Silane-Terminated Waterproofing Coating With Lower Application Viscosity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Silane-terminated polymers used for coatings have high viscosity, making their application on substrates difficult.
Innovation Solution
A process involving a polymer mixture formed by reacting a polymer with NCO groups with a compound having exactly one NCO-reactive group, followed by contacting the resulting mixture with a silane, to control crosslink density and reduce viscosity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If silane-terminated polymers are used for waterproofing coatings, then moisture-curing capability and crosslinking performance are improved, but viscosity increases making application difficult
Solution Approach 1:
The patent applies preliminary action by pre-reacting a portion of the NCO groups with a monofunctional compound before introducing the silane. This preliminary reaction creates a controlled crosslinking framework that prevents excessive viscosity buildup during application, while still allowing subsequent moisture-curing to proceed effectively. The monofunctional compound acts as a crosslinking agent that establishes a manageable network structure in advance.
Solution Approach 2:
The patent changes the chemical parameters of the polymer system by introducing a monofunctional compound with specific NCO-reactive groups. This parameter change modifies the crosslinking density and viscosity characteristics of the formulation. By controlling the ratio of monofunctional compound to polymer and adjusting the reactivity of the NCO groups, the patent achieves optimal balance between application viscosity and final cured properties.
2Reliability
If crosslink density is increased to improve waterproofing performance, then coating durability is improved, but viscosity increases making application difficult
Solution Approach 1:
The patent uses preliminary action by pre-establishing a controlled crosslinking framework through reaction with the monofunctional compound before final curing. This creates a moderate crosslink density that maintains workability during application, while the subsequent moisture-curing process completes the crosslinking network to achieve full waterproofing performance. The staged crosslinking approach prevents viscosity issues while maintaining durability.
Solution Approach 2:
The monofunctional compound acts as an intermediary substance that mediates between the polymer chains and the silane crosslinking system. It provides a controlled intermediate crosslinking stage that regulates viscosity and enables proper application, while still allowing the final high crosslink density to develop through moisture-curing. This intermediary compound is crucial for balancing processing and 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 process results in a waterproofing coating with reduced viscosity, facilitating easier application on substrates such as roofs, terraces, balconies, wet rooms, and facades.
Implementation Method 1
which hydrolyze under the influence of moisture, condense with one another as silanol groups and thus form siloxane bonds
Implementation Method 2
condense with one another as silanol groups and thus form siloxane bonds
Implementation Method 3
crosslinking reactions of the reactive silane groups on the polymers
Data Source
AI summary
The present invention relates to a waterproofing coating formed from a composition comprising a polymer mixture, wherein said polymer mixture is obtained by a process comprising: a) contacting a polymer P1 comprising NCO groups with an average NCO-functionality of at least two with a compound C1 comprising exactly one NCO-reactive group, with a molar ratio of NCO-reactive groups of C1 to NCO groups of P1 being from 0.01 to 0.9, so as to obtain a mixture M1; and b) contacting said mixture M1 with a silane comprising at least one NCO-reactive group. It also relates to a process for waterproofing a substrate, comprising forming a waterproofing coating on the substrate using said composition.