EA016187B1 - Method for producing bitumen modifier - Google Patents

Abstract

The invention relates to a method of producing bitumen modifiers based on regenerated auto-tire casing and other utilized rubber-containing materials. The inventive result is aimed at enhancing physico-mechanical properties of rubber-bituminous binding and composite materials based thereon, broadening temperature interval of plasticity, increasing frost resistance and stability to cyclic deformations at negative temperatures, improving vibro-absorbing properties of asphalt concrete and reducing power inputs. Said result is characterized in that in the method of producing bitumen modifier comprising mixing rubber crumb with a polymer material, rubber powder of 100-300 mkm fraction is used as rubber crumb, wherein polyvinyl ether with molecular mass 250000-400000 units is used as the polymer material and additionally comprises alkylbetaine and/or cocamidopropylbetaine (CC) and alkylbenzyldimethylammonium chloride (CC) with the following component ratio, wt%:

Description

The invention relates to the field of producing modifiers of bitumen based on regenerated car tires and other recycled rubber materials.

A known method for producing a rubber-containing polymer bitumen modifier is that fuel oil is added to a bitumen preheated to 160 ° C, mixed, then rubber crumb mixed with building lime is introduced, and heated for 3-4 hours to swell the crumb at the same temperature ( 160 ° C). Secondary polyethylene is combined in a separate portion with bitumen in a ratio of 1: 1 at a temperature of 150-160 ° C. Bitumen is fed gradually with stirring into preheated polyethylene. The prepared mixture of polyethylene in bitumen is mixed at 150-160 ° C with the previously prepared mixture (bitumen + fuel oil + crumb rubber + building lime), then everything is fed into the extruder and granulated together. The components are taken in the following ratio, wt.%:

bitumen BND 60/90 fuel oil brand 100 rubber crumb secondary polyethylene building lime

47-62

2-5

30-35

3-7

3-6 (RF patent No. 2266934, class С08Ь 95/00, 2005)

This modifier does not allow to obtain a binder with a brittle temperature below -23 ° C. A known method of producing a bitumen-rubber composition, including rubber crumb, an active modifier and an astringent - bitumen. As an active modifier, a compound from a series of parabanoic acids is used, which is capable of generating chemically active particles and isolated gas microinclusions in the composition during decomposition, and is also able to regulate the process of destruction and crosslinking of particles in bitumen without noticeable segregation in the following ratio of components, wt.%:

rubber crumb 5-15 row of parabanoic acids and their derivatives 1-2 bitumen else (RF patent No. 2223990, CL C08 95/00, 2004)

The specified method does not allow to increase the physicomechanical characteristics of rubber-bitumen binders and composite materials based on them (brittle temperature -24 ° C).

A known method of preparing a rubber-bitumen binder for surface treatment of road surfaces, including mixing bitumen with a heat-treated mixture of rubber crumb with a plasticizer in a ratio of 1.0: (0.7-1.8) at 150-180 ° C, heat treatment of a mixture of rubber crumb with a plasticizer is carried out first, at 190-220 ° C for 0.5-1.0 hours, then at 240-260 ° for 0.5-4.0 hours, and mixing with bitumen is carried out with the additional introduction of a builder in the ratio, wt.% :

the specified mixture 10,0-20,0 structure-forming agent 1,2-12,0 bitumen else

Shale oil, or anthracene oil, or an extract for the selective purification of oils, are used as a plasticizer. Polyethylene wax, or elemental sulfur, or ammonium nitrate is used as a structurant (AS USSR No. 1289872, class C08 95/00, 1987).

This method does not allow to obtain a modifier with high physical and mechanical characteristics, and the product produced on its basis has an insufficiently low brittle temperature of -17 ° C. In addition, the production of the modifier is characterized by high energy consumption, since the heat treatment of a mixture of rubber crumb with a plasticizer is carried out first at 190-220 ° C for 0.51.0 hours, then at 240-260 ° C for 0.5-4.0 hours .

The objective of the invention is to develop a method for producing a bitumen modifier for the production of bitumen-rubber compositions and rubber-bitumen binders intended for asphalt concrete pavement of roads and airfields, for sealing expansion joints, for the production of building waterproofing materials, etc.

The technical result is an increase in the physicomechanical characteristics of rubber-bitumen binders and composite materials based on them, an extension of the temperature range of plasticity, an increase in frost resistance, resistance to cyclic deformations at low temperatures, and an improvement in the vibration-absorbing properties of asphalt concrete.

This result is achieved by the fact that in the method for producing a bitumen modifier, comprising mixing crumb rubber with a polymer material, according to the invention, rubber powder of a fraction of 100-300 μm is used as rubber crumb, polyvinyl ether with a molecular weight of 250000-400000 units is used as a polymer material. and additionally, alkyl betaine and / or cocamidopropyl betaine (C8-C22) and alkylbenzyldimethylammonium chloride (C8-C22) in the following ratio, wt.%:

- 1 016187 rubber powder fractions 100-300 μm 85.0 -95.0 polyvinyl ether with a molecular weight

250,000 - 400,000 units 4.45 -12.4 alkyl betaine and / or cocamidopropyl betaine (Cia-C ^) 0.05 -1.5 alkylbenzyldimethylammonium chloride (Ca-C ??) 0.01-1.1

The bitumen modifier is a composite material that includes rubber crumb with a developed surface and a bulk density of less than 400 kg-m ³ (particle size 100-300 μm), obtained by grinding old tires and waste rubber products. The stabilizer alkyl betaine and / or cocamidopropyl betaine (C ₈ -C ₂₂ ) is designed for fast and uniform distribution of rubber powder in the mass of bitumen. The water-repellent alkylbenzyldimethylammonium chloride (C ₈ -C ₂₂ ) is designed to inhibit bacterial corrosion, biofouling and oxidative degradation. The low-temperature adhesive additive polyvinyl ether (molecular weight 250000400000 units) is intended to increase the adhesive properties of rubber-bitumen binders to various mineral materials and preserve plastic properties at low temperatures (up to -45 ° C), helps to regulate the process of destruction and crosslinking of rubber particles in bitumen without noticeable segregation due to the formation of chemically active centers.

The method is as follows.

Example 1. Rubber powder is mixed with a hydrophobizing agent in the form of alkylbenzyldimethylammonium chloride (C ₈ -C ₂₂ , a stabilizer in the form of alkyl betaine and / or cocamidopropyl betaine (C ₈ -C ₂₂ ) and a low-temperature additive in the form of polyvinyl ether in an activator type mixer at a temperature of 50 ° C by the method of dry mixing The finished modifier is Packed in a sealed container and sent to the site of preparation of rubber-bitumen binders.

The components are taken in the following ratio, wt.%: Rubber powder fraction 100-300 μm 85.0 alkyl betaine and / or cocamidopropyl betaine (C8-C22) 1,5 alkylbenzyldimethylammonium chloride (C8-C22) 1,1 polyvinyl ether (molecular weight 250000-400000 units) 12.4

Example 2. The method is carried out as in example 1, but the components are taken in the following ratio, wt. %:

rubber powder fractions 100-300 μm 95.0 alkyl betaine and / or cocamidopropyl betaine (C ₈ -C ₂₂ ) 0.05 alkyl benzyl dimethyl ammonium chloride (C ₈ -C ₂₂ ) 0.5 polyvinyl ether (molecular weight 250000-400000 units) 4.45

To obtain modified bitumen based on the above modifier, heated bitumen (BND 40/60, BND 60/90, BND 90/130, BN 60/90 grades according to GOST 22245-90) is mixed with a modifier at a temperature of 170-185 ° С. Mixing is carried out in a perfect mixing apparatus with forced circulation through a gear pump. The dosage of the modifier is carried out in several steps, in order to avoid a sharp increase in the viscosity of the mixture, the amount of modifier introduced depends on the conditions for the use of modified bitumen and ranges from 5-15 wt.%. The process of bitumen modification takes place within 0.25-0.5 hours.

Rubber-bitumen binder, obtained on the basis of the declared modifier, has the following physical and mechanical characteristics:

the softening temperature of the ring and ball 53 ° C (the prototype 50 ° C);

the fragility temperature of -27.1 ° C (the prototype is -17 ° C); needle penetration depth 0.1 mm at a temperature of 25 ° C 64 mm, at a temperature of 0 ° C 26 mm; extensibility at a temperature of 25 ° C 12 cm, at 0 ° C 8.2 cm;

elasticity at 0 ° C 35;

flash point 280 ° C;

softening temperature change after warming up 4 ° С.

The use of rubber-bitumen binders based on the proposed modifier in the composition of crushed stone-mastic asphalt concrete allows to reduce water saturation by 10%; increase the compressive strength at 50 ° C by 1.4 times; increase the tensile strength at a split by 7%; increase shear adhesion of samples by 30%. Due to the porous structure of the modifier, the noise absorption of asphalt concrete increases to 15%.

- 2 016187

The advantage of the proposed method is as follows:

a bitumen modifier is prepared on a stationary installation by cold mixing, which eliminates the work at high temperatures and reduces energy consumption;

the finished modifier is packaged in quota containers, which allows it to be used for modifying bitumen in conditions of asphalt plants without additional costs;

a bitumen-rubber composition based on a modifier has high strength characteristics both at low and at high temperatures;

bitumen modification process takes 0.5 hours in perfect mixers; this is achieved by introducing alkyl betaine and / or cocamidopropyl betaine (C ₈ -C ₂₂ ), alkylbenzyl dimethylammonium chloride (C ₈ -C ₂₂ ) and polyvinyl ether (molecular weight 250000- 400,000 units)

Claims (1)

A method of producing a bitumen modifier, comprising mixing rubber crumb with a polymer material, characterized in that rubber powder of a fraction of 100-300 μm is used as rubber crumb, polyvinyl ether with a molecular weight of 250000-400000 units is used as a polymer material. and additionally, alkyl betaine and / or cocamidopropyl betaine (C ₈ -C ₂₂ ) and alkylbenzyldimethylammonium chloride (C ₈ -C ₂₂ ) in the following ratio of components, wt.%: rubber powder fraction 100-300 μm 85.0 -95.0 polyvinyl ether with molecular weight 250 000 - 400 000 units 4.45 - 12.4 alkyl betaine and / or cocamidopropyl betaine (Cia-C?> ₂ ) 0.05 - 1.5 alkylbenzyl dimethylammonium chloride (Ck-Crg) 0.01-1.1 Eurasian Patent Organization, EAPO Russia, 109012, Moscow, Maly Cherkassky per., 2