Friable shell microcapsules, process for preparing the same and method of use thereof

Abstract

The present application describes a microcapsule comprising: (i) a lipophilic core material, and (ii) a microcapsule shell, wherein microcapsule shell formed from oil-in-water emulsion polymerisation of monomer mixture consisting essentially of: (a) greater than 70 to about 99% by weight of at least one polyfunctional ethylenically unsaturated monomer, (b) about 1 to about 30% by weight of at least one unsaturated carboxylic acid monomer or its ester, and (c) about 0 to about 30% by weight of at least one vinyl monomer. Also provides process for preparing the same and its method of use in various applications.

Claims

1. A microcapsule comprising: i. a lipophilic core comprising a lipophilic core material, and ii. a friable and highly crosslinked microcapsule shell; wherein said microcapsule shell is formed from oil-in-water emulsion polymerisation of a monomer mixture consisting essentially of: (a) greater than 70 to about 99% by weight of pentaerythritol triacrylate (PETA) (b) about 1 to about 30% by weight of at least one unsaturated carboxylic acid monomer or its ester selected from the group consisting of acrylic acid, methacrylic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, 2-carboxylethyl acrylate, C1-C24 alkyl ester of acrylic acid, C1-C24 alkyl ester of methacrylic acid, and combinations thereof, and (c) about 0 to about 30% by weight of at least one vinyl monomer selected from the group consisting of N-vinyl pyrrolidone, N-vinyl caprolactam, 2-hydroxylethyl pyrrolidone methacrylate, octyl acrylamide, acryloxyethyltrimethyl ammonium chloride, 2-hydroxyethyl methacrylate and combinations thereof; and wherein the lipophilic core is encapsulated by the friable and highly crosslinked microcapsule.

2. The microcapsule according to claim 1, wherein said lipophilic core material is selected from the group consisting of fragrances, UV absorbers, emollient oils, insecticides, dyes, detergents, printing inks, perfumes, silicone conditioners, hair treatment/shampoo materials, biocides, adhesives, corrosion inhibitors, anti-fouling agents, flavors, cosmetic & personal care actives, oxidizing agents, pharmaceutical agents, agrochemicals/pesticides, lipids/fats, food additive, liquid crystals, coating materials. catalysts, preservatives and/or antimicrobial agents, lipophilic scale inhibitors, chemical reactants, rustproofing agents, recording materials, magnetic substances, and combinations thereof.

3. The microcapsule according to claim 1, wherein the friable and highly crosslinked microcapsule shell is formed from a monomer mixture consisting essentially of methacrylic acid and/or acrylic acid and pentaerythritol triacrylate (PETA).

4. The microcapsule according to claim I. wherein said unsaturated carboxylic acid monomer or its ester is present in an amount from about 10 to about 30% by weight of total monomers in polymer shell.

5. The microcapsule according to claim 1, wherein the friable and highly crosslinked microcapsule provides both retention and release of the lipophilic core material.

6. The microcapsule according to claim 1, wherein said microcapsule has a mean particle size of 1-2000 μm.

7. A process for preparing microcapsules comprising the steps of: A. preparing an oil phase comprising: i. a monomer mixture consisting essentially of: (a) greater than 70 to about 99% by weight of pentaerythritol triacrylate (PETA) (b) about 1 to about 30% by weight of at least one unsaturated carboxylic acid monomer or its ester selected from the group consisting of acrylic acid, methacrylic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, 2-carboxylethyl acrylate, C1-C24 alkyl ester of acrylic acid, C1-C24 alkyl ester of methacrylic acid, and combinations thereof, and (c) about 0 to about 30% by weight of at least one vinyl monomer selected from the group consisting of N-vinyl pyrrolidone, N-vinyl caprolactam, 2-hydroxylethyl pyrrrolidone methacrylate, octyl acrylamide, acryloxyethyltrimethyl ammonium chloride, 2-hydroxyethyl methacrylate and combinations thereof, and ii. at least one lipophilic core material; B. preparing a separate aqueous phase comprising at least one polymeric emulsion stabilizer and water; C. adding the oil phase of step (A) to the aqueous phase of step (B) under mechanical shear to form an oil-in-water emulsion; D. polymerizing the oil-in-water emulsion of step (C) through radical polymerisation by heating the emulsion to at least 80° C. and employing at least one initiator to produce core-shell microcapsules comprising an entrapped lipophilic core material and a friable and highly crosslinked polymer shell to result in a suspension of core-shell microcapsules in water.

8. The process according to claim 7, wherein the shell of the microcapsule consists essentially of: (a) greater than 70 to about 99% by weight of pentaerythritol triacrylate (PETA), (b) about 1 to about 30% by weight of at least one unsaturated carboxylic acid monomer or its ester, and (c) about 0 to about 30% by weight of at least one vinyl monomer.

9. The process according to claim 7, wherein the polymeric emulsion stabilizer is selected from the group consisting of cationic cellulose derivatives, quaternized gums, polyethylene imine, cationic polyacrylates and acrylamides, gelatin, quaternized protein hydrolysates, quaternized amino silicones, colloidal silica, hydroxyethyl cellulose, polyvinyl pyrrolidone, poly vinyl alcohol, styrene copolymer with maleic anhydride or acrylic acid, and a combination thereof.

10. The process according to claim 7, wherein the initiator is a theimal or redox initiator selected from the group consisting of dicetyl peroxydicarbonate, di(4-tert -butylcyclohexyl)peroxydicarbonate, dioctanoyl peroxide, dibenzoyl peroxide, dilauroyl peroxide, didecanoyl peroxide, tert-butyl peracetate, tert-butyl perlaurate, tert-butyl perbenzoate, tert-butyl hydroperoxide, cumene hydroperoxide, cumene ethylperoxide, diisopropylhydroxy dicarboxylate, 2,2′-azob is (2,4-dimethyl valeronitrile), 2,2′-azob is (is obutyronitrile), 1,1′-azob is (cyclohexane-1-carbonitrile), 2,2′azobis-(2-methylbutyronitrile), dimethyl 2,2′-azobis(2-methylpropionate), 2,2′-azobis[2-methyl-N-(2-hydroxyethyl) propionamide, and combinations thereof.

11. A consumer care composition comprising a microcapsule comprising: (i) a lipophilic core comprising a lipophilic core material, and (ii) a friable and highly crosslinked microcapsule shell, wherein said microcapsule shell is formed from oil-in-water emulsion polymerisation of a monomer mixture consisting essentially of (a) greater than 70 to about 99% by weight of pentaerythritol triacrylate (PETA) (b) about 1 to about 30% by weight of at least one unsaturated carboxylic acid monomer or its ester selected from the group consisting of acrylic acid, methacrylic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, 2-carboxylethyl acrylate, C1-C24 alkyl ester of acrylic acid, C1-C24 alkyl ester of methacrylic acid, and combinations thereof, and (c) about 0 to about 30% by weight of at least one vinyl monomer selected from the group consisting of N-vinyl pyrrolidone, N-vinyl caprolactam, 2-hydroxyle thyl pyrrrolidone methacrylate, octyl acrylamide, acryloxyethyltrimethyl ammonium chloride, 2-hydroxyethyl methacrylate and combinations thereof; wherein the lipophilic core is encapsulated by the friable and highly crosslinked microcapsule shell.

12. The consumer care composition according to claim 11, wherein said consumer care composition is a laundry care composition, a personal care composition, an all-purpose cleaner composition, a therapeutic composition, a cosmetic composition, a homecare & cleaning composition, pharmaceutical or cosmeceutical composition.

13. The consumer care composition according to claim 12, wherein said personal care composition is a hair shampoo, hair conditioner, rinse off or leave on composition for skin and hair, hair rinse, hair styling gel, hair colorant, hair removal depilatory, antiperspirant/deodorant, hand sanitizer, hand cream, hand lotion, liquid/solid soap, shower gel, body lotion, bar soap, body wash, sun protection product, preservative composition, sun and tissue regeneration scaffold, oral care, toothpaste, mouth wash and chewing gum, denture adhesive or dental care.

14. The consumer care composition according to claim 12, wherein the laundry care composition is a rinse conditioner, a liquid detergent, a solid detergent or a fabric refresher.

15. The consumer care composition according to claim 12, wherein the personal care composition is formed as a stick, roll-on or aerosol spray.

16. The consumer care composition according to claim 12, wherein the home care composition is a household cleaner, a hard surface cleaner, a carpet cleaner, a polish, or a sprayable composition.

17. A method of using a microcapsule comprising employing said microcapsule as a delivery matrix to deliver lipophilic core materials for industrial compositions that are related to agrochemicals, textiles, paper, mining, oil industry, water treatment, adhesives. coatings, plastics, sealants, construction, paints, inks and dyes onto different substrate surfaces such as skin, hair, or textiles, and wherein said microcapsule comprises: (i) at least one lipophilic core comprising a lipophilic core material, and (ii) a friable and highly crosslinked microcapsule shell, wherein said microcapsule shell is formed from oil-in-water emulsion polymerisation of a monomer mixture consisting essentially of: (a) greater than 70 to about 99% by weight of pentaerythritol triacrylate (PETA) (b) about 1 to about 30% by weight of at least one unsaturated carboxylic acid monomer or its ester selected from the group consisting of acrylic acid, methacrylic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, 2-carboxylethyl acrylate, C1-C24 alkyl ester of acrylic acid, C1-C24 alkyl ester of methacrylic acid, and combinations thereof, and (c) about 0 to about 30% by weight of at least one vinyl monomer selected from the group consisting of N-vinyl pyrrolidone, N-vinyl caprolactam, 2-hydroxylethyl pyrrrolidone methacrylate, octyl acrylamide, acryloxyethyltrimethyl ammonium chloride, 2-hydroxyethyl methacrylate and combinations thereof; wherein the lipophilic core is encapsulated by the friable and highly crosslinked microcapsule shell.

Description

EXAMPLES

(1) Example 1: Preparation of 70% by weight of PETA and 30% by weight of methacrylic acid shell:

(2) This example illustrates a process of preparing microcapsules by encapsulating a Fruity Accord fragrance material.

(3) An oil phase was prepared by diluting 101.1 g Fruity Accord (ex-Robertet) with 25.3 g of propylene glycol dicaprylate/caprate, followed by adding a monomer mixture comprising of 18.3 g of pentaerythritol triacrylate (PETA) and 7.8 g of methacrylic acid (MAA) to form an oil mixture, wherein 0.78 g of 2,2′azobis-(2-methylbutyronitrile) thermal initiator was dissolved in the oil mixture under mechanical stirring.

(4) Separately, an aqueous phase was prepared by dissolving 3.6 g of polyvinyl alcohol into 282.8 g deionized water by heating to 80° C. to form a polymer solution. The dissolved polymer solution was then cooled back to room temperature.

(5) The aqueous phase was transferred into a 600 ml beaker and to this was added the above prepared oil phase under a high shear mixer (Silverson LR5) to form an oil-in-water emulsion with a mean droplet particle sizes of around 20 microns. The formed oil-in-water emulsion was transferred to a 700 ml reaction flask submerged in a thermostatic bath and mechanically stirred. The emulsion was deoxygenated by bubbling nitrogen for 30 minutes. After, the de-oxygenation with nitrogen, the emulsion was heated up to 80° C. to induce thermal polymerization. The oil-in-water emulsion was left reacting for a total of 6 hours to form the microcapsule shell. Then, 0.3 g of 2,2′azobis-(2-methylbutyronitrile) was added to consume any residual impurities of the monomers.

(6) The resulting microcapsule slurry was an aqueous slurry of microcapsules in water and the distinct microcapsules were clearly visible under a light microscope. Using Malvern Mastersizer 2000 analyzer, the formed microcapsules had a volume weighted mean particle size diameter of 17.9 microns.

(7) Example 2 (Comparative Example): Fruity Accord microcapsules having polymer shell comprising of 20% weight tBAEMA and 80% weight BDDMA

(8) A comparative example was prepared by encapsulating the Fruity Accord fragrance material of Example 1 according to the disclosure of PCT patent application WO2012-075293. The experimental procedure used for preparing this comparative sample was described as follows:

(9) An oil phase was prepared by diluting 101.1 g Fruity Accord with 25.3 g of Propylene glycol dicaprylate/caprate, followed by adding 17.5 g of 1,4-butanediol dimethacrylate (BDDMA) and 8.6 g of t-butylaminoethyl methacrylate (tBAEMA) to form an oil phase. An amount of 0.78 g of 2,2′azobis-(2-methylbutyronitrile), thermal initiator, was dissolved in the oil phase.

(10) Separately, an aqueous phase was prepared by dissolving 3.6 g of polyvinyl alcohol into 282.8 g deionized water by heating to 80° C. and cooling back to room temperature.

(11) The above oil phase was added to the aqueous phase under a high shear mixer (Silverson LR5) to form an oil-in-water emulsion having a mean particle size of 20 microns. The formed emulsion was transferred to a 700 ml reaction flask submerged in a thermostatic bath and mechanically stirred. The emulsion was deoxygenated by bubbling nitrogen for 30 minutes. After, the bubbling with nitrogen, the emulsion was warmed to 80° C. to induce thermal polymerization. The mixture was left polymerizing for total of 6 hours. Then, 0.3 g of 2,2′azobis-(2-methylbutyronitrile) was added to consume any residual impurities of the monomers.

(12) The resulting microcapsule samples was an aqueous slurry of microcapsules in water with a volume weighted mean D [4,3] particle size diameter of 18.7 microns as measured by Malvern Mastersizer 2000 particle size analyzer.

(13) Example 3 (Comparative Example): Fruity Accord microcapsules having melamine formaldehyde polymer shell

(14) This example references preparation of microencapsulated Fruity Accord fragrance material with a melamine-formaldehyde polymer shell. The reference microcapsules were prepared by in-situ polymerization of melamine formaldehyde precondensate precursor according to Example 12 (preparation of Sample B) described in PCT patent application WO2012-075293 but in this case 140 g of Fruity Accord was used instead of the dyed isopropyl myristate oil.

(15) The resulting sample was an aqueous slurry of Fruity Accord microcapsules in water. Using Malvern Mastersizer 2000 analyzer, the microcapsules had a volume weighted mean particle size diameter of 19.0 microns.

(16) Example 4: Olfactory Performance of Fragrance Microcapsules

(17) The fragrance microcapsules of Examples 1, 2 and 3 were separately dosed into Ultra Downy Free & Gentle liquid fabric softener (P&G) at 0.35% fragrance material equivalents. Each of the three fabric softener formulations containing the respective microcapsules were then further split into two samples to allow storage at two different conditions; (i) 0 day at 23° C. and (ii) 4 weeks at 40° C.

(18) After each storage period (0 day or 4 weeks), the corresponding fabric softener sample was subjected to laundry protocol wash tests using a standard US front load washing machine. The experimental procedure involved washing cotton terry towels by normal wash cycle and the test fabric softener was auto dispensed into the washer during the rinse cycle. The laundered towels were line dried overnight, bagged, labeled and evaluated by trained panelists. The fragrance evaluation involved blind, randomized, panel of 30 assessors. Each assessor rated the fragrance intensity from a scale ranging from 0 to 9 before and after rubbing the dried terry towel. A score of 0 suggest no odor, and a score rating of 9 indicates a very strong odor.

(19) The olfactory performance results for the two different storage time/temperature samples are summarized in Table 1.

(20) From the sensory performance score rating results given in Table 1, it is clearly apparent that fragrance microcapsules of the present invention (Example 1) have higher score rating than the corresponding controls (Samples from Example 2 and 3). After 4 week's fabric softener storage at 40° C. and on laundry testing the inventive microcapsules exhibit still strong fragrance intensities; score rating of 7. This clearly demonstrates both retention of fragrance materials and the desired olfactory performance in use. It is inferred that the comparative microcapsules (Examples 2 & 3) leak some fragrances in fabric softeners and hence do not give the required fragrance performance in use.

(21) TABLE-US-00001 TABLE 1 Olfactory performance score rating of Fruity Accord microcapsules of Examples 1-3 Fabric softener storage Fabric softener storage 0 Day at 23° C. 4 weeks at 40° C. Before After Before After Microcapsule Sample rubbing rubbing rubbing rubbing Example 1-according 4.0 7.0 3.0 7.0 to present invention Comparative Sample 2.5 5.0 1.0 1.0 of Example 2 Comparative Sample 2.0 3.0 1.0 1.0 of Example 3

(22) Examples 5-10: Apple Accord and Floral Accord Fragrance Materials

(23) The experimental procedure outlined in Examples 1-3 were repeated with two other fragrance materials; Apple Accord and Floral Accord respectively. Table 2 summarizes each example, fragrance material used and the polymer shell chemistry of the resulting microcapsules.

(24) TABLE-US-00002 TABLE 2 Fragrance microcapsules details of Examples 5 to 10 Fragrance Example Example Description material Polymer Shell  5 According to invention Apple Accord 70/30; PETA/MAA  6 Comparative Apple Accord 80/20; BDDMA/ microcapsules tBAEMA  7 Comparative Apple Accord Melamine- microcapsules formaldehyde  8 According to invention Floral Accord 70/30; PETA/MAA  9 Comparative Floral Accord 80/20; BDDMA/ microcapsules tBAEMA 10 Comparative Floral Accord Melamine- microcapsules formaldehyde

(25) Following the same procedure and laundry testing protocol outlined in Example 4, the fragrance microcapsules of Example 5 to 10 were separately dosed into Ultra Downy Free & Gentle liquid fabric softener (P&G) at 0.35% fragrance equivalents respectively. Each of the respective fabric softener formulations containing the respective microcapsules were then further split into two samples to allow storage at two different conditions before laundry olfactory evaluation.

(26) Table 3 summarizes the olfactory performance results of the microcapsules of Example 5 to 10 from fabric softener after storage of the respective formulations at 0 days at 23° C. and after 4 weeks at 40° C.

(27) TABLE-US-00003 TABLE 3 Performance score rating of microcapsules prepared with Apple & Floral Accords Fabric softener Fabric softener storage storage 0 Days at 23° C. 4 weeks at 40° C. Before After Before After Microcapsule Sample rubbing rubbing rubbing rubbing Example 5 3 7 2 5 Comparative Example 6 1 4 1 1 Comparison Example 7 1 1 1 2 Example 8 2 7 2 6 Comparative Example 9 1 4 2 2 Comparative Example 10 2 2 1 2

(28) From Table 3 sensory score rating, the inventive microcapsules of Example 5 and Example 8 provide still good olfactory performance after prolonged storage of the microcapsules in fabric softener base, whereas, the comparative microcapsules give some olfactory performance initially but lose their efficacy on storage of fabric softener formulations after 4 week's storage at 40° C. demonstrating the retention of fragrance material in fabric softener formulations and desired release from laundered terry towels.

(29) Example 11: Preparation of microcapsules having polymer shell composition of 70% PETA, 15% methacrylic acid and 15% acrylic acid

(30) An oil phase was prepared by diluting 101.1 g Floral Accord with 25.3 g of mineral white oil, followed by adding monomer mixture comprising of 18.3 g of pentaerythritol triacrylate (PETA), 3.9 g of methacrylic acid (MAA) and 3.9 g of acrylic acid. To the resulting oil mixture was dissolved 0.78 g of 2,2′azobis-(2-methylbutyronitrile) thermal initiator under mechanical stirring.

(31) Separately, an aqueous phase was prepared by dissolving 3.6 g of polyvinyl alcohol into 282.8 g deionized water by heating to 80° C. The dissolved polymer solution was then cooled back to room temperature (approximately 20° C.). The aqueous phase was transferred into a 600 ml beaker and then added the above prepared oil phase under a high shear mixer (Silverson LR5) to form an oil-in-water emulsion. The formed oil-in-water emulsion was transferred to a 700 ml reaction flask submerged in a thermostatic bath and mechanically stirred. The emulsion was deoxygenated by bubbling nitrogen for 30 minutes. After de-oxygenation the emulsion was warmed to 80° C. to induce thermal polymerization. The oil-in-water suspension was left reacting for a total of 6 hours to form the microcapsule shell. Then, 0.3 g of 2,2′azobis-(2-methylbutyronitrile) was added to consume any residual impurities.

(32) The resulting product was an aqueous suspension of microcapsules in water. Under light microscope, distinct microcapsules are clearly visible having mean particle size diameter 26 microns. On application of pressure on the microscope slide cover slip, the microcapsule ruptured to release encapsulated fragrance material.

(33) Example 12: Preparation of microcapsules having polymer shell comprising of 80% weight PETA and 20% weight MAA and encapsulating Personal Care Fragrance Accord (PC Accord)

(34) Example 1 above was followed except the oil phase comprised of 101.1 g Personal Care Fragrance Accord (PC Accord) with 25.3 g of Propylene glycol dicaprylate/caprate, 20.9 g of pentaerythritol triacrylate (PETA), 5.2 g of methacrylic acid (MAA) and 0.78 g of 2,2′azobis -(2-methylbutyronitrile) thermal initiator.

(35) The resulting sample was an aqueous slurry of microcapsules in water. The volume weighted mean particle sizes of the microcapsules was determined to be 19.9 microns.

(36) Example 13: Olfactory performance of Example 12 microcapsules from Hair formulations

(37) (i) Leave-in Conditioner and (ii) Styling Gel

(38) The Personal Care Accord microcapsules of Example 12 were formulated separately into two consumer formulations; (i) a leave-in hair conditioner composition and a hair styling gel are given below.

(39) Leave-in hair conditioner composition containing PC Accord microcapsules

(40) TABLE-US-00004 Material % Weight Behenyl trimethyl ammonium 6.00 methosulfate + cetyl alcohol Stearyl alcohol 3.00 Olive oil 1.00 PC Accord Microcapsules 1.50 of Example 12 Glycerine 1.00 DMDM Hydantoin 0.10 Water q. s. ad 100%

(41) Hair styling gel composition containing PC Accord microcapsules

(42) TABLE-US-00005 % Material Weight Disodium EDTA 0.05 Amino methyl Propanol 0.03 Crosslinked poly(acrylic acid) 0.60 Acrylic Acid Copolymer 0.25 Polyvinylpyrrolidone 2.00 PC Accord Microcapsules 1.50 of Example 12 Propylene glycol, diazolidinyl 0.50 urea & Iodopropynl butycarbamate Water 95.07

(43) Both hair formulations of above were stored at 50° C. for 1 day and 43 days before testing on hair tresses separately following a standard hair testing protocol.

(44) Hair tresses (9 g) were first washed with shampoo, rinsed for 30 seconds under tap water at 37° C. before applying 0.5 g of the respective hair formulation. The hair tresses were left to dry in a controlled temperature/humidity conditions (23° C.±2 & 50%±5) overnight before olfactory evaluation.

(45) The intensity of the perception of the PC Accord on the hair tresses was evaluated by a panel of 6 panelists. Each panelist rating the hair tresses fragrance intensities before and rubbing; intensity rated on a scale ranging from 1 to 7. Where 1 score rating equates to no odor and 7 equates to very strong odour. The olfactory performance of the two aged hair products is summarized in the Table 4.

(46) TABLE-US-00006 TABLE 4 Fragrance performance from hair formulations after 1 & 43 days at 50° C. Formulation storage Consumer Formulation storage 43 days at 50° C. Hair for 1 day at 50° C. Before After Product Before rubbing After rubbing rubbing rubbing Leave-in 2.2 4.8 2.2 3.8 conditioner Hair 2.1 4.6 2.1 3.2 styling gel

(47) From the sensory results summarized in Table 6 it is inferred that the fragrance material is retained within the microcapsules in each hair compositions and subsequent on rubbing the hair tresses delivering the required fragrance bloom.

(48) Example 14: Powdered form microcapsules

(49) This example illustrated that dried powdered form of fragrance microcapsules can be produced by subjecting the aqueous slurry product to a spray drying process.

(50) The aqueous dispersion of Example 1 was spray dried using Buchi Mini-Spray Drier B-290 with inlet temperature of 190° C. and outlet temperature of 95° C. The recovered product was a free flowing powder. This can be formulated in anhydrous and non-aqueous formulations.

(51) Example 15: Encapsulation of an Epoxy compound (Neopentyl glycol diglycidyl ether)

(52) An oil phase was prepared by dissolving 0.2 g of the initiator 2,2′azobis-(2-methylbutyronitrile) with 2.0 g of methacrylic acid (MAA) and 4.6 g of the cross-linker pentaerythritol triacrylate (PETA). 25.3 g of the di-epoxide compound (neopentyl glycol di -epoxide) was then added to the oil phase. The resulting oil phase was added to the aqueous phase comprising of 45.5 g deionized water and 6.9 g of polyvinyl alcohol. The emulsion was allowed to stir for 5 minutes, to form a coarse pre-emulsion. The emulsion was then homogenized using a high shear mixer (Silverson LR5) to form an oil-in-water emulsion with a mean particle oil droplet size of 15-20 microns. The fine emulsion was transferred to a 1-litre reactor flask, degassed with nitrogen at room temperature for 30 min and warmed to 80° C. for 6 hours.

(53) The resulting microcapsule suspension was an aqueous suspension of microcapsules in water and was found to have a mean particle size of 20 microns under a light microscope.

(54) The dry microcapsules, which were dried from the aqueous slurry in an oven, were mixed with a di-amine in order to determine the reactivity of encapsulated di-epoxide compound. In parallel, the dry capsules were broken using shear and subsequently mixed with the same di-amine compound. In the absence of shear, i.e. the capsules were not broken, no significant reaction was observed. On the other hand, once the capsules were broken a hardened material was discovered proposing a reaction had occurred between the encapsulated di-epoxide compound and the added di-amine

(55) Example 16: Encapsulation of a UV Sunscreen (octocrylene)

(56) An oil phase was prepared by dissolving 1.31 g of 2,2′azobis-(2-methylbutyronitrile) thermal initiator into a monomer mixture comprising of 10.6 g methacrylic acid and 24.9 g of pentaerythritol triacrylate (PETA) crosslinking monomer. To this monomer mixture was dissolved 320.1 g of octocrylene (UV sunscreen). The resulting oil phase was added to an aqueous phase comprising of 13.6 g of polyvinyl alcohol and 428.9 g deionized water under a high shear mixer (Silverson LR5) to form an oil-in-water emulsion having mean particle oil droplets of around 3 microns.

(57) The formed oil-in-water emulsion was transferred to a 1-litre reactor flask, then deoxygenated with nitrogen and warmed to 85° C. for 6 hours to form the microcapsules.

(58) The resulting product formed is an aqueous suspension of microcapsules having encapsulated octocrylene. Under a light microscope, individual microcapsules are clearly observed with particle sizes of around 3 microns.

(59) Following are non-limiting examples of consumer formulations containing microcapsules of the present invention.

(60) Example 17: Microcapsules in fabric softener

Fabric Softener Composition

(61) TABLE-US-00007 Material % Weight Cationic surfactant (Esterquat) 6.20 Cationic rheology modifier 0.65 (Jaypol ®213) Phosphoric acid 0.045 Fragrance Microcapsules 2.50 of Example 1 Preservative/Dye q.s. Deionised Water q.s. ad 100%

(62) Example 18: Microcapsules in hair conditioner

Hair Conditioner Composition

(63) TABLE-US-00008 Material % Weight Disodium EDTA 0.02 Hydroxyethyl cellulose 0.50 Butyrospermum Parkii (Shea Butter) 10.00 Caprylic/Capric Triglyceride 5.00 Cetearyl Alcohol (and) Behenyl 5.00 Alcohol (and) Hydroxyethyl Cetearamidopropyldimonium Chloride Cetearyl alchol 3.00 2-hydroxyethyl-dimethyl-[3- 2.00 [[2R,3S,4R,5R)-2,3,4,5,6- pentahydroxyhexanoyl]amino]propyl]azanium chloride (and) 3-(D-Gluconoyl- amino)propyl(2-hydroxyethyl)dimethyl- ammonium chloride Fragrance microcapsules of Example 12 2.50 Preservative q.s. Deionised water q.s. ad 100%

(64) Example 19: Microcapsules in shower-rinse off product

Body Rinse Off Product Composition

(65) TABLE-US-00009 Material % Weight Glycerin 30.0 Disodium EDTA 3.00 Lightly crosslinked acrylates copolymer 0.10 Aqueous solution of Sodium Lauryl 48.0 (1EO) Sulfate @ 25% Sodium hydroxide @ 10% 1.20 Cocamidopropyl betaine 8.00 Sodium chloride @ 25% 0.02 Glycine based preservative 0.50 Fragrance Microcapsules of Example 12 3.75 Preservative/Dye q.s. Deionised water q.s. ad 100%

(66) Example 20: Microcapsules in antiperspirant/deordorant formulation

Antiperspirant/Deodorant Application—Aerosol Formulation

(67) TABLE-US-00010 Material % Weight Cyclomethicone 14.25 Diisopropyl Adipate 4.50 Disteardimonium Hectorite 0.25 Propylene Carbonate 0.25 Aluminum Chlorohydrate 5.00 Spray Dried Fragrance 0.75 Microcapsules of Example 14 Isobutane (and) propane propellant 75.00 Total 100.00

(68) Example 21: Microcapsules in Antiperspirant Stick

Antiperspirant Stick Composition

(69) TABLE-US-00011 Material % Weight Aluminium chlorohydrate 20.00 Cetyl alcohol 18.00 Stearic acid 18.00 Poly vinylpyrrolidone 1.00 Spray dried microcapsules 2.00 of Example 12 Cyclopentasilixane q.s. ad 100%

(70) While a number of embodiments of this invention have been represented, it was apparent that the basic construction can be altered to provide other embodiments that utilize the invention without departing from the spirit and scope of the invention. All such modifications and variations are intended to be included within the scope of the invention as defined in the appended claims rather than the specific embodiments that have been presented by way of example.