JPS58194834A - Purification of cyclohexanone - Google Patents

Abstract

PURPOSE:To obtain the titled compound useful as a constitutional component for ink for ink jetting recording, not producing adipic acid, etc., by adding an antioxidant to cyclohexanone, subjecting it to distillation under reduced pressure in an inert gas atmosphere so that cyclohexanone is purified. CONSTITUTION:An antioxidant is added to cyclohexanone on the market, and the mixture is distilled in an inert gas atmosphere such as N2 under reduced pressure, preferably <=100mm.Hg, so that cyclohexanone is purified, to give cyclohexanone having <=10mug/ml active oxygen content, slightly producing an acidic substance such as adipic acid, etc. A phenolic compound and an amine-based compound are used as the antioxidant. 2,4,6-Tri-tert-butylphenol, etc. is used as the phenolic compound. and phenyl-alpha-naphthylamine, etc. as the amino-based compound. The amount of the antioxidant is preferably 0.05wt% based on cyclohexanone.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field of the Invention) The present invention relates to a method for purifying cyclohexanone. More specifically, the present invention relates to a method for obtaining cyclohexanone which does not generate any acidic substances such as adipic acid even when exposed to the action of oxygen.

TECHNICAL BACKGROUND OF THE INVENTION Commercially available cyclohexanone, often used as a high-boiling solvent, is oxidized by contact with air and n-
There is a tendency to produce rerianic acid, adipic acid, n-caproic acid, etc. In this way, cyclohexanone that has come to contain all acidic substances such as adipic acid may not interfere with its original purpose of use. For example, when commercially available cyclohexanone is used as a component of an ink for inkjet recording, the cyclohexanone is oxidized during storage or use of the ink and forms acidic substances such as adipic acid. The substance reacts with the inorganic salt blended as a conductive substance in the ink to form adipate, etc.
Since this adipate salt is insoluble, it precipitates. The precipitated adipates and other sediments obstruct the smooth flow of ink in the ink circulation system, resulting in deterioration of print quality.

(Prior Art) As described above, the emergence of cyclohexanone that does not easily generate acidic substances such as adipic acid has been long awaited, but a method for obtaining such cyclohexanone has not yet been disclosed.

(Purpose of the Invention) Based on the above-mentioned current situation, the inventors conducted research with the aim of developing a method for obtaining cyclo-xanone that is difficult to produce acidic substances such as adipine acid.

We have arrived at the present invention.

(Structure of the Invention) As a result of intensive research, the present inventors found that cyclohexanone with an active oxygen content t of 107+ f/ /me or less tends to produce acidic substances such as adipine acid even when it comes into contact with oxygen. In particular, we have found that cyclohexanone is suitable for forming an inkjet recording inkjet printer, and in this way, cyclohexanone is added as an antioxidant to commercially available cyclohexanone, and this mixture is completely inert gas atmosphere. I learned everything that can be obtained by distilling it under reduced pressure.

Therefore, in the present invention, an antioxidant is added to commercially available cyclohexanone, and the mixture is distilled under reduced pressure in a total inert gas atmosphere, thereby reducing the active oxygen content to 101r? /
Cyclohexanone'fr which is below me: This is a method for obtaining.

The configuration of the present invention and related matters will be explained in detail below.

(Active Oxygen) The active oxygen content in cyclohexanone in the present invention is a numerical value calculated according to the measuring method and calculation formula below.

In 35me of acetic acid-chloroform (2-1-1) previously placed in a 50me capacity Erlenmeyer flask,
Trial*E+ (cyclohexanone) 2m7! Add f, then [
After adding 2 mek of 50% potassium iodide aqueous solution, replace the gas phase of the flask with total nitrogen gas, and seal the flask for 30 minutes.
Leave it in the room for a minute. After leaving to stand, transfer all the liquid to a 100 mA beaker and add 30 ml of methanol.

The amount of iodine liberated is determined by titration with N/100 sodium thiobakeate. The amount of active oxygen contained in 2 ml of cyclohexanone is calculated using the following formula.

Active oxygen content (li) - 80xfx (A, -B) The letters in the above formula have the following meanings.

f: Titer of N/100 sodium thiosulfate solution A: 7 N/1.00 sodium thiosulfate solution (1ne) I required for titration
]: N/100 sodium thiosulfate solution (inert gas) required for the blank titration. Gas can be used, or nitrogen is preferred for industrial use.

(Antioxidant) Antioxidant VcU that can be used in the present invention
There are phenolic compounds and amine compounds.

As a phenolic compound, 2,6-tert-butyl-4-methylphenol, 2,4.6-)'J-1
Alkylphenols such as crt-funarphenol and styrenated phenol, 2,2'-methylene-bis-
(4-methyl-5-jerl-butylphenol),
Hisphenol A, 4,4'-butylidene-bis(6
-tert-butyl-3-methyl)phenol, 1
, 1-bis-(4-hydroxyphenyl)cyclohexane and other monoalkylenedialkylphenols 121
6-bis-(2'-hydroxy-3'-tcrt -
dialkylenetrialkylphenols with butyl-5'-methylbenzyl)-4-methylphenol, 2゜2'-thiobis-(4-methyl-5-1eri-butylphenol), 4,4'-thiobis-(3 -Methyl-6-tert-butylphenol), all bisphenol monosulfur ISs can be mentioned.

Amine compounds include phenyl-α-cyamine, phenyl-β-naphthylamine, and N.

N'-diphenyl-1)-phenylenediamine N.

N/,)-β-naphthyl-p-phenylenecyamine, N-cyclohexyl-N/-phenyl-p-phenylenediamine, p-hyFroxydiphenylamine, p-
Hydroxyphenyl-β-naphthylamine, 2,2.4
-1-rifthyl-1,2-dihydroquinoline.

These antioxidants can be used alone or in combination, but it is preferable to add at least 0.05% by weight to cyclohexanone, preferably 0.5% by weight.
If the above amount is added, the effect becomes saturated, so there is no need to add a large amount of VC.

(Distillation conditions) Since the boiling point of cyclohexanone is 155.6°C, it is desirable to distill K under reduced pressure, and 1
Distillation can be carried out at temperatures below 00℃ [100ml + II
It is preferable to reduce the pressure to about f/ or less.

(Examples and Comparative Examples) In order to make the present invention easier to understand, examples of the present invention and comparative examples for comparison are described below, but the present invention is not limited to the following examples. .

Example 1 Commercially available cyclohexanone (manufactured by Toagosei Kagaku Kogyo Co., Ltd.) 15.5 and 2 of an antioxidant were added to a 201 distillation flask.
, 4, 6- Pour all 232 liters of crt-butylphenol, introduce all nitrogen gas, replace all the air in the flask with nitrogen gas,] 5rrunfT? It was distilled under reduced pressure using VC.

As a result, the total active oxygen content of cyclohexanone was 26μ
? /me to 3μ'/ml.

Example 2 The same cyclohexanone as in Example 1] 7 to 7 to 2°4,
6-1-terl-butylphenol 2o9 was added and the mixture was vacuum distilled according to Example 1.

The distillation conditions and active oxygen content are shown in the row of experiment number 1 in Table 1 below. 4 μf/rnl for active oxygen content
It decreased with the sword.

Comparative Example 1 The commercially available cyclohexanone used in Example 1 and Example 2 was determined to have an active oxygen content of 1lllll without being completely distilled. The results are shown in the row of experiment number 2 in Table 1. Active oxygen content is 26 it
ivy in fl/ml.

Comparative Example 2 The same cyclohexanone used in Example I was treated with 15 mA [■
The fractions distilled out at VC of 90°C under v were collected. The active oxygen content of this fraction is 17 It? It was 7-/ml.

Comparative Example 3 The same cyclohexanone used in Example 2 was subjected to the same mvc treatment as in Example 2 except that no antioxidant was added, and the active oxygen content of the distilled cyclohexanone was measured. 1 as shown in the row of experiment number 4 of
5μ! //ml'T: Yes.

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X - (Reference Example) The performance of an inkjet recording ink constructed using purified cyclohexanone obtained by the present invention and an inkjet recording ink constructed using commercially available cyclohexanone was compared.

The materials used in the reference example are as follows.

(1) Solvent cyclohexanone, manufactured by Toagosei Chemical Co., Ltd. Ethanol manufactured by Imazu Pharmaceutical ■ (2) Binder Smilite Resin I'R, -51369Ii'' manufactured by Sumitomo Jurez ■ (3) Conductive agent thiocyanate triuno, Junsei Chemical ■ Lithium nitrate manufactured by Kanto Chemical ■ (4) Dyed Sashi Oil Blank 1113 B manufactured by Orient Chemical Industry ■ (5) Surfactant Shin-Etsu Silicone K p -340 manufactured by Shin-Etsu Chemical ■ The above materials are blended according to the composition shown in Table 2 After dissolving the mixture, it was filtered through a Fluorobor filter (pore size: 2 μI01, manufactured by Sumitomo Electric Corporation) to prepare four types of inkjet recording inks.The amounts shown in the table are parts by weight.

In the table, all untreated cyclohexanone was used in Reference Example J and Reference Example 3, and in Reference Example 2 and Reference Example 4, an antioxidant was added and cyclohexanone was distilled under reduced pressure in a nitrogen atmosphere.

Table 2 13 - The inkjet recording ink of Reference Example 2 was injected into Hitachi 1. ]
Applicable to printer (P-610 type).

A long-term stability test was conducted, but the circulatory system was often compromised, and very good results were obtained in terms of printing quality.

Similar tests were conducted on the inkjet recording ink of Reference Example 4, and all the same results were obtained.

(Effect of the invention) In the above examples and comparative examples,! As can be understood, according to the N production method of the present invention, the active oxygen content in cyclohexanone can be lowered to IO11977 or less. For example, it is possible to produce an inkjet recording ink that maintains its stability for a long period of time.

Applicant: Tokyo Ohka Kogyo Co., Ltd. Agent
Patent Attorney Minoru Isaka 14-

Claims (1)

[Claims] 1. A method for purifying cyclohexanone, which comprises adding an antioxidant to cyclohexanone and distilling the mixture under reduced pressure in an entirely inert gas atmosphere.