Silica microcapsules and methods of preparing same

Patent metadata

Field	Value
Publication number	US-12396958-B2
Application number	US-202117490576-A
Country	US
Kind code	B2
Filing date	Sep 30, 2021
Priority date	Mar 18, 2016
Publication date	Aug 26, 2025
Grant date	Aug 26, 2025

Abstract

Disclosed is a microcapsule containing: (i) a microcapsule core having an active material, and (ii) a microcapsule wall formed of a first polymer and second polymer. The first polymer is a sol-gel polymer. The second polymer is gum arabic, purity gum ultra, gelatin, chitosan, xanthan gum, plant gum, carboxymethyl cellulose, sodium carboxymethyl guar gum, or a combination thereof. The weight ratio between the first and second polymer is 1:10 to 10:1. Also disclosed are processes for preparing the microcapsule and uses of the microcapsules in consumer products.

First claim

What is claimed is:

1. A process for preparing microcapsules comprising a core containing an active material and a wall, the process comprising
(a) providing a mixture that contains (i) a polysiloxane having a molecular weight of 1000-9000, (ii) gum arabic, (iii) gelatin, and (iv) a plurality of oil droplets dispersed in an aqueous phase, in which the oil droplets are sized from 1 to 250 μm and contain an active material;
(b) maintaining the pH of the mixture at 1 to 6 to obtain a microcapsule slurry; and
(c) curing the microcapsule slurry, thereby obtaining microcapsules comprising a core containing an active material and a wall.

2. The process of claim 1 , further comprising obtaining the polysiloxane by reacting water with a sol-gel precursor selected from a silicon alkoxide monomer or an alkoxysilane monomer corresponding to the general formula: (R 1 O)(R 2 O)Si(X)(X′) wherein X is hydrogen, —OR 3 , or R 4 ; X′ is hydrogen, —OR 5 or R 6 ; and each of R 1 , R 2 , R 3 , R 4 , R 5 , and R 6 , independently, is H, a linear, branched or cyclic alkyl group, or a linear, branched or cyclic siloxane group; and wherein the molar ratio between water and the sol-gel precursor is 1:3 to 3:1.

3. The process of claim 2 , wherein the sol-gel precursor is tetramethyl orthosilicate, tetraethyl orthosilicate, or a combination thereof.

4. The process of claim 1 , further comprising the step of removing water to dry the microcapsule.

5. The process of claim 1 , wherein the polysiloxane has the formula of (R 10 )[Si(X) a (X′) 2-a O] n R 2 , wherein
X is hydrogen, —OR 3 , or R 4 ;
X′ is hydrogen, —OR 5 or R 6 ,
a is 0-2,
n is an integer from 100 to 1200, and
each of R 1 , R 2 , R 3 , R 4 , R 5 , and R 6 , independently, is H, a linear, branched or cyclic alkyl group, or a linear, branched or cyclic siloxane group.

6. The process of claim 1 , wherein the microcapsule is single-layered.

7. The process of claim 1 , wherein the microcapsule is multi-layered.

Assignees

• Int Flavors & Fragrances Inc

Inventors

• Brahms John
• Gabbard Ronald
• Geng Feng
• Wieland Julie Ann
• Xu Li
• Popplewell Lewis Michael

Classifications

• A23F3/18

  Extraction of water soluble tea constituents ({A23F3/166 takes precedence; } isolation of tea flavour or tea oil A23F3/42) · CPC title

• A23F3/14

  Tea preparations, e.g. using additives (flavouring A23F3/40) · CPC title

• A23F3/12

  Rolling or shredding tea leaves · CPC title

• B01J13/206

  Hardening; drying · CPC title

• B01J13/08

  Simple coacervation, i.e. addition of highly hydrophilic material {(combined with spraying B01J13/043; combined with mechanical division B01J13/04)} · CPC title