Shingle Coating Asphalt Composition via Over-blowing and Ester Additive
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Solution Overview
Problem
Conventional methods for producing roofing shingle coating asphalt compositions from paving grade asphalt fail to achieve the necessary properties for roofing applications, such as softening point and penetration values, due to limitations in the air blowing process, requiring costly adjustments to processing machinery and the use of costly additives like solid waxes and catalysts that produce toxic emissions.
Innovation Solution
Over-blowing paving grade asphalt to achieve a penetration value of 15 dmm or below and a softening point of at least 220°F, followed by the addition of a thermally stable ester-based additive, such as modified vegetable oil, to adjust the softening point and penetration value within the desired range for roofing shingles, without the need for expensive machinery updates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If paving grade asphalt is air blown to increase softening point, then thermal stability improves, but penetration value becomes too low and brittleness increases
Solution Approach 1:
The patent applies parameter changes by carefully controlling the air blowing process to achieve a softening point of at least 220°F while maintaining penetration value at 15 dmm or below. This specific parameter range resolves the contradiction between thermal stability and penetration characteristics, creating asphalt suitable for shingle coating applications.
Solution Approach 2:
The patent creates a composite material system by combining over-blown paving grade asphalt with specific additives (polymer-modified asphalts, elastomers, or plasticizers). This composite approach allows the base asphalt to provide thermal stability while the additives restore and enhance penetration properties, eliminating brittleness while maintaining high softening point.
2Reliability
If coating grade asphalt is used as feedstock, then desired roofing properties are achieved, but material cost increases
Solution Approach 1:
The patent transforms low-cost paving grade asphalt into high-performance coating asphalt by changing its parameters through controlled air blowing. The process achieves a softening point of at least 220°F and penetration of 15 dmm or below, converting an unsuitable material into one that meets all roofing application requirements at lower cost.
Solution Approach 2:
The patent uses inexpensive paving grade asphalt as the base feedstock, replacing costly coating grade asphalt. By applying the air blowing process and additive system, the cheap paving asphalt achieves the performance characteristics of expensive coating asphalt, significantly reducing material costs while maintaining reliability.
3Temperature
If wax and catalyst are added to adjust asphalt properties, then softening point increases, but toxic emissions are produced
Solution Approach 1:
The patent uses controlled air blowing (oxidation process) to increase the softening point of paving grade asphalt to at least 220°F. This oxidation method achieves the desired thermal properties without requiring wax or catalyst additives, thereby eliminating toxic emissions associated with those chemicals while still achieving the necessary softening point elevation.
4Temperature
If air blowing process is extended to lower penetration value, then softening point increases, but processing time increases
Solution Approach 1:
The patent applies partial air blowing to achieve the minimum required softening point of 220°F and penetration of 15 dmm or below. By targeting specific parameter thresholds rather than excessive processing, the method achieves the necessary properties efficiently without unnecessary time consumption, optimizing the balance between property development and processing duration.
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 resulting shingle coating asphalt composition is thermally stable at high temperatures, resistant to fallback, and maintains desired properties over extended exposure to heat, with improved durability and stain resistance, while eliminating the need for costly updates to processing equipment and reducing toxic emissions.
Implementation Method 1
air blowing, which is an oxidation process that involves blowing air through molten asphalt to modify the physical properties of the asphalt
Implementation Method 2
The additive may comprise an ester and is included in an amount to achieve a second softening point that is less than about 220° F.
Data Source
AI summary
A shingle coating asphalt composition is provided that is produced from a paving grade asphalt. The shingle coating asphalt composition comprise a paving grade asphalt that has been overblown to achieve a first penetration value that is at or below about 15 dmm and a first softening point that is at least about 210° F. The shingle coating composition may further include an additive that is included in an amount to achieve a second softening point that is less than about 230° F. and a second penetration value that is between about 15 and 20 dmm. The additive may comprise at least one ester. The inventive shingle coating asphalt composition may be thermally stable at processing temperatures of at least 450° F.