Silane-Modified Adhesive Composition for High Tack, Easy Mixing
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Solution Overview
Problem
Existing adhesive and sealant compositions with high initial tack face challenges in production due to high viscosity, requiring specialized equipment for mixing and leading to issues like slumping and inadequate bonding strength, especially in inclined or vertical applications, and they often rely on organoclay-based rheology controllers that need high shear forces and can cause turbidity.
Innovation Solution
A method involving the use of silane-modified polymers with specific silane groups and hydrophobic fumed silica, combined with an oligomeric siloxane rheology modifier, to create a composition with tunable tack values, eliminating the need for organoclay-based controllers and reducing viscosity issues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If high initial tack is achieved in adhesive composition, then bonding strength is improved, but viscosity increases making mixing and pumping troublesome
Solution Approach 1:
The patent changes the chemical parameters of the adhesive composition by incorporating specific silane-modified polymers with controlled hydrolysable group content (0.1-10 mmol/g) and molecular weight (10,000-1,000,000 g/mol). This allows tuning the composition to achieve high initial tack while maintaining manageable viscosity for manufacturing processes.
Solution Approach 2:
The patent uses composite material systems combining silane-modified polymers with specific additives and fillers. The silane-modified polymer serves as the base adhesive with controlled crosslinking potential, while additives modify rheological properties to balance tack and viscosity, creating a composite formulation that achieves both high bonding strength and ease of manufacture.
2Strength
If organoclay-based rheology controllers are used to increase initial tack, then tack value is improved, but high shear forces are required and turbidity occurs
Solution Approach 1:
The patent extracts or removes the organoclay-based rheology controller from the formulation and replaces it with alternative rheology modifiers that do not require high shear forces for activation and do not cause turbidity. This eliminates the harmful effects while maintaining the desired initial tack through the silane-modified polymer system.
Solution Approach 2:
The patent replaces complex organoclay systems with simpler, more compatible rheology modifiers that are easier to work with and do not require specialized processing conditions. The alternative additives provide similar functional benefits without the drawbacks of turbidity and high shear requirements.
3Strength
If two-component composition is used with high initial tack, then one component has high viscosity, but mixing becomes impaired
Solution Approach 1:
The patent optimizes the molecular weight and hydrolysable group content parameters of the silane-modified polymer to achieve a balance where the adhesive provides high initial tack while maintaining lower viscosity. This allows both components to be mixed easily without requiring specialized equipment while still achieving the desired bonding performance.
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 method allows for a broad range of tack values, including high tack, without specialized equipment, improving bonding strength and reducing production complexity, while maintaining homogeneity and avoiding turbidity.
Implementation Method 1
the silane-groups comprise hydrolysable groups. These silane-modified polymers are capable, even at room temperature, of condensing with one another by elimination of the hydrolysable groups.
Implementation Method 2
condensing with one another by elimination of the hydrolysable groups
Implementation Method 3
at least one hydrophobic fumed silica (S)
Data Source
AI summary
A method for manufacturing a composition (C) suitable for use as a sealant and/or adhesive which comprises the steps of: step 1: mixing at least one silane-modified polymer (P) with at least one hydrophobic fumed silica (S) having a BET surface area of at least 50 m2/g so as to obtain a mixture (M), wherein said mixture (M) has a tack value To, measured in accordance with the rheological tack test method, equal to or less than 1000 Pa; step 2: adding to the mixture (M) as obtained in step 1, at least one rheology modifier (R) thereby forming the composition (C).