Aqueous mini-emulsions which are stable in storage and based on cholesteric mixtures
A storage-stable aqueous miniemulsion whose disperse phase comprises a cholesteric mixture is prepared and is used for coating and printing on suitable substrates.
1. A storage-stable aqueous miniemulsion, comprising:
a disperse phase which comprises the following components:
a1) an achiral nematic difunctionally polymerizable monomer,
a2) two achiral nematic monofunctionally polymerizable monomers,
a3) an achiral nematic difunctionally polymerizable monomer,
b) an achiral nematic nonpolymerizable compound and
c) a chiral di- or monofunctionally polymerizable monomer,
the nematic components a1), a2) and b) having the same mesogenic group and a3) having a mesogenic group differing from this.
2. A miniemulsion as claimed in claim 1 , wherein the mesogenic group of the nematic components a1), a2) and b) comprises a substituted 1,4-dioxybenzene building block.
3. A miniemulsion as claimed in claim 2 , wherein the disperse phase comprises the following components:
4. A miniemulsion as claimed in claim 1 , which comprises not more than 5% by weight, based on the total weight of the disperse phase, of assistants.
5. A miniemulsion as claimed in claim 1 , having a volume average droplet size of the disperse phase of from 100 to 600 nm.
6. A process for the preparation of a storage-stable aqueous miniemulsion as claimed in claim 1 , wherein all constituents of the disperse phase are first emulsified in a conventional manner in water and the conventional emulsion obtainable thereby is then treated with a high-pressure homogemzer.
7. A process as claimed in claim 6 , wherein the mixture is emulsified at from 50 to 2000 bar.
8. A method, which comprises
coating or printing on flexible and rigid substrates the storage stable aqueous mini-emulsion as claimed in claim 1 .
9. A process for coating or printing on flexible and rigid substrates, wherein a storage-stable aqueous miniemulsion as claimed in claim 1 is applied to the substrate, optionally oriented, optionally dried and polymerized.
10. An article provided with a coating or a print comprising a storage-stable aqueous miniemulsion as claimed in claim 1 .
11. A two-component system containing two storage-stable aqueous miniemulsions as claimed in claim 1 , wherein the concentrations of the components c) are different in each case with otherwise identical composition.
12. A two-component system as claimed in claim 11 , the concentrations of component c) being chosen in each case so that the first emulsion gives an LC effect coating having a reflection wavelength of from 300 to 400 nm and the second emulsion gives an LC effect coating having a reflection wavelength of from 600 to 800 nm.
13. A method for producing an having a LC effect coating comprising:
applying the two-component system as claimed in claim 11 to said article;
optionally orienting said miniemulsions, optionally drying and polymerizing said miniemulsions.
14. A process for producing an LC effect printed article, which comprises:
applying the two-component system as claimed in 11 to said article with a printer;
optionally orienting said miniemulsions, optionally drying and polymerizina said miniemulsions.