JPS5912684B2 - Method for producing highly crystalline olefin polymer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for polymerizing olefins to obtain highly stereoregular olefin polymers.

5 Conventional transition metal compounds of groups ■~■ of the periodic table and 1~■
It is known that olefin polymers can be obtained in high yields with Ziegler-Natsuta catalysts consisting of group metals or combinations of metal hydrides or organometallic compounds.

10 At this time, an amorphous polymer is produced as a by-product in addition to the crystalline polymer.

In such polymerization methods, the issues are the catalytic activity and the stereoregularity yield expressed in terms of the weight of the catalyst and the amount of polymer produced per unit time.

15 Catalytic activity is a problem because it affects the productivity of the polymer, and furthermore, the residual catalyst residue in the obtained polymer has various effects on the stability, weather resistance, coloration, etc. of the olefin polymer. This is to cause problems.

20. Stereoregularity is a problem because it greatly affects the mechanical properties and processability when the polymer is processed into films, fibers, and other molded products.

For example, polypropylene is widely used in films.

In this case, if the polypropylene produced as a product has low stereoregularity, it causes the so-called blocking phenomenon in which the films stick together, which is extremely disadvantageous from a practical point of view. 30 According to the studies conducted by the present inventors, there is a linear relationship between blocking and the cold xylene soluble area at 20°C, which is a measure of stereoregularity, as shown in Figure 1. Value is 30g/10
Therefore, it is necessary that the cold xylene soluble portion be 3% or less.

The reason for using the cold xylene soluble portion as a measure of stereoregularity here is that in the conventionally widely used boiling heptane extraction residue, there is a correspondence between blocking and boiling heptane extraction residue depending on the polymer sample. This is because it does not necessarily hold true. As a method to increase the catalytic activity, β-type titanium trichloride is treated with a complexing agent and then treated with titanium tetrachloride (Japanese Patent Application Laid-open No. 1983-34478), β-type titanium trichloride is treated with a complexing agent. Furthermore, the general formula R2nAeX3-
0 (R2 is a linear or branched alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group, or an aromatic hydrocarbon group, and
represents halogen.

There is also a method of treating with an organoaluminum compound where O<n<1.5) and further treating with a complexing agent. Although the above treatment dramatically increases the catalytic activity, it is inferior in terms of the cold xylene soluble portion.

As a result of extensive studies, the inventors of the present invention have found that when olefin polymerization is carried out using a catalyst obtained by the treatment described below, the stereoregularity of the resulting polymer is improved and blocking is improved. We have arrived at the present invention.

The present invention uses titanium tetrachloride with the general formula RnAlX3-o (R is a linear alkyl group having 1 to 18 carbon atoms, a branched alkyl group, an alicyclic hydrocarbon group, or an aromatic hydrocarbon group, and X is a halogen represents.

Further, the β-type titanium trichloride obtained by reduction with an organoaluminum compound of 1≦n≦3) is treated with a complexing agent, and then the thus treated solid catalyst is treated with titanium tetrachloride, and further amine, phosphine, Phosphoric triamide, phosphite, ether, ester, urea derivative, amide,
It is characterized by polymerizing olefins using a catalyst system consisting of a catalyst obtained by treatment with a Lewis base selected from thioether, thiourea, and thiophenol (excluding siloxane polymers) and an organoaluminum compound. The present invention relates to a method for producing a highly crystalline olefin polymer. The present invention will be explained in detail below using the general formula RnAeX3- used in the production of β-type titanium trichloride.

Specific examples of organoaluminum compounds represented by are methylaluminum dichloride, ethylaluminum dichloride, n-propylaluminum dichloride, methylaluminum sesquichloride, ethylaluminum sesquichloride, dimethylaluminum chloride, diethylaluminum chloride, di-n-propylaluminum chloride. , trimethylaluminum, triethylaluminum, triisobutylaluminum, etc., but the properties are not limited to the above compounds. The reduction reaction to obtain β-type titanium trichloride is -100
It is carried out at a temperature between -60°C, preferably between -30 and 30°C.

Further, the reduction reaction is preferably carried out by diluting with an inert solvent such as hexane, heptane, octane or decane.

Complexing agents for β-type titanium trichloride include alcohols, aldehydes, acids, acid anhydrides, ketones, esters, amides,
imide, ether, thioether, nitrile, amine,
It can be arbitrarily selected from compounds such as lactams and phosphoric acid amides, among which compounds selected from the group of amides, ethers, thioethers, and amines give preferable results.

Specific examples include N,N-dimethylformamide, N,N
-dimethylacetamide, N,N-dimethylpropionic acid amide, N,N,N2,N2-tetramethylurea, diethyl ether, di-n-propyl ether, diisopropyl ether, di-n-butyl ether, diisobutyl ether, ditertiary Butyl ether, di-n-amyl ether, diisoamyl ether, dineobentyl ether, di-n-hexyl ether, di-n-octyl ether, diphenyl ether, di-0-tolyl ether,
di-p-tolyl ether, synchronohexyl ether,
Diethyl sulfide, di-n-propyl sulfide, di-n-butyl sulfide, di-tert-butyl sulfide, diphenyl sulfide, trimethylamine, triethylamine, tri-n-butylamine, triphenylamine, pyridine, quinoline, Sym-triazine,
Examples include compounds such as N,N-dimethylaniline, N,N-diethylaniline, and N,N,N',N'-tetramethylethylenediamine, but the properties are not limited to the above compounds.

The treatment of titanium trichloride in the beta form with a complexing agent is advantageously carried out in the presence of a diluent. The amount of complexing agent to be used is preferably 0.05 to 3 mol per mol of titanium trichloride.
．． The amount is 5 to 1.5 moles.

The treatment temperature is preferably between 0 and 100°C.

The complexing agent treated solid is then treated with titanium tetrachloride. The treatment is advantageously carried out in the presence of diluents such as hexane, heptane, octane, decane, decalin, cyclohexane.

Processing temperature is -30~+100℃, preferably 40~80℃
It is carried out at a temperature of

The solid catalyst is then treated with amines, phosphines, phosphoric triamides, phosphites, ethers, esters,
Treat with a Lewis base selected from urea derivatives, amides, thioethers, thioureas, and thiophenols (excluding siloxane polymers).

It is desirable that the Lewis base has a structure that does not have active hydrogen as much as possible.

Specifically, triethylamine.

-Butylamine, N,N-dimethylaniline, N,N diethylaniline, pyridine, S-triazine, hexamethylenetetramine, triethylphosphine, triphenylphosphine, triethylphosphite, hexamethylphosphoric triamide, diphenyl ether , ethyl acetate, ethyl benzoate, methyl methacrylate, tetramethyl urea, N,N-dimethylacetamide, diethyl sulfide, di-n-butyl sulfide, di-tert-butyl sulfide, thiophene, carbon disulfide, tetramethyl thiourea , tetramethylthiuram monosulfide, thiophenol, etc., but they are not limited to the above compounds. In addition, if the amount of Lewis base relative to the solid catalyst in the treatment exceeds 30 mol %, the activity of the catalyst will be reduced. If it is less than 0.1 mol%, the effect of improving stereoregularity is small;
It is desirable to treat the amount between 1.0 and 10 mol %, more preferably between 1.0 and 10 mol %.

The treatment is advantageously carried out in the presence of diluents such as hexane, heptane, octane, decane, decalin, cyclohexane.

The treatment temperature is preferably between 0° C. and 80° C., and the treatment time is not particularly limited, but a time of 5 minutes to 3 hours is usually advantageous.

Through the above steps, a solid catalyst that provides an olefin polymer with high stereoregularity is obtained.

In the present invention, dialkylaluminum halides are preferred as organoaluminum compounds used in combination with the above solid catalyst in the polymerization of olefins, and diethylaluminum chloride is particularly preferably used.

In the polymerization of olefin, the molar ratio of the solid catalyst to the organoaluminum compound can be selected from a wide range, such as from 10:1 to 1:200, and preferably from 2:1 to 1:200.

The catalyst concentration is very dilute, for example 0.1 mmol/
You can choose from a wide range of options, from e to use without dilution at all.

Polymerization can be carried out over a temperature range from -50°C to 200°C, but temperatures below 0°C result in a decrease in the polymerization rate, and temperatures below 100°C result in highly stereoregular polymers. It is usually preferable to carry out the reaction at a temperature in the range of 0 to 100° C. due to reasons such as the inability to obtain

There are no particular restrictions on the polymerization pressure, but a pressure of about 1 to 100 atm is desirable from the viewpoint of industrial and economical considerations.

Further, the polymerization method can be either continuous or batchwise.

The olefin to which the present invention can be applied is α having 2 to 15 carbon atoms.
- It is an olefin and may be linear or branched.

Furthermore, it may be an olefin having an aromatic hydrocarbon group or an alicyclic hydrocarbon group. Specific examples include ethylene, propylene, butene-1, benzene-1, hexene-1, octene-1, decene-1,3-methylbenzene-1,4-methylbenzene, and styrene. It is not a property that should be limited to compounds.

The polymerization according to the present invention can be either homopolymerization or copolymerization.

During copolymerization, a copolymer can be obtained by bringing a mixture of two or more types of olefin into contact with a catalyst.

At this time, in order to obtain a polymer having a high degree of stereoregularity, it is desirable that the mixing ratio of the two types of olefins is 10 mol % or less for one of them.

In addition, zero block copolymerization can be easily carried out in which polymerization is carried out in two or more stages. As the polymerization method, slurry polymerization using an inert solvent such as hexane, heptane, octane, or decalin, or polymerization without a solvent is also possible.

Gas phase polymerization is also possible. The method of the present invention will be explained below with reference to Examples, but the present invention should not be limited to these Examples in any way.

Example 1 Catalyst Preparation Method a (Production of β-type Titanium Trichloride) After purging the reaction vessel of 1e with argon, 200 CC of dry hexane and 50 CC of titanium tetrachloride were added, and the solution was maintained at -5°C.

Then, a solution consisting of 1501 cc of dry hexane and 58 cc of diethylaluminum chloride is added dropwise under conditions such that the temperature of the reaction system is maintained at -3 DEG C. or lower. After completing the dripping, add 3 more
Stirring was continued for 0 minutes, then the temperature was raised to 70°C, and stirring was continued for an additional hour.

After standing still, the supernatant liquid was extracted and diluted with 150cc hexane.
70f after washing twice! β-type titanium trichloride was obtained. The titanium trichloride contains 4.53% by weight Al.

Catalyst preparation method b (complexing agent treatment of β-type titanium trichloride) 67 g of β-type titanium trichloride was suspended in 5001 dry hexane, and 58.0 CC of di-n-butyl ether was added to this suspension.
((NBu)20/TiCl3=1.0),
Stir at 0°C for 1 hour.

After the reaction is completed, the soil clear solution is extracted, further washed three times with 1501 hexane, and dried.

Catalyst preparation method c (TiCl4 treatment) Solid catalyst obtained by complexing agent treatment 50f! is suspended in a solution consisting of 100 CC of titanium tetrachloride and 150 CC of hexane, and stirred at 70°C for 3 hours.

After the reaction is completed, the supernatant liquid is taken out, washed three times with 2001 hexane, and dried.

The catalyst thus obtained is called a titanium tetrachloride treated catalyst.
Catalyst preparation method d (Lewis base treatment) Catalyst 20.29 obtained by titanium tetrachloride treatment was heated at 100C.
C was suspended in hexane, 0.561 g of ethyl benzoate was added, and the mixture was reacted at 60° C. for 1 hour.

After the reaction was completed, it was cooled to room temperature and the supernatant liquid was extracted.
Wash three times with 1001 hexane and dry. The catalyst thus obtained is referred to as a solid catalyst (1). Polymerization method of propylene 1 A stirred stainless steel autoclave with an internal volume of 51 was replaced with nitrogen, and 1.5e of dry heptane and 4.5f of diethylaluminum chloride were added! , solid catalyst (1) 215mfI
and hydrogen corresponding to a partial pressure of 0.16 Kf/Crl is added.

Then, after raising the temperature inside the autoclave to 70°C, propylene was pressurized to 6Kf/CTl (gauge pressure).
Polymerization was continued while supplying propylene to maintain this pressure.

After 4 hours, monomer introduction was stopped, the propylene gas was purged, and 100 cc of butanol was added to decompose the catalyst.

The produced polymer was separated at Buchna Ichito, and heptane 50
Washed 3 times at 0CC and dried under reduced pressure at 60℃.5
009 polypropylene was obtained.

Heptane was distilled off from the bottom liquid by steam distillation, and a small amount of by-product amorphous polymer was recovered. The polymerization activity of the solid catalyst (1) was 580 when expressed as polymer yield Rp (g polymer/GTice3·Hr) per GTiCl3·1 hour.

Further, the cold xylene soluble portion obtained by dissolving the entire polymer in boiling xylene and cooling it was as small as 1.5%, and was highly stereoregular.

The bulk specific gravity of the polymer is 0.42, and Tetralin 135
The intrinsic viscosity [η] at °C was 2.15.

Polymerization method 2 A stirred stainless steel autoclave with an internal volume of 5e was purged with nitrogen, and diethylaluminum chloride 4.59,
Charge solid catalyst (1) 86.5η, 0.53Kf/d
Add hydrogen corresponding to the partial pressure, then add liquid propylene 1
．． 4Kf7 was pressurized into the autoclave and the reactor was heated to 70℃.
Polymerization was continued for 4 hours while maintaining the temperature at

After completion of polymerization, purge unreacted gas and add methanol 100
CC was added to decompose the catalyst. The produced polypropylene was separated using a Buchna Isseito, washed three times with 500cc heptane, and dried under reduced pressure at 60°C. of polypropylene was obtained.

The polymerization activity of the solid catalyst (1) was 2110 when expressed in Rp.

Furthermore, the cold xylene soluble portion in the entire polymer was as low as 2.7%, and was highly stereoregular. Polymerization method Heptane 1001 was charged into a 32001 autoclave with a stirrer, and then 4.5 g of solid catalyst (1) heptane slurry 1e and a heptane solution 1 of diethylaluminium chloride 1209 were added.
．． After supplying 5e and further introducing hydrogen so that the gas phase concentration of hydrogen during polymerization was 2%, the temperature was set to 70° C., the propylene pressure was set to 6 K'/Crl (gauge pressure), and polymerization was started.

Polymerization was carried out for 8 hours while keeping the temperature, hydrogen concentration, and total pressure constant. After the polymerization was completed, unreacted propylene was purged, 52 butanol was added, and after stirring for 1 hour, solid-liquid separation was carried out.
The obtained polymer cake was washed with water and dried.

The total amount of polymer produced was 19.6K2, and the solid catalyst (1)
The Rp was 545.

The cold xylene soluble portion in the polymer was 1.6%. The bulk specific gravity of the polymer is 0.46, and Tetralin 135
The intrinsic viscosity [η] at °C was 2.11. Next, the obtained polymer was processed into a film and the blocking was measured, and it was found to be 20 in grams per 100 d.

Polymerization method 4 Solid catalyst (1) 1 in a 200e autoclave with a stirrer
．． 25f! , diethylaluminum chloride 409 was added, and hydrogen was introduced so that the gas phase concentration of hydrogen during polymerization was 6v01%.

Then, 65Kf of liquefied propylene was injected and the temperature was lowered to 70℃.
Polymerization was continued for 8 hours.

After the polymerization was completed, the resulting polymer slurry was introduced into a flash drum through a pressure reducing valve, where unreacted monomers were vaporized to obtain a powdery polymer of 22.0 Kf.

The polymerization activity of the catalyst was Rp=2200, and the cold xylene soluble portion in the total polymer was 2.7%. The bulk specific gravity of the polymer was 0.44, and the intrinsic viscosity [η] of tetralin at 135° C. was 2.00. Next, when the obtained polymer was processed into a film and the blocking was measured, it was 10
It was 28 per 1 ton of Cr. Comparative Example 1 Propylene polymerization was carried out under the same conditions as in Example 1 and Polymerization Method 4, except that the solid catalyst (1) was replaced with a titanium tetrachloride-treated catalyst.

The polymerization activity was Rp=2050, and the cold xylene soluble portion in the total polymer was 6.0%. Moreover, the intrinsic viscosity [η] of the polymer at 135° C. of tetralin was 2.30.
Next, the blocking was measured according to propylene polymerization 3 of Example 1 and found to be 97.

It is clear from Example 1 and Comparative Example 1 that the treatment according to the present invention significantly increased stereoregularity and improved blocking. Examples 2 to 6 Solid catalyst (1) was synthesized under the same conditions as in Example 1 except that the type and amount of the complexing agent were changed in the complexing agent treatment step,
Polymerization of propylene was carried out in accordance with Polymerization Method 1 in Example 1.

The results obtained are shown in Table 1. Examples 7 to 13 Solid catalyst (1) was synthesized under the same conditions as in Example 1 except that the type and amount of Lewis base were changed when treating the titanium tetrachloride-treated catalyst with Lewis base. Polymerization of propylene was carried out according to Polymerization Method 1.

Claims (1)

[Claims] 1. Titanium tetrachloride has the general formula RnAlX_3_-_n(R
is an alkyl group, a branched alkyl group, an alicyclic hydrocarbon group or an aromatic hydrocarbon group having 1 to 18 carbon atoms, and X represents a halogen. In addition, the β-type titanium trichloride obtained by reduction with an organoaluminum compound of 1≦n≦3) is treated with a complexing agent, and the thus treated solid is then treated with titanium tetrachloride, and further treated with amine, phosphine, phosphine, etc. A catalyst system consisting of an organoaluminium compound and a catalyst obtained by treatment with a Lewis base selected from orycturiamide, phosphite, ether, ester, urea derivative, amide, thioether, thiourea, and thiophenol is used. A method for producing a highly crystalline olefin polymer, comprising polymerizing an olefin.