Moisture-Curable Adhesive Composition for Polyolefin Substrates
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Solution Overview
Problem
Conventional moisture-curable adhesives exhibit poor adhesion to polyolefin substrates due to compatibility and solubility issues between hydrolyzable-silyl-group-containing resins and chlorinated polyolefin, making it difficult to achieve a liquid state suitable for practical use as an adhesive.
Innovation Solution
A moisture-curable adhesive composition comprising a moisture-curable resin with hydrolyzable silyl groups and a modified polyolefin resin, where the modified polyolefin resin is grafted with a polyether or (meth)acrylate polymer, achieving improved compatibility and maintaining a liquid state with enhanced adhesion to polyolefin substrates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If hydrolyzable-silyl-group-containing resins are mixed with chlorinated polyolefin to improve adhesion to polyolefin substrates, then adhesion strength is improved, but compatibility and solubility deteriorate, causing gelation and viscosity increase
Solution Approach 1:
The patent introduces a compatibilizer (grafted polyolefin resin) as an intermediary substance between the hydrolyzable-silyl-group-containing resin and the chlorinated polyolefin. This compatibilizer has both polar and non-polar segments that can interact with both types of resins, improving compatibility and preventing gelation while allowing higher amounts of chlorinated polyolefin to be used for enhanced adhesion.
Solution Approach 2:
The patent creates a composite adhesive system combining hydrolyzable-silyl-group-containing resin, chlorinated polyolefin, and grafted polyolefin resin in specific proportions. This composite formulation leverages the adhesion benefits of chlorinated polyolefin while using the grafted polyolefin to maintain overall system compatibility and liquid state.
2Strength
If the amount of chlorinated polyolefin resin is increased to greatly improve adhesion, then adhesion strength is improved, but the adhesive gelates and viscosity increases, making liquid state difficult to obtain
Solution Approach 1:
The grafted polyolefin resin acts as a mediator that enables higher loading of chlorinated polyolefin (up to 40 parts or more per 100 parts of hydrolyzable-silyl-group-containing resin) while maintaining liquid state. The compatibilizer prevents excessive intermolecular interactions that would otherwise cause gelation at high chlorinated polyolefin concentrations.
Solution Approach 2:
The patent optimizes the molecular weight and grafted amount of the polyolefin resin to achieve the desired balance. By controlling these parameters, the adhesive maintains appropriate viscosity and liquid state while containing sufficient chlorinated polyolefin for strong adhesion to polyolefin substrates.
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 both excellent adhesion to polyolefin substrates and maintains a liquid state, allowing for practical use as an adhesive, with improved compatibility and dispersibility, and can be used on various substrates including metals and glass.
Implementation Method 1
undergoing crosslinking by siloxane bonds formed in the hydrolysis reaction etc. of the silyl groups that occurs due to the moisture in the air
Implementation Method 2
crosslinking by siloxane bonds formed in the hydrolysis reaction etc. of the silyl groups
Data Source
AI summary
An object of this invention is to provide an adhesive composition that comprises a moisture-curable resin and a modified polyolefin and that achieves an excellent liquid state and excellent adhesion to polyolefin resin substrates. Provided is a moisture-curable adhesive resin composition comprising a moisture-curable resin (A) and a modified polyolefin resin (B), wherein the content of the modified polyolefin resin (B) is 2 parts by mass or more per 100 parts by mass of the moisture-curable resin (A).