Патент USA US3082067код для вставки
Md 3,982,951 Patented Mar. 19, 1961 2 1 Ward ?nding other chemicals that would exert a mor 3,082,057 MANUFACTURE OF RAYQN Bernard F. Walker, Asheville, N.C., assignor to American Enka Corporation, Erika, N.C., a corporation of Delta ware No Drawing. Filed Feb. 9, 1962, Ser. No. 172,089 3 Claims. ((31. 18—54) This application is a continuation-impart of applica tion Serial No. 61,039, ?led June 9, 1960, which in turn is 1a continuation of application Serial No. 678,766, ?led ‘ August 19, 1957, now abandoned. This invention relates to the production of shaped articles of regenerated cellu desirable effect than the known additives. Along this lin it was found that yarn properties are enhanced in a mo: favorable manner when the viscose is spun in the presenc of ethoxylated amines such as those disclosed in US Patent No. 2,572,217 and quaternary derivatives of suc ethoxylated primary amines. However, when using these types of ethoxylated amine and their derivatives, foaming problems were encountere when the additive was incorporated during the dissolvin of the xanthate crumbs and additionally, the viscose cor taining the additive was very dif?cult to deaerate. Another phenomenon that was observed was that th viscose containing the additive became cloudy sever; lose from viscose and more particularly to the produc tion of specially modi?ed high tenacity viscose rayon yarn 15 hours after the modi?er was added to the viscose. A; and rayon tire cord having physical properties superior patently, a reaction occurs between the viscose and th to normally modi?ed yarn and cord. modi?er which may be either physical or chemical an which produces objectionable products that may be eithe Due to extensive research being conducted by various soluble, giving clear viscose, or insoluble, giving cloud rayon manufacturers, improvements in the physical prop erties of rayon are being made constantly. Although vis 20 viscose. It seems likely that the by-products of this reac cose rayon y-arn possesses many qualities that make it especially suitable for use in reinforcing rubber articles such as cord tires and the like, there is a continuing need to improve the strength and resistance to ?ex fatigue of tion are produced at a steady rate commencing as 500 as the viscose and the modi?er are mixed. It would als seem probable that the sudden development ‘of cloudines is only incidental and may occur at the time when th the yarn. In recent years a most signi?cant technological 25 concentration of reaction products suddenly reaches th limit of their solubility in the viscose. There are thu advance in improving the tenacity and ?ex life of viscose rayon yarns resulted from the discovery that certain two probabilities, either (a) soluble, harmful reactio chemicals under particular spinning conditions modify products present in the viscose from the moment of mi) and retard the regeneration of cellulose after extrusion. ing, increasing in concentration with time; and (b) it soluble, harmful reaction products which develop some time after mixing, which apparently induce the form: These chemical additives which improve the physical properties of the yarn have become known in the art as viscose modi?ers. Modi?ers that are already disclosed in the prior art include, for example, certain aliphatic and aromatic monoamines, quaternary ammonium compounds, and N-substituted dithiocar-bamic acids having speci?c solubilities (U.S. Patents 2,535,044—5, 2,536,014, and 2,696,423). The mechanisms by which a modi?er changes the nor mal spinning process have not been de?nitely established, although several theories have been advanced in this con nection. However, the modi?ed yarns have characteris tion of voids discussed above. In an effort to overcome these problems, and mor particularly the foaming and deaeration problems, th modi?er was injected into the viscose just prior to spit ning the viscose. The aforesaid problems were effective ly overcome but, what was quite unexpected, the physicz properties of the cord made from the yarn were signi?can' ly improved, especially in regard to strength withot sacri?cing resistance to ?ex fatigue, as will be shown hert inafter. The injection method apparently circumvent tics which are readily distinguishable over normal yarn. the harmful effect of by-products whether soluble or it crenulations. At the same time, it was found that a modi creased. Heretofore the point at which the modi?er was adde to the spinning process was not considered critical as ion as the additive was present when the viscose was extrude soluble. The primary bene?t of using the injection sy: At ?rst, investigators discovered that cross sections of the tem seems to be that the strength of the cord is signi?can' ?laments produced under the influence of'a modi?er show that the ?laments have a surface with notably reduced 45 1y improved, or in other words, the cording loss is Cit - ?ed yarn has a very different skin and core structure which could be observed by viewing stained cross sec tions of the yarn under a microscope. A modi?ed yarn, 50 into the setting ‘bath. The prior art suggested very gene] it was seen, has a greater proportion of skin to core, as compared with yarn formed by the conventional methods. In observing the skin structure of a modi?ed yarn, an other visible characteristic was always associated with modi?ed yarns. Dark spots could be seen throughout the ally that the modi?er could ‘be added to the setting bat] to the viscose, or in almost any stage in the productio of viscose. The primary considerations in this resper were the stability and solubility of the modi?er with se< 55 ondary attention given to improvements in the physicz cross sectional area of the yarns when cross sections of properties of the yarn. modi?ed yarns were stained and viewed under a light microscope. Initially, no explanation could be given for On the contrary, by the present invention it has bee these dark spots, which later became known as “freckles.” found that the time at which the modi?er is added t Subsequently, it was discovered by observing longi tudinal sections of modi?ed yarns under an electron mi croscope, that the ‘so-called freckles were in fact tiny voids or cavities in the yarns. Generally, the voids are elliptical in cross section with the long axes thereof par alleling the yarn axis which indicated that the voids are the viscose spinning system is highly important to produc a modi?er yarn which forms superior cords. It has no‘ been discovered that by adding the modi?er to the viscos spinning solution shortly before it reaches the SPlIlIlCTv‘ and thereafter spinning the viscose, improved proces ability and improved physical properties of the cord a1 present prior to the stretching of the yarn, because 65 obtained. In addition to avoiding the foaming and deaer: tion problems and improving the strength and resistant stretching orients and elongates the voids. Accordingly, it was thought that the effectiveness of viscose modi?ers was somewhat related to the formation of the voids within the freshly spun yarn in View ‘of the fact that the voids 70 were always present in the known modi?ed yarns. to ?ex fatigue, a brighter yarn is produced by the prese1 invention. Furthermore, the yarn of the present inventic very surprisingly is substantially free from the voids : After the discovery that certain chemicals modify the regeneration of cellulose, research work was directed to It is' an object of the present invention to provide process for manufacturing high tenacity modi?ed regel discussed above. 3,082,057 4 :rated cellulose yarn from viscose thatforms cords of viewed under an electron microscope. Furthermore, the yarn has a brighter luster than normally modi?ed yarn. A further understanding of the process and the novel yarn of this invention will be obtained from the following speci?c examples which are intended to illustrate the present invention, but not to limit the scope thereof. EXAMPLE I Alkali cellulose prepared from wood pulp was aged mproved physical properties as compared with known nodi?ed yarn cord. An additional object is to provide a high tenacity, highly atigue-resistant modi?ed cord that is characterized by he substantial absence of voids normally present in modi ied yarns. Other objects and advantages will become apparent rom the following detailed description. These objects are accomplished by incorporating in the 10 in a known manner. This alkali cellulose Was then xanthated with 37.7% carbon disul?de, based on the 'iscose a modi?er at a time not too remote from the weight of the cellulose. The xanthate crumbs so produced pinning of the viscose into a setting bath. Compounds were dissolved in a solution of sodium hydroxide of a pre generally suitable for use in accordance with the present determined strength to produce a viscose having 7.5% nvention are those additives which, when added to a vis ‘ose solution in sufficient amounts, retard the subsequent 15 cellulose and 5.7% sodium hydroxide. During the dis solving process a viscose modi?ed, namely the methyl egeneration of the cellulose but during ripening of the chloride quaternary derivative of an ethoxylated coconut 'iscose will normally form a cloudy viscose solution. In oil amine having the general formula: .ddition, these compounds may be distinguished by the act that they tend to induce aeration and foaming in the (CHZOHZO) :H 20 'iscose. R—N+ o1 Among the compounds suitable in the practice of the égwlizCHzOhH >resent invention are those described in application Serial ~10. 609,792, now abandoned, and in said U.S. Patent ~10. 2,572,217. in which formula x plus y=approximately l5 and R is a These compounds have the general saturated hydrocarbon radical containing 8—l8 carbon 25 atoms, was added in the amount of 2.5% based on the ormula: cellulose content. (GDHZHOLH R1—N+ 1Itz\(CuH2nO)yH Foaming was noticeable in the dis— solving operation; and the viscose could not be ef?ciently Z deaerated in the usual vacuum deaerating tanks. It was observed that the viscose became somewhat turbid after about four hours. vhere R1 and R2 represent preferably an alkyl radical The viscose, after being properly ?ltered and aged, was rut may include an aryl or alicyclic radical with R1 pref rably being an alkyl radical containing six or more arbon atoms and R2 being an alkyl radical containing me to three carbon atoms; Z represents an anion having ubstantially no surface activity such as hydroxide, halide, primary setting bath containing 4.8% sulfuric acid, 13.7% ulfate, acetate, etc.; x and y are whole numbers of at east one with the preferred combined value of x and y icing 2 to 50 more, depending on the purpose for which a high stretch in a second bath having the composition of 4.0% sulfuric acid, 4.0% sodium sulfate, and 0.7% zinc sulfate, said bath being maintained at 93° C. The yarn spun into yarn by extruding it through a spinneret into a Na2S-O4 and 4.0% ZnSO4. The temperature of the bath was maintained at 65° C. Thereafter the yarn was given he additiveis used; 11 is also a whole number, possibly 40 was aftertreated in a conventional manner. The conditioned and wet strength values of unslashed me but preferably two or no more than four. These qua singles of the yarn so produced were respectively 411 :rnary derivatives of ethoxylated primary amines are g/ 100 denier and 305 g./100 denier. Singles given a nown in the trade as “Ethoquads.” ' 10% slashing stretch had a conditioned strength of 445 The compounds of U.S. Patent No. 2,572,217 are known g./ 100 denier and a wet strength of 321 g./100 denier. 1 the trade as “Ethomeens” and are reaction products of The slashed singles were plied into the tire cord con mg chain aliphatic primary amines with ethylene oxide, struction seen in Table I wherein physical properties 1e reaction being represented generally as follows: thereof are given. (CnH2nO) :11 Table I ENE: + (z + wonmno —> RN (0 uHZnO) 11H 11 the above formula, R represents an aliphatic chain aving from 8 to 24 carbon atoms therein and preferably rom 12 to 14 carbon atoms. Cord construction x or y is at least one, nd x plus y is the total number of alkylene oxide chains 55 lhlClZl may be as low as 5 without any de?nite restriction n the upper limit, although 12 to 18 or about 15 have een found to be quite effective, and n is a small whole umber from 2 to 4, both inclusive. A preferred method of adding the modi?er to the vis ose is by injecting predetermined amounts, e.'g. 1.0% 11.4 x 10 6 Denier ............................... .. 3, 613 Conditioned strength, lbs ___________ ._ 30. 6 Conditioned strength, g./100 den _ . _ _ __ 384 Oven dry strength, lbs _________ __ _ 36. 4 Oven dry strength, g./l00 den _________ __ 457 Firestone fatigue, hrs. _._ 12 x 12 12/11 _._ The yarn appeared to be dull and milky when observed on a yarn viewing card. Cross sections of the yarn when 60 stained and viewed under a light microscope showed the ifreckles as described above. By viewing longitudinal .0% , of the material based on the weight of the cellulose no a ?owing stream of viscose by any suitable type of sections of the yarn under an electron microscope, it was noted that the yarn had many voids within the yarn. ijection system, such as that shown in application Serial EXAMPLE II 10. 655,004, ?led April 25‘, 1957, now Patent No. 65 329,731, and having common ownership‘ herewith, A viscose was prepared in the same manner as de aoroughly mixing the viscose and modi?er and thereafter pinning the mixture in a conventional manner. The yarn produced by the present invention is par .cularly characterized by the fact that it is substantially ll skin modi?ed viscose rayon yarn having tenacity and atigue resistance in a cord construction superior to ormally modi?ed yarn and further characterized by a ubstantial absence of freckles when viewed under a light iicroscope and a substantial absence of voids when scribed in Example I with the exception that the viscose modi?er was not added during the dissolving of the xanthate crumbs. In the present example, a 6.4% aque ous solution of the additive used in Example I was in jected into the aged, ?ltered and deaerated viscose being pumped to the spinnerets through a conduit. Between the point of injection and the spinneret, the viscose con taining the additive was continuously mixed in a blend ing device provided with internal mixing means. 8,082,057 5 6 The viscose was extruded into a primary bath having the same composition as in Example -I. The yarn was stretched, passed through a second bath, and aftertreated ?cations may be made in the methods of procedure with out departing from the spirit of the invention. What is claimed is: 1. In a method of producing a high tenacity modi?er in the manner also described in Example I. The conditioned and wet strength values of unslashed viscose rayon yarn involving the use of a type of modi?e singles of the yarn so produced were respectively 395 which when added to the viscose solution in the re g./ 100 denier and 310‘ g./€100 denier. Singles given a quired amounts will normally induce aeration and foam 10% slashing stretch had a conditioned strength of 460 ing therein, the improvement that comprises injecting 1.0L g./100* denier and a Wet strength of 325 g_/100 denier. 6.0%, based on the weight of the cellulose in the viscose The slashed singles were plied into the tire cord con 10 of a modi?er of the class consisting of ethoxy-lated amine struction seen in Table II wherein physical properties and quaternary derivatives thereof, into a ?owing strean thereof are ‘given. of normally ripened viscose just prior to spinning, pass ' Table II Cord construction Denier _______________________________ _ _ 11.4 x 10 6 12 x 12 3. 565 3, 657 Conditioned strength, lbs ...... __ 31.6 30.1 Conditioned strength, g./100 den 402 373 s _____ _. 37.6 35. 3 Oven dried strength, g./lOO den 478 440 Oven dried strengt , Firestone fatigue, hrs_ 12/11 ______ __ __ 4. 5 An analysis of the data given in the tables showing a highly signi?cant improvement in the cord strengths of the yarn produced by injecting the additive into the ripened viscose as compared with the yarn produced by incorporat ing the additive during the dissolving operation. ing the mixture into a blending zone, and before anj objectionable aeration and foaming can occur in the vis 15 cose solution, directly extruding the same into a coagul-at ing bath to ‘form yarn therefrom. 2. In a method of producing a high tenacity modi?er viscose rayon yarn involving the use of a type of modi ?er which when added to the viscose solution in the re quired amounts will normally induce aeration and foam ing therein, the improvement that comprises injecting 1.0 6.0%, based on the Weight of the cellulose in the viscose of an ethoxylated amine into a ?owing stream of normally ripened viscose just prior to spinning, passing the mixturi 25 into a blending zone, and before any objectionable aera tion and foaming can occur in the viscose solution, di rectly extruding the same into a coagulating bath to forn The yarn produced in the present example had a yarn therefrom. bright, lustrous appearance when observed on a yarn 3. In a method of producing a high tenacity modi?e< viewing card. The spinnability of the viscose was im 30 viscose rayon yarn involving the use of a type of modi?e proved and the viscose was very clear when extruded. which when added to the viscose solution in the requiret Cross sections of the yarn, when stained and viewed un amounts will normally induce aeration ‘and foaming der a light microscope, were practically free of freckles therein, the improvement that comprises injecting 1.0 and had a homogeneous skin structure. By viewing 60%, based on the weight of the cellulose in the vis longitudinal sections of the yarn under an electron micro 35 cose, of a quaternary derivative of an ethoxylated amini scope, substantially no voids were noticed within the into a ?owing stream of normally ripened viscose jus am. y The yarn had a high degree of molecular orientation as prior to spinning, passing the mixture into a blending zone, and before any objectionable aeration and foam ing can occur in the viscose solution, directly extruding determined by X-ray diifraction measurement. Although high orientation is characteristic of high tenacity but 40 the same into a coagulating bath to form yarn there ordinarily brittle yarn, it was surprising that such proper ties would be present in the yarn of the instant inven tion, especially in view of the fact that the present yarn is not brittle but is highly resist-ant to flex fatigue. While the speci?c examples of the preferred methods embodying the present invention have been set forth above, it will be understood that many changes and modi we from. References Cited in the ?le of this patent UNITED STATES PATENTS 1,823,769 2,758,004 ‘Stokes ______________ .__ Sept. 15, 193 Tallis et al ____________ __ Aug. 7, 195"