Polyurea capsules prepared with aliphatic isocyanates and amines

Patent metadata

Field	Value
Publication number	US-9687424-B2
Application number	US-201313969038-A
Country	US
Kind code	B2
Filing date	Aug 16, 2013
Priority date	Sep 18, 2009
Publication date	Jun 27, 2017
Grant date	Jun 27, 2017

Abstract

Polyurea capsules that encapsulate active materials in polymeric walls resulting from the polymerization of an aliphatic polyisocyanate and a cross-linking agent such as a diamine, amphoteric amine or guanidine amine/salt are provided as are consumer products containing said polyurea capsules and for methods for producing such capsules.

First claim

What is claimed is:

1. A method for preparing a polyurea capsule composition comprising:
(a) preparing an oil phase comprising an active material and a polyisocyanate in which the active material is a fragrance oil;
(b) preparing a surfactant solution containing a capsule formation aid that is a mixture of polyvinyl alcohol and carboxymethyl cellulose;
(c) emulsifying the oil phase into the surfactant solution to form a fragrance emulsion;
(d) adding a cross-linking agent to the fragrance emulsion to form a capsule slurry; and
(e) curing the capsule slurry,

wherein the active material is present at a level of 5% to 80% of the polyurea capsule composition; the polyisocyanate is present at a level of 1% to 7.5% of the polyurea capsule composition; the capsule formation aid is present at a level of 0.25% to 2% of the polyurea capsule composition; the cross-linking agent, being a guanidine salt, is present at a level of 0.25% to 3% of the polyurea capsule composition; the polyurea capsule composition contains a microcapsule having an encapsulating polymer that encapsulates the active material; and the encapsulating polymer is the polymerization product between the polyisocyanate and the cross-linking agent in the presence of the capsule formation aid.

2. The method of claim 1 , wherein the polyisocyanate is an aromatic polyisocyanate or aliphatic polyisocyanate.

3. The method of claim 2 , wherein the aliphatic polyisocyanate is a dimer, biuret, symmetric trimer, or asymmetric trimer of hexamethylene diisocyanate.

4. The method of claim 1 , wherein the guanidine salt is 1,3-diaminoguanidine monohydrochloride, 1,1-dimethylbiguanide hydrochloride, guanidine carbonate or guanidine hydrochloride.

5. The method of claim 4 , further comprising addition of sodium carbonate to the fragrance emulsion.

6. The method of claim 1 , wherein the step of adding the cross-linking agent to the fragrance emulsion is at a temperature of 35° C.

7. The method of claim 1 , wherein the step of adding the cross-linking agent to the fragrance emulsion is at a temperature of 22° C.

8. The method of claim 1 , wherein the capsule slurry is cured at a temperature greater than 55° C., 65° C., 75° C., 85° C. or 95° C.

9. The method of claim 1 , wherein the step of curing the capsule slurry is carried out in the presence of a catalyst.

10. The method of claim 1 , further comprising the step of washing the cured capsule slurry with water.

11. The method of claim 10 , further comprising the step of adding a salt to the cured capsule slurry before washing the capsule slurry with water.

Assignees

• Int Flavors & Fragrances Inc
• Int Flavors & Fragrances Inc

Inventors

• Lei Yabin
• Xu Li
• Joyce Carol
• Popplewell Lewis Michael

Classifications

• A61K2800/412

  Microsized, i.e. having sizes between 0.1 and 100 microns · CPC title

• A61K8/11 Primary

  Encapsulated compositions · CPC title

• A61Q5/00

  Preparations for care of the hair · CPC title

• A61K8/731

  Cellulose; Quaternized cellulose derivatives · CPC title

• A61Q5/12

  Preparations containing hair conditioners · CPC title