CN1621423A - Process for preparing linear low density polyethylene - Google Patents
Process for preparing linear low density polyethylene Download PDFInfo
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- CN1621423A CN1621423A CN 200310116909 CN200310116909A CN1621423A CN 1621423 A CN1621423 A CN 1621423A CN 200310116909 CN200310116909 CN 200310116909 CN 200310116909 A CN200310116909 A CN 200310116909A CN 1621423 A CN1621423 A CN 1621423A
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- catalyst
- copolymerization
- oligomerization
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Abstract
The catalyst system for in-situ copolymerization to prepare linear low-density polyethylene consists of oligomerization catalyst of homogeneous or supported alpha-bisimido pyridine iron compound and copolymerization catalyst of homogeneous or supported metallocene compound. The unique ethylene material is first produced into alpha-olefin in the presence of alkyl aluminoxane catalyst; and linear low-density polyethylene is then prepared through the in-situ copolymerization of ethylene. The prepared linear low-density polyethylene has low smelting point, low density, relatively high monomer inserting rate and other features.
Description
Technical field
The present invention relates to a kind of method for preparing linear low density polyethylene (LLDPE).
Background technology
Realize that with metallocene catalyst or constrained geometry catalyst the copolymerization LLDPE of ethene and alpha-olefin is a research focus in the last few years, required is generated by ethylene oligomerization usually, obtains hexene, octene, decene etc. through rectifying then.If can adopt a kind of in-situ copolymerization catalyst system, promptly in reaction system with catalyst for oligomerization by ethene at first oligomerisation be that alpha-olefin adds catalyst for copolymerization then, generate LLDPE with in-situ copolymerization then.This will simplify production technique, solves the problem of the main dependence on import of domestic alpha-olefin simultaneously, reduces production costs greatly.
Traditional Ziegler-Natta catalyst is applied to ethene and the fashionable LLDPE that can not obtain high insertion rate of alpha-olefin copolymer, and is poorer for high carbon number alpha-olefin copolymer performance.And the methylaluminoxane of finding at the eighties Kaminsky (MAO) can improve catalytic activity and polymeric copolymerization performance (Angew.Chem.Int.Ed.Engl.19,396 (1980)) thereof as the promotor of metallocene.At present, the multipolymer by metallocene catalysts ethene and propylene, high carbon number alpha-olefin is the research focus of polyolefine material.In recent years, emerging constrained geometry catalyst then is present ideal copolymerization catalyst for ethylene.Bazan [J.Am.Chem.Soc.120,7143 (1998)] design synthetic (C
6H
5B-OEt)
2ZrCl
2Can under the effect of MAO, the catalyzed ethylene oligomerisation close, obtain ethylene oligomer, and then utilize constrained geometry catalyst and in-situ copolymerization, successfully obtain LLDPE.But, its maximum shortcoming is the alpha-olefin poor selectivity of its ethylene oligomerization catalyst instability that adopts and catalyzer, selectivity is 40-90%, its oligomerization product is the 1-alkene, 2-alkyl-1-alkene and 2-alkene, wherein, 2-alkyl-1-alkene and 2-alkene can not form copolymerization product with ethene.
In addition, Bazan[Macromolecules, 34 (2001) 2411] to have studied novel alpha-diimine pyridine iron be title complex carries out cascade reaction as catalyst for oligomerization and ethyl bridged indene base zirconium dichloride as catalyst for copolymerization and prepares LLDPE, because the carbon number distribution broad of the catalyst for oligomerization gained oligopolymer that adopts, the oligopolymer of residual high carbon number in polymkeric substance easily.
Summary of the invention
The present invention is based on above-mentioned technical background, adopting the novel alpha-diimine pyridine iron with high reactivity, highly selective is that (alpha-olefin selection rate＞95%, carbon number distribution are C to title complex as catalyst for oligomerization
4～C
30, be mainly C
4～C
10(＞80%)), as catalyst for copolymerization, be only monomer with metallocene catalyst with ethene, alkylaluminoxane is unique promotor, carry out the ethene in-situ polymerization and prepared LLDPE, solve the deficiency in the above-mentioned research, emphasis has solved the residual problem of high carbon number alpha-olefin.
The catalyst for oligomerization that the present invention relates to is that the novel alpha-diimine pyridine iron of homogeneous phase or loading type is a title complex, and its molecular structural formula is as follows:
R
1＝-H，-CH
3
R
2＝-F，-Cl，-Br，-I
R
3＝-CH
3，-CH
2CH
3，-CH(CH
3)
2，-OCH
3，-Br，-Cl，-F
R
4＝-F，-H
X＝-Br，-Cl
The catalyst for copolymerization that the present invention relates to is for being the cyclopentadienyl compound of central atom or their supported catalyst with Ti, Zr or Hf.The cyclopentadienyl compound can be single bridging, doube bridge connection or non-bridge crosslinking structure, is that the central atom metallocene is best with the Zr of bridging, and these compounds are Et (Ind)
2ZrCl
2, Me
2Si (Ind)
2ZrCl
2, Et (Ind)
2ZrMe
2, Me
2Si (Ind)
2ZrMe
2, Cp*SiMe
2NBu
tZrCl
2, Cp*SiMe
2NBu
tTiCl
2, or IndSiMe
2NBu
tZrCl
2Deng.
The loading type oligomerisation that the present invention relates to, the raw material carrier of catalyst for copolymerization are organic carrier or inorganic carrier, generally mostly are porous carrier.The example of non-limiting scope is as SiO
2, MgCl
2, Al
2O
3, talcum, zeolite, polynite, polyethylene or polystyrene etc.The granular size of carrier is 0.1-1000 μ m, and specific surface area is 60-500m
2/ g, pore volume are 0.1-7.0cc/g, and the aperture is 30-700 .
The promotor that the present invention relates to is an alkylaluminoxane, as methylaluminoxane (MAO), ethyl aikyiaiurnirsoxan beta (EAO) or isobutyl aluminium alkoxide (iBAO) etc.
The present invention adopts bifunctional catalyst system directly to be followed these steps to carry out by the preparation method of the synthetic LLDPE of ethene:
1. the reaction vessel that agitator will be housed with nitrogen and ethene displacement, feeds ethene respectively then, adds the toluene through the deoxidation of sodium Metal 99.5 reflux dewatering, and add-on is that half of vessel volume gets final product, and vessel temp is at 0-100 ℃, and more satisfactory is 30-70 ℃,
2. stir the catalyst for oligomerization that adds alkylaluminoxane promotor and homogeneous or load down in regular turn, reacted 0-30 minute;
3. the co-catalyst that adds homogeneous or load;
4. add the ethanol solution hydrochloride termination reaction of 10% (volume ratio), obtain the LLDPE product through washing with alcohol, vacuum-drying.
The in-situ copolymerization catalyst system of a kind of preparation linear low density polyethylene of the present invention (LLDPE) has following feature:
1. the catalyst for oligomerization of the present invention's employing is that homogeneous phase or loading type alpha-diimine pyridine iron are title complex, and its chemical molecular structural formula is as follows:
R
1＝-H，-CH
3
R
2＝-F，-Cl，-Br，-I
R
3＝-CH
3，-CH
2CH
3，-CH(CH
3)
2，-OCH
3，-Br，-Cl，-F
R
4＝-F，-H
X＝-Br，-Cl
2. the catalyst for copolymerization of the present invention's employing is that homogeneous phase or carried metallocene catalyst: Ti, Zr or Hf are the cyclopentadienyl compound of central atom.The cyclopentadienyl compound can be single bridging, doube bridge connection or non-bridge crosslinking structure, is that the central atom metallocene is best with the Zr of bridging, and these compounds are Et (Ind)
2ZrCl
2, Me
2Si (Ind)
2ZrCl
2, Et (Ind)
2ZrMe
2, Me
2Si (Ind)
2ZrMe
2, Cp*SiMe
2NBu
tZrCl
2, Cp*SiMe
2NBu
tTiCl
2, or IndSiMe
2NBu
tZrCl
2Deng.
3. the catalyst for oligomerization of the present invention's employing and the mol ratio of catalyst for copolymerization are 1: 20 ~ 10: 1, and the best is 1: 10～2: 1.
4. the loading type catalyst for oligomerization and the employed carrier of catalyst for copolymerization of the present invention's employing are organic carrier or inorganic carrier, as SiO
2, MgCl
2, Al
2O
3, talcum, zeolite, polynite, polyethylene or polystyrene etc., be preferably SiO
2
5. the promotor of the present invention's employing is an alkylaluminoxane, as methylaluminoxane (MAO), ethyl aikyiaiurnirsoxan beta (EAO) or isobutyl aluminium alkoxide (iBAO) etc., wherein is best with MAO.Keep Al/ (Fe+Zr or Ti) mol ratio=500: 1 ~ 5000: 1, the best is 1000: 1 ~ 3000: 1.
6. polymerization system of the present invention has advantages of high catalytic activity, and product has than low melting point and lower degree of crystallinity, and its melting range is 97.8-124.9 ℃, and its degree of crystallinity scope is 16.7-65.8%, and density range is at 0.910-0.940g/cm
3
Embodiment
Embodiment 1
1) all under the condition of anhydrous and oxygen-free, all solvents all require dehydration and deoxidation to handle to all operations.
2) A: catalyst for oligomerization
B: catalyst for copolymerization Et (Ind)
2ZrCl
2
C: promotor MAO
3) a 250mL there-necked flask that agitator is housed is replaced with nitrogen and ethene respectively, feed ethene then, add 100mL toluene, be warming up to 50 ℃, stir adding MAO[Al/ (Fe+Zr)=2000: 1 (mol ratio) down], stir after 2 minutes, add catalyst for oligomerization A, reacted 2 minutes;
4) add co-catalyst B, catalyst for oligomerization/co-catalyst mol ratio 1: 20, the ethylene pressure in keeping bottle is under the condition of 770mmHg, polymerase 10 .5 hour;
5) the ethanol solution hydrochloride termination reaction of adding 10% (volume ratio) obtains the LLDPE product through washing with alcohol, vacuum-drying.Its operational condition and polymer property are listed in the table 1.
Embodiment 2
1) all under the condition of anhydrous and oxygen-free, all solvents all require dehydration and deoxidation to handle to all operations.
2) A: catalyst for oligomerization
B: catalyst for copolymerization, SiO
2Loading type Et (Ind)
2ZrCl
2
C: promotor MAO
3) a 250mL there-necked flask that agitator is housed is replaced with nitrogen and ethene respectively, feed ethene then, add 100mL toluene, be warming up to 100 ℃, stir adding MAO[Al/ (Fe+Zr)=1000: 1 (mol ratio) down], stir after 2 minutes, add catalyst for oligomerization A, reacted 10 minutes;
4) add co-catalyst B (Zr content 0.0050gZr/g supported catalyst), catalyst for oligomerization/co-catalyst mol ratio 10: 1, the ethylene pressure in keeping bottle is under the condition of 770mmHg, polymerase 10 .5 hour;
5) the ethanol solution hydrochloride termination reaction of adding 10% (volume ratio) obtains the LLDPE product through washing with alcohol, vacuum-drying.Its operational condition and polymer property are listed in the table 1.
Embodiment 3
1) all under the condition of anhydrous and oxygen-free, all solvents all require dehydration and deoxidation to handle to all operations.
2) A: catalyst for oligomerization
B: catalyst for copolymerization Et (Ind)
2ZrCl
2
C: promotor MAO
3) a 250mL there-necked flask that agitator is housed is replaced with nitrogen and ethene respectively, feed ethene then, add 100mL toluene, be warming up to 0 ℃, stir and add MAO[Al/ (Fe+Zr)=2000: 1 (mol ratio) down], stir after 2 minutes, add catalyst for oligomerization A;
4) add co-catalyst B immediately, catalyst for oligomerization/co-catalyst mol ratio 1: 1, the ethylene pressure in keeping bottle is under the condition of 770mmHg, polymerization 1 hour;
5) the ethanol solution hydrochloride termination reaction of adding 10% (volume ratio) obtains the LLDPE product through washing with alcohol, vacuum-drying.Its operational condition and polymer property are listed in the table 1.
Embodiment 4
1) all under the condition of anhydrous and oxygen-free, all solvents all require dehydration and deoxidation to handle to all operations.
2) A: catalyst for oligomerization
B: catalyst for copolymerization Et (Ind)
2ZrCl
2
C: promotor MAO
3) a 250mL there-necked flask that agitator is housed is replaced with nitrogen and ethene respectively, feed ethene then, add 100mL toluene, be warming up to 50 ℃, stir adding MAO[Al/ (Fe+Zr)=2000: 1 (mol ratio) down], stir after 2 minutes, add catalyst for oligomerization A, reacted 2 minutes;
4) add co-catalyst B, catalyst for oligomerization/co-catalyst mol ratio 1: 10, the ethylene pressure in keeping bottle is under the condition of 770mmHg, polymerase 10 .5 hour;
5) the ethanol solution hydrochloride termination reaction of adding 10% (volume ratio) obtains the LLDPE product through washing with alcohol, vacuum-drying.Its operational condition and polymer property are listed in the table 1.
Embodiment 5
1) all under the condition of anhydrous and oxygen-free, all solvents all require dehydration and deoxidation to handle to all operations.
2) A: catalyst for oligomerization
B: catalyst for copolymerization Et (Ind)
2ZrCl
2
C: promotor MAO
3) a 250mL there-necked flask that agitator is housed is replaced with nitrogen and ethene respectively, feed ethene then, add 100mL toluene, be warming up to 50 ℃, stir adding MAO[Al/ (Fe+Zr)=2000: 1 (mol ratio) down], stir after 2 minutes, add catalyst for oligomerization A, reacted 2 minutes;
4) add co-catalyst B, catalyst for oligomerization/co-catalyst mol ratio 5: 1, the ethylene pressure in keeping bottle is under the condition of 770mmHg, polymerization 1 hour;
5) the ethanol solution hydrochloride termination reaction of adding 10% (volume ratio) obtains the LLDPE product through washing with alcohol, vacuum-drying.Its operational condition and polymer property are listed in the table 1.
Embodiment 6
1) all under the condition of anhydrous and oxygen-free, all solvents all require dehydration and deoxidation to handle to all operations.
2) A: catalyst for oligomerization
B: catalyst for copolymerization Et (Ind)
2ZrCl
2
C: promotor MAO
3) a 250mL there-necked flask that agitator is housed is replaced with nitrogen and ethene respectively, feed ethene then, add 100mL toluene, be warming up to 50 ℃, stir adding MAO[Al/ (Fe+Zr)=3000: 1 (mol ratio) down], stir after 2 minutes, add catalyst for oligomerization A, reacted 10 minutes;
4) add co-catalyst B, catalyst for oligomerization/co-catalyst mol ratio 1: 10, the ethylene pressure in keeping bottle is under the condition of 770mmHg, polymerization 1 hour;
5) the ethanol solution hydrochloride termination reaction of adding 10% (volume ratio) obtains the LLDPE product through washing with alcohol, vacuum-drying.Its operational condition and polymer property are listed in the table 1.
Embodiment 7
1) all under the condition of anhydrous and oxygen-free, all solvents all require dehydration and deoxidation to handle to all operations.
2) A: catalyst for oligomerization
B: catalyst for copolymerization Me
2Si (Ind)
2ZrCl
2
C: promotor MAO
3) a 250mL there-necked flask that agitator is housed is replaced with nitrogen and ethene respectively, feed ethene then, add 100mL toluene, be warming up to 50 ℃, stir adding MAO[Al/ (Fe+Zr)=2000: 1 (mol ratio) down], stir after 2 minutes, add catalyst for oligomerization A, reacted 5 minutes;
4) add co-catalyst B, catalyst for oligomerization/co-catalyst mol ratio 1: 10, the ethylene pressure in keeping bottle is under the condition of 770mmHg, polymerization 1 hour;
5) the ethanol solution hydrochloride termination reaction of adding 10% (volume ratio) obtains the LLDPE product through washing with alcohol, vacuum-drying.Its operational condition and polymer property are listed in the table 1.
Embodiment 8
1) all under the condition of anhydrous and oxygen-free, all solvents all require dehydration and deoxidation to handle to all operations.
2) A: catalyst for oligomerization
B: catalyst for copolymerization Cp*SiMe
2NBu
tZrCl
2
C: promotor MAO
3) a 250mL there-necked flask that agitator is housed is replaced with nitrogen and ethene respectively, feed ethene then, add 100mL toluene, be warming up to 70 ℃, stir adding MAO[Al/ (Fe+Zr)=2000: 1 (mol ratio) down], stir after 2 minutes, add catalyst for oligomerization A, reacted 10 minutes;
4) add co-catalyst B, catalyst for oligomerization/co-catalyst mol ratio 1: 20, the ethylene pressure in keeping bottle is under the condition of 770mmHg, polymerase 10 .5 hour;
5) the ethanol solution hydrochloride termination reaction of adding 10% (volume ratio) obtains the LLDPE product through washing with alcohol, vacuum-drying.Its operational condition and polymer property are listed in the table 1.
Polymerizing condition among table 1. embodiment and aggregated data
The oligomerisation copolymerization
Real catalysis catalysis promotor/urge crystal density
The catalyst activity fusing point
Execute agent thinner agent degree (g/cm
3
The property
a(℃)
Example (μ mo (μ mol (mol/mol) (%))
1) )
1 0.4 0.4 2000 9.94 114.3 29.8 0.923
2 0.4 1 1000 2.85 123. 36.6 0.938
0
3 0.2 0.4 2000 11.1 115. 29.8 0.929
7
4 0.6 0.3 2000 7.62 97.8 16.7 0.914
5 0.8 0.2 2000 3.08 115. 39.8 0.935
4
6 0.3 0.6 2000 9.88 116. 31.8 0.930
1
7 0.4 0.4 2000 6.53 122. 43.6 0.933
3
8 0.6 0.3 2000 4.42 116. 38.0 0.932
2
aCatalyst activity: 10
6GPEmol
-1(Fe+Zr) h
-1Atm
-
Claims (5)
1. the preparation method of a linear low density polyethylene, directly by the ethene synthesizing linear low-density polyethylene, key step is under the catalyst system effect that ethylene oligomerization catalyst, catalyst for copolymerization and promotor are formed:
A) reaction vessel with the displacement of nitrogen and ethene, feeds ethene respectively then, add the toluene handled through dehydration and deoxidation to the reaction vessel volumetrical half, vessel temp is 0-100 ℃;
B) stirring adds promotor and catalyst for oligomerization, oligomerisation 0-30min down successively; Promotor is an alkylaluminoxane, its add-on is 500-5000 by Al/ (Fe+Zr or Ti) mol ratio: 1, catalyst for oligomerization is that the alpha-diimine pyridine iron of homogeneous phase or loading type is a title complex, and the mol ratio of catalyst for copolymerization is 1 in add-on and the following step: 20-10: 1;
C) catalyst for copolymerization is added in the reaction vessel polymerase 10 .5-1 hour; Catalyst for copolymerization is homogeneous phase or carried metallocene catalyst;
D) 10% acidic alcohol termination reaction of adding reactant volume is used the washing with alcohol polymkeric substance, and vacuum-drying obtains target product.
2. the method for claim 1 is characterized in that, vessel temp is 30-70 ℃ among the step a.
3. the method for claim 1 is characterized in that, described promotor is methylaluminoxane, ethyl aikyiaiurnirsoxan beta or isobutyl aluminium alkoxide.
4. the method for claim 1, its spy is characterised in that the add-on of described promotor is 1000-3000 by Al/ (Fe+Zr or Ti) mol ratio: 1.
5. the method for claim 1 is characterized in that, the mol ratio of described catalyst for oligomerization/catalyst for copolymerization is 1: 10-2: 1.
Priority Applications (1)
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|---|---|---|---|
| CN 200310116909 CN1621423A (en) | 2003-11-28 | 2003-11-28 | Process for preparing linear low density polyethylene |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200310116909 CN1621423A (en) | 2003-11-28 | 2003-11-28 | Process for preparing linear low density polyethylene |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN1621423A true CN1621423A (en) | 2005-06-01 |
Family
ID=34760819
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|---|---|---|---|
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100543048C (en) * | 2005-09-22 | 2009-09-23 | 中国科学院化学研究所 | A kind of catalyst system of in-situ copolymerizing linear low-density polyethylene |
| US20100016529A1 (en) * | 2005-04-29 | 2010-01-21 | Saudi Basic Industries Corporation | Catalyst precursor for the production of olefins with an odd number of carbons atoms, process for its preparation and production method for such olefins |
| CN101274290B (en) * | 2007-03-30 | 2011-04-20 | 中国石油天然气股份有限公司 | Late transition metal catalyst and preparation method and application thereof |
| CN102020741A (en) * | 2010-10-20 | 2011-04-20 | 中南民族大学 | Method for preparing linear low-density polyethylene and bifunctional catalyst system |
| CN108467443A (en) * | 2018-03-05 | 2018-08-31 | 象山杰尔德智能科技有限公司 | A kind of new urea case linear low density polyethylene and preparation method thereof |
-
2003
- 2003-11-28 CN CN 200310116909 patent/CN1621423A/en active Pending
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20100016529A1 (en) * | 2005-04-29 | 2010-01-21 | Saudi Basic Industries Corporation | Catalyst precursor for the production of olefins with an odd number of carbons atoms, process for its preparation and production method for such olefins |
| US8304504B2 (en) * | 2005-04-29 | 2012-11-06 | Saudi Basic Industries Corporation | Catalyst precursor for the production of olefins with an odd number of carbons atoms, process for its preparation and production method for such olefins |
| CN100543048C (en) * | 2005-09-22 | 2009-09-23 | 中国科学院化学研究所 | A kind of catalyst system of in-situ copolymerizing linear low-density polyethylene |
| CN101274290B (en) * | 2007-03-30 | 2011-04-20 | 中国石油天然气股份有限公司 | Late transition metal catalyst and preparation method and application thereof |
| CN102020741A (en) * | 2010-10-20 | 2011-04-20 | 中南民族大学 | Method for preparing linear low-density polyethylene and bifunctional catalyst system |
| CN102020741B (en) * | 2010-10-20 | 2012-11-14 | 中南民族大学 | Method for preparing linear low-density polyethylene and bifunctional catalyst system |
| CN108467443A (en) * | 2018-03-05 | 2018-08-31 | 象山杰尔德智能科技有限公司 | A kind of new urea case linear low density polyethylene and preparation method thereof |
| CN108467443B (en) * | 2018-03-05 | 2021-11-09 | 刘俊 | Novel linear low-density polyethylene for urea box and preparation method thereof |
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