Flame-retardant high-modulus polypropylene composite material and preparation method thereof

Abstract

The invention provides a flame-retardant high-modulus polypropylene composite material and a preparation method thereof, and relates to the technical field of composites.The flame-retardant high-modulus polypropylene composite material comprises a matrix phase, and the matrix phase comprises, by weight, 50-60 parts of polypropylene, 30-40 parts of a phosphorus-nitrogen flame retardant, 3-5 parts of a compatilizer and 0.5-1.5 parts of a dispersing agent; wherein the matrix phase comprises the following components in parts by weight: 0.5 to 1.5 parts of a scratch-resistant agent and 0.1 to 0.5 part of an antioxidant, the dispersing agent is an imidized isobutylene-maleic anhydride copolymer, the compatilizer is a polystyrene-oxazoline graft polymer, and the matrix phase further comprises the following components in parts by weight: 0.5 to 1.5 parts of a scratch-resistant agent and 0.1 to 0.5 part of an antioxidant. The flame-retardant high-modulus polypropylene composite material disclosed by the invention can comprehensively improve the flame-retardant property and the scratch resistance of the flame-retardant high-modulus polypropylene composite material.

Description

Technical Field

[0001] The invention relates to the technical field of composite materials, and in particular to a flame-retardant high modulus polypropylene composite material and a preparation method thereof. Background Art

[0002] Fiber reinforced thermoplastics are a type of structural composite material, with a tough, low modulus thermoplastic resin as the matrix phase and high strength, high modulus fiber as the reinforcement phase. They have the advantages of high strength, low density, corrosion resistance, and a wide range of resin matrix options. Among them, the matrix phase material usually uses polymer materials such as polypropylene, polystyrene, and nylon. The reinforcement phase usually uses reinforcing fibers such as glass fiber, carbon fiber, steel fiber, and synthetic fiber.

[0003] At present, the precipitation problem of flame retardant materials often occurs in flame retardant high modulus polypropylene composite materials, which is more obvious in halogen-free flame retardant materials. The precipitation of flame retardants not only produces mold scale, powder agglomeration, mold sticking, etc., affecting normal production, but also often precipitates in finished products, producing white mist-like substances that affect the product appearance and cause a decrease in flame retardancy. Therefore, the development of flame retardant high modulus polypropylene composite materials with excellent flame retardant properties has become an urgent problem to be solved in this field. Summary of the invention

[0004] The invention aims to improve the flame retardant performance of a flame retardant high modulus polypropylene composite material.

[0005] In order to solve the above problems, the present invention provides a flame retardant high modulus polypropylene composite material and a preparation method thereof.

[0006] In a first aspect, the present invention provides a flame retardant high modulus polypropylene composite material, the flame retardant high modulus polypropylene composite material comprises a matrix phase, the matrix phase comprises the following components in parts by weight: 50-60 parts of polypropylene, 30-40 parts of phosphorus nitrogen flame retardant, 3-5 parts of compatibilizer and 0.5-1.5 parts of dispersant;

[0007] Wherein, the dispersant is an imidized isobutylene-maleic anhydride copolymer, and the compatibilizer is a polystyrene-oxazoline graft polymer.

[0008] Optionally, the matrix phase further comprises 0.5-1.5 parts of a scratch resistant agent and 0.1-0.5 parts of an antioxidant, based on parts by weight.

[0009] Optionally, the antioxidant includes a hindered phenol antioxidant and / or a phosphate antioxidant.

[0010] Optionally, the phosphorus-nitrogen flame retardant includes at least one of melamine polyphosphate, piperazine phosphate, polyphosphate amine and triphenyl phosphate.

[0011] Optionally, the polypropylene has a melt flow rate at 230° C. of (20-50) g / 10 min.

[0012] Optionally, the flame-retardant high modulus polypropylene composite material further includes glass fiber cloth, and the matrix phase is laid on the surface of the glass fiber cloth.

[0013] Optionally, the mass ratio of the matrix phase to the glass fiber cloth is (3-4):(6-7).

[0014] In a second aspect, the present application also provides a method for preparing the flame retardant high modulus polypropylene composite material, comprising:

[0015] The polypropylene, phosphorus-nitrogen flame retardant, dispersant, compatibilizer, scratch resistant agent and antioxidant are mixed, stirred evenly and then melt-extruded to obtain a matrix phase;

[0016] The matrix phase is layered on the glass fiber cloth and then pressed to obtain a flame retardant high modulus polypropylene composite material.

[0017] Optionally, the temperature of the melt extrusion is 190-220°C.

[0018] Optionally, the pressing temperature is 200-240° C. and the pressure is 20-30 MPa.

[0019] The beneficial effects of the present invention are:

[0020] The present invention adds a phosphorus-nitrogen flame retardant to a polypropylene substrate, adds a polystyrene-oxazoline graft polymer as a compatibilizer, and uses an imidized copolymer of isobutylene and maleic anhydride as a dispersant. The compatibilizer uses the polar functional group of the oxazoline group to react with the amide bond and the phosphorus-oxygen bond in the phosphorus-nitrogen flame retardant, thereby effectively improving the compatibility of the polypropylene substrate and the phosphorus-nitrogen flame retardant. The compatibilizer has a strong binding ability with the silicon-oxygen bond in the glass fiber cloth, and can improve the rigidity of the composite material. The imidized copolymer of isobutylene and maleic anhydride can effectively disperse the phosphorus-nitrogen flame retardant in the polypropylene substrate by using its own polar and non-polar functional groups, so that the flame retardant is not easy to precipitate from the material, and the flame retardant stability of the material is further improved. DETAILED DESCRIPTION

[0021] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as those commonly understood by those skilled in the art to which this application belongs; the terms used in the specification of this application are only for the purpose of describing specific implementation methods and are not intended to limit this application;

[0023] The term "including" and its variations used in this article are open inclusions, that is, "including but not limited to"; the term "based on" is "based at least in part on"; the term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one other embodiment"; the term "some embodiments" means "at least some embodiments"; the term "optionally" means "optional embodiments". The relevant definitions of other terms will be given in the following description. It should be noted that the concepts of "first" and "second" mentioned in the present invention are used to distinguish different objects, rather than to describe a specific order or a primary and secondary relationship. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise specified, the meaning of "multiple" is two or more.

[0024] In order to improve the flame retardant properties of polypropylene materials, an embodiment of the present invention provides a flame retardant high modulus polypropylene composite material and a preparation method thereof.

[0025] In the first aspect, the embodiment of the present invention discloses a flame retardant high modulus polypropylene composite material, which includes a matrix phase, wherein the matrix phase includes the following components in parts by weight: 50-60 parts of polypropylene, 30-40 parts of phosphorus nitrogen flame retardant, 3-5 parts of compatibilizer and 0.5-1.5 parts of dispersant. The dispersant is a copolymer of imidized isobutylene and maleic anhydride, and the compatibilizer is a polystyrene-oxazoline graft polymer.

[0026] The present invention adds a phosphorus-nitrogen flame retardant to a polypropylene substrate, adds a polystyrene-oxazoline graft polymer as a compatibilizer, and uses an imidized copolymer of isobutylene and maleic anhydride as a dispersant. The compatibilizer uses the polar functional group of the oxazoline group to react with the amide bond and the phosphorus-oxygen bond in the phosphorus-nitrogen flame retardant, thereby effectively improving the compatibility of the polypropylene substrate and the phosphorus-nitrogen flame retardant. The compatibilizer has a strong binding ability with the silicon-oxygen bond in the glass fiber cloth, and can improve the rigidity of the composite material. The imidized copolymer of isobutylene and maleic anhydride can effectively disperse the phosphorus-nitrogen flame retardant in the polypropylene substrate by using its own polar and non-polar functional groups, so that the flame retardant is not easy to precipitate from the material, and the flame retardant stability of the material is further improved.

[0027] Optionally, the number average molecular weight of the dispersant is between 50,000 and 90,000, the dispersant is specifically ISOBAM-304 (Kuraray) or ISOBAM-306 (Kuraray), and the compatibilizer is specifically RPS-1005 (Japan Catalyst). The phosphorus-nitrogen flame retardant includes at least one of melamine polyphosphate, piperazine phosphate, polyphosphate amine and triphenyl phosphate. Specifically, NP-200, APP, and NP-264 of UBO.

[0028] Optionally, the matrix phase further includes 0.5-1.5 parts of a scratch resistant agent and / or 0.1-0.5 parts of an antioxidant, by weight. The scratch resistant agent is a grafted polymer of a high molecular additive, specifically including SD-199 (Shanghai Shengdian) and AS-999 (Jianyi); the antioxidant is a hindered phenol antioxidant and / or a phosphate antioxidant, specifically including antioxidants 168, 1010, 626, and 1098 from BASF of Germany.

[0029] In the flame-retardant high modulus polypropylene composite material in the embodiment of the present invention, the scratch-resistant agent is a reactive scratch-resistant agent, specifically a multi-head block copolymer, with a melting point of 140-150°C. During the molding process, the scratch-resistant agent chemically reacts with the material to form a smooth film on its surface, which effectively improves the scratch resistance of the material and does not fail for a long time. The antioxidant can react with free radicals or peroxides in polypropylene to prevent the occurrence of polypropylene oxidation reaction, thereby protecting the physical properties and chemical stability of the polypropylene material. In addition, the flame-retardant high modulus polypropylene composite material obtained in the embodiment of the present invention does not contain halogen elements, is more environmentally friendly, and has excellent environmental performance.

[0030] Optionally, the flame-retardant high modulus polypropylene composite material in the embodiment of the present invention further comprises glass fiber cloth, and the mass ratio of the matrix phase to the glass fiber cloth is (3-4): (6-7). The glass fiber cloth is a plain cloth woven from untwisted coarse yarn on a gingham loom, and has a weight of 600 g / cm 2 .

[0031] In the embodiment of the present invention, the mass ratio of the glass fiber cloth to the matrix phase is adjusted to the above range, so that the glass fiber cloth has a higher content and a certain thickness, which is beneficial to improving the strength and rigidity of the material.

[0032] Optionally, the melt flow rate of polypropylene at 230° C. is (20-50) g / 10 min. Using polypropylene with a fluidity within this range as the base material can ensure that the polypropylene flame retardant material can easily impregnate the glass fiber cloth without overflowing.

[0033] In a second aspect, an embodiment of the present invention provides a method for preparing the flame retardant high modulus polypropylene composite material, comprising:

[0034] S1: polypropylene, phosphorus nitrogen flame retardant, dispersant, compatibilizer, anti-scratch agent and antioxidant are mixed, stirred evenly and then melt-extruded to obtain a matrix phase. Specifically, a twin-screw extruder is used, the main engine speed is adjusted to 300-500r / min, and melt-extrusion granulation is performed. The processing temperature of each region during melt extrusion is 190-220°C.

[0035] S2: Laying the matrix phase on the glass fiber cloth, and then pressing and molding to obtain a flame-retardant high modulus polypropylene composite material. Specifically, the lamination is performed by stacking a layer of cloth and a layer of matrix phase. The pressing temperature is 200-240°C and the pressure is 20-30Mpa. Pressing within this temperature and pressure range is conducive to ensuring the molding quality.

[0036] The present invention is further described below in conjunction with specific embodiments.

[0037] Example 1

[0038] It should be noted that in this embodiment, polypropylene comes from SK's BH3800 (28g / 10min), compatibilizer comes from Nippon Catalyst Co., Ltd.'s RPS-1005, phosphorus-nitrogen flame retardant comes from UBO's NP-200, dispersant comes from Kuraray's ISOBAM-304, scratch resistant agent comes from Shanghai Shengdian's SD-199, antioxidant comes from BASF's antioxidant 1010 and antioxidant 168. Fiberglass cloth comes from Chongqing International Composites' EWR600.

[0039] This embodiment provides a method for preparing a flame retardant high modulus polypropylene composite material, comprising:

[0040] S1: Mix 50 parts of BH3800 (SK), 40 parts of NP-200 (UB), 1.5 parts of ISOBAM-304 (Kuraray), 5 parts of RPS-1005 (Japan Catalyst), 1.5 parts of SD-199 (Shanghai Shengdian), 0.2 parts of antioxidant 1010 (BASF, Germany) and 0.2 parts of antioxidant 168 (BASF, Germany), stir well and add to the feeding system of the twin-screw extruder, adjust the main engine speed to 300r / min, adjust the processing temperature to 200℃, and perform melt extrusion to obtain the matrix phase.

[0041] S2: The matrix phase and the glass fiber cloth are layered in a mass ratio of 3:7, and a double steel plate press is used to press and mold them at 200° C. and 30 MPa to obtain a flame-retardant high modulus polypropylene composite material.

[0042] Example 2

[0043] In this embodiment, polypropylene comes from 4181T (30g / 10min) of Formosa Plastics Corporation, compatibilizer comes from RPS-1005 of Nippon Shokubai Co., Ltd., phosphorus-nitrogen flame retardant comes from APP of UBO, dispersant comes from ISOBAM-304 of Kuraray, scratch resistant agent comes from AS-999 of Jianyi, antioxidant comes from 1790 and 168 of BASF of Germany. Fiberglass cloth comes from EWR400 of Chongqing International Composite Materials.

[0044] This embodiment provides a method for preparing a flame retardant high modulus polypropylene composite material, comprising:

[0045] S1: Mix 60 parts of 4181T (Formosa Plastics), 35 parts of APP (UB), 1 part of ISOBAM-304 (Kuraray), 5 parts of RPS-1005 (Nippon Shokubai), 1 part of AS-999 (Jianyi), 0.4 parts of antioxidant 179 (BASF, Germany) and 0.3 parts of antioxidant 168 (BASF, Germany), stir evenly and add to the feeding system of the twin-screw extruder, adjust the main engine speed to 400r / min, adjust the processing temperature to 190°C, and perform melt extrusion to obtain the matrix phase.

[0046] S2: The matrix phase and the glass fiber cloth are layered in a mass ratio of 3:6, and a double steel plate press is used to press and mold them at 220° C. and 28 MPa to obtain a flame-retardant high modulus polypropylene composite material.

[0047] Example 3

[0048] In this embodiment, polypropylene is derived from S2040 (36g / 10min) of SECCO, compatibilizer is derived from RPS-1005 of Nippon Shokubai, phosphorus-nitrogen flame retardant is derived from NP-264 of UB, dispersant is derived from ISOBAM-306 of Kuraray, scratch resistant agent is derived from SD-199 of Shanghai Shengdian, antioxidant is derived from 1010 and 626 of BASF, Germany. Fiberglass cloth is derived from EWR400 of Chongqing International Composite Materials.

[0049] This embodiment provides a method for preparing a flame retardant high modulus polypropylene composite material, comprising:

[0050] S1: 55 parts of S2040 (Secco), 30 parts of NP-264 (UB), 0.5 parts of ISOBAM-306 (Kuraray), 3 parts of RPS-1005 (Japan Catalyst), 0.5 parts of SD-199 (Shanghai Shengdian), 0.5 parts of antioxidant 1010 (BASF, Germany) and 0.1 parts of antioxidant 626 (BASF, Germany) were mixed, stirred evenly and added into the feeding system of the twin-screw extruder, the main engine speed was adjusted to 500r / min, the processing temperature was adjusted to 220°C, and melt extrusion was performed to obtain the matrix phase.

[0051] S2: The matrix phase and the glass fiber cloth are layered in a mass ratio of 4:6, and a double steel plate press is used to press and mold them at 240° C. and 20 MPa to obtain a flame-retardant high modulus polypropylene composite material.

[0052] Example 4

[0053] In this embodiment, polypropylene comes from 5450XT (45g / 10min) of Formosa Plastics Corporation, compatibilizer comes from RPS-1005 of Nippon Shokubai Co., Ltd., phosphorus-nitrogen flame retardant comes from NP-200 of UBO, dispersant comes from ISOBAM-306 of Kuraray, scratch resistant agent comes from SD-199 of Shanghai Shengdian Co., Ltd., antioxidant comes from 1010 and 626 of BASF of Germany. Fiberglass cloth comes from EWR600 of Chongqing International Composite Materials.

[0054] This embodiment provides a method for preparing a flame retardant high modulus polypropylene composite material, comprising:

[0055] S1: Mix 52 parts of 5450XT (Formosa Plastics), 40 parts of NP-200 (UB), 1.5 parts of ISOBAM-306 (Kuraray), 5 parts of RPS-1005 (Japan Catalyst), 1.5 parts of SD-199 (Shanghai Shengdian), 0.5 parts of antioxidant 1010 (BASF, Germany) and 0.5 parts of antioxidant 626 (BASF, Germany), stir well and add to the feeding system of the twin-screw extruder, adjust the main engine speed to 400r / min, adjust the processing temperature to 190°C, and perform melt extrusion to obtain the matrix phase.

[0056] S2: The matrix phase and the glass fiber cloth are layered in a mass ratio of 4:7, and pressed by a double steel plate press at 230° C. and 25 MPa to obtain a flame-retardant high modulus polypropylene composite material.

[0057] Example 5

[0058] The difference between this embodiment and embodiment 1 is that in step S1 of the method for preparing the flame-retardant high modulus polypropylene composite material in this embodiment, 60 parts of S2040 (Secco), 35 parts of NP-200 (UB), 1 part of ISOBAM-304 (Kuraray), 4 parts of RPS-1005 (Japan Catalyst), 1 part of SD-199 (Shanghai Shengdian), 0.1 part of antioxidant 1098 (BASF, Germany) and 0.1 part of antioxidant 626 (BASF, Germany) are mixed. The other steps and process parameters are the same.

[0059] Example 6

[0060] The difference between this embodiment and embodiment 1 is that in step S1 of the method for preparing the flame-retardant high modulus polypropylene composite material in this embodiment, 60 parts of S2040 (Secco), 35 parts of NP-200 (UB), 1 part of ISOBAM-304 (Kuraray), 4 parts of RPS-1005 (Japan Catalyst), 1 part of SD-199 (Shanghai Shengdian), 0.3 parts of antioxidant 1098 (BASF, Germany) and 0.2 parts of antioxidant 626 (BASF, Germany) are mixed. The other steps and process parameters are the same.

[0061] Comparative Example

[0062] The difference between Comparative Examples 1-5 and Example 1 is that the components and their weight fractions in the flame retardant high modulus polypropylene composite material are different. The components of the flame retardant high modulus polypropylene composite material of Comparative Examples 1-5 are shown in Table 1:

[0063] Table 1 Components of flame retardant high modulus polypropylene composite materials of Comparative Examples 1-5

[0064]

[0065] It should be noted that in Table 1, each column is composed of specific weight parts of components of a comparative example, and the preparation process of the flame retardant high modulus polypropylene composite material in all the comparative examples is the same as that in Example 1.

[0066] The products prepared in Examples 1-6 and Comparative Examples 1-5 were tested for density according to ISO 1183-1, for tensile strength and elongation at break according to ISO 527-4, for flexural strength and flexural modulus according to ISO 14125, for flame retardancy according to UL94, and for scratch resistance according to GM W14688. The test results are shown in Tables 2 and 3:

[0067] Table 2 Test results of flame retardant high modulus polypropylene composites prepared in Examples 1-6

[0068]

[0069] Table 3 Test results of flame retardant high modulus polypropylene composites prepared in Comparative Examples 1-5

[0070]

[0071]

[0072] It can be seen from Table 2 and Table 3 that the flexural modulus of the flame-retardant high modulus polypropylene composite materials obtained in Examples 1-6 of the present invention is greater than 20Gpa, the flame retardant properties are all V0, and the scratch resistance is excellent, and the color difference change value is less than 0.5. Compared with Example 1, Comparative Example 1 uses low melt index polypropylene 1100 (melt index is 11g / 10min). Since the melt index of polypropylene is too low, the resin cannot completely impregnate the glass fiber cloth, resulting in a decrease in the rigidity of the material. Comparative Example 2 uses high melt index polypropylene 1600A (melt index is 60g / 10min), which causes the resin to overflow, further affecting the transportation stability of the material. Comparative Example 3 uses polypropylene grafted MAH as a compatibilizer. The polarity of MAH is not as good as the oxazoline group of RPS-1005, and it cannot form a strong bonding effect with the flame retardant and the glass fiber cloth, resulting in poor rigidity and flame retardant properties of the material, and the phenomenon of flame retardant material precipitation occurs. Comparative Example 4 uses EBS dispersant, which cannot effectively disperse the flame retardant, resulting in reduced flame retardancy and precipitation of flame retardant materials. Comparative Example 5 uses silicone powder as a scratch resistant agent, but cannot form an intermolecular connection with the polypropylene flame retardant material, and the scratch resistance is not as good as that of Example 1.

[0073] In summary, compared with Comparative Examples 1-5, the flame retardant high modulus polypropylene composite material in the embodiment of the present invention has excellent rigidity, flame retardancy and scratch resistance.

[0074] Comparative Example 6

[0075] The difference between this comparative example and Example 1 is that, among the components of the matrix phase in this comparative example, the weight portion of the phosphorus-nitrogen flame retardant is 35 parts, the weight portion of the compatibilizer is 2 parts, the weight portion of the dispersant is 0.3 parts, and the weight portions of other components remain unchanged. The specific commodity types and preparation processes of each component are the same as those in Example 1.

[0076] Comparative Example 7

[0077] The difference between this comparative example and Example 1 is that, among the components of the matrix phase in this comparative example, the weight portion of the phosphorus-nitrogen flame retardant is 35 parts, the weight portion of the compatibilizer is 2 parts, the weight portion of the dispersant is 1 part, and the weight portions of other components remain unchanged. The specific commodity types and preparation processes of each component are the same as those in Example 1.

[0078] Comparative Example 8

[0079] The difference between this comparative example and Example 1 is that, among the components of the matrix phase in this comparative example, the weight portion of the phosphorus-nitrogen flame retardant is 35 parts, the weight portion of the compatibilizer is 5 parts, the weight portion of the dispersant is 0.3 parts, and the weight portions of other components remain unchanged. The specific commodity types and preparation processes of each component are the same as those in Example 1.

[0080] Comparative Example 9

[0081] The difference between this comparative example and Example 1 is that, among the components of the matrix phase in this comparative example, the weight portion of the phosphorus-nitrogen flame retardant is 35 parts, the weight portion of the compatibilizer is 8 parts, the weight portion of the dispersant is 2 parts, and the weight portions of other components remain unchanged. The specific commodity types and preparation processes of each component are the same as those in Example 1.

[0082] Comparative Example 10

[0083] The difference between this comparative example and Example 1 is that in the preparation process of the flame-retardant high modulus polypropylene composite material in this comparative example, the temperature of the compression molding is 180° C. and the pressure is 18 MPa. The components of the matrix phase and other process parameters remain unchanged.

[0084] Comparative Example 11

[0085] The difference between this comparative example and Example 1 is that in the preparation process of the flame-retardant high modulus polypropylene composite material in this comparative example, the temperature of the compression molding is 250° C. and the pressure is 35 MPa. The components of the matrix phase and other process parameters remain unchanged.

[0086] The products prepared in Comparative Examples 6-11 were tested for tensile strength and elongation at break according to ISO 527-4, flexural strength and flexural modulus according to ISO 14125, and flame retardancy according to UL94. The test results are shown in Table 4:

[0087] Table 4 Test results of flame retardant high modulus polypropylene composites prepared in Comparative Examples 6-11

[0088]

[0089] It can be seen from Comparative Examples 6-9 and Table 4 that, compared with Example 1, Comparative Example 6 reduces the amount of dispersant and compatibilizer while keeping the weight of polypropylene and phosphorus nitrogen flame retardant unchanged, Comparative Example 7 reduces the weight of compatibilizer alone, and Comparative Example 8 reduces the weight of dispersant alone, which all reduce the flame retardant properties of the obtained products, and the phenomenon of flame retardant material precipitation occurs, indicating that the flame retardant properties of the materials are unstable. The reduction of compatibilizer in Comparative Examples 6 and 7 leads to the deterioration of the compatibility of polypropylene, flame retardant and glass fiber cloth, and the decrease of tensile and bending properties. Comparative Example 9 increases the amount of dispersant and compatibilizer while keeping the weight of polypropylene and phosphorus nitrogen flame retardant unchanged. Although the flame retardant properties are improved, the elongation at break of the flame retardant high modulus polypropylene composite material decreases, and the phenomenon of dispersant precipitation also occurs. This shows that adding the phosphorus-nitrogen flame retardant, dispersant and compatibilizer to the matrix phase according to the ratio set by the present invention can effectively improve the flame retardant properties of the composite material, and the flame retardant material is not easy to precipitate, the flame retardant property is more stable, and at the same time has a more stable elongation at break.

[0090] It can be seen from Comparative Examples 10-11 and Table 4 that, compared with Example 1, Comparative Example 10 reduces the temperature and pressure of the pressing molding, and the resin cannot be impregnated into the glass fiber cloth during the molding process, which reduces the rigidity of the composite material. In Comparative Example 11, the pressing molding temperature is higher than 220°C and the pressure is higher than 30MPa, and the resin is degraded, which affects the rigidity of the product and increases the cost.

[0091] Although the present invention is disclosed as above, the protection scope of the present invention is not limited thereto. Those skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention, and these changes and modifications will fall within the protection scope of the present invention.

Claims

1. A flame retardant high modulus polypropylene composite material, characterized in that: The invention comprises a matrix phase, wherein the matrix phase comprises the following components in parts by weight: 50-60 parts of polypropylene, 30-40 parts of phosphorus-nitrogen flame retardant, 3-5 parts of compatibilizer and 0.5-1.5 parts of dispersant; Wherein, the dispersant is an imidized isobutylene-maleic anhydride copolymer, and the compatibilizer is a polystyrene-oxazoline graft polymer.

2. The flame retardant high modulus polypropylene composite material according to claim 1, characterized in that: The matrix phase further comprises 0.5-1.5 parts of a scratch resistant agent and 0.1-0.5 parts of an antioxidant, in parts by weight.

3. The flame retardant high modulus polypropylene composite material according to claim 1, characterized in that: The phosphorus-nitrogen flame retardant includes at least one of melamine polyphosphate, piperazine phosphate, polyphosphate amine and triphenyl phosphate.

4. The flame retardant high modulus polypropylene composite material according to claim 2, characterized in that: The antioxidant includes a hindered phenol antioxidant and / or a phosphate antioxidant.

5. The flame retardant high modulus polypropylene composite material according to claim 1, characterized in that: The melt flow rate of the polypropylene at 230° C. is (20-50) g / 10 min.

6. The flame retardant high modulus polypropylene composite material according to claim 1, characterized in that: It also includes glass fiber cloth, and the matrix phase is laid on the surface of the glass fiber cloth.

7. The flame-retardant high modulus polypropylene composite material according to claim 6, characterized in that: The mass ratio of the matrix phase to the glass fiber cloth is (3-4):(6-7).

8. A method for preparing a flame retardant high modulus polypropylene composite material, for preparing the flame retardant high modulus polypropylene composite material according to any one of claims 1 to 7, characterized in that: include: The polypropylene, phosphorus-nitrogen flame retardant, dispersant, compatibilizer, scratch resistant agent and antioxidant are mixed, stirred evenly and then melt-extruded to obtain a matrix phase; The matrix phase is layered on the glass fiber cloth and then pressed to obtain a flame retardant high modulus polypropylene composite material.

9. The method for preparing the flame-retardant high modulus polypropylene composite material according to claim 8, characterized in that: The temperature of the melt extrusion is 190-220°C.

10. The method for preparing the flame-retardant high modulus polypropylene composite material according to claim 8, characterized in that: The temperature of the compression molding is 200-240° C., and the pressure is 20-30 MPa.

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