Silicone Pressure-Sensitive Adhesive Removability After High-Temperature Exposure
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Silicone-based pressure-sensitive adhesives used in high-temperature applications tend to leave residual adhesive layers on substrates after peeling, causing issues in subsequent processing, especially in solder reflow processes on printed-circuit boards.
Innovation Solution
A silicone-based pressure-sensitive adhesive composition comprising a mixture of raw rubberlike organopolysiloxane, organopolysiloxane resin, silicon-bonded hydrogen atoms, phenol-type oxidation inhibitors, aromatic amino-type oxidation inhibitors, and a platinum-based catalyst, which forms a pressure-sensitive adhesive layer with improved removability after high-temperature exposure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If silicone-based pressure-sensitive adhesives are used to improve heat-resistant properties, then adhesive strength and electrical-insulating properties are improved, but the adhesive layer becomes difficult to remove after high-temperature exposure
Solution Approach 1:
The patent changes the chemical composition parameters of the adhesive by incorporating specific oxidation inhibitors (phenol-based and aromatic amino-based) in controlled amounts (0.01-5 wt% each), along with precise ratios of crosslinking agents and curing conditions. These parameter adjustments modify the adhesive's molecular structure to prevent excessive crosslinking at high temperatures, maintaining removability while preserving heat resistance.
Solution Approach 2:
The patent creates a composite adhesive system combining multiple components: silicone base polymer, crosslinking agents (organopolysiloxanes with silicon-bonded hydrogen), oxidation inhibitors (phenol-based and aromatic amino-based), and curing catalysts. This composite formulation synergistically provides heat resistance through crosslinking while preventing adhesive residue through the oxidation inhibitors that stabilize the polymer structure during thermal exposure.
2Strength
If cerium-containing compounds or organosilicon compounds with B—O—Si bonds are added to improve heat resistance, then adhesive strength is enhanced, but residual adhesive layer remains on substrate after peeling
Solution Approach 1:
The patent extracts or removes the problematic cerium-containing compounds and organosilicon compounds with B—O—Si bonds from the adhesive formulation. Instead, it uses alternative crosslinking mechanisms through silicon-bonded hydrogen atoms in organopolysiloxane crosslinking agents, which provide similar adhesive strength enhancement without causing residual adhesive deposition on substrates after high-temperature exposure.
Solution Approach 2:
The patent employs phenol-based and aromatic amino-based oxidation inhibitors that are consumed during the curing and heat exposure process to prevent unwanted side reactions. These inhibitors sacrificially protect the main adhesive polymers from degradation and excessive crosslinking, ensuring clean removal after use, much like disposable protective elements.
3Ease of operation
If phenol-based oxidation inhibitors are used to reduce adhesive residue, then removability is improved, but residual adhesive still remains after long-term high-temperature exposure
Solution Approach 1:
The patent merges two types of oxidation inhibitors (phenol-based and aromatic amino-based) into a single adhesive formulation. This combination provides complementary protection: phenol-based inhibitors offer immediate protection against oxidation during curing, while aromatic amino-based inhibitors provide long-term stabilization during prolonged heat exposure. The synergistic effect of both inhibitors working together maintains removability even after extended high-temperature exposure.
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 maintains good removability and cohesive strength even after exposure to high temperatures, preventing residual adhesive layers on substrates and ensuring smooth processing in applications like solder reflow processes.
Implementation Method 1
a phenol-type oxidation inhibitor and/or a phenol-modified organosiloxane, in an amount of 0.001 to 10 parts by weight per 100 parts by weight of the sum of components (A) and (B); and (D) an aromatic amino-type oxidation inhibitor and/or aromatic amino-modified organosiloxane
Implementation Method 2
a platinum-based catalyst in an amount sufficient for curing the adhesive
Implementation Method 3
an organopolysiloxane having an average of at least two silicon-bonded hydrogen atoms per molecule, wherein the silicon-bonded hydrogen atoms of this component are present in an amount of 0.5 to 150.0 moles per 1 mole of the alkenyl groups in component (A)
Data Source
AI summary
A silicone-based pressure-sensitive adhesive comprising: (A) a mixture or a product of partial condensation of (a) a raw rubberlike organopolysiloxane having an average of at least one alkenyl group per molecule and (b) an organopolysiloxane resin consisting essentially of R13SiO1/2 units and SiO4/2 units; (B) an organopolysiloxane having an average of at least two silicon-bonded hydrogen atoms per molecule; (C) a phenol-type oxidation inhibitor and/or a phenol-modified organosiloxane; (D) an aromatic amino-type oxidation inhibitor and/or aromatic amino-modified organosiloxane; and (E) a platinum-based catalyst, can form a pressure-sensitive adhesive layer that maintains good removability after being exposed to high temperatures.