Shingle roofing coating method and composition
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current shingle roofing coatings face challenges in meeting ASTM 3462 specifications for softening point and penetration, often resulting in brittleness, staining, and increased viscosity, which affects performance under varying temperatures and weather conditions, and there is a scarcity of special feedstocks that meet these requirements.
Innovation Solution
The method involves oxidizing an asphalt feedstock to achieve a softening point greater than 205°F and penetration less than 15 dmm, followed by mixing an elastomeric polymer and asphalt flux to create a shingle roof coating, with the elastomeric polymer content adjusted based on the feedstock type to ensure 0.5% to 6% by weight, thereby meeting the ASTM 3462 requirements and enhancing stability and adhesion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If air blowing is used to oxidize asphalt to increase softening point, then softening point increases, but penetration drops below target and viscosity increases
Solution Approach 1:
The patent applies parameter changes by carefully controlling oxidation parameters (air flow rate, temperature, time) to achieve the desired softening point increase while maintaining penetration within specification. The process transforms the asphalt parameters through controlled oxidation to reach the target property balance.
Solution Approach 2:
The patent introduces local quality by adding specific components (wax, polymers, resins) at controlled stages during the air blowing process. These additives are introduced at specific locations in the process flow and in controlled amounts to locally modify the asphalt properties without affecting the entire batch uniformly, thereby maintaining penetration while increasing softening point.
2Temperature
If air blowing is used to oxidize asphalt to increase softening point, then softening point increases, but viscosity increases affecting performance
Solution Approach 1:
The patent uses parameter changes to control the oxidation degree and temperature profile during air blowing, optimizing the balance between softening point increase and viscosity control. By adjusting process parameters, the patent achieves the required softening point while minimizing excessive viscosity increase that would affect application performance.
Solution Approach 2:
The patent introduces intermediary substances (wax, polymers, resins) that act as mediators during the oxidation process. These intermediaries help control the viscosity increase by modifying the molecular structure development during oxidation, allowing the asphalt to achieve higher softening point while maintaining workable viscosity levels.
3Manufacturing precision
If penetration is maintained near 15 dmm during oxidation, then penetration specification is met, but softening point may not reach 205°F requirement
Solution Approach 1:
The patent applies preliminary action by pre-heating the asphalt feedstock to specific temperatures before introducing it to the air blowing process. This preliminary heating ensures that the oxidation reactions proceed at optimal temperatures, enabling both penetration and softening point specifications to be met simultaneously through controlled thermal history.
Solution Approach 2:
The patent uses parameter changes by adjusting multiple process variables (temperature, air flow, residence time, additive composition) in a coordinated manner. By changing these parameters systematically, the patent achieves the dual objective of maintaining penetration near 15 dmm while achieving softening point of 205°F or higher.
4Temperature
If oxidation is extended to increase softening point, then softening point increases, but brittleness increases
Solution Approach 1:
The patent introduces intermediary substances (wax, polymers, resins) that act as flexibility agents during the oxidation process. These intermediaries prevent excessive cross-linking and molecular aggregation that would cause brittleness, thereby allowing extended oxidation to achieve higher softening points while maintaining flexibility and reducing brittleness.
Solution Approach 2:
The patent applies parameter changes by controlling the oxidation extent through monitored parameters (temperature, time, air flow) and introducing stopping points in the oxidation process. By changing these parameters and adding flexibility-enhancing components at specific stages, the patent achieves high softening point while preventing excessive brittleness development.
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 approach allows the use of a wide range of asphalt types, improves granule adhesion, reduces staining, and increases the shear tear strength of shingle coatings, enabling them to perform effectively over time under diverse weather conditions.
Implementation Method 1
oxidizing an asphalt feedstock to a softening point greater than 205° F. and a penetration less than 15 dmm
Data Source
AI summary
An asphalt composition suitable for use as a shingle roof coating is described. The asphalt composition comprises an oxidized asphalt feedstock and a first concentrate. The oxidized asphalt feedstock has a softening point greater than 205° F. and a penetration of less than 15 dmm. The first concentrate includes an elastomeric polymer and an asphalt flux. The asphalt composition includes 1.5% to 4.5% by weight of the elastomeric polymer.