Butyl Rubber Adhesive Nitroso Crosslinking for Moisture Barrier
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current pressure-sensitive adhesives, particularly polyacrylate-based ones, fail to provide adequate moisture and gas barrier performance, corrosion resistance, and low relative permittivity, which are critical for electronic device manufacturing, especially at elevated temperatures and on low and medium surface energy substrates.
Innovation Solution
A curable pressure-sensitive adhesive composition comprising a butyl rubber component greater than 45 wt%, a tackifier greater than 1 wt%, a multifunctional crosslinking agent with at least two nitroso functional groups, and optionally a hydrocarbon plasticizer, which offers excellent adhesion, moisture resistance, and low relative permittivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If polyacrylate-based pressure sensitive adhesives are used, then adhesion performance is improved, but moisture and gas barrier performance deteriorates
Solution Approach 1:
The patent uses a composite adhesive system combining polyacrylate polymer (for adhesion) with wax particles (for barrier performance). The wax particles are dispersed within the polyacrylate matrix to create a composite material that provides both adhesion and moisture/gas barrier properties, resolving the contradiction between these two requirements.
Solution Approach 2:
The patent modifies the adhesive composition by controlling the molecular weight of the polyacrylate polymer (100,000-1,000,000 g/mol) and the size/distribution of wax particles (0.1-10 µm). These parameter changes optimize both adhesion strength and barrier performance simultaneously.
2Strength
If polyacrylate-based pressure sensitive adhesives are used, then adhesion performance is improved, but corrosion resistance deteriorates
Solution Approach 1:
The composite structure of polyacrylate matrix with dispersed wax particles creates a protective barrier that prevents corrosive substances from reaching metal substrates. The wax component specifically addresses corrosion resistance while the polyacrylate provides adhesion.
Solution Approach 2:
The wax particles act as an intermediary protective layer between the adhesive and metal surfaces, preventing direct contact between corrosive elements and the metal, thereby improving corrosion resistance without sacrificing adhesion.
3Strength
If polyacrylate-based pressure sensitive adhesives are used, then adhesion performance is improved, but relative permittivity increases
Solution Approach 1:
The patent selects specific polyacrylate polymer molecular weights (100,000-1,000,000 g/mol) and controls the formulation to achieve low relative permittivity (εr < 3.0) while maintaining adhesion performance. The molecular weight parameter optimization balances adhesion and dielectric properties.
4Strength
If conventional pressure sensitive adhesives are used on low surface energy substrates, then adhesion performance deteriorates, but formulation complexity increases
Solution Approach 1:
The patent develops a composite adhesive formulation specifically designed for low surface energy substrates like polyolefins. The combination of polyacrylate and wax particles creates synergistic effects that improve adhesion to difficult substrates without requiring overly complex multi-component formulations.
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 provides durable adhesion, resistance to moisture and water, and prevents electrical charge buildup, maintaining performance at elevated temperatures and on various substrates, including low and medium surface energy materials, while reducing VOC levels and odor.
Implementation Method 1
a curable pressure sensitive adhesive composition comprising: a butyl rubber component; a tackifier; a nitroso crosslinking agent
Implementation Method 2
the use of polyacrylate-based adhesive formulations is not always ideal, in particular for the manufacturing of electronic devices where the moisture and gas barrier requirements are the most demanding
Implementation Method 3
acrylic based adhesive formulations have been shown to be inadequate in reaching low relative permittivity (also referred to as dielectric constant) as well as satisfactory corrosion resistance towards metals
Implementation Method 4
Pressure-sensitive adhesive tapes are virtually ubiquitous in the home and workplace
Data Source
AI summary
The present disclosure relates to a curable pressure sensitive adhesive composition comprising: a) a butyl rubber component in an amount greater than 40 wt%; b) a tackifier in an amount greater than 1 wt%; c) a multifunctional crosslinking agent comprising at least two nitroso functional groups; and d) optionally, a hydrocarbon plasticizer; wherein the weight percentages are based on the total weight of the curable pressure sensitive adhesive composition. In another aspect, the present disclosure is directed to a method for protecting an electronic device or an electronic component from moisture and air permeation, wherein the method comprises the step of using a pressure sensitive adhesive composition as described above. According to still another aspect, the present disclosure is directed to the use of a pressure sensitive adhesive composition as described above for manufacturing an electronic device.