Styrenic Resin Foam with Gas Barrier Layer
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Solution Overview
Problem
Existing methods for producing styrenic resin foams with low thermal conductivity and long-lasting heat insulation and flame retardancy using eco-friendly blowing agents face challenges, as they either compromise on thermal conductivity or flame retardancy due to the dissipation of blowing agents and air infiltration.
Innovation Solution
A styrenic resin foam is produced using a styrene-(meth)acrylic ester copolymer or a combination with polymethyl methacrylate, with a (meth)acrylic ester component at a specific ratio, mixed with a blowing agent and a flame retardant, to achieve a low thermal conductivity and maintain heat insulation and flame retardancy over time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If isobutane or isopentane are used as blowing agents to achieve low thermal conductivity, then heat insulating properties are improved, but flame retardancy deteriorates due to high flammability
Solution Approach 1:
The patent uses a composite blowing agent system combining isobutane (5-20 mass%) for low thermal conductivity with HFC-134a (80-95 mass%) for flame retardancy. This composite approach allows the foam to achieve both excellent heat insulation properties and sufficient flame retardancy, as the HFC-134a component provides fire resistance while the isobutane component maintains low thermal conductivity.
2Temperature
If isobutane or isopentane are used as blowing agents to achieve low thermal conductivity, then heat insulating properties are improved, but heat insulation performance deteriorates over time due to blowing agent dissipation and air infiltration
Solution Approach 1:
The patent introduces a gas barrier resin layer as an intermediary between the foam cells and the external environment. This layer, having lower gas permeability than the base resin, prevents the dissipation of isobutane and infiltration of air, thereby maintaining the heat insulation performance over time while allowing the use of isobutane for low thermal conductivity.
3Object-affected harmful factors
If CFCs are used as blowing agents to achieve low thermal conductivity and good flame retardancy, then heat insulating properties and flame retardancy are improved, but environmental sustainability deteriorates due to ozone depletion
Solution Approach 1:
The patent changes the chemical composition parameters of the blowing agent system, transitioning from CFCs (high ozone depletion potential) to a mixture of isobutane (zero ozone depletion potential) and HFC-134a (zero ozone depletion potential). This parameter change maintains the functional properties of low thermal conductivity and flame retardancy while eliminating ozone depletion harm.
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 effectively reduces thermal conductivity and maintains excellent heat insulation and flame retardancy in styrenic resin foams, making them suitable for building insulation materials while meeting environmental sustainability criteria.
Implementation Method 1
the foamable molten resin composition is extruded and foamed through, for example, a slit die provided at the tip of the extruder into a low-pressure region
Implementation Method 2
keeping excellent heat insulation performance over a long period of time and flame retardancy
Data Source
AI summary
The present invention relates to an extruded styrenic resin foam and a method for producing the same, wherein a base resin composing the extruded styrenic resin foam is a styrenic resin mixture of a styrene-(meth)acrylic ester copolymer, or a combination of a styrene-(meth)acrylic ester copolymer and polymethyl methacrylate, and a styrenic resin except the styrene-(meth)acrylic ester copolymer, and the styrenic resin mixture contains a (meth)acrylic ester component at a ratio of 4 to 45% by weight with reference to the styrenic resin mixture. The present invention provides an extruded styrenic resin foam having an apparent density of 20 to 60 kg/m3, a thickness of 10 to 150 mm, and a low thermal conductivity, and keeping excellent heat insulation performance over a long period of time and flame retardancy, even when the styrenic resin extruded foam is foamed using a blowing agent having an ozone depleting potential of 0 (zero) and a low global warming potential.