Emulsion binder, aqueous pigment ink for inkjet containing same, and method for producing emulsion binder

{
  "publication_number": "US2013338273A1",
  "country": "US",
  "kind": "A1",
  "title": "Emulsion binder, aqueous pigment ink for inkjet containing same, and method for producing emulsion binder",
  "abstract": "Disclosed is an emulsion binder containing an A-B block copolymer. The A-B block copolymer has a number average molecular weight of 5,000 to 100,000, and a polydispersity index (weight average molecular weight/number average molecular weight) of not greater than 1.7. The polymer block A has an acid value of 0 to 30 mgKOH/g and a glass transition point of not higher than 60° C. The polymer block B has an acid value of 75 to 250 mgKOH/g. The A-B block copolymer has been neutralized with an alkaline material, and has been allowed to self-emulsify in an aqueous medium to form emulsion particles having an average particle size of 30 to 300 nm.",
  "claims": [
    "1. An emulsion binder comprising an A-B block copolymer formed of a polymer block A and another polymer block B, at least 90 mass % of constituent monomer units of said A-B block copolymer having been derived from at least one (meth)acrylate-based monomer, wherein: the A-B block copolymer has a number average molecular weight of 5,000 to 100,000 and a polydispersity index (weight average molecular weight/number average molecular weight) of not greater than 1.7, the polymer block A has an acid value of 0 to 30 mgKOH/g and a glass transition point of not higher than 60° C., the polymer block B has an acid value of 75 to 250 mgKOH/g, and the A-B block copolymer has been neutralized with an alkaline material, and has been allowed to self-emulsify in an aqueous medium to form emulsion particles having a number average particle size of 30 to 300 nm. 2. A water-based inkjet pigment ink comprising a pigment and a film-forming binder, wherein: the film-forming binder is the emulsion binder according to claim 1. 3. The water-based inkjet pigment ink according to claim 2, wherein: pigment is at least one pigment selected from the group consisting of Color Index Numbers (C.I.) Pigment Blue 15:3 and 15:4; C.I. Pigment Red 122 and 269; C.I. Pigment Violet 19; C.I. Pigment Yellow 74, 155, 180 and 183; C.I. Pigment Green 7, 36 and 58; C.I. Pigment Orange 43; C.I. Pigment Black 7; and C.I. Pigment White 6, and has a number average primary particle size of smaller than 350 nm, and based on 100 mass % total amount of the ink, the pigment is contained at a content of 4 to 15 mass % and the film-forming binder is contained at a content of 5 to 20 mass %. 4. A process for producing the emulsion binder according to claim 1, comprising the following step: subjecting the (meth)acrylate-based monomer to living radical polymerization by using at least an iodine compound as a polymerization initiator compound, thereby synthesizing the A-B block copolymer. 5. The process according to claim 4, wherein the A-B block copolymer is synthesized using, as a catalyst, at least one compound selected from the group that consists of phosphorus-containing compounds consisting of phosphorus halides, phosphite-based compounds and phosphinate compounds, nitrogen-containing compounds consisting of imide-based compounds, oxygen-containing compounds consisting of phenol-based compounds, and hydrocarbon compounds consisting of diphenyl methane-based compounds and cyclopentadiene-based compounds. 6. The process according to claim 4, wherein the living radical polymerization is conducted at a polymerization temperature of 30 to 50° C. 7. The process according to claim 4, wherein subsequent to the living radical polymerization in a water-soluble organic solvent, an alkaline material is added for neutralization, and water is then mixed to induce self-emulsification of the A-B block copolymer."
  ],
  "description_excerpt": "This invention relates to an emulsion binder suited as a film component in the inkjet printing method, a water-based inkjet pigment ink containing the emulsion binder, and a process for producing the emulsion binder.\n\nThe application of inkjet printers varies widely with the movement in recent years toward those having higher functions. Their application is expanding further, for example, not only as those for personal use, office use, business use, recording, colored presentation and color photos but also as industrial inkjet printers. For industrial inkjet printers in particular, it is required especially to meet high-speed printing. Concerning water-based pigment inks for use in such inkjet printers, the ultrafine division of pigment particles has proceeded to make improvements in brilliance, color clearness, color density and so on. On the other hand, the miniaturization of ejected droplets (ink droplets) has also proceeded to meet the movement toward printing of higher speed and higher quality through improvements in printer apparatus. These improvements have brought about excellent high-quality image quality for converted papers for inkjet printing, especially photographic papers, wide format papers, and the like. Nonetheless, these improvements have not advanced to such an extent as to apply the inkjet printing method to printing on papers of various qualities. A new problem has arisen especially in that depending on the kind of paper, the printed ink may flake off when rubbed.",
  "cpc": [
    "C08F 299/0414",
    "C08F 293/005",
    "C09D 11/107",
    "C09D 11/322",
    "Y10T 428/2982"
  ],
  "ipc": [
    "B41J 2/01",
    "B41M 5/00",
    "C08F 265/06",
    "C08F 299/04",
    "C08F 4/00",
    "C08F 6/02",
    "C09D 11/00",
    "C09D 11/322",
    "C08F 293/00",
    "C09D 11/107",
    "G03G 9/00"
  ],
  "assignees": [
    "Dainichiseika Color and Chemicals Mfg Co Ltd",
    "Kyoto University NUC"
  ],
  "inventors": [
    "Hiroyuki Shimanaka",
    "Yoshikazu Murakami",
    "Shinichio Aoyagi",
    "Atsushi Goto",
    "Hironori Kaji"
  ],
  "filing_date": "2011-11-28",
  "publication_date": "2013-12-19",
  "priority_date": "2011-03-15",
  "application_number": "US-201114001824-A",
  "family_id": "46830313",
  "cited_by_count": 45,
  "citations": [
    "WO2010013651A1",
    "US20110223529A1"
  ]
}