PITCH COMPOSITIONS, METHODS AND USES THEREOF

Abstract

The present invention relates to a pitch composition comprising a mixture of: deasphalting pitch, which represents at least 50% by weight, and preferably at least 80% by weight, and preferentially at least 90% by weight, of the total weight of the composition, and a hydroxide XOH with X=Na or K, which represents from 0.001 to 1% by weight, of the total weight of the composition,
as well as the method of preparation and uses thereof, particularly in the field of road construction.

Claims

1. A pitch composition comprising a mixture of: deasphalting pitch, which represents at least 50% by weight, and preferably at least 80% by weight, and preferentially at least 90% by weight, of the total weight of the composition, and a hydroxide XOH with X=Na or K, which represents from 0.001 to 1% by weight, of the total weight of the composition.

2. The composition according to claim 1, comprising from 0.002 to 0.5% by weight, preferably from 0.01 to 0.5% by weight of hydroxide XOH with X=Na or K, the % being % by weight, relative to the total weight of the composition.

3. The composition according to claim 1, wherein the hydroxide XOH, with X=Na or K, forms particles which have a mean maximum size in the range from 10 to 100 μm, preferably in the range from 20 to 60 μm and/or which have a maximum size less than or equal to 100 μm, preferably less than or equal to 60 μm.

4. The composition according to claim 1, wherein the hydroxide XOH is soda.

5. The composition according to claim 1, having a penetration index determined according to standard EN 1427-Appendix B, greater than −1.5, preferably greater than or equal to −1.3.

6. The composition according to claim 1, having a needle penetration at 25° C., determined according to standard EN 1426, which falls within the range from 0 to 50 mm/10 and/or a ball and ring softening temperature, determined according to standard EN 1427, which falls within the range from 50 to 175° C.

7. The composition according to claim 1, further comprising a hydrocarbonated component CH, chosen from among hydrocarbonated oils, soft-grade bitumen, fluxed bitumen, fluidified bitumen, and mixtures thereof, said hydrocarbonated component CH preferably representing at the most 10% by weight, preferentially 0.1 to 10% by weight, in a more preferred manner 0.5 to 8% by weight, and even more preferably 1 to 5% by weight, of the total weight of the composition.

8. A method for preparing a pitch composition, comprising the following steps: a—having an initial pitch composition available, and b—incorporating a hydroxide XOH with X=Na or K, in an amount such that the amount of hydroxide XOH introduced represents 0.001 to 1% by weight, of the total weight of the final pitch composition obtained, the initial pitch composition comprising an amount such that the pitch represents at least 50% by weight, preferably at least 80% by weight, and preferably at least 90% by weight, of the total weight of the final pitch composition obtained.

9. The method according to claim 8, wherein in step b, a hydrocarbonated composition IC comprising from 15 to 50% by weight of the hydroxide XOH with X=Na or K is incorporated into the initial pitch composition, said composition IC comprising a hydrocarbonated component CH, preferably chosen from among hydrocarbonated oils, soft-grade bitumen, fluxed bitumen, fluidified bitumen and mixtures thereof.

10. The method according to claim 9, wherein, the hydroxide XOH, with X=Na or K, is present in the composition IC, in the form of particles which have a mean maximum size in the range from 10 to 100 μm, preferably in the range from 20 to 60 μm and/or which have a maximum size less than or equal to 100 μm, preferably less than or equal to 60 μm.

11. The method according to claim 1, wherein the incorporation of the hydrocarbonated composition IC into the initial pitch composition is carried out at a temperature in the range from 150 to 220° C., preferably in the range from 160 to 190° C. and/or with stirring in the range from 100 to 500 rpm, preferably in the range from 200 to 400 rpm and/or for a period of 10 to 180 minutes, preferably from 10 to 20 minutes.

12. A method of increasing a penetration index determined according to standard EN 1427-Appendix B of the composition obtained, and to obtain, in particular, a penetration index greater than −1.5, preferably greater than or equal to −1.3, of a composition comprising pitch representing at least 50% by weight, preferably at least 80% by weight, and preferentially at least 90% by weight, of the total weight of the composition, by introducing a hydroxide XOH with X=Na or K into the composition, in an amount representing from 0.001 to 1% by weight, preferably from 0.002 to 0.5% by weight, and preferentially from 0.01 to 0.5% by weight, of the total weight of the composition, the % by weights given for pitch and hydroxide being calculated relative to the total weight of the composition including the hydroxide.

13. A waterproof coating, a membrane or a seal layer prepared with a composition according to claim 1.

14. A method for preparing a mix, comprising hot mixing a composition according to claim 1 with aggregates, and possibly mineral and/or synthetic fillers.

15. A mix comprising the composition according to claim 1 mixed with aggregates, and possibly mineral and/or synthetic fillers.

16. A method for preparing an asphalt, comprising hot mixing a composition according to claim 1 with mineral and/or synthetic fillers.

17. An asphalt comprising a composition according to claim 1 mixed with aggregates, and possibly mineral and/or synthetic fillers.

18. A surface coat, a hot mix, a cold mix, a cold-poured mix, a grave-emulsion or a rolling layer, prepared with a composition according to claim 1 associated with aggregates and/or recycled milled material.

Description

EXAMPLES

[0147] a) Preparation of a Hydrocarbonated Composition IC

[0148] The sodium hydroxide pellets were ground to a fine powder, using a grinder IKA® A11 (IKA-Werke GmbH & Co) at 28 000 rpm, for around 30 seconds, Thus, the sodium hydroxide (NaOH) particles were obtained. Their maximum size measured from 20 particles under the microscope was around 50 μm. At the same time, 500 g of fluxed bitumen were heated at 50° C. in a reactor with a diameter of d=16 cm and stirring at 600 rpm with hotplate stirrer (diameter D of the active mechanical part), with D/d=0.4. The temperature was controlled using a thermostat. 95.24 g of powdered sodium hydroxide was put in suspension in fluxed bitumen and stirred; stirring was continued for 30 minutes. In the composition IC obtained, % by weight of NaOH was 16%, on the basis of the total weight of the composition IC obtained. The composition IC obtained was observed by microscopy under visible light, which showed that the soda was in the form of particles over 80% of which had a maximum size less than or equal to 50 μm.

[0149] b) Preparation of the Modified Pitch Composition

[0150] The composition IC prepared previously was heated to 50° C. maximum (as the viscosity of fluxed bitumen decreases at higher temperatures, this leads to a higher decantation rate for NaOH) under stirring in a reactor with a stirrer as described in section a) (D/d=0.4) at 600 rpm for homogenising.

[0151] In parallel, 2500 g of pitch were heated at 180° C. in a reactor and stirred using a stirrer such as described in section a) (D/d=0.4) close to 400 rpm to homogenise the pitch. The prepared composition IC was added directly to the pitch (3.23 g of composition IC per 100 g of pitch=3.13% by weight in the final pitch composition). At the end of the addition of composition IC, stirring was continued for 30 minutes.

[0152] The mixture continued to be stirred for 3 hours at 600 rpm. The temperature of the mixture was set not to exceed 170° C. Samples were removed from the reactor regularly to measure the RBT and Pene. Mixing was stopped when the two stabilised. Next, the mixture was cooled down to 160° C. and 5.04 g of the adhesion promoter H1 were added. Mixing was maintained for 20 minutes. In the final pitch composition, the % by weight of NaOH was 0.500%, the adhesion promoter H1 was 0.194% by weight and fluxed bitumen 2.623% by weight, on the basis of the total weight of the pitch composition.

[0153] Table 1 below gives RBT and Pene, before and after RTFOT+PAV, for the pitch alone and for the pitch composition according to the invention.

TABLE-US-00001 TABLE 1 Modified Ref. PITCH Invention PITCH H1 PITCH BRT DIN EN 1427 ° C. 64.8 64.6 65.2 Pene DIN EN 1426 mm/10 7 8 9 Penetration EN1427- — −1.6 −1.5 −1.2 index Appendix B Resistance to DIN EN 12607- RTFOT 1 + 14769 and PAV ageing RBT DIN EN 1427 ° C. 73.2 73.4 70.6 RBT Change DIN EN 1427 ° C. 8.4 8.6 5.4 Pene DIN EN 1426 mm/10 6 6 8 Pene DIN EN 1426 % 86 75 89 maintenance

[0154] These results show that the addition of soda makes it possible to obtain an increase in the penetration index. In particular, the penetration index obtained complies with the road construction properties as required by standard EN 1427-Appendix B. The value of −1.6, obtained in the absence of the incorporation of soda is too low and is not acceptable.

[0155] Moreover, as a supplement, the measurements carried out on a pitch modified solely by the addition of 0.194% by weight of adhesion promoter H1 (modified pitch H1) show that the stability TBA and Pene after RTFOT and PAV is less identical, possibly even less good, in the case of Pene, than that obtained for the reference pitch.