Polypropylene composition as well as preparation method and application thereof

Abstract

The invention discloses a polypropylene composition as well as a preparation method and application thereof, and relates to the technical field of high polymer materials. The polypropylene composition comprises the following components: polypropylene resin; a toughening agent; a nitrogen and phosphorus flame retardant; an ionic polymer; grafting POE (Polyolefin Elastomer) with maleic anhydride; the ionic polymer comprises ethylene / methacrylic acid copolymer sodium salt and ethylene / methacrylic acid copolymer zinc salt, and the mass ratio of the ethylene / methacrylic acid copolymer sodium salt to the ethylene / methacrylic acid copolymer zinc salt is 1: (0.3-4). The polypropylene composition provided by the invention has excellent low-temperature toughness and flame retardant property, and also has excellent scratch resistance.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer materials, and in particular to a polypropylene composition, a preparation method and application thereof. Background Art

[0002] Polypropylene (PP) has the advantages of low density, easy processing, and excellent mechanical properties. It has been widely used in the automotive industry, home appliances, and machinery. With the rapid development of new energy vehicles, new energy batteries are being used more and more. Battery peripheral components (such as battery covers) all require certain flame retardant properties. Therefore, it is necessary to develop polypropylene compositions with excellent mechanical properties and flame retardant properties.

[0003] In order to improve the flame retardant properties of polypropylene materials, people have conducted a lot of research. CN 202210824132.0 Coupling agents and alkyl phosphoric acids in halogen-free flame retardant polypropylene materials improve the dispersion of flame retardants, thereby improving the flame retardant properties of the materials. CN202111152519.8 Adds polyvinylidene fluoride with self-extinguishing properties to polypropylene materials to improve the flame retardant properties of the materials. At present, the mechanical properties of polypropylene materials prepared by these schemes are relatively low, especially the low-temperature toughness is relatively low. Therefore, the art still needs to develop a flame retardant polypropylene material with excellent low-temperature toughness and flame retardant properties for automotive parts. Summary of the invention

[0004] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a polypropylene composition and a preparation method and application thereof. The polypropylene composition of the present invention has excellent low-temperature toughness and flame retardant properties, and also has excellent scratch resistance.

[0005] To achieve the above object, the technical solution adopted by the present invention is:

[0006] In a first aspect, the present invention provides a polypropylene composition comprising the following components in parts by weight:

[0007] Polypropylene resin 55-88 parts; toughening agent 8-12 parts; nitrogen-phosphorus flame retardant 18-25 parts; ion polymer 2-9 parts; maleic anhydride grafted POE 2-7 parts;

[0008] The ionic polymer comprises ethylene / methacrylic acid copolymer sodium salt and ethylene / methacrylic acid copolymer zinc salt, and the mass ratio of the ethylene / methacrylic acid copolymer sodium salt to the ethylene / methacrylic acid copolymer zinc salt is 1:(0.3-4), preferably 1:(0.5-2).

[0009] The present invention can prepare a polypropylene composition with excellent low-temperature toughness and flame retardant properties by simultaneously adding an ionomer and a compatibilizer maleic anhydride grafted POE to a halogen-free flame retardant polypropylene composition. In addition, the ionomer interacts with the halogen-free phosphorus-nitrogen flame retardant, which is beneficial to improving the dispersibility of the flame retardant. In addition, the maleic anhydride grafted POE can not only react with the halogen-free phosphorus-nitrogen flame retardant, but also has an excellent toughening effect, which improves the flame retardant properties and low-temperature toughness of the polypropylene composition, and is also beneficial to improving the scratch resistance of the composition.

[0010] The invention uses the compounding of ethylene / methacrylic acid copolymer sodium salt and ethylene / methacrylic acid copolymer zinc salt, which is beneficial to further improve the toughness of the polypropylene composition and also beneficial to improve the flame retardant performance of the composition.

[0011] Preferably, the melt flow rate of the ethylene / methacrylic acid copolymer sodium salt and the ethylene / methacrylic acid copolymer zinc salt at 190° C. / 2.16 kg load according to ISO 1133-2011 is 0.8-5 g / 10 min, more preferably 1-4 g / 10 min.

[0012] Preferably, the mass ratio of the ethylene / methacrylic acid copolymer sodium salt to the ethylene / methacrylic acid copolymer zinc salt may be any one of 1:0.5, 1:1, 1:1.5, 1:2 or both of the range values.

[0013] Preferably, the polypropylene resin has a melt flow rate of 1.5-6.5 g / 10 min, more preferably 2-6 g / 10 min, at 230° C. / 2.16 kg load according to GB / T 3682.1-2018.

[0014] More preferably, the polypropylene resin is a homopolymer polypropylene resin or a copolymer polypropylene resin.

[0015] Preferably, the maleic anhydride grafted POE has a melt flow rate of 1-4 g / 10 min at 190° C. / 2.16 kg load according to ISO 1133-2011.

[0016] More preferably, the maleic anhydride grafted POE is CMG5805, manufactured by Jiayirong Polymer (Shanghai) Co., Ltd.

[0017] Preferably, the toughening agent includes at least one of ethylene-butene copolymer, ethylene-octene copolymer and styrene copolymer elastomer.

[0018] Preferably, the styrene copolymer elastomer may be SEBS G1657 or SEBS G1653.

[0019] Preferably, the nitrogen-phosphorus flame retardant includes at least one of ammonium polyphosphate, melamine polyphosphate and melamine phosphate.

[0020] Preferably, the polypropylene composition further comprises 0.2-2 parts of an auxiliary agent.

[0021] Preferably, the auxiliary agent includes at least one of an antioxidant and a light stabilizer.

[0022] Preferably, the antioxidant is at least one of a hindered phenol antioxidant and a phosphite antioxidant, specifically antioxidant 1010, antioxidant 1076, antioxidant 3114, antioxidant 168, and antioxidant PEP-36.

[0023] Preferably, the light stabilizer is a hindered amine light stabilizer.

[0024] Preferably, the polypropylene composition comprises the following components in parts by weight:

[0025] 60-70 parts of polypropylene resin; 9-10 parts of toughening agent; 19-22 parts of flame retardant; 5-7 parts of ion polymer; 3-5 parts of maleic anhydride grafted POE.

[0026] Preferably, the mass percentage of the polypropylene resin in the polypropylene composition is not less than 50%.

[0027] In a second aspect, the present invention further provides a method for preparing a polypropylene composition, comprising the following steps:

[0028] After the components are uniformly mixed, they are added into a twin-screw extruder for melt mixing and extrusion granulation to obtain a polypropylene composition.

[0029] Preferably, the temperature of the melt mixing is 170-220° C., and the screw speed is 350-450 rpm.

[0030] In a third aspect, the present invention also provides an application of a polypropylene composition in automotive parts, specifically, battery peripheral parts.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] The present invention can prepare a polypropylene composition with excellent low-temperature toughness and flame retardant properties by simultaneously adding an ionomer and a compatibilizer maleic anhydride grafted POE to a halogen-free flame retardant polypropylene composition. In addition, the ionomer interacts with the halogen-free phosphorus-nitrogen flame retardant, which is beneficial to improving the dispersibility of the flame retardant. In addition, the maleic anhydride grafted POE can not only react with the halogen-free phosphorus-nitrogen flame retardant, but also has an excellent toughening effect, which improves the flame retardant properties and low-temperature toughness of the polypropylene composition, and is also beneficial to improving the scratch resistance of the composition. DETAILED DESCRIPTION

[0033] In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments, but the protection scope and implementation methods of the present invention are not limited thereto.

[0034] Unless otherwise specified, the materials and reagents used in the following examples are commercially available.

[0035] Examples 1-12

[0036] The embodiments of the polypropylene composition and the preparation method thereof of the present invention, the components of the polypropylene composition are shown in Table 1.

[0037] The method for preparing the polypropylene composition comprises the following steps:

[0038] After mixing all the components evenly, add them into a twin-screw extruder for melt mixing and extrusion granulation to obtain a polypropylene composition;

[0039] The temperature of the melt mixing is 170-220° C., and the screw speed is 350-450 rpm.

[0040] Comparative Examples 1-10

[0041] The difference between each comparative example and the embodiment is only in the type and proportion of components, as shown in Table 2.

[0042] Among the components described in each embodiment and comparative example:

[0043] The polypropylene resin 1 has a melt flow rate of 2 g / 10 min at 230° C. / 2.16 kg load according to GB / T 3682.1-2018, the manufacturer is Lanzhou Petrochemical, and the model is PP S28F;

[0044] The polypropylene resin 2 has a melt flow rate of 6 g / 10 min at 230° C. / 2.16 kg load according to GB / T 3682.1-2018, the manufacturer is Huajin Chemical, and the model is PP C30G.

[0045] The toughening agent is ethylene-butene copolymer, the manufacturer is Dow Chemical, and the model is POE ENGAGE 7467.

[0046] The nitrogen-phosphorus flame retardant is manufactured by Aidico and its model number is FP2200.

[0047] The ionic polymer 1 comprises ethylene / methacrylic acid copolymer sodium salt and ethylene / methacrylic acid copolymer zinc salt, and the mass ratio of the two is 1:0.5;

[0048] The ionic polymer 2 comprises ethylene / methacrylic acid copolymer sodium salt and ethylene / methacrylic acid copolymer zinc salt, and the mass ratio of the two is 1:1;

[0049] The ionic polymer 3 comprises ethylene / methacrylic acid copolymer sodium salt and ethylene / methacrylic acid copolymer zinc salt, and the mass ratio of the two is 1:2;

[0050] The ion polymer 4 comprises ethylene / methacrylic acid copolymer sodium salt and ethylene / methacrylic acid copolymer zinc salt, and the mass ratio of the two is 1:0.2;

[0051] The ionic polymer 5 includes ethylene / methacrylic acid copolymer sodium salt and ethylene / methacrylic acid copolymer zinc salt, and the mass ratio of the two is 1:5.

[0052] Among the ionomers 1-5, the melt flow rate of the sodium salt of ethylene / methacrylic acid copolymer at 190°C / 2.16kg load according to ISO 1133-2011 is 1.0 g / 10 min, and the brand is Surlyn 8020; the melt flow rate of the zinc salt of ethylene / methacrylic acid copolymer at 190°C / 2.16kg load according to ISO 1133-2011 is 1.0 g / 10 min, and the brand is Surlyn 9721.

[0053] The ion polymer 6 includes ethylene / methacrylic acid copolymer sodium salt and ethylene / methacrylic acid copolymer zinc salt, and the mass ratio of the two is 1:1; the melt flow rate of ethylene / methacrylic acid copolymer sodium salt at 190°C / 2.16kg load according to ISO 1133-2011 is 1.0g / 10min, and the brand is Surlyn 8020; the melt flow rate of ethylene / methacrylic acid copolymer zinc salt at 190°C / 2.16kg load according to ISO 1133-2011 is 1.6g / 10min, and the brand is Surlyn 9730.

[0054] The ion polymer 7 includes ethylene / methacrylic acid copolymer sodium salt and ethylene / methacrylic acid copolymer zinc salt, and the mass ratio of the two is 1:1; the melt flow rate of ethylene / methacrylic acid copolymer sodium salt at 190°C / 2.16kg load according to ISO 1133-2011 is 4.0g / 10min, and the brand is Surlyn 8945; the melt flow rate of ethylene / methacrylic acid copolymer zinc salt at 190°C / 2.16kg load according to ISO 1133-2011 is 1.6g / 10min, and the brand is Surlyn 9730.

[0055] The ion polymer 8 includes ethylene / methacrylic acid copolymer sodium salt and ethylene / methacrylic acid copolymer zinc salt, and the mass ratio of the two is 1:1; the melt flow rate of ethylene / methacrylic acid copolymer sodium salt at 190°C / 2.16kg load according to ISO 1133-2011 is 2.6g / 10min, and the brand is Surlyn 8140; the melt flow rate of ethylene / methacrylic acid copolymer zinc salt at 190°C / 2.16kg load according to ISO 1133-2011 is 1.0g / 10min, and the brand is Surlyn 9721.

[0056] The ion polymer 9 includes ethylene / methacrylic acid copolymer sodium salt and ethylene / methacrylic acid copolymer zinc salt, and the mass ratio of the two is 1:1; the melt flow rate of ethylene / methacrylic acid copolymer sodium salt at 190°C / 2.16kg load according to ISO 1133-2011 is 2.6g / 10min, and the brand is Surlyn 8140; the melt flow rate of ethylene / methacrylic acid copolymer zinc salt at 190°C / 2.16kg load according to ISO 1133-2011 is 4.0g / 10min, and the brand is Surlyn 9945.

[0057] The ionomer 10 is sodium salt of ethylene / methacrylic acid copolymer, has a melt flow rate of 1.0 g / 10 min at 190° C. / 2.16 kg load according to ISO 1133-2011, and has a brand name of Surlyn 8020.

[0058] The ion polymer 11 is ethylene / methacrylic acid copolymer zinc salt, has a melt flow rate of 1.0 g / 10 min at 190° C. / 2.16 kg load according to ISO 1133-2011, and has a brand name of Surlyn 9721.

[0059] The maleic anhydride grafted POE is manufactured by Dow Chemical and has a model number of AMPLIFY GR216. According to ISO1133, the melt flow rate at 190° C. / 2.16 kg load is 1.3 g / 10 min.

[0060] The antioxidants include antioxidant 1010 and antioxidant 168, the mass ratio of the antioxidants is 1:1, and they are commercially available.

[0061] The light stabilizer is a hindered amine light stabilizer, which is commercially available.

[0062] Unless otherwise specified, the components and raw materials used in the embodiments and comparative examples of the present invention are all commercially available raw materials, and the components and raw materials used in each parallel experiment are all of the same kind.

[0063] Table 1

[0064]

[0065]

[0066] Table 2

[0067]

[0068] In order to verify the performance of the polypropylene composition of the present invention, the polypropylene composition prepared in each example and comparative example was injection molded into a specimen to test the following properties.

[0069] Performance testing method:

[0070] 1. Flame retardant grade: tested according to UL94 vertical burning standard, the sample size is 125mm long, 13mm wide and 1.5mm thick.

[0071] 2. Low temperature toughness: Test the notched impact strength of the material at -30°C in accordance with ISO 180-2000 "Determination of Izod Impact Strength of Plastics".

[0072] 3. Scratch resistance: Test the scratch resistance of the material according to PV3952 "Plastic Interior Parts Scratch Resistance Test", contact force 10N, scratch speed 1000mm / min, test the change of L value before and after scratching. The larger the ΔL value, the worse the scratch resistance.

[0073] The performance parameters obtained from the above tests are shown in Tables 3 and 4.

[0074] Table 3

[0075]

[0076]

[0077] Table 4

[0078]

[0079] According to Table 2, the vertical burning time of the polypropylene composition of the present invention is less than 12s, and the Izod notched impact strength is greater than 5.7KJ / m 2 , the ΔL value is less than 1.27, indicating that the polypropylene composition of the present invention not only has excellent flame retardancy and low-temperature toughness, but also has excellent scratch resistance.

[0080] By comparing Comparative Examples 1-2 with Example 1, it can be found that no ionic polymer is added in Comparative Example 1, and no maleic anhydride grafted POE is added in Comparative Example 2. The vertical burning time in Comparative Examples 1-2 is much higher than that in Example 1, the Izod notched impact strength is lower than that in Example 1, and the scratch ΔL value is greater than that in Example 1, indicating that the present invention can make the polypropylene composition have excellent low-temperature toughness and flame retardant properties by compounding ionic polymer and maleic anhydride grafted POE, and also make the polypropylene composition have excellent scratch resistance.

[0081] By comparing Comparative Examples 3-4 with Example 1, it can be seen that in Comparative Examples 3 and 4, only ethylene / methacrylic acid copolymer sodium salt or ethylene / methacrylic acid copolymer zinc salt is added, and the flame retardant properties and low-temperature toughness of Comparative Examples 3-4 are not as good as those of Example 1, indicating that the present invention is beneficial to further improve the low-temperature toughness and flame retardant properties of the polypropylene composition by compounding ethylene / methacrylic acid copolymer sodium salt and ethylene / methacrylic acid copolymer zinc salt.

[0082] By comparing Comparative Examples 7-8 with Example 1, it can be seen that the compounding ratio of ethylene / methacrylic acid copolymer sodium salt or ethylene / methacrylic acid copolymer zinc salt in Comparative Examples 7-8 is not within the range specified by the present invention, and the flame retardant properties and low-temperature toughness of the polypropylene composition are not as good as those in Example 1, indicating that the present invention controls the mass ratio of ethylene / methacrylic acid copolymer sodium salt and ethylene / methacrylic acid copolymer zinc salt to 1: (0.3-4), so that the polypropylene composition has both excellent flame retardant properties and low-temperature toughness.

[0083] By comparing Comparative Examples 5-6 and 9-10 with Example 1, it can be seen that the amount of the ionomer in Comparative Example 5 is too low, and the flame retardant property of the polypropylene composition is poor. The amount of the ionomer in Comparative Example 6 is too high, and the toughness of the polypropylene composition is reduced; the amount of the maleic anhydride grafted POE in Comparative Example 9 is too low, and the flame retardant property of the polypropylene composition is reduced. The amount of the maleic anhydride grafted POE in Comparative Example 10 is too high, and the toughness of the polypropylene composition is affected. Therefore, the present invention is beneficial to improving the flame retardant property and low-temperature toughness of the polypropylene composition by controlling the amount of the ionomer and the maleic anhydride grafted POE within the range defined by the present invention.

[0084] It can be seen from Examples 1-3 that as the amount of ionic polymer gradually increases, the vertical burning time of the polypropylene composition first decreases and then increases, and the impact strength first increases and then decreases, indicating that the present invention can make the polypropylene composition have excellent flame retardant properties and low-temperature toughness by controlling the amount of ionic polymer.

[0085] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A polypropylene composition, characterized in that The composition comprises the following components in parts by weight: Polypropylene resin 55-88 parts; toughening agent 8-12 parts; nitrogen-phosphorus flame retardant 18-25 parts; ion polymer 2-9 parts; maleic anhydride grafted POE 2-7 parts; The ion polymer comprises ethylene / methacrylic acid copolymer sodium salt and ethylene / methacrylic acid copolymer zinc salt, and the mass ratio of the ethylene / methacrylic acid copolymer sodium salt to the ethylene / methacrylic acid copolymer zinc salt is 1:(0.3-4).

2. The polypropylene composition according to claim 1, characterized in that The melt flow rates of the ethylene / methacrylic acid copolymer sodium salt and the ethylene / methacrylic acid copolymer zinc salt at 190° C. / 2.16 kg load are both 0.8-5 g / 10 min.

3. The polypropylene composition according to claim 1, characterized in that The polypropylene resin has a melt flow rate of 1.5-6.5 g / 10 min at 230° C. / 2.16 kg load.

4. The polypropylene composition according to claim 1, characterized in that The toughening agent includes at least one of ethylene-butene copolymer, ethylene-octene copolymer and styrene copolymer elastomer.

5. The polypropylene composition according to claim 1, characterized in that The melt flow rate of maleic anhydride grafted POE at 190°C / 2.16kg load is 1-4g / 10min.

6. The polypropylene composition according to claim 1, characterized in that The polypropylene composition further comprises 0.2-2 parts of an auxiliary agent.

7. The polypropylene composition according to claim 6, characterized in that The auxiliary agent includes at least one of an antioxidant and a light stabilizer.

8. The polypropylene composition according to claim 7, characterized in that The antioxidant is at least one of a hindered phenol antioxidant and a phosphite antioxidant, and the light stabilizer is a hindered amine light stabilizer.

9. The method for preparing the polypropylene composition according to any one of claims 1 to 8, characterized in that: The following steps are involved: After the components are uniformly mixed, they are added into a twin-screw extruder for melt mixing and extrusion granulation to obtain a polypropylene composition.

10. Use of the polypropylene composition according to any one of claims 1 to 8 in automobile parts.

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