Novel bitumen-based mixture, method for producing same and use thereof

Abstract

The present invention relates to a bitumen-based mixture, a method for producing the same, and use thereof.

Description

Technical Field

[0001] The present invention relates to a novel bitumen-containing mixture, a method for producing the same, and its use.

Background Art

[0002] Bitumen is an important binder in asphalt, which is used together with rock aggregates for pavement strengthening in road construction, floor covering in building structures, and waterproofing in hydraulic engineering and landfill structures.

[0003] In road construction by applying conventional hot mixing, the heated bitumen emits emissions (vapors, aerosols), the amount of which depends on the composition and temperature of the bitumen. Most of the gases released are alkanes, alkenes, and low-boiling aromatic compounds (benzene, toluene, ethylbenzene, xylene). In addition, depending on the bitumen or the crude oil from which it is derived, the emissions may also contain, for example, 0.1 to 5% sulfur-containing hydrocarbons (Non-Patent Document 1). The higher the temperature of the asphalt during road construction, the higher the concentration of the vapors and aerosols emitted. As a rule of thumb, reducing the temperature by 10 °K halves the emissions, so reducing the temperature by 30 °K achieves a saving of 9 kWh of energy per ton of asphalt mix (Guidelines on Asphalt (Non-Patent Document 2)).

[0004] The Committee on Hazardous Substances in Germany has adopted a limit value of 1.5 mg / m 3 for vapors and aerosols during the heating process of bitumen in the workplace.

[0005] Therefore, from the viewpoints of both health protection and environmental protection, it is necessary to aim to keep the temperature of the heated asphalt during road construction as low as technically possible. An important factor here is usually the bitumen that enables the adjustment of the processing temperature of the asphalt through it.

[0006] This can be achieved, on the one hand, with mineral additives such as zeolite (which forms foamed bitumen by releasing water vapor) or viscosity-reducing or “chemical” additives such as wax or amine in bitumen (Non-Patent Document 3). However, these additives have drawbacks. The discharge of water vapor from mineral additives consumes thermal energy, amine as an additive is a harmful substance with considerable aquatic toxicity, and wax causes brittleness as a result of crystallization at low temperatures (Non-Patent Document 4).

[0007] As an alternative to them, glycerides, preferably triglycerides, in a state combined with fatty acids, for example, as an alternative to bitumen or as an auxiliary agent for improving the solubility of polymers as described in (Patent Document 1), can be mentioned. However, the drawback in this case is that its effect is low.

[0008] (Patent Document 2) describes oil from renewable raw materials polymerized by sulfidation for road construction. There, oil or ester from renewable raw materials having a sulfur content of 0.001% to 8% by weight was used. The drawback here is also that the effect of its triglyceride is low.

Prior Art Documents

Patent Documents

[0009]

Patent Document 1

Patent Document 2

Non-Patent Documents

[0010]

Non-Patent Document 1

Non-Patent Document 2

Non-Patent Document 3

Non-Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0011] Developing from the above prior art, the object of the present invention is to provide an improved bitumen-containing mixture using additives having correspondingly better performance, thereby making it possible to maintain the lowest possible processing temperature of heated asphalt during road construction.

Means for Solving the Problems

[0012] Surprisingly, this object is achieved by adding to the bitumen at least one sulfurized C5-C having a sulfur content of 1 wt% to 29 wt% and a proportion of di- and / or triglycerides of 5 wt% or less 30It has been found that it can be achieved with a mixture containing esters of fatty acids and / or their monofunctional C1-C8 alcohols.

Mode for Carrying Out the Invention

[0013] The present invention relates to bitumen and at least one sulfurized C5-C having a sulfur content of 1% to 29% by weight and a proportion of di- and / or triglycerides of 5% by weight or less. 30 Provided is a mixture containing at least one C1-C8 alkyl ester of a fatty acid and / or a sulfurized fatty acid and a monofunctional C1-C8 alcohol.

[0014] The function of bitumen, which occupies about 4-7% of the road surface, is the function of a binder for rock. This binder gives internal cohesion to asphalt. Therefore, this is extremely important because bitumen adheres to the surface of rock with a high binding force.

[0015] Bitumen refers to a mixture of various organic substances that are either naturally occurring or obtained by distillation from crude oil. Since it is of biological origin, bitumen is mainly composed of carbon and hydrogen. It is a mixture of low-volatility and dark-colored complex organic substances having viscoelastic behavior that changes with temperature.

[0016] For the purposes of the present invention, bitumen can be various types of bitumen or bitumen-based substances. For example, it includes naturally occurring bitumen, bitumen obtained by processing crude oil and / or other heavy hydrocarbons, or otherwise synthetically produced bitumen. Bitumen that can be used for the purposes of the present invention is various commercially available types of bitumen, such as road bitumen of type 50 / 70 or 70 / 100. Preferably, this includes road bitumen described in DIN EN 12591.

[0017] Bitumen can have a viscosity of about 30 to 500 Pa·s at 60 °C, measured, for example, in accordance with DIN EN 12596. Bitumen can additionally preferably have a penetration of about 20 to 220 (in 0.1 mm units) at 25 °C, measured in accordance with DIN EN 1426 (Standard test method for penetration of bituminous substances) (Siegen University Highway Research Institute, teaching material for road construction technology part 1, 2018).

[0018] Sulfurized C5 - C 30 For the purposes of the present invention, fatty acids are preferably aliphatic monocarboxylic acids obtained from natural oils such as palm oil, sunflower oil, corn oil, soybean oil, linseed oil, rapeseed oil, castor oil, castor oil, tall oil, cottonseed oil, peanut oil, safflower oil and / or corn distillation residue oil and sulfided by reaction with elemental sulfur and optionally hydrogen sulfide. The reaction with elemental sulfur and optionally hydrogen sulfide is preferably carried out in this case at a temperature of 120 °C to 180 °C.

[0019] C1 - C8 alkyl esters from sulfurized fatty acids and monofunctional C1 - C8 alcohols are preferably the sulfidation products of the reaction of the above - mentioned fatty acids from palm oil, sunflower oil, corn oil, soybean oil, linseed oil, rapeseed oil, castor oil, castor oil, tall oil, cottonseed oil, peanut oil, safflower oil and / or corn distillation residue oil with methanol and / or ethanol. The preparation of the C1 - C8 alkyl esters is preferably carried out at a temperature higher than 40 °C.

[0020] In a particularly preferred embodiment of the present invention, sulfurized C5 - C 30 esters of fatty acids and / or their monofunctional C1 - C8 alcohols have the formula (I)

Chemical formula

Chemical formula

[0021] C1-C8 alkyl esters from sulfurized fatty acids and monofunctional C1-C8 alcohols are particularly preferably methyl or ethyl esters, most preferably methyl esters, for the purposes of the present invention.

[0022] It is preferred to use sulfurized C1-C8 alkyl esters of fatty acids derived from plants or animals, such as oleic acid, preferably sulfurized methyl esters.

[0023] Sulfurized C5-C 30 When sulfurized C5-C fatty acids and / or esters thereof with monofunctional C1-C8 alcohols are used simultaneously, the ratio is preferably 50:50 to 10:90.

[0024] Sulfurized C5-C 30 The sulfur content in sulfurized C5-C fatty acids and / or esters thereof with monofunctional C1-C8 alcohols is preferably 9-29% by weight, more preferably 10-27% by weight, and most preferably 10-20% by weight, based on sulfurized C5-C fatty acids and / or their alkyl esters. 30 is preferably 9-29% by weight, more preferably 10-27% by weight, and most preferably 10-20% by weight, based on sulfurized C5-C fatty acids and / or their alkyl esters.

[0025] Sulfurized C5 - C 30 The proportion of di - and / or triglycerides in the ester with fatty acids and / or its monofunctional C1 - C8 alcohols is less than 0.8% by weight, more preferably 0.001% to 0.75% by weight, based on the fatty acid or its alkyl ester.

[0026] In a further preferred embodiment of the present invention, sulfurized C5 - C 30 The ester with fatty acids and / or its monofunctional C1 - C8 alcohols has a number average molar mass Mn of less than 880 g·mol -1 , more preferably 350 - 750 g·mol -1 , even more preferably 450 - 680 g·mol -1 The reported value of the number average molar mass Mn is based on measurements by gel permeation chromatography (GPC) under the following conditions: 40 °C; using an RI detector; using tetrahydrofuran (THF) as the eluent; using a combination of "PSS - SDV" columns from PSS as the stationary phase (molecular weight range; 100 - 10,000 g / mol; column length = 300 mm; column diameter = 8 mm; particle size = 5 μm; pore size = 100, 500 and 10,000 Å, calibrated using polystyrene standards).

[0027] The amount of sulfurized fatty acids and / or their esters with monofunctional C1 - C8 alcohols in the bitumen is preferably 0.01 - 25% by weight, more preferably 1 - 10% by weight.

[0028] In a further embodiment of the present invention, the bitumen used preferably contains vulcanized rubber from shredded tires, which, before being incorporated into the mixture of the present invention, have the formula (III): R 3 -S d -R 4 (III) (wherein R 3 and R 4 may be the same or different and represent linear or branched C1 - C 18 alkyl groups, and d represents a number from 3 to 12, preferably 8) It is preferably treated with a dialkyl polysulfide. In a further embodiment of the present invention, the dialkyl polysulfide of formula (III) is preferably dioctyl pentasulfide and / or dioctyl tetrasulfide containing a branched C8 alkyl, more preferably dioctyl pentasulfide and / or dioctyl tetrasulfide.

[0029] The dialkyl polysulfide is preferably used in an amount of 1.5% to 3% by weight, more preferably 1.7% to 2.5% by weight based on the vulcanized rubber.

[0030] The vulcanized rubber is a sulfur-crosslinked rubber based on a polydiene of R group (including natural rubber (NR), butadiene rubber (BR), styrene-butadiene rubber (SBR), acrylonitrile-butadiene rubber (NBR) and butyl rubber (IIR)), a vulcanizate from a rubber of M group having a polymer backbone containing only a few double bonds or no double bonds (including ethylene-propylene-diene rubber (EPDM)), and a mixture of the above-mentioned R group and M group rubbers. It is particularly preferred to use a rubber tire as a source of the vulcanized rubber.

[0031] The vulcanized rubber, preferably the rubber tire, is preferably used with a particle size of 0.15 to 3 mm, more preferably 0.2 to 1 mm. In such applications, it may be necessary to pulverize the vulcanized rubber. This is ideally carried out using a shredder and a mill and / or a cutter. For this purpose, it is preferred to use a double-shaft shredder and a cutting mill.

[0032] In the vulcanized rubber using the dialkyl polysulfide of formula (III), the rubber is desulfurized by cleaving the sulfur crosslinks, thereby improving its solubility in bitumen. The treatment is preferably carried out at a temperature of 130 to 150 °C. The mixture thus obtained is preferably heat-treated within 20 minutes and then mixed with bitumen.

[0033] The amount of the dialkyl polysulfide of formula (III) for cleaving the sulfur crosslinks in the vulcanized rubber is preferably 1.5% to 3% by weight, more preferably 1.7% to 2.5% by weight, based on the amount of the vulcanized rubber.

[0034] The cleavage of the sulfur crosslinks in the vulcanized rubber using the dialkyl polysulfide of formula (III) is preferably carried out according to the method described in European Patent Application Publication No. A3771727. In a further preferred embodiment of the present invention, it is preferable to meter and add the dialkyl polysulfide to the vulcanized rubber via a nozzle.

[0035] The present invention further provides a method for producing the mixture of the present invention, which comprises mixing at least one sulfurized C5 - C having a sulfur content of 1% to 29% by weight, preferably 8% to 29% by weight, more preferably 10% to 27% by weight, most preferably 10% to 20% by weight and a proportion of di - and / or triglycerides of 5% or less by weight, 30 an ester of a fatty acid and / or its monofunctional C1 - C8 alcohol and optionally a dialkyl polysulfide of formula (III) and a vulcanized rubber or a rubber desulfurized with a dialkyl polysulfide with bitumen at a temperature of 100 - 200°C.

[0036] In a preferred embodiment of the present invention, the sulfurized C5 - C 30 ester of a fatty acid and / or its monofunctional C1 - C8 alcohol is a compound of formula (I) and / or (II).

[0037] The mixing is preferably carried out under mechanical stress. For the purposes of the present invention, mechanical stress means, for example, using the following mixing units; preferably an extruder, an internal mixer, a high-pressure homogenizer, for example in particular a high-shear mixing device, for example Ultra-Turrax®, a kneader and / or a roll mill. In industrial scale operations, it is particularly preferred to use an extruder and / or an internal mixer, but there are no particular restrictions on the type of extruder and / or internal mixer. In laboratory scale, a high-shear mixing device, for example Ultra-Turrax® or otherwise an anchor stirrer having at least two paddles is particularly preferred.

[0038] The present invention further provides an asphalt mixture comprising rock and the mixture of the present invention.

[0039] For the purposes of the present invention, an asphalt mixture is a mixture comprising natural or industrially produced bitumen and rock (rock aggregate). This is preferably used for pavement strengthening in road construction, floor covering in building structures, and waterproofing in hydraulic engineering and landfill structures. The mixing ratio is preferably 90 to 95% by weight of rock / rock aggregate and about 5 to 10% by weight of bitumen. However, this ratio can also be varied upwards or downwards. The behavior of the material changes accordingly depending on the addition amount of bitumen (referred to as the binder content) and the hardness (i.e., the type of binder).

[0040] For the purposes of the present invention, the rock is preferably natural rock aggregate, preferably those described in DIN EN 13043, which are preferably those subjected to mechanical preparation methods, such as crushing and screening.

[0041] The rock aggregates used in asphalt mixes for road construction must meet the requirements of DIN EN 13043 and TL Gestein-StB 04 [Technical Conditions for the Supply of Rock Aggregates in German Road Construction]. For example, the top layer mixture of asphalt is composed of rock aggregates with a maximum size of up to 16 mm.

[0042] The requirements for rock aggregates are defined, inter alia, in DIN 18196 ("Earthworks and foundations - Soil classification for civil engineering purposes") and TL Gestein-StB, 2004 version (p. 11).

[0043] The rock can, in this case, preferably be present either in the uncrushed form (as round particles), especially as gravel, sand, crushed stone and chippings or in the crushed form.

[0044] The amount of rock is preferably at most 95% by weight, preferably 90% to 95% by weight, based on the total amount of bitumen.

[0045] For the bitumen used in the asphalt mixtures of the present invention and esters of sulfurized C5 - C 30 fatty acids and / or their monofunctional C1 - C8 alcohols, reference is made to the previous description of the mixtures of the present invention.

[0046] In one embodiment, the asphalt mixture of the present invention further comprises additional substances and / or fillers, such as fibrous substances or metal compounds / salts, such as organic zinc compounds / salts, which function, inter alia, as sulfide scavengers and thus as odor suppressants.

[0047] In a further preferred embodiment of the present invention, the asphalt mixture has the following composition: Bitumen: 4 - 8% by weight, Rock: 80 - 96% by weight, Sulfurized C5 - C30 Esters of fatty acids and / or their monofunctional C1-C8 alcohols: 0.001 to 2% by weight, preferably 0.1% to 1% by weight, and Optionally, further additive substances and / or fillers: 0 to 20% by weight, and Optionally, vulcanized rubber (preferably treated with a dialkyl polysulfide of formula (III)). The sum of these components is 100% by weight.

[0048] The present invention further provides a method for producing the asphalt mixture of the present invention, wherein at least the mixture of the present invention is mixed with rock at a temperature of 100 to 200 °C. It is preferred to add the dialkyl polysulfide of formula (III) to the rubber in an independent step and then mix the rubber thus treated with the bitumen.

[0049] In a preferred embodiment of the present invention, sulfurized C5-C 30 The C1-C8 alkyl esters of fatty acids and / or sulfurized fatty acids and monofunctional C1-C8 alcohols are compounds of formula (I) and / or (II).

[0050] The mixing is preferably carried out in an asphalt mixing unit. In this case, a continuous or discontinuous mixing process can be used, and the unit used can be stationary, easily movable, or on casters.

[0051] The present invention further provides the use of the asphalt mixture of the present invention as a binder for rock aggregates in asphalt in road construction, preferably as a road surface.

[0052] The present invention relates to at least one sulfurized C5-C having a sulfur content of 1% to 29% by weight, preferably 8 to 29% by weight, more preferably 10 to 27% by weight, most preferably 10 to 20% by weight and a proportion of di- and / or triglycerides of 5% by weight or less in bitumen. 30There is further provided the use of a mixture comprising a fatty acid and / or an ester thereof with a monofunctional C1-C8 alcohol for reducing the processing temperature of asphalt.

[0053] The present invention will be described in more detail with reference to the following examples, but the present invention is in no way limited to the above examples.

Examples

[0054] Here, the following mixtures were used: Road bitumen, type 50 / 70 (manufactured by Shell AG) Asphalt mix, type AC 11DS: Asphalt concrete with rhyolite-type rock (quartz porphyry) having heavy stress (S) added for the top layer (D), maximum particle size 11 mm As a sulfurized additive, Additive 1) Methyl ester of sulfurized rapeseed fatty acid: S content: 17% by weight, kinematic viscosity: 55 mm 2 / s (40 °C), di- / triglyceride: 1% by weight or less, number average molar mass Mn: about 600 g·mol -1 , Additive 2) Sulfurized palm oil: S content: 6% by weight, triglyceride content: more than 90% by weight, kinematic viscosity: 250 mm 2 / s (40 °C), manufactured in the laboratory according to the teachings of European Patent Application Publication No. A3262083, number average molar mass Mn: about 890 g·mol -1 , Additive 3) Sulfurized rapeseed oil: S content: 15% by weight, triglyceride content: more than 90% by weight, kinematic viscosity: 300 mm 2 / s (40 °C), number average molar mass Mn: about 890 g·mol -1 , Additive 4) Sulfurized oleic acid: S content: 15%, di- / triglyceride content: less than 1% by weight, kinematic viscosity: 500 mm 2 / s (40 °C), number average molar mass Mn: about 490 g·mol -1 .

[0055] The number average molar mass Mn was determined by gel permeation chromatography (GPC) measured under the following conditions: 40 °C; using an RI detector; using tetrahydrofuran (THF) as the eluent; using a combination of "PSS-SDV" columns manufactured by PSS as the stationary phase (molecular weight range: 100 - 10,000 g / mol; column length = 300 mm; column diameter = 8 mm; particle size = 5 μm; pore diameters = 100, 500 and 10,000 Å, calibrated using polystyrene standards).

[0056] Example 1: Test using the Bitumen High-Speed Characterization Test (BTSV) In the following experiments, various additives were added to type 50 / 70 road bitumen while varying the proportions, and the tests were conducted using the Bitumen High-Speed Characterization Test (BTSV). The BTSV method enables the distinction between modified and unmodified bitumen in the high-temperature range of the service temperature. Two important parameters of BTSV are the complex shear modulus G * at the temperature at which G becomes 15 kPa, which is T BTSV and the associated phase angle δ BTSV respectively.

[0057] The measurements were carried out in accordance with European test standard EN 14770, but instead of the isothermal conditions described therein, the temperature was increased at a constant rate from 20 °C to 90 °C during the measurement (ΔT = 1.2 K / min, 5 K / min change from the ring-and-ball softening point). The vibration deformation was set to a frequency of 1.59 Hz.

[0058] The mixtures were prepared as follows: In the following experiments, the above-mentioned sulfurized additives 1) and 3) were added to type 50 / 70 road bitumen at the ratios shown in the table. For this purpose, type 50 / 70 bitumen was heated to 170 °C, and while stirring, the appropriate additives were added in the amounts described in the table, and then the mixture was stirred for an additional 20 minutes. The results are shown in Table 1.

[0059]

Table 1

[0060] As can be seen from the examples, the mixture according to the present invention significantly reduces T BTSV and is extremely suitable for reducing the processing temperature of heated asphalt. Note that the phase angle δ BTSV for road bitumen also shows a typical value of about 83 degrees.

[0061] Example 2: Measurement of Compaction Temperature, Bulk Density and Marshall Compaction Temperature According to the Technical Test Conditions (TP) for asphalt for road construction, FGSV No. 756, part 30: Production of Marshall test specimens using the Marshall compaction apparatus (MVG) and also the "Information sheet for temperature lowering in asphalt", 2011 version, of the FGSV [German Road and Transportation Research Association], when determining the compaction temperature, bulk density and the Marshall compaction temperature extrapolated therefrom, a bulk density of 2.302 [g / cm 3 was obtained. In these tests, type AC 11 DS asphalt mix (which corresponds to asphalt concrete with 11 mm rock particle size for the top layer having heavy stress) and as binder, type 50 / 70 road bitumen added as described above or its variants were used. Compaction at 100 °C, 110 °C, 135 °C and 150 °C was selected, and 135 °C was used as a reference for compaction without additive. Each side of the test specimen was exposed to 50 compaction strokes. The results are shown in Table 2.

[0062]

Table 2

[0063] As can be seen, when using the methyl ester of rapeseed fatty acid sulfide and oleic acid sulfide used in the present invention, the temperature drop effect during compaction is extremely large. In this case, a drop of more than 30 °K (methyl ester sulfide) and more than 20 °K (oleic acid sulfide) has been achieved. In the case of rapeseed oil sulfide and palm oil sulfide, the effect when the usage amount is the same level and others are the same is only half as large. By using the mixture of the present invention in the asphalt mixture, the emissions are considerably reduced, and accordingly, the health maintenance during road construction is improved.

Claims

1. A mixture comprising bitumen and at least one sulfurized C having a sulfur content of 1% to 29% by weight and a proportion of di- and / or triglycerides of 5% by weight or less ５ -C ３０ fatty acids and / or its monofunctional C １ -C ８ esters with alcohols.

2. As the sulfurized fatty acid and / or its ester, formula (I) 【Chemical 1】 (wherein, n = 0 to 8, R １ = H, C １ ~ C ３ is alkyl, R ２ = H, C １ ~ C ３ is alkyl, x = 0 to 10, y = 0 to 10, z is independently 0 to 20), and / or formula (II) 【Chemical 2】 (wherein, a = 0 to 26, b = 0 to 3, and R = H, C １ ~C ８ is alkyl) The mixture according to claim 1, characterized by containing the compound of.

3. Sulfurized C ５ -C ３０ The fatty acid is an aliphatic monocarboxylic acid obtained from natural oils such as palm oil, sunflower oil, corn oil, soybean oil, linseed oil, rapeseed oil, castor oil, castor oil, tall oil, cottonseed oil, peanut oil, safflower oil and / or corn distillation residue oil, and sulfided by reaction with elemental sulfur and optionally hydrogen sulfide, and the mixture according to claim 1 or 2, characterized in that.

4. The sulfur in the sulfide C ５ -C ３０ fatty acid and / or its monofunctional C １ -C ８ The proportion of sulfur in the ester with alcohol is 8 to 29% by weight, preferably 10 to 27% by weight, more preferably 10 to 20% by weight, and the mixture according to any one of claims 1 to 3 is characterized in that.

5. The sulfurized C ５ -C ３０ fatty acid and / or its monofunctional C １ -C ８ ester with alcohol has a number-average molar mass Mn of less than 880 g / mol －１ , more preferably 350 to 750 g / mol －１ , even more preferably 450 to 680 g / mol －１ The mixture according to any one of claims 1 to 4, characterized in that it has a number-average molar mass Mn of

6. The proportion of said di- and / or triglycerides is based on the ester of said sulfurized C ５ -C ３０ fatty acid and / or its monofunctional C １ -C ８ with an alcohol and is 0.001 to 0.75% by weight, and the mixture according to any one of claims 1 to 5 is characterized thereby.

7. Before being incorporated, the vulcanized rubber treated with the dialkyl polysulfide of formula (III) R ３ -S ｄ -R ４ (III) (wherein R ３ and R ４ may be the same or different and each represents a linear or branched C １ -C １８ alkyl group, and d represents a number from 3 to 12). The mixture according to any one of claims 1 to 6, characterized in that it is stirred in the said mixture.

8. In a process for producing a mixture according to any one of claims 1 to 7, the bitumen is at a temperature of 100 to 200 °C, at least one sulfurized C having a sulfur content of 8% to 29% by weight and a proportion of di- and / or triglycerides of 5% by weight or less ５ ~C ３０ fatty acid and / or its mono-functional C １ ~C ８ ester with alcohol and optionally a dialkyl polysulfide of formula (III) and a vulcanized rubber, characterized in that it is mixed therewith.

9. An asphalt mixture containing rock and the mixture according to any one of claims 1 to 7.

10. In the method for producing the asphalt mixture according to claim 9, at least one mixture according to any one of claims 1 to 7 is mixed with the said rock at a temperature of 100 to 200 °C. A method characterized by this.

11. Use of the mixture according to any one of claims 1 to 7 in road construction and as a road surface.

12. Use of the mixture according to any one of claims 1 to 7 for reducing the processing temperature of asphalt.

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