CA2125959C

CA2125959C - Bis(diallylamino) silanes

Info

Publication number: CA2125959C
Application number: CA002125959A
Authority: CA
Inventors: Steven E. Mulhall
Original assignee: Aristech Chemical Corp
Current assignee: Braskem America Inc
Priority date: 1992-10-23
Filing date: 1993-10-21
Publication date: 2000-02-22
Anticipated expiration: 2013-10-21
Also published as: WO1994010217A1; EP0620831A1; CA2125959A1; EP0620831A4; JPH07502565A

Abstract

Bis(diallylamino) silanes of formula (I) where R1 and R2 are lower alkyl or phenyl groups are copolymerized with lower olefins and desilylated to exhibit amine functionality; they are receptive to dyes.

Description

BIS(DIALLYLAMINU) SILANES
Technical Field.
This invention relates to the use of bis(diallylamino) silanes of the general formula (CH2=CH-CH2)2N-Si-N(CH2-CH=CH2)2 where R1 and R2 are independently selected from alkyl and aryl groups having 1 to 6 carbon atoms as comonomers for lower olefins polymerized in highly active Ziegler-Natta catalyst systems.
Background Art In European Patent Publication 0423438, Sivak et al propose the use of protected diallyl amine monomers for copolymerization with ethylene, propylene, and other lower alpha-olefins having up to 8 carbon atoms. Protection of the otherwise vulnerable amine group is provided by a silyl group 2125J5~!

having relatively bulky,substituents, such as lower alkyl or phenyl groups. Diallyl amines are proposed and several examples are given of silyl-protected diallyl amines. However, bis-diallyl amines are not contemplated.
Summary of Invention I have invented new compounds of the general formula (CH2=CH-CH2)2N-Si-N(CH2-CH=CH2)2 where R1 and R2 are independently selected from alkyl and aryl groups having 1 to 6 carbon atoms.
They may be used as cross-linking agents in polymers and find special utility as comonomers for lower olefins polymerized in highly active Ziegler-Natta catalyst systems.
Detailed Description cf the Invention My invention will be described with respect to two paradigms, namely bis(diallylamino)dimethylsilane and bis(diallylamino)diphenylsilane.

- ~ ~ ~ PCT/US93/10025 EXAMPLE I
Bis(diallylaminoldimethylsilane The equipment used for the synthesis of bis(diallylamino)dimethylsilane was set up in the following manner. A reflux condenser, mechanical stirrer and 125 ml addition funnel were placed on a 2000 ml 3-necked, round-bottomed flask. An argon inlet was connected to the top of the reflux condenser and a heating mantle was placed on the flask. The flask was flushed with argon (allowing the argon to exit the setup through the top of the addition funnel) until the atmosphere in the glassware was assured of being inert.
Heptane (400 ml), triethylamine (136.62 g, 1.350 moles, 188 ml) and diallylamine (98.36 g, 1.012 moles, 125 ml) were charged into the reaction flask. Dichlorodimethylsilane (43.55 g, 0.3375 moles, 41 ml) was placed in the addition funnel and added to the reaction mixture in the flask over a period of 70 minutes. The temperature of the reaction mixture reached 37.5°C (as measured by a thermocouple between the flask and heating mantle).
The reaction produces a large amount of salts (triethylamine hydrochloride and diallylamine hydrochloride) and twice during the reaction additional heptane had to be added (200 ml portions each time) in order to keep the slurry thinned to a stirrable consistency.

2iy595~

After the addition of dichlorodimethyl-silane was complete, the mixture was heated to reflux for five hours. .The flask was then allowed to cool to room temperature.
The salts were removed by filtration using a buchner funnel covered with a latex dam to keep exposure to the atmosphere to a minimum. the product was isolated from the filtrate by distillation. The heptane and excess amines were removed at a vacuum of 40 mmHg with a temperature range from ambient to 93°C. The product distilled at 72.6-74.6°C at 1 mmHg.
61.2 g of bis(diallylamino)dimethylsilane was isolated by this technique which corresponds to a yield of 720 of theoretical after distillation.
EXAMPLE II
Bis(diallylamino)diphenylsilane The glassware setup used for the preparation of bis(diallylamino)diphenylsilane was the same as the equipment used for the synthesis of bis(diallylamino)dimethylsilane above except that a 1000 ml flask was used instead of a 2000 ml flask.
After the system was flushed with argon, triethylamine (159.84 g, 1.580 moles, 220.2 ml), diallylamine (84.48 g, 0.8699 moles, 107.3 ml) and toluene (200 ml) were added to the reaction flask.
Dichlorodiphenylsilane (100.75 g, 0.3980 moles, 83.7 ml) was charged into the addition funnel and added to the reaction mixture in the flask over a period of 15 minutes, the temperature rose to 60°C.

WO 94/10217 ~ 1 ~ ~ 9 ~ ~ PCT/US93/10025 A large amount of solid precipitated from the mixture. Toluene (100 ml) was added to the flask through the addition funnel to rinse out the remaining silane and make the reaction mixture more stirrable and the mixture was heated to reflux for two hours, then cooled to room temperature.
The salts were removed by filtration using a sealed pressure filter under an inert atmosphere.
The product was isolated from the filtrate by distillation. The heptane and excess amines were removed at a vacuum of 40 mmHg with a temperature range from ambient to 43°C. The product distilled in a range from 160°/0.3 mmHg to 160°/0.1 mmHg.
101.5 g of bis(diallylamino)diphenylsilane was isolated by this technique which corresponds to a yield of 68$ of theoretical after distillation.
Similar preparations may be made for the diethyl, dipropyl, dibutyl, dipentyl, dihexyl and methylphenyl variants.
My new monomers may be incorporated into chains of crystalline polypropylene and other lower olefin polymers as described in the above-mentioned Sivak et al patent. Thereafter, the silyl groups may be removed by hydrolysis or alcoholysis optionally promoted by acidic or basic catalysis and the remaining copolymers, which may be mildly cross-linked, will exhibit amine functionality or ammonium functionality in the presence of acids.
My monomers may be homopolymerized using Ziegler-Natta systems and/or copolymerized in amounts to yield copolymers having ratios of lower olefin to my monomer (m) of 0.1 mole ~ to 99.9 mole %.

Following are examples of propylene copolymerizations with bis(diallylamino)dimethylsilane ("BDMS") and bis(diallylamino)diphenylsilane ("BDPS").
_General Copolymerization Procedure Standard inert atmosphere techniques were used to exclude moisture and oxygen throughout the manipulations.
An apparatus consisting of a round bottom flask fitted with a side arm, magnetic stirring bar and a stopper was assembled hot from a drying oven and was then either evacuated and refilled with inert gas several times or (and) purged with inert gas for at least 15 minutes. The flask was charged with a given amount of solvent, heptane or toluene, usually 125 mL. The solvents were freshly distilled from sodium and triethyl-aluminum (TEA) over which they had been refluxed for at least 18 hours under an inert atmosphere.
At this point the inert gas atmosphere in the flask was replaced with the gaseous comonomer by a minimum of three cycles of evacuation and refilling back to atmospheric pressure with the comonomer. After the third cycle the solution was stirred for at least ten minutes (usually longer) to allow the solvent to become saturated with the comonomer. Pressure was maintained at one atmosphere via a bubbler.
Next was added an "external donor", which was diphenyldimethoxysilane. Phenyltrimethoxysilane may alternatively be used. Then the other comonomer 7 .-2 ~ ~ ~ 9 5 ~ P~/US93/10025 _7_ was added. A given amount of alkyl aluminum co-catalyst, which was in the form of a heptane solution of about 25$ by weight (0.715 g/mL in heptane), was also added to the flask.
The polymerization was initiated by the addition of the transition metal containing co-catalyst, which was a titanium tetrachloride on a magnesium chloride support. At this point the flask was lowered into a thermostated oil bath and magnetic stirring was begun.
An excess of gaseous comonomer was passed into the flask in order to replace any that was consumed. Excess gaseous comonomer was allowed to pass from the reaction vessel via a bubbler, maintaining a pressure in the flask of one atmosphere.
After a specified period of time the reaction was quenched by the addition of acidified alcohol (HC1 in iso-propanol, ethanol and/or methanol). The quenched reaction slurry was combined with the alcohol solution of volume at least twice the original volume of the inert reaction solvent. The resultant slurry was stirred for at least 45 minutes and then filtered. This treatment not only stopped the reaction, it dissolved catalyst residues and removed silyl groups and thus regenerated the amino groups.
If the filtration proceeded very slowly, the slurry was combined with enough water to make the filtration proceed at a convenient rate.
The polymer was resuspended in alcohol, a stirred, filtered and vacuum dried overnight.

2~2~~59 _8_ Boiling heptane soluble content was determined by standard methods.
Homopolymerization of propylene under these conditions produces polypropylene with yields in the range of 200-220 g polymer/g , titanium-containing catalyst. The extent of reduction in polymer yield in the copolymerizations relative to this homopolymer yield is used as a rough guide to the utility of the comonomers in the copolymerization systems.
Copolymerizations of Propylene with Bis(diallylamino) dimethylsilane (BDMS) Example III
The general copolymerization procedure above was followed using the following quantities of reagents and reaction conditions in the polymerization.
Solvent heptane 100 mL
External Donor DPMS 75 NL
Comonomer BDMS 3.85 g Cocatalyst triethylaluminum 4.3 mL (25 wt ~) TiCl4/MgCl2 Catalyst 91 mg Reaction Temperature 50°C
Reaction Time 2 hr Alcohol Used in Work Up iso-propanol The polymerization yielded 8.3 g of polymer which is a yield of 91.2 g polymer/g catalyst. This corresponds to about 40% of the yield of a homopolymerization of propylene under these conditions.

_g_ Example IV
This polymerization was done using the following quantities of reagents and reaction conditions with the general copol ymerization procedure from above.

Solvent heptane 75 mL

External Donor DPMS 225 NL

Comonomer BDMS 11.12 g Cocatalyst triethylaluminum 12.9 mL (25 wt ~) TiCl4/MgCl2 Catalyst 104 mg Reaction Temperature 50C

Reaction Time 2 hr Alcohol Used in Work Up iso-propanol Polymer (5.8 g) was produced in this polymerization which is a yield of 55.5 g polymer/g catalyst which is approximately 25% of a comparable homopolymerization.
Copolymerizations of Propylene with Bis(diallylamino) diphenylsilane (BDPS) Example V
The following quantities of reagents and reaction conditions were used with the general copolymerization procedure.
Solvent heptane 100 mL

External Donor DPMS 220 NL

Comonomer BDPS 18.19 g Cocatalyst triethylaluminum 12.5 mL (25 wt %) TiCl4/MgCl2 Catalyst 137 mg Reaction Temperature 50C

Reaction Time 2 hr Alcohol Used in Work Up iso-propanol ~~2~g59 The polymerization yielded 15.4 g of polymer which is a yield of 112.4 g polymer/g catalyst which is in the range of 51-57$ of a comparable propylene homopolymerization. 98.40 of a tested sample was insoluble in boiling heptane.
Example VI
The following quantities of reagents and reaction conditions were used with the general copolymerization procedure.
Solvent heptane 50 mL

External Donor DPMS 400 NL

Comonomer BDPS 31.97 g Cocatalyst triethylaluminum 23.5 mL (25 wt ~k) TiCl4/MgCl2 Catalyst 117 mg Reaction Temperature 50C

Reaction Time 2 hr Alcohol Used in Work Up iso-propanol Copolymer (17.0 g) was produced by this copolymerization which corresponds to a yield of 145.3 g polymer/g catalyst. This is about 70~ of what is produced in a comparable propylene homopolymerization.
The fraction insoluble in boiling heptane was 91.8 of the tested sample.
Uptake of an Acid Dye by Polymer Samples as a Test for Amine Incorporation Example VII
A sample of propylene homopolymer was prepared using the general polymerization conditions given above and used as a blank in the dye uptake experiments described below.
A stock solution of dye was prepared by dissolving Acid Alizarin Blue BB dye (1.00 g) and ammonium acetate (7.0 g) in water to obtain 80 grams of solution.

~~2~~5.~

Samples (200 mg) of the propylene homopolymer and each of the four propylene/amine copolymers produced iri Examples 1-4 above were placed in test tubes and 10 mL of the stock dye solution was added.
The samples were sealed and shaken to assure dispersion of the polymer powder in the dye and placed in a 60°C water bath. The temperature of the bath was increased to 100°C over a period of 30 minutes and held at that temperature for 1 hour and then cooled to room temperature.
The samples were filtered and rinsed repeatedly with water until the rinsings were clear and the color of the powder did not appear to change. The rinsings were then continued with an equivalent amount of water. The total amount of water used was about 500 ml. The samples were then suspended in boiling water for about one minute and then filtered and this hot wash was repeated two more times.
After the samples were dried, their color intensities were compared and are described in Table 1 below.

Table 1 Dyed Propylene/Amine Copolymers Sample Color Propylene homopolymer very pale pink/

purple color Example III slightly more intense purple than propylene homopolymer Example IV pale purple Example V pale purple Example VI reasonably intense purple/blue color

Claims

1. A copolymer of about 0.1% to about 99.9%
lower alpha-olefin having 2 to 8 carbon atoms and a bis(diallylamino) silane of the formula where R1 and R2 are independently selected from alkyl and aryl groups having 1 to 6 carbon atoms.

2. Copolymer of claim 1 wherein the alpha-olefin is propylene.

3. Copolymer of claim 1 wherein the silane is bis(diallylamino) dimethylsilane.

4. Copolymer of claim 1 wherein the silane is bis(diallylamino) diphenylsilane.

5. A desilanated copolymer of claim 1.

6. A desilanated copolymer of claim 2.

7. A desilanated copolymer of claim 3.

8. A desilanated copolymer of claim 4.

9. A dyed copolymer of claim 5.

10. A dyed copolymer of claim 6.

11. A dyed copolymer of claim 7.

12. A dyed copolymer of claim 8.

13. Bis(diallylamino) silanes of the formula where R1 and R2 are independently selected from alkyl and aryl groups having 1 to 6 carbon atoms.

14. A silane of claim 13 wherein R1 and R2 are CH3.

15. A silane of claim 13 wherein R1 and R2 are phenyl groups.