Foamable Silane-Modified Polymer Sealing for Isocyanate-Free Joints
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Solution Overview
Problem
Existing sealing technologies, such as stamped elastomers and fitted rubber profiles, are costly, time-consuming, and generate waste, while conventional foam-in-place-gasketing materials rely on harmful isocyanates and propellants, making them unsuitable for efficient and safe sealing applications, especially in industries with large joints and temperature fluctuations.
Innovation Solution
A two-component foamable silane-modified polymer composition using alkali metal bicarbonates or carbonates and an organic acid, which expands to form a silane-modified polymer foam with excellent adhesion and impermeability, avoiding isocyanates and harmful propellants, suitable for in-situ sealing and sound damping.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional foam-in-place-gasketing materials using isocyanates and propellants are used, then foaming and sealing capability is achieved, but harmful substances are introduced and safety concerns arise
Solution Approach 1:
The patent replaces harmful isocyanates and fluorinated propellants with benign alternatives: water and food-grade organic acids (like citric acid, lactic acid, or acetic acid) generate CO2 for foaming, while natural blowing agents replace harmful propellants. This converts a potentially harmful chemical system into a safe, environmentally friendly one while maintaining sealing performance.
Solution Approach 2:
The patent fundamentally changes the chemical parameters of the foaming system by eliminating isocyanates and fluorocarbons, using instead water-based or food-grade acid-based systems that decompose into harmless substances (CO2, water, organic salts), thereby maintaining functionality while removing harmful factors.
2Reliability
If stamped elastomers and fitted rubber profiles are used for sealing, then sealing performance is achieved, but production cost increases and waste is generated
Solution Approach 1:
The foamable composition applies itself automatically to the joint space and expands to fill it completely, eliminating the need for manual cutting, fitting, and installation of pre-formed seals. The material self-adjusts to the exact dimensions of the joint, preventing waste and reducing labor.
Solution Approach 2:
The patent changes the physical state and application method from pre-formed solid profiles requiring mechanical installation to a pumpable liquid composition that expands in-situ, eliminating material waste from cutting and fitting operations while maintaining sealing effectiveness.
3Reliability
If pre-profiled permanently plastic sealants are used, then sealing is formed, but production time increases due to manual insertion and gluing
Solution Approach 1:
The foamable composition is pumped directly into the joint space where it automatically expands and cures in-situ, eliminating all manual operations including insertion, positioning, and gluing. The material self-forms the seal profile and self-cures, dramatically reducing production time and labor requirements.
Solution Approach 2:
The patent extracts and eliminates the manual labor steps (insertion, positioning, gluing) from the sealing process by using a pumpable composition that automatically fills and cures in the joint space, leaving only the essential pumping and curing steps.
4Reliability
If conventional foamable sealants are used for large cross-section joints, then sealing coverage is achieved, but thermal expansion fluctuations cause tightness issues
Solution Approach 1:
The patent changes the chemical composition to include silane-modified polymers that cure into elastomeric foams with stable dimensional properties. The silane modification provides crosslinking that maintains structural integrity and dimensional stability during thermal cycles, preventing tightness issues while maintaining sealing coverage in large joints.
Data Source
AI summary
The invention relates to a two-component foamable silane-modified polymer composition comprising: a component A comprising (a-1) at least one silane modified polymer, and (a-2) at least one chemical blowing agent selected from the group consisting of alkali metal bicarbonate, alkali metal carbonate, ammonium bicarbonate and ammonium carbonate, and a component B comprising (b-1) water, and (b-2) at least one an organic acid; wherein component A and/or component B comprises at least one surface treated calcium carbonate; the invention also relates to a method for preparing a silane-modified polymer foam attached to a part of assembly in situ and to a silane-modified polymer foam obtained by the method, as well as a gasket, sealant or adhesive comprising a two-component foamable silane-modified polymer composition or said silane-modified polymer foam.