JPH04366108A - Preparation of styrene polymer and catalyst therefor - Google Patents

Abstract

PURPOSE:To produce syndiotactic polystyrene by the polymerization of styrene monomer without using aluminoxane, which is expensive and should be used in a large amount. CONSTITUTION:Syndiotactic polystyrene is produced using a catalyst which comprises a transition metal compound, e.g. (pentamethylcyclopentadienyl) trimethyltitanium, and an oragnoboron compound, e.g. tri(pentafluorophenyl) boron, and which may further comprise an alkylating agent, e.g. triisobutylaluminum.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to a method for producing a styrenic polymer and a catalyst used in the method, and more particularly, the present invention relates to a method for producing a styrenic polymer and a catalyst used in the method. The present invention relates to an efficient production method and a catalyst used in the method.

0002

[Prior Art] The research group of the present inventors has recently developed a styrenic monomer with a syndiotactic structure by polymerizing a styrenic monomer using a catalyst mainly consisting of a transition metal compound, particularly a Ti compound, and an alkylaluminoxane. It was shown that a polymer could be obtained (JP-A-62-1
No. 87708, No. 63-179906, No. 63-24
1009, etc.).

[0003] Methylaluminoxane, which is particularly suitable as alkylaluminoxane, is usually obtained by reacting trimethylaluminum with water, but since the reaction is violent,
There is a problem in that it is difficult to manufacture. In addition to the fact that the raw material trimethylaluminum is expensive,
When used as a catalyst, a large excess amount of methylaluminoxane is required compared to the amount of transition metal. Therefore, there was a drawback that the catalyst cost was extremely high.

[0004] In recent years, it has been discovered by R. Taube [J. Organome
t. Chem. C9-C11, 347 (1988
)], H. Turner [J. Am. Chem
．． Soc. 111, 2728 (1989)],
R. F. Jordan [Organomet. 8
, 2892 (1989)], but for styrenic monomers, no studies have yet been conducted on polymerization catalysts that do not contain aluminoxane. Furthermore, unlike α-olefins, styrene monomers have a problem in that when cationic species are present, a large amount of atactic polymer is produced.

[0005]

[Problems to be Solved by the Invention] Therefore, the present inventors have attempted to efficiently produce a styrenic polymer having a syndiotactic structure by polymerizing styrenic monomers without using aluminoxane, which is expensive and used in large quantities. We have conducted intensive research to develop a catalyst that can produce styrenic polymers and a method for producing styrenic polymers using the catalyst.

[0006]

[Means for solving the problem] As a result, the activity can be significantly improved by using a combination of a specific transition metal compound and a specific organic boron compound, as well as an alkylating agent. discovered that it is possible to efficiently produce a styrenic polymer having the desired syndiotactic structure. The present invention was completed based on this knowledge.

That is, the present invention provides (A) a transition metal compound and (B) a general formula (I) BR1 R2 R3 ... (I) [wherein R1, R2 and R3 each have 1 to 20 carbon atoms] represents an alkyl group or an aryl group having 6 to 20 carbon atoms. ], and (A) a transition metal compound, (B) an organoboron compound of general formula (I), and (C
) an alkylating agent. The present invention also provides a method for producing a styrenic polymer, characterized in that the above catalyst is used in polymerizing styrene and/or a styrene derivative.

The catalyst of the present invention comprises the above-mentioned components (A) and (B), or the components (A), (B) and (C). Here, component (A) is a transition metal compound, and various compounds can be used, but compounds of metals of groups 3 to 6 of the periodic table and compounds of lanthanum metals are usually mentioned. Among these, compounds of Group 4 metals (titanium, zirconium, hafnium, vanadium, etc.) are preferred. There are various titanium compounds, for example, general formula (II) TiR4 a R5 b R6 c R7 4-(a+
b+c) ...(II) or general formula (III) TiR4 d R5 e R6 3-(d+e)
...(III) [wherein, R4, R
5, R6 and R7 are each hydrogen atom, carbon number 1
~20 alkyl group, alkoxy group having 1 to 20 carbon atoms,
Aryl group having 6 to 20 carbon atoms, alkylaryl group, arylalkyl group, acyloxy group having 1 to 20 carbon atoms,
Indicates a cyclopentadienyl group, a substituted cyclopentadienyl group, an indenyl group, or a halogen atom. a, b,
c each represents an integer from 0 to 4, and d and e each represent 0
Indicates an integer between ~3. ] is at least one compound selected from the group consisting of titanium compounds and titanium chelate compounds.

R in this general formula (II) or (III)
4, R5, R6 and R7 are each a hydrogen atom,
Alkyl groups having 1 to 20 carbon atoms (specifically methyl group, ethyl group, propyl group, butyl group, amyl group, isoamyl group, isobutyl group, octyl group, 2-ethylhexyl group, etc.), 1 to 20 carbon atoms Alkoxy group (specifically methoxy group, ethoxy group, propoxy group, butoxy group, amyloxy group, hexyloxy group, 2-ethylhexyloxy group, etc.), aryl group having 6 to 20 carbon atoms, alkylaryl group, arylalkyl group (specifically phenyl group, tolyl group, xylyl group, benzyl group, etc.), acyloxy group having 1 to 20 carbon atoms (specifically heptadecylcarbonyloxy group, etc.), cyclopentadienyl group,
Substituted cyclopentadienyl group (specifically methylcyclopentadienyl group; 1,2,3,4-tetramethylcyclopentadienyl group; 1,3-dimethylcyclopentadienyl group; pentamethylcyclopentadienyl group) enyl group, etc.)
, an indenyl group or a halogen atom (specifically chlorine, bromine, iodine, and fluorine). These R4, R5,
R6 and R7 may be the same or different. Further, a, b, and c each represent an integer of 0 to 4, and d and e each represent an integer of 0 to 3.

A more suitable titanium compound has the general formula (
IV) TiRXYZ...(IV) [In the formula,
R represents a cyclopentadienyl group, substituted cyclopentadienyl group, indenyl group, substituted indenyl group, fluorenyl group, etc., and X, Y and Z each independently represent a hydrogen atom,
Alkyl group having 1 to 12 carbon atoms, alkoxy group having 1 to 12 carbon atoms, aryl group having 6 to 20 carbon atoms, 6 to 20 carbon atoms
represents an aryloxy group, an arylalkyl group having 6 to 20 carbon atoms, or a halogen atom. ] There is a titanium compound represented by The substituted cyclopentadienyl group represented by R in this formula is, for example, a cyclopentadienyl group substituted with one or more alkyl groups having 1 to 6 carbon atoms, specifically a methylcyclopentadienyl group; ,3-dimethylcyclopentadienyl group; 1,2,4-trimethylcyclopentadienyl group; 1,2,3,4-tetramethylcyclopentadienyl group; trimethylsilylcyclopentadienyl group; 1,3- These include di(trimethylsilyl)cyclopentadienyl group; tert-butylcyclopentadienyl group; 1,3-di(tert-butyl)cyclopentadienyl group; pentamethylcyclopentadienyl group. In addition, X, Y and Z each independently represent a hydrogen atom, an alkyl group having 1 to 12 carbon atoms (specifically, a methyl group, ethyl group, propyl group, n-butyl group, isobutyl group, amyl group, isoamyl group, octyl group, 2-ethylhexyl group, etc.), alkoxy groups having 1 to 12 carbon atoms (specifically methoxy group, ethoxy group, propoxy group, butoxy group, amyloxy group, hexyloxy group, octyloxy group, 2-ethylhexyl group, etc.),
-ethylhexyloxy group, etc.), aryl group with 6 to 20 carbon atoms (specifically, phenyl group, naphthyl group, etc.), aryloxy group with 6 to 20 carbon atoms (specifically, phenoxy group, etc.), 6 to 20 carbon atoms ~20 arylalkyl groups (specifically benzyl groups) or halogen atoms (specifically chlorine,
bromine, iodine or fluorine).

Specific examples of the titanium compound represented by the general formula (IV) include cyclopentadienyltrimethyltitanium; cyclopentadienyltriethyltitanium; cyclopentadienyltripropyltitanium; cyclopentadienyltributyltitanium ; Methylcyclopentadienyltrimethyltitanium; 1,2-dimethylcyclopentadienyltrimethyltitanium; 1,2,4-trimethylcyclopentadienyltrimethyltitanium; 1,2,
3,4-tetramethylcyclopentadienyltrimethyltitanium; pentamethylcyclopentadienyltrimethyltitanium; pentamethylcyclopentadienyltriethyltitanium; pentamethylcyclopentadienyltripropyltitanium; pentamethylcyclopentadienyltributyltitanium; Cyclopentadienyl methyl titanium dichloride; Cyclopentadienyl ethyl titanium dichloride; Pentamethyl cyclopentadienyl methyl titanium dichloride; Pentamethyl cyclopentadienyl ethyl titanium dichloride; Cyclopentadienyl dimethyl titanium monochloride; Cyclopentadienyl diethyl Titanium monochloride; cyclopentadienyl titanium trimethoxide; cyclopentadienyl titanium triethoxide; cyclopentadienyl titanium tripropoxide; cyclopentadienyl titanium triphenoxide; pentamethylcyclopentadienyl titanium trimethoxide; Pentamethylcyclopentadienyl titanium triethoxide; Pentamethylcyclopentadienyl titanium tripropoxide; Pentamethylcyclopentadienyl titanium tributoxide; Pentamethylcyclopentadienyl titanium triphenoxide; Cyclopentadienyl titanium trichloride; Pentamethyl cyclopentadienyl titanium trichloride; Cyclopentadienyl methoxy titanium dichloride; Cyclopentadienyl dimethoxy titanium chloride; Pentamethyl cyclopentadienyl methoxy titanium dichloride; Cyclopentadienyl tribenzyl titanium; Pentamethyl cyclopentadienyl Examples include methyldiethoxytitanium; indenyltitanium trichloride; indenyltitanium trimethoxide; indenyltitanium triethoxide; indenyltrimethyltitanium; indenyltribenzyltitanium. Among these titanium compounds, compounds containing no halogen atoms are preferred, and titanium compounds having one π-electron system ligand as described above are particularly preferred. Furthermore, as a titanium compound, general formula (V)

0012

[Chemical formula 1]

[In the formula, R8 and R9 each represent a halogen atom, an alkoxy group having 1 to 20 carbon atoms, or an acyloxy group, and k represents 2 to 20. ] You may use the condensed titanium compound represented by this. Further, the titanium compound may be a complex formed with an ester, an ether, or the like. The trivalent titanium compound represented by the above general formula (V) typically includes titanium trihalides such as titanium trichloride, and cyclopentadienyl titanium compounds such as cyclopentadienyl titanium dichloride. Examples include those obtained by reducing titanium compounds. These trivalent titanium compounds may be complexed with esters, ethers, etc. Zirconium compounds as transition metal compounds include tetrabenzylzirconium, zirconium tetraethoxide, zirconium tetrabutoxide, bisindenylzirconium dichloride, triisopropoxyzirconium chloride, zirconiumbenzyldichloride, tributoxyzirconium chloride, and pentamethylcyclopentadichloride. Hafnium compounds include tetrabenzyl hafnium, hafnium tetraethoxide, hafnium tetrabutoxide, pentamethylcyclopentadienyl trimethyl hafnium, and vanadium compounds. , vanadyl bisacetylacetonate, vanadyl triacetylacetonate, triethoxyvanadyl, tripropoxyvanadyl, etc. Among these transition metal compounds, titanium compounds are particularly preferred.

Other transition metal compounds as component (A) include transition metal compounds having two ligands having conjugated π electrons, such as those of the general formula (VI) M1 R10R11R12R13 (VI
) [In the formula, M1 represents titanium, zirconium or hafnium, R10 and R11 each represent a cyclopentadienyl group, substituted cyclopentadienyl group, indenyl group or fluorenyl group, R12 and R13
each represents hydrogen, halogen, a hydrocarbon group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an amino group or a thioalkoxy group having 1 to 20 carbon atoms. However, R
10 and R11 are hydrocarbon groups having 1 to 5 carbon atoms, 1 carbon number
It may be crosslinked by an alkylsilyl group having 1 to 20 carbon atoms and 1 to 5 silicon atoms, or a germanium-containing hydrocarbon group having 1 to 20 carbon atoms and 1 to 5 germanium atoms. ] There is at least one compound selected from the group consisting of transition metal compounds represented by the following.

R10 and R11 in this general formula (VI) are cyclopentadienyl groups, substituted cyclopentadienyl groups (specifically, methylcyclopentadienyl groups; 1,3-
Dimethylcyclopentadienyl group; 1,2,4-trimethylcyclopentadienyl group; 1,2,3,4-tetramethylcyclopentadienyl group; Pentamethylcyclopentadienyl group; Trimethylsilylcyclopentadienyl group ;1,3-di(trimethylsilyl)cyclopentadienyl group;1,2,4-tri(trimethylsilyl)cyclopentadienyl group;tert-butylcyclopentadienyl group;1,3-di(tert-butyl) Cyclopentadienyl group; 1,2,4-tri(tert-butyl)cyclopentadienyl group, etc.), indenyl group,
Substituted indenyl group (specifically methylindenyl group; dimethylindenyl group; trimethylindenyl group, etc.),
It represents a fluorenyl group or a substituted fluorenyl group (e.g. methylfluorenyl group), R10 and R11 may be the same or different, and R10 and R11 have 1 to 5 carbon atoms.
an alkylidene group (specifically, a methine group, ethylidene group, propylidene group, dimethylcarbyl group, etc.) or an alkylsilyl group having 1 to 20 carbon atoms and 1 to 5 silicon atoms (specifically, a dimethylsilyl group, It may have a crosslinked structure with diethylsilyl group, dibenzylsilyl group, etc.). On the other hand, R12 and R13 are as described above, but more specifically, each independently represents hydrogen, an alkyl group having 1 to 20 carbon atoms (methyl group, ethyl group, propyl group, n-butyl group, isobutyl group, amyl group, isoamyl group, octyl group, 2-ethylhexyl group, etc.), aryl group having 6 to 20 carbon atoms (specifically, phenyl group, naphthyl group, etc.),
An arylalkyl group having 7 to 20 carbon atoms (specifically, benzyl group, etc.), an alkoxy group having 1 to 20 carbon atoms (specifically, methoxy group, ethoxy group, propoxy group, butoxy group, amyloxy group, hexyl group, etc.) (oxy group, octyloxy group, 2-ethylhexyloxy group, etc.), carbon number 6 or more
20 aryloxy groups (specifically, phenoxy groups, etc.), as well as amino groups and thioalkoxy groups having 1 to 20 carbon atoms.

Specific examples of such transition metal compounds represented by the general formula (VI) include biscyclopentadienyltitanium dimethyl; biscyclopentadienyltitanium diethyl; biscyclopentadienyltitanium dipropyl; Pentadienyl titanium dibutyl; bis(methylcyclopentadienyl) titanium dimethyl; bis(tert-butylcyclopentadienyl) titanium dimethyl; bis(1,3-dimethylcyclopentadienyl) titanium dimethyl; bis(1,3 -ditert-butylcyclopentadienyl)titaniumdimethyl; bis(1,2,
4-trimethylcyclopentadienyl) titanium dimethyl; bis(1,2,3,4-tetramethylcyclopentadienyl) titanium dimethyl; biscyclopentadienyl titanium dimethyl; bis(trimethylsilylcyclopentadienyl) titanium dimethyl; Bis(1,3-di(trimethylsilyl)cyclopentadienyl)titanium dimethyl; bis(1,2,4-tri((trimethylsilyl)cyclopentadienyl)titanium dimethyl; bisindenyltitanium dimethyl; bisfluorenyl titanium Dimethyl; methylenebiscyclopentadienyltitaniumdimethyl; ethylidenebiscyclopentadienyltitaniumdimethyl; methylenebis(2,3,4,5-tetramethylcyclopentadienyl)titaniumdimethyl; ethylidenebis(2,3,4,5
-tetramethylcyclopentadienyl)titanium dimethyl; dimethylsilylbis(2,3,4,5-tetramethylcyclopentadienyl)titaniumdimethyl; methylenebisindenyltitaniumdimethyl; ethylidenebisindenyltitaniumdimethyl; dimethylsilylbis Indenyl titanium dimethyl; methylene bisfluorenyl titanium dimethyl;
Ethylidene bisfluorenyl titanium dimethyl; dimethylsilylbisfluorenyl titanium dimethyl; methylene (tert-butylcyclopentadienyl) (cyclopentadienyl) titanium dimethyl; methylene (cyclopentadienyl) (indenyl) titanium dimethyl; ethylidene (cyclopentadienyl) (indenyl) titanium dimethyl; dimethylsilyl (cyclopentadienyl) (indenyl) titanium dimethyl; methylene (cyclopentadienyl) (fluorenyl) titanium dimethyl; ethylidene (cyclopentadienyl) (fluorenyl) titanium Dimethyl; dimethylsilyl (cyclopentadienyl) (fluorenyl) titanium dimethyl; methylene (indenyl) (fluorenyl) titanium dimethyl; ethylidene (indenyl)
(fluorenyl) titanium dimethyl; dimethylsilyl (indenyl) (fluorenyl) titanium dimethyl; biscyclopentadienyl titanium dibenzyl; bis(tert-butylcyclopentadienyl) titanium dibenzyl; bis(methylcyclopentadienyl) titanium dibenzyl Benzyl;
Bis(1,3-dimethylcyclopentadienyl)titanium dibenzyl; bis(1,2,4-trimethylcyclopentadienyl)titanium dibenzyl; bis(1,2,3,4
-tetramethylcyclopentadienyl) titanium dibenzyl; bispentamethylcyclopentadienyl titanium dibenzyl; bis(trimethylsilylcyclopentadienyl) titanium dibenzyl; bis(1,3-di-(trimethylsilyl)cyclopentadienyl) ) titanium dibenzyl; bis(1,2,4-tri(trimethylsilyl)cyclopentadienyl) titanium dibenzyl; bisindenyl titanium dibenzyl; bisfluorenyl titanium dibenzyl; methylenebiscyclopentadienyl titanium dibenzyl ; ethylidene biscyclopentadienyl titanium dibenzyl; methylene bis(2,3,4,5-tetramethylcyclopentadienyl) titanium dibenzyl; ethylidene bis(2,
3,4,5-tetramethylcyclopentadienyl) titanium dibenzyl; dimethylsilylbis(2,3,4,5-
Tetramethylcyclopentadienyl) titanium dibenzyl; methylene bisindenyl titanium dibenzyl; ethylidene bisindenyl titanium dibenzyl; dimethylsilyl bisindenyl titanium dibenzyl; methylene bisfluorenyl titanium dibenzyl; ethylidene bisfluorenyl Titanium dibenzyl; dimethylsilylbisfluorenyl titanium dibenzyl; methylene (cyclopentadienyl) (indenyl) titanium dibenzyl; ethylidene (cyclopentadienyl) (indenyl) titanium dibenzyl; dimethylsilyl (cyclopentadienyl) (indenyl) titanium dibenzyl; methylene (cyclopentadienyl) (fluorenyl) titanium dibenzyl; ethylidene (cyclopentadienyl) (fluorenyl) titanium dibenzyl; dimethylsilyl (cyclopentadienyl) (fluorenyl) titanium dibenzyl; Methylene (indenyl) (fluorenyl) titanium dibenzyl; ethylidene (indenyl)
(fluorenyl) titanium dibenzyl; dimethylsilyl (
(indenyl) (fluorenyl) titanium dibenzyl; biscyclopentadienyl titanium dimethoxide; biscyclopentadienyl titanium diethoxide; biscyclopentadienyl titanium dipropoxide; biscyclopentadienyl titanium dibutoxide; Cyclopentadienyl titanium diphenoxide; bis(methylcyclopentadienyl) titanium dimethoxide; bis(1,3-dimethylcyclopentadienyl) titanium dimethoxide;
Bis(1,2,4-trimethylcyclopentadienyl)
Titanium dimethoxide; bis(1,2,3,4-teiramethylcyclopentadienyl) titanium dimethoxide;
Bispentamethylcyclopentadienyl titanium dimethoxide; bis(trimethylsilylcyclopentadienyl) titanium dimethoxide; bis(1,3-di(trimethylsilyl)cyclopentadienyl) titanium dimethoxide; bis(1,2 ,4-tri(trimethylsilyl)cyclopentadienyl) titanium dimethoxide; bisindenyl titanium dimethoxide; bisfluorenyl titanium dimethoxide; methylene biscyclopentadienyl titanium dimethoxide; ethylidene biscyclopentadi enyl titanium dimethoxide; methylene bis(2,3,4,
5-tetramethylcyclopentadienyl) titanium dimethoxide; ethylidene bis(2,3,4,5-tetramethylcyclopentadienyl) titanium dimethoxide; dimethylsilylbis(2,3,4,5-tetra methylcyclopentadienyl) titanium dimethoxide; methylenebisindenyltitanium dimethoxide; methylenebis(methylindenyl)titanium dimethoxide; ethylidenebisindenyltitanium dimethoxide; dimethylsilylbisindenyltitanium dimethoxide; Methylene bisfluorenyl titanium dimethoxide; methylene bis(methylfluorenyl) titanium dimethoxide; ethylidene bisfluorenyl titanium dimethoxide; dimethylsilyl bisfluorenyl titanium dimethoxide; methylene (cyclopentadienyl) (indenyl) titanium dimethoxide; ethylidene (cyclopentadienyl) (indenyl) titanium dimethoxide; dimethylsilyl (cyclopentadienyl) (indenyl) titanium dimethoxide; methylene (cyclopentadienyl) (fluorenyl) titanium Dimethoxide; ethylidene (cyclopentadienyl) (fluorenyl) titanium dimethoxide; dimethylsilyl (cyclopentadienyl) (fluorenyl) titanium dimethoxide; methylene (indenyl) (fluorenyl) titanium dimethoxide; ethylidene (indenyl) )
(Fluorenyl) titanium dimethoxide; dimethylsilyl (indenyl) (fluorenyl) titanium dimethoxide, and the like.

Further, examples of zirconium compounds include ethylidene biscyclopentadienyl zirconium dimethoxide, dimethylsilylbiscyclopentadienyl zirconium dimethoxide, and further examples of hafnium compounds include ethylidene biscyclopentadienyl hafnium dimethoxide. Methoxide, dimethylsilylbiscyclopentadienyl hafnium dimethoxide, etc. Among these, titanium compounds are particularly preferred. Furthermore, in addition to these combinations, 2,2'-thiobis(4-methyl-6-
t-butylphenyl) titanium diisopropoxide; 2,
It may also be a bidentate complex such as 2'-thiobis(4-methyl-6-t-butylphenyl)titanium dimethoxide.

On the other hand, component (B) of the catalyst of the present invention has the general formula (I) BR1 R2 R3 ... (I) [wherein R1
, R2 and R3 are an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms. ] Any boron compound can be used as long as it is a boron compound in which an alkyl group or an aryl group is bonded as a substituent to boron. Here, the alkyl group includes a halogen-substituted alkyl group, and the aryl group also includes a halogen-substituted aryl group and an alkyl-substituted aryl group.

R1, R2 and R3 in this general formula (I) each represent an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, and specific examples include a methyl group, an ethyl group, Propyl group, butyl group, amyl group,
These include alkyl groups such as isoamyl group, isobutyl group, octyl group, and 2-ethylhexyl group, or aryl groups such as phenyl group, fluorophenyl group, tolyl group, xylyl group, and benzyl group. Note that R1 to R3 may be the same or different from each other.

Specific examples of the organic boron compound represented by the general formula (I) include triphenylboron, tri(pentafluorophenyl)boron, tri(2,3,
4,5-tetrafluorophenyl)boron, tri(2,
4,5,6-tetrafluorophenyl)boron, tri(
2,3,5,6-tetrafluorophenyl)boron, tri(2,4,6-trifluorophenyl)boron, tri(3,4,5-trifluorophenyl)boron, tri(
2,3,4-trifluorophenyl)boron, tri(3
,4,6-trifluorophenyl)boron,tri(2,
3-difluorophenyl)boron, tri(2,6-difluorophenyl)boron, tri(3,5-difluorophenyl)boron, tri(2,5-difluorophenyl)
Boron, tri(2-fluorophenyl)boron, tri(
3-fluorophenyl)boron, tri(4-fluorophenyl)boron, tri[3,5-di(trifluoromethyl)phenyl]boron, tri[(4-fluoromethyl)
phenyl]boron, diethylboron, diethylbutylboron, trimethylboron, triethylboron, tri(n
-butyl)boron, tri(trifluoromethyl)boron, tri(pentafluoroethyl)boron, tri(nonafluorobutyl)boron, tri(2,4,6-trifluorophenyl)boron, tri(3,5-difluoro phenyl)boron, di(pentafluorophenyl)fluoroboron, diphenylfluoroboron, di(pentafluorophenyl)chloroboron, dimethylfluoroboron, diethylfluoroboron, di(n-butyl)fluoroboron, (pentafluorophenyl)difluoroboron , phenylfluoroboron, (pentafluorophenyl)dichloroboron, methyldifluoroboron, ethyldifluoroboron, (n-butyl)difluoroboron, and the like. Among these, tri(pentafluorophenyl)boron is particularly preferred.

The catalyst of the present invention may further contain (C
) using an alkylating agent as a component. Here, the alkylating agent is an alkyl group-containing compound, and there are various types, for example, general formula (VII) R14p Al (
OR15) q X'3-p-q...
(VII) [In the formula, R14 and R15 each represent an alkyl group having 1 to 8 carbon atoms, preferably 1 to 4 carbon atoms, and
indicates hydrogen or halogen. Also, p is 0<p≦3
, preferably 2 or 3, most preferably 3,
q is 0≦q<3, preferably 0 or 1. ] Alkyl group-containing aluminum compounds represented by the general formula (VIII) R142 Mg...(
VIII) [In the formula, R14 is the same as above. An alkyl group-containing magnesium compound represented by the formula (IX) R142 Zn...(IX) [wherein R14 is the same as above]. Examples include alkyl group-containing zinc compounds represented by the following. Among these alkyl group-containing compounds, alkyl group-containing aluminum compounds, particularly trialkyl aluminum and dialkyl aluminum compounds, are preferred. Specifically, trimethylaluminum, triethylaluminum, tri-n-propylaluminum, triisopropylaluminum, tri-n
-butylaluminum, triisobutylaluminum,
Trialkylaluminum such as tri-t-butylaluminum, dialkyl such as dimethylaluminum chloride, diethylaluminum chloride, di-n-propylaluminum chloride, diisopropylaluminum chloride, di-n-butylaluminum chloride, diisobutylaluminum chloride, di-t-butylaluminum chloride, etc. Dialkyl aluminum alkoxides such as aluminum halide, dimethyl aluminum methoxide, dimethyl aluminum ethoxide, dimethyl aluminum hydride, diethyl aluminum hydride,
Examples include dialkyl aluminum hydride such as diisobutyl aluminum hydride. Furthermore,
Dimethylmagnesium, diethylmagnesium, di-n-
Examples include dialkylmagnesiums such as propylmagnesium and diisopropylmagnesium, and dialkylzincs such as dimethylzinc, diethylzinc, di-n-propylethylzinc, and diisopropylzinc.

The catalyst of the present invention contains the above-mentioned components (A) and (B), or components (A), (B), and (C), but in addition to these, other catalyst components may be added. It is also possible. The blending ratio of components (A) and (B), or the blending ratio of components (A), (B), and (C) in this catalyst varies depending on various conditions and cannot be unambiguously determined. Usually, the molar ratio of component (A) to component (B) is 1:10 to 10:1, and the molar ratio of component (A) to component (C) is 100:1 to 1:1000.

The catalyst of the present invention as described above exhibits high activity in the production of styrenic polymers having a highly syndiotactic structure. Therefore, the present invention further provides a method for producing a styrenic polymer using the above catalyst.

[0024] In order to produce a styrenic polymer by the method of the present invention, it is possible to produce the styrenic polymer in the presence of a catalyst containing the above-mentioned components (A) and (B), or in the presence of a catalyst containing the above-mentioned components (A), (B), and (C). In the presence of a catalyst containing styrene and/or styrene derivatives (alkylstyrene, alkoxystyrene, halogenated styrene, vinyl benzoate, etc.), styrenic monomers are polymerized (or copolymerized). Here, the method of contacting the catalyst of the present invention with the styrene monomer includes (1) a method of using a reaction product of components (A) and (B) as a catalyst, and (2) contacting the monomer to be polymerized with the reaction product of components (A) and (B).
A method in which component (C) is added to the reaction product of component A) and component (B) to form a catalyst, and a monomer to be polymerized is brought into contact with this; B) A method in which components are added to form a catalyst and the monomer to be polymerized is brought into contact with this, or ■ (A) and (B) are added to the monomer to be polymerized.
), (C) are added one by one and brought into contact with each other. Furthermore, the reaction product of component (A) and component (B) may be isolated and purified in advance. In addition, the above (
It goes without saying that the addition or contact of components A), (B) and (C) can be carried out at a polymerization temperature of -78 to 10
It is also possible to carry out at a temperature of 0°C.

The styrenic monomer may be polymerized in bulk, and aliphatic hydrocarbons such as pentane, hexane, heptane, etc.
Alicyclic hydrocarbons such as cyclohexane or benzene,
It may be carried out in an aromatic hydrocarbon solvent such as toluene or xylene. Further, the polymerization temperature is not particularly limited, but is generally 0 to 110°C, preferably 20 to 90°C.

Furthermore, in order to control the molecular weight of the styrenic polymer obtained, it is effective to carry out the polymerization reaction in the presence of hydrogen.

The styrenic polymer thus obtained has a highly syndiotactic structure. Here, the highly syndiotactic structure in styrenic polymers refers to a highly syndiotactic structure in which the stereochemical structure is highly syndiotactic, i.e., a phenyl group or substituted side chain with respect to the main chain formed from carbon-carbon bonds. It means to have a steric structure in which phenyl groups are alternately positioned in opposite directions, and its tacticity is determined by nuclear magnetic resonance method (13C-NMR method) using carbon isotopes. 13C-N
Tacticity measured by the MR method can be expressed by the proportion of consecutive constituent units, such as dyads if there are two, triads if there are three, and pentads if there are five. ``Styrenic polymer having a highly syndiotactic structure'' mentioned in the invention
means polystyrene, poly(alkyl styrene), poly( halogenated styrene), poly(alkoxystyrene)
, poly(vinyl benzoate), mixtures thereof, or copolymers containing these as main components. In addition, poly(alkylstyrene) here includes poly(methylstyrene), poly(ethylstyrene), poly(
Examples of poly(halogenated styrene) include poly(chlorostyrene) and poly(bromostyrene).
, poly(fluorostyrene), etc. Furthermore, examples of poly(alkoxystyrene) include poly(methoxystyrene) and poly(ethoxystyrene). Among these, particularly preferred styrenic polymers include polystyrene, poly(p-methylstyrene), poly(m-methylstyrene), poly(p-tert-butylstyrene), poly(p-chlorostyrene), poly( (m-chlorostyrene), poly(p-fluorostyrene), and copolymers of styrene and p-methylstyrene.

The styrenic polymer produced by the method of the present invention generally has a weight average molecular weight of 10,000 to 10
,000,000, preferably 100,000 to 5,
000,000, number average molecular weight 5,000 to 5,0
00,000, preferably 50,000 to 2,500
,000 and has high syndioctality as mentioned above. After polymerization, if necessary, it is deashed with a washing solution containing hydrochloric acid, etc., and then washed and dried under reduced pressure to form methyl ethyl ketone, etc. If the soluble content is removed by washing with a solvent and the resulting insoluble content is further treated with chloroform or the like, a highly pure styrenic polymer with extremely high syndiotacticity can be obtained.

[0029] This styrenic polymer having a highly syndiotactic structure has a melting point of 160 to 310°C, and has much better heat resistance than conventional styrenic polymers having an atactic structure.

[0030]

EXAMPLES Next, the present invention will be explained in more detail with reference to Examples and Comparative Examples. Example 1 10 ml of styrene, 2.5 μmol of tri(pentafluorophenyl)boron, and 2.5 μmol of pentamethylcyclopentadienyl titanium trimethyl were sequentially added to a 20 ml container that had been dried and purged with nitrogen, and the mixture was heated at 70°C.
Then, polymerization was carried out for 4 hours. After the reaction was completed, the product was dried to obtain 1.60 g of polymer. This polymer was cut into thin pieces with a thickness of 1 mm or less and subjected to Soxhlet extraction with methyl ethyl ketone for 6 hours.
P) was obtained. As a result, the yield of syndiotactic polystyrene (SPS) was 1.04 g, and the SPS activity was 8.7 kg/g Ti.

Example 2 Except for using 2.5 μmol of pentamethylcyclopentadienyl titanium tribenzyl as the titanium compound.
0.82 g of a polymer was obtained in the same manner as in Example 1. This polymer was cut into thin pieces with a thickness of 1 mm or less and subjected to Soxhlet extraction with methyl ethyl ketone for 6 hours, yielding MIP with a concentration of 59% by weight. As a result, the yield of SPS is 0.48
g, and the SPS activity was 4 kg/g Ti.

Example 3 0.5 g of a polymer was obtained in the same manner as in Example 1, except that 2.5 μmol of pentamethylcyclopentadienyl titanium trimethoxide was used as the titanium compound. This polymer was cut into thin pieces with a thickness of 1 mm or less and subjected to Soxhlet extraction with methyl ethyl ketone for 6 hours, yielding MIP with a concentration of 72% by weight. As a result, the yield of SPS was 0.3
6g, and the SPS activity was 3kg/gTi.

Example 4 0.92 g of a polymer was obtained in the same manner as in Example 1, except that 2.5 μmol of ethyldi(pentafluorophenyl)boron was used as the boron compound. This polymer was cut into thin pieces with a thickness of 1 mm or less and subjected to Soxhlet extraction with methyl ethyl ketone for 6 hours.
I got it. As a result, the yield of SPS was 0.72g,
SPS activity was 6 kg/gTi.

Example 5 10 ml of styrene and 30 μmol of triisobutylaluminum were placed in a 20 ml container that had been dried and purged with nitrogen, and the temperature was raised to 70°C. Next, the bird (
pentafluorophenyl) boron 0.50 μmol, pentamethylcyclopentadienyl titanium trimethyl 0.5
0 μmol was sequentially added and polymerization was carried out at 70° C. for 4 hours. After the reaction was completed, the product was dried to obtain 0.50 g of polymer. This polymer was cut into thin pieces with a thickness of 1 mm or less and subjected to Soxhlet extraction with methyl ethyl ketone for 6 hours.
An extraction residue (MIP) was obtained at 3% by weight. As a result, SP
The yield of S is 0.42g, and the SPS activity is 17.5k
g/gTi.

Example 6 0.48 g of a polymer was obtained in the same manner as in Example 5, except that 0.5 μmol of pentamethylcyclopentadienyl titanium tribenzyl was used as the titanium compound. This polymer was cut into thin pieces with a thickness of 1 mm or less and subjected to Soxhlet extraction with methyl ethyl ketone for 6 hours to obtain an extraction residue (MIP) with a concentration of 78% by weight. As a result, the yield of SPS was 0.37g, and the SPS activity was 15.4kg/
gTi.

Example 7 0.38 g of a polymer was obtained in the same manner as in Example 5, except that 0.5 μmol of pentamethylcyclopentadienyl titanium trimethoxide was used as the titanium compound. This polymer was cut into thin pieces with a thickness of 1 mm or less and subjected to Soxhlet extraction with methyl ethyl ketone for 6 hours.
An extraction residue (MIP) was obtained at 5% by weight. As a result, S.
The yield of PS was 0.32 g, and the SPS activity was 13.5
kg/gTi.

Example 8 The same procedure as in Example 5 was repeated except that 30 μmol of trimethylaluminum was used as the alkylating agent.
6g was obtained. This polymer was cut into thin pieces with a thickness of 1 mm or less and subjected to Soxhlet extraction with methyl ethyl ketone for 6 hours, yielding MIP with a concentration of 93% by weight. As a result, SP
The yield of S was 0.43g, and the SPS activity was 17.9k.
g/gTi.

Example 9 0.75 g of a polymer was obtained in the same manner as in Example 1, except that 2.5 μmol of ethyldi(pentafluorophenyl)boron was used as the boron compound. This polymer was cut into thin pieces with a thickness of 1 mm or less and subjected to Soxhlet extraction with methyl ethyl ketone for 6 hours.
I got it. As a result, the yield of SPS was 0.65g,
SPS activity was 5.4 kg/gTi.

Comparative Example 1 Polymerization was carried out in the same manner as in Example 1 except that tri(pentafluorophenyl)boron was not used, but no polymer could be obtained.

Comparative Example 2 Example 1 except that pentamethylcyclopentadienyl titanium trimethyl was not used in Example 1.
Polymerization was carried out in the same manner as above, but no polymer could be obtained.

Comparative Example 3 Polymerization was carried out in the same manner as in Example 5 except that tri(pentafluorophenyl)boron was not used, but no polymer could be obtained.

Comparative Example 4 Example 5 except that pentamethylcyclopentadienyl titanium trimethyl was not used in Example 5.
Polymerization was carried out in the same manner as above, but no polymer could be obtained.

[0043]

Effects of the Invention The catalyst of the present invention is less expensive than conventional catalysts containing aluminoxane as a main component, and has high activity in producing styrenic polymers having a highly syndiotactic structure. Therefore, according to the method of the invention:
Syndiotactic styrenic polymers can be produced efficiently at low cost.

Claims (5)

[Claims] Claim 1: (A) transition metal compound and (B) general formula (I) BR1 R2 R3 ... (I) [wherein R1, R2 and R3 are each an alkyl group having 1 to 20 carbon atoms or It represents an aryl group having 6 to 20 carbon atoms. ] A catalyst for producing a styrenic polymer, characterized by comprising an organic boron compound represented by the following. 2. A method for producing a styrenic polymer, which comprises using the catalyst according to claim 1 in polymerizing styrene and/or a styrene derivative. 3. (A) transition metal compound, (B) general formula (I) BR1 R2 R3 ... (I) [wherein R1, R2 and R3 are each an alkyl group having 1 to 20 carbon atoms or It represents an aryl group having 6 to 20 carbon atoms. A catalyst for producing a styrenic polymer, comprising an organic boron compound represented by the following formula and (C) an alkylating agent. 4. A method for producing a styrenic polymer, which comprises using the catalyst according to claim 3 in polymerizing styrene and/or a styrene derivative. 5. The transition metal in component (A) is Ti,
The catalyst for producing a styrenic polymer according to claim 1 or 3, which is Zr or Hf.