Microcapsules, their preparation and use

1. A microcapsule comprising:

(A) in a range from 50 to 95 parts by weight, lipophilic core material which has a solid/liquid phase transition in a temperature range from −20 to 120° C.;

(B) in a range from 4 to 50 parts by weight, capsule wall; and

(C) in a range from 0.01 to 10 parts by weight, at least one colored or color-imparting substance selected from the group consisting of an oil-soluble dye and an oil-soluble brightener,

wherein data in parts by weight are based on total weight of the microcapsule in question, and wherein

the capsule wall (B) is a (co)polymer comprising, in reacted form:

30 to 100% by weight of at least one monomer (monomer I), selected from the group consisting of acrylic acid, methacrylic acid, maleic acid, and a C 1 -C 24 -alkyl ester of (meth)acrylic acid;

0 to 70% by weight at least one bi- or polyfunctional monomer (monomer II), which is or are insoluble or sparingly soluble in water; and

0 to 40% by weight at least one other monomer (monomer III) which is at least one monomer selected from the group consisting of vinyl acetate, vinyl propionate, vinylpyridine, styrene, α-methylstyrene, itaconic acid, 2-hydroxyethyl acrylate, methacrylate, acrylamido-2-methylpropanesulfonic acid, methacrylamide, N-vinylpyrrolidone, N-methylolacrylamide, N-methylolmethacrylamide, N,N-dimethyl-aminoethyl methacrylate and diethylaminoethyl methacrylate,

wherein data in % by weight are based on total weight of the capsule wall (B).

2. The microcapsule according to claim 1 , having an average diameter in a range from 0.5 to 100 μm (number-average), determined by light scattering.

3. The microcapsule according to claim 1 , wherein the capsule wall (B) is a copolymer, comprising, in reacted form:

30 to 90% by weight of at least one monomer I;

10 to 70% by weight of at least one monomer II; and

0 to 30% by weight of at least one monomer III.

4. The microcapsule according to claim 1 , wherein monomer II is selected from a mixture of divinyl and polyvinyl monomers, wherein the fraction of the polyvinyl monomers is 2 to 90% by weight, based on the monomers in monomer II.

5. The microcapsule according to claim 1 , wherein the capsule wall (B) comprises, in reacted form:

at least two different monomers I;

optionally, at least one monomer; and

optionally, at least one monomer III.

6. The method of producing the microcapsules according to claim 1 , comprising polymerizing the monomers I, II, and III in the presence of at least one protective colloid.

7. A method of finishing areal substrates-the method comprising coating, impregnating, spraying, printing, or slop-padding an areal substrate with at least one microcapsule according to claim 1 , or incorporating at least one microcapsule according to claim 1 into fibers of the areal substrate.

8. An areal substrate finished with microcapsules according to claim 1 .

9. The substrate according to claim 8 , wherein it is selected from fibrous substrates and building materials.

10. A method of producing a microcapsule according to claim 1 , which comprises (co)polymerizing, in the presence of

(A) in a range from 50 to 95 parts by weight, lipophilic core material which has a solid/liquid phase transition in a temperature range from −20 to 120° C., and

(C) in a range from 0.01 to 10 parts by weight, at least one colored or color-imparting substance selected from the group consisting of an oil-soluble dye and oil-soluble brightener,

in a range from 4 to 50 parts by weight of a monomer or a mixture of monomers:

30 to 100% by weight of at least one monomer (monomer I), selected from the group consisting of acrylic acid, methacrylic acid, maleic acid, and a C 1 -C 24 -alkyl ester of (meth)acrylic acid;

0 to 70% by weight of at least one bi- or polyfunctional monomer (monomer II), which is or are insoluble or sparingly soluble in water; and

0 to 40% by weight of at least one other monomer (monomer III),

wherein data in % by weight are based on total weight of the monomers I, II, and III,

and data in parts by weight are based on a total weight of finished microcapsules.

11. The method according to claim 10 , wherein a (co)polymerization temperature is above a temperature at which lipophilic core material (A) has its solid/liquid phase transition.

12. An aqueous formulation comprising microcapsules according to claim 1 .

13. The aqueous formulation according to claim 12 , further comprising at least one binder.