Polypropylene composite material with melting point gradient structure, and preparation method and system thereof and application

Abstract

This invention relates to polypropylene composite materials with melting point gradient structures, their preparation methods and systems, and applications. The composite material comprises multiple sequentially stacked polypropylene sheet unit groups; each polypropylene sheet unit group includes at least one identical or different polypropylene sheet unit, and each polypropylene sheet unit has a structure of B. i A i B' i The structure of the polypropylene composite material is as follows: ... Group i ... Group 2, Group 1, Group 2 ... Group i ...; Polypropylene composition A i The melting point is greater than that of polypropylene composition B. i B' i The melting point of the polypropylene composite material with a melting point gradient structure is greater than that of the average melting point of all outer layers in the i-th group than that of all outer layers in the (i-1)-th group. The polypropylene composite material with a melting point gradient structure of the present invention exhibits both excellent tensile and impact resistance, as well as good interlaminar peel strength at relatively low hot-pressing temperatures.

Description

Technical Field

[0001] This invention relates to a polypropylene composite material, and more specifically, to a polypropylene composite material with a melting point gradient structure, its preparation method and system, and its applications. Background Technology

[0002] In recent years, high-strength and high-impact polymer composites, especially self-reinforced polymer composites, which are easy to recycle and lightweight, have become one of the hot topics of research.

[0003] In self-reinforced polymer composites, the reinforcing phase and matrix are composed of the same polymer but in different forms. The reinforcing phase is typically highly oriented fibers or ribbons. Most self-reinforced polymer composites are prepared using a hot-pressing method. When the reinforcing phase is hot-pressed under certain pressure and temperature, the surface of the reinforcing phase fibers melts to become the matrix melt. The matrix melt and the surface of the reinforcing phase co-crystallize during melting, thus providing sufficient interfacial bond strength.

[0004] For example, in US8021592B2, melt-spun oriented polyolefin fibers with a weight-average molecular weight of less than 250,000 are woven and then hot-pressed. This method utilizes specific high temperatures, pressures, and cooling times to partially melt and bond the surface layer of the polyolefin fabric to prepare a polyolefin board. This preparation method is sensitive to the temperature of the hot pressing process, requiring high temperatures. After hot pressing, the oriented fibers in the resulting composite polyolefin fibers undergo significant decomposition and orientation, resulting in a marked decrease in mechanical strength. The self-reinforcing effect needs further improvement.

[0005] To broaden the hot-pressing window and reduce the hot-pressing pressure, US8133537B2 describes the hot-pressing of three layers of polyolefin fibers with different melting points to obtain a polyolefin composite material. The melting temperatures of the first and second polyolefin layers are lower than those of the core layer, and it is emphasized that the viscosity of the second polymer is no more than approximately 10% of the viscosity of the first polymer measured at 170°C. However, hot-pressed composite materials produced by this method have relatively low impact strength and interlaminar peel strength, and cannot achieve both good mechanical properties and high interlaminar peel strength. Summary of the Invention

[0006] The purpose of this invention is to overcome the technical problem that existing polypropylene composite materials often fail to simultaneously possess a wide processing temperature range, strong mechanical properties, and high interlaminar peel strength. This invention provides a polypropylene composite material with a melting point gradient structure, its preparation method and system, and its applications through the design of a melting point gradient structure in laminated polypropylene. This preparation method can reduce hot-pressing operation time, while improving production efficiency and reducing energy consumption. The polypropylene composite material obtained by this method exhibits excellent mechanical properties and good interlaminar peel strength.

[0007] One of the objectives of this invention is to provide a polypropylene composite material.

[0008] It comprises multiple sequentially stacked groups of polypropylene sheet units; each group of polypropylene sheet units includes at least one identical or different polypropylene sheet unit, and each polypropylene sheet unit includes a core layer A. i and located in core layer A i Outer B on both sides i B' i The structure is B i A i B' i The structure of the polypropylene composite material, from bottom to top, is group n...group i...group 2, group 1, group 2...group i...group n, and the total number of polypropylene sheet unit stacks is 2n-1; i and n are both integers not less than 2, and i≤n; wherein, the core layer A in the polypropylene sheet unit... i Composition A containing polypropylene i Outer layer B i With outer layer B' i Whether the composition is the same or different, each composition corresponds to a polypropylene composition B. i Polypropylene composition B' i The polypropylene composition A i The melting point is greater than that of the polypropylene composition B. i The polypropylene composition B' i The melting point of the outermost layer in the i-th group is greater than the average melting point of the outermost layer in the (i-1)-th group.

[0009] According to the present invention, in the structure of the polypropylene composite material, the upper i-th group and the lower i-th group may be the same or different.

[0010] In a preferred embodiment of the present invention, polypropylene composition A i The melting point of polypropylene composition B i The difference in melting points, polypropylene composition A i The melting point of polypropylene composition B' i The difference in melting point is greater than or equal to 5°C, preferably greater than or equal to 10°C, more preferably greater than or equal to 20°C; and even more preferably 20-60°C.

[0011] According to the present invention, the core layer in each polypropylene sheet unit can be the same material or different materials. The present invention does not impose any particular limitation on this, as long as A... i The melting point is greater than that of the polypropylene composition B. i Polypropylene composition B' i The melting points of all these factors can achieve better technical results.

[0012] In a preferred embodiment of the present invention, the difference between the average melting point of all outer layers in the i-th group and the average melting point of all outer layers in the (i-1)-th group is the same or different, and is 1-40°C, preferably 1-10°C, and more preferably 1-5°C.

[0013] According to the present invention, the total number of polypropylene sheet unit groups is 2n-1. The present invention has a wide range of options for the total number of polypropylene sheet unit groups. In a preferred embodiment of the present invention, 2≤n≤100, more preferably, 2≤n≤50, and even more preferably, 2≤n≤30.

[0014] According to the present invention, the number of polypropylene sheet units included in each polypropylene sheet unit group can be selected within a wide range. In a preferred embodiment of the present invention, each polypropylene sheet unit group independently includes 1 to 10, preferably 1 to 5, more preferably 1 to 3 identical or different polypropylene sheet units, and even more preferably 1 polypropylene sheet unit. Preferably, the number of polypropylene sheet units included in each polypropylene sheet unit group is the same.

[0015] Preferably, but not necessarily, the melting point of any outer layer in each group is within ±10°C, ±5°C, more preferably within ±3°C, and more preferably within ±1°C of the average melting point of all outer layers in the group.

[0016] In embodiments where each polypropylene sheet unit group comprises only one polypropylene sheet unit, for example, the structure of the polypropylene composite material can be arranged from bottom to top as B n A n B' n ...B i A i B' i ...B2A2B'2, B1A1B'1, B2A2B'2...B i A i B' i ...B n A n B' n The total number of layers in the polypropylene sheet unit is 2n-1; i and n are both integers not less than 2, and i≤n.

[0017] In embodiments where each polypropylene sheet unit group comprises two or more polypropylene sheet units, for example, the structure of the i-th polypropylene sheet unit group is B. i1 A i1 B' i1 B i2 A i2 B' i2 ...B ip A ip B'ip The structure of the polypropylene composite material can be arranged from bottom to top as follows: (B) n1 A n1 B' n1 B n2 A n2 B' n2 ...B nq A nq B' nq )……(B i1 A i1 B' i1 B i2 A i2 B' i2 ...B ip A ip B' ip )……(B 21 A 21 B' 21 B 22 A 22 B' 22 ...B 2k A 2k B' 2k (B) 11 A 11 B' 11 B 12 A 12 B' 12 ...B 1j A 1j B' 1j (B) 21 A 21 B' 21 B 22 A 22 B' 22 ...B 2k A 2k B' 2k )……(B i1 A i1 B' i1 B i2 A i2 B' i2 ...B ip A ip B' ip )……(B n1 A n1 B' n1 B n2 A n2 B' n2 ...B nq A nq B' nqThe total number of polypropylene sheet units stacked is j+2k+……2p+……2q; j, k, p, and q are each independent integers not less than 2, preferably 2 to 10, more preferably 2 to 5, and even more preferably 2 to 3.

[0018] In a preferred embodiment of the present invention, the polypropylene sheet unit further includes an intermediate layer C. i C' i The polypropylene sheet unit structure is B. i C i A i C' i B' i Intermediate layer C i With intermediate layer C' i Whether the composition is the same or different, each composition contains polypropylene composition C. i Polypropylene composition C' i The polypropylene composition A i The melting point is greater than that of the polypropylene composition C. i The polypropylene composition C' i Its melting point.

[0019] According to the present invention, in each polypropylene sheet unit, the core layer A i The thickness ratio can be selected over a wide range. In a preferred embodiment of the present invention, based on the total thickness of each polypropylene sheet unit, the core layer A in each polypropylene sheet unit... i The thickness accounts for 51%-89% of the total thickness, preferably 71%-89%, and more preferably 71%-80%. Core layer A i Outer B on both sides i and B' i The thickness can be the same or different, but the same is preferred. Core layer A i The middle layer C on both sides i and C' i The thickness can be the same or different, but the same is preferred.

[0020] The thickness of each polypropylene sheet unit has a wide range of options. In a preferred embodiment of the present invention, the thickness of each polypropylene sheet unit is 10-1000 μm, preferably 30-500 μm, and more preferably 50-300 μm.

[0021] According to the present invention, core layer A i Outer layer B i B i '、Intermediate layer C i C' i The thickness can be controlled by the melt pump in the extruder during the processing.

[0022] According to the present invention, polypropylene composition A i Including but not limited to one or more of homopolymer polypropylene, random copolymer polypropylene, and impact copolymer polypropylene; polypropylene composition B i B' i Each includes, but is not limited to, one or more of homopolymer polypropylene, random copolymer polypropylene, and impact copolymer polypropylene, and optionally a thermal bonding enhancer. i Polypropylene composition C i C' i Each includes, but is not limited to, one or more of homopolymer polypropylene, random copolymer polypropylene, and impact copolymer polypropylene, and optionally a thermal bonding enhancer. i .

[0023] According to the present invention, the polypropylene composition A i The range of materials is relatively wide. In a preferred embodiment of the present invention, the polypropylene composition A... i This includes one or more of homopolymer polypropylene, random copolymer polypropylene, and impact copolymer polypropylene.

[0024] According to the present invention, the polypropylene composition B i B' i Each comprises one or more of homopolymer polypropylene, random copolymer polypropylene, and impact copolymer polypropylene; preferably, the polypropylene composition B i and / or polypropylene composition B' i It also contains thermal bonding enhancer y i .

[0025] According to the present invention, the polypropylene composition C i C' i Each comprises one or more of homopolymer polypropylene, random copolymer polypropylene, and impact copolymer polypropylene; preferably, the polypropylene composition C i and / or polypropylene composition C' i It also contains thermal bonding enhancer z i .

[0026] In a more preferred embodiment of the present invention, polypropylene composition A i Including homopolymer polypropylene a i Impact-resistant copolymer polypropylene b i In a further, more preferred embodiment of the invention, the polypropylene composition A is used. i Based on the total weight, the polypropylene composition A i Includes 50-99 wt% homopolymer polypropylene a i 1-50wt% impact-resistant copolymer polypropylene b i Further preferably, the polypropylene composition Ai Includes 70-90 wt% homopolymer polypropylene a i 10-30wt% impact-resistant copolymer polypropylene b i .

[0027] In a more preferred embodiment of the present invention, the polypropylene composition B i The polypropylene composition B' i Each includes random copolymer polypropylene x i and thermal bonding enhancer y i Preferably, the polypropylene composition B is used. i The polypropylene composition B' i Based on their respective total weights, the polypropylene composition B i The polypropylene composition B' i Each comprises 70-99 wt% random copolymer polypropylene. i 1-30wt% thermal bonding enhancer i Preferably, the polypropylene composition B i Includes 80-90 wt% random copolymer polypropylene x i 10-20wt% of thermal bonding reinforcing agent i .

[0028] In a more preferred embodiment of the present invention, the polypropylene composition C i The polypropylene composition C' i Each includes random copolymer polypropylene β i and homopolymer polypropylene γ i and thermal bonding enhancer z i Preferably, the polypropylene composition C i The polypropylene composition C' i Based on their respective total weights, the polypropylene composition C i The polypropylene composition C' i Each contains 30-60 wt% of thermal bonding reinforcing agent. i 35-55 wt% random copolymer polypropylene β i and 5-15 wt% homopolymer polypropylene γ i Further preferably, the polypropylene composition C i The polypropylene composition C' i Each contains 35-55 wt% of thermal bonding reinforcement. i 40-55 wt% random copolymer polypropylene β i and 5-10 wt% homopolymer polypropylene γ i .

[0029] According to the present invention, the homopolymer polypropylene a i With a wide range of choices, in a preferred embodiment of the present invention, the homopolymer polypropylene a i The melting point is 150-170℃, preferably 160-170℃, and / or the isotacticity (mm) is not less than 96%, preferably not less than 97%, and more preferably not less than 98%.

[0030] According to the present invention, the homopolymer polypropylene a i The melt flow rate has a wide selection range. Preferably, the homopolymer polypropylene a i The melt flow rate at 230℃ and 2.16kg load is 0.5-50g / 10min, preferably 1-20g / 10min, and more preferably 2.5-18g / 10min.

[0031] According to the present invention, "and / or" refers to either a single condition or a combination of two conditions.

[0032] According to the present invention, the impact-resistant copolymer polypropylene b i With a wide range of options, in a preferred embodiment of the present invention, the impact-resistant copolymer polypropylene b i The melting point is 150-170℃, the monomer of the impact-resistant copolymer polypropylene copolymerized with propylene is ethylene or butene, selected as butene, and / or, the cantilever beam impact strength of the impact-resistant copolymer polypropylene is not less than 20KJ / m. 2 (23℃).

[0033] According to the present invention, the impact-resistant copolymer polypropylene b i The melt flow rate has a wide selection range. Preferably, the impact-resistant copolymer polypropylene b i The melt flow rate at 230℃ and 2.16kg load is 0.5-50g / 10min, preferably 1-20g / 10min, and more preferably 2.5-18g / 10min.

[0034] According to the inventor's research, when polypropylene composition A i When the melt flow rate and polymer composition ratio of the raw materials used are within the preferred range, the impact-resistant copolymer polypropylene b in the composition... i It can effectively absorb impact energy, meeting the requirements for impact performance and giving the sheet material good impact resistance. Meanwhile, due to the homopolymer polypropylene a... i The medium and large molecular chains are relatively regular and crystallize during the sheet preparation process, thus the sheet also has good tensile properties.

[0035] In a preferred embodiment of the present invention, the polypropylene composition A iIt also includes a β-crystal nucleating agent; preferably, the β-crystal nucleating agent is selected from at least one of polycyclic aromatic hydrocarbons, group IIA two-component complexes, aromatic diamides, rare earth compounds and cyclic dicarboxylate nucleating agents.

[0036] According to the present invention, the amount of β-crystal nucleating agent can be selected over a wide range. Preferably, the amount of β-crystal nucleating agent is selected from the polypropylene composition A. i The total amount is 100 parts by weight, of the polypropylene composition A i The content of the β-crystal nucleating agent is 0.01-0.5 parts by weight. Specifically, for example, the content of the β-crystal nucleating agent can be 0.01, 0.05, 0.1, 0.2, 0.3, 0.4, or 0.5 parts by weight.

[0037] In a preferred embodiment of the present invention, the random copolymer polypropylene x i The melting point is 110-150℃, preferably 120-140℃. More preferably, the average melting point of all random copolymer polypropylenes in group i is greater than the average melting point of all random copolymer polypropylenes in group i-1. Preferably, the difference in melting points is 1-40℃, more preferably 1-10℃, and most preferably 1-5℃. Preferably, the random copolymer polypropylene x... i It is a copolymer of propylene with ethylene and / or butene, preferably an ethylene-propylene-butene terpolymer and / or a propylene-ethylene binary copolymer.

[0038] According to the present invention, the random copolymer polypropylene x i The melt flow rate has a wide selection range. Preferably, at 230℃ and a load of 2.16 kg, the melt flow rate is 0.5-50 g / 10 min, more preferably 1-20 g / 10 min, and even more preferably 3-18 g / 10 min. The random copolymer polypropylene x i The molecular weight distribution Mw / Mn is 5-12, preferably 7-10.

[0039] In a preferred embodiment of the present invention, the heat-reducing adhesive y i The melting point or viscous flow temperature is 70-110℃. And / or, the thermal adhesion enhancer y i The agent is selected from one or more of polyolefin elastomers, ethylene propylene diene monomer (EPDM) rubber, SEBS, SBS, EVA, and petroleum resins; preferably, the thermal bonding reinforcing agent y i It is a polyolefin elastomer and / or petroleum resin.

[0040] In a preferred embodiment of the present invention, the polyolefin elastomer is preferably a copolymer elastomer of ethylene and propylene and / or α-olefin, wherein the α-olefin is preferably a C4-C12 α-olefin, more preferably 1-butene and / or 1-octene; and / or, the petroleum resin is a C5 and / or C9 hydrogenated petroleum resin with a softening point of 100-150°C; preferably a cyclopentadiene type resin.

[0041] According to the present invention, the thermal bonding enhancer y i The melt flow rate has a wide selection range; preferably, the thermal adhesion enhancer y i The melt flow rate at 190℃ and 2.16kg load is 0.5-50g / 10min, preferably 1-20g / 10min, more preferably 1-18g / 10min, and even more preferably 3-18g / 10min.

[0042] According to the inventor's research, when polypropylene composition B i and polypropylene composition B' i When the respective polymer composition ratios are within the above-mentioned preferred ranges, the low-melting-point random copolymer polypropylene x in the composition i and thermal bonding enhancer y i It can significantly reduce hot-pressing temperature and widen the hot-pressing temperature window, and the thermal bonding enhancer y i It provides good adhesion to the sheet and further improves the interlayer peel strength.

[0043] According to the inventor's research, when polypropylene composition A i Combination B with polypropylene i and polypropylene composition B' i Their respective polymer composition ratios and polymer composition A i When the thickness distribution is within the above-mentioned preferred range, the sheet preparation process can be made more stable, thereby giving the sheet better uniformity, tensile strength, impact performance and interlayer peel strength.

[0044] According to the present invention, in the polypropylene sheet unit B i C i A i C' i B' i In a layered structure, the thickness ratio of each layer can be selected over a wide range. In a preferred embodiment of the present invention, the total thickness of the polypropylene sheet unit is used as a reference, and the core layer A... i The thickness of the intermediate layer accounts for 51%-89% of the total thickness, preferably 71%-89%; i C' i The thickness of the outer layer B accounts for 6%-20% of the total thickness, preferably 6%-15%;i B' i The thickness accounts for 5%-30% of the total thickness, preferably 5%-15%.

[0045] According to the present invention, the random copolymer polypropylene β i The range of materials that can be selected is relatively wide. In a preferred embodiment of the present invention, the random copolymer polypropylene β i The melting point is 110-150℃, preferably 120-140℃; and / or, the random copolymer polypropylene β i The melt flow rate at 230°C and 2.16 kg load is 0.5-50 g / 10 min, preferably 1-20 g / 10 min, and more preferably 3-18 g / 10 min; and / or, the random copolymer polypropylene β i The molecular weight distribution Mw / Mn is 5-12, preferably 7-10. Preferably, the atactic polypropylene β... i It is a copolymer of propylene with ethylene and / or butene, preferably an ethylene-propylene-butene terpolymer and / or a propylene-ethylene binary copolymer.

[0046] According to the present invention, the homopolymer polypropylene γ i The range of materials that can be selected is relatively wide. In a preferred embodiment of the present invention, the homopolymer polypropylene γ i The melting point is 150-170℃, preferably 160-170℃; and / or, the homopolymer polypropylene γ i The melt flow rate at 230°C and 2.16 kg load is 0.5-50 g / 10 min, preferably 1-20 g / 10 min, and more preferably 2.5-18 g / 10 min; and / or, the homopolymer polypropylene γ i The isotacticity (mm) is not less than 96%.

[0047] In a preferred embodiment of the present invention, the heat-reducing adhesive z i The melting point or viscous flow temperature is 70-110℃. And / or, the thermal adhesion enhancer z i It is selected from one or more of polyolefin elastomers, ethylene propylene diene monomer (EPDM) rubber, SEBS, SBS, EVA, and petroleum resins; preferably, the thermal bonding reinforcing agent z i It is a polyolefin elastomer and / or petroleum resin.

[0048] In a preferred embodiment of the present invention, the polyolefin elastomer is preferably a copolymer elastomer of ethylene and propylene and / or α-olefin, wherein the α-olefin is preferably a C4-C12 α-olefin, more preferably 1-butene and / or 1-octene; and / or, the petroleum resin is a C5 and / or C9 hydrogenated petroleum resin with a softening point of 100-150°C; preferably a cyclopentadiene type resin.

[0049] According to the present invention, the thermal bonding enhancer z i The melt flow rate has a wide selection range, and preferably, the thermal adhesion enhancer z i The melt flow rate at 190℃ and 2.16kg load is 0.5-50g / 10min, preferably 1-20g / 10min, more preferably 1-18g / 10min, and even more preferably 3-18g / 10min.

[0050] In a preferred embodiment of the present invention, the random copolymer polypropylene x i The random copolymer polypropylene β i The difference in melting points is less than 10°C, preferably less than 5°C, more preferably less than 3°C; and / or, the difference in melt flow rate at 230°C and 2.16 kg load is less than 10 g / 10 min, preferably less than 5 g / 10 min, more preferably less than 3 g / 10 min; and / or the difference in molecular weight distribution is less than 3, preferably less than 2, more preferably less than 1. Further preferably, the random copolymer polypropylene x i The random copolymer polypropylene β i same.

[0051] In a preferred embodiment of the present invention, the homopolymer polypropylene a i The homopolymer polypropylene γ i The difference in melting points is less than 10°C, preferably less than 5°C, more preferably less than 3°C; and / or, the difference in melt flow rate at 230°C and 2.16 kg load is less than 10 g / 10 min, preferably less than 5 g / 10 min, more preferably less than 3 g / 10 min; and / or, the difference in isotacticity (mm) is less than 3%, preferably less than 2%, more preferably less than 1%; further preferably, the homopolymer polypropylene a i The homopolymer polypropylene γ i same.

[0052] In a preferred embodiment of the present invention, the thermal adhesion enhancer y i The thermal bonding enhancer z i The difference between melting point and viscous flow temperature is less than 10°C, preferably less than 5°C, more preferably less than 3°C; and / or, the difference in melt flow rate at 190°C and 2.16 kg load is less than 10 g / 10 min, preferably less than 5 g / 10 min, more preferably less than 3 g / 10 min. Further preferably, the thermal bonding enhancer y... i The thermal bonding enhancer z i same.

[0053] According to the inventors' research, when polypropylene composition C iC' i and polypropylene composition B i B' i When the melt flow rate and polymer composition ratio are within the above-mentioned preferred range, the low-melting-point random copolymer polypropylene and the heat-bonding reinforcing agent in the composition can significantly reduce the hot-pressing temperature and widen the hot-pressing temperature window. Furthermore, the heat-bonding reinforcing agent provides good adhesion properties for the sheet and can further improve the interlayer peel strength.

[0054] In a preferred embodiment of the present invention, polypropylene composition A i The melting point is greater than that of the polypropylene composition C. i C' i and the polypropylene composition B i B' i The melting point, preferably corresponding to a temperature difference of 5 degrees Celsius or greater, more preferably 10 degrees Celsius or greater, and more preferably 20 degrees Celsius or greater. Preferably, polypropylene composition A... i Homopolymer polypropylene a in the middle component i The melting point is greater than that of the polypropylene composition C. i C' i Random copolymer polypropylene β i and polypropylene composition B i B' i random copolymers x i The melting point of the substance, and the corresponding temperature difference between the melting points is greater than or equal to 10 degrees.

[0055] According to the present invention, polypropylene composition C i C' i and polypropylene composition B i B' i Is there any particular limitation in this invention regarding the difference in melting points between them?

[0056] According to the inventor's research, when polypropylene composition A i Polypropylene combination C i C' i and composition B i B' i When the melt flow rate, melting point difference, polymer composition ratio, and polymer composition thickness distribution are within the above-mentioned preferred ranges, the sheet preparation process can be made more stable, thereby giving the sheet better uniformity, tensile strength, impact performance, and interlaminar peel strength.

[0057] According to the present invention, the B of the polypropylene sheet unit i C i A i C' i B' i The layered structure can be achieved by including a polypropylene composition Ai Polypropylene composition C i C' i and polypropylene composition B i B' i It is obtained by co-extrusion of the inner components.

[0058] According to the present invention, the polypropylene sheet can be a film or have a certain thickness. In the present invention, polypropylene film is one form of polypropylene sheet.

[0059] According to the present invention, the polypropylene sheet unit is a polypropylene sheet and / or a polypropylene fabric; the polypropylene sheet unit can be a polypropylene sheet or a polypropylene fabric. In a preferred embodiment of the present invention, the polypropylene sheet unit is a polypropylene sheet or a polypropylene fabric.

[0060] In a preferred embodiment of the present invention, the polypropylene sheet is made by comprising a polypropylene composition A i Polypropylene composition B i Polypropylene composition B' i Optional polypropylene composition C i Optional polypropylene composition C' i The components, including those mentioned above, are co-extruded to obtain the product.

[0061] In a preferred embodiment of the present invention, the polypropylene fabric is prepared by the following method: firstly, a polypropylene composition A is prepared... i Polypropylene composition B i Polypropylene composition B' i Optional polypropylene composition C i Optional polypropylene composition C' i The components are co-extruded to obtain a polypropylene sheet, and then the polypropylene sheet is woven to obtain the polypropylene fabric; preferably, the polypropylene fabric has a three-dimensional structure of plain weave, twill weave and / or satin weave.

[0062] According to the present invention, preferably, the polypropylene sheet units are connected by thermoforming.

[0063] In a preferred embodiment of the present invention, the polypropylene composite material has at least one of the following characteristics:

[0064] Longitudinal tensile strength ≥160MPa, preferably ≥180MPa; interlaminar peel strength ≥1.3N / mm, preferably ≥1.5N / mm.

[0065] The longitudinal tensile strength was determined according to the method specified in GB / T1040.1-2018, and the interlaminar peel strength was determined according to the method specified in GB / T2358-98. The corresponding specimens for the above two tests are the standard specimens required in the above test standards.

[0066] When the polypropylene composite material is obtained by hot pressing five polypropylene sheet units and the thickness of the polypropylene composite material is about 390 μm, the drop hammer impact strength is ≥42 J, preferably ≥45 J.

[0067] The drop hammer impact strength was determined according to the method specified in GB / T14153-1993, and the thickness of the sample was the same as the thickness of the prepared product.

[0068] The second objective of this invention is to provide a method for preparing the polypropylene composite material described above, comprising the step of sequentially stacking 2n-1 polypropylene sheet unit groups in the order of group n...group i...group 2, group 1, group 2...group i...group n, and then performing hot pressing fusion.

[0069] In embodiments where each polypropylene sheet unit group comprises only one polypropylene sheet unit, the preparation method includes processing 2n-1 polypropylene sheet units with a structure of B... i A i B' i The polypropylene sheet unit according to B n A n B' n ...B i A i B' i ...B2A2B'2, B1A1B'1, B2A2B'2...B i A i B' i ...B n A n B' n The layers are stacked sequentially, followed by a hot-pressing fusion process.

[0070] In embodiments where each polypropylene sheet unit group comprises two or more polypropylene sheet units, the preparation method includes sequentially stacking the polypropylene sheet units of each polypropylene sheet unit group, then sequentially stacking 2n-1 of the polypropylene sheet unit groups in the order of group n...group i...group 2, group 1, group 2...group i...group n, followed by a hot-pressing fusion step.

[0071] In a preferred embodiment of the present invention, the following steps are included:

[0072] (1) Polypropylene composition A iPolypropylene composition B i and polypropylene composition B' i Optional polypropylene composition C i Optional polypropylene composition C' i According to B i A i B' i Structure or B i C i A i C' i B' i The structure is co-extruded, cast or calendered, and stretched to obtain polypropylene sheets;

[0073] (2) Optionally, the polypropylene sheet is slit and then woven to obtain a structure of B. i A i B' i Or the structure is B i C i A i C' i B' i Polypropylene fabric;

[0074] (3) The polypropylene sheet and / or the polypropylene fabric are sequentially stacked and hot-pressed together, and then cooled and shaped to form a polypropylene composite material.

[0075] In a preferred embodiment of the present invention, in step (1), the polypropylene composition A i The preparation involves melt blending the raw materials, such as at least one of homopolymer polypropylene, random copolymer polypropylene, and impact copolymer polypropylene. The polypropylene composition A... i The conditions and equipment for melt blending are the same as those for melt blending of polyolefins in the prior art. Preferably, the melting temperature is 190-240℃ and the equipment is preferably a twin-screw extruder.

[0076] In a preferred embodiment of the present invention, in step (1), the polypropylene composition B i B' i The preparation includes melt blending the raw materials, such as at least one of homopolymer polypropylene, random copolymer polypropylene, and impact copolymer polypropylene; the polypropylene composition B i B' i The conditions and equipment for melt blending are the same as those for melt blending of polyolefins in the prior art. Preferably, the melting temperature is 190-240℃ and the equipment is preferably a twin-screw extruder.

[0077] In a preferred embodiment of the present invention, in step (1), the polypropylene composition Ci C' i The preparation includes melt blending the raw materials, such as at least one of homopolymer polypropylene, random copolymer polypropylene, and impact copolymer polypropylene; the polypropylene composition C i C' i The conditions and equipment for melt blending are the same as those for melt blending of polyolefins in the prior art. Preferably, the melting temperature is 190-240℃ and the equipment is preferably a twin-screw extruder.

[0078] In a preferred embodiment of the present invention, in step (1), the temperatures of co-extrusion molding and casting are independently selected from 200-240°C; and / or, the temperature of the calendering roll is 50-70°C.

[0079] In a preferred embodiment of the present invention, the stretching conditions include: a stretching temperature of 90-165°C, preferably 90-140°C, more preferably 90-119°C; and / or a stretching ratio of 1-15 times, preferably 2-9 times.

[0080] In a preferred embodiment of the present invention, the width of the polypropylene sheet obtained in step (1) is 2-5 mm.

[0081] In a preferred embodiment of the present invention, in step (3): the hot pressing conditions include: hot pressing temperature of 115-170℃, preferably 115-159℃, more preferably 140-159℃; hot pressing pressure of 2-10MPa; preheating time of 5-600s; and hot pressing time of 1-600s, preferably 10-500s.

[0082] In a preferred embodiment of the present invention, the cooling and shaping pressure is 2-8 MPa, and the cooling time is 30s-700s.

[0083] In a preferred embodiment of the present invention, adjacent polypropylene fabrics of the stack are placed at 0-90° between warp directions; and / or, adjacent polypropylene sheets of the stack are placed at 0-90° along their respective machine directions, which are the stretching directions (MD).

[0084] In a more preferred embodiment of the present invention, the method for preparing the polypropylene composite material includes the following steps:

[0085] Step a: Take polypropylene composition A i Polypropylene composition B i Polypropylene composition B' i Optional polypropylene composition C i Optional polypropylene composition C' i According to Bi A i B' i Structure or B i C i A i C' i B' i The structure is co-extruded and cast or calendered to obtain polypropylene co-extruded sheets; preferably, the extrusion casting or calendering temperature is 200-230℃, and the calendering roll temperature is 50-70℃;

[0086] Step b: The polypropylene co-extruded sheet is subjected to solid-state stretching at a certain temperature to obtain a polypropylene stretched film or stretched sheet; preferably, the stretching temperature is 90-165℃, more preferably 90-140℃, and even more preferably 90-119℃, and the stretching ratio is 1-15 times.

[0087] Step c: Cut the polypropylene stretched film or sheet into polypropylene flat strips, and weave the flat strips into polypropylene fabrics; preferably, the width of the polypropylene flat strips is 2-5 mm, and the polypropylene fabric structure includes, but is not limited to, plain weave, twill weave, satin weave and / or other three-dimensional polypropylene fabrics.

[0088] Step d: The polypropylene stretched film, sheet, or fabric is stacked sequentially from bottom to top as group n...group i...group 2, group 1, group 2...group i...group n, with a total of 2n-1 stacked groups, where n>=2. The polypropylene sheet or fabric is hot-pressed and fused together, then cooled and shaped to form a polypropylene composite material; preferably, the hot-pressing temperature is 110-180℃, more preferably 115-170℃, and even more preferably 130-160℃; the hot-pressing pressure is 2-10MPa, the preheating time is 5-600s, the hot-pressing time is 1-600s, preferably 10-500s, the cooling pressure is 2-8MPa, and the cooling time is 30s-700s; preferably, the polypropylene sheet in the polypropylene composite material can be placed at 0-90° to the machine direction, and the polypropylene fabric can be placed at 0-90° between the warp directions.

[0089] A third objective of this invention is to provide a continuous hot-pressing molding system for polypropylene composite materials, such as... Figure 1 As shown, the continuous hot pressing system for the composite material includes a preheater 1, a tracked continuous planar hot press 2, a tracked continuous planar cooling press 3, a sheet cutting machine 4, and a sheet stacking machine 5 arranged in sequence.

[0090] Preferably, the tracked continuous planar hot press 3 includes a preheating unit 6, an independent heating and pressurizing unit 7, an air-cooling unit 8, and a lifting mechanism 9.

[0091] According to a preferred embodiment of the present invention, the pressure is preferably maintained continuously during the hot pressing and cooling process without any decrease, and the hot pressing process is performed continuously, preferably as follows: Figure 1 As shown, a continuous hot-pressing composite material molding equipment is used, consisting of a preheating machine 1, a tracked continuous planar hot press 2, a tracked continuous planar cooling press 3, a sheet cutting machine 4, and a sheet stacking machine 5. Preferably, the tracked continuous planar hot press 2 has a preheating unit 6, an independent heating and pressurizing unit 7, an air-cooling unit 8, and a lifting mechanism 9. In the preparation process, the polypropylene stretched film, sheet, or / and fabric are sequentially layered and preheated by the preheating machine 1. The preheated sample is then sequentially passed through the tracked planar hot press 2 for hot pressing and fusion, and then cooled and shaped by the tracked continuous planar cooling press 3 to produce a polypropylene composite material, i.e., a laminated hot-pressed product. Afterwards, the product is sliced ​​by the sheet cutting machine 4 as needed, and then stacked and arranged by the sheet stacking machine 5. The hot-pressing temperature is controlled by the preheating unit 6, the independent heating and pressurizing unit 7, and the air-cooling unit 8 in the tracked planar hot press 2, and the hot-pressing pressure is controlled by the lifting mechanism 9.

[0092] According to the inventors' research, when the preparation process parameters are within the above-mentioned preferred range, and more preferably when the preparation equipment is used to prepare the polymer composite material, the polymer composite material has better tensile strength, impact performance and interlaminar peel strength.

[0093] The fourth objective of this invention is to provide an application of the polypropylene composite material described above and the polypropylene composite material prepared by the preparation method described above in the fields of consumer goods, automobile manufacturing, sports protection, and military materials.

[0094] According to specific embodiments of the present invention, the materials field includes the luggage and transportation industry, the footwear industry, the automobile manufacturing industry, the sports equipment manufacturing industry, the audio equipment manufacturing industry, and the military field.

[0095] The fifth objective of this invention is to provide a polypropylene sheet, preferably used as a polypropylene sheet unit in the polypropylene composite material described above, i.e., as a polypropylene sheet unit in a self-reinforced polypropylene composite material, comprising layer A and layers B and B' located on both sides of layer A, with a structure of BAB'; wherein layer A contains polypropylene composition A, and layer B and layer B' are the same or different, each corresponding to polypropylene composition B and polypropylene composition B', wherein the melting point of polypropylene composition A is greater than the melting point of polypropylene composition B and polypropylene composition B'; wherein polypropylene composition A comprises homopolymer polypropylene a and impact copolymer polypropylene b; each of polypropylene composition B and polypropylene composition B' comprises random copolymer polypropylene x and thermal bonding reinforcing agent y; preferably, the molecular weight distribution Mw / Mn of random copolymer polypropylene x is 5-12, preferably 7-10.

[0096] In a preferred embodiment of the present invention, the polypropylene sheet further comprises layers C and C', and the polypropylene sheet structure is BCAC'B'; layer C and layer C' may be the same or different, and each corresponds to polypropylene composition C and polypropylene composition C'; the melting point of polypropylene composition A is greater than the melting point of polypropylene composition C and polypropylene composition C'; wherein polypropylene composition C and polypropylene composition C' each comprise random copolymer polypropylene β and homopolymer polypropylene γ and thermal bonding reinforcing agent z; preferably, the molecular weight distribution Mw / Mn of random copolymer polypropylene β is 5-12, more preferably 7-10.

[0097] The characteristics described above for polypropylene sheet units all apply to polypropylene sheets. Regarding layer A in the polypropylene sheet unit... i B i B i '、C i and C i The described characteristics apply respectively to layers A, B, B', C, and C' in polypropylene sheets; regarding polypropylene composition A in polypropylene sheet units. i B i B i '、C i and C i The described characteristics apply respectively to polypropylene compositions A, B, B', C, and C' in polypropylene sheets; regarding homopolymer polypropylene a in polypropylene sheet units i Impact-resistant copolymer polypropylene b i Random copolymer polypropylene x i Thermal adhesive reinforcing agent y i Random copolymer polypropylene β i Homopolymer polypropylene γ i and thermal bonding enhancer z i The described features apply to homopolymer polypropylene a, impact copolymer polypropylene b, random copolymer polypropylene x, thermal bonding enhancer y, random copolymer polypropylene β, homopolymer polypropylene γ, and thermal bonding enhancer z in polypropylene sheets, respectively.

[0098] In a preferred embodiment of the present invention, the melting point of the polypropylene composition A is greater than that of the polypropylene compositions B and B'; preferably, the melting point of the homopolymer polypropylene a in the polypropylene composition A is greater than that of the random copolymer polypropylene x in the polypropylene compositions B and B', and preferably the temperature difference between the corresponding melting points is greater than or equal to 10 degrees. In this preferred embodiment, the inventors of the present invention have surprisingly discovered that the polypropylene sheet obtained is hot-pressed to obtain a polypropylene composite material, which has superior mechanical properties and better interlaminar peel strength. Even at lower hot-pressing temperatures and over a wider range of hot-pressing temperatures, the polypropylene composite material obtained has higher interlaminar peel strength.

[0099] According to the inventors' research, when the melt flow rate, polymer composition ratio, and thickness distribution of film layer A of polypropylene composition A and polypropylene compositions B and B' are within the preferred range, the sheet preparation process can be made more stable, thereby giving the sheet better uniformity, tensile strength, impact performance, and interlayer peel strength.

[0100] The BAB' layer structure of the polypropylene sheet can be prepared by various methods. In a preferred embodiment of the present invention, the BAB' layer structure of the polypropylene sheet is obtained by co-extrusion of components including polypropylene composition A and polypropylene compositions B and B'.

[0101] In a preferred embodiment of the present invention, the melting point of polypropylene composition A is greater than that of polypropylene compositions B, B', and C, C', preferably with a melting point temperature difference greater than or equal to 5 degrees Celsius, more preferably greater than or equal to 10 degrees Celsius, and even more preferably greater than or equal to 20 degrees Celsius. Preferably, the melting point of homopolymer polypropylene a in polypropylene composition A is greater than that of random copolymer polypropylene β in polypropylene compositions B and B' and random copolymer x in polypropylene compositions C and C', and the corresponding melting point temperature difference is greater than or equal to 10 degrees Celsius.

[0102] According to the present invention, there is no particular limitation on the melting point difference between polypropylene compositions B, B' and polypropylene compositions C, C'.

[0103] According to the inventors' research, when the melt flow rate, melting point difference, polymer composition ratio, and polymer composition thickness distribution of polypropylene compositions A, B, B', and C, C' are within the above-mentioned preferred ranges, the sheet preparation process can be made more stable, thereby giving the sheet better uniformity, tensile strength, impact performance, and interlaminar peel strength.

[0104] According to the present invention, the BCAC'B' sheet structure of the polypropylene composite sheet can be obtained by co-extruding components including polypropylene composition A, polypropylene composition B, B' and polypropylene composition C, C'.

[0105] The sixth objective of this invention is to provide a method for preparing the polypropylene sheet described above, comprising co-extruding, casting or calendering, and stretching polypropylene composition A, polypropylene composition B, polypropylene composition B', optional polypropylene composition C, and optional polypropylene composition C' according to a BAB' structure or a BCAC'B' structure to obtain the polypropylene sheet.

[0106] In a preferred embodiment of the present invention, the preparation of the polypropylene composition A includes melt blending of components including the homopolymer polypropylene a and the impact copolymer polypropylene b; and / or, the preparation of the polypropylene compositions B and B' includes melt blending of components including the random copolymer polypropylene x and the heat-bonding reinforcing agent y; and / or, the preparation of the polypropylene compositions C and C' includes melt blending of components including the heat-bonding reinforcing agent z, the random copolymer polypropylene β, and the homopolymer polypropylene γ; and / or, the temperatures of the co-extrusion and casting are each independently selected from 200-240°C; and / or, the temperature of the calendering roll is 50-70°C; and / or, the stretching conditions include: a stretching temperature of 90-165°C, preferably 90-140°C, more preferably 90-119°C; and a stretching ratio of 1-15 times; preferably 2-9 times.

[0107] According to some embodiments of the present invention, polypropylene composition A, polypropylene composition B, polypropylene composition B', optional polypropylene composition C, and optional polypropylene composition C' are co-extruded according to a BAB' structure or a BCAC'B' structure, and then cast or calendered to obtain a polypropylene co-extruded sheet. The extrusion calendering process may include passing the polypropylene co-extruded sheet sequentially through calendering rollers and traction rollers, followed by solid-state stretching, edge trimming, and winding to obtain the sheet. The extrusion casting temperature is 200-230°C, and the calendering roller temperature is 50-70°C. The specific process for preparing the film using the extrusion calendering method is a commonly used choice in the art and will not be described in detail here.

[0108] The characteristics described above regarding the preparation method of polypropylene sheet units are all applicable to the preparation method of polypropylene sheets.

[0109] The seventh objective of this invention is to provide a polypropylene fabric, a three-dimensional polypropylene fabric obtained by weaving the polypropylene sheets described above; preferably, the polypropylene fabric has a three-dimensional structure of plain weave, twill weave and / or satin weave.

[0110] To facilitate weaving, it is preferable to cut the polypropylene sheet into polypropylene sheet cuts with a width of 2-5mm, and then weave them into polypropylene fabric.

[0111] In a more preferred embodiment of the present invention, the polypropylene fabric is a plain weave, twill weave, satin weave, or three-dimensional polypropylene fabric obtained by weaving a three-layer co-extruded polypropylene stretch flat strip, and the three-layer co-extruded polypropylene stretch flat strip includes layer A formed by a high-melting-point polypropylene composition A and layers B and B' formed by low-melting-point polypropylene compositions B and B', wherein polypropylene composition A includes homopolymer polypropylene a and impact copolymer polypropylene b; polypropylene compositions B and B' include random copolymer polypropylene x and thermal bonding reinforcing agent y, and the structure of the three-layer polypropylene fabric from bottom to top is BAB'.

[0112] In a more preferred embodiment of the present invention, the polypropylene fabric is a plain weave, twill weave, satin weave, and / or three-dimensional polypropylene fabric obtained by weaving five-layer co-extruded polypropylene stretch flat strip, and the co-extruded polypropylene stretch flat strip includes layer A formed by high-melting-point polypropylene composition A, intermediate layers C and C' formed by polypropylene composition C, and layers B and B' formed by low-melting-point polypropylene composition B, wherein polypropylene composition A includes homopolymer polypropylene a and impact copolymer polypropylene b; polypropylene compositions C and C' include thermal bonding reinforcing agent z, random copolymer polypropylene β, and homopolymer polypropylene γ; polypropylene compositions B and B' include random copolymer polypropylene x and thermal bonding reinforcing agent y, and the structure of the five-layer polypropylene fabric from bottom to top is BCAC'B'.

[0113] The characteristics described above regarding polypropylene sheet units and polypropylene sheets also apply to polypropylene fabrics.

[0114] The eighth objective of this invention is to provide a polypropylene composite material, which is prepared by hot pressing multiple layers of polypropylene sheets and / or polypropylene fabrics as described above. Preferably, the polypropylene fabric is stacked from top to bottom with warp directions arranged at 0-90° intervals, preferably with more than or equal to 2 layers, more preferably with 2-200 layers, and most preferably with 4-100 layers. The multiple polypropylene sheets are stacked from top to bottom with their respective machine directions arranged at 0-90° intervals, preferably with more than or equal to 2 layers, more preferably with 2-200 layers, and most preferably with 4-100 layers.

[0115] In a preferred embodiment of the present invention, the polypropylene fabrics in each of the stacked layers may contain the same or different polypropylene composition A, and each layer of polypropylene fabric A may be independently selected, preferably the polypropylene composition A in each layer is the same.

[0116] In a preferred embodiment of the present invention, the polypropylene composite material has at least one of the following characteristics:

[0117] Longitudinal tensile strength ≥150MPa, preferably ≥170MPa;

[0118] Interlayer peel strength ≥1N / mm, preferably ≥1.2N / mm;

[0119] Tensile strength was determined according to the method specified in GB / T1040.1-2018, and interlaminar peel strength was determined according to the method specified in GB / T2358-98. The corresponding specimens for the above two tests were the standard specimens required in the above testing standards.

[0120] When the polypropylene composite material is obtained by hot pressing 24 layers of polypropylene fabric and the thickness is about 1.6 mm, the drop hammer impact strength is ≥228 J, preferably ≥240 J.

[0121] The drop hammer impact strength was determined according to the method specified in GB / T14153-1993, and the thickness of the sample was the same as the thickness of the prepared product.

[0122] According to the present invention, when the polypropylene composite sheet is a BCAC'B' layered structure, the polypropylene composite material has at least one of the following characteristics:

[0123] Longitudinal (MD) tensile strength ≥150MPa, preferably ≥170MPa; interlaminar peel strength ≥1.1N / mm, preferably ≥1.3N / mm. When the composite material is made of 24 layers of polypropylene fabric hot-pressed together with a thickness of about 1.8mm, the drop hammer impact strength ≥240J, preferably ≥250J.

[0124] The ninth objective of this invention is to provide a method for preparing the polypropylene composite material described above, the method comprising hot-pressing and fusing the polypropylene sheet and / or the polypropylene fabric into a laminate, and then cooling and shaping it to form the polypropylene composite material.

[0125] In a preferred embodiment of the present invention, the temperature of the hot-pressing fusion is 115-170°C, preferably 115-159°C, and more preferably 140-159°C.

[0126] In a preferred embodiment of the present invention, the pressure of the hot-press fusion is 2-10 MPa.

[0127] In a preferred embodiment of the present invention, the preheating time for hot pressing fusion is 5-600s, and the hot pressing time is 1-600s, preferably 10-500s.

[0128] In a preferred embodiment of the present invention, the cooling and shaping pressure is 2-8 MPa, and the cooling and shaping time is 30s-700s.

[0129] In a preferred embodiment of the present invention, the number of layers of the polypropylene sheet and / or polypropylene fabric stack is greater than or equal to 2 layers, preferably 2-200 layers; more preferably 4-100 layers.

[0130] In a preferred embodiment of the present invention, adjacent layers of the polypropylene sheet stack are placed at 0-90° along their respective machine directions, i.e., the stretching direction (MD).

[0131] In a preferred embodiment of the present invention, adjacent layers of the polypropylene fabric stack are placed at an angle of 0-90° between the warp and weft directions.

[0132] In a more preferred embodiment of the present invention, the method for preparing the high-strength, high-impact polypropylene composite material includes the following steps:

[0133] Step a: Polypropylene composition A, polypropylene composition B, and B' are co-extruded according to the BAB' structure and then cast or calendered to obtain a polypropylene co-extruded sheet; preferably, the extrusion casting or calendering temperature is 200-240°C, and the temperature of the calendering roll is 50-70°C.

[0134] Step b: The polypropylene co-extruded sheet is stretched at a certain temperature to obtain a polypropylene stretched sheet; preferably, the stretching temperature is 90-165℃, more preferably 90-140℃, and even more preferably 90-119℃, with a stretching ratio of 1-15 times, preferably 2-9 times.

[0135] Step c: Cut the polypropylene stretched sheet into polypropylene flat strips, and weave the flat strips into polypropylene fabrics; preferably, the width of the polypropylene flat strips is 2-5 mm, and the polypropylene fabrics include plain weave, twill weave, satin weave or other three-dimensional polypropylene fabrics.

[0136] Step d: The polypropylene fabrics are sequentially stacked and hot-pressed together, and then cooled and shaped to form a polypropylene composite material; preferably, in step d, the hot-pressing conditions are: hot-pressing temperature 115-170℃, preferably 115-159℃, more preferably 140-159℃; hot-pressing pressure 2-10MPa, preheating time 5-600s, hot-pressing time 1-600s, preferably 10-500s, cooling pressure 2-8MPa, cooling time 30s-700s; preferably, adjacent polypropylene fabrics in the polypropylene composite material can be placed at 0-90° between the warp and weft directions.

[0137] According to some embodiments of the present invention, in step c, a high-speed slitting machine with multiple blades can be used to cut the oriented polypropylene flat strip with a width of 2-5 mm; the oriented flat strip is then woven into plain weave, twill weave, satin weave and / or other three-dimensional polypropylene fabrics using a commercial weaving machine according to the designed fabric structure.

[0138] In a more preferred embodiment of the present invention, the method for preparing the polypropylene composite material includes the following steps:

[0139] Step a: Polypropylene composition A, polypropylene compositions C, C', polypropylene compositions B, B' are co-extruded according to the BCAC'B' structure and then cast or calendered to obtain polypropylene co-extruded sheets; preferably, the extrusion casting or calendering temperature is 200-230℃, and the calendering roll temperature is 50-70℃;

[0140] Step b: The polypropylene co-extruded sheet is stretched at a certain temperature to obtain a polypropylene stretched sheet. The stretching temperature is preferably 90-165℃, more preferably 90-140℃, and even more preferably 90-119℃ with a stretching ratio of 1-15 times.

[0141] Step c: Cut the polypropylene stretched sheet into polypropylene flat strips, and weave the flat strips into polypropylene fabric; preferably, the width of the polypropylene flat strip is 2-5 mm, and the polypropylene fabric includes plain weave, twill weave, satin weave, or other three-dimensional polypropylene fabrics.

[0142] Step d: The polypropylene sheets or fabrics are sequentially stacked and hot-pressed together, and then cooled and shaped to form a polypropylene composite material; the preferred hot-pressing conditions are: hot-pressing temperature 115-170℃, preferably 115-159℃, more preferably 140-159℃; hot-pressing pressure 2-10MPa, preheating time 5-300s, hot-pressing time 1-300s, preferably 1-9s or 61-100s, cooling pressure 2-8MPa, cooling time 30s-700s; the polypropylene fabrics in the polypropylene composite material can be placed at 0-90° between warp directions and / or the polypropylene composite sheets can be placed at 0-90° along their respective machine directions.

[0143] According to a preferred embodiment of the present invention, the pressure is preferably maintained continuously during the hot pressing and cooling process without any decrease. The hot pressing process is continuous, and preferably a continuous hot pressing composite material molding equipment is adopted, consisting of a preheating machine, a crawler-type continuous planar hot press, a crawler-type continuous planar cooling press, a sheet cutting machine, and a sheet stacking machine arranged in sequence. Preferably, the crawler-type continuous planar hot press has a preheating unit, an independent heating and pressurizing unit, an air cooling unit, and a lifting mechanism.

[0144] In the preparation process, the polypropylene sheets and / or polypropylene fabrics are sequentially stacked and preheated in a preheating machine. The preheated samples are then sequentially hot-pressed and fused using a tracked flatbed hot press, followed by cooling and shaping using a tracked continuous flatbed cooling press to produce a polypropylene composite material, i.e., a stacked hot-pressed product. Afterwards, the product is sliced ​​as needed using a sheet cutter, and then stacked and arranged using a sheet stacking machine. The hot-pressing temperature is controlled by the preheating unit, independent heating and pressurizing unit, and air-cooling unit in the tracked flatbed hot press, while the hot-pressing pressure is controlled by a lifting mechanism. According to the inventors' research, when the preparation process parameters are within the preferred range, and when the aforementioned preparation equipment is used to prepare the polymer composite material, the polymer composite material exhibits better tensile strength, impact performance, and interlaminar peel strength.

[0145] The tenth objective of this invention is to provide an application of the polypropylene sheet, polypropylene fabric, polypropylene composite material, and polypropylene composite material prepared by the preparation method described above in the fields of sports protection, automobile manufacturing, military materials, and consumer products.

[0146] According to specific embodiments of the present invention, the materials field includes the luggage and transportation industry, the footwear industry, the automobile manufacturing industry, the sports equipment manufacturing industry, the audio equipment manufacturing industry, and the military field.

[0147] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0148] (1) The polypropylene composite material of the present invention has a melting point gradient structure. Under this specific structure, the inventors of the present invention surprisingly discovered that the resulting polypropylene composite material has good tensile strength, impact performance and interlaminar peel strength.

[0149] Specifically, when the polypropylene composite sheet is a BAB' layered structure, the polypropylene composite material has the following characteristics: longitudinal (MD) tensile strength ≥150 MPa, preferably ≥170 MPa; interlayer peel strength ≥1 N / mm, preferably ≥1.2 N / mm; when the composite material is made of only 24 layers of polypropylene fabric hot-pressed together and the thickness is about 1.6 mm, the drop hammer impact strength ≥228 J, preferably ≥240 J.

[0150] Specifically, when the polypropylene composite sheet is a BCAC'B' layered structure, the polypropylene composite material has the following characteristics: longitudinal (MD) tensile strength ≥150 MPa, preferably ≥170 MPa; interlaminar peel strength ≥1.1 N / mm, preferably ≥1.3 N / mm; when the composite material is made of 24 layers of polypropylene fabric hot-pressed together with a thickness of about 1.8 mm, the drop hammer impact strength ≥240 J, preferably ≥250 J.

[0151] (2) The polypropylene composite material of the present invention is suitable for preparation at a lower hot pressing temperature and a wider hot pressing temperature range. The hot pressing temperature range can effectively reduce the energy consumption of equipment and the damage to the composite material caused by high temperature operation. At the same time, when prepared at a lower hot pressing temperature, it still has good interlayer peel strength.

[0152] (3) This preparation method can reduce the hot pressing operation time, while improving production efficiency and reducing production energy consumption.

[0153] (4) The present invention adopts a melting point gradient structure design, which reduces the hot pressing temperature and widens the hot pressing temperature range to 70°C; effectively reducing equipment energy consumption and damage to composite materials under high temperature operation.

[0154] The present invention also relates to the following embodiments:

[0155] 1. A polypropylene composite material comprising a plurality of sequentially stacked polypropylene sheet units; each polypropylene sheet unit including a core layer A i and located in core layer A i Outer B on both sides i B' i The structure is B i A i B' i The structure of the polypropylene composite material, from bottom to top, is B. n A n B' n ...B i A i B' i ...B2A2B'2, B1A1B'1, B2A2B'2...B i A i B' i ...B n A n B' n The total number of layers in the polypropylene sheet unit is 2n-1; i and n are both integers not less than 2, and i≤n;

[0156] Among them, the core layer A in the polypropylene sheet unit i Composition A containing polypropylene i Outer layer B i With outer layer B' i Whether the composition is the same or different, each composition corresponds to a polypropylene composition B. i Polypropylene composition B' i ,

[0157] The polypropylene composition A i The melting point is greater than that of the polypropylene composition B. i The polypropylene composition B'i The melting point of the polypropylene composition B; i Polypropylene composition B' i The melting point of each is greater than that of the adjacent polypropylene composition B'. i-1 Polypropylene composition B i-1 Its melting point.

[0158] 2. The polypropylene composite material according to embodiment 1, characterized in that:

[0159] Polypropylene Composition A i The melting point of polypropylene composition B i The difference in melting points, polypropylene composition A i The melting point of polypropylene composition B' i The difference in melting points is greater than or equal to 10°C, preferably greater than or equal to 20°C; and / or,

[0160] Polypropylene composition B i Polypropylene composition B' i The melting point of each of the adjacent polypropylene compositions B' i-1 Polypropylene composition B i-1 The difference in melting points may be the same or different, each ranging from 1 to 40°C, preferably from 1 to 10°C, and more preferably from 1 to 5°C.

[0161] 3. The polypropylene composite material according to embodiment 1, characterized in that: 2≤n≤100, preferably, 2≤n≤50.

[0162] 4. The polypropylene composite material according to embodiment 1, characterized in that:

[0163] Based on the total thickness of each polypropylene sheet unit, the core layer A in each polypropylene sheet unit i The thickness accounts for 51%-89% of the total thickness, preferably 71%-89%, and more preferably 71%-80%.

[0164] 5. The polypropylene composite material according to embodiment 1, characterized in that:

[0165] The polypropylene composition A i Including one or more of homopolymer polypropylene, random copolymer polypropylene, and impact copolymer polypropylene; and / or,

[0166] The polypropylene composition B i B' i Each comprises one or more of homopolymer polypropylene, random copolymer polypropylene, and impact copolymer polypropylene; preferably, the polypropylene composition B i and / or polypropylene composition B' iIt also contains thermal bonding enhancer y i .

[0167] 6. The polypropylene composite material according to embodiment 5, characterized in that:

[0168] Polypropylene Composition A i Including homopolymer polypropylene a i Impact-resistant copolymer polypropylene b i ;

[0169] Preferably, the polypropylene composition A is used. i Based on the total weight, the polypropylene composition A i Includes 50-99 wt% homopolymer polypropylene a i 1-50wt% impact-resistant copolymer polypropylene b i Further preferably, the polypropylene composition A i Includes 70-90 wt% homopolymer polypropylene a i 10-30wt% impact-resistant copolymer polypropylene b i ; and / or,

[0170] The polypropylene composition B i The polypropylene composition B' i Each includes random copolymer polypropylene x i and thermal bonding enhancer y i ;

[0171] Preferably, the polypropylene composition B is used. i The polypropylene composition B' i Based on their respective total weights, the polypropylene composition B i The polypropylene composition B' i Each comprises 70-99 wt% random copolymer polypropylene. i 1-30wt% thermal bonding enhancer i Preferably, the polypropylene composition B i Includes 80-90 wt% random copolymer polypropylene x i 10-20wt% of thermal bonding reinforcing agent i .

[0172] 7. The polypropylene composite material according to embodiment 6, characterized in that:

[0173] The homopolymer polypropylene a i The melting point is 150-170℃; and / or,

[0174] The homopolymer polypropylene a i The isotacticity (mm) is not less than 96%; and / or,

[0175] The impact-resistant copolymer polypropylene b i The melting point is 150-170℃: and / or,

[0176] The monomer for the copolymerization of the impact-resistant polypropylene and propylene is ethylene or butene, preferably butene; and / or,

[0177] The cantilever beam impact strength of the impact-resistant copolymer polypropylene is not less than 20 KJ / m. 2 .

[0178] 8. The polypropylene composite material according to embodiment 6, characterized in that:

[0179] The random copolymer polypropylene x i Its melting point is 110-150℃, and x i Its melting point is greater than x i-1 The melting point, preferably a difference of 1-40°C, more preferably 1-10°C, and most preferably 1-5°C; and / or,

[0180] The random copolymer polypropylene x i It is a copolymer of propylene with ethylene and / or butene, preferably an ethylene-propylene-butene terpolymer and / or a propylene-ethylene binary copolymer.

[0181] 9. The polypropylene composite material according to embodiment 6, characterized in that:

[0182] The thermal adhesive reinforcing agent y i The melting point or viscous flow temperature is 70-110℃; and / or,

[0183] The thermal adhesive reinforcing agent y i It is selected from one or more of polyolefin elastomers, ethylene propylene diene monomer (EPDM) rubber, SEBS, SBS, EVA, and petroleum resins;

[0184] Preferably, the thermal bonding enhancer y i It is a polyolefin elastomer and / or petroleum resin.

[0185] 10. The polypropylene composite material according to embodiment 9, characterized in that:

[0186] The polyolefin elastomer is a copolymer elastomer of ethylene and propylene and / or α-olefins, wherein the α-olefin is preferably a C4-C12 α-olefin, more preferably 1-butene and / or 1-octene; and / or,

[0187] The petroleum resin is a C5 and / or C9 hydrogenated petroleum resin with a softening point of 100-150℃; preferably a cyclopentadiene type resin.

[0188] 11. The polypropylene composite material according to embodiment 5, characterized in that:

[0189] The polypropylene composition A i It also includes a β-crystal nucleating agent; preferably,

[0190] The β-crystal nucleating agent is selected from at least one of polycyclic aromatic hydrocarbons, group IIA binary complexes, aromatic diamides, rare earth compounds, and cyclic dicarboxylate nucleating agents; and / or,

[0191] With the polypropylene composition A i The total amount is 100 parts by weight, of the polypropylene composition A i The content of the β-crystal nucleating agent mentioned herein is 0.01-0.5 parts by weight.

[0192] 12. The polypropylene composite material according to any one of embodiments 1-11, characterized in that:

[0193] The polypropylene sheet unit is a polypropylene sheet and / or a polypropylene fabric; preferably, the polypropylene sheet unit is a polypropylene sheet or a polypropylene fabric; more preferably,

[0194] The polypropylene sheet is made by comprising a polypropylene composition A i Polypropylene composition B i and polypropylene composition B' i The components are co-extruded together; and / or,

[0195] The polypropylene fabric is prepared by the following method: firstly, a polypropylene composition A is prepared... i Polypropylene composition B i Polypropylene composition B' i Polypropylene sheets are obtained by co-extrusion of the inner components, and then the polypropylene sheets are woven to obtain the polypropylene fabric; preferably, the polypropylene fabric has a three-dimensional structure of plain weave, twill weave and / or satin weave.

[0196] 13. The polypropylene composite material according to embodiment 12, characterized in that:

[0197] The polypropylene sheet units are connected by hot-pressing.

[0198] 14. A method for preparing a polypropylene composite material according to any one of embodiments 1-13, comprising: preparing 2n-1 polypropylene composite materials with a structure of B... i A i B' i The polypropylene sheet unit according to B n A n B' n ...Bi A i B' i ...B2A2B'2, B1A1B'1, B2A2B'2...B i A i B' i ...B n A n B' n The layers are stacked sequentially, followed by a hot-pressing fusion process.

[0199] 15. The preparation method according to embodiment 14, characterized by comprising the following steps:

[0200] (1) Polypropylene composition A i Polypropylene composition B i and polypropylene composition B' i According to B i A i B' i The structure is co-extruded, cast or calendered, and stretched to obtain polypropylene sheets;

[0201] (2) Optionally, the polypropylene sheet is slit and then woven to obtain a structure of B. i A i B' i Polypropylene fabric;

[0202] (3) The polypropylene sheet and / or the polypropylene fabric are sequentially stacked and hot-pressed together, and then cooled and shaped to form a polypropylene composite material.

[0203] 16. The preparation method according to embodiment 15, characterized in that:

[0204] In step (1), polypropylene composition A i The preparation includes melt blending of components including at least one of homopolymer polypropylene, random copolymer polypropylene, and impact copolymer polypropylene; and / or,

[0205] The polypropylene composition B in step (1) i The preparation includes melt blending of components including at least one of homopolymer polypropylene, random copolymer polypropylene, and impact copolymer polypropylene; and / or,

[0206] In step (1), the temperatures for extrusion molding and casting are independently selected from 200-240℃; and / or,

[0207] In step (1), the temperature of the calendering roll is 50-70℃; and / or,

[0208] The stretching temperature in step (1) is 90-165℃, preferably 90-140℃, and more preferably 90-119℃; and / or,

[0209] In step (1), the stretching ratio is 1-15 times.

[0210] 17. The preparation method according to embodiment 15, characterized in that:

[0211] In step (3):

[0212] The hot pressing conditions include: a hot pressing temperature of 115-170℃, preferably 115-159℃, more preferably 140-159℃; a hot pressing pressure of 2-10 MPa; a preheating time of 5-600 s; a hot pressing time of 1-600 s, preferably 10-500 s; and / or,

[0213] The cooling and shaping pressure is 2-8 MPa, and the cooling time is 30-700 seconds; and / or,

[0214] The adjacent polypropylene fabrics of the stack are placed at an angle of 0-90° between the warp directions; and / or,

[0215] The adjacent polypropylene sheets in the stack are placed at 0-90° along their respective machine directions.

[0216] 18. A continuous hot pressing system for polypropylene composite materials according to any one of embodiments 1-13, comprising a preheater, a tracked continuous planar hot press, a tracked continuous planar cooling press, a sheet cutter, and a sheet stacker arranged in sequence.

[0217] Preferably, the tracked continuous planar hot press includes a preheating unit, an independent heating and pressurizing unit, an air-cooling unit, and a lifting mechanism.

[0218] 19. Applications of the polypropylene composite material according to any one of embodiments 1-13 and the polypropylene composite material prepared by the preparation method according to any one of embodiments 14-17 in the fields of consumer products, automobile manufacturing, sports protection and military materials. Attached Figure Description

[0219] Figure 1 This is a schematic diagram of the arrangement of processing equipment used in a preferred embodiment of the present invention.

[0220] 1 is a preheating machine; 2 is a crawler-type continuous flat hot press; 3 is a crawler-type continuous flat cooling press; 4 is a sheet cutting machine; 5 is a sheet stacking machine; the crawler-type continuous flat hot press 2 has a preheating unit 6; an independent heating and pressurizing unit 7; an air cooling unit 8; and a lifting mechanism 9. Detailed Implementation

[0221] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be noted that the following embodiments are only used to further illustrate the present invention and should not 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 content of the present invention are still within the scope of protection of the present invention.

[0222] The properties of the polypropylene composition and sheet were tested according to the following methods, and the product test results are shown in Table 1:

[0223] (1) Melt mass flow rate (MFR): The test shall be performed in accordance with the method specified in GB / T 3682-2000. For polypropylene (including homopolymer polypropylene, impact copolymer polypropylene and random copolymer polypropylene), the test temperature is 230℃ and the load is 2.16kg. For heat-bonding reinforcing agents, the test temperature is 190℃ and the load is 2.16kg.

[0224] (2) Molecular weight distribution (Mw / Mn): The molecular weight distribution was determined according to the method specified in GB / T 36214.1-2018, where Mw is the weight-average molecular weight in g / mol and Mn is the number-average molecular weight in g / mol.

[0225] (3) The melting point of the material was determined by the method of GB / T 28724-2012. The sample mass was 5 mg. The temperature was increased from 50 °C to 230 °C at a rate of 10 °C / min. The temperature was held at 230 °C for 3 min to eliminate the thermal history. The temperature was then decreased from 230 °C to 50 °C at a rate of 10 °C / min. The temperature was held at 50 °C for 1 min. Finally, the temperature was increased from 50 °C to 230 °C at a rate of 10 °C / min. The last temperature curve was used to determine the melting point or melting range of the material.

[0226] (4) Sheet tensile strength: The tensile strength shall be determined in accordance with the method specified in GB / T1040.1-2018.

[0227] (5) Drop hammer impact strength: The test shall be conducted in accordance with the method specified in GB / T14153-1993.

[0228] (6) Interlayer peel strength: The test shall be performed in accordance with the method specified in QB / T2358-98.

[0229] In the following examples, the β-crystal nucleating agent with the brand name VP101B was sourced from the Beijing Research Institute of Chemical Industry, China Petroleum & Chemical Corporation; the sources of some raw materials are described in the examples, and the remaining raw materials are commercially available unless otherwise specified.

[0230] Example A1

[0231] This embodiment illustrates the preparation of the polypropylene composition, three-layer co-extruded polypropylene sheet, polypropylene fabric, and polypropylene composite material provided by the present invention.

[0232] (1) Preparation of polypropylene composition A:

[0233] Component a is a homopolymer polypropylene self-produced by the Beijing Research Institute of Chemical Industry of Sinopec, with a melting point of 160℃, a melt flow rate (melt mass flow rate) of 3.2 g / 10 min, and an isotacticity of 97%; component b is a polypropylene impact copolymer self-produced by the Beijing Research Institute of Chemical Industry of Sinopec, with an ethylene content of 11 wt%, a melting point of 155℃, and a cantilever beam impact strength of 23 KJ / m. 2 (23℃), melt flow rate is 2.0 g / 10 min. The above-prepared components are weighed and mixed according to the proportions, wherein the mass fraction Wa of component a is 80 parts by weight and the mass fraction Wb of component b is 20 parts by weight.

[0234] Add 0.05 parts by weight of β-crystal nucleating agent of grade VP101B. Then, add the mixture to a high-speed mixer and mix evenly. Then, add the mixed material to the feeder of a twin-screw extruder manufactured by W&P. The material enters the twin screw through the feeder. During the processing, the screw temperature is maintained between 200-230°C. After being melted and mixed evenly by the screw, extruded, granulated and dried, polypropylene composition granules A are obtained. The melting point of polypropylene composition granules A is tested to be 157°C.

[0235] (2) Polypropylene composition B i Preparation:

[0236] Component x1 is a random copolymer polypropylene produced by the Beijing Research Institute of Chemical Industry of Sinopec, which is an ethylene-propylene-butene terpolymer with a molecular weight distribution Mw / Mn of 8.9, a melt flow rate of 8.1 g / 10 min, and a melting point of 130℃; Component x2 is a random copolymer polypropylene produced by the Beijing Research Institute of Chemical Industry of Sinopec, which is an ethylene-propylene-butene terpolymer with a molecular weight distribution Mw / Mn of 7.6, a melt flow rate of 7.2 g / 10 min, and a melting point of 135℃; Component x3 is a random copolymer polypropylene produced by the Beijing Research Institute of Chemical Industry of Sinopec, which is an ethylene-propylene-butene terpolymer with a molecular weight distribution Mw / Mn of 7.3, a melt flow rate of 6.6 g / 10 min, and a melting point of 140℃; Component y is a polyolefin elastomer of grade 6102, purchased from ExxonMobil, which is an ethylene-propylene copolymer.

[0237] The components obtained above are weighed and mixed according to the specified proportions, wherein component x i mass parts Wx iThe weight percentage of component y is 85 parts by weight, and the weight percentage of component y (Wy) is 15 parts by weight. Other steps are the same as in step (1), and the final polypropylene composition B is obtained. i Granular material (i.e., x) i +y=B i (i = 1, 2, 3), after testing, the melting point of B1 is 127℃, the melting point of B2 is 132℃, and the melting point of B3 is 138℃.

[0238] (3) Preparation of three-layer co-extruded polypropylene sheets:

[0239] The polypropylene composition A and polypropylene composition B obtained in steps (1) and (2) above are used. i The granules are dried, and then polypropylene composition A is added to the core layer extruder of a multilayer extrusion calender, and polypropylene composition B is added. i The granules are fed into the upper and lower surface extruders of a multi-layer extrusion casting machine. After being co-extruded and compounded through the extruder die, the granules pass sequentially through calendering rolls and traction rolls, followed by solid-phase stretching, edge trimming, and winding to produce sheets B1AB1, B2AB2, and B3AB3, respectively. The extrusion casting temperature is 230℃, and the calendering roll temperature is 58℃. The solid-phase stretching process is carried out at 140℃, with a stretching rate of 2 m / min and a stretch ratio of 7.

[0240] A composite film (polypropylene sheet) made by stretching and then winding consists of an upper surface layer (outer film B). i ), core layer (film A) and lower surface layer (outer film B) i The composite film is composed of layers A and B. The composite film is 80 μm thick, with layer A accounting for 80% of the total thickness of the sheet.

[0241] (4) Preparation of polypropylene fabric:

[0242] The three-layer co-extruded polypropylene sheet obtained in step (3) above is cut with a high-speed slitting machine with multiple blades to obtain oriented polypropylene flat strips with a width of 3mm; the oriented flat strips are woven with commercial weaving machines according to the designed fabric structure to obtain plain weave polypropylene fabrics B1AB1, B2AB2, and B3AB3.

[0243] (5) Preparation of polypropylene composite materials:

[0244] The polypropylene fabrics obtained in step (4) were stacked sequentially from bottom to top as follows: B3A3B3, B2A2B2, B1A1B1, B2A2B2, and B3A3B3, for a total of 5 layers. The stacked polypropylene fabrics were then hot-pressed together and cooled to form a polypropylene composite material. The polypropylene fabrics were placed at a 90° angle between the warp and weft directions. The hot-pressing conditions were: temperature 145℃, hot-pressing pressure 5MPa, preheating time 90s, hot-pressing time 90s, and cooling time 300s. The thickness of the prepared polypropylene composite material was 391μm.

[0245] Example A2

[0246] This embodiment illustrates the preparation of the polypropylene composition, three-layer co-extruded polypropylene sheet, polypropylene fabric, and polypropylene composite material provided by the present invention.

[0247] (1) Preparation of polypropylene composition A:

[0248] Component a is a homopolymer polypropylene self-produced by the Beijing Research Institute of Chemical Industry of Sinopec, with a melting point of 165℃, a melt flow rate of 8.1 g / 10 min, and an isotacticity of 97%; component b is a polypropylene impact copolymer self-produced by the Beijing Research Institute of Chemical Industry of Sinopec, with an ethylene content of 8 wt%, a melting point of 155℃, a melt flow rate of 3.2 g / 10 min, and a cantilever beam impact strength of 25 KJ / m. 2 (23℃). Weigh and mix the components obtained above according to the proportions, wherein the mass fraction Wa of component a is 70 parts by weight, and the mass fraction Wb of component b is... n The sample consisted of 30 parts by weight. 0.05 parts by weight of β-crystal nucleating agent (brand name VP101B) was added. The mixture was then added to a high-speed mixer and mixed thoroughly. The mixed material was then fed into the feeder of a twin-screw extruder manufactured by W&P. The material entered the twin screws via the feeder. During processing, the screw temperature was maintained between 200-230°C. After being melted and mixed evenly by the screws, extruded, granulated, and dried, polypropylene composition granules A were obtained. The melting point of polypropylene composition granules A was tested to be 161°C.

[0249] (2) Polypropylene composition B i Preparation:

[0250] Component x1 is a random copolymer polypropylene produced by the Beijing Research Institute of Chemical Industry of Sinopec. It is an ethylene-propylene-butene terpolymer with a molecular weight distribution Mw / Mn of 8.4, a melting point of 128℃, and a melt flow rate of 7.8 g / 10 min. Component x2 is a random copolymer polypropylene produced by the Beijing Research Institute of Chemical Industry of Sinopec. It is an ethylene-propylene-butene terpolymer with a molecular weight distribution Mw / Mn of 7.6, a melting point of 134℃, and a melt flow rate of 6.9 g / 10 min. Component x3 is a random copolymer polypropylene produced by Sinopec Beijing Research Institute of Chemical Industry. It is an ethylene-propylene-butene terpolymer with a molecular weight distribution of Mw / Mn of 7.1, a melting point of 142℃, and a melt flow rate of 5.2 g / 10 min. Component y is a polyolefin elastomer produced by Sinopec Beijing Research Institute of Chemical Industry. It is an ethylene-propylene copolymer with an ethylene content of 15% wt, a melting point of 105℃, and a melt flow rate of 9 g / 10 min under a load of 2.16 kg.

[0251] The components obtained above are weighed and mixed according to the specified proportions, wherein component x i mass parts Wx i The weight of component y is 80 parts by weight, and the weight of component y (Wy) is 20 parts by weight. Other steps are the same as in step (1), and finally polypropylene composition B is obtained. i Granular material (i.e., x) i +y=B i (i = 1, 2, 3), after testing, the melting point of B1 is 126℃, the melting point of B2 is 133℃, and the melting point of B3 is 140℃.

[0252] (3) Preparation of three-layer co-extruded polypropylene sheets:

[0253] The preparation process is the same as step (3) of Example A1.

[0254] (4) Preparation of polypropylene fabric:

[0255] The preparation process is the same as step (4) of Example A1.

[0256] (5) Preparation of polypropylene composite materials:

[0257] The preparation process is the same as step (5) of Example A1.

[0258] The thickness of the prepared polypropylene composite material is similar to that of Example A1.

[0259] Example A3

[0260] This embodiment illustrates the preparation of the polypropylene composition, three-layer co-extruded polypropylene sheet, polypropylene fabric, and polypropylene composite material provided by the present invention.

[0261] (1) Preparation of polypropylene composition A:

[0262] Same as Example A1, wherein component a (Wa) has 90 parts by weight and component b (Wb) has 10 parts by weight. 0.05 parts by weight of a β-crystal nucleating agent (VP101B) are added. Polypropylene composition A granules are obtained, and the melting point of polypropylene composition granules A is measured to be 158°C.

[0263] (2) Polypropylene composition B i Preparation:

[0264] Same as in Example A1, wherein the corresponding component x i mass parts Wx i The final polypropylene composition B is obtained by using 90 parts by weight of component y and 10 parts by weight of component y. i Granular material (i.e., x) i +y=B i (i = 1, 2, 3), after testing, the melting point of B1 is 128℃, the melting point of B2 is 134℃, and the melting point of B3 is 139℃.

[0265] (3) Preparation of three-layer co-extruded polypropylene sheets:

[0266] The preparation process is the same as step (3) of Example A1.

[0267] (4) Preparation of polypropylene fabric:

[0268] The preparation process is the same as step (4) of Example A1.

[0269] (5) Preparation of polypropylene composite materials:

[0270] The preparation process is the same as step (5) of Example A1.

[0271] The thickness of the prepared polypropylene composite material is similar to that of Example A1.

[0272] Example A4

[0273] This embodiment illustrates the preparation of the polypropylene composition, three-layer co-extruded polypropylene sheet, polypropylene fabric, and polypropylene composite material provided by the present invention.

[0274] (1) Preparation of polypropylene composition A:

[0275] The preparation process is the same as step (1) of Example A1.

[0276] (2) Polypropylene composition B i Preparation:

[0277] The preparation process is the same as step (2) of Example A1.

[0278] (3) Preparation of three-layer co-extruded polypropylene sheets:

[0279] The main steps are the same as in Example A1. The polypropylene sheet is 80 μm thick, wherein the thickness of the film layer A accounts for 90% of the total sheet thickness.

[0280] (4) Preparation of polypropylene fabric:

[0281] The preparation process is the same as step (4) of Example A1.

[0282] (5) Preparation of polypropylene composite materials:

[0283] The preparation process is the same as step (5) of Example A1.

[0284] The thickness of the prepared polypropylene composite material is similar to that of Example A1.

[0285] Example A5

[0286] This embodiment illustrates the preparation of the polypropylene composition, three-layer co-extruded polypropylene sheet, polypropylene fabric, and polypropylene composite material provided by the present invention.

[0287] (1) Preparation of polypropylene composition A:

[0288] The preparation process is the same as step (1) of Example A1.

[0289] (2) Polypropylene composition B i Preparation:

[0290] The preparation process is the same as step (2) of Example A1.

[0291] (3) Preparation of three-layer co-extruded polypropylene sheets:

[0292] The main steps are the same as in Example A1. The polypropylene sheet is 80 μm thick, wherein the thickness of the film layer A accounts for 70% of the total sheet thickness.

[0293] (4) Preparation of polypropylene fabric:

[0294] The preparation process is the same as step (4) of Example A1.

[0295] (5) Preparation of polypropylene composite materials:

[0296] The preparation process is the same as step (5) of Example A1.

[0297] The thickness of the prepared polypropylene composite material is similar to that of Example A1.

[0298] Example A6

[0299] This embodiment illustrates the preparation of the polypropylene composition, three-layer co-extruded polypropylene sheet, polypropylene fabric, and polypropylene composite material provided by the present invention.

[0300] (1) Preparation of polypropylene composition A:

[0301] The preparation process is the same as step (1) of Example A1.

[0302] (2) Polypropylene composition B i Preparation:

[0303] The preparation process is the same as step (2) of Example A1.

[0304] (3) Preparation of three-layer co-extruded polypropylene sheets:

[0305] The preparation process is the same as step (3) of Example A1.

[0306] (4) Preparation of polypropylene fabric:

[0307] The main steps are the same as step (4) in Example A1. The oriented flat strip is woven into a satin polypropylene fabric by using a commercial weaving machine according to the designed fabric structure.

[0308] (5) Preparation of polypropylene composite materials:

[0309] The preparation process is the same as step (5) of Example A1.

[0310] The thickness of the prepared polypropylene composite material is similar to that of Example A1.

[0311] Example A7

[0312] This embodiment illustrates the preparation of the polypropylene composition, three-layer co-extruded polypropylene sheet, polypropylene fabric, and polypropylene composite material provided by the present invention.

[0313] (1) Preparation of polypropylene composition A:

[0314] The preparation process is the same as step (1) of Example A1.

[0315] (2) Polypropylene composition B i Preparation:

[0316] The preparation process is the same as step (2) of Example A1.

[0317] (3) Preparation of three-layer co-extruded polypropylene sheets:

[0318] The main preparation process is the same as step (3) of Example A1. The sheet stretching ratio is 10 times.

[0319] (4) Preparation of polypropylene fabric:

[0320] The preparation process is the same as step (4) of Example A1.

[0321] (5) Preparation of polypropylene composite materials:

[0322] The preparation process is the same as step (5) of Example A1.

[0323] The thickness of the prepared polypropylene composite material is similar to that of Example A1.

[0324] Example A8

[0325] This embodiment illustrates the preparation of the polypropylene composition, three-layer co-extruded polypropylene sheet, polypropylene fabric, and polypropylene composite material provided by the present invention.

[0326] (1) Preparation of polypropylene composition A:

[0327] The preparation process is the same as step (1) of Example A1.

[0328] (2) Polypropylene composition B i Preparation:

[0329] The preparation process is the same as step (2) of Example A1.

[0330] (3) Preparation of three-layer co-extruded polypropylene sheets:

[0331] The preparation process is the same as step (3) of Example A1.

[0332] (4) Preparation of polypropylene fabric:

[0333] The preparation process is the same as step (4) of Example A1.

[0334] (5) Preparation of polypropylene composite materials:

[0335] The main preparation process is the same as step (5) of Example A1. The polypropylene fabric is placed at a 45° angle between the warp and weft directions.

[0336] The thickness of the prepared polypropylene composite material is similar to that of Example A1.

[0337] Example A9

[0338] This embodiment illustrates the preparation of the polypropylene composition, three-layer co-extruded polypropylene sheet, polypropylene fabric, and polypropylene composite material provided by the present invention.

[0339] (1) Preparation of polypropylene composition A:

[0340] The preparation process is the same as step (1) of Example A1.

[0341] (2) Polypropylene composition Bi Preparation:

[0342] The preparation process is the same as step (2) of Example A1.

[0343] (3) Preparation of three-layer co-extruded polypropylene sheets:

[0344] The preparation process is the same as step (3) of Example A1.

[0345] (4) Preparation of polypropylene fabric:

[0346] The preparation process is the same as step (4) of Example A1.

[0347] (5) Preparation of polypropylene composite materials:

[0348] The main preparation process is the same as step (5) of Example A1. The polypropylene fabric is placed with the warp direction at 0° to the warp direction.

[0349] The thickness of the prepared polypropylene composite material is similar to that of Example A1.

[0350] Example A10

[0351] This embodiment illustrates the preparation of the polypropylene composition, three-layer co-extruded polypropylene sheet, polypropylene fabric, and polypropylene composite material provided by the present invention.

[0352] (1) Preparation of polypropylene composition A:

[0353] Same as Example A1, except that no β-crystal nucleating agent was added to component A.

[0354] (2) Preparation of polypropylene composition Bi:

[0355] Same as Example A1.

[0356] (3) Preparation of three-layer co-extruded polypropylene sheets:

[0357] The preparation process is the same as step (3) of Example A1.

[0358] (4) Preparation of polypropylene fabric:

[0359] The preparation process is the same as step (4) of Example A1.

[0360] (5) Preparation of polypropylene composite materials:

[0361] The preparation process is the same as step (5) of Example A1.

[0362] The thickness of the prepared polypropylene composite material is similar to that of Example A1.

[0363] Example A11

[0364] This embodiment illustrates the preparation of the polypropylene composition, five-layer co-extruded polypropylene composite sheet, polypropylene fabric, and polypropylene composite material provided by the present invention.

[0365] (1) Preparation of polypropylene composition A:

[0366] Component a is a homopolymer polypropylene self-produced by the Beijing Research Institute of Chemical Industry of Sinopec, with a melting point of 160℃, a melt flow rate (melt mass flow rate) of 3.2 g / 10 min, and an isotacticity of 97%; component b is a polypropylene impact copolymer self-produced by the Beijing Research Institute of Chemical Industry of Sinopec, with an ethylene content of 11 wt%, a melting point of 155℃, and a cantilever beam impact strength of 23 KJ / m. 2 (23℃), melt flow rate is 2.0 g / 10 min. The above-prepared components are weighed and mixed according to the proportions, wherein the mass fraction Wa of component a is 80 parts by weight and the mass fraction Wb of component b is 20 parts by weight.

[0367] Add 0.05 parts by weight of β-crystal nucleating agent of grade VP101B. Then, add the mixture to a high-speed mixer and mix evenly. Then, add the mixed material to the feeder of a twin-screw extruder manufactured by W&P. The material enters the twin screw through the feeder. During the processing, the screw temperature is maintained between 200-230°C. After being melted and mixed evenly by the screw, extruded, granulated and dried, polypropylene composition granules A are obtained. The melting point of polypropylene composition granules A is tested to be 157°C.

[0368] (2) Preparation of polypropylene composition B:

[0369] Component α is a polyolefin elastomer of grade 6102, purchased from ExxonMobil, and is an ethylene-propylene copolymer; the ethylene content is 16% wt (melt flow rate at 190℃ and 2.16 kg load is 1.4 g / 10 min); component β1 is a random copolymer polypropylene self-produced by the Beijing Research Institute of Chemical Industry of Sinopec, which is an ethylene-propylene-butene terpolymer with a molecular weight distribution Mw / Mn of 8.9, a melt flow rate of 8.1 g / 10 min, and a melting point of 130℃; component β2 is a random copolymer polypropylene self-produced by the Beijing Research Institute of Chemical Industry of Sinopec, which is an ethylene-propylene-butene terpolymer. The first component is an ethylene-propylene-butene terpolymer with a molecular weight distribution (Mw / Mn) of 7.6, a melt flow rate of 7.2 g / 10 min, and a melting point of 135 °C. The second component is a random copolymer polypropylene (rgPP) produced by the Beijing Research Institute of Chemical Industry of Sinopec, which is an ethylene-propylene-butene terpolymer with a molecular weight distribution (Mw / Mn) of 7.3, a melt flow rate of 6.6 g / 10 min, and a melting point of 140 °C. The third component is a homopolymer polypropylene (HPP) produced by the Beijing Research Institute of Chemical Industry of Sinopec, with a melt flow rate of 3.2 g / 10 min, a melting point of 160 °C, and an isotacticity of 97%.

[0370] The components obtained above are weighed and mixed according to the specified proportions, wherein the mass fraction W of component α is... α The weight percentage of component β is 45 parts by weight, W. β For 45 parts by weight, W γ The sample size is 10 parts by weight, and the other steps are the same as in step (1), finally yielding polypropylene composition B. i Granular material (i.e., α+β) i +γ=B i (i = 1, 2, 3), after testing, the melting point of B1 is 129℃, the melting point of B2 is 136℃, and the melting point of B3 is 141℃.

[0371] (3) Preparation of polypropylene composition C:

[0372] Component x1 is a random copolymer polypropylene produced by the Beijing Research Institute of Chemical Industry of Sinopec, which is an ethylene-propylene-butene terpolymer with a molecular weight distribution Mw / Mn of 8.9, a melt flow rate of 8.1 g / 10 min, and a melting point of 130℃; Component x2 is a random copolymer polypropylene produced by the Beijing Research Institute of Chemical Industry of Sinopec, which is an ethylene-propylene-butene terpolymer with a molecular weight distribution Mw / Mn of 7.6, a melt flow rate of 7.2 g / 10 min, and a melting point of 135℃; Component x3 is a random copolymer polypropylene produced by the Beijing Research Institute of Chemical Industry of Sinopec, with a molecular weight distribution Mw / Mn of 7.3, an ethylene-propylene-butene terpolymer with a melt flow rate of 6.6 g / 10 min, and a melting point of 140℃; Component y is a polyolefin elastomer of grade 6102, purchased from ExxonMobil, which is an ethylene-propylene copolymer.

[0373] The components obtained above are weighed and mixed according to the specified proportions, wherein component x i mass parts Wx i The weight percentage of component y is 85 parts by weight, and the weight percentage of component y (Wy) is 15 parts by weight. Other steps are the same as in step (1), and the final polypropylene composition C is obtained. i Granular material (i.e., x) i +y=C i (i = 1, 2, 3), after testing, the melting point of C1 is 127℃, the melting point of C2 is 132℃, and the melting point of C3 is 138℃.

[0374] (4) Preparation of five-layer co-extruded polypropylene composite sheet:

[0375] The polypropylene composition A, polypropylene composition B, and polymer C granules obtained in steps (1), (2), and (3) above are dried. Then, polypropylene composition A is added to the core extruder of a multi-layer extrusion calender, polypropylene composition B is added to the intermediate extruder of a multi-layer extrusion casting machine, and polypropylene composition C is added to the upper and lower surface extruders of a multi-layer extrusion casting machine. After the granules are co-extruded through the extruder die, they pass sequentially through calendering rollers and traction rollers, and then undergo solid-phase stretching, edge trimming, and winding to obtain the sheet material. The extrusion casting temperature is 230°C, and the calendering roller temperature is 60°C. The solid-phase stretching process is carried out at a temperature of 138°C, a stretching rate of 2 m / min, and a stretching ratio of 7 times.

[0376] After stretching and winding, a polypropylene composite sheet (composite film) is produced, which consists of an upper surface layer (film layer C). i ), intermediate layer (thin film layer B) i ), core layer (thin film layer A) i ), intermediate layer (thin film layer B) i ) and the lower surface layer (thin film layer C) i It consists of a polypropylene composite sheet with a thickness of 80 μm, in which the thin film layer A... i The thickness of film B accounts for 80% of the total thickness of the sheet. i The thickness of the film accounts for 10% of the total thickness of the sheet, and the film C i The thickness of this component accounts for 10% of the total thickness of the sheet.

[0377] (5) Preparation of polypropylene fabric:

[0378] The preparation process is the same as step (5) of Example A1.

[0379] (6) Preparation of polypropylene composite materials:

[0380] The preparation process is the same as step (6) of Example A1.

[0381] The thickness of the prepared polypropylene composite material is similar to that of Example A1.

[0382] Example A12

[0383] This embodiment illustrates the preparation of the polypropylene composition, three-layer co-extruded polypropylene sheet, polypropylene fabric, and polypropylene composite material provided by the present invention.

[0384] (1) Preparation of polypropylene composition A:

[0385] The preparation process is the same as step (1) of Example A1.

[0386] (2) Preparation of polypropylene composition B:

[0387] The main preparation process is the same as step (2) of Example A1. The difference is that component B... i and x i The materials selected are as follows:

[0388] Component x1 is a random copolymer polypropylene produced by the Beijing Research Institute of Chemical Industry of Sinopec, which is an ethylene-propylene-butene terpolymer with a melting point of 110℃; Component x2 is a random copolymer polypropylene produced by the Beijing Research Institute of Chemical Industry of Sinopec, which is an ethylene-propylene-butene terpolymer with a melting point of 115℃; Component x3 is a random copolymer polypropylene produced by the Beijing Research Institute of Chemical Industry of Sinopec, which is an ethylene-propylene-butene terpolymer with a melting point of 120℃; Component x4 is a random copolymer polypropylene produced by the Beijing Research Institute of Chemical Industry of Sinopec, which is an ethylene-propylene-butene terpolymer with a melting point of 125℃; Component x5 is a random copolymer polypropylene produced by the Beijing Research Institute of Chemical Industry of Sinopec, which is an ethylene-propylene-butene terpolymer with a melting point of 130℃; Component x Component 6 is a random copolymer polypropylene produced by the Beijing Research Institute of Chemical Industry of Sinopec, which is an ethylene-propylene-butene terpolymer with a melting point of 135℃; component x7 is a random copolymer polypropylene produced by the Beijing Research Institute of Chemical Industry of Sinopec, which is an ethylene-propylene-butene terpolymer with a melting point of 140℃; component x8 is a random copolymer polypropylene produced by the Beijing Research Institute of Chemical Industry of Sinopec, which is an ethylene-propylene-butene terpolymer with a melting point of 145℃; component x9 is a random copolymer polypropylene produced by the Beijing Research Institute of Chemical Industry of Sinopec, which is an ethylene-propylene-butene terpolymer with a melting point of 150℃; among them, the molecular weight distribution Mw / Mn of components x1-x9 are all between 7-10, and the melt flow rate of components x1-x9 are all between 1-20 g / 10 min.

[0389] Finally, polypropylene composition B was obtained. i Granular material (i.e., x) i +y=B i (i = 1, 2, 3, 4, 5, 6, 7, 8, 9). After testing, the melting point of B1 is 110℃, the melting point of B2 is 113℃, the melting point of B3 is 117℃, the melting point of B4 is 123℃, the melting point of B5 is 127℃, the melting point of B6 is 133℃, the melting point of B7 is 137℃, the melting point of B8 is 142℃, and the melting point of B9 is 148℃.

[0390] (3) Preparation of three-layer co-extruded polypropylene sheets:

[0391] The preparation process is the same as step (3) of Example A1.

[0392] (4) Preparation of polypropylene fabric:

[0393] The preparation process is the same as step (4) of Example A1.

[0394] (5) Preparation of polypropylene composite materials:

[0395] The polypropylene fabrics obtained in step (4) are stacked sequentially, from bottom to top as B9A9B. 9… The polypropylene fabrics, consisting of layers B3A3B3, B2A2B2, B1A1B1, B2A2B2, B3A3B3, ... B9A9B9, are stacked in a total of 17 layers. These stacked polypropylene fabrics are hot-pressed together and then cooled and shaped to form a polypropylene composite material. The polypropylene fabrics are placed at a 90° angle between the warp and weft directions. The hot-pressing conditions are: temperature 150℃, hot-pressing pressure 5MPa, preheating time 300s, hot-pressing time 180s, and cooling time 600s. The resulting polypropylene composite material has a thickness of 1.24mm.

[0396] Example A13

[0397] This embodiment illustrates the preparation of the polypropylene composition, three-layer co-extruded polypropylene sheet, polypropylene fabric, and polypropylene composite material provided by the present invention.

[0398] (1) Preparation of polypropylene composition A:

[0399] The preparation process is the same as step (1) of Example A1.

[0400] (2) Preparation of polypropylene composition B:

[0401] The main preparation process is the same as step (2) of Example A1. The difference is that component B... i and x i The materials selected are as follows:

[0402] Components x1-x3 are random copolymer polypropylenes produced by Sinopec Beijing Research Institute of Chemical Industry, which are ethylene-propylene-butene terpolymers with a melting point of 110℃; components x4-x6 are random copolymer polypropylenes produced by Sinopec Beijing Research Institute of Chemical Industry, which are ethylene-propylene-butene terpolymers with a melting point of 130℃; components x7-x9 are random copolymer polypropylenes produced by Sinopec Beijing Research Institute of Chemical Industry, which are ethylene-propylene-butene terpolymers with a melting point of 150℃; among them, the molecular weight distribution Mw / Mn of components x1-x9 are all between 7-10, and the melt flow rate of components x1-x9 is all between 1-20 g / 10 min.

[0403] Finally, polypropylene composition B was obtained. i Granular material (i.e., x) i +y=B i (i = 1, 2, 3, 4, 5, 6, 7, 8, 9...27). After testing, the melting point of B1-B3 is 110℃, the melting point of B4-B6 is 127℃, and the melting point of B7-B9 is 148℃.

[0404] (3) Preparation of three-layer co-extruded polypropylene sheets:

[0405] The preparation process is the same as step (3) of Example A1.

[0406] (4) Preparation of polypropylene fabric:

[0407] The preparation process is the same as step (4) of Example A1.

[0408] (5) Preparation of polypropylene composite materials:

[0409] The polypropylene fabrics obtained in step (4) are stacked sequentially, from bottom to top as B9A9B. 9… The polypropylene fabrics, consisting of layers B3A3B3, B2A2B2, B1A1B1, B2A2B2, B3A3B3, ... B9A9B9, are stacked in a total of 17 layers. These stacked polypropylene fabrics are hot-pressed together and then cooled and shaped to form a polypropylene composite material. The polypropylene fabrics are placed at a 90° angle between the warp and weft directions. The hot-pressing conditions are: temperature 150℃, hot-pressing pressure 5MPa, preheating time 300s, hot-pressing time 180s, and cooling time 600s. The resulting polypropylene composite material has a thickness of 1.24mm.

[0410] Example A14

[0411] This embodiment illustrates the preparation of the polypropylene composition, three-layer co-extruded polypropylene sheet, polypropylene fabric, and polypropylene composite material provided by the present invention.

[0412] (1) Preparation of polypropylene composition A:

[0413] The preparation process is the same as step (1) of Example A1.

[0414] (2) Preparation of polypropylene composition B:

[0415] The preparation process is the same as step (2) of Example A1.

[0416] (3) Preparation of three-layer co-extruded polypropylene sheets:

[0417] The preparation process is the same as step (3) of Example A1.

[0418] (4) Preparation of polypropylene fabric:

[0419] The preparation process is the same as step (4) of Example A1.

[0420] (5) Preparation of polypropylene composite materials:

[0421] The main steps are the same as in Example A1. The difference is that the hot-pressing conditions are changed to: temperature 150°C, hot-pressing pressure 8 MPa, preheating time 180 s, hot-pressing time 180 s, and cooling time 700 s. The thickness of the prepared polypropylene composite material is 387 μm.

[0422] Example A15

[0423] This embodiment illustrates the preparation of the polypropylene composition, three-layer co-extruded polypropylene sheet, polypropylene fabric, and polypropylene composite material provided by the present invention.

[0424] (1) Preparation of polypropylene composition A:

[0425] The preparation process is the same as step (1) of Example A1.

[0426] (2) Preparation of polypropylene composition B:

[0427] The main preparation process is the same as step (2) of Example A1, except that component B... i and x i The materials selected are as follows:

[0428] Component x1 is a random copolymer polypropylene produced by the Beijing Research Institute of Chemical Industry of Sinopec, which is an ethylene-propylene-butene terpolymer with a melting point of 110℃; Component x2 is a random copolymer polypropylene produced by the Beijing Research Institute of Chemical Industry of Sinopec, which is an ethylene-propylene-butene terpolymer with a melting point of 130℃; Component x3 is a random copolymer polypropylene produced by the Beijing Research Institute of Chemical Industry of Sinopec, which is an ethylene-propylene-butene terpolymer with a melting point of 150℃. The molecular weight distribution (Mw / Mn) of components x1-x3 is all between 7 and 10, and the melt flow rate of components x1-x3 is all between 1 and 20 g / 10 min.

[0429] Finally, polypropylene composition B was obtained. i Granular material (i.e., x) i +y=B i (i = 1, 2, 3), after testing, the melting point of B1 is 110℃, the melting point of B2 is 128℃, and the melting point of B3 is 147℃.

[0430] (3) Preparation of three-layer co-extruded polypropylene sheets:

[0431] The preparation process is the same as step (3) of Example A1.

[0432] (4) Preparation of polypropylene fabric:

[0433] The preparation process is the same as step (4) of Example A1.

[0434] (5) Preparation of polypropylene composite materials:

[0435] The preparation process is the same as step (5) of Example A1.

[0436] The thickness of the prepared polypropylene composite material is similar to that of Example A1.

[0437] Example A16

[0438] This embodiment illustrates the preparation of the polypropylene composition, three-layer co-extruded polypropylene sheet, polypropylene fabric, and polypropylene composite material provided by the present invention.

[0439] (1) Preparation of polypropylene composition A:

[0440] The preparation process is the same as step (1) of Example A1.

[0441] (2) Preparation of polypropylene composition B:

[0442] The preparation process is the same as step (2) of Example A1.

[0443] (3) Preparation of three-layer co-extruded polypropylene sheets:

[0444] The preparation process is the same as step (3) of Example A1.

[0445] (4) Preparation of polypropylene composite materials:

[0446] Instead of preparing the polypropylene fabric, the three-layer co-extruded polypropylene sheet obtained in step (3) is used to replace the polypropylene fabric obtained in step (4) of Example A1 and then sequentially stacked and hot-pressed according to step (5) of Example A1.

[0447] The thickness of the resulting polypropylene composite material is similar to that of Example A1.

[0448] Example A17

[0449] This embodiment illustrates the preparation of the polypropylene composition, three-layer co-extruded polypropylene sheet, polypropylene fabric, and polypropylene composite material provided by the present invention.

[0450] (1) Preparation of polypropylene composition A:

[0451] The preparation process is the same as step (1) of Example A1.

[0452] (2) Preparation of polypropylene composition B:

[0453] The main preparation process is the same as step (2) of Example A1. The difference is that component B... i and x i The materials selected are as follows:

[0454] Components x1-x3 are random copolymer polypropylene produced by the Beijing Research Institute of Chemical Industry, Sinopec, which is an ethylene-propylene-butene terpolymer with a melting point of 110℃; components x4-x6 are random copolymer polypropylene produced by the Beijing Research Institute of Chemical Industry, Sinopec, which is an ethylene-propylene-butene terpolymer with a melting point of 115℃; components x7-x9 are random copolymer polypropylene produced by the Beijing Research Institute of Chemical Industry, Sinopec, which is an ethylene-propylene-butene terpolymer with a melting point of 120℃; component x 10 -x 12 This is a random copolymer polypropylene produced by the Beijing Research Institute of Chemical Industry of Sinopec. It is an ethylene-propylene-butene terpolymer with a melting point of 125℃; component x 13 -x 15 This is a random copolymer polypropylene produced by the Beijing Research Institute of Chemical Industry of Sinopec. It is an ethylene-propylene-butene terpolymer with a melting point of 130℃; component x 16 -x 18 This is a random copolymer polypropylene, produced by the Beijing Research Institute of Chemical Industry of Sinopec, which is an ethylene-propylene-butene terpolymer with a melting point of 135℃; component x 19 -x 21 This is a random copolymer polypropylene produced by the Beijing Research Institute of Chemical Industry of Sinopec. It is an ethylene-propylene-butene terpolymer with a melting point of 140℃; component x 22 -x 24 This is a random copolymer polypropylene produced by the Beijing Research Institute of Chemical Industry of Sinopec. It is an ethylene-propylene-butene terpolymer with a melting point of 145℃; component x 25 -x 27 This is a random copolymer polypropylene produced by the Beijing Research Institute of Chemical Industry of Sinopec. It is an ethylene-propylene-butene terpolymer with a melting point of 150℃; wherein, components x1-x 27 The molecular weight distribution Mw / Mn is between 7 and 10, and the components x1-x 27 The melt flow rates are all between 1 and 20 g / 10 min.

[0455] Finally, polypropylene composition B was obtained. i Granular material (i.e., x) i +y=B i (i = 1, 2, 3, 4, 5, 6, 7, 8, 9...27), after testing, the melting point of B1-B3 is 110℃, the melting point of B4-B6 is 113℃, the melting point of B7-B9 is 117℃, B... 10 -B 12 The melting point of B is 123℃. 13 -B 15 The melting point of B is 127℃. 16 -B 18 The melting point of B is 133℃. 19 -B 21The melting point of B is 137℃. 22 -B 24 The melting point of B is 142℃. 25 -B 27 Its melting point is 148℃.

[0456] (3) Preparation of three-layer co-extruded polypropylene sheets:

[0457] The preparation process is the same as step (3) of Example A1.

[0458] (4) Preparation of polypropylene fabric:

[0459] The preparation process is the same as step (4) of Example A1.

[0460] (5) Preparation of polypropylene composite materials:

[0461] The polypropylene fabrics obtained in step (4) above are stacked sequentially, from bottom to top as B. 27 A 27 B 27... B9A9B 9… B3A3B3, B2A2B2, B1A1B1, B2A2B2, B3A3B3,…B9A9B9…B 27 A 27 B 27 The total number of layers is 53. The laminated polypropylene fabrics are hot-pressed and fused together, then cooled and shaped to form a polypropylene composite material. The polypropylene fabrics are placed at a 90° angle between the warp and weft directions. The hot-pressing conditions are: temperature 150℃, hot-pressing pressure 5MPa, preheating time 500s, hot-pressing time 360s, and cooling time 800s. The prepared polypropylene composite material has a thickness of 3.92mm.

[0462] Example A18

[0463] Co-extruded polypropylene sheets were prepared according to the method of Example A1, except that component Bi was selected as follows: component x1 was a random copolymer polypropylene self-produced by the Beijing Research Institute of Chemical Industry of Sinopec, which was an ethylene-propylene-butene terpolymer with a molecular weight distribution Mw / Mn of 4.2 and a melting point of 142°C; component x2 was a random copolymer polypropylene self-produced by the Beijing Research Institute of Chemical Industry of Sinopec, which was an ethylene-propylene-butene terpolymer with a molecular weight distribution Mw / Mn of 4.7 and a melting point of 138°C; component x3 was a random copolymer polypropylene self-produced by the Beijing Research Institute of Chemical Industry of Sinopec, which was an ethylene-propylene-butene terpolymer with a molecular weight distribution Mw / Mn of 5.4 and a melting point of 133°C; the melt flow rates of components x1-x3 were all 2-10 g / 10 min.

[0464] Finally, polypropylene composition B was obtained.i Granular material (i.e., x) i +y=B i (i = 1, 2, 3), after testing, the melting point of B1 is 139℃, the melting point of B2 is 134℃, and the melting point of B3 is 129℃.

[0465] Comparative Example A1

[0466] Co-extruded polypropylene sheets were prepared according to the method of Example A1, except that component Bi was selected as follows: component x1 was a random copolymer polypropylene self-made by Sinopec Beijing Chemical Research Institute, which was an ethylene-propylene-butene terpolymer with a melting point of 140°C; component x2 was a random copolymer polypropylene self-made by Sinopec Beijing Chemical Research Institute, which was an ethylene-propylene-butene terpolymer with a melting point of 135°C; component x3 was a random copolymer polypropylene self-made by Sinopec Beijing Chemical Research Institute, which was an ethylene-propylene-butene terpolymer with a melting point of 130°C; the molecular weight distribution Mw / Mn of components x1-x3 were all between 7-10, and the melt flow rate of components x1-x3 was all between 2-10 g / 10 min.

[0467] Finally, polypropylene composition B was obtained. i Granular material (i.e., x) i +y=B i (i = 1, 2, 3), after testing, the melting point of B1 is 138℃, the melting point of B2 is 132℃, and the melting point of B3 is 127℃.

[0468] Comparative Example A2

[0469] Three-layer co-extruded polypropylene sheets were prepared according to the method of Example A1. Only polypropylene composition B... i It contains only component y.

[0470] Polypropylene fabrics and polypropylene composites were prepared according to the method of Example A1.

[0471] Comparative Example A3

[0472] A three-layer co-extruded polypropylene sheet was prepared according to the method of Example A1. The only difference was that the thickness of film layer A accounted for 95% of the total sheet thickness. Polypropylene fabrics and polypropylene composites were also prepared according to the method of Example A1.

[0473] Comparative Example A4

[0474] A three-layer co-extruded polypropylene sheet was prepared according to the method of Example A1. The only difference was that the thickness of film layer A accounted for 50% of the total sheet thickness. Polypropylene fabrics and polypropylene composites were also prepared according to the method of Example A1.

[0475] Comparative Example A5

[0476] Co-extruded polypropylene sheets (17 layers) were prepared according to the method of Example A12, except that component B... i The materials were selected as follows: components x1-x9 were random copolymer polypropylene produced by the Beijing Research Institute of Chemical Industry of Sinopec, with a melting point of 110℃; and the molecular weight distribution Mw / Mn of components x1-x9 were all between 7 and 10, and the melt flow rate of components x1-x9 was all between 2 and 10 g / 10 min.

[0477] Finally, polypropylene composition B was obtained. i Granular material, after testing, B i Its melting point is 110℃.

[0478] The hot-pressing conditions used were: temperature 150℃, hot-pressing pressure 5MPa, preheating time 300s, hot-pressing time 180s, and cooling time 600s. The prepared polypropylene composite material had a thickness of 1.24mm.

[0479] Comparative Example A6

[0480] Co-extruded polypropylene sheets (17 layers) were prepared according to the method of Example A12, except that component Bi was selected as follows: components x1-x9 were random copolymer polypropylene produced by Sinopec Beijing Research Institute of Chemical Industry, with a melting point of 130°C; and the molecular weight distribution Mw / Mn of components x1-x9 were all between 7 and 10, and the melt flow rate of components x1-x9 was all between 2 and 10 g / 10 min.

[0481] Finally, polypropylene composition B was obtained. i Granular material, after testing, B i Its melting point is 127℃.

[0482] The hot-pressing conditions used were: temperature 150℃, hot-pressing pressure 5MPa, preheating time 300s, hot-pressing time 180s, and cooling time 600s. The prepared polypropylene composite material had a thickness of 1.24mm.

[0483] Comparative Example A7

[0484] Co-extruded polypropylene sheets (17 layers) were prepared according to the method of Example A12, except that component Bi was selected as follows: components x1-x9 were random copolymer polypropylene produced by Sinopec Beijing Chemical Research Institute with a melting point of 150°C; and the molecular weight distribution Mw / Mn of components x1-x9 were all between 7 and 10, and the melt flow rate of components x1-x9 was all between 2 and 10 g / 10 min.

[0485] Finally, polypropylene composition B was obtained. i Granular material, after testing, B i Its melting point is 148℃.

[0486] The hot-pressing conditions used were: temperature 150℃, hot-pressing pressure 5MPa, preheating time 300s, hot-pressing time 180s, and cooling time 600s. The prepared polypropylene composite material had a thickness of 1.24mm.

[0487] Experimental Example

[0488] The polypropylene composite materials obtained in the above examples and comparative examples were tested according to the following methods, and the test results are shown in Table 1:

[0489] (1) Sheet tensile strength: determined according to the method specified in GB / T1040.1-2018;

[0490] (2) Drop hammer impact strength: determined according to the method specified in GB / T14153-1993;

[0491] (3) Interlayer peel strength: The strength was determined according to the method specified in QB / T2358-98. Among them, the thickness of the polypropylene composite materials obtained in Examples A1-9, 12, 13 and Comparative Examples A1-4 were all similar, around 390 μm, and all within the range of 390 μm ± 10 μm.

[0492] Table 1

[0493]

[0494]

[0495] The results of the examples in Table 1 show that the polypropylene composite material with a melting point gradient structure prepared according to the present invention has both good tensile properties and impact resistance, and also has good interlaminar peel strength at a relatively low hot-pressing temperature.

[0496] The longitudinal (MD) tensile strength of the polypropylene composite material with melting point gradient structure described in this invention is ≥160MPa, and the interlaminar peel strength is ≥1.3N / mm; when the composite material is made of only 5 layers of polypropylene fabric hot-pressed together and the thickness is only about 390μm, the drop hammer impact strength is ≥42J.

[0497] As can be seen from the preferred embodiments A1-3, the longitudinal (MD) tensile strength of the polypropylene composite material with melting point gradient structure prepared by the present invention is ≥180MPa, and the interlaminar peel strength is ≥1.5N / mm; when the composite material is only 5 layers of polypropylene fabric hot-pressed together and only about 390μm thick, the drop hammer impact strength is ≥45J.

[0498] As can be seen from Comparative Examples A1-8, polypropylene composite materials prepared using methods outside the scope of this invention will lead to a decrease in the properties of laminated polypropylene sheets or fabrics, resulting in a significant decrease in the tensile strength, impact properties, or interlaminar peel strength of the obtained polypropylene composite materials.

[0499] In particular, a comparison of Comparative Examples A5-7 and Example A12 shows that, compared with conventional non-gradient melting point polypropylene composites, the polypropylene composites of the present invention with a melting point gradient structure exhibit higher tensile strength, impact properties, and interlaminar peel strength. Compared with conventional non-gradient melting point polypropylene composites, the polypropylene composites of the present invention with a melting point gradient structure require shorter hot-pressing times or lower hot-pressing temperatures during processing. It is believed that reducing the hot-pressing time or temperature can reduce the damage to mechanical properties caused by molecular chain disorientation. In addition, reducing the hot-pressing time or temperature can also achieve the beneficial effect of cost reduction and efficiency improvement.

[0500] Example B1

[0501] This embodiment illustrates the preparation of the polypropylene composition, three-layer co-extruded polypropylene sheet, polypropylene fabric, and polypropylene composite material provided by the present invention.

[0502] (1) Preparation of polypropylene composition A:

[0503] Component a is a homopolymer polypropylene self-produced by the Beijing Research Institute of Chemical Industry, Sinopec, with a melting point of 160℃, a melt flow rate (melt mass flow rate) of 3.2 g / 10 min, and an isotacticity of 97%; component b is a polypropylene impact copolymer self-produced by the Beijing Research Institute of Chemical Industry, Sinopec (with a cantilever beam impact strength of 23 KJ / m under 23℃ testing conditions). 2 The ethylene content is 11% wt, the melt flow rate is 2.0 g / 10 min, and the melting point is 155℃.

[0504] The components obtained above were weighed and mixed according to the specified proportions, with component a (Wa) comprising 80 parts by weight and component b (Wb) comprising 20 parts by weight. 0.05 parts by weight of β-crystal nucleating agent (VP101B) were added. The mixture was then added to a high-speed mixer and mixed thoroughly. The mixed material was then fed into the feeder of a twin-screw extruder manufactured by W&P. The material entered the twin screws via the feeder. During processing, the screw temperature was maintained between 200-230°C. After melting and mixing evenly in the screws, extrusion, granulation, and drying, polypropylene composition granules were obtained. The melt flow rate was measured to be 4.6 g / 10 min; the melting point of polypropylene composition A was 157°C.

[0505] (2) Preparation of polypropylene composition B:

[0506] Component x is a random copolymer polypropylene produced by the Beijing Research Institute of Chemical Industry of Sinopec. It is an ethylene-propylene-butene terpolymer with a molecular weight distribution of Mw / Mn of 7.3, a melting point of 140℃, and a melt flow rate of 6.6 g / 10 min. Component y is a polyolefin elastomer of grade 6102 purchased from ExxonMobil. It is an ethylene-propylene copolymer with an ethylene content of 16% wt. Its melt flow rate at 190℃ and 2.16 kg load is 1.4 g / 10 min.

[0507] The components prepared above are weighed and mixed according to the ratio, wherein the mass part of component x, Wx, is 85 parts by weight, the mass part of component y, Wy, is 15 parts by weight, and the other steps are the same as in step (1). Finally, polypropylene composition B granules are obtained. The melt mass flow rate is tested to be 5.2 g / 10 min, and the melting point is 138 °C.

[0508] (3) Preparation of three-layer co-extruded polypropylene sheets:

[0509] The polypropylene composition A and polypropylene composition B granules obtained in steps (1) and (2) above are dried. Then, polypropylene composition A is added to the core extruder of a multilayer extrusion calender, and polypropylene composition B is added to the upper and lower surface extruders of a multilayer extrusion casting machine.

[0510] After the granules are co-extruded and compounded through the die of an extruder, they pass through calendering rollers and traction rollers in sequence, and then undergo solid-phase stretching, edge trimming and winding to obtain the sheet material.

[0511] The extrusion casting temperature is 230℃, and the calendering roll temperature is 55℃. The solid-phase stretching process is carried out at a temperature of 135℃, a stretching rate of 2 m / min, and a stretching ratio of 7 times. After stretching, the film is wound up to form a polypropylene sheet (composite film), which consists of an upper surface layer (film layer B), a core layer (film layer A), and a lower surface layer (film layer B).

[0512] The thickness of the polypropylene sheet (composite film) mentioned above is 80 μm, wherein the thickness of film layer A accounts for 80% of the total thickness of the sheet.

[0513] (4) Preparation of polypropylene fabric:

[0514] The three-layer co-extruded polypropylene sheet obtained in step (3) above is cut into a high-speed slitting machine with multiple blades to obtain an oriented polypropylene flat strip with a width of 3mm; the oriented flat strip is woven into a plain weave polypropylene fabric according to the designed fabric structure using a commercial weaving machine.

[0515] (5) Preparation of polypropylene composite materials:

[0516] The polypropylene fabrics obtained in step (4) were sequentially stacked and hot-pressed to form a laminated polypropylene sheet. The laminated polypropylene sheet consisted of 24 layers of polypropylene fabric, with the warp and weft directions arranged at 90° angles. The hot-pressing conditions were: temperature 150℃, hot-pressing pressure 5MPa, preheating time 180s, hot-pressing time 180s, and cooling time 600s. The thickness of the prepared polypropylene composite material was 1.67mm.

[0517] Example B2

[0518] This embodiment illustrates the preparation of the polypropylene composition, three-layer co-extruded polypropylene sheet, polypropylene fabric, and polypropylene composite material provided by the present invention.

[0519] (1) Preparation of polypropylene composition A:

[0520] Component a is a homopolymer polypropylene self-produced by the Beijing Research Institute of Chemical Industry of Sinopec, with a melting point of 165℃, a melt flow rate of 8.1 g / 10 min, and an isotacticity of 97%; component b is a polypropylene impact copolymer self-produced by the Beijing Research Institute of Chemical Industry of Sinopec, with a cantilever beam impact strength of 25 KJ / m under a test condition of 23℃. 2 The ethylene content is 8% wt, the melt flow rate is 3.2 g / 10 min, and the melting point is 155℃.

[0521] The components obtained above were weighed and mixed according to the specified proportions, with component a (Wa) comprising 70 parts by weight and component b (Wb) comprising 30 parts by weight. 0.05 parts by weight of β-crystal nucleating agent (VP101B) were added. The mixture was then added to a high-speed mixer and mixed thoroughly. The mixed material was then fed into the feeder of a twin-screw extruder manufactured by W&P. The material entered the twin screws via the feeder. During processing, the screw temperature was maintained between 200-230°C. After melting and mixing evenly in the screws, extrusion, granulation, and drying, polypropylene composition granules were obtained. The melt flow rate was measured to be 7.3 g / 10 min, and the melting point of polypropylene composition A was 161°C.

[0522] (2) Preparation of polypropylene composition B:

[0523] Component x is a random copolymer polypropylene produced by Sinopec Beijing Research Institute of Chemical Industry, with a melting point of 134℃. It is an ethylene-propylene-butene terpolymer with a molecular weight distribution of Mw / Mn of 7.6 and a melt flow rate of 5.2 g / 10 min. Component y is a polyolefin elastomer produced by Sinopec Beijing Research Institute of Chemical Industry, which is an ethylene-propylene copolymer with an ethylene content of 15% wt. It has a melting point of 105℃ and a melt flow rate of 9 g / 10 min at 190℃ and a load of 2.16 kg.

[0524] The components obtained above were weighed and mixed according to the specified proportions, wherein component x (Wx) had a mass fraction of 80 parts by weight and component y had a mass fraction of 20 parts by weight. Other steps were the same as in step (1). Finally, polypropylene composition B granules were obtained, and its melt flow rate was measured to be 9.6 g / 10 min. The melting point of polypropylene composition B is 130 °C.

[0525] (3) Preparation of three-layer co-extruded polypropylene sheets:

[0526] The preparation process is the same as step (3) of Example B1.

[0527] (4) Preparation of polypropylene fabric:

[0528] The preparation process is the same as step (4) of Example B1.

[0529] (5) Preparation of polypropylene composite materials:

[0530] The preparation process is the same as step (5) of Example B1.

[0531] The thickness of the prepared polypropylene composite material is similar to that of Example B1.

[0532] Example B3

[0533] This embodiment illustrates the preparation of the polypropylene composition, three-layer co-extruded polypropylene sheet, polypropylene fabric, and polypropylene composite material provided by the present invention.

[0534] (1) Preparation of polypropylene composition A:

[0535] Same as Example B1, wherein component a (Wa) has 90 parts by weight and component b (Wb) has 10 parts by weight. 0.05 parts by weight of β-crystal nucleating agent (VP101B) are added. Polypropylene composition A granules are obtained, with a melt flow rate of 6.8 g / 10 min and a melting point of 158°C.

[0536] (2) Preparation of polypropylene composition B:

[0537] Same as Example B1, wherein the mass fraction of component x, Wx, is 90 parts by weight and the mass fraction of component y, Wy, is 10 parts by weight, and finally polypropylene composition B granules are obtained. The melt flow rate is tested to be 8.7 g / 10 min and the melting point of polypropylene composition B is 139 °C.

[0538] (3) Preparation of three-layer co-extruded polypropylene sheets:

[0539] The preparation process is the same as step (3) of Example B1.

[0540] (4) Preparation of polypropylene fabric:

[0541] The preparation process is the same as step (4) of Example B1.

[0542] (5) Preparation of polypropylene composite materials:

[0543] The preparation process is the same as step (5) of Example B1.

[0544] The thickness of the prepared polypropylene composite material is similar to that of Example B1.

[0545] Example B4

[0546] This embodiment illustrates the preparation of the polypropylene composition, three-layer co-extruded polypropylene sheet, polypropylene fabric, and polypropylene composite material provided by the present invention.

[0547] (1) Preparation of polypropylene composition A:

[0548] The preparation process is the same as step (1) of Example B1.

[0549] (2) Preparation of polypropylene composition B:

[0550] The preparation process is the same as step (2) of Example B1.

[0551] (3) Preparation of three-layer co-extruded polypropylene sheets:

[0552] The main steps are the same as in Example B1. The thickness of the polypropylene sheet is 80 μm, wherein the thickness of the film layer A accounts for 90% of the total thickness of the sheet.

[0553] (4) Preparation of polypropylene fabric:

[0554] The preparation process is the same as step (4) of Example B1.

[0555] (5) Preparation of polypropylene composite materials:

[0556] The preparation process is the same as step (5) of Example B1.

[0557] The thickness of the prepared polypropylene composite material is similar to that of Example B1.

[0558] Example B5

[0559] This embodiment illustrates the preparation of the polypropylene composition, three-layer co-extruded polypropylene sheet, polypropylene fabric, and polypropylene composite material provided by the present invention.

[0560] (1) Preparation of polypropylene composition A:

[0561] The preparation process is the same as step (1) of Example B1.

[0562] (2) Preparation of polypropylene composition B:

[0563] The preparation process is the same as step (2) of Example B1.

[0564] (3) Preparation of three-layer co-extruded polypropylene sheets:

[0565] The main steps are the same as in Example B1. The thickness of the polypropylene sheet is 80 μm, wherein the thickness of the film layer A accounts for 70% of the total thickness of the sheet.

[0566] (4) Preparation of polypropylene fabric:

[0567] The preparation process is the same as step (4) of Example B1.

[0568] (5) Preparation of polypropylene composite materials:

[0569] The preparation process is the same as step (5) of Example B1.

[0570] The thickness of the prepared polypropylene composite material is similar to that of Example B1.

[0571] Example B6

[0572] This embodiment illustrates the preparation of the polypropylene composition, three-layer co-extruded polypropylene sheet, polypropylene fabric, and polypropylene composite material provided by the present invention.

[0573] (1) Preparation of polypropylene composition A:

[0574] The preparation process is the same as step (1) of Example B1.

[0575] (2) Preparation of polypropylene composition B:

[0576] The preparation process is the same as step (2) of Example B1.

[0577] (3) Preparation of three-layer co-extruded polypropylene sheets:

[0578] The preparation process is the same as step (3) of Example B1.

[0579] (4) Preparation of polypropylene fabric:

[0580] The main steps are the same as step (4) in Example B1. The oriented flat strip is woven into a satin polypropylene fabric by using a commercial weaving machine according to the designed fabric structure.

[0581] (5) Preparation of polypropylene composite materials:

[0582] The preparation process is the same as step (5) of Example B1.

[0583] The thickness of the prepared polypropylene composite material is similar to that of Example B1.

[0584] Example B7

[0585] This embodiment illustrates the preparation of the polypropylene composition, three-layer co-extruded polypropylene sheet, polypropylene fabric, and polypropylene composite material provided by the present invention.

[0586] (1) Preparation of polypropylene composition A:

[0587] The preparation process is the same as step (1) of Example B1.

[0588] (2) Preparation of polypropylene composition B:

[0589] The preparation process is the same as step (2) of Example B1.

[0590] (3) Preparation of three-layer co-extruded polypropylene sheets:

[0591] The main preparation process is the same as step (3) of Example B1. The sheet stretching ratio is 10 times.

[0592] (4) Preparation of polypropylene fabric:

[0593] The preparation process is the same as step (4) of Example B1.

[0594] (5) Preparation of polypropylene composite materials:

[0595] The preparation process is the same as step (5) of Example B1.

[0596] The thickness of the prepared polypropylene composite material is similar to that of Example B1.

[0597] Example B8

[0598] This embodiment illustrates the preparation of the polypropylene composition, three-layer co-extruded polypropylene sheet, polypropylene fabric, and polypropylene composite material provided by the present invention.

[0599] (1) Preparation of polypropylene composition A:

[0600] The preparation process is the same as step (1) of Example B1.

[0601] (2) Preparation of polypropylene composition B:

[0602] The preparation process is the same as step (2) of Example B1.

[0603] (3) Preparation of three-layer co-extruded polypropylene sheets:

[0604] The preparation process is the same as step (3) of Example B1.

[0605] (4) Preparation of polypropylene fabric:

[0606] The preparation process is the same as step (4) of Example B1.

[0607] (5) Preparation of polypropylene composite materials:

[0608] The main preparation process is the same as step (5) of Example B1. The polypropylene fabric is placed at a 45° angle between the warp and weft directions.

[0609] The thickness of the prepared polypropylene composite material is similar to that of Example B1.

[0610] Example B9

[0611] This embodiment illustrates the preparation of the polypropylene composition, three-layer co-extruded polypropylene sheet, polypropylene fabric, and polypropylene composite material provided by the present invention.

[0612] (1) Preparation of polypropylene composition A:

[0613] The preparation process is the same as step (1) of Example B1.

[0614] (2) Preparation of polypropylene composition B:

[0615] The preparation process is the same as step (2) of Example B1.

[0616] (3) Preparation of three-layer co-extruded polypropylene sheets:

[0617] The preparation process is the same as step (3) of Example B1.

[0618] (4) Preparation of polypropylene fabric:

[0619] The preparation process is the same as step (4) of Example B1.

[0620] (5) Preparation of polypropylene composite materials:

[0621] The main preparation process is the same as step (5) of Example B1. The polypropylene fabric is placed with the warp direction at 0° to the warp direction.

[0622] The thickness of the prepared polypropylene composite material is similar to that of Example B1.

[0623] Example B10

[0624] This embodiment illustrates the preparation of the polypropylene composition, three-layer co-extruded polypropylene sheet, polypropylene fabric, and polypropylene composite material provided by the present invention.

[0625] (1) Preparation of polypropylene composition A:

[0626] The preparation process is the same as step (1) of Example B1.

[0627] (2) Preparation of polypropylene composition B:

[0628] The preparation process is the same as step (2) of Example B1.

[0629] (3) Preparation of three-layer co-extruded polypropylene sheets:

[0630] The preparation process is the same as step (3) of Example B1.

[0631] (4) Preparation of polypropylene fabric:

[0632] The preparation process is the same as step (4) of Example B1.

[0633] (5) Preparation of polypropylene composite materials:

[0634] The main steps are the same as in Example B1. The laminated polypropylene sheet includes two layers of polypropylene fabric. The hot-pressing conditions used are: temperature 140°C, hot-pressing pressure 2 MPa, preheating time 120 s, hot-pressing time 10 s, and cooling time 300 s. The thickness of the prepared polypropylene composite material is 128 μm.

[0635] Example B11

[0636] This embodiment illustrates the preparation of the polypropylene composition, three-layer co-extruded polypropylene sheet, polypropylene fabric, and polypropylene composite material provided by the present invention.

[0637] (1) Preparation of polypropylene composition A:

[0638] The preparation process is the same as step (1) of Example B1.

[0639] (2) Preparation of polypropylene composition B:

[0640] The preparation process is the same as step (2) of Example B1.

[0641] (3) Preparation of three-layer co-extruded polypropylene sheets:

[0642] The preparation process is the same as step (3) of Example B1.

[0643] (4) Preparation of polypropylene fabric:

[0644] The preparation process is the same as step (4) of Example B1.

[0645] (5) Preparation of polypropylene composite materials:

[0646] The main steps are the same as in Example B1. The laminated polypropylene sheet comprises 100 layers of polypropylene fabric. The hot-pressing conditions used are: 159°C, hot-pressing pressure of 10 MPa, preheating time of 300 s, hot-pressing time of 300 s, and cooling time of 700 s. The thickness of the prepared polypropylene composite material is 7.23 mm.

[0647] Example B12

[0648] This embodiment illustrates the preparation of the polypropylene composition, three-layer co-extruded polypropylene sheet, polypropylene fabric, and polypropylene composite material provided by the present invention.

[0649] (1) Preparation of polypropylene composition A:

[0650] The preparation process is the same as step (1) of Example B1.

[0651] (2) Preparation of polypropylene composition B:

[0652] The preparation process is the same as step (2) of Example B1.

[0653] (3) Preparation of three-layer co-extruded polypropylene sheets:

[0654] The preparation process is the same as step (3) of Example B1.

[0655] (4) Preparation of polypropylene fabric:

[0656] The preparation process is the same as step (4) of Example B1.

[0657] (5) Preparation of polypropylene composite materials:

[0658] The main steps are the same as in Example B1. The temperature is 155℃, the hot-pressing pressure is 8MPa, the preheating time is 300s, the hot-pressing time is 300s, and the cooling time is 700s. The thickness of the prepared polypropylene composite material is 1.58mm.

[0659] Example B13

[0660] This embodiment illustrates the preparation of the polypropylene composition, three-layer co-extruded polypropylene sheet, polypropylene fabric, and polypropylene composite material provided by the present invention.

[0661] (1) Preparation of polypropylene composition A:

[0662] The preparation process is the same as step (1) of Example B1.

[0663] (2) Preparation of polypropylene composition B:

[0664] The preparation process is the same as step (2) of Example B1.

[0665] (3) Preparation of three-layer co-extruded polypropylene sheets:

[0666] The preparation process is the same as step (3) of Example B1.

[0667] (4) Preparation of polypropylene composite materials:

[0668] Instead of preparing polypropylene fabric, the three-layer co-extruded polypropylene sheet obtained in step (3) was used to replace the polypropylene fabric obtained in step (4) of Example B1, and the sheets were sequentially stacked and hot-pressed according to step (5) of Example B1. The thickness of the prepared polypropylene composite material was 1.51 mm.

[0669] Example B14

[0670] This embodiment illustrates the preparation of the polypropylene composition, five-layer co-extruded polypropylene composite sheet, polypropylene fabric, and polypropylene composite material provided by the present invention.

[0671] (1) Preparation of polypropylene composition A:

[0672] Component a is a homopolymer polypropylene self-produced by the Beijing Research Institute of Chemical Industry, Sinopec, with a melting point of 160℃, a melt flow rate (melt mass flow rate) of 3.2 g / 10 min, and an isotacticity of 97%. Component b is a polypropylene impact copolymer self-produced by the Beijing Research Institute of Chemical Industry, Sinopec (with a cantilever beam impact strength of 23 KJ / m under 23℃ testing conditions). 2 The ethylene content is 11% wt, the melt flow rate is 2.0 g / 10 min, and the melting point is 155℃.

[0673] The components obtained above are weighed and mixed according to the specified proportions, wherein the mass fraction W of component a is... a The mass fraction W of component b is 80 parts by weight. b 20 parts by weight. Add 0.05 parts by weight of β-crystal nucleating agent of grade VP101B. Then, add the mixture to a high-speed mixer and mix thoroughly. Next, add the mixed material to the feeder of a twin-screw extruder manufactured by W&P. The material enters the twin screws through the feeder. During processing, the screw temperature is maintained between 200-230℃. After being melted and mixed evenly by the screws, extruded, granulated, and dried, polypropylene composition granules are obtained. The melt flow rate is measured to be 4.6 g / 10 min; the melting point of polypropylene composition A is 157℃.

[0674] (2) Preparation of polypropylene composition C:

[0675] Component α is a polyolefin elastomer of grade 6102, purchased from ExxonMobil, and is an ethylene-propylene copolymer; the ethylene content is 16% wt (melt flow rate at 190℃ and 2.16 kg load is 1.4 g / 10 min); component β is a random copolymer polypropylene of grade 6102, manufactured by Sinopec Beijing Research Institute of Chemical Industry, and is an ethylene-propylene-butene terpolymer with a molecular weight distribution Mw / Mn of 7.3, a melting point of 140℃, and a melt flow rate of 6.6 g / 10 min; component γ is a homopolymer polypropylene of grade 6102, manufactured by Sinopec Beijing Research Institute of Chemical Industry, with a melt flow rate of 3.2 g / 10 min, a melting point of 160℃, and an isotacticity of 97%. The mass fraction W of component α is... α The weight percentage of component β is 45 parts by weight, W. β For 45 parts by weight, W γ The mixture is 10 parts by weight. Then, the mixture is added to a high-speed mixer and mixed evenly. The mixed material is then added to the feeder of a twin-screw extruder manufactured by W&P. The material enters the twin screw through the feeder. During the processing, the screw temperature is maintained between 200-230℃. After being melted and mixed evenly by the screw, extruded, granulated and dried, polypropylene composition C granules are obtained. The melt mass flow rate is tested to be 6.9 g / 10 min, and the melting point of polypropylene composition C is 145℃.

[0676] (3) Preparation of polypropylene composition B:

[0677] Component x is a random copolymer polypropylene produced by the Beijing Research Institute of Chemical Industry of Sinopec. It is an ethylene-propylene-butene terpolymer with a molecular weight distribution of Mw / Mn of 7.3, a melting point of 140℃, and a melt flow rate of 6.6 g / 10 min. Component y is a polyolefin elastomer of grade 6102 purchased from Exxon. It is an ethylene-propylene copolymer with an ethylene content of 16% wt (melt flow rate of 1.4 g / 10 min at 190℃ and 2.16 kg load).

[0678] The components obtained above are weighed and mixed according to the specified proportions, wherein the mass fraction W of component x is... x The mass fraction W of component y is 85 parts by weight. y The weight is 15 parts, and the other steps are the same as in step (1). Finally, polypropylene composition B granules are obtained. The melt mass flow rate is tested to be 5.2 g / 10 min. The melting point of polypropylene composition B is 138℃.

[0679] (4) Preparation of five-layer co-extruded polypropylene composite sheet:

[0680] The polypropylene composition A, polypropylene composition C, and polymer B granules obtained in steps (1) and (2) above are dried. Then, polypropylene composition A is added to the core extruder of a multi-layer extrusion calender, polypropylene composition C is added to the intermediate extruder of a multi-layer extrusion casting machine, and polypropylene composition B is added to the upper and lower surface extruders of the multi-layer extrusion casting machine. After the granules are co-extruded through the extruder die, they pass sequentially through calendering rollers and traction rollers, and then undergo solid-phase stretching, edge trimming, and winding to obtain the sheet material. The extrusion casting temperature is 230°C, and the calendering roller temperature is 60°C. The solid-phase stretching process is carried out at a temperature of 138°C, a stretching rate of 2 m / min, and a stretching ratio of 7 times.

[0681] After stretching and winding, a polypropylene composite sheet (composite film) is formed, which consists of an upper surface layer (film layer B), an intermediate layer (film layer C), a core layer (film layer A), an intermediate layer (film layer C), and a lower surface layer (film layer B). The thickness of the polypropylene composite sheet is 80 μm, where the thickness of film layer A accounts for 80% of the total sheet thickness, the thickness of film layer C accounts for 10% of the total sheet thickness, and the thickness of film layer B accounts for 10% of the total sheet thickness.

[0682] (5) Preparation of polypropylene fabric:

[0683] The five-layer co-extruded polypropylene composite sheet obtained in step (4) above is cut with a high-speed slitting machine with multiple blades to obtain an oriented polypropylene flat strip with a width of 3mm; the oriented flat strip is woven with a commercial weaving machine according to the designed fabric structure to obtain a plain weave polypropylene fabric.

[0684] (6) Preparation of polypropylene composite materials:

[0685] The polypropylene fabrics obtained in step (5) are sequentially stacked and hot-pressed to form a laminated polypropylene composite sheet. The laminated polypropylene composite sheet includes 24 layers of polypropylene fabric, with the polypropylene fabrics placed at a 90° angle between the warp and weft directions. The hot-pressing conditions are as follows: temperature 153℃, hot-pressing pressure 5MPa, preheating time 300s, hot-pressing time 180s, and cooling time 600s.

[0686] The thickness of the prepared polypropylene composite material is 1.82 mm.

[0687] Example B15

[0688] This embodiment illustrates the preparation of the polypropylene composition, five-layer co-extruded polypropylene composite sheet, polypropylene fabric, and polypropylene composite material provided by the present invention.

[0689] (1) Preparation of polypropylene composition A:

[0690] Component a is a homopolymer polypropylene self-produced by the Beijing Research Institute of Chemical Industry of Sinopec, with a melting point of 165℃, a melt flow rate of 8.1 g / 10 min, and an isotacticity of 97%; component b is a polypropylene impact copolymer self-produced by the Beijing Research Institute of Chemical Industry of Sinopec, with a cantilever beam impact strength of 25 KJ / m under a test condition of 23℃. 2 The ethylene content is 8% wt, the melt flow rate is 3.2 g / 10 min, and the melting point is 155 °C. The components obtained above are weighed and mixed according to the specified proportions, wherein component a has a mass fraction W. a The mass fraction W of component b is 70 parts by weight. b The sample consisted of 30 parts by weight. 0.05 parts by weight of β-crystal nucleating agent (VP101B) was added. The mixture was then added to a high-speed mixer and mixed thoroughly. The mixed material was then fed into the feeder of a twin-screw extruder manufactured by W&P. The material entered the twin screws via the feeder. During processing, the screw temperature was maintained between 200-230°C. After being melted and mixed evenly by the screws, extruded, granulated, and dried, polypropylene composition granules were obtained. The melt flow rate was measured to be 7.3 g / 10 min. The melting point of polypropylene composition A was 161°C.

[0691] (2) Preparation of polypropylene composition C:

[0692] Component α is a polyolefin elastomer produced by Sinopec Beijing Research Institute of Chemical Industry, which is an ethylene-propylene copolymer with an ethylene content of 15% wt and a melting point of 105℃ (melt flow rate of 9 g / 10 min at 190℃ and 2.16 kg load); component β is a random copolymer polypropylene produced by Sinopec Beijing Research Institute of Chemical Industry, which is an ethylene-propylene-butene terpolymer with a molecular weight distribution Mw / Mn of 7.6, a melting point of 134℃, and a melt flow rate of 5.2 g / 10 min; component γ is a homopolymer polypropylene produced by Sinopec Beijing Research Institute of Chemical Industry, with a melting point of 165℃, a melt flow rate of 8.1 g / 10 min, and an isotacticity of 97%. The mass fraction W of component α is... α The weight percentage of component β is 55 parts by weight, W. β For 40 parts by weight, W γ Five parts by weight were used to mix the mixture in a high-speed mixer until homogeneous. The mixed material was then fed into the feeder of a twin-screw extruder manufactured by W&P. The material entered the twin screws through the feeder. During the processing, the screw temperature was maintained between 200-230°C. After being melted and mixed evenly by the screws, extruded, granulated, and dried, polypropylene composition C granules were obtained. The melt flow rate was tested to be 7.8 g / 10 min, and the melting point of polypropylene composition C was 156°C.

[0693] (3) Preparation of polypropylene composition B:

[0694] Component x is a random copolymer polypropylene, self-produced by the Beijing Research Institute of Chemical Industry of Sinopec, which is an ethylene-propylene-butene terpolymer with a molecular weight distribution Mw / Mn of 7.6, a melting point of 134℃, and a melt flow rate of 5.2 g / 10 min. Component y and α are polyolefin elastomers, also self-produced by the Beijing Research Institute of Chemical Industry of Sinopec, which are ethylene-propylene copolymers with an ethylene content of 15% wt and a melting point of 105℃ (melt flow rate of 9 g / 10 min at 190℃ and 2.16 kg load). The components prepared above were weighed and mixed according to the specified proportions, wherein the mass fraction W of component x is... x The mass fraction W of component y is 80 parts by weight. y The weight is 20 parts, and the other steps are the same as in step (1). Finally, polypropylene composition B granules are obtained. The melt flow rate is 9.6 g / 10 min and the melting point of polypropylene composition B is 130 °C.

[0695] (4) Preparation of five-layer co-extruded polypropylene composite sheet:

[0696] The preparation process is the same as step (4) of Example B14.

[0697] (5) Preparation of polypropylene fabric:

[0698] The preparation process is the same as step (5) of Example B14.

[0699] (6) Preparation of polypropylene composite materials:

[0700] The preparation process is the same as step (6) of Example B14.

[0701] The thickness of the prepared polypropylene composite material is similar to that of Example B14.

[0702] Example B16

[0703] This embodiment illustrates the preparation of the polypropylene composition, five-layer co-extruded polypropylene composite sheet, polypropylene fabric, and polypropylene composite material provided by the present invention.

[0704] (1) Preparation of polypropylene composition A:

[0705] Same as Example B1, wherein component a (Wa) has 90 parts by weight and component b (Wb) has 10 parts by weight. 0.05 parts by weight of β-crystal nucleating agent (VP101B) are added. Polypropylene composition A granules are obtained, and its melt flow rate is measured to be 6.8 g / 10 min. The melting point of polypropylene composition A is 158°C.

[0706] (2) Preparation of polypropylene composition C:

[0707] Same as in Example B1, wherein the mass fraction W of component α α The mass fraction W of component β is 35 parts by weight. β For 55 parts by weight, W γ Ten parts by weight were used to obtain polypropylene composition C granules. The melt flow rate was measured to be 7.3 g / 10 min, and the melting point of polypropylene composition C was 142 °C.

[0708] (3) Preparation of polypropylene composition B:

[0709] Same as in Example B1, wherein the mass fraction W of component x x The mass fraction W of component y is 90 parts by weight. y Ten parts by weight were used to obtain polypropylene composition B granules. The melt flow rate was measured to be 8.7 g / 10 min, and the melting point of polypropylene composition B was 139 °C.

[0710] (4) Preparation of five-layer co-extruded polypropylene composite sheet:

[0711] The preparation process is the same as step (4) of Example B14.

[0712] (5) Preparation of polypropylene fabric:

[0713] The preparation process is the same as step (5) of Example B14.

[0714] (6) Preparation of polypropylene composite materials:

[0715] The preparation process is the same as step (6) of Example B14.

[0716] The thickness of the prepared polypropylene composite material is similar to that of Example B14.

[0717] Example B17

[0718] This embodiment illustrates the preparation of the polypropylene composition, five-layer co-extruded polypropylene composite sheet, polypropylene fabric, and polypropylene composite material provided by the present invention.

[0719] (1) Preparation of polypropylene composition A:

[0720] The preparation process is the same as step (1) of Example B14.

[0721] (2) Preparation of polypropylene composition C:

[0722] The preparation process is the same as step (2) of Example B14.

[0723] (3) Preparation of polypropylene composition B:

[0724] The preparation process is the same as step (3) of Example B14.

[0725] (4) Preparation of five-layer co-extruded polypropylene composite sheet:

[0726] The main steps are the same as in Example B14, wherein the thickness of film layer A accounts for 90% of the total thickness of the sheet, the thickness of film C accounts for 5% of the total thickness of the sheet, and the thickness of film B accounts for 5% of the total thickness of the sheet.

[0727] (5) Preparation of polypropylene fabric:

[0728] The preparation process is the same as step (5) of Example B14.

[0729] (6) Preparation of polypropylene composite materials:

[0730] The preparation process is the same as step (6) of Example B14.

[0731] The thickness of the prepared polypropylene composite material is similar to that of Example B14.

[0732] Example B18

[0733] This embodiment illustrates the preparation of the polypropylene composition, five-layer co-extruded polypropylene composite sheet, polypropylene fabric, and polypropylene composite material provided by the present invention.

[0734] (1) Preparation of polypropylene composition A:

[0735] The preparation process is the same as step (1) of Example B14.

[0736] (2) Preparation of polypropylene composition C:

[0737] The preparation process is the same as step (2) of Example B14.

[0738] (3) Preparation of polypropylene composition B:

[0739] The preparation process is the same as step (3) of Example B14.

[0740] (4) Preparation of five-layer co-extruded polypropylene composite sheet:

[0741] The main steps are the same as in Example B14. The thickness of the polypropylene composite sheet is 80 μm, wherein the thickness of film layer A accounts for 70% of the total sheet thickness, the thickness of film C accounts for 15% of the total sheet thickness, and the thickness of film B accounts for 15% of the total sheet thickness.

[0742] (5) Preparation of polypropylene fabric:

[0743] The preparation process is the same as step (5) of Example B14.

[0744] (6) Preparation of polypropylene composite materials:

[0745] The preparation process is the same as step (6) of Example B14.

[0746] The thickness of the prepared polypropylene composite material is similar to that of Example B14.

[0747] Example B19

[0748] This embodiment illustrates the preparation of the polypropylene composition, five-layer co-extruded polypropylene composite sheet, polypropylene fabric, and polypropylene composite material provided by the present invention.

[0749] (1) Preparation of polypropylene composition A:

[0750] The preparation process is the same as step (1) of Example B14.

[0751] (2) Preparation of polypropylene composition C:

[0752] The preparation process is the same as step (2) of Example B14.

[0753] (3) Preparation of polypropylene composition B:

[0754] The preparation process is the same as step (3) of Example B14.

[0755] (4) Preparation of five-layer co-extruded polypropylene composite sheet:

[0756] The preparation process is the same as step (4) of Example B14.

[0757] (5) Preparation of polypropylene fabric:

[0758] The main steps are the same as step (5) in Example B14. The oriented flat strip is woven into a satin polypropylene fabric by using a commercial loom according to the designed fabric structure.

[0759] (6) Preparation of polypropylene composite materials:

[0760] The preparation process is the same as step (6) of Example B14.

[0761] The thickness of the prepared polypropylene composite material is similar to that of Example B14.

[0762] Example B20

[0763] This embodiment illustrates the preparation of the polypropylene composition, five-layer co-extruded polypropylene composite sheet, polypropylene fabric, and polypropylene composite material provided by the present invention.

[0764] (1) Preparation of polypropylene composition A:

[0765] The preparation process is the same as step (1) of Example B14.

[0766] (2) Preparation of polypropylene composition C:

[0767] The preparation process is the same as step (2) of Example B14.

[0768] (3) Preparation of polypropylene composition B:

[0769] The preparation process is the same as step (3) of Example B14.

[0770] (4) Preparation of five-layer co-extruded polypropylene composite sheet:

[0771] The main preparation process is the same as step (4) of Example B14. The sheet stretching ratio is 10 times.

[0772] (5) Preparation of polypropylene fabric:

[0773] The preparation process is the same as step (5) of Example B14.

[0774] (6) Preparation of polypropylene composite materials:

[0775] The preparation process is the same as step (6) of Example B14.

[0776] The thickness of the prepared polypropylene composite material is similar to that of Example B14.

[0777] Example B21

[0778] This embodiment illustrates the preparation of the polypropylene composition, five-layer co-extruded polypropylene composite sheet, polypropylene fabric, and polypropylene composite material provided by the present invention.

[0779] (1) Preparation of polypropylene composition A:

[0780] The preparation process is the same as step (1) of Example B14.

[0781] (2) Preparation of polypropylene composition C:

[0782] The preparation process is the same as step (2) of Example B14.

[0783] (3) Preparation of polypropylene composition B:

[0784] The preparation process is the same as step (3) of Example B14.

[0785] (4) Preparation of five-layer co-extruded polypropylene composite sheet:

[0786] The preparation process is the same as step (4) of Example B14.

[0787] (5) Preparation of polypropylene fabric:

[0788] The preparation process is the same as step (5) of Example B14.

[0789] (6) Preparation of polypropylene composite materials:

[0790] The main preparation process is the same as step (6) of Example B14. The polypropylene fabric is placed at a 45° angle between the warp and weft directions.

[0791] The thickness of the prepared polypropylene composite material is similar to that of Example B14.

[0792] Example B22

[0793] This embodiment illustrates the preparation of the polypropylene composition, five-layer co-extruded polypropylene composite sheet, polypropylene fabric, and polypropylene composite material provided by the present invention.

[0794] (1) Preparation of polypropylene composition A:

[0795] The preparation process is the same as step (1) of Example B14.

[0796] (2) Preparation of polypropylene composition C:

[0797] The preparation process is the same as step (2) of Example B14.

[0798] (3) Preparation of polypropylene composition B:

[0799] The preparation process is the same as step (3) of Example B14.

[0800] (4) Preparation of five-layer co-extruded polypropylene composite sheet:

[0801] The preparation process is the same as step (4) of Example B14.

[0802] (5) Preparation of polypropylene fabric:

[0803] The preparation process is the same as step (5) of Example B14.

[0804] (6) Preparation of polypropylene composite materials:

[0805] The main preparation process is the same as step (6) of Example B14. The polypropylene fabric is placed with the warp direction at 0° to the warp direction.

[0806] The thickness of the prepared polypropylene composite material is similar to that of Example B14.

[0807] Example B23

[0808] This embodiment illustrates the preparation of the polypropylene composition, five-layer co-extruded polypropylene composite sheet, polypropylene fabric, and polypropylene composite material provided by the present invention.

[0809] (1) Preparation of polypropylene composition A:

[0810] The preparation process is the same as step (1) of Example B14.

[0811] (2) Preparation of polypropylene composition C:

[0812] The preparation process is the same as step (2) of Example B14.

[0813] (3) Preparation of polypropylene composition B:

[0814] The preparation process is the same as step (3) of Example B14.

[0815] (4) Preparation of five-layer co-extruded polypropylene composite sheet:

[0816] The preparation process is the same as step (4) of Example B14.

[0817] (5) Preparation of polypropylene fabric:

[0818] The preparation process is the same as step (5) of Example B14.

[0819] (6) Preparation of polypropylene composite materials:

[0820] The main preparation process is the same as step (6) of Example B14. The laminated polypropylene composite sheet includes two layers of polypropylene fabric. The hot-pressing conditions used are: temperature 145℃, hot-pressing pressure 2MPa, preheating time 150s, hot-pressing time 60s, and cooling time 300s. The thickness of the prepared polypropylene composite material is 136μm.

[0821] Example B24

[0822] This embodiment illustrates the preparation of the polypropylene composition, five-layer co-extruded polypropylene composite sheet, polypropylene fabric, and polypropylene composite material provided by the present invention.

[0823] (1) Preparation of polypropylene composition A:

[0824] The preparation process is the same as step (1) of Example B14.

[0825] (2) Preparation of polypropylene composition C:

[0826] The preparation process is the same as step (2) of Example B14.

[0827] (3) Preparation of polypropylene composition B:

[0828] The preparation process is the same as step (3) of Example B14.

[0829] (4) Preparation of five-layer co-extruded polypropylene composite sheet:

[0830] The preparation process is the same as step (4) of Example B14.

[0831] (5) Preparation of polypropylene fabric:

[0832] The preparation process is the same as step (5) of Example B14.

[0833] (6) Preparation of polypropylene composite materials:

[0834] The main preparation process is the same as step (6) of Example B14. The laminated polypropylene composite sheet includes 100 layers of polypropylene fabric. The hot-pressing conditions used are: 159°C, hot-pressing pressure of 10MPa, preheating time of 420s, hot-pressing time of 300s, and cooling time of 700s. The thickness of the prepared polypropylene composite material is 7.45mm.

[0835] Example B25

[0836] This embodiment illustrates the preparation of the polypropylene composition, five-layer co-extruded polypropylene composite sheet, polypropylene fabric, and polypropylene composite material provided by the present invention.

[0837] (1) Preparation of polypropylene composition A:

[0838] The preparation process is the same as step (1) of Example B14.

[0839] (2) Preparation of polypropylene composition C:

[0840] The preparation process is the same as step (2) of Example B14.

[0841] (3) Preparation of polypropylene composition B:

[0842] The preparation process is the same as step (3) of Example B14.

[0843] (4) Preparation of five-layer co-extruded polypropylene composite sheet:

[0844] The preparation process is the same as step (4) of Example B14.

[0845] (5) Preparation of polypropylene fabric:

[0846] The preparation process is the same as step (5) of Example B14.

[0847] (6) Preparation of polypropylene composite materials:

[0848] The main preparation process is the same as step (6) of Example B14. The temperature is 155℃, the hot pressing pressure is 8MPa, the preheating time is 300s, the hot pressing time is 300s, and the cooling time is 700s. The thickness of the prepared polypropylene composite material is 1.61mm.

[0849] Example B26

[0850] This embodiment illustrates the preparation of the polypropylene composition, five-layer co-extruded polypropylene sheet, polypropylene fabric, and polypropylene composite material provided by the present invention.

[0851] (1) Preparation of polypropylene composition A:

[0852] The preparation process is the same as step (1) of Example B14.

[0853] (2) Preparation of polypropylene composition C:

[0854] The preparation process is the same as step (2) of Example B14.

[0855] (3) Preparation of polypropylene composition B:

[0856] The preparation process is the same as step (3) of Example B14.

[0857] (4) Preparation of five-layer co-extruded polypropylene composite sheet:

[0858] The preparation process is the same as step (4) of Example B14.

[0859] (5) Preparation of polypropylene composite materials:

[0860] The main preparation process is the same as step (6) of Example B14. The difference is that the polypropylene fabric is not prepared. Instead, the five-layer co-extruded polypropylene sheet obtained in step (4) above is used to replace the polypropylene fabric in Example B14 and is then stacked and hot-pressed.

[0861] The thickness of the prepared polypropylene composite material is similar to that of Example B14.

[0862] Example B27

[0863] Five-layer co-extruded polypropylene sheets were prepared according to the method of Example B14, except that component A was selected as follows: component a was homopolymer polypropylene self-made by Sinopec Beijing Chemical Research Institute, with a melting point of 155°C, a melt flow rate of 14.3 g / 10 min, and an isotacticity of 96%.

[0864] The thickness of the prepared polypropylene composite material is similar to that of Example B14.

[0865] Example B28

[0866] Five-layer co-extruded polypropylene sheets were prepared according to the method of Example B14, except that component B was selected as follows: component x was random copolymer polypropylene self-made by Sinopec Beijing Chemical Research Institute, which was an ethylene-propylene-butene terpolymer with a molecular weight distribution Mw / Mn of 10.5, a melting point of 130°C, and a melt flow rate of 9.2 g / 10 min.

[0867] The thickness of the prepared polypropylene composite material is similar to that of Example B14.

[0868] Comparative Example B1

[0869] Three-layer co-extruded polypropylene sheets were prepared according to the method of Example B1. However, only polypropylene composition A was used for extrusion casting into a single-layer film with a film thickness of 80 μm. Polypropylene fabrics and polypropylene composites were also prepared according to the method of Example B1.

[0870] The thickness of the prepared polypropylene composite material is similar to that of Example B1.

[0871] Comparative Example B2

[0872] Three-layer co-extruded polypropylene sheets were prepared according to the method of Example B1. However, only polypropylene composition B was used for extrusion casting into a single-layer film with a thickness of 80 μm. Polypropylene fabrics and polypropylene composites were also prepared according to the method of Example B1.

[0873] The thickness of the prepared polypropylene composite material is similar to that of Example B1.

[0874] Comparative Example B3

[0875] Three-layer co-extruded polypropylene sheets were prepared according to the method of Example B1. However, polypropylene composition A contained only component b. Polypropylene fabrics and polypropylene composites were also prepared according to the method of Example B1.

[0876] The thickness of the prepared polypropylene composite material is similar to that of Example B1.

[0877] Comparative Example B4

[0878] Three-layer co-extruded polypropylene sheets were prepared according to the method of Example B1. However, polypropylene composition B contained only component y. Polypropylene fabrics and polypropylene composites were also prepared according to the method of Example B1.

[0879] The thickness of the prepared polypropylene composite material is similar to that of Example B1.

[0880] Comparative Example B5

[0881] A three-layer co-extruded polypropylene sheet was prepared according to the method of Example B1. The only difference was that the thickness of film layer A accounted for 95% of the total sheet thickness. Polypropylene fabrics and polypropylene composites were also prepared according to the method of Example B1.

[0882] The thickness of the prepared polypropylene composite material is similar to that of Example B1.

[0883] Comparative Example B6

[0884] A three-layer co-extruded polypropylene sheet was prepared according to the method of Example B1. The only difference was that the thickness of the film layer A accounted for 50% of the total sheet thickness. Polypropylene fabrics and polypropylene composites were also prepared according to the method of Example B1.

[0885] The thickness of the prepared polypropylene composite material is similar to that of Example B1.

[0886] Comparative Example B7

[0887] A five-layer co-extruded polypropylene composite sheet was prepared according to the method of Example B14. However, only polypropylene composition A was used for extrusion casting into a single-layer film with a thickness of 80 μm. Polypropylene fabrics and polypropylene composite materials were prepared according to the method of Example B1.

[0888] The thickness of the prepared polypropylene composite material is similar to that of Example B14.

[0889] Comparative Example B8

[0890] A five-layer co-extruded polypropylene composite sheet was prepared according to the method of Example B14. However, only polypropylene composition C was used for extrusion casting into a single-layer film with a thickness of 80 μm. Polypropylene fabrics and polypropylene composite materials were prepared according to the method of Example B1.

[0891] The thickness of the prepared polypropylene composite material is similar to that of Example B14.

[0892] Comparative Example B9

[0893] A five-layer co-extruded polypropylene composite sheet was prepared according to the method of Example B14. However, only polypropylene composition B was used for extrusion casting into a single-layer film with a thickness of 80 μm. Polypropylene fabrics and polypropylene composite materials were prepared according to the method of Example B1.

[0894] The thickness of the prepared polypropylene composite material is similar to that of Example B14.

[0895] Comparative Example B10

[0896] A five-layer co-extruded polypropylene composite sheet was prepared according to the method of Example B14. However, polypropylene composition A contained only component b. Polypropylene fabrics and polypropylene composite materials were prepared according to the method of Example B1.

[0897] The thickness of the prepared polypropylene composite material is similar to that of Example B14.

[0898] Comparative Example B11

[0899] A five-layer co-extruded polypropylene composite sheet was prepared according to the method of Example B14. However, the polypropylene composition B contained only component y. Polypropylene fabrics and polypropylene composite materials were prepared according to the method of Example B1.

[0900] The thickness of the prepared polypropylene composite material is similar to that of Example B14.

[0901] Comparative Example B12

[0902] A five-layer co-extruded polypropylene composite sheet was prepared according to the method of Example B14. The only difference was that the thickness of film layer A accounted for 95% of the total sheet thickness, the thickness of film C accounted for 2.5% of the total sheet thickness, and the thickness of film B accounted for 2.5% of the total sheet thickness. Polypropylene fabrics and polypropylene composite materials were prepared according to the method of Example B1.

[0903] The thickness of the prepared polypropylene composite material is similar to that of Example B14.

[0904] Comparative Example B13

[0905] A five-layer co-extruded polypropylene composite sheet was prepared according to the method of Example B14. The only difference was that the thickness of film layer A accounted for 50% of the total sheet thickness, the thickness of film C accounted for 25% of the total sheet thickness, and the thickness of film B accounted for 25% of the total sheet thickness. Polypropylene fabrics and polypropylene composite materials were prepared according to the method of Example B1.

[0906] The thickness of the prepared polypropylene composite material is similar to that of Example B14.

[0907] Experimental Example

[0908] The polypropylene composite materials obtained in the above examples and comparative examples were tested according to the following methods, and the test results are shown in Tables 2 and 3.

[0909] (1) Tensile strength: Samples were prepared and tested according to the methods specified in GB / T1040.1-2018;

[0910] (2) Interlayer peel strength: Samples were prepared and measured in accordance with the method specified in QB / T2358-98.

[0911] (3) Drop hammer impact strength: The strength was determined according to the method specified in GB / T14153-1993. The thicknesses of the polypropylene composite materials obtained in Examples B1-9 and Comparative Examples B1-6 were all similar, approximately 1.6 mm, and within the range of 1.6 mm ± 1 mm. The thicknesses of the polypropylene composite materials obtained in Examples B14-22, Example B26, and Comparative Examples B7-13 were all similar, approximately 1.8 mm, and within the range of 1.8 mm ± 1 mm.

[0912] Table 2

[0913]

[0914] The results from the examples in Table 3 show that the polypropylene composite material prepared according to the present invention has both excellent tensile and impact resistance, as well as good interlaminar peel strength at relatively low hot-pressing temperatures. The longitudinal (MD) tensile strength of the polypropylene composite sheet of the present invention is ≥150 MPa, and the interlaminar peel strength is ≥1 N / mm. When the polypropylene composite material is made of 24 layers of polypropylene fabric hot-pressed together with a thickness of approximately 1.6 mm, the drop hammer impact strength is ≥228 J.

[0915] As can be seen from the preferred embodiments B1-3, the longitudinal (MD) tensile strength of the polypropylene composite material prepared by the present invention is ≥170MPa, the interlaminar peel strength is ≥1.2N / mm, and the drop hammer impact strength is ≥240J when the polypropylene composite material is made of 24 layers of polypropylene fabric hot-pressed together and the thickness is about 1.6mm.

[0916] As can be seen from Comparative Examples B1-6, using only a single-layer sheet structure or using interlayer ratios outside the scope of the examples will lead to a decrease in the performance of the laminated polypropylene sheets or fabrics, resulting in a significant decrease in the tensile strength, impact properties, or interlayer peel strength of the obtained polypropylene composite material.

[0917] Table 3

[0918]

[0919]

[0920] The results from the examples in Table 3 show that the polypropylene composite material prepared according to the present invention has both excellent tensile and impact resistance, as well as good interlaminar peel strength at relatively low hot-pressing temperatures. When the polypropylene composite sheet has a BCACB layer structure, the longitudinal (MD) tensile strength of the polypropylene composite material of the present invention is ≥150MPa, and the interlaminar peel strength is ≥1.1N / mm; when the polypropylene composite material is obtained by hot-pressing 24 layers of polypropylene fabric with a thickness of about 1.8mm, the drop hammer impact strength is ≥240J.

[0921] As can be seen from preferred embodiments B14-16, the polypropylene composite material prepared by the present invention has a longitudinal (MD) tensile strength ≥170MPa and an interlaminar peel strength ≥1.3N / mm; the polypropylene composite material is obtained by hot pressing 24 layers of polypropylene fabric, and when the thickness is about 1.8mm, the drop hammer impact strength is ≥250J. As can be seen from comparative examples B7-13, using only a single-layer film structure or using a film layer ratio outside the scope of the embodiments will lead to a decrease in the performance of the laminated polypropylene sheet or fabric, resulting in a significant decrease in the tensile strength, impact performance, or interlaminar peel strength of the obtained polypropylene composite material.

[0922] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

[0923] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

Claims

1. A polypropylene composite material comprising a plurality of sequentially stacked polypropylene sheet unit groups; each polypropylene sheet unit group comprising at least one identical or different polypropylene sheet unit, each polypropylene sheet unit comprising a core layer A i and located in core layer A i Outer B on both sides i B' i The structure is B i A i B' i The structure of the polypropylene composite material, from bottom to top, is group n...group i...group 2, group 1, group 2...group i...group n, and the total number of polypropylene sheet unit groups is 2n-1; i and n are both integers not less than 2, and i≤n; in, Core layer A in a polypropylene sheet unit i Composition A containing polypropylene i Outer layer B i With outer layer B' i Whether the composition is the same or different, each composition corresponds to a polypropylene composition B. i Polypropylene composition B' i , The polypropylene composition A i The melting point is greater than that of the polypropylene composition B. i The polypropylene composition B' i The melting point of the outermost layer in the i-th group is greater than the average melting point of the outermost layer in the (i-1)-th group.

2. The polypropylene composite material according to claim 1, characterized in that: Polypropylene Composition A i The melting point of polypropylene composition B i The difference in melting points, polypropylene composition A i The melting point of polypropylene composition B' i The difference in their melting points is greater than or equal to 5°C; and / or, The difference between the average melting point of all outer layers in group i and the average melting point of all outer layers in group i-1, whether the difference is the same or different, is 1-40℃.

3. The polypropylene composite material according to claim 1, characterized in that: Polypropylene Composition A i The melting point of polypropylene composition B i The difference in melting points, polypropylene composition A i The melting point of polypropylene composition B' i The difference in their melting points is greater than or equal to 10°C; and / or, The difference between the average melting point of all outer layers in group i and the average melting point of all outer layers in group i-1, whether the difference is the same or different, is 1-10℃ respectively.

4. The polypropylene composite material according to claim 1, characterized in that: Polypropylene Composition A i The melting point of polypropylene composition B i The difference in melting points, polypropylene composition A i The melting point of polypropylene composition B' i The difference in their melting points is greater than or equal to 20°C; and / or, The difference between the average melting point of all outer layers in group i and the average melting point of all outer layers in group i-1, whether the difference is the same or different, is 1-5℃.

5. The polypropylene composite material according to claim 1, characterized in that: 2≤n≤100; and / or Each polypropylene sheet unit group, independently, comprises 1 to 10 identical or different polypropylene sheet units.

6. The polypropylene composite material according to claim 1, characterized in that: 2≤n≤50; and / or Each polypropylene sheet unit group, independently, comprises 1 to 5 identical or different polypropylene sheet units.

7. The polypropylene composite material according to any one of claims 1-6, characterized in that: The polypropylene sheet unit also includes an intermediate layer C. i C' i The polypropylene sheet unit structure is B. i C i A i C' i B' i Intermediate layer C i With intermediate layer C' i Whether the composition is the same or different, each corresponds to a polypropylene composition C. i Polypropylene composition C' i The polypropylene composition A i The melting point is greater than that of the polypropylene composition C. i The polypropylene composition C' i Its melting point.

8. The polypropylene composite material according to any one of claims 1-6, characterized in that: Based on the total thickness of each polypropylene sheet unit, the core layer A in each polypropylene sheet unit i The thickness accounts for 51%-89% of the total thickness.

9. The polypropylene composite material according to any one of claims 1-6, characterized in that: Based on the total thickness of each polypropylene sheet unit, the core layer A in each polypropylene sheet unit i The thickness accounts for 71%-80% of the total thickness.

10. The polypropylene composite material according to any one of claims 1-6, characterized in that: The polypropylene composition A i Including one or more of homopolymer polypropylene, random copolymer polypropylene, and impact copolymer polypropylene; and / or, The polypropylene composition B i B' i Each includes one or more of homopolymer polypropylene, random copolymer polypropylene, and impact copolymer polypropylene.

11. The polypropylene composite material according to claim 10, characterized in that: The polypropylene composition B i and / or polypropylene composition B' i It also contains thermal bonding enhancer y i .

12. The polypropylene composite material according to claim 7, characterized in that: The polypropylene composition C i C' i Each includes one or more of homopolymer polypropylene, random copolymer polypropylene, and impact copolymer polypropylene.

13. The polypropylene composite material according to claim 12, characterized in that: The polypropylene composition C i and / or polypropylene composition C' i It also contains thermal bonding enhancer z i .

14. The polypropylene composite material according to any one of claims 1-6, characterized in that: Polypropylene Composition A i Including homopolymer polypropylene a i Impact-resistant copolymer polypropylene b i ; and / or, The polypropylene composition B i The polypropylene composition B' i Each includes random copolymer polypropylene x i and thermal bonding enhancer y i .

15. The polypropylene composite material according to claim 14, characterized in that: With the polypropylene composition A i Based on the total weight, the polypropylene composition A i Includes 50-99 wt% homopolymer polypropylene a i 1-50wt% impact-resistant copolymer polypropylene b i ; and / or, With the polypropylene composition B i The polypropylene composition B' i Based on their respective total weights, the polypropylene composition B i The polypropylene composition B' i Each comprises 70-99 wt% random copolymer polypropylene. i 1-30wt% thermal bonding enhancer i .

16. The polypropylene composite material according to claim 14, characterized in that: With the polypropylene composition A i Based on the total weight, the polypropylene composition A i Includes 70-90 wt% homopolymer polypropylene a i 10-30wt% impact-resistant copolymer polypropylene b i ; and / or, With the polypropylene composition B i The polypropylene composition B' i Based on their respective total weights, the polypropylene composition B i The polypropylene composition B' i Each comprises 80-90 wt% random copolymer polypropylene. i 10-20wt% of thermal bonding reinforcing agent i .

17. The polypropylene composite material according to claim 7, characterized in that: The polypropylene composition C i The polypropylene composition C' i Each includes random copolymer polypropylene β i and homopolymer polypropylene γ i and thermal bonding enhancer z i .

18. The polypropylene composite material according to claim 17, characterized in that: With the polypropylene composition C i The polypropylene composition C' i Based on their respective total weights, the polypropylene composition C i The polypropylene composition C' i Each contains 30-60 wt% of thermal bonding reinforcing agent. i 35-55 wt% random copolymer polypropylene β i and 5-15 wt% homopolymer polypropylene γ i .

19. The polypropylene composite material according to claim 17, characterized in that: With the polypropylene composition C i The polypropylene composition C' i Based on their respective total weights, the polypropylene composition C i The polypropylene composition C' i Each contains 35-55 wt% of thermal bonding reinforcement. i 40-55wt% random copolymer polypropylene β i and 5-10 wt% homopolymer polypropylene γ i .

20. The polypropylene composite material according to claim 14, characterized in that: The homopolymer polypropylene a i have: Melting point is 150-170℃; and / or, The melt flow rate at 230℃ and 2.16kg load is 0.5-50g / 10min; and / or, The isotacticity (mm) is not less than 96%.

21. The polypropylene composite material according to claim 20, characterized in that: The homopolymer polypropylene a i have: Melting point is 160-170℃; and / or, The melt flow rate at 230℃ and 2.16kg load is 2.5-18g / 10min.

22. The polypropylene composite material according to claim 17, characterized in that: The homopolymer polypropylene γ i have: Melting point is 150-170℃; and / or, The melt flow rate at 230℃ and 2.16kg load is 0.5-50g / 10min; and / or, The isotacticity (mm) is not less than 96%.

23. The polypropylene composite material according to claim 22, characterized in that: The homopolymer polypropylene γ i have: Melting point is 160-170℃; and / or, The melt flow rate at 230℃ and 2.16kg load is 2.5-18g / 10min.

24. The polypropylene composite material according to claim 17, characterized in that: Polypropylene Composition A i Including homopolymer polypropylene a i Impact-resistant copolymer polypropylene b i And the homopolymer polypropylene a i The homopolymer polypropylene γ i : The difference in melting points is less than 10°C; and / or, The difference in melt flow rate at 230℃ and 2.16kg load is less than 10g / 10min; and / or, The difference in isotacticity (mm) is less than 3%.

25. The polypropylene composite material according to claim 24, characterized in that: The homopolymer polypropylene a i The homopolymer polypropylene γ i : The difference in melting points is less than 3°C; and / or, The difference in melt flow rate at 230℃ and 2.16kg load is less than 3g / 10min; and / or, The difference in isotacticity (mm) is less than 1%.

26. The polypropylene composite material according to claim 24, characterized in that: The homopolymer polypropylene a i The homopolymer polypropylene γ i same.

27. The polypropylene composite material according to claim 14, characterized in that: The impact-resistant copolymer polypropylene b i The melting point is 150-170℃; and / or, The impact-resistant copolymer polypropylene b i The monomers copolymerized with propylene are ethylene or butene; and / or, The impact-resistant copolymer polypropylene b i The melt flow rate at 230℃ and 2.16kg load is 0.5-50g / 10min; and / or, The impact-resistant copolymer polypropylene b i The impact strength of the cantilever beam shall not be less than 20 kJ / m 2 .

28. The polypropylene composite material according to claim 27, characterized in that: The impact-resistant copolymer polypropylene b i The monomer copolymerized with propylene is butene; and / or, The impact-resistant copolymer polypropylene b i The melt flow rate at 230℃ and 2.16kg load is 2.5-18g / 10min.

29. The polypropylene composite material according to claim 14, characterized in that: The random copolymer polypropylene x i have: Melting point is 110-150℃; and / or, The melt flow rate at 230℃ and 2.16kg load is 0.5-50g / 10min; and / or, The molecular weight distribution Mw / Mn is 5-12; and / or, It is a copolymer of propylene with ethylene and / or butene.

30. The polypropylene composite material according to claim 29, characterized in that: The random copolymer polypropylene x i have: Melting point is 120-140℃; and / or, The melt flow rate at 230℃ and 2.16kg load is 3-18 g / 10min; and / or, The molecular weight distribution Mw / Mn is 7-10; and / or, It is an ethylene-propylene-butene terpolymer and / or a propylene-ethylene binary copolymer.

31. The polypropylene composite material according to claim 17, characterized in that: The random copolymer polypropylene β i have: Melting point is 110-150℃; and / or, The melt flow rate at 230℃ and 2.16kg load is 0.5-50g / 10min; and / or, The molecular weight distribution Mw / Mn is 5-12; and / or, It is a copolymer of propylene with ethylene and / or butene.

32. The polypropylene composite material according to claim 31, characterized in that: The random copolymer polypropylene β i have: Melting point is 120-140℃; and / or, The melt flow rate at 230℃ and 2.16kg load is 3-18 g / 10min; and / or, The molecular weight distribution Mw / Mn is 7-10; and / or, It is an ethylene-propylene-butene terpolymer and / or a propylene-ethylene binary copolymer.

33. The polypropylene composite material according to claim 17, characterized in that: The polypropylene composition B i The polypropylene composition B' i Each includes random copolymer polypropylene x i and thermal bonding enhancer y i And the random copolymer polypropylene x i The random copolymer polypropylene β i : The difference in melting points is less than 10°C; and / or, The difference in melt flow rate at 230℃ and 2.16kg load is less than 10g / 10min; and / or The difference in molecular weight distribution is less than 3.

34. The polypropylene composite material according to claim 33, characterized in that: The random copolymer polypropylene x i The random copolymer polypropylene β i : The difference in melting points is less than 3°C; and / or, The difference in melt flow rate at 230℃ and 2.16kg load is less than 3g / 10min; and / or The difference in molecular weight distribution is less than 1.

35. The polypropylene composite material according to claim 34, characterized in that: The random copolymer polypropylene x i The random copolymer polypropylene β i same.

36. The polypropylene composite material according to claim 14, characterized in that: The thermal adhesive reinforcing agent y i have: Melting point or viscous flow temperature is 70-110℃; and / or, The melt flow rate at 190℃ and 2.16kg load is 0.5-50g / 10min; and / or, It is selected from one or more of polyolefin elastomers, ethylene propylene diene monomer (EPDM) rubber, SEBS, SBS, EVA, and petroleum resins.

37. The polypropylene composite material according to claim 36, characterized in that: The thermal adhesive reinforcing agent y i have: The melt flow rate at 190℃ and 2.16kg load is 1-18 g / 10min; and / or, It is a polyolefin elastomer and / or petroleum resin.

38. The polypropylene composite material according to claim 17, characterized in that: The thermal bonding enhancer z i have: Melting point or viscous flow temperature is 70-110℃; and / or, The melt flow rate at 190℃ and 2.16kg load is 0.5-50g / 10min; and / or, It is selected from one or more of polyolefin elastomers, ethylene propylene diene monomer (EPDM) rubber, SEBS, SBS, EVA, and petroleum resins.

39. The polypropylene composite material according to claim 38, characterized in that: The thermal bonding enhancer z i have: The melt flow rate at 190℃ and 2.16kg load is 1-18 g / 10min; and / or, It is a polyolefin elastomer and / or petroleum resin.

40. The polypropylene composite material according to claim 17, characterized in that: The polypropylene composition B i The polypropylene composition B' i Each includes random copolymer polypropylene x i and thermal bonding enhancer y i And the thermal bonding enhancer y i The thermal bonding enhancer z i : The difference between melting point or flow temperature is less than 10°C; and / or, The difference in melt flow rate at 190℃ and 2.16kg load is less than 10g / 10min.

41. The polypropylene composite material according to claim 40, characterized in that: The thermal adhesive reinforcing agent y i The thermal bonding enhancer z i : The difference between melting point or flow temperature is less than 3°C; and / or, The difference in melt flow rate at 190℃ and 2.16kg load is less than 3g / 10min.

42. The polypropylene composite material according to claim 40, characterized in that: The thermal adhesive reinforcing agent y i The thermal bonding enhancer z i same.

43. The polypropylene composite material according to claim 37 or 39, characterized in that: The polyolefin elastomer is a copolymer elastomer of ethylene and propylene and / or α-olefin, wherein the α-olefin is a C4-C12 α-olefin; and / or, The petroleum resin is a C5 and / or C9 hydrogenated petroleum resin with a softening point of 100-150℃.

44. The polypropylene composite material according to claim 43, characterized in that: The α-olefin is 1-butene and / or 1-octene; and / or, The petroleum resin is a cyclopentadiene type resin.

45. The polypropylene composite material according to claim 6, characterized in that: The polypropylene composition A i It also includes β-crystal nucleating agents.

46. ​​The polypropylene composite material according to claim 45, characterized in that: The β-crystal nucleating agent is selected from at least one of polycyclic aromatic hydrocarbons, group IIA binary complexes, aromatic diamides, rare earth compounds, and cyclic dicarboxylate nucleating agents; and / or, With the polypropylene composition A i The total amount is 100 parts by weight, of the polypropylene composition A i The content of the β-crystal nucleating agent mentioned herein is 0.01-0.5 parts by weight.

47. The polypropylene composite material according to any one of claims 1-6, characterized in that: The polypropylene sheet unit is a polypropylene sheet and / or a polypropylene fabric.

48. The polypropylene composite material according to claim 47, characterized in that: The polypropylene sheet is made by comprising a polypropylene composition A i Polypropylene composition B i Polypropylene composition B' i Optional polypropylene composition C i Optional polypropylene composition C' i The components are co-extruded together; and / or, The polypropylene fabric is prepared by the following method: firstly, a polypropylene composition A is prepared... i Polypropylene composition B i Polypropylene composition B' i Optional polypropylene composition C i Optional polypropylene composition C' i Polypropylene sheets are obtained by co-extruding the inner components, and then the polypropylene sheets are woven to obtain the polypropylene fabric.

49. The polypropylene composite material according to claim 47, characterized in that: The polypropylene fabric has a three-dimensional structure of plain weave, twill weave, and / or satin weave.

50. The polypropylene composite material according to claim 47, characterized in that: The polypropylene sheet units are connected by hot-pressing.

51. A method for preparing a polypropylene composite material according to any one of claims 1-50, comprising the step of sequentially stacking 2n-1 polypropylene sheet unit groups in the order of group n...group i...group 2, group 1, group 2...group i...group n, and then performing hot pressing fusion.

52. The preparation method according to claim 51, characterized in that... Includes the following steps: (1) Take polypropylene composition A i Polypropylene composition B i Polypropylene composition B' i Optional polypropylene composition C i Optional polypropylene composition C' i According to B i A i B' i Structure or B i C i A i C' i B' i The structure is co-extruded, cast or calendered, and stretched to obtain polypropylene sheets; (2) Optionally, the polypropylene sheet is slit and then woven to obtain a structure of B. i A i B' i Or the structure is B i C i A i C' i B' i Polypropylene fabric; (3) The polypropylene sheet and / or the polypropylene fabric are sequentially stacked and hot-pressed together, and then cooled and shaped to form a polypropylene composite material.

53. The preparation method according to claim 52, characterized in that: In step (1), polypropylene composition A i The preparation includes melt blending of components including at least one of homopolymer polypropylene, random copolymer polypropylene, and impact copolymer polypropylene; and / or, The polypropylene composition B in step (1) i Polypropylene composition B' i The preparation includes melt blending of components including at least one of homopolymer polypropylene, random copolymer polypropylene, and impact copolymer polypropylene; and / or, The polypropylene composition C in step (1) i Polypropylene composition C' i The preparation includes melt blending of components including at least one of homopolymer polypropylene, random copolymer polypropylene, and impact copolymer polypropylene; and / or, In step (1), the temperatures for co-extrusion molding and casting are independently selected from 190-240°C; and / or, In step (1), the temperature of the calendering roll is 50-70℃; and / or, The stretching temperature in step (1) is 90-165℃; and / or, In step (1), the stretching ratio is 1-15 times.

54. The preparation method according to claim 53, characterized in that: The stretching temperature in step (1) is 90-119℃.

55. The preparation method according to claim 52, characterized in that: In step (3): The hot pressing conditions include: hot pressing temperature of 115-170℃; hot pressing pressure of 2-10MPa; preheating time of 5-600s; and hot pressing time of 1-600s; and / or, The cooling and shaping pressure is 2-8 MPa, and the cooling time is 30-700 seconds; and / or, The adjacent polypropylene fabrics of the stack are placed at an angle of 0-90° between the warp directions; and / or, The adjacent polypropylene sheets in the stack are placed at 0-90° along their respective machine directions.

56. The preparation method according to claim 55, characterized in that: In step (3): The hot pressing conditions include: a hot pressing temperature of 140-159℃ and a hot pressing time of 10-500s.

57. The application of the polypropylene composite material according to any one of claims 1-50 and the polypropylene composite material prepared by the preparation method according to any one of claims 51-56 in the fields of consumer products, automobile manufacturing and military materials.

58. The application of the polypropylene composite material according to any one of claims 1-50 and the polypropylene composite material prepared by the preparation method according to any one of claims 51-56 in the field of sports protection.

59. A polypropylene composite material, said polypropylene composite material being prepared by hot pressing together multilayer polypropylene sheets and / or by hot pressing together a three-dimensional polypropylene fabric woven from said polypropylene sheets; The polypropylene sheet includes layer A and layers B and B' located on both sides of layer A, with a structure of BAB'. Layer A contains polypropylene composition A, and layer B may be the same as or different from layer B', each containing polypropylene composition B and polypropylene composition B' respectively. The melting point of polypropylene composition A is greater than the melting point of polypropylene composition B and polypropylene composition B'. The polypropylene composition A comprises homopolymer polypropylene a and impact copolymer polypropylene b; the polypropylene composition B and the polypropylene composition B' each comprise random copolymer polypropylene x and thermal bonding enhancer y.

60. The polypropylene composite material according to claim 59, characterized in that: The polypropylene sheet further includes layers C and C', and the polypropylene sheet structure is BCAC'B'; layer C and layer C' may be the same or different, and each corresponds to polypropylene composition C and polypropylene composition C'; the melting point of polypropylene composition A is greater than the melting point of polypropylene composition C and polypropylene composition C'; The polypropylene composition C and the polypropylene composition C' each comprise random copolymer polypropylene β, homopolymer polypropylene γ, and thermal bonding enhancer z.

61. The polypropylene composite material according to claim 59, characterized in that: Based on the total weight of the polypropylene composition A, the polypropylene composition A comprises 50-99 wt% homopolymer polypropylene a, 1-50 wt% impact copolymer polypropylene b; and / or, Based on the total weight of the polypropylene composition B and the polypropylene composition B', each of the polypropylene composition B and the polypropylene composition B' comprises 70-99 wt% random copolymer polypropylene x and 1-30 wt% thermal bonding reinforcing agent y.

62. The polypropylene composite material according to claim 59, characterized in that: Based on the total weight of the polypropylene composition A, the polypropylene composition A comprises 70-90 wt% homopolymer polypropylene a, 10-30 wt% impact copolymer polypropylene b; and / or, Based on the total weight of the polypropylene composition B and the polypropylene composition B', each of the polypropylene composition B and the polypropylene composition B' comprises 80-90 wt% random copolymer polypropylene x and 10-20 wt% thermal bonding enhancer y.

63. The polypropylene composite material according to claim 59, characterized in that: Based on the total thickness of the polypropylene sheet, the thickness of layer A accounts for 51%-89% of the total thickness.

64. The polypropylene composite material according to claim 59, characterized in that: Based on the total thickness of the polypropylene sheet, the thickness of layer A accounts for 71%-80% of the total thickness.

65. The polypropylene composite material according to claim 60, characterized in that: Based on the total weight of the polypropylene composition C and the polypropylene composition C', each of the polypropylene composition C and the polypropylene composition C' comprises 30-60 wt% of a heat-bonding reinforcing agent z, 35-55 wt% of random copolymer polypropylene β and 5-15 wt% of homopolymer polypropylene γ.

66. The polypropylene composite material according to claim 60, characterized in that: Based on the total weight of the polypropylene composition C and the polypropylene composition C', each of the polypropylene composition C and the polypropylene composition C' comprises 35-55 wt% of thermal bonding reinforcing agent z, 40-55 wt% of random copolymer polypropylene β, and 5-10 wt% of homopolymer polypropylene γ.

67. The polypropylene composite material according to claim 60, characterized in that: Based on the total thickness of each polypropylene sheet, the thickness of layer A accounts for 51%-89% of the total thickness; the thickness of layers C and C' accounts for 6%-20% of the total thickness; and the thickness of layers B and B' accounts for 5%-30% of the total thickness.

68. The polypropylene composite material according to claim 60, characterized in that: Based on the total thickness of each polypropylene sheet, layer A accounts for 71%-89% of the total thickness; layers C and C' account for 6%-15% of the total thickness; and layers B and B' account for 5%-15% of the total thickness.

69. The polypropylene composite material according to claim 59, characterized in that: The homopolymer polypropylene a has: Melting point is 150-170℃; and / or, The melt flow rate at 230℃ and 2.16kg load is 0.5-50g / 10min; and / or, The isotacticity (mm) is not less than 96%.

70. The polypropylene composite material according to claim 69, characterized in that: The homopolymer polypropylene a has: Melting point is 160-170℃; and / or, The melt flow rate at 230℃ and 2.16kg load is 2.5-18g / 10min.

71. The polypropylene composite material according to claim 60, characterized in that: The homopolymer polypropylene γ has: Melting point is 150-170℃; and / or, The melt flow rate at 230℃ and 2.16kg load is 0.5-50g / 10min; and / or, The isotacticity (mm) is not less than 96%.

72. The polypropylene composite material according to claim 71, characterized in that: The homopolymer polypropylene γ has: Melting point is 160-170℃; and / or, The melt flow rate at 230℃ and 2.16kg load is 2.5-18g / 10min.

73. The polypropylene composite material according to claim 60, characterized in that: The homopolymer polypropylene a, the homopolymer polypropylene γ: The difference in melting points is less than 10°C; and / or, The difference in melt flow rate at 230℃ and 2.16kg load is less than 10g / 10min; and / or, The difference in isotacticity (mm) is less than 3%.

74. The polypropylene composite material according to claim 60, characterized in that: The homopolymer polypropylene a, the homopolymer polypropylene γ: The difference in melting points is less than 3°C; and / or, The difference in melt flow rate at 230℃ and 2.16kg load is less than 3g / 10min; and / or, The difference in isotacticity (mm) is less than 1%.

75. The polypropylene composite material according to claim 60, characterized in that: The homopolymer polypropylene a and the homopolymer polypropylene γ are the same.

76. The polypropylene composite material according to claim 59, characterized in that: The impact-resistant copolymer polypropylene b has a melting point of 150-170℃; and / or, The monomer for the copolymerization of the impact-resistant polypropylene b and propylene is ethylene or butene; and / or, The impact-resistant copolymer polypropylene b has a melt flow rate of 0.5-50 g / 10 min at 230°C and a load of 2.16 kg; and / or, The cantilever beam impact strength of the impact-resistant copolymer polypropylene b is not less than 20 kJ / m. 2 .

77. The polypropylene composite material according to claim 76, characterized in that: The monomer for the copolymerization of the impact-resistant polypropylene b and propylene is butene; and / or, The impact-resistant copolymer polypropylene b has a melt flow rate of 2.5-18 g / 10 min at 230°C and 2.16 kg load.

78. The polypropylene composite material according to claim 59, characterized in that: The random copolymer polypropylene x has: Melting point is 110-150℃; and / or, The melt flow rate at 230℃ and 2.16kg load is 0.5-50g / 10min; and / or, The molecular weight distribution Mw / Mn is 5-12; and / or, It is a copolymer of propylene with ethylene and / or butene.

79. The polypropylene composite material according to claim 78, characterized in that: The random copolymer polypropylene x has: Melting point is 120-140℃; and / or, The melt flow rate at 230℃ and 2.16kg load is 3-18 g / 10min; and / or, The molecular weight distribution Mw / Mn is 7-10; and / or, It is an ethylene-propylene-butene terpolymer and / or a propylene-ethylene binary copolymer.

80. The polypropylene composite material according to claim 60, characterized in that: The random copolymer polypropylene β has: Melting point is 110-150℃; and / or, The melt flow rate at 230℃ and 2.16kg load is 0.5-50g / 10min; and / or, The molecular weight distribution Mw / Mn is 5-12; and / or, It is a copolymer of propylene with ethylene and / or butene.

81. The polypropylene composite material according to claim 80, characterized in that: The random copolymer polypropylene β has: Melting point is 120-140℃; and / or, The melt flow rate at 230℃ and 2.16kg load is 3-18 g / 10min; and / or, The molecular weight distribution Mw / Mn is 7-10; and / or, It is an ethylene-propylene-butene terpolymer and / or a propylene-ethylene binary copolymer.

82. The polypropylene composite material according to claim 60, characterized in that: The random copolymer polypropylene x, the random copolymer polypropylene β: The difference in melting points is less than 10°C; and / or, The difference in melt flow rate at 230℃ and 2.16kg load is less than 10g / 10min; and / or The difference in molecular weight distribution is less than 3.

83. The polypropylene composite material according to claim 60, characterized in that: The random copolymer polypropylene x, the random copolymer polypropylene β: The difference in melting points is less than 3°C; and / or, The difference in melt flow rate at 230℃ and 2.16kg load is less than 3g / 10min; and / or The difference in molecular weight distribution is less than 1.

84. The polypropylene composite material according to claim 60, characterized in that: The random copolymer polypropylene x and the random copolymer polypropylene β are the same.

85. The polypropylene composite material according to claim 59, characterized in that: The thermal bonding enhancer y has the following characteristics: Melting point or viscous flow temperature is 70-110℃; and / or, The melt flow rate at 190℃ and 2.16kg load is 0.5-50g / 10min; and / or, It is selected from one or more of polyolefin elastomers, ethylene propylene diene monomer (EPDM) rubber, SEBS, SBS, EVA, and petroleum resins.

86. The polypropylene composite material according to claim 85, characterized in that: The thermal bonding enhancer y has the following characteristics: The melt flow rate at 190℃ and 2.16kg load is 1-18 g / 10min; and / or, It is a polyolefin elastomer and / or petroleum resin.

87. The polypropylene composite material according to claim 60, characterized in that: The thermal bonding enhancer z has: Melting point or viscous flow temperature is 70-110℃; and / or, The melt flow rate at 190℃ and 2.16kg load is 0.5-50g / 10min; and / or, It is selected from one or more of polyolefin elastomers, ethylene propylene diene monomer (EPDM) rubber, SEBS, SBS, EVA, and petroleum resins.

88. The polypropylene composite material according to claim 87, characterized in that: The thermal bonding enhancer z has: The melt flow rate at 190℃ and 2.16kg load is 1-18 g / 10min; and / or, It is a polyolefin elastomer and / or petroleum resin.

89. The polypropylene composite material according to claim 60, characterized in that: The thermal bonding reinforcing agent y and the thermal bonding reinforcing agent z: The difference between melting point or flow temperature is less than 10°C; and / or, The difference in melt flow rate at 190℃ and 2.16kg load is less than 10g / 10min.

90. The polypropylene composite material according to claim 60, characterized in that: The thermal bonding reinforcing agent y and the thermal bonding reinforcing agent z: The difference between melting point or flow temperature is less than 3°C; and / or, The difference in melt flow rate at 190℃ and 2.16kg load is less than 3g / 10min.

91. The polypropylene composite material according to claim 60, characterized in that: The thermal bonding reinforcing agent y and the thermal bonding reinforcing agent z are the same.

92. The polypropylene composite material according to claim 85 or 87, characterized in that: The polyolefin elastomer is a copolymer elastomer of ethylene and propylene and / or α-olefin, wherein the α-olefin is a C4-C12 α-olefin; and / or, The petroleum resin is a C5 and / or C9 hydrogenated petroleum resin with a softening point of 100-150℃.

93. The polypropylene composite material according to claim 92, characterized in that: The α-olefin is 1-butene and / or 1-octene; and / or, The petroleum resin is a cyclopentadiene type resin.

94. The polypropylene composite material according to claim 59, characterized in that: The polypropylene composition A further includes a β-crystal nucleating agent.

95. The polypropylene composite material according to claim 94, characterized in that: The β-crystal nucleating agent is selected from at least one of polycyclic aromatic hydrocarbons, group IIA binary complexes, aromatic diamides, rare earth compounds, and cyclic dicarboxylate nucleating agents; and / or, Based on a total amount of 100 parts by weight of the polypropylene composition A, the content of the β-crystal nucleating agent in the polypropylene composition A is 0.01-0.5 parts by weight.

96. The polypropylene composite material according to claim 59, characterized in that: The melting point of homopolymer polypropylene a in polypropylene composition A is greater than the melting point of random copolymer polypropylene x in polypropylene compositions B and B'; and / or, The BAB' layered structure of the polypropylene sheet is obtained by co-extrusion of components including polypropylene composition A and polypropylene compositions B and B'.

97. The polypropylene composite material according to claim 96, characterized in that: The temperature difference between the corresponding melting points is greater than or equal to 10℃.

98. The polypropylene composite material according to claim 60, characterized in that: The melting point of homopolymer polypropylene a in polypropylene composition A is greater than the melting point of random copolymer polypropylene x in polypropylene compositions B and B', and random copolymer polypropylene β in polypropylene compositions C and C'; and / or, The BCAC'B' sheet structure of the polypropylene sheet is obtained by co-extrusion of components including polypropylene composition A, polypropylene composition B, B' and polypropylene composition C, C'.

99. The polypropylene composite material according to claim 98, characterized in that: The corresponding melting point temperature difference is greater than or equal to 10℃.

100. The polypropylene composite material according to claim 60, characterized in that, The method for preparing the polypropylene sheet includes co-extruding, casting or calendering, and stretching polypropylene composition A, polypropylene composition B, polypropylene composition B', optional polypropylene composition C, and optional polypropylene composition C' according to the BAB' structure or the BCAC'B' structure to obtain the polypropylene sheet.

101. The polypropylene composite material according to claim 100, characterized in that, The preparation of the polypropylene composition A includes melt blending of components including the homopolymer polypropylene a and the impact copolymer polypropylene b; and / or, The preparation of the polypropylene compositions B and B' includes melt blending of components including the random copolymer polypropylene x and the thermal bonding reinforcing agent y; and / or, The preparation of the polypropylene compositions C and C' includes melt blending of components including the thermal bonding enhancer z, random copolymer polypropylene β, and homopolymer polypropylene γ; and / or, The temperatures for co-extrusion and casting are each independently selected from 200-240°C; and / or, The temperature of the calendering roll is 50-70℃; and / or, The stretching conditions include: a stretching temperature of 90-165℃; and a stretching ratio of 1-15 times.

102. The polypropylene composite material according to claim 101, characterized in that, The stretching temperature is 90-119℃.

103. The polypropylene composite material according to claim 59, characterized in that, The polypropylene fabric is obtained by slitting and weaving the polypropylene sheet; and / or, the polypropylene fabric has a three-dimensional structure of plain weave, twill weave and / or satin weave.

104. The polypropylene composite material according to claim 59, characterized in that, The multilayer polypropylene sheets are stacked from top to bottom at 0-90° angles along their respective machine directions; and / or, The multilayer polypropylene fabric is stacked from top to bottom with warp directions arranged at 0-90° intervals; and / or, The multilayer polypropylene sheet and / or multilayer polypropylene fabric has two or more layers.

105. The polypropylene composite material according to claim 104, characterized in that, The number of layers in the multilayer polypropylene sheet and / or multilayer polypropylene fabric is 2-200.

106. The polypropylene composite material according to claim 104, characterized in that, The number of layers in the multilayer polypropylene sheet and / or multilayer polypropylene fabric is 4-100.

107. A method for preparing a polypropylene composite material according to any one of claims 59-106, the method comprising hot-pressing and fusing the polypropylene sheet and / or the polypropylene fabric together, and then cooling and shaping it to form a polypropylene composite material.

108. The preparation method according to claim 107, characterized in that: The hot-pressing fusion temperature is 115-170℃; and / or, The pressure for hot-pressing fusion is 2-10 MPa; and / or, The preheating time for the hot-pressing fusion is 5-600s, and the hot-pressing time is 1-600s; and / or, The cooling and setting pressure is 2-8 MPa, and the cooling and setting time is 30s-700s; and / or, The polypropylene sheet and / or the polypropylene fabric laminate has at least two layers; and / or The adjacent layers of the polypropylene fabric stack are placed at an angle of 0-90° between the warp directions; and / or, The adjacent layers of the polypropylene sheet stack are placed at 0-90° along their respective machine directions.

109. The preparation method according to claim 108, characterized in that: The hot-pressing fusion temperature is 140-159℃; and / or, The hot-pressing time is 10-500 seconds; and / or, The number of layers in the polypropylene sheet and / or the polypropylene fabric stack is 4-100.

110. The application of the polypropylene composite material according to any one of claims 59-106 and the polypropylene composite material prepared by the preparation method according to any one of claims 107-109 in the fields of automobile manufacturing, military materials and consumer products.

111. The application of the polypropylene composite material according to any one of claims 59-106 and the polypropylene composite material prepared by the preparation method according to any one of claims 107-109 in the field of sports protection.

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