Microcapsules and macrocapsules having low remnant free formaldehyde microcapsules and methods of making same
A microcapsule or microcapsule having a polymer wall comprising a melamine formaldehyde reacted with a crosslinking agent to form a unit cell according to a general formula (II) and/or the polymer wall has a FT-IR Spectrum as shown in FIG. 4. The crosslinking agent is a mixture of a reaction product of a cyclic urea (U) and a multifunctional aldehyde (A), and at least one crosslinker selected from the following group: a reaction products of (i) an aminotriazine and at least one aldehyde selected from the group consisting of aliphatic monoaldehydes and multifunctional aliphatic aldehydes, (ii) urea and/or cyclic ureas and formaldehyde, or (iii) phenols and aliphatic monoaldehydes, or from alkoxycarbonylaminotriazines, or multifunctional isocyanates, epoxides, aziridines, and carbodiimides.
1. A capsule having a polymer wall comprising a melamine formaldehyde reacted with a crosslinking agent to form a unit cell according to the formula:
wherein R is H or CH 3 .
2. The capsule of claim 1 , wherein the crosslinking agent comprises
(a) a reaction product of a cyclic urea (U) and a multifunctional aldehyde (A), and
(b) at least one crosslinker selected from the group consisting of
(b 1) reaction products of an aminotriazine and at least one aldehyde selected from the group consisting of aliphatic monoaldehydes and multifunctional aliphatic aldehydes having the structure Y(CHO) n , where Y is an n-functional aliphatic residue, and n is greater than 1, where U is not dihydroxyethylene urea if the crosslinker (b) is (b1),
(b2) reaction products of urea and/or cyclic ureas and formaldehyde,
(b3) alkoxycarbonylaminotriazines,
(b4) multifunctional isocyanates, optionally partially or completely blocked,
(b5) reaction products of phenols and aliphatic monoaldehydes,
(b6) multifunctional epoxides,
(b7) multifunctional aziridines, and
(b8) multifunctional carbodiimides,
wherein any of the crosslinkers (a) and (b) which have hydroxyl groups are optionally etherified with one or more linear, branched, or cyclic aliphatic alcohols.
3. The capsule of claim 1 , wherein the polymer wall has a thickness of about 0.2 μm to about 0.6 μm.
4. The capsule of claim 1 , wherein the polymer wall has less than 60 ppm initial free formaldehyde.
5. The capsule of claim 1 , wherein the polymer wall has less than 40 ppm initial free formaldehyde.
6. The capsule of claim 1 , wherein the polymer wall has less than 20 ppm initial free formaldehyde.
7. The capsule of claim 1 , wherein the polymer wall has less than 10 ppm initial free formaldehyde.
8. The capsule of claim 7 , wherein the polymer wall has less than 20 ppm of free formaldehyde during four weeks after formation.
9. The capsule of claim 7 , wherein the polymer wall has less than 40 ppm of free formaldehyde during four weeks after formation.
10. The capsule of claim 1 , wherein the polymer wall has free formaldehyde below 40 ppm from day 1 to week 4.
11. The capsule of claim 1 , wherein the polymer wall has free formaldehyde below 20 ppm from day 1 to week 4.
12. The capsule of claim 1 , wherein the capsules are microcapsules or macrocapsules.
13. A capsule comprising a polymer wall comprising a melamine formaldehyde reacted with a crosslinking agent, wherein the polymer wall has a FT-IR Spectrum of FIG. 4 .
14. The capsule of claim 13 , wherein the capsules are microcapsules or macrocapsules.
15. The capsule of claim 13 , wherein the polymer wall has less than 60 ppm initial free formaldehyde.
16. The capsule of claim 13 , wherein the polymer wall has less than 40 ppm initial free formaldehyde.
17. The capsule of claim 13 , wherein the polymer wall has less than 20 ppm initial free formaldehyde.
18. The capsule of claim 13 , wherein the polymer wall has less than 10 ppm initial free formaldehyde and less than 20 ppm of free formaldehyde during four weeks after formation.
19. The capsule of claim 13 , wherein the polymer wall has less than 10 ppm initial free formaldehyde and less than 40 ppm of free formaldehyde during four weeks after formation.
20. The capsule of claim 13 , wherein the polymer wall has free formaldehyde below 40 ppm from day 1 to week 4.
21. The capsule of claim 13 , wherein the polymer wall has free formaldehyde below 20 ppm from day 1 to week 4.
22. A capsule having a polymer wall comprising a melamine formaldehyde reacted with a crosslinking agent that comprises
(a) a reaction product of a cyclic urea (U) and a multifunctional aldehyde (A), and
(b) at least one crosslinker selected from the group consisting of
(b 1) reaction products of an aminotriazine and at least one aldehyde selected from the group consisting of aliphatic monoaldehydes and multifunctional aliphatic aldehydes having the structure Y(CHO) n , where Y is an n-functional aliphatic residue, and n is greater than 1, where U is not dihydroxyethylene urea if the crosslinker (b) is (b 1),
(b2) reaction products of urea and/or cyclic ureas and formaldehyde,
(b3) alkoxycarbonylaminotriazines,
(b4) multifunctional isocyanates, optionally partially or completely blocked,
(b5) reaction products of phenols and aliphatic monoaldehydes,
(b6) multifunctional epoxides,
(b7) multifunctional aziridines, and
(b8) multifunctional carbodiimides,
wherein any of the crosslinkers (a) and (b) which have hydroxyl groups are optionally etherified with one or more linear, branched, or cyclic aliphatic alcohols.
23. The capsule of claim 22 , wherein the polymer wall has a thickness of about 0.2 μm to about 0.6 μm.
24. The capsule of claim 22 , wherein the polymer wall has free formaldehyde below 40 ppm from day 1 to week 4.
25. The capsule of claim 22 , wherein the polymer wall has free formaldehyde below 20 ppm from day 1 to week 4.
26. The capsule of claim 22 , wherein the capsules are microcapsules or macrocapsules.
27. The capsule of claim 22 , wherein the polymer wall has less than 10 ppm initial free formaldehyde and less than 20 ppm of free formaldehyde during four weeks after formation.
28. The capsule of claim 22 , wherein the polymer wall has less than 10 ppm initial free formaldehyde and less than 40 ppm of free formaldehyde during four weeks after formation.