阅读说明：本技术 一种茂金属聚丙烯的制备方法及装置 (Method and device for preparing metallocene polypropylene ) 是由 宋莎 刘振宇 曹育才 朱红平 蒋文军 王伟哲 刘国禹 谢京燕 于 2019-10-30 设计创作，主要内容包括：本发明公开了茂金属聚丙烯的制备方法及装置。其中催化剂为桥联取代茚基化合物与助催化剂和载体负载而得到的茂金属催化剂。丙烯聚合采用本体法聚合工艺,解决了催化剂的加入途径问题,可以制备出茂金属聚丙烯,分子量分布为2-3,等规度[MMMM]大于99％,特别适用于无纺布、纺丝等方面的应用。(The invention discloses a preparation method and a device of metallocene polypropylene. Wherein the catalyst is a metallocene catalyst obtained by loading a bridged substituted indenyl compound, a cocatalyst and a carrier. The propylene polymerization adopts a bulk polymerization process, solves the problem of the addition route of the catalyst, can prepare the metallocene polypropylene, has the molecular weight distribution of 2-3 and the isotacticity [ MMMM ] of more than 99 percent, and is particularly suitable for application in the aspects of non-woven fabrics, spinning and the like.)

1. A process for preparing metallocene polypropylene includes bulk polymerizing reaction of propylene and optional hydrogen in the presence of catalyst, which contains metallocene compound as shown in formula 1, carrier and optional cocatalyst,

2. the process of claim 1 wherein the cocatalyst is selected from one or more of an aluminum alkyl, an alkylaluminoxane and an organic boride;

preferably, the alkyl aluminium is selected from one or more of trimethyl aluminium, triethyl aluminium and triisobutyl aluminium;

preferably, the alkylaluminoxane is selected from one or more of methylaluminoxane and ethylaluminoxane;

preferably, the organic boron compound is selected from one or more of trifluoroborane, triphenylborane, tris (4-fluorophenyl) borane, tris (pentafluorophenyl) borane, tris (3, 5-difluorophenyl) borane and tris (2,4, 6-trifluorophenyl) borane;

preferably, the molar ratio of the metallocene compound and the cocatalyst, calculated as the ratio of zirconium to aluminum, is (200-3000): 1, more preferably (400- & ltwbr- & gt 600): 1.

3. the method according to claim 1 or 2, wherein the support is selected from SiO₂、MgCl₂And Al₂O₃One or more of (a).

4. The process according to any one of claims 1 to 3, wherein the reaction temperature of the reaction is-50 to 200 ℃, preferably 65 to 80 ℃;

and/or the reaction time is 0.016-60 h, preferably 3-7 h.

5. The process according to any one of claims 1 to 4, wherein the catalyst is used in an amount of 0.00001 to 100mg/g propylene, preferably 0.0001 to 10mg/g propylene;

and/or the dosage of the impurity breaking agent is 0-100 mmol/g propylene, preferably 0.001-10 mmol/g propylene;

and/or the amount of the hydrogen is 0-0.10 g/g of propylene, preferably 0.0001-0.01 g/100g of propylene.

6. The method according to any one of claims 1 to 5, wherein the feed lines for the catalyst and the impurity breaking agent are protected by an inert gas selected from one or more of nitrogen and argon;

and/or the addition of the catalyst and the impurity breaking agent is realized by the pressure difference of gas.

7. The process of any of claims 1-6, wherein the propylene has a purity of greater than 96%;

and/or the purity of the hydrogen is greater than 98%.

8. The preparation device of the metallocene polypropylene comprises a reaction kettle, wherein a metering device for accurately calculating the mass of the added cocatalyst is arranged on the reaction kettle, and preferably, the metering device is a precise electronic scale.

9. The apparatus of claim 8, wherein the reaction kettle is provided with a catalyst inlet and a propylene gas inlet in sequence.

10. The apparatus according to claim 8 or 9, wherein a discharge pipeline for materials is arranged at the bottom of the reaction kettle, and a discharge valve is arranged on the discharge pipeline.

Technical Field

The invention relates to the field of metallocene polypropylene, and relates to a preparation method and a preparation device of metallocene polypropylene.

Background

Polypropylene (PP) has become one of the most widely used plastics in the world with the greatest yield due to its advantages of low density, good chemical stability, no toxicity, easy processing, good mechanical properties, wide raw material source, low price, etc. The traditional polypropylene is mainly produced by the traditional Ziegler Natta catalyst, and the emerging metallocene polypropylene (mPP) has special properties of narrow molecular weight distribution, adjustable melt index height and the like, and is concerned.

In the 90 s of the 20 th century, the industrial production of mPP began to develop vigorously, and ExxonMobil company utilized EXXPOL single-site catalyst to build a set of 100kt/a industrial devices, and adopted a bulk method and a slurry method to produce metallocene isotactic polypropylene with the trade name Achieve. At present, metallocene polypropylene purchased in the market is developed by foreign companies, so that the development of high-performance polypropylene by using the existing propylene resources is significant.

Disclosure of Invention

The first aspect of the present invention provides a method for preparing metallocene polypropylene, comprising performing bulk polymerization reaction on propylene and optionally hydrogen as raw materials in the presence of a catalyst, wherein the catalyst comprises a metallocene compound represented by formula 1, a support and optionally a cocatalyst,

according to some embodiments of the invention, the cocatalyst is selected from one or more of an aluminum alkyl, an alkylaluminoxane, and an organic boride;

preferably, the alkyl aluminium is selected from one or more of trimethyl aluminium, triethyl aluminium and triisobutyl aluminium;

preferably, the alkylaluminoxane is selected from one or more of methylaluminoxane and ethylaluminoxane;

preferably, the organic boron compound is selected from one or more of trifluoroborane, triphenylborane, tris (4-fluorophenyl) borane, tris (pentafluorophenyl) borane, tris (3, 5-difluorophenyl) borane and tris (2,4, 6-trifluorophenyl) borane;

preferably, the molar ratio of the metallocene compound and the cocatalyst, calculated as the ratio of zirconium to aluminum, is (200-3000): 1, more preferably (400- & ltwbr- & gt 600): 1.

according to some embodiments of the invention, the reaction temperature of the reaction is-50 to 200 ℃, preferably 65 to 80 ℃.

According to some embodiments of the invention, the reaction time is 0.016 to 60 hours, preferably 3 to 7 hours.

According to some embodiments of the invention, the catalyst is used in an amount of 0.00001 to 100mg/g propylene, preferably 0.0001 to 10mg/g propylene.

According to some embodiments of the present invention, the amount of the impurity breaking agent is 0 to 100mmol/g of propylene, preferably 0.001 to 10mmol/g of propylene.

According to some embodiments of the present invention, the hydrogen is used in an amount of 0 to 0.10g/g propylene, preferably 0.0001 to 0.01g/100g propylene.

According to some embodiments of the invention, the feed lines for the catalyst and the impurity breaker are protected by an inert gas selected from one or more of nitrogen and argon.

According to some embodiments of the invention, the addition of the catalyst and the impurity breaker is effected by means of a pressure difference of the gases.

According to some embodiments of the invention, the propylene has a purity of greater than 96%.

According to some embodiments of the invention, the hydrogen gas has a purity of greater than 98%.

The second aspect of the present invention provides an apparatus for preparing metallocene polypropylene, comprising a reaction kettle, wherein a metering device for accurately calculating the mass of the added cocatalyst is arranged on the reaction kettle, and preferably, the metering device is a precision electronic scale.

According to some embodiments of the invention, the reaction vessel is provided with a catalyst inlet and a propylene gas inlet in sequence.

According to some embodiments of the invention, the bottom of the reaction vessel is provided with a discharge line for material, on which a discharge valve is mounted.

The invention has the beneficial effects that:

(1) the metallocene compound and the prepared supported metallocene catalyst are polymerized by a bulk method to realize the preparation of metallocene polypropylene, and the obtained polypropylene has narrow molecular distribution (2-3), no peculiar smell and uniform particles. The preparation of polypropylene with different melt indexes can be realized by adjusting the adding amount of hydrogen.

(2) The self-contained design of the autoclave results in a reactor with the following advantages:

a catalyst feeding port and a feeding mode are designed and modified, so that the activity of the catalyst is well protected, and the catalyst is conveniently added; an auxiliary agent feeding port and a feeding mode are designed and modified, the using amount of the cocatalyst can be accurately metered by using a precise electronic scale, and the cocatalyst is conveniently added; the polypropylene discharge port is more convenient.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention and not to limit the invention. In the drawings:

FIG. 1 is a schematic view of the structure of an apparatus for producing a metallocene polypropylene according to an embodiment of the present invention.

Detailed Description

The present invention will be described in detail with reference to examples, but the present invention is not limited to the examples.

Wherein MAO is methylaluminoxane.

The test method comprises the following steps:

polymerization activity (mass of polyolefin produced)/(number of moles of zirconium in catalyst × reaction time), g/(mol · h) Mn, Mw, PDI value: measured by high temperature GPC.

Percentage of isotactic sequence [ mmmm ] containing 5 consecutive isotactic units: 13C NMR spectroscopy.

1 metallocene polypropylene preparation equipment:

on the basis of a purchased polymerization reaction kettle, the independent design of the high-pressure kettle is carried out again, and the design comprises a main catalyst and cocatalyst feeding port and a feeding mode. And a catalyst feeding port is additionally arranged at the upper part of the reaction kettle, the inert gas is used for protection, and the effective addition of the catalyst is realized by utilizing the pressure difference of the inert gas. The amount of cocatalyst was measured using a precision electronic scale. So that the addition and the metering of the catalyst are more convenient and accurate. The autoclave used is shown in figure 1, and the top is provided with a catalyst and cocatalyst feeding port, a raw material gas injection port and a nitrogen injection port. The catalyst and the impurity breaking agent are protected by inert gas, and the effective addition of the catalyst is realized by utilizing the pressure difference of the inert gas. The amount of cocatalyst was measured using a precision electronic scale. So that the addition and the metering of the catalyst are more convenient and accurate. The bottom is provided with a discharge pipeline for materials, and a discharge valve is arranged on the pipeline.

2 preparation of metallocene Compounds

2g of silica gel calcined at 600 ℃ was weighed, 10mL of MAO (methylaluminoxane) in toluene (10% wt) was added, and the mixture was heated to 80 ℃. While stirring uniformly, a toluene solution of the metallocene compound represented by formula 1 was added thereto, and the Al/Zr ratio was controlled to 200:1, and the reaction was allowed to proceed overnight. The solid was collected by filtration and washed with a toluene solvent until the washed solvent was colorless, and the solid was dried under vacuum for 24 hours to give a solid powder which was stored in a glove box for further use (this reaction procedure was used hereinafter unless otherwise specified). Through the calculation of the metal content of the fed amount and the washing liquid, the catalyst with determined metal content can be obtained, wherein the zirconium content is 0.268% (29.4 mu mol/g).

3, preparation of the catalyst: supports for metallocene compounds

Weighing 15g of MAO silica gel under anhydrous and oxygen-free conditions, and adding 30mL of toluene until the MAO silica gel is completely dissolved to obtain a solution A;

dissolving another 6g of the prepared metallocene compound in 15mL of toluene, adding the solution A into the solution A, reacting for more than 5h at room temperature, and performing suction filtration and drying to obtain the catalyst. And (5) standby.

4 preparation of metallocene Polypropylene

The first embodiment is as follows:

selecting a 2L high-pressure reaction kettle, and working before polymerization: 1. testing the pressure to ensure that the sealing performance of the whole set of device is good; 2. heating to 120 ℃ to ensure that the vapor impurities in the kettle are removed; 3. the nitrogen was replaced 3 times.

30mg of the prepared catalyst was weighed, 15mL of a triisobutylaluminum solution (concentration: 150. mu. mol/mL, molar ratio of aluminum to zirconium: about 549:1) was added, 0.034g of hydrogen was added by a mass flow meter, the reaction time was 420 minutes, the reaction temperature was 75 ℃, and the amount of propylene was 680.2g by a mass flow meter.

540g of polymer were obtained, the polymerization activity being calculated to be 4.3X 10⁸g(PP)·mol^-1(Zr)·h^-1Mn 135427, Mw 397892, PDI 2.938 by high temperature GPC; high temperature 13C NMR spectroscopy measured isotactic sequence [ mmmm ] containing 5 consecutive isotactic units]The percentage content of (B) is 98.4%. The melting point test value was 153.2 ℃.

Example two:

selecting a 2L high-pressure reaction kettle, and working before polymerization: 1. testing the pressure to ensure that the sealing performance of the whole set of device is good; 2. heating to 120 ℃ to ensure that the vapor impurities in the kettle are removed; 3. the nitrogen was replaced 3 times.

105mg of the prepared catalyst and 8mL of triisobutylaluminum (the concentration is 150. mu. mol/mL, the molar ratio of aluminum to zirconium is about 549:1) were weighed, 0.034g of hydrogen was added by using a mass flow meter, the reaction time was 180 minutes, the reaction temperature was 75 ℃, and 468g of propylene was added by using a mass flow meter.

80g of polymer were obtained, the polymerization activity being calculated to be 1.16X 10⁷g(PP)·mol^-1(Zr)·h^-1. Mn of 133064, Mw of 313745 and PDI of 2.36 as determined by high temperature GPC; high temperature¹³C NMR spectra measured isotactic sequence [ mmmm ] containing 5 successive isotactic units]The percentage content of (B) is 99.3%. The melting point test value was 149.4 ℃.

Example three:

selecting a 2L high-pressure reaction kettle, and working before polymerization: 1. testing the pressure to ensure that the sealing performance of the whole set of device is good; 2. heating to 120 ℃ to ensure that the vapor impurities in the kettle are removed; 3. the nitrogen was replaced 3 times.

100mg of the prepared catalyst and 15mL of triisobutylaluminum (the concentration is 150 mu mol/mL, the molar ratio of aluminum to zirconium is about 549:1) are weighed, 0.034g of hydrogen is added by using a mass flow meter, the reaction time is 240 minutes, the reaction temperature is 75 ℃, and 539g of propylene is added by using the mass flow meter.

447g of polymer were finally obtained, the polymerization activity being calculated as 2.294X 10⁷g(PP)·mol^-1(Zr)·h^-1. Mn measured by high temperature GPC was 198563, Mw was 398423, and PDI value was 2.01; high temperature¹³C NMR spectra measured isotactic sequence [ mmmm ] containing 5 successive isotactic units]The percentage content of (B) is 99.2%. The melting point test value was 157.1 ℃.

Example four:

selecting a 2L high-pressure reaction kettle, and working before polymerization: 1. testing the pressure to ensure that the sealing performance of the whole set of device is good; 2. heating to 120 ℃ to ensure that the vapor impurities in the kettle are removed; 3. the nitrogen was replaced 3 times.

60mg of the prepared catalyst and 20mL of triisobutylaluminum (the concentration is 150 mu mol/mL, the molar ratio of aluminum to zirconium is about 1103:1) are weighed, 0.026g of hydrogen is added by using a mass flow meter, the reaction time is 240 minutes, the reaction temperature is 75 ℃, and 659g of propylene is added by using the mass flow meter.

600g of polymer were obtained, the polymerization activity being calculated to be 4.9X 10⁷g(PP)·mol^-1(Zr)·h^-1. Melt index MI 5.39g/10min, Mn 178563 by high temperature GPC, Mw 399423, PDI 2.24; high temperature¹³C NMR spectra measured isotactic sequence [ mmmm ] containing 5 successive isotactic units]The percentage content of (B) is 99.2%. The melting point test value was 152.24 ℃.

Example five:

selecting a 2L high-pressure reaction kettle, and working before polymerization: 1. testing the pressure to ensure that the sealing performance of the whole set of device is good; 2. heating to 120 ℃ to ensure that the vapor impurities in the kettle are removed; 3. the nitrogen was replaced 3 times.

30mg of the prepared catalyst and 20mL of triisobutylaluminum (the concentration is 150 mu mol/mL, the molar ratio of aluminum to zirconium is about 2389:1) are weighed, 0.026g of hydrogen is added by using a mass flow meter, the reaction time is 240 minutes, the reaction temperature is 75 ℃, and 658.8g of propylene is added by using the mass flow meter.

390g of polymer were finally obtained, the polymerization activity being calculated to be 5.2X 10⁷g(PP)·mol^-1(Zr)·h^-1. Mn 98318, Mw 285601, PDI 2.91 as determined by high temperature GPC; high temperature¹³C NMR spectra measured isotactic sequence [ mmmm ] containing 5 successive isotactic units]The percentage content of (B) is 97.2%. The melting point test value was 147.9 ℃.

It should be noted that the above-mentioned embodiments are only for explaining the present invention, and do not constitute any limitation to the present invention. The present invention has been described with reference to exemplary embodiments, but the words which have been used herein are words of description and illustration, rather than words of limitation. The invention can be modified, as prescribed, within the scope of the claims and without departing from the scope and spirit of the invention. Although the invention has been described herein with reference to particular means, materials and embodiments, the invention is not intended to be limited to the particulars disclosed herein, but rather extends to all other methods and applications having the same functionality.