Additive composition and thermoplastic polymer composition comprising the same

Abstract

A thermoplastic polymer composition comprises a thermoplastic polymer, at least one clarifier, and at least one colorant. A method for preparing a thermoplastic polymer composition comprises the steps of providing a thermoplastic polymer and an additive composition separately, and then mixing the thermoplastic polymer and the additive composition. The additive composition comprises a clarifier and a colorant. Another method for preparing a thermoplastic polymer composition comprises the steps of providing a thermoplastic polymer, at least one clarifier, and at least one colorant separately, and then mixing the thermoplastic polymer, the clarifier, and the colorant. The thermoplastic polymer exhibits a blue hue factor (a) of 0.93 to 1.1 and / or a normalized lightness value (Y') of 64.0 to 69.6. The additive composition comprises at least one clarifier and at least one colorant.

Description

[0001] This application is a divisional application of application No. 201980079640.7 filed on December 19, 2019, entitled "Additive Composition and Thermoplastic Polymer Composition Containing the Additive Composition". Technical Field

[0002] The subject matter of this application and the invention described herein generally relate to additive compositions and thermoplastic polymer compositions comprising such additive compositions. Background Technology

[0003] Thermoplastic polymers have become increasingly prevalent in the world today. Their versatility and the relative ease with which they can be processed into many different forms contribute to this widespread use. This versatility can be attributed in part to the inherent properties of thermoplastic polymers, but at least partly to the development of additives that allow manufacturers to modify the physical properties of these polymers within reasonable limits.

[0004] For example, polypropylene homopolymers and copolymers, which are typically only slightly translucent, can be made more translucent or even almost transparent using a class of additives called clarifying agents. The development and use of such clarifying agents have opened up entirely new applications for polypropylene polymers, applications previously reserved for polymers that were naturally translucent or transparent, or easier to make translucent or transparent (e.g., polystyrene). For instance, clarifying agents have enabled the use of polypropylene polymers in transparent packaging and containers.

[0005] While the development and use of certain additives (e.g., clarifying agents) have improved some physical properties of thermoplastic polymers, there is still room for improvement. In particular, the inventors believe there is a need for combinations of additives that can further improve the perceived clarity or apparent haze of thermoplastic polymers, such as clarifying polypropylene polymers. This application and the invention described herein attempt to address this need. Summary of the Invention

[0006] This invention generally provides additive compositions suitable for addition to thermoplastic polymers, thermoplastic polymer compositions comprising a clarifying agent and at least one colorant, and methods for preparing such thermoplastic polymer compositions. Typically, the additive compositions comprise a clarifying agent and at least one colorant at a relatively low level, wherein the type and amount of the colorant are selected such that the thermoplastic polymer composition comprising the additive composition exhibits a blue hue coefficient and / or normalized brightness value falling within a specified range. Similarly, the thermoplastic polymer compositions of this invention comprise a clarifying agent and at least one colorant, wherein the type and amount of the colorant are selected such that the thermoplastic polymer composition exhibits a blue hue coefficient and / or normalized brightness value falling within a specified range. Thermoplastic polymer compositions exhibiting a specified blue hue coefficient and / or normalized brightness value are considered to have a combination of various desired properties. First, it is believed that such compositions exhibit lower apparent haze compared to compositions not having said blue hue coefficient and / or normalized brightness value. The term “apparent haze” as used herein describes the visually perceived blurring or turbidity of thermoplastic polymer compositions, which is typically observed when looking through articles made from thermoplastic polymer compositions (e.g., panels or containers). Secondly, it is believed that compositions exhibiting a specified blue hue coefficient and / or normalized brightness value do not exhibit any perceptible, visually perceptible coloration.

[0007] In a first embodiment, the present invention provides a thermoplastic polymer composition comprising: (a) a thermoplastic polymer; (b) at least one clarifying agent; and (c) at least one colorant, wherein the amount of the clarifying agent in the thermoplastic polymer composition is from about 50 ppm to about 5000 ppm based on the total weight of the thermoplastic polymer composition, and the thermoplastic polymer exhibits a blue hue coefficient (α) of 0.93 to 1.1 and a normalized brightness value (Y′) of 64.0 to 69.6.

[0008] In a second embodiment, the present invention provides a method for preparing a thermoplastic polymer composition, the method comprising the steps of: (a) providing a thermoplastic polymer; (b) providing an additive composition comprising: (i) at least one clarifying agent; (ii) at least one coloring agent; and (c) mixing the thermoplastic polymer and the additive composition to prepare a thermoplastic polymer composition, wherein the amount of clarifying agent in the thermoplastic polymer composition is from about 50 ppm to about 5000 ppm based on the total weight of the thermoplastic polymer composition, and the thermoplastic polymer has a blue hue coefficient (α) of 0.93 to 1.1 and a normalized brightness value (Y′) of 64.0 to 69.6.

[0009] In a third embodiment, the present invention provides a method for preparing a thermoplastic polymer composition, the method comprising the steps of: (a) providing a thermoplastic polymer; (b) providing at least one clarifying agent; (c) providing at least one coloring agent; and (d) mixing the thermoplastic polymer, the clarifying agent and the coloring agent to prepare a thermoplastic polymer composition, wherein the amount of the clarifying agent present in the thermoplastic polymer composition is from about 100 ppm to about 5000 ppm based on the total weight of the thermoplastic polymer composition, and the thermoplastic polymer has a blue hue coefficient (α) of 0.93 to 1.1 and a normalized brightness value (Y′) of 64.0 to 69.6.

[0010] In a fourth embodiment, the present invention provides an additive composition comprising essentially: (a) at least one clarifying agent; and (b) at least one coloring agent, wherein the amount of coloring agent present in the additive composition is such that a thermoplastic polymer composition prepared with the additive composition has a blue hue coefficient (α) of 0.93 to 1.1 and a normalized brightness value (Y′) of 64.0 to 69.6, and the thermoplastic polymer composition comprises a thermoplastic polymer and the additive composition, the amount of the additive composition being sufficient to provide about 100 ppm to about 5000 ppm of clarifying agent in the thermoplastic polymer composition. Detailed Implementation

[0011] As described above, the present invention provides additive compositions suitable for addition to thermoplastic polymers, thermoplastic polymer compositions comprising at least one clarifying agent and at least one colorant, and methods for preparing such thermoplastic polymer compositions. Various aspects of these embodiments of the invention will be described below.

[0012] The thermoplastic polymer used in this invention may be any suitable thermoplastic polymer. As used herein, the term "thermoplastic polymer" refers to a polymeric material that melts to form a flowable liquid when exposed to sufficient heat and reverts to a solid state upon adequate cooling. In some preferred embodiments, the thermoplastic polymer is a polyolefin. The thermoplastic polymer may be any suitable polyolefin, such as polypropylene, polyethylene, polybutene, and poly(4-methyl-1-pentene), and combinations or mixtures thereof. In some preferred embodiments, the thermoplastic polymer is a polyolefin selected from the group consisting of polypropylene homopolymers (e.g., atactic polypropylene, isotactic polypropylene, and syndiotactic polypropylene), polypropylene copolymers (e.g., atactic polypropylene copolymers), and mixtures thereof. Suitable polypropylene copolymers include, but are not limited to, atactic copolymers prepared by polymerization of propylene in the presence of comonomers selected from ethylene, but-1-ene (i.e., 1-butene), and hex-1-ene (i.e., 1-hexene). In such random copolymers of polypropylene, the comonomers may be present in any suitable amount, but are typically present in amounts of about 10 wt.% or less (e.g., about 1 to about 7 wt.%, or about 1 to about 4.5 wt.%).

[0013] The clarifying agent used in the additive compositions and methods of the present invention may be any suitable clarifying agent. Suitable clarifying agents include, but are not limited to, triamides, bisphenol phosphates, carboxylates, and acetal compounds. For example, suitable triamide clarifying agents include, but are not limited to, amide derivatives of benzene-1,3,5-tricarboxylic acid, derivatives of N-(3,5-di-carbamoyl-phenyl)-formamide (e.g., N-[3,5-di-(2,2-dimethyl-propionylamino)-phenyl]-2,2-dimethyl-propionamide), derivatives of 2-carbamoyl-malondiamide (e.g., N,N'-di-(2-methyl-cyclohexyl)-2-(2-methyl-cyclohexylcarbamoyl)-malondiamide), and combinations thereof. Suitable bisphenol phosphate clarifying agents include 2,2'-methylenedi-(4,6-di-tert-butylphenyl) phosphates, such as aluminum 2,2'-methylenedi-(4,6-di-tert-butylphenyl) phosphate, lithium 2,2'-methylenedi-(4,6-di-tert-butylphenyl) phosphate, and combinations thereof. Suitable carboxylate clarifying agents include, but are not limited to, salts of benzoic acid (e.g., sodium benzoate), salts of cyclohexane-1,2-dicarboxylic acid (e.g., calcium cyclohexane-1,2-dicarboxylic acid), and salts of bicyclo-[2.2.1]-heptane-2,3-dicarboxylic acid (e.g., disodium bicyclo-[2.2.1]-heptane-2,3-dicarboxylic acid).

[0014] Suitable acetal clarifying agents include acetal compounds prepared by the condensation reaction of polyols with aromatic aldehydes. Suitable polyols for preparing such acetal clarifying agents include, but are not limited to, acyclic polyols, such as xylitol and sorbitol. Suitable polyols also include C1-substituted sugar alcohols. As used herein, the term "C1-substituted sugar alcohol" refers to a compound in which the terminal carbon atom of the sugar alcohol (e.g., a terminal carbon atom typically substituted by a single hydroxyl group) is substituted by an additional non-hydrogen group. C1-substituted sugar alcohols may be substituted with any suitable group. In some embodiments, C1-substituted sugar alcohols may be substituted with groups selected from the group consisting of alkyl groups, alkenyl groups, alkoxy groups, hydroxyalkyl groups, haloalkyl groups, and derivatives thereof. Suitable aromatic aldehydes for preparing such acetal clarifying agents include, but are not limited to, aromatic aldehydes containing a single aldehyde group with the remaining positions on the aromatic ring being unsubstituted or substituted. Thus, suitable aromatic aldehydes include benzaldehyde and substituted benzaldehydes (e.g., 3,4-dimethylbenzaldehyde). In some embodiments, benzaldehyde may be substituted with one or more groups selected from the group consisting of alkyl groups, alkenyl groups, alkoxy groups, carboxyl groups, halogens, and aryl groups (e.g., phenyl groups). Suitable acetals obtained by the reaction of an acyclic polyol with a benzaldehyde compound include, but are not limited to, the acetals disclosed in U.S. Patent Nos. 5,135,975, 7,157,510, and 7,262,236, all of which are incorporated herein by reference in their entirety. The acetals prepared by the above reaction may be monoacetals, diacetals, or triacetals (i.e., compounds comprising one, two, or three acetal groups, respectively), with diacetals being preferred.

[0015] In some embodiments, the acetal clarifying agent may be an acetal compound conforming to the structure of formula (I):

[0016] (I)

[0017]

[0018] In the structure of formula (I), R1 is selected from the group consisting of hydrogen, alkyl groups, alkenyl groups, hydroxyalkyl groups, alkoxy groups, haloalkyl groups, and their derivatives. R2, R3, R4, R5, R6, R7, R8, R9, R 10 and R 11 Each group is independently selected from the following groups: hydrogen, alkyl groups, alkoxy groups, alkenyl groups, aryl groups, carboxyl groups, and halogens. R 12 The hydroxyalkyl group is selected from ─CH2OH and ─CH(OH)CH2OH.

[0019] In some embodiments of the present invention, R1 is selected from alkyl groups and alkenyl groups, and R2, R3, R5, R6, R7, R8, R... 10 and R 11Both are hydrogen, R 12 The form is ─CH(OH)CH2OH, and R4 and R9 are both alkyl groups. In a more specific embodiment, R1 is a n-propyl group, and R2, R3, R5, R6, R7, R8, R... 10 and R 11 Both are hydrogen, R 12 The symbol is ─CH(OH)CH2OH, and R4 and R9 are both n-propyl groups.

[0020] In other embodiments of the invention, R1 is hydrogen, and R2, R5, R6, R7, R8, and R... 11 All are hydrogen, R3, R4, R9 and R 10 All are alkyl groups, and R 12 The form is ─CH(OH)CH2OH. In a more specific embodiment, R1 is hydrogen, and R2, R5, R6, R7, R8, and R... 11 All are hydrogen, R3, R4, R9 and R 10 All are methyl groups, and R 12 It is ─CH(OH)CH2OH.

[0021] In other embodiments, the clarifying agent is selected from the group consisting of: (a): compounds of formula (I), wherein R2, R3, R4, R5, R6, R7, R8, R9, R 10 and R 11 All are hydrogen, and R 12 (a) ─CH(OH)CH2OH; (b) Compounds of formula (I), wherein R2, R3, R5, R6, R7, R8, R 10 and R 11 All are hydrogen, R4 and R9 are both methyl groups, and R 12 (c) : Compounds of formula (I), wherein R2, R5, R6, R7, R8 and R 11 All are hydrogen, R3, R4, R9 and R 10 All are methyl groups, and R 12 (a) is ─CH(OH)CH2OH; and (d) is a mixture of at least two of (a), (b) and (c).

[0022] The clarifying agent may be present in the compositions of the present invention in any suitable amount. Those skilled in the art will understand that a suitable amount of clarifying agent will depend on several factors, such as the characteristics of the particular clarifying agent, the particular polymer to be clarified by the clarifying agent, and the desired clarity and / or haze level of the final polymer composition. In some possibly preferred embodiments, the clarifying agent is present in the thermoplastic polymer composition in an amount of about 50 ppm to about 5000 ppm based on the total weight of the thermoplastic polymer composition. In some possibly preferred embodiments, for example, when the clarifying agent is an acetal compound conforming to the structure of formula (I), the clarifying agent is present in the thermoplastic polymer composition in an amount of about 1000 ppm to about 2500 ppm based on the total weight of the thermoplastic polymer composition.

[0023] In addition to a clarifying agent, the compositions of the present invention also contain at least one colorant. Suitable colorants include, but are not limited to, pigments, dyes, polymeric colorants, and mixtures thereof. As used herein, the term "polymeric colorant" refers to a colorant comprising a chromophore and at least one oligomer or polymeric component bound to that chromophore. Suitable polymeric colorants include, but are not limited to, polymeric colorants sold by Millicken & Company. Dyes may be any suitable dye, such as acid dyes, solvent dyes, vat dyes, or mixtures thereof. Suitable dyes include, but are not limited to, Acid Blue 9, Acid Blue 74, Solvent Blue 97, Vat Blue 6, and mixtures or combinations thereof. For example, in some embodiments, the colorant may comprise a mixture of Vat Blue 6 and Acid Blue 74. In some possibly preferred embodiments, the composition comprises one or more pigments as colorants. Suitable pigments include, but are not limited to, Pigment Blue 29, Pigment Blue 63, Pigment Violet 15, Carbon Black, and mixtures thereof. In a preferred embodiment, the composition comprises a mixture of a blue colorant and a black colorant, for example, a mixture of a blue pigment and a black pigment (e.g., a mixture of Pigment Blue 29 and Carbon Black).

[0024] In contrast to compositions in which colorants are used to impart a significant and perceptible color to the composition, and any articles made therefrom, the compositions of the present invention contain relatively small amounts of colorants. In fact, the amount of colorant present in the thermoplastic polymer compositions of the present invention is low enough that most observers would describe the polymer composition or any article made therefrom as uncolored or at most, without noticeable coloration. Indeed, when viewed with the naked eye, the hue imparted by the colorant to the polymer composition or article made therefrom is only perceptible when comparing the polymer composition or article to a similar composition or article without colorants. Despite this slight or almost imperceptible coloration, the inventors have found that articles made from such compositions are generally perceived as having lower haze or higher clarity compared to similar articles made from compositions without colorants, although haze measurements of such articles show no statistically significant difference in haze values.

[0025] Because such low colorant loadings are used in the compositions of the present invention, it is difficult to meaningfully express the amount of colorant present in the compositions of the present invention using conventional units, such as concentration or percentage based on weight. This is partly because different colorants exhibit different tinting intensities, meaning that a given weight of one colorant (e.g., Pigment Blue 29) will impart a different amount of color to the composition compared to the same weight of a different colorant (e.g., Vat Blue 6). Therefore, if the compositions of the present invention are defined solely by specifying a weight percentage of the colorant, this definition could include compositions that do not have the desired effect (e.g., lower perceived haze). For example, if the amount of a particularly strong colorant is at the upper limit of the weight-based range, the composition may exhibit readily perceptible tinting and would actually be perceived as having higher haze than a comparable control without the colorant. Accordingly, the inventors have found that the amount of colorant present in the compositions of the present invention is better characterized by detecting certain optical properties of the polymer composition (i.e., the polymer composition of the present invention or a polymer composition made using the additive composition of the present invention). Therefore, the amount of colorant in the composition is defined as sufficient to produce a composition exhibiting the desired optical properties. Specifically, the composition was analyzed by ultraviolet-visible (UV-Vis) spectroscopy to evaluate its absorbance in the 500 nm to 700 nm range (hereinafter referred to as the "blue hue coefficient (α)"). The inventors further discovered that the amount of colorant can be characterized by determining the normalized luminance value (Y′) of the composition under specified conditions.

[0026] The thermoplastic polymer composition of the present invention preferably exhibits a blue hue coefficient (α) of 0.93 to 1.1. The blue hue coefficient (α) is calculated by the following equation.

[0027]

[0028] In the equation, This is the average (arithmetic mean) of the absorbance in the UV-Vis spectrum from 500 nm to 700 nm (calculated at 1 nm intervals, including the endpoints). A is the average (arithmetic mean) of the absorbance in the UV-Vis spectrum from 800 nm to 880 nm (calculated at 1 nm intervals, including the endpoints). 500 The absorbance at 500 nm in the UV-Vis spectrum, and A 700 This represents the absorbance at 700 nm in the UV-Vis spectrum. The UV-Vis spectrum of the thermoplastic polymer composition was obtained using a conventional UV-Vis spectrophotometer (e.g., a UV-Vis spectrophotometer equipped with an integrating sphere, such as the PerkinElmerLAMBDA with a 2 nm optical slit equipped with a Labsphere RSA-PE-20 integrating sphere fitting). TM A 35mm spectrophotometer was used to measure the absorbance from a single 0.76mm (30mil) injection-molded slab. The UV-Vis spectrum from 400nm to 1100nm was measured at a scan rate of approximately 480nm / min, and the data was smoothed every 4nm using the spectrophotometer's mounting software. The raw absorbance data obtained from the spectrophotometer were then exported and analyzed using spreadsheet software (e.g., Microsoft Excel) to calculate the values ​​necessary to determine the blue hue coefficient using the equations described above.

[0029] The thermoplastic polymer compositions of the present invention preferably exhibit a blue hue factor (α) of 0.93 to 1.1 (e.g., 0.93 to 1.09, 0.93 to 1.08, or 0.93 to 1.07), 0.94 to 1.1 (e.g., 0.94 to 1.09, 0.94 to 1.08, or 0.94 to 1.07), 0.95 to 1.1 (e.g., 0.95 to 1.09, 0.95 to 1.08, or 0.95 to 1.07), 0.96 to 1.1 (e.g., 0.96 to 1.09, 0.96 to 1.08, or 0.96 to 1.07), or 0.97 to 1.1 (e.g., 0.97 to 1.09, 0.97 to 1.08, or 0.97 to 1.07).

[0030] The thermoplastic polymer composition of the present invention preferably exhibits a normalized brightness value (Y′) of 64.0 to 69.6. The normalized brightness value (Y′) of the thermoplastic polymer composition is calculated by the following equation:

[0031]

[0032] In the equation, Y is the Y value of the thermoplastic polymer composition measured by a spectrophotometer (from the CIE XYZ color space), Y0 is the Y value of a standard white background (e.g., a white calibration sheet for the spectrophotometer) measured by a spectrophotometer, and H is the haze. The Y values ​​and haze were measured on five 0.76 mm (30 mil) injection-molded panels (all made of the same thermoplastic polymer composition), stacked together with a 0.51 mm (20 mil) air gap between adjacent panels. When measuring the Y value of the panels, the standard white background (e.g., a white calibration sheet for the spectrophotometer) was positioned against the back of the fifth panel (i.e., against the back of the panel furthest from the spectrophotometer orifice) to reflect light back to the spectrophotometer's detector. The standard white background was not used when measuring haze. The haze of the stacked trim panels was measured according to ASTM D1003 using a haze meter, such as the BYK-Gardner haze-gard i haze meter. The Y-value of the stacked trim panels and the Y0 value against a standard white background were measured using a reflectance-mode spectrophotometer, such as the X-riteCi7800 spectrophotometer with a pulsed xenon light source (D65 calibrated). The spectrophotometer was equipped with a 25mm orifice and a D65 calibrated light source (UV filters were used to exclude UV light from the light source), and specular reflectance was included in the measurement. Finally, the spectrophotometer data were analyzed using a 10° observer color matching function against a CIE cool white fluorescent light source. To improve the accuracy of the Y-value measurement, it was preferable to perform two measurements on the trim panels and take the average of the two measurements.

[0033] The thermoplastic polymer compositions of the present invention preferably exhibit a content of 64.0 to 69.6 (e.g., 64.0 to 69.5, 64.0 to 69.4, 64.0 to 69.3, 64.0 to 69.2, 64.0 to 69.1, 64.0 to 69.0, 64.0 to 68.9, 64.0 to 68.8, or 64.0 to 68.7), 64.5 to 69.6 (e.g., 64.5 to 69.5, 64.5 to 69.4, 64.5 to 69.3, 64.5 to 69.2, 64.5 to 69.1, 64.5 to 69.0, 64.5 to 68.9, 64.5 to 68.8, or 64.5 to 68.7), or 65.0 to 69.6 (e.g., 65.0 to 69). 5. 65.0 to 69.4, 65.0 to 69.3, 65.0 to 69.2, 65.0 to 69.1, 65.0 to 69.0, 65.0 to 68.9, 65.0 to 68.8, or 65.0 to 68.7), 65.5 to 69.6 (e.g., 65.5 to 69.5, 65.5 to 69.4, 65.5 to 69). 3. 65.5 to 69.2, 65.5 to 69.1, 65.5 to 69.0, 65.5 to 68.9, 65.5 to 68.8, or 65.5 to 68.7), 66.0 to 69.6 (e.g., 66.0 to 69.5, 66.0 to 69.4, 66.0 to 69.3, 66.0 to 69.2, 66.0 to 69. 1. 66.0 to 69.0, 66.0 to 68.9, 66.0 to 68.8, or 66.0 to 68.7), 66.5 to 69.6 (e.g., 66.5 to 69.5, 66.5 to 69.4, 66.5 to 69.3, 66.5 to 69.2, 66.5 to 69.1, 66.5 to 69.0, 66.5 to 68). 9. 66.5 to 68.8, or 66.5 to 68.7), 67.0 to 69.6 (e.g., 67.0 to 69.5, 67.0 to 69.4, 67.0 to 69.3, 67.0 to 69.2, 67.0 to 69.1, 67.0 to 69.0, 67.0 to 68.9, 67.0 to 68.8, or 67.0 to 68. 7) 67.1 to 69.6 (e.g., 67.1 to 69.5, 67.1 to 69.4, 67.1 to 69.3, 67.1 to 69.2, 67.1 to 69.1, 67.1 to 69.0, 67.1 to 68.9, 67.1 to 68.8, or 67.1 to 68.7), 67.2 to 69.6 (e.g., 67.2 to 69.5, 67.2 to 69.4, 67.2 to 69.3, 67.2 to 69.2, 67.2 to 69.1, 67.2 to 69.0, 67.2 to 68.9, 67.2 to 68.8, or 67.2 to 68.7), 67.3 to 69.6 (e.g., 67.3 to 69.5, 67.3 to 69.4, 67.3 to 69.3, 67.3 to 69.2, 67.3 to 69.1, 67.3 to 69.0, 67.3 to 68.9, 67.3 to 68.8, or 67.3 to 68.7), 67.4 to 69.6 (e.g., 67.4 to 69.5, 67.4 to 69.4, 67.4 to 69.3, 67.4 to 69.2, 67.4 to 69.1, 67.4 to 69.0, 67.4 to 68.9). 67.4 to 68.8, or 67.4 to 68.7), 67.5 to 69.6 (e.g., 67.5 to 69.5, 67.5 to 69.4, 67.5 to 69.3, 67.5 to 69.2, 67.5 to 69.1, 67.5 to 69.0, 67.5 to 68.9, 67.5 to 68.8, or 67.5 to 68.7), 67.5 to 69.6 (e.g., 67.5 to 69.5, 67.5 to 69.4, 67.5 to 69.3, 67.5 to 69.2, 67.5 to 69.1, 67.5 to 69.0, 67.5 to 68.9, 67.5 to 68.8, or 67.5 to 68.7), 67.6 to 69.6 (e.g., 67.6 to 69.5, 67.6 to 69.4, 67.6 to 69.3, 67.6 to 69.2, 67.6 to 69.1, 67.6 to 69.6). Normalized luminance values ​​(Y′) of 9.0, 67.6 to 68.9, 67.6 to 68.8, or 67.6 to 68.7, or 67.7 to 69.6 (e.g., 67.7 to 69.5, 67.7 to 69.4, 67.7 to 69.3, 67.7 to 69.2, 67.7 to 69.1, 67.7 to 69.0, 67.7 to 68.9, 67.7 to 68.8, or 67.7 to 68.7).

[0034] Therefore, the amount of colorant contained in the thermoplastic polymer composition is sufficient to prepare a polymer composition exhibiting a blue hue coefficient (α) of 0.93 to 1.1 or falling within one of the other blue hue coefficient ranges described above. The amount of colorant contained in the thermoplastic polymer composition is also preferably sufficient to prepare a polymer composition exhibiting a normalized luminance value (Y′) of 64.0 to 69.6 or falling within one of the other normalized luminance value ranges described above.

[0035] While the inventors consider the blue hue coefficient and / or normalized luminance value sufficient to describe the amount of colorant present in the thermoplastic polymer composition, for certain preferred embodiments, the composition may be further characterized by certain weight ranges of the colorant. For example, when the thermoplastic polymer composition contains carbon black, the composition preferably contains less than 2 ppm (e.g., less than 1.75 ppm) of carbon black, such as 0.25 to 1.75 ppm (e.g., 0.25 to 1.5 ppm, 0.25 to 1.25 ppm, 0.25 to 1 ppm, or 0.25 to 0.75 ppm). When the thermoplastic polymer composition contains a blue or purple pigment (e.g., Pigment Blue 29, Pigment Blue 63, or Pigment Violet 15), the composition preferably contains about 4 to about 50 ppm (e.g., about 10 to about 50 ppm or about 4 to about 40 ppm) of the pigment. In a preferred embodiment, the thermoplastic polymer composition comprises 3.5 to 40 ppm of Pigment Blue 29, 0 to 5 ppm of Pigment Violet 15, and 0.25 to 2 ppm of Carbon Black. In another preferred embodiment, the thermoplastic polymer composition comprises 3.5 to 40 ppm of Pigment Blue 29, 0 to 4 ppm of Pigment Violet 15, and 0.25 to 1.75 ppm of Carbon Black. In a more specific preferred embodiment, the thermoplastic polymer composition comprises calcium cyclohexane-1,2-dicarboxylate (preferably 300 to 1000 ppm or 480 to 500 ppm), 10 to 30 ppm of Pigment Blue 29, 0 to 5 ppm of Pigment Violet 15, and 0.2 to 1 ppm of Carbon Black. In such preferred embodiments, the total amount of Pigment Blue 29, Pigment Violet 15, and Carbon Black present in the composition is preferably 10 to 35 ppm (e.g., 10 to 31 ppm). In another specific preferred embodiment, the thermoplastic polymer composition comprises: 2000 to 4000 ppm (preferably 3000 to 4000 ppm) of a compound of formula (I), wherein R1 is a n-propyl group, and R2, R3, R5, R6, R7, R8, R... 10 and R 11 Both are hydrogen, R 12 The composition comprises -CH(OH)CH2OH, and R4 and R9 are both n-propyl groups; 3.5 to 25 ppm of Pigment Blue 29; 0 to 4 ppm of Pigment Violet 15; and 0.25 to 1.75 ppm of Carbon Black. In such preferred embodiments, the total amount of Pigment Blue 29, Pigment Violet 15 and Carbon Black present in the composition is preferably 4.75 to 25 ppm.

[0036] As described above, the present invention provides an additive composition substantially composed of at least one clarifying agent and at least one coloring agent. The term "substantially composed of" used in this embodiment of the invention distinguishes the additive composition from the thermoplastic polymer to which the additive composition has been added. In other words, the term indicates that the additive composition is formulated in such a way that it is intended to be added to the thermoplastic polymer, rather than used on its own in the manufacture of the final article. Therefore, as used in the context of this application, the term "substantially composed of" indicates that, if the thermoplastic polymer is present in the additive composition, the relative amount of the thermoplastic polymer present in the additive composition is significantly less than the amount of the thermoplastic polymer present in the "final" polymer composition to be used in other methods of molding or preparing the article. Thus, in some potentially preferred embodiments, the additive composition contains about 90 wt.% or less (e.g., about 85 wt.% or less, or about 80 wt.% or less) of the thermoplastic polymer based on the total weight of the additive composition. In some other embodiments, the additive composition comprises about 25 wt.% or less (e.g., about 20 wt.% or less, about 15 wt.% or less, about 10 wt.% or less, or about 5 wt.% or less) of a thermoplastic polymer based on the total weight of the additive composition. When used in additive compositions, the term "consistently composed of" is not intended to exclude the presence of other additives commonly used in thermoplastic polymers, such as nucleating agents, antioxidants, deacidifying agents, slip agents, antistatic agents, and polymer processing aids. Therefore, the additive compositions of the present invention may be masterbatches comprising clarifying agents, colorants, carrier resins, and optionally other additives, or the additive compositions may be dust-free blends (NDBs) comprising clarifying agents, colorants, and optionally other additives.

[0037] The above-described additive composition contains a certain amount of colorant, such that when the additive composition is added to the thermoplastic polymer in an amount sufficient to provide about 100 to about 5000 ppm (e.g., about 500 to about 4000 ppm) of clarifying agent in the resulting thermoplastic polymer composition, the thermoplastic polymer composition exhibits a blue hue coefficient (α) of 0.93 to 1.1 or falling within one of the other blue hue coefficient ranges described above. The thermoplastic polymer composition also preferably exhibits a normalized brightness value (Y′) of 64.0 to 69.6 or falling within one of the other normalized brightness value ranges described above. The thermoplastic polymer used to prepare such thermoplastic polymer compositions may be any of the above-described thermoplastic polymers, but is preferably selected from the group consisting of polypropylene homopolymers, polypropylene random copolymers, and mixtures thereof.

[0038] As described above, the present invention provides a method for preparing a thermoplastic polymer composition. In a first embodiment of the method, the method includes the steps of: providing a thermoplastic polymer, providing an additive composition comprising at least one clarifying agent and at least one colorant, and mixing the thermoplastic polymer and the additive composition to prepare the thermoplastic polymer composition. In this embodiment of the method, the thermoplastic polymer, clarifying agent, and colorant may be any of the above-described types. Furthermore, in this embodiment, the thermoplastic polymer and the additive composition may be provided separately. In other words, the thermoplastic polymer and the additive composition may be provided in a separate form or in a composition that is not mixed together prior to the mixing step. In this embodiment, the thermoplastic polymer may be provided in the form of a composition comprising other additives commonly used in polymer processing, such as antioxidants, deacidifying agents, slip agents, and polymer processing aids. The additive composition may also contain other additives commonly used in polymer processing, such as those described above.

[0039] In a second method embodiment, the method includes the steps of: providing a thermoplastic polymer, providing at least one clarifying agent, providing at least one coloring agent, and mixing the thermoplastic polymer, clarifying agent, and coloring agent to prepare a thermoplastic polymer composition. In this method embodiment, the thermoplastic polymer, clarifying agent, and coloring agent may be any of the above-mentioned types. Furthermore, in this embodiment, the thermoplastic polymer, clarifying agent, and coloring agent may be provided separately. In other words, the thermoplastic polymer, clarifying agent, and coloring agent may be provided in a separate form or in a composition that is not mixed together prior to the mixing step. As in other method embodiments, the thermoplastic polymer may be provided in a composition containing other additives commonly used in polymer processing. Similarly, the clarifying agent and coloring agent may be included in a separate composition containing other additives commonly used in polymer processing.

[0040] All the above-described methods involve a mixing step. In each method, individual components can be mixed using any suitable technology or equipment. For example, components can be mixed in a paddle mixer, ribbon mixer, double cone mixer, vertical spiral mixer (e.g., a Nauta mixer), plowshare mixer, or high-shear mixer. Several of the mixing devices listed above can be operated in batch or continuous mode; therefore, the mixing step can be performed in a batch or continuous manner. Components can be mixed for any suitable amount of time, but generally, the components are mixed until they are substantially homogeneous.

[0041] It is believed that the thermoplastic polymer compositions described herein can be used to prepare thermoplastic articles. The thermoplastic polymer compositions can be formed into desired thermoplastic articles by any suitable technique, such as injection molding, injection rotational molding, blow molding (e.g., injection blow molding or injection stretch blow molding), extrusion (e.g., sheet extrusion, film extrusion, cast film extrusion or foam extrusion), extrusion blow molding, thermoforming, rotational molding, film blow molding (blown film), film casting (cast film), etc.

[0042] The thermoplastic polymer compositions described herein can be used to prepare any suitable articles or products. Suitable products include, but are not limited to: medical devices (e.g., pre-filled syringes for distillation applications, intravenous supply containers, and blood collection devices), food packaging, fluid containers (e.g., bottles, containers for beverages, pharmaceuticals, personal care compositions, shampoos, etc.), household goods (e.g., reusable food containers, storage bags, etc.), wardrobes, microwaveable articles, shelves, cabinet doors, mechanical parts, automotive parts, sheets (e.g., sheets for thermoforming processes), preforms for blow molding, pipes, tubing, injection-molded parts, rotationally molded parts, blow-molded parts, films, fibers, etc.

[0043] The following examples further illustrate the subject matter described above, but should not be construed as limiting its scope in any way.

[0044] Example 1

[0045] This embodiment demonstrates the preparation of thermoplastic polymer compositions according to the present invention and certain properties of such polymer compositions. Several different polymer compositions were prepared using polypropylene homopolymer resins, specifically LyondellBasell Pro-fax 6301 (HPP6301) polypropylene homopolymer resin. Each polymer composition was prepared by mixing the resin with the components listed in Table 1 below, and then extruding the mixture using a Deltaplast single-screw extruder. Subsequently, the extruded polymer compositions were injection molded into several 0.76 mm (30 mil) panels (dimensions of 50.8 mm × 76.2 mm × 0.76 mm or 2.00 inch × 3.00 inch × 0.03 inch) using a 40-ton Arburg injection molding machine. These panels were then analyzed as described below.

[0046] To ensure precise addition of very small amounts of each colorant to the polymer composition and good dispersion of the colorant, each colorant was added to the resin separately using 0.02 wt.% colorant masterbatches. These 0.02 wt.% colorant masterbatches were prepared as follows: first, a 1 wt.% masterbatch of the colorant was prepared, and then the 1 wt.% masterbatch was added to the resin to prepare the 0.02 wt.% colorant masterbatch. Each 1 wt.% colorant masterbatch was prepared by mixing 1 wt.% of the colorant, a standard stabilizer package (i.e., 500 ppm Irganox 1010, 1000 ppm Irgafos 168, and 800 ppm calcium stearate), and HPP6301 resin. The resulting mixture was then melt-blended on a Deltaplast single-screw extruder (1 inch diameter, L / D 30:1). Next, 1 part by weight of 1 wt.% colorant masterbatch was then mixed with 49 parts by weight of HPP6301 resin particles (which had been pre-compacted using the aforementioned standard stabilizer). This mixture was then extruded using a Deltaplast single-screw extruder to prepare 0.02 wt.% colorant masterbatch. The following 0.02 wt.% colorant masterbatches were prepared and used to prepare polymer compositions: 0.02 wt.% ultramarine blue (pigment blue 29) masterbatch; 0.02 wt.% ultramarine violet (pigment violet 15) masterbatch; and 0.02 wt.% carbon black masterbatch. The carbon black masterbatch was prepared using... F138 carbon black (made from Orion Engineered Carbons).

[0047] The masterbatch composition is also used to add various clarifying agents to the polymer composition. 4 wt.% HPN20E nucleating agent masterbatch, through... It is made by mixing HPN 20E nucleating agent (from Millicken & Company), 500 ppm Irganox 1010, 1000 ppm Irgafos 168, magnesium aluminum hydrotalcite acid remover (from Kisuma Chemicals DHT-4V) and HPP6301 resin. HPN 20E nucleating agent contains the clarifying agent cis-cyclohexane-1,2-dicarboxylate calcium. The mixture is extruded on a Deltaplast extruder to prepare a masterbatch. 20 wt.% 1,2,3-trideoxy-4,6:5,7-di-O-[(4-propanphenyl)methylene]nonanol masterbatch is prepared by mixing 1,2,3-trideoxy-4,6:5,7-di-O-[(4-propanphenyl)methylene]nonanol, the aforementioned standard stabilizer, and HPP6301 resin. The mixture is extruded on a Deltaplast extruder to prepare a masterbatch.

[0048] As described above, Table 1 lists the clarifying and coloring agents used to prepare the various polymer compositions. The amounts provided in Table 1 represent the final concentration of the clarifying or coloring agent in the polymer composition. Therefore, the amount of suitable masterbatch added to the resin is greater than the amounts listed in Table 1. In the table, "UMB" represents ultramarine blue, "UMV" represents ultramarine violet, "CB" represents carbon black, and "CA1" represents... HPN 20E nucleating agent, and "CA2" is 1,2,3-trideoxy-4,6:5,7-di-O-[(4-propenyl)methylene]nonanol.

[0049] Table 1 shows the concentrations of clarifying agent and coloring agent in samples 1-7.

[0050]

[0051]

[0052] Decorative panels (samples 1–7) made from each polymer composition were then analyzed to determine the blue hue coefficient (α) and normalized brightness value (Y′) as described above. Specifically, the blue hue coefficient (α) of each polymer composition was calculated using the above equations based on data obtained from the UV-Vis spectra of individual decorative panels made from the polymer compositions. The UV-Vis spectra of the thermoplastic polymer compositions were obtained using a PerkinElmer LAMBDA with a 2nm optical slit equipped with a Labsphere RSA-PE-20 integrating sphere fitting. TM Measurements were performed using a 35-inch spectrophotometer. The UV-Vis spectrum was measured from 400 nm to 1100 nm at a scan rate of approximately 480 nm / min, and the data were smoothed every 4 nm using the spectrophotometer's software. The raw absorbance data obtained from the spectrophotometer were then exported and analyzed using Microsoft Excel software to calculate... and The blue hue coefficient (α) of each polymer composition is listed in Table 2 below.

[0053] Normalized luminance values ​​(Y′) were calculated using data from five stacked panels (all made of the same polymer composition), arranged with a 0.51 mm (20 mil) air gap between adjacent panels, according to the equation above. The haze of the stacked panels was measured according to ASTM D1003 using a BYK-Gardner haze-gard i haze meter. The Y-values ​​of the stacked panels were measured in reflectance mode using an X-rite Ci7800 spectrophotometer with a pulsed xenon light source (D65 calibrated). As described above, a white calibration plate for the spectrophotometer was placed against the back of the fifth panel to reflect light back to the spectrophotometer's detector. The spectrophotometer was equipped with a 25 mm orifice and a D65 calibrated light source (with a UV filter to exclude UV light from the light source), and specular reflectance was included in the measurement. Finally, the spectrophotometer data were analyzed using a 10° observer color matching function based on a CIE cool white fluorescent light source. To improve the accuracy of Y-value measurement, the trim panel was measured twice, and the Y-value was taken as the average of the two measurements. The Y-value (Y0) of the white calibration plate of the spectrophotometer was measured using the same setup as when measuring the stacked trim panel. The normalized brightness values ​​(Y′) of each polymer composition are listed in Table 2 below.

[0054] Table 2 shows the blue hue coefficient (α) and normalized brightness value (Y′) of samples 1–7.

[0055] sample Blue hue coefficient (α) Normalized luminance value (Y′) 1 0.86 73.0 2 0.94 72.1 3 1.07 68.7 4 0.92 57.9 5 0.97 70.1 6 0.9 71.8 7 0.98 67.7

[0056] Thin-walled injection-molded cups (0.71 mm (28 mil) wall thickness and approximately 470 ml (16 oz) volume) made from various polymer compositions were then presented to a specialized panel to determine which polymer composition exhibited lower apparent haze. The injection-molded cups were arranged in a stack of ten (all made from the same polymer composition) and observed under diffuse fluorescent illumination to simulate conditions these cups would typically encounter in a retail environment. When the cup made from Sample 2 was presented alongside the cup made from Sample 3, 43 out of 50 specialized panel members considered the cup made from Sample 3 to appear more transparent or exhibit lower apparent haze. When the cup made from Sample 5 was presented alongside the cup made from Sample 7, 20 out of 30 specialized panel members considered the cup made from Sample 7 to appear more transparent or exhibit lower apparent haze. The inventors consider these differences in preference to be statistically significant. Furthermore, the inventors believe that these preferences indicate that polymer compositions exhibiting the values ​​of the blue hue coefficient (α) and normalized brightness value (Y′) as described in the claims and above will be perceived as having lower apparent haze compared to similar polymer compositions that do not exhibit these properties.

[0057] Example 2

[0058] This embodiment demonstrates the preparation of thermoplastic polymer compositions according to the present invention and certain properties of such polymer compositions. Several different polymer compositions were prepared using polypropylene homopolymer resins, specifically LyondellBasell Pro-fax 6301 (HPP6301) polypropylene homopolymer resin. Each polymer composition was prepared by mixing the resin with the components listed in Table 3 below. The polymer compositions were prepared according to the general procedure outlined in Example 1 above. As described in Example 1 above, the polymer compositions were also molded into panels and analyzed. The results of these measurements are shown in Table 4 below.

[0059] Table 3 shows the concentrations of clarifying agent and coloring agent in samples 1-7 of Table 1.

[0060]

[0061]

[0062]

[0063] Table 4 shows the blue hue coefficient (α) and normalized brightness value (Y′) of samples 8–49.

[0064]

[0065]

[0066]

[0067] Based on the findings of the special task force investigation described in Example 1 above, the inventors believe that the samples exhibiting the blue hue coefficient (α) and normalized brightness value (Y′) as described in the claims and above would be perceived as having lower apparent haze compared to similar polymer compositions that do not exhibit these properties.

[0068] All references cited in this article, including publications, patent applications and patents, are incorporated herein by reference to the same extent that each reference is independently and specifically indicated to be incorporated by reference and presented in its entirety in this article.

[0069] Unless otherwise stated herein or obviously contradicted by the context, the terms “a,” “an,” and “the,” and similar indicative terms, used in the context of describing the subject matter of this application (especially in the context of the appended claims), shall be understood to cover both singular and plural forms. Unless otherwise stated, the terms “comprising,” “having,” “including,” and “containing” shall be understood as open-ended terms (i.e., meaning “including, but not limited to”). Unless otherwise stated herein, the numerical ranges listed herein are intended only as a simplified way of referring individually to each independent value falling within that range, and each independent value is incorporated into the specification as if it were set forth separately herein. Unless otherwise stated herein or obviously contradicted by the context, all methods described herein may be performed in any suitable order. Unless otherwise required, the use of any and all instances or exemplary language (e.g., “for example”) provided herein is intended only to better illustrate the subject matter of this application and is not intended to limit the scope of the subject matter. No language in the specification should be construed as indicating that any unclaimed element is essential for the implementation of the subject matter described herein.

[0070] This document describes preferred embodiments of the subject matter of this application, including the best methods known to the inventors for implementing the claimed subject matter. Variations of those preferred embodiments will become apparent to those skilled in the art upon reading the foregoing description. The inventors intend that those skilled in the art will appropriately employ such variations, and that the inventors will implement the subject matter described herein in ways different from those specifically described herein. Therefore, this disclosure includes all modifications and equivalents of the subject matter set forth in the appended claims as permitted by applicable law. Furthermore, unless otherwise stated herein or clearly contradicted by the context, any combination of the foregoing elements in all possible variations is covered by this disclosure.

Claims

1. A thermoplastic polymer composition comprising: (a) a thermoplastic polymer selected from the group consisting of polypropylene homopolymers, polypropylene random copolymers, and mixtures thereof; (b) at least one clarifier; and (c) at least one blue pigment, at least one black pigment, and optionally at least one violet pigment, wherein the amount of clarifier in the thermoplastic polymer composition is from 50 ppm to 5000 ppm, based on the total weight of the thermoplastic polymer composition, and the thermoplastic polymer composition exhibits a blue hue coefficient a of from 0.93 to 1.1 and a normalized lightness value Y' of from 64.0 to 69.

6.

2. The thermoplastic polymer composition of claim 1, wherein the thermoplastic polymer is a polypropylene random copolymer.

3. The thermoplastic polymer composition of claim 1 or 2, wherein the clarifier is selected from the group consisting of triamides, bisphenol phosphates, carboxylates, acetal compounds, and mixtures thereof.

4. The thermoplastic polymer composition of claim 3, wherein the clarifier is an acetal compound conforming to the structure of Formula (I): (I) wherein R1is selected from the group of hydrogen, alkyl group, alkenyl group, hydroxyalkyl group, alkoxy group, haloalkyl group, and derivatives thereof; R2, R3, R4, R5, R6, R7, R8, R9, R 10 and R 11 are each independently selected from the group of hydrogen, alkyl group, alkoxy group, alkenyl group, aryl group, carboxyl group, and halogen; and R 12 is a hydroxyalkyl group selected from -CH2OH and -CH(OH)CH2OH.

5. The thermoplastic polymer composition of claim 4, wherein the clarifying agent is selected from the group consisting of: (a): a compound of formula (I), wherein R1, R2, R3, R4, R5, R6, R7, R8, R9, R 10 and R 11 are each hydrogen, and R 12 is -CH(OH)CH2OH; (b): a compound of formula (I), wherein R1, R2, R3, R5, R6, R7, R8, R 10 and R 11 are each hydrogen, R4and R9are each methyl groups, and R 12 is -CH(OH)CH2OH; (c): a compound of formula (I), wherein R1, R2, R5, R6, R7, R8, and R 11 are each hydrogen, R3, R4, R9, and R 10 are each methyl groups, and R 12 is -CH(OH)CH2OH; and (d): a mixture of at least two of (a), (b), and (c).

6. The thermoplastic polymer composition of claim 4, wherein the clarifying agent is a compound of formula (I), wherein R1, R2, R5, R6, R7, R8, and R 11 are each hydrogen, R3, R4, R9, and R 10 are each methyl groups, and R 12 is -CH(OH)CH2OH.

7. The thermoplastic polymer composition of claim 4, wherein the clarifying agent is a compound of formula (I), wherein R1 is a n-propyl group, R2, R3, R5, R6, R7, R8, R 10 and R 11 are each hydrogen, R 12 is -CH(OH)CH2OH, and R4 and R9 are each a n-propyl group.

8. The thermoplastic polymer composition of claim 1 or 2, wherein the clarifier is present in an amount of from 1000 ppm to 2500 ppm.

9. The thermoplastic polymer composition of claim 1 or 2, wherein the amount of blue pigment, black pigment, and violet pigment in the thermoplastic polymer composition is from 4 to 50 ppm, based on the total weight of the thermoplastic polymer composition.

10. The thermoplastic polymer composition of claim 1 or 2, wherein the black pigment is carbon black.

11. The thermoplastic polymer composition of claim 10, wherein the thermoplastic polymer composition comprises less than 2 ppm of carbon black.

12. The thermoplastic polymer composition of claim 1 or 2, wherein the blue pigment is selected from the group consisting of Pigment Blue 29, Pigment Blue 63, and mixtures thereof.

13. The thermoplastic polymer composition of claim 1 or 2, wherein the thermoplastic polymer composition comprises a violet pigment.

14. The thermoplastic polymer composition of claim 13, wherein the violet pigment is Pigment Violet 15.

15. The thermoplastic polymer composition of claim 1 or 2, wherein the thermoplastic polymer composition comprises from 3.5 to 40 ppm of Pigment Blue 29, from 0 to 5 ppm of Pigment Violet 15, and from 0.25 to 2 ppm of carbon black.

16. The thermoplastic polymer composition of claim 15, wherein the thermoplastic polymer composition comprises from 3.5 to 25 ppm of Pigment Blue 29, from 0 to 4 ppm of Pigment Violet 15, and from 0.25 to 1.75 ppm of carbon black.

17. The thermoplastic polymer composition of claim 16, wherein the total amount of Pigment Blue 29, Pigment Violet 15, and carbon black present in the thermoplastic polymer composition is from 4.75 to 25 ppm.

18. A method for making a thermoplastic polymer composition, the method comprising the steps of: (a) providing a thermoplastic polymer selected from the group consisting of polypropylene homopolymers, polypropylene random copolymers, and mixtures thereof; (b) providing an additive composition comprising: (i) at least one clarifying agent; (ii) at least one blue pigment, at least one black pigment, and optionally at least one violet pigment; and (c) mixing the thermoplastic polymer and the additive composition to produce a thermoplastic polymer composition, wherein the amount of clarifying agent in the thermoplastic polymer composition is from 50 ppm to 5000 ppm, based on the total weight of the thermoplastic polymer composition, and the thermoplastic polymer composition exhibits a blue hue coefficient a of from 0.93 to 1.1 and a normalized brightness value Y' of from 64.0 to 69.

6.

19. The method of claim 18, wherein the thermoplastic polymer is a polypropylene random copolymer.

20. The method of claim 18 or 19, wherein the clarifying agent is selected from the group consisting of triamides, bisphenol phosphates, carboxylates, acetal compounds, and mixtures thereof.

21. The method of claim 20, wherein the clarifying agent is an acetal compound conforming to the structure of Formula (I): (Ⅰ) wherein R1is selected from the group of hydrogen, an alkyl group, an alkenyl group, a hydroxyalkyl group, an alkoxy group, a haloalkyl group, and derivatives thereof; R2, R3, R4, R5, R6, R7, R8, R9, R 10 and R 11 are each independently selected from the group of hydrogen, an alkyl group, an alkoxy group, an alkenyl group, an aryl group, a carboxyl group, and a halogen; and R 12 is a hydroxyalkyl group selected from the group of -CH2OH and -CH(OH)CH2OH.

22. The method according to claim 21, wherein the clarifying agent is selected from the group consisting of: (a): compounds of formula (I), wherein R1, R2, R3, R4, R5, R6, R7, R8, R9, R 10 and R 11 All are hydrogen, and R 12 (a) : CH(OH)CH2OH; (b) : Compounds of formula (I), wherein R1, R2, R3, R5, R6, R7, R8, R 10 and R 11 All are hydrogen, R4 and R9 are both methyl groups, and R 12 (c) : Compounds of formula (I), wherein R1, R2, R5, R6, R7, R8 and R 11 All are hydrogen, R3, R4, R9 and R 10 All are methyl groups, and R 12 (a) is ─CH(OH)CH2OH; and (d) is a mixture of at least two of (a), (b) and (c).

23. The method of claim 21, wherein the clarifying agent is a compound of formula (I), wherein R1, R2, R5, R6, R7, R8, and R 11 are each hydrogen, R3, R4, R9, and R 10 are each methyl groups, and R 12 is -CH(OH)CH2OH.

24. The method of claim 21, wherein the clarifying agent is a compound of formula (I), wherein R1is a n-propyl group, R2, R3, R5, R6, R7, R8, R 10 and R 11 are each hydrogen, R 12 is -CH(OH)CH2OH, and R4and R9are each a n-propyl group.

25. The method of claim 18 or 19, wherein the clarifying agent is present in an amount of from 1000 ppm to 2500 ppm.

26. The method of claim 18 or 19, wherein the amount of blue pigment, black pigment, and violet pigment in the thermoplastic polymer composition is from 4 to 50 ppm, based on the total weight of the thermoplastic polymer composition.

27. The method of claim 18 or 19, wherein the black pigment is carbon black.

28. The method of claim 27, wherein the thermoplastic polymer composition comprises less than 2 ppm of carbon black.

29. The method of claim 18 or 19, wherein the blue pigment is selected from the group consisting of Pigment Blue 29, Pigment Blue 63, and mixtures thereof.

30. The method of claim 18 or 19, wherein the thermoplastic polymer composition comprises a violet pigment.

31. The method of claim 30, wherein the violet pigment is Pigment Violet 15.

32. The method of claim 18 or 19, wherein the thermoplastic polymer composition comprises from 3.5 to 40 ppm of Pigment Blue 29, from 0 to 5 ppm of Pigment Violet 15, and from 0.25 to 2 ppm of carbon black.

33. The method of claim 32, wherein the thermoplastic polymer composition comprises from 3.5 to 25 ppm of Pigment Blue 29, from 0 to 4 ppm of Pigment Violet 15, and from 0.25 to 1.75 ppm of carbon black.

34. The method of claim 33, wherein the total amount of Pigment Blue 29, Pigment Violet 15, and carbon black present in the thermoplastic polymer composition is from 4.75 to 25 ppm.

35. A method for producing a thermoplastic polymer composition, the method comprising the steps of: (a) providing a thermoplastic polymer selected from the group consisting of polypropylene homopolymers, polypropylene random copolymers, and mixtures thereof; (b) providing at least one clarifying agent; (c) providing at least one blue pigment, at least one black pigment, and optionally providing at least one violet pigment; and (d) mixing the thermoplastic polymer, the clarifying agent, and the blue pigment, black pigment, and optionally the violet pigment to produce a thermoplastic polymer composition, wherein the amount of clarifying agent present in the thermoplastic polymer composition is from 100 ppm to 5000 ppm, based on the total weight of the thermoplastic polymer composition, and the thermoplastic polymer composition exhibits a blue hue coefficient a of from 0.93 to 1.1 and a normalized lightness value Y' of from 64.0 to 69.

6.

36. The method of claim 35, wherein the thermoplastic polymer is a polypropylene random copolymer.

37. The method of claim 35 or 36, wherein the clarifying agent is selected from the group consisting of triamides, bisphenol phosphates, carboxylates, acetal compounds, and mixtures thereof.

38. The method of claim 37, wherein the clarifying agent is an acetal compound conforming to the structure of Formula (I): (Ⅰ) wherein R1is selected from the group of hydrogen, alkyl group, alkenyl group, hydroxyalkyl group, alkoxy group, haloalkyl group, and derivatives thereof; R2, R3, R4, R5, R6, R7, R8, R9, R 10 and R 11 are each independently selected from the group of hydrogen, alkyl group, alkoxy group, alkenyl group, aryl group, carboxyl group, and halogen; and R 12 is a hydroxyalkyl group selected from -CH2OH and -CH(OH)CH2OH.

39. The method of claim 38, wherein the clarifying agent is selected from the group consisting of: (a): a compound of formula (I), wherein R1, R2, R3, R4, R5, R6, R7, R8, R9, R 10 and R 11 are each hydrogen, and R 12 is -CH(OH)CH2OH; (b): a compound of formula (I), wherein R1, R2, R3, R5, R6, R7, R8, R 10 and R 11 are each hydrogen, R4and R9are each methyl groups, and R 12 is -CH(OH)CH2OH; (c): a compound of formula (I), wherein R1, R2, R5, R6, R7, R8, and R 11 are each hydrogen, R3, R4, R9, and R 10 are each methyl groups, and R 12 is -CH(OH)CH2OH; and (d): a mixture of at least two of (a), (b), and (c).

40. The method of claim 38, wherein the clarifying agent is a compound of Formula (I), wherein R1, R2, R5, R6, R7, R8, and R 11 are each hydrogen, R3, R4, R9, and R 10 are each methyl groups, and R 12 is -CH(OH)CH2OH.

41. The method of claim 38, wherein the clarifying agent is a compound of Formula (I), wherein R1is a n-propyl group, R2, R3, R5, R6, R7, R8, R 10 and R 11 are each hydrogen, R 12 is -CH(OH)CH2OH, and R4and R9are each a n-propyl group.

42. The method of claim 35 or 36, wherein the clarifying agent is present in an amount of from 1000 ppm to 2500 ppm.

43. The method of claim 35 or 36, wherein the amount of blue pigment, black pigment, and violet pigment in the thermoplastic polymer composition is from 4 to 50 ppm, based on the total weight of the thermoplastic polymer composition.

44. The method of claim 35 or 36, wherein the black pigment is carbon black.

45. The method of claim 44, wherein the thermoplastic polymer composition comprises less than 2 ppm of carbon black.

46. The method of claim 35 or 36, wherein the blue pigment is selected from the group consisting of Pigment Blue 29, Pigment Blue 63, and mixtures thereof.

47. The method of claim 35 or 36, wherein the thermoplastic polymer composition comprises a violet pigment.

48. The method of claim 47, wherein the violet pigment is Pigment Violet 15.

49. The method of claim 35 or 36, wherein the thermoplastic polymer composition comprises from 3.5 to 40 ppm of Pigment Blue 29, from 0 to 5 ppm of Pigment Violet 15, and from 0.25 to 2 ppm of carbon black.

50. The method of claim 49, wherein the thermoplastic polymer composition comprises from 3.5 to 25 ppm of Pigment Blue 29, from 0 to 4 ppm of Pigment Violet 15, and from 0.25 to 1.75 ppm of carbon black.

51. The method of claim 50, wherein the total amount of Pigment Blue 29, Pigment Violet 15, and carbon black present in the thermoplastic polymer composition is from 4.75 to 25 ppm.

52. An additive composition consisting essentially of: (a) at least one clarifying agent; and 53. The additive composition of claim 52, wherein the clarifying agent is an acetal compound conforming to the structure of Formula (I):

54. The additive composition of claim 52 or 53, wherein the additive composition further comprises at least one blue pigment, at least one black pigment, and optionally at least one violet pigment.

55. The additive composition of claim 54, wherein the additive composition further comprises from 4 to 50 ppm of blue pigment, black pigment, and violet pigment, based on the total weight of the additive composition. (b) at least one blue pigment, at least one black pigment, and optionally at least one violet pigment, wherein the thermoplastic polymer composition exhibits a blue hue factor a of 0.93 to 1.1 and a normalized brightness value Y' of 64.0 to 69.6 when the additive composition is added to the thermoplastic polymer in an amount to provide 100 to 5000 ppm of the clarifying agent in the thermoplastic polymer composition.

53. The additive composition of claim 52, wherein the clarifying agent is selected from the group consisting of triamides, bisphenol phosphates, carboxylates, acetal compounds, and mixtures thereof.

54. The additive composition of claim 53, wherein the clarifying agent is an acetal compound conforming to the structure of Formula (I): (Ⅰ) wherein R1is selected from the group of hydrogen, an alkyl group, an alkenyl group, a hydroxyalkyl group, an alkoxy group, a haloalkyl group, and derivatives thereof; R2, R3, R4, R5, R6, R7, R8, R9, R 10 and R 11 are each independently selected from the group of hydrogen, an alkyl group, an alkoxy group, an alkenyl group, an aryl group, a carboxyl group, and a halogen; and R 12 is a hydroxyalkyl group selected from the group of -CH2OH and -CH(OH)CH2OH.

55. The additive composition of claim 54, wherein the clarifying agent is selected from the group consisting of: (a): a compound of formula (I), wherein R1, R2, R3, R4, R5, R6, R7, R8, R9, R 10 and R 11 are each hydrogen, and R 12 is -CH(OH)CH2OH; (b): a compound of formula (I), wherein R1, R2, R3, R5, R6, R7, R8, R 10 and R 11 are each hydrogen, R4and R9are each methyl groups, and R 12 is -CH(OH)CH2OH; (c): a compound of formula (I), wherein R1, R2, R5, R6, R7, R8, and R 11 are each hydrogen, R3, R4, R9, and R 10 are each methyl groups, and R 12 is -CH(OH)CH2OH; and (d): a mixture of at least two of (a), (b), and (c).

56. The additive composition of claim 54, wherein the clarifying agent is a compound of Formula (I), wherein R1, R2, R5, R6, R7, R8, and R 11 are each hydrogen, R3, R4, R9, and R 10 are each methyl groups, and R 12 is -CH(OH)CH2OH.

57. The additive composition of claim 54, wherein the clarifying agent is a compound of Formula (I), wherein R1 is a n-propyl group, R2, R3, R5, R6, R7, R8, R 10 and R 11 are each hydrogen, R 12 is -CH(OH)CH2OH, and R4 and R9 are each a n-propyl group.

58. The additive composition of any one of claims 52 to 57, wherein the amount of blue pigment, black pigment, and violet pigment in the additive composition is 4 to 50 ppm when the additive composition is added to the thermoplastic polymer in an amount to provide 100 to 5000 ppm of the clarifying agent in the thermoplastic polymer composition.

59. The additive composition of any one of claims 52 to 57, wherein the black pigment is carbon black.

60. The additive composition of claim 59, wherein the thermoplastic polymer composition comprises less than 2 ppm of carbon black when the additive composition is added to the thermoplastic polymer in an amount to provide 100 to 5000 ppm of the clarifying agent in the thermoplastic polymer composition.

61. The additive composition of any one of claims 52 to 57, wherein the blue pigment is selected from the group consisting of Pigment Blue 29, Pigment Blue 63, and mixtures thereof.

62. The additive composition of any one of claims 52 to 57, wherein the thermoplastic polymer composition comprises a violet pigment.

63. The additive composition of claim 62, wherein the violet pigment is Pigment Violet 15.

64. The additive composition of any one of claims 52 to 57, wherein the thermoplastic polymer composition comprises 3.5 to 40 ppm of Pigment Blue 29, 0 to 5 ppm of Pigment Violet 15, and 0.25 to 2 ppm of carbon black when the additive composition is added to the thermoplastic polymer in an amount to provide 100 to 5000 ppm of the clarifying agent in the thermoplastic polymer composition.

65. The additive composition of claim 64, wherein the thermoplastic polymer composition comprises 3.5 to 25 ppm of Pigment Blue 29, 0 to 4 ppm of Pigment Violet 15, and 0.25 to 1.75 ppm of carbon black.

66. The additive composition of claim 65, wherein the total amount of Pigment Blue 29, Pigment Violet 15, and carbon black present in the thermoplastic polymer composition is 4.75 to 25 ppm.

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