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  • 专利说明
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    • 专利摘要:
    The present invention relates to a device (1) and a mixing process for the manufacture of a composite material from at least one powder comprising carbon nanofillers such as CNTs, and at least one elastomeric resin. According to the invention, the device comprises a mixer (2) for mixing the powder with the elastomeric resin; a feed system (10) for introducing the powder into the mixer, said feed system comprising a loading device (14) cooperating with a feed screw (11) opening into the mixer; a piston (30) adapted to move from the stack (5) into the mixer, and contributing with said mixer to the mixture of the powder with the elastomeric resin. The invention applies to the manufacture of composite materials.
    公开号:FR3029926A1
    申请号:FR1462507
    申请日:2014-12-16
    公开日:2016-06-17
    发明作者:Alexander Korzhenko；Serge Bordere；Amelie Merceron
    申请人:Arkema France SA；
    IPC主号:
    专利说明:

    [0001] TECHNICAL FIELD The invention relates to the field of composite materials based on polymeric resins, and more particularly that of the materials used in the manufacture of a composite material from a powder comprising carbon nanobeads and an elastomer resin. composites obtained from polymer resin and carbon nanofillers. In the following description is meant by carbon nanofillers, carbon nanotubes (CNTs), carbon nanofibers, graphene, carbon black, or a mixture of said carbon nanofillers, or carbon nanotubes in association with another nanoburden. The invention is particularly but not exclusively applicable to the production of composite materials obtained from polymer resin and carbon nanotubes (CNTs) alone or in combination with the aforementioned nanofillers. More particularly, the invention relates to a device for the manufacture of a composite material from at least one powder comprising carbon nanofillers and preferably carbon nanotubes (CNTs), and at least one resin polymer consisting of a thermosetting elastomeric resin. The invention also relates to a method of manufacturing such a composite material, as well as a composite material part obtained by the implementation of this method. Prior Art [0005] Elastomers are polymers with rubber-elastic properties which find application in various fields, including the manufacture of automotive parts such as tires, seals or tubes, pharmacy, industry electrical, transport or building, for example. In some of these applications, it may be advantageous to give them electrical conduction properties and / or to improve their mechanical properties. To do this, it is possible to incorporate conductive fillers such as carbon nanotubes (or CNTs). [0006] The incorporation of nanofillers like CNTs into elastomeric compositions is, in the industry, conditioned by the mixing techniques and the equipment used. Under customary conditions, a polymer resin, particularly an elastomeric resin, is introduced into a mixer, and then other components are added to the elastomeric resin, in the mixer, and in predetermined amounts. However, this technique is difficult to apply in the case of adding nanofillers such as CNTs to an elastomeric resin. In fact, CNTs tend to form aggregates. Thus, a portion of the CNTs introduced into the mixer remain in the form of aggregates which are then encapsulated in the resin instead of being dispersed homogeneously within said resin. Another part of the CNTs is positioned in the mixer without mixing with the resin, and is often lost in the emptying press or carried away by the flow of air flowing in the installation. [0007] WO 2007/035442 describes a process for incorporating from 0.1 to 30% by weight, and preferably from 0.1 to 1% by weight, of CNT into a liquid or solid silicone resin base, consisting of to disperse these into the resin base using conventional mixing devices, roll mills or ultrasonic mills. Example 7 of this document more specifically discloses a 25% by weight NTC masterbatch prepared by dispersion of the CNTs in a silicone resin base using a Waring Mixer (Knife Mixer). The masterbatch obtained is in the form of a wet free powder. The technique proposed in this document does not make it possible to disperse amounts greater than 25% by weight of charges of as low bulk density as the CNTs. In particular, it is not possible to incorporate in the resins these levels of CNT without substantially forming aggregates of more than 10 pm from them, given their naturally very entangled structure. This poor dispersion of CNTs leads to embrittlement of the composites formed therefrom, which results in particular in the appearance of nanofissures. Furthermore, knowing that the apparent density of the CNT is about ten times lower than that of the elastomeric resin, the loading of the CNTs in the Ref: 0430-ARK54 3029926 3 mixer is not easy. It is often performed via large volume bags containing a predetermined amount of CNT powder, which is poured directly into the mixer. The disadvantage of this method is that it leads to a heterogeneous mixture of CNTs in the elastomeric resin, which generally results in resins or composite materials having poor mechanical properties. [001 0] WO 2010/109118 discloses a process for preparing a composite material containing more than 5% by weight and up to 70% by weight of carbon nanotubes, and comprising the introduction of a base of elastomer and NTC resin in a co-kneader, kneading these two components, then recovering the formed composite material. The CNT powder is introduced into the co-kneader through the feed hopper of said co-kneader. However, this document does not describe any particular method of introduction of the CNT powder into the co-kneader making it possible to avoid the formation of CNT aggregates in said mixer and to obtain a homogeneous mixture of CNTs in the mixer. the elastomeric resin. The invention therefore aims to overcome the disadvantages of the prior art by providing a device for the manufacture of a composite material from at least one powder comprising carbon nanotubes (CNTs), and at least one elastomeric resin base for controlling and regulating the introduction of the powder comprising CNTs when mixing the elastomeric resin with said powder. The device thus makes it possible to obtain a homogeneous mixture of the powder with the elastomeric resin, and thus to obtain a composite material having good mechanical properties. The device also makes it possible to manufacture a composite material optimally ensuring the safety of the operator. BRIEF DESCRIPTION OF THE INVENTION [0012] For this purpose, the invention relates to a mixing device for the manufacture of a composite material from at least one powder comprising carbon nanofillers, and to at least one elastomer resin, mainly characterized in that it comprises: - a mixer for mixing the powder with the elastomer resin, said mixer comprising a chimney, - a feed system for introducing the powder into the mixer, said feeding system comprising a loading device cooperating with a feed screw opening into the mixer, a piston able to move in the mixer chimney and to contribute with said mixer to the mixture powder with the elastomeric resin. According to other optional characteristics of the mixing device: the loading device comprises a container connected to a double valve coupling device ensuring the passage of the powder in the feed screw in a secure manner; The coupling device comprises an active valve connected to the container and a passive valve connected to the powder introduction inlet in the feed screw, the active valve and the passive valve being intended to be connected to enable transferring the powder from the container into the feed screw; The feed screw of the feed system has a Length / Diameter ratio, referred to as the L / D ratio, ranging from 10 to 70, preferably from 20 to 70 and preferably from 40 to 60. The mixer comprises an airlock loading device constituting the inlet of said mixer, the loading lock being connected to the feed screw, so that the powder enters directly into said lock after the exit of the feed screw, said mixer further comprising a chamber of mixture located under the loading chamber and capable of communicating with said airlock; 25 - The loading chamber is provided with a sealed secure closure separating said loading chamber from the mixing chamber; Advantageously, the secure closure is achieved by the piston head and / or by a door. Ref: 0430-ARK54 3029926 5 - The loading chamber further comprises a door allowing the introduction of the polymer resin in said lock; Advantageously, the resin introduction door is fixed to the airlock so as to be able to tilt backward outside the airlock, said door also comprises flanks on the sides facilitating the introduction of the resin. The mixer comprises extraction means comprising prefilters and filters; The powder comprising carbon nanofillers comprises carbon nanotubes (CNTs) or nanofibers of carbon or graphene, or carbon black, or a mixture of said carbon nanofillers, or preferably carbon nanotubes alone or in combination with another nanoburden. - The powder comprising carbon nanofillers introduced into the mixer further comprises at least one vulcanizing agent; The powder comprising carbon nanofillers introduced into the mixer further comprises at least one additive. Advantageously, the powder comprising carbon nanofillers comprises carbon nanotubes (CNTs). The invention furthermore relates to a method for manufacturing a composite material comprising at least one powder comprising carbon nanocharges, and at least one elastomer resin, said process being implemented by the mixing device previously described, mainly characterized in that it comprises the following steps: a) Introduction of the elastomeric resin into the mixer, b) Introduction of the powder into the mixer via the feed system and control of the feed rate by a adjusting the speed of rotation of the feed screw, c) Mixing of the elastomer resin and the powder in the mixer in order to obtain a composite material, d) shaping of the composite material obtained in step c) . Ref: 0430-ARK54 3029926 6 [0015] According to other optional characteristics of the manufacturing process: - The powder comprising carbon nanofillers comprises carbon nanotubes (CNTs) or carbon nanofibers or graphene, or carbon black or a mixture of said carbon nanofillers, or preferably carbon nanotubes alone or in combination with another nanofiller. The quantities of elastomer resin and of powder introduced during steps a) and b) are such as to make it possible to obtain a composite material during step c), the mass percentage of which of which is in the range of 1% at 60%, preferably greater than 10% in this range; preferably greater than 20%, and more preferably greater than 30%. The mass percentage of CNTs in the composite material is less than 60%, preferably less than 50%, and more preferably less than 40%. The mass percentage of CNTs in the composite material is preferably between 30% and 40%. . - In step b), the powder comprising CNTs is introduced into the mixer in a sequenced manner, according to one or more powder volume introduction sequences corresponding to a fraction of the total volume of powder to be introduced, each sequence comprising one or more powder introductions; The powder is introduced into the mixer via the feed system according to an integer n of sequences, each sequence comprising an integer number of powder introductions, preferably n is between 1 and 5, and advantageously between 2 and 3 and preferably i is from 1 to 10, and preferably from 4 to 8; - The method of manufacturing a composite material comprises, prior to step b), a step of mixing the elastomeric resin, then only in the mixer for a period of between 1 minute and 15 minutes, preferably between 1 minute and 10 minutes, more preferably the mixing time of the elastomeric resin is 5 minutes and the mixing temperature of the elastomeric resin is in a range of 100 ° C to 160 ° C, the Ref: 0430- ARK54 3029926 7 resin having a temperature in a range of 40 to 60 ° C before the introduction of carbon nanofillers. Other advantages and characteristics of the invention will appear on reading the following description given by way of illustrative and nonlimiting example, with reference to the appended figures which represent: FIG. 1, a diagram of the device 2, a diagram of the mixer and the piston, said piston being in the raised position, FIG. 3, a diagram of the mixer and of the piston, said piston being in the low position, FIG. optical microscope image of a composite material plate obtained by the use of the mixing device according to example 1 according to the invention; - FIG. 5, an optical microscope image of a composite material plate obtained by the implementation of the mixing device according to Example 2, according to the invention. DETAILED DESCRIPTION OF THE INVENTION [0017] The elastomeric resin comprises, or even consists of, one or more polymers chosen from: fluorocarbon or fluorosilicone polymers; nitrile resins; homo- and copolymers of butadiene, optionally functionalized with unsaturated monomers such as maleic anhydride, (meth) acrylic acid, and / or styrene (SBR); neoprene (or polychloroprene); polyisoprene; copolymers of isoprene with styrene, butadiene, acrylonitrile and / or methyl methacrylate; copolymers based on propylene and / or ethylene and in particular terpolymers based on ethylene, propylene and dienes (EPDM), as well as copolymers of these olefins with an alkyl (meth) acrylate or vinyl acetate; halogenated butyl rubbers; silicone resins; polyurethanes; polyesters; acrylic polymers such as polybutyl acrylate bearing acid functions Ref: 0430-ARK54 3029926 8 carboxylic acid or epoxy; as well as their modified or functionalized derivatives and their mixtures. Preferably, the elastomeric resin comprises, or even consists of, one or more polymers chosen from: nitrile resins, in particular copolymers of acrylonitrile and butadiene (NBR); silicone resins, in particular poly (dimethylsiloxanes) bearing vinyl groups; fluorocarbon polymers, in particular copolymers of hexafluoropropylene (HFP) and vinylidene difluoride (VF2) and terpolymers of hexafluoropropylene (HFP), vinylidene difluoride (VF2) and tetrafluoroethylene (TFE), each monomer which can represent more than 0% and up to 80% of the terpolymer; and their mixtures. The following description is made with as an embodiment a powder comprising carbon nanofillers comprising carbon nanotubes (CNTs). The powder described hereinafter comprises carbon nanotubes, but in addition to carbon nanotubes, other compounds. It comprises for example at least one vulcanizing agent such as sulfur derivatives or organic peroxides, and optionally a vulcanization accelerator, as well as various additives such as antioxidants, lubricants, pigments (zinc oxide, lithopone by for example), stabilizers, fillers or reinforcements, anti-static agents, fungicides, flame retardants, texturizing agents, electrical conductivity improvers (structured carbon black for example). The compounds present in the powder, in addition to the CNTs, are necessarily in the form of a powder so as to form a mixture of powders. Preferably, the particle size of the powder or mixture of powders is less than or equal to 1000 μm. In the following, the term "powder" denotes a powder comprising CNTs or a mixture of powders comprising CNTs may comprise other compounds. The mixing device 1 for the manufacture of a composite material 30 according to the invention is shown in the Figurel. It comprises a feed system 10 linked to a mixer 2, and for introducing a powder comprising CNTs into the mixer. Ref: 0430-ARK54 3029926 9 [0022] The feed system comprises a feed screw 11 connected to a loading device 14 cooperating with said screw for the introduction of the powder into the mixer 2. The feed screw 11 allows the transfer of the powder comprising CNTs from the loading device 14 to the mixer 2. It is located in a sleeve 12 and comprises a helical groove so as to constitute a worm. In addition, it has a Length / Diameter ratio, said L / D ratio, ranging from 10 to 70, preferably from 20 to 70 and preferably from 40 to 60. The sleeve 12 containing the feed screw 11 may be heated to allow the introduction of the powder into the mixer 10 at a temperature above room temperature. Preferably, the sheath is not heated and the introduction of the powder into the mixer is then carried out at room temperature. The feed screw 11 also comprises a shaft movable in rotation about its longitudinal axis, and whose rotation is generated by a motor 13.
    [0002] The rotation of the shaft causes the rotation of the screw, and thus the displacement of the powder located in the cavities of the screw delimited by the shaft, the helical groove, and the sheath, to the mixer.  Adjusting the speed of rotation of the feed screw 11 makes it possible to adjust the rate of introduction of the powder comprising CNTs into the mixer 2, and thus to regulate and control the quantity of powder introduced into the mixer, so as to obtain an optimal mixture of said powder and the elastomeric resin in said mixer.  A first end of the feed screw 11 opens on the loading chamber 3 of the mixer 2, and a second end of said screw is connected to the loading device 14 of the feed system 10.  Said device for loading the powder comprising CNTs comprises a container 18 adapted to be connected to a double valve coupling device 19, of the butterfly valve or Buck® valve type sold by the company GEA Pharma Systems and described in the document WO 2009 / 098424.  In particular, the container 18 consists of a metal drum containing a predetermined amount of powder comprising CNTs.  By predetermined quantity is meant a quantity of powder such as the final mass percentage of CNT in the composite material, that is to say the ratio Ref: 0430-ARK54 3029926 ratio between the mass of CNT introduced and the mass of composite material obtained, corresponds to the desired value.  Preferably, the mass percentage of CNTs in the composite material is NTC is in the range of 1% to 60% and preferably greater than 10% and up to 60%; preferably greater than 10% in this range; preferably greater than 20%, and more preferably greater than 30%.  This percentage is preferably less than 60%, preferably less than 50%, and more preferably less than 40%.  In a preferred example, the mass percentage of CNTs in the composite material is between 30% and 40%.  At this predetermined amount is a volume and a mass of CNT powder.  The double valve coupling device 19 comprises a first valve 15, called active valve, and a second valve 16, called passive valve.  The active valve 15 is connected to the container 18 and the passive valve 16 is connected to the inlet 110 for introducing the powder of the feed screw 11.  The dual valve coupling device 19 comprises an opening control 17 located at the periphery of the active valve 15 and allowing the opening and closing of the valves of the coupling device.  Opening is only possible when the two valves are coupled to each other.  The opening control 17 is locked in the absence of coupling.  Such a device makes it possible to transfer the powder comprising CNTs to the feed screw safely, without leakage of said CNTs to the external medium, and without contact between the powder comprising CNTs and the external medium.  Thus, the volume of powder entering the feed screw corresponds precisely to the volume of powder that it is desired to use for the manufacture of the composite material initially present in the container 18.  It is also possible to control the opening, and in particular the degree of opening of the active and passive valves of the coupling device 19 to vary the rate of introduction of the powder comprising CNTs in the mixer, of in order to obtain an optimum mixture of said powder and elastomer resin in the mixer.  The supply system 10 forms a perfectly isolated circuit of the external medium, so that the transfer of the powder from the container 18 to the Ref: 0430-ARK54 3029926 11 mixer 2 is carried out without contact between said powder and said external medium.  The volume of powder entering the mixer 2 corresponds precisely to the volume of powder that it is desired to use for the manufacture of the composite material, transferred from the feed screw 11.  The supply system 10 5 thus makes it possible to substantially increase the accuracy of the volume of powder introduced into the mixer 2.  Furthermore, the control of the rate of introduction of the powder into the mixer 2 through the feed system 10 allows a better incorporation of the powder comprising CNTs in the elastomeric resin, and 10 thus contributes to obtaining of a homogeneous composite material, without aggregates, in particular without CNT aggregates, and having good mechanical and / or electrical properties, being known that CNTs are excellent electrical conductors.  The mixer 2 advantageously comprises a loading chamber 3 constituting the inlet of said mixer, and opening onto the mixing chamber 6.  The loading lock 3 is connected to the feed screw 11, so that the powder enters directly into said lock after the output of the feed screw.  The loading chamber 3 is surmounted by a chimney 5 and comprises a door 50 allowing the introduction of the polymer resin into said airlock.  Advantageously, the door 50 is a door fixed to the lock so as to be able to swing backward outside the airlock, said door also has flanks on the sides facilitating the introduction of the resin.  Advantageously, the door 5 is provided with hinges on its lower base to allow tilting back outwards and the flanks close the gap between the airlock and the edges of the door preventing the resin from falling out of the airlock .  The loading chamber 3 is provided with a tight sealed closure 4 separating said loading chamber from the mixing chamber 6.  The closure 4 is made by the piston head 30 and / or by a door provided for this purpose.  By mixer is meant in the present description, an apparatus 30 conventionally used in the plastics industry for the melt blending of thermoplastic polymers and additives to produce composites.  In this apparatus, which usually comprises a rotor provided with vanes adapted to cooperate with teeth mounted on a stator, the polymeric composition and the additives are mixed under high shear.  The melt generally comes out of the apparatus in an agglomerated solid physical form, for example in the form of granules, or in the form of rushes, tape or film.  Examples of mixers used according to the invention are the mixers BUSS MDK 46 and those of the series BUSS MKS or MX, sold by the company BUSS AG, which all consist of a screw shaft provided with fins, disposed in a heater sleeve optionally consisting of several parts and whose inner wall is provided with kneading teeth adapted to cooperate with the fins to produce a shear of the kneaded material.  The shaft is rotated and provided with oscillation movement in the axial direction by a motor.  These mixers may be equipped with a granule manufacturing system, adapted for example to their outlet orifice, which may consist of an extrusion screw or a pump.  Advantageously, the mixer is an internal mixer with two screws (not shown in the diagrams), allowing optimal mixing of the components.  The mixer 2 is also provided, at its lower end, with a drainage flap 7 located directly above a receiving hopper 21.  Thus, when the step of mixing the elastomer resin and the powder comprising CNTs is complete, the emptying hatch 7 is opened and the newly formed composite material falls into the receiving hopper 21.  The drain hatch and the receiving hopper are separated by a safety slide 20 which prevents the content of the mixing chamber 6 from falling into the receiving hopper 21 when the drain hatch has been opened by mistake.  When the composite material is formed and the mixing step is complete, the safety slide 20 and the drain hatch 21 open, allowing the transfer of the composite material from the mixing chamber 6 to the receiving hopper 21.  The safety slide 20 can be opened before or simultaneously with the opening of the emptying hatch 21.  Ref: 0430-ARK54 3029926 [0037] The mixing device 1 for the manufacture of the composite material further comprises a piston 30 comprising a body 31 and a base 32.  The piston body 31 passes through the upper end of the mixing chamber 6, so that part of the piston body is in the chamber and another part is in the chimney 5 of said chamber.  Thus, the piston 30 is able to move in the chimney 5 of the mixer 2 to the mixing chamber 6 between at least a first position, said high position illustrated in Figure 2, and at least a second position, said position. bass shown in Figure 3.  In the raised position, the piston 30 is not in contact with the elastomer resin-powder mixture comprising CNTs.  When the piston 30 is in the up position, as shown in FIG. 2, the elastomer-powder resin mixture comprising NTCs occupies a volume VMi, or volume of resin-powder mixture at the i-th powder introduction, defined by its length L, its width I, and its height h.  This volume may vary, during the implementation of the manufacturing method according to the invention, between a volume VMO corresponding to the volume of initial resin-powder mixture when only the polymer resin has been introduced into the mixing chamber, and a volume VMf corresponding to the final mixing volume when all of the powder comprising CNTs has been introduced into said mixing chamber.  When the piston 30 is in the down position, as shown in FIG. 3, a lower portion of the piston, including the base 32, is immersed in the polymer-powder resin mixture.  At the volume VMi occupied by the polymer-powder resin mixture at the i-th powder introduction is added the volume of the part of the piston immersed in said mixture denoted VP, so that the total volume at the i-th introduction of powder noted VT is such that VTi = VMi VP.  This volume VTi is defined by its length L, its width I, and its height H, with H greater than h.  The elastomer resin is preferably introduced at one time into the loading chamber 3 by the door 50, then into the mixing chamber 6 following the opening of the secured door 4 of the loading chamber 3 and / or piston in high position.  It is also possible to introduce the elastomeric resin in several times.  In all cases, all of the elastomeric resin is introduced into the mixing chamber 6 of the mixer 2 before the introduction of the powder comprising CNTs into said mixer.  The elastomeric resin is introduced in the solid form, for example in the form of ground particles in the mixer 2 and liquefied in the mixer 5 by heating and shearing before the introduction of the CNTs, the temperature of the resin being heated. and rising to a value of 40 ° C to 60 ° C.  The powder comprising CNTs is introduced into the mixer 2 sequentially, that is to say according to one or more introduction sequences of a volume of powder corresponding to a fraction of the total volume of powder at 10. introduce.  Each sequence may include one or more powder introductions.  The volume of powder added at each introduction may be the same or different from one introduction to another.  Preferably, the volume of powder added at each introduction is identical from one introduction to another.  Likewise, the volume of powder introduced at each sequence may be the same or different from one sequence to another.  Preferably, the volume of powder introduced at each sequence is different from one sequence to another.  Between each introduction of powder in the mixing chamber 6, the piston 30 is lowered in the low position and is then in contact with the resin-powder mixture.  The descent of the piston, in contact with the volume mixture VMi, causes a rise in the level of said mixture, the total volume occupied by the mixture and the piston being VTi = VMi VP, and the height passing from h to H, with H greater than or equal to h.  The displacement of the piston 30 and the rise of the level of the mixture makes it possible on the one hand to mix, with the elastomeric resin, the CNTs which may have been deposited on the walls of the chamber 6 of the mixer.  This makes it possible to limit the losses of CNT not incorporated in the resin after mixing, and contributes to obtaining a volume of powder effectively mixed with the resin substantially equal to the total volume of powder introduced into the mixing device.  [0044] On the other hand, the resin-powder mixture is especially mixed near the mixer screws.  The portion of said mixture which is remote from said screws is much less mixed.  This results in a heterogeneous mixture.  The displacement of the piston 30, inducing the compression of the mixture and the variation of the height of said mixture, makes it possible to optimally mix the entire volume of said mixture, and thus to obtain a homogeneous composite material. , with a very good dispersion of the powder, and in particular of CNT, in the elastomeric resin.  The control and regulation of the rate of introduction of the powder comprising CNTs in the mixer 2 by the feed system 10, and the displacement of the piston 30 in said mixer from compressing the elastomer-powder resin mixture, allow to obtain a homogeneous composite material, with a reduced number of defects compared to techniques known to those skilled in the art, and with good properties including mechanical and electrical.  The mixing device 1 according to the invention may further comprise extraction means comprising in particular prefilters and filters, to minimize the pressure losses at the air flow, and thus reduce the risks. for an operator when using such a mixing device.  The extraction means are provided at the loading chamber, the mixing chamber, the safety slide, and the receiving hopper, and are respectively numbered 23, 24, 25, 26 in FIG.  The extraction means are generally provided at each stage of the process for manufacturing the composite material until the transfer of said composite material into the receiving hopper 21, except at the powder supply system 10 where they are not present. necessary because of the presence of the double valve coupling device 19.  During the introduction of the elastomeric resin in the loading chamber 3, then in the mixing chamber 6 after opening by opening the secured door 4 and / or piston in the up position, the extraction means 23 of said Loading locks are turned on, with a high extraction rate, in order to avoid any contact of the resin particles that may be present in the air with the operator.  Then, the extraction flow rate is reduced during the introduction of the powder into the loading chamber 3, then into the mixing chamber 6, in order to avoid forming a cloud of particles of powder suspended in said airlock 30. loading.  The extraction means 24 of the mixing chamber 6 are started during the introduction of the powder and / or the elastomer resin into said chamber, and preferably operate during the entire duration of the mixing step.  The extraction means 25 of the safety slide 20 and the receiving hopper 21 are turned on during the emptying of the mixing chamber 6 5 of the mixer, and preferably work until the hopper no longer contains composite material.  When the mixing step is complete, and the composite material has been obtained and transferred from the mixing chamber 6 to the receiving hopper 21, said composite material is capable of undergoing several transformation steps. in particular by calendering, by passages in calenders 22, to be put into a form suitable for further use.  Preferably, the composite material undergoes one or more calendering steps to form plates.  More preferably, these plates have a length equal to 1 meter, a width equal to 1 meter, and a small thickness so that said plates are able to be cut by a user without the use of industrial cutting means, for example with a cutter.  It is also possible to shape the composite material to obtain ribbons, packaging, or any other structured or semistructured part that can be obtained by shaping such a composite material.  The composite material obtained can be shaped by any suitable technique, including injection, extrusion, compression or molding, followed by a vulcanization treatment.  A vulcanizing agent may be added to the composite material.  The addition of the vulcanizing agent can be carried out during the mixing step (in the case where its activation temperature is higher than the mixing temperature).  However, it is preferred that it be added to the composite material immediately before or during its shaping, so as to have more latitude to adjust the properties of the composite.  Alternatively, the composite material according to the invention can be used as a masterbatch and thus diluted in a polymer matrix to form a composite product after shaping.  Again, the vulcanizing agent can be introduced either during the mixing step, or preferentially in the matrix Ref: 0430-ARK54 3029926 17 polymer, that is to say during the formulation of the latter or during of his fitness.  In this embodiment of the invention, the final composite product may for example contain from 0.01% to 35% by weight of CNT, preferably from 1.5 to 20% by weight of CNT.  The polymer matrix generally contains at least one polymer selected from random or thermosetting graded, block, random or block homo- or copolymers.  At least one polymer chosen from those listed above is preferably used according to the invention.  Advantageously, the polymer included in the polymer matrix belongs to the same chemical class (nitrile resin, silicone resin or fluorocarbon polymer, for example) as at least one of the polymers of the elastomeric resin obtained by the manufacturing method according to the invention. invention.  The polymer matrix may furthermore contain at least one vulcanizing agent such as sulfur derivatives or organic peroxides, and optionally a vulcanization accelerator, as well as various adjuvants and additives such as antioxidants, lubricants, pigments (eg zinc oxide, lithopone), stabilizers, fillers or reinforcements, antistatic agents, fungicides, flame retardants, texturizing agents, electrical conductivity improvers (structured carbon black, for example) and solvents.  The composite product thus obtained can in particular be used for the manufacture of body seals or sealing, tires, noise plates, static dissipators, internal conductive layer for high and medium cables. tension, or anti-vibration systems such as automobile shock absorbers, or in the manufacture of structural elements bulletproof vests.  According to the present invention, the method of manufacturing a composite material comprising at least one carbon nanofillers powder, and at least one elastomeric resin, is implemented by the mixing device 1 described above and comprises the following steps: - a) Introduction of the elastomer resin in the mixer 2, Ref: 0430-ARK54 3029926 18 - b) Introduction of the powder into the mixer 2 via the feed system 10 and control of the feed rate by a setting of the speed of rotation of the feed screw, c) mixing of the elastomer resin and the powder in the mixer to obtain a composite material, - d) shaping of the composite material obtained in step c) .  The powder comprises carbon nanotubes (CNTs).  The quantities of elastomer resin and of powder introduced during steps a) and b) are such that they make it possible to obtain a composite material during step c), the mass percentage of which is in the range of from 1% to 60% and preferably above 10% in this range.  The mass percentage of CNT is preferably greater than 20%, and more preferably greater than 30%.  Advantageously, the mass percentage of CNT is less than 60%, preferably less than 50%, and more preferably less than 40%.  In a preferred example, the mass percentage of CNTs in the composite material is between 30% and 40%.  The method according to the invention may comprise, prior to step b), a step of mixing the elastomeric resin, then only in the mixer.  The mixing time of the elastomeric resin is 1 minute and 15 minutes, preferably 1 minute to 10 minutes, more preferably the mixing time of the elastomeric resin is 5 minutes and the mixing temperature of the elastomeric resin is in a range of 100 ° C to 160 ° C, the resin having a temperature in a range of 40 to 60 ° C prior to the introduction of the NTCs (carbon nanofillers).  In step b), the powder is introduced into the mixer via the feed system according to an integer number n of sequences, each sequence comprising an integer number i of powder introductions.  Preferably, n is between 1 and 5, and advantageously between 2 and 3.  Preferably, i is between 1 and 10, and advantageously between 4 and 8.  Each sequence is characterized by its number of introductions i, and its time necessary to perform all the introductions it comprises.  For example, and as illustrated in Example 1 hereinafter, the powder introduction step b) may comprise a first 15-minute sequence comprising 5 powder introductions, and a second 15-minute sequence comprising 5 powder introductions, and a second 15-minute sequence comprising 5 powder introductions, and a second sequence of 20 minutes comprising 2 powder introductions.  Thus, it will take 15 minutes to complete the 5 introductions 5 of the first sequence, then 20 minutes to perform the 2 introductions of the second sequence.  The time of a sequence is generally between 5 minutes and 30 minutes, preferably between 5 minutes and 15 minutes.  Moreover, the amount of powder introduced at each introduction, in a given sequence, is identical or different from one introduction to another.  Similarly, the amount of powder introduced to each sequence is the same or different from one sequence to another.  The time of a sequence is identical or different from one sequence to another.  Preferably, the time of one sequence is different from one sequence to another.  Similarly, the time of an introduction, for a given sequence, is identical or different from one introduction to another.  Preferably, the time of an introduction, for a given sequence, is identical from one introduction to another.  The rate of introduction of the powder into the mixer during step b), depending in particular on the speed of rotation of the feed screw, the degree of opening and the opening time of the double valve device, is thus adapted accordingly.  Between each introduction of a given sequence, and after the last introduction of a given sequence, the piston 30 is lowered in order to compress the mixture and allow better incorporation of the powder into the elastomeric resin.  The piston 30 and the motor 13 for driving the feed screw 11 are controlled by means of a PLC programmed for this purpose.  When mixing the elastomer resin and the powder in step c), the speed of rotation of the mixer is between 10 rpm and 40 rpm, preferably between 20 rpm and 30 rpm. revolutions / minute.  In addition, the mixing step is generally carried out at a temperature which is greater than the glass transition temperature (Tg) for the amorphous polymers and at the melting temperature for the semi-crystalline polymers. crystalline.  This temperature is a function of the polymer specifically used and generally mentioned by the supplier of the polymer.  By way of example, the mixing temperature can range from room temperature to 260 ° C, for example from 80 to 260 ° C, preferably from 100 to 220 ° C, and more preferably from 100 to 150 ° C.  [0068] Preferably, the mixer chamber is not heated and the mixture is produced at room temperature, or at a temperature above room temperature following the heating caused by the shearing of the components during mixing.  When all of the powder has been introduced into the mixer according to step c), the speed of rotation of the mixer is increased so that the temperature of the mixture is greater than or equal to 150 ° C.  The safety slide 20 and the emptying hatch 7 are then opened so as to empty the mixing chamber 6 and to transfer the composite material into the receiving hopper 21.  Examples of implementation of the process for manufacturing the composite material with the device according to the invention The following examples relate to a non-optimized protocol (Example 1) and an optimized protocol (Example 2) for manufacturing a composite material, and show the impact of powder introduction sequencing comprising CNTs in the mixer.  Example 1: Non-optimized protocol for introduction of the powder comprising NTC [0070] 12 kg of a fluorinated elastomer resin are introduced into the mixing chamber of the mixer via the loading chamber.  The entire fluorinated elastomer resin is introduced at one time.  The resin is mixed for 30 minutes at a temperature between 30 ° C and 40 ° C.  Then several times, i.e., several introduction sequences, are introduced 3. 2 kg of carbon nanotube powder (CNT) C100 of the brand Graphistrength Ref: 0430-ARK54 3029926 21 manufactured by the company ARKEMA, and packaged in metal drums of 60 liters.  The sequences for introducing the CNT powder into the mixer are the following: - 5 introductions, 15 minutes of mixing after each introduction 5 - 2 introductions, 20 minutes of mixing after each introduction [0071] The piston goes down and then goes up in high position between each introduction of powder.  The speed of rotation of the mixer is between 20 rpm and 30 rpm.  The temperature of the mixture is about 120 ° C.  After the last powder introduction, the piston is lowered and then raised three times in order to optimize the mixing of the powder and the elastomer resin.  The speed of rotation of the mixer is increased until the temperature of the mixture is approximately equal to 150 ° C., and the mixer is then drained.  The composite material obtained undergoes several calendering stages until a homogeneous plate is obtained which is easy to handle and simple and quick to cut.  The plate is analyzed under an optical microscope, and the image shown in Figure 4 is obtained.  At the macroscopic level, the plate is regular which implies a relatively homogeneous mixture of the powder and the elastomeric resin.  However, optical microscopy reveals a plate dotted with spots 40 corresponding to the NTCs encapsulated in the elastomeric resin.  The dispersion is therefore satisfactory because the plate obtained has good properties, in particular mechanical and electrical properties, but is not optimal.  EXAMPLE 2 Optimized Protocol for Introducing Powder Including CNT [0073] 12 kg of a fluorinated elastomer resin are fed into the mixing chamber of the mixer via the loading chamber.  The entire fluorinated elastomer resin is introduced at one time.  The resin is mixed for 30 minutes at a temperature between 20 ° C and 30 ° C.  Then introduced in several times, that is to say in several introduction sequences, 3. 2 kg of a carbon nanotube powder (NTC) C100 Graphistrength 30 brand manufactured by ARKEMA, and packaged in metal drums of 60 Ref: 0430-ARK54 3029926 22 liters.  The sequences for introducing the CNT powder into the mixer are the following: - 8 introductions, 6 minutes of mixing after each introduction - 5 introductions, 15 minutes of mixing after each introduction [0074] The piston goes down and then goes up in high position between each introduction of powder.  The speed of rotation of the mixer is between 20 rpm and 30 rpm.  The temperature of the mixture is about 100 ° C.  After the last powder introduction, the piston is lowered and then raised three times in order to optimize the mixing of the powder and the elastomer resin.  The speed of rotation of the mixer is increased until the temperature of the mixture is approximately equal to 150 ° C., and the mixer is then drained.  The composite material obtained undergoes several calendering steps until a homogeneous plate is obtained, easily handled, and simple and quick to cut.  The plate is analyzed under an optical microscope, and the image shown in Figure 5 is obtained.  At the macroscopic level, the plate is regular which implies a relatively homogeneous mixture of the powder and the elastomeric resin, and a satisfactory dispersion of said powder in said elastomeric resin.  Optical microscopy confirms this impression by the absence of NTC tasks.
    [0003] There is therefore a very good dispersion of the CNT powder in the elastomeric resin, and the resulting plate has good properties, in particular mechanical and electrical properties. These examples show the influence of the regulation of the introduction of the powder comprising CNTs, in particular the influence of the number of sequences for introducing said powder into the mixer. Ref: 0430-ARK54
    权利要求:
    Claims (19)
    [0001]
    REVENDICATIONS1. Mixing device (1) for the manufacture of a composite material from at least one powder comprising carbon nanofillers, and at least one elastomeric resin, characterized in that it comprises: - a mixer (2) for mixing the powder with the elastomeric resin, said mixer comprising a stack (5), a feed system (10) for introducing the powder into the mixer (2), said feeding system comprising a loading device (14) cooperating with a feed screw (11) opening into the mixer (2), - a piston (30) adapted to move in the chimney (5) of the mixer (2) and to contribute with said mixer to the mixture powder with the elastomeric resin.
    [0002]
    Mixing device for the manufacture of a composite material according to claim 1, characterized in that the loading device (14) comprises a container (18) connected to a double valve coupling device (19) ensuring the passage powder in the feed screw (11) securely.
    [0003]
    Mixing device for the manufacture of a composite material according to claims 1 and 2, characterized in that the coupling device (19) comprises an active valve (15) connected to the container (18) and a passive valve (16). ) connected to an inlet (110) for introducing the powder into the feed screw (11), the active valve and the passive valve being intended to be connected to allow the transfer of the powder from the container (18) into the feed screw (11).
    [0004]
    4. Mixing device for the manufacture of a composite material according to claim 1, characterized in that the feed screw (11) of the feed system (10) has a length / diameter ratio, said L / D ratio. ranging from 10 to 70, preferably from 20 to 70 and preferably from 40 to 60.
    [0005]
    5. Mixing device for the manufacture of a composite material according to any one of the preceding claims, characterized in that the mixer (2) Ref: 0430-ARK54 3029926 24 comprises a loading chamber (3) constituting the inlet of said mixer, the loading lock being connected to the feed screw (11), so that the powder enters directly into said lock (3) after the output of the feed screw, said mixer further comprising a chamber mixture (6) located under the loading chamber 5 (3) and capable of communicating with said airlock, said loading chamber (3) being surmounted by the chimney (5).
    [0006]
    6. Mixing device for the manufacture of a composite material according to claim 5, characterized in that the loading chamber (3) is provided with a tight sealing closure (4) separating said loading chamber from the chamber of 10 mixture (6).
    [0007]
    7. Mixing device for the manufacture of a composite material according to claim 5 or 6, characterized in that the loading chamber (3) comprises a door (50) allowing the introduction of the polymer resin into said airlock (3). ).
    [0008]
    8. Mixing device for the manufacture of a composite material according to any one of the preceding claims, characterized in that the mixer (2) comprises extraction means (23, 24, 25, 26) comprising prefilters and filters.
    [0009]
    9. A method of manufacturing a composite material comprising at least one powder comprising carbon nanofillers, and at least one elastomeric resin, said method being implemented by the mixing device (1) according to any one of the preceding claims. , characterized in that it comprises the following steps: a) Introduction of the elastomeric resin into the mixer (2), b) introduction of the powder into the mixer (2) via the feed system 25 (10) and control the feed rate by adjusting the speed of rotation of the feed screw (11), c) mixing the elastomer resin and the powder in the mixer (2) to obtain a composite material, d) Shaping of the composite material obtained in step c). Ref: 0430-ARK54 3029926 25
    [0010]
    10. A method of manufacturing a composite material according to claim 9, characterized in that the powder comprising carbon nanofillers comprises carbon nanotubes (CNTs) or nanofibers carbon or graphene, or carbon black, or a mixing said carbon nanofillers, or preferably carbon nanotubes alone or in combination with another nanofiller.
    [0011]
    11. A method of manufacturing a composite material according to claim 9 or 10, characterized in that the powder comprising carbon nanofillers, introduced into the mixer (2) further comprises at least one vulcanizing agent. 10
    [0012]
    12. A method of manufacturing a composite material according to claim 9 to 11, characterized in that the powder comprising carbon nanofillers introduced into the mixer (2) further comprises at least one additive.
    [0013]
    13. A method of manufacturing a composite material according to claims 9 to 12 characterized in that the amounts of elastomeric resin and powder introduced in steps a) and b) are such that they make it possible to obtain a composite material. during step c), the mass percentage of CNT of which is in the range of 1% to 60%, preferably greater than 10% in this range; preferably greater than 20%, and more preferably greater than 30%.
    [0014]
    14. A method of manufacturing a composite material according to claim 13, characterized in that the mass percentage of CNT in the composite material is less than 60%, preferably less than 50%, and more preferably less than 40%. %.
    [0015]
    15. A method of manufacturing a composite material according to claim 13 or 14, characterized in that the mass percentage of CNT in the composite material is between 30% and 40%.
    [0016]
    16. A method of manufacturing a composite material according to claim 9, characterized in that during step b), the powder is introduced into the mixer (2) sequentially, according to one or more introduction sequences d a volume of powder corresponding to a fraction of the total volume of powder to be introduced, each sequence comprising one or more powder introductions. Ref: 0430-ARK54 3029926 26
    [0017]
    17. A method of manufacturing a composite material according to claim 9, characterized in that the powder is introduced into the mixer (2) via the feed system (10) according to an integer n of sequences, each sequence comprising a integer number i of powder introductions, preferably n is between 1 and 5, and preferably between 2 and 3 and preferably, i is between 1 and 10, and advantageously between 4 and 8.
    [0018]
    18. A method of manufacturing a composite material according to claim 9, characterized in that it comprises, prior to step b), a step of mixing the elastomeric resin, then only in the mixer (2) during a between 1 minute and 15 minutes, preferably between 1 minute and 10 minutes, more preferably the mixing time of the elastomeric resin is 5 minutes and the mixing temperature of the elastomeric resin is in a range of from 40 ° C to 60 ° C.
    [0019]
    19. A method of manufacturing a composite material according to claim 9, characterized in that during steps b) and c) the temperature of the resin and powder mixture of carbonaceous nanofillers is from 40 ° C to 160 ° C, and preferably from 100 ° C to 150 ° C. Ref: 0430-ARK54
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    同族专利:
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    WO2016097544A1|2016-06-23|
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    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    US4022440A|1974-02-21|1977-05-10|Ikegai Iron Works, Ltd.|Method for producing plastic compound and an apparatus therefor|
    US5297865A|1990-09-05|1994-03-29|Werner & Pfleiderer Gummitechnik Gmbh|Method and apparatus for the mixing of mixing material with thermoplastic material|
    DE102007054549A1|2007-11-15|2009-05-20|Kleine Wood & Fibre Gmbh & Co. Kg|Producing natural fiber plastic composite material by drying the natural material such as hemp and/or wood in the form of fiber, shred or flour, crushing the wood raw materials and then compounding with a plastic melt and/or additives|
    US20110201731A1|2008-10-22|2011-08-18|Arkema France|Method for preparing a thermoplastic composite material containing nanotubes particularly carbon nanotubes|
    FR2967417A1|2010-11-17|2012-05-18|Arkema France|MASTER MIXTURE OF CARBON NANOTUBES AND HARDENER FOR THERMOSETTING RESINS|
    FR2991332A1|2012-06-04|2013-12-06|Arkema France|USE OF LOW-RATE CARBON NANOCHARGES FOR UV STABILIZATION OF COMPOSITE MATERIALS|
    FR2992321A1|2012-06-22|2013-12-27|Arkema France|METHOD FOR MANUFACTURING PRE-IMPREGNATED FIBROUS MATERIAL OF THERMOPLASTIC POLYMER|CN108972935A|2018-09-27|2018-12-11|吕银肖|Dispensing equipment is used in a kind of mixing of PVC micelle|EP1924631A4|2005-09-16|2012-03-07|Hyperion Catalysis Int|Conductive silicone and methods for preparing same|
    FR2927062B1|2008-02-04|2011-07-01|Arkema France|METHOD FOR SECURELY FILLING CARBON NANOTUBES, FILLING SYSTEM AND INDUSTRIAL PLANT USING THE METHOD|
    FR2943349B1|2009-03-23|2012-10-26|Arkema France|PROCESS FOR PREPARING ELASTOMERIC COMPOSITE MATERIAL HAVING HIGH NANOTUBE CONTENT|CN106584690B|2016-12-08|2019-04-26|江苏古柏包装科技有限公司|A kind of blister packaging raw material high-efficiency mixing device|
    CN108789909B|2017-04-28|2020-08-18|盐城申源塑胶有限公司|Internal mixer|
    CN109049386B|2018-08-23|2021-05-07|兰溪市旺兴塑胶制品有限公司|Ion type compounding banbury mixer|
    CN111421692B|2020-03-29|2022-02-01|太仓民翔特种无纺布有限公司|Gate driving control mechanism applied to gate system in non-woven fabric processing raw material feeding equipment|
    CN112677355A|2020-11-25|2021-04-20|杨富松|A compounding device for plastic granules processing|
    法律状态:
    2015-11-10| PLFP| Fee payment|Year of fee payment: 2 |
    2016-06-17| PLSC| Search report ready|Effective date: 20160617 |
    2016-11-11| PLFP| Fee payment|Year of fee payment: 3 |
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    2021-09-10| ST| Notification of lapse|Effective date: 20210806 |
    优先权:
    申请号 | 申请日 | 专利标题
    FR1462507A|FR3029926B1|2014-12-16|2014-12-16|MIXING DEVICE FOR THE MANUFACTURE OF A COMPOSITE MATERIAL FROM A POWDER COMPRISING CARBON NANOCHARGES AND AN ELASTOMERIC RESIN|
    FR1462507|2014-12-16|FR1462507A| FR3029926B1|2014-12-16|2014-12-16|MIXING DEVICE FOR THE MANUFACTURE OF A COMPOSITE MATERIAL FROM A POWDER COMPRISING CARBON NANOCHARGES AND AN ELASTOMERIC RESIN|
    PCT/FR2015/053415| WO2016097544A1|2014-12-16|2015-12-10|Mixing device for the manufacture of a composite material from a powder comprising carbon-based nanofillers and an elastomer resin|
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