Silica dispersion, method for preparing the same and method for making ink-jet recording material using the same

• US 6,403,162 B1
• Filed: 07/05/2000
• Issued: 06/11/2002
• Est. Priority Date: 07/07/1999
• Status: Active Grant

• Current Assignee: Mitsubishi Paper Mills Limited
• Original Assignee: Mitsubishi Paper Mills Limited
• Inventors: Ashida, Tetsuya, Tokunaga, Yukio, Sugita, Hajime
• Primary Examiner(s): CAMERON, ERMA C
• Application Number:
  US09/610,485
• Time in Patent Office: 706 Days
• Field of Search: 427/391, 427/379, 427/382
• US Class Current: 427/379
• CPC Class Codes: B41M 5/52 Macromolecular coatings
• CPC Class Codes: B41M 5/5218 characterised by inorganic additives, e.g. pigments, clays
• CPC Class Codes: B41M 5/5245 characterised by the use of polymers containing cationic or anionic groups, e.g. mordants
• CPC Class Codes: B41M 5/5254 characterised by the use of polymers obtained by reactions only involving carbon-to-carbon unsaturated bonds, e.g. vinyl polymers

Abstract

Disclosed are a method for making an ink-jet recording material which comprises adding silica fine particles having an average primary particle diameter of 50 nm or less to a dispersion medium mainly comprising water containing a cationic polymer having a weight average molecular weight of 100,000 or less and mixing to prepare a slurry of silica fine particles; dispersing the slurry of silica fine particles by a dispersing machine to prepare a dispersion of silica fine particles; mixing the dispersion of silica fine particles with at least a hydrophilic binder to prepare a coating solution for forming an ink-receptive layer; and coating the coating solution for forming an ink-receptive layer on a support and drying, a method for preparing a dispersion of silica fine particles and the silica dispersion.

Claims

1. A method for making an ink-jet recording material comprising the steps of:

adding fumed silica fine particles having an average primary particle diameter of 50 nm or less to a dispersion medium mainly comprising water containing a cationic polymer having a weight average molecular weight of 100,000 or less and mixing to prepare a slurry of fumed silica fine particles;

dispersing said slurry of fumed silica fine particles by a dispersing machine to prepare a dispersion of fumed silica fine particles;

mixing said dispersion of fumed silica fine particles with at least a hydrophilic binder to prepare a coating solution for forming an ink-receptive layer; and

coating said coating solution for forming an ink-receptive layer onto a support and drying.

2. The method for making an ink-jet recording material according to claim 1, wherein the cationic polymer has a weight average molecular weight of 2,000 to 50,000.

3. The method for making an ink-jet recording material according to claim 1, wherein the cationic polymer is a cationic polymer having a diallyl amine structure as a constitutional unit.

4. The method for making an ink-jet recording material according to claim 1, wherein the fumed silica fine particles are prepared by a gas phase process having an average primary particle diameter of 3 to 15 nm.

5. The method for making an ink-jet recording material according to claim 1, wherein a time from the preparation of the dispersion of fumed silica fine particles to the time of coating the coating solution for forming an ink-receptive layer is at least 5 hours.

6. The method for making an ink-jet recording material according to claim 1, wherein a step of heat treatment at 50°

C. or higher is carried out after the step of dispersing said slurry of fumed silica fine particles and before the step of coating said coating solution.

7. A method for making a coating solution for forming an ink-receptive layer to be used for the process according to claim 1, which comprises the steps of:

adding fumed silica fine particles having an average primary particle diameter of 50 nm or less to a dispersion medium mainly comprising water containing a cationic polymer having a weight average molecular weight of 100,000 or less and mixing to prepare a slurry of fumed silica fine particles; and

dispersing said slurry of fumed silica fine particles by a dispersing machine to prepare a dispersion of fumed silica fine particles; and

mixing said dispersion of fumed silica fine particles with at least a hydrophilic binder.

8. The method for making an ink-jet recording material according to claim 1, wherein the coating solution is prepared by preparing a dispersion of fumed silica fine particles, allowing the dispersion to stand for 5 hours or longer, and mixing the dispersion with at least a hydrophilic binder.

9. The method for making an ink-jet recording material according to claim 1, wherein the coating solution is prepared by preparing a dispersion of fumed silica fine particles, subjecting the dispersion to heat treatment at 50°

C. or higher, and mixing the dispersion with at least a hydrophilic binder.