US2822237A - Process for producing filament of vinyl chloride polymer - Google Patents

Description

Feb. 4, 1958 HIROSHI IWAMAE 3 PROCESS FOR PRODUCING FILAMENTS OF VINYL CHLORIDE POLYMER Filed Feb. 21, 1955 INVENTORQ h zws/lr IwAMA E United States Patent PROCESS FOR PRODUCING FILAMENT OF VINYL CHLORIDE POLYMER Hiroshi Iwamae, Nishiki-machi, Iwaki-gun, Japan Application February 21, 1955, Serial No. 489,509

4 Claims. (Cl. 18-54) The present invention relates to a process for the production of fibers or filament yarns of polyvinyl chloride or vinyl chloride copolymer.

The object of the present invention is to provide the fibers or filament yarns of the polyvinyl chloride or vinyl chloride copolymer easily and economically from the polyvinyl chloride, vinyl chloride or copolymer according to the melt spinning process.

Another object of the present invention is to provide the polyvinyl chloride filament yarns or fibers under control of the qualities of product in a mass production scale economically.

A further object of the present invention is to provide the polyvinyl chloride filament yarns or fibers effectively from the copolymer of vinyl chloride by using appropriate plasticizer and stabilizer.

Other objects, advantages as well as features of the present invention will be apparent from the following descriptions.

As is well known, it is difiicult to produce fibers or filament yarns which are suitable for textile fibers from polymers of vinyl chloride on an industrial scale. In consequence, the wet or dry spinning method, heretofore, has been the only method for this purpose. Even those spinning methods are disadvantageous from the economic point of view. Particularly, the melt spinning method, as it is called, has been considered as difiicult conceptionally due to the high viscosity and intrinsic molecular arrangement of the melt obtained and none have ever thought of its use for the spinning. Thus, the spinning of polyvinyl chloride fiber or fine yarn according to this method has never been considered as important. Under the circumstances, all studies are focussed on the copolymer of vinyl chloride exclusively, notwithstanding various troubles entailing in the raw material as well as the handling thereof and consequent high cost of operation.

The present invention has solved industrially this problem of the process for manufacturing the polyvinyl chloride filament yarn, which has hitherto been considered imposible, and rendered possible the production especially of polyvinyl chloride filament yarn in the melt spinning method extremely readily and economically on a large production scale, and further facilitated the adjustment of the qualities of product.

Specifically, according to the present invention, the required quantities of the plasticizer and stabilizer are added to polyvinyl chloride; the resulting mixture is heated to melt or fusion and the molten substance thus obtained is jetted or ejected through nozzles to form fine yarns or filament yarns, the spun filament yarns are kept at a lower temperature than about 100 C., preferably 40 to 100 C., so that the mutual adhesion of a number of filament yarns may be prevented and fixed so as not to destroy their shapes; thereafter those filament yarns are subjected to thecold or hot stretching or both operations and further 'to a heat treatment, and thus the efficient manufacture of polyvinyl chloride filament yarn achieved.

In the present invention, the high viscosity in molten state of vinyl chloride polymer is first decreased by admixing an equivalent quantity of the plasticizer therewith to facilitate the jet or ejection of filament yarns through nozzles, and a number of filament yarns or the multi-filament yarns thus spun are then introduced in a fixing tank held at a temperature between approx. 100 C. and a considerably lower temperature, said temperature being maintained in order to prevent the uniting or adhesion of a number of filament yarns having been ejected out of nozzles as well as to avoid the deformation thereof in fixing .the forms of filament yarn. In this case, when the fine yarn or fibers having been ejected out of nozzles are dipped in a water bath kept at a temperature from around 40 C. to the room temperature, the yarn will coagulate brittle, which renders a further stretching difiicult, thus prohibiting the practical usage. The fixing water bath is, therefore desirably held at a temperature of the order as above described. Thereupon, the yarns or' filament yarns thus fixed are consecutively subjected to either cold or hot stretching or to a combination of both types of stretching. It is well known that the stretching treatment is chosen appropriately in accordance with the degree of stretching required in the finished product. Further, to achieve the fixing of molecular arrangement sufiicient to avoid any further contraction of the denier of the finished product, the filament yarns which have undergone the vinyl chloride fine yarns or filament yarns by the in troduction of the aforementioned process which is capable of furnishing a marked improvement in the properties of spun filaments. Namely, as above described, a special process has been introduced wherein the fiber produced with addition of plasticizer and stabilizer is treated with an extracting agent to extract and remove a part or the Whole of the plasticizer mingled in the fibers. That is for the reason that admixing of plasticizer is needed from the point of melt spinning, but the inclusion in the product will lower the softening point and contraction temperature, thus resulting in the degradation of the qualities of product. plasticizer is removed from the product according to the present invention, the softening point and the contracting temperature will show an abrupt rise, leading to a re markable improvement in the qualities of product, which is extraordinarily advantageous in the practice. The preferable extracting'agents for the plasticizers are various as described hereinafter. Particularly, it has been ascertained that, when the vinyl chloride monomer is used for the treatment, the operation will be simple and very efiicient, because the vinyl chloride monomer has a boiling point at -13 C. and volatilizes at room temperature under normal pressure; but if the polyvinyl chloride filament yarn is treated with the vinyl chloride monomer having been liquefied at a lower temperature.

as lower than 20 C. or under pressure, the extracting capacity relative to the plasticizer or other waste oily constituents will become extremely high, accordingly the extraction purpose may be fulfilled simply and rapidly; and in addition as the vinyl chloride monomer vaporizes off at room temperature under normal pressure, the recovery thereof is also simple; further the qualities of. product will not be damaged as it can be treated-at I thereto, fixing the spun filament yarns at a temperature 2 Therefore, when the 3. below about 100 C. but above ordinary temperature and thereafter subjecting the aforesaid yarns to the stretching and heat treatment. Thus the present invention has various advantages in combination, such as an improvement in the qualities of product by. the extraction of plasticizcr from the filament yarns thus formed and further the simple and excellent result obtained by using an extracting agent such as vinyl chloride monomer in the extracting treatment.

Further, the vinyl chloride polymer used in the present inventionhas a polymerization degree of approximately 600 to 2,500, and it is possible to spin filament yarns from the polymer at the melting temperature of from 160 to 250 C. after adding the plasticizer and stabilizer thereto. The melting temperature is lowered with an increase of the quantity of plasticizer used. The plasticizers to be used are, for instance, D. E. P. (diethyl phthalate), D. B. P. (dibutyl phthalate), D. O. P. (dioctyl phthalate), T. P. P. (triphenyl phosphate), T. C. P. (tricresyl phosphate), B. P. B. G. (butyl phthalyl, butyl gly-colate) and the like, and the stabilizers to be used are, for instance, barium stearate, calcium salicylate, lead tribenzil-stearate, and the like. They may be used alone or in combination of several kinds thereof, and the quantity to be added of these plasticizers is normally approximately 10 to 60% based on the weight of the raw material, vinyl chloride polymer and that of the stabilizer is around 1 to As an extracting agent, for instance, carbon tetrachloride, trichlorethylene, trichlorethane, vinyl chloride monomer, and the like may be used. The extracting agents adapted to extract a part of the whole of the plasticizer and stabilizer may be used alone or in selected combinations of several thereof.

The treatment with the extracting agent is very simple and it is sufiicient to dip the filament yarns formed into the extracting agent for a short period of time. However, depending on the manner and extent of extraction, the extraction conditions such as temperature and time of treatment may be selected appropriately. Further, it is sufiicient to set the period of treatment directly after the spinning and formation and subsequently carry out the stretching and heat treatment, or to carry out the extraction treatment after a suitable after-treatment. Further, in regard to the fixing of spun fil ment yarns, hot stretching, the temperature of heat treatment and addition manner in the present invention, it is preferred to use ahot water bath, but the steaming, hot water pouring, gaseous heating or electrical heating and various other methods of heating may be chosen. Moreover, according to the present invention the color tone and the feel of filament yarns obtained may be improved by the addition of useful treating chemicals, such as penetrator, soft finishing agent, anti-electrostatic agent, delustering agent and the like, to the heating water, whereby the subsequent treating operation is facilitated.

According to the present invention, a fine filament yarn of the order of 1.5 denier can readily be obtained, and the yarn obtained is acid proof, alkali resistant, moisture resistant and has an appropriate softening property, and further may be efficiently utilized as clothing and the like and obtained in large quantities with low cost, having an extraordinarily wide application.

The properties of the product obtained according to the present invention are as shown in the following tabulation:

Denier Strength. Elongation,

Gr./D. Percent 1.500 1. 5-1. 8 20-50 30 x 30 strings 1. 8-2. 2 20-50 50 x 30 strings 2. 0-3. 0- -20 The present invention relates principally to the manufaeture of poly-vinyl chloride filamentyarn and likewiseto carry out the invention in regard to the copolymer containing vinyl chloride molecules.

For more easily understanding of the present invention, an embodiment of the apparatus for carrying out the process according to the present invention is shown by way of example in the accompanying drawings.

In the drawings, A designates a section for the melt spinning, B is a bath for fixing spun filament yarns, C is a section for the cold stretching, D is a section for the hot stretching. 1 is an inlet hopper in the section A of the melt spinning, 2 a feed screw conveyor of constant pressure, 3 a melting liner, 4 a screw for extrusion, 5 a nozzle plate provided with a number of nozzles, 6 a heating device provided outside of the lower bottom portion of the aforesaid melting liner 3, 7 nozzles for spinning, 8 a bottom end of extruding screw 4, 9 an angleshaped jut or protrusion, projecting upwardly from the nozzle plate 5 opposite said bottom end 8, 10 an inclined annular projection extending from the outer peripheral edge of the nozzles of nozzle plate 5, 11 filament yarn.

Example 1 As a plasticizer and a stabilizer, 30% D. E. P. and 5% barium stearate were mixed together with a vinyl chloride polymer of polymerization degree of 1000, and the resulting powdered specimen was charged into the inlet hopper 1 of the melt-spinning section A, and the powdered material was then fed in constant quantities into the melting liner 3 under constant pressure by means of the feed screw conveyer 2. The melting liner 3 is equipped with the extruding screw 4 and the nozzle plate 5 as well as the heating device 6. The powdered specimen fed as above described was melted by the heating device 6 at 230 C. and subsequently ejected from the nozzles 7 of nozzle plate 5 through the screw 4 and spun. The bottom end 8 is plane, opposite to which is positioned the angle-shaped jut 9, and the molten substance is fed smoothly along the inclined surfaces of the jut 9 and the inclined projection 10 without coming to a standstill in the bottom of depression and was made to run out from the nozzles provided in the nozzle plate 5.

The filament yarns 11 ejected out in a string form were immersed in a hot water bath 12 held at 70 C. and then fed to the cold stretching section C through the guide rollers 13.

The cold stretching section C is provided with stretching rollers 14, 15, 16 and 17. The yarns were passed from the upper end roller 14 and round the lower end roller 15 and further through the rollers 16, 17 and 16, during which course the yarns were stretched at ordisnary temperature (about 20 C.) to about twice the original length while being subjected to the cold drawing treatment and then were led to the heat treatment bath 18. Thereupon the yarns were further stretched to about twice the stretched length by the pull of the reeling roller 21, while passing through the guide rollers 19 and 20 in the warm water bath 18 at C. to the reeling roller 21 in the course of warm stretching treatment, and were further subjected to the heat treatment. The total stretching amounted to approximately 400%.

In the above-mentioned process, a product having a strength of about 3.0 and extension of about 10% at 5 denier by 30'filaments can easily be obtained.

Example 2 A mixture obtained by mixing parts polyvinyl ch10 a stabilizer (ordinarily 1 to 5 parts are chosen) was heated to 190 C. and subjected to the melt spinning, whereby the required filament yarns being spun by the process similar to that of Example 1, and subsequently these yarns were immersed in a solution of vinyl chloride monomer held at 20 C. for 20 minutes and then subjected to heat treatment at 100 C. Thus, the product was obtained.

Example 3 A mixture obtained by mixing 100 parts polyvinyl chloride with 15 parts D. O. P. and 15 parts methyl acetyl ricinoleate as plasticizers and 3 parts barium stearate as a stabilizer was heated to melt, and filament yarns were obtained in the same manner as Example 1. Said yarns were then dipped in ligroin, a solvent for D. O. P., for 30 minutes and heat-treated at 100 C.

The foregoing examples are given merely by way of illustration of the process according to the present invention, but never for limiting same. It should be understood that various modifications may be made without departing from the spirit and scope of this invention as set forth in the appended claims.

What I claim is:

1. A process for the production of filaments of a high molecular weight vinyl chloride polymer, which comprises the steps of melting a mixture of a high molecular weight vinyl chloride polymer and a plasticizer and a heat stabilizer by heating the same, spinning filaments from the resulting molten substance, and thereafter contacting said filaments with vinyl chloride monomer to remove at least a portion of said plasticizer and heat stabilizer from said filaments.

5 2. The invention of claim 1, said vinyl chloride monomer being in liquid form.

3. A process for the production of filaments of a high molecular weight vinyl chloride polymer, which comprises the steps of melting a mixture of a high molecular vinyl chloride polymer and a plasticizer by heating the same, spinning filaments from the resulting molten substance, and thereafter contacting said filaments with vinyl chloride monomer to remove at least a portion of said plasticizer from said filaments.

4. The invention of claim 3, said vinyl chloride monomer being in liquid form.

References Cited in the file of this patent UNITED STATES PATENTS OTHER REFERENCES Serial No. 362,460, Berg (A. P. 0), published April 27, 1943.

Claims (1)

1. A PROCESS FOR THE PRODUCTION OF FILAMENTS OF A HIGH MOLECULAR WEIGHT VINYL CHLORIDE POLYMER, WHICH COMPRISES THE STEPS OF MELTING A MIXTURE OF A HIGH MOLECULAR WEIGHT VINYL CHLORIDE POLYMER AND A PLASTICIZER AND A HEAT STABILIZER BY HEATING THE SAME, SPINNING FILAMENTS FROM THE RESULTING MOLTEN SUBSTANCE, AND THEREAFTER CONTACTING SAID FILAMENTS WITH VINYL CHLORIDE MONOMER TO REMOVE AT LEAST A PORTION OF SAID PLASTICIZER AND HEAT STABILIZER FROM SAID FILAMENTS.

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