SE411911B - FORMAT FOREMAL INCLUDING A POLYMER CONSISTING OF AN AROMATIC POLYKETONE - Google Patents

FORMAT FOREMAL INCLUDING A POLYMER CONSISTING OF AN AROMATIC POLYKETONE

Info

Publication number
SE411911B
SE411911B SE7513415A SE7513415A SE411911B SE 411911 B SE411911 B SE 411911B SE 7513415 A SE7513415 A SE 7513415A SE 7513415 A SE7513415 A SE 7513415A SE 411911 B SE411911 B SE 411911B
Authority
SE
Sweden
Prior art keywords
polymer
aromatic polyketone
polymers
foremal
format
Prior art date
Application number
SE7513415A
Other languages
Swedish (sv)
Inventor
K J Dahl
Original Assignee
Raychem Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Raychem Corp filed Critical Raychem Corp
Publication of SE411911B publication Critical patent/SE411911B/en

Links

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
    • C08G61/00—Macromolecular compounds obtained by reactions forming a carbon-to-carbon link in the main chain of the macromolecule
    • 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
    • B29C48/15—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor incorporating preformed parts or layers, e.g. extrusion moulding around inserts
    • 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
    • C08G61/00—Macromolecular compounds obtained by reactions forming a carbon-to-carbon link in the main chain of the macromolecule
    • C08G61/12—Macromolecular compounds containing atoms other than carbon in the main chain of the macromolecule
    • C08G61/127—Macromolecular compounds containing atoms other than carbon in the main chain of the macromolecule derived from carbon dioxide, carbonyl halide, carboxylic acids or their derivatives
    • 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
    • C08G75/00—Macromolecular compounds obtained by reactions forming a linkage containing sulfur with or without nitrogen, oxygen, or carbon in the main chain of the macromolecule
    • C08G75/20—Polysulfones
    • 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
    • H01B3/307—Other macromolecular compounds
    • 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
    • B29C48/05—Filamentary, e.g. strands
    • 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
    • B29C48/06—Rod-shaped

Description

7513415-5 'Patentet 7201872 beskriver smältbèarbetbara polymerer, vilkas återkommande enhet har strukturen ...D - O -<ï;;ï>--CO ~__ vilken kännetecknas därav, att B betecknar en m- eller p-fenylen- grupp eller en enkel bindning och C betecknar väte eller en fenyl- grupp, varvid C är väte, när B är en m- eller p-fenylengrupp. The patent 7201872 describes melt processable polymers, the recurring unit of which has the structure ... D - O - <ï ;; ï> - CO ~ __ which is characterized in that B represents an m- or p-phenylene group or a single bond and C represents hydrogen or a phenyl group, wherein C is hydrogen, when B is an m- or p-phenylene group.

Läget för den "fria" valensen antas sålunda vara i para-ställning på bifenylylgruppens osubstitüerade ring, då syret är bundet till para-ställningen på den andra ringen i förhållande till den direkta bindningen mellan de båda ringarna; då syret är länkat i orto-ställ- ning, antas den fria valensen föreligga i para-ställning i förhållande till syret på den oxi-substituerade ringen. Polymererna kan erhållas vid sådana inre viskositetcr att brottöjningen vid en töjningshastig- het av 200 % per minut vid 25°C är större än ca 50 %, vilket gör dem mera lämpliga för isolerande skikt på elektriskt ledande föremål.The position of the "free" valence is thus assumed to be in the para-position on the unsubstituted ring of the biphenylyl group, as the oxygen is bonded to the para-position on the other ring in relation to the direct bond between the two rings; when the oxygen is linked in the ortho position, the free valence is assumed to be in the para position in relation to the oxygen on the oxy-substituted ring. The polymers can be obtained at such internal viscosities that the elongation at break at an elongation rate of 200% per minute at 25 ° C is greater than about 50%, making them more suitable for insulating layers on electrically conductive objects.

Kristallina polymerer, som framställts enligt uppfinningen, uppnår den smälta fasen vid temperaturer, som ligger väsentligt högre än smält- punkten för poly(bensofenoneter), t.ex. vid temperaturer av storleks- ordningen 70° eller däröver, vilket avsevärt utvidgar det tillgängliga området för högtemperaturapplikationer. De kristallina polymererna 'enligt uppfinningen visade dessutom förbättrad beständighet mot lös- ningsmedel jämfört med poly(bensofenoneter), och de mera amorfa poly- mererna enligt uppfinningen kan tvärbindas i samma syfte. f De lämpliga materialen bildar kristallina homopolymerer. Sampoly- merer kan framställas genom att använda 3'- och/eller 2'-isomerer i mängder, som icke ger mer än 20 % 3'- och/eller 2' återkommande enheter under bibehållande av användbar grad av kristallinitet. Då avsevärd kristallinitet är önskvärd användes lämpligen icke mer än ca 15 % 3' och/eller 2' sammonomcr. I dylika mängder visar sammonomererna benägenhet att minska smältviskositeten, varigenom strängsprutning underlättas. De kristallina homopolymererna enligt uppfinningen har smältpunkter av storleksordningen 700 högre än poly(bensofenoneter), varigenom området för högtemperaturanvändningar utsträckes. I fråga om samtliga polymerer gäller, att den extra fenylgruppen i den åter- kommande bifenylyloxibensoylenheten avsevärt ökar glasöverföringstempe- raturerna. På ett överraskande sätt leder den extra fenylgruppen i 7513415-5 den återkommande enheten till avsevärd förstyvning och att polymeren blir stelare utan att förlängningen pâverkas oförmånligt, vilken är vanligen mer än 100 %- Isoleringen på trådar av kablar måste i all- mänhet ha en förlängning av mer än 50 %, för att det isolerade föremå- let skall kunna lindas omkring sig själv utan att sprickbildning upp- kommer på isoleringen. Detta är även önskvärt i fråga om andra poly- merapplikationer. Polymerer med förlängning mindre än 50 % kan använ- das för övrigt, t.ex. i tekniska plaster, filmer och beläggningar, som anbringas ur lösning genom beläggning eller plasmateknik. Poly- mererna synes vara synnerligen beständiga gentemot ultraviolett ljus, varigenom de kan användas för väderbeständiga beläggningar.Crystalline polymers prepared according to the invention achieve the molten phase at temperatures which are significantly higher than the melting point of poly (benzophenone ethers), e.g. at temperatures of the order of 70 ° or more, which significantly expands the available range for high-temperature applications. In addition, the crystalline polymers of the invention showed improved solvent resistance over poly (benzophenone ethers), and the more amorphous polymers of the invention can be crosslinked for the same purpose. The appropriate materials form crystalline homopolymers. Copolymers can be prepared using 3 'and / or 2' isomers in amounts which do not yield more than 20% of 3 'and / or 2' recurring units while maintaining a useful degree of crystallinity. When considerable crystallinity is desired, no more than about 15% 3 'and / or 2' comonomers are suitably used. In such amounts, the comonomers tend to reduce the melt viscosity, thereby facilitating extrusion. The crystalline homopolymers of the invention have melting points of the order of 700 higher than poly (benzophenone ethers), thereby extending the range of high temperature applications. In the case of all polymers, the extra phenyl group in the recurring biphenylyloxybenzoyl unit significantly increases the glass transfer temperatures. Surprisingly, the extra phenyl group in the recurring unit leads to considerable stiffening and that the polymer becomes stiffer without the elongation being adversely affected, which is usually more than 100% - The insulation on wires of cables must generally have an elongation of more than 50%, so that the insulated object can be wrapped around itself without cracking on the insulation. This is also desirable in the case of other polymer applications. Polymers with elongation less than 50% can be used otherwise, e.g. in technical plastics, films and coatings, which are applied from solution by coating or plasma technology. The polymers appear to be extremely resistant to ultraviolet light, so that they can be used for weather-resistant coatings.

Föreliggande uppfinning avser formade föremål omfattande polyme- rerna sådana de framställs enligt patentet 7201872, i synnerhet elek- triska komponenter isolerade med hjälp av polymererna, i synnerhet elektriska trådar och kablar.The present invention relates to shaped articles comprising the polymers as prepared according to patent 7201872, in particular electrical components insulated by means of the polymers, in particular electrical wires and cables.

Polymererna kan överföras till formade föremål, vilka kan för- stärkas, t.ex. med glasfibrer. Föremålen kan t.ex. utgöras av filmer och fibrer.The polymers can be transferred to shaped objects, which can be reinforced, e.g. with fiberglass. The objects can e.g. consists of films and fibers.

Framställningen av polymererna beskrivs helt och hållet i patent- skriften 7201872.The preparation of the polymers is described in full in patent specification 7201872.

Den smältbearbetbara polymeren kan lätt strängsprutas på elek- triska ledare, oftast när det gäller trådar i form av skikt med tjock- lekar av ca 0,1 till 0,3 mm. 7 Polymerer, vilkas återkommande enheter består av 4-(4'-bifenylyl- oxi)bensoylgrupper är väsentligt mindre lösliga än poly(bensofenone- ter) och följaktligen mera beständiga mot krackelering under inverkan av lösningsmedel. Amorfa polymerer framställda av 4-(3'- och 4-(2'- bifenylyloxi)bensoylmonomerer är något mera lösliga, men kan göras lösningsmedelsbeständiga genom termisk tvärbindning vid temperaturer av ca 300 till 600°C efter strängsprutning på tråd, kabel eller lik- nande. Till och med när kristallin 4,4'-homopolymer strängsprutas på tråd, kan man vinna fördelar genom termisk tvärbindning, och under alla omständigheter kan nötningsbeständigheten, hållfastheten och di- mensionsstabiliteten förbättras genom värmebehandling av sprutade be- läggningsskikt, t.ex. genom att dessa utsätts för temperaturer av ca 250°C under ca 2 minuter. Både värmebehandlingen och den termiska tvärbindningen är givetvis omvänt tids- och temperaturberoende, och lämpliga tider och temperaturer för varje behandling kan lätt utfin- nas av fackmannen med ledning av det föregående, allt beroende på de tillgängliga arbetsbetingelserna och liknande hänsyn.The melt processable polymer can be easily extruded on electrical conductors, usually in the case of wires in the form of layers with thicknesses of about 0.1 to 0.3 mm. Polymers whose recurring units consist of 4- (4'-biphenylyloxy) benzoyl groups are significantly less soluble than poly (benzophenonates) and are consequently more resistant to cracking under the influence of solvents. Amorphous polymers made from 4- (3 'and 4- (2'-biphenylyloxy) benzoyl monomers are slightly more soluble, but can be made solvent resistant by thermal crosslinking at temperatures of about 300 to 600 ° C after extrusion on wire, cable or the like. Even when crystalline 4,4'-homopolymer is extruded on wire, advantages can be obtained by thermal crosslinking, and in any case the abrasion resistance, strength and dimensional stability can be improved by heat treatment of sprayed coating layers, e.g. by exposing them to temperatures of about 250 ° C for about 2 minutes Both the heat treatment and the thermal crosslinking are of course inversely time and temperature dependent, and suitable times and temperatures for each treatment can be readily devised by those skilled in the art in light of the foregoing. , all depending on the available working conditions and similar considerations.

Claims (9)

7513415-s ” PATENTKRAV7513415-s ”PATENT REQUIREMENTS 1. Format föremål, innefattande en polymer bestående av en aro- matisk polyketon, k ä n n e t e o k n a t av att polymeren är en aromatisk polyketon med den återkommande enheten med formeln i ííWïÅ-o-CÄ IA shaped article comprising a polymer consisting of an aromatic polyketone, characterized in that the polymer is an aromatic polyketone having the recurring unit of the formula in the formula I 2. Format föremål enligt krav 1, k ä n n e t e c k n a t av att den återkommande enheten har formeln qïíy©~°~©e°t H2. A shaped object according to claim 1, characterized in that the recurring unit has the formula qïíy © ~ ° ~ © e ° t H 3. Format föremål enligt krav 1 eller 2, k ä n n e t e c k n a t av att polymeren har en förlängning av minst ca 50 %.A shaped article according to claim 1 or 2, characterized in that the polymer has an elongation of at least about 50%. 4. Format föremål enligt krav l - 3,,k ä n n e t e o k n a t av att det innefattar en elektrisk komponent isolerad med ett skikt av polymeren.4. A shaped article according to claims 1-3, characterized in that it comprises an electrical component insulated with a layer of the polymer. 5. S, Format föremål enligt krav 4, k ä n n e t e c k n a t av att komponenten är en elektriskt ledande komponent.5. A shaped object according to claim 4, characterized in that the component is an electrically conductive component. 6. Format föremål enligt krav 5, k ä n n e t e c k n a t av att komponenten är en tråd eller en kabel.A shaped article according to claim 5, characterized in that the component is a wire or a cable. 7. Format föremål enligt något av kraven 4 - 6, k ä n n e - tee c k n a t av att skiktet har en tjocklek av 0,1 - 0,3 mm.Shaped object according to one of Claims 4 to 6, characterized in that the layer has a thickness of 0.1 to 0.3 mm. 8. Format föremål enligt någotfav kraven 1 - 3,_k ä n n e - t e c k n a t av att det föreligger i form av en film eller fiber.Formatted article according to any one of claims 1 - 3, characterized in that it is in the form of a film or fiber. 9. Format föremål enligt något av kraven 1 Q 8,'k ä n n e - t e c k n a t av att polymeren är förstärkt med glasfiber. ÅNFÖRDA PUBLIKATIONER: US 3 441 538 (260-49)Formatted article according to one of Claims 1 to 8, characterized in that the polymer is reinforced with glass fiber. PUBLICATIONS MADE: US 3,441,538 (260-49)
SE7513415A 1971-02-16 1975-11-28 FORMAT FOREMAL INCLUDING A POLYMER CONSISTING OF AN AROMATIC POLYKETONE SE411911B (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US11582471A 1971-02-16 1971-02-16
US21846672A 1972-01-17 1972-01-17

Publications (1)

Publication Number Publication Date
SE411911B true SE411911B (en) 1980-02-11

Family

ID=26813605

Family Applications (2)

Application Number Title Priority Date Filing Date
SE7201872A SE411910B (en) 1971-02-16 1972-02-16 POLYMER PRODUCT, STABLE AT HIGH TEMPERATURES AND STRUCTURABLE, INCLUDING AROMATIC ETERKETON POLYMERS AS A REVERSING UNIT AND PROCEDURE FOR ITS PREPARATION
SE7513415A SE411911B (en) 1971-02-16 1975-11-28 FORMAT FOREMAL INCLUDING A POLYMER CONSISTING OF AN AROMATIC POLYKETONE

Family Applications Before (1)

Application Number Title Priority Date Filing Date
SE7201872A SE411910B (en) 1971-02-16 1972-02-16 POLYMER PRODUCT, STABLE AT HIGH TEMPERATURES AND STRUCTURABLE, INCLUDING AROMATIC ETERKETON POLYMERS AS A REVERSING UNIT AND PROCEDURE FOR ITS PREPARATION

Country Status (10)

Country Link
JP (1) JPS56451B1 (en)
BE (1) BE779458A (en)
CA (1) CA1014696A (en)
CH (1) CH572952A5 (en)
DE (2) DE2228609C2 (en)
ES (1) ES399817A1 (en)
GB (1) GB1383393A (en)
IL (1) IL38769A (en)
IT (1) IT960659B (en)
SE (2) SE411910B (en)

Families Citing this family (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1470049A (en) * 1973-03-21 1977-04-14 Rachem Corp Splicing method and heat-recoverable article
DE3069036D1 (en) * 1979-12-14 1984-09-27 Ici Plc Compositions of aromatic polyetherketones and glass and/or carbon fibres
DE3040849A1 (en) * 1980-10-30 1982-06-09 Hoechst Ag, 6000 Frankfurt METHOD FOR THE PRODUCTION OF DIPHENYL ETHERS
US4912195A (en) * 1983-03-31 1990-03-27 Raychem Corporation Preparation of aromatic polymers using a specified quantity of Lewis acid
US4879366A (en) * 1983-03-31 1989-11-07 Raychem Corporation Preparation of aromatic oligomers
US4721771A (en) * 1983-03-31 1988-01-26 Raychem Corporation Preparation of aromatic polymers
BR8406499A (en) * 1983-03-31 1985-03-12 Raychem Corp PREPARATION OF AROMATIC POLYMERS
US4698393A (en) * 1983-03-31 1987-10-06 Raychem Corporation Preparation of poly(arylene ether ketones)
US4709007A (en) * 1983-03-31 1987-11-24 Raychem Corporation Preparation of aromatic polymers
US4820571A (en) * 1983-07-12 1989-04-11 Asten Group, Inc. High temperature industrial fabrics
GB8319510D0 (en) * 1983-07-19 1983-08-17 Bicc Plc Insulated wires and cables
US4650228A (en) * 1983-09-14 1987-03-17 Raychem Corporation Heat-recoverable coupling assembly
CA1248799A (en) * 1984-02-23 1989-01-17 Asten, Inc. Abrasion and hydrolysis resistant joining wire and coil material for fabric seams
GB2190041A (en) * 1986-03-11 1987-11-11 Raychem Ltd Reinforced polymer composite
US4841013A (en) * 1986-09-18 1989-06-20 Raychem Limited Preparation of poly(arylene ether ketones)
GB8623511D0 (en) * 1986-09-30 1986-11-05 Raychem Ltd Arylene cligomers
GB8725886D0 (en) * 1987-11-04 1987-12-09 Raychem Ltd Poly(ar-lene ether ketones)
DE3829520A1 (en) * 1988-08-31 1990-03-01 Basf Ag METHOD FOR PRODUCING POLYARYLENETHERKETONES
WO2019142942A1 (en) 2018-01-22 2019-07-25 Dic株式会社 Polyarylene ether ketone resin and production method thereof, and molded body

Also Published As

Publication number Publication date
DE2228609C2 (en) 1984-10-31
ES399817A1 (en) 1975-06-16
IL38769A0 (en) 1972-05-30
CH572952A5 (en) 1976-02-27
IL38769A (en) 1975-11-25
DE2206836A1 (en) 1972-12-14
SE411910B (en) 1980-02-11
DE2228609A1 (en) 1973-12-13
IT960659B (en) 1973-11-30
DE2206836C2 (en) 1983-03-17
CA1014696A (en) 1977-07-26
BE779458A (en) 1972-08-16
JPS56451B1 (en) 1981-01-08
GB1383393A (en) 1974-02-12

Similar Documents

Publication Publication Date Title
SE411911B (en) FORMAT FOREMAL INCLUDING A POLYMER CONSISTING OF AN AROMATIC POLYKETONE
US3179635A (en) Linear polymeric amide-modified polyimides and process of making same
US5115082A (en) Fluorinated poly(arylene ether)
WO2014163352A1 (en) Polyimide cover substrate
US3168417A (en) Polyimide coated fluorocarbon insulated wire
JPH0146843B2 (en)
US3355427A (en) Polyimides of a bis-(trimellitate) dianhydride and a diamine
US5108840A (en) Multilayer electronic circuit article having a poly(naphthyl ether) dielectric
US3036990A (en) Wholly aromatic polyesters from hydroquinone, isophthalic and terephthalic acid reactants
JPS63139035A (en) Manufacture of polymer protection layer on light guide path
US3440215A (en) Aromatic polyimides
US5145936A (en) Fluorinated poly (naphthyl ether)
US3583939A (en) Crosslinking of aromatic polymers with organic polysulfonazides
WO2012111985A2 (en) Cables including insulating layer containing non-crosslinked resin
US3306771A (en) Plural ester-imide resins on an electrical conductor
US4921758A (en) Molded product of polyarylene thioether and the use thereof
US3371009A (en) Aromatic polyimide laminates and methods of producing such laminates
KR102014740B1 (en) Polyarylene resins
EP0419519B1 (en) Hexafluoroisopropylidene-containing polyimide oligomers and polymers
US3855184A (en) Crosslinking of aromatic polymers with organic polysulfonazides
US3036992A (en) Amorphous aromatic polyester containing no aliphatic chain units
JPH01122506A (en) Heat-resistant electric wire or cable
US3770696A (en) Crosslinking of armomatic polycarbonates with organic polysulfonazides
KR870004466A (en) Crosslinked polymer products
CN110628218A (en) Fluorine-containing polyimide/fluorinated ethylene propylene lubricating composite membrane and preparation method thereof

Legal Events

Date Code Title Description
NUG Patent has lapsed

Ref document number: 7513415-5

Effective date: 19920306

Format of ref document f/p: F