Patent Application
20080070818
The toluene, methanol, water and initial oil were weighed into a 2 litre reaction vessel. The vessel was set up for reflux and heated to 40° C. using the above heating profile. The mixture was stirred at 200 rpm. Calcium hydroxide was added at 33° C. At 40° C. stirring was increased to 400 rpm and the sulphurized dodecylphenol (and alkylbenzene sulphonic acid, if required) were run in over a period of approx. 25 minutes. The prep was then cooled back to 28° C.
At 28° C. carbonation was started at a rate of approx. 150 ml min−1. Carbonation time was 180 minutes.
Heat soak: after carbonation the mixture was ramped from 28° C. to 60° C. using the above profile. The stearic acid was added at 60° C. at the end of the heat soak. After adding the stearic acid the reaction vessel was rearranged for distillation and a blanket of nitrogen was applied. The mixture was stripped according to the above profile. The second oil charge was added at 120° C.
Centrifugation: The product was decanted into a 3 litre beaker and weighed. A further toluene charge was added to the beaker and stirred. The mixture was transferred into centrifuge cans and spun in a centrifuge at 2500 rpm for 30 min. After spinning the mixtures were decanted to be stripped on a rotary evaporator.
Rotary Evaporator Strip: The oil bath was pre-heated to 160° C. and was maintained at this temperature ±10° C. An empty 2 litre pear shaped flask was placed on the rotovap, spun briskly and a vacuum of approx. 400 mbar was applied. The supernatant liquid was then bled in slowly over approx. 40 min. and the solvent allowed to flash off. After all the mixture had been added the vacuum was increased to full vacuum and maintained for 1 hour. After 1 hour the vacuum was released and the product was cooled.
The overbased detergent produced had the following characteristics:
The detergents in the table above were tested for their rates of neutralization using the following test method:
A 100 ml two neck round bottom flask was fitted with a digital manometer (Digitron model 2083) and an injection port consisting of a glass tap and quick fit adapter. The flask was charged with 30 g of sample (to 0.1 mg) and a magnetic stirrer added. The flask was placed in an oil bath at 40° C.±1° C. and the sample was allowed to reach equilibrium. 0.182 g of 18M sulphuric acid was charged to a syringe and injected into the flask via the injection port and the pressure of the CO2 gas evolved was recorded as a function of time. The results are shown in the table below and also in the attached graph.
The amount of dodecyl phenol (DDP) and its calcium salt was measured as follows:
The determination of dodecyl phenol (DDP) and its calcium salt content was done by reverse phase HPLC using a u.v. detector. Alkylphenol species were differently eluted within ten minutes. The remaining sample impurities were washed out from the column with pure methanol A series of four calibration standards were prepared by dissolving known amounts of reference DDP in the mobile phase (84% methanol-16% water), concentrations were selected according to the most appropriate range of detector response factor and linearity. Analyses of test specimens were carried out within the calibration range of response. About 0.3 g of sample solution was dissolved in about 3 g of dichloromethane (AR grade). The solution was gently agitated. A 20 ml volumetric flask was half filled with the mobile phase and into this, about 2.6 g of the dichloromethane solution was directly weighed (to nearest 0.1 mg). The sample was homogenised by agitation or by sonication in a water bath for 2 minutes. The flask was diluted to volume with mobile phase and then, by means of a 5 mL plastic syringe and a 0.45 μm disposable cellulose acetate filter, the sample was filtered directly into the HPLC vial. The sample and calibration solutions were chromotographed using the HPLC conditions below. Integration of the peaks was carried out between 4 and 9 minutes, the baseline being flat (the slope being less than 5%) with no drift of the u.v. detector. The reference point for the baseline was taken at 9 minutes. A linear calibration curve was generated by plotting the integrated areas of the standards against the amount of DDP used to prepare the standards. This calibration curve was used to determine the content of DDP and its calcium salt by combined mass % in the sample.
The HPLC was run with the following conditions:
Flow rate: 1.2 mL/min;
Mobile phase: methanol 84% and water 16%;
Typical injection volume: 5 μl;
Total run time: 38 min;
0-10 min 84% methanol-16% water;
10.10-20.00 min 100% methanol (column wash);
20.10-38.00 min 84% methanol-16% water;
Temperature of the column compartment: 40° C.;
UV detector settings: Wavelength: 230 nm (reference at 360 nm for DAD systems).
The results above show that the use of an overbased sulphurized metal phenate including less than 6.0% by mass of unsulphurized C9-C15 alkyl phenol and its unsulphurized metal salt unexpectedly produces a higher rate of acid neutralization than the use of an overbased sulphurized metal phenate including more than 6.0% by mass of unsulphurized C9-C15 alkyl phenol and its unsulphurized metal salt.
| Number | Date | Country | Kind |
|---|---|---|---|
| 06120924.3 | Sep 2006 | EP | regional |
