Polypropylene-based composite material and preparation method and application thereof

Abstract

The present invention relates to a polypropylene-based composite material and a preparation method and application thereof. The composite material comprises the following components in parts by weight: 5-60 parts of polypropylene resin; 1-55 parts of maleic anhydride grafted polymer; 10-40 parts of alkali-free glass fiber; 0.1-15 parts of aminosilane oligomer; 0.1-1 parts of initiator; 2-8 parts of flame retardant; 0.1-4 parts of synergistic flame retardant; and 0.1-0.5 parts of nucleating agent; the grafting rate of the maleic anhydride grafted polymer is ≥0.1%; the initiator is one or a mixture of dicumyl peroxide, azobisisobutyronitrile, 2,3-dimethyl-2,3-diphenylbutane; the flame retardant is a bromine-containing compound; and the synergistic flame retardant is an antimony-containing compound. The polypropylene-based composite material has high surface polarity, can be printed, is resistant to high temperatures, has good mechanical properties, and has good flame retardancy.

Description

Technical Field

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

[0002] In recent years, with the vigorous development of the LED lighting industry, the materials of its related components are in short supply. At present, the main material of LED lamp holders is polybutylene terephthalate (PBT), which has excellent heat resistance, toughness, mechanical properties and fatigue resistance, low water absorption rate of only 0.1%, and still maintains various physical properties (including electrical properties) in a humid environment, but its cost is relatively high. The market has recently begun to look for materials with better performance and lower cost, and requires them to have better printability, mechanical properties and flame retardancy.

[0003] Polypropylene (PP) is a translucent, colorless, solid, odorless, and non-toxic polymer material. It has a regular structure and is easy to crystallize. Its melting point is as high as 168°C. It is heat-resistant, corrosion-resistant, and has a low density. It is the lightest general-purpose plastic. However, since PP itself is a non-polar material, the printability of the resulting product is poor; in addition, PP is a flammable material. Summary of the invention

[0004] Based on this, it is necessary to provide a polypropylene-based composite material with high surface polarity, printability, high temperature resistance, good mechanical properties and good flame retardancy to address the above problems.

[0005] The technical solution is as follows:

[0006] A polypropylene-based composite material comprises the following components in parts by weight:

[0007]

[0008]

[0009] The grafting rate of the maleic anhydride grafted polymer is ≥ 0.1%;

[0010] The initiator is one or a mixture of dicumyl peroxide, azobisisobutyronitrile, 2,3-dimethyl-2,3-diphenylbutane;

[0011] The flame retardant is a bromine-containing compound;

[0012] The synergistic flame retardant is an antimony-containing compound.

[0013] In one embodiment, the polypropylene-based composite material comprises the following components in parts by weight:

[0014]

[0015] In one embodiment, the flame retardant is selected from one or a mixture of octabromoether, octabromosulfide, hexabromocyclododecane and tris(2,3-dibromopropyl)isocyanurate.

[0016] In one embodiment, the synergistic flame retardant is selected from antimony trioxide and antimony pentoxide, or a mixture of the two.

[0017] In one embodiment, the nucleating agent is selected from one or a mixture of substituted aromatic heterocyclic phosphate α-nucleating agents, aromatic carboxylic acid aluminum salt α-nucleating agents and aromatic amide β-nucleating agents.

[0018] In one of the embodiments, at 230°C / 2.16Kg, the melt flow rate of the polypropylene resin is ≥20g / 10min.

[0019] In one embodiment, the grafting rate of the maleic anhydride grafted polymer is 0.5% to 1.5%.

[0020] In one embodiment, the maleic anhydride grafted polymer is selected from one or more of maleic anhydride grafted polypropylene, maleic anhydride grafted polyethylene and maleic anhydride grafted polyolefin elastomer.

[0021] In one embodiment, the alkali-free glass fiber is a chopped glass fiber with a diameter of 9 μm to 15 μm and a length of 3 mm to 5 mm.

[0022] In one embodiment, the aminosilane oligomer is selected from one or a mixture of monoaminosilane oligomer, water-soluble monoaminosilane oligomer and bisaminosilane oligomer.

[0023] In one embodiment, the polypropylene-based composite material further comprises one or more of a filler, an antioxidant and a lubricant.

[0024] In one embodiment, the filler is selected from one or a mixture of nano barium sulfate, nano talc and titanium dioxide.

[0025] In one embodiment, the antioxidant is selected from one or a mixture of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate and tris[2,4-di-tert-butylphenyl]phosphite.

[0026] In one embodiment, the lubricant is one or a mixture of calcium stearate, N,N'-ethylene bisstearamide, erucic acid amide.

[0027] In one of the embodiments, the polypropylene-based composite material further comprises, by weight, 10 to 20 parts of filler, 0.2 to 0.5 parts of antioxidant and 0.1 to 0.5 parts of lubricant.

[0028] The present invention also provides a method for preparing the polypropylene-based composite material as described above, comprising the following steps:

[0029] The polypropylene resin, maleic anhydride grafted polymer, alkali-free glass fiber, aminosilane oligomer, initiator, flame retardant, synergistic flame retardant and nucleating agent are mixed, melted and extruded.

[0030] The present invention also provides the use of the polypropylene-based composite material described above in the preparation of household appliances, electronic appliances or automobiles.

[0031] The present invention also provides a lighting fixture, which comprises the polypropylene-based composite material as described above.

[0032] The present invention has the following beneficial effects:

[0033] The polypropylene-based composite material of the present invention uses polypropylene as a base material, achieves a reinforcing effect through alkali-free glass fiber, and uses a small amount of nucleating agent to give the composite material more excellent mechanical properties, dimensional stability and heat resistance; uses maleic anhydride grafted polymer, aminosilane oligomer and initiator in combination, can increase the polarity of the polypropylene-based composite material and improve its printability; and the maleic anhydride grafted polymer also has a volume-increasing effect, improves the compatibility between the components, and improves the product appearance and various properties; at the same time, the aminosilane oligomer makes the composite material more flammable, and the inventor creatively uses a specific initiator, a flame retardant and a synergistic flame retardant (bromine-antimony system) in combination to significantly improve the flame retardancy of the composite material. In addition, adding a small amount of initiator can greatly reduce the amount of flame retardant, can well control the amount of smoke generated by combustion and reduce the corrosion to the mold, effectively reduce the material cost, and has considerable economic benefits.

[0034] In summary, the composite material provided by the present invention has excellent printability, mechanical properties, heat resistance, flame retardancy and dimensional stability, which greatly broadens the application field of polypropylene materials, such as electronics, electrical, communications and automotive fields, and can be further applied to lighting components, especially LED lamp holders. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a picture showing the effect of the polypropylene-based composite material prepared in Comparative Example 2 after being printed and wiped 10 times with n-hexane;

[0036] Figure 2 This is a picture showing the effect of the polypropylene-based composite material prepared in Example 2 after being printed and wiped 100 times with n-hexane. DETAILED DESCRIPTION

[0037] The present invention will be further described in detail below in conjunction with specific embodiments. The present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thoroughly understood.

[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0039] In the present invention, the technical features described in an open manner include closed technical solutions composed of the listed features, and also include open technical solutions containing the listed features.

[0040] In the present invention, when it comes to numerical ranges, unless otherwise specified, the above numerical ranges are considered continuous and include the minimum and maximum values ​​of the range, as well as each value between such minimum and maximum values. Further, when a range refers to an integer, each integer between the minimum and maximum values ​​of the range is included. In addition, when multiple ranges are provided to describe features or characteristics, the ranges can be merged. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges included therein.

[0041] The temperature parameters in the present invention, if not specifically limited, allow for both constant temperature treatment and treatment within a certain temperature range. The constant temperature treatment allows the temperature to fluctuate within the precision range controlled by the instrument.

[0042] In the present invention, when it comes to the unit of the data range, if there is a unit only after the right endpoint, it means that the units of the left endpoint and the right endpoint are the same. For example, 150-160°C means that the units of the left endpoint "150" and the right endpoint "160" are both ℃ (Celsius).

[0043] In the present invention, in the description of the invention, the meaning of "several" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined. In the description of the present application, the meaning of "several" is at least one, such as one, two, etc., unless otherwise clearly and specifically defined.

[0044] If not otherwise specified, all embodiments and optional embodiments of the present invention can be combined with each other to form a new technical solution.

[0045] If not otherwise specified, all steps of the present invention may be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), which means that the method may include steps (a) and (b) performed sequentially, or may include steps (b) and (a) performed sequentially. For example, the method may further include step (c), which means that step (c) may be added to the method in any order, for example, the method may include steps (a), (b) and (c), or may include steps (a), (c) and (b), or may include steps (c), (a) and (b), etc.

[0046] It should be noted that, in the description of the present invention, directional words such as the terms "center", "lateral", "longitudinal", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", etc., indicating directions and positional relationships are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of narrating the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and cannot be understood as limiting the specific protection scope of the present invention.

[0047] Where “including,” “having,” and “comprising” are used herein, it is intended to cover a non-exclusive inclusion, and another component may also be added unless explicit limiting terms such as “only,” “consisting of,” etc. are used.

[0048] Unless mentioned to the contrary, terms in the singular may include plural forms and should not be construed as being one in number.

[0049] In the present invention, the grafting ratio refers to the mass ratio of the polar monomer grafted onto the polypropylene to the mass ratio of the grafted polypropylene.

[0050] The invention provides a polypropylene-based composite material which has high surface polarity, is printable, is resistant to high temperatures, has good mechanical properties and is flame retardant.

[0051] The technical solution is as follows:

[0052] A polypropylene-based composite material comprises the following components in parts by weight:

[0053]

[0054] The grafting rate of the maleic anhydride grafted polymer is ≥ 0.1%;

[0055] The initiator is one or a mixture of dicumyl peroxide, azobisisobutyronitrile, 2,3-dimethyl-2,3-diphenylbutane;

[0056] The flame retardant is a bromine-containing compound;

[0057] The synergistic flame retardant is an antimony-containing compound.

[0058] The invention uses polypropylene as the base material, and uses alkali-free glass fiber to achieve the reinforcement effect. A small amount of nucleating agent is used in combination to give the composite material more excellent mechanical properties, dimensional stability and heat resistance. The maleic anhydride grafted polymer, aminosilane oligomer and initiator are used in combination to increase the polarity of the polypropylene-based composite material and improve its printability. The maleic anhydride grafted polymer also has the effect of increasing the volume, improving the compatibility between the components, and improving the product appearance and various properties. At the same time, the aminosilane oligomer makes the composite material more flammable. The inventor creatively uses a specific initiator, a flame retardant and a synergistic flame retardant (bromine-antimony system) in combination to significantly improve the flame retardancy of the composite material. In addition, adding a small amount of initiator can greatly reduce the amount of flame retardant, can well control the amount of smoke generated during combustion and reduce the corrosion to the mold, effectively reduce the material cost, and has considerable economic benefits.

[0059] In one embodiment, the polypropylene-based composite material comprises the following components in parts by weight:

[0060]

[0061] In the present invention, the polypropylene-based composite material includes 5 to 60 parts of polypropylene resin, including but not limited to 5 parts, 10 parts, 15 parts, 20 parts, 25 parts, 30 parts, 35 parts, 40 parts, 45 parts, 50 parts, 55 parts and 60 parts, preferably 20 to 55 parts.

[0062] In one embodiment, at 230°C / 2.16Kg, the melt flow rate of the polypropylene resin is ≥20g / 10min. Such a polypropylene resin can provide better processing fluidity, meet the molding requirements of one mold with multiple cavities, and ensure production efficiency.

[0063] It can be understood that in the present invention, the polypropylene resin can be selected from one or a mixture of homopolymer PP or copolymer PP. Wherein, the homopolymer PP is selected from one or a mixture of isotactic PP, syndiotactic PP or atactic PP. The copolymer PP is an ethylene-propylene copolymer, and further, the mass fraction of polyethylene in the ethylene-propylene copolymer is 6% to 15%. In one embodiment, the polypropylene resin is Sinopec K7726H.

[0064] In the present invention, the polypropylene-based composite material includes 1 to 55 parts of maleic anhydride grafted polymer, including but not limited to 1 part, 5 parts, 10 parts, 15 parts, 20 parts, 25 parts, 30 parts, 35 parts, 40 parts, 45 parts, 50 parts and 55 parts, preferably 10 to 40 parts.

[0065] In the present invention, the grafting rate of the maleic anhydride grafted polymer is ≥ 0.1%, including but not limited to: 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7% and 1.8%. Preferably, the grafting rate of the maleic anhydride grafted polymer is 0.5% to 1.5%, which can ensure that the polypropylene resin and the alkali-free glass fiber can be well bonded, and the anhydride groups contained in the material give the material a certain polarity.

[0066] In one embodiment, the maleic anhydride grafted polymer is selected from one or more of maleic anhydride grafted polypropylene (PP-g-MAH), maleic anhydride grafted polyethylene (PE-g-MAH) and maleic anhydride grafted polyolefin elastomer (POE-g-MAH). Preferably, the maleic anhydride grafted polymer is maleic anhydride grafted polypropylene.

[0067] In the present invention, the polypropylene-based composite material includes 10 to 40 parts of alkali-free glass fiber, including but not limited to 10 parts, 12 parts, 15 parts, 20 parts, 25 parts, 30 parts, 35 parts and 40 parts, preferably 15 to 30 parts.

[0068] In one embodiment, the alkali-free glass fiber is a chopped glass fiber with a diameter of 9 μm to 15 μm and a length of 3 mm to 5 mm. Preferably, the alkali-free glass fiber has a diameter of 11 μm to 13 μm and a length of 3 mm to 4.5 mm.

[0069] In the present invention, the polypropylene-based composite material includes 0.1 to 15 parts of aminosilane oligomer, including but not limited to 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 and 15 parts, preferably 1 to 10 parts.

[0070] In one embodiment, the aminosilane oligomer is selected from one or a mixture of monoaminosilane oligomer, water-soluble monoaminosilane oligomer and bisaminosilane oligomer.

[0071] In the present invention, the polypropylene-based composite material includes 0.1 to 1 parts of an initiator, and the initiator is one or a mixture of dicumyl peroxide, azobisisobutyronitrile, 2,3-dimethyl-2,3-diphenylbutane, and the initiator plays an important role in the polarity and flame retardancy of the composite material of the present invention. It can be understood that the polypropylene-based composite material includes but is not limited to 0.1 parts, 0.2 parts, 0.3 parts, 0.4 parts, 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts and 1 parts of the initiator, preferably 0.2 to 0.8 parts of the initiator.

[0072] In the present invention, the polypropylene-based composite material includes 2 to 8 parts of flame retardant, and the flame retardant is a bromine-containing compound with high efficiency flame retardant effect. It can be understood that the polypropylene-based composite material includes but is not limited to 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts and 8 parts of flame retardant, preferably 2 to 7 parts of flame retardant.

[0073] In one embodiment, the flame retardant is selected from one or a mixture of octabromoether, octabromosulfide, hexabromocyclododecane and tris(2,3-dibromopropyl)isocyanurate.

[0074] In the present invention, the polypropylene-based composite material includes 0.1 to 4 parts of a synergistic flame retardant, and the synergistic flame retardant is an antimony-containing compound, which is combined with a flame retardant to give the composite material excellent flame retardancy. It can be understood that the polypropylene-based composite material includes but is not limited to 0.1 parts, 0.5 parts, 0.8 parts, 1 parts, 1.5 parts, 2 parts, 2.5 parts, 3 parts, 3.5 parts and 4 parts of a synergistic flame retardant, preferably 1 to 4 parts of a synergistic flame retardant.

[0075] In one embodiment, the synergistic flame retardant is selected from antimony trioxide and antimony pentoxide, or a mixture of the two.

[0076] In the present invention, the polypropylene-based composite material includes 0.1 to 0.5 parts of a nucleating agent, including but not limited to 0.1 parts, 0.2 parts, 0.3 parts, 0.4 parts and 0.5 parts, preferably 0.2 to 0.5 parts.

[0077] In one embodiment, the nucleating agent is selected from one or more of substituted aromatic heterocyclic phosphate α nucleating agents, aromatic carboxylic acid aluminum salt α nucleating agents and aromatic amide β nucleating agents, and these nucleating agents can make the mechanical properties, heat resistance and dimensional stability of the composite material more excellent. Preferably, the nucleating agent is selected from substituted aromatic heterocyclic phosphate α nucleating agents and / or aromatic carboxylic acid aluminum salt α nucleating agents, and only a small amount of addition is required to make the material mechanical properties, heat resistance and dimensional stability more excellent. Further preferably, the nucleating agent is a substituted aromatic heterocyclic phosphate α nucleating agent. Further, the nucleating agent is 2,2'-methylene bis (4,6-di-tert-butylphenyl) sodium phosphate, such as NA-11 of Japan Aidico.

[0078] In one embodiment, the polypropylene-based composite material further comprises one or more of a filler, an antioxidant and a lubricant. The filler is matched with the alkali-free glass fiber to give the material balanced mechanical properties and significantly improve the surface floating fiber. The antioxidant can enhance the stability of the composite material. The lubricant can play a role in lubrication, improving dispersibility and demoulding properties.

[0079] In one embodiment, the polypropylene-based composite material further comprises 10 to 20 parts of filler, including but not limited to 10 parts, 12 parts, 15 parts, 16 parts, 18 parts and 20 parts by weight.

[0080] In one embodiment, the filler is selected from one or a mixture of nano barium sulfate, nano talc and titanium dioxide.

[0081] In one embodiment, the polypropylene-based composite material further comprises 0.2 to 0.5 parts of antioxidants, including but not limited to 0.2, 0.3, 0.4 and 0.5 parts, preferably 0.2 to 0.5 parts, by weight.

[0082] In one embodiment, the antioxidant is selected from one or a mixture of tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] pentaerythritol ester (antioxidant 1010) and tris[2,4-di-tert-butylphenyl]phosphite (antioxidant 168). Preferably, the antioxidant is a mixture of the two.

[0083] In one embodiment, the polypropylene-based composite material further includes 0.1 to 0.5 parts of lubricant, including but not limited to 0.1 parts, 0.2 parts, 0.3 parts, 0.4 parts and 0.5 parts by weight.

[0084] In one embodiment, the lubricant is one or a mixture of calcium stearate, N,N'-ethylene bisstearamide, erucic acid amide.

[0085] The present invention also provides a method for preparing the polypropylene-based composite material as described above, comprising the following steps:

[0086] The polypropylene resin, maleic anhydride grafted polymer, alkali-free glass fiber, aminosilane oligomer, initiator, flame retardant, synergistic flame retardant and nucleating agent are mixed, melted and extruded.

[0087] In one embodiment, the method for preparing the polypropylene-based composite material comprises the following steps:

[0088] The polypropylene resin, the maleic anhydride grafted polymer, the alkali-free glass fiber, the aminosilane oligomer, the initiator, the flame retardant, the synergistic flame retardant and the nucleating agent are mixed to obtain a mixture;

[0089] The mixture is melt-extruded, and then water-cooled, air-dried, pelletized and dried.

[0090] In one embodiment, the melt extrusion temperature is 160° C. to 200° C. This processing temperature can prevent the decomposition of the flame retardant with a low decomposition temperature and avoid excessive thermal oxidative aging of the PP resin.

[0091] In one embodiment, a twin-screw extruder is used for melt extrusion, and the barrel of the twin-screw extruder is a ten-section barrel, the first section of the barrel is connected to the main feeding device, the sixth section of the barrel is vented, and the ninth section of the barrel is vacuumed; the barrel temperature is set as: the first section of the barrel is not heated, the second section of the barrel is 180±5℃, the third section of the barrel is 180±5℃, the fourth section of the barrel is 180±5℃, the fifth section of the barrel is 180±5℃, the sixth section of the barrel is 170±5℃, the seventh section of the barrel is 170±5℃, the eighth section of the barrel is 170±5℃, the ninth section of the barrel is 170±5℃, the tenth section of the barrel is 170±5℃, and the head is 200±5℃.

[0092] In one embodiment, the drying temperature is 70-90° C. and the drying time is 2-5 hours.

[0093] It can be understood that for a composite material containing other components (such as a filler, an antioxidant or a lubricant), they can be directly mixed together when preparing the mixture.

[0094] The present invention also provides the use of the polypropylene-based composite material described above in the preparation of electronic appliances or automobiles. The electronic appliances include but are not limited to household appliances and industrial appliances.

[0095] The present invention also provides a lighting fixture, which comprises the polypropylene-based composite material as described above.

[0096] The following is a specific embodiment, and the manufacturers and models of the main raw materials of the present invention are as follows:

[0097] The proportions and percentages of the components in the embodiments are based on mass, and the components are described as follows: A is PP resin: copolymerized PP resin, Sinopec K7726H;

[0098] B is maleic anhydride grafted product:

[0099] B1 PP-g-MAH, CMG-5001, grafting rate 0.5% to 1%, Shanghai Jiayirong;

[0100] B2 PP-g-MAH, PC-1-1, grafting rate 1.0% to 1.5%, Foshan Bochen;

[0101] B3 POE-g-MAH, CMG5805L, grafting rate 1.0% to 1.5%, Shanghai Jiayirong; C is filler:

[0102] C1 titanium dioxide CR210;

[0103] C2 Nano-barium sulfate F300A Foshan Anyi;

[0104] D is alkali-free glass fiber:

[0105] E-type short glass fiber 248A produced by OC Company;

[0106] E is a flame retardant:

[0107] Octabromoether XZ-6800 Shandong Brothers;

[0108] F is a synergistic flame retardant:

[0109] Antimony trioxide Hunan Chenzhou Antimony Industry;

[0110] G is the initiator:

[0111] Lianku Guangzhou Xijia Chemical;

[0112] H is an antioxidant:

[0113] It is compounded by antioxidant 1010 and antioxidant 168 in a mass ratio of 1:1; I is a lubricant:

[0114] CaSt2

[0115] J is a nucleating agent:

[0116] Phosphate nucleating agent NA-11 Japan Aidico;

[0117] K is an aminosilane oligomer:

[0118] Aminosilane oligomer SIC6651 Guangzhou Siloke.

[0119] Preparation method of polypropylene-based composite material: Examples 1 to 7 and Comparative Examples 1 to 4 were weighed and prepared according to Table 1, PP particles and aminosilane oligomer modifier were mixed with a high-speed mixer for 2 minutes, and then the formula components other than fillers were mixed with a high-speed mixer for 3 minutes. After mixing evenly, the remaining fillers were added and mixed for 5 minutes to obtain a uniform mixture. The above mixture was put into a twin-screw extruder for melt extrusion and granulation.

[0120] Table 1 Formula table of each embodiment and comparative example

[0121]

[0122] The polypropylene-based composite materials prepared in Examples 1 to 7 and Comparative Examples 1 to 4 were molded into standard test specimens according to national standards and subjected to mechanical property related tests.

[0123] The notched impact test is carried out in accordance with the national standard GB / T 1843.

[0124] The tensile test is carried out in accordance with the national standard GB / T 1040.

[0125] The bending test is carried out in accordance with the national standard GB / T 9341.

[0126] The thermal deformation (0.45MPa / 4.0mm) test is carried out in accordance with the national standard GB / T1634.

[0127] The flame retardant performance is tested according to the UL94 (1.6mm) flammability test standard.

[0128] The resistance to n-hexane wiping is tested in accordance with the test method for liquid ink adhesion fastness of GB / T13217.7, and n-hexane is specially selected for wiping.

[0129] The test results of Examples 1 to 7 and Comparative Examples 1 to 4 are shown in Table 2.

[0130] Table 2 Test results of various embodiments and comparative examples

[0131]

[0132] As can be seen from Table 1 and Table 2, the composite materials provided by Examples 1 to 7 of the present invention have good printability, mechanical properties, heat resistance and flame retardant properties, and are suitable for injection molding. Comparative Example 1 Compared with Example 1, the initiator is omitted, and the composite material has good resistance to n-hexane wiping, but it is still slightly reduced, and the flame retardant property is significantly reduced. This is because the oily silane modifier is also a flammable substance when giving the material surface good polarity, and the flame retardant system can meet the flame retardant and printability of the material by improving the flame retardant system by the initiator. Comparative Example 2 Compared with Example 2, the initiator and aminosilane oligomer are omitted at the same time, and the n-hexane wiping resistance of the composite material is significantly reduced, which shows that aminosilane oligomers, a small molecule auxiliary agent with both polar and non-polar groups, have a positive effect on improving the surface polarity of the material and improving printability. Comparative Example 3 Compared with Example 3, after omitting the maleic anhydride grafted polymer and alkali-free glass fiber, the rigidity and heat resistance of the composite material are greatly reduced, because the glass fiber can not only give the PP material an improvement in rigidity, but also significantly improve the heat resistance. Compared with Example 5, after the synergistic flame retardant and nucleating agent were omitted in Comparative Example 4, the flame retardancy, heat resistance and mechanical properties of the composite material were significantly reduced, which shows that antimony trioxide as a synergistic flame retardant plays an important role in the flame retardancy of the material system. At the same time, the addition of the nucleating agent can effectively improve the crystallization performance of the material, thereby improving the heat resistance of the material and maintaining a certain rigidity, thereby improving the production molding efficiency.

[0133] Figure 1 This is the effect picture of the polypropylene-based composite material prepared in Comparative Example 2 after printing and wiping it with n-hexane 10 times. Obvious scratches can be seen, indicating that the printability is very poor. Figure 2 This is the effect picture of the polypropylene-based composite material prepared in Example 2 after printing and wiping it 100 times with n-hexane. Slight scratches can be seen, indicating that the printability is very good. Figure 1 and Figure 2 It can be seen that when the initiator and aminosilane oligomer are omitted at the same time, the n-hexane wiping resistance of the composite material is significantly reduced. This shows that aminosilane oligomer, a small molecule additive with both polar and non-polar groups, has a positive effect on improving the surface polarity of the material and enhancing printability.

[0134] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0135] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A polypropylene-based composite material, characterized in that: It is composed of the following components in parts by weight: 30-55 parts of polypropylene resin; 5 to 30 parts of maleic anhydride grafted polymer; 15-20 parts of alkali-free glass fiber; 3-5 parts of aminosilane oligomer; 0.3-0.5 parts of initiator; 4-6 parts of flame retardant; 1.5-2 parts of synergistic flame retardant; Nucleating agent 0.3-0.5 parts; 10-15 parts of filler; 0.2-0.5 parts of antioxidant; Lubricant 0.1-0.5 parts; The alkali-free glass fiber is a chopped glass fiber, and the diameter of the alkali-free glass fiber is 9µm to 15µm, and the length is 3mm to 5mm; The grafting rate of the maleic anhydride grafted polymer is ≥ 0.1%; the maleic anhydride grafted polymer is selected from one or more of maleic anhydride grafted polypropylene, maleic anhydride grafted polyethylene and maleic anhydride grafted polyolefin elastomer; The initiator is 2,3-dimethyl-2,3-diphenylbutane; The flame retardant is a bromine-containing compound; The synergistic flame retardant is an antimony-containing compound; The aminosilane oligomer is selected from a mixture of one or more of a monoaminosilane oligomer and a bisaminosilane oligomer; The nucleating agent is a substituted aromatic heterocyclic phosphate α nucleating agent; The filler is selected from a mixture of one or more of nano barium sulfate, nano talc and titanium dioxide; The lubricant is a mixture of one or more of calcium stearate, N,N'-ethylene bisstearamide and erucamide.

2. The polypropylene-based composite material according to claim 1, characterized in that: It is composed of the following components in parts by weight: 30.8 parts of polypropylene resin; 25 parts of maleic anhydride grafted polymer; 15 parts of alkali-free glass fiber; 5 parts of aminosilane oligomer; 0.5 part of initiator; 6 parts of flame retardant; 2 parts of synergistic flame retardant; 0.5 parts of nucleating agent; 15 parts of filler; 0.3 parts of antioxidant; and 0.5 parts of lubricant.

3. The polypropylene-based composite material according to claim 1, characterized in that: The flame retardant is selected from one or a mixture of octabromoether, octabromosulfide, hexabromocyclododecane and tris(2,3-dibromopropyl)isocyanurate.

4. The polypropylene-based composite material according to claim 1, characterized in that: The synergistic flame retardant is selected from antimony trioxide and antimony pentoxide, or a mixture of the two.

5. The polypropylene-based composite material according to claim 1, characterized in that: At 230° C. / 2.16 Kg, the melt flow rate of the polypropylene resin is ≥20 g / 10 min.

6. The polypropylene-based composite material according to claim 1, characterized in that: The grafting rate of the maleic anhydride grafted polymer is 0.5% to 1.5%.

7. The polypropylene-based composite material according to claim 1, characterized in that: The alkali-free glass fiber has a diameter of 11µm to 13µm and a length of 3mm to 4.5mm.

8. The polypropylene-based composite material according to claim 1, characterized in that: The antioxidant is selected from one or a mixture of tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]pentaerythritol ester and tris[2,4-di-tert-butylphenyl]phosphite.

9. A method for preparing the polypropylene-based composite material according to any one of claims 1 to 8, characterized in that: The following steps are involved: The polypropylene resin, maleic anhydride grafted polymer, alkali-free glass fiber, aminosilane oligomer, initiator, flame retardant, synergistic flame retardant, nucleating agent, filler, antioxidant and lubricant are mixed, melted and extruded.

10. Use of the polypropylene-based composite material according to any one of claims 1 to 8 in the preparation of electronic appliances or automobiles.

11. A lighting decoration, characterized in that: The invention comprises the polypropylene-based composite material according to any one of claims 1 to 8 or the polypropylene-based composite material prepared according to the preparation method according to claim 9.

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