JP3232860B2 - Hydrogenation method of polyhydroxy unsaturated hydrocarbon polymer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for hydrogenating a polyhydroxy unsaturated hydrocarbon polymer. More specifically, the present invention relates to an improved method for hydrogenating a polyhydroxy unsaturated hydrocarbon polymer in the presence of a hydrogenation catalyst and a reaction solvent.

[0002]

2. Description of the Related Art At least one hydroxyl group at the terminal of a molecule such as a polyhydroxy unsaturated hydrocarbon polymer,
Hydrocarbon polymers having a carbon-carbon double bond in the main chain or side chain are inferior in heat resistance, ozone resistance, weather resistance, etc. due to the double bond present in the molecule. Adding it improves its properties. Japanese Patent Publication No. 61-36002 discloses a polyhydroxy unsaturated hydrocarbon polymer.
A method of hydrogenating in the presence of a reaction solvent and a carrier-supporting type hydrogenation catalyst has been proposed.

[0003]

However, when the hydrogenation of a polyhydroxy unsaturated hydrocarbon polymer is carried out on an industrial scale according to the above-mentioned proposed method, the reaction activity of the hydrogenation catalyst is reduced in the reaction solution. It was found that it varied variously depending on the water concentration. The present invention is intended to solve the above technical problem, and provides a method for hydrogenating a polyhydroxy unsaturated hydrocarbon polymer in an industrially advantageous manner in the presence of a hydrogenation catalyst and a reaction solvent. As a result of intensive studies, the present inventors have found that the object can be achieved by using a specific solvent for the reaction and keeping the water content of the reaction solution at a specific concentration or less, thereby completing the present invention.

[0004]

The gist of the present invention is to carry out a hydrogenation reaction of a polyhydroxy unsaturated hydrocarbon polymer in the presence of a hydrogenation catalyst and a reaction solvent. The method for hydrogenating a polyhydroxy unsaturated hydrocarbon polymer, wherein the solvent is a mixed solvent of an aliphatic hydrocarbon and an alcohol and the water concentration in the reaction solution is kept at 2% by weight or less. Exist.

Hereinafter, the present invention will be described in detail. <Polyhydroxy unsaturated hydrocarbon polymer> In the method of the present invention, a polyhydroxy unsaturated hydrocarbon polymer used as a raw material (hereinafter, also referred to as a "hydrogenated raw material polymer") refers to a main component of the molecule. A hydrocarbon polymer having a carbon-carbon double bond in a chain or a side chain and having an average of 1.1 or more hydroxy groups in the molecule.

The hydrogenated raw material polymer having the above molecular structure is
It can be manufactured in various ways. For example, a conjugated diene-based monomer alone, a mixture of two or more conjugated diene-based monomers, or a mixture of a conjugated diene-based monomer and another monomer copolymerizable therewith is 1) polymerized using hydrogen peroxide as a reaction initiator. 2) a method of polymerizing using another reaction initiator, for example, an azobisisonitrile compound having a functional group; and 3) an alkali metal such as sodium or lithium, or an alkali metal and a polycyclic aromatic compound. Anionic polymerization using a complex with a group compound as a catalyst, followed by reaction with an alkylene oxide, epichlorohydrin, or the like, followed by treatment with a protic acid such as hydrochloric acid, sulfuric acid, acetic acid, or the like.

In this case, the raw material conjugated diene monomer includes 1,3-butadiene, isoprene, 1,3-pentadiene, chloroprene and the like, and the other monomers as copolymerization components include styrene and acrylonitrile. , Acrylic acid, methacrylic acid, acrylic acid ester, methacrylic acid ester and the like. Specific examples of the hydrogenated raw material polymer obtained by the above method include polyhydroxy polybutadiene, polyhydroxy polyisoprene, polyhydroxy poly 1,3-pentadiene, and the above copolymers having a hydroxy group.
Among them, polyhydroxypolybutadiene, especially 1,2-
Polybutadiene diol is preferred. When 1,2-polybutadiene diol is used, the hydrogenation catalyst exhibits extremely high activity, and the hydrogenation reaction can be efficiently performed. When the hydrogenated polyhydroxy unsaturated hydrocarbon polymer obtained by the method of the present invention is used for producing polyurethane, the hydrogenated raw material polymer has a number average molecular weight of 500 to 100,000, The number is preferably in the range of 1,000 to 10,000, and the number of hydroxy groups in the molecule is preferably in the range of 1.8 to 8.0 on average.

<Hydrogenation catalyst> In the present invention, the term "hydrogenation catalyst" refers to a catalyst for smoothly performing the hydrogenation reaction of the above hydrogenated raw material polymer. Examples of the hydrogenation catalyst that can be used in the method of the present invention include nickel (for example, Raney nickel), cobalt, ruthenium, rhodium, palladium, platinum, and mixtures or alloy-based catalysts conventionally known as hydrogenation catalysts. be able to. Of the above metal catalysts, ruthenium is particularly preferred. When this catalyst is used, the selectivity to the hydrogenation reaction is extremely excellent, so that the hydrogenation of the hydroxy group does not occur,
The hydrogenation reaction to the double bond can be selectively and easily performed.

These hydrogenation catalysts can be used alone, as a solid or soluble homogeneous complex, or as a carrier-supported type supported on a carrier such as carbon, silica, and diatomaceous earth. Further, as the hydrogenation catalyst, in addition to the above metal catalyst,
A metal complex obtained by reducing a compound containing nickel, titanium, cobalt, or the like with an organometallic compound (for example, trialkylaluminum, alkyllithium, or the like) can also be used. When the metal catalyst is used as a carrier-supporting type, the ratio of the catalyst metal to the carrier is preferably in the range of 0.01 to 50% by weight, and more preferably 0.1 to 15% by weight.

<Reaction Solvent> In the present invention, the reaction solvent refers to a solvent used when a hydrogenation reaction of the hydrogenated raw material polymer is carried out. In the hydrogenation method of the present invention, a mixed solvent of an aliphatic hydrocarbon and an alcohol is used as a reaction solvent. Aliphatic hydrocarbon solvents that can be used include hexane, heptane, octane, cyclohexane,
Examples of alcohols that can be used include methylcyclohexane and the like, and examples thereof include n-propyl alcohol, isopropyl alcohol, and n-butyl alcohol, but are not limited to these.

<Hydrogenation reaction> In the method of the present invention, the amount of the reaction solvent used in the hydrogenation reaction is usually 30 to 300 parts by weight based on 100 parts by weight of the hydrogenated raw material polymer. The amount of the hydrogenation catalyst to be selected and used varies depending on the type of metal and the amount supported, but is usually selected from the range of 0.01 to 20% by weight based on the hydrogenation raw material polymer. The reaction temperature is in the range of room temperature to 300 ° C., usually 50 to 200 ° C., preferably 180 ° C. or lower in order to prevent hydrogenolysis of the hydroxy group. Normally, molecular hydrogen is used as hydrogen for the hydrogenation reaction, but a hydrogen-containing gas can also be used as long as it does not contain a substance that becomes a catalyst poison. The hydrogen pressure may be either a normal pressure flow system or a pressurized system, and the hydrogenation reaction may be any reaction system such as a fixed bed system or a suspension system.

In the method of the present invention, when the hydrogenated raw material polymer is subjected to a hydrogenation reaction in the presence of a hydrogenation catalyst and a reaction solvent, the water concentration in the reaction solution is 2% by weight or less, preferably 1.5% by weight. It is necessary to keep it below weight%. When the water concentration in the reaction solution exceeds 2% by weight, the activity of the hydrogenation catalyst is remarkably reduced, so that not only a long time is required for the hydrogenation reaction, but also a hydrogenated polymer having a sufficiently high hydrogenation rate. Because you cannot get

The water contained in the reaction solution is taken into the reaction system as the reaction solvent used, the hydrogenation raw material and the water content of the hydrogenation catalyst, and the water contained in the hydrogenation raw material, the solvent, the hydrogenation catalyst, etc. There is water generated by the reaction of oxygen brought into the reaction system with hydrogen for hydrogenation reaction, but the amount of water generated by the reaction is extremely small. Therefore, in the method of the present invention,
From the necessity of keeping the water concentration in the reaction solution within the above range, it is preferable to use a reaction solvent having a low water content, a hydrogenation raw material, and a hydrogenation catalyst.

As a reaction solvent, a recovered solvent separated and recovered from the previous hydrogenation reaction liquid by distillation under reduced pressure or the like is usually recycled. When separation is performed by distillation under reduced pressure or the like, water is also recovered together with the solvent. Therefore, as the recycling use is repeated, the water concentration in the recovered solvent gradually increases,
If this is used as it is, the water concentration in the reaction solution may not be maintained within the above range. In such a case, the recovered solvent used as the reaction solvent is one that has been purified to remove or reduce the amount of water before it is recycled. As a method for purifying such a recovery solvent, a method using distillation separation, a method using a moisture adsorbent such as silica gel, molecular sieve, or the like can be used.

When the method of the present invention is used, a reaction solvent having a low water content or a recovery solvent which has been purified to remove or reduce the water content is used to reduce the water concentration in the reaction solution to 2%.
% By weight or less, substantially in the range of 0.01 to 2% by weight,
By keeping the content within the range of preferably 0.01 to 1.5% by weight, a hydrogenated product having a sufficiently high hydrogenation rate can be obtained in a short reaction time. To obtain a hydrogenated polymer from the reaction solution after the completion of the hydrogenation reaction, the catalyst is filtered from the reaction solution,
The reaction solvent may be distilled and separated from the filtrate.

The hydrogenated polymer obtained by the method of the present invention is excellent in weather resistance, heat resistance and the like, and is suitably used as an electrically insulating molding material for water-stopping coating materials such as submarine cables and a raw material polyol for polyurethane production. can do. Furthermore, this hydrogenated polymer can also be used as a modifier for polyolefin resins such as polypropylene and polyethylene,
By blending this in an appropriate amount to the polyolefin resin, it is possible to improve the moldability such as stretchability and the mechanical properties such as impact resistance, and the obtained molded product is also improved in paintability and adhesion. It will be.

[0017]

Next, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples unless it exceeds the gist thereof. In the following examples, “%” is based on weight unless otherwise specified. The water concentrations of the reaction solvent and the reaction solution, the hydrogenation rate of the obtained hydrogenated polymer, the hydroxy group hydrogenolysis rate, and the time to reach the hydrogenation rate of 90% were measured as follows.

(1) Moisture concentration (%) The reaction solvent used or the reaction solution after the reaction is used as a sample,
It was measured by the Karl Fischer method. (2) Hydrogenation rate (%) The hydrogenated polymer obtained from the reaction solution after the completion of the reaction was used as a sample, and was determined by the following formula (I).

[0019]

[Number 1] hydrogenation rate (%) = (A-B ) / A × 100 (I) [ In the formula, A, iodine value of 1,2-polybutadiene diol was used (g-I ₂ / 100g) There, B shows the obtained hydrogenated polymer having an iodine value _{(g-I 2 / 100g)} . These iodine values are measured according to JIS K0070. (3) Hydrogenolysis rate of hydroxy group (%) A hydrogenated polymer obtained from the reaction solution after the completion of the reaction was used as a sample and determined by the following formula (II).

[0020]

## EQU2 ## Hydrogenolysis ratio of hydroxy group (%) = (CD) / C × 100 (II) [wherein C is a hydroxyl value (mg-KOH / g) of the used polybutadiene diol; D is the hydroxyl value (mg-KOH / g) of the obtained hydrogenated polymer. These hydroxyl values were measured according to JIS K0070. (4) Time to reach 90% hydrogenation rate (minutes) A hydrogenated polymer obtained from a reaction solution sequentially sampled from a reaction system in which a hydrogenation reaction is in progress is used as a sample, and the hydrogenated polymer is sequentially obtained by the method of (2). The degree of hydrogenation was determined, the change in the degree of hydrogenation with the passage of reaction time was followed, and the time required for the degree of hydrogenation to reach 90% was examined. The time at which the hydrogenation rate reaches 90% is an index of the initial activity of the hydrogenation catalyst used, and the shorter the time, the higher the initial activity.

Example 1 A polybutadiene diol (manufactured by Arco. Chem., Trade name: R-45HT) was placed in a 200 ml autoclave equipped with a heating heater, a stirring mechanism, a thermometer, an accumulator, a constant pressure supply valve, and the like. , Number average molecular weight: 2800,
80% 1,4-bond, 20% 1,2-bond, iodine value:
460g-I ₂ / 100g, hydroxyl value: 54mg-KO
H / g) 50 g, mixed solvent of isopropyl alcohol and n-heptane (weight ratio of isopropyl alcohol: n-heptane is 1: 3, water concentration 0.01%) 50
g, and 0.36 g of a ruthenium catalyst supported on carbon (ruthenium supported amount 5%, water content 50% [wet basis])
And the inside of the system was replaced with purified argon. Next, high-pressure hydrogen gas from the cylinder is separated into the pressure accumulator into this system, and is passed through a constant-pressure supply valve set so that the internal pressure of the reaction system is always kept at a constant pressure of 25 kg / cm ² G. Then, hydrogen gas in the accumulator was supplied. Next, the reaction system was heated to 115 ° C. over about 30 minutes to start the hydrogenation reaction, and the hydrogenation reaction was performed at this temperature and pressure for 4 hours.

After the completion of the reaction, the reaction solution in the system was taken out, the water content was measured by the above-mentioned method, the catalyst was filtered off, and the solvent was distilled off under reduced pressure to obtain a hydrogenated polymer. The hydrogenation rate and the hydroxy group hydrogenolysis rate were measured by the above-mentioned methods. In order to examine the time required for the hydrogenation ratio to reach 90%, the reaction solution was sampled sequentially at intervals during the progress of the hydrogenation reaction, and the same treatment as in the reaction solution after the reaction was completed to remove the hydrogenated polymer. Obtained. The results are shown in Table 1 together with the water concentration of the reaction solvent used. In addition, the hydroxy group hydrogenolysis rate was 1% or less, and the hydrogenolysis of the hydroxy group did not substantially occur.

Examples 2 and 3, Comparative Examples 1 and 2 In the examples described in Example 1, the reaction solvents having the water concentrations shown in Table 1 were used instead of the reaction solvents used in the same examples. A hydrogenated polymer was obtained in the same manner as in the examples.
Further, in the same manner as in the same example, while measuring the water concentration of the reaction solution and the hydrogenation rate of the obtained hydrogenated polymer,
The change in the hydrogenation rate with the passage of the reaction time was tracked, and the time to reach the hydrogenation rate of 90% was examined. Table 1 also shows the results.
Shown in In addition, each of the hydroxy group hydrogenolysis rates was 1
% Or less, and hydrogenolysis of the hydroxy group did not substantially occur.

[0024]

[Table 1]

As is evident from Table 1, when the requirements of the method of the present invention are satisfied and the water concentration in the reaction solution is kept at 2% by weight or less, the hydrogenation catalyst shows extremely high activity, , A polymer having a high degree of hydrogenation can be obtained (Examples 1 to 3). On the other hand, when the water concentration in the reaction solution is 2
In the case of a condition exceeding 1% by weight (Comparative Examples 1 and 2), the hydrogenation catalyst shows significantly lower activity than each of the examples, and requires a long time for the hydrogenation reaction and a polymer having a high hydrogenation rate. Can not get.

[0026]

According to the method of the present invention, when a polyhydroxy unsaturated hydrocarbon polymer is hydrogenated in the presence of a hydrogenation catalyst and a reaction solvent, a mixed solvent of an aliphatic hydrocarbon and an alcohol is used. And the water concentration in the reaction solution is 2% by weight.
By keeping it below, the activity of the hydrogenation catalyst can be kept extremely high, so that there is an effect that the hydrogenation reaction of the polyhydroxy unsaturated hydrocarbon polymer can be carried out efficiently and industrially advantageously. When a ruthenium catalyst is used as the hydrogenation catalyst, the hydrogenation reaction to the double bond in the main chain or the side chain can be performed with high selectivity without substantially causing hydrogenolysis of the hydroxy group. .

Continuation of the front page (72) Inventor Masakazu Goto 3-10 Utsudori, Kurashiki-shi, Okayama Prefecture Mizushima Plant, Mitsubishi Kasei Co., Ltd. (56) References JP-A-50-90694 (JP, A) JP-A-4 -108809 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08C 19/02 C08F 8/04

Claims (4)

(57) [Claims] 1. A hydrogenation reaction of a polyhydroxy unsaturated hydrocarbon polymer in the presence of a hydrogenation catalyst and a reaction solvent, the reaction solvent comprising an aliphatic hydrocarbon and an alcohol.
Mixing a solvent and water添方method polyhydroxy unsaturated hydrocarbon polymer which is characterized by keeping the water concentration to 2 wt% or less in the reaction solution. 2. The method according to claim 1, wherein the polyhydroxy unsaturated hydrocarbon polymer is polyhydroxy polybutadiene. 3. The method according to claim 1, wherein the hydrogenation catalyst is selected from nickel, cobalt, ruthenium, rhodium, palladium, and platinum. 4. The method according to claim 1, wherein the hydrogenation catalyst is ruthenium.