Reinforced and toughened PET (Polyethylene Terephthalate) engineering plastic suitable for plastic extrusion molding and preparation method of reinforced and toughened PET engineering plastic

Abstract

The invention provides reinforced and toughened PET engineering plastic suitable for plastic extrusion molding as well as a preparation method and application of the reinforced and toughened PET engineering plastic. The reinforced and toughened PET engineering plastic suitable for extrusion molding and the preparation method of the reinforced and toughened PET engineering plastic aim at solving the technical problem that application of existing PET resin in the field of pipe rods for engineering is limited due to the fact that the existing PET resin is long in molding period and low in strength and toughness in the processing process. The preparation method specifically comprises the following steps: mixing oyster shell powder coated SiO2 inorganic micro-nano functional powder, a surface activity modifier, a POE-g-GMA grafting compatilizer and a processing aid, and carrying out melt extrusion granulation to obtain toughened composite master batch; blending the PET slices, the toughening composite master batch, the PET nucleating agent, the PBT crystallization accelerant, the alkali-free glass fiber, the antioxidant, the anti-ultraviolet light absorber and the coupling agent, melting, extruding and granulating to obtain the PET / PBT composite material. The prepared PET engineering plastic is subjected to extrusion molding by adopting an extruder with the length-diameter ratio being greater than or equal to 36: 1, so that the industrial production of the pipe rod for PET plastic engineering can be realized.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer materials, and in particular relates to a reinforced and toughened PET engineering plastic suitable for plastic extrusion molding and a preparation method thereof. Background Art

[0002] Polyethylene terephthalate (PET) is a thermoplastic with excellent performance, good mechanical properties and electrical insulation. It is widely used in synthetic fibers, film sheets and packaging containers (such as beverage bottles and medicine bottles) because of its excellent wear resistance, heat resistance and chemical corrosion resistance. The synthetic monomer (terephthalic acid, PTA) of PET is abundant and inexpensive, and the synthetic unit consumption is the lowest among the five major general engineering plastics. In addition, PET can be recycled and the source of recycled materials is abundant. Therefore, the engineering of PET plastics will replace some of the more expensive polybutylene terephthalate (PBT) and polyamide (PA) engineering plastics, which will bring considerable economic and social benefits. However, due to the main molecular chain structure of PET, it is necessary to complete the transformation from cis configuration to trans configuration during the crystallization process, resulting in the disadvantages of slow crystallization speed, long molding cycle and poor impact toughness of products in the PET production process, which limits its application in extrusion molding methods and the use scenarios as engineering plastics.

[0003] At present, there are many research reports on improving the crystallization rate of PET, but only a few companies such as DuPont, General Electric and BTE in Germany can solve the technical problems of PET gate breaking and easy flow at the same time, and keep the products with excellent mechanical and thermal properties. Their core technology is to use the nucleation effect of organic carboxylates or polymer ionomers to improve the crystallization rate of PET. Due to the high confidentiality and absolute monopoly of foreign companies' technical solutions, the sales price of PET engineering plastics in China is very high, which is also one of the reasons why the domestic use of PET engineering plastics cannot increase significantly.

[0004] Compared with foreign countries, the development of domestic PET engineering plastics is relatively slow and the varieties are single. Beijing Research Institute of Chemical Industry, Guangzhou Kingfa Technology Co., Ltd. and Shanghai Petrochemical have all developed PET engineering plastics using glass fiber (GF) reinforcement technology, including BNN-3030PET reinforced plastics, with a heat deformation temperature of up to 240°C. However, the above PET engineering plastic technology is still immature, and products can only be prepared by injection molding. Lv Tongjian et al. used polyester copolymer as a crystallization nucleating agent for PET, polyethylene glycol and KTR-3C as a composite crystallization promoter for PET, and added silane coupling agents and antioxidants. Through 30% glass fiber reinforcement, a PET / GF composite material with a fast crystallization rate and a short molding cycle was prepared by blending, and excellent mechanical properties, thermal properties and flow properties, but the impact resistance of the PET / GF composite material is still poor. Based on the screening of nucleating agents, Xiang Shixin et al. prepared 30% glass fiber reinforced PET engineering plastics with excellent performance, which is close to the performance of similar foreign products and exceeds that of 30% glass fiber reinforced PBT. The injection mold temperature can be reduced to about 70°C, the molding cycle is greatly shortened, and the molding processability is similar to that of PBT. However, the melt index (MFR) of this material is too high to be suitable for extrusion molding.

[0005] In summary, the glass fiber reinforced PET engineering plastics prepared by the existing technical solutions have not solved the problem that they cannot be used in the preparation of extrusion molded products due to the high melt flow rate. Therefore, in view of the problems existing in the prior art and market demand, the present invention provides a preparation method of reinforced and toughened PET engineering plastics suitable for plastic extrusion molding process, and applies it to the extrusion molding industrial production of high-strength, high-modulus and high-impact strength plastic pipes and rods, expanding the application field of PET engineering plastics. Summary of the invention

[0006] The object of the present invention is to provide a method for preparing a reinforced and toughened PET engineering plastic suitable for plastic extrusion molding, comprising the following steps:

[0007] S1 Preparation of oyster shell powder@SiO 2 Inorganic micro-nano toughened composite masterbatch: oyster shell powder@SiO 2 The inorganic micro-nano functional powder was put into a mixing device, and a surfactant modifier, a POE-g-GMA grafting compatibilizer and a processing aid were added. After stirring and heating, the mixture was melt-extruded and granulated to obtain POE-g-GMA (oyster shell powder @ SiO 2 ) Toughened composite masterbatch;

[0008] S2 prepares PET engineering plastics: PET chips, toughened composite masterbatch prepared in S1, PET nucleating agent, PBT crystallization accelerator, alkali-free glass fiber, antioxidant, anti-ultraviolet absorber and coupling agent are blended, melt-extruded and granulated to obtain reinforced and toughened PET engineering plastics suitable for plastic extrusion molding.

[0009] In a preferred embodiment, in step S1, the following components are included by weight: 50-90 parts of POE-g-GMA grafting compatibilizer, oyster shell powder @SiO 2 10 to 40 parts of inorganic micro-nano functional powder, 1.4 to 3.0 parts of surfactant modifier and 1.5 to 5.0 parts of processing aid; preferably, 50 to 70 parts of POE-g-GMA grafted compatibilizer, oyster shell powder @SiO 2 30-40 parts of inorganic micro-nano functional powder, 1.4-2.0 parts of surfactant modifier and 1.5-3.0 parts of processing aid; more preferably, the POE-g-GMA grafted compatibilizer, oyster shell powder @SiO 2 The total weight parts of the inorganic micro-nano functional powder, the surfactant modifier and the processing aid are 100 parts in total.

[0010] In a preferred embodiment, in step S1, the oyster shell powder @SiO 2 The inorganic micro-nano functional powder is prepared by the carbonation method disclosed in Chinese Patent No. 202410174319X using oyster shell powder as the calcium carbonate source. 2 Content ≤15%, CaCO 3 Content ≥85%.

[0011] Oyster shells are composed of about 95% CaCO 3 and about 5% organic matter. Since organic matter converts CaCO 3 The powder was evenly coated to form a CaCO 3 The present invention adopts the carbonation method to prepare oyster shell powder @SiO 2 The micro-nano binary structure is composed of micron-sized oyster shell powder and nano-SiO2 uniformly coated on the surface. 2 The composite particles have the characteristics of rough surface, blunt edges and corners, large oil absorption value and specific surface area, and due to SiO 2 The coating structure makes it have excellent anti-ultraviolet aging performance and acid resistance stability. 2 The whiteness of inorganic micro-nano functional powder is ≥95%, and it is compatible with CaCO 3Compared with the raw materials, the ultraviolet reflectivity is increased by 55%, the specific surface area is increased by 18 to 20 times, and it has excellent mechanical and thermal stability. At the same time, the material also has nano-SiO 2 Reinforcement and CaCO 3 The filling effect can significantly reduce SiO 2 Compared with the use of calcium carbonate, it can improve the mechanical properties, anti-ultraviolet aging performance and acid resistance stability of the products.

[0012] In the present invention, oyster shell powder@SiO 2 Micro-nano functional powder material is compounded with POE-g-GMA thermoplastic elastomer to prepare oyster shell powder@SiO 2 Inorganic micro-nano toughened composite masterbatch forms a "core-shell" structure, which can improve the comprehensive indicators of the product. When this material is filled into the PET / GF composite material, it can further improve the mechanical properties, UV aging resistance and acid and alkali stability of the product, while also greatly increasing the melt viscosity, reducing the melt flow rate of the composite material, and avoiding the warping of PET engineering plastic products caused by the addition of glass fiber (GF).

[0013] In a preferred embodiment, in step S1, the grafting rate of the POE-g-GMA grafted compatibilizer is 0.8-2.0%, and the melt flow rate (MFR) is 0.8-3.0 g / 10 min; preferably, the source of the POE-g-GMA grafted compatibilizer can be purchased from outside or prepared by itself; more preferably, a homemade POE-g-GMA grafted compatibilizer is used, with a grafting rate of 1.7-1.9% and an MFR of 2.8-3.0 g / 10 min.

[0014] In a preferred embodiment, in step S1, the surfactant modifier includes one or more of stearic acid, an aluminate coupling agent, a titanate coupling agent and a silane coupling agent; preferably, the surfactant modifier is a compound of an aluminate coupling agent with an aluminum content ≥ 8% and stearic acid in a mass ratio of 3:1.

[0015] In a preferred embodiment, in step S1, the processing aid includes one or more of ethylene bisstearamide (EBS), PE wax, polyethylene glycol glycidyl ether, antioxidant, liquid paraffin and dimethyl silicone oil; preferably, the processing aid is a composite of PE wax, polyethylene glycol glycidyl ether and liquid paraffin.

[0016] In a preferred embodiment, in step S1, the stirring and heating includes stirring at 200-400 rpm to above 120°C.

[0017] In a preferred embodiment, in step S1, the mixing device is a high-speed mixer.

[0018] In a preferred embodiment, in step S1, the melt extrusion temperature is 150-200°C; preferably, the melt extrusion equipment adopts a parallel co-rotating twin-screw extruder with a length-to-diameter ratio of ≥40:1, and air-cooled strand granulation is used for production.

[0019] In a preferred embodiment, in step S2, the following components are included by weight: 40-65 parts of PET chips, 10-20 parts of toughened composite masterbatch prepared in S1, 0.5-1.5 parts of PET nucleating agent, 4.5-20 parts of PBT crystallization accelerator, 15-30 parts of alkali-free glass fiber, 0.1-0.5 parts of antioxidant, 0.5-2.0 parts of anti-ultraviolet absorber and 0.05-0.3 parts of coupling agent; preferably, the 40-55 parts of PET chips, the toughened composite masterbatch prepared in S1 13.5-19.5 parts of toughened composite masterbatch, 0.6-0.7 parts of PET nucleating agent, 4.5-5.5 parts of PBT crystallization accelerator, 30 parts of alkali-free glass fiber, 0.3-0.5 parts of antioxidant, 0.5-1.0 parts of anti-ultraviolet absorber and 0.3 parts of coupling agent; more preferably, the total weight parts of the PET slice, the toughened composite masterbatch prepared by S1, the PET nucleating agent, the PBT crystallization accelerator, the alkali-free glass fiber, the antioxidant, the anti-ultraviolet absorber and the coupling agent add up to 100 parts.

[0020] In the present invention, the epoxy groups in the toughened composite masterbatch raw material POE-g-GMA can react with the terminal hydroxyl and terminal carboxyl groups in PET to generate POE-co-PET block copolymers, so that POE forms a stable dispersed phase in the PET matrix. At the same time, the reduction of hydroxyl and carboxyl groups in PET also fundamentally improves the anti-wet and heat stability of PET resin. In addition, considering the slow crystallization rate of PET resin, it is the main reason restricting PET engineering. The present invention uses PBT copolyester with good compatibility with PET and a crystallization rate ten times that of PET as a crystallization promoter, and uses organic acid salts and high molecular ionomers with synergistic nucleation as composite nucleating agents, and the crystallization promotion effect is more obvious. Further, the present invention found in the experiment of glass fiber (GF) reinforced PET engineering plastics that the screw combination has a great influence on the mechanical properties of GF reinforced PET composite materials. By adjusting the screw combination at the plasticizing melting section and the GF shearing section in the parallel co-rotating twin-screw extruder, the aspect ratio of the glass fiber is maintained, so that the mechanical properties of the GF reinforced PET composite material are not greatly affected. Therefore, in the extrusion molding process of the PET engineering plastic of the present invention, a parallel co-rotating twin-screw extruder with a screw length-to-diameter ratio of ≥36:1 is used.

[0021] In a preferred embodiment, in step S2, the intrinsic viscosity of the PET chips is 0.7-1.2 dl / g, and the chips are fully dried before use to make their moisture content ≤0.02%; preferably, the source of the PET chips includes commercial PET chips and / or recycled PET carbonated beverage bottles after crushing, viscosity enhancement and chain extension; more preferably, the intrinsic viscosity of the PET chips is 0.75-1.0 dl / g; most preferably, the intrinsic viscosity of the PET chips is 0.75-0.85 dl / g

[0022] In a preferred embodiment, in step S2, the PET nucleating agent includes one or more of polytetrafluoroethylene powder, sodium stearate, sodium benzoate, and sodium salt of ethylene-methacrylic acid copolymer (Surlyn); preferably, a composite nucleating agent of sodium salt of ethylene-methacrylic acid copolymer (Surlyn-8920) and sodium benzoate is used in a mass ratio of 3:1.

[0023] In a preferred embodiment, in step S2, the PBT crystallization accelerator is a PBT slice having an intrinsic viscosity of 0.8-1.2 dl / g, which is fully dried before use to have a moisture content of ≤0.02%; preferably, the intrinsic viscosity of the PBT slice is 1.0-1.06 dl / g.

[0024] In a preferred embodiment, in step S2, the alkali-free glass fiber includes one or two of alkali-free 2400tex and 4800tex long glass fiber winding yarns; preferably, the alkali-free glass fiber is a mixture of 2400tex and 4800tex long glass fiber winding yarns in a length ratio of (1:1); more preferably, the alkali-free glass fiber is added from the exhaust hole of the screw extruder.

[0025] In a preferred embodiment, in step S2, the antioxidant includes one or more of antioxidant 1010, antioxidant 168 and antioxidant 215B; preferably, the antioxidant is a mixture of antioxidant 1010 and antioxidant 168 in a mass ratio of 1:1.

[0026] In a preferred embodiment, in step S2, the anti-ultraviolet absorber includes a composite anti-ultraviolet absorber composed of trimethylolpropane triglycidyl ether and bistrifluoromethanesulfonyl imide, UV3638 and UV380; preferably, the mass ratio of trimethylolpropane triglycidyl ether and bistrifluoromethanesulfonyl imide in the composite anti-ultraviolet absorber is 7:1.

[0027] In a preferred embodiment, in step S2, the coupling agent includes silane coupling agent KH-550.

[0028] In a preferred embodiment, in step S2, the blending conditions of the PET chips, the toughened composite masterbatch prepared in S1, the PET nucleating agent, the alkali-free glass fiber, the antioxidant, the anti-ultraviolet absorber and the coupling agent include: the stirring mixing speed is 200 to 400 rpm, and the stirring time is 5 to 8 minutes; preferably, the mixing equipment is a high-speed mixer.

[0029] In a preferred embodiment, in step S2, the melt extrusion equipment uses a parallel co-rotating twin-screw extruder with a length-to-diameter ratio of ≥36:1; preferably, the melt extrusion equipment uses a parallel co-rotating twin-screw extruder with a length-to-diameter ratio of 48:1.

[0030] In a preferred embodiment, in step S2, the melt extrusion temperature is 190-250°C, and the screw speed is 410-420 rpm.

[0031] In a preferred embodiment, in step S2, water-cooled strand granulation is used, and the MFR (260° C., 2.16 kg) of the granulated particles is ≤2.0 g / 10 min;

[0032] In a preferred embodiment, in step S2, the prepared reinforced and toughened PET engineering plastic suitable for plastic extrusion molding has a tensile strength of up to a maximum of 120 MPa; a flexural strength of over 85 MPa; a flexural modulus of over 4500 MPa; a notched impact strength of over 18 MPa; a heat deformation temperature of ≥100°C; and a melt flow rate (MFR) (260°C, 2.16 kg) ≤2.0 g / 10 min.

[0033] Another object of the present invention is to provide a reinforced and toughened PET engineering plastic prepared by any one of the above methods.

[0034] Another object of the present invention is to provide an application of the reinforced and toughened PET engineering plastic prepared by any of the above methods to prepare pipe and rod products by extrusion molding process. Specifically, the prepared PET engineering plastic can be extruded by selecting conventional molds according to the target pipe and rod products and using conventional methods through a single screw extruder with a length-to-diameter ratio of ≥36:1 to prepare oyster hanging rods for offshore aquaculture oyster racks, platform brackets for aquaculture cages, agricultural greenhouse brackets, broom handles, mops, clothes drying racks, snow shovel handles and other products.

[0035] Compared with the prior art, the technical solution of the present invention has the following advantages:

[0036] 1. The scheme of the present invention is based on the principle of molten chemical reaction technology, and realizes the engineering materialization of quasi-engineering plastic PET with large output and low cost, and effectively solves the technical problem that the melt flow rate of PET is high and it is not suitable for extrusion molding process during the engineering materialization process.

[0037] 2. The present invention adopts the ternary composite theory to graft ethylene-octene copolymer toughening agent (POE) with glycidyl methacrylate (GMA) compatibilizer and activated oyster shell powder @SiO 2 Micro-nano functional materials were composited to prepare POE-g-GMA / oyster shell powder@SiO with a "core-shell" structure. 2 The toughened composite masterbatch not only toughens the PET resin, but also minimizes the adverse effects on mechanical properties. In addition, the addition of the toughened composite masterbatch also greatly increases the viscosity of the blended material and reduces the MFR, making it suitable for the requirements of the extrusion molding process for the melt flow rate.

[0038] 3. The present invention improves the compatibility with PET materials by compounding PET crystallization nucleating agent and alkali-free glass fiber, and greatly improves the crystallization rate in PET molding through the synergistic effect of PBT, a crystallization accelerator with a fast crystallization speed, thereby ensuring the smooth processing and molding of PET engineering plastics.

[0039] 4. Based on the viscosity similarity principle in molten chemical reaction technology, the present invention solves the problem of determining the blending processing temperature between PET chips, PBT chips and toughened composite masterbatch, ensuring that the viscosity of the three raw materials is similar and they are fully, quickly and evenly dispersed at the determined processing temperature.

[0040] 5. In the technical solution of the present invention, by adjusting the screw combination at the plasticizing and melting section and the GF shearing section in the parallel co-rotating twin-screw extruder, the aspect ratio of the glass fiber is maintained, so that the mechanical properties of the GF-reinforced PET composite material are not significantly affected.

[0041] 6. The reinforced and toughened PET engineering plastic prepared by the present invention is extruded by a single screw extruder with a screw length-to-diameter ratio of ≥36:1 to obtain a plastic product with excellent performance.

[0042] 7. The preparation process provided by the present invention is simple, has low energy consumption, a safe and environmentally friendly production process, a short operation time, easy-to-control operation steps, is good for the production environment, and is suitable for large-scale continuous production. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] These and / or other aspects and advantages of the present invention will become more clear and easier to understand from the following detailed description of the embodiments of the present invention in conjunction with the accompanying drawings, in which:

[0044] Figure 1 Oyster shell powder @SiO prepared in Example 1 of the present invention 2 SEM images of the composite particles. DETAILED DESCRIPTION

[0045] In order to enable those skilled in the art to better understand the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods, but it should be understood that the protection scope of the present invention is not limited to the specific implementation methods.

[0046] The embodiment of the present invention provides a glass fiber (GF) and oyster shell powder @SiO 2 The reinforced and toughened PET engineering plastics of micro-nano functional powder toughened composite masterbatch and the preparation method thereof further provide an application method of the reinforced and toughened PET engineering plastics in the field of extruded pipe and rod products, thereby effectively solving the problem in the prior art that PET engineering plastics cannot be used in the preparation of extruded products due to their own properties.

[0047] The technical solution of the present application is described in detail below through specific embodiments:

[0048] Unless otherwise specified, the technical means used in the present invention are conventional means well known to those skilled in the art, and the various raw materials, reagents, instruments and equipment used in the present invention can be purchased from the market or prepared by existing methods. The reagents used in the present invention are analytically pure unless otherwise specified. The oyster shell powder used in the present invention is derived from the cleaned and pre-dried oyster shell powder in Qingdao, Shandong, and its particle size is 500-800 mesh.

[0049] In the present invention, parts by weight may be μg, mg, g, kg or other weight units known in the art, or multiples thereof, such as 1 / 10, 1 / 100, 10 times, 100 times or the like.

[0050] Example 1

[0051] Preparation of oyster shell powder@SiO 2 Inorganic micro-nano functional powder, including the following steps:

[0052] (1) Sodium silicate and oyster shell powder were weighed in a mass ratio of 1:5 and placed in beakers respectively to prepare a sodium silicate solution with a mass fraction of 8.4% and an oyster shell powder suspension with a solid content of 21%;

[0053] (2) mixing the sodium silicate solution and the oyster shell powder suspension, stirring the mixture with an electric stirrer while heating it to 60° C., with a stirring speed of 400 r / min and a stirring time of 20 min;

[0054] (3) Introduce CO into the system 2 A mixture of CO and air 2 The flow ratio of CO to air is 1:3. 2The flow rate was 1 L / min, and the pH value of the system was monitored in real time. When the pH value dropped and stabilized to 8, the ventilation was stopped, and the mixture was kept at 60 °C for 2 h, centrifuged, dried at 105 °C, and ground to less than 200 meshes to obtain oyster shell powder @SiO 2 Inorganic micro-nano functional powder.

[0055] Example 2

[0056] A method for preparing reinforced and toughened PET engineering plastics suitable for plastic extrusion molding:

[0057] (1) Oyster shell powder@SiO 2 Preparation of inorganic micro-nano toughened composite masterbatch: 38 parts of oyster shell powder@SiO prepared in Example 1 were added. 2 Inorganic micro-nano functional powder, 58 parts of POE-g-GMA grafted compatibilizer, 1.0 parts of aluminate coupling agent, 0.4 parts of stearic acid, 2.0 parts of polyethylene glycol glycidyl ether, and 0.6 parts of liquid paraffin were put into a high-speed mixer, stirred evenly at 300 rpm, and then transferred to a parallel co-rotating twin-screw extruder with a length-to-diameter ratio of 40:1. The extruder barrel temperature was controlled at 150°C to 200°C; the screw speed was 450 rpm to obtain POE-g-GMA / oyster shell powder@SiO 2 Toughened composite masterbatch.

[0058] (2) Preparation of PET engineering plastics suitable for extrusion molding: by weight, 49.75 parts of pre-dried PET chips, 5.0 parts of pre-dried PBT chips, 13.5 parts of toughened composite masterbatch, 0.65 parts of Surlyn-8920, 0.3 parts of a mixture of antioxidant 1010 and antioxidant 168 (by mass ratio of 1:1), 0.5 parts of anti-ultraviolet absorber UV380 and 0.3 parts of silane coupling agent KH-550 were put into a high-speed mixer, stirred and mixed, and then the mixture was stirred and mixed. The speed was 350 rpm, the stirring time was 8 min, and the material was discharged into a parallel co-rotating twin-screw extruder with an aspect ratio of 48:1 after module arrangement. 30 parts of 2400 tex and 4800 tex long glass fiber winding yarns were added from the exhaust hole of the twin-screw extruder according to the length ratio (1:1). The melt extrusion temperature was 190-245 ° C, the screw speed was 415 rpm, and the water-cooled drawing was granulated to obtain glass fiber (GF) and oyster shell powder @SiO suitable for extrusion molding process. 2 Micro-nano functional powder toughened composite masterbatch reinforces and toughens PET engineering plastics.

[0059] Example 3

[0060] A method for preparing reinforced and toughened PET engineering plastics suitable for plastic extrusion molding:

[0061] (1) Oyster shell powder@SiO 2 Preparation of inorganic micro-nano toughened composite masterbatch: same as Example 2.

[0062] (2) Preparation of PET engineering plastics suitable for extrusion molding: by weight, 46.5 parts of pre-dried PET chips, 5.0 parts of pre-dried PBT chips, 16.5 parts of toughened composite masterbatch, 0.63 parts of Surlyn-8920, 0.32 parts of a mixture of antioxidant 1010 and antioxidant 168 (by mass ratio of 1:1), 0.75 parts of anti-ultraviolet absorber UV380 and 0.3 parts of silane coupling agent KH-550 were put into a high-speed mixer and stirred and mixed. The speed was 350 rpm, the stirring time was 8 min, and the material was discharged into a parallel co-rotating twin-screw extruder with a length-diameter ratio of 48:1 after module arrangement. 30 parts of 2400 tex and 4800 tex long glass fiber winding yarns were added from the exhaust hole of the twin-screw extruder according to the length ratio (1:1). The melt extrusion temperature was 190-245 ° C, the screw speed was 415 rpm, and the water-cooled drawing was granulated to obtain glass fiber (GF) and oyster shell powder @SiO suitable for extrusion molding process. 2 Micro-nano functional powder toughened composite masterbatch reinforces and toughens PET engineering plastics.

[0063] Example 4

[0064] A method for preparing reinforced and toughened PET engineering plastics suitable for plastic extrusion molding:

[0065] (1) Oyster shell powder@SiO 2 Preparation of inorganic micro-nano toughened composite masterbatch: same as Example 2.

[0066] (2) Preparation of PET engineering plastics suitable for extrusion molding: by weight, 44.25 parts of pre-dried PET chips, 4.5 parts of pre-dried PBT chips, 19 parts of toughened composite masterbatch, 0.6 parts of Surlyn-8920, 0.35 parts of a mixture of antioxidant 1010 and antioxidant 168 (by mass ratio of 1:1), 1.0 parts of anti-ultraviolet absorber UV380 and 0.3 parts of silane coupling agent KH-550 were put into a high-speed mixer and stirred at a mixing speed of 100 rpm. The material was discharged into a parallel co-rotating twin-screw extruder with a length-diameter ratio of 48:1 and arranged in a module. 30 parts of 2400 tex and 4800 tex long glass fiber winding yarns were added from the exhaust hole of the twin-screw extruder according to a length ratio of (1:1). The melt extrusion temperature was 190-245°C, the screw speed was 415 rpm, and the water-cooled drawing was granulated to obtain glass fiber (GF) and oyster shell powder @SiO suitable for extrusion molding process. 2Micro-nano functional powder toughened composite masterbatch reinforces and toughens PET engineering plastics.

[0067] Comparative Example 1

[0068] Preparation of reinforced PET engineering plastics: 62 parts of pre-dried PET chips, 6.0 parts of pre-dried PBT chips, 0.85 parts of Surlyn-8920, 0.35 parts of a mixture of antioxidant 1010 and antioxidant 168 (by mass ratio of 1:1), 0.5 parts of an anti-ultraviolet absorber UV380 and 0.3 parts of a silane coupling agent KH-550 were put into a high-speed mixer, the stirring speed was 350 rpm, the stirring time was 8 minutes, and the material was discharged and moved to a parallel co-rotating twin-screw extruder with an aspect ratio of 48:1 arranged by modules, 30 parts of 2400 tex and 4800 tex long glass fiber winding yarns were added from the exhaust hole of the twin-screw extruder in a ratio of 1:1, the melt extrusion temperature was 190-245°C, the screw speed was 415 rpm, and the water-cooled strands were granulated to obtain glass fiber (GF) and oyster shell powder @SiO suitable for extrusion molding process. 2 Micro-nano functional powder toughened composite masterbatch reinforces and toughens PET engineering plastics.

[0069] Comparative Example 2

[0070] Preparation of reinforced PET engineering plastics: 67.45 parts of pre-dried PET chips, 0.9 parts of Surlyn-8920, 0.35 parts of a mixture of antioxidant 1010 and antioxidant 168 (by mass ratio of 1:1), 1.0 parts of an anti-ultraviolet absorber UV380 and 0.3 parts of a silane coupling agent KH-550 were put into a high-speed mixer, the stirring speed was 350 rpm, the stirring time was 8 minutes, and the material was discharged and moved to a parallel co-rotating twin-screw extruder with an aspect ratio of 48:1 arranged by modules. 30 parts of 2400 tex and 4800 tex long glass fiber winding yarns were added from the exhaust hole of the twin-screw extruder according to a length ratio of 1:1. The melt extrusion temperature was 190-245°C, the screw speed was 415 rpm, and the water-cooled strands were granulated to obtain glass fiber (GF) and oyster shell powder @SiO suitable for extrusion molding process. 2 Micro-nano functional powder toughened composite masterbatch reinforces and toughens PET engineering plastics.

[0071] Performance Testing

[0072] The performance tests were conducted on the PET engineering plastics suitable for extrusion molding obtained in Examples 2-4 and the reinforced PET engineering plastics obtained in Comparative Examples 1-2. The results are shown in Table 1.

[0073] Among them, the tensile properties, flexural strength, flexural modulus and notched impact strength are tested according to GB / T1040.1-2006, GB / T9341-2000 and GB / T1843-1996 respectively; the heat deformation temperature is tested according to ASTM-D648, the load condition is 1.86MPa, and the heating rate is 50℃ / min; the melt flow rate (MFR) is tested according to GB / T3682-2000, the set temperature is 260℃, the weight is 2.16kg, and the preheating time is 3min.

[0074] Table 1 Performance test results of Examples 2-4 and Comparative Examples 1-2

[0075]

[0076] It can be seen from Table 1 that, under the premise of fixing the addition amount of glass fiber at 30%, the change in the concentration ratio of the toughened composite masterbatch to the PET slice has a significant impact on the strength and toughness of the PET engineering plastics, as well as the MFR. According to the more suitable process conditions for the material melt flow rate ≤2.0g / 10min of the plastic extrusion molding process, the technical scheme of the present invention can be used to prepare high-strength and high-toughness pipe and rod products suitable for the extrusion molding process.

[0077] The foregoing description of specific exemplary embodiments of the present invention is for the purpose of illustration and demonstration. These descriptions are not intended to limit the present invention to the precise form disclosed, and it is clear that many changes and variations can be made based on the above teachings. The purpose of selecting and describing the exemplary embodiments is to explain the specific principles of the present invention and its practical application, so that those skilled in the art can realize and utilize various different exemplary embodiments of the present invention and various different selections and changes. The scope of the present invention is intended to be limited by the claims and their equivalents.

Claims

1. A method for preparing a reinforced and toughened PET engineering plastic suitable for plastic extrusion molding, characterized in that: The following steps are involved: S1 Preparation of oyster shell powder @ SiO2 inorganic micro-nano toughening composite masterbatch: Put oyster shell powder @ SiO2 inorganic micro-nano functional powder into a mixing device, add a surfactant modifier, a POE-g-GMA grafting compatibilizer and a processing aid, stir and heat, melt-extrude and granulate to obtain a POE-g-GMA (oyster shell powder @ SiO2) toughening composite masterbatch; S2 prepares PET engineering plastics: PET chips, toughened composite masterbatch prepared in S1, PET nucleating agent, PBT crystallization accelerator, alkali-free glass fiber, antioxidant, anti-ultraviolet absorber and coupling agent are blended, melt-extruded and granulated to obtain reinforced and toughened PET engineering plastics suitable for plastic extrusion molding.

2. The method for preparing the reinforced and toughened PET engineering plastics according to claim 1, characterized in that: In step S1, the following components are included by weight: 50 to 90 parts of POE-g-GMA grafted compatibilizer, 10 to 40 parts of oyster shell powder @ SiO2 inorganic micro-nano functional powder, 1.4 to 3.0 parts of surfactant modifier and 1.5 to 5.0 parts of processing aid.

3. The method for preparing the reinforced and toughened PET engineering plastics according to claim 1, characterized in that: In step S1, the oyster shell powder@SiO2 inorganic micro-nano functional powder is prepared by the carbonation method disclosed in Chinese Patent No. 202410174319X using oyster shell powder as a calcium carbonate source, and its SiO2 content is ≤15%, and the CaCO3 content is ≥85%.

4. The method for preparing the reinforced and toughened PET engineering plastics according to claim 1, characterized in that: In step S1, the grafting rate of the POE-g-GMA grafted compatibilizer is 0.8-2.0%, and the melt flow rate is 0.8-3.0 g / 10 min; The surface active modifier includes one or more of stearic acid, aluminate coupling agent, titanate coupling agent and silane coupling agent; The processing aid includes one or more of ethylene bis stearic acid amide, PE wax, polyethylene glycol glycidyl ether, antioxidant, liquid paraffin and dimethyl silicone oil.

5. The method for preparing the reinforced and toughened PET engineering plastics according to claim 1, characterized in that: In step S2, the following components are included in parts by weight: 40 to 65 parts of PET chips, 10 to 20 parts of toughened composite masterbatch prepared in S1, 0.5 to 1.5 parts of PET nucleating agent, 4.5 to 20 parts of PBT crystallization accelerator, 15 to 30 parts of alkali-free glass fiber, 0.1 to 0.5 parts of antioxidant, 0.5 to 2.0 parts of anti-ultraviolet absorber and 0.05 to 0.3 parts of coupling agent.

6. The method for preparing the reinforced and toughened PET engineering plastics according to claim 1, characterized in that: In step S2, the intrinsic viscosity of the PET slice is 0.7-1.2 dl / g, and the water content is ≤0.02%; The PET nucleating agent includes one or more of polytetrafluoroethylene powder, sodium stearate, sodium benzoate, and sodium salt of ethylene-methacrylic acid copolymer; The PBT crystallization accelerator is a PBT slice, the intrinsic viscosity of which is 0.8-1.2 dl / g and the water content is ≤0.02%; The alkali-free glass fiber includes one or two of alkali-free 2400tex and 4800tex long glass fiber winding yarns; The antioxidant includes one or more of antioxidant 1010, antioxidant 168 and antioxidant 215B; The anti-ultraviolet absorber comprises one or more of a composite anti-ultraviolet absorber composed of trimethylolpropane triglycidyl ether and bistrifluoromethanesulfonyl imide, UV3638 and UV380; The coupling agent includes silane coupling agent KH-550.

7. The method for preparing the reinforced and toughened PET engineering plastics according to claim 1, characterized in that: In step S2, the melt extrusion equipment adopts a parallel co-rotating twin-screw extruder with a length-to-diameter ratio of ≥36:1; the melt extrusion temperature is 190-250°C, and the screw speed is 410-420rpm.

8. The method for preparing the reinforced and toughened PET engineering plastics according to claim 1, characterized in that: In step S2, the prepared reinforced and toughened PET engineering plastic suitable for plastic extrusion molding has a tensile strength of up to 120 MPa; a flexural strength of more than 85 MPa; a flexural modulus of more than 4500 MPa; a notched impact strength of more than 18 MPa; a heat deformation temperature of ≥100°C; and a melt flow rate (MFR) of ≤2.0 g / 10 min.

9. The reinforced and toughened PET engineering plastic prepared by the method according to any one of claims 1 to 8.

10. Use of the reinforced and toughened PET engineering plastic prepared by the method according to any one of claims 1 to 8 in the extrusion molding process to prepare pipe and rod products, characterized in that: The extrusion equipment used is a single screw extruder with a length-to-diameter ratio of ≥36:1.

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