A polypropylene composite material and preparation method thereof

Abstract

The present invention relates to a polypropylene composite material and a preparation method thereof. The polypropylene composite material comprises, by weight, 30-60 parts of polypropylene resin, 6-20 parts of talcum powder, and 5-15 parts of coated gel microspheres, wherein the coated gel microspheres comprise agarose gel and a coating layer of urea-formaldehyde resin on the surface of the agarose gel. The polypropylene composite material has good mechanical properties, scratch resistance, thermal insulation, and sound insulation and noise reduction.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer material modification, and particularly relates to a polypropylene composite material and a preparation method thereof. Background Art

[0002] With the development of my country's economy, the automobile industry is developing at an unprecedented speed, and its important role in the development of the national economy is becoming more and more apparent. As cars become more and more popular, people have higher requirements for cars, such as comfort, energy saving, beauty, environmental protection, safety and reliability. Higher requirements have been put forward in terms of environmental protection, energy saving and comfort, especially driving comfort. Material manufacturers have devoted a lot of technical strength to this, aiming to improve the application field of materials.

[0003] In the process of automobile plasticization, modified polypropylene materials are commonly used for automobile interior and exterior parts, such as instrument panels, door panels, pillars, bumpers, etc. However, the functionality is relatively single. On the one hand, they are used as decorative parts such as pillars, and on the other hand, they have certain safety requirements such as door panels, instruments, bumpers, etc. How to improve the functionality of automobile interior plastic parts has become a hot topic in the materials industry.

[0004] Improve the comfort of the driving process, at the same time, achieve energy conservation and environmental protection, give automotive plastic parts insulation and noise reduction functions, and can also meet the needs of scratch and wear resistance. Chinese patent CN201910052845.8 uses modified polypropylene, fumed silica modified acrylate, silicone modified acrylate and modified porous silica gel to prepare thermal insulation polypropylene plastic. The thermal insulation polypropylene plastic prepared by this method has excellent thermal insulation performance; Chinese patent CN201910670953.1 discloses a thermal insulation polypropylene composite material that uses porous silica coating to treat large-particle titanium oxide to reflect most of the solar radiation energy, reducing the total energy passively absorbed by the composite material. At the same time, due to the use of porous silica coating In principle, the polymer chain of polypropylene resin can wet and penetrate into the pores to form an IPN interpenetrating network structure, thereby increasing the bonding strength between polypropylene resin and titanium oxide, thereby improving the mechanical properties of polypropylene composite materials; in addition, high-pressure hollow glass microspheres are filled, and because the thermal conductivity of the hollow structure is low, the thermal conductivity of the composite material as a whole can be reduced; and the addition of a superdispersant allows the high-pressure hollow glass microspheres to maintain a good dispersion effect in the twin-screw extruder, avoiding the hollow glass microspheres from breaking due to the high shearing effect of the screw due to agglomeration, and maintaining a hollow state to ensure a low thermal conductivity. Chinese patent CN201910803227.2 uses matrix resin as the main material, adds barium sulfate and glass fiber, and adds coupling agent, dispersant, light stabilizer and scratch resistant agent, and by adjusting the dosage ratio of each component, the obtained high-density noise reduction firewall thermoplastic material has high rigidity, high toughness and high density at the same time. The density of the firewall thermoplastic material is similar to that of magnesium-aluminum alloy, which can effectively prevent resonance and has a good noise reduction effect. However, current materials cannot achieve good thermal insulation, noise reduction and scratch resistance at the same time. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a polypropylene composite material and a preparation method thereof, so as to overcome the defect that the polypropylene material in the prior art cannot have good heat insulation, noise reduction and scratch resistance.

[0006] The present invention provides a polypropylene composite material, wherein the polypropylene composite material components include, by weight:

[0007] 30-60 parts of polypropylene resin;

[0008] 6-20 parts of talcum powder;

[0009] 5-15 parts of coated gel microspheres;

[0010] The coated gel microspheres include agarose gel and a coating layer of urea-formaldehyde resin on the surface of the agarose gel.

[0011] Preferably, the polypropylene composite material components include, by weight:

[0012] 35-55 parts of polypropylene resin;

[0013] 8-15 parts of talcum powder;

[0014] 6-12 portions of coated gel microspheres.

[0015] Preferably, the melt flow rate of the polypropylene resin at 230° C. and 2.16 kg is 25-35 g / 10 min. The test standard for the melt flow rate is ISO 1133-1-2011.

[0016] Preferably, the polypropylene resin has a density of 0.89-0.90 g / cm 3 The density is tested according to ISO 1183-1-2019.

[0017] Preferably, the weight fraction of the talc powder in the polypropylene composite material is 10-20%.

[0018] Preferably, the weight fraction of silicon dioxide in the talc is 50-80%, more preferably 55-75%, and more preferably 60-70%. The test standard for this weight fraction is GB / T 15342-2012. When the weight fraction of silicon dioxide is too low, the curing rate of the urea-formaldehyde resin cured layer is low, and the scratch resistance effect deteriorates. When the weight fraction of silicon dioxide is too high, the scratch resistance effect deteriorates due to too much silicon dioxide. The reason for this deterioration is that too much silicon dioxide is exposed after scratching, resulting in poor scratch resistance.

[0019] Preferably, the weight fraction of agarose gel in the coated gel microspheres is 8-35%, more preferably 10-30%, and more preferably 15-25%. When the weight fraction of agarose gel is too low, the heat insulation and noise reduction effect is poor, and when the weight fraction of agarose gel is too high, the volume of the coated gel expands after decomposition, which may cause the wall material to rupture.

[0020] Preferably, the preparation method of the coated gel microspheres comprises: mixing urea and formaldehyde in a ratio of 1-2g:2.5-3.5mL, stirring to obtain urea-formaldehyde resin monomer, mixing agarose gel, water, and emulsifier in a ratio of 1-5g:8-12mL:1.8-2.2g (preferably 1.5-3g:8-12mL:1.8-2.2g), emulsifying, adding the above urea-formaldehyde resin monomer, adding a catalyst to react, washing, and drying to obtain, wherein the weight ratio of urea to catalyst is 1 to 2:1. The amount of agarose gel added divided by (amount of agarose gel added + weight of urea-formaldehyde resin) × 100% is the weight fraction of agarose gel in the coated gel microspheres.

[0021] Preferably, the stirring comprises: adjusting the pH value to 9-10, stirring at 20-40°C to dissolve the raw materials, and then heating to 60-80°C and maintaining for 1-3 hours.

[0022] Preferably, the emulsifier is Tween 80.

[0023] Preferably, the emulsification temperature is 55-65°C, and the emulsification time is 1-2h.

[0024] Preferably, the pH value is adjusted to 1-3 after emulsification.

[0025] Preferably, the urea-formaldehyde resin monomer is added at 70-80°C.

[0026] Preferably, the pH value is adjusted to 1-3 after adding the urea-formaldehyde resin monomer.

[0027] Preferably, the catalyst is aluminum oxide.

[0028] Preferably, the reaction temperature is 70-80°C and the reaction time is 2-4h.

[0029] Preferably, the polypropylene composite material further comprises 5-15 parts of a toughening agent, and more preferably, the toughening agent comprises 6-12 parts by weight.

[0030] Preferably, the toughening agent includes ethylene-octene copolymer POE and / or styrene-ethylene-butylene-styrene block copolymer SEBS.

[0031] Preferably, the polypropylene composite material further comprises 0-1.2 parts of a processing aid.

[0032] More preferably, the weight portion of the processing aid is 0.5-1 part.

[0033] Preferably, the processing aid includes one or more of an antioxidant, a weathering agent, and a lubricant.

[0034] Preferably, the antioxidant includes one or more of hindered phenol antioxidants, phosphite antioxidants, and thioester antioxidants.

[0035] Preferably, the weathering agent includes one or more of a hindered amine weathering agent, a hindered phenol weathering agent, and an ultraviolet absorber.

[0036] Preferably, the lubricant includes one or more of silicones, esters, amides, polyethylenes, stearic acids, and fatty acids.

[0037] The present invention also provides a method for preparing the above-mentioned polypropylene composite material, comprising:

[0038] The components except the coated gel microspheres are mixed to obtain a mixture, the mixture and the coated gel microspheres are added to a twin-screw extruder, and the mixture is extruded and granulated after mixing, melting and homogenizing to obtain a polypropylene composite material.

[0039] Preferably, the extrusion temperature of the twin-screw extruder is: 80-120°C in zone 1, 180-200°C in zones 2 to 5, and 200-230°C in zones 6 to 12; the aspect ratio of the extruder screw is 36-48:1.

[0040] Preferably, the mixed material is fed into the extruder from a main feed port, and the coated gel microspheres are fed into the extruder from a side feed port.

[0041] The present invention also provides an application of the polypropylene composite material in automobiles, such as door panels, pillars, etc.

[0042] The present invention adopts coated gel microspheres and talcum powder. The free silicon dioxide and urea-formaldehyde resin in the talcum powder are processed at a temperature of 160 to 230° C. The silicon dioxide accelerates the solidification of the urea-formaldehyde resin, so that the coating layer of the gel becomes insoluble and infusible solidified particles. On the one hand, the solidified particles in the blending system improve the mechanical properties and scratch resistance of the polypropylene composite material. On the other hand, after the coating layer is solidified, the internal gel will not overflow into the polypropylene composite system, and will not cause performance degradation and gel precipitation. The coated gel will melt after the processing temperature exceeds 90° C. When the temperature is reduced to below 40° C., the gel will become a semi-solid gel. On the one hand, the semi-solid gel has the effect of heat preservation and heat insulation, and plays the role of heat preservation and heat insulation. On the other hand, the gel processed at high temperature presents the characteristics of semi-solidity under normal use, which can reduce the propagation of vibration. At the same time, when the sound wave propagates in the semi-solid material, the energy is weakened, which plays the effect of sound insulation and noise reduction.

[0043] Beneficial Effects

[0044] The present invention adopts the compounding of coated gel microspheres and talcum powder, which can significantly improve the mechanical properties, scratch resistance, thermal insulation and sound insulation of polypropylene materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 This is a SEM image of the coated gel microspheres of the present invention. DETAILED DESCRIPTION

[0046] 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.

[0047] Source of reagents:

[0048] Polypropylene resin 1: PP EP548R, melt flow rate at 230°C, 2.16 kg is 28 g / 10 min, density is 0.89 g / cm 3 , Manufacturer: CNOOC Shell;

[0049] Polypropylene resin 2: PP K7227H, melt flow rate at 230°C, 2.16 kg is 30 g / 10 min, density is 0.89 g / cm 3 , Manufacturer: Wuhan Petrochemical;

[0050] Talc 1: 60% by weight of silicon dioxide, TYT-777A, manufacturer: Haicheng Tianyuan;

[0051] Talc 2: 68% by weight of silicon dioxide, AH-3000N8, manufacturer: Liaoning Aihai;

[0052] Talc 3: 58% by weight of silicon dioxide, TY90-7-C, Dongguan Sanzhi New Materials;

[0053] Talc 4: 71% by weight of silicon dioxide, TY90-8-A, Dongguan Sanzhi New Materials;

[0054] Coated gel microspheres 1: The weight fraction of agarose gel is 15%. The preparation method is as follows: add 1.5 g urea and 3 mL formaldehyde to a three-necked flask with a stirrer and a reflux condenser, adjust the pH value to 9-10 with triethanolamine, place in a constant temperature water bath at 30°C, stir, and after the raw materials are fully dissolved, heat to 70°C and maintain for 1 hour to obtain urea-formaldehyde resin monomer for use, add 0.53 g agarose gel (type C agarose, manufacturer: Aladdin reagent) to a 100 mL beaker Add 10mL of distilled water and 2.0g of Tween 80, emulsify in a 60℃ water bath with a shearing emulsifier for 1.5h, pour into a three-necked flask with a stirrer and a reflux condenser, adjust the pH value to about 2 with citric acid, heat the water bath to 70℃, slowly drop urea-formaldehyde resin monomer, adjust the pH value to about 2 with citric acid, add 1g of aluminum oxide solid, and then react in a 70℃ constant temperature water bath for 3h, wash twice with distilled water and anhydrous ethanol, and dry to obtain;

[0055] Coated gel microsphere 2: The weight fraction of agarose gel is 25%. The preparation method is the same as that of coated gel microsphere 1, except that 0.53 g of agarose gel is changed to 1 g of agarose gel, and the rest is the same;

[0056] Coated gel microsphere 3: The weight fraction of agarose gel is 12%. The preparation method is the same as that of coated gel microsphere 1, except that 0.53 g of agarose gel is changed to 0.41 g of agarose gel, and the rest is the same;

[0057] Coated gel microsphere 4: The weight fraction of agarose gel is 27%. The preparation method is the same as that of coated gel microsphere 1, except that 0.53 g of agarose gel is changed to 1.11 g of agarose gel, and the rest is the same;

[0058] Agarose gel: C-type agarose, manufacturer: Aladdin reagent;

[0059] Urea-formaldehyde resin: Manufacturer: Shanghai McLean Biochemical Technology Co., Ltd.;

[0060] Silicone scratch agent: BZPP301, manufacturer: Chongqing Baozhuan New Material Technology Co., Ltd.;

[0061] Toughener 1: ethylene-octene copolymer POE, POE 7447, manufacturer: Dow;

[0062] Toughener 2: styrene-ethylene-butylene-styrene block copolymer SEBS, SEBS 6151, manufacturer: Taiwan Rubber Corporation;

[0063] Processing aids:

[0064] Antioxidant: pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] and tris(2,4-di-tert-butylphenyl) phosphite are compounded in a weight ratio of 1:1 and are commercially available;

[0065] Lubricant: erucamide, commercially available;

[0066] If not specifically stated, certain components (such as antioxidants, lubricants) in the parallel embodiments and comparative examples of the present invention are the same commercially available products.

[0067] The preparation method of the polypropylene composite material comprises: mixing the components except the coated gel microspheres according to the proportions in Table 1 and Table 2 to obtain a mixture, adding the mixture into a twin-screw extruder from a main feed port, adding the coated gel microspheres into the extruder from a side feed port, and extruding and granulating after mixing, melting and homogenizing to obtain a polypropylene composite material, wherein the extrusion temperature of the extruder is: 80-120° C. in zone 1, 180-200° C. in zones 2 to 5, and 200-230° C. in zones 6 to 12; and the length-to-diameter ratio of the screw of the twin-screw extruder is 36-48:1.

[0068] Performance Test:

[0069] (1) Mechanical properties: Tensile strength is in accordance with the test standard ISO 527-1:2012, specimen size: 115*10*4mm, tensile rate 50mm / min;

[0070] Bending strength is in accordance with the test standard ISO 178-2019, specimen size: 80*10*4mm, bending rate 2mm / min;

[0071] The bending modulus is in accordance with the test standard ISO 178-2019, the specimen size is 80*10*4mm, and the bending rate is 2mm / min;

[0072] The notched cantilever beam impact strength is in accordance with the test standard ISO 180-2019, the specimen size is 80*10*4mm, the notch is type 1A notch, and the pendulum energy is 2.75J;

[0073] (2) Scratch resistance (ΔL) test: Executed according to Volkswagen PV3952 standard, load 10N. Generally, OEMs require ΔL≤2. The larger the value, the worse the scratch resistance.

[0074] (3) Thermal insulation test: The polypropylene composite material was injection molded into a 100*100*100 mm square box with a wall thickness of 3 mm and a built-in temperature sensor. The box was placed in a 60°C constant temperature box to detect the temperature changes inside the box and record the temperature data. The higher the temperature, the worse the thermal insulation effect.

[0075] (4) Noise test: Conducted in accordance with GB / T18696.2-2002 standard, with a sample thickness of 3 mm, a sound source frequency of 400 Hz, and a sound source noise of 90 dB. The amount of noise received is detected. The greater the amount of noise, the worse the noise reduction effect. At the same time, the test environment is in a temperature change process of 30 to 60°C, simulating the ambient temperature change process of daily driving.

[0076] Table 1 Example ratio (parts by weight)

[0077]

[0078]

[0079] Table 2 Comparative Example Proportions (parts by weight)

[0080]

[0081] As shown in Table 1-2, the tensile strength of polypropylene composite materials is 15-23MPa, the flexural strength is 19-42MPa, the flexural modulus is 1550-2700MPa, and the cantilever beam notched impact strength is 17-35KJ / m 2, scratch resistance is 0.3-1.9, thermal insulation test temperature is 30-52℃, and noise level is 30-61dB. Within the range of silica content specified in the present invention, the change in silica content has little effect on the tensile strength, impact strength and other properties of the polypropylene composite material, and fluctuates within a small range. Comparative Example 1 does not add talcum powder, Comparative Example 2 does not add coated gel microspheres, and Comparative Example 3 uses agarose gel and urea-formaldehyde resin. The mechanical properties, scratch resistance, thermal insulation test temperature and noise level of the polypropylene composite materials in Comparative Examples 1-3 are not as good as those in Example 1. Comparative Example 4 uses a silicone scratch agent, and the mechanical properties, thermal insulation test temperature and noise level of the polypropylene composite material in Comparative Example 4 are not as good as those in Example 1. It can be seen that the present invention uses coated gel microspheres and talcum powder to compound, which can significantly improve the mechanical properties, scratch resistance, thermal insulation and sound insulation and noise reduction of polypropylene materials.

Claims

1. A polypropylene composite material, characterized in that: The polypropylene composite material components include, by weight: 30-60 parts of polypropylene resin; 6-20 parts of talcum powder; 5-15 parts of coated gel microspheres; The coated gel microspheres include agarose gel and a coating layer of urea-formaldehyde resin on the surface of the agarose gel; the preparation method of the coated gel microspheres includes: reacting urea and formaldehyde to obtain urea-formaldehyde resin monomer, emulsifying after mixing agarose gel, water and an emulsifier, adding the urea-formaldehyde resin monomer, and adding a catalyst for reaction to obtain the coated gel microspheres; the weight fraction of agarose gel in the coated gel microspheres is 8-35%; the weight fraction of silicon dioxide in the talc is 50-80%.

2. The polypropylene composite material according to claim 1, characterized in that: The polypropylene composite material components include, by weight: 35-55 parts of polypropylene resin; 8-15 parts of talcum powder; 6-12 portions of coated gel microspheres.

3. The polypropylene composite material according to claim 1, characterized in that: The polypropylene composite material further comprises 5-15 parts of a toughening agent; the toughening agent comprises ethylene-octene copolymer POE and / or styrene-ethylene-butylene-styrene block copolymer SEBS.

4. The polypropylene composite material according to claim 1, characterized in that: The polypropylene composite material also includes 0-1.2 parts of processing aids; the processing aids include one or more of antioxidants, weathering agents, and lubricants.

5. A method for preparing the polypropylene composite material according to any one of claims 1 to 4, comprising: The components except the coated gel microspheres are mixed to obtain a mixture, and the mixture and the coated gel microspheres are extruded and granulated to obtain a polypropylene composite material.

6. The preparation method according to claim 5, characterized in that: The extrusion temperature is: 80-120°C in zone 1, 180-200°C in zones 2 to 5, and 200-230°C in zones 6 to 12; the screw length-to-diameter ratio used in extrusion granulation is 36-48:

1.

7. Use of the polypropylene composite material according to any one of claims 1 to 4 or the polypropylene composite material prepared by the method according to any one of claims 5 to 6 in automobiles.

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