Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41N—PRINTING PLATES OR FOILS; MATERIALS FOR SURFACES USED IN PRINTING MACHINES FOR PRINTING, INKING, DAMPING, OR THE LIKE; PREPARING SUCH SURFACES FOR USE AND CONSERVING THEM
  • B41N1/00—Printing plates or foils; Materials therefor
  • B41N1/24—Stencils; Stencil materials; Carriers therefor
  • B41N1/245—Stencils; Stencil materials; Carriers therefor characterised by the thermo-perforable polymeric film heat absorbing means or release coating therefor
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/249921—Web or sheet containing structurally defined element or component
  • Y10T428/249953—Composite having voids in a component [e.g., porous, cellular, etc.]
  • Y10T428/249962—Void-containing component has a continuous matrix of fibers only [e.g., porous paper, etc.]
  • Y10T428/249964—Fibers of defined composition
  • Y10T428/249965—Cellulosic
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/249921—Web or sheet containing structurally defined element or component
  • Y10T428/249953—Composite having voids in a component [e.g., porous, cellular, etc.]
  • Y10T428/249987—With nonvoid component of specified composition
  • Y10T428/249991—Synthetic resin or natural rubbers
  • Y10T428/249992—Linear or thermoplastic

Definitions

• a heat-sensitive stencil paper for use in mimeographic printing comprising a resinous film consisting of a vinylidene chloride-vinyl chloride copolymer which has a biaxial heat shrinking coeflicient in the range of the order of 2-8% at 100 C. for 1 minute, said resinous film being lined with a porous thin sheet of paper, said stencil paper being so adapted that an image consisting of perforations is formed in said film by applying infrared light thereto.
• the present invention is concerned with a heat-sensitive stencil paper for use in mimeographic printing, and more particularly, it relates to a heat-sensitive stencil paper which comprises a resinous film consisting of a vinylidene chloride-vinyl chloride copolymer which has a biaxial heat shrinking coefiicient in the range of the order of 28% at 100 C. for 1 minute and a porous thin sheet of paper, said resinous film being adapted so that an image consisting of perforations is formed in said film by applying infrared light thereto.
• Heat-sensitive stencil papers which are of the type that a thin sheet of paper is adhesively bonded to a thermoplastic resinous film are known.
• a heat-sensitive stencil paper of this type is used in such a way that the stencil paper is exposed, through an image-carrying original laid thereon, to infrared light at the side of said thin sheet of paper, in which case the portions of the film corresponding to the image region in the original are subjected to the heat which has been accumulated, by absorption, in said image region of the original and, as a result, said portions of the film are melted in such a way that they are severed substantially in the middle part throughout the widths of said molten portions and that the regions of the molten resinous film located on both sides of the severance draw up and displace their positions in the directions away from their severad edges, resulting in that the portions of said thin sheet of paper lying beneath such portions of the film are now exposed through the opening formed between the severed edges of the film.
• thermoplastic resins which have both a narrow range of melting point and an intensive heat-shrinkability.
• vinylidene chloride-vinyl chloride copolymers for example, those disclosed in the US. Pat. No. 3,267,847 which have a very narrow range of melting point are recommended.
• the object of the present invention to provide a heat-sensitive stencil paper which is capable of forming a printing image consisting of an aggregation of perforations and being superior in resolution, by the employment of such a resinous film that consists of a vinylidene chloride-vinyl chloride copolymer and that has been made to have an appropriate heat-shrinkability by subjecting said film to biaxial drawing.
• resinous film having an extremely small heat-shrinking coeflicient there was prepared a vinylidene chloride film having a heat-shrinking coefiicient of about zero at 100 C. for 1 minute, by the use of a commercial vinylidene chloride film (trade name: Krewrap, a product of Kureha Chemical Industry Co. of Japan) which, in itself, had relatively large heat-shrinking coetficient.
• This film was dissolved in tetrahydrofuran, and this solution was poured onto a flat plate so as to flow thereover, and then dried.
• vinylidene chloride-vinyl chloride copolymer films which can produce satisfactory results when used for practical purposes must have a heat-shrinking coefiicient 1n the range of 28% biaxially.
• Vinylidene chloride-vinyl chloride copolymers which satisfy this condition desirably have a Vinylidene chloride/vinyl chloride polymerizing proportion in the range of 7030/955.
• the total amount of the additives used, such as a plasticizer desirably is 20% or smaller relative to the aforesaid copolymer employed. Description will hereunder be directed to the method of manufacturing films of this type.
• porous thin sheet of paper which can be applied to the present invention.
• any of the following papers i.e. papers made of natural fibers such as mitsumata fibers and manila hemp fibers; synthetic fibers such as rayon fibers, acrylic fibers and nylon fibers; and mixtures thereof.
• This film is then passed through a set of rolls, and the resulting collapsed annular film is cut at both side edges to produce two sheets of film which are wound around two separate cores, respectively.
• the films have been drawn biaxially by the inflation by air.
• these films have a heat-shrinking coefficient of -20% in general. Therefore, in order that these films are used in the present invention, they may not or may be cut into an appropriate size, and they are either treated with a solvent or given a heat treatment so that they will have a reduced heat-shrinking coefficient in the range of 28%.
• thermoplastic resin there are the extrusion process which utilizes a T- die; the casting process; the calendering process; the skiving process; the emulsion process; and some others. Many of the films obtained from these known processes, however, either lack heat shrinkability or they are oriented in only one direction. Therefore, these films require to be given some sort of drawing process so that they will have a heat shrinking coefiicient of the order of 28% biaxially in order that the films may be made applicable to the present invention.
• films formed by these known film-forming processes those obtained by the casting process and those by the extrusion process utilizing a T- die, of all other processes, are adaptable to the present invention.
• the employment of the tenter process is appropriate.
• the films ob- 4 tained by the inflation process can be applied to the present invention provided that the expansion of the film by air inflation is low in degree.
• Example 1 To a synthetic resin powder made of a copolymer consisting of of vinylidene chloride and 15% of vinyl chloride were added 4% by weight of 3-(2-xenyloxy)-1,2- epoxypropane and 4% by weight of 4-tertiary butylphenyl salicylate, and thus, a composition was prepared. This composition was then subjected to molding by the air inflation technique to produce a film having a transverse heat-shrinking coefficient (at C., for 1 minute) of 12% and a longitudinal heat-shrinking coefficient of 20% and a thickness of 810/.L.
• a transverse heat-shrinking coefficient at C., for 1 minute
• thisfilm was immersed for 10 seconds in acetone which was held at about 20 C., and then dried in the air at 20 C.
• the resulting film showed a transverse heat shrinkability of 4% and a longitudinal heat shrinkability of 7%.
• This film was then bonded to a porous thin sheet of paper having a thickness of 40 As a result, a satisfactory heat-sensitive stencil paper was obtained.
• Example 2 A similar experiment was conducted by the use of methylethylketone (MEK) instead of the aforesaid acetone, but the result was substantially the same as that obtained in the preceding example.
• MEK methylethylketone
• Example 3 A 10% tetrahydrofuran solution of a resin made of a copolymer consisting of 88% by weight of Vinylidene chloride and 12% by weight of vinyl chloride was prepared. A small amount (about 3% by weight) of di-(2- phenylethyl) ether and 2-hydroxy-5-chlorobenzophenone was added to said solution.
• the aforesaid mixed solution was subjected to casting process at the film-forming speed of 10 m/min. and thus, a film of 20;/. in thickness was obtained. While heating this film, the latter was drawn longitudinally to a length twice the original length.
• Example 1 Thereafter, the resulting film was led to a tenter wherein it was drawn transversely twice the original length. While holding the bilateral edges of the film in the rearward section of the tenter, the film was heat set. As a result, the film was converted to homogeneous one which had a heat shrinking coefiicient of about 3% at 100 C. for 1 minute biaxially.
• a perforated printing sheet was prepared with this film in a manner similar to that described in Example 1, and the printing sheet was tested. The result was from comparable to superior to the result obtained in Example 1.
• references Cited 1 In a heat-sensitive stencil paper comprising a synthetic resin film bonded to a porous thin fibrous sheet, the UNITED STATES PATENTS 2,699,113 1/1955 Hoover 101128.4
• said film being vinyliden'e chloride-'vinyl chloride copolymer, the improvement in which 5 3,267,847 8/1966 Hayama et a1 101 128-2 DAVID KLEIN, Primary Examiner the mol ratio of vinylidene chloride/vinyl chloride in said film is in the range of 70/ 30-95/ 5 and the film contains at least 80% by weight of said vinylidene chloride-vinyl U S C1 X R chloride copolymer, said film having a biaxial heat-shrinking coetficient in the range of 2% to 8% measured at 10 100 C. for one minute.

Landscapes

• Printing Plates And Materials Therefor (AREA)
• Laminated Bodies (AREA)
• Shaping By String And By Release Of Stress In Plastics And The Like (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=13247764

Family Applications (1)

Country Status (4)

Cited By (3)

Families Citing this family (2)

• 1968
  • 1968-09-18 US US760718A patent/US3620160A/en not_active Expired - Lifetime
  • 1968-10-02 DK DK475668AA patent/DK122798B/da unknown
  • 1968-10-03 FR FR1585742D patent/FR1585742A/fr not_active Expired
  • 1968-10-04 GB GB1250813D patent/GB1250813A/en not_active Expired

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