Preparation method of narrow-distribution isodecanol polyoxyethylene ether

Abstract

The invention discloses a preparation method of narrow-distribution isodecanol polyoxyethylene ether, which comprises the following steps: adding isodecanol and an alkaline earth metal catalyst into a reaction kettle, and introducing a certain amount of ethylene oxide for reaction to obtain isodecanol polyoxyethylene ether; carrying out programmed cooling on the isodecanol polyoxyethylene ether, crystallizing and separating out components, and filtering to obtain clear filtrate; and carrying out reduced pressure distillation on the filtrate to remove residual isodecanol so as to obtain the narrow-distribution isodecanol polyoxyethylene ether. The obtained product has the characteristics of excellent appearance, low odor and narrow molecular weight distribution.

Description

Technical Field

[0001] The invention relates to polyether polyols, in particular to a preparation process of isomeric decanol polyoxyethylene ether. Background Art

[0002] Isomeric decanol polyoxyethylene ether is a non-ionic surfactant product grafted with ethylene oxide starting with isomerized decanol. It is widely used in civil and industrial fields such as textiles, leather, industrial and commercial cleaning, oil field additives, emulsion polymerization, etc. It is used to produce penetrants, refining agents, degreasing agents, emulsifiers, etc.

[0003] The industrialization method of isomeric alcohol polyoxyethylene ether basically uses traditional alkaline catalysts such as KOH. The molecular weight distribution of the product is relatively wide, and its performance is inferior to that of narrow distribution products. The narrower the product distribution in customer application, the more prominent its performance characteristics are, and the formula can be well adjusted according to its characteristics. In addition, isomeric decanol itself has a strong odor. Controlling the narrow distribution of the product can reduce the residual amount of isomeric decanol, thereby obtaining a low-odor product and providing a better customer experience.

[0004] Patent CN102634005A uses alkaline earth metal catalyst calcium acetate and o-hydroxybenzoic acid as a composite catalyzer to prepare isomeric alcohol polyoxyethylene ethers, which utilizes the narrow distribution catalytic properties of alkaline earth metal salts. However, there is still room for further improvement in its distribution. At the same time, the isomeric alcohol residues are not separated, which will also affect the odor and distribution. In addition, the typical problem of alkaline earth metal type catalysts is the poor compatibility between the catalyst and the isomeric alcohol ethers. The appearance is still turbid even in the heated state, and the customer's sensory perception is poor. Patent CN108102084B uses alkaline earth metal calcium sulfate and conventional KOH composite catalysis to prepare narrow distribution isomeric alcohol polyoxyethylene ethers. The polydispersity index PDI of the obtained product is 1.04-1.1. Compared with conventional KOH catalysis, although it is narrower, due to the presence of some high molecular weight components and low molecular weight isomeric alcohol residues, the distribution is still relatively wide, and there are problems of turbid appearance and strong odor at room temperature. In addition, the calcium sulfate component is insoluble in the isomeric alcohol ether. This turbidity is different from that caused by the high freezing point of the high molecular weight component. It cannot be eliminated even by heating, resulting in the product being always turbid regardless of high or low temperature conditions, thereby causing the color number index to be always high.

[0005] The prior art generally prepares narrow distribution isomeric alcohol ethers through narrow distribution catalysts, such as alkaline earth metal salts, but this method has two defects. On the one hand, alkaline earth metal salt catalysis cannot completely eliminate high molecular weight components and low molecular weight isomeric alcohol residues, so the distribution cannot be as narrow as possible. Summary of the invention

[0006] In order to solve the above technical problems, the present invention provides a preparation method of narrow distribution isomeric decanol polyoxyethylene ether. The present invention prepares a crude isomeric decanol polyoxyethylene ether product under the action of a narrow distribution alkaline earth metal catalyst, and through programmed cooling and freezing crystallization, it is found that the alkaline earth metal catalyst can be crystallized together with the high freezing point component in the product, thereby achieving separation, obtaining a product with excellent appearance, and removing the high freezing point component with a high ethylene oxide addition number, and then removing the residual alcohol through vacuum distillation, the obtained product has an extremely narrow distribution and low odor.

[0007] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0008] A preparation method of narrow distribution isomeric decanol polyoxyethylene ether comprises the following steps: adding isomeric decanol and an alkaline earth metal catalyst into a reaction kettle, introducing a certain amount of ethylene oxide for reaction, and obtaining isomeric decanol polyoxyethylene ether; subjecting the isomeric decanol polyoxyethylene ether to programmed cooling, filtering the crystallized components to obtain a clear filtrate; and removing residual isomeric decanol from the filtrate by reduced pressure distillation to obtain narrow distribution isomeric decanol polyoxyethylene ether.

[0009] In some examples, the alkaline earth metal catalyst is at least one of calcium isopropoxide, calcium isobutoxide, and calcium tert-butoxide.

[0010] In some examples, the amount of the alkaline earth metal catalyst used is 0.1-0.4% by mass of the isomeric decanol, such as 0.1%, 0.2%, 0.3%, 0.4%, etc.

[0011] In some examples, the molar ratio of ethylene oxide to isodecanol is (5-10):1, such as 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, etc.

[0012] In some examples, the reaction temperature is 130-165°C, such as 130°C, 140°C, 150°C, 165°C, etc.

[0013] In some examples, the initial temperature of the programmed cooling is 40-50°C, such as 40°C, 45°C, 50°C, etc.

[0014] In some examples, the cooling rate of the programmed cooling is 7-13°C / h, such as 7°C / h, 9°C / h, 11°C / h, 13°C / h, etc.

[0015] In some examples, the endpoint temperature of the programmed cooling is 17-23°C, such as 17°C, 19°C, 21°C, 23°C, etc.

[0016] In some examples, the reduced pressure distillation temperature of the filtrate is 120-130°C, such as 120°C, 125°C, 130°C, etc.

[0017] In some examples, the reduced pressure distillation pressure of the filtrate is 0.06-0.1 kPa(A), such as 0.06 kPa(A), 0.08 kPa(A), 0.1 kPa(A), etc.

[0018] The invention utilizes the characteristic of a high molecular weight component having a high freezing point, and uses a crystallization process to precipitate the component, thereby ensuring that the product has a good appearance within a room temperature range, and the product is clear and transparent without stratification. At the same time, the invention utilizes reduced pressure distillation to remove low molecular weight isomeric alcohols with a strong odor, thereby further narrowing the product distribution and eliminating the product odor. On the other hand, the invention solves the defect that alkaline earth metal salts cannot be miscible with isomeric alcohol ethers through a cooling crystallization process, and also completely solves the problem that the product is still turbid in a high temperature state.

[0019] The isomeric decanol polyoxyethylene ether prepared by the present invention has the advantages of excellent appearance, low odor and narrow molecular weight distribution. DETAILED DESCRIPTION

[0020] The present invention is further described below by means of specific examples. The examples described in the present invention are only used to illustrate the present invention and do not limit the scope of the present invention.

[0021] The isomeric decanol used in the present invention is produced from Shenhua Baotou Coal Chemical Industry Co., Ltd., and the other raw materials and reagents, unless otherwise specified, can be obtained through commercial channels.

[0022] The main test methods are:

[0023] Chroma: Color number is measured according to the national standard GB / T9282.1-2008;

[0024] Residual alcohol: measured by Shimadzu 1020-Plus gas chromatograph;

[0025] Polydispersity index (PDI): measured by PL-GPC220 gel permeation chromatography with tetrahydrofuran as the mobile phase.

[0026] The "parts" described in the following examples are all parts by mass.

[0027] Example 1

[0028] 158 parts of isomeric decanol and 0.158 parts of calcium isopropoxide were added to a reactor, the temperature was raised to 130°C, 220 parts of ethylene oxide were introduced for reaction, the reaction temperature was controlled at 130°C, and the reactor pressure was aged after the feeding was completed until the reactor pressure no longer decreased to obtain a crude isomeric decanol polyoxyethylene ether product, which was put into a frozen crystallizer, the initial temperature was controlled to 40°C, the program was set to cool, the cooling rate was set to 7°C / h, and after the terminal temperature of 17°C was reached, the suspension in the crystallizer was added to a positive pressure filter for filtration, the filter jacket temperature was controlled to 17°C, the filtration pressure was 0.1MPa, and after the filtration was completed, the filtrate was subjected to reduced pressure distillation at 120°C and 0.06kPa (A) to obtain a narrow distribution isomeric decanol polyoxyethylene ether product with a 50°C color number of 3hazen, 0.013% residual alcohol, and PDI=1.009.

[0029] Example 2

[0030] 158 parts of isomeric decanol and 0.632 parts of calcium isobutoxide were added to a reactor, the temperature was raised to 165°C, 440 parts of ethylene oxide were introduced for reaction, the reaction temperature was controlled at 165°C, and after the feeding was completed, the reactor was aged until the reactor pressure no longer decreased to obtain a crude isomeric decanol polyoxyethylene ether product, which was put into a frozen crystallizer, the initial temperature was controlled to be 50°C, the program was set to cool, the cooling rate was set to 13°C / h, and after the terminal temperature of 23°C was reached, the suspension in the crystallizer was added to a positive pressure filter for filtration, the filter jacket temperature was controlled to be 23°C, the filtration pressure was 0.1MPa, and after the filtration was completed, the filtrate was subjected to reduced pressure distillation at 130°C and 0.1kPa (A) to obtain a narrow distribution isomeric decanol polyoxyethylene ether product with a 50°C color number of 4hazen, 0.011% residual alcohol, and PDI=1.007.

[0031] Example 3

[0032] 158 parts of isomeric decanol and 0.316 parts of calcium tert-butoxide are added to a reactor, the temperature is raised to 150°C, 308 parts of ethylene oxide are introduced for reaction, the reaction temperature is controlled at 150°C, and after the feeding is completed, the reactor is aged until the reactor pressure no longer decreases to obtain a crude isomeric decanol polyoxyethylene ether product, which is put into a frozen crystallizer, the initial temperature is controlled to be 45°C, the program cooling is set, the cooling rate is set to 9°C / h, and after the terminal temperature of 20°C is reached, the suspension in the crystallizer is added to a positive pressure filter for filtration, the filter jacket temperature is controlled to be 20°C, and the filtration pressure is 0.1MPa. After the filtration is completed, the filtrate is subjected to reduced pressure distillation at 125°C and 0.08kPa (A) to obtain a narrow distribution isomeric decanol polyoxyethylene ether product with a 50°C color number of 4hazen, 0.012% residual alcohol, and PDI=1.008.

[0033] Comparative Example 1

[0034] The isomeric decanol polyoxyethylene ether was prepared in the same manner as in Example 1, except that the freezing crystallization and reduced pressure distillation were not performed. The product obtained by this process had a color number of 32 hazen at 50°C, residual alcohol of 9.2%, and PDI = 1.245.

[0035] Comparative Example 2

[0036] The isomeric decanol polyoxyethylene ether was prepared in the same manner as in Example 1, except that the freezing crystallization operation was not performed. The product obtained by this process had a color number of 31 hazen at 50°C, residual alcohol of 0.013%, and PDI = 1.217.

[0037] Comparative Example 3

[0038] The isomeric decanol polyoxyethylene ether was prepared in the same manner as in Example 1, except that the vacuum distillation operation was not performed. The product obtained by this process had a color number of 4 hazen at 50°C, residual alcohol of 9.3%, and PDI of 1.193.

[0039] Comparative Example 4

[0040] The isomeric decanol polyoxyethylene ether was prepared in the same manner as in Example 1, except that the catalyst was replaced by KOH in equal amounts from alkaline earth metal salts, and finally neutralized with acetic acid in an equal molar amount to KOH. The product obtained by this process had a color number of 5 hazen at 50°C, residual alcohol of 0.016%, and PDI = 1.084.

[0041] From the above test results, it can be seen that the form of frozen crystallization can effectively remove alkaline earth metal salts, so that the 50°C color number of the product is ≤5, with excellent appearance; after the residual isomeric decanol is removed by vacuum distillation, the alcohol residue is extremely low, ensuring the low odor of the product; after the low molecular residual alcohol and high ethylene oxide addition group components are removed, the molecular weight distribution of the obtained product is greatly narrowed compared to the commercially available conventional KOH-catalyzed isomeric decanol polyoxyethylene ether (PDI is about 1.3). In addition, according to the results of Comparative Example 4, the method of frozen crystallization and vacuum distillation of the present invention also has the effect of significantly reducing the odor and narrowing the molecular weight distribution for conventional KOH-catalyzed isomeric decanol polyoxyethylene ether.

[0042] The above is only a preferred embodiment of the present invention. It should be pointed out that ordinary technicians in this field can make several improvements and supplements without departing from the method of the present invention. These improvements and supplements should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing narrow distribution isomeric decanol polyoxyethylene ether, comprising the following steps: Add isomeric decanol and an alkaline earth metal catalyst into a reaction kettle, introduce a certain amount of ethylene oxide for reaction, and obtain isomeric decanol polyoxyethylene ether; subject the isomeric decanol polyoxyethylene ether to programmed cooling, and filter the crystallized components to obtain a clear filtrate; remove residual isomeric decanol from the filtrate by reduced pressure distillation to obtain narrow distribution isomeric decanol polyoxyethylene ether.

2. The method according to claim 1, characterized in that The alkaline earth metal catalyst is one or more of calcium isopropoxide, calcium isobutoxide, and calcium tert-butoxide.

3. The method according to claim 1 or 2, characterized in that: The amount of the alkaline earth metal catalyst used is 0.1-0.4% of the mass of the isomeric decanol.

4. The method according to any one of claims 1 to 3, characterized in that: The molar ratio of ethylene oxide to isomeric decanol is (5-10):

1.

5. The method according to any one of claims 1 to 4, characterized in that: The reaction temperature is 130-165°C.

6. The method according to any one of claims 1 to 5, characterized in that: The initial temperature of the programmed cooling is 40-50°C.

7. The method according to any one of claims 1 to 6, characterized in that: The cooling rate of the programmed cooling is 7-13°C / h.

8. The method according to any one of claims 1 to 7, characterized in that: The terminal temperature of the programmed cooling is 17-23°C.

9. The method according to any one of claims 1 to 8, characterized in that: The filtrate is distilled under reduced pressure at a temperature of 120-130°C.

10. The method according to any one of claims 1 to 9, characterized in that: The reduced pressure distillation pressure of the filtrate is 0.06-0.1 kPaA.