Moisture-Curing Composition Silicate Foaming Suppression
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Solution Overview
Problem
Moisture-curing compositions face challenges in maintaining physical properties like hardness, tensile strength, and oil resistance over time, particularly under harsh conditions, and tend to experience foaming issues that lead to cracking or fracture during durability tests at high temperatures.
Innovation Solution
A moisture-curing composition comprising an oligomer with hydrolyzable silyl groups, polydialkylsiloxane, silicate, and a curing catalyst, where the silicate is used in specific amounts to suppress foaming and maintain stable physical properties, including heat and oil resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a vinyl-based polymer with hydrolyzable silyl groups is used as a moisture-curing composition, then the composition can cure upon exposure to air without energy input, but foaming occurs during durability tests at high temperatures leading to cracking or fracture
Solution Approach 1:
The patent changes the chemical composition parameters by introducing silicate (0.1-5.0 parts by mass relative to 100 parts of vinyl-based polymer) and controlling the silyl group content (1-20 mmol/g) to suppress foaming while maintaining curing functionality. This parameter optimization resolves the contradiction between easy curing and durability.
Solution Approach 2:
The patent creates a composite moisture-curing composition combining vinyl-based polymer, silicate, and curing catalyst. This composite structure suppresses foaming during high-temperature durability tests while maintaining the ability to cure upon air exposure, thereby improving reliability without sacrificing ease of manufacture.
2Ease of operation
If cross-linkable dimethylpolysiloxane is added to a vinyl-based polymer to improve surface curability, then surface tack is lowered, but the physical properties like hardness and tensile strength deteriorate over time
Solution Approach 1:
The patent optimizes the concentration of cross-linkable silyl groups (1-20 mmol/g) and adds silicate (0.1-5.0 parts by mass) to control the cross-linking density. This parameter control maintains surface curability while preventing excessive cross-linking that would deteriorate physical properties over time.
Solution Approach 2:
The silicate acts as an intermediary substance that mediates between the vinyl-based polymer and the curing process. It suppresses foaming and stabilizes the cured product's physical properties while allowing the vinyl-based polymer to maintain its surface curability characteristics.
3Reliability
If the composition is used in harsh environmental conditions requiring heat resistance and oil resistance, then the composition must maintain stable physical properties, but foaming occurs during durability tests causing cracking or fracture
Solution Approach 1:
The patent modifies the composition parameters by adding silicate (0.1-5.0 parts by mass) and controlling silyl group content (1-20 mmol/g) to suppress foaming during high-temperature durability tests. This enables the composition to maintain heat resistance and oil resistance without suffering from foaming-induced cracking or fracture.
Solution Approach 2:
The patent converts the potentially harmful effect of alcohol accumulation from cross-linkable silyl groups into a beneficial outcome by using silicate to suppress foaming. This allows the composition to undergo durability tests at high temperatures without developing cracks or fractures, thereby achieving both heat resistance and oil resistance.
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 composition effectively suppresses foaming and maintains stable physical properties, such as hardness and tensile strength, even after durability tests, ensuring reliable performance in harsh environments.
Implementation Method 1
a silicone composition forms a siloxane bond which is caused by moisture in the air. By containing a silicon atom with a hydrolyzable functional group
Data Source
AI summary
Regarding a durability test of a moisture-curing composition, it is difficult to both suppress foaming in the inside of a cured product and to stably maintain the physical properties of a cured product.A moisture-curing composition containing the components (A) to (D), the moisture-curing composition containing 0.5 to 5.0 parts by mass of the component (C) relative to 100 parts by mass of the component (A):Component (A): an oligomer which has a polymer of (meth)acrylic monomers as a main chain and which has a hydrolyzable silyl group in the moleculeComponent (B): specific polydialkylsiloxaneComponent (C): silicateComponent (D): a curing catalyst.