Curable Composition for Moisture-Permeable Waterproofing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing liquid-applied waterproofing materials with polyoxyalkylene polymers having reactive silicon groups exhibit insufficient moisture permeability while maintaining waterproofing properties, which is a concern for building durability and indoor air quality, especially around openings and on exterior walls.
Innovation Solution
A curable composition comprising a polyoxyalkylene plasticizer with specific structural features, such as the absence of an -NH2 group and the presence of -OH groups at molecular chain ends, is used to enhance the water vapor permeability of the cured product, allowing for improved moisture permeability while maintaining waterproofing properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a liquid-applied waterproofing material containing latex polymer (aqueous emulsion) is used, then the coating can be applied, but it requires a long period of time to form a continuous layer at low temperature or high humidity conditions
Solution Approach 1:
The patent changes the chemical composition parameters of the waterproofing material by using polyoxyalkylene polymer with reactive silicon groups instead of latex polymer, and by controlling the plasticizer content (5-50 parts by weight per 100 parts polymer), enabling the coating to cure properly at low temperatures and high humidity without requiring extended drying times
2Strength
If a liquid-applied waterproofing material containing latex polymer is used, then the coating can be applied, but the coating is poor in elasticity and cannot resist prolonged strain of substrate
Solution Approach 1:
The patent changes the polymer type from latex to polyoxyalkylene polymer with reactive silicon groups, which inherently provides better elasticity. The patent also optimizes the plasticizer content (5-50 parts by weight per 100 parts polymer) to achieve the right balance between flexibility and structural integrity, preventing cracks and breaks under prolonged strain
Solution Approach 2:
The patent creates a composite system by combining polyoxyalkylene polymer with reactive silicon groups and specific plasticizers, where the plasticizer enhances the elasticity and flexibility of the polymer matrix, enabling the coating to resist prolonged substrate strain without developing cracks or breaks
3Reliability
If common waterproofing sheets with moisture vapor proofness are used, then waterproofing property is achieved, but moisture cannot be drained through the sheet
Solution Approach 1:
The liquid-applied coating forms a continuous membrane that maintains waterproofing while allowing moisture vapor transmission, preventing moisture accumulation on the substrate while still blocking liquid water penetration
Solution Approach 2:
The combination of polyoxyalkylene polymer with reactive silicon groups and plasticizers creates a material that achieves both waterproofing and moisture permeability, resolving the contradiction between blocking liquid water and allowing vapor transmission
4Reliability
If pressure sensitive adhesive tape with rubber or asphalt materials is used to finish openings, then waterproofing around openings is achieved, but the moisture permeability of the entire tape decreases
Solution Approach 1:
The patent changes the material composition by using polyoxyalkylene polymer with reactive silicon groups and specific plasticizers in the liquid-applied coating, which cures to form a membrane that maintains both waterproofing and moisture permeability, unlike traditional rubber or asphalt tapes
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 significantly improves energy efficiency and durability of buildings by enhancing moisture permeability, reducing the risk of mold growth and improving indoor air quality, while maintaining the integrity of the waterproofing layer.
Implementation Method 1
Such an organic polymer can crosslink even at a room temperature by forming siloxane bond through hydrolysis of the reactive silicon group under an existence of moisture in the air.
Data Source
AI summary
The present invention has its object to provide a liquid-applied moisture-permeable waterproofing material that can protect a building from rainwater or humidity in the air, can drain moisture, which has been gathered on a substrate of a building, and can be applied easily. The present invention is a curable composition comprising: (A) a polyoxyalkylene polymer having a silicon-containing group crosslinkable by forming a siloxane bond; (B) a polyoxyalkylene plasticizer whose main chain contains 5 wt% or more of an oxypropylene-derived repeating unit and has one or more groups, at an end thereof, selected from the group consisting of an -OH group, a group represented by the formula: -OR9 (wherein R9 is a substituted or unsubstituted C1-20 hydrocarbon group), and a group represented by the formula: -NR10 2 (wherein R10 is each independently a hydrogen atom, or a substituted or unsubstituted C1-20 hydrocarbon group).