Rubber Wet Master Batch Carbon Black Dispersibility
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Solution Overview
Problem
Existing rubber wet master batch techniques fail to achieve a balance between low exothermic performance and fatigue resistance in vulcanized rubber due to poor dispersibility and structural fracture of carbon black species with different nitrogen adsorption specific surface areas.
Innovation Solution
A method involving the use of two carbon black species with specific nitrogen adsorption specific surface areas, where one with a lower area (130 m2/g or less) improves low exothermic performance and the other with a higher area (by 25 m2/g or more) enhances fatigue resistance, by optimizing dispersing conditions to prevent structural fracture and ensure even dispersibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If two carbon black species with different nitrogen adsorption specific surface areas are used to improve both low exothermic performance and fatigue resistance, then the vulcanized rubber shows improved mechanical properties, but the dispersibility of carbon black species deteriorates leading to poor dispersion or structural fracture
Solution Approach 1:
The patent applies parameter changes by optimizing the dispersing conditions (rotor rotation number and dispersing period) based on the nitrogen adsorption specific surface area of different carbon black species. For carbon black species A (N2SA ≤ 130 m2/g), the dispersing period α(A) and rotor rotation number β(A) are controlled to satisfy α(A)×β(A) ≤ 1.5α(B)×β(B). For carbon black species B (N2SA > 130 m2/g), the dispersing period α(B) and rotor rotation number β(B) are controlled to satisfy α(B)×β(B) ≥ (1.1 to 1.5)α(A)×β(A). This parameter optimization ensures both species achieve adequate dispersibility without structural fracture, resolving the contradiction between improving fatigue resistance and maintaining dispersibility.
2Reliability
If carbon black species A with high nitrogen adsorption specific surface area is dispersed to improve fatigue resistance, then fatigue resistance improves, but the dispersing energy required increases and dispersibility deteriorates
Solution Approach 1:
The patent optimizes dispersing parameters by controlling the product of dispersing period and rotor rotation number. For carbon black species A with higher N2SA (≤ 130 m2/g), the dispersing conditions are set to satisfy α(A)×β(A) ≤ 1.5α(B)×β(B), where α and β represent dispersing period and rotor rotation number respectively. This parameter control achieves adequate dispersibility without excessive energy input, preventing both poor dispersion and unnecessary energy consumption.
3Temperature
If carbon black species B with low nitrogen adsorption specific surface area is dispersed to improve low exothermic performance, then low exothermic performance improves, but the structure of carbon black species may fracture under excessive dispersing conditions
Solution Approach 1:
The patent controls dispersing parameters to protect the structure of carbon black species B (N2SA > 130 m2/g) while achieving adequate dispersibility. The dispersing conditions are optimized to satisfy α(B)×β(B) ≥ (1.1 to 1.5)α(A)×β(A), where excessive dispersing energy is avoided. This prevents structural fracture of carbon black species B, maintaining its low exothermic performance characteristics while achieving proper dispersion in the rubber matrix.
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 method produces a vulcanized rubber with improved low exothermic performance and fatigue resistance, maintaining the structural integrity of both carbon black species, resulting in a rubber composition suitable for pneumatic tires with enhanced properties.
Implementation Method 1
dispersing the filler into the dispersing solvent to produce a filler-containing slurry solution
Implementation Method 2
mixing the resultant filler-containing slurry solution with a rubber latex solution in the phase of the liquids
Implementation Method 3
adding, after the mixing, a solidifier such as an acid thereto to solidify the mixture
Data Source
AI summary
In the step (I), the period (minute(s)) for dispersing the carbon black species A showing a nitrogen adsorption specific surface area (N2SA-(A)value) of 130 m2/g or less in the dispersing solvent and that minute(s)) for dispersing the carbon black species B showing an N2SA-(B) value lower than the N2SA-(A) value by 25 m2/g or more in the dispersing solvent by α(A) and α(B), respectively, and further representing the rotation number (rpm) of a rotor of a dispersing machine used in the dispersing when the carbon black species A is dispersed, and that (rpm) of a rotor of a dispersing machine used in the dispersing when the carbon black species B is dispersed by β(A) and β(B), respectively, the following expression is satisfied:1.1α(B)×β(B)≦α(A)×β(A)≦1.5α(B)×β(B) (1).