Toughened PMMA color master batch and preparation method thereof

Abstract

The application discloses a kind of toughened PMMA color master batch and preparation method thereof, the color master batch is made of PMMA carrier resin, color powder, impact modifier, dispersing agent and processing aid.PMMA carrier resin is divided into first PMMA carrier resin and second PMMA carrier resin, color powder, dispersing agent and first PMMA carrier resin are placed in first mixing space to form colored pre-dispersion, impact modifier, processing aid and second PMMA carrier resin are placed in second mixing space isolated from first mixing space to form toughening pre-dispersion;Before two kinds of pre-dispersion are formed respectively, material transfer is not carried out between two mixing spaces, after two are formed respectively, melt blending, extrusion, cooling and pelletizing are carried out after being combined.The method can improve the coloring consistency of color master batch, impact resistance, and has good toughening effect.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, and in particular to a toughened PMMA masterbatch and its preparation method. Background Technology

[0002] Polymethyl methacrylate (PMMA) is characterized by good light transmittance, high surface gloss, good weather resistance, and ease of coloring. It is widely used in automotive interior and exterior trim, household appliance housings, lighting components, decorative panels, and display panels. To achieve the desired color in PMMA products, colorants, PMMA carriers, and processing aids are typically formulated into masterbatches. These masterbatches are then mixed with the PMMA base material before injection molding or extrusion molding.

[0003] Patent CN105273349A discloses a black masterbatch for polymethyl methacrylate (PMMA) and its preparation method. The method involves mixing PMMA, solvent red, solvent yellow, solvent blue, and antioxidants, followed by melt extrusion granulation to improve the blackness, dispersibility, gloss, and processing performance of the masterbatch. This technology primarily improves the coloring effect of the PMMA masterbatch through the compounding of dye components, but it does not form a toughening system within the masterbatch that enhances the impact resistance of the final PMMA product. Therefore, it is difficult to simultaneously meet the coloring and toughening requirements of PMMA products.

[0004] For example, patent CN101870794A discloses a transparent toughened PMMA material and its preparation method. This method involves mixing PMMA, a compound toughening agent, a lubricant, and an antioxidant, followed by melt extrusion. The toughening agent improves the impact resistance of the PMMA material, and the selection of the toughening agent balances material transparency and processing fluidity. This technology directly disperses the toughening agent in the PMMA material, without addressing the co-dispersion of high-concentration coloring components and toughening components in the masterbatch carrier. When this toughening method is directly applied to PMMA masterbatches, the coloring and toughening components are prone to uneven distribution due to differences in surface properties and melt dispersion characteristics, leading to fluctuations in the coloring and toughening effects of the masterbatch.

[0005] Therefore, how to ensure the color consistency and impact resistance of the masterbatch in a PMMA masterbatch system containing both coloring components and impact modifiers, and thus achieve a toughening effect, is a technical problem that needs to be solved by existing technologies. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the technical problem this invention aims to solve is to provide a toughened PMMA masterbatch and its preparation method, ensuring color consistency and impact resistance of the masterbatch, thereby achieving a toughening effect. To solve the above technical problem, this invention provides the following technical solution: The first aspect of this application relates to a toughened PMMA masterbatch, which is made of PMMA carrier resin, color powder, impact modifier, dispersant and processing aid; The PMMA carrier resin includes a first PMMA carrier resin and a second PMMA carrier resin. The color powder and the dispersant are dispersed in the first PMMA carrier resin to form a coloring pre-dispersed material. The impact modifier and the processing aid are dispersed in the second PMMA carrier resin to form a toughening pre-dispersed material. The coloring pre-dispersed material and the toughening pre-dispersed material are melt-blended to form the toughening PMMA masterbatch.

[0007] Furthermore, based on the total mass of the raw materials used to prepare the toughened PMMA masterbatch, the toughened PMMA masterbatch is made from the following components in weight percentages: 60-78% PMMA carrier resin, 8-16% color powder, 12-20% impact modifier, 1-2.5% dispersant, and 1-1.5% processing aid, with the sum of the weight percentages of each component being 100%.

[0008] Furthermore, the mass ratio of the first PMMA carrier resin to the second PMMA carrier resin is 1:(1.5~3).

[0009] Furthermore, the impact modifier is one of acrylic rubber copolymers and acrylate core-shell structure impact modifiers.

[0010] Furthermore, the pigment includes one or more of organic and inorganic pigments.

[0011] Furthermore, the organic pigments include one or more of azo pigments, phthalocyanine pigments, and polycyclic aromatic hydrocarbon pigments, and the inorganic pigments include one or more of titanium dioxide, carbon black, ultramarine, and iron oxide pigments.

[0012] Furthermore, the dispersant is polyethylene wax.

[0013] Furthermore, the processing aids include antioxidants and lubricants; the antioxidants include one or more of hindered phenolic antioxidants and phosphite antioxidants, and the lubricants include one or more of pentaerythritol tetrastearate, ethylene bis-stearamide, and magnesium stearate.

[0014] A second aspect of this application relates to a method for preparing toughened PMMA masterbatch, used to prepare the toughened PMMA masterbatch described in any of the above claims, comprising the following steps: After weighing each component according to the weight formula, the PMMA carrier resin and impact modifier are dried. The dried PMMA carrier resin is divided into a first PMMA carrier resin and a second PMMA carrier resin. The color powder, the dispersant, and the first PMMA carrier resin are placed in a first mixing space and mixed to disperse the color powder in the first PMMA carrier resin, thereby obtaining a coloring pre-dispersed material. The impact modifier, the processing aid, and the second PMMA carrier resin are placed in a second mixing space that is isolated from the first mixing space and mixed to disperse the impact modifier in the second PMMA carrier resin, thereby obtaining a toughened pre-dispersion. Before the coloring predispersant and the toughening predispersant are formed, no material transfer is performed between the first mixing space and the second mixing space. After they are formed, they are combined and melt-blended, extruded, cooled and pelletized to obtain toughened PMMA color masterbatch.

[0015] Furthermore, the melt blending and extrusion are carried out using a twin-screw extruder, and the temperature of each heating zone in the melt blending section of the twin-screw extruder is 185–225°C.

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention separates PMMA carrier resin into a first PMMA carrier resin and a second PMMA carrier resin. Pigment and dispersant form a coloring pre-dispersion in a first mixing space, while impact modifier and processing aid form a toughening pre-dispersion in a separate second mixing space. After the two pre-dispersions are formed separately, they are combined and melt-blended. Compared to methods that involve mixing all raw materials at once, sequentially mixing within the same mixing space, or forming only one type of pre-dispersion independently, this preparation method reduces color difference between the resulting masterbatch samples and improves the coloring consistency of the masterbatch.

[0017] 2. This invention, based on the addition of an impact modifier to the raw material formulation, involves separately forming the coloring pre-dispersion and the toughening pre-dispersion before melt blending. Comparative test results show that, under the same raw material composition, raw material dosage, and subsequent processing conditions, the notched impact strength of the sample obtained using the above preparation method is higher than that of samples obtained by single mixing, sequential mixing within the same mixing space, and forming only one type of pre-dispersion. This simultaneously improves the color consistency and notched impact performance of the masterbatch, achieving a toughening effect. Attached Figure Description

[0018] Figure 1 This is a schematic flowchart of a method for preparing toughened PMMA masterbatch according to an embodiment of the present invention. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions in the embodiments of this invention will be described more clearly and completely below. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0020] In this embodiment of the invention, the weight percentage of each component is based on the total mass of the raw materials used to prepare the toughened PMMA masterbatch. When each component is selected within the corresponding weight percentage range, the specific dosage of each component is determined to ensure that the sum of the weight percentages of the PMMA carrier resin, color powder, impact modifier, dispersant, and processing aid is 100%.

[0021] This application adopts a formulation function classification and measurement method. Each raw material is measured according to its functional component in the formulation of this application, and the same raw material is not measured repeatedly in different functional components. Polyethylene wax is classified as a dispersant, and its entire weight is included in the dispersant content, not the processing aid content. Processing aids include antioxidants and lubricants. The weights of antioxidant 1010 and antioxidant 168 are included in the processing aid content. Pentaerythritol tetrastearate, ethylene bis-stearamide, and magnesium stearate are used as lubricants, and their weights are also included in the processing aid content. Therefore, the amount of processing aids in each embodiment is the sum of the amounts of antioxidants and lubricants.

[0022] In this embodiment of the invention, the formation of the coloring predispersant and the toughening predispersant is determined by the completion of the corresponding mixing process. After adding the colorant, dispersant, and first PMMA carrier resin to a first high-speed mixer, they are continuously mixed at 70°C for 10 minutes. The coloring predispersant is determined to have formed when the mixing time is completed. Similarly, after adding the impact modifier, processing aid, and second PMMA carrier resin to a second high-speed mixer, they are continuously mixed at 60°C for 8 minutes. The toughening predispersant is determined to have formed when the mixing time is completed. No material transfer occurs between the first and second high-speed mixers before the corresponding mixing times for both predispersants are completed. After both predispersants have completed their corresponding mixing times, the coloring predispersant and the toughening predispersant are discharged from their respective high-speed mixers, combined, and then fed into a twin-screw extruder for melt blending. This embodiment uses the completion of a specified mixing temperature and time as the operational boundary for determining the formation of the predispersant and subsequent material merging.

[0023] Example 1: The raw materials for preparing the color masterbatch in this embodiment include the following components by weight percentage: PMMA carrier resin 78%, color powder 8%, impact modifier 12%, polyethylene wax 1%, and processing aid 1%.

[0024] Based on a total raw material mass of 100kg, weigh the following raw materials: 78kg PMMA carrier resin, 8kg carbon black, 12kg acrylate core-shell structure impact modifier, 1kg polyethylene wax, 0.3kg antioxidant 1010, 0.2kg antioxidant 168, and 0.5kg pentaerythritol tetrastearate (PETS).

[0025] The PMMA carrier resin was dried at 80°C for 4 hours, and the acrylate core-shell impact modifier was dried at 70°C for 3 hours. After drying, the PMMA carrier resin was divided into 31.2 kg of first PMMA carrier resin and 46.8 kg of second PMMA carrier resin.

[0026] Carbon black, polyethylene wax, and the first PMMA carrier resin were added to a first high-speed mixer and mixed at 70°C for 10 minutes to obtain a colored pre-dispersed material. Acrylic core-shell impact modifier, antioxidant 1010, antioxidant 168, PETS, and the second PMMA carrier resin were added to a second high-speed mixer and mixed at 60°C for 8 minutes to obtain a toughened pre-dispersed material. After the two pre-dispersed materials were formed separately, they were mixed and fed into a twin-screw extruder for melt blending. The temperature of each heating zone in the melt blending section of the twin-screw extruder was 185–225°C, the screw speed was 240 rpm, and the gauge pressure at the vacuum exhaust port was -0.08 MPa. After cooling and pelletizing, the extrudate was dried at 80°C for 3 hours to obtain toughened PMMA masterbatch.

[0027] Example 2: The raw materials for preparing the color masterbatch in this embodiment include the following components by weight percentage: PMMA carrier resin 72%, color powder 12%, impact modifier 14%, polyethylene wax 1%, and processing aid 1%.

[0028] Based on a total raw material mass of 100kg, weigh the following raw materials: 72kg PMMA carrier resin, 12kg carbon black, 14kg acrylate core-shell structure impact modifier, 1kg polyethylene wax, 0.3kg antioxidant 1010, 0.2kg antioxidant 168, and 0.5kg ethylene bis-stearamide (EBS).

[0029] The PMMA carrier resin was dried at 80°C for 4 hours, and the acrylate core-shell impact modifier was dried at 70°C for 3 hours. After drying, the PMMA carrier resin was divided into 24 kg of first PMMA carrier resin and 48 kg of second PMMA carrier resin.

[0030] Carbon black, polyethylene wax, and the first PMMA carrier resin were added to a first high-speed mixer and mixed at 70°C for 10 minutes to obtain a colored pre-dispersed material. An acrylate core-shell impact modifier, antioxidant 1010, antioxidant 168, EBS, and the second PMMA carrier resin were added to a second high-speed mixer and mixed at 60°C for 8 minutes to obtain a toughened pre-dispersed material. After the two pre-dispersed materials were formed separately, they were mixed and fed into a twin-screw extruder for melt blending. The temperature of each heating zone in the melt blending section of the twin-screw extruder was 185–225°C, the screw speed was 240 rpm, and the gauge pressure at the vacuum exhaust port was -0.08 MPa. After cooling and pelletizing, the extrudate was dried at 80°C for 3 hours to obtain toughened PMMA masterbatch.

[0031] Example 3: The raw materials for preparing the color masterbatch in this embodiment include the following components by weight percentage: 60% PMMA carrier resin, 16% color powder, 20% impact modifier, 2.5% polyethylene wax, and 1.5% processing aid.

[0032] Based on a total raw material mass of 100kg, weigh the following raw materials: 60kg PMMA carrier resin, 16kg titanium dioxide, 20kg acrylic rubber copolymer, 2.5kg polyethylene wax, 0.45kg antioxidant 1010, 0.3kg antioxidant 168, 0.6kg PETS, and 0.15kg magnesium stearate.

[0033] The PMMA carrier resin was dried at 80°C for 4 hours, and the acrylic rubber copolymer was dried at 70°C for 3 hours. After drying, the PMMA carrier resin was divided into 15 kg of first PMMA carrier resin and 45 kg of second PMMA carrier resin.

[0034] Titanium dioxide, polyethylene wax, and the first PMMA carrier resin were added to a first high-speed mixer and mixed at 70°C for 10 minutes to obtain a colored pre-dispersed material. Acrylic rubber copolymer, antioxidant 1010, antioxidant 168, PETS, magnesium stearate, and the second PMMA carrier resin were added to a second high-speed mixer and mixed at 60°C for 8 minutes to obtain a toughened pre-dispersed material. After the two pre-dispersed materials were formed separately, they were mixed and fed into a twin-screw extruder for melt blending. The temperature of each heating zone in the melt blending section of the twin-screw extruder was 185–225°C, the screw speed was 240 rpm, and the gauge pressure at the vacuum exhaust port was -0.08 MPa. After cooling and pelletizing, the extrudate was dried at 80°C for 3 hours to obtain toughened PMMA masterbatch.

[0035] Example 4: The raw materials for preparing the color masterbatch in this embodiment include the following components by weight percentage: 68% PMMA carrier resin, 10% color powder, 18% impact modifier, 2.5% polyethylene wax, and 1.5% processing aid.

[0036] Based on a total raw material mass of 100kg, weigh the following raw materials: 68kg PMMA carrier resin, 10kg phthalocyanine blue pigment, 18kg acrylate core-shell structure impact modifier, 2.5kg polyethylene wax, 0.5kg antioxidant 1010, 0.3kg antioxidant 168, and 0.7kg EBS.

[0037] The PMMA carrier resin was dried at 80°C for 4 hours, and the acrylate core-shell impact modifier was dried at 70°C for 3 hours. After drying, the PMMA carrier resin was divided into 20 kg of first PMMA carrier resin and 48 kg of second PMMA carrier resin.

[0038] Phthalocyanine blue pigment, polyethylene wax, and the first PMMA carrier resin were added to a first high-speed mixer and mixed at 70°C for 10 minutes to obtain a colored pre-dispersed material. Acrylic core-shell impact modifier, antioxidant 1010, antioxidant 168, EBS, and the second PMMA carrier resin were added to a second high-speed mixer and mixed at 60°C for 8 minutes to obtain a toughened pre-dispersed material. After the two pre-dispersed materials were formed separately, they were mixed and fed into a twin-screw extruder for melt blending. The temperature of each heating zone in the melt blending section of the twin-screw extruder was 185–225°C, the screw speed was 240 rpm, and the gauge pressure at the vacuum exhaust port was -0.08 MPa. After cooling and pelletizing, the extrudate was dried at 80°C for 3 hours to obtain toughened PMMA masterbatch.

[0039] Example 5: The raw materials for preparing the color masterbatch in this embodiment include the following components by weight percentage: PMMA carrier resin 72.5%, color powder 8%, impact modifier 16%, polyethylene wax 2%, and processing aid 1.5%.

[0040] Based on a total raw material mass of 100kg, weigh the following raw materials: PMMA carrier resin 72.5kg, iron oxide red pigment 8kg, acrylic rubber copolymer 16kg, polyethylene wax 2kg, antioxidant 1010 0.45kg, antioxidant 168 0.3kg, PETS 0.6kg, and magnesium stearate 0.15kg.

[0041] The PMMA carrier resin was dried at 80°C for 4 hours, and the acrylic rubber copolymer was dried at 70°C for 3 hours. After drying, the PMMA carrier resin was divided into 29 kg of first PMMA carrier resin and 43.5 kg of second PMMA carrier resin.

[0042] Iron oxide red pigment, polyethylene wax, and the first PMMA carrier resin were added to a first high-speed mixer and mixed at 70°C for 10 minutes to obtain a colored pre-dispersed material. Acrylic rubber copolymer, antioxidant 1010, antioxidant 168, PETS, magnesium stearate, and the second PMMA carrier resin were added to a second high-speed mixer and mixed at 60°C for 8 minutes to obtain a toughened pre-dispersed material. After the two pre-dispersed materials were formed separately, they were mixed and fed into a twin-screw extruder for melt blending. The temperature of each heating zone in the melt blending section of the twin-screw extruder was 185–225°C, the screw speed was 240 rpm, and the gauge pressure at the vacuum exhaust port was -0.08 MPa. After cooling and pelletizing, the extrudate was dried at 80°C for 3 hours to obtain toughened PMMA masterbatch.

[0043] Example 6: The raw materials for preparing the color masterbatch in this embodiment include the following components by weight percentage: 64% PMMA carrier resin, 14% color powder, 19% impact modifier, 1.5% polyethylene wax, and 1.5% processing aid.

[0044] Based on a total raw material mass of 100kg, weigh the following raw materials: 64kg PMMA carrier resin, 14kg azo yellow pigment, 19kg acrylate core-shell structure impact modifier, 1.5kg polyethylene wax, 0.5kg antioxidant 1010, 0.3kg antioxidant 168, and 0.7kg PETS.

[0045] The PMMA carrier resin was dried at 80°C for 4 hours, and the acrylate core-shell impact modifier was dried at 70°C for 3 hours. After drying, the PMMA carrier resin was divided into 16 kg of first PMMA carrier resin and 48 kg of second PMMA carrier resin.

[0046] Azo yellow pigment, polyethylene wax, and the first PMMA carrier resin were added to a first high-speed mixer and mixed at 70°C for 10 minutes to obtain a colored pre-dispersed material. An acrylate core-shell impact modifier, antioxidant 1010, antioxidant 168, PETS, and the second PMMA carrier resin were added to a second high-speed mixer and mixed at 60°C for 8 minutes to obtain a toughened pre-dispersed material. After the two pre-dispersed materials were formed separately, they were mixed and fed into a twin-screw extruder for melt blending. The temperature of each heating zone in the melt blending section of the twin-screw extruder was 185–225°C, the screw speed was 240 rpm, and the gauge pressure at the vacuum exhaust port was -0.08 MPa. After cooling and pelletizing, the extrudate was dried at 80°C for 3 hours to obtain toughened PMMA masterbatch.

[0047] Comparative Example 1: The difference between this comparative example and Example 2 is that, instead of preparing separate coloring pre-dispersion and toughening pre-dispersion, the dried PMMA carrier resin, carbon black, acrylate core-shell impact modifier, polyethylene wax, antioxidant 1010, antioxidant 168, and EBS are simultaneously added to the same high-speed mixer and mixed at 65°C for 18 minutes to obtain a single mixture. Apart from the above differences, the types and amounts of raw materials, and preparation conditions are the same as in Example 2.

[0048] Comparative Example 2: The difference between this comparative example and Example 2 is that the coloring system and toughening system are mixed sequentially in the same high-speed mixer. First, carbon black, polyethylene wax, and the first PMMA carrier resin are mixed at 70°C for 10 minutes. Without removing the resulting mixture, an acrylate core-shell impact modifier, antioxidant 1010, antioxidant 168, EBS, and the second PMMA carrier resin are added, and the mixture is further mixed at 60°C for 8 minutes to obtain the sequential mixture. Except for the above differences, the types and amounts of raw materials, and the preparation conditions are the same as in Example 2.

[0049] Comparative Example 3: The difference between this comparative example and Example 2 is that only the coloring pre-dispersion is prepared, and the toughening pre-dispersion is not prepared independently. Carbon black, polyethylene wax, and the first PMMA carrier resin are mixed according to the method of Example 2 to obtain the coloring pre-dispersion; the acrylate core-shell structure impact modifier, antioxidant 1010, antioxidant 168, EBS, and the second PMMA carrier resin are directly added to the coloring pre-dispersion and mixed. Except for the above differences, the types and amounts of raw materials, and the preparation conditions are the same as in Example 2.

[0050] Comparative Example 4: The difference between this comparative example and Example 2 is that only the toughening pre-dispersion is prepared, and the coloring pre-dispersion is not prepared independently. The acrylate core-shell impact modifier, antioxidant 1010, antioxidant 168, EBS, and the second PMMA carrier resin are mixed according to the method of Example 2 to obtain the toughening pre-dispersion; carbon black, polyethylene wax, and the first PMMA carrier resin are directly added to the toughening pre-dispersion and mixed. Except for the above differences, the types and amounts of raw materials, and the preparation conditions are the same as in Example 2.

[0051] Comparative Example 5: The difference between this comparative example and Example 2 is that no acrylate core-shell structure impact modifier is added, and an equal mass of PMMA carrier resin is used to make up to 100% of the total mass of the raw materials.

[0052] Test example: The toughened PMMA masterbatches prepared in the examples and comparative examples were dried at 80°C for 3 hours. After drying, each set of masterbatches was not diluted with other PMMA base materials and was directly added to the same injection molding machine. Color difference test specimens and notched impact test specimens were prepared under the same injection molding conditions. The injection molding machine's barrel temperature was 200°C at the rear, 210°C at the middle, 220°C at the front, and 220°C at the nozzle. The mold temperature was 60°C, the injection pressure was 70 MPa, the holding pressure was 45 MPa, the holding time was 10 seconds, and the cooling time was 20 seconds. Each time a set of masterbatches was changed, the barrel was first cleaned with the corresponding masterbatch. Test specimens were prepared only after the color of the continuously injected samples stabilized, to reduce the influence of residual material in the barrel on the test results.

[0053] Color difference testing between sample panels: A Minolta CM-3600A colorimeter was used for testing. The testing conditions included a D65 standard light source, a 10° standard observer angle, an 8mm measuring aperture, and specular reflection mode. Five color difference test samples (100mm × 100mm × 2mm) were prepared for each group. Each sample was placed in an environment with a temperature of 23℃ and a relative humidity of 50% for 24 hours. A test point was set at the center, four corners, and the middle of each of the four sides of each color difference test sample, for a total of nine test points. Measurements were taken at each test point. , and The average color value of the sample was determined by taking the average of the nine test points. The average color value of the five samples in the same group was taken as the unified reference color value for that group. The CIELAB color difference ΔE between the average color value of each sample and the unified reference color value was calculated, and the relationship was as follows: ; In the formula, The difference in lightness between the average color value of the sample under test and the uniform reference color value. The red-green axis chromaticity difference between the average color value of the sample under test and the uniform reference color value. The difference in chromaticity along the yellow-blue axis between the average color value of the sample to be tested and the uniform reference color value.

[0054] Notched impact strength test: Notched impact strength was tested according to GB / T 1043.1-2008 "Determination of impact properties of simply supported beams of plastics - Part 1: Non-instrumental impact testing". Ten notched impact test specimens (80mm × 10mm × 4mm) were prepared for each group of masterbatch. A type A notch was machined into the width of the specimen, leaving an 8mm width at the notch. Each specimen was placed in an environment of 23℃ and 50% relative humidity for 24 hours before testing. The notched impact strength of each specimen was recorded, and the average and standard deviation of the ten specimens in the same group were calculated.

[0055] Table 1 As shown in Table 1, the average color difference of Examples 1 to 6 is 0.22 to 0.34, and the notched impact strength is 8.9 to 13.6 kJ / m. 2 The results indicate that, within a given range of raw material content, pigment type, impact modifier type, and mass ratio of the first PMMA carrier resin to the second PMMA carrier resin, forming color pre-dispersion and toughening pre-dispersion separately before melt blending can reduce color differences between different color difference test samples in the same group and improve the color consistency of the obtained masterbatch.

[0056] The notched impact strength of Examples 1 through 6 varied with the content of the impact modifier, the type and content of the pigment. Specifically, the notched impact strength of Example 2 was 10.8 ± 0.5 kJ / m. 2 Under the same raw material composition and dosage as Comparative Examples 1-4, the notched impact strength of the sample was higher than that of Comparative Examples 1-4, and the standard deviation of the test results was lower than that of Comparative Examples 1-3. These results indicate that, under the same raw material composition and dosage, forming coloring pre-dispersion and toughening pre-dispersion separately followed by melt blending, corresponding to the higher notched impact strength and smaller fluctuations in the test results of the resulting masterbatch molded sample, can improve the notched impact performance.

[0057] Example 2 used the same raw material types, amounts, drying conditions, extrusion conditions, injection molding conditions, and testing conditions as Comparative Examples 1-4, the difference being the method by which each raw material was formed into a pre-dispersion. The average color difference of Example 2 was 0.22, which was reduced by 71.8%, 60.7%, 29.0%, and 68.1% compared to Comparative Examples 1, 2, 3, and 4, respectively; the notched impact strength of Example 2 was 10.8 kJ / m². 2 Compared with Comparative Examples 1, 2, 3, and 4, the results showed improvements of 50.0%, 33.3%, 35.0%, and 14.9%, respectively. These results indicate that simultaneously and independently forming the coloring pre-dispersion and toughening pre-dispersion can balance color uniformity and notched impact resistance.

[0058] Comparative Example 1: All raw materials were mixed in one step in the same high-speed mixer. The average color difference was 0.78±0.19, and the notched impact strength was 7.2±0.9 kJ / m. 2 Compared to Example 2, the average color difference and standard deviation between samples in Comparative Example 1 both increased, while the notched impact strength decreased and its standard deviation increased. These results indicate that, under the raw material composition and processing conditions set in this application, simultaneously adding all raw materials to the same high-speed mixer for a single mixing did not achieve the same color consistency and notched impact performance as when the two pre-dispersed materials were formed independently and then melt-blended.

[0059] Although the coloring system and toughening system were added sequentially in Comparative Example 2, the coloring system was not removed from the high-speed mixer after formation, while the toughening system was directly added back into the same mixer for further mixing. The two systems did not form separate pre-dispersed materials under conditions of separation. The average color difference of Comparative Example 2 was 0.56, higher than the 0.22 of Example 2; the notched impact strength was 8.1 kJ / m. 2 It is lower than 10.8 kJ / m³ in Example 2. 2 The results indicate that simply adding the coloring system and toughening system to the same mixing space in a sequential manner is not equivalent to forming the coloring pre-dispersion and toughening pre-dispersion separately in mutually isolated mixing spaces, nor does it achieve the same color consistency and notched impact performance as in Example 2.

[0060] Comparative Example 3 only formed a coloring pre-dispersion material independently, without forming a toughening pre-dispersion material independently. Its average color difference was 0.31, close to 0.22 in Example 2, but its notched impact strength was only 8.0 kJ / m. 2 It is lower than 10.8 kJ / m³ in Example 2. 2 The results indicate that when the colored pre-dispersion is formed independently, the resulting sample can maintain a relatively low color difference between samples, but its notched impact strength is still lower than that of Example 2. It cannot simultaneously obtain the same color consistency and notched impact performance as when the two pre-dispersions are formed independently.

[0061] Comparative Example 4 only formed a toughening pre-dispersion material independently, without forming a coloring pre-dispersion material independently. Its notched impact strength was 9.4 kJ / m. 2 It is higher than that of Comparative Examples 1-3, but still lower than the 10.8 kJ / m² of Example 2. 2 The average color difference was 0.69, significantly higher than the 0.22 in Example 2. This result indicates that when the toughening pre-dispersion material is formed independently, the notched impact strength of the obtained sample is higher than that of Comparative Examples 1 to 3, but the color difference between the samples is still higher than that in Example 2, and it is not possible to simultaneously achieve both color consistency and notched impact performance.

[0062] Comparative Example 5 did not contain an impact modifier and was supplemented with an equal mass of PMMA carrier resin to reach 100% of the total raw material mass. The notched impact strength of Comparative Example 5 was lower than that of Examples 1-6, and also lower than that of Comparative Examples 1-4, which contained an impact modifier but used different mixing methods. This indicates that under the raw material composition and processing conditions set in this application, the addition of an impact modifier corresponds to a higher notched impact strength in the resulting PMMA masterbatch molded sample. Example 2 used the same raw material composition and amount as Comparative Examples 1-4, and its notched impact strength was further higher than that of Comparative Examples 1-4, with the standard deviation of the test results not exceeding that of Comparative Examples 1-4. These results indicate that, based on the addition of an impact modifier, forming a coloring pre-dispersion and a toughening pre-dispersion before melt blending can further improve the notched impact performance of the obtained sample, achieving a toughening effect.

[0063] Based on the test results of Example 2 and Comparative Examples 1-5, it can be seen that the coloring pre-dispersion material and the toughening pre-dispersion material are formed independently before being mixed and melt-blended, rather than being a simple replacement of a conventional one-time mixing or sequential addition method within the same mixing space. Under the same raw material composition, raw material dosage, and subsequent processing conditions, the toughened PMMA masterbatch obtained using the above-mentioned independent pre-dispersion process exhibits lower inter-sample color difference and color difference standard deviation, and higher notched impact strength. This demonstrates that forming the coloring system and toughening system into pre-dispersion materials before melt-blending can simultaneously improve the color consistency and notched impact performance of the resulting masterbatch, thus achieving a toughening effect.

[0064] While the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of this disclosure, and all such changes and modifications will fall within the scope of protection of this invention.

Claims

1. A toughened PMMA masterbatch, characterized in that, It is made of PMMA carrier resin, color powder, impact modifier, dispersant and processing aid; The PMMA carrier resin includes a first PMMA carrier resin and a second PMMA carrier resin. The color powder and the dispersant are dispersed in the first PMMA carrier resin to form a coloring pre-dispersed material. The impact modifier and the processing aid are dispersed in the second PMMA carrier resin to form a toughening pre-dispersed material. The coloring pre-dispersed material and the toughening pre-dispersed material are melt-blended to form the toughening PMMA masterbatch.

2. The toughened PMMA masterbatch according to claim 1, characterized in that, Based on the total mass of the raw materials used to prepare the toughened PMMA masterbatch, the toughened PMMA masterbatch is made from the following components in weight percentage: 60-78% PMMA carrier resin, 8-16% color powder, 12-20% impact modifier, 1-2.5% dispersant, and 1-1.5% processing aid, with the sum of the weight percentages of each component being 100%.

3. The toughened PMMA masterbatch according to claim 1, characterized in that, The mass ratio of the first PMMA carrier resin to the second PMMA carrier resin is 1:(1.5~3).

4. The toughened PMMA masterbatch according to claim 1, characterized in that, The impact modifier is one of acrylic rubber copolymers and acrylate core-shell structure impact modifiers.

5. The toughened PMMA masterbatch according to claim 1, characterized in that, The pigments include one or more of organic and inorganic pigments.

6. The toughened PMMA masterbatch according to claim 5, characterized in that, The organic pigments include one or more of azo pigments, phthalocyanine pigments, and polycyclic aromatic hydrocarbon pigments, and the inorganic pigments include one or more of titanium dioxide, carbon black, ultramarine, and iron oxide pigments.

7. The toughened PMMA masterbatch according to claim 1, characterized in that, The dispersant is polyethylene wax.

8. The toughened PMMA masterbatch according to claim 1, characterized in that, The processing aids include antioxidants and lubricants; the antioxidants include one or more of hindered phenolic antioxidants and phosphite antioxidants, and the lubricants include one or more of pentaerythritol tetrastearate, ethylene bis-stearamide, and magnesium stearate.

9. A method for preparing toughened PMMA masterbatch, characterized in that, The method for preparing the toughened PMMA masterbatch according to any one of claims 1 to 8 comprises the following steps: After weighing each component according to the weight formula, the PMMA carrier resin and impact modifier are dried. The dried PMMA carrier resin is divided into a first PMMA carrier resin and a second PMMA carrier resin. The color powder, the dispersant, and the first PMMA carrier resin are placed in a first mixing space and mixed to disperse the color powder in the first PMMA carrier resin, thereby obtaining a coloring pre-dispersed material. The impact modifier, the processing aid, and the second PMMA carrier resin are placed in a second mixing space that is isolated from the first mixing space and mixed to disperse the impact modifier in the second PMMA carrier resin, thereby obtaining a toughened pre-dispersion. Before the coloring predispersant and the toughening predispersant are formed, no material transfer is performed between the first mixing space and the second mixing space. After they are formed, they are combined and melt-blended, extruded, cooled and pelletized to obtain toughened PMMA color masterbatch.

10. The method for preparing toughened PMMA masterbatch according to claim 9, characterized in that, The melt blending and extrusion are carried out using a twin-screw extruder, and the temperature of each heating zone in the melt blending section of the twin-screw extruder is 185–225°C.

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