| 摘要 |
PURPOSE:To improve the photographic characteristics and the physical strength such as the surface strength, etc. of the subject paper by incorporating at least one of a compd. selected from a group comprising a water soluble aluminium salt, a rosin sizing agent, a polyacryl amide and a polyamide epoxy resin in the paper, and specifying the pH of the paper at the time of extracting the paper with a cold water to a prescribed value. CONSTITUTION:At least one of the compd. selected from the group comprising the water soluble aluminium salt, the rosin sizing agent, the polyacryl amide and the polyamide epoxy resin is incorporated in the paper, and the pH of the paper at the time of extracting the paper with the cold water is specified to 3.5-6.0. Namely, the water soluble aluminium salt is useful to increase the effects of a sizing agent and a paper strength reinforcing agent. One or more kinds of the rosin sizing agent, the polyacryl amide and the polyamide epoxy resin are useful to improve the surface strength and the like of the paper by specifying the pH value of the paper to a range of 3.5-6.0. |
