JPH01156352A - 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 three specified stabilizers. 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, 0.005-5pts.wt. phenol stabilizer (B), 0.005-5pts.wt. org. phosphite stabilizer (C) and 0.005-5pts.wt. org. thioether stabilizer (D).

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. Not only does it cause peeling, making it impossible to obtain a molded product with the excellent properties of ultra-high molecular weight polyethylene, but it is also inferior to general-purpose polyethylene molded products□
This was always the result.

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 cavity mechanism, etc. In any case, it is not possible to use a general-purpose polyethylene injection molding machine as is. The problem was that it was not possible.

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, Japanese Patent Application Laid-Open No. 57-177036 discloses a product with improved moldability consisting of 100 parts by weight of ultra-high molecular weight polyethylene with a molecular weight of 1 million or more and 10 to 60 parts by weight of low molecular weight polyethylene with a molecular weight of 50'OO to 20,000. Ultra high molecular weight polyethylene compositions are disclosed. JP-A-57-17'7036 states that the moldability of the above-mentioned ultra-high molecular weight polyethylene composition is 200 m when a slab with a thickness of 50 m is molded by compression molding. It is stated that the molding cycle, which required a 3-hour molding cycle at ℃, has been improved to a 2-hour molding cycle at 200'C, and in the ram extrusion method, the pipe extrusion speed can be similarly improved from 5 cmZ to 10 cm 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-59-1264/1.6 discloses an ultra-high molecular weight polyethylene resin composition prepared 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. things are disclosed. This Japanese Patent Application Laid-Open No. 59-126446@publication° describes a composition using a silane-modified polyethylene resin with a melt index of 2.5 or 5.0y/10 min as a general-purpose polyolefin resin. However, 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 that is a mechanical mixture of polyethylene and granular ultra-high molecular weight polyethylene has a high melting torque, and even when molded with a normal injection molding machine, delamination occurs in the molded product as described above. cannot be prevented.

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 improved extrusion molding, especially blow molding, and not to improve injection molded products. The content of ultra-high molecular weight polyethylene specifically described in a publication is 10% by weight or less, and the MI of the composition is 0.3 or the intrinsic viscosity [η] is 2.3.
~3. Odρ/9 (approximately 0.2 to 0.8 converted to MI
) Even if the composition is injection molded, it is impossible to obtain an injection molded product with excellent wear resistance and impact resistance because the content of ultra-high molecular weight polyethylene is very small at 10% by weight or less.

Zarani 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 4.6-1.5 polyethylene or ethylene α
- A method of polymerizing an olefin copolymer to obtain a polymer homogeneously mixed with said polymer is disclosed. However, its purpose is to improve the moldability of bottles, cables, tubes, etc. in extrusion molding, as described above, and is not concerned with improving injection molded products. Also, even if η specifically stated in such a publication is 2
．． 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 injection molded products and has excellent thermal stability during molding and long-term heat resistance stability.

SUMMARY OF THE INVENTION A first injection moldable polyolefin composition according to the present invention comprises (A) an ultra-high molecular weight polyolefin having an intrinsic viscosity of 10 to 40 d, fl/g as measured in a decalin solvent at (i>135°C); , a low molecular weight to high molecular weight polyolefin having an intrinsic viscosity of 0.1 to 5 dl/g as measured in a decalin solvent at 135° C.; and the above-mentioned low molecular weight to high molecular weight polyolefin, and (iii) the intrinsic viscosity [η]C measured in a decalin solvent at 135° C. is 3.5 to 15 d, 0.7 g. (iv) 100 parts by weight of a polyolefin with a dissolution 1 to 4.5 kg cm or less; (B) 0.005 to 5 parts by weight of a phenolic stabilizer; (C) an organic It is characterized by consisting of 0.005 to 5 parts by weight of a phosphite stabilizer and 0.005 to 5 parts by weight of (D) an organic thioether stabilizer.

Further, the second injection moldable polyolefin composition according to the present invention comprises: (^) (i > 135°C) An ultra-high molecular weight polyolefin having an intrinsic viscosity of 10 to 406 J/g measured in a decalin solvent; (ii) The ultra-high molecular weight polyolefin consists essentially of a low molecular weight to high molecular weight polyolefin having an intrinsic viscosity of 0.1 to 5 d, I)/9 as measured in a decalin solvent; It is in the range of 15 to 40% by weight based on the total weight of the above-mentioned low molecular weight to high molecular weight polyolefin, and has an intrinsic viscosity [η]C of 3.5 to 15 dl/g as measured in decalin solvent at >135°C. (1■) 100 parts by weight of a polyolefin having a melting torque of 4.5 to 9-'Crn or less; (B) 0.005 to 5 parts by weight of a phenolic stabilizer; (C) Organic phosphite stabilizer: 0.005 to 5 parts by weight, CD) Organic thioether stabilizer: 0.005 to 5 parts by weight, (E) Metal salt of higher fatty acid: 0.005 to 5 parts by weight. It is characterized by consisting of.

DETAILED DESCRIPTION OF THE INVENTION The injection moldable polyolefin assembly 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 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
~40 dl/g, preferably 15-35 dl/g. If the intrinsic viscosity [η] is less than 10 dρ/g, the mechanical properties of the injection molded product tend to deteriorate, which is undesirable. On the other hand, if it exceeds 40 dj,l, the appearance of the injection molded product is poor, resulting in a 70-mark This is not preferable because it causes delamination and delamination.

The intrinsic viscosity [η
] h is 0.1 to 5 dll/y, preferably 0.5 to 3
d, in the range of ll/y. This intrinsic viscosity [η]h is 0
．． If it is less than 1 dρ/9, the molecular weight is too low and there is a risk of bleeding to the surface of the injection molded product, which is undesirable. On the other hand, if it exceeds 5 dl/g, the melt fluidity will decrease, so it is not suitable for general-purpose polyethylene Q] injection molding. It is difficult to use the machine as is, which is not desirable.

The ultra-high molecular weight polio, lefins and low to high molecular weight polyolefins mentioned above include, for example, ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 4- It consists of a homopolymer or copolymer of α-olefins such as methyl-1-pentene and 3-methyl-1-pentene.

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 ultra-high molecular weight polyolefin and the low-molecular weight to high-molecular weight polyolefin are present in such a proportion that the 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 a proportion of 85 to 60% by weight based on the total weight of both polyolefins. The ultra-high molecular weight polyolefins mentioned above are
Preferably, it is present in a proportion of 20 to 35% by weight based on the total weight of both polyolefins. When the amount of ultra-high molecular weight polyolefin is less than 15% by weight,
This is not preferable because the mechanical properties of the resulting injection molded product tend to be poor; on the other hand, if it exceeds 40% by weight, delamination will occur in the resulting injection molded product, resulting in a molded product with good mechanical properties. This is not desirable because it cannot be used.

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
The intrinsic viscosity [η]C measured in decalin solvent at 5°C is 3,
It is in the range of 5 to 15 dρ/g, and under melting torque (Kg・
cm') is now 4.5! It is below j-cm. In addition, melting 1 ~ Luk T is determined using a JSR Curus 1 ~ meter (manufactured by Imao Kikai Kogyo KK) at a temperature of 240'C1 and a pressure of 5.
This is a value measured under the conditions of Ky/cri, amplitude 3°, frequency 6 CPH.

If the above [η]C is less than 3.5 d, fl /g, the resulting injection molded product may have poor mechanical strength, especially wear resistance, which is undesirable. ,
If Il/y is exceeded, delamination occurs in the injection molded product obtained, resulting in a decrease in mechanical strength such as wear resistance, which is not preferable.

Also, the lower melting torque is 4. ．． If it exceeds 5 Ng·cm, it is not preferable 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 4. It is in the range of 0 to 10 dρ/J.

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 studies of the present inventors, a specific high-molecular weight polyolefin 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 understand that
.

Such a multi-step polymerization method is carried out 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 organoaluminum compound catalyst component (b). It is carried out by multistage polymerization of olefins. That is, in at least one polymerization step, the intrinsic viscosity is 10 to 40 d,
An ultra-high molecular weight polyolefin of fl/y 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 dl/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 μm, and several microspheres fixed to each other. It is. A highly active finely powdered titanium catalyst component having such properties is used, for example, in the solid titanium catalyst component disclosed in JP-A-56-811, in which a liquid magnesium compound and a liquid titanium compound are brought into contact with each other. The solid product can be produced by strictly adjusting the precipitation conditions. in particular,
In the method disclosed in Japanese Patent Publication No. 56-811, a hydrocarbon solution in which magnesium chloride and a higher alcohol are dissolved and titanium tetrachloride are mixed at a low temperature, and then 5
When precipitating a solid product by raising the temperature to about 0-100'C, 0.01-0.
A highly active finely powdered titanium catalyst component can be prepared by coexisting a small amount of about 2 moles of monocarboxylic acid ester and performing the precipitation under strong stirring conditions. 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% 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.

Further, the slurry of the solid titanium catalyst component prepared as described above is subjected to a high-speed shearing treatment, and the particle size distribution is narrow and the average particle size is 0.01 to 5 μm.
Microspheres, preferably in the range of 0.05 to 3 μm, are also suitably used as the highly active finely powdered titanium catalyst component. Specifically, a method for high-speed shearing treatment is, for example, a method in which a slurry of a solid titanium catalyst component is treated in an inert gas atmosphere using a commercially available homomixer for an appropriate period of time. In order to prevent deterioration of catalyst performance,
It is also possible to adopt a method in which titanium and an equimolar amount of an organoaluminum compound are added in advance. Alternatively, a method may be adopted in which the treated slurry 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 trialkylaluminum such as triethylaluminum and triisobutylaluminum, siaaluminum chloride such as diethylaluminum chloride and diisobutylaluminum chloride, and alkylaluminum sesquichloride such as ethylaluminum 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, an intermediate polymerization step, or a plurality of 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, the polyolefin used in the present invention is
40% by weight of the intrinsic viscosity [η], (1 in decalin solvent)
It is necessary that the ultra-high molecular weight polyolefin (value measured at 35° C.) is 10 to 40 d, 1/y, and furthermore, 18 to 37% by weight of the polyolefin used in the present invention, especially 21 ~35% by weight is
Intrinsic viscosity [η]1 is 15 to 35 dρ/J, especially 18 to
Preferably, it is dominated by an ultra-high molecular weight polyolefin having a molecular weight of 30 dj/y. In this polymerization process, the intrinsic viscosity [η] of the ultra-high molecular weight polyolefin produced
U is 106. Even if it is less than fl/y, or 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) iJ5 and the organoaluminum compound catalyst component (b). . Polymerization can be carried out by gas phase polymerization or liquid phase polymerization. In either case, the polymerization reaction is carried out in the presence of an inert medium, if necessary, in the step of "polymerization to produce an ultra-high molecular weight polyolefin." 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 process for producing the ultra-high molecular weight polyolefin, the highly active titanium catalyst component (a) is used as a catalyst, for example, about 0.001 to about 20 milligram atoms, preferably about 0.005 to about 20 milligram atoms per titanium atom in the medium 1. 10 mg atoms, organoaluminium compound catalyst component (mouth),
AI/Ti (atomic ratio) is about 0.1 to about 1000. In particular, it is preferable to use it in a ratio of about 1 to about 500.

The temperature of the polymerization step to form the ultra-high molecular weight polyolefin is usually in the range of about -20 to about 120'C1, preferably about 0 to about 100'C1, and particularly preferably about 5 to about 95C. In addition, the repulsive force during the polymerization reaction is within a pressure range that allows liquid phase polymerization or gas phase polymerization at the above temperature, for example, atmospheric pressure to about 100 Kg/cM, preferably atmospheric pressure to
In the range of approximately 50 to 3/cm. Further, the polymerization time in the polymerization step may be set so that the amount of prepolymerized polyolefin produced is about 1oooy or more, preferably about 20,009 or more per milligram atom of titanium in the highly active titanium catalyst component. Moreover, 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. Furthermore, after carrying out the polymerization reaction, it is also possible to temporarily isolate and store the polymer under an inert medium atmosphere.

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, and kerosene; Alicyclic hydrocarbons such as cyclopenkune and cyclohexane; Aromatic hydrocarbons such as benzene, 1-toluene, and xylene; Halogenated hydrocarbons such as dichloroethane, methylene chloride, and chlorobenzene; Alternatively, a mixture thereof can be used. Particularly desirable is the use of aliphatic hydrocarbons.

In addition, when producing the polyolefin used in the present invention, hydrogen is A polymerization reaction of the remaining olefin is carried out in the presence of. 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 a polymerization step after the step, the catalyst contained in the polymerization product liquid produced in the previous step can be used as is, or the highly active titanium catalyst component (a) and/or the catalyst can 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 product liquid 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 of the treated catalyst per 1 g 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 the polymerization system, hydrogen/electron donors, halogenated hydrocarbons, etc. may be present in order to adjust the molecular weight, molecular weight distribution, etc.

The polymerization temperature is within a temperature range that allows slurry polymerization and gas phase polymerization, and is about 40'C or higher, more preferably about 50 to about 10°C.
A range of 0'C is preferred. Further, the polymerization pressure is, for example, atmospheric pressure to about 100 K9/cM', particularly atmospheric pressure to
A range of about 50 K'j/ct/l is preferred. The amount of polymer produced is about ioooog or more, particularly preferably about 5 ioooog, per milligram atom of titanium in the titanium catalyst component.
It is preferable to set the polymerization time so that '0OO9 or more is achieved.

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.

Examples of the inert medium include the same inert media exemplified in the polymerization process for producing the ultra-high molecular weight polyolefin.

Polyolefin composition obtained in the final stage polymerization process [
[eta]C is usually 3.5 to 156 N/g.

Preferably 4.0 to 10 dβ/g, melting torque 4.5
The polymerization reaction is carried out so that the amount is below Kg·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.

Phenolic stabilizer (B) The injection moldable polyolefin composition according to the present invention includes:
In addition to the above polyolefin (A>), it contains a phenolic stabilizer (B).

As the phenolic compound, conventionally known compounds can be used without particular limitation, and specifically, the following compounds are used.

2.6-di~t-butyl-4-methylphenol, ? ,
6-di-cyclohexyl-4-methylphenol, 2.
6-diimbropyru-4-ethylphenol, 2.6-
Di-t-amyl-4-methylphenol, 2.6-di-t-octyl-4-n-propylphenol, 2.6-
Dicyclohexyl-4-n-octylphenol, 2-isopropyl-4-methyl-6-t-butylphenol, 2-t-butyl-2-edy-6-t-octylphenol, 2-isobutyl-4-ethyl-6- t-hexylphenol, 2-cyclohexyl-4-n-butyl-6-isoprobylphenol, tetrakis[methylene(3,5-di-t-butyl-4-
Hydroxy) hydrocinnamate comethane etc.

Furthermore, a phenol compound having two or more phenol nuclei can also be used as the phenol stabilizer. Specifically, the following compounds are used as such phenolic compounds having two or more phenol nuclei.

2.2゛-Methylenebis(4-methyl-6-t-butylphenol) 4.4°-Butylidenebis(3-methyl-6-t-butylphenol) 4.4°-Thiobis(3-methyl-6-t-butylphenol) ) 2.2'-thiobis(4-methyl-6-t-butylphenol) 1.3.5-trimethyl-2,4,6-1~lis(3,
5-di-t-butyl-4-hydroxyphenyl)benzylbenzene, 1.3.5-tris(2-methyl-4-hydroxy-5
-t-butylphenol)methane, tetrakis[methylene 3,5-di-tert-butyl-4-hydroxyphenyl)propionate comethane 1,
β-(3,5-tert-butyl-4-hydroxyphenyl)propionic acid alkyl ester, 2.2'-oxamidobis[ethyl-3-(3,5-tert-butyl-4-hydroxyphenyl)propionate] As the β-(3,5-tert-butyl-4-hydroxyphenyl)propionic acid alkyl ester, an alkyl ester having 18 or less carbon atoms is particularly preferable. 4
-di-t-butyl-4-hydroxyphenyl)propionate comethane, n-octadecyl-3-(4''-hydroxy-3,5-di-1-butylphenyl)propionate, 2,6-di-1-butyl- Leaf cresol, 2.4.
6-1 ~ Lis(3', 5°-di-t-butyl-4'-hydroxybenzylthiono-1,3,5-triazine, 2
, 2'-methylenebis(4-methyl-6-t-butylphenol), 4.4"-methylenebis(2,6-t-butylphenol)
-butylphenol), 2,2'-methylenebis[6
-(1-methylcyclohexyl)P-cresol 1, bis[3,5-bis(4-hydroxy-3-t-butylphenyl)butyric acid coglycol ester, 4,
4”-butylizonbis (6-1-butyl-m-cresol), 1,1.3-tris(2-methyl-4-hydroxy-5-1-butylphenyl)butane, 1,3.5-
Tris(2,6-dimethyl-3-hydroxy-a-t-
butylbenzyl) isocyanurate, L 3.5-tris(3,5-di-1-butyl-4-hydroxybenzyl)-2,4,6-trimethylbenzene, 1.3.5-
Tris(3,5-di-t-butyl-4-hydroxybenzyl)isocyanode, 1,3,5-tris[(3,5
-di-t-butyl-4-hydroxyphenyl)propionyloxyethyl]isocyanurate, 2-octylthio-4,6-di(4-hydroxy-3,5-di-t-butyl)phenoxy-1,3,5 -1 ~ riazine, 4.4
゛-thiobis(6-1-butyl-m-cresol) and the like are used.

These phenolic stabilizers may be used alone or in combination.

In the injection moldable polyolefin composition according to the present invention, the phenolic stabilizer (B) as described above is contained in an amount of 00005 to 5 parts by weight, preferably O, O'l to 5 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 to 0.2 parts by weight. The amount of this phenolic stabilizer (B) is 1
If it is less than 0.005 parts by weight, the effect of improving heat resistance will be low, and if it exceeds 5 parts by weight, not only will the cost of the stabilizer increase, but it will also affect the properties of the resin. For example, it is not preferable because there is a risk that tensile elongation, compatibility, etc. will be impaired.

Organophosphite stabilizer (C) The injection moldable polyolefin composition according to the present invention includes:
In addition to the above-mentioned polyolefin (A>) and phenolic stabilizer (B), an organic phosphite stabilizer (
C).

As the organic phosphite stabilizer, conventionally known stabilizers can be used without particular limitation, but specifically the following compounds are used.

trioctylbosphite, trilauryl phosphite, 1-lysosyl phosphite, octyl-diphenyl phosphite, tris(2,4-di-tert-butylphenyl) phosphite 1-, triphenyl phosphite,
Tris (butoxyethyl) phosphite, tris (nonylphenyl) phosphite 1~, distearyl pentaerythritol diphosphite, tetra (tridecyl) -
Ll, 3-tris(2-methyl-5-tert-butyl-4-hydroxyphenyl)butane diphosphite, tetra(C12-C15 mixed alkyl)-4,4°-isopropylidene diphenyl diphosphite, tetra(tridecyl )−,! , 4'-butylidene bis(3-methyl-
6-tert-butylphenol) diphosphite, tris(3,5-di-tert-butyl-4-hydroxyphenyl)phosphite, tris(mono-dimixed nonylphenyl)phosphite 1~, hydrogenated-4,4°-isopropylidene diphosphite Phenol polyphosphite, bis(octylphenyl) bis[4,4°-butylidene bis(3
-methyl-6-tert-butylphenol)]・]1
, 6-hexaneol diphosphor 1-phenyl 4,
4°-isopropylidenediphenol/pentaerythritol diphosphite 1-butyl-4-methylphenyl)
Pentaerythritol diphosphite, tris[4,4
'-isopropylidene bis(2-tert-butylphenol)] phosphite 1 ~, phenyl diisodecyl phosphite, di(nonylphenyl) pentaerythritol diphosphite, tris(1,3-di-stearoyloxyisopropyl) phosphite, 4 , 4°-isopropylidene bis(2-tert-butylphenol)・
Di(nonylphenyl)phosphite, 9,10-di-hydro-9-oxa-9-oxa-10-phosphnafunanthrene-10-oxide, tetrakis(2,4-di-tert-butylphenyl)-4, Examples thereof include 4'-biphenylene diphosphite 1 and the like.

Further, as the bis(dialkylphenyl)pentaerythritol diphosphite ester, a spiro type represented by the following formula (1) or a cage type represented by the formula (2) are also used. Mixtures of both isomers are usually used most often for economic reasons arising from the process of preparing such phosphite esters.

Here, R1 and R2 are preferably alkyl groups having 1 to 9 carbon atoms, particularly tert-butyl groups among branched alkyl groups, and the substitution position in the phenyl group is 2.
, 4th position is most preferred. A suitable phosphite ester is bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite.

These organic phosphite stabilizers may be used alone or in combination.

In the injection moldable polyolefin composition according to the present invention, the organic A-sulfite stabilizer (C) as described above is added to
It is used in an amount of 0.05 to 5 parts by weight, preferably 0.01 to 0.5 parts by weight, more preferably 0.05 to 0.2 parts by weight. If the amount of the organic phosphor 1 to system stabilizer (C) is less than 0.005 parts by weight based on 100 parts by weight of the polyolefin (A), it is not preferable because the effect of improving heat resistance is low; Exceeding this is not preferable as it may lead to instability.

Organic thioether stabilizer (D) The injection moldable polyolefin composition according to the present invention includes:
In addition to the polyolefin (A), phenolic stabilizer (B), and organic sulfite stabilizer (C) as described above, it contains an organic thioether stabilizer (D>).

As the organic thioether stabilizer, conventionally known ones can be used without particular restriction, but specifically (
The following compounds are used.

Polyhydric alcohols of sialyl thiodipropionates such as dilauryl, similisdel, and distearyl and alkylthiopropionic acids such as butyl, octyl, lauryl, and stearyl (e.g., glycerin,
Examples include esters of rimethylolethane, 1-rimedylolpropane, pentaerythritol, trishydroxyethyl isocyanurate (for example, pentaerythritol tetralauryl thiopropionate).

More specifically, dilaurylthiodipropionate,
Simyristylthiodipropionate, distearylthiodipropionate, crylstearylthiodipropionate, distearylthiodibutylene-1, etc.

These organic thioether stabilizers may be used alone or in combination.

In the injection moldable polyolefin composition according to the present invention, the organic thioether stabilizer (D>) as described above is 09005 to 09005 to 100 parts by weight of the polyolefin (A).
It is used in an amount of 5 parts by weight, preferably 0.01 to 0.5 parts by weight, more preferably 0.05 to 0.2 parts by weight. If the amount of this organic thioether stabilizer (D> is less than 0.005 parts by weight based on 100 parts by weight of polyolefin (A), the effect of improving heat resistance will be low, which is undesirable; on the other hand, if it exceeds 5 parts by weight) This is not preferable 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.

The first injection moldable polyolefin composition according to the present invention comprises the above-mentioned polyolefin (A>), a phenolic stabilizer (B), an organic phosphite stabilizer (C),
Since it consists of an organic thioether stabilizer (D>), it has excellent thermal stability during injection molding and long-term heat resistance stability, but the above components (A), (B), (C) and (D
>, when metal salt (E) of higher fatty acid (described later) is added,
A polyolefin composition can be obtained which has excellent thermal stability during injection molding and long-term thermal stability.

Metal salt of higher fatty acid (E) The injection moldable polyolefin composition according to the present invention includes:
In addition to the above polyolefin (A), phenol stabilizer (B), organic phosphite stabilizer (C) and organic thioether stabilizer (D>), it contains a metal salt of higher fatty acid (E). There is.

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 lydium salts are used. Specifically, the following compounds are used.

Magnesium stearate, magnesium laurate,
Magnesium 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 (E) 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 ~0.1 part by weight, more preferably 0.05-0.2 part by weight. The amount of metal salt (E) of this higher fatty acid is the 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 the properties of the resin, such as tensile elongation and compatibility, may be impaired. .

The injection moldable polyolefin composition according to the present invention includes the above-mentioned components (A>, (B), (C) and (D), or (A>, (B), (C), (D), 15 and (E)
In addition, heat stabilizers, weather stabilizers, pigments, dyes, lubricants, inorganic fillers or reinforcing agents such as carbon black, talc, and glass fibers, flame retardants, neutron shielding agents, etc. are usually added and mixed with polyolefins. Compounding agents may 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. In addition, injection molding can be performed without delamination of the molded product, which occurs when using a general-purpose injection molding machine, which is a major drawback of ultra-high molecular weight polyolefins, and the molded product can be molded without delamination. It also has excellent thermal stability and long-term heat resistance, so 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 wear resistance, but also in home appliances and OA equipment. It can be used for various purposes including sliding parts and materials such as.

[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 unless they go beyond the gist of the invention.

Example 1 <Catalyst Preparation> Anhydrous magnesium chloride 47.6y (0.5 mol), decalin 0.2.5 Jl and 2-ethylhexyl alcohol 0.2.1 (1.5 mol) were mixed at 130°C with 2 After heating for a period of time to make a homogeneous solution, 7.4 d of ethyl benzoate (
50 mmol) was added. This homogeneous solution was added dropwise to 1.5 fl of T i CI a maintained at -5° C. over 1 hour with stirring.

A 3.0 glass separable flask was used as the reactor, and the stirring speed was 950 rl)m.

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 thoroughly washed with hexane to obtain a highly active finely powdered titanium catalyst component. The catalyst component contained 3.8% by weight of titanium atoms.

<Polymerization> Internal volume 2'20. Continuous polymerization was carried out using a continuous two-stage polymerization apparatus in which two polymerization tanks of 1 liter were connected in series.

130.11 of n-hexane was added to the first stage polymerization tank (hereinafter abbreviated as polymerization tank 1) of the continuous two-stage polymerization apparatus, and
The temperature was raised to 0'C. n-hexane at a rate of 35 fJ/hour, 1-ethylaluminum at a rate of 45 mM/hour, titanium catalyst at a rate of 1.0 milligram atom/hour as titanium atoms, and ethylene gas at 4.3N7
F! was continuously introduced into the polymerization tank 1 at a rate of 1/hour. A pump was used to send the polymerization mixture slurry in polymerization tank 1 to a subsequent polymerization tank (hereinafter abbreviated as polymerization tank 2), and the level of polymerization tank 1 was maintained at 130ρ. At that time, the polymerization pressure in polymerization tank 1 was 4
．． It was 7Ky/~G.

In the polymerization tank 2, n-hexane was added to the polymerization mixture slurry sent from the polymerization tank 1 at a rate of 259/hour.
Ethylene gas was introduced continuously at a rate of 11.2 Nm/h. 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 extracted from the lower part of the polymerization tank 2 using a timer valve, and the level of the polymerization tank 2 was maintained at 120.0.

The polymerization temperature in polymerization tank 2 was 85°C, and the polymerization pressure was 7.2 t'J.
The obtained polymer and solvent were separated by a centrifuge and dried under a N2 stream.

The [η] and content of each component of the obtained polyolefin (A>), as well as the [η] and melting torque of the composition were measured by the following methods.

[η]: Intrinsic viscosity measured in a decalin solvent at 135°C Melting torque (T): 9/cm at a temperature of 240°C and a pressure of 5 using a JSR culastometer (manufactured by Kinsai Kikai Kogyo)
, amplitude ±3°C, frequency 5, stress of the sample in the molten state measured by CPM 1~100% by weight Injection molding> 100 parts by weight of the polyolefin (A) and tetrakis [methylene (3 ,5
-di-tert-butyl-4-hydroxy)hydrocinnamate comethane (trade name IRG, ANOX, 1010
．． B (manufactured by Ciba Geigy ■) 0.1 part by weight, as organic phosphite stabilizer (C), tetrakis (2,4-di-tert-butylphenyl)-4,4-
0.1 part by weight of biphenylene siphosphite (trade name: Sandstap l"EPQ, manufactured by 5ANDOZ) and distearlythiodipropionate (trade name, DSTP "Yoshitomi", manufactured by Yoshitomi Pharmaceutical Co., Ltd.) as an organic thioether stabilizer. After mixing with 0.1 part by weight in a Henschel mixer, this composition was supplied to a L/D-28, 25 mm single screw extruder, and kneaded by passing once at 190'C and 50 ppm.
Granulated.

The granulated pellets 1~ are molded into an injection molding machine (manufactured by Toshiba Corporation ■5-
50> under the following conditions (130X120X
2m> was formed and then cut to create a test piece.

Injection molding conditions Cylinder temperature ('C): 200/230/270
/270; Injection pressure<K'j/c folding): Primary/Secondary-
1000/800 cycles (sec): Primary/Secondary/Cooling-5/3
/25; Injection speed (-): 2/10 SCRFW rotation speed (rpm): 97; Mold temperature (℃): Water cooling (32℃) Sample placed in air at 130℃ 500.1000.3000
．． After being left for 5000 hours, the long-term 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 mm and 1 minute, and elongation at break (El: %) was determined.

Examples 2 to 4 In Example 2, 100 parts by weight of the polyolefin (A) obtained in Example 1, 0.1 part by weight of the phenolic stabilizer (B) used in Example 1, and an organic thioether-based 0.1 part by weight of the stabilizer (D), and tris(mixed mono&dinolylphenyl) phosphite (trade name, mark 329) as the organic phosphite stabilizer (C).
0.1 part by weight (manufactured by Adeka Argus Chemical Co., Ltd.) was added to the solution.

In Example 3, a phenolic stabilizer (B) was added to the polyolefin (A>100 parts by weight) obtained in Example 1.
), 0.1 part by weight of 2,6-di-t-butyl-4-methylphenol (trade name, 5ANTONOXR, manufactured by MONSANT), and the organic phosphite stabilizer (C) used in Example 1, 0 .1 parts by weight of an organic thioether stabilizer (D>0.1 parts by weight) were added.

In Example 4, the poly=50 obtained in Example 1
- Olefin (A>100 parts by weight, 0.1 parts by weight each of those used in Example 1 as a phenolic stabilizer (B) and an organic phosphite stabilizer (C), and an organic thioether stabilizer ( As D>, 0.1 part by weight of dilauryl thiodipropionate (trade name, DLTP r Yoshitomi, manufactured by Yoshitomi Pharmaceutical Co., Ltd.) was added.

Other procedures were carried out in the same manner as in Example 1, and long-term heat resistance stability was evaluated. These results are shown in Table 1.

Examples 5-8 The same procedure as in Example 1 was carried out except that 0.12 parts by weight of calcium stearate was added as a higher fatty acid metal salt (E) to each of the same compositions as in Examples 1-4, and long-term heat-resistant stability was achieved. The gender was evaluated. These results are shown in Table 1.

For 100 parts by weight, two types of phenolic stabilizers (B) and two types of organic phosphite stabilizers (C) used in Examples 1 to 8, two types of organic thionythyl stabilizers (D>), and metal salts of higher fatty acids (one type of D>, total 7
0.3 parts by weight of each type was added individually. Other than this, the experiment was carried out in the same manner as in Example 1, and the long-term heat resistance stability was evaluated. These results are shown in Table 1.

Furthermore, each of the wires used in Examples 1 to 8 and Comparative Examples 1 to 7 was assembled and granulated. [η] and melting torque were measured for each of the pellets 1 to 5 times that were granulated in the same manner as in Example 1, and the thermal stability during molding of the composition was evaluated. These results are shown in Table 2.
Shown below.

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. - cm or less polyolefin: 100 parts by weight, (B) phenolic stabilizer: 0.005 to 5 parts by weight, (C) organic phosphite stabilizer: 0.005 to 5 parts by weight, (D ) An injection moldable polyolefin composition comprising: 0.005 to 5 parts by weight of an organic thioether stabilizer. 2) (A) (i) An ultra-high molecular weight polyolefin with an intrinsic viscosity of 10 to 40 dl/g measured in a 135°C decalin solvent and an ultrahigh molecular weight polyolefin with an intrinsic viscosity of 0 as measured in a 135°C decalin solvent.
．． 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. - cm or less polyolefin: 100 parts by weight, (B) phenolic stabilizer: 0.005 to 5 parts by weight, (C) organic phosphite stabilizer: 0.005 to 5 parts by weight, (D 1.) An injection moldable polyolefin composition comprising: 0.005 to 5 parts by weight of an organic thioether stabilizer; and 0.005 to 5 parts by weight of a metal salt of a higher fatty acid. 3) 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 organoaluminum 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. 3. An injection moldable polyolefin composition according to claim 1 or 2, which is produced by a multi-step polymerization process to produce a polyolefin having a molecular weight to a high molecular weight.