JPS59187614A - Drawn polyethylene material having ultrahigh molecular weight - Google Patents

Abstract

PURPOSE:To obtain easily the titled drawn polyethylene material having a high elasticity and tensile strength, by melt extruding polyethylene (PE) having an ultrahigh molecular weight and a specific intrinsic viscosity and a low-melting paraffinic wax, drafting the extrudate, solidifying the drafted extrudate under cooling, and drawing the solidified extrudate under specific conditions. CONSTITUTION:A drawn polyethylene material, having an ultrahigh molecular weight, and obtained by melt kneading a mixture of (A) 15-80pts.wt. polyethylene having an ultrrahigh molecular weight and >=5dl/g intrinsic viscosity with (B) 85-20pts.wt. paraffinic wax having 40-120 deg.C melting point and <=2,000 mol.wt. at 190-280 deg.C temperature in a screw extruder, extruding the resultant kneaded mixture through a die at 210-300 deg.C, drafting the resultant undrawn extrudate at least >1 drafting ratio, solidifying the drafted extrudate under cooling, and drawing the solidified extrudate at least >3 drawing ratio.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is based on the melt extrusion method of ultra-high molecular weight polyethylene. The present invention relates to a method for producing a stretched ultra-high molecular weight polyethylene product having high tensile strength and elastic modulus by melt-extruding and stretching a composition comprising a paraffin wax.

Ultra-high molecular weight polyethylene has superior impact resistance, abrasion resistance, chemical resistance, tensile strength, etc. compared to general-purpose polyethylene.
Its use as an engineering plastic is expanding. ■, 5 However, compared to general-purpose polyethylene, the melt viscosity is extremely high and the fluidity is poor, so it is molded by extrusion molding or injection molding.
, <, Are most of them compression molded?・Currently, some of the rods and the like were extruded at extremely low speeds.

・-・15, & A method for stretching monofilaments of dense polyethylene at high magnification and 1. ′τ, :a-: I
A high boiling point additive with a high boiling point of J 5'-(1,000 yen corner point) is allowed to coexist on top of polyethylene in a range of 1,20-150%, and from the resulting high-concentration dispersion, the The primary fibrous material is formed υ, then 5゛ into the second spun yarn +7) 5-
・Remaining an amount equivalent to 25% of the additive, 14 metama-r 5...-15 times the original length (this method of hot stretching (Tokuko Sho 3)
7-9765) or by spinning a solution of linear polyethylene with a molecular weight of 400,000 or more to obtain at least 2Q
A method of stretching at a temperature of GPa has been proposed. However, these methods specifically involve dispersing or dissolving in a solvent such as 0-dichlorobenzene, xylene, or decalin and spinning using a specific method, and continuous extrusion spinning using a screw extruder. Even if an attempt was made to use such a liquid solvent as a stretchability improver for ultra-high molecular weight polyethylene with a high molecular weight, the difference in viscosity between the solvent and the powder was too large, making it impossible to mix the solvent and the powder at all. In addition, the solvent acts as a lubricant between the powder and the screw, causing the powder and screw to rotate together, making extrusion almost impossible. Further, even if it could be extruded, it would be completely impossible to draw it because it was not mixed uniformly, and it was currently impossible to perform continuous melt extrusion spinning using a screw extruder. Furthermore, since these solvents have low boiling points and large σ1 values, they are dangerous to use in screw extruders that heat with electric heat, and special care must be taken when using them.

On the other hand, in order to improve the moldability of ultra-high molecular weight polyethylene, 10 parts by weight of low molecular weight polyethylene with a molecular weight of 5,000 to 20,000 is added to 100 parts by weight of ultra-high molecular weight polyethylene.
~60 parts by weight of the composition (Japanese Patent Application Laid-open No. 57-1770)
However, in these compositions, the molecular weight of the added low molecular weight polyethylene is too large, making it impossible to draw the melt extrusion spun monofilament to a high magnification of 20 times or more, resulting in a high elastic modulus. , it is not possible to obtain monofilaments with high tensile strength.

From this point of view, the present inventors conducted various studies aimed at developing a continuous extrusion molding method for drawn products of ultra-high molecular weight polyethylene having high elastic modulus and high tensile strength using a screw extruder, and as a result, they identified ultra-high molecular weight polyethylene. The object of the present invention was achieved by using a composition containing paraffin wax, and the present invention was completed.

That is, in the present invention, the intrinsic viscosity [η] is at least 5 dJ.
l? Ultra-high molecular weight polyethylene (→: 15 to 80 parts by weight of /g or more) and paraffin wax (B) with a melting point of 40 to 120°C and a molecular weight of 2000 or less (B): 85
and 20 parts by weight at 190 to 280°C.
The unstretched material is melt-kneaded in a screw extruder at a temperature of
We propose a method for producing a drawn ultra-high molecular weight polyethylene product with a high elastic modulus, which is characterized by applying a draft exceeding 100°C, solidifying it by cooling, and then drawing it at a temperature of 60 to 140°C with a drawing ratio of at least 3 times. 〇 Ultra-high molecular weight polyethylene used in the method of the present invention.
/g range. If [η] is less than 5 dβ/g, a stretched product with excellent tensile strength cannot be obtained even if stretched. Also, the upper limit of [η] is not particularly limited, but is 30 d
l/g wo! What you can get is paraffin wax (described below).
Even if B) is added, the melt viscosity is high and the melt spinnability with a screw extruder in the temperature range described below is poor.

The paraffin wax (B) used in the method of the present invention has a melting point of 40 to 120°C, preferably 45 to 110°C, and a molecular weight of 2000 or less, preferably 1
000 or less, particularly preferably 800 or less. If a material with a melting point of less than 40°C or liquid paraffin is used, ultra-high molecular weight polyethylene (the chrysanthemum and the screw will rotate together and uniform melt spinning will not be possible.On the other hand, if a material with a melting point of less than 120°C and a molecular weight of
If it exceeds 00, drafting before cooling and solidification will cause stretching breakage, making it impossible to obtain a drawn product with high elastic modulus and high σ[tensile strength. It cannot be extracted either. In addition, when using a material with a molecular weight of 800 or less, by applying a trough before cooling and solidifying, a drawn product with a sufficiently high elastic modulus can be obtained even at a drawing ratio of more than 5 times.

When a paraffin wax having a molecular weight of 800 to 2000 is used, it is preferable to apply a draft and stretch the wax at a stretching ratio of 5 times, preferably 10 times or more, before cooling and solidifying it.

The melting point in the present invention is a value measured by a differential scanning calorimeter (DSC) according to ASTM D 3417 [7]. Moreover, the molecular weight is the weight average molecular weight (stone W) obtained by measuring by GPC method (gel permeation chromatography) under the following conditions.

Equipment: Waters Co., Ltd. 150C type column: Toyo Soda Co., Ltd. TSK, GMH-6 (6 mmφ x 600 m
m) Solvent: Orthodichlorobenzene (oDeB) Temperature:
135°C Flow rate: 1. Omd/min Injection concentration: 30mg/20ml 0DCB (Injection amount 400tG In addition, manufactured by Toyo Soda Co., Ltd. and Pressure Chemical Company,
Column elution volumes were calibrated by the universal method using standard polyethylene.

The paraffin wax (B) used in the method of the present invention is not particularly limited to a compound consisting only of carbon and hydrogen, as long as it has a melting point and molecular weight within the above range, and may contain a small amount of oxygen or other elements. You can stay there.

The paraffinic wax CB) is mainly composed of saturated aliphatic hydrocarbon compounds, specifically, n-alkanes having 22 or more carbon atoms such as tocosan, tricosane, tetracosane, triacontane, etc., or those containing these as main components. so-called paraffin wax separated and purified from petroleum, medium/low pressure polyethylene wax which is a low molecular weight polymer obtained by copolymerizing ethylene or ethylene with other α-olefins. , high-pressure polyethylene wax, ethylene copolymer wax, medium/low-pressure polyethylene, high-pressure polyethylene, wax whose molecular weight has been lowered by thermal degradation, etc., and fermentation of oxides or maleic acid modified products of these waxes. Examples include wax, maleic acid-modified wax, and the like.

Other hydrocarbon compounds that fall within the melting point and molecular weight range of the paraffinic wax CB) used in the present invention include aromatic hydrocarbon compounds such as naphthalene and dimethylnaphthalene, but unlike paraffinic wax, these compounds have ultrahigh The compatibility with molecular weight polyethylene (A) is poor, and when used in the method of the present invention, ultra-high molecular weight polyethylene (A)
), resulting in uneven dispersion of aromatic hydrocarbons in the film, making it impossible to achieve uniform stretching or a high stretching ratio.

Ultra-high molecular weight polyethylene (shu and paraffin wax)
A specific example of a method for examining the compatibility with B) and the like is a method of observing a cross section of an undrawn yarn using a high-magnification scanning electron microscope. That is, ultra-high molecular weight polyethylene (A)
and paraffin wax (B), etc. in equal amounts are melt-kneaded and then melt-spun. Next, the obtained undrawn yarn is cut with a sharp blade such as a micro F-cut so as to be perpendicular to its longitudinal direction.

A cross section cut out by the same treatment as the cross section was further soaked in a non-polar solvent such as hexadi or hebutane for at least 1 hour.
Paraffin wax (B) after soaking at room temperature for more than an hour.
The extracted cross-section from which these substances have been extracted and removed is comparatively observed using a scanning electron microscope at a magnification of at least 3000 times or more. The paraffin wax (F() of the present invention has good compatibility with ultra-high molecular weight polyethylene (Sugi J), so it has 0Att
Almost no depression was observed, and paraffin wax (B
) If naphthalene is used instead of 20%, poor dispersion occurs and numerous depressions of 0.1 μm or more are observed.

The method of the present invention includes the ultra-high molecular weight polyethylene (A): 1
5 to 80 parts by weight, preferably 30 to 50 parts by weight, and the paraffin wax (B): 85 to 2 parts by weight.
j
Melt and knead with a screw extruder at a temperature of 250℃ 2
10 to 300'C, preferably 210 to 270
The unstretched material is extruded through a die at 60°C, preferably 2 or more drafts, then cooled and solidified, and then heated at a temperature of 60 to 140°C, preferably 100 to 135°C, at least 3 times This is a method of stretching at a stretching ratio of 5 times or more.

If the amount of ultra-high molecular weight polyethylene (A) is less than 15 parts by weight, it will be difficult to melt-knead it in a screw extruder, and the extruded product will have poor stretchability, breakage will occur, and drafting will not be possible. On the other hand, if it exceeds 80 parts by weight, the melt viscosity becomes high, making melt extrusion difficult, and the extruded unstretched product (strand) has a rough surface and is prone to stretching breakage.

The temperature of the screw extruder and Gui is 190°C each.
and below 210°C, the melt viscosity is high and melt extrusion is difficult, while above 280°C and 300°C, respectively, the molecular weight of the ultra-high molecular weight polyethylene (A) decreases, resulting in a drawn product with high tensile strength. is not obtained. In addition, ultra-high molecular weight polyethylene (broadcast) and paraffin wax (B) are mixed using a Henschel mixer, ■-blender, etc.
Alternatively, after mixing, the mixture may be further melt-kneaded and granulated using a single-screw or multi-screw extruder.

When an undrawn material is extruded from a gooey, by applying a draft of at least 1 or more before the molten material is cooled and solidified, a drawn material with a higher elastic modulus and higher tensile strength than a drawn material without drafting can be obtained. is obtained.

The term "draft" in the present invention refers to the drawing of the melt extruded from the screw extruder during melting, and refers to the drawing down of the melt. That is, the draft ratio was defined as the ratio of the Gouy-Oriais diameter to the diameter of the cooled and solidified fibers.

Further, the cooling may be performed by either air cooling or water cooling.

If the temperature during stretching is less than 60°C, a stretching ratio of more than 6 times cannot be achieved, while if it exceeds 140"C, the ultra-high molecular weight polyethylene (A) will soften and although it will be stretched, it will not be possible to achieve a stretching ratio of more than 6 times. I can't get things.

If the above-mentioned stretching is carried out in an atmosphere within the range of 60 to 140°C, a stretched product with a high elastic modulus can be obtained using air, water vapor, or a solvent as the heating medium. A solvent that can elute or exude B) and has a boiling point of 140°C or higher, specifically, for example, decalin, decane, or kerosene, can be used to extract or exude excess paraffin wax (B) during stretching. This is preferable because it is possible to remove the above, reduce stretching unevenness during stretching, and achieve a high stretching ratio. In addition, methods for removing excess paraffin wax (B) from a stretched product of ultra-high molecular weight polyethylene (A) are not limited to the above-mentioned method, but include a method in which an unstretched product is treated with a solvent such as hexane or heptane, and then stretched. Paraffin wax CB)
can be extracted and removed, and a drawn product with high elastic modulus and high strength can be obtained.

When extracting paraffin wax (B) with the above solvent or solvent, paraffin wax C in the stretched product
When the remaining amount of B) is 10% by weight or less, microporous fibers can be obtained, and both the elastic modulus and strength obtained from the method of determining the true cross-sectional area in terms of weight do not fall below the values of the stretched product before extraction, which is preferable. .

When the stretching ratio in the solvent is less than 3 times, the degree of high tensile strength and high elastic modulus is small, and the stretched product is accompanied by uneven stretching, which often impairs the appearance. The stretching may be carried out in a final stretching ratio of 6 times or more, and may be carried out in one stage or in multiple stages of two or more stages.

Further, the final stretching speed during stretching is not particularly limited, but from the viewpoint of productivity it is 3 m/min or more, preferably 5 m/min.
It is better to have n or more.

The ultra-high molecular weight polyethylene (A) used in the present invention contains additives that can be normally added to polyolefins, such as heat stabilizers, weather stabilizers, pigments, dyes, and inorganic fillers, within a range that does not impair the purpose of the present invention. It may be added in advance.

The drawn product of ultra-high molecular weight polyethylene obtained by the method of the present invention has high tensile strength and high elastic modulus that cannot be obtained with conventional drawn products of ordinary polyethylene. In addition to the field of drawn yarn, it can be used in the field of high modulus and high strength fibers.
Can be used for various reinforcing materials that require lightness. Furthermore, it is suitable for functional materials such as selective membranes and electrets that utilize the highly aligned crystal arrangement achieved by ultra-high stretching and the micropores that are generated as a by-product by extracting excess paraffin wax (B). is also excellent.

Next, the present invention will be explained in more detail with reference to Examples.
The invention is not limited to these embodiments unless it goes beyond the gist of the invention.

Example Ultra-high molecular weight polyethylene ([η) -8,20d//g
) and paraffin wax (melting point = 69°01 molecular weight = 4
60) was melt-spun and drawn under the following conditions. After mixing ultra-high molecular weight polyethylene powder and crushed paraffin wax,
Using a screw extruder with L/D=20, the resin temperature was 190.
Melt kneading was carried out at °C. Next, the melt was extruded through a die with an orifice diameter of j mm, and an air gap of 10
Solidified with cold water at 20°C.

At this time, the fibers were skimmed so that the diameter of the cooled and solidified fibers was 0 to 50 mm. That is, the draft ratio was set to 2. Subsequently, using a pair of godet rolls, a drawing tank was drawn using n-decane as a heating medium (temperature inside the tank = 130°C, length of 1 tank =
40z).

During stretching, the rotational speed of the first godet roll was set to 0.
5 m/m1-n, and by appropriately changing the rotational speed of the second godet roll, fibers with different drawing ratios were obtained.

However, the stretching ratio was calculated from the rotation ratio of the godet roll. Table 1 shows the elastic modulus and strength at each stretching ratio. It can be seen from Table 1 that a stretched product with high strength can be obtained when the stretching ratio is 10 times or more. The elastic modulus and strength were measured at room temperature (23°C) using an Instron universal testing machine model 1123 (manufactured by Instron). At this time, the sample length between the clamps is 100 mm and the tensile speed is 1 Q 0 mm.
It was set to 7 minutes. However, the elastic modulus was calculated using stress at 2% strain. The fiber cross-sectional area required for calculation is as follows: The density of polyethylene is Q, 96 g/cm', and the weight and length of the fiber Example: Ultra-high molecular weight polyethylene ([η) = 8.20 al
/g) and paraffin wax (melting point = 69°C, molecular weight = 460) was melt-spun and stretched under the same conditions as in Experimental Example 1. However, the melt was extruded through a die with an orifice diameter of 1 mm and solidified with cold water at 20° C. with an air gap of 10 crn. At this time, the fibers were drawn down so that the diameter of the cooled and solidified fibers was 0.20 mm. That is, the draft ratio was set to 5. Table 2 shows the elastic modulus and strength at each stretching ratio. It can be seen that by increasing the draft ratio, a drawn product with high strength can be obtained even at a drawing ratio of about 8 times.

Table 2 Example ultra-high molecular weight polyethylene ([η) = 8.20 dl/g)
and paraffin wax (melting point -69°C1 molecular weight = 46
25775 blend with 0) was subjected to melt spinning and drawing under the same conditions as in Experimental Example 1. However, the orifice diameter is 2mm.
Push out the melt through the guide, air gap: 10a
It was solidified with cold water at 20°C. At this time, the fibers were drawn down so that the diameter of the cooled and solidified fibers was 0.04 mm. That is, Table 6 shows the elastic modulus and strength at each stretch ratio of 0 with a draft ratio of 50. It can be seen that by further increasing the draft ratio compared to Experimental Example 2, a drawn product with high strength can be obtained even at a drawing ratio of about 6 times.

Table 3 Comparative Example 1 Ultra-high molecular weight polyethylene ([η)-8,20a#/g)
and paraffin wax (melting point = 69°C1 molecular weight = 46
25775 blend with 0) was subjected to melt spinning and drawing under the same conditions as in Experimental Example 1. However, the orifice diameter is 1mm.
Push out the molten material through the guide, air gap = 10c
It was solidified with cold water at 20°C at 11t. At this time, Su1
No scraping was done at all. That is, the swelled molten resin was directly cooled and solidified. The diameter of the fiber obtained by cooling and solidifying is 5.3 mm, and the draft ratio is 0 by definition.
．． It was calculated as 3. It can be seen that without drafting, a drawn product with high strength was not obtained even at a drawing ratio of 25 times.

Table 4 In this experimental example, the elastic modulus and strength were plotted against the drawing ratio in FIGS. 1 and 2 in order to investigate the influence of draft. Furthermore, the strength is plotted against the elastic modulus in Figure 3.

The elastic modulus and strength are influenced by draft and show a markedly different dependence on the draw ratio. If a drop is applied during melting, a drawn product with a high elastic modulus and high strength can be obtained, whereas if a σ1 drop is not applied during melting, a drawn product with high strength can be achieved although a high modulus can be achieved. It is clear from FIG. 5 that this cannot be obtained. That is, it can be seen that high elastic modulus and high strength fibers can be obtained by applying a draft before cooling and solidifying.

[Brief explanation of the drawing]

FIG. 1 shows the relationship between elastic modulus and stretching ratio, FIG. 2 shows the relationship between strength and stretching ratio, and FIG. 3 shows the relationship between strength and elastic modulus. Applicant Mitsui Petrochemical Industries Co., Ltd. Agent Kazuzu Yamaguchi 1 0 10 20
30 Stretching ratio diagram 2 Stretching ratio diagram 5 0 10 20 30 40
50 60 Modulus of elasticity, (]Pa Procedural amendment (spontaneous) Kazuo Wakasugi, Commissioner of the Japan Patent Office1, Indication of the case, Patent Application No. 59976, filed in 1982, Title of the invention: Ultrapolymer ■ Process for manufacturing stretched polyethylene product 3 Amendment Patent applicant (58B) Mitsui Petrochemical Industries Co., Ltd. 4, Agent 〒io. 3-2-5-5 Kasumigaseki, Chiyoda-ku, Tokyo Voluntary amendment 64 Details of the invention in the specification subject to amendment Explanation Column 7 Contents of the amendment (1) Insert the phrase "- (two pairs if two-stage stretching is performed)" after the phrase "one to - one" on line 15E713 of the specification. (2) Details Insert the phrase "[and fifth godettrol]" after the phrase "second godettrol" on page 15, line 17 of the specification. (3) Insert the phrase "fiber obtained" on page 15, line 19 of the specification. Later, ``Experiment No. 1 was one-stage stretching using only the second godet roll, and Experiments Nos. 2 to 6 were drawn using the second godet roll in advance to a stretching ratio of 10.0 times, and then the second-stage stretching was performed. The predetermined stretching ratio was achieved with 6 godet rolls.
Insert the word or phrase. (4) In the first line of page 16 of the specification, the phrase "and strength" is amended to read "-1 strength and amount of residual paraffin." (5) After the phrase “obtained” on page 16, line 10 of the specification, the amount of r- or s-distilled paraffin wax (residual paraffin amount)
The paraffin wax was removed from the fibers after soaking them in n-1 xane for a day and night, and the fibers were quantified by weight loss. Insert the phrase ``. (6) The following column is added to the bottom column of Table 1-1 (below the strength column) on page 17 of the specification. [(7) On page 18, line 10 of the specification, before the phrase “each stretching ratio”, it is written that “Experiment No. 7 was a single-stage stretching using only the second godet roll, and experiments No. 8 to 10 were using the second godet roll. After pre-stretching to a stretching ratio of 8.0 times, a second stage of stretching was then carried out using a third godet roll to a predetermined stretching ratio.'' (8) On page 18, line 10 of the specification, ``and strength -1 There is,
", strength and amount of residual paraffin - 1. (9) Add the following column to the bottom column of Table 2-1 (below the strength column) on page 18 of the specification." aO details On page 19, line 10 of the book, ``Before each stretch ratio -1 phrase,'' ``Experiment number 11 was one-stage stretching using only the second godet roll, and experiment numbers 12 to 14 were drawn using the second godet roll.'' cr
After the film was previously stretched to a stretching ratio of 5.6 times using a second godet roll, a second stage of stretching was performed using a second godet roll to a predetermined stretching ratio. -10 strength On page 19 of the specification, line 10, "strength - 1" is corrected to ", strength and amount of residual paraffin - 1". 3- "" θ [Yes] "Calculated.-1" on page 20, line 11 of the specification.
After the phrase, [Experiment No. 15 is one-stage stretching using only the second godet roll, Experiment Nos. 16 and 17 is stretching by 10.0 times using the second godet roll, and then the second-stage stretching. The stretching was carried out in a third Godet wheel to a predetermined stretching ratio. Insert the phrase ``. 010 The following column is added to the bottom column (below the strength column) of "Table 4" on page 20 of the specification. "" 0υ Ultra-high molecular weight polyethylene ([η) = 8.21/g) = 4- and paraffin wax (melting point = 84°C, molecule 1 = 70
A 50:50 blend with 0) was molded in a T-die mold under the following conditions and then stretched. After mixing ultra-high molecular weight polyethylene powder and crushed paraffin wax,
Using a screw extruder with a diameter of 0 mm and L/D = 20, the pellets were melt-kneaded and pelletized at a resin temperature of 190"C.Then, the pellets were passed through a 220"O coat hanger type die (lip length = 300mm, lip thickness = 0.5mm). A film was formed using a screw extruder with a diameter of 20 mm and a L/D=20. Using a roll cooled with 20°C cold water, roll 300mm so that the film width is 43mm.
A film was prepared by drawing down from the width lip during melting. That is, the draft ratio was set to 50. A stretching tank (tank temperature =
Stretching was performed at 130° C. (length of one tank = 80 ffl). During stretching, the rotational speed of the first snap roll was set to 0.
5 m/mi, n, the second snap roll and the fifth
Stretched tapes with different stretching ratios were obtained by appropriately changing the rotational speed of the snack roll. 8 Stretching was carried out using only the second Snut roll in Experiment No. 1.
In stage stretching, experiment numbers 19 to 21, the film was first stretched to a stretching ratio of 2.0 times using a second snap roll, and then the second stage stretching was performed at a predetermined stretching ratio using a fifth snap roll. However, the stretching ratio was calculated from the rotation ratio of each snap roll. The stretched tape at each stretching ratio was measured at room temperature (
The elastic modulus, strength and tape width measured at 23°C are summarized in Table 5. Table 5 Comparative Example 2 Ultra-high molecular weight polyethylene ([η]-8.2d, g/g
) and high-density polyethylene (melting point -130" C1 molecule■
=40,0DD) in Experimental Example 1.
A T-die film was formed under the same conditions as described above, and then stretched. In this system, a film with a width of 50 D mm was formed because stretching breakage occurs if a drawdown is applied during melting. In experiment No. 22, the stretching was done in one stage using only the second Snut roll, and in Experiments Nos. 25 to 25, the second Snut roll was used to stretch to a stretching ratio of 5.4 times, and then the second stage of stretching was performed using the third Snut roll. A predetermined stretching ratio was achieved. Table 6 summarizes the elastic modulus, strength, and tape width of the stretched tape at each stretching ratio. In this system, a high draw ratio could not be achieved, resulting in high elasticity and high stability. 6 Example ultra-high molecular weight polyethylene ([η) = 8.20 af
f/g) and paraffin wax (melting point = 69°C, molecular weight = 460) was subjected to melt spinning and drawing under the same conditions as in Experimental Example 1. However, if the orifice diameter is 4. The melt was extruded through an Omm die and solidified with cold water at 20° C. with an air gap of 10 Cfn. At this time, the fibers were drawn down so that the diameter of the cooled and solidified fibers was 0.80 mm. Immediately, in the 1st and 3rd stretching with a draft ratio of 5, the stretching ratio + 0 is preliminarily set in the second godet wall.
．． After stretching to 0 times, a second stage of stretching was performed at a predetermined stretching ratio using a third godet roll. Table 7 shows the elastic modulus, strength, and residual amount of paraffin at each stretching ratio. Table 7 Example ultra-high molecular weight polyethylene ([η] = 8.201/)
and paraffin wax (melting point = 69”C, molecular weight = 46
0) and 25Nia5 blend was subjected to melt spinning and drawing under the same conditions as in Experimental Example 1. However, the orifice diameter is 2mm.
Extrude the molten material from the Gui, ]-Argy V-tub; 1
Assimilated in cold water at 20°C at 0 m. At this time, the fibers were drawn down so that the diameter of the cooled and solidified fibers was 0.20 mm. That is, the draft ratio was set to 10. Stretching was carried out in experiment number "1", 0-35 was one-stage stretching using only the second godet roll, and experiment numbers 34-37 were drawn in advance with the second godet roll to a stretching ratio of 8.0 times, and then the second-stage stretching was carried out. The stretching was carried out to a predetermined stretching ratio using a third godet roll.The elastic modulus, strength and residual amount of paraffin at each stretching ratio are shown in Tables 8 and 9. Table 8 Table 9 Examples Ultra-high molecular weight polyethylene ([η) = 8. 20 dn
/g) and paraffin wax (melting point = 69°01 molecular weight = 460) in Experimental Example 1.
Melt-spinning and drawing were performed under the same conditions as described above. However, the melt was extruded through a gouie with an orifice diameter of 1 mm and solidified in cold water at 20° C. with 10 air gaps. On this occasion,
The fibers were drawn down so that the diameter of the cooled and solidified fibers was 0.20 mm. That is, the draft ratio was set to 5. Note that the paraffin wax used in the above blend was used as the heating medium in the stretching tank instead of the n-decane used in Experimental Series 1. In experiment No. 38, the stretching was carried out in one step using only the second godet roll, and in experiments No. 39 to 42, the second godet roll was used to draw the stretching ratio to 7.0 times, and then the second step of drawing was carried out using the sixth godet roll. The stretching was carried out to a predetermined stretching ratio. Table 10 shows the elastic modulus, strength, and residual amount of paraffin at each stretching ratio. Although the residual amount of paraffin is somewhat larger than that of the n-decane heating medium, it is seen that as the stretching ratio increases, the residual amount of paraffin decreases. Table 10 Example 8 Ultra-high molecular weight polyethylene ([η) = 8.20 an
/g) and paraffin wax (melting point = 109°C, molecular weight = 900) was melt-spun and stretched under the same conditions as in Example 1. However, the molten material was extruded through a gouie with an orifice diameter of 2.0 mm and solidified with cold water at 20° C. with an air gap of 10 ports. At this time, the fibers were drawn down so that the diameter of the cooled and solidified fibers was 0.4 mm. That is, the draft ratio was set to 5. still,
As the heating medium in the stretching tank, silicone oil was used instead of n-decane used in Experimental Example 1. For the stretching, experiment number 43 was one-stage stretching using only the second godet roll, and experiment numbers 44 to 46 were drawn in advance with the second godet roll at a stretching ratio of 6.0 times.
Subsequently, a second stage of stretching was performed using a third godet roll to a predetermined stretching ratio. The results of the elastic modulus and strength of the obtained drawn fibers are summarized in Table 11 together with the residual amount of paraffin wax. Because cicoline oil and paraffin wax are incompatible,
Although the paraffin wax cannot be completely removed from the fiber surface, it can be seen that the paraffin wax can be removed by stretching in this experiment compared to the original yarn. Further, paraffin wax remaining on the drawn fibers can be completely removed by washing with a solvent such as hexane, and by completely removing paraffin wax, it is possible to improve the elastic modulus and strength. Table 12 summarizes the results of the elastic modulus and strength of the drawn fibers after washing with hexane. Table 11 Table 12 -97

Claims (1)

[Claims] (1) Is the intrinsic viscosity at least 5d7? /g or more ultra-high molecular weight polyethylene (A) 15 to 80 parts by weight and paraffin type 1 NOx having a melting point of 40 to 120°C and a molecular weight of 2000 or less (B) 85 to 20 parts by weight. The unstretched material was melt-kneaded in a screw extruder at a temperature of 280'C, extruded through a 21D to 30D"C glue, and cooled and solidified after passing through a draft of at least 1.1+1. 1
．． , production of a drawn ultra-high molecular weight polyethylene product characterized by IV drawing at a temperature of 140°C and a drawing ratio of at least 5 times;