Polyoxyalkylene Organosilicon with Sulfide-Methylene Linkage
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Solution Overview
Problem
Existing polyoxyalkylene-containing organosilicon compounds require toxic organotin compounds as catalysts for room temperature curability and suffer from poor yellowing resistance due to urethane or urea bonds, which are not environmentally friendly.
Innovation Solution
A polyoxyalkylene-containing organosilicon compound with a sulfide-methylene bond as the linking group between the alkoxysilyl group and the polyoxyalkylene backbone, allowing for fast curability using amine compounds and eliminating the need for isocyanatosilanes, thereby enhancing yellowing resistance and safety.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If organotin compounds are used as curing catalysts to achieve room temperature curability, then curability is improved, but toxicity increases and environmental safety deteriorates
Solution Approach 1:
The patent changes the chemical structure of the linking group from conventional options to a sulfide-methylene bond (-S-CH2-), which fundamentally alters the reactivity and catalyst compatibility. This parameter change enables the use of non-toxic amine catalysts instead of organotin compounds while maintaining fast curability at room temperature
Solution Approach 2:
The patent replaces expensive and toxic organotin compounds with cheaper and non-toxic amine compounds as catalysts. The amine catalysts achieve the same curing function without the harmful side effects, making the system both safer and more economically viable
2Productivity
If isocyanatosilanes are used to achieve fast curability, then reactivity is improved, but yellowing resistance deteriorates due to urethane or urea bond formation
Solution Approach 1:
The patent extracts and eliminates the isocyanate group from the molecular structure, replacing it with a sulfide-methylene bond. This removal of the harmful isocyanate functionality prevents the formation of yellowing-prone urethane and urea bonds while retaining the desired reactivity through the alternative sulfide-methylene linkage
Solution Approach 2:
The patent changes the chemical composition by eliminating isocyanate groups and introducing sulfide-methylene bonds. This fundamental parameter change in the molecular structure eliminates the source of yellowing (urethane/urea bonds) while maintaining or improving reactivity through the new linking mechanism
3Ease of manufacture
If conventional linking groups are used in polyoxyalkylene-containing organosilicon compounds, then manufacturing is simplified, but yellowing resistance and safety deteriorate
Solution Approach 1:
The patent creates a composite molecular structure combining polyoxyalkylene backbone with alkoxysilyl end groups connected through sulfide-methylene bonds. This composite structure integrates the benefits of both components while eliminating their individual drawbacks, achieving both ease of manufacture and superior performance in yellowing resistance and safety
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 compound remains fast curable without organotin compounds, exhibits excellent yellowing resistance, and is least toxic, making it suitable for use in coating agents, adhesives, and sealants with improved mechanical properties and storage stability.
Implementation Method 1
reactive silicon groups, especially alkoxysilyl groups are susceptible to hydrolytic condensation in the presence of water
Implementation Method 2
polymers having a backbone composed of a polyoxyalkylene group and containing at both ends of the molecular chain alkoxysilyl groups capable of forming a siloxane bond for crosslinking
Data Source
AI summary
Provided is a polyoxyalkylene group-containing organosilicon compound which contains at least one group represented by structural formula (1) in one molecule and has a polyoxyalkylene structure in the main chain. This polyoxyalkylene group-containing organosilicon compound exhibits satisfactorily fast curability and excellent safety even when an amine compound is used as a curing catalyst. (In the formula, each R1 independently represents an unsubstituted or substituted C1-10 alkyl group, or an unsubstituted or substituted C6-10 aryl group, each R2 independently represents an unsubstituted or substituted C1-10 alkyl group, or an unsubstituted or substituted C6-10 aryl group, and each R3 independently represents an unsubstituted or substituted C1-10 alkyl group, or a hydrogen atom. m is a number from 1-3, and n is an integer of 2 or greater. A dashed line represents a bond.)