Polypropylene beta crystal form composite nucleating agent, and preparation method and application thereof

Abstract

The application discloses a polypropylene beta crystal composite nucleating agent, a preparation method and application thereof, and belongs to the technical field of polypropylene beta crystal composite nucleating agents. The composite nucleating agent comprises a main nucleating agent and an auxiliary nucleating agent; the main nucleating agent is zinc adipate; and the auxiliary nucleating agent is at least one of metal heptanedioate, metal tetrahydrophthalate or TMB-5. The composite nucleating agent can greatly improve the relative content of beta crystals in polypropylene, the relative content of beta crystals is greater than 90% as determined by an X-ray diffraction method, the polypropylene has excellent processing performance, and the application range of the polypropylene is greatly expanded.

Description

Technical Field

[0001] This invention belongs to the field of nucleating agent technology, specifically relating to a polypropylene β-crystal composite nucleating agent, its preparation method, and its application. Background Technology

[0002] Polypropylene (PP) is a thermoplastic semi-crystalline polymer prepared from propylene monomers through an addition polymerization reaction. During crystallization, PP can form five crystalline forms: α, β, γ, δ, and pseudo-hexagonal. Monoclinic α-crystalline PP is the easiest to form naturally during processing, exhibiting high stiffness and good transparency. γ, δ, and pseudo-hexagonal crystalline PP are rarely studied due to their demanding formation conditions and low practical value. Hexagonal β-crystalline PP, on the other hand, is gaining increasing attention due to its higher toughness, impact strength, and heat distortion temperature. Increasing the relative content of β-crystals in PP products is of great significance for expanding the application range of PP. Efficient β-crystalline induced crystallization technology has also been a research hotspot in the scientific research field. Currently, β-nucleating agent-induced crystallization is recognized as the most convenient and efficient method for inducing the formation of β-PP.

[0003] Based on their chemical composition, β-nucleating agents can be divided into inorganic and organic nucleating agents. Inorganic β-nucleating agents include some inorganic salts, such as CaCO3. Although inorganic nucleating agents are readily available and inexpensive, they generally have poor compatibility with polypropylene, requiring large amounts to induce β-PP formation, which greatly limits their application. In the 1960s, Leugering et al. first reported a fused-ring organic nucleating agent that could induce β-PP formation: γ-quinacridone (E3B). Subsequently, researchers discovered that various fused-ring compounds, such as thiodiphenylamine, 2-mercaptobenzimidazole, triphenyldithiazide, anthracene gold, and indigo ash, also possess the ability to induce β-PP formation. However, fused-ring organic nucleating agents have not been widely used because they easily cause staining of polypropylene products and have low nucleation efficiency. With the continuous development of synthetic processing technology in recent years, some amide compounds, carboxylates, rare earth compounds, and polymers have been found to have the ability to induce polypropylene to form a β-crystal form. However, most β-crystal nucleating agents still suffer from problems such as high production costs, poor compatibility with polypropylene matrix, low nucleation efficiency, and poor stability. Summary of the Invention

[0004] The purpose of this invention is to provide a polypropylene β-crystal composite nucleating agent, its preparation method, and its application, which solves the problems of poor compatibility and high cost of polypropylene β-crystal nucleating agents with the matrix in the prior art. The composite nucleating agent of this invention is used to increase the β-crystal content of polypropylene and can induce polypropylene to produce a higher content of β-crystal.

[0005] The objective of this invention is achieved through the following technical solution:

[0006] A composite nucleating agent comprising a primary nucleating agent and an auxiliary nucleating agent;

[0007] The primary nucleating agent is zinc adipate, and the secondary nucleating agent is at least one of heptanedioic acid metal salt, tetrahydrophthalic acid metal salt, or TMB-5.

[0008] According to the present invention, the mass ratio of the primary nucleating agent to the auxiliary nucleating agent is 60:40 to 90:10, preferably 80:20 to 90:10.

[0009] According to the present invention, the metal in the auxiliary nucleating agent may be selected from one or both of calcium and zinc. For example, the auxiliary nucleating agent is selected from calcium pimecronate, zinc pimecronate, calcium tetrahydrophthalate, zinc tetrahydrophthalate, or TMB-5.

[0010] According to the present invention, the nucleating agent is preferably TMB-5; TMB-5 is a commercially available additive.

[0011] The present invention also provides a method for preparing the above-mentioned composite nucleating agent, wherein the method comprises: weighing the main nucleating agent and the auxiliary nucleating agent in proportion, mixing them evenly, and obtaining the composite nucleating agent.

[0012] Preferably, the main nucleating agent and the auxiliary nucleating agent are weighed in proportion, placed in a mortar, and manually ground until fully mixed to obtain the composite nucleating agent.

[0013] The present invention also provides the application of the above-mentioned composite nucleating agent in polypropylene.

[0014] The present invention also provides a modified polypropylene, wherein the modified polypropylene comprises:

[0015] 100 parts by weight of polypropylene

[0016] Antioxidant 0.01-0.2 parts by weight,

[0017] The above-mentioned composite nucleating agent is used in amounts of 0.01 to 0.35 parts by mass.

[0018] According to the present invention, the polypropylene may be homopolymer polypropylene or copolymer polypropylene, preferably homopolymer polypropylene, and further, the melt index of the polypropylene is 3 to 100 g / 10 min.

[0019] According to the present invention, the antioxidant is at least one of hindered phenolic antioxidants, amine antioxidants, and phosphorus antioxidants, preferably a hindered phenolic antioxidant, and more preferably one or more of antioxidant 1010, antioxidant 1076, antioxidant B900, antioxidant 264, antioxidant 168, and antioxidant 2264.

[0020] According to the present invention, the composite nucleating agent is preferably 0.02 to 0.3 parts by mass, more preferably 0.1 to 0.3 parts by mass.

[0021] This invention also provides a method for preparing modified polypropylene, the method comprising the following steps:

[0022] (1) Add polypropylene, the above-mentioned composite nucleating agent and antioxidant to a high-speed mixer and mix evenly;

[0023] (2) The above mixture is granulated by a twin-screw extruder to obtain modified polypropylene.

[0024] According to the present invention, the temperature of the twin-screw extruder is 160–220°C, preferably 175–200°C; the mixing time is 1–15 min, preferably 5–10 min.

[0025] According to the present invention, the composite nucleating agent can make the relative content of β crystals in polypropylene reach more than 90%.

[0026] The beneficial effects of this invention are:

[0027] 1. The composite nucleating agent of the present invention can greatly increase the relative content of β crystals in polypropylene. The relative content of β crystals is greater than 90% as determined by X-ray diffraction. It has excellent processing performance and greatly expands the application range of polypropylene.

[0028] 2. The price of auxiliary nucleating agents in the prior art is very high. The present invention uses a main nucleating agent, which reduces the content of auxiliary nucleating agents in the composite nucleating agent, thereby reducing the preparation cost of the composite nucleating agent, simplifying the process, and enabling large-scale industrial production. Detailed Implementation

[0029] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. It should be understood that the following embodiments are merely illustrative and explanatory of the present invention, and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are covered within the scope of protection intended by the present invention.

[0030] Unless otherwise stated, the raw materials and reagents used in the following examples are commercially available products or can be prepared by known methods.

[0031] The primary nucleating agent and auxiliary nucleating agent used in the following examples can be prepared by methods known in the art.

[0032] The materials involved in the following embodiments are as follows:

[0033] Homopolymer PP powder with an average particle size of <0.06mm and a melt flow index of 9g / 10min.

[0034] The performance tests involved in the following embodiments are as follows:

[0035] The granules were pressed into 1mm thick sheets using an XH-406 tablet press at 200℃ and 15MPa pressure. After natural cooling, the crystal form of the samples was determined using an Empyrean X-ray diffractometer from Panaco (Netherlands). The relative content K of β crystals in polypropylene was determined. β Calculated according to the Turner-Jones formula:

[0036]

[0037] Where H β (300) is the intensity of the (300) diffraction peak in the β-crystal form appearing in the WAXD diffraction spectrum, H α1 (110), H α2 (040), H α3 (130) represents the intensity of the three stronger diffraction peaks.

[0038] Example 1

[0039] 100 parts of homopolymer polypropylene, 0.1 parts of composite nucleating agent (composed of zinc adipate and calcium pimecroate in a 9:1 mass ratio), and 0.2 parts of antioxidant (composed of antioxidant 1010 and antioxidant 168 in a 1:1 mass ratio) were added to a high-speed mixer and mixed uniformly for 10 minutes. The mixture was then extruded and granulated using a twin-screw extruder at 200°C, and finally tableted. The Kc of the β-crystals in the polypropylene was measured. β The value is 91.8%.

[0040] Example 2

[0041] 100 parts of homopolymer polypropylene, 0.1 parts of composite nucleating agent (composed of zinc adipic acid and calcium pimecrolate in a mass ratio of 8:2), and 0.2 parts of antioxidant (antioxidant 1010 and antioxidant 168 in a mass ratio of 1:1) were added to a high-speed mixer and mixed evenly for 10 minutes. Then, the mixture was extruded and granulated at 200°C using a twin-screw extruder, and tableted. The relative content K of the β-crystal form in the sample was measured. β The value is 94.3%.

[0042] Example 3

[0043] 100 parts of homopolymer polypropylene, 0.1 parts of composite nucleating agent (composed of zinc adipate and calcium tetrahydrophthalate in a 9:1 mass ratio), and 0.2 parts of antioxidant (composed of antioxidant 1010 and antioxidant 168 in a 1:1 mass ratio) were added to a high-speed mixer and mixed uniformly for 10 minutes. Then, the mixture was extruded and granulated at 200°C using a twin-screw extruder, and tableted. The relative content K of the β-crystal form in the sample was measured. β The value is 91.7%.

[0044] Example 4

[0045] 100 parts of homopolymer polypropylene, 0.1 parts of composite nucleating agent (composed of zinc adipate and calcium tetrahydrophthalate in a mass ratio of 8:2), and 0.2 parts of antioxidant (antioxidant 1010 and antioxidant 168 in a mass ratio of 1:1) were added to a high-speed mixer and mixed evenly for 10 minutes. Then, the mixture was extruded and granulated at 200°C using a twin-screw extruder, and then compressed into tablets. The relative content K of the β-crystal form in the sample was measured. β The value is 92.4%.

[0046] Example 5

[0047] 100 parts of homopolymer polypropylene, 0.1 parts of composite nucleating agent (composed of zinc adipic acid and TMB-5 in a 9:1 mass ratio), and 0.2 parts of antioxidant (composed of antioxidant 1010 and antioxidant 168 in a 1:1 mass ratio) were added to a high-speed mixer and mixed uniformly for 10 minutes. Then, the mixture was extruded and granulated at 200°C using a twin-screw extruder, and tableted. The relative content K of the β-crystal form in the sample was measured. β The value is 94.4%.

[0048] Example 6

[0049] 100 parts of homopolymer polypropylene, 0.1 parts of composite nucleating agent (composed of zinc adipic acid and TMB-5 in a mass ratio of 8:2), and 0.2 parts of antioxidant (composed of antioxidant 1010 and antioxidant 168 in a mass ratio of 1:1) were added to a high-speed mixer and mixed uniformly for 10 minutes. Then, the mixture was extruded and granulated at 200°C using a twin-screw extruder, and then compressed into tablets. The relative content K of the β-crystal form in the sample was measured. β The value is 91.8%.

[0050] Example 7

[0051] 100 parts of homopolymer polypropylene, 0.1 parts of composite nucleating agent (composed of zinc adipate and zinc pimecroate in a 9:1 mass ratio), and 0.2 parts of antioxidant (antioxidant 1010 and antioxidant 168 in a 1:1 mass ratio) were added to a high-speed mixer and mixed uniformly for 10 minutes. The mixture was then extruded and granulated using a twin-screw extruder at 200°C, and finally tableted. The Kc of the β-crystals in the polypropylene was measured.β The value is 90.6%.

[0052] Example 8

[0053] 100 parts of homopolymer polypropylene, 0.2 parts of composite nucleating agent (composed of zinc adipic acid and TMB-5 in a 9:1 mass ratio), and 0.2 parts of antioxidant (composed of antioxidant 1010 and antioxidant 168 in a 1:1 mass ratio) were added to a high-speed mixer and mixed uniformly for 10 minutes. Then, the mixture was extruded and granulated at 200°C using a twin-screw extruder, and tableted. The relative content K of the β-crystal form in the sample was measured. β The value is 95.8%.

[0054] Example 9

[0055] 100 parts of homopolymer polypropylene, 0.3 parts of composite nucleating agent (composed of zinc adipic acid and TMB-5 in a 9:1 mass ratio), and 0.2 parts of antioxidant (composed of antioxidant 1010 and antioxidant 168 in a 1:1 mass ratio) were added to a high-speed mixer and mixed uniformly for 10 minutes. Then, the mixture was extruded and granulated at 200°C using a twin-screw extruder, and tableted. The relative content K of the β-crystal form in the sample was measured. β The value is 94.7%.

[0056] Comparative Example 1

[0057] 100 parts of homopolymer polypropylene, 0.1 parts of zinc adipic acid, and 0.2 parts of antioxidant (antioxidant 1010 and antioxidant 168 are compounded in a 1:1 mass ratio) were added to a high-speed mixer and mixed evenly for 10 minutes. Then, the mixture was extruded and granulated using a twin-screw extruder at 200°C, and then compressed into tablets. The relative content K of the β-crystal form in the sample was measured. β The value is 83.7%.

[0058] Comparative Example 2

[0059] 100 parts of homopolymer polypropylene, 0.1 parts of calcium heptanate, and 0.2 parts of antioxidant (antioxidant 1010 and antioxidant 168 are compounded in a 1:1 mass ratio) were added to a high-speed mixer and mixed evenly for 10 minutes. Then, the mixture was extruded and granulated at 200°C using a twin-screw extruder, and then compressed into tablets. The relative content K of the β-crystal form in the sample was measured. β The value is 92.7%.

[0060] Comparative Example 3

[0061] 100 parts of homopolymer polypropylene, 0.1 parts of calcium tetrahydrophthalate, and 0.2 parts of antioxidant (antioxidant 1010 and antioxidant 168 are compounded in a 1:1 mass ratio) were added to a high-speed mixer and mixed evenly for 10 minutes. Then, the mixture was extruded and granulated using a twin-screw extruder at 200°C, and then compressed into tablets. The relative content K of the β-crystal form in the sample was measured. βThe value is 93.5%.

[0062] Comparative Example 4

[0063] 100 parts of homopolymer polypropylene, 0.1 parts of TMB-5, and 0.2 parts of antioxidant (antioxidant 1010 and antioxidant 168 are compounded in a 1:1 mass ratio) were added to a high-speed mixer and mixed evenly for 10 minutes. Then, the mixture was extruded and granulated at 200°C using a twin-screw extruder, and then compressed into tablets. The relative content K of the β-crystal form in the sample was measured. β The value is 94.5%.

[0064] Table 1. Relative content (K) of β-crystal form in polypropylene with added composite nucleating agent. β

[0065] Comparative Example 1 0.1 Zinc adipic acid / 10:0 83.7 Example 1 0.1 Zinc adipic acid Calcium pimecronate 9:1 91.8 Example 2 0.1 Zinc adipic acid Calcium pimecronate 8:2 94.3 Comparative Example 2 0.1 / Calcium pimecronate 0:10 92.7 Example 3 0.1 Zinc adipic acid Calcium tetrahydrophthalate 9:1 91.7 Example 4 0.1 Zinc adipic acid Calcium tetrahydrophthalate 8:2 92.4 Comparative Example 3 0.1 / Calcium tetrahydrophthalate 0:10 92.6 Example 5 0.1 Zinc adipic acid TMB-5 9:1 94.4 Example 6 0.1 Zinc adipic acid TMB-5 8:2 91.8 Comparative Example 4 0.1 / TMB-5 0:10 94.5 Example 7 0.1 Zinc adipic acid Zinc pimecrolate 9:1 90.6 Example 8 0.2 Zinc adipic acid TMB-5 9:1 95.8 Example 9 0.3 Zinc adipic acid TMB-5 9:1 94.7

[0066] As can be seen from Table 1, the addition of the nucleating agent can increase the relative content K of β crystals in polypropylene. β Compared to the other two auxiliary nucleating agents, TMB-5 can significantly increase the relative content of β crystals in polypropylene when added in smaller amounts. As can be seen from Examples 1-4 and Comparative Examples 2-3, with the increase of the proportion of auxiliary nucleating agent in the composite nucleating agent, the relative content K of β crystals in polypropylene increases. β When the ratio of primary to secondary nucleating agents is 8:2, K increases. β The relative content of β crystals in polypropylene with almost complete addition of auxiliary nucleating agent; as can be seen from Examples 5-6 and Comparative Example 4, when the auxiliary nucleating agent is less, i.e., the ratio of main to auxiliary nucleating agent is 9:1, the relative content K of β crystals in polypropylene is... β The relative content of β-crystals in polypropylene with all auxiliary nucleating agents added is comparable to that in polypropylene with calcium salt as the auxiliary nucleating agent compared to that with zinc salt. As can be seen from Examples 1 and 7, the relative content K of β-crystals in polypropylene with calcium salt as the auxiliary nucleating agent is higher than that with zinc salt. β High; as can be seen from Examples 5 and 8-9, with the increase of the amount of composite nucleating agent added, the relative content K of β crystals in polypropylene increases. β First increase, then decrease. Therefore, to reduce costs, we prefer to add a smaller amount of the auxiliary nucleating agent TMB-5.

[0067] The embodiments of the present invention have been described above by way of example. However, the scope of protection of the present invention is not limited to the above embodiments. Any modifications, equivalent substitutions, improvements, etc., made by those skilled in the art within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A composite nucleating agent, characterized in that, It includes primary nucleating agents and secondary nucleating agents; The primary nucleating agent is zinc adipate, and the auxiliary nucleating agent is at least one of heptanedioic acid metal salt, tetrahydrophthalic acid metal salt, or TMB-5. The mass ratio of the primary nucleating agent to the auxiliary nucleating agent is 60:40 to 90:10; The metal in the auxiliary nucleating agent is selected from one or both of calcium and zinc.

2. The composite nucleating agent according to claim 1, characterized in that, The auxiliary nucleating agent is selected from one of calcium pimecronate, zinc pimecronate, calcium tetrahydrophthalate, zinc tetrahydrophthalate, or TMB-5.

3. The method for preparing the composite nucleating agent according to claim 1 or 2, characterized in that, The method described is as follows: weigh the main nucleating agent and the auxiliary nucleating agent in proportion, mix them evenly, and prepare the composite nucleating agent.

4. The application of the composite nucleating agent according to claim 1 or 2 in polypropylene.

5. A modified polypropylene, characterized in that, The modified polypropylene includes: 100 parts by weight of polypropylene Antioxidant 0.01~0.2 parts by weight, The composite nucleating agent according to claim 1 or 2 is used in amounts of 0.01 to 0.35 parts by weight.

6. The modified polypropylene according to claim 5, characterized in that, The antioxidant is at least one of hindered phenolic antioxidants, amine antioxidants, and phosphorus antioxidants.

7. The modified polypropylene according to claim 6, characterized in that, The antioxidant is a hindered phenolic antioxidant.

8. The modified polypropylene according to claim 7, characterized in that, The hindered phenolic antioxidant is one or more of antioxidant 1010, antioxidant 1076, antioxidant B900, antioxidant 264, antioxidant 168, and antioxidant 2264.

9. The method for preparing modified polypropylene according to any one of claims 6-8, characterized in that, The method includes the following steps: (1) Add polypropylene, composite nucleating agent and antioxidant to a high-speed mixer and mix evenly; (2) The above mixture is granulated by a twin-screw extruder to obtain modified polypropylene.

10. The method according to claim 9, characterized in that, The temperature of the twin-screw extruder is 160~220℃; the mixing time is 1~15min.

11. The method according to claim 9, characterized in that, The composite nucleating agent can make the relative content of β crystals in polypropylene reach more than 90%.

Images