Multilayer effect pigments containing biodegradable polymers

Abstract

The present invention relates to effect pigments and multilayer films comprising two or more alternating biodegradable polymer layers with different refractive indices, methods for their preparation, and their use, especially in cosmetics, rinse-off products, packaging materials, decorative films, paints, printing inks, and plastic products.

Description

[Technical Field]

[0001] The present invention relates to effect pigments and multilayer films having a structure in which two or more alternating biodegradable polymer layers with different refractive indices are arranged, to a method for their preparation and to their use, especially in cosmetics, rinse-off products, packaging materials, decorative films, paints, printing inks and plastics. [Background technology]

[0002] Traditional decorative or effect films are often constructed from uniaxially or biaxially oriented polyester films, consisting of alternating polymer layers, such as PET (polyethylene terephthalate) and PBT (polybutylene terephthalate). Orienting multilayer films creates angle-dependent color effects due to different degrees of orientation and, therefore, different degrees of refraction in the alternating polymer layers. Adding additional colorants, such as solvent dyes, to the film allows for custom color settings. A barrier effect combined with a reflective effect can be achieved, if desired, by applying an additional metal layer, usually aluminum. Films of this type are used as packaging materials for gifts, flowers, food, etc. Glitter particles, used in cosmetics, rinse-off products such as shower gels, or toys, can be obtained from such films by methods such as grinding, cutting, or punching. The alignment of polymer chains that occurs during the stretching process requires the use of polyesters containing aromatic dicarboxylic acids, particularly terephthalic acid, as monomer components. However, these materials are not biodegradable and are not currently available in an economically viable manner from renewable raw materials.

[0003] The object of the present invention is therefore to produce biodegradable effect pigments and multilayer films in a wide range of colours from renewable raw materials (i.e. composed of a proportion of bio-based raw materials greater than 50%), made of biodegradable polymers, but which do not contribute to the further increase of microplastics in the environment, preferably without the need for metallic or inorganic layers, in a simple and inexpensive process from commercially available starting materials. This objective has been achieved by the present invention based on the effect pigments and multilayer films described and claimed in this application. In particular, it has surprisingly been found that this objective can be achieved by obtaining pigments from multilayer films containing only two polymers with different refractive indices, which are commercially available, preferably obtained from natural sources, and are biodegradable, with multiple, for example, 64 to 256 optically active individual layers alternating with one another. The polymer layers can be extruded simultaneously, cut, and laminated without subsequent stretching, exhibit excellent adhesion even without additional auxiliaries, and exhibit metallic-appearing color effects produced by interference, depending on the layer thickness and refractive index. These multilayer films can be comminuted into particles of suitable size, for example by grinding, cutting, or punching, and can then be used as effect pigments. Furthermore, it has surprisingly been found that the material combination of two commercially available biodegradable polymers, polylactic acid (especially D / L copolymer) and PBAT (polybutylene adipate terephthalate), especially as a random copolymer, is particularly suitable for use in the effect pigments and multilayer films according to the invention.

[0004] US Patent No. 6,299,979 describes polymeric color effect pigments that contain multiple layers of thermoplastic organic materials with different refractive indices, but does not mention biodegradable materials.

[0005] U.S. Patent Application Publication No. 2007 / 014977A1 ​​describes an iridescent multilayer film consisting of alternating layers of biodegradable polylactic acid and non-biodegradable polyterephthalate. The film is produced by coextrusion of the two polymers, followed by stretching, preferably to increase the refractive index difference and achieve more vibrant colors. It also states that the film can be crushed to produce glitter particles. However, the polyterephthalate used is not biodegradable and cannot be obtained from renewable raw material sources in an economically viable manner. Furthermore, the additional process step of stretching the film makes the manufacturing process more time-consuming and expensive.

[0006] U.S. Patent Application Publication No. 2013 / 0295355 A1 describes a biodegradable, multilayer, transparent, flexible packaging film composed of at least one first PLA-based polymer layer and a second aliphatic or aliphatic-aromatic copolyester layer, arranged alternately, with the first polymer layer forming the outer layer. The film may optionally include a third polymer layer, composed of an aliphatic or aliphatic-aromatic polyester-based polymer different from the second polymer layer, disposed between the first and second polymer layers. This multilayer film is manufactured by melt-extrusion of each polymer, layering the extrudates, and subsequent stretching. Furthermore, the specification states that the individual layer thicknesses of the polymer layers should be between 133 and 5000 nm. This is because, if the individual layer thickness is less than 133 nm (refractive index n = 1.465), the described transparent film exhibits undesirable interference phenomena in the visible wavelength range, particularly reddish interference at 780 nm. However, the lower limit of the individual layer thickness significantly limits the latitude of parameters available for achieving further color variations. Furthermore, the additional process step of stretching the film means that the manufacturing process becomes more time consuming and expensive. However, the effect pigments and multilayer films according to the present invention, and the advantages achieved thereby, have not been described in the prior art and were not obvious from the prior art. Summary of the Invention

[0007] The present invention therefore relates to an effect pigment comprising, preferably consisting of, two or more transparent layers of a first polymer and two or more transparent layers of a second polymer, the two polymers having different refractive indices, the first and second polymer layers being arranged in an alternating manner, and the two polymers being selected from biodegradable polymers. The present invention further relates to a method for making an effect pigment as described above and below, characterized in that the first and second polymers are respectively co-extruded (preferably at an elevated temperature), superimposed one on top of the other, optionally cut, laminated and forced through a film die into a multilayer film structure (preferably at an elevated temperature), the above steps may be repeated multiple times, the polymer film is preferably not stretched or oriented after extrusion, and the multilayer film thus obtained is otherwise die-cut, ground, cut or crushed into particles, and the particles are optionally sorted by size. The present invention further relates to a multilayer film comprising, preferably consisting of, two or more transparent layers of a first polymer as described above and below and two or more transparent layers of a second polymer, wherein the two polymers have different refractive indices, the layers of the first polymer and the layers of the second polymer are arranged in an alternating manner, the two polymers are selected from biodegradable polymers, and the individual average layer thickness of all polymer layers is 130 nm or less.

[0008] The present invention further relates to a method for producing a multilayer film as described above and below, wherein the first and second polymers are respectively co-extruded (preferably at an elevated temperature), layered one on top of the other, optionally cut, laminated and passed through a film die into a multilayer film structure (preferably at an elevated temperature), the above steps may be repeated multiple times, and the polymer film is preferably not stretched or oriented after extrusion. The present invention further relates to formulations comprising one or more effect pigments according to the invention, in particular for use in products and for the uses described above and below.

[0009] Furthermore, the present invention relates to the use of the effect pigments, multilayer films and formulations according to the invention as described above and below, preferably in products selected from the group consisting of cosmetics, rinse-off products, packaging materials, decorative films, paints, printing inks and plastics. The present invention further relates to products comprising one or more of the above- and below-described effect pigments according to the invention, the formulations according to the invention or the multilayer films according to the invention, in particular products selected from the group consisting of cosmetics, rinse-off products, packaging materials, decorative films, paints, printing inks, plastics. According to the EPA network (European Network of the Heads of Environment Protection Agencies Plastics Interest Group, Working Paper Nov. 2018*), the term "biodegradable polymers / plastics" as used above and below refers to materials that may be convertible by biological activity (enzymatic cleavage and metabolism by bacteria / fungi) into naturally occurring metabolic end products. Ideally, this chemical metabolic process mineralizes the plastic into, for example, oxygen, carbon dioxide or their salts, carbon and methane.

[0010] The effect pigments and multilayer films according to the invention are characterized in particular by angle-dependent color effects, good adhesion of the individual layers, and good processing properties. Furthermore, they contain biodegradable materials made from sustainable raw materials, preferably consisting of more than 50% bio-based raw materials, and do not contain inorganic or metallic layers, as in the commercially available effect films and luster pigments known to date.

[0011] The effect pigments according to the invention and the polymers used in the multilayer film can be simultaneously extruded, cut and laminated without the need for subsequent stretching and show very good adhesion even without additional auxiliaries. Suitable polymers are commercially available. The pigments and multilayer films according to the present invention preferably consist exclusively of organic materials, particularly preferably exclusively of biodegradable organic materials, and preferably contain no inorganic materials. The two polymers are preferably selected from biodegradable organic polymers which may be crosslinked. A particularly preferred material combination consists of PLA (polylactic acid, e.g., made from renewable corn starch), preferably a copolymer of D-lactic acid and L-lactic acid monomers, or a PLA blend, as the first polymer, and PBAT (polybutylene adipate / terephthalate), preferably a random copolymer, as the second polymer. This combination is particularly advantageous because the two copolymers can be coextruded in the same temperature range and have well-matched rheological properties, such as viscosity. Further preferred biodegradable polymers are mixtures of thermoplastic starch (TPS) with the above or other biodegradable polymers, mixtures of PBAT with PLA (e.g., BASF's Ecovio series), Bio-PA6 and Bio-PA11, or polyhydroxyalkanoates such as polyhydroxybutyrate-co-hydroxyvalerate (PHB / PHV).

[0012] Depending on the selected polymer combination and the refractive index difference Δn between the first and second polymers, also referred to below as polymer A and polymer B, the nanoscale polymer layer thickness d of polymer A / B ポリマーA / B (In the formula, n ポリマーA B represents the refractive index of polymer A or B), the polymer film, when not oriented or stretched, will in principle have a reflection peak λ in the wavelength range λ = 380 to 740 nm according to the following formula (1): ピーク Since the color effect due to second-order interference is very weak, only first-order interference is considered here.

number

[0013] [Figure 1]As an example, the formation of an interference effect in an effect pigment and multilayer film according to the invention is shown, which has an optically active layered sequence ABABA consisting of alternating individual layers of polymer A (PLA) with a refractive index n of 1.436 and a layer thickness dA and individual layers of polymer B (PBAT) with a refractive index n of 1.598 and a layer thickness dB. Here, incident light (arrow "a") is reflected at each interface where the refractive index changes, and the reflected light waves (arrow "b") interfere. Transmitted light is indicated by arrow "c." The multilayer film is terminated on both sides with the same polymer layer A or B (here A) as needed to achieve the required film stability. The thickness of these stabilizing top layers amounts to approximately 8% of the total film thickness, which has only a negligible effect on the interference effect. [Figure 2] The formation of a visible interference effect caused by the superposition of reflected radiation with an appropriate reflection wavelength depending on the individual layer thickness d of the effect pigments according to the invention having a layer sequence ABABAB...A (where A is the outermost stabilizing layer) and the material combination PLA / PBAT and the polymers of the multilayer film is shown by way of example. By varying the individual layer thicknesses in a specific way, the desired reflection wavelength and color can be achieved for a specific refractive index. DETAILED DESCRIPTION OF THE INVENTION

[0014] In a preferred embodiment of the present invention, the effect pigments and multilayer films have an alternating layer-by-layer sequence (ABAB...), where A denotes a monolayer of a first polymer (polymer A) and B denotes a monolayer of a second polymer (polymer B), with one of the polymers (polymer A or B) forming the two outermost layers, for example ABABABAB....A or BABABA....B. The total number of optically active monolayers of the first and second polymers in the inventive effect pigments and multilayer films of this preferred embodiment is preferably 7 to 2049, in particular 15 to 1025, particularly preferably 31 to 513 and very particularly preferably 63 to 257. In a further preferred embodiment of the present invention, the effect pigments and multilayer films have an alternating layer-by-layer sequence (ABAB...), where A denotes a monolayer of a first polymer (polymer A) and B denotes a monolayer of a second polymer (polymer B), e.g. ABABAB...AB. The total number of optically active monolayers of first and second polymers in the inventive effect pigments and multilayer films according to this preferred embodiment is preferably 8 to 2048, in particular 16 to 1024, particularly preferably 32 to 512, and very particularly preferably 64 to 256. The average thickness of the individual layers of all polymer layers (i.e. each of their layers) in the effect pigments and multilayer films according to the invention is preferably 130 nm or less, particularly preferably 40 to 130 nm, very particularly preferably 60 to 130 nm. ポリマーA and d ポリマーB The thickness of the individual layers A and B can be adjusted by combining the following: In practice, the layer volume ratio of the individual layers A and B can be varied for this purpose, for example, 25% by volume:75% by volume, 50% by volume:50% by volume, or 75% by volume:25% by volume. Differences in the thickness of the individual layers in a multilayer film can result in multicolor effects, which can also certainly find use and may be desirable.

[0015] In a particularly preferred embodiment of the present invention, the effect pigments and multilayer films according to the invention have reflection wavelengths in the visible region of the spectrum, in particular in the range from 450 to 750 nm. The total thickness of all polymer layers in the effect pigments and multilayer films according to the invention is preferably 0.5 to 30 μm, particularly preferably 1 to 25 μm, very particularly preferably 4 to 18 μm. The refractive index of the first polymer (polymer A), when measured at a wavelength λ of 633 nm, is preferably 1.200 to 1.700, particularly preferably 1.300 to 1.600, and extremely particularly preferably 1.400 to 1.500. The refractive index of the second polymer (polymer B), when measured at a wavelength λ of 633 nm, is preferably 1.300 to 1.800, particularly preferably 1.400 to 1.700, and extremely particularly preferably 1.550 to 1.650. The refractive index of the first polymer (polymer A) is preferably smaller than the refractive index of the second polymer (polymer B). The refractive index difference Δn between the first polymer and the second polymer at a wavelength λ=633 nm is preferably 0.001 to 0.800, in particular 0.050 to 0.300, particularly preferably 0.100 to 0.200, and very particularly preferably at least 0.140.

[0016] The effect pigments and multilayer films according to the invention can also be pigmented or treated, if desired, with biodegradable dyes, such as liquid colorants (e.g. selected from FARRL's DLC series) or pre-pigmented masterbatches (e.g. selected from Finke's Fibaplast masterbatch series). However, in a particularly preferred embodiment according to the invention, the effect pigments and multilayer films according to the invention consist only of individual layers of the first and second polymers. The first and second polymers each preferably have a melting point in the range of 140 to 300° C. The difference in melting point between the first and second polymers is preferably 60 K or less, particularly preferably 40 K or less. Particularly preferred are polymers or individual layers which can be processed at the same temperature and have an individual layer thickness of 130 nm or less, in particular 60 to 130 nm, and a refractive index difference Δn of 0.14 or more (at λ=633 nm). In a particularly preferred embodiment of the invention, the individual layer thicknesses of both polymers are substantially the same, ie the layer volume ratio is about 50:50.

[0017] The effect pigments according to the invention preferably have a maximum diameter of 1 to 200 μm, particularly preferably 5 to 160 μm, very particularly preferably 10 to 120 μm. The effect pigments according to the invention are preferably flake-shaped. They preferably have an aspect ratio (shape factor or diameter / thickness ratio) of 1 to 200, particularly preferably 5 to 100, very particularly preferably 6 to 20. The effect pigments according to the invention preferably have the shape of a regular n-gon, with n=3 to 16, preferably 4 to 8. These shapes or other preferred shapes can be produced in a manner known to those skilled in the art by using tools or devices in each case suitable for comminuting multilayer films, such as, for example, comminution tools. Particle size is measured by laser diffraction of powders or pigment suspensions using commercially available equipment known to those skilled in the art (e.g. Malvern or Horiba).

[0018] A further preferred embodiment of the present invention relates to a mixture of two or more effect pigments according to the invention having different shades. A further preferred embodiment of the present invention relates to a mixture of two or more effect pigments according to the invention having different particle sizes and / or different color shades. The effect pigments according to the invention preferably have a color effect with a metallic appearance, particularly preferably gold, copper or silver.

[0019] In a preferred embodiment of the present invention, the method according to the invention for the preparation of effect pigments and multilayer films comprises the following steps: The first and second polymers are preferably extruded at elevated temperatures, layered together, cut, laminated, and passed through a film die, preferably at elevated temperatures, into a multilayer film structure. The above steps may be repeated multiple times. Preferably, the polymer film is not stretched or oriented after extrusion. The extrusion is preferably carried out at elevated temperatures, in particular at temperatures above 180°C, very particularly preferably above 200°C. The production of the multilayer film through the film die is preferably carried out at elevated temperatures, in particular at temperatures above 160°C, very particularly preferably at temperatures above 180°C. For the preparation of the effect pigments according to the invention, the multilayer film thus obtained is then punched, ground, cut or crushed in another way to give particles, which are optionally sorted according to size. Further suitable process conditions, auxiliaries and equipment such as extruders, film dies, grinding tools etc. will not be described in detail here but are known to those skilled in the art and are described in the literature.

[0020] Furthermore, the present invention relates to the use of the effect pigments, multilayer films and formulations according to the invention as described above and below, preferably in products selected from the group consisting of cosmetics, rinse-off products, packaging materials, decorative films, paints, printing inks and plastics. Furthermore, the present invention relates to formulations comprising one or more effect pigments according to the invention, in particular for use in the products and applications mentioned above and below. Furthermore, the present invention relates to products comprising one or more effect pigments or multilayer films according to the invention as described above and below.

[0021] The effect pigments according to the invention can be used for various applications, for example in products selected from cosmetics, rinse-off products, packaging materials, decorative films, inks and paints, in particular cosmetic or rinse-off formulations, automotive paints, powder coatings, printing inks, security printing inks, plastics, ceramic materials, glass, paper, paper coatings, toners for electrophotographic printing processes, seeds, greenhouse films, tarpaulins, the preparation of pigment slurries with water, organic solvents and / or aqueous solvents, the preparation of pigment formulations or dry-prepared formulations, the liquid coloration of foods, the coloration of coatings for foods or pharmaceuticals, and securities. The production of such products is carried out by methods known to those skilled in the art. The effect pigments according to the invention can preferably be used in cosmetic applications, such as lipsticks, lip glosses, rouge, eyeliners, eye shadows, (volumizing) mascaras, nail varnishes, day creams, night creams, body lotions, cleansing milks, body powders, sticks, hair gels, hair masks, hair dyes, hair conditioners, hair shampoos, shower gels, body washes, shower oils, bath additives, sunscreens, make-up, care creams, lotions, soaps, bath salts, toothpastes, face masks, compact powders, loose powders and gels. The production of such products is carried out in a manner known to those skilled in the art. The multilayer films according to the invention are particularly suitable for use in cosmetics and / or as packaging materials and decorative films (also called effect films).

[0022] In various applications, the effect pigments according to the invention can also be used in mixtures with other absorption and / or effect pigments, such as pearlescent pigments, effect pigments, goniochromatic pigments, BiOCl flakes, multilayer pigments, metallic pigments, organic dyes, organic colored pigments, and other pigments, such as transparent and opaque white, colored, and black pigments, and conventional transparent, colored, and black luster pigments based on flake-form iron oxide, holographic pigments, LCP (liquid crystal polymers), and metal oxide-coated mica and SiO2 flakes. The effect pigments according to the invention can be mixed with commercially available (effect) pigments in any proportion. The effect pigments and multilayer films according to the invention can also be pigmented with natural dyes if desired.

[0023] Furthermore, the formulations and products according to the invention may comprise, in addition to the effect pigments according to the invention, further ingredients or additives, in particular selected from the group consisting of absorbents, astringents, antibacterial substances, antioxidants, antiperspirants, antifoaming agents, antidandruff agents, antistatic agents, binders, biological additives, bleaching agents, chelating agents, deodorants, emollients, emulsifiers, emulsion stabilizers, pigments, humectants, film-forming agents, fillers, fragrances, flavorings, insect repellents, preservatives, corrosion inhibitors, cosmetic oils, solvents, oxidizing agents, botanical ingredients, buffer substances, reducing agents, surfactants, propellants, opacifying agents, UV filters and UV absorbers, denaturants, viscosity modifiers, perfumes and vitamins. Without further explanation, it is assumed that those skilled in the art can utilize the above description to the fullest extent. Therefore, the preferred embodiments and examples should be considered merely illustrative and do not limit the disclosure in any way. All starting components are commercially available or can be synthesized by known methods.

[0024] Example 1 To prepare a blue effect pigment, PLA is used as polymer A and PBAT as polymer B in a volume ratio of 50:50. PLA stands for polylactic acid; the commercial product used is Ingeo® 4043 from NatureWorks, with a refractive index of n=1.454 (633 nm). PBAT stands for polybutylene adipate terephthalate, a random copolymer of the monomers 1,4-butanediol, adipic acid, and terephthalic acid; the commercial product used is Ecoflex® F-Blend C1200 from BASF, with a refractive index of n=1.598 (633 nm). Two polymers, A and B, are coextruded at 215°C, layered one on top of the other, i.e., cut and laminated at 215°C, and then passed through a film die at 210°C to form the final film. This simultaneous processing at the same temperature is facilitated by the similar dynamic viscosities of the two polymers, ranging from 0.2 to 0.4 MPa·s. Five cutting / laminating operations produce a multilayer film containing a total of 64 individual layers, each 60 nm thick. The multilayer film is cut / punched to produce particles on the order of 5-200 μm in size, resulting in pigment particles that exhibit a blue hue with a metallic appearance.

[0025] Example 2 For the preparation of greenish metallic effect pigments, PLA is used as polymer A and PBAT as polymer B, as described in Example 1. Two polymers, A and B, are coextruded at 215°C, interleaved, i.e., cut and laminated at 215°C, and then passed through a film die at 210°C to form the final film. This simultaneous processing is facilitated by the similar dynamic viscosities of the two polymers, ranging from 0.2 to 0.4 MPa·s, at the same temperature. A multilayer film containing a total of 128 individual layers, with individual PLA layers 125 nm thick and individual PBAT layers 115 nm thick, is produced through six cutting / laminating operations. This multilayer film is then cut / punched to obtain particles of size on the order of 5-200 μm, resulting in pigment particles with a greenish tint that have a metallic appearance.

[0026] Example 3 To produce reddish gold or copper metallic effect pigments, PLA is used as polymer A and PBAT as polymer B, as described in Example 1. Two polymers, A and B, are coextruded at 215°C, interleaved, i.e., cut and laminated at 215°C, and then passed through a film die at 210°C to form the final film. This simultaneous processing is easily achieved at the same temperature because the dynamic viscosities of the two polymers are similar, ranging from 0.2 to 0.4 MPa·s. A multilayer film containing a total of 128 individual layers, with individual PLA layers 125 nm thick and individual PBAT layers 160 nm thick, is produced in six cutting / laminating operations. The multilayer film is then cut / punched into particles on the order of 5-200 μm in size, resulting in pigment particles that exhibit a reddish gold or metallic copper appearance hue.

[0027] Example 4 When pigment particles with a metallic green, red and blue appearance prepared according to Examples 1 to 3 are mixed, a mixture of effect pigments with a silvery sheen is obtained.

[0028] The above examples confirm that effect pigments and multilayer films according to the invention can be produced in a wide range of colours directly from commercially available biodegradable polymers in a simple and inexpensive process, without further additives or process steps such as stretching. In contrast, commercially available luster pigments with a silvery sheen, such as 1S Silver or 2S Bright Silver from Moplatec / RJA Plastics GmbH, are not composed of biodegradable materials, but are cut from a polymer film formed from a PET core, coated on one side with aluminum by vacuum deposition, and then coated on both sides with an epoxy protective film.

Claims

1. 1. An effect pigment comprising, preferably consisting of, two or more transparent layers of a first polymer and two or more transparent layers of a second polymer, said two polymers having different refractive indices, said layers of said first polymer and said second polymer being arranged in an alternating manner, said two polymers being selected from biodegradable polymers.

2. 2. The effect pigment according to claim 1, characterized in that the average individual layer thickness of all polymer layers is 130 nm or less.

3. 2. The effect pigment according to claim 1, characterized in that the first polymer is PLA (polylactic acid) or a mixture of PLA and the second polymer is PBAT (polybutylene adipate terephthalate), in particular PBAT as a random copolymer.

4. 2. Effect pigments according to claim 1, characterized in that the individual average layer thickness of all polymer layers is 40 to 130 nm, particularly preferably 60 to 130 nm.

5. 2. The effect pigment according to claim 1, characterized in that the total number of all individual layers of the first and second polymers is 7 to 2049, in particular 15 to 1025, particularly preferably 31 to 513, and very particularly preferably 63 to 257.

6. 2. The effect pigment according to claim 1, characterized in that the refractive index of the first polymer at a wavelength λ=633 nm is from 1.200 to 1.700, particularly preferably from 1.300 to 1.600 and very particularly preferably from 1.400 to 1.500, and the refractive index of the second polymer (polymer B) at a wavelength λ=633 nm is preferably from 1.300 to 1.800, particularly preferably from 1.400 to 1.700 and very particularly preferably from 1.550 to 1.

650.

7. 2. The effect pigment according to claim 1, wherein the refractive index difference Δn between the first polymer and the second polymer at a wavelength λ=633 nm is 0.001 to 0.800, in particular 0.050 to 0.300, particularly preferably 0.100 to 0.200, and very particularly preferably at least 0.

140.

8. 2. Effect pigments according to claim 1, characterized in that the total thickness of all polymer layers is from 0.5 to 30 μm, particularly preferably from 1 to 25 μm, very particularly preferably from 4 to 18 μm.

9. 2. Effect pigments according to claim 1, characterized in that they have a shape factor (diameter / thickness ratio) of 1 to 200, preferably 5 to 100, particularly preferably 6 to 20.

10. 2. A method for making effect pigments according to claim 1, characterized in that the first and second polymers are respectively co-extruded (preferably at elevated temperature), laid one on top of the other (and optionally cut), laminated and passed through a film die into a multilayer film structure (preferably at elevated temperature), the above steps may be repeated multiple times, the polymer film is preferably not stretched or oriented after extrusion, and the multilayer film thus obtained is otherwise die-cut, ground, cut or crushed into particles, which particles may be sorted by size.

11. A formulation comprising one or more effect pigments according to any one of claims 1 to 9.

12. 10. Use of an effect pigment according to any one of claims 1 to 9 or a formulation comprising one or more effect pigments according to any one of claims 1 to 9 in a product selected from the group consisting of cosmetics, rinse-off products, packaging materials, decorative films, paints, printing inks, plastics.

13. 10. An article selected from the group consisting of cosmetics, rinse-off products, packaging materials, decorative films, paints, printing inks and plastics, comprising one or more effect pigments according to any one of claims 1 to 9 or a formulation comprising one or more effect pigments according to any one of claims 1 to 9.

14. 14. The article of claim 13, comprising one or more additives selected from binders, effect pigments and absorption pigments.

15. 10. A multilayer film comprising, preferably consisting of, two or more transparent layers of a first polymer and two or more transparent layers of a second polymer, wherein the layers of the first polymer and the layers of the second polymer are arranged alternately, the two polymers being as defined in any one of claims 1 to 8, and the average individual layer thickness of all polymer layers being 130 nm or less.

16. 16. The method for producing a multilayer film according to claim 15, wherein the first and second polymers are extruded (preferably at an elevated temperature), layered one on top of the other (and may be cut), laminated, and passed through a film die (preferably at an elevated temperature) into a multilayer film structure, the above steps may be repeated multiple times, and the polymer film is preferably not stretched or oriented after extrusion.

17. 16. Use of a multilayer film according to claim 15 in and / or as a packaging material or decorative film.

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