Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F214/00—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
  • C08F214/18—Monomers containing fluorine
  • C08F214/26—Tetrafluoroethene
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F214/00—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
  • C08F214/18—Monomers containing fluorine
  • C08F214/26—Tetrafluoroethene
  • C08F214/262—Tetrafluoroethene with fluorinated vinyl ethers
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
  • C08J5/12—Bonding of a preformed macromolecular material to the same or other solid material such as metal, glass, leather, e.g. using adhesives
  • C08J5/121—Bonding of a preformed macromolecular material to the same or other solid material such as metal, glass, leather, e.g. using adhesives by heating
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
  • H01B3/00—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties
  • H01B3/18—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of organic substances
  • H01B3/30—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of organic substances plastics; resins; waxes
  • H01B3/44—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of organic substances plastics; resins; waxes vinyl resins; acrylic resins
  • H01B3/443—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of organic substances plastics; resins; waxes vinyl resins; acrylic resins from vinylhalogenides or other halogenoethylenic compounds
  • H01B3/445—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of organic substances plastics; resins; waxes vinyl resins; acrylic resins from vinylhalogenides or other halogenoethylenic compounds from vinylfluorides or other fluoroethylenic compounds

Definitions

• FEP fhiorinated ethylene - propylene copolymer
• the present disclosure provides a fluorinated ethylene - propylene (FEP) copolymer useful, for example, for wire coating.
• FEP fluorinated ethylene - propylene
• MFI melt flow index
• the copolymer can typically be extruded at high speed.
• the copolymer exhibits an onset of melt fracture at a higher shear rate than certain commercially available FEP copolymers.
• a combined number of unstable end groups, -CF2H end groups, and -CFH-CF3 end groups of at least 25 per 10 6 carbon atoms and up to 150 end groups per 10 6 carbon atoms, a balance of adhesion to metal (e.g., copper) and thermal stability useful for extrusion is achieved.
• the present disclosure provides a copolymer having tetrafluoroethylene units, hexafluoropropylene units, and units independently represented by formula
• Rf is a linear or branched perfluoroalkyl group having from 1 to 8 carbon atoms and optionally interrupted by one or more -O- groups, z is 1 or 2, each n is independently from 1 to 6, and m is 0 or 1.
• the copolymer has a melt flow index in a range from 25 grams per 10 minutes to 35 grams per 10 minutes and includes at least one of unstable end groups, -CFH-CF3 end groups, or -CF2H end groups.
• the unstable end groups typically comprise at least one of -COOM, -CH2OH, -COF, and -CONH2, wherein M is independently an alkyl group, a hydrogen atom, a metallic cation, or a quaternary ammonium cation.
• the combined total of unstable end groups, -CFH-CFi end groups, and -CF2H end groups in the copolymer is at least 25 per 10 6 carbon atoms and up to 150 per 10 6 carbon atoms.
• the present disclosure provides a method of making an extruded article.
• the method includes extruding a melted composition that includes the copolymer described above.
• the melted composition consists of the copolymer described above.
• the extruded article is a film, tube, pipe, or hose.
• the melted composition is extruded onto a conductor.
• the melted composition is extruded onto a cable.
• the present disclosure provides an extruded article that includes the copolymer described above.
• the extruded article is a film, tube, pipe, or hose.
• the extruded article is a conductor having the copolymer extruded on it.
• the extruded article is a cable having the copolymer extruded on it.
• the present disclosure provides a method of making the copolymer described above.
• the method includes copolymerizing components that include tetrafluoroethylene,
• Rf is a linear or branched perfluoroalkyl group having from 1 to 8 carbon atoms and optionally interrupted by one or more -O- groups, z is 1 or 2, each n is independently from 1 to 6, and m is 0 or 1.
• Copolymerizing may be carried out, for example, by aqueous emulsion polymerization or suspension polymerization.
• phrases “comprises at least one of followed by a list refers to comprising any one of the items in the list and any combination of two or more items in the list.
• the phrase “at least one of followed by a list refers to any one of the items in the list or any combination of two or more items in the list.
• perfluoro and “perfluorinated” refer to groups in which all C-H bonds are replaced by C-F bonds.
• -CF2CF2-O-CF2-CF2- is a perfluoroalkylene group interrupted by an -0-.
• copolymers according to the present disclosure may be useful for a variety of applications.
• copolymers according to the present disclosure are useful for insulating cable or wire.
• Such insulated cable may be useful, for example, as a communication cable (e.g., a data transmission cable such as a "Local Area Network” (LAN) cable).
• LAN Local Area Network
• the insulated cable can be manufactured by extrusion coating molten copolymer in the shape of a tube and then drawing down the copolymer by inserting a core wire through the center portion of the resin tube in its axial direction.
• drawdown as used herein means extending a molten resin extruded from a die having an opening of relatively large sectional area to its final intended dimensions.
• the draw -down is characterized by a draw-down ratio (DDR), which is the ratio of the sectional area of the opening of the die to the sectional area of the insulated material of the final product.
• DDR draw-down ratio
• the draw-down ratio is suitably from 50 to 150.
• the copolymer according to the present disclosure comprises a copolymer of tetrafluoroethylene (TFE) and hexafluoropropylene (HFP).
• the copolymer according to the present disclosure is an at least partially crystalline fluoroplastic.
• a person skilled in the art can select the amount of HFP to include in the copolymer to make an at least partially crystalline FEP.
• the HFP is present in a range from 5 weight percent (wt. %) to 22 wt. %, in a range from 10 wt. % to 17 wt. %, in a range from 11 wt. % to 16 wt. %, or in a range from 11.5 wt. % to 15.8 wt. %, based on the total weight of the copolymer.
• copolymer according to the present disclosure further includes copolymerized units independently represented by formula:
• n is from 1 to 4, or from 1 to 3, or from 2 to 3, or from 2 to 4.
• n is 1 or 3.
• n is 3.
• C n F 2n can be written as (CF 2 ) K , which refers to a linear perfluoroalkylene group.
• C n F 2n is -CF 2 -CF 2 -CF 2 -.
• CnF 2n is branched, for example, -CF 2 -CF(CF 3 )-.
• (OC n F 2n ) z is represented by -0-(CF 2 )i-4-[0(CF 2 )i_ 4 ]o-i.
• Rf is a linear or branched perfluoroalkyl group having from 1 to 8 (or 1 to 6) carbon atoms that is optionally interrupted by up to 4, 3, or 2 -O- groups. In some embodiments, Rf is a perfluoroalkyl group having from 1 to 4 carbon atoms optionally interrupted by one -0- group. In some embodiments, m is 0.
• suitable perfluoroalkoxyalkyl vinyl ethers include
• CF 2 CFOCF 2 CF 2 CF 2 CF 2 OCF 3
• CF 2 CFOCF 2 CF 2 OCF 2 CF 3
• CF 2 CFOCF 2 CF 2 CF 2 OCF 2 CF 3
• CF 2 CFOCF 2 CF 2 OCF 2 CF 2 CF 2 OCF 3
• CF 2 CFOCF 2 CF 2 OCF 2 CF 2 CF 2 OCF 3
• m is 1, and z, n, and Rf are as described above in any of their embodiments.
• copolymers are prepared by copolymerizing components including tetrafluoroethylene, hexafluoropropylene, and at least one perfluoroalkoxyalkyl allyl ether independently represented by formula in which n, z, and Rf are as defined above in any of their embodiments.
• CF 2 CFCF 2 OCF 2 CF 2 CF 2 OCF 2 CF 3
• CF 2 CFCF 2 OCF 2 CF 2 CF 2 CF 2 OCF 2 CF 3
• CF 2 CFCF 2 OCF 2 CF 2 OCF 2 CF 2 CF 2 OCF 3
• CF 2 CFCF 2 OCF 2 CF 2 OCF 2 CF 2 CF 2 OCF 3
• CF 2 CFCF 2 OCF 2 CF 2 OCF 2 CF 2 CF 2 CF 2 OCF 3
• CF 2 CFCF 2 OCF 2 CF 2 (OCF 2 ) 3 OCF 3
• CF 2 CFCF 2 OCF 2 CF 2 (OCF 2 ) 4 OCF 3
• CF 2 CFCF 2 OCF 2 CF 2 OCF 2 OCF 3
• CF2 CF20CF2CF 2 OCF 2 CF 2 OCF 2 CF 2 CF 3
• Many of these perfluoroalkoxyalkyl allyl ethers can be prepared, for example, according to the methods described in U.S. Pat. No. 4,349,650 (Krespan).
• copolymerized units independently represented by formula:
• the copolymerized units are present in the copolymer at up to 1.5 mole percent or up to 1.0 mole percent. In some embodiments, the copolymerized units represented by this formula are present in the copolymer in an amount of at least 0.03 mole percent or 0.05 mole percent. The copolymerized units may be present in the copolymer in a range from 0.02 mole percent to 2 mole percent, 0.05 mole percent to 1.5 mole percent, or 0.1 mole percent to 1.0 mole percent. Copolymers according to the present disclosure may include any combination of one or more of these copolymerized units according to any of the above embodiments.
• the FEP copolymer according to the present disclosure may include other copolymenzed units.
• the copolymer can include up to 3, 2, 1, or 0.5 mole percent of copolymerized units represented by formula in which Rfi is a linear or branched perfluoroalkyl group having from 1 to 8 carbon atoms.
• Rfi is a perfluoroalkyl group having from 1 to 6, 1 to 5, 1 to 4, or 1 to 3 carbon atoms.
• the copolymers according to the present disclosure are substantially free of such perfluoroalkyl vinyl ether-derived units.
• the copolymer can include up to 0.05, 0.02, or 0.01 mole percent of such perfluoroalkyl vinyl ether-derived units.
• the term "substantially free of also includes copolymers that include none of these perfluoroalkyl vinyl ether-denved units.
• the copolymers according to the present disclosure typically have a melting point between 220 ° C to 285 ° C, in some embodiments, 230 C to 280 ° C, 235 ° C to 275 ° C, 240 ° C to 270 ° C or 245 'C to 265 °C.
• the molecular weights of FEP copolymers are often characterized by the melt viscosity or the melt flow index (MFI, e.g., 372 °C/5 kg).
• MFI melt viscosity or the melt flow index
• the copolymer according to the present disclosure has an MFI of 30 ⁇ 5 grams per 10 minutes. In some embodiments, the copolymer according to the present disclosure has an MFI of 30 ⁇ 4 grams per 10 minutes or 30 ⁇ 3 grams per 10 minutes.
• the MFI is 30 ⁇ 5 grams per 10 minutes, high-speed extrusion is possible, the extruded polymer can be readily drawn down, and melt fracture (that is, abnormal flow and surface roughness of the extruded polymer) is minimized If the MFI is less than 25 grams per 10 minutes, high extrusion rates are difficult to achieve. Also, an FEP having an MFI of up to about 35 typically performs better under cable burn performance evaluation than FEP copolymers with higher MFIs due to a lower tendency to flow at high temperature.
• the copolymer according to the present disclosure can be adjusted to have an MFI of 30 ⁇ 5 grams per 10 minutes by adjusting the amount of the initiator and/or chain-transfer agent used during polymerization, both of which affect the molecular weight and molecular-weight distribution of the copolymer. MFI can also be controlled by the rate of addition of initiator to the polymerization. Variations in the monomer composition can also affect the MFI. For the purposes of the present disclosure, MFI is measured according to the test method described in the Examples, below.
• copolymers according to the present disclosure have an onset of melt fracture at a higher shear rate than certain commercially available FEP copolymers that either do not include oxygen-containing groups or include perfluoroalkoxy groups instead of perfluoroalkoxyalkyl pendant groups. Accordingly, copolymers according to the present disclosure may be useful at higher shear rates than such comparative FEP copolymers having comparable levels of perfluoroalkyl vinyl ether modification. We have also observed that even at low levels, a comonomer having a
• perfluoroalkoxyalkyl pendant group increases the elongation viscosity of an FEP copolymer and has a positive effect on the rupture durability and cable burn performance of the FEP copolymer.
• the production of foamed insulation cable is different from the high line speed production of solid wire insulation, and lower MFIs are useful in the production of foamed insulation cable.
• the copolymer according to the present disclosure is not foamed.
• the copolymer generally does not include a foam cell nucleating agent (e.g., a
• the extruded article is not foamed or does not include a foam cell nucleating agent. In some of these embodiments, the extruded article is not a foamed insulation cable.
• the copolymer according to the present disclosure can include a foam cell nucleating agent as described above.
• the extruded article is foamed or includes a foam cell nucleating agent.
• the extruded article is a foamed insulation cable.
• the copolymer according to the present disclosure has a relatively low polydispersity.
• the polydispersity which is a ratio of the weight-average molecular weight (Mw) to the number-average molecular weight (Mn) of the copolymer, can be up to about 2.5, 2.3, 2.2, or 2.0.
• the polydispersity may be as low as 1.5.
• Polydispersity is measured according to a modified version of the method published by W. H. Tuminello in Polym. Eng. Sci. 26, 1339 (1986), described in the Examples, below.
• Copolymers according to the present disclosure can be prepared in a variety of ways.
• the method of making the copolymer according to the present disclosure includes radical aqueous emulsion polymerization
• perfluorinated or partially fluorinated emulsifiers may be useful. Generally these fluorinated emulsifiers are present in a range from about 0.02% to about 3% by weight with respect to the polymer. Polymer particles produced with a fluorinated emulsifier typically have an average diameter, as determined by dynamic light scattering techniques, in range of about 10 nanometers (nm) to about 300 nm, and in some embodiments in range of about 50 nm to about 200 nm.
• Suitable emulsifiers include perfluorinated and partially fluorinated emulsifier having the formula [Rf-0-L-COO " ]iX 1+ wherein L represents a linear partially or fully fluorinated alkylene group or an aliphatic hydrocarbon group, Rf represents a linear partially or fully fluorinated aliphatic group or a linear partially or fully fluorinated aliphatic group interrupted with one or more oxygen atoms, X 1+ represents a cation having the valence i and i is 1, 2 or 3. (See, e.g., U.S. Pat. No. 7,671,112 to Hintzer et al.).
• Suitable emulsifiers also include perfluorinated polyether emulsifiers having the formula CF3-(OCF2) x -0-CF2 -X, wherein x has a value of 1 to 6 and X represents a carboxylic acid group or salt thereof, and the formula CF 3 -0-(CF 2 ) 3 -(OCF(CF 3 )-CF 2 ) y -0-L-Y wherein y has a value of 0, 1, 2 or 3, L represents a divalent linking group selected from -CF(CF3)-, -CF2-, and
• Y represents a carboxylic acid group or salt thereof.
• Suitable emulsifiers include perfluorinated polyether emulsifiers having the formula Rf-0(CF2CF20) x CF2COOA wherein Rf is CbFpb+ij; where b is 1 to 4, A is a hydrogen atom, an alkali metal ⁇ ⁇ 3 ⁇ 4, and x is an integer of from 1 to 3. (See, e g , U.S. Pat. Publ. No.
• Suitable emulsifiers also include perfluonnated emulsifiers having the formula F(CF2) b O(CF2CF20) x CF2COOA wherein A is a hydrogen atom, an alkali metal or NH , b is an integer of from 3 to 10, and x is 0 or an integer of from 1 to 3. (See, e.g., U.S. Pat. Publ. No.
• emulsifiers include fluorinated polyether emulsifiers as described in U.S. Pat. No. 6,429,258 to Morgan et al. and perfluorinated or partially fluorinated alkoxy acids and salts thereof wherein the perfluoroalkyl component of the perfluoroalkoxy has 4 to 12 carbon atoms, or 7 to 12 carbon atoms. (See, e.g., U.S. Pat. No. 4,621, 1 16 to Morgan).
• Suitable emulsifiers also include partially fluorinated polyether emulsifiers having the formula [Rf-(0)t-CHF-(CF2) x -COO-]iX 1+ wherein Rf represents a partially or fully fluorinated aliphatic group optionally interrupted with one or more oxygen atoms, t is 0 or 1 and x is 0 or 1 , X 1+ represents a cation having a valence i and i is 1, 2 or 3. (See, e.g., U.S. Pat. Publ. No. 2007/0142541 to Hintzer et al.).
• emulsifiers include perfluorinated or partially fluorinated ether-containing emulsifiers as described in U.S. Pat. Publ. Nos. 2006/0223924, 2007/0060699, and 2007/01425 13 each to Tsuda et al. and 2006/0281946 to Morita et al.
• Fluoroalkyl for example, perfluoroalkyl carboxylic acids and salts thereof having 6-20 carbon atoms, such as ammonium perfiuorooctanoate (APFO) and ammonium perfluorononanoate (see, e.g., U.S. Pat. No. 2,559,752 to Berry) may also be useful.
• APFO ammonium perfiuorooctanoate
• U.S. Pat. No. 2,559,752 to Berry may also be useful.
• the emulsifiers can be removed or recycled from the fluoropolymer latex as described in U.S. Pat. Nos. 5,442,097 to Obermeier et al., 6,613,941 to Felix et al, 6,794,550 to Hmtzer et al, 6,706, 193 to Burkard et al, and 7,018,541 to Hintzer et al.
• the polymerization process may be conducted with no emulsifier or with no fluorinated emulsifier.
• a water-soluble initiator can be useful to start the polymerization process.
• Salts of peroxy sulfuric acid such as ammonium persulfate or potassium persulfate, are typically applied either alone or sometimes in the presence of a reducing agent, such as bisulfites or sulfmates (e.g., fluorinated sulfmates disclosed in U.S. Pat. Nos. 5,285,002 and 5,378,782, both to Grootaert) or the sodium salt of hydroxy methane sulfimc acid (sold under the trade designation "RONGALIT", BASF Chemical Company, New Jersey, USA).
• a reducing agent such as bisulfites or sulfmates (e.g., fluorinated sulfmates disclosed in U.S. Pat. Nos. 5,285,002 and 5,378,782, both to Grootaert) or the sodium salt of hydroxy methane sulfimc acid (sold under the trade designation "RONGALIT",
• Buffers include phosphate, acetate, or carbonate (e.g., or NaHCCh) buffers or any other acid or base, such as ammonia or alkali- metal hydroxides.
• concentration range for the initiators and buffers can vary from 0.01% to 5% by weight based on the aqueous polymerization medium
• the copolymer according to the present disclosure generally comprises at least 50 ppm alkali-metal cations.
• alkali-metal cations we have found that the presence of alkali-metal cations in the copolymer increases the rate of decomposition of unstable carboxylic end-groups to provide more stable -CF2H and -CFH-CF3 end groups during the drying step described below and therefore makes a subsequent post-fluorination step, if needed, easier, faster, and cheaper
• polymerization is conducted in the absence of added alkali-metal salts.
• potassium persulfate a common alternative initiator or co-initiator with ammonium persulfate
• organic initiators as disclosed in U.S. Pat. No. 5, 182,342 (Feiring et al ).
• the copolymer produced can have less than 50 ppm alkali-metal cations, in some embodiments, less than 25 ppm, less than 10 ppm, or less than 5 ppm alkali-metal cation. To achieve such low alkali-metal content, the water for polymerization and washing may be deionized.
• Minimizing the alkali-metal cation concentration in the copolymer may minimize the formation of die drool that may form during a high speed conductor coating operation on the outer surface of an extrusion die or on the guider tip inside the die.
• This die drool if not minimized, can be periodically carried along the melt and/or the conductor to form undesirable lumps, which may cause cone-breaks.
• the alkali-metal ion content of the copolymer can be measured by flame atomic absorption spectrometry after combusting the copolymer and dissolving the residue in an acidic aqueous solution according to the method described in the Examples, below.
• the lower detection limit is less than 1 ppm.
• Typical chain-transfer agents like 3 ⁇ 4, lower alkanes, alcohols, ethers, esters, and methylene fluoride may be useful in the preparation of the copolymer according to the present disclosure.
• Termination primarily via chain-transfer results in a polydispersity of about 2 or less.
• the polymerization is carried out without any chain-transfer agents.
• a lower polydispersity can sometimes be achieved in the absence of chain- transfer agents. Recombination typically leads to a polydispersity of about 1.5 for small conversions.
• Useful polymerization temperatures can range from 40 °C to 120 °C. Typically, polymerization is carried out in a temperature range from 40 ° C to 100 C or 50 ° C to 80 ° C.
• the polymerization pressure is usually in the range of 0.8 MPa to 2.5 MPa, and in some embodiments in the range from 1.0 MPa to 2.0 MPa.
• HFP can be precharged and fed into the reactor as described, for example, in Modern
• Perfluoroalkoxyalkyl vinyl ethers represented by formula and perfluoroalkoxyalkyl ally] ethers represented by formula wherein n, z, and Rf are as defined above in any of their embodiments, are typically liquids and may be sprayed into the reactor or added directly, vaporized, or atomized.
• perfluoroalkoxyalkyl allyl ethers represented by formula also be pre- emulsified with an emulsifier before being combined with the other comonomers, for example, before addition of a gaseous fluoroolefin.
• the obtained polymer dispersion after aqueous emulsion polymerization can be used as is or, if higher solids are desired, can be upconcentrated.
• any coagulant which is commonly used for coagulation of a fluoropolymer latex may be used, and it may, for example, be a water-soluble salt (e.g., calcium chloride, magnesium chloride, aluminum chloride or aluminum nitrate), an acid (e.g., nitric acid, hydrochloric acid or sulfuric acid), or a water-soluble organic liquid (e.g., alcohol or acetone).
• a water-soluble salt e.g., calcium chloride, magnesium chloride, aluminum chloride or aluminum nitrate
• an acid e.g., nitric acid, hydrochloric acid or sulfuric acid
• a water-soluble organic liquid e.g., alcohol or acetone
• the amount of the coagulant to be added may be in a range of 0.001 to 20 parts by mass, for example, in a range of 0.01 to 10 parts by mass per 100 parts by mass of the fluoropolymer latex.
• the fluoropolymer latex may be frozen for coagulation or mechanically coagulated, for example, with a homogenizer as described in U.S. Pat. No. 5,463,021 (Beyer et al.).
• the copolymer comprises less than 50 ppm alkali-metal salt
• the coagulated copolymer can be collected by filtration and washed with water.
• the washing water may, for example, be ion-exchanged water, pure water, or ultrapure water.
• the amount of the washing water may be from 1 to 5 times by mass to the copolymer, whereby the amount of the emulsifier attached to the copolymer can be sufficiently reduced by one washing.
• the coagulated copolymer may be agglomerated to produce the polymer in agglomerate form.
• Agglomerates are typically free-flowing spherical beads with an average size (that is, diameter) of 1 mm to 5 mm. If the agglomerates obtained from agglomerating the coagulated copolymer are too small, it may be desirable to compact the agglomerate to produce a compacted agglomerate which will typically have an average size of 1 mm to 10 mm.
• the coagulated copolymer is agglomerated with a water-immiscible organic liquid like gasoline as described in Modern
• the agglomerate can be dried, for example, by heating under moderate vacuum at temperatures up to 250 ° C, 200 ° C, 190 ° C, 180 ° C, 150 ° C, or l30 D C.
• radical polymerization also can be carried out by suspension polymerization.
• Suspension polymerization will typically produce particle sizes up to several millimeters.
• the copolymer may be melted, extruded, and cut into granulates of a desired size, which may be called melt granulate.
• Fluorinated thermoplastics tend to degrade thermally when processed. The thermal degradation takes place predominantly via the thermally unstable end groups formed during the polymerization, that is, from the end of the chain.
• FEP copolymers obtained by aqueous emulsion polymerization with inorganic initiators e g persulfates, KMnOzi, etc.
• inorganic initiators e g persulfates, KMnOzi, etc.
• Unstable end groups in the copolymers according to the present disclosure include -COOM,
• the unstable end groups are
• the fluoropolymer can be treated with ammonia to form the more stable amide end group -CONH2 or with a primary or secondary amine (e.g., dimethyl, diethyl, or propyl amine) to form amide end groups -CONRH or -CONR2, wherein R is/are the alkyl group(s) of the amine, and wherein for R2, the alkyl groups are the same or different.
• a primary or secondary amine e.g., dimethyl, diethyl, or propyl amine
• the fluoropolymer can be treated with an alcohol, such as methanol, ethanol, propanol, or a fluorine containing alcohol to form the more stable ester end groups -COOR', where R' is the alkyl group supplied by the alcohol.
• an alcohol such as methanol, ethanol, propanol, or a fluorine containing alcohol
• R' is the alkyl group supplied by the alcohol.
• post-fluorination of the fluoropolymer can be used to convert the end groups to -CF3 end groups.
• the fluoropolymer can be decarboxylated to form the more stable -CF2H and -CFH-CF3 end groups, respectively.
• Treatment of fluoropolymers at high temperatures (e.g., 400 ° C) with water vapor has been shown to reduce the number of unstable end groups, typically forming -CF2H and -CFH-CF3 end groups. See, e.g., U.S. Pat. No. 3,085,083 (Schreyer).
• the method of making the copolymer according to the present disclosure can include any of these methods.
• copolymers according to the present disclosure include -CF2H and -CFH-CF3 end groups.
• the dried polymer contains predominantly -CF2H and -CFH-CF3 end groups as described above.
• -CF2H and -CFH-CF3 end groups are sufficiently stable for some applications.
• post-fluorination is desired to convert some of the -CF2H and -CFH-CF3 end groups into -CF3 and -C2F5 end groups, respectively, the post-fluorination is generally easier and faster than when many -COOH end groups are present since fewer fluorination cycles are needed to convert the -CF2H and -CFH-CF3 end groups in comparison to -COOH end groups.
• the copolymer according to the present disclosure has a combined total of unstable end groups and -CF2H and -CFH-CF3 end groups of at least 25 per 10 6 carbon atoms. In some embodiments, the copolymer according to the present disclosure has combined total of unstable end groups and -CF2H and -CFH-CF3 end groups of at least 40 or 50 or greater than 50 per 10 6 carbon atoms.
• the copolymer according to the present disclosure has at least 25 or more than 25 -COOM and -COF end groups per 10 6 carbon atoms, wherein M is as defined above in any of its embodiments.
• M is a hydrogen atom.
• the copolymer according to the present disclosure can have at least 30, 35, 40, or 50 -COOM and -COF end groups per 10 6 carbon atoms.
• a balance of adhesion to the conductor (e.g., copper) and the thermal stability needed for extrusion can be achieved by limiting the combined total of unstable end groups and -CF2H and -CFH-CF3 end groups to up to 150 per 10 6 carbon atoms.
• the copolymer according to the present disclosure has a combined total of unstable end groups and -CF2H and
• the copolymer according to the present disclosure has a combined total of unstable end groups and -CF2H and -CFH-CF3 end groups in a range from 25 per 10 6 carbon atoms to 120 per 10 6 carbon atoms or 30 per 10 s carbon atoms to 100 per 10 6 carbon atoms.
• the copolymer according to the present disclosure has unstable end groups (e.g., -COOM end groups wherein M is as defined above and -COF end groups) in a range from 35 per 10 6 carbon atoms to 90 per 10 6 carbon atoms or 40 per 10 s carbon atoms to 80 per 10 6 carbon atoms.
• unstable end groups e.g., -COOM end groups wherein M is as defined above and -COF end groups
• -CFH-CF3 end groups, and -CF2H end groups in these ranges either a shorter reaction time or lower reaction temperature can be used in the various reactions described above for eliminating unstable end groups.
• the fluorine concentration in the fluorine/nitrogen mixture used can be reduced to achieve the desired remaining amount of unstable end groups, -CFH-CF3 end groups, and -CF2H end groups.
• the combined number of unstable end groups, -CFH-CF3 end groups, and -CF2H end groups can be controlled, for example, by selection of the initiator and/or buffer for the polymerization and the conditions for post-fluorination or other treatments as described above.
• the number and type of end groups can be determined by Fourier transform infrared spectroscopy, as described in the Examples, below.
• the present disclosure provides a copolymer comprising
• Rf is a linear or branched perfluoroalkyl group having from 1 to 8 carbon atoms and optionally interrupted by one or more -O- groups, wherein the copolymer has a melt flow index in a range from 25 grams per 10 minutes to 35 grams per 10 minutes measured at a temperature of 372 °C and at a support weight of 5.0 kg, wherein the copolymer has a combined number of unstable end groups-CFH-CF3 end groups, and -CF2H end groups in a range from 25 per 10 6 carbon atoms up to 150 per 10 6 carbon atoms, wherein the unstable end groups are selected from the group consisting of -COOM, -CH2OH, -COF, and -CONH2, and wherein M is independently an alkyl group, a hydrogen atom,
• the present disclosure provides the copolymer of the first embodiment, wherein m is 0.
• the present disclosure provides the copolymer of the first or second embodiment, wherein Rf is -CF 3 , and wherein n is 1 or 3.
• the present disclosure provides the copolymer of the third embodiment, wherein n is 3, and z is 1.
• the present disclosure provides the copolymer of any one of the first to fourth embodiments having at least 25 unstable (e.g., -COOM and -COF) end groups per 10 6 carbon atoms.
• the present disclosure provides the copolymer of any one of the first to fifth embodiments having at least 50 unstable (e.g., -COOM and -COF) end groups per 10 6 carbon atoms.
• the present disclosure provides the copolymer of any one of the first to sixth embodiments having combined number of unstable end groups, -CFH-CF3 end groups, and -CF2H end groups up to 120 per 10 6 carbon atoms.
• the present disclosure provides the copolymer of any one of the first to seventh embodiments havmg up to 80 or 75 unstable (e.g., -COOM and -COF) end groups per 10 6 carbon atoms.
• unstable e.g., -COOM and -COF
• the present disclosure provides the copolymer of any one of the first to eighth embodiments, wherein the copolymer comprises less than 50 ppm alkali-metal cations.
• the present disclosure provides the copolymer of any one of the first to eighth embodiments, wherein the copolymer comprises at least 50 ppm alkali-metal cations.
• the present disclosure provides the copolymer of any one of the first to tenth embodiments, wherein the copolymer has a polydispersity of less than or equal to 2.5.
• the present disclosure provides the copolymer of any one of the first to eleventh embodiments, wherein the hexafluoropropylene units are present in the copolymer at 10 percent to 17 percent by weight, based on the total weight of the copolymer.
• the present disclosure provides the copolymer of any one of the first to the twelfth embodiments having a melting point in a range from 220 °C to 285 °C.
• the present disclosure provides the copolymer of any one of the first to thirteenth embodiments, wherein the copolymer is not foamed.
• the present disclosure provides the copolymer of any one of the first to thirteenth embodiments, wherein the copolymer is foamed.
• the present disclosure provides the copolymer of any one of the first to fifteenth embodiments, wherein the copolymer has a melt flow index in a range from 27 grams per 10 minutes to 33 grams per 10 minutes.
• the present disclosure provides the copolymer of any one of the first to sixteenth embodiments, further comprising units represented by formula
• Rfi is a perfluoroalkyl group having from 1 to 8 carbon atoms.
• the present disclosure provides a method of making an extruded article, the method comprising extruding a melted composition comprising (or consisting of) the copolymer of any one of the first to seventeenth embodiments.
• the present disclosure provides the method of the eighteenth embodiment, wherein the extruded article comprises at least one of a film, tube, pipe, or hose.
• the present disclosure provides the method of the eighteenth or nineteenth embodiment, wherein the melted composition is extruded onto a conductor
• the present disclosure provides the method of any one of the eighteenth to twentieth embodiments, wherein the melted composition is extruded onto a cable or wire.
• the present disclosure provides an extruded article comprising the copolymer of any one of the first to seventeenth embodiments.
• the present disclosure provides the extruded article of the twenty- second embodiment, wherein the extruded article comprises at least one of a film, tube, pipe, or hose.
• the present disclosure provides the extruded article of the twenty- second or twenty -third embodiment, wherein the extruded article is a conductor having the copolymer extruded thereon.
• the present disclosure provides the extruded article of any one of the twenty-second to twenty-fourth embodiments, wherein the extruded article is a cable or wire having the copolymer extruded thereon.
• the present disclosure provides the method of any one of the eighteenth to twenty-first embodiments or the extruded article of any one of the twenty-second to twenty- fifth embodiments, wherein the extruded article is not foamed.
• the present disclosure provides the method of any one of the eighteenth to twenty-first embodiments or the extruded article of any one of the twenty-second to twenty- fifth embodiments, wherein the extruded article is foamed.
• the present disclosure provides a method of making the copolymer of any one of the first to seventeenth embodiments, the method comprising copolymerizing components comprising tetrafluoroethylene, hexafluoropropylene, and at least one compound independently represented by formula wherein m is 0 or 1, each n is independently from 1 to 6, z is 1 or 2, and Rf is a linear or branched perfluoroalkyi group having from 1 to 8 carbon atoms and optionally interrupted by one or more -0- groups.
• the present disclosure provides the method of the twenty-eighth embodiment, wherein copolymerizing is carried out by aqueous emulsion polymerization.
• the present disclosure provides the method of the twenty-eighth embodiment, wherein copolymerizing is carried out by suspension polymerization.
• the present disclosure provides the method of the twenty-ninth or thirtieth embodiments, wherein the aqueous emulsion polymerization or suspension polymerization is carried out in the presence of a buffer comprising alkali -metal cations.
• the present disclosure provides the method of any one of the twenty-eighth to thirty-first embodiments, wherein the components further comprise an initiator comprising an alkali-metal cation.
• abbreviations include g for grams, kg for kilograms, m for mass, mm for millimeters, L for liters, min for minutes, hrs for hours, rpm for revolutions per minute
• melt flow index reported in g/10 min, was measured with a Goettfert MPX 62.92 melt indexer (Buchen, Germany) following a similar procedure to that described in DIN EN ISO
• the melting point of the fluorothermoplastic polymer was determined using differential scanning calorimetry following a similar procedure to that described in ASTM D4591-07 (2012) using a PerkinElmer Pyris 1 DSC (Waltham, Mass., USA) under nitrogen flow with a heating rate of 10 °C/min.
• the reported melting points relate to the melting peak maximum.
• the latex particle size determination was conducted by means of dynamic light scattering with a Malvern Zetasizer 1000HSA (Malvern, Worcestershire, UK) following a similar procedure to that described in DIN ISO 13321 :2004-10. The reported average particle size is the z-average. Prior to the measurements, the polymer latexes as yielded from the polymerizations were diluted with 0.001 mol/L KCl-solution. The measurement temperature was 20 °C in all cases.
• MA-3, MV-31, PPVE-1, PSEPVE and HFP reported in units of m/m%, was determined from an IR band at a monomer-specific wavenumber M and was calculated as a product of a monomer-specific factor 3 ⁇ 4i and the ratio of the absorbance of the IR-peak at VM, A(VM), to the absorbance of the IR-peak at 2365 cm -1 , (2365 cm -1 ), meaning 3 ⁇ 4I X-4(VM)/-4(2365 cm -1 ).
• Wavenumbers VM and factors 3 ⁇ 4i are given in the following table:
• Polymer end group detection was conducted in analogy to the method described in U.S. Pat. No. 4,743,658 (Imbalzano et al.). Thin films of approximately 0.50 mm were scanned on the same Nicolet Model 510 Fourier-transform infrared spectrometer. 16 scans were collected before the transform is performed, all other operational settings used were those provided as default settings in the Nicolet control software. Similarly, a film of a reference material known to have none of the end groups to be analyzed was molded and scanned. The reference absorbance spectrum is subtracted from the sample absorbance, using the interactive subtraction mode of the software. The CF 2 overtone band at 2365 wavenumbers is used to compensate for thickness differences between sample and reference during the interactive subtraction.
• the difference spectrum represents the absorbances due to non-perfluorinated polymer end groups.
• the calibration factors (CF) used to calculate the numbers of end groups per million carbon atoms are summarized in the following table:
• the absorbance of the -SO3H peak was not quantified using the OMNIC software of the Nicolet Model 510 Fourier-transform infrared spectrometer, because the weak - SO3H peak is partially overlapping by other peaks in the direct neighborhood of 1063 1/cm and it appears as part of a peak-shoulder around 1050 1/cm.
• the deconvolution software "Peak Fit” from AISN Software Inc., version 4.06 was used to determine the absorbance the -SO3H peak.
• the automatic peak detection and fitting method II, second derivative method was applied with usually about 22 % smoothing to a wavenumber region of 1020 to 1075 1/cm.
• Four Pearson VII Amplitude peaks of uniform width and a linear 2 point baseline were usually applied to fit that region.
• the -SO3H peak is the one located at the highest wavenumber, the corresponding absorbance is the parameter aO taken from peak fit summary.
• the -CF 2 H peak is discernible at a peak around 3009 1/cm with a shoulder at about 2983 1/cm.
• the -CF(CF3)H group shows a broad peak band with mam peaks around 2973, 2930 and 2858 1/cm.
• the peak deconvolution procedure needs to be applied to the wavenumber region in between 2820 and 3050 1/cm. Then, the contributions of both groups to the broad peak need to be separated from each other and considered independently using the equations given above.
• Oscillatory shear flow measurements were conducted on fluoropolymer melts using a strain controlled ARES rheometer (3ARES-13; Firmware version 4.04.00) (TA Instruments Inc., New Castle, DE, USA) equipped with a FRT 200 transducer with a force range of up to 200 g.
• Dynamic mechanical data were recorded in nitrogen atmosphere in frequency sweep experiments using a 25 mm parallel plate geometry and a plate to plate distance of usually 1 8 mm was realized. Individual frequency sweeps were recorded at a temperature of 372 °C, 340 °C, 300 °C, 280 °C and in super-cooled melt at 260 °C.
• the thermal control of the oven was operated using the sample/tool thermal element.
• CMWD cumulative molecular weight distribution
• CMWD 100 X ⁇ 1-[G ' (CO)/GN 0 ] 0'5 ⁇ .
• a user defined fit routine operating under the software SigmaPIot 12.5 (Systat Software, Inc.; San Jose/CA, USA) was used to determine the two fit parameters xO and chi.
• the first derivative of the fit function was evaluated by applying the macro "Compute 1 st Derivative" provided by the SigmaPIot 12.5 software.
• the first derivative of the fit function is representing a Schulz-Zimm distribution described by Equation (6) in Auhl et al., Macromolecules 2006, Vol. 39, No. 6, p. 2316-2324.
• the maximum of this distribution is given by the number average molecular weight MN and its breadth is controlled by the degree of coupling k.
• the degree of coupling k is then converted into the polydispersity index MW/MN according to a 5 -order polynomial:
• the acidic solution was further analyzed by an "AANALYST 200" Perkin Elmer flame atomic absorption spectrometer (Waltham, Massachusetts/USA). The instrument was calibrated with 0.500 ppm and 1.000 ppm potassium aqueous standard solutions (Merck; Darmstadt/Germany;
• the peak height at a wavelength of 766.5 nm was used to evaluate the potassium content.
• the peak height at a wavelength of 589 nm was used to evaluate the sodium content.
• the peel strength of copper-polymer interfaces was determined using a Zwick materials testing machine Z010 with the software TestExpert 2 (Ulm, Germany).
• a 0.05 mm thick copper foil (O.F.H.C, 99.95 %, half hard; Sigma- Aldrich, St. Louis, MO, USA) was cleaned by storing it for 30 min at ambient temperature in an 1.5 wt. % aqueous solution of sulfamic acid (98 %, Sigma- Aldrich), subsequent rinsing with purified water, and drying with a paper towel.
• Copper foil and polymer were pressed in between two 50 ⁇ thick Kapton ® 200 HN foils (Krempel, Vaihingen an der Enz, Germany) for 5 min at 360 °C and 53 bar to generate a 0.8 mm thick copper-polymer plate. Part of the copper foil was separated from the polymer during heat-pressing by a Kapton ® foil to avoid bonding in this part. After conditioning for 20 hours at ambient pressure and 23 °C as well as removal of the Kapton ® foils, 15 mm wide test specimens were punched out by means of a DIN 53455-08.1981 type punching knife (for test specimen no. 5; NAEF, Adliswil, Switzerland).
• the unbonded copper end was bent by 180° and then both unbonded ends were clamped in the test grips of the materials testing machine.
• the load was applied at 23 °C at a constant head speed of 150 mm/min and the load versus head movement was recorded while separating both materials at an angle of approximately 180°.
• the average peeling load for the first 30 mm of peeling after the initial peak was determined in Newton.
• the peel strength data reported herein refer to an average of at least four individual test runs.
• the barrel was heated to 375 °C and filled with 60 g of the material, which was then extruded at 375 °C, through a sequence of shear rates.
• the pressure was increased to 0.5 MPa, followed by a dwell time of 6 min, and then increased again to 0.5 MPa, followed by a dwell time of 3 min.
• An initial shear rate of 400/s was used as a conditioning step, followed by sequential steps at 10, 15, 25, 40, 60, 100, 150, 250, 400, 600, 1000/s or 40, 60, 100, 150, 200, 300, 400, 600, 1000, 1500/s.
• the pressure was allowed to equilibrate at each step before the pressure was recorded
• the sequence was followed until the rheometer barrel was empty, at which point the test was stopped.
• the apparent shear rate and the apparent shear stress were calculated for each extrusion condition. No corrections were applied. See F.N. Cogswell, "Polymer Melt Rheology", Ed. John Wiley & Sons, New-York. According to F.N. Cogswell, the Rabinovich correction is at the most 15%.
• An extrudate strand was collected at each shear rate and examined under a reflection microscope (magnification 10 to 35X) to assess the appearance of the strand. The shear rate at which melt fracture onset occurred was visually determined.
• TFE tetrafluoroethylene
• HFP hexafluoropropylene
• MV-31 A copolymer of TFE (tetrafluoroethylene), HFP (hexafluoropropylene), and MV-31
• the polymerization was initiated by adding 65 g ammonium peroxydisulfate (APS), dissolved in 500 mL H2O.
• APS ammonium peroxydisulfate
• the polymerization temperature was maintained at 70 °C and the pressure was kept at 17 bar (1700 kPa).
• the monomer feed was constant; overall 12.4 kg TFE, 1.12 kg HFP and 161 g MV-31 were fed.
• the total runtime was 5 hours.
• the obtained latex had a solid content of 31.1 wt %, and the average particle size was 79 nm
• the latex was coagulated by the addition of aqueous 35 wt % HQ, agglomerated with gasoline, washed with deionized 3 ⁇ 40 and dried for 16 hours at 190 °C to provide the polymer.
• the MFI (372 °C/5 kg) was 27 g/10 min, the melting point was 247 °C, the MV-31 -content was determined as 0.64 wt %, and the HFP -content was determined as 11 wt %.
• the alkali ion content was ⁇ 1 ppm.
• the polydispersity MW/MN was determined as 1.72.
• the polymer from Part A was post-fluorinated.
• a 10-L-post-fluorination reactor was charged with 100 g of the dried polymer.
• the oxygen-free reactor was then heated up to 200 °C.
• the reactor was evacuated to 0.250 bar absolute (25 kPa).
• the vacuum was broken up to a pressure of 0.99 bar absolute (99 kPa) with a with a fluorine gas/nitrogen gas mixture (10 vol. % / 90 vol. %, N50, Air Liquide; Munchen/Germany).
• the fluorine/nitrogen mixture was evacuated to a pressure of 0.250 bar absolute (25 kPa).
• the procedure was repeated four times as shown in Table 1. Afterwards, the reactor was vented and flushed with nitrogen for 30 cycles.
• a portion (1312 g) of the dispersion from Example 1 was diluted to a solids content of 22.86 wt.% with deionized water, filtered, and added to a 3-L beaker. Under gentle stirring, 30 g of a 10 wt.% OH solution were added, and this mixture was stirred for 5 min.
• the latex was coagulated by the addition of aqueous 35 wt % HC1, agglomerated with gasoline, washed with deionized water, and dried for 16 hours at 190 °C to provide the polymer.
• the potassium content was determined to be 270 ppm.
• the polymer was then post-fluorinated according to the method of Example 1, Part B . Two fluorination cycles were carried out as shown in Table 1.
• Examples 1 and 2 and Illustrative Examples 1 to 3 were evaluated for peel strength to copper using the test method described above. The results are shown in Table 2, below.
• a portion of the agglomerated and washed polymer was dried at 190 ° C for 16 hours to provide Illustrative Example .
• the end groups were analyzed using the method described above, and the results are shown in Table 3, below. Additional properties of the dry polymer of Illustrative Example 5 are shown in Table 4, below.
• a portion of the agglomerated and washed polymer was dried at 130 °C for 16 hours to provide Illustrative Example 4. The end groups were analyzed using the method described above, and the results are shown in Table 3, below. Table 3:
• the latex particles were 97 nm in diameter as measured by dynamic light scattering.
• the polymer was dried for 16 hr at 190 ° C. Properties of the dry polymer agglomerate are shown in Table 4, below.
• the copolymer of Illustrative Example 7 was prepared in the same manner as in Illustrative
• the latex particles were 94 nm in diameter as measured by dynamic light scattering.
• the polymer was dried for 16 hr at 190 ° C. Properties of the of the dry polymer agglomerate are shown in Table 4, below.
• the copolymer from Illustrative Example 5 was melt pelletized and the melt pellets were converted into a tumbling drier available from OHL Apparatebau (Limburg a.d. Lahn/Germany) so that a volume filling level of 70% achieved.
• the oxygen-free tumbling drier was evacuated and subsequently charged with diluted elemental fluorine gas (10 vol% F2 in 90 vol% nitrogen; N50, Air Liquide; Miinchen Germany).
• the reactor wall of the tumbling drier was heated to 200 °C, and the reactor was slowly rotated for 30 minutes once the target temperature was reached After the reactor was vented and purged with nitrogen in three cycles, a polymer sample was collected and subjected for end group analysis.
• the copolymer from Illustrative Example 6 was melt pelletized and post-fluorinated in the same manner as described in Example 3 to yield Example 4. The same procedure was applied to the copolymer from Illustrative Example 7 to yield Example 5 with the modification that only 9 fluorination cycles were applied. Properties of the obtained polymers are summarized in Table 5, below.
• FEP 6322Z and FP 6338Z are trade designations for commercial "3M DYNEON” fluoroplastic FEP copolymers from 3M Company, St. Paul, MN.
• DUPONT FEP 9494X is a trade designation for a commercial FEP copolymer from DuPont, Wilmington, Delaware. It contains 1 percent by weight perfluoroethyl vinyl ether as measured according to the method described in U.S. Pat. No. 5,677,404 (Blair).

Landscapes

• Chemical & Material Sciences (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• Engineering & Computer Science (AREA)
• Manufacturing & Machinery (AREA)
• Materials Engineering (AREA)
• Physics & Mathematics (AREA)
• Spectroscopy & Molecular Physics (AREA)
• Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=60293670

Family Applications (1)

Country Status (1)

• 2016
  • 2016-02-12 EP EP16712558.2A patent/EP3257058A1/de not_active Ceased

Similar Documents

Legal Events