EP0074281B1 - Heating diesel fuel - Google Patents

Heating diesel fuel Download PDF

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Publication number
EP0074281B1
EP0074281B1 EP82304744A EP82304744A EP0074281B1 EP 0074281 B1 EP0074281 B1 EP 0074281B1 EP 82304744 A EP82304744 A EP 82304744A EP 82304744 A EP82304744 A EP 82304744A EP 0074281 B1 EP0074281 B1 EP 0074281B1
Authority
EP
European Patent Office
Prior art keywords
head
diesel fuel
polyvinylidene fluoride
composition
inch
Prior art date
Legal status (The legal status 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 status listed.)
Expired
Application number
EP82304744A
Other languages
German (de)
English (en)
French (fr)
Other versions
EP0074281A1 (en
Inventor
Peter Van Konynenburg
Andrew Au
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Raychem Corp
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
Priority to AT82304744T priority Critical patent/ATE35745T1/de
Publication of EP0074281A1 publication Critical patent/EP0074281A1/en
Application granted granted Critical
Publication of EP0074281B1 publication Critical patent/EP0074281B1/en
Expired legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
    • H01B1/20—Conductive material dispersed in non-conductive organic material
    • H01B1/24—Conductive material dispersed in non-conductive organic material the conductive material comprising carbon-silicon compounds, carbon or silicon
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01C—RESISTORS
    • H01C7/00—Non-adjustable resistors formed as one or more layers or coatings; Non-adjustable resistors made from powdered conducting material or powdered semi-conducting material with or without insulating material
    • H01C7/02—Non-adjustable resistors formed as one or more layers or coatings; Non-adjustable resistors made from powdered conducting material or powdered semi-conducting material with or without insulating material having positive temperature coefficient
    • H01C7/027—Non-adjustable resistors formed as one or more layers or coatings; Non-adjustable resistors made from powdered conducting material or powdered semi-conducting material with or without insulating material having positive temperature coefficient consisting of conducting or semi-conducting material dispersed in a non-conductive organic material
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B3/00—Ohmic-resistance heating
    • H05B3/10—Heating elements characterised by the composition or nature of the materials or by the arrangement of the conductor
    • H05B3/12—Heating elements characterised by the composition or nature of the materials or by the arrangement of the conductor characterised by the composition or nature of the conductive material
    • H05B3/14—Heating elements characterised by the composition or nature of the materials or by the arrangement of the conductor characterised by the composition or nature of the conductive material the material being non-metallic
    • H05B3/146—Conductive polymers, e.g. polyethylene, thermoplastics
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
    • F02B3/00—Engines characterised by air compression and subsequent fuel addition
    • F02B3/06—Engines characterised by air compression and subsequent fuel addition with compression ignition

Definitions

  • This invention relates to a method of heating diesel fuel using a conductive polymer composition.
  • Electrical devices containing conductive polymers generally (though not invariably) comprise an outer jacket, usually of insulating material, to protect the conductive polymer from damage by the surrounding environment.
  • an outer jacket usually of insulating material
  • the jacket is permeable to harmful species in the environment, or if the conditions of use are such that the jacket may become damaged, it is necessary or desirable to select a conductive polymer which is not damaged (or which deteriorates at an acceptably low rate) when exposed to the surrounding environment.
  • Exposure of conductive polymers to organic fluids generally results in an increase in resistivity; exposure to air, especially at elevated temperatures between room temperature and 35°C below the melting point generally results in a decrease in resistivity both at the elevated temperature and at room temperature (a phenomenon known in the art as "resistance relaxation").
  • conductive polymer compositions which are based on polyvinylidene fluoride exhibit substantially improved stability of the polyvinylidene fluoride has a very regular structure which can be characterized by a low head-to-head content in the repeating units.
  • Polyvinylidene fluoride is made up of repeating units of formula -CH 2 CF 2 -, which can be arranged head-to-tail (i.e. ⁇ CH 2 CF 2 ⁇ CH 2 CF 2 ⁇ ), or head-to-head (i.e.
  • a method of heating diesel fuel which comprises passing current through a self-regulating heater that has no outer protective jacket, which heater
  • Polyvinylidene fluorides suitable for use in this invention are commercially available.
  • the head-to-head content of a polyvinylidene fluoride can be measured by those skilled in the art. We have found that the measured head-to-head contents of different samples of a polymer sold under a particular trade name can differ substantially.
  • the presently available polyvinylidene fluorides made by suspension polymerization (rather than emulsion polymerization) have lower head-to-head contents.
  • the number average molecular weight of the polymer is generally at least 5,000, e.g. 7,000 to 15,000.
  • the polyvinylidene fluoride is preferably a homopolymer of vinylidene fluoride, but the presence of small quantities of comonomers, (preferably less than 15%, particularly less than 5% by weight), e.g. tetrafluoroethylene, hexafluoropropylene and ethylene, is not excluded.
  • the polyvinylidene -fluoride is preferably the sole crystalline polymer in the composition, but other crystalline polymers, e.g. other crystalline fluoropolymers, may also be present.
  • the composition may contain relatively small amounts (preferably less than 35%, especially less than 20%, particularly less than 10%, by volume) of one or more elastomeric polymers, particularly solvent-resistant fluorine-containing elastomers and acrylic elastomers, which are usually added primarily to improve the flexibility and elongation of the composition.
  • the particulate conductive filler preferably comprises carbon black, and often consists essentially of carbon black. Choice of the carbon black will influence the resistivity/temperature characteristics of the composition, and a carbon black having a ratio of surface area (m 2 /g) to particle size (nanometers) of 0.03 to 6.0 is preferred.
  • the amount of conductive filler used will depend upon the desired resistivity of the composition. For flexible strip heaters which are to be powered by a 12 volt battery for heating diesel fuel, we prefer a PTC composition whose resistivity at 25°C is less than 200 ohm - cm e.g. about 10 to about 100 ohm - cm. In such compositions the amount of carbon black may for example be 16 to 25% by weight.
  • compositions used in the method of the invention may also comprise other conventional additives, such as non-conductive fillers (including flame retardants), antioxidants and crosslinking agents (or residues thereof if the composition has been cross-linked).
  • non-conductive fillers including flame retardants
  • antioxidants include antioxidants and crosslinking agents (or residues thereof if the composition has been cross-linked).
  • compositions used in the method of the invention are preferably cross-linked (particularly by irradiation), since this has been found to enhance their resistance to organic solvents.
  • compositions used in the method of the invention can be carried out in a conventional fashion. Often it will be convenient to melt-extrude the composition directly into a water bath (which may be heated), and using this technique subsequent annealing is often not required.
  • composition A The ingredients listed for Composition A in Table 1 below were mixed in a Banbury mixer. The mixture was dumped, placed on a steam-heated mill and extruded into a water bath through a 3.5 inch (8.9 cm) extruder fitted with a pelletizing die. The extrudate was chopped into pellets which were dried for 16 hours at 80°C.
  • composition B The ingredients listed for Composition B in Table 1 were mixed and pelletized in the same way as for Composition A.
  • the composition of the resulting Final Blend is shown in Table 1.
  • Table 1 Using a 1.5 inch (3.8 cm) diameter extruder fitted with a crosshead die having an orifice 0.4 inch (1.0 cm) ⁇ 0.1 inch (0.3 cm), the blend was melt-extruded over a pair of pre-heated 14 AWG (1.85 mm diameter) 19/27 nickel-coated copper wires with a center-to-center separation of 0.25 inch (0.64 cm) - m.
  • the extrudate was passed immediately through a bath of water at room temperature, air-dried, and then irradiated to a dosage of 10 Mrad.
  • the conductive polymer had a resistivity of about 50 ohm. cm at 25°C.
  • the extrudates obtained in Examples 1 to 6 were compared in the following way. Samples 2 inch (5.1 cm) long were cut from the extrudates and were immersed in various test liquids maintained at 160°F (71°C). The test liquids are listed below and include diesel fuel and various commercially available additives for diesel fuel alone and mixed with diesel fuel. At intervals, the samples were removed, cooled to 25°C and dried, and their resistance measured. Table 3 shows the value of the ratio R f /R i for the different samples at various times. The additives tested, and their main ingredients, were as follows:
  • compositions of Examples 7-15 were tested by the following tests. Samples 1 inch (2.54 cm) by 1.5 inch (3.8 cm) were cut from the molded slabs. Electrodes were formed on each sample by painting a strip 0.25 inch (0.62 cm) wide at each end with a suspension of silver particles (Electrodag 504 available from Acheson Colloids). The samples were annealed for 5 minutes at 200°C, and then cooled. The samples were then placed in an oven at 100°C and their resistances measured at intervals. It was found at the lower the head-to-head content of the polymer, the less its change in resistance.

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Chemical & Material Sciences (AREA)
  • Dispersion Chemistry (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Electromagnetism (AREA)
  • Ceramic Engineering (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Compositions Of Macromolecular Compounds (AREA)
  • Conductive Materials (AREA)
  • Thermistors And Varistors (AREA)
  • Air-Conditioning For Vehicles (AREA)
  • Wick-Type Burners And Burners With Porous Materials (AREA)
  • Resistance Heating (AREA)
EP82304744A 1981-09-09 1982-09-09 Heating diesel fuel Expired EP0074281B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT82304744T ATE35745T1 (de) 1981-09-09 1982-09-09 Erhitzen von diesel-brennstoff.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US30070981A 1981-09-09 1981-09-09
US300709 1981-09-09

Publications (2)

Publication Number Publication Date
EP0074281A1 EP0074281A1 (en) 1983-03-16
EP0074281B1 true EP0074281B1 (en) 1988-07-13

Family

ID=23160253

Family Applications (1)

Application Number Title Priority Date Filing Date
EP82304744A Expired EP0074281B1 (en) 1981-09-09 1982-09-09 Heating diesel fuel

Country Status (6)

Country Link
EP (1) EP0074281B1 (cs)
JP (2) JPS5853939A (cs)
AT (1) ATE35745T1 (cs)
CA (1) CA1236246A (cs)
DE (1) DE3278775D1 (cs)
GB (1) GB2106920B (cs)

Families Citing this family (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA1236246A (en) * 1981-09-09 1988-05-03 Raychem Corporation Electrically conductive polyvinylidene fluoride compositions
US4571481A (en) * 1983-03-11 1986-02-18 Raychem Corporation Method and apparatus for electrically heating diesel fuel
US4722853A (en) * 1985-08-12 1988-02-02 Raychem Corporation Method of printing a polymer thick film ink
JPS6265401A (ja) * 1985-09-18 1987-03-24 安田　繁之 感熱電気抵抗組成物における定常発熱温度の調整方法
US4861966A (en) * 1985-10-15 1989-08-29 Raychem Corporation Method and apparatus for electrically heating diesel fuel utilizing a PTC polymer heating element
EP0242029B1 (en) 1986-02-20 1991-12-11 RAYCHEM CORPORATION (a Delaware corporation) Method and articles employing ion exchange material
JPH0799721B2 (ja) * 1986-09-13 1995-10-25 日本メクトロン株式会社 Ｐｔｃ組成物の製造法
US5174924A (en) * 1990-06-04 1992-12-29 Fujikura Ltd. Ptc conductive polymer composition containing carbon black having large particle size and high dbp absorption
FR2816625A1 (fr) * 2000-11-13 2002-05-17 Atofina Materiau composite polymerique conducteur a resistance auto-controlee par la temperature
FR2816626A1 (fr) * 2000-11-13 2002-05-17 Atofina Materiau composite polymerique conducteur a resistance auto-controlee par la temperature
JP4884770B2 (ja) 2003-02-19 2012-02-29 三井・デュポンフロロケミカル株式会社 フッ素樹脂複合体組成物
US9573438B2 (en) 2013-04-10 2017-02-21 E I Du Pont De Nemours And Company Polymer thick film positive temperature coefficient carbon composition

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0068688A2 (en) * 1981-06-15 1983-01-05 RAYCHEM CORPORATION (a California corporation) Fuel line heater feedthrough

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3503923A (en) * 1967-11-20 1970-03-31 Pennsalt Chemicals Corp Vinylidene fluoride polymer compositions having high thermal stability
JPS55111183A (en) * 1979-02-20 1980-08-27 Ngk Spark Plug Co Ltd Piezoelectric high-molecular compound material
US4237441A (en) * 1978-12-01 1980-12-02 Raychem Corporation Low resistivity PTC compositions
DE2928081C2 (de) * 1979-07-12 1982-08-19 Glyco-Metall-Werke Daelen & Loos Gmbh, 6200 Wiesbaden Verbund-Schichtwerkstoff und Verfahren zu seiner Herstellung
CA1236246A (en) * 1981-09-09 1988-05-03 Raychem Corporation Electrically conductive polyvinylidene fluoride compositions

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0068688A2 (en) * 1981-06-15 1983-01-05 RAYCHEM CORPORATION (a California corporation) Fuel line heater feedthrough

Also Published As

Publication number Publication date
GB2106920A (en) 1983-04-20
JPH0334498B2 (cs) 1991-05-22
JPS5853939A (ja) 1983-03-30
CA1236246A (en) 1988-05-03
DE3278775D1 (en) 1988-08-18
ATE35745T1 (de) 1988-07-15
JPH0395248A (ja) 1991-04-19
GB2106920B (en) 1985-06-26
EP0074281A1 (en) 1983-03-16

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