A foamed polypropylene composition and its preparation method and application

Abstract

The invention discloses a foamed polypropylene composition and a preparation method and application thereof, belonging to the technical field of polymer engineering plastics; the foamed polypropylene composition provided by the invention comprises the following components in parts by mass: 52-98 parts of PP resin, 0.3-3.2 parts of high specific surface area filler, 0.3-2.2 parts of polyol, and 0.3-2.2 parts of melt elasticity regulator. The foamed polypropylene composition provided by the invention can improve the foamability of the composition by selecting a PP resin with a certain melt flow rate, compounding a high specific surface area filler, a polyol and a melt elasticity regulator, while being able to reduce the size of the composition pores, and having high fluidity of the product, which is conducive to rapid molding of injection molding foaming; and the preparation method provided by the invention is simple, which is conducive to actual production.

Description

Technical Field

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

[0002] As a cost-effective general-purpose plastic, polypropylene has excellent mechanical properties of high strength and high toughness, as well as chemical resistance and high heat resistance after modification, and is widely used in home appliances and automotive products. As the global call for environmental protection, energy saving and consumption reduction becomes stronger and stronger, automobile lightweighting has become a major trend in the automotive industry. The micro-foamed polypropylene material obtained by combining polypropylene with micro-foaming technology has the advantages of low density, good thermal stability, and chemical corrosion resistance. It is widely used in automotive parts such as automobile door panels and dashboards, and has become one of the lightweight materials favored by vehicle lightweighting and new energy.

[0003] Polypropylene is a semi-crystalline material with low melt strength, which is prone to defects such as bubbles and bubbles. At the same time, for automotive interior door panels, due to the large size and complex shape of the integrated parts, combined with thin-wall technology, the polypropylene materials currently used in door panels have higher requirements for material fluidity, and the melt strength of polypropylene usually decreases significantly with the improvement of material fluidity, resulting in poor foaming effect of the material. At the same time, chemical foaming is used by mixing the foaming agent into the injection molding process, and melt mixing and dispersion with the polypropylene material under the screw and heating of the injection molding machine. The gas generated by its decomposition is easy to accumulate in the polypropylene melt, resulting in the problem of coarse bubbles in the final material.

[0004] Therefore, there is still a need in the art to develop a polypropylene composition having high fluidity and excellent foaming properties. Summary of the invention

[0005] The purpose of the present invention is to overcome the above-mentioned deficiencies of the prior art and provide a foamed polypropylene composition with excellent flowability and foaming performance, and a preparation method and application thereof.

[0006] To achieve the above object, in a first aspect of the present invention, the present invention provides a foamed polypropylene composition, the foamed polypropylene composition comprising the following components in parts by weight: 52-98 parts of PP resin, 0.3-3.2 parts of high specific surface area filler, 0.3-2.2 parts of polyhydroxy compound, and 0.3-2.2 parts of melt elasticity regulator;

[0007] The average specific surface area of ​​the high specific surface area filler is greater than 40 m 2 / g;

[0008] The hydroxyl content of the polyhydroxy compound is greater than 6%;

[0009] After the sorbitol compound is mixed with the PP resin, the viscoelastic temperature of the PP resin increases by more than 20°C;

[0010] The melt mass flow rate of the PP resin at 230° C. and 2.16 kg is 55-105 g / 10 min.

[0011] The foamed polypropylene composition provided by the present invention can improve the expandability of the composition by selecting a PP resin with a certain melt mass flow rate and compounding a high specific surface filler, a polyol and a melt elasticity regulator, while reducing the size of the foam cells of the composition, achieving high fluidity of the final product, and facilitating rapid molding of injection foaming. Specifically, by adding a suitable high specific surface area filler and a melt elasticity regulator as a heterogeneous nucleating agent of bubbles, the expandability and pore size of the material are improved; further, by using a polyol to improve the dispersion and distribution of the foaming agent in the melt, and by combining the adjustment of the viscoelasticity of the material by the melt elasticity regulator, the pore structure of the material is improved as a whole.

[0012] The test method for the average specific surface area of ​​high specific surface area fillers is to refer to GB-T19587-2004 for testing.

[0013] The hydroxyl content in the polyhydroxy compound is the mass percentage content of hydroxyl groups, which is calculated by chemical formula (the calculation formula is: hydroxyl content = 17*N / M*100%, wherein N is the number of hydroxyl groups in the molecular structure and M is the molecular mass).

[0014] The calculation method of the change in the viscoelastic temperature of the PP resin after the melt elasticity regulator is mixed with the PP resin is: viscoelastic temperature change = viscoelastic temperature of the mixture after the PP resin and the melt elasticity regulator are mixed - viscoelastic temperature of the PP resin, wherein the test method of the viscoelastic temperature is: the melt elasticity regulator is added to the PP resin BX3920 (manufacturer is sk, South Korea) at a ratio of 0.5wt%, and the modified plastic particles are obtained by screw extrusion granulation, and the particles are hot pressed into 1mm sample plates at 190℃, and 25mm discs are cut out for rotational rheology testing. The test parameters of the rotational rheometer are as follows: 25mm plate 1mm spacing, strain 2%, frequency 1rad / s, test temperature 200℃-120℃, cooling rate -5℃ / min.

[0015] The test method for the melt mass flow rate of PP resin at 230° C. and 2.16 kg is conducted in accordance with ISO1133-2005; the PP resin is at least one of homopolypropylene and copolymer polypropylene.

[0016] For example, the average specific surface area of ​​the high specific surface area may be >40 m 2 Any value of / g, such as 46-75m2 / g, 46-85m 2 / g, 75-85m 2 / g, etc., or can be >40m 2 / g any point value or any range value composed of two points, such as 41m 2 / g, 45m 2 / g, 48m 2 / g, 50m 2 / g, 52m 2 / g, 55m 2 / g, 58m 2 / g, 60m 2 / g, 62m 2 / g, 65m 2 / g, 68m 2 / g, 70m 2 / g, 72m 2 / g, 75m 2 / g, 78m 2 / g, 80m 2 / g, 82m 2 / g, 85m 2 / g, 88m 2 / g, 90m 2 / g, 92m 2 / g, 95m 2 / g, 98m 2 / g、100m 2 / g, etc., are not listed here due to space limitations. The average specific surface area given in the present invention may be >40m 2 / g range can achieve excellent comprehensive effects.

[0017] Preferably, the average specific surface area of ​​the high specific surface area is 46-75m 2 / g. The inventors found that when the average specific surface area of ​​the high specific surface area is further selected to be 46-75m 2 / g, the comprehensive effect of the obtained product is more excellent.

[0018] For example, the hydroxyl content of the polyol may be any value greater than 6%, such as 9.4-11.8%, 9.4-12.5%, 11.8-12.5%, etc., or any point value greater than 6% or a range value consisting of any two points, such as 6.1%, 6.3%, 6.5%, 6.8%, 7.0%, 7.2%, 7.5%, 7.8%, 8.0%, 8.2%, 8.5%, 8.8%, 9.0%, 9.2%, 9.5%, 9.8%, 10.0%, 10.2%, 10.5%, 10.8%, 11.0%, 11.2%, 11.5%, 11.8%, 12.0%, 12.2%, 12.5%, 12.8%, 13.0%, etc., are not listed here one by one due to space limitations. Excellent comprehensive effects can be achieved within the range of hydroxyl content > 6% in the polyhydroxy compound given in the present invention. The present invention studies and speculates that, due to the hydrophilicity of hydroxyl, when the foamed polypropylene composition is mixed with the foaming agent for injection molding to prepare the foamed part, the foaming agent added during the injection molding process will decompose to produce carbon dioxide and water. Under the pressure of the screw of the injection molding machine, the decomposed carbon dioxide is easily dissolved in water. Therefore, by adjusting the hydrophilic hydroxyl content, the dispersion and distribution of carbon dioxide in the melt can be adjusted, thereby affecting the foaming effect.

[0019] Preferably, the hydroxyl content of the polyol is 9.4-11.8%. The inventors have found that when the hydroxyl content of the polyol is further selected to be 9.4-11.8%, the comprehensive effect of the obtained product is more excellent.

[0020] Illustratively, after the melt elasticity regulator is mixed with the PP resin, the viscoelastic temperature of the PP resin may be increased by 31-36°C, 35-45°C, 25-45°C, 25-35°C, etc., or increased by any point value above 20°C or a range value composed of any two points, such as 20°C, 22°C, 25°C, 28°C, 30°C, 32°C, 35°C, 38°C, 40°C, 42°C, 45°C, 48°C, 50°C, etc. Due to space limitations, they are not listed here one by one. As long as the selected melt elasticity regulator increases the viscoelastic temperature of the PP resin by more than 20°C after mixing with the PP resin, excellent results can be achieved. The present invention studies and speculates that when the foamed polypropylene composition is mixed with a foaming agent and used in the preparation of foamed parts, the melt strength of the material is significantly improved at the viscoelastic temperature transition point of the melt, which is beneficial to limiting the growth of cells. When the foaming agent is fully dispersed, limiting the growth of cells is beneficial to reducing the cell size and inhibiting the merging of cells. Therefore, the extent to which the viscoelastic temperature of the PP resin is increased after the selected melt elasticity regulator is mixed with the PP resin will affect the foaming effect.

[0021] Preferably, after the melt elasticity regulator is mixed with the PP resin, the viscoelastic temperature of the PP resin increases by 31-36° C. Within this range of increase, the comprehensive effect of the obtained product is more excellent.

[0022] Illustratively, the melt mass flow rate of the PP resin at 230°C and 2.16 kg may be 60-100 g / 10min, 60-80 g / 10min, 60-90 g / 10min, etc., or may be any point value of 55-105 g / 10min or a range value composed of any two points, such as 55 g / 10min, 60 g / 10min, 65 g / 10min, 70 g / 10min, 75 g / 10min, 80 g / 10min, 85 g / 10min, 90 g / 10min, 95 g / 10min, 100 g / 10min, 105 g / 10min, etc. Due to space limitations, they are not listed here one by one; within the range of 55-105 g / 10min given in the present invention, excellent results can be achieved.

[0023] Preferably, the melt mass flow rate of the PP resin at 230° C. and 2.16 kg is 80-90 g / 10 min. Within the given melt mass flow rate range, the comprehensive effect of the obtained product is more excellent.

[0024] The mass percentage of the PP resin in the foamed polypropylene composition is not less than 65%.

[0025] As a preferred embodiment of the foamed polypropylene composition of the present invention, the melt elasticity regulator is a sorbitol compound.

[0026] The inventors have found that when the melt elasticity regulator selected is a sorbitol compound, the size of the pores can be better reduced and the maximum weight loss rate can be increased.

[0027] As a preferred embodiment of the foamed polypropylene composition of the present invention, the high specific surface filler is selected from at least one of titanium dioxide, fumed alumina, silicon dioxide, organic clay, and porous silica gel.

[0028] The D50 particle size of the high specific surface area filler is ≤50 nm. The D50 particle size of the high specific surface area filler is tested by a laser particle size analyzer, with reference to ISO 13320-1-1999.

[0029] As a preferred embodiment of the foamed polypropylene composition of the present invention, the polyhydroxy compound is selected from at least one of glyceryl monostearate, sorbitan monostearate, sorbitan monolaurate, oleic acid diethanolamide, and polyethylene glycol.

[0030] As a preferred embodiment of the foamed polypropylene composition of the present invention, the sorbitol compound is at least one selected from 1,3-2,4-di(p-methylbenzylidene)sorbitol and 1,3-2,4-di(3,4-dimethylbenzylidene)sorbitol.

[0031] The inventors have found that when high specific area fillers, polyhydroxy compounds and sorbitol compounds are further selected as the above substances, the comprehensive effect of the obtained product is more excellent.

[0032] As a preferred embodiment of the foamed polypropylene of the present invention, the foamed polypropylene composition further comprises 0-20 parts of filler, 0-20 parts of toughening agent, and 0-1 part of auxiliary agent.

[0033] As a preferred embodiment of the foamed polypropylene composition of the present invention, the filler is selected from at least one of talc, calcium carbonate, barium sulfate and glass fiber;

[0034] And / or, the toughening agent is selected from at least one of POE, SEBS, and EPDM;

[0035] And / or, the auxiliary agent is selected from at least one of an antioxidant and a light stabilizer.

[0036] Exemplarily, the antioxidant may be at least one of a hindered phenol antioxidant and a phosphite antioxidant, and the light stabilizer may be a histamine-sensitive light stabilizer.

[0037] In a second aspect of the present invention, a method for preparing a foamed polypropylene composition is provided, the method comprising the following steps: weighing the dried raw materials, mixing them, and then melt-kneading them, followed by extrusion and granulation to obtain a foamed polypropylene composition.

[0038] As a preferred embodiment of the preparation method of the present invention, the temperature of the melt mixing is 200-210° C., and the screw speed is 350-450 r / min.

[0039] In a third aspect of the present invention, the present invention provides a foamed article, wherein the foamed article is prepared by using the foamed polypropylene composition of the present invention.

[0040] As a preferred embodiment of the foamed article of the present invention, the foaming agent includes at least one of sodium bicarbonate, azodicarbonamide and sulfonylhydrazide. The foaming agent can also be added in the form of masterbatch, and the mass percentage of the foaming agent in the foaming agent masterbatch is 15-30%.

[0041] As an embodiment of the foamed article of the present invention, the mass percentage of the foaming agent is 0.2-3% based on the foamed article. Preferably, the mass percentage of the foaming agent is 0.25-1% based on the foamed article.

[0042] In a fourth aspect of the present invention, the present invention provides application of the foamed polypropylene composition in the automotive field.

[0043] Illustratively, the foamed polypropylene composition can be used to prepare automobile door panels and instrument panels.

[0044] Compared with the prior art, the present invention has the following beneficial effects:

[0045] The invention provides a foamed polypropylene composition, which can improve the expandability of the composition by selecting a PP resin with a certain melt flow rate and compounding a high specific surface area filler, a polyhydroxy compound and a melt elasticity regulator, and can also reduce the size of the foam cells of the composition, thereby achieving high fluidity of the final product, which is beneficial to the rapid molding of injection molding and foaming. The preparation method provided by the invention is simple and easy to implement, has cost advantages, and has a high degree of design freedom. The obtained product has high expandability, fine and dense foam cells, and high fluidity when used for chemical foaming, and is suitable for high-speed molding of injection molding and foaming. DETAILED DESCRIPTION

[0046] In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0047] Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art.

[0048] PP-1: K7780, melt index 80g / 10min, Yanshan Petrochemical;

[0049] PP-2: melt index 90g / 10min, prepared by blending K7780 and BX3920 in a mass ratio of 1:1 and extruding, homemade;

[0050] PP-3: BX3900, melt index 60g / 10min, Korea SK;

[0051] PP-4: BX3920, melt index 100g / 10min, Korea SK;

[0052] PP-5: M1700, melt index 40g / 10min, LG, South Korea;

[0053] PP-6: PP7945E1, melt index 120g / 10min, ExxonMobil;

[0054] High specific surface area filler 1: Titanium dioxide, TTO-55D, Ishihara, Japan, average specific surface area of ​​75m 2 / g;

[0055] High specific surface area filler 2: Titanium dioxide, PGNR-318G, Pangang vanadium titanium, average specific surface area of ​​46m 2 / g;

[0056] High specific surface area filler 3: Fumed alumina, Alu C, Evonik Degussa, average specific surface area of ​​85m 2 / g;

[0057] High specific surface area filler 4: Titanium dioxide, CR-350, Pangang vanadium titanium, average specific surface area of ​​15m 2 / g;

[0058] Polyol 1: glyceryl monostearate, hydroxyl content 9.4%, commercially available;

[0059] Polyol 2: sorbitan monostearate, hydroxyl content 11.8%, commercially available;

[0060] Polyol 3: sorbitan monolaurate, hydroxyl content 14.7%, commercially available;

[0061] Polyol 4: distearic acid glyceryl, hydroxyl content 4.7%, commercially available;

[0062] Melt elasticity regulator 1: 1,3-2,4-di(3,4-dimethylbenzylidene) sorbitol, NA-98, Chenghe Technology, can increase the viscoelastic transition temperature of polypropylene by 36°C;

[0063] Melt elasticity regulator 2: A mixture of NA98 and NX8000K in a mass ratio of NA98:NX8000K=3:2 can increase the viscoelastic transition temperature of polypropylene by 31°C;

[0064] Melt elasticity regulator 3: 1,3-2,4-di(p-methylbenzylidene) sorbitol, 3940, Milliken, can increase the viscoelastic transition temperature of PP by 45°C;

[0065] Melt elasticity regulator 4: A mixture of NA98 and NX8000K in a mass ratio of NA98:NX8000K=3:7 can increase the viscoelastic transition temperature of polypropylene by 25°C;

[0066] Melt elasticity regulator 5: 1,3-2,4-di(4-propylbenzylidene)-1-propyl sorbitol, NX8000K, Milliken, can increase the viscoelastic transition temperature of polypropylene by 15°C;

[0067] Toughener: POE, ENGAGE 8137, Dow Chemical;

[0068] Filler: talc, TYT-777A, Beihai Group;

[0069] Antioxidant: Antioxidant 1010 and Antioxidant 168 were mixed in a mass ratio of 1:1 and were commercially available;

[0070] Light stabilizer: UV-3853, 2,2,6,6-tetramethyl-4-piperidinyl stearate, commercially available;

[0071] The toughening agent, filler, antioxidant and light stabilizer used in the parallel experiments of the embodiments and comparative examples are consistent.

[0072] The test method of viscoelastic temperature is as follows: add melt elasticity regulator to PP resin BX3920 (manufacturer is sk, South Korea) at a ratio of 0.5wt%, and obtain modified plastic particles by screw extrusion granulation, and hot press the particles into 1mm sample at 190℃, and cut out 25mm discs for rotational rheology test. The test parameters of the rotational rheometer are as follows: 25mm plate 1mm spacing, strain 2%, frequency 1rad / s, test temperature 200℃-120℃, cooling rate -5℃ / min.

[0073] Examples 1-14 and Comparative Examples 1-9

[0074] The component contents (parts by weight) of the embodiments of the present invention and the comparative examples are shown in Table 1-2;

[0075] Table 1

[0076]

[0077]

[0078] Table 2

[0079]

[0080] The preparation methods of Examples 1-14 and Comparative Examples 1-9 are:

[0081] The dried raw materials are weighed, mixed, melt-kneaded at 200-210° C., with a screw speed of 400 rpm, and then extruded and granulated to obtain a foamed polypropylene composition.

[0082] Effect example

[0083] The effect example of the present invention verifies the performance of the products prepared in Examples 1-14 and Comparative Examples 1-9; test specimens are prepared by injection molding according to the corresponding standards, and the specific preparation is as follows: the compositions prepared in Examples and Comparative Examples are subjected to a secondary mold opening injection molding experiment, specifically, the products prepared in Examples 1-14 and Comparative Examples 1-9 are mixed with a foaming agent masterbatch (sodium bicarbonate masterbatch, EE25C, the mass percentage of sodium bicarbonate in the masterbatch is 18%, Japan Yonghe) for foaming, wherein the addition amount of the foaming agent masterbatch is 2wt%, the foaming process is: 200°C, the injection speed is 140mm / s, the delayed mold opening time is 0.5S, the secondary mold opening speed is 4mm / s, and the original size of the injection molding sample is 100mm*100mm*1.8mm; and then the test is carried out, and the test items include the following aspects:

[0084] 1. Weight loss rate: 100%*(maximum foaming thickness-1.8) / maximum foaming thickness; Test method: Use a mold with an initial thickness of 1.8mm to conduct a foaming experiment, gradually increase the mold opening distance at intervals of 0.1mm, until the foamed sample produces surface collapse, then the foaming thickness of the sample at the previous mold opening distance is the maximum foaming thickness, and it is calculated according to the given calculation formula;

[0085] 2. Cell size: Cut a 50mm*50mm*2.57mm strip perpendicular to the injection flow direction in the middle, and perform brittle fracture in liquid nitrogen. Take photos with a scanning electron microscope, and perform statistical calculations with image-pro.

[0086] 3. Melt flow rate (before foaming): refer to ISO1133-2005, test conditions: 210℃, 2.16KG;

[0087] The test results are shown in Table 3;

[0088] Table 3

[0089]

[0090]

[0091] It can be seen from Table 3 that when the technical solution of the present invention is adopted, the obtained product has excellent comprehensive effects, not only can it meet the requirements of having an excellent melt flow rate, but also has a lower cell size and a larger maximum weight loss rate. Specifically, the melt index of the obtained product is between 35.3-68.2 g / 10 min, that is, it can ensure that the melt index is greater than 30 g / 10 min, the maximum weight loss rate is above 41.6%, and the cell size is below 116.5 μm;

[0092] It can be seen from Example 1 and Comparative Examples 1-4 that the high specific surface area filler, polyol and melt elasticity regulator in the composition are indispensable, and only when the three are added at the same time can an excellent comprehensive effect be achieved. When any one of the high specific surface area filler, polyol and melt elasticity regulator is missing in Comparative Examples 1-4 or none of the three are added, the pore size of the products obtained in Comparative Examples 1-4 increases by 44.18-121.70% compared with Example 1; and when the high specific surface area filler is not added in Comparative Example 1, the maximum weight loss rate of the obtained product is also significantly reduced, and the reduction is 29.65% compared with Example 1; when the high specific surface area filler, polyol and melt elasticity regulator are not added in Comparative Example 4, the maximum weight loss rate of the obtained product is significantly reduced, and the reduction is 36.83% compared with Example 1;

[0093] It can be seen from Example 1, Examples 5-7 and Comparative Examples 5-6 that the melt index of the PP resin will not only affect the melt index of the product, but also affect the foaming performance of the product. When the melt index of the PP resin is further selected to be 80-90g / 10min, the comprehensive effect of the obtained product is better. Specifically, the melt index of the obtained product is above 42.8g / 10min, the maximum weight loss rate is above 53.1%, and the pore size is below 98.5μm; when the melt index of the PP resin used in Comparative Example 5 is too low, the melt index of the obtained product is also below 30g / 10min, which cannot meet the target of a melt index greater than 30g / 10min, and the pore size of the obtained product is also significantly increased, which is 77.18% higher than that of Example 1; when the melt index of the PP resin used in Comparative Example 6 is too high, the pore size of the obtained product is significantly increased, which is 56.26% higher than that of Example 1;

[0094] It can be seen from Example 1, Examples 8-9 and Comparative Example 7 that the selection of the specific surface area of ​​the high specific surface area filler will also affect the performance of the product. When the specific surface area of ​​the high specific surface area filler is further selected to be 46-75 m 2 / g, the comprehensive effect of the obtained product is better, specifically, the melt index of the obtained product is above 41.7g / 10min, the maximum weight loss rate is above 49.8%, and the pore size is below 96.5μm; when the specific surface area of ​​the high specific surface area filler used in Comparative Example 7 is too low, the maximum weight loss rate of the obtained product is reduced by 29.65% compared with Example 1, and the pore size is increased by 40.94%;

[0095] It can be seen from Example 1, Examples 10-11 and Comparative Example 8 that the hydroxyl content in the polyol compound will also affect the performance of the product. When the hydroxyl content in the polyol compound is further selected to be 9.4-11.8%, the comprehensive effect of the obtained product is better. Specifically, the melt index of the obtained product is above 40.8g / 10min, the maximum weight loss rate is above 52.3%, and the pore size is below 97.3μm. When the hydroxyl content in Comparative Example 8 is too low, the pore size of the obtained product is increased by 72.60% compared with that in Example 1.

[0096] It can be seen from Example 1, Examples 12-14 and Comparative Example 9 that the selection of the melt elasticity regulator will affect the performance of the product. When the melt elasticity regulator is further selected so that the viscoelastic transition temperature of the polypropylene is 31-36°C, the comprehensive effect of the obtained product is better. Specifically, the melt index of the obtained product is above 42.5g / 10min, the maximum weight loss rate is above 52.4%, and the pore size is below 95.1μm. When the melt elasticity regulator selected in Comparative Example 9 cannot make the viscoelastic temperature of the PP resin transition by more than 20°C, the maximum weight loss rate of the obtained product shows a downward trend compared with that of Example 1, and the pore size is significantly increased, with an increase of 81.66%.

[0097] Finally, it should be noted that the above embodiments are intended to illustrate the technical solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention may be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A foamed polypropylene composition, characterized in that The foamed polypropylene composition comprises the following components in parts by weight: PP resin 52-98 parts, high specific surface area filler 0.3-3.2 parts, polyhydroxy compound 0.3-2.2 parts, melt elasticity regulator 0.3-2.2 parts; The average specific surface area of ​​the high specific surface area filler is greater than 40 m 2 / g; The hydroxyl content of the polyhydroxy compound is greater than 6%; The melt elasticity regulator increases the viscoelastic temperature of the PP resin by more than 20°C after being mixed with the PP resin; The melt mass flow rate of the PP resin at 230° C. and 2.16 kg is 55-105 g / 10 min; The polyol is selected from at least one of glyceryl monostearate, sorbitan monostearate, and sorbitan monolaurate; The melt elasticity regulator is a sorbitol compound.

2. The foamed polypropylene composition according to claim 1, characterized in that The average specific surface area of ​​the high surface area filler is 46-75m 2 / g; and / or, the polyol has a hydroxyl content of 9.4-11.8%; and / or, the melt elasticity modifier increases the viscoelastic temperature of the PP resin by 31-36° C. after being mixed with the PP resin; And / or, the melt mass flow rate of the PP resin at 230° C. and 2.16 kg is 80-90 g / 10 min.

3. The foamed polypropylene composition according to claim 1, characterized in that The high specific surface filler is selected from at least one of titanium dioxide, fumed alumina, porous silica gel, silicon dioxide and organic clay.

4. The foamed polypropylene composition according to claim 3, characterized in that The sorbitol compound is selected from at least one of 1,3-2,4-di(p-methylbenzylidene)sorbitol and 1,3-2,4-di(3,4-dimethylbenzylidene)sorbitol.

5. The foamed polypropylene composition according to claim 1, characterized in that The foamed polypropylene composition further comprises 0-20 parts of filler, 0-20 parts of toughening agent, and 0-1 part of auxiliary agent; The high specific surface filler is selected from at least one of titanium dioxide, fumed alumina, porous silica gel, silicon dioxide, and organic clay; The filler is selected from at least one of talc, calcium carbonate, barium sulfate and glass fiber; The auxiliary agent is selected from at least one of an antioxidant and a light stabilizer.

6. The foamed polypropylene composition according to claim 5, characterized in that: The filler is selected from at least one of talc, calcium carbonate, barium sulfate and glass fiber; And / or, the toughening agent is selected from at least one of POE, SEBS, and EPDM; And / or, the auxiliary agent is selected from at least one of an antioxidant and a light stabilizer.

7. The method for preparing the foamed polypropylene composition according to any one of claims 1 to 6, characterized in that: The preparation method comprises the following steps: weighing the dried raw materials, mixing them, melting and kneading them, and then extruding and granulating them to obtain a foamed polypropylene composition.

8. A foamed article, characterized in that: The foamed article is obtained by foaming the foamed polypropylene composition according to any one of claims 1 to 6.

9. Use of the foamed polypropylene composition according to any one of claims 1 to 6 in the automotive field.

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