Silicone Release Coating Composition with Functional Silica

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing silicone release coating compositions exhibit high cure density, resulting in high release force, which is not suitable for applications requiring low release force and stable adhesion to substrates.

Innovation Solution

A silicone release coating composition comprising an organopolysiloxane with alkenyl groups, silicon-bonded hydrogen atoms, organic modified functional silica particles, and a hydrosilylation reaction catalyst, along with optional inhibitors and anchorage additives, is formulated to achieve a low release force and improved adhesion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If conventional silicone release coating compositions are used, then the coating forms a dense cured structure, but the release force becomes too high for applications requiring low release force

Engineering Contradiction:
Improverelease forceVSAvoidadhesion to substrate
Core Design Contradiction:
ForceVSReliability

Solution Approach 1:

The coating composition creates different local structures: hydrophobic silica particles create low-energy release surfaces while hydrophilic silica particles provide strong substrate adhesion. This local differentiation allows the coating to simultaneously achieve low release force and reliable substrate bonding.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The invention changes the particle size parameter of silica, using a bimodal distribution with small particles (0.1-5 μm) for release properties and large particles (5-15 μm) for adhesion properties. This parameter variation enables the coating to satisfy conflicting requirements of low release force and strong substrate bonding.

Inventive Principle:
Principle #35Parameter changes

2Strength

If high cure density is achieved, then the coating structure becomes more robust, but the release force increases making it unsuitable for low release force applications

Engineering Contradiction:
Improvecoating structure strengthVSAvoidrelease force
Core Design Contradiction:
StrengthVSForce

Solution Approach 1:

The invention uses a composite system combining hydrophobic and hydrophilic silica particles with organopolysiloxane resin. This composite structure provides both mechanical strength from the cured resin network and controlled release properties from the hydrophobic particles, resolving the contradiction between structural robustness and low release force.

Inventive Principle:
Principle #40Composite materials

3Reliability

If the coating provides strong anchorage to substrate, then the adhesion improves, but the release force may become inconsistent or too high

Engineering Contradiction:
Improveanchorage to substrateVSAvoidrelease force stability
Core Design Contradiction:
ReliabilityVSForce

Solution Approach 1:

Hydrophilic silica particles are positioned at the substrate interface to provide strong anchorage through hydrogen bonding and adhesion, while hydrophobic silica particles form the outer release surface. This local functional differentiation ensures stable release force while maintaining reliable substrate anchorage.

Inventive Principle:
Principle #3Local quality

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 forms a cured release coating with reduced release force and enhanced slipperiness, while maintaining suitable peel resistance and adhesion to substrates, making it suitable for applications like pressure-sensitive tapes and labels.

Implementation Method 1

an organopolysiloxane having at least two alkenyl groups in a molecule, an organopolysiloxane having at least two silicon-bonded hydrogen atoms in a molecule

Methodology Applied
Scientific EffectHydrosilylation reaction: Chemical Bonding

Implementation Method 2

organic modified functional silica particles having an average particle size of 5 μm to 15 μm and a BET specific surface area of 600 m²/g or more

Methodology Applied
Scientific EffectAdsorption: Adsorption

Data Source

PatentEP3368622B1Silicone release coating composition and article having cured release coating
Publication Date: 2020.10.14 DOW (SHANGHAI) HOLDING CO LTD

AI summary

This invention relates to a silicone release coating composition comprising : (A) an organopolysiloxane having at least two alkenyl groups in a molecule, (B) an organopolysiloxane having at least two silicon-bonded hydrogen atoms in a molecule, (C) organic modified functional silica particles having an average particle size of 5 μm to 15 μm and a BET specific surface area of 600 m2/g to 800 m2/g, and (D) a hydrosilylation reaction catalyst. The composition can form a coating with a lower release force to sticky adhesive.