A weather-resistant color master batch for modified polypropylene cable protection pipe and a preparation method thereof

Abstract

The application relates to a weather-resistant color master batch for modified polypropylene cable protection pipes, which is composed of a carrier resin, a photo-thermal stable color powder, a filler and a grafting compatibility modifier; the photo-thermal stable color powder is composed of zinc dicyclopentadiene dimethylate, orange yellow, bright red, an antioxidant, an ultraviolet absorber and a dispersant; the dicyclopentadiene in the zinc dicyclopentadiene dimethylate has heat-reversible crosslinking properties, is disdimerized during heat processing, has good processing fluidity, is re-cyclized and addition-dimerized to be crosslinked after temperature reduction, so that the decomposition of the orange yellow and the bright red caused by cable heating is reduced; meanwhile, the antioxidant and the ultraviolet absorber have a compound synergistic effect, so that the weather resistance of the color master batch can be better improved; the modified polypropylene cable protection pipe prepared by using the color master batch has the advantages of color stability, reduced processing toxicity, good processing fluidity, low price and the like, and is more suitable for power cable protection pipe use.

Description

Technical Field

[0001] This invention relates to a weather-resistant masterbatch and its preparation method, particularly a weather-resistant masterbatch for modified polypropylene cable protection pipes and its preparation method. Background Technology

[0002] As a key raw material for coloring power pipelines, the performance of masterbatch directly determines the color performance, processing performance, and service performance of the final product. Power pipelines are exposed to the outdoors for extended periods, enduring harsh environments such as wind, sun, and rain, thus requiring extremely high weather resistance. As a crucial component of power pipelines, the weather resistance of masterbatch directly impacts the pipeline's service life and safety. With changing market demands, customers are continuously raising their performance requirements for masterbatch, especially in terms of color stability and weather resistance. Traditional general-purpose masterbatches are gradually becoming insufficient to meet product needs. Simultaneously, in response to the strategic goal of cost reduction and efficiency improvement, this invention has developed a modified polypropylene cable protection pipe weather-resistant masterbatch. The aim is to create a higher-performance, more cost-effective masterbatch product through technological innovation and process optimization, better meeting market demands and enhancing enterprise competitiveness. Summary of the Invention

[0003] Based on the shortcomings of traditional general-purpose masterbatches in terms of color stability and weather resistance, the purpose of this invention is to provide a weather-resistant masterbatch for modified polypropylene cable protection pipes. Compared with existing modified polypropylene cable protection pipes, the prepared modified polypropylene cable protection pipe has stable color, reduced processing toxicity, good processing fluidity, and is cheaper. The impact strength and tensile strength retention rate is 100%, making it more suitable for use in power cable protection pipes.

[0004] The technical solution adopted by the present invention to achieve the above objectives is as follows: (1) A weather-resistant masterbatch for modified polypropylene cable protection pipe and its preparation method, characterized in that: the weather-resistant modified polypropylene cable sheathing pipe masterbatch is composed of carrier resin, photothermal stabilized color powder, filler and graft compatibility modifier. The composition includes 100 parts by weight of carrier resin, 60-80 parts by weight of photothermal stabilized color powder, 180-200 parts by weight of filler, and 8-20 parts by weight of graft compatibility modifier. The photothermal stabilized color powder is composed of zinc dicyclopentadiene dicarboxylate, orange, scarlet, antioxidant, ultraviolet absorber and dispersant; The orange-yellow color is an azo pigment with the molecular formula C32H24Cl2N8O2; The crimson pigment is an azo pigment, with the molecular formula... C18H11BaClN2O6S ; The antioxidant is composed of high molecular weight hindered phenolic antioxidant AT1010 and phosphite antioxidant AT168, in a weight ratio of 1:1. The ultraviolet absorber is UV-531, 2-hydroxy-4-n-octyloxybenzophenone, with the molecular formula C21H26O3; The dispersant is composed of stearic acid and polyethylene wax in a weight ratio of 1:2; The composition includes 100 parts by weight of orange, 100 parts by weight of scarlet, 80-100 parts by weight of zinc dicyclopentadienedicarboxylate, 1-10 parts by weight of antioxidant, 1-10 parts by weight of ultraviolet absorber, and 5-10 parts by weight of dispersant. (2) The method for preparing the photothermal stabilized color powder includes the following steps: Step 1: At 170℃, an equivalent amount of dicyclopentadiene is heated to decompose into cyclopentadiene. An equivalent amount of sodium sand is added to the cyclopentadiene ether solution, and then an equivalent amount of carbon dioxide is introduced. After cooling to room temperature, sodium dicyclopentadiene dicarboxylate is obtained. It is then washed, filtered, and dried for later use. Step 2: Dissolve an equivalent amount of zinc chloride in an aqueous solution to obtain a zinc chloride aqueous solution. Add the solution of sodium dicyclopentadiene dicarboxylate obtained in Step 1 to the solution in water. Stir at 0~100℃ for 5~10h to obtain a precipitate of zinc dicyclopentadiene dicarboxylate. Step 3: Wash, filter, and dry the precipitate obtained in Step 2 for later use; Step 4: Add orange and red to the zinc dicyclopentadiene dicarboxylate obtained in Step 3, and mix thoroughly for 10-20 minutes at 180-200°C using a high-speed mixer. Step 5: Add the antioxidant, ultraviolet absorber and dispersant to the mixture obtained in step 4, and mix thoroughly at 80~100℃ for 10~30 minutes using a high-speed mixer; (3) The carrier resin is LLDPE resin with a melt index between 2 and 10 g / 10 min, especially between 5 and 6 g / 10 min; (4) The filler is composed of organic calcium carbonate and organic talc in a weight ratio of 2:1, and both organic calcium carbonate and organic talc are 800 mesh. (5) The graft compatibility modifier is PE-g-MAH; (6) A method for preparing a color masterbatch for weather-resistant modified polypropylene cable sheathing is as follows: Step 1: Weigh the carrier resin, photothermal stabilized color powder, filler, and graft compatibility modifier according to the weight ratio of the aforementioned weather-resistant modified polypropylene cable sheath color masterbatch, and then mix them thoroughly in a high-speed mixer at 100~120℃ for 1~2 hours. Step 2: The mixture obtained in Step 1 is taken out and melt-extruded through a twin-screw extruder. It is then cooled and shaped by cooling water, and continuously and stably pulled out by a traction machine for granulation, thus obtaining a weather-resistant modified polypropylene cable sheathing masterbatch. The extruder temperature is as follows: first stage: 120~140℃; second stage: 150~180℃; third stage: 190~210℃. The fourth stage temperature is 210℃, the die temperature is 210℃, the die head vacuum is controlled at 0.02~0.05MPa, the cooling water temperature is controlled at 30~45℃, and the traction pressure is controlled at 0.02~0.05MPa. (7) A weather-resistant masterbatch for modified polypropylene cable protection pipes is applied to the preparation of modified polypropylene cable protection pipes. The method is as follows: 100 parts by weight of polypropylene and 1 part by weight of the weather-resistant masterbatch for modified polypropylene cable protection pipes are weighed according to the weight ratio and then fully mixed in a high-speed mixer at 100~120℃ for 1~2 hours; the resulting mixture is taken out and melt-extruded through a twin-screw extruder, then cooled and shaped by cooling water, and continuously and stably pulled by a traction machine. The temperatures in barrel zone 1 are 160~180℃, in barrel zone 2 170~190℃, in barrel zone 3 180~200℃, in barrel zone 4 170~190℃, and in barrel zone 5 150~170℃. The extrusion molding speed is 0.5m / min, the die head vacuum is controlled at 0.03~0.05MPa, the cooling water temperature is controlled at 25~45℃, and the traction pressure is controlled at 0.03~0.05MPa.

[0005] Compared with the prior art, the present invention has the following beneficial effects: (1) The dicyclopentadiene in zinc dicyclopentadiene dicarboxylate has thermally reversible crosslinking properties. It de-dimerizes during hot processing, resulting in good processing fluidity. After cooling, it re-cyclizes and adds dimerizes to crosslink. During processing, the amount of pigment added exceeds the limit, which will reduce the processing fluidity. At the same time, the processing temperature of the carrier resin is 120-210℃, which requires the pigment to have heat resistance. Exceeding 200℃ will cause the pigment to degrade. Zinc dicyclopentadiene dicarboxylate reacts with the -Cl in the C-Cl of the orange and scarlet chains to form a stable structure, preventing the orange and scarlet from degrading. The red dye undergoes a deHCl reaction, thus reducing the thermal decomposition of orange and bright red dyes during processing. Furthermore, the zinc carboxylate of zinc dicyclopentadienedicarboxylate absorbs the released HCl, eliminating the autocatalytic degradation effect of HCl. Since the processing temperature exceeds 170℃, zinc dicyclopentadienedicarboxylate is unlikely to form dimers, ensuring processing fluidity. Simultaneously, in practical use, zinc dicyclopentadienedicarboxylate polymerizes into zinc dicyclopentadienedicarboxylate, and the cross-linking bridges formed between the bicyclic rings in the molecular chains reduce the decomposition of orange and bright red dyes caused by cable heating. (2) Both antioxidants and ultraviolet absorbers have a synergistic effect with zinc dicyclopentadiene dicarboxylate, which can better improve the weather resistance of the masterbatch; (3) The main function of dispersants is to improve the dispersibility of pigments in carrier resins and ensure uniform distribution of pigments. Their core function is to prevent pigment agglomeration, thereby avoiding uneven color distribution in the final product. Low molecular weight waxes can not only effectively increase the yield of masterbatch and reduce production costs, but also significantly improve the coloring power of masterbatch, with an increase of about 15%. Stearic acid and polyethylene waxes, which have both lubricating functions, can not only effectively improve the dispersibility of pigments, but also play a lubricating role in the processing. With the increase of the proportion of dispersant, the dispersibility of pigments is improved, the processing fluidity is good, and the coloring effect is improved, but the mechanical properties of masterbatch may be affected. (4) When organic calcium carbonate and organic talc are used as fillers, the overall performance of the color masterbatch shows a trend of first increasing and then decreasing as the proportion of fillers increases. A small amount of filler can significantly improve mechanical properties and reduce costs. (5) In order to improve the compatibility between pigments, fillers and carrier resin, a graft compatibility modifier, maleic anhydride grafted polyethylene (PE-g-MAH), is added, which helps pigments and fillers to be uniformly dispersed in the carrier resin. Detailed Implementation

[0006] The present invention will be described in detail below with reference to specific embodiments: The main raw materials used in the examples and comparative examples are shown in Table 1: Table 1. Specifications and Sources of Main Raw Materials Raw material name Specification source LLDPE 2650 Sinopec Organic calcium carbonate 800 mesh Commercially available Organic talc 800 mesh Commercially available Orange 3055 Suzhou Liyan Chemical Co., Ltd. Big Red 8077 Suzhou Liyan Chemical Co., Ltd. Sodium cyclopentadiene zinc chloride Industrial grade Industrial grade Industrial grade Retail sales retail sales retail sales PE wax Industrial grade Commercially available stearic acid 1801 Commercially available antioxidants AT-168 Beijing Jiyi Chemical Co., Ltd. antioxidants AT-1010 Beijing Jiyi Chemical Co., Ltd. Modifier C4089 Shaoxing Sanchuang New Materials Company Modifier C2021 Shaoxing Sanchuang New Materials Company UV absorber UV-531 Suzhou Liyan Chemical Co., Ltd. The main production equipment and experimental instruments used in the examples and comparative examples are shown in Table 2: Table 2 Equipment and Experimental Instruments Equipment Name Manufacturer SHR High-Speed ​​Hybrid Electrical Control Cabinet Zhangjiagang Xinyuan Machinery Manufacturing Co., Ltd. THJ-Twin-Screw Compound Extruder Nanjing Chengmeng Machinery Co., Ltd. cooling water tank self made Cutting machine self made Nanheng Automatic Filling and Packaging Machine Dongguan Nanheng Weighing Equipment Co., Ltd. Injection molding machine Haitian Plastics Machinery Group Co., Ltd. Melt flow rate meter Chengde Precision Testing Machine Co., Ltd. Electronic simply supported beam impact testing machine Chengde Jinjian Testing Instruments Co., Ltd. Electronic universal testing machine Chengde Jinjian Testing Instruments Co., Ltd. Example 1: (1) A color masterbatch for weather-resistant modified polypropylene cable sheathing is composed of carrier resin, photothermal stabilized color powder, filler, and graft compatibility modifier; The composition includes 100 parts by weight of carrier resin, 80 parts by weight of photothermal stabilized color powder, 200 parts by weight of filler, and 20 parts by weight of graft compatibility modifier. The photothermal stabilized color powder is composed of zinc dicyclopentadiene dicarboxylate, orange, scarlet, antioxidant, and ultraviolet absorber. The orange-yellow color is an azo pigment with the molecular formula C32H24Cl2N8O2; The crimson pigment is an azo pigment, with the molecular formula... C18H11BaClN2O6S ; The antioxidant is composed of high molecular weight hindered phenolic antioxidant AT1010 and phosphite antioxidant AT168, in a weight ratio of 1:1. The ultraviolet absorber is UV-531, 2-hydroxy-4-n-octyloxybenzophenone, with the molecular formula C21H26O3; The dispersant is composed of stearic acid and polyethylene wax in a weight ratio of 1:2; The composition includes 100 parts by weight of orange, 100 parts by weight of scarlet, 80 parts by weight of zinc dicyclopentadienedicarboxylate, 8 parts by weight of antioxidant, 8 parts by weight of ultraviolet absorber, and 5 parts by weight of dispersant. (2) The method for preparing the photothermal stabilized color powder includes the following steps: Step 1: At 170℃, an equivalent amount of dicyclopentadiene is heated to decompose into cyclopentadiene. An equivalent amount of sodium sand is added to the cyclopentadiene ether solution, and then an equivalent amount of carbon dioxide is introduced. After cooling to room temperature, sodium dicyclopentadiene dicarboxylate is obtained. It is then washed, filtered, and dried for later use. Step 2: Dissolve an equivalent amount of zinc chloride in an aqueous solution to obtain a zinc chloride aqueous solution. Add the solution of sodium dicyclopentadienedicarboxylate obtained in Step 1 to the solution in water. Stir at 70°C for 10 hours to obtain a precipitate of zinc dicyclopentadienedicarboxylate. Step 3: Wash, filter, and dry the precipitate obtained in Step 2 for later use; Step 4: Add orange and red to the zinc dicyclopentadiene dicarboxylate obtained in Step 3, and mix thoroughly for 20 minutes at 180°C using a high-speed mixer. Step 5: Add the antioxidant, UV absorber and dispersant to the mixture obtained in Step 4, and mix thoroughly at 100°C for 30 minutes using a high-speed mixer; (3) The carrier resin is LLDPE resin with a melt index of about 6 g / 10 min; (4) The filler is composed of organic calcium carbonate and organic talc in a weight ratio of 2:1, and both organic calcium carbonate and organic talc are 800 mesh. (5) The graft compatibility modifier is PE-g-MAH; (6) A method for preparing a color masterbatch for weather-resistant modified polypropylene cable sheathing is as follows: Step 1: Weigh the carrier resin, photothermal stabilized color powder, filler, and graft compatibility modifier according to the weight ratio of the aforementioned weather-resistant modified polypropylene cable sheath color masterbatch, and then mix them thoroughly at 100°C for 2 hours using a high-speed mixer. Step 2: The mixture obtained in Step 1 is taken out and melt-extruded through a twin-screw extruder. It is then cooled and shaped by cooling water, and continuously and stably pulled out by a traction machine for granulation, thus obtaining a weather-resistant modified polypropylene cable sheathing masterbatch. The extruder temperature is as follows: first stage: 140℃, second stage: 160℃, third stage: 180℃. The fourth stage temperature is 210℃, the die temperature is 210℃, the die head vacuum is controlled at 0.05MPa, the cooling water temperature is controlled at 30℃, and the traction pressure is controlled at 0.05MPa. (7) A weather-resistant masterbatch for modified polypropylene cable protection pipe is applied to the preparation of modified polypropylene cable protection pipe. The method is as follows: 100 parts by weight of polypropylene and 1 part by weight of weather-resistant masterbatch for modified polypropylene cable protection pipe are weighed according to the weight ratio and then fully mixed at 100°C for 1 hour in a high-speed mixer; the mixture is taken out and melt-extruded through a twin-screw extruder, then cooled and shaped by cooling water, and continuously and stably pulled out by a traction machine. The temperature of barrel zone 1 is 170°C, the temperature of barrel zone 2 is 180°C, the temperature of barrel zone 3 is 190°C, the temperature of barrel zone 4 is 180°C, the temperature of barrel zone 5 is 160°C, the extrusion molding speed is 0.5m / min, the die vacuum degree is controlled at 0.04MPa, the cooling water temperature is controlled at 30°C, and the traction pressure is controlled at 0.04MPa.

[0007] Comparative Example 1: The photothermal stabilized color powder was replaced with orange, scarlet, antioxidant, ultraviolet absorber and dispersant; (1) A weather-resistant modified polypropylene cable sheath color masterbatch is composed of carrier resin, photothermal stabilized color powder, filler and graft compatibility modifier components; The composition includes 100 parts by weight of carrier resin, 80 parts by weight of photothermal stabilized color powder, 200 parts by weight of filler, and 8 parts by weight of graft compatibility modifier. The photothermal stabilized color powder is composed of orange, bright red, antioxidant, ultraviolet absorber and dispersant; The orange-yellow color is an azo pigment with the molecular formula C32H24Cl2N8O2; The crimson pigment is an azo pigment, with the molecular formula... C18H11BaClN2O6S ; The antioxidant is composed of high molecular weight hindered phenolic antioxidant AT1010 and phosphite antioxidant AT168, in a weight ratio of 1:1. The ultraviolet absorber is UV-531, 2-hydroxy-4-n-octyloxybenzophenone, with the molecular formula C21H26O3; The dispersant is composed of stearic acid and polyethylene wax in a weight ratio of 1:2; The composition includes 100 parts by weight of orange, 100 parts by weight of bright red, 8 parts by weight of antioxidant, 8 parts by weight of ultraviolet absorber, and 5 parts by weight of dispersant. (2) The method for preparing the photothermal stabilized color powder includes the following steps: Step 1: Mix the orange and red ingredients thoroughly in a high-speed mixer for 20 minutes; Step 2: Add the antioxidant, UV absorber and dispersant to the mixture obtained in Step 1, and mix thoroughly at 100°C for 30 minutes using a high-speed mixer; (3)-(7) Same as Example 1: (3)-(7).

[0008] Comparative Example 2: Zinc dicyclopentadiene dicarboxylate, orange, and scarlet were used instead of the photothermal stabilized color powder; (1) A weather-resistant modified polypropylene cable sheath color masterbatch is composed of carrier resin, photothermal stabilized color powder, filler and graft compatibility modifier components; The composition includes 100 parts by weight of carrier resin, 80 parts by weight of photothermal stabilized color powder, 200 parts by weight of filler, and 8 parts by weight of graft compatibility modifier. The photothermal stabilized color powder is composed of zinc dicyclopentadiene dicarboxylate, orange, and scarlet. The orange-yellow color is an azo pigment with the molecular formula C32H24Cl2N8O2; The crimson pigment is an azo pigment, with the molecular formula... C18H11BaClN2O6S ; The composition consists of 100 parts by weight of orange, 100 parts by weight of bright red, and 80 parts by weight of zinc dicyclopentadienedicarboxylate. (2) The method for preparing the photothermal stabilized color powder includes the following steps: Step 1: At 170℃, an equivalent amount of dicyclopentadiene is heated to decompose into cyclopentadiene. An equivalent amount of sodium sand is added to the cyclopentadiene ether solution, and then an equivalent amount of carbon dioxide is introduced. After cooling to room temperature, sodium dicyclopentadiene dicarboxylate is obtained. It is then washed, filtered, and dried for later use. Step 2: Dissolve an equivalent amount of zinc chloride in an aqueous solution to obtain a zinc chloride aqueous solution. Add the solution of sodium dicyclopentadienedicarboxylate obtained in Step 1 to the solution in water. Stir at 70°C for 10 hours to obtain a precipitate of zinc dicyclopentadienedicarboxylate. Step 3: Wash, filter, and dry the precipitate obtained in Step 2 for later use; Step 4: Add orange and red to the zinc dicyclopentadiene dicarboxylate obtained in Step 3, and mix thoroughly at 180°C for 20 minutes using a high-speed mixer. (3)-(7) Same as Example 1: (3)-(7).

[0009] Comparative Example 3: Color powder was used instead of the photothermal stabilized color powder; (1) A color masterbatch for weather-resistant modified polypropylene cable sheathing is composed of carrier resin, color powder, filler and graft compatibility modifier components; The composition includes 100 parts by weight of carrier resin, 80 parts by weight of color powder, 200 parts by weight of filler, and 8 parts by weight of graft compatibility modifier. The color powder is composed of orange-yellow and bright red; The orange-yellow color is an azo pigment with the molecular formula C32H24Cl2N8O2; The crimson pigment is an azo pigment, with the molecular formula... C18H11BaClN2O6S ; The orange and bright red are composed of a 1:1 weight ratio. (2) The method for preparing the pigment is as follows: The orange and red ingredients are thoroughly mixed in a high-speed mixer at 180°C for 20 minutes. (3)-(7) Same as Example 1: (3)-(7).

[0010] The modified polypropylene cable protection pipe samples prepared in Example 1 and Comparative Examples 1-3 were subjected to the following tests:

[0011] Experiment Example 1: Material Aging Test The modified polypropylene samples obtained in Example 1 and Comparative Examples 1-3 were subjected to deuterium lamp aging for 250 minutes according to GB / T 16422.2-2022.

[0012] Table 1. Colors of samples obtained in Example 1 and Comparative Examples 1-3 at different aging times. Serial Number 50min 100min 150min 200min 250min Example 1 No color change No color change No color change No color change No color change Comparative Example 1 No color change No color change No color change No color change Light orange-red Comparative Example 2 No color change Light orange-red Pale - - Comparative Example 3 Light orange-red Pale - - - As shown in Table 1, the sample in Example 1 did not change color significantly after aging for 250 minutes, indicating that the photothermal stabilized color powder composed of zinc dicyclopentadiene dicarboxylate, orange, bright red, antioxidant, and ultraviolet absorber has a stable structure. The antioxidant and ultraviolet absorber have a synergistic effect with zinc dicyclopentadiene dicarboxylate, which can better improve the weather resistance of the masterbatch. The sample of Comparative Example 1 changed color slightly after aging for 200 min, indicating that zinc dicyclopentadiene dicarboxylate helps maintain the continuous stability of the color masterbatch. Comparative Example 2 sample showed good anti-aging properties in the initial stage, but could not maintain them for a long time, indicating that zinc dicyclopentadiene dicarboxylate needs to be combined with antioxidants and ultraviolet absorbers for synergistic effects. The poor anti-aging performance of the three splines indicates that it is difficult for a single color masterbatch to maintain stability.

[0013] Experiment Example 2: Machining Performance Test The color masterbatches obtained in Example 1 and Comparative Examples 1-3 were subjected to melt flow rate experiments according to Method A of GB / T 3682.1-2018.

[0014] Table 2. Experimental results of melt flow rate of color masterbatches prepared in Example 1, Comparative Example 1, and Comparative Example 3. Serial Number Photothermal stabilized color powder Melt flow index (150℃ / 2.16kg) Example 1 Zinc dicyclopentadiene dicarboxylate, orange, scarlet, antioxidant, UV absorber and dispersant 6.5g / 10min Comparative Example 1 Orange, bright red, antioxidants, UV absorbers and dispersants 6.2g / 10min Comparative Example 2 Zinc dicyclopentadiene dicarboxylate, orange, bright red 7.1g / 10min Comparative Example 3 Orange and bright red 3.2g / 10min As shown in Table 2, the melt flow rate of the masterbatch of Example 1 and Comparative Examples 1 and 2 is higher than that of Comparative Example 3. The dispersant can not only effectively improve the dispersibility of the color powder, but also play a lubricating role in the processing, resulting in good processing fluidity. At the same time, the dicyclopentadiene in zinc dicyclopentadiene dicarboxylate has thermally reversible crosslinking properties, which dedimerizes during hot processing, resulting in good processing fluidity.

[0015] Experimental Example 3: Material Mechanical Property Test The modified polypropylene specimens obtained in Example 1 and Comparative Examples 1-3 were subjected to impact strength tests according to GB / T 1043.1-2008; and tensile strength tests according to GB / T 1040.2-2022.

[0016] Table 3 Impact strength and tensile strength of the specimens obtained in Example 1 and Comparative Examples 1-3 Serial Number Photothermal stabilized color powder Impact strength retention rate Tensile strength retention Example 1 Zinc dicyclopentadiene dicarboxylate, orange, scarlet, antioxidant, UV absorber and dispersant 100% 100% Comparative Example 1 Orange, bright red, antioxidants, UV absorbers and dispersants 85% 90% Comparative Example 2 Zinc dicyclopentadiene dicarboxylate, orange, bright red 100% 100% Comparative Example 3 Orange and bright red 85% 90% As shown in Table 3, the impact strength retention rate and tensile strength retention rate of Example 1 and Comparative Example 2 are better than those of Comparative Example 1 and Comparative Example 3. The dicyclopentadiene in zinc dicyclopentadiene dicarboxylate has thermally reversible crosslinking properties. After cooling, it undergoes recyclization and addition dimerization to crosslink, which helps to provide a stable structure and ensure the mechanical properties of the material.

[0017] The preferred embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various modifications or variations within the scope of the claims, which do not affect the essence of the present invention.

Claims

1. A weather-resistant masterbatch for modified polypropylene cable protection pipes and its preparation method, characterized in that: The aforementioned weather-resistant modified polypropylene cable sheath color masterbatch is composed of carrier resin, photothermal stabilized color powder, filler, and graft compatibility modifier. The composition includes 100 parts by weight of carrier resin, 60-80 parts by weight of photothermal stabilized color powder, 180-200 parts by weight of filler, and 8-20 parts by weight of graft compatibility modifier. The photothermal stabilized color powder is composed of zinc dicyclopentadiene dicarboxylate, orange, scarlet, antioxidant, ultraviolet absorber and dispersant; The orange-yellow color is an azo pigment with the molecular formula C. 32 H 24 Cl2N8O2; The crimson pigment is an azo pigment with the molecular formula C. 18 H 11 BaClN2O6S; The antioxidant is composed of high molecular weight hindered phenolic antioxidant AT1010 and phosphite antioxidant AT168, in a weight ratio of 1:

1. The ultraviolet absorber is UV-531, 2-hydroxy-4-n-octyloxybenzophenone, with the molecular formula C. 21 H 26 O3; The dispersant is composed of stearic acid and polyethylene wax in a weight ratio of 1:2; The composition includes 100 parts by weight of orange, 100 parts by weight of scarlet, 80-100 parts by weight of zinc dicyclopentadienedicarboxylate, 1-10 parts by weight of antioxidant, 1-10 parts by weight of ultraviolet absorber, and 5-10 parts by weight of dispersant.

2. The modified polypropylene cable protection pipe weather-resistant masterbatch and its preparation method according to claim 1, characterized in that, The preparation method of photothermal stabilized color powder includes the following steps: Step 1: At 170℃, an equivalent amount of dicyclopentadiene is heated to decompose into cyclopentadiene. An equivalent amount of sodium sand is added to the cyclopentadiene ether solution, and then an equivalent amount of carbon dioxide is introduced. After cooling to room temperature, sodium dicyclopentadiene dicarboxylate is obtained. It is then washed, filtered, and dried for later use. Step 2: Dissolve an equivalent amount of zinc chloride in an aqueous solution to obtain a zinc chloride aqueous solution. Add the solution of sodium dicyclopentadiene dicarboxylate obtained in Step 1 to the solution in water. Stir at 0~100℃ for 5~10h to obtain a precipitate of zinc dicyclopentadiene dicarboxylate. Step 3: Wash, filter, and dry the precipitate obtained in Step 2 for later use; Step 4: Add orange and red to the zinc dicyclopentadiene dicarboxylate obtained in Step 3, and mix thoroughly for 10-20 minutes at 180-200°C using a high-speed mixer. Step 5: Add the antioxidant, UV absorber and dispersant to the mixture obtained in step 4, and mix thoroughly at 80~100℃ for 10~30 minutes using a high-speed mixer.

3. The weather-resistant masterbatch for modified polypropylene cable protection pipes and its preparation method according to claim 1, characterized in that: The carrier resin is LLDPE resin with a melt index between 2 and 10 g / 10 min, particularly between 5 and 6 g / 10 min.

4. The weather-resistant masterbatch for modified polypropylene cable protection pipes and its preparation method according to claim 1, characterized in that, The filler is composed of organic calcium carbonate and organic talc in a weight ratio of 2:1, and both organic calcium carbonate and organic talc are 800 mesh.

5. The modified polypropylene cable protection pipe weather-resistant masterbatch and its preparation method according to claim 1, characterized in that, The graft compatibility modifier is PP-g-MAH.

6. The weather-resistant masterbatch for modified polypropylene cable protection pipes and its preparation method according to claim 1, characterized in that, A method for preparing a color masterbatch for weather-resistant modified polypropylene cable sheathing is as follows: Step 1: Weigh the carrier resin, photothermal stabilized color powder, filler, and graft compatibility modifier according to the weight ratio of the aforementioned weather-resistant modified polypropylene cable sheath color masterbatch, and then mix them thoroughly in a high-speed mixer at 100~120℃ for 1~2 hours. Step 2: The mixture obtained in Step 1 is taken out and melt-extruded through a twin-screw extruder. It is then cooled and shaped by cooling water, and continuously and stably pulled out by a traction machine for granulation, thus obtaining a weather-resistant modified polypropylene cable sheathing masterbatch. The extruder temperature is as follows: first stage: 120~140℃; second stage: 150~180℃; third stage: 190~210℃. The fourth temperature is 210℃, the die temperature is 210℃, the die head vacuum is controlled at 0.02~0.05MPa, the cooling water temperature is controlled at 30~45℃, and the traction pressure is controlled at 0.02~0.05MPa.

7. The modified polypropylene cable protection pipe weather-resistant masterbatch and its preparation method according to claim 1, characterized in that, A weather-resistant masterbatch for modified polypropylene cable protection pipes is applied to the preparation of modified polypropylene cable protection pipes. The method is as follows: 100 parts by weight of polypropylene and 1 part by weight of the weather-resistant masterbatch for modified polypropylene cable protection pipes are weighed according to the weight ratio and then fully mixed in a high-speed mixer at 100~120℃ for 1~2 hours; the resulting mixture is taken out and melt-extruded through a twin-screw extruder, then cooled and shaped by cooling water, and continuously and stably pulled out by a traction machine. The temperature of barrel zone 1 is 160~180℃, barrel zone 2 is 170~190℃, barrel zone 3 is 180~200℃, barrel zone 4 is 170~190℃, and barrel zone 5 is 150~170℃. The extrusion molding speed is 0.5m / min, the die vacuum degree is controlled at 0.03~0.05MPa, the cooling water temperature is controlled at 25~45℃, and the traction pressure is controlled at 0.03~0.05MPa.