Perfume microcapsules and related film and detergent compositions
Perfume microcapsule-containing films, related solutions, and containers including the films (e.g. detergent packets) are disclosed, together with their methods of preparation and use.
1. A film having an average thickness in a range of about 5 μm to about 200 μm, and comprising a mixture of a water-soluble polymer, one or more plasticizers, and a plurality of fragrance-containing aminoplast resin microcapsules comprising a median (d50) particle size of at least about 12 μm and a shell comprising 75 to 100% by weight of an aminoplast resin that comprises 50 to 90% by weight of a terpolymer and 10-50% by weight of a polymeric stabilizer, wherein the terpolymer consists of:
(a) 20 to 40% by weight of moieties derived from at least one triamine,
(b) 25 to 60% by weight of moieties derived from at least one diamine, optionally urea; and
(c) 19-35% by weight of moieties selected from the group consisting of alkylene and alkylenoxy moieties having 1 to 6 methylene units.
2. The film of claim 1 , wherein the film average thickness is in a range of about 20 μm to about 100 μm.
3. The film of claim 1 , wherein the water-soluble polymer comprises a polyvinyl alcohol.
4. The film of claim 3 , wherein the polyvinyl alcohol includes an anionic functional group.
5. The film of claim 1 , wherein the plasticizer comprises a polyol.
6. The film of claim 5 , wherein the plasticizer is selected from the group consisting of glycerin, diglycerin, sorbitol, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, polyethylene glycols having a molecular weight up to 400, neopentyl glycol, trimethylolpropane, water, and combinations thereof.
7. The film of claim 1 , wherein the plasticizer is present in an amount in a range of about 10 wt. % to about 45 wt. % by weight of the film.
8. The film of claim 1 , wherein the film further comprises a microcapsule dispersing aid selected from polysaccharides, pectin, alginate, arabinogalactan, carrageenan, gellan gum, xanthan gum, guar gum, acrylates/acrylic polymers, starches, water-swellable clays, acrylate/aminoacrylate copolymers, maltodextrin, natural gums, alginate esters, gelatine, protein hydrolysates and their quaternized forms, synthetic polymers and copolymers, poly(vinyl pyrrolidone-co-vinyl acetate), poly(vinyl alcohol-co-vinyl acetate), poly(maleic acid), poly(alkyleneoxide), poly(vinylmethylether), poly(vinylether-co-maleic anhydride), poly-(ethyleneimine), poly((meth)acrylamide), poly(alkyleneoxide-co-dimethylsiloxane), poly(amino dimethylsiloxane), and combinations thereof.
9. The film of claim 1 , wherein the plurality of microcapsules are present in an amount in a range of 3 wt. % to 50 wt. % of the film.
10. The film of claim 1 , wherein the microcapsules are characterized by a d50 particle size in a range of 12 μm to 50 μm.
11. The film of claim 1 , wherein the microcapsules are characterized by a d50 particle size of at least 12 μm.
12. The film of claim 11 , wherein the microcapsules are characterized by a d50 particle size of at least 16 μm.
13. The film of claim 1 , wherein the microcapsules are characterized by a d50 particle size less than 33% of the film average thickness.
14. The film of claim 1 , wherein the microcapsules are characterized by a d90 particle size less than 33% of the film average thickness.
15. The film of claim 1 , wherein the microcapsules comprise multilayered shells.
16. The film of claim 1 , wherein the microcapsule wall thickness is in a range of about 50 nm to about 500 nm.
17. The film of claim 1 , wherein the average ratio of the microcapsule shell weight, expressed in % by weight of the total microcapsule weight to the sum of the shell material plus fragrance, to the microcapsule capsule diameter, expressed in microns, is about 0.7 microns −1 or less.
18. The film of claim 1 , wherein the fragrance in the microcapsules comprises 60 wt. % to 95 wt. % of the microcapsules, based on the total weight of the microcapsules.
19. The film of claim 1 , wherein the terpolymer consists of moieties derived from melamine, urea, and formaldehyde.
20. The film of claim 1 , wherein the aminoplast resin microcapsule is formed by a process comprising:
(a) adding and dissolving polymer stabilizer in water under shear mixing;
(b) adjusting the temperature and pH of the solution, then adding alkylolated triamine or triamine pre-condensate, diamine or diamine precondensate, and perfume;
(c) emulsifying the system under shear mixing;
(d) warming the emulsified system to an elevated temperature above the temperature of step (b), then holding the system at the elevated temperature for at least one hour;
(e) adding ethylene urea as formaldehyde scavenger while the slurry is still at an elevated temperature above the temperature of step (b);
(f) cooling the system; and
(g) optionally adding a suspending agent then adding NaOH.
21. The film of claim 20 , wherein,
in step (b) the temperature is adjusted to 35±2° C., the pH to 4.6±2; and
in step (d) the emulsified system is warmed to 88° C.±1° C. over a period of 75 min, then the reaction system is held at 88° C.±2° C. for 2 h 15 min.
22. The film of claim 1 , wherein the film is a cast film.
23. The film of claim 22 , wherein the cast film is also a thermoformed film.
24. A container comprising the film of claim 1 , disposed as a wall of the container.
25. The container of claim 24 , wherein the film has a surface area in a range of 25 cm 2 to 75 cm 2 .
26. The container of claim 24 , wherein the container has an interior volume of 35 ml or less.
27. The container of claim 24 , wherein the container contains 35 ml or less of detergent.
28. The container of claim 27 , wherein the detergent is a liquid detergent having a water content of 20 wt. % or less based on the total weight of the liquid detergent.
29. The container of claim 24 , wherein the microcapsule content in the film is in a range of 0.03 g to 0.5 g.
30. A method of making a fragrance-containing water-soluble film according to claim 1 , comprising: forming a mixed aqueous solution comprising a polymer resin and a plasticizer, optionally with heating; degassing the mixture; adding fragrance-containing microcapsules to the degassed solution to form a suspension; mixing the suspension; casting the suspension onto a surface; and allowing the suspension to substantially dry.
31. The method of claim 30 , wherein the suspension comprising the fragrance-containing microcapsules, dissolved polymer, and plasticizer, is maintained at a temperature of 65° C. before casting.
32. The method of claim 30 , wherein the mixing of the suspension comprising the fragrance-containing microcapsules, polymer resin, and plasticizer comprises stirring at 300 RPM or less.
33. The method of claim 30 , wherein the mixing of the suspension comprising the fragrance-containing microcapsules, polymer resin, and plasticizer comprises passing the suspension through an inline mixer.