Process to prepare aluminoxanes

Abstract

The present invention relates to a process to prepare alkylaluminoxanes by reaction of alkylaluminium with methacrylic acid or a conjugated unsaturated carbonyl-functional compound of the formula (I) wherein each R1 and R2 independently are an aliphatic hydrocarbon group, and R3 independently is the same hydrocarbon group as R1 and R2 or a hydrogen atom, and R4 isanaliphatic hydrocarbon group, a hydroxyl group or a hydrogen atom in the presence of an inert organic solvent. Additionally, it relates to the alkylaluminoxanes obtainable by the above process and their use. ##STR00001##

Claims

1. Process to prepare alkylaluminoxanes by reaction of alkylaluminium with methacrylic acid or a conjugated unsaturated carbonyl-functional compound of the formula (I) ##STR00005## wherein each R1 and R2 independently are an aliphatic hydrocarbon group, and R3 independently is a hydrocarbon group like R1 and R2 or a hydrogen atom, and R4 is an aliphatic hydrocarbon group, a hydrogen atom or a hydroxyl group in a ratio of 0.1 to 0.8 molar equivalent oxygen atoms in the part CO(R4) of the methacrylic acid or conjugated unsaturated carbonyl-functional compound to 1 equivalent of aluminium atoms in the alkylaluminium reactant, and in the presence of an inert organic solvent.

2. Process of claim 1 wherein each R1 and R2 independently are a branched or unbranched aliphatic alkyl or alkylene group of up to 20 carbon atoms, and wherein R3 independently is a branched or unbranched aliphatic alkyl or alkylene group of up to 20 carbon atoms or a hydrogen atom, and R4 independently is a branched or unbranched aliphatic alkyl or alkylene group of up to 20 carbon atoms, a hydrogen atom, or a hydroxyl group.

3. Process of claim 1 wherein methacrylic acid or one of the conjugated unsaturated carbonyl-functional compounds from the group of 3-methyl-2-butenoic acid, 2-methyl-2-propenoic acid, 4-methyl-3-pentene-2-one, 3-methyl-2-butenal is used.

4. Process of claim 1 wherein the alkylaluminium is a trialkylaluminium wherein the alkyl groups are alkyl groups of up to 8 carbon atoms.

5. Process of claim 4 wherein one or more of the alkyl groups on the alkylaluminium are selected from the group consisting of isobutyl, ethyl and methyl either individually or in combinations thereof.

6. Process of claim 1 wherein the alkylaluminium is a compound wherein at least 50% of the alkyl groups are methyl.

7. Process of claim 1 wherein the alkylaluminium contains trimethylaluminium.

8. Process of claim 1 wherein the organic solvent is selected from the group consisting of alkanes and aromatics, either individually or in combinations thereof.

9. Process of claim 1 wherein the reaction of alkylaluminium with a methacrylic acid or conjugated unsaturated carbonyl-functional compound is performed in the presence of an aluminoxane.

10. Process of claim 1 wherein the inert organic solvent contains a carrier.

11. Process of claim 10 wherein the carrier is selected from the group consisting of silica, magnesia, titania, zirconia, montmorillonite, phyllosilicate, alumina, silica-alumina, silica-chromium, silica-titania, magnesium chloride, graphite, and combinations thereof.

12. Process of claim 1 wherein the organic solvent is an alkane selected from the group consisting of heptanes and hexanes either individually or in combinations thereof.

13. Process of claim 1 wherein the organic solvent is an aromatic selected from the group consisting of toluene, xylene, ethylbenzene, cumene and mesitylene either individually or in combinations thereof.

Description

EXAMPLES

Comparative Example 1

(1) Benzophenone as Reactant

(2) A 10 ml glass vial equipped with a magnetic stirring bar was charged with 0.8 g toluene and 0.36 g (5.0 mmol) trimethylaluminium (ex AkzoNobel). To this solution, 0.64 g (3.5 mmol) of benzophenone (ex Sigma-Aldrich) dissolved in 0.5 g toluene was slowly added, resulting in an exothermic reaction with gas formation.

(3) .sup.1H-NMR analysis of the reaction product after dosing showed multiple peaks in the Al-Me region, which is indicative of the presence of intermediate products. The reaction mixture was left to stir at room temperature for 20 hours.

(4) The mixture was then heated to 105 C. (oil bath) for 1 hour.

(5) .sup.1H-NMR analysis showed no significant changes in the composition of the reaction mixture. No formation of aluminoxanes was observed. Even after 16 hours at 105 C. no PMAO was formed.

Comparative Example 2

3-buten-2-one as Reactant

(6) A 30 ml glass vial equipped with a magnetic stirring bar was charged with 8.5 g toluene and 2.7 g (37.5 mmol) trimethylaluminium (ex AkzoNobel). To this solution, 1.05 g (15.0 mmol) of 3-buten-2-one (ex Sigma-Aldrich) was slowly added, resulting in an exothermic reaction with gas formation.

(7) .sup.1H-NMR analysis of the reaction product after dosing showed multiple peaks in the Al-Me region, which is indicative of the presence of intermediate products. The reaction mixture was left to stir at room temperature for 20 hours.

(8) The mixture was then heated to 105 C. (oil bath) for 4 hours.

(9) .sup.1H-NMR analysis showed no significant changes in the composition of the reaction mixture. No formation of aluminoxanes was observed.

Comparative Example 3

(10) Acetic Acid as Reactant

(11) A 700 ml glass reactor equipped with a mechanical stirrer was charged with 639 g toluene and 25.2 g (0.35 mol) trimethylaluminium (ex AkzoNobel). To this solution, 6.3 g (0.105 mol) of acetic acid (ex Sigma-Aldrich) was slowly dosed, resulting in an exothermic reaction with gas formation.

(12) The mixture was then heated to 105 C. (oil heater/circulator), while monitoring the conversion. After 15 hours at this temperature the conversion was 50% and the aluminoxane turned into a gel.

Comparative Example 4

(13) Acetic Acid as Reactant

(14) A 700 ml glass reactor equipped with a mechanical stirrer was charged with 664 g toluene and 25.2 g (0.35 mol) trimethylaluminium (ex AkzoNobel). To this solution, 2.1 g (35 mmol) of acetic acid (ex Sigma-Aldrich) was slowly dosed, resulting in an exothermic reaction with gas formation.

(15) .sup.1H-NMR analysis of the reaction product after dosing showed multiple peaks in the Al-Me region, which is indicative of the presence of intermediate products. The mixture was then heated to 105 C. (oil heater/circulator) for 4 hours.

(16) .sup.1H-NMR analysis showed no significant changes in the composition of the reaction mixture. No formation of aluminoxanes was observed.

Example 5

3-methyl-2-butenoic Acid as Reactant

(17) A 10 ml glass vial equipped with a magnetic stirring bar was charged with 1.3 g toluene and 0.36 g (5.0 mmol) trimethylaluminium (ex AkzoNobel). To this solution, 0.18 g (1.8 mmol) of 3-methyl-2-butenoic acid (ex Sigma-Aldrich) was slowly added, resulting in an exothermic reaction with gas formation.

(18) .sup.1H-NMR analysis of the reaction product after dosing showed multiple peaks in the Al-Me region, which is indicative of the presence of intermediate products. The reaction mixture was left to stir at room temperature for 20 hours.

(19) The mixture was then heated to 105 C. (oil bath) for 1 hour.

(20) .sup.1H-NMR analysis showed that the intermediate peaks disappeared and showed the formation of a broad signal next to the TMAL peak, confirming methylaluminoxane formation.

Example 6

2-methylpropenoic Acid (Methacrylic Acid) as Reactant

(21) A 30 ml glass vial equipped with a magnetic stirring bar was charged with 8.5 g toluene and 2.70 g (37.5 mmol) trimethylaluminium (ex AkzoNobel). To this solution, 0.65 g (7.5 mmol) of 2-methylpropenoic acid (ex Sigma-Aldrich) was slowly added, resulting in an exothermic reaction with gas formation.

(22) .sup.1H-NMR analysis of the reaction product after dosing showed multiple peaks in the Al-Me region, which is indicative of the presence of intermediate products. The reaction mixture was left to stir at room temperature for 20 hours.

(23) The mixture was then heated to 105 C. (oil bath) for 1 hour.

(24) .sup.1H-NMR analysis showed that the intermediate peaks disappeared and showed the formation of a broad signal next to the TMAL peak, confirming methylaluminoxane formation.

Example 7

3-methyl-2-butenal as Reactant

(25) A 10 ml glass vial equipped with a magnetic stirring bar was charged with 1.3 g toluene and 0.36 g (5.0 mmol) trimethylaluminium (ex AkzoNobel). To this solution, 0.29 g (3.5 mmol) of 3-methyl-2-butenal (ex Sigma-Aldrich) was slowly added, resulting in an exothermic reaction with gas formation.

(26) .sup.1H-NMR analysis of the reaction product after dosing showed lots of small peaks in the Al-Me region, which is indicative of the presence of intermediate products. The reaction mixture was left to stir at room temperature for 20 hours.

(27) The mixture was then heated to 105 C. (oil bath) for 1 hour.

(28) .sup.1H-NMR analysis showed that the small intermediate peaks disappeared and showed the formation of a broad signal next to the TMAL peak, confirming methylaluminoxane formation.

Example 8

4-methyl-3-pentene-2-one (Mesityl Oxide) as Reactant

(29) A 10 ml glass vial equipped with a magnetic stirring bar was charged with 1.3 g toluene and 0.36 g (5.0 mmol) trimethylaluminium (ex AkzoNobel). To this solution, 0.34 g (3.5 mmol) of 4-methyl-3-penten-2-one (ex Sigma-Aldrich) was slowly added, resulting in an exothermic reaction with gas formation.

(30) .sup.1H-NMR analysis of the reaction product after dosing showed multiple peaks in the Al-Me region, which is indicative of the presence of intermediate products. The reaction mixture was left to stir at room temperature for 20 hours.

(31) The mixture was then heated to 105 C. (oil bath) for 1 hour.

(32) .sup.1H-NMR analysis showed that the intermediate peaks disappeared and showed the formation of a broad signal next to the TMAL peak, confirming methylaluminoxane formation.