BITUMEN COMPOSITION

Abstract

The invention is directed to a bitumen composition, to a paving, to a roofing, to a method for preparing a bitumen composition, to a method for increasing the stiffness of a bitumen composition, to a method of adjusting the physical properties of a bitumen composition, and to the use of a bitumen composition. The bitumen composition of the invention comprises a lignin compound or derivative thereof, wherein 10 wt. % or more by weight of said lignin compound or derivative thereof is molecularly dissolved in said bitumen composition.

Claims

1. Bitumen composition comprising a lignin compound or derivative thereof, wherein 10 wt. % or more by weight of said lignin compound or derivative thereof is molecularly dissolved in said bitumen composition.

2. Bitumen composition according to claim 1, wherein said composition comprises 10 wt. % or more by weight of the bitumen composition of said lignin compound or derivative thereof.

3. Bitumen composition according to claim 1, wherein said composition comprises 20 wt. % or more by weight of the bitumen composition of said lignin compound or derivative thereof.

4. Bitumen composition according to claim 1, wherein said composition comprises 25-50 wt. % by weight of the bitumen composition of said lignin compound or derivative thereof.

5. Bitumen composition according to claim 1, wherein said lignin compound or derivative thereof is substantially free of sulfur.

6. Bitumen composition according to claim 1, wherein said lignin compound or derivative thereof is completely free of sulfur.

7. Bitumen composition according to claim 1, wherein said lignin compound or derivative thereof is a chemically modified lignin.

8. Bitumen composition according to claim 7, wherein said chemically modified lignin is chemically modified with one or more groups selected from the group consisting of anhydrides, epoxy carrying reactants, and halide containing compounds.

9. Bitumen composition according to claim 7, wherein said chemically modified lignin compound comprises one or more units represented by formula (II) below ##STR00004## wherein R represents a lignin residue; R is selected from the group consisting of C.sub.1-20 alkyl, C.sub.2-20 alkenyl, (C.sub.1-20 alkyl)-phenyl, (C.sub.2-20 alkenyl)-phenyl, C.sub.1-20 alkoxy, (C.sub.1-20 alkoxy)-phenyl, C.sub.3-6 cycloalkyl, aryl-(C.sub.1-6 alkyl), aryl-(C.sub.2-6 alkenyl), and (C.sub.1-4 alkyl)-aryl-(C.sub.1-4 alkyl); X.sup.1 is OH or H; and X.sup.2 is OH or H, and X.sup.2 is different from X.sup.1.

10. Bitumen composition according to claim 1, wherein said lignin compound or derivative thereof has a bimodal distribution of the molecular weight.

11. Bitumen composition according to claim 1, wherein the lignin compound or derivative thereof comprises 1-5 wt. % based on total weight of the lignin compound or derivative thereof of a first component having a M.sub.n of 100 000-150 000 g/mol and 95 99 wt. % based on total weight of the lignin compound or derivative thereof of a second component having a M.sub.n of 1500-2000 g/mol.

12. Bitumen composition according to claim 1, wherein 25 wt. % or more by weight of said lignin compound or derivative thereof is molecularly dissolved in said bitumen composition.

13. Bitumen composition according to claim 1, wherein 50 wt. % or more by weight of said lignin compound or derivative thereof is molecularly dissolved in said bitumen composition.

14. Bitumen composition according to claim 1, wherein 75 wt. % or more by weight of said lignin compound or derivative thereof is molecularly dissolved in said bitumen composition.

15. Bitumen composition according to claim 1, having a dynamic viscosity (*) at 20 C. and 10 rad/s in the range of 1.010.sup.4-5.010.sup.6, as determined by dynamic shear rheometer.

16. Bitumen composition according to claim 1, having a complex modulus G* at 20 C. and 110.sup.4 rad/s in the range of 110.sup.1-110.sup.5 Pa, at 20 C. and 1 rad/s in the range of 110.sup.5-110.sup.8 Pa, and at 20 C. and 110.sup.5 rad/s in the range of 110.sup.7-110.sup.9 Pa; having a corresponding phase angle at 20 C. and 110.sup.4 rad/s in the range of 30-90, at 20 C. and 1 rad/s in the range of 50-80, and at 20 C. and 110.sup.5 rad/s in the range of 10-40, as determined by dynamic shear rheometer.

17. Bitumen composition according to claim 1, further comprising one or more selected from the group consisting of a filler, sand, and rubble.

18. Paving comprising a bitumen composition according to claim 1.

19. Roofing comprising a bitumen composition according to claim 1.

20. Method of preparing a bitumen composition comprising molecularly dissolving 10 wt. % or more by weight of a lignin compound or derivative thereof into a bitumen composition.

21. Method according to claim 20, wherein said lignin compound or derivative thereof is substantially or completely free of sulfur.

22. Method of increasing the stiffness of a bitumen composition, said method comprising molecularly dissolving a lignin compound or derivative thereof in said bitumen composition.

23. Method of adjusting the physical properties of a bitumen composition, said method comprising adding to the bitumen composition comprising a lignin compound or derivative thereof, wherein said lignin compound or derivative thereof is optionally chemically modified.

24. (canceled)

Description

EXAMPLES

Synthesis Example 1

[0099] 100 grams of organosolv lignin was added to 1 l 0.1 M sodium hydroxide solution in water at 50 C. and subsequently 26 ml ethylhexyl glycidyl ether was added. After 24 hours, the mixture was cooled, neutralised, centrifuged, dialysed and freeze-dried after which the product was isolated and used in follow up experiments. The yield was 120 grams.

Synthesis Example 2

[0100] 100 grams of organosolv lignin was added to 1 l 0.1 M sodium hydroxide solution in water at 50 C. and subsequently 15 ml allyl glycidyl ether was added. After 24 hours the mixture was cooled, neutralised, centrifuged, dialysed and freeze-dried after which the product was isolated and used in follow up experiments. The yield was 65 grams.

Synthesis Example 3

[0101] 100 grams of organosolv lignin was added to 1 l 0.1 M sodium hydroxide solution in water at 50 C. and subsequently 17 ml 1,2-epoxy-3-phenoxy propane ether was added. After 24 hours, the mixture was cooled, neutralised, centrifuged, dialysed and freeze-dried after which the product was isolated and used in subsequent experiments. The yield was 85 grams.

Synthesis Example 4

[0102] 100 grams of organosolv lignin was added to 1 l 0.1 M sodium hydroxide solution at 50 C. and subsequently 26 ml ethylhexyl glycidyl ether was added. After 24 hours, the mixture was cooled, centrifuged, dialysed and freeze-dried after which the product was isolated and used in follow up experiments. The yield was 52 grams.

Synthesis Example 5

[0103] 100 grams of organosolv lignin was added to 1 l 0.1 M sodium hydroxide solution at 50 C. Subsequently 10 gram sodiumborohydride were added. After 24 hours, the mixture was cooled down, centrifuged, dialysed and freeze-dried after which the product was isolated and used in follow up experiments. The yield was 45 grams.

Comparative Synthesis Example

[0104] To 1 l 0.1 M sodium hydroxide solution at 50 C., 26 ml ethylhexyl glycidyl ether was added. After 24 hours, the mixture was cooled, centrifuged, dialysed and freeze-dried exactly as the earlier lignin containing products were isolated. The result was that no polymeric product was present. The yield was 20 milligrams.

Example 1

[0105] Bitumen (70/100) was heated to about 170 C. Heating was done with a heating plate and the bitumen was mixed for about 15 minutes at 500 rotations per minute using a propeller mixer. Lignin (10 wt. %) was gradually added (in small batches) to the bitumen (with a sieve) while mixing with a propeller mixer at about 1000 rotations per minute. After all the lignin was added, the bitumen composition was homogenised by mixing at about 1000 rotations per minute for about 15 minutes at 170 C.

[0106] The average particle diameter in the bitumen composition directly after mixing and after 15 minutes of mixing was determined using polarised light microscopy. A comparison showed that after 15 minutes of mixing essentially all particles have disappeared, thereby indicating that the average particle diameter in the bitumen composition after 15 minutes of mixing is substantially less than 25% of the average particle diameter in the bitumen composition directly after mixing the components together.

Example 2

[0107] Bitumen (160/220) was heated to about 160 C. Heating was done with a heating plate and the bitumen was mixed for about 15 minutes at 500 rotations per minute using a propeller mixer. Lignin (10 wt. %) was gradually added (in small batches) to the bitumen (with a sieve) while mixing with a propeller mixer at about 1000 rotations per minute. After all the lignin was added, the bitumen composition was homogenised by mixing at about 1000 rotations per minute for about 15 minutes at 160 C.

[0108] Again, the average particle diameter in the bitumen composition directly after mixing and after 15 minutes of mixing was determined using polarised light microscopy. A comparison showed that after 15 minutes of mixing essentially all particles have disappeared, thereby indicating that the average particle diameter in the bitumen composition after 15 minutes of mixing is substantially less than 25% of the average particle diameter in the bitumen composition directly after mixing the components together.

[0109] FIG. 1 shows complex modulus of three different bitumen compositions (one conventional bitumen composition without lignin, one bitumen composition that contains 25 wt. % of native lignin, one bitumen composition that contains 25 wt. % of lignin modified with the aliphatic epoxy carrying reactants prepared in synthesis example 1, and one bitumen composition that contains 25 wt. % of lignin modified with the aromatic epoxy carrying reactants prepared in synthesis example 3). This FIGURE shows that the inclusion of lignin in the bitumen composition does affect the properties of the bitumen composition, but not to a large extent. By modification of the lignin, the complex modulus properties of the bitumen can further be tuned.

[0110] Dynamic shear tests were conducted using a Rheometrics RAA asphalt analyserDynamic Shear Rheometer (DSR). The DSR test was basically conducted to determine the viscoelastic properties, i.e. the response or dependence of the materials on temperature and loading time. In this regard, the complex modulus and phase angle at different temperatures and loading frequencies were determined.

[0111] The specimen was placed between two circular parallel plates. The upper plate was fixed; while the lower part oscillated applying the shear strain during testing. The test was carried out in a temperature controlled mini-oven (chamber). The temperature of the sample was controlled with air, for temperatures above 20 C. the sample was heated using hot air, for temperatures below 20 C. cooled air was used. The temperature control has an accuracy of 0.1 C. when adequate time (usually 10 min) is provided to stabilise the temperature. The temperature of the sample was measured in the plate. The controlling mechanism and data acquisition was performed by a computer connected to the DSR equipment.

[0112] In the DSR test, the bituminous materials were subjected to a sinusoidal loading of constant strain at different loading frequencies (frequency sweep). The frequency sweep test was conducted at eight different temperatures ranging between 10 C. and 60 C. Every test was carried out at frequencies ranging between 0.1-400 rad/s. Before conducting the frequency sweep tests (constant strain, varying frequency), a strain sweep test (constant frequency, varying strain) was performed to determine the strain level at which the material response remains in the linear region. Two parallel plate geometries with a diameter of 8 mm and 25 mm were used. Table 1 provides the testing conditions used in the DSR.

TABLE-US-00001 TABLE 1 DSR test conditions Temperatures 10, 0, 10, 20, 30, 40, 50 and 60 C. 0.1 C. Parallel plates 8 mm; 25 mm Sample thickness 2 mm; 1 mm target thickness Frequency 0.1-400 rad/s

[0113] A better understanding and analysis of rheological properties of viscoelastic materials can be made with the use of master curves. Master curves allow the estimation of properties at a wider range of temperatures and frequencies. The complex modulus master curve and the phase angle master curve were constructed. The Time-Temperature Superposition (TTS) principle was used to generate master curves of the complex modulus and phase angle at a reference temperature of 20 C. These master curves are shown in FIGS. 1 and 2.