Farnesene Block Copolymer for Tire Ice Grip and Rolling Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing rubber compositions for tires, particularly those containing farnesene-based polymers, fall short in achieving optimal fuel economy (rolling resistance performance) and steering stability on icy or snowy roads (ice grip performance).
Innovation Solution
A block copolymer comprising a polymer block A with farnesene-derived monomers and a random copolymer block B containing C12 or lower conjugated diene and aromatic vinyl compound-derived monomers, with specific mass ratios and molecular weight ranges, is developed. This block copolymer is produced through controlled polymerization methods, including living anionic polymerization, and is incorporated into a rubber composition with a filler to enhance tire performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a branched conjugated diene copolymer is used to improve grip performance, then ice grip performance is improved, but rolling resistance performance deteriorates
Solution Approach 1:
The patent divides the polymer into distinct blocks: a conjugated diene polymer block (A) for elasticity and a random copolymer block (B) containing aromatic vinyl units for grip performance. This segmentation allows each block to contribute its specific properties without the negative effects of a fully branched structure, resolving the contradiction between ice grip and rolling resistance.
Solution Approach 2:
The patent creates a composite block copolymer structure combining two different polymer types: a conjugated diene polymer block and a random copolymer block containing aromatic vinyl compounds. This composite structure integrates the advantages of both components, achieving improved ice grip performance while maintaining acceptable rolling resistance characteristics.
2Reliability
If the content of aromatic vinyl compound-derived monomer unit in random copolymer block B is increased to improve ice grip performance, then ice grip performance is improved, but the complexity of polymer composition increases
Solution Approach 1:
The patent specifies precise parameter ranges for the aromatic vinyl compound-derived monomer unit content in block B (5-60 mass%) and the block ratio A/B (20/80 to 80/20). By controlling these parameters within defined ranges, the patent achieves optimal ice grip performance while managing polymer composition complexity through quantifiable specifications rather than open-ended formulations.
3Strength
If the weight average molecular weight is increased to improve tensile strength, then tensile strength is improved, but processing difficulty increases
Solution Approach 1:
The patent defines a specific weight average molecular weight range (100,000-5,000,000) for the block copolymer. This parameter control allows optimization of tensile strength while maintaining processability, as the range is constrained to balance mechanical properties with manufacturing feasibility.
Solution Approach 2:
The block copolymer structure with distinct blocks A and B provides inherent processing advantages. The conjugated diene block (A) contributes to elasticity and processability, while the random copolymer block (B) provides strength, allowing the overall molecule to achieve high tensile strength without proportionally increasing processing difficulty.
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 block copolymer significantly improves both rolling resistance performance and ice grip performance of tires, providing a balance of mobility and traction on various road conditions.
Implementation Method 1
a step of polymerizing a monomer containing farnesene in the presence of an organic metal initiator to produce a living polymer containing the polymer block A
Implementation Method 2
a step of polymerizing monomers containing a C12 or lower conjugated diene and an aromatic vinyl compound in the presence of the living polymer containing the polymer block A obtained in Step 1-1 to produce a living block copolymer containing the polymer block A and the random copolymer block B
Data Source
AI summary
The present invention relates to a block copolymer that contains a polymer block A containing a farnesene-derived monomer unit (a1) and a random copolymer block B containing a C12 or lower conjugated diene-derived monomer unit (b1) and an aromatic vinyl compound-derived monomer unit (b2), the block copolymer having a ratio by mass of the polymer block A to the random copolymer block B (A/B) of 30/70 to 0.5/99.5, a content of the aromatic vinyl compound-derived monomer unit (b2) in the random copolymer block B of 1 to 50% by mass, and a weight average molecular weight (Mw) of 100,000 to 5,000,000.