JPS6261201B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing hydrogenated petroleum resins. More specifically, when hydrogenating petroleum resins containing aromatic nuclei, hydrogen gas and petroleum resins containing molten aromatic nuclei are introduced from the top of the reactor in parallel flow under the filling of a fixed bed catalyst supporting a specific metal. The present invention relates to a method for producing hydrogenated petroleum resin, which is characterized by continuously hydrogenating the resin by flowing it downward. The so-called petroleum resin obtained by polymerizing the thermal decomposition product of petroleum naphtha in the presence of a Friedel-Crafts catalyst is mainly used as a tackifier for pressure-sensitive adhesives or adhesives, a modifier for plastic compounding, etc. Resins suitable for these uses usually have a softening point of 60 to 140°C and a molecular weight of about 600 to 10,000. Above all, these hydrogenated petroleum resins have good weather resistance, color tone, stability, and compatibility with rubber, polyolefin, ethylene-vinyl acetate copolymer, etc., so they are suitable as resins for use in the above applications. Especially excellent. However, the petroleum resin subjected to the above-mentioned hydrogenation is much less likely to be hydrogenated than its raw material monomer. The reason for this has not yet been fully elucidated, but in general, hydrogenation becomes more difficult as the degree of polymerization increases. In particular, when converting the benzene ring of a petroleum resin having an aromatic ring to a cyclohexane ring, a large amount of catalyst is added,
The hydrogenation reaction is difficult to proceed unless it is under severe conditions of high temperature, high pressure, and long time. Powdered nickel catalysts or platinum catalysts have been known as catalysts used in the hydrogenation reaction of petroleum resins. As a hydrogenation method, a batch suspension bed system or a flow suspension bubble column system is generally employed. When hydrogenating by this conventional method, an overstep is essential to separate the hydrogenated petroleum resin and the powdered catalyst after the hydrogenation. Moreover, among the above-mentioned petroleum resins, those with high softening points, that is, those with high viscosity, are difficult to melt and have inconveniences in handling, such as a delay in elapsed time. The desired hydrogenated petroleum resin can only be obtained by diluting it once with an organic solvent such as, passing through a catalyst, and then evaporating the solvent from the liquid. Therefore, the production process is extremely complicated, and it also leads to an increase in product cost, which is undesirable. In particular, when a platinum catalyst is used as the catalyst in the conventional method, the catalyst is very expensive and therefore the catalyst cannot be quantitatively recovered, resulting in a large economic loss. In view of these problems, there is a strong desire to establish a hydrogenation process for petroleum resins using a fixed bed from an industrial and economic standpoint such as resource and energy conservation. The present inventors have solved the problems of the prior art.
As a result of intensive research to develop a new and extremely streamlined continuous hydrogenation process for petroleum resins that eliminates the evaporation step, we have developed a system that uses a reactor filled with a fixed bed catalyst supporting specific metals. The present inventors have discovered that all the drawbacks of the prior art can be overcome and the above objectives can be achieved by adopting the flow down method, and have completed the present invention. That is, in hydrogenating a petroleum resin having an aromatic nucleus, the present invention uses at least one selected from the group consisting of () platinum and (or) rhodium, or () platinum and (or) rhodium () palladium, ruthenium, and rhenium.
Hydrogenated petroleum characterized by continuous hydrogenation by flowing hydrogen gas and molten petroleum resin downward in parallel flow from the upper part of the reactor under the filling of a fixed bed catalyst supporting a certain metal. Concerning a method for producing resin. In the present invention, the petroleum resin having an aromatic nucleus refers to an aromatic hydrocarbon having a double bond in its side chain, a homopolymer of an aromatic hydrocarbon having a double bond in a condensed ring, or a mixture of the aromatic hydrocarbon and other aromatic hydrocarbons. It refers to a polymer of a mixture consisting of olefins and can be obtained by polymerizing the following components in the presence of a Friedel-Crafts catalyst such as aluminum chloride or boron trifluoride. Examples of aromatic hydrocarbons include stethylene, α-methylstyrene, vinyltoluene, vinylxylene, propenylbenzene, indene, methylindene, and ethylendene. Examples of olefins include butene, bentene, hexene, heptene, octene,
Examples include butadiene, pentadiene, cyclopentadiene, dicyclopentadiene, and octadiene. The catalyst used in the present invention needs to be a fixed bed catalyst supporting a specific metal. This is because, as mentioned above, petroleum resins, especially petroleum resins having aromatic nuclei, are difficult to hydrogenate and therefore require a highly active catalyst. On the other hand, the petroleum resin usually contains 100 to 500 ppm of sulfur, which acts as a catalyst poison and shortens the catalyst life. Toxicity is also an important factor for the catalyst of the present invention. As a result of examining the above two types of factors,
Surprisingly, very satisfactory results have been obtained using fixed bed catalysts supported on platinum and/or rhodium. A fixed bed catalyst obtained by combining platinum and/or rhodium with a metal such as palladium, ruthenium or rhenium can also be suitably used. That is, by adding at least one metal selected from the group consisting of palladium, ruthenium, and rhenium to platinum and/or rhodium, the activity is slightly lower than when platinum and/or rhodium are used alone. It is effective in extending the life of the catalyst due to the heat resistance effect based on the prevention of sintering of platinum and rhodium. Although knowledge regarding catalyst poisoning has not been elucidated in detail, in the present invention, clear differences were confirmed between platinum and/or rhodium catalysts and nickel catalysts. That is, when a nickel catalyst is used, catalyst deterioration occurs due to sulfur being adsorbed onto the catalyst very quickly or reacting with sulfur to produce nickel sulfide. On the other hand, when a platinum and/or rhodium catalyst was used, sulfur was hydrogenolyzed to become hydrogen sulfide, which was removed from the catalyst layer together with hydrogen gas, so it was not accumulated on the catalyst. That is, the catalyst of the present invention is a fixed bed catalyst supporting at least one member selected from the group consisting of () platinum and/or rhodium, or () platinum and/or rhodium and () palladium, ruthenium, and rhenium. can be given. The amount of platinum and rhodium supported, alone or in combination, is preferably 0.2 to 10% by weight (hereinafter referred to as %), preferably 0.5 to 5%, based on the weight of the support. The supported amount of the metal in () above can be used in combination up to the total weight of the supported amount with the supported amount in () satisfying the above range with respect to the carrier weight and up to the same weight as the above (). The carrier used is not particularly limited, but
Porous materials with large surface areas such as alumina, silica, carbon, and titania are preferred. The shape of the catalyst used may be cylindrical, extrudate, pellet, or spherical, but spherical is particularly preferred. The size of the catalyst is better as it affects the effective activity of the catalyst, but considering the pressure loss that occurs in the reactor due to catalyst filling, it is recommended to use a sphere with a diameter of 0.3 to 8 mm, preferably 0.6 to 3 mm. good. The manufacturing method of the present invention involves causing a liquid phase made of a molten petroleum resin to drip downwardly onto the packed bed of the fixing catalyst, and forming a thin film of petroleum resin on the surface of the catalyst. This method employs the so-called trickle bed method in which hydrogen is efficiently added in the phase. The reaction conditions of the present invention are determined appropriately taking into consideration the hydrogenation rate, reaction time, reactor specifications, etc., but the reaction pressure is usually 30 to 300 Kg/cm ² ,
Preferably it is 50 to 150 Kg/cm ² . The amount of hydrogen supplied is 2 to 50 times, preferably 2 to 30 times, the theoretical absorption amount of petroleum resin, and the reaction temperature is 200 to 350°C, preferably
The temperature is preferably 230 to 320°C. In addition, the supply amount of petroleum resin is determined by WHSV (Weight Hourly Space Velocity).
The ratio (weight of petroleum resin supplied per hour/weight of catalyst packed) is 0.01 to 10, preferably 0.05 to 2. As mentioned above, according to the manufacturing method of the present invention,
By melting petroleum resin under high temperature and lowering it from the top of the reactor, a thin film of petroleum resin is formed on the catalyst surface, and hydrogen gas, which is a continuous phase, is efficiently brought into contact with this film and diffused. The reaction time can be shortened and the hydrogenation rate can be improved compared to the suspended bed system or the suspended bubble column system. Next, the present invention will be specifically explained with reference to Examples. Example 1 A reactor with a length of 2 m, an internal diameter of 26 mm, and an internal volume of 1 was used.The outside of the reactor was heated with a cast-in brass heater, and four blocks were installed to keep the internal temperature constant. The temperature can be adjusted by dividing it into two sections.
The upper part of the reactor was filled with 200 ml of stainless steel for preheating, and 500 g of spherical 2% platinum-alumina catalyst (manufactured by Nippon Engelhard Co., Ltd.) with a particle size of 1.5 mm was fixed and placed at the bottom. . Maintain the inside of the reactor at a temperature of 295-305℃ and a pressure of 100Kg/ ^cm2 ,
Hydrogen gas supply rate 150N/hr and petroleum resin ("Petrosine #120", softening point 120℃, sulfur content
Hydrogenation was carried out by flowing down from the top of the reactor at a feed rate of 150 g/hr (150 ppm, aromatic nucleus content 54%, manufactured by Mitsui Petrochemicals Co., Ltd.). Then, after separating gas and liquid in a separator, the hydrogenated petroleum resin was taken out of the reaction system. Note that since the above-mentioned apparatus was a bench scale, hydrogen gas was not circulated. Next, continuous operation was performed to confirm the catalyst activity and catalyst life, and the analysis results of the hydrogenated petroleum resin obtained after each time period are shown in Table 1.

[Table] As is clear from Table 1, the catalyst did not deteriorate despite continuous hydrogenation reaction for 3000 hours and maintained a high hydrogenation rate of approximately 90%, but after 4000 hours the hydrogenation rate decreased to 70%. %, indicating a tendency for catalyst deterioration. Note that the hydrogenation rate was determined by the following measurement method. That is, the absorbance at 274.5 nm was measured using an ultraviolet spectrometer, and the hydrogenation rate was calculated using the following formula. A-B/A×100 (%) (In the formula, A indicates the absorbance of the raw petroleum resin, and B indicates the absorbance of the hydrogenated petroleum resin.) Examples 2 to 5 The platinum catalyst of Example 1 is shown in Table 2. Hydrogenation was carried out in the same manner as in Example 1 except that the catalysts shown were used instead. The analysis results of the obtained hydrogenated petroleum resin were analyzed in the second
Shown in the table.

[Table] As is clear from the results in Table 2, in Examples 2 and 3, the hydrogenation rate decreased after 4000 hours, and a tendency for catalyst deterioration was observed. On the other hand, in Examples 4 and 5, when catalysts containing ruthenium or palladium were used, there was almost no decrease in the hydrogenation rate even after 4000 hours had passed, and the effect of extending the life of the catalyst was clearly observed.

Claims (1)

[Scope of Claims] 1. In hydrogenating petroleum resins having aromatic nuclei, a fixed bed catalyst supporting () platinum and/or rhodium is charged into a reactor and fused with hydrogen gas from the upper part of the reactor. 1. A method for producing hydrogenated petroleum resin, which comprises flowing the petroleum resin downward in cocurrent with the petroleum resin and continuously hydrogenating the resin. 2. When hydrogenating petroleum resins having aromatic nuclei, a fixed bed catalyst supporting () platinum and/or rhodium and () at least one metal selected from the group consisting of palladium, ruthenium, and rhenium is reacted. 1. A method for producing hydrogenated petroleum resin, which comprises filling a reactor and causing hydrogen gas and molten petroleum resin to flow downward from the upper part of the reactor in cocurrent flow to perform hydrogenation continuously.