Regenerated polypropylene composite material as well as preparation method and application thereof

Abstract

The invention discloses a regenerated polypropylene composite material as well as a preparation method and application thereof. The composite material comprises the following raw materials in parts by mass: 35-90 parts of a regenerated polypropylene material, 5-30 parts of polypropylene resin, 10-50 parts of glass fibers, 1-10 parts of a compatilizer, 0.1-5 parts of a deodorant and 0.1-5 parts of a functional aid. The compatilizer is prepared from a polypropylene-maleic anhydride graft, and the maleic anhydride grafting rate of the polypropylene-maleic anhydride graft is 0.8 to 1.5 weight percent; the deodorant comprises an inorganic adsorption type deodorant. According to the invention, the regenerated polypropylene material is used as a base material, and by adding a small amount of polypropylene resin and combining the glass fiber, the polypropylene-maleic anhydride graft with a high maleic anhydride grafting rate and the inorganic adsorption type deodorant, good compatibility among the raw materials can be ensured, and the mechanical properties of the material are effectively improved; and odor molecules are better devolatilized in the processing process, so that the odor requirement is met.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer materials, and in particular relates to a recycled polypropylene composite material and a preparation method and application thereof. Background Art

[0002] Polypropylene (PP) materials are widely used in the automotive field due to their low specific gravity, excellent mechanical properties, low cost, easy processing, chemical resistance and other characteristics. Taking automotive polypropylene reinforced materials as an example, the polypropylene material modified by glass fiber reinforcement has light weight, high strength, good impact resistance, corrosion resistance, easy processing and molding, and low cost. It is a cost-effective solution among many solutions for lightweight automotive applications.

[0003] With the vigorous development of new energy vehicles, the use of polypropylene glass fiber reinforced materials in automotive interior and exterior decoration has gradually increased, and its odor and VOC have also attracted more and more attention. Glass fiber reinforced polypropylene materials are usually difficult to recycle and do not meet the national low-carbon living requirements of energy conservation and emission reduction; the mechanical properties are greatly reduced after secondary processing, and it is difficult to meet the standards for the use of automotive materials. Using recycled polypropylene as a reinforced composite material substrate is a low-carbon and green solution. However, recycled polypropylene is usually accompanied by reduced performance, odor, and excessive VOC problems, and it cannot be widely promoted and used at present. Therefore, the development of a low-odor recycled polypropylene glass fiber reinforced composite material is of great significance to meet the lightweight requirements of automobiles and achieve energy conservation and emission reduction goals. Summary of the invention

[0004] In order to overcome at least one of the problems existing in the above-mentioned prior art, one of the objectives of the present invention is to provide a recycled polypropylene composite material.

[0005] A second object of the present invention is to provide a method for preparing the above-mentioned recycled polypropylene composite material.

[0006] The third object of the present invention is to provide an application of the above-mentioned recycled polypropylene composite material.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is:

[0008] The first aspect of the present invention provides a recycled polypropylene composite material, comprising the following raw materials in parts by weight: 35 to 90 parts of recycled polypropylene material, 5 to 30 parts of polypropylene resin, 10 to 50 parts of glass fiber, 1 to 10 parts of a compatibilizer, 0.1 to 5 parts of a deodorant, and 0.1 to 5 parts of a functional additive; the compatibilizer comprises a polypropylene-maleic anhydride graft, and the maleic anhydride graft rate of the polypropylene-maleic anhydride graft is 0.8 to 1.5wt%; the deodorant comprises an inorganic adsorption-type deodorant.

[0009] In some specific embodiments of the present invention, the ash content of the recycled polypropylene material is ≤3 wt%.

[0010] In some specific embodiments of the present invention, the melt index of the recycled polypropylene material at 230° C. and 2.16 kg is 1 to 80 g / 10 min.

[0011] In some specific embodiments of the present invention, the recycled polypropylene material is selected from homopolypropylene.

[0012] In some specific embodiments of the present invention, the melt index of the polypropylene resin at 230° C. and 2.16 kg is 1 to 30 g / 10 min.

[0013] In some specific embodiments of the present invention, the polypropylene resin is selected from copolymerized polypropylene.

[0014] In some specific embodiments of the present invention, the compatibilizer is selected from polypropylene-maleic anhydride grafts.

[0015] In some specific embodiments of the present invention, the residual maleic anhydride content of the polypropylene-maleic anhydride graft product is 5 to 12 wt %.

[0016] In some specific embodiments of the present invention, the deodorant is selected from inorganic adsorption deodorants.

[0017] In some specific embodiments of the present invention, the active ingredient of the inorganic adsorption deodorant includes silicon-based inorganic minerals.

[0018] In some specific embodiments of the present invention, the particle size of the inorganic adsorption deodorant is 100 to 1000 nm.

[0019] In some specific embodiments of the present invention, the glass fiber is selected from sizing-modified glass fibers.

[0020] In some specific embodiments of the present invention, the monofilament diameter of the glass fiber is 10-25 μm.

[0021] In some specific embodiments of the present invention, the linear density of the glass fiber is 2200-2600 g / km.

[0022] In some specific embodiments of the present invention, the glass fiber is selected from EDR768P-2400.

[0023] In some specific embodiments of the present invention, the functional auxiliary agent includes an antioxidant, a lubricant or a combination thereof.

[0024] The second aspect of the present invention provides a method for preparing the recycled polypropylene composite material described in the first aspect of the present invention, comprising the following steps: mixing the raw materials, performing extrusion molding, and obtaining the recycled polypropylene composite material.

[0025] In some specific embodiments of the present invention, the processing temperature of the extrusion molding is 50-250°C.

[0026] In some specific embodiments of the present invention, the extrusion molding is performed by screw extrusion, and the screw speed is 250-500r / min.

[0027] The third aspect of the present invention provides a use of the recycled polypropylene composite material described in the first aspect of the present invention in the preparation of automobile parts.

[0028] The beneficial effects of the present invention are as follows: the present invention uses recycled polypropylene material as a base material, and by adding less polypropylene resin and combining with glass fiber, the mechanical properties of the material can be effectively improved; and the use of polypropylene-maleic anhydride grafted material with a high maleic anhydride grafting rate can ensure good compatibility between the glass fiber and the polypropylene base material; and the use of an inorganic adsorption deodorant helps to better de-volatilize small odor molecules during the processing process, thereby ensuring that the obtained recycled polypropylene composite material can meet the odor requirements.

[0029] Specifically, compared with the prior art, the present invention has the following advantages:

[0030] 1. The present invention introduces glass fibers with a relatively suitable monofilament diameter, which is helpful for good dispersion of the glass fibers in the polypropylene resin matrix, thereby obtaining a longer retention length; the glass fibers specifically used in the present invention are a thermoplastic direct yarn, which is treated with a specific impregnating agent and has good compatibility with the polypropylene matrix, and can further improve the mechanical strength of the obtained recycled polypropylene composite material.

[0031] 2. Adding polypropylene-maleic anhydride grafted material with a high maleic anhydride grafting rate can ensure good compatibility between glass fiber and polypropylene resin. At the same time, it has a low maleic anhydride residual content, which can reduce the impact of the introduction of polypropylene-maleic anhydride grafted material as a compatibilizer on the odor and VOC of the composite material from the source.

[0032] 3. Adding inorganic adsorption deodorizer can help to better de-volatilize odor molecules during the processing process, ensuring that the obtained recycled polypropylene composite material can meet the odor requirements.

[0033] 4. The preparation method of the present invention is simple, the process operation is easy to implement, and the obtained recycled polypropylene composite material can meet the requirements of materials such as automobile brackets and air filters, and has good application prospects in the preparation of automobile parts. DETAILED DESCRIPTION

[0034] The content of the present invention is further described in detail below through specific examples. It should also be understood that the following examples are only used to further illustrate the present invention and cannot be construed as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the principles set forth in the present invention all belong to the scope of protection of the present invention. The specific process parameters and the like in the following examples are also only examples within a suitable range, that is, those skilled in the art can make a selection within a suitable range through the description herein, and are not limited to the specific data exemplified below. The raw materials, reagents or devices used in the following examples and comparative examples, unless otherwise specified, can all be obtained from conventional commercial sources, or can be obtained by existing known methods.

[0035] A first aspect of an embodiment of the present invention provides a recycled polypropylene composite material, comprising the following raw materials in parts by weight: 35 to 90 parts of recycled polypropylene material, 5 to 30 parts of polypropylene resin, 10 to 50 parts of glass fiber, 1 to 10 parts of a compatibilizer, 0.1 to 5 parts of a deodorant, and 0.1 to 5 parts of a functional additive; the compatibilizer comprises a polypropylene-maleic anhydride graft, and the maleic anhydride graft rate of the polypropylene-maleic anhydride graft is 0.8 to 1.5 wt%; the deodorant comprises an inorganic adsorption-type deodorant.

[0036] The embodiment of the present invention uses recycled polypropylene material as the base material, and can effectively improve the mechanical properties of the material by adding less polypropylene resin and combining it with glass fiber; and the use of polypropylene-maleic anhydride grafted material with a higher maleic anhydride grafting rate can ensure good compatibility between glass fiber and polypropylene resin and recycled polypropylene material; and the use of inorganic adsorption deodorant helps to better de-volatilize small odor molecules during the processing process, ensuring that the obtained recycled polypropylene composite material can meet the odor requirements.

[0037] It should be noted that the polypropylene resin of the present invention refers to new polypropylene resin.

[0038] In some embodiments of the present invention, the ash content of the recycled polypropylene material is ≤3wt%; in some specific embodiments of the present invention, the ash content of the recycled polypropylene material is ≤2.5wt%; in some examples of the present invention, the ash content of the recycled polypropylene material is ≤2wt%. Non-limiting specific examples include 1.8wt%, 1.5wt%, 1.2wt%, 1wt% or 0.5wt%.

[0039] The use of recycled polypropylene materials with lower ash content has better processing performance and is conducive to better compounding with other raw materials to form composite materials with higher strength and lower odor.

[0040] In some embodiments of the present invention, the melt index of the recycled polypropylene material at 230°C and 2.16 kg is 1 to 80 g / 10 min; in some specific embodiments of the present invention, the melt index of the recycled polypropylene material at 230°C and 2.16 kg is 2 to 70 g / 10 min. Non-limiting specific examples include 3 g / 10 min, 5 g / 10 min, 10 g / 10 min, 20 g / 10 min, 30 g / 10 min, 40 g / 10 min, 50 g / 10 min or 60 g / 10 min.

[0041] The recycled polypropylene material that can be used in the present invention has a wide range of melt indexes. Modification treatment is performed on recycled polypropylene materials with different melt indexes to obtain a recycled polypropylene composite material with excellent performance, thereby realizing the recycling of more recycled materials.

[0042] In some embodiments of the present invention, the recycled polypropylene material is selected from homopolypropylene.

[0043] In some embodiments of the present invention, the tensile strength of the recycled polypropylene material is ≥28 MPa; non-limiting specific examples are 30 MPa, 50 MPa, 70 MPa or 100 MPa.

[0044] In some embodiments of the present invention, the flexural modulus of the recycled polypropylene material is ≥1100 MPa; non-limiting specific examples are 1150 MPa, 1200 MPa, 1500 MPa or 2000 MPa.

[0045] In some embodiments of the present invention, the Izod notched impact strength of the recycled polypropylene material is ≥ 2 kJ / m 2 ; Non-limiting specific examples such as 3kJ / m 2 , 5kJ / m 2 , 7kJ / m 2 or 10 kJ / m 2 .

[0046] In some embodiments of the present invention, the recycled polypropylene material comes from a woven bag, the ash content is ≤2wt%, the tensile strength is ≥28MPa, the flexural modulus is ≥1100MPa, and the Izod notched impact strength is ≥2kJ / m 2 .

[0047] In other embodiments of the present invention, the recycled polypropylene material comes from a lunch box, the ash content is ≤2wt%, the tensile strength is ≥28MPa, the flexural modulus is ≥1100MPa, and the Izod notched impact strength is ≥2kJ / m 2 .

[0048] In some embodiments of the present invention, the melt index of the polypropylene resin at 230°C and 2.16 kg is 1 to 30 g / 10 min; in some specific embodiments of the present invention, the melt index of the polypropylene resin at 230°C and 2.16 kg is 5 to 25 g / 10 min; in some specific embodiments of the present invention, the melt index of the polypropylene resin at 230°C and 2.16 kg is 8 to 20 g / 10 min. Non-limiting specific examples include 10 g / 10 min, 12 g / 10 min, 15 g / 10 min, or 18 g / 10 min.

[0049] The polypropylene resin of the present invention can have a wide range of melt indexes. Composite materials with different melt indexes can be obtained by combining recycled polypropylene materials with polypropylene resins to meet the melt index requirements of different injection molding product structures and realize customized application of materials.

[0050] In some embodiments of the present invention, the polypropylene resin is selected from copolymer polypropylene; in some specific embodiments of the present invention, the polypropylene resin is selected from block copolymer polypropylene.

[0051] In some embodiments of the present invention, the compatibilizer is selected from polypropylene-maleic anhydride grafts.

[0052] In some embodiments of the present invention, the maleic anhydride grafting rate of the polypropylene-maleic anhydride graft is 0.8-1.5wt%; in some specific embodiments of the present invention, the maleic anhydride grafting rate of the polypropylene-maleic anhydride graft is 0.9-1.3wt%; in some examples of the present invention, the maleic anhydride grafting rate of the polypropylene-maleic anhydride graft is 1-1.2wt%. Non-limiting specific examples include 1.02wt%, 1.05wt%, 1.08wt%, 1.1wt%, 1.15wt% or 1.08wt%.

[0053] In some embodiments of the present invention, the maleic anhydride grafting rate of the polypropylene-maleic anhydride graft is measured by acid-base titration method.

[0054] In some embodiments of the present invention, the maleic anhydride residual rate of the polypropylene-maleic anhydride graft is 5-12wt%; in some specific embodiments of the present invention, the maleic anhydride residual rate of the polypropylene-maleic anhydride graft is 6-11wt%; in some examples of the present invention, the maleic anhydride residual rate of the polypropylene-maleic anhydride graft is 8-10wt%. Non-limiting specific examples include 8.5wt%, 9wt% or 9.5wt%.

[0055] In some embodiments of the present invention, the residual maleic anhydride rate of the polypropylene-maleic anhydride grafted product = (maleic anhydride added - maleic anhydride grafted amount) / total amount of maleic anhydride added.

[0056] The polypropylene-maleic anhydride grafted product used in the present invention has a high maleic anhydride grafting rate, thereby ensuring good compatibility between glass fiber and raw materials such as polypropylene resin, and also has a low maleic anhydride residue, thereby reducing the influence of the introduction of the compatibilizer on the odor and VOC of the composite material from the source.

[0057] In some embodiments of the present invention, the compatibilizer is selected from CMG5701.

[0058] The compatibilizer CMG5701 used in the embodiment of the present invention is produced by Jiayirong Polymer Co., Ltd. and is a low-odor, low-VOC polypropylene-maleic anhydride graft. The maleic anhydride graft rate is 0.8-1.2wt%, more specifically 1.03wt%; the maleic anhydride residual rate is 8-10wt%, more specifically 9.6wt%.

[0059] In some embodiments of the present invention, the deodorant is selected from inorganic adsorption deodorants.

[0060] In some embodiments of the present invention, the active ingredient of the inorganic adsorption deodorant includes silicon-based inorganic minerals; in some specific embodiments of the present invention, the silicon-based inorganic minerals include at least one of quartz, feldspar, mica, clay, talc or diatomaceous earth.

[0061] In some embodiments of the present invention, the particle size of the inorganic adsorption deodorant is 100-1000 nm; non-limiting specific examples are 200 nm, 400 nm, 500 nm, 700 nm or 900 nm.

[0062] In some embodiments of the present invention, the inorganic adsorption-type deodorant has an active adsorption group.

[0063] In some embodiments of the present invention, the deodorant is selected from XW-1200.

[0064] The deodorant XW-1200 used in the embodiment of the present invention is produced by Qingdao Zhuoxin Technology Co., Ltd. It is mainly a submicron powder prepared by fine processing and modification of natural mineral silicon-based inorganic substances. The product has a submicron particle size distribution, a large specific surface area, and contains active groups, has strong physical adsorption and chemical chelation, and has no secondary volatilization during molding and processing. The deodorant XW-1200 can effectively adsorb the odor small molecules generated during the processing in the polypropylene resin system of the present invention, effectively reduce the odor intensity of the composite material, and has good compatibility with the system of the present invention, low usage, and will not affect the mechanical properties of the composite material, etc., and can produce a composite material with both good mechanical properties and low odor.

[0065] In some embodiments of the present invention, the glass fibers are selected from sizing-modified glass fibers.

[0066] In some embodiments of the present invention, the diameter of the glass fiber monofilament is 10-25 μm; in some embodiments of the present invention, the diameter of the glass fiber monofilament is 12-22 μm; in some embodiments of the present invention, the diameter of the glass fiber monofilament is 15-20 μm. Non-limiting specific examples are 16 μm, 17 μm, 18 μm or 19 μm.

[0067] The introduction of glass fibers with a monofilament diameter within a specific range is beneficial to the good dispersion of the glass fibers in the polypropylene resin matrix, thereby obtaining a longer retention length to effectively improve the mechanical strength of the composite material.

[0068] In some embodiments of the present invention, the linear density of the glass fiber is 2200-2600 g / km; in some embodiments of the present invention, the linear density of the glass fiber is 2250-2550 g / km; in some embodiments of the present invention, the linear density of the glass fiber is 2300-2500 g / km. Non-limiting specific examples include 2350 g / km, 2380 g / km, 2400 g / km, 2420 g / km or 2450 g / km.

[0069] In some embodiments of the present invention, the glass fiber is selected from EDR768P-2400.

[0070] The glass fiber EDR768P-2400 used in the embodiment of the present invention is produced by Chongqing International Composite Materials Co., Ltd., has a linear density of 2400g / km, a monofilament diameter of 17μm, and is a thermoplastic direct yarn. The glass fiber EDR768P-2400 is treated with a specific sizing agent and has good compatibility with the polypropylene resin substrate of the present invention, so it can effectively improve the mechanical strength of the obtained recycled polypropylene composite material.

[0071] In some embodiments of the present invention, the recycled polypropylene composite material includes the following raw materials in parts by weight: 38 to 85 parts of recycled polypropylene material, 8 to 28 parts of polypropylene resin, 15 to 45 parts of glass fiber, 2 to 9 parts of compatibilizer, 0.3 to 3 parts of deodorant, and 0.3 to 3 parts of functional additive.

[0072] In some specific embodiments of the present invention, the recycled polypropylene composite material includes the following raw materials in parts by weight: 40 to 80 parts of recycled polypropylene material, 10 to 25 parts of polypropylene resin, 20 to 40 parts of glass fiber, 3 to 8 parts of compatibilizer, 0.5 to 2 parts of deodorizer, and 0.5 to 1 part of functional additive.

[0073] In some embodiments of the present invention, the functional aid includes an antioxidant, a lubricant, or a combination thereof; in some embodiments of the present invention, the functional aid includes an antioxidant and a lubricant.

[0074] In some embodiments of the present invention, the antioxidant includes a hindered phenol antioxidant, a phosphite antioxidant or a combination thereof; in some specific embodiments of the present invention, the antioxidant includes a hindered phenol antioxidant and a phosphite antioxidant.

[0075] In some embodiments of the present invention, the hindered phenol antioxidant includes at least one of antioxidant 1010 , antioxidant 1076 , or antioxidant 1330 .

[0076] In some embodiments of the present invention, the phosphite antioxidant includes at least one of antioxidant 168 , antioxidant 626 , or antioxidant 618 .

[0077] In some embodiments of the present invention, the antioxidant includes at least one of antioxidant 1010, antioxidant 1076, antioxidant 1330, antioxidant 168, antioxidant 626 or antioxidant 618; in some specific embodiments of the present invention, the antioxidant includes antioxidant 1010, antioxidant 168 or a combination thereof; in some examples of the present invention, the antioxidant includes antioxidant 1010 and antioxidant 168.

[0078] In some embodiments of the present invention, the antioxidant includes antioxidant 1010 and antioxidant 168, and the mass ratio of antioxidant 1010 to antioxidant 168 is 1:(1-5); in some specific embodiments of the present invention, the mass ratio of antioxidant 1010 to antioxidant 168 is 1:(1.5-3); non-limiting specific examples are 1:1.8, 1:2 or 1:2.5.

[0079] In some embodiments of the present invention, the lubricant includes at least one of a fatty acid amide lubricant, a hydrocarbon lubricant or an ester lubricant; in some specific embodiments of the present invention, the lubricant is selected from a fatty acid amide lubricant.

[0080] In some embodiments of the present invention, the fatty acid amide lubricant includes at least one of oleamide (E wax), ethylene bisstearamide (EBS), modified ethylene bisfatty acid amide (TAF), erucic acid amide or stearic acid amide; in some specific embodiments of the present invention, the fatty acid amide lubricant includes ethylene bisstearamide (EBS), modified ethylene bisfatty acid amide (TAF) or a combination thereof; in some examples of the present invention, the fatty acid amide lubricant includes ethylene bisstearamide (EBS) and modified ethylene bisfatty acid amide (TAF).

[0081] In some embodiments of the present invention, the fatty acid amide lubricant includes ethylene bisstearamide (EBS) and modified ethylene bisfatty acid amide (TAF), and the mass ratio of ethylene bisstearamide (EBS) and modified ethylene bisfatty acid amide (TAF) is 1: (0.5-2); in some specific embodiments of the present invention, the mass ratio of ethylene bisstearamide (EBS) and modified ethylene bisfatty acid amide (TAF) is 1: (0.8-1.5); non-limiting specific examples are 1:1, 1:1.1 or 1:1.3.

[0082] In the embodiment of the present invention, by adding specific amounts and specific types of antioxidants and lubricants, better processing performance can be achieved, and a recycled polypropylene composite material with better comprehensive performance can be obtained.

[0083] In some embodiments of the present invention, the recycled polypropylene composite material includes the following raw materials in parts by weight: 35 to 90 parts of recycled polypropylene material, 5 to 30 parts of polypropylene resin, 10 to 50 parts of glass fiber, 1 to 10 parts of compatibilizer, 0.1 to 5 parts of deodorant, 0.1 to 2 parts of antioxidant, and 0.1 to 3 parts of lubricant.

[0084] In some specific embodiments of the present invention, the recycled polypropylene composite material includes the following raw materials in parts by weight: 38 to 85 parts of recycled polypropylene material, 8 to 28 parts of polypropylene resin, 15 to 45 parts of glass fiber, 2 to 9 parts of compatibilizer, 0.3 to 3 parts of deodorant, 0.15 to 1 part of antioxidant, and 0.2 to 2 parts of lubricant.

[0085] In some examples of the present invention, the recycled polypropylene composite material includes the following raw materials in parts by weight: 40 to 80 parts of recycled polypropylene material, 10 to 25 parts of polypropylene resin, 20 to 40 parts of glass fiber, 3 to 8 parts of compatibilizer, 0.5 to 2 parts of deodorant, 0.2 to 0.4 parts of antioxidant, and 0.3 to 0.6 parts of lubricant.

[0086] The second aspect of the embodiment of the present invention provides a method for preparing the recycled polypropylene composite material of the first aspect of the embodiment of the present invention, comprising the following steps: mixing the raw materials, performing extrusion molding, and obtaining the recycled polypropylene composite material.

[0087] In some embodiments of the present invention, the processing temperature of extrusion molding is 50-250°C; in some specific embodiments of the present invention, the processing temperature of extrusion molding is 60-220°C; non-limiting specific examples are 80°C, 100°C, 120°C, 150°C, 180°C or 200°C.

[0088] The specific extrusion molding processing temperature can be selected according to the specific raw materials, actual processing conditions, performance requirements, etc.

[0089] In some embodiments of the present invention, extrusion molding is carried out by screw extrusion, and the screw speed is 250-500r / min; in some specific embodiments of the present invention, the screw speed is 300-450r / min; non-limiting specific examples are 320r / min, 350r / min, 380r / min, 400r / min or 420r / min.

[0090] In some embodiments of the present invention, injection molding is performed after extrusion molding.

[0091] In some embodiments of the present invention, the temperature of injection molding is 160-220°C; in some specific embodiments of the present invention, the temperature of injection molding is 180-200°C.

[0092] In some embodiments of the present invention, during injection molding, the temperatures of the zones from the feeding section to the nozzle end are 180-190° C., 180-190° C., and 185-200° C., respectively.

[0093] In some embodiments of the present invention, the holding time of injection molding is 1 to 10 seconds; in some embodiments of the present invention, the holding time of injection molding is 2 to 4 seconds.

[0094] In some embodiments of the present invention, the injection pressure of injection molding is 30-70 MPa; in some embodiments of the present invention, the injection pressure of injection molding is 40-60 MPa.

[0095] A third aspect of the embodiments of the present invention provides a use of the recycled polypropylene composite material according to the first aspect of the present invention in the preparation of automobile parts.

[0096] In some embodiments of the present invention, the automobile component includes at least one of an automobile interior component, an automobile exterior component or an automobile structural component; non-limiting specific examples include a steering wheel, an instrument panel, an automobile bracket, an air filter, a bumper, etc.

[0097] The present invention is further described below in conjunction with specific embodiments and comparative examples.

[0098] Examples 1 to 6 and Comparative Examples 1 to 10

[0099] Examples 1 to 6 and Comparative Examples 1 to 10 each provide a recycled polypropylene composite material, and specific preparation raw materials and amounts are shown in Table 1.

[0100] The recycled polypropylene composite materials of Examples 1 to 6 and Comparative Examples 1 to 10 are prepared by the following steps:

[0101] Add all raw materials into a high-speed mixer, adjust the mixer speed to 500r / min, stir for 5 minutes, and then transfer to a twin-screw extruder. Add the thermoplastic direct yarn from the glass fiber port of the extruder, extrude, cool, granulate, and dry to obtain a recycled polypropylene composite material, wherein the processing temperature of each zone of the twin-screw extruder is 60-220°C, and the screw speed is 300-450r / min.

[0102] Table 1 Raw materials and dosage of recycled polypropylene composite materials of Examples 1 to 6 and Comparative Examples 1 to 10

[0103]

[0104]

[0105] The specific information of each raw material in Table 1 is as follows:

[0106] PP resin 1: woven bag recycled material, melt index is 3g / 10min at 230℃ / 2.16kg;

[0107] PP resin 2: lunch box recycled material, melt index is 55g / 10min at 230℃ / 2.16kg;

[0108] PP resin 3: JM-350, Lotte Chemical, melt index 10g / 10min at 230℃ / 2.16kg;

[0109] PP resin 4: 2832E1, ExxonMobil, melt index 3 g / 10 min at 230°C / 2.16 kg;

[0110] PP resin 5: PPH-Y26, Zhenhai Refining and Chemical, melt index is 26g / 10min at 230℃ / 2.16kg;

[0111] Compatibilizer 1: Jiayirong polymer, CMG5701, maleic anhydride grafting rate is 0.8-1.2%;

[0112] Compatibilizer 2: Shenyang Ketong, KT-1, maleic anhydride grafting rate is 0.6-1%;

[0113] Glass fiber 1: Chongqing International Composite Materials Co., Ltd., EDR768P-2400;

[0114] Fiberglass 2: Jushi Group, EDR17-2400-988A;

[0115] Deodorant 1: Qingdao Zhuoxin Deodorant, XW-1200;

[0116] Deodorant 2: Guangzhou OSI, OS-206A;

[0117] Antioxidants: Irganox 1010 and Irganox 168, BASF, mass ratio 1:2;

[0118] Lubricant: EBS and TAF-A, mass ratio is 1:1.

[0119] Performance Testing

[0120] The recycled polypropylene composite materials prepared in Examples 1 to 6 and Comparative Examples 1 to 10 were injection molded (the process conditions of injection molding: the nozzle temperature was 190°C, the temperatures of the three sections from the feeding section to the nozzle were 185°C, 185°C, 190°C, the holding time was 2 to 4s, and the injection pressure was 40 to 60MPa) as standard test specimens for performance testing. Among them, tensile strength: tested in accordance with ISO 527:2012 standard; flexural strength: tested in accordance with ISO 178:2019 standard; flexural modulus: tested in accordance with ISO 178:2019 standard; cantilever beam notched impact strength: tested in accordance with ISO 180:2019 standard; odor: baked at 80°C for 2h, odor evaluation was performed at above 60°C, and the standard was ≤3.2 level.

[0121] The test results are shown in Table 2.

[0122] Table 2 Performance test results of recycled polypropylene composite materials of Examples 1 to 6 and Comparative Examples 1 to 10

[0123]

[0124] From the analysis of Table 2, we can see that:

[0125] It can be seen from Comparative Examples 1-2 and Examples 1-2 that when a low-odor compatibilizer is added but no deodorizer is added, the prepared recycled polypropylene composite material cannot meet the odor requirements of the main engine plant.

[0126] It can be seen from Comparative Examples 3 to 4 and Examples 1 to 2 that when a conventional compatibilizer is added without a deodorizer, the polypropylene resin virgin material with a low odor itself is modified, and the obtained polypropylene composite material cannot meet the odor requirements of the main engine factory; it can be seen from Comparative Examples 5 to 6 and Examples 1 to 2 that the recycled polypropylene composite material prepared by using a conventional compatibilizer in combination with the addition of a deodorizer also cannot meet the odor requirements of the main engine factory; it can also be seen that the low-odor compatibilizer and the deodorizer in the embodiments of the present invention have a synergistic effect during the processing process, and can effectively reduce the odor intensity of the prepared composite material by controlling the source of the odor and adsorbing the odor-containing small molecules generated during the processing.

[0127] It can be seen from Comparative Examples 7 to 8 and Example 3 that when a reactive deodorant is used, whether it is combined with a low-odor compatibilizer or a conventional compatibilizer, the obtained polypropylene composite material can meet the odor requirements, but the amount of reactive deodorant added needs to be greater, and the substances formed by the reactive deodorant during the processing may act as impurities, thereby affecting the impact strength of the material. Therefore, its comprehensive effect is not as good as the adsorption deodorant in the embodiment of the present invention.

[0128] It can be seen from Comparative Examples 9 to 10 and Examples 1 to 6 that, compared with the conventional solution, the direct yarn treated with a special sizing agent and the low-odor high-grafting compatibilizer used in Examples 1 to 6 can make the glass fiber dispersed better in the resin matrix and have a better glass fiber retention length, thereby ensuring that the mechanical strength of the prepared recycled polypropylene composite material is comparable to that of the conventional solution using new polypropylene resin. At the same time, the recycled polypropylene used in the present invention can obtain a wider melt index adjustment range through the combination of different proportions, which can meet the melt index requirements of different injection molding product structures for materials and realize customized application of materials.

[0129] It can be seen that the introduction of glass fibers with a relatively suitable monofilament diameter in the embodiment of the present invention is conducive to the good dispersion of glass fibers in the polypropylene resin substrate, thereby obtaining a longer retention length; the glass fibers specifically used in the embodiment are a thermoplastic direct yarn, which can have good compatibility with the polypropylene substrate after being treated with a specific sizing agent, and can also further improve the mechanical strength of the obtained recycled polypropylene composite material. The addition of polypropylene-maleic anhydride grafts with a high maleic anhydride grafting rate can ensure the good compatibility of glass fibers with polypropylene resin, and at the same time, it has a low maleic anhydride residue, which can reduce the impact of the introduction of polypropylene-maleic anhydride grafts as a compatibilizer on the odor and VOC of the composite material from the source. The addition of an inorganic adsorption deodorant can help the odor molecules to be better devolatilized during the processing process, ensuring that the obtained recycled polypropylene composite material can meet the odor requirements. In addition, the preparation method of the present invention is simple, the process operation is easy to implement, and the obtained recycled polypropylene composite material can meet the requirements of materials such as automobile brackets and air filters, and has good application prospects in the preparation of automobile parts.

[0130] In summary, the present invention uses recycled polypropylene material as the base material, adds less polypropylene resin, combines glass fiber, polypropylene-maleic anhydride grafted product with a high maleic anhydride grafting rate and inorganic adsorption deodorant, can ensure good compatibility between the raw materials, effectively improve the mechanical properties of the material, and make the odor molecules better devolatilize during the processing process to meet the odor requirements.

Claims

1. A recycled polypropylene composite material, characterized in that: The invention comprises the following raw materials in parts by weight: 35 to 90 parts of recycled polypropylene material, 5 to 30 parts of polypropylene resin, 10 to 50 parts of glass fiber, 1 to 10 parts of compatibilizer, 0.1 to 5 parts of deodorant, and 0.1 to 5 parts of functional additive; the compatibilizer comprises polypropylene-maleic anhydride graft, and the maleic anhydride graft rate of the polypropylene-maleic anhydride graft is 0.8 to 1.5 wt%; the deodorant comprises an inorganic adsorption type deodorant.

2. The recycled polypropylene composite material according to claim 1, characterized in that: The ash content of the recycled polypropylene material is ≤3wt%; And / or, the melt index of the recycled polypropylene material at 230° C. and 2.16 kg is 1 to 80 g / 10 min; And / or, the recycled polypropylene material is selected from homopolypropylene.

3. The recycled polypropylene composite material according to claim 1, characterized in that: The melt index of the polypropylene resin at 230° C. and 2.16 kg is 1 to 30 g / 10 min; And / or, the polypropylene resin is selected from copolymerized polypropylene.

4. The recycled polypropylene composite material according to claim 1, characterized in that: The compatibilizer is selected from polypropylene-maleic anhydride grafts; And / or, the maleic anhydride residual rate of the polypropylene-maleic anhydride graft product is 5 to 12 wt %.

5. The recycled polypropylene composite material according to claim 1, characterized in that: The deodorant is selected from inorganic adsorption type deodorants; and / or, the active ingredient of the inorganic adsorption deodorant includes a silicon-based inorganic mineral; And / or, the particle size of the inorganic adsorption deodorant is 100 to 1000 nm.

6. The recycled polypropylene composite material according to claim 1, characterized in that: The glass fiber is selected from impregnated and modified glass fibers; and / or, the monofilament diameter of the glass fiber is 10 to 25 μm; And / or, the linear density of the glass fiber is 2200-2600 g / km.

7. The recycled polypropylene composite material according to claim 1, characterized in that: The functional auxiliary agent includes an antioxidant, a lubricant or a combination thereof.

8. A method for preparing a recycled polypropylene composite material according to any one of claims 1 to 7, characterized in that: The method comprises the following steps: mixing various raw materials, and performing extrusion molding to obtain the recycled polypropylene composite material.

9. The preparation method according to claim 8, characterized in that: The processing temperature of the extrusion molding is 50 to 250°C; And / or, the extrusion molding is carried out in a screw extrusion mode, and the screw speed is 250-500r / min.

10. Use of the recycled polypropylene composite material according to any one of claims 1 to 7 in the preparation of automobile parts.

Images