5566 5570.output

* GB785974 (A)

Description: GB785974 (A) ? 1957-11-06

Refining of fluorocarbons

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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.

COMPLETE SPECIFICATION Refining of Fluorocarbons We, UNITED KINGDOM ATOMIC ENERGY AUTHORITY, of London, a British Authority, do hereby declare the nature ot this invention and in what manner the same is to be per formed, to be particularly described and ascertained in and by the following statement: This invention relares to the manufacture of fluorocarbon compositions and is particularly concerned with a method for refining or finnish ing such compositions to improve their stability. In the past it has been proposed to fluorinate hydrocarbons by several different methods, all involving a fluorination of the-hydrocarbons in an extended physical state, either as vapors or as (dilute liquids. For instance it bas been proposed to pass lubricating oil vapors, diluted with an inert gas such as nitrogen or hydrogen fluoride, to maintain reactants and reaction products in vapor phase, into contact with a silver catalyst, and as the same time to introduce into the mixture elemental fluorine to effect the fluorination. It has also been proposed to pass a mixture of vapors of a suitable high-boiling oil and a diluent into contact

with a fluorinating agent such as silver difluoride, cobalt trifluoride, or manganese trifluoride. A somewhat similar result can be achieved by means of reduced pressure. Thus by maintaining a sufficient vacuum on the distillation and the reaction vessels, the materials employed can be maintained in the extended physical state required by the reaction. Th each of the fluorination processes outlined above, a product is obtained having 75 % or more of the hydrogen initially present replaced by fluorine. However the products are not as stable as desirable for many purposes and act as reducing agents UPon certain highly reactive materials and in some cases may contain highly toxic substances. While it has been proposed to refine such products by passage into contact with elemental fluorine in contact with a fluorination catalyst in a second pass, such an operation entails large losses of valuable high-boiling fluorocarbons. It is an object of the present invention to stabilize fluorination products and to eliminate their reducing properties and remove toxic substances. A further objet is to accomplish these purposes in a more economical manner and with less loss of high-boiling fluorocarbons than hitherto possible. In accordance with the process of the present invention we subject fluorocarbon products oft the type produced by any of the processes outlined above, to a finishing treatment in liquid phase with silver difluoride (AgF2), cobalt trifluoride (CoF,), or manganese trifluoride (MnF3) employing the fluorinated product in a concentrated form. The finishing treatment of our invention may be conXcted at temperatures between 200 C. and 400 C. It can be carried out in any suitable equipment such as a closed iron or steel kettle or autoclave provided with an agitator, but it is preferred to employ equiptment of more resistant materials of construction such as nickel. The products of our process are highly stable high-boiling fluorocarbons, which are particularly resistant to active oxidizing agents and therefore are useful wherever a very stable high-boiling fluorocarbon product is required. The invention is particularly applicable to the production of liquids of low vapor pressure suitable for use as lubricants, sealants, etc., where a high degree of stability, especially toward oxidizing agents, is essential or desirable. The following examples will serve to illustrate the invention: EXAMPLE 1. By the catalytic vapor phase fluorination of a lubricant oil fraction of petroleum by means of elemental fluorine diluted with nitrogen, and distillation from the product of oils boiling below 170 C. at one half

atrnosphere absolute pressure, 68 pounds elf a crude high boiling fluorocarbon residue were obtained, having an average molecular formula of about C2sHloF42. (If a product of this type is refined by a second treatment with elemental fluorine, about 10% or more is lost by degradation and the valuable 147 to 208 C. (at 10 mm absolute pressure) fraction is correspondingly small, amounting to 20 pounds or less fram 68 pounds of crude.) The 68 pounds of crude product were charged to a 6 gallon dosed nickel kettle provided with a nickel agitator and with a temperature-controlled jacket 7 pounds of CoF3 were added, and the agitated mixture was heated gradually to 255 C. in a period of about 3 hours. Hydrogen fluoride formed during this period was bled from the kettle to avoid substantial pressure increase. Heating was continued at a temperature between 200 and 225 C. until the rate of evolution df hydrogen fluoride was less than 0.01 grams per hour. The aharge was then cooled to 150 C., and the solid inorganic products were allowed to settle. After the inorganic material had settled, a blow leg was inserted to within -t- inch of the precipitate, the pressure was applied to the vessel to blow the clear fluorocarbon into a steamheated filter at a pressure of about 10 pounds per square inch above atmospheric. The filter comprised a w inch layer of diatomaceous earth sandwiched between two layers of cloth. About 67 pounds of fluorocarbon product were obtained as filtrate. The filtrate was fractionally distilled and a cut boiling between 147 C. at 10 mm. of mercury absolute pressure and 208 C. at the same pressure and amounting to about 24 pounds was collected as the final product. This product was a very stable non-toxic fluorocarbon product suitable for use as a fluorocarbon lubricant oil. EXAMPLE 2. 225 pounds of a crude high-boiling fluorocarbon product, obtained by fluorinating a high-boiling lubricant oil ifraction of petroleum by means of silver difluoride at temperatures of 150 C. to 240 C. in a high-boiling fluorocarbon solvent, separating the product by filtration to remove inorganic fluorides, and distilling off from the filtrate the solvent and other oils boiling below 140 C. at 10 mm d mercury absolute pressure, are charged to a closed 50 gallon nickel kettle provided with an agitator and a jacket for temperature control. The agitator is started and 225 pounds of silver difluoride are charged while the kettle is maintained at a temperature between 80" C. and 90 C. After charging is completed, the kettle is closed except for a vent connected with a condenser for recovering evolved hydrogen fluoride. The kettle is then heated gradually to about 210 C. in 4 hours and held at this temperature for 15 minutes. It is then cooled

to 100 C. and 225 pounds of silver difluoride are added. Tlie temperature is raised gradually to 240 C. in about 4 hours, and the charge is maintained at this temperature for about 10 hours. The kettle is cooled to 25--30" C., 283 pounds of trifluorotrichlorethane are added to increase the fluidity of the reaction mass, and the mixture is stirred for L hour. The charge is blown through a pressure filter as in Example 1 and the kettle is rinsed with additional trifluorotrichiorethane which is passed through the filter and is mixed with the total product until 600 pounds of the solvent have been used. The combined filtrate is passed to a still and fractionally distilled to separate the trifiuorotrichlorethane as distillate. The distil latin residue is then topped to 100" C. at 10 mm of mercury absolute pressure. The residue is returned to the 50 gallon kettle. 45 pounds of CoF, are added and the mixture is heated as before to a temperature of 275 C. in about 4 hours and held at this temperature for an additional 4 hours. It is then cooled to 80" C., an additional 45 pounds of CoF. are added, and the mixture is heated to a temperature of 275 C. for 4 hours and held at this temperature for 4 hours longer. The product is next cooled to 100" C. and 22 pounds each of CoF, and AgF2 are added The mixture is then heated to 275 C. in a period of 1 to 2 hours and held at this temperature for 4 hours. It is finally cooled, diluted with 83 pounds of trifluorotrichiorethane, stirred for 2 hour and blown through a filter as previously described. The kettle is again rinsed with an additional 317 pounds of trifluorotrichlorethane which is blown through the filter into the receiver with the fluorocarbon product The trifluorotrichlorethane is distilled off and the product is distilled in vacuum, the oil distilling above 147 C. at 10 mm. of mercury being collected as the final product. It is a very stable high-boiling liquid, remarkably inert to oxidizing agents. In order to insure a stable product, care should be taken to provide an ample quantity of the fluorinating agent. The product may be tested before the separation of inorganic material to determine whether the fluorination agent was completely used up or is substantial excess. If the former, additional reagent should be added and the process repeated. Having now particularly described and ascertained the nature of the said invention, and in what manner the same is to be performed, we declare that what we claim is: 1. A process for refining a crude fluorinated hydrocarbon which comprises contacting the crude fluorinated hydrocarbon in the liquid

phase at an elevated temperature with silver difluoride, cobalt trifluoride or manganese trifluoride. 2. A process as claimed in claim 1 wherein

* GB785975 (A)

Description: GB785975 (A) ? 1957-11-06

Basically substituted carboxylic acid amides and a process for making them




COMPLET SPECIFICATION Basically Substituted Carboxylic Acid Amides and a process for making them We, FARBWERKE HOECHST AKTIENGESELLschm, vormalls Meister Lucius & Brilningi a body corporate recognised under German law, of Frankfurt(M)-Hochst, 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 dlesc ; ribed in and by the follgw- ing statement: Basically substituted acetanilides are known to be good anaesthetics. #-Diethylamino-3- carbomethoxy-4 - hydroxy - acetanilide, described, for example, in Britisch Specification No. 22106/98, exhibits good therapeutic properties ; it has, however, a highly irritating effect. Lofgren has produced a large number of substituted acetanilides, among which #-diethylamino-2 : 6-dimlethylacetanilide exhibits the best anaesthetic properties and is, therefore, of importance in practice (d. Lofgren, Studies on Local Anaesthetics, Xylocainie (Registered Trade Mark),

Stockholm, 1948). The present invention is based on the observation that quite generally basically substituted carboxylic acid amides possess valuable therapeutic proprerties, which correspond to the general formula <img class="EMIRef" id="026415667-00010001" /> in which R represents alkyl radicals having 3 or 4 carbon atoms and Hal represents halogen, and the salts of these compound ; the compounds of the general formula <img class="EMIRef" id="026415667-00010002" /> in which Hal has the meaning given above, and in which R represents an alkyl radical having 3 or 4 carbon atoms being excluded. Thei invention also inclues a process for making the specified new compounds which comprises acetylating a corresponding derivative of 1-aminobenzene, containing as substituents in the phenyl nucteus the methyl radical and a h ; $logen atom wii an aminoacetic acid and containing in the amino group an alkyl radical having 3 or 4 carbon atoms or a derivative thereof, such as halides, esters, anhydrides) amides or lazides. The invention also includes a process which comprises first acetylating a corresponding deprivative of l-aminobenzeneJ contaTimng as substituents in the phenyl nucleus the methyl radicaq and a halogen atom, with a Eadogen- acetic acid and then condensing the halogenacetylamide so obtained with a primary amine in the smino group an alkyl radicall having 3 or 4 carbon at-zms. As aminobenzene derivatives by the methyl radical and a halogen atom there may be mentioned, for example, 1-amino-2-methyl-3chlorobenzene, 1-amino-2-methyl - 4-chlorobenzene, 1-amino-2-methyl-5-chlorobenzene, 1-amino-3-methyl-2-chlorobenzene, 1-amino3-mleiyl-4-chlorobenzene, 1-=uno-3-methyl- 5-chlorobenzene, 1-amino-3-methyl-6-chlorobenzene, 1-amino-4-methyl-2-chlorobenzene, 1-amino-4-methyl-3-chlorobenzene. The corresponding bromo compound may be substituted for the chloro compiounds named above. As aliphatic amio-acetic acids there may be used, for example, isopropylaminoacetic acid and n-butylaminoacetic ! acid. As aliphatic halogen-carboxylic acids Ithee may be mentioned, for example, chloracetic acid and the correspending bromo or iodo compound. Thc acetylation may be aarried out in known manner. It is advantageous to use for this purpose the derivatives of the amino-acetic acids or halogen-acetic acids such as halides, esters, anhydrides, amides or azides. Useful primary amines are, for exampEle, propylamine, n-butylamine, and 1sobutyl- amine. The reaction proceeds, for example, according to the following scheme

: <img class="EMIRef" id="026415667-00020001" /> The reaction of the aminomethyl-halogen benzenes with the derivatives of halogen-acetic acids is advantageously carried out in a solvent. As solvents there may bz used, for example, aliphatic or aromatic hydiocarbons, such as petroleum ether, ligroin, methyl-cyclohexane, benzene, tdluene or xyiene, or chlorinated hydrocarbons, such as methylene chloride, chloroform, carbon tetrachloride and cblor, obenzene. Moreover, glacial acetic acid may also be used. The hydrogen halide set free during the reaction of an aminomethylhalogen - benzene with a halogen-acetyl halide may be bound by the addition of a corresponding excess of amino-methyl-halogen-benzene. When working in a solvent miscible with water, another agent capable of binding minerval acid may be added, for example sodium hydroxide solution or sodium acetate. When the reaction is carried out, for example, in an inert hydrocarbon or chlorinated hydrocarbon, the hydrogen halide may be expelled by heat. The react. on of the halogen-acetylaminomethyl-halogen-benzenes formed with the primary amines can be carried out in the presence or absence of inert solvents at room temperature or at a raised temperature. The compounds of the invention possess excellent anaesthetic properties. Mention should especially be made of the compounds which are derived from n-butylamino-acetic acids. They are especially glood conduction anaesthetics showing at least the same effective strength as the #-diethylamino-2 : 6-dimethylacetanilide from which they are advantageously distinguished by their lower toxicity owing to their high pirate of de-toxication when injecte subcutaneously. The following Examples illustrate the invention : EXAMPLE 1. (a) 71 grams of 1-amino-2-methyl-3-chlorobenzene are dissolved in 600 cc. of benzene and the solution obtained is mixed with a solution of 28 grams of chlor-acetyl chloride in 150 cc. of benzene. After the mixture has been allowed to stand for 24 hours, water is added and, if a precipitate is present, the mixture is keated on a steam bath untel dissolution i9 complere. The aqueous liquid is separated and the benzene solution is evaporated to dryness. The benzene residue is recrystallised from cyclohexane. The resulting 1-(chloracetylamino)-2-methyl-3-chllorobenzene melts at 132 C. (b) 80 cc. of n-butylamine are poured onto 20 grams of the 1-(chloracetylamino)-2-methyl3-chlorobenzene thus obtained. After the hale hais been allowed to stand for 24 to 48 hours, the excess of butylamine is eliminated by distilation and the residue is taken up in ether and eilute sodium carbonate solution.

The etheral solution is separated and the ether is distilled off. The residue is dissolved lin alcohol and the solution obtained is transformed into the hydrochloride bu the addition of alcohalic hydrochloric acid. The 1- (butvl- am no-acetylamino)-2-methyl-3-chlorobenzene hydrochtloridle obrained in a good yield malts at 117 C.-119 C. ExAmPLE 2. (a) 18.6 grams of 1-amino-2-methyl-4bremobenzene are dissolved in 75 cc. of glacial acetic aad, 13 grams of chloracetyl chloride are added and separation of crystals and evolut on of heat are observed. After the further addition which is made at once of a solution of 33 grams of sodium acetate CH3-COONa.3H2O in 138 cc. of water, the mixture is shaken for 30 minutes. The resulting 1-(chloracetylamino)-2-methyl-4-bromobenzene is filtered ivith suctien. After drying, the yield amants to 24 grams and after recrystallisation from ethanol the substance malts at 135 G. (b) 20 grams of the crude product obtained as described in Example 2a) are dissolved in 200 cc. of n-butylamine. A slight rise of temperature occurs. After standing overnight, the solution is concentrated and the residue is triturated with 2N-hydrochloric ! acid. The re- stdting crystals of 1- (butylamino-acztyl- amino)-2-methyl-4-bromobenzene hydrochloride are filtered with succion, washed with water and recrystallised from water and then from methanol. The yield amounts to about 90 per cent., the compound melts at 252 C.- 253 C. with decomposition. EXAMPLE 3 A solution of 25 grams of chloracetyl chloride in 100 cc. of benzene is added to a solution of 71 grams of 1-amino-2-methyl-4chlorobenzene in 600 cc. of benzene and the mixture is allowed to stand overnight. The crystallised product is filtered with suction and the benzene solution is evaporated to dryness. As residue there remains the 1- (chloracetylamino)-2-methyl-4-chlorobenzene which after recrystallisation from hexahydrobenzene melts at 132 C. 60 cc. of n-butylamine are poured on 12 grams of the compound thus obtained and the whole is allowed to stand for several hours at room temperature. After the excess of butylamine has been distille off, the residue is taken up in ether and sodium carbonate solution and thoroughly shaken. The ethereal solution is separated and the ether is distille. The base which remains is neutralised with alto- holic hydrochloric acid, during which operation the 1- (butylamino-acetylamino)-2-methyl- 4-chlorobenzene-hydrochloride separates in the form of crystals. Melting point=250 C. EXAMPLE 4

(a) 7 grams of 1-amino-2-methyl-5-chlorobenzene are dissolve in 60 cc. of benzene and the solution is mixed with 6 grams of chloracetyl chloride. At first a separation of crystals is observe which after boiling for a prolonged time under reflux dissolve. During this operation evolution of hydrogen chloride takes place which escapes through the condenser. After boiling for 1 to 2 hours, the whole is concentrated to a small volume and allowed to cool. The l-(chlloroacetylamino)-2-methyl-5- chlorobenzene is obtained in the form of crystals. The yield amounts to about 90 per cent. After recrystallisation from ethanol the substance melts at 138 C. (b) 9 grams of the crude 1- (chloracetylamino)-2-methyl-5-chlorobenzene are heated for 3 hours under reflux with 60 cc. of nbutylamine. The mixture is concentrated, the residue is shaken with ether and potassium carbonate solution, the ethereal layer is separated, the ethereal solution is dried with potassium carbonate and the ether is distille off. Thee l-(n-butyltamino-acetylamino)-2-methyl- 5-chlorbenzene formed is distille under reduced pressure. The product boils at a temperature between 193 C. and 195 C. under a pressure of 1. 5 mm. The base is dissolve in alcohol and after neutralisation with alcoholic hydrochloric acid the 1- (n-butylaminoacetylamino)-2-methyl-5-chlorobenzene hydrochloride is obtained in an excellent yield. The product melts at 237 C. The melting point of the corresponding acetate is 94 C.-95 C. EXAMPLE 5. In a manner analogous to that described in Example 4 (b) the 1- (prapylamino-acetylamino)-2-methyl-5-chlorobenzene hydrochloride melting at 233 C. is obtained from 1- (chloracetylamino)-2-methyl-5-chlorobenzene and propylamine. EXAMPLE 6. (a) 71 grams of 1-amino-2-chloro-3-methylbenzene are dissolve in 600 cc. of benzene and the solution obtained is mixed with a solution of 28 grams of chloracetyl chloride in 150 cc. of benzene. After standing for 1-2 days the reation mixture is thoroughly shaken with water, the benzene solution is separated and the excess of benzene is distille off. As residue, the 1-chloroacetylamino-2-chloro-3- methylbenzene is obtained in a yield of 40 grams. (b) 160 cc. of butylamine are carefully poured onto 40 grams of the compound described above and the mixture is allowed to stand for 1 day at room temperature. The excess of butylamine is then distille off and the residue is taken up in ether and dilute sodium carbonate solution. The ethereal solution is separated and the ether is distille off.

As residue the base is obtained in an oily condiction. The base is converted with alcoholic hydrochloric acid into the hydrochloride. After recrystallisation from methanol the 1- (butylamino-acetylamino)-2-chloro-3-methylbenzene hydrochloride melts at 240 C. 242 C. EXAMPLE 7 From l-amino-3-methyl-4-chlorobenzene there is obtained by rection with chloroacetyl chloride in a manner analogous to that described in Example 4 a) the 1- (chloroacetylamino)-3-methyl-4-chlorobenzene melting at 117 C. The yield amounts to about 90 per cent. The product obtained is reacted with n-butyl-amine in the manner described in Example 4 b). The 1- (butylamino-acetylamino)-3-methyl-4-chlorobenzene boils between 186 C. and 188 C. under a pressure of 2 mm of mercury. The acetate melts at 110 C.-111 C. EXAMPLE 8 (a) 1-(Chloroacetylamino) - 3 - methyl-5chlorobenzene melting at 147 C. is obtained in a manner analogous to that described in Example 4b) from 1-amino-3-methyl-5-chlorobenzene and chloracetyl chloride. The yield amounts to about 90 per cent. (b) l-(Chloracetylamino)-3-methyl-5- chlorobenzene is dissolve in 100 cc. of nbutylarnine and the solution is allowed to stand overnight. A slight rise of temperature is soon notice. The solution is concentruted under reduced pressure. By shaking with ether and potassium carbonate solution the 1- (butylamino-acetylamino)-3-methyl-5-chlorobenzene is taken up in the ether and the ether solution is distille. Boiling point= 194'C. to 195 * C. under a pressure of 3 mm. The acetate melts at 124 C.-125 C. and the lactate melts at 142 C. EXAMPLE 9 (a) 1- (Chloracetylamino)-3-methyl-6chlorbenzene melting at 127 C. is obtained in a manner analogous to that described in Example 4 a) from 1-amino-3-methyl-6- chlorobenzene by rection with chloracetyl chloride. The yield amounts to about 90 per cent. (b) 1- (Butylamino-acetylamino)- 3-methyl6-chlorobenzene can be obtained in an excellent yield by the process described in Example 4 b) from 1-(chloracetyl-amino)-3-methyl-6- chlorobenzene. The product obtained boils at 188 C. 190 C. under a pressure of 5 mm of mercurey.. The lactate melts at 97 C. EXAMPLE 10 From I-amino-3-chloro-4-methylbenzene there is obtained in the manner described in Example 4 a) the 1-(chloroacetylamino)-3chloro-4-methylbenzene melting at 178 C. and from that product there is obtained by reaction with

n-butylamine as described in Example 4 b) the 1- (butylamino-acetylamino)3-chloro-4-methylbenzene which boils at 193 -195 C. under a pressure of 2. 5 mm of mercury. The acetate melts at 107 C.- 108 C. EXAMPLE 11 (a) 112 grams of I-amino-2-methyl-3bromobenzene are dissolve in 770 cc. of glacial acetic acid and t'he solution is mixed with 75 grams of chloracetyl chloride during which operation the temperature rises to about 40 C. A solution of 200 grams of sodium acetate CHsCOONa. 3H2O in 800 cc. of water is then rapidly added, while vigorously stirring. The 1- (chloracetylamino)-2-methyl-3-bromobenzene precipitates in the form of crystals. After stirring has been continued for 1 hour they are filtered with suction and thoroughly washed with water. After recrystallisation from ethanol the compound melts at 140 C. The yield amounts to about 90 per cent. (b) 100 grams of crude, dry 1- (chloracetylamino)-2-methyl-3-bromobenzene are dissolved in 900 cc. of n-butylamine. A slight rise of temperature to about 40 C. occurs. After standing overnight, the solution is concentrated under reduced pressure, the residue is triturated with 2 N-hydrochloric acid and the 1- (n-butylamino-acetylamino)-2-methyl3-bromobenzene hydrochloride formed is filtered with suction. The product obtained in an excellent yield is recrystallised from methanol in order to purify it. It melts at 254 C. with decomposition. The aminosulphonate melts at 185 C. EXAMPLE 12 30. 2 grams of n-butylamino-acetic acid chloride hydrochloride are suspende in 500 cc. of acetone and the rection mixture obtained upon addition of 28. 4 grams of Iamino-2-methyl-3-chlorobenzene is heated for several hours under reflux. After cooling, the crystal magma is separated from to-n-butylamino-acetylamino-2-methyl-3-chlorobenzene hydrochloride by filtering with suction. After recrystallisation from water, the melting point amounts to 260 C. The n-butylamino-acetic acid chloride hydrochloride used as starting material is obtained by rection of n-butylamino-acetic acid with phosphorus pentachloride in acetyl chloride. What we claim is :- 1. Compound of the general formula <img class="EMIRef" id="026415667-00040001" /> in which R represents an alkyl radical having 3 or 4 carbon atoms and Hal represents halogen and the salts of these compound ; the compound of the general formula <img class="EMIRef" id="026415667-00040002" /> in vhich Hal has the meaning given above, and in which R represents an

alkyl radical having 3 or 4 carbon atoms being excluded. 2. Compound of the general formula <img class="EMIRef" id="026415667-00040003" /> and salts of these compound ; the compound of the general formula <img class="EMIRef" id="026415667-00040004" /> being excluded. 3. Compound of the general formula <img class="EMIRef" id="026415667-00040005" />

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* GB785976 (A)

Description: GB785976 (A) ? 1957-11-06

Improvements in or relating to thermosetting molding compositions




PATENT SPECIFICATION 7859976 Date of Application and filing Complete Specification: Feb 2, 1954. No 3054154. Application made in United States of America on March 18, 1953. Complete Specification Published: Nov 6, 1957.

Index at acceptance:-Class 2 ( 5), R 2 (C 4: C 5: H: P 1: P 2), R 29 (C 4: C 5: P). International Classification:-CO 8 g. COMPLETE SPECIFICATION Improvements in or relating to Thermosetting Molding Compositions We, WILLIAM CHARLES McCo Y, of 2712 Claythorne Road, Shaker Heights, State of Ohio, United States of America, and WILLIAM CHARLES McCo Y JR, of 1763 Sheridan Road, South Euclid, State of Ohio, United States of America, both citizens of the 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 the manufacture of thermosetting molding compositions containing a urea-formaldehyde resin or a similar resin such as formaldehyde melamine, formaldehyde biuret or formaldehyde thiourea having thermosetting properties in association with a filler The filler may consist, for example, of a fibrous material such as woodflour, sulfite pulp or alpha-cellulose. Heretofore in the preparation of urea-formaldehyde and similar molding compositions it has been customary to prepare a resin syrup constituting the product of the partial condensation of the urea and formaldehyde and then admix therewith, either in the reaction kettle or in any other suitable apparatus such, as a kneader, a suitable proportion of filler The proportion of filler may vary over a wide range, but usually constitutes from 25-50 % by weight of the total composition determined on a dry basis. The impregnated filler is dried at a carefully controlled temperature so that the water content of the resin syrup, as well as any additional condensation water formed during the drying, may escape without, however, advancing or curing the resin to the point where it will adversely affect the flow and hardening properties of the composition when later subjected to hot moulding The drying operation is a slow operation and a very critical one, and usually is carried out in a continuous type drying oven or in a shelf dryer of the atmospheric or vacuum type. The dry material in lump form is then lPnico 3 s 6 d l ground, usually in a ball mill, to a very fine powder, e g, to about 300 mesh The ball mill must be specially lined to prevent contamination and provided with a cooling jacket so as to keep the temperature of the material below the point where the curing reactions will be advanced The ball milling operation is a time-consuming operation but has been necessary in order to insure uniform distribution of the resin and filler ingredients. The resulting powder is suitable for molding as it is and represents

one commercial grade of molding composition However, at the present time only a relatively small proportion of thermosetting molding compositions of the urea-formaldehyde types are sold in this form, due to their excessively high bulk which makes it difficult to mold the material and even then a long draw or period of confinement in the mold is required This fine powder also has a tendency to burn in the mold and give rise to discolored spots For most applications the fine powder undergoes an additional densifying operation. The densifying operation takes either of two types It is a recent practice, especially with molders, to densify the powder by pre-forming it in a suitable tableting machine However, the excessively high bulk of the powder makes it difficult to preform or tablet Moreover, when the tableting is done by the molder there are increased shipping costs due to the bulkiness of the powder. The other method of densifying consists in putting the fine powder into a banbury mixer or a mixer of similar type where it is mixed and kneaded under controlled heating conditions to bring about fusion of the powdered material and its conversion into lumps This operation has to be very carefully controlled, because if the time is too long or the temperature is too high the material tends to cure in the presence of the curing catalyst, which is customarily added at the ball milling stage, and loses its ability to flow when later subjected to hot molding. Mce 45 f-P The fused or compressed material obtained by either of the densifying methods mentioned above, is then granulated, usually by means of special granulating apparatus to produce a material with a low bulking factor suitable for satisfactory and rapid molding The granulated material obtained from a densified product produced by the mixing and fusion method contains much less fines and has a much more satisfactory bulking factor than the product obtained by merely compressing into tablets since the latter type of products shows a tendency to break up into powder again. It will be understood that the many operations that have been heretofore required to produce a satisfactory densified and granular product add very considerably to the cost of the product It has been the endeavor of workers in the art for a long time to simplify the process and eliminate some of these operations However, so far as we are aware, prior attempts to reduce the number of steps have not been successful and have resulted in a product having many basic shortcomings in one respect or another. The improved process of the present invention eliminates many of the complexities of the prior practice and yields a product having full commercial value This process has the advantages of simplicity of operation, reduces the investment in equipment and the cost of

processing as respects labor, time and required power, and insures close control of the product. According to our process the initial resinforming reaction is carried on in the presence of the filler and brings about the simultaneous impregnation of the filler The urea and formaldehyde ingredients are introduced in the dry form along with the filler into a jacketed mixer or kneader of any closed type Preferably a ribbon type mixer is employed A machine of light construction is suitable since the material is at all times free-flowing and easy to handle The mixer is closed and heated with mixing until the temperature has been brought to the point where the condensation reaction will take place As soon as condensation begins the mixture becomes wet and the water liberated helps to wet and impregnate the filler The mixing is continued until most of the water of condensation has been liberated and the condensation has been highly advanced At this stage the reaction is arrested by quickly bringing the temperature down by cooling When the temperature has been brought down to a sufficient degree, the curing catalyst is added to the mixture and the cooling continued with further mixing for an additional short period of time. The cooling and addition of the catalyst can be done either in the same mixer or the material can be transferred to another mixer of the same type for the cooling stage Since the initial mixing during the reaction is done in a closed vessel so that the water liberated is not permitted to escape and the temperature within the mixing chamber will usually be above the boiling point of water during the reaction period, cooling and simultaneous 70 removal of the water in the form of vapors will be facilitated by opening the mixer or transferring the charge to a second mixer open to the atmosphere and also preferably provided with a cooling jacket Usually the water 75 present will be only that amount liberated in the condensation reaction However, a controlled small amount of water may be added at the beginning of the operation, care being taken to keep the proportion of added water 80 below the point where the product as it is discharged from the cooling mixer, or at the end of the cooling step when conducted in the initial reaction mixer is noticeably wet or lumpy Because the amount of water present 85 is limited, the super-heat contained in the water, in the form of steam, and in the reaction mixture will usually be sufficient to cause substantially all of the water to pass off as vapors upon opening the mixer to the atmo 90 sphere with an accompanying cooling action on the remaining mixture. The reacted material, containing the curing catalyst and any other additions that have heretofore been made at the ball milling 95 stage, such as a lubricant, dyes or pigments, and sometimes a plasticizer, is then transferred to a heated, mixing or kneading apparatus suitable

for further densifying the material and there subjected to continued mixing or knead l OC ing under conditions permitting of the free escape of any remaining traces of water and, at the same time, densified into lumps This operation is a short one and yields a finished molding compound which has only to be 105 granulated or pulverized in a grinding operation. The following example is further illustrative of the practice of the invention: A jacketed ribbon type mixer is loaded 11 C with 50 lbs alpha-cellulose filler, 79 lbs urea, lbs paraformaldehyde, 65 lbs ammonia, 3 Ibs hexamine, 25 lbs zinc stearate and the necessary amount of pigments or dyes depending on the desired color 11. The mixer is then closed with a lid and heated to bring the temperature of the mix to about 200-230 deg F When the temperature rises, it can be noticed immediately that the mixture gets wet from the condensation 121 water resulting from the reaction between the paraformaldehyde and urea and formation of the resin This condensation water helps to wet and impregnate the alpha-cellulose, and some pressure may be developed in the mixer which 12 further aids in the impregnation The contents of the mixer reduce in bulk When the reaction temperature is reached, the reaction is continued for an additional period of timeusually 5-10 minutes depending on condi 13 785,976 The finished material possesses all the desirable properties of the best grade conventional molding material To be more specific, it has the following physical characteristics: tions-and the mixer is then opened to enable the condensation water to escape as vapors. The heating is continued with the agitator running The vapors escape very fast, and the resulting free flowing particles of impregnated fiber feel only very slightly moist An indication that the condensation reaction is completed is the lack of formaldehyde odor This drying usually takes about 5-15 minutes depending on conditions Following opening of the lid, the temperature usually drops to about deg F. At this stage, an additional 2 lbs of hexamine is added, and a catalytic amount i e. a relatively small amount such as 1 % by weight of epichlorohydrin or another suitable latent curing catalyst figured on the dry weight of the mixture is added The bottom valve is opened and the material is transferred to another identical mixer for cooling This mixer is agitated and water is circulated through the jacket The material remains in this mixer until the catalyst and the hexamine have been intimately admixed with the resin-impregnated filler. During the interval when the mixture is being worked in the second

mixer, the first mixer is ready to accept another charge and may be put in operation to produce a second batch of the resin-impregnated filler material. Upon completion of the mixing operation in the cooling mixer, the resulting mixture is then charged into a heat densifier which may, for example, be of the muller type as currently manufactured by Beardsley & Piper, Inc for compounding plastic materials In this apparatus the material undergoes a very thorough mixing under the action of rolls and is densifled into small lumps At the same time, any remaining water and volatiles are sucked out by means of a suction fan mounted on the top of the machine This densifying treatment is very short and usually is completed in from 2 to 4 minutes The material is then discharged on to a moving conveyor belt. The conveyor brings the material to a small crusher, preferably of the cutter type, where the material is then cut into small pieces This operation is an important feature of the invention in that it provides a rapid cooling and dissipation of heat acquired by the material under the working of the rolls in the densifier and prevents any further advancement or curing of the molding material On passing through this small cutter the material is then conveyed to a larger cutter where the final granulation takes place. The speed of the conveyor and the length of the conveyor belt should be such as to allow the material to cool sufficiently before it is fed to the larger cutter for the final grinding step. The material leaving the cutter is in a finished state and can be sold as it is or blended into larger batches in any suitable blender of a ribbon or conical type. Specific Gravity Bulk Factor Water Absorption at L Compressive Strength, lbs /sq in. Tensile Strength, lbs /sq in. Dielectric strength, Short Time -V/Mill Arc Resistance Impact Strength, Izod ft lbs /in. Molding Properties Preforming Properties Translucency Boiling Water Resistance (after min boiling) 1.5 )out 2 5 ess than 5 % 35,000 5,500 350 24 Excellent Excellent Excellent Excellent Various modifications in the procedure as well as various substitutions or changes in the 85 proportions of the ingredients of the composition may be made without departing from the invention For example, the ratio of the filler to urea and paraformaldehyde may be varied over a wide range depending on the 90 desired translucency and strength characteristics Any other suitable filler, such as walnutshell flour, woodflour, sulfite pulp and similar materials may be used in place of alpha cellulose Likewise, urea may be replaced in whole 95 or in part by melamine, thiourea, biuret, and similar amino compounds Any buffering alkali,

such as triethanol amine, can be used in place of ammonia as long as the alkaline conditions are equal We prefer to use ammonia 100 because of its reactivity with formaldehyde and the effect of the formed hexamine on the final curing speed. We prefer to add hexamine in two steps It is added in the first step to establish an 105 alkaline condition favorable to the promotion of the condensation reactions Addition of hexamine in the second stage tends to speed up the final curing of the molding compound in the subsequent hold molding operation The 110 amount of hexamine introduced in the second stage may be either increased or decreased depending on the curing speed required. When using a high proportion of filler or a relatively high proportion of pigments, it is 115 sometimes advantageous to introduce a small amount of water-say between 2-l and 5 % by weight of the total dry weight of the ingredients of the reaction mixture-to improve the impregnation of the filler and dis 120 persion of the pigments and other additions more uniformly throughout the mixture. Although the invention may be practised with use of a wide range of curing catalysts, and especially those known as latent catalysts, 125 we prefer to use epichlorohydrin because it has a number of advantages not possessed by any single catalyst heretofore used so far as we 785,976 are aware In the first place, it is a liquid and, therefore, easy to disperse It is very inactive at low temperatures and therefore, can be added even at an early stage of the mixing without curing the resin It has been established that the mix can even be left for 24 hours at 140 CF without any changes in its character and even without any effect on further processing Finally, this catalyst has a very rapid curing action at conventional molding temperatures Although it is advantageous to add the curing catalyst to the mixer either immediately after the condensation reaction has been arrested and substantially all of the water has been driven off, or to the second mixer at the beginning or during the mixing operation therein, it is also possible to add the catalyst at any later stage in the second mixer or in the densifier up to a minute or two before the material is ready to be discharged from the densifier When the catalyst used is more reactive than epichlorohydrin under the conditions obtaining either in the mixer or the densifier, it will be desirable to postpone its addition to the mixture until near the end of the densifying operation in the densifier. The product as it is discharged from the larger cutter is in the desired granulated form for molding, thus making it unnecessary to resort to any ball milling or micro-pulverizing operation However, if for any reason the powdered form is desirable, the granulated material can be pulverized in a micropulverizer or even ball milled to a fine

powder For example, for some purposes. it may be desirable to make the material in colorless form and add the color later In such case a colorless material can be prepared by reacting, mixing and densifying as above described The colorless product can be pulverized and blended with dyes or pigments, or even a curing catalyst, in the ball mill or micro-pulverizer If a final granulated material is desired, the powder can then be redensified in the Beardsley & Piper densifier or compressed in a tableting machine and finally regranulated. The proportion of filler may vary over a wide range, usually not exceeding 60 % by weight of the total composition, and more generally falling in the range 25-50 % by weight based on the weight of the dried material. Pulverizing the dried impregnated material in a suitable pulverizer such as a micropulverizer, is more advantageous than employing a ball mill since a pulverizer permits a faster and more economical operation and gives a superior product A ball mill is however frequently used for grinding molding compositions since it permits the addition of other components to be ground and blended simultaneously therewith. Although this invention has been described with particular reference to urea-formaldehyde thermosetting resins and molding compositions made therewith, it is also applicable to molding compositions whereof the resin component may be any of various other thermosetting amino resins such as the thiourea-formaldehyde 70 and melamine-formaldehyde and biuret-formaldehyde thermosetting resins.


* GB785977 (A)

Description: GB785977 (A) ? 1957-11-06

Improvements in or relating to flame resistant film-forming composition




PATENT SPECIFICATION Inventor: GEORGE W MOD 7859977 Date of Application and filing Complete Specification Feb 20, 1954. No 5064/54. Complete Specification Published Nov 6, 1957. Index at Acceptance:-Class 2 ( 5), R 2 C( 2:4: 6:8:9: 12: 13:17), R 3 C( 2: 4: 6:8:9: 12: 13:17), R 29 C( 2: 4: 6 8: D: 12: 13: 17). T ernational Classification: -CO 8 g. COMPLETE SPECIFICATION Improvements in or relating to Flame Resistant Film-Forming Composition We, THE CELOTEX CORPORATION, a Corporation organised under the Laws of the State of Delaware, United States of America, of 120, South La Salle Street, Chicago, Illinois, 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:In the past there have been many efforts made to provide fireproofing coatings for application to various combustible substances, in particular to such materials as wood, fibre boards, paper wallboards, paper, and the like. So far as is known, these previously provided coatings cannot properly be called " fireproofing coatings " since they are in fact " flameresisting coatings ", that is, they merely resist the effect of flame applied to the surface of the materials, and consequently herein the coating comprising the subject matter hereof will be referred to as a " flame-resistant coating". There are, it is believed, a number of flameresistant coatings, most of which, however, are either relatively ineffective or they are difficult to apply, or have a very short usable life, since the ingredients, which are usually supplied to separate packages or containers for mixing, just before use, react relatively rapidly to cause the mixture to set up If the mixture is quickly applied as a coating within the period of the effective life of such mixture,

generally not more than three or four hours, it is possible to apply a coating material which will set as a more or less effective flameresistant coating. Due to the deficiencies of such previous flame-resisting coating compositions, the intumescing coating composition hereof has been developed as a composition which may be applied the same as ordinary paint and which l has an effective use life which is many, many times that of the somewhat similar coatings previously available, and which in fact, for all practical purposes may be considered to have an infinitely long life, since batches have been made up and satisfactorily applied several weeks to a month after having been prepared. As a general description of the composition hereof, it may be described as a paint composed of pigment, if colour is required in the composition, flame retardant material, binder, dispersing and plasticizing agents, and solvent In this composition the pigment, or at least a part of the pigment, does, in addition, serve as a flame retardant ingredient, as may the binder, or at least an ingredient of the binder materials. As a general description of the action of the composition when applied to a surface, that is, for example, a surface of a fibre board or wood, as a paint film, such film, when sufficient heat is applied, as, for example, by impingement of flame, softens, intumesces, and release flame-smothering gases It is in particular essential that the film-forming ingredients of the composition, that is the binder, shall suitably set up and bond the formed film to the surface to which it is applied, but the film must be one having the property which under the application of heat, as by flame, will soften slightly or become sufficiently plastic so that the intumescing ingredients incorporated in the film may expand to provide a relatively thick, spongy or cellular layer serving to protect the surface to which the coating has been applied. It is broadly an object of the invention hereof to provide a paint-like composition, or coating material, which may be in general handled as paint to provide a decorative paintlike film on the surface of a combustible element to provide protection for such combustible element against flame impinging surface thereof Specifically, it is an object of this invention to provide a composition in accordance with the foregoing general object of the invention, which to all intents and purposes is merely a paint coating until sufficiently heated or impinged by flame, whereupon such coating will itumesce to provide a relatively thick, porous and cellular layer which serves to protect the material from burning In particular, it is a further object of the invention hereof to provide such a composition which has a relatively

long use life, and which is made up or compounded in the form of a paint, and which is not composed of ingredients reactive to the extent that the ingredients must be supplied for use separately packaged for admixture immediately previous to the use of the mixture of the ingredients applied as a coating. The present invention provides a flameresistant film-forming composition comprising (a) finely divided particles of a material selected from amino aldehyde resins, oil seed meals and casein; (b) an ammonium phosphate in finely divided form which liberates gas which is a non-supporter of combustion when heated to about 3000 F; (c) a film-forming water-insoluble amino-aldehyde resin soluble in an organic solvent in combination with an alkyd resin; and (d) an organic liquid which is a solvent for said film-forming resins but not for said finely divided particles nor said ammonium phosphate, and (e) a pigment, if colour is desired in the composition. The present invention also provides a flame resistant paint composition comprising ingredients which, when a set film thereof is heated, softens and spumifies due to the puffing action of gases given off by the pigment and filler ingredients thereof and comprising dispersed particles of pigment, amino-aldehyde resin and alkyd resin in combination, and an ammonium phosphate compound, an alkyd resin a film forming water-insoluble amino aldehyde resin soluble in an organic solvent in combination with said alkyd resin, and an organic liquid which is a solvent for said film-forming resins but not for said dispersed particles. The preferred composition for a white paint, flame-retardant coating, is one comprised of the white pigment, lithopone, which is comprised of zinc sulphide and barium sulphate, and titanium dioxide The lithopone component serves in the composition not only as a white pigment, but it also has a flameretardant action in that in the composition, and under the influence of heat, the zinc sulphide decomposes to release hydrogen sulphide gas which aids in the swelling of the cellular layer The principal flame retardant materials of the composition are, in this representative example, a solid urea-formaldehyde resin, mono ammonium phosphate, and zinc sulphide reactive pigment The reactive pigment is a pertinent part of the flame retardant materials and definitely beneficial in this intumescent paint The binder is a liquid ureaformaldehyde resin and a medium oil length styrenated alkyd As dispersing, plasticxzing, and suspending agents, there are employed 70 small amounts of soya lecithin, pine oil, Plamre resistant tricr-syl phosphate, and aluminium stearate Finally, as the solvent, there is employed mineral spirits. The solid urea-formaldehyde resin, above 75 referred to, is a form of urea-formaldehyde which is soluble in water but insoluble in the

solvent of the composition That is, it is insoluble in mineral spirits and available on the market as a white solid, water-soluble urea 80 formaldehyde resin prepared by reacting urea and formaldehyde in water in the presence of glacial acetic acid as a catalyst The liquid urea-formaldehyde resin is a butylated ureaformaldehyde resin which is insoluble in water 85 but which has a wide range of compatibility with medium and long oil alkyds and oleoresinous varnishes, being dissolved in an admixture of xylol and butanol as a solvent, or in a high flash naphtha, and which liquid 90 resin may be diluted with mineral spirits The styresol ingredient is a styrenated alkyd in xylol, preferably of a medium length are preferably employing soya bean oil as the drying oil The mineral spirits used is ordinarily 95 available merely as mineral spirits but which, however, vary slightly from different sources but which, in general, is a mineral spirit fraction having a flash point from about 105 to 1200 F, and a specific gravity of approxi 100 mately 8. A preferred and specific composition comnprising the foregoing described ingredients comprises:PIGMENTS Lithopone Titanium dioxide grams 907 109 FLAME RETARDANT grams Solid urea formaldehyde resin solvent insoluble 567 Mono ammonium phosphate 1701 BINDER grams Liquid urea formaldehyde resin, Water insoluble 386 Medium oil length styrenated alkyd 680 DISPERSING AND PLASTICIZING AGENTS grams Soya lecithin 17 Pine oil 2 Tricresyl phosphate 110 Aluminium stearate 5 Solvent 1082 785,977 785,977 The above comprises a total volume when admixed of one gallon. To prepare a paint coating composition according to the above formula, all the ingredients excepting a portion of the solvent are placed in a pebble mill and ground to the desired fineness, and finally the balance of the solvent is incorporated. The foregoing composition has been more particularly developed as an industrial paint or coating, and is preferably applied by spraying In order to quickly set the paint, and in particular to further polymerize the liquid urea-formaldehyde resin ingredient thereof, the applied film is air dried for a short time, say, around 15 minutes, and the drying is completed by oven drying at 240 to 250 F. for about 35 or 40 minutes. This drying practically completely, we believe, polymerizes the urea-formaldehyde resins We are not sure what exactly happens to the styrenated alkyd, but do know, however, that the binder ingredients of the film collectively retain such thermoplasticity that the film softens when subjected to flame. The solvents are released from the coating during the drying operation Thus, a hard, well bonded film is formed by the originally liquid urea-formaldehyde resin and the medium length styrenated alkyd with

the pigment, mono ammonium phosphate, and originally solid UF ingredients distributed throughout the coating. The above coating composition is applied at the rate of approximately seven gallons per 1000 square feet, or with a coverage of 145 to square feet per gallon This coverage may he varied to satisfy the surface upon which it is sprayed This film, when dried and polymerized, as above, is to all intents and purpose an ordinary decorative paint film, that is, the composition is a satisfactory interior paint This paint coating can be tinted by incorporating a small amount of suitable colouring pigment, either as a substitution or addition. While the coating applied as above described, and dried and polymerized, has the appearance of an ordinary paint coating, it is nevertheless a flame-resistant coating If flame is applied to the surface of this coating, the binder softens sufficiently so that the intumescing ingredients may swell or intumesce under the effect of applied heat In particular the solid urea-formaldehyde resin ingrtdient carbonizes, the mono ammonium phosphate decomposes and releases ammonia gas and phosphoric acid, the zinc sulphide ingredient of the lithopone reacts with the phosphoric acid liberating hydrogen sulfide These gases which are formed within the film, together with other gases which may be formed in small amounts by other reactions which occur in the film, serve to intumesce the resinous paint film, and this film ordinarily will swell up to a thickness of from one-quarter to about one-half inch as a spongy, porous charred mass, and even though it is continued to be subjected to flame, it will remain in place for an appreciable period of time to effectively 70 insulate or protect the surface to which the paint film was applied The intumesced film is effective since not only does it keecp the flame from the surface of the combustible material to which the film was applied, but it 75 also prevents access of air to such surface with the consequence that without sufficient oxygen the surface is protected from actual combustion. While in the foregoing a specific formula 80 has been given, it is to be understood that those skilled in the art of paint formulation will understand that certain variations from the exact formula are permissible, and that various substitutions can be made For example 85 for the pigment ingredients there may be substituted, pound for pound, zinc sulphide, or substantially any other available sulphide, with the understanding, of course, that the finished composition will be coloured in 90 accordance with the colour of sulphide which is substituted For example, there could be substituted lead sulphide, iron sulphide, cadmium sulphide or substantially any other available metallic sulphide, which sulphides 95 will, similarly to the zinc

sulphide, be broken down by the available phosphoric acid to release hydrogen sulphide Proper inert pigments if a pigment is to be used may be substituted for the pigments employed in the 100 example, although decreased flame resistance will be realized and thus it is highly desirable to have a pigment, such as employed in the example, present. For the specific solid urea-formaldehyde 105 resin of the formula there may be substituted other generally similar resins For example, there may be substituted melamine formaldehyde resin or dimethylol-urea or any other generally similar resin and compounds com 110 prised of the reaction product of formaldehyde and amino resin forming reactives; or proteins such as the various oil seed meals, preferably refined, or alpha protein (i e protein substantially pure which results from the 115 refining of soyabean or other seed meals) or casein may also be substituted for the specific resin. Other compatible binders, dispersing agents, and pigment suspending agents may be sub 120 stituted for those specifically set out in the example, but it is to be understood, of course, that these must be compatible with the principal ingredients, and that the amounts thereof must be adjusted according to experi 125 ence to obtain the required or equivalent effect in dispersing the ingredients, plasticizing and the like. Our preferred composition possesses a successful blend of good paint characteristics 130 785,977 with excellent flame resistance This paint possesses good industrial spraying qualities, satisfactory paint life, has the film forming characteristics, appearance and washability of a good interior oil paint after oven drying. However, when a flame or sufficient heat is applied to this decorative film it softens and then the intumescent, flame retardant materials become active, forming a puffed, porous, and cellular protective coating for the surface to which it has been applied.


* GB785978 (A)

Description: GB785978 (A) ? 1957-11-06

Improvements in or relating to the manufacture of synthetic filaments,fibres or yarn

Description of GB785978 (A)

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FR1128895 (A) NL106133 (C) FR1128895 (A) NL106133 (C) less Translate this text into Tooltip



PATENT SPECIFICATION X tagnr DENNIS CAMPBELL HOOK WAY D ite, 7 fiiag Complete Specification July 8, 1955. Aticatio,7 Date July 17, 1954 No 2289. Complete Specification Published Nov 6, 1957. Index at acceptance:-Class 2), E( 2: 3: 5), i E 6 D( 1: 20 X). International Classification:DO 6 m. COMPLETE SPECIFICATION Improvements in or relating to the Manufacture of Synthetic Filarmenits, Fibres or Yarn We, BRITISH NYLON SPINNERS LIMITED, Of Pontypool, Monmouthshire, a British company, do hereby declare the invention, for which we pray that patent fay be granted to use, and the method by which it is to be performed, to be particularly described in and by the following statement: - This invention relates to the manufacture of filaments, fibres or yarn and more particularly to filaments, fibres or yarn made by spinning a high molecular synthetic linear condensation polymer in the molten condition. It has long been known that the strength of man-made filaments, that is to say, the breaking load per unit of cross-section, may be advantageously increased by submitting the solid filaments to drawing

The ratio of the length of the extended filaments to their original length before drawing is referred to as the draw ratio Since the process of drawing causes very little or no change in density, the draw ratio may be regarded as equal, or very nearly equal, to the ratio of the crosssectional area of the undrawn filament to that of the drawn filament Whilst the above-mentioned effect of drawing on strength is found to occur in some measure in the rayons or older man-made filaments based on cellulose, it is especially important with regard to the wholly synthetic linear polymers which have been developed in the course of the last two decades In the case of the latter polymers, for instance, polyamides, research on their molecular structure has shown that they are in general partly crystalline and partly amorphous Current theory also teaches that the chains of atoms forming the molecules are very long, being associated together partly in orderly fashion so as to constitute the crystalline material, and partly as a ravelled skein which represents the amorphous material The extent of the crystalline fraction of the polymeric material may be referred to as the crylPrice 3 s 6 d l n-o; 4 'e S stallinity thereof In each of the crystalline portions or regions of the polymeric material the linear molecules are visualised as lying side by side parallel to each other During the process of drawing it is supposed that some molecular rearrangement occurs whereby a greater degree of alignment of the linear molecules is achieved The degree of alignment may be termed the orientation of the polymeric material. Whatever be the truth of the above theory, the fact remains that when a solid filament of a synthetic linear polymer, which has been spun from the melt, is drawn, its strength is greatly enhanced Moreover if the drawing is effected quickly enough or under certain other conditions specified below, which generally have the effect of raising the tension of drawing, then the narrowing down of the filament occurs abruptly with the formation of whilet is known as a neck or shoulder That is to say, the process of narrowing does not take place gradually along a lengthy piece of filament but is restricted to a very short portion thereof As the filament is drawn, the neck proceeds therealong, drawn material being on one side of it and undrawn material on the other When a neck is thus spontaneously produced, the ratio of the cross-sectional area of the undrawn filament to that of the drawn filarnent, is often termed the natural draw ratio If the filament being drawn is otherwise stationary, the neck travels along as the thicker filament is transformed into the thinner drawn material If on the other hand the filaments are being drawn continuously, for instance, by passage between feed rolls followed by draw rolls running at a higher peripheral speed, then, provided the ratio of the peripheral speeds of the draw and feed rolls, that is the mechanical

draw ratio, is equal to the natural draw ratio, the neck will remain stationary. Should the applied mechanical draw ratio 7859978 5154. 7 ( 1 so 785,978 exceed the natural draw ratio, the neck will run back to the feed rolls Similarly if a smnaller than natural draw ratio is applied, the neck will proceed to the draw rolls The preceding remarks have been made on the assumption that only one neck is developed in the filament. It has now been found that novel filaments can be produced by drawing the present polymers at a neck under conditions which are defined hereinbelow, for example at a sufficiently low temperature or low humidity Thb new filaments are characterised in that they contain internal cavities or lacunas and may be referred to as lacunose The cavitation or internal cleavage occurs at the neck during drawing and frequently assumes the form of capillaries It is supposed that this cleavage is due to radial forces z O at the neck which result from the tension of drawing and that if the said tension is great enough, then the radial forces produced therefrom overcome the cohesion or resistance to cavitation of the material Thus the cleavage will occur if the said radial forces are great enough and/or the said cohesion small enough It may well be therefore that the effect of the low temperature or low humidity is to raise the shear strength of the material, so that a higher drawing tension is necessary, without, surprisingly, causing a corresponding increase in the cohesive strength. The speed of drawing can also be raised in order to produce lacunose yarn These conditions, namely, low temperature or humidity or high speed of drawing may be regarded as raising the tension of drawing, which in turn increases the aforesaid forces and so mankes the yarn lacunose Consequently the drawing tension is often a guide as to the right conditions for making lacunose yarn On the other hand a low degree of orientation seems to give rise to lacunose yarn by reason of its reducing the cohesive strength, but the invention is not dependent on the accuracy of these theoretical considerations. The conditions which yield lacunose filaments are defined then as a high speed of drawing and/or a high crystallinity and/or a low degree of orientation in the polymer and/or a low temperature and/or a low degree of atmospheric humidity or moisture content in the polymer, wherein by high or low, it is meant that each condition or factor concerned exists in a sufficiently high or low degree respectively in order to lead to the formation at a neck of drawn filaments with cavities The essential condition regarding the moisture resides in the actual moisture content of the polymer whilst the yarn is undergoing the process of drawing This depends on the humidity of the atmosphere

in which the yarn has been stored, and with which it is in eqluilibrium Often, doubtless, (in air-conditioned premises) the drawing would take place in the same atmosphere, but even where this is not so, a somewhat different humidity in the atmosphere surrounding the drawing machine, would normally have little or no effect on the result because the time of contact of the yarn 70 therewith would be too small It is thus advantageous that the polymer used in the present process be as dry as possible For this purpose it is convenient to store the bobbins of undrawn filaments before use in a dry atmos 75 phere The crystallinity of the polymer may be increased by annealing it at a suitable temperature, e g for 20 hours at 160 C in an atomsphere of nitrogen The orientation may be estimated by X-ray methods, but the bire 80 fringence, which is easily determined, is often regarded as a measure thereof The crystallinity, if desired, may be estimated by X-ray examination or by measuring the isotropic refractive index er frequently, the density It 85 will be appreciated that the conditions defined are interrelated or co-operative in the sense that if several conditions are altered at once, they may be varied to a lesser degree Conversely one condition might be modified, i e 90 increased or decreased to such an extent as to make it unnecessary to change any other For instance, provided the polymer be sufficiently dry, there is no need to lo laer the temperature. In any case it wvill readily be understood that 95 the adjustment in the above conditions should not in general exceed a moderate degree, because too extensive an alteration makes it impracticable to draw the filaments owing to their frequently breaking It will further be 100 apparent that the extent to which the said condition need altering depends on the particular synthetic linear polyrmer chosen For example, in the case of polyhexamethylene adipamide the following remarks may be made 105 by way of general guidance, although it is impossible to assign exact limits to the permissible variation in the required conditions owing to the fat that, as already mentioned, the necessary conditions are themselves inter 110 denendent or interrelated Thus for producin C,acunose yarn of nolyhexamethylene adip. amide it m ay be zenerally said that the degree of orientation of the polyner should be low enough so that its birefringence does not 115 exceed the value of 0 012; the moisture content is preferably not above 1 3 %,o which cor responds to a relative humidity of 20 % at 250 C in the atmosphere in which the undrawn filaments have been stored until their moisture 120 content has become constant; the drawing temperature should usually be below 600 C and is preferably about 400 C or lower, but it will be understood that the temperature at the neck is somewhat above that of the 125 undrawn yarn owing to the work done

in drawing As a guide to a suitable degree of crystallinity, an isotropic refractive index of 1.5365 is mentioned The speed of drawing may be made as high as practicable for the 130 785,978 particular yarn in question, smoothness of drawing and avoidance of rupture being taken into account. Accordingly the present invention relates to a process for the manufacture of lacunose filaments by continuously drawing in a solid state a running or travelling yarn or bundle of filaments, which have been melt-spun from a high molecular synthetic linear condensation polymer, characterised in that one or more of the following conditions are chosen, namely, a high degree of crystallinity of the polymer, a low degree of orientation of the polymer, a low moisture content of the polymer, a high speed of drawing and a low temperature of drawing, as hereinbefore defined, so that an abrupt neck is formed in the filaments and cavitation expression occurs within the filaments the position of the neck in the running filaments being stationary or only allowed to hunt up and down a restricted path. The expression "travelling yarn or bundle of filaments " is to be understood as including a monofil or monofilament yarn. The invention includes lacunose filaments of high molecular synthetic linear condensation polymers, and in particular such filaments when manufactured by the above process and also staple fibre made therefrom, and yarn whether made from the continuous filaments or spun from the staple fibre. By way of high molecular synthetic linear condensation polymers suitable for use in this invention there may be mentioned: polyureas, polyurethanes, polyamides, polyestezs and polytriazoles Examples of such polymers are: polyhexamethylene urea, polydecamethylene urea, polybutylene glycol hexamethylene dicarbamate, polyhexamethylene sebacamide, polyhexamethylene adipamide, polypentamethylene adipamide, polyoctamethylene adipamide, polydecamethylene sebacamide, polypentamethylene sebacamide, polydecamthylene hydroquinone diacetamide, polycaprolactam, polytrimethylene terephthalate, polyethylene terephthalate and polyoctamethylene-4-amino-1:2: 4-triazole It is to be understood that under the expression polymers, interpolymers or copolymers are intended to be included, for example, interpolyamides made by heating together 5-aminocaproic acid, hexamethylene diamine and adipic acid. In the present process of continuous drawing, the position of the neck in the running filaments must be stationary, or must only be allowed to hunt up and down a restricted path. Such control of the neck may be effected by adjusting the mechanical draw ratio This is conveniently accomplished automatically, as, for

example, by making any substantial shift in the position of the neck operate a photoelectric cell and thus bring about by suitable electrical means any necessary alternation in the draw ratio by varying the speed of the draw (or feed) rolls The position of the neck may also be controlled by maintaining a local zone of conditions more favourable to drawing than the ambient conditions The neck would tend to remain, for instance, in a warm bone, but care would have to be excercised to ensure that the temperature of the said zone did not nullify the conditions essential to the production of the present lacunose filaments If desired the position of the neck may be adjusted by passing the filaments round a suitable snubbing pin though in this case the draw ratio will not necessarily be that obtaining when the filaments are drawn freely. By comparison with the solid filaments of synthetic linear polymer of a given denier, the present lacunose filaments show an increase in diameter of approximately 10 %, although there is little or no loss in tenacity They have a brighter and more lustrous appearance, they also possess, when woven into fabrics, considerably greater covering power owing to the enhanced reflection of light. EXAMPLE 1. Undrawn polyhexamethylene adipamide melt-spun yarn consisting of 34 filaments with 1 turn per inch Z (total denier 1110) is drawn at a rate of 20 feet per minute (refrring to the undrawn yarn), the draw ratio being 4 1 The temperature of the undrawn yarn is 220 C. and it has a moisture content of circa 0 1 %, having been in equilibrium with an atmosphere of relative humidity 1 % The resulting drawn yarn has a denier of 272 It is lustrous, being much brighter and having a much greater covering power than yarn made in the same way except that the latter yarn has a moisture content of 4 1 %, having been in equilibrium with an atmosphere of relative humidity 60 %. EXAMPLE 2. The starting material is undrawn polyhexamethylene adipamide melt-spun yarn consisting of 15 filaments and having a total denier of 216 and -2 turn per inch Z twist; its iso 110 tropic refractive index is 1 5373, its birefringence 0 0077, its temperature 450 C, and its water content 2 % This yarn is drawn at feet per minute Lustrous lacunose yarn results If the temperature of the yarn is raised 115 to 650 C the production of the lacunose yarn becomes intermittent and at 700 C it disappears, ordinarily solid yarn being formed. EXAMPLE 3. Example 2 is repeated except that the tem 120 perature of the yarn is raised to 400 C and the drawing speed to 120 feet per minute Lacunose yarn is obtained. EXAMPLE 4.

The same yarn is used as in Example 2 125 except that by exposure to a relative humi785,978 dity of 15 % its moisture content is raised to 1.0 %i O The yarn is drawn at 100 feet per minute, the neck being maintained in position by an electrically heated hot wire which encircles the yarn so as to produce a warm zone in the vicinity of the neck The draw ratio is 4 15 The yarn becomes lacunose as it is drawn. EXAMPLE 5. Example 4 is repeated except that the drawing speed is raised to 120 feet per minute and the temperature of the undrawn yarn to 350 C Lacunose yarn showing good covering power when woven into fabrics is obtained. EXAMPLE 6. Low twist undrawn polyhexamethylene adipamide yarn of 15 filaments (total denier 210) has the following properties:Birefringence 0 0047 Isotropic refractive index 1 5368 Moisture content 0 37,% Lacunose yarn is made by drawing the above yarn, having a temperature of 35 C at 60 feet per minute. EXAMPLE 7. Undrawn polyhexamethylene adipamide low twist yarn consisting of 5 filaments, each of 20 denier, is found to have the following properties: Birefringence 0047 Isotropic refractive index 1 5366 Moisture content 0 4 % Excellent lacunose yarn is obtained by drawing the above yarn at 20 feet per minute, the temperature of the undrawn yarn being 220 C 35 EXAMPLE 8. Undrawn polyhexamethylene adipainide monofil which has been melt-spun so as to have a denier of 69 is drawn at 10 feet per minute at room temperature giving lacunose 40 monofilament This polyamide has the following properties: Birefringence 0 0022 Isotropic refractive index 1 5374 Moisture content 0 4 X 45 The drawing tension applied to the monofil (denier 69) is 40 grams, and the draw ratio 4.0 When the speed is reduced as shown by the subjoined data the lacunose yarn ceases to be formed: 50 Drawing tension 1 Lacunose yarn grams 36 grams grams grams Produced. Produced intermittentiv. No longer produced. No lacunose yarn. EXAMPLE 9. Polyhexamethylene adipamide yarn as described in Example 2 is employed except that it is dried at 320 C so that its moisture content is 2 % _ No lacunose yarn is obtainable even though the drawing speed is increased to 1500 feet per m inute at room temperature. On reducing the moisture content, however, as shown in the following table, lacunose varn is obtained: Temperature of Moisture I drying content Lacunose yarn 320 C 2 0 %: None formed.

350 C 1 8 % None formed. 400 C 1 3 % Lacunose yarn formed. 450 C 1 1 % L acunose yarn formed. EXAMPLE 10. Undrawn polycaprolactam monofil is drawn at 20 feet per minute at room temperature with production of a lacunose monofilament. The undrawn polycaprolactam monofil used has the following properties:Denier -70 Birefringence O 0004 Isotropic refractive index 1 5352 Moisture content 0 4 %
