Classifications

• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01D—MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
  • D01D5/00—Formation of filaments, threads, or the like
  • D01D5/06—Wet spinning methods
• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
  • D01F6/00—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof
  • D01F6/02—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from homopolymers obtained by reactions only involving carbon-to-carbon unsaturated bonds
  • D01F6/04—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from homopolymers obtained by reactions only involving carbon-to-carbon unsaturated bonds from polyolefins
• • D—TEXTILES; PAPER
  • D07—ROPES; CABLES OTHER THAN ELECTRIC
  • D07B—ROPES OR CABLES IN GENERAL
  • D07B1/00—Constructional features of ropes or cables
  • D07B1/02—Ropes built-up from fibrous or filamentary material, e.g. of vegetable origin, of animal origin, regenerated cellulose, plastics
  • D07B1/025—Ropes built-up from fibrous or filamentary material, e.g. of vegetable origin, of animal origin, regenerated cellulose, plastics comprising high modulus, or high tenacity, polymer filaments or fibres, e.g. liquid-crystal polymers
• • D—TEXTILES; PAPER
  • D07—ROPES; CABLES OTHER THAN ELECTRIC
  • D07B—ROPES OR CABLES IN GENERAL
  • D07B2201/00—Ropes or cables
  • D07B2201/20—Rope or cable components
  • D07B2201/2001—Wires or filaments
  • D07B2201/2009—Wires or filaments characterised by the materials used
• • D—TEXTILES; PAPER
  • D07—ROPES; CABLES OTHER THAN ELECTRIC
  • D07B—ROPES OR CABLES IN GENERAL
  • D07B2205/00—Rope or cable materials
  • D07B2205/20—Organic high polymers
  • D07B2205/201—Polyolefins
  • D07B2205/2014—High performance polyolefins, e.g. Dyneema or Spectra

Definitions

• the present invention relates to a polyethylene multifilament yarn which has a high tenacity and initial modulus, preferably a high knot strength and is substantially free from cohesion between single filaments.
• a multifilament yarn having cohesion between single filaments lacks flexibility and loses its strength to a great degree when being subjected to heat-treatment and is insufficient in adhesion ability with resin when being used for the composite material of yarn and resin, a polyethylene multifilament yarn obtained according to the above-mentioned methods is not suitalbe for a fiber material for industrial applications.
• a gel single filament especially in the non-crystallized part, is in such a state that the solvent is super-cooled, which may be supposed to be one cause for the formation of cohesion which takes place in collecting gel single filaments.
• the other possible cause is that since a multifilament to be subjected to drying step contains solvent between single filaments, the single filaments are dissolved in surface portion with the solvent which is heated during the drying step, and a cohesion between single filaments occurs owing to thus dissolved surface portion.
• a whole aromatic polyamide fiber has only 6 g/d of knot strength in spite of having a high level of tenacity, e.g. 22 g/d.
• a carbon fiber for example, having 29 g/d of tenacity
• a novel polyethylene multifilament yarn from a polyethylene having a weight average molecular weight of 700,000 or more which has a single filament denier of 3 d or less, a single filament tenacity of 40 g/d or more, ... and a single filament initial modulus of 1200 g/d or more, and does not have a structure showing a long period in the small angle X-ray scattering measurement, and has both a ⁇ -dispersion peak height of tan 6 of 0.017 or less in the measurement of dynamic modulus and a dynamic viscoelasticity E' value at 100 °C of 600 g/d or more, and is substantially free from cohesion between single filaments.
• the object of the present invention can be preferably attained by a specific polyethylene multifilament yarn having 15 g/d and more of knot strength in addition to the above-mentioned characteristics or that obtained by a gel-wet spinning method.
• Polyethylene used in the present invention may include a modified polyethylene obtained by copolymerizing ethylene and at least one other ' monomer, the latter being in not so large amount as impairing a technical effect of the present invention, e.g. 10 mole and less percents and, for example, being selected from the other alkene such as propylene, butylene, pentene, hexene, and 4-methylpentene, and vinyl monomer capable of being copolymerized with ethylene.
• a polyethylene multifilament yarn of the present invention may consist of a mixture of polyethylene with a small amount of the other polyalkene.
• Molecular weight of a polyethylene used in the present invention is necessary to be weight average molecular weight of 700,000 and more, preferably 2,000,000 and more, preferabley 3,000,000.
• a denier of a single filament of polyethylene multifilament yarn of the present invention is necessary to be 3 d or less, preferably 1.5 d or less, and more preferably 1 d or less.
• a single filament tenacity of multifilament is necessary to be 40 g/d or more, preferably 50 g/d or more, more preferably 60 g/d or more, and most preferably 70 g/d or more.
• An initial modulus of single filament of the present multifilament yarn is necessary to be 1,200 g/d or more, preferably 1,500 g/d or more, more preferably 1,800 g/d, and most preferably 2,000 g/d.
• a multifilament yarn of the present invention does not show a long period structure in the small angle X-ray scattering measurement.
• a fiber which shows a long period structure in this small angle X-ray scattering measurement has a big structure difference between crystalline region and amorphous region thereof, that is to say, such a fiber has such a structure that a molecular chain inside of fiber is not sufficiently extended.
• such a fiber neither has a single filament tenacity of 40 g/d or more nor a single filament initial modulus of 1,200 g/d or more.
• the multifilament yarn of the present invention is necessary to have a ⁇ -dispersion peak (peak approximately near -130 °C) height of tan6 in a dynamic viscoelasticity measurement of 0.017 or less, preferably 0.013 or less, more preferably 0.010 or less and to have a dynamic modulus E' value at 100 °C of 600 g/d or more, preferably 1,000 g/d or more.
• a height of y-dispersion peak of tan ⁇ in a dynamic viscoelasticity measurement represents an amount ratio of the amorphous region and that the higher is this height, the smaller is the amorphous region.
• the value of dynamic modulus E' falls down proportional to a measurement temperature and keeps high even at a high measurement temperature, if a degree of crystallinity and orientation of fiber is high, which means that the fiber has more perfect fibrous structure.
• the fiber of which height of ⁇ -dispersion peak of tan6 in a dynamic viscoelasticity measurement is higher than 0.013 and of which dynamic modulus of elasticity E' at 100 °C is less than 600 g/d has both a low degree of crystallinity of orientation and an insufficient fibrous structure. And such a fiber has neither a single filament tenacity of 40 g/d or more nor a single filament initial modulus of 1,200 g/d or more.
• the multifilament yarn of the present invention should be substantially free from cohesion between single filaments.
• substantially free from cohesion it is meant that a cohesion portion should be 2 or less per 10 meters of multifilament yarn. If the multifilament yarn is not free from cohesion between single filaments, the multifilament yarn comes to lack flexibility and to lose its tenacity when it is heated and to have a low adhesion force with resin, and consequently is not suited for use in industrial applications.
• the multifilament yarn of the invention preferably has a single filament knot strength of 15 g/d or more.
• a knotting action is needed, for example, applications for fishing line or rope, it is difficult to make the most of the tenacity of fiber if the fiber has a low knot strength.
• a novel polyethylene multifilament yarn of the present invention can be provided by a novel process described, for example, in the following.
• Polyethylene having a weight average molecular weight of 700,000 or more is dissolved into solvent to prepare 1 to 8 wt% solution of said polyethylene.
• This solution is extruded from the nozzle having a plurality of holes through the layer of air or inert gaseous atmosphere into a spinning bath consisting of coagulating agent or a spinning bath consisting of cooling agent in the upper layer and coagulating agent in the lower layer, to form a coagulated multifilament. And then the coagulated multifilament is introduced into an extracting bath consisting of extractant to extract solvent therefrom.
• a multifilament containing an extractant is dried separately from each other of single filament by vibrating it using a turbulent gas flow.
• a dry-wet spinning method that is, the method wherein a polymer solution is extruded through an air or inert gas atmosphere into a spinning bath consisting of an extractant
• a gel-wet spinning method that is, the method wherein a polymer solution is extruded through an air or inert gas atmosphere into a spinning bath consisting of a cooling agent in the upper layer and an etractant in the lower layer
• a solvent for polyethylene there is preferably used the solvent satisfying to have a good solubility with polyethylene, to be easy to be extracted with an extractant, and to have a boiling point higher than a dissolving temperature or spinning temperature.
• solvents there are preferably employed decaline, paraffin oil, tetraline and kerosene.
• a polyethylene concentration of the solution should be lower as the polyethylene used has a higher molecular weight.
• the concentration should be adjusted to provide a solution having a suitable viscosity in light of uniformity in dissolving, stability in extruding, spinnability, and stability in drawing.
• the polyethylene concentration should not be lower than one wt. % because not only a productivity of fiber comes down but also the resulting coagulated multifilament becomes so pliant that a running multifilament is unstable and is easy to undergo an unfabourable effect by the outside trubulence, and therefore a multifilament superior in uniformity cannot be obtained.
• a productivity of fiber is superior when a higher polyethylene concentration is employed, preferably it should not be higher than 8 wt. % because in such a concentration a viscosity of solution gets too high and an entanglement of polyethylene molecular chain in the polyethylene solution occurs too much, and because, in the concentration too high to be appropriate, not only the dissolving of polyethylene into a solvent cannot be carried out uniformly and the spinnability of polyethylene solution falls down, but also a multifilament obtained after removing out the solvent cannot be drawn at a sufficiently high draw ratio only to provide a multifilament having low physical properties.
• a dissolution temperature of polyethylene and a temperature of the polyethylene solution at the time of spinning are almost the same.
• the temperature is chosen appropriately from the range of approximately 120 °C to 250 °C. For instance, approximately 170 °C is suitable when a - solution of a polyethylene concentration of 3 % of a weight average molecular weight of 2,000,000 is spun.
• the polyethylene solution is extruded from the nozzle having a plurality of holes through the layer of air or inert gaseous atmosphere into a spinning bath consisting of coagulating agent or a spinning bath consisting of cooling agent in the upper layer and coagulating agent in the lower layer.
• the inert gas means in the present invention a gaseous material at a normal temperature which does not coagulate a fibrous solution of polyethylene extruded from the nozzle and does not react chemically with the fibrous solution.
• the distance of the layer of gaseous atmosphere is not restricted, but is appropriate to be 3 to 50 mm.
• a coagulated multifilament is prepared by coagulating the surfaces of single polyethylene filaments to be still in the fibrous solution state while said single polyethylene filaments separate each other in a spinning bath, there cannot occur a cohesion between single filaments even if they are collected in the same manner as in the usual spinning process. That is why a spinning bath consisting of a coagulating agent or consisting of a cooling agent in the upper layer and a coagulating agent in the lower layer is employed in the present invention.
• a spinning bath consisting of a coagulating agent
• a coagulating agent as neither dissolving nor swelling polyethylene at the coagulating temperature employed and as having a good compatibility with solvent, and as being volatile at a room temperature.
• acetones there can be used acetones, alcohols such as methanol and ethanol, methylene chloride, trichlorotrifluoroethane and an azeotrope of methylene chloride and trichlorotrifluoroethane.
• a cooling agent which has a specific gravity lower than that of a coagulating agent and has no compatibility with solvent is preferably. used. That is because the coagulated fiber becomes coarse in its surface and the drawn fiber obtained therefrom has only poor properties if the extruded fibrous solution is coagulated rapidly. Accordingly it is preferable to form a gel multifilament in advance before contacting the fibrous solution with a coagulating agent so as to prevent a rapid coagulation. For this reason there is preferably used such a cooling agent as having not a compatibility with solvent and as being capable of forming a gel multifilament in the cooling layer.
• cooling agent water is the best in light of safety and economy, but any liquid having the above-mentioned characteristics can be employed.
• a suitable depth and temperature of the cooling layer depends upon a spinning temperature and an amount of output of a spinning solution. It is preferable to adjust the cooling layer to have such depth and temperature that the extruded fibrous solution can be cooled below its gelation temperature there.
• the range of 3 cm to 30 cm is appropriate as a depth of the cooling layer and the range of 0 °C to 40 °C is appropriate as a temperature thereof.
• the gel multifilament formed in the cooling layer of the upper part is coagulated and a partial extraction of solvent therefrom is carried out both in the coagulating layer of the lower part.
• a coagulated multifilament is formed.
• single filaments run separately from each other and a coagulated multifilament is formed by coagulating the surfaces of single filaments while they are kept separate from each other, and therefore a cohesion between single filaments can be prevended.
• a depth of the cooling layer should be adjusted to be within a suitable range.
• a coagulating agent used for the coagulating layer in the lower layer is selected from the coagulating agents which have a specific gravity higher than that of the cooling agent and have a good compatibility with solvent, and are volatile at a room temperature.
• a coagulating agent methylene chloride, trichlorotrifluoroethane tetrachlorodifluoroethane, and azeotrope of methylene chloride and trichlorotrifluoroethane.
• any mixture of the above-mentioned compound or mixture with the solvent as a coagulating agent may be also used any mixture of the above-mentioned compound or mixture with the solvent as a coagulating agent.
• the suitable depth and temperature of the coagulating layer vary depending upon a spinning temperature, an amount of output of spinning solution and a coagulating ability of a coagulating agent, but the coagulating layer is preferable to have such depth and temperature that the surfaces of the single filaments can be substantially coagulated while the single filaments are running separately from each other.
• the range of from 0 °C to 40 °C is suitable as a temperature of the coagulating layer.
• the multifilament coagulated in the spinning bath is then introduced into a extracting bath and, there the residue solvent inside the coagulated multifilament is extracted.
• the residue solvent inside the coagulated multifilament is extracted with the first extractant, followed by the extraction with the second extractant.
• a multifilament obtained by extracting the residue solvent in the extracting bath is then sent to the drying step and there it is dried while being vibrated using a turbulent gas flow.
• the single filaments become to be separate from each other by catching the turbulent gas flow and are dried in its state, which can prevend the single filaments from making a cohesion.
• this turbulent gas there can be used any that does not react chemically with the extractant.and is in a gaseous state at a normal temperature. Usually air or nitrogen gas is employed.
• a pressure and flow rate of turbulent gas thus flowed are preferable to be sufficient to render the single filaments to be separate from each other.
• the multifilament heat-treated under a stretch condition is drawn at 125 °C to 155 °C in the ratio sufficient to provide a multifilament having a single filament tenacity of 40 g/d or more, and a single filament initial modulus of 1,200 g/d or more.
• This drawing is carried out in the two stages or more, preferably three stages or more .
• At the first half of drawing it may be carried out in a high draw velocity, but at the second half of drawing it is preferable to carry out drawing repeatedly in a relatively low draw velocity. And it is preferable to make a draw region as long as possible.
• the hot-plate having 2 meters or more long is preferably employed.
• the polyethylene multifilament yarn consists mainly of the extended molecular chain crystal, namely, crystal having a highly completed structure, and therefore it comes to have a single filament tenacity of 40 g/d or more and a single filament initial modulus of 1,200 g/d or more.
• the preferred polyethylene multifilament yarn of the present invention has a knot strength of 15 g/d or more though its relation with the structure is not clear.
• Such a fiber having not only a high tenacity and modulus but also a high knot strength can be said to be unique because in general it is difficult to satisfy the both properties at the same time.
• Tensile strength, initial modulus, dynamic modulus, and small angle X-ray scattering of the multifilament were measured in the following conditions.
• Atmosphere 20°C, relative humidity: 65 %
• Diameter of slit 0.3 mm ⁇
• a long period was sought using the equation of Bragg based upon the position of the interference spot (or line) on the meridian of small angle X-ray scattering picture. No appearance of the interference spot (or line) on the meridian was judged to mean that there was not recognized a structure showing a long period.
• Non-drawn or drawn multifilament yarn was observed by the naked eye along its length direction. And a multifilament having cohesion only at 2 or less parts per 10 m length was defined to be substantially free from cohesion between single filaments, and an existence of cohesion at the parts more than 2 was judged to mean that the multifilament is not substantially free form cohesion between single filaments.
• Linear polyethylene having a weight average molecular weight of 3x10 6 was dissolved Into decaline at 170 °C to prepare a solution having a polyethylene concentration of 3 wt%.
• This solution of 175 °C was extruded Into a spinning bath consisting of acetone containing 20 % decallne of 20 °C from a nozzle having 15 holes (hole diameter: 1) through the air layer which was 5 long from the nozzle, and thus was coagulated.
• the flow rate of the solution was 30 cc/minute.
• the coaoulated multifilament was collected and withdrawn at a speed of 7.5 m/minute.
• Linear polyethylene having a weight average molecular weight of 3x10 6 was dissolved Into decaline at 170 'C to prepare a solution having a polyethylene concentration of 3 wt%.
• This solution of 175°C was extruded into water from the nozzle having 15 holes (diameter of the hole: 1 ) through the air layer of 20 °C which was 5 mm long from the nozzle and thus was gelatinized by cooling it to prepare a gel multifilament.
• the flow rate of the solution from the nozzle was 30 cc/minute.
• gel multifilament was collected and withdrawn at a speed of 7. 5 m/minute.
• Said gel multifilament was then introduced into the extracting bath consisting of acetone of 20 °C to extract decaline remaining therein. and then was dried in such a state that the single filaments were collected. and was wound up.
• This multifilament was drawn at the two stages in the following condition.
• Thus obtained drawn multifilament had a tenacity of 46 g/d and an initial modulus of 1320 g/d.
• the drawn multifilament had a ⁇ -dispersion peak of tan ⁇ of 0.019 and an E- value at 100 °C of 880 9/d.
• the obtained multifilament yarn had a lot of cohesions between single filaments and was difficult to open neatly.
• the gel multifilament taken out from the spinning bath which was obtained accordino to the spinning method mentioned above was dried at 60 °C. but the resulting mulifilament had a lot of cohesions between single filaments and could not be opened at all.
• Linear polyethylene havino a weight average molecular weight of 2.2x10 6 was dissolved Into decaline of 170°C to prepare a solution having a polyethylene concentration of 3.5 wt.%. This solution was spun. extracted, dried, and heat-treated keeping a constant lenoth in the same manner as In the examples 1 to 4. The resulting multifilament was drawn under the condition described in the following Table 3.
• the drawn multifilament had a sinole filament denier 1.1 d, a tenacity of 63 g/d. and an initial modulus of 2040 g/d. And the drawn multifilament did not show a lono period structure in the small angle X ray scattering. had a ⁇ -dispersion peak of tan ⁇ of 0.009. and had a E value at 100 °C of 1720 9/d. This drawn multifilament yarn was free from cohesion between single filaments and was superior in opening.
• the same solution as that of the example 1 was extruded into the air layer from the nozzle having 30 holes (hole diameter: 0.5). and was passed by 5 there, and thereafter was cooled, gelatinized, and coagulated In the spinning bath consisting of water In the upper layer and trichlorotrifluoroethane In the lower layer.
• the flow rate of the solution from the nozzle was 30cc/minute.
• the coagulated multifilament was collected and wound up at a speed of 7.5m/minute.
• the depth of water layer was 70 and that of trichlorofluoroethane layer was 250.
• the coagulated multifilament was then Introduced into the extractino bath consisting of trichlorotrifluoroethane of 10 °C to extract decaline remaining therein. and, thereafter, was dried and heat-treated keeping a constant length. After this heat-treatment, the multifilament was continuously drawn In one stage at 130 'C and was wound up.
• This drawn multifilament was further drawn in the same manner as In the example 5.
• Thus obtained multifilament had a single filament denier of 0. 71 d .
• This multifilament had a ⁇ -dispersion peak of tan ⁇ of 0.01 0 and an E' value at 100 °C of 1250 g/d. and was free from cohesion between single filaments.
• Linear polyethylene having a weight average molecular weight of 4 x 10 6 was dissolved into kerosene at 180 °C to prepare a solution having a polyethylene concentration of 5.0 wt %.
• This solution was extruded into the air layer from the nozzle having 10 holes (hole diameter: 1 mm), and was passed by 10 mm there, and thereafter was cooled, gelatinized, and coagulated in the spinning bath consisting of water in the upper layer and trichlorotrifluoroethane having 30 % kerosene in the lower layer, and then was collected to obtain a coagulated multifilament.
• the temperature of the spinning bath was 9 °C.
• the depth of the upper layer was 100 mm and that of the lower layer (trichlorotrifluoroethane) was 200 mm.
• the flow rate of the solution from the nozzle was 30 cc/minute and the coagulated multifilament was would up at a speed of 15 m/minute.
• the coagulated multifilament was introduced into the extracting bath consisting of trichlorotrifluoroethane of 5 °C to extract kerosene remaining in the multifilament, and thereafter, was dried and heat-treated keeping a constant length in the same manner as in the example 1. After this heat-treatment, the multifilament was drawn in one stage at a draw ratio of 8 at 130 °C and would up.
• This drawn multifilament was further drawn continuously in two stages at a feed speed of 1 m/minute. (second stage of drawing: temperature 143 °C, draw ratio 3.5, third stage of drawing: temperature 145 °C, draw ratio 1.4).
• second stage of drawing temperature 143 °C, draw ratio 3.5
• third stage of drawing temperature 145 °C, draw ratio 1.4
• drawn multifilament had a single filament denier of 1.5 d, a single filament tenacity of 56 g/d, and an initial modulus of 1600 g/d. And there was not recognized a long period structure in the small angle X-ray scattering regarding this multifilament.
• This multifilament had a Y-dispersion peak of tan 6 of 0.011, and had an E' value at 100 °C of 1300 g/d. And this multifilament was free from cohesion between single filaments.
• the drawn multifilament by the one stage drawing method in the same manner as in the example 9 was drawn by 2.5 times at a feed speed of 1 m/minute at 140 ° C, (total draw ratio: 20).
• the polyethylene multifilament yarn of the present invention has an extremely high tenacity and initial modulus, and is substantially free from cohesion between single filaments. Therefore, the polyethylene multifilament yarn of the present invention is flexible and does not undergo a decrease of strength retention when it is heated. Accordingly, it is extremely suited to use for industrial applicaitons.

Landscapes

• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Mechanical Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Artificial Filaments (AREA)

Applications Claiming Priority (2)

Publications (3)

Family

ID=12186653

Family Applications (1)

Country Status (3)

Cited By (71)

Families Citing this family (1)

Citations (1)

Family Cites Families (3)

• 1986
  • 1986-02-06 WO PCT/JP1986/000049 patent/WO1986004936A1/ja active IP Right Grant
  • 1986-02-06 EP EP86901136A patent/EP0213208B1/de not_active Expired - Lifetime
  • 1986-02-06 DE DE8686901136T patent/DE3682241D1/de not_active Expired - Fee Related

Patent Citations (1)

Non-Patent Citations (2)

Also Published As

Similar Documents

Legal Events