Fluorine-free halogen-free flame-retardant polypropylene composition as well as preparation method and application thereof

Abstract

The invention provides a fluorine-free halogen-free flame-retardant polypropylene composition as well as a preparation method and application thereof. The fluorine-free halogen-free polypropylene composition comprises the following components in parts by weight: 55-70 parts of polypropylene resin; 24 to 30 parts of a compound flame retardant; 9 to 15 parts of SBS resin; 0.2-2 parts of an active auxiliary agent; wherein the melt flow rate of the SBS resin is greater than or equal to 4g / 10min at 190 DEG C under the load of 5kg; the compound flame retardant comprises a piperazine flame retardant, a melamine salt flame retardant and a phosphinic / phosphate flame retardant. The polypropylene composition prepared by adding the SBS resin with a specific melt flow rate and the active auxiliary agent into a polypropylene resin system and combining with the compound flame retardant is good in flame retardant property and better in mechanical property.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, and more specifically, to a fluorine-free and halogen-free flame-retardant polypropylene composition, its preparation method, and its application. Background Technology

[0002] Polypropylene (PP) resin, one of the five major general-purpose plastics, has advantages such as easy processing, good electrical insulation, and resistance to chemical solvents, and is widely used in automobiles, home appliances, wires and cables, packaging materials, and other fields. However, PP resin is very prone to oxidative degradation at high temperatures, and it is easy to drip while burning. Usually, fluorinated anti-dripping agents are added to solve the problem of flame retardant dripping. However, the REACH ban aims to prohibit the manufacture, placement on the market, and use of all perfluoroalkyl and polyfluoroalkyl compounds (PFAS) in the European Union.

[0003] Traditional halogen-free flame retardants, such as nitrogen-phosphorus and inorganic oxide flame retardants, have excellent flame retardant effects. However, to achieve V-0 flame retardancy without adding anti-dripping agents, it is generally necessary to appropriately increase the content of the flame retardant. However, due to the difference in compatibility between the flame retardant and the matrix resin, the mechanical properties of the material will be significantly reduced.

[0004] Prior art CN117730121A discloses a fluorine-free and halogen-free flame-retardant polypropylene, which is produced by adding high melt strength polypropylene (HMS) with a melt strength of at least 20 cN. PP is used as an anti-dripping agent, with high melt strength PP added at a level of over 10%, achieving V-0 flame retardancy in 1.6mm specimens and exhibiting similar mechanical properties to samples with added anti-dripping agents. However, due to the high melt strength content, the melt index of the system is relatively low, leading to difficulties in material processing. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art in which fluorine-free polypropylene compositions cannot simultaneously possess good flame retardant properties and mechanical properties, and to provide a fluorine-free and halogen-free flame-retardant polypropylene composition.

[0006] Another object of the present invention is to provide a method for preparing the above-mentioned fluorine-free and halogen-free flame-retardant polypropylene composition.

[0007] Another object of the present invention is to provide the application of the above-mentioned fluorine-free and halogen-free flame-retardant polypropylene combination.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] A fluorine-free and halogen-free flame retardant polypropylene composition comprising the following components in parts by weight: 55-70 parts of polypropylene resin; 24-30 parts of compound flame retardant; 9-15 parts of SBS resin; 0.2 to 2 parts of active additives; The SBS resin has a melt flow rate ≥4g / 10min at 190℃ and 5kg load; preferably, the SBS resin has a melt flow rate of 5~15g / 10min at 190℃ and 5kg load; the compounded flame retardant includes piperazine flame retardants, melamine salt flame retardants and phosphine / phosphate flame retardants.

[0010] This invention provides a fluorine-free and halogen-free flame-retardant polypropylene composition. Polypropylene resin is used as the matrix resin, and styrene-butadiene-styrene (SBS resin) with a specific melt flow rate is added to be uniformly dispersed in the system. At the same time, the SBS resin contains an active double bond structure, which can work together with active additives during combustion to connect the free radicals generated by the breakage of polypropylene resin. Combined with a compound flame retardant, the resulting polypropylene composition has good flame retardant properties and good mechanical properties.

[0011] It should be noted that the fluorine-free and halogen-free flame-retardant polypropylene composition described in this invention refers to a composition from flame-retardant additives where the fluorine content does not exceed 10 ppm, the total chlorine and bromine content does not exceed 1500 ppm, and the individual chlorine and bromine content does not exceed 900 ppm, achieving a flame retardancy of 1.5 mmV-0.

[0012] It should be noted that, in the fluorine-free and halogen-free flame-retardant polypropylene composition described in this invention, the polypropylene resin content is preferably not less than 50 wt%.

[0013] It should be noted that the active ingredient is 0.2 to 2 parts, for example, but not limited to 0.2 parts, 0.3 parts, 0.4 parts, 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts, 1 part, 1.1 parts, 1.2 parts, 1.3 parts, 1.4 parts, 1.5 parts, 1.6 parts, 1.7 parts, 1.8 parts, 1.9 parts, or 2 parts, etc., and the specific values ​​between the above values ​​are not exhaustively listed in this invention due to space limitations and for the sake of brevity.

[0014] Preferably, the active additives include acrylate polymers and / or epoxy resins.

[0015] More preferably, the active additives include acrylate polymers and epoxy resins.

[0016] More preferably, the mass ratio of acrylate polymer to epoxy resin in the active additive is 1:(0.3~3).

[0017] Preferably, the acrylate polymer includes one or more of pentaerythritol triacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, or glycerol trihydroxypropyl ether triacrylate.

[0018] Preferably, the epoxy resin includes one or more of bisphenol A type epoxy resin, bisphenol F type epoxy resin, polyphenol type glycidyl ether epoxy resin, aliphatic glycidyl ether epoxy resin, or aliphatic glycidyl ester epoxy resin.

[0019] Preferably, the number average molecular weight of the epoxy resin is 800-2000.

[0020] It should be noted that the SBS resin is 9 to 15 parts, for example, but not limited to 9 parts, 9.5 parts, 10 parts, 10.5 parts, 11 parts, 11.5 parts, 12 parts, 12.5 parts, 13 parts, 13.5 parts, 14 parts, 14.5 parts, or 15 parts, etc., and the specific values ​​between the above values ​​are not exhaustively listed in this invention due to space limitations and for the sake of brevity.

[0021] Preferably, in the fluorine-free and halogen-free polypropylene composition of the present invention, the content of SBS resin is 8wt% to 15wt%.

[0022] It should be noted that the SBS resin described in this invention has a melt flow rate of ≥4 g / 10 min at 190°C and a load of 5 kg, for example, but not limited to ≥4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10, 10.5, 11, 11.5, 12, 12.5, 13, 13.5, 14, 14.5, or 15 g / 10 min, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, the specific values ​​included in the range are not exhaustively listed in this invention.

[0023] Preferably, the SBS resin has a melt flow rate of 5~15g / 10min at 190℃ and 5kg load.

[0024] More preferably, the SBS resin has a melt flow rate of 6~10g / 10min at 190°C and a load of 5kg.

[0025] Specifically, the melt flow rate of the SBS resin is tested according to ASTM D1238:2023.

[0026] Preferably, the content of SBS resin in the fluorine-free and halogen-free flame-retardant polypropylene composition is 8-15 wt%.

[0027] It should be noted that the compound flame retardant is 24 to 28 parts, for example, but not limited to 24 parts, 24.5 parts, 25 parts, 25.5 parts, 26 parts, 26.5 parts, 27 parts, 27.5 parts, or 28 parts, etc., and the specific values ​​between the above values ​​are not exhaustively listed in this invention due to space limitations and for the sake of brevity.

[0028] Preferably, the piperazine flame retardant includes one or more of piperazine phosphate, piperazine pyrophosphate, or piperazine polyphosphate.

[0029] Preferably, the melamine salt flame retardant includes melamine pyrophosphate flame retardant and / or melamine polyphosphate flame retardant.

[0030] Preferably, the phosphine / phosphate flame retardant includes one or more of aluminum hypophosphite, calcium hypophosphite, or aluminum diethylphosphite.

[0031] Preferably, the melt flow rate of the polypropylene resin at 230°C and a load of 2.16 kg is ≥28 g / 10 min.

[0032] More preferably, the melt flow rate of the polypropylene resin at 230°C and 2.16 kg load is 30~70 g / 10 min.

[0033] Specifically, the test standard for the melt flow rate is GB / T 3682.1-2018.

[0034] Preferably, the polypropylene resin comprises homopolymer polypropylene and / or copolymer polypropylene.

[0035] Without affecting the flame retardant and mechanical properties of the fluorine-free and halogen-free flame retardant polypropylene composition of the present invention, the fluorine-free and halogen-free flame retardant polypropylene composition further includes 0.5 to 2 parts of processing aids.

[0036] Specifically, the processing aids include, but are not limited to, one or more of antioxidants, lubricants, or colorants.

[0037] The antioxidants described in this invention can be commonly used antioxidants, such as, but not limited to, hindered phenolic antioxidants and / or phosphite antioxidants.

[0038] Specifically, the hindered phenolic antioxidant is one or more of N,N'-hexamethylene bis(3,5-di-tert-butyl-4-hydroxyphenylpropionamide) (Irganox 1098), pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (Irganox 1010), 1,6-hexanediol bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (Irganox 259), octadecyl β-(4-hydroxy-3,5-di-tert-butylphenyl)propionate (Irganox 1076), or 3,9-bis{2-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)acrylic acid]-1,1-dimethyl}-2,4,8,10-tetraoxaspirocycloundecane (ADK AO-80).

[0039] The phosphite antioxidant is one or more of tris(2,4-di-tert-butylphenyl) phosphite (Irganox 168), bis(2,6-di-tert-butyl-4-tolyl) pentaerythritol phosphite (PEP-36), or 627A.

[0040] The lubricant described in this invention can be a commonly used lubricant, such as, but not limited to, one or more of zinc stearate, calcium stearate, ester lubricants, or amide lubricants.

[0041] The color powder described in this invention can be selected from, for example but not limited to, carbon black, zinc sulfide, and other organic and inorganic color powders used for dyeing.

[0042] The present invention also provides a method for preparing the above-mentioned fluorine-free and halogen-free flame-retardant polypropylene composition, comprising the following steps: The components are mixed evenly in proportion, and then melt-extruded and granulated to obtain a fluorine-free and halogen-free flame-retardant polypropylene composition.

[0043] Specifically, the melt extrusion is performed using a screw extruder.

[0044] Specifically, the temperature of the first zone of the screw extruder is 110~130℃, and the temperature of the second to tenth zones is 200~220℃; the screw speed of the screw extruder is 400~500rpm; and the length-to-diameter ratio of the screw of the screw extruder is (38~42):1.

[0045] This invention also protects the application of the above-mentioned fluorine-free and halogen-free flame-retardant polypropylene composition in the preparation of housing materials for household appliances, especially for components that require both good flame retardant properties and mechanical properties.

[0046] A component made from the above-mentioned fluorine-free and halogen-free flame-retardant polypropylene composition, such as the outer casing of household appliances like televisions, power boxes, chargers, electric kettles, coffee makers, rice cookers, and microwave ovens.

[0047] Compared with the prior art, the beneficial effects of the present invention are: This invention provides a fluorine-free and halogen-free flame-retardant polypropylene composition. By adding SBS resin with a specific melt flow rate to polypropylene resin, and combining it with active additives and compounded flame retardants, the resulting polypropylene composition can have good mechanical properties and flame retardant properties, while also exhibiting good processability. Detailed Implementation

[0048] The technical solutions in the embodiments of the present invention will be clearly and completely described below, but the implementation of the present invention is not limited thereto.

[0049] Unless otherwise specified, the reagents, methods and equipment used in this invention are all conventional reagents, methods and equipment in this technical field.

[0050] 1. The raw materials used in the following examples and comparative examples are as follows: Polypropylene resin: Polypropylene resin 1: PP 7935E1, with a melt flow rate of 60 g / 10 min at 230°C and a load of 2.16 kg, was purchased from ExxonMobil. Polypropylene resin 2: PP 8285E, with a melt flow rate of 30 g / 10 min at 230°C and a load of 2.16 kg, was purchased from ExxonMobil; SBS resin: SBS resin 1: SBS 3546, with a melt flow rate of 6 g / 10 min at 190℃ and 5 kg load, was purchased from Lee Chang Yung Chemical Industry Co., Ltd. SBS resin 2: SBS 4202, with a melt flow rate of 7.5 g / 10 min at 190°C and 5 kg load, was purchased from TSRC Corporation. SBS resin 3: SBS 4265, with a melt flow rate of 10 g / 10 min at 190°C and 5 kg load, was purchased from TSRC Corporation. SBS resin 4: SBS KTR-401, melt flow rate <1g / 10min at 190℃ and 5kg load, purchased from Kumho Petrochemical Co., Ltd. SEBS resin: G1657, melt flow rate of 22 g / 10 min at 230℃ and 5 kg load, purchased from Kraton, USA; Active additives: Active ingredient 1: Trimethylolpropane trimethacrylate, purchased from Hefei Anbang Chemical Co., Ltd.; Active additive 2: Pentaerythritol triacrylate, purchased from Suzhou Senfida Chemical Co., Ltd.; Active additive 3: Bisphenol A type epoxy resin, KD-213, purchased from Guodu Chemical Co., Ltd.; Piperazine flame retardant: piperazine pyrophosphate, P190, purchased from Hunan Meilaipo Technology Development Co., Ltd.; Melamine flame retardant: melamine polyphosphate, MPP, purchased from Zhenjiang Xingxing Flame Retardant Co., Ltd.; Phosphine / phosphate flame retardant: aluminum diethylphosphinate, BEP-22E, purchased from Zhuhai Wantong; Compound flame retardant 1: A compound of piperazine flame retardant, melamine flame retardant and phosphine / phosphate flame retardant in a mass ratio of 1.5:1:0.3; Compound flame retardant 2: A compound of piperazine flame retardant, melamine flame retardant and phosphine / phosphate flame retardant in a mass ratio of 2:1:0.6; Compound flame retardant 3: A compound of melamine flame retardant and phosphine / phosphate flame retardant in a mass ratio of 1:0.3; Compound flame retardant 4: A compound of piperazine flame retardant and phosphine / phosphate flame retardant in a mass ratio of 1.5:0.3; Compound flame retardant 5: A compound of piperazine flame retardant and melamine flame retardant in a mass ratio of 2:1; Processing aids: Antioxidants: A compound of antioxidant 1010 and antioxidant 168 in a 1:1 mass ratio, both of which are commercially available; Lubricant: Calcium stearate, commercially available; It should be noted that the same raw materials were used in the parallel experiments of each embodiment and comparative example.

[0051] 2. The polypropylene compositions described in the examples and comparative examples were prepared according to the formulations in Tables 1-2 by the following preparation methods: The components are mixed evenly in proportion and added to a screw extruder for melt extrusion and granulation to obtain a polypropylene composition. The temperature of the first zone of the screw extruder is 120°C, and the temperature of the second to tenth zones is 210°C. The screw speed of the screw extruder is 450 rpm, and the length-to-diameter ratio of the screw extruder is 40:1.

[0052] 3. Performance Testing (1) Flame retardant performance test: The polypropylene compositions prepared in each example and comparative example were injection molded into flame retardant strips of 125mm×13mm×1.5mm and the flame retardant performance was tested according to UL94-2018. (2) Impact performance test: The polypropylene compositions prepared in each example and comparative example were injection molded into 80mm×10mm×4mm notched impact test specimens, and the impact test was carried out in accordance with GB / T 1843-2008. The notch type was V notch. (3) Melt flow rate test: The melt flow rate of the polypropylene compositions prepared in each example and comparative example was determined according to GB / T3682.1-2018 at 230°C and 2.16kg load.

[0053] (4) Tensile strength test: The polypropylene compositions prepared in each example and comparative example were tested according to GB / T 1040.2-2022, with a tensile rate of 50 mm / min.

[0054] Examples 1-10 and Comparative Examples 1-8 Table 1. Formulations (parts by weight) and properties of the polypropylene compositions in Examples 1-10

[0055] Table 2 Formulations (parts by weight) and properties of polypropylene compositions in Comparative Examples 1-8

[0056] As can be seen from Table 1, the fluorine-free and halogen-free flame-retardant polypropylene compositions prepared by this invention have good flame-retardant and mechanical properties. Specifically, they all meet the 1.5mm V-0 flame retardancy requirement, have tensile strengths ≥16MPa, and impact strengths ≥6KJ / m. 2 .

[0057] As can be seen from Comparative Examples 1 and 2, if the melt flow rate of the SBS resin used is too low or other resins are used instead of the SBS resin in this invention, the flame retardant properties of the resulting polypropylene composition will decrease significantly.

[0058] As can be seen from Comparative Examples 3-5 and 8, if specific compounded flame retardants are not used or processing aids are not added, the flame retardancy rating of the prepared polypropylene composition is significantly reduced and cannot meet the application requirements.

[0059] As can be seen from Comparative Example 6, if the amount of SBS resin added is too small, the flame retardant properties of the resulting polypropylene composition decrease, as do its impact properties.

[0060] As can be seen from Comparative Example 7, if too much SBS resin is added, the flame retardant properties of the resulting polypropylene composition decrease.

[0061] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A fluorine-free and halogen-free flame-retardant polypropylene composition, characterized in that, Includes the following components, calculated in parts by weight: 55-70 parts of polypropylene resin; 24-30 parts of compound flame retardant; 9-15 parts of SBS resin; 0.2 to 2 parts of active additives; The SBS resin has a melt flow rate ≥4g / 10min at 190℃ and 5kg load; preferably, the SBS resin has a melt flow rate of 5~15g / 10min at 190℃ and 5kg load; the compounded flame retardant includes piperazine flame retardants, melamine salt flame retardants and phosphine / phosphate flame retardants.

2. The fluorine-free and halogen-free flame-retardant polypropylene composition according to claim 1, characterized in that, The active additives include acrylate polymers and / or epoxy resins; preferably, the active additives include acrylate polymers and epoxy resins.

3. The fluorine-free and halogen-free flame-retardant polypropylene composition according to claim 2, characterized in that, Satisfy at least one of the following four conditions: (a) The mass ratio of acrylate polymer to epoxy resin in the active additive is 1:(0.3~3); (b) The acrylate polymers include one or more of pentaerythritol triacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate or glycerol trihydroxypropyl ether triacrylate; (c) The epoxy resin includes one or more of bisphenol A type epoxy resin, bisphenol F type epoxy resin, polyphenol type glycidyl ether epoxy resin, aliphatic glycidyl ether epoxy resin or aliphatic glycidyl ester epoxy resin. (d) The number average molecular weight of the epoxy resin is 800~2000.

4. The fluorine-free and halogen-free flame-retardant polypropylene composition according to claim 1, characterized in that, The mass ratio of piperazine flame retardant, melamine salt flame retardant and phosphine / phosphate flame retardant in the compound flame retardant is (1.4~2.2):1:(0.3~0.6).

5. The fluorine-free and halogen-free flame-retardant polypropylene composition according to claim 1 or 4, characterized in that, The piperazine flame retardant includes one or more of piperazine phosphate, piperazine pyrophosphate, or piperazine polyphosphate; the melamine salt flame retardant includes melamine pyrophosphate flame retardant and / or melamine polyphosphate flame retardant; the phosphine / phosphate flame retardant includes one or more of aluminum hypophosphite, calcium hypophosphite, or aluminum diethylphosphite.

6. The fluorine-free and halogen-free flame-retardant polypropylene composition according to claim 1, characterized in that, The polypropylene resin has a melt flow rate of ≥28g / 10min at 230℃ and 2.16kg load.

7. The fluorine-free and halogen-free flame-retardant polypropylene composition according to claim 1, characterized in that, It also includes 0.5 to 2 parts of processing aids; the processing aids include one or more of antioxidants, lubricants or colorants.

8. A method for preparing the fluorine-free and halogen-free flame-retardant polypropylene composition according to any one of claims 1 to 7, characterized in that, Includes the following steps: The components are mixed evenly in proportion, and then melt-extruded and granulated to obtain a fluorine-free and halogen-free flame-retardant polypropylene composition.

9. The use of the fluorine-free and halogen-free flame-retardant polypropylene composition according to any one of claims 1 to 7 in the preparation of housing materials for household appliances.

10. A component, characterized in that, It is prepared using the polypropylene composition according to any one of claims 1 to 7.

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