US 12,168,731 B2
Marking ink composition for writing board
Tatsuya Mizoguchi, Shinagawa-ku (JP)
Assigned to MITSUBISHI PENCIL COMPANY, LIMITED, Tokyo (JP)
Filed by MITSUBISHI PENCIL COMPANY, LIMITED, Tokyo (JP)
Filed on Dec. 9, 2020, as Appl. No. 17/115,977.
Claims priority of application No. 2019-223951 (JP), filed on Dec. 11, 2019.
Prior Publication US 2021/0179872 A1, Jun. 17, 2021
Int. Cl. C09K 3/22 (2006.01); C08K 3/08 (2006.01); C08K 3/22 (2006.01); C08L 25/14 (2006.01); C08L 29/04 (2006.01); C09D 11/17 (2014.01)
CPC C09D 11/17 (2013.01) [C08K 3/08 (2013.01); C08K 3/22 (2013.01); C08L 25/14 (2013.01); C08L 29/04 (2013.01); C08K 2003/0812 (2013.01); C08K 2003/2237 (2013.01)] 20 Claims
 
1. A marking ink composition suitable for a writing board, the composition comprising:
a pigment;
a pigment dispersant resin;
a masking agent;
a modified polyvinylalcohol or a polyvinylalcohol having a degree of saponification in a range of from 40 to 84% by molar ratio; and
an erasing auxiliary,
wherein the erasing auxiliary is selected from the group consisting of a monosaccharide, a disaccharide, an oligosaccharide, a reducing sugar, a non-reducing sugar, a sugar alcohol, a reduced starch, a betaine derivative, and a long-chain fatty acid ester.