Sulfonated Block Copolymer Adhesive High-Temperature Shear Strength
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Pressure-sensitive adhesives based on styrene block copolymers exhibit weaknesses in bond strength at temperatures above 50 °C due to softening of hard phases, leading to cohesive failure, especially under tilting shear loads, which limits their application in high-temperature environments.
Innovation Solution
A temperature-stable adhesive comprising block copolymers with a structure A-B-A, (A-B) n, or (A-B-A) n X, where X is a coupling reagent, and at least partially sulfonated vinyl aromatic blocks, combined with adhesive resins and metal complexes, providing enhanced cohesion and shear properties through crosslinking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If styrene block copolymers are used to achieve high bonding strength and cohesion, then adhesive strength is improved, but temperature stability deteriorates above 50 °C due to softening of hard phases
Solution Approach 1:
The patent applies parameter changes by introducing sulfonation to the vinyl aromatic blocks, which fundamentally alters the thermal and mechanical properties of the hard phases. The sulfonated blocks maintain their structural integrity at elevated temperatures, preventing the softening that occurs with conventional styrene blocks above 50 °C. This chemical modification changes the glass transition temperature and thermal stability parameters of the adhesive system.
Solution Approach 2:
The patent creates a composite adhesive system combining sulfonated vinyl aromatic blocks with metal chelates. The metal chelates form crosslinked networks within the polymer matrix, creating a composite structure that enhances both cohesion and temperature resistance. This composite approach allows the adhesive to maintain strength at high temperatures while preserving bonding capabilities.
2Ease of operation
If hard phases are softened to improve adhesion on rough surfaces, then bonding capability is improved, but cohesive failure occurs at elevated temperatures
Solution Approach 1:
Sulfonation of the vinyl aromatic blocks changes the thermal and mechanical parameters of the hard phases, allowing them to maintain appropriate hardness and cohesion at elevated temperatures while still providing adequate surface bonding capability at room temperature.
Solution Approach 2:
Metal chelates act as intermediaries that form crosslinked networks between polymer chains, providing cohesive stability at high temperatures while allowing the sulfonated blocks to maintain their bonding function at lower temperatures.
3Temperature
If crosslinking is increased to improve temperature resistance, then shear properties are improved, but processing complexity increases
Solution Approach 1:
The sulfonated vinyl aromatic blocks self-organize and form crosslinked structures through metal chelate coordination without requiring complex external processing. The crosslinking occurs naturally during adhesive formulation or application, simplifying the overall process while achieving high temperature resistance.
Solution Approach 2:
The sulfonation modifies the chemical parameters of the polymer to enable spontaneous crosslinking with metal chelates, reducing the need for complex processing equipment or multi-step procedures while achieving the desired temperature resistance and shear properties.
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 adhesive achieves excellent bonding strength and temperature resistance, with Shear Adhesion Failure Temperature (SAFT) values exceeding 150 °C, enabling reliable bonding at high temperatures without losing adhesive strength.
Implementation Method 1
enhanced cohesion and shear properties through crosslinking
Implementation Method 2
metal complexes with a substitutable complexing agent
Implementation Method 3
adhesive resins and metal complexes, providing enhanced cohesion and shear properties
Implementation Method 4
block copolymers with a structure A-B-A, (A-B) n, or (A-B-A) n X... providing enhanced cohesion
Data Source
Figure 1~2
Figure 3
AI summary
The invention relates to an adhesive compound, in particular a temperature-stable adhesive compound, comprising (i) block copolymers and mixtures thereof with an A-B-A, (A-B)n, (A-B)nX, or (A-B-A)nX structure, in which X is the group of a coupling reagent, n is a whole number between 2 and 10, A is a polymer block of a vinyl aromate, and B is a polymer block of an alkene or diene, wherein said polymer block can also be a hydrated polymer block, with the proviso that at least some of the A blocks are sulfonated, optionally as admixture components of two-block copolymers in the A-B form, (ii) at least one adhesive resin, and (iii) at least one metal complex with a substitutable complexing agent.