Flame-retardant color master batch and preparation process thereof

Abstract

This invention discloses a flame-retardant masterbatch and its preparation process, belonging to the field of polymer materials technology. The flame-retardant masterbatch comprises the following raw materials in parts by weight: carrier resin: 65-90 parts, modified magnesium hydroxide: 25-45 parts, colorant: 15-45 parts, dispersant: 1-5 parts, and antioxidant: 0.05-1 part. The preparation steps are as follows: S1, Weigh the carrier resin, modified magnesium hydroxide, colorant, dispersant, and antioxidant according to their weight proportions and add them to a high-speed mixer for uniform mixing to obtain a mixture; S2, Transfer the mixture to a twin-screw extruder, and after melt mixing, extrusion granulation, and drying, obtain the flame-retardant masterbatch. The prepared flame-retardant masterbatch has excellent flame-retardant and mechanical properties, and is stable and durable. Furthermore, the raw materials for preparing the flame-retardant masterbatch are readily available, the processing is simple, and it can be widely promoted.

Description

Technical Field

[0001] This invention belongs to the field of polymer materials technology, specifically relating to a flame-retardant masterbatch and its preparation process. Background Technology

[0002] With the rapid development of modern society, plastic products are widely used in daily life and industrial production due to their lightweight, durability, good plasticity, and low cost. As one of the most important additives in the production of plastic products, color masterbatch has increasingly higher requirements for its performance. However, ordinary color masterbatch in plastic products often only provides rich colors and enhances the appearance of the products, with generally poor wear resistance and impact resistance, making it difficult to meet the current needs of plastic products for color masterbatch. The limited performance of color masterbatch directly affects the application areas of plastic products.

[0003] As is well known, plastic products are easily flammable in fires, and may even drip, causing the fire to spread. They also release toxic gases during combustion. Therefore, color masterbatches need to have flame-retardant properties to reduce the risk of fire spreading from plastic products. Chinese patent application CN102070817A discloses a color masterbatch for food packaging and its manufacturing method. This food packaging color masterbatch is acid and alkali resistant and includes the following components and their weight parts: 40-60 parts low-density polyethylene, 40-45 parts acid and alkali resistant pigment, 25-45 parts organic pigment, 1-5 parts zinc stearate, 16-20 parts aluminum-titanium composite coupling agent, 1-5 parts polyethylene wax, and 0-10 parts calcium carbonate. This color masterbatch has good dispersibility and surface gloss, certain acid and alkali resistance, and is not easily faded. However, its application is limited to thermoplastic products, the preparation process is relatively complex, and the product does not have flame-retardant or anti-aging properties. Chinese patent application CN115592839A discloses a preparation process for an environmentally friendly color masterbatch formulation, including the following steps: S1, raw material preparation; S2, color masterbatch production; S3, flame retardant layer coating; S4, antioxidant layer coating; S5, anti-agglomeration treatment; S6, storage environment. This invention relates to the preparation of flame-retardant environmentally friendly masterbatch, including first preparing a flame-retardant solution by mixing a flame retardant with half of a heat stabilizer and a dispersant, stirring the mixture in a mixer, removing the mixture, and then immersing the masterbatch carrier in the flame-retardant solution to obtain the flame-retardant environmentally friendly masterbatch. The flame retardant is a mixture of triphosphate, magnesium hydroxide, and aluminum hydroxide. The flame-retardant components of this invention are simple, resulting in limited flame-retardant and smoke-suppressing effects. Furthermore, it requires modification and protection through multiple steps such as antioxidant layer coating and anti-agglomeration treatment, making the process complex and costly.

[0004] Therefore, developing a color masterbatch with excellent flame retardant properties is a technical problem that urgently needs to be solved. Summary of the Invention

[0005] The purpose of this invention is to provide a flame-retardant masterbatch and its preparation process to solve the problem of poor flame-retardant performance of masterbatches in the prior art.

[0006] The objective of this invention can be achieved through the following technical solutions:

[0007] The first aspect of this invention provides a flame-retardant masterbatch, comprising the following raw materials in parts by weight:

[0008] Carrier resin: 65-90 parts;

[0009] Modified magnesium hydroxide: 25-45 parts;

[0010] Pigment: 15-45 parts;

[0011] Dispersant: 1-5 parts;

[0012] Antioxidant: 0.05-1 part.

[0013] In some possible implementations, the modified magnesium hydroxide is prepared by the following steps:

[0014] Hexagonal flake magnesium hydroxide was added to anhydrous ethanol and stirred until uniformly dispersed. Salicylic aldehyde and p-phenylenediamine were then added, and the mixture was refluxed at 80-85℃ for 2-3 hours. Subsequently, DOPO (9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide) was added, and stirring was continued for 10-12 hours. The mixture was then filtered, washed, and vacuum dried to obtain modified magnesium hydroxide. By using a chemical reaction between salicylic aldehyde, p-phenylenediamine, and DOPO to coat the surface of hexagonal flake magnesium hydroxide, an organic-inorganic magnesium hydroxide flame retardant was obtained. This significantly reduced the surface energy of the hexagonal flake magnesium hydroxide, preventing stacking and agglomeration, and improving the dispersibility and compatibility of magnesium hydroxide in the carrier resin.

[0015] In some possible implementations, the ratio of hexagonal flake magnesium hydroxide, anhydrous ethanol, salicylaldehyde, p-phenylenediamine, and DOPO is 1.0-1.5 g: 50 mL: 1.0-1.1 g: 0.40-0.42 g: 1.60-1.65 g.

[0016] In some possible implementations, the carrier resin is one of polyethylene resin, polycarbonate resin, and polypropylene resin.

[0017] In some possible implementations, the colorant includes at least one of cadmium red, cadmium yellow, cadmium orange, titanium dioxide, carbon black, iron oxide red, cobalt blue, and cobalt green.

[0018] In some possible implementations, the dispersant is at least one of paraffin wax, vinyl bis-stearamide (EBS), polyethylene wax, magnesium stearate, and calcium stearate.

[0019] In some possible implementations, the antioxidant is at least one of hindered phenolic antioxidants and phosphite antioxidants.

[0020] A second aspect of this invention provides a process for preparing flame-retardant masterbatch, comprising the following steps:

[0021] S1. Weigh out the carrier resin, modified magnesium hydroxide, colorant, dispersant and antioxidant according to the weight parts, add them to a high-speed mixer and mix evenly to obtain a mixture;

[0022] S2. The mixture is transferred to a twin-screw extruder, and after melt mixing, extrusion granulation and drying, flame-retardant masterbatch is obtained.

[0023] In some possible implementations, the speed of the high-speed mixer in S1 is 160-200 r / min, and the mixing time is 1-2 h.

[0024] In some possible implementations, the screw speed of the twin-screw extruder in S2 is 250-300 r / min, with the temperature in zone 1 being 140-160℃, zone 2 160-180℃, zone 3 190-210℃, zone 4 180-220℃, zone 5 190-210℃, and the die temperature being 160-180℃.

[0025] The beneficial effects of this invention are:

[0026] 1) This invention provides a flame-retardant masterbatch and its preparation process. The masterbatch is prepared by mixing a carrier resin, modified magnesium hydroxide, colorant, dispersant, and antioxidant, followed by melt blending in a granulator and extrusion granulation. The flame-retardant masterbatch prepared by this invention exhibits excellent flame-retardant and mechanical properties, and is stable and durable. Furthermore, the raw materials for preparing the flame-retardant masterbatch are readily available, the processing is simple, and it can be widely adopted.

[0027] 2) In this invention, modified magnesium hydroxide undergoes a Schiff base reaction with salicylaldehyde, p-phenylenediamine, and DOPD to form a compound containing phosphorus and nitrogen. The phenolic hydroxyl groups of salicylaldehyde then coat the surface of the hexagonal flake-like magnesium hydroxide through the interaction between the metal ions in the magnesium hydroxide, ultimately forming an organic-inorganic combined flame retardant. At this point, the modified magnesium hydroxide, acting as a flame retardant, interacts with the carrier resin to form a hard and dense char layer, improving the flame retardant performance of the masterbatch and also providing smoke suppression. Furthermore, the DOPO structure can combine with nitrogen-, sulfur-, or boron-containing compounds, utilizing the synergistic effect of the flame-retardant groups to form a heat-insulating, multi-dimensional, sparsely expanded char layer during combustion, acting as a barrier against air, heat, and pyrolysis products during thermal decomposition. Therefore, due to the double-layer barrier effect of the organic coke and metal protective layer, the synergistic effect of phosphorus and nitrogen, and the free radical quenching effect, the prepared masterbatch exhibits excellent thermal and flame-retardant properties. Meanwhile, magnesium hydroxide with a layered structure, which has self-lubricating properties, anisotropy, good thermal conductivity and mechanical strength, is used as a filler to significantly improve the mechanical strength and wear resistance of the carrier resin.

[0028] 3) The color masterbatch prepared by this invention has a tensile strength of over 36.5 MPa, an elongation at break of over 226%, an oxygen index of over 37%, and a smoke density of less than 63%. All masterbatches have a flame retardant rating of V-0 and an abrasion value of less than 0.15 g, exhibiting excellent flame retardant properties, good abrasion resistance, and excellent mechanical properties. Detailed Implementation

[0029] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0030] The hindered phenolic antioxidant used in the embodiments and comparative examples of this invention is antioxidant 1010, purchased from Shanghai Haohong Biomedical Technology Co., Ltd.; the MgCl2 used is purchased from China Western Mining Group and purified by recrystallization before use; the salicylaldehyde used is purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.; the polyethylene resin used is purchased from Shanghai Dingfen Chemical Technology Co., Ltd.; the cadmium red used is purchased from Jinan Longsheng Dyestuff Chemical Co., Ltd.; and the other reagents without specified manufacturers can be obtained through commercially available conventional products.

[0031] The hexagonal sheet-like magnesium hydroxide used in this invention is prepared through the following steps:

[0032] 2 mL of MgCl2 solution (1 mol / L) and 25 mL of NH3·H2O (10 mol / L) were mixed and stirred for 10 min. Then, 3 mL of sodium dodecyl sulfate was added, and the mixture was stirred for another 30 min. The mixture was then transferred to a tetrafluoroethylene-lined autoclave, sealed, and subjected to a hydrothermal reaction at 120 °C for 12 h. After the autoclave cooled to room temperature, the resulting white precipitate was collected, washed three times with distilled deionized water and anhydrous ethanol, and dried in a vacuum drying oven at 80 °C for 6 h to obtain hexagonal flake magnesium hydroxide.

[0033] Example 1

[0034] This embodiment provides a modified magnesium hydroxide, and the preparation steps are as follows:

[0035] 1.0 g of hexagonal flake magnesium hydroxide was added to 50 mL of anhydrous ethanol and stirred until evenly dispersed. 1.0 g of salicylaldehyde and 0.40 g of p-phenylenediamine were added, and the mixture was refluxed at 80 °C for 3 h. Then 1.60 g of DOPO was added, and the mixture was stirred for another 10 h. The mixture was filtered, washed three times with anhydrous ethanol and deionized water, and dried in a vacuum drying oven at 60 °C for 12 h to obtain modified magnesium hydroxide.

[0036] Example 2

[0037] This embodiment provides a modified magnesium hydroxide, and the preparation steps are as follows:

[0038] 1.45 g of hexagonal flake magnesium hydroxide was added to 50 mL of anhydrous ethanol and stirred until evenly dispersed. 1.1 g of salicylaldehyde and 0.41 g of p-phenylenediamine were added, and the mixture was refluxed at 80 °C for 3 h. Then 1.65 g of DOPO was added, and the mixture was stirred for another 10 h. The mixture was filtered, washed three times with anhydrous ethanol and deionized water, and dried in a vacuum drying oven at 60 °C for 12 h to obtain modified magnesium hydroxide.

[0039] Comparative Example 1

[0040] This comparative example provides a modified magnesium hydroxide, and the preparation steps are as follows:

[0041] 1.0 g of hexagonal flake magnesium hydroxide was added to 50 mL of anhydrous ethanol and stirred until evenly dispersed. 1.0 g of salicylaldehyde and 0.40 g of p-phenylenediamine were added, and the mixture was refluxed at 80 °C for 3 h. The mixture was stirred for another 10 h, filtered, and washed three times with anhydrous ethanol and deionized water, respectively. The mixture was then dried in a vacuum drying oven at 60 °C for 12 h to obtain modified magnesium hydroxide.

[0042] Comparative Example 2

[0043] This comparative example provides a modified magnesium hydroxide, and the preparation steps are as follows:

[0044] The modified magnesium hydroxide is the hexagonal flake magnesium hydroxide prepared in this invention.

[0045] Example 3

[0046] This embodiment provides a flame-retardant masterbatch, comprising the following raw materials in parts by weight:

[0047] Polyethylene resin: 65 parts, modified magnesium hydroxide from Example 1: 25 parts, cadmium red: 15 parts, paraffin: 2 parts, antioxidant 1010: 0.05 parts.

[0048] The preparation steps of the flame-retardant masterbatch are as follows:

[0049] S1. Weigh out the following by weight: polyethylene resin, modified magnesium hydroxide, cadmium red, paraffin wax and antioxidant 1010 from Example 1 and add them to a high-speed mixer for uniform mixing. The speed of the high-speed mixer is 160 r / min and the mixing time is 2 h to obtain the mixture.

[0050] S2. The mixture is transferred to a twin-screw extruder and melt-mixed. The screw speed of the twin-screw extruder is 250 r / min. The temperature of zone 1 is 140℃, zone 2 is 160℃, zone 3 is 190℃, zone 4 is 180℃, zone 5 is 190℃, and the die temperature is 160℃. After extrusion granulation and drying, flame-retardant masterbatch is obtained.

[0051] Example 4

[0052] The only difference compared to Example 3 is:

[0053] Replace 25 portions of the modified magnesium hydroxide in Example 1 with 25 portions of the modified magnesium hydroxide in Example 2.

[0054] Example 5

[0055] The only difference compared to Example 3 is:

[0056] Replace 25 portions of the modified magnesium hydroxide in Example 1 with 35 portions of the modified magnesium hydroxide in Example 1.

[0057] Example 6

[0058] The only difference compared to Example 3 is:

[0059] Replace 25 portions of the modified magnesium hydroxide in Example 1 with 45 portions of the modified magnesium hydroxide in Example 1.

[0060] Example 7

[0061] The only difference compared to Example 3 is:

[0062] Polyethylene resin: 75 parts, modified magnesium hydroxide from Example 1: 30 parts, cadmium red: 25 parts, paraffin: 3 parts, antioxidant 1010: 0.15 parts.

[0063] Example 8

[0064] The only difference compared to Example 3 is:

[0065] Polyethylene resin: 88 parts, modified magnesium hydroxide from Example 1: 42 parts, cadmium red: 40 parts, paraffin: 4 parts, antioxidant 1010: 0.85 parts.

[0066] Example 9

[0067] The only difference compared to Example 3 is:

[0068] The preparation steps of the flame-retardant masterbatch are as follows:

[0069] S1. Weigh out the polyethylene resin, modified magnesium hydroxide, cadmium red, paraffin and antioxidant 1010 according to the weight parts and add them to a high-speed mixer for uniform mixing. The speed of the high-speed mixer is 190 r / min and the mixing time is 1.5 h to obtain the mixture.

[0070] S2. The mixture is transferred to a twin-screw extruder and melt-mixed. The screw speed of the twin-screw extruder is 250 r / min. The temperature of zone 1 is 140℃, zone 2 is 160℃, zone 3 is 190℃, zone 4 is 180℃, zone 5 is 190℃, and the die temperature is 160℃. After extrusion granulation and drying, flame-retardant masterbatch is obtained.

[0071] Example 10

[0072] The only difference compared to Example 3 is:

[0073] The preparation steps of the flame-retardant masterbatch are as follows:

[0074] S1. Weigh out the following by weight: polyethylene resin, modified magnesium hydroxide, cadmium red, paraffin wax and antioxidant 1010 from Example 1 and add them to a high-speed mixer for uniform mixing. The speed of the high-speed mixer is 160 r / min and the mixing time is 2 h to obtain the mixture.

[0075] S2. The mixture is transferred to a twin-screw extruder and melt-mixed. The screw speed of the twin-screw extruder is 280 r / min. The temperature of zone 1 is 155℃, zone 2 is 170℃, zone 3 is 200℃, zone 4 is 210℃, zone 5 is 210℃, and the die temperature is 180℃. After extrusion granulation and drying, flame-retardant masterbatch is obtained.

[0076] Comparative Example 3

[0077] The only difference compared to Example 3 is:

[0078] Replace 25 portions of the modified magnesium hydroxide in Example 1 with 25 portions of the modified magnesium hydroxide in Comparative Example 1.

[0079] Comparative Example 4

[0080] The only difference compared to Example 3 is:

[0081] Replace 25 portions of the modified magnesium hydroxide in Example 1 with 25 portions of the modified magnesium hydroxide in Comparative Example 2.

[0082] Comparative Example 5

[0083] The only difference compared to Example 3 is:

[0084] Replace 25 portions of the modified magnesium hydroxide in Example 1 with 20 portions of the modified magnesium hydroxide in Example 1.

[0085] Comparative Example 6

[0086] The only difference compared to Example 3 is:

[0087] Replace 25 portions of the modified magnesium hydroxide from Example 1 with 55 portions of the modified magnesium hydroxide from Example 1.

[0088] Comparative Example 7

[0089] The only difference compared to Example 3 is:

[0090] Polyethylene resin: 55 parts, modified magnesium hydroxide from Example 1: 25 parts, cadmium red: 15 parts, paraffin: 2 parts, antioxidant 1010: 0.05 parts.

[0091] Comparative Example 8

[0092] The only difference compared to Example 3 is:

[0093] Polyethylene resin: 55 parts, modified magnesium hydroxide from Example 1: 20 parts, cadmium red: 15 parts, paraffin: 1 part, antioxidant 1010: 0.05 parts.

[0094] Comparative Example 9

[0095] The only difference compared to Example 3 is:

[0096] The preparation steps of the flame-retardant masterbatch are as follows:

[0097] S1. Weigh out the polyethylene resin, modified magnesium hydroxide, cadmium red, paraffin and antioxidant 1010 according to the weight parts and add them to a high-speed mixer for uniform mixing. The speed of the high-speed mixer is 140 r / min and the mixing time is 2 h to obtain the mixture.

[0098] Comparative Example 10

[0099] The only difference compared to Example 3 is:

[0100] The preparation steps of the flame-retardant masterbatch are as follows:

[0101] S2. The mixture is transferred to a twin-screw extruder and melt-mixed. The screw speed of the twin-screw extruder is 250 r / min. The temperature of zone 1 is 130℃, zone 2 is 150℃, zone 3 is 175℃, zone 4 is 170℃, zone 5 is 220℃, and the die temperature is 160℃. After extrusion granulation and drying, flame-retardant masterbatch is obtained.

[0102] The performance of the masterbatches obtained in Examples 3-10 and Comparative Examples 3-10 was tested:

[0103] 1) Tensile strength and elongation at break test: The tensile properties of the cable material are tested according to GB / T1040.3-2006 standard;

[0104] 2) Oxygen Index Test: The oxygen index of the cable material was determined by conducting a high-temperature test in accordance with GB / T 2406.3-2022 standard.

[0105] 3) Smoke density test: The smoke density of the electrical materials was tested according to the single-chamber method of GB / T8323.2-2008 standard.

[0106] 4) Flame retardant performance test: The flame retardant performance test shall be conducted in accordance with the vertical burning test specified in GB / T 2408-2021.

[0107] 5) Abrasion Resistance Test: The abrasion resistance of the samples was tested using a Taber abrasion tester. Two grinding wheels were placed on the sample, and the grinding wheel moving speed was set to 30 r / min to conduct the abrasion test. The initial mass of the sample and the mass of the sample after 2000 revolutions of wear were recorded. The formula for calculating the abrasion value of the sample is as follows:

[0108] Q = Mm;

[0109] In the formula, Q is the wear value of the sample, g / 2000r; M is the initial mass of the sample, g; and m is the mass of the sample after wear, g.

[0110] The results are shown in Table 1:

[0111] Table 1

[0112]

[0113]

[0114] As can be seen from Table 1, the mechanical properties and flame retardant properties of the color masterbatches prepared in Examples 3-10 are higher than those of Comparative Examples 3-10. Therefore, the color masterbatches provided by the present invention have excellent flame retardant properties, wear resistance and mechanical properties.

[0115] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0116] 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 flame-retardant masterbatch, characterized in that, Including the following parts by weight of raw materials: Carrier resin: 65 parts; Modified magnesium hydroxide: 35-45 parts; Pigment: 15 parts; Dispersant: 2 parts; Antioxidant: 0.05 parts; The modified magnesium hydroxide is prepared by the following steps: Hexagonal flake magnesium hydroxide was added to anhydrous ethanol and stirred until evenly dispersed. Salicylic aldehyde and p-phenylenediamine were added, and the mixture was refluxed at 80-85℃ for 2-3 hours. Then DOPO was added, and stirring was continued for 10-12 hours. The mixture was filtered, washed, and vacuum dried to obtain modified magnesium hydroxide. Modified magnesium hydroxide was formed by the Schiff base reaction of salicylic aldehyde, p-phenylenediamine, and DOPD, forming a compound containing phosphorus and nitrogen elements. The phenolic hydroxyl groups of salicylic aldehyde were coated on the surface of hexagonal flake magnesium hydroxide through the interaction between them and the metal ions in magnesium hydroxide, thus forming an organic-inorganic combined flame retardant. At this point, the modified magnesium hydroxide, as a flame retardant, interacted with the carrier resin to form a hard and dense char layer. The preparation process of the flame-retardant masterbatch includes the following steps: S1. Weigh out the carrier resin, modified magnesium hydroxide, colorant, dispersant and antioxidant by weight and add them to a high-speed mixer for uniform mixing. The speed of the high-speed mixer is 160-200 r / min and the mixing time is 1-2 h to obtain the mixture. S2. Transfer the mixture to a twin-screw extruder. The screw speed of the twin-screw extruder is 250-300 r / min. The temperature of zone 1 is 140-160℃, zone 2 is 160-180℃, zone 3 is 190-210℃, zone 4 is 180-220℃, zone 5 is 190-210℃, and the die temperature is 160-180℃. After melt mixing, extrusion granulation, and drying, flame-retardant masterbatch is obtained.

2. The flame-retardant masterbatch according to claim 1, characterized in that, The ratio of hexagonal flake magnesium hydroxide, anhydrous ethanol, salicylaldehyde, p-phenylenediamine, and DOPO is 1.0-1.5g: 50mL: 1.0-1.1g: 0.40-0.42g: 1.60-1.65g.

3. The flame-retardant masterbatch according to claim 1, characterized in that, The carrier resin is one of polyethylene resin, polycarbonate resin, and polypropylene resin.

4. The flame-retardant masterbatch according to claim 1, characterized in that, The colorant includes at least one of cadmium red, cadmium yellow, cadmium orange, titanium dioxide, carbon black, iron oxide red, cobalt blue, and cobalt green.

5. The flame-retardant masterbatch according to claim 1, characterized in that, The dispersant is at least one of paraffin wax, vinyl bis-stearamide, polyethylene wax, magnesium stearate, and calcium stearate.

6. The flame-retardant masterbatch according to claim 1, characterized in that, The antioxidant is at least one of hindered phenolic antioxidants and phosphite antioxidants.

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