Strippable Adhesive Strip With Polyurethane Carrier
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Solution Overview
Problem
Existing strippable adhesive film strips often suffer from resin migration between the adhesive and carrier layers, leading to reduced adhesive strength over time, and very thin strips are prone to tearing, making them difficult to remove without leaving residue or causing damage.
Innovation Solution
A pressure-sensitive adhesive film strip with a polyurethane carrier and vinyl aromatic block copolymer-based adhesive layers, where the adhesive resins have a diacetone alcohol cloud point greater than -20 °C, ensuring minimal resin migration and maintaining high adhesive strength, and a carrier with over 50% elongation at break, allowing easy removal by stretching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the adhesive strip is made very thin to reduce device thickness, then the device can be made thinner, but the adhesive strip becomes prone to tearing during removal
Solution Approach 1:
The adhesive strip uses a composite structure combining a polyurethane carrier layer with adhesive layers containing vinyl aromatic block copolymers and resins. This composite material design provides both thin profile and tear resistance through the synergistic properties of the carrier and adhesive components.
Solution Approach 2:
The invention specifies particular parameter ranges for the adhesive components, including resins with DACP greater than -20°C and vinyl aromatic block copolymer content between 10-35 wt.%, to optimize the balance between thinness and tear resistance during the removal process.
2Stability of the object's composition
If the carrier layer and adhesive layer use similar materials to ensure compatibility, then the layers bond well, but resin migration occurs from the adhesive layer into the carrier layer over time
Solution Approach 1:
The invention applies local quality by specifying that the carrier layer be made of polyurethane while the adhesive layers contain specific resin compositions with DACP greater than -20°C. This localized material differentiation prevents resin migration while maintaining layer compatibility.
Solution Approach 2:
The polyurethane carrier layer acts as an intermediary that is compatible with the adhesive layers yet resistant to resin migration. The specific polyurethane formulation serves as a mediator that prevents resin depletion in the adhesive layer while maintaining stable bonding.
3Ease of operation
If the adhesive strip is made elastic and highly stretchable for easy removal, then the strip can be removed without residue, but the adhesive strength may be reduced
Solution Approach 1:
The adhesive strip is designed with dynamic properties through the polyurethane carrier that provides high elongation at break (at least 100%). This dynamic elasticity enables the strip to stretch during removal while maintaining adhesive strength through the specifically formulated adhesive layers.
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 solution enables easy removal of the adhesive strip without residue or damage, maintaining adhesive strength and preventing resin migration, even in thin film applications, by using a polyurethane carrier with high elongation and resilience, and vinyl aromatic block copolymer adhesives with specific resin properties.
Implementation Method 1
a carrier (1) made of a single-layer polyurethane, wherein the carrier has an elongation at break of at least 100% and a resilience of more than 50%
Implementation Method 2
an adhesive layer (2, 3) applied to both sides of the carrier, wherein the adhesive layers consist of an adhesive based on vinyl aromatic block copolymers and adhesive resins
Data Source
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AI summary
The invention relates to a pressure-sensitive adhesive film strip consisting of at least two, in particular three, layers, which can be removed without leaving residue or causing damage by stretching, essentially in the bonding plane, with a carrier on which at least one side has a first, outer adhesive layer, wherein: • the adhesive layer consists of an adhesive based on vinyl aromatic block copolymers and adhesive resins, wherein at least 75% (based on the total resin content) is selected as a resin with a DACP (diacetone alcohol cloud point) of greater than -20 °C, preferably greater than 0 °C, and • the carrier has at least one layer consisting of a polyurethane with an elongation at break of at least 100% and a recovery capacity of more than 50%. In particular, a non-polar hydrocarbon resin or a polyterpene resin serves as the tackifier for the pressure-sensitive adhesive(s).