Composite absorbent particles

Patent metadata

Field	Value
Publication number	US-9253961-B2
Application number	US-201313758030-A
Country	US
Kind code	B2
Filing date	Feb 4, 2013
Priority date	Jul 11, 2003
Publication date	Feb 9, 2016
Grant date	Feb 9, 2016

Abstract

Composite particles and methods for making the same. An absorbent material is formed into a particle. An optional performance-enhancing active is coupled to the absorbent material before, during, or after the particle-forming process, homogeneously and/or in layers. Additionally, the composite absorbent particle may include a core material. Preferred methods for creating the absorbent particles include a pan agglomeration process, a high shear agglomeration process, a low shear agglomeration process, a high pressure agglomeration process, a low pressure agglomeration process, a rotary drum agglomeration process, a mix muller process, a roll press compaction process, a pin mixer process, a batch tumble blending mixer process, an extrusion process, and a fluid bed process.

First claim

What is claimed is:

1. A process for forming a plurality of porous composite particles suitable for use as an animal litter having a clump strength greater than 90%, said process comprising the steps of:
(a) introducing bentonite and powder activated carbon (PAC) into a pan agglomerator, a pin mixer or a Pelligrini mixer/Muller agglomerator combination;
(b) mixing the bentonite and PAC and optionally up to 20 weight percent water in the pan agglomerator, pin mixer or Pelligrini mixer/Muller agglomerator combination to form a plurality of bentonite-based porous composite particles wherein at least a portion of the PAC is encapsulated within the pores of the composite particles;
(c) drying the porous composite particles;
(d) sieving the porous composite particles to a predetermined particle size range suitable for use as an animal litter; wherein at least 80% of the porous composite particles formed fall within the predetermined particle size range after sequentially carrying out steps (a)-(d); and wherein
the clump strength, an indication of the percentage of particles retained in a clump after six hours upon addition of liquid, of the porous composite particles formed is greater than 90%.

2. The plurality of porous composite particles formed by the process recited in claim 1 , wherein the PAC is present in 0.5% in 0.1-5%.

3. The plurality of porous composite particles formed by the process recited in claim 1 , having a malodor rating less than 15 as determined by the Malodor Sensory Method.

4. The plurality of porous composite particles formed by the process recited in claim 1 having a malodor rating between 10 and 15 as determined by the Malodor Sensory Method.

5. The plurality of porous composite particles formed by the process recited in claim 1 having a hydraulic conductivity value of 0.25 cm/s or less.

6. The plurality of porous composite particles formed by the process recited in claim 1 , wherein the composite particles have a dusting attrition value of at most about 15% as measured by ASTM method E-728 Standard Test Method for Resistance to Attrition of Granular Carriers and Granular Pesticides.

7. The plurality of porous composite particles formed by the process recited in claim 1 , wherein the bentonite is sodium bentonite.

8. The plurality of porous composite particles formed by the process recited in claim 1 , wherein the bentonite has a mean particle diameter of about 25-150 μm.

9. The plurality of porous composite particles formed by the process recited in claim 1 , wherein the liquid is animal urine.

10. An improved animal litter comprising:
an absorbent material suitable for use as an animal litter; and
a plurality of porous composite particles formed by the process comprising the steps of:
(a) introducing bentonite and powder activated carbon (PAC) into a pan agglomerator, a pin mixer or a Pelligrini mixer/Muller agglomerator combination;
(b) mixing the bentonite and PAC and optionally up to 20 weight percent water in the pan agglomerator, pin mixer or Pelligrini mixer/Muller agglomerator combination to form a plurality of bentonite-based porous composite particles wherein at least a portion of the PAC is encapsulated within the pores of the composite particles;
(c) drying the porous composite particles;
(d) sieving the porous composite particles to a predetermined particle size range suitable for use as an animal litter; wherein at least 80% of the composite particles formed fall within the predetermined particle size range after sequentially carrying out steps (a)-(d); and wherein
the clump strength, an indication of the percentage of particles retained in a clump after six hours upon addition of liquid, of the porous composite particles formed is greater than 90%.

11. The improved animal litter recited in claim 10 having a malodor rating less than 15 as determined by the Malodor Sensory Method.

12. The improved animal litter recited in claim 10 having a malodor rating between 10 and 15 as determined by the Malodor Sensory Method.

13. The improved animal litter recited in claim 10 having a hydraulic conductivity value of 0.25 cm/s or less.

14. The improved animal litter recited in claim 10 , wherein the animal litter has a dusting attrition value of at most about 15% as measured by ASTM method E-728 Standard Test Method for Resistance to Attrition of Granular Carriers and Granular Pesticides.

15. The improved animal litter recited in claim 10 having a clump strength greater than 95%.

16. The improved animal litter recited in claim 10 , wherein the liquid is animal urine.

17. The improved animal litter recited in claim 10 , having a Multiple Cat Usage Index of at least 8.

18. The improved animal litter recited in claim 10 , wherein the bentonite in the porous composite particles is sodium bentonite.

19. The improved animal litter recited in claim 10 , wherein the bentonite has a mean particle diameter of about 25-150 μm containing 0.1-2% by weight PAC.

Assignees

• Clorox Co

Inventors

• Fritter Charles F
• Shenoy Ananth N

Classifications

• B01J20/324

  containing free carbon, e.g. activated carbon · CPC title

• B01J20/3204

  Inorganic carriers, supports or substrates · CPC title

• B01J20/20

  comprising free carbon; comprising carbon obtained by carbonising processes · CPC title

• B01J20/12

  Naturally occurring clays or bleaching earth · CPC title

• B01J20/28004

  Sorbent size or size distribution, e.g. particle size · CPC title