Polyol Composition for Abrasive Foam Density Control
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Solution Overview
Problem
Existing methods for producing urethane abrasive foams using 4,4′-diamino-3,3′-dichlorodiphenylmethane (MBOCA) result in foamed molded articles with increased density variation and non-uniform density distribution due to the reaction between MBOCA and water, leading to inadequate mechanical properties and polishing performance.
Innovation Solution
A polyol composition comprising a polyaminochlorophenylmethane mixture with specific weight ratios of binuclear, trinuclear, and tetranuclear compounds, dissolved in a polyol with an ether bond or methyl group, is used in a two-component mixing casting machine, allowing for uniform mixing and foaming without premature water evaporation, resulting in a urethane foam with improved mechanical properties and uniform density.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If MBOCA is heated to 110°C or higher to liquefy it for mixing, then MBOCA becomes suitable for mixing, but water evaporates and the resulting foam exhibits increased density variation and non-uniform density distribution
Solution Approach 1:
The patent changes the chemical composition parameters by using a polyaminochlorophenylmethane mixture containing trinuclear and tetranuclear compounds instead of pure binuclear MBOCA. This compositional parameter change allows the mixture to remain liquid at lower temperatures, enabling mixing at temperatures below water's boiling point while maintaining uniform density distribution in the final foam.
Solution Approach 2:
The patent employs a composite polyaminochlorophenylmethane mixture comprising multiple nuclear compounds (binuclear, trinuclear, and tetranuclear) with specific weight ratios. This composite material approach creates a formulation that combines the advantages of different compounds, achieving both liquid state at low temperature and uniform foam density distribution.
2Ease of manufacture
If water is added to MBOCA in advance, then the mixture is prepared for foaming, but water reacts with isocyanate groups and evaporates upon heating, preventing desirable foam formation
Solution Approach 1:
The patent changes the temperature parameter by enabling the process to proceed at lower temperatures (below 100°C) due to the lowered melting point of the polyaminochlorophenylmethane mixture. This temperature parameter change prevents water evaporation and maintains reliable foam formation throughout the mixing and casting process.
3Ease of manufacture
If fine particles treated with silicone surfactant are mixed with prepolymer, then foaming is attempted, but uniform mixing is difficult and uniform density distribution is not achieved
Solution Approach 1:
The patent changes the physical state parameter of the polyaminochlorophenylmethane mixture from solid to liquid by adjusting the compositional parameters (including trinuclear and tetranuclear compounds). This liquid state at room temperature or slightly elevated temperatures enables easy and uniform mixing with the prepolymer solution, achieving homogeneous density distribution in the final foam without requiring complex mixing equipment or surfactant treatments.
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 solution achieves a urethane foam with enhanced mechanical properties and uniform density distribution, suitable for precision polishing applications, by ensuring stable dissolution and miscibility of the polyaminochlorophenylmethane mixture with the polyol, preventing precipitation and clogging, and maintaining effective foaming and curing processes.
Implementation Method 1
the polyaminochlorophenylmethane mixture (A) is uniformly dissolved in the polyol (B)
Implementation Method 2
water evaporates upon heating of MBOCA at 110° C., i.e., the melting point of MBOCA, or higher
Implementation Method 3
The mixture is cast in a mold using a casting machine, is foamed and thereby yields a block molded article
Implementation Method 4
water reacts with the isocyanate
Implementation Method 5
the reaction with water (foaming reaction)
Data Source
AI summary
A polyol composition contains a polyaminochlorophenylmethane mixture (A) and a polyol (B), in which the component (A) is uniformly dissolved in the component (A) in a weight ratio of 30/70 to 60/40. The component (A) includes 50 to 70% by weight of a specific binuclear polyaminochlorophenylmethane compound, 20 to 40% by weight of a specific trinuclear polyaminochlorophenylmethane compound and 5 to 10% by weight of a specific tetranuclear or higher polyaminochlorophenylmethane compound. The polyol composition exhibits excellent miscibility and dissolution stability, is liquid and enables molding of a foamed article for abrasive in a simple two-component mixing casting machine. According to the present invention, water serving as a foaming agent can be added to the polyol composition containing MBOCA, and the composition for a two-component curable abrasive foam can be held to a temperature equal to or lower than the boiling point of water, thus avoiding water from evaporating upon molding. The resulting abrasive foam has a uniform density distribution and exhibits excellent mechanical properties. A method for satisfactorily producing such an abrasive foam is also provided.