MXPA99005554A - Curable ink composition - Google Patents

Abstract

Radiation curable ink compositions and coating compositions contain an aliphatic (meth)acrylate functional macromonomer, a reactive acrylate monomer, and a photoinitiator. Ink compositions also contain an effective amount of a colorant or pigment. These inks, when cured by exposure to actinic radiation, have excellent durability, weatherability, and adhesion to acrylate substrates such as polymethylmethacrylate.

Description

COMPOSITION OF CURABLE INK FIELD OF THE INVENTION This composition is directed to ink compositions which are curable by exposure to actinic radiation such as ultraviolet radiation and which contain an aliphatic acrylate functional macromonomer. The invention is also directed to coating protective compositions containing these macromonomers.

BACKGROUND OF THE INVENTION It is generally known in the art to use actinic radiation, such as ultraviolet radiation, to cure ink compositions. Ultraviolet radiation can be used to cure various types of inks, such as thiolene inks, inks made of aryldiazonium salts and epoxy resins, and inks containing acrylates including acrylated epoxy materials and urethanes. Of these, acrylate-containing inks are often preferred because they are available at a reasonable cost and have good storage stability in addition to their useful properties as inks. REF .: 30587 UV curable inks of the acrylate type typically consist of a pigment dispersed in a reactive base which may contain photoinitiators, reactive monomers or oligomers, preservatives, flow improvers and the like. The properties of the ink such as viscosity, brightness and crosslink density can be controlled by varying the types and / or proportions of reactive diluents used in the formulation. Radlove et al. , in U.S. Patent No. 3,856,744 describes photo-polymerizable ink compositions comprising an ethylenically unsaturated beta-hydroxy ester, a polyitaconate, and optionally a polyacrylate which functions as a reactive diluent. The Radlove compositions should contain 2 to 10% by weight of the polyitaconate. In U.S. Patent No. 4,826,890 Gupta discloses radiation curable coating compositions comprising a copolymer of dialkyl muconate and p-acetoxystyrene, a polymerizable compound by polyethylenically unsaturated radiation and optionally a monoethylenically unsaturated monomer such as an acrylate or methacrylate. Additional examples of radiation curable coatings are found in Wojnarowicz, EP 457 499; Kistner, U.S. Patent No. 4,668,601; Liu et al., U.S. Patent No. 5,106,885; and Hesse et al., U.S. Patent No. 4,265,723. Macromonomers, also known as high molecular weight monomers, are large molecules made up of repeating monomer units and ending in a polymerizable end group. These large monomers have been used for a long time in the preparation of graft copolymers to provide side chains or uniform branches. Milkovich, in U.S. Patent Nos. 3,786,116 and 3,842,059 are examples of the use of macromonomers in the synthesis of graft copolymers. Macromonomers containing acrylate are known, as can be seen, for example, in Mori, U.S. Patent No. 5,147,952. Attempts have been made to incorporate macromonomers into UV curable inks. In EP 187,045, Kerr describes the use of macromonomers in the preparation of radiation curable printing inks. The macromonomers used by Kerr have a repeating unit which is an aromatic vinyl monomer. Properties such as storage stability, adhesiveness, durability and so on are attributed by Kerr to the large mass of the vinyl aromatic part in the macromonomer. However, compositions containing high proportions of an aromatic monomer may have certain undesirable properties. For example, these compositions may be vulnerable to degradation by ultraviolet light, resulting in poor durability and short product life for applications where significant outside exposure is required. Ink compositions containing aromatic macromonomer may not adhere well to non-aromatic polymeric substrates such as polymethyl methacrylate, rendering them less suitable for use in constructions containing such materials. There is a need for radiation curable ink compositions that are durable, resistant to ultraviolet light once they cure and adhere well to acrylate substrates.

BRIEF DESCRIPTION OF THE INVENTION The invention provides a radiation curable ink consisting of a functional macromonomer of aliphatic acrylate; a reactive acrylate monomer; an effective amount of a colorant; and an effective amount of a photoinitiator. These inks provide good resistance to ultraviolet light once they have cured, they have excellent adhesion to acrylate film substrates such as polymethyl methacrylate, and can be transparent or opaque.

The invention further provides a radiation curable coating comprising an aliphatic acrylate functional macromonomer; a reactive acrylate monomer; and an effective amount of a photoinitiator. The radiation curable coatings according to the invention provide a durable protective layer for a wide variety of substrates. As used herein, the term "aliphatic" includes all acyclic or non-aromatic cyclic functionalities. The aliphatic portions may be saturated or unsaturated, and may be substituted. The macromonomers used of the invention comprise one or more aliphatic repeat units and have a polymerizable end group. These macromonomers generally have an average molecular weight number of about 3,000 to 15,000. The durability and ultraviolet light resistance of the inks makes them particularly useful in applications where outdoor use is considered, such as in retroreflective laminate imaging for durable traffic signal applications. The coating of the invention can be used alone or in combination with the ink to provide additional protection from ultraviolet light and resistance to weathering.

DETAILED DESCRIPTION OF THE INVENTION The macromonomer component of the ink composition is an aliphatic molecule having an average molecular weight number (Mn) of about 3,000 to 15,000, preferably from about 6,000 to 10,000, which is composed of one or more aliphatic repeat units and which has a polymerizable end group. The inclusion of such a macromonomer improves the adhesion of the ink to acrylate type films such as polymethyl methacrylate (PMMA) and also provides good solvent resistance properties. The repeated units that make up the macromonomer are aliphatic, that is, they do not contain any aromatic functionality. These cyclic or acyclic aliphatic repeat units may be saturated or unsaturated and may be substituted as desired with non-aromatic substituent groups. Examples of suitable repeating groups include ethylenically unsaturated aliphatic carboxylic acids, esters and other groups that will not interfere with the curing of the ink. Of these, ethylenically unsaturated acids such as acrylic acid and methacrylic acid are among the preferred repeating groups in the macromonomer component of the inks. The repeating groups found in the macromonomer may be the same or different.

The polymerizable end group of the macromonomer is typically an aliphatic, ethylenically unsaturated group that is capable of reaction with one or more reactive acrylate monomers used to prepare the inks. This reactive functionality allows the macromonomer to be crosslinked directly on certain film substrates by free radical polymerization initiated by exposure to ultraviolet radiation. Examples of end groups useful for the macromonomer include ethylenically unsaturated carboxylic acids, such as acrylic and methacrylic acid. Preferred macromonomers include compounds of the formula (I) or (II): (I) R- (RI) n- (CH2) 1_5-R2-X (II) R- (RI) n-X wherein R is H, C1.20 alkyl which may be straight or branched chain, or C4 alkoxy or which may be straight or branched chain; R2 is C- ^ alkyl or which may be linear or branched and which may be interrupted by one or more bonds -CONR3-, -NR3CO- -COO- or -OCO-; Rl is R3 C ((| H2) 0.6 COOR4 wherein R3 and R4 are each independently H or C-L.g alkyl which may be straight or branched chain; X is -O-CO-C = CH ¿_ wherein R5 is H or C6 alkyl; and n is a number sufficient to provide the desired molecular weight, typically from about 10 to 210. Preferred macromonomers are those which have a repeating unit of methyl methacrylate, isobutyl methacrylate or isobutyl methacrylate / isooctyl acrylate. Especially preferred macromonomers have a methyl / methacrylate repeating unit and an end group of methacrylic acid. Suitable methyl methacrylate macromonomers are commercially available as AA-10 and AA-6 macromonomer resins from Toagosei Co. LTD, Tokyo Japan, and the ELVACITE EP-M1010 macromonomer resin from ICI Acrylics, Inc., Wilmington, DE. The macromonomer is present in the inks of the invention in an amount effective to provide the ink with the desired properties of adhesion, resistance to decomposition to the weather and to solvents that are desired. Generally, the macromonomer constitutes about 10 to 60% by weight of the ink, preferably about 10 to 60% by weight, much more preferably 25 to 35% by weight. One or more reactive acrylate monomers are present in the ink compositions. These reactive monomers function as diluents or solvents for the macromonomer and other components; as pigment binders, and as viscosity reducers and as crosslinking agents. In general, any ester of a mono- or poly-carboxylic acid ethylenically unsaturated, substituted or unsubstituted, radiation curable, can be used as a reactive acrylate component of the ink composition. Preferably, the acrylate monomer has a terminal vinyl group, and more preferably has a group O -O- -_- CH = CH2 terminal. Particularly preferred reactive acrylate monomers include hexanediol diacrylate, tetrahydrofurfuryl acrylate, isobornyl acrylate, ethoxyethoxyethyl acrylate, propoxylated neopentyl glycol diacrylate and trimethylolpropane triacrylate. The reactive acrylate monomer, or the combined reactive acrylate monomers generally constitute from about 25 to 70% by weight of the ink composition, preferably from about 40 to 60% by weight, and much more preferably from 45 to 60% by weight. 55% by weight. If a mixture of reactive acrylate monomers is used, the amount of each monomer used may vary as necessary to provide the final composition with the desired combination of properties. A non-reactive solvent may be included in the ink, if desired, to provide properties such as improved flow or wetting. Examples of such solvents include organic solvents such as ethanol, isopropanol, methyl ethyl ketone, and the like. The pigment used in the ink composition provides the desired color. Durable pigments are preferred for use in the inks of the invention, which means that they have good exterior durability and resist a color change or instability upon exposure to the sun and the elements. The pigments useful in the invention may be organic or inorganic. Suitable inorganic pigments include carbon black and titanium oxide (Ti02), while suitable organic pigments include phthalocyanines, anthraquinones, perlenes, carbazoles, monoazo- and disazobenzimidazolone, isoindolinones, monoazonaphthol, diarylpyrazolone, rhodamine, indigoid, quinacridone, diazopirantrone, dinitraniline, pyrazolone, dianisidine, pyrantrone, tet racloroisoindol inona, dioxazine, monoazoacrilide, anthrapyrimidine. It will be recognized by those skilled in the art that the organic pigments will be matted differently, or will even have different colors based on the functional groups attached to the parent molecule. Commercial examples of useful organic pigments include those known under the trade designations PB 1, PBl 15, PB 15: 1, PB 15: 2, PB 15: 3, PB 15: 4, PB 15: 6, PB 16, PB 24, and PB 60 (blue pigments); PB 5, PB 23 and PB 25 (brown pigments); PY 3; PY 14, PY 16, PY 17, PY 24, PY 65, PY 73, PY 74, PY 83, PY 95, PY 97, PY 108, PY 109, PY 110, PY 113, PY 128, PY 129, PY 138, PY 139, PY 150, PY 154, PY 156 and PY 175 (yellow pigments); PG 1, PG 7, PG 10 and PG 36 (green pigments); PO 5, PO 15, PO 16, PO 31, PO 34, PO 36, PO 43, PO 48, PO 51, PO 60 and PO 61 (orange pigments); PR 4, PR 5, PR 7, PR 9, PR 22, PR 23, PR 48, PR 48: 2, PR 49, PR 112, PR 122, PR 123, PR 149, PR 166, PR 168, PR 170, PR 177, PR 179, PR 190, PR 202, PR 206, PR 207, and PR 224 (red); PV 19; PV 23, PV 37, PV 32 and PV 42 (violet pigments); and PBLAC (black). The pigment is generally incorporated into the ink composition by grinding the pigment into selected reactive monomers or macromonomer resin. If the ink is to be used in applications where the ink is used in combination with a retroreflective backing, the pigment can be ground to a particle size that provides sufficient transparency to allow retroreflection and provide a retroreflective color. This can be done, for example, by grinding the pigment. Although the precise size will vary with the nature of the pigment used, grinding the pigment to a particle size of about 10 to 100 nm will provide the desired transparency. An effective amount of pigment is used to provide the desired color and intensity to the ink. In general, about 1 to 15% by weight of pigment is present in the ink compositions in the ink. The exact amount used will vary based on the pigment used and the color you want. A photoinitiator is included in the inks to allow the composition to cure upon exposure to actinic radiation such as ultraviolet radiation. Any of the photoinitiators known in the art can be used, such as photoinitiators of alpha separation type or hydrogen abstraction. Preferred photoinitiators include the brand IRGACURE 184, 651, 369, 1700, 1800 and 1850 and the trademark DAROCUR 1173 and 4265 of Ciba-Geigy Inc., Ardsey, NY. The photoinitiator is present at concentrations sufficient to cause the compositions to cure, typically at about 1 to 6% by weight, preferably 2 to 6% by weight of the ink composition. Other additives may be present in the ink compositions of the invention to provide additional properties as desired. If used, such additives can be reactive with the macromonomer but should not adversely affect the curing of the ink. Examples of such additives include flow agents, leveling agents, viscosity modifiers, antioxidants, hindered amine light stabilizers (HALS), moisture scavengers, ultraviolet light absorbing substances (UVA) and the like. If used, these additives are present individually in amounts ranging from about 0.5 to 5% by weight of the ink composition. The inks of the invention are prepared by combining the selected pigment with one or more acrylate monomer or macromonomer resins by a grinding process, creating a ground base or dispersion. The pigment can generally be added as a paste dispersion or as a solid dispersion of chips or powder. The macromonomer, if it is in non-liquid form, can be dissolved in an appropriate amount of reactive acrylate monomer. The ground base and the macromonomer solution are subsequently combined with any additional reactive acrylate monomer, photoinitiators and other ingredients. These components can be combined in any effective order with agitation between additions. They can also be mixed together in a single stage process of "a container" in a reaction vessel. The method of preparing "a container" is generally preferred. In this method, the pigment is first milled in triple rolls until the monomer or liquid monomers form a paste, or two roll mills in a solid resin, forming a dispersion of chips or powder. The additional monomers are added to the mixing vessel, with stirring. All the resulting ingredients are added, except the photoinitiator to the container, with moderate agitation. When all the ingredients have been added, the mixing speed is increased to the high condition, until all the solids are dissolved and a homogeneous solution is obtained. The mixing speed is adjusted as needed to maintain the mixture at a constant temperature. After the mixing speed is decreased, the solution is protected from the light and the photoinitiator is added with mixing at moderate speed until it is fully incorporated. This method, with the pigment added as a solid dispersion of chips or powder, is particularly preferred. The procedure followed for the two stage preparation method will vary based on the type of pigment dispersion added. If the pigment is added as a paste dispersion, the pigment is milled on a triple roll until the liquid monomers form a paste. The solid macromonomer resin is stirred at high speed in a sufficient amount of liquid monomers to dissolve the macromonomer and form a viscous liquid. The pigment and the viscous liquid are combined with all the remaining ingredients except the photoinitiator and are stirred until a homogeneous solution is obtained. After the mixing speed is decreased, the solution is protected from the light and the photoinitiator is added with mixing at moderate speed until they are fully incorporated. If the pigment is added as a solid dispersion of chips or powder, then the pigment is milled on two rolls in a sufficient amount of solid macromonomer resin to form a chip or powder dispersion. This dispersion is mixed at high speed in a sufficient quantity of liquid monomers to dissolve the macromonomer and obtain a viscous and homogeneous pigment solution. The remaining macromonomer is stirred at high speed in a sufficient amount of liquid monomers to dissolve the macromonomer and form a viscous liquid. The pigment solution, the viscous macromonomer solution and all the ingredients, except the photoinitiator, are combined and mixed until a homogeneous solution is obtained. The mixing speed is decreased, the solution is protected from light and the photoinitiator is added with mixing at moderate speed until it is fully incorporated. Generally, the radiation curable inks of the composition are used by screen printing the ink on the desired article or substrate and by subjecting the ink layer to radiation such as ultraviolet radiation to carry out the curing. The ink can be used to form any desired image. For example, the image may be selective or discrete, such as a text, alphanumeric symbols, graphic symbols or designs and the like, or the ink may form a continuous layer across the entire surface of the substrate. A preferred substrate is a retroreflective laminate such as retroreflective laminates of encased or encapsulated lenses including retroreflective laminates of the microsphere type or cube corner type. Laminates of illustrative encapsulated lenses are described in the patents of. United States numbers 3,190,178; 4,025,159; 4,896,943; 5,064,272 and 5,066,098, all of which are incorporated herein by reference. Illustrative cube corner laminates are described in U.S. Patent Nos. 3,648,348; 4,801,193; 4,895,428 and 4,938,563, all of which are incorporated herein by reference. In addition to radiation curable inks, the invention provides a durable, radiation curable coating composition. This composition includes an aliphatic macromonomer, one or more reactive acrylate monomers, photoinitiators and additives, as described above for the inks, but a pigment is not included. The coating composition is prepared in a manner similar to that of the inks, with the exception of the step of forming the compound with pigment. The radiation curable coating composition can be used alone to provide gloss, solvent resistance, cleanability, durability and weathering resistance for any selected substrate, or it can be used as a top coat for the inks of the invention . The combination of a radiation curable ink of the invention and the coating composition of the invention allows the incorporation of color in articles and at the same time provides excellent cleaning capabilities, durability and resistance to outdoor decomposition.

The inks and coatings of the invention are further described in the following examples. It is understood that these examples are only illustrative and not limiting of the invention. Examples are coatings and ink formulations which can be prepared using any of the methods described in the foregoing. Example 8 is prepared using a pigment dispersion of solid chips.

The emplos The following abbreviations are used in the examples: HDDA - hexanediol diacrylate; THFFA - tetrahydrofurfuryl acrylate; IBOA - isobornyl acrylate EEEA - ethoxyethoxyethyl acrylate; NPGPDA - neopentyl glycol diacrylate; (PO) NPGPDA - propoxylated neopentyl glycol diacrylate TMPTA - trimethylolpropane triacrylate PEA - phenoxyethyl acrylate; IRGACURE 1700 - mixture of bis (2,6-dimethylbenzoyl) -2,43-trimethylpentylphosphine oxide and 2-hydroxy-2-methyl-1-phenyl-1-propanone oxide initiator. DC163 - polydimethylsiloxane; Modaflow - acrylic copolymer flow additive Example 1 Ingredient% by weight Toagosei acrylic macromer AA-10 23.0 HDDA 30.0 THFFA 20.0 Blue phthalo pigment 6.2 NPGPDA 16.7 Modaflow 0.9 IRGACURE 1700 3.2 Example 2 Ingredient% by weight Pigment black 20% PB7 in 20 EEA / (PO) PGDA ethoxyethoxyethyl acrylate 50/50 mixture of macromonomer 58 Toagosei AA-6 in HDDA THFFA 14 HDDA 1 IRGACURE 1700 5 DC163 2 Example 3 Ingredient% by weight Pigment black PB7 20% in 20 (PO) NPGDA Mix 50/50 of macromonomer 58 AA-6 in HDDA THFFA 14 HDDA 1 IRGACURE 1700 5 DC163 2 Example 4 Ingredient% by weight Pigment black PB7 20% in 19 EEEA / (PO) NPGDA AA-6 / HDDA (50/50) 16 AA-6 / THFFA (50/50) 42 HDDA 16 IRGACURE 1700 5 DC163 2 Example 5 Ingredient% by weight Pigment black PB7 20% in 20.5 (PO) NPGDA AA-6 / HDDA (50/50) 27 AA-6 / THFFA (50/50) 30 HDDA 9 THFFA 7 IRGACURE 1700 5 Modaflow 1.5 Example 6 Ingredient% by weight HDDA 38.1 THFFA 21.4 Toagosei AA-6 28.8 Acrylic resin Acryloid B-67 - a 3.2 polymer of non-reactive isobutyl methacrylate from Rohm 5. Haas Photoinitiator 3.0 Silicone flow agent 1.5 Stabilizer of hindered amine light 2.0 Phenolic antioxidant 2.0 Example 7 Ingredient% by weight HDDA 35.0 THFFA 12.5 IBOA 12.0 Toagosei AA-6 30.0 Acryloid Acrylic Resin B-67 - a polymer 6.0 of non-reactive isobutyl methacrylate from Rohm & Haas Photoinitiator 3.0 Silicone Flow Agent 1.5 Example 8 Ingredient% by weight HDDA 30.0 THFFA 30.0 Dispersion of pigment microplates 14.0 red 179 / AA-6 50% Macromonomer Toagosei AA-6 19.5 Photoinitiator 5.0 Silicone flow agent 1.5 It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is the conventional one for the manufacture of the objects or products to which it refers.

Claims (26)

CLAIMS Having described the invention as above, the content of the following claims is claimed as property:

1. A radiation curable ink, characterized in that it comprises: (a) an aliphatic functional (meth) acrylate macromonomer; (b) a reactive acrylate monomer; (c) an effective amount of a colorant; and (d) an effective amount of a photoinitiator.

2. The ink according to claim 1, characterized in that the aliphatic acrylate functional macromonomer comprises a macromonomer of methyl methacrylate.

The ink according to claim 1, characterized in that the aliphatic acrylate functional macromonomer has a methacryloyl end group.

The ink according to claim 1, characterized in that the aliphatic acrylate functional macromonomer comprises Macromonomer AA-6, Macromonomer AA-10, or a mixture thereof.

5. The ink according to claim 1, characterized in that the reactive acrylate monomer comprises a mixture of mono- and di-acrylates.

The ink according to claim 5, characterized in that the ratio of diacrylate: monoacrylate is from about 2: 1 to 0.85: 1.

The ink according to claim 1, characterized in that the reactive acrylate monomer comprises tetrahydrofurfuryl acrylate, isobornyl acrylate, hexanediol diacrylate, ethoxyethoxyethyl acrylate, propoxymethylene glycol diacrylate, trimethylolpropane triacrylate or a mixture thereof.

8. The ink according to claim 1, characterized in that the photoinitiator comprises a bisacetophosphine oxide combined with an alpha-hydroxyacetophenone.

9. A radiation curable ink, characterized in that it comprises: (a) about 10 to about 40% by weight of an aliphatic acrylate functional macromonomer; (b) about 40 to 60% by weight of a reactive acrylate monomer; (c) about 1 to 15% by weight of a colorant; Y (d) about 2 to 6% by weight of a photoinitiator.

10. The ink according to claim 9, characterized in that the aliphatic acrylate functional macromonomer comprises a macromonomer of methyl methacrylate.

The ink according to claim 9, characterized in that the aliphatic acrylate functional macromonomer comprises Macromonomer AA-6, Macromonomer AA-10, or a mixture thereof.

The ink according to claim 9, characterized in that the reactive acrylate monomer comprises a mixture of mono- and di-acrylates.

The ink according to claim 12, characterized in that the ratio of diacrylate: monoacrylate is from about 2: 1 to 0.85: 1.

14. The ink according to claim 9, characterized in that the reactive acrylate monomer comprises tetrahydrofurfuryl acrylate, hexanediol diacrylate, oxy or ethoxyethyl acrylate, propoxymethylene glycol diacrylate, propoxytrimethylolpropane triacrylate, or a mixture thereof. same.

15. The ink according to claim 9, characterized in that the photoinitiator comprises a phosphine oxide, an alpha rupture type photoinitiator or a hydrogen abstraction type.

16. A radiation curable composition, characterized in that it comprises: (a) an aliphatic acrylate functional macromonomer; (b) a reactive acrylate monomer; and (c) an effective amount of a photoinitiator.

17. The coating according to claim 16, characterized in that the aliphatic acrylate functional monomer comprises a macromonomer of methyl methacrylate.

18. The coating according to claim 16, characterized in that the aliphatic acrylate functional macromonomer comprises Macromonomer AA-6, Macromonomer AA-10, or a mixture thereof.

19. The coating in accordance with claim 16, characterized in that the reactive acrylate monomer comprises a mixture of mono- and di-acrylates.

The coating according to claim 16, characterized in that the ratio of diacrylate: monoacrylate is from about 2: 1 to 0.85: 1.

The coating according to claim 16, characterized in that the reactive acrylate monomer comprises tetrahydrofurfuryl acrylate, hexanediol diacrylate, ethoxyethoxyethyl acrylate, propoxymethylene glycol diacrylate, isobornyl acrylate, propoxytrimethylolpropane triacrylate, or a mixture thereof.

22. The coating according to claim 16, characterized in that the photoinitiator comprises a phosphine oxide combined with an alpha-hydroxyketone.

The coating according to claim 16, characterized in that it comprises: (a) about 10 to about 40% by weight of an aliphatic acrylate functional macromonomer; (b) about 30 to 70% by weight of a reactive acrylate monomer; and (c) about 1 to 6% by weight of a photoinitiator.

24. A retroreflective laminate, comprising a retroreflective layer and on the layer, an image formed of radiation curable ink, the ink is characterized in that it comprises: (a) an aliphatic functional (meth) acrylate macromonomer; (b) a reactive acrylate monomer; (c) an effective amount of a colorant; and (d) an effective amount of a photoinitiator.

25. The laminate according to claim 24, characterized in that it further comprises a radiation curable topcoat, the topcoat comprises: (a) an aliphatic acrylate functional macromonomer; (b) a reactive acrylate monomer; and (c) an effective amount of a photoinitiator.

26. An indicator article, characterized in that it comprises the retroreflective laminate according to claim 24 adhered to a substrate.