DE1595170B1 - Method for preventing the cold flow of cis-polybutadiene elastomers - Google Patents

Description

Suitable solvents for the active halogen of cis-polybutadiene elastomers, which by poly-20 containing compound are e.g. B. the substances which are used as the merization of 1,3-butadiene according to known diluents in the production of ice-polishing methods in the presence of known stereospecibutadiene. Such solvents for organometallic mixed catalysts are well known to the person skilled in the art. After the polymerization has been completed, the treatment agent is added to the polymerization mixture prior to injection and the mixture is agitated in order to facilitate the contact activation of the catalyst, a halogenated olefin of the reagents. The temperature can be set or a halogenated ether, the at least two as desired either before or after addition of the active halogen atoms in the α-position to the double treatment agent,
bond or wear to the ether oxygen atom and The reaction of the halogenated olefin with the

with the olefin or the ether up to 20 carbons- 30 solution of the unquenched cis-polybutadiene

can be carried out at a temperature between about -7 and about 120.degree. C., preferably about 15 to 80.degree will. The treatment time depends on both the temperature and the one used desired physical properties in and 35 halogen-containing compound. Generally lies

atoms per molecule, is added and the mixture hold 5 minutes to 5 hours at a temperature in the range of about -7 to about 120 ⁰ C. The obtained cis-polybutadiene retains

his

also has better resistance to cold flow in the unvulcanized state.

A group of organic reactive materials that can be used in the present invention are they range from 5 minutes to 5 hours.

There is a further group of organic reactive substances which can be used according to the invention from ethers that contain at least two active halogen

halogen-containing olefins that contain at least two active atoms attached to carbon atoms

Halogen atoms, d. H. at least 2 halogen atoms bonded to carbon atoms, which are in α-position to a doubly bonded carbon atom are included. The active halogen atoms can be attached to the same or different carbon atoms in the molecule. the Compounds can contain up to 20 carbon atoms per molecule and can be partial or be fully halogenated. "Olefins", which can also be cyclic in nature, are not intended here only monoolefins but also diolefins are understood. The active halogen containing compounds can contain fluorine, chlorine, bromine or iodine or mixtures of these halogens. However are bound, which are in α-position to the ether oxygen.

The ethers added according to the invention have the following general formula:

- O

wherein X is hydrogen or halogen, saturated aliphatic hydrocarbon radicals, saturated cycloaliphatic Hydrocarbon radicals, aromatic hydrocarbon radicals, halogen-substituted saturated

chlorine, bromine and iodine are preferred, in particular aliphatic radicals, halogen-substituted saturated ones

Compounds that contain chlorine. The halogen-containing compounds can have various hydrocarbon substituents, such as alkyl, cycloalkyl, aryl, aralkyl or alkaryl groups. Dercycloaliphalic Radicals and halogen-substituted aromatic radicals and R saturated aliphatic hydrocarbon radicals, saturated cycloaliphatic hydrocarbon residues, aromatic hydrocarbon residues,

like active halogen containing compounds 60 halogen-substituted saturated aliphatic radicals, halo-

consist of carbon, hydrogen and halogen atoms.

Specific active halogen-containing compounds of the group indicated which can be used in the practice of the invention, ^f) 5 are e.g. B. the following:
Hexachloropropene,
3,3-di-bromo-1-chloro-1-propene, gene-substituted saturated cycloaliphatic radicals, halogen-substituted aromatic radicals and resle of the formula

- C X

ORIGINAL INSPECTED

25th

mean and which contain at least 2 halogen atoms, which are adjacent to your ether oxygen Carbon atoms. The ether compound can contain up to a total of 20 carbon atoms per molecule and can be partially or fully halogenated. Also mixtures of the different halogenated ether compounds can be used. The active halogen containing compounds can contain fluorine, chlorine, bromine or iodine or mixtures of these halogens. However will Chlorine, bromine and iodine compounds are preferred, especially chlorine-containing compounds. Because the ether connection must contain at least 2 halogen atoms, which are located on carbon atoms in «-Position to the ether oxygen, they are hereinafter referred to as« -halogenated ethers.

Specific examples of α-halogenated ethers used in the practice of the invention can be the following:

Bis (chloromethyl) ether, bis (l-bromoethyl) ether,

Methyl dichloromethyl ether,

Bis (l-fluoropropyl) ether,

Chloromethyl-l-chloropropyl ether,

Bis (l-iodopentyl) ether,

Bis (l-chlorodecyl) ether,

Hexyl 1,1-dichloroheptyl ether,

1 -chloro-n-butyl-1,1-dichloro-n-butyl ether,

Bis (1,1 -dibromodecyl) ether,

1,1-difluoroethyl-1 -fluorhepty lather, Bis [1-bromo (2-ethyl) butyl] ether,

Difluoromethyl-1-fluoropropyl ether,

1,1-dibromohexyl-1,1-dichlorodecyl ether,

U-dichloropropylcyclohexyl ether,

1-chloro-1-bromobutylphenyl ether, ^

Kl-DijodpentyM-chlorbenzy lather.

1,1 I-Trichlorhexyk ^ -chlorocyclohexyl ether.

Bis (trichloromethyl) ether,

Bis (dichlorophenylmethyl) ether,

Bis [difluoro- (4-tolyl) methy]] ether, 1 -chloro-1-bromo-3-phenylpropylhexachloro-

phenyl ether,
1,1 -dichlorobuty 1-1,1,4-trichloro-3-n ~ propy 1-

7-phenylheptyl ether.

The implementation of the -halogenated ether with the solution of the non-quenched cis-polybutadiene can be at a temperature in the range from about -7 to about 120 ° C, preferably -7 to 80 ° C, be performed. The treatment time depends on both the temperature and the one used «-Halogenated ether. It is in the range of 5 minutes for mixing the -halogenated Ether treatment agents with the polymer solution are required up to 5 hours. If the polymerization temperature is above about -7 C, you can often get satisfactory results with A treatment time of 5 minutes when the temperature is at that used for the polymerization Height is maintained. In other cases, depending on the desired results, a longer treatment time at higher temperature is preferred.

The amount of halogenated olefin or halogenated Ether used to reduce the cold flow of cis-polybuladiene, is based on the organometallic component of the catalyst. It is generally in the range from 0.05 to 10 mmoles per mole of organometallic compound.

The polybutadienes can be made by polymerizing butadiene with a catalyst system obtained by mixing substances that contain an organometallic compound and iodine, the latter being added in the free or bound state, is formed. Such a thing Polymerization system provides an ice-polybutadiene, which has superior physical properties exhibits in the vulcanized state, but in the unvulcanized state a tendency to cold flow when the treating agent is not added. The term "ice-polybutadiene" is used here in the sense that including a polybutadiene with at least 85% cis-1,4 addition, d. H. between 85 to 98% and more, is understood. The following are examples of preferred catalyst systems indicated, which is used for the polymerization of 1,3-butadiene to form a cis-1,4-polybutadiene can be:

Triisobutyl aluminum and titanium tetraiodide,
Triisobutyl aluminum, titanium tetrachloride and

Titanium tetraiodide,

Zinc diethyl and titanium tetraiodide,
Triisobutyl aluminum, titanium tetrachloride and iodine, triisobutyl aluminum, titanium tetrachloride and

1,4-Diiodo-2-butene.

The polymerization process for the production of cis-polybutadiene is generally carried out in the presence run of a hydrocarbon diluent, which door the catalyst system harmless is. Examples of suitable diluents are e.g. B. aromatic, paraffinic and cycloparaffinic Hydrocarbons.

In the polymerization of 1,3-butadiene to form a cis-polybutadiene, the amount of organometallic is higher Compound used for the preparation of the catalyst composition in general in the range of 0.75 to 20 moles per mole of halogen-containing catalyst component, d. H. one Metal halides with or without a second metal halide or elemental iodine. The concentration the total catalyst composition, d. H. of organometallic compounds and halogenated compounds Catalyst component, is usually in the range from 0.01 to 10 percent by weight, preferably in Range from 0.01 to 5 weight percent based on the total amount of 1,3-butadiene in the reactor system is introduced.

After completion of the polymerization reaction, the organic compound, the at least two contains active halogen atoms which are bonded to carbon atoms in the «position to a double bonded carbon atom or an ether oxygen atom are added to the polymerization mixture. The mixture is then thorough moved to ensure contact of the reagents. After completing this stage, the reaction mixture is then treated to inactivate the catalyst and recover the polymer. The inactivation step can be carried out in any of the known ways. A suitable one One method of inactivating the catalyst is to add an alcohol.

For a better understanding of the invention, two preferred embodiments are given in the following examples explained.

example 1

The following approach was used to make ice-polybutadiene:

Toluene, parts by weight KX) O

1.3-butadiene, parts by weight KK)

Triisobutyl aluminum, mhm ') ... 3.76

Iodine. mhm ¹ ) 0.9

Titanium tetrachloride, mhm ¹ ) 0.447

Temperature, C 5

Duration, hours 3

') Millimoles per 100 grams of 1,3-butadiene.

First the toluene was added, then the reactor was purged with nitrogen, butadiene and then triisobutyl aluminum, iodine and titanium tetrachloride were added. A series of five Approaches was carried out. After 3 hours of polymerization, each of two batches was used treated with 2 mmol of a different halogenated organic compound, namely the one with hexachlorocyclopentadiene and the other with hexachloropropane. One approach was used to compare kept, d. i.e., no halogenated organic reagent compound was added here. All three Polymerization mixtures were then heated to 70 ° C. and stirred at this temperature for 15 minutes. Then, hexachlorocyclopentadiene and hexachloropropene were added in amounts of 2 mmol each of the other two batches were added, and the mixtures were stirred for 30 minutes, with the Temperature was kept at 5 ° C. Then a solution of 2,2'-methylene-bis (4-methyl-6-tert.-butylphenol) in isopropyl alcohol is added to each of the batches in an amount sufficient to to provide approximately 1 part by weight of antioxidant per 100 parts by weight of rubber. Then the Polymers coagulated in isopropyl alcohol, separated off, dried and the cold flow determined. The following results were obtained:

Treatment of the polymer

approach

Halogenated organic Iceine temperature Duration of treatment Monomeric
conversion ¹ ) Cold flow ² ) Reagent compound Hexachlorocyclopentadiene Hexachloropropene C. Minutes % mg / min Hexachlorocyclopentadiene. 70 15th 88.3 8.31 Hexachloropropene 70 15th 81.6 2.96 70 15th 78.3 0.00 5 30th 84.2 4.97 5 30th 90.3 2.13

') Calculated from the weight of the product obtained.

~) The cold flow is determined by extruding the rubber through a nozzle with a diameter of 0.5 mm at a pressure of ^{0.25 kg cm 2} and a temperature of 50 ° C. After waiting 10 minutes for the equilibrium to be established , the

The extrusion rate was determined and reported in mg min. Example 2

The following approach was used to produce eis polybutadiene:

Toluene. Parts by weight KK) O

1,3-butadiene, parts by weight 100

Triisobutyl aluminum, mhm ¹ ) 2,3

Iodine. mhm ¹ ) 0.8

Titanium tetrachloride, mhm ¹ ) 0.4

Temperature. C 5

Duration. Hours 0.5

') Millimoles per 100 g of butadiene.

First the toluene was introduced, then the reactor was purged with nitrogen, and butadiene and then triisobutyl aluminum, iodine and titanium tetrachloride were added. Two approaches were made carried out. A sample was obtained in each batch after a polymerization time of 0.5 hours taken and cold flow and conversion were determined. The remainder of batch 1 was 8 mmol per KK) g of butadiene bis (chloromethyl) ether used was added, and the mixture was stirred for 30 minutes stirred while the temperature was kept at 30.degree. Then one part by weight of 2.2'-methylenebis (4-methyl-6-tert.-butylphenol), dissolved in a mixture of equal volumes of isopropyl alcohol and toluene per KK) parts by weight of polymer added, whereupon the polymer was coagulated in isopropyl alcohol, separated off and dried. Then were Cold flow and conversion determined again. The final conversion was from the weight of the product obtained. After the first part of batch 2 was removed, the The remainder is heated to 30 ° C. for 30 minutes while stirring. The polymer was then obtained as in batch 1, and cold flow and final conversion were determined.

The following results were obtained:

1 2 Conversion, "". 0.5 hours ...
^so cold flow, mg min
originally
after treatment with
Bis (chloromethyl) ether
_ss after 30 minutes of heating
30 C 51
2.8
0.04
85 50
2.3
0.83
97 Final conversion

These results show that heat treatment alone reduces the cold flow was obtained, but this effect was not nearly as pronounced as in the approach in which the Solution of the non-quenched polymer was treated with bis (chloromethyl) ether.

('5

Claims (2)

Patent claims: 1. Process for preventing the cold flow of cis-polybutadiene elastomers, which are produced by poly- merization of 1,3-butadiene by known processes produced in the presence of known stereospecific organometallic mixed catalysts have been characterized that the polymerization mixture before inactivation of the catalyst, a halogenated olefin or a halogenated Ether, the at least two active halogen atoms in α-position to the double bond or to the ether oxygen atom carry and wherein the olefin or the ether contains up to 20 carbon atoms per molecule, and the mixture takes 5 minutes at a temperature in the range of about -7 to about 120 ° C for up to 5 hours. 2. The method according to claim 1, characterized in that the reaction mixture 0.05 to 10 mmoles of the olefin or ether per mole of that used to form the polymerization catalyst organometallic compound used. 909538/174