USE OF BISAMIDE COMPOUNDS TO IMPROVE THE AGEING RESISTANCE OF BITUMEN

Abstract

The present invention relates to the use of bisamide compounds to improve the ageing resistance and/or increase the service life and/or delay the appearance of signs of ageing of a bituminous composition. The invention also relates to a method for improving the ageing resistance and/or increasing the service life and/or delaying the appearance of signs of ageing of a bituminous composition.

Claims

1.-16. (canceled)

17. A method for improving the resistance to aging and/or increasing the service life and/or delaying the appearance of signs of aging of a bituminous composition, the method comprising incorporating into the bituminous composition at least one bisamide compound of formula (I)
R.sub.AXR.sub.CXR.sub.B(I) wherein R.sub.A and R.sub.B are independently selected from the group consisting of linear, cyclic or branched, saturated or unsaturated hydrocarbon chains comprising 1 to 36 carbon atoms, and optionally comprising heteroatoms, R.sub.C is a linear, cyclic or branched, saturated or unsaturated hydrocarbon chain comprising 3 to 18 carbon atoms, optionally substituted, and optionally comprising heteroatoms, X and X represent an amide function NHCO or CONH.

18. The method according to claim 1, wherein the bisamide compound has the formula (IA)
R.sub.ACONHR.sub.CNHCOR.sub.B(IA)

19. The method according to claim 1, wherein R.sub.C represents a linear and saturated hydrocarbon chain.

20. The method according to claim 1, wherein R.sub.C is: selected from the group consisting of C.sub.4H.sub.8, C.sub.6H.sub.12, C.sub.8H.sub.16, and C.sub.10H.sub.20.

21. The method according to claim 1, wherein R.sub.A and R.sub.B, either identical or different, represent a hydrocarbon chain comprising from 4 to 22 carbon atoms.

22. The method according to claim 1, wherein R.sub.A and R.sub.B, either identical or different, represent a linear hydrocarbon chain.

23. The method according to claim 1, wherein the bisamide compound of formula (I) is used in a concentration from 0.1 to 30% by weight with respect to the total weight of the bituminous composition.

24. The method according to claim 1, wherein the bituminous composition further additives different from the bisamide compound of formula (I).

25. The method according to claim 1, wherein the bituminous composition is solid when cold and in a divided form.

26. The method according to claim 1, wherein the signs of aging are selected from the groups consisting of cracks, detachments, ruts, collapses, potholes, chipping, crumbling, blistering and crazing.

27. The method according to claim 1, for improving the resistance of the bituminous composition to oxidative and/or thermal aging.

28. The method according to claim 1, wherein the aging is caused by the presence of oxygen and/or by exposure to ultraviolet radiation and/or by thermal variation and/or by exposure to moisture and/or by exposure to weathering.

29. The method according to claim 1, for reducing the frequency of renewal and/or of renovation of the roadways.

30. The method according to claim 1, for reducing the frequency of renewal and/or of renovation of buildings.

31. The method according to claim 1, wherein the bituminous composition is a bituminous mix.

32. The method according to claim 1, for reducing and/or minimizing and/or delaying and/or attenuating the degradation of at least one mechanical property of the bituminous composition.

33. The method according to claim 32, wherein the mechanical property is selected from the group consisting of the ring and ball softening temperature, the elastic recovery and the permanent deformation.

34. The method according to claim 1, wherein the method comprises at least the following steps: i. preparation of a bituminous composition comprising at least one bisamide compound of formula (I) as defined in claim 1, ii. subjecting the bituminous composition to an aging process caused by the presence of oxygen and/or by exposure to ultraviolet radiation and/or by thermal variations and/or by exposure to moisture and/or by exposure to weathering, iii. measurement of one or a plurality of parameters selected from the group consisting of ring and ball softening temperature, non-recoverable creep compliance, and elastic recovery percentage to evaluate resistance to aging.

35. The method according to claim 34, further comprising a step of applying the bituminous composition to a roadway and/or a surface of a building after the step (i) of preparation of the bituminous composition and before step (iii).

Description

DESCRIPTION OF FIGURES

[0181] FIG. 1 represents the curves of variation of the elastic recovery r (in %, y-axis) as a function of the applied stress (in kPa, x-axis) of different bituminous compositions before aging (curves in solid lines) and after aging according to an accelerated aging protocol using a PAV for 25 h (dashed line curves) and for 48 h (dotted line curves).

EXAMPLES

[0182] The invention is illustrated by the following examples, but not limited to.

[0183] In the examples, the parts and percentages are expressed by weight unless otherwise indicated.

1Materials and Methods

[0184] Bitumen: grade 35/50 base bitumen having a P25 penetrability of 46 1/10 mm and an RBT of 53.2 C. and commercially available from TotalEnergies under the brand name AZALT. [0185] Additive 1 (according to the invention) bisamide with the formula (IA) wherein R.sub.A=R.sub.B=C17 linear and saturated and R.sub.C=(CH.sub.2).sub.4. [0186] Additive 2 (according to the invention) bisamide with the formula (IA) wherein R.sub.A=R.sub.B=C11 linear and saturated and RC=(CH.sub.2).sub.6. [0187] Additive 3 (according to the invention) bisamide with the formula (IA) wherein R.sub.A=R.sub.B=C17 is linear and contains ethylenic unsaturation between carbon atoms 8 and 9 and R.sub.C=(CH.sub.2).sub.6 [0188] Additive 4 (comparative) 2,3-bis [(3-[3,5-di-tert-butyl-4 hydroxyphenyl]propionyl)] propionohydrazide commercially available under the brand name Irganox MD 1024. [0189] Additive 5 (comparative) N,N-ethylenediol (stearamide) commercially available under the brand name Crodawax.

2Methods for Determining the Properties of Bituminous Compositions

[0190] The mechanical characteristics of the bituminous compositions to which reference is made in the present examples are measured according to the methods indicated in Table 1.

TABLE-US-00001 TABLE 1 Mechanical properties and measurement methods Measurement Property Abbreviation Unit standard Needle P.sub.25 1/10 mm NF EN 1426 penetrability at 25 C. Ring and Ball RBT C. NF EN 1427 Softening Temperature Accelerated aging PAV NF EN 14769 protocol Elastic recovery r % NF EN 13398

3Preparation of Bituminous Compositions

[0191] The additive bituminous compositions are prepared by feeding in the base bitumen and the additive into a reactor with stirring and at 170 C. in the proportions reported in Table 2 hereinbelow. The mixtures are stirred and heated at 160 C. for approximately 1 hours.

[0192] Compositions C1 to C3 are according to the invention and compositions C4 and C5 are comparative. Composition C0 is a control composition which does not comprise any additive. The proportions of the additives in the different compositions are chosen so as to obtain bituminous compositions having the same RBT value at around 100 C.

TABLE-US-00002 TABLE 2 Prepared bituminous compositions Composition C0 C1 C2 C3 C4 C5 Bitumen base 100% 98% 98% 94% 99.1% 97% Additive 1 2% Additive 2 2% Additive 3 6% Additive 4 0.9% Additive 5 3%

4Protocol for the Aging of Bituminous Compositions

[0193] The prepared bituminous compositions underwent accelerated aging using PAV equipment such as Prentex 9500 according to the following protocol: Each composition was heated at 160 C. for 40 minutes in order to be able to be transferred into metal cups (50 g+/0.5 g of composition). The cups were then placed in an aging container at 21 bars of air pressure and at a temperature of 100 C. for a defined length of time, more particularly for 25 h and 48 h. At the end of the allotted aging time, the cups were recovered and placed in an oven heated to 170 C. After 30 minutes, all cups were transferred to a single container. The container was then placed in a vacuum oven (vacuum of 15 kPa) for degassing at 177 C. for a period of 30 minutes. Finally, the product was recovered.

5Results

[0194] FIG. 1 shows the curves of variation of the elastic recovery (in %) of the compositions C0 to C5 before and after aging as a function of different stresses. The curves show that the bituminous compositions supplemented with the bisamide compounds according to the invention better recover their resistance compared to the bitumen with no additives (C0), after accelerated aging protocol using a PAV equipment at 25 h and at 48 h. The bituminous compositions with added bisamide compounds with the formula (I) exhibit very little sign of aging. The ring and ball temperature and the recovery under stress conditions at 0.1 kPa and at 3.2 kPa were measured according to the protocols described hereinabove on the different bituminous compositions prepared before aging and after aging using a PAV equipment after 25 hours, then after 48 hours. The results are shown in Tables 3, 4 and 5.

TABLE-US-00003 TABLE 3 Properties of bituminous compositions before aging RBT ( C.) r at 0.1 kPa (%) r at 3.2 kPa (%) C0 53.2 2.5 0.1 C1 105 97.8 48.2 C2 99 97.3 64.6 C3 94 97.7 82.3 C4 102.6 96.6 92.5 C5 98.5 95.4 9.5

TABLE-US-00004 TABLE 4 Properties of bituminous compositions following an accelerated aging protocol using PAV equipment at 25 h. Rate of Rate of change of change of Rate of r at r at r at r at RBT change 0.1 kPa 0.1 kPa 3.2 kPa 3.2 kPa ( C.) of RBT (%) (%) (%) (%) C0 67.8 27.4 28.6 1044 25.7 25,600 C1 103.5 1.4 91.6 7.1 64.6 34.0 C2 99.5 0.5 87.8 9.7 73.9 14.4 C3 91.0 3.2 96.6 1.1 84.7 2.9 C4 65.4 36.2 40.0 58.6 39.8 56.9 C5 95.5 3.0 77.3 19.0 45.0 373.7

TABLE-US-00005 TABLE 5 Properties of bituminous compositions following an accelerated aging protocol using PAV equipment at 48 h. Rate of Rate of change of change of Rate of r at r at r at r at RBT change 0.1 kPa 0.1 kPa 3.2 kPa 3.2 kPa ( C.) of RBT (%) (%) (%) (%) C0 72.6 36.4 43.3 1632 42.7 42,600 C1 95 9.5 80.6 17.6 64.6 34.0 C2 88 11.1 57.8 11.8 77.4 19.8 C3 90.5 3.7 89.3 8.6 83.0 0.85 C4 71 30.8 35.7 63.0 34.8 62.4 C5 95.0 3.5 87.3 18.0 56.9 489.9

[0195] It is found that the rates of variation of the ring and ball temperature (RBT) and of the elastic recovery of the bituminous compositions comprising the bisamide additives with the formula (I) according to the invention (compositions C1 to C3) are significantly lower than the corresponding rates of change in the case of a composition containing the additive Irganox (composition C4) or a bitumen composition without additives.

[0196] The compositions C1 to C3 comprising the bisamide additives with the formula (I) according to the invention exhibit lower rates of change of recovery under stress conditions at 0.1 kPa and at 3.2 kPa after 25 and 48 h compared with the composition C5 comprising a bisamide additive as described in prior art US2019/184678.

[0197] The results demonstrate that the bituminous compositions to which the bisamide compounds according to the invention were added, exhibit a moderate and favorable change of the aging indicators in an accelerated aging test between 25 h and 48 h, unlike the comparative compositions.