CN109517099B

CN109517099B - External electron donor, olefin polymerization catalyst system and application thereof

Info

Publication number: CN109517099B
Application number: CN201811424430.0A
Authority: CN
Inventors: 马殿伟; 李慧君; 张震
Original assignee: Shandong Lujing Chemical Technology Co ltd
Current assignee: Shandong Lujing Chemical Technology Co ltd
Priority date: 2018-11-27
Filing date: 2018-11-27
Publication date: 2021-07-30
Anticipated expiration: 2038-11-27
Also published as: CN109517099A

Abstract

The invention provides an external electron donor, an olefin polymerization catalyst system and application thereof, wherein the external electron donor composition comprises 1-98 mol% of halogenated hydrocarbon, 1-98 mol% of aliphatic carboxylic ester and 1-98 mol% of alkoxy silane; the olefin polymerization catalyst system prepared by the invention can improve the polymerization activity of polypropylene at the conventional polymerization temperature, inhibit high-temperature reaction activity, improve the hydrogen regulation sensitivity of the catalyst, reduce the addition of hydrogen in the reaction process and ensure the stability of the polymerization process, thereby ensuring the safe operation of industrial production.

Description

External electron donor, olefin polymerization catalyst system and application thereof

Technical Field

The invention relates to the field of polyolefin catalysis, in particular to an external electron donor composition, an olefin polymerization catalyst system and application thereof.

Background

Polyolefin is an indispensable material in modern society because of its excellent properties and low price. One core of polyolefin research is the research of novel, high performance catalysts. In recent years, the continuous updating of Ziegler-Natta catalytic systems has led to a great growth in the polyolefin industry. However, the main innovation space of the Zegler-Natta catalyst system focuses on the aspects of the catalyst carrier and the internal electron donor, and researchers change the two components to enable the catalyst system to be replaced for many generations so as to achieve the purposes of improving the polymerization activity and the product performance.

In the polymerization process, except for a catalyst and a cocatalyst of alkyl aluminum, a silane external electron donor is added into a reaction system to mainly improve the isotacticity of the product and ensure the physical properties of the product, but the activity of the reaction is inevitably influenced. Therefore, in order to obtain a product with ideal isotacticity, a proper amount of silane compound is usually added as an external electron donor in industrial production, and the balance between polymerization activity and polypropylene isotacticity is obtained.

The gas-phase fluidized bed reactor is widely applied in the industry at present, and the produced polypropylene product has excellent performance and wide coverage because the process is simple and controllable, so that the product becomes the mainstream of the existing polypropylene newly-built device, but the problem of caking in a high-temperature kettle in the gas-phase fluidized bed process is one of the factors limiting the production of products in a wider range.

CN104610475A discloses a catalyst for olefin polymerization, wherein an alkylene trihydrocarbyloxysilane compound is added as an external electron donor compound during olefin polymerization in a granular solid catalyst component using a carboxylate compound as an internal electron donor, so that the catalyst not only can maintain high activity and high orientation capability, but also the hydrogen regulation sensitivity of the catalyst is greatly improved, but no mention is made about the activity capable of inhibiting high temperature reaction.

CN105524192A discloses a polypropylene catalyst composition with high-temperature activity inhibition effect, which comprises a main catalyst, a cocatalyst and an external electron donor component, wherein the main catalyst comprises a titanium-containing compound, the cocatalyst is aluminum alkyl, the external electron donor component comprises a first external electron donor and a second external electron donor, the first external electron donor comprises sec-octyl cyclohexanoate, and the second external electron donor is an alkoxysilane compound; it also provides an olefin polymerization process using the catalyst composition and the use of the catalyst composition; the polypropylene catalyst composition prepared by the method can effectively control the activity of reaction at high temperature, avoids the risk of high-temperature agglomeration in a reactor, but inevitably limits the activity of the catalyst at the conventional polymerization temperature (65-75 ℃).

CN108129591A discloses an external electron donor composition, an olefin polymerization catalyst system and application of the external electron donor composition and the olefin polymerization catalyst system, belonging to the technical field of polyolefin production. The provided external electron donor composition for olefin polymerization consists of alkoxy silane and halogenated hydrocarbon; wherein the content of the alkoxy silane is 0.1-99.9 mol%, the content of the halogenated hydrocarbon is 0.1-99.9 mol%, and the total content of the two components is 100 mol%. The olefin polymerization catalytic system prepared by the invention can greatly improve the polymerization activity, but the activity of inhibiting high-temperature reaction is not mentioned.

Therefore, it is necessary to develop an olefin polymerization catalyst system which can increase the polymerization activity of polypropylene at a conventional polymerization temperature (65-75 ℃) and can suppress the high-temperature reaction activity.

Disclosure of Invention

The invention aims to provide an external electron donor, an olefin polymerization catalyst system and application thereof, wherein the olefin polymerization catalyst system can improve the polymerization activity of polypropylene at the conventional polymerization temperature, inhibit the high-temperature reaction activity, improve the hydrogen regulation sensitivity of the catalyst and reduce the addition of hydrogen in the reaction process.

In order to achieve the purpose, the invention adopts the following technical scheme:

one of the purposes of the invention is to provide an external electron donor, which comprises 1-98 mol% of halogenated hydrocarbon, 1-98 mol% of aliphatic carboxylic ester and 1-98 mol% of alkoxy silane.

According to the invention, halogenated hydrocarbon, aliphatic carboxylic ester and alkoxy silane are innovatively combined to form a composite external electron composition, and on the premise of ensuring low gray level of olefin polymerization, the external electron composition can greatly improve the polymerization activity of propylene at a conventional polymerization temperature on one hand and inhibit high-temperature reaction activity on the other hand, wherein the high temperature is higher than 80 ℃; meanwhile, the hydrogen regulation sensitivity of the catalyst can be improved, the adding amount of hydrogen in the reaction process is reduced, and the stability of the polymerization process is ensured, so that the safe operation of industrial production is ensured.

In the present invention, the molar percentage of the halogenated hydrocarbon is 1 to 98 mol%, for example, 1 mol%, 10 mol%, 20 mol%, 30 mol%, 40 mol%, 50 mol%, 60 mol%, 70 mol%, 80 mol%, 90 mol%, 98 mol%, and the like.

In the present invention, the molar percentage of the aliphatic carboxylic acid ester is 1 to 98 mol%, for example, 1 mol%, 10 mol%, 20 mol%, 30 mol%, 40 mol%, 50 mol%, 60 mol%, 70 mol%, 80 mol%, 90 mol%, 98 mol%, and the like.

In the present invention, the molar percentage of the alkoxysilane is 1 to 98 mol%, for example, 1 mol%, 10 mol%, 20 mol%, 30 mol%, 40 mol%, 50 mol%, 60 mol%, 70 mol%, 80 mol%, 90 mol%, 98 mol%, or the like.

As a preferable scheme of the invention, the external electron donor comprises 30-40 mol% of halogenated hydrocarbon, 20-30 mol% of aliphatic carboxylic ester and 30-50 mol% of alkoxy silane.

In the present invention, as the mole percent content of chlorinated hydrocarbons in the formulation increases, the polymerization activity at conventional polymerization temperatures and the high temperature reactivity also increase; with the increase of the mole percentage content of the aliphatic carboxylic ester in the formula, the polymerization activity at the conventional polymerization temperature is slightly reduced, and the high-temperature reaction activity is sharply reduced; in practical application, a proper range needs to be selected so that the polymerization activity at the conventional polymerization temperature is high, and the polymerization activity at a high temperature is low; as a preferred technical scheme of the application, in the range, the prepared external electron body applied to an olefin polymerization catalytic system can not only ensure better polymerization activity at the conventional polymerization temperature, but also reduce high-temperature reaction activity.

The aliphatic carboxylic ester, the halogenated hydrocarbon and the alkoxy silane are matched for use, so that the high-temperature reaction activity can be reduced, the risk of high-temperature agglomeration in a reactor is avoided, and the reaction activity of the conventional polymerization temperature is not influenced.

In the present invention, the halogenated hydrocarbon includes halogenated alkane or halogenated aromatic hydrocarbon.

In the invention, the halogenated alkane comprises any one or at least two of halogenated matters of C3-C30 chain alkanes or halogenated matters of C3-C30 naphthenic hydrocarbons.

In the present invention, the halogenated aromatic hydrocarbon includes a halide of a C6-C30 aromatic hydrocarbon.

In the present invention, the halogen element is any one of fluorine, chlorine, bromine or iodine or a combination of at least two thereof.

In the present invention, the halogenated hydrocarbon includes chloropropane, chlorobutane, chloropentane, chlorohexane, chloroheptane, chlorooctane, chlorononane, chlorodecane, chlorocyclopropane, chlorocyclobutane, chlorocyclopentane, chlorocyclohexane, chlorocycloheptane, chlorocyclooctane, chlorocyclononane, chlorocyclodecane, chlorobenzene, chloromethylbenzene, o-dichlorobenzene, chloronaphthalene, bromopropane, bromobutane, bromopentane, bromohexane, bromoheptane, bromooctane, bromononane, bromodecane, bromocyclobutane, bromocyclopentane, bromocyclohexane, bromocycloheptane, bromocyclooctane, bromocyclononane, bromocyclodecane, bromobenzene, bromomethylbenzene, o-dibromobenzene, bromonaphthalene, iodobutane, iodopentane, iodohexane, iodoheptane, iodooctane, iodononane, iododecane, iodocyclobutane, bromocyclododecane, bromomethylbenzene, o-dibromobenzene, bromonaphthalene, iodobutane, iodopentane, iodoheptane, iodooctane, iodononane, iododecane, iodocyclobutane, Iodocyclopentane, iodocyclohexane, iodocycloheptane, iodocyclooctane, iodocyclononane, iodocyclodecane, iodobenzene, iodomethylbenzene, o-diiodobenzene or iodonaphthalene, preferably any one or a combination of at least two of chloropropane, chlorocyclohexane, chlorobenzene or bromocyclohexane, more preferably a combination of chloropropane and chlorocyclohexane.

In the present invention, the molar ratio of the chloropropane to the chlorocyclohexane is (1-10):1, for example 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7: 1: 8:1, 9:1, 10:1, preferably (3-6):1, and more preferably 5: 1.

The selected chlorinated hydrocarbon is preferably the combination of chloropropane and chlorocyclohexane, the mole ratio of the chlorinated hydrocarbon and the chlorocyclohexane is limited to be 1:1-10:1, and within the preferable combination and the preferable range of the invention, the external electron donor composition obtained by compounding has higher activity of the conventional polymerization reaction, and if the chlorinated hydrocarbon is not within the preferable combination and the preferable range of the invention, the activity of the conventional polymerization reaction can be reduced.

In the invention, the structural general formula of the alkoxy silane is R_xSi(OR')_yWherein R and R 'are the same or different, and R' are independently C1-C15 ring-opened alkyl, C1-C15 cycloalkyl or C1-C15 aryl; x is 1, 2 or 3; y is 1, 2 or 3; x + y is 4.

In the present invention, the alkoxysilane includes triethoxyisopropoxysilane, diethoxyisopropoxy-t-butoxysilane, triisopropoxytertiarybutoxysilane, diisopropoxytertiarybutoxysilane, diethoxycyclohexyloxyt-butoxysilane, diethoxyphenoxyt-butoxysilane, monoethoxydiisopropoxytertiarybutoxysilane, ethoxyisopropoxy-t-butoxycyclohexyloxysilane, tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane, tetrakis (2-ethylhexyloxy) silane, ethyltrimethoxysilane, ethyltriethoxysilane, methyltrimethoxysilane, n-propyltriethoxysilane, n-propyltrimethoxysilane, decyltrimethoxysilane, decyltriethoxysilane, cyclopentyltrimethoxysilane, cyclopentyltriethoxysilane, cyclopentyltrimethoxysilane, triisopropoxysilane, diisopropoxybenzilane, diisopropoxybenzysilane, diisopropoxysilane-t-butoxysilane, diethoxyphenoxysilane, diethoxytrimethoxysilane, and diethoxyphenoxysilane, 2-methylcyclopentyltrimethoxysilane, 2, 3-dimethylcyclopentyltrimethoxysilane, cyclohexyltrimethoxysilane, cyclohexyltriethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, tert-butyltriethoxysilane, n-butyltrimethoxysilane, n-butyltriethoxysilane, isobutyltriethoxysilane, cyclohexyltriethoxysilane, cyclohexyltrimethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, monochlorotrimethoxysilane, monochlorotriethoxysilane, ethyltriisopropoxysilane, vinyltributoxysilane, trimethylphenoxysilane, methyltrriexypropyloxysilane, vinyltriacetoxysilane, dimethyldimethoxysilane, dimethyltrimethoxysilane, dimethyltriethoxysilane, dimethyltrimethoxysilane, dimethyltriethoxysilane, dimethyltrimethoxysilane, and the like, Dimethyldiethoxysilane, dibutyldimethoxysilane, diisopropyldimethoxysilane, diisopropyldiethoxysilane, t-butylmethyldimethoxysilane, t-butylmethyldiethoxysilane, t-pentylmethyldiethoxysilane, dicyclopentyldimethoxysilane, dicyclopentyldiethoxysilane, methylcyclohexyldimethoxysilane, methylcyclopentyldiethoxysilane, methylcyclopentyldimethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, methylphenyldiethoxysilane, methylphenyldimethoxysilane, bis-o-tolyldimethoxysilane, bis-o-tolyldiethoxysilane, bis-m-tolyldimethoxysilane, bis-m-tolyldiethoxysilane, bis-p-tolyldimethoxysilane, bis-p-tolyldiethoxysilane, trimethylmethoxysilane, di-n-tolyldimethoxysilane, di-m-methoxysilane, di-n-ethyldimethoxysilane, di-n-pentyldimethoxysilane, di-pentyldimethoxysilane, t-pentyldimethoxysilane, di-t-pentyldimethoxysilane, di-o-p-tolyldimethoxysilane, di-o-p-tolyldimethoxysilane, di-p-o-tolyldimethoxysilane, di-o-tolyldimethoxysilane, di-p-o-p-tolyldimethoxysilane, di-p-tolyldimethoxysilane, di-o-p-di-tolyldimethoxysilane, di-p-di-tolyldimethoxysilane, di-p-tolyldimethoxysilane, di-tolyldimethoxysilane, di-o-di-tolyldimethoxysilane, di-p-tolyldimethoxysilane, di-tolyldimethoxysilane, di-p-tolyldimethoxysilane, di-tolyldimethoxysilane, any one or a combination of at least two of trimethylethoxysilane, tricyclopentylmethoxysilane, tricyclopentylethoxysilane, dicyclopentylmethylmethoxysilane or cyclopentyldimethylmethoxysilane, preferably any one or a combination of at least two of n-propyltrimethoxysilane, dicyclopentyldimethoxysilane or methylcyclohexyldimethoxysilane, and more preferably n-propyltrimethoxysilane.

In the present invention, the aliphatic carboxylic acid ester includes any one of isopropyl myristate, di-n-butyl sebacate, sec-octyl cyclohexanecarboxylate or glyceryl tri (acetate) or a combination of at least two thereof, preferably a combination of isopropyl myristate and di-n-butyl sebacate.

In the present invention, the molar ratio of isopropyl myristate to di-n-butyl sebacate is (10-30: 1), for example, 10:1, 12:1, 14:1, 15:1, 16:1, 18:1, 20:1, 22:1, 24:1, 25:1, 26:1, 28:1, 30:1, etc., preferably (20-25: 1), more preferably 22: 1.

The aliphatic carboxylic acid ester selected by the invention is preferably the combination of isopropyl myristate and di-n-butyl sebacate, the molar ratio of the isopropyl myristate to the di-n-butyl sebacate is limited to 10:1-30:1, and within the preferable combination and the preferable range of the invention, the external electron donor composition obtained by compounding has better effect of inhibiting the activity of high-temperature polymerization reaction, and if the aliphatic carboxylic acid ester is not within the preferable combination and the preferable range of the invention, the activity of the high-temperature polymerization reaction can be greatly reduced.

To better demonstrate the efficacy of the present invention, the "normalized activity" is calculated by introducing a concentration variation factor, where the normalized activity at temperature T is defined as the activity at temperature T multiplied by a concentration correction factor, where P (67) is the propylene concentration at 67 deg.C, P (T) is the propylene concentration at temperature T, and P (67)/P (T) is the concentration correction factor. The normalized activity equation is:

the concentration correction factor P (67)/P (T) of propylene is: 67 ℃ (correction factor of 1), 90 ℃ (correction factor of 1.67), 100 ℃ (correction factor of 1.93), 110 ℃ (correction factor of 2.16), 120 ℃ (correction factor of 2.57).

The normalized activity ratio AT/A67, calculated by calculating the normalized activity AT AT the temperature T, can be taken as an indication of the variation of the activity with temperature, and it has been found that in the liquid phase polymerization of propylene, when the temperature reaches 100 ℃ and the normalized activity ratio AT/A67 is 0.35 or less, this indicates that the catalytic system has self-extinguishing properties, meaning that the external electron donor has a high temperature activity inhibiting effect.

The second purpose of the present invention is to provide an olefin polymerization catalyst system comprising a titanium catalyst, an alkyl aluminum compound and the external electron donor composition for olefin polymerization described in the first purpose.

The addition of the external electron donor composition into the olefin polymerization catalyst system can improve the isotacticity and hydrogen regulation sensitivity of the polymer.

In the present invention, the molar ratio of silicon in the alkoxysilane to titanium in the titanium catalyst is (10-500: 1), for example, 10:1, 50:1, 100:1, 150:1, 200:1, 250:1, 300:1, 350:1, 400:1, 450:1, 500:1, etc., preferably (100-.

The third object of the present invention is to provide the use of the olefin polymerization catalyst system described in the second object in propylene polymerization.

In the present invention, the polymerization includes homopolymerization or copolymerization.

Compared with the prior art, the invention has the following beneficial effects:

the olefin polymerization catalyst system provided by the invention can improve the conventional temperature polymerization activity of polypropylene on the premise of ensuring low ash content of olefin, and can inhibit high temperature reaction activity, wherein the optimal conventional temperature polymerization activity is 66.0KgPP/gCat.h, the optimal high temperature reaction activity is 5.0KgPP/gCat.h, and the normalized activity is as low as 7.75%; and the hydrogen regulation sensitivity and the isotacticity of the catalyst can be improved, the isotacticity can reach 99.4 percent, the adding amount of hydrogen in the reaction process is reduced, and the stability of the polymerization process is ensured, so that the safe operation of industrial production is ensured.

Detailed Description

The technical solution of the present invention is further explained by the following embodiments. It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitations of the present invention.

Example 1

This embodiment provides an external electron donor, which includes 30 mol% of halogenated hydrocarbon, 20 mol% of aliphatic carboxylic acid ester, and 50 mol% of alkoxysilane; wherein the alkoxy silane is n-propyl trimethoxy silane; the halogenated hydrocarbon is a combination of chloropropane and chlorocyclohexane; the mol ratio of the chloropropane to the chlorocyclohexane is 5: 1; the aliphatic carboxylic acid ester is a combination of isopropyl myristate and di-n-butyl sebacate; the molar ratio of isopropyl myristate to di-n-butyl sebacate was 22: 1.

The embodiment provides an olefin polymerization catalyst system, which comprises a titanium catalyst, an alkyl aluminum compound and the composite external electron donor composition for olefin polymerization; the molar ratio of silicon in the alkoxysilane to titanium in the titanium catalyst is 150: 1.

Example 2

This embodiment provides an external electron donor, which includes 40 mol% of halogenated hydrocarbon, 20 mol% of aliphatic carboxylic acid ester, and 40 mol% of alkoxysilane; wherein the alkoxy silane is n-propyl trimethoxy silane; the halogenated hydrocarbon is a combination of chloropropane and chlorocyclohexane; the mol ratio of the chloropropane to the chlorocyclohexane is 3: 1; the aliphatic carboxylic acid ester is a combination of isopropyl myristate and di-n-butyl sebacate; the molar ratio of isopropyl myristate to di-n-butyl sebacate was 20: 1.

The embodiment provides an olefin polymerization catalyst system, which comprises a titanium catalyst, an alkyl aluminum compound and the composite external electron donor composition for olefin polymerization; the molar ratio of silicon in the alkoxysilane to titanium in the titanium catalyst is 100: 1.

Example 3

This embodiment provides an external electron donor, where the external electron donor includes, by mole, 35 mol% of a halogenated hydrocarbon, 30 mol% of an aliphatic carboxylic acid ester, and 35 mol% of an alkoxysilane; wherein the alkoxy silane is n-propyl trimethoxy silane; the halogenated hydrocarbon is a combination of chloropropane and chlorocyclohexane; the mol ratio of the chloropropane to the chlorocyclohexane is 6: 1; the aliphatic carboxylic acid ester is a combination of isopropyl myristate and di-n-butyl sebacate; the molar ratio of isopropyl myristate to di-n-butyl sebacate was 25: 1.

The embodiment provides an olefin polymerization catalyst system, which comprises a titanium catalyst, an alkyl aluminum compound and the composite external electron donor composition for olefin polymerization; the molar ratio of silicon in the alkoxysilane to titanium in the titanium catalyst is 200: 1.

Example 4

This embodiment provides an external electron donor, which includes 30 mol% of halogenated hydrocarbon, 25 mol% of aliphatic carboxylic acid ester, and 45 mol% of alkoxysilane; wherein the alkoxy silane is n-propyl trimethoxy silane; the halogenated hydrocarbon is a combination of chloropropane and chlorocyclohexane; the mol ratio of the chloropropane to the chlorocyclohexane is 1: 1; the aliphatic carboxylic acid ester is a combination of isopropyl myristate and di-n-butyl sebacate; the molar ratio of isopropyl myristate to di-n-butyl sebacate was 30: 1.

The embodiment provides an olefin polymerization catalyst system, which comprises a titanium catalyst, an alkyl aluminum compound and the composite external electron donor composition for olefin polymerization; the molar ratio of silicon in the alkoxysilane to titanium in the titanium catalyst is 500: 1.

Example 5

This embodiment provides an external electron donor, which includes 40 mol% of halogenated hydrocarbon, 20 mol% of aliphatic carboxylic acid ester, and 40 mol% of alkoxysilane; wherein the alkoxy silane is n-propyl trimethoxy silane; the halogenated hydrocarbon is a combination of chloropropane and chlorocyclohexane; the mol ratio of the chloropropane to the chlorocyclohexane is 10: 1; the aliphatic carboxylic acid ester is a combination of isopropyl myristate and di-n-butyl sebacate; the molar ratio of isopropyl myristate to di-n-butyl sebacate was 10: 1.

The embodiment provides an olefin polymerization catalyst system, which comprises a titanium catalyst, an alkyl aluminum compound and the composite external electron donor composition for olefin polymerization; the molar ratio of silicon in the alkoxysilane to titanium in the titanium catalyst is 10: 1.

Example 6

The only difference from example 1 is that the mole ratio of chloropropane to chlorocyclohexane is 0.5:1, and the composition is the same as that of example 1.

Example 7

The only difference from example 1 is that the mole ratio of chloropropane to chlorocyclohexane is 15:1, and the composition is the same as in example 1.

Example 8

The only difference from example 1 is that the halogenated hydrocarbon does not include chlorocyclohexane and includes only chloropropane, and the remaining composition is the same as in example 1.

Example 9

The only difference from example 1 is that the halogenated hydrocarbon does not include chloropropane, only chlorocyclohexane, and the remaining composition is the same as in example 1.

Example 10

The only difference from example 1 is that the halogenated hydrocarbon is bromobutane, and the composition is the same as that of example 1.

Example 11

The only difference from example 1 is that the halogenated hydrocarbon is iodomethylbenzene, and the composition is the same as in example 1.

Example 12

The only difference from example 1 is that the molar ratio of isopropyl myristate to di-n-butyl sebacate is 5:1, and the composition is the same as in example 1.

Example 13

The only difference from example 1 is that the molar ratio of isopropyl myristate to di-n-butyl sebacate is 50:1, and the composition is the same as in example 1.

Example 14

The only difference from example 1 is that the aliphatic carboxylic acid ester does not include di-n-butyl sebacate but includes isopropyl myristate, and the composition is the same as in example 1.

Example 15

The only difference from example 1 is that the aliphatic carboxylic acid ester does not include isopropyl myristate but includes di-n-butyl sebacate, and the remaining composition is the same as in example 1.

Example 16

The difference from example 1 is only that the aliphatic carboxylic acid ester is glyceryl tri (acetate), and the composition is the same as in example 1.

Example 17

The difference from example 1 is only that the aliphatic carboxylic acid ester is sec-octyl cyclohexanecarboxylate, and the composition is the same as that of example 1.

Example 18

The only difference from example 1 is that the alkoxysilane is dicyclopentyldimethoxysilane and the composition is the same as in example 1.

Example 19

The only difference from example 1 is that the alkoxysilane is methylcyclohexyldimethoxysilane and the composition is the same as in example 1.

Example 20

The only difference from example 1 is that the alkoxysilane is bis-o-tolyldiethoxysilane and the composition is the same as in example 1.

Example 21

The only difference from example 1 is that the alkoxysilane is tricyclopentylethoxysilane and the composition is the same as in example 1.

Example 22

The only difference from example 1 is that the molar ratio of silicon in the alkoxysilane to titanium in the titanium catalyst in the olefin polymerization catalyst system is 5:1, and the composition is the same as in example 1.

Example 23

The only difference from example 1 is that the molar ratio of silicon in the alkoxysilane to titanium in the titanium catalyst in the olefin polymerization catalyst system is 800:1, and the composition is the same as in example 1.

Example 24

The difference from example 1 is only that the external electron donor comprises 10 mol% of halogenated hydrocarbon, 40 mol% of aliphatic carboxylic acid ester and 50 mol% of alkoxysilane in terms of mole percent, and the rest of the composition is the same as example 1.

Example 25

The difference from example 1 is only that the external electron donor comprises a halogenated hydrocarbon in a molar percentage of 45 mol%, an aliphatic carboxylic acid ester in a molar percentage of 5 mol% and an alkoxysilane in a molar percentage of 50 mol%, and the remaining composition is the same as in example 1.

Comparative example 1

The difference from example 1 is that the external electron donor composition for olefin polymerization does not include chlorinated hydrocarbon and aliphatic carboxylic acid ester, includes only 100% alkoxysilane, and has the same composition as example 1.

Comparative example 2

The only difference from example 1 is that the external electron donor composition for olefin polymerization does not comprise an aliphatic carboxylic acid ester, and the mole percentages of chlorinated hydrocarbon and alkoxysilane are proportioned, i.e. the mole percentage of chlorinated hydrocarbon is 37.5%, the mole percentage of alkoxysilane is 62.5%, and the rest of the composition is the same as example 1.

Comparative example 3

The only difference from example 1 is that the external electron donor composition for olefin polymerization does not comprise chlorinated hydrocarbon, and the molar percentages of aliphatic carboxylate and alkoxysilane are proportioned, i.e. the molar percentage of aliphatic carboxylate is 28.5%, the molar percentage of alkoxysilane is 71.5%, and the rest of the composition is the same as example 1.

The olefin polymerization catalyst systems prepared in examples 1 to 25 and comparative examples 1 to 3 were subjected to polymerization activity, normalized activity, isotacticity and melt index tests:

polymerization Activity: the calculation is carried out by the following method, and the calculation formula is as follows:

wherein the unit of polymerization activity is gPP/gCat.h.

Normalized activity: the method is calculated by the following method, and the calculation formula is as follows:

wherein P (67) is the propylene concentration at 67 ℃, P (T) is the propylene concentration at temperature T, P (67)/P (T) is a concentration correction factor, and the propylene concentration correction factor P (67)/P (T) is: 67 ℃ (correction factor of 1), 90 ℃ (correction factor of 1.67), 100 ℃ (correction factor of 1.93), 110 ℃ (correction factor of 2.16), 120 ℃ (correction factor of 2.57).

Normalized activity ratio: AT/A67 is the normalized activity ratio.

And (3) isotacticity: and (3) measuring according to GB/T2546.1-2006, performing reflux extraction on a sample for 6 hours by using a Soxhlet extractor and normal heptane, performing vacuum drying on the extracted residues for 24 hours, weighing and calculating the percentage of the residues in the original mass to obtain the isotacticity.

Melt index: heating and vacuumizing a 2L glass high-pressure reaction kettle, replacing 3 times with nitrogen, cooling to room temperature, injecting 1L of anhydrous hexane solvent, starting stirring, adding 50mg of a main catalyst Shac320 component, wherein the Ti content in the catalyst is 2.5 wt%, adding triethylaluminum, adding an external electron donor component obtained by compounding in the examples 1-23 and the comparative examples 1-3, adding 0.01MPa of hydrogen, introducing propylene gas through a pressure reducing valve, increasing the pressure of a system to 0.5MPa, regulating the pressure of the introduced propylene to 0.5MPa through the pressure reducing valve in the process, and controlling the pressure of the system to be 0.5MPa all the time. Quickly heating the kettle to 67 ℃, starting polymerization, keeping the temperature unchanged in the polymerization process, after reacting for 1h, stopping stirring, emptying the system to normal pressure, opening a discharge hole at the bottom of the glass high-pressure reaction kettle to discharge the solvent and the product, killing an active center by using 100mL of alcohol, filtering and collecting a polypropylene product, drying for 24 hours in vacuum, weighing the total amount of the product after drying is finished, and measuring the melt index.

The test results are shown in table 1:

TABLE 1

The olefin polymerization catalytic system prepared by the invention has higher activity at normal reaction temperature, higher melt index and lower high-temperature reaction activity; as can be seen from a comparison of examples 1-5 and examples 6-7, when the molar ratio of chloropropane to chlorocyclohexane in the chlorinated hydrocarbon is outside the preferred range of the present invention (i.e., the molar ratio of chloropropane to chlorocyclohexane is (1-10):1), then the melt index of the olefin polymerization catalyst system will be lower, thereby affecting hydrogen response; as is apparent from a comparison of examples 1 to 5 and examples 8 to 9, when any one of chloropropane and chlorocyclohexane is not included in chlorinated hydrocarbon, the melt index of the olefin polymerization catalyst system is lowered, thereby affecting the hydrogen response; from the comparison of examples 1 to 5 with examples 10 to 11, it is clear that when the chloropropanes and chlorocyclohexanes are replaced by other chlorinated hydrocarbons, the melt index of the olefin polymerization catalyst system is greatly reduced, which affects the hydrogen response; as can be seen from the comparison of examples 1-5 and examples 12-13, when the molar ratio of isopropyl myristate to di-n-butyl sebacate is outside the preferred range of the present invention (i.e., the molar ratio of isopropyl myristate to di-n-butyl sebacate is (10-30):1), the normalized activity at 100 ℃ is affected; as is clear from comparison of examples 1 to 5 with examples 14 to 15, when the aliphatic carboxylic acid ester does not include either isopropyl myristate or di-n-butyl sebacate, the normalized activity at 100 ℃ is reduced to a smaller extent; as is clear from the comparison of examples 1 to 5 and examples 16 to 17, when isopropyl myristate and di-n-butyl sebacate were replaced with other aliphatic carboxylic acid esters, the reduction in normalized activity at 100 ℃ was particularly small; as is clear from the comparison of examples 1 to 5 and examples 18 to 21, when isopropyl myristate and di-n-butyl sebacate were replaced with other alkoxysilanes, the polymerization activity at 67 ℃ was lowered; as is apparent from a comparison of examples 1 to 5 and examples 22 to 23, when the molar ratio of silicon in the alkoxysilane to titanium in the titanium catalyst in the olefin polymerization catalyst system is out of the range specified in the present invention (i.e., the molar ratio of silicon in the alkoxysilane to titanium in the titanium catalyst is (10-500):1), the polymerization activity at 67 ℃ decreases; as can be seen from a comparison of example 1 and examples 24-25, the mole percentages of chlorinated hydrocarbons and aliphatic carboxylic acid esters in the external electron donor are outside the most preferred ranges, the ranges of 67 ℃ polymerization activity and 100 ℃ normalized activity are both varied, and the normalized activity ratio is increased; as can be seen from the comparison of examples 1-5 with comparative example 1, when the external electron donor composition for olefin polymerization does not include chlorinated hydrocarbon and aliphatic carboxylic acid ester, the overall performance of the olefin polymerization catalyst system may be reduced; as can be seen from the comparison of example 1 with comparative example 2, when the external electron donor composition for olefin polymerization does not include any one of aliphatic carboxylic acid esters, the normalized activity and the normalized activity ratio are affected; as can be seen from the comparison of example 1 and comparative example 3, when the external electron donor composition for olefin polymerization does not include chlorinated hydrocarbon, the melt index of the olefin polymerization catalyst system is lowered, thereby affecting the hydrogen response; therefore, the olefin polymerization catalytic system prepared by the method has higher activity at the conventional reaction temperature and melt index and lower high-temperature reaction activity.

The applicant declares that the above description is only a specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and it should be understood by those skilled in the art that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are within the scope and disclosure of the present invention.

Claims

1. An olefin polymerization catalyst system, characterized in that the olefin polymerization catalyst system comprises a titanium catalyst, an alkyl aluminum compound and an external electron donor;

the external electron donor comprises 30-40 mol% of halogenated hydrocarbon, 20-30 mol% of aliphatic carboxylic ester and 30-50 mol% of alkoxy silane;

the halogenated hydrocarbon comprises a combination of chloropropane and chlorocyclohexane;

the mol ratio of the chloropropane to the chlorocyclohexane is (1-10) to 1;

the aliphatic carboxylic acid ester comprises a combination of isopropyl myristate and di-n-butyl sebacate;

the mol ratio of isopropyl myristate to di-n-butyl sebacate is (10-30): 1;

the alkoxy silane is n-propyl trimethoxy silane;

the molar ratio of silicon in the alkoxysilane to titanium in the titanium catalyst is (10-500): 1.

2. The olefin polymerization catalyst system of claim 1 wherein the mole ratio of chloropropane to chlorocyclohexane is (3-6): 1.

3. The olefin polymerization catalyst system of claim 2 wherein the mole ratio of chloropropane to chlorocyclohexane is 5: 1.

4. The olefin polymerization catalyst system of claim 1 wherein the molar ratio of isopropyl myristate to di-n-butyl sebacate is (20-25): 1.

5. The olefin polymerization catalyst system of claim 4 wherein the molar ratio of isopropyl myristate to di-n-butyl sebacate is 22: 1.

6. The olefin polymerization catalyst system as recited in claim 1 wherein the molar ratio of silicon in said alkoxysilane to titanium in said titanium catalyst is (100-.

7. The olefin polymerization catalyst system of claim 6 wherein the molar ratio of silicon in the alkoxysilane to titanium in the titanium catalyst is 150: 1.

8. Use of the olefin polymerization catalyst system according to any of claims 1-7 in the polymerization of propylene.

9. Use according to claim 8, wherein the polymerization comprises homo-or copolymerization.