DE1292380B - Process for the removal of metal-containing catalyst residues from solid polymers - Google Patents

Description

1 2

Process for the polymerization of unsaturated carbons The process is facilitated when the treatment Hydrogen to solid, high-molecular-weight polymers; : with the higher alcohol in the presence of an eye weight in the presence of a metal-containing minium halide or an aluminum alkyl halide catalyst have already been described. A genids is performed. It was becoming more like that metal-containing catalyst can be found by 5 that a similar effect is obtained when Implementation of a transition metal compound, such as treatment with the higher alcohol in counter for example Titanium tetrachloride, titanium trichloride or the replacement of hydrogen chloride or acid chlorides by vanadium tetrachloride, with an organic metal, which in the presence of higher alcohols give off a compound such as an aluminum alkyl, an alkyl hydrogen chloride.

aluminum halide, an alkyl complex of an io The invention relates to a process for Alkali metal with aluminum, for example lithium removal of metal-containing catalyst residues aluminum tetraethyl qder an alkali metal alkyl); those made of solid polymers produced by polymerization are formed. These methods of polymerization of vinyl group-containing hydrocarbons can be used in the presence of an inert liquid, such as in the presence of a transition one Hydrocarbon, or in the presence of a metal compound and an aluminum alkyl be excess Amount of unsaturated carbon standing catalyst have been produced by Hydrogen can be carried out in the liquid phase.Treatment with an alcohol and hydrogen chloride, the. * "'' which is characterized by the fact that the on

Examples of particularly valuable solid polymers that are mixed with the mixture obtained at the end of the polymerization produced by this process, poly- so are 5 to 50 percent by weight of the insoluble ethylene present and polypropylene, most particularly the soleplate polymer of at least 8 carbon atoms called isotactic, crystalline polypropylene. containing alcohol and up to 10 percent by weight

A crude percent of the insoluble polymer present, chlorine product, which can be obtained by this process generally consists of a solid polymer or hydrogen in the presence of the higher with enclosed metal-containing catalyst as alcohol, hydrogen chloride-forming acid chloride residues and usually treated from a slurry, separates the solid polymer present in an inert liquid or in and with liquid hydrocarbon. ' Excess of the unsaturated hydrocarbon. In ■ ·; ·. As an alcohol with at least 8 carbon atoms the inert liquid can be atactic, amorphous, for example octanols, nonanols, Polymer be dissolved. 30 'decanols and the dodecanols are used.

These metal- ^{containing catalyst residues (} because of its ready availability must be removed from the polymer,. a very suitable higher alcohol under heat. ^':: · extensive oxidation of metallenthalten-

It is already known that these residues .35; the residues in the polymer before treatment from the polymer by removing the one with the higher alcohol should be avoided Polymer with copious amounts of a lower one as this leads to the formation of insoluble metal compounds Alcohol treats and washes. leads .. The contact of the polymer with air is therefore

After an earlier, not pre-published half, preferably restricted as much as possible, Suggestion can remove catalyst residues by doing 40 to the treatment with the higher alcohol from ' be removed so that the polymer is closed from the polymer. The polymer can, however, before the after the end of the polymerization! treatment with the higher alcohol, separated in a closed manner and then with hydrogen chloride and a separate container in the presence of very small quantities Mixture of an alcohol and a liquid carbon - air can be stored. Preferably this is hydrogen is treated, followed by 45 methods according to the invention in the absence of air for example with an alcohol. carried out.

The preferred alcohols contain up to 4 carbons. The liquid hydrocarbon can consist of one with material atoms. A disadvantage of this process is the inert carbon used in the polymerization, that there is a special stage of work, namely hydrogen or from .dem., unsaturated carbon that Filter off or decant off the polymer 50 hydrogen monomer, the polymerization of the polymerization liquid required what was subjected to. Preferably a low boiling one Carrying out the process in large-scale hydrocarbon used as such on a large scale is uneconomical. Hydrocarbon easily differs from the higher alcohol

According to an older proposal by the inventor, the following is fetched by distillation contained in a metal removal process? 55 Recovery of "the hydrocarbon" separation the catalyst residues from solid polymers un-,. leaves. ...

saturated hydrocarbons the polymer with a '' Der. higher alcohol, the higher the polymerization alcohol in the presence of an inert liquid product, the * the "inert liquid hydrocarbon and subsequently the solid polymer and / or the unreacted unsaturated carbon is recovered. Such a process added the pre-hydrogen containing. Here, weizug, that the catalyst residues in the inert terer liquid hydrocarbon, if necessary, Liquid can be made more soluble than added when using.

formation of lower alcohols and a polymer with a particularly suitable inert liquid hydrocarbon

results in a very low ash content. So one of the substances are paraffinic hydrocarbons, such as propane, requires less amount of the higher alcohol than 65 butane, pentane. The corresponding olefins, such as Use of lower alcohols is required, and propylene, can also be present. Is the the following procedure for separating the hydrocarbons under normal gas conditions was used Liquids is relatively easy. shaped, it should be pointed out that sufficient

Pressure should be applied to liquefy it.

Of the acid chlorides, thionyl chloride, sulfuryl or acetyl chloride are preferred their ready availability applied.

The hydrogen chloride or the acid chloride will used in amounts up to 10 percent by weight of the polymer insoluble in the inert liquid. It is preferable to use between 1 and 5 percent by weight, based on the insoluble polymer, a. The amount used depends on the amount and type of metal-containing catalyst residues in the polymer, and in some cases small amounts of hydrochloric acid, for example 0.1% by weight, are obtained of the insoluble polymer, excellent effects.

, The amount of higher alcohol to use depends on the amount of metal-containing catalyst residues in the polymer. Hence can the amount of the higher alcohol can be varied widely. Usually between 15 and 50 percent by weight will range Alcohol based on the weight of the insoluble in the inert liquid hydrocarbon Polymers, from. However, if the amount of the metal-containing residue is small, fewer can as 15% by weight alcohol, e.g. 5%, can be used.

If you want to win the polymer in isotactic form, it is particularly useful that Take the smallest amount of alcohol to remove the metal-containing catalyst residues is required. This results in the precipitation of atactic fractions from the solution in the liquid hydrocarbon largely or entirely avoided.

The treatment with chlorine- ^ 5 hydrogen or acid chloride and the higher alcohol at a temperature of at least 70 ° C carried out. Particularly suitable temperatures are between 70 and 80 ° C. At lower temperatures is the rate of reaction between the alcohol and the catalyst residues low, while at higher temperatures the polymer slurry tends to coagulate. Regardless of these difficulties, however, the temperatures to be used may, for example, be between 50 and 100 ° C.

The process according to the invention can preferably be used to remove metal-containing catalyst residues from polymers of unsaturated hydrocarbons such as polyethylene and polypropylene, which have been prepared in the presence of a catalyst by reacting a Titanium compound, for example a titanium halide such as titanium tetrachloride or trichloride, with a Aluminum alkyl is formed.

After treatment with hydrogen chloride or an acid chloride and the higher alcohol it becomes the solid polymer is separated from the liquid components of the mixture, for example by filtration and washed with a hydrocarbon, preferably that used as the reaction medium in the Polymerization process served, best with a low-boiling hydrocarbon, for example with a boiling point lower than 120 ° C, such as a petroleum ether, propane or propylene.

This washing process can be carried out in stages, and as washing liquid in the Hydrocarbon used in the first stage may contain a small amount of a higher alcohol. However, it is preferred, particularly at the final stage of the washing process, to use one of alcohols to use free hydrocarbon. By washing the isolated polymer with a hydrocarbon the precipitation of a small atactic fraction from the solution in the liquid hydrocarbon, adhering to the polymer prevents. Removing the remaining alcohol before Further processing is very desirable, otherwise blistering and odor will result in the polymer can. The polymer is therefore preferably subjected to a treatment with steam at the end, to remove the last traces of the liquid hydrocarbon and alcohol. Here it is advantageous when working in the presence of a small amount of a wetting agent. Finally will the polymer dried in vacuo.

example 1

0.42 g of thionyl chloride was added to a polypropylene slurry containing a catalyst from aluminum triethyl and titanium trichloride in petroleum ether (b.p. 80 to 100 ° C) was prepared. The sludge was stirred at 78 ° C. for 0.5 hours, and 8.3 g of nonanol (3,5,5-trimethyl-hexanol-1) were added and the mixture was stirred for an additional hour. The polymer was washed four times with petroleum ether at 78 ° C washed and the ether then removed by steam distillation. After drying in vacuo the weight of the insoluble crystalline polymer was 34 g. The ash content was 0.03%.

Example 2 to 4

The procedure was as in Example 1, but instead of thionyl chloride, sulphuryl chloride, Acetyl chloride or hydrogen chloride is used. The results were similar to those of Example 1 in Table 1 registered.

Tabel

example Chloride compound ° / o (w / w) chlorides,
calculated on the unsolved
polymer ° / o (w / w) nonanol,
calculated on the unsolved
polymer polymer
G Vo
(W / w)
ash 1
2
3
4th Thionyl chloride
Sulphuryl chloride
Acetyl chloride
Hydrogen chloride 1.45
1.8
7.5
1.3 28.6
29.4
28.5
30.6 29.0
28.3
30.5
29.7 0.03
0.01
0.03
0.05

The polypropylene had an ash content prior to treatment by the method described above of 0.23%.

Examples 5 to 7

■

A slurry of solid polypropylene in petroleum ether was used as the starting product, which was passed through Polymerization of propylene in the presence of titanium trichloride and aluminum triethyl using of petroleum ether (b.p. 80 to 100 ° C) was obtained as the reaction medium. The polymer had after Separate from the solvent, wash with fresh petroleum ether and dry to an ash content of 0.3%.

The following tests were all carried out using 250 cc polypropylene sludge carried out containing 25 g of insoluble polymer. Hydrogen chloride was then added to the sludge, which was then stirred and heated to 75 ° C for 30 minutes. The nonanol (3,5,5-trimethyl- ao Hexanol-1) was added and stirring was continued at 75 ° C. for 1 hour. This treatment resulted in the originally purple color of the sludge, which is then filtered and washed four times with 150 ecm petroleum ether each time became. Water containing a small amount of a wetting agent was added to the solid polymer and the remaining petroleum ether is removed by steam distillation. After washing with water and drying in vacuo at 60 ° C, the ash content was determined and a molded piece through Presses made at 190 ° C.

Table 2 below contains the amounts of hydrogen chloride and nonanol used, the Ash content of the treated polymer and the color of the molding.

Table 2

at
game (W / w)
Chlorinated water
fabric, calc
net on un
soluble
polymer (W / w)
Nonanol,
calculated
on unsolvable
liches
polymer Vo
ash Color of
Fitting 5
6th
7th 1.8
1.8
3.3 8.9
21
49 0.08
0.01
<0.01 nearly white
clear as water
clear as water

Claims (1)

Claim: Process for removing metal-containing catalyst residues from solid polymers, those obtained by polymerizing vinyl group-containing hydrocarbons in the presence a catalyst composed of a transition metal compound and an aluminum alkyl have been made by treatment with an alcohol and hydrogen chloride, thereby characterized in that the mixture obtained at the end of the polymerization with 5 to 50 weight percent of the insoluble polymer present of at least 8 carbon atoms containing alcohol and up to 10% by weight of the insoluble polymer present Hydrogen chloride or one which forms hydrogen chloride in the presence of the higher alcohol Treated acid chloride, separating the solid polymer present and with liquid hydrocarbon washes.