Polyurethane Grout Composition for High Water Pressure Seepage Control

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Solution Overview

Problem

Polyurethane grout materials fail to effectively cure and provide adequate mechanical properties and adhesion under high water pressure environments, which is crucial for applications like core drilling exploration and underground tunnel joints.

Innovation Solution

A polyurethane grout composition comprising an isocyanate prepolymer and auxiliary components such as a silane coupling agent, catalyst, and blowing agent, which reacts with a polyfunctional polyol containing ethylene oxide units and a monofunctional hydroxyl compound, allowing for fast curing and improved bonding strength and impact resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If polyurethane grout materials are used under high water pressure environment, then water leakage control is needed, but the materials fail to cure effectively and provide adequate mechanical properties and adhesion

Engineering Contradiction:
Improvecuring effectiveness and mechanical propertiesVSAvoidwater pressure
Core Design Contradiction:
ReliabilityVSStress or pressure

Solution Approach 1:

The patent modifies the chemical composition parameters of the polyurethane grout by incorporating specific ratios of hydrophilic and hydrophobic polyols, silane coupling agents, and catalysts. This compositional parameter change enables the material to cure effectively under high water pressure conditions (up to 20 MPa) while maintaining adequate mechanical properties and adhesion, directly resolving the contradiction between curing effectiveness and water pressure resistance

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention creates a composite grout system combining hydrophilic polyol components (for water reactivity and curing), hydrophobic polyol components (for mechanical properties and water resistance), silane coupling agents (for adhesion enhancement), and catalysts. This composite material approach allows the grout to simultaneously achieve effective curing, mechanical strength, and adhesion under high water pressure environments

Inventive Principle:
Principle #40Composite materials

2Speed

If hydrophilic polyurethane grout is used, then reactivity with water is improved, but mechanical properties and adhesion deteriorate under high water pressure

Engineering Contradiction:
Improvereactivity with waterVSAvoidmechanical properties and adhesion
Core Design Contradiction:
SpeedVSStrength

Solution Approach 1:

The patent merges hydrophilic polyol components (providing rapid water reactivity) with hydrophobic polyol components (providing mechanical strength and adhesion). The specific formulation combines these contrasting components in optimized ratios, allowing the grout to simultaneously achieve fast curing through hydrophilic components while maintaining superior mechanical properties through hydrophobic components, thus resolving the contradiction between reactivity and strength

Inventive Principle:
Principle #5Merging (Combining)

3Strength

If hydrophobic polyurethane grout is used, then mechanical properties are improved, but curing under water pressure above 1 MPa fails

Engineering Contradiction:
Improvemechanical propertiesVSAvoidcuring capability under water pressure
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent introduces silane coupling agents as intermediary components that bridge the hydrophobic polyol matrix with water. These silane agents provide hydrolyzable groups that react with water to initiate curing of the otherwise hydrophobic system, enabling the grout to cure effectively under water pressure while maintaining the mechanical properties provided by the hydrophobic polyol base

Inventive Principle:
Principle #24Intermediary (Mediator)

4Productivity

If fast curing is achieved under high water pressure, then water leakage stoppage is quick, but formulation complexity increases

Engineering Contradiction:
Improvecuring speed and leakage stoppage efficiencyVSAvoidformulation complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent employs catalysts that automatically activate and accelerate the curing reaction under water pressure conditions without requiring external intervention. The silane coupling agents self-hydrolyze upon contact with water, and the catalyst system autonomously promotes polymerization, enabling fast curing (within 30 minutes under 20 MPa) while simplifying the overall formulation approach through self-activating mechanisms rather than complex multi-step processes

Inventive Principle:
Principle #25Self-service

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 quick stoppage of water leakage and provides durable sealing with excellent mechanical properties and adhesion under high water pressure, effectively addressing the limitations of prior art by curing into a solid within 30 minutes under pressures up to 20 MPa.

Implementation Method 1

polyurethane grout materials can react with the in-situ water to form a foam or gel

Methodology Applied
Scientific EffectChemical reaction (isocyanate-water reaction): Chemical Bonding

Implementation Method 2

react with the in-situ water to form a foam or gel

Methodology Applied
Scientific EffectFoam formation: Foam

Implementation Method 3

auxiliary components selected from a plasticizer, a silane coupling agent, a catalyst

Methodology Applied
Scientific EffectAdhesion: Adhesive

Data Source

PatentEP2855550B1Polyurethane grout compositions
Publication Date: 2024.06.19 HUNTSMAN INTERNATIONAL LLC
  • EP2855550B1 patent drawingFigure 1A~2

AI summary

The present invention typically provides one-component polyurethane grout compositions and more specially to grout composition useful for seepage control and quick stoppage of water leakage under high water pressure environment, wherein the composition comprises a isocyanate prepolymer and auxiliary components selected from a plasticizer, a silane coupling agent, a catalyst, a cell stabilizer, an anionic surfactant, a filler, a blowing agent or a mixture thereof. The invention also provides the isocyanate prepolymer composition, obtained by reacting a polyfunctional isocyanate, with a polyfunctional polyol comprising at least one polyether polyol containing relatively low amount of ethylene oxide units, and optionally other polyfunctional polyols such as polyester polyols, biorenewable polyols or a mixture thereof, and at least a monofunctional hydroxyl containing compound, wherein the NCO content of said prepolymer is 3%~ 18%. The resulting grout composition can cure into a solid under water pressure from 1 MPa to 20 MPa.