Non-film-forming composition for coloring fibers and process for treating fibers

Description

1 / 20 “NON-FILM-FORMING COMPOSITION FOR COLORING FIBERS AND PROCESS FOR TREATING FIBERS” FIELD OF THE INVENTION

[001] The present disclosure relates to a composition for coloring fibers, such as keratin fibers, the composition comprising a polyelectrolyte having a controllable net charge from a positive net value at a first pH and a neutral or negative net charge at a second different pH, such that the net charge of the polyelectrolyte complexes has a controllable net charge via adjustment of the pH of the carrier medium. BACKGROUND OF THE INVENTION

[002] The dyeing of natural or synthetic fibers is well known. Dyeing treatments color natural or synthetic fibers and change their appearance, texture, and other physical properties.

[003] Direct dyeing and oxidative dyeing are techniques for coloring hair and other fibers. However, these techniques can have disadvantages such as degradation of the colored fibers, skin irritation, lack of uniformity, and irreversibility. An alternative for dyeing fibers is through the adhesion of pigments to the fiber surface. An advantage of pigment dyeing, also called pigment coloring, is that it is possible to dye dark fibers without prior bleaching, such as naturally dark-colored hair, when the pigment composition generally adheres to the exterior of the fiber. Typically, a pigment adhesion dyeing process comprises the provision of a composition comprising a pigment and a film-forming polymer. The composition comprising the pigment and film-forming polymer dyes the hair and allows for coloring without damage to the fiber.A film-forming polymer is generally a polymer that is capable of forming a cohesive, continuous film attached to the fiber.

[004] However, the present pigment compositions comprising film-forming polymers have disadvantages in that the film-forming polymer inherently alters the physical properties of each fiber and may result in Petition 870250094090, dated 10 / 15 / 2025, pp. 100 / 119 2 / 20 each fiber having an artificial feel. In particular, the fibers may have a rough feel and a dull appearance. Additionally, the fibers may be difficult to comb or brush.

[005] Additionally, since dyeing textiles is a water-intensive and generally irreversible process, techniques that allow for reversible dyeing of textile fibers would be advantageous. Reversible dyeing compositions and processes can allow for reduced overall water consumption, as they allow textiles to be removed and / or re-dyed and subsequently reused. While removable coloring is relevant in the industrial dyeing of textiles, it is also important in cosmetic hair coloring, as simplifying color removal and subsequent reapplication increases the flexibility of hair coloring compositions.

[006] Improved fiber dyeing processes and compositions based on pigments would be advantageous. SUMMARY OF THE INVENTION

[007] Therefore, the present invention preferably seeks to reduce, alleviate or eliminate one or more of the above-identified deficiencies in the art and disadvantages, either alone or in any combination, and solves at least the aforementioned problems by providing a non-film-forming composition for coloring fibers, the composition comprising a dispersion of pigment particles in a carrier medium, and a polyelectrolyte having a controllable net charge from a net positive value at a first pH and a neutral or negative net charge at a second different pH, such that the net charge of the polyelectrolyte has a controllable net charge via adjustment of the pH of the carrier medium. The polyelectrolyte is adsorbed onto the surface of each of the dispersed pigment particles forming pH-responsive pigment particles, wherein the net electrical charge of the pH-responsive pigment particles is adjustable by adjusting the pH of the carrier medium.

[008] A process for treating fibers, such as keratin fibers, is provided Petition 870250094090, dated 10 / 15 / 2025, pp. 101 / 119 3 / 20 as well.

[009] Additional advantageous embodiments are disclosed in the attached and dependent patent claims. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 shows a graph of the relationship between pH-responsive particle size and the total mass of polymers present in the composition. The graph details a result from experiment 1. The horizontal geometric axis shows the total mass of polymers present in the composition in grams. The vertical geometric axis shows the size of the pH-responsive pigment particles in nm; Figure 2 shows a graph of the zeta potential curve versus pH for pH-responsive pigment particles comprising an additional polyelectrolyte, CMC. The graph details a result from experiment 1. The vertical geometric axis shows the zeta potential in mV, the horizontal geometric axis shows pH; and Figure 3 shows a graph of the zeta potential of a variety of compositions comprising different amounts of an additional polyelectrolyte, CMC. The vertical geometric axis shows the zeta potential in mV, while the horizontal geometric axis shows the pH. DETAILED DESCRIPTION

[010] The composition for coloring fibers disclosed in the present invention is based on the development of pigment dyeing formulations allowing the coloring of fibers and the aforementioned discoloration, or removal of color from the fibers.

[011] The fibers to be colored can be, for example, fibers based on natural cellulose such as cotton, linen, or other cellulose-based fibers; keratin fibers, such as human hair or wool. The composition is especially suitable for application on and coloring of keratin fibers, such as human hair.

[012] The composition comprises pigment particles in a carrier medium. The pigment particles are modified via the adsorption of a chemical agent, having a controllable, modifiable net charge via pH adjustment of the composition. Petition 870250094090, dated 10 / 15 / 2025, pp. 102 / 119 4 / 20 comprising the pigment particle and the net charge modifiable chemical agent. The pigment particle and the chemical agent, combined, having a net charge controllable via pH adjustment of the composition, is referred to hereinafter as the pH-responsive pigment particle. That is, the pigment particle has become pH-responsive so that it has a net charge dependent on the pH of the composition or, in general, the pH of the environment to which the pH-responsive pigment particle is exposed.

[013] To achieve fiber coloring, the pH-responsive pigment particle comprising the pigment particle and the chemical agent adsorbed onto the pigment particle must have a charge opposite to the charge of the fiber to be colored. The term “opposite” refers to the charge having an opposite sign, not the absolute values ​​being equal. Many natural fibers, such as keratin fibers, and in particular human hair, generally have a natural negative charge at a typical treatment pH, such as neutral pH, slightly alkaline pH, or slightly acidic pH. By ensuring that the pH-responsive pigment particle has a net positive charge, the pH-responsive pigment particle comprising the pigment particle and the modifiable chemical agent adsorbed will be attracted to and adsorbed onto the surface of fibers, such as keratin fibers.Thus, the fibers will be colored by pigment adsorption as a result of electrostatic interaction and van der Waals interactions between the surfaces of the pH-responsive pigment particle and the fiber.

[014] When it is desired to remove pH-responsive pigment from the fiber, the pH-responsive pigment particle must be negatively charged, so that repulsive electrostatic interactions between the pH-responsive pigment particle and the fiber desorb the pH-responsive pigment particle from the fiber surface.

[015] The present composition and processes allow for the coloring and decolorization of fibers, such as keratin fibers, without substantially altering the fibers themselves. The composition comprising pH-responsive pigment particles, and in particular, the pH-responsive pigment particle that does not dissolve or diffuse into Petition 870250094090, dated 10 / 15 / 2025, pp. 103 / 119 5 / 20 fibers. The pH-responsive pigment particle attaches to the outer surface of the fibers and subsequently remains detached from the fiber to which it is attached.

[016] As mentioned above, the chemical agent having a modifiable net charge is adsorbed onto the surface of the pigment particle. In the composition, the majority, for example, more than 50%, more than 80%, more than 90%, more than 95% of the chemical agent having a modifiable net charge must be adsorbed onto the surface of the pigment particle. The chemical agent having a modifiable net charge should not generally be freely dispersed, separated from the pigment particle, in the composition.

[017] A chemical agent having a modifiable net charge may have a net positive charge at a first pH. A chemical agent having a modifiable net charge may have a neutral or net negative charge at a second pH, wherein the second pH is different from, generally greater than, the first pH. A chemical agent having a modifiable net charge may have a net positive charge at a pH less than 10, for example, less than 9, less than 8. A chemical agent having a modifiable net charge may have a neutral or negative charge at a pH greater than about 8, for example, greater than about 9, such as greater than about 10.

[018] A chemical agent having a controllable, modifiable net charge via pH adjustment may be a polyelectrolyte. The polyelectrolyte may have a net positive charge at a first pH. The polyelectrolyte may be neutral or carry a net negative charge at a second pH, where the second pH is different from, and generally higher than, the first pH. The net charge of the polyelectrolyte may be determined via titration using a particle charge detector.

[019] The polyelectrolyte can be a polycationic polymer, such as a branched organic amine or a linear one, such as branched polyethylene imine (PEI). The term polycationic polymer refers to the typical charge of the polyelectrolyte and, as discussed below, the charge can be adjusted by adjusting the pH of the carrier medium.

[020] The branched PEI has a dissociation constant (pKa) of Petition 870250094090, dated 10 / 15 / 2025, pages 104 / 119 6 / 20 approximately 9. That is, up to a pH of approximately 9, branched PEI has a positive charge. At a pH greater than approximately 9, branched PEI has a neutral charge.

[021] Branched PEI may be supplied in an amount greater than approximately 0.01% (w / w) relative to the total weight of the composition. Without wishing to be limited by theory, in an amount less than 0.01% (w / w) branched PEI would not be expected to provide any functionality, i.e., pH responsiveness to the composition, in particular, it would not bind in sufficient quantities to the pigment particles.

[022] Branched PEI may be supplied in an amount less than approximately 10% (w / w) relative to the total weight of the composition. Branched PEI is advantageously supplied in an amount of about 0.05% (w / w) to about 2% (w / w) relative to the total weight of the composition, as from about 0.1% (w / w) to about 1% (w / w), as from about 0.1% (w / w) to about 0.5% (w / w). The amount of branched PEI may differ depending on the specific pigment in the composition or the amount of pigment in the concentration. Specifically, with respect to the specific pigment in the composition, the amount of branched PEI in the composition may be adjusted to match the net charge of the selected pigment particle.Since pigment particles each have different zeta potential curves and different net charges at a specific pH, this leads to the selection of an appropriate amount of branched PEI.

[023] The composition may comprise a plurality of polyelectrolytes. Each of the plurality of polyelectrolytes being adsorbed onto the surface of the pigment particle to form the pH-responsive pigment particle. Each or some of the plurality of polyelectrolytes may have different net charges, such as opposite net charges, at the first pH. Each or some of the plurality of polyelectrolytes may have different net charges, such as opposite net charges, at the second pH. Such a combination of a plurality of polyelectrolytes allows the net charge of Petition 870250094090, dated 10 / 15 / 2025, pages 105 / 119 7 / 20 pH-responsive pigment particles should be adaptable by adjusting the ratio of the respective polyelectrolytes. An example of a second polyelectrolyte having a net charge different from the net charge of PEI at the first pH is carboxymethyl cellulose, CMC.

[024] The composition may comprise a weight ratio of pigment to polyelectrolyte greater than about 1:1, such as greater than about 2:1, and ideally greater than about 3:1, such as about 5:1. The ratio of pigment to branched PEI may be greater than about 1:1, such as greater than about 2:1, and ideally greater than about 3:1, such as about 5:1.

[025] To ensure that pH-responsive pigment particles have a controlled and substantially known net surface charge, the composition may be provided with a pH control agent. For example, the composition may comprise an acid and / or base selected to ensure that the composition has a suitable pH. The experimental section below details the use of hydrochloric acid to provide the composition with a pH suitable for staining, i.e., fixing the pH-responsive pigment particles; however, many other acids may be suitable for adjusting the pH of the composition.

[026] The fiber coloring composition is non-film-forming. The term “non-film-forming” refers to pH-responsive pigment particles being present in a dispersion in the composition and remaining substantially separated when supplied to the fiber to be colored. The composition does not comprise a film-forming agent. The composition does not comprise a film-forming polymer. Typical film-forming polymers known in the fiber coloring field are vinyl pyrrolidone copolymers and vinyl acetate monomers, vinyl pyrrolidone homopolymers, for example, VP / VA copolymer (or PVP / VA copolymer), PVP. The composition does not comprise the film-forming agents listed above.

[027] To obtain a dispersion of pH-responsive pigment particles in the composition, the composition and specifically the pH-responsive pigment particles may be provided with a dispersant. The dispersant ensures that the particles Petition 870250094090, dated 10 / 15 / 2025, pp. 106 / 119 8 / 20 of pH-responsive pigments do not agglomerate in the composition and when supplied to the fiber to be colored. The dispersant can be, for example, a nonionic, anionic, cationic, or amphoteric surfactant. As revealed in the experimental section, the dispersant can be a nonionic surfactant. The dispersant is adsorbed onto the surface of the pH-responsive pigment particle. That is, the dispersant and the polyelectrolyte, such as branched PEI, are adsorbed onto the surface of the pigment particle.

[028] The dispersant may be present in the composition in an amount less than 5% (weight / weight) in relation to the total weight of the composition, ideally the dispersant is present in an amount less than 1% (weight / weight), such as less than 0.5% (weight / weight), such as less than 0.3% (weight / weight).

[029] The composition may comprise a wetting agent to aid the dispersion of pH-responsive pigment particles in the aqueous carrier medium. The wetting agent is adsorbed onto the surface of the pH-responsive pigment particles. When the wetting agent is present in the composition, the wetting agent, the chemical agent having a controllable modifiable net charge via pH adjustment such as the polyelectrolyte, and the dispersant are adsorbed onto the surface of each of the pigment particles. The wetting agent may be polyethylene glycol (PEG) such as PEG-200. The wetting agent can be supplied in an amount from about 0.2% (w / w) to about 10% (w / w), from about 1% (w / w) to about 5% (w / w), from about 1.5% (w / w) to about 4% (w / w), and from about 2% (w / w) to about 3% (w / w).

[030] The composition may comprise a pigment to wetting agent ratio of less than about 1:1, such as less than about 1:2, and ideally less than about 1:2.5, such as about 1:3. The composition may comprise a pigment to PEG ratio of less than about 1:1, such as less than about 1:2, and ideally less than about 1:2.5, such as about 1:3.

[031] As used in the present invention, the term pigment refers to any Petition 870250094090, dated 10 / 15 / 2025, pp. 107 / 119 9 / 20 a particulate colorant substance comprising or containing pigment material that colors fibers, such as keratin fibers. The pigment particles, at least before becoming pH responsive, are substantially insoluble and poorly dispersible in water. The particular pigment particle, or combination of pigment particles, is selected based on the desired color to be imparted to the fiber and any additional visual / appearance performance features also desired. The present composition is suitable, however, for use with various pigments, both organic and inorganic, combinations of organic pigments, combinations of inorganic pigments, or combinations of organic and inorganic pigments.

[032] Pigment particles can be chosen from known inorganic and organic pigments in the field of fiber coloring. The pigment particle can be an inorganic or organic pigment particle coated with an additional coating layer, i.e., the pigment is coated with an additional layer not related to pH responsiveness. The pigment particles can be in the form of a powder or a paste. The pigment can be a mineral pigment, an organic pigment, an elemental metal or a metal oxide, a lake pigment, an inorganic-organic composite pigment such as nacre, or a mixture thereof.

[033] Inorganic pigments are particularly ideal for the pigment particles of the present composition. Inorganic pigments generally require improved resistance to light (both visible and ultraviolet), time, and temperature. Inorganic pigments can be white pigments such as titanium dioxide or zinc oxide, colored pigments such as red iron oxide. The pigment particles can be selected from metal oxides, hydroxides and oxide hydrates, mixed-phase pigments, sulfur-containing silicates, metal sulfides, complex metal cyanides, metal sulfates, chromates and molybdates, alloys, and the elemental metals themselves. The pigment(s) can be selected from siliconized or stearate-coated inorganic pigments. The pigment(s) can be selected from the group consisting of titanium dioxide (Ci Petition 870250094090, dated 10 / 15 / 2025, pp. 108 / 119 10 / 20 77891), black iron oxide (Ci 77499), yellow iron oxide (Ci 77492), red and brown iron oxide (Ci 77491), siliconized iron oxide, manganese violet (Ci 77742), ultramarine (sodium aluminum sulfosilicates, Ci 77007, Pigment Blue 29), chromium oxide hydrate (Ci 77289), Prussian blue (ferric ferrocyanide, Ci 77510), carmine (cochineal), zinc sulfide, barium sulfate, zinc oxide, siliconized titanium dioxide, siliconized zinc sulfide, siliconized zinc oxide and mixtures thereof. The pigment(s) may be selected from the group consisting of iron oxide, titanium dioxide, mica, borosilicate and combinations thereof. The pigment may comprise an iron oxide pigment (Fe2C>3).

[034] The pigment can be an organic pigment. Organic pigments are organic compounds and have a variety of structures, compositions and therefore colors.Organic pigments may include nitroso, nitro, azo, xanthene, quinoline, anthraquinone, phthalocyanine, copper phthalocyanine, copper hexadecachlorophthalocyanine, 2-[(2-Methoxy-4-nitrophenyl)azo]-N-(2-methoxyphenyl)-3-oxobutyramide, metal complex, isoindolinone, isoindoline, quinacridone, perinone, perylene, diketopyrrolopyrrole, thioindigo, dioxazine, triphenylmethane, dimethylquinacridone and quinophthalone compounds, azo dyes, non-ionic azo dyes, anionic azo dyes, cationic azo dyes, complex-forming azo dyes, aza annulene dyes, aza analogs of diaryl methane dyes, aza annulene dyes, nitro dyes and their pigments. Carbonyl dyes and their pigments (e.g., anthraquinone dyes, indigo), sulfur dyes, fluorescence dyes, anthracene, or insoluble alkali or alkaline earth metal acid dyes. The organic pigment may be any known organic pigment.

[035] The pigment particle can assume a variety of shapes and forms depending on the specific pigment and whether it is coated or treated. The pH-responsive pigment particle has a substantially similar particle size and shape when compared to the pigment lacking any pH responsiveness. If the pigment particle is spherical, the pigment particle can have a diameter, such as a D50(vol.) diameter, of approximately 0.01 µm to several µm. A Petition 870250094090, dated 10 / 15 / 2025, pages 109 / 119 11 / 20 pigment particles typically have a D50(vol.) diameter of approximately 0.05 µm to 1 µm, such as from about 0.05 µm to about 0.5 µm. If the pigment particle is spherical, the pH-responsive pigment particle, that is, the pigment particle with at least the chemical agent having a controllable modifiable net charge via pH adjustment of the composition adsorbed on the surface of the pigment particle, may have a diameter of approximately 0.01 µm to several µm, such as from about 0.05 µm to about 1 µm.

[036] Different pigment particles can be combined to obtain improved visual appearance of colored fibers. For example, a combination of at least two different pigment materials to form a combined pigment mixture. The combined pigment mixture can provide improved reflective, refractive, and light transmission properties to the colored fiber.

[037] The zeta potential of the pigment particle can change depending on the pH of the carrier medium in which it is present. The pigment particle can have a zeta potential less than -10 mV from about pH 4 to about pH 8. The pigment particle can have a zeta potential from about 0 to about 40 mV from about pH 4 to about pH 9. The pigment particle can have a zeta potential of about 35 mV to about 0 mV from about pH 4 to about pH 9, as well as at about pH 8. The zeta potential of the pigment can be measured as described in the experimental section.

[038] The composition may comprise pigment particles in an amount from about 0.01% (weight / weight) to about 20% (weight / weight) relative to the total weight of the composition, as from about 0.1% (weight / weight) to about 5% (weight / weight).

[039] The carrier medium of the composition can be an aqueous carrier medium. The composition can be considered an aqueous composition comprising pH-responsive pigment particles. The composition may comprise the carrier medium in an amount from about 50% (w / w) to about 99% (w / w) relative to the total weight of the composition, as from about Petition 870250094090, dated 10 / 15 / 2025, pages 110 / 119 12 / 20% (weight / weight) to approximately 99% (weight / weight), as well as from approximately 93% (weight / weight) to approximately 98% (weight / weight) of half load. The half load may be water.

[040] The composition may be a liquid dispersion, a gel dispersion, a cream dispersion or any other form that is suitable for application to the fibers to be treated.

[041] The composition is a ready-to-use composition, the term “ready-to-use” refers to a composition that is suitable for direct application to the fibers to be treated. The composition is supplied in a form that is suitable for direct use and does not result from mixing, for example, several separate components in combination with application to the fibers to be treated.

[042] The composition may optionally include, or optionally exclude, one or more miscellaneous ingredients. Miscellaneous ingredients are ingredients that are compatible with the cosmetic compositions and do not impair or materially affect the fixation of pH-responsive pigment particles of the compositions. Non-limiting examples of miscellaneous ingredients include preservatives, fragrances, antioxidants, flavonoids, vitamins, botanical extracts, UV filtering agents, proteins, hydrolysates and / or protein isolates.

[043] The total quantity of one or more different ingredients, if present, will vary. Nevertheless, in various embodiments, the composition may comprise from about 0.001% (weight / weight) to about 10% (weight / weight) of one or more different ingredients, in relation to the total weight of the composition.

[044] To color the fibers, the composition can be applied to the fibers, such as keratin fibers, according to the following process: The composition is applied to the fibers; the composition can be applied by direct application via a brush, spraying, etc., or washed in, for example, with a shampoo comprising the present composition and... The mixture is left to act on the hair fibers for a period ranging from about 30 seconds to about 48 hours, preferably without rinsing. Petition 870250094090, dated 10 / 15 / 2025, pages 111 / 119 The 13 / 20 composition can optionally be dried, such as via blow drying.

[045] pH-responsive pigment particles are thus attracted to the fibers via electrostatic interaction and van der Waals forces and remain attached to the fibers.

[046] To remove the composition from the fibers, the following process can be used: an alkaline medium is applied to the fibers; if the fibers are hair fibers, the alkaline medium can be a shampoo having a pH greater than about 8; the alkaline medium alters the net surface charge of the pH-responsive pigment particles so that the pH-responsive pigment particles are electrostatically repelled by the fibers; the pH-modified pigment particles are subsequently detached from the fibers. The alkaline medium may additionally and advantageously comprise at least one surfactant known in the field. The at least one surfactant may be a nonionic, anionic, cationic, or amphoteric surfactant. The at least one surfactant may be, for example, sodium lauryl sulfate (SDS / SLS). The alkaline medium may comprise at least two surfactants, such as a nonionic surfactant and an anionic surfactant.

[047] The present composition is ideally what is known in the field as a “leave-in” composition, whereby a post-application rinsing step is not required to activate the color. As the pH-responsive pigment particles are attracted to the fibers via electrostatic interaction and the pH-responsive pigment particles provide an external coating to the fiber, the color is delivered to the fiber directly upon application of the composition.

[048] The composition can be applied to wet or dry fibers. Fibers, such as keratin fibers, can be washed before application. The composition can be applied to fibers at room temperature. EXPERIMENTAL SECTION EXPERIMENT 1: PREPARATION OF A COMPOSITION COMPRISING pH-RESPONSIVE PIGMENT PARTICLES Petition 870250094090, dated 10 / 15 / 2025, pp. 112 / 119 14 / 20

[049] To prepare the composition, 0.2 g of branched polyelectrolyte PEI was dissolved in 40 ml of water. Next, 0.3 g of pigment (PV23, hydrophobic violet pigment) was added and the solution was stirred for 2 minutes. 1 ml of PEG-200 was then added to act as a wetting agent and disperse the pigment in water, and the solution was stirred and then sonicated using a sonicator for 1 minute at 50% amplitude. 0.1 g of the nonionic surfactant CnEs (Ethylan® 1008, Nouryon) is subsequently added and then the pH is adjusted to 6.8 as hypophosphorous acid. The dispersion was sonicated again for 30 seconds at 50% amplitude. Following this initial sonication, 0.2 g of an amphiphilic polymer with sulfated polar heads (Tego® 656, Evonik Operations GmbH) was added. The pH was adjusted to 12 by adding sodium hydroxide, NaOH.The composition was sonicated again to allow the pH-responsive pigment particles to disperse and the polymers (PEI, PEG, Tego) to be adsorbed onto the surface of the pigment particles. EFFECT OF POLYMER AMOUNT ON PARTICLE SIZE

[050] To determine the resulting particle size in the composition. An experiment consisting of measuring the particle size by dynamic light scattering as a function of the total mass of PEI, Tego 656, and Ethylan 1008 was performed. The mass ratios between the three respective components were maintained. Several compositions were made with a total mass of PEI, Tego 656, Ethylan 1008 of 0.1 g, 0.3 g, 0.5 g, 0.7 g, and 1 g. The particle size was measured by DLS at a pH of approximately 7. The dynamic light scattering measurement was performed with a submicron particle analyzer (Beckman Coulter, N4 Plus). The results are shown in Figure 1.

[051] As can be seen in Figure 1, as the total mass of polymers increases, the pigment particle size decreases. That is, an increase in the amount of polymer results in a decrease in particle size. A smaller particle size increases colloidal stability and results in coloration. Petition 870250094090, dated 10 / 15 / 2025, pp. 113 / 119 15 / 20 improved and more effective as the specific surface area of ​​the particles is increased relative to the total amount of particles in the composition. Visual inspection confirmed the colloidal stability of the compositions having smaller particle sizes. The composition with a total polymer mass of 0.1 g at a pH of 12 showed clear sedimentation of the particles due to the larger particle size. The composition comprising a total polymer mass of 0.5 g did not settle and remained stable in a pH range of 4 to 12. Determination of the isoelectric point of pH-responsive pigment particles.

[052] The zeta potential of the composition comprising 0.5 g of the total polymer mass as a function of pH was measured by a ZetaPALS system (Brookhaven Instruments, USA). An electrode cleaned with ethanol and water is placed in a receptacle comprising 1.4 ml of the composition, allowing for the measurement of electrophoretic mobility. The results are shown in Figure 2.

[053] According to Figure 2, it can be seen that at acidic pH, the zero potential was around +35 mV, which was high enough to have a stable colloidal dispersion and good fixation on negatively charged fibers. EXPERIMENT 2: HAIR COLORING WITH A COMPOSITION COMPRISING TEI, TEGO, AND CMC FOR IMPROVED BLEACHING

[054] To provide a composition having a decreased (more negative) zeta potential at higher pH, the polyelectrolyte carboxymethyl cellulose (CMC) was supplied to the composition described in experiment 1. The composition comprised 0.2 g of PEI, 0.2 g of Tego, and the remaining components of the composition were unchanged. CMC was supplied in varying amounts, and the zeta potential as a function of pH was determined for each of the compositions comprising CMC. The results are shown in Figure 3.

[055] As can be seen in Figure 3, the provision of the additional polyelectrolyte CMC decreases the zeta potential of the pH-responsive pigment particles when compared with the results shown in Figure 2. At acidic pH, the zeta potential Petition 870250094090, dated 10 / 15 / 2025, pp. 114 / 119 At pH 16 / 20, the zeta potential was positive and high, around +35 mV. At basic pH, the zeta potential reached values ​​approaching -50 mV. With a composition comprising CMC, which decreases the zeta potential at higher pH, improved decolorization can be achieved when the negative charge of the pH-responsive pigment particle is desorbed and repelled from the negatively charged fiber surface.

[056] The composition according to experiment 1 with 0.2 g of PEI, 0.2 g of Tego and 0.2 g of CMC were diluted five times with water. At a pH of 4.88, no sedimentation occurred, meaning the dispersion remained stable. The diluted composition was applied to blond hair. The hair exhibited a vibrant color and was firm and resistant to mechanical abrasion.

[057] The hair colored with the diluted composition was subsequently bleached. The hair was bleached at a pH of 12.21 with 1% SDS and 1% Ethylan 1008. The bleaching was effective and the pH-responsive pigment particles were removed from the hair. During the hair bleaching process, the hair was rubbed to provide some mechanical abrasion. EXPERIMENT 3: ALTERNATIVE COLOR COMPOSITION

[058] A composition not comprising the amphiphilic polymer (Tego 656) nor the additional polyelectrolyte (CMC) was prepared.

[059] The composition comprised pigment, PEI, a dispersant (non-ionic surfactant Ethylan® 1008, Nouryon), a wetting agent (PEG-200) and water as detailed in the following table. TABLE 1: Component Quantity Pigment 150 mg Dispersant (Ethylan 1008) 50 mg Wetting agent (PEG-200) 0.5 ml Water 20 ml Petition 870250094090, dated 10 / 15 / 2025, pages 115 / 119 17 / 20 PEI (Concentration: 5% w / w) 0.6 ml

[060] The composition was prepared as follows: 150 mg of pigment were added to a 30 ml vial. 0.6 ml of PEI solution was added to the pigment. 50 mg of dispersant were added to the mixture. 0.5 ml of wetting agent was added to the mixture. 20 ml of water were added to the mixture to form an aqueous dispersion of pH-responsive pigment particles, forming the composition comprising pH-responsive pigment particles. The dispersion was subsequently sonicated for 30 seconds to ensure particle separation in the dispersion. The pH of the dispersion was reduced to approximately 5.5 via the addition of hydrochloric acid. The particle size and zeta potential of the composition comprising the pH-responsive pigment particles were determined via DLS and the ZetaPALS system as described for experiment 1.

[061] The composition was subsequently applied to strands of hair and left for approximately 10 minutes. The hair samples were inspected. The colored hair showed high intensity and uniformity of color. The hair appeared very similar to a control hair strand that had not been colored. The colored hair was immersed in water for 30 min to determine colorfastness. The hair was subsequently wiped with paper towels. The appearance of the colored hair after immersion in water was similar to its appearance before. Additionally, there was little or no color present on the paper towel, indicating that the pH-responsive pigment particles had adhered satisfactorily to the hair fibers. EXPERIMENT 4: APPLICATION AND REMOVAL OF COLOR COMPOSITION ON COTTON FIBERS

[062] To determine the effectiveness of fiber coloring in addition to human hair, the composition from experiment 2 was applied to natural cotton fibers. Natural cotton fibers have a negative, net, natural surface charge. The composition according to experiment 2 was diluted by a factor of 5 with water. Petition 870250094090, dated 10 / 15 / 2025, pp. 116 / 119 18 / 20 to ensure the colloidal stability of the composition. A sample of cotton fabric was immersed in the diluted composition for 5 minutes. The pH of the immersion composition was 6.94 (i.e., approximately 7). Intense and homogeneous coloration of the cotton fabric sample was observed.

[063] To determine the effectiveness of decolorization, the cotton fabric sample was cut into five pieces and each piece was immersed in a different solution having a known pH for 5 minutes at room temperature (except for 12.01, as described below). The solutions were stirred during the 5 minutes of decolorization. The pH values ​​of the different solutions were 2.9, 8.1, 12.01, 12.07, and 12.17. The solution having a pH of 12.01 was heated to 60 °C to determine the effect of elevated temperature on decolorization. The solution having a pH of 12.07 was placed in an ultrasonic bath at room temperature.

[064] As expected, the fabric scraps in the pH 2.9 and 8.1 solutions did not exhibit discoloration. The pH-responsive pigment particles remained firmly attached to the cotton fibers. Discoloration occurred for the solutions at pH 12.01, 12.07, and 12.17. No increased discoloration occurred for the fabric scrap subjected to elevated temperature. The fabric scrap subjected to the ultrasonic bath exhibited slightly improved discoloration. To evaluate this effect, the above experiment was repeated with a larger fabric scrap, and ultrasonic agitation was performed locally on specific areas of the fabric. The results showed that the local application of ultrasonic agitation to specific areas of the fabric resulted in improved discoloration in those areas.

[065] Initial cotton, cotton colored at pH 6.94 for 5 minutes with agitation, and bleached cotton at room temperature in an ultrasonic bath were analyzed using a portable spectrometer to determine the color of the textile article in the CIE Lab coordinate system. The results table below shows the different L*, a*, and b* values ​​of the original, colored, and bleached cotton. Three quantities characterize the colors: the lightness L* derives from the surface luminance, the parameter a* represents the value on a geometric axis from green to Petition 870250094090, dated 10 / 15 / 2025, pp. 117 / 119 19 / 20 red and the parameter b* represents the value on a geometric axis from blue to yellow. Two measurements were taken at different locations on the cotton samples. TABLE 2: Sample L* a* b* Initial uncolored cotton 95.53 -0.22 -1.31 95.58 -0.18 -1.76 Colored cotton 51.50 19.24 -30.34 51.52 19.34 -30.57 Bleached cotton 79.09 11.58 -20.11 79.13 11.73 -20.60 EXPERIMENT 5: COLORING WOOL FIBERS WITH THE COMPOSITION

[066] A composition was prepared according to Experiment 3. The pH of the pH-responsive pigment particle dispersion was adjusted to pH 6.4 in preparation for the application step. The composition was applied to wool and allowed to color the wool for 10 minutes. The pigment color was bright and intense on the wool. After coloring, the colored wool sample was rubbed with paper towel. There was slight color bleeding onto the paper towel during rubbing. The colored wool sample was rinsed with water. There was no significant difference in color intensity after rinsing the wool with water. Experiment 5 showed that the composition is suitable for coloring wool fibers.

[067] Although the present invention has been described above with reference to specific embodiments, it is not intended to be limited to the specific form set forth in this document. Instead, the invention is limited only by the appended claims.

[068] In the claims, the term “comprising / comprising” does not exclude the Petition 870250094090, dated 10 / 15 / 2025, pp. 118 / 119 20 / 20 presence of other elements or steps. Additionally, although individual features may be included in different claims, these may possibly be advantageously combined, and inclusion in different claims does not suggest that a combination of features is not feasible and / or advantageous. Furthermore, singular references do not exclude a plural. The terms “a”, “an”, “first”, “second”, etc. do not preclude a plurality. Reference signs in the claims are provided merely as a clarifying example and should not be interpreted as limiting, in any way, the scope of the claims. Petition 870250094090, dated 10 / 15 / 2025, page 119 / 119

Claims

1 / 4 CLAIMS 1. Non-film-forming composition for coloring fibers, the composition being characterized by comprising: a dispersion of pigment particles in a carrier medium and a polyelectrolyte having a controllable net charge from a positive net value at a first pH and a neutral or negative net charge at a second different pH, such that the net charge of the polyelectrolyte has a controllable net charge via adjustment of the pH of the carrier medium, wherein the polyelectrolyte is adsorbed onto the surface of the dispersed pigment particles forming pH-responsive pigment particles and wherein the net electrical charge of the pH-responsive pigment particles is adjustable via adjustment of the pH of the carrier medium.

2. Non-film-forming composition according to claim 1, characterized in that the pH-responsive pigment particles adsorb onto the fiber surface at the first pH and the pH-responsive pigment particles desorb from the fiber surface at the second pH.

3. Non-film-forming composition according to claim 1 or 2, characterized in that the composition is for coloring keratin fibers.

4. Non-film-forming composition according to any one of claims 1 to 3, characterized in that the polyelectrolyte is a branched or linear organic amine.

5. Non-film-forming composition according to any one of claims 1 to 4, characterized in that the polyelectrolyte is linear or branched polyethylene imine.

6. Non-film-forming composition according to any one of claims 1 to 5, characterized in that the first pH is substantially lower than the second pH.

7. Non-film-forming composition, according to any one of claims 1 to 6, characterized in that the first pH is less than about 8, Petition 870250094090, dated 10 / 15 / 2025, page 92 / 119 2 / 4, as less than about 7, such that the polyelectrolyte has a net positive charge at a pH less than about 8, as less than about 7.

8. Non-film-forming composition according to any one of claims 1 to 7, characterized in that the pH-responsive pigment particles have a net positive charge at the first pH.

9. Non-film-forming composition according to any one of claims 1 to 8, characterized in that the second pH is greater than about 7, such as greater than about 8, such that the polyelectrolyte has a net neutral or negative charge at a pH greater than about 7, such as greater than about 8.

10. Non-film-forming composition according to any one of claims 1 to 9, characterized in that the pH-responsive pigment particles have a net neutral or negative charge at the second pH.

11. Non-film-forming composition, according to any one of claims 1 to 10, characterized in that the pH-responsive particles have a net electrical charge opposite to that of the fibers to be colored.

12. Non-film-forming composition, according to any one of claims 1 to 11, characterized in that the polyelectrolyte is a first polyelectrolyte and in that the composition comprises a second polyelectrolyte, wherein both the first and second polyelectrolytes are adsorbed onto the surface of the dispersed pigment particles and in that the second polyelectrolyte has a different net charge with respect to the first polyelectrolyte at the first pH and optionally a different net charge with respect to the first polyelectrolyte at the second pH, such that the net charge of the pH-responsive pigment particle is adaptable via adjustment of the ratio of the first polyelectrolyte to the second polyelectrolyte.

13. Non-film-forming composition according to any one of claims 1 to 12, characterized in that the pigment particles are organic or inorganic pigment particles.

14. Non-film-forming composition, according to any of claims 1 to 13, characterized in that the composition comprises a dispersant, such as a non-ionic dispersant, adsorbed onto the pigment particles.

15. Non-film-forming composition, according to any one of claims 1 to 14, characterized in that the composition comprises a wetting agent, such as PEG, adsorbed onto the pigment particles.

16. Non-film-forming composition according to any one of claims 1 to 15, characterized in that the composition comprises at least 0.1% (w / w) of polyelectrolyte.

17. Non-film-forming composition according to any one of claims 1 to 16, the composition being characterized by comprising less than about 10% (weight / weight) of polyelectrolyte.

18. Non-film-forming composition, according to any one of claims 1 to 17, the composition being characterized by comprising a ratio of pigment particles in the composition to polyelectrolyte in a weight ratio greater than about 1:1, as greater than about 2:1, as about 5:

1.

19. Process for treating fibers, such as keratin fibers, the process being characterized by comprising: - providing a composition, the composition comprising: a dispersion of pigment particles in a carrier medium and a polyelectrolyte having a controllable net charge from a positive net value at a first pH and a neutral or negative net charge at a second different pH, such that the net charge of the polyelectrolyte has a controllable net charge via adjustment of the pH of the carrier medium, wherein the polyelectrolyte is adsorbed onto the surface of each of the dispersed pigment particles forming pH-responsive pigment particles and wherein the net electrical charge of the pH-responsive pigment particles is adjustable via adjustment of the pH of the carrier medium; and - applying the composition to the fibers to be treated, wherein the pH of the composition is selected so that the total net charge of the particles of Petition 870250094090, dated 10 / 15 / 2025, p.94 / 119 4 / 4 pH-responsive pigments are opposite to the net surface charge of the fibers being treated, thereby coloring the fibers.

20. Process according to claim 19, characterized in that the process comprises the steps of: - providing a second composition having a pH such that the total net charge of the pH-responsive pigment particles is opposite to the charge of the pH-responsive pigment particle upon application to the fiber and thereby - removing the pH-responsive pigment particles from the fibers, thereby decolorizing the fibers.

21. Process, according to claim 19 or 20, characterized in that the fibers are human hair.

22. Process, according to any one of claims 19 to 21, characterized in that the first composition is provided at a pH substantially lower than 7.

23. Process, according to any one of claims 20 to 22, characterized in that the second composition is provided at a pH substantially higher than 7, such as about 8. Petition 870250094090, dated 10 / 15 / 2025, pp. 95 / 119

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