A method for providing an organic solvent-based composition having retroreflective properties.

Abstract

The present invention relates to a method for providing a composition selected from the group consisting of organic solvent-based paste, ink, paint, and coating formulations having retroreflective properties, the method comprising the steps of: a) providing an organic solvent-based paste, ink, paint, or coating formulation without retroreflective properties; b) providing a retroreflective organic solvent-based composition; and c) mixing the organic solvent-based ink, paint, or coating formulation without retroreflective properties provided in step (a) with the retroreflective organic solvent-based composition provided in step (b) in a weight ratio of between 30:70 and 70:30 to provide an organic solvent-based paste, ink, paint, or coating formulation with retroreflective properties.

Description

Technical Field

[0001] Field of the Invention The present invention relates to a method of providing a composition selected from the group consisting of an organic solvent-based paste, ink, paint, and coating formulation having retroreflective properties. The present invention further relates to said method further comprising the step of applying a retroreflective composition to a substrate. Background of the Invention

[0002] The retroreflective effect is used in various applications. For example, to improve the visibility of road signs, road markers, fabrics, automobiles, etc. under dark conditions or simply to improve their visual appearance. Road markers typically have retroreflective properties imparted by adding spherical glass beads having a specific refractive index. Retroreflection occurs by the tandem action of refraction of incident light through the upper surface of the spherical glass beads, internal reflection from the lower inner surface of the spherical glass beads, and subsequent refraction of the light when it exits from the upper surface of the spherical glass beads back in the direction from which the impinging light came.

[0003] WO 2004 / 017104 discloses a retroreflective composition comprising a retroreflective blend of retroreflective microspheres, a binder system, and at least two thixotropic agents in an amount of about 2 to about 5% by weight based on the retroreflective composition. The retroreflective composition is intended to be used as a paint, ink, and coating and is applied to a substrate using an aerosol applicator with an aerosol agent.

[0004] WO 00 / 42113 relates to a retroreflective ink containing microbeads in a liquid carrier medium. The ink is intended for screen printing onto fabrics.

[0005] Organic solvent-based pastes, paints, inks, and coating formulations are commercially available from numerous suppliers, individually formulated in a variety of colors and / or for various applications. Every new application and modification of organic solvent-based pastes, paints, inks, or coating formulations requires a costly and time-consuming development process from laboratory samples to commercial products. Clearly, supplying a wide range of products in various colors and / or for various applications requires large warehouses and substantial inventory to quickly respond to customer orders.

[0006] As described above, adding retroreflective properties to pastes, paints, inks, and coating formulations can be advantageous as it results in improved visibility and / or a more attractive visual appearance.

[0007] The addition of components including retroreflective spherical glass beads should not substantially affect the processability of existing pastes, paints, inks, or coating formulations, let alone the properties of the pastes, paints, inks, or coating formulations after drying or curing. Therefore, developing retroreflective versions of already commercially available organic solvent-based pastes, paints, inks, and coating formulations also requires a costly and time-consuming development process. Supplying retroreflective pastes, paints, inks, and coating formulations in addition to those without retroreflective properties even requires large warehouses.

[0008] Therefore, there is a need for an efficient method to provide organic solvent-based pastes, paints, inks, and coating formulations having retroreflective properties, i.e., commercially available organic solvent-based pastes, paints, inks, and coating formulations, on demand, without substantially altering the processability of the organic solvent-based paints, inks, and coating formulations, and without substantially affecting the properties of the pastes, paints, inks, or coating formulations after drying or curing.

[0009] As shown in the attached examples, the inventors have confirmed that providing organic solvent-based pastes, paints, inks, and coating formulations having retroreflective properties cannot be achieved simply by mixing organic solvent-based pastes, paints, inks, or coating formulations with retroreflective spherical glass beads, because this results in heterogeneity, air inclusion, and / or instability in the distribution of spherical glass beads throughout the composition.

[0010] Therefore, the object of the present invention is to provide an efficient method for providing organic solvent-based pastes, paints, inks, and coating formulations having retroreflective properties without substantially changing the processability of the organic solvent-based paste paints, inks, and coating formulations, and / or without adversely affecting the properties of the pastes, paints, inks, or coating formulations after drying or curing.

[0011] A further object of the present invention is to provide an efficient method for providing organic solvent-based pastes, paints, inks, and coating formulations containing retroreflective spherical glass beads, which result in a homogeneous and stable distribution of retroreflective spherical glass beads throughout the composition.

[0012] [Overview of the prefecture] The inventors have unexpectedly confirmed that one or more objectives can be met by mixing an organic solvent-based paste, paint, ink, or coating formulation without retroreflective properties with an organic solvent-based composition containing retroreflective spherical glass beads and a thickener(s) (the organic solvent-based composition having a first Brookfield viscosity η2 at a shear rate of 0.5 rpm between 5 and 350 Pa·s, and a second Brookfield viscosity η3 at a shear rate of 20 rpm between 100 and 5000 mPa·s, provided that η2 and η3 are measured using a #4 spindle at a temperature of 20°C, and η3 is at least twice as low as η2), and optionally subsequently by adding an additional thickener.

[0013] Therefore, in a first embodiment, the present invention provides a method for providing a composition selected from the group consisting of organic solvent-based pastes, inks, paints and coating formulations having retroreflective properties, a) From 1 mPa·s measured using a #1 spindle in a 600 ml beaker with a diameter of 8.25 cm The step of preparing an organic solvent-based paste, ink, paint, or coating formulation that has no retroreflective properties, having a shear rate of 0.5 rpm and a Brookfield viscosity η1 at a temperature of 20°C, measured using a #5 spindle at a shear rate of 300 Pa·s in a 600 ml beaker having a diameter of 8.25 cm; b) A step of preparing a retroreflective organic solvent system composition having η2 at a shear rate of 0.5 rpm between 5 to 350 Pa·s and η3 at a shear rate of 20 rpm between 100 to 5000 mPa·s, provided that the first Brookfield viscosity η2 and the second Brookfield viscosity η3 are measured in a 600 ml beaker having a diameter of 8.25 cm at a temperature of 20°C using a #4 spindle, and η3 is at least twice as low as η2, wherein The retroreflective organic solvent system composition is based on the total weight of the retroreflective organic solvent system composition. 10-49.85% by weight of organic solvent; Spherical glass beads weighing 50-85% by weight, having a median particle size D50 between 1 and 1500 μm as measured by laser diffraction, and a refractive index between 1.5 and 2.8 as measured at a wavelength λ of 589 nm; 0.15 to 3.5% by weight of a thickening agent; and A step consisting of 0-10% by weight of one or more additional components; c) A step to prepare an organic solvent-based paste, ink, paint, or coating formulation having retroreflective properties by mixing the organic solvent-based ink, paint, or coating formulation without retroreflective properties prepared in step (a) with the retroreflective organic solvent-based composition prepared in step (b) in a weight ratio between 30:70 and 70:30; d) optionally mixing the organic solvent-based paste, ink, paint, or coating formulation having retroreflective properties obtained in step (c) with 0 to 4.5% by weight of synthetic pigment flakes having an average diameter between 5 and 150 μm, a thickness of less than 1 μm, and an aspect ratio of at least 10, based on the total weight of the organic solvent-based paste, ink, paint, or coating formulation having retroreflective properties obtained in step (c); and e) The method optionally includes the step of mixing the mixture obtained in step (c) or (d) with 0 to 3% by weight of a thickener, based on the total weight of the organic solvent-based paste, ink, paint, or coating formulation having retroreflective properties obtained in step (c) or (d), respectively.

[0014] The retroreflective organic solvent-based composition prepared in step (b) consists mainly of an organic solvent and spherical glass beads. The inert spherical glass beads have little to no effect on the organic solvent-based paste, ink, paint, or coating formulation. Therefore, these systems are highly compatible with "commercial" organic solvent-based paste, ink, paint, or coating formulations. The organic solvent disappears from the paste, ink, paint, or coating formulation as it dries or hardens. The inventors have confirmed that the processability of the organic solvent-based paste, paint, ink, and coating formulation prepared in step (a) is hardly altered when the retroreflective organic solvent-based composition defined in step (b) is added in appropriate amounts along with the optional addition of a thickener. Since the retroreflective spherical glass beads are added in the form of a sufficiently stable and homogeneous organic solvent composition as defined in step (b), they can be added without air incorporation to the organic solvent paste, ink, paint or coating formulation without retroreflective properties as defined in step (a), resulting in a sufficiently stable and homogeneous organic solvent paste, ink, paint or coating formulation with retroreflective properties.

[0015] definition In the context of the retroreflective organic solvent-based composition prepared in step (b) of the process as defined herein, the term “shear viscosity reduction behavior” relates to the decrease in viscosity when a composition that is initially in a static state is subjected to a certain shear rate.

[0016] Detailed explanation In a first embodiment, the present invention provides a method for providing a composition selected from the group consisting of organic solvent-based pastes, inks, paints, and coating formulations having retroreflective properties, a) From 1 mPa·s measured using a #1 spindle in a 600 ml beaker with a diameter of 8.25 cm The step of preparing an organic solvent-based paste, ink, paint, or coating formulation that has no retroreflective properties, having a shear rate of 0.5 rpm and a Brookfield viscosity η1 at a temperature of 20°C, measured using a #5 spindle at a shear rate of 300 Pa·s in a 600 ml beaker having a diameter of 8.25 cm; b) A step of preparing a retroreflective organic solvent system composition having η2 at a shear rate of 0.5 rpm between 5 to 350 Pa·s and η3 at a shear rate of 20 rpm between 100 to 5000 mPa·s, provided that the first Brookfield viscosity η2 and the second Brookfield viscosity η3 are measured in a 600 ml beaker having a diameter of 8.25 cm at a temperature of 20°C using a #4 spindle, and η3 is at least twice as low as η2, wherein The retroreflective organic solvent system composition is based on the total weight of the retroreflective organic solvent system composition. 10-49.85% by weight of organic solvent; Spherical glass beads weighing 50-85% by weight, having a median particle size D50 between 1 and 1500 μm as measured by laser diffraction, and a refractive index between 1.5 and 2.8 as measured at a wavelength λ of 589 nm; 0.15 to 3.5% by weight of a thickening agent; and A step consisting of 0-10% by weight of one or more additional components; c) Step of preparing an organic solvent-based ink, paint or coating formulation without retroreflective properties prepared in step (a) and mixing it with the retroreflective organic solvent-based composition prepared in step (b) at a weight ratio between 30:70 and 70:30 to prepare an organic solvent-based paste, ink, paint or coating formulation having retroreflective properties; d) Optionally, step of mixing the organic solvent-based paste, ink, paint or coating formulation having retroreflective properties obtained in step (c), optionally, with synthetic pigment flakes having an average diameter between 5 and 150 μm, a thickness less than 1 μm and an aspect ratio of at least 10, based on the total weight of the organic solvent-based paste, ink, paint or coating formulation having retroreflective properties obtained in step (c); and e) Optionally, step of mixing the mixture obtained in step (c) or (d) with a thickener of 0 to 3% by weight, based on the total weight of the organic solvent-based paste, ink, paint or coating formulation having retroreflective properties obtained in step (c) or (d) respectively. The present invention relates to a method comprising this step.

[0017] In a highly preferred embodiment, the first aspect is a method of providing a composition selected from the group consisting of an organic solvent-based paste, ink, paint and coating formulation having retroreflective properties, comprising a) Having a Brookfield viscosity η1 at a shear rate of 0.5 rpm and a temperature of 20 °C between 1 mPa·s measured using spindle #1 in a 600 ml beaker having a diameter of 8.25 cm and 300 Pa·s measured using spindle #5 in a 600 ml beaker having a diameter of 8.25 cm, step of preparing an organic solvent-based paste, ink, paint or coating formulation without retroreflective properties; b) A step of preparing a retroreflective organic solvent-based composition having a Brookfield viscosity η2 at a shear rate of 0.5 rpm between 5 and 350 Pa·s and a Brookfield viscosity η3 at a shear rate of 20 rpm between 100 and 5000 mPa·s, wherein the first Brookfield viscosity η2 and the second Brookfield viscosity η3 are measured at a temperature of 20 °C in a 600 ml beaker having a diameter of 8.25 cm using a #4 spindle, provided that η3 is at least 2 times lower than η2. wherein the retroreflective organic solvent-based composition is based on the total weight of the retroreflective organic solvent-based composition 15 to 49.85 wt% organic solvent; 50 to 80 wt% spherical glass beads having a median particle size D50 between 1 and 1500 μm measured using laser diffraction and a refractive index between 1.5 and 2.8 measured at a wavelength λ of 589 nm; 0.15 to 3.5 wt% thickener; and consisting of 0 to 10 wt% of one or more additional components; c) A step of mixing the non-retroreflective organic solvent-based ink, paint or coating formulation prepared in step (a) with the retroreflective organic solvent-based composition prepared in step (b) at a weight ratio between 30:70 and 70:30 to prepare a retroreflective organic solvent-based paste, ink, paint or coating formulation. d) Optionally, mixing the retroreflective organic solvent-based paste, ink, paint or coating formulation obtained in step (c) with 0 to 4.5 wt% synthetic pigment flakes having an average diameter between 5 and 150 μm, a thickness less than 1 μm and an aspect ratio of at least 10, based on the total weight of the retroreflective organic solvent-based paste, ink, paint or coating formulation obtained in step (c); and e) Optionally, mixing the mixture obtained in step (c) or (d) with 0 to 3 wt% thickener, based on the total weight of the retroreflective organic solvent-based paste, ink, paint or coating formulation obtained in step (c) or (d) respectively. The method relates to a method comprising this step.

[0018] As will be recognized by those skilled in the art, limited sedimentation, (phase) separation, and / or synecession of retroreflective organic solvent-based compositions prepared in step (b) of the process as defined herein is not a problem if the compositions can be resuspended to obtain compositions that remain homogeneous for a sufficiently long time to be processed, for example using simple stirring (i.e., by mixing them with organic solvent-based pastes, inks, paints, or coating formulations without retroreflective properties, prepared in step (a) of the process as defined herein). Similarly, limited sedimentation, (phase) separation, and / or synecession of retroreflective organic solvent-based pastes, inks, paints, or coating formulations prepared in step (c), (d), or (e) of the process as defined herein is not a problem if the compositions can be resuspended to obtain compositions that remain stable and homogeneous for a sufficiently long time to be processed, for example using simple stirring (i.e., by coating them onto a target substrate). As shown in the attached examples, both the retroreflective organic solvent-based composition prepared in step (b) of the process as defined herein, and the retroreflective organic solvent-based paste, ink, paint or coating formulation prepared in step (c), (d), or (e) of the process as defined herein, remain stable and homogeneous for a sufficiently long time to be processed.

[0019] In step (c), the organic solvent-based paste, ink, paint, or coating formulation prepared in step (a) is mixed with the retroreflective organic solvent-based composition prepared in step (b) in a weight ratio between 60:40 and 40:60, more preferably between 45:55 and 55:45.

[0020] In a preferred embodiment, the method as defined herein further includes the step of applying an organic solvent-based paste, ink, paint or coating formulation having retroreflective properties obtained in step (c), (d), or (e) to a substrate using screen printing, curtain coating, spray coating or spray painting.

[0021] In a preferred embodiment, steps (c), (d), and (e) are carried out at a temperature between 15 and 30°C with stirring. To avoid the incorporation of air bubbles, stirring is preferably carried out at a low shear rate. In another preferred embodiment, step (c) includes adding the retroreflective organic solvent composition prepared in step (b) to the non-retroreflective organic solvent paste, ink, paint, or coating formulation prepared in step (a).

[0022] The synthetic pigment flakes added in the optional step (d) are preferably selected from the synthetic pigment flakes defined herein under “Further Components”.

[0023] Organic solvents As used herein, the term "organic solvent" refers to an organic solvent, or a mixture of organic solvents containing less than 3% by weight of water, preferably less than 2% by weight of water, more preferably less than 1% by weight of water, and even more preferably less than 0.5% by weight of water (most preferably anhydrous).

[0024] Preferred organic solvents include aliphatic and aromatic solvents, ketones, esters, and glycosides. ruThe organic solvent is selected from the group consisting of ethers, alcohols, halogenated hydrocarbons, and combinations thereof. A very preferred organic solvent is selected from the group consisting of xylene (a mixture of isomers), toluene, ethylbenzene, naphtha, 1,2,4-trimethylbenzene, mesitylene, n-propylbenzene, isopentyl acetate, n-butyl acetate, (2-methoxymethylethoxy)propanol, 2-butoxyethyl acetate, 2-methylbutyl acetate, isobutanol, 1-butanol, 1-ethoxypropan-2-ol, 2,6-dimethyl-4-heptanone, 2-methoxy-1-methylethyl acetate, 4,6-dimethylheptan-2-one, 4-methyl-2-pentanone, 1-methoxy-2-propanol, 1-methoxy-2-propyl acetate, 2-(2-butoxyethoxy)ethanol, 2-butoxyethanol, 5-methylhexane-2-one, ethyl acetate, and combinations thereof.

[0025] In a very preferred embodiment, the amount of organic solvent is 15 to 49.85% by weight based on the total weight of the retroreflective organic solvent composition prepared in step (b).

[0026] In a preferred embodiment, the amount of organic solvent is 20 to 45% by weight, more preferably 25 to 40% by weight, and even more preferably 28 to 35% by weight, based on the total weight of the retroreflective organic solvent composition prepared in step (b).

[0027] In embodiments, the amount of organic solvent is 15-48% by weight, 15-45% by weight, 15-42% by weight, 15-40% by weight, or 15-38% by weight, based on the total weight of the retroreflective organic solvent composition prepared in step (b).

[0028] In embodiments, the amount of organic solvent is 10-48% by weight, 10-45% by weight, 10-42% by weight, 10-40% by weight, or 10-38% by weight, based on the total weight of the retroreflective organic solvent composition prepared in step (b).

[0029] In other embodiments, the amount of organic solvent is 20-49.85% by weight, 24-49.85% by weight, 26-49.85% by weight, 28-49.85% by weight, 29-49.85% by weight, or 30-49.85% by weight, based on the total weight of the retroreflective organic solvent composition prepared in step (b).

[0030] Spherical glass beads As defined above, the refractive index of spherical glass beads measured at a wavelength λ of 589 nm is between 1.5 and 2.8.

[0031] In a preferred embodiment, the spherical glass beads are (a) Between 2.0 and 2.8, preferably between 2.1 and 2.4; or (b) Having a refractive index measured at a wavelength λ of 589 nm, between 1.7 and 2.1, preferably between 1.8 and 2.0.

[0032] In preferred embodiments, the term "glass" in "spherical glass beads" as used herein refers to amorphous, shapeless solids and transparent materials made of oxides. In other embodiments, the term "glass" in "spherical glass beads" refers to solids and transparent materials made of oxides that contain some degree of microcrystallineity. The refractive index of spherical glass beads is closely related to the density of the glass, but the relationship is not linear. Due to the properties of glass, the density is approximately an additive function of its composition. The density of spherical glass beads with a refractive index between 1.5 and 2.8 is typically between 2.5 and 4.5 g / cm³. 3 It fluctuates between these two ranges.

[0033] The oxides that can be used in glass are those of silicon, boron, aluminum, sodium, barium, vanadium, titanium, lanthanum, strontium, zirconium, potassium, magnesium, iron, calcium, zinc, lithium, barium, and lead. Spherical glass beads can include various combinations of, for example, silica (SiO2), boron oxide (B2O3), phosphorus pentoxide (P2O5), vanadium pentoxide (V2O5), arsenic trioxide (As2O3), germanium oxide (GeO2), calcium oxide (CaO), sodium oxide (Na2O), magnesium oxide (MgO), zinc oxide (ZnO), aluminum oxide (Al2O3), potassium oxide (K2O), iron oxide (Fe2O3), lead oxide (PbO), barium oxide (BaO), barium titanate (BaTiO3), titanium oxide (TiO2), lithium oxide (Li2O), strontium oxide (SrO), lanthanum oxide (La2O3), and zirconium oxide (ZrO2). Silica and boron oxide generally have the lowest densities. Glass containing a large weight percentage of these oxides therefore generally results in glass beads with a low refractive index. The refractive index can be increased by adding an oxide having a high molecular weight. Preferably, the spherical glass beads do not contain PbO.

[0034] Glass beads having refractive indices in the range of 1.5 to 2.51 and their compositions in terms of oxides are disclosed in International Publication No. 2014 / 109564, which is incorporated herein by reference in its entirety. Transparent glass beads without PbO having a refractive index greater than 2.15 are disclosed in U.S. Patent No. 4,082,427, which is incorporated herein by reference in its entirety.

[0035] Spherical glass beads may be colored spherical glass beads, as long as transparency is maintained. Both colored spherical glass beads made from colored transparent glass and spherical glass beads with a concentric transparent colored coating are included in the present invention. The color may be a natural color resulting from the oxide composition, or it may be intentionally selected by adding a component having a specific color. Colored glass beads with high refractive index and high transparency are disclosed in International Publication No. 2014 / 109564.

[0036] Therefore, in the embodiment, at least a portion of the spherical glass beads are spherical glass beads made of colored transparent glass, and / or at least a portion of the spherical glass beads are coated with a concentric transparent colored coating.

[0037] Spherical glass beads have a median diameter D50, which is measured by laser diffraction. Therefore, the median diameter D50 is the volume median based on the volume distribution. The median diameter D50 is the diameter that half of the spherical glass beads in the collection fall below. This volume median diameter is often referred to in the art as Dv50 or D v0.5 It is called [name].

[0038] In a very preferred embodiment, the spherical glass beads have a median particle size D50, measured using laser diffraction, between 5 and 1500 μm.

[0039] In the embodiment, the spherical glass beads have a median particle size D50, measured using laser diffraction, between 25 and 100 μm, preferably between 30 and 75 μm, and more preferably between 35 and 50 μm.

[0040] In a preferred embodiment, the spherical glass beads have a median particle size D50, measured by laser diffraction, between 5 and 100 μm, for example between 5 and 75 μm, between 5 and 50 μm, between 5 and 45 μm, between 5 and 40 μm, or between 5 and 35 μm.

[0041] In a preferred embodiment, the spherical glass beads have a median particle size D50, measured by laser diffraction, between 1 and 100 μm, for example, between 1 and 75 μm, between 1 and 50 μm, between 1 and 45 μm, between 1 and 40 μm, between 1 and 35 μm, between 1 and 30 μm, between 1 and 25 μm, between 1 and 20 μm, between 1 and 15 μm, or between 1 and 10 μm.

[0042] In another embodiment, the spherical glass beads have a median particle size D50, measured using laser diffraction, between 25 and 150 μm, for example, between 50 and 150 μm, between 75 and 150 μm, between 100 and 150 μm, between 110 and 150 μm, or between 115 and 150 μm.

[0043] In another embodiment, the spherical glass beads have a median particle size D50, measured by laser diffraction, between 5 and 1400 μm, for example, between 5 and 1200 μm, between 5 and 1000 μm, between 5 and 800 μm, between 5 and 500 μm, or between 5 and 300 μm.

[0044] In another embodiment, the spherical glass beads have a median particle size D50, measured by laser diffraction, between 1 and 1400 μm, for example, between 1 and 1200 μm, between 1 and 1000 μm, between 1 and 800 μm, between 1 and 500 μm, or between 1 and 300 μm.

[0045] Diameters D10 and D90 are often referred to as Dv10 or D in the art, respectively. v0.1 and Dv90 or D v0.9 These are called D10 diameters. A D10 diameter is the diameter that 10% of a group of spherical glass beads fall below. Similarly, a D90 diameter is the diameter that 90% of a group of spherical glass beads fall below.

[0046] The span of the particle size distribution of spherical glass beads measured by laser diffraction is defined as follows:

[0047]

number

[0048] In another embodiment, the spherical glass beads have a median particle size D50 measured by laser diffraction between 15 and 100 μm, and a span between 0 and 1.9, for example between 0 and 1.5, between 0 and 1, between 0 and 0.5, between 0 and 0.2, or between 0 and 0.1.

[0049] In another embodiment, the spherical glass beads have a median particle size D50 measured using laser diffraction, between 30 and 75 μm, and a span between 0 and 1.9, for example, between 0 and 1.5, between 0 and 1, between 0 and 0.5, between 0 and 0.2, or between 0 and 0.1.

[0050] In another preferred embodiment, the spherical glass beads have a median particle size D50, measured by laser diffraction, between 15 and 50 μm, and a span between 0 and 1.9, for example, between 0 and 1.5, between 0 and 1, between 0 and 0.5, between 0 and 0.2, or between 0 and 0.1.

[0051] In another preferred embodiment, the spherical glass beads have a median particle size D50 measured by laser diffraction between 5 and 35 μm, and a span between 0 and 1.9, for example between 0 and 1.5, between 0 and 1, between 0 and 0.5, between 0 and 0.2, or between 0 and 0.1.

[0052] In another preferred embodiment, the spherical glass beads have a median particle size D50 measured by laser diffraction between 1 and 35 μm, and a span between 0 and 1.9, for example, between 0 and 1.5, between 0 and 1, between 0 and 0.5, between 0 and 0.2, or between 0 and 0.1.

[0053] In another preferred embodiment, the spherical glass beads have a median particle size D50 measured by laser diffraction between 10 and 25 μm, and a span between 0 and 1.9, for example between 0 and 1.5, between 0 and 1, between 0 and 0.5, between 0 and 0.2, or between 0 and 0.1.

[0054] In another preferred embodiment, the spherical glass beads have a median particle size D50 measured by laser diffraction between 1 and 25 μm and a span between 0 and 1.9, for example, between 0 and 1.5, between 0 and 1, between 0 and 0.5, between 0 and 0.2, or between 0 and 0.1.

[0055] In another preferred embodiment, the spherical glass beads have a median particle size D50 measured by laser diffraction between 1 and 15 μm, and a span between 0 and 1.9, for example between 0 and 1.5, between 0 and 1, between 0 and 0.5, between 0 and 0.2, or between 0 and 0.1.

[0056] In another preferred embodiment, the spherical glass beads have a median particle size D50 measured by laser diffraction between 1 and 10 μm, and a span between 0 and 1.9, for example between 0 and 1.5, between 0 and 1, between 0 and 0.5, between 0 and 0.2, or between 0 and 0.1.

[0057] As will be understood by those skilled in the art, span=0 corresponds to monodisperse spherical glass beads.

[0058] In a preferred embodiment, at least a portion of the spherical glass beads are hemispherical coated with a light-reflective coating, preferably a hemispherical aluminum coating (HAC). In another embodiment, at least a portion of the spherical glass beads are fluorinated.

[0059] The specific applications of the retroreflective organic solvent-based ink, coating, or paint composition prepared in step (c), (d), or (e) determine the optimal refractive index of the spherical glass beads used in the retroreflective organic solvent-based composition prepared in step (b). When the composition is applied in a dry environment or on a substrate that will exhibit retroreflective properties under dry conditions, and the coating layer of retroreflective spherical glass beads is not coated by any further layer, the refractive index of the spherical glass beads, measured at a wavelength λ of 589 nm, may be between 1.8 and 2.8.

[0060] In the embodiment, the retroreflective organic solvent-based composition prepared in step (b) and the retroreflective organic solvent-based ink, coating, or paint composition prepared in step (c), (d), or (e) include spherical glass beads having a refractive index between 1.8 and 2.0 as measured at a wavelength λ of 589 nm.

[0061] On the other hand, if the composition is to be applied to a substrate that will exhibit retroreflectivity in a humid environment or under humid conditions, or if the coating layer of retroreflective spherical glass beads is coated with one or more further transparent layers, the refractive index of the spherical glass beads, measured at a wavelength λ of 589 nm, is preferably between 2.0 and 2.8, more preferably between 2.2 and 2.4. Compositions that will exhibit retroreflectivity under both dry and humid conditions, and if the coating layer of retroreflective spherical glass beads is coated with one or more further transparent layers or not, may include different types of glass beads having different refractive indices and optionally different sizes. In embodiments, the retroreflective organic solvent-based composition prepared in step (b) and the retroreflective organic solvent-based ink, coating or paint composition prepared in step (c), (d), or (e) include spherical glass beads having a refractive index measured at a wavelength λ of 589 nm, between 2.0 and 2.8, preferably between 2.2 and 2.4.

[0062] In another embodiment, the retroreflective organic solvent-based composition prepared in step (b) and the retroreflective organic solvent-based ink, coating or paint composition prepared in step (c), (d), or (e) include at least two types of spherical glass beads, where at least one type of spherical glass bead has a refractive index measured at a wavelength λ of 589 nm between 1.8 and less than 2.0, and at least one further type of spherical glass bead has a refractive index measured at a wavelength λ of 589 nm between 2.0 and 2.8.

[0063] In a very preferred embodiment, the amount of spherical glass beads is 50 to 80% by weight based on the total weight of the retroreflective organic solvent composition prepared in step (b).

[0064] In a preferred embodiment, the amount of spherical glass beads is 53 to 75% by weight, more preferably 58 to 72% by weight, and even more preferably 60 to 70% by weight, based on the total weight of the retroreflective organic solvent composition prepared in step (b).

[0065] In embodiments, the amount of spherical glass beads is 50-78% by weight, 50-75% by weight, 50-73% by weight, 50-72% by weight, 50-71% by weight, 50-70% by weight, or 50-69% by weight, based on the total weight of the retroreflective organic solvent composition prepared in step (b).

[0066] In other embodiments, the amount of spherical glass beads is 52-80% by weight, 54-80% by weight, 56-80% by weight, 57-80% by weight, 58-80% by weight, 59-80% by weight, or 60-80% by weight, based on the total weight of the retroreflective organic solvent composition prepared in step (b).

[0067] In other embodiments, the amount of spherical glass beads is 52-85% by weight, 54-85% by weight, 56-85% by weight, 57-85% by weight, 58-85% by weight, 59-85% by weight, or 60-85% by weight, based on the total weight of the retroreflective organic solvent composition prepared in step (b).

[0068] Thickening agent The retroreflective organic solvent system composition prepared in step (b) of the method as defined herein comprises a thickener. This may be (optionally) the same thickener applied in step (e). The term "thickener" as used herein may also mean one or a combination of thickeners. Thus, "thickener" and "thickener(s)" are used interchangeably unless otherwise indicated.

[0069] In one embodiment, a single thickener is used in the retroreflective organic solvent composition prepared in step (b). In another embodiment, a single thickener is used in step (e).

[0070] In a preferred embodiment, the thickener includes a mixture of various thickeners. In an embodiment, a mixture of various thickeners is used in the retroreflective organic solvent composition prepared in step (b). In another embodiment, a mixture of various thickeners is used in step (e).

[0071] In one embodiment, the thickener applied in step (e) is the same thickener applied to the retroreflective organic solvent composition prepared in step (b). In another embodiment, the thickener applied in step (e) is different from the thickener applied to the retroreflective organic solvent composition prepared in step (b).

[0072] As will be recognized by those skilled in the art, the non-reflective organic solvent-based paste, ink, paint or coating formulation prepared in step (a) may also contain a thickener. If present, this thickener may be the same as or different from the thickener applied in step (b) and / or step (e).

[0073] While we do not wish to be bound by any theory, it is believed that the thickener limits or reduces the precipitation and / or settling of spherical glass beads and optionally further particulate matter in the retroreflective organic solvent-based composition prepared in step (b) and the final organic solvent-based paste, ink, paint, or coating formulation having retroreflective properties prepared in steps (c), (d), or (e), as a result, these compositions can be easily resuspended. Furthermore, again, while we do not wish to be bound by any theory, it is believed that the thickener provides a retroreflective organic solvent-based composition having shear-thinning behavior, prepared in step (b).

[0074] In a preferred embodiment, the amount of thickener in the retroreflective organic solvent composition prepared in step (b) is 0.20 to 3.0% by weight, more preferably 0.25 to 2.5% by weight, and even more preferably 0.30 to 2.1% by weight, based on the total weight of the retroreflective organic solvent composition prepared in step (b).

[0075] In embodiments, the amount of the thickener in the retroreflective organic solvent composition prepared in step (b) is 0.15 to 2.5% by weight, 0.15 to 2.0% by weight, 0.15 to 1.75% by weight, 0.15 to 1.5% by weight, or 0.15 to 1.3% by weight, based on the total weight of the retroreflective organic solvent composition prepared in step (b).

[0076] In other embodiments, the amount of thickener in the retroreflective organic solvent composition prepared in step (b) is 0.20 to 3.50% by weight, 0.30 to 3.50% by weight, 0.40 to 3.50% by weight, 0.50 to 3.50% by weight, 0.60 to 3.50% by weight, 0.70 to 3.50% by weight, or 0.80 to 3.50% by weight, based on the total weight of the retroreflective organic solvent composition prepared in step (b).

[0077] In a preferred embodiment, the mixture obtained in step (c) or (d) is mixed in step (e) with a thickener in an amount of 0-2.5% by weight, 0-2.0% by weight, 0-1.8% by weight, 0-1.6% by weight, 0-1.5% by weight, 0-1.4% by weight, or 0-1.3% by weight, based on the total weight of the retroreflective organic solvent-based paste, ink, paint, or coating formulation obtained in step (c) or (d), respectively.

[0078] In another preferred embodiment, the mixture obtained in step (c) or (d) is mixed in step (e) with a thickener in an amount of 0.1–3.0% by weight, 0.2–3.0% by weight, 0.3–3.0% by weight, 0.4–3.0% by weight, or 0.5–3.0% by weight, based on the total weight of the retroreflective organic solvent-based paste, ink, paint, or coating formulation obtained in step (c) or (d), respectively.

[0079] Preferred examples of thickeners that can be used in the retroreflective organic solvent-based composition prepared in step (b) and / or step (e) are selected from the group consisting of (modified) hydrogenated castor oil, clay, modified clay, calcium sulfonate complex, organic affinity phyllosilicate, silica gel, synthetic amorphous silica, acrylic acid-type gelling agents, modified cellulose-based materials, polyurea dispersions, solutions of urea-modified polyamides, polyurethane dispersions, and combinations thereof.

[0080] Examples of modified clays include BENTONE® LT and BENTONE® 38 (Elementis Global). Examples of silica gel include HDK® N20 (Wacker Chemical Corporation) and AEROSIL® (Evonik). An example of an organic affinity phyllosilicate is Claytone 40 (Byk). An example of a modified hydrogenated castor oil is Efka® RM 1900 (BASF). An example of hydrogenated castor oil is Efka® RM 1920 (BASF). An example of a solution of urea-modified nonpolar polyamide in isobutanol / monophenyl glycol is Rheobyk-431 (Byk). An example of a solution of medium-polarity urea-modified polyamide in isobutanol / solvent naphtha is Rheobyk-430 (Byk). An example of synthetic amorphous silica is Zeothix (registered trademark) 95 (Huber).

[0081] In a preferred embodiment, the retroreflective organic solvent composition prepared in step (b) and / or step (e) contains two thickeners, more preferably: Organic affinity phyllosilicates and modified hydrogenated castor oil; or A calcium sulfonate complex and a polyurea dispersion are used.

[0082] The amount of organic solvent in the retroreflective organic solvent system composition prepared in step (b) is independently specified. If the thickener is applied, for example, in the form of a dispersion in a solvent, the amount of the thickener as defined in the context of step (b) is related to the dry weight of the thickener. If the thickener is applied, for example, in the form of a dispersion in a solvent in step (e), the amount of the thickener as defined in the context of step (e) is related to the dry weight.

[0083] Further ingredients As described above, the retroreflective organic solvent system composition prepared in step (b) comprises 0 to 10% by weight of one or more additional components. As will be recognized by those skilled in the art, the “additional” components are different from the other components defined in the retroreflective organic solvent system composition prepared in step (b). In other words, the additional components do not include spherical glass beads, thickeners, and organic solvents.

[0084] In embodiments, one or more further components are selected from the group consisting of foam control agents, preservatives, dyes, curing initiators, luminescent agents such as phosphorescent and fluorescent agents, pigments, UV absorbers, binders, and resins.

[0085] Suitable binders and resins for compositions based on organic solvents are generally known to those skilled in the art. The binder or resin may be radiation-curable. If the binder or resin is radiation-curable, further components may include curing initiators such as photoinitiators or thermal initiators.

[0086] In embodiments, one or more further components do not include any dye, pigment, binder, resin, or curing initiator.

[0087] In a preferred embodiment, one or more further components do not include any binder, resin, or curing initiator.

[0088] In embodiments, the retroreflective organic solvent composition prepared in step (b) includes, as part of one or more further components, a synthetic pigment flake having an average diameter between 5 and 150 μm, a thickness of less than 1 μm, and an aspect ratio (flake diameter / thickness) of at least 10, wherein the synthetic pigment flake is selected from (A), (B), (C), or a combination thereof: (A) Metal flakes or synthetic mica flakes coated with at least one layer of one or more components selected from the group consisting of metal oxides, metals, metal sulfides, titanium oxide, titanium oxynitride, FeO(OH), SiO2, B2O3, GeO2, MgF2, alloys, and rare earth compounds, and coated with an outer layer containing one or more colorants and binders, optionally; (B) Thin sheets containing Al2O3, SiO2, glass, ceramic, graphite, or mica plates, coated with at least one layer of one or more components selected from the group consisting of metal oxides, metals, metal sulfides, titanium oxide, titanium oxynitride, FeO(OH), SiO2, B2O3, GeO2, alloys, and rare earth compounds, and optionally coated with an outer layer containing one or more colorants and binders; (C) A thin sheet containing an Al2O3 plate doped with one or more components selected from the group consisting of TiO2, ZrO2, SiO2, SnO2, In2O3, ZnO, and iron oxide, which is coated with at least one layer of one or more components selected from the group consisting of metal oxides, metals, metal sulfides, titanium oxide, titanium oxynitride, FeO(OH), SiO2, B2O3, GeO2, alloys, and rare earth compounds, and optionally coated with an outer layer containing one or more colorants and binders.

[0089] In the context of synthetic pigment flakes, the term "average diameter" refers to the median particle size D50.

[0090] As will be recognized by those skilled in the art, the term "synthetic" in "synthetic pigment flakes" means that the pigment flakes are not naturally occurring pigment flakes, but rather chemically manufactured pigment flakes, or chemically / physically processed naturally occurring pigment flakes. One advantage of using synthetic pigment flakes is that they have a very smooth surface, which can result in increased reflectivity.

[0091] As used herein, the terms “flake” or “plate” refer to a shape of pigment having a large surface area and a thin thickness. Typically, flakes or plates are characterized by their “aspect ratio,” which is defined as the largest dimension (i.e., the largest diameter of the surface divided by the smallest dimension (i.e., thickness)). The synthetic pigment flakes used herein have an aspect ratio of at least 10, preferably at least 15, and more preferably at least 20.

[0092] In a preferred embodiment, the average diameter of the synthetic flakes is 6 to 45 μm, more preferably 7 to 35 μm, even more preferably 8 to 25 μm, still more preferably 9 to 20 μm, and most preferably 10 to 16 μm.

[0093] In a preferred embodiment, the thickness of the synthetic flake is between 10 nm and 800 nm, more preferably between 15 nm and 600 nm. In another preferred embodiment, the thickness of the synthetic flake is between 10 and 200 nm, more preferably between 10 and 150 nm, even more preferably between 10 and 100 nm, and still more preferably between 10 and 50 nm.

[0094] In embodiments, the amount of one or more further components in the retroreflective organic solvent composition prepared in step (b) is 0-8.0% by weight, 0-6.0% by weight, 0-4.0% by weight, 0-3.0% by weight, 0-2.5% by weight, 0-2.0% by weight, 0-1.5% by weight, 0-1.0% by weight, or 0-0.5% by weight, based on the total weight of the retroreflective organic solvent composition prepared in step (b).

[0095] In other embodiments, the amount of one or more further components in the retroreflective organic solvent system composition prepared in step (b) is 0.01 to 10% by weight, 0.02 to 10% by weight, 0.04 to 10% by weight, 0.08 to 10% by weight, 0.15 to 10% by weight, 0.25 to 10% by weight, 0.35 to 10% by weight, 0.45 to 10% by weight, or 0.55 to 10% by weight, based on the total weight of the retroreflective organic solvent system composition prepared in step (b).

[0096] The amount of organic solvent in the retroreflective organic solvent system composition prepared in step (b) is specified independently. If one or more further components are applied, for example, in the form of a solution, suspension, or dispersion in a solvent, the amount of one or more further components as defined above relates to the dry weight of one or more further components, i.e., the weight excluding the solvent.

[0097] Rheological behavior The viscosity measured and defined herein is the so-called Brookfield viscosity. As is known to those skilled in the art, the Brookfield viscosity of different compositions may need to be measured using different standardized spindles. Very low viscosity compositions are usually determined using spindle #1, but high viscosity compositions are usually determined using spindle #5. Medium viscosity compositions may be determined using spindles #2, #3, or #4.

[0098] The viscosity of the non-reflective organic solvent-based paste, ink, paint, or coating formulation prepared in step (a) of the method defined herein may vary from very low to very high values. Therefore, the lower limit of the Brookfield viscosity range is determined using spindle #1, and the upper limit is determined using spindle #5.

[0099] In a preferred embodiment, an organic solvent-based paste, ink, paint, or coating formulation without retroreflective properties is: From 5 mPa·s, more preferably 10 mPa·s, measured using a #1 spindle in a 600 ml beaker with a diameter of 8.25 cm It has a Brookfield viscosity η1 at a shear rate of 0.5 rpm and a temperature of 20°C, measured using a #5 spindle in a 600 ml beaker having a diameter of 8.25 cm, with a shear rate between 280 Pa·s, more preferably 250 Pa·s.

[0100] The retroreflective organic solvent system composition prepared in step (b) of the method defined herein exhibits shear viscosity reduction behavior.

[0101] In a preferred embodiment, the retroreflective organic solvent composition prepared in step (b) has a first Brookfield viscosity η2 and a second Brookfield viscosity η3, which are measured at a temperature of 20°C using a #4 spindle in a 600 ml beaker having a diameter of 8.25 cm, with η3 being at least four times lower than η2, wherein η2 is between 8 and 325 Pa·s and η3 is between 110 and 4000 mPa·s and η3 is between 110 and 4000 mPa·s and η3 is between 20 rpm.

[0102] In another preferred embodiment, the retroreflective organic solvent system composition prepared in step (b) has a first Brookfield viscosity η2 and a second Brookfield viscosity η3, which are measured at a temperature of 20°C using a #4 spindle in a 600 ml beaker having a diameter of 8.25 cm, with η2 being at a shear rate of 0.5 rpm between 10 and 310 Pa·s and η3 being at a shear rate of 20 rpm between 125 and 4000 mPa·s, provided that η3 is at least 5 times lower than η2.

[0103] In another embodiment, the retroreflective organic solvent system composition prepared in step (b) has a first Brookfield viscosity η2 and a second Brookfield viscosity η3, which are measured at a temperature of 20°C using a #4 spindle in a 600 ml beaker having a diameter of 8.25 cm, provided that η3 is at least 30, 50, 60, 70, or 80 times lower than η2, with η2 at a shear rate of 0.5 rpm between 5 and 350 Pa·s and η3 at a shear rate of 20 rpm between 100 and 5000 mPa·s.

[0104] In another embodiment, the retroreflective organic solvent composition prepared in step (b) has a first Brookfield viscosity η2 and a second Brookfield viscosity η3, which are measured at a temperature of 20°C using a #4 spindle in a 600 ml beaker having a diameter of 8.25 cm, with η3 being at least 2, 3, 4, or 5 times lower than η2, wherein η2 is at a shear rate of 0.5 rpm between 5 and 25 Pa·s, and η3 is at a shear rate of 20 rpm between 100 and 5000 mPa·s.

[0105] Process for preparing retroreflective organic solvent-based compositions The retroreflective organic solvent system composition prepared in step (b) can be prepared as follows. Generally speaking, the components of the retroreflective organic solvent system composition can be added in any order. However, since homogeneous distribution of components becomes more difficult in thickened compositions, it is preferable to add the thickener at the end of the process, after adding at least spherical glass beads to the organic solvent.

[0106] In the embodiment, the retroreflective organic solvent system composition prepared in step (b) is (i) Adding an organic solvent, spherical glass beads as defined above, a thickener as defined above, and one or more additional components of any choice as defined above to a container; and (ii) The mixture obtained in step (i) is prepared by stirring or homogenizing it at a temperature preferably between 15 and 70°C for a period of preferably between 5 and 60 minutes.

[0107] In a preferred embodiment, the thickener is added after stirring or homogenizing the mixture of the organic solvent and spherical glass beads. In another preferred embodiment, the thickener is added after stirring or homogenizing the mixture of the organic solvent, spherical glass beads and any further components. To avoid the incorporation of air bubbles, stirring or homogenization is preferably carried out at a low shear rate.

[0108] Therefore, the present invention is described with reference to certain embodiments discussed above. It will be recognized that these embodiments are readily adaptable to various modifications and alternative forms well known to those skilled in the art.

[0109] Furthermore, in order to properly understand this specification and its claims, it should be understood that the verb “includes” and its conjugations are used in a non-restrictive sense, meaning that the item following the word is included, but not excluded from items not specifically mentioned. Moreover, the reference of an element with the indefinite article “a” or “an” does not exclude the possibility that there are two or more of that element, unless the context clearly indicates that there is only one of that element. Therefore, the indefinite article “a” or “an” usually means “at least one.” [Examples]

[0110] Protocol viscosity measurement Viscosity was measured at a temperature of 20°C using a Brookfield Ametek® DV2T viscometer, following the operating instructions and using various standardized spindles (#1, #2, #3, #4, and #5; LV-1, LV-2, LV-3, LV-4, and LV-5, obtained from Brookfield Ametek®). Measurements were performed in a 600 ml flat-bottomed Griffin beaker with a diameter of 8.25 cm, without the use of protective legs. Before measuring viscosity, the sample was brought to 20°C and homogenized using stirring.

[0111] Example 1 Three retroreflective organic solvent-based compositions (compositions for the process according to the present invention, prepared in step (b)) were prepared by adding the components to a container (3.5 liters) at room temperature (approximately 20°C) in the following order and using Dispermill Orange-line 18 / 186. (1) Add the organic solvent and begin stirring at 500 rpm; (2) Add glass beads while mixing at 500 rpm for at least 5 minutes; (3) Add the first thickener while mixing at 1300 rpm for at least 5 minutes, and slowly increase the rpm to 2000 rpm without introducing air bubbles; (4) optionally add further thickeners and continue stirring at 1800 rpm for at least 45 minutes, and if necessary, slowly increase the rpm without introducing air bubbles; and (5) After the final setting of the thickening agent(s), the next day, the composition is stirred at approximately 2300 rpm for 15 minutes. The amounts of various components are listed in Table 1. The following components were used.

[0112] Spherical glass beads: "(AA)" microglass beads (RI 2.2), measured at a wavelength of 589 nm (λ), have a refractive index of approximately 2.2, and measured using laser diffraction, have a median particle size D50 of 26.56 μm, a D10 diameter of 19.77 μm, a D90 diameter of 32.41 μm, and weigh approximately 4.5 g / cm³. 3 These spherical glass beads were obtained from Jianxi Sunflex Light Retroreflective Material Co, Ltd., which has a specific gravity of [specific gravity]. These spherical glass beads contain TiO2, BaO, ZnO, and CaO.

[0113] Microglass beads (RI 2.2, HAC) obtained from "(BB)" Jianxi Sunflex Light Retroreflective Material Co, Ltd., have a refractive index of approximately 2.2 measured at a wavelength of 589 nm (λ), and measured using laser diffraction, have a median particle size D50 of 40.37 μm, a D10 diameter of 37.32 μm, a D90 diameter of 44.11 μm, and a weight of approximately 4.5 g / cm³. 3 Hemispherical, aluminum-coated glass beads with a specific gravity. These spherical glass beads contain TiO2, BaO, ZnO, and CaO.

[0114] Organic solvents Syrox S8000 thinner (Axalta) contains a mixture of organic solvents, 5-methylhexane-2-one, n-butyl acetate, 2,6-dimethylheptan-4-one, and 4,6-dimethylheptan-2-one. OK Thinner (Gamma, the Netherlands) Axalta's Chromax XB383 standard thinner contains a mixture of organic solvents, such as xylene, ethylbenzene, naphtha, 1,2,4-trimethylbenzene, mesitylene, n-propylbenzene, isopentyl acetate, n-butyl acetate, 2-methylbutyl acetate, and 4-methyl-2-pentanone.

[0115] Thickening agent F-CA (registered trademark) RM1920, obtained from BASF, hydrogenated castor oil, fine powder, thickener. Claytone 40, obtained from Byk, is an organic affinity phyllosilicate and thickener.

[0116] [Table 1]

[0117] Example 2 The stability of the three retroreflective organic solvent compositions shown in Table 1 was determined by visual and tactile testing to determine whether the sample exhibited sedimentation, synelysis, or separation (phase or other) immediately before resuspension, and whether the sample exhibited sedimentation, synelysis, or separation (phase or other) immediately after resuspension of the mixture. In addition, it was determined whether the sample remained stable and homogeneous for a sufficiently long time after resuspension.

[0118] As will be recognized by those skilled in the art, the limited sedimentation, (phase) separation, and / or synecessity of the retroreflective organic solvent-based compositions prepared in step (b) of the process according to the present invention is not a problem if the compositions can be resuspended and processed using, for example, simple stirring (i.e., mixed with the non-retroreflective organic solvent-based paste, ink, paint, or coating formulation prepared in step (a) of the process according to the present invention) to obtain compositions that remain stable and homogeneous for a sufficiently long time.

[0119] Resuspension was performed by vigorous mechanical stirring (without introducing air bubbles) for 5 minutes using a top-mounted agitator. The results of stability measurements immediately before and after resuspension are listed in Table 2a. Table 2a lists the sedimentation, synepheroidism, and "air bubble / aggregation" values ​​determined according to the classification shown in Table 2b.

[0120] [Table 2a]

[0121] [Table 2b]

[0122] The Brookfield viscosity of the three retroreflective organic solvent compositions shown in Table 1 (prepared in step (b) of the process according to the present invention) was determined using spindle #4 at 0.5 rpm and 20 rpm according to the protocol defined above. The results are shown in Table 2c. The three retroreflective organic solvent compositions exhibit shear viscosity reduction behavior.

[0123] [Table 2c]

[0124] Example 3 The three retroreflective organic solvent-based compositions of Example 1 (prepared in step (b) of the process according to the present invention) were used to prepare five different compositions selected from the group consisting of organic solvent-based pastes, inks, paints, or coating formulations having retroreflective properties.

[0125] The three retroreflective organic solvent compositions of Example 1 (prepared in step (b) of the process according to the present invention) were mixed with several commercially available products without retroreflective properties (prepared in step (a) of the process according to the present invention), which are listed in Table 3. The viscosities of the commercially available products are shown in Table 3.

[0126] [Table 3]

[0127] If necessary, additional thickeners (selected from the thickeners listed in Example 1) were added.

[0128] Five compositions selected from the group consisting of organic solvent-based pastes, inks, paints, or coating formulations having retroreflective properties were prepared by adding the components to a 600 ml beaker in the following order at room temperature (approximately 20°C) using a Dispermill Orange-line 18 / 186. (1) Add an organic solvent-based paste, ink, paint, or coating formulation (Table 3) that does not have retroreflective properties to a beaker and start stirring; (2) Add the retroreflective organic solvent composition (Table 1) to the beaker and continue stirring at 700-1500 rpm for about 10 minutes; (3) When adding additional thickeners, extend the stirring for each addition at approximately 1800 rpm for an additional 15 minutes; and (4) After the final setting of the thickener, the composition is stirred at approximately 1800-2500 rpm for 15 minutes the following day.

[0129] Table 4 lists the amounts of various components in the resulting organic solvent-based paste, ink, paint, or coating formulation having retroreflective properties (prepared in step (c) or (e) of the process according to the present invention).

[0130] [Table 4]

[0131] The stability of five different compositions selected from the group consisting of organic solvent-based pastes, inks, paints, or coating formulations having retroreflective properties (prepared in step (c) or (e) of the process according to the present invention) was determined by visual and tactile inspection to determine whether the sample exhibited sedimentation, synelysis, or separation (phase or otherwise) immediately before resuspension, and whether the sample exhibited sedimentation, synelysis, or separation (phase or otherwise) immediately after resuspension of the mixture. In addition, it was determined whether the sample remained stable and homogeneous for a sufficiently long time after resuspension.

[0132] As recognized by those skilled in the art, limited sedimentation, (phase) separation, and / or synecessation of organic solvent-based pastes, inks, paints, or coating formulations having retroreflective properties (provided in step (c) or (e) of the process according to the present invention) is not a problem if the composition can be resuspended, for example, using simple stirring, to obtain a composition that remains stable and homogeneous for a sufficiently long time to be processed (i.e., applied to a substrate of interest).

[0133] Resuspension was performed by vigorous mechanical stirring for 5 minutes using a top-mounted agitator (without introducing air bubbles). The results of stability measurements immediately before and after resuspension are listed in Table 5. Table 5 lists the sedimentation, synepheroidism, and "air bubble / aggregation" values ​​determined according to the classification shown in Table 2b.

[0134] [Table 5]

[0135] Example 4 Five different compositions selected from the group consisting of organic solvent-based pastes, inks, paints, or coating formulations having retroreflective properties disclosed in Table 4 were applied to the corresponding "purposes" disclosed in Table 3 using the corresponding "application methods" disclosed in Table 3, resulting in visually attractive coated substrates with retroreflective properties.

[0136] Comparative Example Five comparative retroreflective compositions were prepared by directly mixing a composition selected from the group consisting of organic solvent-based pastes, inks, paints, or coating formulations (as defined in Example 3) with spherical glass beads as defined in Example 1. The comparative retroreflective compositions were prepared as follows: A commercially available organic solvent-based paste, ink, paint, or coating formulation without retroreflective properties was placed in a beaker. Spherical glass beads were then added, and the mixture was thoroughly mixed using a Dispermill Orange-line 18 / 186 at 1000-2100 rpm for 7-10 minutes. The process was carried out at room temperature (approximately 20°C). The amounts of various components in the resulting comparative compositions are listed in Table 6.

[0137] [Table 6]

[0138] The stability of five comparative retroreflective compositions was evaluated seven days after preparation. Table 7 lists the sedimentation, synelysis, and "air bubbles / aggregation" values ​​for the five comparative retroreflective compositions, determined according to the classification shown in Table 2b. The samples showed moderate to severe sedimentation, and as a result, they (samples T01236, T01237, and T01240) could not be resuspended or could hardly be resuspended (T01238 and T01239). Furthermore, sample T01239 showed air bubbles and agglutination.

[0139] [Table 7]

Claims

1. A method for providing a composition selected from the group consisting of organic solvent-based pastes, inks, paints, and coating formulations having retroreflective properties, a) From 1 mPa·s measured using a #1 spindle in a 600 ml beaker with a diameter of 8.25 cm Brookfield viscosity η at 20°C and a shear rate of 0.5 rpm and a temperature of 300 Pa·s, measured using a #5 spindle in a 600 ml beaker with a diameter of 8.25 cm. １ A step of preparing an organic solvent-based paste, ink, paint, or coating formulation that has no retroreflective properties; b) First Brookfield viscosity η ２ and the second Brookfield viscosity η ３ The value was measured in a 600 ml beaker with a diameter of 8.25 cm at a temperature of 20°C using a #4 spindle, and η ３ ga η ２ Provided that it is at least twice as low as η at a shear rate of 0.5 rpm between 5 and 350 Pa·s, η ２ , and η at a shear rate of 20 rpm between 100 and 5000 mPa·s ３ A step of preparing a retroreflective organic solvent-based composition having, The retroreflective organic solvent system composition is based on the total weight of the retroreflective organic solvent system composition. 10 to 49.85% by weight of organic solvent; 50–85 wt% spherical glass beads having a median particle size D50 between 1 and 1500 μm as measured by laser diffraction, and a refractive index between 1.5 and 2.8 as measured at a wavelength λ of 589 nm; 0.15 to 3.5% by weight of a thickening agent; and A step consisting of 0 to 10% by weight of one or more further components; c) A step of preparing an organic solvent-based paste, ink, paint, or coating formulation having retroreflective properties by mixing the organic solvent-based ink, paint, or coating formulation without retroreflective properties prepared in step (a) with the retroreflective organic solvent-based composition prepared in step (b) in a weight ratio between 30:70 and 70:30; d) optionally mixing the organic solvent-based paste, ink, paint, or coating formulation having retroreflective properties obtained in step (c) with synthetic pigment flakes having an average diameter between 5 and 150 μm, a thickness of less than 1 μm, and an aspect ratio of at least 10, in an amount of 0 to 4.5% by weight, based on the total weight of the organic solvent-based paste, ink, paint, or coating formulation having retroreflective properties obtained in step (c); and e) A method comprising the optional step of mixing the mixture obtained in step (c) or (d) with 0 to 3% by weight of a thickener, based on the total weight of the organic solvent-based paste, ink, paint or coating formulation having retroreflective properties obtained in step (c) or (d), respectively.

2. The retroreflective organic solvent system composition prepared in step (b) is based on the total weight of the retroreflective organic solvent system composition. 15–49.85% by weight of organic solvent; 50–80 wt% spherical glass beads having a median particle size D50 measured using laser diffraction between 5 and 1500 μm, and a refractive index measured at a wavelength λ of 589 nm between 1.5 and 2.8; 0.15 to 3.5% by weight of a thickening agent; and The method according to claim 1, comprising 0 to 10% by weight of one or more further components.

3. The retroreflective organic solvent-based composition prepared in step (b) has a first Brookfield viscosity η ２ and a second Brookfield viscosity η ３ which are measured at a temperature of 20 °C using a #4 spindle in a 600 ml beaker having a diameter of 8.25 cm as η ３ is η ２ is at least four times lower than η, and η at a shear rate of 0.5 rpm of 8 to 325 Pa·s ２ and η at a shear rate of 20 rpm between 110 and 4000 mPa·s ３ The method according to claim 1, having.

4. The organic solvent-based paste, ink, paint, or coating formulation prepared in step (a) that does not have retroreflective properties, Measured using a #1 spindle in a 600 ml beaker with a diameter of 8.25 cm, from 5 mPa·s Brookfield viscosity η at a shear rate of 0.5 rpm and a temperature of 20°C, measured using a #5 spindle in a 600 ml beaker with a diameter of 8.25 cm. １ The method according to claim 1, comprising:

5. The spherical glass beads in the retroreflective organic solvent composition prepared in step (b) (i) between 2.0 and 2.8; or (ii) The method according to claim 1, having a refractive index measured at a wavelength λ of 589 nm between 1.7 and 2.

1.

6. The method according to claim 1, wherein the spherical glass beads in the retroreflective organic solvent composition prepared in step (b) have a median particle size D50, as measured by laser diffraction, between 1 and 100 μm, between 1 and 75 μm, between 1 and 50 μm, between 1 and 45 μm, between 1 and 40 μm, or between 1 and 35 μm.

7. The method according to claim 1, wherein the spherical glass beads in the retroreflective organic solvent composition prepared in step (b) have a median particle size D50, as measured by laser diffraction, between 5 and 100 μm, between 5 and 75 μm, between 5 and 50 μm, between 5 and 45 μm, between 5 and 40 μm, or between 5 and 35 μm.

8. The method according to claim 1, wherein at least a portion of the spherical glass beads in the retroreflective organic solvent composition prepared in step (b) are hemispherical coated with an aluminum coating.

9. The method according to claim 1, wherein the organic solvent in the retroreflective organic solvent system composition prepared in step (b) is selected from the group consisting of aliphatic and aromatic solvents, ketones, esters, glycol ethers, alcohols, halogenated hydrocarbons and combinations thereof.

10. The method according to claim 1, wherein the thickener in the retroreflective organic solvent composition prepared in step (b) is selected from the group consisting of (modified) hydrogenated castor oil, clay, modified clay, calcium sulfonate complex, organic affinity phyllosilicate, silica gel, synthetic amorphous silica, acrylic acid type gelling agent, modified cellulose-based material, polyurea dispersion, solution of urea-modified polyamide, polyurethane dispersion, and combinations thereof.

11. The method according to claim 1, wherein the amount of the thickener in the retroreflective organic solvent composition prepared in step (b) is 0.20 to 3.0% by weight, based on the total weight of the retroreflective organic solvent composition prepared in step (b).

12. The method according to claim 1, wherein one or more further components in the retroreflective organic solvent composition prepared in step (b) are selected from the group consisting of foam control agents, preservatives, dyes, curing initiators, luminescent agents, pigments, UV absorbers, binders, and resins.

13. The method according to claim 1, wherein steps (c), (d), and / or (e) are carried out at a temperature between 15 and 30°C with stirring.

14. The method according to claim 1, wherein step (c) is to add the retroreflective organic solvent composition prepared in step (b) to the non-retroreflective organic solvent paste, ink, paint or coating formulation prepared in step (a).

15. The method according to claim 1, wherein in step (c), the non-retroreflective organic solvent-based paste, ink, paint, or coating formulation prepared in step (a) is mixed with the retroreflective organic solvent-based composition prepared in step (b) in a weight ratio between 40:60 and 60:

40.

16. The method according to claim 1, wherein in step (e), the mixture obtained in step (c) or (d) is mixed with a thickener in an amount of 0 to 2.5% by weight, 0 to 2.0% by weight, 0 to 1.8% by weight, 0 to 1.6% by weight, 0 to 1.5% by weight, 0 to 1.4% by weight, or 0 to 1.3% by weight, based on the total weight of the organic solvent-based paste, ink, paint, or coating formulation having retroreflective properties obtained in step (c) or (d), respectively.

17. The method according to any one of claims 1 to 16, further comprising the step of applying the organic solvent-based paste, ink, paint, or coating formulation having retroreflective properties obtained in step (c), (d), or (e) to a substrate using screen printing, spray coating, curtain coating, or spray painting.

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