JPS6123208B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing olefin polymers. More specifically, the present invention uses a catalyst consisting of a component obtained by contact treatment of a solid magnesium compound, titanium tetrahalide, and an electron-donating compound and an organoaluminum compound to obtain a highly processable polymer. It relates to a method for producing with catalytic efficiency. In recent years, an α-olefin polymerization catalyst has been proposed which is composed of a component in which titanium tetrahalide is supported on a solid magnesium compound carrier and an organoaluminum compound. Although this catalyst has high polymerization activity,
If an attempt is made to directly obtain an olefin polymer with good processability by increasing the catalyst efficiency, that is, the amount of polymer produced per catalyst unit, the proportion of boiling normal heptane extraction residue in the produced polymer decreases. That is, in order to obtain an olefin polymer with good processability, the molecular weight is usually adjusted with hydrogen, but when the high catalytic efficiency polymerization using the above catalyst system is carried out in the presence of hydrogen, boiling normal heptane extraction residue in the produced polymer The percentage of As a result of intensive studies on high catalytic efficiency polymerization using the above-mentioned catalyst system, the present inventors found that the decrease in the proportion of boiling normal heptane extraction residue in the produced polymer may be due to an increase in the amount of amorphous polymer, which is usually thought to be the case. Based on this recognition, we continued to develop a method for producing olefin polymers with good processability while reducing the amount of low molecular weight polymers produced. Upon investigation, it was discovered that a high molecular weight olefin polymer should first be produced with high catalytic efficiency and then degraded to convert it into an olefin polymer with good processability, and the present invention was achieved. That is, the gist of the present invention is to polymerize α-olefin using a component obtained by contact treatment of a solid magnesium compound, titanium tetrahalide, and an electron-donating compound and an organoaluminum compound as a catalyst, and then to perform extraction with boiling normal heptane. It is characterized by obtaining an olefin polymer having a residue ratio of 90% or more and a viscosity average molecular weight of 500,000 or more, and then reducing the obtained olefin polymer until the viscosity average molecular weight becomes less than 400,000. The present invention relates to a method for producing an olefin polymer. To further explain the method of the present invention in detail, the catalyst used in the method of the present invention includes a component obtained by contacting a solid magnesium compound, titanium tetrahalide, and an electron-donating compound, and an organoaluminum compound. As a solid magnesium compound,
Specifically, magnesium dialkholate, magnesium carboxylate, magnesium acetylacetone complex, magnesium halide 6
Heated water salt, that is, the general formula Mg(OH)xCly (where x and y are numbers greater than 0 and less than 2, x+y=2
It is. ) may also be used, but preferred are magnesium halides,
More preferred are Grignard compounds;
It is obtained by reacting at least one compound selected from water, alcohol, phenols, silanol, and polysilanol. Here, the Grignard compound has the general formula
R ¹ MgX (in the formula, R ¹ represents a hydrocarbon group and X represents a halogen atom), specifically, R ¹ is an alkyl, aryl, aralkyl group, etc. having up to 20 carbon atoms. Something like this is used. Particularly preferred are those in which R ¹ is an alkyl group such as methyl, ethyl, propyl, butyl, amyl, hexyl, etc., an aryl group such as phenyl, or an aralkyl group such as benzyl. Moreover, examples of X include chlorine, bromine, and iodine. These Grignard compounds are usually used as ether solutions or ether adducts. Such ethers include diethyl ether, dibutyl ether,
Examples include ethers such as dihexyl ether, dioctyl ether, and tetrahydrofuran. The alcohol or phenol may be a polyhydric alcohol or a polyhydric phenol, but it is usually a monohydric alcohol represented by the general formula R ² OH (wherein R ² represents a hydrocarbon group) or Phenols are used. Specifically, R ² is a hydrocarbon group having up to 20 carbon atoms, such as alkyl,
Examples include aryl and aralkyl groups. Examples include alkyl groups such as methyl, ethyl, propyl, butyl, amyl, hexyl, octyl, 2-ethylhexyl, nonyl, tecyl, aryl groups such as phenyl, and aralkyl groups such as benzyl. As a silanol, the general formula R ³ nSi(OH) ₄ −n
(wherein R ³ represents a hydrocarbon group and n is 1, 2 or 3). Silanol can be easily synthesized, for example, by hydrolyzing a corresponding halide, as shown in the following formula. (C ₆ H ₅ ) ₃ SiCl + H ₂ O → (C ₆ H ₅ ) ₃ SiOH + HCl Specifically, R ³ is alkyl, cycloalkyl, cycloalkenyl, aryl, aralkyl, alkaryl, and cycloaralkyl having up to 20 carbon atoms. Examples include groups. Particularly preferred are alkyl groups such as methyl, ethyl, propyl, butyl, amyl, hexyl, heptyl, octyl, and decyl, aryl groups such as phenyl, and aralkyl groups such as benzyl. In addition, n can be 1, 2 or 3, but from the viewpoint of silanol stability, n is 3,
When n is 2, R ³ is preferably an aryl group. As the polysilanol, silanol R ⁴ ₂ Si
(OH) ₂ or R ⁴ Si(OH) ₃ (in the formula, R ⁴ represents a hydrocarbon group) is a condensed compound having a siloxane bond, and its structure can be linear, cyclic, or three-dimensional. It may have any structure such as a network structure, but as for the hydroxyl group content, those having at least one hydroxyl group per molecule are used. It is preferable that the hydroxyl group content in the polysilanol is 4 to 14 mmol/g. Such polysilanols can be easily obtained, for example, by hydrolyzing the corresponding organic halosilane under appropriate conditions. for example,
One or two organic trihalosilanes and/or organic dihalosilanes represented by the general formula R ⁴ SiX ₃ or R ⁴ ₂ SiX ₂ (wherein R ⁴ represents a hydrocarbon group and X represents a halogen atom) or more in an inert hydrocarbon solvent such as heptane, cyclohexane, benzene, toluene, etc., preferably from -50°C to 100°C
At a temperature around 20°C, the halogen in the organohalosilane is reacted with water or an aqueous alkali solution in an amount equivalent to or more, and then the resulting solution is washed with water until it becomes neutral.
By drying, a polysilanol solution can be obtained. At this time, the degree of polymerization of polysilanol can be controlled by the hydrolysis temperature and alkali concentration. The polysilanol may be isolated and used by distilling off the solvent from this solution, or the solution may be used as it is. Polysilanols are made by combining one or more silanols represented by the general formula R ⁴ ₂ Si(OH) ₂ (in the formula, R ⁴ represents a hydrocarbon group), preferably in an alcohol in the presence of an alkali. The desired polysilanol can be easily obtained by heating to 50°C or higher. R ⁴ in the general formula of polysilanol, organic trihalosilane, organic dihalosilane, and silanol
Examples include alkyl, cycloalkyl, cycloalkenyl, aryl, aralkyl, alkaryl and cycloaralkyl groups having up to 20 carbon atoms. In particular, methyl, ethyl, propyl, butyl, amyl, hexyl, heptyl, octyl,
Preferred are alkyl groups such as decyl, aryl groups such as phenyl, and aralkyl groups such as benzyl. The reaction between a Grignard compound and at least one compound selected from water, alcohol, phenols, silanol, and polysilanol,
Both components are brought into contact at -50~100℃, then 20~200℃
C., preferably 20 to 150.degree. C., particularly preferably 20 to 80.degree. C. for several hours. In the case of water, alcohol or phenols, the proportions of both components used are as follows:
The ratio (molar ratio) of Mg-C bonds is 0.01 to 2, preferably 0.5 to 1.5, and in the case of silanol or polysilanol, the ratio of hydroxyl group in silanol or polysilanol to Grignard compound
The ratio (molar ratio) of Mg-C bonds is 0.1 to 10, preferably 1 to 2. The catalytic reaction is preferably carried out in a solvent; for example, water is dissolved in an ether solvent such as diethyl ether, dibutyl ether, or tetrahydrofuran, and alcohols, phenols, silanols, and polysilanols are dissolved in an aromatic solvent such as benzene or toluene. Hydrocarbons, saturated aliphatic hydrocarbons such as n-heptane and n-hexane, alicyclic hydrocarbons such as cyclohexane and methylcyclohexane, and ethers such as diethyl ether and dibutyl ether are dissolved and reacted. The reaction mixture obtained after the catalytic reaction may be used as it is, or may be used after separating solids from the reaction mixture by filtration or decantation, or removing unreacted substances or solvent by vaporization. On the other hand, magnesium halides include magnesium dichloride, magnesium dibromide, and magnesium diiodide, and among these, anhydrous magnesium dichloride is particularly preferred. Note that as the magnesium halide, an active form obtained by ball milling is preferable. Ball milling may be carried out in advance prior to the preparation of the catalyst component, or may be carried out simultaneously with the preparation of the catalyst component. On the other hand, titanium tetrahalides include titanium tetrachloride, titanium tetrabromide, titanium tetraiodide, and the like, with titanium tetrachloride being particularly preferred. As the electron-donating compound, a nitrogen-containing compound selected from amines and carboxylic acid amides, phosphine, phosphine oxide, phosphoric acid ester,
Phosphorus-containing compounds selected from phosphites and phosphoamides, and oxygen-containing compounds selected from ketones and carboxylic esters can be used. In addition, in the carboxylic acid ester mentioned here, the hydrocarbon group of the carboxylic acid residue may have a substituent such as an amino group or an alkoxy group.
Such examples include amino acid esters. Specific examples of electron-donating compounds include nitrogen-containing compounds such as tetramethylethylenediamine, tetraethylethylenediamine, acetamide, triethyl phosphate, tributyl phosphate, triphenylphosphine, triphenylphosphite, triethylphosphine oxide, and triphenyl. Phosphorus-containing compounds such as phosphine oxide, tris(nonylphenyl)phosphite, hexamethylphosphoric triamide, methyl benzoate, ethyl benzoate, propyl benzoate, butyl benzoate, phenyl benzoate, p-toluic acid methyl ester, p- toluic acid ethyl ester,
p-Toluic acid propyl ester, p-toluic acid butyl ester, p-toluic acid hexyl ester, p-toluic acid octyl ester, p-ethylbenzoic acid methyl ester, p-ethylbenzoic acid ethyl ester, p-ethylbenzoic acid propyl ester ester, p-ethylbenzoic acid butyl ester,
p-ethylbenzoic acid hexyl ester, p-ethylbenzoic acid octyl ester, p-butylbenzoic acid methyl ester, p-butylbenzoic acid ethyl ester, p-butylbenzoic acid propyl ester,
p-Butylbenzoic acid butyl ester, p-butylbenzoic acid hexyl ester, p-butylbenzoic acid octyl ester, p-hexylbenzoic acid methyl ester, p-hexylbenzoic acid methyl ester, p-hexylbenzoic acid ethyl ester, p-
Hexylbenzoic acid propyl ester, p-hexylbenzoic acid butyl ester, p-hexylbenzoic acid hexyl ester, p-hexylbenzoic acid octyl ester, p-octylbenzoic acid methyl ester, p-octylbenzoic acid ethyl ester, p
-Octylbenzoic acid propyl ester, p-octylbenzoic acid butyl ester, p-octylbenzoic acid hexyl ester, p-octylbenzoic acid octyl ester, p-methoxybenzoic acid methyl ester,
Ethyl p-methoxybenzoate, propyl p-methoxybenzoate, butyl m-methoxybenzoate, o
- phenyl methoxybenzoate, methyl p-ethoxybenzoate, ethyl p-ethoxybenzoate, phenyl acetate, phenyl propionate, ethyl crotonate, propyl crotonate, butyl crotonate,
Ethyl cinnamate, propyl cinnamate, butyl cinnamate, dimethylglycine ethyl ester, dimethylglycine propyl ester, dimethylglycine butyl ester, diphenylglycine ethyl ester, diphenylglycine butyl ester, p-
Examples include oxygen-containing compounds such as dimethylaminobenzoic acid ethyl ester, benzophenone, and acetophenone. Particularly preferred are carboxylic acid esters. In the method of the present invention, the following methods (a), (b), and (c) may be used to contact the solid magnesium compound, titanium tetrahalide, and electron donating compound.
can be mentioned. (a) A method in which an electron-donating compound is added to a solid magnesium compound and the compound is contacted with the compound, and then with titanium tetrahalide. (b) A method of contact-treating a solid magnesium compound with titanium tetrahalide and simultaneously contact-treating it with an electron-donating compound. (c) A method of synthesizing a solid magnesium compound in the presence of an electron-donating compound and then contacting it with titanium tetrahalide. In these methods, the temperature of the contact treatment of titanium tetrahalide is 20 to 350°C, preferably 60 to 200°C.
The temperature of the contact treatment with the electron-donating compound is selected from the range of 50 to 200°C. The contact treatment with titanium tetrahalogen and the electron-donating compound may be carried out without a solvent or in a solution state diluted with an appropriate solvent. Examples of solvents include aromatic hydrocarbons such as benzene and toluene, saturated aliphatic hydrocarbons such as n-pentane, n-hexane, n-heptane, n-octane, n-decane, and liquid paraffin, and cyclohexane and methylcyclohexane. Examples include alicyclic hydrocarbons and ethers such as diethyl ether and dibutyl ether. The usage ratio of titanium tetrahalide and solid magnesium compound is 0.1 to 50 (molar ratio), preferably 1 to 30 (molar ratio) of titanium tetrahalide/magnesium atoms, and the usage ratio of electron donating compound and solid magnesium compound is The electron-donating compound/magnesium atom ratio is 0.01 to 10, preferably 0.05 to 2.0 (molar ratio). A titanium-containing solid catalyst component having a titanium content of 0.1 to 20% by weight, preferably 0.1 to 10% by weight can thus be obtained, which is washed with an inert hydrocarbon solvent and subjected to the polymerization of the olefin. Examples of inert hydrocarbon solvents include aromatic hydrocarbons such as benzene and toluene, n-pentane, n-hexane, n-
Saturated aliphatic hydrocarbons such as heptane, n-octane, n-dodecane, and liquid paraffin, and alicyclic hydrocarbons such as cyclohexane and methylcyclohexane are used. Next, as an organoaluminum compound as a promoter, for example, the general formula AlR ⁵ mX ₃ -m (in the formula,
R ⁵ represents a hydrocarbon group having 1 to 8 carbon atoms, m is a number of 1 to 3, and X represents a halogen atom. ) is used. Particularly preferred are trialkylaluminums such as triethylaluminum, tripropylaluminum, triisobutylaluminum, trihexylaluminum, and trioctylaluminum. The amount of the organoaluminum compound to be used is selected from the range of 1 to 500 mol, preferably 1 to 100 mol, particularly preferably 2 to 50 mol, per 1 mol of Ti. Therefore, in the process of the present invention, in the first step, using the catalyst system as described above, the production of olefin polymer per gram of titanium in the catalyst is achieved by using no hydrogen at all or using hydrogen in the amount described below. Polymerize α-olefin under conditions such that the amount is 50,000 grams or more, preferably 100,000 grams or more, and the extraction residue with boiling normal heptane is 90% or more, preferably 93% or more, and the viscosity average molecular weight is 50. Produces more than 10,000 olefin polymers. If the olefin polymer obtained at this stage has a viscosity average molecular weight of less than 500,000, the proportion of low molecular weight polymer increases, and as a result, the proportion of extraction residue with boiling normal heptane decreases. If the proportion of the residue extracted by boiling normal heptane in the produced olefin polymer decreases to less than 90%, this is unfavorable in terms of product properties. Although the physical properties are improved by removing the components extracted by boiling normal heptane, the proportion of olefin polymer that is lost in the process increases, and the purpose of improving the olefin unit consumption cannot be achieved. Of course, if the catalyst efficiency is low, for example, if the amount of olefin polymer produced is less than 50,000 grams per gram of titanium in the catalyst, the proportion of extraction residue with boiling n-heptane will be high, but the catalyst residue in the produced olefin polymer will be This is unfavorable in terms of product properties.
On the other hand, if a large amount of catalyst residue is to be removed, the process becomes expensive. The polymerization or copolymerization reaction can be carried out by various polymerization methods such as solution polymerization in the presence of an inert hydrocarbon or liquefied α-olefin solvent, slurry polymerization, and gas phase polymerization without a solvent. Furthermore, if necessary, a known third component, such as the above-mentioned electron-donating compound, particularly a carboxylic acid ester, may be added during the polymerization. The temperature during polymerization is 20 to 100°C, preferably 50°C.
The temperature is selected from the range of ~80°C, and the pressure is selected from the range of 1 to 100 atmospheres. Hydrogen can also be present in the polymerization zone, but the amount must be less than the amount that produces an olefin polymer with a viscosity average molecular weight of 500,000. Specifically, it depends on the polymerization conditions such as the type of α-olefin to be polymerized, the type of catalyst, cocatalyst, third component, etc., polymerization temperature, catalyst efficiency, and the usage ratio of each catalyst component, but it cannot be generalized. , using propylene in a solvent such as hexane or heptane at a temperature of 60 to 70°C and a pressure of 5 to 25 kg/cm ² in the coexistence of triethylaluminum and a carboxylic acid ester, to obtain the amount of olefin polymer per gram of titanium unit in the catalyst. When polymerizing with a production amount of 100,000 grams or more, the amount of hydrogen relative to propylene is 5 mol% or less. The α-olefin to be polymerized has the general formula
It is α-olefin represented by R ⁶ -CH=CH ₂ (wherein R ⁶ is an alkyl group having 1 to 8 carbon atoms), or a mixture of this and ethylene. Specifically, propylene, butene-1, pentene-1, hexene-1
1,4 methylpentene, -1,3 methylbutene-
1, a mixture thereof, or a mixture of these and ethylene. In particular, propylene homopolymers or 90% by weight or more of propylene
It is suitable for producing copolymers containing up to 10% by weight of ethylene or other α-olefins. When copolymerizing, random copolymerization or block copolymerization may be used. The viscosity average molecular weight (hereinafter sometimes indicated by the symbol v) in the present invention is 135
From the intrinsic viscosity [η] measured in °C tetralin,
Indicates the value calculated from the formula [η] = 0.80 × 10 ^{4 v 0} . The ratio of the dried extraction residue after extraction with normal heptane for 6 hours to the total olefin polymer is indicated. Next, in the method of the present invention, as a second step,
The olefin polymer obtained as described above is degraded to lower the viscosity average molecular weight and improve processability. The degree of degradation is 0.1 to 100 g/10 when expressed as a melt flow index (hereinafter abbreviated as "MFI", a value measured according to ASTMD1238).
minutes, preferably from 0.5 to 60 grams/10 minutes, more preferably from 1 to 50 grams/10 minutes. In terms of viscosity average molecular weight, an olefin polymer with particularly good processability can be obtained by reducing the molecular weight to less than 400,000. The method of degradation is not particularly limited, and any method may be used as long as it can reduce the viscosity average molecular weight of the olefin polymer to the above range. Specifically, the following methods (a) to (d) may be mentioned. (a) 500 s ^-1 above the melting point of the olefin polymer
A method of heating and kneading with a twin-screw kneader, such as a Banbury mixer, which applies shear stress. (b) Olefin polymer under inert atmosphere at 200~
A method of thermal decomposition by heating to 350℃ for several seconds or more. (c) A method of adding radiation having an energy of 1 megarad or more. (d) Olefin polymer in the presence of accelerator
Method of heating to 300℃ for several seconds or more. Accelerators in the method (d) include oxygen or oxygen-generating substances; peroxides, azo compounds and other radical generators; phosphite esters, phosphates or thiophosphates; at least one hydrogen atom is a hydroxyl group; organic amines having hydrocarbon groups that are substituted or contain tertiary carbon atoms;

[Formula] Organotin compound having Sn-O-Sn or Sn-O-R ⁶ bond (in the formula, R ⁶ represents a hydrocarbon); containing at least one tertiary carbon atom and further optionally Hydrocarbons or halogenated hydrocarbons which may even contain a hydroxyl group; mercaptobenzothiazole or its salt; sulfenamides; benzothiazyl; thiuram di(or mono)sulfide number; dithiocarbamate salts; alkylxanthates; oximes; Nitroso compounds; benzamidophenyl disulfides and the like. These accelerators may be added in an amount of about 1 ppm (based on weight) to 1% by weight based on the olefin polymer. Addition methods include methods such as kneading the additive as it is or as a masterbatch into the olefin polymer, and adding the suspension or dissolution in a non-solvent or solvent to the olefin polymer. As detailed above, the method of the present invention can obtain an olefin polymer with high catalytic efficiency and excellent processability, that is, high fluidity when melted, and a large proportion of extraction residue with boiling normal heptane. The process benefits are significant. The method of the present invention will be explained in more detail below with reference to Examples and Comparative Examples. Examples 1 to 3 (1) Preparation of catalyst components 3.2 g of pure water and 170 ml of toluene were placed in a 500 ml four-necked flask, and the reaction vessel was kept cool at -20° C. with magnetic stirring. Add 25 g (0.118 mol) of phenyltrichlorosilane to 70 ml of this toluene suspension.
A toluene solution was added dropwise using a dropping funnel over a period of 1 hour. After the dropwise addition was completed, the reaction mixture was heated to 0° C., and stirring was continued for an additional 30 minutes. Next, it was washed with ice water until the washing solution became neutral. The obtained toluene solution was dehydrated and dried over anhydrous sodium sulfate, filtered, and the resulting solution was used as a raw material for preparing a carrier. The hydroxyl group concentration of this toluene solution was determined by the method described below and was 8.1 m
It was mol/g. The amount of hydroxyl groups in the polysilanol was determined as follows. Add an appropriate amount of Grignard compound so that it is in excess of the hydroxyl group, and heat at 100℃ for 1 hour.
The reaction was completed by heating and stirring for an hour. Next, benzyl bromide was added in an amount equal to the number of moles of the Grignard compound used, and the mixture was heated and stirred at 100° C. for 1 hour. Next, after returning the reaction vessel to room temperature, pure water was added for hydrolysis, and the resulting alkaline component was titrated with hydrochloric acid or sulfuric acid in the presence of an appropriate indicator. In this case, use phenolphthalene alcohol solution as the indicator and as the acid.
A 0.1N hydrochloric acid aqueous solution was used. In a 300 ml four-necked flask purged with dry nitrogen, add a toluene solution of 0.34 mol/hydroxyl group of the polyphenylsilanol synthesized above.
Pour 17 ml and add 3.9 mol/n of chloride to this.
1.5 ml of a di-n-butyl ether solution of butylmagnesium was slowly added dropwise at 25° C. with sufficient stirring. After the dropwise addition was completed, the mixture was stirred and aged at 110°C for 1 hour. After cooling to 25°C, 1.2 ml of a toluene solution of ethyl benzoate at a concentration of 0.5 mol/(ethyl benzoate/Mg atom = 0.1 molar ratio) was added dropwise with stirring.
After the dropwise addition was completed, the mixture was heated to 100°C and stirring was continued for 2 hours. Next, toluene and di-n-butyl ether were distilled off under reduced pressure and dried to obtain a white powder.
120 mmol of titanium tetrachloride was added to the obtained white powder, and the temperature was raised to 130°C while stirring. During the temperature rise, it became a blackish brown viscous semi-dissolved state. at 130℃
After heating and stirring for 30 minutes, 150 ml of n-heptane was added to the semi-dissolved liquid, and a precipitate was formed. The supernatant was separated, and the precipitate was washed five times with 150 ml of n-heptane to obtain a grayish brown solid. The titanium content of the obtained solid was 2.5% by weight. Similarly, the Cl content was 37.8% by weight. (2) Polymerization To 21.2 mg of the catalyst component prepared in (1) above, add 0.8 mmol of triethylaluminum, 0.12 mmol of p-methylmethylbenzoate, and n-hexane.
0.4 was charged into a 2 autoclave purged with nitrogen gas and propylene monomer. Polymerization was carried out at 60° C. for 2 hours at a constant propylene pressure of 17 Kg/cm ² (gauge). After purging unreacted monomers, 441 g of dry polymer powder was obtained. v was 86.4×10 ⁵ and 92.3%. (3) Degradation Take a part of the polypropylene powder obtained in (2),
v,, MFI of the olefin polymer obtained by heating in air at 140°C for the time shown in Table 1.
When measured, the results shown in Table 1 were obtained.

[Table] Comparative Example 1 Polymerization was carried out under the same conditions as in Example 1 (2) except that the gas phase hydrogen concentration was changed to 2.5 mol %, and 413 g of dry polymer powder was obtained. v is 2.6×10 ⁵ and MFI is 7.5g/10 minutes.
It was 81.5%. Examples 4-5 100 each of polypropylene powder obtained in (2) of Example 1
Table 2 shows the results of measuring the v, MFI of the resulting olefin polymer, which was mixed with the following additives based on parts by weight and kneaded at 200° C. for 90 seconds in the atmosphere shown in Table 2. Tetrakis[methylene-(3,5-di-t-butyl-4-hydroxyhydrocinnamate)]methane 0.07 parts by weight Dilaurylthiodipropionate 0.2 2,6-t-butyl-p-cresol
0.08 〃 Calcium stearate 0.15 〃 α,α′-bis-t-butyl-peroxy-p-bis-isopropylbenzene
0.07〃

【table】

Claims (1)

[Scope of Claims] 1. α-olefin is polymerized using a component obtained by contact treatment of a solid magnesium compound, titanium tetrahalide, and an electron-donating compound and an organoaluminum compound as a catalyst, and extraction with boiling normal heptane is performed. Obtaining an olefin polymer with a residue ratio of 90% or more and a viscosity average molecular weight of 500,000 or more,
A method for producing an olefin polymer, which comprises then degrading the obtained olefin polymer until the viscosity average molecular weight becomes less than 400,000. 2. The method according to claim 1, wherein the α-olefin is polymerized without using hydrogen.