JPH0571602B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an industrially advantageous method for producing highly stereoregular poly-1-butene by solution polymerization. Using 1-butene itself as a solvent, 1-butene is polymerized under conditions such that the resulting poly-1-butene is dissolved to form a uniform layer, and then heated to the upper cloud point to form two layers, A method for recovering poly-1-butene with high stereoregularity by separating the lower polymer-rich layer has already been published in Japanese Patent Publications No. 15830-1983 and Japanese Patent Publication No. 15830-1989 and
1757, etc. According to the techniques described in these prior documents, after the polymerization of 1-butene, the above-mentioned 2
Layer separation is performed. The dilute polymer layer forming the upper layer contains a considerable amount of atactic polymer and low molecular weight tactical polymer, and furthermore,
Since it contains a small amount of water used for washing, a separate purification process is performed to recover 1-butene for recycling to the polymerization zone. Moreover, the poly-1-butene yield per unit catalyst is not at a sufficiently satisfactory level, and the stereoregularity index of the poly-1-butene isolated from the concentrated layer is not sufficiently high. As described above, in the conventional method, the post-treatment after polymerization is complicated and costly, and the productivity of poly-1-butene is poor.
It also had many drawbacks and difficulties, including the fact that its quality was not of high quality. The present inventors have conducted research to overcome the drawbacks and difficulties of such conventional methods. As a result, we have discovered an improved method that allows production of high-quality poly-1-butene with a high yield per unit catalyst using simpler and industrially advantageous operations. According to the research of the present inventors, (A) a solid titanium catalyst component containing titanium, magnesium, halogen, and an electron donor as essential components, (B) an organoaluminum compound catalyst component, and (C) Si-O- In the presence of a catalyst formed from an organosilicon compound catalyst component having C bonds or Si-N-C bonds, the poly-
By polymerizing 1-butene under solution polymerization conditions in which 1-butene is dissolved in the liquid phase to form a substantially uniform layer, the drawbacks or difficulties of the conventional methods can be overcome and the above improvements can be achieved. It has been discovered that this can be achieved. Furthermore, when implementing the above improvement method, the produced polymer solution is introduced into a separation zone maintained at a temperature above the upper cloud point to separate into two layers, and poly-1-butene is recovered from the lower layer of the separation zone. However, it has been found that by recycling at least a portion of the upper part of the zone into the polymerization zone, the disadvantages or difficulties of the prior art methods can be more advantageously overcome and further improvements can be achieved. According to the research conducted by the present inventors, the polymer yield per catalyst is extremely high, and the production ratio of stereoregular polymers is also large, so there is no need for a decatalytic operation and amorphous polymers are produced. It has been found that it is also possible to omit or reduce the removal operation of coalescence. Furthermore, it has been found that since most of the unreacted 1-butene can be recycled without any purification operations, post-treatment operations can be simplified and purification costs can be significantly reduced. It is therefore an object of the present invention to provide an improved method for producing poly-1-butene. The above objects and many other objects and advantages of the present invention will become more apparent from the following description. According to the method of the present invention, (A) a solid titanium catalyst component containing titanium, magnesium, halogen, and an electron donor as essential components, (B) an organoaluminum compound catalyst component, and (C) a Si-O-C bond or Si The poly-
The 1-butene is polymerized under conditions such that the 1-butene is dissolved in the liquid phase to form a substantially uniform layer. According to a preferred embodiment, when performing the above polymerization, the produced polymer solution is introduced into a separation zone maintained at a temperature above the upper cloud point to separate into two layers, and the polymer solution is separated from the lower layer of the separation zone into two layers. A method is provided for recovering 1-butene and recycling at least a portion of the upper layer of the zone to a polymerization zone. In the present invention, the term 1-butene polymerization includes not only homopolymerization of 1-butene but also copolymerization, and the term poly-1-butene refers to 1-butene polymerization.
It is sometimes used to include not only butene homopolymers but also copolymers. The highly active solid titanium catalyst component (A) used in the present invention contains magnesium, titanium, halogen, and an electron donor as essential components. Here, the magnesium/titanium (atomic ratio) is preferably about 2 to about 100, more preferably about 4 to about 70,
The halogen/titanium (atomic ratio) is preferably about 4 to about 100, more preferably about 6 to about 40, and the electron donor/titanium (molar ratio) is preferably about 0.2.
Preferably, it ranges from about 10 to about 10, more preferably from about 0.4 to about 6. Also, its specific surface area is
Preferably 3 m ² /g or more, more preferably about 40
m ² /g or more, more preferably 100m ² /g or more
It is 800m ² /g. Such a solid titanium catalyst component (A) usually does not eliminate titanium compounds by simple means such as washing with hexane at room temperature. The X-ray spectrum of the magnesium compound, regardless of the raw material magnesium compound used for catalyst preparation, is either amorphous or, desirably, very amorphous compared to that of a common commercially available magnesium dihalide. It is in a crystallized state. The titanium catalyst component (A) may contain other elements, metals, functional groups, etc. in addition to the above-mentioned essential components as long as the catalyst performance is not significantly deteriorated. Furthermore, it may be diluted with an organic or inorganic diluent. If it contains other elements, metals, diluents, etc.
It may affect the specific surface area and amorphousness, and in that case, it is desirable that when such other components are removed, it shows the specific surface area value as mentioned above and exhibits amorphousness. . To produce the titanium catalyst component (A), a magnesium compound (or magnesium metal), a titanium compound, and a diester or a diester-forming compound (a diester-forming compound) are mixed together with or without other reactants. It is better to adopt a method that brings the material into contact with the material. Its preparation consists of magnesium,
It can be carried out in the same manner as the conventionally known method for preparing a highly active titanium catalyst component containing titanium, halogen, and an electron donor as essential components. For example, JP-A-1986-
No. 108385, No. 50-126590, No. 51-20297, No.
No. 51-28189, No. 51-64586, No. 51-92885,
No. 51-136625, No. 52-87489, No. 52-100596
No. 52-147688, No. 52-104593, No. 53-
No. 2580, No. 53-40093, No. 53-43094, No. 55-
No. 135102, No. 55-135103, No. 56-811, No. 56
It can be manufactured according to the methods disclosed in Japanese Patent No. 11908 and No. 56-18606. Some examples of methods for producing these titanium catalyst components (A) will be briefly described below. (1) A magnesium compound or a chain compound of a magnesium compound and an electron donor,
Pretreated with or without grinding, with or without grinding, with an electron donor and/or a reaction aid such as an organoaluminum compound or a halogen-containing silicon compound, in the presence or absence of a grinding aid, etc. The solid obtained above is reacted with a titanium compound that forms a liquid phase under reaction conditions. However, the above electron donor is used at least once. (2) A liquid magnesium compound that does not have reducing ability and a liquid titanium compound are reacted in the presence of an electron donor to precipitate a solid titanium complex. (3) The material obtained in (2) is further reacted with a titanium compound. (4) The materials obtained in (1) and (2) are further reacted with an electron donor and a titanium compound. (5) A magnesium compound or a complex compound of a magnesium compound and an electron donor,
ground in the presence or absence of grinding aids etc. and in the presence of titanium compounds, pretreated with electron donors and/or reaction aids such as organoaluminum compounds or halogen-containing silicon compounds, or The solid obtained without pretreatment is treated with a halogen or a halogen compound or an aromatic hydrocarbon. However, the above electron donor is used at least once. Among these preparation methods, in catalyst preparation,
Preferably, liquid titanium halide is used, or a halogenated hydrocarbon is used after or during use of a titanium compound. Further, among the titanium catalyst components produced by the above-described method, it is preferable to use a titanium catalyst component that has been subjected to a step in which the magnesium compound is once made into a liquid state and then precipitated as uniform particles in the process of preparing the catalyst component. Electron donors that can be used in the preparation of the titanium catalyst component (A) include alcohols, phenols, aldehydes, ketones, ethers, carboxylic acids, carboxylic anhydrides, carboxylic esters, carboxylic amides, carboxylic halides, Examples include one or more of carbonate esters, amines, alkoxy- or aryloxy-silane compounds, orthoesters, and the like. Examples of electron donors preferably contained in the titanium catalyst component (A) include carboxylic acid esters, carbonate esters, orthoesters, alkoxysilane compounds, and aryloxysilane compounds. Among these, dicarboxylic acid esters are the most preferred. preferable. Examples of esters of dicarboxylic acids include esters of dicarboxylic acids in which two carboxyl groups are bonded to one carbon atom, or esters of dicarboxylic acids in which carboxyl groups are bonded to two adjacent carbon atoms. It is preferable that Examples of dicarboxylic acids in such esters of dicarboxylic acids include malonic acid, substituted malonic acid, succinic acid, substituted succinic acid, maleic acid, substituted maleic acid, fumaric acid, substituted fumaric acid, forming alicyclic acids. Alicyclic dicarboxylic acid with two carboxyl groups bonded to one carbon atom, alicyclic dicarboxylic acid with carboxyl groups bonded to each of two adjacent carbon atoms forming an alicyclic ring, and a carboxyl group in the ortho position. Examples include esters of dicarboxylic acids such as aromatic dicarboxylic acids having carboxyl groups on two adjacent carbon atoms forming a heterocycle. More specific examples of the above dicarboxylic acids include:
Malonic acid; methyl malonic acid, ethyl malonic acid, isopropyl malonic acid, allyl malonic acid,
Substituted malonic acids such as phenylmalonic acid; succinic acid; substituted succinic acids such as methylsuccinic acid, dimethylsuccinic acid, ethylsuccinic acid, methylethylsuccinic acid, itaconic acid; maleic acid; citraconic acid,
Substituted maleic acids such as dimethylmaleic acid; cyclopentane-1,1-dicarboxylic acid, cyclopentane-1,2-dicarboxylic acid, cyclohexane-
1,2-dicarboxylic acid, cyclohexene-1,6
- Alicyclic dicarboxylic acids such as dicarboxylic acid, cyclohexene-3,4-dicarboxylic acid, cyclohexene-4,5-dicarboxylic acid, nadic acid, methylnadic acid, 1-allylcyclohexane-3,4-dicarboxylic acid; phthalic acid, naphthalene-1,
Aromatic dicarboxylic acids such as 2-dicarboxylic acid and naphthalene-2,3-dicarboxylic acid; furan-3,
4-dicarboxylic acid, 4,5-dihydrofuran-
2,3-dicarboxylic acid, benzopyran-3,4-
Dicarboxylic acid, pyrrole-2,3-dicarboxylic acid, pyridine-2,3-dicarboxylic acid, thiophene-3,4-dicarboxylic acid, indole-2,3-dicarboxylic acid
Examples include dicarboxylic acids such as -heterocyclic dicarboxylic acids such as dicarboxylic acids; At least one of the alcohol components of the dicarboxylic acid ester preferably has 2 or more carbon atoms, particularly 3 or more carbon atoms, and both alcohol components preferably have 2 or more carbon atoms, particularly preferably 3 or more carbon atoms. For example, diethyl ester, diisopropyl ester, di-n-propyl ester, di-n-butyl ester, diisobutyl ester, di-tert-butyl ester, diisoamyl ester, di-n-hexyl ester, di-2-ethylhexyl ester,
Examples include di-n-octyl ester, diisodecyl ester, and ethyl n-butyl ester. The magnesium compound used for preparing the solid titanium catalyst component (A) is a magnesium compound with or without reducing ability. Examples of the former include magnesium compounds with magnesium-carbon bonds and magnesium-hydrogen bonds, such as dimethylmagnesium, diethylmagnesium, dipropylmagnesium, dibutylmagnesium, diamylmagnesium, dihexylmagnesium, didecylmagnesium, ethylmagnesium chloride, and propylmagnesium chloride. , butylmagnesium chloride, hexylmagnesium chloride, amylmagnesium chloride, butyl ethoxymagnesium, ethylbutylmagnesium, butylmagnesium hydride, and the like. These magnesium compounds can be used, for example, in the form of a complex compound with an organic aluminum or the like, and may be in a liquid state or a solid state. On the other hand, magnesium compounds without reducing ability include magnesium halides such as magnesium chloride, magnesium bromide, magnesium iodide, and magnesium fluoride;
Alkoxymagnesium halides such as methoxymagnesium chloride, ethoxymagnesium chloride, isopropoxymagnesium chloride, butoxymagnesium chloride, octoxymagnesium chloride;
Allyloxymagnesium halides such as phenoxymagnesium chloride, methylphenoxymagnesium chloride; ethoxymagnesium, isopropoxymagnesium, butoxymagnesium, n-
Alkoxymagnesium such as octoxymagnesium, 2-ethylhexoxymagnesium;
Examples include allyloxymagnesium such as phenoxymagnesium and dimethylphenoxymagnesium; magnesium carboxylates such as magnesium laurate and magnesium stearate. Further, these magnesium compounds without reducing ability may be derived from the above-mentioned magnesium compounds having reducing ability, or may be derived during preparation of the catalyst component. Moreover, the magnesium compound may be a complex compound with other metals, a composite compound, or a mixture with other metal compounds. Furthermore, it may be a mixture of two or more of these compounds. Among these, preferred magnesium compounds are those without reducing ability, and particularly preferred are halogen-containing magnesium compounds, especially magnesium chloride,
These are alkoxymagnesium chloride and allyloxymagnesium chloride. In the present invention, there are various titanium compounds used in the preparation of the titanium catalyst component (A), for example, Ti(OR) _g X _4-g (R is a hydrocarbon group, X is a halogen, 0≦g≦4 ) is suitable. More specifically, _TiCl4 , _TiBr4 ,
Titanium tetrahalides such as _TiI4 ; Ti( _OCH3 )
_Cl3 , Ti _{( OC2H5} ) _Cl3 , Ti ₍ On− _C4H9 ) _Cl3 , Ti
Trihalogenated alkoxytitanium such as (OC ₂ H ₅ ) Br ₃ , Ti (OisoC ₄ H ₉ ) Br ₃ ; T(OCH ₃ ) ₂ Cl ₂ , Ti
(OC ₂ H ₅ ) ₂ Cl ₂ , Ti (On−C ₄ H ₉ ) ₂ Cl ₂ , Ti (OC ₂ H ₅ )
Dihalogenated alkoxy titanium such as _Br2 ; Ti
(OCH ₃ ) ₃ Cl, Ti (OC ₂ H ₅ ) ₃ Cl, Ti (On−
Monohalogenated trialkoxytitanium such as C ₄ H ₉ ) ₃ Cl, Ti(OC ₂ H ₅ ) ₃ Br; Ti(OCH ₃ ) ₄ , Ti
Examples include tetraalkoxytitanium such as ( _OC2H5 ) _{4 and} Ti ₍ On- _C4H9 ) ₄ . Preferred among these are halogen-containing titanium compounds, particularly titanium tetrahalide, and particularly preferred is titanium tetrachloride. These titanium compounds may be used alone or in the form of a mixture. Alternatively, it may be used after being diluted with a hydrocarbon or halogenated hydrocarbon. In preparing the titanium catalyst component (A), a titanium compound, a magnesium compound, an electron donor to be supported, and other electron donors that may be used as necessary, such as alcohol, phenol,
The amount of monocarboxylic acid ester, silicon compound, aluminum compound, etc. to be used varies depending on the preparation method and cannot be absolutely specified, but for example, about 0.1 to about 10 mol of the electron donor to be supported per 1 mol of the magnesium compound, about 10 mol of the electron donor to be supported, and about 10 mol of the electron donor to be supported per mol of the magnesium compound. The proportion can be about 0.05 to about 1000 moles of the compound. In the present invention, the solid titanium catalyst component (A) obtained as described above, the organoaluminum compound catalyst component (B) and the Si-O-C bond or Si-N
A combination catalyst of an organosilicon compound catalyst component (C) having a -C bond is used. The above component (B) includes (i) at least 1 in the molecule;
Organoaluminum compounds with Al-carbon bonds, such as those with the general formula R ¹ mAl(OR ² )nHpXq (where R ¹ and R ² are carbon atoms, usually 1
15 hydrocarbon groups, preferably 1 to 4 hydrocarbon groups, which may be the same or different from each other. X is halogen, m is 0<m≦3, 0≦n<3, p is 0≦p
<3, q is a number such that 0≦q<3, and m+
(ii) an organoaluminum compound represented by the general formula M ¹ AlR ¹ ₄ (where M ¹ is Li, Na, K, and R ¹ is the same as above); Examples include complex alkylated products of aluminum and aluminum. Examples of the organoaluminum compounds that belong to (i) above include the following. General formula R ¹ mAl(OR ² ) _3-n (where R ¹ and R ² are the same as above. m is preferably a number of 1.5≦m≦3), general formula R ¹ mAlX _3-n ( (Here ^{, R 1 is the} _same as above. ≦
m<3. ), general formula R ₁ mAl(OR ₂ )nXq (where R ¹ and R ² are the same as above, X is halogen, 0<m≦3, 0≦n<3, 0≦q<3,
+n+q=3). Examples of aluminum compounds belonging to (i) include the following compounds. Trialkylaluminum such as triethylaluminum, tributylaluminium etc.; trialkenylaluminum such as triisoprenylaluminum; dialkylaluminum alkoxide such as diethylaluminum ethoxide, dibutylaluminum butoxide etc.; ethylaluminum sesquiethoxide, butylaluminum sesquibutoxide etc. In addition to alkylaluminum sesquialkoxides such as alkyl aluminum sesquialkoxides, partially alkoxylated alkylaluminums having an average composition such as R ¹ _2.5 Al (OR ² ) _0.5 ; Dialkyl aluminum halides; Alkylaluminum sesquihalides such as ethyl aluminum sesquichloride, butyl aluminum sesquichloride, ethyl aluminum sesquibromide; Partially alkyl aluminum dihalides such as ethyl aluminum dichloride, propyl aluminum dichloride, butyl aluminum dibromide, etc. other partially hydrogenated alkyls, such as dialkylaluminum hydrides such as diethylaluminum hydride, dibutylaluminum hydride, etc.; alkylaluminum dihydrides such as ethylaluminum dihydride, propylaluminum dihydride, etc. Aluminum; partially alkoxylated and halogenated alkyl aluminums such as ethyl aluminum ethoxy chloride, butyl aluminum butoxy chloride, ethyl aluminum ethoxy bromide. Compounds belonging to (ii) above include LiAl
Examples include (C ₂ H ₅ ) ₄ and LiAl(C ₇ H ₁₅ ) ₄ . Further, as a compound similar to (i), it may be an organic aluminum compound in which two or more aluminum atoms are bonded via an oxygen atom or a nitrogen atom. Examples of such compounds include (C ₂ H ₅ ) ₂ AlOAl
Examples include (C ₂ H ₅ ) ₂ , (C ₄ H ₉ ) ₂ AlOAl(C ₄ H ₉ ) ₂ , (C ₂ H ₅ ) ₂ AlN | C ₂ H ₅ Al(C ₂ H ₅ ) ₂ . Among these, it is particularly preferable to use trialkylaluminum and the above-mentioned alkyl aluminum in which two or more aluminums are combined. Si-O-C or Si- used in the present invention
Organosilicon compound catalyst component (C) having an N-C bond
Examples include alkoxysilane and aryloxysilane. An example of such a compound is the formula RnSi(OR ¹ ) _4-o [where 0≦
n≦3, R is a hydrocarbon group, such as an alkyl group, a cycloalkyl group, an aryl group, an alkenyl group, a haloalkyl group, an aminoalkyl group, or a halogen; R ¹ is a hydrocarbon group, such as an alkyl group, a cycloalkyl group, Aryl group, alkenyl group, alkoxyalkyl group, etc.; provided that n R, (4-
n) OR ¹ groups may be the same or different].
Further, other examples include siloxanes having ^one OR group, silyl esters of carbones, and the like. Still another example is a compound in which two or more silicon atoms are bonded to each other via an oxygen or nitrogen atom. The above organosilicon compounds are converted into compounds with Si-O-C bonds by reacting a compound without Si-O-C bonds with a compound having O-C bonds in advance or by reacting them at the polymerization site. It may also be used. As an example of this, for example, Si-
Examples include the combined use of a halogen-containing silane compound or silicon hydride that does not have an O-C bond, and an alkoxy group-containing aluminum compound, an alkoxy group-containing magnesium compound, other metal alcoholates, alcohols, formic acid esters, ethylene oxide, etc. The organosilicon compound may also contain other metals (eg, aluminum, tin, etc.). More specifically, trimethylmethoxysilane,
Trimethylethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diphenyldimethoxysilane, methylphenyldimethoxysilane, diphenyldiethoxysilane, ethyltrimethoxysilane, methyltrimethoxysilane, vinyltrimethoxysilane, phenyltrimethoxysilane , γ-chloropropyltriethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, vinyltriethoxysilane, butyltriethoxysilane, phenyltriethoxysilane, γ-aminopropyltriethoxysilane, chlortriethoxysilane, ethyltriethoxysilane Isopropoxysilane, vinyltributoxysilane, ethyl silicate, butyl silicate, trimethylphenoxysilane, methyltriallyloxysilane, vinyltris(β-methoxyethoxy)silane, vinyltriacetoxysilane, diethyltetraethoxysilane Examples include siloxane and phenyldiethoxydiethylaminosilane. Among these, particularly preferred are methyltrimethoxysilane, phenyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, vinyltriethoxylane, phenyltriethoxysilane, vinyltributoxysilane, ethyl silicate, Diphenyldimethoxysilane, diphenyldiethoxysilane, methylphenylmethoxysilane, etc. are those represented by the above formula RnSi(OR ¹ ) _4-o , among which n is 0.
or 1. In the present invention, the catalyst components (A), (B) and (C)
The homopolymerization of 1-butene or the copolymerization of 1-butene with a small amount of ethylene and/or other α-olefins is carried out using a catalyst formed from . The polymerization is carried out in a polymerization medium consisting of 1-butene and under conditions such that the resulting poly-1-butene is dissolved in the polymerization medium to form a substantially uniform layer. In the case of copolymerization, the content of 1-butene in poly-1-butene is at least 50 mol%, especially 80% by mole.
It is preferable that the content is mol % or more.
In addition to ethylene, other α-olefins that can be used in copolymerization include propylene, 1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 4-methyl-1
- Examples include pentene. The amount of each catalyst component used in polymerization can be selected as appropriate, but for example, the amount of titanium catalyst component (A) per liquid phase in terms of titanium atoms.
0.001 to 0.1 mmol, more preferably 0.005 to 0.05 mmol, organoaluminum compound catalyst component (B), Al/Ti (atomic ratio) of 1 to 1000, more preferably 10 to 100, organosilicon compound catalyst component (C) The Si/Al (atomic ratio) is preferably in the range of 0.01 to 2, more preferably 0.02 to 1. Molecular weight modifiers such as hydrogen can be used to adjust the molecular weight. The polymerization medium consists essentially of 1-butene, but inert hydrocarbons such as butane, hexane, and, in the case of copolymerization, ethylene and/or other α-olefins to be copolymerized also make up part of the polymerization medium. However, it is preferable to limit the amount of the other liquid medium to 100 parts by volume or less, preferably 10 parts by volume or less, per 100 parts by volume of 1-butene. The lower and upper limits of the temperature at which poly-1-butene dissolves in the polymerization medium to form a uniform layer, that is, the lower and upper cloud points, depend on the composition of the polymerization medium, the composition of poly-1-butene, the hydrogen pressure, and the It also varies slightly depending on the -1-butene concentration. In addition, since the polymerization activity and the formation ratio of stereoregular polymers are also affected by the polymerization temperature, the polymerization temperature should be within the range of the upper cloud point and the lower cloud point and about 40 to about 100℃, especially is about
Preferably, the temperature is selected in the range of 50 to about 80°C.
On the other hand, the polymerization pressure is determined by the polymerization temperature, the necessary amount of hydrogen used, etc., and is usually in the range of about 5 to about 20 kg/cm ² , for example. In order to proceed with the polymerization smoothly and to increase the polymerization efficiency, the concentration of poly-1-butene in the polymerization solution was adjusted to approximately
30 to about 200 g/, especially about 50 to about 150
It is preferable to operate in a manner that maintains the amount within a range of about 100 g/g/g. In addition, in the polymerization system, the stereoregularity index (described in the examples below) is 90% by weight or more, especially 95%.
It is preferred to select catalysts and polymerization conditions such that at least % by weight of poly-1-butene is produced. According to one preferred embodiment of the present invention, the resulting polymer solution obtained as described above is heated to a temperature above the upper cloud point to form two layers, a concentrated polymer liquid layer and a dilute polymer liquid layer. Separation is easy because both layers are easily separated by standing. The temperature of this separation zone should be above the upper cloud point, but if the temperature is too high, it will not only be disadvantageous in terms of heating energy consumption, but also increase the amount of polymerization under conditions different from those in the polymerization zone, which will affect quality. For example, at temperatures above the upper cloud point of 145℃,
Below, the temperature is preferably in the range of about 120° to 140°C. In the catalyst system consisting of the catalyst components (A), (B), and (C) used in the method of the present invention, when the separation zone temperature conditions are maintained at the above-mentioned temperature conditions without decatalyst treatment, 1-butene polymerization occurs. However, the polymerization rate is significantly slower than that in the polymerization zone, and although the stereoregularity index of the poly-1-butene produced tends to decrease, the degree of decrease is lower than that of other polymerization zones. This is far less than when a catalyst system is used, and as a result, there is an advantage that there is substantially no adverse effect on the quality of the poly-1-butene obtained. The influence on quality due to the polymerization occurring in this separation zone is such that the residence time of the resulting polymer solution system in the separation zone is shorter than that in the polymerization zone, e.g., about 1/3 or less of the residence time in the polymerization zone, more preferably. It can be further reduced by reducing the retention time to about 1/5 or less. Since 1-butene and the like can be easily recovered from the concentrated liquid layer of the polymer in the lower part of the separation zone by, for example, flashing, the pressure can be increased again and recycled to the polymerization system. The polymer remaining after the above flashing operation is fed as it is to a vent type extruder or an extruder equipped with a degassing device as described in Japanese Patent Publication No. 52-50234 to continue degassing and melt extrusion. Therefore, it is easy to make pellets. In this operation, water is used to inactivate the catalyst and promote degassing.
Small amounts of alcohol, steam, etc. can be used. Further, stabilizers, antioxidants, halogen scavengers, solvents, nucleating agents, and other various additives can be blended. On the other hand, a part or all of the dilute liquid layer in the upper layer of the separation zone can be recycled as it is to the polymerization system and reused. The catalyst system used in the present invention has the advantage that such circulation does not have any adverse effect on the polymerization system. Furthermore, due to the high proportion of stereoregular polymers produced, such circulation does not undesirably significantly reduce the content of stereoregular polymers in the product. There is also. Of course, a part of the dilute liquid layer may be extracted from the system for the purpose of purging low molecular weight polymers, etc., and only the monomer components may be recovered. However, for industrially advantageous implementation, 50% by weight of the dilute liquid layer must be
It is preferable that the above amount, particularly 80% by weight or more, be recycled to the polymerization zone. According to the present invention, the process is simple, the polymer yield per catalyst is large, and the production ratio of stereoregular polymers is also high, so that high-quality poly-1-butene can be produced at low cost. Next, examples will be shown. Example 1 <Preparation of titanium catalyst component (A)> Anhydrous magnesium chloride 4.76 g (50 mmol), decane 25 ml and 2-ethylhexyl alcohol
After heating 23.4 ml (150 mmol) at 130°C for 2 hours to form a homogeneous solution, 1.11 g (7.5 mmol) of phthalic anhydride was added to this solution, and the mixture was further stirred and mixed at 130°C for 1 hour. Phthalic anhydride is dissolved in the homogeneous solution. After the homogeneous solution thus obtained was cooled to room temperature, the entire amount was added dropwise over 1 hour to 200 ml (1.8 mol) of titanium tetrachloride maintained at -20°C. After charging, the temperature of this mixture was raised to 110℃ over 4 hours, and when it reached 110℃, 2.68ml (12.5mmol) of diisobutyl phthalate was added.
is added and the mixture is kept under stirring at the same temperature for 2 hours. After the completion of the 2-hour reaction, the solid portion was collected by heating, and after resuspending this solid portion in 200 ml of TiCl ₄ , the heating reaction was performed again at 110° C. for 2 hours.
After the reaction is complete, collect the solid part by heating again.
Wash thoroughly with decane and hexane at 110°C until no free titanium compound is detected in the washing solution. The titanium catalyst component (A) synthesized by the above production method is stored as a hexane slurry, and a portion of this is dried for the purpose of examining the catalyst composition. The composition of the titanium catalyst component (A) obtained in this way was 3.1% by weight of titanium, 56.0% by weight of chlorine, and magnesium.
17.0 wt% and diisobutyl phthalate 20.9 wt%. <Polymerization> In the continuous method shown in Figure 1, 1-butene was added at 33 mmol per hour from tube 5, triethylaluminum was added at 35 mmol per hour from tube 4, and vinyltriethoxysilane was added at 3.5 mmol per hour from tube 3. ,
Titanium catalyst component (A) 0.7 mmol per hour from tube 2
were added to the polymerization vessel 6 at a rate of . Hydrogen was added through tube 1, and the hydrogen partial pressure in polymerization vessel 6 was maintained at 0.6 atm. The liquid volume in the polymerization vessel 6 was maintained at 100, and the temperature was maintained at 60°C. In order to maintain a constant liquid volume in the polymerization vessel, the polymerization liquid was extracted, heated to 130°C by a heat exchanger 7, and then introduced into a separation tank 8. While maintaining the liquid level of the separation tank 8 at 10° C., the concentrated liquid was extracted from the lower part, and the dilute liquid was extracted from the upper part, and the temperature was lowered to 60° C. by the heat exchanger 9, and then introduced into the polymerization vessel 6. The circulation rate of 1-butene from the separation tank 8 to the polymerization vessel 6 is 67 per hour, the average residence time in the polymerization vessel 6 is 1 hour, and the average residence time in the separation vessel 8 is 0.1.
It was time. The concentrated liquid extracted from the lower part of the separation tank 8 contained about 50% by weight of 1-butene. 10 kg of poly-1-butene was obtained per hour. The polymerization results and physical property measurement results are shown in Table 1. <Physical property measurement method> Polymerization activity: Polymer yield per 1 mmol of titanium. MI: Measured at 190℃ and a load of 10Kg. Stereoregularity index (II): After dissolving 1g of poly-1-butene in 100ml of n-decane, it was cooled to 0°C and left at 0°C for 24 hours to precipitate highly stereoregular components and remove the insoluble part. The weight % of was defined as II. Yield point stress: After pelletizing, a press sheet with a pressure of 1 mm was made, and 10 days later, a test piece was punched out and measured at 23°C. Critical creep stress: after pelletizing, inner diameter 25mm
A pipe with a wall thickness of 2 mm was made, and the stress that it withstood at 80°C for 24 hours was defined as the critical creep stress. Comparative Example 1 <Preparation of titanium catalyst component> 20 g of anhydrous magnesium chloride, ethyl benzoate
5.0ml and methylpolysiloxane (viscosity 100cs)
3.0ml in a nitrogen atmosphere with a 2.8Kg stainless steel ball with a diameter of 15mm, an internal volume of 800ml, and an inner diameter of 100mm.
The sample was placed in a stainless steel ball mill container and exposed to an impact acceleration of 7G for 24 hours. 20 g of the obtained co-pulverized material was suspended in 200 ml of titanium tetrachloride, and
After contacting with stirring at ℃ for 2 hours, the solid part was filtered through a glass filter while hot, thoroughly washed with produced hexane until no free titanium tetrachloride was detected in the washing liquid, and then dried under reduced pressure. Obtain a titanium composite. The ingredients are titanium 1.9% by weight and chlorine 65% in terms of atoms.
wt%, magnesium 23wt%, ethyl benzoate
Contains 7.7% by weight. <Polymerization> 100m of triethylaluminum per hour
mol, 33 m of P-methyl toluate per hour
Polymerization was carried out in the same manner as in Example 1 except that 2 mmol of the titanium catalyst component was added per hour, and the results are shown in Table 1.
It was shown to. These results show that the present invention provides poly-1-butene with high polymerization activity and excellent II, yield point stress, and critical creep stress. Examples 2 to 5 Polymerization was carried out in the same manner as in Example 1, except that the titanium catalyst component (A) prepared in Example 1 was used and the organosilicon compound was changed to those listed in Table 1, and the results are shown in Table 1. Indicated.

[Table] Examples 6 to 11 The titanium catalyst component (A) prepared in Example 1 was used, and the same procedure as in Example 1 was performed except that the amount of vinyltriethoxysilane added during polymerization or the hydrogen partial pressure was changed. Polymerization was carried out and the results are shown in Table 2.

【table】

【table】 [Brief explanation of the drawing]

FIG. 1 is a drawing showing one embodiment of the present invention. FIG. 2 is a flowchart showing a method for preparing a catalyst used in the method of the present invention.

Claims (1)

[Scope of Claims] 1 (A) a solid titanium catalyst component containing titanium, magnesium, halogen, and an electron donor as essential components, (B) an organoaluminum compound catalyst component, and (C) a Si-O-C bond. In the presence of a catalyst formed from an organosilicon compound catalyst component having
1-Butene is polymerized under conditions in which 1-butene is dissolved in the liquid phase to form a substantially uniform layer, and the resulting polymer solution is directly heated to a temperature above the upper cloud point without separating the catalyst components. The poly-1
- A process for producing poly-1-butene, characterized in that the butene is recovered and at least part of the upper layer of the zone is recycled directly to the polymerization zone.