JPS5967238A - Method for purifying glutaraldehyde - Google Patents

Abstract

PURPOSE:To obtain a colorless and transparent glutaraldehyde solution of high quality useful as a high class tanning agent and capsule crosslinking agent, etc., by evaporating a crude glutaraldehyde solution in the presence of water continuously under reduced pressure to separate colored substances. CONSTITUTION:A crude glutaraldehyde solution obtained by hydrolyzing a 2- alkoxy-3,4-dihydro-2H-pyrane, etc., preferably an aqueous solution, is continuously evaporated at 100-200 deg.C, preferably 130-180 deg.C, under 5-500 Torr, preferably 10-100 Torr, reduced pressure at 90-99wt%, preferably 95-97wt%, evaporation rate to separate colored substances and give the aimed colorless and transparent glutaraldehyde solution of high quality containing <=70wt%, preferably <=60wt%, glutaraldehyde content stably without causing the deterioration of the individual glutaraldehyde.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for purifying glutaraldehyde.

Conventionally, glutaraldehyde is 2-alkoxy-3,4- obtained from acrolein and alkyl vinyl ether.
1,2 obtained by hydrolysis of dihydro-2H-pyrans, hydrogen peroxide oxidation of cyclopentene or 1,2-epoxycyclopentane, and peracetic acid oxidation of cyclopentene
- Manufactured by an oxygen or air oxidation method using a cobalt compound of cyclopencune diol as a catalyst.

Glutaraldehyde produced by these methods is used as a substitute for formaldehyde in leather and disinfectant disinfectants, etc. Glutaraldehyde produced by either method is usually commercially available as an aqueous solution containing glutaraldehyde at a concentration of 50% by weight or less. There is.

Recently, the demand for high-grade glutaraldehyde has increased as the demand for high-grade leather agents, capsule cross-linking agents, disinfectants for medical and agricultural chemicals, etc. has increased. However, regardless of the method used for producing glutaraldehyde, including the above-mentioned production method, the glutaraldehyde solution obtained inevitably contains impurities that cause coloration to varying degrees. However, to produce a colorless and transparent high-grade glutaraldehyde solution,
To date, no knowledge regarding the purification of so-called crude glutaraldehyde solutions has been reported.

By the way, when the distillation method applied to the purification of many compounds is adopted as a method for purifying a colored Japanese glutaraldehyde solution, it goes without saying that trace amounts of colored substances, which are non-volatile components, are separated; Due to the difference in vapor pressure between water and glutaraldehyde, the two are separated and distilled out.

However, since glutaraldehyde solutions are usually commercially available and used as aqueous solutions with a concentration of less than 50 parts of glutaraldehyde (mostly water), the method of separating glutaraldehyde and water is inefficient and meaningless. It is. Furthermore, in the distillation process, water, which is a low-boiling point component, is distilled out first, resulting in a high concentration of glutaraldehyde.
As the water content decreases and the high temperature continues for a long time, the glutaraldehyde itself deteriorates. Therefore, when using distillation as a purification method, a considerable portion of the glutaraldehyde in the crude glutaraldehyde solution is lost, resulting in a significant decrease in the glutaraldehyde yield. As far as refining is concerned, it must be said that it is an uneconomical method.

The present invention is characterized in that a colored substance is separated by continuously evaporating a crude glutaraldehyde solution under reduced pressure in the presence of water to stably obtain a colorless and transparent high-grade glutaraldehyde solution. This is a purification method.

The crude glutaraldehyde solution purified by the method of the present invention can be obtained by the hydrolysis method of 2-alkoxy-3°3-4-dihydro-2H-pyranes, cyclopentene or cyclopentene. v is 1, obtained by the hydrogen peroxide method of 1.2-epoxycyclopentene and peracetic acid oxidation of cyclopentene,
It may be produced by any method including oxygen extraction or air oxidation of 2-cyclopencundiol. -For example, J, angley, R,1,;
Emerson, W.C.; J.A.M., Che.
m,Soc,.

72(7), 3079-308] (1950), glutaraldehyde is produced by hydrolysis of 2-alkoxy-3,4-dihydro-21-T-pyrans obtained from acrolein and alkyl vinyl ether. It is produced by a reaction, and its aqueous solution has a yellowish brown color. Furthermore, alcohols produced as by-products during the hydrolysis reaction can be removed by distillation according to a conventional method, and the resulting solution can be used as a crude glutaraldehyde solution to be supplied to the evaporator.

As described above, according to the present invention, the crude glutaraldehyde solution is continuously evaporated under reduced pressure in the presence of water to separate the colored substance, which is a non-volatile component, to produce colorless and transparent high-grade glutaraldehyde. However, in terms of the stability of glutaraldehyde, the evaporation method requires that the crude glutaraldehyde solution be kept at a high temperature for a long time during evaporation and condensation of the Japanese glutaraldehyde solution. It is difficult to produce a colorless, transparent, and high-quality glutaraldehyde solution in coexistence with water at a certain ratio without maintaining the purified glutaraldehyde solution.

Furthermore, since glutaraldehyde solutions are usually commercially available and used as aqueous solutions with a glutaraldehyde content of 50% by weight or less, when purifying a crude glutaraldehyde solution, evaporated glutaraldehyde and water are condensed and mixed to form a purified glutaraldehyde solution. It is difficult to manufacture.

Therefore, the evaporation operation of the crude glutaraldehyde solution is performed at a pressure of 5 to 500 Torr, preferably 10 to 100'p.
under reduced pressure of orr, 100-200°C, preferably 130°C
At a heating temperature of ~180 °C, the supplied crude glutaraldehyde solution is heated to 90 °C within 1 minute, preferably within 30 seconds.
~99 weight ratio, preferably 95 to 97 weight ratio, the glutaraldehyde content in the resulting glutaraldehyde solution is 70 weight ratio or less, preferably 60 weight ratio or less, and the yield of glutaraldehyde is 95. A person in charge or above is attacked. The equipment used for such evaporation operations includes the time required to evaporate Japanese glutaraldehyde solution,
That is, the residence time of the supplied crude glutaraldehyde solution in the evaporator is shorter and the overall heat transfer coefficient is larger, and under the above operating conditions, the crude glutaraldehyde solution is continuously supplied and the evaporates and residues are continuously supplied. Evaporators with attached equipment that allow for targeted or intermittent extraction are preferred.

Among these types of evaporation equipment, a thin film evaporator, which is a type of stirred film type, is most suitable, but it is applicable if it satisfies the purpose of producing a colorless, transparent, high-quality glutaraldehyde solution of the present invention. The evaporator is not limited to any type.

Next, the method of the present invention will be explained in detail with reference to the drawings. Vacuum pump 14 and pressure regulating valve 1 as shown in the drawings
Crude glutaraldehyde is supplied to the stirred membrane type thin film evaporator 3 which is heated to a predetermined temperature by supplying saturated steam through the saturated steam supply port 4 and the drain discharge port 5 while maintaining the system internal pressure under a constant reduced pressure. A solution is continuously supplied from a supply port 1 via a metering pump 2. The gas evaporated in the stirred film type thin film evaporator 3 passes through a conduit 6, is condensed in a first condenser 7 through which cooling water at 30° C. is passed, and is recovered in a first receiver. Further, uncondensed gas passes through conduit 9 and is condensed in a second condenser through which cooling water at 10° C. is passed, and is recovered in a second receiver.

(The liquid containing the colored substance that has been completely evaporated in the stirred film type thin film evaporator 3 is extracted from the lower part as a residue into the residue receiver 12.In actual equipment, the first and second receivers 8 ,1
1, it is desirable to extract the condensed liquid from a single receiver continuously or intermittently to the outside of the system.

Next, the method of the present invention will be explained in more detail with reference to Examples.

Example I J, Am, Chem Soc, 72 (7)
, 3079-3081 (1950), by an acid-catalyzed hydrolysis reaction of 2-alkoxy/-3,4-dihydro-2H-pyrans obtained from acrolein and alkyl vinyl ether. A yellow-brown glutaraldehyde solution containing by-product alcohols was produced. In order to remove by-product alcohols from this solution, the alcohols were recovered by distillation.

The appearance of the obtained crude glutaraldehyde bath liquid was brownish-brown, and its color number was 500 to 600 based on A and PHA standards, and the glutaraldehyde content was 587, and most of the rest was water.

5.25 of the said crude glutaraldehyde solution under a pressure of 3 Q Torr in a stirred membrane type thin film evaporator 3 with a heat transfer area o, kg is continuously supplied at a constant flow rate for 30 minutes using the metering pump 2 to evaporate it, and the evaporated gas is cooled and condensed in two condensers 7゜10, and then transferred as evaporated matter to the lower two receivers 8. ，
It was collected on 11th. Non-volatile substances and colored substances containing a small amount of glutaraldehyde are transferred to a stirred film type thin film evaporator 3.
The residue was collected from the lower part of the tank into the residue receiver 14. At this time, the crude glutaraldehyde solution gradually evaporates and descends while forming an extremely thin film along the wall surface of the heat transfer portion of the stirred membrane type thin film evaporator. The time it took to finally reach the outlet at the bottom, that is, the average residence time, was extremely short, only about 30 seconds.

Immediately after the end of the experiment, the condensate as evaporated matter collected in the two receivers 8 and 11 and the residue collected in the residue receiver 12 were taken out and the weight, glutaraldehyde content, appearance, and large amount of water were taken out. When diluted and examined for properties such as solubility in water, the results shown in Table 1 were obtained.

(Hereinafter referred to as Hakuhaku) Table 1 Example 2 A portion of the evaporated material obtained in the two receivers 8゜11 obtained in the evaporation experiment of Example 1 was immediately taken out and mixed in a proportion according to the weight of the two obtained. Appropriately dilute the sweat solution, the liquid in each receiver alone, and the evaporated matter in the first receiver 8 with distilled water, transfer the sweat solution to a glass beaker, seal it, and conduct a test to confirm the stability of glutaraldehyde. t) Liquid. Each sample solution was stored in a dark place at room temperature and taken out at regular intervals to check its appearance, the occurrence of turbidity when the sample solution was diluted with 10 times the volume of water, the formation of water-insoluble compounds, etc. Changes in properties were observed. Since glutaraldehyde is soluble in water without limit, the generation of water-insoluble compounds indicates deterioration of glutaraldehyde and serves as a guideline for determining its stability. The results are shown in Table 2.

Table 2 Example 3 A similar test was conducted on each of the same sample solutions as in Example 2 under the same conditions except that the temperature was 50°C.
The results in the table were obtained.

Table 3 Example 4 The same crude glutaraldehyde solution used in Example 1 was prepared by adding 4.70 to 9 to 90 minutes under a pressure of 100'J''orr for 90 minutes.゜11
A more colorless and transparent glutaraldehyde solution was obtained. The results are shown in Table 4.

Table 4 Example 5 Regarding the evaporates from the two receivers 8 and 11 obtained in Example 4, several sample solutions were prepared in the same manner as Examples 2 and 3 in order to confirm the stability of glutaraldehyde. The test was conducted under the same conditions.

The results are shown in Table 5.

Table 5

[Brief explanation of the drawing]

The drawing is a flow sheet showing an example of the method for purifying glutaraldehyde according to the present invention. 1. Crude glutaraldehyde solution supply port, 2. Metering pump, 3. Stirring membrane thin film evaporator, 4. Saturated steam supply port, 5. Drain outlet, 6. Conduit, 7. 1 Condenser, 8. First receiver, 9 Conduit, 10. Second condenser, 11. Second receiver, 2. Residue receiver, 13. Pressure adjustment valve, 14. Vacuum pump. . Patent applicant: Nippon Distilling Industry Co., Ltd. 15- 16- Handmade Sales City 11 Yoi 14 December 16, 1981 Commissioner of the Patent Office Name: Kazu Sugi, Daidono 1, Matter f! [Display of Showa 5 [Komar! U application No. 177.51 April 2, Title of invention: Process for producing glutaraldehyde 3, Relationship with the case of the person making the amendment Patent applicant address: 1st name, 9 Takayashinmachi, Yamayo City, Chiba Prefecture
Representative Ministry of Kuchimoto Distilling T-Ju Co., Ltd. Takio Nunobu 1, Agent Address: Chiyo, Tokyo [11-ku, Niban-cho, 11th Ward] 5, Dia Palace Niban-cho, 9, Amendment Order 1/1 Voluntary Amendment 6, Amendment The opposite image of +fXIZti, -■,. 7. For details of the amendments, 7) 2.'a-3 amendments. (1) Page 4, line 8, “Zuru to distillation”, [to distillation, corrected to J, Ru1, 1 (2> 5th line, 7th line [1-angley, R, r,;
r+narson, W, C,: -l, ``l-ongleV, R, I, +
(3) Page 8, No. 711 [Corrected 1st receiver 1 as 1st receiver 8-1. (4) Page 8 Line 9, "Second condenser", [Second condenser 10.1] [a (5) Page 8, No. 'IO<'1 [Second receiver 1, "Second receiver 11”, corrected. (6) On page 10, line 1, "Residue receiver 14" was corrected to "Residue receiver 12." (7) Insert [-1] in the bottom row of the rightmost column of Table 1 on page 11. (8) Correct the 3rd and 4th lines of the rightmost column of Table 2 on page 12 as indicated. "2 hours 4 hours"

Claims (6)

[Claims] (1) separating the colored substances by continuously evaporating the crude glutaraldehyde solution under reduced pressure in the presence of water;
A method for purifying glutaraldehyde, characterized by stably obtaining a colorless and transparent high-grade glutaraldehyde solution. (2) Evaporation is performed at a heating temperature of 100-200℃ and a temperature of 5-5℃.
A method according to claim 1, which is carried out under a pressure of 00']'orr. (3) Evaporation is performed at a heating temperature of 130 to 180°C and
A method according to claim 1, which is carried out under a pressure of 1.00 Torr. (4) The method according to any one of claims 1 to 3, wherein the crude glutaraldehyde solution is an aqueous solution. (5) The evaporation rate of purified glutaraldehyde solution is 90-9
9. The method according to any one of claims 1 to 4, wherein the weight ratio is 9. (6) The method according to any one of claims 1 to 5, wherein the glutaraldehyde content in the purified glutaraldehyde solution is 70% by weight or less.