KR930009082B1 - Continuous treatment process for particulate meterial - Google Patents

Abstract

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Description

Continuous processing method

1 is a schematic diagram of an embodiment of the present invention.

＊ Explanation of symbols on main parts of drawing

10: processing object storage container 20: processing agent storage container,

12, 22: pump 14, 24: pipe,

26: injection means 30: collection container.

The present invention relates to a process for treating materials having a bulk density of about 160.2 Kg / m ³ (10 lb / ft ³ ) or less in a continuous manner with a treatment agent. More specifically, the present invention is directed to contacting a treatment agent during transfer to a container in a dense phase with a bulk density of about 160.2 Kg / m ³ or less, and heating the material in contact with the treatment agent as necessary. It relates to a method characterized by.

Materials having a bulk density of about 160.2 Kg / m ³ or less are commonly used as fillers or reinforcing agents to improve the physical properties of compositions such as rubbers, creting agents, adhesives, paints and sealants. Examples of such materials include, but are not limited to, fumed silica, precipitated silica, fumed alumina, carbon black and aerogels.

These materials having a bulk density of about 160.2 Kg / m ³ or less often need to be treated to change their physical properties to have properties suitable for the purpose of the measurement. Generally known processing agents include, but are not limited to, liquids, vapors, spray liquids, granular solids and the like. Generally, materials having a bulk density of about 160.2 Kg / m ³ or less are treated at a ratio of about 1-5 weight percent of the material relative to 1 part by weight of the treatment agent.

For example, hydrophobic fillers or reinforcing agents are often required. Therefore, if the material having a bulk density of about 160.2 Kg / m ³ or less is hydrophilic in the normal state, it must be treated to be hydrophobic. As mentioned above, materials that are generally hydrophilic and have a bulk density of about 160.2 Kg / m ³ or less are treated with a treatment to make them hydrophobic. Examples of such a treatment agent include, but are not limited to, silicone oil, silane oil, dimethylsiloxane oil, and hydrogen fluoride vapor.

Generally, about 1-5 parts by weight of material having a bulk density of about 160.2 Kg / m ³ or less can be treated with 1 part by weight of treatment agent. For example, in an embodiment of the present invention for treating fumed silica with silane oil, about 2-5 parts by weight of fumed silica is treated with 1 part by weight of silane oil.

As discussed previously, one example of a material having a bulk density of about 160.2 Kg / m ³ or less is fumed silica. This material, also known as pyrogenic silica, is a known reinforcing agent or filler commonly used to improve the properties of compositions such as silicone rubbers, coatings, adhesives and sealants. Fumed silica consists essentially of finely divided silicon dioxide particles, having a bulk density of about 80.1 Kg / m ³ (5 lb / ft ³ ) or less, and a surface area of about 50-400 m ² / g.

Another example of a material having a bulk density of about 160.2 Kg / m ³ or less is precipitated silica. Precipitated silicas are also well known as reinforcing agents or fillers commonly used to improve the properties of compositions such as silicone rubbers, coatings, adhesives and sealants. Precipitated silica consists essentially of finely divided silicon dioxide particles and has a bulk density of generally about 160.2 Kg / m ³ or less. For certain applications it is necessary to use hydrophobic fumed silica. In general, hydrophilic fumed silica is made hydrophobic by treating hydrophilic fumed silica with a treating agent. For example, Ettlinger et al. Treated fumed silica with an organosilicon compound, such as silicone oil, to make the fumed silica hydrophobic in US Pat. No. 4,037,023 and fumed in Calvin's US Pat. No. 4,054,689. The fumed silica has been described as being treated with hydrogen fluoride vapor to render the silica hydrophobic. In some cases, heating may be required to accelerate the reaction between the fumed silica and the treating agent.

Generally, fumed silica is treated by a batch method in a container in which the fumed silica is filled into a container, and then the fumed silica is contacted with a treating agent. This method is described in US Pat. No. 4,307,023. Mechanical mixing means may also be used to mix the fumed silica with the treating agent. The vessel may also be heated during processing. A similar method is described in Razzano, U.S. Patent No. 4,780,108, which comprises placing a material of low bulk density into a mixing vessel and then spraying the treatment on the material while mixing vigorously. Another batch method is described in US Pat. No. 4,054,689, in which a treatment agent can be added to the vessel before fumed silica.

However, there are a number of drawbacks to this method of treating a material having a bulk density of about 160.2 Kg / m ³ or less with the treating agent by contacting the treating agent in a container. First, these methods are discontinuous. Both must be added to the container in a fixed amount in order to maintain a predetermined proportion of materials and treatments having a bulk density of about 160.2 Kg / m ³ or less. The final product must then be completely removed from the container and the container cleaned. Subsequently, the process is restarted with fresh amounts of material and treatment agent having a bulk density of about 160.2 Kg / m ³ or less.

Another drawback with commonly used methods is that the means for adding the treatment to the container is frequently blocked. For example, the treatment agent is generally added to the vessel via injection means (nozzles) or other openings at the ends of the tube (s). Since this injection means or openings are blocked by materials having a bulk density of about 160.2 Kg / m ³ or less, they should be cleaned frequently.

In addition, given the fact that generally known methods are batch processes, the treatment agent aggregates into balls in the container and collects on the injection means or openings. Therefore, in order to remove the ball-shaped treatment agent, it is necessary to clean all the injection means, the opening and the container, and collect the treatment agent.

In addition, when heating a container, the processing agent gathered in a ball-shaped processing agent and / or a nozzle or opening part becomes a cause of fire in a container. This ignition can also occur if the excess treatment agent in the container is not completely cleaned.

Another problem with the method of treating a material having a bulk density of about 160.2 Kg / m ³ or less by contacting the treatment agent in a container is that all the materials must be in contact with the treatment agent. As discussed previously, mechanical mixing means are often employed to ensure that all materials having a bulk density of about 160.2 Kg / m ³ or less are in sufficient contact with the treatment agent. However, materials having a bulk density of 160.2 Kg / m ³ or less are difficult to transport and / or shake by mechanical means because of their density. Thus, the material in which the treatment agent is added tends to come in contact with too much of the treatment agent. In contrast, materials located far from the point at which the treatment agent is added will tend to come in contact with too little of the treatment agent. Both "over-contacted" and non-contacted materials result in deterioration of the finished product.

Accordingly, a first object of the present invention is to overcome the shortcomings of known methods for treating materials with a bulk density of about 160.2 Kg / m ³ or less with a treatment agent.

Another object of the present invention is to provide a method of continuously treating a material having a bulk density of about 160.2 Kg / m ³ or less with a treating agent.

It is another object of the present invention to provide a method for treating a material having a bulk density of about 160.2 Kg / m ³ or less with a treatment agent, which greatly reduces the possibility of ignition.

Yet another object of the present invention is to provide a method for treating a material having a bulk density of about 160.2 Kg / m ³ or less, which provides a method for uniformly and sufficiently contacting the material with a treatment agent.

Another object of the present invention is a method of treating a material having a bulk density of about 160.2 Kg / m ² or less with a treatment agent, for a method that does not require frequent cleaning of the treatment means.

Other objects and advantages of the present invention will become more apparent from the following detailed description.

According to the present invention, materials having a bulk density of about 160.2 Kg / m ³ or less are treated with the treatment agent by contacting the treatment agent in a continuous manner while transferring the substance in the form of a dense phase between the storage vessel and the collection vessel. The contacted material may be heated in a container if necessary.

The main advantage of the present invention is that the material having a bulk density of about 160.2 Kg / m ³ or less can be continuously treated with the treatment agent.

Another advantage of the present invention is that the possibility of ignition in the container is significantly reduced.

Another advantage of the present invention is that the material having a bulk density of about 160.2 Kg / m ³ or less can be brought into uniform and uniform contact with the treating agent.

Another advantage of the present invention is that the treatment vessel does not need to be cleaned as often as in conventional treatment methods.

Other advantages of the present invention will become apparent from the following more detailed description of the invention.

An embodiment of the invention is shown in FIG. Materials having a bulk density of about 160.2 Kg / m ³ or less are stored in the workpiece storage container 10 and the treatment agent is stored in the treatment agent storage container 20. Since the material having a bulk density of about 160.2 Kg / m ³ or less stored in the vessel 10 is continuously pumped through the tube 14 in the form of a dense phase by the pump 12, the bulk density of the material in the tube is about 160.2. Kg / m ³ or less is maintained as it is. At the same time, the treatment agent is pumped into the tube 14 via the tube 24 and the injection means 26, whereby the treatment agent comes in contact with the substance having a bulk density of about 160.2 Kg / m ³ or less. If necessary, the treatment agent may be heated in the treatment agent storage container 20 or the tube 24. The material in contact with the treatment agent continues to enter the collection vessel 30 through the tube 14. If necessary, the collection vessel 30 may be heated to terminate the treatment of a material having a bulk density of about 160.2 Kg / m ³ or less with the treatment agent. The spraying means or nozzles 26 are used to evenly distribute the treatment throughout the tube 14 so that materials having a bulk density of about 160.2 Kg / m ³ or less are brought into uniform contact with the treatment. In the embodiment shown in FIG. 1, the treating agent is added in a direction substantially the same as the direction in which the material having a bulk density of about 160.2 Kg / m ³ or less flows through the tube 14. In addition, in the embodiment shown in FIG. 1, the tube 24 is projected slightly into the tube 14 at the portion where the tube 14 is bent at approximately 90 degrees, so that the injection means 26 is connected. It is arranged to be isolated from the side wall of the tube 14. As will be apparent to those of ordinary skill in the art, the position of the injection means or nozzles 26 in the tube 14 and the position in which the tube 24 and the tube 14 communicate with each other have a bulk density of about 160.2 Kg. It can be varied to achieve optimal contact between the specific material that is less than / m ³ and the specific treatment agent used to treat the material. Likewise, the direction in which the treatment agent is applied can also be changed.

The present invention is particularly suitable for treating fumed silica with a silane oil such as polydimethylsiloxane to render the fumed silica hydrophobic. The fumed silica is stored in the workpiece storage container 10 and the silane oil is stored in the treatment agent storage container 20. Pump 12 is a conventional diaphragm pump and pump 22 is a conventional pump. The collection vessel 30 is heated to a temperature sufficient to render the fumed silica product hydrophobic. The process is started by operating the pumps 12 and 22. By operating the pump, fumed silica is pumped from the to-be-processed container 10 through the tube 14, from the tube 14 via the tube 24 to the tube 14 through the injection means or the nozzle 26. Contact with the silane oil pumped into If necessary, the silane oil may be heated in the treatment reservoir 20 or the tube 24. The fumed silica and silane oils are pumped at different rates so that the overall final ratio of fumed silica and silane oil is from about 2: 1 to more by weight. After contact with the silane oil, the contacted fumed silica continues to flow into the collection vessel 30 via the tube 14. The present invention can be used to treat precipitated silica, fumed alumina, carbon black or aerogels in a similar manner.

Various modifications and variations can be made to the methods described herein without departing from the invention. Accordingly, it should be clearly understood that the embodiments of the invention described herein and shown in the accompanying drawings are exemplary only, and are not intended to limit the scope of the invention. The invention includes all modifications falling within the scope of the following claims.

Claims (15)

A volume characterized by a continuous contact of a substance having a bulk density of 160.2 Kg or less in a dense phase with the substance during the transfer from the workpiece storage vessel 10 to the collection vessel 30. A method of treating a material having a density of 160.2 Kg / m ³ or less. The method of claim 1 wherein the material is heated after contacting with the treatment agent. The method of claim 1 wherein said contacting is by spraying said treating agent onto said material. 4. The method according to claim 3, wherein the spraying is made by a spray nozzle (26) located inside the tube (14) while the material is transported through the tube (14). The method of claim 4, wherein the spraying is by spraying the treatment agent in a direction substantially the same as the direction of transport of the material. 5. The method according to claim 4, wherein the spray nozzle (26) is disposed in a curved portion of the tube (14) at an angle of about 90 degrees. The method of claim 1 wherein the ratio of material to treatment is from 1: 1 to 5: 1 by weight. The method of claim 1 wherein the material is fumed silica. The method of claim 8, wherein said treating agent is silane oil. 10. The method of claim 9, wherein said silane oil is polydimethylsiloxane. 10. The process of claim 9 wherein the ratio of fumed silica to silane oil is from 2: 1 to 5: 1 by weight. 10. The method of claim 9, wherein the silane oil is heated before contacting the material. The method of claim 1, wherein the material was hydrophilic prior to treatment with the treatment agent but hydrophobic after treatment with the treatment agent. The material according to claim 1, wherein the material having a bulk density of 160.2 Kg / m ³ or less is selected from the group consisting of fumed silica, precipitated silica, fumed alumina, carbon black and aerogel, and the treating agent is liquid, vapor, spray liquid and granular And a solid agent. The method of claim 1 wherein said treating agent is a liquid.

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