw material monomer, then heat resistance is enhanced (Tg exceeds 160°C), but impact resistance becomes low and water absorptivity increases

Engineering Contradiction:
Improveheat resistanceVSAvoidimpact resistance
Core Design Contradiction:
TemperatureVSStrength

Solution Approach 1:

The invention segments the polymer structure by incorporating different alicyclic dihydroxy compounds with distinct molecular characteristics. This segmentation creates a more balanced polymer network that distributes stress more effectively, improving impact resistance while maintaining heat resistance through the alicyclic structure

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention introduces local structural variations by using differently substituted cyclohexane rings at specific positions in the polymer chain. This local quality adjustment optimizes the balance between heat resistance (maintained by alicyclic structures) and impact resistance (improved by strategic placement of flexible alkyl groups)

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3235849B1Polycarbonate resin
Publication Date: 2019.06.26 MITSUBISHI CHEM CORP
  • EP3235849B1 patent drawingFigure 1
  • EP3235849B1 patent drawingFigure 2
  • EP3235849B1 patent drawingFigure 3

AI summary

To provide a polycarbonate resin excellent in heat resistance, transparency, light resistance, weather resistance and mechanical strength. The present invention relates to a polycarbonate resin containing, in the molecule, a structure represented by the following formula (1). (In the formula (1), X has a structure represented by any one of the following formulae (2) to (4). In the formulae (2) to (4), each of R1 to R4 independently represents a hydrogen atom or an organic group having a carbon number of 1 to 30. The organic group may have an arbitrary substituent, and any two or more members of R1 to R4 may combine with each other to form a ring).