CS249520B2 - Conjugated diolefins' polymerization or copolymerization method - Google Patents

Abstract

The process is carried out in the presence of a catalyst the reaction product system a metal compound which is a compound neodymium, praseodymium or a mixture thereof, an organic halogenated general derivative the formula in which X represents an atom chlorine or bromine, R is C 1 -C 6 alkyl, phenyl, C 1 -C 6 chloroalkyl or bromoalkyl, and C 1 -C 6 alkoxy, R * 1 is C 1 -C 6 alkyl, phenyl, hydrogen, chlorine or bromine, R 2 is C 1 -C 6 alkyl, phenyl, vinyl, C 1 -C 6 chloroalkyl or bromoalkyl, chlorine or bromine, or R 1 + R 2 represent an oxygen atom, and an organometallic compound aluminum AlRaRb in which Ra is C 1 -C 6 alkyl and R b is hydrogen or C 1 -C 2 alkyl. Organic molar ratio halogenated derivative to the metal compound is equal to or greater than 0.33 and molar the ratio of organometallic aluminum compound to the metal compound is equal to or greater than 20. The reaction is carried out in the presence or absence solvents. This procedure conjugated diolefin can be obtained polymers with a high content of 1,4-cis units with molecular control weight and linear structure.

Description

The invention relates to a process for the polymerization or copolymerization of conjugated diolefins to produce polymers having a preferred high content of 1,4-cis units and high chain linearity.

Several methods of making conjugated diolefin polymers are known in the art, using rare earth metal catalysts. For example, Czechoslovak Patents Nos. 209,535 and 209,536 disclose the use of a lanthanide metal chelate with a monovalent or monovalent organic moiety to prepare polybutadiene having a high content of 1,3-cis structural units.

Similarly, chelates of said metals with monovalent bivalent or divalent organic residues may be used to prepare products with a high 1,4-cis content (see, for example, U.S. Patent Nos. 3,297,667 and 3,794,604).

In all these cases, in addition to the metal compounds, a catalytic system consisting of a trialkyl or dialkyl aluminum monohydrate and a halide ion is added in the form of a Lewis acid.

As mentioned above, the above processes for the preparation of 1,3-butadiene, isoprene or 1,3-pentadienes in the form of polymerates or copolymers are characterized by a high content of 1,4-cis structural units. However, the use of the above catalyst systems does not have the drawbacks of, for example, the production of a very low molecular weight polymer (see, for example, U.S. Patent 3,641,188) or an excessively high molecular weight (when operated without an inert diluent). as described in the above-mentioned Czechoslovak patent).

In addition, although the polymers prepared according to these prior art processes are soluble in certain hydrocarbon solvents, they are not soluble in the corresponding monomer in their liquid state. This latter fact is very important in cases where it is desired to perform internal polymerization, i. in the absence of any solvent added.

It has been found possible to carry out a process for the preparation of conjugated diolefin polymers or copolymers to produce products with a high content of 1,4-cis units and high chain linearity which does not have the above drawbacks using a new catalyst system consisting of a reaction product of a metal compound. which is a neodymium compound, praseodymium or a mixture thereof, an organic halogenated derivative and an organometallic aluminum compound.

The principle of the polymerization or copolymerization of conjugated diolefins according to the invention is to be carried out in the presence of a catalyst system consisting of the reaction product of a metal compound which is a neodymium compound, a praseodymium compound or a mixture thereof, an organic halogenated derivative of the formula

R ¹

R = C-X

R ² in which is

X is chlorine or bromine,

R is hydrogen, (C 1 -C 6) alkyl, phenyl, (C 1 -C 6) chloroalkyl or C 1 -C 6 bromoalkyl, (C 1 -C 4) alkoxy,

R ¹ is an alkyl group having 1 to 6 carbon atoms, a phenyl group, a hydrogen, chlorine or bromine atom,

R ² is C 1 -C 6 alkyl, phenyl, vinyl, C 1 -C 6 chloroalkyl or C 1 -C 6 bromoalkyl, chloro or bromo, or

R ¹ + R ² represent an oxygen atom, and organometallic compounds of aluminum of the general formula

AlR ^a R ^b wherein means

R is ^a linear or branched alkyl group having 1 to 6 carbon atoms, and

R ^b is a hydrogen atom or an alkyl group having 1 to 2 carbon atoms, wherein the molar ratio of the organic halogenated derivative to the metal compound is equal to or greater than 0.33 and the molar ratio of the organometallic aluminum compound to the metal compound is equal to or greater than 20 in the presence or in the absence of a solvent.

One advantage of the process of the present invention is the stability of the organic halogen derivatives as compared to the metal halides, making their use easier. A further advantage of the process of the present invention is that the reaction temperature is not a critical criterion, so that even when operating in a bulk polymerization system, conjugated diolefin polymers with high 1,4-cis units are obtained while controlling molecular weights and linear structure such that the product has excellent solubility of the polymer or copolymers both in aliphatic hydrocarbons, taic and monomers as such in the liquid state.

Preferably, the reaction is carried out in the presence of an aliphatic hydrocarbon solvent, preferably the hexane.

The temperature of the above-mentioned polymerization or copolymerization of conjugated diolefins is preferably in the range of from 10 to 100 ^° C. However, the reaction can also be carried out at higher temperatures, for example at 0 to 200 ° C or at higher temperatures.

The use of an inert diluent for the polymerization or copolymerization of conjugated diolefins is not necessarily necessary, since the polymerization can be controlled even in the complete absence of the inert diluent. Where diluents are suitable, the diluent may be a hydrocarbon solvent, as mentioned above, preferably an aliphatic hydrocarbon solvent. However, it is also possible to use another, for example cycloaliphatic solvent.

Also, the polymerization temperature is not an important parameter, and so it is possible to choose this temperature from a very wide range, preferably from 10 to 100 ° C, possibly from a wider range from 0 to 200 ° C, or this temperature may still be higher. This temperature has no significant effect on the characteristics of the polymer, except for the molecular weight and molecular weight distribution, which varies in the same sense as above.

The monomer can be completely converted to the polymer in the absence of diluents in the process of the invention.

The technological, mechanical and elastic properties of the obtained β-polymer products are excellent even after curing, since the content of 1,4-cis units is always very high (greater than 98%) and the structure of the polymer is perfectly linear.

For example, the melting point of the polybutadiene is in the range of the highest values found, and is in the range of +3 to + 5 ° C (measured at the DSC peak).

All conjugated diolefins, especially 1,3-butadiene, 1,3-pentadiene and isoiprene, can be included in the group of monomers which can be polymerized according to the invention.

Copolymers of two or more of the above monomers are of interest in terms of their microstructure, which is essentially entirely composed of the 1,4-cis' type, and the statistical distribution of monomer units.

There is no need to purify the polymer from the deactivated catalyst residues because of their low amount and because they are substantially inert.

The above-mentioned metal compound, which represents the first component of the catalyst system used in the process of the present invention, can be any compound commonly known in the literature, whether organic or inorganic.

With respect to the organic halogenated derivative represented by the above formula for the second component of the catalyst system used in the process of the present invention, it should be noted that the alkyl radicals may be linear or branched, said radicals having 1 to 6 atoms as mentioned above. carbon.

Typical examples of organic halogenated derivatives which may be used as catalyst components of the catalyst system are, for example, benzoyl, propionyl, benzyl, benzylidene or tertiary butyl chlorides or bromides, said radicals being both bromides and chlorides, methyl chloroformate or bromoformate, chlorodiphenylmethane or chlorotrifenylmethane and the like.

The third component of the reaction product constituting the catalytic system for the process of the present invention consists of one or more non-metal halide-free organometallic aluminum compounds which may be represented by the general formula:

AlR ^a R ^b in which R ^b and R ⁿ are as defined above.

The catalyst system for the process of the invention may be prepared either in the absence or in the presence of a monomer or a mixture of monomers to be polymerized. In both cases, the preparation may be carried out either in the absence or in the presence of a hydrocarbon solvent, which is preferably selected from the group consisting of hydrocarbon aliphatic solvents, preferably hexane.

The order in which the three components of the catalyst system are contacted in preparing the catalyst system is not important in terms of both kinetics and subsequent polymerization reactions.

The prepared catalyst can also be left to aging for long periods of time without any change in composition.

The molar ratio of the three components of the catalyst system prepared as described above is as follows: the molar ratio of the organic halogenated derivative to the metal compound is greater than or equal to 0.33, and preferably is in the range of 0.5 to 3, the ratio of the organometallic aluminum compound to the metal compound is greater than 20, and preferably 250-220 is between 30 and 200.

The process of the present invention will be described in detail by means of the following non-limiting examples.

Example 1

In this embodiment, a 2-liter steel autoclave equipped with a stirrer and a temperature controller was first evacuated using a mechanical vacuum pump, and then 500 grams of anhydrous butadiene was charged.

The autoclave was then heated to an external temperature of 80 ° C and immediately quenched with 5 ml of a hexane solution containing 0.15 mmol Nd (OChH 9) 3, 7.5 mmol Alfi.CdHtejzH and 0.225 mmol benzoyl chloride. in the dissolved state, the injection was carried out with a laboratory syringe under nitrogen pressure. The reaction mixture was then maintained at 80 ° C with stirring for 90 minutes. The experiment was then interrupted by introducing 2 ml of dilute ethanol in 50 ml of hexane.

The polymer mass was then removed from the autoclave and dried under vacuum at 50 ^° C to give 198 grams of a dry product, which was found to be 98.5% by weight of cis-polybutadiene as determined by infrared analysis. The viscosity limit measured in toluene at 30 ° C for this product was 5.15 dl / g.

Example 2

First, a 1.5 ml hexane solution was first prepared over 15 minutes by reaction of Nd (OCaH 9) 3 (corresponding to 0.054 mmol) followed by Al (i.CaH 9) 2H at 2.7 mmol and tertiary butyl chloride in 0.081 mmol, and this solution was introduced under an inert atmosphere into a thick-walled 1 liter glass container.

The container was then sealed with a crown cap and a flat rubber gasket. 120 grams of butadiene was then introduced into the vessel through an orifice from a cylinder equipped with a spray needle, and the mixture was then maintained under stirring by a magnetically driven anchor stirrer. The reaction was carried out for one hour in a bath controlled at 30 ° C.

The polymer was recovered by draining excess butadiene and drying the residue in vacuo to give 74 grams. The Mooney viscosity was 72.5 ML (1 + 4, 100 °). The melting point (DSC) in this case was + 3 ° C.

Example 3

The same reactor was used as in Example 1, except that the reactants except benzoyl chloride were reacted therein and the benzoyl chloride was replaced with an equivalent molar amount of methyl chloroformate.

The reaction was carried out at 60 ° C and lasted 45 minutes. The polymer, separated and dried in the same manner as described above, weighed 110 grams and contained 99% 1,4-cis butadiene units with respect to the microstructure.

Example 4

130 ml of anhydrous hexane, 18.5 g of butadiene and a 2 ml solution of hexane containing 0.032 mmol of neodymium trinaphthenate, 0.048 mmol of benzoyl chloride and 1.6 mmol of aluminum diisobutyl monohydride were introduced into a glass vessel of the same type under a nitrogen atmosphere. as shown in Example 2.

The vessel was rotated in a water bath controlled at 50 ° C. After three hours of reaction, the mixture was poured into excess ethanol (0.5 L). The polymer that coagulated was dried under vacuum at 50 ^° C to give 16.8 grams in the dry state.

Examples 5a 6

There were in these embodiments; The procedure was carried out in the same manner and with the same amounts of substances as described in Example 4, but analogously to butadiene polymerization, except that benzoyl chloride was replaced with t-butyl chloride and methyl chloroformate. After a two-hour reaction, the amount of polymer according to each embodiment was 17.3 grams and 14.6 grams.

Example 7

The procedure was carried out in the same manner as in Example 4, using 130 ml of hexane, 0.032 mmol of neodymium trinaphthenate, 1.6 mmol of aluminum triisobutyl and 0.096 mmol of benzyl chloride.

The reaction was carried out for 120 minutes at 50 ° C. The polymer that coagulated was dried in a conventional manner to obtain 12.1 grams of polymer.

Infrared analysis showed that the content of 1,4-cis butadiene units exceeded 99 θ / ο.

Examples 8 to 10

The butadiene polymerization was carried out in the same manner as in Example 7. The reagents and amounts used were the same as in this Example except that benzyl chloride was replaced with benzyl bromide, benzotriohloride and allyl chloride.

The polymerization was carried out for 120 minutes at 50 [deg.] C., in the following examples: 4 grams, 14.5 grams and 9.4 grams of polybutadiene.

EXAMPLE 11 A mixture of butadiene (400 grams) and isoprene (150 ml) was fed into an autoclave of the same type as in Example 1 and in the same manner as described in this example. The catalyst which was then added in the subsequent phase was prepared separately by reacting a hexane solution containing Nd (OC4H9) 3 in an amount of 0.12 mmol, 0.04 M, followed by Al (i.C4H9) 2H in an amount of 6 mmol, 1.5 M, and tertiary butyl chloride in an amount of 0.24 mmol, 0.1 M. The polymerization reaction was carried out at 60 ° C for one hour with stirring, and was then quenched by the addition of 2 ml of ethanol.

Dry weight was 165 g and ^X by H-NMR analysis, it was confirmed that the product contained a 91 ° / o of the butadiene units and 9% isoprenovýoh units. The melting point of this product, determined by DSC, was -9 ° C, and the viscosity limit, determined in toluene at 30%, was 6.02 dl / g.

lo

Examples 12 to 16

In these examples, a series of 1 liter glass containers was used to polymerize butadiene in hexane solution. The flasks were filled in the same manner as in Example 4, using the following amounts for each flask in the following order: hexane 130 ml, Nd (OC4H9) 0.032 mmol (hexane solution 0.054 IU, Al (i.C4H9jaH in an amount of 1.6 mmol (hexane solution 0.876 M), an organic chlorinated derivative of 0.096 mmol (hexane solution 0.1 M) and butadiene 18.5 g.

The chlorinated derivatives used in each case were chlorotrifenylmethane, propionyl chloride, 2-chloropropionyl chloride, benzylidene chloride and chlorodiphenylmethane. After the vessels were sealed with a crown cap, they were immediately placed on a water bath maintained at 50 ° C and stirred simultaneously.

After two hours, the polymerization was discontinued, the unreacted butadiene was vented and ethanol was introduced into the vessel. After coagulation, the obtained polymer was removed from each vessel, the individual polymer samples were dried and the weight of each sample was as follows in the examples: 17.8 grams, 17.8 grams, 13.8 grams, 5.0 grams and 17.8 grams gram. All polymers were perfectly soluble in hydrocarbons, and the content of 1,4-cis butadiene units exceeding 98 percent was found by infrared analysis.

Claims (3)

SUBJECT Process for the polymerization or copolymerization of conjugated diolefins, characterized in that it is carried out in the presence of a catalytic system consisting of the reaction product of a metal compound represented by a neodymium or praseodymium compound or mixtures thereof, an organic halogenated derivative of the general formula R ¹ R = C-X R ² in which is X is chlorine or bromine, R is hydrogen, (C1-C6) -alkyl, phenyl, (C1-C6) -alkyl, (C1-C6) -alkyl, (C1-C6) -alkyl, (C1-C4) -alkoxy, R ¹ is an alkyl group having 1 to 6 carbon atoms, a phenyl group, a hydrogen, chlorine or bromine atom, R ² is an alkyl group containing 1-6 carbon atoms, phenyl, vinyl, chloroalkyl group having 1 to 6 carbon atoms or a bromoalkyl group having 1 to 6 carbon atoms, chlorine or bromine, R ¹ + R ² represent an oxygen atom, and organometallic compounds of aluminum of the general formula AIR ^and R ^b in which it means R is ^a linear or branched alkyl group having 1 to 6 carbon atoms, and R ^b is a hydrogen atom or an alkyl group having 1 to 2 carbon atoms, wherein the molar ratio of the organic halogenated derivative to the metal compound is equal to or greater than 0.33 and the molar ratio of the organometallic aluminum compound to the metal compound is equal to or greater than 20 in the presence or in the absence of a solvent. 2. The process of claim 1 wherein said reaction is carried out in the presence of an aliphatic hydrocarbon solvent, preferably hexane. 3. The process of claim 1 wherein said reaction is carried out at a temperature in the range of from about 10 ^° C to about 100 ^° C.