Halogen-free high-flame-retardant high-toughness polypropylene film material and preparation method thereof

Abstract

The invention relates to a halogen-free high-flame-retardant high-toughness polypropylene film material and a preparation method thereof. The film material comprises 35 to 45% of homopolymerized PP resin, 10 to 20% of copolymerized PP resin, 15 to 25% of a flame retardant A, 10 to 20% of a flame retardant B, 3 to 6% of a flame retardant C, 0.4 to 1.0% of a silicon flame retardant, 1 to 5% of zinc oxide, 0.3 to 0.7% of an anti-dripping agent and 0.1 to 0.5% of a lubricant. 0.2 to 0.5% of an antioxidant 168, and 0.2 to 0.5% of an antioxidant 1010. The preparation method comprises the following steps: drying and mixing the raw materials, then blending and granulating, and finally extruding, cooling with water, dicing and sieving to obtain the product. The product disclosed by the invention not only has high flame retardance (0.38 mm reaches V-0), but also has good toughness; the film can be used as an insulating film for power batteries of electronic appliances and new energy automobiles.

Description

Technical Field

[0001] The present invention relates to the technical field of thin films, and more specifically, to a halogen-free high flame-retardant and high-toughness polypropylene film material and a preparation method thereof. Background Art

[0002] Polypropylene (PP) is a semi-crystalline thermoplastic. It has relatively high impact resistance, strong mechanical properties, and is resistant to a variety of organic solvents and acid-base corrosion. It has a wide range of applications in the industrial field and is one of the common polymer materials. Polypropylene (PP) is widely used in industries such as machinery, automobiles, and electrical appliances due to its excellent properties such as high rigidity, high strength, good heat resistance, and easy processing. It is one of the varieties of general plastics with the fastest growth rate and the most active new product development.

[0003] However, PP is flammable, with a fast combustion rate, high heat release, and produces a large amount of molten droplets, making it easy to spread flames. Therefore, the research on flame-retardant PP has always been highly regarded at home and abroad. Adding flame retardants is the main measure to improve the flame-retardant performance of PP. The flame retardants used for PP mainly include halogen-based flame retardants, metal hydroxide flame retardants, intumescent flame retardants (IFR), etc. Although halogen-based flame retardants have good flame-retardant effects on PP, due to their serious environmental and safety problems in use and the serious reduction of the light stability of PP, the application of halogen-based flame retardants is increasingly restricted (Zhang Yushan, Gao Chunjuan, Cai Ronghua. Application research and development trend of bromine-based flame retardants. Chemical Industry and Engineering, 2, 26(5): 460-466). Metal hydroxides such as aluminum hydroxide and magnesium hydroxide are known as "pollution-free flame retardants" and have advantages such as non-volatility, good stability, non-toxic smoke, low cost, and rich resources. However, the flame-retardant efficiency of metal hydroxides is low. To obtain good flame-retardant effects, a large amount of addition is required. Coupled with poor compatibility with PP, it has a great impact on the processing performance and mechanical properties of PP (Wang Lili, Qiu Guixue, Pan Jiongxi, etc. Application technology and research progress of hydroxide flame retardants in polyethylene. Plastic Additives, 2005, (1): 12-16).

[0004] Therefore, only by further researching polypropylene materials can they be more widely used. Summary of the Invention

[0005] The purpose of the present invention is to provide a halogen-free high flame-retardant and high-toughness polypropylene film and a preparation method for solving the problem that the toughness and high flame-retardancy of polypropylene materials in the prior art cannot be balanced. In this method, five flame retardants, namely piperazine pyrophosphate, melamine polyphosphate, BDP, zinc oxide, and phenyl silicone-based flame retardant, are compounded to obtain a halogen-free polypropylene film material with a thickness of 0.38 mm reaching V-0 and good toughness at the same time.

[0006] To achieve the above invention object, the specific technical solution of the present invention is as follows:

[0007] A halogen-free high-flame-retardant and high-toughness polypropylene film material is composed of the following raw materials in mass percentages:

[0008] Homopolymerized PP resin: 35-45%;

[0009] Copolymerized PP resin: 10-20%;

[0010] Flame retardant A: 15-25%;

[0011] Flame retardant B: 10-20%;

[0012] Flame retardant C: 3-6%;

[0013] Silicon-based flame retardant: 0.4-1.0%;

[0014] Zinc oxide: 1-5%;

[0015] Antioxidant 168: 0.1-0.6%;

[0016] Antioxidant 1010: 0.1-0.6%;

[0017] Dripping inhibitor: 0.3-0.7%;

[0018] Lubricant: 0.1-0.5%; the sum of the total mass percentages is 100%.

[0019] Furthermore, in a halogen-free high-flame-retardant and high-toughness polypropylene film material, the melt flow rate of the homopolymerized PP resin is 2.5-4.0 g / 10 min (230°C, 2.16 kg).

[0020] Furthermore, in a halogen-free high-flame-retardant and high-toughness polypropylene film material, the melt flow rate of the copolymerized PP resin is 0.5-3.0 g / 10 min (230°C, 2.16 kg).

[0021] Furthermore, in a halogen-free high-flame-retardant and high-toughness polypropylene film material, the flame retardant A is melamine polyphosphate (abbreviation: MPP), the flame retardant A is in powder form, and its particle size D50 is 1-5 microns.

[0022] Furthermore, in a halogen-free high-flame-retardant and high-toughness polypropylene film material, the flame retardant B is piperazine pyrophosphate, the flame retardant B is in powder form, and its particle size D50 is 1-5 microns.

[0023] Furthermore, in a halogen-free high-flame-retardant and high-toughness polypropylene film material, the flame retardant C is bisphenol A-bis(diphenyl phosphate), abbreviation: BDP.

[0024] Further, in a halogen-free, highly flame-retardant and highly tough polypropylene film material, the zinc oxide material is in powder form, and the particle size D50 of the powdered zinc oxide is 1.25 microns.

[0025] Further, in a halogen-free, highly flame-retardant and highly tough polypropylene film material, the silicon-based flame retardant is phenyl siloxane, and its phenyl content is not less than 20% (mass percentage).

[0026] Further, in a halogen-free, highly flame-retardant and highly tough polypropylene film material, the anti-dripping agent is polytetrafluoroethylene coated with a copolymer of styrene and acrylonitrile.

[0027] Further, in a halogen-free, highly flame-retardant and highly tough polypropylene film material, the lubricant is any one or a mixture of several of calcium stearate, magnesium stearate, N,N'-ethylenebisstearamide and EBS.

[0028] Preferably, the preparation method of the above-mentioned highly flame-retardant and highly tough polypropylene film material includes the following steps:

[0029] a. Weigh the flame retardant A, flame retardant B, flame retardant C, zinc oxide, silicon-based flame retardant, anti-dripping agent, antioxidant and lubricant according to the ratio, and mix them evenly through a powder mixer to obtain mixture 1;

[0030] b. Weigh the homopolymer PP resin and the copolymer PP, add the silicon-based flame retardant and mix them at low speed in a high-speed mixer (preferably the mixing time is 30 seconds), and mix them evenly with the mixture 1 obtained through step a to obtain mixture 2;

[0031] c. The mixture 2 obtained through step b is kneaded by a kneader and compounded and granulated by a single-screw extruder to obtain the granular material 3, which is the halogen-free, highly flame-retardant and highly tough polypropylene film material.

[0032] Preferably, the kneading temperature in step c is 140°C and the kneading time is 10 minutes.

[0033] Further, the above-obtained granular material 3 (highly flame-retardant and highly tough polypropylene granular material) is further extruded through a single-screw cast film extrusion device to obtain a polypropylene film.

[0034] The highly flame-retardant and highly tough polypropylene film material of the above formula and the highly flame-retardant and highly tough polypropylene film material prepared by the above method can be used as an insulating film for power batteries of electronic appliances and new energy vehicles.

[0035] Compared with the prior art, the positive effects of the present invention are reflected in:

[0036] (1) The product of the present invention not only has high flame retardancy (meeting V-0 at 0.38 mm), but also has good toughness.

[0037] (2) It can be used as an insulating film for power batteries in electronic appliances and new energy vehicles. Detailed implementation manners

[0038] All features disclosed in this specification, or all steps in the disclosed methods or processes, except for mutually exclusive features and / or steps, can be combined in any manner.

[0039] Any feature disclosed in this specification (including claims and abstract), unless specifically stated, can be replaced by other equivalent or similar-purpose alternative features. That is, unless specifically stated, each feature is only an example in a series of equivalent or similar features.

[0040] The features and performance of the present invention will be further described in detail below in conjunction with embodiments.

[0041] In the following embodiments, the flame retardancy test method for 0.38 mm and 0.76 mm cast films in the longitudinal direction is tested according to UL-94.

[0042] The test method for the tensile strength and elongation at break of the standard sample strips cut from the film is GB / T1040-3.

[0043] The Izod notched impact strength is in accordance with GB / T 1843, and injection-molded into a 4×10×80 mm notched standard sample strip.

[0044] In the following embodiments, the homopolymer PP resin is polypropylene produced by Sinopec Sichuan Petrochemical Company, with the model L5E89; the copolymer PP resin is Sinopec K8003; flame retardant A is melamine polyphosphate (commercially available product), with a particle size D50 of 1-5 microns; flame retardant B is piperazine pyrophosphate (commercially available product), with a particle size D50 of 1-5 microns; flame retardant C is bisphenol A-bis(diphenyl phosphate) (commercially available product); zinc oxide (commercially available product), with a particle size D50 of 1.25 microns; the silicon-based flame retardant is phenyl silicone, and Dow Corning 40-001 is selected; the anti-dripping agent is polytetrafluoroethylene coated with a copolymer of styrene and acrylonitrile (commercially available product); the lubricant is calcium stearate (commercially available product); antioxidant 168 (commercially available product); antioxidant 1010 (commercially available product).

[0045] In this application, unless otherwise specified, % represents its mass percentage.

[0046] Comparative example 1:

[0047] Weigh homopolymer PP resin 50%, copolymer PP resin 22.2%, flame retardant A 10%, flame retardant B 10%, flame retardant C 5%, silicon-based flame retardant 0.5%, zinc oxide 1%, antioxidant 168 0.2%, antioxidant 1010 0.3%, anti-dripping agent 0.5% and lubricant 0.3% according to the ratio, and then mix them evenly to obtain mixture 1; Weigh homopolymer PP resin and copolymer PP and mixture 1 obtained through step a according to the ratio, and then mix them evenly to obtain mixture 2; The mixture 2 obtained through step b is compounded and granulated by a kneader and a single-screw extruder to obtain mixture 3; The mixture 3 obtained in step c is extruded, cooled by passing through water, cut into particles and sieved to obtain granular products. Through a single-screw casting film extrusion device, it is extruded into a polypropylene film.

[0048] Comparative Example 2

[0049] Weigh homopolymer PP resin 45%, copolymer PP resin 15%, flame retardant A 18%, flame retardant B 15.2%, flame retardant C 5%, silicon-based flame retardant 0.5%, antioxidant 168 0.2%, antioxidant 1010 0.3%, anti-dripping agent 0.5% and lubricant 0.3% according to the ratio, and then mix them evenly to obtain mixture 1; Weigh homopolymer PP resin and copolymer PP and mixture 1 obtained through step a according to the ratio, and then mix them evenly to obtain mixture 2; The mixture 2 obtained through step b is compounded and granulated by a kneader and a single-screw extruder to obtain mixture 3; The mixture 3 obtained in step c is extruded, cooled by passing through water, cut into particles and sieved to obtain granular products. Through a single-screw casting film extrusion device, it is extruded into a polypropylene film.

[0050] Comparative Example 3

[0051] Weigh homopolymer PP resin 20.2%, copolymer PP resin 15%, flame retardant A 35%, flame retardant B 20%, flame retardant C 5%, zinc oxide 3%, silicon-based flame retardant 0.5%, antioxidant 168 0.2%, antioxidant 1010 0.3%, anti-dripping agent 0.5% and lubricant 0.3% according to the ratio, and then mix them evenly to obtain mixture 1; Weigh homopolymer PP resin and copolymer PP and mixture 1 obtained through step a according to the ratio, and then mix them evenly to obtain mixture 2; The mixture 2 obtained through step b is compounded and granulated by a kneader and a single-screw extruder to obtain mixture 3; The mixture 3 obtained in step c is extruded, cooled by passing through water, cut into particles and sieved to obtain granular products. Through a single-screw casting film extrusion device, it is extruded into a polypropylene film.

[0052] Example 1

[0053] Weigh homopolymer PP resin 42.2%, copolymer PP resin 15%, flame retardant A 18%, flame retardant B 15%, flame retardant C 5%, zinc oxide 3%, silicon-based flame retardant 0.5%, antioxidant 168 0.2%, antioxidant 1010 0.3%, anti-dripping agent 0.5% and lubricant 0.3% according to the ratio, and then mix them evenly to obtain mixture 1; Weigh homopolymer PP resin and copolymer PP and mixture 1 obtained through step a according to the ratio, and then mix them evenly to obtain mixture 2; The mixture 2 obtained through step b is melt-blended and pelletized in a mixer and a single-screw extruder to obtain mixture 3; The mixture 3 obtained in step c is extruded, cooled by passing through water, pelletized and sieved to obtain granular products. Through a single-screw cast film extrusion device, it is extruded into a polypropylene film.

[0054] Example 2

[0055] Weigh homopolymer PP resin 44.2%, copolymer PP resin 15%, flame retardant A 20%, flame retardant B 10%, flame retardant C 5%, silicon-based flame retardant 0.5%, zinc oxide 3%, antioxidant 168 0.2%, antioxidant 1010 0.3%, anti-dripping agent 0.5% and lubricant 0.3% according to the above ratio, and then mix them evenly to obtain mixture 1; Weigh homopolymer PP resin and copolymer PP and mixture 1 obtained through step a according to the ratio, and then mix them evenly to obtain mixture 2; The mixture 2 obtained through step b is melt-blended and pelletized in a mixer and a single-screw extruder to obtain mixture 3; The mixture 3 obtained in step c is extruded, cooled by passing through water, pelletized and sieved to obtain granular products. Through a single-screw cast film extrusion device, it is extruded into a polypropylene film.

[0056] Example 3

[0057] Weigh homopolymer PP resin 39.2%, copolymer PP resin 15%, flame retardant A 15%, flame retardant B 20%, flame retardant C 5%, silicon-based flame retardant 0.5%, zinc oxide 3%, antioxidant 168 0.2%, antioxidant 1010 0.3%, anti-dripping agent 0.5% and lubricant 0.3% according to the ratio, and then mix them evenly to obtain mixture 1; Weigh homopolymer PP resin and copolymer PP and mixture 1 obtained through step a according to the ratio, and then mix them evenly to obtain mixture 2; The mixture 2 obtained through step b is melt-blended and pelletized in a mixer and a single-screw extruder to obtain mixture 3; The mixture 3 obtained in step c is extruded, cooled by passing through water, pelletized and sieved to obtain granular products. Through a single-screw cast film extrusion device, it is extruded into a polypropylene film.

[0058] Example 4

[0059] Weigh homopolymer PP resin 41.2%, copolymer PP resin 15%, flame retardant A 20%, flame retardant B 15%, flame retardant C 5%, silicon-based flame retardant 0.5%, zinc oxide 3%, antioxidant 168 0.2%, antioxidant 1010 0.3%, anti-dripping agent 0.5% and lubricant 0.3% according to the ratio, and then mix them evenly to obtain mixture 1; Weigh homopolymer PP resin and copolymer PP and mixture 1 obtained through step a according to the ratio, and then mix them evenly to obtain mixture 2; The mixture 2 obtained through step b is compounded and granulated by a mixer and a single-screw extruder to obtain mixture 3; The mixture 3 obtained in step c is extruded, cooled by passing through water, cut into particles and sieved to obtain granular products. Through a single-screw cast film extrusion device, it is extruded into a polypropylene film.

[0060] Example 5

[0061] Weigh homopolymer PP resin 38.2%, copolymer PP resin 15%, flame retardant A 20%, flame retardant B 20%, flame retardant C 3%, silicon-based flame retardant 0.5%, zinc oxide 3%, antioxidant 168 0.2%, antioxidant 1010 0.3%, anti-dripping agent 0.5% and lubricant 0.3% according to the ratio, and then mix them evenly to obtain mixture 1; Weigh homopolymer PP resin and copolymer PP and mixture 1 obtained through step a according to the ratio, and then mix them evenly to obtain mixture 2; The mixture 2 obtained through step b is compounded and granulated by a mixer and a single-screw extruder to obtain mixture 3; The mixture 3 obtained in step c is extruded, cooled by passing through water, cut into particles and sieved to obtain granular products. Through a single-screw cast film extrusion device, it is extruded into a polypropylene film.

[0062] Example 6

[0063] Weigh homopolymer PP resin 36.2%, copolymer PP resin 13%, flame retardant A 20%, flame retardant B 22%, flame retardant C 5%, silicon-based flame retardant 0.5%, zinc oxide 3%, antioxidant 168 0.2%, antioxidant 1010 0.3%, anti-dripping agent 0.5% and lubricant 0.3% according to the ratio, and then mix them evenly to obtain mixture 1; Weigh homopolymer PP resin and copolymer PP and mixture 1 obtained through step a according to the ratio, and then mix them evenly to obtain mixture 2; The mixture 2 obtained through step b is compounded and granulated by a mixer and a single-screw extruder to obtain mixture 3; The mixture 3 obtained in step c is extruded, cooled by passing through water, cut into particles and sieved to obtain granular products. Through a single-screw cast film extrusion device, it is extruded into a polypropylene film.

[0064] Example 7

[0065] Weigh homopolymer PP resin 39.2%, copolymer PP resin 15%, flame retardant A 25%, flame retardant B 20%, flame retardant C 3%, silicon-based flame retardant 0.5%, zinc oxide 3%, antioxidant 168 0.2%, antioxidant 1010 0.3%, anti-dripping agent 0.5% and lubricant 0.3% according to the ratio, and then mix them evenly to obtain mixture 1; Weigh homopolymer PP resin and copolymer PP and mixture 1 obtained through step a according to the ratio, and then mix them evenly to obtain mixture 2; The mixture 2 obtained through step b is compounded and pelletized by a kneader and a single-screw extruder to obtain mixture 3; The mixture 3 obtained in step c is extruded, cooled by passing through water, cut into pellets and sieved to obtain granular products. Through a single-screw casting film extrusion device, it is extruded into a polypropylene film.

[0066] Example 8

[0067] Weigh homopolymer PP resin 35%, copolymer PP resin 10%, flame retardant A 25%, flame retardant B 20%, flame retardant C 5%, silicon-based flame retardant 0.7%, zinc oxide 3%, antioxidant 168 0.2%, antioxidant 1010 0.3%, anti-dripping agent 0.5% and lubricant 0.3% according to the ratio, and then mix them evenly to obtain mixture 1; Weigh homopolymer PP resin and copolymer PP and mixture 1 obtained through step a according to the ratio, and then mix them evenly to obtain mixture 2; The mixture 2 obtained through step b is compounded and pelletized by a kneader and a single-screw extruder to obtain mixture 3; The mixture 3 obtained in step c is extruded, cooled by passing through water, cut into pellets and sieved to obtain granular products. Through a single-screw casting film extrusion device, it is extruded into a polypropylene film.

[0068] Table 1 Test results of the flame retardancy and mechanical properties of halogen-free high-flame-retardant and high-toughness polypropylene for Comparative Examples 1-3 and Examples 1-8:

[0069]

[0070]

[0071] As can be seen from Table 1, a halogen-free high-flame-retardant and high-toughness polypropylene prepared by the present invention has excellent comprehensive properties. From Comparative Example 1, the amount of the flame retardant is less than 30%, and its flame retardancy of 0.76 mm fails to reach V-0. In Comparative Example 2, zinc oxide is removed, and its flame retardancy also decreases. In Comparative Example 3, when the amount of the flame retardant is more than 60 parts, its film-forming property and impact are very low, resulting in unqualified mechanical properties of the film. In Examples 1-5, when the compounding ratio is more than 35%, the flame retardancy of 0.76 mm can reach UL94 V-0. At the same time, the elongation at break can also reach about 200. When the addition amount of the flame retardant in Examples 6-8 is about 50 parts, the PP composite material can reach the UL-94 (0.38 mm) V-0 grade, and it maintains excellent comprehensive mechanical properties.

[0072] The embodiments described above only represent the specific implementation manners of the present application. The description is relatively specific and detailed, but it should not be construed as a limitation on the protection scope of the present application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the technical solution of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application.

[0073] This background art section is provided to generally present the context of the present invention. The work of the currently named inventors, to the extent described in this background art section, and aspects of the work described in this section that are not yet prior art as of the filing of the application are neither expressly nor impliedly admitted to be prior art to the present invention.

Claims

1. A halogen-free, highly flame-retardant, high-toughness polypropylene film material, characterized in that: It is composed of the following raw materials in percentage by weight: Homopolymer PP resin 35-45%; Copolymer PP resin 10-20%; Flame retardant A 15-25%; Flame retardant B12-20%; Flame retardant C 3-6%; Silicon flame retardant 0.4-1.0%; Zinc oxide 1-5%; Antioxidant 168 0.1-0.6%; Antioxidant 1010 0.1-0.6%; Anti-drip agent 0.3-0.7%; Lubricant 0.1-0.5%; the sum of the total mass percentage is 100%.

2. The halogen-free, highly flame-retardant, high-toughness polypropylene film material according to claim 1, characterized in that: The melt flow rate of the homopolymer PP resin is 2.5-4.0 g / 10 min; the melt flow rate of the copolymer PP resin is 0.5-3.0 g / 10 min.

3. The halogen-free, highly flame-retardant, high-toughness polypropylene film material according to claim 1, characterized in that: The flame retardant A is melamine polyphosphate; the flame retardant A is in powder form, and its particle size D50 is 1-5 microns; the flame retardant B is piperazine pyrophosphate; the flame retardant B is in powder form, and its particle size D50 is 1-5 microns; the flame retardant C is bisphenol A-bis(diphenyl phosphate).

4. The halogen-free, highly flame-retardant, high-toughness polypropylene film material according to claim 1, characterized in that: The zinc oxide is in powder form, and its particle size D50 is 1.25 microns.

5. The halogen-free, highly flame-retardant, high-toughness polypropylene film material according to claim 1, characterized in that: The silicon-based flame retardant is phenylsiloxane, and the mass percentage of phenyl in the phenyl group is not less than 20%.

6. The halogen-free, highly flame-retardant, high-toughness polypropylene film material according to claim 1, characterized in that: The anti-dripping agent is polytetrafluoroethylene coated with a copolymer of styrene and acrylonitrile.

7. The halogen-free, highly flame-retardant, high-toughness polypropylene film material according to claim 1, characterized in that: The lubricant is any one of calcium stearate, magnesium stearate or N,N'-ethylene bis stearamide or a mixture of several of them.

8. The method for preparing the halogen-free, highly flame-retardant and high-toughness polypropylene film material according to any one of claims 1 to 7, characterized in that: The following steps are involved: a. Weigh flame retardant A, flame retardant B, flame retardant C, silicon flame retardant, zinc oxide, anti-dripping agent, antioxidant and release agent according to the proportion, and then mix them evenly to obtain mixture 1; b. Weigh the homopolymer PP resin and copolymer PP and the mixture 1 obtained in step a according to the proportion, and then mix them evenly to obtain a mixture 2; c. The mixed material 2 obtained in step b is mixed in an internal mixer and then granulated in a single screw extruder to obtain a granular material 3, that is, a halogen-free, highly flame-retardant, and high-toughness polypropylene film material.

9. The method for preparing the halogen-free, highly flame-retardant and high-toughness polypropylene film material according to claim 11, characterized in that: The halogen-free, highly flame-retardant and high-toughness polypropylene film material is extruded through a single-screw cast film device to obtain a polypropylene film.

10. Use of the halogen-free, highly flame-retardant, high-toughness polypropylene film material according to claims 1-7 or the halogen-free, highly flame-retardant, high-toughness polypropylene film material prepared by the method according to claim 8 as an insulating film in the field of power batteries for electronic appliances and new energy vehicles.

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