A kind of isophorone nitrile composition with stable storage and preparation method thereof

Abstract

The present invention provides a kind of isophorone nitrile composition of stable storage, wherein containing metal element, based on the mass of isophorone nitrile in the composition, the total content of metal element is less than or equal to 2.0ppm, and the metal element includes alkali metal, alkaline earth metal, transition metal element. Also containing metal extractant, based on the mass of isophorone nitrile in the composition, the metal extractant content is 0.1-2.0ppm, and the metal extractant is selected from organic carboxylic acid compounds. The isophorone nitrile composition provided by the present invention has excellent storage stability, even if stored at high temperature for a long time, it is also possible to effectively prevent the reduction of purity and the growth of chromaticity, which is conducive to industrialized production.

Description

Technical Field

[0001] The invention belongs to the technical field of isophorone nitrile and relates to an isophorone nitrile composition capable of stable storage and a preparation method thereof. Background Art

[0002] Isophorone nitrile, chemical name 3-nitrile-3,5,5-trimethylcyclohexanone (IPN), is used in the industry to synthesize isophorone diamine. This compound can be used as a curing agent and crosslinking agent for epoxy resin coatings, and can also be further reacted with phosgene to synthesize isophorone diisocyanate. The synthesis process of isophorone nitrile is to heat hydrocyanic acid and isophorone in the presence of an alkaline catalyst, and the obtained reaction solution is neutralized, desolvated and distilled to obtain the product isophorone nitrile.

[0003] Most of the patents reported so far are based on improving the yield and purity of the reaction product isophorone nitrile, and improving it in many aspects. Some patents report different catalysts, inorganic base catalysts such as alkali metal, alkaline earth metal oxides, hydroxides CN1729162, US5091554, etc., cyanide US5142090, alkoxide US5254711, and alkali metal, alkaline earth metal carbonate JP4112862, etc.; another is an organic base catalyst such as quaternary ammonium base / salt US5516928, quaternary phosphonium base / salt US5179221, etc. Some patents report different reaction temperatures and pressures. In the patent publication US5254711, the reaction temperature is 130-180°C and the reaction pressure is normal pressure; in the patent publication CN1729162, the reaction temperature is 150-200°C and the reaction pressure is between 1-3 bar; in the patent publication US5011968, the reaction temperature is between 110-115°C and the reaction is carried out under normal pressure. Some patents report different reaction processes. Intermittent processes, such as the public patents US3270044A1, US4299775, and CN201010559261.9, are characterized by strong adaptability, simple equipment, high raw material conversion rate and yield, but at the same time, they require many supporting equipment, high energy consumption, large space occupation, and cumbersome operation. Public patents CN201610182680.2, CN201110083804.9, and CN20130145143.7 use multiple kettles, fixed beds, or reaction tubes to achieve continuous reactions, but there are also many problems, such as uneven material mixing, low mass and heat transfer efficiency, and many by-products. There are also patents reporting separation processes. The public patent CN201110083804.9 uses distillation-rectification to purify the product; the public patent CN201611071100.9 uses distillation-melt crystallization to purify the product.

[0004] It can be seen that the above measures are all innovative and modified around how to improve the reaction yield and product purity. As is known to all, the melting point of isophorone nitrile is 66-68°C. In order to facilitate its transportation or pipeline transportation, it is usually necessary to store or transport it at high temperature. However, during long-term high-temperature storage, it is found that isophorone nitrile is very easy to react with oxygen to form isophorone nitrile oxide, the structure of which is shown in Formula 1 below.

[0005]

[0006] Therefore, it is necessary to develop an isophorone nitrile that can be stably stored to solve the problems of increased oxides and rapid increase in chromaticity during storage that are not conducive to industrial production. Summary of the invention

[0007] The purpose of the present invention is to fill the gap in the prior art and provide a stably stored isophorone nitrile and a preparation method thereof, thereby increasing the storage period without changing the current storage conditions and ensuring the safety of such nitrile-containing materials.

[0008] In order to achieve the above purpose, the present invention adopts the following technical solution:

[0009] The inventors have found in research that the isophorone nitrile product contains metallic elements, which are important factors affecting the storage stability of isophorone nitrile, even if the residual trace metallic elements still significantly reduce its stability, but if the content of the metallic elements in the isophorone nitrile product is controlled to be reduced to a specific range, its storage stability can be significantly improved. In addition, the inventors have further found that if a specific type of metal extraction agent of a specific amount is introduced into the isophorone nitrile product, the stability performance of the isophorone nitrile composition product can be made more excellent. Even if the isophorone nitrile composition thus obtained is stored at high temperature for a long time, the reduction of purity and the growth of chromaticity can be effectively prevented.

[0010] The invention provides an isophorone nitrile composition which can be stably stored. The composition contains metal elements. Based on the mass of the isophorone nitrile in the composition, the total content of the metal elements is ≤2.0 ppm, preferably ≤1.0 ppm, and more preferably ≤0.8 ppm.

[0011] Preferably, the metal element includes any one of alkali metals, alkaline earth metals, and transition metal elements, or a combination of at least two of them; more preferably, the alkali metal element is sodium or potassium, the alkaline earth metal element is calcium, and the transition metal element is iron, nickel, chromium, or manganese.

[0012] Preferably, the isophorone nitrile product of the present invention is prepared by reaction with isophorone and hydrocyanic acid as raw materials; the method for preparing isophorone nitrile from isophorone and hydrocyanic acid is known to those skilled in the art, but the total content of metal elements in the isophorone nitrile product prepared thereby is usually above 5 ppm; according to the experimental verification results of the present invention, the lower the content of metal elements in the isophorone nitrile product, the better the storage stability. However, due to the existing isophorone nitrile products, on the one hand, in the preparation process using isophorone and hydrocyanic acid as raw materials, metal compound catalysts such as alkali metals or alkaline earth metals are usually involved, and on the other hand, in the industrial production process, it is inevitable to contact with metal equipment and devices such as stainless steel, which has problems such as metal element dissolution and entrainment, and it is difficult to completely remove the trace metal elements therein. The isophorone nitrile provided by the present invention can achieve the total content of metal elements controlled at ≤2.0 ppm, but usually there will be no less than 0.1 ppm of residue. The present invention can obtain an isophorone nitrile product with a total content of metal elements in the range of 0.1-2.0 ppm, so that it has excellent storage stability.

[0013] Furthermore, the storage-stable isophorone nitrile composition of the present invention further contains a metal extractant, and the content of the metal extractant is 0.1-2.0 ppm, preferably 0.3-1.0 ppm, based on the mass of isophorone nitrile in the composition.

[0014] Preferably, the metal extractant is selected from any one or a combination of at least two of organic carboxylic acid compounds, more preferably diethylenetriaminepentaacetic acid, triethylenetetraaminehexaacetic acid, and oxalic acid.

[0015] As an optional technical solution, in the isophoronenitrile composition for stable storage according to the present invention, the contents of metal ions and metal extractants may be the same or different.

[0016] The storage and transportation temperature of the stably stored isophoronenitrile composition of the present invention is higher than the melting point of isophoronenitrile (66.6-68.5° C.), preferably in the range of 75-90° C., and more preferably in the range of 80-85° C.

[0017] After the stably stored isophorone composition of the present invention is placed at the above temperature for 2 months, the increase value of the impurity content is ≤0.5%, preferably ≤0.3%, based on the mass of isophorone nitrile in the composition.

[0018] The storage-stable isophorone composition of the present invention has a chromaticity increase of ≤5 Hazen, preferably ≤3 Hazen, after being placed at the above temperature for 2 months.

[0019] The present invention also provides a method for preparing the stably stored isophorone nitrile composition, comprising the following steps:

[0020] 1) isophorone and hydrocyanic acid react under a basic catalyst and heating conditions to obtain an isophorone nitrile reaction solution;

[0021] 2) adding an acidic substance to the isophoronenitrile reaction solution of step 1) to carry out a neutralization reaction to obtain a neutralization reaction solution;

[0022] 3) adding a metal extractant to the neutralization reaction solution of step 2) for extraction, and then purifying to obtain the isophorone nitrile composition that is stable for storage.

[0023] In the preparation method of the present invention, the molar ratio of isophorone to hydrocyanic acid in step 1) is 1-3:1, preferably 1.5-2:1;

[0024] The amount of the alkaline catalyst added is 1000-20000ppm, preferably 3000-5000ppm, based on the mass of isophorone;

[0025] In the preparation method of the present invention, the alkaline catalyst in step 1) is selected from any one or a combination of at least two of sodium hydroxide, potassium hydroxide, sodium cyanide, lithium hydroxide, calcium hydroxide, sodium carbonate, potassium carbonate, sodium methoxide, sodium ethoxide, triethylamine, tetramethylammonium hydroxide, tetramethylammonium chloride and tetramethylammonium bromide, preferably any one or a combination of at least two of lithium hydroxide, sodium ethoxide and triethylamine.

[0026] In the preparation method of the present invention, the reaction temperature in step 1) is 100-180° C., preferably 120-160° C.;

[0027] The reaction can be a batch reaction, first adding isophorone into a reactor, heating to the reaction temperature, then adding an alkaline catalyst and hydrocyanic acid, the reaction time is 0.5-5h, preferably 1-2h, after the reaction is completed, proceeding to the next step; it can also be a continuous reaction, such as using a multi-tank continuous or tubular reaction, isophorone, hydrocyanic acid, and an alkaline catalyst are continuously introduced into the reactor in proportion at the reaction temperature, and the average residence time is 2-10h, preferably 3-5h.

[0028] In the preparation method of the present invention, the acidic substance in step 2) is selected from organic sulfonic acid compounds, preferably any one or a combination of at least two of methanesulfonic acid, ethanesulfonic acid, propanesulfonic acid, naphthalene monosulfonic acid, naphthalene disulfonic acid, naphthalene trisulfonic acid, dodecylbenzenesulfonic acid, benzenesulfonic acid and p-toluenesulfonic acid, more preferably benzenesulfonic acid and / or p-toluenesulfonic acid. Since the isophorone nitrile reaction solution obtained in step 1) is alkaline, isophorone nitrile is easily dissociated, and is relatively stable after neutralization in an acidic medium, at least one acidic substance is selected as a neutralizing agent in the present invention.

[0029] Preferably, the molar ratio of the acidic substance to the alkaline catalyst in step 1) is 1.0-2.0:1, preferably 1.1-1.5:1.

[0030] In the preparation method of the present invention, the neutralization reaction in step 2) is carried out at a temperature of 100-180° C., preferably 120-160° C., for a time of 0.2-2 h, preferably 0.5-1 h; and the pH of the reaction solution after neutralization is 5-8, preferably 6-7.

[0031] In the preparation method of the present invention, the metal extractant in step 3) is prepared as an aqueous solution with a concentration of 50-10000 ppm, preferably 1000-5000 ppm; the metal extractant is of the same type as that in the aforementioned isophorone nitrile composition, and is selected from any one or a combination of at least two of organic carboxylic acid compounds, more preferably diethylenetriaminepentaacetic acid, triethylenetetraaminehexaacetic acid, and oxalic acid.

[0032] Preferably, the mass ratio of the aqueous solution of the metal extractant to the neutralization reaction liquid is 1:5-20, preferably 1:10-15;

[0033] In the preparation method of the present invention, the extraction temperature of step 3) is 30-100°C, preferably 50-80°C, and extraction at this temperature can avoid the precipitation of IPN in the reaction solution; the average residence time of the extraction process is 5-120min, preferably 20-60min, and the residence time includes stirring and static stratification operations. The purpose of the metal extraction is to extract the metal ions introduced into the reaction solution by the raw materials isophorone, hydrocyanic acid, alkaline catalyst and acidic substances, as well as the metal ions dissolved by the device during the high-temperature reaction process. The extraction operation can be repeated multiple times, preferably 1-2 times, and the content of metal ions in the neutralized reaction solution is controlled by the metal extractant extraction operation to be 0.1-100ppm of the mass of the reaction solution, preferably 1-50ppm.

[0034] In the preparation method of the present invention, the purification method described in step 3) includes distillation concentration and rectification. According to the present invention, after the mixed solution after extraction is placed and stratified, the upper layer is a reaction solution containing isophorone nitrile, which enters the next distillation tower for refining, and the lower layer is an extraction phase containing metal elements, which enters another distillation tower. The light component of the extraction phase distillation is a lean brine containing trace metal extracts and isophorone. The lean brine can be recycled, that is, it is mixed with a metal extractant in proportion and reused as an extraction solution. The extraction phase is distilled and reorganized into a rich brine containing a large amount of metal extracts and acidic substances, and the rich brine is treated as wastewater. The reaction solution after extraction of the present invention needs to be distilled to recover isophorone, and then rectified to obtain the isophorone nitrile composition. The specific distillation and rectification process operations are well known in the art. Those skilled in the art can achieve the operation by any desired method, which will not be repeated here.

[0035] According to the preparation method of the isophorone nitrile composition of the present invention, the reaction liquid after extraction contains the metal element cations, and anions such as metal extractant ions, Cl - 、SO4 2- 、NO 3- , any one of basic catalyst anions and acidic substance anions or a combination of at least two thereof. In the isophorone nitrile composition obtained after distillation and rectification of the present invention, based on the mass of isophorone nitrile therein, the total content of metal elements is ≤2.0ppm, preferably ≤1.0ppm, more preferably ≤0.8ppm; the content of the metal extractant is 0.1-2.0ppm, preferably 0.3-1.0ppm; and the total content of other trace anions is less than 2.0ppm.

[0036] When the isophorone nitrile composition prepared by the method is stored for 2 months in a temperature range higher than the melting point of isophorone nitrile (such as 75-90° C.), the increase in impurity content detected by gas chromatography is ≤0.5%, and the increase in chromaticity is ≤5 Hazen, which can meet the needs of actual production.

[0037] In industrial production, the isophorone nitrile reaction liquid is generally distilled to remove light components, such as water, residual hydrocyanic acid and excess isophorone, to obtain a crude isophorone nitrile, and then the product is purified by high vacuum distillation. However, the present invention has found in actual operation that the metal elements introduced into the system by the catalyst and the metal material production device will still have a residual content of 5ppm or more after being treated by distillation, which has an extremely adverse effect on its storage stability. Reducing the content of metal elements as much as possible can significantly improve its storage stability.

[0038] It is worth noting that the isophorone nitrile composition undergoes an oxidation reaction during high-temperature storage to generate an oxidation product as shown in Formula 1. By controlling the content of metal elements, the generation of such impurities can be significantly suppressed.

[0039] Compared with the prior art, the technical solution provided by the present invention has the following beneficial effects:

[0040] By controlling the content of metal elements in the isophorone nitrile composition, the increase of impurities and the growth of chromaticity during high-temperature storage are effectively suppressed, and the stable storage period is extended; the introduction of a metal extraction process in the separation process can solve the problem of corrosion or blockage of equipment caused by metal elements or salts, and extend the production operation period. The synergistic effect of the trace amount of metal extractant remaining in the isophorone nitrile composition further improves the stable storage of the composition.

[0041] The isophorone nitrile composition of the present invention can be used to synthesize isophorone diamine, and the compound can be used as a curing agent, a crosslinking agent, etc. of epoxy resin coatings; or further synthesized into isophorone diisocyanate, which can be used for coatings and adhesives, etc. DETAILED DESCRIPTION

[0042] The present invention will be further described below in conjunction with the embodiments, but the present invention is not limited to the listed embodiments, and should also include any other known changes within the scope of the rights claimed by the present invention.

[0043] The main sources of raw materials used in the examples of the present invention are as follows. Other raw materials are common commercially available unless otherwise specified:

[0044] Isophorone, Wanhua Chemical, 99.8%;

[0045] Hydrocyanic acid, Wanhua Chemical, 99.0%;

[0046] Potassium hydroxide, Chinese medicine, 99.0%;

[0047] Sodium methoxide, Aladdin, 97.0%;

[0048] Sodium carbonate anhydrous, alfa, 99.9%.

[0049] The main analysis and testing methods used in the embodiments of the present invention are:

[0050] GC purity test instrument: Agilent, column: DB-5, FID detector, injection port temperature 260℃, detector temperature 300℃, carrier gas: nitrogen (10mL / min), split ratio 10:1, injection volume: 20ul. Column box initial temperature 100℃, maintained for 0.5 minutes, heated to 160℃ at 15℃ / min, maintained for 1.5 minutes, heated to 260℃ at 20℃ / min, maintained for 9 minutes.

[0051] Chroma testing instrument: HACH LICO 500 colorimeter.

[0052] Metal analysis instrument: Thermo Scientific ICAP 7200ICP-OES.

[0053] 1. Preparation of isophorone nitrile composition:

[0054] Example 1

[0055] The preparation of a storage-stable isophoronenitrile composition comprises the following steps:

[0056] 1) Add 414 g (3.0 mol) of isophorone to a 316L batch reactor, heat to 100°C, add 8.28 g (0.15 mol) of potassium hydroxide, pass 27 g (1.0 mol) of hydrocyanic acid liquid, maintain the temperature at 100°C for 5 h, and obtain an isophorone nitrile reaction solution.

[0057] 2) Add 21.3 g (0.22 mol) of methanesulfonic acid to the isophoronenitrile of step 1), neutralize at 100° C. for 2 h, and then cool to 30° C. to obtain a neutralized reaction solution with a pH of 5.0.

[0058] 3) Add 23.5g of 10000ppm oxalic acid aqueous solution to the neutralization reaction solution of step 2) for extraction (the mass ratio of aqueous solution to neutralization reaction solution is 1:20), stir at 30°C for 60min, keep warm and stand for 60min, separate the upper organic phase (i.e., the reaction solution containing isophorone nitrile), sample and test the metal ions in the organic phase, which are potassium, iron, sodium, nickel, chromium, manganese, etc., with a total content of 20ppm. The organic phase is first subjected to vacuum distillation to recover 268g of isophorone, and then vacuum distilled to obtain 150g of the product isophorone nitrile composition.

[0059] Gas chromatography test of the isophorone nitrile composition: the isophorone conversion rate was 32.3%, the isophorone nitrile selectivity was 99.0%, and the purity was 99.6%.

[0060] The isophorone nitrile composition product was tested. Based on the mass of isophorone nitrile therein, the metal ions were sodium, potassium, iron, nickel, chromium, and manganese, with a total content of 2.0 ppm, the oxalic acid content was 2.0 ppm, and the remaining anions were methanesulfonate with a content of 0.6 ppm. The total impurity content of the oxidation product shown in Formula 1 was 0.08%, and the chromaticity was 8.0 Hazen at 90°C.

[0061] Example 2

[0062] The preparation of a storage-stable isophoronenitrile composition comprises the following steps:

[0063] 1) Add 276 g (2.0 mol) of isophorone to a 316L batch reactor, heat to 160°C, add 2.8 g (0.05 mol) of sodium methoxide, pass 27 g (1.0 mol) of hydrocyanic acid liquid, maintain the temperature at 160°C for 0.5 h, and obtain an isophorone nitrile reaction solution.

[0064] 2) Add 8.1 g (0.05 mol) of benzenesulfonic acid to the isophoronenitrile of step 1), neutralize at 160° C. for 1 h, and then cool to 50° C. to obtain a neutralized reaction solution with a pH of 8.0.

[0065] 3) Add 31.4 g of 5000 ppm diethylenetriaminepentaacetic acid aqueous solution to the neutralization reaction solution of step 2) for extraction (the mass ratio of aqueous solution to neutralization reaction solution is 1:10), stir at 50°C for 5 min, keep warm and stand for 60 min, separate the upper organic phase (i.e., the reaction solution containing isophorone nitrile), sample and test the metal ions in the organic phase, which are sodium, potassium, iron, nickel, etc., with a total content of 12 ppm. The organic phase is first subjected to reduced pressure distillation to recover 130 g of isophorone, and then reduced pressure distillation is performed to obtain 152 g of the product isophorone nitrile composition.

[0066] Gas chromatography test of the isophorone nitrile composition: the isophorone conversion rate is 48.5%, the isophorone nitrile selectivity is 99.0%, and the purity is 99.5%.

[0067] The isophorone nitrile composition product was tested. Based on the mass of isophorone nitrile therein, the metal ions were sodium, potassium, iron, and nickel, with a total content of 0.8 ppm, the diethylenetriaminepentaacetic acid content was 0.3 ppm, and the remaining anion was benzenesulfonate with a content of 2.0 ppm. The total impurity content of the oxidation product shown in Formula 1 was 0.10%, and the chromaticity was 8.5 Hazen at 90°C.

[0068] Example 3

[0069] The preparation of a storage-stable isophoronenitrile composition comprises the following steps:

[0070] 1) Add 138 g (1.0 mol) of isophorone to a batch reactor made of 316L material, heat to 180°C, add 0.14 g (0.003 mol) of sodium carbonate, pass 27 g (1.0 mol) of hydrocyanic acid liquid, maintain the temperature at 180°C for 3 h, and obtain an isophorone nitrile reaction solution.

[0071] 2) Add 0.69 g (0.003 mol) of naphthalene monosulfonic acid to the isophoronenitrile of step 1), neutralize at 180° C. for 0.2 h, and then cool to 90° C. to obtain a neutralized reaction solution with a pH of 7.6.

[0072] 3) Add 33.2 g of 1000 ppm triethylenetetraaminehexaacetic acid aqueous solution to the neutralization reaction solution of step 2) for extraction (the mass ratio of aqueous solution to neutralization reaction solution is 1:5), stir at 90°C for 20 min, keep warm and stand for 60 min, separate the upper organic phase (i.e., the reaction solution containing isophorone nitrile), sample and test the metal ions in the organic phase, which are sodium, potassium, iron, etc., with a total content of 7 ppm. The organic phase is directly subjected to vacuum distillation to obtain 150 g of the product isophorone nitrile composition.

[0073] Gas chromatography test of the isophorone nitrile composition: the isophorone conversion rate is 97.0%, the isophorone nitrile selectivity is 99.0%, and the purity is 99.5%.

[0074] The isophorone nitrile composition product was tested. Based on the mass of isophorone nitrile therein, the metal ions were sodium, potassium, and iron, with a total content of 0.2 ppm, the triethylenetetraaminehexaacetic acid content was 0.3 ppm, and the remaining anions were carbonate with a content of 0.1 ppm. The total impurity content of the oxidation product shown in Formula 1 was 0.07%, and the chromaticity was 8.0 Hazen at 90°C.

[0075] Example 4

[0076] The preparation of a storage-stable isophoronenitrile composition comprises the following steps:

[0077] 1) Add 207 g (1.5 mol) of isophorone to a batch reactor made of 316L material, heat to 120°C, add 4.14 g (0.04 mol) of triethylamine, pass 27 g (1.0 mol) of hydrocyanic acid liquid, maintain the temperature at 120°C for 3 h, and obtain an isophorone nitrile reaction solution.

[0078] 2) Add 10.9 g (0.06 mol) of p-toluenesulfonic acid to the isophoronenitrile of step 1), neutralize at 120° C. for 1 h, and then cool to 60° C. to obtain a neutralized reaction solution with a pH of 6.3.

[0079] 3) Add 24.9g of 50ppm triethylenetetraaminehexaacetic acid aqueous solution to the neutralization reaction solution of step 2) for extraction (the mass ratio of aqueous solution to neutralization reaction solution is 1:10), stir at 60°C for 30min, keep warm and stand for 60min, separate the upper organic phase (i.e., the reaction solution containing isophorone nitrile), perform secondary extraction on the obtained organic phase, sample the separated organic phase and test the metal ions, such as iron and nickel, with a total content of 3ppm. The organic phase is directly subjected to vacuum distillation to recover 61g of isophorone, and vacuum distillation is performed to obtain 151g of the product isophorone nitrile composition.

[0080] Gas chromatography test of the isophorone nitrile composition: the isophorone conversion rate is 64.3%, the isophorone nitrile selectivity is 99.0%, and the purity is 99.6%.

[0081] The isophorone nitrile composition product was tested. Based on the mass of isophorone nitrile therein, the metal ions were iron and nickel, with a total content of 0.1 ppm, the triethylenetetraaminehexaacetic acid content was 0.1 ppm, and the remaining anion was p-toluenesulfonic acid with a content of 0.1 ppm. The total impurity content of the oxidation product shown in Formula 1 was 0.08%, and the chromaticity was 8.2 Hazen at 90°C.

[0082] Example 5

[0083] The preparation of a storage-stable isophoronenitrile composition comprises the following steps:

[0084] 1) Add 207 g (1.5 mol) of isophorone to a batch reactor made of 316L material, heat to 120°C, add 2.07 g (0.02 mol) of triethylamine, pass 27 g (1.0 mol) of hydrocyanic acid liquid, maintain the temperature at 120°C for 3 h, and obtain an isophorone nitrile reaction solution.

[0085] 2) Add 5.4 g (0.03 mol) of p-toluenesulfonic acid to the isophoronenitrile of step 1), neutralize at 120° C. for 1 h, and then cool to 60° C. to obtain a neutralized reaction solution with a pH of 6.5.

[0086] 3) Add 12.1g of 50ppm triethylenetetraaminehexaacetic acid aqueous solution to the neutralization reaction solution of step 2) for extraction (the mass ratio of aqueous solution to neutralization reaction solution is 1:20), stir at 60°C for 30min, keep warm and stand for 60min, separate the upper organic phase (i.e., the reaction solution containing isophorone nitrile), perform secondary extraction on the obtained organic phase, sample the separated organic phase and test the metal ions, such as iron and nickel, with a total content of 5ppm. The organic phase is directly subjected to vacuum distillation to recover 61g of isophorone, and vacuum distillation is performed to obtain 151g of the product isophorone nitrile composition.

[0087] Gas chromatography test of the isophorone nitrile composition: the isophorone conversion rate is 64.3%, the isophorone nitrile selectivity is 99.0%, and the purity is 99.6%.

[0088] The isophorone nitrile composition product was tested. Based on the mass of isophorone nitrile therein, the metal ions were iron and nickel, with a total content of 0.2 ppm, the content of triethylenetetraaminehexaacetic acid was not detected, the anion was p-toluenesulfonic acid with a content of 0.4 ppm, the total impurity content of the oxidation product shown in Formula 1 was 0.11%, and the chromaticity was 8.7 Hazen at 90°C.

[0089] Comparative Example 1

[0090] The preparation of a storage-stable isophoronenitrile composition comprises the following steps:

[0091] Steps 1) and 2) are the same as steps 1) and 2) of Example 1;

[0092] 3) Add 23.5g of 300ppm oxalic acid aqueous solution to the neutralization reaction solution of step 2) for extraction (the mass ratio of aqueous solution to neutralization reaction solution is 1:20), stir at 30°C for 60min, keep warm and stand for 60min, separate the upper organic phase (i.e., the reaction solution containing isophorone nitrile), sample and test the metal ions in the organic phase, which are potassium, iron, sodium, nickel, chromium, manganese, etc., with a total content of 230ppm. The organic phase is first subjected to vacuum distillation to recover 267g of isophorone, and then vacuum distilled to obtain 147g of the product isophorone nitrile composition.

[0093] Gas chromatography test of the isophorone nitrile composition: the isophorone conversion rate was 32.0%, the isophorone nitrile selectivity was 99.0%, and the purity was 99.3%.

[0094] The isophorone nitrile composition product was tested. Based on the mass of isophorone nitrile therein, the metal ions were sodium, potassium, iron, nickel, chromium, and manganese, with a total content of 9.3 ppm, the oxalic acid content was 0.2 ppm, and the remaining anions were methanesulfonate with a content of 15 ppm. The total impurity content of the oxidation product shown in Formula 1 was 0.09%, and the chromaticity was 8.1 Hazen at 90°C.

[0095] Comparative Example 2

[0096] The preparation of a storage-stable isophoronenitrile composition comprises the following steps:

[0097] Steps 1) and 2) are the same as steps 1) and 2) of Example 1;

[0098] 3) Add 94g of 10000ppm oxalic acid aqueous solution to the neutralization reaction solution of step 2) for extraction (the mass ratio of aqueous solution to neutralization reaction solution is 1:5), stir at 30°C, stand for 120min, separate the upper organic phase (i.e., the reaction solution containing isophorone nitrile), sample and test the metal ions in the organic phase, which are potassium, iron, sodium, nickel, chromium, manganese, etc., with a total content of 7.6ppm. The organic phase is first subjected to vacuum distillation to recover 265g of isophorone, and then vacuum distilled to obtain 153g of the product isophorone nitrile composition.

[0099] Gas chromatography test of the isophorone nitrile composition: the isophorone conversion rate is 32.2%, the isophorone nitrile selectivity is 99.0%, and the purity is 99.6%.

[0100] The isophorone nitrile composition product was tested. Based on the mass of isophorone nitrile therein, the metal ions were sodium, potassium, and iron, with a total content of 0.2 ppm, the oxalic acid content was 4.9 ppm, and the remaining anion was methanesulfonate with a content of 0.1 ppm. The total impurity content of the oxidation product shown in Formula 1 was 0.10%, and the chromaticity was 8.4 Hazen at 90°C.

[0101] Comparative Example 3

[0102] The steps for preparing a stable storage isophorone nitrile composition are similar to those of Example 1, except that in step 3), the metal extractant oxalic acid aqueous solution is replaced with an aqueous phosphoric acid solution of equal mass and concentration, and other operations remain unchanged.

[0103] Step 3) Sampling and testing the metal ions in the organic phase are potassium, iron, sodium, nickel, chromium, manganese, etc., with a total content of 82ppm. The organic phase is first subjected to vacuum distillation to recover 270g of isophorone, and then vacuum distillation is performed to obtain 148g of the product isophorone nitrile composition.

[0104] Gas chromatography test of the isophorone nitrile composition: the isophorone conversion rate was 32.0%, the isophorone nitrile selectivity was 99.0%, and the purity was 99.5%.

[0105] The isophorone nitrile composition product was tested. Based on the mass of isophorone nitrile therein, the metal ions were sodium, potassium, iron, nickel, and manganese, with a total content of 5.8 ppm, the hydrogen phosphate content was 1.9 ppm, and the remaining anions were methanesulfonate content of 0.1 ppm. The total impurity content of the oxidation product shown in Formula 1 was 0.08%, and the chromaticity was 7.9 Hazen at 90°C.

[0106] Comparative Example 4: Preparation of a stable storage isophorone nitrile composition, the steps are:

[0107] Steps 1) and 2) are the same as steps 1) and 2) of Example 1;

[0108] 3) Add 23.5g of water to the neutralization reaction solution of step 2) for extraction (the mass ratio of water to the neutralization reaction solution is 1:20), stir at 30°C for 60min, and then keep warm for 60min, separate the upper organic phase (i.e., the reaction solution containing isophorone nitrile), sample and test the metal ions in the organic phase, which are potassium, iron, sodium, nickel, chromium, manganese, etc., with a total content of 1046ppm. The organic phase is first subjected to vacuum distillation to recover 262g of isophorone, and then vacuum distilled to obtain 148g of the product isophorone nitrile composition.

[0109] Gas chromatography test of the isophorone nitrile composition: the isophorone conversion rate was 32.1%, the isophorone nitrile selectivity was 99.0%, and the purity was 99.4%.

[0110] The isophorone nitrile composition product was tested. Based on the mass of isophorone nitrile therein, the metal ions were sodium, potassium, iron, nickel, chromium, and manganese, with a total content of 15.7 ppm, the anion was a methanesulfonate content of 19 ppm, the total impurity content of the oxidation product shown in Formula 1 was 0.12%, and the chromaticity was 8.8 Hazen at 90°C.

[0111] 2. Storage stability evaluation of isophoronenitrile composition:

[0112] The isophorone nitrile compositions obtained in Examples 1-5 and Comparative Examples 1-4 were packaged into 50 g glass bottles, protected by nitrogen, and placed in an oven for a 90° C. storage test. The gas phase purity and chromaticity were measured every month, and the test was stopped after 2 months. The results are shown in Table 1.

[0113] Table 1 Storage stability data of isophoronenitrile compositions

[0114]

[0115] As can be seen from Table 1, when the content of metal elements is controlled at 0.1-2.0 ppm, the purity reduction and color number change are within the acceptable range when stored at 90°C for 2 months. In the comparative example, the content of metal elements, the content of metal extractants and the types of extractants were not strictly controlled, and it was found that the purity and color number showed very obvious deterioration during the storage process. Therefore, it is speculated that excessive metal ions may promote the oxidation of isophoronenitrile and generate some colored components, and an appropriate amount of metal extractants will improve the storage stability of isophoronenitrile.

[0116] Those skilled in the art will appreciate that, based on the teachings of this specification, some modifications or adjustments may be made to the present invention, and these modifications or adjustments should also be within the scope defined by the claims of the present invention.

Claims

1. A storage-stable isophorone nitrile composition, characterized in that, The composition contains metal elements, and the total content of the metal elements is ≤2.0 ppm based on the mass of isophoronenitrile in the composition; The composition contains a metal extractant, and the content of the metal extractant is 0.1-2.0 ppm based on the mass of isophoronenitrile in the composition; The metal extractant is selected from any one or a combination of at least two of organic carboxylic acid compounds.

2. The isophorone nitrile composition according to claim 1, wherein The composition contains metal elements, and based on the mass of isophoronenitrile in the composition, the total content of the metal elements is ≤1.0 ppm.

3. The isophorone nitrile composition according to claim 2, characterized in that The composition contains metal elements, and based on the mass of isophoronenitrile in the composition, the total content of the metal elements is ≤0.8 ppm.

4. The isophorone nitrile composition according to claim 1, characterized in that The metal element includes any one of alkali metals, alkaline earth metals, and transition metal elements, or a combination of at least two of them.

5. The isophorone nitrile composition according to claim 4, characterized in that The alkali metal element is sodium and potassium, the alkaline earth metal element is calcium, and the transition metal element is iron, nickel, chromium, and manganese.

6. The isophorone nitrile composition according to claim 1, characterized in that The metal extractant content is 0.3-1.0 ppm.

7. The isophorone nitrile composition according to claim 1, characterized in that The metal extractant is selected from diethylenetriaminepentaacetic acid, triethylenetetraaminehexaacetic acid, and oxalic acid.

8. The isophorone nitrile composition according to claim 1, characterized in that Its storage and transportation temperature is higher than the melting point of isophoronenitrile; After storage at the temperature for 2 months, the impurity content growth value is ≤0.5% based on the mass of isophoronenitrile in the composition; After 2 months storage at the stated temperature, the increase in color is ≤ 5 Hazen.

9. The isophoronenitrile composition according to claim 8, characterized in that The storage and transportation temperature is 75-90°C.

10. The isophoronenitrile composition according to claim 9, characterized in that The storage and transportation temperature is 80-85°C.

11. The isophoronenitrile composition according to claim 8, characterized in that The impurity content growth value is ≤0.3%.

12. The isophoronenitrile composition according to claim 8, characterized in that The increase in chroma is ≤ 3 Hazen.

13. A method for preparing a storage-stable isophorone nitrile composition according to any one of claims 1 to 12, characterized in that: The steps include: 1) isophorone and hydrocyanic acid react under a basic catalyst and heating conditions to obtain an isophorone nitrile reaction solution; 2) adding an acidic substance to the isophoronenitrile reaction solution of step 1) to carry out a neutralization reaction to obtain a neutralization reaction solution; 3) adding a metal extractant to the neutralization reaction solution of step 2) for extraction, and then purifying to obtain the isophorone nitrile composition that can be stably stored; The metal extractant is selected from any one or a combination of at least two of organic carboxylic acid compounds; The metal extractant is prepared as an aqueous solution with a concentration of 50-10000 ppm; The mass ratio of the aqueous solution of the metal extractant to the neutralization reaction liquid is 1:5-20.

14. The preparation method according to claim 13, characterized in that: Step 1) The molar ratio of isophorone to hydrocyanic acid is 1-3:1; The amount of the alkaline catalyst added is 1000-20000ppm based on the mass of isophorone.

15. The preparation method according to claim 14, characterized in that: The molar ratio of isophorone to hydrocyanic acid is 1.5-2:

1.

16. The preparation method according to claim 14, characterized in that: The amount of the alkaline catalyst added is 3000-5000ppm based on the mass of isophorone.

17. The preparation method according to claim 13, characterized in that: Step 1) The alkaline catalyst is selected from any one or a combination of at least two of sodium hydroxide, potassium hydroxide, sodium cyanide, lithium hydroxide, calcium hydroxide, sodium carbonate, potassium carbonate, sodium methoxide, sodium ethoxide, triethylamine, tetramethylammonium hydroxide, tetramethylammonium chloride and tetramethylammonium bromide.

18. The preparation method according to claim 13, characterized in that: Step 1) The reaction temperature is 100-180°C; The reaction is either an intermittent reaction with a reaction time of 0.5-5 hours, or a continuous reaction with an average residence time of 2-10 hours.

19. The preparation method according to claim 18, characterized in that: The reaction temperature is 120-160°C.

20. The preparation method according to claim 18, characterized in that: The intermittent reaction has a reaction time of 1-2 hours.

21. The preparation method according to claim 18, characterized in that: The continuous reaction has an average residence time of 2-10 hours.

22. The preparation method according to claim 21, characterized in that: The average residence time is 3-5h.

23. The preparation method according to claim 13, characterized in that: Step 2) The acidic substance is selected from organic sulfonic acid compounds.

24. The preparation method according to claim 23, characterized in that: The acidic substance is selected from any one or a combination of at least two of methanesulfonic acid, ethanesulfonic acid, propanesulfonic acid, naphthalenemonosulfonic acid, naphthalenedisulfonic acid, naphthalenetrisulfonic acid, dodecylbenzenesulfonic acid, benzenesulfonic acid and p-toluenesulfonic acid.

25. The preparation method according to claim 13, characterized in that: The molar ratio of the acidic substance in step 2) to the alkaline catalyst in step 1) is 1.0-2.0:

1.

26. The preparation method according to claim 25, characterized in that: The molar ratio of the acidic substance to the alkaline catalyst in step 1) is 1.1-1.5:

1.

27. The preparation method according to claim 13, characterized in that: In step 2), the neutralization reaction is carried out at a temperature of 100-180° C. for 0.2-2 h; the pH of the reaction solution after neutralization is 5-8.

28. The preparation method according to claim 27, characterized in that: The neutralization reaction is carried out at a temperature of 120-160° C. and a time of 0.5-1 h.

29. The preparation method according to claim 27, characterized in that: The pH of the reaction liquid after neutralization is 6-7.

30. The preparation method according to claim 13, characterized in that: Step 3) an aqueous solution prepared with a metal extractant, wherein the concentration is 1000-5000 ppm.

31. The preparation method according to claim 13, characterized in that: Step 3) The mass ratio of the aqueous solution of the metal extractant to the neutralization reaction liquid is 1:10-15.

32. The preparation method according to claim 13, characterized in that: Step 3) The extraction temperature is 30-100°C; the average residence time of the extraction process is 5-120min.

33. The preparation method according to claim 32, characterized in that: The extraction temperature is 50-80°C; the average residence time of the extraction process is 20-60 minutes.

34. The preparation method according to claim 13, characterized in that: Step 3) The extraction operation is repeated multiple times, and the content of metal ions in the neutralization reaction solution is controlled to be 0.1-100 ppm of the mass of the reaction solution through the metal extractant extraction operation.

35. The preparation method according to claim 34, characterized in that: The extraction operation was repeated 1-2 times.

36. The preparation method according to claim 34, characterized in that: The metal ion content in the neutralization reaction liquid is controlled to be 1-50 ppm based on the mass of the reaction liquid by the metal extractant extraction operation.

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