Color-tunable flame-retardant antistatic polypropylene composition for pipes and process for the preparation thereof

Abstract

The present application provides a kind of color adjustable flame-retardant antistatic polypropylene composition for pipeline, its preparation method and the pipeline prepared from it.The composition comprises the following components: (1) the total amount of first polypropylene and second polypropylene is 70-80 parts by weight; wherein the melt flow rate of first polypropylene is 0.2-1 g / 10 min, and the melt flow rate of second polypropylene is 2-5 g / 10 min; (2) 0.5-1.5 parts by weight of carbon nanotube; (3) 8-20 parts by weight of flame retardant; (4) 0.5-1 parts by weight of surface modifier; (5) 0.5-1.5 parts by weight of compatibilizer; (6) optional pigment; and (7) optional other auxiliary agent.The electric polypropylene composition has excellent processing, flame-retardant, antistatic properties, product color can be adjusted to color, can be applied to the field of mine color pipeline, etc.

Description

Technical Field

[0001] This invention belongs to the field of flame-retardant and antistatic materials. Specifically, it relates to a color-adjustable flame-retardant and antistatic polypropylene composition for pipes, its preparation method, and pipes made therefrom. Background Technology

[0002] Polypropylene is a common general-purpose plastic, widely used in agriculture, construction, electronics, and packaging due to its low cost, light weight, chemical resistance, and corrosion resistance. It is typically used to manufacture pipes, sheets, and films. However, polypropylene has high insulation properties and is flammable. Its high surface resistivity also makes it prone to static electricity buildup.

[0003] In specialized fields such as coal mines, static electricity generated during the transport of media by mining pipelines poses a significant safety hazard. Therefore, mining pipelines must meet the flame-retardant and antistatic requirements specified in the MT 181-1988 standard. Polyolefin pipes are commonly used plastic pipes, but existing polyolefins generally suffer from poor antistatic properties, low pressure resistance, and low strength, greatly limiting their application. Therefore, to meet the application requirements of polyolefin pipes in underground coal mines, a certain amount of antistatic agents and flame retardants are typically added to the polyolefin to satisfy the flame-retardant and antistatic performance requirements. Antistatic agents meeting these requirements are generally black conductive media such as carbon black and graphene. Therefore, the resulting pipes must be black in appearance.

[0004] Underground coal mine pipelines are categorized by purpose into water supply pipes, drainage pipes, compressed air pipes, grouting pipes, and gas extraction pipes. These different types of pipelines are laid overhead along the tunnel walls, and all are black. When an anomaly occurs in the tunnel and pipelines need to be opened or closed, it is impossible to quickly identify the medium being transported and its specific purpose in each pipeline, thus affecting the efficiency of handling anomalies. Generally, coal mines use bright green for water supply pipelines, blue for drainage pipelines, light gray for compressed air pipelines, cyan for grouting pipelines, and medium yellow for nitrogen injection pipelines. Currently, mines identify the types of media transported in pipelines by affixing identification signs, but these have low visibility and are prone to falling off; relying on the pipes' own color markings often lack anti-static properties; applying short-lasting colored anti-static agents is also problematic as they are prone to failure and cannot meet long-term use requirements; and some mines even use colored pipes that lack anti-static properties, posing extremely high risks for underground use. Therefore, the development of permanent, intrinsically safe, colored, flame-retardant, and antistatic polypropylene materials for use in mining pipelines is of great significance.

[0005] In existing technologies, the improvement of flame-retardant and antistatic properties is achieved through modification by adding flame retardants, antistatic agents, etc., and then blending them. For example, Chinese patent application CN201410638892.8 discloses an antistatic and antibacterial masterbatch and its preparation method; Chinese patent application CN201911274784.6 discloses a permanent colored antistatic and flame-retardant polyolefin steel wire composite pipe, its preparation method and mold; and Chinese patent application CN201010100077.8 discloses an antistatic polyethylene and its preparation method. Although using permanent polymeric antistatic agents, such as hydrophilic polymers, such as polyoxyethylene-polyamide composites, octadecylamine polyoxyethylene ether, dodecylamine polyoxyethylene ether, and ethylene-acrylic acid copolymers, can meet the requirements of less demanding antistatic applications, the required addition amount is relatively high. In addition, because these hydrophilic polymers have poor compatibility with polypropylene, the mechanical properties of the resulting products are significantly reduced, especially indicators such as elongation at break and impact strength, affecting the pressure resistance and safety of the pipes.

[0006] Carbon nanotubes have attracted significant attention due to their unique small size and surface area effects. They have found applications in various fields, including quantum wires, composite materials, hydrogen storage materials, and lithium-ion batteries. This study utilizes the extremely high aspect ratio of carbon nanotubes to fabricate a 3D conductive network that runs throughout a polymer substrate. However, carbon nanotubes exhibit poor dispersibility and are prone to aggregation in PP (polypropylene) substrates.

[0007] No color-adjustable flame-retardant and antistatic polypropylene compositions have been reported in the prior art. Summary of the Invention

[0008] To address the aforementioned problems in the prior art, the present invention provides a color-adjustable flame-retardant and antistatic polypropylene composition for pipes, a preparation method thereof, and articles comprising the composition.

[0009] According to one aspect of the present invention, a color-adjustable flame-retardant and antistatic polypropylene composition for pipes is provided, comprising the following components:

[0010] (1) The first polypropylene and the second polypropylene, the total amount of which is 70 to 80 parts by weight, preferably 70 to 75 parts by weight; wherein the melt flow rate of the first polypropylene is 0.2 to 1 g / 10 min as measured by ISO 1133 under the conditions of 230°C and 2.16 kg load, and the melt flow rate of the second polypropylene is 2 to 5 g / 10 min as measured by ISO 1133 under the conditions of 230°C and 2.16 kg load.

[0011] (2) Carbon nanotubes: 0.5 to 1.5 parts by weight, preferably 0.5 to 1.0 parts by weight;

[0012] (3) Flame retardant: 8-20 parts by weight;

[0013] (4) Surface modifier: 0.5 to 1 part by weight;

[0014] (5) Compatibilizer: 0.5 to 1.5 parts by weight;

[0015] (6) Optional pigments: 5-10 parts by weight, preferably 4.5-6 parts by weight; and

[0016] (7) Optional other additives: 0.3 to 2 parts by weight.

[0017] Preferably, the carbon nanotubes are single-walled carbon nanotubes.

[0018] Preferably, the carbon nanotubes have an average diameter of 1.0–5.0 nm, a length of 5–50 μm, and a specific surface area of ​​800–2000 m². 2 / g, G / D ratio is 20-50.

[0019] Preferably, the weight-average molecular weight of the first polypropylene is greater than or equal to 400,000; and the weight-average molecular weight of the second polypropylene is greater than or equal to 300,000.

[0020] Preferably, the weight ratio of the first polypropylene to the second polypropylene is 3 to 5:1, more preferably 4:1.

[0021] Preferably, the pigment can be a pigment conventionally used in the art, such as one or more selected from titanium dioxide, phthalocyanine blue, phthalocyanine green, Brilliant Yellow, and Clear Red. Such pigments are manufactured and sold by companies such as DuPont, BASF, and Bayer.

[0022] Preferably, the flame retardant comprises 6-16 parts by weight, more preferably 8-14 parts by weight, of a primary flame retardant and 3-6 parts by weight, more preferably 3-5 parts by weight, of a flame retardant synergist. The primary flame retardant is preferably a halogenated flame retardant, for example, selected from one or more aromatic brominated compounds, cycloaliphatic brominated compounds, and aliphatic brominated compounds, more preferably decabromodiphenyl ethane and / or decabromodiphenyl ether. The flame retardant synergist is one or more of antimony trioxide, zinc borate, and nitrogen-based flame retardants (such as melamine and / or melamine cyanuric acid), preferably antimony trioxide.

[0023] Preferably, the surface modifier is selected from titanate coupling agents and silane coupling agents, and more preferably a silane coupling agent.

[0024] Preferably, the compatibilizer is a polar monomer-grafted polymer; more preferably, the polar monomer is one or more selected from acid anhydrides, carboxylic acids, carboxylic acid derivatives, amino compounds, hydroxyl compounds, epoxy compounds, and ionic compounds; more preferably, the compatibilizer is maleic anhydride-grafted polypropylene (PP-g-MAH) or glycidyl methacrylate-grafted polypropylene (PP-g-GMA), and more preferably, maleic anhydride-grafted propylene homopolymer. Preferably, the maleic anhydride-grafted polypropylene has a melt flow rate of 10–400 g / 10 min, more preferably 50–200 g / 10 min, measured according to ISO 1133, at 230°C and a load of 2.16 kg. According to the present invention, the grafting rate of maleic anhydride in the maleic anhydride-grafted polypropylene is preferably 1–2%, more preferably 1.2–1.5%.

[0025] Preferably, the other additives may include, but are not limited to, the following: antioxidants, lubricants, anti-photoaging agents, heat stabilizers, superdispersants, etc.

[0026] Preferably, the melt flow rate of the color-adjustable flame-retardant and antistatic polypropylene composition for the pipeline, measured under conditions of 230°C and 2.16 kg load, is 0.1–0.8 g / 10 min, more preferably 0.3–0.7 g / 10 min;

[0027] Preferably, the surface resistivity of the color-adjustable flame-retardant and antistatic polypropylene composition used in the pipeline, measured according to the Chinese Coal Mine Industry Standard MT 113-1995, is less than 3 × 10⁻⁶. 8 Ω.

[0028] Preferably, the flame-retardant and antistatic polypropylene composition for the pipeline, which has adjustable color, has flame-retardant properties measured according to the Chinese Coal Mine Industry Standard MT 113-1995. After removing the alcohol torch, the arithmetic mean of the flame burning of the specimen should not exceed 3 seconds, the arithmetic mean of the flameless burning of the specimen should not exceed 10 seconds, and the flame propagation length should not exceed 280 mm.

[0029] According to a second aspect of the present invention, a method for preparing a color-tunable flame-retardant and antistatic polypropylene composition for pipes according to the present invention is provided, comprising the following steps:

[0030] (1) The second polypropylene, carbon nanotubes, surface modifier, compatibilizer, optional pigment and optional other additives are added to a mixer in sequence and mixed thoroughly, and then extruded to prepare granular additive packages.

[0031] Preferably, the mixing temperature of the mixer is 40-80°C, the mixing time is 3-5 minutes, the extrusion temperature of the extruder is 180-220°C, and the extruder speed is 300 rpm.

[0032] (2) Add the flame retardant to a mixer and mix thoroughly. Preferably, the speed of the mixer is 100 rpm and the mixing time is 3 to 5 minutes.

[0033] (3) The first polypropylene is fed to the main feed loss scale. The granulated additive package obtained in step (1) and the flame retardant obtained in step (2) are respectively transported to the side feed loss scale through the vacuum feeding device. The materials are added by the main feed and forced side feed of the extruder to prepare a flame retardant and antistatic polypropylene composition with adjustable color for pipelines.

[0034] Preferably, the carbon nanotubes are produced through a multi-stage process to ensure the aspect ratio and uniform dispersion of the formulation. The extrusion temperature is 190-230℃, the extruder speed is 200rpm, and after cooling, they are cut into 2-5mm particles by a pelletizer.

[0035] According to a third aspect of the invention, a pipe is provided made of a color-adjustable flame-retardant and antistatic polypropylene composition according to the invention.

[0036] This invention selects carbon nanotubes with high specific surface area and high G / D ratio, and uses functionalized surface treatment and granular pre-dispersion processes. Through melt flow regulation and multi-stage dispersion, the carbon nanotubes form a conductive percolation network at a low addition amount, thereby mitigating the adverse effects of black conductive filler on color. By adjusting the pigment and its dosage, a color-adjustable polypropylene composition with good flame retardancy and antistatic properties can be prepared. This provides a polypropylene composition with excellent flame retardancy, antistatic properties, and superior mechanical properties, as well as its preparation method. The color-adjustable flame-retardant and antistatic polypropylene composition for pipelines according to this invention exhibits excellent flame-retardant and antistatic properties and can be applied in fields such as colored pipelines for mining. Detailed Implementation

[0037] The present invention will be described in detail with reference to the following embodiments; however, these embodiments are only used to describe the present invention and the present invention is not limited to these embodiments.

[0038] The methods used to measure performance in the embodiments are shown below.

[0039] The present invention will be described in detail below through embodiments.

[0040] In the following examples and comparative examples,

[0041] Melt flow rate was tested according to standard ISO 1133 (230℃, 2.16kg load);

[0042] Flame retardant performance was tested according to Chinese Coal Mine Industry Standard MT 113-1995;

[0043] The antistatic properties were tested according to the Chinese Coal Mine Industry Standard MT 113-1995;

[0044] Color was determined by visual inspection.

[0045] All raw materials used in the implementation example are as follows:

[0046] Polypropylene: Yanshan Petrochemical's 8101 (MI = 0.38 g / 10 min, 2.16 kg, 230 °C);

[0047] Polypropylene: Yanshan Petrochemical's K8303 (MI = 2.80 g / 10 min, 2.16 kg, 230 ℃);

[0048] Carbon nanotube 1: Diameter 1.6 nm, length 10 μm, specific surface area 1000 m² 2 / g, G / D = 40;

[0049] Carbon nanotube 2: 10 nm in diameter, 50 μm in length, and 300 m² in specific surface area. 2 / g, G / D=5;

[0050] Titanium dioxide: DuPont's R105;

[0051] Phthalocyanine Blue: BASF's Heliogen K7090;

[0052] Phthalocyanine green: BASF's Heliogen K8730;

[0053] Cromophy: BASF's Cromophytal 2030;

[0054] Yan Jiali Huang: BASF's Irgalite WGP;

[0055] Czech conductive carbon black: CHEZACARB AC80;

[0056] Decabromodiphenyl ethane: Albemarle's 8010;

[0057] Antimony trioxide: China Flashstar Antimony Industry Co., Ltd., effective content >99.8%;

[0058] PP-g-MAH was prepared in-house, and the preparation process is as follows: 100 parts by weight of PP, 0.5 parts by weight of 2,5-dimethyl-2,5-bis(tert-butylperoxide)hexane and 2.5 parts by weight of maleic anhydride were mixed evenly in a high-speed mixer, and then extruded and granulated by a twin-screw extruder (extrusion temperature 150-200℃, main machine speed 200r / min) to obtain PP-g-MAH with a grafting rate of 1.5%;

[0059] Octyltriethoxysilane: SICO-N823 from Shandong Silicon Science New Materials Co., Ltd.;

[0060] Super dispersant, Solplus from Lubrizol Ltd. TM DP320;

[0061] Antioxidant: BASF's B 225.

[0062] Unless otherwise specified, in this invention, "parts" refers to parts by weight.

[0063] Example 1

[0064] (1) 15 parts of polypropylene K8303 (MI = 2.80 g / 10 min, 2.16 kg, 230 ℃) and 0.5 parts of carbon nanotubes (diameter 1.6 nm, length 10 μm, specific surface area 1000 m²) were mixed. 2 / g, G / D = 40), 4 parts titanium dioxide (R105), 2 parts phthalocyanine blue (Heliogen K7090), 1 part MAH-g-PP (grafting rate 1.5%), 0.5 parts silane coupling agent (octyltriethoxysilane, SICO-N823), 0.7 parts superdispersant (Solplus) TM DP320 and 0.5 parts antioxidant (BASF B225) are added sequentially to a high-speed mixer and thoroughly mixed to obtain a polypropylene mixed resin. The mixing temperature of the high-speed mixer is 40-80℃ and the mixing time is 3-5 minutes. Finally, a high-concentration granulated additive package is obtained by granulation through an extruder. The extrusion temperature is 180-220℃ and the extruder speed is 300 rpm.

[0065] (2) Add 16 parts of flame retardant composition (12 parts of decabromodiphenyl ethane (brand name 8010, Albemarle, USA) and 4 parts of antimony trioxide (effective content >99.8%, China Shining Antimony Industry Co., Ltd.) to a high-speed mixer and mix thoroughly. The speed of the high-speed mixer is 100 rpm and the mixing time is 3 to 5 minutes.

[0066] (3) 60 parts of low-flow polypropylene 8101 (8101, MI = 0.38 g / 10 min, 2.16 kg, 230 °C) in the polypropylene composition were fed to the main feed loss weigher. The high-concentration granulated additive package obtained in step (1) and the flame retardant composition in step (2) were respectively transported to the side feed loss weigher through a vacuum feeding device. The materials were added by the main feeder and forced side feeder of the extruder. The multi-stage process ensured the length-to-diameter ratio of the carbon tube and the uniform dispersion of the formulation. The extrusion temperature was 190-230 °C and the extruder speed was 200 rpm. After cooling, the particles were cut into 2-5 mm particles by a pelletizer to prepare the colored flame retardant and antistatic polypropylene composition for pipes.

[0067] The performance test results of the colored flame-retardant and antistatic polypropylene composition used in this pipeline are as follows: color is blue, melt flow rate is 0.666 g / 10 min, and surface resistivity is 1*10. 7 Ω, Flame retardant performance: Qualified.

[0068] Example 2

[0069] (1) 14.75 parts of polypropylene K8303 (MI = 2.80 g / 10 min, 2.16 kg, 230 ℃) and 0.75 parts of carbon nanotubes (diameter 1.6 nm, length 10 μm, specific surface area 1000 m²) were added. 2 / g, G / D=40), 4 parts titanium dioxide (DuPont R105), 0.3 parts Cromophy Red (BASF Cromophytal 2030), 2.7 parts Irgalite Yellow (BASF Irgalite WGP), 1 part MAH-g-PP (grafting rate 1.5%), 0.5 parts silane coupling agent (octyltriethoxysilane, SICO-N823), 0.7 parts superdispersant (Solplus) TM DP320 and 0.5 parts antioxidant (BASF B225) are added sequentially to a high-speed mixer and thoroughly mixed to obtain a polypropylene mixed resin. The mixing temperature of the high-speed mixer is 40-80℃ and the mixing time is 3-5 minutes. Finally, a high-concentration granulated additive package is obtained by granulation through an extruder. The extrusion temperature is 180-220℃ and the extruder speed is 300 rpm.

[0070] (2) Add 16 parts of flame retardant composition (12 parts of decabromodiphenyl ethane (brand name 8010, Albemarle, USA) and 4 parts of antimony trioxide (effective content >99.8%, China Shining Antimony Industry Co., Ltd.) to a high-speed mixer and mix thoroughly. The speed of the high-speed mixer is 100 rpm and the mixing time is 3 to 5 minutes.

[0071] (3) 59 parts of low-flow polypropylene 8101 (8101, MI = 0.38 g / 10 min, 2.16 kg, 230 °C) in the polypropylene composition were fed to the main feed loss weigher. The high-concentration granulated additive package obtained in step (1) and the flame retardant composition in step (2) were respectively transported to the side feed loss weigher through a vacuum feeding device. The materials were added by the main feeder and forced side feeder of the extruder. The multi-stage process ensured the length-to-diameter ratio of the carbon tube and the uniform dispersion of the formulation. The extrusion temperature was 190-230 °C and the extruder speed was 200 rpm. After cooling, the particles were cut into 2-5 mm particles by a pelletizer to prepare the colored flame retardant and antistatic polypropylene composition for pipes.

[0072] The performance test results of the colored flame-retardant and antistatic polypropylene composition used in this pipeline are as follows: color is yellow, melt flow rate is 0.588 g / 10 min, and surface resistivity is 1*10. 6 Ω, Flame retardant performance: Qualified.

[0073] Example 3

[0074] (1) 14.5 parts of polypropylene K8303 (MI = 2.80 g / 10 min, 2.16 kg, 230 ℃) and 1.0 part of carbon nanotubes (diameter 1.6 nm, length 10 μm, specific surface area 1000 m²) were added. 2 / g, G / D=40), 5 parts titanium dioxide (DuPont R105), 2.25 parts Cromophy Red (BASF Cromophytal 2030), 0.75 parts Irgalite Yellow (BASF Irgalite WGP), 1 part MAH-g-PP (grafting rate 1.5%), 0.5 parts silane coupling agent (octyltriethoxysilane, SICO-N823), 0.7 parts superdispersant (Solplus) TM DP320 and 0.5 parts antioxidant (BASF B225) are added sequentially to a high-speed mixer and thoroughly mixed to obtain a polypropylene mixed resin. The mixing temperature of the high-speed mixer is 40-80℃ and the mixing time is 3-5 minutes. Finally, a high-concentration granulated additive package is obtained by granulation through an extruder. The extrusion temperature is 180-220℃ and the extruder speed is 300 rpm.

[0075] (2) Add 16 parts of flame retardant composition (12 parts of decabromodiphenyl ethane (brand name 8010, Albemarle, USA) and 4 parts of antimony trioxide (effective content >99.8%, China Shining Antimony Industry Co., Ltd.) to a high-speed mixer and mix thoroughly. The speed of the high-speed mixer is 100 rpm and the mixing time is 3 to 5 minutes.

[0076] (3) 58 parts of low-flow polypropylene 8101 (8101, MI = 0.38 g / 10 min, 2.16 kg, 230 °C) in the polypropylene composition were fed to the main feed loss weigher. The high-concentration granulated additive package obtained in step (1) and the flame retardant composition in step (2) were respectively transported to the side feed loss weigher through a vacuum feeding device. The materials were added by the main feeder and forced side feeder of the extruder. The multi-stage process ensured the length-to-diameter ratio of the carbon tube and the uniform dispersion of the formulation. The extrusion temperature was 190-230 °C and the extruder speed was 200 rpm. After cooling, the material was cut into 2-5 mm particles by a pelletizer to prepare a colored flame retardant and antistatic polypropylene composition for pipes.

[0077] The performance test results of the colored flame-retardant and antistatic polypropylene composition used in this pipeline are as follows: color is red, melt flow rate is 0.550 g / 10 min, and surface resistivity is 3*10. 5 Ω, Flame retardant performance: Qualified.

[0078] Example 4

[0079] (1) 14.5 parts of polypropylene K8303 (MI = 2.80 g / 10 min, 2.16 kg, 230 °C), 1.0 part of carbon nanotubes (diameter 1.6 nm, length 10 μm, specific surface area 1000 m² / g, G / D = 40), 5 parts of titanium dioxide (DuPont R105), 3 parts of phthalocyanine green (BASF Heliogen K8730), 1 part of MAH-g-PP (grafting rate 1.5%), 0.5 parts of silane coupling agent (octyltriethoxysilane, SICO-N823), and 0.7 parts of superdispersant (Solplus) were added. TM DP320 and 0.5 parts antioxidant (BASF B225) are added sequentially to a high-speed mixer and thoroughly mixed to obtain a polypropylene mixed resin. The mixing temperature of the high-speed mixer is 40-80℃ and the mixing time is 3-5 minutes. Finally, a high-concentration granulated additive package is obtained by granulation through an extruder. The extrusion temperature is 180-220℃ and the extruder speed is 300 rpm.

[0080] (2) Add 16 parts of flame retardant composition (12 parts of decabromodiphenyl ethane (brand name 8010, Albemarle, USA) and 4 parts of antimony trioxide (effective content >99.8%, China Shining Antimony Industry Co., Ltd.) to a high-speed mixer and mix thoroughly. The speed of the high-speed mixer is 100 rpm and the mixing time is 3 to 5 minutes.

[0081] (3) 58 parts of low-flow polypropylene 8101 (8101, MI = 0.38 g / 10 min, 2.16 kg, 230 °C) in the polypropylene composition were fed to the main feed loss weigher. The high-concentration granulated additive package obtained in step (1) and the flame retardant composition in step (2) were respectively transported to the side feed loss weigher through a vacuum feeding device. The materials were added by the main feeder and forced side feeder of the extruder. The multi-stage process ensured the length-to-diameter ratio of the carbon tube and the uniform dispersion of the formulation. The extrusion temperature was 190-230 °C and the extruder speed was 200 rpm. After cooling, the material was cut into 2-5 mm particles by a pelletizer to prepare a colored flame retardant and antistatic polypropylene composition for pipes.

[0082] The performance test results of the colored flame-retardant and antistatic polypropylene composition used in this pipeline are as follows: color is green, melt flow rate is 0.542 g / 10 min, and surface resistivity is 3*10. 5 Ω, Flame retardant performance: Qualified.

[0083] Comparative Example 1

[0084] (1) 15.02 parts of polypropylene K8303 (MI = 2.80 g / 10 min, 2.16 kg, 230 ℃), 0.4 parts of carbon nanotubes (diameter 1.6 nm, length 10 μm, specific surface area 1000 m² / g, G / D = 40), 4 parts of titanium dioxide (DuPont R105), 2 parts of phthalocyanine blue (Heliogen K7090), 1 part of MAH-g-PP (grafting rate 1.5%), 0.5 parts of silane coupling agent (octyltriethoxysilane, SICO-N823), and 0.7 parts of superdispersant (Solplus) were added. TM DP320 and 0.5 parts antioxidant (BASF B225) are added sequentially to a high-speed mixer and thoroughly mixed to obtain a polypropylene mixed resin. The mixing temperature of the high-speed mixer is 40-80℃ and the mixing time is 3-5 minutes. Finally, a high-concentration granulated additive package is obtained by granulation through an extruder. The extrusion temperature is 180-220℃ and the extruder speed is 300 rpm.

[0085] (2) Add 16 parts of flame retardant composition (12 parts of decabromodiphenyl ethane (brand name 8010, Albemarle, USA) and 4 parts of antimony trioxide (effective content >99.8%, China Shining Antimony Industry Co., Ltd.) to a high-speed mixer and mix thoroughly. The speed of the high-speed mixer is 100 rpm and the mixing time is 3 to 5 minutes.

[0086] (3) 60.08 parts of low-flow polypropylene 8101 (8101, MI = 0.38 g / 10 min, 2.16 kg, 230 °C) in the polypropylene composition were fed to the main feed loss scale. The high-concentration granulated additive package obtained in step (1) and the flame retardant composition in step (2) were respectively transported to the side feed loss scale through a vacuum feeding device. The materials were added by the main feed and forced side feed of the extruder. The multi-stage process ensured the length-to-diameter ratio of the carbon tube and the uniform dispersion of the formulation. The extrusion temperature was 190-230 °C and the extruder speed was 200 rpm. After cooling, the material was cut into 2-5 mm particles by a pelletizer to prepare a colored flame retardant and antistatic polypropylene composition for pipes.

[0087] The performance test results of the colored flame-retardant and antistatic polypropylene composition used in this pipeline are as follows: color is blue, melt flow rate is 0.722 g / 10 min, and surface resistivity is ≥1*10. 12 Ω, Flame retardant performance: Qualified.

[0088] Comparative Example 2

[0089] (1) 14.5 parts of polypropylene K8303 (MI = 2.80 g / 10 min, 2.16 kg, 230 ℃) and 1.0 part of carbon nanotubes (diameter 10 nm, length 50 μm, specific surface area 300 m²) were added. 2 / g, G / D=5), 5 parts titanium dioxide (DuPont R105), 3 parts phthalocyanine green (BASF Heliogen K8730), 1 part MAH-g-PP (grafting rate 1.5%), 0.5 parts silane coupling agent (octyltriethoxysilane, SICO-N823), 0.7 parts superdispersant (Solplus) TM DP320 and 0.5 parts antioxidant (BASF B225) are added sequentially to a high-speed mixer and thoroughly mixed to obtain a polypropylene mixed resin. The mixing temperature of the high-speed mixer is 40-80℃ and the mixing time is 3-5 minutes. Finally, a high-concentration granulated additive package is obtained by granulation through an extruder. The extrusion temperature is 180-220℃ and the extruder speed is 300 rpm.

[0090] (2) Add 16 parts of flame retardant composition (12 parts of decabromodiphenyl ethane (brand name 8010, Albemarle, USA) and 4 parts of antimony trioxide (effective content >99.8%, China Shining Antimony Industry Co., Ltd.) to a high-speed mixer and mix thoroughly. The speed of the high-speed mixer is 100 rpm and the mixing time is 3 to 5 minutes.

[0091] (3) 58 parts of low-flow polypropylene 8101 (8101, MI = 0.38 g / 10 min, 2.16 kg, 230 °C) in the polypropylene composition were fed to the main feed loss weigher. The high-concentration granulated additive package obtained in step (1) and the flame retardant composition in step (2) were respectively transported to the side feed loss weigher through a vacuum feeding device. The materials were added by the main feeder and forced side feeder of the extruder. The multi-stage process ensured the length-to-diameter ratio of the carbon tube and the uniform dispersion of the formulation. The extrusion temperature was 190-230 °C and the extruder speed was 200 rpm. After cooling, the material was cut into 2-5 mm particles by a pelletizer to prepare a colored flame retardant and antistatic polypropylene composition for pipes.

[0092] The performance test results of the colored flame-retardant and antistatic polypropylene composition used in this pipeline are as follows: color is green, melt flow rate is 0.526 g / 10 min, and surface resistivity is ≥1*10. 12 Ω, Flame retardant performance: Qualified.

[0093] Comparative Example 3

[0094] (1) 14.0 parts of polypropylene K8303 (MI = 2.80 g / 10 min, 2.16 kg, 230 °C), 3.5 parts of carbon nanotubes (diameter 10 nm, length 50 μm, specific surface area 300 m² / g, G / D = 5), 5 parts of titanium dioxide (DuPont R105), 3 parts of phthalocyanine green (BASF Heliogen K8730), 1 part of MAH-g-PP (grafting rate 1.5%), 0.5 parts of silane coupling agent (octyltriethoxysilane, SICO-N823), and 0.7 parts of superdispersant (Solplus) were added. TM DP320 and 0.5 parts antioxidant (BASF B225) are added sequentially to a high-speed mixer and thoroughly mixed to obtain a polypropylene mixed resin. The mixing temperature of the high-speed mixer is 40-80℃ and the mixing time is 3-5 minutes. Finally, a high-concentration granulated additive package is obtained by granulation through an extruder. The extrusion temperature is 180-220℃ and the extruder speed is 300 rpm.

[0095] (2) Add 16 parts of flame retardant composition (12 parts of decabromodiphenyl ethane (brand name 8010, Albemarle, USA) and 4 parts of antimony trioxide (effective content >99.8%, China Shining Antimony Industry Co., Ltd.) to a high-speed mixer and mix thoroughly. The speed of the high-speed mixer is 100 rpm and the mixing time is 3 to 5 minutes.

[0096] (3) 56 parts of low-flow polypropylene 8101 (8101, MI = 0.38 g / 10 min, 2.16 kg, 230 °C) in the polypropylene composition were fed to the main feed loss scale. The high-concentration granulated additive package obtained in step (1) and the flame retardant composition in step (2) were respectively transported to the side feed loss scale through a vacuum feeding device. The materials were added by the main feed and forced side feed of the extruder. The multi-stage process ensured the length-to-diameter ratio of the carbon tube and the uniform dispersion of the formulation. The extrusion temperature was 190-230 °C and the extruder speed was 200 rpm. After cooling, the particles were cut into 2-5 mm particles by a pelletizer to prepare the colored flame retardant and antistatic polypropylene composition for pipes.

[0097] The performance test results of the colored flame-retardant and antistatic polypropylene composition used in this pipeline are as follows: color is black, melt flow rate is 0.382 g / 10 min, and surface resistivity is 3*10. 8 Ω, Flame retardant performance: Qualified.

[0098] Comparative Example 4

[0099] (1) Mix 14.3 parts of polypropylene K8303 (MI = 2.80 g / 10 min, 2.16 kg, 230 °C), 2.0 parts of Czech superconducting carbon black (CHEZACARB AC80), 5 parts of titanium dioxide (DuPont R105), 3 parts of phthalocyanine green (BASF Heliogen K8730), 1 part of MAH-g-PP (grafting rate 1.5%), 0.5 parts of silane coupling agent (octyltriethoxysilane, SICO-N823), and 0.7 parts of superdispersant (Solplus). TM DP320 and 0.5 parts antioxidant (BASF B225) are added sequentially to a high-speed mixer and thoroughly mixed to obtain a polypropylene mixed resin. The mixing temperature of the high-speed mixer is 40-80℃ and the mixing time is 3-5 minutes. Finally, a high-concentration granulated additive package is obtained by granulation through an extruder. The extrusion temperature is 180-220℃ and the extruder speed is 300 rpm.

[0100] (2) Add 16 parts of flame retardant composition (12 parts of decabromodiphenyl ethane (brand name 8010, Albemarle, USA) and 4 parts of antimony trioxide (effective content >99.8%, China Shining Antimony Industry Co., Ltd.) to a high-speed mixer and mix thoroughly. The speed of the high-speed mixer is 100 rpm and the mixing time is 3 to 5 minutes.

[0101] (3) 57.2 parts of low-flow polypropylene 8101 (8101, MI = 0.38 g / 10 min, 2.16 kg, 230 °C) in the polypropylene composition were fed to the main feed loss weigher. The high-concentration granulated additive package obtained in step (1) and the flame retardant composition in step (2) were respectively transported to the side feed loss weigher through a vacuum feeding device. The materials were added by the main feeder and forced side feeder of the extruder. The multi-stage process ensured the length-to-diameter ratio of the carbon tube and the uniform dispersion of the formulation. The extrusion temperature was 190-230 °C and the extruder speed was 200 rpm. After cooling, the material was cut into 2-5 mm particles by a pelletizer to prepare a colored flame retardant and antistatic polypropylene composition for pipes.

[0102] The performance test results of the colored flame-retardant and antistatic polypropylene composition used in this pipeline are as follows: color is black, melt flow rate is 0.448 g / 10 min, and surface resistivity is 1*10. 11 Ω, Flame retardant performance: Qualified.

[0103] Comparative Example 5

[0104] (1) Mix 14.0 parts of polypropylene K8303 (MI = 2.80 g / 10 min, 2.16 kg, 230 °C), 3.5 parts of Czech superconducting carbon black (CHEZACARB AC80), 5 parts of titanium dioxide (DuPont R105), 3 parts of phthalocyanine green (BASF Heliogen K8730), 1 part of MAH-g-PP (grafting rate 1.5%), 0.5 parts of silane coupling agent (octyltriethoxysilane, SICO-N823), and 0.7 parts of superdispersant (Solplus). TM DP320 and 0.5 parts antioxidant (BASF B225) are added sequentially to a high-speed mixer and thoroughly mixed to obtain a polypropylene mixed resin. The mixing temperature of the high-speed mixer is 40-80℃ and the mixing time is 3-5 minutes. Finally, a high-concentration granulated additive package is obtained by granulation through an extruder. The extrusion temperature is 180-220℃ and the extruder speed is 300 rpm.

[0105] (2) Add 16 parts of flame retardant composition (12 parts of decabromodiphenyl ethane (brand name 8010, Albemarle, USA) and 4 parts of antimony trioxide (effective content >99.8%, China Shining Antimony Industry Co., Ltd.) to a high-speed mixer and mix thoroughly. The speed of the high-speed mixer is 100 rpm and the mixing time is 3 to 5 minutes.

[0106] (3) 56 parts of low-flow polypropylene 8101 (8101, MI = 0.38 g / 10 min, 2.16 kg, 230 °C) in the polypropylene composition were fed to the main feed loss scale. The high-concentration granulated additive package obtained in step (1) and the flame retardant composition in step (2) were respectively transported to the side feed loss scale through a vacuum feeding device. The materials were added by the main feed and forced side feed of the extruder. The multi-stage process ensured the length-to-diameter ratio of the carbon tube and the uniform dispersion of the formulation. The extrusion temperature was 190-230 °C and the extruder speed was 200 rpm. After cooling, the particles were cut into 2-5 mm particles by a pelletizer to prepare the colored flame retardant and antistatic polypropylene composition for pipes.

[0107] The performance test results of the colored flame-retardant and antistatic polypropylene composition used in this pipe are as follows: color is black, melt flow rate is 0.424 g / 10 min, and surface resistivity is 5*10. 7 Ω, Flame retardant performance: Qualified.

[0108] Compared to Example 1, Comparative Example 1 showed high surface resistivity due to insufficient addition of conductive carbon nanotubes, failing to meet mining requirements. Comparative Example 2, compared to Example 4, also showed high surface resistivity due to carbon nanotubes not meeting performance requirements, failing to meet mining requirements. Comparative Example 3, compared to Example 4, met antistatic performance requirements, but due to excessive carbon nanotube dosage, the product could only be black. Comparative Examples 4 and 5, compared to Example 4, showed gradually decreasing surface resistivity after adding different amounts of Czech carbon black until meeting application requirements, but the color could only be black.

[0109] Although several embodiments of the invention have been shown and described, the invention is not limited to the described embodiments. Rather, those skilled in the art will recognize that any modifications and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is determined by the appended claims and their equivalents.

Claims

1. A color-adjustable flame-retardant and antistatic polypropylene composition for pipes, comprising the following components: (1) First polypropylene and second polypropylene, the total amount of which is 70-80 parts by weight; wherein, The melt flow rate of the first polypropylene, measured according to ISO 1133 at 230°C and 2.16 kg load, is 0.2–1 g / 10 min; the melt flow rate of the second polypropylene, measured according to ISO 1133 at 230°C and 2.16 kg load, is 2–5 g / 10 min. (2) Carbon nanotubes: 0.5–1.5 parts by weight, wherein the carbon nanotubes are single-walled carbon nanotubes; the average diameter of the carbon nanotubes is 1.0–5.0 nm, the length is 5–50 μm, and the specific surface area is 800–2000 m². 2 / g, G / D ratio is 20-50; (3) Flame retardant: 8-20 parts by weight; (4) Surface modifier: 0.5 to 1 part by weight; (5) Compatibilizer: 0.5 to 1.5 parts by weight; (6) Optional pigments: 5-10 parts by weight; and (7) Optional other additives: 0.3 to 2 parts by weight.

2. The color-adjustable flame-retardant and antistatic polypropylene composition for pipes according to claim 1, wherein, The total amount of the first and second polypropylenes is 70-75 parts by weight; and / or The content of carbon nanotubes is 0.5–1.0 parts by weight; and / or The optional pigment content is 4.5 to 6 parts by weight.

3. The color-adjustable flame-retardant and antistatic polypropylene composition for pipes according to claim 1 or 2, wherein, The first polypropylene has a weight-average molecular weight greater than or equal to 400,000; the second polypropylene has a weight-average molecular weight greater than or equal to 300,000.

4. The color-adjustable flame-retardant and antistatic polypropylene composition for pipes according to claim 1 or 2, wherein, The weight ratio of the first polypropylene to the second polypropylene is 3 to 5:

1.

5. The color-adjustable flame-retardant and antistatic polypropylene composition for pipes according to claim 4, wherein, The weight ratio of the first polypropylene to the second polypropylene is 4:

1.

6. The color-adjustable flame-retardant and antistatic polypropylene composition for pipes according to claim 1 or 2, wherein, The pigment is selected from one or more of titanium dioxide, phthalocyanine blue, phthalocyanine green, Brilliant Yellow, and Glamour Red.

7. The color-adjustable flame-retardant and antistatic polypropylene composition for pipes according to claim 1 or 2, wherein, The flame retardant comprises: 6-16 parts by weight of a primary flame retardant and 3-6 parts by weight of a flame retardant synergist. The main flame retardant is a halogenated flame retardant; The flame retardant synergist is one or more of antimony trioxide, zinc borate, and nitrogen-based flame retardants.

8. The color-adjustable flame-retardant and antistatic polypropylene composition for pipes according to claim 7, wherein, The content of the main flame retardant is 8 to 14 parts by weight; and / or The content of the flame retardant synergist is 3 to 5 parts by weight; and / or The primary flame retardant is selected from one or more aromatic brominated compounds, cycloaliphatic brominated compounds, and aliphatic brominated compounds.

9. The color-adjustable flame-retardant and antistatic polypropylene composition for pipes according to claim 8, wherein, The primary flame retardant is decabromodiphenyl ethane and / or decabromodiphenyl ether; and / or The flame retardant synergist is antimony trioxide.

10. The color-adjustable flame-retardant and antistatic polypropylene composition for pipes according to claim 1 or 2, wherein, The surface modifier is selected from titanate coupling agents and silane coupling agents; and / or The compatibilizer is a polar monomer-grafted polymer.

11. The color-adjustable flame-retardant and antistatic polypropylene composition for pipes according to claim 10, wherein, The polar monomer is selected from one or more of acid anhydrides, carboxylic acids, carboxylic acid derivatives, amino compounds, hydroxyl compounds, epoxy compounds, and ionic compounds.

12. The color-adjustable flame-retardant and antistatic polypropylene composition for pipes according to claim 10, wherein, The compatibilizer is maleic anhydride-grafted polypropylene or glycidyl methacrylate-grafted polypropylene.

13. The color-adjustable flame-retardant and antistatic polypropylene composition for pipes according to claim 10, wherein, The compatibilizer is a maleic anhydride-grafted propylene homopolymer.

14. The color-adjustable flame-retardant and antistatic polypropylene composition for pipes according to claim 12, wherein, The maleic anhydride-grafted polypropylene, measured according to ISO 1133 at 230°C and 2.16 kg load, has a melt flow rate of 10–400 g / 10 min; and / or The maleic anhydride grafting rate of the maleic anhydride-grafted polypropylene is 1-2%.

15. The color-adjustable flame-retardant and antistatic polypropylene composition for pipes according to claim 14, wherein, The maleic anhydride-grafted polypropylene, under conditions of 230°C and 2.16 kg load, exhibits a melt flow rate of 50–200 g / 10 min as measured according to ISO 1133; and / or The maleic anhydride grafting rate of the maleic anhydride-grafted polypropylene is 1.2-1.5%.

16. The color-adjustable flame-retardant and antistatic polypropylene composition for pipes according to claim 1 or 2, wherein, The other additives are selected from one or more of antioxidants, lubricants, anti-photoaging agents, heat stabilizers, and superdispersants.

17. The color-adjustable flame-retardant and antistatic polypropylene composition for pipes according to claim 1 or 2, wherein, The color-adjustable flame-retardant and antistatic polypropylene composition used in the pipeline exhibits a melt flow rate of 0.1–0.8 g / 10 min as measured according to ISO 1133 under conditions of 230°C and a load of 2.16 kg; and / or The surface resistivity of the color-adjustable flame-retardant and antistatic polypropylene composition used in the pipeline, measured according to Chinese Coal Mine Industry Standard MT 113-1995, is less than 3 × 10⁻⁶. 8 Ω; and / or The flame-retardant and antistatic polypropylene composition for the pipeline, which has adjustable color, has the following flame-retardant properties as measured according to the Chinese Coal Mine Industry Standard MT 113-1995: after removing the alcohol torch, the arithmetic mean of the flame burning of the specimen should not exceed 3 seconds, the arithmetic mean of the flameless burning of the specimen should not exceed 10 seconds, and the flame propagation length should not exceed 280 mm.

18. The color-adjustable flame-retardant and antistatic polypropylene composition for pipes according to claim 17, wherein, The color-adjustable flame-retardant and antistatic polypropylene composition for the pipeline has a melt flow rate of 0.3–0.7 g / 10 min as measured according to ISO 1133 under conditions of 230°C and 2.16 kg load.

19. A method for preparing a color-tunable flame-retardant and antistatic polypropylene composition for pipes according to any one of claims 1 to 18, comprising the following steps: (1) The second polypropylene, carbon nanotubes, surface modifier, compatibilizer, optional pigment and optional other additives are added to a mixer in sequence and mixed thoroughly, and then extruded to prepare granular additive packages. (2) Add the flame retardant to the mixer and mix thoroughly; (3) The first polypropylene is fed to the main feed loss weigher. The granulated additive package obtained in step (1) and the flame retardant obtained in step (2) are respectively transported to the side feed loss weigher through the vacuum feeding device. The materials are added by the main feeder and the forced side feeder of the extruder to prepare a color-adjustable flame retardant and antistatic polypropylene composition for pipelines.

20. The method for preparing a color-adjustable flame-retardant and antistatic polypropylene composition for pipes according to claim 19, wherein, In step (1), the mixing temperature of the mixer is 40–80°C, the mixing time is 3–5 minutes, the extrusion temperature of the extruder is 180–220°C, and the extruder speed is 300 rpm; and / or In step (2), the mixer rotates at 100 rpm and the mixing time is 3 to 5 minutes; In step (3), the extrusion temperature is 190-230℃, the extruder speed is 200rpm, and after cooling, it is cut into 2-5mm particles by a pelletizer.

21. A pipe made of a color-adjustable flame-retardant and antistatic polypropylene composition according to any one of claims 1 to 18.