JP2968815B2 - Method for producing copolymer - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing a copolymer containing an —OH group in a side chain. More specifically, the present invention relates to a method for producing a copolymer comprising copolymerizing alkenylsilane and an α-olefin using a specific catalyst and then performing a specific treatment.

[Prior art] A copolymer of an unsaturated compound containing an -OH group in a side chain and an α-olefin can be expected to have various functions utilizing an -OH group, but there is no known method for obtaining such a product at low cost. How was not done.

[Problems to be solved by the invention]

When an unsaturated compound containing an -OH group in the side chain is used as a comonomer, the polymerization catalyst for α-olefin has little activity and it is extremely difficult to obtain such a copolymer. On the other hand, in the case of copolymerization, it is conceivable to use one having a structure that is not an -OH group that does not hinder the performance of the catalyst, and then change to the -OH group, for example, using a special boron-containing monomer. The method is known (Macromolecules
23 378-382 (1990) Ramakrishman S. et al.) Had the problem that the monomer was expensive and the polymerization activity was insufficient.

[Means for solving the problem]

The present inventors have enthusiastically searched for a method for producing a copolymer having an —OH group in a side chain by solving the above problems and completed the present invention.

That is, the present invention uses a transition metal compound having cyclopentadiene or a derivative thereof as a ligand and a catalyst comprising aluminoxane, copolymerizes an α-olefin having 2 to 20 carbon atoms and alkenylsilane, and then trialkylamine oxide. A method for producing a stereoregular copolymer containing an -OH group, which comprises performing a heat treatment in the presence of potassium hydrogen fluoride.

In the present invention, first, a copolymer of alkenylsilane is synthesized, and many catalyst systems are already known as catalysts used for producing this copolymer. For example, W. Kaminskyra et al. Polymer Bulletin vol9 464-469,
Angew.Chem., Vol24 507 (1985), JAEwen et al., J. Am. Che
m., vol 106, 6355 (1984), vol 110, 6255 (1988), and many other patents have been published.

Specifically, as the transition metal compound, zirconium having cyclopentadiene or a derivative thereof as a ligand,
Alternatively, an organometallic compound of hafnium can be used. Above all, as a catalyst for giving a stereoregular poly-α-olefin, one having an ethylenebisindenyl group or a hydride thereof as a ligand, or one having two indenyl groups bonded by silicon, is an isotactic polyolefin. In addition, those having an asymmetric ligand in which a fluorenyl group and a cyclopentadienyl group are bonded by a methyl group can give a syndiotactic polyolefin, and therefore, the obtained copolymer also has stereoregularity. Become. More specifically, biscyclopentadienyl zirconium dichloride as having a symmetric ligand,
Alternatively, the cyclopentadienyl group having a substituent, ethylenebisindenyl zirconium dichloride, or a hydride thereof, or a transition metal compound having an asymmetric ligand may be isopropyl (cyclopentadienyl-1-fluorenyl). ) Hafnium dichloride or isopropyl (cyclopentadienyl-1-fluorenyl) zirconium dichloride. Further, as the aluminoxane used in combination, a general formula, (Wherein R is a hydrocarbon residue having 1 to 3 carbon atoms). Examples thereof include methylaluminoxane wherein R is a methyl group and n is 5 or more, preferably 10 or more. You. The use ratio of the aluminoxane to the transition metal compound is 10 to 100,000,000 mole times, usually 50 to 5000.
It is molar times. The polymerization conditions are not particularly limited, and a solvent polymerization method using an inert medium, a bulk polymerization method substantially free of an inert medium, and a gas phase polymerization method can be used. Here, alkenylsilane is represented by the general formula: H ₂ C = CH
— (CH ₂ ) _n —SiR ₃ (wherein R is a hydrogen atom, a halogen atom or a saturated hydrocarbon residue having 1 to 20 carbon atoms, and n is 0 to 20), specifically, vinylsilane, allylsilane, butenylsilane And pentenyl silane, hexenyl silane, and those in which H of the Si-H bond is substituted with a halogen atom or a saturated hydrocarbon residue having 1 to 20 carbon atoms, and particularly, a saturated hydrocarbon residue having 1 to 20 carbon atoms. Is preferably used. As the α- olefin is exemplified α- olefin having 2 to 20 carbon atoms, the general formula H ₂
C = CH- (CH ₂₎ other α- olefin represented by _n -CH ₃ - (CH ₂₎ was changed branched into _n -CH ₃ group 3-methylbutene-1,4-methylpentene-1,4, Branched α-olefins such as 4-dimethylpentene-1 can also be exemplified. The polymerization temperature is -100 to 200 ° C, and the polymerization pressure is normal pressure to 100 kg / cm.
It is common to do in ³ . Preferably −100 to 100 ° C.,
Normal pressure-50 kg / cm ² .

The above-mentioned catalyst system has extremely high activity not only for olefins but also for alkenylsilanes, and is capable of copolymerizing a large amount of alkenylsilane. As a result, the content of the monomer unit having an -OH group is 0.01 mol% or more. Can be produced.

In the present invention, the copolymer is then subjected to a heat treatment in the presence of a trialkylamine oxide and potassium hydrogen fluoride to form an -OH bond. The detailed conditions include, for example, Tetorahedrone Letter 27 75 (1986) (H. Sa
kurai et al.), and the conditions can be adopted.
As the trialkylamine oxide, those having 1 to 6 carbon atoms as an alkyl group can be used.
Preferably it is 0.1 to 100 molar times. The amount of potassium hydrogen fluoride used is 0.01 to 10 with respect to the alkenylsilane unit.
The molar ratio is 00 molar times, preferably 0.1 to 100 molar times. In this reaction, it is preferable to use a solvent, which has 5 to 25 carbon atoms.
Can be preferably used. The reaction temperature is usually from room temperature to 300 ° C.

〔Example〕

 Hereinafter, the present invention will be described with reference to Examples.

Example 1 Ethylenebis (4,5,6,7) obtained by lithiating ethylenebisindene synthesized by an ordinary method in an autoclave having a content volume of 300 ml, reacting with zirconium tetrachloride and hydrogenating it.
-Tetrahydroindenyl) zirconium dichloride
10 mg and 1.36 g of methylaluminoxane having a degree of polymerization of about 16 manufactured by Toyo Akzo Co., Ltd. were dissolved in 100 ml of toluene, and 20 g of trimethylallylsilane and 60 g of propylene were added, followed by polymerization at 30 ° C. for 2 hours. After the polymerization, unreacted monomers were purged, and the powder obtained by filtration was washed four times with methanol 1 and dried under reduced pressure at 80 ° C. to obtain 48 g of a polymer.
Analysis of the silicon content revealed that the silicon content was 1.9 wt% and that allyltrimethylsilane was contained at 7.7 wt%.
5 g of this polymer was dispersed in 40 ml of toluene, and 40 ml of water, 2 g of trimethylamine oxide, and 2.5 g of potassium hydrogen fluoride were added.
The reaction was carried out at 100 ° C. for 10 hours. After the reaction, the toluene layer was separated, cooled and filtered to obtain a polymer. This polymer contains 3.9 wt% of unreacted allyltrimethyl units by silicon analysis.
3400 cm ^-1 , 10
An absorption of an -OH group (about 1.9 wt% as a monomer unit) was observed at 40 cm ^-1, and when analyzed by ¹³ C-NMR, about 21.7
This polypropylene is observed in ppm and has an isotactic structure. The intrinsic viscosity (hereinafter referred to as η) measured at 135 ° C. tetralin solution is 0.28 dl / g, and the ratio of the weight average molecular weight to the number average molecular weight measured at 135 ° C. 1,2,4-trichlorobenzene solution (hereinafter, referred to as η) MW / MN) was 2.5.

Example 2 37 g of a polymer was obtained in the same manner as in Example 1 except that trimethylvinylsilane was used instead of trimethylallylsilane, and the content of trimethylvinylsilane was 8.1 wt.
%, Using this polymer and treating in the same manner as in Example 1.
A copolymer containing a group was obtained. η is 0.26dl / g, MW / MN is
According to ¹³ C-NMR, absorption by propylene methyl group was observed at about 21.7 ppm, indicating that the polymer has an isotactic structure. According to the analysis of silicon in this polymer, 4.9% by weight of vinyltrimethylsilane units remain.
According to the infrared absorption spectrum, absorption of a -OH group (1.5 wt% as a monomer unit) was observed at 3400 cm ^-1 .

Example 3 The same procedures as in Example 1 were carried out except that butene-1 was used instead of propylene, and the content of allyltrimethylsilane was 15.5.
16 g of a wt% copolymer was obtained.
A copolymer containing an H group was obtained. η is 0.20dl / g, MW / MN is
It was 2.5. According to the infrared absorption spectrum of this polymer, absorption of an -OH group was observed at 3400 cm ^-1 .

〔The invention's effect〕

According to the method of the present invention, a copolymer that can be expected to have various functions can be efficiently produced, and is extremely valuable industrially.

[Brief description of the drawings]

FIG. 1 is an infrared absorption spectrum of the copolymer obtained in Example 1, and FIG. 2 is an infrared absorption spectrum of a copolymer of propylene and allyltrimethylsilane.

Claims (1)

(57) [Claims] An alkenylsilane having 2 to 20 carbon atoms is copolymerized with a catalyst comprising an aluminoxane and a transition metal compound having cyclopentadiene or a derivative thereof as a ligand. A method for producing a stereoregular copolymer containing an -OH group, which is heat-treated in the presence of potassium hydrogen fluoride.