| 摘要 |
PURPOSE:To obtain an ink jet recording sheet imparting a large ink dot diameter, excellent in ink absorbancy and suitable for high speed recording and multicolor recording, by using a needle calcium carbonate crystal as at least a part of the pigment of an under coat layer. CONSTITUTION:Since the uppermost layer has a void structure having an ink absorbing property, the ink liquid droplet adhered to the surface of said layer penetrates in the voids of the uppermost layer at first. Next, the ink liquid droplet reaching an under coat layer penetrates in the voids thereof but, since needle calcium carbonate is contacted in the under coat layer, the penetration speed of the ink liquid droplet of the under coat layer is slower than that of the uppermost layer in spite of the large absorbing capacity of the under coat layer. As a result, since the penetration speed of the ink liquid droplet in the lateral direction along the adjacent surface with the uppermost layer is faster than that in the vertical direction of the under coat layer, an ink dot diameter becomes large. Further, by regulating the content of needle calcium carbonate in the under coat layer, the ink absorbancy fitted to a recording apparatus and the expanse of the ink dot diameter can be controlled. |
