Rubber Composition with Low-Tg Resin and Silane Coupling Agent
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current tire compositions face challenges in simultaneously reducing rolling resistance while maintaining other performance properties, such as viscosity and industrial processability, due to limitations in the use of silica as a reinforcing filler and low-Tg resins.
Innovation Solution
A rubber composition incorporating a diene elastomer, silica as the predominant reinforcing filler, a hydrocarbon resin with a glass transition temperature between -40°C and 20°C, a hydroxysilane polysulfide coupling agent, and a primary amine, optimized to balance rolling resistance and viscosity, with a specific formulation that excludes guanidine derivatives and zinc.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If silica is used as reinforcing filler to reduce rolling resistance, then rolling resistance is improved, but viscosity and processability deteriorate
Solution Approach 1:
A silane coupling agent is introduced as an intermediary substance between silica and the rubber matrix. The coupling agent chemically bonds to both silica and rubber, creating a bridging layer that improves the interfacial adhesion. This mediator allows silica to effectively reduce rolling resistance while the coupling agent prevents excessive viscosity increase by improving dispersion and reducing filler-filler interactions.
Solution Approach 2:
The patent modifies the surface chemistry parameters of silica through silane treatment, changing its hydrophilicity and reactivity. By controlling the silane coupling agent composition and treatment conditions, the filler's interaction with the rubber matrix is optimized, enabling reduced rolling resistance without compromising processability.
2Ease of manufacture
If low-Tg resin is used to improve green tack and processability, then viscosity is improved, but rolling resistance increases
Solution Approach 1:
Instead of changing the resin's Tg parameter, the patent optimizes the concentration and molecular weight distribution of the low-Tg resin. By carefully controlling these parameters, the resin provides sufficient plasticization for processability while minimizing its negative impact on rolling resistance through optimized viscoelastic properties.
Solution Approach 2:
The patent creates a composite plasticizing system combining low-Tg resin with properly treated silica filler. The silane-coupled silica compensates for the rolling resistance increase caused by low-Tg resin, while the resin maintains processability. This composite approach allows both components to contribute their strengths while mitigating their weaknesses.
3Loss of energy
If high-Tg resin is used to reduce rolling resistance, then rolling resistance is improved, but processability deteriorates
Solution Approach 1:
The patent merges high-Tg resin and low-Tg resin in a blended plasticizing system. The high-Tg resin component contributes to reduced rolling resistance, while the low-Tg resin component maintains processability. The silane-coupled silica filler works synergistically with this blended system to optimize both performance parameters simultaneously.
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 an improved compromise between rolling resistance, viscosity, and industrial processability, enhancing the overall performance of tire compositions without adverse effects on other properties.
Implementation Method 1
a hydroxysilane polysulfide corresponding to the general formula (I)... as coupling agent
Implementation Method 2
document WO-2014/180673 describes the use of a primary amine for reducing the hysteresis of diene rubber compositions comprising silica as predominant reinforcing filler
Implementation Method 3
a plasticizing system comprising at least one hydrocarbon resin with a glass transition temperature (Tg) of between −40° C. and 20° C.
Data Source
AI summary
A rubber composition is based on at least a diene elastomer; 50 to 160 phr (parts by weight per hundred parts by weight of elastomer) of inorganic reinforcing filler; a vulcanization system; a plasticizing system comprising at least one hydrocarbon resin with a glass transition temperature (Tg) of between −40° C. and 20° C.; as coupling agent, a hydroxysilane polysulfide corresponding to the general formula (I): (HO)aR(3-a)Si—R′—Sx—R′—SiR(3-b) (OH)b (I), in which the R radicals, which are identical or different, are hydrocarbon groups preferably comprising from 1 to 15 carbon atoms, the R′ radicals, which are identical or different, are divalent connecting groups preferably comprising from 1 to 18 carbon atoms, a and b, which are identical or different, are equal to 1 or 2, x is a number greater than or equal to 2; and a primary amine of formula (IV): R—NH2(IV), in which R represents a linear or branched hydrocarbon group comprising from 8 to 24 carbon atoms. The composition is devoid of or comprises less than 0.5 phr of guanidine derivative.