Polypropylene composite material, and preparation method and application thereof

Abstract

The application discloses a kind of polypropylene composite material and preparation method and application thereof, belong to high polymer material technical field, the polypropylene composite material, including the following weight parts of component:100 parts polypropylene resin, 14~32 parts SAN resin, 4~21 parts cycloolefin polymer, 9~16 parts hollow glass microsphere, 0.08~1.1 parts glycidyl methacrylate graft polypropylene, 0.04~0.32 parts nucleating agent.The polypropylene resin of the application is as matrix, under the joint action of SAN resin, cycloolefin polymer, hollow glass microsphere, PP-g-GMA, nucleating agent, significantly improve the coating adhesion and tensile strength of polypropylene material, the polypropylene composite material is very suitable for preparing automobile parts, especially suitable for preparing automobile bumper.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, specifically to a polypropylene composite material, its preparation method, and its application. Background Technology

[0002] Polypropylene is widely used due to its low density, high cost-effectiveness, excellent heat resistance, rigidity, resistance to chemical corrosion, and ease of processing, molding, and recycling. Therefore, it is also known as the plastic with the largest usage and fastest development rate.

[0003] After surface processing, polypropylene can be transformed into everyday products. The most common surface processing technology is spraying. Because polypropylene is a non-polar crystalline material with low surface polarity, its surface adhesion is very poor. If the surface of parts made from it is not pre-treated, it is difficult to apply paint or coating.

[0004] Therefore, this application is submitted. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the existing technology and provide a polypropylene composite material, its preparation method and application, wherein the polypropylene composite material has excellent coating adhesion and tensile strength.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A polypropylene composite material comprises the following components in parts by weight: 100 parts polypropylene resin, 14-32 parts SAN resin, 4-21 parts cyclic olefin polymer, 9-16 parts hollow glass microspheres, 0.08-1.1 parts glycidyl methacrylate grafted polypropylene, and 0.04-0.32 parts nucleating agent.

[0008] This invention creatively combines the above-mentioned raw materials, using polypropylene resin as the matrix, and with the combined action of SAN resin, cyclic olefin polymers, hollow glass microspheres, PP-g-GMA, and nucleating agents, significantly improves the coating adhesion and tensile strength of polypropylene materials. The polypropylene composite material is very suitable for manufacturing automotive parts, especially automotive bumpers.

[0009] The applicant hypothesizes that in the polypropylene resin matrix system of this invention, the addition of glycidyl methacrylate grafted polypropylene improves the polarity of the polypropylene material, effectively improving the surface polarity of polypropylene. This also enhances the compatibility of other components with the substrate, improves the migration performance of other components within the polypropylene substrate, improves the melt flowability and formability, and effectively improves processing performance. The epoxy groups of the glycidyl methacrylate interact with the polypropylene molecular chains, effectively increasing intermolecular forces. Simultaneously, the hollow glass microspheres, with their numerous hydroxyl groups on the surface, effectively improve the wetting of non-polar polypropylene materials during coating. Furthermore, the migration of the hollow glass microspheres within the matrix improves the flowability of cyclic olefin polymers and SAN resin within the polypropylene matrix, promoting their rapid migration to the surface of the polypropylene composite material to form a dense polar layer. This results in a specific crystalline network structure within the polypropylene matrix, giving it not only high paint film adhesion but also excellent tensile strength.

[0010] The amount of SAN resin used is 14 to 32 parts, for example, it can be 14 parts, 15 parts, 16 parts, 18 parts, 20 parts, 22 parts, 25 parts, 28 parts, 30 parts, 32 parts or any two of these values.

[0011] Preferably, the amount of SAN resin used is 15 to 30 parts.

[0012] The amount of the cyclic olefin polymer is 4 to 21 parts, for example, it can be 4 parts, 5 parts, 8 parts, 10 parts, 12 parts, 15 parts, 18 parts, 20 parts, 21 parts or any two of these values.

[0013] Preferably, the amount of the cyclic olefin polymer is 4 to 20 parts.

[0014] The amount of hollow glass microspheres used is 9 to 16 parts, for example, it can be 9 parts, 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, 16 parts or any two of these values.

[0015] Preferably, the amount of hollow glass microspheres used is 10 to 15 parts.

[0016] The amount of glycidyl methacrylate grafted polypropylene used is 0.08 to 1.1 parts, for example, it can be 0.08 parts, 0.1 parts, 0.2 parts, 0.4 parts, 0.6 parts, 0.8 parts, 1 part, 1.1 parts or any two of these values.

[0017] Preferably, the amount of glycidyl methacrylate grafted polypropylene is 0.1 to 1 part.

[0018] The amount of the nucleating agent is 0.04 to 0.32 parts, for example, it can be 0.04 parts, 0.05 parts, 0.08 parts, 0.1 parts, 0.15 parts, 0.2 parts, 0.25 parts, 0.3 parts, 0.32 parts, or any two of these values.

[0019] Preferably, the amount of the nucleating agent is 0.05 to 0.3 parts.

[0020] Preferably, the polypropylene composite material comprises the following components in parts by weight: 100 parts polypropylene resin, 15-30 parts SAN resin, 5-20 parts cyclic olefin polymer, 10-15 parts hollow glass microspheres, 0.1-1 parts glycidyl methacrylate grafted polypropylene, and 0.05-0.3 parts nucleating agent.

[0021] Preferably, the polypropylene composite material comprises the following components in parts by weight: 100 parts polypropylene resin, 20-25 parts SAN resin, 10-15 parts cyclic olefin polymer, 12-13 parts hollow glass microspheres, 0.5-0.8 parts glycidyl methacrylate grafted polypropylene, and 0.1-0.2 parts nucleating agent. In particular, when the amount of each raw material is within this range, the compatibility is better, and the coating adhesion and tensile strength are further improved under the combined effect of the components.

[0022] In the polypropylene composite material of the present invention, the weight percentage of the polypropylene resin is not less than 60%.

[0023] Preferably, in the polypropylene composite material of the present invention, the weight percentage of the polypropylene resin is 60-70%, for example, it can be 60%, 61%, 62%, 64%, 65%, 66%, 68%, 70%, or any two of these values.

[0024] Preferably, in the polypropylene composite material of the present invention, the weight percentage of the SAN resin is not less than 10%.

[0025] Preferably, in the polypropylene composite material of the present invention, the weight percentage of the SAN resin is not less than 10-20%, for example, it can be 10%, 11%, 12%, 14%, 15%, 16%, 18%, 20%, or any two of these values.

[0026] Preferably, the melt flow rate of the polypropylene resin at 230℃ / 2.16kg is 5 to 30 g / 10 min, for example, it can be 5 g / 10 min, 6 g / 10 min, 8 g / 10 min, 10 g / 10 min, 12 g / 10 min, 15 g / 10 min, 18 g / 10 min, 20 g / 10 min, 25 g / 10 min, 30 g / 10 min or any two of these values.

[0027] It should be noted that the source of the polypropylene resin is not limited in this invention. It can be recycled polypropylene or virgin material, as long as its melt flow rate is within the range defined in this invention.

[0028] Preferably, the polypropylene is recycled polypropylene, which is derived from at least one of washing machine drum material, ton bag material, and daily necessities. The use of recycled polypropylene can realize waste utilization, turning waste into treasure, and the recycled raw materials are easy to obtain and have low cost.

[0029] Preferably, the melt flow rate of the polypropylene resin at 230℃ / 2.16kg is 10-18g / 10min. By controlling the melt flow rate of the polypropylene resin within this range, the present invention provides better fluidity and molding effect, improves processing performance and molding effect, and is more conducive to the crystallization of polypropylene, promoting the formation of a crystalline network structure from the surface to the interior, thereby further improving coating adhesion and tensile strength.

[0030] Preferably, the acrylonitrile content in the SAN resin is 18-35 wt%, for example, it can be 18 wt%, 20 wt%, 22 wt%, 25 wt%, 28 wt%, 30 wt%, 32 wt%, 35 wt%, or any two of these values. SAN resin, also known as AS resin, is a copolymer of styrene and acrylonitrile. It has good processing fluidity and a good toughening effect. It can form a dense polar layer with other components, promoting the formation of a crystalline network structure from the surface to the interior, thereby further improving coating adhesion and tensile strength.

[0031] Preferably, the acrylonitrile content in the SAN resin is 25-30 wt%.

[0032] The SAN resin was measured to have a melt flow rate of 1.4 to 3.3 g / 10 min at 220°C / 5 kg according to ISO 1133-2011 method. For example, it could be 1.4 g / 10 min, 1.5 g / 10 min, 1.8 g / 10 min, 2 g / 10 min, 2.5 g / 10 min, 3 g / 10 min, 3.3 g / 10 min, or any two of these values.

[0033] Preferably, the true density of the hollow glass microspheres is 0.35–0.6 g / cm³. 3 For example, it could be 0.35 g / cm³. 3 0.4g / cm 3 0.42g / cm 3 0.45g / cm 3 0.46 g / cm 3 0.48g / cm 3 0.5g / cm 3 0.52g / cm 3、 0.55g / cm 3 0.6g / cm 3 Or a range consisting of any two of these values.

[0034] Preferably, the true density of the hollow glass microspheres is 0.46–0.50 g / cm³. 3 .

[0035] Preferably, the average particle size of the hollow glass microspheres is 5 to 100 μm, for example, it can be 5 μm, 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm or any two of these values.

[0036] The average particle size of the hollow glass microspheres was tested according to GB / T 19077-2016.

[0037] Preferably, the hollow glass microspheres have an average particle size of 30–50 μm.

[0038] Preferably, the glycidyl methacrylate grafting rate in the glycidyl methacrylate-grafted polypropylene is 0.2 to 1.5 wt%, for example, it can be 0.2 wt%, 0.5 wt%, 0.6 wt%, 0.8 wt%, 1 wt%, 1.2 wt%, 1.5 wt%, or any two of these values.

[0039] Preferably, the glycidyl methacrylate grafting rate in the glycidyl methacrylate-grafted polypropylene is 0.5-1 wt%. By controlling the grafting rate within this range, the coating adhesion and tensile strength are further improved. If the grafting rate is too low, the improvement effect is not good. If the grafting rate is too high, it may lead to poor flowability (resulting in poor processability) or affect the crystallization of polypropylene, thereby leading to a decline in performance.

[0040] Preferably, the nucleating agent includes at least one of α-crystal nucleating agents and β-crystal nucleating agents.

[0041] Preferably, the α-crystal nucleating agent includes at least one of aryl phosphate salt α-crystal nucleating agents, organic carboxylate salt α-crystal nucleating agents, sorbitol α-crystal nucleating agents, and rosin α-crystal nucleating agents.

[0042] The β-crystal nucleating agent includes at least one of the following: inorganic oxide β-crystal nucleating agents, inorganic salt β-crystal nucleating agents, polycyclic aromatic hydrocarbon β-crystal nucleating agents, organic carboxylic acids and their salts β-crystal nucleating agents, and aromatic amide β-crystal nucleating agents.

[0043] Preferably, the cyclic olefin polymer includes at least one of cyclic olefin copolymers and cyclic olefin homopolymers.

[0044] Preferably, the glass transition temperature of the cyclic olefin copolymer is 78 to 123°C, for example, it can be 78°C, 80°C, 85°C, 90°C, 95°C, 100°C, 105°C, 110°C, 115°C, 120°C, 123°C or any two of these values.

[0045] The glass transition temperature of the cyclic olefin copolymer was tested according to ISO 11357-2.

[0046] Preferably, the polypropylene composite material of the present invention may further include at least one of toughening agent, mineral powder, lubricant, colorant, antioxidant, weathering agent, antistatic agent, flame retardant, and ultraviolet light absorber.

[0047] The polypropylene composite material of the present invention may include toughening agents, and suitable toughening agents include, but are not limited to, ethylene-octene copolymers, SEBS, maleic anhydride-grafted POE, maleic anhydride-grafted SEBS, and combinations thereof.

[0048] The polypropylene composite material of the present invention may include mineral powder, and suitable mineral powders include, but are not limited to, calcium carbonate, mica, kaolin, magnesium hydroxide, borax, and combinations thereof.

[0049] The polypropylene composite material of the present invention may include colorants, and suitable colorants include, but are not limited to, carbon black, titanium dioxide, zinc sulfide, iron oxide red, titanium yellow, and combinations thereof.

[0050] The polypropylene composite material of the present invention may include a lubricant, and suitable lubricants include, but are not limited to, polyethylene wax, fatty acid esters, hyperbranched amides, and combinations thereof.

[0051] The polypropylene composite material of the present invention may include antioxidants, and suitable antioxidants include, but are not limited to, antioxidant 1098, antioxidant 1010, antioxidant 1076, antioxidant 168, and combinations thereof.

[0052] The polypropylene composite material of the present invention may include weathering agents, and suitable weathering agents include, but are not limited to, hindered amine light stabilizers, benzotriazole ultraviolet light absorbers, and combinations thereof.

[0053] The polypropylene composite material of the present invention may include an antistatic agent, and suitable antistatic agents include, but are not limited to, zinc oxide, manganese dioxide, chromium trioxide, and combinations thereof.

[0054] The polypropylene composite material of the present invention may include flame retardants, suitable flame retardants including but not limited to brominated polymers (e.g., brominated polystyrene), metal dialkyl phosphites (e.g., tris(diethylphosphite)aluminum), metal hydroxides (e.g., magnesium hydroxide), aromatic phosphates (e.g., resorcinol di(diphenyl phosphate) and bisphenol A di(diphenyl phosphate)) and combinations thereof.

[0055] The polypropylene composite material of the present invention may include ultraviolet light absorbers, and suitable ultraviolet light absorbers include, but are not limited to, hydroxybenzophenones, hydroxybenzotriazoles, hydroxybenzotriazines, cyanoacrylates, nanoscale inorganic materials (e.g., titanium oxide, cerium oxide, and zinc oxide), and combinations thereof.

[0056] This invention also provides a method for preparing a polypropylene composite material, comprising the following steps:

[0057] According to the specified ratio, polypropylene resin, SAN resin, cyclic olefin polymer, hollow glass microspheres, glycidyl methacrylate-grafted polypropylene, and nucleating agent are mixed evenly, melt-extruded and granulated to obtain polypropylene composite material.

[0058] Preferably, the temperature of the melt extrusion is 170–210°C.

[0059] This invention also provides an application of polypropylene composite material in the preparation of automotive parts.

[0060] The polypropylene composite material described in this invention has excellent coating adhesion and tensile strength, making it very suitable for manufacturing automotive parts, especially automotive bumpers.

[0061] The beneficial effects of this invention are as follows: This invention uses polypropylene resin as the matrix, and with the combined action of SAN resin, cyclic olefin polymers, hollow glass microspheres, PP-g-GMA, and nucleating agents, it significantly improves the coating adhesion and tensile strength of polypropylene materials. The polypropylene composite material is very suitable for manufacturing automotive parts, especially automotive bumpers. Detailed Implementation

[0062] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0063] In this application, the technical features described in an open-ended manner include both closed technical solutions consisting of the listed features and open technical solutions that include the listed features.

[0064] In this application, numerical ranges are referred to as continuous unless otherwise specified, and include the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Furthermore, when the range refers to integers, it includes every integer between the minimum and maximum values ​​of the range. Additionally, when multiple ranges are provided to describe a feature or characteristic, the ranges may be merged. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges to which they are incorporated.

[0065] The raw materials used in the examples and comparative examples are described below:

[0066] Polypropylene Resin-1: Recycled polypropylene, with the base material in ton bags. The melt flow rate was measured to be 10.0 g / 10 min at 230℃ / 2.16 kg.

[0067] Polypropylene Resin-2: Recycled polypropylene, sourced from Japanese miscellaneous materials, with a melt flow rate of 18.0 g / 10 min measured at 230℃ / 2.16 kg.

[0068] Polypropylene Resin-3: Recycled polypropylene, sourced from washing machine drum material, with a melt flow rate of 30.0 g / 10 min measured at 230℃ / 2.16 kg.

[0069] Polypropylene Resin-4: Recycled polypropylene, sourced from Japanese miscellaneous materials, with a melt flow rate of 5.0 g / 10 min measured at 230℃ / 2.16 kg.

[0070] Polypropylene resin-5: The melt flow rate was measured to be 10 g / 10 min at 230℃ / 2.16 kg. It was purchased from Sinopec and its grade is PP EP300M.

[0071] SAN Resin-1: Acrylonitrile content is 30wt%, Kumho Chemical, grade SAN 350N.

[0072] SAN Resin-2: Acrylonitrile content is 25wt%, grade SAN NF2200AE.

[0073] SAN Resin-3: Acrylonitrile content is 35wt%, Kumho Chemical, grade SAN 350N HW.

[0074] SAN Resin-4: Acrylonitrile content is 18wt%, Kumho Chemical, grade SAN 310TR.

[0075] PP-g-GMA-1: Glyceryl methacrylate-grafted polypropylene, with a glyceryl methacrylate grafting rate of 1%, self-made.

[0076] PP-g-GMA-2: Glycidyl methacrylate-grafted polypropylene, with a glycidyl methacrylate grafting rate of 0.5%, self-made.

[0077] PP-g-GMA-3: Glycidyl methacrylate-grafted polypropylene, with a glycidyl methacrylate grafting rate of 0.2%, self-made.

[0078] PP-g-GMA-4: Glycidyl methacrylate-grafted polypropylene, with a glycidyl methacrylate grafting rate of 1.5%, self-made.

[0079] PP-g-GMA-5: Glyceryl methacrylate-grafted polypropylene, with a glyceryl methacrylate grafting rate of 1%, Guangzhou Dongjin Plastics Technology Co., Ltd., grade PPG-2321.

[0080] PP-g-MAH: Maleic anhydride-grafted polypropylene, with a maleic anhydride grafting rate of 1%, self-made.

[0081] Hollow glass microspheres-1: True density is 0.46 g / cm³ 3 Zhengzhou Shenglait Hollow Glass Microsphere New Material Co., Ltd., Grade HL46.

[0082] Hollow glass microspheres-2: True density is 0.50 g / cm³ 3 Zhengzhou Shenglait Hollow Glass Microspheres New Material Co., Ltd., Grade HL50.

[0083] Hollow glass microspheres-3: True density is 0.6 g / cm³ 3 Zhengzhou Shenglait Hollow Glass Microspheres New Material Co., Ltd., Grade HL60.

[0084] Hollow glass microspheres-4: True density is 0.35 g / cm³ 3 Zhengzhou Shenglait Hollow Glass Microsphere New Material Co., Ltd., Grade HL35.

[0085] Cyclic olefin polymers-1: Cyclic olefin copolymers, Polyplastics Japan, brand name TOPAS 8007F-04.

[0086] Cyclic olefin polymer-2: Cyclic olefin copolymer, Zeon Corporation of Japan, brand name ZEONEX 330R.

[0087] Cyclic olefin polymers-3: Cyclic olefin homopolymers, Zeon Corporation of Japan, brand name ZEONOR 1020R.

[0088] Nucleating agent-1: Aryl phosphate salt α-crystal nucleating agent, Shanxi Chemical Research Institute, brand name TMP-6.

[0089] Nucleating agent-2: Organic carboxylate α-crystal nucleating agent, Milken Corporation, brand name HPN-68L.

[0090] Nucleating Agent-3: Aromatic amide β-crystal nucleating agent, Shanxi Chemical Research Institute, grade TMB-5.

[0091] Talc powder: Tianyuan Company, brand name TYT-777A.

[0092] The preparation methods of PP-g-GMA-1 to 4 all include the following steps:

[0093] Dicumyl peroxide (1 wt% of polypropylene) was dissolved in glycidyl methacrylate, then mixed evenly with polypropylene. The mixture was then react-extruded through a twin-screw extruder at a screw temperature of 165–200 °C to obtain polypropylene grafted with glycidyl methacrylate (PP-g-GMA).

[0094] By controlling the ratio of glycidyl methacrylate to polypropylene, the grafting rate of glycidyl methacrylate can be controlled, resulting in PP-g-GMA-1 to 4 with different grafting rates.

[0095] The preparation method of PP-g-MAH is the same as that of PP-g-GMA, except that GMA is replaced with MAH.

[0096] The testing standards for raw material parameters are as follows:

[0097] In this invention, the melt flow rate of polypropylene resin was measured according to the ISO 1133-2011 method at 230°C / 2.16 kg.

[0098] In this invention, the acrylonitrile content in SAN resin can be determined by elemental analysis, such as using the high-temperature combustion method to analyze the content of conventional organic elements in the sample. The elements to be measured are carbon (C), hydrogen (H), and nitrogen (N). The test conditions can be selected as follows: sample weight: 2 mg, decomposition temperature: 950-1200℃, analysis time: simultaneous determination of C, H, and N for 6-9 minutes.

[0099] In this invention, the method for testing the glycidyl methacrylate grafting rate in glycidyl methacrylate-grafted polypropylene is as follows: Before testing the grafting rate, PP-g-GMA needs to be purified. 5g of the PP-g-GMA sample is dissolved in 150mL of hot xylene (above 110°C), and poured into 200mL of acetone. Unreacted GMA monomer and GMA homopolymer are dissolved in acetone, and the precipitate is purified PP-g-GMA. 1g of purified PP-g-GMA is dissolved in 70mL of hot xylene (above 110°C), and 4mL of 0.1mol / L trichloroacetic acid xylene solution is added. The solution is then heated at 130°C. Reflux at ~135℃ for 90 min to fully open the epoxy groups on GMA. Titrate with 0.05 mol / L KOH methanol solution using phenolphthalein as an indicator. Calculate the grafting rate based on the amount of KOH methanol solution consumed: Grafting rate Gd = 142.15 * (V0 - V) * c / (1000 * m), where V0 is the volume (mL) of KOH methanol solution consumed in titrating ungrafted PP, V is the volume (mL) of KOH methanol solution consumed in titrating grafted PP, c is the molar concentration of KOH, m is the mass of PP-g-GMA being titrated, and 142.15 is the molecular weight of GMA.

[0100] The density of hollow glass microspheres was tested according to the method in GB / T 21782.3-2008.

[0101] Unless otherwise specified, all components and raw materials used in the embodiments and comparative examples of this invention are commercially available, and the same type of components and raw materials are used in each parallel experiment.

[0102] Examples 1-22, Comparative Examples 1-7

[0103] The formulations of the polypropylene composite materials of Examples 1-22 and Comparative Examples 1-7 are shown in Tables 1 and 2 (all figures are parts by weight).

[0104] The preparation methods of the polypropylene composite materials in Examples 1-22 and Comparative Examples 1-7 all include the following steps:

[0105] According to the formula, polypropylene resin, SAN resin, cyclic olefin polymer, hollow glass microspheres, glycidyl methacrylate grafted polypropylene, and nucleating agent are mixed evenly, and then melt-extruded and granulated at 170-210℃ to obtain polypropylene composite material.

[0106] Table 1

[0107]

[0108]

[0109] Table 2

[0110]

[0111] Performance testing

[0112] 1. Coating adhesion

[0113] 1.1 Peel Strength: The polypropylene composition prepared above was injection molded into a 100*100*2mm square plate sample. A primer was sequentially sprayed onto the plate, baked at 80℃ for 5 min, followed by a color coat and baking at 80℃ for 5 min. A clear varnish was then sprayed on and baked at 80℃ for 30 min, resulting in the painted coating. The tensile strength of the coating peeling from the surface of the material was measured. The final test result was the average of three measurements, with the peel strength unit being N / m. The test tensile speed was 50 mm / min, the peel width was 10 mm, the peel angle was 180°, and the test temperature was 23℃.

[0114] 1.2 High-pressure water jetting: The test was conducted according to the method in DIN55662-2009, with the following parameters: angle: 90°, water temperature: 60℃, distance: 100cm, time: 60s, and water flow rate: 11.3L / min. The results were compared with the standard image in DIN55662-2009 and rated. The lower the rating, the better the coating adhesion.

[0115] 2. Tensile strength properties: Tested according to ISO 527-2-2012 at a rate of 10 mm / min.

[0116] Table 3

[0117]

[0118]

[0119] As can be seen from Table 3, the polypropylene composite material of the present invention has excellent coating adhesion and tensile strength. The water wash resistance grade of the polypropylene composite material of the present invention is ≤1, the peel strength is ≥850N / m, and the tensile strength is ≥33.6MPA.

[0120] Comparing Example 2 with Comparative Examples 1-7, it can be seen that the present invention uses polypropylene resin as the matrix, and with the combined action of SAN resin, cyclic olefin polymers, hollow glass microspheres, PP-g-GMA, and nucleating agent, the coating adhesion and tensile strength of polypropylene materials are significantly improved. The absence of the raw materials or the use of other raw materials will lead to a significant decrease in coating adhesion and tensile strength.

[0121] As can be seen from Examples 1 and 4 and Examples 2-3, by controlling the weight parts of each raw material as follows: 100 parts polypropylene resin, 20-25 parts SAN resin, 10-15 parts cyclic olefin polymer, 12-13 parts hollow glass microspheres, 0.5-0.8 parts glycidyl methacrylate grafted polypropylene, and 0.1-0.2 parts nucleating agent, the coating adhesion and tensile strength are further improved.

[0122] Comparing Examples 2 with Examples 5-8, it can be seen that the present invention further improves coating adhesion and tensile strength by controlling the melt flow rate of polypropylene resin to 10-18 g / 10 min.

[0123] Comparing Examples 2 with Examples 9-11, it can be seen that the present invention further improves coating adhesion and tensile strength by controlling the acrylonitrile content in SAN resin to 25-30 wt%.

[0124] Comparing Example 2 with Examples 12-14, it can be seen that the present invention controls the true density of the hollow glass microspheres to be 0.46-0.5 g / cm³. 3 This further improves coating adhesion and tensile strength.

[0125] Comparing Example 2 with Examples 17-19, it can be seen that the present invention further improves coating adhesion and tensile strength by controlling the grafting rate of GMA in PP-g-GMA to 0.5-1wt%.

[0126] Comparing Example 2 with Examples 21-22, it can be seen that the α-crystal nucleating agent used in this invention can further improve coating adhesion and tensile strength.

[0127] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A polypropylene composite material having high paint adhesion, characterized by, The polypropylene composite material comprises the following components by weight: 100 parts of a polypropylene resin, 15-30 parts of a SAN resin, 5-20 parts of a cyclic olefin polymer, 10-15 parts of hollow glass microbeads, 0.1-1 part of a glycidyl methacrylate grafted polypropylene, and 0.05-0.3 part of a nucleating agent; the polypropylene resin has a melt flow rate of 5-30 g / 10 min at 230 ℃ / 2.16 kg; the SAN resin has an acrylonitrile content of 18-35 wt%; the glycidyl methacrylate grafted polypropylene has a grafting rate of glycidyl methacrylate of 0.2-1.5 wt%.

2. The polypropylene composite of claim 1, wherein, The polypropylene resin has a melt flow rate of 10-18 g / 10 min at 230 ℃ / 2.16 kg.

3. The polypropylene composite of claim 1, wherein, The SAN resin has an acrylonitrile content of 25-30 wt%.

4. The polypropylene composite of claim 1, wherein, The hollow glass microsphere has a true density of 0.35-0.6 g / cm 3 .

5. The polypropylene composite of claim 4, wherein, The true density of the hollow glass microsphere is 0.46~0.50g / cm 3 .

6. The polypropylene composite of claim 1, wherein, The glycidyl methacrylate grafted polypropylene has a grafting rate of glycidyl methacrylate of 0.5-1 wt%.

7. The polypropylene composite of claim 1, wherein, The nucleating agent comprises at least one of an α crystal form nucleating agent and a β crystal form nucleating agent.

8. The polypropylene composite of claim 7, wherein, The α crystal form nucleating agent comprises at least one of an aryl phosphate salt α crystal form nucleating agent, an organic carboxylic acid salt α crystal form nucleating agent, a sorbitol α crystal form nucleating agent, and a rosin α crystal form nucleating agent; and / or The β crystal form nucleating agent comprises at least one of an inorganic oxide β crystal form nucleating agent, an inorganic salt β crystal form nucleating agent, a condensed ring aromatic hydrocarbon β crystal form nucleating agent, an organic carboxylic acid and its salt β crystal form nucleating agent, and an aromatic amide β crystal form nucleating agent.

9. The polypropylene composite of claim 1, wherein, The cyclic olefin polymer comprises at least one of a cyclic olefin copolymer and a cyclic olefin homopolymer.

10. Process for the production of a polypropylene composite material according to any one of claims 1 to 9, characterized in that The method comprises the following steps: According to the ratio, the polypropylene resin, the SAN resin, the cyclic olefin polymer, the hollow glass microbeads, the glycidyl methacrylate grafted polypropylene, and the nucleating agent are uniformly mixed, melt-extruded and granulated to obtain the polypropylene composite material.

11. Use of the polypropylene composite material according to any one of claims 1-9 in the preparation of automobile parts.

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