JPH01161033A - Polyolefin gear - Google Patents

Abstract

PURPOSE:To obtain the subject gear of low noise having excellent wear resistance, heat resistance and abrasion resistance and being suitably usable for power transmission of a small precision instrument, etc., by injection-molding a compsn. consisting of an ultrahigh-MW polyolefin and a low-MW-high-MW polyolefin. CONSTITUTION:A polyolefin gear is obtd. by injection-molding a polyolefin compsn. 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-MW-high-MW polyolefin 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 wt. of both component A and B, and which contains at least a polyolefin having an intrinsic viscosity [eta]c of 3.5-15dl/g measured in decalin solvent at 135 deg.C and a dissolution torque T of 4.5kg.cm or lower. Since this process, makes it possible to easily obtain the gear by injection molding without spoiling excellent mechanical properties that the component A essentially has and without causing delamination, it is possible to obtain with relatively low cost a gear having excellent wear resistance, heat resistance, impact resistance and abrasion characteristics.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a gear with excellent wear resistance, heat resistance, or slidability, and more specifically, to a gear for small precision equipment such as a video tape recorder (VTR). This invention relates to a low-noise polyolefin gear that is preferably used for power transmission.

BACKGROUND OF THE INVENTION Technical Priority and Problems Conventionally, gears made of metal such as aluminum or stainless steel have been known as gears for power transmission. However, metal gears are heavy, especially when used in precision equipment such as VTRs, video cameras, office automation (OA) equipment, toys, and other equipment. This increased the weight of the entire device, which was undesirable. Further, in the case of such a metal gear, the cutting process at the time of manufacturing the gear is complicated, and there is a possibility that the manufacturing cost will increase.

In order to eliminate the inconvenience of having metal gears like this,
Recently, gears like this have started to be molded using plus books. As the plastic constituting such a gear, engineering plastics such as polyacetal resin, polyimide resin, and polycarbonate resin can be considered.

However, such engineering plastics such as polyacetal resins and polyimide resins have problems in that they are expensive, inferior in economic efficiency, and have insufficient sliding properties. Therefore, in practice, gears made of relatively inexpensive nylon 12 or polyester rubber coated with molybdenum to improve sliding properties to some extent have been widely used in precision equipment such as VTRs and other equipment.

However, gears made of polyester rubber coated with molybdenum still cannot be said to be superior in terms of wear resistance, heat resistance, and sliding properties, resulting in wear and tear on the gear teeth and damage to the inside of the device. There was a risk that the meshing U of the gears would deteriorate due to a rise in temperature, etc., which could cause noise generation.

In order to overcome these inconveniences, it is conceivable to mold gears used in such sensitive equipment using ultra-high molecular Q polyolefin.

Ultra-high molecular weight polyolefins, such as ultra-high molecular weight polyethylene, have superior impact resistance, heat resistance, abrasion resistance, sliding properties, chemical resistance, tensile strength, etc., compared to general-purpose polyolefins such as general-purpose polyethylene. It is conceivable to use it as a power transmission gear in various precision instruments. 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 a rod shape at extremely low speed.

If ultra-high molecular weight polyethylene, which has poor melt flowability, is molded into a gear shape using normal injection molding,
During the process of filling the mold cavity with resin, a shear fracture flow occurs, and the resulting molded product causes mica-like layer delamination.
Not only has it not been possible to obtain a molded product having the excellent properties of ultra-high molecular weight polyethylene, but the result has always been that it is inferior to gears molded from general-purpose polyethylene.

Purpose of the Invention The present invention has been made in view of the above circumstances, and is capable of being injection-molded without impairing the excellent mechanical properties originally possessed by ultra-high molecular weight polyolefin and without causing delamination. It can be molded, does not require a molybdenum coating to increase occupancy, is relatively inexpensive, and has abrasion resistance that is particularly suitable for use in power transmission in various precision instruments. The purpose is to provide gears with excellent heat resistance, impact resistance, and sliding properties, and low noise.

SUMMARY OF THE INVENTION In order to achieve the above objects, the polyolefin gear according to the present invention comprises an ultra-high molecular weight polyolefin having an intrinsic viscosity of 10 to 40 dβ/g as measured in a decalin solvent at 135°C and 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, Q, 1 as measured by (ii) Intrinsic viscosity measured in decalin solvent at 135°C [
η]. is in the range of 3.5 to 15dρ/9, and (iii
) %ij is+ is obtained by injection molding a polyolefin composition containing at least a polyolefin having a melting torque T of 4.5 Kg·cm or less.

According to such a polyolefin gear according to the present invention, a polyolefin composition can be injection molded without impairing the excellent mechanical properties originally possessed by ultra-high molecular weight polyolefin and without causing delamination. It is possible to obtain gears with excellent wear resistance, heat resistance, impact resistance, and movement at a relatively low cost.

However, according to the present invention, the polyolefin gear itself obtained by injection molding a polyolefin composition has sufficient snow movement, so there is no need to coat it with molybdenum to improve movement. At the same time, there is no need to separately supply or impregnate a lubricant. Furthermore, since the polyolefin gear according to the present invention has excellent abrasion resistance, heat resistance, impact resistance, and sliding properties, it is easy to wear the tips of the gear teeth and cause temperature rise inside the device. This prevents the gears from becoming misaligned even if the gear is moved, and noise can be suppressed as much as possible.

Detailed description of the invention The present invention will be specifically explained below.

The polyolefin gear according to the present invention can be used, for example, in a VTR.
It is preferably used for power transmission in small devices such as, etc., and can be obtained by injection molding, for example, a polyolefin composition containing at least the polyolefin (A) 8 shown below in a mold.

Polyolefin (A) The polyolefin (A>) used in the present invention consists of an ultra-high molecular weight polyolefin and a low molecular weight or high molecular weight polyolefin. explain.

135 of the ultra-high molecular weight polyolefin used in the present invention
The intrinsic viscosity [η] measured in °C decalin solvent is 10
-401Ω/3, preferably 15-35d, fl/g. If this intrinsic viscosity [η] is less than 10 dfl/g, the mechanical properties of the gear as an injection molded product tend to deteriorate, which is undesirable.On the other hand, if it exceeds 40 dρ/g, the gear as an index molded product tends to deteriorate. This is undesirable because it deteriorates the appearance, causes flow marks, and causes delamination.

Low molecular weight or polymer used in the present invention; intrinsic viscosity of polyolefin measured in decalin solvent at 135°C [η
] h is 0.1 to 5d, Il/y, preferably 0.5 to
It is necessarily in the range of 3dρ/g. This intrinsic viscosity [η]h is 0.
If it is less than 1 6977, the molecular weight is too low and there is a risk of bleeding on the surface of the gear as an injection molded product, which is undesirable. On the other hand, if it exceeds 5 dρ/zo, the melt fluidity will decrease, so it is not suitable for general-purpose polyethylene injection. It is difficult to use the molding machine as it 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-dezene, 1-dodecene, 4-methyl-1-pentene, 3-methyl-1-pentene, etc.
- Consists of homopolymers or copolymers of olefins. Of these, one homopolymer of ethylene, or ethylene and four
A copolymer consisting of α-olefin and ethylene as a main component is desirable.

In the polyolefin constituting the gear according to the present invention, the ultrahigh molecular weight polyolefin and the low molecular weight to high molecular weight polyolefin are such that the ultrahigh molecular weight polyolefin accounts for 15 to 40% by weight based on the total weight of both polyolefins. In other words,
The low molecular weight to high molecular weight polyolefins are present in an amount of 85 to 60% by weight based on the total weight of both polyolefins. The ultra-high molecular weight polyolefin as described above has a weight of 20% based on the total weight of both polyolefins.
Preferably, it is present in a proportion that accounts for ~35% by weight. Ultra-high molecular weight polyolefin polishing is 15%
If it is less than 40% by weight, it is undesirable because the mechanical properties of the resulting gear as an injection molded product tend to be inferior.On the other hand, if it exceeds 40% by weight, delamination will occur in the gear as an injection molded product. As a result, a molded article with good mechanical properties cannot be obtained, which is not preferable.

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] measured in a decalin solvent at 5°C is 3.
It is in the range of 5 to 15 dll/9, and the melting torque T (K9
・cm) is now 4.5! It is below j-cm. Note that the melting torque T here is determined using a JSR Curastmeter (manufactured by Imanaka Kikai Kogyo KK) at a temperature of 240'C and a pressure of 5 kg.
/crA, amplitude 3° frequency 5 Values measured under CPII conditions.

[η] above. If it is less than 3.5d, ll/y, it is not preferable because the mechanical strength, especially the wear resistance, of the gear as an injection molded product to be obtained may be poor; on the other hand, [η].

If it exceeds 15d, 1/g, delamination occurs in the gear as an injection molded product, resulting in a decrease in mechanical strength such as wear resistance, which is not preferable.

Moreover, if the melting torque T exceeds 4.5 kg·cm, it is not preferable because the screw will not bite into the normal screw in molding I, 1, and injection molding will not be possible with a general-purpose injection molding machine.

The polyolefin used in the present invention is preferably [η
]. 4. Must be in the range of O to 10d, Q/y.

The polyolefin used in the present invention can also be prepared by blending an ultra-high molecular weight polyolefin and a low-molecular weight or high-molecular weight polyolefin in the proportions described above, but according to the studies of 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 a specific highly active solid titanium catalyst component and an organoaluminum compound catalyst component, have excellent properties. I found out that I have it.

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. In other words, in at least one polymerization step, the intrinsic viscosity is 10 to 40 d.
The ultra high polymer of β/U produces polyolefin, and in the other polymerization step A3, the olefin is polymerized in the presence of hydrogen, and the intrinsic viscosity is 0.1-5d, and the low molecular weight to high molecular weight of Il/di. Produce polyolefins.

The specific Daegler-type catalyst used is essentially a specific type of catalyst 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, for example, a 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 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 small amount of monocarboxylic acid ester of about 0.01 to 0.2 mole per mole of magnesium chloride is allowed to coexist and strong stirring conditions are applied. By performing the precipitation below,
A highly active finely powdered titanium catalyst component can be prepared. Further, 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 by weight, halogen/titanium (atomic ratio) is about 5% to about 90%, magnesium/
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 organoaluminum compound of the same molecular weight are added 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 trialkylaluminiums such as triethylaluminum and trialkylaluminum, siaaluminum chlorides such as diethylaluminum chloride and diisobutylaluminum chloride, and alkylaluminum sesquicentres such as ethylaluminum sesquichloride. Chloride 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 equipments 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 carry out a multi-step method using a batch polymerization method in one polymerization tank. It is necessary to produce a specific 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 a multiple stage of two or more stages. It is preferable to produce an ultra-high molecular weight polyolefin in the first stage polymerization step because it facilitates the polymerization process and allows easy control of the physical properties of the resulting polyolefin. In the polymerization step, 15 to 4 of the polyolefin used in the present invention is
0% is the intrinsic viscosity [η], (13 in decalin solvent
It is necessary that the ultra-high molecular weight polyolefin accounts for 10 to 40 d, Q/g (value measured at 5°C), and roughly 18 to 37% by weight of the polyolefin used in the present invention. , especially 21 to 35% by weight, the intrinsic viscosity [η] U is 15 to 35 d, I)/, especially 18 to
Preferably, it is comprised of an ultra-high molecular weight polyolefin having a molecular weight of 30 dfJ/g. In this polymerization process, the intrinsic viscosity [η
] is less than 10 dfJ,/g, and even if the ultra-high molecular weight polyolefin produced in the polymerization step
Even outside the flQ% range, 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 step 1 of synthesis to produce 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 1f of medium.
0 milligram atom, preferably about 0.005 to about 10 milligram atom, organoaluminum compound catalyst component (b)
, 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 avoid producing the ultra-high molecular weight polyolefins generally ranges from about -20 to about 120'C, preferably from about 0 to about 100'C, and most preferably from about 5 to about 95C. Further, the pressure during the polymerization reaction is 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 Kg/crt+, preferably from atmospheric pressure to about 50 KFJ/crA. . In addition, the polymerization time in the polymerization step may be set so that the prepolymerized polyolefin is produced in an amount of about 10,009 or more, preferably about 20,009 or more per milligram atom of titanium in the highly active titanium catalyst component. . In addition, J
3. In order to produce the ultra-high molecular weight polyolefin, the polymerization reaction is preferably carried out 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 cyclopentane and cyclohexane; Aromatic hydrocarbons such as benzene, toluene, and xylene; Halogenated hydrocarbons such as dichloroethane, methylene chloride, and chlorobenzene. ; or a mixture thereof. Particularly desirable is the use of aliphatic hydrocarbons.

In addition, when producing the polyolefin used in the present invention, in addition to the polymerization step for producing the ultra-high molecular weight polyolefin, in the polymerization step for producing the low molecular weight to high molecular weight polyolefin,
A polymerization reaction of the remaining olefin is carried out in the presence of hydrogen. If the polymerization step for producing an ultra-high molecular weight polyolefin is the first step, then the second and subsequent polymerization steps correspond to the polymerization step. When the chassis process is located after the ultra-high molecular weight polyolefin production polymerization process, the polymerization process is supplied with a polyolefin containing the ultra-high molecular weight polyolefin, and the polymerization process is performed in a process other than the ultra-high molecular weight polyolefin production process. When located after the polymerization step, the low-molecular weight to high-molecular weight polyolefin produced in the previous step is fed, and in either case, the polymerization is carried out continuously. At that time, the raw material olefin a3 and hydrogen are usually supplied to the polymerization step. When the chassis process is the first stage polymerization process, a catalyst consisting of the highly active titanium catalyst component (a) and the organoaluminum compound catalyst component (b) is supplied, and the polymerization process is carried out in the second and subsequent stages. In the case of the Φ synthesis step, the catalyst contained in the polymerization product liquid produced in the previous step can be used as it is, or the highly active titanium catalyst component (a) and / Alternatively, it is okay to additionally supplement the organic aluminum compound (b).

The low molecular weight or high molecular weight polyolefin thus obtained is 5 to 70% by weight, preferably 20 to 60% by weight, based on the total oleinoin component polymerized in the entire polymerization process.
, preferably in the range of 25 to 55% by weight.

The hydrogen supply ratio in the polymerization steps other than the ultra-high molecular weight polyolenoin production polymerization step is usually 0.01 to 5.
The amount is in the range of 0 mol, preferably 0.05 to 30 mol.

110 Ultra-polymer suspended polyolefin production Polymerization other than the polymerization process The concentration of each catalyst component in the polymerization product liquid in the polymerization tank where IB rises as much as r is calculated by converting the treated catalyst into titanium atoms per 1 polymerization volume. and about 0.001 to about 0.1 milligram atom, preferably about 0.005 to about 0.1 milligram atom, and the AI/Ti (atomic ratio) of the polymerization system is about 1 to about 10.
00, preferably 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 coexisting for the purpose of controlling 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 100°C.
'C range is preferred. Further, the polymerization pressure is, for example, atmospheric pressure to about 100 kg/cr7r, particularly atmospheric pressure to about 5 kg/cr7r.
A range of 0 KI/ctA is preferred. The polymerization time is preferably set such that the amount of polymer produced is about 1,000 g or more, particularly preferably about 5,000 g or more, per milligram atom of titanium in the titanium catalyst component.

Polymerization steps other than the hand-combining step for producing an ultra-high molecular weight polyolefin can be similarly carried out by a gas phase polymerization method or by a liquid phase polymerization method. 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 techniques are carried out in the presence of an inert medium diluent, while liquid phase slurry suspension techniques 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 [
η]. However, the melting torque is usually 3.5 to 15 d, il/SJ, preferably 4.0 to 10 d, Qzl, and the melting torque is 4.5'.
The polymerization reaction is carried out in such a way that the thickness is less than or equal to j·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. Behind these α-olefins, ethylene or ethylene and other α-olefins are formed.
- It is preferable to apply the above multi-step polymerization method to a method for producing an ethylene polymer, which is a copolymer with an olefin and necessarily has an ethylene component as a main component.

Sliding Filler (B) A polyolefin composition suitable for producing the polyolefin gear according to the present invention may contain a sliding filler (B) in addition to the above polyolefin (A>). good.

As the sliding filler (B), conventionally known sliding fillers can be used without particular limitation, but specifically the following compounds are used.

Graphite powder, polytetrafluoroethylene resin (
PTFE), tetrafluoroethylene-hexafluoropropylene copolymer resin (FEP), tetrafluoroethylene-perfluoroalkoxyethylene copolymer resin (PFA), trifluorochloroethylene resin (PCTFE), tetrafluoroethylene Ethylene-ethylene copolymer resin (ETFE), fluororesin powder such as vinylidene fluoride resin, molybdenum fluoride powder, molybdenum sulfide powder, titanium oxide powder, polyphenylene sulfide resin powder, etc.

It is preferable that these one-permeability fillers (B) are used in powder form, and the particle size thereof is 0.01 to 500μ7r.
L is preferably 0.05 to 100μ7rL.

In the polyolefin composition constituting the gear according to the present invention, the above-mentioned 1-virulent filler (B) is contained in the polyolefin (A>1 to 70 parts by weight, preferably 3 to 70 parts by weight, based on 100 parts by weight). It is preferably used in an amount of 50 mfi parts, more preferably 5 to 30 mfi parts.

Fibrous filler (C) In addition to the polyolefin (A), the polyolefin composition constituting the polyolefin gear according to the present invention contains:
It may also contain a fibrous filler <C).

As the ml filler (C), conventionally known fibrous fillers can be used without particular limitation, but specifically the following are used.

Glass 11i fiber, carbon fiber shoulder f, boron fiber, butanoic acid kaliwis h-1 metal fiber such as aluminum fiber, stainless steel i navy blue, etc.

Asbestos, aramid fiber, polyester fiber, polyamide fiber, etc.

These fibrous fillers (B) have a fiber diameter of 1 to 30
μm is preferably 5 to 20 μm, and the fiber length is 1000 μm.
~10,000 μm, preferably 3,000 to 6,000 μm, and the aspect ratio is 33 to 10,000, preferably 15
It is desirable that the value be between 0 and 1200.

In the polyolefin composition constituting the gear according to the present invention, the fibrous filler (C) as described above is contained in an amount of 1 to 701 parts by weight, preferably 3 to 50 parts by weight, based on 100 parts by weight of the polyolefin (A). It is preferably used in a can with 5 to 30 layers.

Phenolic stabilizer (D) In addition to the polyolefin (A), the polyolefin composition constituting the polyolefin gear according to the present invention contains:
Even if it contains a phenolic stabilizer (D>).

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, 2.
6-di-cyclohexyl-4-methylphenol, 2.
6-diisopropyl-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-edyru-6-[-octylphenol, 2-isobutyl-4-edyru-6-t- Hexishif-1-nor, 2-cyclohexyl-4-n-butyl-6-imbr'
Pyrphenol, tetrakis[methylene (3,5-di-t-butyl-4-
hydroxy)hydrocinnamej~]methane, etc.

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

2.2-Methylenebis(4-methyl-6-[-butylphenol) 4.4-Butylidenebis(3-methyl-6-[-butylphenol) 4.4-Thiobis(3-methyl-6-t-butylphenol) 2. 2-thiobis(4-methyl-6-t-butylphenol) 1.3.5-trimethyl-2,4,6-tris(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, alkyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate Ester, 2,2-oxamidobis[ediru 3- (3,5-
Examples include di-tert-butyl-4-hydroxyphenyl) propionate. As the alkylnisder β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, alkyl esters having 18 or less carbon atoms are particularly preferred. Also, tetrakis[methylene(2,4-
di-t-butyl-4-hydroxyphenyl) propionate comethane, n-octadecyl-3-(4-hydroxy-3,5-di-t-butylphenyl) propionate, 2,6-di 2, 4.6-
Tris (3°, 5"-di-t-butyl-4"-hydroxybenzylthiono-1,3,5-triazine, 2,2"-methylenebis(4-methyl-6-t-butylphenol), 4. 4'-methylenebis(2,6-di-t-butylphenol), 2,2"-methylenebis[6-(1
-Methylcyclohexyl〉P-cresol], bis[3
, 5-bis(4-hydroxy-3-t-butylphenyl) butylic acid] glycol nisder, 4,4-butylidene bis(6-1-butyl-m-cresol),
1,1.3-l~lis(2-methyl-4-hydroxy-
5-t-butylphenyl)butane, 1,3.5-tris(2,6-dimethyl-3-hydroxy-4-t-butylbenzyl)isocyanurate, 1,3. '5-Tris (
3,5-di-t-butyl-4-hydroxybenzyl)-
2,4,6-trimethylbenzene, 1,3,5-tris(3,5-di-t-butyl-4-hydroxybenzyl)
Isocyanudo, 1,3,5-tris[(3,5-di-
t-Butyl-4-hydroxyphenyl)propionyloxyedyl]isocyanurate, 2-octylthio-4
,6-di(4-hydroxy-3,5-di-t-butyl)
Phenoxy-L3,5-triazine, 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 polyolefin composition constituting the gear according to the present invention, the phenolic stabilizer (B) as described above is added in an amount of 0.00 to 1 part of 100 fflff of the polyolefin (A).
It is used at 5 to 5 parts, preferably 0.01 to 0.5 parts, and more preferably 0.05 to 0.2 parts.

Organic 4-sulfite stabilizer (E) The polyolefin composition constituting the polyolefin gear according to the present invention contains, in addition to the polyolefin (△),
Front right) ΔSphere 1 may also contain a system stabilizer (C).

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

Trioctyl phosphite, trilaurylbosphite, tridecyl phosphite, octyl-diphenyl phosphite 1~, tris(2,4-di-tert-butylphenyl) phosphite, trifyl phosphite 1~,
Tris (butoxyethyl) small sulfite, 1-lis (nonylphenyl) phosphite, distearyl pentaerythritol diphosphite, tetra (tridecyl) -
1,1,3-tris(2-methyl-5-tert-butyl-4-hydroxyphenyl)zotanediphosphite,
Tetra (012-C15R combined alkyl) -4,4'-
Isopropylidene diphenyl diphosphite, Te1-U(tridecyl)-4,4°-butylidenebis(3-methyl-6-tert-buburphenol) diphosphite, Tris(3,5-di-tert-Bu1-4- hydroxyphenyl)bosphite, tris(mono-dimixed nonylphenyl)phosphite, hydrogenated-4,4°-isopropylidene diphenol polyphosphite, bis(
octylphenyl)・bis[4,4°-butylidenebis(3-methyl-6-tert-butylphenol)]・
1,6-hexaneol diphosphite, phenyl 4
．． 4'-Isopropylidenediphenol pentaerythritol diphosphite, bis(2,4-ditert)
-butylphenyl)pentaerythritol diphoseye 1
~, bis(2,6-tert-butyl-4-methylphenyl)pentaerythritol diphosphite, tris[4,4-isopropylidenebis(2-tert-butylphenol)]phosphite, phenyl diisodecyl phosphite, Di(nonylphenyl)pentaerythritol diphosphite, tris(1,3-di-stearoyloxyisopropyl)phosphite, 4,4°
-isopropylidene bis(2-tert-7dylphenol) di(nonylphenyl)bosfuy 1-. 9,1
0-di-hydro-9-oxa-9-oxa-10-phosphaphenanthrene-10-oxide, Te1-rakis (2,4-di-tert-butylphenyl)-4,4°
- Biphenylene diphosphite 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. In general, mixtures of both isomers are most often used for economic reasons arising from the process of preparing such phosphite esters.

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

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

In the polyolefin composition constituting the gear according to the present invention, an organic sulfite stabilizer (C) such as -F is added in an amount of 0.00% per 100 parts by weight of the polyolefin (A>100 parts by weight).
5 to 5 hanging parts, preferably 0.01 to 0.5 ffi♀ part, more preferably.

It is used in an amount of 0.05 to 0.2 parts by weight.

Dioether stabilizer (F) The polyolefin composition constituting the polyolefin gear according to the present invention contains, in addition to the polyolefin (A),
It may also contain an organic thioether stabilizer (F).

As the organic thioether stabilizer, conventionally known stabilizers can be used without particular limitation, or specifically, the following compounds can be used.

Polyhydric alcohols of dialkylthiodipropionic acids such as dilauryl, similisdel, and disodearyl, and alkylthiopropionic acids such as boubleu, octane, lauryl, and ste)noryl (e.g., glycerin,
1 to rimebrolethane, trimethylolpropane, pentaerythritol, trishydroxynibruisocyanurate) (for example, pentaerythritol detralauryl thiopropionate).

More specifically, dilaurylbu-A dipropionate, dimyristylthiodibropine Δ1~, cys-deryl thiodibropionate, lauryl sularyl dipropionate, disderyl thiodibutyrate, and the like.

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

In the polyolefin composition constituting the gear according to the present invention, the above-described stabilizer (F) is:
O8O○5 for 100 heavy parts of Porin Refine (A)
It is used in an amount of up to 5 parts by weight, preferably 0.01 to 05 parts by weight, and more preferably 0.05 to 0.2 parts by weight.

In the polyolefin composition constituting the gear according to the present invention,
In addition to the above-mentioned polyolefin (A), if a phenolic stabilizer (D), an organic phosphite stabilizer (F), an organic dioether stabilizer (1=), or a plurality of these is included, Q = j The thermal stability of the extrusion molding mouth and the long-term heat resistance stability are improved, but when the metal salts of higher fatty acids (G), which will be described briefly below, are added as a stabilizer, the thermal stability during extrusion molding is further improved. A gear made of poly-4-refin, which has excellent hardness a'3 and long-term heat resistance stability, can be obtained.

Metal salt of higher fatty acid (G) The polyolefin composition constituting the gear according to the present invention is
In addition to the polyolefin (Δ), it contains a higher fatty acid metal salt (G).

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, magnesium laurate,
Sodium palmitate, sodium stearate, calcium oleate, calcium laurate, potassium stearate, barium A, barium laurate, barium araxinate, barium behenate, stearin M + lead, zinc oleate, zinc laurate, stearic acid Sodium, sodium stearate, sodium palmitate, ll-thorium laurin, potassium stearate, potassium laurate, calcium 12-hydroxystearate, etc.

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

In the polyolefin composition constituting the gear 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 a whistle of ~0.5 fold Q part, more preferably 0.05 to 0.2 fold ω part.

J3, in the present invention, gear 4g: In addition to the above-mentioned components, the constituting polyolefin composition usually contains polyolefins such as heat stabilizers, weather stabilizers, pigments, dyes, lubricants, flame retardants, neutron shielding agents, etc. Compounding agents that are added to and mixed with can be added within a range that does not impair the purpose of the present invention.

As described in detail, the polyolefin gear according to the present invention has excellent mechanical properties τ18 inherent to ultra-high molecular weight polyolefins, and without causing delamination. Since it can be easily obtained by injection molding a polyolefin composition, it is possible to produce gears with excellent wear resistance, heat resistance, impact resistance, and rotational performance.
It becomes possible to do JD relatively cheaply. Moreover, according to the present invention, a single polyolefin gear made by injection molding a polyolefin composition is sufficient.
Since it has monodynamic properties, there is no need for molybdenum coating to improve opening properties, and there is no need to separately supply or impregnate lubricant.Furthermore, the polyolefin gear according to the present invention has wear resistance, Wi Because it has excellent heat resistance, shock resistance, and 1 behavior, the tips of the gear teeth are worn and coarse, and the meshing of the gears becomes poor due to the warm abrasions inside the equipment. There is nothing to do, and
Noise can also be suppressed as much as possible. So 4j like this:
When the gear is used in various precision devices such as VTRs, it becomes possible to reduce the weight, cost, and noise of these devices.

Agent: Patent Attorney: Shunbetsu Suzuki

Claims (1)

[Claims] 1) Intrinsic viscosity measured in decalin solvent at 135°C is 10
-40 dl/g ultra-high molecular weight polyolefin;
Intrinsic viscosity measured in decalin solvent at 35°C is 0.1-5
dl/g, and (i) the ultra-high molecular weight polyolefin is comprised essentially of a low molecular weight to high molecular weight polyolefin having an
(ii) the intrinsic viscosity measured in decalin solvent at 135°C [
η]_c is in the range of 3.5 to 15 dl/g, and (ii
i) A polyolefin gear obtained by injection molding a polyolefin composition containing at least a polyolefin having a melting torque T of 4.5 Kg·cm or less. 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. The polyolefin gear according to claim 1, which is manufactured by a multi-step polymerization method that produces a polyolefin having a molecular weight to a high molecular weight. 3) The polyolefin gear according to claim 1 or 2, wherein the polyolefin composition contains a slidable filler. 4) Claim 3, wherein the slidable filler is graphite, fluororesin powder, molybdenum fluoride, molybdenum sulfide, or polyphenylene sulfide resin powder.
Polyolefin gears as described in section. 5) The polyolefin gear according to any one of claims 1 to 4, wherein the polyolefin composition contains a fibrous filler. 6) The fibrous filler is glass fiber, carbon fiber,
The polyolefin gear according to claim 5, which is boron fiber, potassium titanate whisker, asbestos, metal fiber, aramid fiber, polyester fiber, or polyamide fiber. 7) The polyolefin gear according to any one of claims 1 to 6, wherein the polyolefin composition contains a stabilizer. 8) The polyolefin gear according to claim 7, wherein the stabilizer is a phenolic stabilizer, an organic phosphite stabilizer, an organic thioether stabilizer, or a metal salt of a higher fatty acid.