JP3142978B2 - Method for producing crosslinked polyolefin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a crosslinked polyolefin. More specifically, the present invention relates to a method for crosslinking a polyolefin, which comprises treating a specific copolymer with a specific catalyst.

[0002]

2. Description of the Related Art Cross-linking of polyolefins for the purpose of improving the properties of polyolefins at high temperatures, solvent resistance, mechanical properties, and the like is widely performed, and among them, a method using a copolymer of alkenylsilane and olefin is widely used. It is an excellent method for efficiently cross-linking polyolefin,
In particular, the method using a catalyst is an excellent method that can efficiently cross-link even a copolymer having a small alkenylsilane content.

[0003]

The above-mentioned method of crosslinking an alkenylsilane copolymer with a catalyst is an excellent method, but the development of a catalyst having higher performance is desired.

[0004]

Means for Solving the Problems The present inventors diligently studied a cross-linking method which solved the above problems, found that a specific catalyst was effective, and completed the present invention.

That is, the present invention provides a method for producing a crosslinked polyolefin by treating a copolymer of an alkenylsilane and an olefin or a mixture of a copolymer of an alkenylsilane and an olefin and a polyolefin with a catalyst. A method for producing a crosslinked polyolefin, characterized by using a cyclopentadienyl complex.

In the present invention, alkenylsilanes having at least one Si—H bond are preferably used. For example, a compound represented by the following general formula (Formula 1):

[0007]

Embedded image H ₂ C = CH— (CH ₂ ) _n —SiH _P R _3-P (where n is 0 to 12, p is 1 to 3, and R is a hydrocarbon residue having 1 to 12 carbon atoms). ) Can be exemplified, specifically, vinyl silane,
Examples thereof include allylsilane, butenylsilane, pentenylsilane, and compounds in which H of Si—H bond in some of these monomers is substituted with chloro.

As the olefin, a compound represented by the following general formula (Formula 2):

[0009]

Embedded image H ₂ CHCH—R (where R is hydrogen or a hydrocarbon residue having 1 to 12 carbon atoms)
Can be exemplified, specifically, ethylene, propylene, butene
In addition to α-olefins such as -1, pentene-1, hexene-1, 2-methylpentene, heptene-1, and octene-1, styrene or a derivative thereof is also exemplified.

In the present invention, the method for producing the alkenylsilane-olefin copolymer is not limited.
In addition to the solvent method using an inert solvent, a bulk polymerization method and a gas phase polymerization method can be employed.

As the catalyst used for the polymerization, a catalyst comprising a transition metal compound and an organometallic compound is used. As the transition metal compound, titanium halide is preferably used, and as the organometallic compound, an organoaluminum compound is preferably used.

For example, titanium tetrachloride is converted to metallic aluminum,
A catalyst system comprising titanium trichloride obtained by reduction with hydrogen or organoaluminum, modified with an electron-donating compound, an organoaluminum compound, and, if necessary, an electron-donating compound such as an oxygen-containing organic compound, or a halogenated compound. A catalyst comprising a transition metal compound catalyst obtained by supporting titanium halide on a carrier such as magnesium or those obtained by treating them with an electron donating compound and an organoaluminum compound and, if necessary, an oxygen-containing organic compound. The system, or the reaction product of magnesium chloride and alcohol, is dissolved in a hydrocarbon solvent, and then treated with a precipitant such as titanium tetrachloride to make it insoluble in the hydrocarbon solvent. Transition obtained by treating with a compound of formula (1) and then treating with a titanium halide Group compound catalyst and an organoaluminum compound, the catalyst system and the like formed of an electron-donating compound such as oxygen-containing organic compound optionally (e.g., following various examples in the literature are described .Ziegler-Natta Cataly
sts and Polymerization by John Boor Jr (Academic Pr
ess), Journal of Macromorecular Science Reviews in
Macromolecular Chemistry and Physics, C24 (3) 355-38
5 (1984) and C25 (1) 578-597 (1985)).

Alternatively, the polymerization can be carried out using a catalyst comprising a transition metal catalyst soluble in a hydrocarbon solvent and an aluminoxane.

As the electron donating compound, oxygen-containing compounds such as ethers, esters, orthoesters, and alkoxysilicon compounds can be preferably exemplified. In addition, alcohols, aldehydes, water and the like can also be used. Examples of the organoaluminum compound include trialkylaluminum, dialkylaluminum halide, alkylaluminum sesquihalide, and alkylaluminum dihalide.Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, and a hexyl group. Examples of the halide include chlorine, bromine and iodine.
Aluminoxane, which is an oligomer to a polymer obtained by reacting the above-mentioned organoaluminum with water or water of crystallization, can also be used.

Here, the polymerization ratio of the alkenylsilane and the olefin is not particularly limited, but when it is used by mixing with another polyolefin, the alkenylsilane is usually used.
It is about 0.01 to 30 mol%, preferably 0.1 to 10 mol%, and when used alone, it is preferably 0.001 to 10 mol%.

The molecular weight of the polymer is not particularly limited, but a preferred molecular weight is about 0.1 to 10 dl / g as measured by a tetralin solution at 135 ° C. In the polymerization, two or more olefins may be used as a mixture.

In the present invention, the above-mentioned copolymer and polyolefin can be used as a mixture if necessary. As the polyolefin to be used, an olefin represented by the above general formula (Formula 2), specifically, ethylene, propylene, butene
-1, pentene-1, hexene-1, 2-methylpentene, heptene-1, octene-1, and other α-olefins, homopolymers of styrene or its derivatives, random copolymers of each other, or first A so-called block copolymer produced by copolymerizing an olefin alone or a small amount of another olefin and then copolymerizing two or more olefins is exemplified.

The methods for producing these polyolefins are already known, and various brands are available on the market. Alternatively, the alkenyl silane can be produced by using the same method as that for producing the copolymer of olefin and alkenyl silane except that alkenyl silane is not used. When the polyolefin is mixed with the alkenylsilane and olefin copolymer, the ratio of the copolymer to the polyolefin is 1: 0.00.
It is about 1-1: 1000.

The present invention is characterized in that a lanthanide-based cyclopentadienyl complex is used as a catalyst. Specifically, a lanthanide-based metal such as Sm, Y, Yb, Lu or the like is used in combination with cyclopentadiene or the like. A compound having a ligand having an alkyl residue having 1 to 12 carbon atoms, an alkylsilyl residue and an alkoxy group bonded thereto, or an indenyl group, a fluorenyl group or a hydride thereof, or two cyclopentadienyl groups Compounds in which elements mutually bonded by elements such as carbon, silicon, and germanium are bonded can be exemplified.

In the case where the catalyst is melt-mixed with the copolymer, the catalyst concentration in the whole mixture is 0.01 to 100.
Generally, the concentration is about 00 ppm, preferably 0.1 to 100 ppm. When the catalyst is dissolved in a solvent and used, the solution concentration is 0.1 to 100,000.
ppm, preferably 1 to 10000 ppm. Here, as a treatment condition with the catalyst, when a catalyst dissolved in a solvent is used, it is usually from 0 ° C. to the deformation temperature of the copolymer, specifically, from 0 ° C. to 150 ° C. for several seconds to several hours. When processing at the time of processing, it is the melting temperature of the copolymer,
It is several seconds to several minutes at 50 to 300 ° C.

There is no particular limitation on the method of mixing the above components or mixing with known additives such as antioxidants, ultraviolet absorbers, lubricants, antistatic agents, and other nucleating agents that are added as necessary. After mixing the respective components with a Henschel mixer, a V-type blender or the like, they are melt-mixed with an extruder or a roll, a Banbury mixer, a kneader or the like, and granulated once to form pellets.

In the present invention, a compound containing an unsaturated bond, an inorganic filler and the like can be mixed.

[0023]

The present invention will be further described with reference to examples.

A vibration mill equipped with four crushing pots having a capacity of 4 liters and containing 9 kg of steel balls having a diameter of 12 mm is prepared. Magnesium chloride 300 in each pot under nitrogen atmosphere
g, 60 ml of tetraethoxysilane and 45 ml of α, α, α-trichlorotoluene were added and pulverized for 40 hours. 300 g of the co-ground product thus obtained was placed in a 5-liter flask, 1.5 liters of titanium tetrachloride and 1.5 liters of toluene were added, and the mixture was stirred at 100 ° C. for 30 minutes, and then the supernatant was removed. Again 1.5 liters of titanium tetrachloride and 1.5 parts of toluene
Then, the mixture was stirred at 100 ° C. for 30 minutes, and then the supernatant was removed. Thereafter, the solid content was repeatedly washed with n-hexane to obtain a transition metal catalyst slurry. When a part was sampled and analyzed for titanium content, the titanium content was 1.9 wt%.

Under an atmosphere of nitrogen, 40 ml of toluene, 100 mg of the above transition metal catalyst, 0.128 ml of diethylaluminum chloride, 0.06 ml of methyl p-toluate and 0.20 ml of triethylaluminum were put in a 5 liter autoclave, and 1.5 kg of propylene and 80 g of vinylsilane were added. Plus hydrogen
After injection of 0.5N liter, polymerization was carried out at 75 ° C for 2 hours. After the polymerization, unreacted propylene was purged, the powder was taken out, and dried by filtration to obtain 480 g of powder.

The intrinsic viscosity (hereinafter abbreviated as η) was measured with a tetralin solution at 135 ° C., and measured using a differential thermal analyzer at 10 ° C. /
The melting point and crystallization temperature were measured as the maximum peak temperature by raising or lowering the temperature by min. The obtained powder was a crystal having η of 2.35 dl / g , melting point of 156 ° C, and crystallization temperature of 120 ° C. Propylene copolymer.
According to elemental analysis, it contained 1.3 wt% of a vinylsilane unit.

To 100 g of the obtained copolymer, 5 g of divinylbenzene and 30 g of talc (CT-8 manufactured by Asada Flour Milling Co., Ltd.) were mixed and press-molded to obtain a molded product having a thickness of 1 mm. This molded product was immersed and impregnated in a toluene solution of bispentamethylcyclopentadienyl ytterbium hydride dissolved at 10 g / liter and treated at 80 ° C. for 2 hours.
The molded product did not deform at all even at 200 ° C., and the proportion of the residue extracted with boiling xylene for 12 hours was 96%. The following physical properties of the molded product were measured. Flexural rigidity: kg / cm ² ASTM D747 (23 ° C) Tensile yield strength: kg / cm ² ASTM D638 (23 ° C) Izod (with notch) Impact strength: kgcm / cm ASTM D256 (20 ° C, -10 ° C) Flexural rigidity 19,600 kg / cm ² , tensile yield strength 408 kg / cm ²
And Izod impact strength were 7.2 kg / cm / cm 2 respectively.

Comparative Example 1 The same procedure as in Example 1 was carried out except that the treatment was not carried out with bispentamethylcyclopentadienyl ytterbium hydride. The proportion of the residue extracted with boiling xylene for 12 hours was 0, The molded product has a flexural rigidity of 17400 kg / cm.
² , tensile yield strength was 385 kg / cm ² , and Izod impact strength was ⁵ , ² kg · cm / cm, respectively.

Example 2 A propylene copolymer having an allylsilane content of 0.25 wt% was produced by polymerization in the same manner as in Example 1 except that 1 g of allylsilane was used instead of vinylsilane. Η of the copolymer is 1.85 dl
/ G , melting point: 158 ° C., crystallization temperature: 115 ° C., extraction ratio with boiling n-heptane for 6 hours was 96.8%.

Example 1 except that 100 g of this powder was used.
A molded article was prepared in the same manner as described above, and treated in the same manner as in Example 1 except that bispentamethylcyclopentadienyl ruthenium hydride was used as a catalyst. The physical properties of the molded article were as follows. The flexural rigidity was 19700 kg / cm ² , the tensile yield strength was 395 kg / cm ² , and the Izod impact strength was 9, 2 kg · cm / cm. In addition, the molded product did not deform at 200 ° C at all, the ratio of the extraction residue extracted with boiling xylene for 12 hours was 94%, and the weight increase of the molded product after extraction was 35%
It was only.

[0031]

According to the present invention, a heat-resistant crosslinked polyolefin can be easily obtained by carrying out the method of the present invention, which is extremely valuable industrially.

Claims (1)

(57) [Claims] A method for producing a crosslinked polyolefin by treating a copolymer of an alkenylsilane and an olefin or a mixture of a copolymer of an alkenylsilane and an olefin and a polyolefin with a catalyst, wherein a cyclopentadienyl lanthanide metal is used as a catalyst. A method for producing a crosslinked polyolefin, comprising using a complex.