UV Curable Adhesive Thick Layer Uniform Curing
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Solution Overview
Problem
Current UV curable adhesives face limitations in producing thicker adhesive layers (above 0.2 mm) due to issues of surface over-curing and bottom layer under-curing, restricting their application scope.
Innovation Solution
A UV curable adhesive composition comprising 30-70 wt% acrylate oligomer, 20-65 wt% acrylate monomer, 1-10 wt% acryloyl morpholine, and 1-15 wt% photoinitiator, with acrylate oligomer having a weight average molecular weight of 10,000-100,000 g/mole and a glass transition temperature of -50 to 0°C, forming a loose interpenetrating network system for uniform curing and improved adhesion, cohesive force, and tackiness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If the thickness of the UV-curable adhesive layer is increased to more than 0.2 mm, then the adhesive can provide better bonding capacity and fill gaps, but the surface layer becomes over-cured and the bottom layer becomes under-cured
Solution Approach 1:
The patent changes the chemical composition parameters of the adhesive system by incorporating acryloyl morpholine monomer (1-10 wt%) and specific photoinitiators (1-15 wt%) that modify the curing characteristics. This allows the adhesive layer thickness to be increased to 0.05-1 mm while maintaining uniform curing throughout the thickness, resolving the contradiction between thickness and curing uniformity.
2Strength
If traditional pressure sensitive adhesives or foam tapes are used, then bonding strength is achieved, but material waste occurs and die cutting is required
Solution Approach 1:
The patent replaces the mechanical die cutting process with a chemical curing process. The liquid adhesive composition is dispensed in precise patterns and then cured in place through UV irradiation, eliminating the need for mechanical cutting and reducing material waste while maintaining bonding strength.
3Loss of substance
If liquid glue is printed or coated through a template to form narrow bonding solutions, then material waste is reduced and automated production is enabled, but the adhesive layer thickness is limited to less than 0.2 mm
Solution Approach 1:
The patent modifies the physical and chemical parameters of the adhesive system, specifically the molecular weight (10,000-100,000 g/mole) and glass transition temperature (-50 to 0°C) of the acrylate oligomer, along with the formulation of monomers and photoinitiators. These parameter changes enable the adhesive to be applied in thin layers (0.05-1 mm) while achieving uniform curing and maintaining bonding performance, thus allowing increased thickness without material waste.
4Strength
If the adhesive layer is made thicker to improve bonding capacity, then better adhesion and sealing properties are achieved, but the surface layer becomes over-cured and the bottom layer becomes under-cured
Solution Approach 1:
The patent changes the chemical composition parameters including the addition of acryloyl morpholine monomer (1-10 wt%) and specific photoinitiators (1-15 wt%) that modify the curing characteristics. This allows the adhesive layer thickness to be increased to 0.05-1 mm while maintaining uniform curing throughout the thickness, resolving the contradiction between thickness and curing uniformity.
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 achieves good adhesion, cohesive force, and tackiness even in thicker layers (up to 0.8 mm), ensuring uniform curing and maintaining performance across the adhesive film thickness.
Implementation Method 1
UV curable adhesive composition comprising acrylate oligomer, acrylate monomer, photoinitiator
Implementation Method 2
forming a loose interpenetrating network system for uniform curing and improved adhesion, cohesive force, and tackiness
Data Source
AI summary
The present invention provides a UV curable adhesive, wherein based on a total weight of the UV curable adhesive, the UV curable adhesive comprises: from 30 to 70 wt % of an acrylate oligomer; from 20 to 65 wt % of an acrylate monomer; from 1 to 10 wt % of acryloyl morpholine; from 1 to 15 wt % of a photo initiator; and from 0 to 10 wt % of a thickening agent, wherein the acrylate oligomer has a weight average molecular weight in a range of from 10,000 to 100,000 grams/mole and a glass transition temperature in a range of from −50 to 0° C. According to the technical solution of the present invention, the adhesive layer obtained from curing the UV curable adhesive is relatively thick (for example, 0.8 mm), and the adhesive layer has good adhesion property, cohesive force, and tackiness.