Aqueous ink for ink-jet printing

• US 6,031,019 A
• Filed: 02/04/1998
• Issued: 02/29/2000
• Est. Priority Date: 02/07/1997
• Status: Expired due to Term

• Current Assignee: KAO Corporation
• Original Assignee: KAO Corporation
• Inventors: Tsutsumi, Takehiro, Azuma, Koji, Wakabayashi, Shigemi, Ueno, Tetsuya, Kaida, Kenji, Sawada, Michitaka, Sakuma, Tadashi, Kawabe, Kuniyasu
• Primary Examiner(s): Jagannathan, Vasu
• Assistant Examiner(s): Shosho, Callie E.
• Application Number:
  US09/018,844
• Time in Patent Office: 755 Days
• Field of Search: 523/160, 523/161, 106/31.13, 106/31.25, 106/31.27, 106/31.32, 106/31.33, 106/31.57, 525/479, 525/279, 525/312, 525/287, 525/309, 525/475, 526/307.5, 526/307.7, 526/276, 526/279
• US Class Current: 523/160
• CPC Class Codes: C08F 283/12 on to polysiloxanes
• CPC Class Codes: C09D 11/30 Inkjet printing inks

Abstract

Aqueous ink for ink-jet printing comprises an emulsion of fine polymer particles and contains at least one compound selected from an amino acid or a salt thereof and the like.

Claims

1. An aqueous ink for inkjet printing comprising a polymer emulsion and at least one compound selected from the group consisting of an amino acid or a salt thereof and substantially water-soluble compounds represented by formula (1) and (2):

##STR8## wherein R₁, R₂, and R₃, which may be the same or different, each represent a hydrogen atom, a hydrocarbon group having 1 to 5 carbon atoms or an acyl group which may be substituted by an amino group;

R represents an alkylene group having 1 to 5 carbon atoms which may be substituted by a branched group; and

M represents a hydrogen atom, an alkali metal atom or an alkaline earth metal atom.

2. The aqueous ink for ink-jet printing according to claim 1, wherein said polymer emulsion is an emulsion of fine polymer particles impregnated with a water-insoluble or sparingly water-soluble colorant.

3. The aqueous ink for ink-jet printing according to claim 1, wherein the polymer of said polymer emulsion comprises a vinyl polymer or a polyester.

4. The aqueous ink for ink-jet printing according to claim 1, wherein said vinyl polymer is obtainable by copolymerizing:

(i) at least one monomer selected from the group consisting of a silicone macromer represented by formula (4);

space="preserve" listing-type="equation">X(Y).sub.n Si(R.sub.5).sub.3-m (Z).sub.m (

     4)

wherein X represents a polymerizable unsaturated group;

Y represents a divalent linking group;

R₅ represents a hydrogen atom, a lower aflkyl group, an aryl group or an alkoxy group;

a plurality of R₅ '"'"'s may be the same or different;

Z represents a monovalent siloxane polymer moiety having a number average molecular weight of at least about 500;

n represents 0 or 1; and

m represents an integer of 1 to 3,

an acrylamide monomer and a methacrylamide monomer not having a salt-forming group,

(ii) a polymerizable unsaturated monomer having a salt-forming group, and

(iii) a monomer copolymerizable with monomers (i) and (ii) in the presence of a radical polymerization initiator.

5. The aqueous ink for ink-jet printing according to claim 1, wherein said polyester contains in the polyester chain thereof a unit derived from a diol component represented by formula (6):

##STR9## wherein R₇ represents an alkyl group having 1 to 4 carbon atoms;

A represents an alkylene group having 2 to 4 carbon atoms;

s and t, which may be the same or different, each represent an integer of 1 or more; and

the sum of s and t averages 2 to 10.

6. The aqueous ink for ink-jet printing according to claim 1, wherein the at least one compound is an amino acid or a salt thereof.

7. The aqueous ink for ink-jet printing according to claim 6, wherein the amino acid or a salt thereof is β

-alanine, proline, γ

-aminobutyric acid, arginine, or glycine.

8. The aqueous ink for ink-jet printing according to claim 7, wherein the amino acid or a salt thereof is β

-alanine, γ

-aminobutyric acid, arginine, or proline.

9. The aqueous ink for ink-jet printing according to claim 1, wherein the at least one compound is the compound represented by formula (1).

10. The aqueous ink for ink-jet printing according to claim 9, wherein the compound of formula (1) is N-methylglycine, N,N-dimethylglycine, N-ethylglycine, N-acetylglycine, or glycylglycine.

11. The aqueous ink for ink-jet printing according to claim 10, wherein the compound of formula (1) is N-methylglycine.

12. The aqueous ink for ink-jet printing according to claim 1, wherein the at least one compound is the compound represented by formula (2).

13. The aqueous ink for ink-jet printing according to claim 12, wherein the compound of formula (2) is N,N,N-trimethylglycine, α

-propiobetaine, or γ

-butyrobetaine.

14. The aqueous ink for ink-jet printing according to claim 13, wherein the compound of formula (2) is N,N,N-trimethylglycine.