JPH01156349A - Polyolefin composition - Google Patents

Abstract

PURPOSE:To obtain the title compsn. having excellent wear resistance, impact resistance and abrasive characteristics, causing no delamination, being injection- moldable and having excellent long-range thermal stability, which is comprised of a polyolefin consisting of an ultrahigh MW polyolefin and a low-high MW polyolefin and a metal salt of a higher fatty acid. CONSTITUTION:The title compsn. is comprised of 100pts.wt. polyolefin (A) consisting of an ultrahigh MW polyolefin (a) having an intrinsic viscosity of 10-40dl/g measured in decalin solvent at 135 deg.C and a low-high MW polyolefin (b) having an intrinsic viscosity of 0.1-5dl/g measured in decalin solvent at 135 deg.C, wherein the amt. of the component (a) is in the range of 15-40wt.% based on the total amt. of the components (a) and (b), having an intrinsic viscosity [eta]c in the range of 3.5-15dl/g measured in decalin solvent at 135 deg.C and a dissolution torque T of 4.5kg.cm or less, and 0.005-5pts.wt. metal salt of a higher fatty acid (B), e.g., calcium stearate.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention is suitable for obtaining injection molded products that have excellent abrasion resistance, impact resistance, and sliding properties and that do not cause delamination. The present invention relates to an injection moldable polyolefin composition having excellent heat stability and long-term heat resistance stability.

Technical background of the invention and its problems Ultra-high molecular weight polyolefins, such as ultra-high molecular weight polyethylene, have better impact resistance, abrasion resistance, sliding properties, chemical resistance, and tensile strength than general-purpose polyolefins, such as general-purpose polyethylene. It has excellent strength, etc., and its use as an engineering plastic is expanding. However, because ultra-high molecular weight polyethylene has an extremely high melt viscosity and poor fluidity compared to general-purpose polyethylene, it is extremely difficult to mold it by ordinary extrusion molding or injection molding, and most of it is molded by compression molding. Currently, only a small portion of the material is extruded into rod shapes at extremely low speeds.

If such ultra-high molecular weight polyethylene, which has poor melt flowability, is molded by normal injection molding, shear failure flow will occur during the process of filling the resin into the mold cavity, and the resulting molded product will have mica-like layers. Peeling occurs, and not only is it impossible to obtain a molded product having the excellent properties of ultra-high molecular weight polyethylene, but the result is often that the molded product is inferior to general-purpose polyethylene molded products.

The applicant has previously developed an injection molding method that does not cause delamination.
A method in which the volume of the mold cavity is slightly increased before resin injection molding or before the end of injection molding, and then compressed to a predetermined volume (Japanese Patent Publication No. 57-30067, Japanese Patent Publication No. 1988-60)
No. 58010) was proposed. By employing such a method, it has become possible to obtain an injection molded product that does not cause delamination and has the impact resistance and abrasion resistance that ultra-high molecular weight polyethylene has. However, in order to injection mold ultra-high molecular weight polyethylene using this method, it is necessary to use an injection molding machine equipped with a variable mold width mechanism, etc., and in any case, a general-purpose polyethylene index molding machine must be used as is. The problem was that it could not be used.

On the other hand, various methods have been proposed for improving the melt fluidity of ultra-high molecular weight polyolefins, including mixing ultra-high molecular weight polyolefins with low to high molecular weight polyolefins.

For example, in Japanese Patent Application Laid-Open No. 177036/1983, Molecules!
An ultra-high molecular weight polyethylene composition with improved moldability is disclosed, which comprises 100 parts by weight of ultra-high molecular weight polyethylene having a molecular weight of 1 million or more and 10 to 60 parts by weight of a low molecular weight polyethylene having a molecular weight of 5,000 to 20,000. This Japanese Patent Application Laid-Open No. 57177036 states that when molding a 50 m thick slab by compression molding, the moldability of the ultra-high molecular weight polyethylene composition as described above is as follows: The molding cycle was improved to 200'C x 2 hours.
In addition, in the ram extrusion molding method, the pipe extrusion speed is also 5 cm.
It is stated that the distance is improved from 1 minute to 10 cm in 1 minute.

However, when such an ultra-high molecular weight polyethylene composition containing a large amount of ultra-high molecular weight polyethylene is molded using a normal injection molding machine, the resulting molded product may undergo layer delamination, making it difficult to obtain a molded product with good performance. It is not possible.

Furthermore, JP-A-59-126446 discloses an ultra-high molecular weight polyethylene resin composition obtained by mixing 95 to 50 parts by weight of an ultra-high molecular weight polyethylene resin and 5 to 50 parts by weight of a general-purpose polyolefin resin. ing. JP-A-59-126446 discloses a composition using a silane-modified polyethylene resin with a melt index of 2.5 or 5.0 g/10 min as a general-purpose polyolefin resin. Moreover, as shown in Table 1 of the same publication, the moldability is not sufficiently good for all compositions. Similar to the above-mentioned compositions, such ultra-high molecular weight polyethylene resin compositions also contain a large amount of ultra-high molecular weight polyethylene components, and the problem of delamination of the resulting injection molded products remains unresolved.

On the other hand, Japanese Patent Publication No. 58-41309 discloses 85 to 50 parts by weight of polyethylene with a viscosity average molecular weight of 500,000 to 150,000, and granular polyethylene with a viscosity average molecular weight of 1,000,000 or more and a particle size of 10 mesh or less. High molecular weight polyethylene 1
A polyethylene composition containing 5 to 50 parts by weight is disclosed.

As described in Column 3, lines 17-28 of the same publication, this polyethylene composition does not improve the moldability of ultra-high molecular weight polyethylene, but uses the powdery state of ultra-high molecular weight polyethylene to create a different shape. The purpose is to reduce the orientation and provide molded products with excellent impact resistance. Moreover, such a composition, which is a mechanical mixture of polyethylene and granular ultra-high molecular weight polyethylene, has a high melting torque of 1~1 and even when molded with a normal injection molding machine, delamination occurs in the molded product as described above. cannot be prevented from doing so.

Also, Japanese Patent Publication No. 59-10724 and Japanese Unexamined Patent Publication No. 57
Japanese Patent Publication No. 141409 discloses a method in which polyethylenes having different molecular weights are continuously polymerized in multiple stages in three or more polymerization vessels. However, their purpose is to produce polyethylene with an improved extrusion die swell, and not to improve injection molded products. The content of the ultra-high molecular weight polyethylene specifically described in the above publications is 10% by weight or less, and the MI of the composition is 0.3 or the intrinsic viscosity "η" is 2.
3-3. Od, Q /9 (approximately 0.
Even if the composition of 2 to 0.8) is injection molded, the content of ultra-high molecular weight polyethylene is very small at 10% by weight or less, so it is difficult to produce extruded molded products with excellent wear resistance and impact resistance. You can't get it.

Furthermore, Japanese Patent Publication No. 46-11349 discloses that in the first step, 5 to 30% by weight of an ethylene/α-olefin copolymer having a reduced specific viscosity of 30 to 5 is polymerized, and in the second step, the reduced specific viscosity is 4. .6 to 1.5 polyethylene or ethylene α
- A method of polymerizing an olefin copolymer to obtain a polymer homogeneously mixed with said polymer is disclosed. However, the purpose thereof is to improve the moldability in extrusion molding of bottles, cables, tubes, etc., as mentioned above, and is not concerned with improving extrusion molded products. Also, even if η or 2. is specifically described in such a publication.
Even if the composition No. 9 is injection molded, the molded product obtained is inferior in wear resistance, impact resistance, etc.

In addition, ultra-high molecular weight polyolefin polymers such as those mentioned above,
All of them had the problem of poor thermal stability during molding and poor long-term heat resistance stability.

OBJECTS OF THE INVENTION An object of the present invention is to provide an injection-moldable polyolefin composition containing an ultra-high molecular weight polyolefin as a component and having extremely excellent injection moldability.

Another object of the present invention is to provide ultrahigh molecular weight polyolefins that do not cause delamination without impairing their inherent excellent mechanical properties such as abrasion resistance, impact resistance, and sliding properties. The object of the present invention is to provide an injection moldable polyolefin composition that is suitable for obtaining extruded molded products and has excellent thermal stability during molding and long-term heat resistance stability.

Summary of the Invention The injection moldable polyolefin composition of the present invention has (A) (i) an intrinsic viscosity [η] measured in a decalin solvent of 135° C. of 10 to 40 d, I) 15? The ultra-high molecular weight polyolefin has an intrinsic viscosity [η] measured in decalin solvent at 135°C.

0.1~5d! J/s of low molecular weight to high molecular weight polyolefin; (iii) The intrinsic viscosity [η]C measured in decalin solvent at 135°C is in the range of 3.5 to 156ρ/7, and (1■) the dissolution torque is 4.5Kg. It is characterized by comprising: 100 parts by weight of a polyolefin having a molecular weight of less than cm, and (B) 0.005 to 5 parts by weight of a metal salt of a higher fatty acid.

DETAILED DESCRIPTION OF THE INVENTION The injection moldable polyolefin composition according to the present invention will be specifically described below.

Polyolefin (A>) The polyolefin used in the present invention consists of an ultra-high molecular weight polyolefin and a low molecular weight N to high molecular weight polyolefin, and the ultra-high molecular weight polyolefin and the low molecular weight to high molecular weight polyolefin will be explained below.

135 of the ultra-high molecular weight polyolefin used in the present invention
The intrinsic viscosity [η] measured in °C decalin solvent is 10
~406ρ/3, preferably in the range of 15 to 35 dll/y. This intrinsic viscosity [η]u゛ is 10d, Il, 1
If it is less than 4Qd, Il/9, the mechanical properties of the injection molded product tend to deteriorate, which is undesirable. On the other hand, if it exceeds 4Qd, Il/9, the appearance of the injection molded product is poor, flow marks occur, and delamination occurs. Therefore, it is undesirable.

The intrinsic viscosity [η
]h is 0.1 to 5dρ/7, preferably 0.5 to 3d
It is in the range of ρ/q. This intrinsic viscosity [η] h is 0.1
If it is less than 6179, the molecular weight is too low and there is a risk of bleeding to the surface of the injection molded product, so it is not preferable.
d.I! If /y is exceeded, melt fluidity decreases, making it difficult to use a general-purpose polyethylene injection molding machine as is, which is not preferable.

The ultra-high molecular weight polyolefins and low molecular weight to high molecular weight polyolefins mentioned above include, for example, ethylene,
α of propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 4-methyl-1-pentene, 3-methyl-1-pentene, etc.
- Consists of homopolymers or copolymers of olefins. Among these, ethylene homopolymers or copolymers of ethylene and other α-olefins, with ethylene as the main component, are desirable.

In the polyolefin according to the present invention, the above-mentioned ``ultra-high molecular weight polyolefin'' and low-molecular weight to high-molecular weight polyolefin are in such a proportion that the above-mentioned ultra-high molecular weight polyolefin occupies 15 to 40% by weight with respect to the total weight of both polyolefins. In other words, the low molecular weight to high molecular weight polyolefins are present in such a proportion that they account for 85 to 60% by weight based on the total weight of both polyolefins. The ultra-high molecular weight polyolefin as described above is 20 to 35% by weight based on the total weight of both polyolefins.
Preferably, it is present in such a proportion that it accounts for . If the amount of ultra-high molecular weight polyolefin is less than 15% by weight, the resulting injection molded product tends to have poor mechanical properties, which is undesirable, while if it exceeds 40% by weight, delamination may occur in the resulting injection molded product. This is undesirable because it results in a molded product with good mechanical properties not being obtained.

The polyolefin used in the present invention essentially consists of an ultra-high molecular weight polyolefin and a low to high molecular weight polyolefin, which are present in the above quantitative proportions.

Therefore, the polyolefin used in the present invention has 13
Intrinsic viscosity measured in decalin solvent at 5°C [η1o is 3.
The melting torque T (K
y・cm) is less than 4.5/(g・cm).
Here, the melting torque T is determined using a JSR Curastmeter (manufactured by Imao Kikai Kogyo KK) at a temperature of 240'C and a pressure of 5.
This is a value measured under the conditions of Kg/d, amplitude 3 degrees, frequency 6 CPH.

If the above [η]C is less than 3.56j/y, the resulting injection molded product may have poor mechanical strength, especially wear resistance, which is undesirable.On the other hand, if [η]C is less than 15dρ/g, If it exceeds this, delamination will occur in the resulting injection molded product, resulting in a decrease in mechanical strength such as abrasion resistance, which is not preferable.

Also, the melting torque T is 4.5! If it exceeds j-cm, it is not preferred because it will not bite into a normal screw during molding and injection molding will not be possible with a general-purpose injection molding machine.

The polyolefin used in the present invention is preferably [η
]C is in the range of 4.0 to 10d, Q/d.

The polyolefin used in the present invention can also be prepared by blending an ultra-high molecular weight polyolefin and a low-molecular weight to high-molecular weight polyolefin in the above proportions, but according to the investigations conducted by the present inventors, Polyolefins obtained by the following multi-step polymerization method in which olefins are polymerized in multiple steps in the presence of a catalyst formed from an active solid titanium catalyst component and an organoaluminum compound catalyst component have excellent properties. I found out.

Such a multi-step polymerization method is carried out in the presence of a Daegler-type catalyst formed from a highly active titanium catalyst component (a) containing magnesium, titanium and halogen as essential components, and an organoaluminium compound catalyst component (b). , carried out by multistage polymerization of olefins. That is, in at least one polymerization step, the intrinsic viscosity is 10 to 4. Od
An ultra-high molecular weight polyolefin with ρ/J is produced, and in another polymerization step, the olefin is polymerized in the presence of hydrogen to produce a low to high molecular weight polyolefin with an intrinsic viscosity of 0.1 to 5 dρ/g.

The particular Ziegler type catalyst used is essentially a catalyst of a particular nature formed from a solid titanium catalyst component and an organoaluminum compound catalyst component. As the solid titanium catalyst component, it is preferable to use, for example, a highly active fine powder catalyst component with a narrow particle size distribution, an average particle size of about 0.01 to 5 μ7n, and several microspheres fixed to each other. It is. A highly active finely powdered titanium catalyst component having such properties is obtained, for example, in the solid titanium catalyst component disclosed in JP-A No. 56-811, by bringing a liquid magnesium compound into contact with a liquid titanium compound. When precipitating a solid product, it can be manufactured by strictly adjusting the precipitation conditions. in particular,
In the method disclosed in Japanese Patent Application Laid-Open No. 56-811,
A hydrocarbon solution in which magnesium chloride and higher alcohol are dissolved and titanium tetrachloride are mixed at a low temperature, and then 50%
When precipitating a solid product by raising the temperature to about ~100°C, a trace amount of monocarboxylic acid ester of about 0.01 to 0.2 mole per mole of magnesium chloride is allowed to coexist and under strong stirring conditions. By performing the precipitation,
A highly active finely powdered titanium catalyst component can be prepared. If necessary, it may be washed with titanium tetrachloride.

In this way, a solid catalyst component having excellent activity and particle state can be obtained. Such catalyst components are
For example, it contains about 1 to about 6% by weight of titanium, the halogen/titanium (atomic ratio) is about 5 to about 90, and the magnesium/titanium (atomic ratio) is about 5 to about 90.
Titanium (atomic ratio) ranges from about 4 to about 50.

Furthermore, the slurry of the solid titanium catalyst component prepared as described above is sheared at high speed, and the particle size distribution is narrow and the average particle size is 0.01 to 5t1.
Microspheres having a diameter of 0.05 to 3 μm, preferably in the range of 0.05 to 3 μm, are also suitably used as highly active fine powder titanium catalyst component. Specifically, a method for high-speed shearing treatment is, for example, a method in which a slurry of solid titanium catalyst components is treated in an inert gas atmosphere using a commercially available homomixer for an appropriate period of time. In this case, for the purpose of preventing deterioration of catalyst performance, a method may be adopted in which titanium and an organic aluminum compound are added in an equimolar amount in advance. Furthermore, it is also possible to adopt a method in which the slurry after treatment is filtered through a sieve to remove coarse particles. By these methods, the highly active fine powdered titanium catalyst component having the fine particle size can be obtained.

The polyolefin used in the present invention is produced by using the highly active finely powdered titanium catalyst component (a) and the organoaluminum compound catalyst component (b) as described above, together with an electron donor if necessary, and by using pentane, hexane, etc. It can be produced by slurry polymerizing olefins in a hydrocarbon medium such as , heptane, kerosene, etc., usually at a temperature in the range of 0 to 100'C, in a multi-stage polymerization process of at least two or more stages.

Examples of the organoaluminum compound catalyst component (b) include 1-realkylaluminums such as triethylaluminum and triisobutylaluminum, siaaluminum chlorides such as diethylaluminum chloride and diisobutylaluminum chloride, and alkylaluminums such as ethylaluminum sesquichloride. Sesquichloride or a mixture thereof is preferably used.

In the multistage polymerization process of the olefin, a multistage polymerization apparatus in which at least two or more polymerization vessels are usually connected in series is employed, such as a two-stage polymerization method, a three-stage polymerization method,... an n-stage polymerization method. will be implemented. It is also possible to perform a multi-stage polymerization method using a batch polymerization method in one polymerization tank. It is necessary to produce a specific amount of ultra-high molecular weight polyolefin in at least one polymerization tank of the multi-stage polymerization process. The polymerization step for producing the ultra-high molecular weight polyolefin may be a first stage polymerization step,
It may be an intermediate polymerization step or may be performed in multiple stages of two or more stages. It is preferable to produce an ultra-high molecular weight polyolefin in the first stage polymerization step because the polymerization treatment operation is easy and the physical properties of the resulting polyolefin can be easily controlled. In the polymerization step, 15 to 4 of the polyolefin used in the present invention is
0% by weight is the intrinsic viscosity [η]u (1 in decalin solvent
(measured at 35°C) is 10 to 40 dβ/9, and furthermore, 18 to 37% by weight of the polyolefin used in the present invention, especially 21 to 35% by weight of the polyolefin used in the present invention. Weight%, intrinsic viscosity [η] is 15 to 35dρ/3, especially 18 to 3
It is preferred that the ultra-high molecular weight polyolefin has an ultra-high molecular weight of 0.6 ρ/J. In this polymerization step,
Intrinsic viscosity [η] of the ultra-high molecular weight polyolefin produced,
is less than 10 dρ/8, and even if the ultra-high molecular weight polyolefin produced in the polymerization step is outside the range of 15 to 40% by weight, it is difficult to obtain an injection moldable polyolefin.

In the multi-stage polymerization process, in the polymerization process for producing an ultra-high molecular weight polyolefin, polymerization is carried out in the presence of a catalyst consisting of the highly active titanium catalyst component (a) and the organoaluminum compound catalyst component (b). Polymerization can be carried out by gas phase polymerization or liquid phase polymerization. In either case, in the polymerization step to produce the ultra-high molecular weight polyolefin, the polymerization reaction is optionally carried out in the presence of an inert medium. For example, gas phase polymerization is carried out in the presence of a diluent consisting of an inert medium, if necessary, and liquid phase polymerization is carried out, if necessary, in the presence of a solvent consisting of an inert medium.

In the polymerization step for producing the ultra-high molecular weight polyolefin, the highly active titanium catalyst component (a) is used as a catalyst, for example, in an amount of about 0.001 to about 2 titanium atoms per 1.11 of the medium.
0 milligram atom, preferably about 0.005 to about 10 milligram atom, organoaluminum compound catalyst component (b)
are preferably used in such a proportion that the AI/Ti (atomic ratio) is from about 0.1 to about 1000, particularly from about 1 to about 500.

The temperature of the polymerization step to produce the ultra-high molecular weight polyolefin is usually about -20 to about 120°C, preferably about O
to about 100°C, particularly preferably from about 5 to about 95°C. The pressure during the polymerization reaction must be within a pressure range that allows liquid phase polymerization or gas phase polymerization at the above temperature, for example, from atmospheric pressure to about 100 K'J/crA, preferably from atmospheric pressure to about 50 K'J/crA! In addition, the polymerization time in the polymerization step is such that the amount of prepolymerized polyolefin produced is about 1000!7 or more, preferably about 2000y or more per milligram atom of titanium in the highly active titanium catalyst component. In the polymerization step, in order to produce the ultra-high molecular weight polyolefin, it is preferable to carry out the polymerization reaction in the absence of hydrogen. Thereafter, it is also possible to temporarily isolate the polymer under an inert medium atmosphere and store it.

Inert media that can be used in the polymerization process to produce the ultra-high molecular weight polyolefin include, for example, propane, butane, pentane, hexane, heptane,
Aliphatic hydrocarbons such as octane, decane, kerosene; alicyclic hydrocarbons such as cyclopentane, cyclohexane; aromatic hydrocarbons such as benzene, toluene, xylene; halogenated hydrocarbons such as dichloroethane, methylene chloride, chlorobenzene; Alternatively, a mixture of these can be mentioned. Particularly desirable is the use of aliphatic hydrocarbons.

In addition, when producing the polyolefin used in the present invention, the presence of hydrogen is required in the polymerization step other than the polymerization step for producing the ultra-high molecular weight polyolefin, that is, the polymerization step for obtaining a low molecular weight to high molecular weight polyolefin. Below, a polymerization reaction of the remaining olefin is carried out. If the polymerization process for producing an ultra-high molecular weight polyolefin is the first stage polymerization process, then the second stage and subsequent polymerization processes correspond to the polymerization process. If the polymerization step is located after the ultra-high molecular weight polyolefin producing polymerization step,
A polyolefin containing the ultra-high molecular weight polyolefin is supplied to the polymerization step, and when the polymerization step is located after a polymerization step other than the ultra-high molecular weight polyolefin-producing polymerization step, the low molecular weight or high molecular weight produced in the previous step is supplied. The polyolefin is fed and the polymerization is carried out in each case continuously. At that time, the polymerization step usually includes
Feedstock olefin and hydrogen are supplied. When the polymerization step is the first stage polymerization step, a catalyst consisting of the highly active titanium catalyst component (a) and the organoaluminum compound catalyst component (b) is supplied, and the polymerization step is the second stage polymerization step.
In the case of subsequent polymerization steps, the catalyst contained in the polymerization liquid produced in the previous step can be used as is, or the highly active titanium catalyst component (a) and/or the catalyst may be used as necessary. Alternatively, it is okay to additionally supplement the organic aluminum compound (b).

The low molecular weight to high molecular weight polyolefin thus obtained is 5 to 70% by weight, preferably 20 to 60% by weight, based on the total olefin components polymerized in the entire polymerization process.
, particularly preferably in an amount of 25 to 55% by weight.

The hydrogen supply ratio in the polymerization steps other than the ultra-high molecular weight polyolefin production polymerization step is usually 0.01 to 5 mols of hydrogen per mole of olefin supplied to each polymerization step.
0 mol, preferably in the range of 0.05 to 30 mol.

The concentration of each catalyst component in the polymerization solution in the polymerization tank in the polymerization process other than the ultra-high molecular weight polyolefin production polymerization process is about 0.001 to 100% in terms of titanium atoms per 1 ρ of polymerization volume. about 0.1 milligram atom,
Preferably, the amount is about 0.005 to about 0.1 milligram atoms, and the AI/Ti (atomic ratio) of the polymerization system is about 1 to about 1000,
Preferably, it is adjusted to about 2 to about 500. For this purpose, an organoaluminum compound catalyst component (b) can be additionally used as necessary. In addition, hydrogen/electron donors, halogenated hydrocarbons, etc. may be avoided in the polymerization system for the purpose of controlling the molecular weight, molecular weight distribution, etc.

The polymerization temperature is within a humidity range that allows slurry polymerization and gas phase polymerization, and is about 40'C or higher, more preferably about 50 to about 10
A range of 0'C is preferred. Further, the polymerization pressure is, for example, atmospheric pressure to about 100 kg/cA, particularly atmospheric pressure to about 50 kg/cA.
A range of Kg/ci is preferred. The polymerization time is preferably set so that the amount of polymer produced is about 1,000 g or more, particularly preferably about 50,009 g or more, per milligram atom of titanium in the titanium catalyst component.

Polymerization steps other than the polymerization step for producing an ultra-high molecular weight polyolefin can be similarly carried out by a gas phase polymerization method or a liquid phase polymerization method. Of course, it is also possible to employ different polymerization methods in each polymerization step. Among the liquid phase polymerization methods, a slurry suspension polymerization method is preferably employed.

In either case, the polymerization reaction is usually carried out in the presence of an inert medium in the polymerization step. For example, gas phase polymerization processes are carried out in the presence of an inert medium diluent, and liquid phase slurry suspension polymerization processes are carried out in the presence of an inert medium solvent.

As the inert medium, the same inert medium as exemplified in ci5 in the polymerization step for producing the ultra-high molecular weight polyolefin can be exemplified.

Polyolefin composition obtained in the final stage polymerization process [
η]C is usually 3.5 to 15CIQ/9, preferably 4.0 to 10d, Il/y, and the melting torque is 4.5Kg・
The polymerization reaction is carried out so that the diameter is less than 1 cm.

The multi-step polymerization method can be carried out in a batch, semi-continuous or continuous manner.

The olefins to which the multi-stage polymerization method can be applied include:
As mentioned above, ethylene, propylene, 1-butene, 1-
Pentene, 1-hexene, 1-octene, 1-decene,
Examples include α-olefins such as 1-dodecene, 4-methyl-1-pentene, and 3-methyl-1-pentene, and it can also be applied to a method for producing homopolymers of these α-olefins. , it can also be applied to a method for producing a copolymer consisting of two or more mixed components. Among these α-olefins, ethylene or ethylene and other α-olefins
- It is preferable to apply the method of the present invention to a method for producing an ethylene polymer having an ethylene component as a main component, which is a copolymer with an olefin.

Metal salt of higher fatty acid (B) The injection moldable polyolefin combination acid product according to the present invention is
In addition to the above-mentioned polyolefin (A>), it contains a higher fatty acid metal salt (B).

Examples of metal salts of higher fatty acids include magnesium salts of higher fatty acids such as stearic acid, oleic acid, lauric acid, capric acid, araxic acid, palmitic acid, and behenic acid;
alkaline earth metal salts such as calcium salts and barium salts,
Alkali metal salts such as cadmium salts, zinc salts, lead salts, sodium salts, potassium salts, and lithium salts are used. Specifically, the following compounds are used.

Magnesium stearate 1 cum, Magnesium laurate, Sodium palmitate, Calcium stearate,
Calcium oleate, calcium laurate, barium stearate, barium oleate, barium laurate, barium araxinate, barium behenate, zinc stearate, zinc oleate, zinc laurate, stearate, sodium stearate, palmitic acid Sodium, sodium laurate, potassium stearate, potassium laurate, calcium 12-hydroxystearate, etc.

These metal salts of higher fatty acids may be used alone or in combination.

In the injection moldable polyolefin composition according to the present invention, the metal salt (B) of a higher fatty acid as described above is contained in an amount of 0.005 to 5 parts by weight, preferably 0.01 parts by weight, based on 100 parts by weight of the polyolefin (A). It is used in an amount of ~0.5 parts by weight, more preferably 0.05-0.2 parts by weight. The amount of metal salt (B) of this higher fatty acid is polyolefin (A>10
If the amount is less than 0.005 parts by weight relative to 0 parts by weight, residual chlorine in the polymer derived from the catalyst will not be absorbed sufficiently;
This is undesirable because it causes resin deterioration, and on the other hand, exceeding 5 parts by weight is undesirable because not only does the cost of the stabilizer increase, but also the properties of the resin, such as tensile elongation and compatibility, may be impaired. .

In addition to the above components (A) and (B), the injection moldable polyolefin composition of the present invention includes, for example, heat stabilizers, weather stabilizers, pigments, dyes, lubricants, carbon black, talc, glass fibers, etc. Inorganic fillers or reinforcing agents, flame retardants, neutron shielding agents, and other compounding agents that are usually added and mixed to polyolefins can be added within a range that does not impair the purpose of the present invention.

Effects of the Invention The injection moldable polyolefin composition of the present invention has excellent mechanical properties possessed by ultra-high molecular weight polyolefins, such as impact resistance, abrasion resistance, chemical resistance, lubricity, water absorption, sliding properties, etc. It can be injection molded with almost no damage to the properties of ultra-high molecular weight polyolefins, and without the delamination of molded products that occurs when using general-purpose injection molding machines, which is a major drawback of ultra-high molecular weight polyolefins. Because of its excellent durability and long-term heat resistance stability, it can be used not only in bearings, gears, and cams, where conventional general-purpose polyolefins cannot be used due to poor impact resistance and abrasion resistance, but also in sliding applications such as home appliances and OA equipment. It can be used for various purposes including moving parts.

[Example] Next, the present invention will be explained in more detail by giving examples.
The present invention is not limited to these examples in any way unless they go beyond the gist of the invention.

Example 1 <Catalyst preparation> Anhydrous magnesium chloride 47.6y (0.5 mol), decalin 0.25y. Q and 0.23.11 (1.5 mol) of 2-ethylhexyl alcohol at 130'C
After heating for 2 hours to make a homogeneous solution, ethyl benzoate 7
．． 4d (50 mmol) was added. This homogeneous solution was added dropwise to 1.5 ρ TIC14 maintained at -5°C over 1 hour with stirring.

A glass separable flask (No. 3) was used as the reactor, and the stirring rate was 950 ppm.

After the dropwise addition, the temperature was raised to 90'C, and a reaction was carried out at 90'C for 2 hours. After the reaction was completed, the solid portion was collected by filtration and further washed with hexane for 4 minutes to obtain a highly active finely powdered titanium catalyst component. The catalyst component contained 3.8% by weight of titanium atoms.

<Polymerization> -31=Inner volume 220. f! Continuous polymerization was carried out using a continuous two-stage polymerization apparatus in which two polymerization tanks were connected in series.

130 g of n-hexylene was added to the first stage polymerization tank (hereinafter abbreviated as polymerization tank 1) of the continuous two-stage polymerization apparatus, and 6
The temperature was raised to 0°C. n-hexane at a rate of 35.11/hour, 1~liezyl aluminum at a rate of 45mM/hour, titanium catalyst at a rate of 1.0 milligram atom/hour as titanium atoms, and ethylene gas at 4.3N. It was continuously introduced into the polymerization tank 1 at a rate of 100 ml/hour. Using a pump, the polymerization mixture slurry in polymerization tank 1 is transferred to the subsequent polymerization tank (
(hereinafter abbreviated as polymerization tank 2), and set the level of polymerization tank 1 to 1.
It was kept at 30β. At that time, the polymerization pressure in polymerization tank 1 was 4.7
Kg/crttG.

In addition to the polymerization mixture slurry sent from the polymerization tank 1, n-hexane was added to the polymerization tank 2 at a rate of 251/hour.
Ethylene gas was continuously introduced at a rate of 11.2 N/hr. Further, an appropriate amount of hydrogen gas was added to adjust the composition (molar ratio) of the gas phase portion of the polymerization tank 2 to 1000 parts of ethylene and 30 parts of hydrogen. The slurry produced by the polymerization reaction was intermittently discharged from the lower part of the polymerization tank 2 using a timer valve, and the level of the polymerization tank 2 was maintained at 120ρ.

The polymerization temperature in polymerization tank 2 was 85°C, and the polymerization pressure was 7.2Kg/
It was aMG. The obtained polymer and solvent were separated by a centrifuge and dried under a N2 stream.

[η] and melting 1-lux T of the obtained polyolefin (A) were measured by the following methods.

[η]: Intrinsic viscosity measured in decalin solvent at 135°C Melting torque (min): Using JSR Curastmeter (manufactured by Bunyou Kikai Kogyo), temperature 240'C1 pressure 5K9)
/ cm, amplitude ± 3°C, frequency 6 Stress of sample in molten state measured at CPH 1 ~ lk (injection molding) 100 parts by weight of the polyolefin (A) and higher fatty acid metal salt stabilizer (B) , Calcium stearate (NOF Q Wooden) 0. 12 parts by weight using a Henschel mixer, this composition was mixed with L/D=28.25 mm.
The mixture was supplied to a single-screw extruder of 190'CC15Qrp, kneaded and granulated by passing once through a 190'CC15Qrp. The granulated pellets were molded into a square plate (130 x 120 x 2 mm) using an injection molding machine (Toshiba Corporation MIS-50) under the following conditions, and then cut to prepare a test piece.

Injection molding conditions Cylinder temperature (℃): 200/230/270/2
70; indexing pressure<Kl/c scrap): 1st/2nd - 1000/800 Cycle (sec): 1st/2nd/cooling - 5/3
/25; Injection speed (-): 2/10 SCREW rotation speed (rpm): 97; Mold temperature (°C): Water cooling (32°C) After leaving the sample in 130'C1 air at 100.300° for 500 hours, The heat resistance of each was evaluated using the following method.

Tensile test: ASTM D 638, however, the test piece shape was ASTM No. 4, the tensile speed was 50 m/min, and elongation at break = 34- (EL: %) was determined.

Example 2 Comparative Example 1 For the polyolefin (A>) obtained in Example 1, calcium 12-hydroxystearate (trade name: Calcium Himastearate, manufactured by NOF ■) was added as a stabilizer for the higher fatty acid metal salt (B). Comparative Example 1 was carried out in the same manner as in Example 1 except that the amount of the stabilizer added in Example 1 was changed as shown in Table 1.

These results are shown in Table 1.

Furthermore, the composition of polyolefin (A) and higher fatty acid metal salt (B) used in Examples 1 to 2 and Comparative Example 1 was adjusted to L/D=2.
8.25mm single screw extruder, 220℃C15Q
The mixture was kneaded and granulated by passing it through RP 1 to 5 times. The [η] and melting torque of each of the pellets granulated 1 to 5 times were measured in the same manner as in Example 1, and the thermal stability of the composition during molding was evaluated. These results are shown in Table 2.

Ichinu 4- −j7=

Claims (1)

[Scope of Claims] 1) (A) (i) An ultra-high molecular weight polyolefin having an intrinsic viscosity of 10 to 40 dl/g as measured in a decalin solvent at 135°C and an intrinsic viscosity of 0 as measured in a decalin solvent at 135°C.
．． 1 to 5 dl/g, and (ii) the ultra-high molecular weight polyolefin is comprised of: (iii) The intrinsic viscosity [η]_C measured in a decalin solvent at 135°C is in the range of 3.5 to 15 dl/g, (iv) The dissolution torque T is 4.5 Kg. An injection-moldable polyolefin composition comprising: 100 parts by weight of a polyolefin having a polyolefin of 0.1 cm or less, and (B) 0.005 to 5 parts by weight of a metal salt of a higher fatty acid. 2) The above polyolefin is produced in at least one polymerization step in the presence of a Ziegler type catalyst formed from a highly active titanium catalyst component (a) containing magnesium, titanium and halogen as essential components and an organoaluminium compound catalyst component (b). In the step, olefins are polymerized to produce ultra-high molecular weight polyolefins with an intrinsic viscosity of 10 to 40 dl/g, and in other polymerization steps, olefins are polymerized in the presence of hydrogen to produce ultra-high molecular weight polyolefins with an intrinsic viscosity of 0.1 to 5 dl/g. An injection moldable polyolefin composition according to claim 1, which is produced by a multi-step polymerization process to produce a polyolefin of molecular to high molecular weight.