* GB785929 (A)

Description: GB785929 (A) ? 1957-11-06

Improvements relating to fabric tentering and drying machines

Description of GB785929 (A)

PATENT SPECIFICATION Inventor: GUSTAV MOHRING A; Date of application and filing Complete Specification: Aug 2, 1956. o 23887156. Complete Specification Published: Nov 6, 1957. Index at acceptance: -Class 34 ( 1), DIA, D 8 (B: G: J). International Classification:-DO 6 c. COMPLETE SPECIFICATION Improvements relating to Fabric Tentering and Drying Machines We, FAMATEX G m B H, of Kornwest length of the web. heim, Stuttgart, Germany, a Company or This arrangement, which results in parganised under the laws of Germany, do ticularly good use of space, not only simplihereby declare the invention, for which we fies maintenance of the machine, but also 50 pray that a patent may be granted to us, and allows trouble to be overcome and the the method by which it is to be performed, machine to be cleaned without difficulty, to be particularly described in and by the since all important parts of the machine are following statement: easily accessible after the top part has been The present invention relates to tenteringlifted 55 machines adapted for tentering and drying The subject of the invention is illustrated travelling webs or the like of woven or in a constructional example in the accomknitted fabrics or similar materials panying drawing, wherein:An important object of the said invention Figure 1 is an elevation of the machine as is to provide simple means whereby a filter seen in the direction of travel of a fabric 60 employed in connection with the drying web therein. means may be kept clean Another object Figure 2 is a diagrammatic detail crossof the said invention is to improve the de section through nozzles of the drying means.

sign and construction of such machines, par Figure 3 is a sectional elevation of a dustticularly in regard to the mounting of the filter with a movable dust-removing suction 65 drying means therein, so that not only is in mouthpiece, and creased drying power obtained with less use Figure 4 is a sectional elevation of a filter of space as compared with machines of this arrangement comprising a fixed dust-removkind hitherto known, but also accessibility of ing suction device in operative relation with working parts is afforded so that they can be a movable filter surface 70 kept clean, whereby the maintenance of the In Figure 1, lower and upper nozzle boxes drying means is substantially simplified and 1 and 2 are respectively arranged below and cheapened above the web B which is carried through The invention is concerned with tentering the machine in a tensioned condition on and drying machines of the kind comprising tentering chains 3 Each of the boxes 1 and 75 nozzles for blowing a drying medium, such 2 has a number of slot nozzles 4 situated as heated air, on to a fabric web the said side by side, the said nozzles being prefernozzles being connected with fans or blowers ably of the tapered form presenting a triwhich suck the drying medium through fil angular cross-section as seen in Figure 2. ters and heaters before blowing it on to the The nozzles of the lower box 1 are presented 80 web upwardly with their narrow ends towards According to the present invention the the web B and the nozzles of the upper box filters of the machines referred to are pro 2 are reversely presented The orifices of vided with cleaning means adapted for re the nozzles are near to the web B and the moving impurities, such as dust, fibres and upper and lower nozzles 4 are arranged op 85 the like, retained by the said filters posite one another. In addition, the machine is so devised The drying medium is circulated for exthat its top part can be turned hingedly ur ample by two fans or blowers 5 and 6, fitted wards, together with an upper nozzle box in the machine frame 7 at respective sides of fitted with nozzles which are directed down the web B and driven by means of electric 90 wardly upon the web, the pivot axis of the motors 8 through the medium of suitable hinge mounting being parallel with the gearing such as the belt and pulley gearing shown The fans 5 and 6 communicate with respective lower and upper nozzle boxes 1 and 2 by means of delivery or pressure ducts 9 and 10 in such a way that the pressure side of the left-hand fan 5 is connected by the duct 9 with one end of the lower nozzle box 1, and the pressure side of the right-hand fan 6 is connected by the duct 10 with the opposite end of the upper nozzle box 2 The suction sides of the two fans communicate in each case with the intermediate spaces 11 formed between the nozzles 4 and the web B, heating and filtering means being disposed in the suctions as

hereinafter described. At the suction side of the fan 5 there is a heater 12 and a filter 14, and at the suction side of the fan 6 there is a heater 13 and a filter 15 In each case, the heater and filter are advantageously combined to form a unit Thus, the suctions of the fans 5 and 6 suck in air from the intermediate spaces 11, which air becomes heated and filtered before being passed through the ducts 9 and 10 to the nozzle boxes. The ends of the nozzle boxes I and 2 are made oblique to the vertical and parallel with one another as shown in Figure 1 in order to make the construction as compact as possible and to make the best use of the space available This results in sufficient space to the left and right of the nozzle boxes, above and below, to accommodate the filters 14 and 15, the heaters 12 and 13 and the fans 5 and 6, which are advantageously combined to form two units As will be seen, the oblique formation of the box ends provides a space in the top lefthand corner of Figure 1 for the one unit 5, 12 14 and a space in the bottom right-hand corner for the other unit 6, 13, 15. Thus the drying medium circulates as follows: Starting from the left-hand fan 5. this fan forces the drying medium through the duct 9 into the lower nozzle box 1, and thence through the slot nozzles 4 upwardly against the web B which is moving past The drying medium is deflected by the web, as indicated by the arrows in Figures 1 and 2, and collects turbulently in the spaces 11 between the nozzles and the web B The drying medium is then aspirated from the spaces 11 by the right-hand fan 6 through the filter and the heater 13, and is in this way smiultaneously cleaned and heated before being passed through the duct 10 into the upper nozzle box 2 and through the nozzles 4 down on to the web B Here again the drying medium after acting on the web collects in the upper intermediate spaces 11, and is aspirated by the left-hand fan 5 via the filter 14 and the heater 12, the circuit being now complete. As already mentioned, the filters are provided with an automatic cleaning means comprising a vacuum chamber 16 or the like subjected to suction and connected by hose lengths 18 with two suction mouthpieces 17, one mouthpiece being movably arranged against the filter 14, the other against the 70 filter 15 (Figure 3) The suction mouthpieces 17 are approximately as wide as the filters, and are supported in guides 19, so as to be capable of being moved to and fro directly before the filters by driving means 75 provided on the machine, thus aspirating away into the chamber 16 impurities such as dust, fibres, portions of woven fabric and the like deposited on the filters The filter material may be of the textile or metallic 80 type, and the impurities can be removed from the chamber 16 at certain intervals or continuously The

drive for the filter cleaning means is so devised as to be capable of being switched on and of T independently of 85 the putting of the remainder of the machine into or out of action. Alternatively, a fixed mouthpiece may be used and the filter 15 can be moved in relation to the mouthpiece, as illustrated in 90 Figure 4 Both textile and metallic filters can be used in this case also, and can be guided in the form of a band moving over rollers 20, or alternately wound on to and off these rollers The filters may be con 95 tinuously cleaned if desired, or the cleaning means may be put into action only intermittently. In order that the web B may be examined at any time, and in order that repairs and 100 fairly extensive cleaning operations may be carried out on the machine at certain intervals without hindrance, the top part 21 of the machine including the upper nozzle box 2 and its nozzles 4 is so devised as to be 105 capable of being hingedly moved upwards and to be covered by a hinged lid 24 The positions of such top part and lid when lifted by turning them about their hinges are indicated by chain lines in Figure 1 While 110 the lid 24 can be turned upwards about the articulation 25, the top part 21 can be pivoted upwards about an articulation 22 fitted to the frame 7 above the left-hand filter 14, a counterweight 23 fitted to the top 115 part facilitating this movement. A joint surface 26 on the end of the duct is made oblique to suit the obliquity of the adjacent end of the upper nozzle box 2. Thus, this joint surface 26 automatically 120 makes a sealed closure with the upper nozzle box 2 when the latter is lowered into its working position, loss of pressure being thereby avoided in a simple manner. The arrangement results in good accessi 125 bility to all important parts of the machine, even if a number of such machine sets are combined to form a fairlv large plant, which can be done particularly easilv in this case, since each set is independent of another 130 785,929 785,929 2

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* GB785930 (A)

Description: GB785930 (A) ? 1957-11-06

Thermosetting etherified resins

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PATENT SPECIFICATION Inventors: JOHN EDWARD SEAGER WHITNEY and BASIL WILLIAM BROOK 785930 Date of filing Complete Specification: Aug 12, 1954. Application Date: Aug 12, 1953. Complete Specification Published: Nov 6, 1957. Index at acceptance:-Class 2 ( 5), R 27 K 3 (B: CW M 5: M 6). International Classification:-CO 8 g. COMPLETE SPECIFICATION Thermosetting Etherified Resins We, BRITISH RESIN PRODUCTS LIMITED, a British Company, of 21, St James's Square, 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 - The present invention relates to a process for the production of thermosetting resin compositions and to the compositions so produced. In particular the present invention is for an improved process for the production of etherifled resins from the initially formed condensation products obtained by reacting phenols with lower aliphatic aldehydes. It is known from Belgium Patent 503,549 that etherified resins can be obtained by etherifying the phenolic hydroxyl groups of phenol-aldehyde condensation products having the formula }.CH Rx y with a halo-epoxyalkane such as epichlorhydrin where in said formula CHR is a bonding group resulting from the condensed aldehyde, X and Y are hydrogen or alkyl or hydroxyl groups, and m is a whole number at least equal to 3 Such phenol-aldehyde condensation products have the

structure of typical novolak resins and do not possess any hydroxyalkyl groups attached to the phenolic nucleii It is also known that etherified resins can be obtained by reacting a phenolic mixture containing hydroxyalkyl phenols with a polyreactive etherifying agent selected from the group consisting of epihalogenhydrins and di1 oenhydrins in an alkaline medium. By the term " hydroxyalktyl phenols " is meant the initially formed phenolic products derived from the condensation of phenols with lower aliphatic aldehydes under alkaline con 40 ditions Such reactions may be represented: where the substituent group -CH OH is R attached to the aromatic nucleus of the phenol in the ortho and/or para-positions with respect to the phenolic hydroxy group In the formula, R is a lower alkyl group, i e, an alkyl group containing not more than four carbon atoms. These etherified resins have properties which depend on the starting material taken and on the precise reaction conditions employed for the etherification reaction and for the preparation of the phenolic mixture. An object of the present invention is to provide a process for the production of resinous compositions which are particularly suited for use as adhesives in the manufacture of glass fibre laminates A further object of the present invention is to provide a process for the production of etherified resins with particularly low viscosity values and high reactivity towards acid and amino curing catalysts. It has now been found that the above objects can be achieved by careful control of the reaction conditions and the starting materials employed. According to the present invention the process for the production of an etherified resin comprises condensing one molar proportion of a reactive monohydric phenol with from 0 5 to 0 75 of a molar proportion of No 22250/53. formaldehyde at a temperature above 800 C. and in the presence of an amount of an alkaline condensing agent lying within the range 1/200 to 1/10 of the amount molecularly equivalent S to the monohydric phenol until substantially all the formaldehyde has condensed and thereafter etherifying the condensation product in an alkaline medium with excess (as hereinafter defined) of an epihalogenhydrin or a dihalogenhydrin at a temperature not above 1000 C. By the term " reactive monohydric phenol" is meant any phenol containing at least two unsubstituted reactive positions and any such phenol or mixtures of such phenols either among themselves or with other phenols may be employed in the process of the present invention As examples may be mentioned phenol; ortho-, meta or paracresol; the

2: 3-, 2: 5 and 3: 5-xylenols; para-tertiary butyl phenol; para-amyl phenol; para-phenyl phenol; para-octyl phenol; and para-nonyl phenol The use of phenol and of the cresols, particularly meta-cresol, give rise to particularly useful products. Examples of the epihalogenhydrins and. dihalogenhydrins are epibromhydrin, alphaor beta-dichlorhydrin or dibromhydrin and epichlorhydrin, this last mentioned compound being the preferred etherifying agent. The condensation reaction is carried out by mixing the monohydric phenol with the formaldehyde preferably in an aqueous medium containing the alkaline condensing agent and the mixture is heated to a temperature in excess of 800 C Most suitably the condensation is carried out by maintaining an aqueous reaction mixture under reflux conditions at atmospheric pressure at approximately 1000 C. The formaldehyde is most suitably added to the phenol in the form of an aqueous formalin solution although it may be added in the form of a solid compound, e g, paraform, which releases formaldehyde under the conditions of the condensation reaction In the process of the present invention the molar proportion of formaldehyde to monohydric phenol must be in the range 05-0 75: 1. Any alkaline condensing agent known to be capable of bringing about the condensation of a phenol with formaldehyde may be used in the process of the present invention but most suitable are the alkaline metal or alkaline earth metal hydroxides or ammonium hydroxide. The amount of alkaline condensing agent present is within the range 1/200 to 1/10 of the amount molecularly equivalent to the monohydric phenol taken are used. The condensation reaction is continued for such a time, depending on the temperature employed, that the desired degree of condensation takes place and substantially all the formaldehyde has reacted Preferably the amount of uncondensed formaldehyde present at the end of the condensation reaction is less than 1 % by weight of the weight of the reaction mixture The condensation reaction should not, however, be continued beyond the point where uncontrollable gelation would occur on reaction with the halogenhydrin 70 The etherification stage of the process of the present invention is conducted with the monohydric phenol-formaldehyde condensation product dissolved or dispersed in an alkaline medium Preferably, the reaction is carried 75 out with the phenol-formaldehyde condensation product dissolved in an aqueous alkaline medium such as an aqueous solution of an alkaline metal hydroxide or quaternary ammonium hydroxide It is further preferred 80 that the amount of alkali present be at least molecularly equivalent to the number of phenolic hydroxyl groups present in the reaction medium Most suitably the etherification reaction is carried

out directly on the aqueous 85 medium obtained from the condensation step of the process of the present invention after there has been added thereto sufficient alkali to make the concentration of the latter at least molecularly equivalent to the total number of 90 phenolic hydroxyl groups present in the system. The etherification reaction, which is an exothermic reaction, proceeds very readily and may be initiated at room temperatures and 95 maintained without the application of heat. The speed of the etherification may be increased by increasing the temperature to, for example, 1000 C, but it should be understood that higher temperatures should not be 100 employed because at such temperatures the side reactions become more advanced It is preferred that the reaction mixture should be agitated throughout the reaction period and that the temperature should not be allowed to 105 exceed 600 C. In order to produce the low viscosity etherified resins of the present invention it is essential to employ excess of the etherifying agent in the etherification reaction By excess 110 etherifying agent is meant an amount of agent at least in excess of the amount molecularly equivalent to the phenolic hydroxyl groups present in the system It is preferred to employ at least a 50 % excess of the etherify 115 ing agent, i e, an amount of reagent at least one and half times as great as the amount required to react completely with the phenolic hydroxyl groups present in the system. The etherification may be arrested at any 120 desired stage by neutralisation of the alkaline medium and/or separation of the resinous etherification product The etherification reaction should be allowed to continue until it is substantially complete when it will be found, 125 in those cases in which an aqueous medium has been employed, that the etherified product will separate from the aqueous alkaline medium and may easily be separated therefrom and purified by water washing 130 785,930 78,3 The resultant etherification product may then be dehydrated and excess etherifying agent removed by distillation at atmospheric or subatmospheric pressures Azeotropic dehydration may be employed if desired, and may be effected by distillation of the etherification product after the addition of a substantially water immiscible substance or mixtures of substances which are capable of forming binary, ternary or higher azeotropes with water. Typical of these substances are the aliphatic monohydric alcohols containing 4 to 8 carbon atoms, benzene, toluene, xylene and mixtures of such compounds As distillation proceeds the water is separated from the distillate and the non-aqueous material returned continuously, or intermittently to the distillation vessel When the azeotropic

distillation is carried out in the presence of the above mentioned alcohols, it is found that the solubility of the resultant dehydrated resin in nonpolar solvents such as " Cellosolve" (Registered Trade Mark), dioxan or cyclohexanone and its lower aliphatic substituents is improved due to the partial etherification of the hydroxyalkyl groups with the aliphatic alcohol employed. The dehydrated etherified resin may be cured by heating at any convenient pressure in the presence of a curing catalyst The curing catalysts which are capable of enhancing the rate of cure of the etherified resin products are amino compounds and weak acids. Amines, especially tertiary amines and diamino compounds, are preferred Suitable compounds are triethylamine, pyridine, piperidine, ethylene diamine, diethylaminoethylamine, beta-dimethylaminopropionitrile, dicyandiamide-this latter is particularly useful because it is insoluble in the etherified resins at ordinary temperatures and does not dissolve and become active until its melting point is approached. The etherified resins produced by the process of the present invention have low viscosity values and are particularly useful in the manufacture of glass fibre laminates. The following examples illustrate the manner in which the process of the present invention may be carried out in practice, the parts given being by weight. EXAMPLE 1. 1410 parts by weight phenol and 600 parts by weight formalin ( 40 % w/v aqueous formaldehyde solution) are mixed in the presence of 15 parts by weight of sodium hydroxide dissolved in 75 parts by weight of water, are heated to reflux and maintained at reflux temperature under atmospheric pressure for 2 J hours, at the end of which time there was only 0.09 l% by weight of free formaldehyde in the reaction mixture The batch is then cooled to room temperature and 660 parts by weight of sodium hydroxide dissolved in 1500 parts by weight of water added while cooling is maintained 2475 parts by weight of epichlorhydrin is then added at a batch temperature of below 300 C and allowed to react without application of external heat for 18 hours by which time the etherified product has separated The aqueous layer is removed and the non-aqueous layer washed with successive portions of water until the p H of the wash water reaches 7-8 The resin is then freed from water and excess epichlorhydrin by distillation at a pressure of 3 cms Hg to a temperature of C 2225 parts by weight of a pale yellow resinous syrup of 30 stokes viscosity result, Product A. To each of 50 parts by weight portions of Product A contained in glass te, t tubes, were added 2 5 parts by weight of the following catalyst After stirring in the catalyst the tubes were immersed in a water bath

at 500 C, unless otherwise stated, and the time to gelation observed The temperature attained by virtue of the exothermic reaction was also noted. Gelation Diethylamine Triethylamine Pyridine Piperidine Benzyl dimethylamine 13-dimethylamino propionitrile Ethylene diamine Diethylamino ethylamine Overnight l-t hours mins. mins. Overnight 2- hours mins. Overnight Max Temperature Developed 580 C. 680 C. 900 C. 890 C. 600 C. 1500 C. Bath temperature -80 C. Six " x 1 " joints were prepared by bonding degreased and potassium dichromate etched SWG aluminium clad duralumin with Product A containing 5 % triethylamine The joints were cured at a pressure of 10 p s i with the following temperature schedule: 50 to 95 1200 C in 50 minutes and then held at 1200 C for 30 minutes. 785,930 The strengths of the joints when tested to failure in a tensometer were found to be as follows: Joint No Failing Load (lbs) 1 952 2 3 4 2090 1433 1600 1060 1710 A laminated board was prepared from twelve 9 x 9 " sheets of glass fabric impregnated with Product A to which-had been added 5 % triethylamine The laminate was cured between two plates of toughened glass, which had been previously coated with paraffin wax, according to the following schedule: 16 hrs at room temperature under a 28 lb weight, followed by 1 hour at 700 C, then at 1200 C under a pressure of 10 lbs /sq inch. The cured board possessed the following properties: Flexural strength Young's Modulus Water Absorption after 24 hrs immersion Volume Resistivity Power Factor: at 800 c/s. at 1 Mc/s. 44,000 p s i. 2.6 x 101 p s i. 0.20 % 1 x 1014 ohms/cm ' 0.001 0.02 Specific Inductive Capacity: at 800 c/s 3 92 at 1 Mc/s 4 41 A casting prepared from Product A in conjunction with 3 % ,o triethylamine was found after cure to possess the following properties: Flexural strength Young's Modulus Water absorption after 24 hours immersion 12,000 p s i. 4.3 x 105 p s i.

0.12 % It will be seen from the above example that an etherified resin prepared from phenol, formaldehyde and epichlorhydrin has very good curing characteristics in the presence of various amine catalysts It is also a good adhesive for aluminium and can be cast into a resinous composition with useful physical properties In particular it can be used as the impregnating resin for glass fabrics in the production of laminated boards with exceedingly good physical characteristics It can also be used for treating the surfaces of glass fibres prior to their impregnation with unsaturated polyester resins in the manufacture of laminated products. EXAMPLE 2. 470 parts by weight of phenol are mixed with 220 parts by weight of 40 % w/v aqueous formaldehyde, and 5 parts of sodium hydroxide dissolved in 25 parts water are added The mixture is then heated to reflux and maintained under reflux for 4 ' hours and cooled to room temperature The reaction mixture then contained 0 03 %,0 by weight of free formaldehyde A solution of 220 parts of sodium hydroxide in 500 parts of water was added slowly so that the temperature remains below 500 C This solution is then cooled to room temperature and 825 parts of epichlorhydrin added, and the mixture stirred without heating until more than 90 % of the sodium hydroxide has been consumed The stirrer is then stopped and the mixture allowed to separate into two layers, the aqueous layer being removed and the non-aqueous layer washed free from salt and sodium hydroxide then heated to 150 C under a pressure of 3 cm of mercury to give 680 parts of a viscous amber liquid containing 8 87 %,0 epoxy oxygen. A laminated board was prepared by impregnating twelve 7 x 7 " sheets of glass fabric with this resin to which 10 % of pyridine had been added The laminate was cured between metal plates for 60 minutes at 1200 C at a pressure of 25 lbs /sq inch and then stoved for a further 180 minutes at 150 C The cured board possessed the following properties: Flexural strength prior to stoving Flexural strength after stoving Flexural strength after 2 hrs immersion in boiling water Young's Modulus prior to stoving Water absorption after 24 hrs immersion in boiling water EXAMPLE 3 reflux peric 470 parts by weight of phenol and 260 parts 0 13 % by l by weight of 40 % w/v aqueous formaldehyde mixture was were mixed and 5 parts of sodium hydroxide of sodium E dissolved in 25 parts of water added The water adde mixture was then heated to reflux and main hours, the tained under reflux for 2 t hours, then 825 between 50 parts of epichlorhydrin added, and the mix stopped anc ture cooled to 50-60 C At the end of the into two la 51,000 lbs /sq in. 56,600 Ibs /sq in.

30,800 lbs /sq in. 5.5 x 10 ' lbs /sq in. 0.42 % d the reaction mixture contained veight of free formaldehyde This 105 s stirred vigorously and 220 parts hydroxide dissolved in 500 parts of d dropwise over a period of 2 temperature being maintained and 600 C The stirrer was then 110 d the mixture allowed to separate iyers and the non-aqueous layer SO 785,930 molecularly equivalent to the number of phenolic hydroxy groups present in the reaction medium. 7 A process as claimed in any of the preceding claims, wherein the etherification reaction mixture is agitated throughout the etherification reaction and the temperature of the reaction mixture does not exceed 600 C. 8 A process as claimed in any of the preceding claims, wherein at least a 50 % excess of the etherifying agent is employed. 9 A process as claimed in any of the preceding claims, wherein the etherified product is dehydrated by distilling the water therefrom. A process as claimed in any of the preceding claims, wherein the monohydric phenol is phenol (CGHOH) or meta-cresol. 11 A process as claimed in any of the preceding claims, wherein the etherifying agent is epichlorhydrin. 12 A process for the production of an etherified resin substantially as described in any of the foregoing examples. 13 Etherified resins when prepared by a process as claimed in any of the preceding claims. 14 A process for the production of cured resinous products which comprises heating a substantially dehydrated etherified resin as claimed in claim 13 in the presence therein of an= amino compound or a weak acid. A process for the production of fibre glass laminates which comprises impregnating fibre glass material with a substantially dehydrated etherified resin as claimed in claim 14 mixed with a curing catalyst and thereafter curing the resin. 16 Fibre glass laminates when prepared by a process as claimed in claim 15. washed once with water, neutralized with dilute acetic acid and then heated to 150 ' C. under 5 cm of mercury and finally filtered to remove any salt which had not been removed by washing 700 parts of an amber resin were obtained This contained 7 3 % epoxy oxygen and gave hard, tough products when cured with the usual catalysts.

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* GB785931 (A)

Description: GB785931 (A) ? 1957-11-06

Electrodeposition of bright nickel

Description of GB785931 (A)

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DE1042336 (B) FR1099302 (A) DE1118563 (B) FR70452 (E) DE1042336 (B) FR1099302 (A) DE1118563 (B) FR70452 (E) less 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 L K Date of Application and filing Complete Specification: Jan 15, 19 No 1206154. Application made in United States of America on July 17, 1953. Complete Specification Published: Nov 6, 1957. Index at acceptance: -Class 41, B 1 (R: T). International Classification:-C 23 b. COMPLETE SPECIFICATION Electrodeposition of Bright Nickel We, THE HARSHAW CHEMICAL COMPANY, a corporation organized and existing under the laws of the State of Ohio, United States of America, located at 1945, East 97th Street, Cleveland 6, State of 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:- This invention relates to electrodeposition of nickel and more specifically to a process of and solution for producing extremely bright deposits of nickel even on relatively rough surfaces, such deposits being bright and smooth without buffing or polishing of any sort. Since the electrodeposition of nickel in brilliant form began to be used extensively some 15 or 20 years ago, a great many solutions have been developed which are capable of yielding deposits of extreme brilliance. Some of these produce their optimum results only under relatively favorable conditions, some produce deposits of greater ductility than others, some produce bright deposits under a wider range of conditions such as p H and current density and still others are more tolerant to impurities. It is an object of the present invention to provide a high bright throwing power solution by the electrolysis of which between a nickel anode and a cathode there can be produced bright ductile deposits on relatively rough surfaces, that is, on surfaces of a roughness represented by an RMS of from 7 to 40 when the surface, before plating, is measured by means of a Brush surface analyzer It will be understood that the Brush surface analyzer gives a measure of the roughness of a surface in microinches average deviation of the microscopic irregularities from an average surface A further object is to provide such a solution which produces deposits of satisfactory ductility, excellent brightness, and which is resistant to impurities and can be run for long periods of time, adding from time to time the lPrice 3 s 6 d l constituents which are consumed or lost by drag-out. The foregoing and other objects are attained by the electrolysis between a nickel anode and a cathode of an aqueous acid solution of a nickel electrolyte of the class consisting of nickel sulphate, nickel chloride, and mixtures of nickel sulphate and nickel chloride, which solution contains at least three addition agents co-operating in imparting brightness to the deposit, one of said three addition agents being selected from the first, another from the second, and the third from the third class of addition agents set out below. The first class of addition agents consists of ethers of the form ROR 1 wherein R and R' are radicals of the formula CGHISO 2 NHSO 2 R 11, R being selected from phenyl, halogen substituted phenyl, tolyl, methyl, ethyl, propyl, and butyl, and of the compound (C O H 5 SO 2 NHSO 2 CH,),. The second class of addition agents consists of the naphthalene

sulphonic acids and their salts such as sodium, potassium, and nickel naphthalene sulphonates, all of which are herein referred to as naphthalene sulphonates. Among this class of addition agents the naphthalene disulphonates and mixtures thereof are preferred, for example 1,5-naphthalene disulphonic acid and 2,7-naphthalene disulphonic acid Mixtures principally consisting of the last two mentioned compounds may be prepared by reacting naphthalene with 200 oleum (i e. fuming sulphuric acid containing 100 parts by weight of 100 % sulphuric acid and 20 parts by weight of free SO',) at 160 C for two hours The proportions may be about two parts oleum for one part of naphthalene and the resulting mixtures may be neutralized with nickel carbonate When quantities of "sulphonated naphthalene" are specified herein, the nickel salt mixture produced by this reaction is intended, the naphthalene disulphonate content being given. The third class of addition agents consists 785,931 954. :: bd< A-U of amino polyaryl methanes and amino polyaryl (ammies, e g triamino triphenyl methane, diamino diphenyl methane, and triamino triphenyl amine, and compounds of the formula SCHOGCHOCH 2 CHS', wherein S and S' are selected from isoquinolinium and pyridinium radicals and are connected through the nitrogen atoms. A fourth class of addition agent utilized for prevention of pitting is optional and may be any one of numerous wetting agents, for example 7-ethyl 2-methyl undecanol 4-sulphate which gives excellent results Similar branch chain aliphatic sulphates having from 8-12 carbon atoms are also suitable It is to be understood that for some purposes the amount of pitting which is likely to occur in the absence of anti-pit agents can be tolerated, and that under some conditions pitting does not occur to an objectionable extent. Compounds of the first class mentioned above are preferably utilized in a Watts type nickel plating solution in concentration from 1 to 6 grams per litre, suitably 3 grams per litre Addition agents of the seceod class mentioned above are preferably utilized in connection with such concentration of the first mentioned class to the extent of from 1-6 Ni SO, 7 H 20 Ni Cl 2 6 H 20 Boric Acid HO to make Temperature PH Cathode current density 100-400, 10-60, 0-50, 1000 cc. grams per litre, suitably 2 grams per litre. Compounds of the third class are preferably utilized in conjunction with the first and second class of compounds in the above indicatei concentrations, to the extent of from 0.002 to 0 01 gram per litre, suitably 0 005 gram per litre If the wetting agent is used, it may be employed in conjunction with the foregoing at a concentration from 0 05 to 0 5 gram per litre. There may also be employed in conjunction with the first class of

addition agents ah_compound QIHISO 2 NHSO C,11 preferably in a concentration less than that of the addition agent of the first class. Processes for the preparation of the compounds (CHSO 2 NHSO 2 CHJL)2, (CGH 5 SO NNHSOOCH,),O and nuclear substituted derivatives thereof are disclosed in Patent No 753,728 and the other compounds of the first class of additives referred to above may be prepared in an analogous manner. The preferred basic solutions in connection with which the above described addition agents may be used in the concentrations indicated, may contain: preferably 200 to 300 g /l. preferably 25 to 40 g /l. preferably 15 to 40 g /l. 1000 F to 160 F, preferably 1200 F to 140 F. 3.5 to 5, preferably 4 0 to 4 5 to 60 amps /sq ft. 785,931 The following specific examples will serve to illustrate tle invention: Example Number 1 | 21 3 4 51 61 7 8 Ni SO 47 H 20 g /l 240 240 240 350 200 | 250 240 240 Ni C 12 6 H 20 g /l 40 30 401 50 40 40 40 40 HBO, g /l 40 30 40 50 30 40 40 40 7-ethyl 2-methyl undecanol 4-sulphate g /l 0 1 0 1 0 3 0 1 0 2 0 1 (C 6 H 5 SO 2 NHSO 2 C 6 H 4)20 g /l3 5 3 _ 5 (Cl C 6 H 4 SO 2 NHSO 2 CGH 4)20 g /l 2 _ _ _ _ (CH 3 C 6 H 4 SO 2 NHISO 2 C 6 H 4)20 g./1 _ _ _ _ 1 _ _ 2,7 naphthalene di-sulphonic acid g /l _ _ 1 O _ _ 2 1,5 naphthalene di-sulphonic acid g /l _ _ Sulphonated naphthalene g /l 2 5 2 _ 1 3 2 Triamino-triphenyl methane g /lO 005 O 005 O 005 0 002 O 003 O 003 (C 5 H 5 NCH 2 CH 2)20 g /l O 005 (C 9 H 7 NCH 2 CH 2)20 g/l 0 01 CHSO 2 NHSO 2 C 6 H, g /l 2 _ oc 6 ii 4 O a 2 N Ht SO,'41 S g /l 3 s Noa HS Oa C 4 H 9 _ _ (Ph S Oz NHSO 2 C 6 H 4)2 g /l _ 1 _ _ O 5 Temperature 'F 140 140 140 120 140 140 140 140 p H 4 0 4 0 4 0 3 5 4 5 4 0 4 0 4 0 Cathode current density amps /sqft 50 40 50 40 40 50 40 50 Water to make (litres) 1 1 1 1 1 1 1 1 CH CH C H;LOCH Ci N z O C Pi CH LC Hs Ltig OCH;LCH,0 & z Cc The compound Cfi HSO 2 NHSO 2 C 6 H 4 OC'H 4 SO 2 NHSO'C 4 H 1 may be replaced in Example 8 by the compound CGH So 2 NHSO'CI 4 00 C 6 H 45 ONHSO 2 ethyl or propyl. Furthermore triamino,triphenyl amine may be used in place of triamino triphenyl methane 10 in the examples.

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* 5.8.23.4; 93p

* GB785932 (A)

Description: GB785932 (A) ? 1957-11-06

An improved method of and apparatus for protecting the cathodes ofelectrolytic cells

Description of GB785932 (A)

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CH318436 (A) DE1046587 (B) US2834728 (A) CH318436 (A) DE1046587 (B) US2834728 (A) less Translate this text into Tooltip

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PATENT SPECIFICATION Date of Application and Filing Complete Specification: Mar 2, 1954. Application made in Italy on Mar 2, 1953. 7855932No 61 G 5154. Application made in Italy on Dec 19, 1953. Complete Specification Published: Nov 6, 1957. Index at Acceptance:-Classes 38 ( 5), BIG 4, B 2 C( 3 6 D: 8 B); and 41, A(C: 2 C 3: 9). International Classification:-C 23 b H 02 c. COMPLETE SPECIFICATION An improved method of and apparatus for Protecting the Cathodes of Electrolytic Cells. We, OROINZ Io DE NORA IMPIANTI ELETTROCHIMICI, of Via Arqua 15, Milan, Italy, an Italian Company, 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 method of and apparatus for protecting the cathode of an electrolytic cell in a series from attack by the electrolyte and electrolysis product during periods when the cell is cut out of the main electrolysis circuit. The invention is hereinafter described, by way of example, with reference to amalgam cells for the electrolysis of alkali chlorides, wherein the cathode consists of a flowing layer of mercury or of an amalgamated metallic surface It is however to be understood that the invention may be applied to other types of electrolytic cells than those hereinafter specifically described. In order to shut down a cell in a bank oi electrolytic chlorine cells, for example, and keep the other cells in operation, the normal practice, up to the present time, has been to short-circuit the cell to be shut down, by connecting the anode and cathode by an external conductor This procedure is objectionable because, during such period of inoperation, the cathode of the cell is exposed to chemical attack by the free chlorine dissolved in the brine remaining in the cell and is thus turned into the anode of a shortcircuited galvanic battery and, as a consequence, the attack on the mercury in the cell is increased by the concommittant electro-chemical process which takes place within the short-circuited cell in the presence of the dechlorinated brine. One means for overcoming this objection is described and illustrated in United States Specification No 2,508,523, concerning the installation of a number of auxiliary protective anodes in the cell which form, with the cathode, a circuit independent of the main anodes when the cell is cut out of the main electrolysis circuit The apparatus described in the said United States specifi 50 cation is used for producing the electrolytic decomposition of an alkaline chloride and comprises a plurality of electrolytic cells connected in series each including cathode means, main anode means, auxiliary anode 55 means, a main current supply means for said apparatus, an auxiliary relatively low current supply means for said apparatus, means for connecting said cathode and said main anode means in series with each other and 60 ' with said main current supply means whereby relatively high current may flow through said cells producing therein said electrolytic decomposition, means for short circuiting said cathode and said main anode means 6 g individually in each cell, and means for individually connecting said cathode and said auxiliary anode means individually in each cell with said auxiliary current supply means whereby a relatively low current 70 ' may be circulated through each

of said cells, producing therein substantially no electrolytic decomposition, whereby it is possible to stop operation of any of said cells severally or in combination in said ap 75 paratus while maintaining a flow of relatively low non-electrolysing current through each of said non-operating cells. The method suggested in the said specification has several disadvantages The in 80 stallation of the additional auxiliary anodes involves a complication in the design and construction of the cell In addition, as there is a very limited space left free around the main anodes, in which the auxiliary 85 anodes may be located, the polarising current cannot be uniformly distributed over the cathode Furthermore while the cathode and the auxiliary anodes are connected in a cell, the cathode and the main anodes 9 % 785,932 are short-circuited and, in order to maintain the polarising current, an additional amount of current must be dissipated through the main anodes In other words part of the current flowing from the auxiliary anodes is shunted through the main anodes, thus having no protective effect at all over the cathode Finally, due to the small dimensions of the auxiliary anodes, even though 10the polarising current is kept at the lowest value which can still protect the cell, its amount, plus that which is dissipated through the main anodes, requires a rather high current density over the auxiliary anodes so that their potential can go as high as the chlorine discharge point which involves potential danger to the inactive cell. All these disadvantages are overcome by the present invention. One of the objects of the invention is to provide means for disconnecting out of the electrolysis circuit of a group of cells in series, one or more cells individually without need for the disconnected cell or cells to remain short-circuited, while the other cells are being kept on load. Another object of the invention is to provide means by which an electrolytic cell may be cut out of the electrolysis circuit and the anodes may be used also as protective anodes during the period of inactivity of the cell. A still further object is to provide means by which, in case of interruption of the electrolysis current, whether intentional or accidental, a nolarising voltage is automatically applied between the anode and cathode of the disconnected cell or cells so as to protect the cathode or cathodes of said cell or cells. The invention consists in a method of protecting the cathode of an electrolytic cell during the disconnection of said cell out of a group of cells connected in series, by breaking the electric continuity between the anode thereof and the cathode of the nearby upstream cell, with respect to the direction of the electrolysis current and

connecting instead the cathode of the cell to be disconnected with the cathode of the nearby upstream cell, so that the electric continuity of the other cells in the circuit will be maintained, while such continuity is completely interrupted between the anode and cathode of the disconnected cell. Preferably a cathodic protection is applied to the cathode of the disconnected cell by establishing between the anode and cathode thereof a polarizing voltage from an auxiliarv power source. The invention further consists in means for protecting the cathode of an electrolytic cell in a bank of cells connected in series. when the cell is disconnected, comprising a cathode bus bar leading from the nearby upstream cell, with respect to the direction of the electrolysis current, a second bus bar leading to the anode of the cell to be disconnected, and a third bus bar leading to the cathode of the cell to be disconnected 70 a rotary contact member adapted in one position to make contact with all of said bars and in another position to contact two of said bars, and means to rotate said contact member so that it will make contact 75 between the first and third of said bus bars before it has broken contact with the second of said bus bars. In a preferred embodiment of the cathode protecting means according to the invention 80 a shaft operating the rotary contact member is provided with an auxiliary contact whereby a source of polarizing current is connected between the anode and cathode of the electrolytic cell when the electrolysis 85 current to said cell is cut off. Referring to the accompanying drawings which illustrate a preferred form of embodiment of the invention: Fig 1 is a diagrammatic illustration of a 90 pair of electrolytic mercury cells to which the invention has been applied; Fig 2 is a part sectional end view of a switching means for use in de-energizine a cell without short-circuiting it, accordin 2 ito 95 one of the objects of the invention: Fig 3 is a side view of the switch illustrated in Fig 2, taken from the right of Fig 2; Fig 4 is a sectional view of the switch 100 illustrated in Fig 3, taken along the line 4-4 of Fig 3, Fig 5 is a part sectional view taken along the line 5-5 of Fig 4: and Fig 6 is a detailed view showing the 105 switch in one of its positions. Referring to Fig 1, 1 and 2 are two amalgam cells in which the mercury cathode flows along'the sloped bottom of the cells and the electrolysis current, during operation 110 of the cell, flows between the anode means A and the cathode B Brine is circulated between the anode means and the cathode and for the production of chlorine and caustic soda it is decomposed into chlorine and 115 sodium, which later is amalgamated with the mercury flowing along the bottom of the

cells I and 2. In the embodiment illustrated, the cell l is represented in the process of being cut 120 out of the main electrolysis circuit, while the cell 2 is shown in the main electrolysis line. The cell I or any other cell in the electrolysis circuit may be cut out of the circuit by disconnecting the negative bus bar 3 coming 125 from an upstream cell in the row, from the positive bus bar 4 of the cell l to be cut out of operation, while the following cell 2 remains connected through the negative bus bar 3 ' of the cell 1 (which has a portion 7)130 785,932 and the positixe bus bar 4 ' of the cell 2, so that the electrolysis current is carried through the bus bar 3, switch member 5, rus bar 3 ' of cell 1 and bus bar 4 ' of cell 52 to the cell 2, while the cell I is cut out of the circuit The negative bus bar of the -ell 2 has a portion 7 ' corresponding to the portion 7 of the negative bus bar 3 ' of the cell 1 The switch members 5, which may l Obe constructed as shown in detail in Figs. 2 to 6, are operated by means of a switch handle 6 and switch bar 8 to move the switch element 5 to the position to disconnect the cell 1 from the circuit or with reference to cell 2, to either include the cell in the circuit or to disconnect it therefrom. In Fig 1, the switch member 5 is illustrated in an intermediate position with respect to the cell l, in which the switch 720 member is passing from a position where it connects bus bar 3 with bar 4 to a position where this connection is broken and connection is established between the bar 3 and and portion 7 of the bar 3 ' The switch element 5 is so constructed that when a cell is being cut into or out of the circuit, the electrical connection between the bus bar 3 and the portion 7 will be established before the connection between the bar 3 and the bar 4 is broken, and vice versa. In addition to the switching means for switching a cell into or out of the electrolysis circuit, means are provided for simultaneouslv applying a protective polarising voltage between the anode means A and the mercury layer constituting the cathode B. For this purpose, the switch bar 8 is provided with an auxiliary contact member 9 which is constructed to make contact with 40the contacts 9 a and 9 b as soon as the cell is cut out of the main circuit to connect the anode means A and cathodes B with the positive and negative pole respectively of a source of polarising voltage 10. A ballast resistor 11 is oreferably inserted in the polarising circuit in order to protect the source of voltage 10 from damaging current surges, which might arise if the source were connected without ballast to a cell f O which had not yet acquired or had lost its polarising conditions. The Dolarisine source of voltage 10, which is provided for each cell,

preferably consists of a battery of very small capacity and a trickle charge system 12 fed by alternmting current, so that the source 10 is maintained at the desired potential However, any suitable source of polarising voltage may be used. In order to ensure immediate protection of the mercury cathodes in case of a ternporary failure of the main or electrolysis circuit under operating conditions an auxiliary contact 13 may also be provided on the M 5 main circuit breaker (not shown) which will close automatically when the main circuit breaker opens The auxiliary contact 13 is normally closed when the main circuit breaker is opened either by manual control or as a consequence of a power failure, 70 which causes the automatic devices embodied in the circuit breaker to trip out Through the closing of the contact 13 an exciting current will be sent to the relay 14, which is provided in each polarising circuit, so 75 that the relay will close the polarising circuit, upon any failure of the electrolysis power, even when the switch 5 which disconnects the cell is closed and the auxiliary contact 9 is in open position, as illustrated 80 in connection with the cell 2. In the operation of the invention, as illustrated in Fig 1, if it is desired to cut the cell I out of the circuit, the switch handle 6 is moved in a clockwise direction to move 85 the contact switch member 5 from the position in which it makes contact between the bus bar 3 and the positive bar 4 to the position in which the member 5 is out of contact with the bar 4 but is in contact with 90 the portion 7, leading to the next cell The contact between the bar 3 and the bar 4 is not broken until the contact between the bar 3 and the portion 7 has been made At the same time the switch bar 8 moves the 95 contact member 9 into contact with contacts 9 a and 9 b to complete the polarising circuit from the positive side of the source 10 to the anode means A and from the negative side thereof to the cathode B, so that the 100 polarising voltage is immediately applied to the cell which is cut out of the circuit. The illustrations in Fig 1 are purely diagrammatic and the insulation, part of the wiring and other parts, not essential to the 105 understanding of the invention, have been omitted so as not to unduly complicate the drawings. When a current failure occurs while a cell is in operation, the circuit between the 110 source 10 and the anode means A and cathode B is completed by the closing of the contacts of the relay 14, which is operated automatically by the contact 13 on any failure or break in the power line of the elec 115 trolysis circuit. In addition to the obvious advantages attained by the above described arrangement another very important advantage is that the protection of the cell is effected through 120 the same anode means of large

dimension which serve for the electrolysis process, so that the polarising current is uniformly distributed over the entire cathode, and, therefore, a small current is sufficient to 125 ensure protection of the cathode We have found that by the above arrangement, a cathodic current density as low as 0 15 amps /sq ft is sufficient to provide the desired protection 130 785,932 Inasmuch as the anode surface area is nearly the same as the cathode area, the anodic current density will also be nearly the same as the cathodic current density Using 5the above stated value of 0 15 amps /sq ft, the voltage difference at the cell terminals amounts to about 1 volt, so that the anode potential is much lower than the chlorine discharge potential It is therefore unnecesl Osary to provide means for neutralizing any possible evolution of chlorine gas, as is required when using auxiliary anodes of small dimensions. Another advantage which arises from keeping the polarising voltage at a very low value resides in the fact that under the above stated conditions, polarisation is sufficient to protect the mercury from the attack by chlorine, but not the iron suspension that sometimes accumulates in mercury and is often a cause of serious troubles The small polarising current will protect the mercury. but will allow its iron content to be set free and eo into solution as chloride. While any suitable switch element 5 adapted to make contact between the two bus bars to be connected before the contact between the two bars to be disconnected is broken may be used we have found the switch illustrated in Figs 2 to 6 to be particularly well adapted for this purpose This sw.xitch consists of the contact members 5 mounted on the switch bar 8 and adapted to make or break contact between the bars 3 4 and 7 corresponding to the bars illustrated diagrammatically in Fig 1. Contact members 33, 44 and 77 are connected to the bars 3, 4 and 7, respectively, and are supported by a U-shaped bracket 1, to which the contact members 33, 44 and 77 are connected at 22, 23 and 24 respectively, suitable insulation being jrovided at these connections, as indicated more particularly in Fig 4, so that electrical contact between the contact bars 33, 44 and 77 will be made only through the sw vitch members A spring member 25 which passes through the contact bars 44 and 77, presses against the blocks 30 to maintain the contact bars 44 and 77 in their desired position and in contact with the switch members 5 when contact is to be made with the switch members 5 The bracket 21 is also provided wk-ith lower bearing members 34 and a removable cap bearing member 35 so as to provide a journal through which the shaft 8 extends and in which bearings the shaft 8 may be rotated to control the position of the switch members 5. The position of the switch members 5 is chianged by the rotation of

the shaft 8. which is connected throuah:ev 26 to switch members 5 in such a way as to allow slieht radial play for the switch members 5. The'shaft 8 is provided with two collars 27, which are rigidly fixed to the shaft, and which support two rods 28, which are parallel to the shaft 8 and push against springs 29, through pressing plates 32 Springs 29 bear on the ends of the switch members 5 70 through pressing plates 31 formed as inverted U-shaped members, which also guide the springs 29 The springs 29 are, therefore, compressed between the rods 28 and the switch members 5, so that the switch 75 members will be permanently pushed against the ends of the contact bars 33, 44 or 77. depending upon the position to which the switch members 5 are rotated Separate springs 29 are provided at each end of each 80 switch member 5 so that the individual switch members may automatically adjust their position with respect to the contact bars 33, 44 and 77. Movement of the switch members by turn 85 ing the shaft 8 causes the switch members to slide over the ends of the contacts 33, 44 and 77 to make or break the contact. The switch members 5 are preferably made of a silver alloy or of any other metal patr 90 ticularly suitable for electrical contacts, and the switch members 5 are preferably multiple, as indicated in Figs 3 and 5, so as to provide a plurality of contact points ala ensure grood contacts between the switch 95 members and the contact bars 33 44 or 77 at all times The contact bars 33 44 and 77, which are usually made of copper may have their ends silver plated or may ha Ve a suitable contact alloy brazed to their ends 100 The operation of the switch members 5 will be readily understood from the above description When the control shaft 8 is turned to switch in" position, for a particular cell, the switch members 5 will be 105 pressed against the bars 44 and 33, so that the electrolysis current will be led by the contact 44 and anode bar 4 to the anode of this ceil and after passing through the cell, will be conducted through the cathode 110 bar 3 ', connected across the base of the cell to the next adjacent cell When it is desired to cut a cell out of the electrolysis circuit, the shaft 8 will be rotated so that the switch menmbers 5 will be turned to connect the 15 contact 33 with contact 77 and to disconnect contact 44 from contact 33 During both the "'switching in" and "switching out" operations the switch members 5 will temporarily pass through an intermediate position, as 120 indicated in Figs 1, 2 and 4, in which position the switch members 5 will contact all of the three contact bars 33, 44 and 77 so that there will be no interruption in the continuity of the circuit to the cells remaining 125 therein as the switch' members 5 move from one position to another.

This intermediate position of the switch members 5 will corresnond to a momentary short-circuiting condition for the cell being 130 of the disconnected cell.

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* GB785933 (A)

Description: GB785933 (A) ? 1957-11-06

Process for the preparation of fatty acid esters suitable for use asointment bases and the like carrier media

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COMPLETE SPECIFICATION Process for the preparation of Fatty Acid Esters suitable for use as Ointment Bases and the like Carrier Media We, EDELFETTWERRE G.M.s.H., a German company, of 202, Schnackenburgallee, Hamburg-Eidelstedt, Germany, 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 preparation of ointment

bases and the like carrier media. Cocoa butter has long been used for suppository masses because it melts below the bddy temperature, because the solidifying point lies only a little below the melting point, and because cocoa butter does not irritate the mucuous membranes. However cocoa butter masses have the following disadvantages: they are relatively difficultly resorbable and hinder the activity of the medicaments, they have only a small absorbent power for aqueous liquids, they sweat out at summer temperatures or in the tropics, and become rancid, and above all, on heating unstable p forms are formed, so that the solid medicament particles are deposited and therefore often produce undesired side actions. It has therefore long been sought to replace cocoa butter and it has been proposed to use triglycerides of similar melting point, such as hardened ground nut oil, palm kernal oil, stearin, or other fats. There have been added to cocoa butter, fats, waxes, or emulsifiers such as lecithin or cholesterol, and fat-wax-oil mix tures have been suggested, but these products have not been used in practice. In order to increase the capacity of the masses for carrying medicaments and the stability on storage, gelatine and glycerine masses have been used as well as water soluble polymerisation proS ducts of ethylene oxide, and ir has also been recommended to use those fatty acid esters of glycerine or glycol, such as the stearic ester of propylene glycol, which melt in the region of 37 C. Since these however have the known disadvantages of the triglycerides there have been added to them, emulsifying agents such as stearates, palpitates or oleates of amines, or alkali soaps. Products obtained by splitting natural fats or oils, hydrogenation of the fatty acid mixtures thereby obtained and esterifica- tion of the hydrogenated product with an excess of glycerine, have also been proposed already as ointment bases, or suppository masses (see particularly British Patent Specification 694,97u). However none of these products has been able to replace cocoa butter, and therefore they have attained no great practical importance. The present invention relates to a process for the manufacture of fatty acid esters suitable for use as ointment bases, suppository masses and the. like carrier media by esterification of saturated fatty acids with an excess of a polyhydric alcohol, e.g. glycerine, characterised in that two or more different fatty acids having an iodine number of less than 5 and having 12 to 18 carbon atoms per

molecule are ester fied with an excess of the polyhydric alcohol, the relative amounts of the fatty acids and the alcohol, and the number and kind of the fatty acids being so chosen that there are obtained mixtures of partial esters of these two or more fatty acids containing free OH groups, with complete esters of these two or more fatty acids which mixtures have a melting point of less than 40 C., preferably of 33 to 37 C. The term " two or more different fatty acids " excludes fatty acid mixtures in which the fatty acids are present in a quantitative proportion corresponding substantially to fatty acid compositions derived from natural oils and fats. The method of working according to the invention renders it possible, by choosing the amount and nature of the mixed fatty acids, to determine beforehand the melting point of the end product whereas this is not possible when using fatty acid mixtures obtained by splitting natural fats and oils due to the varying composition of such mixtures. As starting material for the manufacture of the ester mixtures prepared according to the invention, saturated fatty acids such as in particular lauric acid, myristic acid, palmitic acid or stearic acid can be used. It is essential that the fatty acids be either saturated, or so nearly saturated that their iodine number amounts to less than 5. These fatty acids are esterified with polyhydric alcohols such as g]ycols, e.g. ethylene glycol, propylene glycol, trimethylene glycol, 1,2-dimethyl ethylene glycol, thio glycols, or glycerol, erythritol, pentaerythritol and mannitol. The esterification according to the invention must be so carried out that partial estercomplete ester mixtures are obtained which have free hydroxyl groups. In the following examples, 1 to 4 the esterification of the fatty acid mixtures is effected with excess glycerine at temperatures from 1200 to a maximum of 200 C. and at a pressure of from 36 mm. of mercury using zinc dust as catalyst. EXAMPLE 1. A mixture of 60 parts by weight lauric acid having an iodine number about 1, and 40 parts by weight of stearic acid having an iodine number less than 5, are esterified with 14.8 parts by weight of glycerol as above. The product obtained is hard, brittle, contains free hydroxyl groups and melts at a temperature of 35--37" G which makes it suitable for uvular masses and globuli. EXAMPLE 2. 300 parts by weight of lauric acid, and 200 parts by weight of myristic acid in admixture are esterified with 83.5 parts by weight of glycerine as above so that partial esters are produced which still

contain free hydroxyl groups. The hard brittle product which is obtained melts at about 33 C. EXAMPLE 3. 250 parts by weight of lauric acid, and 250 parts by weight of myristic acid in admixture are esterified with 83.5 parts by weight of glycerine as above so that partial esters are produced which still contain free hydroxyl groups. The hard brittle product which is obtained melts at about 36 C. Particularly finely crystalline and uniformly melting products with a small interval between softening and melting points, are obtained it first of all one of the fatty acids is esterified so as to convert part thereof to mono glyceride and after the expiry of about two hours of esterification, the remaining fatty acid is added to the reaction mixture, and esterification is continued to form the desired partial ester and full ester mixture. EXAMPLE 4. 350 parts by weight of myristic acid, and 150 parts by weight of lauric acid in admix ture are esterified with 83.5 parts by weight of glycerine as above so that partial esters are produced which contain free hydroxyl groups. Aftr deodorization and refining has been effected there is produced a hard brittle pro duct which melts at 39.5 C. In this example also the products obtained are particularly finely crystalline uniformly melting products with a small interval between the softening and melting points. The pro ducts are particularly suitable for raising the melting point of coconut fat. If the product is mixed in a ratio of 1-: 1 with coconut fat, there is obtained a product, melting at about 3W 35 C., which is far above the melting point of pure coconut fat. The product is particu larly suited for working up in the confec tionary trade. Instead of myristic acid, palmitic acid in similar ratio as in Examples 2, 3 or 4 may also be used. EXAMPLE 5. 375 g. stearic acid having a melting point of 67" C. and an iodine number below 3, 125 g. palmitic acid, melting point 57" C.

iodine number 1, 95 g. 1,2-dimethyl ethylene glycol (2,3 butylene glycol) and 2 g. zinc dust are esterified in a vacuum or under a stream of carbon dioxide. The esteri fled product obtained is refined, washed and if necessary deodorized. A brittle, hard product is obtained having a melting point of 33 C. and a hydroxylnumber of 30. The product is especially suitable for making suppository masses. The products obtained by the process according to the invention can be used as oint ment bases for the manufacture of supposi tories, vaginal spheres and for other pharma ceutical purposes, for the manufacture of stable emulsions, or for food-stuff purposes, e.g. the manufacture of chocolate goods, baked goods, food fats, and mayonnaisses. What we claim is: 1. Process for the manufacture of fatty acid esters suitable for use as ointment bases, sup pository masses and the like carrier media by esterification of saturated fatty acids with an excess of a polyhydric alcohol, e.g. glycerine, characterised in that two or more different fatty acids, as hereinbefore defined, having an iodine number of less than 5 and having 12 to 18 carbon atoms per molecule are esterified with an excess of the polyhydric alcohol, the relative amounts of the fatty acids and the alcohol, and the number and kind of the fatty