Silane-Terminated Polymer Composition for UV and Storage Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Silane-terminated polymers based on polyethers have inadequate UV stability and reduced storage stability, while those based on polyesters and/or polycarbonates often have low storage stability, and isocyanate-free production leads to environmentally harmful by-products.
Innovation Solution
A composition containing at least 20% by weight of silane-terminated polymers of specific formulas (I) or (II), with a curing catalyst free of base catalysts having a pKa greater than 15, and incorporating primary, secondary, or oligomeric aminoalkoxysilanes to enhance storage and weathering stability, avoiding harmful by-products.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If silane-terminated polymers based on polyethers are used, then storage stability is reduced, but UV stability is inadequate
Solution Approach 1:
The patent changes the chemical composition parameters by incorporating specific polyester and/or polycarbonate diol monomer units with at least one side chain, ring system, or double bond into the polymer backbone. This compositional parameter change achieves both improved UV stability and maintained storage stability, resolving the contradiction between the two stability requirements.
Solution Approach 2:
The patent creates a composite polymer structure combining polyester and/or polycarbonate diol monomer units with specific structural features (side chains, ring systems, or double bonds) within the polymer backbone. This composite approach leverages the UV stability of polyester/polycarbonate while the specific structural features enhance storage stability, simultaneously addressing both requirements.
2Object-generated harmful factors
If isocyanate-free production is used, then environmentally harmful by-products are avoided, but storage stability is reduced
Solution Approach 1:
The patent changes the production method parameter to use isocyanate-free synthesis while simultaneously modifying the polymer composition to include polyester and/or polycarbonate diol monomer units with specific structural features. This dual parameter change achieves both environmental benefits (no harmful by-products) and maintains storage stability, resolving the contradiction.
3Stability of the object's composition
If polyester and/or polycarbonate diol monomer units with side chains, ring systems, or double bonds are incorporated, then storage stability is improved, but UV stability must be maintained
Solution Approach 1:
The patent optimizes the compositional parameters by incorporating polyester and/or polycarbonate diol monomer units with specific structural features (side chains, ring systems, or double bonds) at controlled proportions in the polymer backbone. This parameter optimization ensures both improved storage stability and maintained UV stability, resolving the contradiction between these two performance requirements.
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 achieves excellent storage stability and high UV stability, ensuring long-lasting and visually appealing surface coverage without environmentally harmful by-products.
Implementation Method 1
liquid, moisture-curing compositions containing a silane-terminated moisture-curing polymer
Implementation Method 2
the second component serves as crosslinker for the prepolymers
Implementation Method 3
the composition contains a curing catalyst and is free of curing catalysts or residues thereof selected from the group of base catalysts having a pKa of greater than 15
Implementation Method 4
reaction of the aforementioned polyols with di- or polyisocyanates, using the latter in excess, so that isocyanate-functional polymers are produced in this first reaction step and are then reacted in a second reaction step with alkoxysilanes having an alkyl-bonded isocyanate-reactive group
Data Source
AI summary
A surface sealant or jointing material composition contains at least 20 wt. % of a silane-terminated polymer, the polymer backbone of which is selected from a polycarbonate, a polyester, a copolymer containing a polyester and/or a polycarbonate and a polymer containing at least one ester group and/or carbonate group. This backbone contains a plurality of diol monomer at least 60% of which contain a diol of formula HO—Z—OH, wherein Z is a saturated or unsaturated hydrocarbon chain optionally containing one or more heteroatoms selected from oxygen, sulfur and a tertiary nitrogen, Z includes at least one side chain and/or at least one cyclic ring system and/or at least one double bond and the composition is free from hardening catalysts or residues thereof selected from base catalysts having a pKa value greater than 15 and from by-products that may arise by cleaving of a leaving group with silane termination of the polymer.