CA1325143C - Rope for traction - Google Patents
Rope for tractionInfo
- Publication number
- CA1325143C CA1325143C CA000576525A CA576525A CA1325143C CA 1325143 C CA1325143 C CA 1325143C CA 000576525 A CA000576525 A CA 000576525A CA 576525 A CA576525 A CA 576525A CA 1325143 C CA1325143 C CA 1325143C
- Authority
- CA
- Canada
- Prior art keywords
- copolymer
- rope
- molecular weight
- filaments
- traction
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Classifications
-
- 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
- D07B1/04—Ropes built-up from fibrous or filamentary material, e.g. of vegetable origin, of animal origin, regenerated cellulose, plastics with a core of fibres or filaments arranged parallel to the centre line
-
- D—TEXTILES; PAPER
- D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
- D04C—BRAIDING OR MANUFACTURE OF LACE, INCLUDING BOBBIN-NET OR CARBONISED LACE; BRAIDING MACHINES; BRAID; LACE
- D04C1/00—Braid or lace, e.g. pillow-lace; Processes for the manufacture thereof
- D04C1/06—Braid or lace serving particular purposes
- D04C1/12—Cords, lines, or tows
-
- 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
- D07B1/00—Constructional features of ropes or cables
- D07B1/20—Buoyant ropes, e.g. with air-filled cellular cores; Accessories therefor
-
- D—TEXTILES; PAPER
- D07—ROPES; CABLES OTHER THAN ELECTRIC
- D07B—ROPES OR CABLES IN GENERAL
- D07B2201/00—Ropes or cables
- D07B2201/10—Rope or cable structures
- D07B2201/1092—Parallel strands
-
- D—TEXTILES; PAPER
- D07—ROPES; CABLES OTHER THAN ELECTRIC
- D07B—ROPES OR CABLES IN GENERAL
- D07B2201/00—Ropes or cables
- D07B2201/10—Rope or cable structures
- D07B2201/1096—Rope or cable structures braided
-
- 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
- D07B2201/2002—Wires or filaments characterised by their cross-sectional shape
- D07B2201/2003—Wires or filaments characterised by their cross-sectional shape flat
-
- 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
-
- D—TEXTILES; PAPER
- D07—ROPES; CABLES OTHER THAN ELECTRIC
- D07B—ROPES OR CABLES IN GENERAL
- D07B2401/00—Aspects related to the problem to be solved or advantage
- D07B2401/20—Aspects related to the problem to be solved or advantage related to ropes or cables
- D07B2401/202—Environmental resistance
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Manufacturing & Machinery (AREA)
- Textile Engineering (AREA)
- Ropes Or Cables (AREA)
- Artificial Filaments (AREA)
- Yarns And Mechanical Finishing Of Yarns Or Ropes (AREA)
Abstract
Abstract of the Disclosure A rope for traction of a double structure of a core member coated with a sheath member, in which the core member com-prises a molecularly oriented shaped article of an ultrahigh molecular weight polyolefin, and the sheath member comprises a braid. The rope disclosed herein is light in weight, floatable on water, easy to handle and excellent in safety to human bodies and weatherability.
Description
` ` 132~1~3 .
TITLE
ROPE FOR TRACTION
~ Technical Field of the Invention The present invention relates to a rope for traction. More particularly, it relates to a rope for . , traction of paragliders, water skies and the like which is - excellent in light weight, safety to human bodies and weatherability.
Background of the Invention ` Metallic ropes and wires have been used for : traction of paragliders, water skies and the like.
However, because of their heavy weight the metallic ropes sink in water and it is not easy to handle them. Further, : they pose problems in that due to their reduced elongation under tensile stre~s shocks upon traction directly affect ; the ob~ect being pulled which might be in~ured by a sudden shock, and that because of their poor shock-absorbing properties the ropes themselves might be in~ured and broken.
- O~bect of the Invention The invention is to solve the problems associated . with the prior art and an ob~ect of the invention i3 to :`
132~143 provide a rope for traction which is light, floatable on water, easy to handle and excellent in safety to human bodies and weatherability.
Summarv of the Invention A rope for traction according to the invention has a double structure of a core member coated with a sheath member, in which the core member comprises a molecularly oriented shaped article of an ultrahigh molecular welght copolymer, and the sheath member comprises a braid. The ultrahigh molecular weight copolymer is a copolymer of ethylene and alpha-olefin having 3 to 20 carbon atoms containing the alpha-olefin in an amount of 0.1 to 20 moles on average per 1000 carbon atoms of the copolymer and has ~ an intrinsic viscosity of at least 5 dl/g.
-~ The rope for traction according to the invention having a double structure of a core member coated with a sheath member, in which the core member comprises a strong and resilient molecularly oriented shaped article of an ultrahigh molecular weight olefin copolymer, and the sheath member comprises a braid, is floatable on water, easy to handle and excellent in safety to human bodies and weatherability.
The molecularly oriented shaped article has an increased ` elongation under load and an increased amount of energy until break as well as improved shock resistance and creep resistance, 132~143 and in consequence, any sudden shock may be effectively absorbed by the core member without attacking the object being pulled and the rope is prevented from tearing.
Detailed DescriPtion of the Invention :~ The invention will now be described in detail with reference to the attached drawing in which:
Fig. 1 is a partly cut out perspective view of a rope according to the invention.
As shown in Fig. 1, the rope 1 for traction according to the invention has a double structure comprising a core member 2 and a sheath member 3 enveloping the core member 2.
The core member 2 comprises a molecularly oriented ` shaped article of an ultrahigh molecular weight olefin copolymer.
The ultrahigh molecular weight olefin copolymer which can be used herein includes ultrahigh molecular weight copolymers of ethylene and at least one alpha-olefin having from 3 to 20 carbon atoms, - preferably from 4 to 10 carbon atoms such as ultrahigh molecular weight copolymer of ethylene and propylene, ultrahigh molecular weight copolymer of ethylene and 1-butene, ultrahigh molecular weight copolymer of ethylene and 4-methyl-1-pentene, ultrahigh `~ molecular weight copolymer of ethylene and l-hexene, ultrahigh molecular weight copolymer of ethylene and 1-octene and ultrahigh molecular weight copolymer of ethylene and 1-decene. The alpha-olefin mentioned above is contained in the copolymer in an amount of from 0.1 to 20, preferably from 0.5 to 10, more preferably from 1 to 7 molecules on average per 1000 carbon atoms of the copolymer.
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4 132~1~3 The ultrahigh molecular weight olefin copolymer used herein has an intrinsic viscosi~y 1~] of at least 5 dl/g. By the term "ultrahigh molecular weight" is meant that the polyolefin has an intrinsic viscosity [~] of at least 5 dltg. Preferably, the polyolefin used herein has an intrinsic viscosity of from 7 to 30 dl/g.
Such an ultrahigh molecular weight polyolefin can be extruded and strongly drawn to provide a molecularly oriented shaped article such as filaments and tapes which article is light in weight, has increased elastic modulus and tensile strength, and is excellent in water and saline resistance. As described above, the ultrahigh molecular weight copolymer of ethylene and at least one alpha-olefin is particularly preferred for the purpose of the invention, since it can be extruded and strongly drawn at a draw ratio of from 5 to 80, preferably from 10 to 50 to a molecularly oriented shaped article having improved shock and creep resistances in addition to the above-mentioned combination of advantageous properties. Further, the molecularly oriented shaped article made from the ultrahigh molecular weight copolymer of ethylene and at least one alpha-olefin has an improved heat resistance.
The core member 2 of the rope in accordance with the invention comprises a molecularly oriented shaped article of an ultrahigh molecular weight copolymer of ethylene and at least one alpha-olefin having from 3 to 20 carbon atoms.
~,' 132~143 `~` Although the molecularly oriented shaped article constituting the core member 2 is preferably a bundle of aligned drawn filaments or a braid of drawn filaments, it may be in the form of tapes or films drawn in at least one direction.
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, - 6 - 1 32~1 ~3 The molecularly oriented shaped article constituting the core member 2 has a density of from 0.940 to o.g9o, and in particular from 0.960 to 0.985, a~
measured by a conventional density gradient tube method in accordance with ASTM D 1505 at a temperature of 23 C., using carbon tetrachloride and toluene in the density gradient tube.
The molecularly oriented ~haped article u~ed herein has a dielectric constant (1 KHz, 23 C.) of normally from 1.4 to 3.0, and preferably from 1.8 to 2.4, and a dielectric 105s tangent (1 KHz, 80 C.) of from 0.050 to 0.008 %, and preferably from 0.040 to 0.010 %.
The measurements of the dielectric constant and the dielectric loss tangent were carried out on molecularly oriented filaments and tapes compactly aligned in the form of films in accordance with ASTM D 150.
The degree of molecular orientation of the moleculary oriented shaped article may be determined by X-ray diffractometry, birefringence method or fluorescence polarization method. In the case of molecularly oriented filaments of the copolymer of ethylene and at least one alpha-olefin, it is desirable from a view point of their mechanical properties that they have a degree of molecular orientation (F) of at lea~t 0.90, and preferably at least 0.~5, as determined from the half-value width. Such a -:
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.
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132~143 degree of molecular orientation is described in detail, for example by Yukichi GO and Ki-ichiro KUBO, in Kogyo Kagaku Zasshi (Journal of the Society of Industrial Chemistry of Japan), 39, 992 ~193g), that i~, it i~
defined by the following formula:
Degree of Orientation (F) = (90 - 0.5 H )/90 wherein H is a half-value width (in ) of a strength distribution curve along the Debye ring on the ~trongest paratroop on the equator.
;- The molecularly oriented shaped article used herein has excellent mechanical properties. For example, it has, in the form of drawn filaments, an elastic modulus of at least 20 GPa, and in particular at least 30 GPa, and a tensile strength of at least 1.2 GPa, and in particular at least 1.5 GPa.
The molecularly oriented shaped article used . herein has an impulse break down voltage of from 110 to 250 KV~mm, in particular from 150 to 220 KV/mm. The ..:
; impulse break down voltage was measured on the same .~
samples as employed in the measurement of the dielectric constant that was placed on a copper plate, the voltage of which was increased by applying thereto impulses of - negative polarity at a rate of 2 KV/3 steps by means of a - ~ JIS-type bronze electrode having a diameter of 25 mm.
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': ' , The molecularly oriented shaped article made of the above-mentioned ultrahigh molecular weight copolymer of ethylene and at least one alpha-olefin i5 remarkably excellent in shock resistance, breaking energy and creep resistance.
The molecularly oriented shaped article ha3 a breaking energy of at least 8 kg.m/g, in particular at least 10 kg.m/g.
The molecularly oriented shaped article is excellent in creep resistance. In an accelerated test for creep at room temperature, that is, in a test for creep at elevated temperature, it exhibits a remarkably reduced creep. At a temperature of 70 C, and under a load of 30 % of the breaking load, the molecularly oriented shaped article made of the above-mentioned ultrahigh molecular weight copolymer of ethylene and at lea~t one alpha-olefin exhibita a creep elongation (% elongation after gO sec.) of not more than ~ %, and in particular not more than 5 ~, and a creep speed between after periods of 90 sec. and 2~0 sec. ~ 9O 18~ taec 1) of not faster than 4 x 10 4sec 1, and in particular not fa~ter than 5 x 10 5sec 1.
In addition to the above-described properties at room temperature, the molecularly oriented shaped article made of the copolymer of ethylene and at least one alpha-olefin ha3 the following thermal properties.
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132514~
Namely, it has at least one crystal fusion peak (Tp) at a temperature range at least by 20 C. higher than the inherent crystal fusion temperature (Tm) of the copolymer and the fusion heat based on the crystal fusion peak tTp) is at least 15 %, preferably at least 20 %, and more preferably at least 30 %, based on the total fusion heat.
The inherent crystal fusion temperature (Tm) of the above-mentioned copolymer can be determined by a so-called second run in a differential scanning calorimeter, in which the molecularly oriented shaped article of the copolymer i~ once fused completely and cooled thereby moderating the molecular orientation, and thereafter heated again.
More particularly, with respect to the molecularly ., .:
oriented shaped article of the above-mentioned copolymer, no crystal fusion peak appears in the above-mentioned inherent crystal fusion temperature range of the .- copolymer, or even if any peak is observed in this temperature range, it appears only as tailing. The crystal fusion peak (Tp) normally appearR in a te~perature -- o . ~: range of from Tm + 20 C. to Tm + 50 C., and in ... ~ particular in a temperature range of from Tm + 20 C. to ~ Tm + 100 C., and it appears frequently in the form of a - plurality of peaks in the above-mentioned temperature '', ,;
range The crystal fusion peak (Tp) often appears in the form of two separate peaks, that i5, a higher temperature fusion peak (Tp1) in a temperature range of from Tm +
35 C. to Tm +100 C., and a lower temperature fusion peak (Tp2) in a temperature range of from Tm + 20 C. to Tm +
35 C. Depending upon the conditions of the preparation of the molecularly oriented shaped articles, the Tp1 or TP2 comprises a plurality of peaks.
It is considered that the high crystal fusion peaks (Tp1 and Tp2) prominently improve the heat resi~tance of the molecularly oriented shaped article of the ultrahigh molecular weight ethylene/-~ -olefin copolymer and contribute to maintenance of the strength retention ratio or elastic modulus retention ratio at a high level after a heat hysteresis at an elevated temperature.
It is preferred that the fusion heat ba~ed on the higher temperature fusion peak (Tpl) in a temperature - range of from Tm + 35 C. to Tm + 100 C. be at least . j,.~
1.5%, especially at least 3.0 %, based on the total fusion heat.
In the case where the fusion heat ba~ed on the higher temperature fusion peak (Tp1) satisfies the above requirement, even if the higher temperature fusion peak ' (Tpl) does not apear as a projecting main peak, that is, even if the peak (Tpl) is an assemblage of small peaks or a broad peak, excellent creep resistance characteristics can be obtained though it sometimes happens that the heat resistance is somewhat degraded.
The melting point was measured using a differential scanning calorimeter (Model DSC II supplied by Perkin-Elmer Co.). About 3 mg of a sample was kept in the restraint state by winding the sample on an aluminium :
sheet having a size of 4 mm x 4 mm x 0.2 mm (thickness).
Then, the sample wound on the aluminum sheet was ~ealed in an aluminum pan to be placed in a sample holder of a cell.
An aluminum sheet equal to that used for the sample was sealed in an aluminum pan ordinarily kept vacant, to be placed in a reference holder of the cell, whereby a heat balance was kept. The cell was held at 30 C. for about 1 :j minute, and then, the temperature was elevated to 250 C.
at a rate of 10 C./min. and the measurement of the ::
melting point of the sample at the first temperature elevation was completed. Subsequently, the sample was held at 250 C. for 10 minutes. Then, the temperature was lowered at a rate of 20 C./min. and the sample was held at 30 C. for 10 minutes. Then, the temperature was elevated to 250 C. again at a rate of 10 C./min., and the measurement of the melting point at the xecond 13251~3 temperature elevation (second run) was completed. The maximum value of the fusion peak was designated a~ the melting point. When the peak appeared as a shoulder, tangential lines were drawn at the bending points on the low temperature side and high temperature side ~ust close to the shoulder, and the intersection point was designated as the melting point.
A base line connecting points of 60 C. and 240 C. in the endothermic curve was drawn, and a vertical line was drawn at a point higher by 20 C. than the inherent crystal fusion temperature (Tm) of the copolymer determined as the main fusion peak at the second temperature elevation. A low temperature portion ~urrounded by these lines an area surrounded by the base line, vertical line and endothermic curve including the point of 60 C. was regarded as being based on the inherent crystal fusion (Tm) and the high temperature :
i portion an area surrounded by the base line, vertical line and the endothermic curve including the point of 240 C.was regarded as being based on the crustal fusion (Tp) manifesting the functions of the molecularly oriented shaped article copolymer. The crystal fusion heats were calculated from areas of these portions. According to the above-mentioned method, the portion between vertical lines at Tm + 20 C. and at Tm +35 C. was regarded as being '' 13251~
based on the fusion of TP2 and the high temperature portion was regarded as being based on the fusion of Tpl, and the heata based on the fusion of Tp1, and the heats based on the fusion of Tp1 and the fusion of TP2 were similarly calculated from the areas of these portions.
The molecularly orlented filaments of the above-mentioned ultrahigh molecular weight copolymer of ethylene and at least one alpha-olefin have a strength retention of at least 95 %, and an elastic modulus retention of at least 90 X, in particular at least 95 %, after a heat hysteresis of 170 C., for a period of 5 minutes, indicatlng the fact that they have a prominently superior heat resistance which are not found in drawn filaments of ultrahigh molecular weight polyethylene.
ProceQs for the preparation of a molecularly oriented shaped article of an ultrahlgh molecular weight polyolefin Generally, a molecularly oriented shaped article having high elastic modulus and high strength can be prepared by extrudlng an ultrahlgh molecular weight polyolefin into filaments, tape or the like and ~trongly drawing the exrudate. Such a proces~ per Qe is known in the art.
For examplo, Japane4e Patent ~lrrr~as~-n Lald-Open P~kc~
14 132~1~3 72932-17 Speciflcatlon No. 15408/81 dlscloses a process comprlslng splnnlng a dllute solutlon of ultrahlgh molecular welght polyethylene and drawlng the obtalned fllaments. Japanese Patent Lald-Open Publlcatlon Speclflcatlon No. 130313/84 dlscloses a process com-prlslng melt-kneadlng ultrahlgh molecular welght polyethylene wlth a wax, extruding the kneaded mlxture, coollng and solldlfylng the extrudate and drawlng the solldlfled extrudate. Furthermore, Japanese Patent Lald-Open Publlcatlon Speclflcatlon No. 187614/84 dlscloses a process comprislng extrudlng the abovementloned melt-kneaded mlxture, draftlng the extrudate, then coollng and solldl-fylng the extrudate and drawlng the solldlfled extrudate.
;~ A process for the preparatlon of a molecularly orlented shaped artlcle of a preferred ultrahlgh molecular welght poly-olefln, that ls, an ultrahlgh molecular welght copolymer of ethy-lene and at least one alpha-olefln, wlll now be descrlbed ln detall.
PreParatlon of the CoPolYmer The ultrahlgh molecular welght ethylene/a-olefln copoly-mer ls obtalned, for example, by slurry-polymerlzlng ethylene and at least one a-olefln havlng from 3 to 20, preferably from 4 to 10 carbon atoms ln an organlc solvent ln the presence of a Zlegler ~ catalyst.
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13251~3 Examples of the preferred ~(-olefin include, for example, butene-1, pentene-1, 4-methylpentene-1, hexene-1, heptene-l and octene-1. Of these, 4-methyl-pentene-1, hexene-1 and octene-1 are particularly preferred. The~ -olefin comonomer should be used in such an amount that the 1 -olefin content per 1000 carbon atoms in the polymer chain is within the above-mentioned range. Moreover, the ultrahigh molecular weight ethylene/~ -olefin copolymer ,..,'.s should have a molecular weight corresponding to the above-mentioned intrinsic viscosity ] -;.~ (.
In the ultrahigh molecular weight ethylene/~ -olefin copolymer used herein, the determination of the ~ -olefin component is carried out using an infrared - ~pectrophotometer (supplied by Nippon Bunko Kogyo~.
Namely, the ab~orbance at 13~8 cm 1, which indicates the deformation vibration of the methyl group of the ~ -olefin included in the ethylene chain, i~ meaqured, and the measured value is converted to the number of the methyl branche~ per 1000 carbon atoms using a calibration curve prepared in advance using a model compound in a 1 C
- nuclear magnetic resonance spectroscopy.
' Preparation of the molecularly oriented ~ shaped article ':
Upon preparation of the molecularly oriented shaped article of the ultrahigh molecular weight ethylene/
-olefin copolymer, a diluent is incorporated in the copolymer. A solvent for the ultrahigh molecular weight ethylene copolymer or a wax having a compatibility with the ultrahigh molecular weight ethylene copolymer is used as the diluent.
A solvent having a boiling point higher, especially by at least 20 C, than the melting point of the above-mentioned copolymer is preferably used as the solvent.
. As specific examples of the solvent, there can be mentioned aliphatic hydrocarbon solvents such as n-nonane, n-decane, n-undecane, n-dodecane, n-tetradecane, n-octadecane, liquid paraffin and kerosine, aromatic hydrocarbon solvents and hydrogenated products thereof such as xylene, naphthalene, tetralin, butylbenzene, p-cumene, cyclohexylbenzene, diethylbenzene, benzylbenzene, :.
dodecylbenzene, bicylohexyl, decalin, methylnaphthalene and ethylnaphthalene, halogenated hydrocarbon solvents such as 1,1,2,2-tetrachloroethane, pentachloroethane, hexachlorobenzene, 1,2,3-trichloropropane, dichlorobenzene, 1,2,4-trichlorobenzene and bromobenzene, and mineral oils such as paraffinic process oil, naphthenic process oil and aromatic process oil.
132S1~3 Aliphatic hydrocarbon compounds and derivatives thereof can be used as the wax.
A so-called paraffinic wax composed mainly of a saturated aliphatic hydrocarbon compound having a molecular weight lower than 2000, preferably lower than lOoo, especially preferably lower than 800, is mentioned ~,.
as the aliphatic hydrocarbon compound. As speciflc examples of the aliphatic hydrocarbon compound, there can be mentioned n-alkanes having at least 22 carbon atoms, such as docosane, tricosane, tetracosane and triacontane, mixtures comprising an n-alkane as mentioned above as the main component and a lower n-alkane, so-called paraffin waxes and ethylene copolymer waxes, which are low-molecular-weight polymers obtained by homopolymerizing ethylene or copolymerizing ethylene with othero(-olefin, waxes formed by reducing the molecular weight of polyethylene such as medium-pressure, low-pressure or high-pressure poleythylene by thermal degradation, and oxidized waxes and maleic acid-modified waxes obtained by oxidizing the foregoing waxes or modifying the foregoing waxes with maleic acid.
As the aliphatic hydrocarbon compound derivative, there can be mentioned, for example, fatty acids, aliphatic alcohols, fatty acid amides, fatty acid eRters, aliphatic mercaptans, aliphatic aldehydeR and aliphatic 132~14~
ketons having at least 8 carbon atoms, preferably from 12 to 50 carbon atoms, and a molecular weight of from 130 to 2000, preferably from 200 to 800, in which at lea~t one, preferably 1 or 2, especially preferably one functional group such as a carboxyl group, a hydroxyl group, a carbamoyl group, an ester group, a mercapto group or a carbonyl group is contained at the end or in the interior of an aliphatic hydrocarbon group such as an alkyl group or an alkenyl group.
As specific examples, there can be mentioned fatty acids such as capric acid, lauric acid, myristic acid, palmitic acid, stearic acid and oleic acid, aliphatic alcohols such as lauryl alcohol, myristyl alcohol, cetyl alcohol and stearyl alcohol, fatty acid amides such as capric amide, lauric amide, palmitic amide and stearyl amide, and fatty acid esters such as stearyl acetate.
The ultrahigh molecular weight ethylene copolymer/diluent mixing ratio varies depending upon the kind~ of the~e components, but it is generally preferred that this mixing ratio be from 3/97 to 80/20, especially from lS/75 to 60/40. If the amount of the diluent is too small and below the above-mentioned range, the melt viscosity becomes too high and melt kneading or melt shaping is difficult, and surface roughening of the shaped article is conspicuous and breaking is often cau~ed at the '.~' . ~ ~
drawing step. If the amount of the diluent is too large and exceeds the above-mentioned range, melt-kneading becomes difficult and the drawability of the shaped article is insufficient.
It is generally preferred that melt kneading be carried out at a temperature of from 150 to 300 C, especially from 170 to 2~0 C. If melt kneading is carried out at a lower temperature, the melt viscosity is too high and melt shaping becomes difficult. If the temperature is too high and exceeds the above-mentioned range, the molecular weight of the ultrahigh molecular weight ethylene copolymer is reduced by thermal degradation and it becomes difficult to obtain a shaped article having high elastic modulus and high strength.
Mixing can be performed by dry blending using a Henschel mixer or a V-blender or by melt mixing using a single screw or multiple-screw extruder.
Melt shaping of a dope comprising the copolymer and diluent is generally performed by melt extrusion. For example, filaments are obtained by melt extrusion of such a dope through a spinneret. The filaments as extruded through the spinneret may be drafted, that is, Qtretched in the molten state. The draft ratio can be defined by the following formula:
draft ratio - V/Vo .,~
'' 132~143 wherein Vo stands for the extrusion speed of the molten resin in a die orifice, and V stands for the winding speed of the cooled and solidified undrawn filaments.
While the draft ratio depends on the temperature of the mixture and the molecular weight of the ultrahigh molecular weight ethylene copolymer, it may be at least 3, preferably at least 6.
The so-obtained undrawn shaped article of the ultrahigh molecular weight ethylene copolymer is sub~ected to a drawing treatment. Of course, the degree of the drawing treatment is such that molecular orientation in at least one axial direction can be effectively imparted to the copolymer.
It is generally preferred that drawing of the shaped article of the ultrahlgh molecular weight ethylene copolymer be carried out at a temperature of from 40 to 160 C, preferably from 80 to 145 C. Any of air, water steam and liquid media can be used as the heating medium for heating and maintaining the undrawn shaped article at the above-mentioned temperature. If a solvent capable of eluting and removing the above-mentioned diluent, which has a boiling point higher than the melting point of the composltion of the shaped article, for example, decalin, æ
decane, kero~lne or the llke, i5 u~ed a~ the heating .
., medium for the drawing operation, removal of the above-mentioned diluent becomes possible, and drawing unevenness can be eliminated at the drawing step and a high draw ratio can be attained.
Of course, the means for removing the exces~ive diluent from the ultrahigh molecular weight ethylene copolymer i5 not limited to the above-mentioned method.
For example, there may be adopted a method in which the undrawn shaped article is treated with a solvent such as hexane, heptane, hot ethanol, chloroform or benzene and then drawn, and a method in which the drawn shaped article is treated with a solvent such as hexane, heptane, hot ethanol, chloroform or benzene. According to these methods, the exces~ive diluent can be effectively removed and a drawn product having a high elastic modulus and a high strength can be obtained.
The drawing operation may be carried out in one stage or a plurality of stages. The draw ratio dependR on the desired molecular orientation and the resulting improvement of the fusion temperature, but in general, satisfactory reRults are obtained if the drawing operation is carried out at a draw ratio of from 5 to 80, e~pecially from 10 to 50.
In general, drawing in a plurality of stages is advantageous, and there is preferably adopted a method in ~ - 22 -132~143 which at the first stage, the drawing operation is carried out at a relatively low temperature of from 80 to 120 C
while extracting the diluent from the extruded shaped article and at the second and subsequent stages, the operation of drawing is conducted at a temperature of from 120 to 160 C, which is higher than the drawing temperature adopted at the first stage.
Uniaxial drawing of filaments or tape is accomplished by performing the drawing operation between rollers differing in the peripheral speed.
The so-obtained molelcularly oriented ~haped article can be heat-treated under a restraint condition, if de~ired. This heat treatment is carried out at a temperature of from 140 to 170 C, especially from 150 to 175 C, for a period of from l to 20 minute~, especially from 3 to 10 minutes. By this heat treatment, crystallization of the oriented crystalline portion is further advanced, and the crystal fusion temperature is shifted to the high temperature side, the strength and ela~tic modulus are improved and the creep resistance at elevated temperatures is improved.
The rope l for traction accordlng to the invention has a double ~tructure of a core member 2 coated with a sheath member 3, in which the core member 2 compri~es a molecularly oriented shaped article such as filaments and : .
tapes of an ultrahiqh molecular weight copolymer of ethylene and at least one alpha-olefin, and the sheath member 3 comprises a braid. The core member 2 preferably comprises a bundle of aligned drawn filaments of the ultrahigh molecular weight polyolefin, or a braid made thereof. The braid may be made of a single bundle of drawn filaments. Alternatively, a number of bundles of drawn filaments, for example, 3, 4, 6 or 8 bundles of drawn filaments - may be twisted together and then braided to provide the core member 2. Further, the core member may be a parallel lay rope.
- 10 Depending upon the intended use and object of the rope, the diameter of the bundle of drawn filaments and the number of the bundles to be twisted together may be selected.
The core member 2, in the form of a braid, of the rope according to the lnvention preferably has a diameter ranging from 2 to 15 mm and a breaking energy of at least 3 kg.m/g, and ln particular at least 4 kg.m/g. One of the advantages of the molecularly orlented shaped artlcle used herein resides in the fact that braiding reduction in available strength (spinning loss) is low.
The sheath member 3 comprises a braid of yarns of strands of conventional naturally occurrlng or synthetlc fibers.
Examples of usable fibers include, for example, ', ' ` 132~143 polyester fibers, acrylic fibers, cotton, polypropylene fibers, polyethylene fibers, polyamide fibers, rayon (viscose and cupra), linen and Vinylon fibers.
The number of yarns or strands for braiding the sheath member 3 and the thickness of the sheath member 3 may be selected depending upon the intended use of the rope. Normally, the thickness of the sheath member is preferably of the order of form 0.1 to 2 mm.
The rope according to the invention can be prepared by a double braiding method known per se. For example, during or after formation of the core member 2 by aligning or braiding a bundle of bundles of molecularly oriented filaments of an ultrahigh molecular weight polyolefin, the core member is wrapped around helically with inter~ecting yarns of strands so that they may be braided into an enveloping sheath member 3.
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Effect of the Invention The rope for traction according to the invention has a double structure of a core member coated with a sheath member, in which the core member comprlses a light in weight, strong and resilient molecularly oriented ~haped article of an ultrahigh molecular weight polyolefin, and the sheath member comprises a braid, and in con~equence, it is floatable on water and easy to . .
132~1~3 handle, and is excellent in safety to human bodies and weatherability.
Example 1 (Polymerization for Preparation of Ultrahigh Molecular Weight ~thylene/Butene-l Copolymer) Slurry polymerization for forming an ultrahigh molecular weight ethylene/butene-1 copolymer was carried out in 1 Q of n-decane as a polymerization solvent in the presence of a Ziegler catalyst. A monomer mixture gas comprising ethylene and butene-1 at a molar ratio of 9~.2/2.35 was continuously supplied to a reactor so that the pressure inside the reactor iY kept constant at 5 kg/cm2. The slurry polymerization carried out at a ; reaction temperature of ~0C was completed in 2 hours.
: The yield of a powdery ultrahigh molecular weight ethylene/butene-1 copolymer was 160g, an intrinsic : viscosity (at i35 C in decalin) of the copolymer was 8.2dl/g, and the butene-1 content determined by an infraredspectrometer was 1.5 butene-1 molecules per 1000 carbon atoms . IPreparation of Drawn and Oriented product of . Ultrahigh Molecular Weight ~thylene/Butene-l Copolymer) A mixture comprising 20 parts by weight of the powdery ultrahigh molecular weight ethylene/butene-1 copolymer obtained by the above-mentioned polymerization and 80 parts by weight of a paraffin wax (melting point = 69C, molecular weight = 490) was melt-spun under the following conditions.
To 100 parts by weight of the above-mentioned filament mlxture was added 0.1 part by weight of 3,5-di-tert-butyl-4-hydroxy-toluene as a process stabilizer. The mixture was then melt-kneaded at a set temperature of 190 C., using a screw type extruder (screw diameter = 25 mm, L/D = 25, manufactured and sold by Thermoplastics Co.).
Subsequently, the molten mixture was melt spun through a spinning die having an orifice diameter of 2 mm, ~
splnnlng die being attached to the extruder. The extruded melt was taken at a draft ratio of 36 times with an air gap of 180 cm, cooled and solidlfied in the air to provide an undrawn filament. The undrawn filament was then drawn under the following conditions.
Two-staged drawing wa carried out using three godet rolls. A heating medium employed in a first drawing tank wa~ n-decane and the temperature wa~ 110C, and a heating mediu~ employed in a ~econd drawing tank was triethylene glycol and the temperature was 145C. The effectlve length of each tank was 50 cm. The undrawn filament was drawn with a first godet roll operated at a 2~t - 2~ --~ 132~1~3 rotation speed of 0.5 m/min while adjusting a rotation speed of a third godet roll to provide an oriented filament of a desired draw ratio. A rotation speed of a second godet roll was suitably selected so that a stable drawing operation is made possible. Substantially all of the paraffin wax initially added was extracted ~n n-decane from the filament at a stage in which it is drawn. The oriented filament was then washed with water and dried a whole day and night at room temperature and under reduced pressure, followed by determination of physical properties thereof. Incidentally, the draw ratio was calculated from the ratio of the rotation speed between the first and third godet rolls.
(Measurement of Tensile Characteristics) The oriented filament was tested for its elastic modulus and tensile strength at room temperature (23C) using a tensile tester (Model DCS-50M manufactured and sold by Shimadzu Seisakusho). The sample was a bundle of 100 filaments each having a thickness of 10 denier.
In that case, a sample length employed between clamps was 100 mm, and a rate of pulling employed was lOOmm/min (a rate of strain of 100%/min). The elaRtic modulus was an initial elastic modulus calculated from a tangential gradient of the stress-strain curve. A
sectional area necessary for the calculation was obtained 13251~.~
by calculation from a weight of the sample, assuming the density of the sample as 0.960g/cc.
(Tensile Elastic Modulus Retension and Strength Retention after Heat Hysteresis) A heat hysteresis test was carried out by allowing a sample to stand still in a gear oven ~Perfect Oven manufactured and sold by Tabai Seisakusho).
;" The sample having a length of about 3 m was wound repeatedly on a stainless steel frame having a plurality of blocks attached to both ends thereof, and both ends of the ~ample were fixed. In that case, both ends of the sample were fixed to such an extent that the sample does not ~ag, and no positive tension was imposed on the sample. Tensile characteristics of the sample after the heat hysteresis test were determined according to the procedure as described in the aforementioned measurement of tensile characteristics.
; (Measurement of Creep Resistance) The drawn and oriented filament was tested for its creep resistance using a thermal stress distortion measurement apparatus (Model TMA/SS10 manufactured and sold by Seiko Denshi Kogyo), wherein the sample length was 1 cm, ambient temperature was 70C, and mea~urement was ;~ conducted under an accelerated condition by applying to the sample a load corresponding to 30 % of a breaking load `:
- 2~ -at room temperature. In order to evaluate a creep quantltatively, the following two values were determined, That i~, there were determlned values of a creep elongation CRgo~X) at the time 90 seconds after application of the load, and of an average creep speed ., --1 (sec ) between the time 90 second~ after application of the load and the time lB0 seconds after the above-mentioned time.
: Tensile characteristics of the bundle of drawn and oriented filaments are shown ln Table 1.
~; Table 1 Sample Filament Draw Strength Elastic Elon- Degree of denier/ ratiomo~ulu~ gation orien-filaments tation (GPa) ~GPa) (%) ~F) ....~
Sample 1000/ 22.3 2.4 60 5.50 0.975 The lnherent crystal fuslon peak of the drawn and oriented fllament (~ample-l) of the ultrahigh molecular welght ethylene/butene-1 copolymer appeared at 126.~C, and the proportion of fusion peak based on Tp to the total - crystal fusion heat wa4 33.8X. The creep reslstance ~ i .
' ~., characteristics were such that CRgo was 3.1% and was 3.03 X 10 5 sec 1 After the heat hysteresis at 170C for 5 minutes, the elastic modulus retention ratio was 102.2%, and the strength retention ratio was 102.5%, showing no decrease in performance of the drawn and oriented filament.
Furthermore, physical properties of this drawn and oriented filaments were such that the amount of work necessary for rupture of the filament was 10.3 kg~m/g, the density was 0.973 g/cm3, the dielectric constant was 2.2, the dissipation loss tangent was 0.024%, and the impulse breakdown voltage was 180KV/mm.
A traction rope according to the present invention, which comprises the following core and sheath members was prepared.
Core member:
~ n eight bundle plaited rope having a thickness of 12,000 denier made of ultrahigh molecular weight ethylene/butene-1 copolymer filaments (sample-1).
Sheath member:
A sheath member was obtained by plaiting polye~ter spun yarns each having a thickness of 1,000.
Morphological and physical properties of the rope thus prepared are shown in Table 2.
Table 2 __ I
Sampl~ Core Wall Unit Breaking Breaking Amount of energy diameter thickness weight strength elongation required for bringing of sheath about breakage (mm) (mm) (g/m) (Ton) (%) (kg m/g) ___ . __ ___ - Sampl l -lA 4.0 0.5 12 2.0 6.5 5.40 __ __ _ _ Example 2 (Polymerization for Preparation of Ultrahigh Molecular Weight Ethylene/Octene-1 Copolymer) Slurry polymerization of ethylen was carried out in the presence of a Z~egler catalyst in 1 Q of n-decane as a polymerization solvent. In that case, 125 ml of octene-1 as a comonomer and 40 Nml of hydrogen as a molecular weight-adjusting agent were collectively added, prior to the intiation of the polymerization, to the system, and the polymerization was then allowed to proceed. Ethylene gas was continuously supplied to a reactor so that the pressure inside the reactor is kept constant at 5kg/cm2 and the polymerization was completed in 2 hours at 70C. The yield of powdery ultrahigh molecular weight ethylene/octene-l copolymer obtained was ....
132~143 178g, the Intrlnsic viscosity ~] ~at 135 C in decalin) was 10.66dl/g, and the octene-1 content as determined by an infrared spectrophotometer was 0.5 octene-1 molecule per 1000 carbon atmos.
(Preparation and Physical properties of Drawn and Oriented product of Ultrahigh molecular weight ~thylene/Octene-l Copolymer) Drawn and oriented filaments were prepard from the ethylene/octene-1 copolymer thus obtained in the sa~e manner as described in ~xample 1. Tensile characteristics of a bundle of the drawn and oriented filaments obtained are shown in Table 3.
Table 3 Samplt Filament Draw Strength elastic ~lon- Degree of V Denler/ ratlo mo~ul ~ gation orien-Fllaments tation (GPa) (GPa)(X) (F) Sampl~ 1000/ 16.02.3 65 5.40 0.978 .' ..
':
The inherent crystal fuslon peak of the drawn and - orlented filanenta (sample-2) of the ultrahigh molecular : ~, ..r .
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weight ethylene/octene-1 copolymer appeared at 132.1 C, and proportions of fusion heat based on Tp and Tp1 to the total crystal fusion heat were 9~.~% and 5.0%, respectively. The creep resistance characteristics of the sample-2 were such that CRgo was 2.0% and ~ was 9.50 X 10 sec 1. After heat hysteresis at 170C for 5 minutes, the ela~tic modulus retention was 108.2% and the strength retention was 102.1%. Furthermore, physical properties of the sample-2 were such that the amount of work necessary for rupture of the filament was lO.lRg m/g, the density was 0.971g/cm3, the dielectric constant was 2.2, the dissipation losq tangent was 0.031%, and the impulse breakdown voltage was 185KV/mm.
A traction rope according to the present invention was obtained in the same manner as descri~ed in ~xample 1 using the drawn and oriented filaments (sample-2) of the ultrahigh molecular weight ethylene/octene-1 copolymer thus obtained. Morphological and physical properties of the rope obtained are shown in Table 4.
' Table 4 __ _ . _ _ Sample Core Wall Unit Breaking Breaking Amount of energy diameter thicknesq weight strength elongation required for bringing of sheath about breakage ~mm) ~mm) ~g/m) (Ton) (~) (kg~m/g) _ ;ample -2A 4.0 0.5 12 2.0 6.3 5.20 Example 3 A powdery mixture comprising 20 parts by weight of `; a ultrahigh molecular weight polyethylen(homopolymer) having an intrinsic viscosity of t~]=7.42 dl/g as measured at 135C in decalin and 80 parts by weight of a parrafin wax having a melting point of 69C and a molecular weight of 490 was melt-spun and drawn in the same manner as described in Example 1 to obtain a drawn and oriented filament. Tensile characteristics of a bundle of the drawn and oriented filaments thus obtained are shown in " Table 5.
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132~143 Table 5 .
Sample Filament Draw Strength Elastic ~lon- Degree of denler/ ratio modulu~ gation orien-filaments tatlon (GPa)(GPa) (X) (F) Sampl~ lOOOt 23.12.590 4.10 0.9B0 The inherent crystal fusion peak of the drawn and oriented filaments (sample-3) of the ultrahigh molecular - wel~ht poly~thylene wa~ 136.1C, and a proportion of fusion heat based on Tp to the total crystal fusion heat was 8.8X. Whereas, a proportion of fusion heat based on Tp1 on the higher temperature side to the total cry~tal fusion heat wais less than lX. The creep resistance characteristics were such that CRgo was ll.9X and ~ wa~
1.07 X 10 3 sec 1. After heat hysteresis at 170C for 5 minutes, the elastic modulus retention was 80.4% and the strength retention was 78.2X. Furthermore, physical properties of the sample-3 were such that the amount of work neces~ary for rupture of the filament was 10.2Kg m/g, the density was 0.985g~cm3, the dielectric constant was 2.3, the diasipation loss tangent was 0.030%, and the "~ .
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impulse breakdown voltage was lB2KV/mm.
A traction rope of the present invention was obtained in the same manner as described in ~xample 1 using the drawn and oriented filaments (sample-3) of the ultrahlgh molecular weight polyethylene. Morphological and physical properties of the rope obtained are shown in Table 6. Table 6 Sampl~ Core Wall Unit Breaking ~reaking Amount of energy dlameter thlcknesa welght strength elongation required for bringin of sheath about rapture ~mm)~mm) (g/m) tTon) (%) ~g-m/g) . _ Sampl~
- -3A 4.00.5 13 1.9 4.7 3.51 , .
Comparative ~xample 1 A traction rope was prepared using a400 denier drawn filaments of Kebleri~29 ~aramid fiber produced by Du Pont) as a core in place of the core member described in ~xample 1. Morphological and physlcal properties of the rope thu~ obtalned are shown ln Table ~.
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. -37-Table 7 Sample Core Wall Unit Breaking Breaking Amount of energy diameter thicknes~ weight strength elongation required for bringing of sheath about rapture (mm) (mm)~g/m) (Ton) (%) (kg m/g) ___ Sampl~
-4A 3 8 0.5 12 1.9 3.6 2.80 ~".
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TITLE
ROPE FOR TRACTION
~ Technical Field of the Invention The present invention relates to a rope for traction. More particularly, it relates to a rope for . , traction of paragliders, water skies and the like which is - excellent in light weight, safety to human bodies and weatherability.
Background of the Invention ` Metallic ropes and wires have been used for : traction of paragliders, water skies and the like.
However, because of their heavy weight the metallic ropes sink in water and it is not easy to handle them. Further, : they pose problems in that due to their reduced elongation under tensile stre~s shocks upon traction directly affect ; the ob~ect being pulled which might be in~ured by a sudden shock, and that because of their poor shock-absorbing properties the ropes themselves might be in~ured and broken.
- O~bect of the Invention The invention is to solve the problems associated . with the prior art and an ob~ect of the invention i3 to :`
132~143 provide a rope for traction which is light, floatable on water, easy to handle and excellent in safety to human bodies and weatherability.
Summarv of the Invention A rope for traction according to the invention has a double structure of a core member coated with a sheath member, in which the core member comprises a molecularly oriented shaped article of an ultrahigh molecular welght copolymer, and the sheath member comprises a braid. The ultrahigh molecular weight copolymer is a copolymer of ethylene and alpha-olefin having 3 to 20 carbon atoms containing the alpha-olefin in an amount of 0.1 to 20 moles on average per 1000 carbon atoms of the copolymer and has ~ an intrinsic viscosity of at least 5 dl/g.
-~ The rope for traction according to the invention having a double structure of a core member coated with a sheath member, in which the core member comprises a strong and resilient molecularly oriented shaped article of an ultrahigh molecular weight olefin copolymer, and the sheath member comprises a braid, is floatable on water, easy to handle and excellent in safety to human bodies and weatherability.
The molecularly oriented shaped article has an increased ` elongation under load and an increased amount of energy until break as well as improved shock resistance and creep resistance, 132~143 and in consequence, any sudden shock may be effectively absorbed by the core member without attacking the object being pulled and the rope is prevented from tearing.
Detailed DescriPtion of the Invention :~ The invention will now be described in detail with reference to the attached drawing in which:
Fig. 1 is a partly cut out perspective view of a rope according to the invention.
As shown in Fig. 1, the rope 1 for traction according to the invention has a double structure comprising a core member 2 and a sheath member 3 enveloping the core member 2.
The core member 2 comprises a molecularly oriented ` shaped article of an ultrahigh molecular weight olefin copolymer.
The ultrahigh molecular weight olefin copolymer which can be used herein includes ultrahigh molecular weight copolymers of ethylene and at least one alpha-olefin having from 3 to 20 carbon atoms, - preferably from 4 to 10 carbon atoms such as ultrahigh molecular weight copolymer of ethylene and propylene, ultrahigh molecular weight copolymer of ethylene and 1-butene, ultrahigh molecular weight copolymer of ethylene and 4-methyl-1-pentene, ultrahigh `~ molecular weight copolymer of ethylene and l-hexene, ultrahigh molecular weight copolymer of ethylene and 1-octene and ultrahigh molecular weight copolymer of ethylene and 1-decene. The alpha-olefin mentioned above is contained in the copolymer in an amount of from 0.1 to 20, preferably from 0.5 to 10, more preferably from 1 to 7 molecules on average per 1000 carbon atoms of the copolymer.
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4 132~1~3 The ultrahigh molecular weight olefin copolymer used herein has an intrinsic viscosi~y 1~] of at least 5 dl/g. By the term "ultrahigh molecular weight" is meant that the polyolefin has an intrinsic viscosity [~] of at least 5 dltg. Preferably, the polyolefin used herein has an intrinsic viscosity of from 7 to 30 dl/g.
Such an ultrahigh molecular weight polyolefin can be extruded and strongly drawn to provide a molecularly oriented shaped article such as filaments and tapes which article is light in weight, has increased elastic modulus and tensile strength, and is excellent in water and saline resistance. As described above, the ultrahigh molecular weight copolymer of ethylene and at least one alpha-olefin is particularly preferred for the purpose of the invention, since it can be extruded and strongly drawn at a draw ratio of from 5 to 80, preferably from 10 to 50 to a molecularly oriented shaped article having improved shock and creep resistances in addition to the above-mentioned combination of advantageous properties. Further, the molecularly oriented shaped article made from the ultrahigh molecular weight copolymer of ethylene and at least one alpha-olefin has an improved heat resistance.
The core member 2 of the rope in accordance with the invention comprises a molecularly oriented shaped article of an ultrahigh molecular weight copolymer of ethylene and at least one alpha-olefin having from 3 to 20 carbon atoms.
~,' 132~143 `~` Although the molecularly oriented shaped article constituting the core member 2 is preferably a bundle of aligned drawn filaments or a braid of drawn filaments, it may be in the form of tapes or films drawn in at least one direction.
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, - 6 - 1 32~1 ~3 The molecularly oriented shaped article constituting the core member 2 has a density of from 0.940 to o.g9o, and in particular from 0.960 to 0.985, a~
measured by a conventional density gradient tube method in accordance with ASTM D 1505 at a temperature of 23 C., using carbon tetrachloride and toluene in the density gradient tube.
The molecularly oriented ~haped article u~ed herein has a dielectric constant (1 KHz, 23 C.) of normally from 1.4 to 3.0, and preferably from 1.8 to 2.4, and a dielectric 105s tangent (1 KHz, 80 C.) of from 0.050 to 0.008 %, and preferably from 0.040 to 0.010 %.
The measurements of the dielectric constant and the dielectric loss tangent were carried out on molecularly oriented filaments and tapes compactly aligned in the form of films in accordance with ASTM D 150.
The degree of molecular orientation of the moleculary oriented shaped article may be determined by X-ray diffractometry, birefringence method or fluorescence polarization method. In the case of molecularly oriented filaments of the copolymer of ethylene and at least one alpha-olefin, it is desirable from a view point of their mechanical properties that they have a degree of molecular orientation (F) of at lea~t 0.90, and preferably at least 0.~5, as determined from the half-value width. Such a -:
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132~143 degree of molecular orientation is described in detail, for example by Yukichi GO and Ki-ichiro KUBO, in Kogyo Kagaku Zasshi (Journal of the Society of Industrial Chemistry of Japan), 39, 992 ~193g), that i~, it i~
defined by the following formula:
Degree of Orientation (F) = (90 - 0.5 H )/90 wherein H is a half-value width (in ) of a strength distribution curve along the Debye ring on the ~trongest paratroop on the equator.
;- The molecularly oriented shaped article used herein has excellent mechanical properties. For example, it has, in the form of drawn filaments, an elastic modulus of at least 20 GPa, and in particular at least 30 GPa, and a tensile strength of at least 1.2 GPa, and in particular at least 1.5 GPa.
The molecularly oriented shaped article used . herein has an impulse break down voltage of from 110 to 250 KV~mm, in particular from 150 to 220 KV/mm. The ..:
; impulse break down voltage was measured on the same .~
samples as employed in the measurement of the dielectric constant that was placed on a copper plate, the voltage of which was increased by applying thereto impulses of - negative polarity at a rate of 2 KV/3 steps by means of a - ~ JIS-type bronze electrode having a diameter of 25 mm.
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': ' , The molecularly oriented shaped article made of the above-mentioned ultrahigh molecular weight copolymer of ethylene and at least one alpha-olefin i5 remarkably excellent in shock resistance, breaking energy and creep resistance.
The molecularly oriented shaped article ha3 a breaking energy of at least 8 kg.m/g, in particular at least 10 kg.m/g.
The molecularly oriented shaped article is excellent in creep resistance. In an accelerated test for creep at room temperature, that is, in a test for creep at elevated temperature, it exhibits a remarkably reduced creep. At a temperature of 70 C, and under a load of 30 % of the breaking load, the molecularly oriented shaped article made of the above-mentioned ultrahigh molecular weight copolymer of ethylene and at lea~t one alpha-olefin exhibita a creep elongation (% elongation after gO sec.) of not more than ~ %, and in particular not more than 5 ~, and a creep speed between after periods of 90 sec. and 2~0 sec. ~ 9O 18~ taec 1) of not faster than 4 x 10 4sec 1, and in particular not fa~ter than 5 x 10 5sec 1.
In addition to the above-described properties at room temperature, the molecularly oriented shaped article made of the copolymer of ethylene and at least one alpha-olefin ha3 the following thermal properties.
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132514~
Namely, it has at least one crystal fusion peak (Tp) at a temperature range at least by 20 C. higher than the inherent crystal fusion temperature (Tm) of the copolymer and the fusion heat based on the crystal fusion peak tTp) is at least 15 %, preferably at least 20 %, and more preferably at least 30 %, based on the total fusion heat.
The inherent crystal fusion temperature (Tm) of the above-mentioned copolymer can be determined by a so-called second run in a differential scanning calorimeter, in which the molecularly oriented shaped article of the copolymer i~ once fused completely and cooled thereby moderating the molecular orientation, and thereafter heated again.
More particularly, with respect to the molecularly ., .:
oriented shaped article of the above-mentioned copolymer, no crystal fusion peak appears in the above-mentioned inherent crystal fusion temperature range of the .- copolymer, or even if any peak is observed in this temperature range, it appears only as tailing. The crystal fusion peak (Tp) normally appearR in a te~perature -- o . ~: range of from Tm + 20 C. to Tm + 50 C., and in ... ~ particular in a temperature range of from Tm + 20 C. to ~ Tm + 100 C., and it appears frequently in the form of a - plurality of peaks in the above-mentioned temperature '', ,;
range The crystal fusion peak (Tp) often appears in the form of two separate peaks, that i5, a higher temperature fusion peak (Tp1) in a temperature range of from Tm +
35 C. to Tm +100 C., and a lower temperature fusion peak (Tp2) in a temperature range of from Tm + 20 C. to Tm +
35 C. Depending upon the conditions of the preparation of the molecularly oriented shaped articles, the Tp1 or TP2 comprises a plurality of peaks.
It is considered that the high crystal fusion peaks (Tp1 and Tp2) prominently improve the heat resi~tance of the molecularly oriented shaped article of the ultrahigh molecular weight ethylene/-~ -olefin copolymer and contribute to maintenance of the strength retention ratio or elastic modulus retention ratio at a high level after a heat hysteresis at an elevated temperature.
It is preferred that the fusion heat ba~ed on the higher temperature fusion peak (Tpl) in a temperature - range of from Tm + 35 C. to Tm + 100 C. be at least . j,.~
1.5%, especially at least 3.0 %, based on the total fusion heat.
In the case where the fusion heat ba~ed on the higher temperature fusion peak (Tp1) satisfies the above requirement, even if the higher temperature fusion peak ' (Tpl) does not apear as a projecting main peak, that is, even if the peak (Tpl) is an assemblage of small peaks or a broad peak, excellent creep resistance characteristics can be obtained though it sometimes happens that the heat resistance is somewhat degraded.
The melting point was measured using a differential scanning calorimeter (Model DSC II supplied by Perkin-Elmer Co.). About 3 mg of a sample was kept in the restraint state by winding the sample on an aluminium :
sheet having a size of 4 mm x 4 mm x 0.2 mm (thickness).
Then, the sample wound on the aluminum sheet was ~ealed in an aluminum pan to be placed in a sample holder of a cell.
An aluminum sheet equal to that used for the sample was sealed in an aluminum pan ordinarily kept vacant, to be placed in a reference holder of the cell, whereby a heat balance was kept. The cell was held at 30 C. for about 1 :j minute, and then, the temperature was elevated to 250 C.
at a rate of 10 C./min. and the measurement of the ::
melting point of the sample at the first temperature elevation was completed. Subsequently, the sample was held at 250 C. for 10 minutes. Then, the temperature was lowered at a rate of 20 C./min. and the sample was held at 30 C. for 10 minutes. Then, the temperature was elevated to 250 C. again at a rate of 10 C./min., and the measurement of the melting point at the xecond 13251~3 temperature elevation (second run) was completed. The maximum value of the fusion peak was designated a~ the melting point. When the peak appeared as a shoulder, tangential lines were drawn at the bending points on the low temperature side and high temperature side ~ust close to the shoulder, and the intersection point was designated as the melting point.
A base line connecting points of 60 C. and 240 C. in the endothermic curve was drawn, and a vertical line was drawn at a point higher by 20 C. than the inherent crystal fusion temperature (Tm) of the copolymer determined as the main fusion peak at the second temperature elevation. A low temperature portion ~urrounded by these lines an area surrounded by the base line, vertical line and endothermic curve including the point of 60 C. was regarded as being based on the inherent crystal fusion (Tm) and the high temperature :
i portion an area surrounded by the base line, vertical line and the endothermic curve including the point of 240 C.was regarded as being based on the crustal fusion (Tp) manifesting the functions of the molecularly oriented shaped article copolymer. The crystal fusion heats were calculated from areas of these portions. According to the above-mentioned method, the portion between vertical lines at Tm + 20 C. and at Tm +35 C. was regarded as being '' 13251~
based on the fusion of TP2 and the high temperature portion was regarded as being based on the fusion of Tpl, and the heata based on the fusion of Tp1, and the heats based on the fusion of Tp1 and the fusion of TP2 were similarly calculated from the areas of these portions.
The molecularly orlented filaments of the above-mentioned ultrahigh molecular weight copolymer of ethylene and at least one alpha-olefin have a strength retention of at least 95 %, and an elastic modulus retention of at least 90 X, in particular at least 95 %, after a heat hysteresis of 170 C., for a period of 5 minutes, indicatlng the fact that they have a prominently superior heat resistance which are not found in drawn filaments of ultrahigh molecular weight polyethylene.
ProceQs for the preparation of a molecularly oriented shaped article of an ultrahlgh molecular weight polyolefin Generally, a molecularly oriented shaped article having high elastic modulus and high strength can be prepared by extrudlng an ultrahlgh molecular weight polyolefin into filaments, tape or the like and ~trongly drawing the exrudate. Such a proces~ per Qe is known in the art.
For examplo, Japane4e Patent ~lrrr~as~-n Lald-Open P~kc~
14 132~1~3 72932-17 Speciflcatlon No. 15408/81 dlscloses a process comprlslng splnnlng a dllute solutlon of ultrahlgh molecular welght polyethylene and drawlng the obtalned fllaments. Japanese Patent Lald-Open Publlcatlon Speclflcatlon No. 130313/84 dlscloses a process com-prlslng melt-kneadlng ultrahlgh molecular welght polyethylene wlth a wax, extruding the kneaded mlxture, coollng and solldlfylng the extrudate and drawlng the solldlfled extrudate. Furthermore, Japanese Patent Lald-Open Publlcatlon Speclflcatlon No. 187614/84 dlscloses a process comprislng extrudlng the abovementloned melt-kneaded mlxture, draftlng the extrudate, then coollng and solldl-fylng the extrudate and drawlng the solldlfled extrudate.
;~ A process for the preparatlon of a molecularly orlented shaped artlcle of a preferred ultrahlgh molecular welght poly-olefln, that ls, an ultrahlgh molecular welght copolymer of ethy-lene and at least one alpha-olefln, wlll now be descrlbed ln detall.
PreParatlon of the CoPolYmer The ultrahlgh molecular welght ethylene/a-olefln copoly-mer ls obtalned, for example, by slurry-polymerlzlng ethylene and at least one a-olefln havlng from 3 to 20, preferably from 4 to 10 carbon atoms ln an organlc solvent ln the presence of a Zlegler ~ catalyst.
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:, . ~ .
i Xi ., ~
13251~3 Examples of the preferred ~(-olefin include, for example, butene-1, pentene-1, 4-methylpentene-1, hexene-1, heptene-l and octene-1. Of these, 4-methyl-pentene-1, hexene-1 and octene-1 are particularly preferred. The~ -olefin comonomer should be used in such an amount that the 1 -olefin content per 1000 carbon atoms in the polymer chain is within the above-mentioned range. Moreover, the ultrahigh molecular weight ethylene/~ -olefin copolymer ,..,'.s should have a molecular weight corresponding to the above-mentioned intrinsic viscosity ] -;.~ (.
In the ultrahigh molecular weight ethylene/~ -olefin copolymer used herein, the determination of the ~ -olefin component is carried out using an infrared - ~pectrophotometer (supplied by Nippon Bunko Kogyo~.
Namely, the ab~orbance at 13~8 cm 1, which indicates the deformation vibration of the methyl group of the ~ -olefin included in the ethylene chain, i~ meaqured, and the measured value is converted to the number of the methyl branche~ per 1000 carbon atoms using a calibration curve prepared in advance using a model compound in a 1 C
- nuclear magnetic resonance spectroscopy.
' Preparation of the molecularly oriented ~ shaped article ':
Upon preparation of the molecularly oriented shaped article of the ultrahigh molecular weight ethylene/
-olefin copolymer, a diluent is incorporated in the copolymer. A solvent for the ultrahigh molecular weight ethylene copolymer or a wax having a compatibility with the ultrahigh molecular weight ethylene copolymer is used as the diluent.
A solvent having a boiling point higher, especially by at least 20 C, than the melting point of the above-mentioned copolymer is preferably used as the solvent.
. As specific examples of the solvent, there can be mentioned aliphatic hydrocarbon solvents such as n-nonane, n-decane, n-undecane, n-dodecane, n-tetradecane, n-octadecane, liquid paraffin and kerosine, aromatic hydrocarbon solvents and hydrogenated products thereof such as xylene, naphthalene, tetralin, butylbenzene, p-cumene, cyclohexylbenzene, diethylbenzene, benzylbenzene, :.
dodecylbenzene, bicylohexyl, decalin, methylnaphthalene and ethylnaphthalene, halogenated hydrocarbon solvents such as 1,1,2,2-tetrachloroethane, pentachloroethane, hexachlorobenzene, 1,2,3-trichloropropane, dichlorobenzene, 1,2,4-trichlorobenzene and bromobenzene, and mineral oils such as paraffinic process oil, naphthenic process oil and aromatic process oil.
132S1~3 Aliphatic hydrocarbon compounds and derivatives thereof can be used as the wax.
A so-called paraffinic wax composed mainly of a saturated aliphatic hydrocarbon compound having a molecular weight lower than 2000, preferably lower than lOoo, especially preferably lower than 800, is mentioned ~,.
as the aliphatic hydrocarbon compound. As speciflc examples of the aliphatic hydrocarbon compound, there can be mentioned n-alkanes having at least 22 carbon atoms, such as docosane, tricosane, tetracosane and triacontane, mixtures comprising an n-alkane as mentioned above as the main component and a lower n-alkane, so-called paraffin waxes and ethylene copolymer waxes, which are low-molecular-weight polymers obtained by homopolymerizing ethylene or copolymerizing ethylene with othero(-olefin, waxes formed by reducing the molecular weight of polyethylene such as medium-pressure, low-pressure or high-pressure poleythylene by thermal degradation, and oxidized waxes and maleic acid-modified waxes obtained by oxidizing the foregoing waxes or modifying the foregoing waxes with maleic acid.
As the aliphatic hydrocarbon compound derivative, there can be mentioned, for example, fatty acids, aliphatic alcohols, fatty acid amides, fatty acid eRters, aliphatic mercaptans, aliphatic aldehydeR and aliphatic 132~14~
ketons having at least 8 carbon atoms, preferably from 12 to 50 carbon atoms, and a molecular weight of from 130 to 2000, preferably from 200 to 800, in which at lea~t one, preferably 1 or 2, especially preferably one functional group such as a carboxyl group, a hydroxyl group, a carbamoyl group, an ester group, a mercapto group or a carbonyl group is contained at the end or in the interior of an aliphatic hydrocarbon group such as an alkyl group or an alkenyl group.
As specific examples, there can be mentioned fatty acids such as capric acid, lauric acid, myristic acid, palmitic acid, stearic acid and oleic acid, aliphatic alcohols such as lauryl alcohol, myristyl alcohol, cetyl alcohol and stearyl alcohol, fatty acid amides such as capric amide, lauric amide, palmitic amide and stearyl amide, and fatty acid esters such as stearyl acetate.
The ultrahigh molecular weight ethylene copolymer/diluent mixing ratio varies depending upon the kind~ of the~e components, but it is generally preferred that this mixing ratio be from 3/97 to 80/20, especially from lS/75 to 60/40. If the amount of the diluent is too small and below the above-mentioned range, the melt viscosity becomes too high and melt kneading or melt shaping is difficult, and surface roughening of the shaped article is conspicuous and breaking is often cau~ed at the '.~' . ~ ~
drawing step. If the amount of the diluent is too large and exceeds the above-mentioned range, melt-kneading becomes difficult and the drawability of the shaped article is insufficient.
It is generally preferred that melt kneading be carried out at a temperature of from 150 to 300 C, especially from 170 to 2~0 C. If melt kneading is carried out at a lower temperature, the melt viscosity is too high and melt shaping becomes difficult. If the temperature is too high and exceeds the above-mentioned range, the molecular weight of the ultrahigh molecular weight ethylene copolymer is reduced by thermal degradation and it becomes difficult to obtain a shaped article having high elastic modulus and high strength.
Mixing can be performed by dry blending using a Henschel mixer or a V-blender or by melt mixing using a single screw or multiple-screw extruder.
Melt shaping of a dope comprising the copolymer and diluent is generally performed by melt extrusion. For example, filaments are obtained by melt extrusion of such a dope through a spinneret. The filaments as extruded through the spinneret may be drafted, that is, Qtretched in the molten state. The draft ratio can be defined by the following formula:
draft ratio - V/Vo .,~
'' 132~143 wherein Vo stands for the extrusion speed of the molten resin in a die orifice, and V stands for the winding speed of the cooled and solidified undrawn filaments.
While the draft ratio depends on the temperature of the mixture and the molecular weight of the ultrahigh molecular weight ethylene copolymer, it may be at least 3, preferably at least 6.
The so-obtained undrawn shaped article of the ultrahigh molecular weight ethylene copolymer is sub~ected to a drawing treatment. Of course, the degree of the drawing treatment is such that molecular orientation in at least one axial direction can be effectively imparted to the copolymer.
It is generally preferred that drawing of the shaped article of the ultrahlgh molecular weight ethylene copolymer be carried out at a temperature of from 40 to 160 C, preferably from 80 to 145 C. Any of air, water steam and liquid media can be used as the heating medium for heating and maintaining the undrawn shaped article at the above-mentioned temperature. If a solvent capable of eluting and removing the above-mentioned diluent, which has a boiling point higher than the melting point of the composltion of the shaped article, for example, decalin, æ
decane, kero~lne or the llke, i5 u~ed a~ the heating .
., medium for the drawing operation, removal of the above-mentioned diluent becomes possible, and drawing unevenness can be eliminated at the drawing step and a high draw ratio can be attained.
Of course, the means for removing the exces~ive diluent from the ultrahigh molecular weight ethylene copolymer i5 not limited to the above-mentioned method.
For example, there may be adopted a method in which the undrawn shaped article is treated with a solvent such as hexane, heptane, hot ethanol, chloroform or benzene and then drawn, and a method in which the drawn shaped article is treated with a solvent such as hexane, heptane, hot ethanol, chloroform or benzene. According to these methods, the exces~ive diluent can be effectively removed and a drawn product having a high elastic modulus and a high strength can be obtained.
The drawing operation may be carried out in one stage or a plurality of stages. The draw ratio dependR on the desired molecular orientation and the resulting improvement of the fusion temperature, but in general, satisfactory reRults are obtained if the drawing operation is carried out at a draw ratio of from 5 to 80, e~pecially from 10 to 50.
In general, drawing in a plurality of stages is advantageous, and there is preferably adopted a method in ~ - 22 -132~143 which at the first stage, the drawing operation is carried out at a relatively low temperature of from 80 to 120 C
while extracting the diluent from the extruded shaped article and at the second and subsequent stages, the operation of drawing is conducted at a temperature of from 120 to 160 C, which is higher than the drawing temperature adopted at the first stage.
Uniaxial drawing of filaments or tape is accomplished by performing the drawing operation between rollers differing in the peripheral speed.
The so-obtained molelcularly oriented ~haped article can be heat-treated under a restraint condition, if de~ired. This heat treatment is carried out at a temperature of from 140 to 170 C, especially from 150 to 175 C, for a period of from l to 20 minute~, especially from 3 to 10 minutes. By this heat treatment, crystallization of the oriented crystalline portion is further advanced, and the crystal fusion temperature is shifted to the high temperature side, the strength and ela~tic modulus are improved and the creep resistance at elevated temperatures is improved.
The rope l for traction accordlng to the invention has a double ~tructure of a core member 2 coated with a sheath member 3, in which the core member 2 compri~es a molecularly oriented shaped article such as filaments and : .
tapes of an ultrahiqh molecular weight copolymer of ethylene and at least one alpha-olefin, and the sheath member 3 comprises a braid. The core member 2 preferably comprises a bundle of aligned drawn filaments of the ultrahigh molecular weight polyolefin, or a braid made thereof. The braid may be made of a single bundle of drawn filaments. Alternatively, a number of bundles of drawn filaments, for example, 3, 4, 6 or 8 bundles of drawn filaments - may be twisted together and then braided to provide the core member 2. Further, the core member may be a parallel lay rope.
- 10 Depending upon the intended use and object of the rope, the diameter of the bundle of drawn filaments and the number of the bundles to be twisted together may be selected.
The core member 2, in the form of a braid, of the rope according to the lnvention preferably has a diameter ranging from 2 to 15 mm and a breaking energy of at least 3 kg.m/g, and ln particular at least 4 kg.m/g. One of the advantages of the molecularly orlented shaped artlcle used herein resides in the fact that braiding reduction in available strength (spinning loss) is low.
The sheath member 3 comprises a braid of yarns of strands of conventional naturally occurrlng or synthetlc fibers.
Examples of usable fibers include, for example, ', ' ` 132~143 polyester fibers, acrylic fibers, cotton, polypropylene fibers, polyethylene fibers, polyamide fibers, rayon (viscose and cupra), linen and Vinylon fibers.
The number of yarns or strands for braiding the sheath member 3 and the thickness of the sheath member 3 may be selected depending upon the intended use of the rope. Normally, the thickness of the sheath member is preferably of the order of form 0.1 to 2 mm.
The rope according to the invention can be prepared by a double braiding method known per se. For example, during or after formation of the core member 2 by aligning or braiding a bundle of bundles of molecularly oriented filaments of an ultrahigh molecular weight polyolefin, the core member is wrapped around helically with inter~ecting yarns of strands so that they may be braided into an enveloping sheath member 3.
. ~
Effect of the Invention The rope for traction according to the invention has a double structure of a core member coated with a sheath member, in which the core member comprlses a light in weight, strong and resilient molecularly oriented ~haped article of an ultrahigh molecular weight polyolefin, and the sheath member comprises a braid, and in con~equence, it is floatable on water and easy to . .
132~1~3 handle, and is excellent in safety to human bodies and weatherability.
Example 1 (Polymerization for Preparation of Ultrahigh Molecular Weight ~thylene/Butene-l Copolymer) Slurry polymerization for forming an ultrahigh molecular weight ethylene/butene-1 copolymer was carried out in 1 Q of n-decane as a polymerization solvent in the presence of a Ziegler catalyst. A monomer mixture gas comprising ethylene and butene-1 at a molar ratio of 9~.2/2.35 was continuously supplied to a reactor so that the pressure inside the reactor iY kept constant at 5 kg/cm2. The slurry polymerization carried out at a ; reaction temperature of ~0C was completed in 2 hours.
: The yield of a powdery ultrahigh molecular weight ethylene/butene-1 copolymer was 160g, an intrinsic : viscosity (at i35 C in decalin) of the copolymer was 8.2dl/g, and the butene-1 content determined by an infraredspectrometer was 1.5 butene-1 molecules per 1000 carbon atoms . IPreparation of Drawn and Oriented product of . Ultrahigh Molecular Weight ~thylene/Butene-l Copolymer) A mixture comprising 20 parts by weight of the powdery ultrahigh molecular weight ethylene/butene-1 copolymer obtained by the above-mentioned polymerization and 80 parts by weight of a paraffin wax (melting point = 69C, molecular weight = 490) was melt-spun under the following conditions.
To 100 parts by weight of the above-mentioned filament mlxture was added 0.1 part by weight of 3,5-di-tert-butyl-4-hydroxy-toluene as a process stabilizer. The mixture was then melt-kneaded at a set temperature of 190 C., using a screw type extruder (screw diameter = 25 mm, L/D = 25, manufactured and sold by Thermoplastics Co.).
Subsequently, the molten mixture was melt spun through a spinning die having an orifice diameter of 2 mm, ~
splnnlng die being attached to the extruder. The extruded melt was taken at a draft ratio of 36 times with an air gap of 180 cm, cooled and solidlfied in the air to provide an undrawn filament. The undrawn filament was then drawn under the following conditions.
Two-staged drawing wa carried out using three godet rolls. A heating medium employed in a first drawing tank wa~ n-decane and the temperature wa~ 110C, and a heating mediu~ employed in a ~econd drawing tank was triethylene glycol and the temperature was 145C. The effectlve length of each tank was 50 cm. The undrawn filament was drawn with a first godet roll operated at a 2~t - 2~ --~ 132~1~3 rotation speed of 0.5 m/min while adjusting a rotation speed of a third godet roll to provide an oriented filament of a desired draw ratio. A rotation speed of a second godet roll was suitably selected so that a stable drawing operation is made possible. Substantially all of the paraffin wax initially added was extracted ~n n-decane from the filament at a stage in which it is drawn. The oriented filament was then washed with water and dried a whole day and night at room temperature and under reduced pressure, followed by determination of physical properties thereof. Incidentally, the draw ratio was calculated from the ratio of the rotation speed between the first and third godet rolls.
(Measurement of Tensile Characteristics) The oriented filament was tested for its elastic modulus and tensile strength at room temperature (23C) using a tensile tester (Model DCS-50M manufactured and sold by Shimadzu Seisakusho). The sample was a bundle of 100 filaments each having a thickness of 10 denier.
In that case, a sample length employed between clamps was 100 mm, and a rate of pulling employed was lOOmm/min (a rate of strain of 100%/min). The elaRtic modulus was an initial elastic modulus calculated from a tangential gradient of the stress-strain curve. A
sectional area necessary for the calculation was obtained 13251~.~
by calculation from a weight of the sample, assuming the density of the sample as 0.960g/cc.
(Tensile Elastic Modulus Retension and Strength Retention after Heat Hysteresis) A heat hysteresis test was carried out by allowing a sample to stand still in a gear oven ~Perfect Oven manufactured and sold by Tabai Seisakusho).
;" The sample having a length of about 3 m was wound repeatedly on a stainless steel frame having a plurality of blocks attached to both ends thereof, and both ends of the ~ample were fixed. In that case, both ends of the sample were fixed to such an extent that the sample does not ~ag, and no positive tension was imposed on the sample. Tensile characteristics of the sample after the heat hysteresis test were determined according to the procedure as described in the aforementioned measurement of tensile characteristics.
; (Measurement of Creep Resistance) The drawn and oriented filament was tested for its creep resistance using a thermal stress distortion measurement apparatus (Model TMA/SS10 manufactured and sold by Seiko Denshi Kogyo), wherein the sample length was 1 cm, ambient temperature was 70C, and mea~urement was ;~ conducted under an accelerated condition by applying to the sample a load corresponding to 30 % of a breaking load `:
- 2~ -at room temperature. In order to evaluate a creep quantltatively, the following two values were determined, That i~, there were determlned values of a creep elongation CRgo~X) at the time 90 seconds after application of the load, and of an average creep speed ., --1 (sec ) between the time 90 second~ after application of the load and the time lB0 seconds after the above-mentioned time.
: Tensile characteristics of the bundle of drawn and oriented filaments are shown ln Table 1.
~; Table 1 Sample Filament Draw Strength Elastic Elon- Degree of denier/ ratiomo~ulu~ gation orien-filaments tation (GPa) ~GPa) (%) ~F) ....~
Sample 1000/ 22.3 2.4 60 5.50 0.975 The lnherent crystal fuslon peak of the drawn and oriented fllament (~ample-l) of the ultrahigh molecular welght ethylene/butene-1 copolymer appeared at 126.~C, and the proportion of fusion peak based on Tp to the total - crystal fusion heat wa4 33.8X. The creep reslstance ~ i .
' ~., characteristics were such that CRgo was 3.1% and was 3.03 X 10 5 sec 1 After the heat hysteresis at 170C for 5 minutes, the elastic modulus retention ratio was 102.2%, and the strength retention ratio was 102.5%, showing no decrease in performance of the drawn and oriented filament.
Furthermore, physical properties of this drawn and oriented filaments were such that the amount of work necessary for rupture of the filament was 10.3 kg~m/g, the density was 0.973 g/cm3, the dielectric constant was 2.2, the dissipation loss tangent was 0.024%, and the impulse breakdown voltage was 180KV/mm.
A traction rope according to the present invention, which comprises the following core and sheath members was prepared.
Core member:
~ n eight bundle plaited rope having a thickness of 12,000 denier made of ultrahigh molecular weight ethylene/butene-1 copolymer filaments (sample-1).
Sheath member:
A sheath member was obtained by plaiting polye~ter spun yarns each having a thickness of 1,000.
Morphological and physical properties of the rope thus prepared are shown in Table 2.
Table 2 __ I
Sampl~ Core Wall Unit Breaking Breaking Amount of energy diameter thickness weight strength elongation required for bringing of sheath about breakage (mm) (mm) (g/m) (Ton) (%) (kg m/g) ___ . __ ___ - Sampl l -lA 4.0 0.5 12 2.0 6.5 5.40 __ __ _ _ Example 2 (Polymerization for Preparation of Ultrahigh Molecular Weight Ethylene/Octene-1 Copolymer) Slurry polymerization of ethylen was carried out in the presence of a Z~egler catalyst in 1 Q of n-decane as a polymerization solvent. In that case, 125 ml of octene-1 as a comonomer and 40 Nml of hydrogen as a molecular weight-adjusting agent were collectively added, prior to the intiation of the polymerization, to the system, and the polymerization was then allowed to proceed. Ethylene gas was continuously supplied to a reactor so that the pressure inside the reactor is kept constant at 5kg/cm2 and the polymerization was completed in 2 hours at 70C. The yield of powdery ultrahigh molecular weight ethylene/octene-l copolymer obtained was ....
132~143 178g, the Intrlnsic viscosity ~] ~at 135 C in decalin) was 10.66dl/g, and the octene-1 content as determined by an infrared spectrophotometer was 0.5 octene-1 molecule per 1000 carbon atmos.
(Preparation and Physical properties of Drawn and Oriented product of Ultrahigh molecular weight ~thylene/Octene-l Copolymer) Drawn and oriented filaments were prepard from the ethylene/octene-1 copolymer thus obtained in the sa~e manner as described in ~xample 1. Tensile characteristics of a bundle of the drawn and oriented filaments obtained are shown in Table 3.
Table 3 Samplt Filament Draw Strength elastic ~lon- Degree of V Denler/ ratlo mo~ul ~ gation orien-Fllaments tation (GPa) (GPa)(X) (F) Sampl~ 1000/ 16.02.3 65 5.40 0.978 .' ..
':
The inherent crystal fuslon peak of the drawn and - orlented filanenta (sample-2) of the ultrahigh molecular : ~, ..r .
. ~:
. , ~ ~ .
weight ethylene/octene-1 copolymer appeared at 132.1 C, and proportions of fusion heat based on Tp and Tp1 to the total crystal fusion heat were 9~.~% and 5.0%, respectively. The creep resistance characteristics of the sample-2 were such that CRgo was 2.0% and ~ was 9.50 X 10 sec 1. After heat hysteresis at 170C for 5 minutes, the ela~tic modulus retention was 108.2% and the strength retention was 102.1%. Furthermore, physical properties of the sample-2 were such that the amount of work necessary for rupture of the filament was lO.lRg m/g, the density was 0.971g/cm3, the dielectric constant was 2.2, the dissipation losq tangent was 0.031%, and the impulse breakdown voltage was 185KV/mm.
A traction rope according to the present invention was obtained in the same manner as descri~ed in ~xample 1 using the drawn and oriented filaments (sample-2) of the ultrahigh molecular weight ethylene/octene-1 copolymer thus obtained. Morphological and physical properties of the rope obtained are shown in Table 4.
' Table 4 __ _ . _ _ Sample Core Wall Unit Breaking Breaking Amount of energy diameter thicknesq weight strength elongation required for bringing of sheath about breakage ~mm) ~mm) ~g/m) (Ton) (~) (kg~m/g) _ ;ample -2A 4.0 0.5 12 2.0 6.3 5.20 Example 3 A powdery mixture comprising 20 parts by weight of `; a ultrahigh molecular weight polyethylen(homopolymer) having an intrinsic viscosity of t~]=7.42 dl/g as measured at 135C in decalin and 80 parts by weight of a parrafin wax having a melting point of 69C and a molecular weight of 490 was melt-spun and drawn in the same manner as described in Example 1 to obtain a drawn and oriented filament. Tensile characteristics of a bundle of the drawn and oriented filaments thus obtained are shown in " Table 5.
';
.
132~143 Table 5 .
Sample Filament Draw Strength Elastic ~lon- Degree of denler/ ratio modulu~ gation orien-filaments tatlon (GPa)(GPa) (X) (F) Sampl~ lOOOt 23.12.590 4.10 0.9B0 The inherent crystal fusion peak of the drawn and oriented filaments (sample-3) of the ultrahigh molecular - wel~ht poly~thylene wa~ 136.1C, and a proportion of fusion heat based on Tp to the total crystal fusion heat was 8.8X. Whereas, a proportion of fusion heat based on Tp1 on the higher temperature side to the total cry~tal fusion heat wais less than lX. The creep resistance characteristics were such that CRgo was ll.9X and ~ wa~
1.07 X 10 3 sec 1. After heat hysteresis at 170C for 5 minutes, the elastic modulus retention was 80.4% and the strength retention was 78.2X. Furthermore, physical properties of the sample-3 were such that the amount of work neces~ary for rupture of the filament was 10.2Kg m/g, the density was 0.985g~cm3, the dielectric constant was 2.3, the diasipation loss tangent was 0.030%, and the "~ .
,' '.: i .
'.
.' - 36 ~
impulse breakdown voltage was lB2KV/mm.
A traction rope of the present invention was obtained in the same manner as described in ~xample 1 using the drawn and oriented filaments (sample-3) of the ultrahlgh molecular weight polyethylene. Morphological and physical properties of the rope obtained are shown in Table 6. Table 6 Sampl~ Core Wall Unit Breaking ~reaking Amount of energy dlameter thlcknesa welght strength elongation required for bringin of sheath about rapture ~mm)~mm) (g/m) tTon) (%) ~g-m/g) . _ Sampl~
- -3A 4.00.5 13 1.9 4.7 3.51 , .
Comparative ~xample 1 A traction rope was prepared using a400 denier drawn filaments of Kebleri~29 ~aramid fiber produced by Du Pont) as a core in place of the core member described in ~xample 1. Morphological and physlcal properties of the rope thu~ obtalned are shown ln Table ~.
a~
' '':`
. -37-Table 7 Sample Core Wall Unit Breaking Breaking Amount of energy diameter thicknes~ weight strength elongation required for bringing of sheath about rapture (mm) (mm)~g/m) (Ton) (%) (kg m/g) ___ Sampl~
-4A 3 8 0.5 12 1.9 3.6 2.80 ~".
;
;
Claims (13)
1. A rope for traction of a double structure comprising core member coated with a sheath member, in which the core member comprises a molecularly oriented shaped article made of an ultrahigh molecular weight copolymer of ethylene and at least one alpha-olefin having from 3 to 20 carbon atoms, wherein the copolymer contains from 0.1 to 20 moles of the copolymerized alpha-olefin on average per 1000 carbon atoms of the copolymer and has an intrinsic viscosity of at least 5 dl/g, and the sheath member comprises a braid.
2. The rope for traction according to claim 1, wherein the molecularly oriented shaped article constituting the core member comprises a bundle of aligned drawn filaments of the ultrahigh molecular weight copolymer.
3. The rope for traction according to claim 1, wherein the molecularly oriented shaped article constituting the core member comprises a braid of drawn filaments of the ultrahigh molecular weight copolymer.
4. The rope for traction according to claim 1, wherein the sheath member comprises a braid of spun yarns.
5. The rope for traction according to claim 1, 2, 3 or 4, wherein the copolymer has an intrinsic viscosity of 7 to 30 dl/g.
6. The rope for traction according to claim 5, wherein the copolymer is ethylene/butene-1 copolymer or ethylene/octene-1 copolymer.
7. A rope for traction, the said rope being floatable on water and having a double structure comprising a core member coated with a sheath member, in which the core member comprises molecularly oriented filaments or a braid thereof, the filaments being made of an ultrahigh molecular weight copolymer of ethylene and a C4-10 alpha-olefin that has an intrinsic viscosity [?] of 5 to 30 dl/g and contains 0.5 to 10 moles of the copolymerized alpha-olefin on average per 1000 carbon atoms of the copolymer, and the sheath member comprises a braid of yarns or strands of natural or synthetic fibers.
8. The rope according to claim 7, wherein the ultrahigh molecular weight copolymer is a copolymer of ethylene and an alpha-olefin selected from the group consisting of 1-butene, 4-methyl-1-pentene, 1-hexene, 1-octene and 1-decene.
9. The rope according to claim 8, wherein the filaments or tapes are prepared by extruding the copolymer into filaments or tapes and then drawing at a draw ratio of 10 to 50; have a density of from 0.940 to 0.990; a dielectric constant (1KHz, 23°C) of from 1.4 to 3.0; a dielectric loss tangent (1KHz, 80°C) of from 0.050 to 0.008%; and a degree of molecular orientation (F) of at least 0.90.
10. The rope according to claim 9, wherein the filaments or tapes has an elastic modulus of at least 20 GPa, a tensile strength of at least 1.2 GPa, an impulse break down voltage of 110 to 250 KV/mm, a breaking energy of at least 8 kg.m/g and a creep elongation (% elongation after 90 sec.) of not more than 7% when measured at a temperature of 70°C with a load of 30% of the breaking load.
11. The rope according to claim 10, wherein the filaments or tapes has at least one crystal fusion peak (Tp) at a temperature that is 20 to 100°C higher than an inherent crystal fusion temperature (Tm) of the copolymer.
12. The rope according to any one of claims 1 to 4 or any one of claims 7 to 11, which is adapted for traction of a paraglider.
13. The rope according to any one of claims 1 to 4 or any one of claims 7 to 11, which is adapted for traction of a waterski.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP225652/1987 | 1987-09-08 | ||
| JP22565287 | 1987-09-08 | ||
| JP82502/1988 | 1988-04-04 | ||
| JP63082502A JP2557459B2 (en) | 1987-09-08 | 1988-04-04 | Tow rope |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1325143C true CA1325143C (en) | 1993-12-14 |
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ID=26423514
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000576525A Expired - Fee Related CA1325143C (en) | 1987-09-08 | 1988-09-06 | Rope for traction |
Country Status (6)
| Country | Link |
|---|---|
| EP (1) | EP0318136B1 (en) |
| JP (1) | JP2557459B2 (en) |
| KR (1) | KR900006037B1 (en) |
| CN (1) | CN1016372B (en) |
| CA (1) | CA1325143C (en) |
| DE (1) | DE3886012T2 (en) |
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| CN1091191C (en) * | 1999-06-30 | 2002-09-18 | 林淮尧 | Stand-by stressed steel cable |
| CN100560428C (en) | 2004-12-23 | 2009-11-18 | 帝斯曼知识产权资产管理有限公司 | Air cargo net |
| CN100376744C (en) * | 2006-01-26 | 2008-03-26 | 中国科学院安徽光学精密机械研究所 | Weaving method for captive balloon cable of polyethylene fiber with ultra-high molecular weight |
| EP1870281A1 (en) | 2006-06-23 | 2007-12-26 | DSMIP Assets B.V. | Cargo net |
| CA2741296A1 (en) * | 2008-10-23 | 2010-04-29 | Polteco Inc. | Abrasion resistant cords and ropes |
| DE102009040964A1 (en) * | 2009-09-11 | 2011-03-24 | Sgl Carbon Se | rope |
| JP5639542B2 (en) * | 2011-07-11 | 2014-12-10 | 高木綱業株式会社 | rope |
| CN104024518B (en) * | 2011-11-02 | 2016-08-24 | 帝人芳纶有限公司 | There is the polyethylene rope of high intensity-strength ratio |
| CN102493237A (en) * | 2011-12-23 | 2012-06-13 | 建峰索具有限公司 | High polymer polyethylene fiber tubular sling and manufacturing method thereof |
| AU2013393268B2 (en) * | 2013-06-20 | 2017-04-13 | Zhengzhou Zhongyuan Defense Material Co., Ltd | High-strength rigging and preparation method thereof |
| NL2011303C2 (en) * | 2013-08-14 | 2015-02-19 | Lely Patent Nv | WEAR RESISTANT FEEDING BOOK. |
| CN103469651B (en) * | 2013-08-29 | 2017-09-08 | 山东鲁普科技有限公司 | A kind of waterproof acid-fast alkali-proof cordage and preparation method thereof |
| JP6465595B2 (en) * | 2014-09-04 | 2019-02-06 | 芦森工業株式会社 | Method for manufacturing water levitation rope |
| KR102165927B1 (en) * | 2020-04-08 | 2020-10-14 | 대한민국 | Life-saving buoyancy rope and life-saving structure body using the same |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3078755A (en) * | 1961-01-27 | 1963-02-26 | Samson Cordage Works | Braided cordage |
| DE7423933U (en) * | 1974-07-13 | 1974-10-24 | Hoechst Ag | |
| JPS5358071A (en) * | 1976-10-30 | 1978-05-25 | Nitto Kasei Co Ltd | Net and rope for preventing contamination under water |
| NL177759B (en) * | 1979-06-27 | 1985-06-17 | Stamicarbon | METHOD OF MANUFACTURING A POLYTHYTHREAD, AND POLYTHYTHREAD THEREFORE OBTAINED |
| EP0115192B2 (en) * | 1982-12-28 | 1992-07-22 | Mitsui Petrochemical Industries, Ltd. | Process for producing stretched filaments of ultrahigh-molecular-weight polyethylene |
| FR2576045B1 (en) * | 1984-12-20 | 1987-04-30 | Cousin Freres Sa | CORD BRAIDED CORD AND METHOD FOR MANUFACTURING SUCH CORD |
| JPH06102846B2 (en) * | 1985-05-01 | 1994-12-14 | 三井石油化学工業株式会社 | Method for producing ultra-high molecular weight polyethylene stretched product |
| JPS62126398U (en) * | 1986-02-03 | 1987-08-11 | ||
| JPH0248477Y2 (en) * | 1986-02-07 | 1990-12-19 |
-
1988
- 1988-04-04 JP JP63082502A patent/JP2557459B2/en not_active Expired - Fee Related
- 1988-09-06 CA CA000576525A patent/CA1325143C/en not_active Expired - Fee Related
- 1988-09-07 CN CN88106629A patent/CN1016372B/en not_active Expired
- 1988-09-08 KR KR1019880011593A patent/KR900006037B1/en not_active IP Right Cessation
- 1988-09-20 EP EP88308707A patent/EP0318136B1/en not_active Expired - Lifetime
- 1988-09-20 DE DE88308707T patent/DE3886012T2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| CN1016372B (en) | 1992-04-22 |
| EP0318136A3 (en) | 1989-08-09 |
| EP0318136B1 (en) | 1993-12-01 |
| KR890005345A (en) | 1989-05-13 |
| DE3886012T2 (en) | 1994-03-31 |
| EP0318136A2 (en) | 1989-05-31 |
| CN1032048A (en) | 1989-03-29 |
| DE3886012D1 (en) | 1994-01-13 |
| JPH01162884A (en) | 1989-06-27 |
| JP2557459B2 (en) | 1996-11-27 |
| KR900006037B1 (en) | 1990-08-20 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKLA | Lapsed |