DD289054A5 - METHOD FOR PRODUCING POLYMODIED BITUMENES - Google Patents

Abstract

The invention relates to a process for the preparation of polymer-modified bitumen as a basic component for Straszenbau- or Bautenschutzzwecke or prefabricated sealing materials for building and corrosion protection. According to the invention, the polymer-modified bitumen is prepared from 67 to 98 parts by weight of bitumen, 1.8 to 30 parts by weight of polybutadienes and 0.2 to 3.0 parts by weight of sulfur and stirred at a temperature of 160 to 230 ° C for up to 12 hours {polymer-modified bitumen; polybutadienes; Sulfur; Bitumen}

Description

Field of application of the invention

The invention relates to a process for the preparation of polymer-modified bitumen bitumen, polybutadiene and sulfur bitumen for use as a basic component for road construction or building protection purposes or prefabricated sealing materials for buildings and corrosion protection.

Characteristic of the known state of the art

Bitumen and bituminous mixtures are used in large quantities as binders for the production of road surfaces or building protection materials. The properties of the bituminous materials are not sufficient for a large number of applications, especially for heavily loaded roads, heavily used roof coverings or hydroinsulation. For this purpose, high polymers in the form of elastomers or plastics are added to a greater extent. Particularly good properties are achieved by the addition of thermoplastic rubbers or atactic polypropylene. While the former component, in particular, greatly improves the bitumen properties at temperatures below freezing, the improvement of the thermal behavior is particularly attained by adding the latter plastics. Improvements would always be achieved if the polymer component is soluble in the bitumen, or if it forms net-like structures in the bitumen. This is achieved by thermoplastic rubbers which, in additions of 4 to 15%, give the bitumen mixture elastic properties in a certain temperature range. The ability particularly good block polymers of butadiene and styrene or isoprene and styrene are preferred with molecular weights of 30,000 to 500,000. These substances can be mixed quite easily as granules or as a powder at temperatures above 180 ° C into the bitumen homogeneous. The cooled mixtures then reach a net-like structure which gives the entire fabric rubber-like properties with high elongation and high resilience.

Thus, such blends are eminently suitable for high traffic and wear road construction, but also for highly stressed roof coating materials.

The preparation of the mixtures mentioned is coupled to the availability of the block polymers. The cost of producing such products is very high.

Although the compounding of bitumen with unvulcanized solid rubbers based on copolymers of butadiene or other dienes with styrene or acrylonitrile is possible in principle, the mixing processes require the use of high energies and long mixing times.

Furthermore, the desired elastic properties can not be achieved as with thermoplastic rubbers.

Thus, this application remains limited to a small area for the production of specialty products.

There has also been no lack of attempts to compound already vulcanized rubbers with bitumen.

However, only coarsely dispersed materials with low performance properties are achieved.

Mixing with the production of finely dispersed rubber particles in the bitumen is only possible by devulcanization or destructive methods, which are generally very difficult to control in practice.

The addition of elemental sulfur to the bitumen is widespread. The additions amount up to 30% to the bitumen. Improvements in bitumen grades for heat-resistant road surfaces as well as easements of processability due to viscosity reductions are achieved in particular.

The binder produced in this way! and the asphalts obtained therefrom, however, in no case achieve rubber-elastic properties.

It is also known to carry out the crosslinking process of rubbers in bitumen. In this case, especially butadiene-styrene rubbers are dissolved in the bitumen and reacted with sulfur, zinc oxide or other basic substances and with vulcanization accelerators such as thiurams, thiazoles or other known compounds. The reaction is difficult to control because the reaction products obtained are not or only with great effort processable according to the known in the bituminous field installation methods. The crosslinking process is final, so that no fusible product can be obtained even at high temperatures. This possibility is therefore limited to special application areas only. The incorporation of low molecular weight liquid rubbers leads according to the previously known state only to softening of the bitumen. A vulcanization of these substances is known to lead only to inferior Gurnmitypen without utility value.

The vulcanization must be carried out with relatively large amounts of Vrlkanisationsmitteln sulfur, zinc oxide or other basic substances and ultra-accelerators. Vulcanization with sulfur alone is not possible.

Object of the invention

It is the object of the invention to find polymer-modified bitumens with improved performance properties, with simple and inexpensive production processes with the advantage of readily available and easily processable raw material components. The performance characteristics of the final products to be achieved should be such that the widest possible range of application in the sectors of road construction, building protection and prefabricated sealing materials is achieved. In addition to the bitumen-specific, especially the rubber-elastic behavior over a wide temperature range, such as high resilience and high elongation can be achieved.

Explanation of the essence of the invention The invention is based on the object of providing a process for the production of polymer-modified bitumen from bitumen, Polydienes and sulfur develop. According to the invention, the object is achieved by a process for the preparation of a polymer-modified BiUimens from 67 to

98 parts by weight of bitumen with softening points from 35 ⁰ C to 90 ° C and contents of resins of not less than 25 parts by mass in%, from 1,8 to 20 parts by mass of a polybutadiene having numerical molar masses from 2,000 to 10C00, iodine value of 350 to 450gJ / 100g and

Viscosities be! 20 ° C of up to 250 Pa · s and 0.2 to 3 parts by mass Schv / sfel dissolved, the components at 160 to 230 ° C up to

Stirred for 12 hours.

According to a further feature of the invention, up to 75 parts by weight in% of the bitumen content can be rich in resin in the process Hydrocarbon mixtures, such as heavy vacuum distillates and / or residues of petroleum processing and / or Stone or brown coal processing pitches or tars to be single or in mixture. In the process according to the invention up to 50 parts by mass in% of Polybutadienanteils high molecular weight synthetic rubbers

with numerical molar masses of over 20000.

The process according to the invention makes it possible to achieve polymer-modified bitumen having very variable properties. The desired characteristics can be determined by the quantitative composition, the reaction temperature and by the Reaction time to be controlled. As bitumen, commercial distillation, oxidation or extraction bitumen with softening points of 35 to

Used 90 ⁰ C and resin contents of at least 25 parts by mass in%. The resin content is determined by eluting the malt phase of the

Bitumen after separation of the oils in an activated alumina-filled column with a solvent mixture

determined in equal parts acetone and benzene. It was found that the faster the reaction, the faster the reaction

Resin content in the bitumen is. For example, an extraction bitumen from the propane deasphalting reacts with a Resin content of 55Ma.-parts in% even with little addition of sulfur within 30 minutes, the reaction using Increase of the softening point by about 20 ⁰ C and the reversion from 10 to 75% can be clearly read. As polybutadiene component are polybutadienes having molecular weights of 2000 to 10,000, iodine numbers of 350 to 450g J / 100g

and viscosities at 20 ⁰ C from 1 to 250Pa s used.

These polybutadiene körinen be prepared both by anionic and by stereospecific polymerization. When

The polybutadiene produced in the GDR by anionic bulk polymerization proved to be particularly suitable with the

Trade name Sconamoll 32. For the intended purpose these polybutadienes may have a microstructure

which is characterized by an average (50 parts by mass in%) to high (SOMa.-Tei.'e in%) 1,4-part.

As in the crosslinking of rubbers to achieve the gel point, d. h., the beginning of the three-dimensional Molecular levitation, the molecules must be connected to each other at least once, this is liquid Rubbers with their short-chain molecules Sulfur amounts of more than 5 Ma. Parts in% compared to about 2 Ma. Parts in%

required for high molecular weight rubbers.

As is known, the crosslinking of the liquid rubbers with sulfur alone does not occur, but rather the presence of Vulcanization activators such as zinc oxide and vulcanization accelerators, especially ultra-accelerators,

required. Such crosslinked products have poor physicochemical properties.

It is also possible to use up to 50 parts by mass in% of the polybutadienes by means of high molecular weight synthetic rubbers having molecular weights of

over 20,000 to replace. Appropriately, while the high molecular weight synthetic rubbers with the liquid

Polybutadiene premixed to soft plastic and easily processable combinations. The properties of the end products to be achieved can be further broadened if a part of the bitumen by

Resin rich hydrocarbon mixtures of petroleum processing or pitches or tars of brown or hard coal processing are replaced. The degree of exchange can be up to 75Ma ₁ -TeHe in% of bitumen content.

Surprisingly, it has been found that low molecular weight polybutadienes in the mixture according to the invention with bitumen

and sulfur can be crosslinked at temperatures of 16O ⁰ C to 230 'C without the addition of vulcanization and / or accelerators. The resulting reaction products achieve such properties that an application as

Binder for road surfaces, as a base for building preservatives and as cover for prefabricated waterproofing membranes

allow with increased use values.

In addition to improving the elastic behavior of the new bituminous substances, it has proven particularly advantageous Achieving rubber-elastic properties such as high recovery after stretching and a significant increase in the Elasticity in the usual for polymer modified bitumen Kugelziehmethode. For example, of a reaction product of 90Ma.-Tbi! R> bitumen having a softening point of 40 ° C, a Recovery after 100% elongation of 1%, 10 parts by weight of polybutadiene with a molecular weight of 8500 and 0.75 Ma. Parts Sulfur after a reaction time of 4 hours at 200 ° C, an increase in the softening point of 14K and the Rebound to 80%. In the prior art, the simple mixture of this same bitumen and the same polybutadiene in this In contrast, the composition has no elastic properties and no improvements in the plasticity range. By replacing the bitumen up to 75 parts by mass in% by resin-rich high molecular weight hydrocarbons of Petroleum processing, such as heavy vacuum distillates or residues or pitches or tars or tars

Lignite processing is a further improvement in the cold resistance of polymer-modified bitumen in a desired and graded manner possible. Replacement of the proportion of polybutadiene to SOMa. Parts in% further increases the elastic properties such as elongation and recovery.

By varying the composition of the reaction mixture, the reaction temperature and the reaction time, polymer-modified bitumen having softening points of up to 100 ⁰ C, plasticity margins may be up to 120K and return deformations up to 95%. Since the reaction products have good tackiness, a wide range of applications is possible.

Ausfuhrungsbelspiele

1. In a heated agitator are 900kg bitumen with a softening point of 4O ⁰ C and a content of 40Ma.-parts in% of resins, with the aid of a mixture of equal parts of benzene and acetone in an activated alumina-filled column of the Maltenphase were eluted, warmed to 13O ⁰ C. With stirring, 100 kg of a heated to 130 ⁰ C polybutadiene having a numerical molecular weight of 8500, an iodine value of 380g J / 100g and a viscosity of 180Pa and 7.5kg molten sulfur blended. The entire mixture is heated to 200 ⁰ C and kept at this temperature for 4 hours under constant stirring.

Thereafter, the reaction product formed in this case has, compared with the starting bitumen or the mixture of bitumen Polybutadiene has the following properties:

⁰ C output mixture Fiction ⁰ C bitumen Bitumen/ contemporary Vw mm polybutadiene product Softening point R u. K cm 40 39 54 Breakpoint after Fraaß -16 -17 -16 Penetration at 25 ° C % 180 185 95 Duktilitätbei25 ° C > 100 > 100 > 100 Reversion to % Elongation by 100% 1 2 80 elastic part in the Kugelziehmethode (Jl 8th 64

The reaction product is used for road construction or as a raw material for the production of building protection materials. The rebound is measured at 25 ° C after 100% elongation in the ductility test.

The elastic portion is obtained from the force-elongation diagram of Kugelziehmethode at 25 ⁰ C by planarization (see Esser bitumen, Teere, Asphalte, Peche, Heidelberg 17 [1966] 9,319-328)

2. The following raw materials are used, which are characterized as follows:

bitumen Softening point Ru.K ⁰ C numerical molecular weight Resin content Ma. Parts Pour point ⁰ C Ductility at 25 ⁰ C cm Resin content Ma. Parts Rückvorformurig after 100% elongation at 25 ⁰ C. Viscosity at 70 ⁰ C mPa -s A B C D 37 55 70 88 2050 440 1.2 30 51 48 40 20 15 18 > 100 12 10 2 31 30 33 28 1 0 2 0 202 85 180 polybutadiene Softening point P. u. K ⁰ C Iodine number gJ / 100g Viscosity at 20 ⁰ C Pa s I Il III 42 8000 390 200 9800 355 248 Hydrocarbon mixtures 1 2 3 4

Component 1 is a heavy vacuum distillate of petroleum distillation

 Component 2 is a refinery resin of the propane refinery of petroleum distillates

 Component 3 is a coal tar pitchfish pitch

 Component 4 is a brown coal high temperature tar.

High molecular weight styrenic numerical Synthetic rubbers% molecular weight

ä 27 50000 b. 24 95000 c - 60000

Component a is a SB hot rubber Component b is a SB cold rubber Component c is cis-1,4-polybutadiene with a cis content of more than 90 Ma. Parts in% From these raw materials under the specified process conditions reaction products with the following

given properties.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

feedstocks In Ma. Parts

Bitumen A 60 90 95 95 95 90 - - - 97 - - - 63 63 -

C ------- 67 - - 90 63 63 - - 22 44 66

Polybutadiene I Il III 20 10 I cn I I Ol I Ol I CO I 15 30 20 1.8 10 12 12 12 12 I cn ι I Ol I Ol Hydrocarbon 1 2 3 4 20 - - - - - - - 20 - - 21 21 21 21 66 44 22 Synthetic rubber a b C - - 6 I Ol sulfur - 2 _ Mixing time h reaction temperature ⁰ C - - 0.5 1 - 1 - - - - - - 0.9 1 2 1 180 - 1 0.8 0.8 0.8 2.6 1 1 180 δ 180 1 180 5 4 195 2,180 5 170 3 160 Ο, δ 0.2 1 3 0.8 1.2 0.9 1 4,200 1 2 170 4 170 Ο, δ 200 12 225 1 200 8,230 4,200 3 195 1 180

Properties of the reaction products Softening Point R u. K ³ C 71 55 50 52 64 60 62 90 95 65 90 85 62 80 65 70 75 82 crushing point -22 -16 -15 -18 -22 -17 -10 -7 -25 -12 -8 -15 -14 -7 -10 -20 -25 -26 Penetration Vw mm 155 120 177 159 122 170 57 36 55 120 36 66 105 80 113 125 85 101 Ductility25 ° Ccm 80 100 100 100 100 100 100 40 - 80 40 40 100 52 50 71 55 41 Reverse deformation% 92 76 65 71 81 85 85 88 89 65 89 85 80 80 81 92 90 91 elastic proportion% 85 86 55 60 85 75 63 55 92 70 85 80 92 82 80 90 91 90

Claims (3)

1. A process for the preparation of polymer-modified bitumen from bitumen, Polybutaoienen and sulfur, characterized in that 67 to 98 parts by weight of bitumen having softening points of 35 ⁰ C to 9O ⁰ C and contents of resins of at least 25 parts by mass in% with 1.8 to 30 parts by mass of polybutadienes having numerical molecular weights of 2000 to 10,000, iodine numbers of 350 to 450 g J / 100 g and viscosities at 2O ⁰ C of Ibis 250 Pa · s and 0.2 to 3.0 Ma. - Parts of sulfur at 160 to 23O ⁰ C are stirred for 12 hours. 2. The method according to claim 1, characterized in that up to 75 parts by mass in% of the proportion of bitumen resinous hydrocarbon mixtures, such as heavy vacuum distillates and / or residues of e-dö! Processing and or or pitches or tars of stone or Lignite processing individually or in mixture. 3. The method according to claim 1 and 2, characterized in that up to 50Ma.-parts in% of the polybutadiene are high molecular weight synthetic rubbers with numerical molecular weights of over 20,000.