3d-printed products

Abstract

To provide 3D-printed products.SOLUTION: The present invention relates to urethane-acrylate-resin-based 3D-printed products having a colour distance ΔE of less than 20 from the L*a*b* coordinates for a colour number, beginning with "3", of the RAL colour chart, comprising at least one red perinone dye to be selected from 8,9,10,11-tetrachloro-12H-phthaloperin-12-one and / or 14H-benz[4,5]isoquino[2,1-a]perimidin-14-one dissolved therein, to the use of the red perinone dyes for producing 3D-printed products having a colour distance ΔE of less than 20 from the L*a*b* coordinates for a colour number, beginning with "3", of the RAL colour chart by photopolymerization, and to a method for increasing the lightfastness and the colouristic properties of photopolymerizable urethane-acrylate-resin-based compositions and 3D-printed products based thereon by means of at least one red perinone dye to be selected from 8,9,10,11-tetrachloro-12H-phthaloperin-12-one and / or 14H-benz[4,5]isoquino[2,1-a]perimidin-14-one dissolved therein.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a urethane acrylate resin-based coating composition comprising at least one red perinone dye selected from 8,9,10,11-tetrachloro-12H-phthaloperin-12-one and / or 14H-benz[4,5]isoquino[2,1-a]perimidin-14-one, and a coating composition for the RAL color chart color numbers beginning with "3". * a * b * 3D-printed products with a color difference ΔE of less than 20 from the coordinates, by photopolymerization, L for color numbers on the RAL color chart starting with "3" * a * b * The present invention relates to the use of said red perinone dye for producing 3D-printed products having a color difference ΔE of less than 20 from the coordinates, and to a method for improving the lightfastness and color properties of photopolymerizable urethane acrylate resin-based compositions and 3D-printed products based thereon by means of at least one red perinone dye selected from 8,9,10,11-tetrachloro-12H-phthaloperin-12-one and / or 14H-benz[4,5]isoquino[2,1-a]perimidin-14-one dissolved therein. [Background technology]

[0002] Color masterbatches contain colorants in dispersed or dissolved form. The color or hue of a plastic product can serve, among other things, as a distinctive feature for a company or a particular product, as a protective ingredient, as a safety indicator, or as a functional additive. Amorphous plastics, such as polystyrene, polycarbonate, polymethylmethacrylate, and the like, require the use of polymer-soluble dyes to maintain their transparency. In contrast to pigments, colorants used for 3D printing by photopolymerization are preferably soluble in the plastic resin being processed and not present in a colloidal form.

[0003] 3D printing is a method of additive manufacturing. It refers to the process of layer-by-layer construction of components by depositing raw materials based on digital 3D design data. Therefore, for the purposes of this invention, "3D printing" is used as a synonym for "additive manufacturing." However, "additive manufacturing" better describes the fact that it is a manufacturing process that is significantly different from conventional ablative fabrication methods. For example, instead of grinding a workpiece from a solid, additive manufacturing builds up components layer-by-layer from raw materials that are available, for example, in powder form. Various metals, plastics, and composite materials can be used as raw materials.

[0004] 3D printing has recently become established as a manufacturing method in various sectors and industries. In the construction of demonstration and functional prototypes, small- and medium-scale production runs, and even in mass production, this process is demonstrating advantages unattainable by other conventional methods. For example, it can significantly accelerate product development and launch, achieving product individualization or functional integration in less time and often at lower cost. For major original equipment manufacturers (OEMs) from a wide variety of industries, additive manufacturing through 3D printing thus offers market differentiation opportunities in terms of new customer benefits, potential cost reductions, and sustainability goals. In 3D printing, 3D-printed products are created by selectively introducing suitable raw materials into the printing technology in an automated process, layer by layer, to form the corresponding desired shape. Original equipment manufacturers (OEMs) are the creators of components or products, but they do not directly sell these creations to the retail market. In the automotive industry, the term "OEM" is used synonymously with vehicle manufacturer.

[0005] There are various 3D printing processes for plastics, including those that produce plastics by curing only during printing. One embodiment is photopolymerization-based 3D printing, in which a liquid photocurable resin is applied layer-by-layer and light is used to initiate the photocuring process / polymerization, i.e., photoinduced curing. Selective layer-by-layer curing of the liquid resin is achieved by spatially limited, precisely defined, and computer-controlled exposure of the resin to light within a suitable spectral range to initiate the photopolymerization process. UV light is particularly preferred, but visible or infrared light is also suitable. The photopolymerization-based 3D printing process of the present invention is preferably stereolithography (SLA) or digital light processing (DLP). In both 3D printing variants, the corresponding equipment consists of a light source, which can be used to expose to light from above or below (so-called "top-down" or "bottom-up" printing); a resin tank; and a platform on which the layer-by-layer curing of the plastic resin used for 3D printing is carried out. In SLA 3D printing, the surface to be cured is exposed to light point-by-point by scanning with a laser beam, while in DLP processes, the entire surface to be exposed is exposed using, inter alia, an LCD (liquid crystal display) panel. In a typical printing operation, the printing platform is immersed in resin in a resin tank while an exposure program is carried out to form layers. By repeating the layer formation, the 3D-printed product is finally obtained. In the SLA process, a stereolithography printer uses a laser to form the 3D-printed product. For this purpose, a plastic solution that hardens under UV light is applied. The corresponding 3D printers are called SLA 3D printers or DLP 3D printers.A comparison of the two technologies, as well as suppliers of comparable 3D printers, can be found in the following review: 3Dnatives, Regina P., 8 April 2021 (Non-Patent Document 1).

[0006] Patent Document 1 describes a golf ball comprising a core, at least one layer surrounding the core, and a fluorescent pigment coloring layer applied to the surface of the outermost layer of the shell. The outermost layer may be made of a thermoplastic polyurethane material (Pandex® T8290 or Pandex® T8283). In one embodiment, Solvent Red 149 (Sumiplast® Red HFG) and Solvent Red 150 (Sumiplast® HF 4G) are used as red fluorescent anthraquinone dyes in the coloring layer applied to the outermost layer. The ball has an appearance characterized by excellent spin performance and durability, excellent visibility, style, and luxury, as well as excellent weather resistance.

[0007] Patent Document 2 discloses a colored, curable composition for use in additive manufacturing processes, which comprises a curable resin composition containing a radiation-curable component, a photoinitiator, and a dye composition containing Dye D1 and Dye D2 (wherein Dye D1 has a light absorption maximum in the wavelength range of 400 to 530 nm, and Dye D2 has a light absorption maximum in the wavelength range of 540 to 650 nm). As an example, two anthraquinone dyes are used: CI Solvent Red 111 (CAS No. 82-38-2) (Dye 1) and CI Solvent Violet 13 (CAS No. 81-48-1) (Dye 2). It also describes an S30 3D printer (Rapid Shape GmbH, Heimsheim, Germany), which uses LED light having a wavelength of 405 nm at 50 mW / cm. 2 It is applied for 11 seconds per layer at an intensity of 1.

[0008] In addition to the advantages of color performance during and immediately after the process for producing 3D-printed products by photopolymerization, the in-use performance of such 3D-printed products must also be considered. Colorants used in the aforementioned prior art have proven undesirable during the 3D fabrication process due to color changes that occur as a result of exposure to the light necessary for photopolymerization. However, light sensitivity / fastness is a quality attribute for colored 3D-printed products produced by photopolymerization-based 3D printing. Fading or discoloration, even browning, of 3D-printed products produced by photopolymerization-based 3D printing should be avoided to the greatest extent possible.

[0009] Furthermore, upon photopolymerization, preferably by SLA or DLP processes, colorants intended for 3D printing should maintain their advantageous performance characteristics and should not weaken or even stop the curing / polymerization of the 3D-printed product. For the purposes of this invention, advantageous performance characteristics of dyes defined for 3D printing in this invention are the establishment of a desired / defined hue and the establishment of a highly pure and vivid color. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] US Patent Application Publication No. 2011 / 0070976A1 [Patent Document 2] US Patent Application Publication No. 2019 / 0201171A1 [Non-patent literature]

[0011] [Non-Patent Document 1] https: / / www.3dnatives.com / de / sla-vs-dlp-3d-druck-080420211 / Summary of the Invention [Problem to be solved by the invention]

[0012] The problem that the present invention aims to solve is therefore to provide red dyes for 3D printing by photopolymerization, in particular by SLA or DLP methods, which dyes, due to their high solubility in the plastics to be processed, make it possible to establish a defined red hue and which retain their lightfastness during the printing process as well as their color properties compared to Solvent Red 111 as used in US Patent Application Publication No. 2019 / 0201171 A1, which in the context of the present invention is described as improved lightfastness and color properties as measured in accordance with DIN EN ISO 4892-2. [Means for solving the problem]

[0013] Lightfastness evaluation method To measure the lightfastness of dyes for photopolymerization-based 3D printing, rectangular specimens of the colored resin were prepared with dimensions of 60 mm length, 40 mm width, and 2 mm height, and a dye concentration of 0.02% in the resin. The specimens were then exposed to a light source (xenon lamp) in the as-printed state for 95-100 hours using a Xenotest Beta+ instrument (Atlas Material Testing Technology GmbH, Linsengericht-Altenhasslau, Germany) according to DIN EN ISO 4892-2. Lightfastness was assessed colorimetrically by recording the transmission spectra of the exposed specimens using an X-Rite Ci7800 integrating sphere spectrophotometer (X-Rite GmbH, Planegg-Martinsried, Germany) with the following settings: optical geometry = d / 8°; spectral interval = 10 nm; spectral range = 360-750 nm. The manufacturer's software for the integrating sphere spectrophotometer then calculates the following from the resulting transmission spectrum: Illuminant / photometer = D65 / 10°; color space = L * a * b* C * The colorimetric data is calculated using the h° setting. The standard for evaluating lightfastness is L * a * b * C * This is the color difference ΔE between an exposed specimen and the corresponding unexposed specimen in the h° color space. The greater the color difference, the greater the change in color impression caused by exposure to light, i.e., the poorer the lightfastness. ΔE is classified based on a comparison with so-called non-inventive examples of dyes of similar hues, which, according to manufacturer's data, are generally rated as having good lightfastness in other applications, especially in the case of bulk discoloration of plastics.

[0014] Method for assessing the stability of color characteristics For the purposes of this invention, the absorption spectra of the studied pigmented resins before and after photoinduced curing are compared in order to determine the changes in the spectral performance that determines the color properties of the dye.

[0015] To do this, the colored resins prepared as described above in the "Method for Evaluating Lightfastness" section are transferred to 1 cm-wide quartz glass cells, and their absorption spectra are recorded in transmission mode in the wavelength range of 360 to 750 nm using an X-Rite Ci7800 instrument (X-Rite GmbH, Planegg-Martinsried, Germany). These absorption spectra are then corrected for the absorbance of the corresponding uncolored resin by performing the same measurements on the corresponding uncolored resin. Similarly, absorption spectra are recorded in transmission mode for the colored specimens and corrected, normalizing the spectra in each case to the path length of the cell / test specimen.

[0016] Finally, the similarity of the absorption spectra before and after 3D printing is calculated from the measured data by calculating the correlation coefficient R of the normalized absorption (spectral interval 10 nm). The larger the value of R, the greater the similarity of the absorption spectra, and the more stable the color properties of the dye intended for photopolymerization-based 3D printing are, and the more suitable it is for the purpose of this invention. DETAILED DESCRIPTION OF THE INVENTION

[0017] The solution to the problem and subject of the present invention is based on a photopolymerizable composition comprising at least one urethane acrylate resin and at least one red perinone dye selected from 8,9,10,11-tetrachloro-12H-phthaloperin-12-one and / or 14H-benz[4,5]isoquino[2,1-a]perimidin-14-one dissolved therein, and which is selected from L for the color numbers of the RAL color chart starting with "3". * a * b * A 3D-printed product having a color difference ΔE of less than 20 from the coordinates.

[0018] The present invention further provides the L for the color numbers of the RAL color chart starting with "3". * a * b *Also provided is the use of at least one red perinone dye selected from 8,9,10,11-tetrachloro-12H-phthaloperin-12-one and / or 14H-benz[4,5]isoquino[2,1-a]perimidin-14-one, present in dissolved form, to improve the lightfastness and color properties, measured according to DIN EN ISO 4892-2, of photopolymerizable urethane acrylate resin-based compositions and 3D-printed products produced therefrom, having a color difference ΔE from coordinates of less than 20. The improvement in lightfastness and color properties is measured by using an integrating sphere spectrophotometer to record the transmission spectra of corresponding colored urethane acrylate resin specimens before and after photoinduced curing, correcting for the absorbance of the corresponding uncolored resin and normalizing to the path length of the cell / specimen under consideration, and finally calculating the correlation coefficient R of the normalized absorbance to determine the similarity of the absorption spectra from the measurement data before and after 3D printing.

[0019] The present invention further provides a method for producing a urethane acrylate resin comprising dissolving at least one red perinone dye selected from 8,9,10,11-tetrachloro-12H-phthaloperin-12-one and / or 14H-benz[4,5]isoquino[2,1-a]perimidin-14-one in a color number of the RAL color chart starting with "3." * a * b *The present invention also relates to a method for improving the lightfastness and color properties, as measured in accordance with DIN EN ISO 4892-2, of photopolymerizable urethane acrylate resin-based compositions and 3D-printed products produced therefrom, having a color difference ΔE from coordinates of less than 20. The improvement in lightfastness and color properties is measured by using an integrating sphere spectrophotometer to record the transmission spectra of corresponding pigmented urethane acrylate resin specimens before and after photoinduced curing, then correcting for the absorbance of the corresponding unpigmented resin and normalizing to the cell path length / specimen under consideration, and finally calculating the correlation coefficient R of the normalized absorbance to determine the similarity of the absorption spectra from the measurement data before and after 3D printing.

[0020] Finally, the present invention further provides a method for producing a 3D printer based on a photopolymerization-based SLA method or a DLP method, in which a urethane acrylate resin-based composition containing at least one red perinone dye selected from 8,9,10,11-tetrachloro-12H-phthaloperin-12-one and / or 14H-benz[4,5]isoquino[2,1-a]perimidin-14-one in a dissolved form is used to produce a 3D printer based on a RAL color chart starting with "3". * a * b * The present invention also relates to a method for additively manufacturing a 3D-printed product having a color difference ΔE of less than 20 from coordinates.

[0021] For the avoidance of doubt, it should be noted that the scope of the present invention encompasses all of the definitions and parameters set forth below in "general terms" or specified as "preferred ranges," in any desired combination. This also relates to the combination of the stated amounts of the individual components relevant to the claimed processes and uses. Standards cited in the context of this application refer to their latest editions as of the filing date of the present application, unless otherwise specified. Percentage figures are by weight, unless otherwise specified.

[0022] In the context of the present invention, red is understood to mean a color having a color number starting with "3" on the RAL color chart, for example in the RAL color system as described at https: / / de.wikipedia.org / wiki / RAL-Farbe#Rot. More specifically, at the time of filing the present application, the following distinction is made between red hues:

[0023] [Table 1]

[0024] This table gives the device-independent CIE L values ​​for each RAL value for red. * a * b * The color values ​​are shown here, but the L * represents the brightness, and a * denotes the color locus on the red-green axis, and b * represents the color coordinates on the yellow-blue axis. The color model is based on EN ISO 11664-4 "Colorimetry - Part 4: CIE 1976, L * a * b * It is standardized in the "Color Space". * a * b * For more information on color spaces (and more specifically: CIELAB), see: https: / / de.wikipedia.org / wiki / Lab-Farbraum. Each color in the color space is represented by a rectangular coordinate system, L * , a * , b *}. Therefore, a * b * The coordinate plane is constructed using opponent color theory: green and red are opposite each other, a * Located at both ends of the axis, and from blue to yellow is b *The complementary hues are in each case on opposite sides of an angle of 180° to each other, and all achromatic colors are located in the middle of them (the coordinate origin, a * =0, b * =0).

[0025] L * The axis is a number between 0 and 100, representing the brightness (luminance) of the color. In the coordinate system, it is a * b * It stands perpendicular to the surface. It can also be called the neutral gray axis, because all achromatic colors (gray hues) are connected to the black (L * =0) and White (L * = 100). * The axis indicates the green or red component of the color, where negative values ​​represent green and positive values ​​represent red. * The axis represents the blue or yellow component of the color, where negative values ​​represent blue and positive values ​​represent yellow.

[0026] a * The value is between approximately -170 and +100, and b * The values ​​span between -100 and +150, where their maximum value is achieved only at mid-luminance for certain hues. The CIELAB color space has its maximum range in the mid-luminance region, but this varies in height and magnitude depending on the color range.

[0027] However, in the present invention, red-like hues are also included, but they are the L for the color numbers beginning with "3" on the RAL color chart for red. * a * b * The coordinates have a color difference ΔE of less than 20.

[0028] Preferred Embodiments of the Invention The photopolymerizable urethane acrylate resin-based compositions employed in the present invention and the 3D-printed products produced therefrom are L for color numbers beginning with "3" on the RAL color chart for red. * a * b * It is preferable to have a color difference ΔE of less than 10 from the coordinates.

[0029] The photopolymerizable urethane acrylate resin-based compositions employed in the present invention and the 3D-printed products produced therefrom are L for color numbers beginning with "3" on the RAL color chart for red. * a * b * It is particularly preferred to have a color difference ΔE of less than 5 from the coordinates.

[0030] Preferably, the present invention relates to a photopolymerizable composition for additive manufacturing of products by 3D printing, comprising at least one urethane acrylate-based resin and, dissolved therein, at least one red perinone dye selected from 8,9,10,11-tetrachloro-12H-phthaloperin-12-one and / or 14H-benz[4,5]isoquino[2,1-a]perimidin-14-one, for the color numbers of the RAL color chart starting with "3". * a * b * For 3D-printed products having a color difference ΔE of less than 20 from the coordinates.

[0031] Preferably, the present invention provides a method for producing a red perinone dye selected from 8,9,10,11-tetrachloro-12H-phthaloperin-12-one and / or 14H-benz[4,5]isoquino[2,1-a]perimidin-14-one dissolved in a urethane acrylate resin by means of additive manufacturing in 3D printing, according to the L number of the RAL color chart starting with "3". * a * b *It also relates to a method for improving the lightfastness and color properties, measured in accordance with DIN EN ISO 4892-2, of photopolymerizable urethane acrylate resin-based compositions and 3D-printed products produced therefrom, having a color difference ΔE of less than 20 from the coordinates.

[0032] Preferably, the present invention provides a method for the production of L color combinations for the RAL color chart color numbers beginning with "3" by means of additive manufacturing in 3D printing. * a * b * The present invention also relates to the use of at least one red perinone dye selected from 8,9,10,11-tetrachloro-12H-phthaloperin-12-one and / or 14H-benz[4,5]isoquino[2,1-a]perimidin-14-one, present in dissolved form, for improving the lightfastness and color properties, measured in accordance with DIN EN ISO 4892-2, of photopolymerizable urethane acrylate resin-based compositions and 3D-printed products produced therefrom, having a color difference ΔE of less than 20 from the coordinates.

[0033] The present invention preferably relates to a 3D-printed product, its use therein, and a method therefor for improving the lightfastness and color properties of a 3D-printed product, wherein at least one red perinone dye selected from 8,9,10,11-tetrachloro-12H-phthaloperin-12-one and / or 14H-benz[4,5]isoquino[2,1-a]perimidin-14-one is present in dissolved form per 20 to 99.995 parts by weight of a urethane acrylate-based resin (preferably containing at least one additive). Preferably, the solubility of the red perinone dye in the urethane acrylate-based resin according to DIN EN ISO 7579:2010 DE is at least 0.05 g / L at 23°C.

[0034] In addition to at least one red perinone dye, it is particularly preferred to employ 0.5 to 10 parts by mass of a photopolymerization initiator having absorption preferably in the wavelength range of 300 to 450 nm.

[0035] In addition to at least one red perinone dye and 0.5 to 10 parts by weight of a photopolymerization initiator, it is very particularly preferable to employ 0.001 to 1 part by weight of at least one additive, the preferred additives for the purposes of the present invention being at least one leveling agent, at least one stabilizer, at least one additional dye (different from 8,9,10,11-tetrachloro-12H-phthaloperin-12-one or 14H-benz[4,5]isoquino[2,1-a]perimidin-14-one), at least one filler, or at least one organic pigment.

[0036] Urethane acrylate-based resin Photopolymerizable urethane acrylate-based resins preferred in the present invention for additive manufacturing, particularly in 3D printing carried out by photopolymerization, are based on polyurethane acrylates [CAS No. 82116-59-4], polyether urethane acrylates, or urethane acrylate resins. See WO 2005 / 028532 A1, RU 2546966 C1, or M. Alishiri et al., Materials Science and Engineering: C, Vol. 42 (September 2014), pp. 763-773.

[0037] Particularly preferred for use in the context of the present invention are the following: "3D Printing UV Sensitive Resin Clear" (manufactured by Shenzhen Anycubic Technology Co., Ltd. (China)); a colorless resin for high-speed photoexcited 3D printing, containing 30-60% polyurethane acrylate (CAS No. 82116-59-4); 10-40% isooctyl acrylate (CAS No. 29590-42-9); and 2-5% photopolymerization initiator; "Addigy® LPU Rigid 341-02 IM" (manufactured by Covestro Deutschland AG, Leverkusen, Germany); a colorless aliphatic polyether urethane acrylate resin for light-activated 3D printing optimized for high mechanical stress and strength (less than 25% isobornyl methacrylate (CAS 7534-94-3); approximately 10% 4-(1-oxo-2-propenyl)morpholine (CAS No. 5117-12-4); less than 0.15% methacrylic acid (CAS No. 79-41-4) / 2-hydroxyethyl methacrylate (CAS No. 868-77-9)); "Ultracur3D® FL 300" (BASF 3D Printing Solutions GmbH, Ludwigshafen, Germany); a colorless, reactive urethane acrylate resin (1-3% diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (CAS No. 75980-60-8); 15-20% isodecyl acrylate (CAS No. 1330-61-6); 5-10% exo-1,7,7-trimethylbicyclo[2.2.1]hept-2-yl acrylate (CAS No. 5888-33-5); 25-50% 3-ethenyl-5-methyl-2-oxazolidinone (CAS No. 3395-98-0)) optimized for high torsional flexibility and high fracture strength for light-activated 3D printing.

[0038] The photopolymerizable resin used in the present invention preferably contains at least one red perinone dye, and typically contains a mixture of at least one polymerizable acrylate monomer and / or prepolymer, preferably a (poly)urethane acrylate, at least one photopolymerization initiator, and at least one additive. For details of such additives, please refer to International Publication No. WO 2018 / 038954 A1 (the entire contents of this patent application are incorporated herein by reference). Suitable photopolymerization initiators and additives are listed below.

[0039] Photopolymerization initiator Photoinitiators employable in the present invention are typically characterized by one or more of the following properties: one or more light absorption bands in the wavelength range of 300-450 nm and / or a solubility in the curable composition of at least 2 g / L at 23°C; Solubility in the radiation-curable component of the curable resin composition and / or in any additives present; The ability to form chemical species that induce polymerization reactions, for example by free radicals, when exposed to light energy having a wavelength between 300 and 450 nm.

[0040] Particularly preferred in the present invention is the use of at least one photopolymerization initiator from the following group: 2-hydroxy-2-methyl-1-phenylacetone, 1-hydroxycyclohexyl phenyl ketone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, ethyl (2,4,6-trimethylbenzoyl)phenylphosphinate.

[0041] additives The photopolymerizable resin composition employable for 3D printing in the present invention may preferably include at least one additive, stabilizer, or mixture thereof.

[0042] Specifically, the addition of stabilizers to the curable composition can improve the resolution and accuracy of the SLA process by attenuating or preventing undesirable scattering effects, and can also contribute to extending the shelf life of the curable composition. Such stabilizers generally contain phenolic units. Preferred are: p-methoxyphenol (MOP), hydroquinone monomethyl ether (MEHQ), 2,6-di-tert-butyl-4-methylphenol (BHT; Ionol), phenothiazine, 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO), or mixtures thereof. Such stabilizers are preferably used in the following amounts: Lower limit: at least 0.001%, or at least 0.005%, or at least 0.01% by weight; Upper limit: not more than 0.02%, not more than 0.05%, not more than 0.5%, or not more than 1% by weight; Range: 0.001% to 1% or 0.005% to 0.05% by weight; (wherein the % by weight is based on the weight of the curable composition).

[0043] Perinone dye The red perinone dyes employed in the present invention, selected from 8,9,10,11-tetrachloro-12H-phthaloperin-12-one and / or 14H-benz[4,5]isoquino[2,1-a]perimidin-14-one, are characterized in that: · Molecular weight in the range of 50-1000 g / mol; Solubility of at least 0.05 g / L at 23°C in urethane acrylate-based resin compositions that are cured and used in 3D printing; Light absorption maximum in the wavelength range of 400-530 nm; Very good lightfastness in 3D objects; · Extremely stable color properties during the curing process; Contains at least one perinone unit.

[0044] 8,9,10,11-Tetrachloro-12H-phthaloperin-12-one is known as Solvent Red 135 (CAS No. 20749-68-2) and is available from LANXESS Deutschland GmbH (Cologne, Germany).

[0045] 14H-Benz[4,5]isoquino[2,1-a]perimidin-14-one is known as Solvent Red 179 (CAS No. 6829-22-7) and is also available from LANXESS Deutschland GmbH (Cologne, Germany).

[0046] DIN EN ISO 7579:2010 DE This international standard specifies two methods for measuring the solubility of dyes in organic solvents. They can be used for dyes that are chemically unaffected by the solvent and stable and nonvolatile under specific drying conditions. A gravimetric method is recommended for low-boiling solvents (below 120°C), while a photometric method is recommended for high-boiling solvents (above 120°C). The method should be selected according to the specific issues in each case. These methods are primarily suitable for dye concentrations between 1 g and 1000 g per liter of solvent, but can also be used to measure higher solubilities, provided that the viscosity of the test batch does not increase to such an extent that the specified homogenization and centrifugation procedures become impossible. In the present invention, the solubility of the at least one red perinone dye employed in the urethane acrylate-based resin composition cured and used for 3D printing is preferably at least 0.05 g / L at 23°C, as measured according to DIN EN ISO 7579:2010 DE.

[0047] The method for improving the lightfastness and color properties, as measured according to DIN EN ISO 4892-2, of a photopolymerizable urethane acrylate resin-based composition is suitable for additive manufacturing of 3D-printed products by photopolymerization, preferably using a photopolymerization-based SLA 3D printer or DLP 3D printer.

[0048] Therefore, the present invention further provides a method for producing a 3D printer using a photopolymerization-based SLA method or DLP method, in which a urethane acrylate resin-based composition containing at least one red perinone dye selected from 8,9,10,11-tetrachloro-12H-phthaloperin-12-one and / or 14H-benz[4,5]isoquino[2,1-a]perimidin-14-one is used to produce a 3D printer using a urethane acrylate resin-based composition containing at least one red perinone dye selected from 8,9,10,11-tetrachloro-12H-phthaloperin-12-one and / or 14H-benz[4,5]isoquino[2,1-a]perimidin-14-one, in which a 3D printer using a urethane acrylate resin-based composition containing at least one red perinone dye selected from 8,9,10,11-tetrachloro-12H-phthaloperin- * a * b * The present invention also relates to a method for additively manufacturing a 3D-printed product having a color difference ΔE of less than 20 from coordinates. [Example]

[0049] How to measure dye lightfastness in 3D printing To measure the lightfastness of dyes in 3D printing, test specimens were prepared from colored resins with a dye concentration of 0.02% by weight in the resin for the purposes of the present invention. As test specimens, rectangular parallelepipeds with the following dimensions were prepared from the colored resins by 3D printing: Length: 60mm Width: 40mm Height: 2mm

[0050] The specimens were exposed to a light source (xenon lamp) for 95-100 h according to DIN EN ISO 4892-2 using a Xenotest Beta+ instrument (Atlas Material Testing Technology GmbH, Linsengericht-Altenhasslau, Germany).

[0051] Lightfastness was evaluated colorimetrically by recording the transmission spectra of exposed specimens using an X-Rite Ci7800 integrating sphere spectrophotometer (X-Rite GmbH, Planegg-Martinsried, Germany). For this, the following settings were selected: · Optical geometry condition: d / 8゜ · Spectral spacing: 10nm Spectral range: 360~750nm

[0052] From these transmission spectra, the colorimetric data was calculated by the manufacturer's software for the integrating sphere spectrophotometer using the following settings: · Light source / photometer: D65 / 10° · Color space: L * a * b * C * h゜

[0053] The standard for evaluating lightfastness is L * a * b * C * The color difference ΔE between the exposed specimen and the corresponding unexposed specimen in the h° color space. The larger the color difference, and therefore ΔE, the greater the change in color impression caused by exposure to light, and therefore the poorer the lightfastness. ΔE was classified based on a comparison with non-inventive red dyes (see non-inventive examples), whose lightfastness in other applications (e.g., discoloration of bulk plastics) is generally rated as good according to manufacturer data.

[0054] [Table 2]

[0055] Method for assessing the stability of color characteristics The absorption spectra of the pigmented resins before and after photoinduced curing were compared in order to identify changes in the spectral performance that govern the color properties of the dyes.

[0056] The colored resins prepared as described above were transferred to 1 cm-wide quartz glass cells. Absorption spectra were then recorded in transmission mode over the wavelength range of 360–750 nm using an X-Rite Ci7800 instrument (X-Rite GmbH, Planegg-Martinsried, Germany). These were corrected for the absorbance of the uncolored resins by performing the same measurements on the corresponding uncolored resins. Similarly, absorption spectra were recorded and corrected in transmission mode for the colored specimens. The spectra were normalized to the cell / specimen path length in each case.

[0057] The similarity of the absorption spectra before and after 3D printing was then calculated from these measurement data by calculating the correlation coefficient R of the normalized absorption (spectral interval 10 nm). The larger the value of R, the greater the similarity of the absorption spectra, and therefore the more stable the color characteristics of the dye in 3D printing.

[0058] [Table 3]

[0059] Three resin compositions with different properties (see the "Raw Materials" section) were used to create colored 3D-printed objects and tested according to the methods described above. For Resin Composition 1, a dye mixture was also investigated as an example.

[0060] [Table 4]

[0061] [Table 5]

[0062] [Table 6]

[0063] [Table 7]

[0064] [Table 8]

[0065] [Table 9]

[0066] Reactant

[0067] [Table 10]

[0068] [Table 11]

Claims

1. A 3D-printed product based on a photopolymerizable composition comprising at least one urethane acrylate resin and at least one red perinone dye selected from 8,9,10,11-tetrachloro-12H-phthaloperin-12-one and / or 14H-benz[4,5]isoquino[2,1-a]perimidin-14-one dissolved therein, wherein the L for the color numbers of the RAL color chart starting with "3" is ＊ a ＊ b ＊ 3D-printed product with a color difference ΔE of less than 20 from the coordinates.

2. 2. The 3D-printed product of claim 1, wherein the photopolymerizable urethane-based resin is based on a urethane acrylate, a polyurethane acrylate, or a polyether urethane acrylate.

3. 3. The 3D-printed product of claim 1 or 2, wherein 0.005 to 5 parts by weight of the at least one red perinone dye is used per 20 to 99.995 parts by weight of urethane acrylate-based resin.

4. 4. The 3D-printed product of claim 3, wherein in addition to the at least one red perinone dye, 0.5 to 10 parts by weight of a photopolymerization initiator is further employed.

5. 5. The 3D-printed product of claim 4, wherein the photoinitiator has absorption in the wavelength range of 300 to 450 nm.

6. 6. The 3D-printed product of claim 4 or 5, characterized in that in addition to the at least one red perinone dye and the 0.5 to 10 parts by weight of photoinitiator, 0.001 to 1 part by weight of at least one additive is employed.

7. 7. The 3D-printed product of claim 6, wherein the additive is at least one leveling agent, at least one stabilizer, at least one additional dye (different from the red perinone dye), at least one filler, or at least one organic pigment.

8. 8. The 3D-printed product according to any one of claims 1 to 7, characterized in that it is based on photopolymerization 3D printing using an SLA 3D printer or a DLP 3D printer.

9. Use of at least one red perinone dye selected from 8,9,10,11-tetrachloro-12H-phthaloperin-12-one and / or 14H-benz[4,5]isoquino[2,1-a]perimidin-14-one, present in dissolved form, in a range of 100-1500 ppm for the color numbers of the RAL color chart starting with "3". ＊ a ＊ b ＊ Use for improving the lightfastness and color properties, measured in accordance with DIN EN ISO 4892-2, of photopolymerizable urethane acrylate resin-based compositions and 3D-printed products produced therefrom, having a color difference ΔE of less than 20 from the coordinates.

10. 10. Use according to claim 9, characterized in that there is provided a use of said at least one perinone dye in the additive manufacturing of 3D-printed products for photopolymerization-based 3D printing.

11. 11. Use according to claim 9 or 10, characterized in that the urethane acrylate resin-based composition is based on a urethane acrylate, a polyurethane acrylate or a polyether urethane acrylate.

12. L for the number of colors in the RAL color chart starting with "3" ＊ a ＊ b ＊ 1. A method for improving the lightfastness and color properties, measured according to DIN EN ISO 4892-2, of photopolymerizable urethane acrylate resin-based compositions and 3D-printed products produced therefrom, having a color difference ΔE from coordinates of less than 20, characterized in that at least one red perinone dye selected from 8,9,10,11-tetrachloro-12H-phthaloperin-12-one and / or 14H-benz[4,5]isoquino[2,1-a]perimidin-14-one is present in dissolved form in the urethane acrylate resin-based composition.

13. 13. The method of claim 12, wherein the use of the at least one red perinone dye in additive manufacturing of 3D-printed products is carried out in photopolymerization-based 3D printing.

14. 14. The method according to claim 12 or 13, characterized in that the urethane acrylate resin-based composition is based on a urethane acrylate, a polyurethane acrylate, or a polyether urethane acrylate.

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