Claims
- 1. Method for preparing a co-precipitated microcrystalline dispersion of dyes, the absorption spectrum of which exceeds the summoned spectra of individually dispersed dyes, which comprises, as consecutive preparation steps:adding to one vessel, an amount of at least one pentamethine oxonol barbituric acid filter dye having ionizable sites in its molecular structure; adding thereto an aqueous alkaline solution in an amount sufficient to completely dissolve the said filter dye while stirring the solution thus formed; adding in another vessel, to an amount of at least one pyrrole dye, an amount of water, followed by addition of an aqueous alkaline solution and a surfactant and, after having completely dissolved the said pyrrole dye, adding, while further stirring, to the solution of the pyrrole dye(s), the solution of the pentamethine oxonol barbituric acid dye(s); adding an aqueous acidic solution up to a pH of less than 3.0; adding an aqueous alkaline solution up to a pH in the range from 4.0 up to 5.5; and adding a binder.
- 2. Method according to claim 1, further comprising subjecting the dispersion to an ultrasonic treatment.
- 3. Method according to claim 1, wherein said dispersion is coated in a hydrophilic layer on a coating support or substrate after dilution of said dispersion.
- 4. Method according to claim 1, wherein said binder is selected from the group of compounds consisting of gelatin, colloidal silicic acid, polyvinyl pyrrolidone and starch, and mixtures thereof.
- 5. Method according to claim 1, whereinsaid pyrrole dye(s) is(are) represented by general formula (I) wherein n equals 0 or 1 wherein Q1 represents a phenyl ring or a thiophene ring; wherein Q2 represents a carbon, a nitrogen, a sulfur or an oxygen atom in order to provide a five-membered ring; a —N—C— or a —N—S— bond in order to provide a six-membered ring or a —N—C—C— chain in order to provide a seven-membered ring, wherein the said bond or chain representing Q2 is from C═O to N and wherein substituents present on the carbon atoms of the —N—C— bond representing Q2 or substituents on the carbon atoms of the —N—C—C— chain representing Q2 may close to form an unsaturated ring; and wherein R represents a member selected from the group consisting of a hydrogen atom, an alkyl, an alkenyl, an alkynyl, an aryl, a vinyl; C(═N—R1)—R2 CH═(N+) (—R3)2; CR 1=(N+) (—R2)2; C═N+ —O—; CO—H and the acetals and thioacetals derived therefrom; CO—NH—R3; CO—NH—SO2—R3 and the corresponding salts; CO—O—R3; CO—R3 and the acetals, thioacetals, aminals and 1,3-oxathiolans derived therefrom; CO—S—R3; CS—H; CS—NH—R3; CS—O—R3; CS—R3; CS—S—R3; F, Cl, Br, I, CN; N═C═N—R3; N═C═O; N═C═S; N═N(O)—R3; N═N—R3; NH—CO—NH—R3; NH—CO—R3; NH—CS—NH—R3; NH—CS—R3; NH—R3; NH—SO2—R ; NO2; NR1—CO—R2; NR1—CS—R2; NR32; O—CN; O—CO—R3; O—R3; O—SO2—R3; P(OR3)2; PO—(OR3)2; S—CN; S—CO—R3; S—CS—R3; S—R3; SO—R3; SO2—NHR3 and the salts derived therefrom; SO2—R3; SO3H and the salts derived therefrom; and wherein each of R1, R2 and R3 independently represents a member selected from the group consisting of a hydrogen atom, an alkyl, an alkenyl, an alkynyl, an aryl and a vinyl.
- 6. Method according to claim 1,wherein said pentamethine oxonol barbituric acid dye(s) is(are) represented by general formula (III) wherein each of R4 and R5, which may be the same or different, represents: hydrogen, C1-C4 alkyl, C1-C4 alkoxy, or substituted or unsubstituted aryl, and each of R6 and R7, which may be the same or different, represents: one of the groups represented by R4 and R5, or cycloalkyl.
- 7. Method according to claim 1, whereinthe at least one pyrrol dye and the at least one pentamethine oxonol barbituric acid dye are in molar ratio amounts of from 1:1 up to 3:1.
Priority Claims (1)
Number |
Date |
Country |
Kind |
01000093 |
Mar 2001 |
EP |
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Parent Case Info
This application claims the benefit of Provisional Application No. 60/293,266, filed May 23, 2001.
Foreign Referenced Citations (3)
Number |
Date |
Country |
0 724 191 |
Jul 1996 |
EP |
724191 |
Jul 1996 |
EP |
0 756 201 |
Jul 1996 |
EP |
Non-Patent Literature Citations (1)
Entry |
European Search Report EP01000093, Nov. 12, 2001. |
Provisional Applications (1)
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Number |
Date |
Country |
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60/293266 |
May 2001 |
US |