DE1719183C3 - Sealing and potting compounds - Google Patents

Description

The present invention relates to sealing and potting compounds, which are composed of certain block copolymers, Bitumen and aromatic petroleum oils, preferably those that are used to Grouting or potting the points of contact of concrete pavements, e.g. B. suitable on motorways. she correspond in a particularly advantageous manner to the requirements with regard to binding, flowability and Penetration depth as required for high-quality, hot-cast sealing and potting compounds will.

From US-PS 30 41 299 combinations of bitumen with synthetic rubber compounds are already in Form of polymers of butadiene or chloroprene and butadiene-styrene copolymers for the production of road surfaces or known as protective coatings In F-PS 77 705 (addition to F-PS 12 58 864) are mixtures of coal tar with thermoplastic polyvinyl chloride as a binding and sealing agent known These products become brittle at lower temperatures and lose their properties as a result Elasticity and resistance to vibrations and shock loads.

It has now been found that sealing and potting compounds, in particular for sealing the Joints in concrete pavement are intended to serve, and bitumen, synthetic rubber and bitumen solvents contain, have improved adhesion and strength properties if they contain the in claim 1 have said composition.

The block copolymers used in the present sealing compounds according to the invention are so-called self-vulcanizing rubbers; i.e. they have the properties of a vulcanized rubber, without actually being vulcanized. In these block copolymers, the block polymers A are im essentially thermoplastic, while the central block B is essentially an elastomeric one Is block polymer. In addition, hydrogenated block polymers can also be used. Preferred however, the non-hydrogenated block copolymers are used as components of the sealing compounds according to the invention. If hydrogenation occurs, this can be done to any extent. However, it is desirable that at least the diene polymer blocks are hydrogenated to reduce their carbon-carbon unsaturation to reduce at least 50%. In particular, there will be at least 90% of the total unsaturation of the block copolymer hydrogenated

The thermoplastic terminal blocks A have molecular weights between 7,500 and 100,000, in particular between 10,000 and 50,000. The molecular weight of the elastomeric middle block B is between 25,000 and 1,000,000, preferably between 35,000 and 150,000. The proportion of. thermoplastic end blocks is expediently 10 to 70 wt .-%, preferably 20 to 50 wt .-%, based on the weight of the entire block copolymers.

The vinyl-substituted one most suitable for making the block copolymers in question aromatic hydrocarbon is styrene; However, ring-substituted styrenes can also be used Application. The most common conjugated dienes are those with 4 to 8 carbon atoms Molecule in question, especially isoprene and butadiene. The one used to manufacture either the thermoplastic End blocks or the elastomeric middle blocks 1-Alkenes are 1-alkenes with 2 to 12 carbon atoms in the molecule, e.g. ethylene, propylene, butene-1, hexene-1 and octene-1.

Suitable examples of the block copolymers to be used according to the invention are polystyrene-polyisoprene-polystyrene, Polystyrene-Polybutadiene-Polystyrene, Polyethylene (Ethylene-Propylene Copolymer) -Poly-

ethylene, polypropylene- (ethylene-propylene copolymer) -polypropylene and the corresponding hydrogenated derivatives, in particular the block copolymers, the Contain diene homopolymer blocks. The block copolymer polystyrene-polybutadiene-polystyrene is particularly preferred, in which each polystyrene block has a molecular weight between 10,000 and 15,000 and that The polybutadiene block has a molecular weight between 35,000 and 150,000, the polystyrene block 20 to 50% by weight based on the weight of the total block copolymer

The bitumens used with preference are non-oxidized, simple, i.e. H. without conversion, distilled Bitumen with a viscosity between 65 and 175 SSF at 135 ° C and a ring and ball softening point between 30 and 60 ° C Three typical bitumens that meet these requirements have the following physical properties:

Table I.

Viscosity at 135 ° C, SSF
Ring and ball, softening point, ° C

65 157 69 32 55 48 The selection of certain aromatic petroleum oils had proven necessary in order to give the sealing and potting compounds the desired physical properties and adequate compatibility. For this latter purpose, highly aromatic petroleum oils have proven to be extremely suitable, since the block copolymers used according to the invention are compatible with aromatic hydrocarbons, but the non-oxidized bitumen described above have too low a content of aromatic components and therefore do not produce the desired degree of compatibility. It was furthermore desirable to select those oils whose inherent viscosity properties were appropriate not only for use by hot potting but also for use in normal weather conditions. Preferred oils have a viscosity between 90 and 275, in particular between 100 and 150 SSU at 99 ° C. and a content of aromatic constituents below 95%, preferably between 69 and 75% by weight, measured by clay-gel analysis. In general, the flash point of these oils is at least 200 ^° C., preferably at least 220 ^° C. The following table summarizes the physical characteristics of some generally suitable and preferred commercially available oils.

Table II I. oil B. C. D. E. F. G I. A. 2870 4280 15 800 6070 11340 9206 «!
ί Viscosity, SSU / 37.8 ° C 3235 85 91 107 124 148 145 ί SSU / 99-C 83 0.9806 0.9868 1.0351 0.9951 03965 1,0007 g spec. Density / 15.5 ° C 0.9895 227 222 322 224 227 227 I flash point, "C 219 18.5 -4 10 10 24 10 (j pour point, ⁰ C 16 !: Distillation, "C 428 393 393 421 387 390 Start of boiling 356 420 400 407 427 412 394 J 5% by weight 395 424 413 411 434 422 407 I 10% by weight 406 434 443 437 453 452 453 I 50% by weight 434 449 482 473 497 515 553 I 90% by weight 461 41 45 -10 28 39 32 ί aniline point, "C 41 49 49 28 42 47 43 Mixed aniline point, ° C 44 0.951 0.938 0.999 0.943 0.943 0.948 j Viscosity-density, constant 0.944 1.5563 1.5552 1.5980 1.5736 1.5665 1.5722 Refractive index / 20 ^o C 1.5620 I molecular analysis, clay gel, I % by weight 0 0 0 0 0 0 I asphaltenes
I polar connections 0 11.4 18.2 23.0 16.0 13.5 19.4 I Aromatic KW 10.0 67.8 52.8 70.3 72.5 71.0 68.1 t Saturated KW 69.88 20.8 29.0 6.7 11.5 153 12.5 20.2

The three components of the sealing compounds according to the invention can be combined with one another in varying amounts within the limits specified above depending on the intended use. Since the preparations described herein are in are mainly intended as hot-cast sealants, which in particular each of the three im The following example should satisfy the test procedure described below, the relative weight ratios depend depends on the specific identity of each of the components or on its combination with others. Particularly suitable weight ratios, which depend on the identity of the bitumen, are as follows Table III listed.

Table St.

R and K softening point, ° C

Wt%

bitumen
Viscosity at
135 ⁰ C SSF

60-63

68-175

Block copolymer
oil

30-40
40-65

20-50

15-30
35-50

35-65 15-30 20-35

With the masses listed in the table, optimum properties are achieved if they Bitumen with a polystyrene-polybutadiene-polystyrene block copolymer can be combined in which each polystyrene block has a molecular weight between 12,000 and 20,000 and the polybutadiene block has a molecular weight between 10,000 and 70,000, and with an oil which is between 70 and 75% by weight aromatic Contains ingredients and a viscosity between 115 and 130 SSU at 99 ° C

example

The three constituents were mixed with one another in a double-arm kneader (Pfleiderer kneader) in the proportions given in Table IV. The oil was the ö'E characterized above, the bitumen was the bitumen A, B and C given in Table I and the block copolymer was a polystyrene -polybutadiene-polystyrene block copolymer with molecular weights from 000 to 52 000 to 17 000 applied from 14 the resulting materials were spilled hot at a temperature of 207 ⁰ C test samples. These samples were tested with regard to adhesion, pourability and penetration

■ 5 fe tested

To test the bond, the samples were each 25.4 mm between two χ 50.8 mm χ 76.2 mm large concrete blocks set at a distance of 25.4 mm are poured. The samples were

ι ο stretched 12.7 mm at a rate of 3.175 mm / h and at a temperature of -18 ° C. If a crack, separation or other opening that was 635 mm deep at any point in the sample or i wipe the sample and the concrete block occurred

ι s the sample fails in this test The sealant passed the test successfully if none of three Samples failed in five elongation cycles.

To test for flowability, samples 40.64 mm wide, 6036 mm long and 3.048 mm thick were cast on a tin-plated metal sheet. The plate was placed thereon in an angle of 75 ° and held for 5 h at 60 ⁰ C. The maximum allowable flow was 5.004 mm.

The test for the depth of penetration was

performed according to ASTM 5-99, with the exception that a fat cone was used instead of the normal needle. The total weight of the cone and the Accessories was 150 g. The maximum permissible penetration was 9.129 mm.

3d In Table IV are a number of sealants who successfully passed each of these three tests.

Table IV Weight percent 36 34 20th - - - - - - - - - - - _ - 65 60 52 45 40 35 - - - _ bitumen 38 - - _ - - - - - - 60 50 45 40 A. - 24 26th 30th 15th 15th 20th 25th 25th 30th 20th 25th 30th 30th B. _ 40 40 50 20th 25th 28 30th 35 35 20th 25th 25th 30th C. 22nd Block copolymer 40 oil

A number of limits lying outside the limits specified according to the invention were used for comparison Sealants made. The proportions in these sealants, either in the adhesive test or failed the fluidity test, or both tests, are set out in Table V. the Butmen, block copolymers and oils used were identical to those in Table IV.

Claims (5)

Patent claims: 1. Sealing and potting compounds, in particular for sealing the imperfections in concrete roads ^r > cover, consisting of bitumen, synthetic rubber and bitumen solvent, characterized in that they are made of a) 10 to 75 wt .-% of a non-oxidized bitumen with a viscosity between 50 and ι ο 225 SSF at 135 ° C and a ring and ball softening point between 25 and 70 ⁰ C; b) 10 to 35% by weight of an optionally hydrogenated one Block copolymers of the general formula A-B-A, in which A is selected independently Polymer blocks of a vinyl-substituted aromatic hydrocarbon or a 1-alkene with an average molecular weight between 7,500 and 100,000 and B. Polymer block of a conjugated diene or several 1-alkenes with an average molecular weight are between 25,000 and 1,000,000; and c) 15 to 55% by weight of a petroleum oil with a 2> Minimum content of aromatic components of 50% by weight according to the clay-gel analysis and a viscosity between 80 and 300 SSU at 99 ° C exist. 1" 2. Sealing and potting compounds according to claim 1, characterized in that the block copolymer a polystyrene-polybutadiene-polystyrene block copolymer where each polystyrene block has a molecular weight between 10,000 and 50,000 and r> the polybutadiene block has a molecular weight between 35,000 and 150,000 and wherein the Polystyrene blocks make up 20 to 50% by weight of the total weight of the block copolymer. 3. Sealing and potting compounds according to claim <* i> 2, characterized in that each block of polystyrene has a molecular weight between 12,000 and 20,000; and the polybutadiene block has a molecular weight between 40,000 and 70,000. 4. Sealing and potting compounds according to claim -r> 1-3, characterized in that the petroleum oil has an aromatic content between 69 and 75 wt% and a viscosity between 100 and 150 SSU. 5. Sealing and potting compounds according to claim w 1-4, characterized in that as components a) and c) 35 to 65 wt .-% asphalt with a Viscosity between 68 and 175 SSF at 135 ° C and a ring and ball softening point above 40 ° C, and contain up to 35% by weight petroleum oil. v>