CN112023429A - Method for removing low molecules of low-viscosity silicone oil - Google Patents
Method for removing low molecules of low-viscosity silicone oil Download PDFInfo
- Publication number
- CN112023429A CN112023429A CN202010801634.2A CN202010801634A CN112023429A CN 112023429 A CN112023429 A CN 112023429A CN 202010801634 A CN202010801634 A CN 202010801634A CN 112023429 A CN112023429 A CN 112023429A
- Authority
- CN
- China
- Prior art keywords
- low
- silicone oil
- heating surface
- molecules
- liquid film
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D3/00—Distillation or related exchange processes in which liquids are contacted with gaseous media, e.g. stripping
- B01D3/008—Liquid distribution
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D3/00—Distillation or related exchange processes in which liquids are contacted with gaseous media, e.g. stripping
- B01D3/12—Molecular distillation
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D5/00—Condensation of vapours; Recovering volatile solvents by condensation
- B01D5/0003—Condensation of vapours; Recovering volatile solvents by condensation by using heat-exchange surfaces for indirect contact between gases or vapours and the cooling medium
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D5/00—Condensation of vapours; Recovering volatile solvents by condensation
- B01D5/0057—Condensation of vapours; Recovering volatile solvents by condensation in combination with other processes
- B01D5/006—Condensation of vapours; Recovering volatile solvents by condensation in combination with other processes with evaporation or distillation
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G77/00—Macromolecular compounds obtained by reactions forming a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon in the main chain of the macromolecule
- C08G77/04—Polysiloxanes
- C08G77/32—Post-polymerisation treatment
- C08G77/34—Purification
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/50—Improvements relating to the production of bulk chemicals
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Health & Medical Sciences (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Silicon Polymers (AREA)
- Vaporization, Distillation, Condensation, Sublimation, And Cold Traps (AREA)
Abstract
The invention relates to the technical field of silicone oil low removal, and aims at solving the problems that in the prior art, the effect of silicone oil low removal molecules is incomplete and high-requirement application cannot be met, and discloses a method for removing low molecules of low-viscosity silicone oil, wherein a heating part in a low removal device system is close to a condensation part by utilizing the molecular distillation principle, the silicone oil flows into a heating area from a hopper, a very thin liquid film is formed under the specific action and flows downwards, low-boiling component molecules in the silicone oil can escape from the liquid surface after being heated under the action of high vacuum, the escaped low-boiling component molecules contact the condensation surface without collision and are condensed into liquid to be collected, residual molecules, namely heavy molecules, can flow downwards along the heating surface, a silicone oil finished product after low removal is obtained after collection, and the volatile components of the silicone oil can be removed to below 1 percent or even lower, moreover, the required heating temperature is reduced, and the silicone oil avoids generating pungent smell.
Description
Technical Field
The invention relates to the technical field of silicone oil low removal, in particular to a method for removing bottom molecules of low-viscosity silicone oil.
Background
The removal of low molecular weight silicone oil is a process of separating volatile components having a lower boiling point, i.e., light components, such as cyclic bodies and some short-chain linear bodies, in silicone oil from the silicone oil. The more raw material components of the silicone oil, the more complicated the low-molecular removal operation. The process of removing low molecules directly influences the volatile components and the flash point of the silicone oil, and has a vital influence on the quality of the silicone oil. In order to achieve as low a volatile content as possible, the molecular weight reduction of silicone oils is often carried out at relatively high temperatures, and in the production of silicone oils, the energy consumption of the molecular weight reduction process is more than half of the total production process.
The traditional method for removing low molecules from silicone oil mostly adopts an intermittent method: after the raw material ring body and the end capping agent are subjected to ring-opening polymerization under the action of a catalyst to generate silicone oil, the temperature is raised to a higher temperature under the vacuum condition, and low molecules are directly removed from the reaction kettle, and the method has the following defects: long time for removing low, low efficiency, high energy consumption and large fluctuation of volatile components among product batches.
The traditional intermittent low-molecular-weight removal method belongs to a common vacuum distillation process in principle, the low-boiling-point components in the materials can be gasified and separated only by bubbling boiling the materials, and the materials are often heated to a higher temperature to realize lower volatile components, for example, the low-molecular-weight removal temperature of methyl silicone oil needs to reach 220 ℃, and the low-molecular-weight removal temperature of vinyl silicone oil needs to reach 175 ℃. For example, Chinese patent 201711139884.9 discloses a method for removing methyl silicone oil with a viscosity of 30-1000000 cs, wherein low molecules are removed at a high temperature of about 220 ℃ by using a low molecule remover. However, methyl groups on the silicone oil chain are easily oxidized into formaldehyde at high temperature and remain in the finished silicone oil product, so that the finished silicone oil product is easily provided with irritant formaldehyde odor. And because the common distillation is a reversible process of evaporation and condensation, a phase equilibrium state can be formed between a liquid phase and a gas phase, so that low-boiling components in the silicone oil cannot be thoroughly and cleanly removed, and volatile components cannot reach a very low level.
Disclosure of Invention
Aiming at the problems that the effect of removing bottom molecules of silicone oil is not thorough and the application with high requirements cannot be met in the prior art, the invention aims to provide a method for removing low molecules of low-viscosity silicone oil, so that the low molecules in the silicone oil can be removed efficiently, and the temperature required in the process of removing the low molecules is reduced.
The technical scheme provided by the invention is as follows:
a method for removing low molecules of low-viscosity silicone oil comprises the steps of feeding the low-viscosity silicone oil into a removing device with a high vacuum environment, wherein a heating surface and a condensing surface opposite to the heating surface are arranged in the removing device, a film forming structure capable of enabling the low-viscosity silicone oil to form a liquid film on the heating surface is arranged, the low-viscosity silicone oil forms the liquid film under the action of the film forming structure and flows from top to bottom on the heating surface, light components in the liquid film escape after being heated, the light components are condensed and flow out after contacting the condensing surface to obtain low molecules, and heavy components in the liquid film flow out along the heating surface to be collected to obtain a low-viscosity silicone oil finished product.
The method adopts a low-removing device with a heating surface and a condensing surface which are arranged oppositely, the silicon oil flows into a heating area from a feeding hopper, a thin liquid film is formed under the specific action of a film-forming structure, such as the action of centrifugation or a scraper, and flows downwards, because the average free path of movement of light components and heavy components is different, the light component molecules with low boiling point in the heated silicon oil can firstly escape from the liquid surface under the action of high vacuum, because the condensing surface is very close to the heating surface, the escaped light component molecules are condensed into liquid on the condensing surface without collision, the residual liquid, namely heavy molecules, can flow downwards along the heating surface, and the low-removed silicon oil finished product can be obtained after the residual liquid, namely the heavy molecules, are collected. Thus, the volatile components can be removed to be below 1 percent, and the removal temperature is lower.
As a preference of the process of the invention, the demould apparatus is a rotary scraper evaporator, a centrifugal rotary evaporator or a falling-film evaporator using the principle of molecular distillation.
As a preference of the method of the invention, when a falling film evaporator is used, the surface of the heating surface is provided with a plurality of obliquely downward stripes to distribute the low-viscosity silicone oil to form a uniform liquid film.
Preferably, in the method of the present invention, the distance between the heating surface and the condensing surface is 10 to 30 mm.
Preferably, the pressure of the high vacuum environment is less than or equal to 1.33 Pa.
Preferably, the heating temperature is 120-180 ℃.
In the method of the present invention, the thickness of the liquid film formed on the heating surface by the silicone oil is preferably 0.05 to 0.1 mm.
Preferably, the heating surface is gradually inclined towards the condensing surface from top to bottom along the flowing direction of the liquid film, and the inclination angle is more than or equal to 85 degrees. Because the liquid film has a certain thickness, part of the low molecules in the liquid film are not fully escaped in the flowing process, namely, are wrapped and carried out of the low-molecular separator, and the effective separation can not be realized. Therefore, the inventor sets the heating surface to be gradually inclined towards the condensation surface from top to bottom in the process of process improvement to form a slope, and the inclined arrangement effectively slows down the downward flowing speed of the liquid film and prolongs the flowing time of the liquid film because the liquid film flows downwards by the gravity, so that light components in the liquid film can escape more sufficiently, and the low-molecular removal effect is improved. However, the angle of inclination must be reasonably controlled because too small an angle of inclination will prevent the liquid film from flowing downward and the flow rate will be too slow, which will both impair the removal efficiency and result in the loss of part of the heavy fraction, so reasonable angles of inclination are angles of inclination of > 85 °. More preferably, the angle is 87 to 89 degrees. It is understood that when a rotary blade evaporator is used, the shape of the blades can be changed accordingly, such as wider at the top and narrower at the bottom, to match the heating surface, which is a conventional adjustment and not described herein.
Preferably, the surface of the heating surface is provided with a plurality of small holes with the aperture of 200-300 microns, the heating surface is internally provided with a plurality of inert gas channels communicated with the small holes, the inert gas channels are distributed at intervals at the end part of the heating surface and extend along the height direction of the heating surface, and the flow rate of inert gas in the inert gas channels is 0.2-0.3 mL/min.
Preferably, in the method of the present invention, the temperature of the inert gas is equal to or higher than the temperature of the liquid film. The inert gas can form bubbles at the small holes in the flowing process, so that the turbulent flow state in the liquid film is promoted, and the heat transfer and mass transfer are enhanced. However, since the pore diameter of the pores is small and the silicone oil has viscosity, there is no fear that the silicone oil leaks from the pores. When the reaction is finished, the silicone oil is stopped from being added for a period of time, and then the ventilation is stopped. In the aeration process, the inert gas is heated to the temperature of the heating surface or higher than the temperature of the heating surface, preferably 5-10 ℃ higher than the temperature of the liquid film, so as to promote the light components in the liquid film to move outwards.
The invention has the following beneficial effects:
compared with the traditional batch reaction kettle, the method for removing low molecules of silicone oil adopts the principle of molecular distillation, distributes materials into thin liquid films in a rotary scraper evaporator or a centrifugal rotary evaporator and a falling film evaporator, and heats the materials more quickly and uniformly, thereby greatly improving the removal efficiency; because the different moving mean free paths of different substance molecules are used for separation, rather than separation according to the boiling point difference, the materials are not required to reach the bubbling boiling state, the temperature required in the process of removing the low-temperature substances is lower, the condition that methyl on the silicone oil is oxidized and converted into formaldehyde is reduced, the peculiar smell of the silicone oil product can be reduced to a great extent, and the energy consumption is saved to a great extent; the heating part of the low-boiling component removing system is close to the condensing part, and low-boiling component molecules can directly touch the condenser to be changed into liquid after escaping and cannot flow back into the silicone oil, so that the process is irreversible, and the volatile component of the finished silicone oil can be reduced to be very low.
Drawings
FIG. 1 is a view showing a structure in which a heating surface is inclined from the top to the bottom toward a condensation surface in example 6.
FIG. 2 is a longitudinal sectional view of the heating surface in example 9.
Fig. 3 is an enlarged view at a in fig. 2.
In the figure, 1, a heating surface, 11, a liquid film, 12, small holes, 13, an inert gas channel, 2 and a condensing surface;
the arrow a indicates the liquid film flow direction and the arrow b indicates the nitrogen flow direction.
Detailed Description
The invention is further illustrated by the following examples, but the scope of the invention as claimed is not limited to the examples.
The inert gases used in the following examples or comparative examples are illustrated by way of nitrogen.
The light components and volatile components expressed in the present invention are low molecules in the silicone oil.
Example 1
A method for removing low molecules of low-viscosity silicone oil adopts a falling film evaporator as a removing device, and comprises the following processes: adding polymerized dimethyl silicone oil semi-finished product (light component content 9.2 +/-0.05%) into a receiving hopper at the top of a falling-film evaporator, controlling a feeding valve to enable the material to slowly flow into a heating device, controlling the temperature of a heating system to be 180 ℃, controlling the distance between a condensing surface and a heating surface of the falling-film evaporator to be 10mm, controlling the pressure of a vacuum environment in the whole device to be 0.8Pa, arranging inclined thread-shaped stripes on the surface of the heating surface, distributing the silicone oil on the heating surface from the top of the falling-film evaporator, forming a liquid film with the thickness of 0.05mm downwards along the stripes of the heating surface to flow, enabling the light component in the liquid film to escape after being heated, condensing and flowing out after contacting the condensing surface, collecting low molecules from the bottom of a condensing system of a de-condensation device, enabling the heavy component in the liquid film to flow out along the heating surface, collecting the low-viscosity silicone oil finished product from the bottom of a heating system of the, the content of volatile components in the finished low-viscosity silicone oil is measured to be 0.2 percent.
Example 2
A method for removing low molecules of low-viscosity silicone oil adopts a falling film evaporator as a removing device, and comprises the following processes: adding polymerized dimethyl silicone oil semi-finished product (light component content 9.2 +/-0.05%) into a receiving hopper at the top of a falling-film evaporator, controlling a feeding valve to enable the material to slowly flow into a heating device, controlling the temperature of a heating system to be 170 ℃, controlling the distance between a condensing surface and a heating surface of the falling-film evaporator to be 20mm, controlling the pressure of a vacuum environment in the whole device to be 0.8Pa, arranging inclined thread-shaped stripes on the surface of the heating surface, distributing the silicone oil on the heating surface from the top of the falling-film evaporator, forming a liquid film with the thickness of 0.08mm downwards along the stripes of the heating surface to flow, enabling the light component in the liquid film to escape after being heated, condensing and flowing out after contacting the condensing surface, collecting low molecules from the bottom of a condensing system of a de-condensation device, enabling the heavy component in the liquid film to flow out along the heating surface, collecting the low-viscosity silicone oil finished product from the bottom of a heating system of the, the content of volatile components in the finished low-viscosity silicone oil is measured to be 0.6 percent.
Example 3
A method for removing low molecules of low-viscosity silicone oil adopts a falling film evaporator as a removing device, and comprises the following processes: adding polymerized dimethyl silicone oil semi-finished product (light component content 9.2 +/-0.05%) into a receiving hopper at the top of a falling-film evaporator, controlling a feeding valve to enable the material to slowly flow into a heating device, controlling the temperature of the heating system to be 120 ℃, controlling the distance between a condensing surface and a heating surface of the falling-film evaporator to be 30mm, controlling the pressure of a vacuum environment in the whole device to be 1.0Pa, arranging obliquely downward thread-shaped stripes on the surface of the heating surface, distributing the silicone oil on the heating surface from the top of the falling-film evaporator, forming a liquid film with the thickness of 0.1mm downwards along the stripes of the heating surface to flow, enabling the light component in the liquid film to escape after being heated, condensing and flowing out after contacting the condensing surface, collecting low molecules from the bottom of a condensing system of a de-condensation device, enabling the heavy component in the liquid film to flow out along the heating surface, collecting the low-viscosity silicone oil finished product from the bottom of a heating system of, the content of volatile components in the finished low-viscosity silicone oil is measured to be 0.7 percent.
Example 4
A method for removing low molecules of low-viscosity silicone oil adopts a falling film evaporator as a removing device, and comprises the following processes: adding a polymerized semi-finished product of the vinyl-terminated silicone oil (the content of light components is 8.7 +/-0.04%) into a receiving hopper at the top of a falling-film evaporator, controlling a feeding valve to enable the material to slowly flow into a heating device, controlling the temperature of a heating system to be 140 ℃, controlling the distance between a condensing surface and a heating surface of the falling-film evaporator to be 15mm, controlling the pressure of a vacuum environment in the whole device to be 1.2Pa, arranging obliquely downward thread-shaped stripes on the surface of the heating surface, distributing the silicone oil on the heating surface from the top of the falling-film evaporator, forming a liquid film with the thickness of 0.06mm downwards along the stripes of the heating surface to flow, enabling the light components in the liquid film to escape after being heated, condensing and flowing out after contacting the condensing surface, collecting low molecules from the bottom of a condensing system of a de-reduction device, enabling heavy components in the liquid film to flow out along the heating surface, collecting a low-viscosity silicone oil, has no pungent smell, and the content of volatile components in the finished product of the low-viscosity silicone oil is measured to be 0.5 percent.
Example 5
A method for removing low molecules of low-viscosity silicone oil, wherein a used removing device is a rotary scraper evaporator, and the method comprises the following steps: adding a polymerized semi-finished dimethyl silicone oil (the content of light components is 9.2 +/-0.05%) into a receiving hopper at the top of a rotary scraper evaporator, controlling a feeding valve to enable the material to slowly flow into a heating device, controlling the temperature of a heating system to be 180 ℃, controlling the distance between a condensing surface and a heating surface of the rotary scraper evaporator to be 10mm, controlling the pressure of a vacuum environment in the whole device to be 0.8Pa, scraping the silicone oil into a thin film by a scraper of the rotary scraper evaporator, wherein the thickness of the liquid film is 0.05mm, the light components in the liquid film escape after being heated and condense and flow out after contacting the condensing surface, collecting low molecules from the bottom of a condensing system of a reduction device, flowing heavy components in the liquid film along the heating surface, collecting a low-viscosity silicone oil finished product from the bottom of a heating system of the reduction device, and measuring the content of volatile components in the low-viscosity silicone oil to be 0.3%.
Comparative example 1
And (3) placing the semi-finished product of the polymerized dimethyl silicone oil into a flask for vacuum reduction, controlling the oil temperature of an oil bath kettle to be 220 ℃, controlling the pressure in the flask to be 1.2Pa, and reducing for 3h, and after the reduction of molecules is finished, determining that the volatility of the silicone oil product is 1% and the finished product of the silicone oil has pungent smell.
Example 6
A method for removing low molecular weight from low viscosity silicone oil, the used removing device is a rotary scraper evaporator, and the difference from the embodiment 5 is that, as shown in figure 1, a heating surface 1 of the rotary scraper evaporator is gradually inclined towards a condensation surface 2 from top to bottom, the inclination angle is 85 degrees, and a liquid film 11 flows from top to bottom as indicated by an arrow a. And measuring the finished low-viscosity silicone oil without pungent smell after the low-molecular removal is finished, wherein the mass content of the volatile components is 0.188%.
Example 7
A method for removing low molecules of low-viscosity silicone oil uses a rotary scraper evaporator, and is different from the embodiment 5 in that a heating surface of the rotary scraper evaporator is gradually inclined towards a condensation surface from top to bottom, and the inclination angle is 87 degrees. And measuring that the low-viscosity silicone oil finished product has no pungent smell after the low-molecular removal is finished, wherein the mass content of the volatile components is 0.172 percent.
Example 8
A method for removing low molecules of low-viscosity silicone oil uses a rotary scraper evaporator, and is different from the embodiment 5 in that a heating surface of the rotary scraper evaporator gradually inclines towards a condensation surface from top to bottom, and the inclination angle is 89 degrees. And measuring that the finished low-viscosity silicone oil product has no pungent smell after the low-molecular removal is finished, wherein the mass content of the volatile component is 0.179 percent.
Comparative example 2
Compared with example 6, the heating surface of the rotary blade evaporator was inclined from the top to the bottom gradually toward the condensation surface at an angle of 82 °. And measuring that the low-viscosity silicone oil finished product has no pungent smell after the low-molecular removal is finished, wherein the mass content of volatile components is 0.186%, the processing time is increased by 60%, and the loss of the low-viscosity silicone oil finished product is 12%.
From the above comparison, it is understood that the smaller inclination angle can achieve a lower low molecular weight level, but the processing time increases and the loss of heavy components increases, so that the inclination angle should not be set lower than 85 ° in general.
Example 9
A method for removing low molecules of low-viscosity silicone oil uses a rotary scraper evaporator, and is different from the embodiment 5 in that, as shown in figures 2 and 3, the surface of a heating surface 1 of the rotary scraper evaporator is provided with small holes 12 with the diameter of 200 microns and the depth of the holes is about 1mm, an inert gas channel 13 communicated with the small holes is arranged in the heating surface, the inert gas channel is distributed at intervals at the end part of the heating surface and extends along the height (or the longitudinal direction, or the up-and-down flowing direction of a liquid film) of the heating surface, nitrogen in the inert gas channel flows in a counter-flow manner from bottom to top along an arrow b, the flow rate is 0.2mL/min, and the temperature of the inert gas is 180 ℃. And measuring that the finished low-viscosity silicone oil product has no pungent smell after the low-molecular removal is finished, wherein the mass content of the volatile components is 0.182%.
Example 10
A method for removing low molecules of low-viscosity silicone oil is different from the method in example 9 in that: the surface of the heating surface of the rotary scraper evaporator is provided with small holes with the aperture of 300 microns, the hole depth is about 1mm, the nitrogen flow rate in the inert gas channel is 0.3mL/min, and the temperature of the nitrogen is 180 ℃. And measuring that the low-viscosity silicone oil finished product has no pungent smell after the low-molecular removal is finished, wherein the mass content of the volatile components is 0.184 percent.
Example 11
A method for removing low molecules of low-viscosity silicone oil is different from the method in example 9 in that: the surface of the heating surface of the rotary scraper evaporator is provided with small holes with the aperture of 300 microns, the hole depth is about 1mm, the nitrogen flow rate in the inert gas channel is 0.3mL/min, and the temperature of the nitrogen is 185 ℃. And measuring the finished low-viscosity silicone oil product without pungent odor after the low molecule removal is finished, wherein the mass content of the volatile components is 0.173%.
Comparative example 3
The difference from example 9 is that the temperature of the inert gas was 170 ℃. And measuring the finished low-viscosity silicone oil without pungent smell after the low-molecular removal is finished, wherein the mass content of the volatile component is 0.26%.
Example 12
A method for removing low molecules of low-viscosity silicone oil uses a rotary scraper evaporator, and is different from the embodiment 5 in that a heating surface of the rotary scraper evaporator gradually inclines to a condensation surface from top to bottom, and the inclination angle is 86 degrees; the surface of the heating surface is provided with small holes with the aperture of 300 microns, the depth of each hole is about 1mm, an inert gas channel communicated with the small holes is arranged in the heating surface, the inert gas channels are distributed at intervals at the end part of the heating surface and extend along the height of the heating surface, nitrogen in the inert gas channel flows reversely from bottom to top along the direction of an arrow b, the flow speed is 0.3mL/min, the temperature of the nitrogen is 185 ℃, after low molecular removal, the non-irritating odor of the low-viscosity silicone oil finished product is measured, and the mass content of volatile components is 0.162%.
The problem that the silicone oil obtained by removing the low molecules in the above embodiments has no peculiar smell exists, and the volatile components can reach a lower level, which is obviously improved compared with the silicone oil obtained by adopting the traditional low molecule removing method.
Claims (10)
1. A method for removing low molecules of low-viscosity silicone oil is characterized in that the low-viscosity silicone oil is fed into a removing device with a high vacuum environment, a heating surface and a condensing surface opposite to the heating surface are arranged in the removing device, a film forming structure capable of enabling the low-viscosity silicone oil to form a liquid film on the heating surface is arranged, the low-viscosity silicone oil forms a liquid film under the action of the film forming structure and flows from top to bottom on the heating surface, light components in the liquid film escape after being heated and are condensed and flow out after contacting the condensing surface to obtain low molecules, and heavy components in the liquid film flow out along the heating surface to obtain a low-viscosity silicone oil finished product.
2. The method for removing low molecules of low viscosity silicone oil according to claim 1, wherein the removal device is a rotary scraper evaporator, a centrifugal rotary evaporator or a falling film evaporator using the principle of molecular distillation.
3. The method as claimed in claim 2, wherein the surface of the heating surface is provided with a plurality of obliquely downward stripes to distribute the low viscosity silicone oil into a uniform liquid film when the falling film evaporator is used.
4. The method for removing low-viscosity silicone oil from low-molecular weight according to any one of claims 1 to 3, wherein the distance between the heating surface and the condensation surface is 10 to 30 mm.
5. The method for removing low molecular weight silicone oil with low viscosity as claimed in any one of claims 1 to 3, wherein the pressure of said high vacuum environment is less than or equal to 1.33 Pa.
6. The method for removing low molecular weight silicone oil with low viscosity as claimed in any one of claims 1 to 3, wherein the heating temperature is 120 to 180 ℃.
7. The method for removing low molecular weight silicone oil of claim 1 to 3, wherein the silicone oil forms a liquid film on the heating surface with a thickness of 0.05 to 0.1 mm.
8. The method for removing low molecules from low viscosity silicone oil according to any one of claims 1 to 3, wherein the heating surface is gradually inclined from top to bottom in the liquid film flowing direction toward the condensation surface at an angle of not less than 85 °.
9. The method for removing low molecules of low viscosity silicone oil according to any one of claims 1 to 3, wherein the surface of the heating surface is provided with a plurality of pores with a diameter of 200 to 300 μm, the heating surface is provided with a plurality of inert gas channels communicated with the pores, the inert gas channels are distributed at intervals at the end of the heating surface and extend along the height direction of the heating surface, and the flow rate of the inert gas in the inert gas channels is 0.2 to 0.3 mL/min.
10. The method for removing low molecules of a low viscosity silicone oil according to claim 9, wherein the temperature of the inert gas is equal to or higher than the temperature of the liquid film.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010801634.2A CN112023429B (en) | 2020-08-11 | 2020-08-11 | Method for removing low molecules of low-viscosity silicone oil |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010801634.2A CN112023429B (en) | 2020-08-11 | 2020-08-11 | Method for removing low molecules of low-viscosity silicone oil |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN112023429A true CN112023429A (en) | 2020-12-04 |
| CN112023429B CN112023429B (en) | 2022-04-26 |
Family
ID=73577317
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010801634.2A Active CN112023429B (en) | 2020-08-11 | 2020-08-11 | Method for removing low molecules of low-viscosity silicone oil |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112023429B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113698605A (en) * | 2021-09-27 | 2021-11-26 | 矽时代材料科技股份有限公司 | Preparation method of high-purity polysiloxane |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102120094A (en) * | 2011-01-17 | 2011-07-13 | 上海康宁医疗用品有限公司 | Method for removing small molecules from silicone gel by molecular distillation |
| CN205549627U (en) * | 2016-04-18 | 2016-09-07 | 温州市四方制药设备成套有限公司 | Wiped film evaporator's evaporative cylinder |
| CN107774001A (en) * | 2016-08-29 | 2018-03-09 | 中国石油化工股份有限公司 | A kind of vertical tube falling evaporator |
| CN109821264A (en) * | 2019-03-22 | 2019-05-31 | 中国人民解放军国防科技大学 | Method and device for evaporating and removing low content of polycarbosilane melt |
| US20200147516A1 (en) * | 2018-11-09 | 2020-05-14 | Delta Team Holdings, LLC | Extraction system |
-
2020
- 2020-08-11 CN CN202010801634.2A patent/CN112023429B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102120094A (en) * | 2011-01-17 | 2011-07-13 | 上海康宁医疗用品有限公司 | Method for removing small molecules from silicone gel by molecular distillation |
| CN205549627U (en) * | 2016-04-18 | 2016-09-07 | 温州市四方制药设备成套有限公司 | Wiped film evaporator's evaporative cylinder |
| CN107774001A (en) * | 2016-08-29 | 2018-03-09 | 中国石油化工股份有限公司 | A kind of vertical tube falling evaporator |
| US20200147516A1 (en) * | 2018-11-09 | 2020-05-14 | Delta Team Holdings, LLC | Extraction system |
| CN109821264A (en) * | 2019-03-22 | 2019-05-31 | 中国人民解放军国防科技大学 | Method and device for evaporating and removing low content of polycarbosilane melt |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113698605A (en) * | 2021-09-27 | 2021-11-26 | 矽时代材料科技股份有限公司 | Preparation method of high-purity polysiloxane |
Also Published As
| Publication number | Publication date |
|---|---|
| CN112023429B (en) | 2022-04-26 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN112023429B (en) | Method for removing low molecules of low-viscosity silicone oil | |
| CN101696203B (en) | Method for continuously refining L-lactide from crude L-lactide | |
| CN108102100B (en) | Production method and production system of low-volatility vinyl silicone oil | |
| CN103113339B (en) | Maltol separation and purification method | |
| EP3348318B1 (en) | Evaporator | |
| KR20150124944A (en) | A devolatilisation apparatus and a process for use thereof | |
| CN1083458C (en) | Method for removing volatile substances from polymer composition | |
| JP2001010981A (en) | Method for reacting mixture solution | |
| JP7203092B2 (en) | Method for deodorizing hydrogenated petroleum resin and method for producing hydrogenated petroleum resin | |
| CN112125986A (en) | Styrene-butadiene latex demonomerization and concentration device and process | |
| CN209957681U (en) | Polylactic acid devolatilization device | |
| CN111574709A (en) | Multistage devolatilization device for nylon 6 melt | |
| US3252502A (en) | Centrifugal wiped film evaporation process for viscous materials | |
| US11241637B2 (en) | Device for the thermal treatment of material, in particular for the thermal separation of material components contained in the material | |
| CN111333834B (en) | Devolatilization method of nylon 6 melt | |
| SE459498B (en) | PROCEDURE TO PROCESS REMAIN PRODUCT AFTER VACUUM DISTILLATION IN A RAW OIL AFFINERY | |
| CN203564805U (en) | Molecular distilling equipment for 3-BPC (3-bromine-N-phenyl carbazole) production | |
| Bethge | Short path and molecular distillation | |
| CN203677976U (en) | Microwave wiped film molecular distilling device with film evaporator function | |
| RU2668870C1 (en) | Method of obtaining anisotropic petroleum pitch | |
| CN104056463A (en) | Distributor and distillation device with same | |
| CN202620747U (en) | Removal device of low molecular substance in adhesive | |
| EP0095792B1 (en) | Process for separating a multi-component liquid | |
| CN203874491U (en) | Distributor and distillation apparatus comprising same | |
| KR101326877B1 (en) | Apparatus of manufacturing pitch and method for preparing pitch using the same |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| CB02 | Change of applicant information | ||
| CB02 | Change of applicant information |
Address after: 324000 No. 20 Huayin North Road, Quzhou City, Zhejiang Province, China Applicant after: Zhejiang Zhongtian Dongfang fluorosilicone Material Co.,Ltd. Address before: 324000 No. 20 Huayin North Road, Quzhou City, Zhejiang Province, China Applicant before: ZHONGTIAN DONGFANG FLUORINE SILICON MATERIAL Co.,Ltd. |
|
| GR01 | Patent grant | ||
| GR01 | Patent grant |