Classifications

• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D11/00—Inks
  • C09D11/02—Printing inks
  • C09D11/10—Printing inks based on artificial resins
  • C09D11/106—Printing inks based on artificial resins containing macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D11/00—Inks
  • C09D11/02—Printing inks
  • C09D11/03—Printing inks characterised by features other than the chemical nature of the binder
  • C09D11/033—Printing inks characterised by features other than the chemical nature of the binder characterised by the solvent
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D127/00—Coating compositions based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Coating compositions based on derivatives of such polymers
  • C09D127/02—Coating compositions based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Coating compositions based on derivatives of such polymers not modified by chemical after-treatment
  • C09D127/12—Coating compositions based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Coating compositions based on derivatives of such polymers not modified by chemical after-treatment containing fluorine atoms
  • C09D127/16—Homopolymers or copolymers of vinylidene fluoride

Definitions

• the present invention relates in particular to a fluoropolymer ink comprising a ketone vehicle and exhibiting a rheological behavior of fluid at a stress threshold, the use of such an ink for the manufacture of polymer films and electronic devices, as well as a method for preparing such an ink.
• Fluoropolymers such as polyvinylidene fluoride (PVDF) and copolymers derived therefrom have a large number of uses, in particular in which they are deposited in the form of a film on a substrate.
• PVDF polyvinylidene fluoride
• electroactive copolymers based on vinylidene fluoride (VDF) and trifluoroethylene (TrFE), which may optionally contain a third monomer such as chlorotrifluoroethylene (CTFE) or 1, 1 -chlorofluoroethylene (CFE).
• CFE chlorotrifluoroethylene
• HFP hexafluoropropene
• the deposition of such fluoropolymers in the form of a film can be carried out from a formulation called "ink", formed by mixing fluoropolymer, and optionally additives, in a vehicle.
• the ink When depositing these inks on a substrate, in particular by printing techniques, it may be necessary for the ink to adopt a specific rheological behavior in order to obtain a good quality of deposit. More particularly, the rheological behavior of the string type (Newtonian or rheofluidifier with Newtonian plate) may be undesirable for certain printing processes, such as that of screen printing. Indeed, the use of a solution with stringing behavior in screen printing can lead lower productivity, clogging of masks or poorer definition of printed patterns than with paste type ink with a stress threshold.
• the string type Newtonian plate
• the ink obtained often has a Newtonian rheological or shear thinning behavior with Newtonian plateau (depending on the molar mass and the concentration of the polymer considered).
• compositions with rheological behavior at stress threshold from shooting compositions one possibility consists in adding finely divided particles of silica, calcium carbonate or the like, or polymeric rheological additives such as crosslinked polymer particles which do not dissolve perfectly in the composition, but which tend to swell in the composition, in contrast to polymer chains well dissolved in the medium.
• the presence in an ink of these rheological additives can be detrimental because it can degrade the final properties of the polymer films obtained.
• the films prepared from fluoropolymer inks comprising such additives may have lower (for example electro-active) properties, by simple dilution effect, or even because of negative synergies or disturbing effects provided by the additives. rheological.
• the invention relates firstly to an ink exhibiting a rheological behavior of fluid at stress threshold comprising a fluoropolymer and a liquid vehicle comprising a compound of formula (I):
• R-i, R2 and R3 each independently represent a C1 or C2 alkyl group and / or n is 1 or 2.
• the compound of formula (I) is diacetone alcohol.
• the fluoropolymer is chosen from poly (vinylidene fluoride-co-hexafluoropropene), poly (vinylidene fluoride-co-trifluoroethylene), poly (vinylidene fluoride-ter-trifluoroethylene-ter-chlorotrifluoroethylene) and poly (vinylidene fluoride-ter-trifluoroethylene-ter-1, 1-chlorofluoroethylene).
• the ink comprises from 0.1 to 60%, preferably from 0.5 to 30%, more preferably from 1 to 25%, even more preferably from 3 to 20%, even more preferably from 8 at 18%, even more preferably from 10 to 14%, by weight of the fluoropolymer, relative to the total weight of the ink.
• the ink does not include rheological additives such as silica or calcium carbonate particles, or crosslinked polymer particles and / or surfactants.
• the liquid vehicle essentially consists of the compound of formula (I).
• the invention also relates to a method for preparing an ink as described above, comprising the dispersion of the fluoropolymer in a liquid vehicle comprising the compound of formula (I).
• the dispersion is carried out at a target temperature so as to directly obtain a rheological behavior at stress threshold.
• the dispersion is carried out at a first temperature, the method further comprising reducing the temperature of the ink to a target temperature, so as to obtain a rheological behavior at a stress threshold.
• the target temperature is from 0 to 60 ° C, preferably from 5 to 55 ° C.
• the target temperature is applied for a duration greater than or equal to one minute, preferably greater than or equal to one hour.
• the invention also relates to a process for manufacturing a fluoropolymer film or an electronic device comprising:
• the method further comprises, before the deposition step, a step of applying a target temperature to an ink comprising a fluoropolymer and a liquid vehicle comprising a compound of formula (I), so as to obtain a rheological behavior with a stress threshold.
• the deposition of the ink is carried out by printing, in particular by screen printing, by roller printing, by flexography printing, by lithography printing, preferably by screen printing.
• the present invention makes it possible to meet the need expressed above. It more particularly provides a fluoropolymer ink which is well suited to printing techniques and in particular to screen printing since it exhibits a rheological behavior of the fluid at a stress threshold, while not requiring the addition of undesirable rheological additives.
• the ink according to the invention thus makes it possible to obtain polymer films of superior quality.
• the invention also has one or preferably several of the advantageous characteristics listed below.
• the ink is transparent
• the ink is easily prepared and / or used.
• FIG. 1 represents the flow curves obtained by an Anton Paar PHYSICA MCR 301 rheometer for the ink of FC-20 copolymer at 14% by weight in diacetone alcohol during the initial measurement at 40 ° C. as described in FIG. Example 2, comprising a series of three scans in shear rate from 1000 to 0.1 s -1 , from 0.1 to 1000 s -1 then from 1000 to 0.1 s -1 .
• the abscissa axis represents the applied shear rate (in s -1 ) on a logarithmic scale and the ordinate axis represents the dynamic viscosity of the ink tested (in Pa.s) on a logarithmic scale.
• FIG. 2 represents the flow curves obtained by an Anton Paar PHYSICA MCR 301 rheometer for the ink of FC-20 copolymer at 14% by weight in diacetone alcohol during the measurement at 40 ° C. at approximately 27 min (measurement n ° 3) as described in example 2, comprising a series of three scans in shear rate from 1000 to 0.1 s -1 (curve a), from 0.1 to 1000 s -1 (curve b) then from 1000 to 0.1 s -1 (curve c).
• the abscissa axis represents the applied shear rate (in s -1 ) on a logarithmic scale and the ordinate axis represents the dynamic viscosity of the ink tested (in Pa.s) on a logarithmic scale.
• FIG. 3 represents the flow curves obtained by an Anton Paar PHYSICA MCR 301 rheometer for the FC-20 copolymer ink at 14% by weight in diacetone alcohol during the measurement at 40 ° C. at approximately 40 min (measurement n ° 4), as described in example 2, comprising a series of three sweeps in shear rate from 1000 to 0.1 s -1 , from 0.1 to 1000 s -1 then from 1000 to 0.1 s -1 .
• the abscissa axis represents the applied shear rate (in s -1 ) on a logarithmic scale and the ordinate axis represents the dynamic viscosity of the ink tested (in Pa.s) on a logarithmic scale.
• FIG. 4 represents the flow curves obtained by an Anton Paar PHYSICA MCR 301 rheometer for the FC-20 copolymer ink at 14% by weight in diacetone alcohol during the measurement at 40 ° C. at approximately 67 min (measurement n ° 6), as described in example 2, comprising a series of three sweeps in shear rate from 1000 to 0.1 s -1 , from 0.1 to 1000 s -1 then from 1000 to 0.1 s -1 .
• the abscissa axis represents the applied shear rate (in s -1 ) on a logarithmic scale and the ordinate axis represents the dynamic viscosity of the ink tested (in Pa.s) on a logarithmic scale.
• FIG. 5 represents the flow curves obtained by an Anton Paar PHYSICA MCR 301 rheometer for the ink of FC-20 copolymer at 14% by weight in diacetone alcohol (set of curves A) and for the ink of FC copolymer -20 to 12% by weight in the diacetone alcohol (set of curves B) of the measurements at 40 ° C. as described in Example 3, each measurement comprising a series of three scans in shear rate from 1000 to 0.1 s -1 , from 0.1 to 1000 s -1 then from 1000 to 0.1 s -1 .
• the abscissa axis represents the applied shear rate (in s -1 ) on a logarithmic scale and the ordinate axis represents the dynamic viscosity of the inks tested (in Pa.s) on a logarithmic scale.
• FIG. 6 represents the flow curves obtained by an Anton Paar PHYSICA MCR 301 rheometer for the FC-20 copolymer ink at 14% by weight in diacetone alcohol during the measurement at 40 ° C. (set of curves C) and measurement at 30 ° C (set of curves D), as described in Example 4, each measurement comprising a series of three sweeps in shear rate from 1000 to 0.1 s -1 , from 0.1 at 1000 s -1 then from 1000 to 0.1 s -1 .
• the abscissa axis represents the applied shear rate (in s -1 ) on a logarithmic scale and the ordinate axis represents the dynamic viscosity of the ink tested (in Pa.s) on a logarithmic scale.
• FIG. 7 represents the flow curves obtained by an Anton Paar PHYSICA MCR 301 rheometer for the ink of FC-20 copolymer at 14% by weight in diacetone alcohol, after elongation deformation, during the measurement at 40 ° C. as described in example 5, comprising a series of three sweeps in shear rate from 1000 to 0.1 s -1 , from 0.1 to 1000 s -1 then from 1000 to 0.1 s -1 .
• the abscissa axis represents the applied shear rate (in s -1 ) on a logarithmic scale and the ordinate axis represents the dynamic viscosity of the ink tested (in Pa.s) on a logarithmic scale.
• stress threshold fluid means a fluid flowing only from a certain value of shear stress applied to the fluid (called “threshold stress”).
• a fluid with a stress threshold is a fluid for which, when we represent in a graph the logarithm of the dynamic viscosity of the fluid as a function of the logarithm of the applied shear rate, for example using of a rheometer in cone-plane configuration, at the ink temperature, no Newtonian plateau (or plateau) is observed at low shear rates, that is to say in the range of shear rates between 0.1 and 10 s -1 .
• Newtonian plateau (or plateau) is meant a horizontal or essentially horizontal line, that is to say that the logarithm of the viscosity is essentially constant over this range of shear rate.
• a stress threshold fluid can be characterized by a ratio between the dynamic viscosity value at a shear rate of 0.1 s -1 and the dynamic viscosity value at a shear rate of 10 s - 1 greater than or equal to 2, preferably greater than or equal to 5, more preferably still greater than or equal to 10, and more preferably still greater than or equal to 20, at the temperature of the ink.
• the measurement is for example carried out with an Anton Paar PHYSICA MCR 301 rheometer in cone-plane configuration.
• This ink includes a fluoropolymer.
• the fluoropolymer is preferably a carbon chain polymer which comprises structural units (or units, or repeating units, or units) comprising at least one fluorine atom.
• the fluoropolymer comprises units derived from (that is to say which are obtained by polymerization of) vinylidene fluoride (VDF) monomers.
• VDF vinylidene fluoride
• the fluoropolymer is a PVDF homopolymer.
• the fluoropolymer is a copolymer (in the broad sense), that is to say that it comprises units derived from at least one other monomer X than VDF.
• a single X monomer can be used, or several different X monomers, depending on the case.
• each group X1, X2, X3 and X 4 independently represents an atom F1, F, Cl, I or Br, or a methyl group optionally comprising one or more substituents chosen from F, Cl, I and Br.
• each group X1, X2, X3 and X 4 independently represents a Fl, F, Cl, I or Br atom.
• only one of X1, X2, X3 and X 4 represents a Cl or I or Br atom, and the others of groups X1, X2, X3 and X 4 independently represent: a Fl or F atom or a group C1 -C3 alkyl optionally comprising one or more fluorine substituents; preferably an F1 or F atom or a C1 -C2 alkyl group optionally comprising one or more fluorine substituents; and more preferably, an F1 or F atom or a methyl group optionally comprising one or more fluorine substituents.
• the monomer X comprises a chlorine or bromine atom. It can in particular be chosen from bromotrifluoroethylene, chlorofluoroethylene, chlorotrifluoroethylene and chlorotrifluoropropene.
• Chlorofluoroethylene can denote either 1-chloro-1-fluoroethylene or 1-chloro-2-fluoroethylene.
• the 1-chloro-1-fluoroethylene (CFE) isomer is preferred.
• the chlorotrifluoropropene is preferably 1-chloro-3,3,3-trifluoropropene (in iso or trans form, preferably trans) or 2-chloro-3,3,3-trifluoropropene.
• the fluoropolymer comprises units derived from VDF and HFP, or else is a polymer P (VDF-HFP) consisting of units derived from VDF and HFP.
• the molar proportion of repeat units originating from HFP is preferably from 2 to 50%, in particular from 5 to 40%.
• the fluoropolymer comprises units derived from VDF and CFE, or from CTFE, or from TFE, or from TrFE.
• the molar proportion of repeat units originating from the monomers other than VDF is preferably less than 50%, more preferably less than 40%.
• the fluoropolymer comprises units derived from VDF and TrFE, or else is a polymer P (VDF-TrFE) consisting of units derived from VDF and TrFE.
• the fluoropolymer comprises units derived from VDF, TrFE and another monomer X as defined above, different from VDF and TrFE, or else is a polymer P (VDF-TrFE -X) consisting of units derived from VDF, TrFE and another monomer X as defined above, different from VDF and TrFE.
• the other monomer X is chosen from TFE, HFP, trifluoropropenes and in particular 3,3,3-trifluoropropene, tetrafluoropropenes and in particular 2,3,3,3-tetrafluoropropene or 1, 3,3,3- tetrafluoropropene (in single or preferably trans form), the bromotrifluoroethylene, chlorofluoroethylene, chlorotrifluoroethylene and chlorotrifluoropropene.
• CTFE or CFE are particularly preferred.
• the proportion of units from TrFE is preferably from 5 to 95 mol.% Relative to the sum of the units from VDF and T rFE, and in particular: from 5 at 10 mol.%; or from 10 to 15 mol.%; or from 15 to 20 mol.%; or from 20 to 25 mol.%; or from 25 to 30 mol.%; or from 30 to 35 mol.%; or from 35 to 40 mol.%; or from 40 to 45 mol.%; or from 45 to 50 mol.%; or from 50 to 55 mol.%; or from 55 to 60 mol.%; or from 60 to 65 mol.%; or from 65 to 70 mol.%; or from 70 to 75 mol.%; or from 75 to 80 mol.%; or from 80 to 85 mol.%; or from 85 to 90 mol.%; or from 90 to 95 mol.%.
• a range of 15 to 55 mol.% Is particularly preferred.
• the proportion of units from this other X monomer in the fluorinated polymer can vary for example from 0.5 to 1 mol.%; or from 1 to 2 mol.%; or from 2 to 3 mol.%; or from 3 to 4 mol.%; or from 4 to 5 mol.%; or from 5 to 6 mol.%; or from 6 to 7 mol.%; or from 7 to 8 mol.%; or from 8 to 9 mol.%; or from 9 to 10 mol.%; or from 10 to 12 mol.%; or from 12 to 15 mol.%; or from 15 to 20 mol.%; or from 20 to 25 mol.%; or from 25 to 30 mol.%; or from 30 to 40 mol.%; or from 40 to 50 mol.%. Ranges from 1 to 20 mol.%, And preferably from 2 to
• the molar composition of the units in the fluoropolymers can be determined by various means such as infrared spectroscopy or RAMAN spectroscopy.
• Multicore NMR techniques in particular proton (1 H) and fluorine (19F), can also be used by analysis of a solution of the polymer in an appropriate deuterated solvent.
• the viscosity of the fluoropolymer is preferably from 0.1 to 100 kPo (kiloPoises) by carrying out a measurement at 230 ° C and at 100 s -1 of rate of shear (according to ASTM D4440, using a PHYSICA MCR301 device equipped with two parallel plates).
• the fluoropolymer is preferably random and linear.
• the fluoropolymer can be homogeneous or heterogeneous.
• a homogeneous polymer has a uniform chain structure, the statistical distribution of the units from the different monomers practically not varying between the chains.
• the chains In a heterogeneous polymer, the chains have a distribution in units derived from the various monomers of multimodal or spread type.
• a heterogeneous polymer therefore comprises chains richer in a given unit and chains poorer in this unit.
• the ink according to the invention also comprises a liquid vehicle comprising a compound of formula (I):
• n is an integer ranging from 1 to 3 and R1, R2 and R3 each independently represent a C1 to C3 alkyl group.
• the vehicle for an ink may be a solvent for one or more polymers of the ink, that is to say a liquid capable of dissolving said polymer to form a true solution (i.e. - say single-phase or homogeneous at the molecular level), or a non-solvent for one or more polymers, that is to say a liquid in which said polymer is not capable of dissolving completely, or a mixture of those -this.
• the ink according to the invention is preferably a homogeneous liquid dispersion.
• homogeneous dispersion is meant a dispersion of polymer particles, more or less swollen from the vehicle, in a continuous vehicle phase.
• the homogeneity of the dispersion is thus a macroscopic homogeneity (that is to say that by observing it with the naked eye the dispersion is of homogeneous appearance), characterized in that the dispersion does not have any granular or macro-separated appearance.
• the term “homogeneous dispersion” is thus used in opposition to a “heterogeneous dispersion”, that is to say a dispersion with a macroscopic appearance partially granular or having a macroscopically visible phase separation.
• n 1 or 2.
• each group Ri, R2 and R3 independently represents a C1 or C2 alkyl group.
• the compound of formula (I) is diacetone alcohol. Diacetone alcohol has the advantage of being a low volatile solvent, which improves the stability of the ink.
• the ink may contain from 0.1 to 60%, preferably from 0.5 to 30%, more preferably from 1 to 25%, more preferably from 3 to 20%, more preferably from 8 to 18%, more preferably from 10 to 14% by weight of polymer, relative to the total weight of the ink.
• the polymer may consist of the above fluoropolymer, or may include said fluoropolymer and one or more additional polymers.
• the ink preferably comprises from 0.1 to 60%, more preferably from 0.5 to 30%, more preferably from 1 to 25%, even more preferably from 3 to 20%, by weight of the fluoropolymer, relative to the total weight of the ink.
• the ink comprises from 30 to 99.9% by weight of compound of formula (I), and in particular from 30 to 40%, or from 40 to 50%, or from 50 to 60%, or from 60 to 70%, or 70 to 80%, or 80 to 90%, or 90 to 99.9%, by weight, of compound of formula (I), relative to the total weight of the ink.
• the liquid vehicle can also comprise one or more other substances liquid at room temperature, which can be solvents or non-solvents for the fluoropolymer, and which can in particular be chosen from alcohols, ethers, halogenated vehicles, alkanes, cycloalkanes , aromatic vehicles, ketones, aldehydes, esters, including cyclic esters, carbonates, phosphates, furans, amides and sulfoxides, and combinations thereof.
• solvents or non-solvents for the fluoropolymer can in particular be chosen from alcohols, ethers, halogenated vehicles, alkanes, cycloalkanes , aromatic vehicles, ketones, aldehydes, esters, including cyclic esters, carbonates, phosphates, furans, amides and sulfoxides, and combinations thereof.
• the various substances constituting the liquid vehicle are miscible.
• miscible is meant capable of mixing to form, in the absence of the polymer, a homogeneous mixture at the molecular level and preferably transparent, without any trace of separation of liquid / liquid phases.
• solvent it is possible in particular to use a substance chosen from the group consisting of ketones, esters, in particular cyclic esters, dimethylsulfoxide, phosphoric esters such as triethyl phosphate, carbonates, ethers such as tetrahydrofuran, and a mixture of these.
• Low volatility solvents are particularly preferred, and in particular gamma-butyrolactone, triethyl phosphate, cyclopentanone, monomethyl ether acetate propylene glycol.
• Low volatility solvents allow greater ink stability.
• volatile solvents can also be used, in particular the methyl ethyl ketone or ethyl acetate. The latter has the advantage of having a favorable ecotoxicological profile.
• the solvent for the fluoropolymer may be a mixture of two or more of the above solvents.
• non-solvent it is possible, for example, to use benzyl alcohol, benzaldehyde, or a mixture of these. These non-solvents offer both the advantage of being low volatility, which makes it possible to maintain good ink stability, and the advantage of having a favorable ecotoxicological profile (non-solvents called "green").
• the compound of formula (I) is present, relative to the total of the liquid vehicle of the ink, in a mass quantity greater than or equal to 50%, preferably greater than or equal to 70%, of preferably still greater than or equal to 90%.
• the liquid vehicle of the ink essentially consists of the compound of formula (I), that is to say that the compound of formula (I) is present, relative to the total of the liquid vehicle of the ink, in a mass quantity greater than or equal to 95%, more preferably greater than or equal to 98%, even more preferably greater than or equal to 99%, even more preferably greater than or equal to 99.5%, even more preferably greater than or equal 99.9%.
• the compound of formula (I) is the only liquid vehicle of ink, that is to say that the liquid vehicle of ink consists of the compound of formula (I).
• the ink may optionally comprise one or more additives, in particular chosen from rheology modifying agents, agents modifying aging resistance, agents modifying adhesion, pigments or dyes, fillers (including nanofillers). ).
• the ink may also contain one or more additives used for the synthesis of the polymer (s).
• the ink does not comprise rheology modifying agents (also called “rheological additives”), in particular the silica particles, the calcium carbonate particles, and / or the crosslinked polymer particles.
• rheological additives also called “rheological additives”
• the ink does not include agents that modify surface or interfacial tension, such as surfactants.
• the ink comprises at least one additive for crosslinking aid preferably chosen from radical initiators, photoinitiators, co-agents such as of bifunctional or polyfunctional molecules in terms of reactive double bonds, basic cross-linking agents such as di-amines, and combinations thereof.
• additive for crosslinking aid preferably chosen from radical initiators, photoinitiators, co-agents such as of bifunctional or polyfunctional molecules in terms of reactive double bonds, basic cross-linking agents such as di-amines, and combinations thereof.
• no crosslinking aid additive such as a photoinitiator or a crosslinking agent, is present in the ink.
• the total content of additives is preferably less than 20% by weight, more preferably less than 10% by weight, relative to the total of the polymers and additives.
• the ink preferably has a non-volatile dry matter content of 0.1 to 60%, preferably of 0.5 to 30%, more preferably of 1 to 25%, more preferably of 3 to 20%, of more preferably 8 to 18%, more preferably 10 to 14% by weight.
• the ink according to the invention is transparent.
• the invention also relates to a method for preparing an ink as described above.
• the ink can be prepared by dispersing the fluoropolymer (and optionally the other polymers) in the vehicle comprising the compound of formula (I), and preferably by mixing.
• additives When additives must be added to form the ink according to the invention, they can be added before, during or after the dispersion of the polymers in the liquid vehicle.
• the preparation is carried out with moderate stirring.
• the inks of fluoropolymers in a vehicle comprising a compound of formula (I) could have three possible states.
• a solution that is to say a homogeneous dispersion of the polymer in the vehicle at the molecular level
• a rheological behavior of Newtonian type followed by a behavior of rheofluidifier type (typical state of solutions of fluoropolymer in a good solvent)
• two other states can appear over time, especially if the ink temperature is low enough.
• the solution can first become a paste of creamy consistency with rheological behavior of the fluid type with stress threshold.
• the paste can change state and pass in the form of a hard elastic gel, the precipitating polymer; there follows a phase shift of the system, possibly with release of vehicle, and it is no longer possible to obtain a flow curve with a rheometer.
• the Applicant has also discovered that the passages between these states are reversible, and that the main factor making it possible to control the passage from one state to another is the temperature of the ink. For a given concentration of polymer in the ink, there is therefore a temperature range for which the ink exhibits a rheological behavior of non-continuous paste (or of fluid with a stress threshold). This state can be maintained, for example as long as the temperature of the ink does not drop below a certain threshold, which depends on the polymer concentration of the ink.
• the method preferably also includes the application of a temperature (called “target temperature”) so that the ink has a rheological behavior at a stress threshold.
• target temperature a temperature
• This target temperature can be applied during the dispersion of the fluoropolymer in the vehicle and / or once the fluoropolymer is already dispersed in the vehicle.
• the target temperature applied is from 0 to 60 ° C, more preferably from 5 to 55 ° C.
• the temperature is from 0 to 5 ° C, or 5 to 10 ° C, or 10 at 15 ° C, or 15 to 20 ° C, or from 20 to 25 ° C, or from 25 to 30 ° C, or from 30 to 35 ° C, or 35 àfl0 o C, or from 40 to 45 ° C, or from 45 to 50 ° C, or from 50 to 55 ° C, or from 55 to 60 ° Cpu from 60 to 65 ° C, or from 65 to 70 ° C.
• the target temperature is applied for a duration greater than or equal to one minute and preferably greater than or equal to one hour.
• the target temperature can be applied for a duration greater than or equal to 10 min, or greater than or equal to 30 min, or greater than or equal to 2 hours, or greater than or equal to 3 hours.
• the temperature can remain constant, or even vary, as long as it remains within a range of temperatures allowing the rheological behavior to be obtained at stress threshold.
• the target temperature may vary within the ranges listed above.
• a first temperature higher, can be first applied, so as to obtain a ink showing rheological behavior with Newtonian plate.
• the first temperature is from 30 to 100 ° C, for example from 30 to 40 ° C, or from 40 to 50 ° C, or from 50 to 60 ° C, or from 60 to 80 ° C or from 80 to 100 ° C.
• This first temperature can be applied during the dispersion of the fluoropolymer in the vehicle comprising the compound of formula (I) and / or after said dispersion.
• One (or more) rheological test (s) can be carried out on the ink thus produced in order to determine its rheological behavior.
• the dynamic viscosity of the ink can be measured as a function of the shear rate applied, over a given range of shear rate, for example from 0.01 to 1000 s -1 , or from 0.1 to 1000 s 1 .
• This measurement then makes it possible to draw a rheometric curve of the ink tested, called "flow curve".
• the measurement as well as the drawing of the curve can be carried out using a rheometer, for example in cone-plane configuration.
• the rheological behavior of the ink can be determined.
• the fluid that is to say the ink in the context of the present invention
• the flow curve is therefore of the horizontal line type (or essentially horizontal).
• the fluid exhibits a behavior of “shear thinning with Newtonian plateau” when its viscosity at low shear rate follows Newtonian behavior (that is to say that it remains constant), then begins to decrease from a certain shear rate. This leads to a flow curve with a Newtonian plateau (horizontal line) at low shear rate, followed, when the shear rate increases, a negative slope (representing a drop in viscosity, called shear thinning). If the shear rate tested is high enough, a new plateau may appear after rheofluidification giving rise to a flow curve with two plateaus (high and low shear rate).
• a fluid having a “stress threshold” type behavior is as defined above.
• the ink described above can be deposited on a substrate.
• the substrate may be a surface of a metal, whether or not coated with an oxide or nitride layer of said metal or of another metal, of a plastic material, of wood, of paper, of concrete, of mortar. or grout, glass, plaster, woven or nonwoven fabric, leather, etc.
• the substrate is a surface of glass, or silicon, whether or not coated with silicon nitride or oxides of silicon, or quartz, or of polymer material (in particular polyethylene terephthalate or polyethylene naphthalate), or of a metal other than silicon, or a mixed surface composed of several different materials, coated or not with passivating layers of oxides or nitrides metallic.
• the ink before being deposited on the substrate, can be subjected to a target temperature, so that it exhibits a rheological behavior with a stress threshold.
• the ink subjected to the target temperature (that is to say the ink before the application of said target temperature) may have a rheological behavior different from a behavior at a stress threshold, and may for example be in the form of a solution with rheological behavior with Newtonian plateau (Newtonian type fluid or rheofluidifier with Newtonian plateau).
• the target temperature and its application can be as described above.
• the ink before being deposited on the substrate, may be in the form of an elastic hard gel.
• the ink is preferably first subjected to a first temperature, so as to obtain an ink exhibiting a rheological behavior with Newtonian plate (the first temperature possibly being as described above) then it is subjected to a target temperature, so as to exhibit rheological behavior at a stress threshold (the target temperature can be as described above).
• the application of the ink according to the invention may comprise spreading by discrete or continuous means.
• the deposition can be carried out in particular by coating by centrifugation (“spin-coating”), by spraying or atomization (“spray coating”), by coating in particular with a bar or a film puller (“bar coating”), by coating with a slot head (“slot-die coating”), by immersion (“dip coating”), by roller printing (“roll-to-roll printing”), by screen printing (“screen-printing”), by flexographic printing, by lithographic printing.
• the ink is deposited by printing (in particular roller printing, screen printing, flexography, lithography) and even more advantageously, screen printing.
• the ink vehicle (comprising the compound of formula (I)) can be evaporated after deposition.
• the fluoropolymer layer (which may also optionally include one or more other polymers and / or additives) then solidifies to form a continuous film, by inter-diffusion of the polymer molecules.
• Evaporation can be carried out at room temperature and / or by heating at a temperature preferably ranging from 30 to 200 ° C, more preferably from 50 to 180 ° C, more preferably from 80 to 160 ° C.
• the layer can be ventilated to facilitate evaporation.
• the duration of the evaporation can for example be from 1 minute to 24 hours, preferably from 5 minutes to 5 hours, more preferably from 10 minutes to 2 hours.
• An annealing step can be carried out after evaporation of the vehicle, for example to allow or increase the crystallization of the polymer.
• Annealing can in particular be carried out by subjecting the deposited layer to a temperature of 50 to 200 ° C, preferably from 80 to 180 ° C, more preferably from 100 to 160 ° C, in particular from 120 to 150 ° C.
• the fluoropolymer layer thus formed may in particular have a thickness of 50 nm to 100 ⁇ m, preferably from 200 nm to 50 ⁇ m, and more preferably from 500 nm to 20 ⁇ m.
• a crosslinking step can be carried out by subjecting the layer to radiation, such as X, gamma, UV radiation or by thermal activation if the annealing step is not sufficient.
• radiation such as X, gamma, UV radiation or by thermal activation if the annealing step is not sufficient.
• the fluoropolymer film can be used as an electro-active layer and / or as a dielectric layer in an electronic device, and in particular when the fluoropolymer is a P (VDF-TrFE) or P (VDF-TrFE-CFE) copolymer ) or P (VDF-TrFE-CTFE) as described above.
• One or more additional layers can be deposited on the substrate provided with the fluoropolymer film, for example one or more layers of polymers, semiconductor materials, or metals, in a manner known per se.
• electronic device is meant either a single electronic component, or a set of electronic components, capable of performing one or more functions in an electrical or electronic circuit.
• the electronic device is more particularly an optoelectronic device, that is to say capable of emitting, detecting or controlling electromagnetic radiation.
• Examples of electronic devices, or if appropriate optoelectronic, concerned by the present invention are ferroelectric memories, transistors (in particular field effect), chips, batteries, electrodes, photovoltaic cells, light emitting diodes (LEDs) ), organic light emitting diodes (OLEDs), sensors, actuators, transformers, haptics, electromechanical microsystems (MEMS) and detectors.
• ferroelectric memories transistors (in particular field effect), chips, batteries, electrodes, photovoltaic cells, light emitting diodes (LEDs) ), organic light emitting diodes (OLEDs), sensors, actuators, transformers, haptics, electromechanical microsystems (MEMS) and detectors.
• Electronic and optoelectronic devices are used and integrated in many electronic devices, equipment or sub-assemblies and in many objects and applications such as televisions, computers, mobile phones, rigid or flexible screens, photovoltaic modules with layers thin, light sources, energy sensors and converters, medical devices, floors and walls, roofs and ceilings, etc.
• the fluoropolymer layer can be used as a protective coating (or encapsulation) for an electronic device, and in particular when the fluoropolymer is a P copolymer (VDF-HFP) as described above.
• a protective coating can be used alone or in combination with other protective films.
• the electronic device may in particular comprise a substrate and electronic elements supported thereon, which may include layers of conductive material, semiconductor material and the like.
• the electronic elements are preferably on one side of the substrate but in certain embodiments they can be on both sides of the substrate.
• the layer can cover all or part of the electronic elements, and all or part of the substrate.
• the layer covers at least part of the substrate and at least part of the electronic elements, and fulfills a planarizing function.
• the layer may cover only one of the two faces of the substrate (preferably the face which comprises the electronic elements), in whole or in part, or alternatively the two faces of the substrate, in whole or in part.
• Three inks are prepared by dispersing 10%, 12% and 14% (by weight) of Piezotech® "FC-20” copolymer (P copolymer (VDF-TrFE) comprising 80% of VDF units and 20% of TrFE units, in molar proportions) in diacetone alcohol, as a single vehicle, at temperatures above 50 ° C.
• P copolymer (VDF-TrFE) comprising 80% of VDF units and 20% of TrFE units, in molar proportions
• the inks prepared have a shear-thinning rheological behavior with a Newtonian plate.
• the inks are then allowed to cool slowly at rest (without shaking).
• An ink containing 14% by weight of dry extract of FC-20 high MFI (melt flow rate) copolymer in diacetone alcohol is prepared.
• the ink is heated to 50 ° C so that its initial state is that of a viscous shooting solution with a Newtonian plate.
• a first measurement of three scans at 40 ° C is carried out just after the preparation of the ink. Then, the measurements (each of three scans) are carried out without interruption, each measurement of three scans lasting from 13 to 14 min (a new measurement (or series) of 3 scans therefore starting from 13 to 14 min after the start of the measurement above), at a temperature maintained at 40 ° C.
• the ink then continues to reinforce over time this character of fluid with stress threshold, which is visible by a slope, at low shear rates, more and more pronounced, until reaching an equilibrium. (more evolution) after about 67 minutes in this experiment. From a practical point of view, the ink can be used from the appearance of the behavior of fluid at stress threshold and it will remain so for a long time.
• FC-20 high MFI copolymer in diacetone alcohol Two inks at 12 and 14% by weight of FC-20 high MFI copolymer in diacetone alcohol are prepared. The temperature is controlled so as to stabilize a behavior of non-stringing paste for the two inks.
• a measurement of three shears in shear rate is carried out for each of the inks as described in example 2, at 40 ° C.
• An ink containing 14% by weight of FC-20 high MFI copolymer in diacetone alcohol is prepared.
• a measurement of three sweeps in rate of shearing as described in example 2 is carried out at 40 ° C. on the ink pre-stabilized in the form of a non-shooting paste. Then another measurement is carried out in the same way but at 30 ° C.
• the ink of Example 2 When the ink of Example 2 reaches the rheological state of non-shooting paste with a stress threshold (from the state of viscous viscous solution), it is deformed by elongation, at a tensile deformation of several hundred percent, for at least part of the ink. This deformation is applied by moving the upper plate of the rheometer (the cone) away from the lower plate (the plane), which has the effect of exerting a tensile force, due to the adhesion forces of part of the ink on the upper plate. Then it is returned to the rheometer and a measurement at 40 ° C as described in Example 2 is carried out.
• a stress threshold from the state of viscous viscous solution
• transition temperatures from one rheological state to another vary depending on the polymer concentration of the ink. In particular, it is observed that the higher the polymer concentration of the ink, the higher the temperature below which the non-spinning paste turns into an elastic hard gel.
• the rheological behavior of non-spinning paste can be obtained by keeping the ink in the appropriate temperature range (i.e. between the transition temperature of non-spinning paste - elastic gel and the transition temperature of spinning solution - non-shooting paste), depending on its polymer concentration.

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• Chemical & Material Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Wood Science & Technology (AREA)
• Organic Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Inks, Pencil-Leads, Or Crayons (AREA)
• Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)

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• 2018
  • 2018-10-02 FR FR1859098A patent/FR3086666B1/fr not_active Expired - Fee Related
• 2019
  • 2019-09-30 EP EP19802239.4A patent/EP3861078A2/de not_active Withdrawn
  • 2019-09-30 CN CN201980077520.3A patent/CN113166571A/zh active Pending
  • 2019-09-30 WO PCT/FR2019/052299 patent/WO2020070419A2/fr unknown

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