Pigment ink dispersion, tattooing ink comprising pigment ink dispersion and methods of making same

Abstract

Disclosed is a pigment dispersion comprising: a pigment selected from the group consisting of TiCh (CI 77891), pigment blue 15 (CI 74160), carbon black (CI 77266), pigment orange 64 (CI 12760), pigment red 202 (CI 73907), pigment red 254 (CI 56110), pigment yellow 151 (CI 13980), pigment yellow 180 (CI 21290), pigment blue 16 (CI 74100), pigment blue 60 (CI 69800), pigment green 36 (CI 74265), pigment green 7 (CI 74260), and any combination thereof; a solvent, such as a hamamelis virginiana extract; and at least one additive, such as an alkyl glycoside, and having a low impurity content. The invention also discloses a tattoo ink containing the pigment dispersion and a method for preparing the pigment dispersion.

Description

[0001] This application is a divisional application of International Application No. PCT / US2023 / 062652, filed on February 15, 2023, Chinese National Application No. 202380034424.7, entitled “Pigment Ink Dispersion, Tattoo Ink Containing the Pigment Ink Dispersion and Method for Preparing the Same”. Technical Field

[0002] This disclosure relates to a novel pigment ink dispersion for tattoo inks with minimal impurities and a method for preparing the same. Background Technology

[0003] In 2000, the Scientific Committee on Cosmetic Products and Non-Food Products issued an opinion on the safety of tattoos. The committee recommended systematic measures to collect chemical and toxicological information for comprehensive risk assessment. (Blass Rico, AM, “EU Actions to Ensure the Safety of Tattoos and the Protection of Consumers,” Serup J, Kluger N, Bäumler W (ed.): Tattooed Skin and Health, Curr ProblDermatol. Basel, Karger, 2015, Vol. 48, pp. 206-209 (DOI: 10.1159 / 000369229)). The European Commission (EC) established a common-sense basis for the safety of tattoos and body piercings, including the collection and assessment of information on chemicals in consumer products and articles that consumers come into contact with, and the associated health risks. The report resulting from this work summarizes the conclusions and recommendations of regulatory actions in the EU regarding the safety of tattoos, body piercings, and related practices.

[0004] The European Commission's 2008 resolution (ResAP (2008)) laid the foundation for the safety of tattoo products, including safety requirements and standards for tattoo products and permanent cosmetics, to improve consumer health protection. Tattoo products are injected into the skin and may pose a risk to human health due to possible microbial contamination in the product and / or contamination by the presence of harmful substances. (See Verdier, C., “Surveillance of Tattoo-Related Adverse Events by the EU RAPEX System and by National Monitoring,” Serup J, Kluger N, Bäumler W (eds.): Tattooed Skin and Health. Curr Probl Dermatol. Basel, Karger, 2015, Vol. 48, pp. 210-217 (DOI: 10.1159 / 000369230).)

[0005] Tattoos can cause a wide range of clinical problems. Mild adverse reactions, especially sun sensitivity, are common, occurring in about 20% of cases. Medical complications can also occur, such as allergic reactions to tattoo ink, particularly to red tattoos, but also to blue and green tattoos. Tattoo allergies and local reactions present with diverse clinical manifestations, including plaque-like, hyperkeratotic, ulcerative necrosis, lymphopathic, neurosensory, and scar patterns. Reactions to black tattoos are papulonodular and non-allergic, and are associated with the aggregation of nanoparticle carbon black. Tattoo complications include effects on general health and psychosocial complications. Tattoos can also lead to bacterial contamination and infection, especially with Staphylococcus aureus, and in some cases, resistance to certain antibiotics.

[0006] Tattooing involves a single, large-dose injection applied to a specific area, the dosage of which depends on the size of the tattoo. Tattoo ink contains soluble components, which, it should be understood, distribute, metabolize, and be eliminated from the body over several days. However, the pigment particles remain permanently in the skin to provide the desired color. The pigment in the skin slowly fades over time, releasing trace amounts of chemicals and metabolites, which can actually cause adverse reactions such as allergies. Serup, J. et al., “Tattoo Complaints and Complications: Diagnosis and Clinical Spectrum,” Serup J, Kluger N, Bäumler W (eds.): Tattooed Skin and Health. Curr ProblDermatol. Basel, Karger, 2015, Vol. 48, pp. 48–60 (DOI: 10.1159 / 000369645). This release is triggered by enzymatic and cellular processes in the tissue, unlike the harsh chemical degradation in a laboratory setting accompanied by the formation of chemical cleavage products (an artificial and unrealistic scenario). Ibid. The pigment injected into the tattoo partially escapes through the lymphatic system and deposits in the regional lymph nodes. Ibid. The lymph nodes are visibly stained along with the skin. Ibid. However, unknown amounts of pigment nanoparticles may reach the bloodstream and theoretically cause harm somewhere in the body. Ibid.

[0007] According to literature, many tattoo inks (refer to registration data) contain carcinogenic, mutagenic, and reproductive toxic substances. Ibid. However, concerns that tattoos may induce skin cancer (including malignant melanoma) have not been confirmed by medical literature and remain only hypothetical. Ibid.

[0008] New inks and pigments are needed to address the potential health and safety issues associated with tattooing. Summary of the Invention

[0009] This invention discloses a pigment dispersion comprising: a pigment selected from the following: TiO2 (CI 77891), Pigment Blue 15 (CI 74160), Carbon Black (CI 77266), Pigment Orange 64 (CI 12760), Pigment Red 202 (CI 73907), Pigment Red 254 (CI 56110), Pigment Yellow 151 (CI 13980), Pigment Yellow 180 (CI 21290), Pigment Blue 16 (CI 74100), Pigment Blue 60 (CI 69800), Pigment Green 36 (CI 74265), Pigment Green 7 (CI 74260), or any combination thereof; one or more solvents; and one or more additives. The pigment may be selected from Pigment Blue 16, Pigment Blue 60, Pigment Green 36, Pigment Green 7, or any combination thereof. The one or more solvents may be selected from North American witch hazel (… Hamamelis Virginiana Extracts, ethanol, water, or any combination thereof. The one or more solvents may be witch hazel (from North America). Hamamelis Virginiana Extract. The one or more additives are selected from: defoamers, dispersants, binders, humectants, wetting agents, and any combination thereof. The pigment dispersion may contain pigments, optionally from about 30% to about 60% by weight of the total weight of the pigment dispersion; witch hazel extract; ethanol; dimethicone; ammonium acrylate copolymer; glycerin; polyethylene glycol; alkyl polysaccharide; and water.

[0010] The pigment dispersion may contain less than about 5 ppm of the free aromatic amines listed in Table 4. The pigment dispersion may contain less than about 0.5 ppm of mercury, organometallic tin, antimony, arsenic, cadmium, chromium (Cr(VI)), or any combination thereof; less than about 0.7 ppm of lead; less than about 5 ppm of nickel; less than about 500 ppm of barium; less than about 250 ppm of copper; less than about 2 ppm of selenium; less than about 2000 ppm of zinc; and / or less than 0.005 ppm of benzo[a]pyrene. The pigment dispersion may contain less than about 0.5 ppm of one or more polyaromatic hydrocarbons listed in Table 3. The particle size range of the pigment dispersion may be from about 150 nm to about 15 μm, and / or the particle size distribution D90 of the pigment dispersion may be less than about 6 μm or less than about 5 μm.

[0011] This invention discloses a tattoo ink formulation comprising a pigment dispersion; at least one solvent; and at least one additive. The pigment dispersion constitutes less than about 95% by weight of the tattoo ink formulation. The tattoo ink formulation may contain: about 1% to about 95% by weight of the pigment dispersion; about 1% to about 50% by weight of witch hazel extract; and about 1% to about 50% by weight of water; and optionally less than about 5% by weight of impurities. The tattoo ink formulation may contain: less than or equal to about 0.5 ppm of total polycyclic aromatic hydrocarbons; less than or equal to about 10 ppm of benzo[a]pyrene (BaP); less than or equal to about 10 ppm of dibenzo[a,h]anthracene (DBA); less than or equal to about 3 ppm of arsenic; less than or equal to about 1 ppm of mercury; and / or less than or equal to about 10 ppm of lead.

[0012] The present invention also discloses a method for preparing a pigment dispersion. The method includes mixing a pigment, one or more solvents, and one or more additives at a speed of about 1,000 ft / min to about 20,000 ft / min for about 30 minutes to about 4 hours using a high-shear mixer. The present invention discloses another method for preparing a pigment dispersion, the method comprising: combining at least one solvent selected from witch hazel extract, ethanol, water, or any combination thereof; dimethicone; glycerol; a dispersant; and one or more additives to prepare a solution; mixing the solution to prepare a homogeneous mixture; and mixing in a high-shear mixer at about 2000 RPM to about 4000 RPM and at a temperature of about 68°F to about 110°F for about 1 hour to about 4 hours to prepare a homogeneous pigment dispersion. The present invention also discloses a method for preparing a pigment dispersion using powder induction, comprising mixing a homogeneous mixture in an online high-shear mixer at a temperature of about 3000 RPM to about 4000 RPM and about 68°F to about 110°F for about 1 hour to about 4 hours, while adding pigment to the homogeneous mixture via a powder induction system including a vacuum pump, wherein the powder induction system is coupled to the online high-shear mixer to prepare a homogeneous pigment dispersion. Attached Figure Description

[0013] Figure 1 This is a flowchart showing the process of mixing different ingredients into a base pigment and formulating the base pigment into tattoo ink.

[0014] Figure 2 It is a color reflectance curve of a pigment dispersion containing Pigment Black 7.

[0015] Figure 3 It is a color reflectance curve of a pigment dispersion containing Pigment Blue 15.

[0016] Figure 4It is a color reflectance curve of a pigment dispersion containing Pigment Orange 64.

[0017] Figure 5 It is a color reflectance curve of a pigment dispersion containing Pigment Red 202.

[0018] Figure 6 It is a color reflectance curve of a pigment dispersion containing Pigment Red 254.

[0019] Figure 7 It is a color reflectance curve of a pigment dispersion containing Pigment Yellow 151.

[0020] Figure 8 It is a color reflectance curve of a pigment dispersion containing Pigment Yellow 180.

[0021] Figure 9 It is a color reflectance curve of a pigment dispersion containing pigment white 6.

[0022] Figure 10 The color reflectance curve of a pigment dispersion containing Pigment Blue 60.

[0023] Figure 11 It is a color reflectance curve of a pigment dispersion containing Pigment Blue 16.

[0024] Figure 12 It is a color reflectance curve of a pigment dispersion containing pigment green 36.

[0025] Figure 13 It is a color reflectance curve of a pigment dispersion containing pigment green 7. Detailed Implementation

[0026] The pigment dispersions disclosed herein comprise pigments, one or more additives, and one or more solvents. The one or more additives impart desired properties to the pigment dispersions, while the solvents dilute the pigment dispersions. Figure 1 The processing steps for producing tattoo ink for human use are shown. The pigment dispersion may comprise at least one pigment, at least one solvent, and at least one additive. The additive may be selected from: wetting agents, dispersants, humectants, defoamers, and any combination thereof. The solvent and additive may be any solvent, wetting agent, dispersant, humectant, and defoamer known in the art for processing tattoo ink.

[0027] Pigment dispersions may contain pigments, at least one solvent, one or more additives, and defoamers. The solvent may be selected from witch hazel extract, ethanol, water, or any combination thereof. The solvent may be witch hazel extract, ethanol, and water. Witch hazel extract is also known as witch hazel extract. Witch hazel extract can be added to soothe the skin and reduce inflammation, and may have antibacterial properties. The witch hazel extract used in this article may be a standard USP grade witch hazel extract containing 14% ethanol.

[0028] Wetting agents, also known as surfactants, can be any substance that reduces the surface tension of a solvent or mixture, thereby allowing the formation of a pigment dispersion. Common wetting agents include ionic surfactants (such as sodium dodecyl sulfate) and nonionic surfactants (such as alkylphenol ethoxylates and alkyl polyglycosides). Wetting agents can be selected from fatty acids, sodium dodecyl sulfate, quaternary ammonium salts, fatty acid alkoxylates, alkyl polyglycosides, ethoxylated fatty alcohols, and any combination thereof. Wetting agents can be alkyl polyglycosides. Alkyl polyglycosides can be selected from: D-glucopyranose, oligomers, decyl octyl glycosides; D-glucopyranose, oligomers, C10-16-alkyl glycosides; and any combination thereof.

[0029] Defoamers can be silicone-based fluids or emulsions, such as, but not limited to, dimethicone, or any other defoamers known in the art for use in tattoo pigments and inks to prevent the formation of bubbles and foam in the ink.

[0030] Dispersants, also known as stabilizers, can be any polymer known in the art that stabilizes and disperses pigment particles through electrostatic and / or steric interactions. Dispersants can be polyphosphate polymers, polyacrylates, acrylic copolymers, polyurethane polymers, polyethylene glycol (PEG) polymers, polyvinylpyrrolidone (PVP) polymers, ammonium acrylate copolymers, alkyl polysaccharides, or any combination thereof. Pigment dispersions may contain ammonium acrylate copolymers that adjust the viscosity of the pigment and make the tattoo ink easier to "insert" into the skin by giving it a "silkier" texture.

[0031] Pigment dispersions may contain humectants. Humectants prevent ink drying and improve the redispersibility of colorants. Humectants are also added to help moisturize the skin, preventing moisture loss and dryness of newly formed skin. Humectants can be glycerin, propylene glycol, hyaluronic acid, salicylic acid, sorbitol, and any combination thereof.

[0032] The pigment dispersion may contain one or more of the following: fatty acid alkoxylates (e.g., about 1% to about 10% by weight), ethoxylated fatty alcohols (e.g., about 1% to about 10% by weight), fatty acids (e.g., about 1% to about 10% by weight), sodium dodecyl sulfate (e.g., about 1% to about 10% by weight), quaternary ammonium salts (e.g., about 1% to about 10% by weight), disodium decanol ether-6 sulfosuccinate (e.g., about 1% to about 10% by weight), modified acrylic polymers (e.g., about 1% to about 20% by weight), sorbitol (e.g., about 1% to about 10% by weight), benzyl alcohol (e.g., about 1% to about 10% by weight). Polyethylene glycol (PEG) polymers (e.g., from about 1 wt% to about 20 wt%), polysorbate 80 (e.g., from about 1 wt% to about 20 wt%), polysorbate 20 (e.g., from about 1 wt% to about 20 wt%), polyvinylpyrrolidone (PVP) polymers (e.g., from about 1 wt% to about 20 wt%), vinyl acetate polymers (e.g., from about 1 wt% to about 20 wt%), polyethylene glycol-polypropylene glycol polymers (e.g., from about 1 wt% to about 20 wt%), styrene / acrylic copolymers (e.g., from about 1 wt% to about 20 wt%), PVP / vinyl acetate copolymers (e.g., from about 1 wt% to about 20 wt.%); and any combination thereof.

[0033] Pigments are insoluble colorants, natural or synthetic, used to impart visual properties to various products. The pigments used in this article may be Pigment Black 7, Pigment Blue 15, Pigment Blue 16, Pigment Blue 60, Pigment Blue 79, Pigment Green 7, Pigment Green 36, Pigment Red 101, Pigment Red 170, Pigment Red 185, Pigment Red 238, Pigment Red 202, Pigment Red 254, Pigment Red 266, Pigment Orange 36, Pigment Orange 64, Pigment Orange 73, Pigment Violet 55, Pigment Yellow 42, Pigment Yellow 138, Pigment Yellow 151, Pigment Yellow 155, Pigment Yellow 180, Pigment White 6, or any combination thereof. The pigments used in this article may be Acid Blue 9 lake, Acid Yellow 23 lake, Acid Red 18 lake, or any combination thereof. The pigments used in the pigment dispersions described herein may be in powder form and selected from TiO2 (CI77891), Pigment Blue 15 (CI 74160), Pigment Blue 16 (CI 74100), Pigment Blue 60 (CI 69800), Pigment Green 36 (CI74265), Pigment Green 7 (CI 74260), Carbon Black (CI 77266), Pigment Orange 64 (CI 12760), Pigment Red 202 (CI73907), Pigment Red 254 (CI 56110), Pigment Yellow 151 (CI 13980), Pigment Yellow 180 (CI 21290), or any combination thereof.

[0034] Black pigments can include carbon black, which is composed of elemental carbon in quasicrystalline form. Carbon black is also known as Pigment Black 7, furnace black, or high-purity furnace black, CI 77266, with CAS registration number 1333-86-4. Blue pigments can include Pigment Blue 16 (CI 74100), Pigment Blue 60 (CI 69800), and / or Pigment Blue 15 (also known as Pigment Blue 15:3, CI 74160, and Blue Phthalocyanine, CAS registration number 147-14-8). White pigments can include TiO2, Pigment White 6, CI 77891, with CAS registration number 13463-67-7. Orange pigments can include Pigment Orange 64 (CI 12760), with CAS registration number 72102-84-2. Magenta pigments may include Pigment Red 202 (CI 73907), with CAS registration number 3089-17-6. Red pigments may include Pigment Red 254 (CI 56110), with CAS registration number 84632-65-5. Yellow pigments may include one of Pigment Yellow 151 (CI 13980) and Pigment Yellow 180 (CI 21290), with CAS registration numbers 31837-42-0 and 77804-81-0, respectively. Green pigments may include Pigment Green 36 (CI 74265), Pigment Green 7 (CI 74260), or combinations thereof. Green pigments may also include mixtures or combinations of Pigment Yellow 151 (CI 13980) and Pigment Blue 16 (CI 74100) and Pigment Blue 60 (CI 69800). Pigment Green 36 has the following chemical structure: .

[0035] Pigment Green 7 has the following chemical structure: .

[0036] Pigment Blue 16 has the following chemical structure: .

[0037] Pigment Blue 60 has the following chemical structure: .

[0038] To deliver pigments to the desired substrate (skin), carrier molecules must be used to transport the pigments in liquid form. The smallest basic unit of a pigment is called a primary particle. During the manufacturing process, primary particles fuse together through covalent bonds to form aggregates. These aggregates further self-assemble to form larger structures called agglomerates. By definition, pigments are insoluble in the carrier system used and must be dispersed using both mechanical forces and additives. The dispersion process involves three steps that occur approximately simultaneously. To distribute the pigment throughout the carrier system, the entire surface area of ​​the pigment must be exposed to the carrier solvent. This step is called “wetting” the pigment. Because pigments are insoluble in the carrier solvent system, a wetting agent is required. A wetting agent is any additive that reduces the surface tension of the liquid dispersion medium to allow for solid-air interface displacement. Most wetting agents are low molecular weight amphiphilic substances.

[0039] To form a uniformly distributed dispersion, the pigment must be broken down into aggregated particles. This step is called "deagglomeration." The main forces that must be overcome during deagglomeration are van der Waals forces and electrostatic interactions between the pigment aggregates. This is primarily achieved by introducing mechanical forces (impact and shear forces). Special additives may also help reduce the energy required to separate the aggregates. In most cases, the aggregates remain intact during dispersion and determine the visual properties of the pigment dispersion.

[0040] Once dispersed, pigment aggregates exist in an unstable state. Dispersants must be used to stabilize the dispersed pigment particles. Dispersants stabilize separated pigment particles through two main methods: electrostatic stabilization and steric stabilization. Electrostatic stabilization involves surrounding the ionic pigment with a polyionic dispersant. For the dispersion of inorganic pigments, electrostatic stabilization is the most important factor. Steric stabilization involves using dispersants with large-volume functional groups that prevent the dispersed pigment particles from coming into close contact with each other. Most dispersants are oligomers or polymers and can generally stabilize dispersions using both methods.

[0041] Once the pigment is dispersed and stabilized, it is considered ink and ready for use in tattooing. For ease of documentation, we define a base pigment composition tattoo ink as any ink dispersion containing only one pigment. While tattoos can be produced using a single base pigment, tattoo artists often dilute or mix several base pigments to achieve the desired visual properties in tattoo ink. To accommodate this, most tattoo ink manufacturers sell tattoo inks in the form of premixed ink dispersions containing several colorants.

[0042] The pigment dispersion or white pigment dispersion may comprise TiO2 (CI 77891), one or more solvents, and one or more additives. The solvent may be witch hazel extract, ethanol, water, or any combination thereof. The additive may be selected from: defoamers (e.g., dimethicone), dispersants (e.g., ammonium acrylate copolymers), binders, humectants (e.g., glycerin), wetting agents (e.g., alkyl polysaccharides), and any combination thereof. The white pigment dispersion may comprise TiO2 (CI 77891), one or more solvents, defoamers (e.g., dimethicone), dispersants (e.g., ammonium acrylate copolymers), binders, humectants (e.g., glycerin), and one or more additives. The white pigment dispersion may comprise TiO2 (CI 77891), witch hazel extract, ethanol, water, dimethicone, ammonium acrylate copolymers, glycerin, polyethylene glycol, one or more alkyl polysaccharides, and optionally one or more additional additives. White pigment dispersions may contain TiO2 (CI 77891); witch hazel extract; ethanol; water; dimethicone; ammonium acrylate copolymer; glycerol; polyethylene glycol; D-glucopyranose, oligomer, decyl octyl glycoside; and D-glucopyranose, oligomer, C10-16-alkyl glycoside. White pigment dispersions may have a viscosity of approximately 500 cP to approximately 2000 cP, as measured using any standard viscometer, also known as a viscometer or rheometer, such as the Viscolite 700 portable viscometer.

[0043] A pigment dispersion or blue pigment dispersion may comprise: a pigment selected from Pigment Blue 15 (CI 74160), Pigment Blue 16 (CI 74100), Pigment Blue 60 (CI 69800) and combinations thereof; one or more solvents; and one or more additives. The solvent may be witch hazel extract, ethanol, water, or any combination thereof. The additive may be selected from: defoamers (e.g., dimethicone), dispersants (e.g., ammonium acrylate copolymers), binders, humectants (e.g., glycerin), wetting agents (e.g., alkyl polyglycosides), and any combination thereof. A blue pigment dispersion may comprise: a pigment selected from Pigment Blue 15 (CI 74160), Pigment Blue 16 (CI 74100), Pigment Blue 60 (CI 69800) and combinations thereof; one or more solvents; defoamers (e.g., dimethicone); dispersants (e.g., ammonium acrylate copolymers); binders; humectants (e.g., glycerin); and one or more additives. Blue pigment dispersions may contain Pigment Blue 15 (CI74160), witch hazel extract, ethanol, water, dimethicone, ammonium acrylate copolymer, glycerin, polyethylene glycol, alkyl polysaccharide glycoside, and one or more additional additives optionally present. The blue pigment dispersion may contain Pigment Blue 15 (CI74160), witch hazel extract; ethanol; water; dimethicone; ammonium acrylate copolymer; glycerin; polyethylene glycol; D-glucopyranose, oligomer, decyl octyl glycoside; and D-glucopyranose, oligomer, C10-16-alkyl glycoside. Pigment Blue 15 pigment dispersions may have a viscosity of about 20 cP to about 100 cP, as measured using any standard viscometer, also known as a viscometer or rheometer, such as the Viscolite 700 portable viscometer.

[0044] Blue pigment dispersions may comprise Pigment Blue 16 (CI 74100), witch hazel extract, ethanol, water, dimethicone, ammonium acrylate copolymer, glycerin, polyethylene glycol, alkyl polysaccharide glycoside, and optionally one or more additional additives. The blue pigment dispersion may comprise Pigment Blue 16 (CI 74100); witch hazel extract; ethanol; water; dimethicone; ammonium acrylate copolymer; glycerin; polyethylene glycol; D-glucopyranose, oligomer, decyl octyl glycoside; and D-glucopyranose, oligomer, C10-16-alkyl glycoside. Pigment Blue 16 (CI 74100) pigment dispersions may have a viscosity of about 20 cP to about 200 cP, as determined using any standard viscometer.

[0045] Blue pigment dispersions may comprise Pigment Blue 60 (CI 69800), witch hazel extract, ethanol, water, dimethicone, ammonium acrylate copolymer, glycerin, polyethylene glycol, alkyl polysaccharide glycoside, and optionally one or more additional additives. The blue pigment dispersion may comprise Pigment Blue 60 (CI 69800); witch hazel extract; ethanol; water; dimethicone; ammonium acrylate copolymer; glycerin; polyethylene glycol; D-glucopyranose, oligomer, decyl octyl glycoside; and D-glucopyranose, oligomer, C10-16-alkyl glycoside. Pigment Blue 60 (CI 69800) pigment dispersions may have a viscosity of about 20 cP to about 100 cP, as determined using any standard viscometer.

[0046] The pigment dispersion or green pigment dispersion may comprise: a pigment selected from Pigment Green 36 (CI 74265), Pigment Green 7 (CI 74260), Pigment Yellow 151 (CI 13980), Pigment Blue 16 (CI 74100), Pigment Blue 60 (CI 69800), and any combination thereof; one or more solvents; and one or more additives. The solvent may be witch hazel extract, ethanol, water, or any combination thereof. The additive may be selected from: defoamers (e.g., dimethicone), dispersants (e.g., ammonium acrylate copolymers), binders, humectants (e.g., glycerin), wetting agents (e.g., alkyl polysaccharides), and any combination thereof. Green pigment dispersions may comprise pigments selected from Pigment Green (CI 74265), Pigment Green 7 (CI 74260), Pigment Yellow 151 (CI 13980), Pigment Blue 16 (CI 74100), Pigment Blue 60 (CI 69800), and any combination thereof; one or more solvents; defoamers (e.g., dimethicone); dispersants (e.g., ammonium acrylate copolymers); binders; humectants (e.g., glycerin); and one or more additives. Green pigment dispersions may comprise Pigment Green 36 (CI 74265), witch hazel extract, ethanol, water, dimethicone, ammonium acrylate copolymer, glycerin, polyethylene glycol, alkyl polysaccharides, and optionally one or more additional additives. The green pigment dispersion may contain Pigment Green (CI 74265); Witch Hazel Extract; Ethanol; Water; Dimethicone; Ammonium Acrylate Copolymer; Glycerin; Polyethylene Glycol; D-glucopyranose, oligomer, decyl octyl glycoside; and D-glucopyranose, oligomer, C10-16-alkyl glycoside. Pigment Green 36 pigment dispersion may have a viscosity of approximately 20 cP to approximately 200 cP, as measured using any standard viscometer, also known as a viscometer or rheometer, such as the Viscolite 700 portable viscometer.

[0047] Green pigment dispersions may comprise Pigment Yellow 151 (CI 13980) and Pigment Blue 16 (CI 74100) and / or Pigment Blue 60 (CI 69800), witch hazel extract, ethanol, water, dimethicone, ammonium acrylate copolymer, glycerin, polyethylene glycol, alkyl polysaccharide, and one or more additional additives optionally present. Green pigment dispersions may comprise Pigment Yellow 151 (CI 13980) and Pigment Blue 16 (CI 74100) and / or Pigment Blue 60 (CI 69800); witch hazel extract; ethanol; water; dimethicone; ammonium acrylate copolymer; glycerin; polyethylene glycol; D-glucopyranose, oligomer, decyl octyl glycoside; and D-glucopyranose, oligomer, C10-16-alkyl glycoside.

[0048] The green pigment dispersion may contain pigment green (CI 74260), witch hazel extract, ethanol, water, dimethicone, ammonium acrylate copolymer, glycerin, polyethylene glycol, alkyl polysaccharide glycoside, and one or more additional additives optionally present. The blue pigment dispersion may contain pigment green (CI 74260); witch hazel extract; ethanol; water; dimethicone; ammonium acrylate copolymer; glycerin; polyethylene glycol; D-glucopyranose, oligomer, decyl octyl glycoside; and D-glucopyranose, oligomer, C10-16-alkyl glycoside. The pigment green 7 pigment dispersion may have a viscosity of about 20 cP to about 200 cP, as measured using any standard viscometer, also known as a viscometer or rheometer, such as the Viscolite 700 portable viscometer.

[0049] Pigment dispersions or black pigment dispersions may contain carbon black (CI 77266), one or more solvents, and one or more additives. Solvents may be witch hazel extract, ethanol, water, or any combination thereof. Additives may be selected from: defoamers (e.g., dimethicone), dispersants (e.g., ammonium acrylate copolymers), binders, humectants (e.g., glycerin), wetting agents (e.g., alkyl polysaccharides), and any combination thereof. Black pigment dispersions may contain carbon black (CI 77266), one or more solvents, defoamers (e.g., dimethicone), dispersants (e.g., ammonium acrylate copolymers), binders, humectants (e.g., glycerin), and one or more additives. Black pigment dispersions may contain carbon black (CI 77266), witch hazel extract, ethanol, water, dimethicone, ammonium acrylate copolymers, glycerin, polyethylene glycol, alkyl polysaccharides, and optionally one or more additional additives. Black pigment dispersions may contain carbon black (CI 77266); witch hazel extract; ethanol; water; dimethicone; ammonium acrylate copolymer; glycerol; polyethylene glycol; D-glucopyranose, oligomer, decyl octyl glycoside; and D-glucopyranose, oligomer, C10-16-alkyl glycoside. Black pigment dispersions may have a viscosity of approximately 5 cP to approximately 50 cP, as determined using any standard viscometer, also known as a viscometer or rheometer, such as the Viscolite 700 portable viscometer.

[0050] The pigment dispersion or orange pigment dispersion may comprise Pigment Orange 64 (CI 12760), one or more solvents, and one or more additives. The solvent may be witch hazel extract, ethanol, water, or any combination thereof. The solvent may be witch hazel extract, ethanol, and water. The additive may be selected from: defoamers (e.g., dimethicone), dispersants (e.g., ammonium acrylate copolymers), binders, humectants (e.g., glycerin), wetting agents (e.g., alkyl polysaccharides), and any combination thereof. The orange pigment dispersion may comprise Pigment Orange 64 (CI 12760), one or more solvents, defoamers (e.g., dimethicone), dispersants (e.g., ammonium acrylate copolymers), binders, humectants (e.g., glycerin), and one or more additives. The orange pigment dispersion may comprise Pigment Orange 64 (CI 12760), witch hazel extract, ethanol, water, dimethicone, ammonium acrylate copolymer, glycerin, polyethylene glycol, alkyl polysaccharides, and optionally one or more additives. Orange pigment dispersions may contain Pigment Orange 64 (CI 12760); witch hazel extract; ethanol; water; dimethicone; ammonium acrylate copolymer; glycerol; polyethylene glycol; D-glucopyranose, oligomer, decyl octyl glycoside; and D-glucopyranose, oligomer, C10-16-alkyl glycoside. Orange pigment dispersions may have a viscosity of approximately 50 cP to approximately 200 cP, as measured using any standard viscometer, also known as a viscometer or rheometer, such as the Viscolite 700 portable viscometer.

[0051] A pigment dispersion or magenta pigment dispersion may comprise Pigment Red 202 (CI 73907), one or more solvents, and one or more additives. The solvent may be witch hazel extract, ethanol, water, or any combination thereof. The additive may be selected from: defoamers (e.g., dimethicone), dispersants (e.g., ammonium acrylate copolymers), binders, humectants (e.g., glycerin), wetting agents (e.g., alkyl polysaccharides), and any combination thereof. A magenta pigment dispersion may comprise Pigment Red 202 (CI 73907), one or more solvents, defoamers (e.g., dimethicone), dispersants (e.g., ammonium acrylate copolymers), humectants (e.g., glycerin), and one or more additives. A magenta pigment dispersion may comprise Pigment Red 202 (CI 73907), witch hazel extract, ethanol, water, dimethicone, ammonium acrylate copolymers, glycerin, polyethylene glycol, alkyl polysaccharides, and optionally one or more additives. Magenta pigment dispersions may contain Pigment Red 202 (CI 73907); witch hazel extract; ethanol; water; dimethicone; ammonium acrylate copolymer; glycerol; polyethylene glycol; D-glucopyranose, oligomer, decyl octyl glycoside; and D-glucopyranose, oligomer, C10-16-alkyl glycoside. Magenta pigment dispersions may have a viscosity of approximately 50 cP to approximately 200 cP, as measured using any standard viscometer, also known as a viscometer or rheometer, such as the Viscolite 700 portable viscometer.

[0052] A pigment dispersion or a red pigment dispersion may comprise Pigment Red 254 (CI 56110), one or more solvents, and one or more additives. The solvent may be witch hazel extract, ethanol, water, or any combination thereof. The additive may be selected from: defoamers (e.g., dimethicone), dispersants (e.g., ammonium acrylate copolymers), binders, humectants (e.g., glycerin), wetting agents (e.g., alkyl polysaccharides), and any combination thereof. A red pigment dispersion may comprise Pigment Red 254 (CI 56110), one or more solvents, defoamers (e.g., dimethicone), dispersants (e.g., ammonium acrylate copolymers), humectants (e.g., glycerin), and one or more additives. A red pigment dispersion may comprise Pigment Red 254 (CI 56110), witch hazel extract, ethanol, water, dimethicone, ammonium acrylate copolymers, glycerin, polyethylene glycol, alkyl polysaccharides, and optionally one or more additional additives. Red pigment dispersions may contain Pigment Red 254 (CI 56110); witch hazel extract; ethanol; water; dimethicone; ammonium acrylate copolymer; glycerol; polyethylene glycol; D-glucopyranose, oligomer, decyl octyl glycoside; and D-glucopyranose, oligomer, C10-16-alkyl glycoside. Red pigment dispersions may have a viscosity of approximately 5 cP to approximately 50 cP, as determined using any standard viscometer, also known as a viscometer or rheometer, such as the Viscolite 700 portable viscometer.

[0053] A pigment dispersion or a yellow pigment dispersion may comprise Pigment Yellow 151 (CI 13980), one or more solvents, and one or more additives. The solvent may be witch hazel extract, ethanol, water, or any combination thereof. The additive may be selected from: defoamers (e.g., dimethicone), dispersants (e.g., ammonium acrylate copolymers), binders, humectants (e.g., glycerin), wetting agents (e.g., alkyl polysaccharides), and any combination thereof. A yellow pigment dispersion may comprise Pigment Yellow 151 (CI 13980), one or more solvents, defoamers (e.g., dimethicone), dispersants (e.g., ammonium acrylate copolymers), humectants (e.g., glycerin), and one or more additives. A yellow pigment dispersion may comprise Pigment Yellow 151 (CI 13980), witch hazel extract, ethanol, water, dimethicone, ammonium acrylate copolymers, glycerin, polyethylene glycol, alkyl polysaccharides, and optionally one or more additives. Yellow pigment dispersions may contain Yellow 151 (CI 13980); witch hazel extract; ethanol; water; dimethicone; ammonium acrylate copolymer; glycerol; polyethylene glycol; D-glucopyranose, oligomer, decyl octyl glycoside; and D-glucopyranose, oligomer, C10-16-alkyl glycoside. Pigment Yellow 151 pigment dispersions may have a viscosity of approximately 10 cP to approximately 100 cP, as measured using any standard viscometer, also known as a viscometer or rheometer, such as the Viscolite 700 portable viscometer.

[0054] A pigment dispersion or a yellow pigment dispersion may comprise Pigment Yellow 180 (CI 21290), one or more solvents, and one or more additives. The solvent may be witch hazel extract, ethanol, water, or any combination thereof. The additive may be selected from: defoamers (e.g., dimethicone), dispersants (e.g., ammonium acrylate copolymers), binders, humectants (e.g., glycerin), wetting agents (e.g., alkyl polysaccharides), and any combination thereof. A yellow pigment dispersion may comprise Pigment Yellow 180 (CI 21290), one or more solvents, defoamers (e.g., dimethicone), dispersants (e.g., ammonium acrylate copolymers), binders, humectants (e.g., glycerin), and one or more additives. A yellow pigment dispersion may comprise Pigment Yellow 180 (CI 21290), witch hazel extract, ethanol, water, dimethicone, ammonium acrylate copolymers, glycerin, polyethylene glycol, alkyl polysaccharides, and optionally one or more additives. Yellow pigment dispersions may contain Pigment Yellow 180 (CI 21290); witch hazel extract; ethanol; water; dimethicone; ammonium acrylate copolymer; glycerol; polyethylene glycol; D-glucopyranose, oligomer, decyl octyl glycoside; and D-glucopyranose, oligomer, C10-16-alkyl glycoside. Pigment Yellow 180 pigment dispersions may have a viscosity of about 50 cP to about 200 cP, as measured using any standard viscometer, also known as a viscometer or rheometer, such as the Viscolite 700 portable viscometer.

[0055] The pigment dispersion may contain about 20% to about 60% by weight, about 20% to about 50% by weight, about 20% to about 40% by weight, about 20% to about 30% by weight, about 30% to about 40% by weight, about 30% to about 60% by weight, about 20% to about 25% by weight, or about 25% to about 30% by weight of the total pigment dispersion. The pigment dispersion may contain about 20% to about 50% by weight, about 20% to about 40% by weight, about 30% to about 40% by weight, about 20% to about 30% by weight, or about 25% to about 30% by weight of water. The pigment dispersion may contain about 10% to about 25% by weight, about 10% to about 15% by weight, about 15% to about 20% by weight, about 10% to about 20% by weight, or about 20% to about 25% by weight of witch hazel extract. The pigment dispersion may comprise about 1% to about 20% by weight, about 1% to about 10% by weight, about 1% to about 5% by weight, about 1% to about 3% by weight, or about 2% to about 4% by weight of ammonium acrylate copolymers in the total pigment dispersion. The pigment dispersion may comprise about 1% to about 5% by weight, about 3% to about 5% by weight, about 1% to about 3% by weight, or about 2% to about 4% by weight of glycerol in the total pigment dispersion. The pigment dispersion may comprise about 1% to about 5% by weight, about 3% to about 5% by weight, about 1% to about 3% by weight, or about 2% to about 4% by weight of propylene glycol in the total pigment dispersion. The pigment dispersion may comprise about 1% to about 5% by weight, about 3% to about 5% by weight, about 1% to about 3% by weight, or about 2% to about 4% by weight of ethanol in the total pigment dispersion. The pigment dispersion may comprise about 1% to about 15% by weight, about 3% to about 10% by weight, or about 5% to about 10% by weight of alkyl polysaccharide glycosides in the total pigment dispersion. The pigment dispersion may contain about 1% to about 5% by weight, about 3% to about 5% by weight, about 1% to about 3% by weight, or about 2% to about 4% by weight of D-glucopyranose, oligomer, decyl octyl glycoside, of the total pigment dispersion. The pigment dispersion may contain about 1% to about 5% by weight, about 3% to about 5% by weight, about 1% to about 3% by weight, or about 2% to about 4% by weight of D-glucopyranose, oligomer, C10-16-alkyl glycoside, of the total pigment dispersion. The pigment dispersion may contain about 0.05% to about 1% by weight, about 0.1% to about 0.9% by weight, about 0.5% to about 0.8% by weight, or about 0.3% to about 0.9% by weight of dimethicone oil, of the total pigment dispersion.

[0056] The particle size range in the pigment dispersion can be from about 150 nm to about 15 µm, from about 150 nm to about 10 µm, from about 150 nm to about 3 µm, from about 85 nm to about 15 µm, from about 85 nm to about 3 µm, from about 70 nm to about 15 µm, from about 70 nm to about 10 µm, from about 70 nm to about 3 µm, from about 60 nm to about 2 µm, from about 50 nm to about 10 µm, or from about 50 nm to about 3 µm. The particle size distribution can be determined using any apparatus and method known in the art for this purpose. For example, particle size can be determined using Microtrac, SYNC 3RL, FLOWSYNC (wet analysis) by laser diffraction, and optionally specifically by laser diffraction ISO 13320:2020.

[0057] The particle size distribution D90 (90% volume) of a pigment dispersion can be less than about 6 μm, less than about 3 μm, less than about 700 nm, less than about 650 nm, less than about 600 nm, less than about 500 nm, less than about 450 nm, less than about 400 nm, less than about 300 nm, or less than about 200 nm. The particle size distribution D90 (90% volume) of a pigment dispersion can be from about 100 nm to about 6 μm, from about 200 nm to about 3 μm, from about 200 nm to about 1 μm, from about 400 nm to about 900 nm, from about 200 nm to about 700 nm, from about 200 nm to about 500 nm, from about 200 nm to about 400 nm, or from about 250 nm to about 300 nm. Particle size affects toxicity, whole-body exposure, and ink performance. The particle size distribution of any pigment will consist of clusters of particles of multiple sizes. More than about 50% of the particles may be in the micrometer range, and may be about 0.5 µm to about 1 µm, about 1 µm to about 2 µm, about 2 µm to about 3 µm, or about 3 µm to about 4 µm, or about 4 µm to about 5 µm. The pigment dispersion may contain one or more particle groups in the nanoparticle range. The pigment dispersion may contain less than about 1% to about 5% by volume, about 1% to about 3% by volume, or about 2% to about 3% by volume nanoparticles in the 1 nm to 100 nm range. The pigment dispersion may contain less than about 1% by volume, about 1% by volume, about 2% by volume, about 3% by volume, about 4% by volume, or about 5% by volume nanoparticles in the 1 nm to 100 nm range.

[0058] Table 1 shows some parameters of the particle size of pigment dispersions containing different pigments.

[0059] Table 1

[0060] The impurity content of the pigment dispersions disclosed herein has been reduced through the use of a carefully developed processing procedure. Raw material suppliers should adhere to consistent quality management systems and practices to ensure product stability (e.g., ISO 9001 guidelines). ISO is the International Organization for Standardization, which provides specific requirements covering all aspects of quality and safety for both raw materials and finished products. Pigment dispersions may meet the purity requirements stipulated in European Commission Regulation (EU) 2020 / 2081 (“EU Regulation”). According to the EU Regulation, pigment dispersions must not contain the following impurities in excess of specified limits: 1. According to Annex XVII (Reach) of EU Regulation 1907 / 2006, the limit for free primary aromatic amines (PAA) is 5 ppm for each PAA; 2. According to Annex XVII, Annex 13 of EU Regulation 1907 / 2006, the limits for heavy metals in each class of heavy metals are specified in the referenced regulation.

[0061] 3. The limit for polycyclic aromatic hydrocarbons (PAHs) is 0.5 ppm for each PAH compound, and the limit for benzo[a]pyrene is 5 ppb; 4. The limit for methanol is 11% by weight; 5. The limits for dyes, pigments and colorants listed in Annex XVII, Annex 13 of EU Regulation 1907 / 2006 are 0.1%; 6. Preservatives, phthalates and other substances having the following hazard classifications, according to Annex VI, Part 3 of EU Regulation 1272 / 2008: a. Class 1A, 1B or 2 carcinogens, or Class 1A, 1B or 2 germ cell mutagens; limit of 0.00005% by weight. b. Reproductive toxicants of category 1A, 1B or 2; limit of 0.001% by weight. c. 1. Class 1A or 1B skin sensitizers; limit is 0.001% by weight. d. 1. Class 1A, 1B or 1C skin corrosive substances, or Class 2 skin irritants, or Class 1 serious eye irritants or Class 2 eye irritants; if used only as a pH adjuster, the limit is 0.1% by weight, and in all other cases the limit is 0.01% by weight.

[0062] 7. Substances listed in Annex IV to Regulation 1223 / 2009 of the European Parliament and of the Council: a. Limited to 0.0005% by weight; 8. Substances listed in Annex IV to EU Regulation 1223 / 2009, wherein at least one of the following conditions is specified in columns g, h and I of the tables in that annex: a. “Rinse products”; limited to 0.00005% by weight%. b. "Not for use in adhesive films"; the limit is 0.00005% by weight. c. "Not for use in eye products"; limit is 0.00005g by weight.

[0063] The pigment dispersion may contain the following specified impurities: less than or equal to about 0.5 ppm of total polycyclic aromatic hydrocarbons; less than about 5 ppb of benzo[a]pyrene (BaP); less than 5 ppm of primary aromatic amines; and / or less than 11% by weight of methanol.

[0064] Table 2 shows examples of acceptable limits for certain metals present in the pigment dispersions disclosed herein. Pigment dispersions may have limits less than those listed in Table 2 for each metal. Pigment dispersions may contain less than about 0.5 ppm of impurities selected from: mercury, organometallic tin, antimony, arsenic, cadmium, chromium (Cr(VI)), or any combination thereof. Pigment dispersions may contain less than about 0.7 ppm of lead. Pigment dispersions may contain less than about 5 ppm of nickel. Pigment dispersions may contain less than about 500 ppm of barium. Pigment dispersions may contain less than about 250 ppm of copper. Pigment dispersions may contain less than about 2 ppm of selenium. Pigment dispersions may contain less than about 2000 ppm of zinc.

[0065] Table 2

[0066] The pigment dispersions disclosed herein may contain less than 0.5 ppm of one or more polyaromatic hydrocarbons listed in Table 3. The pigment dispersions disclosed herein may contain less than 0.005 ppm (5 ppb) of benzo[a]pyrene. The pigment dispersions disclosed herein may contain less than 0.005 ppm (5 ppb) of benzo[a]pyrene and less than 0.5 ppm of one or more polyaromatic hydrocarbons listed in Table 3.

[0067] Table 3: Polyaromatic Hydrocarbons

[0068] The pigment dispersions disclosed herein may contain less than about 5 ppm of the free aromatic amines listed in Table 4, which is set out in accordance with Annex XVII (Reach) of European Parliament and the Council Method Regulation 1907 / 2006. The compounds in Table 4 were extracted with MeOH and analyzed by GC / MS.

[0069] Table 4: Free Aromatic Amines

[0070] **Soluble This invention discloses a tattoo ink formulation comprising any of the pigment dispersions disclosed herein. The tattoo ink formulation may comprise: a pigment dispersion comprising: TiO2 (CI 77891), Pigment Blue 15 (CI 74160), Carbon Black (CI 77266), Pigment Orange 64 (CI 12760), Pigment Red 202 (CI 73907), Pigment Red 254 (CI 56110), Pigment Yellow 151 (CI 13980), Pigment Yellow 180 (CI 21290), Pigment Blue 16 (CI 74100), Pigment Blue 60 (CI 69800), Pigment Green 36 (CI 74265), Pigment Green 7 (CI 74260), or any combination thereof; a solvent; and at least one additive. The tattoo ink formulation may comprise less than about 95% by weight, about 1% by weight, to about 95% by weight, or about 10% by weight, to about 95% by weight of the pigment dispersion.

[0071] Tattoo ink formulations may comprise pigment dispersions comprising: TiO2 (CI 77891), Pigment Blue 15 (CI 74160), Carbon Black (CI 77266), Pigment Orange 64 (CI 12760), Pigment Red 202 (CI 73907), Pigment Red 254 (CI 56110), Pigment Yellow 151 (CI 13980), Pigment Yellow 180 (CI 21290), Pigment Blue 16 (CI 74100), Pigment Blue 60 (CI 69800), Pigment Green 36 (CI 74265), Pigment Green 7 (CI 74260), or any combination thereof; a solvent selected from water, ethanol, witch hazel extract, and combinations thereof; and glycerin. Tattoo ink formulations may comprise any pigment dispersion disclosed herein. The tattoo ink formulation may contain about 1% to about 50% by weight, about 10% to about 40% by weight, about 1% to about 30% by weight, or about 20% to about 40% by weight of the total tattoo ink formulation, of witch hazel extract. The tattoo ink formulation may contain about 1% to about 50% by weight, about 10% to about 40% by weight, about 1% to about 30% by weight, or about 20% to about 40% by weight of water. The tattoo ink formulation may contain about 1% to about 40% by weight, about 10% to about 40% by weight, about 1% to about 30% by weight, about 10% to about 20% by weight, or about 20% to about 40% by weight of glycerin. The tattoo ink formulation may contain about 0.1% to about 5% by weight, about 1% to about 5% by weight, about 0.5% to about 3% by weight, or about 0.1% to about 2% by weight of ethanol. Tattoo ink formulations can have viscosities of less than about 500 cP, about 50 cP to about 500 cP, or about 2000 cP to about 500 cP, as measured using any standard viscometer, which may also be called a viscometer or rheometer, such as the Viscolite 700 portable viscometer.

[0072] The tattoo ink formulations disclosed herein may contain less than about 5% by weight, less than about 4% by weight, less than about 3% by weight, less than about 2% by weight, and less than about 1% by weight of impurities. The tattoo ink formulations disclosed herein may contain less than about 5 ppm of the free aromatic amines listed in Table 4.

[0073] Tattoo ink formulations may contain less than or equal to about 0.5 ppm of total polycyclic aromatic hydrocarbons (PAHs). Tattoo ink formulations may contain: less than or equal to about 5 ppm of free aromatic amines listed in Table 4; less than or equal to about 11% by weight of methanol; less than or equal to about 0.1% by weight of dyes, pigments, and colorants listed in Table 5 and European Commission Regulation (EU) 2020 / 208; less than or equal to about 0.5 ppm of Group 1A, 1B, or 2 carcinogens or Group 1A, 1B, or 2 germ cell mutagens under Annex VI Part 3 of EU Regulation (EC) 1272 / 2008 (http: / / data.europa.eu / eli / reg / 2008 / 1272 / 2022-03-01); less than or equal to about 10% by weight of total PAHs. ppm of substances classified as reproductive toxicants or skin sensitizers of categories 1A, 1B or 2 according to Annex VI Part 3 of EU Regulation (EC) 1272 / 2008 (http: / / data.europa.eu / eli / reg / 2008 / 1272 / 2022-03-01); less than or equal to about 100 ppm of substances classified as skin corrosives, or skin irritants of category 2, or serious eye irritants of category 1, 1A, 1B or 1C according to Annex VI Part 3 of EU Regulation (EC) 1272 / 2008 (http: / / data.europa.eu / eli / reg / 2008 / 1272 / 2022-03-01); less than or equal to about 5 ppm of substances classified as skin corrosives, or skin irritants of category 2, or serious eye irritants of category 1 or 2 ...). Substances listed in Annex II of EU Regulation (EC) 1223 / 2009 at concentrations of ppm (http: / / data.europa.eu / eli / reg / 2009 / 1223 / 2022-10-06); and substances listed in Annex IV of EU Regulation (EC) 1223 / 2009 at concentrations of 0.5 ppm or less (http: / / data.europa.eu / eli / reg / 2009 / 1223 / 2022-10-06), which are applicable to the following categories: “rinsing products”, “not for use in mucous membrane products”, and “not for use in eye products”.

[0074] Table 5

[0075] The weight loss of tattoo ink formulations is approximately 0% to approximately 4% when heated at approximately 950°C for approximately 7 minutes.

[0076] The tattoo ink formulations disclosed herein can be formulated without the addition of tea, mineral oil, petroleum, or any of the aforementioned ingredients. The pigment dispersions disclosed herein can be formulated without the addition of tea, mineral oil, petroleum, or any of the aforementioned ingredients.

[0077] A method for preparing the pigment dispersions disclosed herein is also disclosed. The pigment dispersions (also known as base colorants) are preferably manufactured in a controlled environment. The manufacturing facility may be certified according to ISO 22716:2007 and ISO 9001:2015 for cosmetics, ISO 13485:2016 for medical devices, or any similar or later versions of these standards. The consistency of the pigment dispersions can be monitored intermittently by recording viscosity (Viscolite VL700 d21 or similar instruments) and spectral properties (using a spectrophotometer).

[0078] Methods for preparing pigment dispersions may include mixing pigments with other components using a high-shear mixer, also known as a high-shear reactor, rotor-stator mixer, or high-shear homogenizer. The functional component of the high-shear mixer, called the mixer head or generator, generates shear forces to disperse the pigments. The mixer head may include a rotatable rotor or impeller and a stationary stator. The magnitude of the shear force applied to the mixture can be adjusted by changing the speed of the rotor. Rotary rotor speeds can range from about 1,000 feet per minute (FPM) to about 20,000 FPM, about 2,000 FPM to about 10,000 FPM, about 2,000 FPM to about 5,000 FPM, about 5,000 FPM to about 10,000 FPM, or about 10,000 FPM to about 20,000 FPM. The short distance between the rotatable rotor and the stationary stator creates a shear rate range of about 20,000 s⁻¹ at any point. -1 From approximately 100,000 s -1 The ultra-high shear zone. The stationary stator may have a stator head including openings. The openings on the stator head may be adjustable. The stator head openings may be circular, square, slotted, or fine-sieve-like. The mixer head may include multiple layers of rotating and stationary components, forming a rotor / stator array. When undispersed liquid / solid is axially drawn into the rotor / stator and radially discharged through the openings on the stator head, the pigment becomes dispersed.

[0079] According to this disclosure, various high-shear mixer configurations can be used to disperse pigments. These configurations include intermittent high-shear mixers, in-line high-shear mixers, and powder-induced high-shear mixers. The total mixing time can be from about 1 hour to about 5 hours, from about 1 hour to about 4 hours, or from about 2 hours to about 4 hours.

[0080] When using an intermittent high-shear mixer, all components are added from the top of a single tank or container. The mixer head can be located on a rotating shaft at the bottom of the tank, or it can be suspended inside the tank for adjustable height. The order of addition can be liquid first, followed by pigment powder, powder first, followed by liquid, or both liquid and pigment powder can be added simultaneously. The shear force applied to the mixture can be set by adjusting the rotor speed (RPM). Rotor speeds can be approximately 1,000 RPM to approximately 2,000 RPM, approximately 2,000 RPM to approximately 4,000 RPM, or approximately 4,000 RPM to approximately 10,000 RPM. The rotor speed can remain constant or gradually increase throughout the dispersion process. The mixture temperature can be maintained at ambient room temperature, such as about 68°F to about 77°F (about 20°C to about 25°C), or the mixture can be heated to about 110°F (about 43°C), resulting in a temperature range of about 68°F to about 110°F (about 20°C to about 43°C). Mixing can continue until the solution becomes homogeneous. Homogeneity can be checked qualitatively by spreading the ink onto a flat surface and observing any aggregates.

[0081] For inline high-shear mixers, the shear mixer is housed in an external chamber with inlet and outlet pipes that return the material to the main reservoir. The shear force applied to the mixture can be set by adjusting the rotor speed (RPM). Rotor speeds can be from about 1,000 RPM to about 2,000 RPM, from about 2,000 RPM to about 4,000 RPM, or from about 4,000 RPM to about 10,000 RPM. The rotor speed can be kept constant or gradually increased throughout the dispersion process. The mixture flow rate can also be adjusted, and the flow rate is typically from about 5 to about 50,000 gallons per hour. The mixture temperature can be maintained at ambient room temperature, for example, from about 68°F to about 77°F (about 20°C to about 25°C), or it can be heated to about 110°F (about 43°C), resulting in a temperature range of about 68°F to about 110°F (about 20°C to about 43°C). Mixing can continue until the solution becomes homogeneous. Uniformity can be checked qualitatively by spreading the ink onto a flat surface and observing any aggregates. In-line high-shear mixers can shorten dispersion time and provide more controlled particle size reduction. In-line mixing proceeds in a continuous flow, which more effectively wets and stabilizes pigment particles. This also prevents clumping, which hinders the dispersion efficiency of intermittent high-shear mixing.

[0082] For powder-induced high-shear mixers, a vacuum system is used to draw the powder components directly into the mixing head. Simultaneously, liquid circulates through the mixing head via an accompanying pipe / line. This allows for more controlled addition of the powder components to the dispersion process. The liquid recirculation line speed can also be adjusted, typically from approximately 5 to approximately 50,000 gallons per hour. The shear force applied to the mixture can be set by adjusting the rotor speed (RPM). Rotor speeds can be from approximately 1,000 RPM to approximately 2,000 RPM, from approximately 2,000 RPM to approximately 4,000 RPM, or from approximately 4,000 RPM to approximately 10,000 RPM. The rotor speed can be kept constant or gradually increased throughout the dispersion process. The mixture temperature can be maintained at ambient room temperature, for example, from approximately 68°F to approximately 77°F (approximately 20°C to approximately 25°C), or heated to approximately 110°F (approximately 43°C), resulting in a temperature range of approximately 68°F to approximately 110°F (approximately 20°C to approximately 43°C). Mixing can continue until the solution becomes homogeneous. Uniformity can be checked qualitatively by spreading the ink onto a flat surface and observing any aggregates.

[0083] By using an online high-shear mixer instead of an intermittent high-shear mixer, pigment dispersions containing Pigment Blue 60 pigment can achieve better results in reducing particle size. Alternatively, the liquid mixture can first be passed through a media mill (or other similarly functional device known in the art) and then mixed in an intermittent high-shear mixer.

[0084] This invention discloses a method for preparing a pigment dispersion, comprising combining the following components to prepare a solution: at least one solvent selected from witch hazel extract, ethanol, water, or any combination thereof; dimethicone; glycerin; a dispersant; and one or more additives, and then mixing the solution to prepare a homogeneous mixture. The homogeneous mixture is placed in a high-shear mixer at about 2000 RPM to about 4000 RPM and the pigment is added. Mixing is continued at a temperature of about 68°F to about 110°F for about 1 hour to about 4 hours, about 2 hours to about 4 hours, or about 2 hours to about 3 hours to prepare a homogeneous pigment dispersion.

[0085] This invention discloses a method for preparing a powder-induced pigment dispersion, comprising combining the following components to prepare a solution: at least one solvent selected from witch hazel extract, ethanol, water, or any combination thereof; dimethicone; glycerin; a dispersant; and one or more additives, and then mixing the solution to prepare a homogeneous mixture. The homogeneous mixture is placed in an online high-shear mixer at approximately 3000 RPM to approximately 4000 RPM, approximately 3500 RPM to approximately 4000 RPM, or approximately 3600 RPM, while pigment is added to the homogeneous mixture via a powder-inducing system. The powder-inducing system, such as the ADMIX® Fastfeed® powder-inducing and dispersing system, includes a vacuum pump capable of operating at approximately 14 inches of mercury. The vacuum pump draws powder into the online high-shear mixer and circulates the mixture within the online high-shear mixer. The powder-inducing system can be coupled to the online high-shear mixer in any manner known in the art. Mixing continues at a temperature of approximately 68°F to approximately 110°F for approximately 1 hour to approximately 4 hours, approximately 2 hours to approximately 4 hours, or approximately 2 hours to approximately 3 hours to form a homogeneous pigment dispersion. Uniformity can be checked qualitatively by spreading the ink onto a flat surface and observing any aggregates.

[0086] The method may also include cooling the online high-shear mixer with water (optionally using an external cooling bath) while mixing.

[0087] The base pigment dispersion is used to produce the final ready-to-use product. The preparation of the final ready-to-use product must be carried out in an ISO-certified Class 6 cleanroom. Quality control checks established according to ISO 22716:2007, ISO 9001:2015, and ISO 13485:2016 are used to ensure batch-to-batch consistency. These checks include, but are not limited to, tattoo ink density, viscosity, UV-Vis spectral properties, color intensity, pH value, formulation, and sterility.

[0088] The final tattoo ink product should be free from any microbial contamination, including the following microbial categories. The detection limit should be less than 10 colony-forming units / gram (CFU / g).

[0089] The types of microorganisms to be tested are: 1. Spores formed by aerobic bacterial spores 2. Spores formed by anaerobic bacteria 3. Suspected Bacillus cereus 4. Sulfite-reducing Clostridium 5. Total viable count, aerobic mesophilic bacteria at 30℃ 6. Total viable count, anaerobic mesophilic bacteria at 30℃ 7. Pseudomonas ( ) Pseudomonas sp. ).

[0090] All final tattoo ink products must be sterilized before retail. Sterilization can be accomplished using X-ray or gamma ray irradiation. The sterilization process can be verified via USP. <71> Verification can be performed using methods similar to these methods. Outsourced aseptic facilities may have the following certifications: ISO 9001:2015, ISO 13485:2016, or both.

[0091] Example Example 1: Carbon black pigment dispersion process Dispensing liquid Weigh each dispersion component (liquid) according to the masterbatch formulation and then transfer it to the recirculation tank. Turn on the pump and the online shear mixer to circulate the liquid through the system. Allow the system to fill with liquid for at least 5 minutes.

[0092] Add pigment powder Before adding pigment powder, the operator must wear full-body cleanroom clothing and a face mask, including a safety mask. After checking that the liquid is circulating through the system, add the weighed powder to the hopper. Open the cooling water valve and the powder valve to allow the powder to enter the circulation line. Start the external tank agitator. The flow rate and pressure should be calibrated to achieve the recommended minimum pressure of 0.3 to 0.5 gallons per minute and 30 PSI.

[0093] Mixing and dispersing processes Once all powder has been added, close the powder valve and restrict the shear valve. Allow the liquid to shear mix for 2 hours.

[0094] Quality control Production managers must keep records during the powder dispersion process. After 2 hours, a sample is taken from the uniformly dispersed powder and allowed to cool to room temperature. Quality control personnel use a Hydromotion Viscolite 700 portable viscometer to measure the real-time viscosity reading. Acceptable viscosity readings are 10-200 cP. Quality control personnel obtain a drawdown of the dispersion and compare the CIE LAB value with established standards.

[0095] Stability data High-purity furnace black (carbon black) is known to be stable and inert. Chemical degradation is not expected. Although chemical degradation is not anticipated, recent concerns regarding tattoo safety have focused on the distribution of carbon black nanoparticles and its ability to induce reactive oxygen species. Three batches of black base pigment compositions, RMP004, RMP005, and RMP006, were manufactured. Stability studies were conducted on these three batches.

[0096] Stability study condition 1: The sample was stored in a controlled room at 25°C and 60% relative humidity.

[0097] Table 6. Summary of nanoparticle size distribution for batch RBP004 under condition 1

[0098] Table 7. Summary of nanoparticle size distribution for batch RBP005 under condition 1

[0099] Table 8. Summary of nanoparticle size distribution for batch RBP006 under condition 1

[0100] Stability study condition 2: The sample was stored in a controlled room at 40°C and 75% relative humidity.

[0101] Table 9. Summary of nanoparticle size distribution for batch RBP004 under condition 2

[0102] Table 10. Summary of nanoparticle size distribution for batch RBP005 under condition 2

[0103] Table 11. Summary of nanoparticle size distribution for batch RBP006 under condition 2

[0104] Example 2: Formulation of pigment dispersion Pigment dispersions of the formulations in Tables 12, 14, 16, 18, 20, 22 and 24 were prepared according to the following processing steps.

[0105] First, at room temperature, add the following ingredients (excluding pigments) to a mixing container: distilled water, solvent (e.g., witch hazel extract, ethanol), dispersant (e.g., ammonium acrylate copolymer), wetting agent (e.g., alkyl polysaccharide glycoside), humectant (e.g., glycerin, propylene glycol), and defoamer (e.g., dimethicone) and stir until homogeneous.

[0106] The colored pigment in powder form is then added in batches to the homogeneous dispersion solution. The resulting mixture is dispersed using an external high-shear mixer at a speed of 2000-4000 RPM. The speed of the high-shear mixer head is adjusted by the operator. The temperature of the mixture solution is maintained between 68℉ and 110℉ and mixed for 2-3 hours until the solution becomes homogeneous. Homogeneity is checked qualitatively by spreading the ink on a flat surface and observing any agglomerates. The resulting homogeneous mixture is a pigment dispersion that can be used to prepare tattoo ink formulations.

[0107] Pigment Black 7 Pigment Identity: Carbon Black; Pigment Black 7; High Purity Furnace Black; CI 77266 Basic color tone (shade): Black Table 12

[0108] The reflectance curve of the pigment black 7 dispersion processed by the above method is as follows: Figure 2 As shown in Table 13, the CIE LAB values ​​are presented. The term "basic pigment" used in the figure refers to the pigment dispersion.

[0109] Table 13

[0110] ¥ Dilute with a dilute solution containing distilled water / witch hazel extract / glycerin in a weight ratio of 1:1:1.

[0111] Pigment Blue 15 Pigment identification: Pigment Blue 15; Pigment Blue 15:3; CI 74160; Phthalocyanine Blue Basic colorant tone: blue Table 14

[0112] The reflectance curve of the Pigment Blue 15 pigment dispersion processed by the above method is as follows: Figure 3 As shown in Table 15, the CIE LAB values ​​are as follows.

[0113] Table 15

[0114] ¥ Dilute with a dilute solution containing distilled water / witch hazel extract / glycerin in a weight ratio of 1:1:1.

[0115] Pigment Orange 64 Pigment designation: Pigment Orange 6415; CI 12760 Basic colorant tone: orange Table 16

[0116] The reflectance curve of the Pigment Orange 64 pigment dispersion processed by the above method is shown in the figure. Figure 4 As shown, the CIE LAB values ​​are listed in Table 17. When preparing Pigment Orange 64 pigment dispersions, careful consideration is needed to ensure that the temperature of the mixing vessel does not exceed 110℉ during the initial mixing step (i.e., before adding the pigment), as the dissolution of Pigment Orange 64 is exothermic.

[0117] Table 17

[0118] ¥ Dilute with a dilute solution containing distilled water / witch hazel extract / glycerin in a weight ratio of 1:1:1.

[0119] Pigment Red 202 Pigment designation: Pigment Red 202; CI 73907 Basic color tone: magenta Table 18

[0120] The reflectance curve of the pigment red 202 dispersion processed by the above method is as follows: Figure 5 As shown in Table 19, the CIE LAB values ​​are as follows.

[0121] Table 19

[0122] ¥ Dilute with a dilute solution containing distilled water / witch hazel extract / glycerin in a weight ratio of 1:1:1.

[0123] Pigment Red 254 Pigment designation: Pigment Red 254; CI 56110 Basic colorant tone: red Table 20

[0124] The reflectance curve of the pigment red 254 dispersion processed by the above method is as follows: Figure 6 As shown in Table 21, the CIE LAB values ​​are as follows.

[0125] Table 21

[0126] ¥ Dilute with a dilute solution containing distilled water / witch hazel extract / glycerin in a weight ratio of 1:1:1.

[0127] Pigment Yellow 151 Pigment identification: Pigment Yellow 151; CI 13980 Basic colorant tone: yellow Table 22

[0128] The reflectance curve of the pigment dispersion of Pigment Yellow 151 processed by the above method is as follows: Figure 7 As shown in Table 23, the CIE LAB values ​​are as follows.

[0129] Table 23

[0130] ¥ Dilute with a dilute solution containing distilled water / witch hazel extract / glycerin in a weight ratio of 1:1:1.

[0131] Pigment Yellow 180 Pigment designation: Pigment Yellow 180; CI 21290 Basic colorant tone: yellow Table 24

[0132] The reflectance curve of the pigment yellow 180 pigment dispersion treated by the above method is as follows: Figure 8 As shown in Table 25, the CIE LAB values ​​are as follows.

[0133] Table 25

[0134] ¥ Dilute with a dilute solution containing distilled water / witch hazel extract / glycerin in a weight ratio of 1:1:1.

[0135] Pigment White 6 Pigment identification: Pigment White 6; Titanium Dioxide; CI 77891 Basic colorant tone: white Table 26

[0136] The reflectance curve of the pigment white 6 dispersion processed by the above method is as follows: Figure 9 As shown in Table 27, the CIE LAB values ​​are as follows.

[0137] Table 27

[0138] ¥ Dilute with a dilute solution containing distilled water / witch hazel extract / glycerin in a weight ratio of 1:1:1.

[0139] Pigment Blue 60 Pigment designation: Pigment Blue 60; CI 69800 Basic colorant tone: blue Table 28

[0140] The method described above for processing Pigment Blue 60 pigment dispersions differs in that it utilizes an online high-shear mixer, passing the mixture through a media mill to reduce particle size. The reflectance curve of the Pigment Blue 60 pigment dispersion is shown below. Figure 10 As shown in Table 29, the CIE LAB values ​​are as follows.

[0141] Table 29

[0142] ¥ Dilute with a dilute solution containing distilled water / witch hazel extract / glycerin in a weight ratio of 1:1:1.

[0143] Pigment Blue 16 Pigment designation: Pigment Blue 16; CI 74100 Basic colorant tone: blue Table 30

[0144] The reflectance curve of the Pigment Blue 16 pigment dispersion processed by the above method is as follows: Figure 11 As shown in Table 31, the CIE LAB values ​​are as follows.

[0145] Table 31

[0146] ¥ Dilute with a dilute solution containing distilled water / witch hazel extract / glycerin in a weight ratio of 1:1:1.

[0147] Pigment Green 36 Pigment designation: Pigment Green 36; CI 74265 Basic colorant tone: green Table 32

[0148] The reflectance curve of the pigment green 36 dispersion processed by the above method is as follows: Figure 12 As shown in Table 33, the CIE LAB values ​​are as follows.

[0149] Table 33

[0150] ¥ Dilute with a dilute solution containing distilled water / witch hazel extract / glycerin in a weight ratio of 1:1:1.

[0151] Pigment Green 7 Pigment designation: Pigment Green 7; CI 74260 Basic colorant tone: green Table 34

[0152] The reflectance curve of the pigment green 7 dispersion processed by the above method is as follows: Figure 13 As shown, the CIE LAB values ​​are shown in Table 35.

[0153] Table 35

[0154] ¥ Dilute with a dilute solution containing distilled water / witch hazel extract / glycerin in a weight ratio of 1:1:1.

[0155] Although various aspects and certain preferred embodiments of this disclosure have been described, those skilled in the art will recognize that changes and modifications can be made thereto without departing from the spirit of this disclosure, and it is intended to include all such changes and modifications that fall within the true scope of this disclosure.

Claims

1. A pigment dispersion comprising: a pigment selected from Pigment Blue 16, Pigment Blue 60, Pigment Green 36, Pigment Green 7, or any combination thereof; one or more solvents including a Hamamelis virginiana extract, wherein the one or more solvents further include ethanol and water; a wetting agent including one or more alkyl polyglycosides; an antifoaming agent; and one or more additives selected from: a dispersant, a binder, a humectant, and any combination thereof; wherein the Hamamelis virginiana extract is present in an amount of 10-25 wt% of the total pigment dispersion.

2. The pigment dispersion of claim 1, wherein the one or more alkyl polyglycosides are present in an amount of 1-15 wt% of the total pigment dispersion.

3. The pigment dispersion of claim 1 or 2, further comprising about 1- about 20 wt% of an ammonium acrylate copolymer of the total pigment dispersion.

4. The pigment dispersion of any one of claims 1-3, wherein the one or more additives in the pigment dispersion include a dispersant and a humectant.

5. The pigment dispersion of any one of claims 1-4, wherein the pigment dispersion comprises about 30 wt% to about 60 wt% of the pigment.

6. The pigment dispersion of any one of claims 1-5, wherein the pigment dispersion comprises less than 0.5 ppm of each of: naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benzo[a]anthracene, , benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[ghi]perylene, dibenzo[ah]anthracene, indeno[1,2,3,cd]pyrene, cyclopenta[cd]pyrene, benzo[j]fluoranthene, benzo[e]pyrene, dibenzo[ai]pyrene, dibenzo[a]pyrene, dibenzo[ae]pyrene, benzo[c]fluorene, dibenzo[ah]pyrene, 1 -methylpyrene, and 5-methyl .

7. The pigment dispersion of any one of claims 1-5, comprising one or more of: less than 0.5 ppm of mercury, organometallic tin, antimony, arsenic, cadmium, chromium (Cr(VI)), or any combination thereof; less than 0.7 ppm of lead; less than 5 ppm of nickel; less than 500 ppm of barium; less than 250 ppm of copper; less than 2 ppm of selenium; less than 2000 ppm of zinc; and less than 0.005 ppm of benz[a]pyrene.

8. The pigment dispersion of any one of claims 1-5, wherein the pigment dispersion comprises less than 5 ppm of one or more of the following free aromatic amines: 4- amino biphenyl, benzidine, 4-chloro-o-toluidine, 2-naphthylamine, 4-o-tolylazo-o- toluidine, 5-nitro-o-toluidine, 4-chloroaniline, 4-methoxy-m-phenylenediamine, 4,4'- methylenedianiline, 3,3'-dichlorobenzidine, 3,3'-dimethoxybenzidine, 4,4'-bis-o- toluidine, 4,4'-methylene bis-o-toluidine, 6-methoxy-m-toluidine, 4,4'-methylene bis-(2- chloroaniline), 4-methyl-m-phenylenediamine, o-anisidine, 4-aminoazobenzene, 2- methyl-p-phenylenediamine, 4-amino-3-fluorophenol, 4,4'-oxydianiline, 4,4'- thiodianiline, o-toluidine, 2,4,5-trimethylaniline, p-phenylenediamine, aniline, p- toluidine, p-aminobenzenesulfonic acid, 2,6-dimethylaniline, 6-amino-2- ethoxynaphthalene, and 2,4-dimethylaniline.

9. The pigment dispersion of any one of claims 1-5, wherein the pigment dispersion has a particle size distribution D90 of less than 5 μιη.

10. The pigment dispersion of claim 1, comprising: 20 wt% to 40 wt% of a pigment selected from Pigment Blue 60 of the total dispersion; 1% to 5% by weight of the total dispersion of ethanol; 2% to 10% by weight of the total dispersion of alkyl polyglycoside; optionally wherein the CIE LAB values of the pigment dispersion at 100% (wt / wt) are L* = 17.82, a* = 12.03, and b* = -23.

58.

11. The pigment dispersion of claim 10, wherein the pigment dispersion has a particle size range of about 60 nm to about 15 pm.

12. The pigment dispersion of claim 1, comprising: 20% to 40% by weight of the total dispersion of a pigment selected from Pigment Green 36; 1% to 5% by weight of the total dispersion of ethanol; 2% to 10% by weight of the total dispersion of alkyl polyglycoside; and optionally wherein the CIE LAB values of the pigment dispersion at 100% (wt / wt) are L* = 43.59, a* = -44.07, and b* = 22.

30.

13. The pigment dispersion of claim 12, wherein the pigment dispersion has a particle size range of 60 nm to 10 pm.

14. A tattoo ink formulation comprising the pigment dispersion of any one of claims 1-13.

15. A method of making the pigment dispersion of any one of claims 1-13, comprising mixing the pigment, one or more solvents, and one or more additives using an in-line high shear mixer at a speed of about 1,000 feet per minute to about 20,000 feet per minute for a time of about 30 minutes to about 4 hours.

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