Antistatic polypropylene sheet and fabric thereof, high strength high impact antistatic polypropylene composite and method and use thereof

Abstract

The application relates to the field of polypropylene materials, and discloses an antistatic polypropylene sheet, an antistatic polypropylene fabric, a high-strength high-impact antistatic polypropylene composite material and a preparation method and application thereof. The polypropylene sheet comprises layer A and layers B and B' located on the two sides of the layer A, and the structure is BAB'; the layer A contains homopolymer polypropylene a, impact copolymer polypropylene b and conductive fillers; the layers B and B' are the same or different, and each contains conductive fillers, random copolymer polypropylene x and thermal bonding enhancer y. The antistatic polypropylene composite material is obtained by hot pressing the antistatic polypropylene sheet according to the application, the antistatic polypropylene composite material has excellent mechanical properties, and has good interlayer peeling strength, even at a lower hot pressing temperature and a wider hot pressing temperature range, the interlayer peeling strength of the obtained polypropylene composite material is still high.

Description

Technical Field

[0001] This invention relates to the field of polypropylene materials, and more specifically, to an antistatic polypropylene sheet, an antistatic polypropylene fabric, a high-strength, high-impact antistatic polypropylene composite material, and their preparation methods and applications. Background Technology

[0002] Polypropylene (PP) resin has low density, good heat resistance, and good rigidity, hardness, and weldability, which makes it widely used.

[0003] Self-reinforced polymer composites consist of a matrix and a reinforcing phase composed of different forms of the same polymer. The reinforcing phase is typically highly oriented fibers or ribbons. Most self-reinforced polymer composites are prepared using hot-pressing methods. 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 bonding strength. For example, in US6312638B1, melt-spun oriented polyolefin fibers are hot-pressed, using specific temperature and pressure to partially melt and bond the polyolefin surface layer to prepare a polyolefin board. This preparation method is not only sensitive to the temperature of hot pressing, but also results in significant deorientation of the oriented fibers after hot pressing, leading to a significant decrease in mechanical strength.

[0004] To broaden the hot-pressing window and reduce the hot-pressing pressure, polyolefins with different melting points can be hot-pressed. For example, US8133537B2 describes the hot-pressing of three layers of polyolefin fibers with different melting points to obtain a polyolefin composite material, wherein the melting temperature of the first and second polyolefin layers is lower than that of the core layer. However, the impact strength and interlaminar peel strength of hot-pressed composite materials produced by this method are relatively low.

[0005] Polypropylene molecules are completely nonpolar, have high electrical insulation properties, and a surface resistivity of 10⁻⁶. 16 -10 17 Ω, volume resistivity 10 16 -10 18 The Ω·m value makes it easy for static charge to accumulate. This can cause polypropylene to become statically charged during production or processing due to friction and other reasons, which is difficult to dissipate through conduction. This can lead to problems and safety hazards in the production, processing, storage, transportation and application of polypropylene. Summary of the Invention

[0006] The purpose of this invention is to overcome the technical shortcomings of existing polypropylene composite materials, which are difficult to simultaneously possess a wide processing temperature range, strong mechanical properties, and high interlaminar peel strength. This invention provides antistatic polypropylene sheets, antistatic polypropylene fabrics, high-strength and high-impact antistatic polypropylene composite materials, their preparation methods, and applications. The antistatic polypropylene composite material is obtained from the antistatic polypropylene sheets of this invention through hot pressing, etc. This antistatic polypropylene composite material has excellent mechanical properties and good interlaminar peel strength; even at lower hot-pressing temperatures and within a wide hot-pressing temperature range, the interlaminar peel strength of the obtained polypropylene composite material remains high.

[0007] The first aspect of the present invention is to provide an antistatic polypropylene sheet, comprising layer A and layers B and B' located on both sides of layer A, having a structure of BAB';

[0008] Layer A contains polypropylene composition A and conductive filler. Layer B may be the same as or different from layer B', each containing conductive filler and correspondingly containing polypropylene composition B and polypropylene composition B'. The melting point of polypropylene composition A is greater than the melting points of polypropylene composition B and polypropylene composition B'.

[0009] 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.

[0010] According to the present invention, the content of each component in polypropylene composition A can be selected within a wide range. In a preferred embodiment of the present invention, based on the total weight of polypropylene composition A, polypropylene composition A comprises 50-99 wt% homopolymer polypropylene a and 1-50 wt% impact copolymer polypropylene b; preferably, polypropylene composition A comprises 70-90 wt% homopolymer polypropylene a and 10-30 wt% impact copolymer polypropylene b.

[0011] According to the present invention, the content of conductive filler in layer A can be selected in a wide range. In a preferred embodiment of the present invention, the content of conductive filler in layer A is 0.1-10 parts by weight, preferably 1-3 parts by weight, relative to 100 parts by weight of polypropylene composition A.

[0012] According to the present invention, the content of each component in polypropylene composition B and polypropylene composition B' can be selected within a wide range. In a preferred embodiment of the present invention, based on the total weight of each 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% heat-bonding reinforcing agent y; preferably, each of the polypropylene composition B and the polypropylene composition B' comprises 80-90 wt% random copolymer polypropylene x and 10-20 wt% heat-bonding reinforcing agent y.

[0013] According to the present invention, the content of conductive filler in layer B and layer B' can be selected within a wide range. In a preferred embodiment of the present invention, the content of conductive filler in layer B and layer B' is 0.1-10 parts by weight, preferably 1-3 parts by weight, relative to 100 parts by weight of each of the polypropylene composition B and polypropylene composition B'.

[0014] According to the present invention, the thickness of layer A can be selected within a wide range as a percentage of the total thickness. In a preferred embodiment of the present invention, based on the total thickness of the polypropylene sheet, the thickness of layer A accounts for 51%-89% of the total thickness, preferably 71%-89%, and more preferably 71%-80%. The thicknesses of film layers B and B' on both sides of film layer A can be the same or different, preferably the same.

[0015] The present invention does not limit the thickness of the antistatic polypropylene sheet, and it can be selected within a wide range according to its actual application field. Preferably, the thickness of the antistatic polypropylene sheet can be 10-1000μm, more preferably 30-500μm, and even more preferably 50-300μm.

[0016] According to the present invention, the thickness of film layers A, B, and B' can be controlled by the extruder melt pump during the processing.

[0017] The homopolymer polypropylene a has a wide range of material selection. In a preferred embodiment of the present invention, the homopolymer polypropylene a has the following characteristics:

[0018] Melting point is 150-170℃, preferably 160-170℃; and / or,

[0019] 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, more preferably 2.5-18 g / 10 min; and / or,

[0020] In a preferred embodiment of the present invention, the isotacticity (mm) of the homopolymer polypropylene a is not less than 96%.

[0021] In a more preferred embodiment of the present invention, the homopolymer polypropylene a has a melting point of 160-170°C, a melt flow rate of 0.5-50 g / 10 min at 230°C and a load of 2.16 kg, preferably 1-20 g / 10 min, and more preferably 2.5-18 g / 10 min; the isotacticity (mm) of the homopolymer polypropylene is not less than 96%.

[0022] The high-impact copolymer polypropylene b has a wide range of material selection. In a preferred embodiment of the present invention, the impact copolymer polypropylene b has the following characteristics:

[0023] The impact-resistant copolymer polypropylene b has a melting point of 150-170℃: and / or,

[0024] The monomer for the copolymerization of the impact-resistant copolymer polypropylene b and propylene is ethylene or butene, preferably butene; and / or,

[0025] The impact-resistant copolymer polypropylene b has a melt flow rate of 0.5-50 g / 10 min at 230°C and 2.16 kg load, preferably 1-20 g / 10 min, and more preferably 2.5-18 g / 10 min; and / or,

[0026] The cantilever beam impact strength of the impact-resistant copolymer polypropylene b is not less than 20 KJ / m. 2 (Tested at 23℃).

[0027] In a more preferred embodiment of the present invention, the high-impact copolymer polypropylene b has a melting point of 150-170°C, and the monomer copolymerized with propylene is ethylene or butene, preferably butene; the melt flow rate of the high-impact copolymer polypropylene b 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.

[0028] According to the inventors' research, when the melt flow rate and polymer composition ratio of the antistatic polypropylene composition A are within the above-mentioned preferred range, the high-impact copolymer polypropylene b in the composition can effectively absorb impact energy, meeting the impact performance requirements and giving the sheet good impact performance. Simultaneously, because the macromolecular chain segments in the homopolymer polypropylene a are relatively regular, crystallization occurs during the sheet preparation process, thus the sheet also has good tensile properties.

[0029] The random copolymer polypropylene x has a wide range of material selection. In a preferred embodiment of the present invention, the random copolymer polypropylene x has the following characteristics:

[0030] Melting point is 110-150℃, preferably 120-140℃; and / or,

[0031] 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, more preferably 3-18 g / 10 min; and / or,

[0032] The molecular weight distribution Mw / Mn is 5-12, preferably 7-10; and / or,

[0033] It is a copolymer of propylene and ethylene and / or butene, preferably an ethylene-propylene-butene terpolymer and / or a propylene-ethylene binary copolymer.

[0034] The thermal bonding reinforcing agent y has a wide range of material selection. In a preferred embodiment of the present invention, the thermal bonding reinforcing agent y has the following characteristics:

[0035] Melting point or viscous flow temperature is 70-110℃; and / or,

[0036] The melt flow rate at 190°C and 2.16 kg load is 0.5-50 g / 10 min, preferably 1-20 g / 10 min, more preferably 1-18 g / 10 min; and / or,

[0037] It is selected from one or more of polyolefin elastomers, ethylene propylene diene monomer (EPDM) rubber, SEBS, SBS, EVA, and petroleum resins; preferably, it is a polyolefin elastomer and / or petroleum resin; preferably,

[0038] 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,

[0039] The petroleum resin is a C5 and / or C9 hydrogenated petroleum resin with a softening point of 100-150℃; preferably a cyclopentadiene type resin.

[0040] In another, more preferred embodiment of the present invention, the thermal bonding reinforcing agent y is a petroleum resin, wherein the petroleum resin is a C5 and / or C9 hydrogenated petroleum resin, preferably with a softening point of 100-150°C; more preferably, the petroleum resin is a cyclopentadiene type resin.

[0041] According to the inventor's research, when the antistatic polypropylene composition B i When the melt flow rate and polymer composition ratio are within the preferred range, the low-melting-point random copolymer polypropylene x and the thermal bonding enhancer y in the composition can significantly reduce the hot-pressing temperature and widen the hot-pressing temperature window. Furthermore, the thermal bonding enhancer y provides good adhesion properties for the sheet and can further improve the interlayer peel strength.

[0042] In a preferred embodiment of the present invention, layer A further contains a β-crystal nucleating agent; preferably,

[0043] 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.

[0044] The amount of β-crystal nucleating agent can be selected over a wide range. In a preferred embodiment of the present invention, the content of the β-crystal nucleating agent in layer A is 0.01-0.5 parts by weight relative to 100 parts by weight of polypropylene composition A. 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.

[0045] According to the present invention, the conductive filler can be selected from a wide range. In a preferred embodiment of the present invention, the conductive filler is selected from at least one of carbon black conductive fillers, graphite conductive fillers, carbon nanotube conductive fillers, carbon fiber conductive fillers, conductive metal particles, conductive metal fibers, fillers coated with conductive metals, and metal oxides; preferably,

[0046] The carbon black conductive filler is at least one of acetylene black, superconducting carbon black, and highly conductive carbon black; and / or, the graphite conductive filler is at least one of natural graphite, expandable graphite, expanded graphite, and graphene; and / or, the carbon nanotube conductive filler is at least one of the following carbon nanotubes, either unmodified or surface-modified: single-walled carbon nanotubes and / or multi-walled carbon nanotubes; and / or, the conductive metal in the conductive metal particles and conductive metal fibers is independently at least one of silver, aluminum, copper, iron, nickel, and stainless steel; and / or, the filler coated with conductive metal is selected from at least one of the following materials plated with lead, nickel, or silver: glass beads, glass fibers, and mica sheets; and / or, the metal oxide is at least one of titanium oxide, zinc oxide, tin oxide, indium oxide, and cadmium oxide.

[0047] In a preferred embodiment of the present invention, the melting point of homopolymer polypropylene a in polypropylene composition A is greater than the melting point of random copolymer polypropylene x in polypropylene composition B and polypropylene composition B', preferably with a temperature difference of 10 degrees Celsius between the corresponding melting points. In this preferred embodiment, the inventors of the present invention have surprisingly discovered that the resulting polypropylene sheet, after hot pressing, yields a polypropylene composite material with superior mechanical properties and better interlaminar peel strength. Even at lower hot pressing temperatures and over a wider hot pressing temperature range, the resulting polypropylene composite material exhibits higher interlaminar peel strength.

[0048] More preferably, the difference between the melting point of polypropylene composition A and the melting point of polypropylene composition B, and the difference between the melting point of polypropylene composition A and the melting point of polypropylene composition B', are each greater than or equal to 5°C, preferably greater than or equal to 10°C, and more preferably greater than or equal to 20°C.

[0049] According to the inventor's research, when the antistatic polypropylene composition A i When the melt flow rate, polymer composition ratio, and thickness distribution of film layer A of the antistatic polypropylene combinations 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.

[0050] In a preferred embodiment of the present invention, the BAB' layer structure of the polypropylene sheet is obtained by co-extrusion of layer A raw material containing polypropylene composition A and conductive filler, layer B raw material containing polypropylene composition B and conductive filler, and layer B' raw material containing polypropylene composition B' and conductive filler.

[0051] The second aspect of the present invention is to provide a method for preparing the antistatic polypropylene sheet described in the first aspect, comprising co-extruding, casting or calendering, and stretching a layer A raw material containing a polypropylene composition A and a conductive filler, a layer B raw material containing a polypropylene composition B and a conductive filler, and a layer B' raw material containing a polypropylene composition B' and a conductive filler according to a BAB' structure to obtain the antistatic polypropylene sheet.

[0052] In a preferred embodiment of the present invention, the preparation of the raw material for layer A includes melt blending of components including homopolymer polypropylene a, impact copolymer polypropylene b, and conductive filler. The melt blending conditions and equipment for the antistatic polypropylene composition A adopt the conditions and equipment for melt blending of polyolefins in the prior art. Preferably, the melt temperature is 150-170°C, and the equipment is preferably a twin-screw extruder.

[0053] In a preferred embodiment of the present invention, the preparation of the raw materials for layers B and B' each includes melt blending of components including the random copolymer polypropylene x, the thermal bonding reinforcing agent y, and the conductive filler. The melt blending conditions and equipment for the antistatic polypropylene compositions B and B' adopt the conditions and equipment for melt blending of polyolefins in the prior art. Preferably, the melting temperature is 110-150°C, and the equipment is preferably a twin-screw extruder.

[0054] Preferably, the temperatures for co-extrusion and casting are each independently selected from 200-240°C.

[0055] Preferably, the temperature of the calendering roll is 50-70°C.

[0056] The range of stretching conditions is relatively wide. In a preferred embodiment of the present invention, the stretching conditions include: the stretching method is free stretching, and / or solid-state stretching, and / or multi-stage stretching; the stretching temperature is 90-165℃, preferably 90-140℃, and more preferably 90-119℃; the stretching ratio is 1-20 times, preferably 2-15 times.

[0057] In a preferred embodiment of the present invention, the longitudinal tensile strength of the stretched antistatic polypropylene sheet is greater than or equal to 30 MPa, more preferably 30 MPa-1 GPa; and most preferably 300-800 MPa.

[0058] According to some embodiments of the present invention, antistatic polypropylene composition A, antistatic polypropylene composition B, and B' are co-extruded according to a BAB' 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 antistatic 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 elaborated further here.

[0059] A third aspect of the present invention is to provide an antistatic polypropylene fabric, which is a three-dimensional polypropylene fabric obtained by weaving the antistatic polypropylene sheet described in the first aspect.

[0060] Preferably, the antistatic polypropylene fabric is obtained by slitting and weaving the antistatic polypropylene sheet; and / or, the antistatic polypropylene fabric has a three-dimensional structure of plain weave, twill weave and / or satin weave.

[0061] To facilitate weaving, it is preferable to cut the antistatic polypropylene sheet into polypropylene sheets with a width of 2-5mm, and then weave them to obtain antistatic polypropylene fabric.

[0062] In a more preferred embodiment of the present invention, the antistatic polypropylene fabric is a plain weave, twill weave, satin weave, or three-dimensional antistatic polypropylene fabric obtained by weaving a three-layer co-extruded antistatic polypropylene stretch flat strip, and the three-layer co-extruded polypropylene stretch flat strip includes at least one film layer A formed by a high-melting-point polypropylene composition A and at least one film layer B formed by a low-melting-point polypropylene composition B, wherein the polypropylene composition A includes homopolymer polypropylene a and impact copolymer polypropylene b; the polypropylene composition B includes random copolymer polypropylene x and a thermal bonding reinforcing agent y, and the polymer film layer B is located on both sides of layer A.

[0063] A fourth aspect of the present invention is to provide an antistatic polypropylene composite material, which is prepared by hot pressing together multiple layers of antistatic polypropylene sheets as described in the first aspect and / or antistatic polypropylene fabrics as described in the third aspect.

[0064] Preferably, the antistatic polypropylene composite material is prepared by hot pressing multiple layers of the antistatic polypropylene sheet or the antistatic polypropylene fabric.

[0065] Preferably, the multilayer antistatic polypropylene sheets are stacked from top to bottom at an angle of 0-90° along their respective machine directions.

[0066] Preferably, the multilayer antistatic polypropylene fabric is stacked from top to bottom with the warp direction placed at an angle of 0-90° between the warp directions.

[0067] Preferably, the multilayer antistatic polypropylene sheet and / or multilayer antistatic polypropylene fabric has more than or equal to 2 layers, more preferably 2-200 layers; and most preferably 4-100 layers.

[0068] Preferably, the areal density of the multilayer antistatic polypropylene composite material is greater than or equal to 110 g / m³. 2 More preferably 110g / m 2 -14000g / m 2 The optimal value is 220g / m³. 2 -7000g / m 2 .

[0069] In a preferred embodiment of the present invention, the antistatic polypropylene fabrics in each of the stacked layers may contain the same or different antistatic polypropylene composition A, and each layer may contain antistatic polypropylene fabric A independently selected, preferably the antistatic polypropylene composition A in each layer is the same.

[0070] In a more preferred embodiment of the present invention, the antistatic polypropylene composite material comprises a plurality of sequentially stacked antistatic polypropylene sheet unit groups; each antistatic polypropylene sheet unit group includes at least one identical or different antistatic polypropylene sheet unit, and each antistatic polypropylene sheet unit includes an antistatic core layer A. i and located in core layer A i Antistatic outer layer B on both sides i B' i The structure is B i A i B' iThe structure of the antistatic 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 stacked antistatic polypropylene sheet unit groups is 2n-1; i and n are both integers not less than 2, and i≤n; wherein, the core layer A in the antistatic polypropylene sheet unit... i Composition A containing antistatic polypropylene i Antistatic outer layer B i With antistatic outer layer B' i Whether the composition is the same or different, each corresponds to an antistatic polypropylene composition B. i Antistatic polypropylene composition B' i The antistatic polypropylene composition A i The melting point is greater than that of the antistatic polypropylene composition B. i The antistatic polypropylene composition B' i The melting point of the outermost layer in the i-th group is greater than or equal to the average melting point of the outermost layer in the (i-1)-th group.

[0071] More preferably, the average melting point of all outer layers in group i is greater than the average melting point of all outer layers in group i-1.

[0072] Preferably, the antistatic polypropylene composition A i Melting point and antistatic polypropylene composition B i The difference in melting points, antistatic polypropylene composition A i Melting point and antistatic 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, and more preferably greater than or equal to 20°C.

[0073] Preferably, 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 is the same or different, and is 1-40°C, preferably 1-10°C, and more preferably 1-5°C.

[0074] Preferably, 2 ≤ n ≤ 100, and more preferably, 2 ≤ n ≤ 50.

[0075] Preferably, each antistatic polypropylene sheet unit group independently comprises 1 to 10, more preferably 1 to 5, identical or different antistatic polypropylene sheet units.

[0076] In a preferred embodiment of the present invention, the antistatic polypropylene composite material has at least one of the following characteristics:

[0077] Longitudinal tensile strength ≥150MPa, preferably ≥170MPa;

[0078] Interlayer peel strength ≥1N / mm, preferably ≥1.2N / mm;

[0079] 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.

[0080] When the antistatic polypropylene composite material is obtained by hot pressing 24 layers of antistatic polypropylene fabric and the thickness is about 1.6 mm, the drop hammer impact strength is ≥226 J, preferably ≥240 J.

[0081] 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.

[0082] As an example, in a preferred embodiment of the present invention, the polypropylene composite material is obtained by sequentially stacking the antistatic polypropylene sheets and / or fabrics described above to obtain a melting point gradient structure antistatic polypropylene sheet composition; preferably, the structure from bottom to top is B n A n B n ...B i A i B i ……B2A2B2, B1A1B1, B2A2B2……B i A i B i ...B n A n B n The total number of polypropylene sheet units is 2n-1; i and n are both integers not less than 2, and i≤n; the antistatic polypropylene sheets are stacked from top to bottom with the warp direction at 0-90° intervals, preferably with more than or equal to 2 layers, more preferably 2-200 layers; most preferably 4-100 layers, and the antistatic polypropylene composition A i The melting point is greater than that of the antistatic polypropylene composition B. i The antistatic polypropylene composition B i The melting point of each of the adjacent antistatic polypropylene compositions B is greater than or equal to that of the other two. i-1 Its melting point.

[0083] A fifth aspect of the present invention is to provide a method for preparing the antistatic polypropylene composite material described in the fourth aspect, the method comprising hot-pressing and fusing the antistatic polypropylene sheet and / or the antistatic polypropylene fabric together, and then cooling and shaping it to form the antistatic polypropylene composite material.

[0084] Preferably, the temperature of the hot-pressing fusion is 115-170°C, more preferably 115-159°C, and even more preferably 140-159°C.

[0085] Preferably, the pressure of the hot-press fusion is 2-10 MPa.

[0086] Preferably, the preheating time for hot pressing fusion is 5-600s, and the hot pressing time is 1-600s, preferably 10-500s.

[0087] Preferably, the cooling and shaping pressure is 2-8 MPa, and the cooling and shaping time is 30-700 s.

[0088] Preferably, the antistatic polypropylene sheet and / or the antistatic polypropylene fabric stack has more than or equal to 2 layers, preferably 2-200 layers; more preferably 4-100 layers.

[0089] Preferably, adjacent layers of the antistatic polypropylene fabric stack are placed at an angle of 0-90° between the warp and weft directions.

[0090] Preferably, adjacent layers of the antistatic polypropylene sheet stack are placed at 0-90° along their respective machine directions.

[0091] As an example, in a more preferred embodiment of the present invention, the method for preparing the high-strength, high-impact, and antistatic polypropylene composite material includes the following steps:

[0092] Step a: Co-extruding antistatic polypropylene composition A and antistatic polypropylene composition B according to the BAB structure and then casting or calendering to obtain antistatic polypropylene co-extruded sheet; preferably, the extrusion casting or calendering temperature is 200-240℃, and the temperature of the calendering roll is 50-70℃;

[0093] Step b: The antistatic polypropylene co-extruded sheet is stretched at a certain temperature to obtain an antistatic polypropylene stretched sheet; the stretching method is free stretching, and / or solid-phase stretching, and / or multi-stage stretching; the stretching temperature is preferably 90-165℃, more preferably 90-140℃, and even more preferably 90-119℃; the stretching ratio is 1-20 times, preferably 2-15 times.

[0094] Step c: Cut the antistatic polypropylene stretched sheet into antistatic polypropylene flat strips, and weave the flat strips into antistatic polypropylene fabrics; preferably, the width of the polypropylene flat strips is 2-5mm, and the antistatic polypropylene fabrics include plain weave, twill weave, satin weave or other three-dimensional polypropylene fabrics.

[0095] Step d: The antistatic polypropylene fabrics are sequentially stacked and hot-pressed together, and then cooled and shaped to form an antistatic 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 antistatic polypropylene composite material can be placed at 0-90° between the warp and weft directions.

[0096] 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 or other three-dimensional antistatic polypropylene fabrics using a commercial weaving machine according to the designed fabric structure.

[0097] 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.

[0098] In the preparation process, the antistatic polypropylene sheets and / or the antistatic polypropylene fabric 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 the aforementioned preparation equipment is used to prepare the antistatic polymer composite material, the polymer composite material exhibits better tensile strength, impact performance, and interlaminar peel strength.

[0099] The sixth aspect of the present invention is to provide the application of the antistatic polypropylene sheet described in the first aspect, the antistatic polypropylene fabric described in the third aspect, the antistatic polypropylene composite material described in the fourth aspect, and the antistatic polypropylene composite material prepared by the preparation method described in the fifth aspect in the fields of sports protection, automobile manufacturing, military materials, and consumer products.

[0100] 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.

[0101] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0102] (1) Antistatic polypropylene composite material is obtained by hot pressing the antistatic polypropylene sheet. It can have good tensile properties, impact resistance and electrical properties at the same time, and still has good interlayer peel strength when prepared at a low hot pressing temperature.

[0103] (2) The antistatic polypropylene composite polymer of the present invention has good tensile strength, impact performance, interlaminar peel strength and antistatic performance.

[0104] The antistatic polypropylene composite material has the following characteristics:

[0105] Longitudinal (MD) tensile strength ≥150MPa, preferably ≥170MPa; interlaminar peel strength ≥1N / mm, preferably ≥1.2N / mm; volume resistivity 10 2 -10 9 Ω·m, preferably 10 2 -10 6 Ω·m; When the composite material is made of only 24 layers of antistatic polypropylene fabric hot-pressed together and the thickness is about 1.6 mm, the drop hammer impact strength is ≥226 J, preferably ≥240 J.

[0106] (3) The antistatic polypropylene composite material of the present invention is suitable for preparation at a lower hot pressing temperature and a wider hot pressing temperature range, which effectively reduces the energy consumption of equipment and the damage to the composite material under high temperature operation. At the same time, it still has good interlayer peel strength when prepared at a lower hot pressing temperature.

[0107] (4) This preparation method can reduce the hot pressing operation time, while improving production efficiency and reducing production energy consumption.

[0108] (5) The present invention reduces the hot pressing temperature and expands the hot pressing temperature range to 50°C; effectively reducing equipment energy consumption and damage to composite materials under high temperature operation. Detailed Implementation

[0109] The present invention will now be described in detail with reference to specific 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.

[0110] 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:

[0111] (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.

[0112] (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.

[0113] (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 final heating curve was used to determine the melting point or melting range of the material.

[0114] (4) Sheet tensile strength: The tensile strength shall be determined in accordance with the method specified in GB / T1040.1-2018.

[0115] (5) Drop hammer impact strength: The test shall be conducted in accordance with the method specified in GB / T14153-1993.

[0116] (6) Interlayer peel strength: The test shall be performed in accordance with the method specified in QB / T2358-98.

[0117] (7) Density, determined according to the method specified in GB / T 1033.1-2008;

[0118] (8) Volume resistivity: tested using a Keithley 6517B Electrometer.

[0119] 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.

[0120] Example 1

[0121] This embodiment illustrates the preparation of the antistatic polypropylene composition, the three-layer co-extruded antistatic polypropylene sheet, the antistatic polypropylene fabric, and the antistatic polypropylene composite material provided by the present invention.

[0122] (1) Preparation of antistatic polypropylene composition A:

[0123] 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 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 (impact strength 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 °C; the conductive filler is multi-walled carbon nanotubes, purchased from Cheap Tubes, Inc., USA.

[0124] The components prepared above were weighed and mixed according to the specified proportions, with component a (Wa) comprising 80 parts by weight, component b (Wb) comprising 20 parts by weight, and carbon nanotubes comprising 3 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, antistatic polypropylene composition granules were obtained. The melt flow rate (MFRA) was measured to be 4.5 / 10 min; the melting point of antistatic polypropylene composition A was 157°C.

[0125] (2) Preparation of antistatic polypropylene composition B:

[0126] 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 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 230℃ and 2.16 kg load is 1.4 g / 10 min. The conductive filler is multi-walled carbon nanotubes purchased from Cheap Tubes, Inc.

[0127] The components prepared above were weighed and mixed according to the ratio, wherein the mass part of component x, Wx, was 85 parts by weight, the mass part of component y, Wy, was 15 parts by weight, and the carbon nanotubes were 3 parts by weight. Other steps were the same as in step (1). Finally, antistatic polypropylene composition B granules were obtained. The melt flow rate MFRB was tested to be 5.1 g / 10 min, and the melting point was 138 °C.

[0128] (3) Preparation of three-layer co-extruded antistatic polypropylene sheets:

[0129] The antistatic polypropylene composition A and antistatic polypropylene composition B granules obtained in steps (1) and (2) above are dried. Then, antistatic polypropylene composition A is added to the core extruder of a multilayer extrusion calender, and antistatic polypropylene composition B is added to the upper and lower surface extruders of a multilayer extrusion casting machine.

[0130] 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.

[0131] The extrusion casting temperature is 230℃, and the calendering roll temperature is 55℃. During solid-phase stretching, the temperature is 135℃, the stretching rate is 2 m / min, and the stretching ratio is 7 times. After stretching, the film is wound up to produce an antistatic polypropylene sheet (composite film), which consists of an upper surface layer (antistatic film layer B), a core layer (antistatic film layer A), and a lower surface layer (antistatic film layer B).

[0132] The thickness of the antistatic polypropylene sheet (composite film) mentioned above is 82 μm, wherein the thickness of film layer A accounts for 80% of the total thickness of the sheet.

[0133] (4) Preparation of antistatic polypropylene fabric:

[0134] The three-layer co-extruded antistatic polypropylene sheet obtained in step (3) above is cut into a high-speed slitting machine with multiple blades to obtain an oriented antistatic polypropylene flat strip with a width of 3mm; the oriented flat strip is woven into a commercial weaving machine according to the designed fabric structure to obtain a plain weave antistatic polypropylene fabric.

[0135] (5) Preparation of antistatic polypropylene composite material:

[0136] The antistatic polypropylene fabrics obtained in step (4) were sequentially laminated and hot-pressed to form laminated antistatic polypropylene sheets. The laminated antistatic polypropylene sheets consist of 24 layers of antistatic polypropylene fabric, with the fabrics positioned at a 90° angle between the warp and weft directions. 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 antistatic polypropylene composite material was 1.70mm.

[0137] Example 2

[0138] This embodiment illustrates the preparation of the antistatic polypropylene composition, the three-layer co-extruded antistatic polypropylene sheet, the antistatic polypropylene fabric, and the antistatic polypropylene composite material provided by the present invention.

[0139] (1) Preparation of antistatic polypropylene composition A:

[0140] 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 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℃; the graphene is edge-modified graphene produced by the Beijing Research Institute of Chemical Industry of Sinopec.

[0141] The components obtained above were weighed and mixed according to the specified proportions, with component a (Wa) comprising 70 parts by weight, component b (Wb) comprising 30 parts by weight, and graphene comprising 2 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 being melted and mixed evenly by the screws, extruded, granulated, and dried, antistatic polypropylene composition granules were obtained. The melt flow rate (MFRA) was measured to be 7.0 / 10 min, and the melting point of antistatic polypropylene composition A was 161°C.

[0142] (2) Preparation of antistatic polypropylene composition B:

[0143] 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 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 230℃ and a load of 2.16 kg. The graphene is edge-modified graphene produced by Sinopec Beijing Research Institute of Chemical Industry.

[0144] 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, component y had a mass fraction of 20 parts by weight (Wy), and graphene had a mass fraction of 2 parts by weight. Other steps were the same as in step (1). Finally, antistatic polypropylene composition B granules were obtained, and its melt flow rate (MFRB) was measured to be 9.5 g / 10 min. The melting point of antistatic polypropylene composition B is 130 °C.

[0145] (3) Preparation of three-layer co-extruded antistatic polypropylene sheets:

[0146] The preparation process is the same as step (3) in Example 1.

[0147] (4) Preparation of antistatic polypropylene fabric:

[0148] The preparation process is the same as step (4) of Example 1.

[0149] (5) Preparation of antistatic polypropylene composite material:

[0150] The preparation process is the same as step (5) in Example 1.

[0151] The thickness of the prepared antistatic polypropylene composite material is similar to that of Example 1.

[0152] Example 3

[0153] This embodiment illustrates the preparation of the antistatic polypropylene composition, the three-layer co-extruded antistatic polypropylene sheet, the antistatic polypropylene fabric, and the antistatic polypropylene composite material provided by the present invention.

[0154] (1) Preparation of antistatic polypropylene composition A:

[0155] Same as Example 1, wherein component a (Wa) has 90 parts by weight, component b (Wb) has 10 parts by weight, and the carbon nanotube content is 3 parts by weight. 0.05 parts by weight of β-crystal nucleating agent (VP101B) are added. Antistatic polypropylene composition A granules are obtained, with a melt flow rate (MFRA) of 6.6 / 10 min and a melting point of 158°C.

[0156] (2) Preparation of antistatic polypropylene composition B:

[0157] Same as in Example 1, wherein the mass fraction of component x, Wx, is 90 parts by weight, the mass fraction of component y, Wy, is 10 parts by weight, and the carbon nanotubes are 3 parts by weight, and finally antistatic polypropylene composition B granules are obtained. The melt flow rate MFRB was tested to be 8.3 g / 10 min, and the melting point of antistatic polypropylene composition B is 139 °C.

[0158] (3) Preparation of three-layer co-extruded antistatic polypropylene sheets:

[0159] The preparation process is the same as step (3) in Example 1.

[0160] (4) Preparation of antistatic polypropylene fabric:

[0161] The preparation process is the same as step (4) of Example 1.

[0162] (5) Preparation of antistatic polypropylene composite material:

[0163] The preparation process is the same as step (5) in Example 1.

[0164] The thickness of the prepared antistatic polypropylene composite material is similar to that of Example 1.

[0165] Example 4

[0166] This embodiment illustrates the preparation of the antistatic polypropylene composition, the three-layer co-extruded antistatic polypropylene sheet, the antistatic polypropylene fabric, and the antistatic polypropylene composite material provided by the present invention.

[0167] (1) Preparation of antistatic polypropylene composition A:

[0168] The preparation process is the same as step (1) in Example 1.

[0169] (2) Preparation of antistatic polypropylene composition B:

[0170] The preparation process is the same as step (2) of Example 1.

[0171] (3) Preparation of three-layer co-extruded antistatic polypropylene sheets:

[0172] The main steps are the same as in Example 1. The thickness of the polypropylene sheet is 82 μm, wherein the thickness of the film layer Ai accounts for 90% of the total thickness of the sheet.

[0173] (4) Preparation of antistatic polypropylene fabric:

[0174] The preparation process is the same as step (4) of Example 1.

[0175] (5) Preparation of antistatic polypropylene composite material:

[0176] The preparation process is the same as step (5) in Example 1.

[0177] The thickness of the prepared polypropylene composite material is similar to that of Example 1.

[0178] Example 5

[0179] This embodiment illustrates the preparation of the antistatic polypropylene composition, the three-layer co-extruded antistatic polypropylene sheet, the antistatic polypropylene fabric, and the antistatic polypropylene composite material provided by the present invention.

[0180] (1) Preparation of antistatic polypropylene composition A:

[0181] The preparation process is the same as step (1) in Example 1.

[0182] (2) Preparation of antistatic polypropylene composition B:

[0183] The preparation process is the same as step (2) of Example 1.

[0184] (3) Preparation of three-layer co-extruded antistatic polypropylene sheets:

[0185] The main steps are the same as in Example 1. 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.

[0186] (4) Preparation of antistatic polypropylene fabric:

[0187] The preparation process is the same as step (4) of Example 1.

[0188] (5) Preparation of antistatic polypropylene composite material:

[0189] The preparation process is the same as step (5) in Example 1.

[0190] The thickness of the prepared antistatic polypropylene composite material is similar to that of Example 1.

[0191] Example 6

[0192] This embodiment illustrates the preparation of the antistatic polypropylene composition, the three-layer co-extruded antistatic polypropylene sheet, the antistatic polypropylene fabric, and the antistatic polypropylene composite material provided by the present invention.

[0193] (1) Preparation of antistatic polypropylene composition A:

[0194] The preparation process is the same as step (1) in Example 1.

[0195] (2) Preparation of antistatic polypropylene composition B:

[0196] The preparation process is the same as step (2) of Example 1.

[0197] (3) Preparation of three-layer co-extruded antistatic polypropylene sheets:

[0198] The preparation process is the same as step (3) in Example 1.

[0199] (4) Preparation of antistatic polypropylene fabric:

[0200] The main steps are the same as step (4) in Example 1. The oriented flat strip is woven into a satin antistatic polypropylene fabric by using a commercial weaving machine according to the designed fabric structure.

[0201] (5) Preparation of antistatic polypropylene composite material:

[0202] The preparation process is the same as step (5) in Example 1.

[0203] The thickness of the prepared antistatic polypropylene composite material is similar to that of Example 1.

[0204] Example 7

[0205] This embodiment illustrates the preparation of the antistatic polypropylene composition, the three-layer co-extruded antistatic polypropylene sheet, the antistatic polypropylene fabric, and the antistatic polypropylene composite material provided by the present invention.

[0206] (1) Preparation of antistatic polypropylene composition A:

[0207] The preparation process is the same as step (1) in Example 1.

[0208] (2) Preparation of antistatic polypropylene composition B:

[0209] The preparation process is the same as step (2) of Example 1.

[0210] (3) Preparation of three-layer co-extruded antistatic polypropylene sheets:

[0211] The main preparation process is the same as step (3) in Example 1. The sheet stretching ratio is 10 times.

[0212] (4) Preparation of antistatic polypropylene fabric:

[0213] The preparation process is the same as step (4) of Example 1.

[0214] (5) Preparation of antistatic polypropylene composite material:

[0215] The preparation process is the same as step (5) in Example 1.

[0216] The thickness of the prepared antistatic polypropylene composite material is similar to that of Example 1.

[0217] Example 8

[0218] This embodiment illustrates the preparation of the antistatic polypropylene composition, the three-layer co-extruded antistatic polypropylene sheet, the antistatic polypropylene fabric, and the antistatic polypropylene composite material provided by the present invention.

[0219] (1) Preparation of antistatic polypropylene composition A:

[0220] The preparation process is the same as step (1) in Example 1.

[0221] (2) Preparation of antistatic polypropylene composition B:

[0222] The preparation process is the same as step (2) of Example 1.

[0223] (3) Preparation of three-layer co-extruded antistatic polypropylene sheets:

[0224] The main preparation process is the same as step (3) of Example 1. Among them, the stretching process is multi-stage stretching. In the first stage of solid-phase stretching, the temperature is 138℃, the stretching rate is 2m / min, and the stretching ratio is 7 times. The stretched sheet is then subjected to a second stage of free stretching at a temperature of 140℃, a stretching rate of 0.5m / min, and a stretching ratio of 2 times.

[0225] The resulting polypropylene sheet (composite film) has a stretch ratio of 14 times.

[0226] (4) Preparation of antistatic polypropylene fabric:

[0227] The preparation process is the same as step (4) of Example 1.

[0228] (5) Preparation of antistatic polypropylene composite material:

[0229] The preparation process is the same as step (5) in Example 1.

[0230] The thickness of the prepared antistatic polypropylene composite material is 1.59 mm.

[0231] Example 9

[0232] This embodiment illustrates the preparation of the antistatic polypropylene composition, the three-layer co-extruded antistatic polypropylene sheet, the antistatic polypropylene fabric, and the antistatic polypropylene composite material provided by the present invention.

[0233] (1) Preparation of antistatic polypropylene composition A:

[0234] The preparation process is the same as step (1) in Example 1.

[0235] (2) Preparation of antistatic polypropylene composition B:

[0236] The preparation process is the same as step (2) of Example 1.

[0237] (3) Preparation of three-layer co-extruded antistatic polypropylene sheets:

[0238] The preparation process is the same as step (3) in Example 1.

[0239] (4) Preparation of antistatic polypropylene fabric:

[0240] The preparation process is the same as step (4) of Example 1.

[0241] (5) Preparation of antistatic polypropylene composite material:

[0242] The main preparation process is the same as step (5) in Example 1. The polypropylene fabric is placed at a 45° angle between the warp and weft directions.

[0243] The thickness of the prepared antistatic polypropylene composite material is similar to that of Example 1.

[0244] Example 10

[0245] This embodiment illustrates the preparation of the antistatic polypropylene composition, the three-layer co-extruded antistatic polypropylene sheet, the antistatic polypropylene fabric, and the antistatic polypropylene composite material provided by the present invention.

[0246] (1) Preparation of antistatic polypropylene composition A:

[0247] The preparation process is the same as step (1) in Example 1.

[0248] (2) Preparation of antistatic polypropylene composition B:

[0249] The preparation process is the same as step (2) of Example 1.

[0250] (3) Preparation of three-layer co-extruded antistatic polypropylene sheets:

[0251] The preparation process is the same as step (3) in Example 1.

[0252] (4) Preparation of antistatic polypropylene fabric:

[0253] The preparation process is the same as step (4) of Example 1.

[0254] (5) Preparation of antistatic polypropylene composite material:

[0255] The main preparation process is the same as step (5) in Example 1. The polypropylene fabric is placed with the warp direction at 0° to the warp direction.

[0256] The thickness of the prepared antistatic polypropylene composite material is similar to that of Example 1.

[0257] Example 11

[0258] This embodiment illustrates the preparation of the antistatic polypropylene composition, the three-layer co-extruded antistatic polypropylene sheet, the antistatic polypropylene fabric, and the antistatic polypropylene composite material provided by the present invention.

[0259] (1) Preparation of antistatic polypropylene composition A:

[0260] The preparation process is the same as step (1) in Example 1.

[0261] (2) Preparation of antistatic polypropylene composition B:

[0262] The preparation process is the same as step (2) of Example 1.

[0263] (3) Preparation of three-layer co-extruded antistatic polypropylene sheets:

[0264] The preparation process is the same as step (3) in Example 1.

[0265] (4) Preparation of antistatic polypropylene fabric:

[0266] The preparation process is the same as step (4) of Example 1.

[0267] (5) Preparation of antistatic polypropylene composite material:

[0268] The main steps are the same as in Example 1. The laminated antistatic polypropylene sheet includes two layers of antistatic polypropylene fabric. The hot-pressing conditions used are: temperature 140℃, hot-pressing pressure 2MPa, preheating time 120s, hot-pressing time 10s, and cooling time 300s. The thickness of the prepared antistatic polypropylene composite material is 130μm.

[0269] Example 12

[0270] This embodiment illustrates the preparation of the antistatic polypropylene composition, the three-layer co-extruded antistatic polypropylene sheet, the antistatic polypropylene fabric, and the antistatic polypropylene composite material provided by the present invention.

[0271] (1) Preparation of antistatic polypropylene composition A:

[0272] The preparation process is the same as step (1) in Example 1.

[0273] (2) Preparation of antistatic polypropylene composition B:

[0274] The preparation process is the same as step (2) of Example 1.

[0275] (3) Preparation of three-layer co-extruded antistatic polypropylene sheets:

[0276] The preparation process is the same as step (3) in Example 1.

[0277] (4) Preparation of antistatic polypropylene fabric:

[0278] The preparation process is the same as step (4) of Example 1.

[0279] (5) Preparation of antistatic polypropylene composite material:

[0280] The main steps are the same as in Example 1. The laminated polypropylene sheet includes 100 layers of antistatic 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 7.27 mm.

[0281] Example 13

[0282] This embodiment illustrates the preparation of the antistatic polypropylene composition, the three-layer co-extruded antistatic polypropylene sheet, the antistatic polypropylene fabric, and the antistatic polypropylene composite material provided by the present invention.

[0283] (1) Preparation of antistatic polypropylene composition A:

[0284] The preparation process is the same as step (1) in Example 1.

[0285] (2) Preparation of antistatic polypropylene composition B:

[0286] The preparation process is the same as step (2) of Example 1.

[0287] (3) Preparation of three-layer co-extruded antistatic polypropylene sheets:

[0288] The preparation process is the same as step (3) in Example 1.

[0289] (4) Preparation of antistatic polypropylene fabric:

[0290] The preparation process is the same as step (4) of Example 1.

[0291] (5) Preparation of antistatic polypropylene composite material:

[0292] The main steps are the same as in Example 1. 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 antistatic polypropylene composite material is 1.58mm.

[0293] Example 14

[0294] This embodiment illustrates the preparation of the antistatic polypropylene composition, the three-layer co-extruded antistatic polypropylene sheet, the antistatic polypropylene fabric, and the antistatic polypropylene composite material provided by the present invention.

[0295] (1) Preparation of antistatic polypropylene composition A:

[0296] The preparation process is the same as step (1) in Example 1.

[0297] (2) Preparation of antistatic polypropylene composition B:

[0298] The preparation process is the same as step (2) of Example 1.

[0299] (3) Preparation of three-layer co-extruded antistatic polypropylene sheets:

[0300] The preparation process is the same as step (3) in Example 1.

[0301] (4) Preparation of antistatic polypropylene composite material:

[0302] Instead of preparing polypropylene fabric, the three-layer co-extruded antistatic polypropylene sheet obtained in step (3) was used to replace the antistatic polypropylene fabric obtained in step (4) of Example 1, and the sheets were sequentially stacked and hot-pressed according to step (5) of Example 1. The thickness of the prepared antistatic polypropylene composite material was 1.51 mm.

[0303] Example 15

[0304] This embodiment illustrates the preparation of the antistatic polypropylene composition, the three-layer co-extruded antistatic polypropylene sheet, the antistatic polypropylene fabric, and the antistatic polypropylene composite material provided by the present invention.

[0305] (1) Antistatic polypropylene composition A i Preparation:

[0306] 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 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; conductive filler is edge-modified graphene self-made by Sinopec Beijing Chemical Research Institute. The above-prepared components are weighed and mixed according to the proportions, wherein component a (Wa) has a mass fraction of 80 parts by weight, component b (Wb) has a mass fraction of 20 parts by weight, and graphene has a mass fraction of 2 parts by weight.

[0307] 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°C. After being melted and mixed evenly by the screws, extruded, granulated, and dried, polypropylene composition granules A are obtained. i The polypropylene composition granules A were tested. i Its melting point is 157℃.

[0308] (2) Antistatic polypropylene composition B i Preparation:

[0309] Component x1 is a random copolymer polypropylene self-produced by Sinopec Beijing Research Institute of Chemical Industry, which is an ethylene-propylene-butene terpolymer with a melt flow rate of 8.1 g / 10 min and a melting point of 130℃; Component x2 is a random copolymer polypropylene self-produced by Sinopec Beijing Research Institute of Chemical Industry, which is an ethylene-propylene-butene terpolymer with a melt flow rate of 7.2 g / 10 min and a melting point of 135℃; Component x3 is a random copolymer polypropylene self-produced by Sinopec Beijing Research Institute of Chemical Industry, which is 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; The conductive filler is edge-modified graphene self-produced by Sinopec Beijing Research Institute of Chemical Industry.

[0310] The components obtained above are weighed and mixed according to the specified proportions, wherein component x i mass parts Wx i The total weight is 85 parts by weight, the weight of component y is 15 parts by weight, the weight of graphene is 2 parts by weight, and the other steps are the same as in step (1), finally obtaining the antistatic polypropylene composition B. 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℃.

[0311] (3) Preparation of three-layer co-extruded antistatic polypropylene sheets:

[0312] The antistatic polypropylene composition A obtained in steps (1) and (2) above i and antistatic polypropylene composition B i The granules are dried, and then the antistatic polypropylene composition A is applied. i Add the antistatic polypropylene composition B to the core layer extruder of the multilayer extrusion calendering process. iThe 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.

[0313] An antistatic 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 It consists of a 80μm thick antistatic composite film, with film layer A accounting for 80% of the total sheet thickness.

[0314] (4) Preparation of antistatic polypropylene fabric:

[0315] The three-layer co-extruded antistatic 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 antistatic polypropylene fabrics B1AB1, B2AB2, and B3AB3.

[0316] (5) Preparation of antistatic polypropylene composite material:

[0317] The antistatic 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 an antistatic 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.

[0318] Example 16

[0319] This embodiment illustrates the preparation of the antistatic polypropylene composition, the three-layer co-extruded antistatic polypropylene sheet, the antistatic polypropylene fabric, and the antistatic polypropylene composite material provided by the present invention.

[0320] (1) Antistatic polypropylene composition A i Preparation:

[0321] The preparation process is the same as step (1) in Example 3.

[0322] (2) Antistatic polypropylene composition B i Preparation:

[0323] The main preparation process is the same as step (2) in Example 3. The difference is that component B... i and x i The materials selected are as follows:

[0324] Component x1 is a 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℃; Component x2 is a 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℃; Component x3 is a 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 x4 is a 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 125℃; Component x5 is a random copolymer polypropylene produced by the Beijing Research Institute of Chemical Industry, Sinopec, which is an ethylene-propylene-butene terpolymer. The material has a melting point of 130℃; component x6 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 melt flow rate of components x1-x9 is 1-20 g / 10 min.

[0325] The final antistatic polypropylene composition B is 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℃.

[0326] (3) Preparation of three-layer co-extruded antistatic polypropylene sheets:

[0327] The preparation process is the same as step (3) in Example 3.

[0328] (4) Preparation of antistatic polypropylene fabric:

[0329] The preparation process is the same as step (4) in Example 3.

[0330] (5) Preparation of antistatic polypropylene composite material:

[0331] The antistatic polypropylene fabrics obtained in step (4) are stacked sequentially, from bottom to top as B9A9B. 9… The polypropylene fabrics 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 produce an antistatic 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 1.25mm.

[0332] Comparative Example 1

[0333] Three-layer co-extruded antistatic polypropylene sheets were prepared according to the method of Example 1. However, only antistatic polypropylene composition A was used for extrusion casting into a single-layer film with a thickness of 81 μm. Antistatic polypropylene fabrics and antistatic polypropylene composites were also prepared according to the method of Example 1.

[0334] The thickness of the prepared antistatic polypropylene composite material is similar to that of Example 1.

[0335] Comparative Example 2

[0336] Three-layer co-extruded antistatic polypropylene sheets were prepared according to the method of Example 1. However, only antistatic polypropylene composition B was used for extrusion casting into a single-layer film with a thickness of 79 μm. Antistatic polypropylene fabrics and antistatic polypropylene composites were also prepared according to the method of Example 1.

[0337] The thickness of the prepared antistatic polypropylene composite material is similar to that of Example 1.

[0338] Comparative Example 3

[0339] Three-layer co-extruded antistatic polypropylene sheets were prepared according to the method of Example 1. However, the antistatic polypropylene composition A contained only component b. Antistatic polypropylene fabrics and antistatic polypropylene composites were prepared according to the method of Example 1.

[0340] The thickness of the prepared antistatic polypropylene composite material is similar to that of Example 1.

[0341] Comparative Example 4

[0342] Three-layer co-extruded antistatic polypropylene sheets were prepared according to the method of Example 1. However, the antistatic polypropylene composition B contained only component y. Antistatic polypropylene fabrics and antistatic polypropylene composites were also prepared according to the method of Example 1.

[0343] The thickness of the prepared antistatic polypropylene composite material is similar to that of Example 1.

[0344] Comparative Example 5

[0345] A three-layer co-extruded antistatic polypropylene sheet was prepared according to the method of Example 1, wherein the thickness of the film layer A accounts for 95% of the total thickness of the sheet. Antistatic polypropylene fabric and antistatic polypropylene composite material were also prepared according to the method of Example 1.

[0346] The thickness of the prepared polypropylene composite material is similar to that of Example 1.

[0347] Comparative Example 6

[0348] A three-layer co-extruded antistatic polypropylene sheet was prepared according to the method of Example 1, wherein the thickness of the antistatic film layer A accounts for 50% of the total thickness of the sheet. Antistatic polypropylene fabric and antistatic polypropylene composite material were also prepared according to the method of Example 1.

[0349] The thickness of the prepared antistatic polypropylene composite material is similar to that of Example 1.

[0350] Comparative Example 7

[0351] Co-extruded antistatic polypropylene sheets were prepared according to the method of Example 15, except that component Bi was selected as follows: component x1 was 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 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 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 melt flow rate of components x1-x3 was 2-10 g / 10 min.

[0352] The final antistatic polypropylene composition B is obtained. i Granular material (i.e., x) i +y=B i (i = 1, 2, 3), the melting point of B1 was found to be 138℃, the melting point of B2 was 132℃, and the melting point of B3 was 127℃. Antistatic polypropylene fabrics and antistatic polypropylene composites were prepared according to the method of Example 15.

[0353] The thickness of the prepared polypropylene composite material is similar to that of Example 15.

[0354] Comparative Example 8

[0355] Three-layer co-extruded antistatic polypropylene sheets were prepared according to the method of Example 1. Antistatic polypropylene fabrics were prepared according to the method of Example 1. The main steps for preparing the antistatic polypropylene composite material were the same as in Example 1. The only differences were the hot-pressing temperature (110°C), hot-pressing pressure (12 MPa), preheating time (300 s), hot-pressing time (300 s), and cooling time (700 s). The thickness of the prepared polypropylene composite material was 1.50 mm.

[0356] Comparative Example 9

[0357] Three-layer co-extruded antistatic polypropylene sheets were prepared according to the method of Example 1. Antistatic polypropylene fabrics were prepared according to the method of Example 1. The main steps for preparing the antistatic polypropylene composite material were the same as in Example 1. The only differences were the hot-pressing temperature (175°C), hot-pressing pressure (2 MPa), preheating time (300 s), hot-pressing time (300 s), and cooling time (700 s). The thickness of the prepared antistatic polypropylene composite material was 1.57 mm.

[0358] Comparative Example 10

[0359] Three-layer co-extruded polypropylene sheets were prepared according to the method of Example 1, except that conductive fillers were not added. Polypropylene fabrics and polypropylene composites were also prepared according to the method of Example 1.

[0360] The thickness of the prepared polypropylene composite material is similar to that of Example 1.

[0361] Experimental Example

[0362] 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.

[0363] (1) Tensile strength: Samples were prepared and tested according to the methods specified in GB / T1040.1-2018;

[0364] (2) Interlayer peel strength: Samples were prepared and measured in accordance with the method specified in QB / T2358-98.

[0365] (3) Drop hammer impact strength: The test shall be conducted in accordance with the method specified in GB / T14153-1993.

[0366] (4) Volume resistivity: tested using a Keithley 6517B Electrometer.

[0367] Among them, when the polypropylene composite materials obtained in the corresponding embodiments and comparative examples are similar to those in Example 1, the thickness is about 1.6 mm, and is within the range of 1.6 mm ± 1 mm.

[0368] Table 1

[0369]

[0370] The results from the examples in Table 1 show that the antistatic polypropylene composite material prepared according to the present invention possesses excellent tensile properties, impact resistance, and electrical properties, while also exhibiting good interlaminar peel strength at relatively low hot-pressing temperatures. The antistatic polypropylene composite sheet of the present invention has a longitudinal (MD) tensile strength ≥160 MPa, an interlaminar peel strength ≥1.10 N / mm, and a volume resistivity less than 10 N / mm². 7 Ω·m; The areal density of the antistatic polypropylene composite material is 1520 g / m² when it is made of 24 layers of antistatic polypropylene fabric hot-pressed together with a thickness of about 1.6 mm. 2 When the temperature is around 100°C, the drop hammer impact strength is ≥226 J. The longitudinal (MD) tensile strength of the antistatic polypropylene composite material with a melting point gradient structure described in this invention is ≥160 MPa, the interlaminar peel strength is ≥1.3 N / mm, and the volume resistivity is less than 10 N / mm². 7 Ω·m; When the composite material is made of only 5 layers of polypropylene fabric hot-pressed together and the thickness is only about 391μm, the drop hammer impact strength is ≥42J.

[0371] As can be seen from the preferred embodiments 1-3, the antistatic polypropylene composite material prepared by the present invention has a longitudinal (MD) tensile strength ≥170MPa, an interlaminar peel strength ≥1.2N / mm, and a volume resistivity less than 10 N / mm. 7 Ω·m; The areal density of the antistatic polypropylene composite material is 1520 g / m² when it is made of 24 layers of antistatic polypropylene fabric hot-pressed together with a thickness of about 1.6 mm. 2 When the hammer is in the left or right position, the impact strength of the falling hammer is ≥240J.

[0372] As can be seen from preferred embodiments 15-16, the antistatic polypropylene composite material with melting point gradient structure prepared by the present invention has a longitudinal (MD) tensile strength ≥180MPa, an interlaminar peel strength ≥1.5N / mm, and a volume resistivity less than 10 N / mm. 7 Ω·m; When the composite material is made of only 5 layers of antistatic polypropylene fabric hot-pressed together and is only about 391μm thick, the drop hammer impact strength is ≥45J.

[0373] As can be seen from Comparative Examples 1-9, 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 antistatic polypropylene sheets or fabrics. Using process conditions outside the scope of the examples will significantly reduce the tensile strength, impact performance, or interlayer peel strength of the obtained antistatic polypropylene composite material.

[0374] 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.

[0375] 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 sheet comprising layer A and layers B and B' located on both sides of layer A, having a structure of BAB'; Layer A contains polypropylene composition A and conductive filler. Layer B may be the same as or different from layer B', each containing conductive filler and correspondingly containing polypropylene composition B and polypropylene composition B'. The melting point of polypropylene composition A is greater than the melting points 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 reinforcing agent y; based on the total weight of the polypropylene composition A, the polypropylene composition A comprises 50-99 wt% homopolymer polypropylene a and 1-50 wt% impact copolymer polypropylene b. 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.

2. The polypropylene sheet according to claim 1, 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, Relative to 100 parts by weight of polypropylene composition A, the content of conductive filler in layer A is 0.1-10 parts by weight; 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, 10-20 wt% heat-bonding reinforcing agent y; and / or, Relative to 100 parts by weight of each of polypropylene composition B and polypropylene composition B', the content of conductive filler in layer B and layer B' is 0.1-10 parts by weight.

3. The polypropylene sheet according to claim 1, characterized in that: The content of conductive filler in layer A is 1-3 parts by weight relative to 100 parts by weight of polypropylene composition A; and / or, Relative to 100 parts by weight of each of polypropylene composition B and polypropylene composition B', the content of conductive filler in layer B and layer B' is 1-3 parts by weight.

4. The polypropylene sheet according to claim 1, 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.

5. The polypropylene sheet according to claim 1, characterized in that: Based on the total thickness of the polypropylene sheet, the thickness of layer A accounts for 71%-89% of the total thickness.

6. The polypropylene sheet according to claim 1, 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.

7. The polypropylene sheet according to claim 1, 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 isomechanics is not less than 96%.

8. The polypropylene sheet according to claim 1, 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 1-20g / 10min.

9. The polypropylene sheet according to claim 1, 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.

10. The polypropylene sheet according to claim 1, 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 .

11. The polypropylene sheet according to claim 1, 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 1-20 g / 10 min at 230°C and 2.16 kg load.

12. The polypropylene sheet according to claim 1, characterized in that: 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.

13. The polypropylene sheet according to claim 1, 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 random copolymer polypropylene x is a copolymer of propylene with ethylene and / or butene.

14. The polypropylene sheet according to claim 1, 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 1-20g / 10min; and / or, The random copolymer polypropylene x is an ethylene-propylene-butene terpolymer and / or a propylene-ethylene binary copolymer.

15. The polypropylene sheet according to claim 1, characterized in that: The random copolymer polypropylene x has: The melt flow rate at 230℃ and 2.16kg load is 3-18g / 10min.

16. The polypropylene sheet according to claim 1, 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.

17. The polypropylene sheet according to claim 1, characterized in that: The thermal bonding enhancer y has the following characteristics: The melt flow rate at 190℃ and 2.16kg load is 1-20g / 10min.

18. The polypropylene sheet according to claim 1, characterized in that: The thermal bonding enhancer y has the following characteristics: The melt flow rate at 190℃ and 2.16kg load is 1-18g / 10min.

19. The polypropylene sheet according to claim 1, characterized in that: The heat-adhesive reinforcing agent y is selected from one or more of polyolefin elastomers, ethylene propylene diene monomer (EPDM) rubber, SEBS, SBS, EVA, and petroleum resin.

20. The polypropylene sheet according to claim 1, characterized in that: The heat-adhesive reinforcing agent y is a polyolefin elastomer and / or petroleum resin.

21. The polypropylene sheet according to claim 19, characterized in that: The polyolefin elastomer is a copolymer elastomer of ethylene with propylene and / or α-olefins.

22. The polypropylene sheet according to claim 21, characterized in that: The α-olefin is a C4-C12 α-olefin.

23. The polypropylene sheet according to claim 21, characterized in that: The α-olefin is 1-butene and / or 1-octene.

24. The polypropylene sheet according to claim 19, characterized in that: The petroleum resin is a C5 and / or C9 hydrogenated petroleum resin with a softening point of 100-150℃.

25. The polypropylene sheet according to claim 19, characterized in that: The petroleum resin is a cyclopentadiene type resin.

26. The polypropylene sheet according to any one of claims 1-25, characterized in that: Layer A also contains a β-crystal nucleating agent.

27. The polypropylene sheet according to claim 26, 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, The content of the β-crystal nucleating agent in layer A is 0.01-0.5 parts by weight relative to 100 parts by weight of polypropylene composition A.

28. The polypropylene sheet according to any one of claims 1-25, characterized in that: The conductive filler is selected from at least one of carbon black conductive fillers, graphite conductive fillers, carbon nanotube conductive fillers, carbon fiber conductive fillers, conductive metal particles, conductive metal fibers, fillers coated with conductive metal, and metal oxides.

29. The polypropylene sheet according to claim 28, characterized in that: The carbon black conductive filler is at least one of acetylene black, superconducting carbon black, and highly conductive carbon black; and / or, the graphite conductive filler is at least one of natural graphite, expandable graphite, expanded graphite, and graphene; and / or, the carbon nanotube conductive filler is at least one of the following carbon nanotubes, either unmodified or surface-modified: single-walled carbon nanotubes and / or multi-walled carbon nanotubes; and / or, the conductive metal in the conductive metal particles and conductive metal fibers is independently at least one of silver, aluminum, copper, iron, nickel, and stainless steel; and / or, the filler coated with conductive metal is selected from at least one of the following materials plated with lead, nickel, or silver: glass beads, glass fibers, and mica sheets; and / or, the metal oxide is at least one of titanium oxide, zinc oxide, tin oxide, indium oxide, and cadmium oxide.

30. The polypropylene sheet according to any one of claims 1-25, 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 composition B and polypropylene composition B'; and / or, The BAB' layered structure of the polypropylene sheet is obtained by co-extruding a layer A raw material containing a polypropylene composition A and a conductive filler, a layer B raw material containing a polypropylene composition B and a conductive filler, and a layer B' raw material containing a polypropylene composition B' and a conductive filler.

31. The polypropylene sheet according to any one of claims 1-25, 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 composition B and polypropylene composition B', and the temperature difference between the corresponding melting points is greater than or equal to 10 degrees.

32. A method for preparing polypropylene sheet according to any one of claims 1-31, comprising co-extruding, casting or calendering, and stretching a layer A raw material containing a polypropylene composition A and a conductive filler, a layer B raw material containing a polypropylene composition B and a conductive filler, and a layer B' raw material containing a polypropylene composition B' and a conductive filler according to a BAB' structure to obtain the polypropylene sheet.

33. The method for preparing polypropylene sheets according to claim 32, characterized in that, The preparation of the raw material for layer A includes melt blending of components including homopolymer polypropylene a, impact copolymer polypropylene b, and conductive filler; and / or, The preparation of the raw materials for layers B and B' each includes melt blending of components including the random copolymer polypropylene x, the thermal bonding reinforcing agent y, and the conductive filler; and / or, The temperatures for co-extrusion and casting are each independently selected from 200-240°C; and / or, The rolling temperature is 50-70℃; and / or, The stretching conditions include: a stretching temperature of 90-165℃; and a stretching ratio of 1-20 times.

34. The method for preparing polypropylene sheets according to claim 32, characterized in that, The stretching conditions include: a stretching temperature of 90-140℃ and a stretching ratio of 1-20 times.

35. The method for preparing polypropylene sheets according to claim 32, characterized in that, The stretching conditions include: a stretching temperature of 90-119℃ and a stretching ratio of 1-20 times.

36. A polypropylene fabric, a three-dimensional polypropylene fabric obtained by weaving a polypropylene sheet according to any one of claims 1-31.

37. The polypropylene fabric according to claim 36, 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.

38. A polypropylene composite material, said polypropylene composite material being prepared by hot pressing together multiple layers of polypropylene sheets according to any one of claims 1-31 and / or polypropylene fabrics according to claims 36 or 37.

39. The polypropylene composite material according to claim 38, characterized in that: The polypropylene composite material is prepared by hot pressing multiple layers of the polypropylene sheets or the polypropylene fabric; and / or Multilayer polypropylene sheets are stacked from top to bottom at 0-90° angles along their respective machine directions; and / or, Multilayer polypropylene fabrics are stacked from top to bottom with warp directions arranged at 0-90° intervals; and / or, The number of layers in the multilayer polypropylene sheet and / or multilayer polypropylene fabric is greater than or equal to 2.

40. The polypropylene composite material according to claim 38, characterized in that: The number of layers in multilayer polypropylene sheets and / or multilayer polypropylene fabrics ranges from 2 to 200.

41. The polypropylene composite material according to claim 38, characterized in that: The number of layers in multilayer polypropylene sheets and / or multilayer polypropylene fabrics ranges from 4 to 100.

42. The polypropylene composite material according to any one of claims 38-41, characterized in that: The polypropylene 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 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 groups is 2n-1. Both i and n are integers not less than 2, and i ≤ n; 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 , 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.

43. The polypropylene composite material according to claim 42, 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) is the same or different, and each is between 1 and 40°C; and / or, 2≤n≤100; and / or, Each polypropylene sheet unit group, independently, comprises 1 to 10 identical or different polypropylene sheet units.

44. The polypropylene composite material according to claim 42, 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) is the same or different, each ranging from 1 to 10 °C; and / or, 2≤n≤50; and / or, Each polypropylene sheet unit group, independently, comprises 1 to 5 identical or different polypropylene sheet units.

45. The polypropylene composite material according to claim 42, 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℃.

46. ​​A method for preparing a polypropylene composite material according to any one of claims 38-45, 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.

47. The method for preparing the polypropylene composite material according to claim 46, 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 30-700 s; 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.

48. The method for preparing the polypropylene composite material according to claim 46, characterized in that: The hot-pressing fusion temperature is 115-159℃; and / or, The preheating time for the hot-pressing fusion is 5-600s, and the hot-pressing time is 10-500s; and / or, The number of layers in the polypropylene sheet and / or the polypropylene fabric stack is 2-200.

49. The method for preparing the polypropylene composite material according to claim 46, characterized in that: The hot-pressing fusion temperature is 140-159℃; and / or, The number of layers in the polypropylene sheet and / or the polypropylene fabric stack is 4-100.

50. The applications of the polypropylene sheet according to any one of claims 1-31, the polypropylene fabric according to claim 36 or 37, the polypropylene composite material according to any one of claims 38-45, and the polypropylene composite material prepared by the preparation method according to any one of claims 46-49 in the fields of sports protection, automobile manufacturing, military materials, and consumer products.

51. The application according to claim 50, characterized in that: The consumer products mentioned are for sports protection.

Images