Hydrogenated Block Copolymer Composition for Low-Temperature Flexibility
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Solution Overview
Problem
Existing hydrogenated styrene-based elastomers face challenges in maintaining flexibility, rubber elasticity, and mechanical strength at low temperatures, particularly below −40°C, and there is a need to improve compatibility between oil components and hydrogenated block copolymers for applications in lubricating oils and cosmetics.
Innovation Solution
A hydrogenated block copolymer with specific structural units derived from aromatic vinyl and conjugated diene compounds, characterized by a glass transition temperature of −50°C or lower, controlled molecular weight, and reduced crystallization, achieved through precise polymerization and hydrogenation conditions, ensuring uniform distribution of butadiene and isoprene units.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a polymer block composed of only 1,4-butadiene segment is used, then the hydrogenated product has low Tg, but the polymer block is crystallized and flexibility is lost
Solution Approach 1:
The patent applies local quality by creating a heterogeneous structure within the polymer block, where 1,4-butadiene segments (providing low Tg) and 1,2-butadiene segments (preventing crystallization) are distributed throughout the same block. This allows different regions of the polymer to perform different functions: the 1,4-segments maintain low glass transition temperature while the 1,2-segments prevent crystallization, thereby preserving flexibility.
Solution Approach 2:
The patent effectively creates a composite material at the molecular level by combining two types of butadiene segments (1,4 and 1,2) within the same polymer block. This composite structure allows the material to simultaneously exhibit properties of both segment types: the low Tg characteristic of 1,4-polybutadiene and the non-crystalline, flexible nature of 1,2-polybutadiene.
2Ease of operation
If a large amount of 1,2-butadiene segment is incorporated to prevent crystallization, then flexibility is maintained, but Tg increases and low temperature properties deteriorate
Solution Approach 1:
The patent applies parameter changes by precisely controlling the composition ratio of 1,4-butadiene and 1,2-butadiene segments, the molecular weight of the polymer block, and the hydrogenation conditions. By optimizing these parameters, the patent achieves a balance where sufficient 1,2-segments prevent crystallization while the majority 1,4-segments maintain low Tg, thereby preserving both flexibility and low-temperature properties.
3Temperature
If the chain structure of hydrogenated 1,4-butadiene segment is long, then the crystallization temperature becomes high, but flexibility and impact resistance are lowered
Solution Approach 1:
The patent applies segmentation by introducing 1,2-butadiene segments that act as interruptions or segments within the 1,4-butadiene chain structure. These 1,2-segments divide the continuous 1,4-chain into shorter effective segments, preventing the formation of long crystallizable regions while maintaining the low Tg characteristic of 1,4-segments. This segmented structure prevents crystallization and preserves flexibility.
4Ease of operation
If farnesene is used to improve low temperature characteristics, then flexibility and rubber elasticity are enhanced, but cost increases and mechanical strength decreases
Solution Approach 1:
The patent applies this principle by replacing the expensive farnesene monomer with cheaper, readily available butadiene and isoprene monomers. The conventional wisdom suggested farnesene was necessary for low-temperature flexibility, but this patent demonstrates that carefully controlled copolymerization of standard monomers can achieve the same effect at lower cost, effectively substituting an expensive 'specialty' material with cheaper commodity chemicals.
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 enhanced flexibility, rubber elasticity, and mechanical strength at low temperatures, along with improved compatibility and thickening properties in gel compositions, suitable for lubricating oils, greases, and cosmetics.
Implementation Method 1
hydrogenated product of block copolymer containing a polymer block (A) composed of a structural unit derived from an aromatic vinyl compound and a polymer block (B) composed of a structural unit derived from a conjugated diene compound
Data Source
AI summary
A hydrogenated product of a block copolymer; a resin composition; and a method for producing the hydrogenated product of the block copolymer. The hydrogenated product of the block copolymer contains a polymer block (A) containing a structural unit derived from an aromatic vinyl compound and a polymer block (B) containing a structural unit derived from a conjugated diene compound, and satisfies: (1) the structural unit derived from the conjugated diene compound has structural units derived from butadiene and isoprene, but not from farnesene; (2) the hydrogenated product of the block copolymer has a glass transition temperature of −50° C. or lower; and (3) when a weight average molecular weight of the hydrogenated product of the block copolymer is defined as x and a crystallization temperature of the hydrogenated product of the block copolymer is defined as y (° C.), 5.8x/100,000-y>17 is satisfied.