High-impact polypropylene composite material with scattering effect and preparation method thereof

Abstract

The invention provides a high-impact polypropylene composite material with a scattering effect and a preparation method thereof, and relates to the field of high polymer materials. The material comprises the following components in percentage by weight: 60-70wt% of polypropylene composite resin; 18 to 24 wt.% of talcum powder; 4 to 8 wt.% of a flexibilizer; 2 to 6 wt.% of a compatilizer; 0.1 to 0.5 wt.% of a dispersant; 0.5 to 1.5 wt.% of black color master batch; 0.2 to 1 wt.% of a spot scattering material; 0.1 to 0.5 wt% of a lubricant; 0.2 to 1 wt.% of an antioxidant; 0.1 to 0.5 wt% of a light stabilizer; during preparation, the talcum powder, the black master batch, the polypropylene composite resin, the flexibilizer, the antioxidant and the lubricant are stirred and mixed to prepare matrix polypropylene, and then the scattering master batch is prepared from the scattering material, the compatilizer, the dispersing agent, the light stabilizer and the remaining components; and finally, carrying out blending injection molding on the matrix polypropylene and the scattering master batch. The formula of the polypropylene composite material with the spot scattering effect is improved, the spot scattering material in the prepared product is well combined with a polypropylene interface, and the polypropylene composite material has excellent impact resistance.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, specifically to a high-impact polypropylene composite material with a dotting effect and its preparation method. Background Technology

[0002] Polypropylene (PP) is a linear chain polymer composed of propylene monomers linked by covalent bonds. Researchers classify PP into three forms—isotactic, syndiotactic, and atactic—based on the spatial arrangement of the methyl groups in the side chains. Isotactic PP has methyl groups on the same side of the main chain plane, exhibiting a regular structure, resulting in high crystallinity, a high melting point, high hardness and stiffness, and excellent mechanical properties. Atactic PP has relatively poor performance but is often used as a carrier for filler masterbatches and is frequently used as a modification carrier. Syndiotactic PP has performance between the two, but with better impact resistance. Due to its low price and good overall performance, PP is widely used in the automotive, electronics, and other fields. In specific production, isotactic PP is selected as the main component, accounting for 95%, with the remainder being atactic or syndiotactic PP.

[0003] In practical applications, polypropylene resin requires compounding and modification to achieve better performance. For example, polypropylene compounded with carbon fiber improves the resin's strength, stiffness, and heat resistance; polypropylene compounded with elastomers modifies the resin's toughness; and polypropylene compounded with functional additives modifies the resin's flame retardancy, anti-aging properties, and antistatic properties. In recent years, consumers have increasingly focused on the appearance of polymer materials such as polypropylene, and appearance modification has received growing attention, such as surface smoothness and speckled effects. Among these, speckled effects, such as ink splattering, randomness, and varying sizes, are often achieved through spraying. To obtain a speckled effect, polypropylene materials require complex surface treatment first, followed by at least four spray coats. This spraying process is not only complex and time-consuming but also environmentally unfriendly.

[0004] Existing technologies also disclose a one-time molding technique for creating a dotted effect without spraying. This technique has advantages such as short production cycle, low overall cost, and environmental friendliness, and is gradually replacing spraying processes in multiple fields. For example, patent CN110325338B discloses a polypropylene resin composition, which is used to injection mold the molded body. The solution achieves a metallic color variation effect at different angles by adding small-particle-size aluminum powder, but the finished material produced by this solution does not have a significant dotted effect. Another example is patent CN117820764A, which discloses a paint-free filled polypropylene material composition with a dotted effect. This composition includes polypropylene resin, dotted masterbatch, talc, toughening agent, black masterbatch, antioxidant, lubricant, and colorant. It achieves a significant black background with white dotted surface effect in polypropylene with a high talc content, and displays a shimmering effect at specific angles.

[0005] With the application of spray-free polypropylene materials, it has been found that composite materials with added small-particle-size aluminum powder or aluminum flakes will experience a gradual decline in mechanical properties and poor interfacial bonding as the application time increases. Therefore, it is necessary to improve the preparation scheme of spray-free polypropylene materials with a dotting effect. Summary of the Invention

[0006] The purpose of this invention is to provide a high-impact polypropylene composite material with a speckling effect and its preparation method. By selecting the type of polypropylene and improving the overall formula, this invention solves the technical problems of gradual decline in mechanical properties and poor interfacial bonding when applying existing non-spraying polypropylene composite materials with speckling effect.

[0007] To achieve the above objectives, the present invention proposes the following technical solution: In the first aspect, a high-impact polypropylene composite material with a speckling effect is proposed, comprising, by weight percentage: polypropylene composite resin, 60-70 wt.%; talc, 18-24 wt.%; toughening agent, 4-8 wt.%; compatibilizer, 2-6 wt.%; dispersant, 0.1-0.5 wt.%; black masterbatch, 0.5-1.5 wt.%; speckling material, 0.2-1 wt.%; lubricant, 0.1-0.5 wt.%; antioxidant, 0.2-1 wt.%; and light stabilizer, 0.1-0.5 wt.%.

[0008] Furthermore, the polypropylene composite resin is a mixture of ordinary copolymer polypropylene, highly crystalline copolymer polypropylene, and high-impact polypropylene; The melt index of the ordinary copolymer polypropylene is 1~50 g / 10 min, and the weight percentage is 30~36 wt.%; the melt index of the highly crystalline copolymer polypropylene is 10~100 g / 10 min, and the weight percentage is 15~17 wt.%; the melt index of the high-impact polypropylene is 0.5~30 g / 10 min, and the weight percentage is 15~17 wt.%.

[0009] Furthermore, the dotting material is an aluminum sheet with a diameter of 20~400μm and a thickness of 0.1~2μm.

[0010] Furthermore, the compatibilizer is one or more of the following: maleic anhydride-grafted polypropylene, maleic anhydride-grafted polyethylene, maleic anhydride-grafted styrene, epoxy resin-grafted polyolefin, and acrylic acid-grafted polypropylene.

[0011] Furthermore, the toughening agent is a polyolefin elastomer (POE) or ethylene propylene diene monomer (EPDM).

[0012] Furthermore, the lubricant is zinc stearate or vinyl bis-stearamide.

[0013] Furthermore, the antioxidant is one or more of hindered phenolic antioxidants or phosphate ester antioxidants in combination; The hindered phenolic antioxidant is selected from one or more of antioxidant 264, antioxidant 1076, antioxidant 1010, antioxidant 1330, antioxidant 245, and antioxidant AO-80; the phosphate ester antioxidant is selected from one or more of antioxidant 168, antioxidant 626, antioxidant S-9228, antioxidant 618, antioxidant PEP-36, antioxidant PEPQ, antioxidant TNPP, and antioxidant 2105.

[0014] Furthermore, the dispersant is a mixture of stearic acid and paraffin in a 2:1 ratio.

[0015] Furthermore, the light stabilizer is one or more of the following: UV-3808PP5, ChemsorbTM-622, SABOUV9150PP, Tinuvin770, and Sunostable902.

[0016] Secondly, a method for preparing the aforementioned high-impact polypropylene composite material with a speckling effect is proposed, comprising the following steps: S1. Preparation of matrix polypropylene: 50% talc powder and 50% black masterbatch are mixed together, and then 50% polypropylene composite resin, 50% toughening agent, 50% antioxidant and 50% lubricant are added and mixed. The mixture is extruded and granulated by a twin-screw extruder to obtain matrix polypropylene. S2. Preparation of dotting masterbatch: Mix all the dotting materials, compatibilizer, dispersant and light stabilizer, as well as the remaining talc powder, and feed them through the side feed port. Then mix the remaining polypropylene composite resin, toughening agent, antioxidant, lubricant and black masterbatch. The mixture is extruded and granulated by a twin-screw extruder to obtain dotting masterbatch. S3. Injection molding: The matrix polypropylene and the sprinkled masterbatch are blended and injection molded; wherein, the injection temperature is 200℃~230℃ and the injection pressure is 55MPa~70MPa.

[0017] As can be seen from the above technical solutions, the technical solutions of the present invention have achieved the following beneficial effects: This invention discloses a high-impact polypropylene composite material with a speckling effect and its preparation method. The high-impact polypropylene composite material, by weight percentage, comprises: polypropylene composite resin, 60-70 wt.%; talc, 18-24 wt.%; toughening agent, 4-8 wt.%; compatibilizer, 2-6 wt.%; dispersant, 0.1-0.5 wt.%; black masterbatch, 0.5-1.5 wt.%; speckling material, 0.2-1 wt.%; lubricant, 0.1-0.5 wt.%; antioxidant, 0.2-1 wt.%; and light stabilizer, 0.1-0.5 wt.%. In preparation, firstly, talc, black masterbatch, polypropylene composite resin, toughening agent, antioxidant, and lubricant are mixed to obtain a matrix polypropylene. Then, speckling material, compatibilizer, dispersant, light stabilizer, and the remaining components are used to prepare speckling masterbatch. Finally, the matrix polypropylene and speckling masterbatch are blended and injection molded. This invention improves the formulation of a polypropylene composite material with a speckling effect by: combining a compatibilizer and a dispersant to improve the dispersion effect of the speckling material and promote the interfacial bonding between the speckling material and polypropylene; by controlling the content of the speckling material and talc, and adding a toughening agent, stress concentration in the composite material is avoided, while compensating for the loss of rigidity caused by the addition of the speckling material to the formulation, and improving the overall impact resistance of the composite material; the final product has excellent interfacial bonding between the speckling material and polypropylene and excellent impact resistance.

[0018] It should be understood that all combinations of the foregoing concepts and the additional concepts described in more detail below can be considered part of the inventive subject matter of this disclosure, provided that such concepts do not contradict each other.

[0019] The foregoing and other aspects, embodiments, and features of the teachings of the present invention will be more fully understood from the following description in conjunction with the accompanying drawings. Other additional aspects of the invention, such as features and / or beneficial effects of exemplary embodiments, will become apparent from the following description or may be learned through practice of specific embodiments according to the teachings of the present invention. Attached Figure Description

[0020] The accompanying drawings are not drawn to scale. In the drawings, each identical or nearly identical component shown in the various figures may be denoted by the same reference numeral. For clarity, not every component is labeled in each figure. Embodiments of various aspects of the invention will now be described by way of example and with reference to the accompanying drawings, wherein: Figure 1 The appearance of the high-impact polypropylene composite material with a dotting effect obtained in Example 1 of the present invention is shown. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention without creative effort are within the scope of protection of the present invention. Unless otherwise defined, the technical or scientific terms used herein should have the ordinary meaning understood by those skilled in the art.

[0022] The terms "first," "second," and similar words used in the specification and claims of this patent application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, unless the context clearly indicates otherwise, the singular forms of "an," "a," or "the," etc., do not indicate a quantity limitation, but rather indicate the presence of at least one. Terms such as "comprising" or "including" mean that the element or object preceding "comprising" encompasses the features, integrals, steps, operations, elements, and / or components listed following "comprising" or "including," and do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or collections thereof.

[0023] Existing methods for preparing polypropylene materials with a dotting effect, such as spraying, suffer from problems such as complex and time-consuming processes and environmental unfriendliness. One-time molding methods, on the other hand, suffer from poor interfacial bonding between the dotting material and polypropylene, resulting in decreased mechanical properties. Therefore, this invention aims to propose a high-impact polypropylene composite material with a dotting effect and its preparation method. By improving the formulation of the one-time molded polypropylene composite material, the defects of current one-time molded polypropylene materials with a dotting effect can be effectively improved.

[0024] Specifically, the high-impact polypropylene composite material with a speckling effect disclosed in this invention comprises, by weight percentage: polypropylene composite resin, 60-70 wt.%; talc, 18-24 wt.%; toughening agent, 4-8 wt.%; compatibilizer, 2-6 wt.%; dispersant, 0.1-0.5 wt.%; black masterbatch, 0.5-1.5 wt.%; speckling material, 0.2-1 wt.%; lubricant, 0.1-0.5 wt.%; antioxidant, 0.2-1 wt.%; and light stabilizer, 0.1-0.5 wt.%.

[0025] The polypropylene composite resin is a mixture of ordinary copolymer polypropylene, highly crystalline copolymer polypropylene, and high-impact polypropylene. The ordinary copolymer polypropylene has a melt index of 1-50 g / 10 min and a weight percentage of 30-36 wt.%, with the melt index of the ordinary copolymer polypropylene in this example being 21 g / 10 min (230°C / 2.16 kg). The highly crystalline copolymer polypropylene has a melt index of 10-100 g / 10 min and a weight percentage of 15-17 wt.%, with the melt index of the highly crystalline copolymer polypropylene in this example being 32 g / 10 min (230°C / 2.16 kg). The high-impact polypropylene has a melt index of 0.5-30 g / 10 min and a weight percentage of 15-17 wt.%, with the melt index of the high-impact polypropylene in this example being 13 g / 10 min (230°C / 2.16 kg).

[0026] The sprinkling material is an aluminum sheet with a diameter of 20-400 μm and a thickness of 0.1-2 μm. In this example, aluminum sheets with diameters of 200 μm and 400 μm are combined. The compatibilizer is one or more of maleic anhydride-grafted polypropylene, maleic anhydride-grafted polyethylene, maleic anhydride-grafted styrene, epoxy resin-grafted polyolefin, and acrylic acid-grafted polypropylene. The toughening agent is polyolefin elastomer POE or ethylene propylene diene monomer (EPDM). The lubricant is zinc stearate or vinyl bis-stearamide. The antioxidant is one or more of hindered phenolic antioxidants or phosphate ester antioxidants. The antioxidant is selected from one or more of antioxidants 264, 1076, 1010, 1330, 245, and AO-80; the phosphate ester antioxidant is selected from one or more of antioxidants 168, 626, S-9228, 618, PEP-36, PEPQ, TNPP, and 2105; the dispersant is stearic acid and paraffin in a 2:1 ratio; the light stabilizer is one or more of UV-3808PP5, ChemsorbTM-622, SABOUV9150PP, Tinuvin 770, and Sunostable 902.

[0027] The preparation method of the above-mentioned high-impact polypropylene composite material with a speckling effect includes the following steps: S1. Preparation of matrix polypropylene: 50% talc powder and 50% black masterbatch are mixed together, and then 50% polypropylene composite resin, 50% toughening agent, 50% antioxidant and 50% lubricant are added and mixed. The mixture is extruded and granulated by a twin-screw extruder to obtain matrix polypropylene. S2. Preparation of dotting masterbatch: Mix all the dotting materials, compatibilizer, dispersant and light stabilizer, as well as the remaining talc powder, and feed them through the side feed port. Then mix the remaining polypropylene composite resin, toughening agent, antioxidant, lubricant and black masterbatch. The mixture is extruded and granulated by a twin-screw extruder to obtain dotting masterbatch. S3. Injection molding: The matrix polypropylene and the sprinkled masterbatch are blended and injection molded; wherein, the injection temperature is 200℃~230℃ and the injection pressure is 55MPa~70MPa.

[0028] The high-impact polypropylene composite material with a dotting effect and its preparation method disclosed in this invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0029] Example 1 The method for preparing a high-impact polypropylene composite material with a dotting effect disclosed in this embodiment includes the following steps: S1. Preparation of PP matrix: Mix 50% talc powder and 50% black masterbatch, then add 50% polypropylene composite resin, 50% toughening agent, 50% antioxidant, and 50% lubricant and mix. Extrude and granulate the mixture using a twin-screw extruder to obtain the PP matrix. The temperature of the first zone of the twin-screw extruder is 80~120℃, the temperature of the second to fifth zones is 180~200℃, and the temperature of the other zones is 200~230℃.

[0030] S2. Preparation of dotting masterbatch: Mix all the dotting materials, compatibilizer, dispersant and light stabilizer, as well as the remaining talc powder, and feed them through the side feed port. Then mix the remaining polypropylene composite resin, toughening agent, antioxidant, lubricant and black masterbatch. The mixture is extruded and granulated by a twin-screw extruder to obtain dotting masterbatch. S3. Injection Molding: The matrix polypropylene and a small amount of masterbatch are blended and injection molded to obtain a high-impact polypropylene composite material, with an appearance as shown. Figure 1 As shown; wherein the injection temperature is 200℃~230℃ and the injection pressure is 55MPa~70MPa.

[0031] Specifically, the high-impact polypropylene composite material, by weight percentage, comprises: ordinary copolymer polypropylene, 34.3 wt.%; highly crystalline copolymer polypropylene, 16 wt.%; high-impact polypropylene, 16 wt.%; talc, 21 wt.%; toughening agent selected from polyolefin elastomer POE, 5.6 wt.%; compatibilizer selected from maleic anhydride-grafted polypropylene, 4 wt.%; dispersant, 0.4 wt.%; black masterbatch, 1 wt.%; sprinkling agent, 0.5 wt.%; lubricant selected from zinc stearate, 0.3 wt.%; antioxidant selected from antioxidant 1010 and antioxidant 168 compounded in a molar ratio of 1:1, 0.6 wt.%; and light stabilizer selected from UV-3808PP5, 0.3 wt.%.

[0032] Table 1 shows the content of different components in the formulations of Examples 1-10 and Comparative Examples 1-3.

[0033] The only difference between Examples 2-10 and Comparative Examples 1-3 and Example 1 is the content of each component in the formula, as shown in Table 1 below.

[0034] Performance tests were conducted on Examples 1-10 and Comparative Examples 1-3, including: 1) Density test: tested according to ISO 1183-2004 standard at a test temperature of 23℃; 2) Ash content test: tested according to GB / T 9345-2008 standard at a test temperature of 650℃; 3) Mechanical property test: tensile strength, flexural strength, and flexural modulus were tested according to ISO 527-2012 standard at a tensile rate of 50mm / min; cantilever beam notched impact strength was tested according to ISO 180-2019 standard with a notch type of 1eA; 4) Thermal stability test: tested according to EN ISO 4577:2019 standard at a test temperature of 150℃ for 700h.

[0035] Table 2 shows the performance data of the products obtained in Examples 1-10 and Comparative Examples 1-3.

[0036] According to the data in Table 2, the polypropylene composite material with the best overall performance in Examples 1-10 has a tensile strength of over 21 MPa, a flexural strength of over 24 MPa, a flexural modulus of over 1700 MPa, and a cantilever beam notched impact strength of 21 KJ / m. 2In addition, the aluminum flakes dispersed well as a sprinkling material in the presence of a dispersant, without any sprinkling agglomeration, indicating that the high-impact polypropylene composite material of the present invention not only possesses good mechanical properties but also has excellent sprinkling appearance. As can be seen from Examples 1-4, the use of three polypropylene blends in the present invention significantly improves the mechanical properties of the polypropylene composite material compared to using any single polypropylene. Meanwhile, as can be seen from Examples 1, Comparative Example 1, and Comparative Example 2, the absence of compatibilizers or dispersants in the formulation significantly affects the mechanical properties and appearance of the composite material, indicating poor interfacial bonding between the sprinkling material and the polypropylene.

[0037] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Those skilled in the art can make various modifications and refinements without departing from the spirit and scope of the invention. Therefore, the scope of protection of the present invention shall be determined by the claims.

Claims

1. A high-impact polypropylene composite material with a speckling effect, characterized in that, By weight percentage, it includes: polypropylene composite resin, 60-70 wt.%; talc, 18-24 wt.%; toughening agent, 4-8 wt.%; compatibilizer, 2-6 wt.%; dispersant, 0.1-0.5 wt.%; black masterbatch, 0.5-1.5 wt.%; sprinkling material, 0.2-1 wt.%; lubricant, 0.1-0.5 wt.%; antioxidant, 0.2-1 wt.%; and light stabilizer, 0.1-0.5 wt.%.

2. The high-impact polypropylene composite material with a speckling effect according to claim 1, characterized in that, The polypropylene composite resin is a mixture of ordinary copolymer polypropylene, highly crystalline copolymer polypropylene, and high-impact polypropylene; The melt index of the ordinary copolymer polypropylene is 1~50 g / 10 min, and the weight percentage is 30~36 wt.%; the melt index of the highly crystalline copolymer polypropylene is 10~100 g / 10 min, and the weight percentage is 15~17 wt.%; the melt index of the high-impact polypropylene is 0.5~30 g / 10 min, and the weight percentage is 15~17 wt.%.

3. The high-impact polypropylene composite material with a speckling effect according to claim 1, characterized in that, The dotting material is an aluminum sheet with a diameter of 20~400μm and a thickness of 0.1~2μm.

4. The high-impact polypropylene composite material with a speckling effect according to claim 1, characterized in that, The compatibilizer is one or more of the following: maleic anhydride-grafted polypropylene, maleic anhydride-grafted polyethylene, maleic anhydride-grafted styrene, epoxy resin-grafted polyolefin, and acrylic acid-grafted polypropylene.

5. The high-impact polypropylene composite material with a speckling effect according to claim 1, characterized in that, The toughening agent is a polyolefin elastomer (POE) or ethylene propylene diene monomer (EPDM) rubber.

6. The high-impact polypropylene composite material with a speckling effect according to claim 1, characterized in that, The lubricant is zinc stearate or vinyl bis-stearamide.

7. The high-impact polypropylene composite material with a speckling effect according to claim 1, characterized in that, The antioxidant is one or more of hindered phenolic antioxidants or phosphate ester antioxidants in combination; The hindered phenolic antioxidant is selected from one or more of antioxidant 264, antioxidant 1076, antioxidant 1010, antioxidant 1330, antioxidant 245, and antioxidant AO-80; the phosphate ester antioxidant is selected from one or more of antioxidant 168, antioxidant 626, antioxidant S-9228, antioxidant 618, antioxidant PEP-36, antioxidant PEPQ, antioxidant TNPP, and antioxidant 2105.

8. The high-impact polypropylene composite material with a speckling effect according to claim 1, characterized in that, The dispersant is a mixture of stearic acid and paraffin in a 2:1 ratio.

9. The high-impact polypropylene composite material with a speckling effect according to claim 1, characterized in that, The light stabilizer is one or more of the following: UV-3808PP5, ChemsorbTM-622, SABOUV9150PP, Tinuvin 770, and Sunovin 902.

10. A method for preparing a high-impact polypropylene composite material with a speckling effect as described in any one of claims 1-9, characterized in that, Includes the following steps: S1. Preparation of matrix polypropylene: 50% talc powder and 50% black masterbatch are mixed together, and then 50% polypropylene composite resin, 50% toughening agent, 50% antioxidant and 50% lubricant are added and mixed. The mixture is extruded and granulated by a twin-screw extruder to obtain matrix polypropylene. S2. Preparation of dotting masterbatch: Mix all the dotting materials, compatibilizer, dispersant and light stabilizer, as well as the remaining talc powder, and feed them through the side feed port. Then mix the remaining polypropylene composite resin, toughening agent, antioxidant, lubricant and black masterbatch. The mixture is extruded and granulated by a twin-screw extruder to obtain dotting masterbatch. S3. Injection molding: The matrix polypropylene and the sprinkled masterbatch are blended and injection molded; wherein, the injection temperature is 200℃~230℃ and the injection pressure is 55MPa~70MPa.

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