DESC:FIELD OF INVENTION

The present invention relates to a polymer modified bituminous formulation comprising 0.1 to 10 wt. % of a reactive polymer, up to 5 wt. % of a plastomer, up to 5 wt. % of an elastomer, 0.001 to 6.0 wt. % of a cross linking agent, and 80 to 98 wt. % of bitumen, wherein the weight percentages are based upon the weight of the polymer modified bituminous formulation. The present invention also provides a process for preparing a polymer modified bituminous formulation. This invention also relates to an improved polymer modified bituminous formulations. Particularly the invention provides bituminous formulations modified by the addition of reactive polymers of different chemistry and different cross linkable agents.

BACKGROUND OF THE INVENTION
Bitumen has been defined as a colloidal mixture of hydrocarbons in which asphlatenes are dispersed into an oily matrix of maltenes and surrounded by a shell of resins whose thickness depends on temperature. Some of the specific properties of bitumen such as impermeability, ductility, adhesivity or resistance to the effect of weathering, chemicals etc have been explained using such model of bitumen. These are the remarkable properties, which for centuries have made bitumen a material of choice for many applications such as road and highway pavements construction, roofing membranes, sealant etc.
Bitumen generally behaves as a visco-elastic material at usual in-service temperatures, however, with ever increasing traffic loads and volume of vehicles, the life time of pavements gets reduced considerably. The quality of conventional bitumen has not been found satisfactory in conditions such as extreme temperatures, severe temperature fluctuations between day and night, application of heavy loads, climatic conditions such as ingress of moisture, mixing process and the temperatures used in the field etc. The high mixing temperatures (>180oC) during processing, may for example result into “primary” aging of the binder. The most commonly observed distresses, directly attributable to binder quality in roads, are rutting i.e., permanent deformation in the form of ruts or corrugations and thermal cracking which includes emergence of fractures in the roads due to lack of flexibility at low temperatures. The technical properties of bitumen, therefore have a significant effect on the performance of the resulting blend of bitumen with aggregates.
Traditionally, the performance of bitumen has been improved either through modified refining processes e.g. Multi-grade Bitumen (MB) or through utilization of certain performance additives. Multi-grade bitumen (MB) developed by Indian Oil Corporation disclosed in Indian Patent Number 191323, is an example of improving bitumen quality through improved refining process. MB is purely a blend of crude distillates with defined chemical components. It exhibits better rutting resistance (RR) at high temperature and better resistance toward the low temperature cracking in comparison to conventional bitumen. MBs also show good elastic properties which allow it to withstand fatigue at normal and intermittent temperatures. It has been reported that by using MB, pavement life can be extended by 40 %.
Use of additives to improve bitumen performance has been a common industrial practice since long. For overcoming potential deficiencies in bitumen, processing with specific performance enhancers has been reported. These include selection of suitable additive, blending it with a polymer and modifications through chemical reactions. A number of additives have been tried such as anti-stripping chemicals, antioxidants, sulphur, Polyphosphoric acid (PPA), lime, several aminic compounds etc with varying results. PPA alone when blended with unmodified bitumen is known to improve the high-temperature behavior of bitumen binders.
Polymers either virgin or waste have been extensively used for polymer modified bitumen in recent days which has made it possible to improve the performance of bituminous pavements under severe conditions of service such as extreme temperature variations and ever increasing vertical stresses and shear actions. Currently, the most commonly used polymer for bitumen modification is the SBS followed by other polymers such as styrene butadiene rubber (SBR), ethylene vinyl acetate (EVA) and polyethylene. Other elastomeric polymers being used are natural rubber, poly butadiene, butyl rubber, poly chloroprene, synthetic poly isoprene, nitrile silicone rubber etc. SBS, being elastomer, improves the desired properties including the elasticity of bitumen and therefore globally used for bitumen modification in large volume at present. However bitumen containing SBS being thermodynamically unstable in nature, shows some serious problems such as early phase separations when stored at high temperature, tendency to degrade on exposure to heat, oxygen, and UV light etc. These conditions generally lead to undesirable ageing of bitumen and polymer degradation, thus effecting overall performance of the blend. SBS also has some drawbacks like its insolubility in the bitumen during storage unless the mixture is subjected to the proper mixing on a continuous basis. Some plastomeric polymers have also been used but their performance is marginally inferior due to lack of desired elasticity properties.
Such observations have led to research studies for improving the modified bitumen properties through use of novel additives and other polymers. Some polymers called “Reactive polymers” have also been considered as novel bitumen modifiers which may improve bitumen polymer compatibility and also reduce the quantity of additive required. These reactive polymers are known to perform via forming chemical bonds with some bitumen molecules thus improving the mechanical behavior, storage stability and temperature susceptibility of the resulting binder. Cortizo et al studied the effect of addition of minerals such as montmorillonite (MMT), vermiculite (VMT), and kaolinite clay (KC) and has reported improvement in thermal, mechanical and barrier properties. Addition of MMT to SBS modified bitumen was also reported to increase both softening point and viscosity although there was decrease in the values of ductility.
J.F. Masson reported that Polyphosphoric acid (PPA), a short chain reactive oligomer when used in appropriate ratio, helps blended bitumen in improving its high temperature characteristics. Roghanizad studied the rheological behavior of bitumen containing 5% precipitated calcium carbonate coated by a thin layer of a polymeric compound and demonstrated that it increases the rutting resistance, storage ability and prevents the agglomeration of asphaltene particles.
Memon G.M` prepared chemically modified crumb rubber asphalt (CMCRA) through chemical treatment with hydrogen peroxide of the crumb rubber which resulted in improved elastic recovery property of the bitumen and better performance under different environmental and weather conditions. H. Ozen et al has reported two reactive polymers namely ethylene terpolymer (SRETP) and ethylene terpolymer (ETP) to improve features of 60/70 penetration grade modified bitumen used on highways.
Giovanni Polacco studied the viscosity functions of bitumen blended with polymers such as styrene-butadiene-styrene (SBS), ethylene vinylacetate (EVA) and reactive polymer “Ethylene terpolymers” (RET) at different temperatures in steady-state rate sweep tests. M.J. Martín-Alfonso reported the effect of processing temperature on the reaction between bitumen compounds and an isocyanate-based reactive polymer, synthesized by reaction of polymeric MDI (4,4'-diphenylmethane diisocyanate) with a low molecular weight polyethylene-glycol(PEG). The existence of an optimum processing temperature for formation of a polymer–bitumen network, reaction ability and polymer thermal degradation was reported.
Golzin Yadollahi recently showed the use of reactive polymer polyoctenamer in 4.5% concentration along with 1% PPA in Bitumen modified with crumb rubber (CRMB), resulting in significant improvement in the tackiness properties of the blend. Crumb Rubber (CR) has been used as an additive in asphalt mixes since the 1930s. CRMB is known to improve performance of asphalt mixture with respect to thermal susceptibility, elastic behavior, fatigue cracking resistance and aging stability. It is being used extensively because of its relatively lower cost and potential advantage of environment protection as CR is derived from used tyres available in large scale. CR with polyoctenamer has been reported to produce a uniform, low tack, rubber-like composite which improves the performance of pavement at high temperature conditions and rutting.
Due to these reasons, studies on PMBs with different chemistry polymers continue globally in several academic and industrial R&D centers. The proposed invention is an attempt to overcome the drawbacks in the present art.
SUMMARY OF THE INVENTION
Accordingly the present invention provides a polymer modified bituminous formulation comprising:
0.1 to 10 wt. % of a reactive polymer;
up to 5 wt. % of a plastomer;
up to 5 wt. % of an elastomer;
0.001 to 6.0 wt. % of a cross linking agent; and
80 to 98 wt. % of bitumen,
wherein the weight percentages are based upon the weight of the polymer modified bituminous formulation.

Another embodiment of the present invention provides a process for preparing a polymer modified bituminous formulation, wherein the process comprising the steps of:
(a) heating plastomer at a temperature in the range of 110 to 190 oC, heating of elastomer at a temperature in the range of 110 to 200 oC and heating reactive polymer at a temperature in the range of 100 to 190 oC;
(b) adding up to 5 wt.% of the heated plastomer, up to 5 wt.% of the heated elastomer and 0.1 to 5 wt.% of the heated reactive polymer to obtain a polymer reaction mixture;
(c) adding 0.001 to 2 wt. % of a cross linking agent to the polymer reaction mixture followed by intense mixing in a high speed mechanical mixer to obtain a polymer-cross linking reaction mixture;
(d) heating bitumen to a temperature in the range of 110 to 200 oC; and
(e) mixing the polymer-cross linking reaction mixture to the heated bitumen with agitation adequate to disperse the polymer-cross linking reaction mixture throughout the heated bitumen to obtain a polymer modified bituminous formulation.

DETAILED DESCRIPTION OF THE INVENTION

While the invention is susceptible to various modifications and alternative forms, specific embodiment thereof will be described in detail below. It should be understood, however that it is not intended to limit the invention to the particular forms disclosed, but on the contrary, the invention is to cover all modifications, equivalents, and alternatives falling within the scope of the invention as defined by the appended claims.
It is to be understood that the appended claims are not limited to express and particular compositions or methods described in the detailed description, which may vary between particular embodiments which fall within the scope of the appended claims. With respect to any Markush groups relied upon herein for describing particular features or aspects of various embodiments, it is to be appreciated that different, special, and/or unexpected results may be obtained from each member of the respective Markush group independent from all other Markush members. Each member of a Markush group may be relied upon individually and or in combination and provides adequate support for specific embodiments within the scope of the appended claims.
The method and the system of the present invention centre around the innovative idea of producing reactive polymer based modified bituminous formulation with improved performance properties by varied combinations of plastomers and elastomers and certain cross linking agents. The invention explores the use of and method of producing some polymers called “Reactive polymers” as novel bitumen modifiers which may improve bitumen polymer compatibility and also reduce the quantity of additive required. These reactive polymers are known to perform via forming chemical bonds with some bitumen molecules thus improving the mechanical behavior, storage stability and temperature susceptibility of the resulting binder.
Various plastomeric polymers including, but not limited to, Polyoctenamer polymer, polyethylene, polypropylene, polystyrene, polyvinyl chloride, Polyacetal, Polyacrylates, Polyamide, polycarbonate, polytetrafluorethylene have been explored for use. Certain cross linking agent readily initiate cross linking and make the formulation behave like elastomeric polymer modified bitumen. Other such polymers are styrene-butadiene styrene, Radical SBS, styrene- butadiene random co-polymer (SBR), ethylene vinyl acetate, oxidized polyethylene, ethylene propylene co-polymers, ethylene propylene diene (EPDM) terpolymers, polyisoprene, LLDPE, HDPE, and combinations thereof.
Further, combinations of plastomer and elastomer polymer additives have also been used. Examples of terpolymers include, but donot limit to ethylene/propylene/diene (EPDM) and ELVALOY, ethylene-vinyl-acetate (EVA) polymers, ethylene-methacrylate (EMA) polymers, epoxy resins, natural rubbers, polybutadiene and polyisoprene.
The invention also discloses a new method of producing “reactive polymer” based modified bitumen formulation from bitumen, polymer and adding additives. The resulted formulation posses desired physical and morphological properties. Polymers used in this group belong to but not limited to polymers such as ethylene terpolymer (SRETP), ethylene terpolymer (ETP), Isocyanate-based reactive polymer, synthesized by reaction of polymeric MDI (4,4'-diphenylmethane diisocyanate) with a low molecular weight polyethylene-glycol(PEG).), trans-polyoctenamer rubber.
The invention demonstrates that a polymer based modified bitumen, which as such does not meet the required performance characteristics, shows a remarkable change in its properties when blended with a small percentage of cross linking agent. The cross linking agents have significantly improved not only bitumen polymer compatibility but also reduced the quantity of polymer additive required. These reactive polymers are known to perform via forming chemical bonds with some bitumen molecules thus improving the mechanical behavior, storage stability and temperature susceptibility of the resulting binder.
The invention further demonstrate the suitability of various cross linking agents which can interact with the functionality of the reactive polymers and help in significantly improving the elastic recovery of the bituminous formulation without changing its core and critical properties required for high performance of bitumen for flexible pavements. Additives used in this group belong to but not limited to elemental sulfur, hydrocarbyl polysulfides, dithiocarbamates, sulfur containing oxazoles, thiazole derivatives, sulfur-donor vulcanization accelerators, non-sulfur donor vulcanization accelerators such as ally sillylating agent, peroxides, and combinations thereof.
In certain embodiments, the amount of crosslinking agent added to the paving composition is at least an amount of polymer added to the asphalt to achieve desired performance characteristics in the polymer-modified asphalt. Preferably, the amount of crosslinking agent added should not greatly exceed a useful amount, as the addition of overload crosslinking agent increases the cost of bituminous concrete production and may result in inferior performance or properties. Thus, the amount of crosslinking agent added is at least about 0.001 wt %, but does not exceed about 6.0 wt %, of the polymer-modified bitumen.
The present invention also provides a method of preparing an improved cross-linked, polymer-modified asphalt composition comprising bitumen, a crosslinkable polymer, a plastomer and a cross linking agent.
In accordance with one of the embodiments of the invention, polymer-modified bitumen is prepared by heating and adding to an appropriate quantities of plastomer and polyoctenomer then adding cross linking agent followed by intense mixing in a high speed mechanical mixer.
Bitumen is heated to a temperature sufficient for mixing purposes. Polymer and cross linking agent, are typically introduced into the feed of bitumen with agitation adequate to disperse the additives throughout the bitumen. i e about 170oC. In certain embodiments, the temperature range is 140- 200° C. Mixing times will vary and can be as long as several hours or more or as little as a few minutes or less, as long as the additives are adequately dispersed throughout the asphalt. Some combinations of bitumen and elastomer polymer may be mixed easily, while others require high shear milling. In certain embodiments, high shear mixing is used to mix the bitumen during at least a portion of the mixing after the polymer is added. In certain embodiments, low shear mixing is used at some point to mix the bitumen and plastomer after addition of the crosslinking agent.
More particularly the present invention provides a polymer modified bituminous formulation comprising
0.1 to 10 wt. % of a reactive polymer;
up to 5 wt. % of a plastomer;
up to 5 wt. % of an elastomer;
0.001 to 6.0 wt. % of a cross linking agent; and
80 to 98 wt. % of bitumen,
wherein the weight percentages are based upon the weight of the polymer modified bituminous formulation.

In one embodiment of the present invention provides a polymer modified bituminous formulation, wherein the reactive polymer is selected from the group comprising of Polyoctenamer polymer, Polyphosphoric acid (PPA), Synthetic Reactive Ethylene terpolymer (SRETP) and ethylene terpolymer (ETP), 4,4'-diphenylmethane diisocyanate (MDI) with polyethylene-glycol (PEG), Polyacrylates and combination thereof.
Another embodiment of the present invention provides a polymer modified bituminous formulation, wherein the plastomer is selected from the group comprising of Polyethylene, Polypropylene, Polystyrene, Polyvinyl Chloride, Polyacetal, Polyacrylates, Polyamide, Polycarbonate, Polytetrafluorethylene, Ethylene-Vinyl-Acetate (EVA), Ethylene-Methacrylate, Ethylene Propylene Diene (EPDM), Elvaloy and combination thereof.
Another embodiment of the present invention provides a polymer modified bituminous formulation, wherein the elastomer is selected from the group comprising of Styrene-Butadiene Styrene, Styrene Ethylene Butadiene, Styrene, Natural Rubber (NR), Styrene-Butadiene Rubber, Neoprene Latex, Latex (SBR), Styrene-Butadiene Block Copolymers (SB), Poly Butadiene, Butyl Rubber, Poly Chloroprene, Synthetic Poly Isoprene, Nitrile Silicone Rubber and combinations thereof.
Another embodiment of the present invention provides a polymer modified bituminous formulation, wherein the cross linking agent is selected from the group comprising of elemental sulfur, hydrocarbyl polysulfides, dithiocarbamates, sulfur containing oxazoles, thiazole derivatives, sulfur-donor vulcanization accelerators, non-sulfur donor vulcanization accelerators and combinations thereof.
Another embodiment of the present invention provides a polymer modified bituminous formulation, wherein the non-sulfur donor vulcanization accelerators is selected from the comprising of ally sillylating agent, peroxides, and combinations thereof.
Another embodiment of the present invention provides a polymer modified bituminous formulation wherein the bitumen comprises 6 to 23 wt. % of saturates, 32 to 59 wt. % of aromatics, 23 to 30 wt. % of resins and 9 to 21 wt. % of as asphaltenes.
The present invention provides a process for preparing a polymer modified bituminous formulation, wherein the process comprising the steps of:
(a) heating plastomer at a temperature in the range of 110 to 190 oC, heating of elastomer at a temperature in the range of 110 to 200 oC and heating reactive polymer at a temperature in the range of 100 to 190 oC;
(b) adding up to 5 wt.% of the heated plastomer, up to 5 wt.% of the heated elastomer and 0.1 to 5 wt.% of the heated reactive polymer to obtain a polymer reaction mixture;
(c) adding 0.001 to 2 wt. % of a cross linking agent to the polymer reaction mixture followed by intense mixing in a high speed mechanical mixer to obtain a polymer-cross linking reaction mixture;
(d) heating bitumen to a temperature in the range of 110 to 200 oC; and
(e) mixing the polymer-cross linking reaction mixture to the heated bitumen with agitation adequate to disperse the polymer-cross linking reaction mixture throughout the heated bitumen to obtain a polymer modified bituminous formulation.
In one of the preferred embodiment the present invention provides a polymer modified bituminous formulation comprising
0.5 to 2 wt. % of a reactive polymer;
up to 3 wt. % of a plastomer;
up to 3 wt. % of an elastomer;
0.001 to 6.0 wt. % of a cross linking agent; and
92 to 98 wt. % of bitumen,
the weight percentages are based upon the weight of the polymer modified bituminous formulation; wherein reactive polymer is selected from the group comprising of polyoctenamer, Polyphosphoric acid (PPA), Synthetic Reactive Ethylene terpolymer (SRETP) and ethylene terpolymer (ETP); the plastomer is selected from the group comprising of polystyrene, polyethylene, Polypropylene, Polycarbonate, Polytetrafluorethylene; the elastomer is selected from the group comprising of Styrene-Butadiene Styrene, Styrene Ethylene Butadiene, Natural Rubber (NR), Synthetic Poly Isoprene, Nitrile Silicone Rubber; the cross linking agent is selected from the group comprising of elemental sulphur, sulfur containing oxazoles, thiazole derivatives.
In one of the preferred embodiment the present invention provides a polymer modified bituminous formulation comprising
1 to 5 wt. % of a reactive polymer;
1 to 5 wt. % of a plastomer;
up to 3 wt. % of an elastomer;
0.001 to 6.0 wt. % of a cross linking agent; and
92 to 98 wt. % of bitumen,
the weight percentages are based upon the weight of the polymer modified bituminous formulation; wherein reactive polymer is selected from the group comprising of 4,4'-diphenylmethane diisocyanate (MDI) and polyethylene-glycol (PEG), Polyacrylates Polyoctenamer; the plastomer is selected from the group comprising of Ethylene-Vinyl-Acetate (EVA), Ethylene-Methacrylate, Ethylene Propylene Diene (EPDM), Polyvinyl Chloride; the elastomer is selected from the group comprising of Styrene-Butadiene Rubber, Neoprene Latex, Latex (SBR), Styrene-Butadiene Block Copolymers (SB), Poly Butadiene, Butyl Rubber, Poly Chloroprene; and the cross linking agent is selected from the group comprising of hydrocarbyl polysulfides, dithiocarbamates, sulfur-donor vulcanization accelerators, elemental sulphur.
In one embodiment of the present invention provides a polymer modified bituminous formulation, wherein the plastomer is in the range of 0.0001 to 5 wt. % and elastomer is in the range of 0.0001 to 5 wt. %.
The present invention further discloses a reactive polymer based modified bituminous formulation (a polyoctenamer polymer with improved anti-stripping properties of a bituminous concrete mixture as demonstrated through various Physico-chemical tests such as Hot water immersion tests, and Retained Marshal Stability test. (Table 2 and Table 3) These tests confirm acceptability of developed product mixture as good antistripping characteristics and their performance well comparable to commercial PMB products, currently being used by oil industry.
The invented polymer-modified bitumen through use of novel additives has shown significant properties equivalent/comparable to SBS modified bitumen modified bitumen, particularly in terms of elastic recovery, low temperature characteristics, high temperature performance characteristics, improved storage stability test, retention of Marshall strength. rutting resistance antistripping properties and other performance properties.

Extensive laboratory studies have proved that such developed product under this invention complies the quality requirement as per relevant ASTM standards, SHRP performance grade and various Indian standards and has thus helped in evolving a suitable set of specs in countries like India.

The following examples are illustrative of the invention but not to be construed to limit the scope of the present invention.

Examples
Typical properties of bitumen used are given in Table 1 to 3, where Formulation A as examplory represents Polyoctenamer Modified Bitumen and Formulation – B represents Cross linked Polyoctenamer Modified Bitumen.

Table1: Physio Chemical Properties Of 80/100 Penetration Grade Bitumen

Properties
Neat Bitumen
Formulation A
Formulation B Referral specifications
Penetration250 C (100 G 5 S),0.1MM 88 68 66 IS1203/1978
Absolute Viscosity at (600C), Poise 1135 -------- ------- IS1206(PART2)
Kinematic Viscosity at 1350C(CST) 297 657 905.97 IS1206(PART3)
Softening Point in 0C 45.5 45.5 51 IS l205/1978
Ductility at 270C
(5 cm/min) 100+ ------- ------- IS 1208 : 1978 Min
Elastic Recovery (150C) in % 15% 38 70 ASTM D6084
Ductility after TFOT at 250C in cm 100+ ---------- ---------- IS 1208 : 1978 Min
Compositional Analysis (%) of neat bitumen ASTM D 2007
Saturates 6%
Aromatics 51%
Resins 24%
Asphaltene 19%

Table. 2 Hot water stripping test Result
Sample % covered area of Aggregate
Neat Bitumen 60
Formulations A 95
Formulations B 100

Table. 3 Marshall Stability Test

Formulations Stability (kN) % Increase in stability over neat bitumen Flow (mm) Marshall
quotient
(kN/mm) % Increase in MQ over neat bitumen Retained Marshall stability Flow (mm) in Retained Marshall stability
Neat Bitumen 14.82 - 3.29 4.50 - 10.15 3.66
Formulations A 25.19 41.16 3.34 7.54 40.31 18.71 3.11
Formulations B 25.63 42.17 3.59 7.13 36.88 18.15 2.87

The Table 4 discloses the examples 1-8 for a polymer modified bituminous formulation. Tests have been conducted for Penetration at 250C,1/10 mm, 5 sec.; Softening point, (R&B), 0C ; Elastic Recovery of half thread in ductilometer at 150C, Separation Test (Difference in softening point,(R&B), 0C; Performance Grade; DSR-Original Binder, G*/Sin d-Value (KPa) at 700C; DSR-(After-RTFO), G*/Sin d-Value(KPa) at 700C; BBR (After-RTFO) m-Value/Estimated Stiffness (MPa) at -18 0C of these examples 1-8 and their results are tabulated in below table 4.

Further, Table 5 discloses the preferred examples 9-20 for a polymer modified bituminous formulation. Tests have been conducted for Penetration at 250C,1/10 mm, 5 sec.; Softening point, (R&B), 0C ; Elastic Recovery of half thread in ductilometer at 150C, Separation Test (Difference in softening point,(R&B), 0C; Performance Grade; DSR-Original Binder, G*/Sin d-Value (KPa) at 700C; DSR-(After-RTFO), G*/Sin d-Value(KPa) at 700C; BBR (After-RTFO) m-Value/Estimated Stiffness (MPa) at -18 0C of these examples 9-20 and their results are tabulated in below table 5.

Table 4
PMB formulations Ex. 1 Ex.2 Ex.3 Ex.4 Ex.5 Ex.6 Ex.7 Ex. 8
Wt. % of reactive polymer 1 2 1.5 1 1 1 0.2 7
wt. % of a plastomer/ 3.5 3 5 4 4 0.8 5.8 2
wt. % of a elastomer/ 1.5 0.5 1 1 0.2 1.5 0.3 5
wt. % of a cross linking agent 0.5 0.1 0.2 0.002 0.02 0.2 0.7 1
wt. % of bitumen 94 94.4 92.3 93.998 94.78 96.5 93 85
Penetration at 250C,1/10 mm, 5 sec. 53 52 44 51 62 60 50 Unable to process
due to increase in the Elasticity and viscosity
Softening point, (R&B), 0C 67 55 69 53 50 63 70
Elastic Recovery of half thread in ductilometer at 150C, % 73 74 72 40 30 66 27
Separation Test (Difference in softening point,(R&B), 0C 2.5 2.3 2.6 2.1 1.8 2.4 1.6
Performance Grade PG-76 PG-76 PG-82 PG-70 PG-64 PG-70 PG-64 -
DSR-Original
Binder, G*/Sin d-
Value (KPa)
At 700C
4.15 4.39 5.8 1.91 1.18 2.89 0.91 -
DSR-(After-RTFO),
G*/Sin d-Value
(KPa) At 700C
6.82 7.35 8.69 3.46 2.20 4.64 1.39 -
BBR (After-RTFO)
m-Value/Estimated
Stiffness (MPa) at -18 0C - 0.301/295 0.265/389 0.304/327 0.308/267/ 0.311/343/ 0.324/242 -

Table 5
PMB formulations and its range Ex. 9 Ex. 10 Ex. 11 Ex. 12 Ex. 13 Ex. 14 Ex. 15 Ex. 16 Ex. 17 Ex. 18 Ex. 19 Ex. 20
Name of reactive polymer and its range (in wt. %) Polyoctenamer 0.5% Polyoctenamer 0.5% Polyoctenamer 0.5% Polyoctenamer 0.5% Polyoctenamer 1% Polyoctenamer 1% Polyoctenamer 1% Polyoctenamer 1% Polyoctenamer 1% Polyoctenamer 1% Polyoctenamer 1% Polyoctenamer 1%
Name of plastomer and its range (in wt. %) 0.005 % Polystyrene 0.3% Polystyrene 0.025% Polystyrene 0.3% Polystyrene Polyethylene in 2% Polyethylene in 2% Polystyrene in 2% Polystyrene in 2% EVA in 2% EVA in 2% Polystyrene in 1% Polystyrene in 1%
Name of elastomer and its range (in wt. %) SBS in 2% SBS in 2% SBS in 3% SBS in 3% 0.3% SBS 0.03% SBS 0.15% SBS 0.008% SBS 0.0789% SBS 0.023% SBS SBS in 1% SBS in 1%
Name of cross linking agent and its range (in wt. %) elemental sulfur in 0.1% elemental sulfur in 0.5% elemental sulfur in 0.1% elemental sulfur in 0.5% elemental sulfur in 0.1% elemental sulfur in 0.5% elemental sulfur in 0.1% elemental sulfur in 0.5% elemental sulfur in 0.1% elemental sulfur in 0.5% elemental sulfur in 0.1% elemental sulfur in 0.5%
itumen and its range (in wt. %) Bitumen in 97.4% Bitumen in 97% Bitumen in 96.4% Bitumen in 96 % Bitumen in 96.9% Bitumen in 96.5% Bitumen in 96.9% Bitumen in 96.5% Bitumen in 96.9% Bitumen in 96.5% Bitumen in 96.9% Bitumen in 96.5%
Penetration at 250C,1/10 mm, 5 sec. 60 54 50 45 57 50 52 48 46 39 56 53
Softening point, (R&B), 0C 55 56 64 70 51 53 53.5 56 59 61 55 57.5
Elastic Recovery of half thread in ductilometer at 150C, % 67 70 73 78 53 56 54 60 61 63 65 68
Separation Test (Difference in softening point,(R&B), 0C 0.8 0.6 1 1 2.8 2.5 0.6 0.5 3 2.8 1.2 1
Performance Grade PG-70 PG-70 PG-70 PG-76 PG-70 PG-76 PG-70 PG-70 PG-70 PG-76 PG-76 PG-76
DSR-Original Binder, G*/Sin d-Value (KPa) 3.12 3.56 4.27 4.79 1.13 2.39 1.12 1.49 2.3 4.12 3.01 3.51
DSR-(After-RTFO), G*/Sin d-Value (KPa) 4.01 4.21 5.12 6.32 3.09 4.69 1.89 2.2 4.41 6.89 5.31 5.76
BBR(After-RTFO) (at -80C
m-Value/Estimated Stiffness (MPa) 0.298 / 252 0.308 / 229 0.349 / 189 0.351 / 175 0.306 / 243 0.314 / 256 0.324 / 220 0.240 / 383 0.304 / 270 0.295 / 286 0.300 / 259 0.314 / 321

,CLAIMS:We Claim:
1. A polymer modified bituminous formulation comprising
0.1 to 10 wt. % of a reactive polymer;
up to 5 wt. % of a plastomer;
up to 5 wt. % of an elastomer;
0.001 to 6.0 wt. % of a cross linking agent; and
80 to 98 wt. % of bitumen,
wherein the weight percentages are based upon the weight of the polymer modified bituminous formulation.

2. The polymer modified bituminous formulation as claimed in claim 1, wherein the reactive polymer is selected from the group comprising of Polyoctenamer polymer, Polyphosphoric acid (PPA), Synthetic Reactive Ethylene terpolymer (SRETP) and ethylene terpolymer (ETP), 4,4'-diphenylmethane diisocyanate (MDI) with polyethylene-glycol (PEG), Polyacrylates and combination thereof.

3. The polymer modified bituminous formulation as claimed in claim 1, wherein the plastomer is selected from the group comprising of Polyethylene, Polypropylene, Polystyrene, Polyvinyl Chloride, Polyacetal, Polyacrylates, Polyamide, Polycarbonate, Polytetrafluorethylene, Ethylene-Vinyl-Acetate (EVA), Ethylene-Methacrylate, Ethylene Propylene Diene (EPDM), Elvaloy and combination thereof.

4. The polymer modified bituminous formulation as claimed in claim 1, wherein the elastomer is selected from the group comprising of Styrene-Butadiene Styrene, Styrene Ethylene Butadiene, Styrene, Natural Rubber (NR), Styrene-Butadiene Rubber, Neoprene Latex, Latex (SBR), Styrene-Butadiene Block Copolymers (SB), Poly Butadiene, Butyl Rubber, Poly Chloroprene, Synthetic Poly Isoprene, Nitrile Silicone Rubber and combinations thereof.

5. The polymer modified bituminous formulation as claimed in claim 1, wherein the cross linking agent is selected from the group comprising of elemental sulfur, hydrocarbyl polysulfides, dithiocarbamates, sulfur containing oxazoles, thiazole derivatives, sulfur-donor vulcanization accelerators, non-sulfur donor vulcanization accelerators and combinations thereof.

6. The polymer modified bituminous formulation as claimed in claim 5, wherein the non-sulfur donor vulcanization accelerators is selected from the comprising of ally sillylating agent, peroxides, and combinations thereof.

7. The polymer modified bituminous formulation as claimed in claim 1 wherein the bitumen comprises 6 to 23 wt. % of saturates, 32 to 59 wt. % of aromatics, 23 to 30 wt. % of resins and 9 to 21 wt. % of as asphaltenes.

8. A process for preparing a polymer modified bituminous formulation, wherein the process comprising the steps of:
(a) heating plastomer at a temperature in the range of 110 to 190 oC, heating of elastomer at a temperature in the range of 110 to 200 oC and heating reactive polymer at a temperature in the range of 100 to 190 oC;
(b) adding up to 5 wt.% of the heated plastomer, up to 5 wt.% of the heated elastomer and 0.1 to 5 wt.% of the heated reactive polymer to obtain a polymer reaction mixture;
(c) adding 0.001 to 2 wt. % of a cross linking agent to the polymer reaction mixture followed by intense mixing in a high speed mechanical mixer to obtain a polymer-cross linking reaction mixture;
(d) heating bitumen to a temperature in the range of 110 to 200 oC; and
(e) mixing the polymer-cross linking reaction mixture to the heated bitumen with agitation adequate to disperse the polymer-cross linking reaction mixture throughout the heated bitumen to obtain a polymer modified bituminous formulation.

9. A polymer modified bituminous formulation comprising
0.5 to 2 wt. % of a reactive polymer;
up to 3 wt. % of a plastomer;
up to 3 wt. % of an elastomer;
0.001 to 6.0 wt. % of a cross linking agent; and
92 to 98 wt. % of bitumen,
the weight percentages are based upon the weight of the polymer modified bituminous formulation;
wherein reactive polymer is selected from the group comprising of polyoctenamer, Polyphosphoric acid (PPA), Synthetic Reactive Ethylene terpolymer (SRETP) and ethylene terpolymer (ETP);
wherein the plastomer is selected from the group comprising of polystyrene, polyethylene, Polypropylene, Polycarbonate, Polytetrafluorethylene;
wherein the elastomer is selected from the group comprising of Styrene-Butadiene Styrene, Styrene Ethylene Butadiene, Natural Rubber (NR), Synthetic Poly Isoprene, Nitrile Silicone Rubber;
wherein the cross linking agent is selected from the group comprising of elemental sulphur, sulfur containing oxazoles, thiazole derivatives.

10. A polymer modified bituminous formulation comprising
1 to 5 wt. % of a reactive polymer;
1 to 5 wt. % of a plastomer;
up to 3 wt. % of an elastomer;
0.001 to 6.0 wt. % of a cross linking agent; and
92 to 98 wt. % of bitumen,
the weight percentages are based upon the weight of the polymer modified bituminous formulation;
wherein reactive polymer is selected from the group comprising of 4,4'-diphenylmethane diisocyanate (MDI) and polyethylene-glycol (PEG), Polyacrylates Polyoctenamer;
wherein the plastomer is selected from the group comprising of Ethylene-Vinyl-Acetate (EVA), Ethylene-Methacrylate, Ethylene Propylene Diene (EPDM), Polyvinyl Chloride;
wherein the elastomer is selected from the group comprising of Styrene-Butadiene Rubber, Neoprene Latex, Latex (SBR), Styrene-Butadiene Block Copolymers (SB), Poly Butadiene, Butyl Rubber, Poly Chloroprene; and
wherein the cross linking agent is selected from the group comprising of hydrocarbyl polysulfides, dithiocarbamates, sulfur-donor vulcanization accelerators, elemental sulphur.