DE2554415A1 - STABILIZED BINDER - Google Patents

Description

PATENTANWÄLTE DS MÜNCHHN OO

MAIiIAHIL ₁ FPLATZ 2J-3

DR. O. DITTMANN POSTAL ADDRESS

K. L ·. BCIIIFF _w . ₈ MUNICH 93

dr. A. v. FÖNER? S 5 A Λ 1 5 P.O. Box on oieo

DIPL-JKG. P. STREIIL TELKFON (OSi)) 48 20 54

UH. TJ. SOITÜBEL-HOPF telegr. auromakcpat monks

inc D. EÜBINGHAUS tklbx B-23S05 auro jj

3rd December 1975

SULPIFJR DEVELOPMENT INSTITUTE DA-16 603

OF CAKiO) A (Sudle)

Priority: December 3, 1974, Great Britain, No. 52222/74

Stabilized binder

The invention relates to a stabilized binder for mineral Aggregates for the production of floor and paving mixes and a method for its production. The invention also relates to road pavements and their manufacture and particularly relates to compositions consisting of emulsions of sulfur in bituminous materials and which be used as binders for mineral aggregates in the production of floor or paving mixes.

Materials that contain sulfur emulsified in asphalt were described as binders for flooring compounds in US Pat. No. 2,182,837, but these binders have not been used to a large extent used. Namely, these known binders have poor stability and it is necessary to use them in the production of To use flooring materials without delay, which makes it necessary to prepare the binder in the place where the flooring work is carried out. This in turn requires the use of two mixers, one High shear mixers, such as a colloid mill, to form an emulsion of sulfur in asphalt, and a pan grinder, to form an emulsion of sulfur in asphalt to mix the mineral aggregates and the emulsion.

In view of the difficulties encountered in using

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Asphalt-sulfur mixtures have occurred and up before recently, easy accessibility of asphalt under economic conditions, has been "so far by the industry the use of Asphalt alone as a binding agent for aggregates in road and flooring mixes favored.

On the other hand, the invention is based on the object of an improved To make binders with greater stability than the previously used binders accessible, in which the easily and economically accessible sulfur is present in an emulsion with bituminous material, so that the amount of the more difficult to access bituminous material in a flooring mixture can be reduced can. According to the invention, a method that can be carried out in a simple manner is intended for the preparation of these emulsions.

The invention also provides a method of manufacture a road or flooring mixture accessible, when carried out the requirement of a previous mixing process to form an emulsion of sulfur in bituminous Material is avoided.

The subject of the invention is thus a stabilized binder for mineral aggregates for the production of floor and road paving mixtures, which is an emulsion of sulfur and a bituminous material and an amount stabilizing the emulsion of an organosiloxane polymer in which the bituminous material as the continuous phase and the sulfur as the dispersed Phase.

The invention also relates to a method for producing a stabilized binder for mineral aggregates for the production of floor or road paving mixtures, in which with increased Temperature a bituminous material, molten sulfur and an emulsion stabilizing amount of a liquid organosiloxane polymer are mixed together to form an emulsion which is a continuous emulsion composed of the bituminous material Phase and a dispersed phase consisting of molten sulfur.

600824/0911

The invention "also relates to a method for producing a Floor covering material or road surface material, which is mineral Contains aggregates and the binder preparation according to the invention, in which a bituminous material, Sulfur, a stabilizing amount of an organosiloxane polymer and a predominant part of a mineral aggregate are mixed together at the same time.

The invention also relates to the floor covering material thus obtained and a floor covering made therefrom.

According to one embodiment of the invention, a method for the simple flow blending (plugged flow blending) of the bituminous material and the sulfur immediately before the Mixer hopper is provided if it is desirable to have the modifications of that used to apply the topping To simplify the system to enable the inventive Binders used in the manufacture of flooring materials, and also to increase the capacity of the application device for the flooring to be maintained.

In the emulsions according to the invention, the liquid sulfur forms the discontinuous or dispersed phase in the continuous Phase consisting of liquid bituminous material.

While it is not intended that the invention be limited to any particular theory be, however, it is believed that the stabilizing effect of the organosiloxane polymer on the emulsion of sulfur in bituminous material due to the formation of an insoluble monomolecular layer of the polymer at the liquid interface between sulfur and bituminous material and that this monolayer leads to a substantial reduction in the Deposition rate of liquid sulfur particles during storage leads.

Further stabilization of the bituminous emulsion of sulfur can be due to the formation of a mechanical barrier from the polymer at the interface between sulfur and bituminous material

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material, which prevents the liquid sulfur particles from aggregating.

In addition, the development of sulfur-containing gases from the binder is prevented when the specified polymer is in the mixture is present.

The emulsion binder suitably contains about 40% by weight of sulfur and about 60% by weight of the bituminous material. Preferably the sulfur content should not be less than 20 wt .- ^ of the binder and should be about 50 wt -.% Of the binder does not exceed, in particular it should range from etv a 30 to 40 wt .- ^ are / of the binder. In general, the ratio of sulfur to bituminous material in the emulsion does not exceed a value of 1: 1 and is preferably within the range of 43: 100 to 67: 100.

The floor covering mixture contains ^ advantageously about 85 to 95 wt .- ^ the mineral fillers and 5 to 15 wt .- ^ of the binder; However, it should be borne in mind that the preferred proportions of the components of the flooring mixture in each specific case are determined by the type and grain size gradation of the aggregates.

The organosiloxane polymer is used in an amount effective to stabilize the emulsion of sulfur in bituminous material. This amount should be sufficient to prevent any substantial separation of liquid sulfur from the emulsion if it is kept at a temperature of 125 to 145 ^° C. with gentle stirring.

The amount of organosiloxane polymer advantageously exceeds not a value of 0.1 wt. 56, based on the weight of the bituminous Materials and in general amounts on the order of 0.001% by weight are sufficient to achieve the desired stabilization of the To cause emulsion.

609824/0951

"Bituminous materials suitable for the present invention include Mixtures containing bitumen, in their naturally occurring form and as residue from petroleum distillation. A special one the preferred bituminous material is asphalt.

The asphalts used according to the invention should match the ones used Temperatures to be fluid.

Asphalt for floor or road surfaces has a penetration value from about 40 to 400, the degree of penetration selected for a particular situation being largely determined by the climatic conditions in the area is determined which is to be occupied.

The organosiloxane polymer used in the present invention is a liquid polymer of the general formula

CH ₃

CK ₃ -SiO
CH ₃ ^-

CH-CH "j 3 ₍ 3rd

Si-O-Si-O

R-,

2 y

CH->

! ³

Si-CH I

in which η represents a value from 0 to 1000 and R- and Rp can be the same or different and represent alkyl groups with 1 to 6 carbon atoms, phenyl, benzyl, phenoxy or haloalkyl groups with 1 to 6 carbon atoms, for example a of the groups CH ₅ , CgH, -, or C ₅ E ₅ H ₄ . The preferred polymers are flowable polydimethylsiloxanes of the general formula 3

SiO SiO- (CH ₃ I ₂

Y _n

Si (CH ₃ I ₃

609824/095 1

has in the η has a value of 0 "to 2000, and are particularly well suited those polysiloxanes having a viscosity in the range of about 50 Dis about 40,000 centistokes, preferably from 300 to 12,500 and particularly in the order of 1000 centistokes at 25 ⁰ C

Any aggregates can be used as mineral aggregates, usually in bituminous soil and road paving mixtures uses v / earth, as well as synthetic aggregates. Other surcharges than usual pavement surcharges than less important can also be used.

The binder mixtures according to the invention can be prepared by emulsifying the individual components, the bituminous material in the fluid or liquid state, and the sulfur present in molten form, in a mixer in the preferred amounts described above. The organosiloxane polymer and the bituminous material are advantageously premixed in a suitable manner. In this process, any type of conventional mixer for producing emulsions can be used, for example a colloid mill. However, the emulsion can be prepared in a simple manner so that simpler mixing devices can be used. The preferred mixer is a static mixer made of stainless steel (Kenics trademark), which is a simple straight-line mixer with no moving parts and in which the mixing is carried out by simultaneously dividing the flow and radial mixing. The mixing temperature should be in the range in which sulfur in molten, pumpable form, and should therefore be above the melting point of sulfur, that is, be above about 118-119 ⁰ C. The upper limit of the mixing temperature is about 159 ° C; Above this temperature the viscosity of the sulfur increases rapidly by several orders of magnitude and it can therefore no longer be pumped. The preferred mixing temperature is in the range of 130 to 150 C.

In order to store the emulsion, it is transferred to a thermostatically controlled vessel which is kept at 125 to 145 ^° C., in

809 824 / 09S1

which the emulsion is continuously kept in slight motion, which "for example with the help of slowly rotating propellers can be done with a low pitch or with a circulation pump. The emulsion can under these conditions and is ready for use as a binder for making a flooring material.

According to another embodiment, the individual components of the binder together with the mineral aggregate are introduced directly and simultaneously into a mixer and below are mixed according to the conditions given above for emulsification. This pail is particularly suitable as a mixer good a mixed fever.

About the changes to the existing systems for application It is to keep road surfaces as low as possible and to maintain the normal production capacity of the plant generally desirable to include the molten sulfur stream and the bituminous material and organosiloxane polymer stream contains, to be brought together immediately in front of the dosing vessel of the system. This can be done in the most effective manner when the Emulsion by bringing the streams together and simultaneously passing these streams through a Kenics static mixer suitable size above the charging vessel of the plant will.

The size of the mixing device is mainly determined by the required The flow rate of the mass of sulfur and bituminous material through the mixer is determined and is suitable Typically in the range of about 30.5 to 762 cm / sec (1 to about 25 ft / sec), preferably on the order of about 305 cm / sec.

It was found that the binders according to the invention in comparison, show improved storage properties with the known sulfur-asphalt binders and, moreover, to a reduced extent Emit sulphurous gases. Good binding properties were shown when the topping masses were made according to the "Marshall Mix" method tested according to ASTM D1559. The binders also showed

■ *

• ■. 609824 / 0dS1 "-

good results in the freeze-thaw test and in the immersion co-compression test, which carried out vmrdcn to the adhesive properties of the binder compared with conventional asphalt cement for flooring ascertain.

Aging tests indicate that the invention Sulfur asphalt emulsion mortars have better durability than conventional asphalt mortars. Computer analysis of the finished pavement that with the help of the CHEVSL program indicate that using the inventive sulfur-asphalt-Eimilsion mortar Savings in the asphalt mortar layer thickness are possible and therefore lower material costs are incurred.

Marshall stability tests carried out on fresh sulfur-asphalt mortars according to the invention show similar results Values as for comparable asphalt mortars; however, after curing for a period of 2 weeks, it is observed that the Marshall stability of the sulfur-asphalt-emulsion-mortar increases significantly without a simultaneous disturbing decrease the Marshall fluidity occurs. With conventional asphalt mortars, on the other hand, there is no change in the Marshall stability with the Time observed.

A particularly important aspect of the binders according to the invention is that the sulfur shows "undercooling", i.e. remains liquid below its melting point. To this Way, keep pavement mixtures containing the sulfur-asphalt emulsions as binders, their processability at lower temperatures than corresponding mixtures that contain contain conventional asphalt binders, whereby numerous advantages are achieved, which are known to the person skilled in the art.

The invention is explained in more detail by the following examples, without that it should be restricted to these.

example 1

The components listed below were used in a total

. 609824/095 1 '

amount of 1800 g in a mixer and " ^{emulsified at a temperature of 130 0} C for 10 minutes.

liquid sulfur 37.5 wt .- #

liquid asphalt 62.5 Cew .- #

(GuIf ACSOO trademark)

Polydimethylsiloxane 0.001 wt .- ^ (be ~

(Dow Corning 200 Fluid - moved to the

Trademark) Weight of the

Asphalt)

A. Comparative experiment was carried out without the addition of the polydimethylsiloxane.

The mixer used was a Cowles dissolver, Model IVG, ir. With a Cowles high shear paddle wheel No. B-1530 (7.6 cm diameter) operating at a speed of 4400 rpm. The emulsion formed was degassed to remove the entrained air and separate samples of the emulsion were stored at 13O ⁰ C under gentle agitation (with the aid of a rotating with 100 to 125 rpm propeller). Density measurements were made in the top (T) and bottom (B) of the three samples to determine if separation occurred. The results are shown in Table 1.

Table 1

Sample 1/2 h 5 h 72 h

_T TB T BT .B

Comparison 1.19 1.05 1.05

1.18 1.80 1.80

Polydimethylsiloxane 1.19 1.10 1.15

1.19 1.21 1.20

The matching emulsion had worn out within 5 hours Separation of sulfur separated, as by the strong change

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tion of the density between the top and bottom of each sample is shown, while the inventive material after 72 hours Storage in the heat was essentially unchanged.

Example 2

A stream of molten sulfur and a stream containing asphalt (GuIf Penetration 150-200) and polydimethylsiloxane (Dow Corning ^ 200 Fluid) ($ 0.001 wt. Based on the asphalt) were combined and passed through a static mixer (Kenics, Model 1 / 2-10-320-0). This mixer has varied a diameter of 1.27 "and contains 6 cm helical baffles. The temperatures of the fluid streams were at 138 ⁰ C gehalten.Die linear flow rate through the mixer was 6.1 to 70.1 cm / sec and the Sulfur content varied between 15 and 85% by weight of the asphalt. Samples of the emulsion prepared in this way were examined for particle size distribution using a photomicrographic method. In all cases the average particle size was less than 5 microns and the range of particle size distribution was narrow.

Example 3

Flooring mixes were prepared by simultaneously adding liquid sulfur and asphalt cement containing polydimethylsiloxane (Dow Corning 200 Fluid) to a heated aggregate in a Hobart laboratory mixer. The mixing temperature was 138 ° C and the mixing cycle
mix had the following composition

door was 138 ° C and the mixing cycle was 60 seconds. The GE-

Asphalt cement, penetration 150

up to 200 (Gülf ACSOO trademark) 4.5 parts by weight

Liquid sulfur 3 »0 parts by weight

Polydimethylsiloxane (Dow Corning 0.001 part by weight, based on

200 fluid) S ^eu on the asphalt

Aggregate (well classified, 92.5 parts by weight 9.5 mm).

824/0951

- Ii -

A comparative mixture containing 6.5 parts asphalt and no sulfur and another mixture in which the sulfur and asphalt had been pre-emulsified in a Kenics static mixer were also prepared. The samples were tested using the Marshall method. The comparison asphalt v / urde at 127 ° C together, where 35 beats / surface were applied, while the emulsion surface samples were pressed together at 121 ⁰ C and with 30 strokes /. The results are shown in Table 2 below.

tab

lie

Sample Marshall Stability, kg (lbs) flow-0.254 imn (0.01 ins)

24 hours after molding

14 days after molding

24 hours after 14 days after molding the molding

929, 86
(2050)

voremul- 1220.2

yawed

S.A. (2690)

Comparative ^{929 '86}
sample (2050)

1551.3 (3420)

1927.8 (4250)

929.86 (2050)

9.5

9.0

12.0

12.5

11.0

12.0

S.A. denotes the sulfur-asphalt emulsion according to the invention.

The initial Verpreßtemperatur of 121 ⁰ C, which is applied to the sulfur-asphalt sample, ensuring that the sample temperature drops during compression to below the melting point of sulfur. If solidification of the sulfur occurs during compression, the samples lose their compressibility, which is expressed in a lower density and Marshall stability. The data in Table 2 indicate that no freezing occurred during compression. Although the sulfur-asphalt sample that had not been pre-emulsified had a slightly lower Marshall stability than the pre-emulsified sample,

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the 24 hour value was quite high and the characteristic one Increase in Mars ball stability over the 14 day period was observed.

A paving mix was made using a Roughly working asphalt paving device with a capacity of 907.18 kg (2000 Ib). The mixture was as follows Composition:

Asphalt cement, penetration 150 to 200 (Gulf AC500)

sulfur

Polydimethylsiloxane (Dow Corning 200 Fluid)

Aggregate (well classified, 1.27 cm)

4.53 parts by weight 2.67 parts by weight

0.001 part by weight, based on the asphalt

92.8 parts by weight

The stream from the asphalt containing the organosiloxane polymer, was combined with the stream of molten sulfur and passed through a Kenics model KMOD-IO mixer. It acted was a mixer unit 3.8 cm in diameter that contained 6 helical elements or baffles. The asphalt and the sulfur was maintained at 138 G and the rate of flow through the mixer was 548 cm / sec (18 ft / sec). the Sulfur-asphalt emulsion was dosed into a mixing bowl containing the heated aggregate (149 ° C), and the emulsion and the Aggregates were mixed for 30 seconds. Samples of the mixture were tested using the Marshall method according to ASTM D1559. The results obtained are shown in Table 3 below.

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14 days after
the shaping 1 1 e 3 2 554415 1206.6 Flow-O, - 13 - (2660) 24 h after
the shaping 254 mm (0.01 ins) T a b e 1378.9 8th 14 days after
the shaping Marshall stability, kg (lbs) (3040) 10 24 h after
the shaping 9.5 1147.6 9.5 (2530) 1052.3 (2320) Example 5

A shelf life study was carried out, with the change the stiffness or strength of asphalt mortar, the filler aggregates with normal weight and light filler aggregates and was tested for conventional and sulfur-asphalt emulsion binders.

Before the samples were subjected to the test conditions, the elastic modulus, M _R , and the density of each sample were determined. The samples v / ere for a period of 7 months at two temperatures, namely -17.8 ⁰ C and 60.0 ⁰ C, kept in a dry environment. It has been shown that in the case of conventional asphalt mortar, storage for 7 months at 60 ^° C. corresponds to an aging of 5 to 7 years with regard to the retention of the viscosity of the asphalt. The second temperature of -17.8 ⁰ C was applied to determine the changes of the value M _R at an extremely low temperature for the application of asphalt mortar. The results obtained are shown in Tables 4 and 5 below.

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Tab e 1 1 e 4

, 0,

Sample originally M ", final value of M _R , final value of

kg χ ΙΟ ⁵ (χ ΙΟ ⁵ psi) kg χ ΙΟ ⁵ (χ ΙΟ ⁵ pel) ^M R ' ⁱⁿ * ^des

Initial value

Emul
sion A 0.2714
(3.86) Just ace
phalt A 0.0907
(1.29) Emul
sion B 0.274
(3.90) Just ace
phalt B 0.0794
(1.13)

0.1961 (2.79)

0.0555 (0.79)

0.2453 (3.49)

0.0464 (0.66)

72.3 61.6

58.2

A: Normal weight aggregate

B: light aggregate

Emulsion: binder according to the invention

Table 5

Results_of_storage

Sample originally M _R ,

kg χ 10 ⁵ (x 10 ⁵ psi)

Final value of M _R. Final value of ⁵

kg χ 10 ⁵ (x 10 ⁵ psi) ^M R> ⁱⁿ ^ ⁰

Initial value

Emulsion A

Asphalt A only

Emulsion B

Asphalt B only

0.2614 (3.72)

0.08858 (1.26)

0.2770 (3.94)

0.0654 (0.93)

0.2946 (4.19)

0.3276 (4.66)

0.3986 (5.67)

0.2151 (3.06)

112.7 370.7 143.9 328.5

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- 1ί

Table 4 shows that at -17.8 ⁰ C a decrease of the M _R - ¥ erts of all samples is achieved.

The samples according to the invention made from Schviefel asphalt emulsion mortar however, show a greater retention of strength than conventional asphaltic mortars.

From Table 5 it appears that when stored at 60.0 ⁰ C, the samples from sulfur-asphalt emulsion mortar proportional suffer a much smaller increase in strength than conventional asphalt mortar samples.

This shows less aging (hardening) of the sulfur-asphalt-emulsion-mortar and speaks for better durability properties than the corresponding conventional asphalts.

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Claims (16)

Pa t e η t a n s_p r ü e h e ~ L · / Stabilized binder for mineral fillers in the production of flooring or road paving mixtures, containing an emulsion of sulfur and a bituminous material and an emulsion stabilizing amount of an organosiloxane polymer, the bituminous material being the continuous phase and the Sulfur forms the dispersed phase of the emulsion. 2. Binder according to claim 1, characterized in that that it is an organosiloxane polymer of the formula CH, CEU-SiO
I. CEL CH ₀ CH ». Si-O-Si-O T ³ Themselves. CIL η contains, in which η has a value from 0 to 1000 and R. and Rp can be the same or different and for alkyl groups with 1 to 6 carbon atoms, phenyl, phenoxy, benzyl or haloalkyl groups with 1 to 6 carbon atoms. 3. Binder according to claim 1, characterized in that it is an organosiloxane polymer of F.ormel (CH ₃ ) _3. SiO CII, SiO - - CH 3 y 609824/0351 contains, in which η means a number from 0 to 2000, which is so set is that the polymer has a viscosity of about 300 to 12,500 centistokes at 25 ° C. 4.. Binder according to one of Claims 1, 2 or 3> characterized in that it consists of 60 to 70 wt .- ^ des bituminous material and 30 to 40 wt .- ^ sulfur, based on the weight of the material, and that there is no more than 0.1 wt .- ^ of the organosiloxane polymer, based on the weight of the bituminous material. 5. Binder according to one of claims 1 to 4, characterized in that it is asphalt as the bituminous material contains and that the organosiloxane polymer in a stabilizing amount of about 0.001 wt .- $, based on the weight of the asphalt, is present. 6. A method for producing a binder according to any one of claims 1 to 7, characterized in that one at elevated temperature bituminous material, molten sulfur and a mixture of liquid which stabilizes the emulsion Organosiloxane polymers with the formation of an emulsion, the continuous phase of which is made up of bituminous material and which are dispersed Phase consists of molten sulfur, mixed together. 7. The method according to claim 6, characterized in that that you 60 to 70 wt .-% of the bituminous material and 30 to 40 wt .-% molten sulfur based on the total weight of the mass, and not more than 0.1% by weight of the stabilizing 609824/0951 Organosiloxane polymers based on the weight of the bituminous Materials mixed together. 8. The method according to claim 6 or 7, characterized in that the organosiloxane polymer is a polymer the formula -SiO-Si (CH-),
OHL η in which η has a value from 0 to 2000, which is a viscosity from about 300 to about 12,500 centistokes at 25 ° C. 9. A method according to any one of claims £> to 8, characterized in that one carries out the mixing at a temperature of about 130 to about 15O ⁰ C. 10. The method according to any one of claims 6 to 9 »characterized in that the emulsion formed is ^{stored in a thermostatically controlled vessel at a temperature of 125 to 145 0} C with gentle agitation. 11. The method according to any one of claims 6 to 10, characterized in that the components are mixed of the binder through an in-line static mixer . 6098 2 4/0951 directs that several baffles to subdivide the flow and to achieve radial mixing of the material on v / eist, the sulfur and the bituminous material being in the middle Entrance to the mixer are merged. 12. The method according to claim 11, characterized in that that the constituents of the emulsion are passed through at a flow rate in the range from 30.5 cm / sec to 762 cm / sec directs the static mixer. 13. Use of a binder according to one of claims 1 to 5 for the production of a floor covering or road surface material. 14. Use according to claim \ L3, for the production of a floor covering or paving material which is about 85 to 95 wt .- ^ contains mineral aggregates and 5 to 15% by weight of the binder. 15. Use according to claim 13 or 14, characterized in that the individual components of the binder, the liquid bituminous material, liquid sulfur and an emulsion-stabilizing amount of the organosiloxane polymer, as well as a predominant part of a mineral aggregate mixed at elevated temperature. 16. Use according to any one of claims 13 to 15, characterized in that the mixing is carried out by simultaneous Introducing the ingredients into a mixing bowl, 609824/0951 which contains the mineral aggregate. 609824/0951