Dai Nippon Insatsu Kabushiki Kaisha

Dai Nippon Printing Co., Ltd.

Hirokatsu Imamura

Shigeki Umise

Hirokazu Kaneko

Koichi Nakamura

Masafumi Hayashi

Kenichiro Suto

Kouichi Nakamura

Hiromi Watanabe

Jiro Ohnishi

Kyoichi Yamamoto

Akira Mizobuchi

Yasuo Sato

Takayasu Hirano

Nobuhiko Ikebayashi

When a temporary adhesive layer for peelably bonding a transfer-receiving material to a thermal transfer sheet comprising a substrate film and a heat-fusible ink layer disposed on one side thereof is caused to comprise a specific adhesive, an excellent composite thermal transfer material is provided. In such a composite thermal transfer sheet, the thermal transfer sheet is firmly bonded to the transfer-receiving material so as not to cause wrinkles or deviation, both of these members may easily be peeled from each other so that the ink layer is exactly transferred to the paper in a transfer region and it is not transferred thereto at all in a non-transfer region, whereby the transfer-receiving material is not contaminated. An antistatic treatment provides a composite thermal transfer sheet causing no trouble due to charging at the time of or after printing operation. When at least one end portion of a sheet-type composite thermal transfer sheet is fixed, there is provided a composite thermal transfer sheet wherein unintended peeling is prevented.

Composite thermal transfer sheet

Thermal transfer sheet

A co-winding type thermal transfer sheet is constituted by forming on one surface side of a substrate film a heat-fusible ink layer comprising a pigment and a particulate binder, and causing a tracing paper to be peelably bonded onto the heat-fusible ink layer by the medium of an adhesive layer. The thus constituted co-winding type thermal transfer sheet is capable of providing an original image which can be reproduced by use of a blueprint process so as to provide blueprint images having a high precision and a high contrast. In addition, a co-winding type thermal transfer sheet may also be constituted by forming a heat-fusible ink layer on one surface side of a substrate film and causing a transparent resin sheet to be peelably bonded onto the heat-fusible ink layer by the medium of an adhesive layer containing a cross-linking agent. The thus constituted co-winding type thermal transfer sheet is capable of providing an image excellent in wear resistance on the transparent resin sheet. The transparent resin sheet after the image formation may be used as an OHP (overhead projector) sheet without contaminating the sheet having no liquid absorbing property.

A co-winding type thermal transfer sheet is constituted by forming on one surface side of a substrate film a heat-fusible ink layer comprising a pigment and a particulate binder, and causing a tracing paper to be peelably bonded onto the heat-fusible ink layer by the medium of an adhesive layer. The thus constituted co-winding type thermal transfer sheet is capable of providing an original image which can be reproduced by use of a blueprint process so as to provide blueprint images having a high precision and a high contrast. In addition, a co-winding type thermal transfer sheet may also be constituted by forming a heat-fusible ink layer on one surface side of a substrate film and causing a transparent resin sheet to be peelably bonded onto the heat-fusible ink layer by the medium of an adhesive layer containing a cross-linking agent. The thus constituted co-winding type thermal transfer sheet is capable of providing an image excellent in wear resistance on the transparent resin sheet. The transparent resin sheet after the image formation may be used as an OHP (overhead projector) sheet. without contaminating the sheet having no liquid absorbing property.

When a temporary adhesive layer for peelable bonding a transfer-recieving material to a thermal transfer sheet comprising a substrate film and a heat-fusible ink layer disposed on one side thereof is caused to comprise a specific adhesive, an excellent composite thermal transfer material is provided. In such a composite thermal transfer sheet, the thermal transfer sheet is firmly bonded to the transfer-recieving material so as not to cause wrinkles or deviation, both of these members may easily be peeled from each other so that the ink layer is exactly transferred to the paper in a transfer region and is not transferred thereto at all in a non-transfer region, whereby the transfer-recieving material is not contaminated. Further, when at least one one end portion of a sheet-type composite thermal transfer sheet is fixed, there is provided a composite thermal transfer sheet wherein unintended peeling is prevented. Further, when an end portion of a co-winding type composite thermal transfer sheet is fixed, there is provided a composite thermal transfer wherein troubles in paperfeeding and printing is prevented. Further, when an end portion of a co-winding type composite thermal transfer sheet is preliminarily fixed to a winding tube, there is provided a composite thermal transfer sheet wherein the used thermal transfer sheet is easy to be handled and no problem occurs in secret-keeping.

A strip or roll of thermal transfer type recording sheet has a base film on one side of which a hot-melt ink layer is formed for recording on paper or other surface by thermal transfer. An end mark or marks to be detected optically for warning the user of the fact that the recording roll is being used up is/are formed adjacent one end of the strip by gravure printing with use of a light-reflective ink. The end mark or marks produced by gravure printing are of such constant thickness, and with the bounding edges so sharply defined, that they permit positive detection by an optical sensor. For the production of the end marks by gravure printing, a web of base film with the hot-melt ink layer formed on one side thereof, with a width several times greater than that of each strip of recording sheet to be manufactured, is fed through a printing unit of a gravure printing section. A set of end marks printed by the printing unit on the web in juxtaposition in its transverse direction are dried immediately, with the drying effect exerted only on the end marks. Then, while being still fed continuously, the web is slit at a slitting section into the required narrower strips of recording sheet each bearing one of the end marks. The separate strips of recording sheet are subsequently wound into rolls.

Apparatus for manufacturing strips of thermal transfer recording sheets

A thermal transfer sheet which is capable of preventing ground staining, trailing, etc., at the time of printing and has been improved in image density, resolution, etc., is provided by forming a sensitizing layer having a lower melt viscosity than an ink layer between the ink layer and a substrate film, even when such a thermal transfer sheet is used for an n-fold recording mode. Further, a thermal transfer sheet suitable for an n-fold recording mode which is capable of uniformly transferring an ink layer, is capable of preventing white dropout, ground staining, trailing, etc., at the time of printing, and has been improved in image density, resolution, etc., is provided by forming a surface layer on the surface of the ink layer, and forming the ink layer and surface layer so that the ink layer has a melt viscosity of 1000-5000 cps at 100.degree. C. and the surface layer has a melt viscosity of 2000-10000 cps at 150.degree. C.

When a temporary adhesive layer for peelably bonding a transfer-receiving material to a thermal transfer sheet comprising a substrate film and a heat-fusible ink layer disposed on one side thereof is caused to comprise a specific adhesive, an excellent composite thermal transfer material is provided. In such a composite thermal transfer sheet, the thermal transfer sheet is firmly bonded to the transfer-receiving material so as not to cause wrinkles or deviation, both of these members may easily be peeled from each other so that the ink layer is exactly transferred to the paper in a transfer region and it is not transferred thereto at all in a non-transfer region, whereby the transfer-receiving material is not contaminated. Further, when at least one end portion of a sheet-type composite thermal transfer sheet is fixed, there is provided a composite thermal transfer sheet wherein unintended peeling is prevented.

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Tokyo, Japan

Hirokatsu Imamura