Fluoride-free flame-retardant polyphenyl ether resin composition as well as preparation method and application thereof

Abstract

The invention relates to a fluoride-free flame-retardant polyphenyl ether resin composition as well as a preparation method and application thereof, and belongs to the technical field of high polymer materials. The resin composition comprises the following raw material components in parts by weight: 67-80 parts of polyphenyl ether resin; 3 to 10 parts of HIPS (High Impact Polystyrene) resin; 10 to 16 parts of a phosphate ester flame retardant; 3 to 8 parts of cross-linked styrene toughening master batch; 1-3 parts of an inorganic nano flame retardant; 0.2 to 0.5 part of an antioxidant; 0.1 to 0.5 part of a light stabilizer; and 0.5 to 1.0 part of a lubricant. Compared with the prior art, the fluoride-free flame-retardant polyphenyl ether resin composition disclosed by the invention solves the problems that the conventional flame-retardant polyphenyl ether resin needs an anti-dripping agent PTFE for synergistic flame retardance but cannot meet the PFAS prohibition, and the fluoride-free flame-retardant polyphenyl ether scheme adopting phosphonitrile for flame retardance needs high cost, and has a wide application prospect.

Description

A fluorine-free flame-retardant polyphenylene ether resin composition, its preparation method and application Technical Field

[0001] This invention relates to the field of polymer materials technology, and in particular to a fluorine-free flame-retardant polyphenylene ether resin composition, its preparation method, and its application. Background Technology

[0002] Polyphenylene oxide (PPO) is one of the five major engineering plastics. It has excellent mechanical properties such as high impact strength, good flame retardancy, good heat resistance, low water absorption, low dielectric constant and dimensional stability. It is widely used in electronic appliances, household appliances, electrical control equipment, new energy batteries, photovoltaic junction boxes and other fields.

[0003] PPO resin is a flame-retardant polymer material with poor processing flowability. Therefore, it is usually modified with phosphate ester flame retardants to meet fire safety requirements. Phosphate ester flame retardants, represented by bisphenol A bis(diphenyl phosphate) (BDP) and resorcinol bis(diphenyl phosphate) (RDP), not only have high flame retardant efficiency and good plasticizing effect, significantly improving the processing flowability of PPO, but also have low cost. However, it is precisely because of the plasticizing effect of phosphate ester flame retardants that their flame-retardant system is prone to dripping during combustion. Therefore, it is usually necessary to add ultra-high molecular weight polytetrafluoroethylene (PTFE) anti-dripping agents to synergistically retard the flame retardants with phosphate esters. For example, CN103232702A discloses a high CTI flame-retardant polyphenylene ether resin composition, which includes 0.1 to 1.5 parts of polytetrafluoroethylene to improve the CTI of the polyphenylene ether resin composition without impairing its mechanical properties.

[0004] However, with increasingly stringent environmental bans on perfluorinated and polyfluoroalkyl substances (PFAS), PTFE, an anti-dripping agent containing PFAS, will no longer be permitted. Therefore, to maintain the V-0 flame retardancy rating of fluorine-free flame-retardant PPO, it will be necessary to significantly increase the PPO content in the formulation while reducing the content of phosphate ester flame retardants. This will drastically worsen the processing fluidity of flame-retardant PPO, exacerbating its already poor processing performance. Using phosphazenes, which have relatively weak plasticizing effects, as flame retardants for fluorine-free flame-retardant PPO not only leads to a sharp increase in cost (its unit cost is more than five times that of BDP), but also further deteriorates the processing fluidity of the flame-retardant PPO resin.

[0005] Therefore, there is an urgent need to develop a new type of fluorine-free flame-retardant polyphenylene ether resin composition to meet the requirements of high flame retardancy, excellent processing fluidity, and low cost. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of existing fluorine-free flame-retardant polyphenylene ether resins, such as low flame retardant efficiency, poor processing fluidity, and high formulation design costs, and to provide a fluorine-free flame-retardant polyphenylene ether resin composition, its preparation method, and its application.

[0007] The objective of this invention can be achieved through the following technical solution: This invention provides a fluorine-free flame-retardant polyphenylene ether resin composition, wherein the resin composition comprises the following raw material components in parts by weight: 67-80 parts of polyphenylene ether resin; 3-10 parts of HIPS resin; 10-16 parts of phosphate ester flame retardant; 3-8 parts of cross-linked styrene toughening masterbatch; 1-3 parts of inorganic nano flame retardant; 0.2-0.5 parts of antioxidant; 0.1-0.5 parts of light stabilizer; and 0.5-1.0 parts of lubricant.

[0008] Furthermore, the intrinsic viscosity of the polyphenylene oxide resin (PPO) is 0.35-0.50 dL / g.

[0009] Furthermore, the HIPS resin is a high-impact polystyrene polymer with a melt index of 3-15 g / 10min at 200 °C and 5 kg load.

[0010] Furthermore, the phosphate ester flame retardant is any one or a combination of triphenyl phosphate (TPP), bisphenol A bis(diphenyl phosphate) (BDP), bisphenol A bis(diphenyl phosphate) (RDP), and hydroquinone bis(diphenyl phosphate) (PX220).

[0011] Furthermore, the cross-linked styrene-based toughening masterbatch is composed of the following raw material components in parts by weight, wherein the parts by weight of antioxidant and lubricant are not included in the corresponding parts of the resin composition.

[0012] 95-98 parts SBS elastomer; 1-3 parts crosslinking agent; 1-3 parts co-crosslinking agent; 0.2-0.5 parts antioxidant; 0.3-1.0 parts lubricant.

[0013] Furthermore, the butadiene block content of the SBS elastomer (styrene-butadiene-styrene block copolymer) ranges from 70% to 90%.

[0014] Furthermore, the crosslinking agent is any one or a combination of dicumyl peroxide (DCP), di-tert-butyl peroxide (DTBP), and 1,3-bis(tert-butylperoxyisopropyl)benzene (BIPB).

[0015] Furthermore, the crosslinking agent is any one or a combination of triallyl isocyanurate (TAIC), trimethylolpropane trimethacrylate (TMPTMA), and divinylbenzene (DVB).

[0016] Furthermore, the cross-linked styrene-based toughening masterbatch is prepared by the following method: SBS elastomer, cross-linking agent, co-cross-linking agent, antioxidant, and lubricant are mixed evenly according to the formula, and fed into a twin-screw extruder through a metering device. Under the conveying, shearing, and mixing of the screw, the material undergoes melting, homogenization, stretching, cooling, and pelletizing steps to obtain the cross-linked styrene-based toughening masterbatch.

[0017] Furthermore, the twin-screw extruder has a screw length-to-diameter ratio of 40-50, an extrusion temperature of 160-200 ℃, and a screw speed of 200-400 rpm.

[0018] Furthermore, the inorganic nano flame retardant is any one or a combination of nano-intercalated montmorillonite, fumed silica, nano-calcium carbonate, and carbon nanotubes.

[0019] Furthermore, the antioxidant is any one or a combination of CIBA Fine Chemicals' Irganox 1010, Irganox 1076, and Irganox 168.

[0020] Furthermore, the light stabilizer is any one or a combination of hydroxybenzotriazole, 2-hydroxybenzophenone, and salicylates.

[0021] Further, the lubricant is any one or a combination of ethylene bis-stearamide, pentaerythritol stearate, white oil, fatty acid amide, barium stearate, magnesium stearate, polyethylene wax or silicone oil, ethylene-vinyl acetate copolymer, and ethylene-acrylic acid copolymer.

[0022] The present invention also provides a method for preparing a fluorine-free flame-retardant polyphenylene ether resin composition, the preparation method comprising the following steps: weighing each raw material component in proportion and mixing them thoroughly, feeding them into a twin-screw extruder through a metering device, and under the conveying, shearing and mixing of the screw, the material undergoes melting, homogenization, stretching, cooling and pelletizing steps to obtain a fluorine-free flame-retardant polyphenylene ether resin composition.

[0023] Furthermore, the twin-screw extruder has a screw length-to-diameter ratio of 35-45, an extrusion temperature of 220-260 ℃, and a screw speed of 300-500 rpm.

[0024] This invention also provides the application of a fluorine-free flame-retardant polyphenylene ether resin composition in the preparation of new energy battery casings, cover plates, chargers, control boxes, and photovoltaic modules.

[0025] The key to preventing dripping during combustion in phosphate ester flame retardant systems to achieve a V-0 flame retardant rating lies in increasing the melt strength and charring ability of the system. There are generally two approaches to improving polymer melt strength: one is to increase the chain entanglement density of the polymer molecular chains or to form a cross-linked network structure; the other is to add nanofillers to form a network structure within the polymer melt. Based on this, this invention innovatively employs the synergistic use of cross-linked SBS toughening masterbatch and inorganic nano-flame retardants, significantly improving the melt strength and charring ability of the flame-retardant PPO system. This greatly enhances the synergistic flame retardant ability, enabling the successful preparation of a low-cost, fluorine-free flame-retardant polyphenylene ether resin composition with excellent processing fluidity.

[0026] Compared with the prior art, the present invention has the following technical advantages: (1) The present invention innovatively adopts cross-linked SBS toughening masterbatch and inorganic nano flame retardant in synergy, which increases the entanglement and cross-linking of molecular chains. The inorganic nano flame retardant can form a network structure in the polymer melt and also improve the char formation ability, which greatly improves the dripping phenomenon in the combustion process. Therefore, it can significantly improve the melt strength and char formation ability of the flame retardant PPO system, and improve the overall synergistic flame retardant ability, so as to take into account the product requirements such as excellent processing fluidity and low cost.

[0027] (2) This invention solves the problem that conventional flame-retardant polyphenylene ether resins require anti-dripping agent PTFE for synergistic flame retardancy but cannot meet the PFAS ban, as well as the problem that fluorine-free flame-retardant polyphenylene ether solutions with phosphazene flame retardancy require high costs. It can meet the requirements of high flame retardancy, excellent processing fluidity, low cost and other aspects.

[0028] (3) The flame-retardant polyphenylene ether resin prepared by the present invention can meet the new environmental protection flame-retardant standard of EU PFAS FREE, and can be widely used in new energy battery shells, covers, chargers, electrical control boxes, photovoltaics and other fields, with a very broad application prospect. Detailed Implementation

[0029] The present invention will now be described in detail with reference to specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0030] Unless otherwise specified, the reagents, methods, instruments, and equipment used in this invention are conventional in the art. Unless otherwise specified, the reagents and materials used in the following examples are all commercially available.

[0031] The components and their properties involved in the following examples and comparative examples are as follows: HIPS resin is HIPS622, melt index 5 g / 10min (200 ℃, 5 kg), Shanghai SECCO Petrochemical Co., Ltd.; PPO-1 resin is ZM040, viscosity 0.40 dL / g, Zhongmu Chemical; PPO-2 resin is ZM045, viscosity 0.45 dL / g, Zhongmu Chemical; SBS792, Yueyang Petrochemical; BDP, Zhejiang Wansheng; phosphazene, WSFR-5101, Zhejiang Wansheng; DCP, analytical grade, Sinopharm Group; BIPB, analytical grade, Sinopharm Group; TAIC, analytical grade, Sinopharm Group; TMPTMA, analytical grade, Sinopharm Group; nano-intercalated MMT, Closite 10A, BYK, Germany; fumed silica, M-5, Cabot, specific surface area 200 m². 2 / g; Antioxidant: Irganox B900, Ciba; Light stabilizer: UVP, Ciba; Hindered amine: 770, Ciba; Lubricant: Zinc stearate, Zhejiang Yazong.

[0032] The test methods for the following embodiments and comparative examples are as follows: the tensile strength test was conducted in accordance with ISO 527 standard, and the test speed was 50 mm / min.

[0033] The bending strength test was conducted according to ISO 178 standard at a test speed of 2 mm / min.

[0034] The flexural modulus was tested according to ISO 178 standard at a speed of 2 mm / min.

[0035] The notched impact strength test was conducted in accordance with ISO 179 standard.

[0036] The heat distortion temperature was tested according to ISO 75 standard, with a load of 1.80 MPa and a heating rate of 50 ℃ / h.

[0037] Melt flow index tests were conducted according to ISO 1133 standard, with a load of 5 kg and a test temperature of 280 ℃.

[0038] Flame retardancy testing was conducted in accordance with UL94 standards.

[0039] The cross-linked styrene toughening masterbatch used in the following examples and comparative examples is as follows: (1) Cross-linked styrene toughening masterbatch A, with the following composition: 96 parts of SBS792; 2 parts of DCP; 2 parts of TAIC; 0.3 parts of antioxidant B900; 0.5 parts of zinc stearate.

[0040] (2) Crosslinked styrene toughening masterbatch B, with the following composition: 97 parts SBS792; 1 part BIPB; 2 parts TAIC; 0.3 parts antioxidant B900; 0.5 parts zinc stearate.

[0041] (3) Crosslinked styrene toughening masterbatch C, with the following composition: 97 parts SBS792; 2 parts BIPB; 1 part TMPTMA; 0.3 parts antioxidant B900; 0.5 parts zinc stearate.

[0042] The specific preparation method of the above-mentioned cross-linked styrene toughening masterbatch is as follows: SBS elastomer, cross-linking agent, co-cross-linking agent, antioxidant, and lubricant are mixed in a high-speed mixer for 10 minutes according to the ratio, and then fed into a twin-screw extruder through a metering device. Under the conveying, shearing and mixing of the screw, the material is melted, homogenized, stretched, cooled and pelletized to obtain the cross-linked styrene toughening masterbatch.

[0043] The twin-screw extruder has a screw length-to-diameter ratio of 44 and is equipped with a temperature control device and a vacuum device. The extrusion temperature is 160-200℃ and the screw speed is 300 rpm.

[0044] Based on the successful preparation of the above-mentioned cross-linked styrene toughening masterbatch, the preparation methods of the polyphenylene ether resin compositions in Examples 1-5 and Comparative Examples 1-5 are as follows: HIPS resin, polyphenylene ether resin, phosphate ester flame retardant, cross-linked styrene toughening masterbatch, inorganic nano flame retardant, antioxidant, light stabilizer, and lubricant are thoroughly mixed in a high-speed mixer, and then fed into a twin-screw extruder through a metering device. Under the conveying, shearing, and mixing of the screw, the material is melted, homogenized, stretched, cooled, and pelletized to obtain a fluorine-free flame-retardant polyphenylene ether resin composition.

[0045] The twin-screw extruder has a screw length-to-diameter ratio of 40 and is equipped with a temperature control device and a vacuum device; the extrusion temperature is between 220-260℃ and the screw speed is about 400 rpm.

[0046] The specific component ratios and test performance of Examples 1-5 and Comparative Examples 1-5 are summarized in Table 1.

[0047] Table 1. Summary of component ratios and performance of Examples 1-5 and Comparative Examples 1-5 As can be seen from Examples 1-5 in Table 1, the present invention, by using cross-linked SBS toughening masterbatch and inorganic nano-flame retardant in synergy, can greatly improve the flame retardant efficiency. The prepared fluorine-free flame-retardant polyphenylene ether resin has excellent mechanical properties and processing fluidity (notched impact greater than 10 KJ / m). 2 It has a melt index greater than 25 g / 10min and a heat distortion temperature greater than 115 ℃, while also having a relatively low cost.

[0048] Comparative Examples 1-2 show that as the BDP content increased from 7 phr to 10 phr, the flame retardancy of the 1.6mm non-fluorinated flame-retardant polyphenylene ether resin also decreased from V-0 to V-1, and the processing flow properties were poor (melt index below 15 g / 10min).

[0049] Comparative Example 3 shows that although the phosphazene flame retardant system can also achieve the V-0 flame retardant rating without fluorine, it is expensive and the processing flow properties of the material are still poor (melt index is less than 15 g / 10min).

[0050] Comparative Examples 4-5 show that cross-linked SBS toughening masterbatch and inorganic nano flame retardant have a significant synergistic effect in flame retardancy. When used alone, the flame retardant efficiency decreases significantly, and only a flame retardant rating of V-1 can be achieved.

[0051] In summary, this invention innovatively employs cross-linked SBS toughening masterbatch and inorganic nano flame retardant synergistically, increasing the entanglement and cross-linking of molecular chains. The inorganic nano flame retardant can form a network structure in the polymer melt and also enhance char formation ability, greatly improving the dripping phenomenon during combustion. Therefore, it can significantly improve the melt strength and char formation ability of the flame-retardant PPO system, and improve the overall synergistic flame retardant ability, so as to take into account the product requirements such as excellent flame retardant performance, good processing fluidity, and low cost.

[0052] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A fluorine-free flame-retardant polyphenylene ether resin composition, characterized in that, The resin composition comprises the following raw material components in parts by weight: 67-80 parts of polyphenylene ether resin; 3-10 parts of HIPS resin; 10-16 parts of phosphate ester flame retardant; 3-8 parts of cross-linked styrene toughening masterbatch; 1-3 parts of inorganic nano flame retardant; 0.2-0.5 parts of antioxidant; 0.1-0.5 parts of light stabilizer; and 0.5-1.0 parts of lubricant.

2. The fluorine-free flame-retardant polyphenylene ether resin composition according to claim 1, characterized in that, The intrinsic viscosity of the polyphenylene ether resin is 0.35-0.50 dL / g; the melt index of the HIPS resin at 200 ℃ and 5 kg load is 3-15 g / 10min.

3. The fluorine-free flame-retardant polyphenylene ether resin composition according to claim 1, characterized in that, The phosphate ester flame retardant is any one or a combination of triphenyl phosphate, bisphenol A bis(diphenyl phosphate), bisphenol A bis(diphenyl phosphate), and hydroquinone bis(diphenyl phosphate).

4. The fluorine-free flame-retardant polyphenylene ether resin composition according to claim 1, characterized in that, The cross-linked styrene-based toughening masterbatch is composed of the following raw material components in parts by weight: 95-98 parts SBS elastomer; 1-3 parts cross-linking agent; 1-3 parts co-cross-linking agent; 0.2-0.5 parts antioxidant; and 0.3-1.0 parts lubricant.

5. The fluorine-free flame-retardant polyphenylene ether resin composition according to claim 4, characterized in that, The butadiene block content of the SBS elastomer ranges from 70% to 90%; the crosslinking agent is any one or a combination of dicumyl peroxide, di-tert-butyl peroxide, and 1,3-bis(tert-butylperoxyisopropyl)benzene; the co-crosslinking agent is any one or a combination of triallyl isocyanurate, trimethylolpropane trimethacrylate, and divinylbenzene.

6. The fluorine-free flame-retardant polyphenylene ether resin composition according to claim 4, characterized in that, The cross-linked styrene-based toughening masterbatch is prepared by the following method: SBS elastomer, cross-linking agent, co-cross-linking agent, antioxidant, and lubricant are mixed evenly according to the formula, and fed into a twin-screw extruder through a metering device. Under the conveying, shearing, and mixing of the screw, the material undergoes melting, homogenization, stretching, cooling, and pelletizing steps to obtain the cross-linked styrene-based toughening masterbatch. The twin-screw extruder has a screw length-to-diameter ratio of 40-50, an extrusion temperature of 160-200 ℃, and a screw speed of 200-400 rpm.

7. The fluorine-free flame-retardant polyphenylene ether resin composition according to claim 1, characterized in that, The inorganic nano flame retardant is any one or a combination of nano-intercalated montmorillonite, fumed silica, nano-calcium carbonate, and carbon nanotubes.

8. The fluorine-free flame-retardant polyphenylene ether resin composition according to claim 1, characterized in that, The antioxidant is any one or a combination of Irganox 1010, Irganox 1076, and Irganox 168; the light stabilizer is any one or a combination of hydroxybenzotriazole, 2-hydroxybenzophenone, and salicylates; the lubricant is any one or a combination of ethylene bis-stearamide, pentaerythritol stearate, white oil, fatty acid amide, barium stearate, magnesium stearate, polyethylene wax or silicone oil, ethylene-vinyl acetate copolymer, and ethylene-acrylic acid copolymer.

9. A method for preparing the fluorine-free flame-retardant polyphenylene ether resin composition according to any one of claims 1-8, characterized in that, The preparation method includes the following steps: weighing each raw material component according to the proportion and mixing them thoroughly, feeding them into a twin-screw extruder through a metering device, and under the conveying, shearing and mixing of the screw, the material undergoes melting, homogenization, stretching, cooling and pelletizing steps to obtain a fluorine-free flame-retardant polyphenylene ether resin composition; the twin-screw extruder has a screw length-to-diameter ratio of 35-45, an extrusion temperature of 220-260 ℃, and a screw speed of 300-500 rpm.

10. The application of the fluorine-free flame-retardant polyphenylene ether resin composition according to any one of claims 1-8 in the preparation of new energy battery casings, cover plates, chargers, control boxes, and photovoltaic modules.

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