JP3224561B2 - Flash spinning of fiber-forming polymers - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

FIELD OF THE INVENTION This invention relates to the flash spinning of plexifilamentary film-fibril strands consisting of polymers which can be plasticized substantially in carbon dioxide or water and have a melting point below 300 ° C. About the law.

[0002] In summary, the present invention relates to a method for producing plexifilamentary film-fibril yarns by flash spinning from a mixture of carbon dioxide, water and the above polymers.

[0003]

BACKGROUND OF THE INVENTION Blades and White are disclosed in U.S. Pat.
No. 1,519 describes plexifilamentary film-fibril yarn flash spinning from a fiber-forming polymer. A solution prepared by dissolving a polymer in a liquid in which the polymer does not dissolve at or below the normal boiling point is subjected to a medium at a temperature lower than the normal boiling point of the liquid and at a spontaneous pressure or higher at a low temperature and substantially lower pressure. Extrude inside. This flash spinning causes the liquid to evaporate, thereby cooling the extrudate and forming a plexifilamentary film-fibril yarn of the same polymer.

According to Blades and White, the following liquids: aromatic hydrocarbons, such as benzene, toluene, etc .; aliphatic hydrocarbons, such as butane, pentane, hexane, heptane, octane, and isomers and homologs thereof Alicyclic hydrocarbons such as cyclohexane; unsaturated hydrocarbons; halogenated hydrocarbons such as methylene chloride, carbon tetrachloride, ethyl chloride, methyl chloride; alcohols; esters; ketones; nitriles; amides; Class; sulfur dioxide; carbon disulfide; nitromethane;
Water; and mixtures of the above liquids are useful for flash spinning. The patent further states that the flash spinning solution can include dissolved gases such as nitrogen, carbon dioxide, helium, hydrogen, methane, propane, butane, ethylene, propylene, butene, and the like. Less soluble gases, ie, gases having a solubility in the polymer solution of 7% or less under spinning conditions, are preferred because they improve plexifilamentary film-fibrillation.

[0005] Blades and White state that the polymers that can be flash spun include synthetic fiber-forming polymers or polymer mixtures that can have significant crystallinity and high crystallization rates. It is stated that a preferred class of polymers is mainly crystalline and free of polar groups, such as crystalline polyhydrocarbons, for example polyethylene or polypropylene.

[0006] US Pat. No. 3,169,899 discloses other polymers which can be flash spun, such as polyesters,
Polyoxymethylene, polyacrylonitrile, polyamide, polyvinyl chloride and the like are mentioned. The patent further mentions other polymers that are flash spun as a mixture with polyethylene, such as ethylene-vinyl alcohol, polyvinyl chloride, polyurethane, and the like.
Example 18 of U.S. Pat. No. 3,169,899 describes flash spinning from a methylene chloride solution of a mixture of polyethylene and ethylene-vinyl alcohol copolymer in which polyethylene is the major component.

[0007] Flash spun polyethylene products are commercially available in significant quantities and are well utilized. Tyvek ^R is polyethylene spunbonded sheet products commercially available from DuPont (EI duPont de Nemours and Company) . This sheet product is used in the construction and packaging industry. Tyvek ^R also flash-spun product is used in protective clothing since it has excellent barrier properties for a particular penetration. However, because of the hydrophobic nature of polyethylene, the garments made therefrom are necessarily uncomfortable in hot and humid weather. There is a clear need for more hydrophilic flash-spun products in garments and other end uses. Furthermore, flash spinning of polyolefins can preferably be carried out from environmentally safe, non-toxic solvents.

[0008] Trichlorofluoromethane (Freon-11)
Was a very useful solvent in the industrial production of polyethylene plexifilamentary film-fibril yarn. However, the dissipation of such halocarbons into the atmosphere is a serious cause of global ozone depletion. A general debate on the issue of ozone depletion can be found, for example, by PS Zurer, "Research on halocarbon alternatives that reduce ozone is being enhanced (SearchIntensifies for Alternatives).
to Ozone-Depleting Halocarbons)
cal & Enginnering News [17-20, February 8, 1
988]. The replacement of trichlorofluoromethane used in industrial flash spinning processes with environmentally safe solvents must be done to minimize the ozone depletion problem.

[0009] It has now been discovered, according to the present invention, that flash-spun products desirable for use in the garment, construction and packaging fields are obtained by flash-spinning from an environmentally acceptable mixture of carbon dioxide and water. Was done.

[0010]

SUMMARY OF THE INVENTION In accordance with the present invention, a spinning mixture comprising water, carbon dioxide and a polymer substantially plasticizable in carbon dioxide or water and having a melting point of 300 ° C. or less is obtained.
A plexifilamentary film of the polymer formed at a temperature of 0 ° C. and a pressure higher than the spontaneous pressure of the mixture, and then flash-spinning the resulting mixture into a substantially lower-temperature, lower-pressure region. -A method for flash spinning fibril yarns is provided. The present invention also provides a plexifilamentary film-fibril yarn produced by the method of the present invention. However,
The polymer is a mixture of polyurethane and polyolefin
Or ethylene-vinyl alcohol copolymer
Graph of acrylic acid on body (EVOH) and polyolefin
It is a mixture with the copolymer that has been cured. Substantially plasticizable means that the polymer is softened to a low viscosity by absorbing carbon dioxide or water.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As used herein, the term plexifilamentary film-fibril is defined as a plurality of thin, ribbon-like, random, variable length, average thicknesses of less than 4 microns. A yarn is characterized in that certain film-fibril elements have a three-dimensionally integrated network, generally extending together along the longitudinal axis of the yarn. . The fibril elements join together at irregular intervals throughout the length, width and thickness of the yarn and again separate to form a three-dimensional three-dimensional network. Such yarns are disclosed by Blaides and White in U.S. Pat. No. 3,081,
No. 519 and Anderson and Romano, U.S. Pat.
No. 27,794 is described in further detail.

Particularly useful polymers in the practice of this invention are those described in Examples 24 and 25, ie,
Mixtures of urethane and polyethylene and ethylene-bi
Acrylic acid in benzyl alcohol copolymer and polypropylene
Is a mixture with a copolymer on which is grafted . Copolymers of ethylene and vinyl alcohol have a copolymerized ethylene content of at least about 20 mole percent, and the vinyl alcohol content is generally at least about 50 mole percent. Ethylene-vinyl alcohol copolymer is optionally copolymerized with olefins such as propylene, butene-
1, pentene-1 or 4-methylpentene-1 may be contained in an amount that does not change the intrinsic properties of the copolymer, generally not more than about 5 mol% based on the total amount of the copolymer. These ethylene-vinyl alcohol polymers generally have a melting point of about 160-190 ° C. The ethylene-vinyl alcohol polymer is usually produced by copolymerizing ethylene and vinyl acetate, and then saponifying an acetate group of the copolymer. The polymer must be well-mixed and at least about 90% of the acetate groups should be saponified. This method is known in the art. Particularly advantageous ethylene-vinyl alcohol polymers can be made by grafting a long chain of polyethylene or polypropylene onto a random ethylene-vinyl alcohol copolymer, as illustrated in Examples 21, 22 and 23. . The grafting operation may be performed according to a conventional method. For example, an ethylene-vinyl alcohol copolymer and a pendant anhydride-containing polyolefin are melted under shearing in a batch or continuous mixing vessel (eg, an extruder). This is accomplished by mixing. The grafted polymer appears to be compatible when used in combination with polyolefin. Polyolefin graft rates of 5 to 50% by weight (e.g. 10% by weight in Examples 21 and 22 and 20% by weight in Example 23) are most advantageous.

The method requires forming a spinning mixture consisting of the polymer, water and carbon dioxide. Water is present in the range of 5 to 50% based on the total weight of the spinning mixture. Carbon dioxide is present in the range of 30 to 90% based on the total weight of the spinning mixture. The polymer is present in the range from 1.5 to 25% based on the total weight of the spinning mixture.

As mentioned above, the spinning mixture can also comprise an ethylene-vinyl alcohol copolymer and furthermore a polyolefin in the range of 0 to 25% based on the total weight of the spinning mixture. Polyethylene and polypropylene are preferred as additional polyolefins.

[0015] The spinning mixture can optionally include a surfactant. The presence of such a surfactant aids in the emulsification of the polymer or in the formation of the mixture. Examples of suitable nonionic surfactants are described in U.S. Pat. No. 4,082,887.
And its content is indicated in the same reference. Among the commercially available nonionic surfactants that are suitable, "Spans", which is a mixture of esters of the monolaurate, monooleate, and monostearate types, and "Tweens", which is one of these esters And polyoxyethylene derivatives. "Spans" and "Tweens" are products of ICI America (Wilmington, DE).

The temperatures required to produce the spinning mixture and to flash spin the mixture are usually about the same, usually in the range of 130 to 275 ° C. The mixing and flash spinning are performed under a pressure higher than the spontaneous pressure of the mixture. The pressure during the production of the spinning mixture is generally 1,2
It ranges from 00 to 6,000 psi.

Conventional additives for flash spinning can be added to the spinning mixture by known techniques. These additives can function as UV stabilizers, antioxidants, fillers, dyes, surfactants, and others.

[0018]

EXAMPLES Two devices An autoclave was used in the following examples below.
These examples do not limit the present invention at all. The first autoclave, called 300 cc autoclave [Autoclave Engineers (Erie PA)] has a turbine blade stirrer, a temperature and pressure measuring device, a heating device, a carbon dioxide pressurized introduction pump and an inlet for introducing components. Equipped. There is an outlet at the bottom of the autoclave, and a conduit from it has a diameter of 0.
It is connected to a 079 cmm spinning nozzle. The spinning nozzle has a length / diameter ratio of 1 and the inlet narrows toward the tip just as an inverted cone with a vertical angle of 120 °. The second autoclave is called a 1 gallon autoclave (also made by Autoclave Engineers) and has a capacity of 300cc.
It has the same equipment as an autoclave.

Test Procedure The surface area of the plexifilamentary film-fibril yarn is a measure of the degree of fibrillation and fineness of the flash spun product. Surface area is S. Brunauer, PH Emm
ett and E. Teller in the Journal of American Chemical So
ciety 60 , 309-319 (1938), measured by the so-called BET nitrogen absorption method, and reported in m ² .

The tensile strength and elongation of the flash spun yarn were measured with an Instron tensile tester. The yarn has a temperature of 70
゜ F, adjusted to a relative humidity of 65%, and tested under the same conditions.

The denier of the yarn was measured from a weight of the yarn of 15 cm. The sample was then twisted at 10 twists per inch and loaded into the thread mount of the Instron tester. The gauge length was 1 inch and the extension rate was 60% for 1 minute. Tensile strength at break in grams per denier (gpd)
Recorded.

In the following examples, all parts and percentages are by weight unless otherwise indicated. The conditions for all examples are summarized in Table 1.

Example 1 (Reference Example) In a 300 cc autoclave, 7 g of ethylene-vinyl alcohol copolymer, 43 g of crushed ice, and 50 g
Crushed dry ice was continuously introduced. The copolymer is 3
It contains 0 mol% of ethylene units and has a melt flow rate of 3 measured by a standard method at a temperature of 210 ° C. and a pressure of 2.16 kg
g / 10 min, melting point 183 ° C., and density 1.2 g / c
c. The resin is available from EI duPont under the trade name SELAR ^R
Commercially available as 3003.

The autoclave was closed and the vessel was pressurized to 850 psi (5861 kPa) with liquid carbon dioxide for 5 minutes and stirred until the mixture was at room temperature (24 ° C.). The amount of carbon dioxide added was determined by the density (polymer (1.2 g / cc),
Water (1.0 g / cc) and liquid carbon dioxide (0.72 g / cc) at 24 ° C. were calculated from the volume difference, assuming that the autoclave was completely filled. At the same time, the amount of carbon dioxide added was 166 g. The stirrer is 2,0
Rotating at 00 rpm, heating was started. When the temperature of the autoclave contents reached 175 ° C, about 10% carbon dioxide and 10% water were vented to adjust the internal pressure and the pressure was reduced to 2500 psi (17,238 kPa). After degassing, the spinning mixture, as shown in Table 1,
3.6% ethylene-vinyl alcohol copolymer, 1
It contained 9.8% water and 76.6% carbon dioxide.
Stirring was continued at a temperature of 175 ° C. and a pressure of 2500 psi for 30 minutes. The stirring was stopped, and the outlet valve was immediately opened, and the mixture was discharged from the spinning nozzle which was also heated to 175 ° C. The mixture was flash spun and collected.

A scanning electron microscope (SEM) showed a finely fibrillated continuous plexifilament yarn. The yarn was remarkable in elasticity and excellent in recovery.

Example 2 (Reference Example) The operation of Example 1 was carried out in the same manner. However, an ethylene-vinyl alcohol copolymer having an ethylene unit of 44 mol% was used. This 44 mol% copolymer is EI duP
Obtained under the trade name SELAR ^R 4416 from ont. The copolymer has a melt flow rate of 16 g / 10 min (210 ° C., 2.
16kg), melting point 168 ° C, and density 1.15g
/ Cc. As a result of observation with a scanning electron microscope, a finely fibrillated plexifilamentary yarn was obtained. The yarn had excellent elasticity and exhibited the same appearance as the yarn of Example 1.

Example 3 (Reference Example) Example 2 was carried out only with the spinning pressure set at 2,550 psi. As a result, a highly elastic plexifilamentary yarn was obtained. As a result of SEM analysis, the obtained yarn was coarser than the yarn of Example 2.

Example 4 (Reference Example) The procedure of Example 1 was repeated except that the polymer concentration was increased and the spinning pressure was 3,300 psi. A yarn similar to that of Example 3 was obtained.

Example 5 (Reference Example) Example 1 was carried out except that the spinning pressure was 3,500 psi and 0.5% based on the total weight of the spinning mixture, of high density polyethylene (HDPE) was added. The polyethylene used had a melting index of about 0.8 and was manufactured by Cain Chemical (Sabine,
Which is commercially available under the trade name of ALATHON ^R 7026A from TX). As a result, a high-quality finely fibrillated plexifilamentary yarn was obtained. This yarn was elastic but lower than the yarn of Example 1.

Example 6 (Reference Example) Example 5 was carried out only by increasing the amount of polyethylene. When measured with a scanning electron microscope, the fibrillation was slightly coarser than that of the yarn of Example 5, and a fine fibrillated continuous yarn was obtained. This yarn lost further elasticity and was lower than the yarn of Example 5.

Example 7 (Reference Example) Example 5 was carried out by further increasing the amount of polyethylene.
SEM analysis showed that the obtained yarn was a coarse plexifilamentary yarn. The yarn was not elastic.

Example 8 (Reference Example) The procedure of Example 1 was carried out with various components as shown in Table 1. In this example, 65% of the spinning mixture was added.
2 g of a nonionic surfactant mixture containing "Span" 80 and 35% "Tween" 80 were added. In this example, the autoclave was not depressurized and was heated to 177 ° C.
While maintaining the pressure, the pressure reached there was taken as the spinning pressure. As a result, a mat-shaped plexifilamentary continuous yarn having somewhat coarse fibrillation was obtained. The fibers were elastic.

Example 9 (Reference Example) Example 8 was carried out with various components as shown in Table 1. The obtained yarn was the same as that obtained in Example 8.

Example 10 (Reference Example) Example 1 was carried out with various components as shown in Table 1. As a result, a very fine, plexifilamentary white continuous yarn was obtained.

Example 11 (Reference Example) Example 5 was carried out using a linear low-density polyethylene instead of a high-density polyethylene as shown in Table 1.
Linear low density polyethylene (melt index: 25) is Dow Ch
Aspun ^R 6801 from emical Corp. (Midland, MI)
It is commercially available under the trade name. As a result, a fine, plexifilamentary discontinuous yarn having a length of 1/4 to 1/2 inch was obtained.

Example 12 (Reference Example) In a 1-gallon autoclave, 600 g of ASPUN ^R 680 was added.
The vessel was sealed with 1 and 700 g of water. The autoclave discharge manifold is 0.035 inch in diameter and 1 apex.
It was attached to a spinning nozzle having a 20 ° inverted conically tapered inlet. The vessel was maintained at 20 inches of mercury for 15 seconds using a vacuum pump to remove most of the air. However, much of the water was not removed. Then, the container was pressurized with carbon dioxide gas and filled with 1,500 g of carbon dioxide gas. The amount of carbon dioxide was measured with a "Micro-motion" mass flow meter. Stirring was started and the number of revolutions was maintained at 1,000 rpm. Heating of the vessel was started and continued until the target temperature of 170 ° C. was reached. The pressure was adjusted by venting a small amount of steam and finally stabilized at 4,500 psi. The resulting mixture is maintained at 170 ° C. for 1 minute and the stirring speed is
The speed was reduced to 50 rpm, the outlet valve was immediately opened, and the mixture was discharged to a spinning nozzle heated to 210 ° C. As a result, a fine fibrillated continuous yarn was formed.

[0037] Example 13 (Reference Example) ASPUN ^R of 300g Example 12, only the autoclave
6801, 125 g of Selar ^R OH 4416 ethylene-vinyl alcohol copolymer (manufactured by duPont, melting index: 1)
6), charged with 840 g of water and introduced with 1,700 g of carbon dioxide. Spinning resulted in a finely fibrillated continuous yarn much like Example 1, but with higher hydrophilicity and better elastic recovery.

Example 14 (Reference Example) Using a 300 cc autoclave, the same operation as in the 1 gallon autoclave was performed. Autoclave 30g of Alathon ^R 7050 high density linear polyethylene through the introduction hole was introduced (melt index 17.5) (manufactured by Cain Chemical Co.) and 56g of water. The autoclave was evacuated briefly to 20 inches of mercury to remove most of the air from the autoclave. The autoclave was pressurized by the addition of 146 g of carbon dioxide gas, the stirrer was spun at 2,000 rpm, and heating was started and the temperature was raised to the target 170 ° C. Once the temperature had risen to the target, a small amount of the mixture was vented and the pressure was adjusted to 4,500 psi. The resulting mixture was stirred for another 15 minutes. The outlet valve was opened and the resulting mixture was spun through a spinning nozzle. The result was a pulp of fine fibrillated, high quality fibers 1/16 to 2 inches in length. The obtained fiber is useful for producing a sheet structure by a known papermaking method.

[0039] Example 15 (Reference Example) Selar ^R of 15g Example 14, just to the autoclave
OH 4416 resin, it was repeated by filling 15 g ASPUN ^R 6801 resin, and water 56 g. Autoclave is 1
Pressurized with 46 g of carbon dioxide gas. Spinning pressure is 4,700p
was si. A very fine fibrillated continuous yarn is obtained. The yarn is soft and the fibers can be easily separated from the yarn bundle.

[0040] Example 16 (Reference Example) Selar ^R of 15g Example 14, just to the autoclave
OH 4416 resin, filled ASPUN ^R 6801 resin, and water 56g of 30g, spun at 3,700psi with carbon dioxide gas
And carried out under pressure. As a result, a fine fibrillated continuous plexifilamentary yarn was obtained.

Example 17 (Reference Example) Example 12 was prepared by merely adding 100 g of Selar to an autoclave.
^R OH 4416 resin, 500 g ASPUN ^R 6801 resin,
The operation was performed by charging 700 g of water and 1,300 g of carbon dioxide gas. The autoclave is heated to 170 ° C,
Pressurized to a target pressure of 500 psi. The stirrer was replaced with multiple high shear paddle / turbine airfoils. A fine fibrillated continuous yarn of high quality was obtained. When the yarn was twisted and subjected to a tensile test, the tensile strength at break was 1.45.
g / denier, elongation at break: 38%.

Example 18 (Reference Example) Example 17 was repeated with the spinning temperature raised to 180 ° C.
The obtained yarn is substantially equivalent to that of Example 17 and has an elongation of 38.
The tensile strength at 7% was 1.72 g / denier. The surface area was measured by a nitrogen absorption method and found to be 4.44 m ² / g.

Example 19 (Reference Example) Example 1 was prepared using only 4 g of Huntsman 7521 polypropylene (Huntsman Polypropylene, Woodbury, NJ), a melt flow rate of 3.5 g / 10 min, and a melting point of 168 ° C. for injection molding. Homopolymer, 6g of Selar ^R OH 4
416 ethylene-vinyl alcohol copolymer, 43g
Of ice and 50 g of crushed dry ice. The autoclave was heated to the target temperature of 175 ° C., the pressure increased to 3,500 psi, and stirred at 2,000 rpm for 15 minutes. The discharge valve was opened and discontinuous, coarsely fibrillated fibers were obtained in clumps.

Example 20 (Reference) Example 19 was prepared using only 10 g of Selar ^R OH 4416 resin, 4 g of Huntsman 7521 polypropylene resin,
The operation was carried out by introducing 3 g of ice and 50 g of crushed dry ice. A finely fibrillated, semi-continuous, massive fiber was obtained.

Example 21 (Reference Example) Example 12 was prepared by merely adding 300 g of Alanth to an autoclave.
on ^R 7050, 100 g of "E64179-124-1" (ethylene-vinyl alcohol copolymer grafted with about 10% by weight of high-density polyethylene), 1200 g of carbon dioxide and 5 g
The operation was carried out by introducing 00 g of distilled water. Nozzles with slit-like spin holes were used to produce a web in a flat shape rather than a cylindrical shape. Final temperature was 175 ° C. Other operations were the same as in Example 12.
As a result, the twisted tenacity was 4 g / denier, the elongation was 46%, and the surface area measured by the BET method was 1
A finely fibrillated continuous yarn of 3 m ² / g was formed.

"E64179-124-1" is not a commercial product.
The material uses SELAR ^R OH 4416 and is manufactured at the point of use by grafting it with a modified high density polyethylene resin itself. The high-density polyethylene used was modified in a twin-screw extruder by adjusting the amounts of peroxide initiator and maleic anhydride. The modified resin is called "HDPE-G-MAN" (maleic acid grafted high density polyethylene). SELAR ^R O
H 4416 at 220 ° C. in a twin screw extruder,
About 10% by weight of "HDPE-G-MAN" was grafted and modified at the point of use. A graft site is formed by the anhydride / hydroxyl reaction, which chemically binds HDPE and EVOH.

Example 22 (Reference Example) The operation was carried out in the same manner as in Example 21 except that only 380 g of A
"of lanthon ^R / 7050 and 20g E64179-124-
1 "was used. The results were substantially the same as in Example 21 except that the resulting yarn had a significantly reduced hydrophilicity and hand, rather than possessed by pure polyethylene yarn. It appeared to be composed of yarns exhibiting binding characteristics.

Example 23 (Reference Example) Example 22 was prepared by merely adding 300 g of Sh in an autoclave.
ell's PP WRS5-675 (Shell Chemicals, Short Hills, New Jersey, USA)
Polypropylene polymer) and 100
g of "E64179-124-5" (an ethylene-vinyl alcohol copolymer similar to that described in Example 21 with only about 20% by weight of polypropylene grafted) and 1555 g of carbonic acid The test was performed with gas filling. A 20 inch wide continuous sheet product was obtained which was fine but slightly coarser and fibrillated than when polyethylene was the polymer.

[0049] Example 24 (Embodiment) The embodiment 22 of 300g just "HTX-6133" (melt spinnable polyurethane polymer (a type of butylene / poly (alkylene ether) phthalate)), Alathon of 120 g ^R / 7050 high density polyethylene and 1
The autoclave was filled with 715 g of carbon dioxide gas. A very fine fibrillated yarn with a unique "silk" feel and elasticity was obtained.

HTX-6133 is a very soft HYT
REL ^R resin, consisting of 77% by weight soft segments (soft parts) and 23% by weight heart segments (hard parts). The material is particularly useful in U.S. Pat.
Patent) No. 4,731,407 (Benim)
Other Examples) (Preparation of Elastomer A), the entire contents of which are incorporated herein by reference.

[0051] Example 25 (present invention) Example 14, of 15.5g Just autoclave, ethylene melt index 16 -. A vinyl alcohol copolymer, Selar ^R 4416 (E.I du Pont
de Nemours and Company (commercially available from Wilmington, Del., USA), 15.5 g of Polybond ^R 101
1. A copolymer obtained by grafting acrylic acid onto polypropylene having a melting index of 20 (British Petrole)
um Chemical Company (commercially available from Hackettstown, New Jersey, USA), 4
The operation was performed by charging 9 g of distilled water and 120 g of carbon dioxide gas. The resulting mixture is brought to a temperature of 200 ° C. and 5000 ps
Stirred under pressure i for 15 minutes and then spun through a 0.0031 inch spinneret. A well-fibrillated plexifilamen-like continuous yarn was obtained.

[0052]

[Table 1]

Continued on the front page (72) Inventor Carl Kenneth McMillin 23236 Ritz, Virginia, U.S.A. Chimney Dallington Circle 104 (72) Inventor Jillon Qiu Chien, 19707, Delaware, U.S.A. JP-A-3-206111 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) D01F 6/04 D01F 6/46 D01D 5/11

Claims (1)

(57) [Claims] 1. A process for flash-spinning a plexifilamentary film-fibril yarn of a polymer which can be substantially plasticized in carbon dioxide or water and has a melting point of 300 ° C. or less: (a) water, carbon dioxide And forming a spinning mixture comprising the polymer at a temperature of at least 130 ° C. and a pressure greater than the spontaneous pressure of the mixture, and (b) flashing the resulting mixture into a substantially lower temperature and lower pressure region. Spinning, wherein the polymer is polyurethane and polyolefin.
A mixture with ethylene or ethylene-vinyl alcohol
Acrylic acid grafted to polyester copolymer and polyolefin
A flash spinning method, wherein the flash spinning method is a mixture with a copolymer .