WO2020248483A1 - Preparation process of stearate - Google Patents

Abstract

Disclosed is a preparation process of stearate, which is a method for preparing stearate by directly reacting a metal oxide or hydroxide with stearic acid. The process not only has simple steps, uses a small number of devices, requires a small amount of investment, and produces no waste liquid, but also eliminates environmental pollution, saves a lot of caustic soda, and reduces the cost of products. Moreover, the loss of raw materials during the process is low, so that the yield of the product is increased. The yield of finished stearate is more than 98% on the basis of stearic acid. In addition, because no other salts are produced during the preparation process, the content of inorganic salts in the stearate product is low, thereby facilitating the improvement of the quality of products.

Description

A kind of preparation process of stearate Technical field

The invention relates to the technical field of fine chemicals, in particular to a preparation process of stearate.

Background technique

At present, the industrial preparation of calcium stearate, barium, zinc, lead, magnesium and other metal oxides and hydroxides of which are hardly soluble in water, adopts the water method (double decomposition method) and anhydrous method (dry method) The metathesis method firstly reacts stearic acid and sodium oxide to produce sodium stearate during preparation, and then uses the prepared sodium stearate and the corresponding metal water-soluble salt for metathesis reaction, so as to finally obtain the required Stearate. The advantage of the metathesis method is that the reaction is easy to proceed and the process operation is easy to master. However, a large amount of sodium hydroxide is consumed in the process, and the sodium is finally converted into sodium salt and discharged with the waste liquid. Therefore, the sodium hydroxide used is wasted in vain, followed by the stearate formed by metathesis. Contains a large amount of inorganic salts, it needs to consume a lot of hot water for washing, the water content of the washed stearate is high, and the heat consumption is large during dehydration and drying. Furthermore, a large amount of salt-containing wastewater is discharged during the production process. Environmental pollution, especially the waste water discharged during the production of lead, magnesium and other stearates not only contains a large amount of inorganic salts, but also contains lead and magnesium ions that are toxic to humans and organisms. The double decomposition method consumes a large amount of sodium hydroxide, high energy consumption and long process, resulting in high production cost of stearate. In addition, the double decomposition method also has the disadvantages of long production process, multiple equipment, and large investment in tooling equipment.

When the anhydrous method (dry method) is used to prepare stearate, firstly, the stearic acid is heated and melted, oxide or hydroxide is added, and the catalyst is added at the same time to react in the molten state. The material is cooled by tableting or other Process to get the product. Although this method is widely used, the method has uneven reaction, splashing of materials during the reaction, and bath pot phenomenon, incomplete reaction, and many unreacted raw materials in the product. Therefore, the equipment feeding coefficient is very low and the efficiency is low.

In response to the above problems, CN103880631A discloses a method for preparing stearate, that is, stearic acid, metal compounds, and deionized water are first subjected to heat preservation reaction, and then a catalyst is added for stirring and heating, and the finished product is finally obtained, although the method is directly Stearate and metal compounds are used to avoid the problem of excessive sodium salt in wastewater. However, the preparation time of this method is too long and the actual promotion value is low.

CN 1837176A discloses a method for preparing metal stearate, that is, under normal pressure, stearic acid, metal hydroxide (or oxide or carbonate) and medium water are stirred below the melting point of stearic acid, and then It is heated to above the melting point of stearic acid for reaction, and the reaction product is dehydrated, dispersed and dried to obtain metal stearate. Although this method overcomes some shortcomings of the double decomposition method and the dry method, the stearate prepared by this method is in powder form, and it is very difficult to control its wetness, and it will inevitably affect the performance of plastic products during use.

CN107311855A discloses a method for preparing stearate. The method includes first melting stearic acid to obtain material A, stirring and grinding water and part of the metal oxide, and then adding the remaining metal oxide and catalyst to stirring and grinding to obtain material B The temperature of A and B reacts to finally get molten stearate. This method avoids the defects of intense reaction and uneven reaction. However, as the reaction heats up, the catalyst will gradually become invalid, resulting in unstable production process, and also due to the breakdown of the catalyst. And doped with impurities.

Therefore, how to provide a stearate preparation process with short production process, low energy consumption, high yield and high purity is a technical problem to be solved by those skilled in the art.

Summary of the invention

In view of this, the technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a stearate preparation process with short production process, low energy consumption, low investment and high yield. The preparation process is made of metal Oxide or hydroxide and stearic acid are directly reacted to prepare stearate that is hardly soluble in water when the metal ions in the stearate molecule are in the presence of oxides or hydroxides. Waste liquid is produced, and the finished product does not contain other inorganic salts and has high purity.

In order to achieve the above objectives, the present invention provides the following technical solutions:

A preparation process of stearate, the process specifically includes the following steps:

Weigh the stearic acid and the metal compound, and add the stearic acid and the metal compound to the reactor in turn, and then add a certain catalyst;

In step (1), the inside of the reactor is filled with inert gas to pressurize, followed by stirring and heating, and reacting for a certain period of time to obtain the stearate product coarse powder;

The coarse powder of the stearate product obtained in step (2) is pulverized to finally obtain a white powder product of stearate.

Preferably, in the step (1), the amount of stearic acid and the metal compound added is based on a stoichiometric ratio, wherein the metal compound is ground and passed through a 200 mesh screen.

Preferably, in the step (1), the amount of the catalyst is 0.1% to 0.2% of the total material mass; the catalyst is hydrogen peroxide, water, maleic anhydride or benzoic acid.

Preferably, in the step (2), the reaction pressure is controlled between 0.40 and 0.70 MPa, the reaction temperature is controlled between 65°C and 105°C, and the reaction time is controlled between 3 hours and 5 hours.

Preferably, the metal compound is a metal oxide or hydroxide, and the metal oxide or hydroxide includes zinc oxide, magnesium oxide, magnesium hydroxide, calcium hydroxide or calcium oxide.

Preferably, the stearate is zinc stearate, the metal oxide or hydroxide is zinc oxide, and the added amount of the catalyst is 0.15% to 0.20% of the total weight of the zinc oxide and stearic acid. , The reaction pressure is 0.5-0.7MPa, the reaction temperature is 65-95°C, and the reaction time is 4-5h.

Preferably, the stearate is magnesium stearate, the metal oxide or hydroxide is magnesium oxide or magnesium hydroxide, and the addition amount of the catalyst is magnesium oxide or magnesium hydroxide and stearic acid. 0.1-0.15% of the total weight, the reaction pressure is 0.4-0.7MPa, the reaction temperature is 65-105°C, and the reaction time is 3-5h.

Preferably, the stearate is calcium stearate, the metal oxide or hydroxide is calcium oxide or calcium hydroxide, and the added amount of the catalyst is calcium oxide or calcium hydroxide and stearic acid. 0.1% to 0.2% of the total weight, the reaction pressure is 0.4 to 07MPa, the reaction temperature is 65 to 95°C, and the reaction time is 4 to 5 hours.

It can be known from the above technical solutions that, compared with the prior art, the preparation process of stearate provided by the present invention has the following excellent features:

1. The metal compound in the present invention can better evenly react with stearic acid after being ground and pretreated, the reaction is complete, and the product quality obtained is more uniform;

2. The present invention has fast reaction speed, easy control, and can save 60-80% of the reaction time;

3. The quality of the product obtained by the present invention is more stable and superior. Because the direct use of stearic acid and metal compounds has fewer reaction steps, there is no waste water in the process, and there is no quality problem caused by excessive sodium salt or washing differences;

4. In the preparation process of stearate disclosed in the present invention, deionized water is used to participate in the reaction, which effectively reduces or eliminates the interference of impurity ions during the reaction;

5. Since the present invention is carried out below the melting point of the product, if there is no pressure, in the actual production process, the product will quickly reach the melting and softening point due to the exothermic heat of the system, so that the agglomeration reaction of materials cannot be completed completely, and the reactor is filled with inertness The gas can ensure that the product does not agglomerate, and the entire reaction system is in a fully dispersed state at all times. Therefore, the applicant obtained through creative experiments to fill the reactor with inert gas and pressurize it to 0.40～0.70MPa, so as to ensure the normal progress of the final reaction.

In summary, the preparation process of stearate disclosed in the present invention not only has short process flow, low equipment consumption, low investment, and no waste liquid generation, but also eliminates environmental pollution, saves a lot of caustic soda, and reduces product cost. The cost, and the process loss of raw materials is small, which is beneficial to increase the yield of the product. The yield of the finished stearate is above 98% based on stearic acid.

In addition, since no other salts are produced during the preparation process, the content of inorganic salts in the stearate product is low, which is beneficial to improve the quality of the product. Therefore, the technical scheme disclosed in the present invention is suitable for promotion and application.

Description of the drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only It is an embodiment of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on the provided drawings without creative work.

Figure 1 is an infrared spectrogram of zinc stearate obtained in Example 1 of the present invention;

Figure 2 is a DSC data analysis chart of zinc stearate obtained in Example 1 of the present invention;

Figure 3 is an infrared spectrogram of magnesium stearate obtained in Example 2 of the present invention;

Figure 4 is an infrared spectrogram of calcium stearate obtained in Example 5 of the present invention;

Fig. 5 is a DSC data analysis chart of calcium stearate obtained in Example 5 of the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention and the accompanying drawings of the specification. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

The embodiment of the invention discloses a stearate preparation process with short production process, low energy consumption, low investment and high yield.

In order to better understand the present invention, the following examples will further illustrate the present invention in detail, but it should not be construed as a limitation to the present invention. For those skilled in the art, some non-essential improvements and adjustments made based on the above-mentioned invention content, It is also deemed to fall within the protection scope of the present invention.

In the following, the technical solution of the present invention will be further described in conjunction with specific embodiments.

Example one

A preparation process of zinc stearate, the process specifically includes the following steps:

(1) Weigh 500kg stearic acid and 75.5kg zinc oxide, the metal compound is ground and passed through a 200-mesh screen, then stearic acid and zinc oxide are sequentially added to the reaction kettle, and then 0.86kg benzoic acid is added.

(2) Fill the interior of the reactor in step (1) with an inert gas and pressurize it to 0.6 MPa, then stir and raise the temperature to 80° C. and react for 4 hours to obtain coarse zinc stearate powder.

(3) The zinc stearate coarse powder obtained in step (2) is pulverized to finally obtain zinc stearate white powder.

(4) Use a differential scanning calorimeter to analyze the purity of the powder product obtained in step (3).

Table 1 shows the detection and analysis results of zinc stearate products in the present invention.

Table 1:

Test items	standard value	Test value
Melting point,℃	115～125	123
Free fatty acid,%	≤0.5	0.32
Zinc,%	10.3～11.3	10.65
Heating loss (105℃×2h),％	≤1.0	0.86

Example two

A preparation process of magnesium stearate, the process specifically includes the following steps:

(1) Weigh 500 kg of stearic acid and 31.5 kg of magnesium oxide, the metal compound is ground and passed through a 200-mesh screen, then stearic acid and zinc oxide are sequentially added to the reactor, and then 0.53 kg of water is added.

(2) Fill the inside of the reactor of step (1) with inert gas and pressurize to 0.55 MPa, then stir and raise the temperature to 80° C. and react for 4.5 hours to obtain coarse magnesium stearate powder.

(3) Crushed the coarse magnesium stearate powder obtained in step (2), and finally obtain a white powder product of magnesium stearate.

(4) Use a differential scanning calorimeter to analyze the purity of the powder product obtained in step (3).

Example three

A preparation process of magnesium stearate, the process specifically includes the following steps:

(1) Weigh 500 kg of stearic acid and 61 kg of magnesium hydroxide, the metal compound is ground and passed through a 200-mesh screen, then stearic acid and zinc oxide are sequentially added to the reactor, and then 0.82 kg of maleic anhydride is added.

(2) Fill the inside of the reactor in step (1) with an inert gas and pressurize it to 0.5 MPa, then stir and raise the temperature to 65° C. and react for 5 hours to obtain coarse magnesium stearate powder.

(3) Crushed the coarse magnesium stearate powder obtained in step (2), and finally obtain a white powder product of magnesium stearate.

(4) Use a differential scanning calorimeter to detect the powder product obtained in step (3) for analysis.

Table 2 shows the detection and analysis results of magnesium stearate products in the present invention.

Table 2: Standard values: melting point ≧95°C, magnesium 4.0～5.0%, moisture content ≤3.0%

To	Example two	Example three
Melting point,℃	119.4	119
magnesium,%	4.41	4.43
Moisture,%	3.83	3.86

Example four

A preparation process of calcium stearate, the process specifically includes the following steps:

(1) Weigh 500 kg of stearic acid and 54 kg of calcium oxide, the metal compound is ground and passed through a 200-mesh screen, then stearic acid and zinc oxide are sequentially added to the reactor, and then 0.55 kg of hydrogen peroxide is added.

(2) Fill the inside of the reactor in step (1) with an inert gas and pressurize it to 0.7 MPa, then stir and raise the temperature to 95° C. and react for 5 hours to obtain coarse calcium stearate powder.

(3) Crushed the coarse calcium stearate powder obtained in step (2) to finally obtain a white powder product of calcium stearate.

(4) Use a differential scanning calorimeter to analyze the purity of the powder product obtained in step (3).

Example five

A preparation process of calcium stearate, the process specifically includes the following steps:

(1) Weigh 500 kg of stearic acid and 71 kg of calcium hydroxide, the metal compound is ground and passed through a 200-mesh screen, then stearic acid and zinc oxide are sequentially added to the reaction kettle, and then 1.1 kg of water is added.

(2) Fill the inside of the reactor in step (1) with an inert gas and pressurize it to 0.6 MPa, then stir and raise the temperature to 80° C. and react for 4 hours to obtain coarse calcium stearate powder.

(3) Crushed the coarse calcium stearate powder obtained in step (2) to finally obtain a white powder product of calcium stearate.

(4) Use a differential scanning calorimeter to analyze the purity of the powder product obtained in step (3).

Table 3 shows the results of detection and analysis of magnesium stearate products in the present invention.

table 3:

Standard value: melting point 149～155℃, free fatty acid≤0.5%, calcium 6.6～7.1%, heating loss≤2.0%

To	Melting point,℃	Free fatty acid,%	calcium,%	Heating loss,%
Example four	151	0.48	6.95	2.67
Example five	152	0.45	6.88	2.65

Example Six

The composition of the white powder obtained in the present invention was analyzed by infrared spectroscopy, and the analysis results are as follows:

Table 1:

In addition, the applicant also conducted the following comparative test of "filling the interior of the reactor with inert gas to pressurize the step (1)" as described in the first embodiment above, and the details are as follows:

Comparative example 1:

The difference from the first embodiment is that in step (2), "fill the inside of the reactor in step (1) with an inert gas and pressurize it to 0.6MPa, and then stir..." is modified to "to step (1) Fill the inside of the reactor with inert gas and pressurize to 0.1MPa, then stir...", the rest of the process steps and process parameters remain unchanged.

Comparative example two:

The difference from the first embodiment is that in step (2), "fill the inside of the reactor in step (1) with an inert gas and pressurize it to 0.6MPa, and then stir..." is modified to "to step (1) The inside of the reactor is filled with inert gas and pressurized to 0.2MPa, and then stirred...", the rest of the process steps and process parameters remain unchanged.

Comparative example three:

The difference from the first embodiment is: in step (2), "fill the inside of the reactor in step (1) with inert gas and pressurize it to 0.6 MPa, and then stir..." is modified to "step ( 1) The internal stirring of the reactor......", the remaining process steps and process parameters remain unchanged.

The zinc stearate product powder publicly prepared in the above-mentioned comparative example 1 to comparative example 3 was compared and analyzed with the zinc stearate product powder publicly prepared in the examples, and the following detection and analysis results were obtained:

Table 4:

Test items	standard value	Example one	Comparative example one	Comparative example two	Comparative example three
Free fatty acid,%	≤0.5	0.32	18.9	13.6	27.4

The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown in this document, but should conform to the widest scope consistent with the principles and novel features disclosed in this document.

Claims (8)

1. A preparation process of stearate, which is characterized in that the process specifically includes the following steps:

   (1) Weigh the stearic acid and the metal compound, and add the stearic acid and the metal compound to the reactor in turn, and then add a certain catalyst;

   (2) Fill the interior of the reaction kettle with inert gas for pressure in step (1), then stir and raise the temperature, react for a certain period of time to obtain the crude stearate product;

   (3) Crushed the coarse powder of the stearate product obtained in step (2) to finally obtain a white powder product of stearate.
2. The preparation process of a stearate according to claim 1, characterized in that, in the step (1), the amount of stearic acid and the metal compound added is calculated according to the stoichiometric ratio, wherein the metal compound is Grind and pass through a 200 mesh screen.
3. The preparation process of stearate according to claim 1, wherein in the step (1), the amount of the catalyst is 0.1% to 0.2% of the total material mass; the catalyst is hydrogen peroxide, Water, maleic anhydride or benzoic acid.
4. The preparation process of stearate according to claim 1, characterized in that, in the step (2), the reaction pressure is controlled between 0.40 and 0.70MPa, and the reaction temperature is controlled between 65°C and 105°C. In between, the reaction time is controlled between 3 and 5 hours.
5. The preparation process of stearate according to any one of claims 1 to 3, wherein the metal compound is a metal oxide or hydroxide, and the metal oxide or hydroxide includes an oxide Zinc, magnesium oxide, magnesium hydroxide, calcium hydroxide or calcium oxide.
6. The preparation process of stearate according to claim 5, wherein the stearate is zinc stearate, the metal oxide or hydroxide is zinc oxide, and the catalyst is The added amount is 0.15% to 0.20% of the total weight of zinc oxide and stearic acid, the reaction pressure is 0.5 to 0.7 MPa, the reaction temperature is 65 to 95° C., and the reaction time is 4 to 5 hours.
7. The preparation process of stearate according to claim 5, wherein the stearate is magnesium stearate, and the metal oxide or hydroxide is magnesium oxide or magnesium hydroxide, The added amount of the catalyst is 0.1 to 0.15% of the total weight of the magnesium oxide or magnesium hydroxide and stearic acid, the reaction pressure is 0.4 to 0.7 MPa, the reaction temperature is 65 to 105° C., and the reaction time is 3 to 5 hours.
8. The preparation process of stearate according to claim 5, wherein the stearate is calcium stearate, and the metal oxide or hydroxide is calcium oxide or calcium hydroxide, The added amount of the catalyst is 0.1% to 0.2% of the total weight of calcium oxide or calcium hydroxide and stearic acid, the reaction pressure is 0.4 to 07 MPa, the reaction temperature is 65 to 95° C., and the reaction time is 4 to 5 hours.

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