A flame retardant reinforced alloy material containing PET resin with stable melt flow and preparation method thereof

Abstract

The present invention relates to a flame retardant reinforced alloy material containing PET resin with stable melt flow and a preparation method thereof, comprising PBT resin, PET resin, stabilizer, flame retardant, flame retardant synergist, glass fiber, toughening agent, antioxidant, lubricant and nucleating agent. The present invention has the stability of melt flow, and can be widely used in the fields of cooling fans, motor housings, relays and plugs and sockets in the electronic and electrical industries by achieving stable continuous production to obtain structural functional components through molding processes such as injection molding, extrusion and compression molding.

Description

Technical Field

[0001] The invention belongs to the field of polymer materials, and particularly relates to a flame retardant reinforced alloy material containing PET resin with stable melt flow and a preparation method thereof. Background Art

[0002] Polyethylene terephthalate (PET) engineering plastics have been widely used in various industries due to their excellent mechanical properties, oil resistance, electrical properties, heat resistance, gloss, low water absorption and easy processing. For example, PET fiber and polyester used in the textile field have become the largest variety of chemical fiber production. PET film is mainly used for electrical insulation materials, such as capacitors, cable insulation and other substrates, used in film, X-ray film, recording tape and other film bases and basebands and capacitor films. Another use of PET is blow molding products such as polyester blow molding bottles for packaging. In addition to the above-mentioned consumer products, PET polyester is also suitable for modified plastics of functional components in the electronic and electrical and automotive industries. For example, modified products with functional additives such as glass fiber and flame retardants are used in various coil skeletons, transformers, electrical parts and housings, car lights, relays, etc.

[0003] Among the above products, except for PET as modified plastic, which is a composite material, the other polyester fibers as polyester, extruded films and blow-molded polyester bottles are all pure PET resin products. These fibers, extruded and blow-molded products have a large amount of waste materials in the production process or after consumption. With the annual growth of market consumption of polyester, the amount of waste polyester materials has also increased year by year. Due to the requirements of environmental protection, sustainable development of green economy, energy conservation and reduction of carbon emissions, especially the increased protection of marine environment in recent years, the recycling of PCR materials based on OBP (Ocean Bound Plastic) has been put on the agenda. Numerous invention patents have reported on the realization of recycling and reusing discarded polyester, such as CN201210493421 discloses adding a small amount of PET-PA6 copolymer as a compatibilizer and glass fiber to PA6 and recycled PET bottle flakes to obtain a reinforced composite material; CN201310188541 reports adding alkali-free glass fiber, nucleating agent, flame retardant and a small amount of chain extender to recycled PET material to obtain environmentally friendly flame-retardant glass fiber reinforced PET material; CN201611242249 reports adding a small amount of reactive compatibilizer of ethylene and maleic anhydride copolymer to recycled waste carpet PA66 resin and recycled PET resin alloy to realize the recycling of engineering plastics; CN201910322419 discloses a preparation method of recyclable PET modified RPET material, using glass fiber, plasticizer, mica, toughening agent, etc.; CN202210074047 discloses a phosphorus-nitrogen-containing flame retardant / antioxidant synergistic auxiliary agent for use in recycled PET, providing flame retardant properties, thermal processing stability and mechanical properties of recycled PET; the source process of the recycled PET raw materials is through the dual effects of high-temperature blow molding and extrusion shearing, or undergoes uncertainty in multiple cycles of processing, resulting in degradation, reduced molecular weight, reduced viscosity, resulting in the melt fluidity of the recycled PET being very unstable. Although the above patents report the reuse of recycled PET by different methods, there are few reports on how to control the method of obtaining a recycled PET modified material or composite material with stable melt flow. Even if there are reports, it is difficult to achieve large-scale industrial application due to the purity and cost of the synthesized nitrogen-phosphorus-containing flame retardant / antioxidant synergistic auxiliary agent. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a flame retardant reinforced alloy material containing PET resin with stable melt flow and a preparation method thereof. Due to the stability of melt flow, the material can be widely used in the fields of cooling fans, motor housings, relays, plugs and sockets in the electronic and electrical industry, etc., by achieving stable continuous production through molding processes such as injection molding, extrusion, and compression molding to obtain structural functional components.

[0005] The present invention provides a PBT flame retardant reinforced material with stable melt flow, which comprises the following components in parts by weight:

[0006] and / or ethylene-acrylate-glycidyl methacrylate terpolymer having a GMA content of 5-8%.

[0007] The epoxy equivalent and GMA content are confirmed by titration, that is, weigh about 1g of nucleating agent and dissolve it in 100ml of toluene, heat to dissolve, cool to below 60°C, accurately transfer 20ml of 0.05mol / L KOH methanol solution, heat and reflux for 1 hour, cool to room temperature, use 1% phenolphthalein ethanol solution as an indicator, and titrate with 0.05mol / L HCl-isopropanol standard solution to the end point, and calculate the epoxy equivalent or GMA content according to the formula.

[0008] The intrinsic viscosity of the PBT resin is 0.8-1.0 dl / g. The PBT resin is new PBT resin and / or recycled PBT resin.

[0009] The PET resin is new PET resin and / or recycled PET resin.

[0010] The melt flow rate of the recycled PET resin at 270°C and 1.2 kg is 50-100 g / 10 min, and the melt flow rate fluctuation rate of the recycled PET resin is 50-100%. The melt flow rate is implemented according to ISO 1133-2011 standard, and the melt flow rate fluctuation rate is defined as the change rate of the same cutting sequence between two cuttings before and after, that is, the melt flow rate fluctuation rate = (m i(1) -m k(2) ) / m i(1) ×100%,m i(1) is the weight of any cut in the first 5 cuts, m k(2) For the second 5 cuts and m i(1) The same cutting weight. The viscosity of new PET is relatively stable, so the volatility of melt flow rate is also relatively stable. However, the molecular weight and distribution of recycled PET resin vary greatly due to its different thermal history, so the viscosity fluctuates greatly, and the volatility of its melt flow rate also varies greatly. After a lot of research, the present application found that when the melt flow rate of recycled PET resin at 270°C and 1.2kg is 50-100g / 10min, and the volatility of melt flow rate is 50-100%, the melt flow stability is better, and the stability of the produced structural functional parts is better.

[0011] The flame retardant is at least one of brominated epoxy resin, brominated polystyrene, brominated polycarbonate, and diethyl aluminum phosphinate; the flame retardant synergist is at least one of antimony trioxide, melamine polyphosphate, and melamine cyanurate.

[0012] The toughening agent is at least one of ethylene-methyl acrylate binary copolymer EMA and ethylene-butyl acrylate binary copolymer EBA.

[0013] The present invention has no special restrictions on the diameter of the glass fiber. Preferably, the glass fiber is an alkali-free glass fiber with a diameter of 10-13 μm. The present invention is not limited thereto.

[0014] The antioxidant is at least one of a hindered phenol antioxidant and a phosphite antioxidant.

[0015] The lubricant is at least one of aliphatic carboxylic acid ester and polyolefin wax lubricant. Preferably, the aliphatic carboxylic acid ester is pentaerythritol tetrastearate. The polyolefin wax lubricant is oxidized polyethylene wax.

[0016] The nucleating agent is ultrafine talc. The present invention has no special restrictions on the particle size of the ultrafine talc. Preferably, the particle size D50 of the ultrafine talc is 0.5-0.7 μm. The present invention is not limited thereto.

[0017] The melt flow rate fluctuation rate of the PBT flame retardant reinforcement material is 1-5%.

[0018] Preferably, the amount of the stabilizer added is 3-6 parts. The amount of the glass fiber added is 20-35 parts. The amount of the toughening agent added is 2-5 parts. The amount of the antioxidant added is 0.1-0.5 parts. The amount of the nucleating agent added is 0.5-1.5 parts.

[0019] The present invention also provides a method for preparing a flame retardant reinforced alloy material containing PET resin with stable melt flow, comprising the following steps:

[0020] The PBT resin, the PET resin and other components except the glass fiber are uniformly mixed in a high-speed stirring mixer according to a proportion or are fed separately into a premixer through a metering feeder to obtain a premix; the premix is ​​fed into a twin-screw extruder, and the glass fiber is added in proportion in the twin-screw extruder, melt-plasticized, kneaded and mixed, extruded through a die, drawn, cooled, pelletized and dried to obtain a flame-retardant reinforced alloy material containing PET resin with stable melt flow.

[0021] When PBT resin and PET resin are recycled materials, they are dried in advance.

[0022] The mixing temperature of the twin-screw extruder is 220° C.-250° C., and the screw speed is 300-500 rpm.

[0023] The present invention also provides an application of a flame-retardant reinforced alloy material containing PET resin with stable melt flow in electronic and electrical devices, such as cooling fans, motor housings, relays, plugs and sockets, and other structural functional parts with high stability requirements.

[0024] Since the source process of recycled PET materials, such as spinning, extrusion blown film, recycling and granulation, etc., is through the dual effects of high temperature and shear, or after multiple cycles of processing, the viscosity is greatly reduced. Therefore, the melt fluidity of recycled PET materials is very unstable. If these recycled PET materials with unstable melt flow are directly used to make flame-retardant glass fiber reinforced modified materials, the flow properties of the modified materials finally obtained will also fluctuate greatly. When the modified materials are used for injection molding or extrusion molding, it is difficult to produce continuously and stably due to the unstable fluidity.

[0025] A flame retardant reinforced alloy material containing PET resin with stable melt flow is prepared, and an epoxy resin or ethylene-acrylate-methacrylate glycidyl ester terpolymer that can react with the terminal carboxyl group of recycled PET is used as a stabilizer for stabilizing the melt flow. In view of the instability of the recycled PET source and the volatility of its melt index, the recycled PET source with a relatively low melt index has a simple process such as one or two processing processes, while the PET with a relatively high melt index may have undergone multiple processing processes. A certain amount of stabilizer is used, and a high amount of stabilizer is used for the recycled PET with a high melt index, and a low amount of stabilizer is used for the recycled PET with a low melt index, so that the melt flowability of the flame retardant reinforced alloy material containing PET resin obtained at last is relatively stable during the two melt index test processes (even if the melt flow rate volatility of the recycled PET resin is as high as 50-1 00%, after adopting the scheme of the present invention, the melt flow rate fluctuation range of the flame retardant reinforced alloy material containing PET resin is controlled within 1-5%), the melt flow test values ​​are not much different (the difference between the second and the first melt flow, the difference fluctuation range is between -1.5-4.7), and the weight change of the sample cut each time is relatively small. Compared with the case where no stabilizer is used or the amount of stabilizer is insufficient, the melt flowability of the flame retardant reinforced alloy material containing PET resin obtained in two tests fluctuates greatly (the difference between the second and the first melt flow, the difference fluctuation range is between -38.2-20.3), and the weight change of the sample cut each time is also obvious; if the amount of stabilizer is too high, the melt flowability is significantly reduced. The gradual decrease trend may be due to the excessively high epoxy content and the occurrence of a cross-linking reaction during the melt flow process.

[0026] Beneficial Effects

[0027] The present invention has the stability of melt flow and can achieve stable continuous production to obtain structural functional components through molding processes such as injection molding, extrusion, and compression molding. It can be widely used in the fields of cooling fans, motor housings, relays, plugs and sockets in the electronic and electrical industry. DETAILED DESCRIPTION

[0028] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.

[0029] Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art.

[0030] Recycled PET resin:

[0031] In order to obtain reusable recycled PET resin, firstly, waste PET resin materials of various types from various sources are collected, and then classified according to the types, colors, and uses of the waste PET resin materials; then, the waste PET resin materials are compressed and packaged; then, the packaged waste PET resin materials are transported to a waste treatment plant. In the present invention, the waste PET resin materials are scraps, defective products, and scrapped products generated in the process of producing PET filaments, PET bristles, and PET films. After manual identification, sorting, classification, and selection of materials other than PET resin by experienced workers, the pure PET filaments, silk threads, film sheets, etc. are fed, melted, and extruded into granules through a single-screw extruder, but the present invention is not limited thereto.

[0032] The processing method of recycled PET resin includes: for example: physically and mechanically crushing a part of the waste PET resin material to reduce the time and energy consumption required for melting the recycled material; then, melting the crushed recycled material so that the recycled material is in a molten state; then, filtering the recycled material in a molten state with a screen to remove solid impurities in the recycled material; finally, extruding and granulating the filtered recycled material to form the recycled PET resin with a certain melt flow rate and melt flow rate volatility. The present invention is not limited to this.

[0033] The raw materials used in the following examples and comparative examples are as follows:

[0034] PBT resin:

[0035] A1: 1200-211M (Changchun Chemical Industry, Taiwan, China), intrinsic viscosity is 0.83dl / g;

[0036] A2: 1100-211M (Changchun Chemical Industry, Taiwan, China), intrinsic viscosity is 1.0dl / g;

[0037] PET resin:

[0038] B1: recycled PET, PET-YH002 (Jinjiang Yonghong Recycling Resources Co., Ltd.), melt flow rate 51g / 10min@270℃, 1.2kg, melt flow rate fluctuation rate 50%;

[0039] B2: recycled PET, PET-YH003 (Jinjiang Yonghong Recycling Resources Co., Ltd.), melt flow rate 76g / 10min@270℃, 1.2kg, melt flow rate fluctuation rate 80%;

[0040] B3: recycled PET, r-PET Pellet (PT POLINDO UTAMA) with a melt flow rate of 98 g / 10 min @ 270 °C, 1.2 kg, and a melt flow rate fluctuation of 100%;

[0041] B4: Ordinary new material PET resin, PET BG80, Yizheng Chemical Fiber, melt flow rate is 8g / 10min@270℃, 1.2kg, melt flow rate fluctuation rate is 1-3%;

[0042] Stabilizer:

[0043] C1: Epoxy resin YD-019, epoxy equivalent weight 2800g / eq, Guodu Chemical;

[0044] C2: ethylene-acrylate-glycidyl methacrylate terpolymer AX8750, GMA content 5%, Arkema;

[0045] C3: ethylene-acrylate-glycidyl methacrylate terpolymer AX8900, GMA content 8%, Arkema;

[0046] C4: Epoxy resin YD-020, epoxy equivalent weight 4000g / eq, Guodu Chemical;

[0047] C5: ELVALOY 4170, ethylene-acrylate-glycidyl methacrylate terpolymer, GMA content 10%, Dow Chemical;

[0048] Flame retardant:

[0049] Halogenated flame retardant: D1: Brominated epoxy F-2100, Dead Sea bromine;

[0050] Halogen-free flame retardant: D2: Aluminum diethylphosphinate EXOLIT OP 1230, Clariant;

[0051] Flame retardant synergist:

[0052] Halogenated flame retardant synergist: E1: antimony trioxide S-05N, Chenzhou Antimony Industry;

[0053] Halogen-free flame retardant synergist: E2: melamine polyphosphate MPP, Shouguang Weidong Chemical;

[0054] Toughening agent:

[0055] F1: EMA ethylene-methyl acrylate copolymer ELVALOY AC 1125, DuPont;

[0056] F2: EBA ethylene-butyl acrylate copolymer ELVALOY AC 34035, DuPont;

[0057] Nucleating agent: G: ultrafine talc powder HTP Ultra5, particle size D50 is 0.65 μm, Liaoning Aihai;

[0058] Fiberglass:

[0059] H1: ECS13-4.5-534A (glass fiber diameter 13μm, Jushi Group);

[0060] H2: HMG436S-10-4.0 (glass fiber diameter 10 μm, Taishan Glass Fiber Co., Ltd.);

[0061] Lubricant:

[0062] I1: oxidized polyethylene wax, PED 521, Clariant;

[0063] I2: pentaerythritol tetrastearate, PETS, hair base;

[0064] Antioxidants:

[0065] J: Antioxidant 1010 and 168 are compounded in a mass ratio of 1:1, Lianlong.

[0066] The composite materials of each embodiment and comparative example were prepared by the following process:

[0067] (1) The recovered PET particles are dried at 130° C. for more than 3 hours, and the moisture content is controlled to be less than 0.03%;

[0068] (2) Prepare various raw materials according to the ratio in Table 1;

[0069] (3) The recycled PET particles or ordinary PET particles after drying are directly mixed with PBT resin and flame retardant, flame retardant synergist, stabilizer, antioxidant, nucleating agent, and lubricant in a high-speed stirring mixer in proportion to be evenly mixed or separately fed into a premixer through a metering feeder to obtain a premix.

[0070] (4) The mixed material is fed into a twin-screw extruder, and the feed rate is adjusted to 450-800 kg / hour. The alkali-free glass fiber is added in proportion by side feeding in the twin-screw extruder. The temperatures of the screws of the twin-screw extruder from the feed port to the die are 220° C., 230° C., 230° C., 240° C., 250° C., 240° C., 240° C., 230° C., and 240° C., respectively. The screw speed is 400 rpm. Under the conveying and shearing action of the twin-screw extruder, the mixed material is fully melted and plasticized, kneaded and mixed, extruded through the die, stretched, cooled, pelletized, dried, and finally packaged.

[0071] The embodiments and comparative examples were subjected to the following test methods or test standards:

[0072] The product obtained by extrusion and pelletization is dried at 120-130° C. for 3-4 hours; and test specimens are prepared by injection molding according to corresponding standards.

[0073] The tensile strength is tested according to ISO 527-2012 standard, and the flame retardancy is tested according to UL 94-2020 standard;

[0074] Melt flow stability: Use a melt index tester, take 8-10g of sample particles, dry them at 120℃ for 4 hours, add them to the barrel of the melt index tester, preheat them at the set temperature for 4 minutes, then add load, extrusion and cutting interval is 5s, cut them 5 times in a row. Cut two 5 times, the interval between the first 5 times and the second 5 times is 10s, record the weight of the cut sample, observe the weight change, and record the melt flow rate fluctuation rate.

[0075] Table 1 Component comparison between the embodiment and the comparative example

[0076]

[0077]

[0078] Table 2 Test results of embodiments and comparative examples

[0079]

[0080]

[0081]

[0082]

[0083] It can be seen from Examples 1-13 that after adopting the solution of the present invention, the fluctuation range of the melt flow rate of the recycled PBT flame retardant reinforcement material can be controlled within 1-5%, which is similar to the ordinary new material PBT flame retardant reinforcement material of Example 14. By comparing Comparative Examples 1 and 4 with Example 1, it can be seen that when no stabilizer or lubricant is added, the fluctuation range of the melt flow rate of the recycled PBT flame retardant reinforcement material is still large, and the flame retardant performance is also poor. It can be seen from Comparative Examples 2 and 3 that when the amount of stabilizer added is too much or too little, the technical effect to be achieved by the present invention cannot be achieved. It can be seen from Comparative Examples 5 and 6 that when the parameters of adding the stabilizer do not meet the above requirements, the technical effect to be achieved by the present invention cannot be achieved.

Claims

1. A flame retardant reinforced alloy material containing PET resin with stable melt flow, characterized in that: In parts by weight, it comprises the following components: 30~50 parts of PBT resin; PET resin 10~30 parts; 2-8 parts of stabilizer; Flame retardant 8~15 parts; Flame retardant synergist 2.5~8 parts; Glass fiber 0~35 parts; Toughener 0-5 parts; Antioxidant 0~0.5 parts; 0.5~1.5 parts of lubricant; Nucleating agent 0~0.5 parts; Wherein, the PET resin is recycled PET resin; the stabilizer is an epoxy resin with an epoxy equivalent of 2500-3000 g / eq; the lubricant is at least one of aliphatic carboxylic acid ester and polyolefin wax lubricant; or 30~50 parts of PBT resin; PET resin 10~30 parts; 2-8 parts of stabilizer; Flame retardant 8~15 parts; 2.5~8 parts of flame retardant synergist; 30~35 parts of glass fiber; 2-5 parts of toughening agent; Antioxidant 0~0.5 parts; 0.5~1.5 parts of lubricant; Nucleating agent 0~0.5 parts; Among them, the PET resin is recycled PET resin; the stabilizer is an ethylene-acrylate-glycidyl methacrylate terpolymer with a GMA content of 5%; and the lubricant is at least one of aliphatic carboxylic acid ester and polyolefin wax lubricant.

2. The flame retardant reinforced alloy material containing PET resin with stable melt flow according to claim 1, characterized in that: The PBT resin is new PBT resin and / or recycled PBT resin.

3. The flame retardant reinforced alloy material containing PET resin with stable melt flow according to claim 2, characterized in that: The melt flow rate of the recycled PET resin at 270° C. and 1.2 kg is 50-100 g / 10 min, and the volatility of the melt flow rate of the recycled PET resin is 50-100%.

4. The flame retardant reinforced alloy material containing PET resin with stable melt flow according to claim 1, characterized in that: The flame retardant is at least one of brominated epoxy resin, brominated polystyrene, brominated polycarbonate, and diethyl aluminum phosphite; the flame retardant synergist is at least one of antimony trioxide, melamine polyphosphate, and melamine cyanurate; and the toughening agent is at least one of ethylene-methyl acrylate copolymer EMA and ethylene-butyl acrylate copolymer EBA.

5. The flame retardant reinforced alloy material containing PET resin with stable melt flow according to claim 1, characterized in that: The melt flow rate fluctuation rate of the flame retardant reinforced alloy material is 1-5%.

6. The flame retardant reinforced alloy material containing PET resin with stable melt flow according to claim 1, characterized in that: The antioxidant is at least one of a hindered phenol antioxidant and a phosphite antioxidant; and the nucleating agent is ultrafine talc.

7. The flame retardant reinforced alloy material containing PET resin with stable melt flow according to claim 1, characterized in that: The amount of the stabilizer added is 3-6 parts.

8. A method for preparing a flame retardant reinforced alloy material containing PET resin with stable melt flow as claimed in claim 1, comprising the following steps: The PBT resin, the PET resin and other components except the glass fiber are uniformly mixed in a high-speed stirring mixer according to a proportion or are fed separately into a premixer through a metering feeder to obtain a premix; the premix is ​​fed into a twin-screw extruder, and the glass fiber is added in proportion in the twin-screw extruder, melt-plasticized, kneaded and mixed, extruded through a die, drawn, cooled, pelletized and dried to obtain a flame-retardant reinforced alloy material containing PET resin with stable melt flow.

9. The preparation method according to claim 8, characterized in that: The mixing temperature of the twin-screw extruder is 220° C.-250° C., and the screw speed is 300-500 rpm.

10. Use of the flame-retardant reinforced alloy material containing PET resin and having stable melt flow as claimed in claim 1 in electronic and electrical devices.

Images