BITUMEN-CONTAINING MIXTURES, METHOD FOR PRODUCTION AND USE THEREOF

Abstract

The present invention relates to novel bitumen-containing mixtures, to a method for the production thereof and to the use thereof.

Claims

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

2. The mixture according to claim 1, wherein the mixture comprises, as sulfurized fatty acid and/or esters thereof, compounds of the formula (I) ##STR00004## where n=0-8, R.sup.1H, C.sub.1-C.sub.3 alkyl, R.sup.2H, C.sub.1-C.sub.8alkyl, x=0-10, y=0-10, z=independently 0-20 and/or of the formula (II) ##STR00005## where a=0-26, b=0-3 and RH, C.sub.1-C.sub.8alkyl.

3. The mixture according to claim 1, wherein the sulfurized C.sub.5-C.sub.30 fatty acid is aliphatic monocarboxylic acids from triglycerides obtained from natural oils such as palm oil, sunflower oil, maize oil, soya oil, linseed oil, rapeseed oil, tung oil, castor oil, tall oil, cottonseed oil, peanut oil, safflower oil, and/or maize stillage oil and sulfurized by reaction with elemental sulfur and optionally hydrogen sulfide.

4. The mixture according to claim 1, wherein the proportion of sulfur in the sulfurized C.sub.5-C.sub.30 fatty acid and/or esters thereof with a monofunctional C.sub.1-C.sub.8 alcohol is 8-29% by weight.

5. The mixture according to any of claim 1, wherein the sulfurized C.sub.5-C.sub.30 fatty acid and/or esters thereof with a monofunctional C.sub.1-C.sub.8 alcohol has/have a number-average molar mass Mn of <880 g.Math.mol.sup.1.

6. The mixture according to claim 1, wherein the proportion of di- and/or triglycerides is between 0.001 and 0.75% by weight based on the sulfurized C.sub.5-C.sub.30 fatty acid and/or esters thereof with a monofunctional C.sub.1-C.sub.8 alcohol.

7. The mixture according to claim 1, wherein vulcanized rubber has been stirred therein, that, prior to being incorporated, was treated with dialkyl polysulfides of the formula (III) ##STR00006## where R.sup.3 and R.sup.4 may be identical or different and represent a linear or branched C.sub.1-C.sub.18 alkyl radical and d represents numbers from 3 to 12.

8. A method for producing the mixture according to any of claim 1, characterized in that wherein bitumen is mixed at temperatures of 100 to 200 C. with at least one sulfurized C.sub.5-C.sub.36 fatty acid and/or esters thereof with a monofunctional C.sub.1-C.sub.8 alcohol having a sulfur content of 8% to 29% by weight and a proportion of di- and/or triglycerides of 5% by weight and optionally dialkyl polysulfide of the formula (III) and vulcanized rubber.

9. An asphalt mixture comprising rock and the mixture according to claim 1.

10. A method for producing the asphalt mixture according to claim 9, wherein the mixture according to claim 1 is mixed with the rock at temperatures of 100 to 200 C.

11. A method of binding rock aggregates in asphalt comprising incorporating the mixture according to claim 1 in asphalt used in road construction and as a road surface.

12. A method of reducing a processing temperature of asphalt comprising incorporating the mixture according to claim 1 into the asphalt.

13. The mixture according to claim 1, wherein the proportion of sulfur in the sulfurized C.sub.5-C.sub.30 fatty acid and/or esters thereof with a monofunctional C.sub.1-C.sub.8 alcohol is 10-27% by weight.

14. The mixture according to claim 1, wherein the proportion of sulfur in the sulfurized C.sub.5-C.sub.30 fatty acid and/or esters thereof with a monofunctional C.sub.1-C.sub.8 alcohol is 10-20% by weight.

15. The mixture according to any of claim 1, wherein the sulfurized C.sub.5-C.sub.30 fatty acid and/or esters thereof with a monofunctional C.sub.1-C.sub.8 alcohol has/have a number-average molar mass Mn between 350 and 750 g.Math.mol.sup.1.

16. The mixture according to any of claim 1, wherein the sulfurized C.sub.5-C.sub.30 fatty acid and/or esters thereof with a monofunctional C.sub.1-C.sub.8 alcohol has/have a number-average molar mass Mn from 450 to 680 g.Math.mol.sup.1.

Description

EXPERIMENT EXAMPLES

[0070] The following mixtures were used here:

[0071] Road bitumen of type 50/70 from Shell AG.

[0072] Asphalt mix of type AC 11 D S: Asphalt concrete with rock of rhyolite type (quartz porphyry) with an upper particle size of 11 mm for a top layer (D) with heavy stress(S)

As Sulfurized Additives:

[0073] Additive 1) Sulfurized methyl ester of rapeseed fatty acid: S content: 17% by weight, kinematic viscosity: 55 mm.sup.2/s at 40 C., di-/triglycerides 1% by weight, number-average molar mass Mn 600 g.Math.mol.sup.1, [0074] Additive 2) Sulfurized palm oil: S content: 6% by weight, triglyceride content: >90% by weight, kinematic viscosity: 250 mm.sup.2/s at 40 C., produced in the laboratory in accordance with the teaching of EP-A-3262083, number-average molar mass Mn 890 g.Math.mol.sup.1, [0075] Additive 3) Sulfurized rapeseed oil: S content: 15% by weight, triglyceride content: >90% by weight, kinematic viscosity: 300 mm.sup.2/s at 40 C., number-average molar mass Mn 890 g.Math.mol.sup.1, [0076] Additive 4) Sulfurized oleic acid: S content: 15%, di-/triglyceride content: <1% by weight, kinematic viscosity: 500 mm.sup.2/s at 40 C., number-average molar mass Mn 490 g.Math.mol.sup.1

[0077] The number-average molar mass Mn was determined by gel-permeation chromatography (GPC) measurement at 40 C. using a RI detector with tetrahydrofuran (THF) as eluent and with the PSS-SDV column combination from the supplier PSS as stationary phase (molecular weight range between 100 and 10 000 g/mol; column length 300 mm; column diameter 8 mm; particle size 5 m; pore size 100, 500 and 10 000 ), which was calibrated with polystyrene standards.

Example 1: Testing Using Bitumen Typing Quick Procedure (BTSV)

[0078] In the following experiments, various additives were added in varying proportions to type 50/70 road bitumen and tested using a bitumen typing quick procedure (BTSV). The BTSV procedure makes it possible to differentiate between modified and unmodified bitumen in the upper range of the use temperature. The two key parameters of the BTSV are the temperature T.sub.BTSV, for which the complex shear modulus G* is 15 kPa, and the associated phase angle .sub.BTSV.

[0079] The measurements were carried out in accordance with European test standard EN 14770 but, instead of the isothermal conditions described therein, the temperature was steadily increased from 20 C. to 90 C. during the measurement (T=1.2 K/min, difference from ring and ball softening point with 5 K/min). The oscillating deformation is set to a frequency of 1.59 Hz.

[0080] The mixtures were produced as follows: In the following experiments, the above sulfurized additives 1) and 3) were added to the type 50/70 road bitumen in the proportions shown in the table. For this, the type 50/70 bitumen was heated to 170 C., the appropriate additive as per the table added while stirring, and the mixture then stirred for a further 20 minutes. The results are shown in Table 1.

TABLE-US-00001 TABLE 1 BTSV measurements of additized bitumens: comparison T.sub.BTSV Bitumen variant 50/70 + additive in C. .sub.BTSV Without additive (comp.) 54.7 83.1 3% additive 1: sulfurized methyl ester of rapeseed fatty 48.1 82.9 acid, S content: 17 wt %, di-/triglycerides 1 wt % (inv.) 6% additive 1: sulfurized methyl ester of rapeseed fatty 41.9 82.8 acid, S content: 17 wt %, di-/triglycerides 1 wt % (inv.) 3% additive 3: sulfurized rapeseed oil (S content 15 50.3 84.2 wt %, di-/triglycerides: >90 wt % (comp.) inv. = inventive, comp. = comparative example

[0081] As can be seen from the examples, mixtures according to the invention lower the T.sub.BTSV significantly and are eminently suitable for lowering the processing temperature of hot asphalt. It should also be noted that the phase angle .sub.BTSV for road bitumen exhibits a typical value of approx. 83.

Example 2: Determination of Compaction Temperature, Bulk Density and Marshall Compaction Temperature

[0082] The compaction temperature and bulk density and the Marshall compaction temperature extrapolated therefrom were determined for a bulk density of 2.302 [g/cm.sup.3] in accordance with 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]. These tests used a type AC 11 D S asphalt mix (which corresponds to an asphalt concrete having a rock particle size of 11 mm for top layers with heavy stress) and, as binder, a type 50/70 road bitumen or variant thereof additized as described above. Compaction temperatures of 100 C., 110 C., 135 C. and 150 C. were chosen, with 135 C. used as reference for compaction without additive. Each side of the test specimen was exposed to 50 compaction strokes. The results are shown in Table 2.

TABLE-US-00002 TABLE 2 Marshall compaction temperature in C. Compaction Bulk for bulk Asphalt mix, type AC 11 temperature density density of D S with bitumen 50/70 [ C.] [g/cm.sup.3] 2.302 [g/cm.sup.3] without additive (comp.) 135 2.302 135 +3 wt % additive 1 = sulfurized 100 2.297 103 methyl ester of rapeseed fatty 110 2.311 acid (S content 17 wt %), 135 2.325 di-/triglycerides 1 wt % 150 2.329 (inv.) +3 wt % additive 3 = sulfurized 100 2.279 121 rapeseed oil (15% S), 110 2.290 di-/triglycerides: >90 wt % 135 2.317 (comp.) 150 2.317 +3 wt % additive 2 = 100 2.292 120 sulfurized palm oil (S content: 110 2.290 6%) di-/triglycerides: >90% 135 2.313 (comp.) 150 2.325 +3 wt % additive 4 = sulfurized 100 2.291 112 oleic acid 15 wt % S, di-/ 110 2.300 triglyceride content: <1 wt % 135 2.327 (inv.) 150 2.329 inv. = inventive, comp. = comparative example

[0083] As can be seen, the temperature-lowering effect during compaction when using the sulfurized methyl ester of rapeseed fatty acid and sulfurized oleic acid employed in accordance with the invention is very pronounced. Here, lowerings of >30 K (sulfurized methyl ester) and >20 K (sulfurized oleic acid) are achieved; in the case of sulfurized rapeseed oil and palm oil the effect with otherwise the same level of dosing is only half as great. The use of the mixtures of the invention resulted in an asphalt mixture with a considerable reduction in emissions and accordingly improved health protection during road construction.