JPS6223768B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a propylene-ethylene block copolymer which has good flexibility, excellent processability, high tensile strength, low permanent deformation, and excellent cold resistance. Conventionally, thermoplastic elastomers, which are block copolymers of alkenyl aromatic compounds and conjugated dienes, have been known as the above-mentioned polymers.
The disadvantage of such polymers is that they have poor weather resistance and heat resistance. Compositions comprising ethylene-propylene-nonconjugated diene-terpolymer rubber or ethylene-propylene copolymer rubber and polyolefin resin are also known, but their rubber elasticity is not sufficient. The present inventors have conducted intensive studies on a well-balanced polymer that has low hardness, flexibility, high tensile strength, and low permanent strain compared to conventionally known polymers or compositions, and have developed the present invention. reached. The present invention first produces (A) isotactic polypropylene segments (hereinafter sometimes abbreviated as (A) segments) using a catalyst that provides isotactic polypropylene, and then (B) propylene-ethylene random copolymer. The combined segment (hereinafter sometimes abbreviated as (B) segment) is
In a method for producing a propylene-ethylene block copolymer by polymerizing and producing on the same catalyst,
The (A) segment is produced in an amount of 20 to 50% by weight based on the total polymer, and then the (B) segment is produced at 710% by weight.
It has two distinct absorption bands in the infrared absorption spectral wavenumber range from to 750 cm ^-1 and has an ethylene content of 30
This is a method for producing a propylene-ethylene block copolymer, characterized in that it produces a propylene-ethylene random copolymer of 50 to 80% by weight based on the total polymer amount. As the catalyst for providing the isotactic polypropylene segment (A) of the present invention, a system containing a titanium-containing composition and an organoaluminum compound is used. The titanium-containing composition used in the present invention is titanium trichloride obtained by reducing titanium tetrachloride with metallic aluminum or an organoaluminum compound, titanium trichloride activated by crushing or heat-treating titanium trichloride, or A pulverized product of titanium chloride and an electron-donating compound, a product obtained by precipitating liquefied titanium trichloride in the presence of an ether compound, a product obtained by reducing titanium tetrachloride with diethylaluminium chloride, followed by diisoamyl ether, and a product obtained by precipitating titanium trichloride in the presence of an ether compound. Reacted with titanium chloride,
Examples include those obtained by contacting titanium tetrachloride, a magnesium compound, and an electron-donating compound. In addition, the _{organoaluminum} compound used in the present invention has the general formula AlR _n (1≦m≦3).Specifically, triethylaluminum, tri-n-propylaluminum, tri-isopropylaluminum, tri-iso-butylaluminum, diethylaluminum chloride, di-iso-butyl Examples include aluminum chloride and diethylaluminium iodide.Also, mixtures of those selected from these can be used.As the third component of the polymerization catalyst system, various electron-donating compounds are added during polymerization to improve the performance of the catalyst ( Such electron-donating compounds include (a) ethers, such as diethyl ether, di-n-butyl ether, diisoamyl ether, tetrahydrofuran, dioxane, diethylene glycol dimethyl ether, and diphenyl ether; (b) Carboxylic acid esters such as methyl formate, ethyl acetate, ethyl benzoate, ethyl toluisoate, methyl methacrylate, etc. (c) Ketones such as methyl ethyl ketone, acetophenone, (d) Aldehydes such as acetaldehyde , isobutyraldehyde,
benzaldehyde, (ho)amines, nitriles, acid amides such as diethylamine, aniline,
Acetonitrile, acrylamide, tetramethylurea, etc.; (he)phosphoric acid compounds, such as triphenylphosphine, triphenylphosphite, triphenyl phosphate, etc.; (tri)sulfur compounds, such as carbon disulfide, methylphenyl sulfone, etc.; can be given. Isotactic polypropylene segment is 20% by weight based on the total polymer amount (hereinafter, the weight percentage of each segment is based on the total polymer amount)
If it is less than 50% by weight, the heat resistance will be poor and the tensile strength will be greatly reduced, and if it exceeds 50% by weight, the hardness will be excessively high and the permanent strain will be large, so it is not preferable as an elastomer. A particularly preferable content range of the segment (A) is 25 to 40% by weight. (A) The monomer component for the segment is propylene 100.
% isotactic polypropylene is preferred, but isotactic polypropylene containing 5% by weight or less of ethylene may also be used; if the ethylene content exceeds 5% by weight, the mechanical properties will deteriorate, so it is not preferred. . (A) Segment has its melt fluorate (MFR) (ASTMD−
According to 1238 (L) (230℃, 2.16Kg). same as below)
is preferably in the range of 0.5 to 200. The propylene-ethylene random copolymer segment has two distinct absorption bands in the infrared absorption spectral wavenumber range from 710 to 750 cm ^-1 . If it does not have this, the heat resistance of the propylene-ethylene block copolymer of the present invention will be poor and the tensile strength at high temperatures will be significantly reduced, which is not preferable. It is necessary to control the ethylene content of the propylene-ethylene random copolymer segment to 30 to 85% by weight, and the production amount to 50 to 80% by weight based on the total polymer amount. If the ethylene content is outside the above range, the resulting polymer will have poor flexibility and cold resistance, and will have a large permanent set, which is not preferred. (B) The amount of segment produced is 50 based on the total amount of polymer.
If it is less than 80% by weight, the rubber elasticity of the obtained polymer will be low and permanent elongation will increase, and if it exceeds 80% by weight, mechanical strength will be decreased and heat resistance will be impaired, which is not preferable. The molecular weight of the (B) segment can also be controlled by adding hydrogen during polymerization. Furthermore, it is a preferable embodiment to obtain a molecular weight of the (B) segment as high as possible because it is expected that the mechanical properties of the final copolymer will be improved. (B) The final polymer obtained by segment generation has an MFR of 0.1
A range of ~100 is appropriate. The propylene-ethylene block copolymer of the present invention can be produced in essentially the same manner as in the production of isotactic polypropylene, except that the polymerization is carried out in stages. Therefore, the catalyst may be any catalyst that can polymerize propylene into isotactic polypropylene. Therefore, in carrying out the production process of the present invention, a combination catalyst of dialkyl aluminum monohalide and titanium trichloride, for example, is used as a catalyst, and a solvent such as a nonpolar solvent such as a hydrocarbon (for example n
-hexane, liquid propylene, etc.) or in the gas phase without a solvent, preferably in the presence of a molecular weight regulator, such as hydrogen, at 0 to 100°C.
At a temperature of 30 to 70 DEG C. and a pressure of less than 30 Kg/cm ² G, first propylene and then the ethylene/propylene mixture may be polymerized. The polymerization initially starts with a propylene polymerization step. It is undesirable to carry out the polymerization step of the ethylene/propylene mixture first, since this significantly increases the viscosity of the polymerization system. The polymerization and production of the (A) segment and (B) segment of the present invention can be carried out in the same reactor or in different reactors, and can be carried out either batchwise or continuously. The propylene-ethylene block copolymer of the present invention may contain zinc oxide, calcium oxide,
Metal oxides such as magnesium oxide, fatty acids such as stearic acid and lauric acid, salts of fatty acids such as lead stearate and lead oleate, channel black, high strength black, low strength black,
Carbon black such as thermal black, calcium carbonate, magnesium carbonate, calcium sulfate, barium sulfate, aluminum silicate, phenol-formaldehyde resin, polyethylene resin, polystyrene resin, ethylene propylene rubber, fillers such as asbestos, plasticizers, naphthalene oil , varaffin oil, castor oil, glycerin, stabilizers, pigments, tackifiers, flame retardants, etc. can be added. The propylene-ethylene block copolymer of the present invention is preferably used for extruded insulated wire, gaskets, weather stripping, flexible bumpers, hoses, liners, mats, shoe soles, toys, kitchen utensils, and the like. EXAMPLES The present invention will be explained in more detail below with reference to Examples and Comparative Examples. The physical properties in the table were measured according to the following criteria. MFR: ASTM D1238 (L) Ethylene content: Infrared absorption spectrum Tensile strength: JISK 6301 Elongation: JISK 6301 Hardness: JISK 6301 Permanent elongation: Strain rate after holding 100% elongation for 10 minutes and leaving it under no tension for 10 minutes Brittleness Temperature: ASTM D-746 Examples 1 to 3, Comparative Examples 1 to 4 After fully replacing the polymerization vessel with a capacity of 30 with Tituso gas,
15 dried n-hexane, 10 g of diethylaluminium chloride, 2 to 10 g of AA type TiCl ₃ (finely pulverized product of a composition of TiCl ₃ 1/3 AlCl ₃ ) determined depending on the polymerization conditions, and for molecular weight adjustment. Hydrogen was added and heated to 60°C. Add propylene and pressure 8
Kg/cm ² G and the temperature was maintained at 60° C. to produce isotactic polypropylene segments in a predetermined proportion. Thereafter, unreacted propylene was purged to 1 kg/cm ² . Thereafter, a propylene/ethylene mixture was fed at a constant rate to generate propylene-ethylene random copolymer segments. The obtained propylene-ethylene block copolymer (hereinafter sometimes referred to as the final polymer) was purified with alcohol to obtain a dry product. Example 4 In Example 3, type A was used instead of type AA TiCl ₃ .
Using a milled composition of the reaction product of TiCl ₄ with the ethyl ether of TiCl ₃ (an unpulverized fine product of the composition TiCl ₃ 1/3 AlCl ₃ ), and the ethylene content of the propylene/ethylene random copolymer segment of
A final polymer was obtained in the same manner as in Example 3 except that the amount was changed to 65 wt%. Comparative example 5 Isotactic polypropylene (MFR10)
40 parts by weight and ethylene-propylene-ethylnorbornene ternary copolymer rubber (ethylene content 70% by weight,
2% by weight of ethylidene norbornene, MFR 0.4, 60 parts by weight of JSREP57C manufactured by Japan Synthetic Rubber Co., Ltd.) were placed in a Banbury mixer and kneaded for 15 minutes at 200 to 220°C. Table 1 shows the weight percent of each segment (A) and (B) of the final polymers obtained in Examples 1 to 4 and Comparative Examples 1 to 4 and the physical property values of the polymers. Comparative Example 5 is also shown. Example 5 1 kg of the block copolymer of the present invention prepared in advance and the pulverized product of AlCl ₃ and Mg(OH) ₂ were placed in an autoclave with a stirrer (capacity 50) that was sufficiently purged with nitrogen gas and mixed with ethyl silicate. Then, 1 g of the solid product obtained by reaction treatment with TiCl ₄ , 20 g of triethylaluminum, and 2 g of ethyl anisate were added in this order, and in the presence of 80 hydrogen, 20 kg/cm ² G of propylene containing a small amount of ethylene was added. Gas phase polymerization was carried out at 70°C for 2 hours with stirring. Thereafter, unreacted propylene was purged, propylene and ethylene were supplied in the presence of hydrogen 20, and a copolymerization reaction was carried out at a pressure of 10 Kg/cm ² G and 60° C. for 2 hours. The heat of polymerization was removed by spraying liquefied propylene. Powder block copolymer 10
Got Kg. The physical properties of the obtained copolymer are shown in Table 1. Example 6 Into an autoclave with a stirrer (capacity: 50) that was sufficiently purged with nitrogen gas, 1 kg of the previously produced block copolymer of the present invention and TiCl ₄ were reduced with diethylaluminum chloride, followed by diisoamyl ether. 1.25 g of solid product obtained by reaction treatment with TiCl ₄ , 10 g of diethylaluminum chloride
in this order, pressure 20Kg/cm ² G, 70℃ 1.5
After polymerization of propylene was carried out for an hour and unreacted propylene was purged, propylene and ethylene were supplied, and a copolymerization reaction was carried out at a pressure of 10 kg/cm ² G and 60° C. for 4 hours. The heat of polymerization was removed by spraying with liquefied propylene, and the molecular weight of the polymer was adjusted by feeding hydrogen. 10 kg of powder block copolymer was obtained. The physical properties of the obtained copolymer are shown in Table 1. 【table】

Claims (1)

[Claims] 1. First, (A) isotactic polypropylene segment (hereinafter abbreviated as (A) segment) is produced using a catalyst that provides isotactic polypropylene.
, followed by (B) propylene-ethylene random copolymer segment (hereinafter abbreviated as (B) segment),
In a method for producing a propylene-ethylene block copolymer by polymerizing and producing on the same catalyst,
The (A) segment is produced in an amount of 20 to 50% by weight based on the total amount of polymer, and then the (B) segment is
It has two distinct absorption bands in the infrared absorption spectral wavenumber range from 710 to 750 cm ^-1 , and the ethylene content
A method for producing a propylene-ethylene block copolymer, characterized in that 30-85% by weight of a propylene-ethylene random copolymer is produced in an amount of 50-80% by weight based on the total amount of the polymer.