Printing paper

Patent metadata

Field	Value
Publication number	US-10906344-B2
Application number	US-201816603777-A
Country	US
Kind code	B2
Filing date	Mar 12, 2018
Priority date	May 2, 2017
Publication date	Feb 2, 2021
Grant date	Feb 2, 2021

Abstract

A printing paper having a base paper and an outermost coating layer is provided, and satisfies at least one of the following characteristics (I), (II) and (III): (I) when an aqueous solution having a surface tension of 20 mN/m is dropped on the side having the outermost coating layer of the printing paper, a contact angle between the droplet and the outermost coating layer is 40° or more and 65° or less; (II) for the side having the outermost coating layer of the printing paper, a transfer amount of an aqueous solution having a surface tension of 20 mN/m at a contact time of 1 second as determined by the Bristow method is 5.0 ml/m2 or more and 12.0 ml/m2 or less; and (III) on the surface of the outermost coating layer of the printing paper, a maximum peak value of specular reflection light quantity of a point image is 2,000 or more and 30,000 or less.

First claim

The invention claimed is:

1. A printing paper having a base paper, and one or more coating layer(s) arranged on at least one surface of the base paper, wherein,
in the coating layer(s), an outermost coating layer positioned on an outermost side with respect to the base paper contains at least a pigment, a binder, a lubricant, a dispersant and a cationic resin, wherein the pigment in the outermost coating layer contains kaolin and calcium carbonate, a content of the kaolin and the calcium carbonate is 80 parts by mass or more based on 100 parts by mass of the pigment in the outermost coating layer, and a mass content ratio of the kaolin to the calcium carbonate in the outermost coating layer is 1:9 to 6:4, and
the printing paper satisfies at least one of the following characteristics (I), (II) and (III):
(I) when an aqueous solution having a surface tension of 20 mN/m is dropped on the side having the outermost coating layer of the printing paper, a contact angle between the droplet and the outermost coating layer is between 40° and 65°;
(II) for the side having the outermost coating layer of the printing paper, a transfer amount of an aqueous solution having a surface tension of 20 mN/m at a contact time of 1 second as determined by a Bristow method is between 5.0 ml/m 2 and 12.0 ml/m 2 ; and
(III) on the surface of the outermost coating layer of the printing paper, a maximum peak value of specular reflection light quantity of a point image is between 2,000 and 30,000.

2. The printing paper according to claim 1 , wherein;
the printing paper satisfies characteristic (I).

3. The printing paper according to claim 1 , wherein,
the printing paper satisfies characteristic (II).

4. The printing paper according to claim 3 , wherein
for the side having the outermost coating layer of the printing paper, a transfer amount of an aqueous solution having a surface tension of 20 mN/m at a contact time of 0.4 second as determined by the Bristow method is further measured, and a value of (the transfer amount of an aqueous solution having a surface tension of 20 mN/m at a contact time of 1 second as determined by the Bristow method)—(the transfer amount of an aqueous solution having a surface tension of 20 mN/m at a contact time of 0.4 second as determined by the Bristow method) is 0.5 ml/m 2 or more and 2.5 ml/m 2 or less.

5. The printing paper according to claim 1 ,
the printing paper satisfies characteristic (III).

Assignees

• Mitsubishi Paper Mills Ltd

Inventors

• Nagoshi Masanori
• Nishi Tetsuya
• Kaneko Toru
• Takada Hideki
• Takishiro Masayuki

Classifications

• B41M5/5236

  characterised by the use of natural gums, of proteins, e.g. gelatins, or of macromolecular carbohydrates, e.g. cellulose · CPC title

• B41M5/5254

  characterised by the use of polymers obtained by reactions only involving carbon-to-carbon unsaturated bonds, e.g. vinyl polymers · CPC title

• D21H19/385

  Oxides, hydroxides or carbonates · CPC title

• B41M5/529

  characterised by the use of fluorine- or silicon-containing organic compounds · CPC title

• B41M5/5227

  characterised by organic non-macromolecular additives, e.g. UV-absorbers, plasticisers, surfactants · CPC title