Functionalized Rubber Blend for Tire Wet Grip and Rolling Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing tire rubber compositions face challenges in balancing improved winter properties, abrasion resistance, and rolling resistance without compromising wet grip, as silica replacement or modification of polymers and fillers often lead to trade-offs in performance.
Innovation Solution
A rubber blend comprising a high molecular weight, solution-polymerized diene polymer A and a low molecular weight, solution-polymerized polymer B, both functionalized with specific groups such as epoxy, hydroxy, or silane sulfide, which are combined in specific proportions to enhance processing and filler interaction, thereby improving tire performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If silica is used to replace carbon black in rubber mixtures, then wet grip and dry braking are improved, but rolling resistance and abrasion behavior deteriorate
Solution Approach 1:
The patent changes the molecular weight parameters of the diene rubber components, using a combination of high molecular weight (≥100,000 g/mol) and low molecular weight (1,000-10,000 g/mol) polybutadiene rubbers in specific ratios (0.1-10 parts by weight low MW to 100 parts by weight high MW). This parameter change in molecular weight distribution modifies the rubber's viscoelastic properties, allowing optimization of both wet grip and rolling resistance without the traditional trade-off imposed by silica filler alone.
Solution Approach 2:
The patent creates a composite rubber system combining high molecular weight polybutadiene rubber (providing structural integrity and abrasion resistance) with low molecular weight polybutadiene rubber (providing flexibility and wet grip). This composite approach at the molecular level, combined with silica filler, achieves synergistic effects that resolve the contradiction between wet grip improvement and rolling resistance increase.
2Adaptability or versatility
If liquid polybutadiene is added to improve winter properties, then low temperature flexibility is improved, but processing behavior and filler interaction deteriorate
Solution Approach 1:
The patent precisely controls the molecular weight of the low molecular weight polybutadiene rubber component within the range of 1,000-10,000 g/mol, with a number average molecular weight (Mn) of 1,000-5,000 g/mol. This specific parameter range provides optimal balance: low enough to ensure excellent low-temperature flexibility and winter properties, but high enough to maintain good processing behavior and adequate filler interaction, resolving the contradiction between winter performance and manufacturability.
3Strength
If functionalized polymers are used to improve filler interaction, then abrasion resistance is improved, but manufacturing complexity increases
Solution Approach 1:
The patent uses low molecular weight polybutadiene rubber (1,000-10,000 g/mol) which inherently provides good filler interaction and processing behavior without requiring complex functionalization. This simpler, shorter-chain polymer acts as an effective filler modifier, reducing manufacturing complexity while maintaining or improving abrasion resistance through optimized molecular weight rather than chemical functionalization.
Data Source
AI summary
The invention relates to a rubber blend, to a sulfur-crosslinkable rubber mixture containing the rubber blend, and to a vehicle tire containing such a rubber mixture. The rubber blend contains: at least one high-molecular-weight, solution-polymerized diene polymer A and at least one low-molecular-weight, solution-polymerized polymer B, wherein at least one of the polymers A or B is functionalized at the chain end and/or along the polymer chain and/or in a coupling center with at least one group selected from epoxy groups, hydroxy groups, carboxy groups, silane-sulfide groups, amino groups, siloxane groups, organosilicon groups, phthalocyanine groups, and from alkoxysilyl groups containing amino groups and wherein the rubber blend has 35 to 100 phr (with respect to the at least one high-molecular-weight, solution-polymerized diene polymer A), preferably 35 to 70 phr, of the at least one low-molecular-weight, solution-polymerized polymer B.