← Back to Patent Explorer
EP0361322A2 Expired / Lapsed EP ⏱️ 0.0 years remaining

Process for the precipitation of stable colloidal dispersions of base degradable components of photographic systems in the absence of polymeric steric stabilizers

Assignee: Eastman Kodak Co
•
Filing: 1989-09-22
•
Granted: —
•
Expires: 2009-09-22
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract The invention provides a method of forming a dispersion of base degradable hydrophobic component for a photographic system. The invention is accomplished by mixing the component, solvent, and surfactant, at an elevated temperature if necessary, metering the mixture of solvent, surfactant, and hydrophobic component to an excess of water with agitation so as to precipitate from the water solvent solution small particles of the hydrophobic component. The small particles then form a stable dispersion, after washing by dialysis or diafiltration, that will not agglomerate during storage prior to use. The preferred photographic component for use in the system of the invention is an ester terminated photographic coupler that would decompose if subjected to the high pH treatment of prior art procedures.

Inventors

  • 👤 Pranab C/O Eastman Kodak Company Bagchi

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-11-09 17:53
CPC Classifications
G; G03; G03C; G03C7/00; G03C7/30; G03C7/388; Y; Y10; Y10S; Y10S430/00; Y10S430/156; Y10S430/158

Claims Analysis

Total Claims: 12
Claim 1
Independent Claim 65 words
A method of forming a dispersion of a base degradable hydrophobic component for a photographic system characterized by mixing solvent, surfactant, and said hydrophobic component, metering the mixture of said solvent, surfactant and hydrophobic component into an excess of water with agitation, such that the said hydrophobic component precipitates in a fine stable colloidal dispersion, and recovering the fine particle dispersion of said hydrophobic component.
Claim 2
Independent Claim 65 words
A method of forming a dispersion of a base degradable hydrophobic component for a photographic system characterized by mixing solvent, surfactant, and said hydrophobic component, metering the mixture of said solvent, surfactant and hydrophobic component into an excess of water with agitation, such that the said hydrophobic component precipitates in a fine stable colloidal dispersion, and recovering the fine particle dispersion of said hydrophobic component.
Claim 3
Dependent Claim 17 words
The method of Claim 1 wherein said base degradable hydrophobic component comprises an ester terminated photographic coupler.
Claim 4
Dependent Claim 11 words
The method of Claim 1 wherein said solvent comprises n-propyl alcohol.
Claim 5
Dependent Claim 19 words
The method of Claim 1 wherein said surfactant comprises an alkyl or aryl ethoxylated half ester of sulfosuccinic acid.
Claim 6
Dependent Claim 17 words
The method of Claim 2 wherein the ester-terminated photographic coupler is selected from the group consisting of
Claim 7
Dependent Claim 20 words
The method of Claim 1 wherein said surfactant comprises disodium ethoxylated C-10 to C-12 alcohol half esters of sulfosuccinic acid.
Claim 8
Dependent Claim 16 words
The method of Claim 1 wherein said particles in dispersion are concentrated by dialysis or diafiltration.
Claim 9
Dependent Claim 14 words
The method of Claim 1 wherein said process is performed in a continuous manner.
Claim 10
Dependent Claim 14 words
The method of Claim 1 wherein the method is performed in a semicontinuous manner.
Claim 11
Dependent Claim 19 words
The method of Claim 1 wherein during said mixing of solvent, surfactant, and hydrophobic component the mixture is heated.
Claim 12
Dependent Claim 24 words
The method of Claim 1 wherein said base degradable hydrophobic component is selected from the group consisting of DIR and DIAR image modifying couplers.

References Cited (Backward Citations)

No citation records indexed.

USPTO Annuity & Maintenance Windows

Maintenance schedule is calculated for granted US utility patents.

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag