FR2639352A1 - PROCESS FOR CONTINUOUSLY PROCESSING A MATERIAL - Google Patents

Abstract

Disclosed is a process for continuously producing a material contacted by a treatment agent, which material has a bulk density of about 0.16 g / cm ** 3 or less. According to the invention, the material is contacted with a treating agent as it is transferred in dense phase from a storage container 10 to a container 30; the material can be heated after contact if necessary. The invention applies in particular to the production of fillers or reinforcing agents for improving the physical properties of compositions comprising rubbers, coatings, adhesives, paints and sealants.

Description

The present invention relates to a method

  for the treatment of a material having a specific gravity

  approximately 0.16 g / cm3 or less, by a processing agent

  in a continuous manner. More particularly, the invention relates to a method comprising the implementation of

  contact of the material having an apparent density of about

  0.16 g / cm3 or less with the treating agent while

  that matter is transferred in dense phase into a recipe

  and by heating the material contacted by the agent of

  treatment in the container if necessary.

  Substances having an apparent density of about

  at least 0.16 g / cm3 are commonly used as

  fillers or reinforcing agents to improve

  physical primer compositions comprising coating rubbers, adhesives, paints and sealants. Examples of these materials include,

  without limitation, fumed silicas, precipitated silicas

  smoked alumina, carbon blacks and

E; ge :.

  It is often desirable to treat these substances

  res having a bulk density of 0.16 g / cm3 or less to change their properties and make them more suitable for a particular purpose. The generally known treatment agents include, without limitation, liquids, vapors, atomized liquids, particulate solids,

  etc. In general, materials having a specific gravity

  of about 0.16 g / cm3 or less are treated with a treating agent at a ratio of about 1 to 5 parts, by weight, of the material to one part by weight of the agent.

treatment.

  For example, for many applications, it is desirable to employ a filler or reinforcing agent

  hydrophobic. Thus, if the material having a specific gravity

  rent of about 0.16 g / cm3 or less is normally

  phile, it must be treated to make it hydrophobic. As previously indicated, generally hydrophilic materials having an apparent density of 0.16 g / cm 3 or less are treated with treating agents to render them hydrophobic. Examples of such treating agents include, but are not limited to, silicone oils, silane oils, oils and the like.

  of dimethylsiloxane, and hydrofluoride vapors

  gbne. In general, about 1 to 5 parts by weight of the material having a bulk density of 0.16 g / cm 3 or less is treated with one part by weight of the treating agent. For example, in one embodiment of the present invention for treating fumed silica with a silane oil, about 2 - 5 parts by weight of fumed silica is treated with

  part, by weight, of silane oil.

  As previously described, an example of a material having a bulk density of 0.16 g / cm 3

  or less is the fumed silica. This matter,

  known as fumed silica, is a good agent

  reinforcement or load that is used

  to improve the physical properties of

  positions comprising silicone rubbers,

  coatings, adhesives and sealants.

  Smoke silica basically comprises particles

  finely divided silicon dioxide and generically

  typically an apparent density of about 0.08g / cm3 or less and a generally

between about 50 and 400 m 2 / g.

  Another example of a material having a den-

  Apparent value of 0.16 g / cm3 or less is the silica pre-

263935'2

  cipitée. Precipitated silica is also a well known reinforcing agent or filler commonly used to improve the physical properties of compositions comprising silicone rubbers, coatings, adhesives and sealants. The precipitated silica contains at the base

  finely divided particles of silicon dioxide

  and generally has a bulk density of about 0.16 g / cm or less. For some applications, it is

  desirable to use hydrophobic fumed silicas.

  In general, the hydrophilic fumed silica is rendered hydrophobic by treating the hydrophilic fumed silica with a treatment agent. For example, the patent

  U.S. 4,307,023 to Ettlinger et al discloses the treatment of

  of fumed silica with organometallic compounds

  silicon such as silicone oils to render the fumed silica hydrophobic and Calvin US Pat. No. 4,054,689 discloses the treatment of fumed silica with hydrogen fluoride vapors to render the fumed silica hydrophobic. Heat may be required to facilitate a reaction between the silica

smoke and the treatment agent.

  In general, the fumed silica is treated discontinuously in a container by filling the container with fumed silica and then putting the silica

  smoke in contact with a treatment agent. This pro-

  This is disclosed in US Patent No. 4,307,023. Mechanical mixing means may be employed

  to mix the fumed silica and the treatment agent.

  The container may also be heated during this process.

  yielded. A similar method is also disclosed in US Patent No. 4,780,108 to Razzano which discloses placing a low bulk density material in a mixing vessel and then spraying a treating agent onto the material while it is mixed turbulently. A discontinuous process is

  also disclosed in US Pat. No. 4,054,689 although in the

  disclosed in US Patent No. 4,054,689, the treating agent

  can be added to the container before the fumed silica.

  However, these methods of treating a material having a bulk density of about 0.16 g / cm 3

  or less by a setting treatment agent

  The tact of the material with the treating agent in a container has many disadvantages. First, these methods are not continuous. To maintain the

  desired ratio of the material having a density

  0.16 g / cm or less to the treatment agent,

  add a fixed amount of both to the recipe

  tainer. Then the final product must be completely removed from the container and the container cleaned. Therefore the

  process starts again with new quantities of

  with an apparent density of about 0.16 g / cm3

  or less and the treatment agent.

  Another disadvantage with the

  typically used is the means to add

  the container treatment agent frequently become clogged

  is lying. For example, in general, the treating agent is added to the container by injection means or other openings at the end of a tube or tubes. These

  injection molecules or openings can be found

  by the material having an apparent density of about

  0,16g / cm3 or less and therefore require a net

frequent cleaning.

  Moreover, given the fact that

  generally known are methods of the type known

  continuously, there is a tendency for the treating agent to agglutinate in the container or to collect on the injection means or the opening. Both the injection means and the opening and the container must therefore be cleaned to remove the balls of

  the treating agent and the treating agent collected.

  Similarly, if the container is heated, the balls

  of the treatment agent and / or the treatment agent

  appeared on the nozzle or opening can cause

  fires in the container. Fires can also

  occur if an excess of the treatment agent

  is not completely cleaned from the container.

  Another problem with the treatment of a

  With a bulking agent having an apparent density of about 0.16 g / cm3 or less by a treating agent by contacting the material with the treating agent in a container, it is ensured that all the material will be contacted.

  by the treatment agent. As previously discussed

  critically, mechanical means of mixing are often

  bent to attempt complete contacting of all material having an apparent density of about 0.16 g / cm3 or less with the treating agent. However, because of its density, a material having a bulk density of about 0.16 g / cm 3 or less is difficult to move and / or stir by mechanical means. Therefore, the material closest to the point where the treating agent is added will tend to be contacted by too much of the treating agent. Conversely, the material placed furthest from the point where the treating agent is added will tend to be contacted by too little of the treating agent. Both the "overcontented" material and the uncontacted material eventually reduce the quantity of the product

final.

  Accordingly, the subject of the present invention is

  to overcome the disadvantages of the known processes for the treatment of

  of a material having an apparent density of

  0.16 g / cm2 or less by means of a treating agent.

  Another object of the present invention is a

  continuous process for the treatment of a material having an apparent density of about 0.16 g / cm3 or less by a treating agent.

  Another object of the present invention is a

  for the treatment of a material having a relative density of about 0.16 g / cm3 or less by a

  treatment that significantly reduces the risk of fire.

  Another object of the present invention is a method for treating a material having an apparent density of about 0.16 g / cm3 or less by an agent where the material is uniformly and fully contacted with the agent.

treatment.

  Another object of the present invention is a

  assigned for the treatment of a material having an apparent density of about 0.16 g / cm3 or less by a treating agent that does not require frequent cleaning of the

means of treatment.

  According to the present invention, a material having an apparent density of about 0.16 g / cm3 or less is

  treated with a treating agent, by means of

  tact of the material with the treatment agent in a manner

  re continues while the material is transferred in dense phase between a storage container and a container. The contacted material may be heated in the container, if necessary. A major advantage of the present invention is that the material having an apparent density of about 0.16 g / cm 3 or less can be continuously

treated by the treatment agent.

  Another advantage of the present invention lies in the fact that the risk of fire in the container

is greatly reduced.

  Another advantage of the present invention lies in the fact that the material having an apparent density

  about 0.16 g / cm or less is regularly and uniformly

  are brought into contact with the treatment agent.

  Another advantage of the present invention lies in the fact that the container requires less frequent cleaning than in the processes used.

until now treatment.

  The invention will be better understood, and other purposes,

  characteristics, details and advantages of it

  will become clearer in the course of the description

  following diagram with reference to the schematic drawing.

  that annexed given only by way of example illustrating an embodiment of the invention, and wherein: - the single figure is a diagram of a mode of

  embodiment of the present invention.

  In the figure, one can see a material having an apparent density of about 0.16 g / cm3 or less, stored in the container 10 and a treatment agent stored in

  the container 20. The pump 12 continuously pumps the material

  having a bulk density of about 0.16 g / cm or less, through a tube 14, in a dense phase, so that

  the apparent density of the material in the tube is

  viron 0,16g / cm3 or less. At the same time, the pump 22 pumps the treatment agent through the tube 24, and the injection means 26, into the tube 14 where the treatment agent contacts the material having an apparent density of about

  0.16g / cm3 or less. If desired, the treating agent

  may be heated in the storage container 20 or

  in the tube 24. The material contacted by the processing agent

  It continues to flow through the tube 14 to the container 30. If necessary, the container 30 may be heated to finish the treatment of the material having an apparent density of about 0.16 g / cm 3 or less by the agent. treatment. Injection means 26 are used to uniformly distribute the treatment agent throughout the

  tube 14 and therefore to uniformly

  tact the material having an apparent density of about 0.16 g / cm3 or less with the treating agent. In the embodiment shown, the treating agent is added substantially in the same direction as that of the flow of material having an apparent density of about 0.16 g / cm or less through the tube 14. In this embodiment, also, the tube 24 communicates with the tube 14 at a bend of about 900 in the tube 14 and protrudes slightly inside the tube 14 so that

  the injection means 26 are placed far away from the

  lateral king of the tube 14. As this will easily be

  for any person competent in the matter, the location

  injection means 26 into the tube 14 and the

  placement of the communication of the tube 24 and the tube 14 can

  It can be changed to achieve optimum contact between the particulate material, having an apparent density of about 0.16 g / cm3 or less, which is treated, and the particulate treatment agent that is used to treat the material. Similarly, the direction in which the treatment agent

is added can be changed.

  The present invention is well suited to the treatment of

  Sicily smoked with silane oil,

  such as polydimethyl siloxane, to make silica fu-

  hydrophobic mea. The fumed silica is stored in the

  and the silane oil is stored in the container 20. The pump 12 is a conventional diaphragm pump and the pump 22 is a conventional pump. The container is heated to a temperature sufficient to render the fumed silica produced hydrophobic. At first the pumps 12

  and 22 are started. The fumed silica is thus pom-

  container 10 by the tube 14 where it is set

  with the silane oil pumped through the tube 24 and into the tube 14 by the injection means 26. If desired, the silane oil may be heated either in the storage container 20 or the tube 24 The fumed silica and silane oil are pumped at different rates so that the final total ratio of fumed silica to silane oil is about 2 to 1 by weight or more. After contacted with the silane oil, the contacted fumed silica continues to flow through the tube 14 into the container 30. The present invention can be used in a similar manner to treat precipitated silicas, fumed aluminas blacks

carbon or airgel.

Claims (15)

R E V E N D I C A T I 0 N S   1. Process for the continuous treatment of a material, characterized in that it consists in continuously   contacting a material having an apparent density of about   0.1 g / cc or less with a treating agent while said material is transferred in a dense phase of a   storage grade to a container.   2. Method according to claim 1, characterized in that it further consists in heating said material   after contact with the treatment agent.   3. Method according to claim 1, characterized   in that the bringing into contact consists in spraying the material by the treatment agent.   4. Method according to claim 3, characterized in that the material is transferred into a tube and in that the spray comprises injection means placed inside said tube.   5. Method according to claim 4, characterized in that the spray is moreover to inject   said treatment agent substantially in the same direction   than that of the course of the said material which is trans-   ferred. 6. Method according to claim 4, characterized in that the injection means are placed at an elbow about 90 in said tube.   7. Method according to claim 1, characterized in that the ratio by weight of the material to the agent of   treatment is about 1: 1 to 5: 1.   8. Process according to claim 1, characterized   in that the material comprises a fumed silica.   9. Process according to claim 8, characterized   in that the treatment agent comprises a silane oil.   10. Process according to claim 9, characterized   in that the silane oil comprises a polydimethyl   siloxane. 11. Process according to claim 9, characterized in that the ratio, by weight, of fumed silica to oil   the amount of silane is about 2: 1 to 5: 1.   12. Process according to claim 9, characterized in that the silane oil is heated before being contact of said material.   Method according to claim 1, characterized in that the material is hydrophilic before contact with the treating agent and hydrophobic after contact with said treatment agent.   14. A method of treating a material,   in that it consists in putting a material having an apparent density of about 0.16 g / cm 3 or less in contact with a liquid while said material is transferred   in the dense phase of a storage container to a container.   15. The method of claim 14, characterized   in that said material is hydrophilic prior to   tact with said liquid and hydrophobic after contact with said liquid.