High-weatherability spectrum plastic particle and preparation method thereof

Abstract

The invention relates to the technical field of high polymer materials, and discloses a high-weather-resistance spectral plastic particle and a preparation method thereof.The high-weather-resistance spectral plastic particle is prepared from, by weight, 160-185 parts of polypropylene, 15-25 parts of modified white carbon black, 5-10 parts of a composite flame retardant, 20-40 parts of a flexibilizer and 3-5 parts of a lubricant, the modified white carbon black is a nano-silica grafted triazine derivative, and the composite flame retardant is a flame retardant. The triazine derivative comprises a hindered amine structure, a benzophenone structure and a siloxane structure, the flame retardant property of the material is improved by adding the composite flame retardant, and the mechanical property and light stability of the material are improved by adding the modified white carbon black, so that the material has relatively strong weather resistance.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer materials, and in particular relates to high-weather-resistant spectral plastic particles and a preparation method thereof. Background Art

[0002] Polypropylene is one of the most widely used general-purpose plastics, with a density of 0.9g / cm 3 , the emulsification temperature is 155℃, the melting point is 189℃, the glass transition temperature is lower than -30℃, and it can be used in a wide temperature range. It has the characteristics of light density, excellent processing performance, stable physical and chemical properties, and low price. In addition, its molecular chain is completely composed of carbon and hydrogen elements, which is easy to recycle and conforms to the environmental protection concept of "carbon neutrality". In recent years, with the rapid development of automobile, electronic and other technologies, the consumption of polypropylene has increased year by year.

[0003] Although polypropylene has excellent performance, its molecular chain structure is single. Under the influence of ultraviolet rays, heat and oxygen, it is easy to produce yellowing and stickiness in appearance, and the mechanical properties decrease, which limits its application range. Therefore, polypropylene needs to be chemically and physically modified to improve weather resistance.

[0004] Therefore, in order to delay the changes in the structure and properties of polypropylene under light aging, different types of light stabilizers and antioxidants are usually used to improve its weather resistance, mainly including UV absorbers, excited state quenchers, light shielding agents and free radical scavengers, etc. However, these small molecule additives are easy to migrate and precipitate, and cannot maintain the long-term anti-aging effect of polypropylene materials. At the same time, the addition of a large amount of additives will also lead to a decrease in the mechanical properties of the material. Summary of the invention

[0005] In order to solve the deficiencies mentioned in the above background technology, the purpose of the present invention is to provide a high weather resistance spectral plastic particle and a preparation method thereof. By adding a composite flame retardant, the flame retardant properties of the material are improved. By adding modified silica, the mechanical properties and light stability of the material are improved, so that it has strong weather resistance.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] A high-weather-resistant spectrum plastic particle, the high-weather-resistant spectrum plastic particle comprises the following raw materials in parts by weight: 160-185 parts of polypropylene, 15-25 parts of modified white carbon black, 5-10 parts of composite flame retardant, 20-40 parts of toughening agent, and 3-5 parts of lubricant;

[0008] The modified white carbon black is a nano-silicon dioxide grafted triazine derivative, the triazine derivative contains a hindered amine structure, a benzophenone structure and a siloxane structure, and the structural formula of the triazine derivative is as follows:

[0009]

[0010] More preferably, the toughening agent is one of ethylene-octene copolymer, ethylene-vinyl acetate copolymer or ethylene propylene diene monomer rubber.

[0011] More preferably, the lubricant is one or more of stearate, paraffin and polyethylene wax.

[0012] Further preferably, the composite flame retardant is a mixture of aluminum hydroxide, ammonium polyphosphate, pentaerythritol and melamine in a mass ratio of 1:0.5:0.2:0.2.

[0013] Further preferably, the preparation method of modified silica comprises the following steps:

[0014] (1) Add cyanuric chloride to tetrahydrofuran and triethylamine under a nitrogen atmosphere, stir to dissolve the cyanuric chloride, then uniformly add 3-aminopropyltriethoxysilane dropwise, react in an ice bath for 1 to 3 hours after the addition is complete, then add 2,2,6,6-tetramethylpiperidinamine to the reaction system, heat to 30°C, keep warm for 2 to 4 hours, then add 3-aminobenzophenone to the reaction system, heat to 60°C, and keep warm for 2 to 4 hours;

[0015] (2) After the reaction is completed, cool and filter to remove triethylamine hydrochloride, remove tetrahydrofuran by vacuum distillation, wash with deionized water 3 to 5 times, add ethyl acetate to the separated organic phase, dry and filter, and vacuum distill the filtrate to obtain a triazine derivative;

[0016] (3) Add nano-silica to 95 vol% ethanol aqueous solution, ultrasonically disperse for 10 to 15 minutes, adjust the solution pH to 4 with hydrochloric acid aqueous solution, then slowly add the triazine derivative to the nano-silica dispersion, continue ultrasonically dispersing for 5 to 10 minutes, heat to 60 to 80°C and keep the reaction for 3 to 5 hours, filter after cooling, wash and dry to obtain modified white carbon black.

[0017] Further preferably, in step (1), the molar ratio of cyanuric chloride, 3-aminopropyltriethoxysilane, 2,2,6,6-tetramethylpiperidinamine and 3-aminobenzophenone is 1:1:1:1.

[0018] Further preferably, in step (3), the nano-silicon dioxide is added to the ethanol aqueous solution at a solid-liquid ratio of 1:5-8, and the mass ratio of the triazine derivative to the nano-silicon dioxide is 1:4-6.

[0019] A method for preparing high-weather-resistant spectral plastic particles comprises the following steps:

[0020] S1, adding polypropylene, toughening agent and lubricant into a high mixing pot and mixing them thoroughly, then melting, plasticizing and blending the mixture through a twin-screw extruder, and extruding and granulating to obtain polymer particles;

[0021] S2. Add the polymer particles, modified silica and composite flame retardant into a high mixing pot for premixing, then melt and blend the mixture through a twin-screw extruder, extrude and granulate the mixture, and obtain high weather resistance spectrum plastic particles after drying.

[0022] Beneficial effects of the present invention:

[0023] The high weather-resistant spectrum plastic particles of the present invention greatly improve the light stability of the material by adding modified white carbon black, so that the material has strong weather resistance. The modified white carbon black adopts the triazine derivative grafted on the surface of nano-silicon dioxide, which can improve the dispersibility of nano-silicon dioxide in the polymer, and the hindered amine group and benzophenone structure contained in the triazine derivative, the benzophenone structure has the effect of absorbing ultraviolet light, and the hindered amine has the effect of capturing free radicals, the two synergistically enhance the light stability of the material with dual protection in light aging. DETAILED DESCRIPTION

[0024] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] Example 1

[0026] A modified white carbon black is prepared by grafting a triazine derivative with nano-silicon dioxide. The triazine derivative contains a hindered amine structure, a benzophenone structure and a siloxane structure. The structural formula of the triazine derivative is as follows:

[0027]

[0028] The above-mentioned modified silica preparation method comprises the following steps:

[0029] (1) Under a nitrogen atmosphere, 1.85 g of cyanuric chloride was added to 20 ml of tetrahydrofuran and 15 ml of triethylamine, and the cyanuric chloride was dissolved by stirring. Then, 2.2 g of 3-aminopropyltriethoxysilane was added dropwise at a uniform rate. After the addition was completed, the mixture was reacted in an ice bath for 23 h. Then, 1.6 g of 2,2,6,6-tetramethylpiperidinamine was added to the reaction system, and the mixture was heated to 30° C. and kept warm for 3 h. Then, 2.0 g of 3-aminobenzophenone was added to the reaction system, and the mixture was heated to 60° C. and kept warm for 3 h.

[0030] (2) After the reaction is completed, cool and filter to remove triethylamine hydrochloride, remove tetrahydrofuran by vacuum distillation, wash with deionized water 3 to 5 times, add ethyl acetate to the separated organic phase, dry and filter, and vacuum distill the filtrate to obtain a triazine derivative;

[0031] (3) 5.2 g of nano-silica was added to 40 ml of 95 vol% ethanol aqueous solution, and ultrasonically dispersed for 12 min. The pH of the solution was adjusted to 4 with hydrochloric acid aqueous solution, and then 1.1 g of triazine derivative was slowly added to the nano-silica dispersion, and ultrasonic dispersion was continued for 8 min. The mixture was heated to 70° C. and kept warm for 4 h. After cooling, the mixture was filtered, washed, and dried to obtain modified white carbon black.

[0032] Example 2

[0033] A high weather resistance spectrum plastic particle comprises the following raw materials in parts by weight: 160 parts of polypropylene, 25 parts of modified white carbon black, 5 parts of a composite flame retardant, 40 parts of ethylene-octene copolymer, and 3 parts of polyethylene wax; the composite flame retardant is a mixture of aluminum hydroxide, ammonium polyphosphate, pentaerythritol, and melamine in a mass ratio of 1:0.5:0.2:0.2, and the modified white carbon black is a nano-silicon dioxide grafted triazine derivative prepared in Example 1.

[0034] The method for preparing the above-mentioned high weather resistance spectrum plastic particles comprises the following steps:

[0035] S1, adding polypropylene, ethylene-octene copolymer and polyethylene wax into a high mixing pot and mixing them thoroughly, then melting, plasticizing and blending the mixture through a twin-screw extruder, and extruding and granulating to obtain polymer particles;

[0036] S2. Add the polymer particles, modified silica and composite flame retardant into a high mixing pot for premixing, then melt and blend the mixture through a twin-screw extruder, extrude and granulate the mixture, and obtain high weather resistance spectrum plastic particles after drying.

[0037] Example 3

[0038] A high weather resistance spectrum plastic particle comprises the following raw materials in parts by weight: 185 parts of polypropylene, 15 parts of modified white carbon black, 10 parts of a composite flame retardant, 20 parts of ethylene-vinyl acetate copolymer, and 5 parts of paraffin; the composite flame retardant is a mixture of aluminum hydroxide, ammonium polyphosphate, pentaerythritol, and melamine in a mass ratio of 1:0.5:0.2:0.2, and the modified white carbon black is a nano-silicon dioxide grafted triazine derivative prepared in Example 1.

[0039] The method for preparing the above-mentioned high weather resistance spectrum plastic particles comprises the following steps:

[0040] S1, adding polypropylene, ethylene-vinyl acetate copolymer and paraffin into a high mixing pot and mixing them thoroughly, then melting, plasticizing and blending the mixture through a twin-screw extruder, and extruding and granulating to obtain polymer particles;

[0041] S2. Add the polymer particles, modified silica and composite flame retardant into a high mixing pot for premixing, then melt and blend the mixture through a twin-screw extruder, extrude and granulate the mixture, and obtain high weather resistance spectrum plastic particles after drying.

[0042] Example 4

[0043] A high weather resistance spectrum plastic particle comprises the following raw materials in parts by weight: 172 parts of polypropylene, 20 parts of modified white carbon black, 8 parts of a composite flame retardant, 30 parts of EPDM rubber, and 4 parts of sodium stearate; the composite flame retardant is a mixture of aluminum hydroxide, ammonium polyphosphate, pentaerythritol, and melamine in a mass ratio of 1:0.5:0.2:0.2, and the modified white carbon black is a nano-silicon dioxide grafted triazine derivative prepared in Example 1.

[0044] The method for preparing the above-mentioned high weather resistance spectrum plastic particles comprises the following steps:

[0045] S1, adding polypropylene, EPDM rubber and sodium stearate into a high mixing pot and mixing them thoroughly, then melting, plasticizing and blending the mixture through a twin-screw extruder, and extruding and granulating to obtain polymer particles;

[0046] S2. Add the polymer particles, modified silica and composite flame retardant into a high mixing pot for premixing, then melt and blend the mixture through a twin-screw extruder, extrude and granulate the mixture, and obtain high weather resistance spectrum plastic particles after drying.

[0047] Comparative Example 1

[0048] A high weather-resistant spectral plastic particle comprises the following raw materials in parts by weight: 172 parts of polypropylene, 20 parts of white carbon black, 8 parts of a composite flame retardant, 30 parts of EPDM rubber, and 4 parts of sodium stearate; the composite flame retardant is a mixture of aluminum hydroxide, ammonium polyphosphate, pentaerythritol, and melamine in a mass ratio of 1:0.5:0.2:0.2.

[0049] The method for preparing the above-mentioned high weather resistance spectrum plastic particles comprises the following steps:

[0050] S1, adding polypropylene, EPDM rubber and sodium stearate into a high mixing pot and mixing them thoroughly, then melting, plasticizing and blending the mixture through a twin-screw extruder, and extruding and granulating to obtain polymer particles;

[0051] S2. Add the polymer particles, white carbon black and composite flame retardant into a high mixing pot for premixing, then melt and blend the mixture through a twin-screw extruder, extrude and granulate the mixture, and obtain high weather resistance spectrum plastic particles after drying.

[0052] Performance Testing

[0053] The high weather resistance spectrum plastic particles prepared in Examples 2 to 4 and Comparative Example 1 were cut into 30 mm × 30 mm samples, placed in a UV light box for accelerated aging, and a light stability performance test was performed. Samples were taken every 10 hours to test the tensile strength. The tensile strength test was carried out in accordance with GB / T 528-2009. The molded samples were cut into 25 mm × 4 mm dumbbell-shaped tensile strips. The stretching rate was 20 mm / min. The tensile strength retention rate was calculated by comparing with the initial tensile strength. The data obtained are shown in Table 1 below.

[0054] Table 1 Test results of photostability of high weather resistance spectrum plastic particles

[0055]

[0056] It can be seen from the data in Table 1 that the tensile strength of the high weather resistance spectrum plastic particles in Comparative Example 1 after ultraviolet accelerated aging decreases more than that of other groups, indicating that the light stability of the material without the modified silica of the present invention is worse than that of other groups. The modified silica of the present invention adopts the triazine derivative grafted on the surface of nano-silicon dioxide to improve the dispersibility of nano-silicon dioxide in the polymer, and the hindered amine group and benzophenone structure contained in the triazine derivative, the benzophenone structure has the effect of absorbing ultraviolet light, and the hindered amine has the effect of capturing free radicals, the two synergistically enhance the light stabilization effect of the dual protection material in light aging, and thus can greatly improve the weather resistance of the material.

[0057] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0058] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of the present invention to be protected.

Claims

1. A high weather resistance spectrum plastic particle, characterized in that: The high weather-resistant spectrum plastic particles include the following raw materials in parts by weight: 160-185 parts of polypropylene, 15-25 parts of modified white carbon black, 5-10 parts of composite flame retardant, 20-40 parts of toughening agent, and 3-5 parts of lubricant; The modified white carbon black is a nano-silicon dioxide grafted triazine derivative, the triazine derivative contains a hindered amine structure, a benzophenone structure and a siloxane structure, and the structural formula of the triazine derivative is as follows:

2. The high weather resistance spectrum plastic particles according to claim 1, characterized in that: The toughening agent is one of ethylene-octene copolymer, ethylene-vinyl acetate copolymer or ethylene propylene diene monomer rubber.

3. The high weather resistance spectrum plastic particles according to claim 1, characterized in that: The lubricant is one or more of stearate, paraffin and polyethylene wax.

4. The high weather resistance spectrum plastic particles according to claim 1, characterized in that: The composite flame retardant is prepared by mixing aluminum hydroxide, ammonium polyphosphate, pentaerythritol and melamine in a mass ratio of 1:0.5:0.2:0.

2.

5. The high weather resistance spectrum plastic particles according to claim 1, characterized in that: The preparation method of the modified white carbon black comprises the following steps: (1) Add cyanuric chloride to tetrahydrofuran and triethylamine under a nitrogen atmosphere, stir to dissolve the cyanuric chloride, then uniformly add 3-aminopropyltriethoxysilane dropwise, react in an ice bath for 1 to 3 hours after the addition is complete, then add 2,2,6,6-tetramethylpiperidinamine to the reaction system, heat to 30°C, keep warm for 2 to 4 hours, then add 3-aminobenzophenone to the reaction system, heat to 60°C, and keep warm for 2 to 4 hours; (2) After the reaction is completed, cool and filter to remove triethylamine hydrochloride, remove tetrahydrofuran by vacuum distillation, wash with deionized water 3 to 5 times, add ethyl acetate to the separated organic phase, dry and filter, and vacuum distill the filtrate to obtain a triazine derivative; (3) Add nano-silica to 95 vol% ethanol aqueous solution, ultrasonically disperse for 10 to 15 minutes, adjust the solution pH to 4 with hydrochloric acid aqueous solution, then slowly add the triazine derivative to the nano-silica dispersion, continue ultrasonically dispersing for 5 to 10 minutes, heat to 60 to 80°C and keep the reaction for 3 to 5 hours, filter after cooling, wash and dry to obtain modified white carbon black.

6. The high weather resistance spectrum plastic particles according to claim 5, characterized in that: In the step (1), the molar ratio of cyanuric chloride, 3-aminopropyltriethoxysilane, 2,2,6,6-tetramethylpiperidinamine and 3-aminobenzophenone is 1:1:1:

1.

7. The high weather resistance spectrum plastic particles according to claim 5, characterized in that: In the step (3), nano silicon dioxide is added to the ethanol aqueous solution at a solid-liquid ratio of 1:5-8, and the mass ratio of the triazine derivative to the nano silicon dioxide is 1:4-6.

8. The method for preparing high weather resistance spectrum plastic particles according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1, adding polypropylene, toughening agent and lubricant into a high mixing pot and mixing them thoroughly, then melting, plasticizing and blending the mixture through a twin-screw extruder, and extruding and granulating to obtain polymer particles; S2. Add the polymer particles, modified silica and composite flame retardant into a high mixing pot for premixing, then melt and blend the mixture through a twin-screw extruder, extrude and granulate the mixture, and obtain high weather resistance spectrum plastic particles after drying.

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