US2795522A - Processes of coating - Google Patents

Processes of coating Download PDF

Info

Publication number
US2795522A
US2795522A US375127A US37512753A US2795522A US 2795522 A US2795522 A US 2795522A US 375127 A US375127 A US 375127A US 37512753 A US37512753 A US 37512753A US 2795522 A US2795522 A US 2795522A
Authority
US
United States
Prior art keywords
coating
water
pressure
linear speed
mercury
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
US375127A
Other languages
English (en)
Inventor
Walter T Johns
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.)
EIDP Inc
Original Assignee
EI Du Pont de Nemours and 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
Priority to BE530377D priority Critical patent/BE530377A/xx
Application filed by EI Du Pont de Nemours and Co filed Critical EI Du Pont de Nemours and Co
Priority to US375127A priority patent/US2795522A/en
Priority to GB16292/54A priority patent/GB755151A/en
Priority to FR1111064D priority patent/FR1111064A/fr
Priority to DEP12455A priority patent/DE961783C/de
Application granted granted Critical
Publication of US2795522A publication Critical patent/US2795522A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D1/00—Processes for applying liquids or other fluent materials
    • B05D1/26—Processes for applying liquids or other fluent materials performed by applying the liquid or other fluent material from an outlet device in contact with, or almost in contact with, the surface
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
    • D21H23/00—Processes or apparatus for adding material to the pulp or to the paper
    • D21H23/02—Processes or apparatus for adding material to the pulp or to the paper characterised by the manner in which substances are added
    • D21H23/22—Addition to the formed paper
    • D21H23/46—Pouring or allowing the fluid to flow in a continuous stream on to the surface, the entire stream being carried away by the paper
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
    • D21H5/00—Special paper or cardboard not otherwise provided for
    • D21H5/0005—Processes or apparatus specially adapted for applying liquids or other fluent materials to finished paper or board, e.g. impregnating, coating
    • D21H5/0042—Processes or apparatus specially adapted for applying liquids or other fluent materials to finished paper or board, e.g. impregnating, coating by pouring or allowing to flow in a continuous stream onto the surface, the entire stream being carried away by the paper
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03C—PHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR, STEREO-PHOTOGRAPHIC PROCESSES; AUXILIARY PROCESSES IN PHOTOGRAPHY
    • G03C1/00—Photosensitive materials
    • G03C1/74—Applying photosensitive compositions to the base; Drying processes therefor
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
    • D21H23/00—Processes or apparatus for adding material to the pulp or to the paper
    • D21H23/02—Processes or apparatus for adding material to the pulp or to the paper characterised by the manner in which substances are added
    • D21H23/22—Addition to the formed paper
    • D21H23/52—Addition to the formed paper by contacting paper with a device carrying the material
    • D21H23/64—Addition to the formed paper by contacting paper with a device carrying the material the material being non-fluent at the moment of transfer, e.g. in form of preformed, at least partially hardened coating

Definitions

  • This invention pertains to processes of coating viscous aqueous solutions. More particularly, it pertains to .a process of coating viscous aqueous solutions as layers in photographic films and papers. Still more particularly it pertains to a process of coating viscous waterpermeable colloid silver halide dispersions onto continuous webs.
  • An object of this invention is to provide a process of coating, viscous aqueous solutions onto continuous webs at rates of speeds much faster than 120 feet per minute.
  • Another object is to provide such a method wherein the coatings are of uniform thickness and free from entrapped bubbles between the coating and the web.
  • a further object is to provide such a method wherein extremely thin coatings can be made.
  • a still further object is to provide a method of coating water-permeable colloid dispersions and especially colloid silver halide dispersions onto continuous film or papers at high rates of speed.
  • Yet another object is to provide such a method which can be carried out in a relatively simple apparatus. Still other objects will be apparent from the following description of the invention.
  • the above objects are obtained in accordance with the present invention which, in its broadest aspects, comprises extruding an aqueous solution of high viscosity through a narrow orifice onto a moving web traveling at a higher linear speed than the fluid being extruded, in the substantial absence of non-condensable gases, but in the presence of a condensable vapor of an inert, water-v soluble liquid having a boiling point at atmospheric pressure not greater than about 212 F. at an absolute pressure from 20 to 190 mm. of mercury and at a temperature from 75 F. to 150 F.
  • a viscous aqueous dispersion of light-sensitive silver halides in a waterpermeable, natural or synthetic colloid is extruded in the form of a thin sheet onto a continuous flexible web, e. g., a thin film base or paper that is traveling at a linear speed of at least 150 feet per minute and from 1 to 200 times faster than the rate of extrusion of said dispersion, while adding to the coating zone the condensable vapor of a photographically-inert, water-soluble liquid having a boiling point at atmospheric pressure not greater than about 212 F., at an absolute pressure from 20 to 190 Patent 0 M mm. of mercury, the partial pressure of the non-condensable gases in said zone being not more than 5% of the 2,795,522 Patented June 11, 1957 total pressure, and maintaining said zone at a temperature from 75 F. to 150 F.
  • a continuous flexible web e. g., a thin film base or paper that is traveling at a linear speed of at least 150 feet per minute and
  • the total pressure in the coating zone should be sufficient to prevent the water-soluble solvents (including Water) in the aqueous solution being coated from boiling at the coating temperature (e. g., 75 F. to 150 F.).
  • the partial pressure of the non-condensable gases, mainly oxygen and nitrogen, being maintained at less than 5% of the total pressure means that the vapors remaining in the coating zone are substantially all condensable. complished in various ways, e. g., by first reducing the pressure in the system to below the operating pressure, for instance, 2 to 3 mm. of mercury and adding the condensable vapor of the water-soluble liquid to the coating zone to raise the total pressure to 20 to 190 mm. of mercury, or by purging the zone with condensable vapors at a higher pressure.
  • Suitable condensable vapors include the vapors of such inert, water-soluble liquids as water, methyl alcohol, ethyl alcohol, and acetone. These condensable vapors are introduced into the system at a rate in excess of the rate of evaporation or removal of water and water-soluble solvents from the coated water-permeable colloid layer carried by the film.
  • the minimum pressure of condensable vapors in the reduced pressure coating zone is equal to or slightly greater than the vapor pressure corresponding to the boiling point of the Water and/or solvents in the coated layer at the reduced pressure.
  • the water or solvents in the coated layer are removed, to the desired extent, at a later stage, for instance, by a drying operation.
  • the invention is useful in the coating of aqueous silver halide dispersions in the various types of natural and synthetic water-permeable colloids which have been used as binding agents for the silver halide grains, including gelatin, albumin, agar-agar, water-permeable polyamides, polyvinyl alcohol, partially hydrolyzed polyvinyl esters,
  • hydrophilic polyvinyl acetals including those containing color-former n'ucleij and other types of viscous aqueous This can be ac-- solutions, particularly those containing colloids. It is particularly useful in the coating of gelatinosilver halide emulsions.
  • Example I At the beginning of a coating operation a coating zone is reduced to a pressure of about 2 to mm. of mercury to remove substantially all non-condensable gases (i. e., air), water vapor is then added raising the pressure to 50 to 60 mm. of mercury, while continuing the source of vacuum.
  • substantially all non-condensable gases i. e., air
  • a gelatino silver bromide emulsion containing 50% by Weight of solids (including silver halides) and having a viscosity of about 10,000centipoises, is then extruded through a hopper provided at' its lower end with lipsv spaced approximately 0.005 inch apart,'at a rate of about 80 feet per minute'onto a cellulose acetate film base having a thickness of approximately 0.003 inch and bearing a thin gelatin sub-coating on its upper surface, which is moving through the coating zone at a rate of approximately 400 feet per minute.
  • the coating zone is maintained at a reduced pressure of about 50 to 60 mm. of mercury and a temperature of about 100 to 107 F, while water vapor is added at a rate.
  • gelatin silver halide coating as it passes from the reduced pressure zone, is free from entrapped bubbles, waves and streaks, is uniform in character and sufiiciently firm so that it can be further dried and cured at ordinary or raised temperatures, and the coated film has satisfactory photographic properties.
  • Example II A continuous sheet of paper bearing a baryta coating is passed into a coating chamber which is evacuated to a reduced pressure of about 6 mm. of mercury and maintained at a temperature of about 100 F. to 107 F. Water vapor is passed into the chamber while substantially all of the air is removed from the chamber and the pressure raised to'about 60 mm. of mercury.
  • An aqueous gelatino silver bromide photographic emulsion having a solids content of about 40% and a viscosity of 7,000 centipoises is coated in the absence of actinic light onto the baryta surface of the paper through a narrow slot orifice, the lips ofwhich are spaced about 0.01 inch apart, extruding at a rate of 30 feet per minute, said paper web being moved at a rate of 300 feet: per minute, while continuously adding water vapor and maintaining the pressure at about 50 mm. of mercury'and the temperature at about 100 F.
  • the photographic paper sheet as it passes from the reduced pressure coating zone, has satisfactory photographic properties, is smooth, free from entrapped bubbles and at normal pressure is sufficiently firm so that it can be further dried at normal or elevated temperature then passed to a wiirdup stationor slit and cut into small sheets.
  • Example III A continuous length of cellulose acetate film base supporting a gelatin substratum is fed into a coating chamber. The pressure is reduced to about 50 mm. Hg absolute and the temperature maintained at about 100 F. Water vapor is admitted to the chamber while continuing evacuation to maintain a constant pressure and purge the chamber of non-condensable gases.
  • aqueous gelatin solution of about 40% total solids, containing a water-soluble anti-halation dye and having a viscosity of 30,000 centipoises is then extruded through a hopper having at the bottom a narrow slot orifice wherein the lips are spaced about 0.020 inch apart, at a rate of approximately 40 feet per minute, onto thefilm base and gelatin sub moving at a rate of- 400 feet per EDescribed in Example I of GasparU. S. Patent. 2,214,782.
  • Various types of coating apparatus may be used in carrying out the process.
  • the essential point is to surround the coating zone with a suitable air-tight chamber provided with means for removing air and vapor from the chamber and with means for introducing the readily condensable vapor of a photographically-inert, watersolubleliquid.
  • a suitable apparatus is shown schematically in the accompanying.
  • 1 is a chamber into which a web of paper or filmpasses over a guide roller 2 and thence past pinch rolls 3 which press it against a revoluble sealing drum 4 under guide rollers 5 and 6, then upwardly and over a reller 7 which constitutes the point of coating, thence, downwardly under guide rollers 8 and 9, then upwardly through a constricted passage between .the sealing drum 4 and the curved wall 10 of the chamber 1 and then to a drying section and a windup reel (not shown).
  • the chamber is provided with openings 11 which areconnected by means of a suitable pipe 12 to .a vacuumpump or aspirator (not shown).
  • a pipe 13 also passes through the wall of the chamber and is provided with a suitable nozzle 14 for introducing a eon-densable vapor of a liquid, e. g, water into the chamber.
  • a pipe 15 communicates with a coating bar 16 which is provided with a longitudinal chamber 17 and a narrow slot orificej18 is connected with a suitable metered source of a viscous aqueous dispersion of silver halides in gelatin. .
  • the temperature of the chamber can be raised by means of heating elements 19 or a Water jacket provided with suitable sources of power.
  • the wall of chamber 1 opposite the point of coating is provided with a window'20 so that the coating operation can be observed.
  • the chamber 1 is connected with a vacuum pump and the pressure in the chamber is reduced to about2 to 3 mm. of Hg absolute. Water vapor is then introduced through pipe 13 raising the pressure to about 60 and the web to be coated is moved past the coating bar 16 while the coating material is extruded onto the Web which moves at a speed greater than the speed of extrusion so that the extruded 'film is drawn down. The vacuum is maintained during the coating operation and water vapor is continuously passed into the chamber through the pipe 13.
  • the invention is, of course, not limited to the coating of'filfu and paper with aqueous gelatin silver halide emulsionsbut is useful in coating aqueous silver halide dispe'rs'ions in other water-permeable colloids as described above.
  • it can be used in the coating of aqueous ethanol solutions of polyvinyl acetal color formers of the type described in Jennings et al. U. S. Patent 2,397,864 and Blanchard U. S. Patent 2,5 5 1,091.
  • the invention is useful in preparing multilayer photographic film elements including multicolor films both positive and negative, printing papers, double-coated X-ray films, motion picture films, portrait films, and papers, etc. It is not only useful in coating the lightsensitive silver halide colloid layers but can be used in coating light-filter layers, and anti-halation layers containing dyes and pigments which absorb the desired wavelengths of light, as well as antiabrasion layers and sublayers from aqueous solutions, including aqueous ethanol solutions. 'In these layers gelatin or the other colloids described above may constitute the film-forming binding agent.
  • the coating solutions may have a solids content of 25% to 60%.
  • An advantage of the'invention is that it provides a process ofcoating aqueous colloid layers at high rates ofspe'ed. It is particularly useful for viscosities of 30,000 to 60,000 centipoises. The process is simple to operate and: operates successfully'ona continuous basis. Another advantage is .thatthe process enables one to use silver halide emulsions of high solids content with a resultant marked decrease in drying time. Yet another advantage is that the process admits of more uniform weight control of the silver halide coatings independent of emulsion viscosity, by positive metering of the emulsion through the coating orifice.
  • a further advantage is that the process eliminates the need for chilling the aqueous gelatin silver halide emulsion coating in order to set it for further drying treatment.
  • the manifold increase in coating speed makes the process more economical than prior art processes and produces coatings of satisfactory quality.
  • a process of coating antihalation layers which comprises extruding a viscous aqueous solution containing a water-permeable colloid and an antihalation dye and .having a viscosity of 2,000 to 100,000 centipoises in the form of a sheet onto the surface of a thin flexible film base which is moving at a linear speed of at least feet per minute and 1 to 200 times faster than the linear speed of extrusion of said solution, in the substantial absence of air, in the presence of added water vapor while maintaining a pressure from 20 mm. to mm. of mercury and a temperature of 75 F. to 150 F.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Application Of Or Painting With Fluid Materials (AREA)
  • Laminated Bodies (AREA)
US375127A 1953-08-19 1953-08-19 Processes of coating Expired - Lifetime US2795522A (en)

Priority Applications (5)

Application Number Priority Date Filing Date Title
BE530377D BE530377A (de) 1953-08-19
US375127A US2795522A (en) 1953-08-19 1953-08-19 Processes of coating
GB16292/54A GB755151A (en) 1953-08-19 1954-06-02 Processes of coating
FR1111064D FR1111064A (fr) 1953-08-19 1954-07-23 Procédé d'enduction
DEP12455A DE961783C (de) 1953-08-19 1954-08-04 Verfahren zum kontinuierlichen Beschichten einer Traegerbahn mit einer viskosen wasserhaltigen Masse

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US375127A US2795522A (en) 1953-08-19 1953-08-19 Processes of coating

Publications (1)

Publication Number Publication Date
US2795522A true US2795522A (en) 1957-06-11

Family

ID=23479610

Family Applications (1)

Application Number Title Priority Date Filing Date
US375127A Expired - Lifetime US2795522A (en) 1953-08-19 1953-08-19 Processes of coating

Country Status (5)

Country Link
US (1) US2795522A (de)
BE (1) BE530377A (de)
DE (1) DE961783C (de)
FR (1) FR1111064A (de)
GB (1) GB755151A (de)

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2952569A (en) * 1958-01-28 1960-09-13 Nat Steel Corp Method and apparatus forming an ice seal in vapor deposition
US2965067A (en) * 1957-10-24 1960-12-20 Nat Res Corp Vacuum coating apparatus
US2971862A (en) * 1957-04-26 1961-02-14 Nat Res Corp Vapor deposition method and apparatus
US2972330A (en) * 1956-02-15 1961-02-21 Nat Steel Corp Vacuum seal for coating apparatus
US3043728A (en) * 1958-03-17 1962-07-10 Nat Res Corp Apparatus and process for metallic vapor coating
US3082144A (en) * 1957-11-08 1963-03-19 Du Pont Extrusion coating under reduced pressure
US3085617A (en) * 1957-01-14 1963-04-16 Sorg Adam Apparatus for forming plastic-coated filter paper webs for infusion packages
US3161560A (en) * 1961-01-04 1964-12-15 Int Paper Co Extrusion coated paper and method of making the same
US3260603A (en) * 1962-11-23 1966-07-12 Minnesota Mining & Mfg Rough surfaced copy-sheet intermediate
US3640752A (en) * 1966-05-02 1972-02-08 Fuji Photo Film Co Ltd Coating method
FR2313138A1 (fr) * 1975-06-06 1976-12-31 Eastman Kodak Co Procede ameliore de couchage d'une composition liquide sur un support

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1164174A (en) * 1914-03-02 1915-12-14 Joseph P Devine Apparatus for coating fabrics.
GB367386A (en) * 1929-11-12 1932-02-12 Luigi Cristiani Improvements in and relating to the production of photographic images
GB448863A (en) * 1934-12-10 1936-06-10 Naamlooze Vennootschap Nl Lab A process for multi-color photography
US2175125A (en) * 1937-06-15 1939-10-03 Reynolds Res Corp Method for forming films and film coatings
US2681294A (en) * 1951-08-23 1954-06-15 Eastman Kodak Co Method of coating strip material

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1164174A (en) * 1914-03-02 1915-12-14 Joseph P Devine Apparatus for coating fabrics.
GB367386A (en) * 1929-11-12 1932-02-12 Luigi Cristiani Improvements in and relating to the production of photographic images
GB448863A (en) * 1934-12-10 1936-06-10 Naamlooze Vennootschap Nl Lab A process for multi-color photography
US2175125A (en) * 1937-06-15 1939-10-03 Reynolds Res Corp Method for forming films and film coatings
US2681294A (en) * 1951-08-23 1954-06-15 Eastman Kodak Co Method of coating strip material

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2972330A (en) * 1956-02-15 1961-02-21 Nat Steel Corp Vacuum seal for coating apparatus
US3085617A (en) * 1957-01-14 1963-04-16 Sorg Adam Apparatus for forming plastic-coated filter paper webs for infusion packages
US2971862A (en) * 1957-04-26 1961-02-14 Nat Res Corp Vapor deposition method and apparatus
US2965067A (en) * 1957-10-24 1960-12-20 Nat Res Corp Vacuum coating apparatus
US3082144A (en) * 1957-11-08 1963-03-19 Du Pont Extrusion coating under reduced pressure
US2952569A (en) * 1958-01-28 1960-09-13 Nat Steel Corp Method and apparatus forming an ice seal in vapor deposition
US3043728A (en) * 1958-03-17 1962-07-10 Nat Res Corp Apparatus and process for metallic vapor coating
US3161560A (en) * 1961-01-04 1964-12-15 Int Paper Co Extrusion coated paper and method of making the same
US3260603A (en) * 1962-11-23 1966-07-12 Minnesota Mining & Mfg Rough surfaced copy-sheet intermediate
US3640752A (en) * 1966-05-02 1972-02-08 Fuji Photo Film Co Ltd Coating method
FR2313138A1 (fr) * 1975-06-06 1976-12-31 Eastman Kodak Co Procede ameliore de couchage d'une composition liquide sur un support
US4051278A (en) * 1975-06-06 1977-09-27 Eastman Kodak Company Method for reducing mottle in coating a support with a liquid coating composition

Also Published As

Publication number Publication date
FR1111064A (fr) 1956-02-22
DE961783C (de) 1957-04-11
GB755151A (en) 1956-08-15
BE530377A (de)

Similar Documents

Publication Publication Date Title
US2681294A (en) Method of coating strip material
US3206323A (en) Coating high viscosity liquids
US2795522A (en) Processes of coating
US3749053A (en) Coating apparatus
US2815307A (en) Processes for coating and drying photographic layers
GB834527A (en) Improvements in or relating to web coating apparatus
WO1982003450A1 (en) Method and apparatus for drying coated sheet material
US3082144A (en) Extrusion coating under reduced pressure
US2175125A (en) Method for forming films and film coatings
US3533833A (en) Coating process
US3916043A (en) Method of coating a spliced web
JPS635151B2 (de)
US4837045A (en) Coating method
GB855164A (en) Improvements in or relating to web coating
US3573965A (en) Multilayer coating method
US2899339A (en) Foating to a moving web
US2314453A (en) Coating and filming machine and apparatus
US2911320A (en) Production of moistureproof sheet wrapping materials
US4238533A (en) Coating process and apparatus
US3676189A (en) Method of coating a polyolefin or polyolefin-coated paper sheet material
US3638604A (en) Apparatus for coating strip-form substrates
GB1276381A (en) Coating method and apparatus
US2878521A (en) Method of manufacturing sheeting material
US3473955A (en) Coating process
JPS5837866B2 (ja) 塗布方法及び装置