Polyurethane Binder System for Lightweight Construction Adhesion

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Solution Overview

Problem

In industries like vehicle manufacturing, where lightweight construction is prevalent, there is a need for adhesives that provide both high tensile strength and flexibility to effectively bond diverse materials at room or elevated temperatures, as existing adhesives often fail to meet these dual requirements.

Innovation Solution

A binder system comprising a resin component with a special polyol mixture, including at least 10% by weight of polyester polyols based on fatty acid dimers or trimers, and a hardener component featuring polyisocyanate and/or NCO-terminated polyurethane prepolymer, with specific molecular weight ranges and ratios, is used to create a two-component adhesive for efficient bonding of substrates like wood, plastic, or metal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If conventional adhesives are used to bond lightweight construction materials, then bonding can be achieved, but the adhesive cannot simultaneously provide both high tensile strength and high flexibility

Engineering Contradiction:
Improvetensile strengthVSAvoidflexibility
Core Design Contradiction:
StrengthVSAdaptability or versatility

Solution Approach 1:

The adhesive uses a composite polyol system combining polyester polyols (for strength) and polyether polyols (for flexibility), creating a material that simultaneously achieves high tensile strength and high elongation to accommodate different substrate properties in lightweight construction

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The invention adjusts the molecular weight and composition parameters of the polyol mixture, specifically using polyester polyols with Mw 1000-4000 g/mol and polyether polyols with Mw 2000-10000 g/mol, to optimize the balance between strength and flexibility

Inventive Principle:
Principle #35Parameter changes

2Strength

If adhesives provide high tensile strength, then bonding strength is improved, but flexibility and elongation are reduced

Engineering Contradiction:
Improvebonding strengthVSAvoidelongation
Core Design Contradiction:
StrengthVSStability of the object's composition

Solution Approach 1:

The adhesive employs a composite polyol system where polyester polyols (10-70 wt%) contribute to bonding strength while polyether polyols (30-90 wt%) provide elongation and flexibility, achieving both high strength and high stability

Inventive Principle:
Principle #40Composite materials

3Ease of manufacture

If a single polyol type is used in the adhesive, then formulation is simplified, but performance in bonding diverse lightweight materials is insufficient

Engineering Contradiction:
Improveformulation simplicityVSAvoidbonding performance
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The adhesive formulation uses a multi-functional polyol blend where polyester polyols provide strength for rigid bonds and polyether polyols provide flexibility for accommodating thermal expansion and contraction, enabling universal bonding performance across diverse lightweight construction materials

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 binder system achieves high tensile strengths and elongations, enabling efficient bonding of various substrates with mechanical properties exceeding 7 MPa tensile strength and over 80% elongation, making it suitable for lightweight construction applications.

Implementation Method 1

a binder system comprising (i) a resin component comprising (a) at least 10 wt% based on the total weight of the resin component of a polyester polyol based on a fatty acid dimer or trimer or the diols or triols derived therefrom... (ii) a hardener component comprising at least one polyisocyanate, preferably an aromatic diisocyanate, and/or at least one NCO-terminated polyurethane prepolymer

Methodology Applied
Scientific EffectPolymerization:

Data Source

PatentEP3625279B1Polyurethane-based binder system
Publication Date: 2024.08.07 HENKEL KGAA

AI summary

The present invention relates to a binder system, containing a special polyol mixture as a resin component, said polyol mixture containing at least one polyester based on a fatty acid dimer, a fatty acid trimer or the alcohols derived therefrom, and at least one polyisocyanate as a resin component and/or a NCO-terminated polyurethane prepolymer. The invention also relates to the use of the binder system as an adhesive/sealing material, in particular as an adhesive for gluing various substrates.