JP2960972B2 - Method for producing carboxylated syndiotactic 1,2-polybutadiene - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to syndiotactic 1,
2-Relating to carboxylation of polybutadiene.

[0002]

2. Description of the Prior Art The stability of various rubbers for certain special applications is determined by syndiotactic 1,2-polybutadiene (S
It can be improved by mixing PBD) with rubber. For example, SPBD fibers can be used as tire tread base rubber to improve heat storage and wear properties.
For example, U.S. Pat. No. 4,274,462 discloses a pneumatic tire having improved resistance to heat buildup using SPBD fibers in a tread base rubber.
It has also been found that SPBD can be incorporated into tire carcass compositions to improve green strength. In fact, the inclusion of SPBD in the tire carcass composition obviated the need for electron beam precure in tire assembly operations.

The interaction and adhesion of SPBD with rubber and fillers, such as carbon black, can be improved by carboxylating the SPBD. In general, S
It is highly desirable to increase the interaction between PBD and rubber / filler. For this reason, means for carboxylating SPBD have been sought. Unfortunately, standard techniques for carboxylating organic materials have not caused significant amounts of incorporation into SPBD. For example, treatment of SPBD with sulfuric acid and formic acid did not result in appreciable introduction of carboxylic acid groups into SPBD.

[0004]

Accordingly, there remains a need for a means of significantly carboxylating SPBD.

[0005]

SUMMARY OF THE INVENTION The present invention relates to a technique for carboxylating SPBD in a relatively simple and inexpensive manner that can be easily performed on a commercial basis. More specifically, the present invention relates to (1) syndiotactic 1,2-polybutadiene suspended in an organic medium in the form of small particles having a particle size of less than about 250 microns with hydrogen and carbon monoxide. (2) reacting the formyl syndiotactic 1,2-polybutadiene with oxygen to form carboxylated syndiotactic 1,2-polybutadiene. And a method for producing carboxylated syndiotactic 1,2-polybutadiene.

The present invention further provides the following step: (1) hydroformylating the syndiotactic 1,2-polybutadiene in an organic medium, provided that the syndiotactic 1,2-polybutadiene has a particle size of about 250 microns or less. Suspended in the organic medium in the form of small particles having a diameter, and wherein the syndiotactic 1,2-
Polybutadiene is formyl syndiotactic 1,2-
In the presence of hydrogen, carbon monoxide and a hydroformylation catalyst to form polybutadiene, from about 25 ° C to about 1 ° C.
A temperature in the range of 50 ° C. and at least about 1.013 × 1
0 ⁵ is hydroformylated at a pressure of Pascal: and
(2) forming the carboxylated syndiotactic 1,2-polybutadiene by reacting the formyl syndiotactic 1,2-polybutadiene with oxygen; Production method.

Various techniques for synthesizing syndiotactic 1,2-polybutadiene in organic solvents and water are known in the art. For example, U.S. Pat. No. 3,901,868 discloses (a) a cobalt compound soluble in an organic solvent, such as (i) a cobalt-.beta.-diketone complex, and (ii) a cobalt-.beta.-keto acid ester complex. , (I
ii) A catalyst component solution is prepared by dissolving a cobalt salt of an organic carboxylic acid, and (iv) a cobalt halide-ligand compound complex, and an organoaluminum compound in an inert organic solvent containing 1,3-butadiene. (B) preparing a catalyst composition by mixing the catalyst component solution with an alcohol, ketone or aldehyde compound and carbon disulfide, (c) the desired amount of 1,3-butadiene, the catalyst composition and inertness Preparing a polymerization mixture containing an organic solvent, and (d) -20C to 90C.
Essentially syndiotactic 1,2-butane by a continuous process consisting of polymerizing 1,3-butadiene at a temperature of
A method for producing a polymer comprising polybutadiene is disclosed.

US Pat. No. 4,429,085 discloses (i) a β-diketo complex of cobalt, and (ii) a β-diketo complex of cobalt.
A keto acid ester complex, (iii) an organic carboxylic acid having 6 to 15 carbon atoms, and (iv) a cobalt halide compound of the formula CoXn, wherein X represents a halogen atom and n represents 2 or 3. A complex with an organic compound selected from the group consisting of tertiary amine alcohols, tertiary phosphines, ketones and N, N-dialkylamides, (a) at least one cobalt compound selected from the group consisting of: ₃ (wherein R represents a hydrocarbon group having 1 to 6 carbon atoms) at least one organoaluminum compound, and contains (1) the catalyst composition is microencapsulated in a polyene product; and (2) Polybuta consisting essentially of syndiotactic 1,2-polybutadiene in an aqueous medium comprising polymerizing in an aqueous solution in the presence of carbon disulfide It reveals a process for preparing ene.

US Pat. No. 4,463,146 discloses (i) a β-diketone of cobalt, and (ii) a β-diketone of cobalt.
Keto acid ester complexes, (iii) cobalt salts of organic carboxylic acids having 6 to 15 carbon atoms, and (iv) cobalt halide compounds of the formula CoXn (where X represents a halogen atom and n represents 2 or 3) A complex of an organic compound selected from the group consisting of tertiary amines, alcohols, tertiary phosphines, ketones and N, N-dialkylamides;
(A) at least one cobalt compound selected from the group consisting of: and (b) at least one organoaluminum compound of the formula AlR ₃ (where R represents a hydrocarbon group having 1 to 6 carbon atoms). (1) a catalyst composition microencapsulated in a polyene product; and (2) 1,3- in tetrahydrofuran in the presence of carbon disulfate.
A method for producing polybutadiene consisting essentially of syndiotactic 1,2-polybutadiene in tetrahydrofuran comprising the step of polymerizing butadiene is disclosed.

The syndiotactic 1,2-polybutadiene carboxylated using the technique of the present invention can be prepared using any polymerization technique. For example, syndiotactic 1,2-polybutadiene can be prepared in the organic solvents disclosed in US Pat. No. 3,901,868, the disclosure of which is hereby incorporated by reference in its entirety. It has been incorporated into. Syndiotactic 1,2-polybutadiene is also disclosed in U.S. Pat.
It can be prepared in aqueous media or tetrahydrofuran as described in 9,085 and 4,463,146, both disclosures of which are hereby incorporated by reference in their entirety. It has been incorporated into.

According to the present specification, the carboxylated syndiotactic 1,2-polybutadiene is ground or spray-frozen to about 60 mesh (250 microns or more) or finer powder. In most cases, it is appropriate to mill the syndiotactic 1,2-polybutadiene to 80 mesh (less than 177 microns) or finer particle size. For example, syndiotactic 1,
Suitably grinding the 2-polybutadiene to a particle size of 140 mesh (105 microns or less). For the purposes of the present invention, the term "particle size" refers to a powder of the indicated size passing through a sieve of the indicated size, despite the fact that some particles may be larger than the indicated particle size of a certain size. Means that. For example, a syndiotactic 1,2-polybutadiene powder having a particle size of 250 microns or less has a small particle size of some 2
Even larger than 50 will pass through a 60 mesh sieve.

Syndiotactic 1, in the form of small particle size powder
2-polybutadiene is suspended in an organic medium. Virtually any inert organic compound that is liquid and dissolves the hydroformylation catalyst without deleteriously affecting it can be utilized in the organic medium. For example, saturated aliphatic and aromatic hydrocarbons can be used as organic media.
Said compounds usually contain 4 to 10 carbon atoms per molecule and are liquid under the conditions of the hydroformylation reaction. Some representative examples of suitable organic compounds include pentane, isooctane, cyclohexane, n-hexane, benzene, toluene, xylene, ethylbenzene, and the like, alone or in a mixture.

The organic medium utilized is sufficiently agitated to maintain the syndiotactic 1,2-polybutadiene suspended therein. This is done by vigorously stirring or shaking the syndiotactic 1,2-polybutadiene suspended therein with the organic medium. The hydroformylation of syndiotactic 1,2-polybutadiene allows it to formyl syndiotactic 1,2.
Including reacting with both hydrogen and carbon monoxide to convert to 2-polybutadiene. In this reaction, the syndiotactic 1,2-polybutadiene double bond is consumed by aldehyde groups attached to the backbone of the syndiotactic 1,2-polybutadiene polymer. The hydroformylation of the double bond of syndiotactic 1,2-polybutadiene can be depicted as shown by the reaction shown below.

[0014]

Embedded image

Hydroformylation is the addition of hydrogen and carbon monoxide to alkylene to form an aldehyde. A hydroformylation reaction, commercially known as the oxo process, was discovered by O. Roelin, Germany (see US Pat. No. 2,327,066).

To carry out the hydroformylation step of the process of the present invention, syndiotactic 1,2-polybutadiene powder, carbon monoxide, hydrogen, a hydroformylation catalyst,
It is necessary to prepare a hydroformylation mixture consisting of and a liquid organic medium. Catalysts that can be used in the process of the present invention include hydride carbonyl tris (triphenylphosphine) cobalt, hydride carbonyl tris (triphenylphosphine) rhodium, and hydride carbonyl tris (triphenylphosphine) isodium and cobalt carbonyl. .

[0017] Cobalt carbonyl can be formed by the reaction of hydrogen and carbon monoxide with various cobalt compounds such as cobalt chloride, cobalt naphthenate, and cobalt carbonate. A preferred catalyst for use in the process of the present invention is PhH (CO) (P
Ph ₃ ) ₃ . The rhodium system is preferred over the cobalt and iridium systems because it produces only aldehydes in the hydroformylation reaction.

This is in contrast to cobalt complexes, which can further reduce the resulting aldehyde to alcohol. Another reason that rhodium complexes are preferred is that they are catalytically active at much lower temperatures and pressures than cobalt and iridium complexes. Rhodium catalyst at 25 ° C, 1
Very active at atmospheric pressure (1.013 × 10 ⁵ Pascals), while the cobalt and iridium systems are about 10
It is slightly higher and active at 0 ° C. and a pressure of 15 atm (1.52 × 10 ⁶ pascals).

The hydroformylation mixture used in the process of the present invention is based on the total weight of the hydroformylation mixture,
It generally contains about 5% to about 75% by weight of syndiotactic 1,2-polybutadiene. Preferably, the hydroformylation mixture of the present invention contains from about 10% to about 50% by weight of the syndiotactic 1,2-polybutadiene, based on the total weight of the hydroformylation mixture.

The amount of hydroformylation catalyst used in the hydroformylation mixture of the present invention is based on the amount of syndiotactic 1,2-polybutadiene charged into the hydroformylation mixture. Generally, the weight ratio of syndiotactic 1,2-polybutadiene to catalyst is about 50: 1 to 1
It ranges from about 10,000: 1. In most cases, the weight ratio of syndiotactic 1,2-polybutadiene to catalyst ranges from about 500: 1 to about 5,000: 1.

Of course, the hydroformylation mixture utilized in the process of the present invention also contains carbon monoxide and hydrogen. Carbon monoxide and hydrogen can be mixed into the hydroformylation mixture of the present invention by charging the utilized reaction vessel containing the hydroformylation mixture with pressurized carbon monoxide and hydrogen. If RhH (CO) (PP
If h _{3) 3} catalyst is used, only about one atmosphere (1.
Only a minimal amount of pressure, as small as 013 × 10 ⁵ Pascals, is required.

However, if CoH (CO) (PP
h _{3) 3} or _{IrH- (CO) (PPh 3)} 3 , if the catalyst is used, the time is substantially request more pressure (approximately 1.0 × 10 ⁶ Pascals). RhH (C
In the case of the O) (PPh ₃ ) ₃ catalyst, an H ₂ / CO pressure of 1.4 × 10 ⁶ Pascal to 6.9 × 10 ⁶ Pascal is preferred. If cobalt carbonyl, CoH (CO) (PPh
If _{3) 3} or IrH (Co) (PPh _{3) 3} catalyst is used, H ₂ / CO pressure is preferably up to 1.8 × 10 ⁶ Pascals ~6.9 × 10 ⁶ Pascals.

The H ₂ / CO mixture used to pressurize the reaction vessel of the present invention has a widely varying ratio of H ₂ to CO
Can have a ratio. Usually H ₂ / CO mixture according to the invention preferably contains from about 10 mole% to about 90 mole% and CO about 10 mole% to about 90 mole% hydrogen. Generally, the hydrogen-carbon monoxide mixture of the present invention comprises from about 40 mole percent hydrogen to
It is preferable to contain 60 mol% and about 40 mol% to 60 mol% of carbon monoxide. More preferably, the hydrogen-carbon monoxide mixture of the present invention contains about 50 mole% hydrogen and about 50 mole% carbon monoxide.

Since it is important for the syndiotactic 1,2-polybutadiene powder, carbon monoxide, hydrogen and the catalyst to be somewhat homogeneously distributed in the hydroformylation mixture, stirring is carried out throughout the hydroformylation reaction. It is important to continue. The hydroformylation step is performed if a RhH (CO) (PPh ₃ ) ₃ catalyst is used.
Any temperature ranging from about 25C to about 150C can be successfully achieved. If cobalt carbonyl, CoH (CO) (PPh ₃ ) ₃ or IrH (C
If an O) (PPh ₃ ) ₃ catalyst is used, the temperature is about 80 ° C.
約 150 ° C. is required to carry out the hydroformylation of the present invention. If you use _{RhH (CO) (PPh 3)} 3, it is preferable to use the general temperatures ranging from 50 ° C. to 150 DEG ° C.. If you use a rhodium catalyst,
More preferably, a temperature between 65C and 100C is used.

The optimum reaction time for the hydroformylation step of the process of the invention depends on the catalyst used, the catalyst concentration, the syndiotactic 1,2-polybutadiene concentration, the hydrogen / carbon monoxide pressure, the reaction temperature and the syndiotactic 1 , 2-
It depends on the degree to which the double bonds in the polybutadiene are hydroformylated. However, the reaction times used are generally from about 15 minutes to about 10 hours. The reaction time preferably ranges from about 30 minutes to about 4 hours, and the most preferred reaction time for the hydroformylation reaction ranges from about 1 hour to about 2 hours. It should be noted that the hydroformylation step of the process according to the invention can be carried out continuously or batchwise.

The degree to which syndiotactic 1,2-polybutadiene is hydroformylated determines the degree to which syndiotactic 1,2-polybutadiene is ultimately carboxylated. For example, if 1% of the double bonds of the syndiotactic 1,2-polybutadiene are hydroformylated, then 1% of the double bonds of the syndiotactic 1,2-polybutadiene will eventually become double bonds. Is ultimately consumed by the carboxyl group attached to the carbon atom where it was once.

Hydroformylation of more than about 3% of the double bonds in the syndiotactic 1,2-polybutadiene results in it becoming somewhat rubbery. Therefore, if the thermoplastic properties of syndiotactic 1,2-polybutadiene are retained, syndiotactic 1,2-polybutadiene will be retained.
It is undesirable to hydroformylate more than about 3% of the polybutadiene double bonds. For this reason, in most cases about 0.1 to about 3% of the double bonds of syndiotactic 1,2-polybutadiene are hydroformylated. Generally, it is preferred that about 0.2 to about 1% of the double bonds of the syndiotactic 1,2-polybutadiene be hydroformylated.

After the completion of the hydroformylation reaction, the formyl syndiotactic 1,2 produced to produce the carboxylated syndiotactic 1,2-polybutadiene.
React 2-polybutadiene with oxygen. This reaction can be depicted as shown below.

[0029]

Embedded image

As seen from the reaction formula, the formyl group attached to the backbone of the syndiotactic 1,2-polybutadiene reacts with oxygen to be converted to a carboxyl group. Therefore, formyl syndiotactic 1,2-polybutadiene is carboxylated syndiotactic 1,2-polybutadiene.
Convert to 2-polybutadiene.

The formyl groups of formyl syndiotactic 1,2-polybutadiene readily react with oxygen without the need to utilize elevated temperatures or pressures. In fact, this reaction proceeds rapidly at room temperature under the atmosphere. Moreover, air has proven to provide a sufficient supply of oxygen to facilitate this reaction. For convenience, the reaction is usually carried out at a temperature in the range of about 0 ° C. to about 100 ° C. and about 1 atmosphere (1.013 × 1
0 ⁵ Pa) at a pressure which is within the range of about 150 atmospheres (1.52 × 10 ⁷ pascals). The time required to achieve close to 100% conversion will vary with the reaction conditions, but will typically be about 1% when air is used as the oxygen source.
It is in the range of 5 minutes to about 10 hours.

In many cases, it is convenient to carry out this reaction between oxygen and formyl syndiotactic 1,2-polybutadiene during the step of drying the polymer after recovery from the hydroformylation mixture. . For example, after the completion of the formylation reaction, the formyl syndiotactic 1,2-polybutadiene can be recovered from the hydroformylation mixture by decantation or filtration.

After recovering the formyl syndiotactic 1,2-polybutadiene from the hydroformylation mixture, it can be washed with a suitable organic solvent if desired and then air-dried. The air-drying step of formyl syndiotactic 1,2-polybutadiene simultaneously causes the reaction of the formyl groups therein with oxygen, whereby the formyl syndiotactic 1,2-polybutadiene becomes carboxylated syndiotactic 1,2-polybutadiene. Convert to The drying step includes formyl syndiotactic 1,2
Can be carried out by simply passing air through the granules of polybutadiene, which granules are collected at room temperature or at elevated temperature.

Carboxylated syndiotactic 1,2
The polybutadiene typically contains no more than about 3% of carboxyl groups, based on the number of carboxylated syndiotactic 1,2-polybutadiene double bonds and total carboxyl groups. The carboxylated syndiotactic 1,2-polybutadiene made for most applications preferably has carboxyl groups based on the number of double bonds and total carboxyl groups of the carboxylated syndiotactic 1,2-polybutadiene. It contains about 0.2 to about 1%.

The carboxylated syndiotactic 1,2-polybutadiene made by the process of the present invention can be mixed into a wide variety of rubbers using standard mixing techniques. For example, carboxylated syndiotactic 1,2-polybutadiene can be mixed with rubber in a Banbury mixer or mill mixer. The mixing temperatures utilized are usually above the melting point of the carboxylated syndiotactic 1,2-polybutadiene. However, to minimize rubber degradation during the mixing process, the temperature utilized is usually just slightly above the melting point of the carboxylated syndiotactic 1,2-polybutadiene.

[0036]

The following examples are for illustrative purposes only and are not to be considered as limiting the scope of the invention or the manner in which the invention can be practiced.
Parts and percentages are by weight unless otherwise indicated.

[0037]

EXAMPLE 1 In a 1 liter stainless steel autoclave, 40 g of syndiotactic 1,2-polybutadiene having a melting point of 190 ° C., 400 g of toluene, 250 mg of hydridocarbonyltris (triphenylphosphine) rhodium and 250 psig (1.8 × They were charged 50/50% mixture of carbon monoxide and hydrogen of ¹⁰⁶ Pascals). The prepared hydroformylation mixture is heated to 65-70 ° C.
And stirred vigorously. About 50 psig after 74 minutes
A pressure absorption of (3.4 × 10 ⁵ Pascals) was observed.
The autoclay is opened and the hydroformylation mixture containing the hydride carbonyl tris (triphenylphosphine) rhodium catalyst is added to the formyl syndiotactic 1,2-
Decanted from polybutadiene. The formyl syndiotactic 1,2-polybutadiene was washed twice with 400 g of toluene. The air was then dried in a fritted funnel while pulling over the polymer granules for several hours.

Fourier transform infrared analysis indicated the presence of carboxylic acid groups on the recovered syndiotactic 1,2-polybutadiene. Differential scanning calorimetry determined it to have a melting point of 175 ° C. The carboxylated syndiotactic 1,2-polybutadiene produced was determined to contain about 5% carboxyl groups based on the number of double bonds and total carboxyl groups in the polymer.

This example shows that the process of the present invention can be used to carboxylate syndiotactic 1,2-polybutadiene. By utilizing the method of the present invention, carboxylated syndiotactic 1,
2-Polybutadiene can be produced on a commercial basis.

While certain exemplary embodiments and details have been presented for purposes of illustrating the invention, those skilled in the art will appreciate that various changes and modifications may be made without departing from the scope of the invention. Will be obvious.

──────────────────────────────────────────────────続 き Continuation of front page (73) Patent holder 590002976 1144 East Market Street, Akron, Ohio 44316-0001, U.S.A. S. A. (56) References JP-A-61-225201 (JP, A) JP-A-4-187248 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C08F 8/00- 8/50 C08F 36/06

Claims (6)

(57) [Claims] The following steps: (1) hydroformylating syndiotactic 1,2-polybutadiene in an organic medium, wherein the syndiotactic 1,2-polybutadiene has a particle size of about 250 microns or less. Suspended in the organic medium in the form of small particles, and wherein the syndiotactic 1,2-
Polybutadiene is formyl syndiotactic 1,2-
In the presence of hydrogen, carbon monoxide and a hydroformylation catalyst to form polybutadiene, from about 25 ° C to about 1 ° C.
A temperature in the range of 50 ° C. and at least about 1.013 × 1
0 ⁵ is hydroformylated at a pressure of Pascal: and
(2) forming the carboxylated syndiotactic 1,2-polybutadiene by reacting the formyl syndiotactic 1,2-polybutadiene with oxygen; Production method. 2. The hydroformylation catalyst is selected from the group consisting of hydride carbonyl tris (triphenylphosphine) cobalt, hydride carbonyl tris (triphenylphosphine) rhodium, hydride carbonyl tris (triphenylphosphine) iridium and cobalt carbonyl. Item 7. The method according to Item 1. 3. The method of claim 1 wherein said hydroformylation catalyst is hydride carbonyl tris (triphenylphosphine) rhodium. 4. The hydroformylation reaction is carried out at a temperature in the range of about 65 ° C. to about 100 ° C. and a pressure in the range of about 1.4 × 10 ⁶ Pascal to about 6.9 × 10 ⁶ Pascal. Item 3. The method according to Item 3. 5. The method of claim 1, wherein said small particles have a particle size of less than about 177 microns. 6. The method of claim 4, wherein said small particles have a particle size of less than about 105 microns.