Silicone Adhesive Composition for Solvent-Free Pressure-Sensitive Coating
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Solution Overview
Problem
Existing polysiloxane pressure-sensitive adhesives are limited by mechanical strength and elongation, especially in solvent-free forms, and require organic solvents for application, which is environmentally undesirable.
Innovation Solution
A silicone adhesive composition comprising specific organopolysiloxanes and a hydrosilylation catalyst, allowing for solvent-free application with excellent curability, mechanical strength, and elongation, forming a pressure-sensitive adhesive layer with sufficient adhesive force.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If solvent-free polysiloxane pressure-sensitive adhesive is used, then environmental compatibility is improved, but mechanical strength and elongation deteriorate
Solution Approach 1:
The invention changes the chemical composition parameters by introducing specific crosslinking agents (organohydrogenpolysiloxane with SiH groups) and catalysts into the solvent-free adhesive system. This enables chemical crosslinking reactions that fundamentally alter the physical properties of the adhesive, achieving both high mechanical strength and elongation while maintaining environmental compatibility through solvent-free formulation
Solution Approach 2:
The invention creates a composite adhesive system combining polysiloxane base resin, crosslinking agents, and catalysts in a solvent-free matrix. This composite structure enables simultaneous achievement of environmental friendliness, mechanical strength, and flexibility through the synergistic interaction of multiple functional components
2Ease of manufacture
If organic solvents are used for application, then coating processability is improved, but environmental compatibility deteriorates
Solution Approach 1:
The invention extracts and removes organic solvents from the adhesive formulation entirely, creating a solvent-free system. By eliminating the harmful solvent component while retaining coating processability through controlled viscosity and appropriate application methods, the invention achieves environmental compatibility without sacrificing ease of manufacture
Solution Approach 2:
The invention changes the physical parameters of the adhesive system by adjusting molecular weight, viscosity, and composition ratios to enable direct coating without solvents. This allows the adhesive to be applied in a solvent-free state while maintaining proper flow and adhesion characteristics
3Temperature
If polysiloxane pressure-sensitive adhesive is used, then heat resistance and electrical insulating properties are improved, but adhesion to various adherends deteriorates
Solution Approach 1:
The invention applies local quality modification by introducing specific functional groups and crosslinking structures at strategic locations in the adhesive molecule. The crosslinking agents and catalysts create localized regions of enhanced bonding capability that improve adhesion to various adherends while preserving the overall heat resistance and electrical insulating properties of the polysiloxane matrix
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 enables coating with minimal solvent use, achieving high adhesive strength and flexibility, suitable for electronic devices, with improved production and performance of electronic parts.
Implementation Method 1
a curing-reactive organopolysiloxane composition... (B) a straight-chain organohydrogenpolysiloxane having silicon-bonded hydrogen atoms... (E) a hydrosilylation reaction catalyst; where: the ratio of the number of moles of silicon-bonded hydrogen atoms in component (B) to the number of moles of aliphatic unsaturated carbon-carbon bond-containing groups in components (A) to (D)
Data Source
AI summary
To provide a silicone adhesive composition and an application thereof, that has a viscosity that enables coating even with a small amount of solvent content, has excellent curability due to hydrosilylation reaction, cures, has sufficient adhesive strength for practical use, and has excellent mechanical strength and elongation of the adhesive layer after curing, and can form a pressure-sensitive adhesive layer having sufficient adhesive strength for practical use. A silicone adhesive composition, containing: (A) a chain-like organopolysiloxane having at least two aliphatic unsaturated carbon-carbon bond-containing groups only at the terminals of the molecular chain; (B) a straight-chain organohydrogenpolysiloxane having silicon-bonded hydrogen atoms only at both terminals of the molecular chain; (C) a resinous organopolysiloxane; and (D) an organopolysiloxane having at least one or more aliphatic unsaturated carbon-carbon bond-containing groups at locations other than the ends of the molecular chain, and having at least three or more aliphatic unsaturated carbon-carbon bond groups in the molecule; where the ratio of the number of moles of silicon-bonded hydrogen atoms in component (B) to the number of moles of aliphatic unsaturated carbon-carbon bond-containing groups in components (A) to (D) is in the range of 0.70 to 1.30, and the amount of substance of the aliphatic unsaturated carbon-carbon bond-containing groups in component (D) is in the range of 0.001 to 0.030 in 100 g of the total amount of components (A) to (D) in the composition.