JPH07247303A - Method for hydrogenating unsaturated polyhydroxyhydrocarbon polymer - Google Patents

Abstract

PURPOSE:To provide a method for hydrogenating an unsatd. polyhydroxyhydrocarbon polymer which can be executed industrially advantageously in the presence of a hydrogenation catalyst and a reaction solvent by keeping the water content in the reaction system at a specified value or lower. CONSTITUTION:The water content of the reaction system is kept at 2wt.% or lower in hydrogenating an unsatd. polyhydroxyhydrocarbon polymer in the presence of a hydrogenation catalyst and a reaction solvent by using the reaction solvent, the polymer, and the catalyst each having a low water content. The polymer has carbon-carbon double bonds in the main chain or side chains and on average at least 1.1 hydroxyl groups in the molecule, an esp. suitable example being a polyhydroxypolybutadiene. A ruthenium catalyst is an esp. pref. metal catalyst.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for hydrogenating a polyhydroxy unsaturated hydrocarbon polymer. More specifically, it 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 A polyhydroxy unsaturated hydrocarbon polymer having at least one terminal hydroxyl group at its end,
A hydrocarbon-based polymer having a carbon-carbon double bond in the main chain or side chain is inferior in heat resistance, ozone resistance, weather resistance, etc. due to the double bond existing in the molecule, but it is When added, its properties are improved. Japanese Examined 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 hydrogenation catalyst has been proposed.

[0003]

However, when the polyhydroxy unsaturated hydrocarbon polymer is hydrogenated on an industrial scale by the above-mentioned method, the reaction activity of the hydrogenation catalyst is It was found that various changes occurred depending on the water concentration. The present invention is intended to solve the above technical problems, and provides a method for industrially advantageously hydrogenating a polyhydroxy unsaturated hydrocarbon polymer in the presence of a hydrogenation catalyst and a reaction solvent. As a result of intensive studies, it was found that the object can be achieved by keeping the water content in the reaction solution at a specific concentration or less, and the present invention has been completed.

[0004]

SUMMARY OF THE INVENTION However, the gist of the present invention lies in that when a polyhydroxy unsaturated hydrocarbon polymer is subjected to a hydrogenation reaction in the presence of a hydrogenation catalyst and a reaction solvent, a reaction solution A method for hydrogenating a polyhydroxy unsaturated hydrocarbon polymer is characterized in that the water content therein is kept at 2% by weight or less.

The present invention will be described in detail below. <Polyhydroxy unsaturated hydrocarbon-based polymer> In the method of the present invention, the polyhydroxy unsaturated hydrocarbon-based polymer used as a raw material (hereinafter, also referred to as "hydrogenated raw material polymer") is a main molecule. It refers to 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 by various methods. 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 polymerized with 1) hydrogen peroxide as a reaction initiator. And 2) polymerization 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 aroma. Anion polymerization using a complex with a group compound as a catalyst, followed by reaction with alkylene oxide, epichlorohydrin, etc., and treatment with a protic acid such as hydrochloric acid, sulfuric acid, acetic acid, etc. can be carried out.

In this case, the starting conjugated diene-based monomer includes 1,3-butadiene, isoprene, 1,3-pentadiene, chloroprene and the like, and other monomers as a copolymerization component 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 each of the above copolymers having a hydroxy group.
Among them, polyhydroxypolybutadiene, especially 1,2-
Polybutadiene diol is preferred. This is because when this 1,2-polybutadiene diol is used, the hydrogenation catalyst exhibits extremely high activity, and the hydrogenation reaction can be carried out efficiently. When the hydrogenated polyhydroxy unsaturated hydrocarbon polymer obtained by the method of the present invention is used for polyurethane production, the hydrogenated raw material polymer has a number average molecular weight of 500 to 100,000, It 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 hydrogenation catalyst means a catalyst for smoothly carrying out the hydrogenation reaction of the 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), which is conventionally known as a hydrogenation catalyst, cobalt, ruthenium, rhodium, palladium, platinum, and a mixture or alloy catalyst thereof. be able to. Among the above metal catalysts, ruthenium is particularly preferable. When this catalyst is used, the selectivity for hydrogenation reaction is extremely excellent, so without causing hydrogenolysis of the hydroxy group,
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 or 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 (eg, trialkylaluminum, alkyllithium, etc.) can also be used. When the above metal catalyst is used as a carrier-supporting type, the ratio of the catalyst metal to the carrier is 0.01 to 50% by weight, preferably 0.1 to 15% by weight.

<Reaction Solvent> In the present invention, the reaction solvent means a solvent used when the hydrogenation reaction of the hydrogenated raw material polymer is carried out. In the hydrogenation method of the present invention, various conventionally used organic solvents are used as the reaction solvent. Examples of the organic solvent used include aliphatic hydrocarbons such as hexane, heptane, octane, cyclohexane, and methylcyclohexane; aromatic hydrocarbons such as benzene, toluene, xylene; n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, etc. Alcohols; ethers such as diethyl ether, dipropyl ether, and tetrahydrofuran; esters such as ethyl acetate and butyl acetate; and mixed solvents composed of a mixture thereof, but are not limited to those exemplified. It is not something that will be done.

<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 with respect to 100 parts by weight of the hydrogenated raw material polymer. The amount of the hydrogenation catalyst selected and used varies depending on the kind of metal and the amount of metal supported, but is usually selected from the range of 0.01 to 20% by weight based on the hydrogenated raw material polymer. The reaction temperature is in the range of room temperature to 300 ° C., usually 50 to 200 ° C., but preferably 180 ° C. or lower in order to prevent hydrogenolysis of the hydroxy group. As the hydrogen for the hydrogenation reaction, molecular hydrogen is usually used, but a hydrogen-containing gas may 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%. It is necessary to keep it below the weight percent. If the water concentration in the reaction liquid exceeds 2% by weight, the activity of the hydrogenation catalyst will be significantly reduced, not only will the hydrogenation reaction take a long time, but also the hydrogenation polymer having a sufficiently high hydrogenation rate. Because you can't get.

The water content in the reaction solution, which is brought into the reaction system as the water content of the reaction solvent, the hydrogenation raw material and the hydrogenation catalyst, and the water content of the hydrogenation raw material, the solvent, the hydrogenation catalyst, etc. There is water produced by the reaction of oxygen brought into the reaction system with hydrogen for hydrogenation reaction, but the water produced by the reaction is extremely small. Therefore, in the method of the present invention,
Since it is necessary to keep the water concentration in the reaction liquid 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 the reaction solvent, usually, the recovered solvent separated and recovered from the previous hydrogenation reaction solution by vacuum distillation or the like is recycled and used, but water is also recovered at the same time as the solvent at the time of separation by vacuum distillation or the like. Therefore, the water concentration in the recovered solvent gradually increases with repeated recycling,
If this is used as it is, the water concentration in the reaction solution may not be kept 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 water content before it is recycled. As a method for purifying such a recovered solvent, a method using distillation separation, a method using a water adsorbent such as silica gel or molecular sieve, and the like can be used.

According to the method of the present invention, a reaction solvent having a low water content or a recovery solvent which has been purified to remove or reduce water is used, and the water concentration in the reaction solution is adjusted to 2%.
% Or less, substantially in the range of 0.01 to 2% by weight,
By preferably maintaining the content within the range of 0.01 to 1.5% by weight, a hydrogenated product having a sufficiently high hydrogenation rate can be obtained in a short reaction time. In order to obtain a hydrogenated polymer from the reaction solution that has completed the hydrogenation reaction, the catalyst is filtered off 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 a waterproof coating material for a submarine cable or a raw material polyol for producing polyurethane. 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 with a polyolefin resin, it is possible to improve the molding processability such as stretchability and mechanical properties such as impact resistance, and the resulting molded product also has improved paintability and adhesiveness. It becomes a thing.

[0017]

EXAMPLES 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 description of the following Examples unless it exceeds the gist. In the following examples, "%" is based on weight unless otherwise specified. Further, the water concentration of the reaction solvent and the reaction solution, the hydrogenation rate of the obtained hydrogenated polymer, the hydroxy group hydrogenolysis rate, and the hydrogenation rate 90% arrival time 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 reaction was used as a sample and was determined from 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)} . In addition, these iodine values are measured according to JIS K0070. (3) Hydroxy Decomposition Rate of Hydroxy Group (%) The hydrogenated polymer obtained from the reaction solution after completion of the reaction was used as a sample and was determined by the following formula (II).

[0020]

## STR00002 ## Hydroxy group hydrogenolysis rate (%) = (C−D) / C × 100 (II) [wherein, C is a hydroxyl value (mg-KOH / g) of the polybutadiene diol used, D is a hydroxyl value (mg-KOH / g) of the obtained hydrogenated polymer. In addition, these hydroxyl values are measured according to JIS K0070. (4) Time at which hydrogenation rate reaches 90% (minutes) A hydrogenated polymer obtained from a reaction solution sequentially sampled from a reaction system in which the hydrogenation reaction is in progress is used as a sample, and the hydrogenated polymer is sequentially processed by the method of (2) above. The hydrogenation rate was determined, the change in the hydrogenation rate with the passage of reaction time was traced, and the time required for the hydrogenation rate to reach 90% was examined. This 90% hydrogenation rate arrival time 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 an autoclave having a capacity of 200 ml equipped with a heating heater, a stirring mechanism, a thermometer, a pressure accumulator and a constant pressure supply valve. , 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 is 0.01%) 50
g, and carbon-supported ruthenium catalyst (ruthenium supported amount 5%, water content 50% [wet amount standard]) 0.36 g
Was charged and the system was replaced with purified argon. Next, in this system, high-pressure hydrogen gas from the cylinder was dispensed into a pressure accumulator and passed through a constant pressure supply valve set so that the internal pressure of the reaction system was always a constant pressure of 25 kg / cm ² G. The hydrogen gas in the pressure accumulator was supplied. Next, this reaction system was heated to 115 ° C. over about 30 minutes to start the hydrogenation reaction, and the hydrogenation reaction was carried out for 4 hours under this temperature and pressure conditions.

After completion of the reaction, the reaction solution in the system was taken out, its 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 methods described above. In addition, in order to examine the time required for reaching the hydrogenation rate of 90%, the reaction liquid was sequentially sampled at time intervals during the progress of the hydrogenation reaction, and the same treatment as in the reaction liquid after the reaction was performed to obtain a hydrogenated polymer. Obtained. The results are shown in Table 1 together with the water concentration of the reaction solvent used. The hydroxy group hydrogenolysis rate was 1% or less, and the hydroxy group hydrogenolysis did not substantially occur.

Examples 2 and 3 and Comparative Examples 1 and 2 The same as Example 1 except that the reaction solvents used in Example 1 were replaced with the reaction solvents having the water concentrations shown in Table 1. 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 hydrogenation rate with the passage of reaction time was traced, and the time required for reaching 90% hydrogenation rate was examined. The results are also shown in Table 1.
Shown in. The hydroxy group hydrogenolysis rate is 1
% Or less, and hydrogenolysis of the hydroxy group did not substantially occur.

[0024]

[Table 1]

As is clear 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 exhibits extremely high activity and is in a short time. Polymers having a high hydrogenation rate are obtained by the hydrogenation reaction of (Examples 1 to 3). In contrast, the water concentration in the reaction solution is 2
In the case where the amount exceeds 5% by weight (Comparative Examples 1 and 2), the hydrogenation catalyst exhibits significantly lower activity than each Example, and the hydrogenation reaction takes a long time and the polymer having a high hydrogenation rate is used. Can't get

[0026]

According to the method of the present invention, when the polyhydroxy unsaturated hydrocarbon polymer is hydrogenated in the presence of a hydrogenation catalyst and a reaction solvent, the water concentration in the reaction solution is kept at 2% by weight or less. By virtue of this, the activity of the hydrogenation catalyst can be maintained extremely high, so that there is an effect that the hydrogenation reaction of the polyhydroxy unsaturated hydrocarbon polymer can be carried out with good productivity and industrially. Further, when a ruthenium catalyst is used as the hydrogenation catalyst, the hydrogenation reaction to the double bond of the main chain or the side chain can be carried out with good selectivity without substantially causing hydrogenolysis of the hydroxy group. .

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masakazu Goto 3-10, Shiodo, Kurashiki-shi, Okayama Mitsubishi Kasei Co., Ltd. Mizushima Plant

Claims (4)

[Claims] 1. When the polyhydroxy unsaturated hydrocarbon polymer is subjected to a hydrogenation reaction in the presence of a hydrogenation catalyst and a reaction solvent, the water content in the reaction solution is kept at 2% by weight or less. A method for hydrogenating a polyhydroxy unsaturated hydrocarbon polymer. 2. The method according to claim 1, wherein the polyhydroxy unsaturated hydrocarbon polymer is polyhydroxy polybutadiene. 3. The method according to claim 1 or 2, wherein the hydrogenation catalyst is selected from nickel, cobalt, ruthenium, rhodium, palladium, and platinum. 4. The method according to claim 1 or 2, wherein the hydrogenation catalyst is ruthenium.