High-strength and high-rigidity polar polypropylene composition as well as preparation method and application thereof

Abstract

The invention discloses a polypropylene composition which comprises the following components in parts by weight: 60-80 parts of polypropylene resin containing polar groups, 20-40 parts of cycloolefin copolymer containing polar groups, 0.1-1 part of a free radical scavenger, 0.1-1 part of an antioxidant and 1-5 parts of a lubricant, the two-phase compatibility is increased by introducing a polar group in the preparation process of the polypropylene and cycloolefin copolymer, and the polar polypropylene composition with high rigidity and high strength is prepared by a liquid phase mixing method and can be used for a water pipe of a five-constant system, so that the service life of the material is prolonged.

Description

Technical Field

[0001] The invention relates to the field of polymer material processing and application, and in particular to the preparation of a high-strength and high-rigidity polypropylene composition. Background Art

[0002] The five constant systems are intelligent systems that integrate air conditioning, floor heating, humidification and dehumidification, fresh air, and purification. They are an advanced indoor environment control system. By comprehensively adjusting the indoor temperature, humidity, oxygen content, air cleanliness, and noise level, the indoor environment can be kept constant in temperature, humidity, oxygen, cleanliness, and quietness, creating a comfortable, healthy, and high-quality indoor environment for people. As people's requirements for quality of life continue to increase, this technology will be more widely used and developed in the future.

[0003] The core structure of the five-constant system is a capillary network laid on the roof, walls, and ground. In summer, cold water at 16-19°C is introduced to remove excess heat, and hot water at 32-35°C is introduced in winter to supplement the indoor environment with heat, thereby achieving indoor temperature regulation. Currently, the commonly used PPR pipe capillary diameter is 4.3mm and the wall thickness is 0.8mm. However, in use, PPR pipes show the disadvantages of insufficient strength and rigidity. At present, the industry hopes to improve its shortcomings through the expected blending of cycloolefin copolymers, but the compatibility of the two phases is often poor and the opposite effect is obtained. Summary of the invention

[0004] In order to overcome the deficiencies of the prior art, the object of the present invention is to provide a high-strength, high-rigidity polypropylene composition for five-constant system water pipes, by blending cyclic olefin copolymers into polypropylene under high temperature and high rotation speed conditions to prepare a high-strength, high-rigidity polypropylene composition.

[0005] The present invention adopts the following technical solutions:

[0006] The first aspect of the present invention provides a high-strength, high-rigidity polypropylene composition, the composition comprising the following components:

[0007] 60-80 parts by weight of a polypropylene resin containing a polar group, 20-40 parts by weight of a cycloolefin copolymer containing a polar group, 0.1-1 parts by weight of a free radical scavenger, 0.1-1 parts by weight of an antioxidant, and 1-5 parts by weight of a lubricant.

[0008] Furthermore, the polypropylene resin containing polar groups is a copolymer of propylene and a propylene derivative containing polar groups;

[0009] Furthermore, the preparation method of the polypropylene resin containing polar groups is as follows: a solvent, propylene, a polar third monomer, and a catalyst are continuously introduced into a reaction kettle, and when the reaction starts, when polymer accumulates in a flash tank, a twin-screw extruder and a melt pump are turned on to transport the polymer to the extruder for strand granulation to obtain polypropylene particles containing the polar third monomer;

[0010] Further, preferably, the solvent feed amount is 0.9 to 5.0 L / h, the propylene feed amount is 450 to 1000 g / h, the polar third monomer feed amount is 150 to 1500 ml / h, the catalyst feed amount is 200 to 500 ml / h, the co-catalyst feed amount is 150 to 1250 ml / h, and the residence time is 10 to 20 min;

[0011] Further, preferably, the reaction temperature is 50 to 90°C, more preferably 60 to 80°C;

[0012] Further, preferably, the polar group-containing acrylic derivative is an ester of acrylic acid and its homologues, more preferably one or more of methyl acrylate, ethyl acrylate and methyl 2-methacrylate.

[0013] Further, preferably, the ratio of propylene to the polar group-containing propylene derivative is 1 to 10 mol%;

[0014] Further, preferably, the solvent used to prepare the polypropylene resin containing polar groups is one or more of benzene series, cycloalkanes and their derivatives, more preferably, one or more of toluene and cyclohexane;

[0015] Further, preferably, the catalyst is a typical Ziegler-Netta catalyst, more preferably titanium tetrachloride-triethylaluminum [TiCl 4 -Al(C 2 H 5 ) 3 ];

[0016] Further, preferably, the molar ratio of triethylaluminum to titanium tetrachloride is 100-500.

[0017] Furthermore, the polar group-containing cycloolefin copolymer is a copolymer of α-olefin, cycloolefin and a polar third monomer;

[0018] Furthermore, the preparation method of the cycloolefin copolymer containing polar groups is as follows: a solvent, a cycloolefin, an α-olefin, a polar third monomer, a catalyst, and a co-catalyst are continuously introduced into a reaction kettle, and when the reaction starts, when polymer accumulates in a flash tank, a twin-screw extruder and a melt pump are turned on to convey the polymer to the extruder for strand granulation to obtain cycloolefin copolymer particles containing a polar third monomer;

[0019] Further, preferably, the solvent feed amount is 0.4-2.0 L / h, the cycloolefin feed amount is 1.9-5.2 L / h, the α-olefin feed amount is 100-300 g / h, the polar third monomer feed amount is 50-400 ml / h, the catalyst feed amount is 250-600 ml / h, the co-catalyst feed amount is 150-1000 ml / h, and the residence time is 6-15 min;

[0020] Preferably, the α-olefin is one or both of ethylene and propylene, more preferably ethylene;

[0021] Further, preferably, the cycloolefin is one or more of norbornene, tetracyclododecene, dicyclopentadiene and derivatives thereof, more preferably norbornene or tetracyclododecene;

[0022] Further, preferably, the polar third monomer is an acrylate derivative containing a polar group, which is an ester of acrylic acid and its homologues, preferably one or more of methyl acrylate, ethyl acrylate, and methyl 2-methacrylate, more preferably methyl acrylate;

[0023] Further, preferably, the reaction temperature is 70 to 180°C, more preferably 120 to 160°C;

[0024] Further, preferably, the solvent used to prepare the cycloolefin copolymer containing polar groups is one or more of benzene series, cycloalkanes and their derivatives, more preferably, one or more of toluene and cyclohexane;

[0025] Further, preferably, the cocatalyst used in preparing the cycloolefin copolymer is an alkylaluminoxane, more preferably methylaluminoxane;

[0026] Further, preferably, the main catalyst used to prepare the cycloolefin copolymer is a metallocene catalyst, more preferably one or more of a titanocene metal catalyst and a zirconocene metal catalyst;

[0027] Further, preferably, the molar ratio of the co-catalyst to the catalyst is 100 / 1 to 500 / 1;

[0028] Furthermore, preferably, in the preparation process of the cycloolefin copolymer, the feed mass ratio of α-olefin to cycloolefin is 7 / 1 to 18 / 1, and the feed amount of the polar third monomer is 1 mol% to 10 mol% of the feed amount of the α-olefin;

[0029] Further, preferably, the free radical scavenger is one or more of 2,2,6,6-tetramethylpiperidinyl oxide (TEMPO) and 1,2-diphenylethylene (DPE);

[0030] Further, preferably, the antioxidant is one or more of Irganox PS800, antioxidant 1010, and antioxidant 168, preferably a mixture of antioxidant 1010 and antioxidant 168 in proportion;

[0031] Further, preferably, the mass ratio of antioxidant 1010 to antioxidant 168 is 1.5 / 1 to 2.5 / 1;

[0032] Further, preferably, the lubricant is one or more of polyethylene wax and magnesium stearate.

[0033] The second aspect of the present invention provides a method for preparing the above-mentioned polypropylene composition, comprising the following steps:

[0034] Respectively take corresponding amounts of polypropylene containing polar groups, cycloolefin copolymer containing polar groups, free radical scavenger, antioxidant and lubricant, mix them evenly and immerse them in a sufficient amount of solvent, heat them to 220-240° C. after dissolving, turn on the melt pump to transport the solution to a flash tank at a flow rate of 10-20 ml / min for flash evaporation to obtain a polypropylene and cycloolefin copolymer composition, turn on the melt pump of the flash tank to transport the composition to an extruder at a rate of 10-20 g / min for strand granulation to obtain a polypropylene composition.

[0035] Preferably, the extrusion temperature of the extruder is 190-220° C.; the screw speed is 100-300 rpm.

[0036] Further, preferably, the extruder temperature is set as: 190-200°C in zone 1, 200-210°C in zones 2-3, 200-210°C in zones 4-6, 215-220°C in zones 7-10, 215-220°C in zones 11-12, and 200-210°C in zone 13.

[0037] According to another aspect of the present invention, the composition is prepared by extrusion molding to prepare a pipe with a diameter of 3 to 5 mm and a wall thickness of 0.5 to 1.0 mm, which can be used for a five-constant system water pipe.

[0038] The polypropylene composition provided by the present invention has the following advantages compared with the prior art:

[0039] The polypropylene composition provided by the present invention has the characteristics of high strength and high rigidity. The addition of a polar third monomer increases the compatibility of the two phases. The cost is controllable, the preparation process is relatively stable, the process is simple, and the service life of the water pipes of the five-constant system can be effectively improved, and the composition has potential application value. DETAILED DESCRIPTION

[0040] The raw materials used in the present invention are as follows:

[0041] Methylaluminoxane and triethylaluminum were purchased from GRACE;

[0042] Toluene was purchased from Komiou Chemical Reagent Co., Ltd. with a purity of ≥99.0%;

[0043] Methylcyclohexane was purchased from Beijing Inokai Technology Co., Ltd. with a purity of ≥99.0%;

[0044] Cyclohexane was purchased from Beijing Inokai Technology Co., Ltd. with a purity of ≥99.0%;

[0045] Dizirconocene dichloride and ferrocene were purchased from Beijing Inokai Technology Co., Ltd. with a purity of ≥99.9%;

[0046] TiCl4 was purchased from Beijing Inokai Technology Co., Ltd. with a purity of ≥99.9%;

[0047] Norbornene, tetracyclododecene, and dicyclopentadiene were purchased from Beijing Inokai Technology Co., Ltd. with a purity of ≥99.9%;

[0048] Ethylene and propylene were purchased from Qingdao Air Liquide Co., Ltd. with a purity of ≥99.0%;

[0049] Methyl acrylate, ethyl acrylate, and ethyl 2-methacrylate were purchased from Beijing Inokai Technology Co., Ltd. with a purity of ≥99.9%;

[0050] Antioxidants 1010 and 168 were purchased from Tianjin Lianlong New Materials Co., Ltd.;

[0051] Polyethylene wax was purchased from Qingdao Sino Company;

[0052] Magnesium stearate was purchased from Shandong Baolilai Company;

[0053] 2,2,6,6-Tetramethylpiperidinyl oxide (TEMPO) was purchased from Aladdin Chemical Reagent Co., Ltd. with a purity of ≥99.0%;

[0054] The processing and analysis characterization equipment information and test standards of the present invention are as follows:

[0055] Twin-screw extruder, Nippon Steel 22-B2N19110CW C11;

[0056] Tensile testing machine, High Speed ​​Rail (Dongguan) Company AL-7000S1;

[0057] The tensile strength and elastic modulus test standards are GB / T 36264-2018 and GB / T 1040-2006.

[0058] The present invention is further described in conjunction with the following specific examples, but the present invention is not limited to the listed examples, and also includes all any known changes within the scope of the claims of the present invention.

[0059] Prepare in advance sufficient amounts of 1.34 umol / ml dichlorozirconocene or ferrocene toluene solution, 0.2 mmol / ml methylaluminoxane toluene solution, 1.5 umol / ml TiCl 4 Toluene solution, 0.2mmol / ml triethylaluminum toluene solution, 7.8mol / L norbornene toluene solution, 7mol / L dicyclopentadiene toluene solution, 1mol / L methyl acrylate or ethyl acrylate or 2-ethyl methacrylate toluene solution are placed in corresponding storage tanks for use.

[0060] Example 1

[0061] Turn on the oil bath heating of the cycloolefin copolymer continuous reaction device, turn on the toluene, tetracyclododecene and methyl acrylate feed pumps, when the reaction system pressure rises to 3MPa, adjust the toluene feed rate to 1.52L / h, the tetracyclododecene feed rate to 1.96L / h, the methyl acrylate feed rate to 51ml / h, turn on the ethylene flow controller, and adjust the ethylene feed rate to 143g / h. When the temperature of the reactor rises to 120°C, turn on the dichlorozirconocene and methylaluminoxane feed pumps, and adjust the feed rates to 281ml / h and 188ml / h respectively. The reaction begins. When polymer accumulates in the flash tank, turn on the twin-screw extruder and melt pump in turn, and transport the polymer to the twin-screw extruder for strand granulation to obtain polar cycloolefin copolymer particles;

[0062] Turn on the oil bath heating of the polypropylene continuous reaction device, turn on the toluene and methyl acrylate feed pumps, adjust the toluene feed rate to 4.92L / h, the methyl acrylate feed rate to 221ml / h, turn on the propylene flow controller, adjust the propylene feed rate to 924g / h, and turn on the TiCl 4 and triethylaluminum feed pump, adjusting the feed rates to 500ml / h and 375ml / h respectively. When the reaction starts and polymer accumulates in the flash tank, the twin-screw extruder and melt pump are opened successively to transport the polymer to the twin-screw extruder for strand granulation to obtain polar polypropylene resin;

[0063] Take 3.0 kg of the above-mentioned polypropylene particles and 2.0 kg of the above-mentioned cycloolefin copolymer particles, 5 g of antioxidant 1010, 5 g of TEMPO, and 50 g of polyethylene wax, mix them evenly, place them in an oil bath heated pressure-resistant material kettle, add 25 kg of toluene, turn on the oil bath and heat to 220°C, turn on the stirring to mix thoroughly, turn on the flash tank and heat the oil bath to above 260°C, then turn on the pump to pump the mixed liquid into the flash tank at a rate of 10 ml / min for flash evaporation, and then turn on the melt pump to transport the polymer to the extruder at a rate of 10 g / min to produce polypropylene and cycloolefin polymer composition particles containing polar groups for strand granulation, and prepare samples of the composition for tensile strength and elastic modulus tests.

[0064] Example 2

[0065] Turn on the oil bath heating of the cycloolefin copolymer continuous reaction device, turn on the toluene, tetracyclododecene and ethyl acrylate feed pumps, when the reaction system pressure rises to 3MPa, adjust the toluene feed rate to 1.14L / h, the tetracyclododecene feed rate to 1.96L / h, the ethyl acrylate feed rate to 55ml / h, turn on the ethylene flow controller, and adjust the ethylene feed rate to 154g / h. When the temperature of the reactor rises to 120°C, turn on the dichlorozirconocene and methylaluminoxane feed pumps, and adjust the feed rates to 281ml / h and 564ml / h respectively. The reaction begins. When polymer accumulates in the flash tank, turn on the twin-screw extruder and melt pump in turn, and transport the polymer to the twin-screw extruder for strand granulation to obtain polar cycloolefin copolymer particles;

[0066] Turn on the oil bath heating of the polypropylene continuous reaction device, turn on the toluene and ethyl acrylate feed pumps, adjust the toluene feed rate to 3.21L / h, the ethyl acrylate feed rate to 147ml / h, turn on the propylene flow controller, adjust the propylene feed rate to 616g / h, and turn on the TiCl 4 and triethylaluminum feed pump, adjusting the feed rates to 200 ml / h and 450 ml / h respectively. When the reaction starts, the twin-screw extruder and melt pump are turned on successively to convey the polymer to the twin-screw extruder for strand granulation to obtain polar polypropylene resin.

[0067] Take 3.5 kg of the above-mentioned polypropylene particles and 1.5 kg of the above-mentioned cycloolefin copolymer particles, mix them evenly with 25 g of antioxidant 1010, 25 g of TEMPO, and 150 g of polyethylene wax, place them in an oil bath heated pressure-resistant material kettle, add 25 kg of toluene, turn on the oil bath and heat to 230°C, turn on the stirring to mix thoroughly, turn on the flash tank and heat the oil bath to above 260°C, then turn on the pump to pump the mixed solution into the flash tank at a rate of 10 ml / min for flash evaporation, and then turn on the melt pump to transport the polymer to the extruder at a rate of 10 g / min to obtain polypropylene and cycloolefin polymer composition particles containing polar groups for strand granulation, and prepare samples of the composition for tensile strength and elastic modulus tests.

[0068] Example 3

[0069] Turn on the oil bath heating of the cycloolefin copolymer continuous reaction device, turn on the methylcyclohexane, tetracyclododecene and methyl acrylate feed pumps, when the reaction system pressure rises to 3MPa, adjust the methylcyclohexane feed rate to 0.43L / h, the tetracyclododecene feed rate to 1.96L / h, the methyl acrylate feed rate to 397ml / h, turn on the ethylene flow controller, and adjust the ethylene feed rate to 222g / h. When the temperature of the reactor rises to 140°C, turn on the dichlorozirconocene and methylaluminoxane feed pumps, and adjust the feed rates to 281ml / h and 940ml / h respectively. The reaction begins. When polymer accumulates in the flash tank, turn on the twin-screw extruder and melt pump in turn, and transport the polymer to the twin-screw extruder for strand granulation to obtain polar cycloolefin copolymer particles;

[0070] Turn on the oil bath heating of the polypropylene continuous reaction device, turn on the methylcyclohexane and methyl acrylate feed pumps, adjust the methylcyclohexane feed rate to 2.68L / h, the methyl acrylate feed rate to 734ml / h, turn on the propylene flow controller, adjust the propylene feed rate to 616g / h, and turn on the TiCl 4 and triethylaluminum feed pump, adjusting the feed rates to 333 ml / h and 250 ml / h respectively. When the reaction starts and polymer accumulates in the flash tank, the twin-screw extruder and melt pump are opened successively to transport the polymer to the twin-screw extruder for strand granulation to obtain polar polypropylene resin.

[0071] Take 3.5 kg of the above-mentioned polypropylene particles and 1.5 kg of the above-mentioned cycloolefin copolymer particles, 30 g of antioxidant 1010, 20 g of antioxidant 168, 25 g of TEMPO, and 150 g of polyethylene wax, mix them evenly, place them in an oil bath heated pressure-resistant material kettle, add 25 kg of methylcyclohexane, turn on the oil bath and heat to 240 degrees Celsius, turn on the stirring to mix thoroughly, turn on the flash tank and heat the oil bath to above 270°C, then turn on the pump to pump the mixed solution into the flash tank at a rate of 10 ml / min for flash evaporation, and then turn on the melt pump to transport the polymer to the extruder at a rate of 10 g / min to obtain polypropylene and cycloolefin polymer composition particles containing polar groups for strand granulation, and prepare samples of the composition for tensile strength and elastic modulus tests.

[0072] Example 4

[0073] Turn on the oil bath heating of the cycloolefin copolymer continuous reaction device, turn on the cyclohexane, norbornene and methyl acrylate feed pumps, when the reaction system pressure rises to 3MPa, adjust the cyclohexane feed rate to 4.09L / h, norbornene feed rate to 5.12L / h, methyl acrylate feed rate to 320ml / h, turn on the propylene flow controller, and adjust the propylene feed rate to 269g / h. When the temperature of the reactor rises to 120°C, turn on the titanocene and methylaluminoxane feed pumps, and adjust the feed rates to 281ml / h and 188ml / h respectively. The reaction begins. When polymer accumulates in the flash tank, turn on the twin-screw extruder and melt pump in turn, and transport the polymer to the twin-screw extruder for strand granulation to obtain polar cycloolefin copolymer particles;

[0074] Turn on the oil bath heating of the polypropylene continuous reaction device, turn on the cyclohexane and methyl acrylate feed pumps, adjust the cyclohexane feed rate to 2.56L / h, the methyl acrylate feed rate to 734ml / h, turn on the propylene flow controller, adjust the propylene feed rate to 616g / h, and turn on the TiCl 4 and triethylaluminum feed pump, adjusting the feed rates to 400ml / h and 300ml / h respectively. When the reaction starts and polymer accumulates in the flash tank, the twin-screw extruder and melt pump are opened successively to transport the polymer to the twin-screw extruder for strand granulation to obtain polar polypropylene resin;

[0075] Take 4.0 kg of the above-mentioned polypropylene particles and 1.0 kg of the above-mentioned cycloolefin copolymer particles, 33.3 g of antioxidant 1010, 16.7 g of antioxidant 168, 50 g of TEMPO, and 250 g of polyethylene wax, mix them evenly, place them in an oil bath heated pressure-resistant material kettle, add 25 kg of cyclohexane, turn on the oil bath and heat to 240°C, turn on the stirring to mix thoroughly, turn on the flash tank and heat the oil bath to above 280°C, then turn on the pump to pump the mixed solution into the flash tank at a rate of 15 ml / min for flash evaporation, and then turn on the melt pump to transport the polymer to the extruder at a rate of 15 g / min to obtain polypropylene and cycloolefin polymer composition particles containing polar groups, and prepare samples of the composition for tensile strength and elastic modulus tests.

[0076] Example 5

[0077] Turn on the oil bath heating of the cycloolefin copolymer continuous reaction device, turn on the cyclohexane, tetracyclododecene and methyl acrylate feed pumps, when the reaction system pressure rises to 3MPa, adjust the cyclohexane feed rate to 0.94L / h, the tetracyclododecene feed rate to 1.96L / h, the methyl acrylate feed rate to 396ml / h, turn on the ethylene flow controller, and adjust the ethylene feed rate to 111g / h. When the temperature of the reactor rises to 160°C, turn on the titanocene and methylaluminoxane feed pumps, and adjust the feed rates to 422ml / h and 282ml / h respectively. The reaction begins. When polymer accumulates in the flash tank, turn on the twin-screw extruder and melt pump in turn, and transport the polymer to the twin-screw extruder for strand granulation to obtain polar cycloolefin copolymer particles;

[0078] Turn on the oil bath heating of the polypropylene continuous reaction device, turn on the cyclohexane and methyl acrylate feed pumps, adjust the cyclohexane feed rate to 0.95L / h, the methyl acrylate feed rate to 1467ml / h, turn on the propylene flow controller, adjust the propylene feed rate to 616g / h, and turn on the TiCl 4 and triethylaluminum feed pump, adjusting the feed rates to 333 ml / h and 1250 ml / h respectively. When the reaction starts and polymer accumulates in the flash tank, the twin-screw extruder and melt pump are opened successively to transport the polymer to the twin-screw extruder for strand granulation to obtain polar polypropylene resin;

[0079] Take 3.0 kg of the above-mentioned polypropylene particles and 2.0 kg of the above-mentioned cycloolefin copolymer particles, 35.7 g of antioxidant 1010, 14.3 g of antioxidant 168, 50 g of TEMPO, and 150 g of polyethylene wax, mix them evenly, place them in an oil bath heated pressure-resistant material kettle, add 25 kg of cyclohexane, turn on the oil bath and heat to 240°C, turn on the stirring to mix thoroughly, turn on the flash tank and heat the oil bath to above 280°C, then turn on the pump to pump the mixed solution into the flash tank at a rate of 20 ml / min for flash evaporation, and then turn on the melt pump to transport the polymer to the extruder at a rate of 20 g / min to obtain polypropylene and cycloolefin polymer composition particles containing polar groups for strand granulation, and prepare samples of the composition for tensile strength and elastic modulus tests.

[0080] Example 6

[0081] Turn on the oil bath heating of the cycloolefin copolymer continuous reaction device, turn on the toluene, dicyclopentadiene and 2-ethyl methacrylate feed pumps, when the reaction system pressure rises to 3MPa, adjust the toluene feed rate to 2.0L / h, the dicyclopentadiene feed rate to 3.34L / h, and the 2-ethyl methacrylate feed rate to 393ml / h, turn on the ethylene flow controller, and adjust the ethylene feed rate to 220g / h. When the temperature of the reactor rises to 120°C, turn on the dichlorozirconocene and methylaluminoxane feed pumps, and adjust the feed rates to 562ml / h and 376ml / h respectively. The reaction begins. When polymer accumulates in the flash tank, turn on the twin-screw extruder and melt pump in turn, and transport the polymer to the twin-screw extruder for strand granulation to obtain polar cycloolefin copolymer particles;

[0082] Turn on the oil bath heating of the polypropylene continuous reaction device, turn on the toluene and 2-ethyl methacrylate feed pumps, adjust the toluene feed rate to 2.01L / h, the 2-ethyl methacrylate feed rate to 551ml / h, turn on the propylene flow controller, adjust the propylene feed rate to 462g / h, and turn on the TiCl 4 and triethylaluminum feed pump, adjusting the feed rates to 250ml / h and 188ml / h respectively. When the reaction starts and polymer accumulates in the flash tank, the twin-screw extruder and melt pump are opened successively to transport the polymer to the twin-screw extruder for strand granulation to obtain polar polypropylene resin;

[0083] 3.5 kg of the above-mentioned polypropylene particles and 1.5 kg of the above-mentioned cycloolefin copolymer particles are mixed with 33.3 g of antioxidant 1010, 16.7 g of antioxidant 168, 50 g of TEMPO, and 150 g of magnesium stearate, and then placed in an oil bath heated pressure-resistant material kettle and added with 25 kg of toluene. The oil bath is turned on and heated to 220° C. The stirring is turned on to mix thoroughly. The flash tank is turned on and the oil bath is heated to above 260° C. Then the pump is turned on to pump the mixed solution into the flash tank at a rate of 10 ml / min for flash evaporation. The melt pump is then turned on to transport the polymer to the extruder at a rate of 10 g / min to obtain the polypropylene and cycloolefin polymer composition particles containing polar groups for strand granulation. The composition is sampled and tested for tensile strength and elastic modulus.

[0084] Comparative Example 1

[0085] Turn on the oil bath heating of the cycloolefin copolymer continuous reaction device, turn on the toluene and tetracyclododecene feed pumps, when the pressure of the reaction system rises to 3MPa, adjust the toluene feed rate to 1.14L / h, the tetracyclododecene feed rate to 1.96L / h, turn on the ethylene flow controller, and adjust the ethylene feed rate to 154g / h. When the temperature of the reactor rises to 120°C, turn on the dichlorozirconocene and methylaluminoxane feed pumps, and adjust the feed rates to 281ml / h and 564ml / h respectively. The reaction begins, and when polymer accumulates in the flash tank, turn on the twin-screw extruder and melt pump in turn, and transport the polymer to the twin-screw extruder for strand granulation to obtain polar cycloolefin copolymer particles;

[0086] Turn on the oil bath heating of the polypropylene continuous reaction device, turn on the toluene feed pump, adjust the toluene feed rate to 3.21L / h, turn on the propylene flow controller, adjust the propylene feed rate to 616g / h, and turn on the TiCl 4 and triethylaluminum feed pump, adjusting the feed rates to 200ml / h and 450ml / h respectively. When the reaction starts and polymer accumulates in the flash tank, the twin-screw extruder and melt pump are opened successively to transport the polymer to the twin-screw extruder for strand granulation to obtain polar polypropylene resin.

[0087] Take 3.5 kg of the above-mentioned polypropylene particles and 1.5 kg of the above-mentioned cycloolefin copolymer particles, mix them evenly with 25 g of antioxidant 1010, 25 g of TEMPO, and 150 g of polyethylene wax, place them in an oil bath heated pressure-resistant material kettle, add 25 kg of toluene, turn on the oil bath and heat to 230 degrees Celsius, turn on the stirring to mix thoroughly, turn on the flash tank and heat the oil bath to above 260°C, then turn on the pump to pump the mixed solution into the flash tank at a rate of 10 ml / min for flash evaporation, and then turn on the melt pump to transport the polymer to the extruder at a rate of 10 g / min to obtain polypropylene and cycloolefin polymer composition particles containing polar groups for strand granulation, and prepare samples of the composition for tensile strength and elastic modulus tests.

[0088] Comparative Example 2

[0089] Turn on the oil bath heating of the cycloolefin copolymer continuous reaction device, turn on the methylcyclohexane and tetracyclododecene feed pumps, when the reaction system pressure rises to 3MPa, adjust the methylcyclohexane feed rate to 0.43L / h, the tetracyclododecene feed rate to 1.96L / h, turn on the ethylene flow controller, and adjust the ethylene feed rate to 222g / h. When the temperature of the reactor rises to 140°C, turn on the dichlorozirconocene and methylaluminoxane feed pumps, and adjust the feed rates to 397ml / h and 281ml / h respectively. The reaction begins, and when polymer accumulates in the flash tank, turn on the twin-screw extruder and melt pump in turn, and transport the polymer to the twin-screw extruder for strand granulation to obtain polar cycloolefin copolymer particles;

[0090] Turn on the oil bath heating of the polypropylene continuous reaction device, turn on the methylcyclohexane and methyl acrylate feed pumps, adjust the methylcyclohexane feed rate to 2.68L / h, the methyl acrylate feed rate to 734ml / h, turn on the propylene flow controller, adjust the propylene feed rate to 616g / h, and turn on the TiCl 4 and triethylaluminum feed pump, adjusting the feed rates to 333 ml / h and 250 ml / h respectively. When the reaction starts and polymer accumulates in the flash tank, the twin-screw extruder and melt pump are opened successively to transport the polymer to the twin-screw extruder for strand granulation to obtain polar polypropylene resin.

[0091] Take 3.5 kg of the above-mentioned polypropylene particles and 1.5 kg of the above-mentioned cycloolefin copolymer particles, 30 g of antioxidant 1010, 20 g of antioxidant 168, 25 g of TEMPO, and 150 g of polyethylene wax, mix them evenly, place them in an oil bath heated pressure-resistant material kettle, add 25 kg of methylcyclohexane, turn on the oil bath and heat to 240 degrees Celsius, turn on the stirring to mix thoroughly, turn on the flash tank and heat the oil bath to above 270°C, then turn on the pump to pump the mixed solution into the flash tank at a rate of 10 ml / min for flash evaporation, and then turn on the melt pump to transport the polymer to the extruder at a rate of 10 g / min to obtain polypropylene and cycloolefin polymer composition particles containing polar groups for strand granulation, and prepare samples of the composition for tensile strength and elastic modulus tests.

[0092] The product of this embodiment is tested for performance using the national standard, and the results are shown in Table 1:

[0093] Table 1 Test results of embodiments and comparative examples

[0094]

[0095] It can be concluded from the test results that the addition of a polar third monomer can effectively improve the compatibility of the two phases, and the effect becomes more significant as the amount of the polar third monomer added increases, while the opposite effect is exhibited when only one phase is added with the polar third monomer; the method provided by the present invention can significantly improve the rigidity and strength of the polypropylene and cycloolefin copolymer composition.

Claims

1. A high-strength, high-rigidity polypropylene composition, the composition comprising the following components: 60-80 parts by weight of a polypropylene resin containing polar groups, 20-40 parts by weight of a cycloolefin copolymer containing polar groups, 0.1-1 parts by weight of a free radical scavenger, 0.1-1 parts by weight of an antioxidant, and 1-5 parts by weight of a lubricant; the polypropylene resin containing polar groups is a copolymer of propylene and a propylene derivative containing polar groups; the preparation method of the polypropylene resin containing polar groups is as follows: continuously introducing a solvent, propylene, a polar third monomer, and a catalyst into a reaction kettle, starting a reaction, and when polymers accumulate in a flash tank, opening a twin-screw extruder and a melt pump, conveying the polymers to the extruder for stranding and granulation, and obtaining polypropylene particles containing a polar third monomer.

2. The polypropylene composition according to claim 1, characterized in that The solvent feed rate is 0.9-5.0 L / h, the propylene feed rate is 450-1000 g / h, the polar third monomer feed rate is 150-1500 ml / h, the catalyst feed rate is 200-500 ml / h, the co-catalyst feed rate is 150-1250 ml / h, the residence time is 10-20 min; and / or the reaction temperature is 50-90° C., more preferably 60-80° C.

3. The polypropylene composition according to claim 1 or 2, characterized in that The polar group-containing propenyl derivative is an ester of acrylic acid and its homologues, more preferably one or more of methyl acrylate, ethyl acrylate, and methyl 2-methacrylate; and / or, the ratio of propene to the polar group-containing propenyl derivative is 1 to 10 mol%; the catalyst is a typical Ziegler-Netta catalyst, more preferably titanium tetrachloride-triethylaluminum [TiCl4-Al(C2H5)3]; preferably, the molar ratio of triethylaluminum to titanium tetrachloride is 100 to 500.

4. The polypropylene composition according to any one of claims 1 to 3, characterized in that The polar group-containing cycloolefin copolymer is a copolymer of α-olefin, cycloolefin and a polar third monomer; the preparation method of the polar group-containing cycloolefin copolymer is: continuously introducing a solvent, cycloolefin, α-olefin, a polar third monomer, a catalyst and a co-catalyst into a reaction kettle, starting the reaction, and when polymer accumulates in a flash tank, turning on a twin-screw extruder and a melt pump, conveying the polymer to the extruder for strand granulation, and obtaining cycloolefin copolymer particles containing a polar third monomer.

5. The polypropylene composition according to claim 4, characterized in that The solvent feed rate is 0.4-2.0 L / h, the cycloolefin feed rate is 1.9-5.2 L / h, the α-olefin feed rate is 100-300 g / h, the polar third monomer feed rate is 50-400 ml / h, the catalyst feed rate is 250-600 ml / h, the co-catalyst feed rate is 150-1000 ml / h, and the residence time is 6-15 min.

6. The polypropylene composition according to claim 4 or 5, characterized in that The α-olefin is one or both of ethylene and propylene, more preferably ethylene; and / or the cycloolefin is one or more of norbornene, tetracyclododecene, dicyclopentadiene and their derivatives, more preferably norbornene or tetracyclododecene; and / or the polar third monomer is a propenyl derivative containing a polar group, which is an ester of acrylic acid and its homologues, preferably one or more of methyl acrylate, ethyl acrylate, and methyl 2-methacrylate, more preferably methyl acrylate.

7. The polypropylene composition according to any one of claims 4 to 6, characterized in that The co-catalyst used in preparing the cycloolefin copolymer is an alkylaluminoxane, more preferably methylaluminoxane; and / or, the main catalyst used in preparing the cycloolefin copolymer is a metallocene catalyst, more preferably one or more of a titanocene metal catalyst and a zirconocene metal catalyst; and / or, the molar ratio of the co-catalyst to the catalyst is 100 / 1 to 500 / 1; and / or, in the preparation process of the cycloolefin copolymer, the feed mass ratio of α-olefin to cycloolefin is 7 / 1 to 18 / 1, and the feed amount of the polar third monomer is 1 mol% to 10 mol% of the feed amount of the α-olefin; and / or, the reaction temperature is 70 to 180°C, more preferably 120 to 160°C.

8. The method for preparing the polypropylene composition according to any one of claims 1 to 7, characterized in that: The following steps are involved: Respectively take corresponding amounts of polypropylene containing polar groups, cycloolefin copolymer containing polar groups, free radical scavenger, antioxidant and lubricant, mix them evenly and immerse them in a sufficient amount of solvent, heat them to 220-240° C. after dissolving, turn on the melt pump to transport the solution to a flash tank at a flow rate of 10-20 ml / min for flash evaporation to obtain a polypropylene and cycloolefin copolymer composition, turn on the melt pump of the flash tank to transport the composition to an extruder at a rate of 10-20 g / min for strand granulation to obtain a polypropylene composition.

9. The preparation method according to claim 8, characterized in that: The extrusion temperature of the extruder is 190-220°C; the screw speed is 100-300rpm.

10. Use of the polypropylene composition according to any one of claims 1 to 7 or the polypropylene composition prepared by the preparation method according to claim 8 or 9 in water pipes of a five-constant system.

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