Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G73/00—Macromolecular compounds obtained by reactions forming a linkage containing nitrogen with or without oxygen or carbon in the main chain of the macromolecule, not provided for in groups C08G12/00 - C08G71/00
  • C08G73/06—Polycondensates having nitrogen-containing heterocyclic rings in the main chain of the macromolecule
  • C08G73/10—Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors
  • C08G73/14—Polyamide-imides
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
  • B29C48/022—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor characterised by the choice of material
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
  • B29C48/03—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor characterised by the shape of the extruded material at extrusion
  • B29C48/07—Flat, e.g. panels
  • B29C48/08—Flat, e.g. panels flexible, e.g. films
• • 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
  • C08J5/18—Manufacture of films or sheets
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L79/00—Compositions of macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing nitrogen with or without oxygen or carbon only, not provided for in groups C08L61/00 - C08L77/00
  • C08L79/04—Polycondensates having nitrogen-containing heterocyclic rings in the main chain; Polyhydrazides; Polyamide acids or similar polyimide precursors
  • C08L79/08—Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
  • B29K2079/00—Use of polymers having nitrogen, with or without oxygen or carbon only, in the main chain, not provided for in groups B29K2061/00 - B29K2077/00, as moulding material
  • B29K2079/08—PI, i.e. polyimides or derivatives thereof
  • B29K2079/085—Thermoplastic polyimides, e.g. polyesterimides, PEI, i.e. polyetherimides, or polyamideimides; Derivatives thereof
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
  • B29K2105/00—Condition, form or state of moulded material or of the material to be shaped
  • B29K2105/25—Solid
  • B29K2105/253—Preform
  • B29K2105/256—Sheets, plates, blanks or films
• • 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
  • C08J2379/00—Characterised by the use of macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing nitrogen with or without oxygen, or carbon only, not provided for in groups C08J2361/00 - C08J2377/00
  • C08J2379/04—Polycondensates having nitrogen-containing heterocyclic rings in the main chain; Polyhydrazides; Polyamide acids or similar polyimide precursors
  • C08J2379/08—Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors

Definitions

• This invention relates to a process for extruding a thin film from an aromatic polyamide-imide composition.
• High temperature thin films, and especially high temperature very thin films, are currently dominated by polyimides such as KAPTON ® grades. They are produced by a solution cast process and need the use of organic solvents. It is well known that the skilled in the art dislikes the use of organic solvents.
• a solvent-free alternative was proposed by Emery et al. (US 4,581,264), which consisted in extruded polyamide-imide films. While successful to a certain extent, it proved unsuccessful in certain other cases, notably when very thin films had to be made from polymer compositions that have a very high polyamide-imide content, i.e. those which in practice offer the most attractive properties, as detailed in U.S. 4,581,264.
• US 4,581,264 describes a process for extruding various articles from an aromatic polyamide-imide composition through melt channels and extrusion dies at continuously increasing shear rates and at temperatures of about 575 0 F to about 680 0 F.
• melt channels and extrusion dies at continuously increasing shear rates and at temperatures of about 575 0 F to about 680 0 F.
• thin or thick sheets, thick tubes and thin films are examples of thin or thick sheets, thick tubes and thin films.
• Example 1 describes the manufacture of a film having a thickness of 6.5 mils by extruding a neat polyamide-imide polymer.
• the film of example 2 which has a lower thickness (namely, 3 mils) was not extruded from a neat polyamide-imide polymer, but from a 80:20 blend of a polyamide-imide polymer and of a ULTEM ® polyetherimide.
• ULTEM ® polyetherimides exhibit usually a much lower level of properties than polyamide-imides but act as processing aids; thus, that the use of a ULTEM ® polyetherimide in example 2, although being detrimental to the properties, was in fact required to extrude successfully a film as thin as 0.003 inches based on the extrusion process taught in US 4,581,284.
• a certain aspect of the present invention is directed to a process for extruding a film (F) having a thickness of below 1000 ⁇ m from a polymer composition (C), wherein the polymer composition (C) comprises at least
• Such process enables to obtain polyamide-imide films of improved quality, in particular good looking polyamide-imide films as thin as 25 ⁇ m which have a very high polyamide-imide content (typically above 85 wt. %), while not requiring the use of solvents.
• Another aspect of the present invention concerns a film obtainable by the process as above described.
• An aspect of the present invention of particular interest is directed to a process for extruding a film (F) having a thickness of below 1000 ⁇ m from a polymer composition (C), wherein the polymer composition (C) comprises at least 40 wt. %, based on the total weight of the polymer composition (C), of at least one aromatic polyamide-imide manufactured by a process including the polycondensation reaction between (i) an acid monomer combination of a trimellitic anhydride monoacid halide with trimellitic acid, and (ii) at least one comonomer chosen from diamines and diisocyanates, wherein the trimellitic acid amount is above 2 mol. %, based on the total number of moles of acid monomer.
• the local thickness ⁇ associated to a material point of coordinates (x,y,z), is defined as the length of the shortest straight line D including the material point of concern, which goes right through the film (F) (i.e. which goes from the material point where D enters the film (F) to the material point where D exits the film (F)).
• the thickness of the film (F) is preferably of below 100 ⁇ m, more preferably less than 75 ⁇ m, still more preferably less than 55 ⁇ m, even still more preferably less than 40 ⁇ m and the most preferably less than 30 ⁇ m. Besides, the thickness of the film (F) is advantageously greater than 10 ⁇ m, preferably greater than 15 ⁇ m and more preferably greater than 20 ⁇ m.
• an "aromatic polyamide-imide” is intended to denote any polymer comprising more than 50 wt. % of recurring units comprising at least one aromatic ring, at least one imide group, as such and/or in its amic acid form, and at least one amide group which is not included in the amic acid form of an imide group [recurring units (Rl)].
• the aromatic polyamide-imide comprises more than 90 wt. % of recurring units (Rl). More preferably, it contains no recurring unit other than recurring units (Rl).
• the recurring units (Rl) are advantageously :
• Recurring units (Rl) are preferably chosen from :
• Recurring units (Rl) are very preferably a mix of recurring units (ii) and (iii).
• aromatic polyamide-imides consisting of a mix of recurring units (ii) and (iii).
• Polymers commercialized by Solvay Advanced Polymers as TORLON ® polyamide-imides comply with this criterion.
• the aromatic polyamide-imide used in the process of the present invention is manufactured by a process including the polycondensation reaction of : (i) trimellitic anhydride monoacid halide; (ii) at least one comonomer chosen from diamines and diisocyanates, and (iii) at least one substance (S) comprising one and only one functional group capable of reacting with either an anhydride group and an acid halide group on one hand, or an amine group and an isocyanate group on the other hand, or one and only one precursor of said functional group, wherein the amount of substance (S) is above 1 mol. %, based on the total number of moles of trimellitic anhydride monoacid halide and substance (S).
• trimellitic anhydride monoacid halide 4-trimellitoyl anhydride chloride is preferred.
• the comonomer comprises preferably at least one aromatic ring. Besides, it comprises preferably at most two aromatic rings.
• the comonomer is preferably a diamine.
• diamines it can be cited : paraphenylene diamine, benzidine, 4-[(4-aminophenyl)methyl]aniline.
• the diamine is chosen from the group consisting of 4,4'- diaminodiphenylmethane, 4,4'-diaminodiphenylether, m-phenylenediamine and mixtures thereof.
• Substance (S) comprises one and only one functional group capable of reacting with either an anhydride group and an acid halide group on one hand, or an amine group and an isocyanate group on the other hand, or a precursor of said functional group.
• substances (S) comprising one and only one functional group capable of reacting with an anhydride group and an acid halide group
• substances (S) comprising one and only one functional group capable of reacting with an anhydride group and an acid halide group
• aniline, napthylamine, anisidine and phenyl isocyanate it can be cited aniline, napthylamine, anisidine and phenyl isocyanate.
• substances (S) comprising one and only one functional group capable of reacting with an amine group and an isocyanate group
• phthalic anhydride 1,8-naphthalic anhydride, 1,2-cyclohexenedicarboxylic anhydride (cis or trans), succinic anhydride, maleic anhydride, benzoic anhydride, benzoyl chloride and naphthoyl chloride.
• substances (S) comprising one and only one precursor of a functional group capable of reacting with an amine group and an isocyanate group
• substances (S) comprising one and only one precursor of a functional group capable of reacting with an amine group and an isocyanate group
• any substance comprising two vicinal carboxylic acids in particular trimellitic acid and maleic acid.
• Substance (S) comprises preferably one and only one functional group capable of reacting with an amine group and an isocyanate group, or one and only one precursor of said functional group.
• Substance (S) comprises more preferably one and only one precursor of a functional group capable of reacting with an amine group and an isocyanate group.
• Substance (S) may be aliphatic or aromatic. It is preferably aromatic.
• the most prefered substance (S) is trimellitic acid. Excellent results were obtained when trimellitic acid was used as the sole substance (S).
• the amount of substance (S), in particular the amount of trimellitic acid, is preferably above 1 ,5 %, more preferably above 2 %, and still more preferably above 2.5 % by mole, based on the total number of moles of trimellitic anhydride monoacid halide and substance (S).
• the amount of substance (S) is advantageously below 25 %, preferably below 15 %, more preferably below 10 %, still more preferably 8 % by mole, based on the total number of moles of trimellitic anhydride monoacid halide and substance (S).
• the aromatic polyamide-imide has an intrinsic viscosity (IV) which is advantageously below 0.60, preferably below 0.55 and more preferably below 0.50. Besides, it is advantageously above 0.20, preferably above 0.25 and more preferably above 0.30. Intrinsic viscosities measurements are operated on a Schott Gerate Viscometer Instrument (AVS 440) using 1 -methyl-2-pyrrolidinone (NMP) at 25°C following ASTM D2857, ASTM D5336 and ASTM D52251.
• the aromatic polyamide-imide has an average molecular weight (Mw) which is advantageously below 40,000, preferably below 35,000 and more preferably below 30,000 g/mol. Besides, it is advantageously above 10,000, preferably above 12,000 and more preferably above 15,000 g/mol, as determined by GPC at room temperature in a solution of DMF containing 0.1M LiBr
• the polymer composition (C) comprises at least 40 wt. % based on the total weight of the polymer composition (C), of at least one aromatic polyamide- imide.
• the aromatic polyamide-imide is contained in polymer composition (C) in an amount of preferably above 85 wt. %, more preferably above 90 wt. %, still more preferably above 95 wt. % and the most preferably above 99 wt. %, based on the total weight of polymer composition (C).
• the external lubricant The polymer composition (C) comprises preferably an external lubricant.
• Any external lubricant is in principle suitable as long as it has no detrimental effect on the process and the extruded film there from.
• the external lubricant is preferably a fluorocarbon polymer.
• a fluorocarbon polymer is intended to denote any polymer of which more than 50 mol. % of the recurring units are derived from at least one ethylenically unsaturated monomer comprising at least one fluorine atom (hereafter, “the fluorinated monomer”), based on the total number of moles of recurring units.
• the fluorocarbon polymer comprises preferably more than 75 wt. %, more preferably more than 90 wt. % of recurring units derived from fluorinated monomers, and still more preferably more than 97 wt. % of recurring units derived from fluorinated monomers, based on the total number of moles of recurring units.
• the fluorocarbon polymer advantageously comprises recurring units derived from vinylidene fluoride (VF 2 ) or from tetrafluoroethylene (TFE).
• the fluorocarbon polymer consists of recurring units derived from vinylidene fluoride (VF 2 ) or from tetrafluoroethylene (TFE), and at least one other fluorinated monomer other than VF 2 or TFE, depending on whether VF 2 or TFE is used as the base monomer.
• VF 2 vinylidene fluoride
• TFE tetrafluoroethylene
• the other fluorinated monomer can be notably vinylidene fluoride (or VF 2 , when TFE is used as the base monomer); trifluoroethylene; chlorotrifluoroethylene (CTFE); 1 ,2-difluoroethylene; tetrafluoroethylene (or TFE, when VF 2 is used as the base monomer); hexafluoropropylene (HFP); octafluorobutene; perfluoro(alkyl vinyl) ethers, such as perfluoro(methyl vinyl) ether (PMVE), perfluoro(ethyl vinyl) ether (PEVE) and perfluoro(propyl vinyl) ether (PPVE); perfluoro(l,3-dioxole); perfluoro(2,2-dimethyl- 1 ,3-dioxole) (PDD); the product of formula
• PFBE perfluorobutylethylene
• the external lubricant is a homopolymer of tetrafluoroethylene or a copolymer of which the recurring units are derived from vinylidene fluoride (VF 2 ) and from hexafluoropropylene (HFP).
• VF 2 /HFP copolymer consists of preferably at least 50 %, more preferably at least 60 % by moles of VF 2 , and preferably at most 30 %, more preferably at most 40 % by moles of HFP based on the total number of moles of recurring units.
• the VF 2 /HFP copolymer consists of preferably at most 95 %, more preferably at most 85 % by moles of VF 2 and preferably at least 5 % and more preferably at least 15 % by moles of HFP based on the total number of moles of recurring units.
• the external lubricant in particular the fiuorocarbon polymer, is contained in polymer composition (C) in an amount of preferably at least 0.1 wt. %, and more preferably at least 0.3 wt. %, based on the total weight of the polymer composition. Besides, it is preferably contained in polymer composition (C) in an amount of preferably at most 2 wt. %, and more preferably at most 1 wt. %, based on the total weight of the polymer composition.
• the external lubricant has an average molecular weight in number of preferably below 700, 000 (as determined by conventional GPC technique).
• the external lubricant, in particular the fiuorocarbon polymer is preferably homogeneously distributed in the matrix formed by polymer composition (C).
• the polymer composition (C) may comprise other usual additives of aromatic polyamide-imide compositions, insofar as their nature and their amount does not impair the desired properties.
• additives comprise adhesion promoters, antioxidants, antistatic agents, carbon black, carbon fibers, compatibilizers, curing agents, dyes, extending fillers, fire retardants, glass fibers, metal particles, mold release agents, pigments, plasticizers, reinforcing fillers, rubbers, silica, smoke retardants, tougheners, UV absorbers, and the like, and mixtures thereof.
• the polymer composition (C) comprises generally from 0 to 5 wt. % of at least one solvent of the aromatic polyamide-imide.
• solvent of the aromatic polyamide-imide intend to denote a substance, usually a liquid, capable of dissolving the aromatic polyamide-imide.
• Typical solvents of the aromatic polyamide-imides according to the present invention are l-methyl-2- pyrrolidinone (NMP), dimethylacetamide (DMAc), dimethylformamide (DMF), dimethylsulfoxide (DMSO) or other dipolar aprotic solvents.
• NMP has to be heated around 100 0 C to dissolve aromatic polyamide-imides, but once dissolved, the solution can be cooled without any effect on the solubility of the polymer.
• the polymer composition (C) is essentially free of solvent. Very preferably, it is free of solvent. The extrusion process.
• the film (F) is usually extruded with an extruder, said extruder comprising a barrel and an extrusion die.
• the extruder may comprise a single barrel, or, more often, a plurality of barrels.
• the process according to the present invention comprises preferably the steps of : (i) feeding the polymer composition (C) into a the feed end of the barrel of the extruder.
• Both single- and twin-screw extruders can give good results.
• powdered or pelletized polymer and possibly other materials such as fillers, additives and external lubricants are delivered to a hopper and from there fed into the feed end of a barrel in which the material is conveyed forward as it is mixed.
• the polymer composition (C) is preferably fed into the extruder at a feed rate of above 7 lb/hr (3.17 kg/hr); besides the feed rate does not preferably exceed 12 lb/hr (5.44 kg/hr). Screws with compression ratio of 1:1 to 3:1 can be used successfully for film extrusion process without significant differences.
• Both starve feeding and flood feeding can be used advantageously to make films as thin as 1 mil (25.4 ⁇ m).
• the film extruder screw runs preferably above 10 rpm, and more preferably above 14 rpm.
• the materials are plasticized by the frictional heat generated by the rotating screw(s) of the extruder and external heat applied through the barrel.
• the barrel temperature of the extruder is advantageously above 250 0 C, preferably above 300 0 C and more preferably above 325°C.
• the die temperature is in general of at least 680 0 F (360.0 0 C), but when the die temperature is above 730 0 F (387.8°C), the material often starts to decompose.
• the die temperature of the extrusion die is advantageously less than 730 0 F (387.8°C) and preferably less than 705 0 F (373.9°C).
• the temperature of the extrusion die is advantageously above 645°F (340.5 0 C) and preferably above 670 0 F (354.4°C).
• the pressure of the extrusion die is generally comprised between 700 and 2500 psi (48.3 and 172.4 bars).
• the melted material enters the final extrusion die which gives generally the film its form. It is also preferred to adjust the die adaptor, so as to reduce residence time between screw tip and die.
• Solidifying is usually caused by cooling.
• the film can be cooled by many ways. It is preferably air-cooled.
• the process advantageously further comprises a step prior to the step (i) of feeding the polymer composition (C) into the extruder, consisting in pelletizing the polymer composition (C). During this step, it is advantageous to run the extruder at low rate, preferably below 60 rpm.
• the present invention concerns a film obtainable by the process as above described.
• Such film can notably be obtained by extrusion, using different types of extruder, notably a twin-screw or a single-screw extruder.
• the film obtainable by the process according to the present invention is preferably identical to film (F) and complies very preferably with all the preferred characteristics of film (F), whatever the level of preference, notably as concerns its thickness.
• Such a film may also be obtained by other processes while maintaining the same or substantially the same characteristics featured by the film (F)
• the films (F) manufactured by the invented process or films obtainable by such process are useful in a huge number of applications, including electrical and electronic insulation applications, such as wire and cable tapes, substrates for flexible printed circuits, motor slot liners, magnet wire insulation, transformer and capacitor insulation, etc. They can also be used for friction and wear applications, such as metal-polymer bushings and bearings.
• An outstanding advantage of the process according to the present invention is that it makes it possible to high quality extruded very thin films (as thin as 25 ⁇ m) from a polymer composition comprising well above 80 wt. % of aromatic polyamide-imide which is essentially free of solvent. Such beneficial merits were not achievable by any prior art extrusion process.
• Aromatic polyamide-imide (PAI) powders manufactured by a process including the polycondensation reaction of trimellitic acid chloride, 4,4'-diaminodiphenylether and m-phenylenediamine, and trimellitic acid. Three grades (PAI 1, PAI 2 and PAI 3) were prepared, differing only by the amount of trimellitic acid ;
• ⁇ PTFE DyneonTM PA5956 a homopolymer of tetrafluoroethylene, commercially available from 3M ;
• Tecnoflon ® NM a fluoroelastomer made OfVF 2 ZHFP copolymer, commercially available from Solvay Solexis ;
• samples were prepared in the form of pellets on a Berstorff B extruder, using the same pelletizing compounding conditions as follows :
• films obtained according to the invention featured some anisotropic properties (see table 4). Properties such as tensile strength, tensile elongation and tensile modulus along the machine direction (MD) were better than those in the transverse direction (TD).

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• Medicinal Chemistry (AREA)
• Organic Chemistry (AREA)
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• Manufacturing & Machinery (AREA)
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• Extrusion Moulding Of Plastics Or The Like (AREA)
• Compositions Of Macromolecular Compounds (AREA)
• Manufacture Of Macromolecular Shaped Articles (AREA)
• Macromolecular Compounds Obtained By Forming Nitrogen-Containing Linkages In General (AREA)

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• 2006
  • 2006-11-09 EP EP06819376A patent/EP1951496A1/de not_active Withdrawn
  • 2006-11-09 WO PCT/EP2006/068304 patent/WO2007054543A1/en active Application Filing
  • 2006-11-09 JP JP2008539437A patent/JP2009515020A/ja active Pending

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