Microparticles with Catalyst-Resin Dispersion for Organopolysiloxane Storage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
One-component curable organopolysiloxane compositions with encapsulated platinum-based catalysts face issues with storage stability and increased viscosity over time due to premature contact between the catalyst and curable component, leading to unintended curing.
Innovation Solution
Microparticles comprising a platinum-based catalyst dispersed in a thermoplastic polyolefin resin with specific molecular weight characteristics, such as a Z-average molecular weight of at least 2500 and a Mz/Mw ratio not exceeding 2.0, are used to prevent catalyst-curable component contact and maintain low viscosity during storage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the catalyst and curable component are mixed in a one-component composition, then the composition is easier to handle and store, but the catalyst and curable component come into contact during storage causing increased viscosity and premature curing
Solution Approach 1:
The platinum-based catalyst is encapsulated within microparticles having a core-shell structure where the curable component forms the core and the catalyst is dispersed in the shell. This nested structure allows both components to be present in the same composition without direct contact, resolving the contradiction between ease of storage and storage stability.
Solution Approach 2:
The microparticle structure acts as an intermediary barrier between the catalyst and curable component. The shell material serves as a mediator that prevents direct contact while allowing the components to coexist in the same composition system, enabling both ease of operation and storage stability.
2Reliability
If conventional encapsulation methods are used, then the catalyst and curable component are separated, but the storage stability deteriorates over time and viscosity increases
Solution Approach 1:
The invention changes the parameters of the encapsulation structure by controlling the molecular weight distribution (Mz/Mw ≤ 2.0) and using specific resin types (polyester, polyacrylic acid, or silicone resin) with controlled properties. This optimization of parameters maintains effective separation while improving storage stability and preventing viscosity increase over time.
Solution Approach 2:
The invention uses composite microparticles combining multiple materials: curable component (core) + catalyst-dispersing resin (shell). This composite structure provides both separation functionality and improved storage stability through the synergistic properties of the combined materials, preventing premature curing while maintaining composition stability.
3Reliability
If two-component compositions are used to separate catalyst and curable component, then storage stability is improved, but the workability deteriorates due to complex mixing requirements
Solution Approach 1:
The invention merges the catalyst and curable component into a single composition system while maintaining separation through microparticle encapsulation. This combining approach eliminates the need for separate component storage and mixing operations, improving workability while preserving storage stability through the engineered microparticle structure.
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 provides a one-component curable organopolysiloxane composition with enhanced storage stability and minimal viscosity increase over time, allowing for effective curing at low temperatures with improved handling and adhesion properties.
Implementation Method 1
a platinum-based catalyst and a thermoplastic resin, the platinum-based catalyst being dispersed in the thermoplastic resin
Implementation Method 2
the catalyst is coated or micro-encapsulated to ensure that the catalyst and the curable component do not come into contact
Implementation Method 3
in the case of a hydrosilylation reaction-curable organopolysiloxane composition, the curable component in the composition is crosslinked by a hydrosilylation reaction catalyst such as a platinum-based catalyst
Data Source
AI summary
The present invention relates to microparticles comprising: at least one type of a platinum-based catalyst; and a thermoplastic polyolefin resin with a Z-average (Mz) of a weight average molecular weight (Mw) of at least 2500 and Mz/Mw of not more than 2.0, wherein the platinum-based catalyst is dispersed in the thermoplastic polyolefin resin. The microparticles make it possible to obtain a one-component curable organopolysiloxane composition having characteristics such as excellent storage stability.