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BR-112022016758-B1 - METHOD FOR PROVIDING A SELECTED COMPOSITION FROM THE GROUP CONSISTING OF AQUEOUS PASTES, DYES, INKS AND COATING FORMULATIONS WITH RETROREFLECTIVE PROPERTIES

BR112022016758B1BR 112022016758 B1BR112022016758 B1BR 112022016758B1BR-112022016758-B1

Abstract

METHOD FOR PROVIDING A SELECTED COMPOSITION FROM THE GROUP CONSISTING OF AQUEOUS PASTES, DYES, INKS AND COATING FORMULATIONS WITH RETROREFLEXIVE PROPERTIES. The invention relates to a method for providing a selected composition from the group comprising aqueous pastes, inks, dyes and coating formulations with retroreflective properties, and said method comprises the steps of: a) providing an aqueous paste, dye, ink or coating formulation without retroreflective properties, said aqueous paste, dye, ink or coating formulation having a viscosity ε1 between 0.25 and 1000 Pa^s at a shear rate of 0.01 s-1; b) providing an aqueous pseudoplastic gel composition comprising a thickener; c) mix the aqueous paste, dye, ink or coating formulation provided in step (a) with the aqueous pseudoplastic gel composition provided in step (b) in a weight ratio between 30:70 and 70:30; and d) mix the mixture obtained in step (c) with 0–2% by weight based on the total weight of the aqueous paste, dye, ink or coating formulation with retroreflective properties of a thickener.

Inventors

  • JACQUES ARTHUR KNOOTE
  • PAUL WILLEM MIJNEN
  • HARALD PAUL KERRES
  • PHILIPPUS JACOB MUIS
  • MENNO ARTHUR KNOOTE

Assignees

  • INK INVENT IP B.V

Dates

Publication Date
20260317
Application Date
20210224
Priority Date
20200225

Claims (13)

  1. 1. METHOD FOR PROVIDING A SELECTED COMPOSITION FROM THE GROUP CONSISTING OF AQUEOUS PASTES, DYES, INKS AND COATING FORMULATIONS WITH RETROREFLEXIVE PROPERTIES, said method characterized by comprising the steps of: a) providing an aqueous paste, dye, ink or coating formulation without retroreflective properties, said aqueous paste, dye, ink or coating formulation having a viscosity n1 between 0.25 and 1000 Pa·s at a shear rate of 0.01 s⁻¹; b) providing an aqueous pseudoplastic gel composition with a first viscosity n2 at a shear rate of 0.01 s⁻¹ between 5 and 250 Pa·s, and a second viscosity n3 at a shear rate of 100 s⁻¹ which is between 10 and 1000 times lower than the first viscosity n2, in which the aqueous pseudoplastic gel consists, based on the total weight of the aqueous pseudoplastic gel composition, of: • 15 — 39.85% by weight of water; • 60 — 80% by weight of spherical glass granules with a median particle diameter D50, as measured by laser diffraction, between 5 and 1500 μm, and a refractive index measured at a wavelength λ of 589 nm between 1.8 and 2.8, in which optionally at least part of the spherical glass granules are hemispherically coated with a light-reflecting coating; • 0.15 — 2.5% by weight of a thickener; e) 0 - 5% by weight of one or more other ingredients; c) mix the aqueous paste, dye, ink or coating formulation provided in step (a) with the aqueous pseudoplastic gel composition provided in step (b) in a weight ratio between 30:70 and 70:30; d) mix the mixture obtained in step (c) with 0 - 2% by weight based on the total weight of the aqueous paste, dye, ink or coating formulation with retroreflective properties of a thickener to provide an aqueous paste, dye, ink or coating formulation with retroreflective properties, wherein the viscosities n1, n2 and n3 are measured with a rheometer with a plate-plate geometry and a gap distance of 0.5 mm at a temperature of 25°C.
  2. 2. METHOD, according to claim 1, characterized in that the aqueous pseudoplastic gel composition provided in step (b) has a third viscosity n 4 at a shear rate of 0.1 s-1, wherein the aqueous pseudoplastic gel composition recovers at least 20%, preferably at least 30%, more preferably at least 50%, even more preferably at least 70% of the value of the third viscosity n 4 in 10 s, preferably in 5 s, more preferably in 2 s from the reduction of the shear rate in step (iii) of the following process comprising the consecutive steps of: (i) subjecting the aqueous pseudoplastic gel composition to a shear rate of 0.1 s-1 for at least 30 seconds and measuring the third viscosity n 4; (ii) subjecting the aqueous pseudoplastic gel composition to a shear rate of 100 s-1 for 30 seconds; (iii) reduce the shear rate to 0.1 s-1; and (iv) measure the viscosity of the aqueous composition of pseudoplastic gel as a function of time.
  3. 3. METHOD, according to claim 1 or 2, characterized by the aqueous pseudoplastic gel composition provided in step (b) having tan(δ) values measured with a rheometer with a plate-plate geometry and a gap distance of 0.5 mm at a temperature of 25°C at oscillatory frequencies between 10 and 0.1 Hz that are less than 1, preferably between 0.05 and 0.9, more preferably between 0.1 and 0.8.
  4. 4. METHOD, according to any one of claims 1 to 3, characterized in that the spherical glass beads in the aqueous pseudoplastic gel composition provided in step (b) have a refractive index measured at a wavelength λ of 589 nm between 1.9 and 2.6, preferably between 1.9 and 2.2.
  5. 5. METHOD, according to any one of claims 1 to 4, characterized in that the aqueous pseudoplastic gel composition provided in step (b) comprises 0.20 - 2.45% by weight, preferably 0.40 - 2.25% by weight, more preferably 0.75 - 2.10% by weight, based on the total weight of the aqueous pseudoplastic gel composition of the thickener.
  6. 6. METHOD, according to any one of claims 1 to 5, characterized in that the thickener in the aqueous pseudoplastic gel composition provided in step (b) is chosen from the group consisting of ASE polymers, HASE polymers, HEUR polymers, crosslinked liquid acrylic dispersions or copolymers, acrylate crosspolymers, crosslinked polyacrylic acid polymers, crosslinked polyacrylic acid copolymers, nonionic aqueous emulsions of a modified ethylene vinyl acetate copolymer wax, modified urea or urea-modified polyamides and combinations thereof.
  7. 7. METHOD, according to any one of claims 1 to 6, characterized in that the aqueous paste, dye, ink or coating formulation with retroreflective properties obtained in step (d) is stable and homogeneous for at least 1 day, wherein the composition is considered stable and homogeneous if, after visual and tactile inspection, no sedimentation, syneresis or separation can be observed and wherein, after inspection with a microscopic camera, no air inclusions can be visually observed.
  8. 8. METHOD, according to any one of claims 1 to 7, characterized in that steps (c) and (d) are carried out at a temperature between 15 and 30°C, preferably for a period of at least 5 minutes.
  9. 9. METHOD, according to any one of claims 1 to 8, characterized in that, in step (c), the aqueous paste, dye, ink or coating formulation provided in step (a) is preferably mixed with the aqueous pseudoplastic gel composition provided in step (b) in a weight ratio between 60:40 and 40:60, more preferably in a weight ratio between 45:55 and 55:45.
  10. 10. METHOD, according to any one of claims 1 to 9, characterized in that, in step (d), the mixture obtained in step (c) is mixed with 0 - 1.9% by weight, 0 - 1.8% by weight, 0 - 1.7% 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 aqueous paste, dye, ink or coating formulation with retroreflective properties of the thickener.
  11. 11. METHOD, according to any one of claims 1 to 9, characterized in that, in step (d), the mixture obtained in step (c) is mixed with 0.1 - 2.0% by weight, 0.2 - 2.0% by weight, 0.3 - 2.0% by weight, 0.4 - 2.0% by weight, or 0.5 - 2.0% by weight, based on the total weight of the aqueous paste, dye, ink, or coating formulation with retroreflective properties of the thickener.
  12. 12. METHOD, according to any one of claims 1 to 11, characterized by further comprising the step of applying the aqueous paste with retroreflective properties obtained in step (d) to a substrate using screen printing, spray coating or spray painting.
  13. 13. METHOD, according to any one of claims 1 to 12, characterized in that the aqueous pseudoplastic gel composition as provided in step (b) is prepared using a process comprising the steps of: (A) adding water, spherical glass beads, thickener and one or more optional additional ingredients to a container; (B) mixing or homogenizing the mixture obtained in step (A), preferably at a temperature between 15 and 30°C, preferably for a period between 5 and 15 minutes; and (C) optionally adjusting the pH before or after step (B), preferably to a value between 6.0 and 11.

Description

DOMAIN OF THE INVENTION [001] The invention relates to a method for providing a composition selected from the group comprising aqueous pastes, inks, dyes and coating formulations with retroreflective properties. The invention further relates to said method which also comprises the step of applying the retroreflective composition to a substrate. HISTORY OF THE INVENTION [002] Retroreflective effects are used in a variety of applications. For example, to improve the visibility of traffic signs, road markers, textiles, cars, etc. in dark conditions, or simply to improve their visual appearance. Road markers are typically provided with retroreflective properties by the addition of spherical glass beads with a specific refractive index. Retroreflection occurs through the combined action of the refraction of incident light through the upper surface of a spherical glass bead, the internal reflection from the lower lateral surface of the spherical glass bead, and the subsequent refraction of light as it exits the upper surface of the spherical glass bead and returns to the direction from which the incident light came. [003] Document WO00/42113A1 refers to retroreflective inks comprising microspheres in a liquid carrier medium. The liquid carrier medium may be water. The inks are intended for screen printing. [004] Document WO2004/017104A2 discloses retroreflective compositions comprising retroreflective microspheres, a binder system and a thixotropic mixture comprising at least two thixotropic agents in an amount of about 2 to about 5% by weight based on the retroreflective composition. The composition may comprise water. The retroreflective compositions are intended for use as dyes, inks and coatings, and are applied to a substrate using aerosol applicators with a propellant. [005] Water-based pastes, tints, inks, and coating formulations are commercially offered by many suppliers in different colors and/or adapted for different applications. Each new application and each modification of a water-based paste, tint, ink, or coating formulation requires an expensive and time-consuming development process, from laboratory sample to commercial product. Obviously, offering many products in different colors and/or for different applications requires a large warehouse and large stocks that can quickly meet customer orders. [006] As described above, adding retroreflective properties to pastes, dyes, inks, and coating formulations can be advantageous, as it results in improved visibility and/or a more attractive visual appearance. Developing retroreflective versions of commercially available aqueous pastes, dyes, inks, and coating formulations also requires an expensive and time-consuming development process, since adding additional components, including retroreflective spherical glass beads, must not adversely affect the processability of the existing paste, dye, ink, or coating formulation, let alone the properties of the paste, dye, ink, or coating formulation after drying or curing. Offering retroreflective pastes, dyes, inks, and coating formulations, in addition to pastes, dyes, inks, and coating formulations without retroreflective properties, requires an even larger warehouse. [007] Consequently, there is a need for an efficient method to supply, on demand, aqueous pastes, dyes, inks and coating formulations, i.e., commercially available aqueous pastes, dyes, inks and coating formulations with retroreflective properties without substantially altering the processability of the aqueous dyes, inks and coating formulations and without adversely affecting the properties of the paste, dye, ink or coating formulation after drying or curing. [008] The inventors have established that the supply of aqueous pastes, dyes, inks and coating formulations with a viscosity between 0.25 and 1000 Pa^s at a shear rate of 0.01 s-1, as measured with a rheometer with a plate-plate geometry and a gap distance of 0.5 mm at a temperature of 25°C with retroreflective properties, cannot be implemented simply by mixing the aqueous paste, dye, ink or coating formulation with spherical glass beads because this results in lack of homogeneity, air inclusion and/or instability with respect to the distribution of the spherical glass beads throughout the composition. [009] Therefore, it is an object of the present invention to provide an efficient method for providing aqueous pastes, dyes, inks and coating formulations with retroreflective properties without substantially altering the processability of the aqueous pastes, dyes, inks and coating formulations and without adversely affecting the properties of the paste, dye, ink or coating formulation after drying or curing. [0010] Another objective of the present invention is to provide an efficient method for providing aqueous pastes, tinctures, inks and coating formulations with retroreflective spherical glass beads that result in a homogeneous and stable distribution of the retroreflective spherical