Polycarbonate/Polyoxyethylene Block Copolymer for Aqueous Formulations

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Solution Overview

Problem

Existing polycarbonate diols lack improvements in water dilutability and stability when used in aqueous formulations, despite the shift towards aqueous formulations for environmental and health safety reasons.

Innovation Solution

A polycarbonate/polyoxyethylene block copolymer with a specified structure, where both terminals are substantially hydroxyl groups, is developed, enhancing water dilutability and stability in aqueous compositions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional polycarbonate diols are used in aqueous formulations, then the polyurethane product achieves good hydrolysis resistance, heat resistance, and weather resistance, but the water dilutability and stability in aqueous formulation are insufficient

Engineering Contradiction:

Improvehydrolysis resistance, heat resistance, weather resistanceVSAvoidwater dilutability, stability in aqueous formulation

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The invention creates a block copolymer that combines polycarbonate segments (providing hydrolysis resistance, heat resistance, and weather resistance) with polyoxyethylene segments (providing water solubility and compatibility with aqueous formulations). This composite structure allows the material to simultaneously achieve both the durability characteristics of polycarbonate and the water compatibility of polyoxyethylene, resolving the contradiction between reliability and adaptability in aqueous environments

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The block copolymer structure creates different functional regions within the same molecule: polycarbonate blocks provide localized regions of high durability and resistance to degradation, while polyoxyethylene blocks provide localized regions of water solubility and hydrophilicity. This local differentiation of properties allows the material to exhibit both water dilutability and excellent resistance properties simultaneously

Inventive Principle:

Principle #3Local quality

2Adaptability or versatility

If the polycarbonate diol structure is modified to improve water dilutability, then the stability in aqueous formulation improves, but the reactivity with crosslinking agents may be affected

Engineering Contradiction:

Improvewater dilutability, stability in aqueous formulationVSAvoidreactivity with crosslinking agents

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The invention carefully controls the parameters of the block copolymer, specifically the molecular weight of each block, the ratio of polycarbonate to polyoxyethylene segments, and the degree of terminal hydroxyl group substitution. By optimizing these parameters, the material achieves adequate water dilutability while preserving sufficient hydroxyl group reactivity for crosslinking reactions, thus resolving the contradiction between adaptability and reliability

Inventive Principle:

Principle #35Parameter changes

3Strength

If a polycarbonate diol with high molecular weight is used to maintain mechanical properties, then the elasticity and adhesiveness improve, but the water dilutability decreases

Engineering Contradiction:

Improveelasticity, adhesiveness, scratch resistanceVSAvoidwater dilutability

Core Design Contradiction:

StrengthVSAdaptability or versatility

Solution Approach 1:

The invention segments the polymer into distinct blocks with different functions: polycarbonate blocks that provide mechanical strength, elasticity, and adhesiveness, and polyoxyethylene blocks that provide water solubility. This segmentation allows each block to optimize its contribution without being constrained by the other, enabling high molecular weight polycarbonate blocks to maintain mechanical properties while polyoxyethylene blocks ensure water dilutability

Inventive Principle:

Principle #1Segmentation

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 polycarbonate/polyoxyethylene block copolymer exhibits excellent water dilutability and stability, allowing for effective use in aqueous compositions, coatings, inks, and adhesives, while maintaining reactivity with crosslinking agents.

Implementation Method 1

a polycarbonate/polyoxyethylene block copolymer comprising a polycarbonate structure and a polyoxyethylene structure

Methodology Applied

Scientific EffectTransesterification: Chemical Bonding

Data Source

PatentEP3141574B1Polycarbonate/polyoxy ethylene block copolymer for aqueous compositions, and aqueous composition, aqueous coating composition, aqueous ink composition, and aqueous tackifier composition comprising the same

Publication Date: 2019.07.10 ASAHI KASEI KOGYO KABUSHIKI KAISHA

AI summary

Provided is a polycarbonate/polyoxyethylene block copolymer for an aqueous composition, containing a polycarbonate structure represented by the following general formula (1) and a polyoxyethylene structure represented by the following general formula (2), in which each of both terminals is substantially a hydroxyl group: -(R-O-CO-O)m- (1) wherein R may be the same or different and represents a divalent aliphatic hydrocarbon group having 2 to 15 carbon atoms and optionally having a branched chain, a divalent alicyclic hydrocarbon group, or a divalent aromatic hydrocarbon group, and m represents a number; and -(CH2-CH2-O)n- (2) wherein n represents a number.