Polycarbonate diol composition and coating material composition comprising same
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Solution Overview
Problem
Polycarbonate diols used in coating materials can become turbid or crystallize at low temperatures, leading to stability issues and incompatibility with acrylic polyols, which affects their performance in coating compositions.
Innovation Solution
A polycarbonate diol composition with a specific structure, comprising a polycarbonate diol and a diol component, where 90% of terminal groups are hydroxy groups, and the diol component is within specific mass proportions, ensuring stability and compatibility with acrylic polyols, as determined by gel permeation chromatography measurements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If polycarbonate diol is used as a base agent for urethane coating material compositions, then excellent flexibility, weather resistance, hydrolysis resistance, oil resistance, and chemical resistance are achieved, but the material becomes white turbid or crystallized when stored at low temperature
Solution Approach 1:
The invention changes the chemical composition parameters by introducing a specific diol component (formula B) with controlled proportions (0.1-20% by mass) into the polycarbonate diol system. This compositional parameter change prevents crystallization at low temperatures while maintaining the desired transparency and liquid state, resolving the contradiction between stability and physical state.
Solution Approach 2:
The invention creates a composite polycarbonate diol composition by combining polycarbonate diol (formula A) with a specific diol component (formula B) in defined proportions. This composite structure prevents the phase separation and crystallization that occurs in pure polycarbonate diol at low temperatures, thereby maintaining transparency and stability.
2Reliability
If polycarbonate diol is used in coating material compositions, then good adhesion and durability are achieved, but compatibility with acrylic polyol is poor
Solution Approach 1:
The diol component (formula B) acts as an intermediary substance that bridges the incompatibility between polycarbonate diol and acrylic polyol. By incorporating this intermediate component in specific proportions, the invention enables compatible mixing of previously incompatible polymers while maintaining composition stability and preventing phase separation.
3Reliability
If polycarbonate diol becomes turbid or crystallized at low temperature, then storage stability is compromised, but coating performance may be maintained
Solution Approach 1:
The invention modifies the compositional parameters by adding the diol component (formula B) in controlled amounts (0.1-20% by mass), which changes the freezing point and crystallization behavior of the system. This parameter change prevents composition heterogeneity and maintains homogeneous liquid state during storage, thereby ensuring both storage stability and composition stability.
Data Source
AI summary
Provided is a polycarbonate diol composition comprising a polycarbonate diol represented by a specific formula and a diol component represented by a specific formula, wherein 90% by mol or more of the total quantity of terminal groups is hydroxy groups, a hydroxy value is 10 to 400 mg-KOH/g, a proportion of the polycarbonate diol is 80% by mass or more and 99.90% by mass or less and a proportion of the diol component is 0.10% by mass or more and 20% by mass or less based on 100% by mass in total of the carbonate diol and the diol component.