DD147672A1 - METHOD FOR PRODUCING BITUMEN WITH IMPROVED UTILITY CHARACTERISTICS - Google Patents

Abstract

The invention relates to a process for improving the utility properties of road bitumen by additive. The improvement of ductility, ductility-temperature behavior and paraffin content of bitumen, especially from paraffin-rich feedstocks, is achieved by adding bitumen 0.1% to 5% alkylnaphthenate, higher fatty acid metal salts, fatty acid amines, polyolefin grafts, fatty acid backbone residues and combinations these compounds are added at temperatures between 393 and 493 K.

Description

Process for producing bitumen having improved utility properties

Field of application of the invention

The invention relates to a method for improving the utility value of road bitumen by the addition of additives,

Characteristic of the known technical solutions

As is known, a number of quality requirements are imposed on road construction bitumen, the fulfillment of which essentially depends on the composition of the crude oils used. Amongst other things, a content of macrocrystalline paraffins leads to a deterioration in the utility properties of the road construction binder. This deterioration of the bitumen properties manifests itself primarily in the reduction of ductility, adhesion and bond strength as well as in the change in the viscosity-temperature behavior (unsteady curve shape) ) compared to analogous bitumen with a low paraffin content «

The damaging effect of the bitumen paraffins depends on the forming crystal structure. While in the presence of microcrystalline paraffins, there is little effect on the utility characteristics of bitumen, the formation of macro-crystalline structures and their cross-linking causes a minute disturbance of the colloidal structure of the bitumen, caused by the weakening of the cohesive forces acting in the bitumen.

It is known that additives are used in the lubricating oil industry or in heating oil production, which reduce the pour point of these products by inhibiting the formation of macro-crystalline paraffins and their crosslinking, so that thereby have excreted microcrystalline paraffins only a minor influence on the lubricating oil properties , The additives used include primarily alkylnaphthenates, polyacrylates and siloxane copolymers in the concentration range from 0.2 % to 1.0% »

Possibilities to modify the crystal structure of the bitumen paraffins by adding additives, and thus to give the bitumen better utility properties, are barely reported in the literature. Studies in the CSSR show that additions of 2.5 % to 5.0 % atactic polypropylene at a paraffin content of 6.6 % cause an improvement in the ductility temperature behavior. US Pat. No. 3,303,149 describes the addition of paraffinic bitumen with <1 % ethylene vinyl acetate or ethylene ethyl acrylate copolymers, which causes an increase in ductility as well as an improvement in the viscosity-temperature behavior.

Object of the invention

It is an object of the invention to produce a bituminous road building compound having improved utility properties such as ductility, ductility temperature behavior and adhesion, especially from less suitable paraffin rich feedstocks.

Explanation of the essence of the invention

The invention is based on the object of preventing the formation of macrocrystalline paraffin structures and their crosslinking in bitumen at temperatures below their solidification point by adding suitable additives or combinations of additives.

It has been found that additions of 1.0% to 5, O% Polyolefingatsch, 0.1 to 3 ^ 0% metal salts of higher fatty acid amine eowie 0.3% to S ₄ O% of flow aids to increase the throughput rate of oil in the pipeline transport a substantial improvement in the utility properties, in particular the ductility, the adhesion to the rock and the ductility temperature behavior cause.

The use of these products also reduces the freeze-detectable paraffin content. The crystal-modifying effect was detected microscopically using a cooling table.

The application of the additives takes place both by mixing in the bitumen at temperatures between 393 K to 493 K.

and mixing time from 10 minutes to 60 minutes at the refinery as well as by addition during processing of the bitumen to the bituminous mix through the road construction,

embodiments

With reference to subsequent examples, the invention will be explained in more detail.

Example 3.

To a bitumen grade B 200 with a paraffin value of 2.3 % , 0.3 to 1.0 % of alkyl naphthenate was added and the following parameters were determined:

Addition % - 0.3 0.5 1.0

Paraffin number % 2.3 2 _? 3 2.2 1.8 Ductility 25 ⁰ C cm 76 90>100> 100 Adhesion 70 ⁰ C % 20 40 50 75

Example 2

Addition of 0.5 % to 2 ₄ 0 % aluminum stearate to B 200 with an increased paraffin content of 4.2%:

Addition % - 0.5 1.0 2.0

Paraffin number % 4.2 4.0 3.8 Ductility 25 ⁰ C cm 63 87>100> 100

Example 3

With the addition of 1 % polyethylene glycol or 1% Al stearate to a paraffin-rich bitumen (paraffin number 4.2 %) , the following values were determined in the ductility-temperature behavior:

additive did ⁰ C cm 5 Polyethylene Gatch Al stearate Ouktili 5 ⁰ C 17 at 10 ⁰ C 53 5 8th 15 ⁰ C 68 13 18 20 ⁰ C , 64 32 82 • 25 ° C 56 78 * > 100 30 kj 34 > 100 > 100 35 > 100 92 64 44

Claims (2)

invention claim A process for the production of bitumens having improved utility properties such as ductility, ductility temperature and paraffin content, especially of paraffin rich bitumen, characterized in that the bitumen contains 0.1 % to 5 % alkylnaphthenate, metal salts of higher fatty acids, fatty acid amines, polyolefin pitches, fatty acid distillation residues or combinations of these substances are added. 2 ", method according to point l _t characterized in that preferably 0.5 % alkyl naphthenate and / or 1.0 % aluminum stearate are added. 3 _e method according to item 1 and 2, characterized in that the incorporation of the additives at temperatures between 393 K to 493 K, preferably 413 K to 453 K occurs.