Silane-Modified Urethane Adhesive for Primerless Polyolefin Bonding
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Solution Overview
Problem
Existing technologies face challenges in achieving high adhesion strength between polyolefin-based resin structural materials and glass in a primerless manner, leading to variations in adhesion due to uneven surface modification.
Innovation Solution
A urethane-based adhesive composition comprising a urethane prepolymer with an isocyanate group and a polyfunctional isocyanate compound with two or more alkoxysilyl groups, obtained through a reaction of a silane compound and a polyisocyanate, which acts as an adherence agent without the need for a primer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If a polyolefin-based resin is used for structural materials, then weight reduction and moldability are improved, but adhesion difficulty increases
Solution Approach 1:
The patent introduces a silane-modified polyurethane adhesive as an intermediary substance between the polyolefin-based resin and the adherend. The silane groups in the adhesive form chemical bonds with the polyolefin surface, while the polyurethane component provides strong adhesion to the adherend, effectively mediating the bonding between materials that would otherwise be difficult to adhere
Solution Approach 2:
The patent modifies the chemical parameters of the adhesive by incorporating silane groups into the polyurethane structure. This chemical modification enables the adhesive to undergo condensation reactions with the polyolefin surface, changing the bonding mechanism from physical adhesion to chemical bonding, thereby significantly improving adhesion strength
2Strength
If surface modification treatment is applied to resin body, then adhesion is improved, but production complexity increases
Solution Approach 1:
The patent extracts and eliminates the separate surface modification treatment step from the production process. Instead of applying plasma or corona treatment to the resin surface beforehand, the silane-modified polyurethane adhesive directly bonds to the polyolefin surface through its silane groups, achieving the same adhesion enhancement without the additional production complexity
Solution Approach 2:
The silane-modified polyurethane adhesive serves multiple functions simultaneously: it acts as the bonding agent, provides chemical etching of the polyolefin surface through silane condensation, and creates a strong interface layer. This multi-functionality consolidates what would otherwise require separate surface treatment and adhesive application steps
3Reliability
If primer is applied on resin surface, then adhesion consistency is improved, but production time increases
Solution Approach 1:
The patent merges the primer function and adhesive function into a single silane-modified polyurethane adhesive composition. The adhesive contains both the bonding agents and the surface treatment agents, eliminating the need for separate primer application and reducing the process to a single adhesive application step while maintaining adhesion consistency
4Device complexity
If conventional adhesive is used without silane modification, then formulation simplicity is maintained, but adhesion to polyolefin is insufficient
Solution Approach 1:
The patent creates a composite adhesive material by combining silane groups with polyurethane structure. This composite formulation integrates the surface-bonding capability of silane groups with the adhesive properties of polyurethane, achieving strong adhesion to polyolefin while maintaining a relatively simple overall adhesive system
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 adhesive composition exhibits high adhesion strength to polyolefin-based resin surfaces in a primerless application, reducing VOC emissions, shortening production lines, and improving heat resistance and adhesion consistency.
Implementation Method 1
a polyfunctional isocyanate compound with two or more alkoxysilyl groups, which is obtained through a reaction of a silane compound having two or more alkoxysilyl groups in one molecule and a polyisocyanate
Implementation Method 2
a urethane prepolymer having an isocyanate group at one end; and a polyfunctional isocyanate compound... wherein the polyfunctional isocyanate compound is obtained through a reaction of a silane compound and a polyisocyanate
Data Source
AI summary
The present invention provides an adhesive composition which is a primerless urethane-based adhesive and has high adhesive force with respect to a polyolefin-based resin. An adhesive composition according to the present invention is a two-liquid type urethane-based adhesive composition comprising: a main agent which comprises (A) a urethane prepolymer having an isocyanate group at the end thereof, (B) a polyfunctional isocyanate compound having an alkoxysilyl group which can be obtained through a reaction of a silane compound having at least two alkoxysilyl groups in one molecule and a polyisocyanate having an isocyanate group at the end thereof and (C1) a first curing catalyst; and a curing agent which comprises (D) a hydrophobic polyol and (C2) a second curing catalyst.