* GB785979 (A)

Description: GB785979 (A) ? 1957-11-06

Improvements in or relating to the production of lithium carbonate

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PATENT SPECIFICATION Date of filing Complete Specification: June 24, 1955. Application Date: April 7, 1954 No 10220 /54. Complete Specification Published: Nov 6, 1957. Index at Acceptance -Class 1 ( 3), A 1 (D 8: 044 D 8: N 44). International Classification:-C Old. COMPLETE SPECIFICATION. Improvements in or relating to the Production of Lithium Carbonate. We, ENGLISH CLAYS LOVERING POCHIN & COMPANY LIMITED, a British Company, of 14 High Cross Street, St Austell, Cornwall, and IAN HENRY WARREN, a British Subject, of the Company's address, 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 a process for the production of lithium carbonate, and is concerned with a process for the production of lithium carbonate by precipitation from a saturated aqueous solution containing potassium and lithium sulphates. It is well known that lithium salts can be obtained from lithium silicate minerals or other lithium-containing minerals by a treatment involving the use of aqueous potassium sulphate A saturated aqueous solution containing a mixture of the sulphates of lithium and

potassium is obtained by this process One known method for extracting a lithium salt from this solution is to precipitate lithium carbonate by the addition of sodium or potassium carbonate. However, owing to the high solubility of the lithium carbonate in the saturated solution the first precipitation is incomplete and the lithium carbonate can only be extracted by a lengthy and costly succession of stages Furthermore, owing to the limited solubility of potassium sulphate in water, it has not been found possible to precipitate the dissolved lithium carbonate without contaminating the precipitated lithium with potassium sulphate Finally, it has also been found that a prior separation of the lithium sulphate from the potassium sulphate cannot be effected by crystallisation, since crystals consisting of a double sulphate of lithium and potassium are obtained from the saturated solution. According to the present invention, there is provided a process for the production of lithium carbonate by precipitation from a saturated aqueous solution containing potassium and lithium sulphates wherein potassium hydroxide is added to said solution in a molar proportion substantially equivalent to the molar proportion of lithium sulphate present, potassium sulphate and lithium hydroxide being respectively precipitated and dissolved, and wherein the precipitated potassium sulphate is removed, gaseous carbon dioxide being then added to said solution whereupon the lithium ions present in the solution are precipitated as lithium carbonate which is filtered off. The present invention is illustrated by the following example:14 gins of potassium hydroxide were added to a saturated aqueous solution containing a mixture of 13 7 gms of lithium sulphate and 12 gms of potassium sulphate and, on standing the solution, potassium sulphate was found to have precipitated and was filtered off Finally, carbon dioxide was bubbled into the mother liquor from this filtration and the lithium carbonate which precipitated out was separated from the solution by a further filtration and was washed with water. The potassium sulphate in solution on precipitation of the lithium carbonate was found to be approximately one half the amount that was formed by the addition to a pure solution containing lithium sulphate of an equal amount of potassium carbonate. It is believed that the precipitation of potassium sulphate by the addition of potas785,979 785,979 sium hydroxide was due to the common ion effect of the added potassium ions when potassium hydroxide was added to the saturated aqueous solution. The two stages of the process just described were carried out as follows:The saturated aqueous solution containing potassium sulphate and lithium sulphate was poured into a large vat and potassium hydroxide was then added with stirring at room temperature After being

allowed to stand for a few hours at room temperature, the suspension thus obtained was fed to a filtration apparatus such as a filter press, in which the precipitated potassium sulphate was removed Carbon dioxide was then bubbled through the mother liquid, preferably in a pressure vessel, and the lithium carbonate precipitate which formed was filtered and washed. The vats were made of any material capable of resisting the action of strong alkalis at room temperature, e g of stainless steel and the minerals used to prepare the saturated aqueous sulphate solution in the example were silicate minerals of a micaceous nature of the kind occurring in the "china clay" area of Cornwall (the minerals being known as "zinnwaldite"). Lithium compounds have a large number of industrial applications They are used in greases due to their high resistance to heat, in air-conditioning media, in shockresisting glass, and in bleaching agents.

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* GB785980 (A)

Description: GB785980 (A) ? 1957-11-06

Improvements relating to water-soluble polymerizable polyesters

Description of GB785980 (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 785,980 Date of Application and filing Complete Specification: Nov 16, 1954. No 33181/54. Application made in United States of America on Dec 28, 1953. Complete Specification Published: Nov 6, 1957. Index at acceptance:-Classes 2 ( 5), R 3 C( 2: 4:16:17), R 3 D( 2 B: 3:4:5:6:11:12:13), R 3 T 2; and 2 ( 6), P 9 A, P 9 D( 1)13: 1 B 3:3), P 9 PIE( 1: 2: 4: 5), P 9 P 2 (A 1: A 5: C: X), P 9 P 4 C. International Classification:-CO 8 f, g. COMPLETE SPECIFICATION Improvements' relating to Water-Soluble Polymerizable Polyesters We, GENERAL ELECTRIC COMPANY, a Corporation of the State of New York, United States of America, having its office at Schenectady 5, State of New York, United States of America, do here-by 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 water-soluble polyesiters and to water-insoluble polymers derived therefrom upon curing. It is known that water-soluble polyesters can be prepared from polyethylene glycols and unsaturated dibasic acids Polymers of these polyesters, however, have the disadvantage of curing to a tacky surface rather than Ito a desirable non-tacky surface Additionally, the polyethylene glycols have the inherent disadvantage of possessing only two hydroxyl groups, as a result of which the polyesters derivable from these polyethylene glycols are, except for cross-linking at unsaturated double bonds, linear in nature, land their cured masses are rubber-like, rather than tough, horn-like masses Since the horn-like masses are to be desired for many end uses, the products derived from polyethylene glycols and unsaturated dibasic acids are not entirely satisfactory for practical commercial purposes. It has now been found in accordance with the invention that water-soluble polyesters which are capable of curing to infusible, nontacky, substantially water-insoluble masses, which masses are very tough and horn-like, may be prepared by reacting an unsaturated aliphatic dicarboxylic acid or anhydride, a dicarboxylic acid free of ethylenic unsaturation, and a randox polyhydric alcohol The term " randox polyhydric alcohol " is used herein to define polyhydric alcohols which are obtained as a result of condensing a base polyhydric alcohol containing at least three hydroxyl groups, such as pentaerythritol, inositol, sorbitol, enneaheptafite and erythritol, t

PW 1 c 2 3 5, 6 d l with at least one molar equivalent of ethylene oxide (i e the number of mols of ethylene oxide employed lin the condensation reaction is at least equal to the number of mols of polyhydric alcohol present). The randox polyhydric alcohols used in the process of this invention are specifically designated by the following nomenclature: First, there is placed the name of the basic polyol from which the ethylene oxide derivative is obtained; this is followed by the word "randox" in order to signify the ethylene oxide modification of the base polyol and thereafter an arabic number i's attached The arabic number represents the average number of -CH 2 C 12-O groups which are contained in each mol of randox polyhydric alcohol For example, using the above nomenclature, the randox polyhydric alcohol produced by condensing 8 mols of ethylene oxide with one mol of sorbitol would be designated as: Sorbitol randox 8 The term "randox " is not intended to refer to the pattern of distribution of -CH,-CH 2-O groups in the polyhydric alcohol molecule, but to refer only to the presence and number of such groups therein. Generally, ithe reaction of ethylene oxide with a polyol may take place under substantially anhydrous conditions However, it is frequently advantageous to cause the reaction of the polyhydric alcohol to take place with the ethylene oxide in the presence of water When the randox alcohols are produced in the presence of water, they are mixed with various polyethylene glycols It is not necessary for the purpose of this invention' to isolate the randox polyhydric alcohol from the polyethylene glycols as in particular cases the mixtures may be used to advantage without isolation of the various componentes When mixtures of polyethylene glycols and randox polyhydtic alcohols are employed, such a mixture may be designated by placing the word " hydra " between the name of the bastic polyhydric alcohol 4 ' and the word " randox " After the word " hydra " there is indicated in arabic numerals the per cent water present in the basic polyhydric alcohol-water mix prior 'to reaction with ethylene oxide However, when the word " hydra " appears, the final arabic number following the word "randox" refers to the number of mols of ethylene oxide reacted with one mol of the basic polyhydric alcohol-water mixture For example, using the above system of nomenclature, the designation: Sorloitol hydra 15 randox 8, refers to the product formed by reacting 8 gram mols of ethylene oxide with 182 grams ( 182 being the moleicular weight of sorbitol) of sorbitol-water mixture, said sorbitol-water mixture being 85 % sorbitol by weight and 15 % water by weight. In situations where polyhydric alcohol and water are reacted with ethylene oxide, and in order to further distinguish the randox

polyhydric alcohols which form the basis of the polyesters comprising this present invention, the " Diol Ratio " may be used as la means of identification By the term " Diol Ratio " the ratio of mols of diol to mols of randox polyhydric alcohols is specified. This Diol Ratio may be calculated as follows: Diol Ratio = where: (A x B)-C(B + 44 N) 18 ( 1-A) A = per cent water in polyol before reaction with ethylene oxide divided by 100. B = grams of basic polyhydric alcohol considered. C = per:cent water in reaction product divided by 100. N = randox number=number of mols of ethylene oxide reacted with B. In the case of sorbitol hydra 15 randox 8 where 0 5 % water remains in the reaction product, the diol ratio of 1 61 is obtained as follows: (.150) x ( 182) - 005 ( 182 + 8 x 44) Diol Ratio = 18 x 85 = 1 61 Randox polyols found eminently suitable in the process of this invention possess the unique advantage of having a plurality of ether groups attached to -CH 2-GCH groups and at the same time making it possible for So the existence of more than two hydroxyl groups More than two hydroxyl groups in the presence of a plurality of oxygen atoms each attached to a -CH 2-CH 2 groups is especially important in connection with the production of initially water-soluble polyester resins which cure to produce masses that are hard, tough, essentially water-insoluble and non-tacky Accordingly, randox esters containing both polymerizing and non-polymerizing type dibasi'c acids are distinctly different from the corresponding polyethylene glycol esters. The polyethylene glycols produce watersoluble resins when esterified with polymerizing 'type dibasic acids such as maleic and fumaric However, when a part of the polymnerizing dibasic acid is replaced with a nonpolymerizing acid the water-insoluble cured products remain tacky. Unexpectedly, it has now been found that non-polymerizing type dibasic acids such as phthalic acid, may be used together with polymerizing type dibasic acids without resulting in tacky, cured products but producing products possessing improved hardness and resilience Thus, it was entirely unexpected that randox polyhydric alcohols when esterified with mixtures of both non-polymerizing and polymerizing dibasic acids would cure to non-tacky masses since this was entirely opposite from what would have been predicted to occur from past experiences with similar esterification products of polyethylene glycols. The water-soluble polyesters produced by the esterification of randox polyhydric alcohols with mixtures of unsaturated dibasic acids and 85 non-polymerizing dibasic acids in accordance with the process of this

inven N wihen cured by the action of heat or free radical catalysts find desirable utility in many industrial applications such as modifying the properties of 90 webs and textiles, for altering the characteristics of paper, and for use in printing systems for paper, textiles anll plastics In each of these applications the water-soluble polyesters have the distinct advantage of being 95 transferable to the point of use in a system where the main carrying fluid is water, and after deposition of the resin with suitable modifiers into or onto items intended for modification, the proper combination of 100 catalysts or heat and catalysts will cause the resin to cure and become substantially waterinsoluble In an alternative manner, the catalysts may be previously introduced into the water carrying system of water-soluble poly 105 ester. The randox polyhydric alcohols found eminently suitable for the process of this inve D tion lie within the range of randox 3 to randox 30 A particularly advantageous group 110 of randox polyhydric alcohols ranges between randox 8 and randox 20 As the basic polyol to be employed, sorbitol is preferred since it presents the advantage of producing randox derivatives wherein, a portion of the randox 115 contains six hydroxyl groups per mol In this manner, the average hydroxyl functionality of sorbitol randox 8 is 6, snd the average 785,980 directly to the water solution of these polyesters Such a water system presents the major advantage of being transportable as a water system to the point of use where the water is partly or completely removed by suitable means, one means being by simple evaporation into the air at room temperature, and thereafter free radical catalysis causing the curing process to take place by the application of heat. The free radical catalysts which may be employed in obtaining cured products of this invention are the conventional free radical catalysts generally used Suitable catalysts include hydrogen peroxide, ammonium persulphate, tertiary butyl hydroperoxide, and tertiary butyl perphithalic acid. The water-soluble polyesters produced when operating in the manner described are generally slightly acid in nature and they may be used in the acid condition without the necessity of any solubilizing agents However, it is also possible to neutralize the solutions of said polyesters with any suitable alkali and, accordingly, the products may be used as neutral, alkaline, or acid solutions Additionally, suitable filling pigments and/or fibrous materials may be used in conjunction with the polyesters. In order that those skilled in 'the art may better understand how the present invention may be carried into' effect, the following examples are given by way of illustration and not by way of limitation All

parts are by weight. EXAMPLE 1 hydroxyl functionality of sorbitol hydra 15 randox 8 is 3 7. The polymerizing dibasic acids found suitable in producing the aforedescribed insoluble polyesters include maleic acid (or;anhydride) and fumaric, itaconic and carbic acids and mixtures of these acids. The preferred non-polymerizing dibasic acids found eminently suitable are phthalic and isophthalic acids since they present the advantage of imparting toughness to the products. Other aromatic acids, for example, tetrahydrophthalic and terephthalic acids may be used Additionally, oxalic, malonic, succinic, glutaric, adipic, pimelic, azelaic, and sebacic acids and their derivatives, for example, substituted succinic acids, such as butyl succinic acid, may be used to advantage These acids do not contain ethylenic unsaturation. The process which may be employed in producing products in accordance with this invention may be varied within wide limits One suitable method of effecting reaction is by the process of fusion of ithe ingredients In this process, the ingredients are heated together, preferably in an inert atmosphere, until suflicient water of esterification is evolved and taken off The finished product is then cooled and is ready for use As an alternative method, azeotropic distillation of the water of esterification may be effected in the presence of a volatile organic substance capable of forming a suitable azeotrope with the water and dissolving the resin Entraining agents which may be employed include xylene and benzene as well as others At the conclusion of the reaction, when the resin formation takes place in a solvent, it is desirable to remove the solvent by strong blowing with an inert gas or, alternatively, by the application of vacuum. The proportions of randox polyhydric alcohol found suitable may vary from O 8 mol to 1 8 mols per each mol of 'combined saturated and unsaturated acids The quantity of saturated dibasic acid generally employed may be between 0 4 and 2 0 times ithe molecular amount of unsaturated dibasic acid used. Stated on a molar basis, for each mol of unsaturated dibasic acid there may be used from 0 4 to 2 0 mols of saturated dibasic acid. The water-soluble esters produced by this process dissolve readily in water Suitable catalysts, for example, free radical catalysts and, if desired, accelerators, may be added Acid Number A water-soluble polyester was prepared by reacting in an agitated reactor equipped with a reflux condenser and a Dean-Stark separatory trap 600 parts of sorbitol hydra 15 randox 8, having a diol ratio of 1 61, 111 parts of 95 maleic anhydride, 75 parts of phthalic anhycdride and 60 pants of xylol This mixture was refluxed continuously at 145 -1550 C. and water of esterification separated continuously in the trap When

no' more water 100 was passed off, the temperature was maintained at 145 -155 CC and the reactor was then arranged to provide for distillation A stream of nitrogen was blown through the contents of the reactor until all the xylol had 105 been removed The water-soluble polyester produced had the following characteristics: 24.5 Viscosity: Z-2 to Z-3 Water solubility: Completely soluble in all proportions. In order to convert the polyester thus obtained into a cured product, the product of the above example was mixed with water and catalyst in the following proportion: parts by weight of the soluble poly 115 ester, 15 parts of water and 2 parts of tertiary butyl perphthal:c acid This soluble resin mix was cured at 150 'C for one-half hour to pro785,980 duce a tough, tack-free, strongly cohesive mass which was substantially insoluble in water. EXAMPLE 2 Employing the identical process steps of Example 1, another wate%-soluble polyester was prepared by reacting 1290 parts of sorbitol randox 8, 600 parts of sorbitol hydra 15 randox 20, 497 parts of fumaric acid and 225 parts of phthalic anhydride Water-soluble polyester products so produced had the following characteristics: An acid number of 53, a viscosity of Z-2 ( 75 % solids in water) and water solubility, completely soluble in all proportions This water-soluble polyester was mixed with water and catalyst in the following proportions: parts of polyester, 20 parts of water and 1 part of tertiary butyl perphthalic acid The water was evaporated off at 1000 C to leave a clear mixture of the polyester which cured at 'C to a tough, cohesive mass which was substantially insoluble in water This cured product possessed greater cohesive strength than the corresponding product produced in accordance with Example 1. The water-soluble polyesters produced in accordance with this invention have a wide field of uses as previously mentioned For example, they find utility in many industrial applications such as modification of properties of webs and textiles, for altering the characteristics of paper, for use in printing systems suitable for printing on paper, textiles and plastics They are readily transportable to their point of use in water systems and are readily employed as such As mentioned previously, they may be catalyzed initially or catalysts may be added just prior to their use Additionally, they may be modified with various pigments land fillers, and other water-soluble materials such as gums, starches, proteins and wetting agents.

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* GB785981 (A)

Description: GB785981 (A) ? 1957-11-06

Improvements in or relating to electric coffee mills

Description of GB785981 (A)

PATENT SPECIFICATION 785,981 Date of Application and filing Complete Specification: Dec 7, 1954. No 35367/54. Application made in Spain on Dec 7, 1953. Application made in Spain on Dec 7, 1953. Application made in Spain on Dec 7, 1953. Complete Specification Published: Nov 6, 1957. Index at acceptance: -Class 59, A 17. International Classification:-BO 2 c. COMPLETE SPECIFICATION Improvements in or relating to Electric Coffee Mills I, JO 515 FRANCESCH CAZORLA, a Spanish subject, of 19, San Gervasio Street, Barcelona, Province of Barcelona, Spain, do hereby declare the invention, for which I pray that a patent may be granted to me, 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 improvements in electric coffee mills. The connection of an electric coffee mill to aln electric supply source has previously necessitated the use of a length of conductor which may become worn and thereby be inconvenient It is an object of the present invention to overcome such a disadvantage by modifying the

construction of electric coffee mills. According to the present invention there is provided an electric coffee mill comprising a a body portion, a coffee grain receiving cover forming with said body portion a grinding chamber therebetween, an electric motor mounted within said body portion, a grinding member located within said grinding chamber and driven by said motor, electrical connecting means being provided on the exterior of the mill for direct electrical connection thereby of the electric motor to an electricity supply source, the body portion being constructed such that it can readily be grasped by hand and thereby manipulated to effect said connection to an electricity supply source. Preferably said electrical connecting aneans are constructed such that when connected to an electricity supply source they furnish a holding support for the mill during the grinding of coffee thereby. The body portion of the mill may be formed from a dielectric plastic material and the guides of the motor brushes form an integral part of the body portion Preferably the motor is located in a vertical position and its axis is supported by a collar at the upper end of the axis and the lower end of the axis is supported on an adjustably mounted ball bearing. Preferably prongs protrude from the mill for direct connection with an electricity supply source and the prongs may be mounted on a rotary plate which allows arrangement of the prongs, in horizontal or vertical position, according to the position of the sockets in the electric supply base with which connection is to be established. The cover, which covers the grinding chamber, may be provided with graduations so that the cover may also serve as a measure for the coffee and symmetrically arranged wings may be provided on the exterior surface of the cover which act as supports for the cover or mill in inverted position and also facilitate manipulation of the cover. An embodiment of the invention will now be described by way of example, with reference to the accompanying drawings, in which: Fig 1 is a vertical sectional view of an electric coffee mill showing the vertical mounting of the motor axis and the assembly and form of the motor brushes. Fig 2 is a perspective view of the electric coffee mill supported by hand in position ready for it to be connected directly with an electricity supply base. Fig 3 is a perspective view of the mill with the cover removed. Fig 4 is a perspective view of the cover supported on wings. Referring to the drawings, an electric coffee mill is composed of a hollow cylindrical base or handle piece 1, of dielectric plastic material, which widens at its upper part in the form, of a cup and has

an inner icover 2 which forms the base of the grinding chamber and serves besides as a cover for the mountings of the motor brushes The grinding chamber is formed by the said cover 2 and an exterior convex cover 3. The hollow body 1 is closed at its lower end by a screw threaded cover 4 of plastic material which supports the lower end of the axis of motor 5 and also supports the entire motor as it abuts the pack formed by the stator 7 A disc 41 is located between the cover 4 and the stator 7. Brushes 8, 8 ', guided in horizontal parts 1 ' of the tubular body 1, rub against the motor commutator 6, and, at the base of parts 1 ', are arranged the supports and guides 9, 9 ' of the springs pressing against the brushes. The motor axis arranged in the vertical position, is supported at its upper end 10 by an upper collar 11 only, which is located within a housing 11 ' formed integral with the body of the mill or of its general framework with interposition of a member which locates the collar under perfect conditions The collar 11 is maintained in appropriate position by action of a spring 12. The lower end of the motor axis is muounted on a nylon disc 14 on which seats a steel ball 13 The nylon disc is adjustable by means of an adjusting disc 15 of brass, or other suitable material The position of disc 15 is regulated by a screw 16 mounted in the lower cover 4 which has in its centre a housing 411 for the adjusting screw 16 and discs 14, 15 A small cover 17 serves to enclose and guard the adjusting screw 16. Once coupled, the various parts arranged in the above described way and completed simply by screwing in the lower cover 4 are in the correct position without necessity of adjustments Also, all the parts, which may be under stress, are fixed or fitted into the body or framework of insulating material. I he handle 1 may easily be held by hand as shown in Fig 2 due to the dimensions and shape of the handle 1. The upper part of the handle 1, whicl widens in the formn of a cup, has a laterally protruding portion 21 serving as base for an insulating plate 20 from which emerge prongs 19 These prongs extend beyond the perimeter of the mill so that, on connection, the body of the mill is spaced from base B Which feeds electricity to the motor The prongs 19 will have an appropriate length and form, to establish electrical connection when the mill is held against the plug base B It is convenient to keep the mill connected and supported by the prongs themselves, due to the short time necessary for grinding and to the characteristics of the motor. As electrical supply bases such as B, sometimes have their sockets in

horizontal position and soanetimes in vertical line, the prongs 19, which are conveniently connected with the motor, are mounted on an insulating plate 20 arranged over the protruding part 21 so that the position of the plate 20 can easily be altered in relation to the part 21 in order to have the prongs 19 in vertical or in horizontal position, as required, to correspond to the sockets of the plug base B It is understood that this position change of the prongs will only be effected when the mill is to be connected with the base in a position differing from the planned one, and, in general, it should not be changed once the necessary position has been arranged It is evident that the position change of the prongs does not modify or concern the connection with the 70 motor. On the convex surface of the cover 3 three symmetrically placed wings 18 are provided viaoh besides facilitating the handling of the cover provide stable support for the cover 75 and/or the mill, in inverted position. In operation, the mill is inverted, and the handle 1 is unscrewed and removed from the cover 3; for this purpose the part 2 has on its inner border a screw thread corresponding to 80 one provided on the exterior of a spigot on the cover 3. The receiver formed within the cover 3 receives coffee grains and has some parallel graduation marks 31 which indicate capacity, 85 weight or volume of coffee and serve to measure the coffee before and after grinding. After placing the required quantity of coffee grains in the concavity of the cover, the body of the mill is screwed on in inverted position, 90 and on connecting the mill in vertical position to the electricity supply in the manner just described, the coffee grains are ground by the fast rotating chopping knife 22 located on the upper end 10 of the motor axis emerging from 95 the base of the grinding chamber. The cover 3 encloses the grains during the grinding and, as it is of a transparent material, it is possible to see when all the grains have been ground 100 On inverting the mill, when disconnected, the ground coffee is located in the cover 3, and is available when the body of the mill is removed. In patent specification 739,246 there is 105 claimed a coffee grinder having a comminuting tool rotatable rapidly in a container for the material to be ground, the container being secured removably at its open end to a receiving member forming a base for the container 110 and through which the driving shaft for the comminuting tool extends, characterised in that the container is closed at its end remote from the open end and is shaped internally to narrow progressively towards the closed end 115

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* GB785982 (A)

Description: GB785982 (A) ? 1957-11-06

Improvements in or relating to the isolation of the antibiotic neomycin

Description of GB785982 (A)

PATENT SPECIFICATION Inventor:-WILLIAM CHARLES ALLEN. Date of filing Complete Specification: Jan 18, 1956. Application Date: Feb 16, 1955 No 4681/55. C(onmplete Specification Published,: Nov 6, 1957. 785,982 Index at Acceptance -Class 2 ( 3), AA 1 C( 1 A: ID 1: 2 A: 2 B), AA 2 AB. International Classification:-O 07 g. COMPLETE SPECIFICATION. Improvements in or relating to the Isolation of the Antibiotic Neomycin. We, BOOTS PURE DRUG COMPANY LIMITED, a British Company, of Station Street, Nottingham, 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 an improved process for the isolation from aqueous solutions of the antibiotic known as neomycin. Neomycin was first reported by Waksman et al (Science, 1949, 109, 305) and is obtained by the growth of a neomycin-producing strain of the micro-organism Streptomyces fradiae in an appropriate culture medium A number of methods have been described for the isolation from the culture medium of the neomycin so produced Thus it is known that the

neomycin can be isolated by adsorption on ion-exchange resins from which it can be subsequently removed by the use of mineral acid solutions: the greatly concentrated solutions of neomycin salts so obtained may be freeze-dried to obtain solid neomycin salts or may be subjected to further purification It is also known that neomycin may be isolated from culture media or from aqueous solutions in the form of its insoluble salt with anthraquinone-8-sulphonic acid; this salt may be collected and subsequently decomposed to recover the neomycin free from impurity. We have found that neomycin may be isolated from aqueous solutions containing neomycin in association with impurities, and particularly from culture media, in a very convenient manner through the agency of new and hitherto undescribed insoluble salts Thus we have found that neomycin readily forms water-insoluble salts with the di-alkyl esters of sulpho-succinic acid In this manner neomycin can be precipitated in substantially quantitative yield from aqueous solution and can be recovered from the precipitate by decomposition of the latter, for example by the use of a mineral acid. Accordingly our invention consists in a process for the isolation of neomycin from aqueous solutions containing neomycin in association with impurities and in particular from culture media which comprises precipitating neomycin from the aqueous solution in the form of its salt with a di-alkyl ester of sulpho-succinic acid, separating the precipitate so obtained and decomposing the precipitate to liberate neomycin therefrom. Certain di-alkyl esters of sulpho-succinic acid are already known as surface-active agents and a particularly valuable ester is commercially available under the trade name of "Manoxol OT" which is the di-octyl ester of sulpho-succinic acid in the form of its sodium salt The word "Manoxol" is a Registered Trade Mark. The precipitation of neomycin according to the invention may be effected by treating an aqueous solution of neomycin with a concentrated solution of a di-alkyl ester of sulpho-succinic acid preferably in the form of a water-soluble salt, for example, an alkali metal salt Where "Manoxol" OT is employed as the precipitating agent it has been found convenient to use a solution containing approximately 60 % w/v in a mixture of equal volumes of water and a lower aliphatic alcohol, i e one which is watermiscible The amount of di-alkyl ester of sulpho-succinic acid which is necessary to precipitate all the neomycin present in the original solution may be determined by 785,982 taking an aliquot of the latter and treating the aliquot with increasing amounts of the solution of sulpho-succinic acid ester until the point is reached at which further addition of the solution of sulpho-succinic acid ester does not result in the

formation of additional precipitate; the end point may be determined visually or alternatively the end point may be determined by adding an excess of the solution of sulpho-succinic acid ester and back-titrating with 13-diethylaminoethyl-l-cyclohexyl cyclohexane carboxylate hydrochloride as described by Carkuff and Boyd (J Aim Pharmn Assoc. Sci Ed, 1954, 43, 240) The amount of sulpho-succinic acid ester necessary to effect complete precipitation of the neomycin in the original solution is then calculated. When "Manoxol" OT is employed as precipitating agent it is found that the quantity required to effect complete precipitation of neomycin from aqueous solution is normally within the range of 1 5 to 2 0 parts by weight of "Manoxol" OT per part by weight of neomycin If the aqueous solution of neomycin employed is a liquor from the production of neomycin by fermentation it is preferable to subject the liquor to a preliminary treatment for the removal of 3 mycelia for example by filtration before treatment of the clarified liquor according to the process of the invention. The p H at which the precipitation of neomycin with the di-alkyl ester of sulphosuccinic acid is effected has been found to be critical This is illustrated in the case of "Manoxol" OT by the graph accompanying the Provisional Specification The results expressed in the graph were obtained by treating portions, each of 100 c c of an aqueous solution of neomycin sulphate containing 7,425 ulml (optical rotation 0.88 ') with 3 5 c c of 60 % w/v solution of "Manoxol" OT over a range of p H of 3 0-8 0 isolating the precipitates so formed, washing the precipitates with water and dissolving each precipitate in 50 c c of a lower aliphatic alcohol The optical rotation of each of the alcohol solutions was determined and represents a measure of the amount of neomycin precipitated at each of the values of p H employed In the graph shown in Figure 1 the optical rotation of the final alcohol solution is plotted against the p H at which precipitation was effected. It will be seen that the maximum amount of neomycin precipitation took place over the p H range of 6 8-7 0 and that outside these limits the amount of precipitation deC O creased sharply The above determination was made in a laboratory experiment using relatively small volumes of neomycin solution It has now been found that in the isolation of neomycin from large volumes 6.5 (of the order of 1,000 gallons) of solution the optimum recovery of neomycin in the form of its complex with an alkyl ester of sulpho-succinic acid can be accomplished over a slightly greater range of p H, namely approximately 6 6 to 7 7, and these are 70 therefore the preferred limits within which the process of the invention can be carried out.

The precipitate obtained in the process of the invention is not crystalline in charac 75 ter but takes the form of an oil or gum. This precipitate may be separated from the residual aqueous liquor by standard methods; thus the precipitate may be separated by centrifugation However we have found 80 that the precipitate may be isolated in a very convenient manner by the addition to the mixture of a quantity of a solid adsorbent such as kieselguhr; the precipitate is adsorbed by the kieselguhr and the solid 85 suspension so obtained is readily isolated by filtration. The decomposition of the salt of neomycin and the di-alkyl ester of sulphosuccinic acid may be effected by treatment A O of the salt in solution in a lower aliphatic alcohol with an excess of an acid, preferably a mineral acid to yield a precipitate of neomycin in the form of its salt with the acid employed; the precipitate is collected 95 When the salt has previously been adsorbed on kieselguhr the neomycin-kieselguhr mixture is suspended in a lower aliphatic alcohol and the kieselguhr is removed by filtration before treating the filtrate with mineral 100 acid Where the acid employed in the decomposition is sulphuric acid the resulting precipitate of neomycin sulphate is an oil and as previously stated it has been found that a very convenient method of isolating 105 the oil consists in treating the suspension with a quantity of kieselg'uhr on to which the oil is absorbed The kieselguhr is then isolated by filtration, washed with alcohol and slurried with distilled water The solu 110 tion of neomycin sulphate so obtained is freed from kieselguhr and treated so as to isolate solid neomycin sulphate, for example, the solution is evaporated to dryness to obtain solid neomycin sulphate which may '15 be subjected to further purification if necessary Alternatively the decomposition of the salt of neomycin and the di-alkyl ester of sulpho-succinic acid may be effected by treatment of the salt in alcoholic solution 120 with a strong base, for example, sodium hydroxide The alcoholic solution of neomycin in the form of its free base may then be treated with an organic solvent, for example, acetone in which the neomycin is 125 insoluble when the neomycin is precipitated. If the process of the invention is carried out on a large scale in which quantities of aqueous neomycin solution of the order of thousands of gallons are used, the procedure 13 M 785,982 for the decomposition of the salt of neomycin and the alkyl ester of sulpho-succinic acid as described in the preceding paragraph requires modification Thus the re53 moval of the kieselguhr from the kieselguhrneomycin-sulpho-succinic acid ester mixture after the latter has been suspended in alcohol is difficult owing to the extremely slow rate of filtration On a large scale lu therefore it is preferable to

carry out the procedure in the following manner To the initial aqueous solution of neomycin, which has been filtered to remove mycelia there is added a quantity of solid adsorbent such as kieselguhr in an amount approximately equal in weight to the quantity of neomycin sulphate present in the aqueous solution as estimated by optical rotation A solution of an alkyl ester of sulpho-succinic acid in an amount determined as hereinbefore described is then added to the neomycin solution which has been adjusted to a p H of 6.6-7 7, and the precipitate of neomycnalkyl ester of sulpho-3 uccinic acid complex 2.5 adsorbed on kieselguhr is isolated by filtration, and is then suspended in an aqueous lower aliphatic alcohol The kieselguhr which remains suspended in the solution is not removed and the suspension is treated with an excess of a mineral acid, for example sulphuric acid The salt of neomycin so precipitated becomes absorbed on the kieselguhr still present and the resulting solid mixture is isolated by filtration Solid 3 S neomycin salt, such as neomycin sulphate, may then be isolated in exactly similar manner to that described above for use on the small scale. The following non-limitative Examples illustrate the invention. EXAMPLE 1. In the isolation of neomycin from a fermentation liquor, the liquor containing 2,285 y/c c obtained by the growth of a neomycin-producing strain of the microorganism, Streptomnyces fradiae in an appropriate culture medium, is clarified by filtration The p H of the solution is adjusted to 6 7 by the addition of sulphuric acid To 450 3 34 litres of the solution is added 46 c c. of 60 % w/v "Manoxol" OT and the resulting solution is readjusted to p H 6 7 by the addition of sulphuric acid The solution is treated with 50 grams of kieselguhr with stirring to absorb the precipitated complex, and the solid so obtained is isolated by filtration, washed with 100 c c of water and sucked dry on the filter The kieselguhrneomycin mixture is stirred with 250 c c of ethyl alcohol for 0 5 hours and the kieselguhr is removed by filtration To the filtrate is added excess concentrated sulphuric acid ( 3 c c) when neomycin sulphate is precipitated as an oil The suspension is treated with 25 grams of kieselguhr with stirring and the solid mixture of neomycin sulphate on kieselguhr is isolated by filtration The neomycin sulphate is eluted from the kieselguhr by stirring with 300 c c of distilled water; the kieselguhr is removed by filtration and is washed by stirring with further quantities of 150 c c and 100 c c of distilled water The aqueous neomycin sulphate solution and washings so obtained are combined and are treated with stirring with 6 grams of animal charcoal The charcoal is removed by filtration and the filtrate is subjected to freeze-drying to obtain crude neomycin sulphate of

potency 800 y/mrg. This solid is purified by precipitation from aqueous solution by the addition of ethyl alcohol There is thus obtained 6 63 grams of neomycin sulphate with a potency of 1,000 y/mg representing a recovery of 87 %. EXAMPLE 2 85 In the isolation of neomycin from a fermentation liquor, approximately 3,000 gallons of liquor containing 4,870 y/c c, obtained by the growth of a neomycin-producing strain of the micro-organism Strepto 90 nyces fradiae in an appropriate culture medium are clarified by filtration The filtrate is collected in two portions, each of approximately 1,500 gallons, and each portion of clarified liquor is adjusted to a p H 95 of 6 6 + 0 1 by the addition of 50 % sulphuric acid 75 pounds of kieselguhr are added to each portion of clarified liquor, together with 35 gallons of 60 % "Manoxol" OT. The resulting mixture is well stirred and 100 the p H is readjusted to 6 6-7 0 by the addition of 50 % sulphuric acid Each portion is then treated in the following manner. The neomycin "Manoxol" OT complex adsorbed on kieselguhr is isolated by filtra 105 tion through a centrifugal filter, and is immediately slurried in 35 gallons of 95 % aqueous ethyl alcohol with the aid of a high speed stirrer To the suspension so obtained, concentrated sulphuric acid is added to 110 decompose the salt of neomycin and "Manoxol" OT, until the liquors acquire a p H of 0 6 The precipitate of neomycin sulphate adsorbed on kieselgubr thus obtained is removed by filtration, and is again 115 slurried in 30 gallons of 80 % aqueous alcohol, removed by filtration and again slurried in 30 gallons of 50 % aqueous ethyl alcohol and isolated by filtration The solid so obtained is stirred with 20 gallons of 120 distilled water and filtered, this process being repeated four times The aqueous neomycin sulphate solutions are combined and are treated with 14 kilograms of charcoal and 7 kilograms of kieselguhr The charcoal 125 and kieselguhr are removed by filtration and neomycin sulphate is precipitated from the filtrate by the addition of 75 gallons of 95 % ethyl alcohol The supernatant liquor is removed by decanting and the residual oil is dissolved in distilled water to give a 30 % w/w solution of neomycin sulphate, as determined by optical rotation. This solution is adjusted to p H 6 5-6 8 by the addition of 10 % w/v sodium hydroxide solution, and is treated with 0 3 grams of charcoal per gram of neomycin sulphate as estimated by optical rotation The charcoal is removed by filtration and the filtrate is subjected to freeze-drying From the original 3,000 gallons of clarified liquor there is thus obtained 36 7 kilograms of neomycin sulphate with a potency of 685 Wi/1 ng.

The term "lower aliphatic alcohol" as used above means an aliphatic alcohol which is water-miscible Methanol or ethanol are preferred examples of such alcohols.

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* GB785983 (A)

Description: GB785983 (A) ? 1957-11-06

Improvements in and relating to the production of polymeric and copolymericproducts

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PATENT SPECIFICATION Inventors: CLEMENT HENRY BAMFORD and AUBREY DENNIS JENKINS Date of filing Complete Specification Feb 21, 1956. Application Date Feb 22, 1955. 785,983 No 5233/55. Complete Specification Published Nov 6, 1957. Index at Acceptance:-Class 2 ( 6), P 7 (D 2 A 1: K 8), P 7 P(AD: 3: 6 D), P 7 T 2 (D: E: X), P 8 D(ZA: 2 B 2: 3 A), P 8 K 7, P 8 P( 1 D: 3: 6 D), P 8 T 2 (D: E: X). International Classification: -CO 8 f.

COMPLETE SPECIFICATION Improvements in and relating to the Production of Polymeric and Copolpymeric Products We, COURTAULDS LIMITED, a British Company, of 16, St Martin's-le-Grand, in the City of London, England, 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 production of polymeric and copolymeric products. It is well-known to copolymerise a mixture of two or more polymerisable compounds to produce random copolymers in which the distribution of the different monomer species in the polymer molecule depends upon the reactiveness of the various monomers During recent years different types of copolymers have been made, namely the grafted and block copolymers; grafted copolymers consisting principally of acrylonitrile are described in British Patent Specification No 715,194 and block copolymers are described by Hicks and Melville in Nature, Volume 171 ( 1953), page 300 Known methods of making block copolymers however are not entirely satisfactory particularly in that the yield is low and the products tend to be ill-defined. It has also been proposed in British Patent Specification No 626,155 to polymerise one or more of certain unsaturated compounds in the absence of artificial ultra violet light and in the presence of an organic azo compound in which the valencies of the azo group are attached to different non-aromatic carbon atoms. The object of the present invention is to produce block polymers and copolymers of predetermined constitution. According to the present invention block polymers and copolymers are obtained by polymerising a monomeric polymerisable ethylenically unsaturated compound in the presence of an initiator containing an azo group and also a functional group, for example a carboxylic group, capable of entering into coupling reaclPl tions, thereby giving an intermediate polymer having the functional group at one or both ends of the polymer chain, and thereafter coupling the intermediate polymer obtained with a compound having in the molecule two or more groups capable of reacting with the functional group or groups. In its preferred form two different intermediate polymers each containing one or two terminal functional groups are prepared and are then coupled together by a compound as defined to form the block copolymer The invention however includes the preparation of block polymers in which similar intermediate polymers are coupled Block polymers or copolymers may be prepared consisting of or containing intermediate, polymers of for example acrylic acid esters, methacrylic acid esters, acrylonitrile, styrene, vinyl acetate, vinyl chloride and

the vinyl pyridines. The functional groups of the initiating azo compound and the conditions of polymerisation should be chosen so that the tendency of the initiator to undergo chain transfer reactions is kept at a minimum; it has been found that a relatively high concentration of initiator of the order of 1 per cent of the weight of monomer is preferable, and it is also preferred to carry out the polymerisation in solution in a nonreactive solvent. The preferred initiator containing a functional carboxylic group is yyl-azo-bisy-cyanovaleric acid Before the coupling reaction the carboxylic groups may be converted into the more reactive acid chloride (CO Cl) group Examples of suitable coupling compounds capable of reacting with functional carboxylic or acid chloride groups are aliphatic diols or diisocyanates of the type OH R OH and OCN R NCO, R being a polymethylene group, for example 1:6 hexane diol, 1: 10 decane diol and hexamethylene diisocyanate. The coupling compounds preferably have two reactive groups to give linear block polymers, but coupling compounds having three or more reactive groups may also be used to give three-dimensional block polymers. The initial polymerisation gives rise to intermediate polymers having the functional groups at one or both ends If the intermediate polymer is represented as AA-AA and the radical containing the functional group is represented as X, the intermediate polymer blocks may be AA-AAX or XAA-AAX, depending on the amount of catalyst used The intermediate polymers can then be coupled in a variety of ways For example, if the coupling component is represented as YRRY where Y is a reactive group, the coupling of AA-AAX with another intermediate polymer of the same type, namely BB-BBX will give rise to a mixture of polymers and copolymers as follows: AA-AARRBB-BB AA-AARRAA-AA BB-BBRRBB-BB If it is desired to avoid the formation of a mixture of copolymers one of the intermediate polymers may be first reacted with a large excess of the coupling compound to give AA-AARRY and then reaction with the second polymer block will give the copolymer AA-AARRBB-B 13. With intermediate polymers of the type XAA-AAX and XBB-BBX free coupling will give a copolymer chain of the type in which the order of the blocks A, and BE is random. By reacting one of the intermediate polymers with a large excess of the coupling compound the order of the blocks may be regularised to all intents and purposes to give regular blocks of polymers of A and B. It is also possible to couple an intermediate polymer AA-AAX with an intermediate polymer XBB-BBX. Free coupling will give a mixture of polymers and copolymers but by

reacting one of the intermediate polymers with a large excess of the coupling compound copolymers of the form AA-AARRBB-BBRRAA-AA will be obtained. In accordance with usual practice, in the formulx of the copolymers given above, the linking groups formed by reaction of the end group X and the group Y of the coupling compound have been omitted. With coupling compounds containing 3 or more reactive groups a range of three-dimensional block polymers may be obtained in a similar way. The invention is illustrated by the following examples. EXAMPLE 1. ml of methyl methacrylate and 0 509 gram of yyl-azo-bis-y-cyano-valeric acid were added to 400 ml of benzene The reaction mixture was rendered free from oxygen by the standard degassing method of freezing under high vacuum and thawing out several times It was then heated in an inert atmosphere at 900 C for 45 minutes. At the end of this time the mixture was poured with stirring into 2 litres of methyl alcohol The precipitated polymer was filtered, redissolved in benzene and reprecipitated by methyl alcohol Finally, the polymer was dried in vaeuo. The equivalent weight of the polymer was found by titration in benzene with standard sodium methoxide to be 15300. 1.72 grams of polymethyl methacrylate from 85 the above preparation were refluxed overnight with pure thionyl chloride to convert the COOH end groups into the more reactive COCI groups The excess of reagent was completely removed ina vacuc A solution of 6 6 milli 90 grams of 1: 6 hexane diol in dry methyl ethyl ketone was added and the mixture reacted overnight at 90 The polymer was isolated by precipitation in methyl alcohol. Measurements of the intrinsic viscosity of 95 solutions of the original and final polymers showed that the molecular weight had increased by a factor of 1 7. The original polymer was of the form AA-AAX and the final polymer consisted 100 of two coupled polymer blocks AA-AARRAA-AA where AA-AA represents the original polymethyl methacrylate and RR is a hexane chain. The step of converting the COOH groups 105 in the intermediate polymer into COCI groups may be omitted if desired but the subsequent coupling reaction required several days. EXAMPLE 2. A mixture consisting of: 110 Styrene 100 ml. o-dichlcrobenzene 900 ml. yy' azo-bis cyanovaleric acid 2 05 g. was heated at 100 for 2 ' hours after removal of oxygen from the

system The polymer was 115 isolated by precipitation in methyl alcohol and purified by reprecipitating from benzene three times. The equivalent weight of the polymer was found, by titration in benzene with sodium 120 methoxide, to be 6650. 2.48 grams of polymer from the above preparation were refluxed overnight with pure thionyl chloride The excess of reagent was completely removed in vacuo A solution of 125 -A.RRB-RRB-RRA RRB-RRA-RRA RRA RR785,983 the form XBB-BBX with an equivalent weight of 6950 This polymer was reacted 65 with a large excess of 1:6 hexane diol by esterification with a 100 fold excess of the diol in methyl ethyl ketone containing about 5 per cent by weight of the sulphuric acid The polymer was isolated by precipitation in 70 methyl alcohol and purified by reprecipitation twice from benzene Residual methyl alcohol was removed in vactol. 0.82 gram of this treated polymer was heated with benzene 9 75 milligrams of hexa 75 methylene diisocyanate in nitrobenzene solution for six days at 1200 C and the polymer recovered by precipitation in methyl alcohol. Measurements of the intrinsic viscosity of solutions of the original and final polymers 80 showed that the molecular weight had increased by a factor of 4 1, so that on average four blocks of the original polymer had been coupled to form one molecule The polymer may be regarded as a regular block polymer 85 of styrene polymers coupled by hexamethylene diisocyanate residues.

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