WO1997035940A1

WO1997035940A1 - Method for controlling low temperature performance of asphaltic compositions

Info

Publication number: WO1997035940A1
Application number: PCT/US1997/004874
Authority: WO
Inventors: David R. Jones, Iv; Kenneth F. Grzybowski
Original assignee: Pri Asphalt Technologies, Inc.
Priority date: 1996-03-27
Filing date: 1997-03-26
Publication date: 1997-10-02

Abstract

A method for using a glyceride or vegetable oil to control, manage or otherwise improve the low temperature performance of an asphaltic composition through incorporation of a predetermined amount of such a glyceride or oil into the composition.

Description

METHOD FOR CONTROLLING LOW TEMPERATURE PERFORMANCE OF ASPHALTIC COMPOSITIONS

Background of the Invention.

The present invention relates generally to the improved low temperature performance of asphaltic compositions and methods for controlling, managing or otherwise altering the low temperature performance properties of such compositions through use and/or measured incorporation of vegetable oil.

The performance required of any asphalt material is determined by its end use and/or application and is gauged by one or more measurable properties. For illustrative purposes, asphalt materials used in the roofing context must be designed to perform several somewhat diverse functions. In order to saturate and impregnate an organic or comparable base material a roofing asphalt must be very fluid at processing temperatures. Once applied as part of a roofing material—including shingles, coll roofing, underlayments and various membranes—the asphalt should also retain its durability and/or weather resistance over a wide temperature range and low temperature extremes.

Asphalt pavements are also illustrative. The asphalt materials used therewith must possess properties which facilitate application. Lighter, less viscous fractions may be blended with high viscosity asphalts to achieve lower grades. Another approach is to incorporate the asphalt component as part of a cold-applied system, which can take the form of one of various cutback solvent and aqueous emulsion compositions. Once applied, the asphalt can be implicated in a number of common roadway failures. Asphalts can be especially susceptible to aging, prone to raveling and are relatively inflexible at low temperatures such that cracking and deformation occur over time.

Notwithstanding the availability of various processing techniques and incorporation of additives or modifiers, satisfactory low-temperature asphalt performance remains an elusive goal for pavement, roofing and industrial applications. There is a need for a cost-effective method to control and/or O 97/35940 PC17US97/04874

2 manage such low-temperature performance properties and/or physical characteristics, thereby providing an accessible route toward improved low-temperature asphaltic pavements, roofing materials, and industrial coatings.

Various efforts have been undertaken but have not resulted in or have been observed to in any way modify and/or improve the low temperature performance of an asphaltic composition. For instance, as described in United States Patent Application No. 5, 164,002, a vegetable oil was employed in conjunction with a citrus terpene and silicone oil, but only to improve the anti-stripping properties of an asphalt/aggregate composition and prevent pavement water damage. Other efforts have shown that the vegetable oil can be used beneficially in conjunction with a polymeric fiber to decrease high temperature flow and deformation of an asphaltic pavement. However, because the presence of a fibrous component does not generally have a significant impact on low temperature pavement performance, incoφoration of a vegetable oil therein would not be expected to provide a low-temperature benefit. Summary of the Invention.

There are a considerable number of problems and deficiencies associated with asphalt compositions, as used in the construction/building industry— irrespective of the particular asphalt or modification technique employed. There is a demonstrated need for a methodology toward asphaltic materials and/or compositions having modified and/or enhanced performance properties at low temperatures, which can be prepared in a manner so as to design a particular material or composition with control and management of low temperature properties.

Accordingly, it is an object of the present invention to provide asphalt compositions having modified performance properties and method(s) for their preparation, thereby overcoming various deficiencies and short comings of the O 97/35940 PC17US97/04874

3 prior art, including those outlined above. It will be understood by those skilled in the art that one or more aspects of this invention can meet certain objectives, while one or more other aspects can meet certain other objectives. Each objective may not apply equally, in all instances, to every aspect of the present invention. As such, the following objects~in light of the prior art regarding asphalt compositions—can be viewed in the alternative with respect to any one aspect of the present invention.

It can also be an object of the present invention to provide a glyceride and/or vegetable oil material and method(s) for use or predetermined, measured incorporation thereof into an asphalt or a polymer/fiber-modified asphalt composition to modify one or more of the asphalt or polymer/fiber properties and improve or control various low temperature performance properties.

Other objects, features and advantages of the present invention will be apparent from the foUowing summary of the invention and description of preferred embodiments, and will be readily apparent to those skilled in the art having knowledge of various asphaltic compositions, whether modified with fiber or filler, and the requirements for use of such compositions in the building and construction industry, in particular, for use as coating and/or roofing or industrial and binder and/or pavement materials. Such objects, features, benefits and advantages will be apparent from the above as taken in conjunction with the accompanying examples, tables, data, and all reasonable inferences to be drawn therefrom.

In part, the present invention is a method of controlling the low temperature performance of an asphaltic cement binder having dispersed therein a vegetable oil. The low temperature performance of the binder is controlled by the weight percentage of the vegetable oil in and/or added to the binder. Vegetable oils useful in conjunction with this method include, without limitation, corn, peanut, sunflower, soybean, rapeseed, cottonseed, linseed, coconut, olive, rung, palm, perilla, oiticia, and combinations thereof, whether any such oil is unprocessed or further refined. In preferred embodiments of this aspect of the invention, the vegetable oil is about 0.1 to about 10.0 weight percent of the cement binder, and/or has a flash point greater than 230°C using

Cleveland Open Cup test procedures and apparatus, as described more fully in

American Society for Testing and Materials (ASTM) Standard Test Method

D 92, the entirety of which is incorporated herein by reference. Regardless, such a vegetable oil is used with a binder having an asphaltic component from the group consisting of a naturally-occurring asphalt, a by-product of refined crude oil, an asphalt cutback, an asphalt emulsion, an asphaltite and a combination thereof.

In highly preferred embodiments the vegetable oil is corn oil, peanut oil, sunflower oil, soybean oil or a combination of such oils. Without limitation, excellent control over low temperature performance can be achieved with an appropriate binder where the vegetable oil is about 1.0 to about 6.0 weight percent and is at least, partially, sunflower oil.

In part, the present inventions is a method of using a vegetable oil to reduce the low-temperature cracking of a hot-mix asphaltic pavement. The inventive method includes (1) providing a liquidic asphaltic cement binder, and (2) mixing with the binder a vegetable oil in an amount sufficient to decrease the stiffness parameter of the binder at low temperatures. In preferred embodiments, the vegetable oil is at least one of the oils described above and present at about 0.1 to about 10.0 weight percent of the binder component of the pavement. The oil concentration can be adjusted in a straight-forward manner without undue experimentation to provide a binder and resulting pavement with a sufficiently decreased stiffness parameter and resistance to low-temperature cracking, respectively. Alternatively, the vegetable oil when used in an amount sufficient to reduce stiffness and/or low-temperature cracking, will have a mass loss of less than about 1.0 weight percent under Rolling Thin-Film Oven Test conditions, as more fully described in ASTM Standard Test Method D 2872, the entirety of which is incoφorated. In highly preferred embodiments, the vegetable oil is present at a concentration of about 1.0 to about 6.0 weight percent as compared to the cement binder, and can be either corn oil, peanut oil, sunflower oil, soybean oil or a combination thereof.

Whether for the control of low temperature performance of a cement binder, as described above, or for reduction of low-temperature cracking of a hot-mix pavement, the methods of this invention contemplate incoφoration of a polymeric and/or fibrous material, whether virgin or recycled. Fibers include those organic or inorganic, natural or synthetic materials with a high length/diameter ratio. Natural fibers include cellulose and mineral fibers such as fiberglass, rock, wool and asbestos. Synthetic polymeric materials include plastomers, elastomers or combinations thereof. The polymeric material can be present at a concentration of about 0.1 to about 15.0 weight percent of the binder component utilized. Plastomers and elastomers which can be incoφorated with an asphaltic binder can include but are not limited to: styrene-butadiene-styrene co-polymer, styrene-ethylene-butadiene-styrene co-polymer, styrene-butadiene-rubber co-polymer, atactic polypropylene, ethylene-vinylacetate, polyethylene, various epoxidized polyolefins, polyesters, isotactic polypropylene, natural rubbers, nitrile rubbers, chlorinated rubbers, silicone rubbers, polystyrene, polyvinylchloride, various polyacrylates, polycarbonates, polyacetals, and polysulfones.

Regardless of the fibrous/polymeric material incoφorated into the asphalt binder, the material can be added to the binder under conditions facilitating homogenous dispersion. Alternatively, the fibrous/polymeric material and vegetable oil of this invention are blended together before incoφoration with the asphaltic binder. Refer to the examples which follow for both general and specific method parameters. As mentioned above, the binder has a liquidic asphalt component which can be but is not limited to a naturally-occurring asphalt, a by-product of refined crude oil, an asphalt cutback, an asphalt emulsion, an asphaltite or a combination thereof. In prefened fibrous/polymeric embodiments, the binder is about 0.1 to about 35.0 weight percent of a naturally-occurring asphalt, an asphaltite or a combination thereof; and the vegetable oil concentration is about 1.0 to about 6.0 weight percent and the polymeric material has a concentration of about 1.0 to about 6.0 weight percent. In highly preferred embodiments, with such oil and fibrous/polymeric concentrations, the binder is about 5.0 to about 15.0 weight percent of a refined crude oil by-product.

In part, the present invention is a method of improving the mmimum design temperature of a pavement paired with an asphaltic cement binder, with the method including the incoφoration of about 0.1 to about 10.0 weight percent of a glyceride with a liquidic asphaltic binder to modify the performance grade of the binder. In preferred embodiments, the glyceride is a vegetable oil of the sort but not limited to the oils listed above. However, the methods of this invention can be utilized in a similar fashion with various other glycerides, either synthetic or naturally-occurring, having one or more fatty acid moieties with a molecular weight such that they are functionally equivalent to such vegetable oils. In highly preferred embodiments, corn oil, peanut oil, sunflower oil, soybean oil or a combination thereof can be incoφorated to provide a concentration of about 1.0 to about 6.0 weight percent of the asphaltic binder. Various other embodiments, depending upon the particular binder performance grade, pavement, and minimum design temperature required can also include the addition of a fibrous/polymeric material, as more fully described above. In part, the methods of the present invention can be used separately to control the low temperature performance of an asphaltic coating composition of the type which would find utility in a roofing or industrial context. Such compositions, according to this method, have dispersed therein a vegetable oil, whereby the low temperature performance of the coating composition is controlled by the weight percentage of the vegetable oil in the composition. In preferred embodiments, the vegetable oil can be but is not limited to corn oil, peanut oil, sunflower oil, soybean oil, or a combination thereof, at a concentration of about 0.1 to about 30.0 weight percent of the coating composition. Alternatively, the vegetable oil used to control low temperature performance can be defined as a material having a flash point greater than 230°C using Cleveland Open Cup procedures and apparatus, as more fully described in ASTM Standard Test Method D 92. In highly preferred embodiments, the vegetable oil is sunflower oil and/or incoφorated into the coating composition such that the concentration is about 1.0 to about 10.0 weight percent.

As described above, this method can include incoφoration of a fibrous/polymeric material, the nature and identity of which is chosen to meet specific physical and/or performance properties. Such materials can be incoφorated at a concentration of about 0.1 to about 30.0 weight percent and, as described above, can include natural fibers, plastomers, elastomers, or combinations thereof. Where a polymeric/fibrous material is also incoφorated the concentration can be about 3.0 to about 15.0 percent by weight depending upon the nature and identity of the fibrous/polymeric material and the end use envisioned for the coating composition. Under such conditions, the vegetable oil component is preferably about 1.0 to about 10.0 weight percent, such that the concentration and addition thereof controls the low temperature of the coating composition. O 97/35940 PC17US97/04874

8

As discussed more thoroughly below, such coating compositions can further include a filler material to impart and/or affect various performance and physical properties. The amount of filler material can vary depending upon end use and application, but can be present at a concentration of about 10.0 to about 70.0 weight percent, with the vegetable oil present in an amount sufficient to counteract and/or improve low temperature performance through reduction of asphalt stiffness at such low temperatures.

As mentioned above, an asphaltic material utilized in accordance with the method(s) and resulting compositions of this invention can be derived from any one of a number of refined crude oils, naturally occurring asphalts, asphaltites such as gilsonite and combinations thereof. Included vvithin the broad category of refined crude oils are various recycled asphaltic waste materials, including but not limited to those waste materials and components thereof described in columns 4-8 of U.S. Patent No. 5,217,530, which is incoφorated herein by reference in its entirety. More particularly, the asphalt material can be but is not restricted to (1) a cementitious asphalt having physical properties meeting or equivalent to ASTM D 3381 standard specifications for use in pavement construction, (2) a cementitious asphalt having physical properties meeting or equivalent to ASTM D 946 standard specifications for use of such an asphalt in pavement construction, (3) a roofing asphalt having physical properties meeting or equivalent to ASTM D 312 standard specifications for use of such an asphalt in built-up roof construction, or (4) an asphalt having physical properties meeting or equivalent to ASTM D 449 standard specifications for use in damp-and wateφroofing. These ASTM standard specifications are well-known to those skilled in the art and incoφorated by reference herein in their entity.

While various physical properties are described in the context of recognized ASTM standards, comparable and/or equivalent standards and specifications can also be used to describe the asphaltic component, including but not limited to such standards as recognized in Germany, the United Kingdom, Italy, Canada, and countries of the Far East including Japan and the People's Republic of China. Likewise, the compositions available/producible through implementation of the method(s) of the present invention can optionally have physical properties meeting or equivalent to those specified in the respective ASTM standards.

It should be understood and as is apparent from the examples, tables and data which follow that the asphalt element/component of method(s) and/or compositions of this invention is not limited to any one type or grade specified in the latest revision of the aforementioned ASTM standards and/or any previous version thereof. Preferred embodiments include specified types and/or grades where improved performance properties are desired. With equal utility, however, the asphaltic components can have physical properties either within or outside the ASTM standards. As referenced in each of the aforementioned ASTM standards and as well-known to those skilled in the art, asphalt specified under each standard is prepared from commercially-available or raw materials by known methods. The same can be used with the present invention, with the resulting compositions having the physical properties of a specific ASTM type or grade.

Nonetheless, the compositions and/or methods of the present invention can suitably comprise, consist of, or consist essentially of elements and/or components involving asphalts, asphaltites, asphaltic emulsions or cutbacks, glycerides, vegetable oils and the synthetic equivalent thereof. Each such composition and/or method is distinguishable, characteristically contrasted, and can be practiced in conjunction with the present invention separate and apart from another. Accordingly, it should be understood that the inventive compositions and/or methods, as illustratively disclosed herein, can be prepared O 97/35940 PC17US97/04874

10 and/or practiced in the absence of any one component, species and/or step which may or may not be specifically disclosed, referenced or infened herein, the absence of which may or may not specifically disclosed, referenced or infened herein.

The glyceride and/or vegetable oil of this invention can be used effectively over the weight percent range described above. At amounts less than the lower end of the referenced range, the enhancement of various low temperature performance properties of the resulting compositions—including reduced stiffness— tends to fall below levels which may be sufficient and/or cost-productive. At concentrations of glyceride/oil beyond the referenced range, effective interaction with an asphalt or fibrous component may become problematic as increasing concentrations can adversely affect high temperature performance and tend to outweigh low temperature benefits. As is applicable to other aspects of this invention, various time, temperature and mix parameters, as recognized by those of skill in the art, can be used and/or modified with a given asphaltic or glyceride/oil component or concentration to achieve a desired, predetermined performance property.

The glyceride and/or vegetable oil of this invention would not seem appropriate for use in an asphaltic composition for the puφose of modifying low temperature performance properties. It would seem improbable that these materials could be used effectively at any concentration for any puφose but to improve anti-strip and high temperature flow properties of polymer-modified systems. It would also seem improbable that such materials would provide asphaltic compositions, in particular those for use in pavement or roofing, with the low temperature properties observed. As such, the use of such materials in the manner disclosed herein is contrary to the art. The enhanced physical and engineering performance properties obtained were suφrising and quite unexpected and represent a substantial improvement over the prior art. As mentioned above, various embodiments of the present invention can also contain at least about 0.1 percent by weight of a polymeric/fibrous material, of the type but not limited to an elastomer, a plastomer or a combination of one or more elastomers and plastomers. A useful polymer concentration is a factor of the degree of enhancement of various desired performance properties in combination with the particular glyceride/oil or amount used. In a general sense, elastomers can be defined as those polymeric materials extendable under low stress without rupture and exhibiting elastic properties upon stress removal. Likewise, in a general sense, plastomers can be defined as polymeric materials of the type which, under stress conditions, can deform without rupture.

The monomeric percentage of any polymer— block or otherwise—can vary from system to system, depending upon commercial availability, desired properties, and end use or application. By way of example and without limitation, a styrene-butadiene-styrene co-polymer can contain about 30 weight percent styrene, while an ethylene-vinylacetate system can contain about 30-40 weight percent vinylacetate. Other physical properties, such as molecular weight and structure/moφhology can be chosen, in accordance with this invention, to meet the low temperature performance properties or requirements of a particular asphaltic composition.

While standard specifications for polymer-modified asphaltic compositions are proposed, various properties are widely-recognized as indicative of performance, including those properties assessed in the examples which follow herein. The protocols for most evaluations can be found in or derived from the ASTM D 5147 test method standard, which is incoφorated herein by reference in its entirety.

Various embodiments of the present invention can also include a filler material. Fillers can be used as bulking agents, in concentrations as needed, to thicken and/or stabilize an asphaltic composition after application, as well as to impart various texture and anti-skid properties—especially so in the pavement context. As distinguished from aggregate materials, fillers are typically size-graded below 40-60 mesh. In particular, without limitation, useful filler materials can include sand, mica, ground slate, diatomaceous earth, and ground limestone, or their compositional components. Such a filler material can be co-incoφorated with an elastomer, plastomer or a combination thereof, in the manner of and at concentrations as described herein.

As mentioned above, polymeric/fibrous additives can be used with this invention in a variety of pavement contexts, including but not limited to wateφroofing membranes and binders for surface dressings, mastic asphalt and asphalt concrete. When incoφorated into such binders and/or pavements, the oils/glycerides of this invention provide a more flexible, less stiff system by modifying either one or both of the asphalt and fiber components. The relative concentration of the oil/glyceride is as described above and determined by the performance/physical properties desired and anticipated end use or application.

For instance, the present invention can be used to prepare a hot mix pavement including an aggregate component and either a plastomer or an elastomer. Such compositions can also be prepared with a filler material. Invariably, however, the stiffening effects of the filler negate the properties imparted by the plastomer or elastomer chosen. This is observed most dramatically at lower temperatures and can be countered through use of a glyceride/oil in a measured fashion to control and improve low temperature performance. The examples below further illustrate this benefit.

The glycerides/oils of this invention can also be used with polymeric systems to modify asphaltic compositions and/or roofing materials. The resulting elastomeric and plastomeric compositions can be used in conjunction with coatings and other roofing products and can be applied/installed using techniques completely analogous to those for conventional polymer/modified materials. For example, an asphaltic material modified through use of the present invention can be torch-applied over a base sheet. Alternatively and for puφoses of example only, an asphalt modified using the present invention can be hot-mopped over a suitable base sheet. Likewise, without limiting the present invention, a self-adhering styrene-butadiene-styrene modified membrane prepared in accordance with the present method(s) can be applied over a base sheet or a suitable insulation layer. Without exception, the polymer- and/or glyceride/oil-modified compositions available through this invention can be utilized in any manner useful with conventional modified materials, allowing for changes in physical properties and/or characteristics induced by incoφoration of the glyceride/oil of this invention. Likewise and without exception, measured incoφoration of such a glyceride and/or oil can be used to control, manage and/or improve the low-temperature performance of any such composition.

Preferably, at the process and/or mix temperature chosen, the asphaltic component has sufficient fluid characteristics to permit facile and homogeneous incoφoration of a vegetable oil and whatever additional filler, fiber or polymeric component desired. At higher temperatures, the material can be sufficiently fluid. However, such characteristics can also be imparted by either mixing the asphalt with a suitable solvent to form a cutback solution or forming an emulsion with water.

Compositions prepared in this manner and according to this invention are designed to be employed without an external source of heat over a wide range of weather and application conditions, while still meeting specific performance standards. In addition to the components described above, various other materials can be incoφorated into the solution or emulsion to achieve and/or improve one or more performance characteristics: pigments and various miscellaneous chemical additives, including dispersants and surfactants, among others. Regardless, incoφoration of a glyceride/oil can be used to control and/or improve low-temperature performance.

The asphalt cutback materials which can be used in conjunction with the methods of the present invention can be of the medium-cure, rapid-cure, or slow-cure varieties, with the solvent selected to control the cure rate of the resulting asphalt composition. Suitable cutback solutions can be purchased pre-blended from sources well-known to those skilled in the art. Alternatively, without limitation, cutback solutions can be prepared from various petroleum asphalts upon solution with commercially-available solvents such as but not limited to Rule and Non-Rule 66 mineral spirits, kerosene/No. 2 fuel oil, and the like, as are provided by various well-known suppliers of distillates. Either a neat asphalt or a cutback solution thereof can be used to prepare an aqueous emulsion.

Both cutback solutions and emulsions, when used as part of the present invention, can incoφorate one or more of several clay components, such as the attapulgite, bentonite, and ball varieties, with or without a surfactant, to provide various texture, strength and thixotropic properties which might otherwise be provided through the use of an asbestos material. It should be understood that emulsions of the sort discussed herein include those where clay and asphalt provide the discontinuous phase. Inverted emulsions, with water as the discontinuous phase, are also contemplated. Likewise, as mentioned above, various cutback emulsions, prepared from an asphalt/solvent slurry emulsified in water, can also be used— with either the water or slurry components as the discontinuous phase. Again, such compositions can be controlled with respect to their low temperature performance through use and/or incoφoration of the glycerides/oils described above. Examples of the Invention.

The following non-limiting examples and data illustrate various aspects and features relating to the method(s) and resulting compositions of this invention, including the suφrising and unexpected modification, control and/or improvement of low temperature performance through use/incoφoration of the inventive glycerides and/or vegetable oils.

As illustrated with representative examples of the inventive methods, the low temperature performance of an asphaltic cement binder or coating material can be controlled by use of and the weight percent of a vegetable oil and/or glyceride incoφorated therein. The examples also illustrate how the performance grade of an asphaltic binder can be modified through use of this invention to provide a pavement with an improved minimum design temperature.

As discussed above, the glycerides and/or oil of this invention can be used effectively over the weight percent range provided. The examples below are illustrative in this regard, to the extent that the methods described and compositions prepared can be extended to include higher or lower concentrations of glyceride/oil with a conesponding modification of low temperature performance.

Example 1

The asphaltic component is heated until liquid, typically at a temperature between 250° and 350°F. An amount of the vegetable oil/glyceride sufficient to control and/or attain a given low temperature performance parameter is added to the asphaltic component with stirring, using the equipment and techniques described above or those otherwise available to individuals skilled in the art. With a sufficiently liquid asphaltic component, either through application of heat or incoφoration of the asphalt in a cutback solution or an aqueous emulsion, a sufficiently homogeneous mixture is provided and improved performance is available with minimal stirring.

Example 2

The methods of the present invention also contemplate inclusion of a fibrous and or polymeric component with any of the binder, coating, or pavement compositions described above. Such compositions can be prepared by dispersing, for instance, a polymer-whether plastomeric and/or elastomeric— throughout the asphaltic component using either high shear mixing (for high melting point materials such as styrene- butadiene-styrene or polyethylene) or low shear mixing (for lower melting point polymeric materials such as atactic polypropylene or ethylene-vinylacetate). As described in the previous example, the asphaltic component is preferably provided as a liquid. After a homogeneous blend of fibrous/polymeric and asphaltic components is achieved, the oil/glyceride of this invention is incoφorated as described above. Example 3 a

Alternatively, where the method of this invention includes incoφoration of a fibrous and/or polymeric component, a vegetable oil and/or glyceride is pre-mixed with the polymeric component at room temperature with a gentle mixing. Over the course of several hours and in contact with the oil/glyceride, the fibrous and/or polymeric material softens and swells. The oil/glyceride blend is then incrementally incoφorated with a liquid asphalt, as provided above, with either high or low shear mixing to obtain a sufficiently homogeneous mixture. For those applications where the liquid asphalt is achieved through application of heat, temperatures must be below those which would otherwise degrade the fibrous/polymeric component.

Example 3 b

Extending the method of Example 3 a, a polymeric/fibrous component can also be incoφorated by way of a cutback solution or an aqueous emulsion. While the pre-mix of 3 a can be broadly described as a cutback, other organic solvents compatible with the asphaltic material can also be used. An aqueous emulsion of such a polymeric/fibrous component, i.e., a latex rubber emulsion, can optionally include a suitable surface active agent. Regardless of how the polymer/fiber is incoφorated, the vegetable oil/glyceride of this invention can in a similar manner be used neat or as an aqueous emulsion, and optionally pre-mixed with the polymer/fiber component or added sequentially therewith to a liquid asphalt material. Use of the oil/glyceride and/or polymeric/fibrous components in this manner reduces mix times, can ease handling and process concerns and facilitates control over low temperature performance. Example 4a

As a point for comparison, a Venezuelan asphalt, with a modulus of 1.76 kPa at 64°C, has its modulus increased to 3.92 kPa at 64° with the addition of 1.8 wt% of cellulose fibers. However, the low temperature stiffness of the asphalt at -18°C only changes from 308,000 kPa to 319,000 kPa with the addition of 1.8% cellulose fibers, an insignificant increase in stiffness relevant to the performance of the binder.

Example 4b

In contrast to Example 4a above, the addition of fillers such as lime stiffens both the low and high temperature values, neither of which is beneficial to the asphalt performance. The Venezuelan asphalt of Example 4a, when modified with 40 wt% lime has its stiffness at 64° increase from 1.76 to 15.12 kPa. At -18°, the stiffness also increases significantly, from 308,000 to 1,028,000 kPa. The very large increase in stiffness at -18° is deleterious to the performance of the asphalt.

Using the methods of this invention, the low temperature performance of this binder can be controlled. Increasing the concentration of, for example, linseed oil incoφorated into the liquidic asphalt up to about 4 weight percent will conespondingly decrease low temperature stiffness to a point where binder performance is not significantly affected by the inclusion of filler. Continued addition of an inventive oil/glyceride will further decrease low temperate stiffness and improved related performance parameters. Example 4c

The asphalt of Examples 4a-b cited above, when modified with 40 wt% limestone has its stiffness at 64° increase from 1.76 to 4.60 kPa. At -18° the stiffness increases from 308,000 to 678,000 kPa. The large increase in stiffness at -18° is deleterious to the performance of the asphalt.

Likewise in accordance with the methods of this invention, low temperature binder performance can be controlled and the low temperature cracking of a resulting hot-mix pavement can be reduced. An oil/glyceride of this invention can be incoφorated into the binder in an amount sufficient to decrease low temperature stiffness and/or reduce low temperature cracking of the prepared pavement. The amount required will be determinable by those skilled in the art and aware of this invention.

Example 5 The methods of this invention can be further demonstrated by analysis of various asphaltic compositions of the type used in hot mix asphalt concrete pavements. Low temperature cracking (LTC) is one characteristic indicative of pavement performance. To assess LTC and with reference to Tables a-c, stiffness S is determined through bending beam rheometer (BBR) testing, and m is the slope of the plot of log (stiffness) versus log (time). Stiffness is measured from 0-1500 megaPascals (MPa), and m is dimensionless with values from 0.10-0.50. With reference to Table d, the Strategic Highway Research Program (SHRP) binder specification has been issued by the American Association of State Highway Transportation Officials (AASHTO) as specification MP-1, the entirety of which is incoφorated herein by reference. The low temperature benefits afforded through the methods of this invention can also be demonstrated through comparison of SHRP binder performance grades (PG). An SHRP PG gives the maximum and minimum pavement temperature (°C) under which the asphaltic binder component of the pavement can be expected to perform. For instance, an asphalt of PG 64-28 would be expected to perform in a manner consistent with specification MP- 1 at a high pavement temperature of 64°C and a low temperature of -28°C.

The data of Tables a-d were compiled from the tests of materials prepared from representative and commercially-available asphalts (Husky, Marathon, Imperial, Jebro and Clark, etc.) having the shown penetration (pen) or AC designations, representative and commercially available fibrous/polymeric modifiers (Kraton 1 101, etc.) and commercially-available vegetable oils also representative of the oils which can be utilized with this invention. The asphalts/mixes were, in each instance, prepared in accordance with this invention and as described herein.

Table a

Asphalt/mix BBR (a), -36°C test temperature

Stiffness, S(MPa) slope, m

Husky 200-300 pen 1400 0.160

Husky w/ 2 wt. % SO 788 0.256

Husky w/ 4 wt. % SO 563 0.281

Husky w/ 6 wt. % SO 371 0.328

Incoφoration of sunflower oil (SO), a representative vegetable oil of this inventions, shows lowered stiffness and increased m parameters, evidencing improved and controlled low temperature performance. Table b

Asphalt/mix BBR (3⁾, -30°C test temperature

Stiffness, S(MPa) slope, π

Imperial 200-300 pen 557 0.266

Imperial w/ 3 wt. % Kraton 337 0.273

1 101, 2 wt. % SO

Imperial w/ 3 wt. % Kraton 288 0.320

1101, 3 wt. % SO

Imperial w/ 2 wt. % Kraton 372 0.304

1 101, 2 wt. % SO

Imperial w/ 4 wt. % Kraton 304 0.290

1101, 3 wt. % SO

Again, measured incoφoration of a vegetable oil (e.g., sunflower oil) can be used to control low temperature performance and reduce low temperature cracking. The data show that the lowered stiffness and increased m parameters are driven by the weight percentage of the oil and not the presence of the polymeric/fibrous modifier— for instance, styrene-butadiene-styrene (SBS).

Table c

Asphalt/mix BBR (a), -30°C test temperature

Stiffness, S(MPa) slope, m

Husky 300-400 pen 295 0.315

Husky w/ 4 wt. % SBR 282 0.354

Husky w/ 4 wt. % SBR, 261 0.405

1 wt. % SO

Husky w/ 7 wt. % SB 386 0.252

Husky w/ 7 wt. % SB, 114 0.341

2 wt. % SO

Husky w/ 4 wt. % SBS 317 0.297

Husky w/ 4 wt.% SBS, 309 0.342

0.5 wt. % SO The methods of this invention are further demonstrated through use of sunflower oil (SO) with other modifiers such as styrene-butadiene (SB) and styrene-butadiene-rubber (SBR). The data of Table lb are extended to show the low temperature benefits available at higher polymer/fiber concentrations.

Table d

Asphalt SHRP PG Grade

Marathon AC-5 52-28

Marathon AC-5 w/ 3 wt. % SBR 58-28

Marathon AC-5 w/ 3 wt. % 58-34

SBR, 3 wt. % SO

Jebro AC- 10 58-22

Jebro AC- 10 w/ 4 wt. % SBR 70-22

Jebro AC- 70-28

10 w/ 4 wt. % SBR, 2 wt. % SO

Clark AC-5 58-22

Clark AC-5 w/ 3 wt. % SBR 64-22

Clark AC-5 w/ 3 wt. % SBR, 58-28

2 wt. % SO

As evidenced by the above mixes/compositions, measured incoφoration of an oil/glyceride (e.g., sunflower oil— SO) can be used to control/modify low temperature performance of a binder and the minimum design temperature of (PG) of a resulting pavement— compare -28°C versus -34°C and -22°C versus -28°C.

The following examples further illustrate use of the method of this invention in the preparation of asphalt, asphalt cutback and asphalt/aqueous emulsion compositions of the type which can be used in a pavement, roofing and/or industrial context. Cutback-A is a standard industry designation for a cutback comprising AC-20 asphalt (about 70-72 weight percent), and NON-RULE 66 mineral spirits (about 28-30 weight percent), having a viscosity of 15-25 stormer seconds (propeller plus 100 gms). Cutback-B comprises type III asphalt (about 62-65 weight percent), and NON-RULE 66 mineral spirits (about 35-38 weight percent), having a viscosity of 25-30 stormer seconds (propeller plus 100 gms). By industry designation, SS-lh emulsion comprises AC-20 asphalt (about 63-67 weight percent), water (about 33-37 weight percent), and anionic emulsifying agents (about 0.4-0.7 weight percent), in accordance with ASTM D 977 standard specifications.

Example 6

Asphalt Cutback - A 85.5 weight percent Silica Sand 1.0 weight percent

Corn Oil 1.0 weight percent

Asbestos Fiber 12.5 weight percent

The composition of this example is a brushable asbestos-containing roof coating, designed to conform with ASTM D 2823 standard specifications. The corn oil is added in accordance with this invention to control low temperature performance parameters, such as pliability at 0°C.

Example 7

Asphalt Cutback - B 55.0 weight percent Mineral Spirits 23.0 weight percent Peanut Oil 2.5 weight percent Leafing Grade Aluminum Paste 15.0 weight percent Filler 2.5 weight percent Desiccant 1.0 weight percent

Asbestos Fiber 1.0 weight percent The formula of this example shows use of peanut oil in an asbestos- fibered aluminum roof coating, designed to exhibit low temperature properties in accordance with this invention and with ASTM D 2824, Type III.

Example 8

Asphalt Cutback - A 68.0 weight percent

Soybean Oil 15.8 weight percent

Surfactant 0.7 weight percent

Clay 6.0 weight percent

Cellulose Fiber 3.0 weight percent

Limestone 6.5 weight percent

This formulation shows use of a representative vegetable oil in an asbestos-free roofing cement, designed to have a trowelable consistency in accordance with ASTM D 4586 standard specifications. The surfactant can be a commercially-available product, such as a fatty amine or derivative thereof. The clay can be an attapulgite, such as that available under the Attagel 36 tradename from Englehard Coφoration. Incoφoration of the oil component as described herein can reduce material failure at lower temperatures.

Example 9

Asphalt, Type II 55.0 weight percent

Sunflower Oil 15.0 weight percent

Surfactant 0.2 weight percent

Clay 2.0 weight percent

Polypropylene 22.8 weight percent

Limestone 5.0 weight percent The composition of this example is indicative of how the present method can be employed to provide an asbestos-free synthetic fibered roof coating with a brushable consistency and designed to meet the low temperature (pliability at 0°C) requirements of ASTM D 4479.

Example 10

Cottonseed Oil 22.0 weight percent Leafing Grade Aluminum Paste 15.0 weight percent Asphalt, Type III 50.0 weight percent Desiccant 0.6 weight percent

Limestone 2.4 weight percent

SBS 10.0 weight percent

This example shows a formula for an asbestos-free synthetic fibered aluminum roof coating. This formulation is designed to meet the requirements of ASTM D 2824, Type III, and exhibit improved reflectance and weathering properties.

Example 11

Asphalt Cutback - B 85.0 weight percent Coconut Oil 7.6 weight percent

Surfactant 0.6 weight percent

Clay 4.8 weight percent

Ethylene/vinylacetate 2.0 weight percent

The composition of this example is an asbestos-free synthetic fibered lap cement. The method of this invention can be used to prepare such a composition in conformance with the standard specifications under ASTM S 3019, Type III. Example 12

Asphalt Emulsion - SS-lh 64.8 weight percent Palm Oil 15.8 weight percent Water 16.2 weight percent Surfactant 0.2 weight percent

Clay - Ball Type 2.8 weight percent

Biocides 0.2 weight percent

This composition is designed to be a non-specification controlled crack filler, formulated to be poured easily, and to have good cured and low temperature properties, including reduced shrinkage and cracking.

Example 13

Example 9 99.4 weight percent

Wet Surface Adhesion Additive 0.6 weight percent

This composition illustrates use of the inventive method with a wet surface adhesion agent to provide an asbestos-free roofing cement for adhesion to damp, wet. or underwater surfaces, consistent with the requirements ASTM D 3409.

Example 14

Asphalt - AC-10 76.0 weight percent Corn Oil 3.0 weight percent

Filler - Ball Clay 18.8 weight percent Cellulose 2.4 weight percent

This formulation provides a composition in compliance with Federal Specification SS-S-210, (sealing compound, preformed plastic) for expansion and pipe joints. Absent solvent, this composition can be prepared in accordance with the present invention, preheated at 340°-360°F, and cold- applied in a manner similar to a preformed chalk to give good performance at low temperatures.

While the principles of this invention have been described in connection with specific embodiments, it should be understood clearly that these descriptions, along with the chosen tables and data therein, are made only by way of example and are not intended to limit the scope of this invention, in any manner. For example, the compositions can be prepared using an asphaltic component having characteristics and originating from sources other than those described above. The performance properties modified are not limited to those disclosed. While numerous SHRP and AASHTO procedures/specifications have been mentioned, the methods described have equal applicability with respect to the performance requirements of the conesponding foreign international standards, including those of Canada, the European Community, Japan and the People's Republic of China. It should be understood that the data presented is only representative of the benefits and advantages which can be realized through the use of such compositions. Likewise, while certain compositions can be prepared with reference to a specific method embodiment or specific process parameters—including temperature and component concentrations-it is understood that such parameters and others infened from this description can be readily changed for the puφose of optimizing one or more of the various low temperature performance properties. For instance, the asphaltic compositions described herein can be prepared using either batch or continuous methods. The asphaltic compositions are not limited to any specific polymeric system, but can incoφorate any previously-used polymer— with due consideration given to molecular weight, blend, structure/moφhology, and end use. Other advantages and features of the invention will become apparent from the following claims, with the scope thereof determined by the reasonable equivalents, as understood by those skilled in the art.

Claims

In the Claims:

1. A method of controlling the low temperature performance of an asphaltic cement binder having dispersed therein a vegetable oil, the low temperature performance of said binder being controlled by the weight percentage of said vegetable oil in said binder.

2. The method of Claim 1 wherein said vegetable oil is about 0.1 to about 10.0 weight percent.

3. The method of Claim 2 wherein said vegetable oil is corn oil, peanut oil, sunflower oil, soybean oil or a combination thereof, and present at about 1.0 to about 6.0 weight percent.

4. The method of Claim 1 wherein said vegetable oil has a flash point greater than 230°C using Cleveland Open Cup test procedures and apparatus.

5. The method of Claim 1 wherein said binder has an asphaltic component selected from the group consisting of a natiually-occurring asphalt, a by-product of refined crude oil, an asphalt cutback, an asphalt emulsion, an asphaltite and a combination thereof.

6. A method of using a vegetable oil to reduce low-temperature cracking of a hot-mix asphaltic pavement, comprising: providing a liquidic asphaltic cement binder; and mixing with said binder a vegetable oil in an amount sufficient to decrease the stiffness of said binder at low temperatures.

7. The method of Claim 6 wherein said vegetable oil is about 0.1 to about 10.0 weight percent.

8. The method of Claim 7 wherein said vegetable oil is corn oil, peanut oil, sunflower oil, soybean oil or a combination thereof, and present at about 1.0 to about 6.0 weight percent.

9. The method of Claim 6 wherein said vegetable oil has a mass loss of less than about 1.0 weight percent under Rolling Thin-Film Oven test conditions.

10. The method of Claim 6 further including incoφorating with said binder about 0.1 to about 15.0 weight percent of a polymeric material selected from the group consisting of plastomers, elastomers or combinations of plastomers and elastomers.

11. The method of Claim 10 wherein said polymeric material is added to said binder.

12. The method of Claim 10 wherein said polymeric material and said vegetable oil are blended together before addition to said binder, and at least one of said polymeric material and said vegetable oil is neat, a cutback or an emulsion.

13. The method of Claim 10 wherein said binder has a liquidic asphalt component selected from the group consisting of a naturally-occumng asphalt, a by-product of refined crude oil, an asphalt cutback, an asphalt emulsion, an asphaltite and a combination thereof.

14. The method of Claim 13 wherein said binder is about 0.1 to about 35.0 weight percent of a naturally-occurring asphalt, an asphaltite or a combination thereof.

15. The method of Claim 13 wherein said vegetable oil is about 1.0 to about 6.0 weight percent and said polymeric material is about 1.0 to about 6.0 weight percent.

16. The method of Claim 15 wherein said binder is about 5.0 to about 15.0 weight percent of a refined crude oil by-product.

17. A method of improving the minimum design temperature of a pavement prepared with an asphaltic cement binder, said method comprising the incoφoration of about 0.1 to about 10.0 weight percent of a glyceride with a liquidic asphaltic binder to modify the performance grade of said binder.

18. The method of Claim 17 wherein said glyceride is a vegetable oil.

19. The method of Claim 18 wherein said vegetable oil is corn oil, peanut oil, sunflower oil, soybean oil or a combination thereof, and is present at about 1.0 to about 6.0 weight percent.

20. The method of Claim 17 further including adding to said binder about 0.1 to about 15.0 weight percent of a polymeric material selected from the group consisting of plastomers, elastomers or combinations of plastomers and elastomers.

21. The method of Claim 20 wherein said polymeric material and said vegetable oil are blended together before addition to said binder, and at least one of said polymeric material and said vegetable oil is neat, a cutback or an emulsion.

22. The method of Claim 20 wherein said vegetable oil is about 1.0 to about 6.0 weight percent and said polymeric material is about 1.0 to about 6.0 weight percent.

23. A method of controlling the low temperature performance of an asphaltic coating composition having dispersed therein a vegetable oil, the low temperature performance of said coating composition being controlled by the weight percentage of said vegetable oil in said coating composition.

24. The method of Claim 23 wherein said vegetable oil is about 0.1 to about 30.0 weight percent.

25. The method of Claim 23 wherein said vegetable oil is corn oil, peanut oil, sunflower oil, soybean oil or a combination thereof, and present at about 1.0 to about 10.0 weight percent.

26. The method of Claim 23 wherein said vegetable oil has a flash point greater than 230°C using Cleveland Open Cup procedures and apparatus.

27. The method of Claim 23 further including incoφorating with said coating composition at least one of a polymeric material selected from the group consisting of plastomers, elastomers or combinations of plastomers and elastomers, said polymeric material present at about 0.1 to about 40.0 weight percent, and a filler material present at about 1.0 to about 70.0 weight percent, with said vegetable oil present in an amount sufficient to reduce low temperature asphalt stiffness.

28. The method of Claim 27 wherein said vegetable oil is about 3.0 to about 10.0 weight percent and said polymeric material is about 3.0 to about 15.0 weight percent.

29. The method of Claim 23 wherein said coating composition has an asphaltic component selected from the group consisting of a naturally-occurring asphalt, a by-product of refined crude oil, an asphalt cutback, an asphalt emulsion, an asphaltite and a combination thereof.