A kind of anti-aging, flame-retardant polypropylene composite material and its preparation method and application

Abstract

The present invention belongs to the technical field of polymer modified materials, and specifically relates to an aging-resistant, flame-retardant polypropylene composite material, and a preparation method and application thereof. The aging-resistant, flame-retardant polypropylene composite material of the present invention comprises the following raw materials in parts by weight: 20 to 60 parts of polypropylene resin; 1 to 10 parts of compatibilizer; 5 to 25 parts of EPDM rubber recycled material; 5 to 30 parts of smoke suppression flame retardant; 0.1 to 2 parts of light stabilizer; 0.1 to 2 parts of antioxidant; 10 to 40 parts of glass fiber. The aging-resistant, flame-retardant polypropylene composite material of the present invention has excellent mechanical properties, as well as light and heat aging resistance; tensile strength>85MPa, bending modulus>6000MPa, cantilever beam notched impact strength>165J / m, and strength is higher than that of wood. The injection-molded building formwork will not break when it falls vertically from a height of 3m, and can reach the B2 level of combustion performance of building materials and their products.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer modified materials, and specifically relates to an aging-resistant, flame-retardant polypropylene composite material and a preparation method and application thereof. Background Art

[0002] Polypropylene (PP) is one of the five general-purpose resins. It has excellent properties such as light weight, easy processing, and chemical corrosion resistance. It is widely used in chemical, electrical, packaging and other industrial fields. However, polypropylene itself still has many defects and needs to be modified to meet the needs of more application fields. Among them, glass fiber reinforced polypropylene is an important modification method, which enables it to "replace steel with plastic" and "replace wood with plastic".

[0003] The existing construction formwork is generally made of wooden boards. The disadvantage of this operation is that a large amount of wood needs to be cut down, and the wooden boards spliced ​​with nails are easily damaged and need to be constantly repaired. This requires the development of a new formwork material to replace the existing wooden board formwork for application in the construction industry, so that it has high strength, good impact resistance, and is not easily damaged by falling. However, the problems of warping, non-flame retardancy and aging resistance of glass fiber reinforced polypropylene injection molding need to be solved.

[0004] Therefore, developing a glass fiber reinforced flame retardant polypropylene material that can pass the GB8624-2012 construction industry standard B2 level and has good aging resistance and formability is a technical problem that needs to be solved at present. Summary of the invention

[0005] The present invention aims to solve at least one of the technical problems existing in the above-mentioned prior art. To this end, the present invention proposes an aging-resistant and flame-retardant polypropylene composite material, which has excellent mechanical strength, good impact resistance, good light resistance and heat aging resistance, can be used as a building formwork material, is not easily damaged by falling, and passes the test of GB8624-2012 building industry standard B2 level.

[0006] The first aspect of the present invention provides an anti-aging, flame-retardant polypropylene composite material, comprising the following raw materials in parts by weight:

[0007] 20-60 parts of polypropylene resin;

[0008] 1 to 10 parts of compatibilizer;

[0009] 5-25 parts of EPDM recycled materials;

[0010] 5-30 parts of smoke suppression and flame retardant;

[0011] Light stabilizer 0.1-2 parts;

[0012] 0.1-2 parts of antioxidant;

[0013] 10-40 parts of glass fiber.

[0014] According to the first aspect of the present invention, there are at least the following beneficial effects:

[0015] The present invention adopts a compatibilizer, a smoke suppressant and a flame retardant, and EPDM rubber recycled materials in suitable proportions, and is matched with a light stabilizer, an antioxidant and glass fiber. The components work synergistically to obtain an aging-resistant and flame-retardant polypropylene composite material with excellent mechanical properties and impact resistance, is not easily damaged by falling from a height, has good light and heat aging resistance, and can reach the B2 level of the combustion performance grade of building materials and their products.

[0016] In some preferred embodiments of the present invention, the aging-resistant and flame-retardant polypropylene composite material comprises the following raw materials in parts by weight:

[0017] 30-45 parts of polypropylene resin;

[0018] 2 to 6 parts of compatibilizer;

[0019] 10-15 parts of EPDM recycled materials;

[0020] 10-20 parts of composite smoke suppression flame retardant;

[0021] Light stabilizer 0.2-0.6 parts;

[0022] 0.2-0.6 parts of antioxidant;

[0023] 25-30 parts of glass fiber.

[0024] In some more preferred embodiments of the present invention, the anti-aging and flame-retardant polypropylene composite material comprises the following raw materials in parts by weight:

[0025] 30-40 parts of polypropylene resin;

[0026] 4-6 parts of compatibilizer;

[0027] 10-15 parts of EPDM recycled materials;

[0028] 10-15 parts of composite smoke suppression flame retardant;

[0029] Light stabilizer 0.4-0.6 parts;

[0030] 0.4-0.6 parts of antioxidant;

[0031] 25-30 parts of glass fiber.

[0032] In some preferred embodiments of the present invention, the anti-aging and flame-retardant polypropylene composite material further comprises the following raw materials in parts by weight:

[0033] 0.2-0.8 parts of hydrotalcite;

[0034] Lubricant 0.2-0.8 parts.

[0035] In some preferred embodiments of the present invention, the anti-aging and flame-retardant polypropylene composite material further comprises the following raw materials in parts by weight:

[0036] 0.4-0.6 parts of hydrotalcite;

[0037] Lubricant 0.4-0.6 parts.

[0038] In the present invention, hydrotalcite is an anionic layered compound. By utilizing the intercalation property of the layered compound body and the exchangeability of interlayer ions under the action of strong polar molecules, some functional guest substances can be introduced into the interlayer gaps and the distance between the layers can be expanded to form a layered column compound. During the thermal oxidative aging process, some decomposed free radicals can be adsorbed, thereby slowing down the aging process.

[0039] In some embodiments of the present invention, the EPDM rubber is a copolymer of ethylene, propylene and a small amount of a third monomer which is a non-conjugated diene; the EPDM rubber recycled material has a third monomer ethylidene norbornene content of ≥2%, preferably a mass content of ethylidene norbornene of ≥4%. In the present invention, the EPDM rubber with a higher third monomer ethylidene norbornene content has a lower compression deformation, and the EPDM rubber with a high ethylene content has good aging resistance and impact properties, high Mooney viscosity, good fluidity, and is suitable for injection molding.

[0040] In some preferred embodiments of the present invention, the polypropylene resin is a high-fluidity high-crystalline polypropylene, the melt index of the polypropylene resin (tested according to ASTM D1238 at 230°C, 2.16Kg)>60g / 10min; more preferably, the melt index of the polypropylene resin (tested according to ASTM D1238 at 230°C, 2.16Kg)>80g / 10min; the flexural modulus of the polypropylene resin (ASTM D790)>1200MPa, more preferably, the flexural modulus of the polypropylene resin (ASTMD790)>1500MPa. The present invention uses a high-fluidity high-crystalline polypropylene resin, which can reduce the film filling resistance, make the injection molding of large parts better, and is not prone to glue shortage. It has high crystallinity, can shorten the molding cooling time, and improve efficiency; a higher flexural modulus can improve the deformation resistance and load-bearing capacity.

[0041] In some preferred embodiments of the present invention, the compatibilizer includes ethylene-butene copolymer (POE) grafted maleic anhydride, a more preferred compatibilizer is ethylene-butene copolymer (POE) grafted maleic anhydride with a grafting rate of ≥1%, and a further preferred compatibilizer is ethylene-butene copolymer (POE) grafted maleic anhydride with a grafting rate of ≥0.8%. The present invention uses POE compatibilizer, which can be used as a compatibilizer for glass fiber and polypropylene resin, and can also improve the impact strength of polypropylene composite materials, and can be used as a building formwork material.

[0042] In some preferred embodiments of the present invention, the smoke suppressant and flame retardant is a composite smoke suppressant and flame retardant, including chemical magnesium hydroxide and hydrated zinc borate (3.5 hydrated zinc borate); the mass ratio of the chemical magnesium hydroxide to hydrated zinc borate is 1 to 3:1, more preferably 1.5 to 2.5:1, including but not limited to 1.5:1, 2:1, 2.5:1, etc.

[0043] In the present invention, in the construction site, the existing building formwork board is mostly wood, which has poor flame retardancy or even no flame retardancy, and the falling of cigarette butts or arc welding residues can easily lead to spontaneous combustion, thereby causing a fire. The present invention adopts a smoke suppression flame retardant compounded with chemical magnesium hydroxide and hydrated zinc borate. As an inorganic flame retardant with high economic benefits, chemical magnesium hydroxide has the characteristics of suppressing smoke and absorbing heat (about 350°C) to produce decomposition water. The released water dilutes the combustible gas and delays the fire. As a flame retardant, hydrated zinc borate can not only flame retardant, but also eliminate smoke and extinguish arcs, which can effectively improve the flame retardant performance and reduce the generation of smoke during combustion. The decomposition temperature of hydrated zinc borate is relatively high, and when combined with magnesium hydroxide, different gradients of delaying fire or self-extinguishing effects can be formed.

[0044] In some preferred embodiments of the present invention, the light stabilizer is a compound light stabilizer, including light stabilizer 622 and light stabilizer 228; the mass ratio of the light stabilizer 622 to the light stabilizer 228 is 1:1-3, more preferably 1:1.5-2.5, including but not limited to 1:1.5, 1:2, 1:2.5, etc.

[0045] In the present invention, since the light stabilizer UV622 is a weakly alkaline polymerized high molecular weight hindered amine light stabilizer, it has good processing thermal stability and good compatibility with polypropylene, and can effectively prevent the degradation of polypropylene by light, heat climate and moisture. During the light aging process, polypropylene is degraded and presents an acidic environment. If too much alkaline light stabilizer is used, the light aging resistance effect cannot be achieved. When used with the neutral hindered amine ultraviolet light stabilizer 228, this problem can be perfectly solved, so that the material can achieve a long-term light aging resistance effect.

[0046] In some preferred embodiments of the present invention, the antioxidant is a compound antioxidant, including antioxidant 168, antioxidant 1010, and antioxidant DSTDP; the mass ratio of the antioxidant 168: antioxidant 1010: antioxidant DSTDP is 1-3:1:2-4, more preferably 1.5-2.5:1:2-3, and further preferably about 2:1:2.5.

[0047] In the present invention, adding a compound antioxidant can improve the aging resistance of glass fiber reinforced polypropylene materials. Antioxidants 168 and 1010 are conventional antioxidants, which can not only protect polypropylene (PP) from degradation during processing, but also make the material have long-term aging resistance. The compound thioester antioxidant DSTDP has a synergistic effect with antioxidant 1010, can prevent the thermal oxidation aging degradation of polypropylene materials in the long-term aging process, has a long effectiveness, and has high economy.

[0048] In some preferred embodiments of the present invention, the glass fiber (glass fiber) is a chopped glass fiber, the wire diameter (also known as the diameter) of the glass fiber is 5 to 20 μm, more preferably 8 to 12 μm, and further preferably about 10 μm; the length of the glass fiber is 2 to 10 mm, more preferably 4 to 7 mm, and further preferably about 5 mm. In the present invention, due to the presence of the composite smoke suppression flame retardant, the dispersion of the glass fiber is additively affected, but the inorganic flame retardant has a certain grinding effect on the glass fiber, so it is necessary to select chopped glass fibers with better performance. The inorganic flame retardant can also reduce the orientation of the glass fiber, so that the injection molded parts are not easy to warp.

[0049] In some preferred embodiments of the present invention, the lubricant includes at least one of polyethylene wax, oxidized polyethylene wax, stearic acid, and calcium stearate, and the more preferred lubricant includes polyethylene wax. In the present invention, the use of polyethylene wax can improve the internal and external lubricity of the material, increase the dispersibility of the glass fiber, improve the surface brightness of the material, and take into account the economic efficiency.

[0050] The second aspect of the present invention provides a method for preparing the aging-resistant and flame-retardant polypropylene composite material, comprising the following steps:

[0051] The raw materials of the aging-resistant and flame-retardant polypropylene composite material are mixed and melt-extruded to obtain the aging-resistant and flame-retardant polypropylene composite material.

[0052] In some preferred embodiments of the present invention, the preparation method of the aging-resistant and flame-retardant polypropylene composite material comprises the following steps: mixing polypropylene resin, compatibilizer, compound smoke suppression flame retardant, EPDM rubber recycled material, light stabilizer, antioxidant, hydrotalcite, and lubricant, adding them from the main feed port of the extruder, adding chopped glass fibers from the side feed port, and melt-extruding to obtain the aging-resistant and flame-retardant polypropylene composite material.

[0053] In some preferred embodiments of the present invention, the melt extrusion temperature is 200-230°C, and a more preferred melt extrusion temperature is 200°C / 220°C / 220°C / 220°C / 225°C / 225°C / 225°C / 230°C / 230°C / 230°C / 210°C.

[0054] In some preferred embodiments of the present invention, the screw combination used in the extruder is independently designed, and the screw design parameters of the screw combination from the exhaust port to the discharge film head end are 96 / 96, 96 / 96, 72 / 72, 72 / 72, 56 / 56, 45° / 5 / 56, transition block 12 / 12, tooth group 57 / 57, transition block 12 / 12, 72 / 72, 56 / 56, transition block 12 / 12, tooth group 57 / 57, transition block 12 / 12, 72 / 72, 56 / 56, 56 / 56, 56 / 28L, 96 / 96, 96 / 96, 96 / 96, 72 / 72, 72 / 72, 56 / 56, 56 / 56, 56 / 56, 56 / 56, 56 / 56. For example, "96 / 96" means that this is a threaded block with a lead of 96mm and a length of 96mm; "45° / 5 / 56" means that 45° represents the angle of the kneading block, 5 is the number of pieces, and 56 is the length; "Transition block 12 / 12" is a link block between the toothed disk and the threaded block or shear block, and its length is 12mm; "Tooth group 57 / 57" means that the length of the toothed threaded element is 57mm; "56 / 28L" means that 56 refers to the lead of the conveying block, 28 represents the length of this conveying block, and L represents the direction. The others are just length changes, and the meanings are similar.

[0055] The third aspect of the present invention proposes the use of the aging-resistant and flame-retardant polypropylene composite material in the preparation of building formwork materials. The aging-resistant and flame-retardant polypropylene composite material disclosed in the present invention can replace wood boards as building formwork materials.

[0056] Compared with the prior art, the present invention has at least the following beneficial effects:

[0057] 1. The aging-resistant and highly flame-retardant polypropylene composite material of the present invention has excellent mechanical properties, with tensile strength>85MPa, flexural modulus>6000MPa, and cantilever beam notched impact strength>165J / m. The strength is higher than that of wood, and the injection-molded building formwork will not break when dropped vertically from a height of 3m.

[0058] 2. The aging-resistant and flame-retardant polypropylene composite material of the present invention has excellent aging resistance. After being baked at 150°C for 1000 hours, the tensile strength, flexural modulus and cantilever beam notched impact strength are all maintained above 70%. After being irradiated with UV for 1500 hours, the tensile strength, flexural modulus and cantilever beam notched impact strength are all maintained above 70%.

[0059] 3. The aging-resistant and flame-retardant polypropylene composite material of the present invention passes the B2 level test (combustible material) of the GB8624-2012 construction industry standard and has the effects of suppressing smoke and delaying fire.

[0060] 4. The surface of the aging-resistant and flame-retardant polypropylene material of the present invention is relatively smooth without obvious warping.

[0061] 5. The preparation method of the present invention is relatively simple, easy to realize large-scale production, low cost, uses a self-designed screw assembly, the material has high mechanical properties, and the product quality is stable. DETAILED DESCRIPTION

[0062] The following will be combined with the embodiments to clearly and completely describe the concept of the present invention and the technical effects produced, so as to fully understand the purpose, characteristics and effects of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, other embodiments obtained by those skilled in the art without creative work are all within the scope of protection of the present invention.

[0063] The raw materials used in the following examples, unless otherwise specified, can be obtained from conventional commercial sources; the processes used, unless otherwise specified, are conventional processes in the art; the operating temperatures used, unless otherwise specified, are room temperature (20±5° C.).

[0064] Example 1

[0065] This embodiment prepares an aging-resistant glass fiber reinforced flame-retardant polypropylene composite material, which is specifically implemented as follows:

[0066] According to the proportion, 38 parts of the polypropylene resin (SK, BX3920, South Korea, MI is 100g / 10min, the test conditions are 2.16Kg, 230℃), 5 parts of POE grafted maleic anhydride (Coais Chemical Co., Ltd., plastic additive: W1), 15 parts of compound smoke suppression flame retardant (chemical method magnesium hydroxide: 3.5 water zinc borate = 2:1), 10 parts of EPDM rubber black recycled particles (commercially available, the third monomer ethylidene norbornene content is 5%, the ratio of ethylene to propylene is 70: 30, Mooney viscosity 60MU), 0.5 parts of compound light stabilizer (light stabilizer 622: light stabilizer 228 = 1:2, commercially available), 0.5 parts of polyethylene wax (Qingdao Bangni, BN500), 0.5 parts of hydrotalcite (commercially available), 0.5 parts of compound antioxidant (antioxidant 168: antioxidant 1010: antioxidant DSTDP = 2:1:2.5, commercially available) are mixed evenly according to the proportion, fed into the twin-screw extruder from the main feed, and 25 parts of short-cut glass fiber (TCR) are added from the side feed port. 438G-13-4.5, Chongqing composite materials), extrusion granulation is carried out in a self-designed screw combination to obtain an aging-resistant glass fiber reinforced polypropylene material; the extrusion temperature of the extrusion granulation is 200℃ / 220℃ / 220℃ / 220℃ / 225℃ / 225℃ / 225℃ / 230℃ / 230℃ / 230℃ / 210℃, and the self-designed screw combination is 96 / 96, 96 / 96, 72 / 72, 72 from the side feed port to the discharge die end. / 72, 56 / 56, 45° / 5 / 56, transition block 12 / 12, tooth group 57 / 57, transition block 12 / 12, 72 / 72, 56 / 56, transition block 12 / 12, tooth group 57 / 57, transition block 12 / 12, 72 / 72, 56 / 56, 56 / 56, 56 / 28L, 96 / 96, 96 / 96, 96 / 96, 72 / 72, 72 / 72, 56 / 56, 56 / 56, 56 / 56, 56 / 56, 56 / 56.

[0067] Example 2

[0068] This embodiment prepares an aging-resistant glass fiber reinforced flame-retardant polypropylene composite material, which is specifically implemented as follows:

[0069] According to the proportion, 33 parts of the polypropylene resin (SK, BX3920, South Korea, MI is 100g / 10min, the test conditions are 2.16Kg, 230℃), 5 parts of POE grafted maleic anhydride (Coais Chemical Co., Ltd., plastic additive: W1), 15 parts of compound smoke suppression flame retardant (chemical method magnesium hydroxide: 3.5 water zinc borate = 2:1), 15 parts of EPDM rubber black recycled particles (commercially available, the third monomer ethylidene norbornene content is 5%, the ratio of ethylene to propylene is 70: 30, Mooney viscosity 60MU), 0.5 parts of compound light stabilizer (light stabilizer 622: light stabilizer 228 = 1:2, commercially available), 0.4 parts of polyethylene wax (Qingdao Bangni, BN500), 0.5 parts of hydrotalcite (commercially available), 0.5 parts of compound antioxidant (antioxidant 168: antioxidant 1010: antioxidant DSTDP = 2:1:2.5, commercially available) are mixed evenly according to the proportion, fed into the twin-screw extruder from the main feed, and 30 parts of chopped glass fiber (TCR) are added from the side feed port. 438G-13-4.5, Chongqing composite materials), extrusion granulation is carried out in a self-designed screw combination to obtain an aging-resistant glass fiber reinforced polypropylene material; the extrusion temperature of the extrusion granulation is 200℃ / 220℃ / 220℃ / 220℃ / 225℃ / 225℃ / 225℃ / 230℃ / 230℃ / 230℃ / 210℃, and the self-designed screw combination is 96 / 96, 96 / 96, 72 / 72, 72 from the side feed port to the discharge die end. / 72, 56 / 56, 45° / 5 / 56, transition block 12 / 12, tooth group 57 / 57, transition block 12 / 12, 72 / 72, 56 / 56, transition block 12 / 12, tooth group 57 / 57, transition block 12 / 12, 72 / 72, 56 / 56, 56 / 56, 56 / 28L, 96 / 96, 96 / 96, 96 / 96, 72 / 72, 72 / 72, 56 / 56, 56 / 56, 56 / 56, 56 / 56, 56 / 56.

[0070] Comparative Example 1

[0071] In this comparative example, a glass fiber reinforced flame retardant polypropylene composite material was prepared. The main difference from Example 1 is that the polypropylene resin (SK, BX3920, Korea, MI is 100g / 10min, the test conditions are 2.16Kg, 230°C) is changed to polypropylene resin (EP548R, CNOOC Shell, MI is 28g / 10min, the test conditions are 2.16Kg, 230°C), the raw material proportions are shown in Table 1, and the preparation process refers to Example 1.

[0072] Comparative Example 2

[0073] In this comparative example, a glass fiber reinforced flame retardant polypropylene composite material is prepared. The main difference from Example 1 is that the compatibilizer (POE grafted maleic anhydride) is changed to PP grafted maleic anhydride (KT-1, Shenyang Ketong). The raw material proportions are shown in Table 1, and the preparation process refers to Example 1.

[0074] Comparative Example 3

[0075] In this comparative example, a glass fiber reinforced flame retardant polypropylene composite material is prepared. The main difference from Example 1 is that 10 parts of black recycled EPDM rubber particles are replaced with 10 parts of polypropylene resin (SK, BX3920 from South Korea). The raw material proportions are shown in Table 1, and the preparation process refers to Example 1.

[0076] Comparative Example 4

[0077] In this comparative example, a glass fiber reinforced polypropylene composite material is prepared. The main difference from Example 1 is that 15 parts of the compound smoke suppression flame retardant (chemical magnesium hydroxide: 3.5 zinc borate water = 2:1) is replaced with 15 parts of polypropylene resin (SK, BX3920 from South Korea). The raw material proportions are shown in Table 1, and the preparation process refers to Example 1.

[0078] Comparative Example 5

[0079] In this comparative example, a glass fiber reinforced polypropylene composite material was prepared. The main difference from Example 2 is that the compounded light stabilizer 0.5 parts (light stabilizer 622: light stabilizer 228 = 1:2, commercially available) was changed to 0.5 parts of light stabilizer (light stabilizer 622). The raw material proportions are shown in Table 1. The preparation process refers to Example 2.

[0080] Comparative Example 6

[0081] In this comparative example, a glass fiber reinforced polypropylene composite material was prepared. The main difference from Example 2 is that 0.5 parts of hydrotalcite (commercially available) was replaced with 0.5 parts of polypropylene resin (SK, BX3920, South Korea). The raw material proportions are shown in Table 1. The preparation process refers to Example 2.

[0082] Comparative Example 7

[0083] In this comparative example, a glass fiber reinforced polypropylene composite material is prepared. The main difference from Example 2 is that 0.5 parts of the compound antioxidant (antioxidant 168: antioxidant 1010: antioxidant DSTDP = 2:1:2.5, commercially available) is changed to 0.5 parts of antioxidant B215. The raw material proportions are shown in Table 1. The preparation process refers to Example 2.

[0084] Comparative Example 8

[0085] This comparative example prepares a glass fiber reinforced polypropylene material, which is mainly different from Example 1 in that the screw combination designed independently (the screw designs from the side feed port to the discharge die end are 96 / 96, 96 / 96, 72 / 72, 72 / 72, 56 / 56, 45° / 5 / 56, transition block 12 / 12, tooth group 57 / 57, transition block 12 / 12, 72 / 72, 56 / 56, transition block 12 / 12, tooth group 57 / 57, transition block 12 / 12, 72 / 72, 56 / 56, 56 / 56, 56 / 28L, 96 / 96, 96 / 96, 96 / 96, 72 / 72, 72 / 72, 56 / 56, 56 / 56, 56 / 56, The screw combinations commonly used for ordinary materials in this field are replaced by 96 / 96, 96 / 96, 72 / 72, 72 / 72, 56 / 56, 45° / 5 / 56, 60° / 4 / 56, 45° / 5 / 56, 72 / 72, 56 / 56, 45° / 5 / 56, 60° / 4 / 56, 56 / 56, 56 / 56, 56 / 28L, 96 / 96, 96 / 96, 96 / 96, 72 / 72, 72 / 72, 56 / 56, 56 / 56, 56 / 56, 56 / 56, 56 / 56, and the others remain unchanged. The raw material proportions are shown in Table 1. The preparation process refers to Example 1.

[0086] Table 1 Raw material ratios of Examples 1 to 2 and Comparative Examples 1 to 8 (%)

[0087]

[0088] Compound light stabilizer: by mass ratio, light stabilizer 622: light stabilizer 228 = 1:2;

[0089] Compound antioxidant: by mass ratio, antioxidant 168: antioxidant 1010: antioxidant DSTDP = 2:1:2.5;

[0090] Compound smoke suppression flame retardant: by mass ratio, chemical magnesium hydroxide: 3.5 zinc borate = 2:1;

[0091] Chopped glass fiber: TCR438G-13-4.5.

[0092] Test example

[0093] The materials of Examples 1 to 2 and Comparative Examples 1 to 8 were injection molded using a horizontal injection molding machine to obtain standard samples. Molding process conditions: injection temperature (feeding port) 185 / 190 / 190 / 195°C (nozzle); injection pressure 55MPa; holding time 8s; cooling time 8s, and drying at 105°C for 2h before injection molding. Performance tests were carried out respectively, and the performance test standards are as follows. The results are shown in Table 2:

[0094] Melt index: tested according to ASTM D1238-2010 standard, 230℃, 2.16Kg, unit: g / 10min;

[0095] Tensile strength: tested according to ASTM D638-2010 standard, 3.0mm thick specimen, unit: MPa;

[0096] Bending performance: According to ASTM D790-2017 standard, thickness 3.0mm specimen, unit: MPa;

[0097] Izod notched impact performance: tested according to ASTM D256-2010 standard, 3.0mm thick specimen, unit: J / m;

[0098] High temperature aging test: The tensile specimens, bending specimens and cantilever beam notched impact specimens were placed in a 150°C oven for aging for 1000 hours to test various properties;

[0099] UV aging test: Place the tensile specimens, bending specimens and cantilever beam notched impact specimens in a UV box for 1500 hours to test various properties. Light source: UVA-340, light intensity: 0.76W, cycle conditions: 8h illumination (BPT: 60℃), 4h condensation (BPT: 50℃) (GB / T16422.3);

[0100] Drop test: Drop the molded building formwork (600mm*900mm) vertically from a height of 3m until it cracks, and count the number of drops;

[0101] Observe the injection molding condition: visually.

[0102] GB8624-2012 Combustion performance classification of building materials and products: Class B2.

[0103] Table 2 Performance test results

[0104]

[0105]

[0106] It can be seen from Table 2 that the aging-resistant glass fiber reinforced flame-retardant polypropylene composite materials of Examples 1 to 2 of the present invention have excellent mechanical properties. After aging at 150°C and after UV irradiation aging, the retention rates of various properties are all above 70%, the number of vertical drops also reaches more than 7 times without cracking, the injection molding effect is good, there is no warping, and the combustion performance grade of building materials and products reaches B2 level; however, the glass fiber reinforced flame-retardant polypropylene composite material of Comparative Example 1 has difficulty in injection molding and is prone to lack of glue due to the replacement of the PP substrate; the glass fiber reinforced flame-retardant polypropylene composite materials of Comparative Examples 2 to 3 have increased tensile strength and flexural modulus due to the replacement of the compatibilizer or the removal of the black recycled particles of EPDM rubber, but the impact strength is significantly reduced, resulting in a decrease in the number of vertical drops, and due to the strong rigidity, there is a slight deformation during injection molding; the glass fiber reinforced polypropylene composite material of Comparative Example 4 has only B3 level of combustion performance of building materials and products due to the removal of the compounded smoke suppression flame retardant, which belongs to a flammable material; In the glass fiber reinforced flame retardant polypropylene composite material of ratio 5, the light stabilizer 622 is used to replace the compound light stabilizer, resulting in the tensile strength and impact strength after UV aging being less than 70%, and the neutral hindered amine ultraviolet light stabilizer 228 is lacking. After UV irradiation, polypropylene is degraded and presents an acidic environment. If too much alkaline light stabilizer 622 is used, a better light aging resistance effect cannot be achieved, so the retention rate decreases; the glass fiber reinforced polypropylene materials of comparative examples 6 to 7 are not added with hydrotalcite, or the antioxidant B215 (a combination of antioxidants 168 and antioxidants 1010 in the industry) is used to replace the compound antioxidant. During the thermal oxidative aging process, the antioxidant DSTDP in the hydrotalcite or compound antioxidant is lacking, and the high temperature aging time cannot be extended, so the retention rate is significantly lower than that of Example 2; the glass fiber reinforced polypropylene composite material of comparative example 8 changes the screw combination, strengthens the shear strength of the combination, resulting in mechanical properties significantly lower than those of Example 1, and a reduction in the number of vertical drops.

[0107] It can be seen that compared with the comparative example, the aging-resistant glass fiber reinforced flame-retardant polypropylene material of the technical solution of the present invention is added with a suitable proportion of compatibilizer, compound smoke suppression flame retardant and EPDM rubber recycled particles, and is matched with lubricant, light stabilizer, compound antioxidant and chopped glass fiber. The synergistic effect of each component makes the aging-resistant glass fiber reinforced flame-retardant polypropylene material of the present invention have excellent mechanical strength, good impact resistance, not easy to be damaged by falling, good light and heat aging resistance, and reaches the B2 level of combustion performance grade of building materials and products.

[0108] The above is a detailed description of the embodiments of the present invention, but the present invention is not limited to the above embodiments. Various changes can be made within the knowledge of ordinary technicians in the relevant technical field without departing from the purpose of the present invention. In addition, the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

Claims

1. An aging-resistant, flame-retardant polypropylene composite material, characterized in that: The invention comprises the following raw materials in parts by weight: Polypropylene resin 20-60 parts; Compatibilizer 1~10 parts; 5~25 parts of EPDM recycled materials; 5~30 parts of smoke suppression and flame retardant; Light stabilizer 0.1~2 parts; Antioxidant 0.1~2 parts; Glass fiber 10~40 parts; 0.2-0.8 parts of hydrotalcite; Lubricant 0.2~0.8 parts; The smoke suppression flame retardant is a composite smoke suppression flame retardant, including chemical magnesium hydroxide and hydrated zinc borate; the mass ratio of the chemical magnesium hydroxide to hydrated zinc borate is 1-3:1; The light stabilizer is a compound light stabilizer, including light stabilizer 622 and light stabilizer 228; The polypropylene resin has a melt index of >60 g / 10 min when tested at 230° C. and 2.16 kg according to ASTM D1238; The antioxidant is a compound antioxidant, including antioxidant 168, antioxidant 1010, and antioxidant DSTDP; The compatibilizer includes ethylene butene copolymer grafted with maleic anhydride; The preparation method of the aging-resistant and flame-retardant polypropylene composite material comprises the following steps: The raw materials of the aging-resistant and flame-retardant polypropylene composite material are mixed and melt-extruded to obtain the aging-resistant and flame-retardant polypropylene composite material; The melt extrusion is carried out by an extruder; the screw design parameters of the screw combination of the extruder from the exhaust port to the head end of the discharge film are 96 / 96, 96 / 96, 72 / 72, 72 / 72, 56 / 56, 45° / 5 / 56, transition block 12 / 12, tooth group 57 / 57, transition block 12 / 12, 72 / 72, 56 / 56, transition block 12 / 12, tooth group 57 / 57, transition block 12 / 12, 72 / 72, 56 / 56, 56 / 56, 56 / 28L, 96 / 96, 96 / 96, 96 / 96, 72 / 72, 72 / 72, 56 / 56, 56 / 56, 56 / 56, 56 / 56, 56 / 56; among them, 96 / 96 means that this is a threaded block with a lead of 96mm and a length of 96mm; 45° / 5 / 56 means that 45° represents the angle of the kneading block, 5 is the number of pieces, and 56 is the length; the transition block 12 / 12 is a connecting block between the toothed disk and the threaded block or the shear block, and its length is 12mm; the tooth group 57 / 57 means that the length of the toothed threaded element is 57mm; 56 / 28L means that 56 refers to the lead of the conveying block, 28 represents the length of this conveying block, and L represents the direction; the other parameters only change in length, and the meanings they represent are similar.

2. The aging-resistant, flame-retardant polypropylene composite material according to claim 1, characterized in that: The ethylene propylene diene monomer recycled material has a content of ethylidene norbornene as the third monomer of ≥2%.

3. The method for preparing the aging-resistant and flame-retardant polypropylene composite material according to any one of claims 1 to 2, characterized in that: The steps include: The raw materials of the aging-resistant and flame-retardant polypropylene composite material are mixed and melt-extruded to obtain the aging-resistant and flame-retardant polypropylene composite material.

4. Use of the aging-resistant, flame-retardant polypropylene composite material according to any one of claims 1 to 2 in the preparation of building formwork materials.

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