Layered silicate powder granules and method for producing the same

Patent metadata

Field	Value
Publication number	US-2019263667-A1
Application number	US-201716308249-A
Country	US
Kind code	A1
Filing date	Sep 4, 2017
Priority date	Sep 13, 2016
Publication date	Aug 29, 2019
Grant date	—

Abstract

The invention has for its object to use an evaporation-spray drying process thereby providing layered silicate powder granules, each one containing a flat particle having an opening or recess in its surface center. Each of the layered silicate powder granule contains a flat particle including a layered silicate formed by evaporation-spray drying and a rheology modifier for modifying the crystal edge face of the layered silicate and having an opening or recess in its surface center.

First claim

1 . A layered silicate powder granule comprising a flat particle, which comprises a layered silicate formed by evaporation-spray drying and a rheology modifier for modifying a crystal edge face of the layered silicate, and which has an opening or recess in its surface center.

2 . A layered silicate powder granule as recited in claim 1 , wherein the layered silicate has the following general formula:
[(E n+ ) a/n (M1 c M2 d )(Si 4-e Al e )O 10 (OH f F 2-f )]
where n is a natural number of 1 to 3; 0.1≤a≤0.8, 0≤c≤3, 0≤d≤2, 2≤c+d≤3, 0≤e<4, and 0≤f≤2; E is an interlayer n-valent cation and at least one atom selected from the group consisting of H, Li, Na, Mg, Ca, Zn, Sr, Fe, Ba, Ni, Cu, Co, Mn, Al, and Ga; and M1 and M2 are each a metal coming in an octahedron formed in a 2:1 type sheet, M1 being at least one metal selected from the group consisting of Mg, Fe, Mn, Ni, Zn, and Li, and M2 being at least one metal selected from the group consisting of Al, Fe, Mn, and Cr.

3 . A layered silicate powder granule as recited in claim 1 , wherein the layered silicate is at least one selected from the group consisting of smectites, swelling synthetic micas, and vermiculites.

4 . A layered silicate powder granule as recited in claim 3 , wherein the smectites are selected from montmorillonite, beidellite, nontronite, saponite, hectorite and stevensite.

5 . A layered silicate powder granule as recited in claim 3 , wherein the swelling synthetic micas are selected from Na-tetrasilisic mica or Na-taeniolite.

6 . A layered silicate powder granule as recited in claim 3 , wherein the vermiculites are selected from dioctahedral type vermiculite or trioctahedral type vermiculite.

7 . A layered silicate powder granule as recited in claim 1 , wherein the rheology modifier is an anionic compound.

8 . A layered silicate powder granule as recited in claim 1 , wherein the rheology modifier is used in an amount of 1 to 20 parts by mass per 100 parts by mass of the layered silicate.

9 . A layered silicate powder granule as recited in claim 1 , wherein the flat particle has an outer diameter of greater than 500 nm and less than 50 mm as observed and measured under a microscope, and a specific surface area (S t /V t ) of the flat particle that is defined by a surface area (S t ) to volume (V t ) ratio is 1.1 to 2.0 times as large as that of a sphere having the same volume.

10 . A layered silicate powder granule as recited in claim 9 , wherein the layered silicate powder granule contains 60% or greater of the flat particles (counted as a number of particles) and 20% or less of spherical particles (counted as a number of particles), and the flat particle has a maximum particle diameter of 50 mm or less.

11 . A method for producing a layered silicate powder granule containing a flat particle having an opening or recess in its surface center, wherein a suspension containing a layered silicate and a rheology modifier for modifying a crystal edge face of the layered silicate is sprayed in an atmosphere in which a dispersion medium evaporates, and the dispersion medium is evaporated and dried.

12 . A method for producing a layered silicate powder granule as recited in claim 11 , wherein droplets of a suspension containing a layered silicate and a rheology modifier for modifying a crystal edge face of the layered silicate are sprayed and blown onto a centrifugal disc, and a film of the suspension formed in a disc shape is scattered by fast rotation of the centrifugal disc, after which the dispersion medium is evaporated and dried.

13 . A method for producing a layered silicate powder granule as recited in claim 11 , wherein the layered silicate has the following general formula:
[(E n+ ) a/n (M1 c M2 d )(Si 4-e Al e )O 10 (OH f F 2-f )]
where n is a natural number of 1 to 3; 0.1≤a≤0.8, 0≤c≤3, 0≤d≤2, 2≤c+d≤3, 0≤e<4, and 0≤f≤2; E is an interlayer n-valent cation and at least one atom selected from the group consisting of H, Li, Na, Mg, Ca, Zn, Sr, Fe, Ba, Ni, Cu, Co, Mn, Al, and Ga; and M1 and M2 are each a metal coming in an octahedron formed in a 2:1 type sheet, M1 being at least one metal selected from the group consisting of Mg, Fe, Mn, Ni, Zn, and Li, and M2 being at least one metal selected from the group consisting of Al, Fe, Mn, and Cr.

14 . A method for producing a layered silicate powder granule as recited in claim 11 , wherein the layered silicate use is made of a layered silicate having a mean primary particle diameter of 10 nm to 100 nm as found by choosing particles at random, measuring one direction diameters of them along the crystal ab-axes under a microscope and taking an average.

15 . A method for producing a layered silicate powder granule as recited in claim 11 , wherein a suspension containing a layered silicate and a rheology modifier for modifying a crystal edge face of the layered silicate has a solid matter concentration of 0.1 to 20% by mass.

16 . A method for producing a layered silicate powder granule as recited in claim 11 , wherein layered silicate powder granules are heated at a temperature of 350 to 800° C.

17 . A functional powder for chromatography, adsorbents, drug delivery, catalysts, biologically active agent protection, pigments, or coatings, to which a layered silicate powder granule as recited in claim 1 is applied.

Assignees

• Nat Inst Materials Science

Inventors

• Sakuma Hiroshi
• Tamura Kenji

Classifications

• C01P2002/22

  layered hydroxide-type, e.g. of the hydrotalcite-type · CPC title

• C01P2004/02

  obtained by optical microscopy · CPC title

• C01P2004/64

  Nanometer sized, i.e. from 1-100 nanometer · CPC title

• C01P2004/24

  Nanoplates, i.e. plate-like particles with a thickness from 1-100 nanometer · CPC title

• C01B33/325 Primary

  After-treatment, e.g. purification or stabilisation of solutions, granulation; Dissolution; Obtaining solid silicate, e.g. from a solution by spray-drying, flashing off water or adding a coagulant · CPC title