Halogen-free ablative polypropylene resin composition and use thereof

Abstract

The application provides a halogen-free ablative polypropylene resin composition and application thereof, which comprises 18-50 parts of polypropylene resin, 3-10 parts of piperazine flame retardant, 20-26 parts of nitrogen-phosphorus composite flame retardant, 0.2-1.8 parts of synergistic flame retardant and 12-28 parts of long glass fiber, wherein the mass percentage of silicon dioxide in the long glass fiber is greater than 60%. The halogen-free ablative polypropylene resin composition has excellent ablative resistance, heat insulation and flame retardant properties.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of materials for battery pack upper covers, and particularly relates to a halogen-free ablation-resistant polypropylene resin composition and application thereof. BACKGROUND

[0002] With the vigorous development of the new energy industry, the installed capacity of power batteries and energy storage batteries is breaking new highs. Among them, the materials for battery pack upper covers are mainly metals or thermosetting materials, and the scheme has the disadvantages of large proportion, low processing efficiency and environmental pollution. Thermoplastic materials are rapidly promoted and applied due to the advantages of light specific gravity and environmental protection.

[0003] The core requirement of a battery pack is to pass the GB / T31467.3-2015 fire resistance test, and it is required that no large amount of toxic and harmful gases are generated during the combustion process. Conventional polypropylene materials (PP) cannot meet the existing requirements, and a new generation of low-smoke, halogen-free, ablation-resistant and heat-insulating flame-retardant enhanced PP that meets the test requirements of customers will become the trend of technological development. In the prior art, a halogen-free piperazine flame retardant, long glass fiber and ceramic filler are compounded to have a certain ablation resistance, but after thinning, the material is not resistant to fire and has the problem of easy burning through.

[0004] Therefore, it is an urgent problem in the field to develop a polypropylene resin material that still has excellent ablation resistance, heat insulation and flame retardance after thinning. SUMMARY

[0005] In view of the deficiencies in the prior art, the purpose of the present application is to provide a halogen-free ablation-resistant polypropylene resin composition and application thereof. The halogen-free ablation-resistant polypropylene resin composition has excellent ablation resistance, heat insulation and flame retardance.

[0006] To achieve this purpose, the following technical solutions are used in the present application:

[0007] In a first aspect, the present application provides a halogen-free ablation-resistant polypropylene resin composition, which comprises, by weight, 18-50 parts of polypropylene resin, 3-10 parts of piperazine flame retardant, 20-26 parts of nitrogen-phosphorus composite flame retardant, 0.2-1.8 parts of synergistic flame retardant and 12-28 parts of long glass fiber; the mass percentage of silicon dioxide in the long glass fiber is >60%.

[0008] In the present application, the specific content of piperazine flame retardant and nitrogen-phosphorus composite flame retardant is compounded, which is beneficial to increase the thickness and density of carbon layer, improve the heat insulation performance; by adding a specific content of synergistic flame retardant, the heat insulation performance of the material is further improved; by adding specific long glass fiber, the skeleton strength can be enhanced, and the ablation resistance is improved; by compounding the long glass fiber with the specific flame retardant and the synergistic flame retardant, the halogen-free ablation-resistant polypropylene resin composition has excellent ablation resistance and heat insulation performance, and good flame retardant performance.

[0009] The 18-50 parts of polypropylene resin, for example, can be 18 parts, 20 parts, 22 parts, 24 parts, 26 parts, 28 parts, 30 parts, 32 parts, 34 parts, 36 parts, 38 parts, 40 parts, 42 parts, 44 parts, 46 parts, 48 parts, 50 parts, etc.

[0010] The 3-10 parts of piperazine flame retardant, for example, can be 3 parts, 3.2 parts, 3.4 parts, 3.6 parts, 3.8 parts, 4 parts, 4.2 parts, 4.4 parts, 4.6 parts, 4.8 parts, 5 parts, 5.2 parts, 5.5 parts, 5.8 parts, 6 parts, 6.2 parts, 6.5 parts, 6.8 parts, 7 parts, 7.2 parts, 7.5 parts, 7.8 parts, 8 parts, 8.2 parts, 8.5 parts, 8.8 parts, 9 parts, 9.2 parts, 9.5 parts, 9.8 parts, 10 parts, etc.

[0011] The 20-26 parts of nitrogen-phosphorus composite flame retardant, for example, can be 20 parts, 20.5 parts, 21 parts, 21.5 parts, 22 parts, 22.5 parts, 23 parts, 23.5 parts, 24 parts, 24.5 parts, 25 parts, 25.5 parts, 26 parts, etc.

[0012] The 0.2-1.8 parts of synergistic flame retardant, for example, can be 0.2 parts, 0.3 parts, 0.4 parts, 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts, 1 parts, 1.1 parts, 1.2 parts, 1.3 parts, 1.4 parts, 1.5 parts, 1.6 parts, 1.7 parts, 1.8 parts, etc.

[0013] The 12-28 parts of long glass fiber, for example, can be 12 parts, 13 parts, 14 parts, 15 parts, 16 parts, 17 parts, 18 parts, 19 parts, 20 parts, 21 parts, 22 parts, 23 parts, 24 parts, 25 parts, 26 parts, 27 parts, 28 parts, etc.

[0014] The mass percentage of silicon dioxide in the long glass fiber is >60%, for example, can be 61%, 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69%, 70%, etc.

[0015] In the present application, the silica content in the long glass fiber can be determined by using the conventional method in the prior art, such as according to the method of GB / T 1549-2008 fiber glass chemical analysis.

[0016] In the present application, the long glass fiber further comprises, in terms of mass percentage, 10-20% of alumina (for example, it can be 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, etc.), 5-15% of boron oxide (for example, it can be 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, 9.5%, 10%, 10.5%, 11%, 11.5%, 12%, 12.5%, 13%, 13.5%, 14%, 14.5%, 15%, etc.), 12-22% of calcium oxide (for example, it can be 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 22%, etc.), 2-8% of magnesium oxide (for example, it can be 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, etc.), and 0-0.5% of sodium oxide (for example, it can be 0%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, etc.).

[0017] Preferably, the polypropylene resin has a melt index of 10-32 g / 10 min, for example, it can be 10 g / 10 min, 12 g / 10 min, 14 g / 10 min, 16 g / 10 min, 18 g / 10 min, 20 g / 10 min, 22 g / 10 min, 24 g / 10 min, 26 g / 10 min, 28 g / 10 min, 30 g / 10 min, 32 g / 10 min, etc.

[0018] In the present application, the test conditions for the melt index of the polypropylene resin are 230°C and 2.16 kg.

[0019] Preferably, the piperazine flame retardant comprises any one or a combination of at least two of piperazine phosphate, piperazine pyrophosphate, or piperazine polyphosphate.

[0020] Preferably, the nitrogen-phosphorus composite flame retardant comprises melamine pyrophosphate and / or melamine polyphosphate.

[0021] Preferably, the mass ratio of the melamine pyrophosphate and the melamine polyphosphate is (0.3-3):1, wherein the specific value in (0.3-3) can be 0.3, 0.4, 0.5, 0.6, 0.8, 1, 1.2, 1.4, 1.6, 1.8, 2, 2.2, 2.4, 2.6, 2.8, 3, etc.; and further preferably (1-2.6):1.

[0022] Preferably, the synergistic flame retardant comprises any one or a combination of at least two of zinc oxide, zinc borate, glass powder or sepiolite.

[0023] Preferably, the synergistic flame retardant comprises at least two of zinc oxide, sepiolite and zinc borate, further preferably a combination of zinc oxide and zinc borate, or a combination of sepiolite and zinc borate.

[0024] Preferably, the mass ratio of zinc oxide and zinc borate, or the mass ratio of sepiolite and zinc borate is independently (0.5-4.2):1, wherein the specific value in (0.5-4.2) can be 0.5, 0.6, 0.8, 1, 1.2, 1.4, 1.6, 1.8, 2, 2.2, 2.4, 2.6, 2.8, 3, 3.2, 3.4, 3.6, 3.8, 4, 4.2, etc.; further preferably (1.2-4):1.

[0025] Preferably, the average retention length of the long glass fiber is >1mm, for example, 1, 1.05mm, 1.1mm, 1.15mm, 1.2mm, 1.25mm, 1.3mm, 1.35mm, 1.4mm, 1.45mm, 1.5mm, 1.55mm, 1.6mm, 1.65mm, 1.7mm, 1.75mm, 1.8mm, 1.85mm, 1.9mm, 1.95mm, 2mm, 2.1mm, 2.2mm, 2.3mm, 2.4mm, 2.5mm, 2.6mm, 2.7mm, 2.8mm, 2.9mm, 3mm, 3.2mm, 3.5mm, 3.8mm, 4mm, 4.2mm, 4.5mm, 4.8mm, 5mm, etc., further preferably 1.2-3mm.

[0026] In the present application, the factors affecting the average retention length of the long glass fiber include the type of long glass fiber (including the content of silicon dioxide) and injection molding conditions (such as injection molding pressure or back pressure).

[0027] Preferably, the mass percentage of silicon dioxide in the long glass fiber is 65-70%.

[0028] Preferably, the long glass fiber is added in the form of long glass fiber masterbatch.

[0029] In the present application, the long glass fiber masterbatch comprises resin and long glass fiber; the resin comprises polyolefin; the polyolefin comprises polypropylene.

[0030] Preferably, the long glass fiber in the long glass fiber master batch has a mass percentage of 40-60%, for example, 40%, 42%, 44%, 46%, 48%, 50%, 52%, 54%, 56%, 58%, 60%, etc.

[0031] Preferably, the halogen-free ablative polypropylene resin composition further comprises 1-5 parts of a compatibilizer, for example, 1 part, 2 parts, 3 parts, 4 parts, 5 parts, etc.

[0032] Preferably, the compatibilizer comprises polypropylene grafted maleic anhydride (PP-g-MAH) and / or polyolefin elastomer grafted maleic anhydride.

[0033] In the present application, the polyolefin elastomer grafted maleic anhydride comprises ethylene-octene copolymer grafted maleic anhydride (POE-g-MAH).

[0034] Preferably, the halogen-free ablative polypropylene resin composition further comprises 0.3-1.5 parts of other additives, for example, 0.3 parts, 0.4 parts, 0.5 parts, 0.6 parts, 0.8 parts, 1 part, 1.2 parts, 1.5 parts, etc.

[0035] Preferably, the other additives comprise an antioxidant and / or a lubricant.

[0036] In the present application, the antioxidant comprises at least one of, but is not limited to, tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid]pentaerythritol ester (antioxidant 1010), tris[2.4-di-tert-butylphenyl]phosphite (antioxidant 168), n-octadecyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (antioxidant 1076), 4,4'-bis(α,α-dimethylbenzyl) diphenylamine (antioxidant 445), N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexamethylenediamine (antioxidant 1098).

[0037] In the present application, the lubricant comprises at least one of, but is not limited to, ethylene bis-stearamide, erucamide, zinc stearate, or silicone oil.

[0038] In the present application, the halogen-free ablative polypropylene resin composition, after being made into a thin-walled product, still has excellent ablative resistance, solving the problem of conventional polypropylene composites not being resistant to fire and being easily burned through after being thinned.

[0039] In the present application, the thin-walled refers to a thickness of the product as low as 2 mm, for example, 0.2 mm, 0.4 mm, 0.6 mm, 0.8 mm, 1 mm, 1.2 mm, 1.5 mm, 1.8 mm, 2 mm, etc.

[0040] In a second aspect, the present application provides an article comprising the halogen-free ablative-resistant polypropylene resin composition of the first aspect, wherein the article comprises a battery pack upper cover.

[0041] The numerical ranges recited herein are inclusive of the endpoints and also include any other ranges that can be stated or inferred from the stated ranges.

[0042] Compared with the prior art, the present application has the following beneficial effects:

[0043] The halogen-free ablative-resistant polypropylene resin composition provided by the present application uses specific contents of piperazine flame retardant, nitrogen-phosphorus composite flame retardant, synergistic flame retardant, and specific long glass fiber compound, and the obtained composition is particularly suitable for preparing thin-walled polypropylene materials, and improves the burn-through resistance, heat insulation performance, and flame retardant performance of the thin-walled polypropylene materials. DETAILED DESCRIPTION

[0044] The technical solutions of the present application will be further described below through specific embodiments. Those skilled in the art should understand that the embodiments are only used to help understand the present application and should not be regarded as specific limitations on the present application.

[0045] The materials used in the present application are as follows:

[0046] Resin

[0047] PP-1: homopolymer polypropylene pellets, brand HP500N, CNOOC Shell.

[0048] PP-2: copolymer polypropylene pellets, brand EP548R, CNOOC Shell.

[0049] Long glass fiber masterbatch (the resin in the long glass fiber masterbatch is polypropylene)

[0050] GF-1: the mass percentage content of long glass fiber is 50%; the long glass fiber includes, in terms of mass percentage content: 62% silicon dioxide, 15% aluminum oxide, 6% boron oxide, 13% calcium oxide, 3.6% magnesium oxide, and 0.4% sodium oxide;

[0051] GF-2: the mass percentage content of long glass fiber is 50%; the long glass fiber includes, in terms of mass percentage content: 68% silicon dioxide, 11% aluminum oxide, 6.5% boron oxide, 12% calcium oxide, 2.2% magnesium oxide, and 0.3% sodium oxide;

[0052] GF-d1: the mass percentage content of long glass fiber is 50%; the long glass fiber includes, in terms of mass percentage content: 50% silicon dioxide, 16% aluminum oxide, 6.8% boron oxide, 21.5% calcium oxide, 5.5% magnesium oxide, and 0.2% sodium oxide;

[0053] Antioxidant: Antioxidant 1010, commercially available; Antioxidant 168, commercially available, mass ratio of 1:1.

[0054] Lubricant: Ethylene bis-stearamide EBS, commercially available;

[0055] Melamine pyrophosphate: purchased from Hubei Xinmingtai Chemical Co., Ltd;

[0056] Melamine polyphosphate: purchased from Wuhan Jixingyibang Biological Technology Co., Ltd;

[0057] Sepiolite: purchased from Yitian Mining Industry;

[0058] PP-g-MAH: Xingyuan Chemical, XYJ1210;

[0059] POE-g-MAH: Dow Chemical, AMPLIFY GR216;

[0060] Piperazine pyrophosphate, piperazine phosphate, triphenyl phosphate, zinc oxide, zinc borate can be purchased commercially.

[0061] Examples 1-14 and Comparative Examples 1-6 provide a halogen-free ablative polypropylene resin composition, the formulation of which is shown in Tables 1 and 2, in parts by weight, wherein " / " indicates that there is no such component in the formulation.

[0062] Table 1

[0063]

[0064]

[0065] Table 2

[0066]

[0067] Performance test

[0068] The halogen-free ablative polypropylene resin composition provided by Examples 1-14 and Comparative Examples 1-6, which is suitable for thin-walled injection molding, is injection molded into a polypropylene resin material with a thickness of 1.5 mm, and its related properties are tested; the specific process of thin-walled injection molding includes: injection molding temperature 210℃, mold temperature 30℃, back pressure 0.

[0069] (1) Flame retardant performance: reference UL 94, 1.5mm vertical burning of flame-retardant sample;

[0070] (2) Average fiber retention length: 1.5mm square plate injection molded, ash tested at 800℃ for 2h, and then secondary microscope test of glass fiber average retention length;

[0071] (3) Burn-through resistance: 1000℃ flame, continuously burning 1.5mm square plate for 10min. Observe whether the square plate is burned through;

[0072] (4) Heat insulation performance: 1000℃ flame, continuously burning 1.5mm square plate, at the same time, test the temperature of the back of the square plate (the other side away from the flame), the smaller the temperature, the better the heat insulation performance.

[0073] The specific test results are shown in Table 3.

[0074] Table 3

[0075]

[0076] It can be seen from Table 3 that the halogen-free ablation-resistant polypropylene resin composition provided by the application is compounded by using piperazine flame retardant, nitrogen-phosphorus composite flame retardant, synergistic flame retardant and specific long glass fiber with specific content, and the obtained composition is especially suitable for preparing thin-walled polypropylene material, and improves the burn-through resistance, heat insulation performance and flame retardant performance of the thin-walled polypropylene material; in the application, the polypropylene material including the halogen-free ablation-resistant polypropylene resin composition has a V-0 level of flame retardant grade at a relatively thin thickness (1.5mm), a long average fiber retention length, good burn-through resistance, a back temperature rise of not higher than 255℃ and good heat insulation effect.

[0077] The above specific embodiments further specifically describe the purpose, technical solutions and beneficial effects of the application, and it should be understood that the above description is only for specific embodiments of the application and is not used to limit the application, and any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the application should be included in the protection scope of the application.

Claims

1. A halogen-free, ablation-resistant polypropylene resin composition, characterized in that, By weight, the halogen-free ablation-resistant polypropylene resin composition comprises 18-50 parts polypropylene resin, 3-10 parts piperazine flame retardant, 20-26 parts nitrogen-phosphorus composite flame retardant, 0.2-1.8 parts synergistic flame retardant and 12-28 parts long glass fiber. The long glass fiber contains more than 60% silica by mass.

2. The halogen-free, ablation-resistant polypropylene resin composition according to claim 1, characterized in that, The melt index of the polypropylene resin is 10~32 g / 10min, and the test conditions for the melt index of the polypropylene resin are 230℃ and 2.16 kg.

3. The halogen-free, ablation-resistant polypropylene resin composition according to claim 1, characterized in that, The polypropylene resin includes homopolymer polypropylene and / or copolymer polypropylene.

4. The halogen-free, ablation-resistant polypropylene resin composition according to claim 1, characterized in that, The piperazine flame retardant includes any one or a combination of at least two of piperazine phosphate, piperazine pyrophosphate, or piperazine polyphosphate.

5. The halogen-free, ablation-resistant polypropylene resin composition according to claim 1, characterized in that, The nitrogen-phosphorus composite flame retardant includes melamine pyrophosphate and / or melamine polyphosphate.

6. The halogen-free, ablation-resistant polypropylene resin composition according to claim 5, characterized in that, The mass ratio of melamine pyrophosphate to melamine polyphosphate is (0.3~3):

1.

7. The halogen-free, ablation-resistant polypropylene resin composition according to claim 6, characterized in that, The mass ratio of melamine pyrophosphate to melamine polyphosphate is (1~2.6):

1.

8. The halogen-free, ablation-resistant polypropylene resin composition according to claim 1, characterized in that, The synergistic flame retardant includes any one or a combination of at least two of zinc oxide, zinc borate, glass powder, or sepiolite.

9. The halogen-free, ablation-resistant polypropylene resin composition according to claim 8, characterized in that, The synergistic flame retardant includes at least two of zinc oxide, sepiolite, and zinc borate.

10. The halogen-free, ablation-resistant polypropylene resin composition according to claim 9, characterized in that, The synergistic flame retardant is a combination of zinc oxide and zinc borate, or a combination of sepiolite and zinc borate.

11. The halogen-free, ablation-resistant polypropylene resin composition according to claim 10, characterized in that, The mass ratio of zinc oxide to zinc borate and the mass ratio of sepiolite to zinc borate are each independently (0.5~4.2):

1.

12. The halogen-free, ablation-resistant polypropylene resin composition according to claim 11, characterized in that, The mass ratio of zinc oxide to zinc borate and the mass ratio of sepiolite to zinc borate are each independently (1.2~4):

1.

13. The halogen-free, ablation-resistant polypropylene resin composition according to claim 1, characterized in that, The average retention length of the long glass fiber is >1 mm.

14. The halogen-free, ablation-resistant polypropylene resin composition according to claim 13, characterized in that, The average retention length of the long glass fibers is 1.2~3 mm.

15. The halogen-free, ablation-resistant polypropylene resin composition according to claim 1, characterized in that, The long glass fiber contains 65-70% silica by mass.

16. The halogen-free, ablation-resistant polypropylene resin composition according to claim 1, characterized in that, The long glass fibers are added in the form of long glass fiber masterbatch.

17. The halogen-free, ablation-resistant polypropylene resin composition according to claim 16, characterized in that, The long glass fiber masterbatch contains 40-60% long glass fiber by mass.

18. The halogen-free, ablation-resistant polypropylene resin composition according to claim 1, characterized in that, The halogen-free ablation-resistant polypropylene resin composition further includes 1 to 5 parts by weight of a compatibilizer.

19. The halogen-free, ablation-resistant polypropylene resin composition according to claim 18, characterized in that, The compatibilizer comprises polypropylene grafted with maleic anhydride and / or polyolefin elastomer grafted with maleic anhydride.

20. The halogen-free, ablation-resistant polypropylene resin composition according to claim 1, characterized in that, The halogen-free ablation-resistant polypropylene resin composition further includes 0.3 to 1.5 parts of other additives by weight.

21. The halogen-free, ablation-resistant polypropylene resin composition according to claim 20, characterized in that, The other additives include antioxidants and / or lubricants.

22. An article comprising the halogen-free, ablation-resistant polypropylene resin composition according to any one of claims 1 to 21, characterized in that, The product includes a battery pack cover.

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