Taiyo Yuden Co., Ltd.

Tomonori Endo

Yuaki Shin

Mamoru Uchida

Yoshimasa Shimomura

Takanobu Matsumoto

Ippei Maekawa

Yuki Takei

Disc-shaped information recording medium comprising optical penetrating substrate having colored underlayer and ink receipt layer in this order on the principal surface of one side of the substrate, wherein the ink receipt layer contains inorganic fine particles, a binder, and a crosslinking agent, and wherein a pore diameter distribution of a gap of the ink receipt layer has a maximum peak in the range of 30 nm or more when the ink receipt layer is measured with a mercury porosimetry method. Since the shrinkage force functioning in the pores of the gaps of the ink receipt layer weakens, a disc-shaped information recording medium having a reduced occurrence of warp is provided.

Informaton recording medium and manufacturing method of the same

One inventive aspect relates to an optical information recording medium, in which the quality of a printed image is not impaired because the water resistance of a printed portion is improved. The optical information recording medium includes a porous film ink receiving layer as an outermost layer of a surface opposite to a recording and playback surface, wherein when the ink receiving layer is printed with an ink of each of four colors, cyan, magenta, yellow, and black, followed by drying, a running water test is performed, and L*a*b* values before and after the running water test are measured with a colorimeter, the total value of the square root of the sum of the square of difference in L*, the square of difference in a*, and the square of difference in b*, each between before and after the running water test, of each of the four colors is approximately 20 or less.

Optical information recording medium

One inventive aspect relates to an optical information recording medium which has a high gloss and ensures, even after printing, a gloss substantially equal to that before the printing, and which can increase quality of a printed image. The optical information recording medium has an ink absorbing layer made of a porous film, which is formed on an outermost layer on a surface thereof on the side opposed to a recording/reproducing surface of the optical information recording medium. The optical information recording medium has a surface gloss of the ink absorbing layer is about 25 or more in terms of 60&#xb0; specular gloss before printing and has a level after the printing which is equal to or higher than a level before the printing.

There is provided an optical information recording medium which can meet opposite requirements of enhancement in ink absorption and fixation properties of an image forming layer and suppression and prevention of solid attachment of a printed portion, which has excellent printability to obtain high image quality and an excellent holding property of the printed portion, and which little makes the solid attachment on the printed surface layer occur. At this time, a thick layer can be formed even by the use of a coating solution for the image forming layer. The optical information recording medium has the image forming layer on various layers stacked on a surface of a light transmitting substrate and optically readable signals are recorded or can be recorded therein by the use of laser beams incident on the other surface of the light transmitting substrate, wherein the image forming layer includes an ink absorbing porous layer made of a resin layer containing vapor inorganic particles. A hydrophobic portion is formed in a portion beside the porous layer on the surface of a layer adjacent to the porous layer. An anchor layer is disposed under the porous layer.

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Gunma, Japan

Tomonori Endo