JPS6058242B2 - Method for producing hydrogenated conjugated diene polymer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention utilizes a hydrogenation catalyst supported on a powdered silica carrier to produce a hydrogenated conjugated diene polymer in a solution. The bond is hydrogenated, and after the hydrogenation reaction is completed, the hydrogenated conjugated diene polymer is separated and recovered from the solution without separating the carrier-supported catalyst from the solution. The present invention relates to a method for producing a hydrogenated conjugated diene polymer.

Hydrogenation of polymers is carried out in a suspension state in a solution using a carrier-supported catalyst in which a metal or non-metallic hydrogenation catalyst is supported on a carrier such as activated carbon, and after the specified hydrogenation reaction is completed. , by treating the catalyst supported on the carrier used in the hydrogenated polymer solution by appropriate treatment means.

It is common practice to separate and recover the hydrogenated polymer after separation, and for this reason, there is active research into carriers that are easy to separate. The purpose of this is to recover and reuse metal or non-metallic catalysts, and also to prevent some catalyst elements from remaining in the hydrogenated polymer and causing adverse effects such as deterioration on the polymer. It's also for a reason.

In addition, the carrier used is usually treated to increase the particle size in order to facilitate separation. Therefore, if a carrier with a large particle size remains in the hydrogenated polymer, it will cause a significant decrease in the strength properties of the vulcanized polymer, so it is essential to separate the carrier along with the catalyst element. There is. Filtration methods using various filters or centrifugation methods are often used to separate the carrier-supported catalyst from the reaction system, but in the case of hydrogenation of polymers, it is different from the case of hydrogenation of low-molecular compounds. In contrast, the separation of supported catalysts is very difficult due to the high viscosity of the reaction system.

If a large amount of solvent is added to dilute the reaction system, the viscosity of the reaction system will decrease, and if a carrier with a large particle size is used, it will be easier to separate the catalyst, but if a carrier with a small particle size is used, the filtration aid will be reduced. The use of a large amount of solvent causes problems such as a large amount of thermal energy being consumed for recovery and purification of the solvent and the difficulty in separating the filter aid from the catalyst. If a carrier with a small particle size is used, the catalytic activity will improve, but separation will be difficult. Generally, there are performance requirements that conflict with separability.

Therefore, at present, great efforts are being made to develop supports that facilitate separation without reducing catalytic activity. Powdered carbon black, which is used as a reinforcing agent and coloring agent in Com Industries, Plastic Industries, etc., is used as a carrier, and after the completion of the hydrogenation reaction, the catalyst supported on the carrier is not separated and removed from the reaction solution. We discovered a method for recovering a hydrogenated polymer containing a catalyst supported on a carrier by treating it as it is, and filed a patent application.

However, when the hydrogenation reaction is carried out using carbon black as a carrier, the diene rubber is adsorbed to the surface of the carbon black during the hydrogenation reaction because carbon black has a high affinity with diene rubber, and while stirring, the carbon black It has been found that the comrades coagulate to form a strong agglomerate of several tens to several hundred p, and if this remains in the hydrogenated rubber, it has an adverse effect on the vulcanization properties of the rubber.

The present inventors have worked diligently to solve this problem, and as a result, have arrived at the present invention.

An object of the present invention is to provide a method for producing a hydrogenated conjugated diene polymer that does not require separation of a carrier-supported catalyst. Hydrogenating the carbon-carbon double bond of a conjugated diene polymer in a solution using a carrier-supported catalyst in which a hydrogenation metal or non-metallic catalyst is supported on a specific powdered silica carrier,
This is achieved by using a method of isolating the hydrogenated conjugated diene polymer without separating the used carrier-supported catalyst from the hydrogenated polymer solution after the hydrogenation reaction is completed.

In the method of the present invention, there is no aggregation of the carrier during the hydrogenation reaction and there is no need to use a large amount of solvent for dilution, so the recovery and purification of the solvent is easy, and there is no need to separate the catalyst supported on the carrier. There is no need to use a decanter, centrifuge, etc. Since various equipment such as a filter for separating the carrier catalyst is not required at all, the hydrogenation production process is greatly simplified, and there are great economic advantages.

There are no restrictions on the particle size of the silica used for the support other than considering the maximum allowable particle size, so by using silica with the smallest possible particle size, it is possible to use silica as a highly active catalyst for hydrogenation. A reaction can be carried out. The silica carrier used in the present invention is preferably one with an average particle size of 10p or less in view of catalytic activity and remaining in the hydrogenated polymer.If silica with an average particle size of 10p or more remains in the hydrogenated polymer Significantly reduces the strength properties of vulcanized polymers.

The silica used in the present invention exhibits catalytic activity and is not particularly limited as long as it has a particle size within the above range, but it is generally used as a reinforcing agent for silica gel, silica sol, rubber, resin, etc. Silica used in fillers for latex, silica for adhesives, paints, and inks, silica for thickeners, silica for paper coating,
These include silica for water dispersion, silica for thin layer chromatographs, column chromatographs, gas chromatographs, and liquid chromatographs. The hydrogenation catalyst used in the present invention may be any metal or non-metallic catalyst having hydrogenation activity, and is not particularly limited as long as it does not have an adverse effect even if it remains in the polymer after hydrogenation.

Specifically, Fe, CO, Ni, Ru, Rh, Pd, Ir
,Os,Pt,Cr,Te,Mn,Ti,■,Zr,M
Examples include O, W, etc. These metals can be used alone or in combination. Furthermore, the present inventors have previously filed a partial application for Pd and periodic table 1a, ■A, ■A, b.
, ■A, b, ■A, ■A, ■a group metals or non-metallic catalysts such as Ag, Au, Sb, Te, etc. are also preferred due to their high activity.

Pd-based catalysts are particularly preferred from the viewpoints of hydrogenation efficiency, absence of adverse effects of residual catalyst on the hydrogenated polymer, and the like. The metal or nonmetal can be supported on the silica support by using a conventional method for preparing a catalyst supported on a carrier. For example, the metal or nonmetal element itself or an aqueous solution of various salts of these elements can be added to the silica support. A silica-supported catalyst can be obtained by impregnating a carrier and then reducing it. The amount of catalyst metal and/or nonmetal supported on the carrier is 0.00 per carrier.
The amount of saliva is 1 to 3%, preferably 0.01 to 1%.

The amount of the catalyst to be used may be appropriately determined within the above range depending on the type of polymer to be hydrogenated and the target hydrogenation rate. From the viewpoint of influence on various properties, the amount is 2000 ppm or less, preferably 1000 ppm or less per polymer.

In the conjugated diene polymer used in the present invention, the conjugated diene monomer is one or more monomers selected from 1,3-butadiene, 2,3-dimethylbutadiene, isoprene, 1,3-pentadiene, etc. 10 out of all monomers
~10% by weight of ethylenically unsaturated monomers such as unsaturated nitriles such as acrylonitrile, methacrylonitrile, etc., monovinylidene aromatic hydrocarbons such as styrene, alkylstyrenes (0-, m- and p-methylstyrene, ethylstyrene, etc.) unsaturated carboxylic acids or esters thereof, such as acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid, or methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, etc. A conjugated diene polymer composed of one or more monomers selected from vinyl pyridine and vinyl esters, such as vinyl acetate, in an amount of 0 to 9% by weight based on the total monomers, and manufactured by solution polymerization, emulsion polymerization, etc. Ru.

Typical conjugated diene polymers include polybutadiene,
Examples include polyisoprene, butadiene-styrene (random and block) copolymers, and acrylonitrile-butadiene (random and alternating) copolymers. When using a polymer polymerized by solution polymerization, the hydrogenation reaction is carried out in the form of a solution of the polymer as it is, and when using a solid polymer, it is carried out in the form of a solution dissolved in a solvent.

The concentration of the polymer solution is 1 to 7% by volume, preferably 1 to 4% by volume. As a solvent, it does not adversely affect the catalyst.
There is no particular restriction as long as it dissolves the polymer to be hydrogenated, and benzene, toluene, xylene, hexane, cyclohexane, tetrahydrofuran, acetone, methyl ethyl ketone, ethyl acetate, cyclohexanone, and the like can be used. The reaction temperature is 0 to 300°C, preferably 20°C.
~150°C.

Temperatures above 150°C are acceptable, but side reactions may occur.
Undesirable for selective hydrogenation reactions.

For example, hydrogenation of the solvent or hydrogenation of ethylenically unsaturated monomer units in the polymer, such as the nitrile group of acrylonitrile or the benzene nucleus of styrene, occurs. The hydrogen pressure is in the range of atmospheric pressure to 300 kg/Clt, preferably 5 to 200 k9/C! It is l.

Although a high pressure of 300k9/C7lf or higher is acceptable, there are major factors that hinder practical application, such as increased equipment costs and troublesome handling.

After the hydrogenation reaction is completed, the hydrogenated polymer can be separated from the hydrogenated polymer solution containing the carrier-supported catalyst by simply using the method normally used to recover the polymer from the polymer solution. These methods include a steam coagulation method in which the polymer solution is brought into direct contact with water vapor, a drum drying method in which the polymer solution is dropped onto a heated rotating drum to evaporate the solvent, and a poor solvent is added to the polymer solution to precipitate the polymer. Methods and the like are exemplified.

By using such a polymer separation method, a hydrogenated polymer containing a carrier-supported catalyst is separated from a solution, and solid hydrogen is obtained through a drying process such as draining, hot air drying, vacuum drying, or extrusion drying. It is recovered as a chemical polymer. The hydrogenated conjugated diene polymer containing the carrier-supported catalyst of the present invention has no difference in performance from the hydrogenated conjugated diene polymer that does not contain the catalyst, and can be used in a wide range of fields depending on the properties of the polymer. I can row.

The present invention will be specifically explained below with reference to Examples, but the present invention is not limited to the following Examples unless it exceeds the gist thereof.

The average particle size of silica was determined from a particle size distribution curve by direct measurement of an electron micrograph.

The specific surface area was calculated by measuring the amount of nitrogen absorbed by a low-temperature nitrogen adsorption method and using the BET formula. The hydrogenation rate of carbon-carbon double bonds was measured by the iodine value method. Example 1 0.775k9 of acrylonitrile-butadiene copolymer (bound acrylonitrile amount: 39.4% by weight, ■71+4,100°C=53) and 4.25kg of acetone were charged into an autoclave with a capacity of 10e, and the polymer was dissolved. After that, silica product of Tamoto Aerosil Co., Ltd. with an average particle size of 8mp,
Aerosil 300. Catalyst 22 using a carrier with a specific surface area of 300 i/y and supporting 2% by weight of Pd on the carrier.
．． 5y (equivalent to 3 parts by weight of catalyst per 10 parts of polymer, P
Silica was immersed in a dce2 aqueous solution, dried, and then reduced with formalin-caustic soda). After purging the system with nitrogen, the reaction was carried out at a hydrogen pressure of 50 kg/C7lf and 50° C. for 5 hours.

The hydrogenation rate was 87.8%. Furthermore, no aggregation of the silica carrier was observed during the reaction. After the reaction was completed, the solution was divided into two parts, and one part was directly blown into the polymer solution to separate the catalyst after the reaction to obtain grams, which were dried under reduced pressure (sample NO.
．． l).

On the other hand, the remainder was diluted with a large amount of solvent (acetone), the catalyst was separated using a centrifuge, water vapor was directly blown into the polymer solution to obtain grams, and the polymer solution was dried under reduced pressure (Sample Group 2). These two types of hydrogenated polymers were mixed on a roll according to the formulation shown in Table 1 to obtain a rubber compound, and a vulcanizate was prepared by pressurizing and heating the two powders at 155°C. .

Physical properties of the vulcanizate were measured in accordance with JISK-6301. The reinforcing carbon black was added on a roll by subtracting the amount of silica carrier remaining in the hydrogenated polymer from the total amount of carbon black. Table 1 Example 2 Silica (average particle size 22 wLp,
Specific surface area 143d/Y. ．． PPG product, Hysil 23
3) was used as a carrier, and a catalyst supporting 5% by weight of Pd on the carrier was prepared using an acrylonitrile-butadiene copolymer (bonded acrylonitrile amount: 45.0% by weight, ML, l+41
Hydrogenation reaction was carried out using 1 part by weight per 100 parts by weight (00°C=50) at a hydrogen pressure of 50k9/d, a reaction temperature of 50°C, and a reaction time of 6 hours.

The hydrogenation rate was 90.3%. Also in this example, no aggregation of silica occurred during the reaction. A portion of the product was coagulated with steam and dried without separating the catalyst after the reaction (Sample No. 3). The rest are sample no. After separating the catalyst in the same manner as in 2, it was coagulated and dried (sample No. 4). These two types of hydrogenated polymers were made into vulcanizates using the same formulations (Table 1) and vulcanization conditions as in Example 1. Example 3 Silica (average particle diameter 2μ, specific surface area 260d) was prepared in the same manner as in Example 1.
/f1 Mizusawa Chemical Co., Ltd. product Silton A-2) was used as a carrier, and a catalyst with 3% by weight of Pd supported on the carrier was mixed with an acrylonitrile-butadiene copolymer (bonded acrylonitrile amount: 45.0% by weight, MLl+, 100 ℃=50)10
Using 1 part by weight per weighing part, hydrogen pressure 60k9/Cl,
The hydrogenation reaction was carried out at a reaction temperature of 50° C. and a reaction time of 8 hours.

The hydrogenation rate was 93.5%. After the reaction, a part of the product is
The catalyst was directly coagulated with steam and dried without separating it (sample No. 5). The rest are sample NL). The catalyst was separated in the same manner as in 2, followed by steam coagulation and drying (sample No. 6). These two types of hydrogenated polymers were made into vulcanizates using the same formulations (Table 1) and vulcanization conditions as in Example 1. Example 4 In the same manner as in Example 1, silica (Silica Gel 40 manufactured by Wako Pure Chemical Industries, Ltd. was classified and used had an average particle diameter of 3 μm, specific surface area 650 Wt/f) as a carrier, and 4% by weight of P was added.
The catalyst on which d was supported was acrylonitrile-butadiene copolymer (bound acrylonitrile amount 37.0% by weight, ML
l+4100℃=50.5) Using 2 parts by weight per 100 parts by weight, hydrogen pressure 50k9/Cllll reaction temperature 50℃,
The hydrogenation reaction was carried out for a reaction time of 3 hours.

The hydrogenation rate of double bonds was 85.3%. A portion of the product was steam-coagulated and dried without separating the catalyst after the reaction (Sample No. 7). The remaining catalyst was separated from the catalyst in the same manner as in Example 1, coagulated with steam, and dried (Sample 1S!
0.8). These two types of hydrogenated polymers were made into a vulcanized product using the same formulation (Table 1) and vulcanization conditions as in Example 1. Comparative Example 1 In the same manner as in Example 1, silica (Silica Gel 40 manufactured by Wako Pure Chemical Industries, Ltd. was classified and used 7 particles with an average particle diameter of 30 p, specific surface area 650 i/y) was used as a carrier, and silica was used as a carrier.
Using 2 parts by weight of a catalyst supporting % by weight of Pd per 10 parts by weight of acrylonitrile-butadiene copolymer (amount of bound acrylonitrile 37.0% by weight, MLl + 4100°C = 50), hydrogen pressure 50k9/') C7lT, The hydrogenation reaction was carried out at a reaction temperature of 50° C. and a reaction time of 3 hours.

The hydrogenation rate of double bonds was 82.1%. A portion of the product was steam-coagulated and dried without separating the catalyst after the reaction (Sample No. 9). The rest is the same as in Example 1,
After separating the catalyst, it was coagulated with steam and dried (sample no.
．． lO). These two types of hydrogenated polymers were made into vulcanizates using the same formulation (Table 1) and vulcanization conditions as in Example 1.

Table 2 shows the strength characteristics of the vulcanizates of Samples 1 to 10 above.

As is clear from Table 2, when silica having an average particle diameter within the range of the present invention is used as a catalyst carrier, even if the catalyst used is mixed into the polymer without being separated, the physical properties are not affected.

However, when silica outside the scope of the present invention is used as a carrier, the strength properties of the vulcanizate are poor unless the catalyst used is separated. In addition, for these types of sulfuric materials, 7 at 150°C
The hydrogenated polymer of the present invention, in which the catalytic metal remains in the hydrogenated polymer, has a heat resistance that is no different from that of the hydrogenated polymer from which the catalytic metal has been removed. showed his sexuality.

Example 5 Polybutadiene (98% cis-1.4 content) as a polymer
ML, f,,OO℃=40), styrene-butadiene copolymer (bound styrene content 23.5% by weight, MLI cha.1
00° C.=50) and polyisoprene (98% cis-1.4 content, ML,.,.

, OO°C=80), and each polymer was dissolved in cyclohexane to a concentration of w weight %. 3% by weight of Pd was added to Hysil 23 and silica gel used in Example 1.
Hydrogenation was carried out at 90°C for 3 hours (3 parts by weight of catalyst supported on the carrier/1 part by weight of polymer, hydrogen pressure 40k9/d). The results are shown in Table 3.

Claims (1)

[Claims] 1. When producing a hydrogenated conjugated diene polymer, a hydrogenation catalyst is supported on a powdered silica carrier with an average particle size of 10μ or less, and the carbon-carbon of the conjugated diene polymer is prepared in a solution. Hydrogen, characterized in that carbon double bonds are hydrogenated, and after the hydrogenation reaction is completed, the hydrogenated conjugated diene polymer is separated and recovered without separating the carrier-supported catalyst from the solution of the hydrogenated conjugated diene polymer. A method for producing a conjugated diene polymer.