EP1989050A1

EP1989050A1 - Use of coloured polymer systems for packaging

Info

Publication number: EP1989050A1
Application number: EP07704590A
Authority: EP
Inventors: Wendel Wohlleben; Reinhold J Leyrer
Original assignee: BASF SE
Current assignee: BASF SE
Priority date: 2006-02-21
Filing date: 2007-02-15
Publication date: 2008-11-12
Also published as: WO2007096291A1; US20090098368A1; CN101389474A; JP2009527610A

Abstract

Carrier coated with a polymer system, characterized in that the polymer system reflects electromagnetic radiation (Bragg reflection), the wavelength of the reflection can be changed when there is an elongation produced by a mechanical stress and the coated carrier is altogether so inelastic that, when the mechanical stress no longer occurs, the wavelength of the Bragg reflection is changed in comparison with the initial state.

Description

Use of colored polymer systems for packaging

description

The invention relates to a carrier coated with a polymer system, characterized in that

the polymer system reflects electromagnetic radiation (Bragg reflection), the wavelength of the reflection at a strain generated by a mechanical stress is variable and the coated carrier is so little elastic overall that when the mechanical stress is removed, the wavelength of the Bragg reflection with respect to the Initial state is changed.

Aqueous polymer dispersions are inexpensive, easily produced organic materials. It was known from DE-A 197 17 879 and DE-A 198 20 302 that special polymer dispersions are suitable for the preparation of polymer systems from polymer particles and matrix and these polymer systems exhibit a Bragg reflection. Embodiments of these polymer dispersions or their use can also be found in DE-A 103 21 083, DE-A 103 21 079, DE-A 103 21 084 or in the German patent applications with the file reference 10 not yet published on the date of filing this application 2005 023 804.1, 10 2005 023 806.8, 10 2005 023 802.5 and 10 2005 023 807.6.

The use of such polymer systems for the production of optical display elements (display) is described in DE-A 102 29 732. In the display elements, color changes are caused by the change in the distances between the polymer particles dispersed in the matrix. Cause of the distance changes can z. B. be the action of mechanical forces or electric fields.

Object of the present invention were other uses of the polymer systems.

Accordingly, the coated supports defined above were found. Also found were uses of the carriers for packaging.

The polymer system is a system of polymer particles and a deformable material (matrix), the polymer particles being distributed in the matrix according to a defined space lattice structure. To the polymer particles

To form a defined space lattice structure, the discrete polymer particles should be as equal as possible. A measure of the uniformity of the polymer particles is the so-called polydispersity index, calculated according to the formula

P.I. = (D90-D10) / D50

wherein D90, D10 and D50 denote particle diameters for which:

D90: 90% by weight of the total mass of all particles has a particle diameter less than or equal to D90

D50: 50% by weight of the total mass of all particles has a particle diameter less than or equal to D 50 D10: 10% by weight of the total mass of all particles has a particle diameter less than or equal to D 10

Further explanations of the polydispersity index can be found e.g. in DE-A 197 17 879 (in particular drawings page 1).

The particle size distribution can be determined in a manner known per se, e.g. with an analytical ultracentrifuge (W. Mächtle, Macromolecular Chemistry 185 (1984) page 1025-1039) are determined and taken from the D 10, D 50 and D 90 value and the polydispersity index can be determined.

The polymer particles preferably have a D 50 value in the range of 0.05 to 5 mm. The polymer particles may be one type of particle or several particle types with different D 50 value, each particle type having a polydispersity index preferably less than 0.6, particularly preferably less than 0.4 and very particularly preferably less than 0.3 and in particular less than 0, 15 has.

In particular, the polymer particles now consist of a single particle type. The D 50 value is then preferably between 0.05 and 2 μm, more preferably between 100 and 400 nanometers. However, there are also wavelengths from 50 to 1 100 nanometers into consideration.

Also, polymer particles which, for example, consist of 2 or 3, preferably 2, different particle types with respect to the D 50 value can form (crystallize) a common lattice structure if the above condition with respect to the polydispersity index is satisfied for each particle type. Suitable examples are mixtures in particle types with a D 50 value of 0.3 to 1, 1 micron and with a D 50 value of 0.1 up to 0.3 μm.

The polymer particles are preferably made of a polymer having a glass transition temperature greater than 30 C, more preferably greater than 50 C and most preferably greater than 70 ° C, in particular greater than 90 ° C.

The glass transition temperature can be determined by conventional methods such as differential thermal analysis or differential scanning calorimetry (see, for example, ASTM 3418/82, so-called "mid-point temperature").

The polymer is preferably at least 40 wt .-%, preferably at least 60 wt .-%, more preferably at least 80 wt .-% of so-called main monomers.

The main monomers are selected from C1-C20 alkyl (meth) acrylates, vinyl esters of carboxylic acids containing up to 20 carbon atoms, vinyl aromatics having up to 20 carbon atoms, ethylenically unsaturated nitriles, vinyl halides, vinyl ethers having from 1 to 10 carbon atoms Alcohols, aliphatic hydrocarbons having 2 to 8 carbon atoms and 1 or 2 double bonds or mixtures of these monomers.

To name a few are z. B. (meth) acrylic acid alkyl ester having a C 1 -C 10 alkyl radical, such as methyl methacrylate, methyl acrylate, n-butyl acrylate, ethyl acrylate and 2-ethylhexyl acrylate.

In particular, mixtures of (meth) acrylic acid alkyl esters are also suitable.

Vinyl esters of carboxylic acids having 1 to 20 carbon atoms are e.g. Vinyl laurate, stearate, vinyl propionate, vinyl versatate and vinyl acetate.

Suitable vinylaromatic compounds are vinyltoluene, α- and p-methylstyrene, α-butylstyrene, 4-n-butylstyrene, 4-n-decylstyrene and preferably styrene. Examples of nitriles are acrylonitrile and methacrylonitrile.

The vinyl halides are chloro, fluoro or bromo substituted ethylenically unsaturated compounds, preferably vinyl chloride and vinylidene chloride.

To name as vinyl ethers are, for. Vinyl methyl ether or vinyl isobutyl ether. Vinyl ether is preferably from 1 to 4 C-containing alcohols.

Suitable hydrocarbons having 2 to 8 carbon atoms and one or two olefinic double bonds are butadiene, isoprene and chloroprene, with one double bond, for example ethylene or propylene. Preferred main monomers are the C 1 - to C 20 -alkyl acrylates and -methacrylates, in particular C 1 - to C 8 -alkyl acrylates and -methacrylates, vinylaromatics, in particular styrene, and mixtures thereof, in particular also mixtures of alkyl (meth) acrylates and vinylaromatics.

Very particular preference is given to methyl acrylate, methyl methacrylate, ethyl acrylate, n-butyl acrylate, n-hexyl acrylate, octyl acrylate and 2-ethylhexyl acrylate, styrene and mixtures of these monomers.

The polymer particles are preferably chemically crosslinked. For this purpose, monomers having at least two polymerisable groups, e.g. Divinylbenzene or allyl methacrylate, also used (internal crosslinking). However, it is also possible to add crosslinkers (external crosslinking).

To the matrix

There should be a difference in refractive index between the matrix and the polymers.

Preferably, the difference should be at least 0.01, more preferably at least 0.1.

Both the matrix and the polymer can have the higher refractive index. The key is that there is a difference.

The matrix consists of a deformable material. Deformability is understood to mean that the matrix allows a spatial displacement of the discrete polymer particles upon application of external forces (eg, mechanical, electromagnetic).

Preferably, therefore, the matrix consists of an organic material, or organic compounds having a melting point or a glass transition temperature below 20 ° C, more preferably below 10 ° C, most preferably below 0 ⁰ C (at 1 bar).

Also contemplated are organic compounds having a melting point or glass transition temperature (Tg) above 20 ° C but intermediate heating above the melting point or Tg is required if the polymer particle spacings are to be changed (see below).

In consideration are liquids such as water or higher viscous liquids such as glycerol or glycol. Preference is given to polymeric compounds, for example polycondensates, polyadducts or polymers obtainable by free-radical polymerization.

Called e.g. Polyesters, polyamides, formaldehyde resins, such as melamine, urea or phenol-formaldehyde condensates, polyepoxides, polyurethanes, or else the above-mentioned polymers containing the main monomers listed, for. Polyacrylates, polybutadienes, styrene / butadiene copolymers.

For the production

Production methods are described in DE-A 197 17 879 and DE-A 198 20 302.

Preparation of discrete polymer particles.

The preparation of the polymer particles or polymers is carried out in a preferred embodiment by emulsion polymerization, it is therefore an emulsion polymer.

The emulsion polymerization is particularly preferred because of the availability of polymer particles having a uniform spherical shape.

However, the production can z. B. also be carried out by solution polymerization and subsequent dispersion in water.

In the emulsion polymerization, ionic and / or nonionic emulsifiers and / or protective colloids or stabilizers are used as surface-active compounds.

A detailed description of suitable protective colloids can be found in Houben-Weyl, Methods of Organic Chemistry, Volume XIV / 1, Macromolecular Substances, Georgian Chem.

Thieme-Verlag, Stuttgart, 1961, p. 41 1 to 420. Suitable emulsifiers are both anionic, cationic and nonionic emulsifiers. Emulsifiers whose molecular weight, unlike the protective colloids, are usually below 2000 g / mol, are preferably used as surface-active substances.

The surfactant is usually used in amounts of from 0.1 to 10% by weight, based on the monomers to be polymerized.

Water-soluble initiators for the emulsion polymerization are z. For example, ammonium and alkali metal salts of peroxodisulfuric, z. For example, sodium peroxodisulfate, hydrogen peroxide or organic peroxides, z. B. tert-butyl hydroperoxide. Also suitable are so-called reduction-oxidation (red-ox) -lititiator systems.

The redox initiator systems consist of at least one mostly inorganic reducing agent and one inorganic or organic oxidizing agent.

The oxidation component is z. B. to the above-mentioned initiators for emulsion polymerization.

The reduction components are, for. For example, alkali metal salts of sulphurous acid, e.g. Sodium sulfite, sodium hydrogen sulfite, alkali metal salts of disulfurous acid such as sodium disulfite, bisulfite addition compounds of aliphatic aldehydes and ketones such as acetone bisulfite or reducing agents such as hydroxymethanesulfinic acid and its salts, or ascorbic acid. The redox initiator systems can be used with the concomitant use of soluble metal compounds whose metallic component can occur in several valence states.

Usual Red Ox initiator systems are z. As ascorbic acid / iron (II) sulfate / sodium peroxydisulfate, tert-butyl hydroperoxide / sodium disulfite, tert-butyl hydroperoxide / Na hydroxymethanesulfinic. The individual components, eg. As the reduction component, may also be mixtures z. B. a mixture of the sodium salt of hydroxymethanesulfinic acid and sodium disulfite.

The amount of initiators is generally 0.1 to 10 wt .-%, preferably 0.5 to 5 wt .-%, based on the monomers to be polymerized. It is also possible to use a plurality of different initiators in the emulsion polymerization.

The emulsion polymerization is generally carried out at 30 to 130, preferably 50 to 90 ° C. The polymerization medium may consist of water only, as well as of mixtures of water and thus miscible liquids such as methanol. Preferably, only water is used. The emulsion polymerization can be carried out both as a batch process and in the form of a feed process, including a stepwise or gradient procedure. Preferably, the feed process in which one submits a portion of the polymerization, heated to the polymerization, polymerized and then the rest of the polymerization, usually over several spatially separate feeds, one or more of which monomers in pure or in emulsified form, continuously , gradually or with the addition of a concentration gradient while maintaining the polymerization of the polymerization zone supplies. In the polymerization can also z. B. be presented for better adjustment of the particle size of a polymer seed.

The manner in which the initiator is added to the polymerization vessel in the course of the free-radical aqueous emulsion polymerization is the average professional. It can be introduced both completely into the polymerization vessel, or used continuously or in stages according to its consumption in the course of the free radical aqueous emulsion polymerization. In particular, this depends on the chemical nature of the initiator system as well as on the polymerization temperature. Preferably, a part is initially charged and the remainder supplied according to the consumption of the polymerization.

A uniform particle size distribution, i. a low polydispersity index is obtainable by means known to the person skilled in the art, e.g. Example by varying the amount of surface-active compound (emulsifier or protective colloids) and / or corresponding stirrer speeds.

To remove the residual monomers is usually also after the end of the actual emulsion polymerization, i. after a conversion of the monomers of at least 95%, initiator added.

The individual components can be added to the reactor in the feed process from above, in the side or from below through the reactor bottom.

In the emulsion polymerization, aqueous dispersions of the polymer are generally obtained with solids contents of 15 to 75 wt .-%, preferably from 40 to 75 wt .-%.

Preparation of the mixture of polymer particles / matrix (layer)

Water or solvent as matrix

In the emulsion polymerization, an aqueous dispersion of the polymer particles is obtained directly. The water can simply be removed until the lattice structure of the polymer particles, recognizable by the color effects to be observed, is established.

If other solvents are desired, water can be easily exchanged for these solvents.

Polymeric compounds as a matrix

The aqueous dispersion of discrete polymer particles obtained in the emulsion polymerization may be mixed with the amount of the polymeric compound required to adjust the lattice structure and then the water removed. Due to the often high viscosity of the polymeric compound, it may be advantageous to first polymer particles with the structural components of the polymeric compound to mix and then, after the dispersion of the polymer, these structural components z. B. by condensation, adduct formation to the polymeric compounds implement.

But it is also possible to use thermoplastic polymers as a matrix. Polymer particles and thermoplastic are mixed and heated by heat and shear, e.g. B. in the extruder, forced to crystallize. To adjust the melt properties, the polymer can be extruded and also mixed with commercially customary processing aids.

Emulsion polymers as discrete polymer particles and emulsion polymers as matrix

Preference is given to emulsion polymers as discrete polymer particles and emulsion polymers as matrix

The corresponding emulsion polymers can simply be mixed and then the water removed. Insofar as the emulsion polymers for the matrix have a glass transition temperature below 20.degree. C. (see above), the polymer particles film at room temperature and form the continuous matrix; at higher Tg, heating to temperatures above the Tg is required.

It is particularly simple and advantageous to prepare both emulsion polymers in one step as a core / shell polymer. For this, the emulsion polymerization is carried out in two stages. First, the monomers are polymerized, which form the core (= later discrete polymer particles), then the monomers are polymerized in a second stage in the presence of the core, which form the shell (= later matrix).

In the event of subsequent removal of the water, the soft shell, whose glass transition temperature is below 20 ° C., films and the remaining (hard) cores are distributed as discrete polymer particles in the matrix.

The polymer particles are therefore particularly preferably the core of core / shell polymers, and the matrix is formed by filming the shell.

Core / shell polymers obtainable by emulsion polymerization are particularly preferred in the context of the present invention.

Particularly suitable embodiments of the core / shell emulsion polymers can be found in DE-A 197 17 879, DE-A 198 20 302, DE-A 103 21 083, DE-A 103 21 079, DE-A 103 21 084 or in the German patent applications not yet published on the date of filing this application with the file references 10 2005 023 804.1, 10 2005 023 806.8, 10 2005 023 802.5 and 10 2005 023 807.6.

The weight ratio of core to shell is preferably 0.05 to 1 to 20 to 1, particularly preferably 0.1 to 1 to 1 to 1.

The polymeric compounds can also be crosslinked to have elastic properties. As far as crosslinking is desired, it is preferably carried out during or after the filming, for example by thermally or photochemically initiated crosslinking reaction of a crosslinker which is added or may already be bound to the polymer.

The crosslinking of the matrix causes a restoring force which acts on the discrete polymer particles. Without the action of external forces, the polymer particles then return to the predetermined starting position.

For the construction of the polymer system of polymer particles and matrix

The polymer system causes an optical effect, that is, a reflection to be observed by interference of the light scattered on the polymer particles.

The wavelength of the reflection can be depending on the distance of the polymer particles in the entire electromagnetic spectrum. The wavelength is preferably in the UV range, IR range and in particular in the range of visible light.

The wavelength of the reflection to be observed depends, according to the known Bragg equation, on the interplanar spacing, here the distance between the polymer particles arranged in a space lattice structure in the matrix.

In order to set the desired space lattice structure with the desired distance between the polymer particles, in particular the weight proportion of the matrix is to be selected accordingly. In the preparation methods described above, the organic compounds, for. B. polymeric compounds are used in an appropriate amount.

In particular, the proportion by weight of the matrix is dimensioned such that a space lattice structure of the polymer particles is formed, which reflects electromagnetic radiation in the desired range. The distance between the polymer particles (each to the center of the particles) is suitably 50 to 1100 nanometers, preferably 100 to 400 nm, if a color effect, ie a reflection in the range of visible light, is desired.

To the coated carrier

The carrier may be made of any material. In consideration come z. As carriers of paper or plastic films, in particular, it may also be the carrier to a multi-layer laminate whose individual layers consist of different materials.

Eπ eä'iv i? x «ei! θ! Ϊ! ' ^x , s HV ^; -.Üi>"h>s> O Pss Ki ¹ ^Λ t:... N". Λ> s ^"* V ^x iV reren mm, for example up to 5 mm or more.

It is essential that the coated carrier as a whole is so little elastic that when the mechanical stress is removed, the wavelength of the Bragg reflection remains changed relative to the initial state.

This can be z. B. be achieved in that the matrix material is chosen so that the restoring forces are low. This can z. B. be achieved by concomitant use of regulators in the polymerization of the shell of core / shell particles, the regulator amount is preferably less than 10, more preferably less than 2 wt. Parts to 100 wt. Parts of monomers. In particular, this can also be achieved by using only little or no crosslinking monomers or other crosslinkers in the matrix or in the shell of the core / shell particles.

This can also be achieved by making the carrier less elastic than the polymer system; Naturally, the coated polymer system can only go as far back to its original state when adhering to the carrier material as the carrier material itself

Is z. As the Bragg reflection in the visible wavelength range, the color is changed after elimination of the mechanical stress to the original color.

A security feature designed in this way, for example a label applied as closure on a packaging, is characterized by a specific color which can be adjusted by the polymer system according to the invention. If this security feature is stretched, for example, by opening the packaging, a irreversible change of the color of the label. This can be checked in a simple manner, whether the package has been opened or not.

If the wavelength of the Bragg reflection lies in the visible range, then a color change is to be established compared to the initial state.

At wavelengths in the non-visible range, z. B. IR or UV range, then a wavelength change can be easily determined by suitable detectors.

The coated supports are suitable for. As labels, stickers, tape, adhesive film and can be glued to any substrates.

In particular, the coated carriers can be used as or in packages. They can be glued as labels, stickers, adhesive tapes or adhesive films on any substrates at a suitable location; but the packages themselves may also consist entirely or partially of the coated carriers.

The non-reversible change in Bragg reflection wavelength ultimately protects against imitation or removal of indicia attached to packaging such as trademarks, logos, product descriptions, etc.

When opening packages or removing packaging components, there will be strains at the points in question. When the coated carrier is appropriately attached or integrated into the package, the coated carrier also expands.

The coated carriers can also be used as counterfeit-proof markers. Such markers may, for. For example, banknotes, checks, credit cards, ID cards, stamps, lottery tickets, train tickets, entrance tickets, pharmaceutical packaging, other packaging, software, electronic products, markings, logos, items of all kinds.

Since the wavelength of the Bragg reflection is no longer or at least not completely reversible, the wavelength of the Bragg reflection changes permanently. By simply detecting a color change or by using appropriate detectors (if the wavelength is in the IR or UV range), it can be determined if packages have been opened or tags removed or attempts have been made to make changes to tags. Examples

Preparation of the polymers

The following embodiments illustrate the invention. The emulsifiers used in the examples have the following compositions:

Emulsifier 1: 30 wt .-% solution of the sodium salt of an ethoxylated and sulfated nonylphenol with about 25 mol / mol ethylene oxide units.

Emulsifier 2:40% by weight solution of a sodium salt of a C12 / C14 paraffin sulfonate.

Emulsifier 3:15% by weight solution of linear sodium dodecylbenzenesulfonate.

The particle size distributions were determined by means of an analytical ultracentrifuge or by means of the capillary hydrodynamic fractionation method (CHDF 1100 particle size analyzer from Matec Applied Sciences) and from the values obtained the P.I. value according to the formula given here

P. L. = (D90 - D10) / D50

calculated. Unless otherwise stated, solutions are aqueous solutions.

The term pphm used in the examples means parts by weight based on 100 parts by weight of total monomers.

The abbreviations used for monomers have the following meanings: AS = acrylic acid, n-BA = n-butyl acrylate, DVB = divinylbenzene, EA = ethyl acrylate, MAS = methacrylic acid, MAMoI = N-methylolmethacrylamide, NaPS = sodium persulfate.

Example 1: Preparation of an Emulsion Polymer

In a glass reactor provided with anchor stirrer, thermometer, gas inlet tube, dropping funnel and reflux condenser, a dispersion of 0.9 g (0.20 pphm) of polystyrene seed (particle size: 30 nm) in 500 ml of water is introduced and heated with stirring in a heating bath, at the same time the air is displaced by the introduction of nitrogen. When the heating bath has reached the preset temperature of 85 ° C. and the reactor contents have reached the temperature of 80 ° C., the introduction of nitrogen is interrupted and, at the same time, an emulsion of 445.5 g of styrene (99.0% by weight) is added over the course of 3 hours. , 4.5 g of divinylbenzene (1.0 wt .-%) and 14.5 g of emulsifier 1 (1, 0 pphm) in 501, 3 ml of water and 54.0 g of a 2.5 wt% aqueous solution of sodium persulfate (0.3 pphm). After complete addition of the solutions, the polymerization is continued for 7 hours at 85 ° C and then cooled to room temperature.

The dispersion has the following properties:

Solids content: 29.6% by weight

Particle size: 255 nm

Coagulum content: <i g pH value: 2.3

Polydispersity index: 0.13

Refractive index: 1, 59

This example was repeated several times, varying the concentration of seed particles. The following Table I gives an overview of the test results obtained.

table

Example 2: Preparation of an emulsion polymer with core / shell structure.

In a glass reactor provided with anchor stirrer, thermometer, gas inlet tube, dropping funnel and reflux condenser, 300 g of the dispersion of core particles obtained in Example 1 A are initially charged and heated with stirring in a heating bath, at the same time displacing the air by introducing nitrogen.

When the heating bath has reached the preset temperature of 85 ° C and the reactor contents have reached the temperature of 80 ° C, the introduction of nitrogen is interrupted and it takes place simultaneously over the course of 1.5 hours. a) a mixture of 85.1 g (98.5% by weight) of n-butyl acrylate, 0.86 (1.0% by weight) of acrylic acid, 0.43 g (0.5% by weight) t-Dodecylmerkaptan, 2.86 g of a 31 wt .-% solution (0.97 pphm) of the emulsifier I and 12.4 g of water and

b) 17.3 g of a 2.5 wt .-% aqueous solution of sodium persulfate (0.5 pphm) was added dropwise.

After complete addition of the solutions, the polymerization is continued for 3 hours at 85 C. Thereafter, the resulting dispersion of core / shell particles is cooled to room temperature.

The dispersion has the following properties:

Solids content: 40.6% by weight Particle size: 307 nm Polydispersity index (PI): 0.16 Weight ratio Keπr shell: 1: 1 (calculated) Refractive index of the shell polymer. 1, 44

This example was repeated twice more, varying the concentration of core particles and the weight ratio of core / shell. The following Table 2 gives an overview of the test results obtained.

Table 2

Wt% for nBA, t-dodecylmercaptan and AS are based on the shell.

Production of a reflective layer Example 3A

15 g of the dispersion obtained according to Example 2A are dried in a silicone rubber dish at room temperature. This gives a bright effect colored layer of rubbery elasticity. A transparent film is obtained which has a luminous color which varies in illumination and viewing angle, the more the darkening of the background is seen, the more the intensity of travel becomes. As the layer is stretched, its color changes irreversibly with the red brown elongation ratio from green to violet to the ultraviolet.

Example 3 B and 3C

The procedure is as in Example 3 A with the difference that instead of the dispersion of Example 2 A, the dispersion of 2 B or 2 C is used. A transparent film is obtained which has a luminous color which varies with the illumination and viewing angle, the driving intensity becoming more visible the darker the background. When stretching the layer thus obtained, its color changes irreversibly from a red in Example 3 B, or a dark red in Example 3 C over green to violet to the ultraviolet.

Claims

claims

1. carrier coated with a polymer system, characterized in that

the polymer system reflects electromagnetic radiation (Bragg

Reflection), the wavelength of reflection at a strain generated by a mechanical stress is variable and the coated carrier is so little elastic overall that when the mechanical stress is removed, the wavelength of the Bragg reflection is changed from the initial state.

2. Coated carrier according to claim 1, characterized in that the polymer system is a system of polymer particles and a deformable material (matrix), the polymer particles being distributed in the matrix according to a defined space lattice structure.

3. Coated carrier according to claim 1 or 2, characterized in that the polymer particles are one or more particle types with an average particle diameter in the range of 0.05 to 5 μm, each

Particle has a polydispersity index (PI) less than 0.6, calculated according to the formula

P. L. = (D90-D10) / D50

wherein D90, D10 and D50 denote particle diameters for which:

D 90: 90% by weight of the total mass of all particles has a particle diameter less than or equal to D 90 D 50: 50% by weight of the total mass of all particles has a particle diameter less than or equal to D 50

D 10: 10% by weight of the total mass of all particles has a particle diameter less than or equal to D 10

4. Coated carrier according to one of claims 1 to 3, characterized in that the discrete polymer particles have a glass transition temperature greater than 30 ° C.

5. Coated carrier according to one of claims 1 to 4, characterized in that the polymer particles and the matrix differ in the refractive index.

6. Coated carrier according to one of claims 1 to 5, characterized in that the matrix consists of a polymeric compound.

7. Coated carrier according to one of claims 1 to 6, characterized in that the polymer particles are the core / core core

Polymer is and the matrix is formed by filming the shell.

8. Coated carrier according to one of claims 1 to 7, characterized in that the distance between the polymer particles 50 to 1 100 nanometers ter, so that electromagnetic radiation in the range of ultraviolet to near-infrared light is reflected.

9. Coated carrier according to one of claims 1 to 7, characterized in that the distance between the polymer particles is 100 to 400 nanometers, so that electromagnetic radiation in the visible

Light is reflected.

10. Coated carrier according to one of claims 1 to 9, characterized in that the thickness of the layer is 1 micron to 150 microns.

1 1. A coated carrier according to any one of claims 1 to 10, characterized in that the carrier is selected from paper, cardboard, plastic films or metal foils

12. Use of coated carriers according to one of claims 1 to 1 1 as labels, stickers, adhesive tape, adhesive film

13. The use of coated carriers according to any one of claims 1 to 1 1 as or in packaging

14. Use of coated carriers according to one of claims 1 to 11 as protection against imitation or removal of labels affixed to packaging, such as brands, logos, product descriptions, bar codes, etc

15. The use of coated carriers according to any one of claims 1 to 1 1 for checking whether packages have already been used or opened.

16. Use of coated carriers according to one of claims 1 to 1 1 as tamper-proof markings

17. The use of coated carriers according to one of claims 1 to 1 1 as tamper-proof markings on banknotes, checks, credit cards, ID Cards, stamps, lottery tickets, tickets, entrance tickets, pharma- ceutical packaging, other packaging, software, electronic goods, identification of brands, logos, all kinds of goods.