Reloadable microcapsules

Abstract

A reloadable microcapsule contains a microcapsule core and a microcapsule wall encapsulating the microcapsule core. The microcapsule core contains a hydrophobic core solvent and a hydrophilic core solvent, and the microcapsule wall, formed of an encapsulating polymer, is permeable to the hydrophilic core solvent. Also disclosed are methods of preparing the reloadable microcapsule and consumer products having the microcapsules.

What is claimed is: 
     
         1 . A microcapsule comprising a microcapsule core and a microcapsule wall encapsulating the microcapsule core,
 wherein
 the microcapsule wall, formed of an encapsulating polymer, is permeable to the hydrophilic core solvent, and 
 the microcapsule core contains by weight of the core 1 to 99% of the hydrophilic solvent and 1 to 99% of the hydrophobic solvent, preferably 10 to 90% of the hydrophilic solvent and 10 to 90% of the hydrophobic solvent, more preferably 25 to 75% of the hydrophilic solvent and 25 to 75% of the hydrophobic solvent, and most preferably 40 to 60% of the hydrophilic solvent and 40 and 60% of the hydrophobic solvent. 
   
     
     
         2 . The microcapsule of  claim 1 , wherein the microcapsule core is free of an active material; the hydrophilic core solvent has a water solubility of 1 to 100 g/L, a weighted Hansen solubility parameter of 18 or greater, a Hansen polarizability of 4 or greater, and a Hansen h-bonding value of 5 or greater; and the hydrophobic core solvent has a weighted Hansen solubility parameter of 18 or less, a Hansen polarizability of 4 or less, and a Hansen h-bonding value of 5 or less. 
     
     
         3 . The microcapsule of  claim 2 , wherein the hydrophilic core solvent has a vapor concentration at 25° C. of 4 μg/L or greater; and the hydrophobic core solvent has a vapor concentration at 25° C. of 0.1 μg/L or less. 
     
     
         4 . The microcapsule of  claim 1 , wherein the microcapsule has a size of 0.1 to 1000 μm in diameter, the weight ratio between the hydrophobic core solvent and the hydrophilic core solvent is 1:9 to 9:1, and the weight ratio between the microcapsule core and the microcapsule wall is 50:1 to 1:1. 
     
     
         5 . The microcapsule of  claim 2 , wherein the hydrophilic core solvent is triethyl citrate, triacetin, benzyl acetate, benzyl benzoate, ethyl acetate, propylene glycol, dipropylene glycol, dipropylene glycol methyl ether, a glycol ether, or a combination thereof; and the hydrophobic core solvent is a C 3 -C 40  ester, isopropyl myristate, C 5 -C 50  triglyceride, D-limonene, silicone oil, mineral oil, isopropyl palmitate, isoparaffinic hydrocarbon, methyl hydrogenated rosinate, dioctyl adipate, or a combination thereof. 
     
     
         6 . The microcapsule of  claim 1 , wherein the hydrophobic solvent is a fragrance ingredient having a ClogP of 2.5 or greater and a vapor concentration at 25° C. of 0.1 μg/L or less, and the hydrophilic core solvent has a vapor concentration at 25° C. of 4 μg/L or greater. 
     
     
         7 . The microcapsule of  claim 1 , wherein the encapsulating polymer is a polyacrylate, polyurea, polyurethane, polyacrylamide, polyester, polyether, polyamide, poly(acrylate-co-acrylamide), starch, silica, gelatin and gum Arabic, alginate, chitosan, polylactide, poly(melamine-formaldehyde), poly(urea-formaldehyde), or combination thereof. 
     
     
         8 . The microcapsule of  claim 7 , wherein the encapsulating polymer is a polyurea, the microcapsule core contains a C 1 -C 30  alcohol or thiol, the polyurea is a reaction product of a polyisocyanate and a polyamine, the polyisocyanate is a trimer of hexamethylene diisocyanate, a trimer of isophorone diisocyanate, a biuret of hexamethylene diisocyanate, a polyisocyanurate of toluene diisocyanate, a trimethylol propane-adduct of toluene diisocyanate, a trimethylol propane-adduct of xylylene diisocyanate, or a combination thereof, and polyisocyanate is hexamethylene diamine, branched polyethylenimine, guanidine, or a combination thereof. 
     
     
         9 . A microcapsule composition comprising the microcapsule of  claim 1  and a continuous phase that has an external hydrophilic solvent and an active material, wherein the microcapsule wall is permeable to the active material, the ratio between the microcapsule core and the active material is 1:99 to 99:1, and the active material is selected from the group consisting of a fragrance, pro-fragrance, flavor, malodor counteractive agent, vitamin or derivative thereof, anti-inflammatory agent, fungicide, anesthetic, analgesic, antimicrobial active, anti-viral agent, anti-infectious agent, anti-acne agent, skin lightening agent, insect repellent, animal repellent, vermin repellent, emollient, skin moisturizing agent, wrinkle control agent, UV protection agent, fabric softener active, hard surface cleaning active, skin or hair conditioning agent, flame retardant, antistatic agent, taste modulator, cell, probiotic, antioxidant, self-tanning agent, dihydroxyacetone, cooler, sensate, malodor reactive material, cosmetic active, and combinations thereof. 
     
     
         10 . The microcapsule composition of  claim 9 , wherein the external hydrophilic solvent is water, ethanol, propanol, dipropylene glycol, propylene glycol, glycerin, diethyl phthalate, or a combination thereof. 
     
     
         11 . The microcapsule composition of  claim 9 , wherein the active material is a fragrance having a weighted Hansen solubility parameter of 15 to 20, a Hansen polarizability of 5 or less, and a Hansen h-bonding value of 10 or less. 
     
     
         12 . The microcapsule composition of  claim 9 , wherein the active material is a fragrance having an average vapor concentration at 25° C. of 500 μg/L or more and present at a level of 0.005 to 30% by weight of the microcapsule composition. 
     
     
         13 . The microcapsule composition of  claim 9 , wherein the fragrance contains two or more fragrance ingredients, 50 weight % or more of the fragrance ingredients have a water solubility of 100 ppm or less, 50 weight % or less of the fragrance ingredients have a vapor concentration of 100 μg/L or less, and 30 weight % or less of the fragrance ingredients have a CLogP of 3 or less. 
     
     
         14 . The microcapsule composition of  claim 9 , wherein the Euclidian difference in solubility parameter between the fragrance and the hydrophilic core solvent is less than the Euclidian difference between the fragrance and the hydrophobic core solvent. 
     
     
         15 . The microcapsule composition of  claim 9 , wherein the Euclidian difference in solubility parameter between the fragrance and the hydrophobic core solvent is less than 5. 
     
     
         16 . The microcapsule composition of  claim 9 , further comprising a deposition aid selected from the group consisting of polyquaternium-4, polyquaternium-5, polyquaternium-6, polyquaternium-7, polyquaternium-10, polyquaternium-16, polyquaternium-22, polyquaternium-24, polyquaternium-28, polyquaternium-39, polyquaternium-44, polyquaternium-46, polyquaternium-47, polyquaternium-53, polyquaternium-55, polyquaternium-67, polyquaternium-68, polyquaternium-69, polyquaternium-73, polyquaternium-74, polyquaternium-77, polyquaternium-78, polyquaternium-79, polyquaternium-80, polyquaternium-81, polyquaternium-82, polyquaternium-86, polyquaternium-88, polyquaternium-101, polyvinylamine, polyethyleneimine, polyvinylamine and vinylformamide copolymer, polymer comprising units derived from polyethylene glycol and terephthalate, hydroxypropylcellulose, a polysaccharide, and combinations thereof. 
     
     
         17 . A method of preparing a microcapsule composition of  claim 9 , the method comprising the steps of:
 (a) providing a microcapsule that has a microcapsule core and a microcapsule wall encapsulating the microcapsule core, in which the microcapsule core contains a hydrophobic core solvent and a hydrophilic core solvent, and the microcapsule wall is formed of an encapsulating polymer and permeable to the hydrophilic core solvent;   (b) providing a continuous phase that has an external hydrophilic solvent and an active material;   (c) mixing the microcapsule and the continuous phase to obtain a microcapsule dispersion; and   (d) aging the microcapsule dispersion to obtain the microcapsule composition.   
     
     
         18 . A consumer product comprising the microcapsule composition of  claim 9 , wherein the consumer product is selected from the group consisting of: a baby care product, a diaper rash cream or balm, a baby powder, a diaper, a bib, a baby wipe, a cosmetic preparation, a powder foundation, a liquid foundation, an eye shadow, a lipstick or lip balm, a home care product, an all-purpose cleaner, a bathroom cleaner, a floor cleaner, a window cleaner, a plastics polish, a bleach, a toilet cleaner, a toilet rimblock, a bath tissue, a paper towel, a disposable wipe, liquid air freshener, air freshener spray, a spray dispenser product, an incense stick, a rug deodorizer, a candle, a room deodorizer, a liquid dish detergent, an automatic dish detergent, a powder dish detergent, a leather detergent, a tablet dish detergent, a paste dish detergent, a unit dose tablet or capsule, a flavor, a beverage flavor, a diary flavor, a fruit flavor, a miscellaneous flavor, a sweet goods flavor, a tobacco flavor, a toothpaste flavor, a chewing gum, a breath freshener, an orally dissolvable strips, a chewable candy, a hard candy, an oral care product, a tooth paste, a toothbrush, a dental floss, an oral rinse, an tooth whitener, a denture adhesive, a health care device, a tampon, a feminine napkin, an anti-inflammatory balm, an anti-inflammatory ointment, an anti-inflammatory spray, a disinfectant, a personal care product, a soap, a bar soap, a liquid soap, a bath fragrance, a body wash, a non-aerosol body spray, a body milk, a cleanser, a body cream, a hand sanitizer, a hand wash, a functional product base, a sunscreen lotion, a sunscreen spray, a deodorant, an anti-perspirant, an roll-on product, an aerosol product, a natural spray product, a wax-based deodorant, a glycol type deodorant, a soap type deodorant, a facial lotion, a body lotion, a hand lotion, a miscellaneous lotion, a body powder, a shave cream, a shave gel, a shave butter, a bath soak, a shower gel, an exfoliating scrub, a foot cream, a facial tissue, a cleansing wipe, a talc product, a hair care product, a hair care with ammonia, a shampoo, a hair conditioner, a hair rinse, a hair refresher, a hair fixative or styling aid, a hair bleach, a hair dye or colorant, a fabric care product, a fabric softener, a liquid fabric softener, a fabric softener sheet, a drier sheet, a fabric refresher, an ironing water, a detergent, a laundry detergent, a liquid laundry detergent, a powder laundry detergent, a tablet laundry detergent, a laundry detergent bar, a laundry detergent cream, a hand wash laundry detergent, a scent booster, a fragrance, a cologne, compounds, an encapsulated fragrance, a fine fragrance, a men's fine fragrance, a women's fine fragrance, a perfume, a solid perfume, an Eau De Toilette product, a natural spray product, a perfume spray product, an insect repellent product, and a wildlife scent. 
     
     
         19 . The consumer product of  claim 18 , wherein the consumer product is an aerosol product or natural spray product, each of which contains 0.01 to 50% of the microcapsule composition of  claim 9 . 
     
     
         20 . The consumer product of  claim 18 , wherein the consumer product is a perfume spray product containing 0.01 to 40% of the microcapsule composition, 0.01 to 40% of a fragrance as the active material, at least 60% of ethyl alcohol, 0 to 30% of a suspending polymer, and 0 to 30% of an emollient. 
     
     
         21 . The consumer product of  claim 20 , wherein the suspending agent is polyacrylate crosspolymer-6, acrylates/C10-C30 alkyl acrylate crosspolymer, or a combination thereof, and the emollient is trilsononanoin, ethylhexyl isononanoate, cyclopentasiloxane, or a combination thereof. 
     
     
         22 . The consumer product of  claim 18 , wherein the consumer product is an insect repellent containing 2 to 95% of N,N-Diethyl-meta-toluamide and 1 to 30% of the microcapsule composition.