A fast-crystallizing flame-retardant polypropylene composite material and its preparation method

Abstract

The present invention relates to a fast-crystallizing flame-retardant polypropylene composite material and a preparation method thereof. By weight, the polypropylene composite material comprises 80-95 parts of polypropylene, 2-5 parts of a flame retardant, 5-10 parts of talcum powder, 0.3-0.6 parts of a nucleating agent, and 0.4-0.8 parts of a processing aid; the nucleating agent is a mixture of NA-11 and HPN-68L; the preparation method is as follows: after mixing each component evenly according to the weight ratio, adding the mixture into a twin-screw extruder for extrusion molding to obtain a fast-crystallizing flame-retardant polypropylene masterbatch, and after fully mixing the fast-crystallizing flame-retardant polypropylene masterbatch evenly, adding the masterbatch into a twin-screw extruder for secondary extrusion molding to prepare the fast-crystallizing flame-retardant polypropylene composite material. The preparation method of the present invention has a simple process; the shrinkage rate change of the prepared fast-crystallizing polypropylene composite material within 12-24 h after injection molding does not exceed 0.03%, and the shrinkage rate change within 24-48 h does not exceed 0.02%.

Description

Technical Field

[0001] The present invention belongs to the technical field of functional polymer composite materials, and particularly relates to a rapidly crystallizing flame-retardant polypropylene composite material and a preparation method thereof. Background Art

[0002] As a widely used thermoplastic material, polypropylene has the advantages of low price, convenient processing method, chemical resistance, heat resistance, electrical insulation, high-strength mechanical properties, and good high-abrasion resistance processing performance, etc., which makes it widely developed and applied in the fields of household appliances, automobiles, electronic appliances, etc.

[0003] Polypropylene is a crystalline plastic. After injection molding, it needs to be placed for a period of time to continue cooling and crystallizing so that the molecular chains are "frozen" and the size no longer shrinks, thereby maintaining dimensional stability. However, this makes the product storage cycle longer, the production cost increases, and the production efficiency of the product decreases, especially for parts that require rapid prototyping.

[0004] Chinese Patent CN115322479B discloses a low post-shrinkage polypropylene material and a preparation method thereof. By introducing a specific low-shrinkage regulator into polypropylene, the random copolymer polypropylene and polyamide contained therein can form composite molecular chain entanglement among the three, effectively inhibiting the post-shrinkage effect after the product size is stabilized and even after heat treatment, and the dimensional stability persistence is strong.

[0005] Chinese Patent CN103665541B discloses a low post-shrinkage polypropylene composite material prepared by controlling fluidity and a preparation method thereof. By filling high melt index polypropylene, the molecular weight distribution of polypropylene in the composite material is increased, the nucleation rate is improved, the shrinkage after injection molding is reduced, and the prepared polypropylene composite material has good gloss and low post-shrinkage.

[0006] Although the above patents have a certain improvement effect on the shrinkage rate of polypropylene materials, they still cannot meet the requirements of rapid prototyping of parts. Moreover, for the rapidly developing flame-retardant polypropylene materials, flame retardants need to be filled in the polypropylene materials. The addition of flame retardants will reduce the crystallization rate of the materials, and will further lead to a decrease in the production efficiency of the composite materials during the production process, and cannot be applied to parts that require rapid prototyping.

[0007] Therefore, it is of great significance to study a rapidly crystallizing flame-retardant polypropylene composite material and a preparation method thereof to solve the above problems. Summary of the Invention

[0008] The object of the present invention is to provide a fast-crystallizing flame-retardant polypropylene composite material and a preparation method thereof, which can reduce the post-shrinkage of the flame-retardant polypropylene composite material, improve the dimensional stability of the product, reduce the storage period of the product, reduce the cost in the production process, and improve the production efficiency.

[0009] In order to achieve the above object, the technical solution of the present invention is as follows:

[0010] A fast-crystallizing flame-retardant polypropylene composite material, comprising the following components in parts by weight:

[0011]

[0012] The filled mineral is talc powder;

[0013] The nucleating agent is a mixture of NA-11 and HPN-68L;

[0014] The flame-retardant grade of the fast-crystallizing flame-retardant polypropylene composite material is 1.6 mm V2;

[0015] The shrinkage rate change of the fast-crystallizing flame-retardant polypropylene composite material within 12-24 h after injection molding does not exceed 0.03%, and the shrinkage rate change within 24-48 h does not exceed 0.02%.

[0016] As a preferred technical solution:

[0017] For the fast-crystallizing flame-retardant polypropylene composite material as described above, when the weight ratio of the nucleating agent NA-11 to HPN-68L is 1:1, the synergistic effect between NA-11 and HPN-68L in the composite nucleating agent is the best, the post-shrinkage of the prepared polypropylene composite material is the smallest, and the size is more stable.

[0018] For the fast-crystallizing flame-retardant polypropylene composite material as described above, the polypropylene is homopolypropylene.

[0019] For the fast-crystallizing flame-retardant polypropylene composite material as described above, the melt index of the homopolypropylene under the test conditions of 230 °C and 2.16 kg is 1-60 g / 10 min.

[0020] For the fast-crystallizing flame-retardant polypropylene composite material as described above, the processing aids are antioxidant and dispersant.

[0021] For the fast-crystallizing flame-retardant polypropylene composite material as described above, the antioxidant is antioxidant 168 and / or antioxidant 1010, and the dispersant is SG-200A.

[0022] The present invention also provides a preparation method of the fast-crystallizing flame-retardant polypropylene composite material as described in any one of the above, comprising the following steps:

[0023] (1) Mix polypropylene, a flame retardant, a filler mineral, a nucleating agent, and a processing aid evenly, and then add them to a twin-screw extruder for extrusion molding to obtain a fast-crystallizing flame-retardant polypropylene masterbatch;

[0024] (2) After fully mixing the fast-crystallizing flame-retardant polypropylene masterbatch obtained in step (1), add it to a twin-screw extruder for secondary extrusion molding to prepare a fast-crystallizing flame-retardant polypropylene composite material.

[0025] As a preferred technical solution:

[0026] For the preparation method of a fast-crystallizing flame-retardant polypropylene composite material as described above, in steps (1) and (2), the mixing is carried out using a high-speed mixer, and the mixing time is 10 - 15 min; the rotation speed of the high-speed mixer is 300 rpm.

[0027] For the preparation method of a fast-crystallizing flame-retardant polypropylene composite material as described above, in steps (1) and (2), the temperature range of each zone of the twin-screw extruder is 160 - 170 °C.

[0028] Principle of the invention:

[0029] In the prior art, doped talc powder is mostly used to fill and reinforce PP materials to improve the modulus of the materials or adjust the shrinkage rate of the materials. In the present invention, low-concentration talc powder is doped in polypropylene, which can restrict the movement of a part of the polypropylene molecular chains, reduce the movement ability of the molecular chains, avoid excessive entanglement of the polymer chain segments, make the molecular chain arrangement more regular and orderly, and is beneficial to crystallization. And when talc powder is added to polypropylene, it can provide crystal nuclei for the polypropylene crystallization process, promote heterogeneous nucleation crystallization, and the appearance of a large number of crystal nuclei will further refine the spherulites, and the arrangement of the polypropylene crystals will be more compact.

[0030] The two benzene rings in the nucleating agent NA-11 molecule form a V-shaped structure, which can effectively stabilize the structure of polypropylene. At the same time, the benzene ring structure of the nucleating agent NA-11 molecule contains two tert-butyl structures. The tert-butyl group and the methyl group both belong to alkyl groups, and intermolecular interactions are generated with the alkyl groups in the HPN-68L molecular chain. The affinity and van der Waals force between the groups are enhanced, making the molecular chain arrangement of the polypropylene composite material more compact. During the crystallization process, the crystallization rate of the polypropylene composite material increases significantly;

[0031] Specifically, during the crystallization process of the polypropylene composite material, talc powder at a low concentration, together with the composite nucleating agents NA-11 and HPN-68L, provides crystal nuclei for the crystallization of polypropylene simultaneously, playing a role of multiple heterogeneous nucleations on polypropylene. The number of crystal nuclei increases, and spherulites collide with each other before they have time to grow, making the crystal arrangement more compact. At the same time, talc powder at a low concentration effectively restricts the movement of polypropylene molecular chains, further accelerating the crystallization of polypropylene, shortening the crystallization cycle, and enabling the workpiece to complete crystallization at a higher temperature.

[0032] During the processing and use, due to the changes in temperature and external environment, the crystals are damaged, and the frozen molecular chains start to move. During the crystallization process, due to the combined action of the above-mentioned system (i.e., talc powder and nucleating agent), the crystallization rate of the material is increased, and the molecular chains move rapidly until they are "frozen", so the dimensional stability of the product remains very good.

[0033] Beneficial effects

[0034] (1) In the preparation method of a fast-crystallizing flame-retardant polypropylene composite material of the present invention, talc powder at a low concentration effectively restricts the movement of polypropylene molecular chains, further accelerating the crystallization of polypropylene; the combined synergistic effect of talc powder at a low concentration in the polypropylene composite material and the composite nucleating agents NA-11 and HPN-68L plays a role of heterogeneous nucleation on polypropylene. Especially when the weight ratio of the nucleating agent NA-11 to HPN-68L is 1:1, the effect is the best, and the post-shrinkage of the prepared polypropylene composite material is small and the size is more stable;

[0035] (2) In the preparation method of a fast-crystallizing flame-retardant polypropylene composite material of the present invention, the process is simple. Through secondary extrusion molding, compared with single extrusion molding, the dispersibility of the filler in polypropylene can be improved, enabling the filler to be better dispersed in polypropylene;

[0036] (3) A fast-crystallizing flame-retardant polypropylene composite material of the present invention has both excellent flame-retardant performance and fast-crystallizing performance, and has broad application prospects in the fields of household appliances, automobiles, and electronic appliances, etc., and has good promotion value;

[0037] (4) A fast-crystallizing flame-retardant polypropylene composite material of the present invention can reduce the product storage cycle, which greatly improves production efficiency and reduces production costs. Specific embodiments

[0038] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of this application.

[0039] The test methods involved in the examples and comparative examples are as follows:

[0040] Flame retardant grade: Tested in accordance with GB / T 2408-2008;

[0041] Shrinkage rate: Tested in accordance with ASTM D955-00; The rapid crystallization behavior of the rapid crystallization flame retardant polypropylene composite prepared by the present invention is evaluated by calculating the shrinkage rate changes of the composite within 12 h to 24 h and 24 h to 48 h after injection molding; Specifically, according to the standard method of ASTM D955-00, after the products of the examples and comparative examples are injection molded, they are placed in an environment with a temperature of 25 °C and a relative humidity of 45-55%, and the injection molding shrinkage rates of each product at 12 h, 24 h, and 48 h are measured and recorded as S1, S2, and S3; The shrinkage rate change from 12 h to 24 h = S2 - S1, and the shrinkage rate change from 24 h to 48 h = S3 - S2.

[0042] The raw material information used in the examples and comparative examples of the present invention is as follows:

[0043] Homopolypropylene A: Zhenhai Refining & Chemical PPH-T03, with a melt index of 2.0 g / 10 min at 230 °C and a load of 2.16 kg;

[0044] Homopolypropylene B: Yangzi Petrochemical S700, with a melt index of 10.0 g / 10 min at 230 °C and a load of 2.16 kg;

[0045] Homopolypropylene C: Hongji Petrochemical PPH225, with a melt index of 23.0 g / 10 min at 230 °C and a load of 2.16 kg;

[0046] Homopolypropylene D: Zhenhai Refining & Chemical M60T, with a melt index of 60.0 g / 10 min at 230 °C and a load of 2.16 kg;

[0047] Flame retardant: Manufacturer is Zhejiang Xusen, grade is FR-8801.

[0048] Talc powder: Manufacturer is Suzhou Youtuoke, grade is T2.

[0049] Nucleating agent NA-11: Manufacturer is ADEKA of Japan;

[0050] Nucleating agent HPN-68L: Manufacturer is Milliken of the United States;

[0051] Antioxidant: BASF, a mixture of antioxidant 168 and antioxidant 1010;

[0052] Dispersant: Manufacturer is Zhejiang Jiahua, grade is SG-200A.

[0053] Example 1

[0054] A preparation method of a fast-crystallizing flame-retardant polypropylene composite material is as follows:

[0055] (1) Preparation of raw materials:

[0056] Polypropylene: homopolypropylene A, with a melt index of 2 g / 10 min under the test conditions of 230 °C and 2.16 kg;

[0057] Flame retardant;

[0058] Filler mineral: talc powder;

[0059] Nucleating agent: a mixture of NA-11 and HPN-68L with a weight ratio of 1:1;

[0060] Processing aid: a mixture of an antioxidant and dispersant SG-200A with a weight ratio of 1:1, where the antioxidant is a mixture of antioxidant 168 and antioxidant 1010 with a weight ratio of 1:1;

[0061] (2) By weight, 93 parts of polypropylene, 2 parts of flame retardant, 5 parts of filler mineral, 0.3 part of nucleating agent, and 0.4 part of processing aid are mixed evenly in a high-speed mixer at a speed of 300 rpm for 15 min, and then added to a twin-screw extruder for extrusion molding to obtain a fast-crystallizing flame-retardant polypropylene masterbatch;

[0062] Among them, the temperatures of each zone of the twin-screw extruder are 160 °C, 160 °C, 170 °C, 170 °C, 170 °C, 170 °C, 170 °C, 170 °C, 170 °C respectively;

[0063] (3) The fast-crystallizing flame-retardant polypropylene masterbatch obtained in step (2) is mixed evenly in a high-speed mixer at a speed of 300 rpm for 15 min, and then added to a twin-screw extruder for secondary extrusion molding to obtain a fast-crystallizing flame-retardant polypropylene composite material;

[0064] Among them, the temperatures of each zone of the twin-screw extruder are 160 °C, 160 °C, 170 °C, 170 °C, 170 °C, 170 °C, 170 °C, 170 °C, 170 °C respectively.

[0065] The final fast-crystallizing flame-retardant polypropylene composite material has a flame retardancy rating of 1.6 mm V2; the shrinkage rate change of the fast-crystallizing flame-retardant polypropylene composite material is 0.01% from 12 to 24 h after injection molding, and 0.01% from 24 to 48 h.

[0066] Comparative Example 1

[0067] A preparation method of a fast-crystallizing flame-retardant polypropylene composite material is basically the same as that of Example 1, except that the polypropylene is a copolymer polypropylene, the manufacturer is Formosa Plastics, and the grade is 3080.

[0068] The flame-retardant grade of the finally prepared fast-crystallizing flame-retardant polypropylene composite material is HB; the shrinkage rate change of the fast-crystallizing flame-retardant polypropylene composite material is 0.02% from 12 to 24 h after injection molding, and the shrinkage rate change is 0.01% from 24 to 48 h.

[0069] Comparing Example 1 and Comparative Example 1, it can be found that although replacing homopolypropylene with copolymer polypropylene has little effect on the post-shrinkage of the product, it will affect the flame-retardant performance of the product, and the flame-retardant grade is reduced from V2 to HB; in order to achieve the same level of flame-retardant efficiency, a higher filling amount of flame retardant is required, which greatly increases the production cost.

[0070] Comparative Example 2

[0071] A preparation method of a fast-crystallizing flame-retardant polypropylene composite material is basically the same as that of Example 1, except that the raw material does not contain talcum powder, and the weight fraction of homopolypropylene A is 98 parts, that is, talcum powder is replaced with an equal weight fraction of homopolypropylene.

[0072] The flame-retardant grade of the finally prepared fast-crystallizing flame-retardant polypropylene composite material is 1.6mm V2; the shrinkage rate change of the fast-crystallizing flame-retardant polypropylene composite material is 0.05% from 12 to 24 h after injection molding, and the shrinkage rate change is 0.03% from 24 to 48 h.

[0073] Comparing Example 1 and Comparative Example 2, it can be found that filling a low content of talcum powder into the flame-retardant polypropylene composite material system can restrict the movement of some polypropylene molecular chains, avoid excessive entanglement of polymer chain segments, make the arrangement of polypropylene crystals more regular and orderly, and the prepared polypropylene composite material has better dimensional stability.

[0074] Comparative Example 3

[0075] A preparation method of a fast-crystallizing flame-retardant polypropylene composite material is basically the same as that of Example 1, except that the raw material does not contain nucleating agent HPN-68L, that is, nucleating agent NA-11 is used to replace nucleating agent HPN-68L with an equal weight fraction.

[0076] The flame-retardant grade of the finally prepared fast-crystallizing flame-retardant polypropylene composite material is 1.6mm V2; the shrinkage rate change of the fast-crystallizing flame-retardant polypropylene composite material is 0.07% from 12 to 24 h after injection molding, and the shrinkage rate change is 0.04% from 24 to 48 h.

[0077] Comparative Example 4

[0078] A preparation method of a fast-crystallizing flame-retardant polypropylene composite material is basically the same as that of Example 1, except that the raw materials do not contain nucleating agent NA-11, that is, nucleating agent HPN-68L with the same weight parts is used to replace nucleating agent NA-11.

[0079] The flame-retardant grade of the finally prepared fast-crystallizing flame-retardant polypropylene composite material is 1.6mm V2; the shrinkage rate change of the fast-crystallizing flame-retardant polypropylene composite material is 0.06% from 12 to 24 hours after injection molding, and the shrinkage rate change is 0.03% from 24 to 48 hours.

[0080] Comparing Example 1, Comparative Example 3 and Comparative Example 4, it can be found that there is a synergistic effect between NA-11 and HPN-68L in the composite nucleating agent, which greatly increases the crystallization rate of the polypropylene composite material during the crystallization process and can be applied to parts for rapid prototyping. And combining with Example 2 and Example 3 later, when the weight part ratio of nucleating agent NA-11 to nucleating agent HPN-68L is 1:1, the post-shrinkage of the prepared polypropylene composite material is the smallest and the size is more stable.

[0081] Comparative Example 5

[0082] A preparation method of a fast-crystallizing flame-retardant polypropylene composite material is basically the same as that of Example 1, except that single extrusion molding is adopted, that is, the operation of step (3) is not carried out.

[0083] The flame-retardant grade of the finally prepared fast-crystallizing flame-retardant polypropylene composite material is 1.6mm V2; the shrinkage rate change of the fast-crystallizing flame-retardant polypropylene composite material is 0.04% from 12 to 24 hours after injection molding, and the shrinkage rate change is 0.03% from 24 to 48 hours.

[0084] Comparing Example 1 and Comparative Example 5, it can be found that the shrinkage rate change of the fast-crystallizing flame-retardant polypropylene composite material increases from 0.01% to 0.04% from 12 to 24 hours after injection molding, and the shrinkage rate change increases from 0.01% to 0.03% from 24 to 48 hours. This is because increasing the shear times of the screw can improve the dispersion of the filler in the polypropylene and make the filler better dispersed in the polypropylene.

[0085] Example 2

[0086] A preparation method of a fast-crystallizing flame-retardant polypropylene composite material is as follows:

[0087] (1) Preparation of raw materials:

[0088] Polypropylene: homopolypropylene A, with a melt index of 2g / 10min under the test conditions of 230°C and 2.16kg;

[0089] Flame retardant;

[0090] Filler mineral: talcum powder;

[0091] Nucleating agent: a mixture of NA-11 and HPN-68L with a weight ratio of 2:1;

[0092] Processing aid: a mixture of antioxidant and dispersant SG-200A with a weight ratio of 1:1, where the antioxidant is a mixture of antioxidant 168 and antioxidant 1010 with a weight ratio of 1:1;

[0093] (2) By weight, 93 parts of polypropylene, 2 parts of flame retardant, 5 parts of filler mineral, 0.3 part of nucleating agent, and 0.4 part of processing aid are mixed evenly in a high-speed mixer at a speed of 300 rpm for 15 minutes, and then added to a twin-screw extruder for extrusion molding to obtain a fast-crystallizing flame-retardant polypropylene masterbatch;

[0094] Among them, the temperatures of each zone of the twin-screw extruder are 160 °C, 160 °C, 170 °C, 170 °C, 170 °C, 170 °C, 170 °C, 170 °C, 170 °C respectively.

[0095] (3) The fast-crystallizing flame-retardant polypropylene masterbatch obtained in step (2) is mixed evenly in a high-speed mixer at a speed of 300 rpm for 15 minutes, and then added to a twin-screw extruder for secondary extrusion molding to obtain a fast-crystallizing flame-retardant polypropylene composite material;

[0096] Among them, the temperatures of each zone of the twin-screw extruder are 160 °C, 160 °C, 170 °C, 170 °C, 170 °C, 170 °C, 170 °C, 170 °C, 170 °C respectively.

[0097] The flame-retardant grade of the finally obtained fast-crystallizing flame-retardant polypropylene composite material is 1.6 mm V2; the shrinkage rate change of the fast-crystallizing flame-retardant polypropylene composite material is 0.03% from 12 to 24 hours after injection molding, and 0.02% from 24 to 48 hours.

[0098] Example 3

[0099] A preparation method of a fast-crystallizing flame-retardant polypropylene composite material, the specific steps are as follows:

[0100] (1) Preparation of raw materials:

[0101] Polypropylene: homopolypropylene A, with a melt index of 2 g / 10 min under the test conditions of 230 °C and 2.16 kg;

[0102] Flame retardant;

[0103] Filler mineral: talcum powder;

[0104] Nucleating agent: A mixture of NA-11 and HPN-68L with a weight ratio of 1:2;

[0105] Processing aid: A mixture of an antioxidant and dispersant SG-200A with a weight ratio of 1:1, where the antioxidant is a mixture of antioxidant 168 and antioxidant 1010 with a weight ratio of 1:1;

[0106] (2) By weight, 93 parts of polypropylene, 2 parts of flame retardant, 5 parts of filled mineral, 0.3 part of nucleating agent, and 0.4 part of processing aid were mixed evenly in a high-speed mixer at 300 rpm for 15 min, and then added to a twin-screw extruder for extrusion molding to obtain a fast-crystallizing flame-retardant polypropylene masterbatch;

[0107] Among them, the temperatures of each zone of the twin-screw extruder were 160 °C, 160 °C, 170 °C, 170 °C, 170 °C, 170 °C, 170 °C, 170 °C, 170 °C respectively;

[0108] (3) After the fast-crystallizing flame-retardant polypropylene masterbatch obtained in step (2) was mixed evenly in a high-speed mixer at 300 rpm for 15 min, it was added to a twin-screw extruder for secondary extrusion molding to obtain a fast-crystallizing flame-retardant polypropylene composite;

[0109] Among them, the temperatures of each zone of the twin-screw extruder were 160 °C, 160 °C, 170 °C, 170 °C, 170 °C, 170 °C, 170 °C, 170 °C, 170 °C respectively.

[0110] The flame-retardant grade of the finally obtained fast-crystallizing flame-retardant polypropylene composite is 1.6 mm V2; the shrinkage rate change of the fast-crystallizing flame-retardant polypropylene composite is 0.03% from 12 to 24 h after injection molding, and 0.02% from 24 to 48 h.

[0111] Example 4

[0112] A preparation method of a fast-crystallizing flame-retardant polypropylene composite, the specific steps are as follows:

[0113] (1) Preparation of raw materials:

[0114] Polypropylene: Homopolypropylene B, with a melt index of 10 g / 10 min under the test conditions of 230 °C and 2.16 kg;

[0115] Flame retardant;

[0116] Filled mineral: Talc powder;

[0117] Nucleating agent: A mixture of NA-11 and HPN-68L with a weight ratio of 1:1;

[0118] Processing aid: A mixture of an antioxidant and dispersant SG-200A in a weight ratio of 1:1, where the antioxidant is a mixture of antioxidant 168 and antioxidant 1010 in a weight ratio of 1:2;

[0119] (2) By weight, 93 parts of polypropylene, 2 parts of flame retardant, 5 parts of filled mineral, 0.3 part of nucleating agent, and 0.4 part of processing aid are mixed evenly in a high-speed mixer at 300 rpm for 13 min, and then added to a twin-screw extruder for extrusion molding to obtain a fast-crystallizing flame-retardant polypropylene masterbatch;

[0120] Among them, the temperatures of each zone of the twin-screw extruder are 160 °C, 160 °C, 170 °C, 170 °C, 170 °C, 170 °C, 170 °C, 170 °C, 170 °C respectively;

[0121] (3) The fast-crystallizing flame-retardant polypropylene masterbatch obtained in step (2) is mixed evenly in a high-speed mixer at 300 rpm for 10 min, and then added to a twin-screw extruder for secondary extrusion molding to obtain a fast-crystallizing flame-retardant polypropylene composite;

[0122] Among them, the temperatures of each zone of the twin-screw extruder are 160 °C, 160 °C, 170 °C, 170 °C, 170 °C, 170 °C, 170 °C, 170 °C, 170 °C respectively.

[0123] The flame-retardant grade of the finally obtained fast-crystallizing flame-retardant polypropylene composite is 1.6 mm V2; the shrinkage rate change of the fast-crystallizing flame-retardant polypropylene composite is 0.01% from 12 to 24 h after injection molding, and the shrinkage rate change is 0.01% from 24 to 48 h.

[0124] Example 5

[0125] A preparation method of a fast-crystallizing flame-retardant polypropylene composite, the specific steps are as follows:

[0126] (1) Preparation of raw materials:

[0127] Polypropylene: Homopolypropylene C, with a melt index of 23 g / 10 min under the test conditions of 230 °C and 2.16 kg;

[0128] Flame retardant;

[0129] Filled mineral: Talc powder;

[0130] Nucleating agent: A mixture of NA-11 and HPN-68L in a weight ratio of 1:1;

[0131] Processing aid: A mixture of an antioxidant and dispersant SG-200A in a weight ratio of 1:1, where the antioxidant is a mixture of antioxidant 168 and antioxidant 1010 in a weight ratio of 1:1;

[0132] (2) By weight, 89 parts of polypropylene, 3 parts of flame retardant, 8 parts of filled mineral, 0.3 part of nucleating agent, and 0.6 part of processing aid are mixed evenly in a high-speed mixer at 300 rpm for 10 min, and then added to a twin-screw extruder for extrusion molding to obtain a fast-crystallizing flame-retardant polypropylene masterbatch;

[0133] Among them, the temperatures of each zone of the twin-screw extruder are 160 °C, 160 °C, 170 °C, 170 °C, 170 °C, 170 °C, 170 °C, 170 °C, 170 °C respectively;

[0134] (3) The fast-crystallizing flame-retardant polypropylene masterbatch obtained in step (2) is mixed evenly in a high-speed mixer at 300 rpm for 15 min, and then added to a twin-screw extruder for secondary extrusion molding to obtain a fast-crystallizing flame-retardant polypropylene composite;

[0135] Among them, the temperatures of each zone of the twin-screw extruder are 160 °C, 160 °C, 170 °C, 170 °C, 170 °C, 170 °C, 170 °C, 170 °C, 170 °C respectively.

[0136] The flame-retardant grade of the finally obtained fast-crystallizing flame-retardant polypropylene composite is 1.6 mm V2; the shrinkage rate change of the fast-crystallizing flame-retardant polypropylene composite is 0.03% from 12 to 24 h after injection molding, and 0.02% from 24 to 48 h.

[0137] Example 6

[0138] A preparation method of a fast-crystallizing flame-retardant polypropylene composite, the specific steps are as follows:

[0139] (1) Preparation of raw materials:

[0140] Polypropylene: Homopolypropylene D, with a melt index of 60 g / 10 min under test conditions of 230 °C and 2.16 kg;

[0141] Flame retardant;

[0142] Filled mineral: Talc powder;

[0143] Nucleating agent: A mixture of NA-11 and HPN-68L in a weight ratio of 1:1;

[0144] Processing aids: A mixture of an antioxidant and dispersant SG-200A in a weight ratio of 1:2, where the antioxidant is a mixture of antioxidant 168 and antioxidant 1010 in a weight ratio of 1:1;

[0145] (2) By weight, 85 parts of polypropylene, 5 parts of flame retardant, 10 parts of filled mineral, 0.6 part of nucleating agent, and 0.8 part of processing aids are mixed evenly in a high-speed mixer at a speed of 300 rpm for 15 min, and then added to a twin-screw extruder for extrusion molding to obtain a fast-crystallizing flame-retardant polypropylene masterbatch;

[0146] Among them, the temperatures of each zone of the twin-screw extruder are 160 °C, 160 °C, 170 °C, 170 °C, 170 °C, 170 °C, 170 °C, 170 °C, 170 °C respectively;

[0147] (3) The fast-crystallizing flame-retardant polypropylene masterbatch obtained in step (2) is mixed evenly in a high-speed mixer at a speed of 300 rpm for 12 min, and then added to a twin-screw extruder for secondary extrusion molding to obtain a fast-crystallizing flame-retardant polypropylene composite;

[0148] Among them, the temperatures of each zone of the twin-screw extruder are 160 °C, 160 °C, 170 °C, 170 °C, 170 °C, 170 °C, 170 °C, 170 °C, 170 °C respectively.

[0149] The flame-retardant grade of the finally obtained fast-crystallizing flame-retardant polypropylene composite is 1.6 mm V2; the shrinkage rate change of the fast-crystallizing flame-retardant polypropylene composite is 0.02% from 12 to 24 h after injection molding, and 0.02% from 24 to 48 h.

Claims

1. A fast-crystallizing flame-retardant polypropylene composite material, characterized in that Comprising the following components in parts by weight: The filler mineral is talc powder; The nucleating agent is a mixture of NA-11 and HPN-68L; The flame retardant rating of the fast-crystallizing flame retardant polypropylene composite is 1.6 mm V2; The shrinkage rate change of the fast-crystallizing flame retardant polypropylene composite within 12 - 24 h after injection molding does not exceed 0.03%, and the shrinkage rate change within 24 - 48 h does not exceed 0.02%; The weight ratio of NA-11 to HPN-68L is 1:1; The polypropylene is homopolypropylene; The preparation steps of the fast-crystallizing flame retardant polypropylene composite are as follows: (1) After uniformly mixing polypropylene, flame retardant, filler mineral, nucleating agent, and processing aids, add them to a twin-screw extruder for extrusion molding to obtain a fast-crystallizing flame retardant polypropylene masterbatch; (2) After fully mixing the fast-crystallizing flame retardant polypropylene masterbatch obtained in step (1), add it to a twin-screw extruder for secondary extrusion molding to obtain a fast-crystallizing flame retardant polypropylene composite.

2. The fast-crystallizing flame-retardant polypropylene composite material according to claim 1, wherein The melt index of the homopolypropylene under the test conditions of 230 °C and 2.16 kg is 1 - 60 g / 10 min.

3. A rapid crystallization flame retardant polypropylene composite according to claim 1, characterized in that, The processing aids are antioxidant and dispersant.

4. A fast-crystallizing flame-retardant polypropylene composite according to claim 1, characterized in that, The antioxidant is antioxidant 168 and / or antioxidant 1010, and the dispersant is SG-200A.

5. The preparation method of a rapid crystallization flame-retardant polypropylene composite material according to any one of claims 1 to 4, characterized in that Including the following steps: (1) After uniformly mixing polypropylene, flame retardant, filler mineral, nucleating agent, and processing aids, add them to a twin-screw extruder for extrusion molding to obtain a fast-crystallizing flame retardant polypropylene masterbatch; (2) After fully mixing the fast-crystallizing flame retardant polypropylene masterbatch obtained in step (1), add it to a twin-screw extruder for secondary extrusion molding to obtain a fast-crystallizing flame retardant polypropylene composite.

6. The preparation method of a fast-crystallizing flame-retardant polypropylene composite according to claim 5, characterized in that, In steps (1) and (2), the mixing is carried out using a high-speed mixer, and the mixing time is 10 - 15 min; the rotation speed of the high-speed mixer is 300 rpm.

7. The preparation method of a fast-crystallizing flame-retardant polypropylene composite according to claim 5, characterized in that, In steps (1) and (2), the temperature range of each zone of the twin-screw extruder is 160 - 170 °C.

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