Thermosetting In-Mold Coating Composition for Stable Polyolefin Adhesion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing thermosetting coating compositions for in-mold coating of polyolefin substrates suffer from poor compatibility and long-term storage stability, leading to inadequate adhesive properties and insufficient adhesion to polyolefin materials.
Innovation Solution
A thermosetting coating composition comprising urethane (meth)acrylate with 2-4 polymerizable unsaturated groups and an aliphatic structure, combined with a polymerizable unsaturated compound having a boiling point higher than the curing temperature and a permeation rate of 1% or more, and a polymerization initiator, to enhance adhesion and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If acrylic modified polyolefin or chlorinated polyolefin is blended with in-mold coating composition to ensure adhesive property to polyolefin substrate, then adhesive property is improved, but compatibility between polyolefin component and other resin components deteriorates, resulting in poor long-term storage stability
Solution Approach 1:
The invention extracts and eliminates the problematic polyolefin components (acrylic modified polyolefin or chlorinated polyolefin) from the coating composition while maintaining adhesion to polyolefin substrates. This is achieved by using a completely different chemical approach based on silane-modified polyester resin that does not rely on polyolefin blending, thus resolving the contradiction between adhesion and storage stability
Solution Approach 2:
The invention changes the chemical parameters of the coating composition by using silane-modified polyester resin as the base resin instead of conventional polyolefin-based systems. This fundamental parameter change allows the coating to achieve adhesion to polyolefin substrates through silane coupling mechanisms rather than polyolefin compatibility, thereby eliminating the storage stability issues
2Ease of manufacture
If conventional thermosetting coating composition is used for in-mold coating of polyolefin substrate, then coating process is simple, but adhesive property is insufficient
Solution Approach 1:
The invention changes the chemical composition parameters by using silane-modified polyester resin with specific functional groups that provide excellent adhesion to polyolefin substrates. The silane modification introduces reactive sites that bond effectively with polyolefin surfaces, achieving superior adhesive properties while maintaining the simplicity of the in-mold coating process
Solution Approach 2:
The invention uses silane-modified polyester resin as a composite material that combines the benefits of polyester resin (good flow and curing characteristics) with silane coupling agents (excellent adhesion to polyolefin). This composite approach maintains process simplicity while dramatically improving adhesive property
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 forms a coating film with excellent adhesive properties to various plastic materials, ensuring long-term stability and improved adhesion, particularly to polyolefin substrates, while maintaining flexibility and weather resistance.
Implementation Method 1
a permeation rate with respect to the plastic material of 1 mass % or more
Implementation Method 2
an initiator capable of generating free radicals
Data Source
AI summary
The purpose of the present invention is to provide a coating material composition that is suitable for in-mold coating applications, and is capable of forming a coating film particularly having excellent adhesion properties to materials. This thermosetting coating material composition is for a plastic material and contains a urethane (meth)acrylate (A) having 2-4 polymerizable unsaturated groups and an aliphatic structure, a polymerizable unsaturated compound (B) having one polymerizable unsaturated group per molecule, and a polymerization initiator (C), and is characterized in that the polymerizable unsaturated compound (B) contains a polymerizable unsaturated compound (b1) that (i) has a boiling point equal to or higher than the curing temperature thereof, (ii) has a rate of permeation with respect to a plastic material of at least 1 mass %, and (iii) has a coating liquid turbidity of at most 50 degrees when mixed with the urethane (meth)acrylate (A).