Uv-aging resistant color master batch and preparation method thereof

Abstract

The application discloses a kind of color master batch of ultraviolet aging resistance and preparation method thereof, it is related to the technical field of aging resistance color master batch.A kind of color master batch of ultraviolet aging resistance, by mass parts count its raw material component includes: matrix resin 50-80 parts, colorant 5-20 parts, ultraviolet aging resistance agent 2-8 parts, dispersing agent 3-10 parts, processing aid 0.3-2 partsThe application is more excellent in ultraviolet aging resistance and processing stability, the specific structure ultraviolet aging resistance agent used can be well compatible with matrix resin, not easy to migrate and strong thermal stability, can avoid the attenuation problem of protective effect caused by poor compatibility and insufficient thermal stability of traditional anti-aging agent, while the synergistic effect of each component guarantees the flow stability in the process of color master batch processing, reduces the performance fluctuation caused by processing problem.

Description

Technical Field

[0001] This invention relates to the field of aging-resistant masterbatch technology, specifically to a UV-resistant masterbatch and its preparation method. Background Technology

[0002] Color masterbatch, as a core functional material for coloring polymer materials, is widely used in plastic building materials, outdoor daily necessities, automotive exterior parts, and other fields. Its performance directly determines the appearance stability and service life of the final product. In outdoor applications, plastic products are exposed to ultraviolet radiation for a long time, which can easily lead to problems such as molecular chain breakage and colorant degradation, resulting in fading, surface cracking, and decreased mechanical strength. This not only affects the appearance of the product but also significantly shortens its service life. Therefore, the UV aging resistance of color masterbatch has become a key technical indicator.

[0003] Currently, most UV-resistant masterbatches on the market use traditional anti-aging agents such as benzotriazoles and hindered amines. These anti-aging agents have obvious drawbacks: First, they have poor compatibility with the base resin (such as polyethylene and polypropylene), and are prone to migrating to the surface of the product during processing or use, causing the anti-aging effect to decay rapidly over time; second, they have insufficient thermal stability and are prone to decomposition during the melt extrusion of the masterbatch (usually at a temperature of 180-220℃), which not only reduces the anti-aging efficiency but may also produce small molecule impurities that affect the appearance of the product.

[0004] Meanwhile, existing color masterbatches often face the problem of poor synergistic dispersibility between colorants and anti-aging agents. If colorants (such as carbon black and phthalocyanine blue) are not dispersed evenly, they will form "agglomeration points" with excessively high local concentrations. These areas not only have appearance defects, but also become weak links in the effect of ultraviolet light, accelerating the local aging of the product. On the other hand, the imbalance in the dispersion of anti-aging agents will lead to some areas of the product lacking effective protection, resulting in the phenomenon of "local premature aging".

[0005] With the increasing demands for service life and processing stability of outdoor plastic products, traditional masterbatches can no longer meet market requirements. Developing a masterbatch with high UV aging resistance, good compatibility with the matrix, excellent processing thermal stability, and uniform dispersion has become a technical challenge that the industry urgently needs to solve. Summary of the Invention

[0006] The purpose of this invention is to address the problems in the existing technology where the UV-resistant aging agent has poor compatibility with the matrix resin, insufficient thermal stability, and uneven dispersion of the colorant and anti-aging agent, resulting in poor UV resistance and unstable processing of the masterbatch. The invention provides a UV-resistant masterbatch with high UV resistance efficiency, good compatibility with the matrix, excellent processing thermal stability, and uniform dispersion of all components, as well as its preparation method.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is: a color masterbatch resistant to ultraviolet aging, the raw material components of which, by mass, include: 50-80 parts of matrix resin, 5-20 parts of colorant, 2-8 parts of ultraviolet aging resistant agent, 3-10 parts of dispersant, and 0.3-2 parts of processing aid;

[0008] The UV-resistant aging agent is a compound represented by Formula 1;

[0009] The structure of Equation 1 is as follows: ;

[0010] In Formula 1, R1 is a substituent, and R1 is selected from any one of hydrogen, fluorine, hydroxyl, methyl, ethyl, and methoxy.

[0011] Furthermore, the matrix resin is either polyethylene or polypropylene.

[0012] Furthermore, the colorant is an organic pigment or an inorganic pigment;

[0013] The organic pigment is any one of phthalocyanine blue, permanent red, and quinacridone violet;

[0014] The inorganic pigment is any one of carbon black, titanium dioxide, and iron oxide red.

[0015] Furthermore, the UV-resistant aging agent is any one of the compounds shown in the following structures:

[0016] 1;

[0017] 2;

[0018] 3;

[0019] 4;

[0020] 5.

[0021] Furthermore, the dispersant is any one of polyethylene wax, stearic acid, and glyceryl stearate.

[0022] Furthermore, the processing aid is any one of zinc stearate, calcium stearate, and ethylene bis-stearamide.

[0023] A method for preparing a UV-resistant masterbatch includes the following steps:

[0024] Step 1: Weigh the matrix resin, colorant, UV aging resistant agent, dispersant and processing aid according to the mass ratio, put them into a mixing device, and mix at a speed of 800-1500 r / min for 15-45 min to obtain a premix;

[0025] Step 2: Add the premixed material to the extruder, control the temperature of the first zone of the extruder to 160-180℃, the temperature of the second zone to 180-200℃, the temperature of the third zone to 200-220℃, the temperature of the die head to 200-210℃, and the screw speed to 300-500 r / min, and perform melt extrusion to obtain extruded strips;

[0026] Step 3: The extruded strip is granulated by a pelletizer and then placed in a drying device and dried at a temperature of 60-80℃ for 2-4 hours to obtain a color masterbatch resistant to ultraviolet aging.

[0027] Furthermore, step 1 is performed under a nitrogen atmosphere.

[0028] Furthermore, the drying equipment in step 3 is a vacuum drying oven, and the vacuum degree is controlled to be -0.08 to -0.06 MPa during the drying process.

[0029] Furthermore, in step 2, the temperature of the extruder is controlled at 165-175℃ in zone 1, 185-195℃ in zone 2, 205-215℃ in zone 3, and 202-208℃ at the die head.

[0030] The high efficiency and stability of the UV-resistant aging agent molecule described in the invention stems from the synergistic effect between its extended aromatic ring conjugated structure and the imino-NH- unit. This synergistic mechanism constitutes an efficient "absorption-conversion" energy dissipation process: The extended aromatic ring conjugated system acts as a highly efficient energy absorber, strongly absorbing UV light energy in the 290-400nm wavelength band with its highly delocalized π-electron cloud, and rapidly dispersing the energy to avoid local accumulation. This provides a basis for its excellent thermal stability under high-temperature processing at 200-220℃. Simultaneously, the imino unit plays a crucial "stabilizing anchor" role in the energy conversion process; its core mechanism is that when the molecule is excited... A rapid and reversible intramolecular proton transfer tautomerism occurs, converting harmful excited-state photochemical energy into harmless thermal energy and dissipating it, while the molecule itself returns to its ground state for recycling. In addition, the imino group can form a weak interaction with the polyolefin matrix resin, effectively inhibiting the migration and volatilization of aging agent molecules through anchoring, thus directly solving the problems of poor compatibility and easy decay of traditional aging agents. Finally, the synergistic cooperation between the aromatic ring conjugated structure and the imino group achieves broad-spectrum and strong absorption of ultraviolet light, efficient and lossless energy conversion, and long-term stable durability, giving the molecule high UV aging resistance, excellent processing thermal stability, and good compatibility with the matrix.

[0031] This invention comprehensively solves three major technical problems by constructing a synergistic system: poor compatibility between UV-resistant aging agents and matrix resins, insufficient thermal stability of the agents themselves, and uneven dispersion of colorants and anti-aging agents. Its core lies in the UV-resistant aging agent shown in Formula 1, whose extended aromatic ring conjugated system is responsible for efficiently absorbing and dispersing UV light energy, providing an inherent basis for thermal stability, enabling it to withstand processing temperatures of 200-220℃. The imino group within it forms a weak interaction with the molecular chains of polyolefin matrix resins such as polyethylene (PE) or polypropylene (PP), acting as an "anchor" to fix the aging agent molecules in the resin, significantly improving compatibility and anti-migration properties. Simultaneously, this imino group can convert absorbed UV light energy into harmless heat dissipation through intramolecular proton transfer, achieving a "absorption-conversion-anchoring" cyclical protection mechanism. To further ensure effectiveness, the dispersant works synergistically during high-speed mixing and melt extrusion. It coats the surface of colorant and UV-resistant aging agent particles, effectively breaking up agglomerates using screw shear force, achieving a fine and uniform distribution within the resin matrix. This avoids color defects and localized UV protection weaknesses. The processing aid works synergistically with the processing to reduce melt viscosity and internal frictional heat, providing a milder processing environment for the UV-resistant aging agent to further ensure its thermal stability. It also improves material flowability, helping the dispersant to "carry" particles to a wider area and enhancing dispersion uniformity. Finally, the polyolefin matrix resin acts as a synergistic platform. Its non-polar properties provide conditions for weak interactions, and its melting environment lays the foundation for the synergistic effect of each component, thus forming a highly efficient, stable, and durable comprehensive solution.

[0032] Compared with the prior art, the beneficial effects of the present invention are:

[0033] 1. This invention has superior UV aging resistance and processing stability. The specific structure of the UV aging agent it uses is well compatible with the matrix resin, does not easily migrate, and has strong thermal stability. It can avoid the problem of reduced protective effect caused by poor compatibility and insufficient thermal stability of traditional anti-aging agents. At the same time, the synergistic effect of each component ensures the flow stability of the masterbatch during processing and reduces performance fluctuations caused by processing problems.

[0034] 2. This invention excels in component dispersion uniformity and appearance durability. With the synergistic effect of dispersants and processing aids, it can effectively solve the problem of uneven dispersion of colorants and anti-aging agents, and avoid the appearance problems such as local aging and color spots caused by dispersion defects in traditional masterbatches. This allows the masterbatches to maintain good appearance and color stability even after long-term UV aging. Attached Figure Description

[0035] Figure 1 This is the NMR spectrum of UV-resistant aging agent 1 of the present invention.

[0036] Figure 2 This is a schematic diagram of the synthesis process of Preparation Example 1 of the present invention. Detailed Implementation

[0037] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0038] Preparation Example 1

[0039] Preparation of UV-resistant aging agent 1:

[0040] A schematic diagram of the chemical reaction synthesis process is shown below. Figure 2 ;

[0041] CAS number for raw material 1: 175728-78-6;

[0042] CAS number for raw material 2: 586-76-5;

[0043] Under nitrogen protection, 10 g of raw material 1 and 8.37 g of raw material 2 were dissolved in 120 mL of a mixed solvent of 1,4-dioxane / diisopropylamine (80 mL / 40 mL). Then, 0.38 g of palladium acetate, 0.82 g of 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl, and 0.33 g of CuI were added to the system. The reaction was carried out at 90 °C for 5 h. After the reaction was completed, the temperature was slightly lowered, and the mixture was filtered through diatomaceous earth to remove salts and catalyst. The reaction solution was concentrated and separated by silica gel column chromatography using a mixed solvent of n-heptane and ethyl acetate as the eluent. The solution was evaporated to dryness to obtain 11.31 g of intermediate 1. The mass spectra of intermediate 1 were m / z, MS+1: 409.

[0044] CAS number for raw material 3: 164926-91-4;

[0045] Under nitrogen protection, 11.31 g of intermediate 1, 5.76 g of raw material 3, 3.74 g of 1-hydroxybenzotriazole, and 140 ml of dichloromethane were stirred until homogeneous. Then, 2.72 g of concentrated sulfuric acid was slowly added dropwise. The mixture was heated to 40 °C and reacted for 6 h. After the reaction, the pH of the system was adjusted to neutral with 0.1 mol / L sodium bicarbonate. The organic phase was retained, concentrated, and separated by silica gel column chromatography using a mixed solvent of n-heptane and ethyl acetate as the eluent. The solution was evaporated to dryness to obtain 12.21 g of UV-resistant aging agent 1. The mass spectrometry (m / z, MS+1: 564) and NMR spectrometry of UV-resistant aging agent 1 are shown below. Figure 1 .

[0046] Preparation Examples 2-5

[0047] In Preparation Examples 2-5, UV-resistant aging agent 2-UV-resistant aging agent 5 were prepared sequentially, following the preparation method of Preparation Example 1, except that raw material 2 was replaced, and the rest remained the same as in Preparation Example 1. For details, please refer to Table 1.

[0048] Table 1

[0049] Raw material 2 structure UV aging agent structure Preparation Example 2 CAS No. 112704-79-7 UV Age Resistant 2, Mass Spec m / z, MS+1 : 582 Preparation Example 3 CAS No. 1666-28-0 UV Age Resister 3, Mass Spec m / z, MS+1: 580 Preparation Example 4 CAS No. 72135-36-5 UV Age Resister 4, Mass Spec m / z, MS+1: 594 Preparation Example 5 CAS No. 741698-92-0 UV aging resistant agent 5, mass spectrometry m / z, MS+1: 592

[0050] Example 1

[0051] Preparation of a UV-resistant masterbatch:

[0052] 1. Raw material composition by weight:

[0053] 65 parts of matrix resin (polypropylene, melt flow rate (MFR): 3±0.9 g / 10min) were purchased from Ningbo Fude Energy Co., Ltd., product model: polypropylene resin T30S.

[0054] 12 parts of colorant (phthalocyanine blue), purchased from: Anhui Sanxin Chemical Co., Ltd.;

[0055] Five parts of UV aging resistant agent (using UV aging resistant agent 1 prepared in Preparation Example 1);

[0056] Dispersant (polyethylene wax, melting point: 115℃) 6 parts, purchased from Jiangsu Tianwen New Material Technology Co., Ltd., product model: TW-F0042;

[0057] Processing aid (zinc stearate) 1.2 parts, purchased from: Shandong Chongcheng Energy Technology Co., Ltd.

[0058] 2. Preparation method:

[0059] Step 1: Accurately weigh the base resin, colorant, UV aging resistant agent, dispersant, and processing aids according to the above-mentioned weight proportions, and put all raw materials into a high-speed mixer. Pour high-purity nitrogen (purity ≥99.99%) into the mixer to replace the internal air and maintain a nitrogen atmosphere. Set the mixer speed to 1200 r / min, the mixing time to 30 min, and the mixing temperature to 45℃. During this period, control the temperature of the mixing system to not exceed 50℃ using jacketed water cooling. After mixing, a uniform premix is ​​obtained.

[0060] Step 2: The premix obtained in Step 1 is continuously fed into a twin-screw extruder (L / D ratio 36:1) via a screw feeder. The extruder temperature and screw speed parameters for each section are set as follows: Zone 1 temperature 170℃, Zone 2 temperature 190℃, Zone 3 temperature 210℃, Die head temperature 205℃, and screw speed 400 r / min. After being melted, sheared, and mixed in the extruder, the premix is ​​extruded through the die head (3mm orifice) to form a continuous and uniform extruded strip. During the extrusion process, volatiles in the system are removed through a vacuum exhaust port (vacuum degree -0.09MPa).

[0061] Step 3: The extruded strip obtained in Step 2 is introduced into a cooling water tank (water temperature 25℃, water flow rate 0.8m / s) for cooling and shaping. After the surface of the strip is completely solidified, it is sent to a pelletizer for pelletizing. The pellet length is controlled to be 2.5mm±0.2mm. The pellets are then transferred to a vacuum drying oven, and the drying temperature is set to 70℃, the vacuum degree to -0.07MPa, and the drying time to 3 hours. During the drying process, nitrogen is purged every hour to remove moisture from the oven. After drying, the pellets are allowed to cool naturally to room temperature, thus obtaining the UV-resistant masterbatch described in this embodiment.

[0062] Examples 2-5

[0063] The preparation of a UV-resistant masterbatch is carried out by referring to the preparation method of Example 1, except that the UV-resistant aging agent is replaced sequentially with UV-resistant aging agent 2-UV-resistant aging agent 5, and the rest is the same as in Example 1.

[0064] Comparative Example 1

[0065] The preparation of a UV-resistant masterbatch is carried out by referring to the preparation method of Example 1, except that the UV-resistant aging agent is replaced with 2-hydroxy-4-methoxybenzophenone (UV-9, a commonly used UV-resistant aging agent), and the rest is the same as in Example 1.

[0066] Comparative Example 2

[0067] The preparation of a UV-resistant masterbatch follows the preparation method of Example 1, except that the UV-resistant aging agent is replaced with UV absorber-928. (Commonly used UV-resistant aging agents), the rest is the same as in Example 1.

[0068] Comparative Example 3

[0069] The preparation of a UV-resistant masterbatch is carried out by referring to the preparation method of Example 1, except that the UV-resistant aging agent is replaced with 2-(4,6-diphenyl-1,3,5-triazine-2-yl)-5-(hexyloxy)phenol (UV-1577, a commonly used UV-resistant aging agent), and the rest is the same as in Example 1.

[0070] Comparative Example 4

[0071] The preparation of a UV-resistant masterbatch is carried out according to the preparation method of Example 1, except that the UV-resistant aging agent is not added, and the rest is the same as in Example 1.

[0072] Comparative Example 5

[0073] The preparation of a UV-resistant masterbatch is carried out according to the preparation method of Example 1, without the addition of processing aids, and otherwise remains the same as in Example 1.

[0074] Performance testing:

[0075] 1. Melt Flow Rate (MFR) Test: Referring to the test method in GB / T 3682.1-2018 "Determination of Melt Mass Flow Rate (MFR) and Melt Volume Flow Rate (MVR) of Thermoplastic Plastics - Part 1: Standard Method", the melt flow rate (MFR, unit g / 10min) of a UV-resistant masterbatch prepared in the examples and comparative examples was tested, and the data are shown in Table 2.

[0076] 2. UV Aging Test: The UV-resistant masterbatch prepared in the examples and comparative examples was placed in a UV aging test chamber using a UV-A-340 light source with an irradiance of 0.71 W / (m²). 2 •nm), the aging cycle was set as "8h irradiation (60℃, no condensation) + 4h condensation (20℃, 90% relative humidity)", with a total aging time of 3600h. The CIE LAB color coordinates (L) of the samples were measured using a spectrophotometer. * a * b * ), calculate the color difference ΔE between the aged sample and the initial sample. ab The formula is: , where ΔL * =L 老化 -L 初始 , Δa * =a 老化 -a 初始 , Δb * =b 老化 -b 初始 The appearance of the aged samples was observed, and the data are shown in Table 2.

[0077] Table 2.

[0078] MFR g / 10min <![CDATA[ΔE ab ]]> Appearance of the aged sample Example 1 2.8 0.8 The surface is smooth and free from cracks and powdering; the color is uniform; there are no obvious fading or discolored spots; and there are no traces of migration or precipitation. Example 2 2.7 0.8 The surface is smooth and free from cracks and powdering; the color is uniform; there are no obvious fading or discolored spots; and there are no traces of migration or precipitation. Example 3 2.9 1.0 The surface is smooth and free from cracks and powdering; the color is uniform; there are no obvious fading or discolored spots; and there are no traces of migration or precipitation. Example 4 2.6 1.1 The surface is smooth and free from cracks and powdering; the color is uniform; there are no obvious fading or discolored spots; and there are no traces of migration or precipitation. Example 5 2.8 0.9 The surface is smooth and free from cracks and powdering; the color is uniform; there are no obvious fading or discolored spots; and there are no traces of migration or precipitation. Comparative Example 1 2.9 4.8 A slight powdery layer appears on the surface; rubbing it with a finger reveals a small amount of powder falling off. The color has faded noticeably, and some light white spots are present. Comparative Example 2 3.0 4.5 The surface smoothness decreased, fine cracks appeared at the edges, and there was slight yellowing. There was no obvious chalking, but the gloss was reduced. Comparative Example 3 2.9 4.2 There are no obvious cracks, but the surface gloss is significantly reduced, the color uniformity is worse, and "color spots" appear in some areas. There is no powdering, but the texture becomes slightly rough after aging. Comparative Example 4 3.1 8.5 The surface was severely powdery, with a large amount of powder falling off after wiping. The sample showed obvious cracking, a significant decrease in color depth, and localized grayish-white discoloration. Some particles were deformed and adhered together. Comparative Example 5 3.8 2.9 The surface is free of cracks, but there are localized "agglomeration points" with varying color depths. The agglomeration point areas do not show powdering, but their color is noticeably lighter. The overall melt flowability fluctuates significantly, and some particles have minor indentations on their surfaces.

[0079] Examples of the UV-resistant aging agent using the structure of Formula 1 of the present invention (Examples 1-5) show that the melt flow rate remains stable overall, with a high degree of matching with the initial flow characteristics of the matrix resin. There are no significant fluctuations due to the addition of the UV-resistant aging agent. After 3600 hours of UV aging, the color difference remains at a low level, the appearance of the sample remains flat, and there are no aging defects such as cracking, powdering, or uneven color. There are also no traces of aging agent migration and precipitation, demonstrating excellent processing stability and UV aging resistance. While the comparative examples using traditional UV-resistant aging agents showed melt flow rates similar to the examples, the color difference increased significantly after aging, and problems such as powdering, cracking, decreased gloss, or localized color variations appeared successively. The UV protection effect decreased significantly over time. Comparative Example 4, without the addition of a UV-resistant aging agent, not only showed extremely high color differences after aging but also severe powdering, cracking, and particle deformation and adhesion, completely losing its practical performance. Comparative Example 5, without the addition of processing aids, showed increased fluctuations in melt flow rate, and due to uneven component dispersion, color depth differences corresponding to local agglomeration points appeared after aging. The processing stability and appearance uniformity were significantly inferior to the examples. Overall, this invention, through the synergistic effect of a specific UV-resistant aging agent and various components, significantly outperforms the comparative schemes using traditional aging agents or lacking key components in terms of processing stability, UV aging resistance, and appearance retention.

[0080] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A color masterbatch resistant to ultraviolet aging, characterized in that, The raw material components, by weight, include: 50-80 parts of matrix resin, 5-20 parts of colorant, 2-8 parts of UV aging resistant agent, 3-10 parts of dispersant, and 0.3-2 parts of processing aid; The UV-resistant aging agent is a compound represented by Formula 1; Formula 1; In Formula 1, R1 is a substituent, and R1 is selected from any one of hydrogen, fluorine, hydroxyl, methyl, ethyl, and methoxy.

2. The UV-resistant masterbatch according to claim 1, characterized in that, The matrix resin is either polyethylene or polypropylene.

3. The UV-resistant masterbatch according to claim 1, characterized in that, The colorant is an organic pigment or an inorganic pigment; The organic pigment is any one of phthalocyanine blue, permanent red, and quinacridone violet; The inorganic pigment is any one of carbon black, titanium dioxide, and iron oxide red.

4. The UV-resistant masterbatch according to claim 1, characterized in that, The UV-resistant aging agent is any one of the compounds shown in the following structures: 1； 2； 3； 4； 5。 5. A UV-resistant masterbatch according to claim 1, characterized in that, The dispersant is any one of polyethylene wax, stearic acid, and glyceryl stearate.

6. A UV-resistant masterbatch according to claim 1, characterized in that, The processing aid is any one of zinc stearate, calcium stearate, and ethylene bis-stearamide.

7. A method for preparing a UV-resistant masterbatch as described in any one of claims 1-5, characterized in that, Includes the following steps: Step 1: Weigh the matrix resin, colorant, UV aging resistant agent, dispersant and processing aid according to the mass ratio, put them into a mixing device, and mix at a speed of 800-1500 r / min for 15-45 min to obtain a premix; Step 2: Add the premixed material to the extruder, control the temperature of the first zone of the extruder to 160-180℃, the temperature of the second zone to 180-200℃, the temperature of the third zone to 200-220℃, the temperature of the die head to 200-210℃, and the screw speed to 300-500 r / min, and perform melt extrusion to obtain extruded strips; Step 3: The extruded strip is granulated by a pelletizer and then placed in a drying device and dried at a temperature of 60-80℃ for 2-4 hours to obtain a color masterbatch resistant to ultraviolet aging.

8. The method for preparing a UV-resistant masterbatch according to claim 7, characterized in that, Step 1 is performed under a nitrogen atmosphere.

9. A method for preparing a UV-resistant masterbatch according to claim 7, characterized in that, The drying equipment in step 3 is a vacuum drying oven, and the vacuum degree is controlled to be -0.08 to -0.06 MPa during the drying process.

10. A method for preparing a UV-resistant masterbatch according to claim 7, characterized in that, In step 2, the temperature of the extruder is controlled at 165-175℃ in zone 1, 185-195℃ in zone 2, 205-215℃ in zone 3, and 202-208℃ at the die head.

Images