Metal organic framework / piperazine zinc pyrophosphate flame retardant, flame retardant masterbatch, and use thereof

Abstract

The invention belongs to the technical field of flame retardancy, and discloses a metal organic framework / piperazine zinc pyrophosphate flame retardant, comprising UIO-66 and piperazine zinc pyrophosphate; the mass ratio of UIO-66 to piperazine zinc pyrophosphate is 5:10-20. The flame retardant adopts UIO-66 and piperazine zinc pyrophosphate, and when the two are added to a base material, the dispersion performance of the piperazine zinc pyrophosphate can be improved and the agglomeration performance can be reduced. At the same time, the invention also provides a flame retardant masterbatch and application.

Description

Technical Field

[0001] The invention belongs to the technical field of flame retardancy, and in particular relates to a metal organic framework / piperazine zinc pyrophosphate flame retardant, a flame retardant masterbatch, and uses. Background Art

[0002] Piperazine pyrophosphate combines flame-retardant elements such as P, N, and C, acting as a carbon, gas, and acid source. It also exhibits exceptionally high light and thermal stability, with a 5% decomposition temperature exceeding 300°C, making it suitable for the processing temperatures of most resins. It not only flame-retards PP, but also exhibits excellent flame-retardant properties for PE, ABS, EP, and PU, making it a halogen-free flame retardant with great market potential.

[0003] CN112778237A discloses a method for synthesizing piperazine pyrophosphate metal salts, which is used to prepare piperazine pyrophosphate metal salts, and is used to solve the problem that piperazine pyrophosphate easily absorbs moisture and aggregates, and that incomplete dehydration leads to foaming during processing.

[0004] However, during the experiment, we found that piperazine pyrophosphate metal salts are also easy to agglomerate when dry. For example, "Research Progress on Synthesis and Application of Piperazine Phosphate Flame Retardants" Engineering Plastics Applications, September 2020, written by Jin Feng et al., pointed out that there is a large polarity difference between piperazine phosphate and the polymer matrix, and there is a large charge interaction between piperazine phosphate powders, which are easy to agglomerate, resulting in poor dispersion of piperazine phosphate in the polymer.

[0005] At the same time, we also found that piperazine pyrophosphate does not show obvious agglomeration when applied to a polymer matrix in a dry state.

[0006] That is to say, both piperazine pyrophosphate and piperazine pyrophosphate metal salts will agglomerate, but the former agglomerates under the condition of absorbing water, while the latter agglomerates in the polymer matrix.

[0007] The technical problem solved in this case is: how to reduce the agglomeration of piperazine pyrophosphate metal salt in a polymer matrix. Summary of the Invention

[0008] In view of the shortcomings of the existing technology, the purpose of the present invention is to provide a metal organic framework / piperazine zinc pyrophosphate flame retardant. The flame retardant uses UIO-66 and piperazine zinc pyrophosphate. When both are added to the base material, the dispersion performance of piperazine zinc pyrophosphate can be improved and the agglomeration performance can be reduced.

[0009] At the same time, the present invention also provides flame retardant masterbatch and application.

[0010] To achieve the purpose of the invention, the present invention adopts the following technical solution: a metal organic framework / piperazine zinc pyrophosphate flame retardant, including UIO-66 and piperazine zinc pyrophosphate; the mass ratio of UIO-66 to piperazine zinc pyrophosphate is 5:10-20.

[0011] In the above flame retardant, the mass ratio of UIO-66 to zinc piperazine pyrophosphate is 5:12-18.

[0012] At the same time, the present invention also discloses a flame retardant masterbatch containing the flame retardant as described above.

[0013] In the flame retardant masterbatch, the flame retardant masterbatch contains 30-50 wt% of flame retardant.

[0014] The flame retardant masterbatch further comprises 0.1-0.5 wt% of a dispersant.

[0015] In the flame retardant masterbatch, the dispersant is sodium stearate, magnesium stearate or calcium stearate.

[0016] In the above-mentioned flame retardant masterbatch, the base material in the flame retardant masterbatch is PA6, PA66 or PA612.

[0017] In addition, the present invention also discloses the use of UIO-66 to improve the dispersibility of zinc piperazine pyrophosphate in a base material.

[0018] Preferably, the base material is PA6, PA66 or PA612.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] The present invention adopts UIO-66 and zinc piperazine pyrophosphate to be added to the base material, which can improve the dispersion performance of zinc piperazine pyrophosphate and reduce the agglomeration performance;

[0021] After testing, it was found that using approximately 5-7wt% of zinc pyrophosphate and matching UIO-66 in the PA6 substrate can achieve the flame retardant performance of zinc pyrophosphate alone (the content in the substrate is 35wt%). In addition, due to the reduced dosage of zinc pyrophosphate, the structural strength of the PA6 material is also significantly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is the XPS spectrum of UiO-66. DETAILED DESCRIPTION

[0023] The technical solution of the present invention is further described below by way of specific embodiments. It should be understood by those skilled in the art that the embodiments are merely to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0024] Part 1

[0025] Synthesis of UiO-66

[0026] The synthesis process of UiO-66 is as follows: First, 1.98g ZrCl4 dissolves 1.76g TPA in 150mL anhydrous N, N-dimethylformamide (DMF), ultrasonicates for 20min, and then adds 4mL acetic acid for ultrasonication for 10min. The mixed solution is transferred to a blue bottle and placed in a 120℃ electric blast drying chamber. After removing the solvent for 36h, the powder is cooled to room temperature. Then centrifuge at 6000r / min for 15min, filter the white precipitate, and wash it 3 times with DMF and ethanol. Finally, the white product is dried in a constant temperature vacuum drying tank at 85℃ for 36h to obtain UiO-66. The XPS spectrum of UiO-66 is shown as follows Figure 1 As shown. Figure 1 In the figure, the meaning of each figure is: (a) full spectrum; (b) C 1s; (c) O 1s; (d) Zr 3d.

[0027] Synthesis of Zinc Piperazine Pyrophosphate

[0028] Prepared by the method of Example 3 of CN112778237A.

[0029] Part 2

[0030] Preparation of flame retardant masterbatch

[0031] Example 1

[0032] The flame retardant masterbatch is prepared by a twin-screw extrusion method. Specifically, the method is as follows:

[0033] Step 1: drying zinc piperazine pyrophosphate, UiO-66, and PA6; the weight ratio of UiO-66, zinc piperazine pyrophosphate, PA6, and sodium stearate is 12.5:37:50:0.5;

[0034] Step 2: Add zinc piperazine pyrophosphate, UiO-66, PA6, and sodium stearate into a twin-screw extruder, and set the temperatures of each zone of the twin-screw extruder to 200°C, 230°C, 240°C, 250°C, 255°C, 255°C, 250°C, and 250°C, and the screw speed to 15-20 r / min;

[0035] Step 3: Cut the extruded material into granules to obtain masterbatch.

[0036] Example 2

[0037] The method is substantially the same as Example 1, except that the weight ratio of UiO-66, zinc piperazine pyrophosphate, PA6, and sodium stearate is 10.5:40:50:0.5.

[0038] Example 3

[0039] The method is substantially the same as Example 1, except that the weight ratio of UiO-66, zinc piperazine pyrophosphate, PA6, and sodium stearate is 17:32.5:50:0.5.

[0040] Example 4

[0041] The method is substantially the same as Example 1, except that the weight ratio of UiO-66, zinc piperazine pyrophosphate, PA6, and sodium stearate is 10:30:59.5:0.5.

[0042] Example 5

[0043] The method is substantially the same as Example 1, except that the weight ratio of UiO-66, zinc piperazine pyrophosphate, PA6, and sodium stearate is 10:20:69.5:0.5.

[0044] Comparative Example 1

[0045] The method is substantially the same as Example 1, except that the raw materials are piperazine pyrophosphate, UiO-66, PA6, and sodium stearate;

[0046] The weight ratio of UiO-66, piperazine pyrophosphate, PA6, and sodium stearate is 12.5:37:50:0.5.

[0047] Part 3

[0048] Preparation of PA6 sheets

[0049] PA6 and the flame retardant masterbatch were heated and melted, and injection molded to obtain a PA6 sheet with a specification of 12.7 cm*1.27 cm*0.32 cm; the formula is shown in Table 1 below;

[0050] Table 1 Recipe

[0051]

[0052]

[0053] In addition, plate 7 and plate 8 are prepared by the following method:

[0054] Plate 7

[0055] PA6 and zinc piperazine pyrophosphate (after drying) are heated, melted, and mixed, and injection molded to obtain a PA6 sheet with a specification of 12.7 cm*1.27 cm*0.32 cm; the weight ratio of PA6 to zinc piperazine pyrophosphate is 65:35.

[0056] Plate 8

[0057] PA6 and piperazine pyrophosphate (after drying) are heated, melted, and mixed, and injection molded to obtain a PA6 sheet with a specification of 12.7 cm*1.27 cm*0.32 cm; the weight ratio of PA6 to piperazine pyrophosphate is 65:35.

[0058] Performance Testing

[0059] Test item 1: physical properties of the board;

[0060] Test Item 2: Flame retardant properties of the board, including vertical burning test and LOI test;

[0061] The test results are shown in Tables 1 and 2 below;

[0062] Table 1 Physical properties of the board

[0063] sample Tensile strength (MPa) Elongation at break (%) Notched impact strength (kJ / m2) PA6 68.46 41.2 250.8 Plate 1 67.56 33.65 185.32 Plate 2 65.54 32.96 178.65 Plate 3 58.59 31.24 160.58 Plate 4 70.58 30.52 147.79 Plate 5 50.26 18.56 192.8 Plate 6 56.20 25.65 158.97 Plate 7 50.66 19.05 191.89 Plate 8 58.53 31.59 161.57

[0064] Table 2 Flame retardant properties of the board

[0065]

[0066]

[0067] Result analysis:

[0068] 1. From the perspective of the physical properties of the panels, the structural strength of panels 1 to 5 is weaker than that of PA6. This is expected because the addition of flame retardant materials will, in most cases, reduce the strength of the panels.

[0069] 2. Compared with Plate 1, Plate 6 has significantly lower elongation at break and notched impact strength. Compared with Plate 6, Plate 8 has slightly lower physical strength. The possible reasons are: referring to Plate 8 and Plate 1, piperazine pyrophosphate is used as a component of the masterbatch. Since it cannot be absolutely dry, it has slight agglomeration, which makes it unable to achieve the optimal dispersion state in the matrix, thereby causing a certain degree of reduction in physical strength. By comparing Plate 6 and Plate 8, it can be inferred that UiO-66 does not improve the dispersibility of piperazine pyrophosphate in a system containing piperazine pyrophosphate, resulting in a further reduction in physical strength. In Plate 1, the best dispersion is achieved by blending UiO-66 and zinc piperazine pyrophosphate. By pre-preparing it into a masterbatch, when the masterbatch is dispersed into the matrix, the zinc piperazine pyrophosphate can be better dispersed, so the weakening of the structural strength is relatively low.

[0070] 3. It can be seen from Plate 7 and Plate 8 that the agglomeration performance of zinc piperazine pyrophosphate is more significant in the PA6 matrix, while it can be seen from Plate 7 and Plate 1 that the physical properties of zinc piperazine pyrophosphate are significantly improved after adding a certain amount of UiO-66.

[0071] 4. From the perspective of flame retardancy, there is no trend difference between sheets 1 to 8. There is one case worth noting: sheet 4 shows the best flame retardancy. Whether from the perspective of the amount of zinc piperazine pyrophosphate or the amount of flame retardant masterbatch, it is not used the most or the least. It shows excellent flame retardancy. We speculate that this may be related to the material ratio in the masterbatch and the amount of masterbatch used in the sheet. Specifically: the amount of UiO-66 in the masterbatch should be between 10 and 12.5wt%, the amount of zinc piperazine pyrophosphate should be between 30 and 40wt%, and the amount of masterbatch in the sheet should not exceed 20wt%.

[0072] In actual applications, the comprehensive performance cannot be determined solely by flame retardant properties. After comprehensive analysis, we believe that Plate 1 and Plate 2 represent the best material usage choices.

Claims

1. A metal organic framework / piperazine zinc pyrophosphate flame retardant, characterized in that: The invention comprises UIO-66 and zinc piperazine pyrophosphate; the mass ratio of the UIO-66 to the zinc piperazine pyrophosphate is 5:10-20.

2. The flame retardant according to claim 1, characterized in that The mass ratio of UIO-66 to zinc piperazine pyrophosphate is 5:12-18.

3. A flame retardant masterbatch, characterized in that: Contains the flame retardant as claimed in claim 1 or 2.

4. The flame retardant masterbatch according to claim 3, characterized in that: The flame retardant masterbatch contains 30-50wt% of flame retardant.

5. The flame retardant masterbatch according to claim 3, characterized in that: Also included is 0.1-0.5 wt% of a dispersant.

6. The flame retardant masterbatch according to claim 3, characterized in that: The dispersant is sodium stearate, magnesium stearate or calcium stearate.

7. The flame retardant masterbatch according to claim 3, characterized in that: The base material in the flame retardant masterbatch is PA6, PA66 or PA612.

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