High paint adhesion automobile thin-wall bumper material, preparation method and application thereof

Abstract

The present application relates to a kind of high paint adhesion automobile thin-wall bumper material, preparation method and its application, the material includes polypropylene, polyethylene, thermoplastic polyurethane elastomer, maleic anhydride grafting polyolefin and / or quaternary ammonium salt modified montmorillonite, filler, antioxidant, lubricant.The present application is by introducing maleic anhydride grafting polyolefin and / or quaternary ammonium salt modified montmorillonite, and polar component such as polyurethane elastomer, jointly act to make "four high" material of high melt index, high impact, high modulus and high paint adhesion, can be used for the preparation of automobile thin-wall bumper part, removes the pretreatment of automobile bumper paint spraying, saves energy, reduces production cost, safely and efficiently realizes automobile light weight.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high polymer material modification, and particularly relates to a high-paint-adhesion automobile thin-wall bumper material, a preparation method and application thereof. BACKGROUND

[0002] Polypropylene has low density, excellent mechanical properties, good processing performance, wide source and low price, etc., and the modified polypropylene through various modification processing means can meet different requirements of various automobile parts, so that various toughened and reinforced polypropylene materials are widely used in the automobile industry.

[0003] For the needs of aesthetics and prolonging the service life of the parts, automobile bumpers are generally subjected to paint spraying treatment, but the conventional polypropylene is a non-polar semi-crystalline polymer, has low surface energy and poor paint adhesion, and generally needs to be subjected to flame treatment, corona treatment, chemical oxidation treatment and the like to improve the surface tension of the polypropylene material, wherein the flame treatment is the most commonly used method, but since the polypropylene is a semi-crystalline polymer, the flame treatment method is easy to cause the size change of the bumper part, which can cause the part size to be unqualified, the part to be warped, local scorching to be scrapped and the like. Meanwhile, the flame treatment can also cause the consumption of energy and the increase of labor cost, and reduce the production efficiency.

[0004] With the increasing popularity of the development concept of environmental protection and green, the lightweight of automobile materials has also become an inevitable trend of automobile development, and the lightweight can not only reduce the weight of the vehicle body, save energy, reduce oil consumption and pollution, but also reduce the cost and improve the competitiveness of enterprises. Among them, the automobile bumper is the heaviest plastic part in the automobile (4-5 Kg), and the thin-wall design of the automobile bumper is one of the important ways to realize the lightweight of the automobile. The current mainstream bumper design wall thickness is 2.5-3.5 mm, and if the wall thickness is reduced to 1.8-2.5 mm, the weight of the bumper part can be reduced by 1 / 3, which not only reduces the amount of plastic for injection molding and shortens the molding cycle, but also realizes the lightweight of the automobile material, achieving the environmental protection effect from two aspects. However, the thinner wall thickness of the bumper puts forward more stringent requirements on the performance of the raw material, such as better molding property, higher bending modulus, higher impact strength and better dimensional stability.

[0005] CN101717548B introduces TPU, epoxy resin, ethylene acrylic acid (EEA), ethylene vinyl acetate (EVA), polyether amine and polybutylene polyol and other polar additives into polypropylene to improve the polarity of polypropylene, but due to the poor compatibility of PP, a non-polar material, with polar additives, the polarity of the composite is limitedly improved, and the impact resistance and bending modulus are also low, which cannot be practically applied to the preparation of thin-wall bumpers. CN109679219A catalytically prepares a polar additive from long-chain acrylate, acrylamide and long-chain olefin, but the polar additive has low grafting rate in water solvent and complex post-treatment, which is difficult to be industrialized.

[0006] CN110951163B describes that the amino silane oligomer powder is composed of more than 60% amino silane dispersed in fumed silica, and a composite with good comprehensive performance is prepared, but the amino silane oligomer powder is alkaline and easy to react with acidic water-soluble paint to cause discoloration, and the amino silane oligomer powder is extremely easy to self-ignite in air, which will bring great production safety hazards. CN114835974A uses maleic anhydride grafted polypropylene on the market to enhance the surface bonding force of polypropylene and paint, but the grafting rate of maleic anhydride grafted polypropylene on the market is low, the polarity is limitedly improved, and the modulus of the material is lower than 2000MPa and the impact is lower than 30KJ / m 2 , which cannot meet the harsh performance requirements of thin-wall bumpers.

[0007] In summary, the automobile thin-wall bumper puts forward higher requirements on the raw materials, and the raw materials need to have good impact resistance, dimensional stability and processing fluidity under the premise of ensuring high rigidity, so as to obtain a thin-wall bumper with good shape supporting effect under the premise of reducing the molding cycle, and the flame treatment before the bumper is painted will also affect the dimensional stability and reduce the pass rate of the thin-wall bumper. In order to avoid this situation, the modified polypropylene composite material also requires high paint adhesion. In order to meet the design requirements of the automobile thin-wall bumper, the polypropylene composite material formula needs more sophisticated design and more stringent material selection. SUMMARY

[0008] In view of the problems existing in the prior art, one object of the present application is to provide a high paint adhesion automobile thin-wall bumper material, which can be made into a "four-high" material with high melt index, high impact resistance, high modulus and high paint adhesion, and can be used for the preparation of automobile thin-wall bumper parts, thereby eliminating the pretreatment of automobile bumper painting, saving energy, reducing production cost and realizing automobile lightweighting safely and efficiently.

[0009] Another object of the present application is to provide a preparation method of the high paint adhesion automobile thin-wall bumper material.

[0010] Another object of the present application is to provide the use of the high paint adhesion automobile thin-wall bumper material.

[0011] To achieve the above objects, the present application adopts the following technical solutions.

[0012] The high paint adhesion automobile thin-wall bumper material comprises polypropylene, polyethylene, thermoplastic polyurethane elastomer, maleic anhydride grafted polyolefin and / or quaternary ammonium salt modified montmorillonite, filler, antioxidant and lubricant.

[0013] In a preferred embodiment, the components include 50-100 parts by weight of polypropylene, 5-10 parts by weight of polyethylene, 0-5 parts by weight of maleic anhydride grafted polypropylene, 5-10 parts by weight of thermoplastic polyurethane elastomer, 0-5 parts by weight of quaternary ammonium salt modified montmorillonite, 10-25 parts by weight of filler, 0.2-0.8 parts by weight of antioxidant and 0.1-0.4 parts by weight of lubricant; wherein the parts by weight of maleic anhydride grafted polyolefin and quaternary ammonium salt modified montmorillonite are not zero at the same time, and the total is not less than 1 part by weight.

[0014] In a more preferred embodiment, the components include 50-80 parts by weight of polypropylene, 5-7 parts by weight of polyethylene, 1-3 parts by weight of maleic anhydride grafted polypropylene, 7-9 parts by weight of thermoplastic polyurethane elastomer, 1-5 parts by weight of quaternary ammonium salt modified montmorillonite, 19-23 parts by weight of filler, 0.2-0.8 parts by weight of antioxidant and 0.1-0.4 parts by weight of lubricant.

[0015] In a specific embodiment, the polypropylene is selected from one or more of homopolymer polypropylene, copolymer polypropylene;

[0016] Preferably, the polypropylene has a melt flow rate of 3-200 g / 10 min (230℃, 2.16 kg); more preferably, the polypropylene is a commercially available polypropylene with a number average molecular weight of 200-300 thousand.

[0017] In a specific embodiment, the polyethylene is selected from one or more of high density polyethylene, low density polyethylene, linear low density polyethylene;

[0018] Preferably, the polyethylene is a commercially available polyethylene with a number average molecular weight of 1-10 million.

[0019] In a specific embodiment, the maleic anhydride grafted polyolefin is prepared by reactive extrusion of a polyolefin, maleic anhydride and an unsaturated polymer; preferably, the unsaturated polymer is selected from at least one of isoprene polymer, ethylene propylene diene rubber, nitrile rubber, cis-polybutadiene rubber, styrene butadiene rubber, styrene-butadiene-styrene block copolymer, styrene-isoprene-styrene block copolymer, and the grafting ratio of the maleic anhydride grafted polyolefin is 3-4%; more preferably, the grafting body of the maleic anhydride grafted polyolefin is selected from at least one of polypropylene-maleic anhydride graft copolymer, ethylene-butene-maleic anhydride modified elastomer, ethylene-octene-maleic anhydride modified elastomer.

[0020] In a specific embodiment, the thermoplastic polyurethane elastomer is a hydroxyl-terminated polyurethane elastomer with a molecular weight of 30-100 thousand; preferably, the thermoplastic polyurethane elastomer is formed by chain extension of a hydroxyl-terminated polyurethane prepolymer with a molecular weight of 1-3 thousand.

[0021] In a specific embodiment, the quaternary ammonium salt modified montmorillonite is selected from at least one of quaternary ammonium salt melt intercalation modified montmorillonite with cation [(CH3(CH2) 15 COO(CH2)2) x N(CH3)(CH2CH2OH) 3-x ] + Br 15 COO(CH2)2)2N(CH3)(CH2CH2OH)1] + Br - , [(CH3(CH2) 15 COO(CH2)2)1N(CH3)(CH2CH2OH)2] + Br - .

[0022] In a specific embodiment, the filler is selected from at least one of talc, calcium carbonate, wollastonite, whisker, mica, or a combination of two or more thereof.

[0023] In a specific embodiment, the antioxidant includes a primary antioxidant and a secondary antioxidant, the primary antioxidant is selected from one or more of hindered phenol, hindered amine antioxidant; the secondary antioxidant is selected from one or more of sulfur ester, phosphite antioxidant;

[0024] Preferably, the lubricant is selected from one or more of stearic acid, zinc stearate, magnesium stearate, calcium stearate.

[0025] In another aspect, a method for preparing the high paint adhesion automobile thin-wall bumper material as described above comprises the following steps: putting the components into a closed single screw extruder according to the ratio, mixing the components evenly at a processing temperature of 180-230 DEG C, and extruding and granulating to obtain the high paint adhesion automobile thin-wall bumper material.

[0026] In another aspect, the application of the high paint adhesion automobile thin-wall bumper material as described above or prepared by the method as described above in the field of automobile industry.

[0027] Compared with the prior art, the application has the following beneficial effects:

[0028] (1) The application introduces polyurethane elastomer and optional polar components such as maleic anhydride grafted polyolefin and / or quaternary ammonium salt modified montmorillonite into the polypropylene resin matrix to improve the polarity of the material, and the esterification reaction product of maleic anhydride in the extrusion reaction product of maleic anhydride grafted polyolefin and / or quaternary ammonium salt modified montmorillonite or unreacted maleic anhydride grafted polyolefin and the short hydroxyl group of the in-situ synthesized thermoplastic polyurethane elastomer is a compatibilizer for PP (polypropylene) and TPU (polyurethane elastomer), which further improves the surface tension and impact resistance of the composite material, eliminates the process of flame treatment before paint spraying, avoids the problems of size change, warping, local scorching and scrap of the bumper parts, reduces the consumption of energy, lowers the labor cost and other costs, and improves the production efficiency.

[0029] (2) The application obtains the modified polypropylene composite material with high melt index, high modulus, high impact resistance and high paint adhesion through a safe and efficient processing method, which is used for the production of thin-wall bumpers to realize the lightweight of automobiles, reduces the amount of automobile materials, saves energy, reduces fuel consumption and pollution, reduces the amount of injection molding glue and shortens the molding cycle, reduces the production cost, and improves the competitiveness of enterprises. DETAILED DESCRIPTION

[0030] The application will be further described below in combination with examples, but the protection scope of the application is not limited to the examples, and any known changes within the scope of the claims of the application should also be included.

[0031] A high paint adhesion automobile thin-wall bumper material comprises the following components:

[0032] Polypropylene, polyethylene, thermoplastic polyurethane elastomer, maleic anhydride grafted polyolefin and / or quaternary ammonium salt modified montmorillonite, filler, antioxidant, lubricant; wherein the maleic anhydride grafted polyolefin and the quaternary ammonium salt modified montmorillonite can only include one of them, and preferably both.

[0033] In one embodiment, the composition comprises the following components by weight: 50-100 parts by weight of polypropylene, 5-10 parts by weight of polyethylene, 0-5 parts by weight of maleic anhydride grafted polypropylene, 5-10 parts by weight of thermoplastic polyurethane elastomer, 0-5 parts by weight of quaternary ammonium salt modified montmorillonite, 10-25 parts by weight of filler, 0.2-0.8 parts by weight of antioxidant, 0.1-0.4 parts by weight of lubricant; wherein the parts by weight of maleic anhydride grafted polyolefin and quaternary ammonium salt modified montmorillonite are not simultaneously 0, and the total parts by weight of maleic anhydride grafted polyolefin and quaternary ammonium salt modified montmorillonite is not less than 1 part by weight.

[0034] In one embodiment, the composition comprises the following components by weight: 50-80 parts by weight of polypropylene, 5-7 parts by weight of polyethylene, 1-3 parts by weight of maleic anhydride grafted polypropylene, 7-9 parts by weight of thermoplastic polyurethane elastomer, 1-5 parts by weight of quaternary ammonium salt modified montmorillonite, 19-23 parts by weight of filler, 0.2-0.8 parts by weight of antioxidant, 0.1-0.4 parts by weight of lubricant.

[0035] The polypropylene is selected from one or more of homopolymer polypropylene and copolymer polypropylene. It is known in the art that homopolymer polypropylene is a homopolymer polymerized from propylene monomer, and copolymer polypropylene is a copolymer polymerized from propylene monomer and a relatively small amount of other monomers (for example, ethylene monomer). The melt flow rate of the polypropylene is 3-200 g / 10 min (230°C, 2.16 kg), for example, but not limited to, 3 g / 10 min, 5 g / 10 min, 10 g / 10 min, 20 g / 10 min, 30 g / 10 min, 50 g / 10 min, 80 g / 10 min, 100 g / 10 min, 120 g / 10 min, 150 g / 10 min, 180 g / 10 min, 200 g / 10 min. Preferably, for copolymer polypropylene, the melt flow rate is 10-120 g / 10 min (230°C, 2.16 kg), for example, 29 g / 10 min, 50 g / 10 min, 80 g / 10 min, 100 g / 10 min, etc. The polypropylene of the present application can be a commercially available polypropylene, and the number average molecular weight is, for example, 200-300 million, for example, 200 million, 250 million, 300 million, etc. The amount of polypropylene added is 50-100 parts by weight, for example, but not limited to, 50 parts by weight, 55 parts by weight, 60 parts by weight, 65 parts by weight, 70 parts by weight, 75 parts by weight, 80 parts by weight, 85 parts by weight, 90 parts by weight, 95 parts by weight, 100 parts by weight, etc., preferably 50-80 parts by weight.

[0036] The polyethylene is selected from one or more of high density polyethylene, low density polyethylene, linear low density polyethylene, which is a long chain linear structure and a branched structure with long and short branches, and the molecular weight range is between 1-100,000, for example, commercially available polyethylene with a molecular weight of 10,000, 20,000, 30,000, 40,000, 50,000, 60,000, 70,000, 80,000, 90,000, 100,000, etc. Among them, the addition amount of polyethylene is 5-10 parts by weight, for example, including but not limited to 5 parts by weight, 6 parts by weight, 7 parts by weight, 8 parts by weight, 9 parts by weight, 10 parts by weight, etc., preferably 5-7 parts by weight.

[0037] The maleic anhydride grafted polyolefin is obtained by reaction extrusion of polyolefin, maleic anhydride and unsaturated polymer, which can improve the compatibility of polypropylene matrix and thermoplastic polyurethane elastomer. The grafting main body of the maleic anhydride grafted polyolefin is mainly polypropylene-maleic anhydride graft copolymer, ethylene-butene-maleic anhydride modified elastomer, ethylene-octene-maleic anhydride modified elastomer, the introduction of unsaturated polymer can improve the grafting rate of maleic anhydride, and the introduced unsaturated polymer includes at least one of isoprene polymer, ethylene-propylene-diene rubber, nitrile rubber, cis-butadiene rubber, butadiene-styrene rubber, styrene-butadiene-styrene block copolymer and styrene-isoprene-styrene block copolymer, the grafting rate of the maleic anhydride grafted polyolefin added with unsaturated polymer in the present application can reach 3-4%, which is recorded as CMG001, while the grafting rate of maleic anhydride grafted polyolefin without adding unsaturated polymer is only 1-2%, which is recorded as CMG000. Among them, the addition amount of maleic anhydride grafted polypropylene is 0-5 parts by weight, for example, including but not limited to 0 parts by weight, 1 parts by weight, 2 parts by weight, 3 parts by weight, 4 parts by weight, 5 parts by weight, etc., preferably 1-3 parts by weight. As mentioned before, when the addition amount of maleic anhydride grafted polyolefin is 0, the addition amount of quaternary ammonium salt modified montmorillonite is at least 1 part by weight.

[0038] The thermoplastic polyurethane elastomer is a hydroxyl-terminated polyurethane elastomer with a molecular weight of 3-100,000 (for example, 30,000, 40,000, 50,000, 60,000, 70,000, 80,000, 90,000, 100,000, etc.), which is a thermoplastic elastomer formed by chain extension of isocyanate (NCO) terminated polyurethane prepolymer; the molecular weight of the polyurethane prepolymer is 1-30,000, for example, 10,000, 20,000, 30,000, etc. Among them, the addition amount of the thermoplastic polyurethane elastomer is 5-10 parts by weight, for example, including but not limited to 5 parts by weight, 6 parts by weight, 7 parts by weight, 8 parts by weight, 9 parts by weight, 10 parts by weight, etc., preferably 7-9 parts by weight.

[0039] The quaternary ammonium salt modified montmorillonite is in the form of cation [(CH3(CH2) 15 COO(CH2)2) x N(CH3)(CH2CH2OH) 3-x ]+ quaternary ammonium salt melt intercalation modified montmorillonite, x is a natural number less than 3, for example 0, 1, 2, 3; in particular, the quaternary ammonium salt is, for example, ([(CH3(CH2) 15 COO(CH2)2)2N(CH3)(CH2CH2OH)1] + Br - ,[(CH3(CH2) 15 COO(CH2)2)1N(CH3)(CH2CH2OH)2] + Br - ) of any one of them, such quaternary ammonium salt melt intercalation modified montmorillonite has both lipophilic long carbon chain and hydrophilic montmorillonite and cation and anion, and the prepared quaternary ammonium salt modified montmorillonite has good dispersibility in polar and non-polar solvents. Among them, the intercalation modification method of quaternary ammonium salt modified montmorillonite can refer to the prior art, for example, quaternary ammonium salt and montmorillonite are processed by single screw extruder at 260℃ and 80r / min speed. This intercalation modification method is a conventional technical means in the art. Among them, the addition amount of the quaternary ammonium salt modified montmorillonite is 0-5 parts by weight, for example, including but not limited to 1 part by weight, 2 parts by weight, 3 parts by weight, 4 parts by weight, 5 parts by weight, preferably 1-5 parts by weight. As described above, when the addition amount of quaternary ammonium salt modified montmorillonite is 0, the addition amount of maleic anhydride grafted polyolefin is at least 1 part by weight.

[0040] The filler is selected from any one or a combination of two or more of talc, calcium carbonate, wollastonite, whisker, mica, for example, commonly used are talc and / or calcium carbonate, and the particle size of the filler is preferably 1250-5000 mesh, for example, 1250 mesh, 1500 mesh, 1750 mesh, 2000 mesh, 2500 mesh, 3000 mesh, 3500 mesh, 4000 mesh, 4500 mesh, 5000 mesh, etc. Among them, the addition amount of the filler is 10-25 parts by weight, for example, including but not limited to 10 parts by weight, 11 parts by weight, 12 parts by weight, 13 parts by weight, 14 parts by weight, 15 parts by weight, 16 parts by weight, 17 parts by weight, 18 parts by weight, 19 parts by weight, 20 parts by weight, 21 parts by weight, 22 parts by weight, 23 parts by weight, 24 parts by weight, 25 parts by weight, etc., preferably 19-23 parts by weight.

[0041] The antioxidant includes a primary antioxidant and a secondary antioxidant, the primary antioxidant includes but is not limited to one or more of hindered phenol and hindered amine antioxidant, such as RIANOX 1010; the secondary antioxidant includes but is not limited to one or more of sulfur ester and phosphite antioxidant, such as RIANOX 168. Preferably, the primary antioxidant is tetra (beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionic acid) pentaerythritol (antioxidant 1010); preferably, the secondary antioxidant is tris (2, 4-di-tert-butylphenyl) phosphite (antioxidant 168). Among them, the mass ratio of the primary antioxidant and the secondary antioxidant can be 1:1 or slightly greater than 1:1, preferably, the primary antioxidant is 0.1-0.4 parts by weight, and the secondary antioxidant is 0.1-0.3 parts by weight. Among them, the addition amount of the antioxidant is 0.2-0.8 parts by weight, for example, including but not limited to 0.2 parts by weight, 0.3 parts by weight, 0.4 parts by weight, 0.5 parts by weight, 0.6 parts by weight, 0.7 parts by weight, 0.8 parts by weight.

[0042] The lubricant is one or more of stearic acid, zinc stearate, magnesium stearate, calcium stearate, wherein the addition amount of the lubricant is 0.1-0.4 parts by weight, for example, including but not limited to 0.1 parts by weight, 0.2 parts by weight, 0.3 parts by weight, 0.4 parts by weight.

[0043] The application also provides a preparation method of the high paint adhesion automobile thin-wall bumper material.

[0044] The high paint adhesion automobile thin-wall bumper material can be prepared in the equipment known in the art, preferably a closed single screw extruder. The preparation method comprises the following steps:

[0045] According to the above proportion, the polypropylene, polyethylene, maleic anhydride grafted polyolefin, thermoplastic polyurethane elastomer, quaternary ammonium salt modified montmorillonite, filler, antioxidant, lubricant are put into a closed single screw extruder, mixed uniformly, and then extruded and granulated after sufficient reaction, to obtain the high paint adhesion automobile thin-wall bumper material.

[0046] The processing temperature of the preparation method is 180-230℃, for example, 180℃, 190℃, 200℃, 210℃, 220℃, 230℃, etc., and the processing time is 5-10min, for example, 5min, 6min, 7min, 8min, 9min, 10min, etc.; preferably, the processing temperature is 180-200℃, and the processing time is 7min.

[0047] The high paint adhesion automobile thin-wall bumper material can be obtained by blending and extruding granulation of the components in a mixing type single screw extruder according to the ratio during preparation of the application. The application introduces maleic anhydride grafted polyolefin and / or quaternary ammonium salt modified montmorillonite and polar components such as polyurethane elastomer to improve the paintable performance of the material, eliminate the pretreatment of automobile bumper painting, save energy, and reduce production cost. The maleic anhydride grafted polyolefin and quaternary ammonium salt modified montmorillonite extrusion reaction product is used as a compatibilizer of polypropylene and polyurethane elastomer to improve the impact resistance and surface tension of the PP (polypropylene) / TPU (polyurethane elastomer) composite material. In the preparation of the maleic anhydride grafted polyolefin, an unsaturated polymer is added to improve the grafting rate. The esterification reaction between the unreacted maleic anhydride in the maleic anhydride grafted polyolefin and the short hydroxyl groups of the in-situ synthesized thermoplastic polyurethane elastomer produces a chemical bond, which can also increase the compatibility of polypropylene and polyurethane elastomer, further improve the impact resistance and surface tension of the material, and jointly produce a “four-high” material with high melt index, high impact resistance, high modulus and high paint adhesion. The material can be used for the preparation of automobile thin-wall bumper parts, eliminates the pretreatment of automobile bumper painting, saves energy, reduces production cost, and realizes safe and efficient automobile lightweighting.

[0048] The application will be further explained and illustrated by more specific examples below, but without any limitation.

[0049] Raw materials used in the examples and comparative examples:

[0050] K9829H: Copolymerized PP, melt index 29 g / 10 min (230 DEG C, 2.16 kg), produced by Yanshan Petrochemical;

[0051] EP648V: Copolymerized PP, melt index 100 g / 10 min (230 DEG C, 2.16 kg), produced by Wanhua Chemical;

[0052] HD-6081: High-density polyethylene, melt index 10 g / 10 min (230 DEG C, 2.16 kg), produced by Ningxia Baofeng;

[0053] DFDA 7042: Linear low-density polyethylene, melt index 2 g / 10 min (230 DEG C, 2.16 kg), produced by Zhenhai Refining and Chemical;

[0054] TPU WHT-1490: Polyurethane elastomer, average molecular weight 40000, Wanhua Chemical;

[0055] E05L: 5000-mesh talcum powder, produced by Liaoning Aihaimi Mining Co., Ltd.;

[0056] RIANOX 1010 / 168: antioxidant, Tianjin Li'an Longxin Material Co., Ltd.

[0057] ZnSt: lubricant, Foskin Chemical Co., Ltd.

[0058] MMT BP-188L: montmorillonite, Zhejiang Huateli Industry Group

[0059] CMG000: maleic anhydride grafted polyolefin was prepared by reaction extrusion with single screw extruder at 200℃, 160r / min, mass ratio of polypropylene / dicumyl peroxide / maleic anhydride / styrene = 100 / 0.2 / 2 / 0.8, grafting rate 1.2%;

[0060] CMG001: maleic anhydride grafted polyolefin was prepared by reaction extrusion with single screw extruder at 200℃, 160r / min, mass ratio of polypropylene / dicumyl peroxide / maleic anhydride / isoprene polymer / styrene = 100 / 0.2 / 2 / 1 / 0.8, grafting rate 3.2%;

[0061] CMG002: maleic anhydride grafted polyolefin was prepared by reaction extrusion with single screw extruder at 200℃, 160r / min, mass ratio of polypropylene / dicumyl peroxide / maleic anhydride / styrene-butadiene-styrene block copolymer / styrene = 100 / 0.2 / 2 / 1 / 0.8, grafting rate 3.4%;

[0062] CMG003: maleic anhydride grafted polyolefin was prepared by reaction extrusion with single screw extruder at 200℃, 160r / min, mass ratio of polypropylene / dicumyl peroxide / maleic anhydride / nitrile rubber / styrene = 100 / 0.2 / 2 / 1 / 0.8, grafting rate 3.1%;

[0063] DK000A: [(CH3(CH2) 15 COO(CH2)2)2N(CH3)(CH2CH2OH)1] + Br - Mixed with MMT at a mass ratio of 5:95 to prepare quaternary ammonium salt modified montmorillonite;

[0064] DK001A: [(CH3(CH2) 15 COO(CH2)2)1N(CH3)(CH2CH2OH)2] + Br - Mixed with MMT at a mass ratio of 5:95 to prepare quaternary ammonium salt modified montmorillonite.

[0065] Test method and equipment:

[0066] (1) Charpy notched impact strength test equipment and method: impact testing machine ZWICK HIT25P, according to ISO180:2019 test;

[0067] (2) Bending test equipment and method: universal testing machine ZWICK Z010, according to ISO 178:2019 method A test;

[0068] (3) Melt mass flow rate test equipment and method: melt indexer Zwick Aflow, according to standard ISO1133-1:2022 test;

[0069] (4) Surface tension test equipment and method: YINNO SLZF-A, according to standard ISO 1409:2006 test;

[0070] (5) Crosshatch test equipment and method: Deli crosshatch knife, according to standard GB9286:1998 test;

[0071] (6) Test method for grafting rate in polyolefin grafted maleic anhydride: phenolphthalein reagent titration method.

[0072] Examples and comparative examples

[0073] The modified polypropylene composite material of the comparative examples was prepared according to the proportions shown in Table 1 (the amount of each component in the table represents parts by weight), and the modified polypropylene composite material of the examples was prepared according to the proportions shown in Table 2. The preparation process included:

[0074] The polypropylene, polyethylene, maleic anhydride grafted polyolefin, thermoplastic polyurethane elastomer, quaternary ammonium salt modified montmorillonite, filler, antioxidant, lubricant were weighed and put into a closed single screw extruder, mixed uniformly and reacted fully at the specified temperature and time, then extruded and granulated to obtain the modified polypropylene composite material.

[0075] Table 1 Proportions and processing conditions of comparative examples 1-4

[0076] Raw material name Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 K9829H 47 39 38 36 EP648V 25.4 25.4 25.4 25.4 HD-6081 6 6 6 6 CMG000 1 3 TPU WHT-1490 8 8 8 E05L 21 21 21 21 RIANOX 1010 0.2 0.2 0.2 0.2 RIANOX 168 0.2 0.2 0.2 0.2 ZnSt 0.2 0.2 0.2 0.2 Processing temperature / °C 190 190 190 190 Processing time / min 7 7 7 7

[0077] Table 2 Proportions and processing conditions of examples 1-7

[0078]

[0079]

[0080] The polypropylene composite materials obtained in comparative examples 1-4 and examples 1-7 were tested for performance, and the specific results are shown in Tables 3 and 4.

[0081] Table 3 Melt index, tensile modulus, Izod notched impact, surface tension and crosshatch test results for each comparative example

[0082] Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Melt index g / 10 min (230°C, 2.16 kg) 44 32 30 29 Flexural modulus MPa 2398 1780 1829 1878 Izod notched Charpy KJ / m 2 ]]> 24.3 34.6 35.7 36.1 Surface tension (mN / m) 27 33 35 37 Haze test Fall-off Fall-off Fall-off Fall-off Fall-off

[0083] Table 4 Melt index, tensile modulus, Izod notched impact, surface tension and crosshatch test results for each example

[0084]

[0085] From Table 3, it can be seen that the introduction of polyurethane elastomer improves the impact strength and surface tension of the material, but reduces the bending modulus and melt index of the material, but it is still difficult to meet the requirements of paint adhesion. With the addition of maleic anhydride grafted polyolefin synthesized by unsaturated polymerization process, the surface tension is improved, but when the addition amount is 3%, the paint will still fall off.

[0086] Combining the data of Examples 1-2 in Table 4, it is found that the maleic anhydride grafted polyolefin synthesized by unsaturated polymerization process is better than the maleic anhydride grafted polyolefin not synthesized by unsaturated polymerization process in terms of surface tension and other mechanical effects. Examples 4-6 show that quaternary ammonium salt modified montmorillonite can better improve the surface tension of the composite material, and the effect of improving the bending modulus is better than that of maleic anhydride grafted polyolefin. From the data of Example 7, it can be concluded that the effect of adding maleic anhydride grafted polyolefin and quaternary ammonium salt modified montmorillonite at the same time is much better than that of adding them alone at the same ratio, especially in terms of improving surface tension and impact resistance, which directly proves the synergistic effect of quaternary ammonium salt modified montmorillonite and maleic anhydride grafted polyolefin.

[0087] The above description of the examples is to facilitate the understanding and application of the present application by those of ordinary skill in the art. Those skilled in the art can easily make various modifications to these examples, and apply the general principles described herein to other examples without having to go through creative labor. Therefore, the present application is not limited to the examples herein, and improvements and modifications made by those skilled in the art without departing from the scope of the present application should be within the scope of protection of the present application.

Claims

1. A high paint adhesion automotive thin wall bumper material characterized by, polypropylene, polyethylene, thermoplastic polyurethane elastomer, maleic anhydride grafted polyolefin and / or quaternary ammonium salt modified montmorillonite, filler, antioxidant, lubricant; the maleic anhydride grafted polyolefin is prepared by reactive extrusion of polyolefin, maleic anhydride and unsaturated polymer; said quaternary ammonium salt modified montmorillonite is selected from the group consisting of quaternary ammonium salt melt intercalation modified montmorillonite with cation [(CH3(CH2) 15 COO(CH2)2) x N(CH3)(CH2CH2OH) 3-x ] + x is a natural number less than 3; the filler is selected from any one or combination of two or more of talc, calcium carbonate, wollastonite, whisker, mica.

2. The high paint adhesion automotive thin wall bumper material of claim 1, wherein, comprise the following components by weight: 50-100 parts by weight of polypropylene, 5-10 parts by weight of polyethylene, 0-5 parts by weight of maleic anhydride grafted polyolefin, 5-10 parts by weight of thermoplastic polyurethane elastomer, 0-5 parts by weight of quaternary ammonium salt modified montmorillonite, 10-25 parts by weight of filler, 0.2-0.8 parts by weight of antioxidant, 0.1-0.4 parts by weight of lubricant; wherein the parts by weight of maleic anhydride grafted polyolefin and quaternary ammonium salt modified montmorillonite are not simultaneously 0, and the total is not less than 1 part by weight.

3. The high paint adhesion automotive thin wall bumper material of claim 2, wherein, comprise the following components by weight: 50-80 parts by weight of polypropylene, 5-7 parts by weight of polyethylene, 1-3 parts by weight of maleic anhydride grafted polyolefin, 7-9 parts by weight of thermoplastic polyurethane elastomer, 1-5 parts by weight of quaternary ammonium salt modified montmorillonite, 19-23 parts by weight of filler, 0.2-0.8 parts by weight of antioxidant, 0.1-0.4 parts by weight of lubricant.

4. The high paint adhesion automotive thin wall bumper material according to any one of claims 1-3, characterized in that, the polypropylene is selected from one or more of homopolymer polypropylene, copolymer polypropylene.

5. The high paint adhesion automotive thin wall bumper material of claim 4, wherein, the melt flow rate of the polypropylene at 230℃, 2.16kg is 3-200g / 10min.

6. The high paint adhesion automotive thin wall bumper material of claim 5, wherein, the polypropylene is commercially available polypropylene with a number average molecular weight of 200-300 thousand.

7. The high paint adhesion automotive thin wall bumper material according to any one of claims 1-3, characterized in that, the polyethylene is selected from one or more of high density polyethylene, low density polyethylene, linear low density polyethylene.

8. The high paint adhesion automotive thin wall bumper material of claim 7, wherein, the polyethylene is commercially available polyethylene with a number average molecular weight of 1-100 thousand.

9. The high paint adhesion automotive thin wall bumper material according to any one of claims 1-3, characterized in that, the unsaturated polymer is selected from at least one of isoprene polymer, ethylene propylene terpolymer, nitrile rubber, cis-butadiene rubber, styrene-butadiene rubber, styrene-butadiene-styrene block copolymer, styrene-isoprene-styrene block copolymer, and the grafting rate of the maleic anhydride grafted polyolefin is 3-4%.

10. The high paint adhesion automotive thin wall bumper material of claim 9, wherein, the grafting body of the maleic anhydride grafted polyolefin is selected from at least one of polypropylene-maleic anhydride graft copolymer, ethylene-butene-maleic anhydride modified elastomer, ethylene-octene-maleic anhydride modified elastomer.

11. The high paint adhesion automotive thin wall bumper material according to any one of claims 1-3, characterized in that, the thermoplastic polyurethane elastomer is a hydroxyl-terminated polyurethane elastomer with a molecular weight of 3-10 thousand.

12. The high paint adhesion automotive thin wall bumper material of claim 7, wherein, the thermoplastic polyurethane elastomer is formed after chain extension of isocyanate (NCO) terminated polyurethane prepolymer, and the molecular weight of the polyurethane prepolymer is 1-3 thousand.

13. The high paint adhesion automotive thin wall bumper material according to any one of claims 1-3, characterized in that, The quaternary ammonium salt is selected from [(CH3(CH2)] 15 COO(CH2)2)2N(CH3)(CH2CH2OH)1] + Br - 、[(CH3(CH2) 15 COO(CH2)2)1N(CH3)(CH2CH2OH)2] + Br - At least one of them.

14. The high paint adhesion automotive thin wall bumper material according to any one of claims 1-3, characterized in that, the antioxidant comprises primary antioxidant and secondary antioxidant, the primary antioxidant is selected from one or more of hindered phenol, hindered amine antioxidant; the secondary antioxidant is selected from one or more of sulfur ester, phosphite antioxidant.

15. The high paint adhesion automotive thin wall bumper material according to any one of claims 1-3, characterized in that, the lubricant is selected from one or more of stearic acid, zinc stearate, magnesium stearate, calcium stearate.

16. A process for the preparation of a high paint adhesion automotive thin wall bumper material according to any one of claims 1 to 15, characterized in that, The step of obtaining the high paint adhesion automobile thin-wall bumper material comprises the following steps: putting the components into a closed single screw extruder according to the proportion, uniformly mixing the components in the closed state at a processing temperature of 180-230 DEG C, and extruding and granulating to obtain the high paint adhesion automobile thin-wall bumper material.

17. Use of the high paint adhesion automobile thin-wall bumper material according to any one of claims 1-15 or prepared by the preparation method of claim 16 in the field of automobile industry.

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