Rubber Composition Stiffness via Phenol-Aldehyde Resin
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Solution Overview
Problem
Conventional rubber compositions used in tires face challenges in achieving high stiffness without compromising fluidity and mechanical properties, particularly due to issues like sulfur migration, reduced vulcanization time, and the environmental impact of formaldehyde production during vulcanization.
Innovation Solution
A rubber composition incorporating a phenol-aldehyde resin based on an aromatic polyphenol and a specific aldehyde with a connecting group that separates aromatic rings by at least 2 covalent bonds, enhancing stiffness while maintaining fluidity and avoiding formaldehyde production.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a concentrated vulcanization system with high sulfur and accelerator content is used to achieve high stiffness, then the stiffness during small strains is improved, but sulfur migration to the surface occurs causing blooming and degradation of green tack
Solution Approach 1:
The patent extracts and removes the concentrated vulcanization system (high sulfur and accelerator content) from the rubber composition. By eliminating this problematic system, the patent prevents sulfur migration and blooming while maintaining stiffness through alternative means such as optimized filler reinforcement and controlled crosslinking density, thereby resolving the contradiction between achieving high stiffness and preventing harmful sulfur migration.
Solution Approach 2:
The patent changes the parameters of the vulcanization system by reducing sulfur and accelerator content to conventional levels. This parameter change prevents the blooming phenomenon while maintaining the desired stiffness through optimized composition formulation, including the use of specific filler types and ratios, thereby resolving the technical contradiction.
2Strength
If a concentrated vulcanization system is used to achieve high stiffness, then the stiffness during small strains is improved, but the delay phase during vulcanization is reduced leading to premature curing
Solution Approach 1:
The patent extracts and eliminates the concentrated vulcanization system that causes premature curing. By removing the high accelerator content responsible for the reduced delay phase, the patent restores appropriate vulcanization timing while maintaining stiffness through alternative reinforcement mechanisms, thereby resolving the contradiction between high stiffness and adequate delay phase.
Solution Approach 2:
The patent changes the vulcanization parameters by reducing accelerator content to conventional levels, which increases the delay phase and prevents premature curing. Simultaneously, the patent maintains the desired stiffness through optimized filler reinforcement and crosslinking density, thereby resolving the technical contradiction.
3Strength
If the content of reinforcing filler is increased to achieve high stiffness, then the stiffness is improved, but the hysteresis properties and rolling resistance properties are detrimentally affected
Solution Approach 1:
The patent optimizes the parameters of filler reinforcement by selecting specific filler types, sizes, and ratios that provide high stiffness with minimized impact on hysteresis properties. This optimized reinforcement approach maintains the desired stiffness while reducing the detrimental effect on rolling resistance, thereby resolving the technical contradiction.
Solution Approach 2:
The patent uses composite material strategies by combining different types of fillers (e.g., carbon black and silica) in optimized ratios to achieve high stiffness while minimizing hysteresis losses. This composite approach allows the patent to resolve the contradiction between stiffness and rolling resistance by leveraging the complementary properties of different fillers.
4Strength
If conventional methylene donor compounds like HMT or H3M are used with phenolic resin to achieve high stiffness, then the stiffness is improved, but formaldehyde is produced during vulcanization causing environmental harm
Solution Approach 1:
The patent extracts and removes conventional methylene donor compounds (HMT, H3M) that produce formaldehyde during vulcanization. By eliminating these harmful compounds, the patent prevents formaldehyde production while maintaining the desired stiffness through alternative crosslinking mechanisms and optimized phenolic resin formulation, thereby resolving the contradiction between high stiffness and environmental harm.
Solution Approach 2:
The patent replaces conventional methylene donors with alternative compounds that do not produce formaldehyde. This substitution uses environmentally friendly alternatives that achieve the same crosslinking function without the harmful byproducts, thereby resolving the technical contradiction between stiffness enhancement and environmental protection.
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 provides rubber compositions with improved stiffness and fluidity, maintaining mechanical properties and reducing environmental impact by preventing formaldehyde generation during vulcanization.
Implementation Method 1
The terms 'methylene acceptor' and 'methylene donor' are well known to those skilled in the art and are widely used to denote compounds capable of reacting together to generate, by condensation, a three-dimensional reinforcing resin
Implementation Method 2
The combination of the aldehyde and of the aromatic polyphenol of the composition according to the invention makes it possible to obtain rubber compositions having an equivalent or even vastly improved stiffness at low strain
Implementation Method 3
SP is a connecting group that connects at least the Ar1 and Ar2 groups to one another, SP separating the Ar1 and Ar2 groups by at least 2 covalent bonds
Implementation Method 4
storage of the uncured composition containing a concentrated vulcanization system is liable to lead to a reduction in the delay phase of the composition during vulcanization thereof
Data Source
AI summary
A rubber composition comprises at least one phenol-aldehyde resin based on: at least one aromatic polyphenol comprising at least one aromatic ring bearing at least two —O—H groups in the meta position relative to one another, the two positions ortho to at least one of the —O—H groups being unsubstituted; and at least one aldehyde of formula W:wherein each Ar1 and Ar2 group represents, independently of one another, an optionally substituted aromatic ring; and wherein SP is a connecting group that connects at least the Ar1 and Ar2 groups to one another, SP separating the Ar1 and Ar2 groups by at least 2 covalent bonds.