JP3156970B2 - Polybutene moldings - Google Patents

Description

The present invention relates to a molded article of polybutene-1. More specifically, the present invention relates to a molded product of polybutene-1 having a specific crystal structure.

(Prior art)

Isotactic polybutene-1 has been known for some time, and its use for various uses has been studied. However, polybutene-1 having a syndiotactic structure has not been known.

[Problems to be solved by the invention]

High syndiotacticity polypropylene was first discovered by JAEWEN et al. (J. Am. Che
m. Soc., 1988, 110, 6255-6256) can be produced by using a catalyst composed of a transition metal compound having an asymmetric ligand and an aluminoxane. Butene-1 sufficiently purified using this catalyst is used. It has been found by us that the polymerization of polybutene-1 gives extremely high syndiotacticity. (Japanese Patent Application No. 1-141168) However, the crystallinity of this product has not been fully understood.

[Means for solving the problem]

Means for Solving the Problems The present inventors diligently searched for crystallized polybutene-1, and found that crystalline polybutene-1 having a specific structure can be produced, and completed the present invention.

That is, in the present invention, the lattice constants determined by X-ray diffraction obtained by molding polybutene-1 having a syndiotactic structure are a = 9.94, b = 13.9, c = 20.4 °, and β = 131.
゜ is a monoclinic polybutene-1 molded product.

The present invention will be further described by showing an example of the manufacturing method. Polybutene-1 having a high stereoregularity syndiotactic structure that can be synthesized by a method described below is melt-molded, or is dissolved in a hydrocarbon solvent such as toluene, cast, and the solvent is removed by evaporation. A molded product of polybutene-1 having a certain crystal structure can be obtained.

Syndiotactic polybutene-1 used here is:
For example, it can be produced by polymerizing butene-1 using a catalyst comprising an aluminoxane and a transition metal compound having an asymmetric ligand first discovered by JAEWEN et al. Here, preferably, the transition metal compound having an asymmetric ligand has a high purity (an inactive impurity such as lithium chloride does not cause any problem, but a transition metal compound having a structure in which one ligand is removed is particularly preferable. Less is required.)
It is preferable to use a polymer having a syndiotactic pentad fraction (Macromolecules 1983 vol16 786-7).
Polybutene-1 having good tacticity such that 90) is 0.5 or more, particularly preferably 0.7 or more, is preferably used.

Examples of the transition metal compound having an asymmetric ligand include isopropyl (cyclopentadienyl-1-fluorenyl) hafnium dichloride or isopropyl (cyclopentadienyl-1-fluorenyl) zirconium dichloride described in the above literature. , And as the aluminoxane, a general formula: (Wherein R is a hydrocarbon residue having 1 to 3 carbon atoms). In particular, methylaluminoxane wherein R is a methyl group and n is 5 or more, preferably 10 or more is used. 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. In general, the polymerization is carried out at a temperature of -100 to 200 ° C. and at a pressure of normal pressure to 100 kg / cm ² . Preferably, it is -100 to 100 ° C and normal pressure to 50 kg / cm ² .

When the above catalyst is used, a polymer having a narrow molecular weight distribution by performing substantially one-stage polymerization during polymerization and having a ratio of the weight average molecular weight to the number average molecular weight measured by gel permeation chromatography at 135 ° C. which is usually about 1.5 to 3.5. However, it is effective to use two kinds of transition metal compounds (for example, it is effective to use two kinds of metals such as zirconium and hafnium) or to use two kinds of compounds having different molecular weights.
Those having a wide molecular weight distribution of 3.5 or more can be produced by mixing more than one kind, and those having any molecular weight distribution can be used in the present invention. The preferred molecular weight is generally about 0.5 to 20.0 dl / g as the intrinsic viscosity measured with a 135 ° C. tetralin solution.

Polybutene-1 having a syndiotactic structure obtained by the above method was first heated and melted as described above to be molded into a specific shape, or dissolved in a hydrocarbon solvent having 5 to 20 carbon atoms, and then cast molded. Thereafter, the solvent is removed by evaporation to obtain a molded product. The molded article is then stretched at a low temperature (preferably 40 ° C. or lower). The stretching ratio is relatively large, preferably 3 times or more, whereby a molded product having substantially one crystal structure can be obtained. If the stretching ratio is small, two or more crystal forms are mixed, which is not preferable. FIG. 1 shows a photograph of an X-ray diffraction image of the molded product thus produced having substantially one crystal structure, taken with a Weissenberg camera, using Cu-Kα radiation. The lattice constant determined from the measurement results of X-ray diffraction is a monoclinic crystal in which a = 9.94, b = 13.9, c = 20.4 °, and β = 131 °.

〔Example〕

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

Example 1 5 mg of isopropyl (cyclopentadienyl-1-fluorenyl) zirconium dichloride obtained by lithiation of isopropylcyclopentadienyl-1-fluorene synthesized according to a conventional method, reaction with zirconium tetrachloride, and recrystallization were obtained. Using 0.34 g of methylaluminoxane manufactured by Toyo Akzo Co., Ltd. (degree of polymerization 16.1), 40 g of butene-1 was stirred and mixed at 25 ° C for 5 hours in an autoclave having an internal volume of 200 mml. After the reaction, unreacted butene-1 was removed by evaporation, and 100 ml of hexane was added to the remaining solid matter, and 50 ml of ketanol was further added.
The mixture was treated at 60 ° C. for 30 minutes, and the hexane solution was further washed with water. The hexane solution was concentrated to about 30 ml, and then cast to obtain a sheet. Sheet 30 at 30 ℃
After drying for an hour, hexane was completely removed. A part of this molded product was dissolved, the syndiotactic pentad fraction measured by ¹³ C-NMR was 0.92, and the molecular weight in terms of propylene measured by gel permeation chromatography was 27500, The average molecular weight was 42,500. This sheet was stretched 5 times at 25 ° C. to obtain a molded product. Fig. 1 shows an X-ray fiber photograph of this molded product. From these results, the lattice constants are a = 9.94, b = 13.9, c = 20.4 °, β
It can be seen that this is a monoclinic system where = 131 °.

〔The invention's effect〕

The molded article of the present invention is crystalline at room temperature and can be expected to have various uses.

[Brief description of the drawings]

FIG. 1 is a photograph of the result of measurement of X-ray diffraction of a molded product of polybutene-1 of the present invention instead of the drawing.

Claims (1)

(57) [Claims] 1. A monoclinic wherein the lattice constants determined by X-ray diffraction obtained by molding polybutene-1 having a syndiotactic structure are a = 9.94, b = 13.9, c = 20.4 °, and β = 131 °. A molded product of polybutene-1 which is a crystal.