オオサワ　シゲヒト   Oosawa Shigehito   大澤　重仁    所属   医学研究科 医学研究科 (医学部医学科をご参照ください)    職種   非常勤講師
論文種別	原著
言語種別	英語
査読の有無	査読あり
表題	Tuning Pre-Solution of an Amphiphilic Polymeric Dispersant with Low Acid-Value toward Colored-Ink Preparation
掲載誌名	正式名：Applied Sciences-Basel 略　 称：Appl. Sci. ISSNコード：20763417
掲載区分	国外
巻・号・頁	13(3),pp.1834
総ページ数	14
著者・共著者	Masahiko Asada, Hisakazu Tanaka, Yukie Suwa, Sachiko Irifune, Shigehito Osawa and Hidenori Otsuka
発行年月	2023/01/31
概要	Recently, a variety of amphiphilic block copolymers for water-based color inks as pigment dispersants have been developed. Although such dispersants require both high adsorption of pigments and dispersion-stability in water, the most crucial issue is the difficulty in controlling the affinity balance of the polymeric dispersants between the pigments and aqueous media. Therefore, it is important to increase the solubility of the hydrophobic polymers with low acid-value for ink design. Amphiphilic block copolymers containing styrene-based blocks as hydrophobic segments and methacrylic acid blocks as hydrophilic segments were prepared. The polymers with low acid-value could not dissolve in the alkaline solution directly. They could dissolve in methyl-ethyl-ketone (MEK) at room temperature and diethylene glycol (DEG), with heating. Polymer aqueous solutions were successfully prepared using polymer solutions in DEG as the pre-solutions. Because they were also unable to dissolve directly even in an alkaline solution containing DEG, the existence of DEG is not important, but the process employing the pre-solution is important. The influence of pre-solution viscosity on solubility in water was evaluated. The result suggests that the high viscosity of the DEG solution would work to slowly disperse the polymers in the alkaline solution, efficiently converting polymers into an aqueous soluble state, owing to there being enough time for the neutralization of the carboxylic acids of the polymers. Note that in the pre-solution of a lower concentration, the aqueous solution did not become clear, and the larger particle sizes were detected. These results showed that the viscosity of the pre-solution is an essential factor in solubilization in water. Using this method, the polymeric dispersants with low hydrophilicity were well dissolved in water, up to a high concentration.
DOI	doi.org/10.3390/app13031834