JPH044020B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a Raney nickel catalyst material, and more particularly to an unactivated catalyst material comprising a Raney alloy of nickel and aluminum. Raney nickel is well known as a catalyst with hydrogenation ability. This catalyst has excellent activity in a nickel catalyst, allows the reaction to proceed even below room temperature, and is also characterized by being very inexpensive, and is widely used in industry. This catalyst is prepared in a completely different manner than other nickel catalysts. That is, it is a porous nickel catalyst prepared by treating a nickel-aluminum alloy with an alkaline aqueous solution to elute aluminum, so-called expansion, and then washing with water. Washing with water is usually performed by the decanting method. The nickel-aluminum alloys used to prepare such Raney nickels are typically powders.
Since this unactivated catalyst material is intended to increase its activity by increasing its surface area, its particle size is small. Therefore, when washed with water using the decanting method, the sedimentation property is poor and it is difficult to elute aluminum appropriately. In addition, the variation in particle size of the alloy powder makes it easy to cause secondary agglomeration, making it difficult to elute aluminum uniformly. The hydrogen adsorbed on top is removed, resulting in a decrease in activity. The present inventors found that this problem was caused by the fact that the unactivated catalyst material was in powder form, and as a result of further investigation, they found that if the unactivated catalyst material was formed from short fibers of a specific thickness. The present invention was achieved based on the discovery that not only the cleaning performance is improved, but also the catalytic effect is unexpectedly increased. That is, the present invention provides a Raney-nickel catalyst material consisting of nickel-aluminum alloy short fibers having a thickness in the range of 2 to 25 μm, of which at least 35% have a thickness of 2 to 10 μm, and having a uniform length. It is. This specific short fiber is a novel short fiber that has not been previously known. These short fibers increase the rotational speed of the metal material, which is the workpiece, and reduce the feed rate of the cutting tool to feed it evenly, while at the same time reducing the amount of chips obtained during turning while causing the cutting tool to vibrate ultrasonically in the direction of the cutting tool shank. Obtained by collecting. The short metal fibers of the present invention cannot be obtained by conventional chatter vibration cutting. In other words, because the cutting edge is vibrated by the vibration energy given by a separately installed ultrasonic oscillator, the cutting edge does not slide on the workpiece surface and bites into the workpiece even if the cutting and feed rates are reduced. It is possible to produce fine fibers with less variation. In the present invention, it is important that the short fibers not only have the necessary fineness to increase surface area, but also be relatively uniform. If the short fibers are not relatively uniform, the elution of aluminum will not proceed uniformly during expansion.
Further, even if the thickness of the short fibers is relatively uniform, short fibers exceeding a predetermined thickness will not form the surface area necessary for imparting activity. What is important here is that the dissolution of aluminum during development is also affected by the variation in the length of the short fibers. For this reason, short fibers must have a relatively uniform length. As a result, the unactivated catalyst material of the present invention has a thickness in the range of 2 to 25 μm, of which at least 35% has a thickness of 2 to 10 μm, and must be short fibers of uniform length. . As far as is known, conventional powdered catalyst materials on the market have particle sizes distributed over a wide range and vary as shown in the comparative examples described below, and are significantly different from the short fiber catalyst material of the present invention. . Due to their length, such catalyst materials of the present invention have superior settling properties compared to powders, and their increased randomization tendency avoids close packing and prevents secondary agglomeration, which in turn improves cleaning properties. To,
Increases the catalytic effect, ie the effect of activity and reaction selectivity. The catalytic effect obtained with the catalyst material of the present invention is not theoretically certain, but it is important that the catalyst material has a uniform thickness and length, so that the aluminum elution reaction proceeds uniformly. This is thought to be due to the uniformity of the depth of the pores that form the porosity of Raney nickel. Another advantage of the catalyst material of the present invention is that since it is a short fiber, it is easy to separate and recover the catalyst when the reaction is completed in the liquid phase. The length of the short fibers of the present invention is determined according to the liquid phase reaction or gas phase reaction, that is, it may be short for liquid phase reaction and long for gas phase reaction, but it is suitably within the range of 0.01 to 10 mm. It is. The workpiece made of a nickel-aluminum alloy used in producing the catalyst material of the present invention has a nickel content of 20 to 40%, preferably 20 to 35%.
% nickel and aluminum alloy. If the nickel content is less than 20%, only a catalyst with poor activity will be obtained, and if it exceeds 40%, cutting will become difficult and cuttings of a predetermined thickness and length cannot be obtained. The present invention will be explained in further detail. Example 1 High purity nickel 27% and high purity aluminum 73%
After melting at approximately 1500℃ in an inert gas atmosphere using a high frequency furnace and stirring thoroughly, the molten metal is poured into a cylindrical mold heated to 200-300℃ and left to cool at room temperature. A cast product (diameter 60mm, length 60mm) was made using Next, install this cast product on the lathe, and calculate the rotation speed of the cast product: 1500r.pm, bite piece amplitude: 15μm, bite vibration frequency: 21.6KHz, bite feed amount: 0.2μm/rev (constant speed), where μm is the feed amount, and rev is 1. Rotation is shown respectively. The molded product was cut in the direction of the cylindrical end surface with a cutting tool that applied feed and ultrasonic vibration in the direction of the cutting tool shank under the following cutting conditions to obtain nickel-aluminum alloy short fibers with a nickel content of 27%. The obtained short fibers have a thickness in the range of 2 to 24 μm, of which 2 to 10 μm
67% (number) of the pieces had a thickness of , the variation in length was 0.1 to 0.6 mm, and the distribution of the thickness was as follows. For comparison, the particle size distribution of commercially available alloy powder for Raney nickel (nickel content 50%) is also shown.

[Table] Example 2 High purity nickel 30% and high purity aluminum 70%
Nickel-aluminum alloy short fibers with a nickel content of 30% were obtained in the same manner as in Example 1, except that the molded product was cut at a rotating speed of 700 r.pm and a bit feed rate of 0.64 μm/rev (constant speed). Ta. The obtained short fibers have a thickness in the range of 3 to 25 μm, of which 3
38% (number) are ~10μm thick,
The length variation was 0.1 to 0.6 mm, and the thickness distribution was as follows. 3 to 10 μm 38 number% (15.2% by weight) 10 to 20 μm 51 (53.4) 20 to 25 μm 11 (31.5) Next, in catalyst preparation examples A, B, and C, Examples 1 and 2, and An example of manufacturing a catalyst using a catalyst material of a comparative example is shown. Catalyst Preparation Example A 40 parts by weight of the short fibers of Example 1 were added to 20 parts by weight in a conventional manner.
% caustic soda aqueous solution 300 parts by weight little by little,
Stir for about 60 minutes while maintaining the temperature at 50 to 60°C, then stop stirring and let the short fibers precipitate and pour out the aqueous solution.
The precipitate was washed with water by decanting and finally washed three times with 95% ethanol. The number of times of water washing was 4 times, and the supernatant liquid showed almost neutrality. Catalyst Preparation Example B When developed in the same manner as Catalyst Preparation Example A except that 40 parts by weight of the short fibers of Example 2 were added little by little to 290 parts by weight of a 20% caustic soda aqueous solution, the same results as in Catalyst Preparation Example A were obtained. Ta. Catalyst Preparation Example C When 40 parts by weight of the alloy powder of Comparative Example was developed in the same manner as in Catalyst Preparation Example A, the supernatant liquid showed neutrality after washing with water 5 times. Next, in Hydrogenation Examples A1, B1, and C1, the results obtained by hydrogenating acetone using the catalysts of Catalyst Preparation Examples A, B, and C, respectively, will be compared. In both tests, 4 g of each catalyst was mixed with 27 g of acetone (37
ml) and 100 ml of ion-exchanged water were added, hydrogenation reaction was carried out at room temperature and pressure for 1 hour, and the yield of isopropanol was first measured.Furthermore, in order to check the sustainability of activity, separation and collection was repeated 4 times and the same procedure was carried out. The hydrogenation reaction was carried out for 1 hour at a time, and the yield of each reaction was measured. The results are as follows.

[Table] In this way, short fibers were found to have increased initial activity and activity persistence compared to powder. Next, in hydrogenation examples A2 and C2, each catalyst preparation example A
Compare the results obtained in the catalytic hydrogenation of 1-heptyne using the catalysts C and C. Hydrogenation example A2 Add 3g of short fiber catalyst to 100c.c. of absolute ethanol,
19.2 g of 1-heptyne was added and hydrogenated at an initial pressure of 4 atm and room temperature. After absorbing 1 mole of hydrogen in about 5 minutes, the reaction was stopped, and the reaction solution was taken out.
When the catalyst was separated, the filtrate was poured into water to remove ethanol, dried, and analyzed by gas chromatography, heptene-1 was obtained in a yield of 81%.
By-products (heptane, heptene-1 isomers, polymers, etc.) were 18%. Hydrogenation example C2 Hydrogenation example except that a powder catalyst is used and the reaction is stopped after absorbing 1 mole of hydrogen in about 6 minutes.
Catalytic hydrogenation of 1-heptyne in the same manner as A2,
Analysis showed that the yield of heptene-1 was 72%, and by-products (heptane, isomer of heptene-1,
Polymers, etc.) accounted for 26%. In this way, short fibers were found to have increased reaction selectivity compared to powder. Next, in hydrogenation examples A3 and C3, each catalyst preparation example A
Compare the results obtained in the catalytic hydrogenation of benzyl cyanide using the catalysts C and C. Hydrogenation example A3 100g of benzyl cyanide in autocrème,
After adding 1 g of short fiber catalyst and sealing it, 15 ml of liquid ammonia was added, and then hydrogen was introduced to 80 atm.
The hydrogenation reaction was carried out at a temperature of 100 to 110°C with sufficient shaking. Hydrogen absorption stopped in about 65 minutes and the reaction solution was finished. When the reaction solution was separated by vacuum distillation and each fraction was analyzed by gas chromatography, β-phenylethylamine was obtained in a yield of 94%.
The amount of by-product (di-(β-phenylethyl)amine) was 3%. Hydrogenation Example C3 A hydrogenation reaction of benzyl cyanide was carried out in the same manner as in Hydrogenation Example A3 using a powdered catalyst. After about 75 minutes, hydrogen absorption stopped and the reaction was completed. The yield of β-phenylethylamine was 86%, and the by-product (di-
(β-phenylethyl)amine) was 5%. As is clear from the above results, the unactivated catalyst material of the present invention exhibits excellent performance and is useful.

Claims (1)

[Claims] 1. A workpiece having a thickness in the range of 2 to 25 μm, which is obtained by vibration lathing by rotating the workpiece at high speed using a lathe and applying ultrasonic vibration in the direction of the bite shank. Raney nickel catalyst material consisting of nickel-aluminum alloy short fibers of uniform length, at least 35% of which are ~10 μm thick. 2. Claim 1, in which the length of the nickel-aluminum alloy short fibers is in the range of 0.01 to 10 mm.
Raney nickel catalyst material as described in Section.