Adhesive Composition for Vehicle Windows Resolving Sagging and Drive-Away Time

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Solution Overview

Problem

Current adhesive compositions for bonding glass in vehicles lack fast drive-away times, stability under varying environmental conditions, and compatibility with low surface energy paints, often requiring heating and primers, and face challenges with sagging and stringing, especially during window replacements.

Innovation Solution

A composition comprising isocyanate functional components, bis(glycol ether) alkylates, and catalysts, which allows for bonding without primers, maintains strength at low temperatures, and prevents sagging or stringing, using a formulation with specific weight percentages of isocyanate functional components, bis(glycol ether) alkylates, and catalysts, along with optional carbon blacks, to achieve strong and durable adhesion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If traditional plasticizers (alkyl phthalates) are used in isocyanate functional adhesives, then cost and availability are improved, but environmental safety and health concerns worsen

Engineering Contradiction:
Improvecost and availabilityVSAvoidenvironmental safety and health concerns
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The patent changes the chemical composition parameters by replacing traditional alkyl phthalate plasticizers with alternative plasticizers that have different molecular structures and properties. This substitution maintains the rheological adjustment function while eliminating the harmful environmental and health effects associated with phthalates, thus resolving the contradiction between cost/availability and environmental safety.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces alternative plasticizers that can achieve the same functional effect as traditional phthalates but without the long-term environmental persistence and health concerns. These alternatives provide a temporary, effective solution that does not accumulate harmful effects, addressing both the economic and environmental aspects of the contradiction.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

2Strength

If adhesive formulations are optimized for factory installation with robots, then bonding performance is improved, but drive-away time worsens

Engineering Contradiction:
Improvebonding performanceVSAvoiddrive-away time
Core Design Contradiction:
StrengthVSLoss of time

Solution Approach 1:

The patent creates a dynamic curing system where the adhesive formulation adapts its curing rate to match the application conditions. The catalyst system and plasticizer combination enable the adhesive to maintain optimal viscosity for robotic application while simultaneously developing sufficient strength for early removal, allowing the same formulation to optimize both bonding performance and drive-away time regardless of whether it's applied in a factory or field setting.

Inventive Principle:
Principle #15Dynamics

3Ease of operation

If adhesive viscosity is reduced for easy dispensing, then ease of application is improved, but sagging and stringing worsen

Engineering Contradiction:
Improveease of dispensingVSAvoidadhesive bead shape stability
Core Design Contradiction:
Ease of operationVSShape

Solution Approach 1:

The patent changes the rheological parameters of the adhesive by incorporating specific plasticizers that modify the viscosity-temperature relationship and shear-thinning behavior. These plasticizers enable the adhesive to have low viscosity at application temperature for easy dispensing, while maintaining higher viscosity at ambient temperature to prevent sagging and stringing, thus resolving the contradiction between ease of dispensing and bead shape stability.

Inventive Principle:
Principle #35Parameter changes

4Loss of time

If adhesive is formulated for fast curing, then drive-away time is improved, but adhesion to low surface energy paints worsens

Engineering Contradiction:
Improvedrive-away timeVSAvoidadhesion to low surface energy paints
Core Design Contradiction:
Loss of timeVSStrength

Solution Approach 1:

The patent introduces a catalyst system that acts as an intermediary to control the curing kinetics. The catalyst enables fast curing by accelerating the crosslinking reaction, while the plasticizer composition ensures proper wetting and adhesion to low surface energy paints by maintaining appropriate viscosity during the critical initial bonding phase. This intermediary control system resolves the contradiction between fast curing and adhesion performance.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 demonstrates improved adhesion to low surface energy paints, maintains strength under high temperature and humidity, and exhibits excellent shelf stability, providing fast drive-away times and reduced sagging or stringing, while being cost-effective and applicable in a primerless manner.

Implementation Method 1

c) one or more catalysts for the reaction of isocyanate moieties with hydroxyl groups

Methodology Applied
Scientific EffectCatalysis: Catalysis

Implementation Method 2

The composition may further comprise one or more isocyanate functional polyester based prepolymers which are solid at 23°C

Methodology Applied
Scientific EffectHydrolysis: Hydrolysis

Data Source

PatentEP3746495B1Adhesive useful for installing vehicle windows
Publication Date: 2022.03.09 DDP SPECIALTY ELECTRONICS MATERIALS US LLC

AI summary

Disclosed are compositions comprising: a) one or more isocyanate functional components; b) one or more one or more bis (glycol ether) alkylates; and c) one or more catalysts for the reaction of isocyanate moieties with hydroxyl groups. Disclosed is a method of bonding two or more substrates together comprising contacting two or more substrates together with a composition disclosed herein disposed along at least a portion of the area wherein the substrates are in contact. At least one of the substrates may be window glass. One of the other substrates may be a building or a vehicle.