HYDROCARBON EMULSION AND USE THEREOF

Abstract: Hydrocarbon emulsion comprising an aqueous emulsion of hydrocarbon, characterized by containing, as an emulsifier, a mixture of at least two different tensides A and B, of which tenside A is present in the emulsion in an amount of 0.1-5 percent by weight and is of a non-ionic character and is chosen among adducts of primary alcohols and ethylene oxide with 20-50 EO units, and tenside B is present in an amount of 0.1-20 percent by weight, calculated on the total emulsion, and is of a cationic character and has general formula (I), wherein B is a C10-C25 alkyl or alkylene group and R<1> is hydrogen or methyl, the hydrocarbon component being present in an amount of 0.2-40 percent by weight of the emulsion and is chosen among non-polar hydrocarbons such as kerosene, naphta, paraffin oil and similar. Also the use and the process for using the emulsion are described.

Description: HYDROCARBON EMULSION AND USE THEREOF The present invention relates to a hydrocarbon emulsion and its use for preventing adhesion of asphalt to rubber cylinders or wheels and to a process for preventing such adhesion. For asphalt-surfacing of roads planing rollers are used for the packing and planing of the asphalt, which plaining rollers are provided with two or three cylinders (or wheels). These cylinders have earlier most often been made of steel without a surface coating, but during recent, time rubber-coated cylinders have been used as one or more of the wheels. The reason therefor is that a certain texture of the road surface may be achieved, which is of advantage from the traffic security point of view and also a lesser amount of noise from the machine. The use of rubber-coated cylinders has, however, the disadvantage that the asphalt has a tendency to adhere to the rubber, which it does not do to a pure steel surface. Attempts have been made to prevent that asphalt adheres by the application of hydrocarbons to the rubber surface, such as diesel oil. However, such oils contain aromatics and are volatile and thus unsuitable for health and environmental reasons. One purpose of the present invention is to provide a means which enables the use of planing rollers with rubber-coated cylinders (wheels) for the compression and planing of asphalt-surfaces of roads and similar. Another purpose of the invention relates to the use of a means for application onto rubber-coated cylinders and wheels of planing rollers in connection with the deposition of asphalt. During the use according to the invention the rubber-coated cylinder wheel in operation is coated with an aqueous emulsion of a hydrocarbon in which a mixture of two (or several) tensides (emulsifiers) , A and B, are used. The means according to the invention is an aqueous hydrocarbon emulsion which, as an emulsifier, contains a mixture of two or several tensides A and B. The tenside A is of a non-ionic character and is an adduct of a primary alcohol and ethylene oxide with 20-50 ethylene oxide units. The tenside B is a fatty tenside of a cationic character and has the general formula R 1 I R-CO-N-CH 2 COOH wherein R is a c τn~ C 25 ^^Y^ or alkylene group and R is hydrogen or methyl. When the emulsion is applied on the rubber cylinders of a planing roller the tenside B will be trans¬ ferred from the emulsion to the rubber surface and due to its "fatty" character adhere to the rubber cylinder and form a layer which prevents asphalt to adhere to the rubber. The mechanism for the transfer of tenside B to the rubber surface can be somewhat different depending on the character of the emulsion. The tenside A is of a tenside with a relatively long ethylene oxide chain (20-50 EO units). During the emulsification, which in this instance is performed with high energy (dissolver) the tenside B will form a "skin" around the dispersed hydrocarbon particles with its hydrophobic carbon chain oriented towards the interior of the hydrocarbon droplet, whereas the tenside A is oriented on the particle surface with the long hydrophilic ethylene oxide chain out towards the aqueous phase, the chains causing a certain degree of entanglement and thus bind the emulsified particles in a network. The emulsion is very stable and is storable during a long time. When, however, the emulsion is submitted to an outer pressure (between the road surface and the rubber cylinder) the emulsi¬ fied hydrocarbon particles with their tenside skins cannot separate since they are fixed to each other by the tenside A. The result is that the skin will burst, the contents (the hydrocarbon) will flow out and evaporate at the existing temperature (about 80-130°C) and the "fatty" tenside B will adhere to the rubber cylinder. The hydrocarbon component of the emulsions according to the present invention is an organic substance which is liquid at room temperature and able to dissolve the tenside B, preferably a non-polar hydrocarbon, such as kerosene, naphta, paraffin oil or similar, preferably substances which are volatile at about 80-130°C. The hydrocarbon component is present in an amount of 0.2-40 percent by weight, suitably 1-40 percent by weight of the finished emulsion, preferably 5-20 percent by weight. The tenside A, which is of a non-ionic character, is present in an amount of about 0.1-5 percent by weight, preferably 0.3-3 percent by weight. The tenside A is chosen, as mentioned above, among adducts of primary alcohols and ethylene oxide. These adducts shall contain 20-50 EO units, suitably 30-40 EO units. A suitable adduct is for instance a nonylphenol/- ethylene oxide adduct. The tenside B is a fatty acid/nitrogen adduct with the formula R 1 I R-CO-N-CH 2 COOH wherein R is a C;ig~ C 25 alkyl or alkylene group and R is hydrogen or methyl. An especially suitable form is a compound wherein R-CO- is oleyl and R is CH,, i.e. oleyl-sarcosine. The tenside B is present in an amount of 0.1-20 percent by weight, preferably 0.5-5 percent by weight of the finished emulsion. The invention is further illustrated by means of the following examples. Example 1 10 parts by weight of kerosene (low-aromatic, about 2% aromatics) 2.0 parts by weight of Tenside B (oleyl sarcosin) 1.7 parts by weight, of Tenside A 26.3 parts by weight of water 100 The oleyl-sarcosine was dissolved in the kerosene. The tenside A was dissolved in the water. The kerosene solution was poured slowly with powerful agitation, into the aqueous solution at room temperature. The tenside A was a C, 6 -C, g alcohol/ethylene oxide adduct, EO = 30. The finished emulsion was tested in field tests on a planing roller with rubber cylinders. No adhesion of asphalt could be detected. Examples 2-5 Example 2 3 4 5 Kerosene 7.1 5.0 5.0 7.1 Tenside B 3.5 - 3.0 3.5 Tenside A 1.9 7.0 7.0 - Water 87.5 88.0 85.0 89.4 100 100 100 100 Emulsion stability good bad 24h bad 24h bad 24h 1 month undissolved undissolved no emulsion lumps of lumps of was tenside A tenside B obtained Bitumen- rejecting effect good _* _* _* * In examples 3-5 no emulsions were obtained, and, accordingly, the testing of the bitumen-rejecting effect could not be performed. The preparation of the composition of examples 2-5 was made according to example 1. The stability of the emulsion was assessed after 24 hours and 1 month. The bitumen-rejecting effect was tested in a so called concrete laboratory in the following manner-. A rubber-coated cylinder, loaded with 50 kgs, operated by hand, was drawn over an asphalt-coating with a higher content of bitumen than is customary in practice. This means that the coating used in the test had a greater "picking-up" tendency (tendency to adhere) than a common road-surface coating. The cylinder was continuously wet with the emulsion. After 20 passages over the three meter long asphalt coating the cylinder was weighed so as to determine picking-up, if any. According to the weighing results no picking-up of bitumen or asphalt had occured. The cylinder which was continuously wet with the emulsion was compared with a cylinder wet with diesel oil. Diesel oil is regarded to function perfectly for this pupose but must not be used for environmental and health reasons. It was established that the emulsion according to the invention functioned as well as diesel oil with continuous wetting.

Claims: CLAIMS 1. A hydrocarbon emulsion comprising an emulsion of hydrocarbon in water, c h a r a c t e r i z e d by using a mixture of at least two different tensides A and B as an emulsifier, wherein tenside A is present in the emulsion in an amount of 0.1-5 percent by weight and is of a non-ionic character and is chosen among adducts of primary alcohols and ethylene oxide with 20-50 EO units, and tenside B is present in an amount of 0.1-20 percent by weight, calculated on the total emulsion, and has a cationic character and has the general formula R 1 I R- CO -N-CH 2 COOH wherein R is a ,-,-C 25 alkyl or alkylene group and R is hydrogen or methyl, the hydrocarbon component of the emulsion being present in an amount of 0.2-40 percent by weight of the emulsion and being chosen among non-polar hydrocarbons such as kerosene, naphta, paraffin oil and similar. 2. Hydrocarbon emulsion according to claim 1, c h a r a c t e r i z e d in that R in tenside B is methyl. 3. Hydrocarbon emulsion according to claim 1 or 2, c h a r a c t e r i z e d in that the group R-CO- in tenside B is oleyl. 4. The use of a hydrocarbon emulsion comprising an emulsion of a hydrocarbon in water, wherein a mixture of at least two different tensides A and B is used as an emulsifier, of which tenside A is present in the emulsion in an amount of 0.1-5 percent by weight and has a non-ionic character and is chosen among adducts of primary alcohols and ethylene oxide with 20-50 EO units, and tenside B is present in an amount of 0.1-20 percent by weight, calculated on the total emulsion. and has a cationic character and the general formula R 1 I R-CO-N-CH 2 COOH wherein R is a C 1Q -C 25 alkyl or alkylene group and R is hydrogen or methyl, and wherein the hydrocarbon component is present in an amount of 0.2-40 percent by weight of the emulsion and is chosen among non-polar hydrocarbons, such as kerosene, naphta, paraffin oil and similar, for wetting rubber-coated cylinders and wheels of road-planing roller machines for preventing adhesion of asphalt thereon. 5. The use according to claim 5 or 6, cc hh aa rr a c t e r i z e d in that the R in tenside B is methyl . 6. The use according to claim 7, c h a r a c t e r i z e d in that tenside B is oleoyl-N-methylglycine. 7. A process for preventing adhesion of asphalt compounds to rubber-coated cylinders or wheels in road-planing rollers, c h a r a c t e r i z e d by pouring onto the rubber-coated cylinder or wheel, during operation, an emulsion of hydro¬ carbon in water, in which a mixture of at least two different tensides A and B is used as an emulsifier, wherein tenside A is present in the emulsion in an amount of 0.1-5 percent by weight and is of a non-ionic character and is chosen among adducts of primary alcohols and ethylene oxide with 20-50 EO units, and tenside B is present in an amount of 0.1-20 percent by weight, calculated on the total emulsion, and is of a cationic character and has the general formula R 1 I R-CO-N-CH 2 COOH wherein R is a C, Q -C 25 alkyl or alkylene group and R is hydrogen or methyl, the hydrocarbon component being present in an amount of 0.2-40 percent by weight of the emulsion and being chosen among non-polar hydrocarbons such as kerosene, naphta, paraffin oil and similar. 8. A process according to claim 7, c h a r a c t e r i z e d by using a hydrocarbon emulsion according to claim 2 or 3.

Inventors: BIVERSTEDT ARNE, BREDENBERG BO, BIVERSTEDT, ARNE, BREDENBERG, BO
Applicants: BECKER WILHELM AB, AB WILH BECKER
Application year: 1988
Main classification: B01F17
IPC codes: B01F17