Food supplies

Abstract

Food contact materials with a color difference ΔE <20 from the L*a*b* coordinates to a color number starting with "1" of the RAL color chart according to the color model according to EN ISO 11664-4, as determined according to DIN 5033 (1979), based on compositions containing at least one polyester or polystyrene and a colorant consisting of at least one yellow methine dye or at least one yellow quinophthalone dye and at least one ethylene oxide-propylene oxide block copolymer with a central propylene oxide unit between two ethylene oxide units, a molar mass determined from the OH number to be determined according to DIN / ISO 4629, in the range of 5500 to 7500 g / mol, a mass fraction of ethylene oxide units in the range of 45 to 55 wt.% and a flocculation point to be determined according to EN 1890 method B in the range of 70°C to 85°C.

Description

[0001] The invention relates to food contact materials with a color difference ΔE <20 from the L*a*b* coordinates to a color number starting with “1” of the RAL color chart according to the color model according to EN ISO 11664-4, as determined according to DIN 5033 (1979), based on compositions containing at least one polyester or polystyrene and a colorant consisting of at least one yellow methine dye or yellow quinophthalone dye and at least one ethylene oxide-propylene oxide block copolymer with a central propylene oxide unit between two ethylene oxide units and the characteristics of a molar mass, determined from the OH number to be determined according to DIN / ISO 4629, in the range of 5500 to 7500 g / mol, and a mass fraction of ethylene oxide units in the range of 45 to 55 wt.-% and a flocculation point in the range of 70°C to 85°C, a process for the production of such a colorant, and the use of this colorant for the production of food contact materials based on yellow methine dye or yellow quinophthalone dye. State of the art

[0002] There are known processes for drying dyes for use in plastics in vacuum ovens or paddle dryers. For this, the dye particles must be ground in a mill, which generates a great deal of dust and therefore results in losses. Consequently, considerable equipment, such as extraction systems, is used to avoid or reduce dust pollution during dye processing.

[0003] Processes for producing dyes in granular or powder form, also known as color preparations, are known to those skilled in the art. These processes involve spraying dispersions or, preferably, solutions of dyes and, optionally, plasticizers, surfactants, and other additives into melts of waxes and / or resins that are insoluble or sparingly soluble in water. A disadvantage of these known processes is the dust nuisance and the high concentrations of surfactants, dispersing agents, and other additives used to prevent it.

[0004] In EP-A 488 933, EO / PO block polyether polyols with a molecular weight of 900-15000, calculated from the OH number, are used as dispersants for the production of solid preparations in granular form, among other things based on the yellow methine dye Solvent Yellow 179 of formula (I) As described in EP-A 488 933, this yellow dye is spray-dried to a microgranulate with a copolymer of propylene oxide and ethylene oxide with a mean molar mass of approximately 6500 g / mol and with polyacrylic acid with a mean molar mass of approximately 3000 g / mol.

[0005] More recently developed copolymers of propylene oxide and ethylene oxide (EO / PO block copolymers) are commercially available as poloxamers under the brand name Pluronic®. These poloxamers are surfactant-like block copolymers with a central polypropylene glycol moiety linked to a macrogol moiety at each end of the chain. The polyethylene oxide moiety of the block copolymer is water-soluble, while the polypropylene oxide moiety is not, resulting in amphiphilic properties. Depending on the degree of ethoxylation, poloxamers are liquid (L), paste-like (P), solid (F), or powder-like. Poloxamers are characterized by a two- or three-digit number sequence, where the last digit, multiplied by a factor of 10, approximately indicates the relative mass fraction of the ethylene oxide units in percent, and the preceding digit(s), multiplied by a factor of 100, encodes the relative molecular mass of the polypropylene glycol block. Food supplies

[0006] Food comes into contact with objects made of various materials during production, packaging, storage, preparation, and finally, consumption. These objects are known as food contact materials. The substances used in the manufacture of food contact materials are clearly regulated by law and subject to official monitoring. Food contact materials must not release any ingredients or components into food in quantities that could pose a health risk. They must also not cause any unacceptable changes to the food or impair its odor or taste. These general safety requirements for food contact materials are enshrined in Regulation (EC) No. 1935 / 2004, as well as nationally in the Food and Feed Code and the Consumer Goods Ordinance.General guidelines for good manufacturing practice can be found in Regulation (EC) No 2023 / 2006. In addition, several material-specific regulations have been adopted at the European level, for example, Regulation (EU) No 10 / 2011, which relates to plastic food contact materials. This EU Plastics Regulation contains, in particular, a list of certain substances that may be used in the manufacture of plastic food contact materials. The authorizations include substance-specific maximum levels and, where necessary, are restricted to specific applications. The inclusion of substances in the list requires a comprehensive health assessment by the European Food Safety Authority. See also: https: / / www.bmel.de / DE / themen / verbraucherschutz / lebensmittelsicherheit / lebensmittelverpackungen / lebensmittelverpackungen_node.html

[0007] Food contact materials are known to those skilled in the art from DE 10 2017 216 194 A1, which describes at least a first component, designed as an injection-molded part, with at least a second component, which is manufactured by means of 3D printing and connected to the first component. The first component and the second component are of different colors, for example by adding color particles.

[0008] In today's self-service age, packaging, as a form of food contact material, must primarily do one thing: sell the product. A significant portion of purchasing decisions are made emotionally at the point of sale, making it crucial that packaging appeals to customers in terms of color, shape, function, and size. Color is a key visual criterion. It attracts attention, reinforces brand imagery, and is more memorable than text. Unlike brand names, colors are also understood by most people. They work subconsciously, triggering emotions and evoking associations. For packaging colors, it is particularly important that they consistently adhere to a corporate design. This is especially true for brands that use color as a typical identifying mark, such as the purple of the Milka® brand.To guarantee brand recognition, colors must always match the design template as precisely as possible. Choosing the right color is not only a creative but also a technical challenge.

[0009] According to R. Mayer de Groot et al., "The Unconscious Power & Effect of Colors in Design & Marketing," MAYER DE GROOT Marketing Research and Consult GmbH 2018, page 15, yellow is associated worldwide with light, brightness, warmth, truth, knowledge, and clarity. In Asia, yellow always signifies good things. A yellow dragon or a yellow spring are considered auspicious. In China, yellow represents birth, health, sociability, exchange, gratitude, honors, wisdom, patience, tolerance, and the emperor, while in Japan it symbolizes grace and nobility. In the Orient, yellow represents authority, success, power, and wealth.

[0010] Based on the teaching of DE 10 2017 216 194 A1 concerning food contact materials, the object of the present invention was therefore to provide food contact materials based on at least one polyester or polystyrene and at least one yellow methine dye or one yellow quinophthalone dye, wherein the processing, in particular in injection molding, blow molding or extrusion, should produce products for the food sector that are as free as possible from specks while retaining the color impression resulting from the dye used.This led to a further objective: to provide an improved process for the production of free-flowing, low-dust yellow methine dye granules or yellow quinophthalone dye granules, free from additives, in particular free from the polyacrylic acid used in EP-A 488 933, enabling the production of such food contact materials using conventional polyester or polystyrene processing methods, especially injection molding, blow molding, or extrusion, with as few specks as possible in the final product while maintaining the yellow color impression resulting from the methine dye or quinophthalone dye used. Yellow food contact materials are known to those skilled in the art, for example, in the form of margarine packaging of the brand Rama (Flora Food Germany GmbH, Hamburg) or for concealing gimmick figures or construction kits as the contents of Kinder Surprise eggs (Ü-Ei) from Ferrero Deutschland GmbH, Frankfurt am Main.

[0011] Similar to the case of color streaks, colorants tend to form speckles under extreme conditions, such as those encountered in plastics processing, particularly on the surfaces of injection-molded products. Undesirable speckles occur when the colorant is insufficiently mixed, when the colorant and the plastic being processed are incompatible, or when segregation occurs due to excessive shear during injection molding. There are numerous potential sources of such unwanted speckles. These include, for example, machine-related defects in the mixing screw, an undersized mixing cylinder, faulty color dosing, an oversized material hopper, or electrostatic charging of the colorant.Material-related defects can include incompatibility of the colorant with the plastic being processed, insufficient solubility of the colorant in the plastic, thermal sensitivity of the colorant, excessively large granules, or an excessively high pigment content. Method-related defects can include insufficient back pressure during injection molding, excessively high screw speed, excessively high or low melt temperature, excessively high or low injection speed, excessively high or low mold temperature, or insufficient or excessive colorant dosage. Finally, mold-related defects can also promote the occurrence of specks, such as excessively small flow cross-sections, excessively long flow paths, unfavorable weld line placement, or sections on the injection-molded part that are too small for injection molding.Especially in the case of yellow food contact materials, the speck-free processing of polyester or styrene-based molding compounds, particularly in injection molding, is therefore a particular challenge for the expert, even for purely optical reasons. Solution to the task

[0012] Surprisingly, it was found that yellow methine dyes or yellow quinophthalone dyes, in combination with at least one ethylene oxide-propylene oxide block copolymer (EO / PO block copolymer) with a central propylene oxide unit between two ethylene oxide units, a molar mass, determined from the OH number to be determined according to DIN / ISO 4629, in the range of 5500 to 7500 g / mol, a mass fraction of ethylene oxide units in the range of 45 to 55 wt.% and a flocculation point to be determined according to EN 1890 method B in the range of 70°C to 85°C can be ground in a mill in a single pass within 15 minutes, resulting in a colorant with a particle size d50 in the range of 1 to 20 µm as determined according to ISO 13320, or a chip size of only 2.25 + / -1 (see Fig. 1).

[0013] Processed into a microgranulate, the d50 achievable for the yellow methine dye or yellow quinophthalone dye in the range of 1 to 20 µm with a chip value of only 2.25 + / - 1 enables the speck-free production of polyester or polystyrene-based food contact materials by injection molding, extrusion or blow molding with a color difference ΔE <20 from the L*a*b* coordinates to a color number starting with "1" of the RAL color chart according to the color model according to EN ISO 11664-4.

[0014] The use of the ethylene oxide-propylene oxide block copolymer according to the invention surprisingly enables the particle size distribution of a yellow methine dye or a yellow quinophthalone dye to be harmonized by milling in such a way that the milled mixture remains free-flowing and, when processed into microgranules, enables the speck-free production of polyester-based food contact materials with high optical requirements, which cannot be achieved with alternative additives such as Aduxol® VP-5342!

[0015] The solution to the problem and the subject matter of the invention are therefore food contact materials with a color difference ΔE <20 from the L*a*b* coordinates to a color number starting with "1" of the RAL color chart according to the color model according to EN ISO 11664-4, to be determined according to DIN 5033 (1979), based on compositions containing at least one polyester or polystyrene and a colorant consisting of at least one yellow methine dye or one yellow quinophthalone dye and at least one ethylene oxide-propylene oxide block copolymer (EO / PO block copolymer) with a central propylene oxide unit between two ethylene oxide units, a molar mass determined from the OH number to be determined according to DIN / ISO 4629, in the range of 5500 to 7500 g / mol, a mass fraction of ethylene oxide units in the range of 45 to 55 wt.% and a flocculation point to be determined according to EN 1890 method B in the range of 70°C to 85°C.

[0016] The invention further relates to a process for producing a colorant by combining an aqueous dispersion containing at least one yellow methine dye or at least one yellow quinophthalone dye and 0.1 to 5 wt.%, based on the dry yellow methine dye or dry yellow quinophthalone dye, an ethylene oxide-propylene oxide block copolymer (EO / PO block copolymer) with a central propylene oxide unit between two ethylene oxide units, a molar mass determined from the OH number to be determined according to DIN / ISO 4629, in the range of 5500 to 7500 g / mol, and a mass fraction of ethylene oxide units in the range of 45 to 55 wt.-% and a flocculation point to be determined according to EN 1890 method B in the range of 70°C to 85°C for a period of up to 60 min, preferably up to 15 min, to a particle size d50 to be determined according to ISO 13320 in the range of 1 to 20 µm, preferably 2 to 10 µm, and a chip value in the range of 2.25 + / - 1 in a mill, preferably a bead mill, with the proviso that the term yellow stands for a color distance ΔE <20 from the L*a*b* coordinates to a color number starting with “1” of the RAL color chart according to the color model according to EN ISO 11664-4. Definitions of terms

[0017] For the avoidance of doubt, it should be noted that the scope of the present invention encompasses all the general or preferred definitions and parameters listed below in any combination. This also applies to the combination of quantities of the individual components in relation to the methods and uses also claimed. The standards cited in this application refer to the version in force on the filing date of this invention. Unless otherwise stated, percentages are percentages by weight.

[0018] For clarification, it should further be noted that, according to the invention, a "food contact material" is understood to be a unit which is intended to come into contact with at least one foodstuff and which in particular has at least one surface area which is in contact with at least one foodstuff in at least one operating state and which touches the foodstuff and / or dishes and / or cutlery and / or containers, in particular bottles, and / or which is integrated into at least one household appliance which is intended for the preparation and / or storage and / or processing of foodstuffs and / or for the cleaning of dishes and / or cutlery and / or containers, in particular bottles.In particular, a food contact material according to the invention consists at least partially and advantageously at least to a large extent of at least one food-grade polyester or polystyrene, which is particularly compatible with food and / or non-toxic with regard to its ingredients. Alternatively, it is also referred to as a food contact material. Metrological color determination

[0019] The color coordinates of monochromatic colors, determined metrologically (colorimetrically) according to DIN 6174 or ISO 7724, are "L*" (for lightness), "a*" (for position on the green-red axis), and "b*" (for position on the blue-yellow axis), or the colorimetric values ​​"x, y, z" or "L*, C*" (C* for color intensity = chroma) and "h" (for hue). The standardized color order system (called CIELab) allows for the unambiguous determination and measurement of a color according to DIN 5033 (1979) in the color space, as well as the calculation and quantification of the color difference, denoted by delta E (ΔE*). ab ), in the case of minor color differences. Yellow

[0020] Within the scope of the present invention, yellow is defined as a color that, according to the RAL color system (https: / / de.wikipedia.org / wiki / RAL-Farbe#Gelb), has a color number in the RAL color chart that begins with "1". Specifically, as of the filing date of the present invention, the following shades of yellow are distinguished according to Table 1: Table 1 L* a* b* RAL 1000 Green-beige 80 1 24 RAL 1001 Beige 78 6 23 RAL 1002 Sand yellow 77 7 33 RAL 1003 Signal yellow 79 17 79 RAL 1004 Golden yellow 71,42 15,28 69,28 RAL 1005 Honey yellow 69 13 70 RAL 1006 Corn yellow 72 20 74 RAL 1007 Daffodil yellow 72 24 74 RAL 1011 Brownish beige 59,92 11,35 29,17 RAL 1012 Lemon yellow 75,04 4,64 61,31 RAL 1013 Pearl white 90 1 9 RAL 1014 ivory 84 4 21 RAL 1015 Light ivory 88 3 14 RAL 1016 Sulfur yellow 88,37 -9,78 71,30 RAL 1017 Saffron yellow 76,32 19,37 51,02 RAL 1018 Zinc yellow 83,35 3,46 75,83 RAL 1019 Grey-beige 62,62 4,31 12,94 RAL 1020 Olive yellow 61,98 0,39 32,18 RAL 1021 Rapeseed yellow 82 10 80 RAL 1023 Traffic yellow 82 11 80 RAL 1024 Ochre yellow 64,26 8,49 41,49 RAL 1026 Bright yellow 97 -15 90 RAL 1027 Curry yellow 58,15 5,83 47,68 RAL 1028 melon yellow 77 25 78 RAL 1032 Broom yellow 76 11 76 RAL 1033 Dahlia yellow 71,74 27,78 71,68 RAL 1034 Pastel yellow 72,73 21,40 45,09 RAL 1035 Pearl beige 54,79 0,35 11,86 RAL 1036 Pearl gold 48,95 4,77 26,69 RAL 1037 Sun yellow 70,28 26,19 64,79

[0021] Table 1 lists the device-independent CIE L*a*b* color values ​​for each RAL value: L* represents the luminance, a* describes the chromaticity coordinates along the red-green axis, and b* describes the chromaticity coordinates along the yellow-blue axis using D65 standard illuminant with a 10° field of view of a standard observer. The color model is standardized in EN ISO 11664-4 "Colorimetry -- Part 4: CIE 1976 L*a*b* Colour space". For more information on the L*a*b* color space (also known as CIELAB), see: https: / / de.wikipedia.org / wiki / Lab-Farbraum. Each color in the color space is defined by a chromaticity coordinate with the Cartesian coordinates {L*, a*, b*}. The a*b* coordinate plane was constructed using opponent-process theory. Green and red are opposite each other on the a* axis, and the b* axis lies between blue and yellow. Complementary colors are positioned 180° opposite each other; all achromatic colors lie in their center (the origin of the coordinate system a*=0, b*=0).

[0022] The L* axis describes the brightness (luminance) of a color with values ​​from 0 to 100. In the diagram, it is perpendicular to the a*b* plane at the origin. It can also be called the neutral gray axis, because all achromatic colors (shades of gray) are contained between the endpoints black (L*=0) and white (L*=100). The a* axis describes the green or red component of a color, with negative values ​​representing green and positive values ​​representing red. The b* axis describes the blue or yellow component of a color, with negative values ​​representing blue and positive values ​​representing yellow. The a* values ​​range from approximately -170 to +100, and the b* values ​​from -100 to +150, with the maximum values ​​only being reached at medium brightness for certain hues. The CIELAB color solid has its greatest extent in the mid-brightness range, but this extent varies in height and size depending on the color range.

[0023] The desired color impression of food contact materials according to the invention can be determined by the color intensity, which is lower when specks remain. The work carried out within the scope of the present invention also showed that the use of an EO / PO block copolymer according to the invention narrows the particle size distribution of the yellow methine dye or the yellow quinophthalone dye by milling, reduces the mean particle size, and the additive simultaneously keeps the milled mixture flowable. A propylene oxide and ethylene oxide copolymer according to EP-A 0 488 933, having only the characteristic of a mean molar mass, calculated from the OH number to be determined according to DIN / ISO 4629, of approximately 6500 g / mol and without the additional characteristics of a mass fraction of ethylene oxide units in the range of 45 to 55 wt.With a concentration of -% and a flocculation point in the range of 70°C to 85°C, the particle size distribution could not be reduced sufficiently by milling within the same timeframe to allow for a reduction in speck formation or speck-free state in an injection-molded product based on the measured color intensities. On the contrary, a method according to the invention surprisingly allowed for longer milling times without the particle size distribution of the yellow methine dye or the yellow quinophthalone dye being affected or thickened by flocculation, thus preventing further processing. According to the invention, aqueous dye dispersions suitable for the production of rapidly soluble granules could be produced. The smaller the average particle size and distribution width of the dye particles that make up the granules, the faster they can dissolve, for example, in a plastic.This makes the processing of a plastic colored with a yellow methine dye or yellow quinophthalone dye in injection molding, extrusion or blow molding processes faster and at the same time less prone to malfunctions.

[0024] Due to a broader particle size distribution, yellow methine dyes or yellow quinophthalone dyes, which are significantly less dispersible, are only partially dissolved in the plastic and tend to form specks in the plastic processing product, particularly in food contact materials, resulting in an undesirable color appearance. The work carried out within the scope of the present invention surprisingly shows, after milling, that when using an EO / PO block copolymer with a central propylene oxide unit between two ethylene oxide units, a molar mass determined from the OH number to be determined according to DIN / ISO 4629 in the range of 5500 to 7500 g / mol, and a mass fraction of ethylene oxide units in the range of 45 to 55 wt.-% and a flocculation point determined according to EN 1890 Method B in the range of 70°C to 85°C without additives, the desired grind is achieved after a grinding time of only 15 minutes, and the width of the particle size distribution, measured by the "span", is reduced by more than 10% even after a very short grinding time of 5 minutes, while simultaneously reducing the sizing by at least 50%. Sizing, as understood by those skilled in the art, refers to the determination of particle size, i.e., the calculation of particle size and distribution. Particle size determination

[0025] The particle size d50 of the yellow methine dye or yellow quinophthalone dye under investigation, to be determined within the scope of the present invention, is carried out by laser diffractometry according to ISO 13320. For use in food contact materials, the particle size d50 is preferably in the range of 1 to 20 µm, with a d50 in the range of 2 to 10 µm being preferred. To determine the particle size d50 and the particle size, the optical properties of the yellow methine dye or yellow quinophthalone dye under investigation were determined during a meal over a period of 1 to 35 minutes and evaluated according to Mie theory; see: https:lide.wikipedia.orgiwiki / Lasertreibungs-Partikelgr%C3%B6%C3%9Fenanalyse.

[0026] The diameters d10, d50, and d90 are defined as the diameters at which 10%, 50% (median), and 90%, respectively, of the particles under investigation have a smaller diameter relative to the total volume; see also D. Monella et al., "Comparative Investigations on Particle Size Analysis," Chemie Ingenieur Technik (72), 3 / 2000, pages 273–276. The width of the particle size distribution is reflected by the span value (calculated from the sizing parameters d90, d50, and d10; span = (d90 – d10 / d50)). The d50 value, based on the value after 1 minute of milling, is chosen as a measure of the temporal development of the mean particle size. See Fig. 1. Methine dyes

[0027] Methine dyes (polymethine dyes) are dyes whose chromophore system consists of conjugated double bonds (polyenes) flanked by two end groups - an electron acceptor A and an electron donor D:

[0028] Preferred methine dyes are cyanine dyes in which both terminal groups of the chromophore contain nitrogen atoms, the amino and imino groups respectively being part of a heterocycle:

[0029] Preferred yellow methine dyes are also yellow hemicyanine dyes, wherein one terminal amino group is part of a heterocycle, while the second terminal group is open-chain:

[0030] A preferred yellow hemicyanine dye according to the invention is CI Basic Yellow 11 (CAS No. 4208-80-4) of formula (II)

[0031] Preferred yellow methine dyes are also yellow streptocyanine dyes in which the two terminal amino or imino groups of the chromophore are open-chain:

[0032] Preferred yellow methine dyes are also yellow merocyanine dyes, which have an amino and a carbonyl group as end groups of the polyene structural element and for which both a neutral and a zwitterionic mesomeric resonance structure can be formulated:

[0033] Preferred yellow methine dyes are also yellow oxonol dyes whose terminal groups contain oxygen as a heteroatom:

[0034] Preferred yellow methine dyes also include yellow styryl dyes obtained by condensation of an active methylene compound, for example malononitrile, with a benzaldehyde derivative. CI Disperse Yellow 31 (3), obtained by condensation of ethyl cyanoacetate (2) with a p-aminobenzaldehyde derivative (2), is known to those skilled in the art.

[0035] Preferred yellow methine dyes are also yellow di- or triarylmethine dyes. A diarylmethine dye preferred according to the invention is CI Solvent Yellow 34 Hydrochloride (CAS No. 2465-27-2) of formula (III).

[0036] Preferred yellow methine dyes according to the invention are 2-[[4-[2-(4-cyclohexylphenoxy)ethyl-ethylamino]-2-methylphenyl]methylidene]propanenitrile, known as Solvent Yellow 179, CAS No. 80748-21-6 or Macrolex® Yellow 6G of the above formula (I), or 4,4'-methylidenebis(5-methyl-2-phenyl-2,4-dihydro-3H-pyrazol-3-one), known as Solvent Yellow 93 [CAS No. 4702-90-3] or Macrolex® Yellow 3G of formula (IV). All available from LANXESS Deutschland GmbH, Cologne. Quinophthalon dyes

[0037] Quinophthalone dyes are already known to those skilled in the art from DE AS 1 261 105, in which halogenated variants are used for dyeing textile threads or textile fibers. A characteristic feature of quinoline dyes is that the quinoline unit in the molecule consists of two fused aromatic six-membered rings – a benzene ring and a pyridine ring. Further quinophthalone dyes are described in EP 83 553 A1 or the literature cited therein. Yellow dispersion dye mixtures, including those containing quinophthalone dyes, are described in DE 100 31 567 A1. Quinoline Yellow (E104), also known as CI Acid Yellow 3, [CAS No. 8004-92-0] according to formula (V), is particularly well known to those skilled in the art for coloring industrially produced foodstuffs.

[0038] Preferred according to the invention are 2-(3-Hydroxy-2-quinolyl)-1H-indene-1,3(2H)-dione [CAS No. 7576-65-0], also known as Solvent Yellow 114 or Macrolex® Yellow G according to formula (VI) or 6-(2,5-Dimethylbenzoyl)-3-hydroxy-2-(3-hydroxy-2-quinolinyl)-1 H-inden-1-one, known as Macrolex® Yellow E2R [CAS No. 198625-33-1] according to formula (VII) Both are available from LANXESS Deutschland GmbH, Cologne. Preferred embodiments of the invention

[0039] The inventive partial problem is to provide a process for producing a colorant based on free-flowing, low-dust, yellow methine dye granules or yellow quinophthalone dye granules, without the use of auxiliary substances, in particular without the polyacrylic acid mentioned in EP-A 0 488 933, which makes it possible to produce food contact materials without specks in conventional processes for processing polyesters or polystyrenes, in particular in injection molding, blow molding or extrusion.

[0040] In order to obtain food contact materials from processing processes, preferably injection molding, extrusion or blow molding, as free as possible from specks and while retaining the color impression resulting from the yellow methine dye or the yellow quinophthalone dye, the invention requires the use of a colorant containing at least one yellow methine dye or at least one yellow quinophthalone dye in the plastic to be processed, which contains at least one EO / PO block copolymer with a central propylene oxide unit between two ethylene oxide units, a molar mass determined from the OH number to be determined according to DIN / ISO 4629, in the range of 5500 to 7500 g / mol, a mass fraction of ethylene oxide units in the range of 45 to 55 wt.% and a flocculation point to be determined according to EN 1890 method B in the range of 70°C to 85°C.

[0041] Preferably, the food contact materials are those produced using an injection molding process, so-called injection-molded food contact materials.

[0042] The production of the colorant used according to the invention preferably proceeds as follows: the dye press cake of a yellow methine dye or a yellow quinophthalone dye, obtained from dye synthesis, is first intensively mixed discontinuously with the EO / PO block copolymer used according to the invention in a stirred tank, and optionally heated, wherein the temperature and solids content are selected such that the resulting dispersion of the dye can be readily atomized. Alternatively, a previously produced and stored yellow methine dye or yellow quinophthalone dye can also be used.

[0043] Preferably, 20 to 100 parts of the yellow methine dye or the yellow quinophthalone dye are added to 1 part of the ethylene oxide-propylene oxide block copolymer. Specifically, the 20 to 100 parts of the yellow methine dye or the yellow quinophthalone dye are mixed with 3 to 4 parts of demineralized water (DI water) at room temperature (approximately 23 ± 2 °C) with vigorous stirring. After stirring for up to 60 minutes, preferably up to 15 minutes, the resulting aqueous dye dispersion is preferably milled for up to 15 minutes.

[0044] Surprisingly, the EO / PO block copolymer used according to the invention yields a colorant which, after only 15 minutes of milling, is characterized by a narrower particle size distribution width and a span value of only 2.25 + / - 1 compared to the prior art according to ISO 13320!

[0045] Preferably, the colorant is a spray granulate. Therefore, before being incorporated / compounded into a plastic, here polyester or polystyrene, the colorant is preferably processed into spray granules by spray granulation and dried. Preferably, a rotating disc or pressure nozzle is used as the atomizing agent in the spray granulation process. A rotating disc or pressure nozzle as described in Chemiker Zeitung / Chem. Apparatur / Verfahrenstechnik, 93rd year (1969), No. 13, is preferably used as the atomizing agent. The preferably applied atomization can be carried out by selecting a suitable atomizing agent such that the particle diameters of the resulting spherical granules are within the ranges preferred for further processing.The preferred d50 range of 1 to 20 µm, particularly preferably 2 to 10 µm, is determined by laser diffractometry according to ISO 13320 and is suitable for use in food contact materials. This range is obtained by spraying with single-component nozzles, preferably at pressures up to 100 bar. The inlet temperature, i.e., at the inlet of the aqueous dispersion to the spray dryer, is preferably in the range of 100 to 240°C, and the outlet temperature (exit temperature of the granules) is preferably in the range of 80 to 90°C. The inlet and outlet temperatures depend on the required residual moisture content of < 0.5%, safety measures, or are selected based on the yellow methine dye or yellow quinophthalone dye being processed and its melting point. The colorants obtained according to the invention by spray granulation are low-dust and free-flowing.

[0046] Preferably, the mass of the EO / PO block copolymer in the dye, based on the dry dye, is a maximum of 5 wt%, preferably 1 to 4 wt%.

[0047] In another preferred embodiment, the ground material is screened by means of an annular channel or outside the dryer, preferably in a downstream fluidized bed. The colorant, in the form of granulated ground material, can be regranulated after liquefaction.

[0048] Preferably, the colorant is milled by wet milling in a rotor-stator mill or bead mill, particularly in a bead mill. The resulting dispersion, preferably with a d50 in the range of 1 to 20 µm, and especially preferably in the range of 2 to 10 µm, as determined according to ISO 13320, is then spray-dried to form microgranules in an atomizing dryer, preferably a pressure nozzle tower. This process yields the colorant in the form of microgranules, preferably with a particle size in the range of 50 to 300 µm, which, unlike the powder, are low in dust and free-flowing. The granules are stable during storage, meaning they are not destroyed by stress, particularly during transport. The dye content in the granules is preferably 95 to 99 wt.%.

[0049] The particle sizes of the colorant to be used as microgranules can vary widely and are preferably 5 to 800 µm, particularly preferably 50 to 300 µm.

[0050] Preferably, the colorant to be used according to the invention contains titanium dioxide as a white pigment in order to achieve a high opacity in accordance with DIN 55986.

[0051] The coloring of the polyesters or polystyrenes used for the food contact materials according to the invention with the colorant according to the invention is preferably carried out in bulk, as described, for example, in Coloring of Plastics, John Wiley and Sons, New York, 1979. The quality of the granules can be improved by performing a screening process, as described, for example, in US Patent 4,198,264. The ground material can be remixed and spray-dried.

[0052] Preferably, the microgranules are spray granules. Fluidized bed spray granulation is an innovative process for obtaining compact and nearly round granules with excellent physical properties. A suspension or emulsion of the EO / PO block copolymer used according to the invention, containing the yellow methine or chlorophthalone dye, is atomized in a fluidized bed and impacts nucleation sites in droplet form. The liquid evaporates, and the solid is drawn onto the nucleation site, forming a solid shell. This process is continuously repeated in the fluidized bed, resulting in very compact, shell-like (micro)granules, which is why it is also referred to as a layering process. Parameters such as particle size, residual moisture, and solids content can be very precisely controlled in fluidized bed spray granulation.Since the drying and shaping processes occur simultaneously in fluidized bed granulation, this is also referred to as continuous fluidized bed spray drying granulation. In the present application, the short form spray granulation / spray granulate is used. The colorant to be used as spray granulate according to the invention is a very homogeneous granulate with a defined particle size distribution and precise residual moisture content, which is dust-free and exhibits excellent flow properties.

[0053] Preferably, the invention relates as an intermediate product according to the invention to spray granules containing at least one yellow methine dye or at least one yellow quinophthalone dye and at least one EO / PO block copolymer with a central propylene oxide unit between two ethylene oxide units, with a molar mass determined from the OH number to be determined according to DIN / ISO 4629, in the range of 5500 to 7500 g / mol, a mass fraction of ethylene oxide units in the range of 45 to 55 wt.% and a flocculation point to be determined according to EN 1890 method B in the range of 70°C to 85°C and the term yellow stands for a color distance ΔE <20 from the L*a*b* coordinates to a color number starting with “1” of the RAL color chart according to the color model according to EN ISO 11664-4, to be determined according to DIN 5033 (1979).

[0054] Preferably, the spray granules contain 20 to 100 parts of the yellow methine dye or the yellow quinophthalone dye per part of the ethylene oxide-propylene oxide block copolymer.

[0055] Preferably, the mass of the EO / PO block copolymer in the spray granules, based on the dry dye, is a maximum of 5 wt%, preferably 1 to 4 wt%.

[0056] Preferably, titanium dioxide is already used as a white pigment in the spray granules in order to achieve a high opacity when using the dyes in food contact materials in accordance with DIN 55986.

[0057] Spray granulation has the advantage over drying in a paddle dryer and grinding that there is significantly less dust pollution during production, since work from beating to the spray-dried (micro)granules takes place in an aqueous phase; furthermore, dry grinding with its known losses is eliminated, so this process delivers higher yields.

[0058] Preferably, food contact materials according to the invention have a color difference ΔE <20 from the L*a*b* coordinates to a color number beginning with "1" in the RAL color chart according to the color model according to EN ISO 11664-4, where the color number corresponds to RAL 1003, RAL 1016, RAL 1018, RAL 1026 or RAL 1028. Particularly preferably, the food contact materials have a color difference ΔE <20 from the L*a*b* coordinates of RAL 1016 and RAL 1018 according to the color model according to EN ISO 11664-4, which is to be determined according to DIN 5033 (1979).

[0059] Preferably, the color difference ΔE <10, particularly preferably ΔE <5, to be determined according to DIN 5033 (1979), is between the L*a*b* coordinates and a color number starting with “1” of the RAL color chart according to the color model according to EN ISO 11664-4.

[0060] According to the invention, Solvent Yellow 93 [CAS No. 4702-90-3], also known as Macrolex® Yellow 3G or 6-(2,5-Dimethylbenzoyl)-3-hydroxy-2-(3-hydroxy-2-quinolinyl)-1 H-inden-1-one or Macrolex® Yellow E2R [CAS No. 198625-33-1], both available from LANXESS Deutschland GmbH, Cologne, is particularly preferred for use. polystyrene

[0061] The polystyrene, also known as poly(1-phenylethylene) [CAS No. 9003-53-6], used in one embodiment of the invention for the manufacture of food contact materials, is a thermoplastic according to https: / / de.wikipedia.org / wiki / Polystyrol and belongs to the standard plastics. Polystyrene films and sheets are preferably produced by extrusion. The low shrinkage tendency of polystyrene during manufacturing allows for components that are very close to their final shape (cf. lost-foam process). Furthermore, very fine contours, edges, and flat surfaces can be produced, even for plastics. This property of polystyrene enables the production of relatively precisely fitting components. As packaging material, and thus in one embodiment as a food contact material, polystyrene is used, for example, as yogurt cups or foam trays. See: D. Bender, H. Gausepohl, D. Braun, R. Gellert: Polystyrene.Hanser Verlag 1995; ISBN 3-446-18004-4; pp. 467f: Requirements for polystyrene food packaging.

[0062] According to the invention, food contact materials, preferably injection-molded food contact materials, with a color difference ΔE <20 from the L*a*b* coordinates to a color number starting with “1” of the RAL color chart according to the color model according to EN ISO 11664-4, as determined according to DIN 5033 (1979), based on polymer compositions containing at least one polystyrene and a colorant consisting of at least one yellow methine dye or at least one yellow quinophthalone dye and at least one EO / PO block copolymer with a central propylene oxide unit between two ethylene oxide units and the characteristics of a molar mass, determined from the OH number to be determined according to DIN / ISO 4629, in the range of 5500 to 7500 g / mol, a mass fraction of ethylene oxide units in the range of 45 to 55 wt.% and a flocculation point in the range of 70°C to 85°C.

[0063] Food contact materials, preferably injection-molded food contact materials, are also preferred, with a color difference ΔE <20 from the L*a*b* coordinates to a color number starting with "1" of the RAL color chart according to the color model according to EN ISO 11664-4, as determined according to DIN 5033 (1979), based on polymer compositions containing at least one polystyrene and a colorant consisting of at least one yellow methine dye or at least one yellow quinophthalone dye and at least one EO / PO block copolymer with a central propylene oxide unit between two ethylene oxide units and the characteristics of a molar mass, determined from the OH number to be determined according to DIN / ISO 4629, in the range of 5500 to 7500 g / mol, and a mass fraction of ethylene oxide units in the range of 45 to 55 wt.-% and a flocculation point in the range of 70°C to 85°C, wherein 0.01 to 5 mass parts, particularly preferably 0.01 to 3 mass parts, of the methine dye or the quinophthalone dye are used per 100 mass parts of polystyrene.

[0064] According to the invention, the term polystyrene also includes styrene-containing plastics, so-called styrene copolymers. Preferred styrene copolymers are styrene-butadiene copolymers (SB plastics according to DIN EN ISO 1043-1 [CAS No. 9003-55-8]), acrylonitrile-butadiene-styrene terpolymers (ABS plastics [CAS No. 9003-56-9]), styrene-acrylonitrile copolymers (SAN plastics [CAS No. 9003-54-7]) or blends in the form of ABS+PC (with PC = polycarbonate, e.g., Bayblend® types from Covestro Deutschland AG) or ABS+PA (with PA = polyamide; e.g., Terblend® types from INEOS Styrolution Europe GmbH).

[0065] Food contact materials, preferably injection-molded food contact materials, are also preferred, with a color difference ΔE <20 from the L*a*b* coordinates to a color number starting with "1" of the RAL color chart according to the color model according to EN ISO 11664-4, as determined according to DIN 5033 (1979), based on polymer compositions containing at least one styrene copolymer and a colorant consisting of at least one yellow methine dye or at least one yellow quinophthalone dye and at least one EO / PO block copolymer with a central propylene oxide unit between two ethylene oxide units and the characteristics of a molar mass, determined from the OH number to be determined according to DIN / ISO 4629, in the range of 5500 to 7500 g / mol, and a mass fraction of ethylene oxide units in the range of 45 to 55 wt.-% and a flocculation point in the range of 70°C to 85°C, wherein 0.01 to 5 mass parts, particularly preferably 0.01 to 3 mass parts, of the methine dye or the quinophthalone dye are used per 100 mass parts of polystyrene, wherein the styrene copolymer is to be selected from styrene-butadiene copolymers, acrylonitrile-butadiene-styrene terpolymers, styrene-acrylonitrile copolymers, or blends in the form of ABS+PC or ABS+PA. polyester

[0066] Polyesters used according to the invention for the manufacture of food contact materials can be produced by various processes and synthesized from different building blocks. Preferably, at least one C2-C is used as the polyester. 10 -Polyalkylene terephthalate or at least a polycarbonate is used. C2-C 10 -Polyalkylene terephthalates

[0067] C2-C preferably used according to the invention 10Polyalkylene terephthalates are reaction products of an alcohol moiety (containing 2 to 10 carbon atoms) and terephthalic acid. C2-C 10 Polyalkylene terephthalates are known to those skilled in the art and are well described in the literature. They contain an aromatic ring in the main chain, derived from terephthalic acid, and an aliphatic part derived from a dihydroxy compound. The aromatic ring of terephthalic acid can also be substituted. Preferred substituents are halogens or C1-C4 alkyl groups. Preferred halogens are chlorine or bromine. Preferred C1-C4 alkyl groups are methyl, ethyl, n-propyl, or n-, i-, or t-butyl groups.

[0068] Preferably to be used C2-C 10 -Polyalkylene terephthalates can be prepared by reacting aromatic dicarboxylic acids, their esters or other ester-forming derivatives with aliphatic dihydroxy compounds in a manner known to those skilled in the art.

[0069] In the case of C2-C 10 In polyalkylene terephthalates, up to 30 mol% of the terephthalic acid used in their production can be replaced by 2,6-naphthalenedicarboxylic acid, isophthalic acid, or mixtures thereof. Up to 70 mol%, preferably not more than 10 mol%, of the terephthalic acid can be replaced by aliphatic or cycloaliphatic dicarboxylic acids such as adipic acid, azelaic acid, sebacic acid, dodecanedioic acids, and cyclohexane dicarboxylic acids.

[0070] Of the aliphatic dihydroxy compounds, diols with 2 to 6 carbon atoms are preferred, in particular 1,2-ethanediol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, 1,4-hexanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, and neopentyl glycol, or mixtures thereof. Particularly preferred polyalkylene terephthalates are derived from alkanediols with 2 to 4 carbon atoms. Of these, polyethylene terephthalate (PET), polypropylene terephthalate, and polybutylene terephthalate (PBT), or mixtures thereof, are especially preferred. PET and / or PBT containing up to 1 wt%, preferably up to 0.75 wt%, of 1,6-hexanediol and / or 2-methyl-1,5-pentanediol as further monomer units are also preferred.

[0071] Preferably, the C2-C to be used according to the invention have 10-Polyalkylene terephthalates exhibit a viscosity number m to be determined according to ISO 1628 in the range of 50 to 220, preferably in the range of 80 to 160, where measured in a 0.5 wt% solution in a phenol / o-dichlorobenzene mixture, wt. ratio 1:1 at 25°C.

[0072] C2-C preferred to be used according to the invention 10 Polyalkylene terephthalates preferably have a carboxyl end group content of up to 100 mEq / kg polyester, particularly preferably up to 50 mEq / kg polyester, and especially preferably up to 40 mEq / kg polyester. Such C2-C 10 Polyalkylene terephthalates can be produced, for example, according to the method described in DE-A 44 01 055. The carboxyl end group content is usually determined by titration methods, in particular potentiometry.

[0073] C2-C is particularly preferred for use 10Polyalkylene terephthalates are produced using Ti catalysts. After polymerization, these preferably have a residual Ti content of ≤250 ppm, particularly preferably <200 ppm, and most preferably <150 ppm.

[0074] The polybutylene terephthalate (PBT) [CAS No. 24968-12-5] preferably used according to the invention is produced from terephthalic acid or its reactive derivatives and butanediol according to known methods (Plastics Handbook, Vol. VIII, pp. 695-743, Karl Hanser Verlag, Munich 1973).

[0075] The polyethylene terephthalate (PET) [CAS No. 25038-59-9] preferably used according to the invention is produced from terephthalic acid or its reactive derivatives and ethylene glycol according to known methods (Plastics Handbook, Vol. VIII, pp. 695-743, Karl Hanser Verlag, Munich 1973).

[0076] Therefore, food contact materials, preferably injection-molded food contact materials, with a color difference ΔE <20 from the L*a*b* coordinates to a color number starting with “1” of the RAL color chart according to the color model according to EN ISO 11664-4, based on polymer compositions containing at least one C2-C, are preferred according to the invention. 10 -Polyalkylene terephthalate and a colouring agent consisting of at least one yellow methine dye or at least one yellow quinophthalone dye and at least one EO / PO block copolymer with a central propylene oxide unit between two ethylene oxide units and the characteristics of a molar mass determined from the OH number to be determined according to DIN / ISO 4629, in the range of 5500 to 7500 g / mol, a mass fraction of ethylene oxide units in the range of 45 to 55 wt.% and a flocculation point in the range of 70°C to 85°C.

[0077] Food contact materials, preferably injection-molded food contact materials, are also preferred, with a color difference ΔE <20 from the L*a*b* coordinates to a color number starting with “1” of the RAL color chart according to the color model according to EN ISO 11664-4, as determined according to DIN 5033 (1979), based on polymer compositions containing at least polyethylene terephthalate or polybutylene terephthalate and a colorant consisting of at least one yellow methine dye or at least one yellow quinophthalone dye and at least one EO / PO block copolymer with a central propylene oxide unit between two ethylene oxide units and the characteristics of a molar mass, determined from the OH number to be determined according to DIN / ISO 4629, in the range of 5500 to 7500 g / mol, a mass fraction of ethylene oxide units in the range of 45 to 55 wt.% and a flocculation point in the range of 70°C to 85°C.

[0078] Preferably, C2-C is used, with a mass fraction of 100. 10-Polyalkylene terephthalate or polyethylene terephthalate or polybutylene terephthalate 0.01 to 5 mass parts, particularly preferably 0.01 to 3 mass parts, of the methine dye or the quinophthalone dye are used. Polycarbonat

[0079] Preferably according to the invention, at least one thermoplastic from the group of polycarbonates can also be used as the polyester. Polycarbonates preferably used according to the invention are homopolycarbonates or copolycarbonates based on bisphenols of the general formula (VIII). HO-Z-OH (VIII) where Z represents a divalent organic residue with 6 to 30 C atoms containing one or more aromatic groups.

[0080] Preferably, at least one polycarbonate based on bisphenols of formula (VIIIa) is used as the polyester. wherein A for a single bond or for a residue of the series C1-C5 alkylene, C2-C5 alkylidene, C5-C6 cycloalkylidene, -O-, -SO-, -CO-, -S-, -SO2-, C6-C 12 -Arylene is formed, to which further aromatic rings, possibly containing heteroatoms, may be condensed, or A stands for a remainder of formula (IX) or (X). wherein R 7 and R 8 are individually selectable for each Y and independently represent hydrogen or C1-C6 alkyl, preferably hydrogen, methyl or ethyl, B each for C1-C 12 -Alkyl, preferably for methyl, halogen, preferably chlorine and / or bromine, stands for x each independently represents 0, 1 or 2, p represents 1 or 0, Y stands for carbon, and m represents an integer from 4 to 7, preferably 4 or 5, with the proviso that at least one Y (carbon atom) R 7 and R8 simultaneously stand for alkyl.

[0081] In a preferred embodiment, the following applies: If m stands for 4, then Y stands for -CR 7 R 8 -CR 7 R 8 -CR 7 R 8 -CR 7 R 8 -; If m stands for 5, then Y stands for - CR 7 R 8 -CR 7 R 8 -CR 7 R 3 -CR 7 R 8 -CR 7 R 8 -; If m stands for 6, then Y stands for -CR 7 R 8 -CR 7 R 8 -CR 7 R 8 -CR 7 R 8 -CR 7 R 8 -CR 7 R 8 -; and If m stands for 7, then Y stands for -CR 7 R 8 -CR 7 R 8 -CR 7 R 8 -CR 7 R 8 -CR 7 R 8 -CR 7 R 8 -CR 7 R 8 -

[0082] Preferred bisphenols are to be selected from the group consisting of dihydroxydiphenyls, bis-(hydroxyphenyl)-alkanes, bis-(hydroxyphenyl)-cycloalkanes, indanbisphenols, bis-(hydroxyphenyl)-sulfides, bis-(hydroxyphenyl)-ethers, bis-(hydroxyphenyl)-ketones, bis-(hydroxyphenyl)-sulfones, bis-(hydroxyphenyl)-sulfoxides and α,α'-bis-(hydroxyphenyl)-diisopropyl-benzenes.

[0083] Derivatives of the aforementioned bisphenols, which are preferably obtainable by alkylation or halogenation on the aromatic rings of the aforementioned bisphenols, are also preferred bisphenols to be used.

[0084] Besonders bevorzugte Bisphenole sind Hydrochinon, Resorcin, 4,4'-Dihydroxydiphenyl, Bis-(4-hydroxyphenyl)sulfid, Bis-(4-hydroxyphenyl)sulfon, Bis-(3,5-dimethyl-4-hydroxyphenyl)-methan, Bis-(3,5-dimethyl-4-hydroxyphenyl)-sulfon, 1,1-Bis-(3,5-dimethyl-4-hydroxyphenyl)-p / m-diisopropylbenzol, 1,1-Bis-(4-hydroxyphenyl)-1-phenyl-ethan, 1,1-Bis-(3,5-dimethyl-4-hydroxyphenyl)-cyclohexan, 1,1-Bis-(4-hydroxyphenyl)-3-methylcyclohexan, 1,1-Bis-(4-hydroxyphenyl)-3,3-dimethylcyclohexan, 1,1-Bis-(4-hydroxyphenyl)-4-methylcyclohexan. 1,1-Bis-(4-hydroxyphenyl)-cyclohexan, 1,1-Bis-(4-hydroxyphenyl)-3,3,5-trimethylcyclohexan, 2,2-Bis-(3,5-dichlor-4-hydroxyphenyl)-propan, 2,2-Bis-(3-methyl-4-hydroxyphenyl)-propan, 2,2-Bis-(3,5-dimethyl-4-hydroxyphenyl)-propan, 2,2-Bis-(4-hydroxyphenyl)-propan (d.h.Bisphenol A), 2,2-Bis-(3-chloro-4-hydroxyphenyl)-propane, 2,2-Bis-(3,5-dibromo-4-hydroxyphenyl)-propane, 2,4-Bis-(4-hydroxyphenyl)-2-methylbutane, 2,4-Bis-(3,5-dimethyl-4-hydroxyphenyl)-2-methylbutane, α,α'-Bis-(4-hydroxyphenyl)-o-diisopropylbenzene, α,α'-Bis-(4-hydroxyphenyl)-m-diisopropylbenzene (i.e., Bisphenol M), α,α'-Bis-(4-hydroxyphenyl)-p-diisopropylbenzene and indanbisphenol.

[0085] The described bisphenols can be produced by methods known to those skilled in the art, preferably from the corresponding phenols and ketones.

[0086] The polycarbonates used according to the invention can also be produced by known processes. Preferred processes for the production of polycarbonates include, for example, production from bisphenols with phosgene by the interfacial process, or from bisphenols with phosgene by the homogeneous-phase process, the so-called pyridine process, or from bisphenols with carbonic acid esters by the melt transesterification process. The aforementioned bisphenols and processes for their production are described, for example, in the monograph by H. Schnell, "Chemistry and Physics of Polycarbonates", Polymer Reviews, Volume 9, p.77-98, Interscience Publishers, New York, London, Sydney, 1964 and in US-A 3 028 635, in US-A 3 062 781, in US-A 2 999 835, in US-A 3 148 172, in US-A 2 991 273, in US-A 3 271 367, in US-A 4 982 014, in US-A 2 999 846, in DE-A 1 570 703, in DE-A 2 063 050, in DE-A 2 036 052, in DE-A 2 211 956, in DE-A 3 832 396, and in FR-A 1 561 518 as well as in the Japanese publications with the Registration numbers JP-A 62039 1986, JP-A 62040 1986 and JP-A 105550 1986.

[0087] In the production of polycarbonate, raw materials and additives with a low degree of impurities are preferably used. Particularly in production using the melt transesterification process, the bisphenols and carbonic acid derivatives used should be as free as possible from alkali and alkaline earth ions. Such pure raw materials can be obtained, for example, by recrystallizing, washing, or distilling the carbonic acid derivatives, especially carbonic acid esters, and the bisphenols.

[0088] Polycarbonates preferably used according to the invention preferably have a weight average of the molar mass M wThe molar mass is in the range of 10,000 to 200,000 g / mol, which can be determined by ultracentrifugation (see K. Schilling, Analytical Ultracentrifugation, Nanolytics GmbH, Dallgow, pages 1-15) or by light scattering measurement according to DIN EN ISO 16014-5:2012-10. The polycarbonates to be used preferably have a weight-average molar mass in the range of 12,000 to 80,000 g / mol, and particularly preferably a weight-average molar mass in the range of 20,000 to 35,000 g / mol.

[0089] The average molar mass of the polycarbonates preferably used according to the invention can preferably be adjusted in a known manner by an appropriate quantity of chain breakers. The chain breakers can be used individually or as a mixture of different chain breakers.

[0090] Preferred chain terminations are both monophenols and monocarboxylic acids. Preferred monophenols are phenol, p-chlorophenol, p-tert-butylphenol, cumylphenol, or 2,4,6-tribromophenol, as well as long-chain alkylphenols, in particular 4-(1,1,3,3-tetramethylbutyl)phenol or monoalkylphenols or dialkylphenols with a total of 8 to 20 carbon atoms in the alkyl substituents, in particular 3,5-di-tert-butylphenol, p-tert-octylphenol, p-dodecylphenol, 2-(3,5-dimethylheptyl)phenol, or 4-(3,5-dimethylheptyl)phenol. Preferred monocarboxylic acids are benzoic acid, alkylbenzoic acids, or halobenzoic acids.

[0091] Particularly favored chain terminators are phenol, p-tert-butylphenol, 4-(1,1,3,3-tetramethylbutyl)-phenol or cumylphenol.

[0092] The amount of chain terminators to be used is preferably in the range of 0.25 to 10 mol-%, based on the total amount of bisphenols used.

[0093] According to the invention, the polycarbonates preferably used can be branched in a known manner, preferably by the incorporation of trifunctional or more than trifunctional branchers. Preferred branchers are those with three or more than three phenolic groups or those with three or more than three carboxylic acid groups.

[0094] Besonders bevorzugte Verzweiger sind Phloroglucin, 4,6-Dimethyl-2,4,6-tri-(4-hydroxyphenyl)-hepten-2, 4,6-Dimethyl-2,4,6-tri-(4-hydroxyphenyl)-heptan, 1,3,5-Tri-(4-hydroxyphenyl)-benzol, 1,1,1-Tris-(4-hydroxyphenyl)-ethan, Tri-(4-hydroxyphenyl)-phenylmethan, 2,2-Bis-[4,4-bis-(4-hydroxyphenyl)-cyclohexyl]-propan, 2,4-Bis-(4-hydroxyphenyl-isopropyl)-phenol, 2,6-Bis-(2-hydroxy-5'-methyl-benzyl)-4-methylphenol, 2-(4-Hydroxyphenyl)-2-(2,4-dihydroxyphenyl)-propan, Hexa-(4-(4-hydroxyphenyl-isopropyl)-phenyl)-terephthalsäureester, Tetra-(4-hydroxyphenyl)-methan, Tetra-(4-(4-hydroxyphenyl-isopropyl)-phenoxy)-methan und 1,4-Bis-(4',4"-dihydroxytriphenyl)-methylbenzol, 2,4-Dihydroxybenzoesäure, Trimesinsäure, Cyanurchlorid, 3,3-Bis-(3-methyl-4-hydroxyphenyl)-2-oxo-2,3-dihydroindol, Trimesinsäuretrichlorid oder α,α',α"-Tris-(4-hydroxyphenol)-1,3,5-triisopropylbenzol.

[0095] Particularly favored branching compounds are 1,1,1-tris-(4-hydroxyphenyl)-ethane or 3,3-bis-(3-methyl-4-hydroxyphenyl)-2-oxo-2,3-dihydroindole.

[0096] The amount of branching agent to be used is preferably in the range of 0.05 mol% to 2 mol%, based on the moles of bisphenols used.

[0097] Preferably, in the case of polycarbonate production via the interfacial process, the branching agents are introduced with the bisphenols and chain terminators in an aqueous alkaline phase, or added dissolved in an organic solvent together with the carbonic acid derivatives. In the case of the transesterification process, the branching agents are preferably added together with the dihydroxyaromatics or bisphenols.

[0098] Preferably used catalysts in the production of polycarbonates according to the invention by the melt transesterification process are ammonium salts and phosphonium salts, as described, for example, in US-A 3 442 864, JP-A-14742172, US-A 5 399 659 or DE-A 19 539 290.

[0099] In a preferred embodiment, copolycarbonates can also be used. Copolycarbonates within the meaning of the invention are, in particular, polydiorganosiloxane-polycarbonate block copolymers whose weight average molar mass M wThe molecular weight is preferably in the range of 10,000 to 200,000 g / mol, particularly preferably in the range of 20,000 to 80,000 g / mol, determined by gel chromatography according to DIN EN ISO 16014-5:2012-10 after prior calibration by light scattering measurement or ultracentrifugation. The content of aromatic carbonate structural units in the polydiorganosiloxane-polycarbonate block copolymers is preferably in the range of 75 to 97.5 wt.%, particularly preferably in the range of 85 to 97 wt.%. The content of polydiorganosiloxane structural units in the polydiorganosiloxane-polycarbonate block copolymers is preferably in the range of 25 to 2.5 wt.%, particularly preferably in the range of 15 to 3 wt.%. The polydiorganosiloxane-polycarbonate block copolymers can preferably be prepared starting from α,ω-bishydroxyaryloxy end-group-containing polydiorganosiloxanes with a medium degree of polymerization P n in the range of 5 to 100, particularly preferably with a medium degree of polymerization P nin the range of 20 to 80.

[0100] Particularly preferred polycarbonates are the homopolycarbonate based on bisphenol A, the homopolycarbonate based on 1,1-bis-(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, and the copolycarbonates based on the two monomers bisphenol A and 1,1-bis-(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane (= bisphenol TMC). Polycarbonates preferred according to the invention are available, for example, under the brand name Makrolon® from Covestro Deutschland AG, Leverkusen.

[0101] In one embodiment, conventional additives, in particular mold release agents, can be added to the polycarbonates to be used in the melt or applied to the surface. Preferably, the polycarbonates to be used already contain mold release agents before subsequent compounding with the other components, where compounding (from the English: compound = "mixture") is a term from plastics engineering that is synonymous with plastics processing and describes the refinement process of plastics by adding aggregates (fillers, additives, etc.) to specifically optimize the property profiles.Compounding preferably takes place in extruders, particularly preferably in co-rotating twin-screw extruders, counter-rotating twin-screw extruders, planetary roller extruders or co-kneaders and includes the process operations of conveying, melting, dispersing, mixing, degassing and pressure build-up.

[0102] In a preferred embodiment, blends of polycarbonate and polyalkylene terephthalates, which are also offered by Covestro Deutschland AG under the brand name Makroblend®, can also be used. Preferably, these are PC-PET blends, PC-PBT blends, or PC-PCT-G blends, where PC stands for polycarbonate, PET for polyethylene terephthalate, PBT for polybutylene terephthalate, and PCT for polycyclohexylenedimethyl terephthalate.

[0103] According to the invention, food contact materials, preferably injection-molded food contact materials, are therefore preferred, with a color difference ΔE <20 from the L*a*b* coordinates to a color number starting with “1” of the RAL color chart according to the color model according to EN ISO 11664-4, as determined according to DIN 5033 (1979), based on polymer compositions containing at least one polycarbonate and a colorant of at least one yellow methine dye or at least one yellow quinophthalone dye and at least one EO / PO block copolymer with a central propylene oxide unit between two ethylene oxide units and a molar mass determined from the OH number to be determined according to DIN / ISO 4629, in the range of 5500 to 7500 g / mol, a mass fraction of ethylene oxide units in the range of 45 to 55 wt.% and a flocculation point to be determined according to EN 1890 method B in the range of 70°C to 85°C.

[0104] Preferably, in these polycarbonate-based polymer compositions, 0.01 to 5 mass parts, particularly preferably 0.01 to 3 mass parts, of the methine dye or the quinophthalone dye are used per 100 mass parts of polycarbonate. EO / PO block copolymer

[0105] For clarification, it should be noted that in the case of molecularly heterogeneous substances, the molecular weights specified within the scope of the present invention represent number-average values. The molecular weights or number-average molecular weights M nWhen identifiable functional end groups such as hydroxy, NCO, amino, or acid groups are present, the molecular weights are determined by end group determination via titration to determine the OH number, NCO number, amine number, or acid number, respectively. For compounds to which end group determination is not applicable, the number-mean molecular weight is determined by gel permeation chromatography against a polystyrene standard. The molecular weights given for polyamines are number-mean values ​​M determined by ebullioscopic analysis. n The free NCO content of the polyisocyanates used to produce the poloxamers or EO / PO block copolymers according to the invention, as well as the reaction progress of the NCO additions, is determined according to EN ISO 9369 by reaction with butylamine and subsequent titration of the excess amine. These methods are also described in Saul Patai, "The Chemistry of Cyanates and their Thioderivates", Part 1, Chapter 5, 1977.

[0106] According to the invention, an ethylene oxide-propylene oxide block copolymer with a central propylene oxide unit between two ethylene oxide units and the characteristics of a molar mass, determined from the OH number to be determined according to DIN / ISO 4629, in the range of 5500 to 7500 g / mol, a mass fraction of ethylene oxide units in the range of 45 to 55 wt.% and a flocculation point to be determined according to EN 1890 method B in the range of 70°C to 85°C is used to produce the colorants.

[0107] In a preferred embodiment, the proportion of the ethylene oxide-propylene oxide block copolymer (EO / PO block copolymer) in the colorant to be used according to the invention, based on the dry colorant, is 1 to 3 wt.%.

[0108] Poloxamers are known to those skilled in the art, for example, from EP 1 763 673 B1. These contain polyethylene oxide units (PEO) and polypropylene oxide units (PPO) and can be represented in a simplified form by the following formula (XI): (PEO)a -(PPO) b -(PEO) c (XI)

[0109] According to the nomenclature in EP 1 763 673 B1, EO / PO block copolymers with mass fractions in the range of 45 to 55 wt.% are preferably used according to the invention, wherein the ethylene oxide and the propylene oxide units have the statistical distribution shown in Table 2 with the respective weight percent mass fraction of ethylene oxide indicated: Table 2 Weight % a b c EO 37 56 37 50 30 56 30 45 45 56 45 55 37 45 37 55 37 65 37 46

[0110] The invention therefore preferably relates to food contact materials with a color difference ΔE <20 from the L*a*b* coordinates to a color number starting with “1” of the RAL color chart according to the color model according to EN ISO 11664-4, as determined according to DIN 5033 (1979), based on compositions containing at least one polyester or polystyrene and a colorant consisting of at least one yellow methine dye or at least one yellow quinophthalone dye and at least one ethylene oxide-propylene oxide block copolymer (EO / PO block copolymer) represented by formula (XI) (PEO) a -(PPO) b -(PEO) c (XI) with a central propylene oxide unit between two ethylene oxide units, a molar mass determined from the OH number to be determined according to DIN / ISO 4629, in the range of 5500 to 7500 g / mol and a flocculation point to be determined according to EN 1890 method B in the range of 70°C to 85°C, wherein at a mass fraction of ethylene oxide units of 50 wt.% a and c stand for 37 and b for 56, or, with a mass fraction of ethylene oxide units of 45 wt.%, a and c stand for 30 and b for 56, or, with a mass fraction of ethylene oxide units of 55 wt.%, a and c stand for 45 and b for 56, or, with a mass fraction of ethylene oxide units of 55 wt.%, a and c stand for 37 and b for 45, or, with a mass fraction of ethylene oxide units of 46 wt.%, a and c stand for 37 and b for 65.

[0111] Particularly preferred according to the invention is the EO / PO block copolymer Genapol® 10500 from Clariant International Ltd, Muttenz (CH), with an OH number to be determined according to DIN / ISO 4629 and a molar mass of approximately 6000 g / mol (see US 10,407,616 or DE 10 2016 210 164 A1), a mass fraction of ethylene oxide units of 50 wt.% and a flocculation point of 78°C determined according to EN 1890 method B. Preferred uses

[0112] Preferably, the present invention relates to the use of at least one ethylene oxide-propylene oxide block copolymer (EO / PO block copolymer) with a central propylene oxide unit between two ethylene oxide units, a molar mass determined from the OH number to be determined according to DIN / ISO 4629, in the range of 5500 to 7500 g / mol, a mass fraction of ethylene oxide units in the range of 45 to 55 wt.% and a flocculation point to be determined according to EN 1890 method B in the range of 70°C to 85°C with at least one yellow methine dye or at least one yellow quinophthalone dye as a colorant for the production of polyester or polystyrene-based food contact materials with a color difference ΔE <20 from the L*a*b* coordinates to a color number starting with “1” of the RAL color chart according to the color model according to EN ISO 11664-4, to be determined according to DIN 5033 (1979).

[0113] For clarification, it should be noted that the scope of the claimed use(s) includes all the general definitions and parameters listed above, or those mentioned in preferred areas, in any combination. This also applies to the combination of quantity specifications for the individual components.

[0114] Preferably, these are polyesters or polystyrene processed into food contact materials by injection molding, extrusion, or blow molding. For this application, polystyrene preferably also includes styrene copolymers selectable from styrene-butadiene copolymers, acrylonitrile-butadiene-styrene terpolymers, styrene-acrylonitrile copolymers, or blends in the form of ABS+PC or ABS+PA.

[0115] Preferably, food contact materials made from polyester or polystyrene that are available within the scope of the invention also have a color difference ΔE <20 from the L*a*b* coordinates to a color number starting with “1” of the RAL color chart according to the color model according to EN ISO 11664-4, which is to be determined according to DIN 5033 (1979), wherein it is at least one color number of the series RAL 1003, RAL 1016, RAL 1018, RAL 1026, or RAL 1028, in particular RAL 1016 or RAL 1018.

[0116] Preferably, in this application, the color difference ΔE <10, particularly preferably ΔE <5, from the L*a*b* coordinates to a color number starting with “1” of the RAL color chart according to the color model according to EN ISO 11664-4, which is to be determined according to DIN 5033 (1979).

[0117] Preferably, in the context of the uses according to the invention, titanium dioxide is used as a white pigment in the colorant in order to achieve a high opacity in accordance with DIN 55986.

[0118] According to the invention, Solvent Yellow 93 [CAS No. 4702-90-3], also known as Macrolex® Yellow 3G or 6-(2,5-Dimethylbenzoyl)-3-hydroxy-2-(3-hydroxy-2-quinolinyl)-1H-inden-1-one or Macrolex® Yellow E2R [CAS No. 198625-33-1], both available from LANXESS Deutschland GmbH, Cologne, is particularly preferred for use in the invention. Preferred methods

[0119] Preferably, the present invention relates to a method for achieving a narrow particle size distribution or a span value of 2.25 + / - 1 of the colorant to be used within the scope of this invention, comprising at least one yellow methine dye or at least one yellow quinophthalone dye and at least one ethylene oxide-propylene oxide block copolymer (EO / PO block copolymer) with a central propylene oxide unit between two ethylene oxide units, a molar mass determined from the OH number to be determined according to DIN / ISO 4629, in the range of 5500 to 7500 g / mol, and a mass fraction of ethylene oxide units in the range of 45 to 55 wt.-% and a flocculation point to be determined according to EN 1890 method B in the range of 70°C to 85°C, by mixing the components, preferably at 23 + / - 2°C, wherein 20 to 100 parts of the yellow methine dye or the yellow quinophthalone dye and 15 to 81 parts of deionized water are used to 1 part of the EO / PO block copolymer and, after a stirring time of up to 60 min, preferably up to 15 min, the dye obtained as an aqueous dye dispersion is milled using a mill for a period of up to 15 minutes.

[0120] The invention further relates to a method for the production of food contact materials with a color difference ΔE <20 from the L*a*b* coordinates to a color number beginning with “1” of the RAL color chart according to the color model according to EN ISO 11664-4, as determined according to DIN 5033 (1979), by combining a colorant consisting of at least one yellow methine dye or at least one yellow quinophthalone dye and at least one ethylene oxide-propylene oxide block copolymer (EO / PO block copolymer) with a central propylene oxide unit between two ethylene oxide units, a molar mass determined from the OH number to be determined according to DIN / ISO 4629, in the range of 5500 to 7500 g / mol, a mass fraction of ethylene oxide units in the range of 45 to 55 wt.% and a flocculation point to be determined according to EN 1890 method B in the range of 70°C to 85°C with at least one polyester or Polystyrene is processed by injection molding, extrusion or blow molding.

[0121] According to the invention, the term polystyrene also includes styrene copolymers. In a preferred embodiment, a styrene copolymer is selected as the polystyrene or styrene-based plastic in the processes according to the invention, from styrene-butadiene copolymers, acrylonitrile-butadiene-styrene terpolymers, styrene-acrylonitrile copolymers, or a blend in the form of ABS+PC or ABS+PA.

[0122] Preferably, in accordance with the methods according to the invention, food contact materials based on polyester or polystyrene are also produced with a color difference ΔE <20 from the L*a*b* coordinates to a color number starting with “1” of the RAL color chart according to the color model according to EN ISO 11664-4, which is to be determined according to DIN 5033 (1979), wherein the color number corresponds to RAL 1003, RAL 1016, RAL 1018, RAL 1026 or RAL 1028, in particular RAL 1016 or RAL 1018.

[0123] Preferably, titanium dioxide is used as a white pigment in the colorant in accordance with the inventive process in order to achieve a high opacity in accordance with DIN 55986.

[0124] Solvent Yellow 93 [CAS No. 4702-90-3], also known as Macrolex® Yellow 3G or 6-(2,5-Dimethylbenzoyl)-3-hydroxy-2-(3-hydroxy-2-quinolinyl)-1 H-inden-1-one or Macrolex® Yellow E2R [CAS No. 198625-33-1], both available from LANXESS Deutschland GmbH, Cologne, is particularly preferred in the processes according to the invention.

[0125] For the avoidance of doubt, it should be noted that the scope of this claimed method includes all the general definitions and parameters listed above, or those mentioned in preferred areas, in any combination. This also applies to the combination of quantities specified for the individual components. Preferred food supplies

[0126] In one embodiment, the invention relates to at least one ethylene oxide-propylene oxide block copolymer with a central propylene oxide unit between two ethylene oxide units, a molar mass determined from the OH number to be determined according to DIN / ISO 4629 in the range of 5500 to 7500 g / mol, a mass fraction of ethylene oxide units in the range of 45 to 55 wt.% and a flocculation point to be determined according to EN 1890 method B in the range of 70°C to 85°C with at least one yellow methine dye or at least one yellow quinophthalone dye as a colorant for polyester or polystyrene-based food packaging, bottles or tableware with a color difference ΔE <20 from the L*a*b* coordinates to a color number starting with “1” of the RAL color chart according to the color model according to EN ISO 11664-4, to be determined according to DIN 5033 (1979).

[0127] Preferably, the invention relates to food packaging, bottles, or tableware with a color difference ΔE <20 from the L*a*b* coordinates to a color number beginning with "1" of the RAL color chart according to the color model according to EN ISO 11664-4, as determined according to DIN 5033 (1979), by combining a colorant consisting of at least one yellow methine dye or at least one yellow quinophthalone dye and at least one ethylene oxide-propylene oxide block copolymer (EO / PO block copolymer) with a central propylene oxide unit between two ethylene oxide units, a molar mass determined from the OH number to be determined according to DIN / ISO 4629 in the range of 5500 to 7500 g / mol, a mass fraction of ethylene oxide units in the range of 45 to 55 wt.%, and a flocculation point to be determined according to EN 1890 method B in the range of 70°C to 85°C with at least one polyester or styrene The plastic is processed by injection molding, extrusion, or blow molding. Preferred polyesters are Poly-C2-C.10 alkylene terephthalates or polycarbonate.

[0128] In a preferred embodiment, a styrene copolymer is selected from styrene-butadiene copolymers, acrylonitrile-butadiene-styrene terpolymers, styrene-acrylonitrile copolymers, or a blend in the form of ABS+PC or ABS+PA, also in the case of food packaging, bottles or tableware, as a polystyrene or styrene-based plastic.

[0129] Preferably, polyester or polystyrene-based food packaging, bottles, or tableware has a color difference ΔE < 20 from the L*a*b* coordinates of a color number beginning with "1" in the RAL color chart according to the color model according to EN ISO 11664-4, as determined according to DIN 5033 (1979), wherein the color number is at least one of the series RAL 1003, RAL 1016, RAL 1018, RAL 1026, or RAL 1028. Particularly preferably, the polyester or polystyrene-based food packaging, bottles, or tableware has a color difference ΔE < 20 from the L*a*b* coordinates of RAL 1016 and RAL 1018 according to the color model according to EN ISO 11664-4, as determined according to DIN 5033 (1979).

[0130] Preferably, the color difference ΔE <10, particularly preferably ΔE <5, from the L*a*b* coordinates to a color number starting with “1” of the RAL color chart according to the color model according to EN ISO 11664-4, which is to be determined according to DIN 5033 (1979).

[0131] Preferably, titanium dioxide is used as a white pigment in the colorant in the preferred food contact materials in order to achieve a high opacity in accordance with DIN 55986.

[0132] According to the invention, Solvent Yellow 93 [CAS No. 4702-90-3], also known as Macrolex® Yellow 3G or 6-(2,5-Dimethylbenzoyl)-3-hydroxy-2-(3-hydroxy-2-quinolinyl)-1 H-inden-1-one or Macrolex® Yellow E2R [CAS No. 198625-33-1], both available from LANXESS Deutschland GmbH, Cologne, is particularly preferred for use in further products.

[0133] For clarification, it should be noted that the scope of these preferred food application applications includes all the general definitions and parameters listed above, or those mentioned in preferred areas, in any combination. This also applies to the combination of quantities for the individual components. The following examples are intended to illustrate the present invention without limiting it. Examples: Solvent Yellow 179 (according to the invention)

[0134] 91.7 parts of the EO / PO block copolymer Genapol® 10500, with a mean molar mass (calculated from an OH number of approximately 6500 g / mol as determined according to DIN / ISO 4629), a mass fraction of ethylene oxide units of 50 wt.%, and a flocculation point of 78°C according to EN 1890 Method B, were mixed with 551.4 parts of Solvent Yellow 179 at room temperature with 356.9 parts deionized water under vigorous stirring. The solids content of the dye was 99.8%. The mass of the copolymer, based on the dry dye, was 3%. After 15 minutes of stirring, this 55 wt.% dye dispersion was milled in a bead mill for 15 minutes in a single pass. The dye obtained in this way exhibited a distribution width or span value of 2.25 with respect to a mean particle size (see [reference]). Fig. 1 accompanied.

[0135] The pH of the colorant, which was present as a dispersion, was adjusted to approximately 7 using NaOH. At this point, the color particles had an average diameter of approximately 4 µm. This dispersion was then spray-dried to a microgranulate in a pressure nozzle tower at an inlet temperature of 205 °C and an outlet temperature of 88 °C, while the sample was continuously stirred. The resulting colorant was free-flowing and low in dust, with an average particle size of approximately 180 µm and a residual moisture content of approximately 0.1%.

[0136] The resulting colorant was suitable for coloring plastics in the color RAL 1016 or with a similar RAL color with a color difference ΔE <20 from the L*a*b* coordinates to a color number starting with “1” of the RAL color chart according to the color model according to EN ISO 11664-4, to be determined according to DIN 5033 (1979). Solvent Yellow 179 (not according to the invention)

[0137] According to EP 0 488 933 B1, 91.7 parts of the EO / PO block copolymer Aduxol® VP-5342, with a mean molar mass (calculated from an OH number of approximately 6500 g / mol as determined according to DIN / ISO 4629), a mass fraction of ethylene oxide units of 50 wt.%, and a flocculation point of approximately 58 °C according to EN 1890 Method B, were mixed with 551.4 parts of Solvent Yellow 179 at room temperature with 356.9 parts deionized water under vigorous stirring. The solids content of the dye was 99.8%. The mass of the copolymer, based on the dry dye, was 3%. After 15 minutes of stirring, this 55 wt.% dye dispersion was milled in a bead mill for 15 minutes in a single pass. The dye dispersion obtained in this way had a distribution width or span value of 2.4 with respect to a mean particle size (see below). Fig. 1 accompanied.

[0138] The pH of the dispersion was adjusted to approximately 7 using NaOH. The dispersion then had a mean particle diameter of approximately 3 µm. This dispersion was subsequently spray-dried to a microgranulate in a pressure nozzle tower at an inlet temperature of 205 °C and an outlet temperature of 88 °C, while the feed was continuously stirred. The resulting colorant had the color RAL 2007, was poorly free-flowing, and exhibited significant dust generation. Its mean particle size was 70 µm, and the residual moisture content was 0.5%. Table 3: Starting materials: Pocan®B 1300 Linear polybutylene terephthalate (Lanxess Deutschland GmbH, Cologne, Germany) with an intrinsic viscosity of 93 cm³ / g (measured in phenol: 1,2-dichlorobenzene = 1:1 at 25°C) Solvent Yellow 179 LANXESS Deutschland GmbH, Cologne Genapol® 10500 Clariant Products (Germany) GmbH, Frankfurt am Main Aduxol® VP-5342 Schärer & Schläpfer AG chemical factory, Rothrist (CH)

[0139] Fig. Figure 1 shows that in the case of Solvent Yellow 179 and Genapol® 10500, the desired grind was achieved after 15 minutes, as the width of the distribution, measured on the chip, was reduced by 10% and at the same time the sizing was reduced by at least 50%.

[0140] In contrast to Aduxol® VP-5342 / Solvent Yellow 179 based injection-molded polyester or PBT test specimens, Genapol® 10500 / Solvent Yellow 179 based injection-molded polyester or PBT test specimens showed no specks and corresponded to a white brightening of RAL1016 because titanium dioxide was added as a white pigment to achieve a high opacity in accordance with DIN 55986. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] EP-A 488 933 [0004, 0010] EC 1935 / 2004

[0006] EC 2023 / 2006

[0006] EP 10 / 2011

[0006] DE 10 2017 216 194 A1 [0007, 0010] EP-A 0 488 933 [0023, 0039] DE AS 1 261 105

[0037] EP 83 553 A1

[0037] DE 100 31 567 A1

[0037] US-A 4 198 264

[0051] DE-A 44 01 055

[0072] US-A 3 028 635

[0086] US-A 3 062 781

[0086] US-A 2 999 835

[0086] US-A 3 148 172

[0086] US-A 2 991 273

[0086] US-A 3 271 367

[0086] US-A 4 982 014

[0086] US-A 2 999 846

[0086] DE-A 1 570 703

[0086] DE-A 2 063 050

[0086] DE-A 2 036 052

[0086] DE-A 2 211 956

[0086] DE-A 3 832 396

[0086] FR-A 1 561 518

[0086] JP-A 62039 1986

[0086] JP-A 62040 1986

[0086] JP-A 105550 1986

[0086] US-A 3 442 864

[0098] JP-A-14742172

[0098] US-A 5 399 659

[0098] DE-A 19 539 290

[0098] EP 1 763 673 B1 [0108, 0109] US 10,407,616

[0111] DE 10 2016 210 164 A1

[0111] EP 0 488 933 B1

[0137] Cited non-patent literature

[0000] https: / / www.bmel.de / DE / themen / verbraucherschutz / lebensmittelsicherheit / lebensmittelverpackungen / lebensmittelverpackungen_node.html

[0006] DIN 5033 (1979 [0013, 0015] EN ISO 11664-4

[0015] DIN / ISO 4629

[0015] EN 1890

[0015] https: / / de.wikipedia.org / wiki / Lab-Farbraum

[0021] D. Monella et al, “Comparative studies on particle size analysis”, Chemie Ingenieur Technik (72), 3 / 2000, pages 273 - 276

[0026] https: / / de.wikipedia.org / wiki / Polystyrol

[0061] D. Bender, H. Gausepohl, D. Braun, R. Gellert: Polystyrene. Hanser Verlag 1995; ISBN 3-446-18004-4; p.

[0061] Plastics Handbook, Vol. VIII, pp. 695-743, Karl Hanser Verlag, Munich 1973

[0074] Monographie H. Schnell, „Chemistry and Physics of Polycarbonates“, Polymer Reviews, Band 9, S. 77-98, Interscience Publishers, New York, London, Sidney, 1964

[0086]

Claims

Food contact materials with a color difference ΔE <20 from the L*a*b* coordinates to a color number starting with "1" of the RAL color chart according to the color model according to EN ISO 11664-4, as determined according to DIN 5033 (1979), based on compositions containing at least one polyester or polystyrene and a colorant consisting of at least one yellow methine dye or at least one yellow quinophthalone dye and at least one ethylene oxide-propylene oxide block copolymer with a central propylene oxide unit between two ethylene oxide units, a molar mass determined from the OH number to be determined according to DIN / ISO 4629, in the range of 5500 to 7500 g / mol, a mass fraction of ethylene oxide units in the range of 45 to 55 wt.% and a flocculation point to be determined according to EN 1890 method B in the range of 70°C to 85°C. Food contact materials according to claim 1, characterized in that 0.01 to 5 mass parts of the methine dye or the quinophthalone dye are used per 100 mass parts of polyester or polystyrene. Food contact materials according to claim 1, characterized in that 0.01 to 3 mass parts of methine dye or quinophthalone dye are used per 100 mass parts of polyester or polystyrene. Food contact materials according to one or more of claims 1 to 3, characterized in that at least one C2-C10 polyalkylene terephthalate or at least one polycarbonate is used as the polyester. Food contact materials according to one or more of claims 1 to 3, characterized in that polybutylene terephthalate is used as the polyester. Food contact materials according to one or more of claims 1 to 5, characterized in that 2-[[4-[2-(4-cyclohexylphenoxy)ethyl-ethylamino]-2-methylphenyl]methylidene]propanenitrile or Solvent Yellow 179 or 4,4'-Methylidenebis(5-methyl-2-phenyl-2,4-dihydro-3H-pyrazol-3-one) or Solvent Yellow 93 is used as the yellow methine dye. Food contact materials according to one or more of claims 1 to 5, characterized in that 2-[[4-[2-(4-cyclohexylphenoxy)ethyl-ethylamino]-2-methylphenyl]methylidene]propanenitrile or 4,4'-methylidenebis(5-methyl-2-phenyl-2,4-dihydro-3H-pyrazol-3-one) is used as the yellow quinophthalone dye. Food contact materials according to one or more of claims 1 to 7, characterized in that the ethylene oxide-propylene oxide block copolymer is represented by formula (XI) (PEO)a-(PPO)b-(PEO)c(XI) with a central propylene oxide unit between two ethylene oxide units, wherein, at a mass fraction of ethylene oxide units of 50 wt%, a and c represent 37 and b represents 56, or at a mass fraction of ethylene oxide units of 45 wt%, a and c represent 30 and b represents 56, or at a mass fraction of ethylene oxide units of 55 wt%, a and c represent 45 and b represents 56, or at a mass fraction of ethylene oxide units of 55 wt%, a and c represent 37 and b represents 45, or at a mass fraction of ethylene oxide units of 46 wt%, a and c represent 37 and b represents 65. Food contact materials according to one or more of claims 1 to 8, characterized in that the colour number corresponds to RAL 1003, RAL 1016, RAL 1018, RAL 1026 or RAL 1028. Food contact materials according to one or more of claims 1 to 8, characterized in that the color number corresponds to RAL1016 or RAL1018. Food contact materials according to one or more of claims 1 to 10, characterized in that the colorant is a spray granulate.

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