Polyolefin-based plastic particles and production process thereof

Abstract

The invention relates to the technical field of plastics, and discloses a polyolefin-based plastic particle and a production process thereof, the plastic particle is prepared by taking high density polyethylene as a base material and cooperating with linear low density polyethylene, a compatilizer, a functional agent and other auxiliary materials through mixing and extrusion granulation processes, wherein the functional agent is prepared by modifying a polymeric macromolecular nitrogen-phosphorus flame retardant on the surface of hydroxyapatite, and in the subsequent high-temperature melt extrusion process, the molecular chain of the polymeric macromolecular nitrogen-phosphorus flame retardant can extend to each region of a polyethylene matrix, so that the hydroxyapatite exists in the matrix in the form of a physical crosslinking point, and the flame retardance of the polyethylene matrix is improved. On one hand, the advantage of self inorganic enhancement can be efficiently played, the mechanical property of the material is improved, and on the other hand, the uniformly dispersed hydroxyapatite can also cooperate with the polymeric macromolecular nitrogen-phosphorus flame retardant, so that the flame retardant property of the material is effectively improved.

Description

Technical Field

[0001] The invention relates to the technical field of plastics, and in particular to polyolefin-based plastic particles and a production process thereof. Background Art

[0002] Polyethylene is a polymer compound formed by the polymerization of ethylene monomers and is a thermoplastic. Polyethylene can be divided into three types: low-density polyethylene, high-density polyethylene and linear low-density polyethylene. Different types of polyethylene have different physical properties and are suitable for different processing techniques and applications. For example, low-density polyethylene is softer and suitable for making films and containers, while high-density polyethylene has a higher density and is often used to make pipes, bottles, etc. Due to the excellent properties of polyethylene itself, such as light weight, high weather resistance, strong corrosion resistance and high transparency, polyethylene plastic particles are widely used in packaging, construction, transportation, agriculture and other fields. However, the poor flame retardancy of polyethylene plastic particles not only limits its application in specific fields, but also may pose a potential threat to human life and property safety.

[0003] At present, it is common to improve the flame retardant properties of polyethylene plastic particles by adding flame retardants. Generally, inorganic flame retardants such as magnesium hydroxide and aluminum hydroxide can be added. However, the modification effect of such inorganic flame retardants themselves is poor, and generally a large amount of addition is required to produce a considerable modification effect. However, there are serious interface problems between inorganic substances and polyethylene. If the addition exceeds the threshold, agglomeration will occur, which has a negative impact on the mechanical strength of polyethylene. In addition, organic small molecule flame retardants such as DOPO can also be added, but similarly, such flame retardants also have the defect of being volatile and cannot exist in polyethylene plastic particles for a long time, which leads to the inability to ensure the long-term flame retardant properties of polyethylene plastics. Based on this, the present invention provides a polyethylene plastic particle that can solve the problems existing in the prior art. Summary of the invention

[0004] 1. Technical issues to be resolved

[0005] In view of the deficiencies of the prior art, the present invention provides a polyolefin-based plastic particle and a production process thereof.

[0006] (II) Technical solution

[0007] A process for producing polyolefin-based plastic particles, wherein the plastic particles are made from the following raw materials measured in parts by weight:

[0008]

[0009] The production process comprises the following steps:

[0010] Step 1: Weigh and prepare each raw material according to weight;

[0011] Step 2: Add all raw materials into a mixer, start stirring, set the temperature to 80-100°C, the stirring rate to 1000-2000r / min, stir evenly to form a mixture;

[0012] Step 3: Move the mixed material into a twin-screw extruder for melt extrusion granulation to obtain plastic particles.

[0013] As a further embodiment of the present invention, the compatibilizer is maleic anhydride grafted polyethylene or maleic anhydride grafted polypropylene.

[0014] As a further embodiment of the present invention, the preparation method of the functional agent comprises the following steps:

[0015] Step S1, ultrasonically dispersing hydroxyapatite in a mixed solution of ethanol and water in a volume ratio of 1:1, then adding a silane coupling agent to the formed dispersion, raising the temperature to 60-70° C., keeping the temperature and stirring for 6-8 hours, separating a solid product, and obtaining modified hydroxyapatite;

[0016] Step S2, the modified hydroxyapatite and N, N-dimethylformamide are mixed and evenly dispersed, and then an amine substance is added, and then the temperature is increased to 60-70°C, and the mixture is stirred for 2-4 hours, and then the reactive nitrogen-phosphorus-containing flame retardant is added. After the addition is completed, the temperature is further increased to 75-85°C, and the mixture is stirred for 6-12 hours, and then the heating is stopped, the temperature is lowered, and the solid material is centrifuged to obtain the functional agent.

[0017] As a further embodiment of the present invention, in step S1, the silane coupling agent is γ-glycidyloxypropyltrimethoxysilane or γ-glycidyloxypropyltriethoxysilane.

[0018] As a further embodiment of the present invention, in step S2, the amine substance is diethylenetriamine or triethylenetetramine.

[0019] As a further solution of the present invention, in step S2, the preparation method of the reactive nitrogen-phosphorus-containing flame retardant is as follows:

[0020] Add flame retardant FRC-2 and tetrahydrofuran solvent to a reactor filled with nitrogen, start stirring, and place in an ice bath environment after a uniform reaction liquid is formed. Then, add 2,6-dichloropyrimidine-4-carbonyl chloride and an acid binding agent to the reaction liquid. After the addition is complete, remove the ice bath, stir fully for 3-6 hours at room temperature, remove nitrogen, evaporate to remove the solvent, collect the product, and the reactive nitrogen-phosphorus-containing flame retardant can be obtained.

[0021] As a further embodiment of the present invention, the molar ratio of the flame retardant FRC-2 to 2,6-dichloropyrimidine-4-carbonyl chloride is 1:1.

[0022] As a further embodiment of the present invention, the acid binding agent is triethylamine or pyridine.

[0023] As a further embodiment of the present invention, in step S2, the mass ratio of the modified hydroxyapatite, the amine substance and the reactive nitrogen-phosphorus-containing flame retardant is 1:2-3:0.5-1.

[0024] In the above technical scheme, firstly, the flame retardant FRC-2 and 2,6-dichloropyrimidine-4-carbonyl chloride are used as reactants, and a condensation reaction is carried out under the action of an acid binding agent to obtain a reactive nitrogen-phosphorus-containing flame retardant having two equivalents of halogen substituents in its structure.

[0025] The epoxy-modified hydroxyapatite is prepared by using a silane coupling agent to modify the surface of hydroxyapatite, and then an excess of amine substances is used as a bridging agent to first undergo a ring-opening addition reaction with the epoxy group of the modified hydroxyapatite, and the excess amino groups in the structure further undergo a continuous substitution reaction with the halogen substituents in the structure of the reactive nitrogen-phosphorus flame retardant, thereby modifying the surface of the hydroxyapatite with a polymerized macromolecular nitrogen-phosphorus flame retardant to obtain a functional agent.

[0026] A polyolefin-based plastic particle is prepared by adopting the above production process.

[0027] (III) Beneficial technical effects

[0028] The present invention prepares a functional agent by modifying the surface of hydroxyapatite with a polymerized macromolecular nitrogen-phosphorus flame retardant, and uses the functional agent as an additive to perform blending modification on a high-density polyethylene matrix, wherein the presence of the polymerized macromolecular nitrogen-phosphorus flame retardant is equivalent to forming a layer of organic transition structure between the hydroxyapatite and the polyethylene matrix, and the organic transition structure can greatly improve the interface performance between the inorganic hydroxyapatite and the polyethylene matrix, and in the subsequent high-temperature melt extrusion process, the molecular chain of the polymerized macromolecular nitrogen-phosphorus flame retardant can extend to various regions of the polyethylene matrix, so that the hydroxyapatite exists in the matrix in the form of physical crosslinking points, which can effectively exert its own inorganic reinforcement advantages and improve the mechanical properties of the material, and the uniformly dispersed hydroxyapatite can also cooperate with the polymerized macromolecular nitrogen-phosphorus flame retardant to effectively improve the flame retardant performance of the material, thereby further expanding its application range. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0030] Figure 1 This is the infrared analysis test diagram of reactive nitrogen-phosphorus flame retardant. DETAILED DESCRIPTION

[0031] In order to facilitate the understanding of the present invention, the present invention will be described more fully below. Preferred embodiments of the present invention are given below. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0032] Preparation Example 1

[0033] Preparation of functional agent:

[0034] Step S1, ultrasonically dispersing 3 g of hydroxyapatite in a mixed solution of ethanol and water in a volume ratio of 1:1, then adding 4.5 g of γ-glycidyloxypropyltriethoxysilane to the formed dispersion, after the addition, raising the temperature to 65° C., keeping the mixture warm and stirring for 8 hours, separating the solid product, and obtaining the modified hydroxyapatite;

[0035] Step S2, 2.5g of modified hydroxyapatite and N,N-dimethylformamide are mixed and dispersed evenly, 6g of diethylenetriamine is added, and then the temperature is raised to 65°C. After stirring for 3 hours, 1.5g of reactive nitrogen-phosphorus-containing flame retardant is added. After the addition is completed, the temperature is further raised to 80°C. After stirring for 9 hours, heating is stopped, the temperature is lowered and the material is discharged, and the solid material is centrifuged to obtain the functional agent.

[0036] The preparation method of the reactive nitrogen-phosphorus flame retardant is as follows:

[0037] Add 0.3 g of flame retardant FRC-2 and tetrahydrofuran solvent to a reactor filled with nitrogen, start stirring, and after a uniform reaction liquid is formed, place it in an ice bath environment. Then, add 0.3 g of 2,6-dichloropyrimidine-4-carbonyl chloride and 0.05 g of triethylamine to the reaction liquid. After the addition is complete, remove the ice bath, stir thoroughly for 4 hours at room temperature, remove the nitrogen, evaporate to remove the solvent, collect the product, and the reactive nitrogen-phosphorus-containing flame retardant can be obtained.

[0038] Figure 1 This is the infrared analysis test chart of the reactive nitrogen-phosphorus flame retardant, where 3394cm -1The characteristic absorption peak at 2800-3000cm is the NH characteristic absorption peak in the amide group. -1 The characteristic absorption peak at 1739cm is the characteristic absorption peak of CH of methyl and ethyl. -1 The characteristic absorption peak at 1689cm is the C=O characteristic absorption peak in the ester group. -1 The characteristic absorption peak at 1288 cm is the C=O characteristic absorption peak in the amide bond. -1 The characteristic absorption peak at is the P=O characteristic absorption peak.

[0039] Example 1

[0040] A polyolefin-based plastic particle is made of the following raw materials measured in parts by weight:

[0041]

[0042] The production process of plastic particles includes the following steps:

[0043] Step 1: Weigh and prepare each raw material according to weight;

[0044] Step 2: Add all raw materials into a mixer, start stirring, set the temperature to 80°C, the stirring rate to 1000r / min, stir evenly to form a mixture;

[0045] Step 3: Move the mixture into a twin-screw extruder, control the temperature of each zone of the extruder to be: 220°C in zone 1, 230°C in zone 2, 240°C in zone 3, 240°C in zone 4, and 230°C in zone 5, and the screw speed is 50rpm. Perform melt extrusion granulation to obtain plastic particles.

[0046] The compatibilizer is maleic anhydride grafted polyethylene; the functional agent is the functional agent prepared in the preparation example; the antioxidant is antioxidant 1010; the ultraviolet absorber is ultraviolet absorber UV-234; the lubricant is polyethylene wax, and the following are the same.

[0047] Example 2

[0048] A polyolefin-based plastic particle is made of the following raw materials measured in parts by weight:

[0049]

[0050]

[0051] The production process of plastic particles includes the following steps:

[0052] Step 1: Weigh and prepare each raw material according to weight;

[0053] Step 2: Add all raw materials into a mixer, start stirring, set the temperature to 100°C, the stirring rate to 1500r / min, stir evenly to form a mixture;

[0054] Step 3: Move the mixture into a twin-screw extruder, control the temperature of each zone of the extruder to be: 220°C in zone 1, 230°C in zone 2, 240°C in zone 3, 240°C in zone 4, and 230°C in zone 5, and the screw speed is 50rpm. Perform melt extrusion granulation to obtain plastic particles.

[0055] Example 3

[0056] A polyolefin-based plastic particle is made of the following raw materials measured in parts by weight:

[0057]

[0058] The production process of plastic particles includes the following steps:

[0059] Step 1: Weigh and prepare each raw material according to weight;

[0060] Step 2: Add all raw materials into a mixer, start stirring, set the temperature to 100°C, the stirring rate to 2000r / min, stir evenly to form a mixture;

[0061] Step 3: Move the mixture into a twin-screw extruder, control the temperature of each zone of the extruder to be: 220°C in zone 1, 230°C in zone 2, 240°C in zone 3, 240°C in zone 4, and 230°C in zone 5, and the screw speed is 50rpm. Perform melt extrusion granulation to obtain plastic particles.

[0062] Comparative Example 1

[0063] A polyolefin-based plastic particle is made of the following raw materials measured in parts by weight:

[0064]

[0065] The production process of plastic particles includes the following steps:

[0066] Step 1: Weigh and prepare each raw material according to weight;

[0067] Step 2: Add all raw materials into a mixer, start stirring, set the temperature to 100°C, the stirring rate to 1500r / min, stir evenly to form a mixture;

[0068] Step 3: Move the mixture into a twin-screw extruder, control the temperature of each zone of the extruder to be: 220°C in zone 1, 230°C in zone 2, 240°C in zone 3, 240°C in zone 4, and 230°C in zone 5, and the screw speed is 50rpm. Perform melt extrusion granulation to obtain plastic particles.

[0069] Comparative Example 2

[0070] A polyolefin-based plastic particle is made of the following raw materials measured in parts by weight:

[0071]

[0072] The production process of plastic particles includes the following steps:

[0073] Step 1: Weigh and prepare each raw material according to weight;

[0074] Step 2: Add all raw materials into a mixer, start stirring, set the temperature to 100°C, the stirring rate to 1500r / min, stir evenly to form a mixture;

[0075] Step 3: Move the mixture into a twin-screw extruder, control the temperature of each zone of the extruder to be: 220°C in zone 1, 230°C in zone 2, 240°C in zone 3, 240°C in zone 4, and 230°C in zone 5, and the screw speed is 50rpm. Perform melt extrusion granulation to obtain plastic particles.

[0076] The preparation method of the reactive nitrogen-phosphorus-containing flame retardant is shown in Preparation Example 1.

[0077] Comparative Example 3

[0078] A polyolefin-based plastic particle is made of the following raw materials measured in parts by weight:

[0079]

[0080]

[0081] The production process of plastic particles includes the following steps:

[0082] Step 1: Weigh and prepare each raw material according to weight;

[0083] Step 2: Add all raw materials into a mixer, start stirring, set the temperature to 100°C, the stirring rate to 1500r / min, stir evenly to form a mixture;

[0084] Step 3: Move the mixture into a twin-screw extruder, control the temperature of each zone of the extruder to be: 220°C in zone 1, 230°C in zone 2, 240°C in zone 3, 240°C in zone 4, and 230°C in zone 5, and the screw speed is 50rpm. Perform melt extrusion granulation to obtain plastic particles.

[0085] Test Case

[0086] The plastic particles in the embodiments and comparative examples were injection molded into test specimens that met the specifications and various performance tests were performed. The results are recorded in Table 1:

[0087] Table 1 - Test results

[0088] Tensile strength / MPa Limiting oxygen index / % Test Standards GB / T 1040-1992 GB / T 2406.1-2008 Example 1 87.4 32.2 Example 2 88.0 32.3 Example 3 87.8 32.2 Comparative Example 1 74.7 20.5 Comparative Example 2 67.1 30.9 Comparative Example 3 66.9 18.7

[0089] The limiting oxygen index test time is after the specimens are placed at room temperature for 2 months.

[0090] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" 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 representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0091] Based on the ideal embodiment of the present invention, through the above description, relevant personnel can make various changes and modifications without departing from the technical concept of the present invention. The technical scope of the present invention is not limited to the content in the specification, and the technical scope must be determined according to the scope of the claims.

Claims

1. A production process for polyolefin-based plastic particles, characterized in that: The plastic particles are made of the following raw materials measured in parts by weight: The production process comprises the following steps: Step 1: Weigh and prepare each raw material according to weight; Step 2: Add all raw materials into a mixer, start stirring, set the temperature to 80-100°C, the stirring rate to 1000-2000r / min, stir evenly to form a mixture; Step 3: Move the mixed material into a twin-screw extruder for melt extrusion granulation to obtain plastic particles.

2. A process for producing polyolefin-based plastic particles according to claim 1, characterized in that: The compatibilizer is maleic anhydride grafted polyethylene or maleic anhydride grafted polypropylene.

3. A process for producing polyolefin-based plastic particles according to claim 1, characterized in that: The preparation method of the functional agent comprises the following steps: Step S1, ultrasonically dispersing hydroxyapatite in a mixed solution of ethanol and water in a volume ratio of 1:1, then adding a silane coupling agent to the formed dispersion, raising the temperature to 60-70° C., keeping the temperature and stirring for 6-8 hours, separating a solid product, and obtaining modified hydroxyapatite; Step S2, the modified hydroxyapatite and N, N-dimethylformamide are mixed and evenly dispersed, and then an amine substance is added, and then the temperature is increased to 60-70°C, and the mixture is stirred for 2-4 hours, and then the reactive nitrogen-phosphorus-containing flame retardant is added. After the addition is completed, the temperature is further increased to 75-85°C, and the mixture is stirred for 6-12 hours, and then the heating is stopped, the temperature is lowered, and the solid material is centrifuged to obtain the functional agent.

4. A process for producing polyolefin-based plastic particles according to claim 3, characterized in that: In step S1, the silane coupling agent is γ-glycidyloxypropyltrimethoxysilane or γ-glycidyloxypropyltriethoxysilane.

5. A process for producing polyolefin-based plastic particles according to claim 3, characterized in that: In step S2, the amine substance is diethylenetriamine or triethylenetetramine.

6. A process for producing polyolefin-based plastic particles according to claim 3, characterized in that: In step S2, the preparation method of the reactive nitrogen-phosphorus-containing flame retardant is as follows: Add flame retardant FRC-2 and tetrahydrofuran solvent to a reactor filled with nitrogen, start stirring, and place in an ice bath environment after a uniform reaction liquid is formed. Then, add 2,6-dichloropyrimidine-4-carbonyl chloride and an acid binding agent to the reaction liquid. After the addition is complete, remove the ice bath, stir fully for 3-6 hours at room temperature, remove nitrogen, evaporate to remove the solvent, collect the product, and the reactive nitrogen-phosphorus-containing flame retardant can be obtained.

7. A process for producing polyolefin-based plastic particles according to claim 6, characterized in that: The molar ratio of the flame retardant FRC-2 to 2,6-dichloropyrimidine-4-carbonyl chloride is 1:

1.

8. A process for producing polyolefin-based plastic particles according to claim 6, characterized in that: The acid binding agent is triethylamine or pyridine.

9. A process for producing polyolefin-based plastic particles according to claim 3, characterized in that: In step S2, the mass ratio of the modified hydroxyapatite, the amine substance and the reactive nitrogen-phosphorus-containing flame retardant is 1:2-3:0.5-1.

10. A polyolefin-based plastic particle, characterized in that: The method is prepared by the production process according to any one of claims 1 to 9.

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