5316 5320.output

* GB785723 (A)

Description: GB785723 (A) ? 1957-11-06

Process of electrolysis of aqueous electrolytes for producing bromine andiodine

Description of GB785723 (A)

PATENT SPECIFICATION vcnttors: OZJASZ SCHACHTER and SZMUEL EZMNIK Date of Application and filing Complete Specification April 20, 1955. No 11450/55. A I/ Complete Specification Published Nov 6,1957. Index at acceptance: -Class 4 A, A( 2 81: 2 H: 9), 32 (A: F: X). International Classification: -C 23 b. COMPLETE SPECIFICATION Process of E Rlectrolysais of Anquseous l E Rertirolytes for Producing Bromii^ e and l Rodine We, MAKHTSAVEI ISRAEL, an Israeli Body Corporate, of Hakiria, Tel-Aviv, Israel, do hereby declare the invention, for which we pray that a patent may be granted to us, annd the method by which it is to be performed, to be particularly described in and by the following statement: - This invention relates to the electrolysis of aqueous electrolytes for producing bromine or iodine by processes in which the products obtained at the anode and cathode, respectively, tend to react with one another chemically if they are allowed to mingle in the aqueous medium. Electrolytic processes in which none of the reaction products escapes in gaseous form but the reaction products have to be separated from one another in liquid form for the aforesaid reason, are hitherto carried out in cells provided with diaphragms These cells are relatively costly, and in their operation there arise problems of corrosion and clogging A diaphragm-less cell, the so-called bell-jar cell, is known for the manufacture of chlorine In this cell the anolyte is separated from the catholyte by a neutral zone of the electrolyte located below the anode The location nf the neutral zone in the cell is not stable, as owing to the difference in the velocity

of migration of the hydrogen and hydroxyl ions, respectively, the zone tends to be shifted towards the anode In order to counteract this displacement the fresh brine is supplied to the cell from above into the region of the anode above the neutral zone which is thereby kept down The chlorine escapes as a gas through an outlet provided above the anode. This known cell cannot be used for the production of bromine or iodine since, being heavier than water, these two elements would, at the moment of their formation, sink down, pass the neutral zone and react with the Na OR of the catholyte to form Na Br O and Na IO, respectively. lPrice _ It is a primary object of the invention to 45 provide a continuous electrolytical process for aqueous electrolyte containing bromine and iodine which can he carried out in a simple apparatus without a diaphragm. The invention has the further object of pro 50 viding a process for the electrolysis of bromide or iodide solutions containing at least two different cations of which one forms a watersoluble hydroxide and the other one a waterinsoluble hydroxide, the process being so 55 directed as to produce the whole or a substantial part of the total hydroxide in the form of said water-insoluble hydroxide and to allow this to settle as a sediment in a part of the apparatus from which it can be removed with 60 out interruption of the electrolysis In particular, the invention provides a continuous electrolytical process for the production of pure magnesium hydroxide from aqueous bromide or iodide solutions in which magne 65 sium is only one of the cations. The invention consists in a continuous process for the electrolysis of aqueous bromide or iodide solutions substantially without formation of gaseous products of electrolysis at the 70 anode and without separation of the anolyte from the catholyte by a diaphragm, wherein a stream of fresh electrolyte is fed immediately into the electro-chemically neutral zone of the aqueous medium between the anolvte and 75 ratholyte. Preferably, the current is made to pass between electrodes disposed mainly in the upper part of an electrolytic cell, both the anolyte and catholyte are withdrawn from the 80 upper part of the cell and the fresh electrolyte is fed into the electrochemically neutral zone below the reach of the electrodes and the anolyte and catholyte drains and is made to flow upwards so as to prevent the free halogen 85 formed by the electrolysis from dropping into and through the neutral zone. Where the electrolyte consists principally of 785,? 23 alkali bromide or iodide, the product obtained at the cathode is alkali hydroxide which tends to some extent to diffuse back into the neutral zone and further into the anode space, thus diminishing the current efficiency

It has, therefore, been found to be advantageous to admix the electrolyte with salts of metals whose hydroxides are insoluble or difficultly soluble in water, such as magnesium or calcium Magnesium salts happen to be present anyway in many natural brines or residual industrial liquors which come into regard as sources for the production of bromine or iodine, such as sea-water, the water of some salt lakes such as the Dead Sea, or mother liquors remaining from the manufacture of sodium chloride from sea-water, the manufacture of carnallite from natural salt deposits or salt lakes, or the like Where such liquors are subjected to electrolysis by the process according to the invention, the principal products are bromine on the one hand and a highly pure magnesium hydroxide on the other hand The purity of the magnesium hydroxide thus obtained makes it even worthwhile to add magnesium salt, e g chloride, to alkali halide electrolytes with the main object of producing pure magnesium hydroxide. Calcium hydroxide is more soluble in water than magnesium hydroxide, and the current efficiency is, therefore, lower in the case of precipitation of calcium hydroxide than in the case of magnesium hydroxide. Where the proces according to the invention serves for the preparation of bromine, the rate of inflow of brine can be so regulated that the anolyte is an aqueous bromine solution from which the bromine can be recovered in any suitable way, e g by solvent extraction If the bromine is liberated by secondary reaction of the bromides of the brine with the chlorine set free from the chlorides of the brine by electrolysis, the brine inflow should be so regulated that about 2 % of the bromides remain undecomposed, in order to avoid the formation of chlorine-bromine compounds. The accompanying drawings show diagrammatically in axial section two cells for performing electrolytic processes according to the invention. Fig 1 shows a cell of small laboratory dimensions; Fig 2 illustrates a cell designed for commercial use. The cell according to Fig 1 consists essentially in an upright U-shaped glass vessel 1. The upright tube 2 of the vessel 1 is the anode space, the left-hand tube 3 is the cathode space The tubes 2 and 3 are provided each with overflows 4 which open into drains 5, 6, provided with cocks 7, 8, respectively The upper ends of the drains merge into vents 9. A feeding pipe 10 provided with cock 11 opens into the horizontal bottom stretch of the vessel 1 substantially in the center thereof. The " plus " signs in the anode space, and the " minus " signs in the cathode space, indicate that the liquid in these spaces is not neutral electrochemically, the p H being clearly below 7 in tube 2, and above

7 in tube 3 The liquid 70 in the bottom stretch of the glass tube, in which the supply pipe 10 opens, is electrolytically neutral, i e at a p H of 7 or in the vicinity of 7 The approximate boundaries of this neutral zone are indicated by dashed lines 75 The anode space contains a graphite anode 12 which is a rod secured in an axially bored stopper 13 which tightly seals the tube 2 A current lead 14 is connected to the top end of the anode 80 A cathode 15, e g an iron cylinder, is disposed in the cathode space, being freely suspended from any suitable support above the cell by means of the current lead wire 16. Fresh electrolyte is supplied continually 85 through pipe 10, and liquid flows out continually through both pipes 5 and 6 If, for example, sea-water or salt pan brine is the electrolyte, the anolyte flowing out through drain 5 is an aqueous solution of bromine, 90 possibly containing some iodine, while the catholyte flowing out through the drain 6 contains alkali hydroxide Besides, magnesium hydroxide separates in the tube 3 and gradually clogs the latter 95 This cell is destined for experimental or demonstration purposes only, and it has been shown here merely because it illustrates the principle of the present invention in an especially simple way 100 The electrolytic cell illustrated in Fig 2 is designed for operation on a commercial scale It comprises an upright cylindrical vessel 17 of stainless steel made integral with a jacket 18 which is provided with an inlet 19 and an out 105 let 20 for a coolant, e g water The inclined bottom 21 of the vessel 17 supports the legs 23 of a cup-shap;d receptacle 22 of stinless steel A cylindrical chamber 24, also of:ainless steel and co-axial with the receptacle 22 110 and the vessel 17, is disposed above the receptacle 22 and dips into the latter, and an annular passage 25 between the receptacle 22 and chamber 24 makes the interior of the chamber 24 (anode space) communicate with 115 that of the vessel 17 (cathode space) The chamber 24 is secured, e g welded, to its lid 26 which is clamped between nuts 28 screwed on bolts 27 The latter are fixed to a cover 29 which rests unconnectedly on the common 120 upper edge of the vessel 17 and jacket 18 and has in its middle a sleeve 30 for guiding the chamber 24 The latter can be raised and lowered relative to the receptacle 22 by a corresponding adjustment of the nuts 28, 125 whereby the length of the passage 25 can be varied with a view to preventing the liquid contained in the anode space from mingling with that contained in the cathode space. The lid 26 is provided with a tubular con 130 785,723 nection 31 co-axial with the chamber 24 A red-shaped anode 32, e g of graphite, is fixed to a cap 34 which rests on the upper end of the tube 31 and is insulated electrically from the latter The anode hangs down through the tube 31 into the chamber 24 and ends substantially flush with the

bottom end of the chamber where it merges preferably with a disc 33 of the same material as the remainder of the anode A current lead 35 is connected to the cap 34 The tube 31 has a lateral extension 36 serving as a vent for the anode space. The annular cathode space between chamber 24 and the wall of vessel 17 contains a cylindrical cathode 37, e g of iron, which is fixed in any suitable manner, e g suspended from a rod 38 which rises out of the cathode chamber through an opening 39 in the cover 29 and serves also as a current conductor. A supply pipe 40 traverses from outside the jacket and cathode space and penetrates into the receptacle 22 which contains the electrochemically neutral portion of the liquid in the cell A distribution head 41 may be provided at the downwards bent end of pipe 40. The cell is provided with three outlets, namely, an anolyte overflow 42 comprising a vertical stretch within the anode space where its upper end defines the high-level of the anolyte, which is located in the upper part of the cell, while the lower part of the anolyte drain passes outwards through the receptacle 22, the cathode space and the jacket; a catholyte overflow 43 passing from the cathode space outwards through the jacket substantially at the level of the upper end of the anolyte overflow; and a sediment drain 44 connected to the deepest region of the cathode space Control valves, which have not been shown, will be provided for the supply pipe and all the drains. The surfaces of the cell liable to become corroded by contact with the products of the electrolysis specially the inner surface of the anode space and the anolyte drain are preferably coated with a corrosion-resistant matter, e.g a layer of baked-on phenol-formaldehyde resin. Owing to the fact that fresh electrolyte is fed into a zone below the reach of both electrodes and has to flow upwards in the cell, neither the free halogen formed in the anode space nor the metal hydroxides forming in the cathode space can drop into the neutral zone whose position within the cell thus remains stable This stability of the neutral zone is also enhanced by the fact that both the anolyte and catholyte are drained from the upper part of the cell. The invention is illustrated by the following examples to which it is, of course, not limited. In all these examples, a cell of the kind illustrated in Fig 2, may be used, but the dimensions of the cell and the input of electrolyte and output of anolyte and catholyte are described on a small laboratory scale For the figures given in the examples, a cell with a capacity of 250 ml of total liquid is sufficient. Enlargement of the cell to dimensions suitable for the commercial

performance of the 70 process will entail a correspondingly larger input and output, but no alternation in principle. Ex AMPLE 1 An electrolyte, being an aqueous solution 75 containing per liter:gms. Mg GI, 330 Ca C 12 110 Mg Br, 13 8 80 Na Cl 10 KCI 10 is fed to the cell through the pipe 40 at a rate of 0 160 liters per hour The current is 0 5 amp, the voltage 4 volt, the temperature is 85 maintained at 20-30 C by the circulation of water through the jacket 18 The anolyte is withdrawn at a rate of 0 126 liters per hour, and catholyte at a rate of 0 034 liters per hour. During the electrolysis, magnesium 90 hydroxide precipitates, and owing to the slope of the bottom 21, the sediment collects in the deepest zone of the cell from which it can be removed from time to time by opening the valve controlling the drain 44 The magnesium 95 hydroxide thus withdrawn has, after washing with water, a degree of purity of 99 5 % and above. The total quantity of 0 756 liter of anolyte withdrawn during 6 hours is shaken in a 100 separating funnel with 30 ml of ethylene dibromide, and the layers are separated The solvent layer contains bromine in a concentration of 135 gms per liter whereas the bromine concentration of the aqueous liquor has 105 dropped 4 8 gms per liter The extraction is repeated twice each time with 30 ml of ethylene dibromide and again twice with 15 ml. each of ethylene dibromide. About 8 3 gms of bromine, viz 98 % of 110 the total bromine produced, can be recovered from the combined extracts. At the end of the same period the total weight of the magnesium hydroxide precipitate is 2 76 gms 115 The anodic current efficiency is 93 %, the cathodic current efficiency 85 %. EXAMPLE 2 The electrolyte is composed as follows:gms /ltr 120 Mg CL, 130 Ca CI, 38 Mg Br 4 6 Na CI 80 KC 1 11 125 The other data are as in Example 1, but the rate of feed of the electrolyte is 0 500 litres per hour, the anolyte withdrawal is 0 370 litres per hour, the catholyte withdrawal 0 130 litres per hour Yield after 6 hours: 8 5 grns of bromine, 2 76 gins, of Mg(OH)2 The anodic current efficiency is 95 %, the cathodic current efficiency 85 %. EXAMPLE 3 The electrolyte is composed as follows:gms /ltr. Na Cl 100 K Br 149 K 2 Cr O 4 2 The other data are as in Example 1, but the rate of feed of the electrolyte is O 150 litres per hour, the anolyte withdrawal is 0 080 liter per hour, and the catholyte withdrawal 0 070 liters With an anode current efficiency of %, a total amount of 4 0 gms of bromine is obtained from 0 480 litres of anolyte

after 6 hours. EXAMPLE 4 The electrolyte is composed as follows:gms /ltr. Na CI 100 Mg Cl, 50 K Br 10 The other data are as in Example 1, but the rate of feed of electrolyte is 0 174 litres per hour, the anolyte withdrawal is 0 154 liters per hour, and the catholyte withdrawal is 0.020 liters per hour The current efficiency is '0 % at the anode and 80 % the cathode. After 6 hours, 7 1 gms of bromine can be recovered from 0 924 liters of anolyte, while the weight of magnesium hydroxide precipitate after 6 hours is 2 6 gmns. EXAMPLE 5 The electrolyte is composed as follows: gms /ltr. Na CI 100 Ca Ci 2 100 K Br 10 The remaining data are as in Example 1, but the rate of feed of electrolye is 0 150 liters per hour, the anolyte withdrawal is 0 108 liters per hour, and the catholyte withdrawal is 0 042 liters per hour. After 6 hours, 5 4 gms of bromine can be recovered from 0 648 literis of anolyte withdrawn The anodic current efficiency is 60 %. EXAMPLE 6 The electrolyte is composed as follows:gms /ltr. Na Cl 100 Mg C 12 50 KI 1 The remaining data are as in Example 1, but the rate of feed of electrolyte is 2 442 litres per hour, the anolyte withdrawal is 1642 liters per hour, and the catholyte withdrawal is 0.800 liters per hour At the end of 6 hours, 7 4 gms of iodine can be recovered from 9852 liters of anolyte withdrawn Recoverey can be effected by solvent extraction in a manner similar to that applied for the recovery of bromine (see Example 1) The anodic current efficiency is 52 %. EXAMPLE 7 End-brine from evaporation pans of ocean water was used as electrolyte A partial analysis showed the following composition per liter:gms. Cat+ 0 02 Mg++ 46 8 Cl 200 7 Br. 2 1 75 The brine, like ocean water in general, has a p H above 7 An addition of acid is therefore required in order to prevent the formation of hypobromite The acid may be added either to the incoming electrolyte or to the anolyte after 80 electrolysis If sulphuric acid is used, an addition of 0 85 gins per liter of the above brine is sufficient The other data are as in Example 1 but the rate of feed of the electrolyte is O 50 liters per hour, the anolyte withdrawal is 0 750 85 liters per hour, the catholyte withdrawal 005 liter per hour The total yield after 7 hours is 5.25 liters of anolyte containing 1 9 gms of bromine per liter, and 0 35 liter of catholyte containing magnesium hydroxide The quan 90 tity of bromine obtained corresponds to a current yield of 95 %.

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* GB785724 (A)

Description: GB785724 (A) ? 1957-11-06

New cyclic alkanediol esters of alkyl boronic acid and motor fuelscontaining these esters

Description of GB785724 (A) Translate this text into Tooltip

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The EPO does not accept any responsibility for the accuracy of data and information originating from other authorities than the EPO; in particular, the EPO does not guarantee that they are complete, up-to-date or fit for specific purposes.

PATENT SPECIFICATION Invenor: SAMUEL M DARLING -LJULV vl ripiiint q No 16220/55. Complete Speci 7 tion and filing Complete Specification: June 6, 1955. fication Published: Nov 6, 1957. Index at acceptance:-Classes 2 ( 3), B 4 (F: H); and 91, Gl AL. International Classification:-CO 7 d C 10 g. COMPLETE SPECIFICATION New Cyclic Alkanediol Esters of Alkyl Boronic Acid and Motor Fuels containing these Esters We, THE STANDARD OIL COMPANY, a Company incorporated under the laws of the State of Ohio, United States of America, of Midland Building, Cleveland 15, Ohio, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be

performed, to be particularly described in and by the following statement:The present invention relates to cyclic alkanediol esters of alkyl boronic acids and to a liquid hydrocarbon motor fuel containing minor amounts of one or more of said esters. It is well known that the performance of an internal combustion engine is deleteriously affected during operation by the formation of deposits in the combustion zone and on the piston skirt and the piston rings. The deposits formed in the combustion zone, particularly on the piston head and the exhaust valves, appear to have the most immediate effects upon engine performance in that their presence requires a fuel having a higher octane rating in order not to knock, than is required by a new or clean engine. This means, in other words, that the octane value of a fuel required by an engine containing deposits in the combustion zone in order not to knock (referred to hereinafter as "octane requirement") is higher than the octane requirement of a clean engine For example, a clean engine which requires a gasoline having an octane rating of 60 in order not to knock is said to have an octane requirement of 60 If the same engine, when dirty, i e, with deposits in the combustion chamber, requires a gasoline having an octane rating of 75 in order not to knock, such an engine is said to have an octane requirement of 75, or an "octane requirement increase" of 15 If a clean engine starts to get dirtv, the octane requirement rises with continued use Finally there is no more octane requirement increase with continued use and apparently the engine has then become as dirty as lPrice 3 s 6 d l it is ever going to be with continued use or, if it becomes dirtier after a certain point, it does not require a gasoline of greater octane value in order not to knock. It has previously been found, for example, that the weight of material deposited upon the top or head of the piston reaches a maximum in a single cylinder F-4 engine after approximately 20 hours of operation and that thereafter it decreases slightly, possibly due to a flaking action, until it levels off after about 40 hours of operation It has also been found that the weight of the material deposited upon the exhaust valves reaches a maximum in the same engine after about 30 hours of operation and thereafter it decreases slightly and levels off after about 40 hours of operation The fact that the weight of deposits in the combustion zone first reaches a maximum value and then levels off to a somewhat lower value while the octane requirement levels off at the maximum value is believed to disprove the formerly accepted theory that the octane requirement of an engine is proportional to the weight of deposits in the combustion chamber. The undesirable effects of the deposits in the combustion chamber is

further aggravated when tetraethyl lead is contained in the fuel because these deposits then are no' longer primarily carbonaceous but contain appreciable quantities of lead Accordingly, it has been found that the total weight of deposits formed in the combustion zone is appreciably greater when using a leaded fuel than when using a non-leaded fuel The octane requirement increase of an engine operating on leaded fuel, however, is not in proportion to the difference in deposit weights From this it is concluded that the octane requirement increase of an engine is determined not so much by the quantity of material deposited as by its presence and character. It has also previously been found that the increase in octane requirement resulting from the formation of engine deposits is not attributable to a decrease in the thermal conductivity 785724 M-lt ^r Azhhl, 2 785,724 of the surfaces enclosing the combustion zone. Since it has been found that the octane requirement increase of an engine is not determined solely by the quantity of material deposited in the combustion zone and that it is not due to a decrease in the thermal conductivity of the surfaces enclosing said zone, it is believed that it is due to a catalytic action wherein the deposits in the combustion zone act as catalysts to accelerate the oxidation of petroleum hydrocarbons It has, therefore, been suggested that the proper approach to the problem of reducing the octane demand increase of an engine is that of adding to the fuel a substance having an anti-catalytic effect, or, in other words, the effect of suppressing or inhibiting the catalyst properties of the deposits formed, especially the troublesome leadcontaining deposits. In accordance with the aforesaid suggestion it has previously been proposed to add minor amounts of boron in the form of soluble or dispersible boron compounds to the liquid hydrocarbon fuels used in internal combustion engines Among the compounds previously proposed for such purposes are the tri-alkyl borates and the tri-alkyl borines, e g, tri-amyl borine and tri-isobutyl borate Such compounds have been shown to be effective in achieving the desired goal, but their use has been limited to some extent by various deficiencies which generally stem from their susceptibility to oxidation or to hydrolysis by water. In accordance with the present invention, it has been discovered that cyclic di-esters of alkanediols having from 2 to 8 carbon atoms and of a Lkyl boronic acids having from 6 to 10 carbon atoms are surprisingly stable even in the presence of water, are soluble in liquid hydrocarbon motor fuel, and, when added to such a motor fuel, provide a fuel which is capable of preventing substantial increase in the octane requirement of an engine on prolonged operation. Similar compounds not mentioned within the present invention are considerably less resistant to hydrolysis Thus when the tests whose

results are set out in Table II were carried out on the ester made from n-butyl boronic acid and 2,5-hexanediol the hydrolysis in iso-octane was 86 01 % and in gasolene 70.7 % and in the case of the ester made from t-butyl boronic acid and propylene glycol the hydrolysis in iso-octane was 37 5 %, and in gasoline 42 6 % Thus it will be seen that when compounds made from the same diol are compared those according to the present invention are superior to those not included within the present invention. The alkanediol cyclic diesters of alkyl boronic acids which form part of the present invention are prepared by reacting an alkanediol having from 2 to 8 carbon atoms with an alkyl boronic acid having from 6 to 10 carbon atoms While the mechanism of the reaction has not been ascertained with certainty, it is believed that the reactants combine, mol for mol, with the elimination of two molecules of water to form a cyclic compound as illustrated by the following equation: R-B(OH), + HO-R'-OH R-B R' wherein R represents an alkyl radical of 6 to carbon atoms, and R' represents an alkylene radical of from 2 to 8 carbon atoms, 75 preferably a radical of 4 to 8 carbon atoms on which the OH groups are substituted on adjacent carbon atoms or on carbon atoms separated by only one carbon atom. The motor fuel of the invention comprises 80 a liquid hydrocarbon motor fuel which may be either leaded or unleaded and which contains an ester of the above description in an amount sufficient to diminish the octane requirement increase of an internal combustion 85 engine operated on the fuel. The amount of additive to be contained in the fuel is generally very small and is conveniently measured in terms of the amount of boron added to the fuel For most purposes, 90 we have found that the amount of additive should be such that the fuel will contain between about 0 0002 and about 0 02 ' by weight of boron Amounts within the range of about 0 001 to 0 01 % are preferred Reference 95 in this application to boron concentration is intended to refer to the amount of boron in the alkyl boronic acid as a component thereof and not to an amount of boron in its elemental state 100 It is to be emphasized at this point that the boron additives described herein, when added to a motor fuel, are not anti-knock agents in the sense that they increase the octane rating of a fuel as is done by the addition of tetraethyl 105 lead or other known anti-knock agents. In the method of the invention, the optimum results are achieved when operating an initially clean engine but the method also has a gradual beneficial effect in operating a 110 dirty engine Cleaning of the engine, when desirable, may be accomplished by any of several known techniques such as by disassembly and scraping. In the preparation of alkanediol cyclic di 115 esters of alkyl boronic

acids of the invention, the preferred procedure comprises refluxing approximately equimolecular quantities of the appropriate alkanediol and alkyl boronic acids in an inert reaction medium such as an 120 aromatic hydrocarbon, e g, benzene During the reaction, the water is collected in an azeotropic trap The preparation of typical alkyl boronic acids which may be utilized as reactants in this process is described in our co 125 785,724 temperature below 750 C The residue was then placed under vacuum and nitrogen was bubbled through for 15 minutes A light yellow fluid was obtained, a few white crystals remaining in the flask The weight of crystals plus fluid was 37 6 g and the weight of fluid, after filtration, was 36 4 g This amounted to 95.3 % of the theoretical yield The product analyzed as follows: Found Theory pending Application No 16219/55 (Serial No 773,169) The time of the reaction is generally a few hours; in most cases from 5 to 6 hours are sufficient. The following Examples further illustrate the invention Parts and percentages are by weight unless otherwise specified. EXAMPLE 1 A reaction vessel was equipped with a reflux condenser and azeotropic trap Into the vessel there was placed 26 8 g of n-octyl boronic acid, 20 g ( 0 1692 mol) of 2-methyl2,4-pentanediol and approximately 200 il of benzene The mixture was heated and allowed to reflux for about 6 hours, water being collected during the reaction in the azeotropic trap The amount of water so collected was 7 ml, the theoretical amount being 5 8 nil. At the end of the reflux period, the benzene solution was washed five times with 100 ml. portions of water and the benzene was then stripped off by simple distillation keeping the Molecular Weight % Boron Density Refractive Index Boiling Point ( O C) 239,240 240 2 4.15, 4 37 4 50 0.8644 1.4309 ( 2-3 mm) EXAMPLES 2 TO 10 Several other esters were prepared by the procedure of Example 1 The following table shows the reactants and mols thereof utilized in each preparation: TABLE I Example No. Boronic Acid n-hexyl n-hexyl n-hexyl n-hexyl n-hexyl n-hexyl n-octyl n-octyl n-octyl Diol 2,5-hexanediol 2,3-dimethyl-2,3-butane diol 2-methyl-2,4-pentanediol 2,2-diethyl propanediol propylene glycol ethylene glycol 2,5-hexanediol 2,3-dimethyl-2,3-butanediol 2,2-diethyl propanediol Mols Diol Mols Acid 0.015 0.011 0.016 0.011 0.015 0.011 0.015 0.011 0.0029 0.0029 0.0029 0.0029 0.014 0.011 0.014 0.011 0.014 0.011 785,724 EXAMPL Es 11 To 20. Each of the esters prepared in Examples 1 to 10 was added to

iso-octane and to a conventional leaded gasoline in an amount to provide a concentration of 0 004 % boron in each fuel All the fuels were then examined or tested to determine the resistance to hydrolysis by water of the additive contained therein In this test, 900 ml of each motor fuel was placed over the 100 nil of distilled water and allowed to stand in the dark for 144 hours. At the end of this time, the water layer was analyzed for boron content and this value was then subtracted from the amount of boron originally present in the fuel to determine the amount of boron remaining in the fuel The results in the hydrolysis test are reported in terms of per cent of boron remaining in the fuel compared with the amount originally present. The following table gives the results of the hydrolysis tests: TABLE II. % Hydrolysis in Iso-octane 0.18 14.67 1.0 0.91 1.08 8.77 15.91 0.31 0.18 0.18 ' Hydrolysis in Gasoline. 0.26 10.77 1.05 0.91 1.12 10.71 20.45 0.90 0.25 0.29 The results in the table show that the motor fuels of the invention are in general remarkably resistant to hydrolysis in iso-octane and gasoline In view of the known efficacy of boron in preventing octane requirement increase, it is thus indicated that such motor fuels will operate efficiently in minimizing octane requirement increase even in the presence of water It is also evident that the optimum results are obtained when the glycol from which the additive is prepared contains at least 4 carbon atoms and the OH groups are substituted on adjacent carbons or on carbons separated by only one other carbon atom. It is to be understood that the liquid hydrocarbon motor fuel of this invention may be any one of those ordinarily used for internal combustion engines and may contain other ingredients and additives such as antioxidants, gum inhibitors, solvent oils, upper cylinder lubricants, dyes and perfumes ordinarily added to motor fuels The presence of these additives and the amounts normally used does not alter the effect of the additive. Further, it is not intended that the scope of the invention be limited by any theory advanced to explain the action of the additive disclosed as effective in reducing the increase in the octane requirement of an internal combustion engine. Specification No 722537 describes and claims a liquid fuel for internal combustion engines containing dissolved in the liquid fuel an alkyl or cycloalkyl ester of boric acid or of a boronic or borinic acid, said ester containing at least one group of not less than five carbon atoms and containing no group of more than twenty carbon atoms Among the esters mentioned are cyclic esters of alkyl boronic acids derived from dihydric alcohols, e.g 2 4-pentane diol methyl boronate

and hexylene glycol n-butyl boronate.

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* GB785725 (A)

Description: GB785725 (A) ? 1957-11-06

Improvements in or relating to the production of hair dyes

Description of GB785725 (A)

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CH334157 (A) FR1113505 (A) CH334157 (A) FR1113505 (A) less Translate this text into Tooltip



COMPLETE SPECIFICATION Improvements in or relating to the Production of Hair Dyes We, SOCIETE MONSAVON -L'OREALJ a French Body Corporate, of 14, Rue Royale, Paris 8 , France, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following

statement: The present invention relates to the preparation of hair dyes and it is an object of the invention to produce dyes which may be applied directly to the hair at normal room temperatures. By the term "anionic dyestuff" used herein is meant dyestuffs which contain a functionally acid group such as a carboxylic acid, sulphonic acid or phenolic hydroxy group. It is known that many anionic dyestuffs employed for dyeing textile fibres, more especially animal fibres, may be precipitated from their aqueous solutions by adding a molecularly equivalent quantity of basic substanc-s such as substituted guanidines, aminopyrazolones and dicyclohemylamine. The new dyestuffs thus obtained are very frequently sufficinetly soluble in organic solvents to be suitable for use in the colouring of varnishes. It is also known that live hair can be dyed at room temperatures by means of the anionic dyestuffs usually employed for dyeing textile and animal fibres, provided that the hair has previously been impregnated with solutions of products known in e textile industry as " active cation " products. This process enables the hair to be dyed but the dyes are only fixed on the surface, because the dyestuff in contact with the fibre impregnated with active-cation product is immediately precipitated on the surface so that the colour obtained is only moderately resistant to friction and to moisture. Furthermore, the operation must be carried out in two stages. It has now been found possible to dye hair directly at room temperatures in a single operation and with a lasting effect by imprecgnat- ing the hair with a composition containing an anionic dyestuff resulting from the coupling of a diazo compound of an amine of the benzene series with a 2-naphthaleno 8-phenylamino 6-hydroxysulphonic acid (hereinafter referred to as phenyl gamma acid), an activecation product in equimolecular proportion to the anionic dyestuff so as to neutralise the latter, a non-ionic solubilising agent in just sufficient quantity to permit of bringing the anion-cation complex formed into solution in water for the purpose of promoting the penetration of the dye into the hair. Further investigation has shown that the process of preparing a dye from the aforesaid anionic dyestuffs derived from phenyl gamma acid may be generally applied to anionic dyestuffs. According to the present invention, theve- fore, a process for the production of a hair dye suitable for direct dyeing of hair at room temperatures comprises combining equimolecular amounts of an anionic dyestuff of the type herein describ > d and a cation-active compound containing at least 6 carbon atoms whereby a dyeing, anion-cation complex is obtained, and water-solubilising said complex by means of a

quantity of a solubilising agent which is just sufiicient for the purpose and which leaves the molecular anion-cation balance substantially unchanged. The organic base chosen may with advantage be one in which the nitrogen is either trivalent (amine having high molecular weight) or pentavalent (product containing quaternary ammonium). Thus, the molecule of the organic base may be characterised by a lipophilic chain containing inter alia, for example, from 12 to 14 carbon atoms attached to a hydrophilic amine chain. The non-ionic solvents which may be employed as solubilising agents include, more especially, the alcohols and the products of the condensation of ethylene oxide with alcohols, phenols, or naphthols. In a modified embodiment of the process according to the invention, the quantity of solubilising agent (non-ionic solvent) added may be reduced or even omitted by attaching certain solubilising groups to the organic base so that the latter simultaneously performs the function of a solubilising agent with respect to the dyestuff complex and of a neutralising agent for the anionic dyestuff when forming the complex. For example, ethylene oxide may be conK densed with the organic base. The number of ethylene oxide molecules to be condensed depends upon the dyestuff employed. Furthermore, it is desirable in accordance with the invention to adjust the pH value of the dyeing solution by the addition of an organic acid (e.g. lactic add) to bring the pH value lower than 7. Examples of compositions according to the invention will hereinafter be given, these examples not being intended to limit the possible applications of the invention. It should be noted that in all the examples the pH value is preferably between 4.5 and 5.5. For the sake of simplicity, in all the following examples, the anionic dyestuff will be referred to as the "anion" and the organic base associated therewith as the "cation". A-Azo DYESTUFFS EXAMPLE 1 A dye is prepared by solubilising the following insoluble anion-cation complex: g. Anion: Dyestuff known under the name "Bleu chlor antine lumiere GLL" 2 Cation: Product known under the Registered Trade Mark "Lissolamine A" (assumed to be octa

decylpyridinium bro mide) - - - - 0.5 with the product known under the name Cemulsol 132" (product of condensation of a compound containing - a naphthalenic nucleus with ethylene oxide) 1.1 Lactic acid - - - - - 2.5 Water up to - - - - - 100 A light the tint is obtained on natural white hair. EXAMPLE 2 A dye is prepared by solubilising the following insoluble anion-cation complex: g. Anion: Dyestuff known --under the name "Noir diazol E" - - - - - 2 Cation: Ester of fatty acid from copra and diethylethan olamine previously con densed with 4.5 mol. of ethylene oxide - - 1.1 with "Cemulsol 132" - - - - 2.5 Lactic acid - - - - - 2.5 Water up to - - - - - 100 A rather distinguished grey-black is obtained on natural white hair. EXAMPLE 3 A dye is prepared with the following soluble anion-cation complex: g. Anion: Dyestuff known under the name "Noir diazol E" - - - - - 2 Cation: Ester of fatty acid from copra and diethylethan olamine previously con densed with 12 mol. of ethylene oxide 2.5 Lactic acid - - - - - 2.5 Water up to - - - - - 100 In the above example, the condensation of a sufficient number of ethylene oxide molecules on the cation ensures complete water- solubilisation of the anion-cation complex and obviates the necessity

for using a special solubilising agent such as Cimulsol 132. EXAMPLE 4 A dye is prepared by solubilising the following insoluble anion-cation complex: g. Anion: Dyestuff known under the name "Rouge Kiton 6 B" - - - - 2 Cation: Ester of fatty acid from copra and diethylethan olamine previously con densed with 4.5 mol. of ethylene oxide - - 1.7 with "Cemulsol 132" - - - - 1.9 Acetic acid - - - - - 1.7 Water up to - - - - - 100 A pinkish auburn tint is obtained on natural white or light-blond hair. EXAMPLE 5 A dye is prepared by solubilising the following anion-cation complex: g. Anion: Dyestuff obtained by the coupling of the diazo compound of p-nitro-o anisidine with phenyl gamma acid in an alka line medium - - - 2 Cation: Lactate of the esters of fatty acids from copra and diethanolamine previously condensed with 4.5 mol. of ethyl ene oxide - - - 1.8 " Cemulsol 132" - - - - 3.9 Lactic acid - - - - - 8 Water up to - - - - - 100 This dye imparts a violet-grey tone to live hair in the cold or at a temperature below 40 C. EXAMPLE 6 A dye is prepared by solubilising the following anion-cation complex: g. Anion: Dyestuff obtained by coupling the diazo com

pound of meta-amino sulphanilide with phenyl gamma acid in alkaline medium - - - - 0.8 Cation: Product known under the name "Lissolamine A" (octadecylpyridi nium bromide) - - 1 " Cemulsol 132" - - - - 9 Lactic acid - - - - - 7 Water up to - - - - - 100 This dye imparts a light reddish-brown tone to live hair in the cold or at a temperature below 40 C. B-AZINE DYESTUFFS EXAMPLE 7 A dye is prepared by solubilising the following anion-cation complex: g. Anion: Dyestuff known under the proprietary name "Induline B (water soluble)" (one brand of No. 861 of Colour Index) - - - - 2 Cation: Product known under the name "Lissolamine A" (octadecylpyridi nium bromide) - - 1.3 with "Cemulsol 132" - - - - 4.75 Lactic acid - - - - - 2.5 Water up to - - - - - 100 A bluish grey is obtained on natural white hair. EXAMPLE 8 A dye is prepared by solubilising the following anion-cation complex: g. Anion: Dyestuff known under the proprietary name " Induline RAL" (another brand of No. 861 of Colour Index)- 2 Cation: Ester of fatty acid from copra and diethylethan olamine previously con densed with 4.5 mole

cules of ethylene oxide 2.65 with " Cemulsol 132" - - - - 4.25 Lactic acid - - - - - 2.5 Water up to - - - - - 100 An azure blue lustre is obtained on blond and brown hair. EXAMPLE 9 A dye is prepared by solubilising the following anion-cation complex: g. Anion: Dyestuff known under the proprietary name Nigrosine L F M (water-soluble)" (one brand of the water soluble Nigrosines men tioned under No. 865 of Colour Index) - - 2 Cation: Product known under name " Lissolamine A" (octadecylpyridi nium bromide) - - 1.2 with "Cemulsol 132" - - - - 3.25 Lactic acid - - - - - 2.50 Water up to - - - - - 100 A bluish-grey tint is obtained on white hair. CDYESTUFFS DERIVED FROM XANTHENE EXAMPLE 10 A dye is prepared by solubilising the following anion-cation complex: g. Anion: Product known under the naem "Rouge Kiton Brilliant B" - - - 2 Cation: Product known under the name "Lissolamine A" - - - - - 0.4 "Cemulsol 132" - - - - 0.5 Lactic acid - - - - - 2.5 Water up to - - - - - 100 A pinkish-auburn tint is obtained on all hair. A thickening agent of known type may be incorporated in a dye according to the invention, notably in order to facilitate the application thereof to live hair, but this thickening agent must be so

chosen as not to modify the ionisation equilibrium of this dye. The said thickening agent may be either gelatin or a product of condensation of ethylene oxide with an aliphatic alcohol. In the latter case, the condensed ethylene oxide may act as a solubilising agent for the equimolecular anion-cation complex, that is to say, it may render unnecessary the use of a non-ionic product such as "Cemulsol 132" indicated in the foregoing examples. The dye then takes the form of a jelly, a paste or a cream. EXAMPLE 11 A cream dye is prepared by solubilising the following anion-cation complex: g. Anion: Product known under the name "Noir diazol BH" - - - - 2 Cation: Product knotvn under the name "Lissolamine A" (octadecylpyridi nium bxomide) - - 0.7 with Hydroxyethylene cetyl alcohol - 15 Lactic acid - - - - - 5 Distilled water up to - - - 100 A cream is obtained in which the hydroxyethylene cetyl alcohol acts both as solubilising agent for the anion-cation complex and as a thickening agent in the cream obtained. This cream gives a somewhat distinguished grey-black on live hair at a temperature below 30 C. EXAMPLE 12 A dye is prepared in the form of a gel by solubilising the following anioncation complex: g. Anion: Product known under the name " Violet chlor antine 5 BLL" - - 2 Cation: Product known under the Registered Trade Mark " Lissolamine A" (octadecylpyridi nium bromide) - - 0.25 with "Cemulsol 132" - - - - 5.9 Lactic acid - - - - - 2.5 Gelatin 8

Water up to - - - - - 100 The dye takes the form of a jelly and imparts a rather distinguished violet-lilac tint to hair at a temperature below 30 C. It will be understood that the solubilisation of the anioncation dye complex may be effected either by adding a non-ionic solubilising agent or by using a product resulting from the condensation of ethylene oxide on the cation neutralising the anionic dyestuff, or again by a combination of these two methods. What we claim is: - 1. A process for the production of a hairdye suitable for direct dyeing of hair at room temperature which comprises combining equimolecular amounts of an anionic dyestuff of the type reran described and a cation-active compound containing at least 6 carbon atoms whereby a dyeing, anion-cation complex is obtained, and water-solubilising said complex by means of a quantity of a solubilising agent which is just sufficient for the purpose and which leaves the molecular anion-cation balance substantially unchanged. 2. A process according to Claim 1 wherein said anionic dyestuff is that obtained by coupling the diazonium salt of an aromatic amine of the benzene series with 2-phenylamino-8- naphthol-6-sulphonic acid. 3. A process according to Claim 1 wherein said solubilising agent is a water-miscible alcohol. 4. A process according to Claim 1 wherein said solubilising agent is a water-miscible condensauion product of a lower alkylene oxide with an alcohol or a phenol. 5. A process according to Claim 1 wherein said solubilising agent is first reacted with the cation-active compound to form a cationactive derivative which forms with the anionic dyestuff a water-soluble anion-cation complex. 6. A process according to Claim 1 wherein said cation-active compound is a nitrogeneous base with a lipophilic chain of 12 to 14 carbon atoms which is bound to the hydrophilic residue of an amine or a quaternary ammonium base. 7. A process as claimed in any one of the preceding claims, wherein the dyeing solution is acidified with an organic acid (for example, lactic acid) to bring the pH to a value below 7 (for example 4.5 to 5.5). 8. A process for the production of a hair dye substantially as described with reference to any one of the specific examples herein. 9. A hair dye when prepared by the process claimed in any one of the preceding

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* GB785726 (A)

Description: GB785726 (A) ? 1957-11-06

Improvements in or relating to foundry core materials




PATENT SPECIFICATION Inventor: ERIC PARKES Date of filing Complete Specification May 22, 1956. Application Date June 15, 1955. 785,726 No 17262/55. Complete Specification Published Nov 6, 1957. Index at Acceptance: -Class 83 ( 1), F 6 BX. International Classification: -B 22 c. COMPLETE SPECIFICATION Improvements in or relating to Foundry Core Materials We, THE FORDATH ENGINEERING COMPANY LIMITED, a British company of Hamblet Works, Albion Road, West Bromwich, in the County of Stafford, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: - This invention relates to the manufacture of cores for use in the foundry industry and is particularly applicable in connection with

cores which are of a large size, or which have substantial projections and/or overhang. It has heretofore been the practice when making such cores to use a high green strength sand but this gives rise to difficulties in filling the core box as such a sand contains a high percentage of clay and when the sand and oil binder are mixed together they form a moist, dough like material which is difficult to ram into the core box Furthermore, although a high green strength sand is used, it is still necessary to provide reinforcing and supporting members. Accordingly, it has become the practice recently to use for the formation of such cores a special core binder which incorporates an accelerator which assists in polymerisation so that the core will set in its box at room temperatures so that the core can be removed from the box without deformation. The object of the present invention is to provide an improved core binder incorporating an accelerator as described above. According to the present invention we provide a core forming material comprising 1 5 to 2.5 per cent by weight of the whole of a suitable oil binder 0 02 to 0 20 per cent by weight of the whole of calcium hypochlorite, the remainder of the mix comprising a cold dry sand of a suitable grain size. Due to the fact that calcium hypochlorite is slightly deliquescent it has been found advisable to mix the calcium hypochlorite with a proportion of any fine chemically inert powder, such as silica flour, so as to ensure that the calcium hypochlorite is present in the form of a free flowing powder This proportion may range from 25 to 75 per cent by weight of the quantity of calcium hypochlorite present. In carrying out our invention the sand, whose grain size will be chosen in accordance with the finish which it is desired to provide on the casting, is placed in a suitable mixing machine and the calcium hypochlorite, together with the inert powder, is added The proportion of the mixture of calcium hypochlorite and inert powder used is between 0 02 and 0.20 per cent by wight of the total mix and to these materials is added the oil binder which constitutes 1 5 to 2 5 per cent by weight of the total mix The quantity of oil binder used will depend firstly upon the grain size of the sand and secondly upon the setting time required when the mix has been placed in the core box. Similarly the exact quantity of calcium hypochlorite used will be directly proportional to the quantity of the oil binder used and to the rate of hardening desired. These constituents are mixed together in the mixing vessel for a period of some five minutes and the resultant mix is a free flowing sand which can readily be rammed into the core box. The use of calcium hypochlorite as an accelerator has certain

advantages over accelerators which have previously been proposed in that it enables a greater measure of control to be exerted over the hardening process When calcium hypochlorite is mixed with the sand and the drying oil, chlorine is liberated which causes oxidation of the drying oil, thereby bringing about an increase in the rate of hardening of the sand This increase is, however, less -rapid than that which is brought about by the liberation of oxygen from, for example, sodium perborate. The addition of an inert powder such as silica flour not only overcomes the disadvantage-of the deliquescence of the calcium hypo785,726 chlorite, but also renders the accuracy of the additions of the calcium hypochlorite accelerator less critical and it is found that by using an equal mixture of silica flour and calcium hypochlorite with the total mix in the proportions of 0 02 per cent to 0 20 per cent by weight of the total mix that the hardening time can be varied from a few minutes to two to three hours. If an inert powder were not added to the calcium hypochlorite, then the calcium hypochlorite tends to form into hard lumps and the formation of such lumps should be avoided since, should they happen to occur on the sur1 S face of the core, the resulting casting will be spoilt. When the constituents have been mixed and rammed into the core box, polymerisation will have commenced and, as soon as the requisite hardening time has occurred, the box can readily be stripped from the core which will be found to be extremely firm The core can then readily be transported to the oven where it will be subjected to the normal baking operation at a temperature between 2200 and 2500 C and for a length of time which will depend upon the size of the core. The oil binder which is used is of a type commonly used in core making work and may conveniently comprise a blend of raw tung oil or oiticica oil, air blown linseed oil, and cobalt and lead naphthenates, the two naphthenates forming approximately 3 per cent by weight of the oil binder and the tung or oiticica oil forming 10 to 60 per cent by weight of the oil binder Preferably 30 per cent of tung oil is used and the quantity of tung oil used will depend to some extent upon the speed with which it is desired the core should harden. If desired a suitable mineral base polymerising oil may be added to the oil binder. It will be appreciated that the quantity of oil binder and accelerator used must not be such that the mix will set too rapidly else this might result in the mix setting before the operator has been able to fill the core box.

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* GB785727 (A)

Description: GB785727 (A) ? 1957-11-06

Improvements in or relating to the preparation of 1-alkynes




COMPLETE SPECIFICATION Improvements in or relating to the preparation of l-Alkynes We, TkE BRITISH OXYGEN COMPANY LIMITED, a British Company, of Bridgewater House, Cleveland Row, St. James's, London- S.W.1) do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to the preparation cf l-alkynes by the dehydrohalogenation of the corresponding halogenated hydrocarbons, and is an improvement in or modification of the invention of our British Letters Patent No. 709,126. Processes are known for the preparation of l-alkynes by the dehydrohalogenation of dihaloalkanes or of monohaloalkenes. Thus, for example, propyne has been preparecP from

l: 2 dibromopropane using potassium hydroxide or sodium ethoxide solutions in ethanol as dehydrohalogenation agents. The process may be carried out under increased pressure. For example, it has been stated that 1:2-dichloropropane may be reacted with potassium hydroxide in methanol at 175 C and 5 atmg. to yield 70-80% propyne; but it is probable that the reaction under these conditions is hazardous, owing to the possibility of initiating a violent exothermic decomposition of propyne. It has also been proposed to prepare alkynes having at least 4 carbon atoms in the molecule by the dehydrohalogenation of the corresponding dihaloalkanes or monohaloalkenes by heating them with an alkali metal alkoxide of an alcohol boiling above 100 C.) in solution in a water-free alcohol boiling above lOO C., and more sarticularly by heating with a 2-ethoxyethoxide in 2-ethoxyethanol (ethylene glycol monoethylether). It is empehasised, however, that in order to obtain good yields of alkynes, the alkoxide solution employed must be anhydrous. The anhydrous alkali metal alkoxide is obtained either by dissolving the alkali metal itself in the alcohol, or by dissolving the alkali metal hydroxide and removing the water formed by azeotropic dis tillation, for example with benzene. In our British Patent Specification No. 709,126 we have described a process for preparing l-alkynes which comprises continuously feeding a 1: 2-dihaloalkane or a 1- or 2-monohaloaLkene into a boiling solution of an aLkali metal alkoxide of an alcohol boiling above 100 C. in an alcohol boiling above 100 C. and substantially above the boiling point of the 1- alkyne at a rate such that the temperature of the solution is not substantially lowered during the addition and separating the alkyne from the vapours released from the solution. This has the advantage that dehydrohalogenation can be effected satisfactorily even in the pre sence of moisture. When the alkoxide is prepared by reacting an alkali metal hydroxide with the alcohol boiling above 100 C., water is formed according to the equation: R.OH+M.OHeR.OM+H20 and this water is subsequently evolved with the (alkyne-containing) vapours released from the solution. It is unnecessary to remove the water (for example) by azeotropic distillation with a third solvent such as benzene) prior to the reaction with the dihaloalkane. The method of Specification No. 709,126 allows reasonably high yields of alkynes to be obtained under conditions where the alkali metal hydroxide used to form the alkoxide exceeds the amount needed to saturate the alcohol used at the temperature of reaction.

Under such conditions, however, the reacting mixture becomes progressively more difficult to handle as the reaction proceeds, since a thick slurry of precipitated alkali metal halide in a saturated solution of hydroxide results, and this impedes the dissolution of alkali metal hydroxide to replace that which reacts. The final slurry of undissolved alkali metal hydroxide and virtually insoluble alkali metal halide leads to difficulties in emptying and recharging the reactor and in recovery of solvent. If, on the other hand, the initial quantity of alkali metal hydroxide is substantially reduced, it has been observed that it is difficult to carry the dehydrohalogenation to completion. In particular, the dehydrochlorination of a dioblaro- alkane proceeds very rapidly even at comparatively low concentrations of alkali metal hydroxide, but largely only as far as the monochioroalkene and the dehydrochiorination of the monochloroalkenes proceeds very slo.-.ly under such conditions. It has been proposed in our co-pending Application No. 32457/54 (Serial No. 777,141) to operate in such a manner that the solution is at all times at least 5u,o saturated with the alkali metal alkoxide whilst the proportion of alkali metal halide present at any time is never in excess of the amount chemically equivalent to that quantity cf alkali metal alkoxide which would 50% saturate the alcohol. In this way, the reacting mixture remains substantially fluid at all times, whilst the dehydrohalogenation can nevertheless be carried out to completion at a satisfactory production rate. In our co-pending Anplication No 2o91/55, (Serial No. 783,629Y similar objectives of operating with a substantially fluid reacting mixture capable of reasonably good filtration, whilst carrying out the dehydrohalogenation to completion at a satisfactory production rate, are attained by feeding the monohaloalkenes into a second, separate, heated solution of alkali metal alkoxide, the second solution being at least 50% saturated therewith. This procedure can be so operated as to effect fuller utilisation of the alkali metal alkoxide. It is an object of the present invention to provide a further modification of the process of British Patent No. 7u9,126 in which the objects achieved in our co-pending Application Nos. 32457/54 (Serial No. 777,141) and 2891/55 are achieved in different ways. It is a further object of the present invention to reduce the amount of alcohol needed to carry out the process and at the same time to reduce the amount of alcohol which cannot economically be made available for re-use, owing to its physical attachment to the alkali metal halide present when the contents of the reaction vessel are

filtered. According to the present invention, a process for preparing 1-alkynes comprises continuously feeding a 1: 2-dihaloalftane or a 1or 2- monohaloalkene into a stirred mixture heated to a temperature above 100 C. containing an alkali metal hydroxide or alkoxide of an alcohol boiling above 100 C., an inert liquid diluent boiling above 100 C. and substantially above the boiling point of the 1alkyne, and a solution of the alkali metal hydroxide or alkoxide in an alcohol balling above 100 C., and substantially above tbe boiling point of the 1-alkyne the amount of diluent present being not more than nine times the total weight of the alcohol present and of the alcohol equivalent to the alkoxide present, at a rate such that the temperature of the solution is not substantially lowered during the addition and in an amount such that the alcohol present is at all times at least 5G% saturated with the alkali metal alkoxide, and separating the alkyne from the vapours released from the solution. Particularly suitable alcohols for cperating the process of this invention include ethox,- ethanol, CH3CH2.O.CH2.CH2OH, butoxy ethanol, CH, . CH2 CH CW 0. CII CH,OH, ethoxyethoxyethanol, CH3CH2G.CH CH sO CH2CH2OEI, and monoethyl ethers of the higher polyoxyethylene glycols CH3.CH2(O. CH2.CH2)n.OH, but the invention is not limited to the use of these particular alcohols. The temperature of operation may be varied between a lower limit of about 100 C. and an upper limit v.4'.ich will depend on the stability of the particular alcohol used when saturated with alkali metal hydroxide or alkoxide. In general, temperatures in the region of 150-170 C. are preferred, but the invention is not limited to this temperature range. The process may be operated with any nonaqueous liquid diluent which is stable under the temperature conditions used and in the presence of the constituents of the reaction mixture (particularly the high concentration of alkali metal hydroxide or alkoxide) but it is preferred to use a hydrocarbon or hydrocarbon mixture boiling at a temperature above the preferred operating range of 150-170 C. The invention is not, however, limited to the use of such hydroca-bons. In the preparation of propyne (b.p.-23 C.) or l-butyne (b.p. 8.5 C.), substantial separation of the alkyne from the residual vapours can be

effected by condensation of the latter, using a condenser cooled to normal ambient temperature, but in the case of propyne prepared from 1: 2dichloropropane, refrigeration to a small extent may be desirable, since the most volatile chloroprosylene formed (2chioropropylene) boils at 23 C. The process of this invention can to some extent be used in conjunction with those described in our co-pending Application Nos. 32457/54 (Serial No. 777,141) and 2891/55, (Serial No. 783,629) or independenfly of them. If used in conjunction, the process is operated with a dihaloalkane which nzay be fed into a vessel containing the reaction mixture, and the condensate. obtained during the separation of the alkyne (if necessary after separation of the aqueous layer as explained below), returned to the same reaction vessel until such time as the residual alkali metal alkoxide is such as would 50 ' saturate the alcohol present at the temperature of reaction. Thereafter, the diUloa!kane feed cpn 'oe contijiued but the condensed vapours other than alkyne and water are fed to a second vessel containing alkali metal hydroxide or alkoxide, inert liquid and a heated solution of the alkali metal alkoxide in the alcohol boiiing above 100 C., the solution being at least 50% saturated. By operating according to the present invention either alone or in conjunction with those of our co-pending Application Nos. 32457/54 (Serial No. 777,141) and 2891/55 (Serial No. 783,629), it is possible to feed dihaloalkane to the solution of the alkali metal hydroxide or alkoxide until a very large proportion of the hydroxide or alkoxide has been converted into the corresponding alkali metal halide. It has been observed that the initial slurry of alkali metal hydroxide or alkoxide, inert liquid, and alcohol solution is readily stirred and also that the slurry of the alkali metal halide in the alcohol and inert liquid at the end of the reaction is particularly readily filtered and that the filter cake is convenient to handle. Moreover, since the amount of alcohol present in comparison with the method of British Patent No. 709,126 has been reduced and replaced by inert liquid, utilisation of the alkali metal hydroxide charged is more nearly complete since there is present throughout the reaction sufficient alkali metal alkoxide to 50% saturate the alcohol. Whereas it has been observed that, if monohaloalkene is fed to a heated solution of alkali metal alkoxide in which the amount is less than would 50% saturate the alcohol, the rate of production of alkyne becomes considerably reduced, by using the process of the present invention, it is possible to achieve continuously satisfactory rates of production of alkyne.

It has further been observed that the amount of alcohol or alkoxide retained on the alkali metal halide, which results from filtration of the reaction product, is considerably less than would have been the case if no dilution of the alcohol by inert liquid had been mace. Since the preferred alcohols are relatively expensive materials, the process of the present invention enables the loss of solvent which results from physical admix ture with the filter cake of metal halide and unreacted metal hydroxide to be considerably reduced. In a further elaboration of the method of the present invention, the solution of alkali metal alkoxide or hydroxide together with free alkali metal hydroxide and inert liquid diluent which has been reacted with monohaloalkene until the amount of alkali metal alkoxide has been reduced to that which would about 50% saturate the alcohol, can be subsequently reacted with dihaloalkane according to the method of the present invention, the monol1aloalkene formed being fed to another solution more concentrated in and at least 50% saturated with the alkali metal alkoxide stirred uiith a similar proportion of inert liquid diluent and free alkali metal hydroxide. By operating in this way, utilisation of substantially the whole of the alkali metal hydroxide or alkoxide can be achieved in a sequence of operations. The invention is illustrated by the following examples: EXAMPLE 1. A reaction vessel consisting of a closed steel pot provided with stirring means and with suitable connections for the addition of 1 :2diclaloro-propane or chioropmpylenes, for the addition of solvent and caustic soda, for talking off a slurry of sodium chloride and sodium hydroxide in the solvent, for removing gaseous reaction products and for retuning material condensed from the reaction products, was charged with 0.67 kg. of ethoxyethoxyethanol, 2.01 kg. of a commercial gas oil (boiling range 1773u0 C.) and 0.56 kg. of caustic soda. The vessel was then warmed to 16 > 170 C. with stirring-an operation which could be performed quite easily. 0.153 kg. of chloropropylenes was then fed to the vessel, followed by 0.678 kg. of 1:2Zichloropropane, both being fed at a controlled rate. There was produced 0.199 kg. of propyne (64% yield based on dichioropropane); the allene yield was 13%. The material left in the reaction vessel was filtered and its caustic soda content determined. From this it was calculated that the amount of caustic soda used in the reaction was 2.8 g. per g. of propyne. At the same time the ethoxyethoxyethanol retained on the filter calre was 40 g., equivalent

to (t.20 g. per g. of propyne. EXAMPLE 2. The reaction vessel used in Example 1 was charged with 0.67 kg. of ethoxyethoxyethoxyethanol, 2.01 kg. of commercial gas oil (boiling range 1773u05 C.) and 0.56 kg of caus tic soda, and then heated to 160-170 C. 791 g. of 1: 2-dichioropropane were fed to the vessel at a controlled rate. 154 g. of prQt-yfle were produced, corresponding to a yield of 63%, after allowing for the chioropropylenes formed. The caustic soda used was equivalent to 3.9 g. per g. of propyne, while the ethoxyethoxyethoxyethancl content of the filter cake remaining when the residual contents of the reaction vessel were easily filtered was 41 g. Or 0.27 g. per g. of propyne. COMPARATIVE EXPERIMENT USING THE CON DITIONS OF BRITISH PATENT NO. 709,126 In order to illustrate the fuller utilisation of the caustic soda and the reduction in the amount d alcohol retained in the filter cake obtained by the method of the present inven tion, a second experiment was carried out in the vessel used in Example 1 under the conditions described in British Patent No. 709,126. In this case, the vessel was charged with 0.80 kg. of caustic soda and 2.68 kg. of ethoxyethoxyethanol and heated to 160--170" C. At this temperature, 0.168 kg. of chloropropylenes was fed to the reaction vessel, and when this had reacted, 0.66 kg. of 1:2dichlcropropane was fed, the amount of chioropropylenes formed being allowed to build up in a storage vessel, > so as to limit the amount of chioropropylenes recycled to the reaction vessel. At the end of the reaction 168 g. of propyne, 49 g. of allene and 58 g. of chloropropylenes had been produced. After allowing for the chloropropylenes fed and prow ducked, the yield of propyne and allene based on diclaloropropane was 74%. The caustic soda reacted corresponded to a usage of 4.13 g. per g. of propyne, whilst 147 g. of the ethoxyethoxyethanol was retained in the filter cake, equivalent to 0.88 g. ner g. of propyne produced. What we claim is: - 1. Process for preparing a l-alkyne which comprises continuously feeding a 1: 2-dihaloalkane or a 1- or 2-monohaloalkene into a stirred mixture heated to a temperature above 1000 C. and containing an alkali metal hydroxide or alkoxide of an alcohol boiling above 1003 C., an inert liquid diluent boiling above 100" C. and substantially above the boiling point of the 1-alkyne, and a solution of the alkali metal alkoxide of an alcohol boiling above 100" C. in an alcohol

boiling above 100" C., and substantially above the boiling point of the 1 alkyne the amount of diluent present being not more than nine times the total weight of the alcohol present and of the alcohol equivalent to the alkoxide present, at a rate such that the temperature of the solution is not substantially lowered during the addition and in an amount such that the alcohol present is at all times at least 50% saturated with the alkali metal alkoxide, and separating the alkyne from the vapours released from the reaction mixture. 2. Process according to Claim 1 wherein the alkyne is separated from the vapours released from the reaction mixture by passing the vapours through a condenser maintained at a temperature above the boiling point of the alkyne but below the boiling points of the other constituents of the vapours, whereby said other constituents are condensed. Process according to Claim 2 wherein the condensate after substantial removal of water contained therein is returned to the reaction mixture. 4. Process according to Claim 2 wherein the starting material is a 1.2-dihaloalkane and wherein the condensate after substantial removal of water contained therein is return.. to the reaction mixture until the residual alkali metal alkoxide therein is such as would 5Qot saturate the alcohol present therein at the temperature of reaction and is thereafter fed to a second stirred heated mixture separate from the original reaction mixture, containing an alkali metal hydroxide or alkoxide of an alcohol boiling above 100" C. an inert liquid diluent boiling above 100" C. and substantially above the boiling point of the 1alkyne and a solution of the alkali metal alkoxide in an alcohol boiling above 100" C. and substantially above the boiling point of the 1-alkyne the amount of diluent present being not more than nine times the total weight of the alcohol present and of the alcohol equivalent to the alkoxide present at a rate such that the temperature of the reaction mixture is not substantially lowered during the addition and in an amount such that the alcohol present is at all times at least 50O/ saturated with the alkali metal alkoxide, whilst continuing to feed the 1.2-dihaloalkane to the original reaction mixture. 5. Process according to any of the rreced- ing claims, wherein the alcohol boiling above 100" C. is ethoxyethanol, butoxyethancl!. ethoxvethoxyethanol or monoethvl ethers of the hither polyoxyethylene glycols. 6. Process according to any of the preceding claims wherein the temperature of the reaction mixture or of each reaction mixture is 150170 C.

7. Process according to anv of the preceding claims wherein the inert liauid diluent is a hydrocarbon or hydrocarbon mixture. 8. The modification of or improvement in the process for preparing a l-alkvne described and claimed in British Patent No. 709,126, substantially as hereinbefore described wito reference to Example 1 or Example 2. 9. 1-alkynes when prepared by the process of any of Claims 1 to 8. PROVISIONAL SPECIFICATION Improvements in or relating to the preparation of 1-Alkynes We, THE BRITISH OXYGEN COMPANY LIMITED, a British Company, of Bridgewater House, Cleveland Row, St. James's London, S.W.1, do hereby declare this invention to be described in the following statement: This invention relates to the preparation of l-alkynes by the dehydrohalogenation of the corresponding halogenated hydrocarbons, and is an improvement in or modification of the invention of our British Letters Patent No. 709,126 Processes are known for the preparation of 1-alkynes by the dehydrohalogenation of dihalo-alkanes or of monohaloalkenes. Thus, for example, propyne has been prepared from 1: 2-dibromopropane using potassium

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