Void-Containing Release Film for Heat-Stable Cavity Formation
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Solution Overview
Problem
Existing release films using polyolefin resins as cavity generators face issues with thermal degradation, poor film formability, and low recyclability due to the use of surfactants and polyethylene glycol, leading to decreased whiteness and poor material recyclability, especially in release films used as separators like labels.
Innovation Solution
Incorporating a trace amount of silicone resin into the polyolefin resin composition, along with a specific layer configuration, enhances heat resistance and maintains cavity generation properties, improving lightness, film formability, and concealing properties while allowing for recyclability by forming a release layer with recycled silicone resin.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If dispersants such as surfactants and polyethylene glycol are added to finely disperse polyolefin resin, then cavity generation is improved, but the polyolefin resin is deformed during heat stretching and heat setting, causing cavities to be crushed and lightness and cushioning properties to deteriorate
Solution Approach 1:
A silicone resin layer is introduced as an intermediary between the polyolefin resin and the polyester resin matrix. This silicone resin layer acts as a protective barrier that prevents deformation of the polyolefin resin particles during heat stretching and heat setting processes, thereby maintaining cavity integrity while allowing the polyolefin resin to function as an effective cavity generator
Solution Approach 2:
The invention creates a composite structure consisting of multiple layers: a silicone resin layer, a polyolefin resin layer, and a polyester resin layer. This composite material approach allows each layer to perform its specific function - the silicone resin layer protects against deformation, the polyolefin resin generates cavities, and the polyester resin provides the base structure, thereby resolving the contradiction between cavity generation and cavity integrity
2Manufacturing precision
If surfactants and polyethylene glycol are used as dispersants, then polyolefin resin is finely dispersed, but thermal degradation occurs during melt extrusion, causing whiteness to decrease and film formability to deteriorate
Solution Approach 1:
The silicone resin layer serves as a thermal protective intermediary during the melt extrusion process. It shields the polyolefin resin and dispersants from direct exposure to high temperatures, preventing thermal degradation and maintaining whiteness and film formability while still allowing fine dispersion to occur
Solution Approach 2:
The invention changes the thermal parameters of the system by introducing silicone resin, which has different thermal stability characteristics. This modifies the overall thermal behavior of the composite material during extrusion, allowing the process to proceed at temperatures that enable fine dispersion without causing degradation of the polyolefin resin or film quality
3Ease of operation
If a release layer is applied to the film, then releasability is improved, but material recyclability deteriorates due to adhesive layer residue
Solution Approach 1:
The invention applies a release layer made of silicone resin that can be easily separated from the substrate after use. This allows the release layer to be discarded along with the adhesive residue, and the remaining film material to be recovered and recycled, thereby maintaining both releasability and material recyclability
Solution Approach 2:
The release layer is designed as a disposable component that is intentionally made easily separable. After serving its function of preventing adhesion, it is discarded along with the adhesive layer, while the main film material is recovered for recycling, thus resolving the contradiction between releasability and recyclability
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 resulting release film exhibits excellent environmental compatibility, lightness, film formability, and whiteness, with reduced thermal degradation and improved recyclability, maintaining cavity generating properties even with recycled materials.
Implementation Method 1
improve heat resistance of dispersed polyolefin particles in a polyester resin and to reduce deformation of dispersed polyolefin particles during heat stretching and heat setting
Implementation Method 2
causes interfacial peeling between the polyester resin and the immiscible resin, and cavities are thus generated
Implementation Method 3
a release layer C on at least one surface of the laminated film
Data Source
AI summary
A release film comprising: a laminated film in which a first coating layer B1 containing a polyester resin containing an inorganic pigment, a void-containing layer A containing voids therein, and a second coating layer B2 containing a polyester resin containing an inorganic pigment are laminated in this order; and a release layer C on at least one side of the laminated film, wherein the void-containing layer A is made of a composition containing a polyester resin, a polyolefin resin, and a silicone resin, and has an apparent density of 0.80 g/cm3 or more and 1.20 g/cm3 or less.