Moisture-Curable Silylated Polymer Adhesion to Unprimed Concrete
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Solution Overview
Problem
Conventional hydrolysable silane-terminated polymers exhibit poor wet soak adhesion to unprimed concrete substrates, particularly when immersed in water for seven days or longer, leading to adhesive mode failure and low peel strength.
Innovation Solution
A moisture-curable resin composition comprising a moisture-curable polymer with hydrolysable silyl groups, hydrocarbylalkoxysilane, and a silane adhesion promoter with a glycidoxy group, optimized in weight percentages to enhance adhesion and cohesion on unprimed concrete substrates, while being free from hydroxyl-terminated dimethyl siloxane and low molecular weight glycols.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional hydrolysable silane-terminated polymers are used, then environmental durability and adhesion to glass, aluminum and plastics are improved, but wet soak adhesion to unprimed concrete deteriorates after immersion in water
Solution Approach 1:
The patent combines hydrolysable silane-terminated polymers with polysiloxane oil emulsion and silane adhesion promoters to create a composite resin composition. This composite formulation integrates the environmental durability of silane-terminated polymers with the concrete adhesion enhancement from polysiloxane and silane additives, resolving the contradiction between general adhesion performance and specific wet soak adhesion to concrete.
Solution Approach 2:
The patent modifies the chemical composition parameters by incorporating specific ratios of polysiloxane oil emulsion (5-50 wt%) and silane adhesion promoters (1-20 wt%) into the resin system. These parameter changes transform the formulation from conventional silane-terminated polymer alone to an optimized composite system that maintains hydrolytic stability while achieving superior wet soak adhesion to unprimed concrete substrates.
2Strength
If efforts are made to improve adhesion to unprimed concrete using epoxy-functional silicone fluid or polysiloxane oil emulsion, then some adhesion improvement is achieved, but peel strength and cohesive failure mode deteriorate when immersed in water
Solution Approach 1:
The patent introduces silane adhesion promoters as intermediary substances that bridge the polymer matrix and concrete substrate. These silane promoters contain both hydrolyzable alkoxy groups for bonding to concrete and organic functional groups for compatibility with the polymer matrix, creating a reliable intermediate bonding layer that maintains peel strength and cohesive failure mode even after water immersion.
Solution Approach 2:
The patent applies different functional components at different levels: hydrolysable silane-terminated polymers provide the base polymer matrix with environmental durability, polysiloxane oil emulsion provides concrete surface compatibility and penetration, and silane adhesion promoters provide localized bonding sites at the substrate interface. This local quality differentiation ensures both adhesion improvement and maintenance of peel strength after water immersion.
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 high peel strengths and cohesive failure modes on unprimed concrete even after immersion in water for seven days, providing improved adhesion and durability.
Implementation Method 1
hydrolysable silane-terminated polymers
Implementation Method 2
Hydrolysable silane-terminated polymers and their use in sealants, adhesives and coatings
Data Source
AI summary
A moisture-curable resin composition comprising (a) at least one moisture-curable polymer having at least one hydrolysable silyl group; (b) at least one hydrocarbylalkoxysilane; and (c) at least one silane adhesion promoter containing a glycidoxy group. The composition may also contain additives including a catalyst for catalyzing the reaction between the moisture-curable polymer having at least one hydrolysable silyl group (a) with water under curing conditions, a filler, a plasticizer, and combinations thereof. The moisture-curable resin composition is useful in the production of adhesives, sealants and coatings for use in primerless concrete applications.