JPH04108108A - Drawn propylene polymer and production thereof - Google Patents

Abstract

PURPOSE:To obtain drawn propylene polymer excellent in breaking strength and elongation, elastic modulus and quantity of output energy by melt spinning propylene polymer under specific conditions, drawing and post-drawing the resultant fiber. CONSTITUTION:Propylene polymer having >=3.5dl/g intrinsic viscosity is drafted and melt spun so as to provide >=1.2 crystal orientation ratio (C-axis crystal orientation intensity/a'-axis crystal orientation intensity) of the C-axis crystal orientation to the a'-axis crystal orientation in the resultant raw fiber measured by an X-ray diffractometry and the obtained raw fiber is then post-drawn at 2-50 times draw ratio to afford the objective drawn propylene polymer having >=0.7GPa breaking strength, >=20% breaking elongation, >=4.0GPa elastic modulus and >=3.0kgfm/g quantity of output energy after repeating 50% load of the breaking strength.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention relates to a drawn propylene polymer and a method for producing the same, and more specifically, it relates to a drawn propylene polymer having a relatively high molecular weight, that is, a polypropylene having a relatively high molecular weight, that is, a polypropylene with an intrinsic viscosity [ηJ is at least 3.5 dβ/g or more, by melt-spinning a propylene polymer with a draft of at least 3.5 dβ/g without using a flow aid, breaking strength, breaking elongation,
The present invention also relates to a stretched propylene polymer with excellent output energy and a method for producing the same.

[Prior art and its problems] The polypropylene strong yarn currently on the market usually has an intrinsic viscosity [η] of 2.6d9 even when the raw material has the highest molecular weight.
/g, and although the elongation at break is large, the strength at break is 0.
It is about 5 to 0.6 GPa, and the amount of output energy is also small and unsatisfactory. This is because polypropylene with a sufficiently large molecular weight could not be used in terms of moldability. In other words, although high strength can be expected if spinning is performed using raw materials with sufficiently high molecular weight,
Polymer 1 is difficult to use with conventional techniques in terms of fluidity and moldability, so molding is limited to low molecular weight products.

On the other hand, many attempts have been made to find ways to utilize high molecular weight polypropylene. For example, Kuchiki et al.
Applying the successful zone stretching method for polyethylene to polypropylene, polypropylene with a molecular weight of 4.75 million was stretched to achieve an elastic modulus of 16.9 GPa and a modulus of 0.
Polypropylene fibers with a tensile strength of 74 GPa are obtained. (Journal of Applied Pol
ymer 5science, Vnl, 28. P179～
189°1983+. Here, the zone drawing method refers to one or two fibers prepared in advance by conventional melt-spinning methods, etc.
This is a method in which super-stretching is performed by heating a mm-thick section using a local heating furnace and stretching the section. In addition, as an example of applying the gel fiber/ultra-stretching method to polypropylene, there is a report by Peguy and Man I ey (Polymer
er Communication, Vol. 25.
P39-42.1984), and they described the method adopted by Sm1th and Lemstra in ultra-high molecular weight polyethylene (Journal of Polymer Bu
Gel spinning and super-stretching were performed using a 0.75 to 1.5 wt% solution using a method similar to that of J. Illetin, Vol. 1.733.19791, and an elastic modulus of 36 GPa and a tensile strength of 1.03 GPa were obtained. Polypropylene fibers having the following properties are obtained.

Furthermore, JP-A-58-5228 also discloses an example of polypropylene, which has an intrinsic viscosity [η
1) From a solution of ultra-high molecular weight polypropylene of 8 dI2/g (molecular weight 3.3 million) at a concentration of 6% by weight, an elastic modulus of 2:
1.9 GPa and a tensile strength of 1.04 GPa.

However, when examining ultra-high molecular weight polypropylene fibers or tapes obtained by methods using conventional methods for preparing ultra-high molecular weight polyethylene fibers, it was found that ultra-high molecular weight polypropylene fibers or tapes obtained using any of the methods The elastic modulus of the polypropylene drawn yarn or tape is about 7 to 10 GPa, and the tensile strength is about 0.5 to 1.04.
It is about GPa. By the way, the theoretical strength of ultra-high molecular weight polypropylene is about 32 GPa, the theoretical strength of ultra-high molecular weight polypropylene is about 18 GPa, and the theoretical strength of ultra-high molecular weight polypropylene is about 1/2 of the theoretical strength of ultra-high molecular weight polyethylene. It is already known that it will happen. ([Textiles and Industry J Vol, 40. P.

407-418.19841° At present, all ultra-high molecular weight polyethylene fibers have a bow tensile strength of about 6 GPa, and from this value, the tensile strength of ultra-high molecular weight polypropylene fibers is 0. Values of .5 to 1.04 GPa are not necessarily satisfactory values. That is, as for ultra-high molecular weight polypropylene, the tensile strength should be 3 GPa, and based on this value, the actual situation is that the tensile strength has hardly been improved.

An example of a successful improvement in the tensile strength of ultra-high molecular weight polypropylene is the method reported by Kanae et al. (Journal of the Japan Institute of Textile Science and Technology, 1988 Annual Conference Research Presentation Proceedings). In this method, a solvent cast film is prepared by evaporating the solvent from an ultra-high molecular weight polypropylene solution with a concentration of 1% or less, and then this film is sandwiched between polyethylene biurets on both sides to form a pseudo-melt state. After solid-phase stretching, and further stretching to about 6 times by passing through a conical die, this in-phase stretched film was subjected to ordinary tension stretching to obtain highly drawn fibers with a stretching ratio of about 72 times. Since this method uses a polyethylene billet, even if a fragile sample is used, it can be stretched at a high stretching rate without damaging or breaking the sample. Specifically, this method uses ultra-high molecular weight polypropylene with a molecular weight of 3.6 million,
A stretched molded body having a tensile strength of 2.3 GPa was obtained.

However, this method is difficult to continuously produce fibers and is extremely disadvantageous in terms of industrial productivity and cost. Further, the elongation at break of the ultra-high molecular weight polypropylene stretched molded article obtained by this method is extremely small. That is, ultra-high molecular weight polypropylene fibers are produced by preparing a dilute solution of ultra-high molecular weight polypropylene in -1, and highly drawing gel fibers spun from this solution.

However, when such gel spinning/ultra-stretching methods are used, the fibers inevitably have a high elastic modulus, and although high strength can be obtained, the elongation rate of the fibers decreases, resulting in lower output. In terms of energy content, the energy content must be extremely low. Furthermore, when such fibers are used as an energy regenerating elastic body such as a spring, not only do they have a small amount of stored energy, but their elongation rate is also low, so the energy regeneration time is significantly shortened, making them effective. accumulate energy,
Unable to play.

On the other hand, by heat-treating the spun fibers while applying a temperature gradient and shear stress to the fibers during spinning, it is possible to
It is known that it is possible to obtain eight-doped elastic fibers that recover their elasticity without undergoing plastic deformation even under deformation close to 10%.
, 1. P, 18-21.19701゜In addition, it has been reported that hard elastic fibers with a high elongation rate can be obtained by spinning polypropylene at high speed and heat treating it (Fibers and Industries Vol.
36. P, 51-57.19801゜It has also been reported that porous polypropylene fiber has an elongation rate of 40% and that this fiber is suitable for an elastic body for energy regeneration (Japanese Patent Laid-Open No. 63-24971). ), but the strength of the fibers still remains low in this case as well.

All of these methods require heat treatment of the fibers at some stage after spinning, and because this heat treatment process is complicated, drawn fibers with high strength and high elongation at break cannot be produced industrially. It is disadvantageous as a production method.

Furthermore, there is a limit to the improvement of fiber elongation by such heat treatment, and it has been difficult to sufficiently increase the energy output of fibers using this ultra-high molecular weight polymer.

Furthermore, Japanese Patent Application Laid-open No. 2-41412 discloses that the main component is crystalline polypyrene with a melt index value of 1 to 5, the single yarn has a fineness of 1 to 10 deniers, and 80% of the breaking strength. A highly elastic polypropylene fiber having an elastic recovery energy amount of 5°0 kgf/g or more after 10 repetitions of loading is described.

However, considering the melt index value of 1 to 5 disclosed herein, the molecular weight of the polypropylene fiber is approximately 3 in terms of intrinsic viscosity [η1].
The amount of elastic recovery energy of the crystalline polypropylene fiber disclosed in the Examples after 80% load of the breaking strength is repeated IO times is also 5 to 8 kgfm at most.
/g was obtained.

[Objective of the Invention J The present invention has been proposed in order to solve the problems associated with the prior art as described above, and its objectives are to achieve high strength, high elongation at break, and Excellent output energy amount. The object of the present invention is to produce a drawn propylene polymer having a relatively high molecular weight by a melt spinning method.

[Means for solving the problem] That is, according to the present invention, the breaking strength is 0.7GP.
a or more, elongation at break is 20% or more, modulus of elasticity is 4, 0GPa
Provided is a stretched propylene polymer having high strength and excellent output energy, which is characterized by the above and the output energy after IO repetitions of a 50% load of breaking strength is 3.0 kgfa+/g or more. .

Furthermore, according to the present invention, there is provided a method for producing the stretched propylene polymer, which is characterized in that the intrinsic viscosity [η1 is at least 3.
When melt spinning a propylene polymer north of 5 dff/g, the ratio of the C-axis crystal orientation to the a'-axis crystal orientation in the raw fiber (C-axis orientation strength/a'-axis crystal orientation strength) is 1. The crystal structure in the yarn is adjusted by spinning with a high draft so that the yarn has a high draft, and then the yarn is heated and then stretched to achieve high strength and elongation at break. The objective is to obtain a stretched propylene polymer that is large and has a large amount of output energy.

[Description of Preferred Embodiments of the Invention] The stretched propylene polymer product and the method for producing the same according to the present invention will be specifically described below.

A major feature of the present invention is that it makes it possible to produce a drawn product having extremely high breaking strength and output energy, which cannot be achieved by polypropylene spinning using the conventional melt spinning method.

That is, the propylene polymer drawn product according to the present invention is melt-spun by applying a high draft and slowly cooling to produce a special raw fiber in which the crystal orientation axis direction is almost C-axis orientation. By further post-stretching, a stretched product with high strength and a large amount of output energy can be obtained.

Generally, in the gel spinning method, the quasicrystalline mat method, the wax blend method, or the conventional melt spinning method, a method of drawing fibers is used as a method for improving the strength of the fibers. However, as the stretching ratio increases, the molecules become highly oriented, so the elastic modulus generally increases, and as a result, the elongation rate decreases.

When fibers with such reduced elongation are used as elastic bodies for energy regeneration, lobes, and especially so-called moving ropes such as mooring ropes and towing lobes, energy regeneration time becomes short or excessive loads are applied momentarily. Sometimes it breaks easily. Therefore, it is desirable that the propylene polymer stretched product used as an energy regeneration elastic body or a running rope be a fiber that has high strength, high elongation, and a large output energy amount.

However, since both strength and elongation are factors caused by molecular orientation, conventional methods change both in conjunction with each other, thus maintaining the strength at a constant level without decreasing it. , and it was difficult to improve the elongation rate.

When producing propylene polymer fibers or films, the present inventors used a high-molecular-weight propylene polymer that has never been used in conventional melt-spinning methods, and further melt-spun the raw yarn. By applying a high draft in the step and slow cooling, a raw yarn with a crystal structure in which the lamellae (crystals before stretching) are arranged perpendicular to the fiber axis direction is prepared, which is measured by XwA diffraction method. We produced a raw yarn with a crystal structure in which the crystal orientation ratio (C-axis crystal orientation strength/a'-axis crystal orientation strength) was 1.2 or more and had only the C-axis crystal ν direction. They discovered that by post-stretching this raw yarn at a stretching temperature of 60 to 120°C, it was possible to obtain fibers with high strength and high elongation at break (as well as a large amount of output energy). This led to the invention.

The propylene polymer used in the present invention will be explained below.

Propylene Polymer The propylene polymer used in the present invention has an intrinsic viscosity [η1] of at least 3.5 dl/g, preferably 4.0 dff/g, more preferably 5.5 dl°, as measured in a decalin solvent at 135°C. It is 7g or more. As the molecular weight of a stretched propylene polymer increases, its tensile strength at break tends to increase. On the other hand, from the viewpoint of formability by the melt spinning method, the limit viscosity [η] of propylene polymer that can be spun is approximately 7 d ff/g, and if [y+] is higher than that, the The spinnability is lost and it becomes impossible to spin by applying a draft.

However, even if it is a high molecular weight material with an intrinsic viscosity [η] of 7 d 127 g or more, it can be easily spun by adding fluidizing aids such as liquid paraffin, waxes, tetralin, etc. However, there is a risk that the features of the stretched product as referred to in the present invention may be lost. Therefore, regardless of the molding method, the upper limit of the intrinsic viscosity [η] is generally 30 d ff/
g, but the upper limit of the molecular weight that can be preferably spun without using a fluidization aid in the melt spinning method is the intrinsic viscosity [
r+] is about 7dI2/g.

The propylene polymer in the present invention is a propylene homopolymer obtained by coordination anionic polymerization, or propylene and a small amount of other α-olefins, such as ethylene, l
-butene, 4-methyl-1-pentene, 1-pentene,
A propylene polymer made of a copolymer of 1-hexene, 1-octene, -decene, etc. is used.

Further, the propylene polymer used in the present invention may be used alone, or may be blended with a small amount (for example, 30% by weight or less) of other resins, such as polyethylene or α-olefin polymer. The polyethylene mentioned here may be polyethylene produced by high pressure method, medium pressure method, or low pressure method. The α-olefin polymer is a polymer obtained by polymerizing or copolymerizing α-olefins having one or more ethylenic double bonds and having 4 or more carbon atoms, preferably carbon fjR of 4 to I8. It is a combination or copolymer. Specific examples of such a-olefin polymers having 4 carbon atoms include polybutene-1, poly-1-pentene, poly-1-hexene, poly-3-methyl-1-butene, and poly-1-pentene. 4-methyl-1-pentene,
Poly-4=methyl-1,3-pentadiene, poly-5-
Methyl-1-hexene, poly-4-methyl-1-hexene, poly-4-phenyl-1-butene, poly-I-heptene, poly-nioctene, poly-l-nonene, poly-
Examples include 1-decene.

Such polymers and polyethylene are dissolved in decalin solvent at 1
Intrinsic viscosity measured at 35°C [η1 is 2.0 dβ/g
or more, preferably 3.0 dff/g or more.

On the other hand, the upper limit of the intrinsic viscosity [ηJ is not particularly limited as long as it does not impair the performance of the melt-spun raw yarn, but it is generally not more than the intrinsic viscosity [η] = 30 dI2/g, and preferably the intrinsic viscosity [η] = 15 dl /g or less. Further, the blending amount of these other resins needs to be such that the stretched molded product does not lose the characteristics of polypropylene. Therefore, the blend amount is 30% by weight or less, preferably 10% by weight or less.

To explain the method for producing a stretched propylene product of the present invention, the unstretched molded product, that is, the raw thread, is produced by adjusting the intrinsic viscosity [η
] is obtained by melt-spinning a propylene polymer having 3.5 dl/g or more. Here, the propylene polymer is
For example, raw yarn can be obtained by extruding it from a spinneret of a die of a screw extruder. At this time, the number of spinnerets in the die may be a single hole or multiple holes of two or more. The temperature at this time is usually 170°C to 360°C, preferably 190°C to 320°C, particularly preferably 210°C to 280°C, and by setting this temperature, stable filaments can be spun. in this case,
The melt extruded from the spinneret can be spun while applying tension. The draft ratio at this time is 5 to 1000, but in other words, it is preferable to have a crystal structure in which lamellae (crystals before stretching) are arranged perpendicular to the fiber axis direction. That is, the C-axis is such that the crystal orientation ratio (C-axis crystal orientation strength/a'-axis crystal orientation strength) measured by X-ray diffraction is 1.2 or more, more preferably 1.6 or more. This involves spinning with a high draft so that the yarn has a crystalline structure that only has a high binding orientation. Here, the crystal orientation ratio (C-axis crystal orientation strength/a'-axis crystal orientation) of the stretched propylene polymer obtained by the X-ray diffraction method is X! I generator (RU30 manufactured by Rigaku Denki)
0) Maximum output 50kV-300mA, Cu target,
The measurement was carried out using a fiber sample stand (manufactured by Rigaku Denki ■) with a gear ratio of 4:1, a collimator φ1 mm, and a counter (manufactured by Rigaku Denki ■).

Place the sample on the fiber sample stand with the fiber axis direction fixed parallel to the meridian direction. While rotating this sample, among the reflections of X-ray diffraction, the intensity was measured along the Debye ring of the strongest paratropic plane on the equator line (in the case of propylene polymer, it is (1)0) plane reflection). Measure the distribution curve. Specifically, the counter is fixed at the reflection position (2θ=21.4°) of the (100) plane, and the sensitivity is adjusted so that the pen of the recorder is at an appropriate position.

The rotating gear ratio of the fiber sample stage was set to 4:l, the chatos bead was set to 2 cm/min, the sample was rotated B from 00 to 1800 degrees, the X-ray intensity was measured, and the X-ray interference diagram as shown in Figure 1 was obtained. get. From FIG. 1, it is expressed as the ratio of the peak area IB of the C-axis crystal orientation intensity to the peak area A of the a′-axis crystal orientation intensity, and is defined by the following formula.

Crystal orientation ratio = The crystallization rate of the molten material extruded from the die in this way is controlled by cooling it using a forced cooling means such as air cooling, water, metal vine, or acetone without applying a draft. However, it is preferable to make the air gap from the spinneret to the take-up roll as long as possible for slow cooling. That is, it is preferable to cool slowly under draft tension to give sufficient time to form a higher-order crystal structure in which lamellae are arranged perpendicularly to the fiber axis direction.

Further, as long as the falling melt spinning temperature does not interfere with molding, it is desirable to perform spinning at the lowest possible temperature in the range of 170 to 360° C. in order to prevent thermal deterioration of the resin and to increase draft tension.

Note that the draft ratio here represents the ratio between the inner diameter Do of the spinneret and the diameter of the raw yarn obtained by cooling and solidifying the fallen melt and winding it up,
It is defined by the following formula.

Draft ratio = D, /D Kaku Tsuji The propylene polymer yarn obtained in this way was
By further stretching, a stretched product with high strength, high elongation at break, and high output energy can be obtained.

The propylene polymer yarn is generally drawn at a drawing temperature of 6
0 to 210℃, preferably 120 to 170℃,
Most preferably it is carried out within the temperature range of 140 to 160°C. The heat medium used at this time is air,
Either water vapor or liquid medium can be used. Further, the stretching ratio is 2 to 50 times, preferably 3
from 1 to 15 times, most preferably from 4 to 8 times. This stretching operation is performed in -stage or in multiple stages of two or more stages.
Although any method can be used, it is advantageous to carry out the stretching at as high a stretching temperature as possible, at a stretching ratio as high as possible, and in addition, by -stage stretching. In addition, the crystal melting temperature of a stretched propylene polymer tends to increase as it is stretched, so when carrying out multi-stage stretching, each stretching stage after the -th stage is 15 to 20°C higher than the previous stage. It is important to set the temperature to the eye level. Here, the stretching ratio is expressed as a ratio between the unwinding speed R6 of the raw yarn and the winding speed R1 of the drawn material, and is defined by the following formula.

Stretching ratio = R, /R.

Propylene East A stretched product The propylene polymer stretched product thus obtained is as follows:
The main component is a propylene polymer having an intrinsic viscosity [η] of 3.5 dβ/g or more.

Furthermore, the tensile strength at break of the drawn product is usually 0.
7 GPa or more, preferably 1.0 GPa or more, more preferably 1.0 GPa or more. I GPa or more, and the elongation at break is usually 20% or more, preferably 30% or more, and more preferably 40% or more.

In addition, the elastic modulus of this stretched propylene polymer is 4.0
GPa or more, the output energy amount determined from the 50% breaking strength of the strength and elongation curve is usually 3.0 kgfm/g or more, preferably 3.5 kgfm/g or more, more preferably 4
．． 0 kgfa+/g or more.

The amount of energy output in the drawn product can be measured by one of a variety of methods. - For example, a simple method can be proposed to determine the amount of output energy from the area of the strength and elongation curve after 10 repetitions of a load of 50% of the stress required for rupture.

In other words, during a tensile test, the vertical axis is the stress,
If the horizontal axis is set as elongation, 50% of the rupture in the stress/strain curve
Draw a perpendicular line from the part corresponding to the load, and the part surrounded by this perpendicular line, the horizontal axis, and the stress/strain curve corresponds to this output energy amount.

The propylene polymer stretched product obtained as above is
It has high breaking strength and high breaking elongation (and has excellent creep resistance and output energy. This stretched propylene polymer has particularly high strength and high elongation, so it is suitable for energy regeneration. It can be used as an elastic body, in moving ropes such as mooring lobes and towing lobes, and as reinforcing fibers for epoxy resins, unsaturated polyester resins, and the like.

[Example] Next, the present invention will be explained in more detail with reference to Examples.
The present invention is not limited to these examples in any way as long as it does not go beyond the gist of the invention.

1) Relatively high molecular weight polypropylene with a 0° intrinsic viscosity [η] of 6.0 dJ2/g was extruded at a resin temperature of 245°C using a plunger type extruder equipped with a 0.8+a+++φ spinning nozzle. . This extruded melt is 80
The yarn was wound onto a bobbin at a draft ratio of 64 in air at 25° C. under an air gap of cm.

In addition, as a process stabilizer, 3.5-G Lert-
Butyl-4-hydroxytoluene and tetrakis [
Methylene-3(3,5-di-tert-butyl-4-hydroxyphenylene)propionate]methane was added in an amount of 01% by weight based on the high molecular weight polypropylene.

This yarn was drawn in a drawing tank (effective horizontal length:
One step of stretching was performed by 0 cm1. The stretching conditions were 5.5 times the stretching at 150°C.

Note that the rotation speed of the first godet roll is 25 cm/min, and the rotation speed of the second godet roll is 137.5 cm/min.
It was stretched at +/lll1n.

Here, the stretching ratio is determined by the rotational speed ratio of the second godet roll and the first godet roll.

Table 1 shows the breaking strength, tensile modulus, breaking elongation, and
The amount of output energy is listed.

The propylene polymer stretched product obtained as above is
It has high breaking strength, high breaking elongation, excellent creep resistance, and excellent output energy.

! A relatively high molecular weight polypropylene having an intrinsic viscosity [ηJ of 6.0 dβ/g] was extruded at a resin temperature of 230° C. using a plunger type extruder equipped with a spinning nozzle of 1.0 mm diameter. The extruded melt was wound around a bobbin at a draft ratio of 93 in air at 25° C. under an air gap of 80 cm to obtain a yarn.

In addition, as a process stabilizer, 3,5-tert-
Butyl-4-hydroxytoluene and tetrakis [
Methylene-3(3,5-di-tert-butyl-4-hydroxyphenylene)propionate]methane was added in an amount of 0.1% by weight based on the high molecular weight polypropylene.

This raw yarn is drawn in a drawing tank (effective horizontal length 5.
One step of stretching was performed by 0 cm1. Stretching conditions are 150℃ and 4
．． It was stretched 5 times.

The rotation speed of the first godet roll is 25 cmZ, and the rotation speed of the second godet roll is 1) 2.5 cm.
Stretched with /+ain.

Here, the stretching ratio is determined by the rotational speed ratio of the second godet roll and the first godet roll.

Table 1 shows the breaking strength, tensile modulus, breaking elongation, and
The amount of output energy is listed.

The propylene polymer stretched product obtained as above is
Like the one obtained in Example 1, it has high breaking strength (and high breaking elongation), excellent creep resistance, and excellent output energy.

! Comparatively high molecular weight polypropylene with an intrinsic viscosity [η] of 6.0 dJ2/g was extruded at a resin temperature of 220°C using a plunger type extruder equipped with a 2.0 mm spinning nozzle. . 80cm of this extruded melt
The yarn was wound onto a bobbin at a trough ratio of 91 in air at 25° C. under an air gap of 25° C.

As a process stabilizer, 3,5-di-tert-butyl-4-hydroxytoluene and tetrakis[methylene-3(3,5-di-tert-butyl-4-hydroxyphenylene)propionate comethane were added to the high molecular weight polypropylene in Q. , was used by adding 1% by weight.

This raw yarn was drawn once in a drawing tank (effective horizontal length: 50 cm) containing two Godetstrols and Flusol P (thermal medium manufactured by Thermal Kagakusan ITM). The stretching conditions were 4.5 times the stretching at 150°C.

The rotation speed of the first godet roll is 25 cm/min, and the rotation speed of the second godet roll is 150.0 cm/min.
/min.

Here, the stretching ratio is determined by the rotational speed ratio of the second godet roll and the first godet roll.

Table 1 shows the breaking strength, tensile modulus, breaking elongation, and
The output energy meter is listed.

The propylene tonne combined drawn product obtained as described above also has
It has high breaking strength, high breaking elongation, excellent creep resistance, and excellent output energy abrasion.

Example 4 A relatively high molecular weight polypropylene having an intrinsic viscosity [n] of 6.0 dI2/g was extruded at a resin temperature of 245° C. using a plunger type extruder equipped with a 0.8 mm ψ spinning nozzle.

In addition, as a process stabilizer, 3.5-tert-
Butyl-4-hydroxytoluene and tetrakis [
Methylene-3 (3,5-di-tert-butyl-4-hydroxyphenylene) propionate 1 methane was added in an amount of 0.1% by weight based on high molecular weight polypropylene.

The extruded melt was taken up with a touch roll in air at 25° C. under an air gap of 80 cm, and then wound around a bobbin to form a yarn. At this time, by changing the take-up speed of the touch roll, the draft ratio is set to 2.
1 to 847 yarns were obtained.

The crystal orientation ratio of the yarn thus prepared was measured by X-ray diffraction. That is, the maximum output of the X-ray generator (RU300 manufactured by Rigaku Denki ■) is 50 kV - 300 mA,
Cu target, fiber sample stand (manufactured by Rigaku Denki) gear ratio = 4:l, collimator ψImm, counter tube [Rigaku Denki ■]
Place the sample on a fiber sample stand with the fiber axis direction fixed parallel to the meridian direction. While rotating this sample, the intensity distribution curve is measured along the Debye ring of the strongest baratropic surface on the equator line among the X-ray diffraction reflections. Specifically, (1) the reflection position of the 0) surface (2θ=214°
) and fix the counter tube, and adjust the sensitivity so that the recorder pen is in the appropriate position.

Set the rotating gear ratio of the fiber sample stage to 4=1, set the chat speed to 2cm/n+i mouth, and rotate the sample from 00 to 180°.
X1) The intensity is measured by performing β rotations up to X1) to obtain an X-ray beam diagram as shown in FIG. From FIG. 1, it is expressed as the ratio of the peak area B of the C-axis orientation strength to the peak area A of the a-axis orientation strength, and is defined by the following formula.

Crystal orientation ratio=B/A Table 2 lists the draft ratio and crystal orientation ratio.

Moreover, this result is illustrated in FIG. By increasing the stretching ratio, the orientation of the crystal lamellae in the raw yarn becomes C-axis orientation.

Example 5 A relatively high molecular weight polypropylene with an intrinsic viscosity [η] of 6.0 dj2/g was extruded at a resin temperature of 245° C. using a plunger type extruder equipped with a 0.8 mm spinning nozzle. .

In addition, as a process stabilizer, 3,5-tert-
Butyl-4-hydroxytoluene and tetrakis [
Methylene-3(3,5-di-tert-butyl-4-hydroxyphenylene)brobionet-1methane was added in an amount of 01% by weight based on high molecular weight polypropylene.

The extruded melt was taken up with a touch roll in air at 25° C. under an air gap of 80 cm, and then wound around a bobbin to form a yarn. At this time, by changing the take-up speed of the touch roll, the draft ratio can be adjusted to 1.
A raw yarn of 3.2 to 97.5 was obtained.

The yarn with different draft ratios was drawn in one step using a drawing tank (effective width 50cm1) containing two Godetstrols and Flusol P (thermal medium manufactured by Thermal Kagaku Sangyo ■).The drawing conditions were 150℃ and 5.5 times. It was extended to.

The rotation speed of the first godet roll is 25 cm/min, and the rotation speed of the second godet roll is 137.5 cm/min.
/1IIin.

Here, the stretching ratio is determined by the rotational speed ratio of the second godet roll and the first godet roll.

Table 3 lists the draft ratio of the raw yarn, the output energy amount, and the breaking strength of these fibers. Also, this result can be used in the third
It is shown in FIG.

Example 6 Mi Limiting viscosity [n] 3.03 dff/g
, 4.30dR/g, 4.61dff/g, 6.01
dff/g = 6;'ropylene polymer, 0.8 mm
It was extruded at a resin temperature of 245° C. using a plunger type extruder equipped with a spinning nozzle. The second extruded melt was wound around a bobbin in air at 25° C. under an air gap of 80 cm at a draft ratio of 120 to 64 to obtain a yarn.

In addition, as a process stabilizer, 3.5-tert-
Butyl-4-hydroxytoluene and tetrakis [
Methylene-3(3,5-di-tert-butyl-4-hydroxyphenylene)propionate]methane was used by adding 0.1% by weight of each to high molecular weight polypropylene.

This raw yarn was drawn in a drawing tank (effective width: 50 mm
One stage of stretching was performed by cm1. Stretching conditions are 150℃ and 5
．． It was stretched 5 times.

The rotation speed of the first godet roll is 25 cm/min, and the rotation speed of the second godet roll is 137.5 cm/min.
/ll1n.

Here, the stretching ratio is determined by the rotational speed ratio of the second godet roll and the first godet roll.

Table 4 shows the intrinsic viscosity of the propylene polymer used here [
η] and the measurement results of the output energy amount are listed. Also,
The results are illustrated in FIG.

Comparative Example 1 Intrinsic viscosity [η] is 19.30 dI;! /g of ultra-high molecular weight polypropylene powder and the intrinsic viscosity [η] is s,
0.2g of 5dff/g polyethylene powder and decanone 200+nj2 are placed in a separable flask equipped with a condenser. At this time, 0.042g of 3.5-di-tert-butyl-4-hydroxytoluene is added as a process stabilizer. After that, while stirring, the temperature of the system was maintained at room temperature, and nitrogen gas was bubbled for 30 minutes to remove oxygen dissolved in the system, and subsequent operations were performed under a nitrogen gas seal. Furthermore, the temperature of the system was raised to 1) 0°C and stirred for 20 minutes to moisten the powder, further heated to 150°C and continued stirring for 1 hour,
A uniform solution of ultra-high molecular weight polypropylene-polyethylene composition was obtained.

This (gNii) was transferred to a plunger type extruder equipped with a 2 mmφ nozzle kept at 150°C, and after standing for 1 hour, the solution was extruded.
It was taken to room temperature under an air gap of 0 cm, then introduced into an acetone bath, and subjected to a crystallization operation to obtain a crystallized fiber. At this time, the liquid was taken up in a state close to free fall, and no active drafting was performed. This crystallized fiber was wound onto a bobbin, dried under reduced pressure at room temperature, and subjected to a drawing process.

The fibers prepared by the method described above were drawn under the following conditions.

Four Godets rolls were installed between each roll, and a stretching tank (continuous stretching was carried out with an effective width of 50 cn+l) containing Flusol P (thermal medium manufactured by Thermal Kagaku Sangyo ■).The stretching conditions were as follows:
5 times at 120°C in the first drawn layer, 145 times in the second drawn layer
The film was stretched 30 times at 170° C., and 585 times at 170° C. in the third stretching layer.

Note that the rotation speed of the first godet roll was 0.5 m/min, and the desired stretching ratio was obtained by changing the rotation speed of the second and subsequent godet rolls. Table 1 shows the breaking strength, tensile modulus, breaking elongation, and output energy amount of this fiber.

The breaking strength, tensile modulus, breaking elongation, and output energy in the present invention were measured at 23° C. using a Tensilon tensile tester U-1) 60 manufactured by Orientic. At this time, the sample length between the clamps was 20III1), and the tensile speed was 20 mm.
/ minute. However, the tensile modulus was calculated using the initial modulus of elasticity and the slope of the tangent. In addition, the fiber cross-sectional area required for calculation is based on the fiber density of 0.910 g/c1)3,
It was calculated from the weight of the sample.

Compared to the results of Example 1, the elastic modulus is high, but the strength and elongation are low, so even though the molecular weight is high, the output energy amount is low.

Comparative Example 2 Intrinsic viscosity [η] is 19. 20 gr of ultra-high molecular weight polypropylene powder with oa Q,/g and paraffin wax, Z, f LUVAX-1266 molecular weight 460:
Using 200mmφ screw type extrusion i (L/D=26) with 800g of Japanese fine wax ■'W), the resin temperature was 21.
A mixed composition was prepared by extrusion at 0°C. At this time, as a process stabilizer, 3,5-di-tert-butyl-4-hydroxytoluene and tetrakis[methylene-3(3,5-di-tert-butyl-4-hydroxyphenylene)propionate 1methane were added to the polymer per-polypropylene. 0.1% by weight was added.

Using the ultra-high molecular weight polypropylene composition prepared as described above as a preventive stock solution, the melt was spun under the following conditions to obtain a yarn.

That is, 21) The above spinning dope was extruded at a resin temperature of 200° C. using a plunger type extruder equipped with a IIIφ spinning nozzle.

The extruded melt was wound around a bobbin at a draft ratio of 18 in air at 25° C. under an air gap of 70 cm to form a raw yarn.

The raw yarn prepared as described above was continuously stretched using five godet rolls and four drawing tanks (effective width 50 cm1) installed between each godet roll to obtain a drawn product. 1 Godet roll rotation speed 2
5 am/min, the rotational speed of the second godetroll to 175 cm/win, the rotational speed of the third godetroll to 200 cm/n+in, the rotational speed of the fourth godetroll to 253 cm/min, and the rotation of the fifth godetroll. The speed was set to 320 cm/min, and the total stretching ratio was set to 12.8 times by four stages of stretching.

In addition, n-decane at 100°C was placed in the first drawing tank, n-decane at 120°C was placed in the second drawing tank, and n-decane at 140°C was placed in the third drawing tank.
Flusol P at 0° C. was used as a heating medium, and Flusol P at 160° C. was used as a heating medium in the fourth stretching tank.

Here, the total stretching ratio is determined by the rotational speed ratio of the fifth godet roll and the first godet roll.

The breaking strength, tensile modulus, breaking elongation, and output energy amount of this fiber are listed in Table-1.

Comparative Example 3 3.0 gr of ultra-high molecular weight polypropylene powder with an intrinsic viscosity [Q] of 19.30 d9/g and p-xylene (
Distilled product) 3000mff is placed in a separable flask equipped with a condenser. At this time, 0.03 gr of 3,5-di-tert-butyl-4-hydroxytoluene was simultaneously added as a process stabilizer. Thereafter, while stirring, the temperature of the system was maintained at room temperature, nitrogen gas was bubbled for 30 minutes to remove oxygen dissolved in the system, and subsequent operations were performed under a nitrogen gas blanket. Set the temperature of the system to 135
The temperature was raised to 0.degree. C. and stirring was continued for 1 hour to obtain a homogeneous ultra-high molecular weight polypropylene solution. Then, stirring was stopped and the mixture was allowed to cool down to 25° C. and allowed to stand still. Then, the temperature was gently raised to 130°C and left standing for 10 minutes. Then, it is placed in a constant temperature bath at 55° C. and allowed to stand for 20 hours for isothermal crystallization.

The p-xylene solution containing the single crystal of ultra-high molecular weight polypropylene prepared as described above is filtered by suction using an aspirator by placing a filter paper on a mesh filter. After filtration, a sheet of filter paper is placed on top of the filtrate, a weight is placed on top of the filtrate, and the filter is dried under reduced pressure at room temperature for 3 days.

In this way, a single crystal mat with a thickness of 0.1)0 mm was obtained.

The above single crystal mat was cut to a width of 41) IffI, sandwiched between two polyethylene billets with a diameter of 10 mm, and a plunger type extruder (cylinder diameter 10 ram
φ) and maintained at 125° C. for 10 minutes, and then extruded in a pseudo-melt state at an extrusion speed of 1 mm/min to in-phase stretch approximately 6 times.

Next, the polyethylene billet stretched in the same phase was divided into two, the polypropylene stretched product was taken out, and the air oven was preheated to 165 mm using a tensile tester equipped with an air oven (manufactured by Naji Seisakusho) with a distance between chucks of 20 cm.
℃, attach the sample, and immediately
The film was stretched to a total stretching rate of 72 times (gi ratio) at a speed of m/min.

The breaking strength, tensile modulus, breaking elongation, and output energy amount of this fiber are listed in Table 1.

As is clear from the table, the breaking strength and tensile modulus are sufficiently large, but the output energy amount is small because the breaking elongation is small.

Comparative Example 4 A propylene polymer having an intrinsic viscosity [n] of 3.17 dff/g was extruded at a resin temperature of 290° C. using a plunger type extruder equipped with a spinning nozzle of 2.0 mmφ. The extruded melt was wound around a bobbin in air at 25° C. under an air gap of 80 cm at a draft ratio of 97 to obtain a raw yarn. In addition, as a process stabilizer, 3.5
-di-tert-butyl-4-hydroxytoluene and tetrakis[methylene-3(3,5-di-tert-butyl-4-hydroxytoluene)
-Butyl-4-hydroxyphenylene)propione-
)-] methane to high molecular weight polypropylene
It was used by adding % by weight.

This raw yarn was drawn in a drawing tank (effective width: 50 mm
cm). Stretching conditions are 150℃
It was stretched 080 times.

In addition, the rotation speed of the first godet roll is 25 cm/min, the rotation speed of the second godet roll is 250, and Ocn+
/llll1n.

Here, the stretching ratio is determined by the rotational speed ratio of the second godet roll and the first godet roll.

Table 1 shows the breaking strength, tensile modulus, breaking elongation, and output energy amount of the fibers.

[Effects of the Invention] According to the present invention, the crystal structure of the raw yarn is adjusted during spinning, and the raw yarn is heated and then stretched, thereby achieving high strength and high elongation at break. , it is possible to produce a stretched propylene polymer with a large amount of output energy, and this stretched propylene polymer has a breaking strength of 50%
Because the amount of output energy after 10 load repetitions is large, it is widely used as a material for energy regeneration elastic bodies such as airbags, mooring lobes, mooring ropes such as tow ropes, and reinforcing fibers for reinforced plastics. It can be used for various purposes.

[Brief explanation of the drawing]

FIG. 1 is an X-ray interferogram of the propylene polymer yarn according to the present invention, FIG. 2 is a graph showing the relationship between the draft ratio and crystal orientation ratio of the propylene polymer yarn according to the present invention, and FIG. 4 is a graph showing the relationship between the draft ratio of the propylene polymer yarn according to the present invention and the output energy amount of the drawn product. FIG. FIG. 5 is a graph showing the relationship between molecular mold and output energy amount of the propylene polymer according to the present invention. Patent applicant: Mitsui Petrochemical Industries, Ltd. 9-turn angle nest diagram

Claims (2)

[Claims] (1) Breaking strength is 0.7 GPa or more, breaking elongation is 20%
The elastic modulus is 4.0 GPa or more, and the breaking strength is 5.
Output energy amount after 10 repetitions of 0% load is 3.0
kgfm/g or more, and has an intrinsic viscosity [η] of at least 3.5 dl/g or more, the drawn product is a stretched product mainly composed of a propylene polymer having an intrinsic viscosity [η] of at least 3.5 dl/g. The crystal orientation ratio (C-axis crystal orientation strength/a'-axis crystal orientation strength) between the C-axis crystal orientation in the raw yarn and the a'-axis crystal orientation measured by line diffraction method is 1.2 or more. 1. A stretched propylene polymer, which is obtained by spinning the yarn under draft and then post-stretching the yarn at a stretching ratio of 2 to 50 times. (2) When melt spinning a propylene polymer having an intrinsic viscosity [η] of at least 3.5 dl/g, the C-axis crystal orientation and a'-axis crystal orientation in the raw yarn measured by X-ray diffraction method The yarn is spun with a draft so that the crystal orientation ratio (C-axis crystal orientation strength/a'-axis crystal orientation strength) is 1.2 or more, and then this raw yarn is drawn at a stretching ratio of 2 to 50 times. Characterized by post-stretching, breaking strength is 0.7G
Pa or more, breaking elongation is 20% or more, elastic modulus is 4.0GP
A method for producing a stretched propylene polymer having an output energy amount of 3.0 kgfm/g or more after 10 repetitions of a load of 50% of the breaking strength.