Oil-Resistant Optically Clear Adhesive Composition
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Optically clear adhesives (OCAs) used in electronic display applications face challenges with oil resistance, leading to mechanical and optical failures due to swelling and contamination from human skin oils and other chemicals, which affect the durability and optical clarity of devices like mobile phones and wearable devices.
Innovation Solution
An oil-resistant optically clear adhesive composition is developed, comprising hydroxy alkyl (meth)acrylate with an alkyl group containing 2 to 4 carbons, a short alkyl (meth)acrylate with an alkyl group containing 6 or less carbons, and a photo-initiator, which provides resistance to oils, maintains optical clarity, and ensures effective adhesion without edge protection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional liquid adhesive is applied to display assembly edges, then initial bonding is achieved, but the OCA swells and develops white or yellow color edges after UV curing
Solution Approach 1:
The patent modifies the chemical composition parameters of the adhesive by incorporating specific compounds (40-75 wt% polyurethane acrylates, 10-40 wt% acrylate monomers, 5-20 wt% oligomers, and 0.1-5 wt% photo-initiators) to achieve both strong bonding and oil resistance, preventing the swelling and discoloration issues of conventional adhesives
Solution Approach 2:
The patent creates a composite adhesive formulation combining multiple polymer types (polyurethane acrylates with acrylate monomers and oligomers) to achieve synergistic effects that provide both adhesion strength and resistance to oil-induced swelling, eliminating the need for edge sealing
2Illumination intensity
If OCA is used to eliminate air gaps and improve optical quality, then display brightness and contrast improve, but the OCA becomes susceptible to oil contamination from human skin
Solution Approach 1:
The patent adjusts the chemical composition parameters of the OCA by incorporating hydrophobic components and specific polymer structures that reduce affinity for oils and sebum, making the adhesive layer resistant to contamination while maintaining optical clarity and adhesion properties
Solution Approach 2:
The patent applies different functional properties to different aspects of the adhesive: the polymer matrix provides optical clarity and adhesion, while specific additives and crosslinking structures provide oil resistance, creating a multi-functional material that addresses both optical performance and contamination resistance
3Ease of manufacture
If foam tapes are used for edge sealing, then assembly is simplified, but they are ineffective at preventing chemical ingress and OCA pollution
Solution Approach 1:
The patent removes the need for separate edge sealing components (foam tapes or liquid adhesives) by integrating oil resistance directly into the OCA formulation itself, eliminating the sealing step while maintaining protection against chemical ingress and simplifying the overall assembly process
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 oil resistance, maintaining optical clarity and bond strength, preventing delamination and swelling, even after exposure to oleic acid, with minimal expansion and haze, ensuring the durability and performance of electronic devices over their lifetime.
Implementation Method 1
a photo-initiator
Data Source
AI summary
The present invention is an oil-resistant adhesive composition including a hydroxy alkyl (meth)acrylate having an alkyl group containing 2 to 4 carbons, a short alkyl (meth)acrylate having an alkyl group containing 6 or less carbons, and a photo-initiator. After the adhesive composition is soaked in oleic acid at room temperature for 7 days, the adhesive composition has an expansion percent of less than about 10%.