Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/06—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material
  • B32B27/08—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material of synthetic resin
• • 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
  • B29C55/00—Shaping by stretching, e.g. drawing through a die; Apparatus therefor
  • B29C55/005—Shaping by stretching, e.g. drawing through a die; Apparatus therefor characterised by the choice of materials
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/32—Layered products comprising a layer of synthetic resin comprising polyolefins
  • B32B27/322—Layered products comprising a layer of synthetic resin comprising polyolefins comprising halogenated polyolefins, e.g. PTFE
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B37/00—Methods or apparatus for laminating, e.g. by curing or by ultrasonic bonding
  • B32B37/08—Methods or apparatus for laminating, e.g. by curing or by ultrasonic bonding characterised by the cooling method
  • B32B37/085—Quenching
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B7/00—Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers
  • B32B7/04—Interconnection of layers
  • B32B7/12—Interconnection of layers using interposed adhesives or interposed materials with bonding properties
• • 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
• • 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
  • B29K2027/00—Use of polyvinylhalogenides or derivatives thereof as moulding material
  • B29K2027/12—Use of polyvinylhalogenides or derivatives thereof as moulding material containing fluorine
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B38/00—Ancillary operations in connection with laminating processes
  • B32B38/0012—Mechanical treatment, e.g. roughening, deforming, stretching
  • B32B2038/0028—Stretching, elongating
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B38/00—Ancillary operations in connection with laminating processes
  • B32B38/0036—Heat treatment
  • B32B2038/0048—Annealing, relaxing
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2250/00—Layers arrangement
  • B32B2250/24—All layers being polymeric
  • B32B2250/242—All polymers belonging to those covered by group B32B27/32
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2307/00—Properties of the layers or laminate
  • B32B2307/50—Properties of the layers or laminate having particular mechanical properties
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2307/00—Properties of the layers or laminate
  • B32B2307/70—Other properties
  • B32B2307/702—Amorphous
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2307/00—Properties of the layers or laminate
  • B32B2307/70—Other properties
  • B32B2307/724—Permeability to gases, adsorption
  • B32B2307/7242—Non-permeable
  • B32B2307/7246—Water vapor barrier
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2327/00—Polyvinylhalogenides
  • B32B2327/12—Polyvinylhalogenides containing fluorine
  • B32B2327/18—PTFE, i.e. polytetrafluoroethylene
• • 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
  • C08J2327/00—Characterised by the use of 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; Derivatives of such polymers
  • C08J2327/02—Characterised by the use of 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; Derivatives of such polymers not modified by chemical after-treatment
  • C08J2327/12—Characterised by the use of 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; Derivatives of such polymers not modified by chemical after-treatment containing fluorine atoms

Definitions

• the present invention relates to
• polytrichlorotrifluoroethylene films film forming compositions, processes for making thermoplastic films featuring improved water vapor barrier properties.
• PCTFE polychlorotrifluoroethylene
• polychlorotrifluoroethylene film forming composition comprising less than about 1% by weight of comonomers, such as ethylenically unsaturated copolymerizable organic monomers.
• comonomers such as ethylenically unsaturated copolymerizable organic monomers.
• Such a film may optionally be further characterized as being highly amorphous and exhibiting a very low water vapor transmission rate, within the range of less than about 0.030 grams per 100 square inches per day at 100oF for a film thickness of 1 mil.
• Such a film may optionally be further
• a process for forming an amorphous PCTFE film from a PCTFE film forming resin having less than about 1% by weight of one or more comonomers and having the characteristics immediately described above which comprises the process steps of:
• PCTFE film forming resin as described above and which is also stretched and annealed as described above.
• the PCTFE film has a degree of
• crystallinity of less than about 60% and which is stretch oriented in a ratio of stretchedrunstretched of between about 2:1 to about 5:1.
• DSC DSC techniques for films of varying compositions containing different quantities of the as a function of the density of a film sample and as a function of the percentages of comonomer, particularly the comonomer vinylidine fluoride within a composition.
• a PCTFE film forming film from a PCTFE film forming resin composition of a PCTFE resin comprising up to 1 percent by weight of an additional comonomers such as ethylenically unsaturated copolymerizable organic monomers which in its final stretched and oriented form has a low degree of crystallinity, viz., less than about 60% crystalline wherein such film is also oriented in the machine direction in the ratio between about 2:1 to about 5:1; more preferably, between about 2:1 to about 5:1, most preferably between about 3:1 and about 4:1 and further wherein such film exhibits a water vapor transmission rate (hereinafter sometimes referred to as "WVTR") of less than about 0.05 grams/100 sq. in. /day for a 1 mil film thickness, preferably less than 0.01 grams/100 sq. in. /day for a 1 mil film thickness.
• WVTR water vapor transmission rate
• a suitable PCTFE film forming resin which may be used in conjunction with the teaching of the present invention may be any PCTFE resin which comprises up to about 1% by weight of comonomers and which may be further characterized as having a zero strength time (sometimes interchangeably referred to as "ZST") of less than about 200, preferably less than about 185 and most preferably about 160 and less.
• ZST zero strength time
• the specification of such a ZST is important to the success of the present invention as it has been found by the inventors that only such film PCTFE film forming resins having such a ZST as specified herein may be successfully oriented and formed into a film having the beneficial features as taught herein.
• the determination of the ZST for the PCTFE film forming resin may be determined in accordance with the method which is more fully described in the
• ASTM-D 1430-81 utilizes a compression molded test sample formed of the PCTFE film forming having dimensions of about 1.6 mm by 4.8 mm by 5.0 mm and which has a dual "v" shaped notch in the central portion of the test sample.
• the sample is suspended from one end with a 7.5 gram weight suspended from the other end in an oven from 250oC.
• the ZST value is the time in seconds after which the sample breaks; the ZST value is known to the art to reasonably correlate to the number average molecular weight of resin used to form the tested sample.
• PCTFE film forming resins include those which have a number average molecular weight of about 1,000,000 and less, preferably about 750,000 and less.
• the number average molecular weight for the PCTFE film forming resin may be correlated from its intrinsic viscosity by well known techniques. Such conventional techniques, for example by determining the intrinsic viscosity of a sample of the resin in a solvent such as 2,5-dichlorobenzyltrifluoride wherein the intrinsic viscosity of the sample may be correlated to the numerical average molecular weight in accordance with the equation:
• Such a suitable PCTFE film forming resin may be produced in accordance with conventional processes for the production of PCTFE film forming resins by
• processes which include a variety of process techniques and a variety of reaction systems. Such processes include bulk polymerization via the utilization of one or more peroxides as an intiating system; aqueous suspension polymerization with redox-initiator systems which include one or more alkali metal persulfates as an oxidant, one or more alkali metal bisulfites as activators, and metal salts as accelerators; emulsion polymerization utilizing fluorocarbon and
• chlorofluorocarbon emulsifiers are also known.
• the molecular weight of the PCTFE film forming resin produced may be controlled by variance of the reactor temperature and pressure, as well as the reaction time in order to produce suitable PCTFE film forming resin.
• reduction-oxidation type reaction comprises the steps of charging a sufficient quantity of the starting reactant pctfe to a glass lined, jacketed, stirred sealable reactor which is capable of operating at least to pressures of about 200 psig. It is preferred that the reactor include a cooling jacket or other cooling means which is capable to withdraw heat from the reactor during the production process and thereby provide a means of temperature control during the reaction of the contents of the reactor.
• the reaction system requires the use of an
• Such an intitiator/catalyst system comprises reduction, oxidation and acceleration constituents wherein the oxidation constituents provide free radicals for the initiation of the polymerization of the CTFE.
• suitable reduction constituents include one or more chemicals selected from the group which
• Suitable oxidation constituents include one or more chemicals selected from the group which includes: hydrogen peroxide, and various metallic persulfates, including sodium persulfate and potassium persulfate, as well as ammonium persulfite.
• Suitable acceleration constituents include one or more chemicals selected from the group which includes: variable valence metal suits such as ferrous sulphate, silver nitrate as well as copper sulfate. Varying ratios of these constituents may be used; i.e. the ratio of the oxidation to the reduction constituents may be varied from 1:1 to 3:1, and the activator may be included in amounts to comprise to 1000 parts per million ("ppm") as well as greater amounts.
• the PCTFE film forming resin may include minor amounts, i.e. generally up to 1% by weight of an ethylene compound containing
• fluoride including: fluorinated ⁇ -olefins, such as hexafluoropropylene, hexafluoroisobutylene, vinylidene fluoride, tetrafluoroethylene, chlorotrifluoroethylene; fluorinated ethers such as perfluoroalkyl vinyl ethers such as perfluoropropyl vinyl ether; perfluoroalkyl ethylenes such as perfluorobutyl ethylene, and the like.
• the films of the present invention may be formed by any conventional film forming technique.
• Such film- forming techniques include but are not limited to the following: formation of films by casting the film onto a casting roll after extrusion through a flat film- forming die, formation of films by the "blown film” technique wherein a film-forming composition is forced through a circular die and the exiting circular film profile is expanded by compressed air, casting a film- forming composition into a billet or other solid form and subsequently skiving the film from said formed billet, as well as other techniques not particularly described here.
• preferred methods for the production of film include film casting
• the thicknesses of the films which are produced by any of the processes outlined above, particularly by the blown film process or by a film casting process may have thicknessess of between 0.001 and 100 mils, preferably of between about 0.05 and 60 mils thickness prior to any stretching operation which will further reduce the film thickeness.
• films may be produced by blown film techniques, as well as by extrusion forming of films wherein the film-forming composition as described above is provided to the inlet of an extruder wherein the action of heat and
• composition plastificates the film and afterwards the composition is forced through a flat film-forming die.
• the film exiting the film-forming die is then quickly contacted with a chilled casting roll which is maintained at a temperature of less than about 100 °F, and preferably less than about 80 oF in order to quench the film and reduce the formation of crystallites within the film.
• the use of mechanical means such as an idler roll, or a plurality of chilled rolls
• other inducement means such as the use of an air knife or air blower
• the PCTFE film removed from the chilled casting roll is an unoriented amorphous film. It may be removed and wound onto a core or spool for storage prior to subsequent processessing, or in the
• PCTFE film may be directly treated in the succeeding process steps.
• the stretching operation to be 25% or less crystalline in nature.
• the film prior to the subsequent stretching operation is less than or equal to about 20% crystalline in nature.
• the crystallinity of the film may be determined by the use of an x-ray diffraction apparatus. Alternatively a differential scanning calorimeter (DSC) may be used. Suitable films in accordance with the present teaching are those which exhibit diffusely scattered x-ray diffraction patterns, evident of a low degree of crystallinity and within the ranges described immediately above.
• a more amorphous film is to be preferred and this may be accomplished by decreasing the temperature of the surface of the chilled casting roll, by decreasing the distance from the exit of the die to the chilled casting roll, or both.
• Tg glass transition temperature
• an acceptable temperature range is between about 160 oF and about 210 °F
• Preheating of the film may be accomplished with any effective means such as contacting the film with at least one heating rol, or with two casting rolls which contact both surfaces of the film simultaneously or in series.
• the film is preheated by at least partially wrapping the film about the surface of at least one heating roll for a
• the preheated film is subsequently subjected to a stretching operation wherein the films of the present invention are stretched in a single direction
• machine direction coinciding with the length of the film (as opposed to its width) which will be referred to as the "machine direction” (MD).
• the film is most desirably stretched so to have a final ratio of stretched film:unstretched film of between about 2:1 to about 5:1; preferably and most preferably the films according to the present invention have a ratio of stretch of between about 3:1 to about 4:1.
• a preferred process for effectuating orientation of the film is by causing the machine direction (MD) orientation of the film by the following process steps.
• the film is preheated to a temperature at least about 10 deg.F above its Tg, preferably between about 160oF to 210oF, after which it is subjected to a first "slow” stretch roller at a further elevated temperature, preferably a temperature of between about 210°F to about 260oF, and subsequently to a "fast” stretch roller at a film temperature which may be same as that during the "slow” stretching, or at different, but preferably lower temperature.
• Both the "slow” and the "fast” stretch rollers are paralleledly rotating heatable rollers having parallel central axes which defines their axis of rotation, such as those which are conventionally used in the art for stretching films.
• the film is first provided to the surface of the rotating slow stretch roller which operates at a peripheral drive speed which is approximately equal to the peripheral drive speed of the last heating roll during the heating operation. In this manner the film is preferably not subjected to any stress or stretching forces prior to the stretching operation described herein.
• the film contacting the surface of the rotating slow stretch roller is
• circumferential speed of the slow stretch roller to the fast stretch roller is between about 1:2 and 1:5.
• the ratio of the circumferential speed of the slow stretch roller to the fast stretch roller is between about 1:3 and 1:4.
• the ratio of the stretch width:stretch length should be less than 1:1, preferably less than 5:1, and most preferably less than about 7.5:1. Subsequent to the stretching operation described above, the film is subjected to an annealing operation wherein the
• stretched film is removed from the "fast" stretch roller and brought into contact with at least one annealling roller which is a temperature above the Tg of the stretched film and which further has a
• the elevated temperature of the annealling roller provides a second heat setting
• the circumferential speed of the at least one annealling roller is up to 50% slower than that of the "fast" stretch roller, and is preferably between about 5% to about 25% slower. It is also generally to be preferred that the temperature of the annealling roller is at least 10°F or more in excess of the Tg of the PCTFE film taught herein, most preferably the temperature of the annealling roller is between about 200°F and about 300°F.
• each of the annealing rollers is to be maintained at a uniform speed relative to each other and within the ranges described immediately above.
• Examples of a plurality of annealling rollers includes but is not limited to: a "stack" of rollers as has been hereintofore described in conjunction with the description of heating rolls above.
• the film may optionally have its edges trimmed and may then be wound onto a core or spool in any manner conventionally used in the art.
• the films taught in the present specification provide good physical characteristics and excellent WVTR barrier characteristics.
• the physical characteristics of the film may be determined in accordance with test protocols which are known to the art and are conventionally used. These include those specified in ASTM material specifications for PCTFE plastics and resins, ASTM D-1430, including the specification for the ZST values ASTM D-1430-8.
• the Scimples are evaluated in both the machine direction and the transverse directions.
• the density of the film forming resin compositions and/or films were determined by the use of a standard density column which utilized as reference fluids , tetrabromopropane ethylene bromide, and 1,3- dibromoethane.
• %cryst 1150 • (density - 2.0) + (5.56 • %VF 2 ) - 92 which equation is derived from experimentally evaluated results using conventional linear regression analytical techniques.
• a representation of the data is
• the three different lines indicate the correlation for three differing film compositions comprising varying amounts of vinylidine fluoride, 3.6%, 1.0% and 0%,
• Determination of the water vapor transmission rate may be evaluated in accordance with conventionally known techniques and includes the use of a Mocon Permatran W-600 apparatus which determines the water vapor transmission rate of a sheet of film at an established temperature; the WVTR values which are provided are normalized to a 100 square inch film sample having a 1 mil thickness of film and the temperature of evaluation was established to be 122°F (50oC); values for the WVTR were also reported as normalized to the temperature of 100°F.
• properties of the film included determination of the dimesional stability of the film; samples of the films were placed in a heated oven having a respective temperature for a set period; the shrinkange in both the machine direction and the transverse direction was then evaluated and the percent shrinkage was
• 10 by 10 inch square film samples were placed in a 300°F oven for 10 minutes, after which the films were removed and the shrinkage in machine direction and the transverse direction was determined.
• the films formed in accordance with the present teaching feature a WVTR value of less than about about 0.030 grams per 100 square inches per day; more
• a WVTR of less than about 0.025 grams per 100 square inches per day based on a film thickness of 1 mil.
• the films taught in the present invention may also be incorporated into multi-layer film structures, which may be produced in accordance with Conventional known techniques such as by co-extrusion or lamination.
• thermoplastic films which may be used in conjunction with the high barrier
• PCTFE film include:
• cellulostic films including cellulose acetate
• ECTFE ethylenechlorotrifluoroethylene copolymer
• ETFE ethylenetetrafluoroethylene copolymer
• FEP fluorinated ethylene-propylene copolymer
• PFA perfluoroalkoxy
• PCTFE polychlorotrifluoroethylene copolymers
• PTFE polytetrafluoroethylene
• PVF polyvinylfluoride
• PVDF polyvinylidene fluoride
• polyamide films including unoriented, monoaxially oriented, or biaxially films, including films including nylon 6, nylon 12 as well as polyamide copolymers and blends of each of the above,
• PC polycarbonate
• PET polyethylene terephthalate
• polyethyene terephthalate/copolymer films such as those
• PET-G conventionally known to the art as "PET-G” type films including KODAR ® films available from the Eastman Kodak Co., polyethylene and polyethylene copolymer films including low density polyethylene (LDPE),
• LDPE low density polyethylene
• MDPE medium density polyethylene
• HDPE high density polyethylene
• Ultrahigh molecular weight polyethylene UHMWPE
• EVA ethylene-vinyl acetate copolymers
• polypropylene (PP) films including cast, unoriented, monoaxially oriented, or biaxially oriented,
• PVC polyvinyl chloride
• the films may formed with or without
• intermediate adhesive layers are also known as "tie layers" to the art and materials which are known to be useful in conjunction with PCTFE films may be used.
• the high barrier PCTFE film taught herein may also be used to form a one or more layers within a multilayer article.
• the films may be used in the production or
• the films of the present invention may also be
• electroluminescent displays electroluminescent displays, electroluminescent lamps, bezels, instrument covers, and the like.
• the films of the present invention are also useful as heat shrinkable films; as is well known to the art such heat shrinkable films find use in a variety of appliations, particularly packaging applications.
• the film forming compositions described hereunder were formed from a plurality of PCTFE film forming resins in accordance with a redox reaction system as generally outlined above.
• the temperature of the reaction was controlled so to remain at a temperature level below that conventionally used for the production of PCTFE materials which have a high ZST value; for the system used the reaction temperature was maintained so as not to exceed about 90 deg.F.
• Particular resin compositions of the Examples included up to about 1% by weight of copolymerized vinylidine fluoride (VF 2 ) which
• Resin compositions are outlined on Table 1.
• Resins #1 - #4 are in accordance with the present invention's teaching.
• Resin #5 is provided for comparative purposes and illustrates compositions according to the prior art.
• the PCTFE resins were formed into films in accordance with the following general process.
• the constituents of a respective composition was provided to the feed inlet of a 2 1/2 inch single screw extruder equipped with a two-stage screw and having a L/D ratio of 24:1.
• the feed rate was 60 lbs/hr
• the temperature of the feed inlet was approximately at 545 deg.F
• the barrel temperature was approximately 500 deg
• the extrudate was metered at about 545 deg.F
• the extrudate was provided to a coathanger type film die having a width of 34 inches and a gap of about 0.045 inches.
• the die temperature was 610 deg.F.
• the die head pressure was about 2500 psi and the extruded film was extruded at a line speed of 8 ft/minute to produce a film of approximately 4 mils thickness.
• the film was laid. onto a casting roll at a temperature of about 50 deg.F and a diameter of 14 inches, and a lay-on roll at the same temperature and having a diameter of 8 inches.
• the lay-on roll was used to assure contact of the film onto the casting roll and to assure rapid quenching.
• the films were then wound onto a core for temporary storage.
• the films were then provided to a stretching apparatus at varying rates of between 15 and 27
• the films were first preheated to a temperature of between 180-190 deg.F, and then provided to a slow stretch roll at a temperature of about 200 deg.F, and subsequently to a fast stretch roll at a temperature of between 180-190 deg.F, and afterwards to a heat set roll at a temperature of 230 deg.F to anneal the stretched film.
• the annealed film was subsequently cooled by contacting the film with a cooled roll at a temperature of about 100 deg.F.
• the films were
• the films exiting the extruder had a thickness of approximately 4 mils prior to the stretch orientation step; subsequent to the stretch orientation the films had a thickness of between about 1.5 and 2 mils
• the PCTFE resins were formed into films in
• the constituents of a respective film forming composition were provided to the feed inlet of a 2 1/2 inch single screw extruder equipped operating substantially in accordance with the conditions outlined above.
• the extrudate was provided to a coathanger type film die to produce a film having a thickness of 12 mils.
• the die temperature was 610 deg.F.
• the die head pressure was about 2500 psi and the extruded film was extruded at a line speed of 3 ft/minute.
• the film was laid onto a casting roll at a temperature of about 50 deg.F and a diameter of 14 inches, and a lay-on roll at the same temperature and having a diameter of 8 inches.
• the lay-on roll was used to assure contact of the film onto the casting roll and to assure rapid quenching.
• the films were then wound onto a core for temporary
• the films were then provided to a stretching apparatus operating at the following parameters.
• the films were first preheated to a temperature of between 180-200 deg.F, and then provided at a linespeed of 20 feet/minute to a slow stretch roll having a peripheral speed of 20 feet/min. and at a temperature of about 210-260 deg.F, and subsequently to a fast stretch roll having a peripheral speed of between 60-80 feet/min. and at a temperature of between 210-250 deg.F, and then subsequently to a heat set roll at a temperature of between 240-270 deg.F and having a peripheral speed of 60-82 feet/minute so to anneal the stretched film.
• the annealed film was subsequently cooled by contacting the film with a cooled roll at a temperature of about 150 deg.F. and rotating at a peripheral speed of 60-82 feet per minute; the films were oriented with varying
• Film compositions were produced substantially in accordance with the method outlined above indicated as Process Example 2. Variations from that process which were used in the instant Process Example included that the casting roll temperature was controlled to be maintained at about 60 deg.F and no lay-on roll was used.
• DSC calorimetric apparatus
• Table 2 which illustrates particular barrier properties and crystallinity of the film. Particular characteristics of the film samples particularly shrinkage
• the film compositions which included compositions of Resin #5 are exemplarly of the prior art.
• the films formed of Resins #1 - Resin #4 include less than 1% by weight of a copolymerizable comonomer, and particular attention is directed to Resin #4 which is seen to consist essentially of a PCTFE hompolymer resin having a ZST value of 127.
• the films according to the invention, F1- F8, and F16-F20 feature excellent water vapor barrier transmission properties as is evidenced from the WVTR values in comparision with a conventional film

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• Medicinal Chemistry (AREA)
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• Shaping By String And By Release Of Stress In Plastics And The Like (AREA)

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• 1992
  • 1992-09-23 JP JP5506339A patent/JPH06511271A/ja active Pending
  • 1992-09-23 EP EP92920886A patent/EP0605610A1/de not_active Withdrawn
  • 1992-09-23 WO PCT/US1992/008062 patent/WO1993006158A1/en not_active Application Discontinuation
  • 1992-09-23 CA CA002118926A patent/CA2118926A1/en not_active Abandoned

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