Preparation process of high-purity antistatic agent

Abstract

In the scheme, the molecular weight of finished product antistatic polymer sulfone is limited to facilitate the subsequent removal of a solvent, and the theoretical basis is that along with the removal of the solvent, the viscosity of the antistatic agent composition material is increased, so that the solvent is prevented from being removed from the material; benzene, methylbenzene and the like in a finished product antistatic agent cannot be controlled within a required range, the solvent can be continuously removed only by continuously heating, the antistatic effect of a polymer is easily attenuated along with the prolonging of time, and when the molecular weight of polymer sulfone is reduced within a limited range, the viscosity of the material is reduced, the temperature for removing the solvent is reduced, the time is shortened, and the cost is reduced. And the antistatic effect is good.

Description

Technical Field

[0001] The invention relates to the technical field of antistatic agents, and in particular to a preparation process of a high-purity antistatic agent. Background Art

[0002] Antistatic agents, such as 425 antistatic agent, are often used in the preparation of polyolefins. Excessive solvents and moisture are generally left in the finished 425 antistatic agent. Solvents such as benzene, toluene, xylene, etc. are toxic components in the preparation of polyolefins and must be strictly limited within the required range, such as less than 1000ppm. Residual moisture can easily affect the catalyst in the preparation of polyolefins, so the moisture must also be strictly limited within the required range.

[0003] The removal of solvents, moisture, etc. in the finished antistatic agent is generally carried out under the protection of inert gas, vacuuming and heating to remove the solvents, moisture, etc., but heating to a lower temperature often cannot remove the solvents, moisture, etc. to the required level, and long-term high-temperature treatment can easily lead to the attenuation of the antistatic effect of the antistatic agent, which needs to be improved. Summary of the invention

[0004] To solve at least one of the above technical defects, the present invention provides the following technical solutions:

[0005] This application document discloses a preparation process of a high-purity antistatic agent, comprising the following steps:

[0006] Solvent Removal Steps:

[0007] The molecular weight of the polysulfone of the finished antistatic agent is 3000-12000. The solvent in the finished antistatic agent is removed by heating, vacuuming, purging with inert gas and stirring to form a solid conductive polymer.

[0008] Water removal steps:

[0009] The cooled solid conductive polymer is dissolved in n-heptane, and a dehydrating agent is added to perform closed dehydration.

[0010] In this scheme, the molecular weight of the finished antistatic polysulfone is limited to facilitate the subsequent removal of the solvent. The theoretical basis is that as the solvent is removed, the viscosity of the antistatic agent composition material increases, thereby preventing the solvent from being removed from the material, resulting in the inability to control benzene, toluene, etc. in the finished antistatic agent within the required range. The temperature must be continued to be raised before the solvent can be removed, and the antistatic effect of the polymer is easily attenuated over time. When the molecular weight of the polysulfone is reduced within the limited range, the viscosity of the material is reduced, the temperature of the solvent removal is reduced, the time is shortened, and the antistatic effect is good.

[0011] After dissolving in n-heptane solvent, the water can be removed by a dehydrating agent. This method can more effectively control the water content in the material within the required range, such as below 1000ppm. After the solvent and water content are removed to a limited range, the antistatic agent can be effectively used in the preparation of polyolefins.

[0012] Furthermore, in the solvent removal step: an inert gas is passed, and the finished antistatic agent is heated to 80-120°C while stirring. After the solvent content reaches the standard, the heating is stopped and the inert gas is passed to cool the solid conductive polymer to 30-45°C. Solvents such as benzene, toluene, and xylene in the finished antistatic agent can be removed at 80-120°C, and this temperature will not affect the antistatic effect of the polymer.

[0013] Furthermore, in the water removal step: the dehydrating agent is selected from molecular sieves, which are easy to purchase and have a good dehydration effect.

[0014] Furthermore, sampling is performed at intervals during the closed water removal process until the moisture content is below 1000 ppm.

[0015] Furthermore, the finished antistatic agent is 425 type.

[0016] For finished antistatic agents, they can be purchased directly from the market, such as purchasing models with molecular weights within a limited range. Of course, they can also be synthesized by themselves, such as;

[0017] Preparation of finished antistatic agent: Preparation of finished antistatic agent: Monomer - alpha olefin, sulfur dioxide, n-heptane, initiator - dimethyl azobisisobutyrate in a mass ratio of 3-5:2-4:0.4-0.6:2-3, react at 25-35 ° C to generate conductive polymer, the conductive polymer and polyamine compound are mixed to form the finished antistatic agent. Self-synthesis can more effectively control the molecular weight of polysulfone within a limited range, which is convenient for subsequent water and solvent removal.

[0018] Furthermore, the mass ratio of the polyamine compound to the polyamine compound in the finished antistatic agent is 0.5:1-1:1. It was accidentally discovered that the antistatic agent with this ratio has more stable temperature resistance and the antistatic effect remains stable at high temperatures.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] 1. The present invention carefully designs the water removal and solvent removal process of the finished antistatic agent. The prepared antistatic agent can be used in the preparation of polyolefins, the solvent residue is within the required range, the antistatic effect is good and it is not easy to affect the catalyst, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0022] Figure 1 is a process flow chart of the polyolefin antistatic agent in Example 1; DETAILED DESCRIPTION

[0023] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0024] like Figure 1 As shown, the preparation of the 425 type finished antistatic agent on the market is as follows: First, a conductive polymer is prepared by reacting monomers, other raw materials, and an initiator, and the conductive polymer is mixed with other components to prepare a finished antistatic agent.

[0025] Our company also uses the above process route for synthesis, as follows:

[0026] Preparation of finished antistatic agent: Monomer (alpha olefin), other raw materials (sulfur dioxide, n-heptane), initiator (dimethyl azobisisobutyrate) react at a mass ratio of (4:3:0.5:2.5) at 30°C to generate conductive polymer, and the conductive polymer and polyamine compound are mixed at a predetermined ratio to obtain the finished antistatic agent. The molecular weight of polysalicylic acid in the prepared finished antistatic agent is in the range of 3000-12000, and the mass ratio of polysalicylic acid compound to polyamine compound is 0.5:1-1:1.

[0027] At the same time, the proportion of material components was adjusted so that the molecular weight of the polyamine compound in the prepared antistatic agent was in the range of 14000-20000, and the mass ratio of the polyamine compound to the polyamine compound was adjusted to 2:1 for control analysis.

[0028] like Figure 1 As shown, the prepared finished antistatic agent is placed in a reaction kettle, and under mechanical stirring, nitrogen is purged, vacuumed and heated to 80-120°C to condense the solvent in the finished antistatic agent into a liquid in a condenser. The solvent is such as benzene, toluene, xylene, etc. The residual solvent in the finished antistatic agent is detected in advance. When the solvent in the condenser reaches a predetermined weight, it means that the residual solvent in the finished antistatic agent is lower than a predetermined range, such as the solvent content is lower than 1000ppm. Then, it is dissolved in n-heptane to form a polyolefin antistatic agent stock solution, and then a dehydrating agent is added and sealed and allowed to stand to drain water. Samples are taken at intervals in the middle to detect the moisture content. When the moisture content is below 1000ppm, the polyolefin antistatic agent is a finished product. For details, see the following examples.

[0029] Example 1

[0030] The preparation process of high-purity antistatic agent comprises the following steps:

[0031] Solvent Removal Steps:

[0032] The finished antistatic agent prepared as above (polysulfone molecular weight: 6000-10000, mass ratio of polysulfone compound to polyamine compound is 0.5:1) is placed in a reaction kettle, evacuated and purged with nitrogen under mechanical stirring, and continuously heated to 85°C. The solvent in the finished antistatic agent is brought out by nitrogen and condensed into liquid in a condenser. After the solvent is brought out to the theoretical value, the heating is stopped and nitrogen is continued to be passed to cool the formed solid conductive polymer. After sampling and detection, the solvent in the solid conductive polymer in this example is as low as 800ppm.

[0033] Water removal steps:

[0034] The solid conductive polymer cooled to 35°C is dissolved in n-heptane and slowly stirred until it dissolves into a transparent liquid. A dehydrating agent is added and the mixture is allowed to stand in a closed container to remove water. The dehydrating agent is a molecular sieve. Samples are taken at intervals to detect the moisture content. Molecular sieves can be added until the moisture content is as low as 500ppm.

[0035] Example 2

[0036] The preparation process of high-purity antistatic agent comprises the following steps:

[0037] Solvent Removal Steps:

[0038] The finished antistatic agent prepared as above (polysulfone molecular weight: 3000-6000, mass ratio of polysulfone compound to polyamine compound is 0.8:1) is placed in a reaction kettle, evacuated and purged with nitrogen under mechanical stirring, and continuously heated to 100°C. The solvent in the finished antistatic agent is brought out by nitrogen and condensed into liquid in a condenser. After the solvent is brought out to the theoretical value, the heating is stopped and nitrogen is continued to be passed to cool the formed solid conductive polymer. After sampling and detection, the solvent in the solid conductive polymer in this example is as low as 600ppm.

[0039] Water removal steps:

[0040] The solid conductive polymer cooled to 30°C is dissolved in n-heptane and slowly stirred until it dissolves into a transparent liquid. A dehydrating agent is added and the mixture is allowed to stand in a closed container to remove water. The dehydrating agent is a molecular sieve. Samples are taken at intervals to detect the moisture content. Molecular sieves can be added until the moisture content is as low as 400ppm.

[0041] Example 3

[0042] The preparation process of high-purity antistatic agent comprises the following steps:

[0043] Solvent Removal Steps:

[0044] The finished antistatic agent prepared as above (polysulfone molecular weight: 8000-12000, the mass ratio of polysulfone compound to polyamine compound is 1:1) is placed in a reaction kettle, evacuated and purged with nitrogen under mechanical stirring, and continuously heated to 120°C. The solvent in the finished antistatic agent is brought out by nitrogen and condensed into liquid in a condenser. After the solvent is brought out to the theoretical value, the heating is stopped and nitrogen is continued to be passed to cool the formed solid conductive polymer. After sampling and testing, the solvent in the solid conductive polymer in this example is less than 200ppm.

[0045] Water removal steps:

[0046] The solid conductive polymer cooled to 40°C is dissolved in n-heptane and slowly stirred until it dissolves into a transparent liquid. A dehydrating agent is added and the mixture is sealed and allowed to stand to remove water. The dehydrating agent is a molecular sieve. Samples are taken at intervals to detect the moisture content. Molecular sieves can be added additionally until the moisture content is less than 200ppm.

[0047] Comparative Example 1

[0048] The difference from Example 1 is that the molecular weight of the polysulfone in this example is in the range of 16000-20000.

[0049] Comparative Example 2

[0050] The difference from Example 1 is that in this example, the molecular weight of the polysulfone is in the range of 16000-20000, and the heating temperature in the solvent removal step is 160°C.

[0051] Comparative Example 3

[0052] The difference from Example 1 is that in this example, the molecular weight of polysulfone is in the range of 16000-20000, the mass ratio of polysulfone compound to polyamine compound is 2:1, and the heating temperature in the solvent step is 160°C.

[0053] The antistatic effect of the finished polyolefin antistatic agent prepared in the above examples and comparative examples was tested. 2 mg of the finished polyolefin antistatic agent was added to 1000 ml of ISOPARM ISOPAR M isoparaffin solvent oil, and its conductivity was tested at 20° C., as shown in the following table:

[0054] Table 1

[0055]

[0056]

[0057] The molecular weight of the polysulfone in Comparative Example 1 is too large, and the solvent content cannot meet the standard at the heating temperature of Example 1, and cannot meet the reaction requirements of polyolefins.

[0058] In Comparative Example 2, the temperature of solvent removal was increased, and the solvent content reached the standard, but the antistatic effect was attenuated.

[0059] In Comparative Example 3, the molecular weight of polysulfone was changed, the mass ratio of polysulfone compound to polyamine compound was changed, and the solvent removal temperature was changed, and the antistatic effect was greatly attenuated.

[0060] The above are only preferred embodiments of the present invention. The protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A process for preparing a high-purity antistatic agent, characterized in that: The following steps are involved: Solvent Removal Steps: The molecular weight of the polysulfone of the finished antistatic agent is 3000-12000. The solvent in the finished antistatic agent is removed by heating, vacuuming, purging with inert gas and stirring to form a solid conductive polymer. Water removal steps: The cooled solid conductive polymer is dissolved in n-heptane, and a dehydrating agent is added to perform closed dehydration.

2. The preparation process of the high-purity antistatic agent according to claim 1, characterized in that: In the solvent removal step: the finished antistatic agent is heated to 80-120°C while stirring under inert gas. After the solvent content reaches the standard, the heating is stopped and the solid conductive polymer is cooled to 30-45°C under inert gas.

3. The preparation process of the high-purity antistatic agent according to claim 1, characterized in that: In the water removal step: molecular sieve is used as the water removal agent.

4. The preparation process of the high-purity antistatic agent as claimed in claim 3, characterized in that: During the closed water removal process, samples are taken at intervals for testing until the moisture content is below 1000ppm.

5. The preparation process of the high-purity antistatic agent according to claim 1, characterized in that: The finished antistatic agent is type 425.

6. The preparation process of the high-purity antistatic agent according to claim 1, characterized in that: Preparation of finished antistatic agent: Monomer (alpha olefin), sulfur dioxide, n-heptane, initiator (dimethyl azobisisobutyrate) react at a mass ratio of 3-5:2-4:0.4-0.6:2-3 at 25-35°C to generate conductive polymer, and the conductive polymer is mixed with polyamine compound to obtain the finished antistatic agent.

7. The preparation process of the high-purity antistatic agent according to claim 1, characterized in that: The mass ratio of the polyamine compound to the polyamine compound in the finished antistatic agent is 0.5:1-1:1.

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