Hollow particle ink composition

Abstract

A composition for writing instruments that provides an opaque and durable application comprises a unique combination of hollow particulate components, colorants, viscosity modifiers, humectants, and optional dispersants, which produces shear-thinning properties.

Description

[0001] Cross-references

[0002] This application claims priority to U.S. Provisional Patent Application No. 63 / 599,281, filed November 15, 2023, the disclosure of which is incorporated herein by reference. Technical Field

[0003] This disclosure generally relates to compositions for writing instruments that provide opaque and durable applications. More specifically, this disclosure provides compositions comprising a unique combination of hollow particulate components, colorants, viscosity modifiers, humectants, and optionally dispersants. The composition has high surface tension, resulting in reduced permeation to porous substrates. Furthermore, the composition exhibits shear-thinning behavior, such that the composition has a first structure and a first viscosity in a non-shear state, and a second structure and a second viscosity in a shear state. In fact, the compositions of this disclosure have a structure that reversibly decomposes upon application of stress and subsequent stress relief. This disclosure also relates to writing instruments comprising the above-described compositions. Background Technology

[0004] Numerous studies have been conducted on opaque writing systems. However, such systems are not entirely opaque and / or require a considerable amount of time to develop color. In fact, due to the very small particle size of conventional opaque pigments, the pigment particles often settle into porous substrates, resulting in compromised opacity. Furthermore, water-based formulations with enhanced opacity often lack ink durability. Therefore, it is desirable to provide a highly opaque ink formulation that can remain on the substrate surface to provide opacity. U.S. Patent Publication No. 2020 / 0255680 attempts to address the issues of opacity and durability through an ink formulation containing a solvent, a polymer-based hollow particle component, a resin, a colorant, and a humectant. This Newtonian-type ink formulation is designed for conventional filter reservoir-nib writing instrument systems (i.e., markers) and has a low viscosity, for example, less than about 50 cP, so that the ink can flow through the fibers in the reservoir and nib. Furthermore, the resin in the ink formulation is used to impart durability and adhesion to the substrate.

[0005] In addition, conventional opaque ink compositions may include white pigments to increase the opacity of the ink composition. Traditionally, titanium dioxide has been used as a white pigment. However, titanium dioxide can be expensive. Furthermore, excessive white pigment can cause the ink composition to exhibit an undesirable pale or soft color.

[0006] Therefore, despite progress in opacity and durability, there remains a need for an improved opaque composition that exhibits shear-thinning properties, can be applied with a ballpoint pen tip, primarily remains on the substrate surface, presents the same appearance regardless of the color and porosity of the underlying substrate, and is inherently durable. In this regard, ink compositions capable of producing high-quality opaque markings after application to various substrates with a ballpoint pen tip would be advantageous. Furthermore, ink compositions with a short time delay in opacity development would be beneficial.

[0007] Furthermore, ink compositions capable of achieving the desired opacity with less white pigment would be advantageous compared to conventional ink systems.

[0008] Therefore, this disclosure provides compositions for writing instruments and writing instruments containing such compositions, which allow for a stable and durable writing effect. Summary of the Invention

[0009] The above and other problems are solved by the following inventions, but it should be understood that not every embodiment of the inventions described herein will solve every problem described above.

[0010] This disclosure provides compositions for imparting opaque markings to a desired substrate. The composition comprises at least one hollow particulate component, a colorant, a viscosity modifier, a humectant, and optionally a dispersant. The ink has a relatively high surface tension, which helps reduce penetration into the porous substrate. The composition can be substantially opaque.

[0011] Another embodiment of this disclosure provides a writing instrument comprising a writing tool capable of applying a composition to a substrate. In some embodiments, the composition is contained in an ink reservoir of the writing instrument. The writing instrument is selected from the group consisting of ballpoint pens, rollerball pens, and gel pens.

[0012] This disclosure also relates to a durable ink composition comprising: a hollow particle component; a first colorant; a viscosity modifier; a humectant; and a solvent. In some embodiments, the composition further comprises a dispersant present in an amount of about 2 to about 20% by weight based on the total weight of the composition. In other embodiments, the viscosity modifier is present in an amount of about 1 to about 10% by weight based on the total weight of the composition.

[0013] In some aspects, the hollow particle component is a polymer hollow particle. The hollow particle includes an outer layer or shell containing an aqueous solution. In some embodiments, the ink composition achieves substantial opacity when the aqueous solution evaporates from the hollow particle, leaving behind a shell designed to reflect light.

[0014] In some embodiments, the compositions disclosed herein include more than one colorant. Therefore, the composition may include a first colorant and a second colorant. The first colorant and the second colorant may be different colors. Each of the first colorant and the second colorant may be independently selected from pigments and dyes. Attached Figure Description

[0015] Additional features and advantages of the invention will become apparent from the following detailed description, which is provided in conjunction with the accompanying drawings:

[0016] Figure 1 It is a writing tool according to the embodiments of this disclosure.

[0017] Figure 2 This is a comparison ratio of the ink of this invention with a control ink when writing on black paper. Detailed Implementation

[0018] This disclosure relates to compositions that can be used to produce substantially opaque inks. More specifically, this disclosure relates to compositions comprising hollow particulate components, colorants, viscosity modifiers, humectants, and optionally dispersants. These compositions can be used to fill writing instruments, and the applied marks are substantially opaque regardless of the underlying substrate.

[0019] definition

[0020] For the purposes of this disclosure, the following terms are defined as follows:

[0021] "Opacity" refers to the amount of visible light that an ink coating allows to pass through. Therefore, "partial opacity" means that the ink does not completely block the transmission of radiant energy. "Substantial opacity" means that the pigment (or a composition containing a pigment) is substantially opaque to visible light when applied to a substrate.

[0022] "Pigment" refers to finely ground color particles suspended in a dispersant or carrier. Specifically, pigments are colored, typically inorganic compounds, and are completely or almost insoluble in water. Furthermore, pigments can be applied to a substrate surface, allowing them to physically bond with the substrate.

[0023] "Dye" refers to a chemical that dissolves in water or other liquid media to produce a colorant. In particular, dyes can be organic soluble compounds. Furthermore, dyes can be physically or chemically bonded to a substrate to become part of the substrate.

[0024] Composition

[0025] The compositions disclosed herein comprise hollow particulate components, at least one colorant, a viscosity modifier, a humectant, and optionally a dispersant. Detailed information regarding each component and the resulting compositions is provided below.

[0026] Hollow particle components

[0027] The hollow particle component can be polymer hollow particles. The hollow particles may include a shell or outer layer composed of a polymer and an internal liquid. In some embodiments, the internal liquid may be an aqueous solution. In other embodiments, the internal liquid may be an opaque pigment.

[0028] Hollow particulate components can provide at least partial opacity when filled with an internal liquid and / or in the absence of an internal liquid. For example, in some embodiments, the hollow particulate component achieves substantial opacity when an outer layer of the hollow particulate component remains after the internal liquid evaporates. The outer layer can scatter and reflect light to achieve opacity.

[0029] As mentioned above, conventional ink compositions can achieve opacity using white pigments. However, due to the reflective properties of the outer layer of the hollow particle component, less pigment may be required in the ink composition to achieve the desired level of opacity. Therefore, ink compositions containing hollow particle components can achieve the same or higher opacity compared to conventional ink compositions, but using less white pigment. This can reduce the overall cost of the ink composition. Furthermore, since one or more colorants contained in the ink composition can contain less white pigment that might darken or alter the color, it is easier to achieve the desired color in the ink composition. Therefore, brighter, more realistic colors can be achieved.

[0030] Hollow particle components can be provided in the form of organic compounds. Therefore, compared to inorganic pigments, hollow particle components are more likely to remain on porous substrates. In other words, hollow particle components exhibit high retention, i.e., they do not penetrate into the substrate. Without being constrained by any particular theory, the surface energy / tension, particle size and narrow particle size distribution, and agglomeration ability of hollow particle components may provide high retention, particularly when combined with other ink composition components discussed herein, such as solvents (e.g., water) and humectants. Retention can be expressed by the surface energy / tension of the hollow particle component and the resulting ink composition. The hollow particle component then imparts these benefits to the ink composition when used in the ink composition embodiments disclosed herein. In some embodiments, the surface tension of the hollow particle component is at least about 20 mN / m (millineutons per meter). In other embodiments, the surface tension of the hollow particle component is about 20 mN / m to about 65 mN / m. In still other embodiments, the surface tension of the hollow particle component is about 45 mN / m to about 60 mN / m.

[0031] The average particle size of the hollow particle component can be at least about 0.1 micrometers. In one embodiment, the average particle size of the hollow particle component is about 1 micrometer or greater. In another embodiment, the average particle size is about 3 micrometers or greater. For example, the average particle size of the hollow particle component can range from about 0.15 micrometers to about 20 micrometers. In some embodiments, the average particle size of the hollow particle component is from about 0.4 micrometers to about 15 micrometers. In other embodiments, the average particle size of the hollow particle component is from about 1 micrometer to about 10 micrometers.

[0032] Applicable commercially available hollow particle components include, but are not limited to: Ropaque from Dow Chemicals (Michigan, USA). TM Series (e.g., Ropaque) TM Ultra, Ropaque TM Ultra EF, Ropaque TM OP-96, Ropaque TM Dual et al.); Joncryl from BASF (Germany) ® 633; Celecor from Arkema (Germany) ® and Celecor ® AF; E-cryl from Emulsion Systems (Florida, USA) ® 11; Acusol from Dow ® Series (e.g., Acusol) ® OP301, Acusol ® OP302B, Acusol ® OP303 and Acusol ® OP305); Orgal from Organikkimya (Türkiye) TM OPAC-101; WoodPlus from Woodplus (USA) TM PS Opaque; Hique 821 from HukuLattice; and combinations thereof. In some embodiments, the hollow particle component is a hybrid hollow particle component, i.e., a mixture of inorganic pigments and organic polymers. Non-limiting examples include pigments from Heubach GmbH (Germany) and the “TA” and “TR” series from Chuzhou Grea Minerals (China).

[0033] The hollow particle component in the composition may be at least about 5% by weight based on the total weight of the composition. In some embodiments, the hollow particle component is about 10% or more (based on the total weight of the composition). In other embodiments, the hollow particle component is about 15% or more (based on the total weight of the composition). In still other embodiments, the hollow particle component is about 15% to about 55% by weight based on the total weight of the composition. In one example, the composition comprises about 25% to about 90% of the hollow particle component based on the total weight of the composition. In another example, the hollow particle component is present in an amount of about 20 to about 40% by weight based on the total weight of the composition. In this respect, the composition may comprise about 25% to about 35% by weight of the hollow particle component (based on the total weight of the composition).

[0034] solvent

[0035] In some embodiments, the hollow particle component provides a degree of opacity in the presence of one or more solvents. In this regard, the hollow particle component provides at least about 50% opacity in the presence of a solvent. In some embodiments, the hollow particle component provides at least about 60% opacity in the presence of a solvent. In other embodiments, the hollow particle component provides at least about 70% opacity in the presence of a solvent. The opacity can be measured using a reflective or transmissive densitometer. In some embodiments, the hollow particle component achieves substantial opacity in the absence of a solvent.

[0036] In some embodiments, substantial opacity can mean that at least about 90 percent of light is blocked / blocked by the hollow particulate component. In other embodiments, substantial opacity means that at least 95 percent of light is blocked through the ink coating. In still other embodiments, substantial opacity means that at least 98 percent of light is blocked through the ink coating. In yet another embodiment, substantial opacity means that at least about 99 percent of light is blocked through the ink coating. In still other embodiments, the hollow particulate component achieves complete opacity in the absence of a solvent. In this respect, the hollow particulate component can block about 100 percent of light from passing through the ink coating.

[0037] Solvents suitable for the compositions disclosed herein include those capable of dissolving and / or suspending the components discussed herein. Furthermore, suitable solvents can impart high surface tension to the composition to reduce interfacial penetration.

[0038] The composition may include a single solvent or a mixture of solvents. And, although the surface tension range will be discussed in more detail below, in some embodiments, the solvent is chosen such that the composition has a surface tension of about 20 mN / m or higher. In one embodiment, the solvent is chosen such that the composition has a surface tension of about 25 mN / m or higher. In some embodiments, the solvent has a surface tension of about 40 mN / m or higher at room temperature. In other embodiments, the surface tension of the solvent is from about 40 mN / m to about 75 mN / m. For example, the surface tension of the solvent may be from about 45 mN / m to about 75 mN / m.

[0039] Non-limiting examples of solvents suitable for the compositions disclosed herein include water, ethylene glycols (such as glycerol, propylene glycol, polyalkylene glycols, and glycols), ethylene glycol ethers, poly(glycol) ethers, caprolactam, formamide, acetamide, and long-chain alcohols. In some embodiments, the solvent may include primary aliphatic alcohols with fewer than 30 carbon atoms, primary aromatic alcohols with fewer than 30 carbon atoms, secondary aliphatic alcohols with fewer than 30 carbon atoms, secondary aromatic alcohols with fewer than 30 carbon atoms, 1,2-ols with fewer than 30 carbon atoms, 1,3-ols with fewer than 30 carbon atoms, terminal alcohols with fewer than 30 carbon atoms, ethylene glycol alkyl ethers, propylene glycol alkyl ethers, poly(ethylene glycol) alkyl ethers, higher homologues of poly(ethylene glycol) alkyl ethers, poly(propylene glycol) alkyl ethers, higher homologues of poly(propylene glycol) alkyl ethers, N-alkylcaprolactam, unsubstituted caprolactam, substituted formamide, unsubstituted formamide, substituted acetamide, unsubstituted acetamide, and combinations thereof.

[0040] In this regard, suitable solvents include proton polar solvents and non-proton polar solvents. Suitable proton polar solvents include, but are not limited to, water, glycerol, propylene glycol, diethylene glycol, ethers (such as dipropylene glycol monoether), and combinations thereof. Suitable non-proton polar solvents include, but are not limited to, dimethyl sulfoxide, dimethylacetamide, dimethylformamide, formamide, N-methylpyrrolidone, N-methylmorpholine, propylene carbonate, ethylene carbonate, and combinations thereof. In some embodiments, low-odor solvents such as water, ethylene glycol, and combinations thereof may be used.

[0041] When the composition includes a solvent system having multiple solvents, the first solvent can be any of the solvents mentioned above, and the second solvent (or co-solvent) can include, but is not limited to, N-methylpyrrolidone, 1,5-pentanediol, 2-pyrrolidone, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,3-(2-methyl)propanediol, 1,3,5-(2-methyl)pentanetriol, tetramethylene sulfoxide, 3-methoxy-3-methylbutanol, glycerol, 1,2-alkyldiol, and combinations thereof.

[0042] The solvent concentration can range from about 10 to about 60% by weight based on the total weight of the composition. In one embodiment, the composition comprises about 15 to about 55% by weight of solvent based on the total weight of the composition. In this respect, the total amount of solvent (with or without co-solvents) can be about 20 to about 50% by weight of the composition. For example, the total amount of solvent (with or without co-solvents) can range from about 25 to about 45% by weight of the composition. In one embodiment, the composition may comprise about 30 to about 40% by weight of solvent (based on the total weight of the composition).

[0043] Colorant

[0044] The compositions disclosed herein include a colorant that, when used in combination with the hollow particle component, displays its color or promotes the display of other colors. Without being bound by any particular theory, the combined use of the hollow particle component and the colorant can reduce the time delay in the development of opacity in the ink composition.

[0045] In some embodiments, the colorant used in the compositions of this disclosure is white. In this regard, suitable first colorants include, but are not limited to, titanium dioxide, zinc oxide, calcium carbonate, zinc sulfide, zinc barium white, hydrated alumina, calcium carbonate, barium sulfate, barite, talc, silicon dioxide, kaolin, and combinations thereof.

[0046] In some embodiments, the colorant is not white. The non-white colorant may be provided in the form of an inorganic pigment. In other embodiments, the non-white colorant is provided in the form of an organic pigment. Organic pigments may also be used as suitable first colorants conforming to this disclosure, provided they have a suitable particle size and appropriate lattice structure. Specifically, a suitable lattice structure provides atomically separated layers spaced to maximize or provide high internal light reflection. In some embodiments, the non-white colorant is a pigment. The pigment may be added as a dry pigment and dispersed in a specified solvent matrix.

[0047] In this regard, applicable blue pigments include, but are not limited to, Palomar from Bayer Corp. (RockHill, South Carolina). ® Blue B-4810 PB 15:3, Palomar ® Blue B-4710 PB 15:1 and Palomar ® Blue B-4900 pigment; and Sunfas from Sun Chemical Corp. (Cincinnati, Ohio). TM Blue15:3 pressed cakes and Sunfast TM Blue 15:3 powder.

[0048] Suitable red pigments include, but are not limited to: magenta pigments from Bayer Corp., such as Quindo. ® Magenta RV-6828 Pigment Red 122, Quindo ® Magenta RV-6831 Pigment Red 122 (pressed), Quindo ® Red R-6713 PV 19 and Quindo ® Magenta RV-6843 Pigment Red 202 Pigment; and Sunfast from Sun Chemical Corp. TM Magenta 122 and Sunfast TM Magenta 202 pigment.

[0049] Suitable yellow pigments include, but are not limited to: Fanchon from Bayer Corp. ® Fast Y-5700 PY139 and Fanchon ® Fast Yellow Y-5688 CI Pigment Yellow 150 Pigment; from Sunbrite, Sun Chemical Corp. ® Yellow 14 biscuits and Spectra Pac Yellow 83 pigment; from Sandorin, Clariant Corp. (Charlotte, North Carolina). TM Yellow 6GL; and Irgazin from Ciba Geigy. ® Yellow2RLT PY 110、Irgazin ® Yellow 2GLTN PY 109, Irgazin ® Yellow 2GLTE PY 109 and Irgazin ® Yellow 3RLTN PY 110 pigment.

[0050] Applicable green pigments include, but are not limited to, copper phthalocyanine green pigments, such as Pigment Green 1, Pigment Green 2, Pigment Green 7 and Pigment Green 36, and mixtures thereof.

[0051] Purple colorants include, but are not limited to, quinacridone, benzimidazole, and mixtures thereof. Purple colorants include, but are not limited to, Pigment Violet 19, Pigment Violet 3, Pigment Violet 32, and Pigment Violet 23, and mixtures thereof.

[0052] Orange colorants include, but are not limited to, β-naphthol pigments, naphthol red pigments or combinations thereof, as well as Pigment Orange 5, Pigment Red 17, Pigment Red 188, Pigment Orange 62, Pigment Red 112, Pigment Red 255, Pigment Red 264 and Pigment Red 49:2, and mixtures thereof.

[0053] Applicable black pigments include, but are not limited to, carbon black, such as Special Black 4, Special Black 5, Special Black 6, Special Black 4A, Color Black FW 200 and Color Black FW2 pigments (from Degussa Corporation, Ridgefield, New Jersey); Raven 1200 carbon black, Raven 1170 carbon black, Raven 3500 carbon black and Raven 5750 carbon black pigments (from Columbia Chemical Corp., Atlanta, Georgia); Mogul L carbon black and Sterling NS carbon black pigments (from Cabot Corp., Boston, Massachusetts); and Carbon Black MA-100 pigment (from Mitsubishi Chemical Corporation, Tokyo, Japan).

[0054] If the colorant is a pigment, the average particle size (average diameter) of the colorant is about 0.5 micrometers or greater. In some embodiments, the particle size is about 2 micrometers or greater. In other embodiments, the average particle size is about 4 micrometers or greater. Without being constrained by any particular theory, this particle size range can prevent the colorant from darkening because the colorant may not be absorbed by the pores of the substrate. In some aspects, the average particle size of the colorant is from about 0.5 micrometers to about 200 micrometers. In other aspects, the average particle size of the colorant is from about 5 micrometers to about 200 micrometers. For example, the average particle size range of the colorant can be from about 5 micrometers to about 50 micrometers. Again, the average particle size of the colorant can be from about 25 micrometers to about 150 micrometers. In other aspects, the average particle size of the colorant is from about 50 micrometers to about 1000 micrometers. For example, the average particle size of the colorant can be from about 250 micrometers to about 750 micrometers.

[0055] If the colorant is a pigment, the pigment can be first dispersed in a suitable solvent to form a pigment dispersion before being added to the composition. Examples of such dispersions include, but are not limited to, the Tint-Ayd aqueous dispersion series from Elementis and Levanyl from Lanxess (Germany). ®The series includes Hostafine from Heubech-Clariant (Germany), Neotint from Milliken (Spartaburg, South Carolina), aqueous pigment dispersions from Chromatech (Canton, Michigan), Chromachem 896 from Chromaflo (Ashtabila, Ohio), and combinations thereof. In other embodiments, the pigment may be in a formulation that is readily dispersible upon contact with a suitable solvent. Examples of such formulations include, but are not limited to, the xFast and Microlith series from BASF (Germany) and the Agrocer series from Clariant (Germany).

[0056] Suitable colorants may also include dyes capable of adhering to opaque particulate surfaces and providing color when written on dark porous substrates. Examples of such dyes include, but are not limited to, Victoria Blue, Basic Red 14, Basic Yellow 49, Basic Red 15, and combinations thereof. In some embodiments, the dye is liquid, such as Fisco from Orient (USA). ® Pink 664 and Fisco ® Blue, and Intrabond from Sensient (St. Louis, Missouri) ® Pink BR200.

[0057] As will be understood by those skilled in the art, the concentration of the colorant should depend on the application and the desired color. However, typically, the composition comprises about 5% to about 30% of the colorant based on the total weight of the composition. In one embodiment, the amount of colorant included in the composition is within the following ranges: a lower limit of about 5%, about 7%, about 9%, about 11%, 13%, or about 15%, and an upper limit of about 20%, about 22%, about 24%, about 26%, about 28%, or about 30%. For example, the content of the colorant in the composition may be about 5% to about 25% based on the total weight of the composition. In another example, the composition comprises about 7% to about 20% of the colorant based on the total weight of the composition. In yet another example, the content of the colorant in the composition is about 8% to about 15% based on the total weight of the composition.

[0058] Furthermore, the compositions disclosed herein may include one or more additional colorants to enhance or alter the color of the ink composition. Therefore, in embodiments containing more than one colorant, one colorant may be referred to as a first colorant, and the other colorants may be referred to as second, third, fourth, etc., colorants. Additional colorants may be provided in the same form as the first colorant. However, additional colorants may have a different color than the first colorant.

[0059] When included, the composition may contain additional colorant in an amount from about 0.5% to about 20% by weight based on the total weight of the composition. In one embodiment, the content of additional colorant in the composition is within the following ranges: a lower limit of about 1%, about 2%, about 3%, about 4%, or about 5%, and an upper limit of about 8%, about 10%, about 12%, about 14%, about 16%, about 18%, or about 20%. For example, the content of additional colorant in the composition may be from about 2% to about 20% by weight based on the total weight of the composition. In another example, the composition includes about 4% to about 18% of additional colorant based on the total weight of the composition. In yet another example, the content of additional colorant in the composition is from about 5% to about 15% by weight based on the total weight of the composition.

[0060] Viscosity modifier

[0061] The compositions disclosed herein may include viscosity modifiers, such as thickeners. Without being bound by any particular theory, viscosity modifiers impart shear-thinning properties to the ink compositions, thereby giving the ink compositions a higher viscosity before application to a substrate than after application. In other words, due to the action of the thickener, when shear forces are applied, the hydrogen bond network in the composition may break—that is, when the ball in the tip of a ballpoint writing instrument begins to rotate, the thermal bonds break, thereby reducing the viscosity of the composition. When the ball stops rotating, the hydrogen bond network reforms, and the viscosity of the composition returns to its previous non-shear value, preventing leakage of the composition from the writing instrument. The shear-thinning properties imparted to the ink compositions also contribute to the composition's ability to remain on the substrate surface, thus imparting maximum opacity.

[0062] Viscosity modifiers suitable for the compositions disclosed herein include materials suitable for topical application, compatible with other components in the composition, and having thickening properties of the composition. In this regard, silica, clay, and combinations thereof can be used as viscosity modifiers in the composition. However, without being bound by any particular theory, it is considered that a particular viscosity modifier can allow for minimal sedimentation. In this regard, in some embodiments, the viscosity modifier can be a solid lubricating material with a melting point of at least about 40°C. Non-limiting examples of solid lubricating materials suitable for the compositions disclosed herein include C. 14 -C 40Fatty alcohols, polyethylene, alkyl (C 18 -C 45 Methylsiloxane, jojoba ester wax, hydrogenated vegetable oil and mixtures thereof.

[0063] For example, the viscosity modifier used in the compositions disclosed herein may be selected from high-melting-point and / or low-melting-point waxes and mixtures of such waxes. Suitable high-melting-point waxes (66-101°C) include, but are not limited to, beeswax, lignite wax, ceresin wax, paraffin wax, hydrogenated castor oil, and C 26 -C 40 Straight-chain alcohols and combinations thereof. Suitable low-melting-point waxes (40-65°C) include, but are not limited to, C. 14 -C 25 Fatty alcohols, fatty esters, fatty amides, especially stearyl alcohol, hexadecyl alcohol, stearic acid, polydimethylsiloxane beeswax, and combinations thereof. In one embodiment, the thickener is C. 16 -C 22 Fatty acids and / or fatty alcohols.

[0064] In some embodiments, the viscosity modifier is octadecanol, hydrogenated castor oil, or a mixture thereof. In other embodiments, the viscosity modifier includes mineral oil, petrolatum, or a mixture thereof.

[0065] When the composition contains an aqueous medium, the viscosity modifier may be selected from non-thixotropic hydrophilic viscosity modifiers. In this regard, suitable hydrophilic viscosity modifiers may include, but are not limited to, water-soluble cellulose viscosity modifiers, guar gum, quaternized guar gum, nonionic guar gum containing C1-C6 hydroxyalkyl groups, xanthan gum, carob gum, stearin, gellan gum, rhamnose and caralamen, alginate, maltodextrin, starch and its derivatives, hyaluronic acid and its salts, polyglycerol (meth)acrylate polymers, polyvinylpyrrolidone, polyvinyl alcohol, crosslinked polymers and copolymers of acrylamide, associative polymers (such as associative polyurethanes) and mixtures thereof.

[0066] The viscosity modifier may be present in the composition at a rate of about 0.5% to about 25% by weight (based on the total weight of the composition). In some embodiments, the viscosity modifier may be present in the composition at a rate of about 1% to about 15% by weight or about 1% to about 10% by weight based on the total weight of the composition. In other embodiments, the viscosity modifier may be present in the composition of the present invention at a rate of about 2% to about 10% by weight based on the total weight of the composition.

[0067] Moisturizer

[0068] One of the challenges of using water in ink compositions for durable applications is that the ink cannot regain its fluidity after drying. This is especially true when writing instruments include retractable bodies, where the pen tip may remain exposed between / after use. Without being bound by any particular theory, including a suitable humectant in the composition may help avoid such problems. In some embodiments, the humectant used in the compositions of this disclosure comprises an organic material miscible with water.

[0069] In this regard, suitable humectants include, but are not limited to, simple polyols, oligomeric and polymeric polyols (such as polyethers or polyesters), and combinations thereof. Examples of such alcohols include, but are not limited to, polyethylene glycol, polypropylene glycol, poly(tetramethylene ether) glycol, and combinations thereof. In some embodiments, the humectant is polyethylene glycol. Commercially available alcohols that can be used as humectants include Pluracol P series from BASF (Germany) and Voranol P400 from Dow Chemicals (Michigan, USA).

[0070] Other available suitable moisturizers, in a non-exhaustive list, include ethylene glycol, propylene glycol, diethylene glycol, glycerin, dipropylene glycol, sorbitol, amides, urea, substituted ureas, ethers, carboxylic acids, esters, alcohols, organosulfides, organosulfoxides, sulfones (such as sulfolane), alcohol derivatives, carbitol, butyl carbitol, cellolytic agents, ether derivatives, amino alcohols, ketones, N-methylpyrrolidone, 2-pyrrolidone, cyclohexylpyrrolidone, hydroxy ethers, amides, sulfoxides, lactones, and other water-miscible materials, as well as mixtures thereof.

[0071] The humectant in the compositions disclosed herein can be any effective amount. In some embodiments, the water-to-organic ratio is from about 100:0 to about 30:70. In other embodiments, the water-to-organic ratio is from about 97:3 to about 50:50. In still other embodiments, the water-to-organic ratio is from about 90:10 to about 70:30.

[0072] The concentration of the humectant can range from about 5 to about 30% by weight based on the total weight of the composition. In one embodiment, the composition comprises about 10 to about 25% by weight of the humectant based on the total weight of the composition. In this respect, the total amount of the humectant can be about 10 to about 20% by weight of the composition. For example, the total amount of the humectant can range from about 12 to about 18% by weight of the composition.

[0073] Additives and fillers

[0074] Other additives may be added to the composition to further enhance its physical properties. In some embodiments, the compositions of the present invention comprise about 0.1 to about 5% by weight of additives. In other embodiments, the compositions comprise about 0.5 to about 3% by weight of additives. In this regard, suitable additives include, but are not limited to, humectants, surfactants, bactericides, antimicrobials, fungicides, rheology modifiers and processing aids, dispersants, defoamers, cosolvents, additional colorants, heat stabilizers, fragrances, glitter, lubricants, plasticizers, preservatives, optical brighteners, antioxidants, and combinations thereof.

[0075] For example, according to the present invention, one or more preservatives (such as antibacterial agents and fungicides) may be added to extend the shelf life of the composition. Non-limiting examples of suitable preservatives include Fungitrol. ® 940, Kathon ® LX, Nuosept ® 95. Acticide ® LA and Polyphase ® P100. Non-limiting examples of applicable processing aids include Hydropalat. ® 44. Lubricants or plasticizers (such as oleic acid, isobutyl stearate, polyoxyethylene alkali metal salts, dicarboxylic acid amides, phosphate esters, etc.) can be added to soften the composition and improve the transfer of colorants to the substrate. Anionic surfactants, nonionic surfactants, etc., can be used as surfactants.

[0076] Rheology modifiers may also be added to the compositions of this disclosure to adjust the pseudoplastic flow state, making the composition suitable for use in writing instruments. Non-limiting examples include alkali metal salts, amine salts, alkanolamine salts of crosslinked acrylic polymers, viscosity modifiers for associating urethane resins, and combinations thereof. If used, the amount of rheology modifier may be from about 0.01 weight percent to about 5 weight percent based on the total weight of the composition. In one embodiment, the composition comprises from about 0.1 weight percent to about 5 weight percent (based on the total weight of the composition).

[0077] The composition may also include fillers. Examples of suitable, non-limiting fillers include glass (e.g., glass sheets, ground glass, and microglass), mica, and combinations thereof. Metal oxide and metal sulfate fillers are also considered for inclusion in the composition. Suitable metal fillers include particles, powders, flakes, and fibers of, for example, copper, steel, brass, tungsten, titanium, aluminum, magnesium, molybdenum, cobalt, nickel, iron, lead, tin, zinc, barium, bismuth, bronze, silver, gold, and platinum, as well as alloys and combinations thereof. Suitable metal oxide fillers include, for example, zinc oxide, iron oxide, aluminum oxide, titanium oxide, magnesium oxide, and zirconium oxide. Suitable metal sulfate fillers include, for example, barium sulfate and strontium sulfate.

[0078] In some embodiments, the compositions of this disclosure include colored fillers with a particle size of about 1 micrometer or larger. For example, suitable colored fillers may have a particle size of about 2 micrometers to about 20 micrometers. In one embodiment, suitable colored fillers have a particle size of about 2 micrometers to about 10 micrometers. In another embodiment, suitable colored fillers have a particle size of about 2 micrometers to about 8 micrometers.

[0079] When included, the filler content may be based on about 1 to about 25% by weight of the total composition. In one embodiment, the composition includes at least one filler in an amount of about 5 to about 20 parts or about 8 to about 15 parts by weight per 100 parts of the total composition. In another embodiment, the composition includes at least one filler in an amount of about 8 to about 14 parts or about 10 to about 12 parts by weight per 100 parts of the total composition. In yet another embodiment, the composition includes at least one filler in an amount of about 10 to about 17 parts or about 12 to about 15 parts by weight per 100 parts of the total composition. In another embodiment, the composition includes at least one filler in an amount of about 10 to about 16 parts or about 12 to about 15 parts by weight per 100 parts of the total composition. In yet another embodiment, the composition includes at least one filler in an amount of about 12 to about 18 parts or about 14 to about 16 parts by weight per 100 parts of the total composition.

[0080] In some embodiments, the composition may contain more than one type of additive and / or filler. For example, the composition may include a first filler in an amount of about 5 to about 20 parts or about 8 to about 17 parts by weight per 100 parts of total rubber, and a second filler in an amount of about 1 to about 10 parts or about 3 to about 7 parts by weight per 100 parts of total composition. In another example, the composition may include a first filler in an amount of about 7 to about 13 parts or about 9 to about 12 parts by weight per 100 parts of total composition, and a second filler in an amount of about 2 to about 8 parts or about 4 to about 6 parts by weight per 100 parts of total composition. In yet another example, the composition may include a first filler in an amount of about 10 to about 15 parts or about 13 to about 14 parts by weight per 100 parts of total composition, and a second filler in an amount of about 2 to about 9 parts or about 3 to about 7 parts by weight per 100 parts of total composition. In another example, the composition may include a first filler in an amount of about 10 to about 15 parts or about 13 to about 14 parts by weight per 100 parts of the total composition, and a second filler in an amount of about 13 to about 18 parts or about 14 to about 16 parts by weight per 100 parts of the total composition.

[0081] performance

[0082] The compositions disclosed herein offer numerous advantages over conventional opaque ink compositions. In this respect, the compositions of this disclosure can be substantially opaque on a range of substrates, including semi-porous and porous substrates, as well as colored and colorless substrates. Furthermore, the durability of the compositions can also be achieved on a range of substrates. For the purposes of this disclosure, the terms "durable" or "durable" refer to the ability of the composition to adhere to a variety of substrates without being removed by simple rubbing. Indeed, unlike other ink compositions that claim to be opaque and durable, the compositions of this disclosure, once applied, provide a substantially opaque mark / color that cannot be removed by simple rubbing.

[0083] Surface tension

[0084] The compositions of the present invention preferably have a surface tension sufficient to prevent penetration into the substrate. In this regard, the surface tension of the composition can be about 20 mN / m or higher. In some embodiments, the surface tension of the composition is about 25 mN / m or higher. In other embodiments, the surface tension of the composition is about 40 mN / m or higher. In still other embodiments, the surface tension of the composition is about 75 mN / m or lower. In yet another embodiment, the surface tension of the composition is about 70 mN / m or lower. For example, the surface tension of the composition can be about 25 mN / m to about 70 mN / m, about 40 mN / m to about 75 mN / m, 45 mN / m to about 65 mN / m, and any other range included herein.

[0085] Viscosity

[0086] The viscosity of the compositions disclosed herein decreases with increasing shear stress. In other words, the viscosity of the compositions disclosed herein in a non-shear state (i.e., before application) differs from the viscosity in a shear state (i.e., when the composition is applied and the ball at the pen tip is spinning). In this respect, the non-shear viscosity is greater than the shear viscosity. In some embodiments, the non-shear viscosity is at least about 1000 times greater than the shear viscosity.

[0087] color development time

[0088] The compositions disclosed herein have a color development time, i.e., the time between the first application (placement) of the color onto the substrate and the first visual indication of the color, lasting from about 0.1 seconds to about 15 seconds. In some embodiments, the color development time of the composition is from about 0.1 seconds to about 10 seconds. In other embodiments, the color development time of the composition is from about 0.25 seconds to about 5 seconds.

[0089] Writing instruments

[0090] Various types of writing instruments (including, but not limited to, ballpoint pens, rollerball pens, and gel pens) can be filled with the compositions of this disclosure. In some embodiments, the compositions of this disclosure can be used in writing instruments comprising an ink reservoir and a pen tip connected to one end of the ink reservoir for conveying the compositions of this disclosure. The ink reservoir and the pen tip can be directly connected or connected via a connector. For example, as... Figure 1 As shown, the writing instrument may include a pen body 110, a pen tip 120, and a connector 130. The pen body 110 may include a storage chamber filled with the composition of the present disclosure. In one embodiment, the pen tip is retractable. In another embodiment, the pen tip is not retractable, but the writing instrument includes a pen cap to prevent the pen tip from drying out.

[0091] Example

[0092] The present invention is further illustrated by the following embodiments. It should be understood that the following embodiments are for illustrative purposes only. These embodiments should not be construed as limiting the scope of the invention.

[0093] The following examples provide compositions formed according to this disclosure. These examples provide the components contained in each composition. Unless otherwise stated, the concentration of each component is provided in parts by weight per 100 parts of total composition.

[0094] Invention Examples 1-3: Compositions and Their Applications

[0095] Three inventive examples (i.e., Examples 1-3) and two comparative examples (i.e., Comparative Examples AB) were prepared according to Table 1 below. The composition components of each example in Table 1 were mixed until a homogeneous mixture was obtained.

[0096]

[0097] Add the homogeneous mixture to the Sharpie assembly. ® In the refill ink chamber of the gel pen. Apply the homogeneous mixture to porous black paper and visually assess the opacity of the lines.

[0098]

[0099] As shown in Table 2, the embodiments of the present invention (i.e., the compositions prepared according to this disclosure) exhibit bright, opaque lines within less than 2 seconds after application to a porous black substrate. In contrast, Comparative Examples AB lack opacity. In fact, the pigment in Comparative Example A penetrates into the paper, exhibiting only weak lines even after 30 seconds. Comparative Example B shows a time delay of more than 30 seconds in color display. In short, compared to the prior art, the comparative ink formulations differ from those prepared according to this disclosure, and the compositions of this disclosure provide opaque and instantly color-developing markings.

[0100] Invention Example 4-X: Composition and its Application

[0101] Three embodiments of the invention (i.e., Embodiments 1-3) and two comparative examples (i.e., Comparative Examples A and B) were prepared according to Table 3 below.

[0102]

[0103] Similar to Examples 1-3 and Comparative Example AB of the present invention, the above compositions were mixed until a homogeneous mixture was obtained. The homogeneous mixture was then added to the Sharpie assembly. ® In the refill ink chamber of the gel pen, apply a uniform mixture to the porous black sheet and visually assess the opacity of the lines. Figure 2 A visual example of the ink of the present invention and a contrasting ink is shown when writing on black paper.

[0104] like Figure 2 As shown, the embodiments of the present invention (i.e., the compositions prepared according to this disclosure) exhibit bright, opaque lines when applied to a porous black substrate. In contrast, the comparative examples lack opacity and have lower visibility on the substrate. Therefore, it can be seen that, unlike conventional ink formulations, the compositions prepared according to this disclosure provide more opaque markings.

[0105] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. It should also be understood that terms as defined in common dictionaries should be interpreted as having the same meaning as in the context of this specification, and not in an idealized or overly formal sense, unless explicitly defined herein. For the sake of brevity or clarity, well-known functions or constructions may not be described in detail.

[0106] The terms “about” and “approximately” generally refer to the naturalness or precision of a given measurement within the permissible range of error or variation. The numerical quantities given in this specification are approximate values, and unless otherwise stated, this means that the terms “about” or “approximately” can be inferred when not explicitly stated.

[0107] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used herein, the singular forms “a” and “the” are intended to include the plural forms (i.e., at least one referred to by the article they modify) unless the context clearly indicates otherwise.

[0108] The terms “first,” “second,” etc., are used to describe various features or elements, but these features or elements should not be limited by these terms. These terms are used only to distinguish one feature or element from another. Thus, the first feature or element discussed below may be referred to as the second feature or element, and similarly, the second feature or element discussed below may be referred to as the first feature or element, without departing from the teachings of this disclosure. Similarly, the terms “top” and “bottom”; “front” and “rear”; “left” and “right” are used to distinguish certain features or elements from one another, but it is explicitly assumed that top can be bottom, and vice versa.

[0109] The compositions described and claimed herein should not be limited in scope by the specific embodiments disclosed herein, as these embodiments are intended to illustrate various aspects of this disclosure. Any equivalent embodiments are intended to be within the scope of this disclosure. In fact, various modifications other than those shown and described herein will become apparent to those skilled in the art from the foregoing description. Such modifications are also intended to fall within the scope of the appended claims. All patents and patent applications referenced in the foregoing text are expressly incorporated herein by reference. Any section headings herein are provided only for consistency with the recommendations of 37 CFR § 1.77, or otherwise for organizing the collection. These headings should not limit or characterize the invention described herein.

Claims

1. A composition comprising: Hollow particle components; First colorant; Viscosity modifier; Moisturizer; as well as Solvent.

2. The composition according to claim 1, wherein, Based on the total weight of the composition, the first colorant is present in an amount of about 5 to about 15% by weight.

3. The composition according to claim 1, wherein, Based on the total weight of the composition, the hollow particulate component is present in an amount of about 20 to about 40% by weight.

4. The composition according to claim 1, wherein, The moisturizer is present in an amount of about 10 to about 20 percent based on the total weight of the composition.

5. The composition according to claim 1, wherein, The viscosity modifier is present in an amount of about 1 to about 10% by weight, based on the total weight of the composition.

6. The composition according to claim 1, wherein, The composition further includes a dispersant present in an amount of about 2 to about 20% by weight, based on the total weight of the composition.

7. The composition according to claim 1, wherein, The composition further includes a second colorant having a different color from the first colorant.

8. The composition according to claim 1, wherein, The composition is contained in the ink storage chamber of the writing instrument.

9. A durable ink composition comprising: Hollow particle components; First colorant; Viscosity modifier; Moisturizer; Solvent; as well as An optional dispersant, wherein the composition has a first viscosity in a non-shear state and a second viscosity in a shear state, wherein the second viscosity is less than the first viscosity.

10. The durable ink composition according to claim 9, wherein, The colorant is present in an amount of about 5 to about 15% by weight, based on the total weight of the composition.

11. The durable ink composition according to claim 9, wherein, Based on the total weight of the composition, the hollow particulate component is present in an amount of about 20 to about 40% by weight.

12. The durable ink composition according to claim 9, wherein, The moisturizer is present in an amount of about 10 to about 20 percent based on the total weight of the composition.

13. The durable ink composition according to claim 9, wherein, The viscosity modifier is present in an amount of about 1 to about 5% by weight, based on the total weight of the composition.

14. The durable ink composition according to claim 9, wherein, Based on the total weight of the composition, the durable ink composition comprises about 2 to about 20% by weight of a dispersant.

15. The durable ink composition according to claim 9, wherein, The durable ink composition further includes a second colorant having a different color from the first colorant.

16. The durable ink composition of claim 9, wherein the durable ink composition is contained in the ink reservoir of the writing instrument.

17. An ink composition for writing instruments, said ink composition comprising: Hollow particle components; At least one colorant; Viscosity modifier; Moisturizer; as well as Solvent, The ink composition is contained in the ink storage chamber of the writing instrument.

18. The ink composition according to claim 17, wherein, The ink composition further includes a dispersant, which is present in an amount of about 2 to about 20% by weight based on the total weight of the composition.

19. The ink composition according to claim 17, wherein, The viscosity modifier is present in an amount of about 1 to about 5% by weight, based on the total weight of the composition.

20. The ink composition according to claim 17, wherein, The at least one colorant includes a first colorant of a first color and a second colorant of a second color different from the first color.

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