JPH075667B2 - High-strength, high-modulus polyethylene material manufacturing method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing a polyethylene material (fiber, film, etc.) having a high strength and a high elastic modulus, and more particularly, combining a specific catalyst with a specific polymerization method. The present invention relates to a method for producing a high-strength, high-modulus polyethylene material by stretching the ultrahigh molecular weight polyethylene powder obtained by the above under specific conditions.

Conventional technology and problems to be solved by the invention So-called ultra-high-molecular-weight polyethylene, which has a remarkably high molecular weight of approximately 1 million or more, is an engineering plastic characterized by its excellent impact resistance, abrasion resistance, and self-lubricating properties. It is used in a wide range of fields such as food machinery such as hoppers, silos, various gears, lining materials, ski linings, civil engineering machinery, chemical machinery, agriculture, mining, sports and leisure.

Since ultra-high molecular weight polyethylene has a much higher molecular weight than general-purpose polyethylene, if it can be highly oriented, a stretched product with higher strength and elasticity than ever before can be obtained. Various studies have been made. However, since ultrahigh molecular weight polyethylene has an extremely high melt viscosity as compared with general-purpose polyethylene, it is almost impossible to perform extrusion molding by a usual method, and it is not possible to stretch it for high orientation.

Paul Smith, Peter Yarn Lemstra, et al., A method in which a gel obtained from a decalin solution (dope) of ultrahigh molecular weight polyethylene can be stretched at a high ratio to produce a fiber having high strength and high elastic modulus (JP-A-56) -15408) is proposed. The polymer concentration in the dope was 1.5 × 10 ^{6 with} a weight average molecular weight.
3% by weight of 4x10 ⁶ was carried out at an extremely low concentration of 1% by weight, and in practical use a large amount of solvent was used, and a method for producing and handling a highly viscous solution It is extremely disadvantageous in terms of economy.

In order to overcome the above-mentioned problems, there are various proposals for a method of highly stretching and highly orienting ultrahigh molecular weight polyethylene by a method such as extrusion, stretching or rolling below its melting point [JP-A-59]. -187614, JP-A-60-15120
No. 60-97836, Proc. Of the Japan Society of Polymer Science, Vol. 34, No. 87.
Page 3 (1985) etc.].

However, in the conventionally known method, ultrahigh molecular weight polyethylene is previously made into a dilute solution of a solvent such as xylene, decalin, and kerosene, and then solid phase extrusion or stretching is performed using a single crystal mat obtained by cooling or isothermal crystallization. However, this method has not solved the problem that a large amount of solvent must be used when producing a single crystal mat.

On the other hand, although it is possible to perform solid phase extrusion and stretching of ultrahigh molecular weight polyethylene as it is without using a single crystal mat, the pressure at the time of extrusion is extremely high and the extrusion rate is low and the stretching ratio is also high in the commonly used one-stage polymerized products. I can't raise
The strength and elastic modulus of the obtained molded product were low, and improvement was desired.

Means for Solving Problems From the above, the present inventors have conducted extensive studies to solve these problems, and as a result, an ultrahigh molecular weight polyethylene powder obtained by combining a specific catalyst and a specific polymerization method. The present invention has been completed by finding that a polyethylene material having high strength and high elastic modulus can be produced by stretching the polyethylene in a solid state.

That is, the present invention provides an ultra high molecular weight polyethylene powder having an intrinsic viscosity of 5 to 50 dl / g, preferably 5 to 30 dl / g in decalin at 135 ° C. and obtained by at least the following two-step polymerization reaction. The present invention relates to a method for producing a high-strength, high-modulus polyethylene material by stretching at a temperature below the melting point of polyethylene.

(First stage) Ethylene is polymerized in the absence of hydrogen or at a reduced hydrogen concentration by a catalyst composed of a solid catalyst component containing at least Mg, Ti and / or V and an organoaluminum compound, at 135 ° C. in decalin Has an intrinsic viscosity of 12 to 50d
A step of producing 50 to 99.5 parts by weight of l / g polyethylene.

(Second stage) A step of producing 50 to 0.5 parts by weight of polyethylene by polymerizing ethylene under the hydrogen concentration increased from the first stage.

Effects of the Invention The ultrahigh molecular weight polyethylene powder used in the method of the present invention has the following effects (features).

(1) Since it is excellent in processability, it can be stretched at a high ratio, and a polyethylene material (fiber, film, etc.) having high strength and high elasticity can be manufactured very stably.

(2) Since it is excellent in processability, it can be drawn with less power and high speed, and it can be economically manufactured by including fibers and films having high strength and high elastic modulus.

A more specific method for producing the ultrahigh molecular weight polyethylene powder used in the present invention will be described below.

First, in the first stage, ethylene is polymerized in a solvent or in a gas phase at a hydrogen concentration of 0 to about 10 mol%,
50 to 99.5 parts by weight, preferably 70 to 99 parts by weight of polyethylene having an intrinsic viscosity of 12 to 50 dl / g, preferably 12 to 32 dl / g in decalin at 5 ° C is produced.

The polymerization catalyst used at this time is a solid catalyst component containing at least Mg, Ti and / V and an organometallic compound (described later), the polymerization pressure is 0 to 70 Kg / cm ² · G, and the polymerization temperature is polyethylene. Temperatures below the melting point of
~ 110 ° C, preferably 0-90 ° C, more preferably 20-80
Carry out at ° C. As the polymerization solvent, an organic solvent inert to the Ziegler type catalyst is used. Specific examples thereof include saturated hydrocarbons such as butane, pentane, hexane, heptane, octane, and cyclohexane, and aromatic hydrocarbons such as benzene, toluene, xylene, and the like, and molding processing of the resulting ultrahigh molecular weight polyethylene. If necessary, a high-boiling organic solvent such as decalin, tetralin, decane, or kerosene can be used.

Then, in the second stage, the hydrogen concentration is adjusted to 35 to 95 mol%,
Subsequent polymerization of ethylene produces 50 to 0.5 parts by weight of polyethylene, preferably 30 to 1 parts by weight. Polymerization pressure is 0 ~ 70Kg / cm ² · G, temperature is 40 ~ 100 ℃,
The temperature is preferably 60 to 90 ° C, and the catalyst may be added if necessary. The intrinsic viscosity of the polyethylene produced in the second step is in the range of about 0.1 to 4.9 dl / g (135 ° C, in decalin).

Copolymerization of an α-olefin other than ethylene as a comonomer is not preferable because it tends to cause a decrease in the molecular weight of the produced polymer, but it is not preferred that 0.1-
It does not matter if a small amount of 5 mol% of α-olefin is used. The α-olefin at this time includes propylene, butene-1, 4-methylpentene-1, hexane-
The ones used for copolymerization of ethylene with a general Ziegler type catalyst such as 1, octene-1 can be used.

Further, as a process after the third stage, it is acceptable to appropriately add a higher molecular weight polymer component or a lower molecular weight polymer component.

Next, the catalyst used for producing the ultra-high molecular weight polyethylene powder of the present invention comprises a fixed catalyst component containing at least Mg, Ti and / or V and an organoaluminum compound.

Here, the solid catalyst component is obtained by supporting a titanium compound on an inorganic solid compound containing magnesium by a known method.

The inorganic solid compound containing magnesium is metallic magnesium, magnesium hydroxide, magnesium carbonate, magnesium oxide, magnesium chloride, etc., and a double salt containing a metal and a magnesium atom selected from silicon, aluminum, and calcium, a complex oxide, Carbonates, chlorides, hydroxides, and other inorganic solid compounds are added to water, alcohols, phenols, ketones, aldehydes, carboxylic acids, esters, polysiloxanes, acid amides, and other organic oxygen-containing compounds; metal alkoxides, Inorganic oxygen-containing compounds such as metal oxyacid salts; Organic sulfur-containing compounds such as thiols and thioethers; Inorganic sulfur-containing compounds such as sulfur dioxide, sulfur trioxide, sulfur; Benzene, toluene, xylene, anthracene, phenanthrene, etc. Monocyclic and polycyclic Aromatic hydrocarbon compounds; chlorine, hydrogen chloride, metal chlorides, is obtained by treatment or reaction with a halogen-containing compounds such as organic halides.

Examples of the titanium compound supported on the inorganic solid compound include titanium halides, alkoxy halides,
Examples of tetravalent or trivalent titanium compounds such as alkoxides and halogenated oxides include Ti (OR) nX ₄ -n (wherein R is an alkyl group having 1 to 20 carbon atoms, An aryl group or an aralkyl group, X represents a halogen atom, and n is 0 ≦ n ≦ 4), and is preferably titanium tetrachloride, titanium tetrabromide, titanium tetraiodide, monomethoxy. Trichloro titanium, dimethoxy dichloro titanium, trimethoxy monochloro titanium, tetramethoxy titanium, monoethoxy trichloro titanium, diethoxy dichloro titanium, triethoxy monochloro titanium, tetraethoxy titanium, monoisopropoxy trichloro titanium,
Diisopropoxydichlorotitanium, triisopropoxymonochlorotitanium, tetraisopropoxytitanium, monobutoxytrichlorotitanium, dibutoxydichlorotitanium, monopentoxytrichlorotitanium, monophenoxytrichlorotitanium, diphenoxydichlorotitanium, triphenoxymonochlorotitanium, tetraphenoxy. Examples include tetravalent titanium compounds such as titanium. The trivalent titanium compound is a trivalent titanium compound obtained by reducing titanium tetrahalide such as titanium tetrachloride or titanium tetrabromide with hydrogen, aluminum, titanium or an organometallic compound of Group I to III metal of the periodic table. valent titanium compound; the general formula Ti (oR) mX ₄ -m (wherein, R represents an alkyl group, an aryl group or an aralkyl group, having 1 to 20 carbon atoms, X is a halogen atom, m is 0 < m <4) and a trivalent titanium compound obtained by reducing a tetravalent halogenated alkoxytitanium represented by the formula (I) with an organometallic compound of a metal of Group I to III of the periodic table. Of these titanium compounds, tetravalent titanium compounds are particularly preferable. As the vanadium compound, a tetravalent vanadium compound such as vanadium tetrachloride, a vanadium oxytrichloride, a pentavalent vanadium compound such as orthoalkylvanadate, and a trivalent vanadium compound such as vanadium trichloride. Is mentioned. Specific solid catalyst components include JP-B-51-3514, JP-B-50-23864, JP-B-51-152, JP-B-52-15111, JP-A-49-106581, Japanese Examiner 5
2-11710, JP-B-51-153, JP-A-56-95909
Those specifically disclosed in Japanese Patent Publications and the like are listed.

Further, as the other solid catalyst component, for example, a reaction product of a Grignard compound and a titanium compound can also be used. JP-B-50-39470, JP-B-54-12953, JP-B-54-1
2954, those specifically described in JP-A-57-79009 and the like, in addition, JP-A-56-47407,
It is also possible to use a solid catalyst component in which an inorganic oxide is used in combination with the optionally used organic carboxylic acid ester described in JP-A-57-187305 and JP-A-58-21405.

Examples of the organoaluminum compound of the present invention include general formulas R ₃ Al, R ₂ AlX, RAlX ₃ , R ₂ AlOR, RAl (OR) X and R ₃ Al ₂ X ₃ (where R is an alkyl group having 1 to 20 carbon atoms). Group, an aryl group or an aralkyl group, X represents a halogen atom, R
May be the same or different. ) Is preferable, and triethyl aluminum, triisobutyl aluminum, trihexyl aluminum, trioctyl aluminum, diethyl aluminum chloride, diethyl aluminum ethoxide, ethyl aluminum sesquichloride, and a mixture thereof can be mentioned. The amount of the organoaluminum compound used is not particularly limited, but is usually 0.1 to the titanium compound.
~ 1000 molar times can be used.

The above catalyst system is used to synthesize the ultrahigh molecular weight polyethylene powder of the present invention.

Prior to the polymerization reaction of the present invention, the α-olefin and the catalyst system of the present invention are brought into contact with each other, and then the polymerization reaction is carried out, whereby the polymerization reaction can be carried out more stably than in the untreated case.

The term "melting point of polyethylene" used in the present invention refers to the differential scanning calorimetry (DSC, heating rate 5) without subjecting the ultra-high molecular weight polyethylene powder obtained as described above to a heat treatment.
° C / min, maximum melting point (main peak temperature) with sample amount 4-5 mg).

Further, in the present invention, it is important to use the obtained ultra high molecular weight polyethylene as it is, and the effect of the present invention cannot be obtained if it is heated and melted once.

The stretching can be performed by a conventional method such as extrusion stretching and tensile stretching. However, in order to obtain a stretched product having a higher stretch ratio and a tensile elastic modulus, it is preferable to perform a two-stage stretching in which extrusion stretching is performed and then tensile stretching is performed.

Examples of extrusion stretching include solid phase extrusion and roll rolling.

As the solid phase extrusion, for example, the above-mentioned ultra high molecular weight polyethylene powder is put into a cylinder of a solid phase extruder equipped with a die at the bottom, and the temperature is 20 ° C. or higher and lower than the melting point of the ultra high molecular weight polyethylene powder, preferably 90 ° C. or higher, After prepressurizing at a temperature lower than the melting point of the ultra high molecular weight polyethylene powder at a pressure of 0.01 to 0.1 GPa, 20 ° C. or higher, lower than the melting point of the ultra high molecular weight polyethylene powder, preferably 90 ° C. or higher, the melting point of the ultra high molecular weight polyethylene powder. The method of extruding less than 1 is mentioned. The draw ratio (extrusion ratio) depends on the molecular weight of the polymer, the first stage and the second
It depends on the polymerization amount (composition ratio) of the step, but it can be arbitrarily selected by changing the die diameter, usually 2 to 100 times,
It is preferably carried out at 3 to 50 times, more preferably 3 to 25 times.

Also in the case of roll rolling, it can be carried out according to a conventional method within the same temperature range as in solid phase extrusion.

Examples of the tensile stretching performed after the extrusion stretching include nip stretching and roll stretching. Of these, nip stretching is more preferable.

The temperature in the tensile drawing is 20 ° C. or higher and lower than the melting point of the ultra high molecular weight polyethylene powder, preferably 90 ° C. or higher and lower than the melting point of the ultra high molecular weight polyethylene powder.

The pulling speed varies depending on the molecular weight and composition ratio of the polymer, but is 1 to 100 mm / min, preferably 5 to 50 mm / min.

The higher the draw ratio, the higher the strength and the high elastic modulus that can be achieved. Therefore, it is desirable to increase the draw ratio as much as possible. However, the ultrahigh molecular weight polyethylene of the present invention can be drawn at 20 to 60 times.

A fiber or film having a tensile elastic modulus of 120 GPa or more and a strength of 2 GPa or more can be obtained by the above stretching method.

Hereinafter, the present invention will be specifically described in detail with reference to Examples, but the present invention is not limited thereto.

Examples Example 1 (a) Preparation of solid catalyst component Two stainless steel balls having a 1/2 inch diameter were used.
Commercially available anhydrous magnesium chloride (10 g) and aluminum ethoxide (1.7 g) were placed in a stainless steel pot with an internal volume of 5 ml containing 400 g, and ball milling was performed at room temperature for 5 hours in a nitrogen atmosphere. Ball milling was performed for 16 hours. 1 g of the solid catalyst component obtained after ball milling contained 39 mg of titanium.

(B) Polymerization A 2-liter stainless steel autoclave equipped with an induction stirrer was replaced with nitrogen, 1000 ml of hexane was added, 1 mmol of triethylaluminum and 10 mg of the solid catalyst component were added, and the temperature was raised to 60 ° C. with stirring. Hexa vapor pressure causes the system to reach a pressure of 1.5 kg / cm ² · gauge pressure (hereinafter referred to as Kg / cm ² · G), but ethylene is injected until the total pressure reaches 10 kg / cm ² · G. Started. Total pressure of the autoclave from ethylene metering tank 5l is continuously introduced ethylene to be 10Kg / cm ² · G, the pressure in the metering vessel and polymerization was carried out until the reduced 7 Kg / cm ² min (first phase ).

At this time, the intrinsic viscosity [η] of the polymer was 18.9 dl / g.
Ethylene was purged thereafter quickly in the system, initiate Harikon by polymerization again at 60 ° C. until a total pressure of the imposition followed ethylene until the total pressure of hydrogen is 7Kg / cm ² · G becomes 10Kg / cm ² · G did. Ethylene was continuously introduced so that the total pressure was 10 kg / cm ² · G, and the polymerization was carried out until the pressure in the measuring tank decreased by 3 kg / cm ² (second step).

After completion of the polymerization, the polymer slurry was transferred to a beaker and hexane was removed under reduced pressure to obtain 62 g of white polyethylene. The amount of polymer produced in the first stage was 70 parts by weight, the amount of polymer produced in the second stage was 30 parts by weight, and the intrinsic viscosity [η] of the entire polymer was
It was 11.7 dl / g (135 ° C in decalin).

(C) Solid-phase extrusion and tensile stretching In a newly modified Instron capillary rheometer (cylinder inner diameter 0.9525 cm), inner diameter 0.39 cm, length
Attach a 1 cm die and weigh about 10 g of the polymer obtained in (b).
Filled. After compressing at 90 ° C. under a pressure of 0.01 GPa for 10 minutes, it was extruded at the same temperature at a constant rate of 0.06 cm / min. The deformation ratio (stretching ratio) was represented by the ratio of the cylinder cross-sectional area to the die cross-sectional area, and in this case was 6 times. The pressure during extrusion is shown in Table 1.

The extrudate thus obtained was measured by a tensile tester equipped with a thermostatic chamber for 120
It was possible to stretch 35 times by stretching at a crosshead speed of 40 mm / min.

The elastic modulus and strength of the obtained stretched product were measured according to a conventional method. The results are shown in Table 1.

Comparative Example 1 A 2-liter stainless steel autoclave equipped with an induction stirrer was replaced with nitrogen, 1000 ml of hexane was added, 1 mmol of triethylaluminum and 10 mg of the solid catalyst component obtained in Example 1 (a) were added, and the temperature was raised to 60 ° C. with stirring. Warmed.
Becomes 1.5Kg / cm ² · G in the vapor pressure of hexane was initiate polymerization by Harikon until the total pressure of ethylene is 10Kg / cm ² · G. Ethylene was continuously introduced so that the total pressure would be 10 kg / cm ² · G, and polymerization was carried out for 20 minutes to obtain 72 g of white polyethylene. The intrinsic viscosity [η] was 18.5 dl / g.

When this polymer was subjected to solid phase extrusion according to Example 1 (c), it was extruded at a deformation ratio of 4 times. Then, when tensile stretching was performed, it was possible to stretch 22 times. The elastic modulus and strength of the obtained stretched product are shown in Table 1. Compared with Example 1, the elastic modulus was low and the extrusion pressure was extremely high.

Comparative Example 2 White polyethylene 92 was polymerized in the same manner as in Comparative Example 1 except that the polymerization temperature in Comparative Example 1 was 85 ° C.
got g. The intrinsic viscosity [η] was 11.5 dl / g.

This polymer was solid-phase extruded 6 times according to Example 1 (c), and then stretched and stretched. The draw ratio was 13 times.

The elastic modulus and strength at this time are shown in Table 1.

Comparative Example 3 Similar to Example 1 (c) except that the polymer obtained in Example 1 (b) was compression molded at 200 ° C. and 0.02 GPa for 15 minutes. Went to.
The extrudate (stretching ratio 6 times) was further stretch-stretched, but only 2.5 times stretchable. The elastic modulus and strength of the drawn product are shown in Table 1.

Example 2 In Example 1 (b), the pressure reduction in the ethylene metering tank in the first stage polymerization was 9.0 kg / cm ² min, and in the second step polymerization the pressure reduction in the ethylene metering tank was 1.0 kg / cm ² min. Polymerization was performed in the same manner as in Example 1 (b) except that the above was used to obtain 63 g of white polyethylene. The amount of polymer produced in the first stage was 90 parts by weight, and the amount of polymer produced in the second stage was 10 parts.
By weight, the intrinsic viscosity [η] of the entire polymer is 15.1
It was dl / g.

This polymer was solid phase extruded (120) according to Example 1 (c).
℃, draw ratio 6 times) and tensile drawing (120 ℃, draw ratio 2
8 times). The elastic modulus and strength of the stretched product are shown in Table 1.

Example 3 In Example 1 (b), the pressure reduction in the ethylene metering tank in the first stage polymerization was set to 8.0 kg / cm ² min, and the pressure decrease in the ethylene metering tank in the second stage polymerization was 2.0 kg / cm ² min. Polymerization was carried out in the same manner as in Example 1 (b) except that the above was used to obtain 62 g of white polyethylene. The amount of polymer produced in the first stage is 80 parts by weight, and the amount of polymer produced in the second stage is 20.
The intrinsic viscosity [η] of the entire polymer is 13.0 dl.
It was / g.

This polymer was solid phase extruded (90 ° C, according to Example 1 (c))
Draw ratio 6 times) and tensile draw (120 ° C, draw ratio 32
Times). The elastic modulus and strength of the stretched product are shown in Table 1.

Example 4 (a) Production of solid catalyst component In Example 1 (a), aluminum triethoxide 1.
A solid contact component was prepared in the same manner as in Example 1 (a) except that 2.2 g of aluminum triethoxide and 3.2 g of silicon tetraethoxide were used instead of 7 g. 1 g of the obtained solid catalyst component contained 32 mg of titanium.

(B) Polymerization Using the same autoclave as in Example 1 (b), 1000 ml of hexane was added, 2 mmol of diethylaluminum chloride and 10 mg of the solid catalyst component were added, and the temperature was raised to 40 ° C with stirring. Hexane vapor pressure of 1.3 kg / cm ² · G
However, ethylene was introduced until the total pressure reached 10 kg / cm ² · G to start the polymerization. Ethylene was continuously introduced from a 5 liter ethylene metering tank so that the total pressure in the autoclave was 10 kg / cm ² · G, and polymerization was carried out until the pressure in the metering tank decreased by 6 kg / cm ² (first step). ).

The intrinsic viscosity [η] of this type of polymer was 26.1 dl / g.

After that, quickly purge ethylene in the system and raise the temperature to 80 ° C.
The temperature was raised to 8 Kg / cm ² · G, and then ethylene was added until the total pressure reached 10 Kg / cm ² · G to start the polymerization again. It was continuously introduced so that the total pressure would be 10 kg / cm ² · G, and the polymerization was carried out until the pressure in the measuring tank decreased by 4 kg / cm ² (second step).

After the polymerization was completed, the polymer slurry was transferred to a beaker and hexane was removed under reduced pressure to obtain 62 g of white polyethylene.

The amount of polymer produced in the first stage was 60 parts by weight, the amount of polymer produced in the second stage was 40 parts by weight, and the intrinsic viscosity [η] of the entire polymer was 12.2 dl / g.

This polymer was solid phase extruded (90 ° C, according to Example 1 (c))
Draw ratio 6 times) and tensile draw (120 ° C, draw ratio 32
Times). The elastic modulus and strength of the stretched product are shown in Table 1.

Example 5 (a) Production of solid catalyst component VO in place of 2.0 g of titanium tetrachloride in Example 1 (a)
A solid catalyst component was prepared in the same manner as in Example 1 (a) except that 0.5 g of (OC ₂ H ₅ ) ₃ and 2.0 g of titanium tetrachloride were used. 1 g of the obtained solid catalyst component contained 7.6 mg of vanadium and 30.6 mg of titanium.

(B) Polymerization Using the same autoclave as in Example 1 (a), 1000 ml of hexane was added, 1 mmol of triethylaluminum and 10 mg of the solid catalyst component were added, and the mixture was stirred at 60 ° C.
The temperature was raised to. Hexane become 1.5Kg / cm ² · G in the vapor pressure of, but the polymerization was initiated by Harikon until the ethylene total pressure 10Kg / cm ² · G. Total pressure of the autoclave from ethylene metering tank 5l is continuously introduced ethylene to be 10Kg / cm ² · G, the pressure in the metering vessel and polymerization was carried out until the reduced 7 Kg / cm ² min (first phase ).

At this time, the intrinsic viscosity [η] of the polymer was 20.5 dl / g.

After that, ethylene in the system was quickly purged, and hydrogen at 7 kg /
cm ² · G, and then ethylene is applied at a total pressure of 10 kg / cm ² ·
Polymerization was started again by adhering to G. Total pressure is 10
Continuously introduced such that Kg / cm ² · G, the pressure in the metering vessel and polymerization was carried out until the reduced 3 Kg / cm ² min (second step).

After the polymerization was completed, the polymer slurry was transferred to a beaker, and hexane was removed under reduced pressure to obtain 60 g of white polyethylene.

The amount of polymer produced in the first stage was 70 parts by weight, the amount of polymer produced in the second stage was 30 parts by weight, and the intrinsic viscosity [η] of the entire polymer was 13.8 dl / g.

This polymer was solid phase extruded (110) according to Example 1 (c).
℃, draw ratio 6 times) and tensile drawing (120 ℃, draw ratio 2
5 times). The elastic modulus and strength of the stretched product are shown in Table 1.

Example 6 A polymer having [η] 30.1 dl / g was obtained in the same manner as in Example 2 except that the polymerization temperature in the first step was 20 ° C. This polymer was subjected to solid phase extrusion (120 ° C., draw ratio 6 times) and tensile stretching (120 ° C., draw ratio 26 times) according to Example 1 (c). The elastic modulus and strength of the stretched product are shown in Table 1.
It was shown to.

Example 7 (a) Production of solid catalyst component A 300 ml three-necked flask equipped with a stirrer and a reflux condenser was replaced with nitrogen, and 4 g (1/6 mol) of metallic magnesium was taken.
It was vacuum dried at 50 ° C. for 1 hour. Then 23.6 g (1/6 mol) of SiCl ₄ was added and stirred to bring the system to 40 ° C., then EtOH 46.0 g
(1 mol) was added dropwise over 10 minutes. Et after dripping
An additional 50 ml of OH was added, the temperature of the oil bath was raised to 180 ° C., and the reaction was continued for another 3 hours. After completion of the reaction, 50 ml of cold hexane was added to deposit a precipitate, and unreacted SiCl ₄ , EtOH and hexane were removed under reduced pressure. Next, 50 ml of TiCl ₄ was added to the obtained white powder, and the temperature was 130 ° C.
And reacted for 1 hour. After completion of the reaction, washing was carried out with hexane, and the washing was repeated until TiCl ₄ was not observed in the washing liquid.
When the solid part was dried and analyzed, 43 mg of titanium was supported per 1 g of the solid.

(B) Polymerization A 2-liter stainless steel autoclave equipped with an induction stirrer was replaced with nitrogen, 1000 ml of hexane was added, 1 mmol of triethylaluminum and 15 mg of the solid catalyst component were added, and the temperature was raised to 60 ° C. with stirring. The vapor pressure of hexane causes the system to reach a pressure of 1.5 kg / cm ² · gauge (hereinafter referred to as kg / cm ² · G), but ethylene is added until the total pressure reaches 10 kg / cm ² · G for polymerization. Started. Ethylene was continuously introduced from a 5 l ethylene metering tank so that the total pressure of the autoclave was 10 kg / cm ² · G, and polymerization was carried out until the pressure of the metering tank decreased by 7 kg / cm ² (first step). ).

At this time, the intrinsic viscosity [η] of the polymer was 18.0 dl / g.
Then quickly purge ethylene in the system, inject hydrogen until the total pressure reaches 7 kg / cm ² · G, then inject ethylene until the total pressure reaches 10 kg / cm ² · G, and start the polymerization again at 60 ° C. did. Ethylene was continuously introduced so that the total pressure became 10 kg / cm ² · G, and the polymerization was carried out until the pressure in the measuring tank decreased by 3 kg / cm ² (second step).

After completion of the polymerization, the polymer slurry was transferred to a beaker and hexane was removed under reduced pressure to obtain 62 g of white polyethylene. The amount of polymer produced in the first stage was 70 parts by weight, the amount of polymer produced in the second stage was 30 parts by weight, and the intrinsic viscosity [η] of the entire polymer was
It was 11.2 dl / g (in decalin, 135 ° C).

(C) Solid-phase extrusion and tensile stretching In a newly modified Instron capillary rheometer (cylinder inner diameter 0.9525 cm), inner diameter 0.39 cm, length
Attach a 1 cm die and weigh about 10 g of the polymer obtained in (b).
Filled. After compressing at 90 ° C. under a pressure of 0.01 GPa for 10 minutes, it was extruded at the same temperature at a constant rate of 0.06 cm / min. The deformation ratio (stretching ratio) was represented by the ratio of the cylinder cross-sectional area to the die cross-sectional area, and in this case was 6 times.

The extrudate thus obtained was measured by a tensile tester equipped with a thermostatic chamber for 120
Stretching was carried out at a crosshead speed of 40 mm / min at 40 ° C and a 27-fold stretching was possible.

The elastic modulus and strength of the obtained stretched product were measured according to a conventional method. The results are shown in Table 2.

Example 8 (a) Preparation of solid catalyst component Two stainless steel balls having a 1/2 inch diameter are used.
Anhydrous magnesium chloride 10.0g and aluminum triethoxide 4.3g were put into a stainless steel pot with an internal volume of 400ml containing 5 pieces, and ball milling was performed at room temperature for 5 hours in a nitrogen atmosphere, and then diethoxychlorotitanium 2.
7 g was added, and ball milling was further performed for 10 hours. 1 g of the solid catalyst component obtained after ball milling contained 36 mg of titanium.

(B) Polymerization A 2-liter stainless steel autoclave equipped with an induction stirrer was replaced with nitrogen, 1000 ml of hexane was added, 1 mmol of triethylaluminum and 10 mg of the solid catalyst component were added, and the temperature was raised to 60 ° C. with stirring. The vapor pressure of hexane causes the system to reach a pressure of 1.5 kg / cm ² · gauge (hereinafter referred to as kg / cm ² · G), but ethylene is added until the total pressure reaches 10 kg / cm ² · G for polymerization. Started. Ethylene was continuously introduced from a 5 l ethylene metering tank so that the total pressure of the autoclave was 10 kg / cm ² · G, and polymerization was carried out until the pressure of the metering tank decreased by 7 kg / cm ² (first step). ).

At this time, the intrinsic viscosity [η] of the polymer was 19.2 dl / g.
Then quickly purge ethylene in the system, inject hydrogen until the total pressure reaches 7 kg / cm ² · G, then inject ethylene until the total pressure reaches 10 kg / cm ² · G, and start the polymerization again at 60 ° C. did. Ethylene was continuously introduced so that the total pressure became 10 kg / cm ² · G, and the polymerization was carried out until the pressure in the measuring tank decreased by 3 kg / cm ² (second step).

After completion of the polymerization, the polymer slurry was transferred to a beaker and hexane was removed under reduced pressure to obtain 63 g of white polyethylene. The amount of polymer produced in the first stage was 70 parts by weight, the amount of polymer produced in the second stage was 30 parts by weight, and the intrinsic viscosity [η] of the entire polymer was
12.2 dl / g decalin at 135 ° C).

(C) Solid Phase Extrusion and Tensile Stretching Solid phase extrusion and tensile stretching were performed in the same manner as in Example 7. The results are shown in Table 2.

Example 9 (a) Production of solid catalyst component Commercially available anhydrous magnesium chloride (purity 99.9%) 9.5 g (0.
1 mol), 4.1 g (0.025 mol) of aluminum triethoxide, and 2.1 g of titanium trichloride (TACB manufactured by Toho Titanium).
2 stainless steel balls with 1/2 inch diameter
The mixture was put into a stainless steel pot having an internal volume of 400 ml containing 5 pieces, and ball milling was performed at room temperature for 16 hours in a nitrogen atmosphere. After ball milling, 1 g of the obtained solid powder contained 30 mg of titanium.

(B) Polymerization A 2-liter stainless steel derivative autoclave equipped with a stirrer was purged with nitrogen, and 1000 ml of hexane was added thereto.
Was added and the temperature was raised to 60 ° C. with stirring. The vapor pressure of hexane causes the system to reach a pressure of 1.5 kg / cm ² · gauge (hereinafter referred to as kg / cm ² · G), but ethylene is added until the total pressure reaches 10 kg / cm ² · G for polymerization. Started. Ethylene was continuously introduced from a 5 l ethylene metering tank so that the total pressure of the autoclave was 10 kg / cm ² · G, and polymerization was carried out until the pressure of the metering tank decreased by 7 kg / cm ² (first step). ).

At this time, the intrinsic viscosity [η] of the polymer was 18.7 dl / g.
Then quickly purge ethylene in the system, inject hydrogen until the total pressure reaches 7 kg / cm ² · G, then inject ethylene until the total pressure reaches 10 kg / cm ² · G, and start the polymerization again at 60 ° C. did. Ethylene was continuously introduced so that the total pressure became 10 kg / cm ² · G, and the polymerization was carried out until the pressure in the measuring tank decreased by 3 kg / cm ² (second step).

After completion of the polymerization, the polymer slurry was transferred to a beaker and hexane was removed under reduced pressure to obtain 63 g of white polyethylene. The amount of polymer produced in the first stage was 70 parts by weight, the amount of polymer produced in the second stage was 30 parts by weight, and the intrinsic viscosity [η] of the entire polymer was
It was 11.5 dl / g (in decalin, 135 ° C).

(C) Solid Phase Extrusion and Tensile Stretching Solid phase extrusion and tensile stretching were performed in the same manner as in Example 7. The results are shown in Table 2.

Example 10 (a) Production of solid catalyst component 10 g of commercially available anhydrous magnesium chloride was taken and dried at 150 ° C. for 2 hours. 40 ml of ethanol and aluminum trise
After adding 5.9 g of c-butoxide, the solution was heated to 200 ° C. to obtain a uniform solution. After mixing and heating at 200 ° C. for 2 hours to cause reaction, 100 ml of n-hexane was added to cause precipitation, and the supernatant was removed. The solvent was then removed under reduced pressure to give a white dry solid. Next, after adding 40 ml of vanadium tetrachloride and reacting at 150 ° C for 1 hour with stirring, excess vanadium tetrachloride was removed by decantation, and then washed with n-hexane until no vanadium tetrachloride was observed in the washing liquid. Repeated. The amount of titanium supported in the obtained solid catalyst was 1
It was 0.6 mg / g solid.

(B) Polymerization A 2-liter stainless steel autoclave equipped with an induction stirrer was replaced with nitrogen, 1000 ml of hexane was added, 1 mmol of triethylaluminum and 15 mg of the solid catalyst component were added, and the temperature was raised to 60 ° C. with stirring. The vapor pressure of hexane causes the system to reach a pressure of 1.5 kg / cm ² · gauge (hereinafter referred to as kg / cm ² · G), but ethylene is added until the total pressure reaches 10 kg / cm ² · G for polymerization. Started. Ethylene was continuously introduced from a 5 l ethylene metering tank so that the total pressure of the autoclave was 10 kg / cm ² · G, and polymerization was carried out until the pressure of the metering tank decreased by 7 kg / cm ² (first step). ).

The intrinsic viscosity [η] of the polymer at this time was 17.9 dl / g.
Then quickly purge ethylene in the system, inject hydrogen until the total pressure reaches 7 kg / cm ² · G, then inject ethylene until the total pressure reaches 10 kg / cm ² · G, and start the polymerization again at 60 ° C. did. Ethylene was continuously introduced so that the total pressure became 10 kg / cm ² · G, and the polymerization was carried out until the pressure in the measuring tank decreased by 3 kg / cm ² (second step).

After completion of the polymerization, the polymer slurry was transferred to a beaker and hexane was removed under reduced pressure to obtain 63 g of white polyethylene. The amount of polymer produced in the first stage was 70 parts by weight, the amount of polymer produced in the second stage was 30 parts by weight, and the intrinsic viscosity [η] of the entire polymer was
It was 10.8 dl / g (in decalin, 135 degreeC).

(C) Solid Phase Extrusion and Tensile Stretching Solid phase extrusion and tensile stretching were performed in the same manner as in Example 7. The results are shown in Table 2.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a flow chart of the present invention.

Continuation of front page (56) Reference JP 62-141006 (JP, A) JP 62-25105 (JP, A) JP 62-25106 (JP, A) JP 62-25107 (JP , A) JP 62-25108 (JP, A) JP 62-25109 (JP, A) JP 61-275313 (JP, A) JP 60-177008 (JP, A) JP 5-79683 (JP, B2)

Claims (1)

[Claims] 1. An intrinsic viscosity of 5 at 135 ° C. in decalin.
A method for producing a high-strength / high-modulus polyethylene material by stretching ultra-high molecular weight polyethylene powder having a content of ˜50 dl / g and obtained by at least the following two-step polymerization reaction at a temperature not higher than the melting point of the polyethylene. (First stage) By a catalyst comprising a solid catalyst component containing at least Mg, Ti and / or V and an organoaluminum compound,
Ethylene is polymerized in the absence of hydrogen or at a reduced hydrogen concentration, and the intrinsic viscosity in decalin at 135 ℃ is 12-5.
A step of producing 50 to 99.5 parts by weight of 0 dl / g polyethylene. (Second stage) A step of producing 50 to 0.5 parts by weight of polyethylene by polymerizing ethylene under the hydrogen concentration increased from the first stage.