JPS6261202B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing hydrogenated petroleum resins. More specifically, when hydrogenating a petroleum resin containing aromatic nuclei, hydrogen gas and petroleum resin containing molten aromatic nuclei are flowed together from the bottom of the reactor under a fixed bed catalyst supporting a specific metal. The present invention relates to a method for producing a hydrogenated petroleum resin, which is characterized by flowing the resin upwardly and performing hydrogenation continuously. 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 the 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 saving and energy saving. The present inventors have solved the problems of the prior art.
As a result of intensive research to develop a new and highly streamlined continuous hydrogenation process for petroleum resins that eliminates the evaporation process, we have developed a method that uses a reactor filled with a fixed bed catalyst supporting specific metals. The inventors have discovered that by employing the method described above, all the drawbacks of the prior art can be solved and the above object can be achieved, and the present invention has been completed. That is, in hydrogenating a petroleum resin having an aromatic nucleus, the present invention processes hydrogen gas and molten petroleum resin in parallel flow from the lower part of a reactor while filling a fixed bed catalyst supporting platinum and/or rhodium. The present invention relates to a method for producing hydrogenated petroleum resin, which is characterized by flowing upward and performing hydrogenation continuously. 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 styrene,
Examples include α-methylstyrene, vinyltoluene, vinylxylene, propenylbenzene, indene, methylindene, and ethylindene. Examples of olefins include butene, pentene, hexene, heptene, octene, butadiene, pentadiene, cyclopentadiene, dicyclopentadiene, octadiene, and the like. 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 were obtained when using fixed bed catalysts loaded with platinum and/or 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, examples of the catalyst of the present invention include a fixing catalyst supporting platinum and/or rhodium. The supported amount of platinum and rhodium is 0.2 to 10% by weight (hereinafter referred to as %) based on the carrier weight, either alone or in combination.
), preferably 0.5 to 5%. 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 performance of the catalyst, but considering the pressure loss that occurs in the reactor due to catalyst filling, it is better to use a spherical shape with a diameter of 0.3 to 8 mm, preferably 0.6 to 3 mm. . The production method of the present invention involves introducing molten petroleum resin from below into the packed bed of the fixed bed catalyst, and then flowing hydrogen gas in the form of fine bubbles to efficiently hydrogenate the catalyst on the catalyst surface, so-called gas-liquid upward parallel flow. This method is adopted. 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 50-150Kg/ ^cm2 . The amount of hydrogen supplied is 2 to 50 times, preferably 5 to 30 times, the theoretical hydrogen 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,
The reaction time can be shortened and the hydrogenation rate can be improved compared to the conventional batch-type suspended bed method or flow-type suspended bubble column method. Next, the present invention will be specifically explained with reference to Examples. Example 1 A reactor with a length of 2 m, an inner diameter of 26 mm, and an internal volume of 1 was used, and the outside of the reactor was heated with a heater.
In order to keep the internal temperature constant, it was divided into four blocks so that the temperature could be adjusted. The lower part of the reactor was filled with 200 ml of stainless steel for preheating, and the upper part was filled with a spherical 2% platinum-alumina catalyst with a particle size of 1.5 mm (manufactured by Nippon Engelhard Co., Ltd.).
500g was fixed and placed. Temperature inside the reactor: 295~
Maintained at 305℃, pressure 100Kg/ ^cm2 , hydrogen gas supply amount
750N/hr and petroleum resin ("Petrozin #120", softening point 120℃, sulfur content 150ppm, aromatic nucleus content 54%, manufactured by Mitsui Petrochemical Co., Ltd.) supply amount
Hydrogenation was carried out by flowing upward from the bottom of the reactor at a rate of 150 g/hr. 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 hydrogenation rate of approximately 80%, but after 4000 hours the hydrogenation rate decreased to approximately 60%. %, 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.) Example 2 The platinum catalyst of Example 1 was replaced with a 2% rhodium-alumina catalyst. Hydrogenation was carried out in the same manner as in Example 1 except that . The analysis results of the obtained hydrogenated petroleum resin are shown in Table 2.

[Table] As is clear from the results in Table 2, catalyst deterioration did not occur despite continuous hydrogenation reaction for 3000 hours and the hydrogenation rate was maintained at approximately 80%, but after 4000 hours the hydrogenation rate decreased. It decreased to about 60%, indicating a tendency for catalyst deterioration.

Claims (1)

[Claims] 1. When hydrogenating petroleum resins having aromatic nuclei, a fixed bed catalyst supporting platinum and/or rhodium is packed into a reactor, and hydrogen gas and molten petroleum resin are flowed upward from the bottom of the reactor in parallel flow. A method for producing hydrogenated petroleum resin, characterized by flowing the resin into a tank and continuously adding hydrogen to the resin.