WO2008141971A2

WO2008141971A2 - Inverse colloidal crystals

Info

Publication number: WO2008141971A2
Application number: PCT/EP2008/055820
Authority: WO
Inventors: Jian Cao; Guan-Jun Ding; Ramin Djalali
Original assignee: Unilever Plc; Unilever N.V.; Hindustan Unilever Limited
Priority date: 2007-05-18
Filing date: 2008-05-13
Publication date: 2008-11-27
Also published as: JP2010532738A; BRPI0811736A2; WO2008141971A3; CN101743211A; EP2150505A2

Abstract

The present invention relates to novel inverse crystal compounds, novel colourant compositions comprising such inverse crystal compounds, to uses thereof in colouring a substrate and to substrates that are coloured (at least in part) using the colourant compositions.

Description

Inverse Colloidal Crystals

Chromophores are materials that impart a colour. Colours typically are produced by the absorption or emission of light and the loss of photon energy.

Colours may also be produced by structural effects, for example when light is reflected and/or diffracted by highly regular structures having dimensions that match the wavelength of visible light. Such structures can have different colours when viewed from different angles, which effect is known in the art as "structural colour". Examples of colours produced in this way can be found in nature, for example in some butterfly wings, peacock feathers, the hair of a seamouse and semi-precious gemstones such as opals.

Inverse colloidal crystals are known from the prior art, for examples from US 6756115 and US 20050226806. The colouring effect of these inverse colloidal crystals is not so brilliant or strong when applied to a material.

The goal of the present invention was to provide an inverse colloidal crystal, which delivers improved coloring effects when applied onto a material.

Surprisingly is has been found out that the addition of a broad spectrum absorber contrast agent, the properties, especially when applied onto a material, are improved.

The present invention provides an inverse colloidal crystal which comprises (i) a regular array of pores dispersed in a solid continuous phase and (ii) at least one broad spectrum absorber contrast agent and/or at least one precursor of a broad spectrum absorber contrast agent.

The pores of the inverse colloidal crystal do all have similar dimensions. The diameter of the pores of the inverse colloidal crystal can differ (depending on the way of production of the inverse colloidal crystal) up to 15 %. The pores preferably have a diameter between

0.05 and 50 μm, preferably between 0.05 - 40μm, more preferably between 0.05 - 30μm, even more preferred 0.1 - 30μm, especially preferred 0.1 - 10μm, most preferred 0.1 - 5μm.

The pores size is measured by Scanning Electron Microscopy (SEM).

The broad spectrum absorber contrast agent can be incorporated into the solid continuous phase as well as on the surface of the solid continuous phase as well as both.

Therefore a further embodiment of the present invention relates to an inverse colloidal, wherein the broad spectrum absorber contrast agent is incorporated into the solid continuous phase.

Therefore a further embodiment of the present invention relates to an inverse colloidal crystal, wherein the broad spectrum absorber contrast agent is on the surface of the solid continuous phase.

Therefore a further embodiment of the present invention relates to an inverse colloidal, wherein the broad spectrum absorber contrast agent is incorporated into the solid continuous phase and on the surface of the solid continuous phase.

Thus, the array of pores forms a dispersed phase between the solid continuous phase.

By the term "broad spectrum absorber contrast agent" we mean a compound that

(a) absorbs substantially all light having a wavelength in a range that corresponds to the wavelength of visible light, and

(b) eliminates diffuse light.

Additionally, because of the way of the production of the inverse colloidal crystal of the present invention the broad spectrum absorber contrast agent should be able to bear the reaction condition of the production procedure. Depending on what kind of conditions are chosen the broad spectrum absorber contrast agent should be suitable to bear temperature up to 1000^°C and/or be able to bear the presence of solvent.

In the light of the present invention the term "broad spectrum absorber contrast agent" also comprises a mixture of compounds wherein that mixture has the same absorption property as a single broad spectrum absorber contrast agent. Such a mixture still must eliminate diffuse light. That means that each single compound of such a mixture only absorbs the light in a well defined area and only the combination of these compounds provide a broad spectrum absorber.

In the following the term "broad spectrum absorber contrast agent" always stands for either a single compound or a mixture of compounds.

It is also possible to use a precursor of a broad spectrum absorber contrast agent. That precursor is converted into the broad spectrum absorber contrast agent by using a form of energy (such as light (UV), heat, etc). That means that the precursor can be transformed during the production of the inverse colloidal crystal or after its production.

Suitable broad spectrum absorber contrast agents include absorbing elements such as silver and pigments such as carbon black (for example the carbon black product line from Degussa, such as Purex^® LS 35 and Corax^® N 1 15) and iron oxide black as well as other black metal oxides, such as silver oxide.

Suitable precursors for the present invention are metal salts, preferably hydrophilic metal salts, such as nitrates or halogenides. Preferred halogenides are F, Cl or I, whereas Cl is the most preferred halogenide.

The metals are for example alkaline metals, alkaline earth metals, noble metals, rare earth metals or transition metals. Suitable metals are for example K, Ca, Sr, Ba, Zn, Pb, Fe, Ni, Ce, Co, Cr, Cu, Mn, Sn, Al, Ag, Mg, Au and Cd. Preferred are Ca. Mg, Al, Ag and Zn.

Very suitable metal salts are Ag nitrate, Ag halogenide, Fe nitrate and Fe halogenide (especially FeCI₂ and FeCI₃).

As an example AgNO₃ is converted into colloidal silver. It is also possible to use more than one precursor.

As a further example FeCI₂ as well as FeCI₃ are converted into black iron oxide and/or iron hydroxide. - A -

Additionally it is also possible to use one or more precursor and another compound which form then a mixture, which has the required broad spectrum absorber contrast agent property. In the following the term "precursor of a broad spectrum absorber contrast agent" always stands for either a single compound or a mixture of compounds.

By this we mean that, as a pure material, the broad spectrum absorber contrast agent absorbs sufficient light so as to appear black or darkly coloured (for example dark blue or dark purple) to the human eye. For example, a broad spectrum absorber contrast agent absorbs most (particularly all) light having a wavelength in a range of from 380 to 780 nm. More specifically, the broad spectrum absorber contrast agent absorbs at least 90% (preferably at least 95%, more preferably 100%) of light having a wavelength in a range of from 380 to 780 nm.

The term "broad spectrum absorber contrast agent" is not intended to encompass those agents that do not absorb substantially all light having a wavelength in a range that corresponds to the wavelength of visible light (and, therefore, that, as a pure material, do not appear black or darkly coloured to the human eye). This term also is not intended to encompass single fluorescent agents, such as single fluorescent dyes or single pigments. But it is possible to encapsulate for example a mixture of various pigments, which have different absorption maxima and wherein the addition of these maxima has a broad spectrum absorber property.

The broad spectrum absorber contrast agent can be organic, that means that it comprises atoms selected from carbon, hydrogen, oxygen, nitrogen and/or sulfur only.

The broad spectrum absorber contrast agent can be inorganic, that means that it comprises metal atoms.

Inorganic broad spectrum absorber contrast agents are preferred.

In the compositions of the present invention, the broad spectrum absorber contrast agent typically absorbs substantially all of the light that is diffused by the colloidal inverse crystal and that has a wavelength in a range that corresponds to the wavelength of visible light. Contrast agents that are not broad spectrum absorbers as defined herein do not absorb substantially all of the diffused light. The unabsorbed, diffused light dilutes the structural colour effect caused by the direct reflection and/or diffraction of visible light by the inverse crystal. The broad spectrum absorber contrast agent may, for example, be a dye or a pigment or a mixture of dyes or a mixture of pigments and dyes as well as a mixture of pigments and dyes, which fulfils the requirements for the broad spectrum absorber contrast agent as defined in the present patent application. A "dye" generally has an affinity to the substrate to which it is applied and generally is in the form of a solution or an oil. A

"pigment" generally does not have an affinity to the substrate to which it is applied and is in the form of a solid. As the skilled person would appreciate, the exact physical form of the contrast agent is not essential to the present invention and the physical form may change upon application of the colourant composition to a suitable substrate.

Typically, the inverse colloidal crystal reflects and/or diffracts light having a wavelength in a range that corresponds to the wavelength of visible light and the broad spectrum absorber contrast agent absorbs substantially all light having a wavelength in a range that corresponds to the wavelength of visible light (for example that is diffused by the inverse colloidal crystal).

In this aspect, the broad spectrum absorber contrast agent and/or a precursor of a broad spectrum absorber contrast agent may be located in the solid continuous phase and/or in the pores of the inverse colloidal crystal. According to a particular aspect of the present invention, there is provided a colourant composition comprising (i) an inverse colloidal crystal comprising a regular array of pores dispersed in a solid continuous phase and (ii) at least one broad spectrum absorber contrast agent and/or at least one precursor of a broad spectrum absorber contrast agent located in the solid continuous phase. The broad spectrum absorber contrast agent is as hereinbefore defined. Preferably the broad spectrum absorber contrast agent and/or the precursor of a broad spectrum absorber contrast agent are inorganic.

The solid continuous phase may comprise any suitable solid, for example one or more of silica, metal oxides, metals, metal chalcogenides, metal pnictides and organic polymers.

The pores may comprise any suitable gas and/or liquid and are arranged in the inverse colloidal crystal so as to have a substantially regular or constant spacing therebetween. However, as the skilled person would appreciate, some defects in the inverse colloidal crystal are unavoidable. The inverse colloidal crystal can comprise up to 5 weight-% (wt-%), based on the total weight of the inverse colloidal crystal, of at least one broad spectrum absorber contrast agent and/or at least one precursor of a broad spectrum absorber contrast agent. Usually the inverse colloidal crystal comprises 0.0001 to 3 wt-%, preferably 0.0001 to 1 wt-%, based on the total weight of the inverse colloidal crystal, of at least one broad spectrum absorber contrast agent and/or at least one precursor of a broad spectrum absorber contrast agent.

Therefore a further embodiment of the present invention relates to an inverse colloidal crystal comprises 0.0001 to 3 wt-%, preferably 0.0001 to 1 wt-%, based on the total weight of the inverse colloidal crystal, of at least one broad spectrum absorber contrast agent and/or at least one precursor of a broad spectrum absorber contrast agent.

The inverse crystal according to the present invention comprises up to 99.9999 wt-%, based on the total weight of the inverse colloidal crystal, of the solid continuous phase.

Therefore a further embodiment of the present invention relates to an inverse colloidal crystal comprising up 99.9999 wt-%, based on the total weight of the inverse colloidal crystal, of the solid continuous phase.

Preferably the inverse colloidal crystal comprises 97 to 99.9999 wt-%, preferably 99 to 99.9999 wt-%, based on the total weight of the inverse colloidal crystal, of the solid continuous phase.

Therefore a further embodiment of the present invention relates to an inverse colloidal crystal comprising up to 99.9999 wt-%, based on the total weight of the inverse colloidal crystal, of the solid continuous phase, and up to 3 wt-%, based on the total weight of the inverse colloidal crystal, of at least one broad spectrum absorber contrast agent and/or at least one precursor of a broad spectrum absorber contrast agent.

A preferred embodiment of the present invention relates to an inverse colloidal crystal comprising 97 to 99.9999 wt-%, preferably 99 to 99.9999 wt-%, based on the total weight of the inverse colloidal crystals, of the solid continuous phase, and 0.0001 to 3 wt-%, preferably 0.0001 to 1 wt-%, based on the total weight of the inverse colloidal crystal, of at least one broad spectrum absorber contrast agent and/or at least one precursor of a broad spectrum absorber contrast agent.

A further embodiment of the present invention relates to an inverse colloidal crystal comprising up 99.9999 wt-%, based on the total weight of the inverse colloidal crystal, of silica, metal oxides, metals, metal chalcogenides, metal pnictides and/or organic polymers, and up to 3 wt-%, based on the total weight of the inverse colloidal crystal, of at least one broad spectrum absorber contrast agent and/or at least one precursor of a broad spectrum absorber contrast agent.

A preferred embodiment of the present invention relates to an inverse colloidal crystal comprising

97 to 99.9999 wt-%, preferably 99 to 99.9999 wt-%, based on the total weight of the inverse colloidal crystal, of silica, metal oxides, metals, metal chalcogenides, metal pnictides and/or organic polymers, and

0.0001 to 3 wt-%, preferably 0.0001 to 1 wt-%, based on the total weight of the inverse colloidal crystal, of at least one broad spectrum absorber contrast agent and/or at least one precursor of a broad spectrum absorber contrast agent.

A more preferred embodiment of the present invention relates to an inverse colloidal crystal comprising up 99.9999 wt-%, based on the total weight of the inverse colloidal crystals, of silica, metal oxides, metals, metal chalcogenides, metal pnictides and/or organic polymers, and up to 3 wt-%, based on the total weight of the inverse colloidal crystals, of at least one broad spectrum absorber contrast agent and/or at least one precursor of a broad spectrum absorber contrast agent chosen from the group consisting of carbon black, black iron oxide, iron hydroxide, silver oxide black K, Ca, Sr, Ba, Zn, Pb, Fe, Ni, Ce,

Co, Cr, Cu, Mn, Sn, Al, Ag, Mg, Au, Cd, Ag nitrate, Ag halogenide, Fe nitrate and Fe halogenide.

A very preferred embodiment of the present invention relates to an inverse colloidal crystal comprising 97 to 99.9999 wt-%, preferably 99 to 99.9999 wt-%, based on the total weight of the inverse colloidal crystal of silica, metal oxides, metals, metal chalcogenides, metal pnictides and/or organic polymers, and

0.0001 to 3 wt-%, preferably 0.0001 to 1 wt-%, based on the total weight of the inverse colloidal crystal, of at least one broad spectrum absorber contrast agent and/or at least one precursor of a broad spectrum absorber contrast agent chosen from the group consisting of carbon black, black iron oxide, iron hydroxide, silver oxide black, K, Ca, Sr, Ba, Zn, Pb, Fe, Ni, Ce, Co, Cr, Cu, Mn, Sn, Al, Ag, Mg, Au, Cd, Ag nitrate, Ag halogenide, Fe nitrate and Fe halogenide.

Processes for making inverse colloidal crystals are known. For example, an inverse colloidal crystal may be formed by conducting the steps of:

(i) providing a colloidal crystal formed of a regular array of monodisperse particles; (ii) adding a material so as to introduce a solid into the interstices between the monodisperse particles in the colloidal crystal and to form a solid continuous phase; and (iii) removing the monodisperse particles so as to form a regular array of pores in the solid continuous phase.

To obtain inverse colloidal crystals according to the present invention the known processes have to be amended in the way that a broad spectrum absorber contrast agent and/or a precursor of a broad spectrum absorber contrast agent is part of the process of production either in step (i) or in step (ii) or in both steps.

Therefore a further embodiment of the present invention is a process for the production of an inverse colloidal crystal by conducting the steps of:

(i) providing a colloidal crystal formed of a regular array of monodisperse particles, wherein the colloidal crystal comprises at least one broad spectrum absorber contrast agent and/or at least one precursor of a broad spectrum absorber contrast agent;

(ii) adding a material so as to introduce a solid into the interstices between the monodisperse particles in the colloidal crystal and to form a solid continuous phase; and (iii) removing the monodisperse particles so as to form a regular array of pores in the solid continuous phase. Therefore a further embodiment of the present invention is a process for the production of an inverse colloidal crystal by conducting the steps of:

(ii) adding a material so as to introduce a solid into the interstices between the monodisperse particles in the colloidal crystal and to form a solid continuous phase, wherein the material comprises at least one broad spectrum absorber contrast agent and/or at least one precursor of a broad spectrum absorber contrast agent; and

(iii) removing the monodisperse particles so as to form a regular array of pores in the solid continuous phase.

(i) providing a colloidal crystal formed of a regular array of monodisperse particles; (ii) adding a material so as to introduce a solid into the interstices between the monodisperse particles in the colloidal crystal and to form a solid continuous phase, wherein the material comprises at least one broad spectrum absorber contrast agent and/or at least one precursor of a broad spectrum absorber contrast agent; and (iii) removing the monodisperse particles so as to form a regular array of pores in the solid continuous phase.

The broad spectrum absorber contrast agent and/or the precursor of a broad spectrum absorber contrast agent can be incorporated into the monodisperse particles as well in the material which is used to form the solid continuous phase or both.

By the term "monodisperse particles" we mean particles wherein at least 60% of the particles fall within a specified particle size range. For example, the monodisperse particles preferably have a diameter that deviates less than 10% in root mean square (rms), more preferably that deviates less than 5% in rms diameter, especially preferably even less than 3% in rms diameter. By the term "encapsulated" we mean that the broad spectrum absorber contrast agent and/or at least one precursor of a broad spectrum absorber contrast agent is enclosed or embedded within the monodisperse particles. The broad spectrum absorber contrast agent and/or at least one precursor of a broad spectrum absorber contrast agent is (more or less) evenly distributed in the monodisperse particles. That means that it is not concentrated mainly in one part of the monodisperse particle.

STEP (i): The colloidal crystal comprising no broad spectrum absorber contrast agent and no precursor of a broad spectrum absorber contrast agent can be formed from monodisperse particles.

Such monodisperse particles are commercially available or can be prepared by methods known in the art.

Monodisperse particles made from inorganic materials, such as silica particles, may be prepared as dispersions using sol-gel processes.

For example, monodisperse silica spheres can be prepared following the well-known process by Stober, Fink and Bohn (J. Colloid Interface Sci. 1968, 26,62). The process was later refined by Bogush et al. (J. Non-Crys. Solids 1988, 104, 95). Alternatively, silica particles can be purchased from Blue Helix, Limited or they can be freshly prepared by the process described in US 4,775,520 and US 4,91 1 ,903.

Monodisperse silica spheres may also be produced by hydrolytic polycondensation of tetraalkoxysilanes in an aqueous-ammoniacal medium, a sol of primary particles being produced first of all and then the silica particles obtained being brought to the desired particle size by continuous, controlled addition of tetraalkoxysilane. With this process it is possible to produce monodisperse silica spheres having average particle diameters of between 0.05 and 10 μm with a standard deviation of less than 7%.

Monodisperse particles made from organic polymer particles may be prepared as dispersions using emulsion, dispersion or suspension polymerisation. For example, US 6,800,709 describes the preparation of monodisperse particles with a narrow size distribution by free radical polymerization or copolymerization of hydrophobic monomers in a water-based system in the presence of cyclodextrin. Suitable hydrophobic monomers include styrenics, acrylonitrile, methacrylonitrile, acrylates, methacrylates, methacryl amides, acrylamides, maleimides, vinyl ethers, vinyl esters, monoalkylmaleates, dialkyl maleates, fluorinated acrylates and fluorinated methacrylates.

Monodispersed poly(methylmethacrylate) composites may be prepared following the process described by M. Egen, R. Zentel (Macromol. Chem. Phys. 2004, 205, 1479- 1488) or are commercially available from Duke Scientific Corporation.

It is also possible that a colloidal crystal is formed which comprises at least one broad spectrum absorber contrast agent. In such a case it is possible that the broad spectrum absorber contrast agent is added to the monodisperse particles during the formation of the crystal. So it is possible that the broad spectrum absorber contrast agent and/or the precursor of a broad spectrum absorber contrast agent is located on the surface of monodisperse particles as well as it can be located between the monodisperse particles. But is also possible that the broad spectrum absorber contrast agent is encapsulated in the monodisperse particles.

All combinations of the possible location of the broad spectrum absorber contrast agents and their precursors are possible as well.

When the broad spectrum absorber contrast agent and/or at least one precursor of a broad spectrum absorber contrast agent is encapsulated in the monodisperse particles, the monodisperse particles typically are formed in the presence of the broad spectrum absorber contrast agent and/or at least one precursor of a broad spectrum absorber contrast agent. For example, monodisperse organic polymer particles (such as polystyrene or poly(methylmethacrylate) particles) that encapsulate at least one broad spectrum absorber contrast agent (such as a dye) and/or at least one precursor of a broad spectrum absorber contrast agent may be prepared using surfactant free emulsion polymerisation, as discussed in more detail below.

A broad spectrum absorber contrast agent and/or a precursor of a broad spectrum absorber contrast agent may be encapsulated into the monodisperse particles using

Surfactant Free Emulsion Polymerisation (SFEP) processes, in which the polymerisation is conducted in the presence of an appropriate contrast agent. For example, Zentel et al. (Chemistry of Materials, 12 (8): 2508) describes a process in which monodisperse organic polymer particles are produced in a Surfactant Free Emulsion Polymerisation (SFEP) in the presence of a water soluble dye. The SFEP process typically produces substantially spherical polymer particles of a narrow size distribution and having surface charges that produce electrostatic repulsion so as to prevent aggregation. The SFEP process also is typically conducted in the absence of emulsifiers which, if present, could bond the particles together so as to make the formation of the colloidal crystals (for example by sedimentation or self-assembly methods) difficult.

A water-insoluble broad spectrum absorber contrast agent and/or a precursor of a broad spectrum absorber contrast agent may be encapsulated into the monodisperse particles by emulsifying the monodisperse particles in a suitable oil. In this case, the monodisperse particles may additionally encapsulate an oil.

As the person skilled in the art would appreciate, the monodisperse particles may comprise any suitable broad spectrum absorber contrast agent and/or any precursor of a broad spectrum absorber contrast agent. In one aspect of the invention, the monodisperse particles comprise at least one broad spectrum absorber contrast agent and/or at least one precursor of a broad spectrum absorber contrast agent which are organic.

In another aspect of the invention, the monodisperse particles comprise at least one broad spectrum absorber contrast agent and/or at least one precursor of a broad spectrum absorber contrast agent which inorganic.

Preferably the broad spectrum absorber contrast agents and the precursors of a broad spectrum absorber contrast agent are inorganic.

STEP (ii):

The material that is added to the colloidal crystals in step (ii) may be a solid or it may be a liquid or a gas that can be treated so as to form a solid. The material substantially fills the continuous phase of the colloidal crystals and forms a solid continuous phase around the monodisperse particles. As the skilled person would appreciate, it is not necessary for 100% of the interstices in the colloidal crystals to be filled with the solid. Typically, it is sufficient that at least 25%, preferably at least 50%, more preferably at least 75%, of the interstices are filled with the solid.

The material can comprise at least one broad spectrum absorber contrast agent and/or at least one precursor of a broad spectrum absorber contrast agent. It is preferred that the material comprises at least one broad spectrum absorber contrast agent and/or at least one precursor of a broad spectrum absorber contrast agent.

A preferred material is a silica, metal oxides, metals, metal chalcogenides, metal pnictides and organic polymers solution comprising at least one broad spectrum absorber contrast agent and/or at least one precursor of a broad spectrum absorber contrast agent.

Step (ii) may be conducted using any suitable method, such as by metal-organic chemical vapour deposition, by high-pressure high-temperature processes or by sol-gel processes. For example, silica, metals (such as Ge), metal chalcogenides (such as SnS₂) and metal oxides (such as TiO₂) may be introduced into the interstices by metal-organic chemical vapour deposition (CVD). Metal pnictides (such as InSb) may be introduced to the interstices in a molten state in a high-pressure high-temperature process and metal chalcogenides (such as CdSe and CdS) may be introduced into the interstices using a sol-gel process.

STEP (iii):

In step (iii), the monodisperse particles may be removed from the structure by any suitable method, for example by etching. For example, monodisperse silica particles may be removed from colloidal crystals by adding a hydrogen fluoride solution of an appropriate concentration (provided that the hydrogen fluoride solution does not also substantially dissolve and/or remove the solid continuous phase). Monodisperse poly(methylmethacrylate) particles may be removed from colloidal crystals by adding a suitable organic solvent so as to dissolve the poly(methylmethacrylate) particles. In each case, the solution or solvent containing the monodisperse particles is suitably removed from the solid continuous phase so as to provide the array of pores dispersed in the solid continuous phase.

Heating is another way to remove the monodisperse particles. Depending on the kind of particles the temperature can be between 80^°C up to 1000^°C. The heating can for example take place in an oven. Electromagnetic radiation is another way to remove the monodisperse particles.

The inverse colloidal crystals as described above can be used in colourant compositions.

The colourant compositions of the present invention comprising inverse colloidal crystals as described above may be applied to any suitable substrate to colour at least a region of the substrate.

The colouring composition of the present invention can be used to print on and/or to coat any commonly known substrates.

Suitable substrated for printing and coating include fibre (such as hair), skin, nails, food material, stone, ceramic, glass, paper, fabrics, wood, leather, metal (for example aluminium) and plastics.

Therefore an embodiment of the present invention is a colorant composition (CC 1 ) comprising

(a) inverse colloidal crystals, which comprise

(i) a regular array of pores dispersed in a solid continuous phase and (ii) at least one broad spectrum absorber contrast agent and/or at least one precursor of a broad spectrum absorber contrast agent.

The colouring composition can also comprise inverse crystals, which comprise no broad spectrum absorber contrast agent and/or precursor of a broad spectrum absorber contrast agent.

A further embodiment of the present invention is a colorant composition (CC 2) comprising

(a) inverse colloidal crystals, which comprise (i) a regular array of pores dispersed in a solid continuous phase and

(ii) at least one broad spectrum absorber contrast agent and/or at least one precursor of a broad spectrum absorber contrast agent and

(b) inverse colloidal crystals which comprise no broad spectrum absorber contrast agent and no precursor of a broad spectrum absorber contrast agent. It is clear that in such a colourant composition which comprises a mixture of inverse colloidal crystals, the inverse colloidal crystals which comprise no broad spectrum absorber contrast agent and no precursor of a broad spectrum absorber contrast agent can be produced in the same way as the inverse colloidal crystal comprising at least one broad spectrum absorber contrast agent.

The colourant compositions of the present invention may typically be in liquid form; semi- liquid form including lotions, pastes, creams; or solid form including powders for example laundry powders or tablets. It is also possible to provide the coloring composition consisting of pure inverse colloidal crystals.

The colourant composition according to the present invention comprise from 0.01 wt-% to 70 wt-%, based on the total weight of the colouring composition, of the inverse colloidal crystals.

In case that the coloring composition is in solid form it also possible that the coloring composition comprises up to 100 wt-%, based on the total weight of the coloring composition, of the inverse colloidal crystals as described above.

A further embodiment of the present invention relates to a colourant composition (CC 3) comprising

(a) 0.01 wt-% to 70 wt-%, based on the total weight of the colourant composition, of inverse colloidal crystals, which comprise (i) a regular array of pores dispersed in a solid continuous phase and

(ii) at least one broad spectrum absorber contrast agent and/or at least one precursor of a broad spectrum absorber contrast agent.

When the colourant composition is in the form of a liquid, gel, mousse, wax or paste, then the composition comprises at least one solvent.

A further embodiment of the present invention relates to a colourant composition (CC 4) comprising

(a) inverse colloidal crystals, which comprise (i) a regular array of pores dispersed in a solid continuous phase and (ii) at least one broad spectrum absorber contrast agent and/or at least one precursor of a broad spectrum absorber contrast agent, and (b) at least one solvent.

Preferably the solvent is an organic solvent, which can be polar or nonpolar. Examples of polar solvents include water, alcohols (mono or poly), esters, ketones and ethers, particularly mono- and di-alkyl ethers of glycols and polyglycols such as monomethyl ethers of mono-, di- and tri-propylene glycols and the mono-n-butyl ethers of ethylene, diethylene and triethylene glycols.

Examples of nonpolar solvents include aliphatic and aromatic hydrocarbons having at least six carbon atoms and mixtures thereof including refinery distillation products and byproducts.

The colourant composition can be prepared as an aqueous or as a nonaqueous solution. Therefore, another embodiment of the present invention relates to a colourant composition as described above, wherein the formulation is nonaqueous.

Therefore, another embodiment of the present invention relates to a colourant composition as described above, wherein the formulation is aqueous.

A further embodiment of the present invention relates to a colourant composition (CC 5) comprising

(ii) at least one broad spectrum absorber contrast agent and/or at least one precursor of a broad spectrum absorber contrast agent, and (b1 ) water, and

(b2) optionally at least one solvent, chosen from the group consisting of alcohols, esters, ketones, ethers and aliphatic and aromatic hydrocarbons having at least six carbon atoms and mixtures thereof including refinery distillation products and by-products.

A further embodiment of the present invention relates to a colourant composition (CC 6) comprising (a) inverse colloidal crystals, which comprise

(i) a regular array of pores dispersed in a solid continuous phase and (ii) at least one broad spectrum absorber contrast agent and/or at least one precursor of a broad spectrum absorber contrast agent, and (b1 ) water, and

Therefore, the present invention also relates to a colourant composition (CC 7) comprising (a) inverse colloidal crystals, which comprise

(i) a regular array of pores dispersed in a solid continuous phase and

(ii) at least one broad spectrum absorber contrast agent and/or at least one precursor of a broad spectrum absorber contrast agent, and

(b) at least one solvent, chosen from the group consisting of alcohols, esters, ketones, ethers and aliphatic and aromatic hydrocarbons having at least six carbon atoms and mixtures thereof including refinery distillation products and by-products.

A further embodiment of the present invention relates to a colourant composition (CC 8) comprising (a) inverse colloidal crystals, which comprise

(i) a regular array of pores dispersed in a solid continuous phase and

But, even when no water is deliberately added to the nonaqueous composition, some adventitious water may be carried into the composition, but generally this will be no more than about 2 wt-% - 4 wt-%, based on the total weight of colourant composition. By definition, the nonaqueous composition of this invention will have no more than about 4 wt-%, and preferably no more than about 2 wt-% water based on the total weight of colourant composition.

The amount of solvent in a colourant composition according to the present invention is typically in the range of about 10 wt-% to about 99.99 wt-%, preferably from about 20 wt- % to about 99.9 wt-%, and more preferably from about 30 wt-% to about 99.9 wt-%, based on total weight of the colourant composition.

The amount of solvent, which is part of the inventive formulation, can vary a lot.

When the composition is used as a concentrate, which is to be diluted (with water and/or other solvents), then the amount of solvents is low, usually between 30 wt-% and 70 wt- %, based on the total weight of the colourant composition. In certain cases the colouring composition can comprise even less that 30 wt-% of solvents.

When the formulation is in a "ready-to-use"-form then the solvent content can be up to 99.99 wt-%, based on the total weight of the colourant composition.

It is obvious that the amount of solvent also depends on the substrate which is to be coatedd or printed as well as on the hue which needs to be obtained.

Therefore, the present invention also relates to a concentrated colourant composition, wherein the amount of solvent lies between 30 wt-% and 70 wt-%, preferably between 40 wt-% and 70 wt-%, more preferably between 50 wt-% and 70 wt-%, based on the total weight of colourant composition.

The present invention also relates to a colourant composition, wherein the amount of water lies between 70 wt-% and 99.99 wt-%, -%, between 80 wt-% and 99.99 wt-%, based on the total weight of the colourant composition.

It also to be stated that the amount of the inverse colloidal crystals as well as of the solvent can vary depending of the physical form of the composition, that means the concentration can vary in case the colourant composition is a solid, liquid, gel, mousse, wax or a paste.

It is also possible to add inverse colloidal crystals which do not comprise any broad spectrum absorber contrast agent and co not comprise any broad spectrum absorber contrast agent.

A further embodiment of the present invention relates to a colourant composition (CC 9) comprising (a) 0.01 wt-% to 70 wt-%, based on the total weight of the colourant composition, of inverse colloidal crystals, which comprise

(i) a regular array of pores dispersed in a solid continuous phase and (ii) at least one broad spectrum absorber contrast agent and/or at least one precursor of a broad spectrum absorber contrast agent, and

(b) 30 wt-% and 99.99 wt-%, based on the total weight of the colourant composition, of at least one solvent.

A further embodiment of the present invention relates to a colourant composition (CC 10) comprising

(a) 0.01 wt-% to 70 wt-%, based on the total weight of the colourant composition, of inverse colloidal crystals, which comprise

97 to 99.999 wt-%, preferably 99 to 99.9999 wt-%, more preferably 99.5 to 99.9999 wt-%, based on the total weight of the inverse colloidal crystal, of silica, metal oxides, metals, metal chalcogenides, metal pnictides and/or organic polymers, and

0.0001 to 3 wt-%, preferably 0.0001 to 1 wt-%, more preferably 0.0001 to 0.5 wt- %, based on the total weight of the inverse colloidal crystal, of at least one broad spectrum absorber contrast agent and/or at least one precursor of a broad spectrum absorber contrast agent chosen from the group consisting of carbon black, black iron oxide, iron hydroxide, silver oxide black K, Ca, Sr, Ba, Zn, Pb, Fe, Ni, Ce, Co, Cr, Cu, Mn, Sn, Al, Ag, Mg, Au, Cd, Ag nitrate, Ag halogenide, Fe nitrate and Fe halogenide,

(b1 ) 30 wt-% and 99.99 wt-%, based on the total weight of the colourant composition, of water, and

(b2) optionally 0.1 wt-% and 89.99 wt-%, based on the total weight of the colourant composition, of at least one solvent, chosen from the group consisting of alcohols, esters, ketones, ethers and aliphatic and aromatic hydrocarbons having at least six carbon atoms and mixtures thereof including refinery distillation products and by- products.

A further embodiment of the present invention relates to a colourant composition (CC 11 ) comprising

(a) 0.01 wt-% to 70 wt-%, based on the total weight of the colourant composition, of inverse colloidal crystals, which comprise 97 to 99.999 wt-%, preferably 99 to 99.9999 wt-%, more preferably 99.5 to 99.9999 wt-%, based on the total weight of the inverse colloidal crystal, of silica, metal oxides, metals, metal chalcogenides, metal pnictides and/or organic polymers, and 0.0001 to 3 wt-%, preferably 0.0001 to 1 wt-%, more preferably 0.0001 to 0.5 wt-

%, based on the total weight of the inverse colloidal crystal, of at least one broad spectrum absorber contrast agent and/or at least one precursor of a broad spectrum absorber contrast agent chosen from the group consisting of carbon black, black iron oxide, iron hydroxide, silver oxide black, K, Ca, Sr, Ba, Zn, Pb, Fe, Ni, Ce, Co, Cr, Cu, Mn, Sn, Al, Ag, Mg, Au, Cd, Ag nitrate, Ag halogenide,

Fe nitrate and Fe halogenide,

(b) 30 wt-% and 99.99 wt-%, based on the total weight of the colourant composition, of at least one solvent, chosen from the group consisting of alcohols, esters, ketones, ethers and aliphatic and aromatic hydrocarbons having at least six carbon atoms and mixtures thereof including refinery distillation products and by-products.

A further embodiment of the present invention relates to a colourant composition (CC 12) comprising

97 to 99.999 wt-%, preferably 99 to 99.9999 wt-%, more preferably 99.5 to 99.9999 wt-%, based on the total weight of the inverse colloidal crystal, of silica, metal oxides, metals, metal chalcogenides, metal pnictides and/or organic polymers and 0.0001 to 3 wt-%, preferably 0.0001 to 1 wt-%, more preferably 0.0001 to 0.5 wt-

Fe nitrate and Fe halogenide, (b1 ) 30 wt-% and 99.99 wt-%, based on the total weight of the colourant composition, of water, and

(b2) optionally 0.1 wt-% and 89.99 wt-%, based on the total weight of the colourant composition, of at least one solvent, chosen from the group consisting of alcohols, esters, ketones, ethers and aliphatic and aromatic hydrocarbons having at least six carbon atoms and mixtures thereof including refinery distillation products and byproducts.

A further embodiment of the present invention relates to a colourant composition (CC 13) comprising

97 to 99.999 wt-%, preferably 99 to 99.9999 wt-%, more preferably 99.5 to 99.9999 wt-%, based on the total weight of the inverse colloidal crystal, of silica, metal oxides, metals, metal chalcogenides, metal pnictides and/or organic polymers and

0.0001 to 3 wt-%, preferably 0.0001 to 1 wt-%, more preferably 0.0001 to 0.5 wt- %, based on the total weight of the inverse colloidal crystal, of at least one broad spectrum absorber contrast agent and/or at least one precursor of a broad spectrum absorber contrast agent chosen from the group consisting of carbon black, black iron oxide, iron hydroxide, silver oxide black, K, Ca, Sr, Ba, Zn, Pb, Fe, Ni, Ce, Co, Cr, Cu, Mn, Sn, Al, Ag, Mg, Au, Cd, Ag nitrate, Ag halogenide, Fe nitrate and Fe halogenide,

A further embodiment of the present invention also relates to a colourant composition (CC 14) formulation which additionally comprises

(c) at least one curing material, and

(d) at least one initiator.

The colourant composition (CC 1 ), (CC 2), (CC 3), (CC 4), (CC 5), (CC 6), (CC 7), (CC 8), (CC 9), (CC 10), (CC 1 1 ), (CC 12) and/or (CC 13) according to the present invention can also comprises at least one curing agent and at least one initiator.

Any kind of commonly known curing agents can be used.

Usually, curing agents are resins which are crosslinkable. These are low molecular or oligomeric polyfunctional compounds with a molecular mass <1000 g/mol. The functional groups which are often terminal groups (for example epoxy-, isocyanate-, amine- or hydroxy-groups) are chosen that way (amount of groups as well as kind of the groups) that they react according to the polyaddition- or polycondensation-mechanism.

Suitable curing agents are epoxy acrylates, polyurethane acrylates, polyester acrylates, acrylated polyols and acrylated polyethers.

Such curing agents are used in an amount of 0.01 wt-% - 15wt-%, based on the total weight of the colourant composition. Preferably, curing agents are present in an amount of 0.1 - 10 wt-%, based on the total weight of the colourant composition.

In combination with the curing agent at least one initiator is used, which starts the polyaddition or polycondensation of the curing agent. This is usually done by light (400 nm - 800nm) or UV-light (100 nm - 400 nm) Such an initiator can be peroxide or peroxide containing compounds, benzophenone and benzophenone derivatives, acetophenone and acetophenone derivatives, benzoin ether derivatives or thioxanthones derivatives.

Such initiators are used in an amount of 0.005wt-% - 10wt-%, based on the total weight of the colourant composition. Preferably, initiators are present in an amount of 0.01 - 8 wt- %, based on the total weight of the colourant composition.

A further embodiment of the present invention relates to a colourant composition (CC 15), which additionally comprises (c) 0.01 wt-% to 15wt-%, based on the total weight of the colourant composition, of at least one curing material, and (d) 0.005wt-% to 10wt-%, based on the total weight of the colourant composition, of at least one initiator.

A further embodiment of the present invention relates to a colourant composition (CC 16), which additionally comprises

(c) 0.01 wt-% to 15wt-%, based on the total weight of the colourant composition, of at least one curing material chosen from the group consisting of epoxy acrylates, polyurethane acrylates, polyester acrylates, acrylated polyols and acrylated polyethers, (d) 0.005wt-% to 10wt-%, based on the total weight of the colourant composition, of at least one initiator chosen from the group consisting of peroxide or peroxide containing compounds, benzophenone and benzophenone derivatives, acetophenone and acetophenone derivatives, benzoin ether derivatives and thioxanthones derivatives.

All the preferences for the curing agent and the initiator in regard to the compounds as well as the concentrations can be applied to the colourant compositions (CC 1 ), (CC 2), (CC 3), (CC 4), (CC 5), (CC 6), (CC 7), (CC 8), (CC 9), (CC 10), (CC 11 ), (CC 12) and/or (CC 13) as described above as well.

Additionally the colouring composition (CC 1 ), (CC 2), (CC 3), (CC 4), (CC 5), (CC 6), (CC 7), (CC 8), (CC 9), (CC 10), (CC 1 1 ), (CC 12), (CC 13), (CC 14), (CC 15) and/or (CC 16) can comprise further auxiliaries. Such auxiliaries are these commonly used in the field of colouring, such as coating and printing.

Auxiliaries are those additional chemicals which are used to improve the results of the coating or coating process. Furthermore, under the term auxiliaries is to be understood the chemicals, which help to improve the property of the formulation itself, such as storage, better manipulability of the colourant composition, etc.

Examples of auxiliaries are wetting agents, buffer substances, antistatic agents, bleaching agents, oxidation agents, rheology modifiers, solubilizers, siccative, antifoams, levelling agents, surfactants, electrolytes, foam suppressants, antifreezing agents or fungistatic and/or bacteriostatic agents, optical brighteners, softeners, flameproofing additives, or dirt repellents, water repellents and oil repellents, as well as water softeners and natural or synthetic thickeners, e.g. alginates and cellulose ethers.

Such auxiliaries are usually present in a smaller amount, which can go up to about 10 wt- %, based on the total weight of the colourant composition.

If one or more auxiliaries are present the amount goes usually from 0.1 wt-% to 10 wt-%, based on the total weight of the colourant composition.

Therefore a further embodiment of the present invention relates to a colourant composition as described above comprising additionally at least one auxiliary. Therefore a further embodiment of the present invention relates to a colourant composition (CC 17) additionally comprising (e) at least one auxiliary.

Therefore a further embodiment of the present invention relates to a colourant composition (CC 18) additionally comprising

(e) at least one auxiliary chosen from the group consisting of wetting agents, buffer substances, antistatic agents, bleaching agents, oxidation agents, rheology modifiers, solubilizers, siccative, antifoams, levelling agents, surfactants, foam suppressants, antifreezing agents or fungistatic and/or bacteriostatic agents, optical brighteners, softeners, flameproofing additives, or dirt repellents, water repellents and oil repellents, as well as water softeners and natural or synthetic thickeners, e.g. alginates and cellulose ethers.

Another embodiment of the present invention relates to a colourant composition (CC 19) additionally comprising

(e) 0.1 wt-% to 10 wt-%, based on the total weight of the colourant composition, of at least one auxiliary.

Another embodiment of the present invention relates to a colourant composition (CC 20) additionally comprising

(e) 0.1 wt-% to 10 wt-%, based on the total weight of the colourant composition, of at least one auxiliary from the group consisting of wetting agents, buffer substances, antistatic agents, bleaching agents, oxidation agents, rheology modifiers, solubilizers, siccative, antifoams, levelling agents, surfactants, foam suppressants, antifreezing agents or fungistatic and/or bacteriostatic agents, optical brighteners, softeners, flameproofing additives, or dirt repellents, water repellents and oil repellents, as well as water softeners and natural or synthetic thickeners, e.g. alginates and cellulose ethers.

All the preferences for the curing agent and the initiator in regard to the compounds as well as the concentrations can be applied to the colourant compositions (CC 1 ), (CC 2), (CC 3), (CC 4), (CC 5), (CC 6), (CC 7), (CC 8), (CC 9), (CC 10), (CC 11 ), (CC 12), (CC 13), (CC 14), (CC 15) and/or (CC 16) as described above as well. As already mentioned the colourant compositions according to the present invention can be in any suitable physical form. Usually it is in the form of a solid, liquid, a gel, mousse, wax or a paste.

A further embodiment of the present invention relates to a colourant composition as described above, which is a printing and/or coating formulation.

The printing process can be done according to any well known processes such as Ink Jet (such as Bubble Jet, Compound jet, Dry InkJet, Hotmelt InkJet), relief printing, intaglio, letterpress, lithography, flexography, gravure, screen printing and pad printing.

Therefore the formulations have to be adapted to the desired form of printing technology.

Formulations for the inkjet technology comprising monodisperse particles are for example known from WO2005/063902.

Therefore a further embodiment of the present invention relates to a colourant composition which is a printing formulation for Ink Jet (such as Bubble Jet, Compound jet,

Dry InkJet, Hotmelt InkJet), relief printing, intaglio, letterpress, lithography, flexography, gravure, screen printing and pad printing.

The colourant composition as described in the present patent application can also be used for any known coating technology.

Therefore the formulations have to be adapted to the desired form of coating technology.

Suitable coating processes are for example air knife coating, immersion (dip) coating, Gap Coating, Curtain coating, rotary screen, Reverse Roll coating, Gravure coating, Metering rod (Meyer bar) coating, Slot Die (Extrusion) coating and Hot Melt coating.

The colourant compositions according to the present invention can also be used in personal care formulations especially in cosmetic formulations.

Therefore a further embodiment of the present invention is the use of inverse colloidal crystals as described above and colourant compositions as described above in personal care formulations and/or cosmetic formulations. Therefore a further embodiment of the present invention also relates to personal care formulations and/or cosmetic formulations comprising at least one inverse colloidal crystals as described above and/or at least one colourant composition as described above.

The personal care formulations and/or cosmetic formulations can have any usual form of application. They can be in the form of, for example, solutions, suspensions, emulsions, PIT emulsions, pastes, ointments, gels, creams, lotions, powders, soaps, surfactant- containing cleansing preparations, oils, mousses, waxes, aerosols, sprays and sticks.

The personal care formulations and/or cosmetic formulations can be used for any personal care and/or cosmetic application. They can be used for example as lipsticks, lip- cares sticks, mascara, eyeliner, eye-shadow, rouge, powder make-up, emulsion makeup, wax make up, nail lacquer, shampoos and shower compositions.

The personal care formulations as well as the cosmetic formulations may comprise any commonly used ingredients and additives for a cosmetic use, such as solvents, further dyes and/or pigments, antioxidants, repellents, vitamins, UV-absorbers, solutes, self- tanning agents, preservatives, antioxidants, stabilisers, solubilisers, vitamins, colorants and odour improvers.

Preferred cosmetic compositions are those suitable for the application to human skin, which optionally, but preferably, include a skin benefit agent in addition to the colourant compositions of the present invention. Suitable additional skin benefit agents include anti-aging, wrinkle-reducing, skin whitening, anti-acne and sebum reduction agents. Examples of these include alpha-hydroxy acids, beta-hydroxy acids, polyhydroxy acids, hydroquinone, t-butyl hydroquinone, Vitamin B and C derivatives, dioic acids, retinoids; betulinic acid; vanillic acid; allantoin, a placenta extract; hydrolactin; and resorcinol derivatives.

Following a suitable contact time, excess composition can be removed/washed off if necessary. Preferably the cosmetic composition is in contact with the skin, nail or hair for sufficient time such that at least two or three colloidal crystalline layers are formed. The concentration of the ingredients can vary a lot, but a person skilled in the art knows which concentration of a specific ingredient is necessary to produce the various application forms.

The new inverse colloidal crystals according to the present invention can be used in any known personal care formulations and cosmetic formulations. Suitable formulations can be found for example in US2006002875.

Therefore a further embodiment of the present invention is a personal care formulation comprising at least one inverse colloidal crystal according to the present invention.

Therefore a further embodiment of the present invention is a cosmetic formulation comprising at least one inverse colloidal crystal according to the present invention.

A further area of application for the inverse colloidal crystals according to the present invention is the security sector with various applications, for example in bank notes, credit cards, visas, tax seals or the like.

Therefore a further embodiment of the present invention is a security printing and/or coating ink comprising at least one inverse colloidal crystal according to the present invention.

Such an ink is used to produce security marking, thread or device, hologram, hot stamping foil or watermark, in particular for the purpose of prevention of counterfeiting, authentification, verification, or identification of data or information, comprising an optically variable marking as described above and below.

The security elements also comprise an additional detectable security feature, in particular an optically, machine or haptically detectable security feature.

Therefore a further embodiment of the present invention is a security printing and/or coating ink comprising at least one inverse colloidal crystal according to the present invention as described above and at least one additional detectable security feature, in particular an optically, machine or haptically detectable security feature. Optically detectable security features are those which can be detected by without using an apparatus or with the help of a simple apparatus.

Machine detectable security features are those which can be detected by using an apparatus able to detect luminous, magnetic, electrically conductive, thermoelectronical or piezoelectronical properties.

Haptically detectable security features are those which can be detected by the human sense of touch.

In WO2006/045567 there can be found compounds which are added to obtain these additional detectable security features.

The inverse colloidal crystals according to the present invention and/or the colouring compositions can also be used for home care applications. The inverse colloidal crystals and/or compositions are used usually to give the product a specific visual appearance.

The colourant compositions of the present invention may be applied to any suitable substrate to colour at least a region of the substrate. A structural colour effect is produced due to direct reflection and/or diffraction of light in the wavelength of visible light by the colloidal crystal. Substantially all of the light that is diffused by the colloidal crystal is absorbed by the broad spectrum absorber contrast agent. This causes an enhancement of the structural colour effect. The substrate to be coloured can have any possible form as well as size.

Materials for printing an coating include fibre (such as hair), skin, nails, food material, stone, ceramic, glass, paper, fabrics, wood, leather, metal (for example aluminium) and plastics.

The object to be coated can also be a combination of various substrates and it can have any form.

The coating and/or printing formulations according to the present invention are very suitable to colour (completely or in parts) packaging, which are for example used to sell commercial products, such as toothpaste containers, cans for drinks, shampoo containers, shower gel containers etc. The colourant compound can also be used to print labels, which are then put onto a specific embodiment.

According to another aspect of the present invention, there is provided the use of a colourant composition as hereinbefore defined for colouring a substrate.

According to another aspect of the present invention, there is provided a method of colouring a substrate, which method comprises the step of contacting at least a region of the substrate with a colourant composition as hereinbefore defined.

It is not essential for the whole of the substrate to be contacted with the colourant composition. In other words, the coverage need not be complete, i.e. it can be discontinuous.

Suitable substrates include any substrate upon which a colloidal crystalline layer may form. Suitable substrates include, for example, fibre (such as hair), skin, nails, food material, stone, ceramic, glass, paper, fabrics, wood, leather, metal (for example aluminium) and plastics.

When the substrate is a food material, the colourant composition must be of a grade that can be used in food materials. Food materials in which the colourant compositions of the present invention may be used include, for example, eggs, fruit, vegetables, ice creams, sauces, water ice and chocolate.

For examples when vegetables or fruits are used, it is possible to coat the parts and/or print onto the parts which can be eaten as well as the parts, which are (usually) not eaten, like the peel, leaves, etc.

When the substrate is a plastics material, the colourant composition of the present invention may be dispersed in the plastics material, which may then be moulded for example by injection moulding, injection blow moulding or blow moulding. The substrate may further comprise a protective material, for example as a protective covering or coating. The protective covering or coating may, for example, comprise a clear lacquer layer on a surface of the colloidal crystalline layer. Alternatively, the protective material may be formed in situ, for example by providing monodisperse particles having appropriately modified surfaces.

Thus, according to one aspect of the present invention, there is provided the use of a colourant composition as hereinbefore defined for colouring the hair of an individual.

There is also provided a method of colouring the hair of an individual which method comprises the step of contacting at least a region of the hair of the individual with a colourant composition as hereinbefore defined such that a colloidal crystalline layer forms on the hair.

There is also provided a hair dye composition comprising a colourant composition as hereinbefore defined.

The hair dye compositions of the present invention may be in any suitable form. For example, the hair dye compositions may be in the form of sprays, lotions, shampoos, creams or pastes which can be applied directly to all or part of the hair. Following a suitable contact time, excess composition can then be washed off if necessary.

According to another aspect of the present invention, there is provided the use of a colourant composition as hereinbefore defined for colouring a fabric.

Colouring of fabrics includes the 'brightening' of fabrics, such in the case of white textile materials.

According to another aspect of the present invention, there is provided a method of colouring a fabric which method comprises the step of contacting at least a region of the fabric with a colourant composition as hereinbefore defined.

Colorant compositions for use in colouring fabrics can be applied as part of standard laundry formulations known in the art such as powders or tablets that dissolve/disperse in water or as liquids.

According to another aspect of the present invention, there is provided a fabric dye composition comprising a colourant composition as hereinbefore defined. Suitable fabrics include natural and synthetic fabrics. Examples of natural fabrics include wool, silk, fur, cellulosic materials such as cotton, flax, linen and hemp. Synthetic fabrics include, for example, viscose, nylon (polyamide), acrylic (polyacrylonitrile), aramid (aromatic polyamide) and polyester. The fabric may be in any suitable form, for example woven, non-woven or knitted.

The fabric dye composition of the present invention may be in any suitable form. For example, the fabric dye composition may be in the form of a solid, a liquid or a paste.

According to another aspect of the present invention, there is provided the use of a colourant composition as hereinbefore defined for colouring paper. According to another aspect of the present invention, there is provided a method of colouring paper which method comprises the step of contacting at least a region of the paper with a colourant composition as hereinbefore defined.

By the term "paper" we mean any material that is manufactured in sheets from the pulp of wood or other fibrous substances and that is manufactured for any use, including for example writing or printing on, wrapping or packaging.

According to another aspect of the present invention, there is provided an ink composition comprising a colourant composition as hereinbefore defined. For example, the ink composition is suitable for printing on a printable surface such as paper or fabric.

Ink compositions of the present invention can typically be applied to a substrate using standard printing techniques known in the art for applying inks to a range of substrates. Typically, the ink compositions are applied to the substrate to form letters, numerals and/or other symbols, and/or graphic designs.

When the colourant compositions of the present invention are used to colour natural substrates, such as hair, nail, tooth and natural fabrics such as wool or cotton, the compositions typically comprise from 0.01 to 4% (preferably from 0.01 to 4%) by weight of the inverse colloidal crystals. When the colourant compositions of the present invention are used to colour synthetic substrates, the compositions typically comprise from 0.5 to 30% (preferably from 1 to 20%) by weight of the inverse colloidal crystals. The various features and embodiments of the present invention, referred to in individual sections above apply, as appropriate, to other sections, mutatis mutandis. Consequently features specified in one section may be combined with features specified in other sections, as appropriate.

All publications mentioned in the above specification are herein incorporated by reference. Various modifications and variations of the described methods and products of the invention will be apparent to those skilled in the art without departing from the scope of the invention. Although the invention has been described in connection with specific preferred embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments. Indeed, various modifications of the described modes for carrying out the invention which are apparent to those skilled in the relevant fields are intended to be within the scope of the following claims.

The present invention will now be described further with reference to the following non- limiting examples.

Drawing Description:

FIG. 1.: Representative SEM image of the top view of the OC-I replica made from the PMMA opal template having a sphere diameter of 370 nm: a) Low magnification; b) high magnification. FIG. 2.: Digital image of powder of inverse crystals consist of silica without contrast agent showing predominately white appearance FIG. 3.: Digital image of powder of inverse crystals consist of titanium without contrast agent showing predominately white appearance

FIG. 4.: EDX pattern of silica inverse opals having elemental silver incorporated. FIG. 5.: Digital image of powder of inverse crystals consist of silica with Ag as contrast agent showing strong turquoise appearance FIG. 6.: Digital image of powder of inverse crystals consist of silica with carbon as contrast agent showing strong greenish appearance

Example 1 - Production of an Inverse Colloidal Crystal consisting of SiO? having no contrast agent encapsulated (COMPARATIVE EXAMPLE) Colloidal crystalline pieces comprised of monodisperse polymethylmethacrylate (PMMA) spheres (350nm) were prepared by evaporation of the dispersant from a colloidal dispersion (10% by weight concentration) in a glassy petri dish under an IR lamp for 1-48 hours. Pieces of colloidal crystal were formed (about 1-3 mm³) as indicated by strong iridescent colors and dipped into a solution which consist of a mixture of tetraethylorthosilicate, ethanol, water and hydrochloric acid (38%) in a ratio of 6:4:3:1 respectively, which led infiltration of the precursor solution. The duration of the process takes from 10 minutes to 15 days. Then the composite is carefully transferred into an oven and calcination was initiated at about 575 degree Celsius for 8 h, causing the formation of titanium dioxide and burning out the latex particles. An inverse opal structure of SiO₂ remains behind. Fig 1 shows the remaining skeleton and Fig 2 the appearance of it.

The visual perception of the obtained product of is significantly weaker than the one of the product of Example 3 or 4.

Example 2 - Production of an Inverse Colloidal Crystal consisting of TiO? having no contrast agent encapsulated (COMPARATIVE EXAMPLE)

Same as in example 1 but, the colloidal pieces (0.2g) were dipped into a mixture of titanium propoxide, ethanol, water and hydrochloric acid (38%) with a ratio 5:5:2:1 , respectively. The composite is carefully transferred into an oven and calcination was initiated at 575 degree Celsius for 8 h, causing the formation of titanium dioxide and burning out the latex particles. An inverse opal structure of TiO₂ remains behind.

Fig.3 shows a digital image of the white powder.

Example 3 - Production of an Inverse Colloidal Crystal having silver and/or silver oxide as contrast agent encapsulated (In-situ generation of elemental silver from silver salts)

Pieces (0.2g) of inverse opals comprised of silica oxide or titania oxide were deposited on a filter paper in a Buchner funnel. 5 ml of an ammoniac al silver nitrate solution (0.2M) was added drop wise to cover completely the silica inverse opals powder while suction was applied. Typically, this was repeated three times. The filter paper was then removed and the composite was then calcinated in an oven at 100⁰C for two days. Here, the precursor silver ions were in-situ converted to elemental silver as contrast agent. The powder shows strong turquoise colour (Fig 5), having improved optical properties as compared to the non-contrast agent encapsulated material (Example 1 ; Fig 2). Fig 4 shows the EDX pattern of inverse opals after infiltration with silver. It is proved the existence of silver particles in inverse opals.

Example 4 - Production of an Inverse Colloidal Crystal having carbon black as contrast agent encapsulated (In-situ generation of carbon black from sugar solution)

Pieces (0.2g) of inverse opals comprised of silica oxide or titania oxide were deposited on a filter paper in a Buchner funnel. 5ml Sugar solution (10wt% - 30wt%) was added drop wise to cover completely the silica inverse opals powder while suction was applied. Typically, this was repeated three times. The filter paper was then removed and the composite was then calcinated in an oven by increasing the temperature from ambient to 300⁰C at a rate of 4⁰C min^"1, and then stabilized at 300⁰C for 3h. Here, carbonization of sugar to carbon black takes place. Here the contrast agent was generated in-situ. The powder shows strong blueish colour, having improved optical properties as compared to the non-contrast agent encapsulated material.

Fig.6: shows the product of Example 4.

Claims

1. An inverse colloidal crystal comprising

(i) a regular array of pores dispersed in a solid continuous phase and (ii) at least one broad spectrum absorber contrast agent and/or at least one precursor material of a broad spectrum absorber contrast agent.

2. An inverse colloidal crystal according to claim 1 , wherein the pores have a diameter between 0.05 and 50 μm, preferably between 0.05 - 40μm, more preferably between 0.05 - 30μm.

3. An inverse colloidal crystal according to any of the preceding claims, wherein the broad spectrum absorber contrast agent is incorporated into the solid continuous phase.

4. An inverse colloidal crystal according to claim 1 or claim 2, wherein the broad spectrum absorber contrast agent is on the surface of the solid continuous phase

5. An inverse colloidal crystal according to claim 1 or claim 2, wherein the broad spectrum absorber contrast agent is incorporated into the solid continuous phase and on the surface of the solid continuous phase

6. An inverse colloidal crystal according to any of the preceding claims, wherein the broad spectrum absorber contrast agent is a mixture of compounds wherein that mixture has the same absorption property as a single broad spectrum absorber contrast agent.

7. An inverse colloidal crystal according to any of the preceding claims, wherein the broad spectrum absorber contrast agent is chosen from the group consisting of Ag, carbon black, black iron oxide, iron hydroxide and silver oxide black.

8. An inverse colloidal crystal according to any of the preceding claims, wherein the precursors of the broad spectrum absorber contrast agent is chosen from the group consisting of metal salts, preferably hydrophilic metal salts, such as nitrates or halogenides.

9. An inverse colloidal crystal according to any of the preceding claims, wherein the precursors of the broad spectrum absorber contrast agent is chosen from the group consisting of K, Ca, Sr, Ba, Zn, Pb, Fe, Ni, Ce, Co, Cr, Cu, Mn, Sn, Al, Ag, Mg, Au, Cd, Ag nitrate, Ag halogenide, Fe nitrate and Fe halogenide.

10. An inverse colloidal crystal according to any of the preceding claims, wherein the solid continuous phase comprises silica, metal oxides, metals, metal chalcogenides, metal pnictides and/or organic polymers.

1 1. An inverse colloidal crystal according to any of the preceding claims, comprising up to 5 wt-%, based on the total weight of the inverse colloidal crystal, of at least one broad spectrum absorber contrast agent and/or at least one precursor of a broad spectrum absorber contrast agent.

12. An inverse colloidal crystal according to any of the preceding claims, comprising 0.0001 to 3 wt-%, preferably 0.0001 to 1 wt-%, more preferably 0.0001 to 0.5 wt- %, based on the total weight of the inverse colloidal crystal, of at least one broad spectrum absorber contrast agent and/or at least one precursor of a broad spectrum absorber contrast agent.

13. An inverse colloidal crystal according to any of the preceding claims, comprising up to 99.9999 wt-%, based on the total weight of the inverse colloidal crystal, of the solid continuous phase.

14. An inverse colloidal crystal according to any of the preceding claims, comprising 97 to 99.9999 wt-%, preferably 99 to 99.9999 wt-%, more preferably 99.5 to 99.9999, based on the total weight of the inverse colloidal crystal, of the solid continuous phase.

15. Process for producing inverse colloidal crystals according to any of claims 1 - 14, which is characterized in by conducting the steps of:

(i) providing colloidal crystals formed of a regular array of monodisperse particles, wherein the colloidal crystal comprises at least one broad spectrum absorber contrast agent and/or at least one precursor of a broad spectrum absorber contrast agent; (ii) adding a material so as to introduce a solid into the interstices between the monodisperse particles in the colloidal crystals and to form a solid continuous phase; and

16. Process for producing inverse colloidals crystal according to any of claims 1 - 14, which is characterized in by conducting the steps of:

(i) providing colloidal crystals formed of a regular array of monodisperse particles, wherein the colloidal crystal comprises at least one broad spectrum absorber contrast agent and/or at least one precursor of a broad spectrum absorber contrast agent;

(ii) adding a material so as to introduce a solid into the interstices between the monodisperse particles in the colloidal crystals and to form a solid continuous phase, wherein the material comprises at least one broad spectrum absorber contrast agent and/or at least one precursor of a broad spectrum absorber contrast agent; and

17. Process for producing inverse colloidal crystals according to any of claims 1 - 14, which is characterized in by conducting the steps of:

(i) providing colloidal crystals formed of a regular array of monodisperse particles; (ii) adding a material so as to introduce a solid into the interstices between the monodisperse particles in the colloidal crystals and to form a solid continuous phase, wherein the material comprises at least one broad spectrum absorber contrast agent and/or at least one precursor of a broad spectrum absorber contrast agent; and (iii) removing the monodisperse particles so as to form a regular array of pores in the solid continuous phase.

18. A process according to claims 15 - 17 wherein the monodisperse particles are silica spheres.

19. A process according to claims 15 - 17 wherein the monodisperse particles are formed from hydrophobic monomers chosen from the group consisting of styrenics, acrylonitrile, methacrylonitrile, acrylates, methacrylates, methacryl amides, acrylamides, maleimides, vinyl ethers, vinyl esters, monoalkylmaleates, dialkyl maleates, fluorinated acrylates and fluorinated methacrylates.

20. A process according to claims 15 - 17 wherein the monodisperse particles are formed from hydrophobic monomers chosen from the group consisting of acrylates, methacrylates, fluorinated acrylates and fluorinated methacrylates.

21. A process according to claims 15 - 20 wherein the broad spectrum absorber contrast agent and/or the precursor of a broad spectrum absorber contrast agent is located on the surface of monodisperse particles and/or between the monodisperse particles and/or encapsulated in the monodisperse particles.

22. A process according to claims 15 - 21 wherein the broad spectrum absorber contrast agent and/or the precursors of a broad spectrum absorber contrast agent are organic.

23. A process according to claims 15 - 21 wherein the broad spectrum absorber contrast agent and/or any precursor of a broad spectrum absorber contrast agent are inorganic.

24. A process according to claims 15 - 23 wherein the material, which forms the solid continuous phase, is a solid or a liquid or a gas as well a mixture of these phases.

25. A process according to claims 15 - 24 wherein the material, which forms the solid continuous phase, comprises at least one broad spectrum absorber contrast agent and/or at least one precursor of a broad spectrum absorber contrast agent.

26. A process according to claims 15 - 25, wherein the material, which forms the solid continuous phase, is a silica, metal oxides, metals, metal chalcogenides, metal pnictides and organic polymers solution.

27. A process according to claims 15 - 27, wherein step (ii) is conducted by metal- organic chemical vapour deposition, by high-pressure high-temperature processes or by sol-gel processes.

28. A process according to claims 15 - 27, wherein the monodisperse particles may be removed from the structure by etching.

29. A process according to claims 15 - 27, wherein the monodisperse particles may be removed from the structure by heating and/or electromagnetic radiation.

30. Use of at least one inverse colloidal crystal according to claim 1 - 14 in a colourant composition.

31. A colourant composition comprising inverse colloidal crystals according to claim 1 - 14.

32. A colourant composition according claim 31 comprising from 0.01 wt-% to 70 wt- %, based on the total weight of the colouring composition, of inverse colloidal crystals.

33. A colourant composition according to claim 31 and 32 comprising (b) at least one solvent.

34. A colourant composition according to any of claims 31 - 33 comprising (b1 ) water, and

35. A colourant composition according to any of claims 31 - 33 comprising

36. A colourant composition according to any of claims 31 - 35 comprising

37. A colourant composition according to any of claims 31 - 36 comprising

(c) at least one curing material, and

(d) at least one initiator.

38. A colourant composition according to claims 37, wherein the curing agent is chosen from the group consisting of epoxy acrylates, polyurethane acrylates, polyester acrylates, acrylated polyols and acrylated polyethers.

39. A colourant composition according to claims 37 and 38 comprising 0.01 wt-% - 15wt-%, based on the total weight of the colourant composition, of the curing agent.

40. A colourant composition according to any of claims 37 - 39, wherein the initiator is chosen from the group consisting of peroxide or peroxide containing compounds, benzophenone and benzophenone derivatives, acetophenone and acetophenone derivatives, benzoin ether derivatives, thioxanthones derivatives.

41. A colourant composition according to any of claims 37 - 40 comprising 0.01 wt-% - 15 wt-%, based on the total weight of the colourant composition, of at least one initiator.

42. A colourant composition according to any of claims 31 - 41 comprising

(e) at least one auxiliary.

43. A colourant composition according to any of claims 31 - 42 comprising (e) at least one auxiliary chosen from the group consisting of wetting agents, buffer substances, antistatic agents, bleaching agents, oxidation agents, rheology modifiers, solubilizers, siccative, antifoams, levelling agents, surfactants, foam suppressants, antifreezing agents or fungistatic and/or bacteriostatic agents, optical brighteners, softeners, flameproofing additives, or dirt repellents, water repellents and oil repellents, as well as water softeners and natural or synthetic thickeners, e.g. alginates and cellulose ethers.

44. A colourant composition according to any of claims 31 - 43 comprising (e) 0.1 wt-% to 10 wt-%, based on the total weight of the colourant composition, of at least one auxiliary.

45. A colourant composition according to any of claims 31 - 44, characterized in that is in the form of a solid, liquid, a gel, mousse, wax or a paste.

46. A colourant composition according to any of claims 31 - 45, which is a coating and/or a printing formulation.

47. A printing formulation according to claim 46, which is a used for Ink jet (such as Bubble Jet, Compound jet, Dry InkJet, Hotmelt InkJet), relief printing, intaglio, letterpress, lithography, flexography, gravure, screen printing and pad printing.

48. A colourant formulation according to claim 46, which is used as a coating formulation for knife coating, immersion (dip) coating, Gap Coating, Curtain coating, rotary screen, Reverse Roll coating, Gravure coating, Metering rod

(Meyer bar) coating, Slot Die (Extrusion) coating and Hot Melt coating.

49. Use of at least one inverse colloidal crystals according to claims 1 - 12 and/or at least one colourant compositions according to claims 29 - 45 in personal care formulations and/or cosmetic formulations.

50. Personal care formulation and/or cosmetic formulation comprising at least one inverse colloidal crystals according to Claims 1 - 14 and/or at least one colourant compositions according to claims 31 - 45 .

51. A security printing and/or coating ink comprising at least one inverse colloidal crystal according to claim 1 - 14.

52. Use of a colourant composition according to claims 31 - 49 and 51 for colouring a substrate.

53. Use according to claim 52, wherein substrate is chosen from the group consisting of fibre (such as hair), skin, nails, food material, stone, ceramic, glass, paper, fabrics, wood, leather, metal (for example aluminium) and plastics.

54. Substrate printed and/or coated with a colourant composition according to claims 31 - 49 and 51.

55. Substrate according to claim 54, which is chosen from the group consisting of fibre (such as hair), skin, nails, food material, stone, ceramic, glass, paper, fabrics, wood, leather, metal (for example aluminium) and plastics.