Silicon dioxide solution preparation method, grinding fluid, and manufacture method of glass substrate

A silicon dioxide and solution technology, applied in chemical instruments and methods, record carrier manufacturing, other chemical processes, etc., can solve the problems of glass substrate damage, filter clogging, poor yield, etc., and achieve excellent smoothness, foreign matter and Damage reduction effect

Inactive Publication Date: 2013-11-20
ASAHI GLASS CO LTD
View PDF11 Cites 5 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] But, in the solution that is used as polishing liquid, contains abrasive grain (such as silicon dioxide particle etc.) in the process of production or preservation, under the situation that foreign matters such as coarse particle are mixed, use this polishing liquid to the main plane of glass substrate. When polishing, there are following problems that adversely affect the quality of the glass substrate for magnetic recording media: microscopic damage occurs on the surface of the glass substrate, and foreign matter adheres to the surface of the glass substrate and remains on the surface of the final product to become Defects, etc.
[0009] However, the method of Patent Document 1 has the following problems: colloidal silica with higher viscosity clogs the filter, and even colloidal silica particles are captured by the filter to reduce the recovery of colloidal silica ( poor yield), etc.
In the methods for removing foreign matter by centrifugation such as Patent Documents 2 and 3, the conditions of centrifugation are not optimized, and the removal of foreign matter is not sufficient.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Silicon dioxide solution preparation method, grinding fluid, and manufacture method of glass substrate
  • Silicon dioxide solution preparation method, grinding fluid, and manufacture method of glass substrate
  • Silicon dioxide solution preparation method, grinding fluid, and manufacture method of glass substrate

Examples

Experimental program
Comparison scheme
Effect test

preparation example Construction

[0044] (Preparation of Silica Solution)

[0045] The method for preparing a silica solution of the present invention can be used to remove foreign matter in a silica solution (hereinafter also referred to as a solution) obtained by dispersing silica particles and foreign matter in a solvent such as water or an organic solvent. In the present invention, the silica particles and foreign matter mainly exist dispersed in the solvent, but they may be partially dissolved in the solvent. The silica solution may contain additives or impurities other than silica particles and foreign matter. The solvent is not particularly limited, and examples thereof include water, alcohols such as methanol and isopropanol, organic solvents such as ethylene glycol and propylene glycol, and the like. Water is preferable from the viewpoint of easily dispersing the silica particles, and pure water, ultrapure water, ion-exchanged water, and the like are preferable from the viewpoint of less influence on...

Embodiment

[0085] Hereinafter, examples of the present invention will be specifically described, but the present invention is not limited to the examples. In addition, among the following Examples 1 to 9, Examples 1 to 5 are examples of the present invention, and Examples 6 to 9 are comparative examples.

[0086] In Examples 1 to 9, the foreign matter to be removed is diatomite, and its density ρ p 2.1 (g / cm 3 ), the solvent is water, the density ρ f 1(g / cm 3 ).

[0087] (Preparation of Silica Solution)

[0088] In Examples 1 to 9, a solution obtained by diluting a colloidal silica solution (a silica solution having an average primary particle diameter of silica particles of 30 nm) with pure water was used as the silica solution.

[0089] (Foreign matter removal treatment)

[0090] The equipment used in the foreign matter removal treatment is shown below.

[0091] Centrifugal separator A: (batch processing type, large-capacity cooling centrifuge HL-7α (manufactured by Coxan Co., L...

example 1

[0094] The colloidal silica solution was diluted with pure water so that the concentration of silica in the solution was 15% by mass, and sodium hydroxide was added to adjust the pH to 9. Put this solution into the rotor of centrifuge A until the height is 10cm (equivalent to the sedimentation distance), at 68588 (m / s 2 ) for 20 minutes (corresponding to the settling time), and the resulting solution was referred to as silica solution 1.

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

PropertyMeasurementUnit
particle diameteraaaaaaaaaa
densityaaaaaaaaaa
particle sizeaaaaaaaaaa
Login to view more

Abstract

The invention provides a silicon dioxide solution preparation method, grinding fluid, and a manufacture method of a glass substrate. The silicon dioxide solution preparation method is a silicon dioxide solution preparation method for removing foreign matters from a silicon dioxide solution containing silicon dioxide particles with a primary particle size of 1-80 nm, wherein the centrifugal acceleration G, the ratio of the sediment distance and the sediment time h / t, and the viscosity [eta] of the solution are controlled, thereby enabling the particle size Dp of the removed foreign matters to be 0.1-1 [mu]m. The grinding fluid is used in grinding of a main plane of the glass substrate for a magnetic recording medium, and contains the silicon dioxide solution prepared by the silicon dioxide solution preparation method enabling the particle size Dp of the removed foreign matters to be 0.1-1 [mu]m. The manufacture method of the glass substrate for the magnetic recording medium includes a procedure of using the grinding fluid to grind the main plane.

Description

technical field [0001] The present invention relates to a method for preparing a silicon dioxide solution, a polishing liquid containing the silicon dioxide solution prepared by the method for preparing the silicon dioxide solution, and a method for manufacturing a glass substrate for a magnetic recording medium using the polishing liquid. Background technique [0002] In recent years, in magnetic recording medium (hereinafter, also referred to as magnetic disk) devices, the increase in recording density has been rapidly advanced. For magnetic disk devices, random access is realized by scanning the magnetic head slightly on a high-speed rotating magnetic disk. In order to take into account high recording density and high-speed access, it is required to reduce the distance between the magnetic disk and the magnetic head (head flying height) and increase The rotational speed of the disk. [0003] For the base material of magnetic disks, aluminum (Al) coated with nickel-phosph...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Applications(China)
IPC IPC(8): C09K3/14G11B5/84
Inventor 志田德仁木村宏玉田稔
Owner ASAHI GLASS CO LTD
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap