Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L23/00—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers
  • C08L23/02—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers not modified by chemical after-treatment
  • C08L23/04—Homopolymers or copolymers of ethene
  • C08L23/08—Copolymers of ethene
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
  • B29C48/03—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor characterised by the shape of the extruded material at extrusion
  • B29C48/07—Flat, e.g. panels
  • B29C48/08—Flat, e.g. panels flexible, e.g. films
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
  • B29C48/25—Component parts, details or accessories; Auxiliary operations
  • B29C48/36—Means for plasticising or homogenising the moulding material or forcing it through the nozzle or die
  • B29C48/395—Means for plasticising or homogenising the moulding material or forcing it through the nozzle or die using screws surrounded by a cooperating barrel, e.g. single screw extruders
  • B29C48/40—Means for plasticising or homogenising the moulding material or forcing it through the nozzle or die using screws surrounded by a cooperating barrel, e.g. single screw extruders using two or more parallel screws or at least two parallel non-intermeshing screws, e.g. twin screw extruders
  • B29C48/405—Intermeshing co-rotating screws
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
  • B29C48/25—Component parts, details or accessories; Auxiliary operations
  • B29C48/36—Means for plasticising or homogenising the moulding material or forcing it through the nozzle or die
  • B29C48/50—Details of extruders
  • B29C48/505—Screws
  • B29C48/625—Screws characterised by the ratio of the threaded length of the screw to its outside diameter [L/D ratio]
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
  • B29C48/25—Component parts, details or accessories; Auxiliary operations
  • B29C48/88—Thermal treatment of the stream of extruded material, e.g. cooling
  • B29C48/918—Thermal treatment of the stream of extruded material, e.g. cooling characterized by differential heating or cooling
  • B29C48/9185—Thermal treatment of the stream of extruded material, e.g. cooling characterized by differential heating or cooling in the direction of the stream of the material
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
  • B29C48/25—Component parts, details or accessories; Auxiliary operations
  • B29C48/92—Measuring, controlling or regulating
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L23/00—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers
  • C08L23/02—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers not modified by chemical after-treatment
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C2948/00—Indexing scheme relating to extrusion moulding
  • B29C2948/92—Measuring, controlling or regulating
  • B29C2948/92009—Measured parameter
  • B29C2948/92019—Pressure
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C2948/00—Indexing scheme relating to extrusion moulding
  • B29C2948/92—Measuring, controlling or regulating
  • B29C2948/92323—Location or phase of measurement
  • B29C2948/92361—Extrusion unit
  • B29C2948/92409—Die; Nozzle zone
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C2948/00—Indexing scheme relating to extrusion moulding
  • B29C2948/92—Measuring, controlling or regulating
  • B29C2948/92504—Controlled parameter
  • B29C2948/92514—Pressure
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C2948/00—Indexing scheme relating to extrusion moulding
  • B29C2948/92—Measuring, controlling or regulating
  • B29C2948/92504—Controlled parameter
  • B29C2948/92704—Temperature
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C2948/00—Indexing scheme relating to extrusion moulding
  • B29C2948/92—Measuring, controlling or regulating
  • B29C2948/92819—Location or phase of control
  • B29C2948/92857—Extrusion unit
  • B29C2948/92876—Feeding, melting, plasticising or pumping zones, e.g. the melt itself
  • B29C2948/92895—Barrel or housing
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C2948/00—Indexing scheme relating to extrusion moulding
  • B29C2948/92—Measuring, controlling or regulating
  • B29C2948/92819—Location or phase of control
  • B29C2948/92857—Extrusion unit
  • B29C2948/92904—Die; Nozzle zone
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L2205/00—Polymer mixtures characterised by other features
  • C08L2205/14—Polymer mixtures characterised by other features containing polymeric additives characterised by shape
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L23/00—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers
  • C08L23/02—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers not modified by chemical after-treatment
  • C08L23/10—Homopolymers or copolymers of propene
  • C08L23/12—Polypropene
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L67/00—Compositions of polyesters obtained by reactions forming a carboxylic ester link in the main chain; Compositions of derivatives of such polymers
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L77/00—Compositions of polyamides obtained by reactions forming a carboxylic amide link in the main chain; Compositions of derivatives of such polymers

Definitions

• the present invention relates to a process for the preparation of polymer / polymer micro-composite materials by temperature-controlled extrusion, as well as the resulting micro-composite materials.
• polymer / polymer micro-composite material designates a material comprising a mixture of immiscible polymers, one of which forms a phase dispersed in the other constituting the matrix.
• the polymer / polymer micro-composite materials are generally prepared by extrusion at constant or substantially increasing temperature from the supply zone to the die, this extrusion step being followed by a drawing step and an outlet quenching before being implemented again for the intended applications.
• the materials thus obtained have a dispersed phase of nodular or fibrillar morphology oriented in the direction of stretching.
• thermomechanical properties of micro-composite materials available today are limited and insufficient for their subsequent processing.
• the objective of the present invention is to provide polymer / polymer microcomposite materials having a dispersed phase of semi-crystalline polymer type, and having improved thermomechanical properties.
• Another object of the invention is to provide a process for the preparation of the aforementioned micro-composite materials which can be implemented in a simple and reproducible manner with high contents in dispersed phase.
• the invention also aims to provide such a process for preparing micro-composite materials as indicated above with improved thermomechanical properties.
• Another objective of the present invention is to provide polymer / polymer micro-composite materials which can be used as starting materials for obtaining shaped objects retaining their thermomechanical properties.
• the invention relates to a polymer / polymer micro-composite material, comprising from 25 to 35% by weight of a semi-crystalline polymer (I) forming a dispersed phase localized within a thermoplastic or elastomeric polymer (II) forming a matrix, the crystallization temperature of the polymer (I) forming a dispersed phase being at least 20 ° C. higher than the melting or softening temperature of the polymer (II) forming a matrix, and the dispersed phase of said material specifically having a morphology such that it induces physical crosslinking of the continuous phase.
• the subject of the invention is also a process for the preparation of such composite materials, characterized in that it comprises the steps consisting in:
• control temperature being decreasing from the feed zone (A) to the die zone (F) of said extruder (1) so that the material temperature in said zone of the die (F) is lower than the recrystallization or solidification temperature of the polymer (I) and higher than the melting or softening temperature of the polymer (II);
• the invention also relates to a method for obtaining shaped objects, using, as starting material, a micro-material. composite as mentioned above at a controlled temperature such that, throughout the formation of said shaped object, the material temperature remains below the melting or softening temperature of the polymer forming the dispersed phase of the micro-composite material used.
• the inventors have demonstrated that by treating a mixture of polymers (or copolymers) chosen by a process called "dynamic quenching" as defined below, it was possible to obtain, in a reproducible and stable manner, micro-composite materials with a semi-crystalline dispersed phase having a threshold flow stress and having improved thermomechanical properties.
• FIGS. 2 and 3 are photographs taken with a scanning electron microscope, showing the morphology of materials obtained from an ethylene vinyl acetate (EVA) / polybutylene terephthalate (PBT) 70/30 mixture respectively by a traditional process and by the dynamic quenching method according to the invention;
• EVA ethylene vinyl acetate
• PBT polybutylene terephthalate
• FIG. 4 is a comparative diagram showing the variation curves of the complex shear modulus G 'and G "as a function of the stress frequency, in linear viscoelasticity, of the materials of Figures 2 and 3 obtained respectively according to a traditional process (G * : - ⁇ - ⁇ - and G ": -DD-), and according to the dynamic quenching method of the invention (G ': ⁇ and G”: D), Gp being the stress at the flow threshold;
• FIG. 5 is a comparative diagram showing the thermomechanical behavior (variation of the elastic modulus G 'as a function of the temperature) of the materials of Figures 2 and 3 obtained respectively according to a traditional process (u) and according to the dynamic quenching process of l invention (*) as well as that of EVA alone ( ⁇ ), at a stress frequency ⁇ equal to 1 rad / sec. ;
• a mixture is firstly produced comprising a polymer (I) intended to form a dispersed phase (called “polymer (I) forming dispersed phase”) and a polymer (II) intended to form the matrix (known as “polymer (II) forming matrix”).
• polymer denotes, without distinction, one or more polymers and / or copolymers.
• the polymers (I) and (II) used are specifically immiscible polymers.
• immiscible polymers polymers within the meaning of the invention, immiscible in the molten state, under the conditions of their use for the preparation of the desired materials, as well as in the final extruded material.
• the choice of polymers is made so that the crystallization or solidification temperature of the polymer (I) intended to form the dispersed phase is significantly higher than the melting or softening temperature of the polymer (II) forming the matrix.
• “clearly higher temperature” is meant a difference of at least 20 ° C between the temperatures considered, and preferably a difference ranging from 30 ° C to 50 ° C.
• a difference of the order of 30 ° C that is to say preferably between 25 and 40 ° C, and typically between 28 and 35 ° C, is more particularly preferred.
• the polymer (II) forming a matrix can be chosen from semi-crystalline or amorphous thermoplastic polymers, or also from elastomers.
• polymers suitable as polymer (II) forming a matrix mention may be made of polymers or copolymers of vinyl acetate and of acrylic esters, more particularly polymers or copolymers of ethylene / vinyl acetate or ethylene / acrylic esters .
• the matrix is an ethylene / vinyl acetate (EVA) polymer.
• EVA ethylene / vinyl acetate
• the polymer (I) forming a dispersed phase is itself a semi-crystalline polymer.
• the semi-crystalline polymers (I) suitable for the purposes of the invention there may be mentioned aromatic polyesters, polyamides, polyolefins or their mixtures.
• polyethylene terephthalate and polybutylene terephthalate polypropylene and polyethylene or their copolymers or their mixtures in all proportions.
• the process of the invention is specifically implemented in an extruder.
• Those skilled in the art are able to choose the characteristics of the extruder, in particular so as to relatively quickly obtain a homogeneous mixture by melt of the polymers, taking into account the physicochemical characteristics of the extruded material.
• the extruder used according to the invention is preferably a twin screw extruder, the length / diameter ratio of which is advantageously greater than or equal to 34.
• the speed of rotation of the screws as well as the rate of supply of polymers can be adapted by l he skilled in the art so as to limit self-heating and to satisfy the temperature condition explained below.
• the barrel of an extruder 1 is seen, for which the supply zone A, an intermediate zone I and the zone of the die F have been shown diagrammatically, subject respectively to regulation temperatures defined as explained. below.
• a die 3 is also placed at the outlet of the extruder.
• the mixture of polymers 2 is introduced into the feed zone A of the extruder 1.
• the control temperature T a is higher than the melting or softening temperature of each of the polymers in the mixture.
• the polymers are then quickly melt-mixed so that the polymer forming the minority phase is dispersed homogeneously in the other polymer.
• the regulation temperature corresponds to the temperature applied (set temperature) to the barrel of the extruder and takes account in particular of thermal phenomena can intervene in the installation and the self-heating of the treated material which can occur during the extrusion operation.
• the choice of the regulation temperature depends on the polymers used.
• the extrusion operation is continued on the polymer blend in the molten state up to the zone of the die F where it will undergo a “dynamic quenching”.
• dynamic quenching designates a controlled cooling operation carried out in the extruder, upstream of the die, causing recrystallization or solidification of the polymer (I) forming a dispersed phase in the polymer (II) forming a matrix, under the shear forces and mechanical stresses imposed by the extruder (screw rotation).
• the regulation temperature T fil in the zone of the die F is fixed so that the temperature of the material located in this zone is lower than the recrystallization or solidification temperature of the polymer (I) intended to form the dispersed phase.
• the regulation temperature T fi is advantageously at least 20 ° C lower than the recrystallization or solidification temperature of the polymer (I), and it is preferably 30 ° C to 50 ° C below this temperature.
• the temperature in the zone of the die F is thus significantly lower than the temperature of the supply zone A and therefore follows a decreasing profile between said zones passing through an intermediate zone I where the temperature
• Ti is lower than that of zone A but does not yet correspond to the "dynamic quenching" temperature.
• the material is simply cooled to ambient temperature.
• the process of the invention generally leads to the production of micro-composite materials where the dispersed phase has a specific morphology, called of the coral type, that is to say that it is generally in the form of microstructures discontinuous dispersed within the material and having multiple and irregular ramifications.
• a microstructure of the "coral" type in FIG. 3 which, by comparison with FIG. 2, illustrates the difference in morphology obtained according to the "dynamic quenching" method of the invention and according to a method traditional.
• the quenching operation is carried out after the extrusion step, and independently, whereby we obtain a morphology of the type of the nodular morphology of FIG. 2.
• the average size of the polymer microstructures (I) present in the dispersed phase is generally of the order of 1 to 5 ⁇ m. In particular in the case of microstructures of the “coral pieces” type, it is preferred that this size is of the order of a micron.
• the concentration of polymer (I) forming a dispersed phase is specifically between 25% and 35% by weight (that is to say between 19% and 28% by volume) relative to the all polymers.
• this content is less than 35% by weight, and advantageously less than or equal to 33% by weight.
• this content is greater than 25% by weight, and advantageously greater than or equal to 27% by weight.
• this concentration is advantageously of the order of 30% by weight (22% by volume), and it can thus typically be between 28 and 32% by weight.
• the particular morphology obtained for the dispersed phase in particular when it is a "coral" type morphology, induces within the micro-composite materials of the invention a strengthening effect by physical crosslinking.
• physical crosslinking within the meaning of the invention, is meant a mechanical type joining of the dispersed phase and the continuous phase, which leads to a structuring of the continuous phase (and therefore, overall, of the material) by the dispersed phase. It should be emphasized that the physical crosslinking of the materials of the invention is in particular to be distinguished from the chemical type crosslinking used in other polymer / polymer composite materials known from the prior art, in which a crosslinking of the phases by creation of chemical bonds, for example by adding a crosslinking agent or by treatment under irradiation.
• the nature of the physical “crosslinking” of the materials of the invention due to the particular morphology of the dispersed phase, which secures the microstructures of the dispersed phase with the continuous phase, is radically different from a chemical crosslinking.
• the structuring, of a mechanical nature, which characterizes the materials of the invention does not freeze the configuration of the material definitively as in the case of chemical crosslinking.
• the physical crosslinking of the composite materials of the invention makes it possible in particular to substantially reduce the creep phenomena of these materials at temperatures above the melting or softening temperature of the matrix.
• the materials obtained according to the process of the invention exhibit characteristic rheological properties, with in particular the existence of a threshold flow stress (denoted G p ) which is defined as being the value of the shear modulus elastic (G ') at equilibrium; Gp represents the limit of G 'function of ⁇ [G' ( ⁇ )] when ⁇ tends to 0.
• G p represents the limit of G 'function of ⁇ [G' ( ⁇ )] when ⁇ tends to 0.
• the materials obtained according to the process of the invention therefore constitute interesting intermediate products which can serve as starting materials for the preparation of shaped articles.
• they can be put implemented according to various techniques, chosen according to the shaped object that one wishes to obtain.
• the methods of making shaped articles using the micro-composite materials of the invention as starting materials can thus consist, for example, of one or more extrusion, injection, and / or molding operations. .
• the processing temperature of the microcomposite materials according to the invention (that is to say the material temperature) must remain below the melting temperature or softening of the polymer (I) forming the dispersed phase.
• the processing temperature of the materials of the invention (material temperature) remains at least 20 ° C, and more preferably from 30 ° C to 50 ° C, to the melting temperature or softening of the polymer (I) forming the dispersed phase.
• the sheath has nine successive and independent parts for regulating the temperature determining three zones, the supply zone A, the intermediate zone I and the zone of the die F, shown diagrammatically in FIG. 1.
• heating zones are also equipped with a pressurized water circuit, controlled by solenoid valve allowing the evacuation of calories. produced by viscous dissipation of polymers which is introduced by the mechanical shearing of screws. This system considerably limits self-heating phenomena.
• the different heating zones of the sheath are illustrated in FIG. 1.
• the sector is also regulated independently of the other zones but does not have a water regulation system. For the entire process described, the speed of rotation of the screws is fixed at
• the two polymers (polymer forming matrix and polymer forming dispersed phase) are introduced together into the feed zone A of the extruder.
• the polymer material temperature is controlled by two infrared (IR) temperature sensors. These sensors measure and control the actual temperature of the molten polymers. They are located in the intermediate zone l 4 and at the top of the die 3. A pressure sensor makes it possible to measure and control the pressure at the inlet of the die 3.
• IR infrared
• test specimens are of the H3 type according to standard NF T51-034.
• test conditions are as follows:
• the threshold flow stress is measured at 120 ° C.
• the temperature range of use of the material is defined as being the region where the material does not flow for applied stresses lower than the critical stress Gp (flow threshold). Temperature of use, defined according to this threshold stress criterion, must therefore be lower than the melting or softening temperature of the dispersed phase.
• the matrix consists of a copolymer of ethylene and vinyl acetate containing 28% by weight of vinyl acetate. It is an Atochem copolymer of commercial reference Evatane 2803. Its melting point is 80 ° C. and its crystallization temperature is close to 50 ° C.
• the dispersed phase is formed from polybutylene terephthalate (PBT), a Dupont polymer of Crastin commercial reference. Its melting point is 225 ° C and its crystallization point is 205 ° C. 30% by weight of PBT are dispersed according to the method of the invention in the EVA matrix.
• PBT polybutylene terephthalate
• a new morphology of the PBT phase is obtained, giving the composite material a reinforcing effect making it possible to considerably reduce the creep phenomenon of the material at temperatures above the melting temperature of the EVA matrix.
• FIG. 5 shows that the mixture retains all of its thermomechanical properties of physical cross-linking (zero creep for stresses of sample stresses less than Gp) as long as the application temperature of the material does not exceed 225 ° C. which is the temperature PBT merger.
• Figure 5 shows the thermomechanical behavior of materials for a stress frequency ⁇ equal to 1 rad / s.
• thermomechanical properties measured are compared in table 3 to the reference samples obtained by a conventional process of implementation on the same extruder (identical speed and speed of the screws).
• EXAMPLE 2 EVA / PET composite.
• the matrix consists of a copolymer of ethylene and vinyl acetate containing 28% by weight of vinyl acetate. This copolymer is the same as that used in Example 1.
• the dispersed phase is formed from polyethylene terephthalate (PET), an Eastman polymer of commercial reference Eastapak PET, Copolyester 9921. Its melting temperature is 240 ° C and its crystallization temperature is 220 ° C.
• 30% by weight of PET are dispersed according to the method of the invention in the EVA matrix.
• thermomechanical properties measured are compared in Table 6 to the reference samples obtained by a conventional process of implementation on the same extruder (identical speed and speed of the screws).
• the matrix consists of a copolymer of ethylene and vinyl acetate containing 28% by weight of vinyl acetate. This copolymer is the same as that used in Examples 1 and 2.
• the dispersed phase is formed from polypropylene (PP), an Appryl semi-crystalline polymer of commercial reference Appryl 3120. Its melting temperature is 165 ° C and its crystallization temperature is 135 ° C.
• 30% by weight of PP are dispersed according to the method of the invention in the EVA matrix.
• thermomechanical properties measured are compared in table 9 to the reference samples obtained by a conventional process of implementation on the same extruder (identical speed and speed of the screws).
• the matrix consists of a copolymer of ethylene and vinyl acetate containing 40% by weight of vinyl acetate.
• This copolymer is an Atochem product of commercial reference Evatane 4055. Its melting point is 40 ° C. and its crystallization point is 25 ° C.
• the dispersed phase consists of polypropylene (PP) identical to the PP used in Example 3.
• 25% by weight of PP are dispersed according to the method of the invention in the EVA matrix.
• thermomechanical properties measured are compared in table 12 with the reference samples obtained by a conventional process of implementation on the same extruder (identical speed and speed of the screws).
• the matrix consists of a copolymer of ethylene and octene.
• This copolymer is a Dupont Low Elastomers product of commercial reference Engage 8100.
• This copolymer is an elastomer whose melting temperature is 60 ° C.
• the dispersed phase of the invention consists of polypropylene (PP) identical to the PP used in Examples 3 and 4.
• 30% by weight are dispersed according to the method of the invention in the EVA matrix.
• thermomechanical properties measured are compared in table 15 to the reference samples obtained by a conventional process of implementation on the same extruder (identical speed and speed of the screws).

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Extrusion Moulding Of Plastics Or The Like (AREA)
• Compositions Of Macromolecular Compounds (AREA)
• Processes Of Treating Macromolecular Substances (AREA)
• Processing And Handling Of Plastics And Other Materials For Molding In General (AREA)
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• 2000
  • 2000-04-06 FR FR0004420A patent/FR2807440A1/fr not_active Withdrawn
• 2001
  • 2001-04-06 US US10/240,939 patent/US20030166778A1/en not_active Abandoned
  • 2001-04-06 AU AU2001248492A patent/AU2001248492A1/en not_active Abandoned
  • 2001-04-06 WO PCT/FR2001/001056 patent/WO2001077222A1/fr not_active Application Discontinuation
  • 2001-04-06 EP EP01923758A patent/EP1272558A1/de not_active Withdrawn
  • 2001-04-06 US US10/240,933 patent/US20030181596A1/en not_active Abandoned
  • 2001-04-06 CA CA002405111A patent/CA2405111A1/fr not_active Abandoned
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