Acrylic-Silicone Graft Copolymer Release Additive for Adhesion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing release sheet compositions with phenyl group-containing diorganopolysiloxanes exhibit low subsequent adhesion ratios due to non-reactive components, and compositions with reactive groups like alkenyl or hydroxyl groups are costly and do not provide sufficient release force for strongly adhesive materials.
Innovation Solution
An organopolysiloxane composition with an acrylic-silicone graft copolymer, having a weight-average molecular weight of 1,000 to 100,000, is used, which includes an alkenyl group-containing organopolysiloxane, organohydrogenpolysiloxane, and a platinum group metal catalyst, forming a cured coating that provides a low release force and high subsequent adhesion ratio.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If phenyl group-containing diorganopolysiloxane is used as release additive, then easy release properties are improved, but subsequent adhesion ratio deteriorates due to non-reactive components adhering to strongly adhesive materials
Solution Approach 1:
The invention changes the chemical reactivity parameter of the release additive by using organopolysiloxane with reactive groups (alkenyl, SiH, or hydroxyl groups) instead of non-reactive phenyl group-containing diorganopolysiloxane. This allows the additive to participate in crosslinking reactions and become fixed in the cured coating, preventing it from adhering to the pressure-sensitive adhesive material while maintaining easy release properties.
Solution Approach 2:
The invention creates a composite system by combining reactive organopolysiloxane with phenyl groups (for easy release) and reactive groups (for crosslinking), along with an organohydrogenpolysiloxane crosslinking agent. This composite approach allows simultaneous achievement of easy release properties and high subsequent adhesion ratio through chemical crosslinking that fixes the release additive in place.
2Reliability
If organopolysiloxane with reactive groups (alkenyl, SiH, or hydroxyl groups) is used to achieve high subsequent adhesion ratio, then non-reactive ingredient problem is solved, but release force becomes insufficient for strongly adhesive materials
Solution Approach 1:
The invention applies local quality by incorporating phenyl groups specifically into the organopolysiloxane structure to provide easy release properties at the interface with the pressure-sensitive adhesive material, while simultaneously incorporating reactive groups (alkenyl, SiH, or hydroxyl groups) that participate in crosslinking to ensure high subsequent adhesion ratio. This localized functional differentiation resolves the contradiction between sufficient release force and high adhesion ratio.
3Force
If large amount of alkenyl group-containing branched organopolysiloxane is used to achieve desired release properties, then release force is sufficient, but production cost increases
Solution Approach 1:
The invention uses organohydrogenpolysiloxane as a crosslinking agent (intermediary) that reacts with the reactive groups (alkenyl, SiH, or hydroxyl groups) of the organopolysiloxane containing release additive. This crosslinking mechanism allows the release additive to be fixed in the cured coating at lower concentrations, reducing the amount of expensive alkenyl group-containing branched organopolysiloxane needed while maintaining sufficient release force and achieving high subsequent adhesion ratio.
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 achieves a very low release force and high subsequent adhesion ratio, enabling efficient peeling of pressure-sensitive adhesive sheets while maintaining strong adhesion, thus improving the practical utility and cost-effectiveness.
Implementation Method 1
comprising components (a) to (d) below: (a) 100 parts by weight of organopolysiloxane having two or more alkenyl groups per molecule, other than component (b); (b) 0.1 to 20 parts by weight of easy release additive; (c) 0.1 to 30 parts by weight of organohydrogenpolysiloxane having two or more silicon-bonded hydrogen atoms per molecule; and (d) platinum group metal catalyst at a platinum metal weight, based on the overall composition, of from 10 to 1,000 ppm
Implementation Method 2
the easy release additive is an acrylic-silicone graft copolymer which has a weight-average molecular weight of from 1,000 to 100,000 and is obtainable by radical polymerizing (A) an acrylic group and/or methacrylic group-containing organopolysiloxane compound with (B) a radical polymerizable monomer having one radical polymerizable group per molecule
Data Source
AI summary
Provided is a light release additive for release sheets, the additive being capable of achieving a desired light release force with a small addition thereof to an organopolysiloxane composition for release sheets and of providing an excellent release coating such that the released adhesive sheet has a high subsequent adhesion. This light release additive for release sheets comprises an acryl-silicone-based graft copolymer with a weight-average molecular weight of 1,000 to 100,000 obtained by radical polymerization of (A) an organopolysiloxane compound having an acrylic group and/or a methacrylic group and (B) a radical polymerizable monomer having one radical polymerizable group per molecule.