An ultraviolet-resistant and anti-aging polypropylene material, a preparation method thereof and application thereof in automobile interior parts

Abstract

The application relates to the technical field of polypropylene, and discloses an ultraviolet-resistant and aging-resistant polypropylene material, a preparation method thereof and application of the polypropylene material in automobile interior parts. The polypropylene material comprises 70-90 parts by weight of polypropylene resin, 10-30 parts by weight of SBS elastomer, 0.4-1.5 parts by weight of cashew phenol-based hindered phenol antioxidant and 0.02-0.08 parts by weight of dicumyl peroxide. The cashew phenol-based hindered phenol antioxidant enhances the interfacial force between the polypropylene and the SBS elastomer, so that the SBS elastomer has better toughening effect. The cashew phenol-based hindered phenol antioxidant contains a hindered phenol structure, can be combined with a peroxide radical, terminates a chain reaction caused by thermal oxidation aging, improves the thermal aging resistance and ultraviolet aging resistance of the polypropylene, and has better practical application in high-performance automobile interior parts.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of polypropylene, in particular to an ultraviolet-resistant and aging-resistant polypropylene material, a preparation method thereof and application thereof in automotive interior parts. BACKGROUND

[0002] Polypropylene has low density, light weight, high chemical stability and good electrical insulation performance, and has important applications in the automotive industry, medical devices, packaging materials and other aspects. In order to improve the anti-aging performance of polypropylene, antioxidants such as hindered phenolic antioxidants, phosphate ester antioxidants, etc. are usually added, and the development of new high-efficiency antioxidants is a research hotspot.

[0003] Due to the poor toughness of polypropylene, toughening agents such as nanomaterials, high molecular elastomers, etc. are needed, among which styrene-butadiene-styrene triblock copolymer SBS elastomer has good mechanical strength, toughness and other properties, and has wide application in the toughening of polypropylene and other high molecular materials. However, the compatibility of SBS elastomer with polypropylene is poor, which affects the toughening effect.

[0004] Cashew phenol is a natural phenol derivative, which is cheap and easy to obtain. It contains an unsaturated carbon chain, which can react with polypropylene, nitrile rubber, polybutadiene rubber, etc. and improve the comprehensive performance of the material. Patent No. CN118927749B discloses a polypropylene synthetic paper with bright and matte surfaces and a preparation method thereof. The modified polypropylene contains hindered phenol structures and other structures, has antioxidant properties, and contains DOPO structure, melamine structure and cashew phenol-based alkane long chain flame retardant, which improves the flame retardance, water resistance and other properties. However, the patent does not improve the impact strength and toughness of polypropylene, and does not have good anti-UV aging performance. SUMMARY

[0005] In view of the deficiencies of the prior art, the present application provides an ultraviolet-resistant and aging-resistant polypropylene material and a preparation method thereof, which solves the problem of poor ultraviolet-resistant and aging-resistant performance of polypropylene.

[0006] In order to solve the above technical problems, the technical scheme adopted by the present application is as follows: an ultraviolet-resistant and aging-resistant polypropylene material and a preparation method thereof, the polypropylene material comprising 70-90 parts by weight of polypropylene resin, 10-30 parts by weight of SBS elastomer, 0.4-1.5 parts by weight of cashew phenol-based hindered phenolic antioxidant, and 0.02-0.08 parts by weight of dicumyl peroxide.

[0007] The preparation method of the polypropylene material is as follows:

[0008] (1) adding reaction solvent, cardanol dihydric alcohol, 6-(4-hydroxy-3,5-di-tert-butylphenylamino)-2,4-dichloro-1,3,5-triazine, sodium hydroxide aqueous solution into a reaction container, stirring reaction, adding ethanol into the solution for precipitation, after filtration, washing with water and ethanol, drying to obtain cardanol-based hindered phenolic antioxidant. The reaction formula is:

[0009] .

[0010] (2) mixing polypropylene resin, SBS elastomer, cardanol-based hindered phenolic antioxidant, dicumyl peroxide, extruding and granulating in a double screw extruder, then molding in a flat vulcanizing machine to obtain ultraviolet resistant and aging resistant polypropylene material.

[0011] Preferably, the reaction solvent in (1) is N,N-dimethylformamide or 1,4-dioxane.

[0012] Preferably, the mass ratio of cardanol dihydric alcohol to 6-(4-hydroxy-3,5-di-tert-butylphenylamino)-2,4-dichloro-1,3,5-triazine in (1) is 100: (88-97).

[0013] Preferably, the concentration of sodium hydroxide aqueous solution in (1) is 150-300 g / L.

[0014] Preferably, the reaction temperature in (1) is 75-90℃, and the reaction time is 24-36 h.

[0015] Preferably, the temperature of each section of the double screw extruder in (2) is 140-200℃, and the screw rotation speed is 60-100 r / min.

[0016] Preferably, the temperature of the flat vulcanizing machine in (2) is 190-200℃, and the pressure is 10-12 MPa.

[0017] Preferably, the ultraviolet resistant and aging resistant polypropylene material is applied to automotive interior parts.

[0018] (III) Beneficial technical effects: The cashew phenol dihydric alcohol and 6-(4-hydroxy-3,5-di-tert-butyl aniline)-2,4-dichloro-1,3,5-homotriazine are subjected to polymerization reaction to obtain cashew phenol hindered phenol antioxidant, which is then blended and granulated with polypropylene, SBS elastomer and dicumyl peroxide, and is subjected to mold pressing to obtain the ultraviolet resistant and anti-aging polypropylene material. The side chain of the cashew phenol hindered phenol antioxidant contains multiple unsaturated carbon chains, and a large number of unsaturated alkenyl groups are subjected to crosslinking reaction with polypropylene and SBS elastomer under the action of dicumyl peroxide, so that the polypropylene, SBS elastomer and cashew phenol hindered phenol antioxidant are subjected to chemical bond action, the interfacial force between the polypropylene and SBS elastomer is enhanced, the compatibility between the two is improved, the SBS elastomer has better toughening effect, and the impact strength of the polypropylene material is improved.

[0019] The cashew phenol hindered phenol antioxidant of the present application contains a hindered phenol structure, can capture peroxide radicals in the process of thermal oxygen aging, terminate the chain reaction caused by thermal oxygen aging, improve the thermal aging resistance of polypropylene, and a large number of alkenyl groups of the cashew phenol hindered phenol antioxidant are subjected to crosslinking reaction with polypropylene, so that the crosslinking degree of the polypropylene molecular chain is improved, the polypropylene molecular chain is not easy to break under ultraviolet radiation, which is conducive to improving the ultraviolet aging resistance, and the polypropylene maintains high impact strength and toughness after thermal oxygen aging and ultraviolet aging, and has better practical application in high-performance automotive interior parts. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is the infrared spectrum of the cashew phenol hindered phenol antioxidant. DETAILED DESCRIPTION

[0021] In order to deepen the understanding of the present application, the present application will be further described in combination with examples, and the present examples are only used to explain the present application and do not constitute a limitation on the protection scope of the present application.

[0022] The polypropylene resin is F40-03mm from Shanghai Liuzhangyang Plastic Co., Ltd. The SBS elastomer (styrene-butadiene-styrene triblock copolymer) is SBS 3546 from Dongguan Tongchuangyuan Plastic Co., Ltd.

[0023] The 6-(4-hydroxy-3,5-di-tert-butyl aniline)-2,4-dichloro-1,3,5-homotriazine is prepared according to the method of the master's degree thesis of Nanjing University of Technology, entitled "Synthesis Process Research of Antioxidant 565", and the structural formula is .

[0024] The cashew phenol dihydric alcohol is prepared according to the method of the journal "Coatings Industry", February 2017, Vol. 47, No. 2, document "Preparation and Performance of Crosslinking Cashew Phenol Based Waterborne Polyurethane", and the structural formula is n is 0-3.

[0025] Example 1

[0026] (1) Add 150 mL of N,N-dimethylformamide, 10 g (about 26.46 mmol) of cardanol diol, 9.7 g of 6-(4-hydroxy-3,5-di-tert-butylphenylamino)-2,4-dichloro-1,3,5-triazine into a reaction vessel, drop 6 mL of sodium hydroxide aqueous solution with a concentration of 200 g / L, heat to 80°C, stir for 36 h, add ethanol to the solution for precipitation, filter, wash with water and ethanol, and dry to obtain a cardanol-based hindered phenolic antioxidant. Figure 1 In the infrared spectrum of the product, 3304 cm -1 is the coupling absorption peak of hydroxyl and imino, 2851-2926 cm -1 is the stretching vibration absorption peak of methyl and methylene in the unsaturated long chain of cardanol, 974 cm -1 is the absorption peak of double bond C=C in the unsaturated long chain, 1406-1556 cm -1 is the absorption peak of benzene ring skeleton, 1448 cm -1 is the characteristic absorption peak of triazine ring, 1267 cm -1 is the characteristic peak of tert-butyl.

[0027] (2) Mix 1.8 kg of polypropylene resin, 0.2 kg of SBS elastomer, 8 g of cardanol-based hindered phenolic antioxidant, and 0.4 g of dicumyl peroxide, and extrude and granulate in a twin-screw extruder, with each section at 140°C, 170°C, 185°C, 195°C, 200°C, and 200°C, and the screw rotation speed at 60 r / min, then mold into a flat vulcanizing machine, with the temperature at 200°C and the pressure at 10 MPa, to obtain an ultraviolet-resistant and aging-resistant polypropylene material.

[0028] Example 2

[0029] (1) Add 150 mL of N,N-dimethylformamide, 10 g of cardanol diol, 8.8 g of 6-(4-hydroxy-3,5-di-tert-butylphenylamino)-2,4-dichloro-1,3,5-triazine into a reaction vessel, drop 3.5 mL of sodium hydroxide aqueous solution with a concentration of 300 g / L, heat to 75°C, stir for 36 h, add ethanol to the solution for precipitation, filter, wash with water and ethanol, and dry to obtain a cardanol-based hindered phenolic antioxidant.

[0030] (2) 1.7 kg of polypropylene resin, 0.3 kg of SBS elastomer, 15 g of cashew phenol-based hindered phenolic antioxidant, and 0.8 g of dicumyl peroxide were mixed and extruded and granulated in a twin-screw extruder, with each section being 140°C, 170°C, 185°C, 195°C, 200°C, and 200°C, and the screw rotation speed being 100 r / min, and then molded into a shape in a flat vulcanization machine, with the temperature being 190°C and the pressure being 12 MPa, to obtain an ultraviolet-resistant and anti-aging polypropylene material.

[0031] Example 3:

[0032] (1) 200 mL of 1,4-dioxane, 10 g of cashew phenol diol, and 9.2 g of 6-(4-hydroxy-3,5-di-tert-butylphenylamino)-2,4-dichloro-1,3,5-triazine were added to a reaction container, 8 mL of a sodium hydroxide aqueous solution with a concentration of 150 g / L was added dropwise, heated to 80°C, and stirred for 36 h, ethanol was added to the solution to precipitate, filtered, washed with water and ethanol, and dried to obtain a cashew phenol-based hindered phenolic antioxidant.

[0033] (2) 1.55 kg of polypropylene resin, 0.45 kg of SBS elastomer, 22 g of cashew phenol-based hindered phenolic antioxidant, and 1.2 g of dicumyl peroxide were mixed and extruded and granulated in a twin-screw extruder, with each section being 140°C, 170°C, 185°C, 195°C, 200°C, and 200°C, and the screw rotation speed being 100 r / min, and then molded into a shape in a flat vulcanization machine, with the temperature being 200°C and the pressure being 10 MPa, to obtain an ultraviolet-resistant and anti-aging polypropylene material.

[0034] Example 4:

[0035] (1) 150 mL of N,N-dimethylformamide, 10 g of cashew phenol diol, and 9.2 g of 6-(4-hydroxy-3,5-di-tert-butylphenylamino)-2,4-dichloro-1,3,5-triazine were added to a reaction container, 6 mL of a sodium hydroxide aqueous solution with a concentration of 200 g / L was added dropwise, heated to 90°C, and stirred for 24 h, ethanol was added to the solution to precipitate, filtered, washed with water and ethanol, and dried to obtain a cashew phenol-based hindered phenolic antioxidant.

[0036] (2) 1.4 kg of polypropylene resin, 0.6 kg of SBS elastomer, 30 g of cashew phenol-based hindered phenolic antioxidant, and 1.6 g of dicumyl peroxide were mixed and extruded and granulated in a twin-screw extruder, with each section being 140°C, 170°C, 185°C, 195°C, 200°C, and 200°C, and the screw rotation speed being 60 r / min, and then molded into a shape in a flat vulcanization machine, with the temperature being 200°C and the pressure being 10 MPa, to obtain an ultraviolet-resistant and anti-aging polypropylene material.

[0037] Comparative Example 1:

[0038] (2) 1.8 kg of polypropylene resin, 0.2 kg of SBS elastomer, 0.4 g of dicumyl peroxide were mixed, and extrusion granulation was performed in a twin-screw extruder, each section being 140°C, 170°C, 185°C, 195°C, 200°C, 200°C, and the screw rotation speed being 60 r / min, and then molding was performed in a flat vulcanizing machine, the temperature being 200°C and the pressure being 10 MPa, to obtain a polypropylene material.

[0039] Comparative Example 2:

[0040] (1) 1.8 kg of polypropylene resin, 0.2 kg of SBS elastomer, 8 g of cardanol, and 0.4 g of dicumyl peroxide were mixed, and extrusion granulation was performed in a twin-screw extruder, each section being 140°C, 170°C, 185°C, 195°C, 200°C, 200°C, and the screw rotation speed being 60 r / min, and then molding was performed in a flat vulcanizing machine, the temperature being 200°C and the pressure being 10 MPa, to obtain a polypropylene material.

[0041] Comparative Example 3:

[0042] (1) 1.8 kg of polypropylene resin, 0.2 kg of SBS elastomer, 8 g of 6-(4-hydroxy-3,5-di-tert-butylphenylamino)-2,4-dichloro-1,3,5-triazine, and 0.4 g of dicumyl peroxide were mixed, and extrusion granulation was performed in a twin-screw extruder, each section being 140°C, 170°C, 185°C, 195°C, 200°C, 200°C, and the screw rotation speed being 60 r / min, and then molding was performed in a flat vulcanizing machine, the temperature being 200°C and the pressure being 10 MPa, to obtain a polypropylene material.

[0043] Comparative Example 4

[0044] (1) 150 mL of N,N-dimethylformamide, 4.45 g (26.46 mmol) of 3-phenoxy-1,2-propanediol, and 9.7 g of 6-(4-hydroxy-3,5-di-tert-butylphenylamino)-2,4-dichloro-1,3,5-triazine were added to a reaction vessel, 6 mL of a 200 g / L sodium hydroxide aqueous solution was added dropwise, heated to 80°C, and stirred for 36 h, ethanol was added to the solution for precipitation, filtered, washed with water and ethanol, and dried to obtain a hindered phenolic antioxidant.

[0045] (2) 1.8 kg of polypropylene resin, 0.2 kg of SBS elastomer, 8 g of hindered phenol antioxidant, and 0.4 g of dicumyl peroxide were mixed and extruded and granulated in a twin-screw extruder, with each section being 140°C, 170°C, 185°C, 195°C, 200°C, and 200°C, and the screw rotation speed being 60 r / min, and then molded into a plate in a flat vulcanizing machine, with the temperature being 200°C and the pressure being 10 MPa, to obtain a polypropylene material.

[0046] The Izod impact strength of the polypropylene material was tested according to the method of GB / T 1843-2008.

[0047] The polypropylene material was placed in a hot air aging test box and aged at 120°C for 168 h, then left to stand at room temperature for 24 h, and then the impact strength was tested.

[0048] The polypropylene material was placed in an ultraviolet aging test box and subjected to ultraviolet aging for 240 h, with the main wavelength of the ultraviolet light being 365 nm and the radiation intensity being about 0.8 W / m 2 , then left to stand at room temperature for 24 h, and then the impact strength was tested.

[0049] Table 1 Performance test of polypropylene material

[0050]

[0051] The impact strength of the polypropylene material of the comparative example was low, mainly because the compatibility of the SBS elastomer with the polypropylene was poor, the toughening effect was not good, and the impact strength retention rate of the polypropylene material after thermal aging and ultraviolet aging was low, and the thermal aging resistance and ultraviolet aging resistance were poor.

[0052] The cashew phenolic hindered phenol antioxidant was added to the polypropylene material of each example, the polymer contained multiple unsaturated carbon chains, and a large number of unsaturated alkenyl groups were crosslinked with the polypropylene and the SBS elastomer under the action of dicumyl peroxide, thereby chemically bonding the polypropylene, the SBS elastomer, and the cashew phenolic hindered phenol antioxidant, enhancing the interfacial force between the polypropylene and the SBS elastomer, improving the compatibility between them, making the SBS elastomer have better toughening effect, and improving the impact strength of the polypropylene material. Moreover, the cashew phenolic hindered phenol antioxidant contains a hindered phenol structure, which can combine with peroxide radicals to terminate the chain reaction caused by thermal oxidation, thereby improving the thermal aging resistance of the polypropylene. In addition, a large number of alkenyl groups of the cashew phenolic hindered phenol antioxidant are crosslinked with the polypropylene, thereby improving the crosslinking degree of the polypropylene molecular chain, which is not easy to break during ultraviolet radiation, thereby improving the ultraviolet aging resistance. After thermal oxidation and ultraviolet aging, the polypropylene maintains a very high impact strength and toughness.

[0053] Comparative Example 2 only added cardanol which only contains one unsaturated carbon chain, and it is difficult to cross-link with SBS elastomer and polypropylene at the same time, and it does not have good compatibility between SBS elastomer and polypropylene, resulting in poor toughening effect of SBS elastomer, low impact strength of polypropylene material, and cardanol also does not contain hindered phenol structure, low impact strength retention of the material after heat aging, poor heat aging resistance, and low ultraviolet aging resistance.

[0054] Comparative Example 3 only added 6-(4-hydroxy-3,5-di-tert-butylphenylamino)-2,4-dichloro-1,3,5-triazine as an antioxidant, which does not contain an alkenyl group, and cannot cross-link with polypropylene and SBS elastomer, and cannot improve the compatibility between polypropylene and SBS elastomer, resulting in low impact strength of the material, and low impact strength retention of the material after ultraviolet aging.

[0055] The hindered phenol antioxidant of 3-phenoxy-1,2-propanediol of Comparative Example 4 and its preparation does not contain an unsaturated carbon chain, and cannot cross-link with polypropylene and SBS elastomer, and cannot improve the compatibility between polypropylene and SBS elastomer, resulting in low impact strength of the material, and low impact strength retention of the material after ultraviolet aging.

[0056] The above shows and describes the basic principles, main features and advantages of the present application. Those skilled in the art should understand that the present application is not limited by the above examples, and the above examples and descriptions in the specification are only to illustrate the principles of the present application, and various changes and improvements can be made without departing from the spirit and scope of the present application, and these changes and improvements all fall within the scope of the claimed present application.

Claims

1. An ultraviolet resistant, weatherable polypropylene material, characterized in that, The polypropylene material comprises 70-90 parts by weight of polypropylene resin, 10-30 parts by weight of SBS elastomer, 0.4-1.5 parts by weight of cardanol-based hindered phenolic antioxidant, and 0.02-0.08 parts by weight of dicumyl peroxide. The preparation method of the cardanol-based hindered phenolic antioxidant comprises the following steps: adding a reaction solvent, cardanol diol, 6-(4-hydroxy-3,5-di-tert-butylphenylamino)-2,4-dichloro-1,3,5-homotriazine, and an aqueous sodium hydroxide solution into a reaction container, stirring the reaction, adding ethanol into the solution for precipitation, washing after filtration, drying, and obtaining the cardanol-based hindered phenolic antioxidant.

2. The anti-UV, age-resistant polypropylene material according to claim 1, characterized in that, The reaction solvent is N,N-dimethylformamide or 1,4-dioxane.

3. The anti-UV, age-resistant polypropylene material according to claim 1, characterized in that, The mass ratio of the cardanol diol and 6-(4-hydroxy-3,5-di-tert-butylphenylamino)-2,4-dichloro-1,3,5-homotriazine is 100: (88-97).

4. The anti-UV, age-resistant polypropylene material according to claim 1, characterized in that, The concentration of the aqueous sodium hydroxide solution is 150-300 g / L.

5. The anti-UV, age-resistant polypropylene material according to claim 1, characterized in that, The reaction temperature is 75-90℃, and the reaction time is 24-36 h.

6. A process for the preparation of an anti-UV weatherable polypropylene material according to any one of claims 1-5, characterized in that, The preparation method comprises the following steps: mixing the polypropylene resin, the SBS elastomer, the cardanol-based hindered phenolic antioxidant, and the dicumyl peroxide, extruding and granulating in a double-screw extruder, and then molding in a flat vulcanizing machine to obtain the anti-ultraviolet and aging-resistant polypropylene material.

7. The method for preparing the UV-resistant and aging-resistant polypropylene material according to claim 6, characterized in that, The temperature of each section of the double-screw extruder is 140-200℃, and the screw rotation speed is 60-100 r / min.

8. The method for preparing the UV-resistant and aging-resistant polypropylene material according to claim 7, characterized in that, The temperature of the flat vulcanizing machine is 190-200℃, and the pressure is 10-12 MPa.

9. Use of the anti-ultraviolet and aging-resistant polypropylene material obtained by the preparation method of any one of claims 6-8 in automobile interior parts.

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