CS205002B2 - Process for preparing polyimine aluminium compounds - Google Patents

Abstract

1508048 Polyiminoalanes SNAMPROGETTI SpA 19 June 1975 [1 July 1974] 26213/75 Heading C3R The invention comprises a polyiminoalane having the general formula in which R is an aliphatic, aromatic or cycloaliphatic hydrocarbyl radical, H is hydride hydrogen, Y is a halogen atom, k is from 2 to 50, i is greater than zero, j # 0 and the ratios h : k and (i+j) : h are both greater than 1 : 1. The polymers are obtained by reacting an oligomer polyiminolane having one of the general formulae in which X and Y, which can be the same or different, represent hydrogen or halogen atoms directly bound to aluminium, n is an integer not more than 10, the sum (x + y) is an integer not more than 10, y is an integer of from 1 to 10, R is an aliphatic, aromatic or cycloaliphatic hydrocarbyl radical, and the number of halogen atoms in an oligomer (b) is not more than x + 2y, the rest of the moieties X and Y in the oligomer (b) up to a total of x+2y being constituted by hydride hydrogen atoms with an alkali or alkaline earth metal alanate or an aluminium hydride complex in a solvent medium. The products may be used in catalysts for the polymerization of olefinically unsaturated compounds. In examples the oligomers are reacted with lithium aluminium hydride, sodium aluminium hydride and a complex of aluminium hydride and diethyl ether; the products are used with titanium trichloride and with titanium tetrachloride to catalyse the polymerization of ethylene and of isoprene.

Description

The present invention relates to novel polyimide aluminum compounds, to a process for their preparation, as well as to processes utilizing these compounds as components of catalyst systems used in the polymerization of unsaturated materials.

From Italian Patent Specification No. 885,567 and from U.S. Pat. U.S. Patent Nos. 193,514 and 199,593 disclose the existence of aluminum derivatives of polyimine nature containing aluminum-bound halogen atoms.

Both cited above. patents refer to oligomeric N-alkyl-iminoalanes of chemical formulas (a) [AIX-NRj; optionally (b) (X-AlNR) _x (XYAl) _y (NHR) _y wherein substituents

X and Y are the same or different and denote hydride hydrogen and / or halogen atoms directly bound to aluminum, n is an integer less than or equal to 10, the sum (x + y) denotes an integer less than or equal to 10, y is an integer different from zero,

R denotes an aliphatic, aromatic or cycloaliphatic hydrocarbon characterized by a three-dimensional structure and atomic ratios X / Al ·· - 1 and · N / Al = ·· 1 for ··· (a) and (X -γ- YJ) / A1 ·> 1, and · N / Al = 1 in terms of (b).

Some of these compounds, when used as components of catalytic systems together with transition metal derivatives in the conjugated diene polymerization, allow polymerization reactions to be carried out at polymerization rates higher than those which can be This can be achieved by other catalytic systems while avoiding side reactions or cyclization of the polymer chains.

Among other things, this makes it possible to obtain polymers with reduced consumption of transition metal derivatives.

It has now been found that the above-mentioned aluminum compounds can be modified by reaction with alkali metal or alkaline earth metal alanates or aluminum hydride complexes to form new ones. aluminum derivatives having a substantially polyimine nature, and. in addition to maintaining or improving the above-mentioned polymerization conjugated characteristics. The dienes can be used as components of catalyst systems in the polymerization of other unsaturated substances, in particular ethylene and monoolefins.

Accordingly, the present invention provides a process for the preparation of polymeric polyimide aluminum compounds of the polyimine nature of the general formula

AlhíNRJkHiYj in which

R denotes a C1 to C3 aliphatic hydrocarbon radical,

H represents hydride hydrogen,

Y halogen, k is a number from 2 to 50, h / k > 1, (i + j) / h > 1, 10 and 0, characterized in that polyimide aluminum compounds having the chemical composition (a) [ AlX - NR b a (b) (X - Al NR b _x J _x Y l b (NHR) _y where '

X and Y are the same or different and denote hydride hydrogen and / or halogen atoms directly bonded to aluminum, n is an integer less than or equal to 10, y is an integer greater than zero and

R denotes the same as above, in reaction with alkali or alkaline earth metal alanates of the general formula

MejAlH + n where

Me is alkaline. an alkaline earth metal or metal and n is 1 or 2, or with aluminum hydride complexes, at. temperature from 0 to 70 ° C.

The process of the invention may be carried out by carrying out the reaction in the presence of a solvent selected from the group of ethers, hydrocarbons or mixtures thereof; . preferably the reaction is carried out. at a pressure equal to the vapor pressure of the solvent at the working temperature.

Depending on the starting material used, hydrogen evolution may occur and / or the alkali metal halide may be separated.

The reaction is readily carried out at temperatures ranging from 0 to 70 ° C and preferably at pressures equal to the vapor pressure of the solvent in which the reaction is carried out at the operating temperature.

It is possible to use solvents belonging to the class of ethers, such as, for example, dimethyl ether, diethyl ether, methyl ether, cyclic ethers, or mixtures thereof with hydrocarbons, or only hydrocarbons.

As mentioned above, the compounds of the invention are useful components of catalyst systems for the polymerization of compounds having at least olefinic unsaturation together with transition metal compounds.

They can therefore be used for the preparation of catalysts with a wide range of applications and, with respect to alkyl aluminum, with non-flammability properties in the presence of air.

Examples

1) 26 mmol of LiAlH 4 in ether solution [1 M] was added over 5 minutes to 176 mg of polyiminoalan atoms [as Al] dissolved in 300 ml of ether-heptane mixture (30% as ethyl ether) with Cl / Al = 0.26 N / Al = 0.97. The addition was carried out at 45 ° C and with stirring. These conditions were maintained for 4 hours, then the mixture was filtered through a glass frit. All operations were performed under an inert, anhydrous atmosphere. The filtrate was distilled under vacuum to 'remove added' ethyl ether and heptane. After analysis, the solution had the following composition:

A11H1.25N0.9C10.1.

2) 28 mmol of NaAlH 4 suspended in ethyl ether was added to 187 mmol of polypo for 4 hours, then cooled and filtered with a glass frit. The filtrate was distilled under vacuum to remove added ethyl ether and heptane. The solution was analyzed with the following composition:

Al = 0.95 mol / liter N = 0.82 mol / liter Cl = 0.10 mol / liter H = 1.10 mol / liter corresponding to the rough formula

Al1No.86H1.j6Clo.11.

of iminoalan (as Al) dissolved in 300 mL of ether-hexane (30% as ethyl ether) with Cl / Al = 0.26, N / Al = 0.97. The addition was carried out with stirring at 45 ° C. The mixture was maintained under these conditions for 4 hours and then filtered from sodium chloride.

The filtrate was distilled under vacuum to remove added ethyl ether and heptane. The solution had the following composition after analysis:

Al = 0.724 mol / liter N = 0.602 mol / liter Cl = 0.95 mol / liter H - 0.864 mol / liter corresponding to the coarse formula

AllNo.83Hl.19ClO.13.

3) 25 mmol of NaH was added with stirring at 45 ° C to 180 mg of polyminoalan atoms (as Al) dissolved in 300 ml of ether-heptane / Cl / Al mixture - 0.25, N / Al = 0.86. The mixture was maintained under these conditions

4) A chlorine-free, N-Al molar N / Al molar ratio of 1, containing 30.78 mg of aluminum, was mixed with an anhydrous HCl ether solution to obtain a molar205002 Al / Cl ratio of 0.165, then added 6.05 ml of 0.824 M LiAl-Hd ether solution (4.98 mmol). The mixture was stirred. 1 hour and ·. Then left to stand for 20 hours.

The LiCl was filtered off and the solution was freed from solvent by distillation under vacuum. The solid rest was longer. time · dried under vacuum at room temperature and · analyzed with the result: Al 33.25%, N 14.90%, H 14.88 meq / g corresponding to the rough formula _;

AllNo.86Hl.22.

The product obtained was soluble in aromatic and cycloaliphatic hydrocarbon solvents.

5) Ether solution of AlH 3 .Et 2 O (6.2 mmol) was added to the ether-hexane solution (30 percent) as. ethyl ether) of polyiminoalan with a molar. ratio · N / Al - = 0.99,. d / Al = 0.10 · containing 42.7 mg · aluminum atoms. During . The mixture was stirred for 4 hours. kept under stirring at boiling, then the solvent was removed under vacuum and hexane replaced with ethyl ether. As the solution was slightly cloudy, the filter was the result of the analysis:

A11No, 88ClO, O9H1.15.

Examples of polymerization: ethylene

1) A 5 L autoclave equipped with an anchor stirrer was charged with 2 L anhydrous and air-free n-heptane, then thermostatized to 90 ° C. A side prepared catalyst consisting of 1.00 g of TiCl.sub.AA corresponding to 2.5 mg / L and 1.27 g of polyiminoalanine (PIAPE) synthesized according to any of the above-mentioned instructions, corresponding to 7.5 mg / L of M + was added. Hydrogen was supplied as a molecular weight regulator under a pressure of 0.3 MPa, then ethylene was fed until a total pressure of 0.5 MPa was reached and the pressure was maintained at this value during the polymerization reaction itself. After two hours of reaction, the autoclave was opened, the suspension centrifuged and the polymer dried under vacuum at 60 ° C. 750 g of polymer with a density (d) of 0.958 g / cm ³ and a flow index · (IT) of 0.720 g / 10 min were obtained. A polymerization test carried out under the same conditions using polyiminoalan with N / Al = 1 according to Italian patent 885 567 gave 250 g of polymer with IT = 0.70 g / 10 min.

2) Proceed as in the previous example, using a pressure of 0.5 MPa of hydrogen. 550 g of polymer with IT = 3.60 g / 10 min were obtained.

Example of polymerization: isoprene

1) 90 ml of anhydrous and air-free hexane, 1.82. 10 ~ ³ moles of TiCU and PiAPE in an amount to achieve a ratio

Al / Ti: 0.95; 1; 1.05; 1.1 and 1.2 were filled into a series of bottles. These were sealed and the catalyst was shaken; 30 ml of anhydrous, freshly distilled isoprene was then added: The bottles were sealed with crown caps and placed in a thermostat at 30 ° C. All operations were carried out under an inert atmosphere. After two hours of polymerization, the reaction was quenched with ethanol and coagulated with ethanol. After drying, the following were obtained, ^kohverse:;

Al / Ti Conversion ..% g · as dry polymer · ·

1.00 35 1.05 90 1.10 60 1.20 Ί5

A comparative polymerization series performed further using PIA according to Italian patent 885,567 gave the following results:

Al / Ti conversion ° / o · g · as dry polymer

1.0025

1,0586

1.1075

1,2052

The polyisoprene obtained had a 1.4 cis content of greater than 95%.

Examples of copolymerization: monoolefins

1) A 5 L autoclave equipped with an anchor stirrer was charged with 2 L of anhydrous and air-free n-heptane containing 15 g of anhydrous and air-free hexene-1; was thermostatized to 85 ° C, then a preformed catalyst was charged, consisting of 1.00 g of TiCl 2 AA corresponding to 2.5 milligrams / Htr and 0.9 g of polyinpinoalan (PIAPE) corresponding to 5 milligrams / h of: r M +.

Hydrogen was supplied as a molecular weight regulator at a pressure of 0.2 MPa, then ethylene was fed up to a total pressure of 0.5 MPa, and this value was maintained by ethylene feed, controlled by the polymerization reaction itself. After two hours of polymerization, during which 20 grams of hexene-1 was introduced, the reaction was quenched with 250 ml of ethanol, which also solubilized the catalyst. The suspension was centrifuged and the polymer was dried under vacuum.

620 g of a copolymer with an ash content of 300 ppm were obtained, d = 0.947 g / cm ³ ,

IT = 0.20 g / 10 min, resistance to stress splitting, external effects> 430 hours.

Claims (3)

PREDMBT CLAIMS 1. A process for the production of polymeric aluminum compounds of the polyimine nature of the general formula:. . , · · AMNRhHYj ve. .. which R denotes C1-C3 - an aliphatic hydrocarbon radical, H represents hydride hydrogen, Y halogen, k · is a number from 2 to 50, h / k> 1, (i + n / h> 1, i # 0 and z 0), characterized in that aluminum compounds of polyimine nature with chemical composition (a) - (AlX — NR] _n —a (b) - (X — A1NR) x (XYAlj _y (.NHR) y where ............... ....... ... invented, u X and Y are the same, or. different and denote hydride hydrogen, and / or halogen atoms directly bonded to aluminum, n is an integer less than or equal to 10, y is an integer greater than zero, and R denotes the same as above, in reaction with alkali or alkaline earth metal alanates of the general formula MeiAlHb where Me is an alkaline or alkaline earth metal and n. is 1 - or 2, or - with an aluminum hydride. complexes, at a temperature of from 0 to. - 70 ° C. 2. The method according to - point. 1, characterized in that the reaction is carried out in the presence of a solvent selected from the group. ethers, hydrocarbons or mixtures thereof. ........ Process according to any one of the preceding claims, characterized in that the reaction is carried out at a pressure equal to the vapor pressure of the solvent at the operating temperature.