US3183115A - Process for preparing bonded reconstituted mica - Google Patents

Process for preparing bonded reconstituted mica Download PDF

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Publication number
US3183115A
US3183115A US120989A US12098961A US3183115A US 3183115 A US3183115 A US 3183115A US 120989 A US120989 A US 120989A US 12098961 A US12098961 A US 12098961A US 3183115 A US3183115 A US 3183115A
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US
United States
Prior art keywords
mica
mat
solution
board
ammonium silicate
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 - Lifetime
Application number
US120989A
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English (en)
Inventor
Richard J Ketterer
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.)
General Electric Co
Original Assignee
General Electric Co
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 General Electric Co filed Critical General Electric Co
Priority to US120989A priority Critical patent/US3183115A/en
Priority to GB24919/62A priority patent/GB992815A/en
Priority to JP2701262A priority patent/JPS4022434B1/ja
Priority to CH1422165A priority patent/CH434492A/de
Priority to CH788262A priority patent/CH405446A/de
Priority to DEG35339A priority patent/DE1185975B/de
Application granted granted Critical
Publication of US3183115A publication Critical patent/US3183115A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • 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
    • H01B3/02—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of inorganic substances
    • H01B3/04—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of inorganic substances mica
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B28/00—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements
    • C04B28/24—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements containing alkyl, ammonium or metal silicates; containing silica sols
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J19/00—Details of vacuum tubes of the types covered by group H01J21/00
    • H01J19/42—Mounting, supporting, spacing, or insulating of electrodes or of electrode assemblies
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J2893/00—Discharge tubes and lamps
    • H01J2893/0001—Electrodes and electrode systems suitable for discharge tubes or lamps
    • H01J2893/0002—Construction arrangements of electrode systems
    • H01J2893/0005—Fixing of electrodes

Definitions

  • This invention relates to silica bonded materials. More particularly, it relates to reconstituted micaceous materials bonded with silica which are characterized by increased handleability, chemical inertness and absence of volatiles.
  • Reconstituted micaceous materials, mica paper or mica mat, as it is variously known, is described in various patents such as Bardet 2,549,880, April 24, 1951 and elsewhere.
  • such reconstitu'ted mica mat is made by heating mica to a temperature sufficient to produce cleavage and then comminuting .by various methods to a finely divided state which is then reconstituted in the form of a mat or sheet by well known paper making methods.
  • the mica mat so prepared consists essentially of mica in its pure state. Other methods of making such mica are Well known to those skilled in the art. However, it is so fragile and lacks tensile strength to such a degree that from a practical point of view it is difficult to fabricate structures from the material as is.
  • the mica board is useful in many electrical insulating applications but there are some uses, notably as spacers in vacuum tubes and the like, where absence of metallic ions and of organic or other gas producing'materials should as would be in ordinary impregnants is indicated.
  • the invention relates to reconstituted micaceous material which is impregnated with a solution of ammonium silicate, the material then being heated to drive off the ammonia, leaving a mica mat which is bonded together with pure silica.
  • the mica paper depending upon the mode of application, picks up from 0.25 to 3.5 times its own weight of impregnant.
  • the paper When the paper has become saturated with the ammonium silicate solution, it is dried at a low temperature varying from about C. and 100 C. to a leathery condition having approximately 1.1 to 2.0 times the origiabout 25,000 p.s.i.
  • the wet strength of the mica paper which is treated with the above ammonium silicate solution is markedly increased over that which is not so treated. Since ordinary mica mat is very fragile and hard to handle, this increase in wet strength greatly simplifies the handling to form a mica board and brush-impregnated with a 15 y percent ammonium silicate solution to the point where it had absorbed 1.7 times its own weight of the solution.
  • the board so treated was partially dried at a temperature of 55 C. for fifteen minutes to a leathery condition at which point it weighted 1.35 times the original weight of the mica paper.
  • the laid-up board was pressed at 500 p.s.i. for two hours at 93 C. and for two hours at 200 C. and then cooled under pressure.
  • Another board 30 mils thick was laid up from mica mat as above and painted with a l5'percent by weight solution of ammonium silicate.
  • the board which absorbed its own weight of the solution was dried to a leatherystate at 55 C. for ten minutes. It was then pressed at 500 p.s.i. for one hour at 200 C: and cooled while under pressure.
  • the resultant board had very desirable characteristics.
  • the bonded micaceous material described herein is also useful in electrodynamic machine applications, in insulating applications such as slot liners, slot wedges, commutator retaining rings, phase spacers, segment plates and the like.
  • the materials are useful in any application where high electrical insulating characteristics are desired, part cularly where such characteristics are mandatory at elevated, as well as, ordinary temperatures.
  • the process of bonding reconstituted mica mat which comprises impregnating said mat with a solution of S to 30 percent by weight ammonium silicate in water, heating said mat to drive off ai-nmortia and pressing at a pressure of from 25 to 2,000 p.s'.i. at a temperature of from about 75 C. to 200 C. to form a unitary structure.
  • the process of bonding reconstituted mica mat which comprises impregnating said mica with a solution of 5 to 30 percent by weight ammonium silicate in water, heating said mica to drive off ammonia and pressing under a pressure of from 25 to 2,000 psi. at a temperature of from C. to 200 C. and cooling under pressure.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Inorganic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Ceramic Engineering (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Materials Engineering (AREA)
  • Structural Engineering (AREA)
  • Organic Chemistry (AREA)
  • Inorganic Insulating Materials (AREA)
  • Insulating Bodies (AREA)
  • Paper (AREA)
US120989A 1961-06-30 1961-06-30 Process for preparing bonded reconstituted mica Expired - Lifetime US3183115A (en)

Priority Applications (6)

Application Number Priority Date Filing Date Title
US120989A US3183115A (en) 1961-06-30 1961-06-30 Process for preparing bonded reconstituted mica
GB24919/62A GB992815A (en) 1961-06-30 1962-06-28 Production of reconstituted mica articles
JP2701262A JPS4022434B1 (de) 1961-06-30 1962-06-28
CH1422165A CH434492A (de) 1961-06-30 1962-06-29 Elektronenröhre
CH788262A CH405446A (de) 1961-06-30 1962-06-29 Verfahren zur Herstellung verfestigter, silikatgebundener Glimmerplatten oder -folien
DEG35339A DE1185975B (de) 1961-06-30 1962-06-29 Verfahren zur Herstellung eines mit Siliziumdioxyd gebundenen Glimmerblattes

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US120989A US3183115A (en) 1961-06-30 1961-06-30 Process for preparing bonded reconstituted mica

Publications (1)

Publication Number Publication Date
US3183115A true US3183115A (en) 1965-05-11

Family

ID=22393744

Family Applications (1)

Application Number Title Priority Date Filing Date
US120989A Expired - Lifetime US3183115A (en) 1961-06-30 1961-06-30 Process for preparing bonded reconstituted mica

Country Status (5)

Country Link
US (1) US3183115A (de)
JP (1) JPS4022434B1 (de)
CH (2) CH434492A (de)
DE (1) DE1185975B (de)
GB (1) GB992815A (de)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3804704A (en) * 1971-12-27 1974-04-16 Gen Electric Mica paper laminates
EP1464633A1 (de) * 2003-04-02 2004-10-06 H.C. Starck GmbH Verfahren zur Herstellung slikatischer Formkörper

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2791262A (en) * 1952-08-29 1957-05-07 Mica Insulator Company Sized mica paper and process of preparing the same
US2917426A (en) * 1958-09-26 1959-12-15 Du Pont Felted products and processes containing fibrous boehmite
US2953466A (en) * 1956-08-09 1960-09-20 North American Aviation Inc Silicon-mica composition

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH277575A (fr) * 1947-05-12 1951-09-15 Samica Societe Des Applic Du M Procédé pour la fabrication d'articles, à partir de mica.

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2791262A (en) * 1952-08-29 1957-05-07 Mica Insulator Company Sized mica paper and process of preparing the same
US2953466A (en) * 1956-08-09 1960-09-20 North American Aviation Inc Silicon-mica composition
US2917426A (en) * 1958-09-26 1959-12-15 Du Pont Felted products and processes containing fibrous boehmite

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3804704A (en) * 1971-12-27 1974-04-16 Gen Electric Mica paper laminates
EP1464633A1 (de) * 2003-04-02 2004-10-06 H.C. Starck GmbH Verfahren zur Herstellung slikatischer Formkörper
JP2004307336A (ja) * 2003-04-02 2004-11-04 Hc Starck Gmbh 成形体の製造方法、成形体、その使用及び遮断材料及び支持パネル

Also Published As

Publication number Publication date
DE1185975B (de) 1965-01-21
CH405446A (de) 1966-01-15
CH434492A (de) 1967-04-30
GB992815A (en) 1965-05-19
JPS4022434B1 (de) 1965-10-05

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