US2373712A - Viscose production - Google Patents

Description

April 17, 1945. P. H. SCHLOSSER ETAL 2,373,712

VISCOSE -BRODUCIION Filed April 19, 1943 PAUL HENIZY SCHLO55EIZ KENNETH RUSSELL GIZAY nNvenTons ATTORNEYS Patented Apr. 1?, was

VISCOSE PRODUCTION Paul Henry Schlosser and Kenneth Russell Gray,

Shelton, Wash, assignors to Rayonler incurporated, San Francisco, Calif., a corporation of Delaware Application April 19, 1943, Serial No. 483,663

12 Claims. (Cl. 105-166) Our invention relates to improvements in viscose production. More particularly our invention relates to an improved method of dispersing, in the presence of certain cation active compounds as herein described, a non-miscible opacifying agent in viscose formed of a cellulosic material preferably containing not more than 0.15% of naturally occurring ether extractable material.

A primary object of our inventionis the provision of an improved method of dispersing opacifying agents in viscose, especially in a viscose spinning solution. We have made the discovery that we may obtain improved dispersion or emulsification of opacifying agents in viscose by incorporating the agents of our invention or discovery in the viscose by adding them at a stage in the viscose process subsequent to the completion of xanthation and prior to or during the step of dispersion or emulsification. Such incorporation may include, for example, addition (a) after completion of xanthation during the step of dissolving the cellulose xanthate in dilute caustic soda to form viscose, (b) to the cellulose xanthate before dissolving to form viscose, (c) to any of the materials being mixed with the cellulose xanthate to form viscose, (d) directly to the viscose, (e) to the opacifying agent or (f) to other materials being added to or being mixed with the viscose either prior to or during the step of dispersing or emulsifying opacifying agents in the viscose. Hereinafter when it is stated that the agents of our invention or discovery are present in the viscose by incorporating them during the viscose process subsequent to the completion of xanthation, it is meant that such of our agents may be added in any of the ways set forth'above, unless the context definitely requires a more limited construction.

Figures 1, 2 and 3 are photomicrographs illustrating the invention herein.

In the spinning of delustered filaments, for example, it is customary to disperse a liquid opacifying agent such as mineral oil or pine oil or a pigment such as titanium oxide or both, or other oleaginous or'solid non-miscible materials in the viscose. In the case of liquids or semi-liquid materials such as mineral oil, pine oil or petroleum ness. Providing fineness of dispersion is only the first part of the problem. This would be ofno avail if the solution did not also possess the necessary stability. Our discovery or invention provides dispersions of the character set forth, characterized not only by their uniform fineness of dispersion but also their extreme stability, so that they do not deteriorate during the period elapsing between the time of emulsification and spinning, a period which may be of the order of several days.

Normal dissolving pulps in present use consist mainly of cellulose but contain appreciable amounts of non-cellulosic impurities such as' hemicelluloses, fats, resins, waxes, etc. One of the main objects in the manufacture of a satisfactory dissolving pulp is to remove as much as possible of the non-cellulosic impurities so that a whiter pulp results which is capable in general of producing a high grade yarn.

We have found that not all of the non-cellulosic materials which can be removed are undesirable as regards the properties of the viscose which may be manufactured from the pulp and in fact certain of such impurities normally present in small amounts are highly beneficial. These beneficial impurities for the most part are surface active materials of the anion active class or materials which can give rise to the production of such surface active materials during the processing of pulp into viscose. In a pulp which has not been highly refined, these substances which are of the nature of fats, fatty acids, resins and waxes, constitute a portion of the materials which a pulp from which all undesirable materials had been removed but which still retained the natural materials promoting good emulsification. practice, such a clean-cut separation is difficult to accomplish directly. We have discovered that better results are obtained by preparing viscose from pulp from which most or all of the undesirable materials have been removed without regard to retention of the beneficial portion of natural emulsifiers and to add to the viscose either prior to or during emulsification a class of materials which we have discovered to have a far better emulsifying action than the natural emulsifiers present in unrefined pulp.

White, highly purified or refined wood pulp are very advantageous for the production of high grade rayon yarns of superior strength and color and for this reason, are highly esteemed by the trade. Such highly refined wood pulps are in general chemically prepared pulps characterized by having an ether extract of about 0.15% or less where such percentage refers to the amount of natural ether extractable material left in the pulp after the purification processes, or where such low ether extract results during the process of manufacture. While our invention is particularly applicable to such highly refined pulps contain ing not more than 0.15% of ether extractable material, part of the advantages of the invention may be obtained when it is applied to the emulsification of normal dissolving pulps containing substantially more than 0.15% of ether extractable material, although such pulps do not generally yield the highest grade yarns and although their emulsification with oils is not usuall accompanied by as great difficulty as when using the more highly refined pulps.

We have made a very important discovery in that we find that very substantial improvements in the emulsification properties of viscose prepared from refined chemically prepared wood pulp can be obtained by adding either to the viscose itself or to the agents added to the viscose, in preparation for emulsification or during emulsification, materials of an entirely different class or nature from those surface active materials naturally present in the pulp in a pre-, dominating or effective capacity or which would be subsequently formed to an effective degree from materials originally present during the processing into viscose. These new materials comprise a special group of structurally related cation active compounds.

These compounds of the invention also we find greatly improve the emulsification properties of viscose prepared from cotton linters when the agents or materials of our invention or discovery are added to the said viscose itself or incorporated during the viscose process subsequent to the completion of xanthation as herein set forth. Refined cotton linters of the grade normally used in rayon manufacture are almost entirely free from natural emulsifying agents found in appreciable amount in wood pulp of a low degree of purity and to a much smaller extent in highly refined pulp.

We are aware that it has been heretofore proposed to add anion active materials to viscose in order to promote better emulsification with oily liquids or dispersion of insoluble pigments. When anion active materials are used as emulsifying agents in similar concentrations to that contemplated by our invention, some benefit is obtained in that the average size of the oil particles is lessened. Such emulsions, however, even though possessing a smaller average particle size than if no emulsifier were added are nevertheless not in general very uniform in regard to particle size. For example, using a typical anion active material, the great majority of the oil particles, after the emulsion has stood for some time, might not be larger than 2 or 3 microns, but there also will usually be an appreciable number of rather large globules ranging up to microns or considerably larger. These larger particles even though relatively few in number can readily cause breaking of filaments or at least a weakening of the yarn. In short, the presence of a few large globules will be detrimental to a degree out of all proportion to that indicated by their number.

We find with the great majority of cation active materials when they are added to the viscose itself or incorporated in the viscose as set forth herein, emulsification results are in the main approximately of the same order as those obtained by typical anion active materials. When however using the special subclass of cation active agents of our discovery and adding them as herein set forth, the results are strikingly different. A characterizing feature of our invention when applied to the emulsification of oleaginous materials, even after the emulsion has stood for a considerable time, is not only a very small average size of the oil particles, but in addition a striking uniformity of particle size and when the invention is carried out under optimum conditions, a remarkable absence of even small proportions of globules considerably larger than the main particle size.

Thus, in accordance with our invention, we are able to prepare emulsions of mineral oil and the like in viscose characterized by an extraordinary fineness and uniformity of particle size and a stability heretofore unobtainable. The result is ogtained through the use in the viscose of very small quantities of a cation active quaternary ammonium compound of a particular group or class. These compounds producing the extraordinary fine and stable emulsions of our invention are cation active quaternary ammonium compounds which are characterized by having not only a long chain hydrocarbon group attached to the nitrogen and which apparently induces surface activity, but also by having in close proximity to the nitrogen atom, a saturated aliphatic ring. By close proximity is meant that the nitrogen atom may be actually a part of the ring or may be directly attached to the ring. The aliphatic ring structures are either of a hydrocarbon nature, or, in the case where the nitrogen is part of the ring, of a hydrocarbon nature exceptfor the heterocyclic nitrogen atom.

More particularly, this class of compounds may be defined as quaternary ammonium compounds which have the following general formula:

wherein R is a straight chain hydrocarbon radical containing '7 to 20 carbon atoms, wherein X is an anion, wherein at least one of the three free nitrogen valences is connected to a radical of the group consisting of (a) a cycloalkyl hydrocarbon radical and (b) an alkylene hydrocarbon radical attached to two of the valences thereby forming a ring, and wherein the remaining valence or valences are each connected to a hydrocarbon radical containing from 1 to 6 carbon atoms.

In the more preferred forms of the general formula given above the cycloalkyl hydrocarbon r: iical will be a cyclohexyl radical, while the alkylene hydrocarbon radical attached to two of the valences thereby forming a ring will be a pentamethylene radical attached to the nitrogen to form a piperidinium compound.

Two specific examples of c mpounds of this class producing very remarkable emulsification results are lauryl methyl piperidinium bromide and lauyryl dimethyl cyclohexyl ammonium bromide. It will be understood that the anion, in this case, bromide, is not of particular consequence since it does not impart surface activity. Such anion could be any innocuous anion such as chloride, iodide, sulphate, bisulphate, methyl 2,373,712 sulphate, hydroxide, etc. Formulae representin these specific examples are: r

H2 I C While the two compounds shown above, which are the preferred compounds of our invention, or discovery, have lauryl groups attached to the nitrogen atom, it is to be noted that good results are also obtained when using instead of lauryl groups, any other normal primary aliphatic hydrocarbon radical, either saturated or unsaturated, within the range from 7 to 20 carbon atoms. However, be it noted, that our preferred range is from 12 to 18 carbon atoms. Commercially, the main sources of such normal primary aliphatic hydrocarbon radicals are the vegetable and animal fats and oils. Such fats or oils may be utilized in preparing the compounds of our invention or discovery, for example by catalytic reduction by hydrogen to the fatty alcohols which may then be converted to alkyl halides or other alkyl esters according to well-known practices. The alkyl halide or halides (or other alkyl ester) then may be reacted with the proper tertiary amine or aminesto give whatever quaternary ammonium compound or compounds of the invention may be desired. In preparing the compounds used in the invention, it is not necessary to use pure alkyl halides. Indeed, higher molecular weight alkyl halides prepared as indicated from fats and oils are generally, if not always, offered in commercial quantities in the form of mixtures of different hydrocarbon chain lengths. Thus, for example, in place of using pure lauryl bromide in the preparation of lauryl methyl piperidinium bromide, technical lauryl bromide, that is, such as may be prepared from technical lauryl alcohol may be used. Such technical lauryl bromide will be essentially a mixture of C8, C10, C12, C14, and C16 carbon length chains with the C12 (i. e., the lauryl chain) predominating. Methyl piperidinium quaternary ammonium salts prepared from such technical mixture of alkyl bromides function in our invention or discovery, we find, in a substantially identical manner as quaternary ammonium piperidinium salts of the individual pure bromides. Actually, however, when using such a mixture in which lauryl bromide predominates and containing both lower and higher chain lengths the result is almost the same as if pure lauryl bromide were used. Also, it is obvious that in many cases alkyl chlorides will be used in preparing the compounds rather than bromides in view of the lesser cost of the chlorides.

In the case of preparing the cyclohexyl ammonium compounds of the invention, the long chain hydrocarbon radicals may be introduced into the molecules either by long chain alkyl esters (generally the halides) or by long chain amines. Even in the latter case, the normal primary aliphatic hydrocarbon radical will be often derived from the fats and will thus be frequently used in the form of mixtures of chainlengths. In preparing the compounds of our invention or discovery, substantially equimolar quantitie of alkyl halides and tertiary amines (in the case of mixture based on halogen and nitrogen contents respectively) will be used. Thus, for practical reasons, it will be understood, that in many cases the final product will contain a relatively small proportion of unreacted alkyl halide or halides. It has been found, however, such resulting products may be satisfactorily used in our invention herein.

Furthermore, we have found that we can satisfactorily employ the quaternary ammonium compounds of our invention when they contain as impurity small proportions of unreacted tertiary amine. In the case of amines which are appreciably volatile and characteristically odoriferous, we prefer to substantially eliminate the unreacted amine before using the resulting product in the viscose process. We find that this may be successfully and very simply accomplished by adding to the resulting product at the termination of the reaction, an appreciable proportion of Water, which might, for example,

be 10% or more, but in any event is added in at least sufficient quantity so that the mixture will be fluid at temperatures of about 100 C. or higher. The mixture is then heated, preferably while stirring, until substantially the greater part of the added water is driven off, or until a sufiipient portion of such water is driven off to carry away in the vapor all objectionable odor. It is recognized that in some cases for convenience of handling it will be found desirable to have a liquid product. In such cases enough water can be initially added so that after driving off substantially all the unreacted amine, there still will remain sufiicient water to provide a product which will remain liquid on cooling.

Other specific examples of the compounds of our invention which have given especially good 1 results are:

Lauryl methyl piperidinium chloride Lauryl methyl piperidinium iodide Oleyl methyl piperidinium bromide Lauryl ethyl piperidinium bromide Lauryl propyl piperidinium bromide Oleyl dimethyl cyclohexyl ammonium bromide The percentages of cation active compounds mentioned herein and in the claims are based on the cellulose content of the viscose. The effectlve range of the special group of compounds used in the method of our invention has been found to be from 0.01% to 2.0%, and preferably from 0.08% to 0.2%. With 0.01% .some of the improvements of our invention begin t manifest themselves and this efiect increases rapidly as the concentration is increased up to about 0.08% and thereupon the eifect increases less rapidly but still noticeably until the concentration is increased up to about 0.20%. Let it be noted that our invention contemplates preferably the use of a concentration range of the agents of our discovery from 0.08% to 0.20% in conjunction with viscose solutions prepared from cellulose especially refined chemical wood pulp containing not more than 0.15% of ether extractable matter. Thereafter, with wood pulps having ether extracts within the preferred limits, i. e., less than 0.15%, as the concentration is further increased above 0.20%, the

oegree or improvement in emulslfication isextremely small, or none at all. When the addition of our agents reaches the point oi! 0.2% certain disadvantages begin to manifest themselves and.

2.0% is reached theu se of the product or agents of our invention in such high concentrations becomes substantially prohibitive, and thus the exact determination of when the very definite upper limit respecting improvement in emulsiflcation is reached becomes purely academic or theoretical.

In order to obtain strikingly improved emul sions according to the process of the invention, preliminary experimenting is not necessary. If, however, it is desired to obtain the optimum of results with the most economy in the matter of added agents of our invention, we find that some preliminary experimenting may be desirable. We have discovered that this is a result of the fact that the cmpositions of the ether extracts of pulps vary somewhat as regards different species of wood, as re ards wood from different sections ofthe country L :l, in the matter of a single type of wood, even from season to season. In particular the ether extracts vary somewhat as regards their content of natural anion active materials or of materials which can give rise to natural anion active materials.

As regards emulsification, in order to obtain 2 substantially complete uniformity (that is, absence of even small proportions of globules considerably larger than the size of the great majority of particles), it is necessary to'have the effects of the added cation active agents of the invention predominate aver'the natural anion active materials present. (The predominance of the latter tends to give a more irregular type of emulsion which seems to be characteristic of anion active materials.) Thus while the preferred range for adding the agents of our discovery is 0.08%-0.20%, the exact amount within this range which it will be most advantageous to use, considering both the quality of the emulsion and the economy of the process, will depend somewhat on the amount of ether extract and to a smaller extent on its composition. It is in view of the latter fact that some preliminary experimenting may be desirable. In general, however, when the ether extract of the pulp does not exceed the upper limit of the optimum range 0.04%-0.09% it will usually be most advantageous from the standpoint of economy to make addition of the compounds of the invention in amounts toward the lower portion of the preferred range of 0.08 %-0.20%. When, however, the ether extract is in the neighborhood of the upper limit of the preferred range for pulp, that is, around 0.15%, in many cases it will be desirable to add the compounds of the invention in amounts approaching the upper limits of the preferred range, that is, in amounts approaching 0.20%. When using pulps having higher ether extracts than the .15% upper limit of the preferred range of ether extracts, one advantage in adding up to 2.0% of the agents is the insurance of the elimination of all relatively large globules.

Though it is practical to' add the compounds in amounts, by weight, up to 2.0%, such percentage being based on the weight of the bone dry pulp,

while obtaining in part the advantages of the invention, we believe that in most' cases better results will be obtained by using pulps within the preferred range of ether extracts (i. e., less than 0.15%) and the agents in the preterred'range of 0.08%-0.20%. The use of such smaller concentrations is not only more economical but, in most cases, in addition to avoiding the difficulties outlined above will give better spinning and a better yarn. I

The compounds of the inventlonmay be incorporated in the viscosein any suitable manner as hereinabove more fully set forth. They may, for example, be added directly to the viscose or added to any one or more of the materials which enter the viscose. A very practical point of adding the compounds is after completion of xanthation during the step of dissolving the cellulose xanthate in dilute caustic soda to form viscose. The compounds may be added to either the charge of water or the charge of strong caustic soda solution which is mixed with the cellulose xanthate, or the compounds may be added directly to the viscose mixing apparatus either as aqueous solutions or in the undiluted state. They may be added either prior to adding the opacifying agent or simultaneously with the opacifying agent. The actual step of dispersing the opacifying agent may also be carried out in the viscose mixer or according to any of the other usual methods normally employed in the art. It could, for example, carried out after forming the viscose as a separate operation at any time prior to spinning. When the compounds of our invention are used in the preferred concentration range, i. e., 0.08% to 0.20%, with viscose prepared from pulp of high ether extract, i. e., above 0.15%, the emulsions generally no longer have the uniformity that is a characterizing feature of our invention. The average particle size of the dispersion may still be fairly small but there generally will be an appreciable number of larger globules up to 10 miowns or more. Presumably this i because the anion active material in the ether extract is in excess, and the result obtained is thus characteristic of the result obtained when using ordinary anion active materials as an aid to emulsiflcation.

In general as has been pointed out, our invention is preferably used with viscose prepared from refined wood pulp having naturally occurring ether extracts up to 0.15%. There is, however, an optimum range of ether extracts which is approximately 0.04% to 0.09%. If the ether extract of the pulp used in preparing the viscose is extremely low, that is, below 0.04%, the use of the compounds of our invention will still produce dispersions of fine particle size showing the striking uniformity characteristic of our invention. The average particle size, however, will not be quite as small as if an equal amount of one of the quarternary ammonium compounds of the invention were added to viscose prepared from pulp having a little higher ether extract.

In the practice of our invention or discovery,

' in order to obtain the best emulsions, that is, disespecially when the ether extract of the pulp used does not exceed the upper limit of the optimum range of 0.04%0.09%,

of the group consisting of a cyclohexyl hydrocarbon radical and a pentamethylene hydrocarbon "The dispersion of opacifying agents in viscose according to the invention is remarkably efiective. In the emulsification of oleaginous agents, for example, not only is the average size of the dispersion extremely small, but the emulsion, even after standing a number of days, is exceedingly uniform in that the usual small number of larger globules is completely absent. For example, adding 0.1% lauryl methyl piperidinium bromide to viscose hich had been prepared from refined chemicall prepared pulp containing 0.07% ether extractable matter and then emulsifying the viscose with white mineral oil, even after three days standing, the emulsion had an average particle size of less than a micron with no particles at all above 2 microns.

Where percentages are referred to herein as to the range in which the agents of our invention 01' discovery are to be added or in referring to the percent of ether extract present said ercentages refer to weight and are based upon the cellulose content of the viscose.

In the drawing Figures l, 2 and 3 are photomicrographs. under identical magnification, of emulsions of white oil, i. e., liquid petrolatum, in viscose, all made after the emulsions had stood '12 hours. In all the figures one small division of 'the scale represents 3.6 microns.

Figures 1 and 2 are views of an emulsion obtained without the addition of any emulsifying agent and using viscose prepared from a refined chemical pulp containing 0.04% of ether extractable matter. Figure 1 is a view indicative of the range of sizes of the majority of the oil particles. while'Figure 2 is a view showing some of the smaller proportion of considerably larger oil particles also present in another part of the slide. Figure 3 is a view of an emulsion prepared from the same viscose sample as used for Figures 1 and 2, but to which was added prior to'emulsification 0.15% (based on the cellulose content of the viscose) of a higher alkyl methyl piperidinium bromide in accordance with the invention. The higher alkyl radical in the compound was derived from the mixture of hydrocarbon radicals obtained by hydrogenation of coconut oil and predominating in the lauryl group. Only the one view (Fig. 3) of this emulsion is shown, since, due to the remarkable uniformity. a single view is typical of the whole emulsion in view of the complete absence of particles considerably larger than the sizes of the great majority of the oil particles.

We. claim:

1. In' the viscose process in which a non-miscible opacifying agent is dispersed in viscose prepared from cellulosic material having not more than 0.15% of naturally occurring ether ex- -tractable matter, the improvement which comprises dispersing the opacifying agent in viscose prepared from cellulosic material having not more than 0.15% of naturally occurring ether extractable matter, in the presence of a nitrogencontaining compound, which: is incorporated during the viscose process subsequent to the completion of xanthation, is present in a concentration ranging from 0.01% to 2.0% and has the general formula:

n-x i wherein R is a straight chain hydrocarbon radical containing 7 to carbon atoms, wherein X is an anion, wherein at least one of the three free nitrogen valences is connected to a radical radical attached to two of the valences thereby forming a ring, and wherein the remaining valence or. valences are each connected to a hydrocarbon radical containing from 1 to 6 carbon atoms, such percentages referring to weight and being based upon the cellulose content of the viscose. 1

2. In the viscose process in which a non-mis-' cible opacifying agent is emulsified in viscose prepared from cellulosic material having not more than 0.15% of naturally occurring ether extractable matter, the improvement which comprises emulsifying the opacifying agent in viscose prepared from cellulosic material having not more than 0.15% of naturally occurring ether extractable matter, in the presence of 2. nitrogen-containing compound, which: is incorporated during the viscose process subsequent to the completion of xanthation, is present in a concentration ranging from 0.01% to 2.0%, and has the general formula:

wherein R is a straight chain hydrocarbon radical containing 7 to 20 carbon atoms, wherein X is an anion, wherein at least one of the three free nitrogen valences is connected to a radical of the group consisting of a cyclohexyl hydrocarbon radical and a pentamethylene hydrocarbon radical attached to two of the valences thereby forming a ring, and wherein the remaining valence or valences are each connected to a hydrocarbon radical containing from 1 to 6 carbon atoms, such percentage referring to weight and being based upon the cellulose content of the viscose.

3. Inthe viscose process in which a non-mis cible opacifying agent is dispersed in viscose prepared from cellulosic material having not more than 0.15% of naturally occurring ether ex- .tractable matter. the improvement which comprises dispersing. the opacifying agent in viscose prepared from cellulosic material having not more than 0.15% of naturally occurring ether extractable matter, in the presence of a nitrogencontaining compound, which: is incorporated during the viscose process subsequent to the completion of xanthation, is present in a concentration ranging from 0.01% to 2.0% and has the general formula:

' Gin-cu, x

. oI12cn i'n wherein R represents a straight chain aliphatic carbon radical of from '7 to 20 carbon atoms, wherein R1 represents a lower alkyl group and wherein X represents the radical of a mineral acid, such percentages referring to weight and being based upon the cellulose content of the viscose.

4. In the viscose process in which a non-miscible opacifying agent is dispersed in viscose prepared from cellulosic material having not more than 0.15% of naturally occurring ether extractable matter, the improvement which comprises dispersing the opacifying agent in viscose prepared from cellulosic material having not more than 0.15% of naturally occurring ether extractable matter, in the presence of a nitrogen-containing compound, which: is incorporated during the viscose' process subsequent to the completion oi xanthation, is present in a concentration ranging from 0.01% to 2.0%, and hasthe general formula:

cieu-cn,\ i i a cm c-N wherein R represents a straight chain aliphatic carbon radical of from 'L to carbon atoms, wherein R1 and R2 represent lower alxyl groups and wherein X represents the radical of a mineral acid, such percentages referring to weight and being based upon the cellulose content of the viscose.

5. In the viscose process in which a non-miscible opaciiying agent is dispersed in viscose prepared from refined chemically prepared wood pulp having not more than 0.15% of naturally occurring ether extractable matter, the improvement which comprises dispersing the opaclfying agent in viscose prepared from refined chemically prepared wood pulp having not more than 0.15% of naturally occurring ether extractable matter, in the presence of a nitrogen-containing compound, which: is incorporated during the viscose process subsequent to the completion of xanthation, is present in a concentration ranging from 0.08% to 0.20% and has the general formula:

CHr-CH: R1

wherein R represents a straight chain aliphatic hydrocarbon radical of from 7 to 20 carbon atoms. wherein R1 represents a lower alkyl group and wherein X represents the radical of a mineral acid, such percentages referring to weight and being based upon the cellulose content of the viscose.

6. In the viscose process in which a non-miscible opacifying agent is dispersed in viscose prepared from refined chemically prepared wood pulp having no more than 0.15% of naturally occurring ether extractable matter, the improvement which comprises dispersing the opacifying agent in viscose prepared from refined chemically prepared wood pulp having not more than 0.15% of naturally occurring ether extractable matter, in the presence of a nitrogen-containing compound, which: is incorporated during the viscose process subsequent to the completion of xanthation, is present in a concentration ranging from 0.08% to 0.20% and has the general'formula:

CBr-CHz\H Iii/R where R represents a straight chain aliphatic hydrocarbon radical of from 7 to 20 carbon atoms, where R1 and R2 represent lower alkyl groups and wherein X represents the radical of a mineral acid, such percentages referring to weight and being based upon the cellulose content of the matter, in the presence of a nitrogen-containing compound, which: is incorporated during the viacose process subsequent to the completion of xanthation,' is present in a concentration ranging from 0.08% to 0.2%, and has the general formula:

R-N i wherein R is a straight chain hydrocarbon radical containing 7 to 20 carbon atoms, wherein X is an anion, wherein at least one of the three free nitrogen valences is connected to a radical of the group consisting of a cyclohexyl hydrocarbon radical and a pentamethylene hydrocarbon radical attached to two of the valences thereby formcurring ether extractable matter, the improvement which comprises dispersing the opacifying agent in viscose prepared from refined chemically prepared wood pump having from 0.04% to 0.09% of naturally occurring ether extractable matter, in the presence of a nitrogen-containing compound, which: is incorporated during the viscose process subsequent to the completion of xanthation, is present in a concentration ranging from 0.08% to 0.20%, and has the general formula:

wherein R is a straight chain hydrocarbon radical containing 7 to 20 carbon atoms, wherein X is an anion, wherein at least one of the three free nitrogen valences is connected to a radical of the group consisting of a cyclohexyl hydrocarbon radical and a pentamethylene hydrocarbon radical attached to two of the valences thereby forming a ring, and wherein the remaining valence or valences are each connected to a hydrocarbon radical containing from '1 t 6 carbon atoms, such percentages referring to weight and being based upon the cellulose content of the viscose.

9. In the viscose process in which a non-miscible opacifying agent is dispersed in viscose preparedfrom cellulosic material having not more than than 0.15% of naturally occurring ether extractable matter, the improvement which comprises dispersing the Opacifying agent in viscose prepared from cellulosic material having not more than 0.15% of naturally occurring ether extractable matter, in the presence of a lauryl methyl piperidinium compound, which: is incorporated during the viscose process subsequent to the completion of xanthation, and is present in a concentration ranging from 0.08% to 0.20%, such percentages referring to weight and being based upon the cellulose content of the viscose.

10. In the viscose process in which a non-miscible opacifying agent is dispersed in viscose prepared from cellulosic material having not more than 0.15% of naturally occurring ether extractable matter, the improvement which comprises dispersing the opacifying agent in viscose prepared from cellulosic material having not more than 0.15% of naturally occurring ether extractable matter, in the presence of a lauryl dimethyl cyclohexyl ammonium compound, which: is incorporated during the viscose process subsequent to the completion of xanthation. and is present in a concentration ranging from 0.08% to 0.20%, such percentages referring to weight and being based upon the cellulose content of the viscose.

11. In the viscose process in which a non-miscible opacifying agent is dispersed in viscose prepared from cellulosic material having not mole than 0.15% of naturally occurring ether extractable matter, the improvement which comprises ranging from 0.01% to 2.0%, such percentages referring to weight and being based on the cellulosic content of the viscose.

12. In the viscose process in which a non-miscible opacifying agent is dispersed in viscose prepared from cellulosic material having not more than 0.15% of naturally occurring ether extractable matter, the improvement which comprises dispersing the opacifying agent in viscose prepared from cellulosic material having not more than 0.15% of naturally occurring ether extractable matter, in the presence of a cyclohexyl ammonium halide having the general formula:

dispersing the opacifying agent in viscose preeuro, X R

pared from cellulosic material having not more 15 g 1/ than 0.15% of naturally occurring ether exg T 011,411, in a,

tractable matter, in the presence of a piperidinium halide having the general formula:

wherein R represents a straight chain aliphatic hydrocarbon radical of from 7 to 20 carbon (1H2(.II2 X CH2 atoms, wherein R1 and R2 represent lower alkyl /l groups and wherein X represents a halogen radi- CHFCH cal, which cyclohexyl ammonium halide: is prewherein R represents a straight chain aliphatic arent from an alkyl halide, contains as impurity hydrocarbon radical of from 7 to 20 carbon a small portion of unreacted alkyl halide, is inatoms, wherein R1 represents a lower alkyl group corporated during the viscose process subsequent and where X represents a halogen radical, which to the completion of xanthation and is present in piperidinium halide: is prepared from an alkyl a concentration ranging from 0.01% to 2.0%, halide, contains as impurity a small portion of such percentages referring to weight and being unreacted alkyl halide, is incorporated during the based on the cellulosic content of the viscose. viscose process subsequent to the completion of 30 PAUL HENRY SCHLOSSER.

xanthation and is present in a concentration KENNETH RUSSELL GRAY.

CERTIFICATE OF COHREC TI ON Patent No. 2, 7 ,712.

PAUL HENRY SCHLOSSER, ET AL.

A 1-11f17, 19Li5.

It is hereby certified that error appears in'the printed specification of the above numbered patent requiring correction as follows: Page 2, sec- 0nd column, line 70, for "lauyryl" read. -'--laury1--; page 3, first oolumn, line 57, for "such" read "such a--; and second column, line 7, for "mixture"- read "mixtures-1.; page )4, second column, line 32 before carried insert --be--; page 5, fir t column, line 20, after the word "present" insert a comma; and second column, line 38, claim 2, for "percentage" read --percentages--; page 6, first column, line hi claim 6, for "no more" read -not more"; line 60, same claim, for "where" read -wherein and second column, line 29, claim 8, for "pump" read --pulp--; page 7, second column, line 25, claim 12, for "parent" read "paredand that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office;

Signed and sealed this 7th day of August, A. D. 1915.

Leslie Frazer Acting Commissioner of Patents.

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