Flame-retardant reinforced polyphenyl ether composition with good appearance and low warpage and preparation method of flame-retardant reinforced polyphenyl ether composition

Abstract

The invention discloses a flame-retardant reinforced polyphenyl ether composition with good appearance and low warpage. The flame-retardant reinforced polyphenyl ether composition is prepared from the following components in parts by weight: 20-50 parts of homopolymerized PPO resin, 20-50 parts of copolymerized PPO resin, 20-40 parts of PS resin, 20-30 parts of reinforced fibers, 10-25 parts of a flame retardant and 0.1-0.3 part of an antioxidant. Wherein the copolymerized PPO resin is obtained by copolymerizing two or more monomers of dimethylphenol and dihydric alcohol, and is terminated by an end-capping reagent. The good-appearance low-warpage flame-retardant reinforced composition provided by the invention has good appearance and good processability, ensures that the resin and the reinforced fibers are fully combined, ensures that the reinforced fibers are not exposed under high-temperature and high-humidity conditions, plays a role in structural reinforcement, and meets the dimensional stability and strength stability of battery components.

Description

Technical Field

[0001] The invention relates to the technical field of polymer materials, in particular to a flame retardant reinforced polyphenylene ether composition with good appearance and low warpage and a preparation method thereof. Background Art

[0002] Polyphenylene ether (PPO or PPE), chemical name is poly 2,6-dimethyl-1,4-phenylene ether, also known as polyphenylene oxide or polyphenylene ether. PPO is an engineering plastic containing benzene rings in the main chain, so it has excellent mechanical strength, stress relaxation resistance, creep resistance, heat resistance, water resistance, water vapor resistance, dimensional stability, but pure PPO resin has poor impact toughness, high melt viscosity, poor processability, usually modified by alloying.

[0003] With the development of new energy, lithium batteries have also flourished. The safety of battery packs has received more attention from the public, and electric vehicle spontaneous combustion often appears in the public eye. The complex structure of battery brackets, the flame retardant effect of battery packs, the structural integrity retention rate after combustion, and the structural strength after ablation have appeared many times in the battery pack component test items of OEMs.

[0004] PPO material is an ideal material for lithium battery bracket battery packs due to its outstanding resistance to electrolyte, acid and alkali. However, due to the characteristics of PPO's chemical structure, it also has problems such as poor processability and fluidity, making it difficult to process complex structures. Reinforced PPO materials have poor compatibility with reinforcing fillers and poor appearance of injection molded parts due to factors such as poor fluidity of PPO resin, large steric hindrance caused by the presence of side methyl groups, and a small molecular weight range. Summary of the invention

[0005] In view of this, the present invention provides a flame retardant reinforced polyphenylene ether composition with good appearance and low warpage and a preparation method thereof, so as to solve the problems raised in the above-mentioned background technology, by adding copolymerized PPO resin into the PPO resin system, introducing a fat segment, reducing the internal application of injection molding, enhancing the wrapping property of the system on the reinforcing fiber, and improving the appearance of the material.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] In one aspect of the present invention, a flame retardant reinforced polyphenylene ether composition with good appearance and low warpage is prepared from the following components in parts by weight:

[0008]

[0009] The copolymerized PPO resin is obtained by copolymerizing dimethylphenol and diol and is capped by a capping agent.

[0010] As a further embodiment of the present invention: the dimethylphenol is 2,6-dimethylphenol, 2,5-dimethylphenol or 2,3-dimethylphenol; and / or the number of carbon atoms in the diol is four to six.

[0011] As a further solution of the present invention: the number average molecular weight of the homopolymer PPO resin is 2000-60000.

[0012] As a further solution of the present invention: the PS resin is at least one of polystyrene, high impact polystyrene, and syndiotactic polystyrene, and has a number average molecular weight of 80,000-120,000.

[0013] As a further solution of the present invention: the flame retardant is at least one of red phosphorus, cyclic phosphate, helical phosphate, triphenyl phosphate, bisphenol A bis(diphenyl phosphate), and resorcinol (diphenyl phosphate).

[0014] As a further solution of the present invention: the preparation method of the copolymerized PPO resin is:

[0015] At least two monomers are added to a toluene solution, and a catalyst is added, and a polymerization reaction is carried out at a temperature range of 20-50° C. After the reaction is carried out for 0.5-2 hours, a capping agent and methanol are added in sequence to obtain a copolymerized PPO resin.

[0016] As a further solution of the present invention: the reinforcing fiber is at least one of glass fiber powder, carbon fiber powder and basalt fiber powder, and its length is 200-800 μm.

[0017] As a further solution of the present invention: the antioxidant is at least one of hindered phenols, hindered amines, thioesters, and phosphites.

[0018] On the other hand, the present invention discloses a method for preparing the above-mentioned flame retardant reinforced polyphenylene ether composition with good appearance and low warpage, comprising the following steps:

[0019] Weigh each component according to weight, and mix all components except the reinforcing fiber uniformly to obtain a mixed material;

[0020] The mixed material is added from the main feeding port of the twin-screw extruder, and the reinforcing fiber is added from the side feeding port of the twin-screw extruder. After melting, extrusion and granulation, a flame-retardant reinforced polyphenylene ether composition with good appearance and low warpage is obtained.

[0021] As a further solution of the present invention: the operating parameters of the twin-screw extruder are: zone one temperature 180-230°C, zone two temperature 250-270°C, zone three temperature 250-275°C, zone four temperature 250-270°C, zone five temperature 260-270°C, zone six temperature 230-240°C, zone seven temperature 230-240°C, die head temperature 240-250°C, and the main screw speed is 300-500r / min.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] The good-appearance low-warpage flame-retardant reinforced composition provided by the present invention has good appearance and good processability, ensures full combination of resin and reinforcing fiber, ensures that the reinforcing fiber is not exposed under high temperature and high humidity conditions, plays a structural reinforcement role, and meets the dimensional stability and strength stability of battery components.

[0024] The details are as follows:

[0025] 1. The present invention obtains copolymerized PPO resin by introducing synthetic PPO comonomers and studying the polymerization process. The introduction of copolymerized PPO overcomes the difficult processing characteristics of PPO resin itself, introduces aliphatic chain segments, increases the range of activity of the molecular chain, reduces the internal application of injection molding, strengthens the wrapping of the resin on the reinforcing fiber, and the high flow components float on the surface preferentially during the injection molding process, achieving the effect of good appearance.

[0026] 2. The present invention reduces the length of the reinforcing fibers, thereby eliminating the orientation distribution of the reinforcing fiber size, improving the flatness of the large-area injection molding surface, and also having a positive effect on the appearance. DETAILED DESCRIPTION

[0027] For ease of understanding of the present invention, the present invention will be described more fully below in conjunction with specific embodiments. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thoroughly understood.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0029] The specific information of the raw materials used in the following examples and comparative examples is as follows:

[0030] Homopolymer PPO resin, the manufacturer is Nantong Xingchen Synthetic Materials Co., Ltd.;

[0031] PS resin, manufactured by Taiwan Chi Mei Co., Ltd.

[0032] Reinforced fiber, glass fiber powder is selected, the manufacturer is Jushi Group;

[0033] Flame retardant, spiral phosphate ester is selected, the manufacturer is Zhejiang Wansheng Co., Ltd.;

[0034] Antioxidants: Hindered phenol antioxidants, manufactured by BASF; Thioester antioxidants, manufactured by BASF; Phosphite antioxidants, manufactured by BASF;

[0035] All materials are commercially available common products.

[0036] It is to be understood that the above raw materials and reagents are only examples of some specific embodiments of the present invention, so that the technical solution of the present invention is clearer, and it does not mean that the present invention can only use the above reagents, and the specific scope in the claims shall prevail. In addition, the "parts" described in the examples and comparative examples, unless otherwise specified, refer to parts by weight.

[0037] Any range described in the present invention includes the end value and any numerical value between the end values ​​and any sub-range formed by the end value or any numerical value between the end values.

[0038] The following Table 1 shows the dosage of each component in the examples and comparative examples.

[0039] Table 1

[0040] Components Homopolymer PPO resin PS resin Flame retardants Copolymer PPO resin Reinforcement Fiber Antioxidants Example 1 20 20 10 20 10 0.1 Example 2 20 30 13 30 25 0.2 Example 3 30 40 16 40 30 0.3 Example 4 30 30 19 30 30 0.2 Example 5 50 30 25 20 30 0.2 Comparative Example 1 30 30 16 / 30 0.2 Comparative Example 2 30 30 16 30 30 0.2 Comparative Example 3 30 30 16 30 30 0.3

[0041] Example 1

[0042] In this embodiment, the number average molecular weight of the homopolymer PPO resin is 40,000, the number average molecular weight of the PS resin is 80,000, the flame retardant is a helical phosphate, the copolymer PPO resin is a polymerization monomer solution obtained by mixing 2,6-dimethylphenol and propylene glycol in a ratio of 9:1, and polymerizing for 0.5 h with acetic anhydride as a capping agent, the reinforcing fiber is 200 μm glass fiber powder, and the antioxidant is a hindered phenol antioxidant.

[0043] According to the weight proportions in Table 1, homopolymer PPO resin, PS resin, flame retardant, copolymer PPO resin and antioxidant are uniformly mixed, and the uniformly mixed materials are added to the main feed of the twin-screw extruder, and the glass fiber powder is added to the side feed of the twin-screw extruder, and melt extrusion granulation is performed to obtain a flame retardant reinforced polyphenylene ether composition with good appearance and low warpage. The working parameters of the twin-screw extruder are: the temperature of the first zone is 180°C, the temperature of the second zone is 250°C, the temperature of the third zone is 250°C, the temperature of the fourth zone is 250°C, the temperature of the fifth zone is 260°C, the temperature of the sixth zone is 230°C, the temperature of the seventh zone is 230°C, the temperature of the die head is 240°C, and the main screw speed is 300r / min.

[0044] Example 2

[0045] In this embodiment, the number average molecular weight of the homopolymer PPO resin is 50,000, the number average molecular weight of the PS resin is 80,000, the flame retardant is a helical phosphate, the copolymer PPO resin is a polymerization monomer solution obtained by mixing 2,6-dimethylphenol and propylene glycol in a ratio of 8:2, and polymerizing with acetic anhydride as a capping agent for 1 hour, the reinforcing fiber is 400 μm glass fiber powder, and the antioxidant is a hindered amine antioxidant.

[0046] According to the weight proportions in Table 1, homopolymer PPO resin, PS resin, flame retardant, copolymer PPO resin and antioxidant are uniformly mixed, and the uniformly mixed materials are added to the main feed of the twin-screw extruder, and the glass fiber powder is added to the side feed of the twin-screw extruder, and melt extrusion granulation is performed to obtain a flame retardant reinforced polyphenylene ether composition with good appearance and low warpage. The working parameters of the twin-screw extruder are: the temperature of the first zone is 190°C, the temperature of the second zone is 260°C, the temperature of the third zone is 260°C, the temperature of the fourth zone is 260°C, the temperature of the fifth zone is 270°C, the temperature of the sixth zone is 240°C, the temperature of the seventh zone is 240°C, the temperature of the die head is 250°C, and the main screw speed is 400r / min.

[0047] Example 3

[0048] In this embodiment, the number average molecular weight of the homopolymer PPO resin is 60,000, the number average molecular weight of the PS resin is 80,000, the flame retardant is a helical phosphate, the copolymer PPO resin is 2,5-dimethylphenol and 1,4-butanediol mixed in a ratio of 9:1 to form a polymerization monomer solution, which is obtained after polymerization for 1 hour with acetic anhydride as a capping agent, the reinforcing fiber is 600 μm glass fiber powder, and the antioxidant is a thioester antioxidant.

[0049] According to the weight proportions in Table 1, homopolymer PPO resin, PS resin, flame retardant, copolymer PPO resin and antioxidant are uniformly mixed, and the uniformly mixed materials are added to the main feed of the twin-screw extruder, and the glass fiber powder is added to the side feed of the twin-screw extruder, and melt extrusion granulation is performed to obtain a flame retardant reinforced polyphenylene ether composition with good appearance and low warpage. The working parameters of the twin-screw extruder are: the temperature of the first zone is 190°C, the temperature of the second zone is 260°C, the temperature of the third zone is 260°C, the temperature of the fourth zone is 260°C, the temperature of the fifth zone is 270°C, the temperature of the sixth zone is 240°C, the temperature of the seventh zone is 240°C, the temperature of the die head is 250°C, and the main screw speed is 400r / min.

[0050] Example 4

[0051] In this embodiment, the number average molecular weight of the homopolymer PPO resin is 40,000, the number average molecular weight of the PS resin is 80,000, the flame retardant is a helical phosphate, the copolymer PPO resin is 2,5-dimethylphenol and 1,4-butanediol mixed in a ratio of 8:2 to form a polymerization monomer solution, which is obtained by polymerizing with acetic anhydride as a capping agent for 1.5 hours, the reinforcing fiber is 800 μm glass fiber powder, and the antioxidant is a phosphite antioxidant.

[0052] According to the weight proportions in Table 1, homopolymer PPO resin, PS resin, flame retardant, copolymer PPO resin and antioxidant are uniformly mixed, and the uniformly mixed materials are added to the main feed of the twin-screw extruder, and the glass fiber powder is added to the side feed of the twin-screw extruder, and melt extrusion granulation is performed to obtain a flame retardant reinforced polyphenylene ether composition with good appearance and low warpage. The working parameters of the twin-screw extruder are: the temperature of the first zone is 200°C, the temperature of the second zone is 270°C, the temperature of the third zone is 270°C, the temperature of the fourth zone is 270°C, the temperature of the fifth zone is 280°C, the temperature of the sixth zone is 250°C, the temperature of the seventh zone is 250°C, the temperature of the die head is 260°C, and the main screw speed is 500r / min.

[0053] Example 5

[0054] In this embodiment, the number average molecular weight of the homopolymer PPO resin is 40,000, the number average molecular weight of the PS resin is 80,000, the flame retardant is a helical phosphate, the copolymer PPO resin is 2,5-dimethylphenol and 1,4-butanediol mixed in a ratio of 9:1 to form a polymerization monomer solution, which is obtained by polymerizing with acetic anhydride as a capping agent for 2 hours, the reinforcing fiber is 800 μm glass fiber powder, and the antioxidant is a phosphite antioxidant.

[0055] According to the weight proportions in Table 1, homopolymer PPO resin, PS resin, flame retardant, copolymer PPO resin and antioxidant are uniformly mixed, and the uniformly mixed materials are added to the main feed of the twin-screw extruder, and the glass fiber powder is added to the side feed of the twin-screw extruder, and melt extrusion granulation is performed to obtain a flame retardant reinforced polyphenylene ether composition with good appearance and low warpage. The working parameters of the twin-screw extruder are: the temperature of the first zone is 200°C, the temperature of the second zone is 270°C, the temperature of the third zone is 270°C, the temperature of the fourth zone is 270°C, the temperature of the fifth zone is 280°C, the temperature of the sixth zone is 250°C, the temperature of the seventh zone is 250°C, the temperature of the die head is 260°C, and the main screw speed is 500r / min.

[0056] Comparative Example 1

[0057] Except that the copolymerized PPO resin is not added, the rest is the same as that of Example 3.

[0058] Comparative Example 2

[0059] Except for the synthesis of copolymerized PPO resin, everything else is the same as Example 3.

[0060] In this example, the copolymer PPO resin is prepared by mixing 2,5-dimethylphenol and propylene glycol in a ratio of 9:1 to form a polymerization monomer solution, and polymerizing with acetic anhydride as a capping agent for 1 hour to obtain the copolymer.

[0061] Comparative Example 3

[0062] Except that the reinforcing fiber is chopped glass fiber with a length of 1 cm, the rest is the same as that of Example 4.

[0063] The flame retardant reinforced polyphenylene ether compositions in the embodiments and comparative examples were subjected to the same drying and injection molding process to prepare mechanical properties test specimens according to ISO test standards. The specimen size is: 127mm long, 12.7mm wide, 0.4-1.6mm thick, and then the temperature is 20±2℃, the relative humidity is 65±2%RH, and the measured physical property test data are shown in Table 2. Among them, the appearance evaluation is based on a 100*100*1.6mm plate, and the gloss is tested at a 60° angle according to GB / T 8807-1988 "Plastic Mirror Gloss Test Method", and the warpage is evaluated by pressing a corner of a 100*100*1.6mm plate and the warpage is evaluated according to the height of the diagonal from the plane.

[0064] Table 2

[0065] Test items Example 1 Example 2 Example 3 Example 4 Example 5 Comparative Example 1 Comparative Example 2 Comparative Example 3 Glossiness 38 36 45 42 40 18 12 14 Warping height / cm 0.5 0.4 0.2 0.3 0.4 1.6 0.8 1.3 Flame retardant V0 thickness 0.8 0.6 0.4 0.4 0.4 0.6 1.6 0.8

[0066] As can be seen from the table, the glossiness of the polyphenylene ether compositions in Examples 3 to 5 increases with the increase in the proportion of PPO copolymer resin added. This is because the range of activity of the PPO molecular chain increases. During the injection molding process, the flexibility of the molecular chain increases, making it easier to wrap the reinforcing fiber and float on the surface, so the surface glossiness is also significantly improved. In addition, as the activity of the molecular chain segments increases, there is no steric hindrance at the ortho position of 2,6-dimethylphenol, and the warping height of the flat plate gradually decreases. The addition of PPO copolymer has a significant effect on improving the warping.

[0067] It can be seen from Example 3 and Comparative Example 1 that the copolymerized PPO resin is missing. Since the PPO resin obtained by homopolymerization of 2,6-dimethylphenol has a large steric hindrance of two ortho-CH3, the range of molecular chain activity is limited, and the wrapping of the reinforcing fiber is limited. The reinforcing fiber floats on the surface, resulting in a significantly low surface gloss. Also due to steric hindrance, the flexible chain segment of the copolymerized PPO is missing. During the molding process, the resistance between the plasticized rubber molecular chains is too large, and the reinforcing fibers cannot be evenly distributed, resulting in excessive internal stress and orientation distribution of the reinforcing fibers, which ultimately leads to obvious warping.

[0068] It can be seen from Example 3 and Comparative Example 2 that the copolymerized PPO resin monomer is changed from 1,4-butanediol to propylene glycol, the molecular chain segment repeating unit of the copolymerized PPO becomes shorter, the fluidity becomes worse, the wrapping of glass fiber powder and the residual stress of injection molding increase, resulting in warping and poor appearance. However, too many carbon atoms in the diol will affect the mechanical properties and processing properties of the material, so it is generally better not to exceed 6 carbon atoms.

[0069] From Example 3 and Comparative Example 3, it can be seen that the flame retardant effect is reduced when the reinforcing fiber is adjusted from glass fiber powder to short glass fiber, and the thickness is reduced from 0.4 to 0.8. This is because the reduction in the size of the reinforcing fiber causes the powder to overflow and disperse onto the surface of the sample during the combustion process, which has a smoke suppression effect and a synergistic effect on flame retardancy. At the same time, the warping and glossiness are also significantly reduced, which fully reflects the beneficial effects of the reasonable combination of these components.

[0070] Although this specification is described according to implementation modes, not every implementation mode includes only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

[0071] Therefore, the above description is only a preferred embodiment of the present application and is not intended to limit the scope of implementation of the present application; that is, all equivalent changes made according to the scope of the claims of the present application are within the protection scope of the claims of the present application.

Claims

1. A flame retardant reinforced polyphenylene ether composition with good appearance and low warpage, characterized in that: It is prepared from the following components in parts by weight: The copolymerized PPO resin is obtained by copolymerizing dimethylphenol and diol and is capped by a capping agent.

2. The flame retardant reinforced polyphenylene ether composition with good appearance and low warpage according to claim 1, characterized in that: The dimethylphenol is 2,6-dimethylphenol, 2,5-dimethylphenol or 2,3-dimethylphenol; and / or the number of carbon atoms in the diol is four to six.

3. The flame retardant reinforced polyphenylene ether composition with good appearance and low warpage according to claim 1, characterized in that: The number average molecular weight of the homopolymer PPO resin is 2,000-60,000.

4. The flame retardant reinforced polyphenylene ether composition with good appearance and low warpage according to claim 1, characterized in that: The PS resin is at least one of polystyrene, high impact polystyrene and syndiotactic polystyrene, and has a number average molecular weight of 80,000-120,000.

5. The flame retardant reinforced polyphenylene ether composition with good appearance and low warpage according to claim 1, characterized in that: The flame retardant is at least one of red phosphorus, cyclic phosphate, helical phosphate, triphenyl phosphate, bisphenol A bis(diphenyl phosphate), and resorcinol (diphenyl phosphate).

6. The flame retardant reinforced polyphenylene ether composition with good appearance and low warpage according to claim 1, characterized in that: The preparation method of the copolymerized PPO resin is: At least two monomers are added to a toluene solution, and a catalyst is added, and a polymerization reaction is carried out at a temperature range of 20-50° C. After the reaction is carried out for 0.5-2 hours, a capping agent and methanol are added in sequence to obtain a copolymerized PPO resin.

7. The flame retardant reinforced polyphenylene ether composition with good appearance and low warpage according to claim 1, characterized in that: The reinforcing fiber is at least one of glass fiber powder, carbon fiber powder and basalt fiber powder, and has a length of 200-800 μm.

8. The flame retardant reinforced polyphenylene ether composition with good appearance and low warpage according to claim 1, characterized in that: The antioxidant is at least one of hindered phenols, hindered amines, thioesters and phosphites.

9. The method for preparing a flame retardant reinforced polyphenylene ether composition with good appearance and low warpage according to any one of claims 1 to 8, characterized in that: The following steps are involved: Weigh each component according to weight, and mix all components except the reinforcing fiber uniformly to obtain a mixed material; The mixed material is added from the main feeding port of the twin-screw extruder, and the reinforcing fiber is added from the side feeding port of the twin-screw extruder. After melting, extrusion and granulation, a flame-retardant reinforced polyphenylene ether composition with good appearance and low warpage is obtained.

10. The preparation method according to claim 9, characterized in that: The working parameters of the twin-screw extruder are: zone one temperature 180-230°C, zone two temperature 250-270°C, zone three temperature 250-275°C, zone four temperature 250-270°C, zone five temperature 260-270°C, zone six temperature 230-240°C, zone seven temperature 230-240°C, die head temperature 240-250°C, and main screw speed 300-500r / min.

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