JP2001002721A - Production of norbornene-based cyclic olefin polymer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a norbornene-based cyclic olefin polymer capable of producing the norbornene-based cyclic olefin polymer dissolvable in a solvent and formulated and obtain a block copolymer containing the norbornene-based cyclic olefin polymer as a block unit. SOLUTION: A norbornene-based cyclic olefin is polymerized by using a metallocene catalyst comprising a metal compound in which two cyclopentadienyl rings 1 are bonded to one active central metal 2. The two cyclopentadienyl rings 1 in the metallocene catalyst are crosslinked and the active central metal 2 has no asymmetric structure. The two cyclopentadienyl rings 1 are crosslinked with a crosslinking group 3 comprising a silylene or methylene.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a norbornene-based cyclic olefin polymer, and a block copolymer containing a norbornene-based cyclic olefin unit.

[0002]

2. Description of the Related Art As shown in FIG. 6, a metallocene is a metal compound in which two cyclopentadienyl rings 91 are bonded to an active center metal 92 (for example, Zr). I have. As a specific example, it is known to carry out a copolymerization reaction between norbornene and ethylene and / or an α-olefin.

[0003]

However, the above-mentioned metallocene catalyst can promote the copolymerization of norbornene with ethylene and / or an α-olefin as described above, but cannot promote the polymerization reaction of norbornene alone. The reason is that the bond angle (byte angle) α between the cyclopentadienyl ring 91 and the active center metal 92 of the metallocene catalyst is large. When the bonding angle α is large, the space on the side where the polymer chains grow is narrowed. Therefore, it is considered that homopolymerization of a cyclic olefin having a large steric hindrance such as norbornene does not proceed.

Therefore, it is conceivable to reduce the bond angle (byte angle) α between the cyclopentadienyl ring and the active center metal by bridging the cyclopentadienyl rings of the metallocene catalyst. As a result, a sufficient space is secured on the side where the polymer chains grow, so that the homopolymerization reaction of norbornene proceeds. However, the conventionally known bridged metallocene catalyst has C2 symmetry (asymmetric structure), so that the resulting polymer has a structure with high stereoregularity.
Therefore, the produced polymer is hardly dissolved in the solvent and hardly melted, so that shaping becomes impossible.

In view of the above problems, the present invention provides a method for producing a norbornene-based cyclic olefin polymer, which is capable of producing a norbornene-based cyclic olefin polymer which can be dissolved in a solvent and which can be shaped. An object is to provide a block copolymer containing an olefin polymer as a block unit.

[0006]

The invention of claim 1 is a method for polymerizing a norbornene-based cyclic olefin using a metallocene catalyst comprising a metal compound in which two cyclopentadienyl rings are bonded to an active center metal, There is a method for producing a norbornene-based cyclic olefin polymer, wherein two cyclopentadienyl rings are cross-linked by a cross-linking group, and the metallocene catalyst has no asymmetric structure in the active center metal.

In the present invention, the metallocene catalyst is 2
A polymerization catalyst comprising a metal compound having two cyclopentadienyl rings bonded to an active center metal. As illustrated in FIG. 1, the cyclopentadienyl rings 1 in the metallocene catalyst are cross-linked by a cross-linking group (Y) 3.
Therefore, the bonding angle (byte angle) α between the cyclopentadienyl ring 1 and the active center metal (M) 2 can be reduced. As a result, a sufficient space is secured on the side where the polymer chains grow, so that the polymerization reaction proceeds.

The metallocene catalyst of the present invention is
The active center metal does not have an asymmetric structure, and the group bonded to the active center metal has a C2v symmetric relationship with respect to the active center metal. That is, as shown in FIG.
Two cyclopentadienyl rings 1 are bonded to each other and have a symmetric structure with respect to the active center metal 2. Therefore, according to the metallocene catalyst of the present invention, a norbornene-based cyclic olefin polymer having a random (irregular) three-dimensional structure can be polymerized. therefore,
The polymer is soluble in a solvent, easily melts, and can be shaped.

The random three-dimensional structure is a mixture of a di-isotactic structure shown in FIG. 2 (a) and a di-syndiotactic structure shown in FIG. 2 (b) in one molecular chain. This mixed structure is generally called a diheterotactic structure. FIG. 2 shows a case where the polymerized unit is norbornene, but the production method of the present invention is not limited to this.

The norbornene-based cyclic olefin polymer obtained by this production method has a glass transition temperature of 35.
Since the temperature is as high as 0 ° C. or higher and the thermal decomposition temperature is as high as 400 ° C. or more, it has excellent heat resistance. In addition, a transparent molded article (film or the like) which is amorphous and has low birefringence can be molded.

The bridging group bridging between the two cyclopentadienyl rings preferably has one or two atoms as bridging skeleton atoms. Thereby, the bonding angle α between the cyclopentadienyl ring and the active center metal is reduced, and the activity of the polymerization catalyst is improved. In particular, it is desirable that the number of the crosslinking skeleton atoms of the crosslinking group is one. The shorter the bridging group,
This is because the bonding angle α becomes small and a high catalytic activity is exhibited.

As described in claim 2, the bridging group bridging between the two cyclopentadienyl rings is silylene (—Si (CH ₃ ) ₂ —), methylene (—CH ₂ —),
Alternatively, it is preferably crosslinked with ethylene (—CH ₂ CH ₂ —). Each of these has one bridging skeleton atom.
This is because the catalyst activity is high because the number is two or two.

A substituent may be bonded to the cyclopentadienyl ring. The substituent may be bonded to any position of the cyclopentadienyl ring. What is important here is that the compound has a C2v symmetric structure, that is, the substituents bonded to the two cyclopentadienyl rings are the same as each other and bonded to the same position. This is because the metallocene catalyst does not have an asymmetric structure.
For example, as shown in FIG. 3, there is a structure in which, in two cyclopentadienyl rings, the same substituent R is bonded at positions on both sides of a crosslinking group (silyl group) bonding site. In addition,
In FIG. 3 and FIG. 4 described later, Me represents a methyl group.

The above cyclopentadienyl ring is preferably unsubstituted. When a substituent is bonded, the substituent is preferably a methyl group, an ethyl group or an isopropyl group. Is preferably a methyl group.
If the substituent is large, the catalytic activity may be reduced. The substituent can be introduced at a site other than the site to which the crosslinking group of the cyclopentadienyl ring is bonded.

Further, as shown in FIG.
In the case where the acid valence of is 4, the divalent bonding group (X) 4 is bonded to the active center metal 2 in addition to the two cyclopentadienyl rings 1. Such a linking group 4 includes C
There are halogen atoms such as l (chlorine), Br (bromine) and I (iodine), and alkyl groups such as methyl group, ethyl group, propyl group and butyl group. When a plurality of bonding groups are bonded, each bonding group may be different from or different from each other.

The active center metal (M) includes, for example, Zr (zirconium), Ti (titanium), Hf (hafnium) and the like.

A specific example of the metallocene catalyst is, for example, [dimethylbis (cyclopentadienyl) silyl].
Zirconium dichloride, [dimethylbis (cyclopentadienyl) silyl] zirconium dibromide, ethylenebis (cyclopentadienyl) zirconium dichloride, ethylenebis (cyclopentadienyl) zirconium dibromide, dimethyl [dimethylbis (cyclopentadienyl) ) Silyl] zirconium and the like.

The metallocene catalyst is added to the polymerization reaction solution together with the norbornene-based cyclic olefin monomer to carry out the polymerization reaction. The metallocene catalyst promotes the polymerization reaction in the presence of a promoter. As a co-catalyst, for example, MAO
(Methylaluminoxane), MMAO (Modified Methy)
laluminoxane; a mixture of about 75% methylaluminoxane and about 25% isobutylaluminoxane), and boron compounds such as tetrakispentafluorophenylborane.

The monomer polymerized by the metallocene catalyst is a norbornene-based cyclic olefin, and specific examples thereof include norbornene, tetracyclododecene, dicyclopentadiene, and ethylidene norbornene. The metallocene catalyst can promote not only homopolymerization but also copolymerization with α-olefins such as ethylene and propylene.

The norbornene-based cyclic olefin polymer having a random three-dimensional structure can be used, for example, for resin glass and optical recording materials.

A norbornene-based cyclic olefin polymer obtained by homopolymerizing a norbornene-based cyclic olefin with a metallocene catalyst can be a constituent unit of ethylene and / or an α-olefin and a block copolymer. That is, as described in claim 3, a norbornene-based cyclic olefin unit (a) having a random steric structure and a double bond-containing monomer unit (b) are block-copolymerized. There are block copolymers.

The above-mentioned block copolymer is obtained by subjecting the above-mentioned norbornene-based cyclic olefin polymer having a random steric structure to a block unit (a) and subjecting the α-polyolefin block unit (b) to block copolymerization. Therefore, it has both high rigidity, toughness and shapeability.

The norbornene-based cyclic olefin unit (a) having a random steric structure can be obtained by the above-mentioned method for producing a norbornene-based cyclic olefin polymer. The degree of polymerization of this block unit (a) is 10 to 10,
000, more preferably 100 to
5,000.

As in the invention of claim 4, the double bond-containing monomer unit (b) is preferably ethylene and / or an α-olefin. Examples of the α-olefin include, but are not limited to, polyethylene and polypropylene. The polymerization degree of the block unit (a) is preferably from 10 to 100,000, and more preferably from 100 to 50,000.

The block copolymerization of the block units (a) and (b) can be carried out using the metallocene catalyst of the present invention. The block copolymer can be used, for example, for resin glass, optical recording materials, thermoplastic elastomers, and the like.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described with reference to examples and comparative examples. Example 1 As shown in FIG. 5, this example is a method for producing polynorbornene 6 by polymerizing norbornene 5 with a metallocene catalyst. First, in a glove box under an argon atmosphere, [dimethylbis (cyclopentadienyl) silyl]
18 mg of zirconium dichloride (FIG. 4), 1.50 g of methylaluminoxane (MAO), and 15 g of toluene
Was mixed to prepare a catalyst solution. Also, 8 g of norbornene as a monomer was dissolved in 15 g of toluene in an atmosphere of argon in a glove box to obtain a monomer solution.

While maintaining the temperature of the monomer solution at 50 ° C.,
Add the whole amount into the catalyst solution with stirring,
Stirred at 50 ° C. for 8 hours. The polymerization proceeded rapidly in a homogeneous system to obtain a viscous polymer solution. The toluene solution containing the produced polymer is taken out of the glove box and added to a large amount of hydrochloric acid-acidic methanol to precipitate the polymer.
Isolated. Subsequently, methanol was removed by filtration, followed by vacuum drying at room temperature for 24 hours to obtain 7.6 g of a polymer. This polymer was polynorbornene.

The resulting polymer is soluble in an organic solvent and is a polymer obtained by addition reaction of the norbornene double bond (2,3 position) from ¹ H and ¹³ C NMR measurements, not a ring-opening metathesis polymerization reaction product. I understand. Also, G
The molecular weight determined from PC (polystyrene conversion) is Hw
(Weight average molecular weight) was 69000. The thermal decomposition onset temperature (under a nitrogen atmosphere) determined by thermogravimetric loss measurement (TGA) was 402 ° C.

Example 2 The same operation as in Example 1 was carried out except that tetracyclododecene was used as the monomer instead of norbornene, to obtain 7.5 g (yield 94%) of a polymer. This polymer is poly (tetracyclododecene) and Mw =
It was 81,000.

Example 3 The same operation as in Example 1 was carried out except that dicyclopentadiene was used instead of norbornene as a monomer, to obtain 7.7 g (yield: 96%) of a polymer. This polymer is poly (dicyclopentadiene) and Mw =
73,500.

Example 4 The procedure of Example 1 was repeated, except that ethylidene norbornene was used in place of norbornene, to obtain 7.3 g (yield: 91%) of a polymer. This polymer is poly (ethylidene norbornene),
= 67,500.

Example 5 The procedure of Example 1 was repeated, except that a mixture of norbornene and ethylene was used instead of norbornene alone, to obtain 7.4 g (yield 93%) of the polymer. Obtained. This polymer was a norbornene-ethylene copolymer, and Mw was 73,500.

Example 6 The same operation as in Example 1 was carried out except that ethylenebis (cyclopentadienyl) zirconium dichloride was used instead of [dimethylbis (cyclopentadienyl) silyl] zirconium dichloride as a catalyst. 7.0
g (88% yield) of polynorbornene (Mw = 62.0)
00).

Example 7 In Example 1, instead of [dimethylbis (cyclopentadienyl) silyl] zirconium dichloride, dimethyl [dimethylbis (cyclopentadienyl) silyl] zirconium and tetrakispentafluorophenylborane were used. Except that the complex No. 1 was used as a catalyst, the same operation was performed to polymerize norbornene. This gives
7.4 g (93% yield) of polynorbornene (Mw = 7)
4,500).

Example 8 7.4 g of a norbornene-ethylene block copolymer (93% yield) was obtained in the same manner as in Example 5 except that ethylene was introduced after the end of the norbornene polymerization. Mw was 73,800.

Comparative Example 1 Norbornene was polymerized in the same manner as in Example 1 except that zirconocene dichloride was used as a catalyst instead of [dimethylbis (cyclopentadienyl) silyl] zirconium dichloride. This gives
Although polynorbornene was obtained, the yield was 0.45 g (yield 6
%).

Comparative Example 2 The procedure of Example 1 was repeated, except that ethylenebis (indenyl) zirconium dichloride was used instead of [dimethylbis (cyclopentadienyl) silyl] zirconium dichloride as a catalyst. Polymerization was performed. As a result, 6.5 g (yield 81%) of polynorbornene was obtained, but was insoluble and insoluble in the solvent.

[0038]

According to the present invention, it is possible to produce a norbornene-based cyclic olefin polymer which can be dissolved in a solvent and which can be shaped, a method for producing a norbornene-based cyclic olefin polymer, and a norbornene-based cyclic olefin polymer. Can be provided as a block unit.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a metallocene catalyst according to the present invention.

FIGS. 2 (a) and 2 (b) show the three-dimensional structure of polynorbornene in the present invention.

FIG. 3 is an explanatory view of a metallocene catalyst for illustrating the position of a substituent capable of bonding to a cyclopentadienyl ring in the present invention.

FIG. 4 is an explanatory diagram showing a chemical formula of a metallocene catalyst in Example 1.

FIG. 5 is an explanatory diagram showing a polymerization reaction of norbornene in Example 1.

FIG. 6 is an explanatory diagram showing a chemical formula of a metallocene catalyst in a conventional example.

[Explanation of symbols]

 1. . . 1. cyclopentadienyl ring, . . 2. active center metal; . . 3. a crosslinking group; . . A linking group, 5. . . 5. norbornene, . . Polynorbornene,

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Yumitsu Usuki 41-cho, Yokomichi, Nagakute-machi, Aichi-gun, Aichi Prefecture F-term in Toyota Central R & D Laboratories Co., Ltd. 4J026 HA02 HA13 HA27 HA39 HB03 HB04 HB27 HB39 HB45 HB48 HE01 4J028 AA01A AB00A AB01A AC01A AC08A AC09A AC10A AC26A AC27A AC28A BA00A BA01B BA02B BB00A BB00B BB01B BC12B BC25B EA01 EA02 EB02 EB04 EB17 EB18 EB01 EC02 ED01 EC02 ED01

Claims (4)

[Claims] 1. A method for polymerizing a norbornene-based cyclic olefin using a metallocene catalyst comprising a metal compound in which two cyclopentadienyl rings are bonded to an active center metal, comprising: A method for producing a norbornene-based cyclic olefin polymer, characterized in that the spaces are cross-linked by a cross-linking group and the metallocene catalyst has no asymmetric structure in the active center metal. 2. The method for producing a norbornene-based cyclic olefin polymer according to claim 1, wherein the crosslinking group that bridges between the two cyclopentadienyl rings is silylene, methylene or ethylene. 3. A block copolymer comprising a block copolymer of a norbornene-based cyclic olefin unit (a) having a random steric structure and a double bond-containing monomer unit (b). 4. The block copolymer according to claim 3, wherein the double bond-containing monomer unit (b) is ethylene and / or an α-olefin.