DE2503716C2 - Process for the production of bituminous masses - Google Patents

Description

The invention relates to a method for the production of bituminous masses from bitumen and a chlorinated polyolefin.

As is known, flexible thermoplastic compositions which are suitable as coating compositions and membranes can are made from bitumen and chlorinated polymers. For example, GB-PS 10 58 451 describes a bituminous mass made up of blown or oxidized bitumen from petroleum and a bitumen containing chlorine Polymer consists. The GB-PS 12 50 756 describes a thermoplastic mass, the bitumen or pitch of mineral origin and a chlorinated polyethylene resin. Mixtures of bitumen with a chlorinated one Polyolefin have also been suggested for use as asphalt paving and road construction materials. The US-PS 30 50 483 describes an asphalt in which 0.5 to 5.0 parts by weight of a normally solid Polyethylene which is 15 to 35% by weight chlorinated, are dispersed. The US-PS 33 16 649 describes a ||

Asphalt paving compound which contains 1 to 5% by weight of a solid linear Polymeri- ™ containing 15 to 28% by weight of chlorine

Contains sats of ethylene.

One of the problems with blending bitumen with chlorinated polyolefins is the difficulty in getting too ensure that the mixtures remain homogeneous. This problem becomes greater as the chlorinated content increases Polyolefin more and more difficult. By simply mixing the ingredients at moderately elevated temperatures, ϊ |

ζ. B. at 110 ° C, mixtures are usually obtained which are inhomogeneous at low temperatures. In order to ensure homogeneity, a certain interaction between the bitumen and the chlorinated polyolefin must be ensured. The invention is based on the object of making bituminous masses of bitumen with more than 5% by weight of chlorinated polyolefin available that are homogeneous. _{; i} j

The solution to this problem is a process for the production of bituminous masses by heating a j |

Mixture of bitumen and, based on 100 parts by weight of bitumen, 6 to 150 parts by weight of a chlorinated -jj

Polyolefin at temperatures in the range from 150 to 200 ° C, optionally in the presence of stabilizers and accelerators, which is characterized in that it is carried out in the presence of a dehydrochlorinating agent.
Any compounds known to remove HCl from chlorinated polyolefins at said temperatures can be used as the dehydrochlorinating agent. Zinc oxide is preferred as the dehydrochlorinating agent.

It is not intended to be bound by theory, but it is believed that heating the Bitumen and chlorinated polyolefin first dehydrochlorination of the polyolefin and then crosslinking is effected between unsaturated groups in the bitumen and in the polyolefin. You might expect through simply dehydrochlorinating the polyolefin and crosslinking only the polyolefin molecules makes the mixture less would be homogeneous, but surprisingly the reverse is found, a sign that the interaction between the bitumen and the polyolefin is favored and reinforced. The greater homogeneity makes itself for example in reduced exudation and leakage of the bitumen from the masses according to the Invention noticeable.

Thus, in the method according to the invention, the duration of the heating can vary depending on the temperature 5 Minutes to 1 hour, with shorter heating times in general at higher temperatures required are.

Untreated mixtures of bitumen and chlorinated polyolefin usually have a Shore A hardness of only 30 or less, while the hardness increases to 35 to 80 according to the invention.

Particularly advantageous as bitumen is either the material obtained as a residue from the vacuum distillation of crude oil or the product obtained by blowing such a vacuum residue with air until it has been adequately penetrated. The bitumen used as the starting material preferably has a penetration of 40 to 200 at 25 ° C.
The chlorinated polyolefins used are preferably polyolefins obtained from C2-C4 monoolefins.

For example, polyethylenes of high or low density are suitable, but chlorinated polyethylenes can also be used Polypropylene can be used. The chlorine content of the chlorinated polyolefin can be 15 to 45% by weight.

Products made according to the invention with 6 to 150 parts by weight of chlorinated polyolefin, based on 100 parts by weight Bitumen, produced, form flexible thermoplastic masses that are used as coating masses and membranes are suitable. It is to be regarded as particularly surprising that these are relatively high amounts of chlorinated polyolefin-containing compositions homogeneously obtained by the process according to the invention will. Preferably 50 to 120 parts by weight of chlorinated polyolefin, based on 100 parts by weight of bitumen, used. Mixing and heating is carried out in any suitable container, preferably is constantly stirred.

As already mentioned, the crosslinking of the bituminous masses, which can be recognized by a change in hardness can be achieved by simply heating in the presence of a dehydrochlorinating agent. Through connections, those in the field of rubber and polymer technology as both accelerators and crosslinkers are known, such as, for example, sulfur benzothiazyl disulfide, cadmium diethyldithiocarbamal, ethylene thiourea as well as suitable oil-soluble phenol-formaldehyde resins, the reaction can be accelerated. These Compounds should be added during the later stages or towards the end of the heating.

The masses of bitumen and chlorinated polyolefin become coatings or other products processed, it is expected that they will be reheated to melt, so that the possibility consists that a further dehydrochlorination with resulting further changes in hardness takes place after aem heating of the masses according to the invention, it can therefore be useful to have a Add stabilizer to prevent further dehydrochlorination and crosslinking. Stabilizers of this Art are known in the field of rubber and polymer technology. Lead or lead, for example, are suitable Calcium stearate or phthalates, organotin compounds, epoxy resins and epoxidized soybean oil.

The amount of the dehydrochlorinating agent, the accelerator and any stabilizer used depend on the desired degree of crosslinking, but are expediently 0.5 to 5 parts by weight Dehydrochlorinating agent, 0.5 to 10 parts by weight accelerator and 1 to 10 parts by weight stabilizer each to 100 parts by weight of chlorinated polyolefin.

Depending on the use of the compositions produced according to the invention, these can also contain fillers, such as Limestone powder, ground fuel ash, soot, clay, silicon dioxide or asbestos, can be added.

The invention is further illustrated by the following examples, with the following basic components were used:

Bitumen: Kuwait bitumen with penetration 80/100 at 25 ° C

Chlorinated high-density polyethylene with a chlorine content of 36% by weight and about 400 to 1000 carbon atoms per chain

Dehydrochlorinating agent zinc oxide
Lead stearate stabilizers

commercially available epoxy resin Epon 828
Accelerator p-butylphenol-formaldehyde resin

The ingredients were mixed in a Brabender mixer with a mixing head for rubber compounds, the masses then pressed and into test specimens of suitable size for the determination of the physical properties cut.

Stabilizers used were added towards the end of the mixing process, accelerators after mixing and cooling to 60 ^° C., but before pressing. Samples of the pressed masses were tested for hardness, tensile strength, elongation at break, tear resistance and exudation or strike-through. In the latter test, strips were placed on paper and held at 65 ° C for 16 hours. The discoloration of the paper was visually evaluated (a rating of 10 corresponds to *, a staining or staining of 100%, a rating of 0 being no staining or staining).

The ingredients used, the mixing temperature and mixing time, the molding temperature and time and the test results are given in the following tables, with Examples A, B and C being Comparative examples is.

Tabel IA bitumen Dehydrochlo stabilizer Lead stearate accelerator example Chlorinated Kuwait- ration agent Epon 828 G p-butylphenol Polyethylene bitumen zinc oxide G Formaldehyde resin G 80/100, g G G 35 - A. 35 35 1.0 - - B. 35 35 _ _ - - C. 35 35 0.5 - 1.5 - 1 35 35 0.5 0.6 1.5 - 2 35 35 0.5 0.6 _ 3.6 3 35 35 1.0 _ - 4th 35

Table IB

at Mixed Mixed Formge Shaping Shore train Fracture- Tear Switch off game duration tempe exercise temperature A hardness firm strain firm zen after Min. rature Time ⁰ C speed % speed 16h ⁰ C Min. MN / m- N / mm at 65'C

30 30 60 20 45 45 5

90 140 160 160 160 160 160

150
150
150
150
150
160
150

31
32
30th

34
42
56
50

3.3
3.0

5.0
4.8
7.8
1.8

900
670

1000
740
400
110

11th
10

20th
26th
29

18th

Comparative Example A of Table 1, which was not carried out according to the invention, shows that a relatively soft material with a pronounced tendency to exudate and bleed through is obtained when bitumen and chlorinated polyolefin are mixed at low temperature. In Comparative Examples B and C, the temperature was not yet sufficient to achieve sufficient Shore A hardness, even though zinc oxide was present in B. Examples 1 to 4 were carried out according to the invention. The mixture was mixed at 160 ^° C. in the presence of zinc oxide. A sharp increase in hardness and tear resistance was found. In Example 1, this improvement in hardness and tear resistance was achieved without deterioration in elongation at break, while in Example 4 the amount of zinc oxide at the temperature used was apparently too high, since excessive dehydrochlorination resulted and a weak, porous structure was obtained.

Claims (3)

Claims: | j 1. Process for the production of bituminous masses by heating a mixture of bitumen and, based on 100 parts by weight of bitumen, 6 to 150 parts by weight of a chlorinated polyolefin at temperatures im Range from 150 to 200 "C, optionally in the presence of stabilizers and accelerators, thereby characterized in that it is carried out in the presence of a dehydrochlorinating agent. 2. The method according to claim 1, characterized in that zinc oxide is used as the dehydrochlorinating agent is used. 3. The method according to claim 1 or 2, characterized in that the dehydrochlorinating agent in one ίο Amount of 0.5 to 5 parts by weight, based on 100 parts by weight of chlorinated polyolefin, is used.