EP0529046A1

EP0529046A1 - Preparation of a light coloured petroleum binder

Info

Publication number: EP0529046A1
Application number: EP19920906702
Authority: EP
Inventors: Guy Leroy; Michel Ullmann
Original assignee: Gerland SA; BP PLC
Current assignee: Gerland SA; BP PLC
Priority date: 1991-03-15
Filing date: 1992-03-13
Publication date: 1993-03-03
Also published as: JPH05507960A; AU1543192A; FR2673947B1; AU649328B2; WO1992016580A1; FR2673947A1

Abstract

On prépare des liants faiblement colorés à base de pétrole et exempts d'asphaltènes en mélangeant un ou plusieurs polymères présentant une réticulation importante ou un poids moléculaire élevé avec un extrait aromatique tiré du pétrole et obtenu par extraction liquide-liquide d'un distillat dont le point d'extinction est situé dans une plage de 400 °C à 600 °C. On peut utiliser ces liants dans la production de granulats colorés pour la construction de voies de circulation ou de bâtiments.Weakly colored petroleum-based and asphaltene-free binders are prepared by mixing one or more polymers having a high crosslinking or a high molecular weight with an aromatic extract derived from petroleum and obtained by liquid-liquid extraction of a distillate, the extinction point is located in a range of 400 ° C to 600 ° C. These binders can be used in the production of colored aggregates for the construction of traffic lanes or buildings.

Description

Preparation of a l ight coloured petroleum binder

The present invention relates to a process for the preparation of light coloured petroleum binders free from asphaltenes, the light coloured binders so obtained and their use in the production of light coloured coated aggregate.

In this specification "aggregate" is graded mineral aggregate.

The use of coloured aggregate in the production of highway and urban road surfaces is particularly sought after at present. The coloured aggregate allow improvements in highway safety and in safety in towns, in particular for pedestrians, car drivers and cyclists in differentiating by colour passages for pedestrians, crossroads, cycle tracks and increasing the luminosity of certain transport routes which are feebly illuminated such as tunnels. Coloured aggregate equally allows the quality of life in towns to be improved by colouring pavements (sidewalks), pedestrian passages, squares, sports grounds with lively and varied colours.

A process of mak^'ing coloured aggregate is known starting with pigmentable bitumens with a low content of asphaltenes (around 5%) to which is added a mineral pigment. This process only allows aggregate of a red brick colour to be obtained; the other colours are impossible to obtain.

Another technique consists in applying to a coated aggregate obtained from a black bitumen a paint without a solvent. This process allows a variety of colours to be obtained. However, the resistance to abrasion, an essential characteristic of colouratior. in the mass, is not satisfactory. The applicant has discovered in a surprising fashion that in associating one or more polymers, highly cross-linked or of high molecular weight, with an aromatic petroleum extract obtained by liquid-liquid extraction with double column of a distillate with a cut point between 400 and 600*C there is obtained a light coloured petroleum binder allowing the production of coloured aggregate in a very large range of colourations in the mass and stable to ageing.

Furthermore, the light coloured petroleum binder free from asphaltenes so obtained has rheological properties equivalent or even superior to those of a conventional bitumen of the same grade, containing about 7-8% asphaltene.

The invention is thus for this object a process for the preparation of light coloured petroleum binders free from asphaltenes.

Another object of the invention exists in the production of coloured aggregate by the use of the product so obtained.

Other objects will appear in the light of the description and the examples which follow.

The process in accordance with the present invention consists essentially of blending one or several polymers, highly cross-linked or having a high molecular mass, with an aromatic extract of petroleum origin obtained by liquid-liquid extraction of a distillate with a cut point of 400-600'^>C.

The aromatic extract will generally be obtained by multiple extractions, normally a double column extraction in which the extraction is carried out in the same column twice or in two successive columns.

The aromatic extract in accordance with the invention has preferably a kinematic viscosity at 100^βC between 30 and 110 x 10^-(-^* m^/second and an aromaticity (according to ASTMD to 007) greater than 75%. It has more particularly a kinematic viscosity between 45 and 101 x 10^~-m-Vsecond and an aromaticity in the range 75-82%.

Polymers according to the present invention are selected preferably among: A) Highly cross-linked aromatic thermoplastic resins, which are uncoloured and are soluble in the majority of solvents, and having the following characteristics:

- Softening point (ring and ball ASTME - 28) greater than 75°C;

- Iodine number (ASTM 1959) less than 25;

- Acid number (DIN 51558) less than 0.1;

- Saponification index (DIN 51559) less than 3;

- Gardner colour index (50% in toluene) (ASTM 1544) less than 8;

B) Copolymers of ethylene/vinyl acetate comprising 5-45% by weight of vinyl acetate units and preferably less than 20% and a fluidity index in the range 0.1 to 600 and preferably between 100 and 200;

C) Atactic polypropylenes having a softening point (ring and ball ASTME - 28) greater than 120*C and a dynamic viscosity at 180^βC in the range 500 to 20,000 mPa.S.

The polymers defined above can be utilised either alone, or in the form of binary or ternary mixtures in association with the aromatic petroleum extract defined above. The polymer, or the mixtures of polymer according to the invention, are used in concentrations which are preferably in the range 10 and 40% by weight based on the total weight of the light coloured petroleum binder.

The aromatic petroleum extract as defined above is used in concentrations in the range 60-90% by weight.

The petroleum binder in accordance with the present invention which constitutes another object of the present invention is preferably prepared in bringing aromatic extract of petroleum origin to a temperature of the order of 106°C under low agitation, then by adding progressively the polymer or polymers during a period in the range between half hour and four hours, followed by a homogenisation of the mixture at 160^βC during about one and a half hours.

A particularly preferred method of preparation of the petroleum binder according to the invention consists in using an aromatic extract such as defined above having a kinematic viscosity at 100*C in the range 45-101 x 10^"-°mr/second and an aromaticity in the range 75-82%, with a mixture of polymers constituted from a ethylene/vinyl acetate copolymer having a fluidity index in the range 135-165 and a proportion between 17 and 19% by weight of vinyl acetate units, and of a thermoplastic aromatic resin such as defined above having a softening point greater than 150°C.

The applicant has found that the light coloured petroleum binders free from asphaltenes so obtained have rheological properties, in particular a plasticity interval, equal or superior to those of a conventional bitumen of the same grade.. In addition their stabilities for coating and storage are equivalent or superior to those of a conventional bitumen of the same grade.

Another object of the invention consists in the production of stable coloured coated aggregate obtained by classic mixing and compacting from 1) a light coloured petroleum binder according to the invention, 2) granulate material (aggregate), and 3) a mineral pigment.

The light coloured petroleum binders according to the present invention are particularly suitable for the production of coated aggregate because their adhesion to aggregate is excellent.

The coated aggregate so compared has a good mechanical resistance by the DURIEZ method. The colouration in the mass covers a large range of nuances going particularly from white to red in passing by greens and ochres. They are in addition stable to ageing.

The aggregates (granulates) used for the production of the coated chippings are selected among those generally used in highway construction.

The mineral pigments are selected as a function of the colour required and for the use envisaged for the coated aggregate.

The examples which follow serve to illustrate the invention without limiting it. EXAMPLE OF LIGHT COLOURED PETROLEUM BINDER

A light coloured petroleum binder containing 12.5% by weight of ethylene/vinyl acetate copolymer (EVA) having a fluidity index between 135 and 165 and a proportion of 17-19% by weight of vinyl acetate units, 12% by weight of aromatic thermoplastic polymer having a softening point greater than 150"C and 75.5% by weight of an aromatic petroleum extract having the following characteristics:

- Density 15"C: 1.0042

- Density 70'C: 0.9695

- Viscosity 100°C: 100.6 x 10"⁶m /s

- Flash point: 263*C (P.M.)

- Aniline point: 301"C

- Sulphur: 4.3% by weight

- Analysis ASTM D2007: Saturates 10.1% Aromatics 76.7% Polar 13.2%

- Refractive index: 20'C: 1.5690 68^βC: 1.5508

The above aromatic petroleum extract, is brought to 160^βC with gentle agitation. The aromatic thermoplastic resin in particle form is added over a period of time (15 minutes). After homogenisation, the pellets of EVA copolymer are added over a period of 15 minutes. The total homogenisation took place after 1 hour 30 minutes at 106-C. Rheoloeical Study of the Light Coloured Binder Obtained

The rheological characteristics, stability to storage according to the "toothpaste" test and its stability to coating (RTFOT) are compared to those of a conventional bitumen of grade 180/220. The results are indicated in the following table. Conventional

Light Binder of Bitumen

Nature of the Binder the Invention 180/220

Penetration, at 25^βC 1/10 mm 170 180/20

Softening Point 61.5 34/40

FRAASS -22 -21/-15

Stability on Storage

Variation in softening point High ^βC +1.5 +4.0

Low ^βC +2.0 +4.5

Ageing RTFOT

Remaining penetration % 86.0 65.0

Incr. softened *C 0.5 5.0

Variation Frass ^βC 0

(*) Storage stability by "toothpaste tube":

- 75 g of binder are run into a flexible toothpaste tube (dD=3 cm; h=16 cm) closed with removal of the air before cooling

- Storage temperature = 180°C during 3 days

- Measures of the characteristics of the upper and lower parts of the tube We have found that the plasticity interval, the storage stability and the stability to coating are improved by comparison with those of the conventional bitumen of the same grade determined according to the standards prescribed by the Societe d'Etudes Techniques des Routes et Autoroutes (SETRA).

Study of the DURIEZ Mechanical Resistance of Coated Materials obtained from Light Coloured Binder

A test for mechanical resistance by the DURIEZ method was carried out at three temperatures, namely 0^β, 18° and 50^βC on the following coated formulation (bituminous concrete 0/10 half grain):

- 0/2 mm 36%

- 2/6 mm 35%

- 6/10 mm 23% Granulometric.distribution:

Content in clear binder: 5.75 ppc (parts per 100 parts of aggregate).

The relationship of the resistance at 18"C in the simple compression test with immersion in water during 7 days in comparison with the resistance measured dry indicates the resistance to decoating of the binder.

The results obtained are indicated in the following table: DURIEZ Mechanical Resistance

Binder Light Binder SETRA Specification

Penetration 25°C

1/10 mm 170 180/220

Softening °C 61.5

Compacticity 91.7 91-95

Resistance R at 0" MPa 16 0.16 at 18° MPa 3.5 0.4 at 50° MPa 0.79 0.8

Resistance r at 18° MPa after 7 day immersion 2.7 > 0.3

r/R 0.77 > 0.75

The DURIEZ mechanical resistance of the coated aggregate of the invention satisfies the characteristics required by the Societe d'Etude Techniques des Routes et Autoroutes (SETRA). Study of the Adhesion to Aggregate

Coated aggregate are prepared in accordance with the following formulation:

- 5 g of light coloured petroleum binder, and 100 g of washed and dried 4/6 aggregate.

Coating is obtained by manual mixing by bringing the mixture to a temperature corresponding to a bitumen viscosity of 200 m.Pa.S. The product is covered with water (300 cm^). It is allowed to stand for 16 hours at 60*C.

The percentage of surface covered by the film of binder was 90% after immersion in water during 16 hours at 60°C.

These results for the adhesion to aggregate of the binder of the invention are in accordance with the characteristics required by SETRA.

Example of the Preparation of Coated Coloured Aggregate in the Laboratory

Using the light coloured binder of the example coated aggregate is prepared with the following formulation:

- Aggregate: 4/10 mm 45%

- Pigments: Mineral pigments of green ochre or red colour 1.5%

- Content in light coloured binder: 6 ppc (6 parts for 100 parts of chippings)

The aggregate, the clear binder and the pigment are mixed manually while bringing them to a temperature corresponding to a viscosity of the binder of 200 raPa.S.

300 g of coated aggregate is compacted with the MARSHALL rammer (about 15 blows) to obtain cylindrical samples with a diameter of 10 cm, thickness 1.5 cm and a degree of compaction of 96-98.

Coated aggregate of ochre, green and red colour stable to ageing is obtained.

Claims

Claims:

1. Process for the preparation of a light coloured petroleum binder free from asphaltenes, characterised in that one or more polymers, highly cross-linked or of high raolcular mass, are blended with an aromatic extract of petroleum origin obtained by liquid-liquid extraction of a distillate with a cut point of 400-600^βC.

2. Process according to Claim 1 wherein the extraction is a double column extraction.

3. Process according to either of Claims 1 or 2, characterised by the fact that the aromatic petroleum extract has a kinematic viscosity at .100°C between 30 and 110 x 10^~^m^/second and an aromaticity (ASTM D2007) greater than 75%.

4. Process according to Claim 3, characterised in that the aromatic extract has a kinematic viscosity at 100°C in the range 45 to 101 x 10~°m^/second and an aromaticity in the range 75 to 82%.

5. Process according to any one of Claims 1 to 4, characterised in that the polymer or polymers are used at concentrations in the range 10 to 40% by weight based on total weight of light coloured petroleum binder.

6. Process according to any one of Claims 1 to 5, characterised by the fact that the polymers are selected from:

A) Highly cross-linked aromatic thermoplastic resins, which are uncoloured and are soluble in the majority of solvents, and having the following characteristics: - Softening point (ring and ball ASTME - 28) greater than 75"C; - Iodine number (ASTM 1959) less than 25;

- Acid number (DIN 51558) less than 0.1;

- Saponification index (DIN 51559) less than 3;

- Gardner colour index (50% in toluene) (ASTM 1544) less than 8;

B) Copolymers of ethylene/vinyl acetate comprising 5-45% by weight of vinyl acetate units and preferably a proportion less than 20% and a fluidity index in the range 0.1 to 600 and preferably between 100 and 200;

C) Atactic polypropylenes having a softening point (ring and ball ASTME - 28) greater than 120°C and a dynamic viscosity at 180°C in the range 500 to 20,000 raPa.S; as well as their binary or ternary mixtures.

7. Process according to any one of Claims 1 to 6, characterised in that the aromatic petroleum extract is brought to a temperature of 160°C, and that the polymer or polymers are added progressively during a period of 30 minutes to 4 hours, and that the mixture is subsequently homogenised at 160°C during one and a half hours.

8. Process according to any one of Claims 1 to 7, characterised in that a) an aromatic petroleum extract as defined in Claim 3, b) an ethylene/vinyl acetate copolymer having a fluidity index between 135 and 165 and a proportion of vinyl acetate units comprised between 17 and 19% by weight, and c) an aromatic thermoplastic polymer such as defined in Claim 5 having a softening point greater than 150°C, are mixed together.

9. Light coloured petroleum binder free from asphaltenes having been obtained according to the process as defined in any one of Claims 1 to 8.

10. Use of light coloured petroleum binders according to Claim 9 for the preparation of stable coloured coated aggregate intended for highways or urban surfaces.

11. Process for the production of stable coated aggregate for highway or urban coatings characterised in that the petroleum binder of Claim 8 is mixed with the aggregate habitually used for highway construction in the presence of a minimal pigment and that a compacting step follows.

12. Stable coloured coated aggregate for highway or urban surfaces capable of being obtained according to a process defined in Claim 10.