Polypropylene modified plastic and preparation method thereof

Abstract

The invention belongs to the technical field of high polymer materials. The invention relates to the field of plastics, in particular to polypropylene modified plastic and a preparation method thereof. The product provided by the invention comprises the following raw materials in parts by weight: 100-110 parts of polypropylene resin, 20-22 parts of an organophosphorus flame retardant, 10-12 parts of hollow spherical calcium carbonate particles, 0.8-1.2 parts of an antioxidant and 0.2-0.3 part of a plasticizer. Wherein the sphericity degree of the hollow spherical calcium carbonate is 8.5 to 9.0; in addition, the D50 of the hollow spherical calcium carbonate is 45-60 [mu] m. When the hollow spherical calcium titanate is prepared, sodium carbonate, calcium chloride and an emulsifier solution are rapidly stirred to react, centrifugal separation is performed, and then washing, drying, calcining, cooling and screening are performed to obtain the hollow spherical calcium titanate. On the basis of reducing the migration of the flame retardant, the product provided by the invention can reduce the adverse effect of the filler on the flame-retardant effect.

Description

Technical Field

[0001] The present invention belongs to the technical field of polymer materials and more specifically relates to a polypropylene modified plastic and a preparation method thereof. Background Art

[0002] Polypropylene (PP) is a widely used base polymer in the world. Due to its moderate pressure / temperature polymerization conditions and excellent anti-hygroscopicity, it has been widely used in packaging, textiles, industry and various electronic devices. However, like other high molecular polymers, its inherent flammability has caused serious damage to human property and life safety. Therefore, it is necessary to modify PP to improve its fire safety performance.

[0003] Adding phosphorus-containing flame retardants to PP plastics is a relatively effective method. However, phosphorus-containing flame retardants, especially organic flame retardants, are likely to escape from the material and enter the environment during use. Specifically, they can enter the atmosphere, water bodies and soil through gas phase, water phase and solid phase transfer. These migration pathways may cause the loss or uneven distribution of flame retardants, thereby reducing their flame retardant effect on PP plastics. Summary of the invention

[0004] The technical problem to be solved by the present invention is that when an organophosphorus flame retardant is added to polypropylene plastic to improve its flame retardant properties, the flame retardant is easily migrated or escaped, thereby causing the flame retardant properties of the plastic to decrease. The present invention provides a polypropylene modified plastic and a preparation method thereof.

[0005] The purpose of the present invention is to provide a polypropylene modified plastic.

[0006] Another object of the present invention is to provide a method for preparing polypropylene modified plastics.

[0007] The above-mentioned purpose of the present invention is achieved through the following technical solutions:

[0008] A polypropylene modified plastic comprises the following raw materials in parts by weight:

[0009] 100-110 parts of polypropylene resin, 20-22 parts of organic phosphorus flame retardant, 10-12 parts of hollow spherical calcium carbonate particles, 0.8-1.2 parts of antioxidant, 0.2-0.3 parts of plasticizer;

[0010] Wherein, the sphericity of the hollow spherical calcium carbonate is 8.5-9.0; and the D50 of the hollow spherical calcium carbonate is 45-60 μm.

[0011] Beneficial effects of the above technical solution:

[0012] By using organic phosphorus as a flame retardant for polypropylene plastic, during high-temperature heating, the organic phosphorus compound can form a non-combustible protective film on the surface of the plastic during combustion, which plays a role in isolating air and preventing heat transfer, ultimately achieving the purpose of flame retardancy;

[0013] The above technical solution slows down the migration or escape of the flame retardant by adding a certain amount of calcium carbonate as a filler. This is mainly because after a certain amount of addition, the density can be improved in the PP plastic matrix, and a diffusion barrier of the organophosphorus flame retardant can be dispersed to form, thereby helping to reduce the volatilization and migration of the organophosphorus flame retardant.

[0014] However, the inventors have found that the addition of calcium carbonate will make it difficult to form the protective film during the flame retardant process, thereby adversely affecting the flame retardant effect.

[0015] By adjusting the calcium carbonate to be hollow spherical calcium carbonate particles, on the one hand, the hollow structure has a lower density and a higher porosity, so that it can have a better heat insulation ability, which helps to slow down the heat transfer to the inside of the PP material during the flame retardant process, and provide more time for the formation and maintenance of the protective film;

[0016] The hollow spherical calcium carbonate can also improve the fluidity of the PP melt during processing, which helps to improve the uniformity of the dispersion of the flame retardant in the PP material, thereby facilitating the uniform formation of the protective layer.

[0017] In addition, the inventors found that the introduction of hollow spherical calcium carbonate, during the storage or normal use of PP plastic, its hollow structure can also prevent the heat from affecting the inside of the plastic matrix, play a certain heat isolation effect, and also prevent the volatilization of flame retardants.

[0018] Furthermore, the surface of the hollow spherical calcium carbonate is coated with a coupling agent;

[0019] The coupling agent is selected from any one of a silane coupling agent, a phthalate coupling agent or an aluminate coupling agent.

[0020] Beneficial effects of the above scheme:

[0021] By further coating the surface of the hollow spherical calcium carbonate with a coupling agent, the interfacial compatibility of the inorganic filler with plastics or organic flame retardants can be significantly improved, thereby further improving the uniformity of dispersion of various materials within the system and the interaction between them.

[0022] Furthermore, the organic phosphorus flame retardant is selected from any one of ammonium polyphosphate, aluminum hypophosphite, tributyl phosphate, triphenyl phosphate, tri(β-chloroethyl) phosphate, and dimethyl methyl phosphate.

[0023] Furthermore, the antioxidant is selected from any one of antioxidant 168, antioxidant 626, antioxidant 1010, antioxidant 1076 or antioxidant 3114.

[0024] Furthermore, the plasticizer is selected from any one of dioctyl phthalate, dibutyl phthalate, dioctyl adipate or n-octyl-n-decyl adipate.

[0025] A method for preparing polypropylene modified plastic, the specific preparation steps comprising:

[0026] Preparation of hollow spherical calcium carbonate:

[0027] The sodium carbonate solution and the calcium chloride solution are mixed, and an emulsifier is added, and the mixture is rapidly stirred for reaction, and then centrifuged to collect the precipitate, and the precipitate is washed and dried, and then calcined at a temperature of 340-350°C, cooled, discharged, and sieved to obtain hollow spherical calcium carbonate;

[0028] Coating of coupling agent:

[0029] Ultrasonic dispersion of hollow spherical calcium carbonate in an ethanol solution, adding a coupling agent, heating and stirring for reaction, filtering, washing and drying to obtain a coupling agent-coated hollow spherical calcium carbonate;

[0030] Preparation of polypropylene modified plastics:

[0031] Weigh each component according to the raw material composition, dry and remove moisture, and mix them evenly in a mixer;

[0032] The polypropylene modified plastic is obtained by extruding and cooling.

[0033] Furthermore, the emulsifier is selected from any one of sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, hexadecyltrimethylammonium bromide, and octadecyldimethylbenzyl ammonium chloride.

[0034] Furthermore, the preparation of the hollow spherical calcium carbonate includes:

[0035] A calcium chloride solution with a concentration of 0.15-0.18 mol / L and an emulsifier solution with a concentration of 0.06-0.08 mol / L are mixed uniformly in a volume ratio of 1:1 to obtain a mixed solution; then, a sodium carbonate solution with a volume equal to that of the mixed solution is added under stirring, and the concentration of the sodium carbonate solution is 1.01-1.03 times that of the calcium chloride solution; after the addition is completed, the stirring reaction is continued for 30-40 minutes;

[0036] Centrifuge to collect the precipitate, wash the precipitate with deionized water until the washing liquid is neutral, and then dry the washed precipitate at 90°C to constant weight to obtain a dry precipitate;

[0037] The dried precipitate is transferred into a muffle furnace, heated to 340-350°C at a rate of 2-4°C / min, kept warm and calcined for 60-80 minutes, cooled to room temperature with the furnace, discharged, and sieved to obtain hollow spherical calcium carbonate.

[0038] Furthermore, the stirring state is: at a stirring speed of 2200-2500r / min.

[0039] Beneficial effects of the above scheme:

[0040] By using calcium chloride and sodium carbonate in the presence of an emulsifier and rapid stirring and emulsification, hollow spherical calcium carbonate is formed, and then calcination is used to remove the residual emulsifier on the surface to avoid its adverse effect on the processing of plastics. DETAILED DESCRIPTION

[0041] The present invention is further described below with reference to specific examples, but the examples do not limit the present invention in any form. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art.

[0042] Unless otherwise specified, the reagents and materials used in the following examples are commercially available.

[0043] Example 1

[0044] Preparation of hollow spherical calcium carbonate:

[0045] A calcium chloride solution with a concentration of 0.15 mol / L and an emulsifier solution with a concentration of 0.06 mol / L were mixed uniformly in a volume ratio of 1:1 to obtain a mixed solution; then, a sodium carbonate solution with a volume equal to that of the mixed solution was added at a stirring speed of 2200 r / min, and the concentration of the sodium carbonate solution was 1.01 times that of the calcium chloride solution; after the addition was completed, the stirring reaction was continued for 30 minutes;

[0046] Centrifuge to collect the precipitate, wash the precipitate with deionized water until the washing liquid is neutral, and then dry the washed precipitate at 90°C to constant weight to obtain a dry precipitate;

[0047] The dried precipitate was transferred into a muffle furnace, heated to 340°C at a rate of 2°C / min, kept at this temperature for calcination for 60 minutes, cooled to room temperature with the furnace, discharged, and sieved to obtain hollow spherical calcium carbonate;

[0048] The sphericity of the hollow spherical calcium carbonate is 8.5; and the D50 of the hollow spherical calcium carbonate is 45 μm;

[0049] Coating of coupling agent:

[0050] The hollow spherical calcium carbonate and the 70% ethanol solution by mass fraction were mixed in a mass ratio of 1:8, and ultrasonically dispersed for 10 minutes at an ultrasonic frequency of 100kHz, and then a coupling agent of 6% by mass of the hollow spherical calcium carbonate was added, and then heated and stirred for 2 hours at a temperature of 65°C and a stirring speed of 800r / min, and then filtered to collect the filter cake, and the filter cake was washed with deionized water for 3 times, and then dried at a temperature of 85°C for 12 hours to obtain the coupling agent-coated hollow spherical calcium carbonate;

[0051] Preparation of polypropylene modified plastics:

[0052] Weigh each component according to the raw material composition. Specifically, the raw materials are weighed according to the following weight parts:

[0053] 100 parts of polypropylene resin, 20 parts of organic phosphorus flame retardant, 10 parts of hollow spherical calcium carbonate particles, 0.8 parts of antioxidant, 0.2 parts of plasticizer;

[0054] After drying the above raw materials to remove moisture, pour them into a mixer and mix them evenly in the mixer;

[0055] The polypropylene modified plastic is obtained by extruding and molding with a twin-screw extruder and cooling.

[0056] When the extruder is used for processing, the temperature of the extruder section is regulated to be 178°C, the temperature of the melting section is 195°C, and the temperature of the homogenizing section is 205°C.

[0057] The coupling agent is selected from silane coupling agents;

[0058] The organophosphorus flame retardant is selected from tributyl phosphate;

[0059] The antioxidant is selected from antioxidant 168;

[0060] The plasticizer is selected from dioctyl phthalate.

[0061] Example 2

[0062] Preparation of hollow spherical calcium carbonate:

[0063] A calcium chloride solution with a concentration of 0.16 mol / L and an emulsifier solution with a concentration of 0.07 mol / L were mixed uniformly in a volume ratio of 1:1 to obtain a mixed solution; then, a sodium carbonate solution with a volume equal to that of the mixed solution was added at a stirring speed of 2300 r / min, and the concentration of the sodium carbonate solution was 1.02 times that of the calcium chloride solution; after the addition was completed, the stirring reaction was continued for 35 minutes;

[0064] Centrifuge to collect the precipitate, wash the precipitate with deionized water until the washing liquid is neutral, and then dry the washed precipitate at 90°C to constant weight to obtain a dry precipitate;

[0065] The dried precipitate was transferred into a muffle furnace, heated to 345°C at a rate of 3°C / min, kept at this temperature for 70 minutes, cooled to room temperature with the furnace, discharged, and sieved to obtain hollow spherical calcium carbonate;

[0066] The sphericity of the hollow spherical calcium carbonate is 8.8; and the D50 of the hollow spherical calcium carbonate is 50 μm;

[0067] Coating of coupling agent:

[0068] The hollow spherical calcium carbonate and the 70% ethanol solution by mass fraction were mixed in a mass ratio of 1:8, and ultrasonically dispersed for 10 minutes at an ultrasonic frequency of 100kHz, and then a coupling agent of 7% by mass of the hollow spherical calcium carbonate was added, and then heated and stirred for 2 hours at a temperature of 65°C and a stirring speed of 800r / min, and then filtered to collect the filter cake, and the filter cake was washed with deionized water for 3 times, and then dried at a temperature of 85°C for 12 hours to obtain the coupling agent-coated hollow spherical calcium carbonate;

[0069] Preparation of polypropylene modified plastics:

[0070] Weigh each component according to the raw material composition. Specifically, the raw materials are weighed according to the following weight parts:

[0071] 105 parts of polypropylene resin, 21 parts of organic phosphorus flame retardant, 11 parts of hollow spherical calcium carbonate particles, 1 part of antioxidant, 0.25 parts of plasticizer;

[0072] After drying the above raw materials to remove moisture, pour them into a mixer and mix them evenly in the mixer;

[0073] The polypropylene modified plastic is obtained by extruding and molding with a twin-screw extruder and cooling.

[0074] When the extruder is used for processing, the temperature of the extruder section is regulated to be 178°C, the temperature of the melting section is 195°C, and the temperature of the homogenizing section is 205°C.

[0075] The coupling agent is selected from silane coupling agents;

[0076] The organophosphorus flame retardant is selected from ammonium polyphosphate;

[0077] The antioxidant is selected from antioxidant 626;

[0078] The plasticizer is selected from dibutyl phthalate.

[0079] Example 3

[0080] Preparation of hollow spherical calcium carbonate:

[0081] A calcium chloride solution with a concentration of 0.18 mol / L and an emulsifier solution with a concentration of 0.08 mol / L were mixed uniformly in a volume ratio of 1:1 to obtain a mixed solution; then, a sodium carbonate solution with a volume equal to that of the mixed solution was added at a stirring speed of 2500 r / min, and the concentration of the sodium carbonate solution was 1.03 times that of the calcium chloride solution; after the addition was completed, the stirring reaction was continued for 40 minutes;

[0082] Centrifuge to collect the precipitate, wash the precipitate with deionized water until the washing liquid is neutral, and then dry the washed precipitate at 90°C to constant weight to obtain a dry precipitate;

[0083] The dried precipitate was transferred into a muffle furnace, heated to 350°C at a rate of 4°C / min, kept at this temperature for calcination for 80 minutes, cooled to room temperature with the furnace, discharged, and sieved to obtain hollow spherical calcium carbonate;

[0084] The sphericity of the hollow spherical calcium carbonate is 9.0; and the D50 of the hollow spherical calcium carbonate is 60 μm;

[0085] Coating of coupling agent:

[0086] The hollow spherical calcium carbonate and the 70% ethanol solution by mass fraction were mixed in a mass ratio of 1:8, and ultrasonically dispersed for 10 minutes at an ultrasonic frequency of 100kHz, and then a coupling agent of 8% by mass of the hollow spherical calcium carbonate was added, and then heated and stirred for 2 hours at a temperature of 65°C and a stirring speed of 800r / min, and then filtered to collect the filter cake, and the filter cake was washed with deionized water for 3 times, and then dried at a temperature of 85°C for 12 hours to obtain the coupling agent-coated hollow spherical calcium carbonate;

[0087] Preparation of polypropylene modified plastics:

[0088] Weigh each component according to the raw material composition. Specifically, the raw materials are weighed according to the following weight parts:

[0089] 110 parts of polypropylene resin, 22 parts of organic phosphorus flame retardant, 12 parts of hollow spherical calcium carbonate particles, 1.2 parts of antioxidant, 0.3 parts of plasticizer;

[0090] After drying the above raw materials to remove moisture, pour them into a mixer and mix them evenly in the mixer;

[0091] The polypropylene modified plastic is obtained by extruding and molding with a twin-screw extruder and cooling.

[0092] When the extruder is used for processing, the temperature of the extruder section is regulated to be 178°C, the temperature of the melting section is 195°C, and the temperature of the homogenizing section is 205°C.

[0093] The coupling agent is selected from phthalate coupling agents;

[0094] The organophosphorus flame retardant is selected from triphenyl phosphate;

[0095] The antioxidant is selected from antioxidant 1010;

[0096] The plasticizer is selected from dioctyl phthalate.

[0097] Comparative Example 1

[0098] The difference between this comparative example and Example 1 is that no emulsifier solution is added, so the prepared calcium carbonate has no hollow structure; the other conditions remain unchanged.

[0099] Comparative Example 2

[0100] The difference between this comparative example and Example 1 is that, during the screening process, hollow spherical calcium carbonate with a D50 of 35 μm and a sphericity of 8.2 is obtained by screening, and the other conditions remain unchanged.

[0101] Comparative Example 3

[0102] The difference between this comparative example and Example 1 is that, during the screening process, hollow spherical calcium carbonate with a D50 of 70 μm and a sphericity of 8.4 is obtained by screening, and the other conditions remain unchanged.

[0103] Comparative Example 4

[0104] The difference between this comparative example and Example 1 is that no coupling agent is added to coat the hollow spherical calcium carbonate, and the other conditions remain unchanged.

[0105] The performance tests were performed on the products obtained in Examples 1-3 and Comparative Examples 1-4. The specific test methods and test results are as follows:

[0106] The products obtained in the above embodiments and comparative examples were taken respectively, and the products of each embodiment or comparative example were equally divided into two parts, one of which was directly tested for its limiting oxygen index 1 according to the method specified in GB / T2406.2-2009, and the specifications of the sample used were 100 mm×6.5 mm×3.2 mm;

[0107] Another portion was placed in a constant temperature and humidity simulation box, and treated with constant temperature and humidity for 28 days at a temperature of 45°C and a relative humidity of 75%. After that, it was taken out and the surface moisture was dried. Then, the limiting oxygen index 2 was tested according to the method specified in GB / T2406.2-2009. The specification of the sample used was 100mm×6.5mm×3.2mm.

[0108] The detailed test results are shown in Table 1:

[0109] Table 1: Product performance test results

[0110]

[0111]

[0112] It can be seen from the test results in Table 1 that the product obtained by the present invention has a good flame retardant effect, and after the simulated aging test, the flame retardant effect can still remain stable.

[0113] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A polypropylene modified plastic, characterized in that: The invention comprises the following raw materials in parts by weight: 100-110 parts of polypropylene resin, 20-22 parts of organic phosphorus flame retardant, 10-12 parts of hollow spherical calcium carbonate particles, 0.8-1.2 parts of antioxidant, 0.2-0.3 parts of plasticizer; Wherein, the sphericity of the hollow spherical calcium carbonate is 8.5-9.0; and the D50 of the hollow spherical calcium carbonate is 45-60 μm.

2. A polypropylene modified plastic according to claim 1, characterized in that: The surface of the hollow spherical calcium carbonate is coated with a coupling agent; The coupling agent is selected from any one of a silane coupling agent, a phthalate coupling agent or an aluminate coupling agent.

3. A polypropylene modified plastic according to claim 1, characterized in that: The organic phosphorus flame retardant is selected from any one of ammonium polyphosphate, aluminum hypophosphite, tributyl phosphate, triphenyl phosphate, tri(β-chloroethyl) phosphate, and dimethyl methyl phosphate.

4. A polypropylene modified plastic according to claim 1, characterized in that: The antioxidant is selected from any one of antioxidant 168, antioxidant 626, antioxidant 1010, antioxidant 1076 or antioxidant 3114.

5. The polypropylene modified plastic according to claim 1, characterized in that: The plasticizer is selected from any one of dioctyl phthalate, dibutyl phthalate, dioctyl adipate or n-octyl-n-decyl adipate.

6. A method for preparing a polypropylene modified plastic according to any one of claims 1 to 5, characterized in that: The specific preparation steps include: Preparation of hollow spherical calcium carbonate: The sodium carbonate solution and the calcium chloride solution are mixed, and an emulsifier is added, and the mixture is rapidly stirred for reaction, and then centrifuged to collect the precipitate, and the precipitate is washed and dried, and then calcined at a temperature of 340-350°C, cooled, discharged, and sieved to obtain hollow spherical calcium carbonate; Coating of coupling agent: Ultrasonic dispersion of hollow spherical calcium carbonate in an ethanol solution, adding a coupling agent, heating and stirring for reaction, filtering, washing and drying to obtain a coupling agent-coated hollow spherical calcium carbonate; Preparation of polypropylene modified plastics: Weigh each component according to the raw material composition, dry and remove moisture, and mix them evenly in a mixer; The polypropylene modified plastic is obtained by extruding and cooling.

7. The method for preparing a polypropylene modified plastic according to claim 6, characterized in that: The emulsifier is selected from any one of sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, hexadecyltrimethylammonium bromide and octadecyldimethylbenzyl ammonium chloride.

8. The method for preparing a polypropylene modified plastic according to claim 6, characterized in that: The preparation of the hollow spherical calcium carbonate comprises: A calcium chloride solution with a concentration of 0.15-0.18 mol / L and an emulsifier solution with a concentration of 0.06-0.08 mol / L are mixed uniformly in a volume ratio of 1:1 to obtain a mixed solution; then, a sodium carbonate solution with a volume equal to that of the mixed solution is added under stirring, and the concentration of the sodium carbonate solution is 1.01-1.03 times that of the calcium chloride solution; after the addition is completed, the stirring reaction is continued for 30-40 minutes; Centrifuge to collect the precipitate, wash the precipitate with deionized water until the washing liquid is neutral, and then dry the washed precipitate at 90°C to constant weight to obtain a dry precipitate; The dried precipitate is transferred into a muffle furnace, heated to 340-350°C at a rate of 2-4°C / min, kept warm and calcined for 60-80 minutes, cooled to room temperature with the furnace, discharged, and sieved to obtain hollow spherical calcium carbonate.

9. The method for preparing a polypropylene modified plastic according to claim 8, characterized in that: The stirring state is: the stirring speed is 2200-2500r / min.

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