Preparation of inured asphalt blown coating
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Solution Overview
Problem
Conventional air blowing techniques struggle to achieve both the desired softening point and penetration value for asphalt used in roofing applications, often resulting in 'hard asphalts' that are unsuitable for industrial use.
Innovation Solution
Incorporating liquid high-vinyl polybutadiene with a high-vinyl microstructure content into asphalt and then air blowing the blend to produce a flexible and tough polymer modified asphalt, which can be stretched and exhibits improved thermal stability and oxidative aging performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If conventional air blowing techniques are used to increase softening point and stiffness of asphalt, then the softening point increases, but the penetration value becomes too low resulting in hard asphalt that is unsuitable for roofing applications
Solution Approach 1:
The patent changes the chemical parameters of asphalt by introducing oxygen through air blowing process, which modifies the molecular structure and creates new compounds that simultaneously increase softening point while maintaining appropriate penetration values. The controlled oxidation transforms the asphalt chemistry to achieve both desired parameters.
Solution Approach 2:
The patent employs air blowing as an oxidation process to modify asphalt properties. By introducing oxygen at controlled rates and temperatures, the asphalt undergoes chemical transformation that increases molecular weight and polarity, resulting in higher softening point while the controlled nature of oxidation prevents excessive hardening that would reduce penetration below acceptable levels.
2Temperature
If air is blown through asphalt at elevated temperatures for extended periods to achieve desired stiffness, then the softening point increases, but the processing time increases significantly
Solution Approach 1:
The patent uses controlled oxidation through air blowing to accelerate the chemical modification of asphalt. By introducing oxygen at optimized rates and maintaining controlled temperatures, the oxidation process proceeds faster than natural aging, achieving the desired softening point increase in 1-8 hours rather than extended periods, thus reducing processing time while maintaining effectiveness.
Solution Approach 2:
The patent optimizes processing parameters including temperature ranges (400-550°F), air flow rates, and blow durations (1-8 hours) to achieve efficient modification. By carefully controlling these parameters, the process achieves rapid softening point enhancement without requiring excessively long treatment times, balancing speed and effectiveness.
3Manufacturing precision
If asphalt is air blown for extended periods to achieve desired penetration value, then the penetration value improves, but energy consumption increases
Solution Approach 1:
The patent optimizes energy consumption by controlling air blowing parameters including temperature (400-550°F), air flow rate, and duration (1-8 hours). By maintaining temperatures in this optimized range and controlling the oxidation process, the patent achieves desired penetration values without excessive energy input, balancing processing efficiency with energy conservation.
Solution Approach 2:
The controlled oxidation process efficiently modifies asphalt properties by introducing oxygen at optimized rates. This accelerates the chemical changes needed to achieve target penetration values without requiring prolonged high-energy processing, thus reducing overall energy consumption while maintaining manufacturing precision.
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
This method allows for the production of asphalt with a softening point within the range of 185° F. to 250° F. and a penetration value of at least 15 dmm, making it suitable for roofing applications, while also reducing capital expenditures and operating costs by eliminating the need for high shear mills.
Implementation Method 1
the asphalt is typically treated by an air blowing process. In such air blowing techniques, air is blown through the asphalt for a period of about 1 hour to about 8 hours while it is maintained at an elevated temperature
Implementation Method 2
air is blown through the asphalt for a period of about 1 hour to about 8 hours while it is maintained at an elevated temperature which is typically within the range of 400° F. (204° C.) to 550° F. (288° C.)
Data Source
AI summary
The present invention relates to a method for preparing a flexible and tough polymer modified asphalt composition which comprises sparging an oxygen containing gas through a liquid high-vinyl polybutadiene modified asphalt, wherein the liquid high-vinyl polybutadiene modified asphalt contains from about 0.25 weight percent to about 20 weight percent of the liquid high-vinyl polybutadiene, wherein the oxygen containing gas is sparged through the liquid high-vinyl polybutadiene modified asphalt at a temperature within the range of about 400° F. to about 550° F. for a period of time which is sufficient to increase the softening point of the asphalt to a value which is within the range of 185° F. to 250° F. and to attain a penetration value of at least 15 dmm to produce the polymer modified asphalt composition.