Silane-Terminated Curable Composition for High Modulus and Elongation
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Solution Overview
Problem
There is a need for curable compositions based on silane-terminated polymers that exhibit improved mechanical properties, particularly high modulus and elongation, while meeting the requirements of modern adhesives, sealants, and coatings.
Innovation Solution
A curable composition comprising a specific combination of silane-terminated polymers with terminal groups of the formula -A n -R-SiXYZ and a compound of the formula R'-SiXYZ, where A is a divalent bonding group, R is a hydrocarbon residue, X, Y, Z are hydroxyl or alkoxy/acyloxy groups, and n is 0 or 1, along with a silicone compound, to enhance mechanical properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If silane-terminated polymers are used to form crosslinked networks, then adhesion to substrates is improved, but mechanical properties (modulus and elongation) are insufficient
Solution Approach 1:
The patent changes the chemical parameters of the silane-terminated polymer by introducing specific terminal groups (formula I with divalent bonding groups A and hydrocarbon residues R) and controlling the substitution patterns on the silicon atom. This parameter modification enables the polymer to achieve both good adhesion and improved mechanical properties including higher modulus and elongation after curing.
Solution Approach 2:
The patent creates a composite crosslinked network system by combining silane-terminated polymers with specific terminal groups (formula I) with compounds containing silicon atoms with hydrolyzable substituents (formula II). This composite approach allows the formation of a three-dimensional network that integrates the adhesion benefits of silane-terminated polymers with the mechanical property enhancements from the crosslinking reaction.
2Strength
If crosslinking density is increased to improve mechanical strength, then modulus increases, but elongation decreases
Solution Approach 1:
The patent introduces local structural variations in the crosslinked network by using silane-terminated polymers with specific terminal groups (formula I) that have different bonding characteristics. The divalent bonding groups A and hydrocarbon residues R create localized structural features that allow the network to achieve high modulus in certain regions while maintaining elongation capability through the flexible polymer backbone structure.
Solution Approach 2:
The patent modifies the crosslinking parameters by controlling the type and concentration of silane-terminated polymer terminal groups (formula I) and the corresponding crosslinking agents (formula II). This parameter control enables optimization of the balance between modulus and elongation by adjusting the crosslink density and network architecture rather than simply increasing crosslinking intensity.
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 achieves improved tensile strength and elongation, with controlled network configuration influencing elasticity, flexibility, and heat resistance, suitable for various applications including adhesives and sealants.
Implementation Method 1
In the presence of atmospheric moisture, polymers having silyl groups with hydrolyzable substituents are already capable of condensing with one another at room temperature, splitting off the hydrolyzed residues
Implementation Method 2
polymers having silyl groups with hydrolyzable substituents are already capable of condensing with one another at room temperature, splitting off the hydrolyzed residues
Data Source
AI summary
The invention relates to a curable composition comprising a) at least one polymer having at least one terminal group of the general formula (I) -An-R-SiXYZ (I), wherein A is a divalent bonding group containing at least one heteroatom, R is selected from divalent hydrocarbon residues having 1 to 12 carbon atoms, X, Y, Z are, independently of one another, selected from the group consisting of a hydroxyl group and C1 to C8 alkyl, C1 to C8 alkoxy, and C1 to C8 acyloxy groups, wherein X, Y, Z are substituents directly bound with the Si atom or the two of the substituents X, Y, Z form a ring together with the Si atom to which they are bound, and at least one of the substituents X, Y, Z is selected from the group consisting of a hydroxyl group, C1 to C8 alkoxy or C1 to C8 acyloxy groups, and n is 0 or 1; and b) at least one compound of the general formula (II) wherein R' is same or different and is, independently from one another, selected from the group consisting of a hydrogen atom and hydrocarbon residues having 1 to 12 carbon atoms, and Ar is selected from aryl groups, and adhesive, sealant, or coating materials comprising the composition and use thereof.